scholarly journals Endoplasmic Reticulum (ER) Stress and Unfolded Protein Response (UPR) in Mammalian Oocyte Maturation and Preimplantation Embryo Development

2019 ◽  
Vol 20 (2) ◽  
pp. 409 ◽  
Author(s):  
Tao Lin ◽  
Jae Lee ◽  
Jung Kang ◽  
Hyeon Shin ◽  
Ju Lee ◽  
...  

Mammalian oocytes and early embryos derived from in vitro production are highly susceptible to a variety of cellular stresses. During oocyte maturation and preimplantation embryo development, functional proteins must be folded properly in the endoplasmic reticulum (ER) to maintain oocyte and embryo development. However, some adverse factors negatively impact ER functions and protein synthesis, resulting in the activation of ER stress and unfolded protein response (UPR) signaling pathways. ER stress and UPR signaling have been identified in mammalian oocytes and embryos produced in vitro, suggesting that modulation of ER stress and UPR signaling play very important roles in oocyte maturation and the development of preimplantation embryos. In this review, we briefly describe the current state of knowledge regarding ER stress, UPR signaling pathways, and their roles and mechanisms in mammalian (excluding human) oocyte maturation and preimplantation embryo development.

2009 ◽  
Vol 20 (5) ◽  
pp. 1493-1508 ◽  
Author(s):  
Shi-Xiong Tan ◽  
Mariati Teo ◽  
Yuen T. Lam ◽  
Ian W. Dawes ◽  
Gabriel G. Perrone

Genome-wide screening for sensitivity to chronic endoplasmic reticulum (ER) stress induced by dithiothreitol and tunicamycin (TM) identified mutants deleted for Cu, Zn superoxide dismutase (SOD) function (SOD1, CCS1) or affected in NADPH generation via the pentose phosphate pathway (TKL1, RPE1). TM-induced ER stress led to an increase in cellular superoxide accumulation and an increase in SOD1 expression and Sod1p activity. Prior adaptation of the hac1 mutant deficient in the unfolded protein response (UPR) to the superoxide-generating agent paraquat reduced cell death under ER stress. Overexpression of the ER oxidoreductase Ero1p known to generate hydrogen peroxide in vitro, did not lead to increased superoxide levels in cells subjected to ER stress. The mutants lacking SOD1, TKL1, or RPE1 exhibited decreased UPR induction under ER stress. Sensitivity of the sod1 mutant to ER stress and decreased UPR induction was partially rescued by overexpression of TKL1 encoding transketolase. These data indicate an important role for SOD and cellular NADP(H) in cell survival during ER stress, and it is proposed that accumulation of superoxide affects NADP(H) homeostasis, leading to reduced UPR induction during ER stress.


2011 ◽  
Vol 286 (22) ◽  
pp. 20020-20030 ◽  
Author(s):  
Murilo S. Alves ◽  
Pedro A. B. Reis ◽  
Silvana P. Dadalto ◽  
Jerusa A. Q. A. Faria ◽  
Elizabeth P. B. Fontes ◽  
...  

As in all other eukaryotic organisms, endoplasmic reticulum (ER) stress triggers the evolutionarily conserved unfolded protein response in soybean, but it also communicates with other adaptive signaling responses, such as osmotic stress-induced and ER stress-induced programmed cell death. These two signaling pathways converge at the level of gene transcription to activate an integrated cascade that is mediated by N-rich proteins (NRPs). Here, we describe a novel transcription factor, GmERD15 (Glycine max Early Responsive to Dehydration 15), which is induced by ER stress and osmotic stress to activate the expression of NRP genes. GmERD15 was isolated because of its capacity to stably associate with the NRP-B promoter in yeast. It specifically binds to a 187-bp fragment of the NRP-B promoter in vitro and activates the transcription of a reporter gene in yeast. Furthermore, GmERD15 was found in both the cytoplasm and the nucleus, and a ChIP assay revealed that it binds to the NRP-B promoter in vivo. Expression of GmERD15 in soybean protoplasts activated the NRP-B promoter and induced expression of the NRP-B gene. Collectively, these results support the interpretation that GmERD15 functions as an upstream component of stress-induced NRP-B-mediated signaling to connect stress in the ER to an osmotic stress-induced cell death signal.


2020 ◽  
Vol 21 (21) ◽  
pp. 8177
Author(s):  
Nataša Pavlović ◽  
Maria Kopsida ◽  
Pär Gerwins ◽  
Femke Heindryckx

The P2Y12 receptor is an adenosine diphosphate responsive G protein-coupled receptor expressed on the surface of platelets and is the pharmacologic target of several anti-thrombotic agents. In this study, we use liver samples from mice with cirrhosis and hepatocellular carcinoma to show that P2Y12 is expressed by macrophages in the liver. Using in vitro methods, we show that inhibition of P2Y12 with ticagrelor enhances tumor cell phagocytosis by macrophages and induces an anti-tumoral phenotype. Treatment with ticagrelor also increases the expression of several actors of the endoplasmic reticulum (ER) stress pathways, suggesting activation of the unfolded protein response (UPR). Inhibiting the UPR with tauroursodeoxycholic acid (Tudca) diminishes the pro-phagocytotic effect of ticagrelor, thereby indicating that P2Y12 mediates macrophage function through activation of ER stress pathways. This could be relevant in the pathogenesis of chronic liver disease and cancer, as macrophages are considered key players in these inflammation-driven pathologies.


2015 ◽  
Vol 6 (10) ◽  
pp. 3275-3281 ◽  
Author(s):  
Elena Giordano ◽  
Olivier Dangles ◽  
Njara Rakotomanomana ◽  
Silvia Baracchini ◽  
Francesco Visioli

Endoplasmic reticulum (ER) stress is important for atherosclerosis development and is mediated by the unfolded protein response (UPR).


