Effects of insulin and pioglitazone on proliferation,apoptosis and NO secretion of endothelial progenitor cells

Objective To investigate the effects of pioglitazone and insulin on proliferation,apoptosis and nitric oxide(NO)secretion of endothelial progenitor cells(EPCs)derived from bone marrow.Methods Thirty-two SD rats were randomly divided into pioglitazone group,which was given pioglitazone(20 mg·kg-1·d-1)by intragastric administration for 10 d,and non-pioglitazone group,which was given physiologic saline(0.9%)of the same volume.Each group included 16 rats.Mononuclear cells were collected from rats' bone marrow by density gradient centrifugation,cultured with M 199 medium,and identified by UEA-I and ac-LDL staining.Of them the double positive ones were EPCs.Once harvested,EPCs of both groups were given vehicle or insulin(1 nmol/L)respectively.After 24 h of incubation,NO secretion of EPCs was measured by the Griess assay with spectrophotometer.After incubation for 3 d,apoptosis was detected by FCM.After 7 d of incubation,proliferation capacity was measured by MTT assay.Results Pioglitazone given in vivo could increase the number of EPCs.Compared with the control group,pioglitazone and insulin group,insulin group and pioglitazone group respectively showed higher proliferation capacity(P0.01),lower EPCs apoptosis(P0.05),and more NO production(P0.05).Conclusion Both pioglitazone given in vivo and insulin given in vitro can stimulate EPCs proliferation,decrease its apoptosis,and promote its secretion of NO,and these two kinds of intervention have synergistic effects.