Abstract P014: Oxidative Stress Mediated Regulation of Antioxidants in Cardiac Progenitor Cells

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Gokulakrishnan Iyer ◽  
Michael E Davis
Keyword(s):  
Oxidative Stress ◽  
Xanthine Oxidase ◽  
Progenitor Cells ◽  
Cardiac Progenitor Cells ◽  
Dependent Manner ◽  
Akt Inhibitor ◽  
Differentiation Potential ◽  
Lineage Differentiation ◽  
Phosphorylated Akt

Cardiac diseases are the leading causes of death throughout the world and transplantation of endogenous myocardial progenitor population with robust cardiovascular lineage differentiation potential is a promising therapeutic strategy. Therefore, in vitro expansion and transplantation of cardiac progenitor cells (CPCs) is currently in early clinical testing as a potential treatment for severe cardiac dysfunction. However, poor survival and engraftment of cells is one of the major limitations of cell transplantation therapy. Oxidative stress is increased in the ischemic myocardium and indirect inferences suggest the vulnerability of CPCs to oxidative stress. In this study, we show that in vitro, resident c-kit positive CPCs isolated from rat myocardium are significantly (p<0.05) resistant to superoxide-induced apoptosis compared to cardiomyocytes as analyzed by the number of sub-G1 population following xanthine/xanthine oxidase treatment. Interestingly, CPCs have two to four fold higher basal SOD1 and SOD2 activities (p<0.01) compared to cardiomyocytes and endothelial cells. Superoxide treatment increased expression of SOD1 (p<0.01), SOD2 (p<0.01), and glutathione peroxidase (p<0.05) mRNAs within 6 h of treatment compared to control cells. Recent studies suggest the involvement of AKT in controlling cell death, survival and also expression of SOD enzymes. Therefore, we investigated the involvement of AKT in CPCs subjected to oxidative stress. Western blot analysis revealed that the amount of phosphorylated AKT increased significantly within 10 minutes of xanthine/xanthine oxidase treatment. In addition, treatment with LY294002 - a PI3 kinase/AKT inhibitor, increased apoptosis in CPCs treated with superoxide. Our studies demonstrate a novel finding in which resident progenitor cells are protected from oxidative injury by containing higher basal levels of antioxidants as compared to myocytes. Moreover, under oxidant challenge antioxidant levels are regulated, possibly in an AKT-dependent manner. Further elucidation of this pathway may lead to novel therapeutic opportunities.

Abstract 217: Long Non-coding RNA Myocardial Infarction-associated Transcript (MIAT) Protects Cardiac Progenitor Cells From Oxidative Stress-induced Cell Death

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Liu Yang ◽  
Yang Yu ◽  
Baron Arnone ◽  
Chan Boriboun ◽  
Jiawei Shi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Cell Death ◽  
Progenitor Cells ◽  
Cardiac Cells ◽  
Border Zone ◽  
Mouse Heart ◽  
Cardiac Progenitor Cells

Background: Long non-coding RNAs (lncRNAs) are an emerging class of RNAs with no or limited protein-coding capacity; a few of which have recently been shown to regulate critical biological processes. Myocardial infarction-associated transcript (MIAT) is a conserved mammalian lncRNA, and single nucleotide polymorphisms (SNPs) in 6 loci of this gene have been identified to be strongly associated with the incidence and severity of human myocardial infarction (MI). However, whether and how MIAT impacts on the pathogenesis of MI is unknown. Methods & Results: Quantitative RT-PCR analyses revealed that MIAT is expressed in neonatal mouse heart and to a lesser extent in adult heart. After surgical induction of MI in adult mice, MIAT starts to increase in 2 hours, peaks at 6 hours in atria and 12 hours in ventricles, and decreases to baseline at 24 hours. Fluorescent in situ hybridization (FISH) revealed a slight increase in the number of MIAT-expressing cells in the infarct border zone at 12 hours post-MI. Moreover, qRT-PCR analyses of isolated cardiac cells revealed that MIAT is predominantly expressed in cardiosphere-derived cardiac progenitor cells (CPCs). Treatment of CPCs with H 2 O 2 led to a marked upregulation of MIAT, while knockdown (KD) of MIAT resulted in a significantly impaired cell survival in vitro with H 2 O 2 treatment and in vivo after administered in the ischemic/reperfused heart. Notably, bioinformatics prediction and RNA immunoprecipitation identified FUS (fused in sarcoma) as a novel MIAT-interacting protein. FUS-KD CPCs displayed reduced cell viability and increased apoptosis under oxidative stress. Furthermore, MIAT overexpression enhanced survival of WT CPCs but not FUS-KD CPCs, suggesting that the protective role of MIAT is mediated by FUS. Conclusions: MIAT interacts with FUS to protect CPCs from oxidative stress-induced cell death.

