Abstract 264: Protein Disulfide Isomerase A1 is a Central Hub for Redox Regulation of VSMC Phenotype

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Joao Wosniak ◽  
Renata C Gonçalves ◽  
Leonardo Y Tanaka ◽  
Daniela B Zanatta ◽  
Bryan E Strauss ◽  
...  
Keyword(s):  
Protein Disulfide Isomerase ◽  
Redox Regulation ◽  
Lentiviral Vector ◽  
Ex Vivo ◽  
Mrna Levels ◽  
Disulfide Isomerase ◽  
Cytoskeleton Organization ◽  
Anisotropy Index ◽  
Differentiation Marker ◽  
Protein Disulfide

Objective: Vascular smooth muscle cell (VSMC) phenotype switch depends on extrinsic/intrinsic cues including NOX NADPH oxidase-linked redox signaling. Growth factor-triggered NOX1 expression/activity requires the chaperone oxidoreductase protein disulfide isomerase-A1 (PDI). Acute PDI overexpression induces agonist-independent NOX1 expression. PDI is required for VSMC migration and cytoskeleton organization, and extracellular PDI supports expansive vascular remodeling via cytoskeleton reshaping. Such PDI effects led us to hypothesize that PDI may orchestrate VSMC phenotypic alterations. Approach and Results: In primary VSMC, PDI silencing spontaneously decreased differentiation marker expression. Transfection with a doxycycline-inducible lentiviral vector encoding PDI showed that sustained PDI overexpression (72h) enhanced actin branching pattern vs. baseline (anisotropy index, 0.103±0.019 vs. 0.220±0.027, 72h vs. 0h, mean±SEM, N=5, P<0.05), increased cell length and induced expression of differentiation marker calponin (2-fold, 72h vs 0h, N=5, P<0.05), alpha-actin and smoothelin, which were abrogated upon catalase incubation. Intracellular superoxide enhanced upon 48h of PDI overexpression (2-hydroxyethidium levels, 0.998±0.102 vs. 2.887±0.227 AU, N=4, P<0.05) and was NOX1-dependent, based on inhibition with GKT136901 (by 48%) or NOXA1ds peptide (by 54%) (N=6, P<0.05). Increased NOX1 mRNA occurred early after PDI overexpression (74%, 24h vs. 0h, N=4, P<0.05), while NOX4 mRNA was upregulated only after long-term PDI induction (100%, 72h vs. 0h, N=4, P<0.05). In rabbit restenosis model exhibiting strong PDI upregulation (12-fold at day 14 after injury), ex vivo PDI silencing 7 or 14 days after injury reversed PCNA expression, while promoting increased NOX1 and decreased NOX4 mRNA levels (+54% and -45%, respectively, siPDI vs. siSCR, N=3, P<0.05 for both). Conclusions: While short-term PDI overexpression supports NOX1 activation/expression, sustained PDI overexpression drives NOX4 expression and VSMC differentiation. Effects on cytoskeleton, NOX1/4 activation and temporal control of NOX1/4 expression suggest a central role for PDI as a hub for redox-mediated VSMC phenotype regulation.

scholarly journals Redox Regulation of Mitochondrial Fission Protein Drp1 by Protein Disulfide Isomerase Limits Endothelial Senescence

Cell Reports ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3565-3578 ◽  
Author(s):  
Young-Mee Kim ◽  
Seock-Won Youn ◽  
Varadarajan Sudhahar ◽  
Archita Das ◽  
Reyhaan Chandhri ◽  
...  
Keyword(s):  
Protein Disulfide Isomerase ◽  
Redox Regulation ◽  
Mitochondrial Fission ◽  
Disulfide Isomerase ◽  
Protein Disulfide

scholarly journals Activation of the Mineralocorticoid Receptor Stimulates Protein Disulfide Isomerase: Role in Sickle Cell Disease

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1351-1351
Author(s):  
Alexandra Lozano ◽  
Christopher Vega ◽  
Yaritza Inostroza-Nieves ◽  
Lorena Rivera González ◽  
Pablo J. López ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Protein Disulfide Isomerase ◽  
Mineralocorticoid Receptor ◽  
Conflicts Of Interest ◽  
Hematological Parameters ◽  
Control Diet ◽  
Mrna Levels ◽  
Disulfide Isomerase ◽  
Qrt Pcr ◽  
Protein Disulfide

