leptin and tetramethylpyrazine

Micro-RNAs (miRNAs) are involved in regulation of the incidence and development of several hepatic diseases. Thus manipulating miRNAs may be a promising therapeutic strategy against these entities. In this study hepatic stellate cells (HSCs) were transfected with hsa-miR-9 or anti-hsa-miR-9, treated with tetramethylpyrazine (TMP), or subjected to treatment with TMP and hsa-miR-9 transfection (combined treatment group). Then, real-time polymerase chain reaction (PCR) was performed to measure mRNA levels of hsa-miR-9. Expression of hsa-miR-9 was highest in the combination treatment group compared with other groups, and significantly higher than TMP-treated and hsa-miR-9-transfected groups (both p<0.05). The anti-hsa-miR-9-transfected group expressed the lowest mRNA level of hsa-miR-9 with marked decrease versus control (p<0.05). Downstream factors that may be affected by miR-9 such as leptin, α-smooth muscle actin (SMA), and collagen I, as well as phosphorylation levels of Janus kinase 1 (JAK1)/signal transducer and activator of transcription 3 (STAT3) were investigated at the protein level. All these factors were regulated contrariwise to expression trends of hsa-miR-9, showing the lowest level in the combination treatment group and highest level in anti-hsa-miR-9-transfected group. These results suggest that both transfection of hsa-miR-9 and TMP can lead to upregulated endogenous expression of hsa-miR-9, inhibit activation of JAK1/STAT3 signal pathway induced by leptin, and lead to reduction of α-SMA and collagen I-thus impeding activation of HSC.

Topics: Actins; Collagen Type I; Gene Expression Regulation; Hepatic Stellate Cells; Humans; Janus Kinase 1; Leptin; Ligusticum; Liver Cirrhosis; MicroRNAs; Phosphorylation; Phytotherapy; Plant Extracts; Pyrazines; Real-Time Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; STAT3 Transcription Factor; Transfection; Up-Regulation

This study was conducted to investigate the effect of tetramethylpyrazine (TMP) on CCl(4)-induced fibrosis in rats and the possible roles of leptin, TGF-beta1, Smad3, and Smad7 in this process. Liver fibrosis in rats was induced by the subcutaneous injection of 60% CCl(4) (0.3 mL /100 g body weight, biweekly ) for 12 weeks. Rats in TMP prevention and treatment groups were given TMP (10 mg /100 g body weight, daily) by gavage from days 1 and 31 after the start of CCl(4) injection, respectively. The mRNA expression of leptin, OB-Rb, TGF-beta1, and TGF-beta RII in the liver were detected by RT-PCR, whereas Smad3 and Smad7 protein were determined by Western blot. The results showed that hepatic cirrhosis was obviously alleviated in both TMP prevention and treatment groups. The mRNA expression of leptin, OB-Rb, TGF-beta1 and -beta RII, and Smad3 protein were higher in the cirrhotic models. In TMP prevention and treatment groups, these markers of expression were higher, compared with that of the normal control, but were lower when compared with that of the cirrhotic model group. Smad7 protein expression was lower in the cirrhotic model group than in the normal control. Smad7 expression in TMP prevention and treatment groups was higher, compared with that in the cirrhotic model group. Liver collagen in the TMP prevention group was the lowest among all CCl(4) injection groups. In conclusion, TMP can prevent and alleviate the development of liver fibrosis in rats. The possible mechanism could involve the downregulation of leptin, Ob-Rb, TGF-beta1, TGF-beta RII, and Samd3, and upregulation of Smad7.

Topics: Animals; Blotting, Western; Carbon Tetrachloride; Down-Regulation; Fibrinolytic Agents; Histocytochemistry; Leptin; Liver Cirrhosis; Male; Pyrazines; Random Allocation; Rats; Rats, Sprague-Dawley; Receptors, Leptin; Receptors, Transforming Growth Factor beta; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Smad3 Protein; Smad7 Protein; Transforming Growth Factor beta1