scholarly journals Yangxin granules alleviate doxorubicin-induced cardiotoxicity by suppressing oxidative stress and apoptosis mediated by AKT/GSK3β/β-catenin signaling

2020 ◽  
Vol 48 (8) ◽  
pp. 030006052094516
Author(s):  
Dezhi Ren ◽  
Fang Li ◽  
Qingwen Cao ◽  
An Gao ◽  
Yingna Ai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Molecular Mechanisms ◽  
Inflammatory Factor ◽  
H9c2 Cells ◽  
Akt Inhibitor ◽  
Phosphorylated Akt ◽  
H9c2 Cardiomyocytes ◽  
Clinical Benefits

Background Yangxin granules (YXC), a Chinese herbal medicine, have been confirmed to have clinical benefits in the treatment of heart failure. This study examined the effects and molecular mechanisms of YXC in the treatment of doxorubicin-induced cardiotoxicity in vitro. Methods H9c2 cardiomyocytes were pretreated with YXC (5, 10, or 20 mg/mL) or the AKT inhibitor MK-2206 (50 nM) before doxorubicin treatment (1 µM). Cell apoptosis, viability, inflammatory factor expression (TNF-α, IL-1β, and IL-6), and oxidative stress mediator levels including superoxide dismutase, reactive oxygen species, and malondialdehyde were detected. Results YXC increased the viability of H9c2 cells. In addition, doxorubicin inhibited AKT/GSK3β/β-catenin signaling, whereas YXC increased the expression of phosphorylated AKT and GSK3β, and β-catenin in doxorubicin-treated H9c2 cells. Moreover, T-cell factor/lymphoid enhancer factor signaling downstream of β-catenin was also activated by YXC. YXC pretreatment also inhibited doxorubicin-induced inflammation, oxidative stress, and apoptosis. However, MK-2206 reversed the effects of YXC in doxorubicin-treated H9c2 cells. Conclusions YXC alleviates doxorubicin-induced inflammation, oxidative stress, and apoptosis in H9c2 cells. These effects might be mediated by the AKT/GSK3β/β-catenin signaling pathway. YXC might have preventive effects against doxorubicin-induced heart failure.

scholarly journals Protective mechanism of artemisinin on rat bone marrow-derived mesenchymal stem cells against apoptosis induced by hydrogen peroxide via activation of c-Raf-Erk1/2-p90rsk-CREB pathway

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiankang Fang ◽  
Xia Zhao ◽  
Shuai Li ◽  
Xingan Xing ◽  
Haitao Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bone Marrow ◽  
Protective Effect ◽  
Caspase 3 ◽  
B Cell Lymphoma ◽  
Protective Mechanism ◽  
Dependent Manner ◽  
Differentiation Potential ◽  
Induced Apoptosis

