Proline biosynthesis is a vent for TGFβ-induced mitochondrial redox stress Journal Article
| Authors: | Schwörer, S.; Berisa, M.; Violante, S.; Qin, W.; Zhu, J.; Hendrickson, R. C.; Cross, J. R.; Thompson, C. B. |
| Article Title: | Proline biosynthesis is a vent for TGFβ-induced mitochondrial redox stress |
| Abstract: | The production and secretion of matrix proteins upon stimulation of fibroblasts by transforming growth factor-beta (TGFβ) play a critical role in wound healing. How TGFβ supports the bioenergetic cost of matrix protein synthesis is not fully understood. Here, we show that TGFβ promotes protein translation at least in part by increasing the mitochondrial oxidation of glucose and glutamine carbons to support the bioenergetic demand of translation. Surprisingly, we found that in addition to stimulating the entry of glucose and glutamine carbon into the TCA cycle, TGFβ induced the biosynthesis of proline from glutamine in a Smad4-dependent fashion. Metabolic manipulations that increased mitochondrial redox generation promoted proline biosynthesis, while reducing mitochondrial redox potential and/or ATP synthesis impaired proline biosynthesis. Thus, proline biosynthesis acts as a redox vent, preventing the TGFβ-induced increase in mitochondrial glucose and glutamine catabolism from generating damaging reactive oxygen species (ROS) when TCA cycle activity exceeds the ability of oxidative phosphorylation to convert mitochondrial redox potential into ATP. In turn, the enhanced synthesis of proline supports TGFβ-induced production of matrix proteins. © 2020 The Authors |
| Keywords: | controlled study; human cell; nonhuman; dna synthesis; animal cell; mouse; metabolism; animal tissue; transforming growth factor beta; animal experiment; animal model; fibrosis; collagen; reactive oxygen metabolite; glucose; adenosine triphosphate; glycolysis; oxidative phosphorylation; matrix protein; glutamine; metabolic regulation; proline; citric acid cycle; mitochondrial respiration; smad4 protein; amino acid synthesis; tgfΒ; redox stress; human; priority journal; article; oxidation reduction potential |
| Journal Title: | EMBO Journal |
| Volume: | 39 |
| Issue: | 8 |
| ISSN: | 0261-4189 |
| Publisher: | Wiley Blackwell |
| Date Published: | 2020-04-15 |
| Start Page: | e103334 |
| Language: | English |
| DOI: | 10.15252/embj.2019103334 |
| PUBMED: | 32134147 |
| PROVIDER: | scopus |
| PMCID: | PMC7156964 |
| DOI/URL: | |
| Notes: | Article -- Source: Scopus |
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