Publications by authors named "Narasimham L Parinandi"

73 Publications

NOX4 Mediates -Induced Nuclear Reactive Oxygen Species Generation and Chromatin Remodeling in Lung Epithelium.

Antioxidants (Basel) 2021 Mar 17;10(3). Epub 2021 Mar 17.

Departments of Pharmacology & Regenerative Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.

() infection increases reactive oxygen species (ROS), and earlier, we have shown a role for NADPH oxidase-derived ROS in -mediated lung inflammation and injury. Here, we show a role for the lung epithelial cell (LEpC) NOX4 in -mediated chromatin remodeling and lung inflammation. Intratracheal administration of to Nox4 mice for 24 h caused lung inflammatory injury; however, epithelial cell-deleted Nox4 mice exhibited reduced lung inflammatory injury, oxidative stress, secretion of pro-inflammatory cytokines, and decreased histone acetylation. In LEpCs, NOX4 was localized both in the cytoplasmic and nuclear fractions, and stimulation increased the nuclear NOX4 expression and ROS production. Downregulation or inhibition of NOX4 and PKC δ attenuated the -induced nuclear ROS. -induced histone acetylation was attenuated by -specific siRNA, unlike . stimulation increased HDAC1/2 oxidation and reduced HDAC1/2 activity. The -induced oxidation of HDAC2 was attenuated by -acetyl-L-cysteine and siRNA specific for , , and . stimulated RAC1 activation in the nucleus and enhanced the association between HDAC2 and RAC1, p-PKC δ, and NOX4 in LEpCs. Our results revealed a critical role for the alveolar epithelial NOX4 in mediating -induced lung inflammatory injury via nuclear ROS generation, HDAC1/2 oxidation, and chromatin remodeling.
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http://dx.doi.org/10.3390/antiox10030477DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8002602PMC
March 2021

Defective immunometabolism pathways in cystic fibrosis macrophages.

J Cyst Fibros 2020 Nov 15. Epub 2020 Nov 15.

Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210, USA. Electronic address:

Background: Mitochondria play a key role in immune defense pathways, particularly for macrophages. We and others have previously demonstrated that cystic fibrosis (CF) macrophages exhibit weak autophagy activity and exacerbated inflammatory responses. Previous studies have revealed that mitochondria are defective in CF epithelial cells, but to date, the connection between defective mitochondrial function and CF macrophage immune dysregulation has not been fully elucidated. Here, we present a characterization of mitochondrial dysfunction in CF macrophages.

Methods: Mitochondrial function in wild-type (WT) and CF F508del/F508del murine macrophages was measured using the Seahorse Extracellular Flux analyzer. Mitochondrial morphology was investigated using transmission electron and confocal microscopy. Mitochondrial membrane potential (MMP) as well as mitochondrial reactive oxygen species (mROS) were measured using TMRM and MitoSOX Red fluorescent dyes, respectively. All assays were performed at baseline and following infection by Burkholderia cenocepacia, a multi-drug resistant bacterium that causes detrimental infections in CF patients.

Results: We have identified impaired oxygen consumption in CF macrophages without and with B. cenocepacia infection. We also observed increased mitochondrial fragmentation in CF macrophages following infection. Lastly, we observed increased MMP and impaired mROS production in CF macrophages following infection with B. cenocepacia.

Conclusions: The mitochondrial defects identified are key components of the macrophage response to infection. Their presence suggests that mitochondrial dysfunction contributes to impaired bacterial killing in CF macrophages. Our current study will enhance our understanding of the pathobiology of CF and lead to the identification of novel mitochondrial therapeutic targets for CF.
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http://dx.doi.org/10.1016/j.jcf.2020.10.006DOI Listing
November 2020

The role of vascular endothelium and exosomes in human protozoan parasitic diseases.

Vessel Plus 2020 27;4. Epub 2020 Sep 27.

Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, The Ohio State University Medical Center, Columbus, OH 43201, USA.

The vascular endothelium is a vital component in maintaining the structure and function of blood vessels. The endothelial cells (ECs) mediate vital regulatory functions such as the proliferation of cells, permeability of various tissue membranes, and exchange of gases, thrombolysis, blood flow, and homeostasis. The vascular endothelium also regulates inflammation and immune cell trafficking, and ECs serve as a replicative niche for many bacterial, viral, and protozoan infectious diseases. Endothelial dysfunction can lead to vasodilation and pro-inflammation, which are the hallmarks of many severe diseases. Exosomes are nanoscale membrane-bound vesicles that emerge from cells and serve as important extracellular components, which facilitate communication between cells and maintain homeostasis during normal and pathophysiological states. Exosomes are also involved in gene transfer, inflammation and antigen presentation, and mediation of the immune response during pathogenic states. Protozoa are a diverse group of unicellular organisms that cause many infectious diseases in humans. In this regard, it is becoming increasingly evident that many protozoan parasites (such as , , , and ) utilize exosomes for the transfer of their virulence factors and effector molecules into the host cells, which manipulate the host gene expression, immune responses, and other biological activities to establish and modulate infection. In this review, we discuss the role of the vascular endothelium and exosomes in and their contribution to pathogenesis in malaria, African sleeping sickness, Chagas disease, and leishmaniasis and toxoplasmosis with an emphasis on their actions on the innate and adaptive immune mechanisms of resistance.
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http://dx.doi.org/10.20517/2574-1209.2020.27DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7575144PMC
September 2020

The expression of Mirc1/Mir17-92 cluster in sputum samples correlates with pulmonary exacerbations in cystic fibrosis patients.

