ABSTRACT
Objective To investigate the effects of icariin on high glucose-induced autophagy and apoptosis of podocytes,and the regulating effects on mammalian target of rapamycin(mTOR)/serine-threonine kinase(Akt)/cyclic adenosine monophosphate response element binding protein(CREB)pathway.Methods The mouse podocytes MPC5 were taken and divided into five groups:normal control group(5.5 mmol·L-1 glucose),high glucose group(30 mmol·L-1 glucose),icariin group(30 mmol·L-1glucose+5 μmol·L-1icariin),GDC-0349 group(30 mmol·L-1glucose+50 μmol·L-1 GDC-0349),icariin+GDC-0349 group(30 mmol·L-1 glucose+5 μmol·L-1 icariin+50 μmol·L-1 GDC-0349).Cultured for 48 hours,the tetramethylazozolium salt method was used to detect the viability of MPC5 cells;acridine orange staining was used to observe the autophagy of MPC5 cells;apoptosis of MPC5 cells was detected by flow cytometry;Western blotting was used to detect the expression of autophagy[microtubule associated protein one light chain 3(LC3)II,LC3Ⅰ,autophagy-related protein(Beclin-1)],apoptosis[Bcl-2 related X protein(Bax),B cell lymphoma-2(Bcl-2)]and mTOR/Akt/CREB pathway-related proteins of MPC5 cells.Results Compared with the normal control group,the cell viability,expression levels of Bcl-2,phosphorylated mTOR(p-mTOR)/mTOR,phosphorylated Akt(p-Akt)/Akt,phosphorylated CREB(p-CREB)/CREB protein of MPC5 cells in the high glucose group were significantly decreased(P＜0.05),the autophagy ability was enhanced,the autophagosome showed orange fluorescence,and the apoptosis rate,LC3Ⅱ/LC3Ⅰ,Beclin-1,Bax protein expression levels were significantly increased(P＜0.05).Compared with the high glucose group,the cell viability,LC3Ⅱ/LC3Ⅰ,Beclin-1,Bcl-2,p-mTOR/mTOR,p-Akt/Akt,p-CREB/CREB protein expression levels of MPC5 cells in icariin group were significantly increased,the autophagy ability was further enhanced,the number of autophagosomes was increased,the autophagosomes showed brick red fluorescence(P＜0.05),the apoptosis rate and Bax protein expression level were significantly decreased(P＜0.05),and the cell viability,LC3Ⅱ/LC3Ⅰ,Beclin-1,Bcl-2,p-mTOR/mTOR,p-Akt/Akt and p-CREB/CREB proteins expression levels of MPC5 cells in GDC-0349 group were significantly decreased,the autophagy ability was weakened,the number of autophagosomes was reduced,the autophagosomes showed orange fluorescence(P＜0.05),and the apoptosis rate and Bax protein expression level were significantly increased(P＜0.05);icariin+GDC-0349 could reverse the effect of icariin on high glucose induced MPC5 cells(P＜0.05).Conclusion Icariin promotes elevated glucose-induced podocyte autophagy and inhibits apoptosis by activating the mTOR/Akt/CREB pathway.
ABSTRACT
Objective To investigate the effect of vitamin D supplementation on biochemical imdexes and compliations in patients with type 2 diabetes(T2DM).Methods Two hundred and ten patients with type 2 diabetes of the People's Hospital of Chongli County were selected from January 2001 to January 2002.According to the envelope sampling method they were divided into vitamin D supplementation group of 105 people and not supplemented group of 105 people,and 105 healthy people at the same period as control group.Compared the biochemical baseline indicators differences.After 10 years of follow-up,the biochemical indexes and the complications were detected and compared again.Results After ten years follow-up,82 cases of supplementation group were followed up,78 cases of not supplemented group were followed up.The level of FPG and HbA1c of supplementation group and not supplementation group were higher than that of control group,the differernce was significant(P＜0.05).In supplement group,TG levels,25(OH) D3 concentrations and BMD values were (2.11±0.41) mmol/L,(16.88±5.02) μg/L and-1.15±(-0.25) respectively,and equal to the control group ((2.12 ± 0.38) mmol/L,(44.83 ± 21.25) mmol/L,-0.94 ± (-0.21)),and TG levels were lower than not supplemented group,25 (OH) D3 concentrations and high bone density higher than not supplemented group((24.53±15.61) mmol/L,-3.15±(-0.33),P＜0.05).FPG,Cr,BUN,UA,FIB,and BNP in supplement group were(10.00±2.32) mmol/L,(64.77±9.31) μmol/L,(6.41± 1.24) mmol/L,(339.83±43.74) mmol/L,(2.41±0.46) g/L and (588.92±73.69) ng/L,in not supplemented group were (15.60±2.51) mmol/L,(92.69±11.68).μmol/L,(8.70±2.35) mmol/L,(398.94±49.13) mmol/L,(2.89±0.54) g/L and (761.09±91.52) ng/L,all higher than those in control group ((5.01 ±0.59) mmol/L,(57.81±6.61) μmol/L,(4.52±1.11) mmol/L,(311.83±49.51) mmol/L,(2.00±0.31) g/L,(434.31 ± ±71.03) ng/L),and those indexes in supplement group all higher than in not supplemented group(P＜0.05).The level of HbA1c of supplement group and not supplemented group both higher than control group((11.32 ± ±2.03) ％,(13.22±4.17) ％ and (5.34±1.99) ％,P＜0.05).There were 45 cases in supplement group occurred diabetic nephropathy and cardiovascular complications,and 65 cases of not supplemented group (x2 =15.07,P＜0.05).Conclusion The relationship of Vitamin D and various complications of diabetes mellitus are closely,and supplementing vitamin D can reduce the complications of diabetes.