Abstract Background Bone marrow-derived mesenchymal stem cell (BMSC) transplantation is one of the new therapeutic strategies for treating ischemic brain and heart tissues. However, the poor survival rate of transplanted BMSCs in ischemic tissue, due to high levels of reactive oxygen species (ROS), limits the therapeutic efficacy of this approach. Considering that BMSC survival may greatly enhance the effectiveness of transplantation therapy, development of effective therapeutics capable of mitigating oxidative stress-induced BMSC apoptosis is an important unmet clinical need. Methods BMSCs were isolated from the 4-week-old male Sprague Dawley rats by whole bone marrow adherent culturing, and the characteristics were verified by morphology, immunophenotype, adipogenic, and osteogenic differentiation potential. BMSCs were pretreated with artemisinin, and H2O2 was used to induce apoptosis. Cell viability was detected by MTT, FACS, LDH, and Hoechst 33342 staining assays. Mitochondrial membrane potential (ΔΨm) was measured by JC-1 assay. The apoptosis was analyzed by Annexin V-FITC/PI and Caspase 3 Activity Assay kits. ROS level was evaluated by using CellROX® Deep Red Reagent. SOD, CAT, and GPx enzymatic activities were assessed separately using Cu/Zn-SOD and Mn-SOD Assay Kit with WST-8, Catalase Assay Kit, and Total Glutathione Peroxidase Assay Kit. The effects of artemisinin on protein expression of BMSCs including p-Erk1/2, t-Erk1/2, p-c-Raf, p-p90rsk, p-CREB, BCL-2, Bax, p-Akt, t-Akt, β-actin, and GAPDH were measured by western blotting. Results We characterized for the first time the protective effect of artemisinin, an anti-malaria drug, using oxidative stress-induced apoptosis in vitro, in rat BMSC cultures. We found that artemisinin, at clinically relevant concentrations, improved BMSC survival by reduction of ROS production, increase of antioxidant enzyme activities including SOD, CAT, and GPx, in correlation with decreased Caspase 3 activation, lactate dehydrogenase (LDH) release and apoptosis, all induced by H2O2. Artemisinin significantly increased extracellular-signal-regulated kinase 1/2 (Erk1/2) phosphorylation, in a concentration- and time-dependent manner. PD98059, the specific inhibitor of the Erk1/2 pathway, blocked Erk1/2 phosphorylation and artemisinin protection. Similarly, decreased expression of Erk1/2 by siRNA attenuated the protective effect of artemisinin. Additionally, when the upstream activator KRAS was knocked down by siRNA, the protective effect of artemisinin was also blocked. These data strongly indicated the involvement of the Erk1/2 pathway. Consistent with this hypothesis, artemisinin increased the phosphorylation of Erk1/2 upstream kinases proto-oncogene c-RAF serine/threonine-protein kinase (c-Raf) and of Erk1/2 downstream targets p90 ribosomal s6 kinase (p90rsk) and cAMP response element binding protein (CREB). In addition, we found that the expression of anti-apoptotic protein B cell lymphoma 2 protein (BcL-2) was also upregulated by artemisinin. Conclusion These studies demonstrate the proof of concept of artemisinin therapeutic potential to improve survival in vitro of BMSCs exposed to ROS-induced apoptosis and suggest that artemisinin-mediated protection occurs via the activation of c-Raf-Erk1/2-p90rsk-CREB signaling pathway.

Abstract 1115: Impaired Angiogenic Potential of Cardiac Progenitor Cells in Mice with a Cardiomyocyte-Restricted Knock Out of STAT3

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Philipp Fischer ◽  
Ewa Missol-Kolka ◽  
Nils-Holger Zschemisch ◽  
Christian Templin ◽  
Helmut Drexler ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Adipocyte Differentiation ◽  
Prostaglandin E ◽  
Mouse Heart ◽  
Cardiac Progenitor Cells ◽  
Rt Pcr ◽  
Differentiation Potential ◽  
Intramyocardial Injection ◽  
Knock Out

Mice with a cardiomyocyte-restricted knock out of STAT3 (KO: alpha-MHC-Cre tg/+; STAT3 flox/flox ) show a continuous decrease of the cardiac capillary density and develop heart failure beyond the age of 9 months. We sought to determine the paracrine influence of cardiomyocyte STAT3 on the endothelial differentiation potential of cardiac progenitor cells (CPC) of the adult mouse heart. Sca-1 + CPC were isolated from male mice hearts by MACS separation. STAT3 was entirely deleted in cardiomyocytes of KO mice, while CPC from KO showed normal expression of STAT3 (confirmed by PCR and Western blot). No difference in the total number of CPC per heart was observed between wildtype (WT: STAT3 flox/flox ) and KO mice. FACS analysis revealed a reduced number of endothelial progenitor cells (as defined by coexpression of Sca-1, CD31 and CD38, −25%, P<0.05) among CPC from KO compared to CPC from WT. The differentiation potential of CPC from WT and KO was analyzed during in vitro culture on fibronectin-coated plates. After 4 weeks of culture RT-PCR for CD31 and immunohistochemistry (IHC) for endothelial cell (EC) marker tie2 and isolectin B4 was performed. CPC from WT showed markedly more efficient EC differentiation and tube formation compared to CPC from KO (p<0.01). In contrast, adipocyte differentiation was enhanced in CPC from KO (p<0.05, oil red staining and RT-PCR). Proliferation capacity of CPC from KO was reduced by 33% (p<0.01) as compared to CPC from WT. Microarray results of freshly isolated CPC were consistent with the differences in EC and adipocyte differentiation (i.e. prostaglandin E receptor 3 up 2.3-fold in CPC from WT, Lipocalin-2 up 2.7-fold in CPC from KO). We did not observe cardiomyocyte differentiation (IHC for alpha-sarcomeric actinin; RT-PCR for Nkx 2.5, alpha-MHC, or alpha-skeletal actin) of CPC from both genotypes, neither in vitro by addition of oxytocin, 5-AZA, DMSO, nor following intramyocardial injection of CPC in vivo. Conclusion: STAT3-dependent paracrine mediators released from cardiomyocytes are determinants of differentiation and vasculogenic properties of new EC derived from cardiac progenitor cells. The identification of these factors may offer new approaches to enforce the endogenous vasculogenic repair potential of the adult heart.