J Cyst Fibros 2018 07 11;17(4):454-461. Epub 2017 Dec 11.

Department of Microbial Infection and Immunity, Columbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, Columbus, OH, USA; The Ohio State University College of Medicine, Columbus, OH, USA. Electronic address:

Introduction: Cystic fibrosis (CF) is a multi-organ disorder characterized by chronic sino-pulmonary infections and inflammation. Many patients with CF suffer from repeated pulmonary exacerbations that are predictors of worsened long-term morbidity and mortality. There are no reliable markers that associate with the onset or progression of an exacerbation or pulmonary deterioration. Previously, we found that the Mirc1/Mir17-92a cluster which is comprised of 6 microRNAs (Mirs) is highly expressed in CF mice and negatively regulates autophagy which in turn improves CF transmembrane conductance regulator (CFTR) function. Therefore, here we sought to examine the expression of individual Mirs within the Mirc1/Mir17-92 cluster in human cells and biological fluids and determine their role as biomarkers of pulmonary exacerbations and response to treatment.

Methods: Mirc1/Mir17-92 cluster expression was measured in human CF and non-CF plasma, blood-derived neutrophils, and sputum samples. Values were correlated with pulmonary function, exacerbations and use of CFTR modulators.

Results: Mirc1/Mir17-92 cluster expression was not significantly elevated in CF neutrophils nor plasma when compared to the non-CF cohort. Cluster expression in CF sputum was significantly higher than its expression in plasma. Elevated CF sputum Mirc1/Mir17-92 cluster expression positively correlated with pulmonary exacerbations and negatively correlated with lung function. Patients with CF undergoing treatment with the CFTR modulator Ivacaftor/Lumacaftor did not demonstrate significant change in the expression Mirc1/Mir17-92 cluster after six months of treatment.

Conclusions: Mirc1/Mir17-92 cluster expression is a promising biomarker of respiratory status in patients with CF including pulmonary exacerbation.
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http://dx.doi.org/10.1016/j.jcf.2017.11.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5995663PMC
July 2018

Pentalinonsterol, a Constituent of Pentalinon andrieuxii, Possesses Potent Immunomodulatory Activity and Primes T Cell Immune Responses.

J Nat Prod 2017 09 6;80(9):2515-2523. Epub 2017 Sep 6.

College of Public Health, §College of Pharmacy, and ∥Department of Microbiology, The Ohio State University , Columbus, Ohio 43210, United States.

The use of natural products as adjuvants has emerged as a promising approach for the development of effective vaccine formulations. Pentalinonsterol (PEN) is a recently isolated compound from the roots of Pentalinon andrieuxii and has been shown to possess antileishmanial activity against Leishmania spp. The objective of this study was to examine the immunomodulatory properties of PEN and evaluate its potential as an adjuvant. Macrophages and bone-marrow-derived dendritic cells (BMDCs) were stimulated with PEN and tested for gene expression, cytokine production, and their ability to activate T cells in vitro. PEN was also evaluated for its ability to generate antigen-specific Th1 and Th2 responses in vivo, following ovalbumin (OVA) immunization using PEN as an adjuvant. The results obtained demonstrate that PEN enhances the expression of NF-κB and AP1 transcription factors, promotes gene expression of Tnfα, Il6, Nos2, and Arg1, and upregulates MHCII, CD80, and CD86 in macrophages. PEN also enhanced IL-12 production in BMDCs and promoted BMDC-mediated production of IFN-γ by T cells. Further, mice immunized with OVA and PEN showed enhanced antigen-specific Th1 and Th2 cytokines in their splenocytes and lymph node cells, as well as increased levels of IgG1 and IgG2 in their sera. Taken together, this study demonstrates that PEN is a potent immunomodulatory compound and potentially can be used as an adjuvant for vaccine development against infectious diseases.
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http://dx.doi.org/10.1021/acs.jnatprod.7b00445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5731641PMC
September 2017

Green Synthesized Zinc Oxide (ZnO) Nanoparticles Induce Oxidative Stress and DNA Damage in Lathyrus sativus L. Root Bioassay System.

Antioxidants (Basel) 2017 May 18;6(2). Epub 2017 May 18.

Molecular Biology and Genomics Laboratory, Department of Botany, Berhampur University, Berhampur 760007, Odisha, India.

Zinc oxide nanoparticles (ZnONP-GS) were synthesised from the precursor zinc acetate (Zn(CH₃COO)₂) through the green route using the milky latex from milk weed ( L. R. Br) by alkaline precipitation. Formation of the ZnONP-GS was monitored by UV-visible spectroscopy followed by characterization and confirmation by energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Both the ZnONP-GS and the commercially available ZnONP-S (Sigma-Aldrich) and cationic Zn from Zn(CH₃COO)₂ were tested in a dose range of 0-100 mg·L for their potency (i) to induce oxidative stress as measured by the generation reactive oxygen species (ROS: O₂, H₂O₂ and OH), cell death, and lipid peroxidation; (ii) to modulate the activities of antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX); and (iii) to cause DNA damage as determined by Comet assay in L. root bioassay system. Antioxidants such as Tiron and dimethylthiourea significantly attenuated the ZnONP-induced oxidative and DNA damage, suggesting the involvement of ROS therein. Our study demonstrated that both ZnONP-GS and ZnONP-S induced oxidative stress and DNA damage to a similar extent but were significantly less potent than Zn alone.
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http://dx.doi.org/10.3390/antiox6020035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5488015PMC
May 2017

A Novel Sterol Isolated from a Plant Used by Mayan Traditional Healers Is Effective in Treatment of Visceral Leishmaniasis Caused by Leishmania donovani.

