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Ambra1 Alleviates Hypoxia/Reoxygenation Injury in H9C2 Cells by Regulating Autophagy and Reactive Oxygen Species. BIOMED RESEARCH INTERNATIONAL 2020; 2020:3062689. [PMID: 33083461 PMCID: PMC7563064 DOI: 10.1155/2020/3062689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/08/2020] [Accepted: 09/21/2020] [Indexed: 11/24/2022]
Abstract
Reperfusion therapy is the most important method for treating acute myocardial infarction. However, myocardial ischemia reperfusion injury (MIRI) can offset the benefit of reperfusion therapy and worsen the outcome. In both ischemia and reperfusion, autophagy remains problematic. Activating molecule in Beclin1-regulated autophagy (Ambra1) is an important protein in autophagy regulation, and its function in MIRI remains unclear. Thus, we used H9C2 cells to investigate the function of Ambra1 in MIRI and the underlying mechanisms involved. Hypoxia and reoxygenation of H9C2 cells were used to mimic MIRI in vitro. During hypoxia, autophagy flux was blocked, then recovered in reoxygenation. Ambra1 overexpression increased autophagy in the H9C2 cells, as the LC3B II/I ratio increased, and alleviated cellular necrosis and apoptosis during hypoxia and reoxygenation. This effect was counteracted by an autophagy inhibitor. Knocking down Ambra1 can block autophagy which P62 sediment/supernatant ratio increased while the ratio of LC3B II/I decreased, and worsen outcomes. Ambra1 enhances autophagy in H9C2 cells by improving the stability and activity of the ULK1 complex. Reactive oxygen species (ROS) are an important cause of MIRI. ROS were reduced when Ambra1 was overexpressed and increased when Ambra1 was knocked down, indicating that Ambra1 can protect against hypoxia and reoxygenation injury in H9C2 cells by promoting autophagy and reducing ROS.
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Masuhara K, Akatsuka H, Tokusanai M, Li C, Iida Y, Okada Y, Suzuki T, Ohtsuka M, Inoue I, Kimura M, Hosokawa H, Hozumi K, Sato T. AMBRA1 controls antigen-driven activation and proliferation of naïve T cells. Int Immunol 2020; 33:107-118. [PMID: 32909612 DOI: 10.1093/intimm/dxaa063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 09/07/2020] [Indexed: 11/12/2022] Open
Abstract
AMBRA1 is a member of the BECN1 (BECLIN1) complex protein, and it plays a role in autophagy, cell death, tumorigenesis, and proliferation. We recently reported that on TCR stimulation, AMBRA1 controlled both autophagy and the cell cycle with metabolic regulation. Accumulating evidence has shown that autophagy and metabolic control are pivotal for T cell activation, clonal expansion, and effector/memory cell fate decision. However, it is unknown whether AMBRA1 is involved in T cell function under physiological conditions. We found that T cells in Ambra1-conditional knockout (cKO) mice induced exacerbated graft versus host response when they were transplanted into allogeneic BALB/c mice. Furthermore, Ambra1-deficient T cells showed increased proliferation and cytotoxic capability towards specific antigens in response to in vivo stimulation using allogeneic spleen cells. This enhanced immune response mainly contributed to naïve T cell hyperactivity. The T cell hyperactivity observed in this study were similar to those in some metabolic factor-deficient mice, but not those in other pro-autophagic factor-deficient mice. Under the static condition, however, naïve T cells were reduced in Ambra1-cKO mice, as same as in pro-autophagic factor-deficient mice. Collectively, these results suggested that AMBRA1 was involved in regulating T cell-mediated immune responses through autophagy-dependent and -independent mechanisms.
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Affiliation(s)
- Kaori Masuhara
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Hisako Akatsuka
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Mizuki Tokusanai
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Chenyang Li
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Yumi Iida
- Support Center for Medical Research and Education, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Yoshinori Okada
- Support Center for Medical Research and Education, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Takahiro Suzuki
- Department of Ophthalmology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Masato Ohtsuka
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Ituro Inoue
- Division of Human Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Minoru Kimura
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Hiroyuki Hosokawa
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Katsuto Hozumi
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Takehito Sato
- Department of Immunology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
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The Role of microRNAs in Organismal and Skin Aging. Int J Mol Sci 2020; 21:ijms21155281. [PMID: 32722415 PMCID: PMC7432402 DOI: 10.3390/ijms21155281] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/11/2020] [Accepted: 07/23/2020] [Indexed: 12/12/2022] Open
Abstract
The aging process starts directly after birth and lasts for the entire lifespan; it manifests itself with a decline in an organism’s ability to adapt and is linked to the development of age-related diseases that eventually lead to premature death. This review aims to explore how microRNAs (miRNAs) are involved in skin functioning and aging. Recent evidence has suggested that miRNAs regulate all aspects of cutaneous biogenesis, functionality, and aging. It has been noted that some miRNAs were down-regulated in long-lived individuals, such as let-7, miR-17, and miR-34 (known as longevity-related miRNAs). They are conserved in humans and presumably promote lifespan prolongation; conversely, they are up-regulated in age-related diseases, like cancers. The analysis of the age-associated cutaneous miRNAs revealed the increased expression of miR-130, miR-138, and miR-181a/b in keratinocytes during replicative senescence. These miRNAs affected cell proliferation pathways via targeting the p63 and Sirtuin 1 mRNAs. Notably, miR-181a was also implicated in skin immunosenescence, represented by the Langerhans cells. Dermal fibroblasts also expressed increased the levels of the biomarkers of aging that affect telomere maintenance and all phases of the cellular life cycle, such as let-7, miR-23a-3p, 34a-5p, miR-125a, miR-181a-5p, and miR-221/222-3p. Among them, the miR-34 family, stimulated by ultraviolet B irradiation, deteriorates collagen in the extracellular matrix due to the activation of the matrix metalloproteinases and thereby potentiates wrinkle formation. In addition to the pro-aging effects of miRNAs, the plausible antiaging activity of miR-146a that antagonized the UVA-induced inhibition of proliferation and suppressed aging-related genes (e.g., p21WAF-1, p16, and p53) through targeting Smad4 has also been noticed. Nevertheless, the role of miRNAs in skin aging is still not fully elucidated and needs to be further discovered and explained.
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Morales I, Sanchez A, Puertas-Avendaño R, Rodriguez-Sabate C, Perez-Barreto A, Rodriguez M. Neuroglial transmitophagy and Parkinson's disease. Glia 2020; 68:2277-2299. [PMID: 32415886 DOI: 10.1002/glia.23839] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 12/28/2022]
Abstract
Mitophagy is essential for the health of dopaminergic neurons because mitochondrial damage is a keystone of Parkinson's disease. The aim of the present work was to study the degradation of mitochondria in the degenerating dopaminergic synapse. Adult Sprague-Dawley rats and YFP-Mito-DAn mice with fluorescent mitochondria in dopaminergic neurons were injected in the lateral ventricles with 6-hydroxydopamine, a toxic that inhibits the mitochondrial chain of dopaminergic neurons and blockades the axonal transport. Dopaminergic terminals closest to the lateral ventricle showed an axonal fragmentation and an accumulation of damaged mitochondria in 2-9 μ saccular structures (spheroids). Damaged mitochondria accumulated in spheroids initiated (showing high Pink1, parkin, ubiquitin, p-S65-Ubi, AMBRA1, and BCL2L13 immunoreactivity and developing autophagosomes) but did not complete (mitochondria were not polyubiquitinated, autophagosomes had no STX17, and no lysosomes were found in spheroids) the mitophagy process. Then, spheroids were penetrated by astrocytic processes and DAergic mitochondria were transferred to astrocytes where they were polyubiquitinated (UbiK63+) and linked to mature autophagosomes (STX17+) which became autophagolysosomes (Lamp1/Lamp2 which co-localized with LC3). Present data provide evidence that the mitophagy of degenerating dopaminergic terminals starts in the dopaminergic spheroids and finishes in the surrounding astrocytes (spheroid-mediated transmitophagy). The neuron-astrocyte transmitophagy could be critical for preventing the release of damaged mitochondria to the extracellular medium and the neuro-inflammatory activity which characterizes Parkinson's disease.
