201
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Bevilacqua A, Ho PC, Franco F. Metabolic reprogramming in inflammaging and aging in T cells. LIFE METABOLISM 2023; 2:load028. [PMID: 39872627 PMCID: PMC11749375 DOI: 10.1093/lifemeta/load028] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 01/30/2025]
Abstract
Aging represents an emerging challenge for public health due to the declined immune responses against pathogens, weakened vaccination efficacy, and disturbed tissue homeostasis. Metabolic alterations in cellular and systemic levels are also known to be cardinal features of aging. Moreover, cellular metabolism has emerged to provide regulations to guide immune cell behavior via modulations on signaling cascades and epigenetic landscape, and the aberrant aging process in immune cells can lead to inflammaging, a chronic and low-grade inflammation that facilitates aging by perturbing homeostasis in tissues and organs. Here, we review how the metabolic program in T cells is influenced by the aging process and how aged T cells modulate inflammaging. In addition, we discuss the potential approaches to reverse or ameliorate aging by rewiring the metabolic programming of immune cells.
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Affiliation(s)
- Alessio Bevilacqua
- Department of Fundamental Oncology, University of Lausanne, 1007 Lausanne, Switzerland
- Ludwig Institute for Cancer Research, University of Lausanne, 1066 Epalinges, Switzerland
| | - Ping-Chih Ho
- Department of Fundamental Oncology, University of Lausanne, 1007 Lausanne, Switzerland
- Ludwig Institute for Cancer Research, University of Lausanne, 1066 Epalinges, Switzerland
| | - Fabien Franco
- Department of Fundamental Oncology, University of Lausanne, 1007 Lausanne, Switzerland
- Ludwig Institute for Cancer Research, University of Lausanne, 1066 Epalinges, Switzerland
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202
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McGinnis MM, Sutter BM, Jahangiri S, Tu BP. Exonuclease Xrn1 regulates TORC1 signaling in response to SAM availability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.28.559955. [PMID: 37808861 PMCID: PMC10557749 DOI: 10.1101/2023.09.28.559955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Autophagy is a conserved process of cellular self-digestion that promotes survival during nutrient stress. In yeast, methionine starvation is sufficient to induce autophagy. One pathway of autophagy induction is governed by the SEACIT complex, which regulates TORC1 activity in response to amino acids through the Rag GTPases Gtr1 and Gtr2. However, the precise mechanism by which SEACIT senses amino acids and regulates TORC1 signaling remains incompletely understood. Here, we identify the conserved 5'-3' RNA exonuclease Xrn1 as a surprising and novel regulator of TORC1 activity in response to methionine starvation. This role of Xrn1 is dependent on its catalytic activity, but not on degradation of any specific class of mRNAs. Instead, Xrn1 modulates the nucleotide-binding state of the Gtr1/2 complex, which is critical for its interaction with and activation of TORC1. This work identifies a critical role for Xrn1 in nutrient sensing and growth control that extends beyond its canonical housekeeping function in RNA degradation and indicates an avenue for RNA metabolism to function in amino acid signaling into TORC1.
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Affiliation(s)
- Madeline M McGinnis
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Benjamin M Sutter
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Samira Jahangiri
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Benjamin P Tu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
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203
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Chen Y, Su H, Zhao J, Na Z, Jiang K, Bacchiocchi A, Loh KH, Halaban R, Wang Z, Cao X, Slavoff SA. Unannotated microprotein EMBOW regulates the interactome and chromatin and mitotic functions of WDR5. Cell Rep 2023; 42:113145. [PMID: 37725512 PMCID: PMC10629662 DOI: 10.1016/j.celrep.2023.113145] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 07/20/2023] [Accepted: 08/31/2023] [Indexed: 09/21/2023] Open
Abstract
The conserved WD40-repeat protein WDR5 interacts with multiple proteins both inside and outside the nucleus. However, it is currently unclear whether and how the distribution of WDR5 between complexes is regulated. Here, we show that an unannotated microprotein EMBOW (endogenous microprotein binder of WDR5) dually encoded in the human SCRIB gene interacts with WDR5 and regulates its binding to multiple interaction partners, including KMT2A and KIF2A. EMBOW is cell cycle regulated, with two expression maxima at late G1 phase and G2/M phase. Loss of EMBOW decreases WDR5 interaction with KIF2A, aberrantly shortens mitotic spindle length, prolongs G2/M phase, and delays cell proliferation. In contrast, loss of EMBOW increases WDR5 interaction with KMT2A, leading to WDR5 binding to off-target genes, erroneously increasing H3K4me3 levels, and activating transcription of these genes. Together, these results implicate EMBOW as a regulator of WDR5 that regulates its interactions and prevents its off-target binding in multiple contexts.
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Affiliation(s)
- Yanran Chen
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Institute for Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA; Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China; Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Sciences, East China Normal University, Shanghai 200062, China
| | - Haomiao Su
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Institute for Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA
| | - Jianing Zhao
- Frontier Innovation Center, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200433, China; Shanghai Fifth People's Hospital, Fudan University, Shanghai 200433, China
| | - Zhenkun Na
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Institute for Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA
| | - Kevin Jiang
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Institute for Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA
| | - Antonella Bacchiocchi
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Ken H Loh
- Institute for Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA; Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Ruth Halaban
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Zhentian Wang
- Frontier Innovation Center, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200433, China; Shanghai Fifth People's Hospital, Fudan University, Shanghai 200433, China
| | - Xiongwen Cao
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Institute for Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA; Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China; Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Sciences, East China Normal University, Shanghai 200062, China.
| | - Sarah A Slavoff
- Department of Chemistry, Yale University, New Haven, CT 06520, USA; Institute for Biomolecular Design and Discovery, Yale University, West Haven, CT 06516, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06529, USA.
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204
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Priya A, Antoine-Bally S, Macé AS, Monteiro P, Sabatet V, Remy D, Dingli F, Loew D, Demetriades C, Gautreau AM, Chavrier P. Codependencies of mTORC1 signaling and endolysosomal actin structures. SCIENCE ADVANCES 2023; 9:eadd9084. [PMID: 37703363 PMCID: PMC10881074 DOI: 10.1126/sciadv.add9084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/11/2023] [Indexed: 09/15/2023]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is part of the amino acid sensing machinery that becomes activated on the endolysosomal surface in response to nutrient cues. Branched actin generated by WASH and Arp2/3 complexes defines endolysosomal microdomains. Here, we find mTORC1 components in close proximity to endolysosomal actin microdomains. We investigated for interactors of the mTORC1 lysosomal tether, RAGC, by proteomics and identified multiple actin filament capping proteins and their modulators. Perturbation of RAGC function affected the size of endolysosomal actin, consistent with a regulation of actin filament capping by RAGC. Reciprocally, the pharmacological inhibition of actin polymerization or alteration of endolysosomal actin obtained upon silencing of WASH or Arp2/3 complexes impaired mTORC1 activity. Mechanistically, we show that actin is required for proper association of RAGC and mTOR with endolysosomes. This study reveals an unprecedented interplay between actin and mTORC1 signaling on the endolysosomal system.
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Affiliation(s)
- Amulya Priya
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Sandra Antoine-Bally
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Anne-Sophie Macé
- Institut Curie, PSL Research University, Cell and Tissue Imaging Facility (PICT-IBiSA), 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Pedro Monteiro
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Valentin Sabatet
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - David Remy
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Florent Dingli
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Damarys Loew
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Alexis M. Gautreau
- Laboratoire de Biologie Structurale de la Cellule, CNRS, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Philippe Chavrier
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
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205
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Voss PA, Gornik SG, Jacobovitz MR, Rupp S, Dörr M, Maegele I, Guse A. Host nutrient sensing is mediated by mTOR signaling in cnidarian-dinoflagellate symbiosis. Curr Biol 2023; 33:3634-3647.e5. [PMID: 37572664 DOI: 10.1016/j.cub.2023.07.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/31/2023] [Accepted: 07/20/2023] [Indexed: 08/14/2023]
Abstract
To survive in the nutrient-poor waters of the tropics, reef-building corals rely on intracellular, photosynthetic dinoflagellate symbionts. Photosynthates produced by the symbiont are translocated to the host, and this enables corals to form the structural foundation of the most biodiverse of all marine ecosystems. Although the regulation of nutrient exchange between partners is critical for ecosystem stability and health, the mechanisms governing how nutrients are sensed, transferred, and integrated into host cell processes are largely unknown. Ubiquitous among eukaryotes, the mechanistic target of the rapamycin (mTOR) signaling pathway integrates intracellular and extracellular stimuli to influence cell growth and cell-cycle progression and to balance metabolic processes. A functional role of mTOR in the integration of host and symbiont was demonstrated in various nutritional symbioses, and a similar role of mTOR was proposed for coral-algal symbioses. Using the endosymbiosis model Aiptasia, we examined the role of mTOR signaling in both larvae and adult polyps across various stages of symbiosis. We found that symbiosis enhances cell proliferation, and using an Aiptasia-specific antibody, we localized mTOR to symbiosome membranes. We found that mTOR signaling is activated by symbiosis, while inhibition of mTOR signaling disrupts intracellular niche establishment and symbiosis altogether. Additionally, we observed that dysbiosis was a conserved response to mTOR inhibition in the larvae of a reef-building coral species. Our data confim that mTOR signaling plays a pivotal role in integrating symbiont-derived nutrients into host metabolism and symbiosis stability, ultimately allowing symbiotic cnidarians to thrive in challenging environments.
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Affiliation(s)
- Philipp A Voss
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120 Germany
| | - Sebastian G Gornik
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120 Germany
| | - Marie R Jacobovitz
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120 Germany
| | - Sebastian Rupp
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120 Germany
| | - Melanie Dörr
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120 Germany
| | - Ira Maegele
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120 Germany
| | - Annika Guse
- Centre for Organismal Studies, Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120 Germany.
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206
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Li N, Rao L, Zhao X, Shen J, Su D, Ma G, Sun S, Ma Q, Zhang L, Dong C, Tam KY, Prehn JHM, Wang H, Ying Z. Chlorpromazine affects autophagy in association with altered Rag GTPase-mTORC1-TFEB signaling. Front Cell Dev Biol 2023; 11:1266198. [PMID: 37745295 PMCID: PMC10514517 DOI: 10.3389/fcell.2023.1266198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 08/21/2023] [Indexed: 09/26/2023] Open
Abstract
Autophagy is a critical protein and organelle quality control system, which regulates cellular homeostasis and survival. Growing pieces of evidence suggest that autophagic dysfunction is strongly associated with many human diseases, including neurological diseases and cancer. Among various autophagic regulators, microphthalmia (MiT)/TFE transcription factors, including transcription factor EB (TFEB), have been shown to act as the master regulators of autophagosome and lysosome biogenesis in both physiological and pathological conditions. According to the previous studies, chlorpromazine (CPZ), an FDA-approved antipsychotic drug, affects autophagy in diverse cell lines, but the underlying mechanism remains elusive. In our present study, we find that CPZ treatment induces TFEB nuclear translocation through Rag GTPases, the upstream regulators of mechanistic target of rapamycin complex 1 (mTORC1) signaling. Meanwhile, CPZ treatment also blocks autophagosome-lysosome fusion. Notably, we find a significant accumulation of immature autophagosome vesicles in CPZ-treated cells, which may impede cellular homeostasis due to the dysfunction of the autophagy-lysosome pathway. Interestingly and importantly, our data suggest that the expression of the active form of Rag GTPase heterodimers helps in reducing the accumulation of autophagosomes in CPZ-treated cells, further suggesting a major contribution of the Rag GTPase-mTORC1-TFEB signaling axis in CPZ-induced autophagic impairment.
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Affiliation(s)
- Ningning Li
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Lingling Rao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Xueqing Zhao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Junwen Shen
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Dan Su
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Guoqiang Ma
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Shan Sun
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
- Faculty of Health Sciences, University of Macau, Taipa, China
| | - Qilian Ma
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
- Department of Physiology and Medical Physics and Future-Neuro Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Li Zhang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| | - Chunsheng Dong
- Institutes of Biology and Medical Science, Soochow University, Suzhou, China
| | - Kin Yip Tam
- Faculty of Health Sciences, University of Macau, Taipa, China
| | - Jochen H. M. Prehn
- Department of Physiology and Medical Physics and Future-Neuro Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Hongfeng Wang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Zheng Ying
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China
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207
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Tettoni SD, Egri SB, Doxsey DD, Veinotte K, Ouch C, Chang JY, Song K, Xu C, Shen K. Structure of the Schizosaccharomyces pombe Gtr-Lam complex reveals evolutionary divergence of mTORC1-dependent amino acid sensing. Structure 2023; 31:1065-1076.e5. [PMID: 37453417 PMCID: PMC10529327 DOI: 10.1016/j.str.2023.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/14/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
mTORC1 is a protein kinase complex that controls cellular growth in response to nutrient availability. Amino acid signals are transmitted toward mTORC1 via the Rag/Gtr GTPases and their upstream regulators. An important regulator is LAMTOR, which localizes Rag/Gtr on the lysosomal/vacuole membrane. In human cells, LAMTOR consists of five subunits, but in yeast, only three or four. Currently, it is not known how variation of the subunit stoichiometry may affect its structural organization and biochemical properties. Here, we report a 3.1 Å-resolution structural model of the Gtr-Lam complex in Schizosaccharomyces pombe. We found that SpGtr shares conserved architecture as HsRag, but the intersubunit communication that coordinates nucleotide loading on the two subunits differs. In contrast, SpLam contains distinctive structural features, but its GTP-specific GEF activity toward SpGtr is evolutionarily conserved. Our results revealed unique evolutionary paths of the protein components of the mTORC1 pathway.