ACS Infect Dis 2015 Oct 21;1(10):497-506. Epub 2015 Sep 21.

Department of Pathology, The Wexner Medical Center, The Ohio State University , 320 West 10th Avenue, Columbus, Ohio 43210, United States.

Visceral leishmaniasis (VL), caused by the protozoan parasite Leishmania donovani, is a global health problem affecting millions of people worldwide. Treatment of VL largely depends on therapeutic drugs such as pentavalent antimonials, amphotericin B, and others, which have major drawbacks due to drug resistance, toxicity, and high cost. In this study, for the first time, we have successfully demonstrated the synthesis and antileishmanial activity of the novel sterol pentalinonsterol (PEN), which occurs naturally in the root of a Mexican medicinal plant, Pentalinon andrieuxii. In the experimental BALB/c mouse model of VL induced by infection with L. donovani, intravenous treatment with liposome-encapsulated PEN (2.5 mg/kg) led to a significant reduction in parasite burden in the liver and spleen. Furthermore, infected mice treated with liposomal PEN showed a strong host-protective TH1 immune response characterized by IFN-γ production and formation of matured hepatic granulomas. These results indicate that PEN could be developed as a novel drug against VL.
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http://dx.doi.org/10.1021/acsinfecdis.5b00081DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5730984PMC
October 2015

Polyvinyl polypyrrolidone attenuates genotoxicity of silver nanoparticles synthesized via green route, tested in Lathyrus sativus L. root bioassay.

Mutat Res Genet Toxicol Environ Mutagen 2016 Aug 8;806:11-23. Epub 2016 Jun 8.

Molecular Biology and Genomics Laboratory, Department of Botany, Berhampur University, Berhampur 760 007, India,. Electronic address:

The silver nanoparticles (AgNPs) were synthesized extracellularly from silver nitrate (AgNO3) using kernel extract from ripe mango Mengifera indica L. under four different reaction conditions of the synthesis media such as the (i) absence of the reducing agent, trisodium citrate (AgNPI), (ii) presence of the reducing agent (AgNPII), (iii) presence of the cleansing agent, polyvinyl polypyrrolidone, PVPP (AgNPIII), and (iv) presence of the capping agent, polyvinyl pyrrolidone, PVP (AgNPIV). The synthesis of the AgNPs was monitored by UV-vis spectrophotometry. The AgNPs were characterised by the energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and small-angle X-ray scattering. Functional groups on the AgNPs were established by the Fourier transform infrared spectroscopy. The AgNPs (AgNPI, AgNPII, AgNPIII and AgNPIV) were spherical in shape with the diameters and size distribution-widths of 14.0±5.4, 19.2±6.6, 18.8±6.6 and 44.6±13.2nm, respectively. Genotoxicity of the AgNPs at concentrations ranging from 1 to 100mgL(-1) was determined by the Lathyrus sativus L. root bioassay and several endpoint assays including the generation of reactive oxygen species and cell death, lipid peroxidation, mitotic index, chromosome aberrations (CA), micronucleus formation (MN), and DNA damage as determined by the Comet assay. The dose-dependent induction of genotoxicity of the silver ion (Ag(+)) and AgNPs was in the order Ag(+)>AgNPII>AgNPI>AgNPIV>AgNPIII that corresponded with their relative potencies of induction of DNA damage and oxidative stress. Furthermore, the findings underscored the CA and MN endpoint-based genotoxicity assay which demonstrated the genotoxicity of AgNPs at concentrations (≤10mgL(-1)) lower than that (≥10mgL(-1)) tested in the Comet assay. This study demonstrated the protective action of PVPP against the genotoxicity of AgNPIII which was independent of the size of the AgNPs in the L. sativus L. root bioassay system.
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http://dx.doi.org/10.1016/j.mrgentox.2016.05.006DOI Listing
August 2016

Correction of MFG-E8 Resolves Inflammation and Promotes Cutaneous Wound Healing in Diabetes.

J Immunol 2016 06 18;196(12):5089-100. Epub 2016 May 18.

Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210; Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210; Comprehensive Wound Center, Center for Regenerative Medicine and Cell Based Therapies, Ohio State University Wexner Medical Center, Columbus, OH 43210;

Milk fat globule epidermal growth factor-factor 8 (MFG-E8) is a peripheral glycoprotein that acts as a bridging molecule between the macrophage and apoptotic cells, thus executing a pivotal role in the scavenging of apoptotic cells from affected tissue. We have previously reported that apoptotic cell clearance activity or efferocytosis is compromised in diabetic wound macrophages. In this work, we test the hypothesis that MFG-E8 helps resolve inflammation, supports angiogenesis, and accelerates wound closure. MFG-E8(-/-) mice displayed impaired efferocytosis associated with exaggerated inflammatory response, poor angiogenesis, and wound closure. Wound macrophage-derived MFG-E8 was recognized as a critical driver of wound angiogenesis. Transplantation of MFG-E8(-/-) bone marrow to MFG-E8(+/+) mice resulted in impaired wound closure and compromised wound vascularization. In contrast, MFG-E8(-/-) mice that received wild-type bone marrow showed improved wound closure and improved wound vascularization. Hyperglycemia and exposure to advanced glycated end products inactivated MFG-E8, recognizing a key mechanism that complicates diabetic wound healing. Diabetic db/db mice suffered from impaired efferocytosis accompanied with persistent inflammation and slow wound closure. Topical recombinant MFG-E8 induced resolution of wound inflammation, improvements in angiogenesis, and acceleration of closure, upholding the potential of MFG-E8-directed therapeutics in diabetic wound care.
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http://dx.doi.org/10.4049/jimmunol.1502270DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5090174PMC
June 2016

ACTIN-DIRECTED TOXIN. ACD toxin-produced actin oligomers poison formin-controlled actin polymerization.

