scholarly journals Hydrogen sulphide reduces hyperhomocysteinaemia‐induced endothelial ER stress by sulfhydrating protein disulphide isomerase to attenuate atherosclerosis

2021 ◽  
Vol 25 (7) ◽  
pp. 3437-3448
Author(s):  
Shan Jiang ◽  
Wenjing Xu ◽  
Zhenzhen Chen ◽  
Changting Cui ◽  
Xiaofang Fan ◽  
...  
Keyword(s):  
Er Stress ◽  
Hydrogen Sulphide ◽  
Protein Disulphide Isomerase

scholarly journals Protein Disulphide Isomerase 6 (PDIA6) Attenuates Platelet Endoplasmic Reticulum Stress and Secretion in a Mouse Model

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3138-3138
Author(s):  
Freda H. Passam ◽  
Angelina Lay ◽  
Alexander Dupuy ◽  
Jessica Tieng ◽  
Lejla Hagimola ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Platelet Aggregation ◽  
Carotid Artery ◽  
Western Blot ◽  
Er Stress ◽  
Platelet Factor ◽  
Platelet Surface ◽  
Protein Disulphide Isomerase ◽  
Obesity And Diabetes ◽  
Granule Proteins

Abstract Background: Platelet hyperreactivity involves increased secretion of their granule content which promotes platelet aggregation and thrombosis. Platelet hyperreactivity is observed in conditions such as diabetes mellitus and is associated with decreased cardioprotective effect from antiplatelet agents in this patient group. Diabetes is associated with increased endoplasmic reticulum (ER) stress from hyperglycemia and hyperlipidemia. Protein disulphide isomerase 6 (PDIA6) is an endoplasmic reticulum protein which folds nascent proteins by reduction and oxidation of their disulphide bonds. PDIA6 has been shown to inhibit downstream ER stress pathways by inhibiting the phosphorylation of IRE-1 in fibroblasts (Eletto, Mol Cell, 2014). We hypothesized that ER stress pathways are functional in platelets and that PDIA6 may inhibit ER stress pathways leading to platelet secretion. Methods: We generated conditional PDIA6 knockout mice (PF4Cre+ Pdia6 fl/fl) (CKO) in the megakaryocyte/platelet lineage by CRISPR-Cas9 technology (Fig.1A). Megakaryopoiesis and haemostasis was assessed by bone marrow histology, coagulation assays, platelet aggregation and tail bleeding studies. We induced ER stress of purified platelets by incubation with thapsigargin and tunicamycin. Activation of the PERK and IRE1 pathways was measured by Western blot. Thrombosis was assessed in vitro by microfluidic devices and in vivo by electrolytic injury of the carotid artery. Results: PDIA6 CKO mice displayed a mild macrothrombocytopenia: the mean (+/-SD) platelet count in Pf4Cre+/Pdia6fl/fl was 775 +/- 98 x10 3/ul compared with 874 +/- 55 x10 3/ul in Pdia6fl/fl (p<0.005). The median platelet volume was 6.3 fL in Pf4Cre+/Pdia6fl/fl compared with 5.7 fL in Pdia6fl/fl (p<0.005). Megakaryopoiesis was normal at baseline. However, PDIA6 CKO mice showed significant upregulation of intracellular platelet PDIs including PDIA1, PDIA3 and PDIA4. PDIA6 deficient platelets displayed significant increase of disulphide reductase activity and the generation of free thiols on the platelet surface. Activation of the PERK and IRE-1 pathway at baseline and after induction of ER stress was increased in PDIA6 deficient platelets (Figure 1B, C). There was striking hypersecretion of PDIA1 (Figure 1D) and α-granule proteins (Figure 1E, F) in response to shear and stimulation with thrombin. PDIA6 CKO mice displayed a prothrombotic phenotype with increased platelet adhesion to fibrinogen under shear (500 s-1) and decreased time to carotid artery occlusion (mean+/SD: 10.8 +/-3.2 min in Pf4Cre+/Pdia6fl/fl compared with 15.3 +/-5.2 min in Pdia6fl/fl, n=8-10, p<0.05). Conclusion: We have identified a role for platelet PDIA6 in attenuating platelet ER stress and secretion. This opens avenues for further study into the role of platelet PDIs in conditions with increased ER stress, such as obesity and diabetes. Figure 1: PDIA6 deficient platelets have increased endoplasmic reticulum (ER) stress and are hypersecretory. A. Western blot of PDIA6 protein in platelets from Pf4Cre+/Pdia6fl/fl mice and control mice (Pdia6fl/fl) showing efficient deletion of PDIA6 in platelets. B. PDIA6 deficient platelets have increased phosphorylation of pEIF2a (PERK phosphorylation pathway) at baseline and after induction of ER stress by thapsigargin, representative image. C. Normalized band intensity (peIF2a/beta actin) in platelets treated with DMSO control or thapsigargin. D. Increased secretion of thiol isomerase PDIA1. E. alpha granule proteins: platelet factor 4 (PF4) and F. von Willebrand factor (vWF) from PDIA6 deficient platelets compared with controls after stimulation with thrombin 0.5 U/ml. n=3-5 Pf4Cre+/Pdia6fl/fl (red boxes) and n=3-5 Pdia6fl/fl mice (grey boxes). Columns are presented as mean+/-SD, *p<0.05, ** p<0.001 by Mann Whitney. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Protein disulphide isomerase (PDI) is protective against amyotrophic lateral sclerosis (ALS)-related mutant Fused in Sarcoma (FUS) in in vitro models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Parakh ◽  
E. R. Perri ◽  
M. Vidal ◽  
J. Sultana ◽  
S. Shadfar ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Er Stress ◽  
Protein Import ◽  
Primary Cultures ◽  
Neuronal Cell ◽  
Nucleocytoplasmic Transport ◽  
Protein Disulphide Isomerase ◽  
Fused In Sarcoma ◽  
Lateral Sclerosis