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Affiliation(s)
- Steven D Tettoni
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Shawn B Egri
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Dylan D Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Kristen Veinotte
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Christna Ouch
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Jeng-Yih Chang
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Kangkang Song
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Chen Xu
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA; Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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208
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Li TY, Wang Q, Gao AW, Li X, Sun Y, Mottis A, Shong M, Auwerx J. Lysosomes mediate the mitochondrial UPR via mTORC1-dependent ATF4 phosphorylation. Cell Discov 2023; 9:92. [PMID: 37679337 PMCID: PMC10484937 DOI: 10.1038/s41421-023-00589-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 07/21/2023] [Indexed: 09/09/2023] Open
Abstract
Lysosomes are central platforms for not only the degradation of macromolecules but also the integration of multiple signaling pathways. However, whether and how lysosomes mediate the mitochondrial stress response (MSR) remain largely unknown. Here, we demonstrate that lysosomal acidification via the vacuolar H+-ATPase (v-ATPase) is essential for the transcriptional activation of the mitochondrial unfolded protein response (UPRmt). Mitochondrial stress stimulates v-ATPase-mediated lysosomal activation of the mechanistic target of rapamycin complex 1 (mTORC1), which then directly phosphorylates the MSR transcription factor, activating transcription factor 4 (ATF4). Disruption of mTORC1-dependent ATF4 phosphorylation blocks the UPRmt, but not other similar stress responses, such as the UPRER. Finally, ATF4 phosphorylation downstream of the v-ATPase/mTORC1 signaling is indispensable for sustaining mitochondrial redox homeostasis and protecting cells from ROS-associated cell death upon mitochondrial stress. Thus, v-ATPase/mTORC1-mediated ATF4 phosphorylation via lysosomes links mitochondrial stress to UPRmt activation and mitochondrial function resilience.
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Affiliation(s)
- Terytty Yang Li
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodeling and Health, Laboratory of Longevity and Metabolic Adaptations, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China.
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| | - Qi Wang
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Arwen W Gao
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology, Endocrinology, and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Xiaoxu Li
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Yu Sun
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Metabolic Remodeling and Health, Laboratory of Longevity and Metabolic Adaptations, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China
| | - Adrienne Mottis
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Minho Shong
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, Korea
| | - Johan Auwerx
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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209
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Hela F, Aguayo-Mazzucato C. Interaction between Autophagy and Senescence in Pancreatic Beta Cells. BIOLOGY 2023; 12:1205. [PMID: 37759604 PMCID: PMC10525299 DOI: 10.3390/biology12091205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 09/01/2023] [Accepted: 09/02/2023] [Indexed: 09/29/2023]
Abstract
Aging leads to an increase in cellular stress due to the fragility of the organism and the inability to cope with it. In this setting, there is a higher chance of developing different cardiometabolic diseases like diabetes. Cellular senescence and autophagy, both hallmarks of aging and stress-coping mechanisms, have gained increased attention for their role in the pathophysiology of diabetes. Studies show that impairing senescence dampens and even prevents diabetes while the role of autophagy is more contradictory, implying a context- and disease-stage-dependent effect. Reports show conflicting data about the effect of autophagy on senescence while the knowledge about this interaction in beta cells remains scarce. Elucidating this interaction between autophagy and senescence in pancreatic beta cells will lead to an identification of their respective roles and the extent of the effect each mechanism has on beta cells and open new horizons for developing novel therapeutic agents. To help illuminate this relationship we will review the latest findings of cellular senescence and autophagy with a special emphasis on pancreatic beta cells and diabetes.
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Affiliation(s)
| | - Cristina Aguayo-Mazzucato
- Section on Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
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210
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Kazyken D, Lentz SI, Wadley M, Fingar DC. Alkaline intracellular pH (pHi) increases PI3K activity to promote mTORC1 and mTORC2 signaling and function during growth factor limitation. J Biol Chem 2023; 299:105097. [PMID: 37507012 PMCID: PMC10477693 DOI: 10.1016/j.jbc.2023.105097] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
The conserved protein kinase mTOR (mechanistic target of rapamycin) responds to diverse environmental cues to control cell metabolism and promote cell growth, proliferation, and survival as part of two multiprotein complexes, mTOR complex 1 (mTORC1) and mTORC2. Our prior work demonstrated that an alkaline intracellular pH (pHi) increases mTORC2 activity and cell survival in complete media in part by activating AMP-activated protein kinase, a kinase best known to sense energetic stress. It is important to note that an alkaline pHi represents an underappreciated hallmark of cancer cells that promotes their oncogenic behaviors. In addition, mechanisms that control mTORC1 and mTORC2 signaling and function remain incompletely defined, particularly in response to stress conditions. Here, we demonstrate that an alkaline pHi increases phosphatidylinositide 3-kinase (PI3K) activity to promote mTORC1 and mTORC2 signaling in the absence of serum growth factors. Alkaline pHi increases mTORC1 activity through PI3K-Akt signaling, which mediates inhibitory phosphorylation of the upstream proteins tuberous sclerosis complex 2 and proline-rich Akt substrate of 40 kDa and dissociates tuberous sclerosis complex from lysosomal membranes, thus enabling Rheb-mediated activation of mTORC1. Thus, alkaline pHi mimics growth factor-PI3K signaling. Functionally, we also demonstrate that an alkaline pHi increases cap-dependent protein synthesis through inhibitory phosphorylation of eIF4E binding protein 1 and suppresses apoptosis in a PI3K- and mTOR-dependent manner. We speculate that an alkaline pHi promotes a low basal level of cell metabolism (e.g., protein synthesis) that enables cancer cells within growing tumors to proliferate and survive despite limiting growth factors and nutrients, in part through elevated PI3K-mTORC1 and/or PI3K-mTORC2 signaling.
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Affiliation(s)
- Dubek Kazyken
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
| | - Stephen I Lentz
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Maxwell Wadley
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Diane C Fingar
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
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211
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Chen Y, Xu Z, Sun H, Ouyang X, Han Y, Yu H, Wu N, Xie Y, Su B. Regulation of CD8 + T memory and exhaustion by the mTOR signals. Cell Mol Immunol 2023; 20:1023-1039. [PMID: 37582972 PMCID: PMC10468538 DOI: 10.1038/s41423-023-01064-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 07/02/2023] [Indexed: 08/17/2023] Open
Abstract
CD8+ T cells are the key executioners of the adaptive immune arm, which mediates antitumor and antiviral immunity. Naïve CD8+ T cells develop in the thymus and are quickly activated in the periphery after encountering a cognate antigen, which induces these cells to proliferate and differentiate into effector cells that fight the initial infection. Simultaneously, a fraction of these cells become long-lived memory CD8+ T cells that combat future infections. Notably, the generation and maintenance of memory cells is profoundly affected by various in vivo conditions, such as the mode of primary activation (e.g., acute vs. chronic immunization) or fluctuations in host metabolic, inflammatory, or aging factors. Therefore, many T cells may be lost or become exhausted and no longer functional. Complicated intracellular signaling pathways, transcription factors, epigenetic modifications, and metabolic processes are involved in this process. Therefore, understanding the cellular and molecular basis for the generation and fate of memory and exhausted CD8+ cells is central for harnessing cellular immunity. In this review, we focus on mammalian target of rapamycin (mTOR), particularly signaling mediated by mTOR complex (mTORC) 2 in memory and exhausted CD8+ T cells at the molecular level.
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Affiliation(s)
- Yao Chen
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ziyang Xu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Hongxiang Sun
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xinxing Ouyang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
- Department of Tumor Biology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yuheng Han
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Haihui Yu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ningbo Wu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Yiting Xie
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and The Ministry of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Department of Tumor Biology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Department of Gastroenterology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
- Shanghai Jiao Tong University School of Medicine-Yale Institute for Immune Metabolism, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Key Laboratory of Molecular Radiation Oncology of Hunan Province, Xiangya Hospital, Central South University, Changsha, China.
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212
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Nicastro R, Brohée L, Alba J, Nüchel J, Figlia G, Kipschull S, Gollwitzer P, Romero-Pozuelo J, Fernandes SA, Lamprakis A, Vanni S, Teleman AA, De Virgilio C, Demetriades C. Malonyl-CoA is a conserved endogenous ATP-competitive mTORC1 inhibitor. Nat Cell Biol 2023; 25:1303-1318. [PMID: 37563253 PMCID: PMC10495264 DOI: 10.1038/s41556-023-01198-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 06/29/2023] [Indexed: 08/12/2023]
Abstract
Cell growth is regulated by the mammalian/mechanistic target of rapamycin complex 1 (mTORC1), which functions both as a nutrient sensor and a master controller of virtually all biosynthetic pathways. This ensures that cells are metabolically active only when conditions are optimal for growth. Notably, although mTORC1 is known to regulate fatty acid biosynthesis, how and whether the cellular lipid biosynthetic capacity signals back to fine-tune mTORC1 activity remains poorly understood. Here we show that mTORC1 senses the capacity of a cell to synthesise fatty acids by detecting the levels of malonyl-CoA, an intermediate of this biosynthetic pathway. We find that, in both yeast and mammalian cells, this regulation is direct, with malonyl-CoA binding to the mTOR catalytic pocket and acting as a specific ATP-competitive inhibitor. When fatty acid synthase (FASN) is downregulated/inhibited, elevated malonyl-CoA levels are channelled to proximal mTOR molecules that form direct protein-protein interactions with acetyl-CoA carboxylase 1 (ACC1) and FASN. Our findings represent a conserved and unique homeostatic mechanism whereby impaired fatty acid biogenesis leads to reduced mTORC1 activity to coordinately link this metabolic pathway to the overall cellular biosynthetic output. Moreover, they reveal the existence of a physiological metabolite that directly inhibits the activity of a signalling kinase in mammalian cells by competing with ATP for binding.
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Affiliation(s)
- Raffaele Nicastro
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Laura Brohée
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Josephine Alba
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Julian Nüchel
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Gianluca Figlia
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
| | | | - Peter Gollwitzer
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Jesus Romero-Pozuelo
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
- Unidad de Investigación Biomedica, Universidad Alfonso X El Sabio (UAX), Madrid, Spain
| | | | - Andreas Lamprakis
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Heidelberg University, Heidelberg, Germany.
| | | | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany.
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany.
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213
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Ruocco C, Malavazos AE, Ragni M, Carruba MO, Valerio A, Iacobellis G, Nisoli E. Amino acids contribute to adaptive thermogenesis. New insights into the mechanisms of action of recent drugs for metabolic disorders are emerging. Pharmacol Res 2023; 195:106892. [PMID: 37619907 DOI: 10.1016/j.phrs.2023.106892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/28/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023]
Abstract
Adaptive thermogenesis is the heat production by muscle contractions (shivering thermogenesis) or brown adipose tissue (BAT) and beige fat (non-shivering thermogenesis) in response to external stimuli, including cold exposure. BAT and beige fat communicate with peripheral organs and the brain through a variegate secretory and absorption processes - controlling adipokines, microRNAs, extracellular vesicles, and metabolites - and have received much attention as potential therapeutic targets for managing obesity-related disorders. The sympathetic nervous system and norepinephrine-releasing adipose tissue macrophages (ATM) activate uncoupling protein 1 (UCP1), expressed explicitly in brown and beige adipocytes, dissolving the electrochemical gradient and uncoupling tricarboxylic acid cycle and the electron transport chain from ATP production. Mounting evidence has attracted attention to the multiple effects of dietary and endogenously synthesised amino acids in BAT thermogenesis and metabolic phenotype in animals and humans. However, the mechanisms implicated in these processes have yet to be conclusively characterized. In the present review article, we aim to define the principal investigation areas in this context, including intestinal microbiota constitution, adipose autophagy modulation, and secretome and metabolic fluxes control, which lead to increased brown/beige thermogenesis. Finally, also based on our recent epicardial adipose tissue results, we summarise the evidence supporting the notion that the new dual and triple agonists of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon (GCG) receptor - with never before seen weight loss and insulin-sensitizing efficacy - promote thermogenic-like amino acid profiles in BAT with robust heat production and likely trigger sympathetic activation and adaptive thermogenesis by controlling amino acid metabolism and ATM expansion in BAT and beige fat.
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Affiliation(s)
- Chiara Ruocco
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy
| | - Alexis Elias Malavazos
- Endocrinology Unit, Clinical Nutrition and Cardiovascular Prevention Service, IRCCS Policlinico San Donato, Piazza Edmondo Malan, 2, San Donato Milanese, 20097 Milan, Italy; Department of Biomedical, Surgical and Dental Sciences, University of Milan, via della Commenda, 10, 20122 Milan, Italy
| | - Maurizio Ragni
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy
| | - Michele O Carruba
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy
| | - Alessandra Valerio
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa, 11, 25123 Brescia, Italy
| | - Gianluca Iacobellis
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami, 1400 NW 12th Ave, Miami, FL, USA
| | - Enzo Nisoli
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy.