Science 2015 Jul;349(6247):535-9

Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA. The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.

The actin cross-linking domain (ACD) is an actin-specific toxin produced by several pathogens, including life-threatening spp. of Vibrio cholerae, Vibrio vulnificus, and Aeromonas hydrophila. Actin cross-linking by ACD is thought to lead to slow cytoskeleton failure owing to a gradual sequestration of actin in the form of nonfunctional oligomers. Here, we found that ACD converted cytoplasmic actin into highly toxic oligomers that potently "poisoned" the ability of major actin assembly proteins, formins, to sustain actin polymerization. Thus, ACD can target the most abundant cellular protein by using actin oligomers as secondary toxins to efficiently subvert cellular functions of actin while functioning at very low doses.
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http://dx.doi.org/10.1126/science.aab4090DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4648357PMC
July 2015

Antioxidants in Longevity and Medicine 2014.

Oxid Med Cell Longev 2015 11;2015:739417. Epub 2015 May 11.

Department of Surgery, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06032, USA.

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http://dx.doi.org/10.1155/2015/739417DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4442303PMC
April 2016

The mitochondrial cardiolipin remodeling enzyme lysocardiolipin acyltransferase is a novel target in pulmonary fibrosis.

Am J Respir Crit Care Med 2014 Jun;189(11):1402-15

1 Department of Pharmacology.

Rationale: Lysocardiolipin acyltransferase (LYCAT), a cardiolipin-remodeling enzyme regulating the 18:2 linoleic acid pattern of mammalian mitochondrial cardiolipin, is necessary for maintaining normal mitochondrial function and vascular development. We hypothesized that modulation of LYCAT expression in lung epithelium regulates development of pulmonary fibrosis.

Objectives: To define a role for LYCAT in human and murine models of pulmonary fibrosis.

Methods: We analyzed the correlation of LYCAT expression in peripheral blood mononuclear cells (PBMCs) with the outcomes of pulmonary functions and overall survival, and used the murine models to establish the role of LYCAT in fibrogenesis. We studied the LYCAT action on cardiolipin remodeling, mitochondrial reactive oxygen species generation, and apoptosis of alveolar epithelial cells under bleomycin challenge.

Measurements And Main Results: LYCAT expression was significantly altered in PBMCs and lung tissues from patients with idiopathic pulmonary fibrosis (IPF), which was confirmed in two preclinical murine models of IPF, bleomycin- and radiation-induced pulmonary fibrosis. LYCAT mRNA expression in PBMCs directly and significantly correlated with carbon monoxide diffusion capacity, pulmonary function outcomes, and overall survival. In both bleomycin- and radiation-induced pulmonary fibrosis murine models, hLYCAT overexpression reduced several indices of lung fibrosis, whereas down-regulation of native LYCAT expression by siRNA accentuated fibrogenesis. In vitro studies demonstrated that LYCAT modulated bleomycin-induced cardiolipin remodeling, mitochondrial membrane potential, reactive oxygen species generation, and apoptosis of alveolar epithelial cells, potential mechanisms of LYCAT-mediated lung protection.

Conclusions: This study is the first to identify modulation of LYCAT expression in fibrotic lungs and offers a novel therapeutic approach for ameliorating lung inflammation and pulmonary fibrosis.
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http://dx.doi.org/10.1164/rccm.201310-1917OCDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4098083PMC
June 2014

Airborne agricultural particulate matter induces inflammatory cytokine secretion by respiratory epithelial cells: mechanisms of regulation by eicosanoid lipid signal mediators.

Indian J Biochem Biophys 2013 Oct;50(5):387-401

The purpose of this study was to elucidate the mechanism of the airborne poultry dust (particulate matter, PM)-induced respiratory tract inflammation, a common symptom in agricultural respiratory diseases. The study was based on the hypothesis that poultry PM would induce the release of inflammatory cytokine interleukin-8 (IL-8) by respiratory epithelial cells under the upstream regulation by cytosolic phospholipase A2 (cPLA2) activation and subsequent formation of cyclooxygenase (COX)- and lipoxygenase (LOX)-catalyzed arachidonic acid (AA) metabolites (eicosanoids). Human lung epithelial cells (A549) in culture were treated with the poultry PM (0.1-1.0 mg) for different lengths of time, following which PLA2 activity, release of eicosanoids and secretion of IL-8 in cells were determined. Poultry PM (1.0 mg/ml) caused a significant activation of PLA2 in a time-dependent manner (15-60 min), which was significantly attenuated by the calcium-chelating agents, cPLA2-specific inhibitor (AACOCF3) and antioxidant (vitamin C) in A549 cells. Poultry PM also significantly induced the release of COX- and LOX-catalyzed eicosanoids (prostaglandins, thromboxane A2 and leukotrienes B4 and C4) and upstream activation of AA LOX in the cells. Poultry PM also significantly induced release of IL-8 by the cells in a dose- and time-dependent manner, which was significantly attenuated by the calcium chelating agents, antioxidants and COX- and LOX-specific inhibitors. The current study for the first time revealed that the poultry PM-induced IL-8 release from the respiratory epithelial cells was regulated upstream by reactive oxygen species, cPLA2-, COX- and LOX-derived eicosanoid lipid signal mediators.
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October 2013

Antioxidants in longevity and medicine.

