AIM: To examine the expression of activin A, a member of the transforming growth factor (TGFbeta) superfamily, recently has been reported to be overexpressed in liver cirrhosis, in the course of carbon tetrachloride-i...AIM: To examine the expression of activin A, a member of the transforming growth factor (TGFbeta) superfamily, recently has been reported to be overexpressed in liver cirrhosis, in the course of carbon tetrachloride-induced rat hepatic fibrosis. METHODS: Hepatic fibrosis was induced in rats by subcutaneous injections of 40% carbon tetrachloride oily solution for a period of 1 to 7 weeks. At the end of 1, 2, 3, 4, 5, 6 and 7 weeks after carbon tetrachloride injections, the rats were killed in group (6-10 rats each time) for study. The activin A messenger RNA expression and its protein localization were assessed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: The normal rat liver expressed activin A mRNA and protein, and its expression was transiently decreased and became undetectable after carbon tetrachloride injections for 2 or 3 weeks and then increased gradually. After injection of carbon tetrachloride for 6 and 7 weeks, activin A mRNA and protein expressions were significantly enhanced in rat liver. Compared with that of the normal rat liver. Activin A mRNA expression levels in rats receiving carbon tetrachloride injections for 6 and 7 weeks were 1.6 and 2.2 times that of those in normal rat liver respectively (0.456 +/- 0.094 vs 0.2860.0670, P【 0.01; 0.620 +/- 0.134 vs 0.286 +/- 0670, P【 0.01). Immunohistochemistry showed that activin A expressed in hepatocytes of normal liver, and its expression was decreased in rats receiving carbon tetrachloride for 2 or 3 weeks. Compared with normal liver, activin A expression distribution mode changed in fibrotic liver, being increased significantly in hepatocytes around fibrotic areas. CONCLUSION: Activin A expression was increased in late stage of hepatic fibrosis, and this may be involved in hepatic fibrosis formation in this period.展开更多
The aims of the study were to determine the distribution of inhibin and its α subunit in some rat tissues by an immunohistochemical method of streptavidin-biotin complex （SABC） and to assess the transport mechanism...The aims of the study were to determine the distribution of inhibin and its α subunit in some rat tissues by an immunohistochemical method of streptavidin-biotin complex （SABC） and to assess the transport mechanism of inhibin by investigating the localization of inhibin and α subunits in the central nervous system （mainly in hypothalamus and pituitary） of ovariectomized rats. Investigations on the extragonadal tissues of ovariectomized rats showed positive expression of inhibin and its α subunit in heart, kidney, spleen, pancreatic gland cells, but no positive reaction sites were seen in lung, liver, submaxillary gland, and adrenal gland. After injection with inhibin α subunit fragment or inhibin extract, positive reaction sites were observed in hypothalamus and pituitary of ovariectomized rats by SABC. Inhibin and its subunit was present in a wide variety of nonreproductive organs and tissues, and its expression was tissue specific, which indicated that inhibin might play a role in regulating tissue function through autocrine/paracrine mechanisms. Inhibin dimer and α subunit could be transported through the BBB by the method of “separation and reconstruction”.展开更多
文摘AIM: To examine the expression of activin A, a member of the transforming growth factor (TGFbeta) superfamily, recently has been reported to be overexpressed in liver cirrhosis, in the course of carbon tetrachloride-induced rat hepatic fibrosis. METHODS: Hepatic fibrosis was induced in rats by subcutaneous injections of 40% carbon tetrachloride oily solution for a period of 1 to 7 weeks. At the end of 1, 2, 3, 4, 5, 6 and 7 weeks after carbon tetrachloride injections, the rats were killed in group (6-10 rats each time) for study. The activin A messenger RNA expression and its protein localization were assessed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: The normal rat liver expressed activin A mRNA and protein, and its expression was transiently decreased and became undetectable after carbon tetrachloride injections for 2 or 3 weeks and then increased gradually. After injection of carbon tetrachloride for 6 and 7 weeks, activin A mRNA and protein expressions were significantly enhanced in rat liver. Compared with that of the normal rat liver. Activin A mRNA expression levels in rats receiving carbon tetrachloride injections for 6 and 7 weeks were 1.6 and 2.2 times that of those in normal rat liver respectively (0.456 +/- 0.094 vs 0.2860.0670, P【 0.01; 0.620 +/- 0.134 vs 0.286 +/- 0670, P【 0.01). Immunohistochemistry showed that activin A expressed in hepatocytes of normal liver, and its expression was decreased in rats receiving carbon tetrachloride for 2 or 3 weeks. Compared with normal liver, activin A expression distribution mode changed in fibrotic liver, being increased significantly in hepatocytes around fibrotic areas. CONCLUSION: Activin A expression was increased in late stage of hepatic fibrosis, and this may be involved in hepatic fibrosis formation in this period.
文摘The aims of the study were to determine the distribution of inhibin and its α subunit in some rat tissues by an immunohistochemical method of streptavidin-biotin complex （SABC） and to assess the transport mechanism of inhibin by investigating the localization of inhibin and α subunits in the central nervous system （mainly in hypothalamus and pituitary） of ovariectomized rats. Investigations on the extragonadal tissues of ovariectomized rats showed positive expression of inhibin and its α subunit in heart, kidney, spleen, pancreatic gland cells, but no positive reaction sites were seen in lung, liver, submaxillary gland, and adrenal gland. After injection with inhibin α subunit fragment or inhibin extract, positive reaction sites were observed in hypothalamus and pituitary of ovariectomized rats by SABC. Inhibin and its subunit was present in a wide variety of nonreproductive organs and tissues, and its expression was tissue specific, which indicated that inhibin might play a role in regulating tissue function through autocrine/paracrine mechanisms. Inhibin dimer and α subunit could be transported through the BBB by the method of “separation and reconstruction”.
文摘将鸡催乳素 (PRL)和抑制素 - α亚基 (INB- α)基因编码序列重组为融合基因 ,制备了同时包含这 2种激素基因的融合蛋白。通过 PCR和分子克隆的方法首先将全部粤黄鸡 PRL成熟肽 c DNA克隆到载体 p RSET A的 Bgl 和 Eco R 克隆位点之间 ,获得重组质粒 p PRL- RSET。鸡 INB- α片段经扩增后分别被克隆到质粒 p RSET A和 p PRL- RSET的 Nhe 和 Xho 克隆位点之间 ,获得重组质粒 p INB- RSET和 p INB- PRL。以上重组质粒构建的正确性分别由各特定引物组合扩增的 PCR产物长度、特定限制性内切酶消化各重组质粒所得产物长度以及对各质粒的测序结果得到验证。重组质粒 p PRL- RSET和 p INB- PRL 转化 E.coli BL2 1(DE3)株 ,IPTG诱导后所表达的产物经 SDS- PAGE显示 ,其分别与所预期的重组蛋白分子大小相符。质粒 p PRL - RSET和 p INB- PRL的表达产物和用 Ni- NTA凝胶纯化的 2重组蛋白产物都可与抗鸡 PRL 抗体产生特异的免疫印迹 ,并且表达菌裂解液和相应纯化蛋白的免疫印迹处于同一位置。结果说明 ,试验已成功完成了鸡 PRL、INB-α及 2者融合蛋白的构建。