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214
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de Wet S, Theart R, Loos B. Cogs in the autophagic machine-equipped to combat dementia-prone neurodegenerative diseases. Front Mol Neurosci 2023; 16:1225227. [PMID: 37720551 PMCID: PMC10500130 DOI: 10.3389/fnmol.2023.1225227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/31/2023] [Indexed: 09/19/2023] Open
Abstract
Neurodegenerative diseases are often characterized by hydrophobic inclusion bodies, and it may be the case that the aggregate-prone proteins that comprise these inclusion bodies are in fact the cause of neurotoxicity. Indeed, the appearance of protein aggregates leads to a proteostatic imbalance that causes various interruptions in physiological cellular processes, including lysosomal and mitochondrial dysfunction, as well as break down in calcium homeostasis. Oftentimes the approach to counteract proteotoxicity is taken to merely upregulate autophagy, measured by an increase in autophagosomes, without a deeper assessment of contributors toward effective turnover through autophagy. There are various ways in which autophagy is regulated ranging from the mammalian target of rapamycin (mTOR) to acetylation status of proteins. Healthy mitochondria and the intracellular energetic charge they preserve are key for the acidification status of lysosomes and thus ensuring effective clearance of components through the autophagy pathway. Both mitochondria and lysosomes have been shown to bear functional protein complexes that aid in the regulation of autophagy. Indeed, it may be the case that minimizing the proteins associated with the respective neurodegenerative pathology may be of greater importance than addressing molecularly their resulting inclusion bodies. It is in this context that this review will dissect the autophagy signaling pathway, its control and the manner in which it is molecularly and functionally connected with the mitochondrial and lysosomal system, as well as provide a summary of the role of autophagy dysfunction in driving neurodegenerative disease as a means to better position the potential of rapamycin-mediated bioactivities to control autophagy favorably.
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Affiliation(s)
- Sholto de Wet
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Rensu Theart
- Department of Electric and Electronic Engineering, Stellenbosch University, Stellenbosch, South Africa
| | - Ben Loos
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
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215
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Freitas RVDM, de Freitas DLD, de Oliveira IRD, Dos Santos Gomes C, Guerra GCB, Dantas PMS, da Silva TG, Duque G, de Lima KMG, Guerra RO. Fourier-Transform Infrared Spectroscopy as a Screening Tool for Osteosarcopenia in Community-Dwelling Older Women. J Gerontol A Biol Sci Med Sci 2023; 78:1543-1549. [PMID: 36905160 DOI: 10.1093/gerona/glad081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Indexed: 03/12/2023] Open
Abstract
Osteosarcopenia is a complex geriatric syndrome characterized by the presence of both sarcopenia and osteopenia/osteoporosis. This condition increases rates of disability, falls, fractures, mortality, and mobility impairments in older adults. The purpose of this study was to analyze the Fourier-transform infrared (FTIR) spectroscopy diagnostic power for osteosarcopenia in community-dwelling older women (n = 64; 32 osteosarcopenic and 32 non-osteosarcopenia). FTIR is a fast and reproducible technique highly sensitive to biological tissues, and a mathematical model was created using multivariate classification techniques that denoted the graphic spectra of the molecular groups. Genetic algorithm and support vector machine regression (GA-SVM) was the most feasible model, achieving 80.0% of accuracy. GA-SVM identified 15 wave numbers responsible for class differentiation, in which several amino acids (responsible for the proper activation of the mammalian target of rapamycin) and hydroxyapatite (an inorganic bone component) were observed. Imaging tests and low availability of instruments that allow the observation of osteosarcopenia involve high health costs for patients and restrictive indications. Therefore, FTIR can be used to diagnose osteosarcopenia due to its efficiency and low cost and to enable early detection in geriatric services, contributing to advances in science and technology that are potential "conventional" methods in the future.
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Affiliation(s)
| | | | | | | | | | - Paulo Moreira Silva Dantas
- Postgraduation Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil
- Postgraduation Program in Physical Education, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Tales Gomes da Silva
- Institute of Chemistry, Biological Chemistry and Chemometrics, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Gustavo Duque
- Department of Medicine, McGill University, Montreal, Quebec, Canada
- Bone, Muscle & Geroscience Group, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Kassio Michell Gomes de Lima
- Institute of Chemistry, Biological Chemistry and Chemometrics, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Ricardo Oliveira Guerra
- Postgraduation Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil
- Postgraduation Program in Physiotherapy, Federal University of Rio Grande do Norte, Natal, Brazil
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216
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Xu M, Zhong XZ, Huang P, Jaślan D, Wang P, Sun X, Weiden EM, EL Hiani Y, Grimm C, Dong XP. TRPML3/BK complex promotes autophagy and bacterial clearance by providing a positive feedback regulation of mTOR via PI3P. Proc Natl Acad Sci U S A 2023; 120:e2215777120. [PMID: 37585464 PMCID: PMC10450854 DOI: 10.1073/pnas.2215777120] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 06/22/2023] [Indexed: 08/18/2023] Open
Abstract
TRPML3 is a Ca2+/Na+ release channel residing in both phagophores and endolysosomal membranes. It is activated by PI3P and PI3,5P2. Its activity can be enhanced by high luminal pH and by replacing luminal Na+ with K+. Here, we report that big-conductance Ca2+-activated potassium (BK) channels form a positive feedback loop with TRPML3. Ca2+ release via TRPML3 activates BK, which in turn facilitates TRPML3-mediated Ca2+ release, potentially through removing luminal Na+ inhibition. We further show that TRPML3/BK and mammalian target of rapamycin (mTOR) form another positive feedback loop to facilitate autophagy induction in response to nutrient starvation, i.e., mTOR inhibition upon nutrient starvation activates TRPML3/BK, and this further reduces mTOR activity, thereby increasing autophagy induction. Mechanistically, the feedback regulation between TRPML3/BK and mTOR is mediated by PI3P, an endogenous TRPML3 activator that is enriched in phagophores and is up-regulated by mTOR reduction. Importantly, bacterial infection activates TRPML3 in a BK-dependent manner, and both TRPML3 and BK are required for mTOR suppression and autophagy induction responding to bacterial infection. Suppressing either TRPML3 or BK helps bacteria survival whereas increasing either TRPML3 or BK favors bacterial clearance. Considering that TRPML3/BK is inhibited by low luminal pH but activated by high luminal pH and PI3P in phagophores, we suggest that TRPML3/BK and mTOR form a positive feedback loop via PI3P to ensure efficient autophagy induction in response to nutrient deprivation and bacterial infection. Our study reveals a role of TRPML3-BK coupling in controlling cellular homeostasis and intracellular bacterial clearance via regulating mTOR signaling.
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Affiliation(s)
- Mengnan Xu
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Xi Zoë Zhong
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Peng Huang
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
- Chongming Hospital, Shanghai University of Medicine and Health Sciences, Shanghai202150, China
| | - Dawid Jaślan
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
| | - Pingping Wang
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Xue Sun
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
- Department of Developmental Cell Biology, China Medical University, Shenbei New District, Shenyang110122, China
| | - Eva-Maria Weiden
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
| | - Yassine EL Hiani
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich80336, Germany
- Immunology, Infection and Pandemic Research, Fraunhofer Institute for Translational Medicine and Pharmacology, Munich80799, Germany
| | - Xian-Ping Dong
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NSB3H 4R2, Canada
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217
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Xu C, Pan X, Wang D, Guan Y, Yang W, Chen X, Liu Y. O-GlcNAcylation of Raptor transduces glucose signals to mTORC1. Mol Cell 2023; 83:3027-3040.e11. [PMID: 37541260 DOI: 10.1016/j.molcel.2023.07.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 05/23/2023] [Accepted: 07/11/2023] [Indexed: 08/06/2023]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) regulates metabolism and cell growth in response to nutrient levels. Dysregulation of mTORC1 results in a broad spectrum of diseases. Glucose is the primary energy supply of cells, and therefore, glucose levels must be accurately conveyed to mTORC1 through highly responsive signaling mechanisms to control mTORC1 activity. Here, we report that glucose-induced mTORC1 activation is regulated by O-GlcNAcylation of Raptor, a core component of mTORC1, in HEK293T cells. Mechanistically, O-GlcNAcylation of Raptor at threonine 700 facilitates the interactions between Raptor and Rag GTPases and promotes the translocation of mTOR to the lysosomal surface, consequently activating mTORC1. In addition, we show that AMPK-mediated phosphorylation of Raptor suppresses Raptor O-GlcNAcylation and inhibits Raptor-Rags interactions. Our findings reveal an exquisitely controlled mechanism, which suggests how glucose coordinately regulates cellular anabolism and catabolism.
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Affiliation(s)
- Chenchen Xu
- State Key Laboratory of Membrane Biology, New Cornerstone Science Laboratory, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
| | - Xiaoqing Pan
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Dong Wang
- State Key Laboratory of Membrane Biology, New Cornerstone Science Laboratory, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
| | - Yuanyuan Guan
- State Key Laboratory of Membrane Biology, New Cornerstone Science Laboratory, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
| | - Wenyu Yang
- Yuan Pei College, Peking University, Beijing 100871, China
| | - Xing Chen
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China; Synthetic and Functional Biomolecules Center, Peking University, Beijing 100871, China; Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing 100871, China.
| | - Ying Liu
- State Key Laboratory of Membrane Biology, New Cornerstone Science Laboratory, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Beijing Advanced Innovation Center for Genomics, Beijing 100871, China.
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218
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Fallone L, Walzer T, Marçais A. Signaling Pathways Leading to mTOR Activation Downstream Cytokine Receptors in Lymphocytes in Health and Disease. Int J Mol Sci 2023; 24:12736. [PMID: 37628917 PMCID: PMC10454121 DOI: 10.3390/ijms241612736] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
CD8+ T cells and Natural Killer (NK) cells are cytotoxic lymphocytes important in the response to intracellular pathogens and cancer. Their activity depends on the integration of a large set of intracellular and environmental cues, including antigenic signals, cytokine stimulation and nutrient availability. This integration is achieved by signaling hubs, such as the mechanistic target of rapamycin (mTOR). mTOR is a conserved protein kinase that controls cellular growth and metabolism in eukaryotic cells and, therefore, is essential for lymphocyte development and maturation. However, our current understanding of mTOR signaling comes mostly from studies performed in transformed cell lines, which constitute a poor model for comprehending metabolic pathway regulation. Therefore, it is only quite recently that the regulation of mTOR in primary cells has been assessed. Here, we review the signaling pathways leading to mTOR activation in CD8+ T and NK cells, focusing on activation by cytokines. We also discuss how this knowledge can contribute to immunotherapy development, particularly for cancer treatment.
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Affiliation(s)
| | | | - Antoine Marçais
- CIRI—Centre International de Recherche en Infectiologie (Team Lyacts), Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007 Lyon, France; (L.F.); (T.W.)
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219
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Li B, Khan MZ, Khan IM, Ullah Q, Cisang ZM, Zhang N, Wu D, Huang B, Ma Y, Khan A, Jiang N, Zahoor M. Genetics, environmental stress, and amino acid supplementation affect lactational performance via mTOR signaling pathway in bovine mammary epithelial cells. Front Genet 2023; 14:1195774. [PMID: 37636261 PMCID: PMC10448190 DOI: 10.3389/fgene.2023.1195774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/26/2023] [Indexed: 08/29/2023] Open
Abstract
Mammary glands are known for their ability to convert nutrients present in the blood into milk contents. In cows, milk synthesis and the proliferation of cow mammary epithelial cells (CMECs) are regulated by various factors, including nutrients such as amino acids and glucose, hormones, and environmental stress. Amino acids, in particular, play a crucial role in regulating cell proliferation and casein synthesis in mammalian epithelial cells, apart from being building blocks for protein synthesis. Studies have shown that environmental factors, particularly heat stress, can negatively impact milk production performance in dairy cattle. The mammalian target of rapamycin complex 1 (mTORC1) pathway is considered the primary signaling pathway involved in regulating cell proliferation and milk protein and fat synthesis in cow mammary epithelial cells in response to amino acids and heat stress. Given the significant role played by the mTORC signaling pathway in milk synthesis and cell proliferation, this article briefly discusses the main regulatory genes, the impact of amino acids and heat stress on milk production performance, and the regulation of mTORC signaling pathway in cow mammary epithelial cells.
