1α,25-Dihydroxyvitamin D3 Induces Neutrophil Apoptosis Through P38MAPK Signaling Pathway In Type 2 Diabetes Mellitus Patients With Periodontitis

Objective: Observe the effect of 1α,25 Vit D3 on peripheral blood neutrophil apoptosis and apoptosis relative factors expression including Caspase-3,Bax and Bcl-2 in type 2 diabetes mellitus patients with periodontitis,investigate the mechanism of the p38 MAPK signaling pathway in the process of neutrophil apoptosis.Methods: Seventy-six adult patients(52 males,24females)have type 2 diabetes mellitus with chronic moderate to severe periodontitis were participated in this experiment.The peripheral blood neutrophils of these participants were collected and separated by density gradient centrifugation.The experiment were divided into control group(no drug intervention),1α,25 Vit D3 intervention group,1α,25 Vit D3 and blocker(SB203580D)group;the hematoxylin and eosin stain of neutrophils were observed under inverted phase contrast microscope.The expression of P38 MAPK signaling pathway relevant protein include p38,p-p38 and apoptosis relevant protein like Caspase-3,Bax and Bcl-2 were detected by the Western blot assay.The reverse transcription quantitative real-time polymerase chain reaction were performed to investigate the m RNA level of P38,Caspase-3,Bax,Bcl-2 during each group.The apoptosis of neutrophils were inspected by FCM.Results: 1.The FCM analysis showed the rate of apoptosis in 1α,25 Vit D3 group were higher than the 1α,25 Vit D3,blocker group and control group(P<0.01)after use 10-8 mol/L 1α,25 Vit D3 in 1α,25 Vit D3 group,1α,25 Vit D3 and blocker group for 24 hours.2.The Western blot analysis showed the phosphorylated P38(P-P38),Caspase-3 and Bax expressed highest in 1α,25 Vit D3 group and lowest in control group after 1α,25 Vit D3 on PMN for 24 hours;the expression of P-P38 in 1α,25 Vit D3 and blocker group were posterior than 1α,25 Vit D3 group,the control group were the lowest;the expression of Caspase-3 and Bax were positive correlated to P-P38 and negative correlation were detected between Bcl-2 and P-P38.3.The m RNA expressions of P38 in all groups have no statistic differences(P>0.05).The gene expression of Caspase-3 and Bax/Bcl-2 were upregulated greatly in 1α,25 Vit D3 group than other groups,which the control group were the lowest(P<0.01).Bcl-2m RNA level of medication group was lowest,followed by medication + blocker group,the highest expression level in control group(P<0.01).Conclusion: 1.The P38 MAPK signaling pathway were activated by using 1α,25 Vit D3 and 1α,25 Vit D3 promote the apoptosis of neutrophils in patients had type 2 diabetes mellitus with chronic moderate to severe periodontitis.2.There are other signaling pathways existed in the mechanism which 1α,25 Vit D3 act on neutrophils in patients who have type 2 diabetes mellitus with periodontitis...