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Objective:To study the signaling pathway of the up-regulation of claudin-5 expression by Xuebijing injection.Methods:Animal and cell models of acute respiratory distress syndrome (ARDS) were induced by lipopolysaccharide (LPS). ① In vivo study, 20 male Sprague-Dawley (SD) rats were randomly divided into 4 groups: control group, LPS group (LPS injection 10 mg/kg for 12 hours), Xuebijing control group (Xuebijing injection 1 mg/kg, twice a day, for 3 days), and Xuebijing intervention group (LPS injection after pretreatment of Xuebijing injection), according to random number method with 5 rats in each group. The lung tissues were taken to detect lung dry/wet weight ratio (W/D) and the morphological changes in each group. Claudin-5, phosphorylated forkhead box transcription factor O1 (p-FOXO1), total FOXO1 (t-FOXO1), phosphorylated Akt (p-Akt) and total Akt (t-Akt) in lung tissues were detected by immunohistochemical staining (IHC) and Western blotting. ② In vitro study, human pulmonary microvascular endothelial cells (HPMECs) were divided into 6 groups (5 holes in each group): control group, Xubijing control group (incubated with 2 g/L Xubijing for 24 hours), phosphoinositide 3-kinases (PI3K) signaling pathway LY294002 control group (incubated with 10 μmol/L LY294002 for 1 hour), LPS group (incubated with 1 mg/L LPS for 12 hours), Xubijing intervention group (incubated with 2 g/L Xuebijing for 24 hours, then with 1 mg/L LPS for 12 hours) and LY294002 intervention group (incubated with 10 μmol/L LY294002 for 1 hour, then with 2 g/L and Xubijing for 24 hours, and then with 1 mg/L LPS for 12 hours). The expression levels of claudin-5, p-FOXO1, t-FOXO1, p-Akt and t-Akt of HPMECs in each group were assessed by Western blotting. Results:In vivo study: ① Compared with the control group, the lung W/D ratio increased significantly in LPS group (6.79±0.42 vs. 4.19±0.13), and decreased significantly after the intervention of Xuebijing (4.92±0.38 vs. 6.79±0.42, P < 0.01). ② Morphological changes of lung tissue: compared with the control group, the injury of lung tissue in LPS group was more serious, which was significantly improved after Xuebijing intervention. ③ Expression levels of claudin-5, p-Akt/t-Akt and p-FOXO1/t-FOXO1: the expression levels of claudin-5, p-Akt/t-Akt and p-FOXO1/t-FOXO1 in LPS group were significantly decreased as compared with the control group (claudin-5/GAPDH: 0.33±0.03 vs. 1.03±0.07, p-Akt/t-Akt: 0.18±0.02 vs. 1.01±0.13, p-FOXO1/t-FOXO1: 0.16±0.06 vs. 1.00±0.19, all P < 0.01). After the intervention of Xuebijing, the expression levels were significantly increased as compared with the LPS group (claudin-5/GAPDH: 0.53±0.05 vs. 0.33±0.03, p-Akt/t-Akt: 0.56±0.12 vs. 0.18±0.02, p-FOXO1/t-FOXO1: 0.68±0.10 vs. 0.16±0.06, all P < 0.01). In vitro study: compared with the control group, the expression level of claudin-5 in the LPS group was significantly decreased (claudin-5/β-actin: 0.45±0.03 vs. 1.01±0.15, P < 0.01), and the expression level of claudin-5 in Xuebijing intervention group was also significantly decreased (claudin-5/β-actin: 0.80±0.08 vs. 1.01±0.15, P < 0.01). After the intervention of LY294002, the expression of claudin-5 was significantly decreased as compared with the Xubijing intervention group (claudin-5/β-actin: 0.41±0.02 vs. 0.80±0.08, P < 0.01). Conclusion:Xuebijing injection improve pulmonary vascular barrier function in rats with ARDS by up-regulating claudin-5 expression through PI3K/Akt/FOXO1 signaling pathway.
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Objective:To investigate the molecular mechanism of Buyang Huanwu Tang in improving cerebral vasospasm after subarachnoid hemorrhage. Method:Eighty male Sprague-Dawley rats were randomly divided into sham operation group, model group, Buyang Huanwu Tang low and high dose (13, 26 g·kg-1·d-1) group. According to 10 mL·kg-1, the drug was administered twice a day for 7 days. The subarachnoid hemorrhage model was made by double occipital pool injection method. The neurological function scores of rats in each group were evaluated at 1, 3, 5 and 7 days. The diameter of basilar artery was measured by hematoxylin-eosin (HE)staining. The expressions of phosphp-phosphoinositide 3-kinases(p-PI3K), phosphp-protein kinase B(p-Akt),endothelial nitric oxide synthase(eNOS) and neuronal nitric oxide synthase(nNOS) protein in basilar artery brain tissue were detected by Western blot. The expression of nitric oxide(NO) and endothelin-1(ET-1) in rat cerebrospinal fluid was detected by enzyme-linked immunosorbent assay (ELISA). Result:Compared with sham operation group, the neurological function scores of the model group were significantly decreased (PPPPP-1·d-1) increased the neurological function scores 3 to 5 days after treatment, and the basilar artery diameter was significant increased (PPPPPPPPPConclusion:The protective effect of Buyang Huanwu Tang on cerebral vasospasm after subarachnoid hemorrhage may be related to up-regulation of p-PI3K, p-Akt and eNOS expression in PI3K/Akt/eNOS signaling pathway, thereby increasing NO production.
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Background and purpose: Multidrug resistance (MDR) is the dominating obstacle to the chemotherapy. There is strong evidence that the phosphoinositide 3-kinases (PI3Ks) signaling pathway is involved in MDR phenotype, however, the mechanism of MDR occurrence is still unknown. This study tended to investigate the regulating effect of PI3K/Akt signaling pathway and its downstream target genes in P-glycoprotein (P-gp) (ABCB1 gene encoding)-mediated MDR in human colon carcinoma HCT-116/L-OHP cells. Methods:Pretreatment with PI3K selective inhibitor LY294002 (20μmol/L) for 2 h, the sensitivity of L-OHP was evaluated by the CCK-8 (cell counting kit-8) assay in HCT-116/L-OHP cells, and the expressions of P-gp, LRP, MRP-2, Akt, p-Akt, IκB and p-IκB were evaluated by Western blot. The activity of ABCB1 promoter was evaluated by chromatin immunoprecipitation analysis (CHIP). Results: After inhibiting the activity of PI3K/Akt signaling pathway, the IC50 value of L-OHP decreased from(157.48±16.73)μg/mL to (53.68±3.18)μg/mL in HCT-116/L-OHP cells, and the reversal index was 2.93 (P<0.01). The expressions of P-gp, p-Akt and p-IκB were down-regulation compared with the concrol group (P<0.01), but the expressions of LRP, MRP-2, Akt and IκB didn't change signiifcantly. CHIP result has conifrmed that NF-κB protein could bind to the region of ABCB1 gene promoter in HCT116/L-OHP cells. Conclusion:Blocking of PI3K/Akt/NF-kB signal pathway could increase the drug sensitivity to MDR cells, inhibit the phosphorylation of p-Akt and p-IκB, and reversing ABCB1/P-glycoprotein-mediated multidrug resistance in colon carcinoma cells.