[Down-regulation of HMGB1 expression ameliorates the progression of COPD in mice by inhibiting inflammatory response and epithelial mesenchymal transition].

Objective To explore the effect of down-regulation of high mobility group box 1 (HMGB1) expression on inflammatory response and epithelial mesenchymal transition (EMT) in the lung tissue of mice with chronic obstructive pulmonary disease (COPD) and its related mechanism. Methods The COPD model was induced by cigarette smoking, and HMGB1 expression in lung tissue of mice was down-regulated by small interfering RNA (siRNA). The mice were divided into negative control group (NC group), COPD group, si-NC intervention COPD group, si-HMGB1 intervention COPD group, and tiotropium bromide intervention COPD group (positive control group). After 4 weeks of cigarette smoking induction, the general condition of mice were observed, and the body mass changes of each group were recorded every week. HE staining was used to observe the pathological changes of lung tissue in each group. The expression of HMGB1 mRNA and protein in lung tissues of mice weredetected by real time quantitative PCR and Western blot analysis. The BALF of mice in each group was collected, and the levels of IL-6, TNF-α, IL-1ß and TGF-ß1 in BALF were detected by ELISA. The expressions of E-cadherin and α-SMA in lung tissues of mice were observed by immunohistochemical staining. The expression of RAGE, TLR4, TGF-ß1 and the phosphorylation of NF-κB p65 in lung tissues were detected by Western blot analysis. Results COPD mouse model induced by cigarette smoking was successfully established. Compared with COPD group, down-regulation of HMGB1 expression in lung tissue significantly improved the general vital signs of mice, promoted the increase of body mass, and improved the pathological damage of lung tissue in mice. Compared with the control group, HMGB1 mRNA and protein expression levels increased significantly in COPD group, COPD combined with si-NC group and COPD combined with tiotropium group, while no significant HMGB1 expression was detected in COPD combined with si-HMGB1 group. Compared with the control group, the secretion levels of IL-6, TNF-α, IL-1ß, TGF-ß1 in BALF, the expression levels of α-SMA, RAGE, TLR4, TGF-ß1 and the phosphorylation level of NF-κB p65 in lung tissues were significantly increased in COPD model group, while the expression level of E-cadherin significantly decreased. Compared with the COPD group or the COPD combined with si-NC group, the changes of the above indexes in the lung tissue of mice in the COPD combined with si-HMGB1 group and the COPD combined with tiotropium group dropped markedly, and no significant difference between the latter two groups was found. Conclusion Downregulation of HMGB1 expression in lung tissue of mice can reduce pulmonary inflammatory response and EMT by inhibiting NF-κB pathway, thus ameliorating the progression of cigarette smoke-induced COPD disease.

Regulatory Effect of 1,25(OH)2D3 on TGF-ß1 and miR-130b Expression in Streptozotocin-Induced Diabetic Nephropathy in Rats.

OBJECTIVE: To investigate the role of microRNA-130b in 1,25(OH)2D3 mediated improvement of renal fibrosis via transforming growth factor-beta 1 in a rat model of diabetic nephropathy (DN). METHODS: DN was induced in 30 rats by intraperitoneal injection of streptozotocin. These rats were randomly allocated to the DN group, TGF-ß1 overexpression group (in situ injection of TGF-ß1 lentivirus to kidney tissues), and TGF-ß1 siRNA group (in situ injection of TGF-ß1 siRNA lentivirus to kidney tissues). Rats with different expression levels of TGF-ß1 were administered 1,25(OH)2D3 (0.03 µg/kg/d) or peanut oil as control. DN rats were treated only with peanut oil. All rats were randomly divided into five groups (n = 6 per group): TGF-ß1 overexpression + oil, TGF-ß1 overexpression + 1,25(OH)2D3, TGF-ß1 siRNA + oil, TGF-ß1 siRNA + 1,25(OH)2D3, and DN + oil groups. After 37 days, kidney samples were collected and the expression of TGF-ß1 and miR-130b was determined by real-time PCR, western blotting, and immunohistochemistry. Hematoxylin and eosin staining and Masson staining were used to evaluate kidney morphological and fibrogenic changes. Differences were determined using ANOVA and Student's t-test. RESULTS: RT-PCR, western blotting, and immunohistochemistry revealed that interference of TGF-ß1 significantly decreased mRNA and protein levels of TGF-ß1 in renal tissues of DN rats compared to those in renal tissues of rats overexpressing TGF-ß1 (p < 0.05). Histological analysis showed that upregulated TGF-ß1 led to disorganized kidney structure and severe kidney fibrosis. The expression of miR-130b was significantly lowered upon lentivirus-mediated overexpression of TGF-ß1 than upon downregulation of TGF-ß1 (p < 0.05). Treatment with 1,25(OH)2D3 led to a significant reduction of TGF-ß1 at the mRNA and protein levels (both p < 0.05), improvement of renal structure and fibrosis, and an increase in miR-130b expression (p < 0.05). CONCLUSION: TGF-ß1 can decrease the expression of miR-130b in kidney tissues of DN rats. Moreover, miR-130b may be involved in the protective effect of 1,25(OH)2D3 on renal fibrosis via TGF-ß1.