Oxid Med Cell Longev 2013 12;2013:820679. Epub 2013 Nov 12.

Department of Surgery, University of Connecticut Health Center, Farmington, CT-06030, USA.

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http://dx.doi.org/10.1155/2013/820679DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3845868PMC
July 2014

Conundrum of pathogenesis of diabetic cardiomyopathy: role of vascular endothelial dysfunction, reactive oxygen species, and mitochondria.

Mol Cell Biochem 2014 Jan 4;386(1-2):233-49. Epub 2013 Dec 4.

Department of Surgery, University of Connecticut Health Center, Farmington Avenue, Farmington, CT, 06032, USA.

Diabetic cardiomyopathy and heart failure have been recognized as the leading causes of mortality among diabetics. Diabetic cardiomyopathy has been characterized primarily by the manifestation of left ventricular dysfunction that is independent of coronary artery disease and hypertension among the patients affected by diabetes mellitus. A complex array of contributing factors including the hypertrophy of left ventricle, alterations of metabolism, microvascular pathology, insulin resistance, fibrosis, apoptotic cell death, and oxidative stress have been implicated in the pathogenesis of diabetic cardiomyopathy. Nevertheless, the exact mechanisms underlying the pathogenesis of diabetic cardiomyopathy are yet to be established. The critical involvement of multifarious factors including the vascular endothelial dysfunction, microangiopathy, reactive oxygen species (ROS), oxidative stress, mitochondrial dysfunction has been identified in the mechanism of pathogenesis of diabetic cardiomyopathy. Although it is difficult to establish how each factor contributes to disease, the involvement of ROS and mitochondrial dysfunction are emerging as front-runners in the mechanism of pathogenesis of diabetic cardiomyopathy. This review highlights the role of vascular endothelial dysfunction, ROS, oxidative stress, and mitochondriopathy in the pathogenesis of diabetic cardiomyopathy. Furthermore, the review emphasizes that the puzzle has to be solved to firmly establish the mitochondrial and/or ROS mechanism(s) by identifying their most critical molecular players involved at both spatial and temporal levels in diabetic cardiomyopathy as targets for specific and effective pharmacological/therapeutic interventions.
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http://dx.doi.org/10.1007/s11010-013-1861-xDOI Listing
January 2014

Molecular mechanisms of action and therapeutic uses of pharmacological inhibitors of HIF-prolyl 4-hydroxylases for treatment of ischemic diseases.

Antioxid Redox Signal 2014 Jun 31;20(16):2631-65. Epub 2013 Oct 31.

1 Molecular Cardiology and Angiogenesis Laboratory, Department of Surgery, University of Connecticut Health Center , Farmington, Connecticut.

Significance: In this review, we have discussed the efficacy and effect of small molecules that act as prolyl hydroxylase domain inhibitors (PHDIs). The use of these compounds causes upregulation of the pro-angiogenic factors and hypoxia inducible factor-1α and -2α (HIF-1α and HIF-2α) to enhance angiogenic, glycolytic, erythropoietic, and anti-apoptotic pathways in the treatment of various ischemic diseases responsible for significant morbidity and mortality in humans.

Recent Advances: Sprouting of new blood vessels from the existing vasculature and surgical intervention, such as coronary bypass and stent insertion, have been shown to be effective in attenuating ischemia. However, the initial reentry of oxygen leads to the formation of reactive oxygen species that cause oxidative stress and result in ischemia/reperfusion (IR) injury. This apparent "oxygen paradox" must be resolved to combat IR injury. During hypoxia, decreased activity of PHDs initiates the accumulation and activation of HIF-1α, wherein the modulation of both PHD and HIF-1α appears as promising therapeutic targets for the pharmacological treatment of ischemic diseases.

Critical Issues: Research on PHDs and HIFs has shown that these molecules can serve as therapeutic targets for ischemic diseases by modulating glycolysis, erythropoiesis, apoptosis, and angiogenesis. Efforts are underway to identify and synthesize safer small-molecule inhibitors of PHDs that can be administered in vivo as therapy against ischemic diseases.

Future Directions: This review presents a comprehensive and current account of the existing small-molecule PHDIs and their use in the treatment of ischemic diseases with a focus on the molecular mechanisms of therapeutic action in animal models.
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http://dx.doi.org/10.1089/ars.2013.5186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4026215PMC
June 2014

Phospholipase D signaling mediates reactive oxygen species-induced lung endothelial barrier dysfunction.

Pulm Circ 2013 Jan;3(1):108-15

Department of Pharmacology and Institute for Personalized Respiratory Medicine, University of Illinois, Chicago, IL, USA.

