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Screening Assays to Characterize Novel Endothelial Regulators Involved in the Inflammatory Response
12:50

Screening Assays to Characterize Novel Endothelial Regulators Involved in the Inflammatory Response

Published on: September 15, 2017

Endothelial STAT3 plays a critical role in generalized myocardial proinflammatory and proapoptotic signaling

Meijing Wang1, Wenjun Zhang, Paul Crisostomo

  • 1Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.

American Journal of Physiology. Heart and Circulatory Physiology
|August 7, 2007
PubMed

Insights

Endothelial cell STAT3 (Signal transducer and activator of transcription 3) deficiency worsens heart function after ischemia-reperfusion injury. This study highlights the protective role of endothelial STAT3 in maintaining myocardial integrity and function.

Area of Science:

  • Cardiovascular Biology
  • Molecular Medicine
  • Cellular Signaling

Background:

  • Signal transducer and activator of transcription 3 (STAT3) is crucial for cell survival, proliferation, and immune responses.
  • STAT3 in cardiomyocytes offers cardioprotection against ischemic-oxidative stress.
  • The role of endothelial cell-derived STAT3 in myocardial response to ischemia-reperfusion (I/R) injury remains unclear.

Purpose of the Study:

  • To investigate the impact of endothelial cell-specific STAT3 ablation on myocardial I/R injury.
  • To determine if endothelial STAT3 deficiency affects capillary integrity and antiapoptotic signaling post-I/R.

Main Methods:

  • Isolated hearts from wild-type and endothelial cell STAT3 knockout (STAT3KO) mice were subjected to global ischemia and reperfusion.
  • Assessment of myocardial function recovery, cardiac enzyme release (LDH), STAT3 activation, p38 MAPK activation, apoptosis markers (caspase-8), and cytokine expression (IL-6, SOCS3).

Main Results:

  • Endothelial cell STAT3 deficiency significantly impaired myocardial function recovery post-I/R.
  • STAT3KO hearts exhibited increased LDH release, reduced myocardial STAT3 activation, and elevated p38 MAPK activation.
  • Increased myocardial caspase-8 expression and localized apoptosis around capillaries were observed in STAT3KO hearts.
  • Endothelial STAT3 ablation led to increased myocardial IL-6 and suppressor of cytokine signaling 3 (SOCS3) expression.

Conclusions:

  • Endothelial cell-derived STAT3 plays a critical protective role in mitigating myocardial dysfunction following I/R injury.
  • STAT3 deficiency in endothelial cells compromises capillary integrity and promotes pro-apoptotic signaling pathways.
  • Targeting endothelial STAT3 may represent a novel therapeutic strategy for ischemic heart disease.

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