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Affiliation(s)
- Ingrid Morales
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain.,Center for Networked Biomedical Research in Neurodegenerative Diseases, Madrid, Spain
| | - Alberto Sanchez
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain
| | - Ricardo Puertas-Avendaño
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain
| | | | - Adrian Perez-Barreto
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain
| | - Manuel Rodriguez
- Laboratory of Neurobiology and Experimental Neurology, Department of Basic Medical Sciences, La Laguna University, La Laguna, Tenerife, Spain.,Center for Networked Biomedical Research in Neurodegenerative Diseases, Madrid, Spain
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55
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Meneghetti G, Skobo T, Chrisam M, Fontana CM, Facchinello N, Nazio F, Cecconi F, Bonaldo P, Dalla Valle L. Zebrafish ambra1a and ambra1b Silencing Affect Heart Development. Zebrafish 2020; 17:163-176. [PMID: 32320344 DOI: 10.1089/zeb.2020.1860] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In zebrafish, two paralogous genes, activating molecule in beclin-1 (BECN1)-regulated autophagy ambra1a and ambra1b, both required for the autophagic process and during development, encode the protein AMBRA1, a positive regulator of early steps of autophagosome formation. As transcripts for both genes are expressed during embryogenesis in the heart region, in this work, we investigated the effects of ambra1a and ambra1b knockdown on heart development by means of morpholino oligonucleotides (MOs). Silencing of the two proteins by MOs directed against the ATG translation initiation codon affects cardiac morphogenesis, resulting in a small, string-like heart with pericardial edema, whereas treatment with splice-blocking MOs does not lead to overt cardiac phenotypes, thus revealing the relevance of maternally supplied ambra1 transcripts for heart development. Co-injection of both ATG-MOs determines a more severe cardiac phenotype, with prominent pericardial edema. Whole-mount in situ hybridization (WMISH) for myosin light chain 7 (myl7), as well as ambra1 ATG-MO microinjection in zebrafish transgenic line expressing green fluorescent protein in the heart, revealed defects with the heart jogging process followed by imperfect cardiac looping. Moreover, WMISH of homeodomain transcription factor 2 isoform c (pitx2c) transcripts showed both bilateral and reversed pitx2c expression in morphants. The morphants' cardiac phenotypes were effectively rescued by co-injection of MOs with human AMBRA1 (hAMBRA1) messenger RNA (mRNA), pointing at the conservation of Ambra1 functions during evolution. Co-injections of ambra1 ATG-MOs with a hAMBRA1 mRNA mutated in the protein phosphatase 2a (PP2A) binding sites (hAMBRA1PXP) were not able to rescue the cardiac phenotypes, at the difference from wild-type hAMBRA1 mRNA, and treatment of zebrafish embryos with the specific PP2A inhibitor cantharidin resulted in similar developmental cardiac defects. These results suggest a critical role for AMBRA1 in vertebrate heart development, likely involving the binding site for the PP2A phosphatase.
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Affiliation(s)
| | - Tatjana Skobo
- Department of Biology and University of Padova, Padova, Italy
| | - Martina Chrisam
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | | | | | - Francesca Nazio
- Department of Pediatric Hemato-Oncology and Cell and Gene therapy, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Francesco Cecconi
- Unit of Cell Stress and Survival, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Paolo Bonaldo
- Department of Molecular Medicine, University of Padova, Padova, Italy
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56
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Allen EA, Baehrecke EH. Autophagy in animal development. Cell Death Differ 2020; 27:903-918. [PMID: 31988494 PMCID: PMC7206001 DOI: 10.1038/s41418-020-0497-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/19/2019] [Accepted: 01/07/2020] [Indexed: 01/13/2023] Open
Abstract
Macroautophagy (autophagy) delivers intracellular constituents to the lysosome to promote catabolism. During development in multiple organisms, autophagy mediates various cellular processes, including survival during starvation, programmed cell death, phagocytosis, organelle elimination, and miRNA regulation. Our current understanding of autophagy has been enhanced by developmental biology research during the last quarter of a century. Through experiments that focus on animal development, fundamental mechanisms that control autophagy and that contribute to disease were elucidated. Studies in embryos revealed specific autophagy molecules that mediate the removal of paternally derived mitochondria, and identified autophagy components that clear protein aggregates during development. Importantly, defects in mtDNA inheritance, or removal of paternal mtDNA via mitochondrial autophagy, can contribute to mitochondrial-associated disease. In addition, impairment of the clearance of protein aggregates by autophagy underlies neurodegenerative diseases. Experiments in multiple organisms also reveal conserved mechanisms of tissue remodeling that rely on the cooperation between autophagy and apoptosis to clear cell corpses, and defects in autophagy and apoptotic cell clearance can contribute to inflammation and autoimmunity. Here we provide an overview of key developmental processes that are mediated by autophagy in multiple animals.
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Affiliation(s)
- Elizabeth A Allen
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 423 Lazare Research Building, 364 Plantation St., Worcester, MA, 01655, USA
| | - Eric H Baehrecke
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 423 Lazare Research Building, 364 Plantation St., Worcester, MA, 01655, USA.
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57
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Joshi V, Upadhyay A, Prajapati VK, Mishra A. How autophagy can restore proteostasis defects in multiple diseases? Med Res Rev 2020; 40:1385-1439. [PMID: 32043639 DOI: 10.1002/med.21662] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 01/03/2020] [Accepted: 01/28/2020] [Indexed: 12/12/2022]
Abstract
Cellular evolution develops several conserved mechanisms by which cells can tolerate various difficult conditions and overall maintain homeostasis. Autophagy is a well-developed and evolutionarily conserved mechanism of catabolism, which endorses the degradation of foreign and endogenous materials via autolysosome. To decrease the burden of the ubiquitin-proteasome system (UPS), autophagy also promotes the selective degradation of proteins in a tightly regulated way to improve the physiological balance of cellular proteostasis that may get perturbed due to the accumulation of misfolded proteins. However, the diverse as well as selective clearance of unwanted materials and regulations of several cellular mechanisms via autophagy is still a critical mystery. Also, the failure of autophagy causes an increase in the accumulation of harmful protein aggregates that may lead to neurodegeneration. Therefore, it is necessary to address this multifactorial threat for in-depth research and develop more effective therapeutic strategies against lethal autophagy alterations. In this paper, we discuss the most relevant and recent reports on autophagy modulations and their impact on neurodegeneration and other complex disorders. We have summarized various pharmacological findings linked with the induction and suppression of autophagy mechanism and their promising preclinical and clinical applications to provide therapeutic solutions against neurodegeneration. The conclusion, key questions, and future prospectives sections summarize fundamental challenges and their possible feasible solutions linked with autophagy mechanism to potentially design an impactful therapeutic niche to treat neurodegenerative diseases and imperfect aging.
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Affiliation(s)
- Vibhuti Joshi
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Karwar, India
| | - Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Karwar, India
| | - Vijay K Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Karwar, India
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58
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AMBRA1, Autophagy, and the Extreme Male Brain Theory of Autism. AUTISM RESEARCH AND TREATMENT 2019; 2019:1968580. [PMID: 31687209 PMCID: PMC6811796 DOI: 10.1155/2019/1968580] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 09/17/2019] [Indexed: 11/29/2022]
Abstract
The extreme male brain theory of autism posits that its male bias is mediated by exaggeration of male-biased sex differences in the expression of autism-associated traits found in typical populations. The theory is supported by extensive phenotypic evidence, but no genes have yet been described with properties that fit its predictions. The autophagy-associated gene AMBRA1 represents one of the top genome-wide “hits” in recent GWAS studies of schizophrenia, shows sex-differential expression, and has been linked with autism risk and traits in humans and mice, especially or exclusively among females. We genotyped the AMBRA1 autism-risk SNP in a population of typical humans who were scored for the dimensional expression of autistic and schizotypal traits. Females, but not males, homozygous for the GG genotype showed a significant increase in score for the single trait, the Autism Quotient-Imagination subscale, that exhibits a strong, significant male bias in typical populations. As such, females with this genotype resembled males for this highly sexually dimorphic, autism-associated phenotype. These findings support the extreme male brain hypothesis and indicate that sex-specific genetic effects can mediate aspects of risk for autism.
