LAMP3 inhibits autophagy and contributes to cell death by lysosomal membrane permeabilization

作者：Tsutomu Tanaka, Blake M. Warner, Drew G. Michael, Hiroyuki Nakamura, Toshio Odani, Hongen Yin, Tatsuya Atsumi, Masayuki Noguchi, John A. Chiorini · 发表于：Autophagy · 年份：2021 · DOI：10.1080/15548627.2021.1995150 · 被引用次数：120 · 研究领域：Autophagy in Disease and Therapy、Endoplasmic Reticulum Stress and Disease、Lysosomal Storage Disorders Research

Sjögren syndrome (SS) is a chronic and progressive autoimmune disease characterized by dry mouth and dry eyes, and characteristic autoantibodies. Evidence of altered macroautophagy/autophagy and apoptosis has been associated with SS, but a mechanistic understanding of the gene expression changes associated with these abnormal processes has not been realized. Recently, increased LAMP3 (lysosomal associated membrane protein 3) expression was found in a subset of SS patients and was associated with increased apoptosis and autoantigen accumulation and release. To better understand how LAMP3 expression might modulate apoptosis, cell biology, and biochemical studies were used to examine the effect of LAMP3 expression in minor salivary gland cells. LAMP3 expression resulted in degradation of LAMP1 increasing lysosomal membrane permeabilization and relocalization of cathepsins to the cytoplasm, resulting in destabilizing autophagic flux and caspase activation. These findings highlight the central role of LAMP3 expression in the pathogenesis of SS.Abbreviations A253-control: A253 control for LAMP3 stable overexpression; A253- LAMP3: A253 LAPM3 stable overexpression; CASP1: caspase 1; CASP3: caspase 3; CHX: cycloheximide; CTSB: cathepsin B; CTSD: cathepsin D; CQ: chloroquine; DCs: dendritic cells; ER: endoplasmic reticulum; LGALS3: galectin 3; HCV: hepatitis C virus; HSG-control: HSG control for LAMP3 stable overexpression; HSG-LAMP3: HSG LAMP3 stable overexpression; HSP: heat shock pr...