scholarly journals Pre-Treatment with Melatonin Enhances Therapeutic Efficacy of Cardiac Progenitor Cells for Myocardial Infarction

2018 ◽  
Vol 47 (3) ◽  
pp. 1287-1298 ◽  
Author(s):  
Wenya Ma ◽  
Fang He ◽  
Fengzhi Ding ◽  
Lai Zhang ◽  
Qi Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Progenitor Cells ◽  
Therapeutic Efficacy ◽  
Biological Activities ◽  
Cardiac Progenitor Cells ◽  
Pre Treatment ◽  
Induced Apoptosis

Background/Aims: Melatonin possesses many biological activities such as antioxidant and anti-aging. Cardiac progenitor cells (CPCs) have emerged as a promising therapeutic strategy for myocardial infarction (MI). However, the low survival of transplanted CPCs in infarcted myocardium limits the successful use in treating MI. In the present study, we aimed to investigate if melatonin protects against oxidative stress-induced CPCs damage and enhances its therapeutic efficacy for MI. Methods: TUNEL assay and EdU assay were used to detect the effects of melatonin and miR-98 on H2O2-induced apoptosis and proliferation. MI model was used to evaluate the potential cardioprotective effects of melatonin and miR-98. Results: Melatonin attenuated H2O2-induced the proliferation reduction and apoptosis of c-kit+ CPCs in vitro, and CPCs which pretreated with melatonin significantly improved the functions of post-infarct hearts compared with CPCs alone in vivo. Melatonin was capable to inhibit the increase of miR-98 level by H2O2 in CPCs. The proliferation reduction and apoptosis of CPCs induced by H2O2 was aggravated by miR-98. In vivo, transplantation of CPCs with miR-98 silencing caused the more significant improvement of cardiac functions in MI than CPCs. MiR-98 targets at the signal transducer and activator of the transcription 3 (STAT3), and thus aggravated H2O2-induced the reduction of Bcl-2 protein. Conclusions: Pre-treatment with melatonin protects c-kit+ CPCs against oxidative stress-induced damage via downregulation of miR-98 and thereby increasing STAT3, representing a potentially new strategy to improve CPC-based therapy for MI.

scholarly journals Novel Identified Circular Transcript of RCAN2, circ-RCAN2, Shows Deviated Expression Pattern in Pig Reperfused Infarcted Myocardium and Hypoxic Porcine Cardiac Progenitor Cells In Vitro

2021 ◽  
Vol 22 (3) ◽  
pp. 1390
Author(s):  
Julia Mester-Tonczar ◽  
Patrick Einzinger ◽  
Johannes Winkler ◽  
Nina Kastner ◽  
Andreas Spannbauer ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Progenitor Cells ◽  
Regulatory Networks ◽  
Circular Rnas ◽  
Cardiac Progenitor Cells ◽  
Tissue Samples ◽  
Healthy Myocardium ◽  
Acute Mi

Circular RNAs (circRNAs) are crucial in gene regulatory networks and disease development, yet circRNA expression in myocardial infarction (MI) is poorly understood. Here, we harvested myocardium samples from domestic pigs 3 days after closed-chest reperfused MI or sham surgery. Cardiac circRNAs were identified by RNA-sequencing of rRNA-depleted RNA from infarcted and healthy myocardium tissue samples. Bioinformatics analysis was performed using the CIRIfull and KNIFE algorithms, and circRNAs identified with both algorithms were subjected to differential expression (DE) analysis and validation by qPCR. Circ-RCAN2 and circ-C12orf29 expressions were significantly downregulated in infarcted tissue compared to healthy pig heart. Sanger sequencing was performed to identify the backsplice junctions of circular transcripts. Finally, we compared the expressions of circ-C12orf29 and circ-RCAN2 between porcine cardiac progenitor cells (pCPCs) that were incubated in a hypoxia chamber for different time periods versus normoxic pCPCs. Circ-C12orf29 did not show significant DE in vitro, whereas circ-RCAN2 exhibited significant ischemia-time-dependent upregulation in hypoxic pCPCs. Overall, our results revealed novel cardiac circRNAs with DE patterns in pCPCs, and in infarcted and healthy myocardium. Circ-RCAN2 exhibited differential regulation by myocardial infarction in vivo and by hypoxia in vitro. These results will improve our understanding of circRNA regulation during acute MI.