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59
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The Emerging Roles of mTORC1 in Macromanaging Autophagy. Cancers (Basel) 2019; 11:cancers11101422. [PMID: 31554253 PMCID: PMC6826502 DOI: 10.3390/cancers11101422] [Citation(s) in RCA: 205] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 09/22/2019] [Accepted: 09/23/2019] [Indexed: 01/18/2023] Open
Abstract
Autophagy is a process of self-degradation that enables the cell to survive when faced with starvation or stressful conditions. The mechanistic target of rapamycin (mTOR), also known as the mammalian target of rapamycin, plays a critical role in maintaining a balance between cellular anabolism and catabolism. mTOR complex 1 (mTORC1) was unveiled as a master regulator of autophagy since inhibition of mTORC1 was required to initiate the autophagy process. Evidence has emerged in recent years to indicate that mTORC1 also directly regulates the subsequent steps of the autophagy process, including the nucleation, autophagosome elongation, autophagosome maturation and termination. By phosphorylating select protein targets of the autophagy core machinery and/or their regulators, mTORC1 can alter their functions, increase their proteasomal degradation or modulate their acetylation status, which is a key switch of the autophagy process. Moreover, it phosphorylates and alters the subcellular localization of transcription factors to suppress the expression of genes needed for autophagosome formation and lysosome biogenesis. The purpose of this review article is to critically analyze current literatures to provide an integrated view of how mTORC1 regulates various steps of the autophagy process.
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60
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Identification and characterization of WD40 superfamily genes in peach. Gene 2019; 710:291-306. [PMID: 31185283 DOI: 10.1016/j.gene.2019.06.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/25/2019] [Accepted: 06/05/2019] [Indexed: 01/16/2023]
Abstract
The WD40 transcription factor family is a superfamily found in all eukaryotes that plays important roles in regulating growth and development. To our knowledge, to date, WD40 superfamily genes have been identified and characterized in several plant species, but little information is available on the WD40 superfamily genes in peach. In this study, we identified 220 members of the WD40 superfamily in the peach genome, and these members were further classified into five subfamilies based on phylogenetic comparison with those in Arabidopsis. The members within each subfamily had conserved motifs and gene structures. The WD40 genes were unevenly distributed on chromosomes 1 to 8 of the peach genome. Additionally, 58 pairs of paralog WD40 members were found on eight chromosomes in peach, and 242 pairs of orthologous WD40 genes in peach and Arabidopsis were matched. The 54 selected putative WD40 genes in peach had diverse expression patterns in red-fleshed and white-fleshed peach fruits at five developmental stages. Prupe.6G211800.1 was located only on the cytomembrane, while Prupe.1G428200.1 and Prupe.I003200.1 were located on both the cytomembrane and in the nucleus; Prupe.1G558700.1 was densely localized around the nuclear rim but relatively faintly localized in the nucleoplasm; Prupe.5G116300.1 was located in the nucleus and cytomembrane with strong signals but showed weak signals in the cytoplasm; and Prupe.8G212400.1 and Prupe.1G053600.1 were located mainly in the nuclear envelope and cytomembrane but relatively faintly in the nucleoplasm. This study provides a foundation for the further functional verification of WD40 genes in peach.
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61
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Challenges in the clinical interpretation of small de novo copy number variants in neurodevelopmental disorders. Gene 2019; 706:162-171. [PMID: 31085274 DOI: 10.1016/j.gene.2019.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/27/2019] [Accepted: 05/03/2019] [Indexed: 12/17/2022]
Abstract
In clinical genetics, the need to discriminate between benign and pathogenic variants identified in patients with neurodevelopmental disorders is an absolute necessity. Copy number variants (CNVs) of small size can enable the identification of genes that are critical for neurologic development. However, assigning a definite association with a specific disorder is a difficult task. Among 328 trios analyzed over seven years of activity in a single laboratory, we identified 19 unrelated patients (5.8%) who carried a small (<500 kb) de novo CNV. Four patients had an additional independent de novo CNV. Nine had a variant that could be assigned as definitely pathogenic, whereas the remaining CNVs were considered as variants of unknown significance (VUS). We report clinical and molecular findings of patients harboring VUS. We reviewed the medical literature available for genes impacted by CNVs, obtained the probability of truncating loss-of-function intolerance, and compared overlapping CNVs reported in databases. The classification of small non-recurrent CNVs remains difficult but, among our findings, we provide support for a role of SND1 in the susceptibility of autism, describe a new case of the rare 17p13.1 microduplication syndrome, and report an X-linked duplication involving KIF4A and DLG3 as a likely cause of epilepsy.
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62
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La Barbera L, Vedele F, Nobili A, D'Amelio M, Krashia P. Neurodevelopmental Disorders: Functional Role of Ambra1 in Autism and Schizophrenia. Mol Neurobiol 2019; 56:6716-6724. [PMID: 30915711 DOI: 10.1007/s12035-019-1557-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/13/2019] [Indexed: 12/19/2022]
Abstract
The activating molecule in Beclin-1-regulated autophagy (Ambra1) is a highly intrinsically disordered protein best known for its role as a mediator in autophagy, by favoring the formation of autophagosomes. Additional studies have revealed that Ambra1 is able to coordinate cell responses to stress conditions such as starvation, and it actively participates in cell proliferation, cytoskeletal modification, apoptosis, mitochondria removal, and cell cycle downregulation. All these functions highlight the importance of Ambra1 in crucial physiological events, including metabolism, cell death, and cell division. Importantly, Ambra1 is also crucial for proper embryonic development, and its complete absence in knock-out animal models leads to severe brain morphology defects. In line with this, it has recently been implicated in neurodevelopmental disorders affecting humans, particularly autism spectrum disorders and schizophrenia. Here, we discuss the recent links between Ambra1 and neurodevelopment, particularly focusing on its role during the maturation of hippocampal parvalbumin interneurons and its importance for maintaining a proper excitation/inhibition balance in the brain.
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Affiliation(s)
- Livia La Barbera
- Laboratory of Molecular Neurosciences, Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Systems Medicine, University of Rome 'Tor Vergata', Rome, Italy
| | - Francescangelo Vedele
- Laboratory of Molecular Neurosciences, Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Systems Medicine, University of Rome 'Tor Vergata', Rome, Italy
| | - Annalisa Nobili
- Laboratory of Molecular Neurosciences, Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Rome, Italy.,Unit of Molecular Neurosciences, Department of Medicine, University Campus-Biomedico, Rome, Italy
| | - Marcello D'Amelio
- Laboratory of Molecular Neurosciences, Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Rome, Italy. .,Unit of Molecular Neurosciences, Department of Medicine, University Campus-Biomedico, Rome, Italy.
| | - Paraskevi Krashia
- Laboratory of Molecular Neurosciences, Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Rome, Italy. .,Department of Systems Medicine, University of Rome 'Tor Vergata', Rome, Italy.