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Affiliation(s)
- Bin Li
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Muhammad Zahoor Khan
- Liaocheng Research Institute of Donkey High‐Efficiency Breeding and Ecological Feeding, Agricultural Science and Engineering School, Liaocheng University, Liaocheng, China
- Faculty of Veterinary and Animal Sciences, The University of Agriculture, Dera Ismail Khan, Pakistan
| | - Ibrar Muhammad Khan
- Anhui Province Key Laboratory of Embryo Development and Reproduction Regulation, Anhui Province Key Laboratory of Environmental Hormone and Reproduction, School of Biological and Food Engineering, Fuyang Normal University, Fuyang, China
| | - Qudrat Ullah
- Faculty of Veterinary and Animal Sciences, The University of Agriculture, Dera Ismail Khan, Pakistan
| | - Zhuo-Ma Cisang
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Nan Zhang
- Tibet Autonomous Region Animal Husbandry Station, Lhasa, China
| | - Dan Wu
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Bingjian Huang
- Liaocheng Research Institute of Donkey High‐Efficiency Breeding and Ecological Feeding, Agricultural Science and Engineering School, Liaocheng University, Liaocheng, China
- College of Life Sciences, Liaocheng University, Liaocheng, China
| | - Yulin Ma
- State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Adnan Khan
- Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Nan Jiang
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Muhammad Zahoor
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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220
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Tang X, Balachandran RC, Aschner M, Bowman AB. IGF/mTORC1/S6 Signaling Is Potentiated and Prolonged by Acute Loading of Subtoxicological Manganese Ion. Biomolecules 2023; 13:1229. [PMID: 37627294 PMCID: PMC10452562 DOI: 10.3390/biom13081229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
The insulin-like growth factor (IGF)/insulin signaling (IIS) pathway is involved in cellular responses against intracellular divalent manganese ion (Mn2+) accumulation. As a pathway where multiple nodes utilize Mn2+ as a metallic co-factor, how the IIS signaling patterns are affected by Mn2+ overload is unresolved. In our prior studies, acute Mn2+ exposure potentiated IIS kinase activity upon physiological-level stimulation, indicated by elevated phosphorylation of protein kinase B (PKB, also known as AKT). AKT phosphorylation is associated with IIS activity; and provides direct signaling transduction input for the mammalian target of rapamycin complex 1 (mTORC1) and its downstream target ribosomal protein S6 (S6). Here, to better define the impact of Mn2+ exposure on IIS function, Mn2+-induced IIS activation was evaluated with serial concentrations and temporal endpoints. In the wild-type murine striatal neuronal line STHdh, the acute treatment of Mn2+ with IGF induced a Mn2+ concentration-sensitive phosphorylation of S6 at Ser235/236 to as low as 5 μM extracellular Mn2+. This effect required both the essential amino acids and insulin receptor (IR)/IGF receptor (IGFR) signaling input. Similar to simultaneous stimulation of Mn2+ and IGF, when a steady-state elevation of Mn2+ was established via a 24-h pre-exposure, phosphorylation of S6 also displayed higher sensitivity to sub-cytotoxic Mn2+ when compared to AKT phosphorylation at Ser473. This indicates a synergistic effect of sub-cytotoxic Mn2+ on IIS and mTORC1 signaling. Furthermore, elevated intracellular Mn2+, with both durations, led to a prolonged activation in AKT and S6 upon stimulation. Our data demonstrate that the downstream regulator S6 is a highly sensitive target of elevated Mn2+ and is well below the established acute cytotoxicity thresholds (<50 μM). These findings indicate that the IIS/mTORC1 pathways, in which Mn2+ normally serves as an essential co-factor, are dually responsible for the cellular changes in exposures to real-world Mn2+ concentrations.
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Affiliation(s)
- Xueqi Tang
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
| | - Rekha C. Balachandran
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
- Exponent Inc., Alexandria, VA 22314, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Aaron B. Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
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221
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Gargalionis AN, Papavassiliou KA, Papavassiliou AG. Implication of mTOR Signaling in NSCLC: Mechanisms and Therapeutic Perspectives. Cells 2023; 12:2014. [PMID: 37566093 PMCID: PMC10416991 DOI: 10.3390/cells12152014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/28/2023] [Accepted: 08/06/2023] [Indexed: 08/12/2023] Open
Abstract
Mechanistic target of the rapamycin (mTOR) signaling pathway represents a central cellular kinase that controls cell survival and metabolism. Increased mTOR activation, along with upregulation of respective upstream and downstream signaling components, have been established as oncogenic features in cancer cells in various tumor types. Nevertheless, mTOR pathway therapeutic targeting has been proven to be quite challenging in various clinical settings. Non-small cell lung cancer (NSCLC) is a frequent type of solid tumor in both genders, where aberrant regulation of the mTOR pathway contributes to the development of oncogenesis, apoptosis resistance, angiogenesis, cancer progression, and metastasis. In this context, the outcome of mTOR pathway targeting in clinical trials still demonstrates unsatisfactory results. Herewith, we discuss recent findings regarding the mechanisms and therapeutic targeting of mTOR signaling networks in NSCLC, as well as future perspectives for the efficient application of treatments against mTOR and related protein molecules.
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Affiliation(s)
- Antonios N. Gargalionis
- Department of Biopathology, ‘Eginition’ Hospital, Medical School, National and Kapodistrian University of Athens, 11528 Athens, Greece;
| | - Kostas A. Papavassiliou
- First University Department of Respiratory Medicine, ‘Sotiria’ Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Athanasios G. Papavassiliou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
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222
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Li MX, Wu XT, Jing WQ, Hou WK, Hu S, Yan W. Inosine enhances tumor mitochondrial respiration by inducing Rag GTPases and nascent protein synthesis under nutrient starvation. Cell Death Dis 2023; 14:492. [PMID: 37532694 PMCID: PMC10397262 DOI: 10.1038/s41419-023-06017-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/20/2023] [Accepted: 07/25/2023] [Indexed: 08/04/2023]
Abstract
Metabolic heterogeneity of tumor microenvironment (TME) is a hallmark of cancer and a big barrier to cancer treatment. Cancer cells display diverse capacities to utilize alternative carbon sources, including nucleotides, under poor nutrient circumstances. However, whether and how purine, especially inosine, regulates mitochondrial metabolism to buffer nutrient starvation has not been well-defined yet. Here, we identify the induction of 5'-nucleotidase, cytosolic II (NT5C2) gene expression promotes inosine accumulation and maintains cancer cell survival in the nutrient-poor region. Inosine elevation further induces Rag GTPases abundance and mTORC1 signaling pathway by enhancing transcription factor SP1 level in the starved tumor. Besides, inosine supplementary stimulates the synthesis of nascent TCA cycle enzymes, including citrate synthesis (CS) and aconitase 1 (ACO1), to further enhance oxidative phosphorylation of breast cancer cells under glucose starvation, leading to the accumulation of iso-citric acid. Inhibition of the CS activity or knockdown of ACO1 blocks the rescue effect of inosine on cancer survival under starvation. Collectively, our finding highlights the vital signal role of inosine linking mitochondrial respiration and buffering starvation, beyond serving as direct energy carriers or building blocks for genetic code in TME, shedding light on future cancer treatment by targeting inosine metabolism.
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Affiliation(s)
- Mei-Xin Li
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei, 430072, China
| | - Xiao-Ting Wu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei, 430072, China
| | - Wen-Qiang Jing
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei, 430072, China
| | - Wen-Kui Hou
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei, 430072, China
| | - Sheng Hu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei, 430072, China
| | - Wei Yan
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, Hubei, 430072, China.
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223
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Zhulyn O, Rosenblatt HD, Shokat L, Dai S, Kuzuoglu-Öztürk D, Zhang Z, Ruggero D, Shokat KM, Barna M. Evolutionarily divergent mTOR remodels translatome for tissue regeneration. Nature 2023; 620:163-171. [PMID: 37495694 PMCID: PMC11181899 DOI: 10.1038/s41586-023-06365-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 06/22/2023] [Indexed: 07/28/2023]
Abstract
An outstanding mystery in biology is why some species, such as the axolotl, can regenerate tissues whereas mammals cannot1. Here, we demonstrate that rapid activation of protein synthesis is a unique feature of the injury response critical for limb regeneration in the axolotl (Ambystoma mexicanum). By applying polysome sequencing, we identify hundreds of transcripts, including antioxidants and ribosome components that are selectively activated at the level of translation from pre-existing messenger RNAs in response to injury. By contrast, protein synthesis is not activated in response to non-regenerative digit amputation in the mouse. We identify the mTORC1 pathway as a key upstream signal that mediates tissue regeneration and translational control in the axolotl. We discover unique expansions in mTOR protein sequence among urodele amphibians. By engineering an axolotl mTOR (axmTOR) in human cells, we show that these changes create a hypersensitive kinase that allows axolotls to maintain this pathway in a highly labile state primed for rapid activation. This change renders axolotl mTOR more sensitive to nutrient sensing, and inhibition of amino acid transport is sufficient to inhibit tissue regeneration. Together, these findings highlight the unanticipated impact of the translatome on orchestrating the early steps of wound healing in a highly regenerative species and provide a missing link in our understanding of vertebrate regenerative potential.
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Affiliation(s)
- Olena Zhulyn
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Developmental and Stem Cell Biology Program, SickKids Research Institute, Toronto, Ontario, Canada
| | - Hannah D Rosenblatt
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Developmental Biology, Stanford University, Stanford, CA, USA
| | - Leila Shokat
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Shizhong Dai
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Duygu Kuzuoglu-Öztürk
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
| | - Zijian Zhang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA
| | - Davide Ruggero
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| | - Maria Barna
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
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Fang Z, Xu Y, Liu G, Shao Q, Niu X, Tai W, Shen T, Fan M, Chen M, Lei L, Gao W, Song Y, Wang Z, Du X, Li X. Narirutin activates TFEB (transcription factor EB) to protect against Acetaminophen-induced liver injury by targeting PPP3/calcineurin. Autophagy 2023; 19:2240-2256. [PMID: 36779633 PMCID: PMC10351474 DOI: 10.1080/15548627.2023.2179781] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/14/2023] Open
Abstract
Acetaminophen (APAP) overdose is the predominant cause of drug-induced liver injury worldwide. The macroautophagy/autophagy-lysosomal pathway (ALP) is involved in the APAP hepatotoxicity. TFEB (transcription factor EB) promotes the expression of genes related to autophagy and lysosomal biogenesis, thus, pharmacological activation of TFEB-mediated ALP may be an effective therapeutic approach for treating APAP-induced liver injury. We aimed to reveal the effects of narirutin (NR), the main bioactive constituents isolated from citrus peels, on APAP hepatotoxicity and to explore its underlying mechanism. Administration of NR enhanced activities of antioxidant enzymes, improved mitochondrial dysfunction and alleviated liver injury in APAP-treated mice, whereas NR did not affect APAP metabolism and MAPK/JNK activation. NR enhanced TFEB transcriptional activity and activated ALP in an MTOR complex 1 (MTORC1)-independent but PPP3/calcineurin-dependent manner. Moreover, knockout of Tfeb or knockdown of PPP3CB/CNA2 (protein phosphatase 3, catalytic subunit, beta isoform) in the liver abolished the beneficial effects of NR on APAP overdose. Mechanistically, NR bound to PPP3CB via PRO31, LYS61 and PRO347 residues and enhanced PPP3/calcineurin activity, thereby eliciting dephosphorylation of TFEB and promoting ALP, which alleviated APAP-induced oxidative stress and liver injury. Together, NR protects against APAP-induced liver injury by activating a PPP3/calcineurin-TFEB-ALP axis, indicating NR may be a potential agent for treating APAP overdose.Abbreviations: ALP: autophagy-lysosomal pathway; APAP: acetaminophen; APAP-AD: APAP-protein adducts; APAP-Cys: acetaminophen-cysteine adducts; CAT: catalase; CETSA: cellular thermal shift assay; CQ: chloroquine; CYP2E1: cytochrome P450, family 2, subfamily e, polypeptide 1; CYCS/Cyt c: cytochrome c, somatic; DARTS: drug affinity responsive target stability assay; ENGASE/NAG: endo-beta-N-acetylglucosaminidase; GOT1/AST: glutamic-oxaloacetic transaminase 1, soluble; GPT/ALT: glutamic pyruvic transaminase, soluble; GSH: glutathione; GPX/GSH-Px: glutathione peroxidase; KD: dissociation constant; Leu: leupeptin; MCOLN1: mucolipin 1; MTORC1: MTOR complex 1; NAC: N-acetylcysteine; NAPQI: N-acetyl-p-benzoquinoneimine; NFAT: nuclear factor of activated T cells; NR: narirutin; OA: okadaic acid; RRAG: Ras related GTP binding; ROS: reactive oxygen species; PPP3CB/CNA2: protein phosphatase 3, catalytic subunit, beta isoform; PPP3R1/CNB1: protein phosphatase 3, regulatory subunit B, alpha isoform (calcineurin B, type I); SOD: superoxide dismutase; SPR: surface plasmon resonance analysis; TFEB: transcription factor EB.
