Effect Of 1,25（OH）₂D₃ On The Transdifferentiation Of Renal Tubular Epithelial Cells In High Glucose State By Regulating STAT3 Pathway

Objective:1.To observe the effects of high glucose environment on the transdifferentiation of human renal tubular epithelial cells;2.To explore whether 1,25（OH）2D3 can protect the transdifferentiation of human renal tubular epithelial cells induced by high glucose,and detect the change of JAK/STAT pathway protein STAT3,and research the possible mechanism of1,25（OH）2D3 for the treatment of clinical diabetic nephropathy.Mthods:Human proximal tubular epithelial cells were stimulated with high glucose medium at a concentration of 30mmol/L.Cells were collected at 12 h,24 h,and 48 h,and normal controls were established at each time point.Real Time-PCR was used to detect the relative expression levels of SMA mRNA,E-cadherin mRNA and pSTAT3 mRNA in each group,and the optimal time was determined to be 48h.Next step,the proximal human renal tubular epithelial cells cultured in vitro were divided into normal control group（glucose 5.5mmol/L）,high glucose group（glucose 30mmol/L）,high glucose+1,25（OH）₂D₃ 10^-10mmol/L,high glucose+1,25（OH）₂D₃ 10^-9mmol/L,high glucose+1,25（OH）₂D₃ 10^-8mmol/L,each group of cells was collected after 48 hours.The proteins level ofα-SMA,E-cadherin and pSTAT3 in each group were detected by Western-Blot.Results:When cells were stimulated by high glucose for different times,the expression of αSMA mRNA and pSTAT3 mRNA in each group were significantly higher than those in the control group（p<0.05）,and increased with the stimulation time.The E-cadherin mRNA level was significantly lower than the control group（p<0.05）,and showed a decreasing trend with the stimulation time.When 1,25（OH）₂D₃ of different concentrations and high glucose were intervened for 48 hours,theprotein expression levels ofα-SMA,pSTAT3 were significantly lower than those in the high glucose group（P<0.005）,and decreased with the increasing dose of 1,25（OH）₂D₃.The protein expression levels of E-cadherin were significantly higher than those in the high glucose group（P<0.005）,and increased with the increasing dose of 1,25（OH）₂D₃.Conclusions:1.High glucose environment can promote the transdifferentiation of renal tubular epithelial cells,activate the STAT3 signal pathway,and promote the progression of renal interstitial fibrosis;2.1,25（OH）₂D₃ can alleviate the transdifferentiation of renal tubular epithelial cells induced by high glucose,and the mechanism may be related to the inhibition of STAT3signaling pathway.