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63
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Portilla-Fernandez E, Ghanbari M, van Meurs JBJ, Danser AHJ, Franco OH, Muka T, Roks A, Dehghan A. Dissecting the association of autophagy-related genes with cardiovascular diseases and intermediate vascular traits: A population-based approach. PLoS One 2019; 14:e0214137. [PMID: 30908504 PMCID: PMC6433264 DOI: 10.1371/journal.pone.0214137] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 03/07/2019] [Indexed: 01/09/2023] Open
Abstract
Autophagy is involved in cellular homeostasis and maintenance and may play a role in cardiometabolic health. We aimed to elucidate the role of autophagy in cardiometabolic traits by investigating genetic variants and DNA methylation in autophagy-related genes in relation to cardiovascular diseases and related traits. To address this research question, we implemented a multidirectional approach using several molecular epidemiology tools, including genetic association analysis with genome wide association studies data and exome sequencing data and differential DNA methylation analysis. We investigated the 21 autophagy-related genes in relation to coronary artery disease and a number of cardiometabolic traits (blood lipids, blood pressure, glycemic traits, type 2 diabetes). We used data from the largest genome wide association studies as well as DNA methylation and exome sequencing data from the Rotterdam Study. Single-nucleotide polymorphism rs110389913 in AMBRA1 (p-value = 4.9×10-18) was associated with blood proinsulin levels, whereas rs6587988 in ATG4C and rs10439163 in ATG4D with lipid traits (ATG4C: p-value = 2.5×10-15 for total cholesterol and p-value = 3.1×10-18 for triglycerides, ATG4D: p-value = 9.9×10-12 for LDL and p-value = 1.3×10-10 for total cholesterol). Moreover, rs7635838 in ATG7 was associated with HDL (p-value = 1.9×10-9). Rs2447607 located in ATG7 showed association with systolic blood pressure and pulse pressure. Rs2424994 in MAP1LC3A was associated with coronary artery disease (p-value = 5.8×10-6). Furthermore, we identified association of an exonic variant located in ATG3 with diastolic blood pressure (p-value = 6.75×10-6). Using DNA methylation data, two CpGs located in ULK1 (p-values = 4.5×10-7 and 1×10-6) and two located in ATG4B (2×10-13 and 1.48×10-7) were significantly associated with both systolic and diastolic blood pressure. In addition one CpG in ATG4D was associated with HDL (p-value = 3.21×10-5). Our findings provide support for the role of autophagy in glucose and lipid metabolism, as well as blood pressure regulation.
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Affiliation(s)
- Eliana Portilla-Fernandez
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Internal Medicine, Division of Vascular Medicine and Pharmacology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Mohsen Ghanbari
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Joyce B. J. van Meurs
- Department of Internal Medicine, Division of Vascular Medicine and Pharmacology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - A. H. Jan Danser
- Department of Internal Medicine, Division of Vascular Medicine and Pharmacology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Oscar H. Franco
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Taulant Muka
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Anton Roks
- Department of Internal Medicine, Division of Vascular Medicine and Pharmacology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Abbas Dehghan
- Department of Epidemiology and Biostatistics, Imperial College London, London, England
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Lijie G, Yueyue Z, Nan Z, Ling W, Xuan W, Weijie Y. Mitsugumin 53 promotes mitochondrial autophagy through regulating Ambra1 expression in C2C12 myoblast cells. Cell Biol Int 2019; 43:290-298. [PMID: 30614598 DOI: 10.1002/cbin.11097] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 01/03/2019] [Indexed: 12/14/2022]
Abstract
In this study, we investigated the function of Mitsugumin 53 (MG53) in regulation of mitochondrial autophagy in skeletal muscle cells and explored its potential application in the prevention and treatment of skeletal muscle atrophy in rats with chronic kidney disease (CKD). The expression of autophagy beclin 1 regulator 1 (Ambra1) and MG53 in skeletal muscles of 5/6 nephrectomized rats was measured, and the effect of MG53 on mitochondrial autophagy of C2C12 myoblasts was investigated by in vitro experiments. Our results show the expression of Ambra1 and MG53 in the skeletal muscle of CKD rats was significantly decreased. In vitro experiments showed that MG53 overexpression could promote the expression of Ambra1 and mitochondrial autophagy in C2C12 cells, suggesting that recovery of autophagy by MG53 intervention may help remove abnormal mitochondria and alleviate muscle atrophy. In conclusion, the damaged or functionally incomplete mitochondria in CKD rats could not be effectively removed, which may be related to the low activity of Ambra1. In vitro experiments showed that MG53 overexpression could promote the expression of Ambra1 in C2C12 cells and restore mitochondrial autophagy. Whether MG53 can help remove abnormal mitochondria and relieve CKD-induced muscle atrophy requires further study.
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Affiliation(s)
- Gu Lijie
- Department of Nephrology, Shanghai General Hospital Affiliated to Shanghai Jiaotong University, Shanghai, 200080, China
| | - Zhang Yueyue
- Department of Nephrology, Shanghai General Hospital Affiliated to Shanghai Jiaotong University, Shanghai, 200080, China
| | - Zhu Nan
- Department of Nephrology, Shanghai General Hospital Affiliated to Shanghai Jiaotong University, Shanghai, 200080, China
| | - Wang Ling
- Department of Nephrology, Shanghai General Hospital Affiliated to Shanghai Jiaotong University, Shanghai, 200080, China
| | - Wang Xuan
- Department of Nephrology, Shanghai General Hospital Affiliated to Shanghai Jiaotong University, Shanghai, 200080, China
| | - Yuan Weijie
- Department of Nephrology, Shanghai General Hospital Affiliated to Shanghai Jiaotong University, Shanghai, 200080, China
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Sun WL, Wang L, Luo J, Zhu HW, Cai ZW. Ambra1 modulates the sensitivity of breast cancer cells to epirubicin by regulating autophagy via ATG12. Cancer Sci 2018; 109:3129-3138. [PMID: 30027574 PMCID: PMC6172055 DOI: 10.1111/cas.13743] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/11/2018] [Accepted: 07/13/2018] [Indexed: 12/18/2022] Open
Abstract
The sensitivity of breast cancer cells to epirubicin (EPI) is closely related to the efficacy of the drug and the prognosis of patients. A growing body of research has suggested that autophagy is involved in the treatment of a variety of cancers, including breast cancer, and modifies the sensitivity of anticancer drugs. However, the mechanism by which autophagy participates in cancer therapy and modulates drug sensitivity has not been fully elucidated. In this study, we showed that the expression of Autophagy/Beclin 1 regulator 1 (Ambra1), a key protein of autophagy, was negatively correlated with EPI sensitivity in breast cancer cells. In addition, it altered the sensitivity of breast cancer cells to EPI by regulating EPI-induced autophagy. As a potential mechanism, we demonstrated that autophagy-related protein 12 (ATG12) was a downstream protein that Ambra1-regulated EPI-induced autophagy. Therefore, Ambra1 plays an important role in regulating the sensitivity of breast cancer cells to EPI. And the regulatory effect of Ambra1 on EPI sensitivity is achieved through the regulation of autophagy by targeting ATG12. Overall, we propose a novel mechanism by which autophagy modulates the sensitivity of breast cancer cells to EPI. ATG12 is a novel targeting protein of Ambra1 in regulating EPI-induced autophagy. In addition, the important role of Ambra1 in modulating the sensitivity of breast cancer cells to EPI is confirmed in vivo. This finding indicates that Ambra1 might be a target for developing breast cancer treatments.
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Affiliation(s)
- Wei-Liang Sun
- Department of Medical Oncology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Li Wang
- Department of Medical Oncology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jie Luo
- Department of Medical Oncology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Hua-Wei Zhu
- Department of Medical Oncology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Zheng-Wen Cai
- Department of Medical Oncology, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
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66
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Miki Y, Shimoyama S, Kon T, Ueno T, Hayakari R, Tanji K, Matsumiya T, Tsushima E, Mori F, Wakabayashi K, Tomiyama M. Alteration of autophagy-related proteins in peripheral blood mononuclear cells of patients with Parkinson's disease. Neurobiol Aging 2017; 63:33-43. [PMID: 29223072 DOI: 10.1016/j.neurobiolaging.2017.11.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/25/2017] [Accepted: 11/09/2017] [Indexed: 01/09/2023]
Abstract
Previous postmortem studies demonstrated dysregulation of autophagy in patients with Parkinson's disease (PD). To clarify whether this alteration reflects a fundamental aspect of PD or represents the final stage of autophagy dysregulation resulting from a long neurodegenerative process, we focused on basal autophagy in peripheral blood mononuclear cells (PBMCs) of PD patients (n = 35) and controls (n = 23). The whole-transcriptome assay revealed downregulation of mRNAs for 6 core regulators of autophagy (UNC-51-like kinase [ULK] 3, autophagy-related [Atg] 2A, Atg4B, Atg5, Atg16L1, and histone deacetylase 6). Reverse transcription-polymerase chain reaction and Western blot analysis confirmed significantly increased protein levels of upstream autophagy (ULK1, Beclin1, and autophagy/beclin1 regulator 1) with negative feedback of mRNA expression for these proteins in PD. These protein levels were correlated with increased levels of α-synuclein in PBMCs. The expression level of the oligomeric form of α-synuclein in PBMCs paralleled the clinical severity of PD and the degeneration of cardiac sympathetic nerves. Basal activity of autophagy can be lower in patients with PD. Alteration of basal autophagy may be a fundamental aspect of PD.
