Key role of Extracellular RNA in hypoxic stress induced myocardial injury

PLoS One. 2021 Dec 9;16(12):e0260835. doi: 10.1371/journal.pone.0260835. eCollection 2021.

Abstract

Myocardial infarction (MI), atherosclerosis and other inflammatory and ischemic cardiovascular diseases (CVDs) have a very high mortality rate and limited therapeutic options. Although the diagnosis is based on markers such as cardiac Troponin-T (cTrop-T), the mechanism of cTrop-T upregulation and release is relatively obscure. In the present study, we have investigated the mechanism of cTrop-T release during acute hypoxia (AH) in a mice model by ELISA & immunohistochemistry. Our study showed that AH exposure significantly induces the expression and release of sterile inflammatory as well as MI markers in a time-dependent manner. We further demonstrated that activation of TLR3 (mediated by eRNA) by AH exposure in mice induced cTrop-T release and Poly I:C (TLR3 agonist) also induced cTrop-T release, but the pre-treatment of TLR3 immuno-neutralizing antibody or silencing of Tlr3 gene or RNaseA treatment two hrs before AH exposure, significantly abrogated AH-induced Caspase 3 activity as well as cTrop-T release. Our immunohistochemistry and Masson Trichrome (MT) staining studies further established the progression of myocardial injury by collagen accumulation, endothelial cell and leukocyte activation and adhesion in myocardial tissue which was abrogated significantly by pre-treatment of RNaseA 2 hrs before AH exposure. These data indicate that AH induced cTrop-T release is mediated via the eRNA-TLR3-Caspase 3 pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Disease Models, Animal
  • Extracellular Vesicles / genetics*
  • Hypoxia / physiopathology*
  • Mice
  • Myocardial Infarction / genetics
  • Myocardial Infarction / metabolism
  • Myocardial Infarction / pathology*
  • RNA / genetics*
  • RNA / metabolism
  • Signal Transduction
  • Toll-Like Receptor 3 / genetics
  • Toll-Like Receptor 3 / metabolism*
  • Troponin T / metabolism*

Substances

  • TLR3 protein, mouse
  • TNNT2 protein, human
  • Toll-Like Receptor 3
  • Troponin T
  • RNA
  • CASP3 protein, human
  • Caspase 3

Grants and funding

This work was supported by grants from the Ministry of Defense (DIP253), Govt. of India and Grand Challenge Canada (R-ST-POC-1807- 13914) to GAK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.