Histone deacetylase inhibitor suberoylanilide hydroxamic acid alleviates liver fibrosis by suppressing the transforming growth factor-β1 signal pathway

Hepatobiliary Pancreat Dis Int. 2018 Oct;17(5):423-429. doi: 10.1016/j.hbpd.2018.09.013. Epub 2018 Sep 15.

Abstract

Background: Histone deacetylases (HDACs) inhibitors are new anti-fibrotic drugs that inhibit the activity of hepatic stellate cells. The present study focused on the anti-fibrotic function of HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) by suppressing transforming growth factor-β1 (TGF-β1) signaling.

Methods: Male Sprague-Dawley rats were used to induce liver fibrosis with carbon tetrachloride (CCl4) and LX2 cell (human hepatic stellate cell line) was stimulated by TGF-β1. Both animals and cells were treated with SAHA. The Smad7 and connective tissue growth factor (CTGF) mRNA levels were detected by real-time polymerase chain reaction (PCR). Western blotting was used to examine the protein levels of CTGF, Histone H3 (H3), Smad7, Smad2/3, Acetyl-Histone H3 (AH3), HDAC2, α-smooth muscle actin (α-SMA), HDAC6, p-Smad2/3 and HDAC8. In addition, the TGF-β1 and liver enzyme levels from rat serum were detected. Histopathological changes were examined by hematoxylin and eosin (HE), Sirius red and Masson trichrome staining. The α-SMA expression was detected by immumohistochemical staining.

Results: Compared with control group, the TGF-β1 and liver enzyme levels from rat serum, together with the mRNA levels of CTGF and protein levels of CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were elevated in fibrotic rats (P < 0.01). But the Smad7 mRNA and AH3 protein levels were notably suppressed in the fibrotic rats (P < 0.01). Pathological examination showed the typical changes of liver fibrosis in the fibrotic rats. After the treatment with SAHA, the levels of liver enzymes, TGF-β1, CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were reduced (P < 0.01) and Smad7 and AH3 protein contents were elevated in liver fibrotic rats (P < 0.01). Moreover, immumohistochemistry showed that SAHA significantly suppressed the α-SMA protein content in fibrotic liver (P < 0.01).

Conclusion: The HDAC inhibitor SAHA alleviated liver fibrosis by suppressing the TGF-β1 signaling.

Keywords: Acetylation; Liver fibrosis; Suberoylanilide hydroxamic acid; Transforming growth factor-β1.

MeSH terms

  • Analysis of Variance
  • Animals
  • Biopsy, Needle
  • Blotting, Western
  • Disease Models, Animal
  • Histone Deacetylase Inhibitors / pharmacology*
  • Immunohistochemistry
  • Liver Cirrhosis / chemically induced
  • Liver Cirrhosis / drug therapy*
  • Liver Cirrhosis / pathology*
  • Male
  • Molecular Targeted Therapy / methods
  • Random Allocation
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects*
  • Smad Proteins / metabolism
  • Transforming Growth Factor beta1 / drug effects*
  • Vorinostat / pharmacology

Substances

  • Histone Deacetylase Inhibitors
  • Smad Proteins
  • Transforming Growth Factor beta1
  • Vorinostat