Chaperone-Mediated Autophagy Suppresses Apoptosis via Regulation of the Unfolded Protein Response during Chronic Obstructive Pulmonary Disease Pathogenesis.
Abstract
Cigarette smoke (CS) induces accumulation of misfolded proteins with concomitantly enhanced unfolded protein response (UPR). Increased apoptosis linked to UPR has been demonstrated in chronic obstructive pulmonary disease (COPD) pathogenesis. Chaperone-mediated autophagy (CMA) is a type of selective autophagy for lysosomal degradation of proteins with the KFERQ peptide motif. CMA has been implicated in not only maintaining nutritional homeostasis but also adapting the cell to stressed conditions. Although recent papers have shown functional cross-talk between UPR and CMA, mechanistic implications for CMA in COPD pathogenesis, especially in association with CS-evoked UPR, remain obscure. In this study, we sought to examine the role of CMA in regulating CS-induced apoptosis linked to UPR during COPD pathogenesis using human bronchial epithelial cells (HBEC) and lung tissues. CS extract (CSE) induced LAMP2A expression and CMA activation through a Nrf2-dependent manner in HBEC. LAMP2A knockdown and the subsequent CMA inhibition enhanced UPR, including CHOP expression, and was accompanied by increased apoptosis during CSE exposure, which was reversed by LAMP2A overexpression. Immunohistochemistry showed that Nrf2 and LAMP2A levels w...Continue Reading
References
Citations
Related Concepts
Related Feeds
Autophagy & Model Organisms
Autophagy is a cellular process that allows degradation by the lysosome of cytoplasmic components such as proteins or organelles. Here is the latest research on autophagy & model organisms
Apoptosis
Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis