Sainath Kotha MD | University of Illinois at Chicago (original) (raw)

Papers by Sainath Kotha MD

Research paper thumbnail of Phospholipase D signaling mediates reactive oxygen species-induced lung endothelial barrier dysfunction

Reactive oxygen species (ROS) have emerged as critical players in the pathophysiology of pulmonar... more 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 (H 2 O 2), 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 H 2 O 2-mediated barrier dysfunction. Furthermore, cell permeable C2 ceramide, an inhibitor of PLD but not the C2 dihydroceramide, attenuated the H 2 O 2-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 hPLD 1 and mPLD 2 mutants attenuated the H 2 O 2-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.

Research paper thumbnail of Inflammatory Lipidomics of Sickle Cell Disease, Potential Biomarkers, and Therapeutic Targets

Research paper thumbnail of Lysocardiolipin acyltransferase regulates NSCLC cell proliferation and migration by modulating mitochondrial dynamics

Journal of Biological Chemistry, 2020

Lysocardiolipin acyltransferase (LYCAT), a cardiolipin (CL)-remodeling enzyme, is crucial for mai... more Lysocardiolipin acyltransferase (LYCAT), a cardiolipin (CL)-remodeling enzyme, is crucial for maintaining normal mitochondrial function and vascular development. Despite the wellcharacterized role for LYCAT in the regulation of mitochondrial dynamics, it's involvement in lung cancer, if any, remains incompletely understood. In this study, in silico analysis of TCGA lung cancer datasets revealed a significant increase in LYCAT expression, which was later corroborated in human lung cancer tissues and immortalized lung cancer cell lines via indirect immunofluorescence and immunoblotting, respectively. Stable knockdown of LYCAT in NSCLC cell lines not only reduced CL and increased monolyso CL levels but also reduced in vivo tumor growth, as determined by xenograft studies in athymic nude mice. Furthermore, blocking LYCAT activity using a LYCAT mimetic peptide, attenuated cell migration, suggesting a novel role for LYCAT activity in promoting NSCLC. Mechanistically, the pro-proliferative effects of LYCAT were mediated by an increase in mitochondrial fusion, and a G1/S cell cycle transition, both of which are linked to increased cell proliferation. Taken together, these results demonstrate a novel role for LYCAT in promoting NSCLC and suggests that targeting LYCAT expression or activity in NSCLC may provide new avenues for the therapeutic treatment of lung cancer.

Research paper thumbnail of Pentalinonsterol exhibits the immunomodulatory action in macrophages through activation of Phospholipase A 2

Research paper thumbnail of PulmCirc-2013-3-1-108-109925-4892321 133523

Research paper thumbnail of The mitochondrial cardiolipin remodeling enzyme lysocardiolipin acyltransferase is a novel target in pulmonary fibrosis

American journal of respiratory and critical care medicine, 2014

Lysocardiolipin acyltransferase (LYCAT), a cardiolipin-remodeling enzyme regulating the 18:2 lino... more 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. To define a role for LYCAT in human and murine models of pulmonary fibrosis. 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. LYCAT expression was significantly altered in PBMCs and lung tissues from patients with idiopathic pulmonary fibrosis (IPF), which was confirmed in two precl...

Research paper thumbnail of Pentalinonsterol, a Phytosterol from Pentalinon andrieuxii, is Immunomodulatory through Phospholipase A2 in Macrophages toward its Antileishmanial Action

Cell Biochemistry and Biophysics, 2021

Our earlier in vitro and in vivo studies have revealed that the phytosterol, pentalinonsterol (ch... more Our earlier in vitro and in vivo studies have revealed that the phytosterol, pentalinonsterol (cholest-4,20,24-trien-3-one) (PEN), isolated from the roots of Pentalinon andrieuxii, possesss immunomodulatory properties in macrophages and dendritic cells. Leishmaniasis, caused by the infection of Leishmania spp. (a protozoan parasite), is emerging as the second-leading cause of mortality among the tropical diseases and there is an unmet need for a pharmacological intervention of leishmaniasis. Given the beneficial immunomodulatory actions and lipophilic properties of PEN, the objective of this study was to elucidate the mechanism(s) of action of the immunomodulatory action(s) of PEN in macrophages through the modulation of phospholipase A2 (PLA2) activity that might be crucial in the antileishmanial action of PEN. Therefore, in this study, we investigated whether PEN would modulate the activity of PLA2 in RAW 264.7 macrophages and mouse bone marrow-derived primary macrophages (BMDMs) in vitro and further determined how the upstream PLA2 activation would regulate the downstream cytokine release in the macrophages. Our current results demonstrated that (i) PEN induced PLA2 activation (arachidonic acid release) in a dose- and time-dependent manner that was regulated upstream by the mitogen-activated protein kinases (MAPKs); (ii) the PEN-induced activation of PLA2 was attenuated by the cPLA2-specific pharmacological inhibitors; and (iii) the cPLA2-specific pharmacological inhibitors attenuated the release of inflammatory cytokines from the macrophages. For the first time, our current study demonstrated that PEN exhibited its immunomodulatory actions through the activation of cPLA2 in the macrophages, which potentially could be used in the development of a pharmacological intervention against leishmaniasis.

