Enhanced Ca2+-channeling complex formation at the ER-mitochondria interface underlies the pathogenesis of alcohol-associated liver disease

Themis Thoudam, Dipanjan Chanda, Jung Yi Lee, Min Kyo Jung, Ibotombi Singh Sinam, Byung Gyu Kim, Bo Yoon Park, Woong Hee Kwon, Hyo Jeong Kim, Myeongjin Kim, Chae Won Lim, Hoyul Lee, Yang Hoon Huh, Caroline A. Miller, Romil Saxena, Nicholas J. Skill, Nazmul Huda, Praveen Kusumanchi, Jing Ma, Zhihong YangMin Ji Kim, Ji Young Mun, Robert A. Harris, Jae Han Jeon, Suthat Liangpunsakul, In Kyu Lee

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Ca2+ overload-induced mitochondrial dysfunction is considered as a major contributing factor in the pathogenesis of alcohol-associated liver disease (ALD). However, the initiating factors that drive mitochondrial Ca2+ accumulation in ALD remain elusive. Here, we demonstrate that an aberrant increase in hepatic GRP75-mediated mitochondria-associated ER membrane (MAM) Ca2+-channeling (MCC) complex formation promotes mitochondrial dysfunction in vitro and in male mouse model of ALD. Unbiased transcriptomic analysis reveals PDK4 as a prominently inducible MAM kinase in ALD. Analysis of human ALD cohorts further corroborate these findings. Additional mass spectrometry analysis unveils GRP75 as a downstream phosphorylation target of PDK4. Conversely, non-phosphorylatable GRP75 mutation or genetic ablation of PDK4 prevents alcohol-induced MCC complex formation and subsequent mitochondrial Ca2+ accumulation and dysfunction. Finally, ectopic induction of MAM formation reverses the protective effect of PDK4 deficiency in alcohol-induced liver injury. Together, our study defines a mediatory role of PDK4 in promoting mitochondrial dysfunction in ALD.

Original languageEnglish
Article number1703
JournalNature Communications
Volume14
Issue number1
DOIs
StatePublished - Dec 2023

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