Delivery of Bcl-XL or its BH4 domain by protein transduction inhibits apoptosis in human islets

Dagmar Klein, Melina M. Ribeiro, Valeska Mendoza, Sundararajan Jayaraman, Norma S. Kenyon, Antonello Pileggi, R. Damaris Molano, Luca Inverardi, Camillo Ricordi, Ricardo L. Pastori

Research output: Contribution to journalArticlepeer-review

67 Scopus citations


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-1β 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.

Original languageEnglish (US)
Pages (from-to)473-478
Number of pages6
JournalBiochemical and biophysical research communications
Issue number2
StatePublished - Oct 15 2004


  • β-cells
  • Bcl-XL
  • BH4
  • Islets
  • Protein transduction
  • Protein transduction domains

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology


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