FIG. 7.

Hepatic silencing of GPR55 ameliorates NASH induced by an MCD diet and fibrosis induced by CCl₄ in mice. C57BL/6J mice randomly received a TVI with Lentiv‐shGPR55 or Lentiv‐sh scrambled and 4 weeks later were fed an MCD diet for 4 weeks (n = 7). (A) Serum levels of AST. (B) H&E staining (first panel), Oil Red O staining (second panel), Sirius Red staining (third panel), and F4/80‐immunohistochemistry staining (fourth panel) of liver sections. Staining areas were quantified. (C) Triglyceride content; levels of hydroxyproline; protein levels of pAMPKα, pACC, and ACC; levels of malonyl‐CoA; and mRNA levels of fibrosis markers in the liver. C57BL/6J mice were treated with CCl₄ (0.6 mL/kg administered i.p.) or vehicle once a week for 6 weeks, receiving a TVI with Lentiv‐shGPR55 or Lentiv‐sh scrambled during the first week. (D) GPR55 mRNA levels in the liver and serum levels of AST (n = 8). (E) H&E staining (upper panel) and Sirius Red staining (lower panel) of liver sections. Collagen deposition was quantified in the Sirius Red staining sections (n = 8). (F) Protein levels of pAMPKα, pACC, and ACC and mRNA levels of fibrosis markers in the liver (n = 4‐8). HPRT and GAPDH were used to normalize mRNA and protein levels, respectively. Dividing lines indicate splicing in the same gel. Data are presented as mean ± SEM. Statistical differences are denoted by *P < 0.05, **P < 0.01, and ***P < 0.001. Abbreviations: ACC, acetyl‐CoA carboxylase; AST, aspartate aminotransferase; CoA, coenzyme A; GAPDH, glyceraldehyde 3‐phosphate dehydrogenase; GPR55, G protein–coupled receptor 55; H&E, hematoxylin and eosin; HPRT, hypoxanthine‐guanine phosphoribosyltransferase; i.p., intraperitoneally; Lentiv‐shGPR55, lentiviral vector encoding short hairpin RNA against GPR55; Lentiv‐sh scrambled, lentiviral vector encoding scrambled short hairpin RNA; MCD, methionine‐choline–deficient; NASH, nonalcoholic steatohepatitis; pACC, phosphorylated ACC; pAMPKα, phosphorylated adenosine monophosphate–activated protein kinase α; shCTL, short hairpin RNA control; shGPR55, short hairpin RNA against GPR55; sh scrambled, scrambled short hairpin RNA; TVI, tail‐vein injection.