AbstractMutations in Fused in Sarcoma (FUS) are present in familial and sporadic cases of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). FUS is localised in the nucleus where it has important functions in DNA repair. However, in ALS/FTD, mutant FUS mislocalises from the nucleus to the cytoplasm where it forms inclusions, a key pathological hallmark of neurodegeneration. Mutant FUS also inhibits protein import into the nucleus, resulting in defects in nucleocytoplasmic transport. Fragmentation of the neuronal Golgi apparatus, induction of endoplasmic reticulum (ER) stress, and inhibition of ER-Golgi trafficking are also associated with mutant FUS misfolding in ALS. Protein disulphide isomerase (PDI) is an ER chaperone previously shown to be protective against misfolding associated with mutant superoxide dismutase 1 (SOD1) and TAR DNA-binding protein-43 (TDP-43) in cellular and zebrafish models. However, a protective role against mutant FUS in ALS has not been previously described. In this study, we demonstrate that PDI is protective against mutant FUS. In neuronal cell line and primary cultures, PDI restores defects in nuclear import, prevents the formation of mutant FUS inclusions, inhibits Golgi fragmentation, ER stress, ER-Golgi transport defects, and apoptosis. These findings imply that PDI is a new therapeutic target in FUS-associated ALS.

Protein disulphide-isomerase A2 regulated intracellular tissue factor mobilisation in migrating human vascular smooth muscle cells

2015 ◽  
Vol 113 (04) ◽  
pp. 891-902 ◽  
Author(s):  
Esther Peña ◽  
Gemma Arderiu ◽  
Lina Badimon
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Er Stress ◽  
Tissue Factor ◽  
Stress Protein ◽  
Muscle Cells ◽  
Small Interfering Rnas ◽  
Protein Disulphide Isomerase

SummaryProtein-disulphide isomerase family (PDI) are an ER-stress protein that controls TF-procoagulant activity but its role in HVSMC migration and coronary artery disease remains to be elucidated. We aimed to investigate whether in human coronary smooth muscle cells (HVSMC) the ER-stress protein-disulphide isomerase family A member 2 (PDIA2) regulates tissue factor (TF) polarisation during migration and atherosclerotic remodeling. PDIA2 and TF were analysed by confocal microscopy, silenced by small interfering RNAs (siRNA) and their function analysed by transwell and migration assays in vitro and in vivo. PDIA2and TF co-localise in the front edge of motile HVSMC. Silencing PDIA2, as well as silencing TF, reduces migration. PDIA2 silenced cells show increased TF-rich microparticle shedding. In vivo cell-loaded plug implants in nude mice of PDIA2 silenced HVSMC together with microvascular endothelial cells showed a significant impairment in mature microvessel formation. PDIA2 and TF are found in remodelled atherosclerotic plaques but not in healthy coronaries. In conclusion, we demonstrate that TF is chaperoned by PDIA2 to the HVSMC membrane and to the cell migratory front. Absence of PDIA2 impairs TF intracellular trafficking to its membrane docking favoring its uncontrolled release in microparticles. TF-regulated HVSMC migration and microvessel formation is under the control of the ER-protein PDIA2.

