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bioRxiv · 10.64898/2026.02.13.705622

Excessive Ca2+-dependent ER-mitochondrial contact stabilization by EFHD1 drives liver injury

Abstract

Metabolic-associated steatohepatitis (MASH) involves hepatocyte damage that cannot be explained solely by lipid accumulation. Here, to discover injury-specific pathways, we focused on a gene of uncertain function, EF-Hand Domain Family Member D1 (EFHD1), identified in human genome-wide association studies of liver injury but not liver fat. We show that EFHD1, a Ca2+-dependent actin crosslinker, stabilizes endoplasmic reticulum-mitochondria contact sites (ERMCS), detecting spatiotemporal coincidence of inter-organellar proximity and ER Ca2+ release. During MASH, EFHD1 upregulation drives pathological mitochondrial fragmentation via excessive contact persistence. This structural failure promotes mitochondrial double-stranded RNA escape and activation of a maladaptive antiviral PKR-dependent stress response, a causal relationship also supported by Mendelian randomization in humans. Consequently, inhibiting EFHD1 in human and mouse models blunts hepatocyte damage. These findings identify EFHD1 as a Ca2+-dependent ERMCS stabilizer, reveal a hepatocyte-intrinsic injury pathway, and suggest EFHD1 inhibition as a therapeutic strategy.

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BibTeXRIS

Eberhardt, D. R., Rekate, E. C., Masini, Y. B., Duron, H. E., Mollinedo, D., Velarde, A. M., Stucki, D., Price, T., Lee, S. H., Balderas, E., Rai, N. K., Bratt, A. R., Balynas, A. M., Stubben, C. J., Bia, R., Maity, S., Hartel, N., Yin, X., Corbin, A., Kumari, A., Nguyen, D. M., Shimura, D., Nguyen, V. D., Vinod, V., Chowdhury, K. H., Verdeguer, F., Zvick, J., Mimche, P. N., Boudina, S., Drakos, S. G., Aromolaran, A. S., Franklin, S., Garg, V., Shaw, R. M., Holland, W. L., Summers, S. A., Pezzolesi, M. G., Rutter, J., Evason, K. J., Chaudhuri, D.. 2026-02-16. Excessive Ca2+-dependent ER-mitochondrial contact stabilization by EFHD1 drives liver injury. https://doi.org/10.64898/2026.02.13.705622

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