Histone deacetylase inhibitor suberoylanilide hydroxamic acid alleviates liver fibrosis by suppressing the transforming growth factor-β1 signal pathway
Yao Wanga , Lei Zhao b , Fang-Zhou Jiaoa , Wen-Bin Zhanga , Qian Chena , Zuo-Jiong Gonga,∗
a Department of Infectious Diseases, Renmin Hospital of Wuhan University, Wuhan 430060, China b Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China ∗ Corresponding author.
E-mail address: zjgong@163.com (Z.-J. Gong)
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.