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Affiliation(s)
- Zhiyuan Fang
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Yanyong Xu
- Key Laboratory of Metabolism and Molecular Medicine of the Ministry of Education, Department of Pathology of School of Basic Medical Sciences, Fudan University, Shanghai, China
- Frontier Innovation Center, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Guowen Liu
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Qi Shao
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Xiaodi Niu
- College of Food Science and Engineering, Jilin University, Changchun, China
| | - Wenjun Tai
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Taiyu Shen
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Minghe Fan
- Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Meng Chen
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Lin Lei
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Wenwen Gao
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Yuxiang Song
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Zhe Wang
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Xiliang Du
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
| | - Xinwei Li
- State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, ChangchunJilin, China
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225
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Kanzaki K, Wada M. Effects of Leucine Ingestion and Contraction on the Sestrin/GATOR2 Pathway and mTORC1 Activation in Rat Fast-Twitch muscle. J Nutr 2023; 153:2228-2236. [PMID: 37328110 DOI: 10.1016/j.tjnut.2023.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/05/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND Leucine activates the mechanistic/mammalian target of rapamycin complex 1 (mTORC1) in mammalian skeletal muscle. Recent studies have shown that Sestrin, a leucine sensor, might play a role in this process. However, it remains unknown whether Sestrin dissociates from GATOR2 in a dose- and time-dependent manner and whether an acute bout of muscle contraction augments this dissociation. OBJECTIVE This study aimed to examine the effects of leucine ingestion and muscle contraction on the interaction between Sestrin1/2 and GATOR2 and on mTORC1 activation. METHODS Male Wistar rats were randomly assigned to control (C), leucine 3 (L3), or leucine 10 (L10) groups. Intact gastrocnemius muscles were subjected to 30 repetitive unilateral contractions. The L3 and L10 groups were then orally administered 3 and 10 mmol/kg body weight of L-leucine 2 h after the end of the contractions, respectively. Blood and muscle samples were collected 30, 60, or 120 min after the administration. RESULTS The blood and muscle leucine concentrations increased in a dose-dependent manner. The ratio of phosphorylated ribosomal protein S6 kinase (S6K) to total S6K (which indicates mTORC1 signaling activation) was markedly increased by muscle contraction and increased in a dose-dependent manner only in rested muscle. Leucine ingestion but not muscle contraction increased Sestrin1 dissociation from GATOR2 and Sestrin2 association with GATOR2. A negative relationship was observed between the blood and muscle leucine concentrations and the Sestrin1 association with GATOR2. CONCLUSIONS The results suggest that Sestrin1, but not Sestrin2, regulates leucine-related mTORC1 activation via its dissociation from GATOR2 and that acute exercise-induced mTORC1 activation involves pathways other than the leucine-related Sestrin1/GATOR2 pathway.
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Affiliation(s)
- Keita Kanzaki
- Department of Clinical Nutrition, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Okayama, Japan.
| | - Masanobu Wada
- Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima, Japan
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226
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Terrell JR, Taylor SJ, Schneider AL, Lu Y, Vernon TN, Xhani S, Gumpper RH, Luo M, Wilson WD, Steidl U, Poon GMK. DNA selection by the master transcription factor PU.1. Cell Rep 2023; 42:112671. [PMID: 37352101 PMCID: PMC10479921 DOI: 10.1016/j.celrep.2023.112671] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 04/07/2023] [Accepted: 06/02/2023] [Indexed: 06/25/2023] Open
Abstract
The master transcriptional regulator PU.1/Spi-1 engages DNA sites with affinities spanning multiple orders of magnitude. To elucidate this remarkable plasticity, we have characterized 22 high-resolution co-crystallographic PU.1/DNA complexes across the addressable affinity range in myeloid gene transactivation. Over a purine-rich core (such as 5'-GGAA-3') flanked by variable sequences, affinity is negotiated by direct readout on the 5' flank via a critical glutamine (Q226) sidechain and by indirect readout on the 3' flank by sequence-dependent helical flexibility. Direct readout by Q226 dynamically specifies PU.1's characteristic preference for purines and explains the pathogenic mutation Q226E in Waldenström macroglobulinemia. The structures also reveal how disruption of Q226 mediates strand-specific inhibition by DNA methylation and the recognition of non-canonical sites, including the authentic binding sequence at the CD11b promoter. A re-synthesis of phylogenetic and structural data on the ETS family, considering the centrality of Q226 in PU.1, unifies the model of DNA selection by ETS proteins.
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Affiliation(s)
- J Ross Terrell
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Samuel J Taylor
- Departments of Cell Biology, Oncology, and Medicine, Ruth L. and David S. Gottesman Institute for Stem Cell Research and Regenerative Medicine, Blood Cancer Institute, and the Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Amelia L Schneider
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Yue Lu
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Tyler N Vernon
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Suela Xhani
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Ryan H Gumpper
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Ming Luo
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA; Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA
| | - W David Wilson
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA; Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA
| | - Ulrich Steidl
- Departments of Cell Biology, Oncology, and Medicine, Ruth L. and David S. Gottesman Institute for Stem Cell Research and Regenerative Medicine, Blood Cancer Institute, and the Montefiore Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Gregory M K Poon
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA; Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
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227
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Gao Y, Tian T. mTOR Signaling Pathway and Gut Microbiota in Various Disorders: Mechanisms and Potential Drugs in Pharmacotherapy. Int J Mol Sci 2023; 24:11811. [PMID: 37511569 PMCID: PMC10380532 DOI: 10.3390/ijms241411811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/15/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
The mammalian or mechanistic target of rapamycin (mTOR) integrates multiple intracellular and extracellular upstream signals involved in the regulation of anabolic and catabolic processes in cells and plays a key regulatory role in cell growth and metabolism. The activation of the mTOR signaling pathway has been reported to be associated with a wide range of human diseases. A growing number of in vivo and in vitro studies have demonstrated that gut microbes and their complex metabolites can regulate host metabolic and immune responses through the mTOR pathway and result in disorders of host physiological functions. In this review, we summarize the regulatory mechanisms of gut microbes and mTOR in different diseases and discuss the crosstalk between gut microbes and their metabolites and mTOR in disorders in the gastrointestinal tract, liver, heart, and other organs. We also discuss the promising application of multiple potential drugs that can adjust the gut microbiota and mTOR signaling pathways. Despite the limited findings between gut microbes and mTOR, elucidating their relationship may provide new clues for the prevention and treatment of various diseases.
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Affiliation(s)
- Yuan Gao
- College of Life Science and Bioengineering, Beijing Jiaotong University, Beijing 100044, China
| | - Tian Tian
- College of Life Science and Bioengineering, Beijing Jiaotong University, Beijing 100044, China
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228
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Al-Refaie N, Padovani F, Binando F, Hornung J, Zhao Q, Towbin BD, Cenik ES, Stroustrup N, Schmoller KM, Cabianca DS. An mTOR/RNA pol I axis shapes chromatin architecture in response to fasting. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.22.550032. [PMID: 37503059 PMCID: PMC10370172 DOI: 10.1101/2023.07.22.550032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Chromatin architecture is a fundamental mediator of genome function. Fasting is a major environmental cue across the animal kingdom. Yet, how it impacts on 3D genome organization is unknown. Here, we show that fasting induces a reversible and large-scale spatial reorganization of chromatin in C. elegans . This fasting-induced 3D genome reorganization requires inhibition of the nutrient-sensing mTOR pathway, a major regulator of ribosome biogenesis. Remarkably, loss of transcription by RNA Pol I, but not RNA Pol II nor Pol III, induces a similar 3D genome reorganization in fed animals, and prevents the restoration of the fed-state architecture upon restoring nutrients to fasted animals. Our work documents the first large-scale chromatin reorganization triggered by fasting and reveals that mTOR and RNA Pol I shape genome architecture in response to nutrients.
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229
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Shi F, Collins S. Regulation of mTOR Signaling: Emerging Role of Cyclic Nucleotide-Dependent Protein Kinases and Implications for Cardiometabolic Disease. Int J Mol Sci 2023; 24:11497. [PMID: 37511253 PMCID: PMC10380887 DOI: 10.3390/ijms241411497] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/07/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) kinase is a central regulator of cell growth and metabolism. It is the catalytic subunit of two distinct large protein complexes, mTOR complex 1 (mTORC1) and mTORC2. mTOR activity is subjected to tight regulation in response to external nutrition and growth factor stimulation. As an important mechanism of signaling transduction, the 'second messenger' cyclic nucleotides including cAMP and cGMP and their associated cyclic nucleotide-dependent kinases, including protein kinase A (PKA) and protein kinase G (PKG), play essential roles in mediating the intracellular action of a variety of hormones and neurotransmitters. They have also emerged as important regulators of mTOR signaling in various physiological and disease conditions. However, the mechanism by which cAMP and cGMP regulate mTOR activity is not completely understood. In this review, we will summarize the earlier work establishing the ability of cAMP to dampen mTORC1 activation in response to insulin and growth factors and then discuss our recent findings demonstrating the regulation of mTOR signaling by the PKA- and PKG-dependent signaling pathways. This signaling framework represents a new non-canonical regulation of mTOR activity that is independent of AKT and could be a novel mechanism underpinning the action of a variety of G protein-coupled receptors that are linked to the mTOR signaling network. We will further review the implications of these signaling events in the context of cardiometabolic disease, such as obesity, non-alcoholic fatty liver disease, and cardiac remodeling. The metabolic and cardiac phenotypes of mouse models with targeted deletion of Raptor and Rictor, the two essential components for mTORC1 and mTORC2, will be summarized and discussed.
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Affiliation(s)
- Fubiao Shi
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sheila Collins
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
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230
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Marques-Ramos A, Cervantes R. Expression of mTOR in normal and pathological conditions. Mol Cancer 2023; 22:112. [PMID: 37454139 PMCID: PMC10349476 DOI: 10.1186/s12943-023-01820-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 07/08/2023] [Indexed: 07/18/2023] Open
Abstract
The mechanistic/mammalian target of rapamycin (mTOR), a protein discovered in 1991, integrates a complex pathway with a key role in maintaining cellular homeostasis. By comprising two functionally distinct complexes, mTOR complex 1 (mTORC1) and mTORC2, it is a central cellular hub that integrates intra- and extracellular signals of energy, nutrient, and hormone availability, modulating the molecular responses to acquire a homeostatic state through the regulation of anabolic and catabolic processes. Accordingly, dysregulation of mTOR pathway has been implicated in a variety of human diseases. While major advances have been made regarding the regulators and effectors of mTOR signaling pathway, insights into the regulation of mTOR gene expression are beginning to emerge. Here, we present the current available data regarding the mTOR expression regulation at the level of transcription, translation and mRNA stability and systematize the current knowledge about the fluctuations of mTOR expression observed in several diseases, both cancerous and non-cancerous. In addition, we discuss whether mTOR expression changes can be used as a biomarker for diagnosis, disease progression, prognosis and/or response to therapeutics. We believe that our study will contribute for the implementation of new disease biomarkers based on mTOR as it gives an exhaustive perspective about the regulation of mTOR gene expression in both normal and pathological conditions.
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Affiliation(s)
- A Marques-Ramos
- H&TRC-Health & Technology Research Center, ESTeSL-Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal.
| | - R Cervantes
- H&TRC-Health & Technology Research Center, ESTeSL-Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, Lisbon, Portugal
- Public Health Research Centre, NOVA National School of Public Health, Universidade Nova de Lisboa, Lisbon, Portugal
- Comprehensive Health Research Center (CHRC), Lisbon, Portugal
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231
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Nikolka F, Karagöz MS, Nassef MZ, Hiller K, Steinert M, Cordes T. The Virulence Factor Macrophage Infectivity Potentiator (Mip) Influences Branched-Chain Amino Acid Metabolism and Pathogenicity of Legionella pneumophila. Metabolites 2023; 13:834. [PMID: 37512541 PMCID: PMC10386555 DOI: 10.3390/metabo13070834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/15/2023] [Accepted: 07/03/2023] [Indexed: 07/30/2023] Open
Abstract
Legionella pneumophila (Lp) is a common etiological agent of bacterial pneumonia that causes Legionnaires' disease (LD). The bacterial membrane-associated virulence factor macrophage infectivity potentiator (Mip) exhibits peptidyl-prolyl-cis/trans-isomerase (PPIase) activity and contributes to the intra- and extracellular pathogenicity of Lp. Though Mip influences disease outcome, little is known about the metabolic consequences of altered Mip activity during infections. Here, we established a metabolic workflow and applied mass spectrometry approaches to decipher how Mip activity influences metabolism and pathogenicity. Impaired Mip activity in genetically engineered Lp strains decreases intracellular replication in cellular infection assays, confirming the contribution of Mip for Lp pathogenicity. We observed that genetic and chemical alteration of Mip using the PPIase inhibitors rapamycin and FK506 induces metabolic reprogramming in Lp, specifically branched-chain amino acid (BCAA) metabolism. Rapamycin also inhibits PPIase activity of mammalian FK506 binding proteins, and we observed that rapamycin induces a distinct metabolic signature in human macrophages compared to bacteria, suggesting potential involvement of Mip in normal bacteria and in infection. Our metabolic studies link Mip to alterations in BCAA metabolism and may help to decipher novel disease mechanisms associated with LD.
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Affiliation(s)
- Fabian Nikolka
- Department of Bioinformatics and Biochemistry, Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Mustafa Safa Karagöz
- Institut für Mikrobiologie, Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Mohamed Zakaria Nassef
- Department of Bioinformatics and Biochemistry, Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Karsten Hiller
- Department of Bioinformatics and Biochemistry, Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Thekla Cordes
- Department of Bioinformatics and Biochemistry, Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, 38106 Braunschweig, Germany
- Research Group Cellular Metabolism in Infection, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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232
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Jeong MH, Urquhart G, Lewis C, Chi Z, Jewell JL. Inhibition of phosphodiesterase 4D suppresses mTORC1 signaling and pancreatic cancer growth. JCI Insight 2023; 8:e158098. [PMID: 37427586 PMCID: PMC10371348 DOI: 10.1172/jci.insight.158098] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/23/2023] [Indexed: 07/11/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) senses multiple upstream stimuli to orchestrate anabolic and catabolic events that regulate cell growth and metabolism. Hyperactivation of mTORC1 signaling is observed in multiple human diseases; thus, pathways that suppress mTORC1 signaling may help to identify new therapeutic targets. Here, we report that phosphodiesterase 4D (PDE4D) promotes pancreatic cancer tumor growth by increasing mTORC1 signaling. GPCRs paired to Gαs proteins activate adenylyl cyclase, which in turn elevates levels of 3',5'-cyclic adenosine monophosphate (cAMP), whereas PDEs catalyze the hydrolysis of cAMP to 5'-AMP. PDE4D forms a complex with mTORC1 and is required for mTORC1 lysosomal localization and activation. Inhibition of PDE4D and the elevation of cAMP levels block mTORC1 signaling via Raptor phosphorylation. Moreover, pancreatic cancer exhibits an upregulation of PDE4D expression, and high PDE4D levels predict the poor overall survival of patients with pancreatic cancer. Importantly, FDA-approved PDE4 inhibitors repress pancreatic cancer cell tumor growth in vivo by suppressing mTORC1 signaling. Our results identify PDE4D as an important activator of mTORC1 and suggest that targeting PDE4 with FDA-approved inhibitors may be beneficial for the treatment of human diseases with hyperactivated mTORC1 signaling.
