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Formation of STAT5/PPARgamma transcriptional complex modulates angiogenic cell bioavailability in diabetes

Patrizia Dentelli1, Antonella Trombetta, Gabriele Togliatto

  • 1Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy.

Arteriosclerosis, Thrombosis, and Vascular Biology
|October 18, 2008
PubMed
Abstract

Insights

STAT5 and PPARgamma form a complex that drives circulating angiogenic cell (CAC) expansion. This STAT5/PPARgamma interaction can be targeted to potentially restore CAC function in diabetic patients.

Area of Science:

  • Cellular biology
  • Molecular mechanisms of angiogenesis
  • Transcriptional regulation

Background:

  • Circulating angiogenic cells (CACs) expansion is crucial for vascular repair.
  • STAT5 and peroxisome proliferator-activated receptors (PPARs) are key regulators of cellular processes.
  • The interplay between STAT5 and PPARgamma in CAC expansion is not fully understood.

Purpose of the Study:

  • To investigate the role of STAT5 and PPARgamma in regulating CAC expansion.
  • To elucidate the molecular mechanisms underlying STAT5 and PPARgamma interactions in CACs.
  • To explore therapeutic potential for diabetic CAC dysfunction.

Main Methods:

  • siRNA technology, electrophoretic mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP) assays.
  • Site-directed mutagenesis and coimmunoprecipitation experiments.
  • Flow cytometry (FACS) analysis to assess cell-cycle progression.

Main Results:

  • STAT5 directly controls PPARgamma expression via transcriptional activity.
  • A STAT5/PPARgamma complex regulates cyclin D1 expression and promotes CAC cell-cycle progression.
  • PPARgamma agonists alone did not enhance CAC expansion; conversely, activating the STAT5/PPARgamma complex restored diabetic CAC function.

Conclusions:

  • STAT5/PPARgamma heterodimers are critical for CAC expansion.
  • This study identifies a mechanism to partially rescue CAC bioavailability in diabetic settings.
  • Targeting the STAT5/PPARgamma pathway offers a potential therapeutic strategy for diabetic vascular complications.

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