BACKGROUND:Abnormal activation of osteoclasts plays an important role in the bone destruction due to spinal tuberculosis.During the pathogenesis of osteoporosis,miR-155 knockdown activates adenosine phosphate-dependent protein kinase(AMPK)by increasing the expression of leptin receptors,thereby inhibiting osteoclast differentiation and bone resorption.However,the role of miR-155/leptin receptor(LEPR)/AMPK axis in the bone destruction due to spinal tuberculosis remains unclear. OBJECTIVE:To investigate the role and mechanism of miR-155/LEPR/AMPK axis in tuberculin-induced osteoclast formation. METHODS:RAW264.7 cells were cultured and treated with different concentrations of purified protein derivative(PPD)(1.0,2.5,5.0,10.0 IU/mL)and transfected with negative control(NC)sequence or miR-155 inhibitor,NC siRNA sequence or LEPR siRNA sequence.Tartrate resistant acid phosphatase staining was used to detect the number of osteoclasts.Fluorescence quantitative PCR was used to detect the expression of miR-155.Western blot was used to detect the expression of LEPR and p-AMPK.Double luciferase reporter gene was used to verify miR-155 targeting LEPR. RESULTS AND CONCLUSION:Compared with the control group,the number of osteoclasts and the expression level of miR-155 significantly increased,while the expression level of LEPR and p-AMPK significantly decreased in 2.5,5.0,and 10.0 IU/mL PPD groups(P＜0.05).Compared with NC+5.0 IU/mL PPD group,the number of osteoclasts and the expression level of miR-155 significantly decreased,while the expression level of LEPR and p-AMPK significantly increased in the miR-155 inhibitor+5.0 IU/mL PPD group(P＜0.05).Compared with the NC group,the fluorescence activity of LEPR wild-type double luciferase reporter gene was increased in the miR-155 inhibitor group,and decreased in the miR-155 mimic group(P＜0.05).Compared with si-NC+miR-155 inhibitor+5.0 IU/mL PPD group,the expression level of miR-155 had no significant change,the number of osteoclasts significantly increased,and the expression levels of LEPR and p-AMPL significantly decreased in si-LEPR+miR-155 inhibitor+5.0 IU/mL PPD group(P＜0.05).To conclude,tuberculin can induce osteoclast formation by increasing miR-155 expression and inhibiting downstream LEPR expression and AMPK activation.

_ Objective_ To analyze the relationship between the fasting plasma glucose ( FPG ) of pre-pregnancy women and occurrence of gestational diabetes mellitus( GDM) , and to explore the value of risk evaluation of GDM by lowerling cut-point for impaired fasting glucose ( IFG ) . Methods The general clinic check information before pregnancy, the plasma glucose levels during 24-28 weeks of pregnancy and pregnancy outcomes were collected prospectively in Weifang and Zhucheng Maternal and Child Health Hospital between February 2014 and November 2014. The FPG levels of the recruited women were lower than 6. 1 mmol/L. According to the criteria for GDM of Ministry of Health (MOH)of China in 2011, and based on the results of 75 g oral glucose tolerance test, pregnant women who underwent screening for GDM were recruited and separated into normal group and GDM group. Based on the FPG levels before pregnancy and according to the recommendation as American Diabetes Association ( ADA ) suggested in 2003, recruited women with normal FPG level according to World Health Organization ( WHO) criteria (1999)were divided into 5. 6-6. 1 mmol/L and<5. 6 mmol/L groups. Results Among the child-bearing age women with FPG<6. 1 mmol/L, the incidences of GDM and macrosomia were 19. 2% and 8. 2% respectively. In the group with FPG between 5. 6 and 6. 1 mmol/L, incidences of GDM and macrosomia were 34. 2% and 4. 7%respectively. While in the group with FPG<5. 6 mmol/L, incidences of GDM and macrosomia were 13. 2% and 15. 3% respectively. The risks of GDM and macrosomia were increased by 2. 6 times and 3. 3 times respectively in group with FPG between 5. 6 and 6. 1 mmol/L (34. 5%), compared with that in group with FPG<5. 6 mmol/L(P<0. 01). Age, FPG, and body mass index before pregnancy in GDM group were significantly higher than those in normal group. The receiver operating characteristic curves in predicting GDM showed that the optimum cut-points for age, FPG, and body mass index were 30 years old, 5. 55 mmol/L, and 23. 7 kg/m2 respectively. Conclusions The risk of GDM in childbearing aged women with FPG from 5. 55 to 6. 10 mmol/L was markedly increased. The optimum cut-point for FPG (5. 55 mmol/L) in predicting GDM was close to the low limit for IFG (5. 6 mmol/L) suggested by ADA in 2003. Decreasing the lower limit of IFG to 5. 6 mmol/L among women who checked before pregnancy and paying attention to those women with FPG from 5. 6 to 6. 1 mmol/L would have advantage to the evaluation and prevention of GDM.