toll-like receptor 4 in ventilator-induced lung injuries: mechanism of disease

Toll like receptors (tlrs) are pathogen recognition molecules with widespread expression in the cells and tissues. among them, tlr4 is involved in several important diseases. tlr4 can be stimulated by endogenous ligands as well as bacteria and viruses. tlr4 stimulation on the surface of monocytes leads to production of pro-inflammatory cytokines. it is documented that mechanical ventilation with tidal volumes of 40 ml/kg is able to induce inflammation. the mechanism of action of mechanical ventilation may involve increasing in tlr2 and tlr4 expression. here we review the current understanding about tlr4 and lung injuries in basic and clinical science.