Cell penetrating caspase substrates promote survival of the transplanted cells

Area of Science:

• Biotechnology
• Cell Biology
• Regenerative Medicine

Background:

• Post-transplantation cell survival is limited by inflammation, poor vascularization, and inadequate cell attachment.
• Blocking cell death pathways can improve cell survival but requires careful control to avoid sustained inhibition or oncogenic transformation.
• Current methods using competitive caspase substrates offer temporary delays in apoptosis but do not prevent eventual cell death.

Purpose of the Study:

• To develop synthetic peptides that can temporarily inhibit effector caspases, thereby enhancing cell survival in critical post-transplantation periods.
• To design peptides with internalization motifs for efficient cellular uptake and targeted delivery.
• To evaluate the safety and efficacy of these peptide-based cell death inhibitors in vitro and in vivo.

Main Methods:

• Design and synthesis of peptides incorporating effector caspase cleavage sequences and cell internalization motifs.
• Assessment of peptide internalization into neuroblast cells using cytofluorimetry and mass spectrometry.
• In vitro evaluation of peptide-mediated protection against apoptogenic stimuli.
• In vivo assessment of peptide-enhanced survival of transplanted syngeneic immortalized Schwann cells.

Main Results:

• Synthetic peptides demonstrated rapid and efficient internalization into neuroblast cells.
• Internalization of peptides with fused motifs was superior to non-fused sequences.
• Pretreatment with selected peptides protected cells from various apoptogenic stimuli in vitro.
• Peptide pretreatment significantly improved the survival of transplanted Schwann cells in vivo.

Conclusions:

• Synthetic peptides effectively inhibit effector caspases, providing temporary protection against cell death.
• These peptides exhibit efficient cellular uptake and enhance cell survival in both in vitro and in vivo models.
• This peptide-based strategy represents a promising approach for improving cell survival in transplantation and regenerative medicine applications.