Reactive oxygen species (ROS) have emerged as critical players in the pathophysiology of pulmonary disorders and diseases. Earlier, we have demonstrated that ROS stimulate lung endothelial cell (EC) phospholipase D (PLD) that generates phosphatidic acid (PA), a second messenger involved in signal transduction. In the current study, we investigated the role of PLD signaling in the ROS-induced lung vascular EC barrier dysfunction. Our results demonstrated that hydrogen peroxide (H2O2), a typical physiological ROS, induced PLD activation and altered the barrier function in bovine pulmonary artery ECs (BPAECs). 1-Butanol, the quencher of PLD, generated PA leading to the formation of physiologically inactive phosphatidyl butanol but not its biologically inactive analog, 2-butanol, blocked the H2O2-mediated barrier dysfunction. Furthermore, cell permeable C2 ceramide, an inhibitor of PLD but not the C2 dihydroceramide, attenuated the H2O2-induced PLD activation and enhancement of paracellular permeability of Evans blue conjugated albumin across the BPAEC monolayers. In addition, transfection of BPAECs with adenoviral constructs of hPLD1 and mPLD2 mutants attenuated the H2O2-induced barrier dysfunction, cytoskeletal reorganization and distribution of focal adhesion proteins. For the first time, this study demonstrated that the PLD-generated intracellular bioactive lipid signal mediator, PA, played a critical role in the ROS-induced barrier dysfunction in lung vascular ECs. This study also underscores the importance of PLD signaling in vascular leak and associated tissue injury in the etiology of lung diseases among critically ill patients encountering oxygen toxicity and excess ROS production during ventilator-assisted breathing.
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http://dx.doi.org/10.4103/2045-8932.109925DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3641713PMC
January 2013

Calcium channel blockers protect against aluminium-induced DNA damage and block adaptive response to genotoxic stress in plant cells.

Mutat Res 2013 Mar 8;751(2):130-8. Epub 2013 Jan 8.

Department of Botany, Berhampur University, Berhampur, India.

Calcium is an important second messenger in signal transduction pathways. The role of Ca(2+) signalling in Al-induced DNA damage, cell death, and adaptive response to genotoxic stress caused by ethyl methanesulfonate (EMS) or methylmercuric chloride (MMCl) in the root cells of Allium cepa was investigated in the current study. Root cells in planta were treated with Al(3+) (800μM of AlCl(3)) for 3h without or with 2h pre-treatment with the Ca(2+) chelator (EGTA) or Ca(2+) channel blockers (lanthanum chloride, verapamil) or CaM/CDPK antagonist (W7). In addition, root cells in planta were conditioned by treatment with Al(3+) (5 or 10μM of AlCl(3)) for 2h followed by the genotoxic challenge with MMCl (1.25μM) or EMS (2.5 or 5mM) for 3h without or with the pre-treatment of the chosen Ca(2+) chelator/channel blockers/antagonist. Following the treatments, cell death and DNA damage were investigated in the root cells by comet assay. Furthermore, genotoxicity in the root meristems was determined after 18-30h of recovery. These results revealed that Al(3+) (800μM) significantly induced DNA damage and cell death in the root cells of A. cepa. On the other hand, conditioning of the root cells with Al(3+) at low concentrations (5 or 10μM) offered adaptive response leading to the protection against genotoxic stress induced by MMCl and EMS. Pre-treatment of root cells with the Ca(2+) chelator/channel blockers/antagonist not only alleviated Al(3+)-induced DNA damage and cell death induced but also blocked the Al(3+)-mediated adaptive response to genotoxic stress induced by MMCl and EMS. For the first time, the results of the present study highlighted the role of Ca(2+) signalling underlying the biphasic mode of action of Al(3+) that induced DNA damage and cell death at high doses and offered adaptation to genotoxic response in plants at low doses.
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http://dx.doi.org/10.1016/j.mrgentox.2012.12.008DOI Listing
March 2013

Choice of cyclodextrin for cellular cholesterol depletion for vascular endothelial cell lipid raft studies: cell membrane alterations, cytoskeletal reorganization and cytotoxicity.

Indian J Biochem Biophys 2012 Oct;49(5):329-41

Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, OH 43210, USA.

The use of cyclodextrins as tools to establish the role of cholesterol rafts in cellular functions has become a widely accepted procedure. However, the adverse effects of cyclodextrins as the cholesterol-depleting agents on cellular structure and functions are not reported in detail. Therefore, in the current study, we investigated the membrane-perturbing actions and cytotoxicity of the two widely used cellular cholesterol-depleting cyclodextrins methyl-beta-cyclodextrin (MbetaCD) and hydroxypropyl-beta-cyclodextrin (HPCD) in our well-established bovine pulmonary artery endothelial cell (BPAEC) in vitro model system. BPAECs treated with different concentrations of MbetaCD and HPCD (2% and 5%, wt/vol.) for 15-180 min showed significant loss of membrane cholesterol, cytotoxicity, cell morphology alterations, actin cytoskeletal reorganization, alterations in cellular proteins and membrane fatty acid composition, and decrease in trans-endothelial electrical resistance (TER). MbetaCD induced a marked loss of cellular proteins, as compared to that caused by HPCD under identical conditions. More noticeably, MbetaCD caused a drastic loss of membrane lipid fatty acids in BPAECs, as compared to HPCD which failed to cause such alteration. Removal of cholesterol by cyclodextrin (especially MbetaCD) treatment apparently caused loss of fluidity of the cell membrane and leakage of vital cellular molecules including proteins and fatty acids, and thus caused cytotoxicity and loss of cell morphology in BPAECs. Replenishment of cells with cholesterol following its depletion by MbetaCD treatment significantly attenuated the depletion of cellular cholesterol, cytotoxicity and morphological alterations in BPAECs, indicating the importance of membrane cholesterol in vascular EC integrity. Also, the current study offered a safer method of cholesterol removal from membranes and lipid rafts by HPCD, suggesting its use in studies to investigate the role of lipid raft-associated cholesterol in cellular functions.
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October 2012

Regulation of the MIR155 host gene in physiological and pathological processes.

