78 - LPS Infection Increasing ROS Level Regulates Stress Signaling Cascades, Inflammation and Apoptosis in Keratinocyte after 2-Chloroethyl Ethyl Sulphide Challenge

Abstract

2-chloroethyl ethyl sulphide (CEES), a monofunctional analog of sulfur mustard (SM), is a well-known chemical warfare agent that induces vesicles or blisters on cutaneous toxicity in exposed individuals. CEES form highly reactive electrophilic sulphonium ions, which attack nucleophilic centers of biomolecules especially nucleic acid, caused damage in epithelial layers of skin, lungs and eye. Infection with the bacterial endotoxin lipopolysaccharides (LPS) are important immune system infection cues in epithelial layers of skin, but it remains unknown the molecular mechanisms to activate signaling cascades regulates inflammation and loss of cell-cell communication after CEES exposure. In the present study, we investigate the molecular mechanisms of inflammation and loss of cell-cell communication after LPS infection with CEES exposure on keratinocytes. Our results shows that LPS infection with CEES exposure enhanced accumulation of reactive oxygen species (ROS), resulting in the activation of nuclear factor κB (NF-κB) via ERK1/2MAPK/Akt/tuberin-mTOR pathways, which subsequently subdue the pro-inflammatory mediators, apoptosis and lose of cell-cell communication, leading to biomolecules damage. Protection against LPS infection with CEES toxicity could also be performed by blocking of ROS activation with antioxidant N-acetyl-L-cysteine (NAC), and ERK1/2MAPK (PD98059, U0126) and Akt inhibitors (LY294002, Wortmannin), which inhibit the intracellular redox-sensitive signaling pathways regulates inflammation and cell-cell communication. These results illustrate that accumulated ROS in mouse keratinocytes functions as a key NF-κB signaling cascade via ERK1/2MAPK/Akt/tuberin-mTOR regulatory pathways induced by CEES after LPS infection, leading to inflammation, apoptosis and loss of cell-cell communication, which is attenuated by antioxidant NAC, ERK1/2MAPK and Akt inhibitors. This work was supported by Indian Council of Medical Research (ICMR), Grant: 53/21/2010-CMB/BMS/ICMR, Government of India to Dr. Arttatrana Pal.