IL-17A inhibits the degradation of RANKL in osteoblasts by inhibiting BCL2-Beclin1-autophagy signaling.

The inflammatory cytokine IL-17A is known to have the capacity to promote osteoclastogenesis, thereby enhancing bone loss. Moreover, IL-17A can promote the expression of RANKL in osteoblasts, contributing to its pro-osteoclastogenic effect. IL-17A is an autophagy regulator, which is also responsible for its regulation on RANKL expression. However, the specific role of autophagy in IL-17A-regulated RANKL expression and the underlying mechanism of IL-17A-regulated osteoblast autophagy remain unclear. IL-17A is known to inhibit autophagy by preventing BCL2 degradation. This study aimed to explore the significance of BCL2-dependent autophagy in IL-17A-regulated RANKL expression. Our results showed that IL-17A at 50 ng/mL could inhibit autophagic activity and promote RANKL protein expression in MC3T3-E1 osteoblast line. Moreover, the corresponding concentration of IL-17A could enhance BCL2 protein expression and the protein interaction between BCL2 and Beclin1 in MC3T3-E1 cells. However, the protein expression of RANKL and BCL2 promoted by 50 ng/mL of IL-17A was blocked by autophagy activation with Beclin1 pharmacological upregulation. Furthermore, RANKL protein expression promoted by 50 ng/mL of IL-17A was also reversed by autophagy activation with BCL2 knockdown. Importantly, the supernatant from osteoblasts treated with 50 ng/mL of IL-17A made osteoclast precursors (OCPs) form larger osteoclasts, which was reversed by BCL2 knockdown in osteoblasts. In conclusion, high levels of IL-17A prevent the degradation of RANKL by inhibiting BCL2-Beclin1-autophagy activation signal transduction in osteoblasts, thereby indirectly promoting osteoclastogenesis.

[Effects of silence information regulator 7 on proliferation and apoptosis of mouse renal podocytes under high glucose environment].

Objective: To investigate the effects and its mechanisms of silence information regulator 7(SIRT7)on mouse renal podocytes proliferation and apoptosis under high glucose environment. Methods: Mouse renal podocytes cultured with high glucose and treated with different methods were divided into the following groups:control group(Control),high glucose group(HG),high glucose+transfecting with SIRT7 overexpression vetor(pcDNA3.1-SIRT7) group(SIRT7 OE+HG),high glucose+transfecting with the negative control vetor(pcDNA3.1)group(SIRT7 OE-NC+HG),high glucose+transfecting with small interfering RNA-SIRT7 (siRNA-SIRT7) group (siRNA-SIRT7+HG), high glucose+ transfecting with siRNA-SIRT7 control group (siRNA-SIRT7-NC+ HG). Viability of proliferation was examined by CCK-8 method.Rate of apoptosis was detected by flow cytometry. The level of SIRT7 mRNA expression was measured by qRT-PCR. Western blot was performed to detect the protein expression of Nephrin and key factors of Wnt/ß-catenin signaling pathway. Results: The CCK-8 result showed that,compared with control group, the proliferative activity of mouse renal podocytes in HG group was decreased (P＜0.05). After transfected with SIRT7 overexpression vetor or small interfering RNA-SIRT7,compared to HG group,the cell proliferation activity was further decreased in siRNA-SIRT7 group(P＜0.05),but it was enhanced in SIRT7 OE+HG group (P＜0.05). The results of flow cytometry showed that compared with the control group, the apoptosis rate of cells in the HG group was increased (P＜0.05). Compared with the HG group, the apoptosis rate of cells in the siRNA SIRT7+HG group was increased significantly(P＜0.05), while that in the SIRT7 OE+HG group was decreased (P＜0.05). Compared with control group,the expressions of Nephrin, Wnt5a and ß-catenin were inhibited in HG group (P＜0.05). compared to HG group,siRNA-SIRT7 could down-regulate the expression levels of Nephrin, Wnt5a and ß-catenin in siRNA-SIRT7 group (P＜0.05), SIRT7 overexpression could up-regulate the expression levels of Nephrin, Wnt5a and ß-catenin in SIRT7 OE+HG group (P＜0.05). Conclusion: The findings suggest that high glucose environment is an important factor to inhibit the proliferation and induce apoptosis of mouse renal podocytes.Overexpression of SIRT7 can reverse the effects by activating Wnt/ß-catenin signaling pathway and up-regulating ß-catenin expression.

Prognostic Model to Predict Overall Survival for Metastatic Non-Small Cell Lung Cancer Patients Treated With Chemotherapy Combined With Concurrent Radiation Therapy to the Primary Tumor: Analysis From Two Prospective Studies.

PURPOSE: The role of radiotherapy, in addition to chemotherapy, has not been thoroughly determined in metastatic non-small cell lung cancer (NSCLC). The purpose of the study was to investigate the prognostic factors and to establish a model for the prediction of overall survival (OS) in metastatic NSCLC patients who received chemotherapy combined with the radiation therapy to the primary tumor. METHODS: The study retrospectively reviewed 243 patients with metastatic NSCLC in two prospective studies. A prognostic model was established based on the results of the Cox regression analysis. RESULTS: Multivariate analysis showed that being male, Karnofsky Performance Status score < 80, the number of chemotherapy cycles <4, hemoglobin level ≤120 g/L, the count of neutrophils greater than 5.8 ×109/L, and the count of platelets greater than 220 ×109/L independently predicted worse OS. According to the number of risk factors, patients were further divided into one of three risk groups: those having ≤ 2 risk factors were scored as the low-risk group, those having 3 risk factors were scored as the moderate-risk group, and those having ≥ 4 risk factors were scored as the high-risk group. In the low-risk group, 1-year OS is 67.7%, 2-year OS is 32.1%, and 3-year OS is 19.3%; in the moderate-risk group, 1-year OS is 59.6%, 2-year OS is 18.0%, and 3-year OS is 7.9%; the corresponding OS rates for the high-risk group were 26.2%, 7.9%, and 0% (P<0.001) respectively. CONCLUSION: Metastatic NSCLC patients treated with chemotherapy in combination with thoracic radiation may be classified as low-risk, moderate-risk, or high-risk group using six independent prognostic factors. This prognostic model may help design the study and develop the plans of individualized treatment.

[Expression of monocyte chemotactic protein-1 and its receptor in sudden coronary death].

OBJECTIVE: To investigate the expression of monocyte chemotactic protein-1 (MCP-1) and its receptor CC chemokine receptor-2 (CCR-2) in coronary atherosclerosis plaques between sidden coronary death (SCD) and non-SCD. Methods The expression levels of MCP-1 and CCR-2 in SCD group, coronary atherosclerosis group (non-SCD), control group (normal coronary artery) were detected by immunohistochemistry. RESULTS: Positive rates of MCP-1 among the three groups were 78%, 47%, and 0%, respectively, with significant expressing differences between each two groups (P<0.05). Positive rates of CCR-2 among three groups were 72%, 47%, and 0%, respectively, with significant expressing differences between the SCD group and coronary atherosclerosis group as well as between the SCD group and control group (P<0.05), but with no significant expressing difference between coronary atherosclerosis group and control group (P>0.05). CONCLUSION: Overexpression of MCP-1 and CCR-2 in coronary atherosclerotic plaques is closely correlated with SCD.