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Kim M, Lu L, Dvornikov AV, Ma X, Ding Y, Zhu P, Olson TM, Lin X, Xu X. TFEB Overexpression, Not mTOR Inhibition, Ameliorates RagC S75Y Cardiomyopathy. Int J Mol Sci 2021; 22:5494. [PMID: 34071043 PMCID: PMC8197163 DOI: 10.3390/ijms22115494] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 12/29/2022] Open
Abstract
A de novo missense variant in Rag GTPase protein C (RagCS75Y) was recently identified in a syndromic dilated cardiomyopathy (DCM) patient. However, its pathogenicity and the related therapeutic strategy remain unclear. We generated a zebrafish RragcS56Y (corresponding to human RagCS75Y) knock-in (KI) line via TALEN technology. The KI fish manifested cardiomyopathy-like phenotypes and poor survival. Overexpression of RagCS75Y via adenovirus infection also led to increased cell size and fetal gene reprogramming in neonatal rat ventricle cardiomyocytes (NRVCMs), indicating a conserved mechanism. Further characterization identified aberrant mammalian target of rapamycin complex 1 (mTORC1) and transcription factor EB (TFEB) signaling, as well as metabolic abnormalities including dysregulated autophagy. However, mTOR inhibition failed to ameliorate cardiac phenotypes in the RagCS75Y cardiomyopathy models, concomitant with a failure to promote TFEB nuclear translocation. This observation was at least partially explained by increased and mTOR-independent physical interaction between RagCS75Y and TFEB in the cytosol. Importantly, TFEB overexpression resulted in more nuclear TFEB and rescued cardiomyopathy phenotypes. These findings suggest that S75Y is a pathogenic gain-of-function mutation in RagC that leads to cardiomyopathy. A primary pathological step of RagCS75Y cardiomyopathy is defective mTOR-TFEB signaling, which can be corrected by TFEB overexpression, but not mTOR inhibition.
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Affiliation(s)
- Maengjo Kim
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
| | - Linghui Lu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Alexey V. Dvornikov
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, AZ 85721, USA
| | - Xiao Ma
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
| | - Yonghe Ding
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
| | - Ping Zhu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
| | - Timothy M. Olson
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
- Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, MN 55901, USA
| | - Xueying Lin
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55901, USA; (M.K.); (L.L.); (A.V.D.); (X.M.); (Y.D.); (P.Z.); (X.L.)
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA;
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Flamm H. [ Ragsorters' Disease-150 years ago a new, today a vanished occupational disease in Austria]. Wien Med Wochenschr 2020; 170:76-87. [PMID: 31912381 DOI: 10.1007/s10354-019-00731-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 12/15/2019] [Indexed: 10/25/2022]
Abstract
In 1870 17 women who were engaged with shredding and sorting rags in a Lower-Austrian papermill fell ill with a highly febrile lung affection; nine of them died. Hitherto this illness was not recognised as a separate disease, the "Ragsorters' Disease". The rags were used garments and household textiles collected mostly in eastern countries as well as used contaminated bandages of hospitals. The manipulation with the rags produced much dust which was inhaled by the women, provoking some different illnesses, including the Ragsorters' Disease. Mostly without prodromes a heavy lobar or lobular pneumonia with atelectasis and oedematous softenings of the lung tissue. Histologically impressive were masses of bacteria on and between the epithelia cells and inside the walls of the alveoli. The bacteria were diagnosed as Bac. anthracis.The Ragsorters' Disease could be restrained by technical improvements and disinfection. Finally, it was extinguished by the replacement of rags by woodpulp.
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Affiliation(s)
- Heinz Flamm
- , Martinstraße 7, 3400, Klosterneuburg, Österreich.
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Abstract
The Rags represent a unique family of evolutionarily conserved, heterodimeric, lysosome-localized small GTPases that play an indispensible role in regulating cellular metabolism in response to various amino acid signaling mechanisms. Rapid progress in the field has begun to unveil a picture in which Rags act as central players in translating information regarding cellular amino acid levels by modulating their nucleotide binding status through an ensemble of support proteins localized in and around the lysosomes. By cooperating with other signaling pathways that converge on the lysosomes, Rags promote anabolic processes through positively affecting mTORC1 signaling in the presence of abundant amino acids. Conversely, Rag inactivation plays an indispensible role in switching cellular metabolism into a catabolic paradigm by promoting the activity of the master lysosomal/autophagic transcription factors TFEB and TFE3. Precise control of Rag signaling is necessary for cells to adapt to constantly changing cellular demands and emerging evidence has highlighted their importance in a wide variety of developmental and pathological conditions.
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Affiliation(s)
- Owen A Brady
- a Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda , MD , USA
| | - Heba I Diab
- a Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda , MD , USA
| | - Rosa Puertollano
- a Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda , MD , USA
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Averous J, Lambert-Langlais S, Carraro V, Gourbeyre O, Parry L, B'Chir W, Muranishi Y, Jousse C, Bruhat A, Maurin AC, Proud CG, Fafournoux P. Requirement for lysosomal localization of mTOR for its activation differs between leucine and other amino acids. Cell Signal 2014; 26:1918-27. [PMID: 24793303 DOI: 10.1016/j.cellsig.2014.04.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 04/27/2014] [Indexed: 11/17/2022]
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth and metabolism. It controls many cell functions by integrating nutrient availability and growth factor signals. Amino acids, and in particular leucine, are among the main positive regulators of mTORC1 signaling. The current model for the regulation of mTORC1 by amino acids involves the movement of mTOR to the lysosome mediated by the Rag-GTPases. Here, we have examined the control of mTORC1 signaling and mTOR localization by amino acids and leucine in serum-fed cells, because both serum growth factors (or, e.g., insulin) and amino acids are required for full activation of mTORC1 signaling. We demonstrate that mTORC1 activity does not closely correlate with the lysosomal localization of mTOR. In particular, leucine controls mTORC1 activity without any detectable modification of the lysosomal localization of mTOR, indicating that the signal(s) exerted by leucine is likely distinct from those exerted by other amino acids. In addition, knock-down of the Rag-GTPases attenuated the inhibitory effect of amino acid- or leucine-starvation on the phosphorylation of mTORC1 targets. Furthermore, data from cells where Rag expression has been knocked down revealed that leucine can promote mTORC1 signaling independently of the lysosomal localization of mTOR. Our data complement existing models for the regulation of mTORC1 by amino acids and provide new insights into this important topic.
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Affiliation(s)
- Julien Averous
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France.
| | - Sarah Lambert-Langlais
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Valérie Carraro
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Ophélie Gourbeyre
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Laurent Parry
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Wafa B'Chir
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Yuki Muranishi
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Céline Jousse
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Alain Bruhat
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Anne-Catherine Maurin
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France
| | - Christopher G Proud
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Pierre Fafournoux
- INRA, UMR 1019 Nutrition Humaine, Centre de Clermont-Ferrand-Theix, F-63122 Saint Genès Champanelle, France; Université Clermont 1, UFR Médecine, UMR 1019 Nutrition Humaine, Clermont-Ferrand, France.
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