Gene 2013 Dec 14;532(1):1-12. Epub 2012 Dec 14.

Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; College of Pharmacy, Division of Pharmacology, The Ohio State University, Columbus, OH, USA; Department of Medicine, Division of Cardiology, The Ohio State University, Columbus, OH, USA. Electronic address:

MicroRNAs (miRNAs), a family of small nonprotein-coding RNAs, play a critical role in posttranscriptional gene regulation by acting as adaptors for the miRNA-induced silencing complex to inhibit gene expression by targeting mRNAs for translational repression and/or cleavage. miR-155-5p and miR-155-3p are processed from the B-cell Integration Cluster (BIC) gene (now designated, MIR155 host gene or MIR155HG). MiR-155-5p is highly expressed in both activated B- and T-cells and in monocytes/macrophages. MiR-155-5p is one of the best characterized miRNAs and recent data indicate that miR-155-5p plays a critical role in various physiological and pathological processes such as hematopoietic lineage differentiation, immunity, inflammation, viral infections, cancer, cardiovascular disease, and Down syndrome. In this review we summarize the mechanisms by which MIR155HG expression can be regulated. Given that the pathologies mediated by miR-155-5p result from the over-expression of this miRNA it may be possible to therapeutically attenuate miR-155-5p levels in the treatment of several pathological processes.
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http://dx.doi.org/10.1016/j.gene.2012.12.009DOI Listing
December 2013

Aluminum induces oxidative burst, cell wall NADH peroxidase activity, and DNA damage in root cells of Allium cepa L.

Environ Mol Mutagen 2012 Aug 2;53(7):550-60. Epub 2012 Aug 2.

Department of Botany, Molecular Biology and Genomics Laboratory, Berhampur University, Berhampur, India.

Plants under stress incur an oxidative burst that involves a rapid and transient overproduction of reactive oxygen species (ROS: O(2) (•-) , H(2) O(2) , (•) OH). We hypothesized that aluminum (Al), an established soil pollutant that causes plant stress, would induce an oxidative burst through the activation of cell wall-NADH peroxidase (NADH-PX) and/or plasma membrane-associated NADPH oxidase (NADPH-OX), leading to DNA damage in the root cells of Allium cepa L. Growing roots of A. cepa were treated with Al(3+) (800 μM of AlCl(3) ) for 3 or 6 hr without or with the pretreatment of inhibitors specific to NADH-PX and NADPH-OX for 2 hr. At the end of the treatment, the extent of ROS generation, cell death, and DNA damage were determined. The cell wall-bound protein (CWP) fractions extracted from the untreated control and the Al-treated roots under the aforementioned experimental conditions were also subjected to in vitro studies, which measured the extent of activation of peroxidase/oxidase, generation of (•) OH, and DNA damage. Overall, the present study demonstrates that the cell wall-bound NADH-PX contributes to the Al-induced oxidative burst through the generation of ROS that lead to cell death and DNA damage in the root cells of A. cepa. Furthermore, the in vitro studies revealed that the CWP fraction by itself caused DNA damage in the presence of NADH, supporting a role for NADH-PX in the stress response. Altogether, this study underscores the crucial function of the cell wall-bound NADH-PX in the oxidative burst-mediated cell death and DNA damage in plants under Al stress.
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http://dx.doi.org/10.1002/em.21719DOI Listing
August 2012

Prostaglandin E₂ induces oncostatin M expression in human chronic wound macrophages through Axl receptor tyrosine kinase pathway.

J Immunol 2012 Sep 27;189(5):2563-73. Epub 2012 Jul 27.

Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.

Monocytes and macrophages (m) are plastic cells whose functions are governed by microenvironmental cues. Wound fluid bathing the wound tissue reflects the wound microenvironment. Current literature on wound inflammation is primarily based on the study of blood monocyte-derived macrophages, cells that have never been exposed to the wound microenvironment. We sought to compare pair-matched monocyte-derived macrophages with m isolated from chronic wounds of patients. Oncostatin M (OSM) was differentially overexpressed in pair-matched wound m. Both PGE₂ and its metabolite 13,14-dihydro-15-keto-PGE₂ (PGE-M) were abundant in wound fluid and induced OSM in wound-site m. Consistently, induction of OSM mRNA was observed in m isolated from PGE₂-enriched polyvinyl alcohol sponges implanted in murine wounds. Treatment of human THP-1 cell-derived m with PGE₂ or PGE-M caused dose-dependent induction of OSM. Characterization of the signal transduction pathways demonstrated the involvement of EP4 receptor and cAMP signaling. In human m, PGE₂ phosphorylated Axl, a receptor tyrosine kinase (RTK). Axl phosphorylation was also induced by a cAMP analogue demonstrating interplay between the cAMP and RTK pathways. PGE₂-dependent Axl phosphorylation led to AP-1 transactivation, which is directly implicated in inducible expression of OSM. Treatment of human m or mice excisional wounds with recombinant OSM resulted in an anti-inflammatory response as manifested by attenuated expression of endotoxin-induced TNF-α and IL-1β. OSM treatment also improved wound closure during the early inflammatory phase of healing. In summary, this work recognizes PGE₂ in the wound fluid as a potent inducer of m OSM, a cytokine with an anti-inflammatory role in cutaneous wound healing.
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http://dx.doi.org/10.4049/jimmunol.1102762DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3438225PMC
September 2012

Thiol-redox antioxidants protect against lung vascular endothelial cytoskeletal alterations caused by pulmonary fibrosis inducer, bleomycin: comparison between classical thiol-protectant, N-acetyl-L-cysteine, and novel thiol antioxidant, N,N'-bis-2-mercaptoethyl isophthalamide.