Abstract Activation of the mineralocorticoid receptor (MR), a critical component of the Renin-Angiotensin-Aldosterone (ALDO)-System (RAAS), has been shown to play an important role in inflammatory and vascular endothelial responses in addition to its well-described effects on sodium and water homeostasis. Activationof endothelial cells leads to, among other factors, increased endothelin-1 (ET-1) and protein disulfide isomerase (PDI) release. PDI and ET-1 contribute to vascular inflammation and are increased in patients with SCD and sickle transgenic mouse models. The MR is a member of the steroid family of nuclear receptors and transcription factors that upon activation binds to hormone response elements of edn1, the gene for ET-1, leading to increased ET-1 expression.In vivo, blockade of MR has been shown to reduce circulating ET-1 levels and ET-1 mRNA expression. However, the role of MR in SCD is unclear. We hypothesized that MR blockade in sickle transgenic mice would reduce PDI activity and improve hematological parameters and inflammation. We first studied EA.hy926 (EA) cells, a human endothelial cell line that expresses MR. We incubated EA cells with ALDO (10-8 M), an MR agonist, for 24 hr and observed a rise in PDI mRNA levels by qRT-PCR (P<0.01, n=5), an event that was blocked by pre-incubation of EA cells with 1 μM canrenoic acid (CA), an MR antagonist (P<0.05, n=5). We then measured PDI activity in the supernatant of ALDO-stimulated EA cells using a Di-E-GSSH fluorescent marker and observed a rise in PDI activity following ALDO (10-8 M) when compared to vehicle treatment (P<0.05; n=5). To test the in vivo effects of MR activation, we studied Berkeley Sickle Transgenic (BERK) mice that were randomized to receive either normal rodent chow or chow containing eplerenone (156 mg/kg per day), an MR antagonist (MRA), for 14 days. We observed significantly lower plasma PDI activity in mice treated with MRA than those on regular chow (63.7 ± 8.7 control diet to 47.9 ± 2.4 eplerenone, Relative Fluorescence Units (RFU); P<0.005, n=6 and 9, respectively). Treatment with MRA was associated with reduced plasma ET-1 and myeloperoxidase (MPO) levels in BERK mice. We also studied RBC Gardos channel activity in these mice and observed a significant reduction in clotrimazole-sensitive K+ efflux following MR blockade (2.49±0.5 control and 1.37±0.3 mmol/1013 cells x hr; P<0.04 n= 5 and 7 respectively). Consistent with these results, MR blockade was associated with increases in both erythrocyte MCV (41.3±2.5 vs 47.4±1.1 fL, P<0.03, n=7) and reticulocyte MCV (53.6.3±2.8 vs 60.1±0.6 fL, P<0.02, n=7). We also studied gene expression by qRT-PCR in heart tissue from these mice and observed that MR blockade reduced mRNA expression of: ET-1 (0.654 ± 0.233, P<0.05, n=5 and n=7); PDI (0.546 ± 0.063, P<0.01, n=5 and n=7); and Tumor Necrosis Factor Receptor Superfamily Member 1A mRNA (0.464 ± 0.061, P<0.01, n=5 and n=7). Thus, our results suggest a novel role for RAAS and, in particular, MR activation in SCD. Disclosures No relevant conflicts of interest to declare.

scholarly journals Characterization of a Foldase, Protein Disulfide Isomerase A, in the Protein Secretory Pathway ofAspergillus niger

2000 ◽  
Vol 66 (2) ◽  
pp. 775-782 ◽  
Author(s):  
Celina Ngiam ◽  
David J. Jeenes ◽  
Peter J. Punt ◽  
Cees A. M. J. J. Van Den Hondel ◽  
David B. Archer
Keyword(s):  
Protein Disulfide Isomerase ◽  
Secretory Pathway ◽  
Functional Characterization ◽  
Killer Toxin ◽  
Rnase A ◽  
Secretory Proteins ◽  
Mrna Levels ◽  
Western Blots ◽  
Disulfide Isomerase ◽  
Protein Disulfide

