Endoplasmic Reticulum Stress Signaling in Disease

2006 ◽  
Vol 86 (4) ◽  
pp. 1133-1149 ◽  
Author(s):  
Stefan J. Marciniak ◽  
David Ron

The extracellular space is an environment hostile to unmodified polypeptides. For this reason, many eukaryotic proteins destined for exposure to this environment through secretion or display at the cell surface require maturation steps within a specialized organelle, the endoplasmic reticulum (ER). A complex homeostatic mechanism, known as the unfolded protein response (UPR), has evolved to link the load of newly synthesized proteins with the capacity of the ER to mature them. It has become apparent that dysfunction of the UPR plays an important role in some human diseases, especially those involving tissues dedicated to extracellular protein synthesis. Diabetes mellitus is an example of such a disease, since the demands for constantly varying levels of insulin synthesis make pancreatic β-cells dependent on efficient UPR signaling. Furthermore, recent discoveries in this field indicate that the importance of the UPR in diabetes is not restricted to the β-cell but is also involved in peripheral insulin resistance. This review addresses aspects of the UPR currently understood to be involved in human disease, including their role in diabetes mellitus, atherosclerosis, and neoplasia.

2016 ◽  
Vol 57 (1) ◽  
pp. R1-R17 ◽  
Author(s):  
Kira Meyerovich ◽  
Fernanda Ortis ◽  
Florent Allagnat ◽  
Alessandra K Cardozo

Insulin-secreting pancreatic β-cells are extremely dependent on their endoplasmic reticulum (ER) to cope with the oscillatory requirement of secreted insulin to maintain normoglycemia. Insulin translation and folding rely greatly on the unfolded protein response (UPR), an array of three main signaling pathways designed to maintain ER homeostasis and limit ER stress. However, prolonged or excessive UPR activation triggers alternative molecular pathways that can lead to β-cell dysfunction and apoptosis. An increasing number of studies suggest a role of these pro-apoptotic UPR pathways in the downfall of β-cells observed in diabetic patients. Particularly, the past few years highlighted a cross talk between the UPR and inflammation in the context of both type 1 (T1D) and type 2 diabetes (T2D). In this article, we describe the recent advances in research regarding the interplay between ER stress, the UPR, and inflammation in the context of β-cell apoptosis leading to diabetes.


2005 ◽  
Vol 280 (47) ◽  
pp. 39609-39615 ◽  
Author(s):  
Sonya G. Fonseca ◽  
Mariko Fukuma ◽  
Kathryn L. Lipson ◽  
Linh X. Nguyen ◽  
Jenny R. Allen ◽  
...  

Endocrinology ◽  
2021 ◽  
Vol 162 (11) ◽  
Author(s):  
Michael A Kalwat ◽  
Donalyn Scheuner ◽  
Karina Rodrigues-dos-Santos ◽  
Decio L Eizirik ◽  
Melanie H Cobb

Abstract Pancreatic β cells dedicate much of their protein translation capacity to producing insulin to maintain glucose homeostasis. In response to increased secretory demand, β cells can compensate by increasing insulin production capability even in the face of protracted peripheral insulin resistance. The ability to amplify insulin secretion in response to hyperglycemia is a critical facet of β-cell function, and the exact mechanisms by which this occurs have been studied for decades. To adapt to the constant and fast-changing demands for insulin production, β cells use the unfolded protein response of the endoplasmic reticulum. Failure of these compensatory mechanisms contributes to both type 1 and 2 diabetes. Additionally, studies in which β cells are “rested” by reducing endogenous insulin demand have shown promise as a therapeutic strategy that could be applied more broadly. Here, we review recent findings in β cells pertaining to the metabolic amplifying pathway, the unfolded protein response, and potential advances in therapeutics based on β-cell rest.


2019 ◽  
Vol 11 (4) ◽  
pp. 375-390 ◽  
Author(s):  
Maikel L. Colli ◽  
Flavia M. Paula ◽  
Lorella Marselli ◽  
Piero Marchetti ◽  
Merja Roivainen ◽  
...  

Type 1 diabetes (T1D) is an autoimmune disease characterized by islet inflammation and progressive pancreatic β cell destruction. The disease is triggered by a combination of genetic and environmental factors, but the mechanisms leading to the triggering of early innate and late adaptive immunity and consequent progressive pancreatic β cell death remain unclear. The insulin-producing β cells are active secretory cells and are thus particularly sensitive to endoplasmic reticulum (ER) stress. ER stress plays an important role in the pathologic pathway leading to autoimmunity, islet inflammation, and β cell death. We show here that group B coxsackievirus (CVB) infection, a putative causative factor for T1D, induces a partial ER stress in rat and human β cells. The activation of the PERK/ATF4/CHOP branch is blunted while the IRE1α branch leads to increased spliced XBP1 expression and c-Jun N-terminal kinase (JNK) activation. Interestingly, JNK1 activation is essential for CVB amplification in both human and rat β cells. Furthermore, a chemically induced ER stress preceding viral infection increases viral replication, in a process dependent on IRE1α activation. Our findings show that CVB tailors the unfolded protein response in β cells to support their replication, preferentially triggering the pro-viral IRE1α/XBP1s/JNK1 pathway while blocking the pro-apoptotic PERK/ATF4/CHOP pathway.


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