1. Anti-fibrotic effects of thalidomide on hepatic stellate cells and dimethylnitrosamine-intoxicated rats
- Author
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Yi-Tsau Huang, Yi-Chao Hsu, Yung-Tsung Chiu, Lee-Won Chong, and Kuo-Ching Yang
- Subjects
medicine.medical_specialty ,Cirrhosis ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Liver Cirrhosis, Experimental ,Dimethylnitrosamine ,Transforming Growth Factor beta1 ,NF-KappaB Inhibitor alpha ,In vivo ,Fibrosis ,Transforming Growth Factor beta ,Internal medicine ,Medicine ,Animals ,Pharmacology (medical) ,Molecular Biology ,Liver injury ,business.industry ,Tumor Necrosis Factor-alpha ,Biochemistry (medical) ,NF-kappa B ,Muscle, Smooth ,Cell Biology ,General Medicine ,medicine.disease ,Actins ,Rats ,Thalidomide ,Endocrinology ,Liver ,Hepatic stellate cell ,Tumor necrosis factor alpha ,I-kappa B Proteins ,Collagen ,business ,Hepatic fibrosis ,Immunosuppressive Agents ,medicine.drug - Abstract
Tumor necrosis factor-alpha (TNF-alpha) plays a central role in cellular necrosis, apoptosis, organ failure, tissue damage, inflammation and fibrosis. These processes, occurring in liver injury, may lead to cirrhosis. Thalidomide, alpha-N-phthalidoglutarimide, (C(13)H(10)N(2))(4), has been shown to have immunomodulatory and anti-inflammatory properties, possibly mediated through its anti-TNF-alpha effect. In this study, we investigated the in vitro and in vivo effects of thalidomide on hepatic fibrosis. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with transforming growth factor-beta1 (TGF-beta1) or TNF-alpha. The inhibitory effects of thalidomide on the NFkappaB signaling cascade and fibrosis markers including alpha-smooth muscle actin (alpha-SMA) and collagen, were assessed. An in vivo therapeutic study was conducted in dimethylnitrosamine (DMN)-treated rats, which were randomly assigned to 1 of 4 groups: vehicle (0.7% carboxyl methyl cellulose, CMC), thalidomide (40 mg/kg), thalidomide (200 mg/kg), or silymarin (50 mg/kg), each given by gavage twice daily for 3 weeks starting after 1 week of DMN administration. Thalidomide (100-800 nM) concentration-dependently inhibited NFkappaB transcriptional activity induced by TNF-alpha, including IKKalpha expression and IkappaBalpha phosphorylation in HSC-T6 cells. In addition, thalidomide also suppressed TGF-beta1-induced alpha-SMA expression and collagen deposition in HSC-T6 cells. Fibrosis scores of livers from DMN-treated rats receiving high dose of thalidomide (0.89 +/- 0.20) were significantly reduced in comparison with those of DMN-treated rats receiving vehicle (1.56 +/- 0.18). Hepatic collagen contents of DMN rats were also significantly reduced by either thalidomide or silymarin treatment. Immunohistochemical double staining results showed that alpha-SMA- and NFkappaB-positive cells were decreased in the livers from DMN rats receiving either thalidomide or silymarin treatment. In addition, real-time PCR analysis indicated that hepatic mRNA expressions of TGF-beta1, alpha-SMA, collagen 1alpha2, TNF-alpha and iNOS genes were attenuated by thalidomide treatment. In conclusion, our results showed that thalidomide inhibited activation of HSC-T6 cells by TNF-alpha and ameliorated liver fibrosis in DMN-intoxicated rats.
- Published
- 2005