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Affiliation(s)
- Mi-Hyeon Jeong
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
| | - Greg Urquhart
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
| | | | - Zhikai Chi
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jenna L. Jewell
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
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233
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Pal DS, Lin Y, Zhan H, Banerjee T, Kuhn J, Providence S, Devreotes PN. Optogenetic modulation of guanine nucleotide exchange factors of Ras superfamily proteins directly controls cell shape and movement. Front Cell Dev Biol 2023; 11:1195806. [PMID: 37492221 PMCID: PMC10363612 DOI: 10.3389/fcell.2023.1195806] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/27/2023] [Indexed: 07/27/2023] Open
Abstract
In this article, we provide detailed protocols on using optogenetic dimerizers to acutely perturb activities of guanine nucleotide exchange factors (GEFs) specific to Ras, Rac or Rho small GTPases of the migratory networks in various mammalian and amoeba cell lines. These GEFs are crucial components of signal transduction networks which link upstream G-protein coupled receptors to downstream cytoskeletal components and help cells migrate through their dynamic microenvironment. Conventional approaches to perturb and examine these signaling and cytoskeletal networks, such as gene knockout or overexpression, are protracted which allows networks to readjust through gene expression changes. Moreover, these tools lack spatial resolution to probe the effects of local network activations. To overcome these challenges, blue light-inducible cryptochrome- and LOV domain-based dimerization systems have been recently developed to control signaling or cytoskeletal events in a spatiotemporally precise manner. We illustrate that, within minutes of global membrane recruitment of full-length GEFs or their catalytic domains only, widespread increases or decreases in F-actin rich protrusions and cell size occur, depending on the particular node in the networks targeted. Additionally, we demonstrate localized GEF recruitment as a robust assay system to study local network activation-driven changes in polarity and directed migration. Altogether, these optical tools confirmed GEFs of Ras superfamily GTPases as regulators of cell shape, actin dynamics, and polarity. Furthermore, this optogenetic toolbox may be exploited in perturbing complex signaling interactions in varied physiological contexts including mammalian embryogenesis.
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Affiliation(s)
- Dhiman Sankar Pal
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Yiyan Lin
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Huiwang Zhan
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Tatsat Banerjee
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Jonathan Kuhn
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Stephenie Providence
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
- Ingenuity Research Program, Baltimore Polytechnic Institute, Baltimore, MD, United States
| | - Peter N. Devreotes
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
- Department of Biological Chemistry, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
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234
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Zhong D, Wang R, Zhang H, Wang M, Zhang X, Chen H. Induction of lysosomal exocytosis and biogenesis via TRPML1 activation for the treatment of uranium-induced nephrotoxicity. Nat Commun 2023; 14:3997. [PMID: 37414766 PMCID: PMC10326073 DOI: 10.1038/s41467-023-39716-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 06/27/2023] [Indexed: 07/08/2023] Open
Abstract
Uranium (U) is a well-known nephrotoxicant which forms precipitates in the lysosomes of renal proximal tubular epithelial cells (PTECs) after U-exposure at a cytotoxic dose. However, the roles of lysosomes in U decorporation and detoxification remain to be elucidated. Mucolipin transient receptor potential channel 1 (TRPML1) is a major lysosomal Ca2+ channel regulating lysosomal exocytosis. We herein demonstrate that the delayed administration of the specific TRPML1 agonist ML-SA1 significantly decreases U accumulation in the kidney, mitigates renal proximal tubular injury, increases apical exocytosis of lysosomes and reduces lysosomal membrane permeabilization (LMP) in renal PTECs of male mice with single-dose U poisoning or multiple-dose U exposure. Mechanistic studies reveal that ML-SA1 stimulates intracellular U removal and reduces U-induced LMP and cell death through activating the positive TRPML1-TFEB feedback loop and consequent lysosomal exocytosis and biogenesis in U-loaded PTECs in vitro. Together, our studies demonstrate that TRPML1 activation is an attractive therapeutic strategy for the treatment of U-induced nephrotoxicity.
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Affiliation(s)
- Dengqin Zhong
- Institute of Radiation Medicine, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Ruiyun Wang
- Institute of Radiation Medicine, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Hongjing Zhang
- Institute of Radiation Medicine, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Mengmeng Wang
- Institute of Radiation Medicine, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Xuxia Zhang
- Institute of Radiation Medicine, Shanghai Medical College, Fudan University, Shanghai, PR China
| | - Honghong Chen
- Institute of Radiation Medicine, Shanghai Medical College, Fudan University, Shanghai, PR China.
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235
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Reijnders MRF, Seibt A, Brugger M, Lamers IJC, Ott T, Klaas O, Horváth J, Rose AMS, Craghill IM, Brunet T, Graf E, Mayerhanser K, Hellebrekers D, Pauck D, Neuen-Jacob E, Rodenburg RJT, Wieczorek D, Klee D, Mayatepek E, Driessen G, Bindermann R, Averdunk L, Lohmeier K, Sinnema M, Stegmann APA, Roepman R, Poulter JA, Distelmaier F. De novo missense variants in RRAGC lead to a fatal mTORopathy of early childhood. Genet Med 2023; 25:100838. [PMID: 37057673 DOI: 10.1016/j.gim.2023.100838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/29/2023] [Accepted: 04/03/2023] [Indexed: 04/15/2023] Open
Abstract
PURPOSE Mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) regulates cell growth in response to nutritional status. Central to the mTORC1 function is the Rag-GTPase heterodimer. One component of the Rag heterodimer is RagC (Ras-related GTP-binding protein C), which is encoded by the RRAGC gene. METHODS Genetic testing via trio exome sequencing was applied to identify the underlying disease cause in 3 infants with dilated cardiomyopathy, hepatopathy, and brain abnormalities, including pachygyria, polymicrogyria, and septo-optic dysplasia. Studies in patient-derived skin fibroblasts and in a HEK293 cell model were performed to investigate the cellular consequences. RESULTS We identified 3 de novo missense variants in RRAGC (NM_022157.4: c.269C>A, p.(Thr90Asn), c.353C>T, p.(Pro118Leu), and c.343T>C, p.(Trp115Arg)), which were previously reported as occurring somatically in follicular lymphoma. Studies of patient-derived fibroblasts carrying the p.(Thr90Asn) variant revealed increased cell size, as well as dysregulation of mTOR-related p70S6K (ribosomal protein S6 kinase 1) and transcription factor EB signaling. Moreover, subcellular localization of mTOR was decoupled from metabolic state. We confirmed the key findings for all RRAGC variants described in this study in a HEK293 cell model. CONCLUSION The above results are in line with a constitutive overactivation of the mTORC1 pathway. Our study establishes de novo missense variants in RRAGC as cause of an early-onset mTORopathy with unfavorable prognosis.
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Affiliation(s)
- Margot R F Reijnders
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Annette Seibt
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Melanie Brugger
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Ideke J C Lamers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Torsten Ott
- University Children's Hospital, University Hospital Muenster, Münster, Germany
| | - Oliver Klaas
- Institute for Human Genetics, University Hospital Muenster, Muenster, Germany
| | - Judit Horváth
- Institute for Human Genetics, University Hospital Muenster, Muenster, Germany
| | - Ailsa M S Rose
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | - Isabel M Craghill
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | - Theresa Brunet
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany; Department of Paediatric Neurology and Developmental Medicine, Hauner Children's Hospital, Ludwig Maximilian University of Munich, Munich, Germany
| | - Elisabeth Graf
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Katharina Mayerhanser
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Debby Hellebrekers
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - David Pauck
- Institute of Neuropathology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Eva Neuen-Jacob
- Institute of Neuropathology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Richard J T Rodenburg
- Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dagmar Wieczorek
- Institute of Human Genetics, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Dirk Klee
- Department of Diagnostic and Interventional Radiology, University Hospital, Düsseldorf, Germany
| | - Ertan Mayatepek
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Gertjan Driessen
- Department of Paediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Robert Bindermann
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Luisa Averdunk
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Klaus Lohmeier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Margje Sinnema
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Alexander P A Stegmann
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - James A Poulter
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany.
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236
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Doxsey DD, Tettoni SD, Egri SB, Shen K. Redundant electrostatic interactions between GATOR1 and the Rag GTPase heterodimer drive efficient amino acid sensing in human cells. J Biol Chem 2023; 299:104880. [PMID: 37269949 PMCID: PMC10316081 DOI: 10.1016/j.jbc.2023.104880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/05/2023] Open
Abstract
Cells need to coordinate nutrient availability with their growth and proliferation. In eukaryotic cells, this coordination is mediated by the mechanistic target of the rapamycin complex 1 (mTORC1) pathway. mTORC1 activation is regulated by two GTPase units, the Rag GTPase heterodimer and the Rheb GTPase. The RagA-RagC heterodimer controls the subcellular localization of mTORC1, and its nucleotide loading states are strictly controlled by upstream regulators including amino acid sensors. A critical negative regulator of the Rag GTPase heterodimer is GATOR1. In the absence of amino acids, GATOR1 stimulates GTP hydrolysis by the RagA subunit to turn off mTORC1 signaling. Despite the enzymatic specificity of GATOR1 to RagA, a recent cryo-EM structural model of the human GATOR1-Rag-Ragulator complex reveals an unexpected interface between Depdc5, a subunit of GATOR1, and RagC. Currently, there is no functional characterization of this interface, nor do we know its biological relevance. Here, combining structure-function analysis, enzymatic kinetic measurements, and cell-based signaling assays, we identified a critical electrostatic interaction between Depdc5 and RagC. This interaction is mediated by the positively charged Arg-1407 residue on Depdc5 and a patch of negatively charged residues on the lateral side of RagC. Abrogating this interaction impairs the GAP activity of GATOR1 and cellular response to amino acid withdrawal. Our results reveal how GATOR1 coordinates the nucleotide loading states of the Rag GTPase heterodimer, and thus precisely controls cellular behavior in the absence of amino acids.
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Affiliation(s)
- Dylan D Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Steven D Tettoni
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Shawn B Egri
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA; Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA.
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237
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Martinez-Lopez N, Mattar P, Toledo M, Bains H, Kalyani M, Aoun ML, Sharma M, McIntire LBJ, Gunther-Cummins L, Macaluso FP, Aguilan JT, Sidoli S, Bourdenx M, Singh R. mTORC2-NDRG1-CDC42 axis couples fasting to mitochondrial fission. Nat Cell Biol 2023; 25:989-1003. [PMID: 37386153 PMCID: PMC10344787 DOI: 10.1038/s41556-023-01163-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 05/04/2023] [Indexed: 07/01/2023]
Abstract
Fasting triggers diverse physiological adaptations including increases in circulating fatty acids and mitochondrial respiration to facilitate organismal survival. The mechanisms driving mitochondrial adaptations and respiratory sufficiency during fasting remain incompletely understood. Here we show that fasting or lipid availability stimulates mTORC2 activity. Activation of mTORC2 and phosphorylation of its downstream target NDRG1 at serine 336 sustains mitochondrial fission and respiratory sufficiency. Time-lapse imaging shows that NDRG1, but not the phosphorylation-deficient NDRG1Ser336Ala mutant, engages with mitochondria to facilitate fission in control cells, as well as in those lacking DRP1. Using proteomics, a small interfering RNA screen, and epistasis experiments, we show that mTORC2-phosphorylated NDRG1 cooperates with small GTPase CDC42 and effectors and regulators of CDC42 to orchestrate fission. Accordingly, RictorKO, NDRG1Ser336Ala mutants and Cdc42-deficient cells each display mitochondrial phenotypes reminiscent of fission failure. During nutrient surplus, mTOR complexes perform anabolic functions; however, paradoxical reactivation of mTORC2 during fasting unexpectedly drives mitochondrial fission and respiration.
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Affiliation(s)
- Nuria Martinez-Lopez
- Department of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, Los Angeles, CA, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
- Liver Basic Research Center at University of California Los Angeles, Los Angeles, CA, USA
| | - Pamela Mattar
- Department of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Miriam Toledo
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
- Neuronal Control of Metabolism Laboratory, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Henrietta Bains
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Manu Kalyani
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Marie Louise Aoun
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Mridul Sharma
- Department of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | | | - Leslie Gunther-Cummins
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Frank P Macaluso
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jennifer T Aguilan
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Simone Sidoli
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Mathieu Bourdenx
- UK Dementia Research Institute, London, UK
- UCL Queen Square Institute of Neurology, London, UK
| | - Rajat Singh
- Department of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
- Vatche and Tamar Manoukian Division of Digestive Diseases, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA.
