Primary study on the mechanism of ductus arteriosus closure in rats: impact of aging pathway / 中华心血管病杂志

Objective: To explore the role and mechanism of aging pathway in patent ductus arteriosus closure of rats. Methods: Thirty outbreeding Sprague Dawley rats(20 females, 10-15 weeks old, 270-330 g) underwent random mating and conception. The primary Ductus Arteriosus smooth muscle cells (DASMCs) of pregnant 19 days(E19 group), 21 days(E21 group) and newborn(Day0 group) fetus were extracted and cultured. mRNA expression of cell senescence related markers p16, 21 and 53 genes in each group were detected by real-time fluorescent quantitative PCR(RT-PCR) after 48 hours culture. After hypoxic culture on DASMCs for 3 days, the DASMCs were divided into 3 groups: hypoxic control group(G0 group), 3 hours normal oxygen concentration treatment group(G3 group) and 6 hours normal oxygen concentration treatment group(G6 group). After intervention, mRNA expression of p16, 21 and 53 RT-PCR was detected. The DASMCs of newborn rats(Day0 group) were extracted and divided into 3 groups:low-oxygen culture control group, low-oxygen+siRNA culture group and normal oxygen concentration culture group. The DASMCs migration ability was tested experimentally by Transwell method. Result: The mRNA levels of p16, 21 and 53 in DASMCs were higher in E19 group than in Day0 group(all P<0.01), and the mRNA levels of p16, 21 and 53 in DASMCs were also higher in E21 group than those in Day0 group (all P<0.01). The mRNA levels of p16, 21 and 53 in DASMC were all higher in G0 group than those in G3 group (P<0.05 or 0.01), and the mRNA levels of p16, 21 and 53 in DASMCs were all higher in G0 group than those in G6 group (all P<0.01), and the mRNA levels of p16, 21 and 53 in DASMCs were all higher in G3 group than those in G6 group (all P<0.05). DASMCs migration ability of newborn rats was higher in normal oxygen concentration culture group than that in low-oxygen culture group (P<0.01), and DASMCs migration ability of newborn rats was also higher in low-oxygen+siRNA culture group than that in low-oxygen culture group (P<0.01). Conclusion: The expression of senescence marker of DASMCs decreases with the birth in rats during the process of ductal closure, and the aging pathway may affect ductal closure by inhibiting DASMCs migration in rats.

The effect of RNA interfering TLR4 signal pathway on phagocytosis of Kupffer cells / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the effect of RNA interfering TLR4 signal pathway on phagocytosis of Kupffer cells.</p><p><b>METHODS</b>RAW2647 mice mononuclear macrophage leukemia cells were observed. The tested group was interfered by Tlr4-mus-1567 RNA which had the best result confirmed by QPCR, cells interfered by Negative Control RNA as NC group, and normal cell as control. We perform the phagocytosis test on each group.</p><p><b>RESULTS</b>The tested group has lower phagocytes percentage than control (17.67% +/- 3.51% vs 32.00% +/- 3.00%, P < 0.01), and lower phagocytic index (46.33% +/- 7.51% vs 82.00% +/- 6.08%, P < 0.01).</p><p><b>CONCLUSIONS</b>Decreased phagocytic activity was observed on Kupffer cells by RNA interference.</p>

Activation of Kupffer cell and related signal pathway proteins in the liver of high fat and high fructose diet induced NAFLD mice / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the expression of F4/80, NF-kappaB, p-AKT, AKT in the liver of nonalcoholic fatty liver disease (NAFLD) mice. To determine the role of Kupffer cells (KCs) in the development of NASH (non-alcoholic steatohepatitis), and understand the pathogenic mechanism of NASH.</p><p><b>METHODS</b>Five C3H/HeN mice fed with normal diet were served as controls, while fifteen fed with high fat, high fructose, high fat combined fructose diet respectively for 16 weeks were as NAFLD mice models. The liver inflammation and hepatic damage were examined, and the expression of F4/80, NF-Kb, p-AKT, AKT and the content of lipid in the liver were also detected.</p><p><b>RESULTS</b>Chronic intake of high fat and 30% fructose solution caused a significant increase in hepatic steatosis in animals in comparison to water controls. Liver F4/80 and NF-kappaB were significantly higher in high fat and high fat combined fructose diet fed mice than that in controls (P < 0.01, P < 0.01), F4/80 protein were higher in high fat diet treated mice than those in fructose and high fat combined fructose groups (P < 0.01, P < 0.01). Markers of insulin resistance (e. g, hepatic phospho-AKT, AKT) were only altered in fructose-fed or high fat combined fructose animals (P < 0.01, P < 0.01).</p><p><b>CONCLUSION</b>High fat and fructose diet may induce NAFLD in C3H/HeN mice. Kupffer cells and signal pathway proteins were activated, and they may play key roles in the initiation and progression of NASH.</p>