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Airway exposure of e‐cigarette‐vapors impairs autophagy and induces aggresome‐formation
Author(s) -
Shivalingappa Prashanth,
Westphal Colin,
Vij Neeraj
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.lb631
Subject(s) - aggresome , autophagy , chemistry , apoptosis , microbiology and biotechnology , oxidative stress , senescence , pharmacology , biochemistry , biology
Objective Electronic‐cigarettes (e‐cigarettes) are proposed to be a safer alternative to tobacco‐cigarettes. Hence, we evaluated if e‐cigarette‐vapors (eCV) impairs cellular proteostasis similar to cigarette‐smoke (CS)‐exposure. Results First, we evaluated the impact of eCV‐exposure (~2.5mg or 7.5mg) on Beas2b cells that showed significant increase in accumulation of ubiquitinated‐proteins (ub, insoluble‐fractions) with time‐dependent decrease in proteasomal‐activities from 1hr to 6hrs (p<0.01) of eCV‐exposure as compared to room‐air control. We verified that even minimal eCV‐exposure (1hr) induces valosin containing protein (VCP; p<0.01), sequestosome‐1/p62 (aberrant‐autophagy marker; p<0.05) and aggresome‐formation (ub‐accumulation) using immunoblotting (IB), fluorescence microscopy and immunopreciptation (IP). The inhibition of protein synthesis by 6hr cyclohexamide (50µg/ml) treatment significantly (p<0.01) alleviates eCV‐induced (1hr) aggresome‐bodies. We also observed that eCV (1hr) induced protein aggregation can activate apoptosis (caspase‐3/7) and senescence (SA‐β‐gal) activities (p<0.01) as compared to room‐air controls. We verified using carbamazepine (CBZ, 20µM, 6hrs) that eCV induced changes in ub‐accumulation, proteasomal activity, autophagy, apoptosis and senescence could all be controlled by autophagy induction by CBZ. We further confirmed the role of acute eCV‐exposure on autophagy impairment in murine lungs (C57BL/6 and CD1) by IB (ub, p62, VCP) and IP (VCP, p62) similar to in‐vitro experiments. Conclusion eCV induced autophagy impairment and aggresome‐formation activates apoptosis/senescence suggesting its potential role in COPD‐emphysema pathogenesis.