- Liver Basic Research Center at University of California Los Angeles, Los Angeles, CA, USA.
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, USA.
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238
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Wei S, Nguyen TT, Zhang Y, Ryu D, Gariani K. Sarcopenic obesity: epidemiology, pathophysiology, cardiovascular disease, mortality, and management. Front Endocrinol (Lausanne) 2023; 14:1185221. [PMID: 37455897 PMCID: PMC10344359 DOI: 10.3389/fendo.2023.1185221] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023] Open
Abstract
Sarcopenic obesity is defined as the coexistence of sarcopenia and obesity in the same individual, characterized by of the co-presence of body fat accumulation and muscle loss. This condition is currently a major concern as it is associated with frailty and disabilities such as cardiovascular disease, fractures, dementia, cancer, and increased all-cause mortality. Particularly, older individuals remain at risk of sarcopenic obesity. Progress at several levels is needed to improve the global prognostic outlook for this condition, including the elaboration and implementation of a more uniform definition that may favor the identification and specification of prevalence by age group. Furthermore, improvements in the understanding of the pathogenesis of sarcopenic obesity may lead to the development of more specific therapeutic interventions to improve prognosis. We reviewed the knowledge on sarcopenic obesity and its associations with cardiovascular diseases and mortality.
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Affiliation(s)
- Shibo Wei
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Thanh T. Nguyen
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Yan Zhang
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Dongryeol Ryu
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Karim Gariani
- Division of Endocrinology, Diabetes, Nutrition and Therapeutic Patient Education, Department of Medical Specialties, Geneva University Hospitals, Geneva, Switzerland
- Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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239
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Pan Z, Zhang H, Dokudovskaya S. The Role of mTORC1 Pathway and Autophagy in Resistance to Platinum-Based Chemotherapeutics. Int J Mol Sci 2023; 24:10651. [PMID: 37445831 DOI: 10.3390/ijms241310651] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
Cisplatin (cis-diamminedichloroplatinum I) is a platinum-based drug, the mainstay of anticancer treatment for numerous solid tumors. Since its approval by the FDA in 1978, the drug has continued to be used for the treatment of half of epithelial cancers. However, resistance to cisplatin represents a major obstacle during anticancer therapy. Here, we review recent findings on how the mTORC1 pathway and autophagy can influence cisplatin sensitivity and resistance and how these data can be applicable for the development of new therapeutic strategies.
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Affiliation(s)
- Zhenrui Pan
- CNRS UMR9018, Institut Gustave Roussy, Université Paris-Saclay, 94805 Villejuif, France
| | - Hanxiao Zhang
- CNRS UMR9018, Institut Gustave Roussy, Université Paris-Saclay, 94805 Villejuif, France
| | - Svetlana Dokudovskaya
- CNRS UMR9018, Institut Gustave Roussy, Université Paris-Saclay, 94805 Villejuif, France
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Uehara K, Santoleri D, Whitlock AEG, Titchenell PM. Insulin Regulation of Hepatic Lipid Homeostasis. Compr Physiol 2023; 13:4785-4809. [PMID: 37358513 PMCID: PMC10760932 DOI: 10.1002/cphy.c220015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
The incidence of obesity, insulin resistance, and type II diabetes (T2DM) continues to rise worldwide. The liver is a central insulin-responsive metabolic organ that governs whole-body metabolic homeostasis. Therefore, defining the mechanisms underlying insulin action in the liver is essential to our understanding of the pathogenesis of insulin resistance. During periods of fasting, the liver catabolizes fatty acids and stored glycogen to meet the metabolic demands of the body. In postprandial conditions, insulin signals to the liver to store excess nutrients into triglycerides, cholesterol, and glycogen. In insulin-resistant states, such as T2DM, hepatic insulin signaling continues to promote lipid synthesis but fails to suppress glucose production, leading to hypertriglyceridemia and hyperglycemia. Insulin resistance is associated with the development of metabolic disorders such as cardiovascular and kidney disease, atherosclerosis, stroke, and cancer. Of note, nonalcoholic fatty liver disease (NAFLD), a spectrum of diseases encompassing fatty liver, inflammation, fibrosis, and cirrhosis, is linked to abnormalities in insulin-mediated lipid metabolism. Therefore, understanding the role of insulin signaling under normal and pathologic states may provide insights into preventative and therapeutic opportunities for the treatment of metabolic diseases. Here, we provide a review of the field of hepatic insulin signaling and lipid regulation, including providing historical context, detailed molecular mechanisms, and address gaps in our understanding of hepatic lipid regulation and the derangements under insulin-resistant conditions. © 2023 American Physiological Society. Compr Physiol 13:4785-4809, 2023.
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Affiliation(s)
- Kahealani Uehara
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Dominic Santoleri
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anna E. Garcia Whitlock
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul M. Titchenell
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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241
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Gao G, Zhang K, Huang P, Zhao X, Li Q, Xie Y, Yin C, Li J, Wang Z, Zhong H, Xue J, Chen Z, Wu X, Wang Q. Identification of SNPs Associated with Goose Meat Quality Traits Using a Genome-Wide Association Study Approach. Animals (Basel) 2023; 13:2089. [PMID: 37443887 DOI: 10.3390/ani13132089] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/19/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
(1) Background: Goose meat is highly valued for its economic significance and vast market potential due to its desirable qualities, including a rich nutritional profile, tender texture, relatively low-fat content, and high levels of beneficial unsaturated fatty acids. However, there is an urgent need to improve goose breeding by identifying molecular markers associated with meat quality. (2) Methods: We evaluated meat quality traits, such as meat color, shear force (SF), cooking loss rate (CLR), and crude fat content (CFC), in a population of 215 male Sichuan white geese at 70 days of age. A GWAS was performed to identify potential molecular markers associated with goose meat quality. Furthermore, the selected SNPs linked to meat quality traits were genotyped using the MALDI-TOP MS method. (3) Results: A dataset of 2601.19 Gb of WGS data was obtained from 215 individuals, with an average sequencing depth of 10.89×. The GWAS revealed the identification of 43 potentially significant SNP markers associated with meat quality traits in the Sichuan white goose population. Additionally, 28 genes were identified as important candidate genes for meat quality. The gene enrichment analysis indicated a substantial enrichment of genes within a 1Mb vicinity of SNPs in both the protein digestion and absorption pathway and the Glycerolipid metabolism pathway. (4) Conclusion: This study provides valuable insights into the genetic and molecular mechanisms underlying goose meat quality traits, offering crucial references for molecular breeding in this field.
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Affiliation(s)
- Guangliang Gao
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Keshan Zhang
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Ping Huang
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
| | - Xianzhi Zhao
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Qin Li
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Youhui Xie
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Chunhui Yin
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Jing Li
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Zhen Wang
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Hang Zhong
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Jiajia Xue
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Zhuping Chen
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
| | - Xianwen Wu
- Department of Laboratory Animal Sciences, Peking University Health Sciences Center, Beijing 100191, China
| | - Qigui Wang
- Chongqing Academy of Animal Science, Rongchang District, Chongqing 402460, China
- Chongqing Engineering Research Center of Goose Genetic Improvement, Rongchang District, Chongqing 402460, China
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Zhu Y, Wang S, Niu P, Chen H, Zhou J, Jiang L, Li D, Shi D. Raptor couples mTORC1 and ERK1/2 inhibition by cardamonin with oxidative stress induction in ovarian cancer cells. PeerJ 2023; 11:e15498. [PMID: 37304865 PMCID: PMC10257395 DOI: 10.7717/peerj.15498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 05/12/2023] [Indexed: 06/13/2023] Open
Abstract
Background A balance on nutrient supply and redox homeostasis is required for cell survival, and increased antioxidant capacity of cancer cells may lead to chemotherapy failure. Objective To investigate the mechanism of anti-proliferation of cardamonin by inducing oxidative stress in ovarian cancer cells. Methods After 24 h of drug treatment, CCK8 kit and wound healing test were used to detect cell viability and migration ability, respectively, and the ROS levels were detected by flow cytometry. The differential protein expression after cardamonin administration was analyzed by proteomics, and the protein level was detected by Western blotting. Results Cardamonin inhibited the cell growth, which was related to ROS accumulation. Proteomic analysis suggested that MAPK pathway might be involved in cardamonin-induced oxidative stress. Western blotting showed that cardamonin decreased Raptor expression and the activity of mTORC1 and ERK1/2. Same results were observed in Raptor KO cells. Notably, in Raptor KO cells, the effect of cardamonin was weakened. Conclusion Raptor mediated the function of cardamonin on cellular redox homeostasis and cell proliferation through mTORC1 and ERK1/2 pathways.
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Li W, Kou J, Zhang Z, Li H, Li L, Du W. Cellular redox homeostasis maintained by malic enzyme 2 is essential for MYC-driven T cell lymphomagenesis. Proc Natl Acad Sci U S A 2023; 120:e2217869120. [PMID: 37253016 PMCID: PMC10266009 DOI: 10.1073/pnas.2217869120] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/28/2023] [Indexed: 06/01/2023] Open
Abstract
T cell lymphomas (TCLs) are a group of rare and heterogeneous tumors. Although proto-oncogene MYC has an important role in driving T cell lymphomagenesis, whether MYC carries out this function remains poorly understood. Here, we show that malic enzyme 2 (ME2), one of the NADPH-producing enzymes associated with glutamine metabolism, is essential for MYC-driven T cell lymphomagenesis. We establish a CD4-Cre; Myc flox/+transgenic mouse mode, and approximately 90% of these mice develop TCL. Interestingly, knockout of Me2 in Myc transgenic mice almost completely suppresses T cell lymphomagenesis. Mechanistically, by transcriptionally up-regulating ME2, MYC maintains redox homeostasis, thereby increasing its tumorigenicity. Reciprocally, ME2 promotes MYC translation by stimulating mTORC1 activity through adjusting glutamine metabolism. Treatment with rapamycin, an inhibitor of mTORC1, blocks the development of TCL both in vitro and in vivo. Therefore, our findings identify an important role for ME2 in MYC-driven T cell lymphomagenesis and reveal that MYC-ME2 circuit may be an effective target for TCL therapy.
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Affiliation(s)
- Wei Li
- State Key Laboratory of Medical Molecular Biology, Haihe Laboratory of Cell Ecosystem, Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College100005, Beijing, China
| | - Junjie Kou
- State Key Laboratory of Medical Molecular Biology, Haihe Laboratory of Cell Ecosystem, Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College100005, Beijing, China
| | - Zhenxi Zhang
- State Key Laboratory of Medical Molecular Biology, Haihe Laboratory of Cell Ecosystem, Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College100005, Beijing, China
| | - Haoyue Li
- State Key Laboratory of Medical Molecular Biology, Haihe Laboratory of Cell Ecosystem, Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College100005, Beijing, China
| | - Li Li
- State Key Laboratory of Medical Molecular Biology, Haihe Laboratory of Cell Ecosystem, Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College100005, Beijing, China
| | - Wenjing Du
- State Key Laboratory of Medical Molecular Biology, Haihe Laboratory of Cell Ecosystem, Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College100005, Beijing, China
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244
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Saygili Demir C, Sabine A, Gong M, Dormond O, Petrova TV. Mechanosensitive mTORC1 signaling maintains lymphatic valves. J Cell Biol 2023; 222:e202207049. [PMID: 37036444 PMCID: PMC10097975 DOI: 10.1083/jcb.202207049] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 01/26/2023] [Accepted: 03/23/2023] [Indexed: 04/11/2023] Open
Abstract
Homeostatic maintenance and repair of lymphatic vessels are essential for health. We investigated the dynamics and the molecular mechanisms of lymphatic endothelial cell (LEC) renewal in adult mesenteric quiescent lymphatic vasculature using label-retention, lineage tracing, and cell ablation strategies. Unlike during development, adult LEC turnover and proliferation was confined to the valve regions of collecting vessels, with valve cells displaying the shortest lifespan. Proliferating valve sinus LECs were the main source for maintenance and repair of lymphatic valves. We identified mechanistic target of rapamycin complex 1 (mTORC1) as a mechanoresponsive pathway activated by fluid shear stress in LECs. Depending on the shear stress level, mTORC1 activity drives division of valve cells or dictates their mechanic resilience through increased protein synthesis. Overactivation of lymphatic mTORC1 in vivo promoted supernumerary valve formation. Our work provides insights into the molecular mechanisms of maintenance of healthy lymphatic vascular system.
