Delivery of Bcl-XL or its BH4 domain by protein transduction inhibits apoptosis in human islets.
Viability of isolated islets is one of the main obstacles limiting islet transplantation success. It has been reported that overexpression of Bcl-2/Bcl-XL proteins enhances islet viability. To avoid potential complications associated with long-term expression of anti-apoptotic proteins, we investigated the possibility of delivering Bcl-XL or its anti-apoptotic domain BH4 to islets by protein transduction. Bcl-XL and BH4 molecules were fused to TAT/PTD, the 11-aa cell penetrating peptide from HIV-1 transactivating protein, generating TAT-Bcl-XL and TAT-BH4, respectively. Transduction efficiency was assessed by laser scanning confocal microscopy of live islets. Biological activity was tested as the ability to protect NIT-1 insulinoma cell line from death induced by staurosporine or serum deprivation. Spontaneous caspase activation in human islets and cytotoxicity caused by IL-1beta were significantly reduced in the presence of TAT-Bcl-XL and TAT-BH4. We conclude that both TAT proteins are biologically active after transduction and could be an asset in the improvement of islet viability.
Klein
Dagmar
D
Diabetes Research Institute, University of Miami School of Medicine, Miami, FL, USA.
Ribeiro
Melina M
MM
Mendoza
Valeska
V
Jayaraman
Sundararajan
S
Kenyon
Norma S
NS
Pileggi
Antonello
A
Molano
R Damaris
RD
Inverardi
Luca
L
Ricordi
Camillo
C
Pastori
Ricardo L
RL
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D005240:Feasibility Studies; D024861:Genetic Enhancement / Q000379:methods; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D011323:Primates; D015202:Protein Engineering / Q000379:methods*; D017434:Protein Structure, Tertiary / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology; D014161:Transduction, Genetic / Q000379:methods*; D051020:bcl-X Protein
C494811:BCL2L1 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D051020:bcl-X Protein; D019311:Staurosporine