Hypoxia induced Sterile Inflammation its role in Tissue Factor activation

Abstract

We hypothesized that eRNA released from dying cells under AH activates TF via the TLR3-ERK1/2-AP1 pathway, leading to VT. Animals were exposed to stimulate hypoxia for 0 24 h at standard temperature and humidity. RNaseA and DNase1 were injected immediately before exposure. TLR3 gene silencing was performed through in vivo injection of TLR3 siRNA. 80 and#956;g/kg BW of isolated eRNA and eDNA were injected6 h prior to sacrifice. Antigens of TF pathway were determined by ELISA and TF activity by a chromogenic assay. AH exposure significantly induced release of SI markers i.e. eRNA, eDNA, HMGB1 and up regulated TLR3, ERK1/2, AP1 and TF, whereas RNaseA pre-treatment diminished the effect of AH, thus inhibiting TF expression as well as activity during AH. Hence, we propose a possible mechanism of AH-induced TF activation and thrombosis where RNaseA can become the novel focal point in ameliorating therapy for AH induced thrombosis. Although the diagnosis is based on markers such as cardiac Troponin-T (cTrop-T). But the mechanism of their up regulation 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 and 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. Our study further showed that activation of TLR3 (mediated by eRNA) by AH exposure in mice induced cTrop-T release. Our immunohistochemistry as well as Masson Trichrome (MT) staining 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. These data indicate that AH induced cTrop-T release is mediated via the eRNA-TLR3-Caspase 3 pathway. newline