Dr. Angshuman Sarkar, Associate Professor, Birla Institute of Technology & Science, Pilani – Goa, India

Dr. Angsuman Sarkar is Associate Professor in the Department of Biological Sciences, BITS Pilani K K Birla Goa Campus Goa, India. He obtained his Ph.D. degree from Department of Biotechnology University of Pune, India. He went for a Post-Doctoral training in Cold Spring Harbor Laboratory, New York, USA for 3 years. After finishing there he joined Department of Molecular Biology and Microbiology in Case Western Reserve University in Cleveland, USA as a senior research fellow. Later on he was offered Associateship in the Cancer Biology Department in Cleveland Clinic Foundation, Cleveland, USA. He is presently involved in research related to nanotoxicology, molecular cancer biology and molecular toxicology. He has published more than 50 research papers/abstracts in various International journals and proceedings.

Speech Title: The story of 'escaping the zone of stresses' of human alveolar cells due to exposure to metal oxide nanoparticles and involvement of few key players

Abstract: Exposure of engineered nanoparticles becomes inevitable in today’s world and thus there is an increasing concern on nanomaterial safety and induced toxicity. Owing to small size and high surface area, nanoparticles are more penetrable and reactive with biological tissue than their bulk counterparts. Metal oxide nanoparticles are the largest class of manufactured nanomaterials, owing to their wide range of application. The exposure is pronounced at industries and manufacturing facilities that discharge waste including aerosolized suspensions. A large part of atmospheric presentation as vehicular effluents also adds to environmental pollution. Such a widely encountered exposure can present risk of toxicity. A systematic approach has been carried out with a less lethal (TiO₂ and a highly lethal (ZnO) metal oxide nanoparticle in understanding the differences between cellular responses to their exposure. Alveolar type II cells, A549 cell line is outlined for the scope of this study, which are widely studied as in vitro models. Type II alveolar cells are highly robust in nature, yet susceptible to aerosolized nanoparticles (NPs). Scores of published literatures affirm ZnO NPs are more toxic to human alveolar cells than TiO₂ However, signalling cascades deducing differences in cellular responses to their exposure is not well documented. With A549 cells, we have demonstrated that epithelial to mesenchymal transition and a pronounced phosphorylation of eIF2α are crucial mechanisms routing better tolerance to TiO₂ NP treatment over exposure to ZnO. The increased migratory capacity may help cells escape away from the zone of stress. Expression of chaperone such as Hsp70 is also enhanced during the same dose-time period. This is the first report of its kind. These novel findings could be successfully developed in the future to design relief strategies to alleviate metal oxide nanoparticle mediated stress.