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Affiliation(s)
- Cansaran Saygili Demir
- Department of Oncology, Lausanne University Hospital-University of Lausanne, Lausanne, Switzerland
- Ludwig Institute for Cancer Research Lausanne, Lausanne, Switzerland
| | - Amélie Sabine
- Department of Oncology, Lausanne University Hospital-University of Lausanne, Lausanne, Switzerland
- Ludwig Institute for Cancer Research Lausanne, Lausanne, Switzerland
| | - Muyun Gong
- Department of Oncology, Lausanne University Hospital-University of Lausanne, Lausanne, Switzerland
- Ludwig Institute for Cancer Research Lausanne, Lausanne, Switzerland
| | - Olivier Dormond
- Department of Visceral Surgery, Lausanne University Hospital, Lausanne, Switzerland
| | - Tatiana V. Petrova
- Department of Oncology, Lausanne University Hospital-University of Lausanne, Lausanne, Switzerland
- Ludwig Institute for Cancer Research Lausanne, Lausanne, Switzerland
- Swiss Institute for Experimental Cancer Research, École polytechnique fédérale de Lausanne, Lausanne, Switzerland
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245
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Xie Y, Lei X, Zhao G, Guo R, Cui N. mTOR in programmed cell death and its therapeutic implications. Cytokine Growth Factor Rev 2023; 71-72:66-81. [PMID: 37380596 DOI: 10.1016/j.cytogfr.2023.06.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/12/2023] [Accepted: 06/19/2023] [Indexed: 06/30/2023]
Abstract
Mechanistic target of rapamycin (mTOR), a highly conserved serine/threonine kinase, is involved in cellular metabolism, protein synthesis, and cell death. Programmed cell death (PCD) assists in eliminating aging, damaged, or neoplastic cells, and is indispensable for sustaining normal growth, fighting pathogenic microorganisms, and maintaining body homeostasis. mTOR has crucial functions in the intricate signaling pathway network of multiple forms of PCD. mTOR can inhibit autophagy, which is part of PCD regulation. Cell survival is affected by mTOR through autophagy to control reactive oxygen species production and the degradation of pertinent proteins. Additionally, mTOR can regulate PCD in an autophagy-independent manner by affecting the expression levels of related genes and phosphorylating proteins. Therefore, mTOR acts through both autophagy-dependent and -independent pathways to regulate PCD. It is conceivable that mTOR exerts bidirectional regulation of PCD, such as ferroptosis, according to the complexity of signaling pathway networks, but the underlying mechanisms have not been fully explained. This review summarizes the recent advances in understanding mTOR-mediated regulatory mechanisms in PCD. Rigorous investigations into PCD-related signaling pathways have provided prospective therapeutic targets that may be clinically beneficial for treating various diseases.
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Affiliation(s)
- Yawen Xie
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Xianli Lei
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Guoyu Zhao
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Ran Guo
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Na Cui
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
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246
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Sung Y, Yu YC, Han JM. Nutrient sensors and their crosstalk. Exp Mol Med 2023; 55:1076-1089. [PMID: 37258576 PMCID: PMC10318010 DOI: 10.1038/s12276-023-01006-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/22/2023] [Accepted: 03/13/2023] [Indexed: 06/02/2023] Open
Abstract
The macronutrients glucose, lipids, and amino acids are the major components that maintain life. The ability of cells to sense and respond to fluctuations in these nutrients is a crucial feature for survival. Nutrient-sensing pathways are thus developed to govern cellular energy and metabolic homeostasis and regulate diverse biological processes. Accordingly, perturbations in these sensing pathways are associated with a wide variety of pathologies, especially metabolic diseases. Molecular sensors are the core within these sensing pathways and have a certain degree of specificity and affinity to sense the intracellular fluctuation of each nutrient either by directly binding to that nutrient or indirectly binding to its surrogate molecules. Once the changes in nutrient levels are detected, sensors trigger signaling cascades to fine-tune cellular processes for energy and metabolic homeostasis, for example, by controlling uptake, de novo synthesis or catabolism of that nutrient. In this review, we summarize the major discoveries on nutrient-sensing pathways and explain how those sensors associated with each pathway respond to intracellular nutrient availability and how these mechanisms control metabolic processes. Later, we further discuss the crosstalk between these sensing pathways for each nutrient, which are intertwined to regulate overall intracellular nutrient/metabolic homeostasis.
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Affiliation(s)
- Yulseung Sung
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon, 21983, South Korea
| | - Ya Chun Yu
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon, 21983, South Korea
| | - Jung Min Han
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon, 21983, South Korea.
- Department of Integrated OMICS for Biomedical Science, Yonsei University, Seoul, 03722, South Korea.
- POSTECH Biotech Center, Pohang University of Science and Technology, Pohang, 37673, South Korea.
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247
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Mannick JB, Lamming DW. Targeting the biology of aging with mTOR inhibitors. NATURE AGING 2023; 3:642-660. [PMID: 37142830 PMCID: PMC10330278 DOI: 10.1038/s43587-023-00416-y] [Citation(s) in RCA: 139] [Impact Index Per Article: 69.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 04/07/2023] [Indexed: 05/06/2023]
Abstract
Inhibition of the protein kinase mechanistic target of rapamycin (mTOR) with the Food and Drug Administration (FDA)-approved therapeutic rapamycin promotes health and longevity in diverse model organisms. More recently, specific inhibition of mTORC1 to treat aging-related conditions has become the goal of basic and translational scientists, clinicians and biotechnology companies. Here, we review the effects of rapamycin on the longevity and survival of both wild-type mice and mouse models of human diseases. We discuss recent clinical trials that have explored whether existing mTOR inhibitors can safely prevent, delay or treat multiple diseases of aging. Finally, we discuss how new molecules may provide routes to the safer and more selective inhibition of mTOR complex 1 (mTORC1) in the decade ahead. We conclude by discussing what work remains to be done and the questions that will need to be addressed to make mTOR inhibitors part of the standard of care for diseases of aging.
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Affiliation(s)
| | - Dudley W Lamming
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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248
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Li M, Wei X, Xiong J, Feng JW, Zhang CS, Lin SC. Hierarchical inhibition of mTORC1 by glucose starvation-triggered AXIN lysosomal translocation and by AMPK. LIFE METABOLISM 2023; 2:load005. [PMID: 39872013 PMCID: PMC11749110 DOI: 10.1093/lifemeta/load005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/20/2023] [Accepted: 02/20/2023] [Indexed: 01/29/2025]
Abstract
When glucose is replete, mammalian/mechanistic target of rapamycin complex 1 (mTORC1) is active and anchored to the lysosomal surface via the two GTPases, Ras-related GTPase (RAG) and Ras homolog enriched in brain (Rheb), which are regulated by Ragulator and tuberous sclerosis complex 2 (TSC2), respectively. When glucose is low, aldolase senses low fructose-1,6-bisphosphate level and promotes the translocation of AXIN-liver kinase B1 (LKB1) to the lysosomal surface, which leads to the activation of AMP-activated protein kinase (AMPK) and the inhibition of RAGs, sundering mTORC1 from the lysosome and causing its inactivation. AMPK can also inactivate mTORC1 by phosphorylating Raptor and TSC2. However, the hierarchy of AXIN- and AMPK-mediated inhibition of mTORC1 remains poorly defined. Here, we show that AXIN translocation does not require AMPK expression or activity. In glucose starvation conditions, knockout of AXIN extended the half-life of mTORC1 inhibition from 15 to 60 min, whereas knockout of AMPK only extended it to 30 min. RAGBGTP (constitutively active RAGB) almost entirely blocked the lysosomal dissociation and inhibition of mTORC1 under glucose starvation, but it did not inhibit AMPK, indicating that under these conditions, it is AXIN lysosomal translocation that inhibits mTORC1, and it does so via inhibition of RAGs. 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), a mimetic of AMP, which activates both cytosolic AMPK and lysosomal AMPK, fully inhibited mTORC1 even when it is stably anchored to the lysosome by RAGBGTP, whereas glucose starvation mildly inhibited such anchored mTORC1. Together, we demonstrate that the lysosomal translocation of AXIN plays a primary role in glucose starvation-triggered inhibition of mTORC1 by inhibiting RAGs, and that AMPK activity inhibits mTORC1 through phosphorylating Raptor and TSC2, especially under severe stress.
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Affiliation(s)
- Mengqi Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaoyan Wei
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Jinye Xiong
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Jin-Wei Feng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Chen-Song Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Sheng-Cai Lin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
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249
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Ishii Y, Yamaji T, Sekizuka T, Homma Y, Mori S, Takeuchi T, Kukimoto I. Folliculin Prevents Lysosomal Degradation of Human Papillomavirus To Support Infectious Cell Entry. J Virol 2023; 97:e0005623. [PMID: 37167561 PMCID: PMC10231244 DOI: 10.1128/jvi.00056-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/20/2023] [Indexed: 05/13/2023] Open
Abstract
Human papillomavirus (HPV) infects epithelial basal cells in the mucosa and either proliferates with the differentiation of the basal cells or persists in them. Multiple host factors are required to support the HPV life cycle; however, the molecular mechanisms involved in cell entry are not yet fully understood. In this study, we performed a genome-wide clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein 9 (Cas9) knockout (KO) screen in HeLa cells and identified folliculin (FLCN), a GTPase-activating protein for Rag GTPases, as an important host factor for HPV infection. The introduction of single guide RNAs for the FLCN gene into HeLa, HaCaT, and ectocervical Ect1 cells reduced infection by HPV18 pseudovirions (18PsVs) and 16PsVs. FLCN KO HeLa cells also exhibited strong resistance to infection with 18PsVs and 16PsVs; nevertheless, they remained highly susceptible to infections with vesicular stomatitis virus glycoprotein-pseudotyped lentivirus and adeno-associated virus. Immunofluorescence microscopy revealed that the numbers of virions binding to the cell surface were slightly increased in FLCN KO cells. However, virion internalization analysis showed that the internalized virions were rapidly degraded in FLCN KO cells. This degradation was blocked by treatment with the lysosome inhibitor bafilomycin A1. Furthermore, the virion degradation phenotype was also observed in Ras-related GTP-binding protein C (RagC) KO cells. These results suggest that FLCN prevents the lysosomal degradation of incoming HPV virions by enhancing lysosomal RagC activity. IMPORTANCE Cell entry by human papillomavirus (HPV) involves a cellular retrograde transport pathway from the endosome to the trans-Golgi network/Golgi apparatus. However, the mechanism by which this viral trafficking is safeguarded is poorly understood. This is the first study showing that the GTPase-activating protein folliculin (FLCN) protects incoming HPV virions from lysosomal degradation and supports infectious cell entry by activating the Rag GTPases, presumably through the suppression of excessive lysosomal biosynthesis. These findings provide new insights into the effects of small GTPase activity regulation on HPV cell entry and enhance our understanding of the HPV degradation pathway.
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Affiliation(s)
- Yoshiyuki Ishii
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Toshiyuki Yamaji
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tsuyoshi Sekizuka
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yuta Homma
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Seiichiro Mori
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takamasa Takeuchi
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Iwao Kukimoto
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
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250
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Liu GY, Jouandin P, Bahng RE, Perrimon N, Sabatini DM. An evolutionary mechanism to assimilate new nutrient sensors into the mTORC1 pathway. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.541239. [PMID: 37292894 PMCID: PMC10245982 DOI: 10.1101/2023.05.25.541239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Animals must sense and respond to nutrient availability in their local niche. This task is coordinated in part by the mTOR complex 1 (mTORC1) pathway, which regulates growth and metabolism in response to nutrients1-5. In mammals, mTORC1 senses specific amino acids through specialized sensors that act through the upstream GATOR1/2 signaling hub6-8. To reconcile the conserved architecture of the mTORC1 pathway with the diversity of environments that animals can occupy, we hypothesized that the pathway might maintain plasticity by evolving distinct nutrient sensors in different metazoan phyla1,9,10. Whether such customization occurs-and how the mTORC1 pathway might capture new nutrient inputs-is not known. Here, we identify the Drosophila melanogaster protein Unmet expectations (Unmet, formerly CG11596) as a species-restricted nutrient sensor and trace its incorporation into the mTORC1 pathway. Upon methionine starvation, Unmet binds to the fly GATOR2 complex to inhibit dTORC1. S-adenosylmethionine (SAM), a proxy for methionine availability, directly relieves this inhibition. Unmet expression is elevated in the ovary, a methionine-sensitive niche11, and flies lacking Unmet fail to maintain the integrity of the female germline under methionine restriction. By monitoring the evolutionary history of the Unmet-GATOR2 interaction, we show that the GATOR2 complex evolved rapidly in Dipterans to recruit and repurpose an independent methyltransferase as a SAM sensor. Thus, the modular architecture of the mTORC1 pathway allows it to co-opt preexisting enzymes and expand its nutrient sensing capabilities, revealing a mechanism for conferring evolvability on an otherwise highly conserved system.
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Affiliation(s)
- Grace Y. Liu
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Department of Biology; 455 Main Street, Cambridge, Massachusetts 02142, USA
- Department of Biology, Massachusetts Institute of Technology; 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Koch Institute for Integrative Cancer Research and Massachusetts Institute of Technology, Department of Biology; 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Patrick Jouandin
- Department of Genetics, Blavatnik Institute, Harvard Medical School; Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School; Boston, MA 02115, USA
- Present address: Institut de Recherche en Cancérologie de Montpellier, Inserm U1194-UM-ICM; Campus Val d’Aurelle, F-34298 Montpellier Cedex 5, France
| | - Raymond E. Bahng
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Department of Biology; 455 Main Street, Cambridge, Massachusetts 02142, USA
- Department of Biology, Massachusetts Institute of Technology; 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Koch Institute for Integrative Cancer Research and Massachusetts Institute of Technology, Department of Biology; 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School; Boston, MA 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School; Boston, MA 02115, USA
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