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Affiliation(s)
- Yasuo Miki
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
| | - Shuji Shimoyama
- Research Center for Child Mental Development, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Tomoya Kon
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan
| | - Tatsuya Ueno
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan
| | - Ryo Hayakari
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kunikazu Tanji
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Tomoh Matsumiya
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Eiki Tsushima
- Department of Comprehensive Rehabilitation Science, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan
| | - Fumiaki Mori
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Koichi Wakabayashi
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Masahiko Tomiyama
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan
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Mitjans M, Begemann M, Ju A, Dere E, Wüstefeld L, Hofer S, Hassouna I, Balkenhol J, Oliveira B, van der Auwera S, Tammer R, Hammerschmidt K, Völzke H, Homuth G, Cecconi F, Chowdhury K, Grabe H, Frahm J, Boretius S, Dandekar T, Ehrenreich H. Sexual dimorphism of AMBRA1-related autistic features in human and mouse. Transl Psychiatry 2017; 7:e1247. [PMID: 28994820 PMCID: PMC5682605 DOI: 10.1038/tp.2017.213] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/01/2017] [Accepted: 08/17/2017] [Indexed: 12/18/2022] Open
Abstract
Ambra1 is linked to autophagy and neurodevelopment. Heterozygous Ambra1 deficiency induces autism-like behavior in a sexually dimorphic manner. Extraordinarily, autistic features are seen in female mice only, combined with stronger Ambra1 protein reduction in brain compared to males. However, significance of AMBRA1 for autistic phenotypes in humans and, apart from behavior, for other autism-typical features, namely early brain enlargement or increased seizure propensity, has remained unexplored. Here we show in two independent human samples that a single normal AMBRA1 genotype, the intronic SNP rs3802890-AA, is associated with autistic features in women, who also display lower AMBRA1 mRNA expression in peripheral blood mononuclear cells relative to female GG carriers. Located within a non-coding RNA, likely relevant for mRNA and protein interaction, rs3802890 (A versus G allele) may affect its stability through modification of folding, as predicted by in silico analysis. Searching for further autism-relevant characteristics in Ambra1+/- mice, we observe reduced interest of female but not male mutants regarding pheromone signals of the respective other gender in the social intellicage set-up. Moreover, altered pentylentetrazol-induced seizure propensity, an in vivo readout of neuronal excitation-inhibition dysbalance, becomes obvious exclusively in female mutants. Magnetic resonance imaging reveals mild prepubertal brain enlargement in both genders, uncoupling enhanced brain dimensions from the primarily female expression of all other autistic phenotypes investigated here. These data support a role of AMBRA1/Ambra1 partial loss-of-function genotypes for female autistic traits. Moreover, they suggest Ambra1 heterozygous mice as a novel multifaceted and construct-valid genetic mouse model for female autism.
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Affiliation(s)
- M Mitjans
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - M Begemann
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany,Department of Psychiatry and Psychotherapy, UMG, Georg-August-University, Göttingen, Germany
| | - A Ju
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - E Dere
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - L Wüstefeld
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - S Hofer
- Biomedizinische NMR Forschungs GmbH, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - I Hassouna
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - J Balkenhol
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
| | - B Oliveira
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - S van der Auwera
- Department of Psychiatry and Psychotherapy, University Medicine, and German Center for Neurodegenerative Diseases (DZNE) Greifswald, Greifswald, Germany
| | - R Tammer
- Biomedizinische NMR Forschungs GmbH, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - K Hammerschmidt
- Cognitive Ethology Laboratory, German Primate Center, Göttingen, Germany
| | - H Völzke
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - G Homuth
- Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - F Cecconi
- IRCCS Fondazione Santa Lucia and Department of Biology, University of Rome Tor Vergata, Rome, Italy,Unit of Cell Stress and Survival, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - K Chowdhury
- Department of Molecular Cell Biology, Max Planck Institute of Biophysical Chemistry, Göttingen, Germany
| | - H Grabe
- Department of Psychiatry and Psychotherapy, University Medicine, and German Center for Neurodegenerative Diseases (DZNE) Greifswald, Greifswald, Germany
| | - J Frahm
- Biomedizinische NMR Forschungs GmbH, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - S Boretius
- Department of Functional Imaging, German Primate Center, Leibniz Institute of Primate Research, Göttingen, Germany
| | - T Dandekar
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
| | - H Ehrenreich
- Department of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany,Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, Göttingen 37075, Germany. E-mail:
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68
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Nascimbeni AC, Codogno P, Morel E. Local detection of PtdIns3P at autophagosome biogenesis membrane platforms. Autophagy 2017; 13:1602-1612. [PMID: 28813193 DOI: 10.1080/15548627.2017.1341465] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Phosphatidylinositol 3-phosphate (PtdIns3P) is a key player of membrane trafficking regulation, mostly synthesized by the PIK3C3 lipid kinase. The presence of PtdIns3P on endosomes has been demonstrated; however, the role and dynamics of the pool of PtdIns3P dedicated to macroautophagy/autophagy remains elusive. Here we addressed this question by studying the mobilization of PtdIns3P in time and space during autophagosome biogenesis. We compared different dyes known to specifically detect PtdIns3P by fluorescence microscopy analysis, based on PtdIns3P-binding FYVE and PX domains, and show that these transfected dyes induce defects in endosomal dynamics as well as artificial and sustained autophagosome formation. In contrast, indirect use of recombinant FYVE enabled us to track and discriminate endosomal and autophagosomal pools of PtdIns3P. We used this method to analyze localization and dynamics of PtdIns3P subdomains on the endoplasmic reticulum, at sites of pre-autophagosome associated protein recruitment such as the PtdIns3P-binding ZFYVE1/DFCP1 and WIPI2 autophagy regulators. This approach thus revealed the presence of a specific pool of PtdIns3P at the site where autophagosome assembly is initiated.
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Affiliation(s)
- Anna Chiara Nascimbeni
- a Cell Biology Department , Institut Necker-Enfants Malades (INEM) , INSERM U1151-CNRS UMR 8253, Paris , France.,b Université Paris Descartes-Sorbonne Paris Cité , Paris , France
| | - Patrice Codogno
- a Cell Biology Department , Institut Necker-Enfants Malades (INEM) , INSERM U1151-CNRS UMR 8253, Paris , France.,b Université Paris Descartes-Sorbonne Paris Cité , Paris , France
| | - Etienne Morel
- a Cell Biology Department , Institut Necker-Enfants Malades (INEM) , INSERM U1151-CNRS UMR 8253, Paris , France.,b Université Paris Descartes-Sorbonne Paris Cité , Paris , France
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69
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Zhu W, Qu H, Xu K, Jia B, Li H, Du Y, Liu G, Wei HJ, Zhao HY. Differences in the starvation-induced autophagy response in MDA-MB-231 and MCF-7 breast cancer cells. Anim Cells Syst (Seoul) 2017; 21:190-198. [PMID: 30460069 PMCID: PMC6138357 DOI: 10.1080/19768354.2017.1330763] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/30/2017] [Accepted: 05/09/2017] [Indexed: 12/22/2022] Open
Abstract
Breast cancer is a heterogeneous disease with distinct subtypes that have made targeted therapy of breast cancer challenging. Previous studies have demonstrated that an altered autophagy capacity can influence the development of breast cancer. However, the molecular differences in starvation-induced autophagic responses in MDA-MB-231 and MCF-7 cells have not been fully elucidated. In this study, we found that an increase of LC3B-II protein expression level and a decrease of the p62 protein expression level in both cells treated by Earle’s balanced salt solution. Meanwhile, we observed an increase of autophagosome using transmission electron microscopy and an enhancement in the green fluorescence intensity of LC3B protein by confocal microscopy. Furthermore, we detected the expression of 13 autophagy-related (ATG) genes and 11 autophagy signaling pathway-related genes using qPCR. Among 13 ATG genes, we found that 6 genes were up-regulated in treated MDA-MB-231 cells, while 4 genes were up-regulated and 1 gene was down-regulated in treated MCF-7 cells. In addition, among 11 autophagy signaling pathway-related genes, 7 genes were up-regulated in treated MDA-MB-231 cells, while 5 genes were up-regulated and 1 gene was down-regulated in treated MCF-7 cells. These findings suggest that the autophagic response to starvation was different in the two treated cell lines, which will contribute to further study on the molecular mechanism of starvation-induced autophagy and improve the targeted therapy of breast cancer.
