ABSTRACT
Objective:To investigate the effect of miR-141 down-regulation on the damage of renal tubular epithelial cell, and further to explore its mechanism.Methods:The renal tubular epithelial cell line HK-2 cells were divided into normal (5.5 mmol/L D-glucose) group, hypertonic group, high glucose (30 mmol/L D-glucose) group, negative control+high glucose group (transfected with NC inhibitor vector) and si-miR-141+high glucose group (transfected with miR-141 inhibitor vector) . Real time quantitative polymerase chain reaction (qRT-PCR) was used to detect the relative expression of miR-141. The production of reactive oxygen species (ROS) , cell viability and apoptosis were detected by DCFH-DA fluorescence staining, CCK-8 method and flow cytometry. The expression of Sirt1/Nrf2 signaling pathway related proteins was detected by Western blot. Luciferase reporter gene assay verified the targeting relationship between miR-141 and Sirt1 mRNA.Results:①Compared with the normal group, after transfection with si-miR-141, the relative expression of miR-141 decreased (1.00±0.03 vs 0.52±0.06) , the difference was statistically significant ( F=278.104, P<0.05) ; ② Compared with the normal group [DCFH-DA fluorescence intensity (7.18±0.59) %], the high glucose group [DCFH-DA fluorescence intensity (84.95±3.21) %] cell ROS level was significantly increased, and compared with the high glucose group [DCFH-DA fluorescence intensity (84.95±3.21) %] Compared with the si-miR-141+ high glucose group [DCFH-DA fluorescence intensity (45.10±4.29) %] cell ROS levels were significantly reduced, the difference was statistically significant (all P<0.05) ; ③compared with the normal group (5.13%±0.78) % Compared with the hypertonic group (5.96±0.81) %, the high glucose group (32.76±2.95) % cell apoptosis rate was significantly increased, while the si-miR-141+ high glucose group (17.54%± 2.79) % apoptosis rate was significantly lower in the higher glucose group and the negative control+ high glucose group (33.40%±3.14) %, the difference was statistically significant ( F=221.419, P<0.05) ; ④compared with the normal group (100±3.98) % Compared with the hypertonic group (95.68±5.14) %, the high glucose group (67.24±5.18) % HK-2 cell survival rate was significantly reduced; at the same time, compared with the high glucose group (67.24±5.18) % and Compared with the negative control+ high glucose group (65.33±3.10) %, the si-miR-141+ high glucose group (83.55±5.10) % cell survival rate increased significantly, and the difference was statistically significant ( F=93.008, P<0.05) ; ⑤ Compared with the normal group and the hypertonic group, the expression of Cleaved Caspase 3 protein in the high glucose group increased, while the expression of Sirt1, Nrf2 and HO-1 protein was down-regulated; however, compared with the high glucose group, si- In the miR-141+ high glucose group, Cleaved caspase 3 protein expression decreased, while Sirt1, Nrf2 and HO-1 protein expression increased, the difference was statistically significant (all P<0.05) . Conclusions:Down-regulation of miR-141 can ameliorate high glucose-induced renal tubular epithelial cell damage induced oxidative stress by activating Sirt1/Nrf2 signaling pathway.
ABSTRACT
Objective: To explore the mechanisms of emodin in protecting intestinal mucosal barrier in rat with severe acute pancreatitis (SAP). Methods: Sixty SD rats were randomly divided into three groups: sham-operation group, untreated group, and emodin group. SAP in rats of the untreated group and the emodin group was induced by retrograde pumping of 3.0% sodium cholate to the common bile duct. Specimens were obtained 24 hours after the severe acute pancreatitis was induced. Serum level of leptin, serum activity of amylase and plasma content of endotoxin were measured. Ileum mucosa from ileocecal junction was observed by light microscopy and electron microscopy to measure pathological and ultrastructural changes. Apoptosis of ileum mucosal cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method, and expression of Bax in ileum mucosal cells was measured by immunohistochemical method. Results: Compared with the sham-operation group, there was significant increase in the levels of leptin, endotoxin, the activity of amylase, apoptosis index and Bax expression in the untreated group (P<0.01). Compared with the untreated group, the level of endotoxin, apoptotic index and Bax expression level in the emodin group were significantly reduced (P<0.01) and the leptin level was increased (P<0.05). More severe pathological changes appeared in the untreated group than in the sham-operation group under the light and electron microscopes; meanwhile less severe damage was observed in the emodin group as compared with the untreated group. Conclusion: Emodin can inhibit the apoptosis of intestinal mucosa cells and up-regulate the serum leptin content to protect the intestina1 barrier function and prevent the translocation of bacteria and endotoxin.
ABSTRACT
Objective To define the risk period of acute pancreafifis-associated lung injury (APALI) by aserial study including a dynamic changes in total water content of lung, ultrastructure and number of type Ⅱ alveo-lar epithelial, and reactive oxygen metabolisms (ROMs) of lung tissue in mice with severe acute pancreatits (SAP)and a clinical analysis of APALI patients. Method ICR mice were selected to establish SAP model. The animalsreceived 7 intraperitoneal injections of caerulein (50 μg/kg body weight) at hourly intervals followed by intraperi-toueal injection of lipopolysaccharide (15 mg/kg body weight). The total water content, uhrastrueture and numberof type Ⅱ alveolar epithelial cells, and ROMs of lung tissue were detected before (0 h) and 6 hours, 12 hours,lday, 4 days and 7 days after SAP model establishment, respectively. In addition, 215 patients with APALI (PaO2< 60 mmHg) collected from the First Affiliated Hospital of Zhejiaug University between January 1998 and Decem-ber 2006 were analyzed. Statistical analysis were performed by using F-test. P-values less than 0.05 were regardedas statistically significant. Results The total water content and ultrastructure mitochondria and lamellar bodies intype Ⅱ alveolar epithelial cells of lung in SAP mice were significantly altered at 12 hours after SAP model estab-lishment, and reached maximum at 1 to 4 days later. A decrease in number of type Ⅱ alveolar epithelial cells andincrease in ROMs reached a maximum at 1 day after SAP model establishment. Furthermore, the results of clinicalstudy showed that the lung injury occurred at (3.1435±1.0199) days after SAP. The data were almost consistentwith the resalts from SAP model. Conclusions The risk period of APALI occurres between the 1st day and the4th day during the course of SAP.