scholarly journals The Role of S-Nitrosylation and S-Glutathionylation of Protein Disulphide Isomerase in Protein Misfolding and Neurodegeneration

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
M. Halloran ◽  
S. Parakh ◽  
J. D. Atkin
Keyword(s):  
Neurodegenerative Diseases ◽  
Er Stress ◽  
Protein Misfolding ◽  
Molecular Mechanisms ◽  
Nitrosative Stress ◽  
Therapeutic Interventions ◽  
Oxidative And Nitrosative Stress ◽  
Protective Function ◽  
Protein Disulphide Isomerase

Neurodegenerative diseases involve the progressive loss of neurons, and a pathological hallmark is the presence of abnormal inclusions containing misfolded proteins. Although the precise molecular mechanisms triggering neurodegeneration remain unclear, endoplasmic reticulum (ER) stress, elevated oxidative and nitrosative stress, and protein misfolding are important features in pathogenesis. Protein disulphide isomerase (PDI) is the prototype of a family of molecular chaperones and foldases upregulated during ER stress that are increasingly implicated in neurodegenerative diseases. PDI catalyzes the rearrangement and formation of disulphide bonds, thus facilitating protein folding, and in neurodegeneration may act to ameliorate the burden of protein misfolding. However, an aberrant posttranslational modification of PDI, S-nitrosylation, inhibits its protective function in these conditions. S-nitrosylation is a redox-mediated modification that regulates protein function by covalent addition of nitric oxide- (NO-) containing groups to cysteine residues. Here, we discuss the evidence for abnormal S-nitrosylation of PDI (SNO-PDI) in neurodegeneration and how this may be linked to another aberrant modification of PDI, S-glutathionylation. Understanding the role of aberrant S-nitrosylation/S-glutathionylation of PDI in the pathogenesis of neurodegenerative diseases may provide insights into novel therapeutic interventions in the future.

scholarly journals Mechanisms of Neuroprotection by Protein Disulphide Isomerase in Amyotrophic Lateral Sclerosis

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Adam K. Walker ◽  
Julie D. Atkin
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Er Stress ◽  
Motor Neurons ◽  
Protein Misfolding ◽  
Active Role ◽  
Model Organisms ◽  
Central Feature ◽  
Human Patient ◽  
Protein Disulphide Isomerase ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterised by the progressive loss of motor neurons, leading to paralysis and death within several years of onset. Although protein misfolding is a key feature of ALS, the upstream triggers of disease remain elusive. Recently, endoplasmic reticulum (ER) stress was identified as an early and central feature in ALS disease models as well as in human patient tissues, indicating that ER stress could be an important process in disease pathogenesis. One important chaperone induced by ER stress is protein disulphide isomerase (PDI), which is both upregulated and posttranslationally inhibited by S-nitrosylation in ALS. In this paper, we present evidence from studies of genetics, model organisms, and patient tissues which indicate an active role for PDI and ER stress in ALS disease processes.

Induction of ER stress by variants of the prohormone convertase 1 (PCSK1)-gene

2013 ◽  
Vol 8 (S 01) ◽  
Author(s):  
S Behrendt ◽  
D Löffler ◽  
R Tauscher ◽  
A Körner
Keyword(s):  
Er Stress ◽  
Prohormone Convertase ◽  
Prohormone Convertase 1 ◽  
Pcsk1 Gene

Oleate rescues INS-1E β-cells from palmitate-induced ER-stress through a reduced phosphorylation of eIF2α

2013 ◽  
Vol 8 (S 01) ◽  
Author(s):  
D Sommerweiss ◽  
T Gorski ◽  
S Laue ◽  
S Schuster ◽  
A Garten ◽  
...  
Keyword(s):  
Er Stress ◽  
Β Cells

Effects of hydrogen sulphide on heme oxigenase activity in TNBS induced colitis

2014 ◽  
Vol 52 (05) ◽  
Author(s):  
K Kupai ◽  
Z Szalai ◽  
M Korsós ◽  
Z Baráth ◽  
S Török ◽  
...  
Keyword(s):  
Hydrogen Sulphide
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