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Affiliation(s)
- Wanyun Zhu
- College of Pharmacy and Chemistry, Dali University, Dali, People's Republic of China.,State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, People's Republic of China
| | - Hao Qu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, People's Republic of China.,Key Laboratory of Agricultural Biodiversity and Plant Disease Management of China Education Ministry, Yunnan Agricultural University, Kunming, People's Republic of China.,College of Plant Protection, Yunnan Agricultural University, Kunming, People's Republic of China
| | - Kaixiang Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, People's Republic of China.,Key Laboratory of Agricultural Biodiversity and Plant Disease Management of China Education Ministry, Yunnan Agricultural University, Kunming, People's Republic of China.,College of Plant Protection, Yunnan Agricultural University, Kunming, People's Republic of China
| | - Baoyu Jia
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, People's Republic of China
| | - Haifeng Li
- College of Pharmacy and Chemistry, Dali University, Dali, People's Republic of China
| | - Yimin Du
- College of Pharmacy and Chemistry, Dali University, Dali, People's Republic of China
| | - Guangming Liu
- College of Pharmacy and Chemistry, Dali University, Dali, People's Republic of China
| | - Hong-Jiang Wei
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, People's Republic of China.,Key Laboratory of Animal Nutrition and Feed of Yunnan Province, Yunnan Agricultural University, Kunming, People's Republic of China
| | - Hong-Ye Zhao
- College of Pharmacy and Chemistry, Dali University, Dali, People's Republic of China.,State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, People's Republic of China.,Key Laboratory of Agricultural Biodiversity and Plant Disease Management of China Education Ministry, Yunnan Agricultural University, Kunming, People's Republic of China.,College of Plant Protection, Yunnan Agricultural University, Kunming, People's Republic of China
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70
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Miccoli A, Dalla Valle L, Carnevali O. The maternal control in the embryonic development of zebrafish. Gen Comp Endocrinol 2017; 245:55-68. [PMID: 27013380 DOI: 10.1016/j.ygcen.2016.03.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/16/2016] [Accepted: 03/19/2016] [Indexed: 12/13/2022]
Abstract
The maternal control directing the very first hours of life is of pivotal importance for ensuring proper development to the growing embryo. Thanks to the finely regulated inheritance of maternal factors including mRNAs and proteins produced during oogenesis and stored into the mature oocyte, the embryo is sustained throughout the so-called maternal-to-zygotic transition, a period in development characterized by a species-specific length in time, during which critical biological changes regarding cell cycle and zygotic transcriptional activation occur. In order not to provoke any kind of persistent damage, the process must be delicately balanced. Surprisingly, our knowledge as to the possible effects of beneficial bacteria regarding the modulation of the quality and/or quantity of both maternally-supplied and zygotically-transcribed mRNAs, is very limited. To date, only one group has investigated the consequences of the parentally-supplied Lactobacillus rhamnosus on the storage of mRNAs into mature oocytes, leading to an altered maternal control process in the F1 generation. Particular attention was called on the monitoring of several biomarkers involved in autophagy, apoptosis and axis patterning, while data on miRNA generation and pluripotency maintenance are herein presented for the first time, and can assist in laying the ground for further investigations in this field. In this review, the reader is supplied with the current knowledge on the above-mentioned biological process, first by drawing the general background and then by emphasizing the most important findings that have highlighted their focal role in normal animal development.
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Affiliation(s)
- Andrea Miccoli
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Ancona, Italy
| | | | - Oliana Carnevali
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Ancona, Italy.
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71
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Hong-Brown LQ, Brown CR, Navaratnarajah M, Lang CH. FoxO1-AMPK-ULK1 Regulates Ethanol-Induced Autophagy in Muscle by Enhanced ATG14 Association with the BECN1-PIK3C3 Complex. Alcohol Clin Exp Res 2017; 41:895-910. [PMID: 28299793 PMCID: PMC5404978 DOI: 10.1111/acer.13377] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/10/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Excessive alcohol (EtOH) consumption causes an imbalance in protein metabolism. EtOH impairs protein synthesis in C2C12 myoblasts via a FoxO1-AMPK-TSC2-mTORC1 pathway and also induces protein degradation. As the underlying regulatory signaling cascades for these processes are currently poorly defined, we tested the hypothesis that alcohol-induced autophagy is mediated via activation of the PIK3C3 complex that is regulated by FoxO1-AMPK. METHODS C2C12 myoblasts were incubated with EtOH for various periods of time, and autophagy pathway-related proteins were assessed by Western blotting and immunoprecipitation. Expression of targeted genes was suppressed using electroporation of specific siRNAs and chemical inhibitors. RESULTS Incubation of C2C12 myoblasts with 100 mM EtOH increased the autophagy markers LC3B-II and ATG7, whereas levels of SQSTM1/p62 decreased. The lysosomal inhibitor bafilomycin A1 caused a similar response, although there was no additive effect when combined with EtOH. EtOH altered ULK1 S555 and S757 phosphorylation in a time- and AMPK-dependent manner. The activation of AMPK and ULK1 was associated with increased BECN1 (S93, S14) and PIK3C3/VPS34 (S164) phosphorylation as well as increased total ATG14 and PIK3C3. These changes promoted formation of the ATG14-AMBRA1-BECN1-PIK3C3 proautophagy complex that is important in autophagosome formation. EtOH-induced changes were not associated with increased production of PtdIns3P, which may be due to enhanced PIK3C3 complex binding with 14-3-3θ. Reduction of AMPK using siRNA suppressed the stimulatory effect of EtOH on BECN1 S93, BECN1 S14, and PIK3C3 S164 phosphorylation in a time-dependent manner. Likewise, knockdown of AMPK or chemical inhibition of FoxO1 attenuated phosphorylation of ULK1 at both residues. Knockdown of ULK1 or BECN1 antagonized the effect of EtOH on LC3B-II, SQSTM1, and ATG7 protein expression. CONCLUSIONS EtOH-induced autophagy is mediated through changes in phosphorylation and interaction of various PIK3C3 complex components. This, in turn, is regulated either directly via FoxO1-AMPK or indirectly via the FoxO1-AMPK-ULK1 signaling cascade in a mTORC1-independent or mTORC1-dependent manner.
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Affiliation(s)
- Ly Q. Hong-Brown
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA 17033
| | - C. Randell Brown
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA 17033
| | - Maithili Navaratnarajah
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA 17033
| | - Charles H. Lang
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA 17033
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Cancer/Testis Antigens: "Smart" Biomarkers for Diagnosis and Prognosis of Prostate and Other Cancers. Int J Mol Sci 2017; 18:ijms18040740. [PMID: 28362316 PMCID: PMC5412325 DOI: 10.3390/ijms18040740] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 03/22/2017] [Accepted: 03/27/2017] [Indexed: 12/22/2022] Open
Abstract
A clinical dilemma in the management of prostate cancer (PCa) is to distinguish men with aggressive disease who need definitive treatment from men who may not require immediate intervention. Accurate prediction of disease behavior is critical because radical treatment is associated with high morbidity. Here, we highlight the cancer/testis antigens (CTAs) as potential PCa biomarkers. The CTAs are a group of proteins that are typically restricted to the testis in the normal adult but are aberrantly expressed in several types of cancers. Interestingly, >90% of CTAs are predicted to belong to the realm of intrinsically disordered proteins (IDPs), which do not have unique structures and exist as highly dynamic conformational ensembles, but are known to play important roles in several biological processes. Using prostate-associated gene 4 (PAGE4) as an example of a disordered CTA, we highlight how IDP conformational dynamics may regulate phenotypic heterogeneity in PCa cells, and how it may be exploited both as a potential biomarker as well as a promising therapeutic target in PCa. We also discuss how in addition to intrinsic disorder and post-translational modifications, structural and functional variability induced in the CTAs by alternate splicing represents an important feature that might have different roles in different cancers. Although it is clear that significant additional work needs to be done in the outlined direction, this novel concept emphasizing (multi)functionality as an important trait in selecting a biomarker underscoring the theranostic potential of CTAs that is latent in their structure (or, more appropriately, the lack thereof), and casts them as next generation or “smart” biomarker candidates.