ABSTRACT Protein disulfide isomerase (PDI) is important in assisting the folding and maturation of secretory proteins in eukaryotes. A gene,pdiA, encoding PDIA was previously isolated fromAspergillus niger, and we report its functional characterization here. Functional analysis of PDIA showed that it catalyzes the refolding of denatured and reduced RNase A.pdiA also complemented PDI function in aSaccharomyces cerevisiae Δpdi1 mutant in a yeast-based killer toxin assay. Levels of pdiA mRNA and PDIA protein were raised by the accumulation of unfolded proteins in the endoplasmic reticulum. This response of pdiA mRNA levels was slower and lower in magnitude than that of A. niger bipA, suggesting that the induction of pdiA is not part of the primary stress response. An increased level of pdiA transcripts was also observed in two A. niger strains overproducing a heterologous protein, hen egg white lysozyme (HEWL). Although overexpression of PDI has been successful in increasing yields of some heterologous proteins in S. cerevisiae, overexpression of PDIA did not increase secreted yields of HEWL in A. niger, suggesting that PDIA itself is not limiting for secretion of this protein. Downregulation of pdiA by antisense mRNA reduced the levels of microsomal PDIA activity by up to 50%, lowered the level of PDIA as judged by Western blots, and lowered the secreted levels of glucoamylase by 60 to 70%.

scholarly journals S-Glutathionylation of Protein Disulfide Isomerase Regulates Estrogen ReceptorαStability and Function

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ying Xiong ◽  
Yefim Manevich ◽  
Kenneth D. Tew ◽  
Danyelle M. Townsend
Keyword(s):  
Protein Disulfide Isomerase ◽  
Estrogen Receptor Alpha ◽  
Redox Regulation ◽  
Gene Products ◽  
Disulfide Isomerase ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
And Function ◽  
Protein Response ◽  
Protein Disulfide

S-Glutathionylation of cysteine residues within target proteins is a posttranslational modification that alters structure and function. We have shown that S-glutathionylation of protein disulfide isomerase (PDI) disrupts protein folding and leads to the activation of the unfolded protein response (UPR). PDI is a molecular chaperone for estrogen receptor alpha(ERα). Our present data show in breast cancer cells that S-glutathionylation of PDI interferes with its chaperone activity and abolishes its capacity to form a complex withERα. Such drug treatment also reverses estradiol-induced upregulation of c-Myc, cyclinD1, andP21Cip, gene products involved in cell proliferation. Expression of an S-glutathionylation refractory PDI mutant diminishes the toxic effects of PABA/NO. Thus, redox regulation of PDI causes its S-glutathionylation, thereby mediating cell death through activation of the UPR and abrogation ofERαstability and signaling.

scholarly journals Protein disulfide-isomerase interacts with soluble guanylyl cyclase via a redox-based mechanism and modulates its activity

2013 ◽  
Vol 452 (1) ◽  
pp. 161-169 ◽  
Author(s):  
Erin J. Heckler ◽  
Pierre-Antoine Crassous ◽  
Padmamalini Baskaran ◽  
Annie Beuve
Keyword(s):  
Guanylyl Cyclase ◽  
Protein Disulfide Isomerase ◽  
Cellular Localization ◽  
Redox Regulation ◽  
Soluble Guanylyl Cyclase ◽  
Proximity Ligation Assay ◽  
Western Blots ◽  
Disulfide Isomerase ◽  
Protein Disulfide

NO binds to the receptor sGC (soluble guanylyl cyclase), stimulating cGMP production. The NO–sGC–cGMP pathway is a key component in the cardiovascular system. Discrepancies in sGC activation and deactivation in vitro compared with in vivo have led to a search for endogenous factors that regulate sGC or assist in cellular localization. In our previous work, which identified Hsp (heat-shock protein) 70 as a modulator of sGC, we determined that PDI (protein disulfide-isomerase) bound to an sGC-affinity matrix. In the present study, we establish and characterize this interaction. Incubation of purified PDI with semi-purified sGC, both reduced and oxidized, resulted in different migration patterns on non-reducing Western blots indicating a redox component to the interaction. In sGC-infected COS-7 cells, transfected FLAG-tagged PDI and PDI CXXS (redox active site ‘trap mutant’) pulled down sGC. This PDI–sGC complex was resolved by reductant, confirming a redox interaction. PDI inhibited NO-stimulated sGC activity in COS-7 lysates, however, a PDI redox-inactive mutant PDI SXXS did not. Together, these data unveil a novel mechanism of sGC redox modulation via thiol-disulfide exchange. Finally, in SMCs (smooth muscle cells), endogenous PDI and sGC co-localize by in situ proximity ligation assay, which suggests biological relevance. PDI-dependent redox regulation of sGC NO sensitivity may provide a secondary control over vascular homoeostasis.