Toxicol Mech Methods 2012 Jun;22(5):383-96

Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio, USA.

Lung vascular alterations and pulmonary hypertension associated with oxidative stress have been reported to be involved in idiopathic lung fibrosis (ILF). Therefore, here, we hypothesize that the widely used lung fibrosis inducer, bleomycin, would cause cytoskeletal rearrangement through thiol-redox alterations in the cultured lung vascular endothelial cell (EC) monolayers. We exposed the monolayers of primary bovine pulmonary artery ECs to bleomycin (10 µg) and studied the cytotoxicity, cytoskeletal rearrangements, and the macromolecule (fluorescein isothiocyanate-dextran, 70,000 mol. wt.) paracellular transport in the absence and presence of two thiol-redox protectants, the classic water-soluble N-acetyl-L-cysteine (NAC) and the novel hydrophobic N,N'-bis-2-mercaptoethyl isophthalamide (NBMI). Our results revealed that bleomycin induced cytotoxicity (lactate dehydrogenase leak), morphological alterations (rounding of cells and filipodia formation), and cytoskeletal rearrangement (actin stress fiber formation and alterations of tight junction proteins, ZO-1 and occludin) in a dose-dependent fashion. Furthermore, our study demonstrated the formation of reactive oxygen species, loss of thiols (glutathione, GSH), EC barrier dysfunction (decrease of transendothelial electrical resistance), and enhanced paracellular transport (leak) of macromolecules. The observed bleomycin-induced EC alterations were attenuated by both NAC and NBMI, revealing that the novel hydrophobic thiol-protectant, NBMI, was more effective at µM concentrations as compared to the water-soluble NAC that was effective at mM concentrations in offering protection against the bleomycin-induced EC alterations. Overall, the results of the current study suggested the central role of thiol-redox in vascular EC dysfunction associated with ILF.
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http://dx.doi.org/10.3109/15376516.2012.673089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3914546PMC
June 2012

Phytochemical antioxidants modulate mammalian cellular epigenome: implications in health and disease.

Antioxid Redox Signal 2012 Jul 17;17(2):327-39. Epub 2012 Apr 17.

Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Lipid Signaling, Lipidomics, and Vasculotoxicity Laboratory, Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, Ohio 43210, USA.

Unlabelled: In living systems, the mechanisms of inheritance involving gene expression are operated by (i) the traditional model of genetics where the deoxyribonucleic acid (DNA) transcription and messenger ribonucleic acid stability are influenced by the DNA sequences and any aberrations in the primary DNA sequences and (ii) the epigenetic (above genetics) model in which the gene expression is regulated by mechanisms other than the changes in DNA sequences. The widely studied epigenetic alterations include DNA methylation, covalent modification of chromatin structure, state of histone acetylation, and involvement of microribonucleic acids.

Significance: Currently, the role of cellular epigenome in health and disease is rapidly emerging. Several factors are known to modulate the epigenome-regulated gene expression that is crucial in several pathophysiological states and diseases in animals and humans. Phytochemicals have occupied prominent roles in human diet and nutrition as protective antioxidants in prevention/protection against several disorders and diseases in humans.

Recent Advances: However, it is beginning to surface that the phytochemical phenolic antioxidants such as polyphenols, flavonoids, and nonflavonoid phenols function as potent modulators of the mammalian epigenome-regulated gene expression through regulation of DNA methylation, histone acetylation, and histone deacetylation in experimental models.

Critical Issues And Future Directions: The antioxidant or pro-oxidant actions and their involvement in the epigenome regulation by the phytochemical phenolic antioxidants should be at least established in the cellular models under normal and pathophysiological states. The current review discusses the mechanisms of modulation of the mammalian cellular epigenome by the phytochemical phenolic antioxidants with implications in human diseases.
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http://dx.doi.org/10.1089/ars.2012.4600DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3353820PMC
July 2012

M-CSF induces monocyte survival by activating NF-κB p65 phosphorylation at Ser276 via protein kinase C.

PLoS One 2011 22;6(12):e28081. Epub 2011 Dec 22.

Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA.

Macrophage colony-stimulating factor (M-CSF) promotes mononuclear phagocyte survival and proliferation. The transcription factor Nuclear Factor-kappaB (NF-κB) is a key regulator of genes involved in M-CSF-induced mononuclear phagocyte survival and this study focused at identifying the mechanism of NF-κB transcriptional activation. Here, we demonstrate that M-CSF stimulated NF-κB transcriptional activity in human monocyte-derived macrophages (MDMs) and the murine macrophage cell line RAW 264.7. The general protein kinase C (PKC) inhibitor Ro-31-8220, the conventional PKCα/β inhibitor Gö-6976, overexpression of dominant negative PKCα constructs and PKCα siRNA reduced NF-κB activity in response to M-CSF. Interestingly, Ro-31-8220 reduced Ser276 phosphorylation of NF-κBp65 leading to decreased M-CSF-induced monocyte survival. In this report, we identify conventional PKCs, including PKCα as important upstream kinases for M-CSF-induced NF-κB transcriptional activation, NF-κB-regulated gene expression, NF-κB p65 Ser276 phosphorylation, and macrophage survival. Lastly, we find that NF-κB p65 Ser276 plays an important role in basal and M-CSF-stimulated NF-κB activation in human mononuclear phagocytes.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028081PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3245220PMC
May 2012