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73
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Miki Y, Tanji K, Mori F, Tatara Y, Utsumi J, Sasaki H, Kakita A, Takahashi H, Fimia GM, Wakabayashi K. AMBRA1, a novel α-synuclein-binding protein, is implicated in the pathogenesis of multiple system atrophy. Brain Pathol 2017; 28:28-42. [PMID: 27875637 DOI: 10.1111/bpa.12461] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 11/19/2016] [Indexed: 12/20/2022] Open
Abstract
The accumulation of abnormal α-synuclein is the major histopathological feature of Lewy body disease and multiple system atrophy (MSA), which are referred to as synucleinopathies. Cytoplasmic degradation systems, such as the autophagy-lysosome and proteasome pathways, are involved in their pathogenesis. Autophagy is tightly regulated by several upstream proteins including UNC-51-like kinase 1/2, beclin1, vacuolar protein sorting-associated protein 34 and autophagy/beclin1 regulator 1 (AMBRA1). Recently, we revealed that both cortical and brainstem-type Lewy bodies were immunopositive for several upstream proteins of autophagy. Therefore, we conducted the present study to elucidate the role of upstream proteins of autophagy in the pathogenesis of MSA. Pathological and biochemical analyses using human brain samples revealed that AMBRA1 is a component of the pathological hallmarks of MSA and upstream proteins of autophagy are impaired in the MSA brain. In vitro and in vivo analyses revealed a ninefold stronger affinity of AMBRA1 with α-synuclein phosphorylated at serine 129 compared with non-phosphorylated α-synuclein. Furthermore, a weak but significant correlation between AMBRA1 overexpression and reduction of abnormal α-synuclein was observed. Silencing AMBRA1 function caused aggregates of α-synuclein in the cytoplasm of mouse primary cultured neurons, which was simulated by the treatment of Bafilomycin, an autophagy inhibitor. Our results demonstrated for the first time that AMBRA1 is a novel hub binding protein of α-synuclein and plays a central role in the pathogenesis of MSA through the degradative dynamics of α-synuclein. These results raise the possibility that molecular modulation targeting AMBRA1 can be a promising candidate for the treatment of synucleinopathies.
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Affiliation(s)
- Yasuo Miki
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, 036-8562, Japan
| | - Kunikazu Tanji
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, 036-8562, Japan
| | - Fumiaki Mori
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, 036-8562, Japan
| | - Yota Tatara
- Department of Glycotechnology, Hirosaki University Graduate School of Medicine, Hirosaki, 036-8562, Japan
| | - Jun Utsumi
- Department of Neurology, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Hidenao Sasaki
- Department of Neurology, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Akiyoshi Kakita
- Department of Pathological Neuroscience, Center for Bioresource-based Researches, Brain Research Institute, University of Niigata, Niigata, 951-8585, Japan
| | - Hitoshi Takahashi
- Department of Pathology, Brain Research Institute, University of Niigata, Niigata, 951-8585, Japan
| | - Gian Maria Fimia
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), Università del Salento, Lecce, Italy.,Department of Epidemiology and Preclinical Research, INMI L. Spallanzani IRCCS, Rome, Italy
| | - Koichi Wakabayashi
- Department of Neuropathology, Institute of Brain Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, 036-8562, Japan
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74
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Martinez-Vicente M. Neuronal Mitophagy in Neurodegenerative Diseases. Front Mol Neurosci 2017; 10:64. [PMID: 28337125 PMCID: PMC5340781 DOI: 10.3389/fnmol.2017.00064] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 02/24/2017] [Indexed: 01/01/2023] Open
Abstract
Neuronal homeostasis depends on the proper functioning of different quality control systems. All intracellular components are subjected to continuous turnover through the coordinated synthesis, degradation and recycling of their constituent elements. Autophagy is the catabolic mechanism by which intracellular cytosolic components, including proteins, organelles, aggregates and any other intracellular materials, are delivered to lysosomes for degradation. Among the different types of selective autophagy described to date, the process of mitophagy involves the selective autophagic degradation of mitochondria. In this way, mitophagy is responsible for basal mitochondrial turnover, but can also be induced under certain physiological or pathogenic conditions to eliminate unwanted or damaged mitochondria. Dysfunctional cellular proteolytic systems have been linked extensively to neurodegenerative diseases (ND) like Alzheimer’s disease (AD), Parkinson’s disease (PD), or Huntington’s disease (HD), with autophagic failure being one of the main factors contributing to neuronal cell death in these diseases. Neurons are particularly vulnerable to autophagic impairment as well as to mitochondrial dysfunction, due mostly to their particular high energy dependence and to their post-mitotic nature. The accurate and proper degradation of dysfunctional mitochondria by mitophagy is essential for maintaining control over mitochondrial quality and quantity in neurons. In this report, I will review the role of mitophagy in neuronal homeostasis and the consequences of its dysfunction in ND.
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Affiliation(s)
- Marta Martinez-Vicente
- Neurodegenerative Diseases Research Group, Vall d'Hebron Research InstituteBarcelona, Spain; Autonomous University of Barcelona (UAB)Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)Barcelona, Spain
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75
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Nascimbeni AC, Codogno P, Morel E. Phosphatidylinositol-3-phosphate in the regulation of autophagy membrane dynamics. FEBS J 2017; 284:1267-1278. [PMID: 27973739 DOI: 10.1111/febs.13987] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/15/2016] [Accepted: 12/07/2016] [Indexed: 12/30/2022]
Abstract
Phosphatidylinositol-3-phosphate (PI3P) is a key player in membrane dynamics and trafficking regulation. Most PI3P is associated with endosomal membranes and with the autophagosome preassembly machinery, presumably at the endoplasmic reticulum. The enzyme responsible for most PI3P synthesis, VPS34 and proteins such as Beclin1 and ATG14L that regulate PI3P levels are positive modulators of autophagy initiation. It had been assumed that a local PI3P pool was present at autophagosomes and preautophagosomal structures, such as the omegasome and the phagophore. This was recently confirmed by the demonstration that PI3P-binding proteins participate in the complex sequence of signalling that results in autophagosome assembly and activity. Here we summarize the historical discoveries of PI3P lipid kinase involvement in autophagy, and we discuss the proposed role of PI3P during autophagy, notably during the autophagosome biogenesis sequence.
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Affiliation(s)
- Anna Chiara Nascimbeni
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, France
| | - Patrice Codogno
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, France
| | - Etienne Morel
- Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Paris, France.,Université Paris Descartes-Sorbonne Paris Cité, France
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76
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Di Rita A, Strappazzon F. AMBRA1, a Novel BH3-Like Protein: New Insights Into the AMBRA1-BCL2-Family Proteins Relationship. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 330:85-113. [PMID: 28215535 DOI: 10.1016/bs.ircmb.2016.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cellular homeostasis swings like a pendulum backward and forward between life and death. Two of the main processes, which regulate this equilibrium, are autophagy and apoptosis. While autophagy is a highly conserved self-digestion mechanism that mediates degradation of damaged or surplus components, apoptosis is a programmed cell suicide in which typical death signals induce the elimination of undesired cells. Both these processes are highly regulated by complex molecular machineries, including some common proteins whose "dual role" favors one process or the other. Among these proteins, the well-known antiapoptotic factor BCL2 downregulates autophagy through interactions with the essential autophagic effectors, BECN1/BECLIN 1 and AMBRA1. Recently, we have demonstrated that the proautophagic protein AMBRA1 contains a BH3 domain necessary for AMBRA1 binding with the antiapoptotic factor BCL2. We found that the AMBRA1-BCL2 couple have a "dual role" in autophagy and apoptosis: the mitochondrial pool of BCL2 is able to inhibit AMBRA1-dependent autophagy, whereas in cell death conditions, the cleaved form of AMBRA1 (AMBRA1CT), resulting from CASP/CASPASES-cleavage, abrogates the prosurvival activity of BCL2 and promotes a proapoptotic amplification loop. The CASP-cleaved form of AMBRA1 bound other antiapoptotic members of the BCL2 family proteins such as MCL1 and BCL2L1/BCL-X; by contrast, no binding could be detected with the proapoptotic-BCL2 factors such as BAK1/BAK and BAX. These findings underline an intricate interplay between autophagy and cell death in which the proautophagic protein AMBRA1 and the antiapoptotic BCL2 family members are the major players. Here, we give an overview of the AMBRA1-BCL2 family proteins interactome and its involvement in controlling life and cell death. We discuss a putative therapeutic target which offers the novel BH3 motif identified in the C-terminal part of AMBRA1.
