An interfering peptide attenuates diabetic encephalopathy by blocking the interaction between CD44 and STAT3

Area of Science:

• Neuroscience
• Endocrinology
• Molecular Biology

Background:

• Diabetic encephalopathy (DE) is a significant neurological complication of diabetes with unclear pathogenesis.
• Elevated CD44 levels in diabetes patients correlate with cognitive impairment.

Purpose of the Study:

• To elucidate the molecular mechanism linking CD44 and STAT3 in diabetic cognitive deficits.
• To investigate the therapeutic potential of blocking the CD44-STAT3 interaction for DE.

Main Methods:

• Identified a specific CD44 C-terminal region (residues 722-729) that binds to STAT3's SH2 domain.
• Designed and administered a CD44-STAT3 interfering peptide in vitro and in vivo (db/db mice).
• Assessed STAT3 phosphorylation, apoptosis pathways, hippocampal synaptic function, and cognitive performance.

Main Results:

• The CD44-STAT3 interaction promotes STAT3 phosphorylation and nuclear translocation.
• The interfering peptide successfully blocked CD44-STAT3 complex formation, inhibiting STAT3 activation and downstream apoptosis.
• Treatment with the peptide ameliorated hippocampal synaptic deficits and cognitive impairments in diabetic mice.

Conclusions:

• Formation of the CD44-STAT3 complex under hyperglycemia is a key driver of neuronal apoptosis in DE.
• Targeting the CD44-STAT3 interaction represents a promising novel therapeutic approach for diabetic encephalopathy.