An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)

Background: ATM, the protein defective in the human genetic disorder, ataxia-telangiectasia (A-T) plays a central role in response to DNA double-strand breaks (DSBs) and in protecting the cell against oxidative stress. We showed that A-T cells are hypersensitive to metabolic stress which can be acco...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	A.J. Yeo, G.N. Subramanian, K.L. Chong, M. Gatei, R.G. Parton, D. Coman, M.F. Lavin
Formato:	article
Lenguaje:	EN
Publicado:	Elsevier 2021
Materias:	Ataxia-telangiectasia ATM Nutrient deprivation Endoplasmic reticulum–mitochondrial interaction Mitochondrial dysfunction Heptanoate (C7) Internal medicine RC31-1245
Acceso en línea:	https://doaj.org/article/25d6e71a108248368e69a3aaa026e679
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:25d6e71a108248368e69a3aaa026e679
record_format	dspace
spelling	oai:doaj.org-article:25d6e71a108248368e69a3aaa026e6792021-11-14T04:32:37ZAn anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)2212-877810.1016/j.molmet.2021.101354https://doaj.org/article/25d6e71a108248368e69a3aaa026e6792021-12-01T00:00:00Zhttp://www.sciencedirect.com/science/article/pii/S2212877821002015https://doaj.org/toc/2212-8778Background: ATM, the protein defective in the human genetic disorder, ataxia-telangiectasia (A-T) plays a central role in response to DNA double-strand breaks (DSBs) and in protecting the cell against oxidative stress. We showed that A-T cells are hypersensitive to metabolic stress which can be accounted for by a failure to exhibit efficient endoplasmic reticulum (ER)-mitochondrial signalling and Ca2+ transfer in response to nutrient deprivation resulting in mitochondrial dysfunction. The objective of the current study is to use an anaplerotic approach using the fatty acid, heptanoate (C7), a metabolic product of the triglyceride, triheptanoin to correct the defect in ER-mitochondrial signalling and enhance cell survival of A-T cells in response to metabolic stress. Methods: We treated control cells and A-T cells with the anaplerotic agent, heptanoate to determine their sensitivity to metabolic stress induced by inhibition of glycolysis with 2- deoxyglucose (2DG) using live-cell imaging to monitor cell survival for 72 h using the Incucyte system. We examined ER-mitochondrial signalling in A-T cells exposed to metabolic stress using a suite of techniques including immunofluorescence staining of Grp75, ER-mitochondrial Ca2+ channel, the VAPB-PTPIP51 ER-mitochondrial tether complexes as well as proximity ligation assays between Grp75-IP3R1 and VAPB1-PTPIP51 to establish a functional interaction between ER and mitochondria. Finally, we also performed metabolomic analysis using LC-MS/MS assay to determine altered levels of TCA intermediates A-T cells compared to healthy control cells. Results: We demonstrate that heptanoate corrects all aspects of the defective ER-mitochondrial signalling observed in A-T cells. Heptanoate enhances ER-mitochondrial contacts; increases the flow of calcium from the ER to the mitochondrion; restores normal mitochondrial function and mitophagy and increases the resistance of ATM-deficient cells and cells from A-T patients to metabolic stress-induced killing. The defect in mitochondrial function in ATM-deficient cells was accompanied by more reliance on aerobic glycolysis as shown by increased lactate dehydrogenase A (LDHA), accumulation of lactate, and reduced levels of both acetyl CoA and ATP which are all restored by heptanoate. Conclusions: We conclude that heptanoate corrects metabolic stress in A-T cells by restoring ER-mitochondria signalling and mitochondrial function and suggest that the parent compound, triheptanoin, has immense potential as a novel therapeutic agent for patients with A-T.A.J. YeoG.N. SubramanianK.L. ChongM. GateiR.G. PartonD. ComanM.F. LavinElsevierarticleAtaxia-telangiectasiaATMNutrient deprivationEndoplasmic reticulum–mitochondrial interactionMitochondrial dysfunctionHeptanoate (C7)Internal medicineRC31-1245ENMolecular Metabolism, Vol 54, Iss , Pp 101354- (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Ataxia-telangiectasia ATM Nutrient deprivation Endoplasmic reticulum–mitochondrial interaction Mitochondrial dysfunction Heptanoate (C7) Internal medicine RC31-1245
spellingShingle	Ataxia-telangiectasia ATM Nutrient deprivation Endoplasmic reticulum–mitochondrial interaction Mitochondrial dysfunction Heptanoate (C7) Internal medicine RC31-1245 A.J. Yeo G.N. Subramanian K.L. Chong M. Gatei R.G. Parton D. Coman M.F. Lavin An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)