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Affiliation(s)
- A Di Rita
- IRCCS Santa Lucia Foundation, Rome, Italy; University of Rome Tor Vergata, Rome, Italy
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77
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Autophagy in kidney disease and aging: lessons from rodent models. Kidney Int 2016; 90:950-964. [DOI: 10.1016/j.kint.2016.04.014] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 04/17/2016] [Accepted: 04/20/2016] [Indexed: 12/14/2022]
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78
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Mei Y, Glover K, Su M, Sinha SC. Conformational flexibility of BECN1: Essential to its key role in autophagy and beyond. Protein Sci 2016; 25:1767-85. [PMID: 27414988 DOI: 10.1002/pro.2984] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 07/09/2016] [Accepted: 07/12/2016] [Indexed: 01/16/2023]
Abstract
BECN1 (Beclin 1), a highly conserved eukaryotic protein, is a key regulator of autophagy, a cellular homeostasis pathway, and also participates in vacuolar protein sorting, endocytic trafficking, and apoptosis. BECN1 is important for embryonic development, the innate immune response, tumor suppression, and protection against neurodegenerative disorders, diabetes, and heart disease. BECN1 mediates autophagy as a core component of the class III phosphatidylinositol 3-kinase complexes. However, the exact mechanism by which it regulates the activity of these complexes, or mediates its other diverse functions is unclear. BECN1 interacts with several diverse protein partners, perhaps serving as a scaffold or interaction hub for autophagy. Based on extensive structural, biophysical and bioinformatics analyses, BECN1 consists of an intrinsically disordered region (IDR), which includes a BH3 homology domain (BH3D); a flexible helical domain (FHD); a coiled-coil domain (CCD); and a β-α-repeated autophagy-specific domain (BARAD). Each of these BECN1 domains mediates multiple diverse interactions that involve concomitant conformational changes. Thus, BECN1 conformational flexibility likely plays a key role in facilitating diverse protein interactions. Further, BECN1 conformation and interactions are also modulated by numerous post-translational modifications. A better structure-based understanding of the interplay between different BECN1 conformational and binding states, and the impact of post-translational modifications will be essential to elucidating the mechanism of its multiple biological roles.
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Affiliation(s)
- Yang Mei
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050
| | - Karen Glover
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050
| | - Minfei Su
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050
| | - Sangita C Sinha
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050.
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79
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Strappazzon F, Di Rita A, Cianfanelli V, D'Orazio M, Nazio F, Fimia GM, Cecconi F. Prosurvival AMBRA1 turns into a proapoptotic BH3-like protein during mitochondrial apoptosis. Autophagy 2016; 12:963-75. [PMID: 27123694 PMCID: PMC4922440 DOI: 10.1080/15548627.2016.1164359] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 03/02/2016] [Accepted: 03/07/2016] [Indexed: 12/17/2022] Open
Abstract
Autophagy and apoptosis are 2 stress-response mechanisms that are closely interconnected. However, the molecular interplays between these 2 pathways remain to be clarified. Here we report that the crucial proautophagic factor AMBRA1 can act as a positive mediator of mitochondrial apoptosis. Indeed, we show that, in a proapoptotic positive feedback loop, the C-terminal part of AMBRA1, generated by CASP/CASPASE cleavage upon apoptosis induction, inhibits the antiapoptotic factor BCL2 by a direct binding through its BH3-like domain. The mitochondrial AMBRA1-BCL2 complex is thus at the crossroad between autophagy and cell death and may represent a novel target in development of therapeutic approaches in clinical diseases.
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Affiliation(s)
| | - Anthea Di Rita
- IRCCS Fondazione Santa Lucia, Rome, Italy
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Valentina Cianfanelli
- Unit of Cell Stress and Survival, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Melania D'Orazio
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Francesca Nazio
- IRCCS Fondazione Santa Lucia, Rome, Italy
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Gian Maria Fimia
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
- National Institute for Infectious Diseases ‘L. Spallanzani’ IRCCS, Rome, Italy
| | - Francesco Cecconi
- IRCCS Fondazione Santa Lucia, Rome, Italy
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
- Unit of Cell Stress and Survival, Danish Cancer Society Research Center, Copenhagen, Denmark
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80
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Wesselborg S, Stork B. Autophagy signal transduction by ATG proteins: from hierarchies to networks. Cell Mol Life Sci 2015; 72:4721-57. [PMID: 26390974 PMCID: PMC4648967 DOI: 10.1007/s00018-015-2034-8] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 08/13/2015] [Accepted: 08/31/2015] [Indexed: 02/07/2023]
Abstract
Autophagy represents an intracellular degradation process which is involved in both cellular homeostasis and disease settings. In the last two decades, the molecular machinery governing this process has been characterized in detail. To date, several key factors regulating this intracellular degradation process have been identified. The so-called autophagy-related (ATG) genes and proteins are central to this process. However, several additional molecules contribute to the outcome of an autophagic response. Several review articles describing the molecular process of autophagy have been published in the recent past. In this review article we would like to add the most recent findings to this knowledge, and to give an overview of the network character of the autophagy signaling machinery.
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Affiliation(s)
- Sebastian Wesselborg
- Institute of Molecular Medicine I, Heinrich-Heine-University, Universitätsstr. 1, Building 23.12, 40225, Düsseldorf, Germany
| | - Björn Stork
- Institute of Molecular Medicine I, Heinrich-Heine-University, Universitätsstr. 1, Building 23.12, 40225, Düsseldorf, Germany.
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81
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Burada F, Nicoli ER, Ciurea ME, Uscatu DC, Ioana M, Gheonea DI. Autophagy in colorectal cancer: An important switch from physiology to pathology. World J Gastrointest Oncol 2015; 7:271-284. [PMID: 26600927 PMCID: PMC4644850 DOI: 10.4251/wjgo.v7.i11.271] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 06/20/2015] [Accepted: 09/30/2015] [Indexed: 02/05/2023] Open
Abstract
Colorectal cancer (CRC) remains a leading cause of cancer death in both men and women worldwide. Among the factors and mechanisms that are involved in the multifactorial etiology of CRC, autophagy is an important transformational switch that occurs when a cell shifts from normal to malignant. In recent years, multiple hypotheses have been considered regarding the autophagy mechanisms that are involved in cancer. The currently accepted hypothesis is that autophagy has dual and contradictory roles in carcinogenesis, but the precise mechanisms leading to autophagy in cancer are not yet fully defined and seem to be context dependent. Autophagy is a surveillance mechanism used by normal cells that protects them from the transformation to malignancy by removing damaged organelles and aggregated proteins and by reducing reactive oxygen species, mitochondrial abnormalities and DNA damage. However, autophagy also supports tumor formation by promoting access to nutrients that are critical to the metabolism and growth of tumor cells and by inhibiting cellular death and increasing drug resistance. Autophagy studies in CRC have focused on several molecules, mainly microtubule-associated protein 1 light chain 3, beclin 1, and autophagy related 5, with conflicting results. Beneficial effects were observed for some agents that modulate autophagy in CRC either alone or, more often, in combination with other agents. More extensive studies are needed in the future to clarify the roles of autophagy-related genes and modulators in colorectal carcinogenesis, and to develop potential beneficial agents for the prognosis and treatment of CRC.
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