To pursue insulin and islet transplantation replacement therapy for type 1 diab etes based on engineered human non β cells which secrete mature insulin Methods Human proinsulin cDNA was cloned from its genomic ge...To pursue insulin and islet transplantation replacement therapy for type 1 diab etes based on engineered human non β cells which secrete mature insulin Methods Human proinsulin cDNA was cloned from its genomic gene and mutated by overlap e xtension PCR, introducing furin consensus cleavage sequences (Arg Xaa Lys/Arg Arg) An expression vector encoding a genetically modified human proinsulin c DNA was generated and transduced to Hela, 293, and L02 cells by lipofectin medi ated DNA transfection Following G418 screening, the surviving L02 cells were s elected and enriched Insulin levels in the supernatant and cells were evaluate d using radioimmunoassay and immunofluorescence staining Results Three sites in the insulin gene were mutated simultaneously Insulin gene m odified cells were able to express insulin at different levels: 8 45-188 00? μIU/24 h/2 0×10 6 Hela cells and 159 88-242 14?μIU/24 h/2 0×10 6 293 cells for transient expression, and 2 56-61 95?μIU/24 h/2 0×10 6 from se veral L02 clones screened with G418 No insulin was released by control cells Furthermore, immunofluorescence staining confirmed that proinsulin was stored a s vacuoles in the cytoplasm of L02 cells Conclusion A correctly mutated human proinsulin cDNA was obtained successfully, transfected and expressed efficiently in non beta cells, lending support to the study of s omatic gene therapy in diabetes mellitus展开更多
基金agrantfromtheShanghaiMunicipalGovernment (No 9841190 2 4)
文摘To pursue insulin and islet transplantation replacement therapy for type 1 diab etes based on engineered human non β cells which secrete mature insulin Methods Human proinsulin cDNA was cloned from its genomic gene and mutated by overlap e xtension PCR, introducing furin consensus cleavage sequences (Arg Xaa Lys/Arg Arg) An expression vector encoding a genetically modified human proinsulin c DNA was generated and transduced to Hela, 293, and L02 cells by lipofectin medi ated DNA transfection Following G418 screening, the surviving L02 cells were s elected and enriched Insulin levels in the supernatant and cells were evaluate d using radioimmunoassay and immunofluorescence staining Results Three sites in the insulin gene were mutated simultaneously Insulin gene m odified cells were able to express insulin at different levels: 8 45-188 00? μIU/24 h/2 0×10 6 Hela cells and 159 88-242 14?μIU/24 h/2 0×10 6 293 cells for transient expression, and 2 56-61 95?μIU/24 h/2 0×10 6 from se veral L02 clones screened with G418 No insulin was released by control cells Furthermore, immunofluorescence staining confirmed that proinsulin was stored a s vacuoles in the cytoplasm of L02 cells Conclusion A correctly mutated human proinsulin cDNA was obtained successfully, transfected and expressed efficiently in non beta cells, lending support to the study of s omatic gene therapy in diabetes mellitus