description	Background: ATM, the protein defective in the human genetic disorder, ataxia-telangiectasia (A-T) plays a central role in response to DNA double-strand breaks (DSBs) and in protecting the cell against oxidative stress. We showed that A-T cells are hypersensitive to metabolic stress which can be accounted for by a failure to exhibit efficient endoplasmic reticulum (ER)-mitochondrial signalling and Ca2+ transfer in response to nutrient deprivation resulting in mitochondrial dysfunction. The objective of the current study is to use an anaplerotic approach using the fatty acid, heptanoate (C7), a metabolic product of the triglyceride, triheptanoin to correct the defect in ER-mitochondrial signalling and enhance cell survival of A-T cells in response to metabolic stress. Methods: We treated control cells and A-T cells with the anaplerotic agent, heptanoate to determine their sensitivity to metabolic stress induced by inhibition of glycolysis with 2- deoxyglucose (2DG) using live-cell imaging to monitor cell survival for 72 h using the Incucyte system. We examined ER-mitochondrial signalling in A-T cells exposed to metabolic stress using a suite of techniques including immunofluorescence staining of Grp75, ER-mitochondrial Ca2+ channel, the VAPB-PTPIP51 ER-mitochondrial tether complexes as well as proximity ligation assays between Grp75-IP3R1 and VAPB1-PTPIP51 to establish a functional interaction between ER and mitochondria. Finally, we also performed metabolomic analysis using LC-MS/MS assay to determine altered levels of TCA intermediates A-T cells compared to healthy control cells. Results: We demonstrate that heptanoate corrects all aspects of the defective ER-mitochondrial signalling observed in A-T cells. Heptanoate enhances ER-mitochondrial contacts; increases the flow of calcium from the ER to the mitochondrion; restores normal mitochondrial function and mitophagy and increases the resistance of ATM-deficient cells and cells from A-T patients to metabolic stress-induced killing. The defect in mitochondrial function in ATM-deficient cells was accompanied by more reliance on aerobic glycolysis as shown by increased lactate dehydrogenase A (LDHA), accumulation of lactate, and reduced levels of both acetyl CoA and ATP which are all restored by heptanoate. Conclusions: We conclude that heptanoate corrects metabolic stress in A-T cells by restoring ER-mitochondria signalling and mitochondrial function and suggest that the parent compound, triheptanoin, has immense potential as a novel therapeutic agent for patients with A-T.
format	article
author	A.J. Yeo G.N. Subramanian K.L. Chong M. Gatei R.G. Parton D. Coman M.F. Lavin
author_facet	A.J. Yeo G.N. Subramanian K.L. Chong M. Gatei R.G. Parton D. Coman M.F. Lavin
author_sort	A.J. Yeo
title	An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)
title_short	An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)
title_full	An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)
title_fullStr	An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)
title_full_unstemmed	An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)
title_sort	anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (a-t)
publisher	Elsevier
publishDate	2021
url	https://doaj.org/article/25d6e71a108248368e69a3aaa026e679
work_keys_str_mv	AT ajyeo ananapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT gnsubramanian ananapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT klchong ananapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT mgatei ananapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT rgparton ananapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT dcoman ananapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT mflavin ananapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT ajyeo anapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT gnsubramanian anapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT klchong anapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT mgatei anapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT rgparton anapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT dcoman anapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat AT mflavin anapleroticapproachtocorrectthemitochondrialdysfunctioninataxiatelangiectasiaat
_version_	1718429945359761408

An anaplerotic approach to correct the mitochondrial dysfunction in ataxia-telangiectasia (A-T)

Ejemplares similares