scholarly journals Oxidative stress increases megalin expression in the renal proximal tubules during the normoalbuminuric stage of diabetes mellitus

2018 ◽  
Vol 314 (3) ◽  
pp. F462-F470 ◽  
Author(s):  
Yoshifumi Kurosaki ◽  
Akemi Imoto ◽  
Fumitaka Kawakami ◽  
Masanori Yokoba ◽  
Tsuneo Takenaka ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Hydrogen Peroxide ◽  
High Glucose ◽  
Renal Cortex ◽  
Dependent Manner ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphorylated Akt ◽  
Stress Dependent ◽  
Phosphatidylinositol 3

Megalin, an endocytic receptor expressed in proximal tubule cells, plays a critical role in renal tubular protein reabsorption and is associated with the albuminuria observed in diabetic nephropathy. We have previously reported increased oxidant production in the renal cortex during the normoalbuminuric stage of diabetes mellitus (DM); however, the relationship between oxidative stress and renal megalin expression during the normoalbuminuric stage of DM remains unclear. In the present study, we evaluated whether oxidative stress affects megalin expression in the normoalbuminuric stage of DM in a streptozotocin-induced diabetic rat model and in immortalized human proximal tubular cells (HK-2). We demonstrated that increased expression of renal megalin accompanies oxidative stress during the early stage of DM, before albuminuria development. Telmisartan treatment prevented the diabetes-induced elevation in megalin level, possibly through an oxidative stress-dependent mechanism. In HK-2 cells, hydrogen peroxide significantly increased megalin levels in a dose- and time-dependent manner; however, the elevation in megalin expression was decreased following prolonged exposure to severe oxidative stress induced by 0.4 mmol/l hydrogen peroxide. High-glucose treatment also significantly increased megalin expression in HK-2 cells. Concurrent administration of the antioxidant N-acetyl-cysteine blocked the effects of high glucose on megalin expression. Furthermore, the hydrogen peroxide-induced increase in megalin expression was blocked by treatment with phosphatidylinositol 3-kinase and Akt inhibitors. Increase of phosphorylated Akt expression was also seen in the renal cortex of diabetic rats. Taken together, our results indicate that mild oxidative stress increases renal megalin expression through the phosphatidylinositol 3-kinase-Akt pathway in the normoalbuminuric stage of DM.

scholarly journals Ligand-dependent repression of the erythroid transcription factor GATA-1 by the estrogen receptor.

1995 ◽  
Vol 15 (6) ◽  
pp. 3147-3153 ◽  
Author(s):  
G A Blobel ◽  
C A Sieff ◽  
S H Orkin
Keyword(s):  
Bone Marrow ◽  
Estrogen Receptor ◽  
Transcription Factor ◽  
Progenitor Cells ◽  
Erythroid Cell ◽  
High Dose ◽  
Dependent Manner ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells

High-dose estrogen administration induces anemia in mammals. In chickens, estrogens stimulate outgrowth of bone marrow-derived erythroid progenitor cells and delay their maturation. This delay is associated with down-regulation of many erythroid cell-specific genes, including alpha- and beta-globin, band 3, band 4.1, and the erythroid cell-specific histone H5. We show here that estrogens also reduce the number of erythroid progenitor cells in primary human bone marrow cultures. To address potential mechanisms by which estrogens suppress erythropoiesis, we have examined their effects on GATA-1, an erythroid transcription factor that participates in the regulation of the majority of erythroid cell-specific genes and is necessary for full maturation of erythrocytes. We demonstrate that the transcriptional activity of GATA-1 is strongly repressed by the estrogen receptor (ER) in a ligand-dependent manner and that this repression is reversible in the presence of 4-hydroxytamoxifen. ER-mediated repression of GATA-1 activity occurs on an artificial promoter containing a single GATA-binding site, as well as in the context of an intact promoter which is normally regulated by GATA-1. GATA-1 and ER bind to each other in vitro in the absence of DNA. In coimmunoprecipitation experiments using transfected COS cells, GATA-1 and ER associate in a ligand-dependent manner. Mapping experiments indicate that GATA-1 and the ER form at least two contacts, which involve the finger region and the N-terminal activation domain of GATA-1. We speculate that estrogens exert effects on erythropoiesis by modulating GATA-1 activity through protein-protein interaction with the ER. Interference with GATA-binding proteins may be one mechanism by which steroid hormones modulate cellular differentiation.

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