The Experimental Study Of 2-Ml For The Treatment Of Liver Arterial Hypoxia Induced Hepatic Fibrosis In Rats

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with an annual incidence rate of about 600,000 cases, and the incidence and death of HCC are still on an upward trend. HCC incidence and deaths of China account for more than half of those of the world. Most of HCCs in China are developed on the basis of the chronic liver diseases-liver cirrhosis. However, there are no obvious symptoms and signs in the initial stage of HCC and most HCC patients have missed radical treatment (such as surgery) at the time of HCC diagnoses. Transarterial embolization (TAE) is one preferred non-surgical interventional treatment, the principle of which is blocking the blood supply of liver tumors, causing tumor necrosis, while giving chemotherapy drugs or radioactive seed implantation of the integrated Treatment. Because of the complexity of HCC tumor tissue blood supply, it is difficult to avoid embolization of normal liver tissues, leading to the hypoxic injury of this part normal liver tissue, aggravating the existing degree of hepatic fibrosis, presenting the complications of liver decompensation, and affecting the prostecdtive efficacy of TAE in HCC patients.Various factors are involved in the initiation of liver injury-repair process, including the activation of hepatic stellate cells (HSC) and the imbalance of liver extracellular matrix metabolism. TAE treatment is based on causing tissue hypoxia to kill tumor cells, and hypoxia also led to embolization of non-tumor liver tissue injury of the key factors. Hypoxia inducible factor 1 (HIF-1) is one transcription factor during hypoxia and plays an important role in hypoxic injury of liver. HIF-1 can promote fibrosis through a variety of factors transform HSC to myofibroblasts, promote the synthesis of ECM, and inhibit its degradation, and therefore lead to the formation of liver fibrosis. However, it is lack of liver fibrosis treatment against hypoxia and HIF-1. 2-methoxyestradiol (2-ME2), an estrogen metabolite, can inhibit the post-transcriptional level of HIF-1, and become a hot spot in research of cancer treatment. According to the role of 2-ME2 in inhibition of HIF-1 activity, our study made use of hepatic artery ligation (HAL) to simulate clinical TAE treatment of hepatic artery by ischemia and hypoxia, and to explore the role of 2-ME2 in hypoxia-induced liver fibrosis.Purpose: The rat model of liver fibrosis induced by HAL was established to explore the inhibit effect of 2-ME2 in hypoxia-induced liver fibrosis and its molecular mechanism.Methods: 30 male Sprague Dawley (SD) rats were randomly divided into control group, HAL group and 2-ME2 groups of 10 each in our study. Rats in control group were given sham operation, rats in HAL+ placebo group were given intraperitoneal injection of placebo, and rats in HAL+ 2-ME2 group were given intraperitoneal injection of 2-ME2 daily medication 5mg/kg after HAL operation. 14 days later, all experimental rats were killed to obtain liver tissues and to make paraffin embedded sections, and then fibrosis was evaluated by hematoxylin-eosin (H-E) staining and Sirius red - picric acid staining. Collagen tissue was assessed by alkaline hydrolysis of hepatic hydroxyproline (HYP) content. HIF-1αandα-smooth muscle actin (α-SMA) was detected by immunohistochemical staining (IHC) to study the effects of 2-ME2 on HIF-1αexpression and HSC activation.Results: H-E and Sirius red - picric acid staining showed that there were lots of degeneration, necrosis and fibrosis in HAL+ placebo group, liver fibrosis level of which was significantly higher than that of the control group (P < 0.05); The degrees of liver destruction, collagen deposition and liver fibrosis were significantly reduced in HAL+2-ME2 group compared to HAL+ placebo group (P < 0.05). HYP content in liver tissue was significantly lower in HAL+2-ME2 group compared to HAL+ placebo group (P < 0.05), but higher than in control group (P < 0.05). The expressions of HIF-1αandα-SMA were up-regulated in HAL+ placebo group but both of the two were significantly decreased in HAL+2-ME2 group (P < 0.05).Conclusion: 2-ME2 treatment could reduce HIF-1αexpression, HSC activation, collagen content of liver and liver fibrosis induced by hypoxia.