2016 ◽  
Vol 397 (7) ◽  
pp. 649-656 ◽  
Author(s):  
Alexander R. van Vliet ◽  
Abhishek D. Garg ◽  
Patrizia Agostinis

AbstractThe endoplasmic reticulum (ER) is the main coordinator of intracellular Ca2+signaling, protein synthesis, and folding. The ER is also implicated in the formation of contact sites with other organelles and structures, including mitochondria, plasma membrane (PM), and endosomes, thereby orchestrating through interorganelle signaling pathways, a variety of cellular responses including Ca2+homeostasis, metabolism, and cell death signaling. Upon loss of its folding capacity, incited by a number of stress signals including those elicited by various anticancer therapies, the unfolded protein response (UPR) is launched to restore ER homeostasis. The ER stress sensor protein kinase RNA-like ER kinase (PERK) is a key mediator of the UPR and its role during ER stress has been largely recognized. However, growing evidence suggests that PERK may govern signaling pathways through UPR-independent functions. Here, we discuss emerging noncanonical roles of PERK with particular relevance for the induction of danger or immunogenic signaling and interorganelle communication.


2019 ◽  
Vol 101 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Megan Lim ◽  
Hannah M Brown ◽  
Karen L Kind ◽  
Jeremy G Thompson ◽  
Kylie R Dunning

Abstract Hemoglobin (Hb) is commonly known for its capacity to bind and transport oxygen and carbon dioxide in erythroid cells. However, it plays additional roles in cellular function and health due to its capacity to bind other gases including nitric oxide. Further, Hb acts as a potent antioxidant, quenching reactive oxygen species. Despite its potential roles in cellular function, the preponderance of Hb research remains focused on its role in oxygen regulation. There is increasing evidence that Hb expression is more ubiquitous than previously thought, with Hb and its variants found in a myriad of cell types ranging from macrophages to spermatozoa. The majority of nonerythroid cell types that express Hb are situated within hypoxic environments, suggesting Hb may play a role in hypoxia-inducible factor-regulated gene expression by controlling the level of oxygen available or as an adaptation to low oxygen providing a mechanism to store oxygen. Oocyte maturation and preimplantation embryo development occur within the low oxygen environments of the antral follicle and oviduct/uterus, respectively. Interestingly, Hb was recently found in human cumulus and granulosa cells and murine cumulus–oocyte complexes and preimplantation embryos. Here, we consolidate and analyze the research generated todate on Hb expression in nonerythroid cells with a particular focus on reproductive cell types. We outline future directions of this research to elucidate the role of Hb during oocyte maturation and preimplantation embryo development and finally, we explore the potential clinical applications and benefits of Hb supplementation during the in vitro culture of gametes and embryos.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adrien Le Thomas ◽  
Elena Ferri ◽  
Scot Marsters ◽  
Jonathan M. Harnoss ◽  
David A. Lawrence ◽  
...  

AbstractInositol requiring enzyme 1 (IRE1) mitigates endoplasmic-reticulum (ER) stress by orchestrating the unfolded-protein response (UPR). IRE1 spans the ER membrane, and signals through a cytosolic kinase-endoribonuclease module. The endoribonuclease generates the transcription factor XBP1s by intron excision between similar RNA stem-loop endomotifs, and depletes select cellular mRNAs through regulated IRE1-dependent decay (RIDD). Paradoxically, in mammals RIDD seems to target only mRNAs with XBP1-like endomotifs, while in flies RIDD exhibits little sequence restriction. By comparing nascent and total IRE1α-controlled mRNAs in human cells, we identify not only canonical endomotif-containing RIDD substrates, but also targets without such motifs—degraded by a process we coin RIDDLE, for RIDD lacking endomotif. IRE1α displays two basic endoribonuclease modalities: highly specific, endomotif-directed cleavage, minimally requiring dimers; and more promiscuous, endomotif-independent processing, requiring phospho-oligomers. An oligomer-deficient IRE1α mutant fails to support RIDDLE in vitro and in cells. Our results advance current mechanistic understanding of the UPR.


2018 ◽  
Vol 47 (04) ◽  
pp. 664-675 ◽  
Author(s):  
Elisabeth Andersen ◽  
Maria Chollet ◽  
Christiane Myklebust ◽  
Mirko Pinotti ◽  
Francesco Bernardi ◽  
...  

AbstractCongenital factor (F) VII deficiency is a bleeding disorder caused by a heterogeneous pattern of mutations in the F7 gene. Protein misfolding due to mutations is a strong candidate mechanism to produce the highly represented type I FVII deficiency forms, characterized by a concomitant deficiency of FVII antigen and activity. Misfolded proteins can accumulate within the endoplasmic reticulum (ER) causing ER stress with subsequent activation of the unfolded protein response (UPR). So far, there are limited data on this important issue in FVII deficiency. In this study, we chose as candidate FVII model mutations, the p.Q160R, p.I289del and p.A354V-p.P464Hfs, which are all associated with severe to moderate type I FVII deficiency. In vitro expression of the recombinant (r) mutants rFVII-160R, rFVII-289del or rFVII-354V-464Hfs, which are characterized by either amino acid substitution, deletion, or by an extended carboxyl terminus, demonstrated inefficient secretion of the mutant proteins, probably caused by intracellular retention and association with ER chaperones. Both ER stress and UPR were activated following expression of all FVII mutants, with the highest response for rFVII-289del and rFVII-354V-464Hfs. These data unravel new knowledge on pathogenic mechanisms leading to FVII deficiency, and support the investigation of pharmaceutical modulators of ER stress and UPR as therapeutic agents.


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