Aldosterone Stimulates Neutrophils Leading To Increased β-Glucuronidase, Protein Disulfide Isomerase and Myeloperoxidase Secretion

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2271-2271
Author(s):  
Arelys Ramos-Rivera ◽  
Alicia Rivera ◽  
Enrique D. Machado-Fiallo ◽  
Josue A. Benabe-Carlo ◽  
Gregory N. Prado ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Respiratory Burst ◽  
Protein Disulfide Isomerase ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Cell Disease ◽  
Rt Pcr ◽  
Disulfide Isomerase ◽  
Protein Disulfide

Abstract Aldosterone (ALDO) has been shown to play an important role in inflammatory responses in addition to its well described effects on sodium homeostasis via activation of the mineralocorticoid receptor (MR). However, its effects on polymorphonuclear leukocytes (PMNC) are not well described. We isolated untouched circulating human PMNC by immunomagnetic isolation following density gradient sedimentation with PolymorphPrep from otherwise healthy subjects. Flow cytometric analyses showed greater than 97% of PMNC were positive for the myeloid-neutrophil markers, CD45, CD16 and CD66b. We show that PMNC express MR by western blot and RT-PCR analyses. We incubated PMNC with ALDO (10–9–10–7M) for 30 min and observed a dose-dependent rise in β–glucuronidase release with an EC50 of 6.11 nM (P<0.001, n=3), an event that was blocked by pre-incubation of cells with 1μM canrenoic acid (CA), an MR antagonist (P<0.04, n=3). In addition, our results show that incubation of human PMNC with 10-8M ALDO likewise led to increases in myeloperoxidase ([MPO], P<0.05, n=3) and protein disulfide isomerase ([PDI], P<0.01, n=4), a multifunctional enzyme of the thioredoxin superfamily that mediates redox modifications, regulates KCNN4 channel and erythrocyte volume and is up-regulated under hypoxic conditions (Prado, 2013 FASEB J). We then studied the effects of ALDO on HL-60, a human promyelocytic cell line, induced to differentiate into neutrophil-like cells by incubation for 5 days with 1.3% DMSO. Our results likewise show an increase in MPO responses upon 10–8M ALDO stimulation as compared to vehicle (AUC: 1090±147 to 505±48, P<0.02, n=3). We have recently reported that aldosterone stimulates increases of striatin, a scaffolding protein that interacts with caveolin-1, and co-precipitates with striatin and as such may facilitate cross talk of signaling complexes. As there are no pharmacological inhibitors of striatin we used a molecular approach to reduce striatin levels. In differentiated HL-60 cells, siRNA against striatin led to reduced MPO responses (AUC: 590±14 to 528±13, P<0.05, n=3) that were associated with significantly reduced striatin mRNA levels but not when cells were transfected with scrambled siRNA as determined by quantitative RT-PCR with ABI TaqMan detection probes and β-microglobulin used as an endogenous control (P<0.01, n=3). These results suggest that striatin plays an important role in ALDO-stimulated degranulation responses. Of importance we also observed that incubation with ALDO (10–9–10–7M) in differentiated HL60 cells led to increases in the oxidative-respiratory burst [superoxide production] in a dose- and time-dependent manner (P<0.01, n=4). Consistent with these results, we observed that ALDO likewise led to significant increases in the oxidative-respiratory burst in human PMNC (P<0.01, n=3). As there is evidence that activated neutrophils, MPO and PDI are elevated in Sickle Cell Disease, we studied the in vivo effects of MR blockade in BERK sickle transgenic mice, a model of increased oxidative stress. Sickle mice were randomized to receive either normal rodent chow or chow containing eplerenone (156 mg/kg per day), an MR receptor antagonist, and tap water ad libitum for 14 days at which time the mice were sacrificed and blood collected. We observed that mice on eplerenone had significantly lower plasma PDI activity than mice on regular chow (63.7 ± 8.7 control diet to 47.9 ± 2.4 eplerenone, Relative Fluorescence Units [RFU]; P<0.005, n=6 and 9) and lower MPO levels (AUC: 214±11 to 73±20, P<0.03, n=3); events that were associated with increases in both erythrocyte MCV (41.3±2.5 vs 47.4±1.1 fL, P<0.03, n=7) and reticulocyte MCV (53.6.3±2.8 vs 60.1±0.6 fL, P<0.02, n=7). Thus, our results suggest that MR activation by ALDO is a novel mechanism for neutrophil stimulation and as such represents a novel therapeutic target aimed at ameliorating the vascular complications of Sickle Cell Disease. Supported by NIH R01HL090632 (AR) and R01HL096518 (JRR). Disclosures: No relevant conflicts of interest to declare.

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