Adenovirus-mediated Rat Insulin-like Growth Factor 1 Gene In Islet ¦Â Cell Injury Protection,

Objective To observe the role of adenovirus vector mediated rat insulin-like growth factor 1(rIGF-1) gene on streptozotocin-induced isletβ-cells impairment in vitro. To investigate the protective role of adenovirus vector mediated rIGF-1 on streptozotocin (stz) -induced diabetic mellitus of Wistar mice,and observe the difference among different ways of injection.Methods Infecte RINm5F cells with recombinant adenovirus encoding rIGF-1 gene.RIGF-1 protein was detected by Western blot analysis and ELISA method.Then streptozotocin was used to induce RINm5F cells impairment.The cells function was evaluated by glucose-stimulated insulin production.Ninety male Wistar mice aged from four to five weeks were randomly divided into six groups.Group 1 is diabetes mellitus control goup;Group 2 is vacuity group;Group 3 received the intraperitoneal injection of adenovirus vector mediated empty green fluorescence protein(Ad-eGFP).Group 2 is normal control group without special disposal.Group 4-6 received intraperitoneal injection of adenovirus vector mediated rIGF-1 gene(0.1ml) separatedly by intramuscular injection,intraperitoneal injection and pancreas tegument injection.Later, Group 1 and 4-6 received intraperitoneal injection of stz 50mg/kg(dissolved in 0.1mol/L citrate buffer,PH 4.5,immediately before administration ) in order to induce diabetic mellitus of Wistar mice.Mice were fed and libitum with a standard diet.Weight and glycemia of all mice were measured once a week.Five weeks later,all mice were executed and pancreata were fixed for more 12-24 hours,embedded in paraffin,and sectioned.We observed the incidence of diabetic mellitus,the degree of pancrea inflammatory infiltration,the expression of rIGF-1 detected with the immunohistochemical and enzyme linked immunosorbent assay(ELISA) techniques.Results 1:The rIGF-1 was expressed in the RINm5F cells and cells culture supernatants.RIGF-1 can inhibite islet cell apoptosis.2:Compare with control group, experimental group have a lower incidence in diabetes and a lower degree of average blood glucose;pancrea pathology show that inflammatory infiltration is lighter; immunohistochemical show that rIGF-1 have a higher expression in islet cell;insulin in serum detected by ELISA show a higher degree in experimental groups,but rIGF-1 in serum have no different in all groups.Conclusion 1:These results suggested that locally produced rIGF-1 from cultured islets may be beneficial in maintainingβcells function,protecting islet cells from apoptosis-mediated factors and promoting islet survival,which showed the potential therapy for type 1 diabetes mellitus.Adenovirus vector mediated rIGF-1 can protect streptozotocin(stz) -induced diabetic mellitus of Wistar mice from diabetes in some degree,have no relationship with the ways of injection.