Excessive EFHD1-dependent ER-mitochondrial contacts drive a maladaptive antiviral response in metabolic liver disease
David R. Eberhardt, Emma C. Rekate, Yasmin B. Masini, Hannah E. Duron, David Mollinedo, Adrian M. Velarde, Devorah Stucki, Tara R. Price, Sandra H.J. Lee, Enrique Balderas, Neeraj K. Rai, Ashley R. Bratt, Anthony M. Balynas, Chris J. Stubben, Ryan Bia, Sudipa Maity, Nicolas Hartel, Xue Yin, Andrea Corbin, Anshu Kumari, Dung M. Nguyen, Daisuke Shimura, Vu D. Nguyen, Vishaka Vinod, Kamrul H. Chowdhury, Francisco Verdeguer, Joel Zvick, Patrice N. Mimche, Sihem Boudina, Stavros G. Drakos, Ademuyiwa S. Aromolaran, Sarah Franklin, Vivek Garg, Robin M. Shaw, William L. Holland, Scott A. Summers, Marcus G. Pezzolesi, Jared Rutter, Kimberley J. Evason, Dipayan Chaudhuri
David R. Eberhardt, Emma C. Rekate, Yasmin B. Masini, Hannah E. Duron, David Mollinedo, Adrian M. Velarde, Devorah Stucki, Tara R. Price, Sandra H.J. Lee, Enrique Balderas, Neeraj K. Rai, Ashley R. Bratt, Anthony M. Balynas, Chris J. Stubben, Ryan Bia, Sudipa Maity, Nicolas Hartel, Xue Yin, Andrea Corbin, Anshu Kumari, Dung M. Nguyen, Daisuke Shimura, Vu D. Nguyen, Vishaka Vinod, Kamrul H. Chowdhury, Francisco Verdeguer, Joel Zvick, Patrice N. Mimche, Sihem Boudina, Stavros G. Drakos, Ademuyiwa S. Aromolaran, Sarah Franklin, Vivek Garg, Robin M. Shaw, William L. Holland, Scott A. Summers, Marcus G. Pezzolesi, Jared Rutter, Kimberley J. Evason, Dipayan Chaudhuri
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Research Article Cell biology Hepatology Metabolism

Excessive EFHD1-dependent ER-mitochondrial contacts drive a maladaptive antiviral response in metabolic liver disease

Abstract

Metabolic dysfunction–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 showed that EFHD1, a Ca2+-dependent actin cross-linker, stabilizes endoplasmic reticulum–mitochondria contact sites (ERMCS) by detecting spatiotemporal coincidence of interorganellar 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, protein kinase RNA-activated–associated 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.

Authors

David R. Eberhardt, Emma C. Rekate, Yasmin B. Masini, Hannah E. Duron, David Mollinedo, Adrian M. Velarde, Devorah Stucki, Tara R. Price, Sandra H.J. Lee, Enrique Balderas, Neeraj K. Rai, Ashley R. Bratt, Anthony M. Balynas, Chris J. Stubben, Ryan Bia, Sudipa Maity, Nicolas Hartel, Xue Yin, Andrea Corbin, Anshu Kumari, Dung M. Nguyen, Daisuke Shimura, Vu D. Nguyen, Vishaka Vinod, Kamrul H. Chowdhury, Francisco Verdeguer, Joel Zvick, Patrice N. Mimche, Sihem Boudina, Stavros G. Drakos, Ademuyiwa S. Aromolaran, Sarah Franklin, Vivek Garg, Robin M. Shaw, William L. Holland, Scott A. Summers, Marcus G. Pezzolesi, Jared Rutter, Kimberley J. Evason, Dipayan Chaudhuri

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Figure 6

Liver-specific EFHD1 inhibition reduces hepatocyte injury.

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Liver-specific EFHD1 inhibition reduces hepatocyte injury. (A) Hepatocyt...
(A) Hepatocyte-specific Efhd1 deletion via frameshift and early termination. (B) Western blot where heart is a control. (C) MitoTracker-stained isolated mouse hepatocytes. Right, boxed insets at higher magnification. (D) Automated iLastik analysis. Bar chart (top) shows mean effects; violin plot (bottom) shows full distribution. Dots in bar chart, average value per cell. (E–I) Assays following 4 weeks of CCl4 injection. (E and F) Serum liver enzymes. (G) Liver Masson’s trichrome staining. Fibrosis, blue. (H) Histopathological fibrosis score. (I) Fibrotic area from liver micrographs. (J and K) Human microtissue (J) triglyceride and (K) TNF-α production. (L–S) Assays on MASH diet and AAV8 treatment. (L and M) Serum liver enzymes. (N) Liver micrographs of Masson’s trichrome staining. (O) MASH activity score. (P) Histopathological inflammation score. (Q) Liver leukocyte nuclei cluster counts. (R) Histopathological fibrosis score. (S) Fibrotic area measured from liver micrographs. B–I and L–S used male mice. Clinical histopathological scoring in H, O, P, and R was assessed in blinded fashion by a liver pathologist. Linear mixed effects model: D. Mann-Whitney U test: E, F, H–K, O, P, and R. One-way ANOVA: L, M, Q, and S. N values, figure panel in parentheses. WT Veh: 12,055 mitochondria(m) from 24 cells(c) from 6 animals(a) (D); Efhd1hKO Veh: 17,876m 22c 3a(D); WT ATP: 19,498m 20c 4a(D); Efhd1hKO ATP: 10,734m 18c 3a(D). WT: 7(E and F), 14(H), 13(I); Efhd1hKO: 9(E and F), 7(H), 11(I). shCtrl-human: 5(J), 6(K); shEFHD1-human: 6(J), 4(K). shCtrl: 6(L and M), 5(O, P, and R), 15(Q), 14(S); shEfhd1-1: 5(L, O, P, and R), 10(M), 15(Q and S); shEfhd1-2: 6(L), 8(M), 5(O, P, and R), 15(Q and S). Bar: mean ± SEM.