ABSTRACT
Background: Expression of microRNA⁃320 (miR⁃320) is down regulated in acute pancreatitis, and the mechanism of its effect on acute pancreatitis is still unclear. Aims: To investigate the effect of miR⁃320 on intestinal injury in rats with acute pancreatitis and its mechanism. Methods: Rats were randomly divided into sham operation group, model group, miR⁃ 320 agonist group (agomir miR ⁃ 320 group), miR ⁃ 320 agonist control group (agomir NC group), JAK2 inhibitor group (AG490 group), and NF⁃κB pathway inhibitor group (PDTC group). The rat model of acute pancreatitis was established by retrograde injection of 5% sodium taurocholate to the bile duct. The automatic biochemical analyzer was used to detect serum levels of amylase and lipase; ELISA assay was used to detect serum levels of TNF⁃α and IL⁃1β; HE staining was used to observe the pathological changes of rat pancreas and ileum; TUNEL staining was used to observe cell apoptosis in rat ileum; real⁃time fluorescent quantitative PCR (RT⁃qPCR) was used to detect the expression of miR⁃320 in ileum tissue; Western blotting method was used to detect the expressions of JAK2/STAT3 and NF⁃κB signaling pathway related proteins in ileum. Results: Compared with sham operation group, the pancreas and ileum were severely injured in model group, and the pathological score and ileum cell apoptosis were significantly increased (P<0.05), serum levels of amylase, lipase, TNF⁃ α, and IL⁃1β were significantly increased (P<0.05), the expression of miR⁃320 in ileum tissue was significantly decreased (P<0.05), the ratios of p⁃JAK2/JAK2, p⁃STAT3/STAT3, p⁃p65/p65, and p⁃IκBα/IκBα in ileum tissue were significantly increased (P<0.05). Compared with model group, the pathological damages of pancreas and ileum in agomir miR ⁃ 320 group, AG490 group and PDTC group were reduced, and the pathological score and ileum cell apoptosis were significantly decreased (P<0.05), serum levels of amylase, lipase, TNF ⁃ α, and IL ⁃ 1β were significantly decreased (P<0.05), the expression of miR⁃320 in ileum tissue was significantly increased (P<0.05), the ratios of p⁃JAK2/JAK2, p⁃STAT3/STAT3, p⁃ p65/p65, and p⁃IκBα/IκBα in ileum tissue were significantly decreased (P<0.05). Conclusions: MiR⁃320 can improve the intestinal injury in rats with acute pancreatitis by inhibiting the activation of JAK2/STAT3 and NF⁃κB signaling pathways.
ABSTRACT
This study investigated the effects of telmisartan on insulin resistance in high-fat diet-treated rats and the possible mechanism. A total of 40 male Sprague-Dawley rats enrolled in the study were divided into 4 groups at random: ND group (n=10) and HD group (n=10), in which the rats were given a normal chow diet or a high-fat diet for 20 weeks following a one-week adaptation; ND+telmisartan (n=10) group and HD+telmisartan group (n=10), in which the rats were initially administered in the same way as the ND or HD group, and then they were orally gavaged with telmisartan (5 mg/kg daily) additionally for 5 weeks. Related inflammatory factors were measured by ELISA. Monocyte chemotactic protein 1 (MCP-1), phosphorylated JNK and IκB-α expressions in both adipose and liver were detected by Western blotting. CRP and angiotensin II receptor 1 (AT1) mRNA expressions in both adipose and liver were determined by RT-PCR. The results showed that telmisartan administration in vivo reversed insulin resistance as evidenced by a decrease in plasma fasting glucose levels, plasma fasting insulin levels and homeostasis model of assessment-insulin resistance (HOMA-IR). Furthermore, telmisartan administration significantly reduced serum CRP, TNF-α and IL-1β levels, and elevated serum IL-10 levels. It was also found to hamper the high-fat diet-induced increase in CRP mRNA, AT1 mRNA and MCP-1, and decrease in IκB-α in both adipose and liver. It was concluded that telmisartan administration in vivo may improve insulin resistance through attenuated inflammatory response pathways.