Z α-1 antitrypsin deficiency and the endoplasmic reticulum stress response

• 作者: Catherine M Greene Noel G McElvaney
• 来源期刊: 世界胃肠药理与治疗学杂志：英文版（电子版）
• 学科: 医学
• 关键词: α-1 ANTITRYPSIN Unfolded protein response Endoplasmic reticulum stress APOPTOSIS AUTOPHAGY NFΚB
• 年，卷（期）: 2010,（5）
• 页码范围: 94-101
• 页数: 8页
• 分类号: R341

摘要

The serine proteinase inhibitor α-1 antitrypsin(AAT) is produced principally by the liver at the rate of 2 g/d.It is secreted into the circulation and provides an antiprotease protective screen throughout the body but most importantly in the lung,where it can neutralise the activity of the serine protease neutrophil elastase.Mutations leading to def iciency in AAT are associated with liver and lung disease.The most notable is the Z AAT mutation,which encodes a misfolded variant of the AAT protein in which the glutamic acid at position 342 is replaced by a lysine.More than 95% of all individuals with AAT def iciency carry at least one Z allele.ZAAT protein is not secreted effectively and accumulates intracellularly in the endoplasmic reticulum(ER) of hepatocytes and other AAT-producing cells.This results in a loss of function associated with decreased circulating and intrapulmonary levels of AAT.However,the misfolded protein acquires a toxic gain of function that impacts on the ER.A major function of the ER is to ensure correct protein folding.ZAAT interferes with this function and promotes ER stress responses and inflammation.Here the signalling pathways activated during ER stress in response to accumulation of ZAAT are described and therapeutic strategies that can potentially relieve ER stress are discussed.