Research paper thumbnail of Effects Of Intermittent Hypoxia On Glucose Tolerance In Female TALLYHO/JngJ Mice

B73. SLEEP DISORDERED BREATHING AND CONTROL OF VENTILATION: BASIC AND TRANSLATIONAL ASPECTS, 2010

ABSTRACT

Research paper thumbnail of Adipokines and Sleep Disorders

Research paper thumbnail of Bioactive Phospholipid Mediators of Inflammation

Molecular Pathophysiology, Nutritional and Therapeutic Interventions, 2012

Research paper thumbnail of Lipidomics – A Novel Strategy for Probing into Systems Biology Operations: Networking between Glycome, Lipidome, Proteome, and Genome

Journal of Glycomics & Lipidomics, 2011

Research paper thumbnail of Effects Of Intermittent Hypoxia On Glucose Tolerance In Female TALLYHO/JngJ Mice

B73. SLEEP DISORDERED BREATHING AND CONTROL OF VENTILATION: BASIC AND TRANSLATIONAL ASPECTS, 2010

ABSTRACT

Research paper thumbnail of Novel Lipid-Soluble Thiol-Redox Antioxidant and Heavy Metal Chelator, N,N'-bis(2-Mercaptoethyl)Isophthalamide (NBMI) and Phospholipase D-Specific Inhibitor, 5-Fluoro-2-Indolyl Des-Chlorohalopemide (FIPI) Attenuate Mercury-Induced Lipid Signaling Leading to Protection Against Cytotoxicity in Aorti...

International Journal of Toxicology, 2011

Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of merc... more Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of mercury cytotoxicity in mouse aortic endothelial cell (MAEC) in vitro model utilizing the novel lipid-soluble thiol-redox antioxidant and heavy metal chelator, N,N'-bis(2-mercaptoethyl)isophthalamide (NBMI) and the novel PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). Our results demonstrated (i) mercury in the form of mercury(II) chloride, methylmercury, and thimerosal induced PLD activation in a dose- and time-dependent manner; (ii) NBMI and FIPI completely attenuated mercury- and oxidant-induced PLD activation; (iii) mercury induced upstream phosphorylation of extracellular-regulated kinase 1/2 (ERK1/2) leading to downstream threonine phosphorylation of PLD(1) which was attenuated by NBMI; (iv) mercury caused loss of intracellular glutathione which was restored by NBMI; and (v) NBMI and FIPI attenuated mercury- and oxidant-induced cytotoxicity in MAECs. For the first time, this study demonstrated that redox-dependent and PLD-mediated bioactive lipid signaling was involved in mercury-induced vascular EC cytotoxicity which was protected by NBMI and FIPI.

Research paper thumbnail of A novel sterol isolated from a plant used by Mayan traditional healers is effective in treatment of visceral leishmaniasis caused by Leishmania donovani

ACS Infectious Diseases, 2015

Research paper thumbnail of Pulmonary Fibrosis Inducer, Bleomycin, Activates Phospholipase D and Generates Bioactive Lipid Signal Mediator, Phosphatidic Acid in Lung Microvascular Endothelial Cells

Research paper thumbnail of ACTIN-DIRECTED TOXIN. ACD toxin-produced actin oligomers poison formin-controlled actin polymerization

Science (New York, N.Y.), Jan 31, 2015

The actin cross-linking domain (ACD) is an actin-specific toxin produced by several pathogens, in... more 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.

Research paper thumbnail of PulmCirc-2013-3-1-108-109925-4892321 133523

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

Indian journal of biochemistry & biophysics, 2013

The purpose of this study was to elucidate the mechanism of the airborne poultry dust (particulat... more 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 (A...

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

Indian journal of biochemistry & biophysics, 2012

The use of cyclodextrins as tools to establish the role of cholesterol rafts in cellular function... more 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 ind...

Research paper thumbnail of MG29/SYPL2 Contributes to Dysregulation of Lipid Composition and Store Operated Ca2+ Entry in Aging Skeletal Muscle

Biophysical Journal, 2015

Research paper thumbnail of Phospholipase D signaling mediates reactive oxygen species-induced lung endothelial barrier dysfunction

Reactive oxygen species (ROS) have emerged as critical players in the pathophysiology of pulmonar... more 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 (H 2 O 2), 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 H 2 O 2-mediated barrier dysfunction. Furthermore, cell permeable C2 ceramide, an inhibitor of PLD but not the C2 dihydroceramide, attenuated the H 2 O 2-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 hPLD 1 and mPLD 2 mutants attenuated the H 2 O 2-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.

Research paper thumbnail of Inflammatory Lipidomics of Sickle Cell Disease, Potential Biomarkers, and Therapeutic Targets

Research paper thumbnail of Lysocardiolipin acyltransferase regulates NSCLC cell proliferation and migration by modulating mitochondrial dynamics

Journal of Biological Chemistry, 2020

Lysocardiolipin acyltransferase (LYCAT), a cardiolipin (CL)-remodeling enzyme, is crucial for mai... more Lysocardiolipin acyltransferase (LYCAT), a cardiolipin (CL)-remodeling enzyme, is crucial for maintaining normal mitochondrial function and vascular development. Despite the wellcharacterized role for LYCAT in the regulation of mitochondrial dynamics, it's involvement in lung cancer, if any, remains incompletely understood. In this study, in silico analysis of TCGA lung cancer datasets revealed a significant increase in LYCAT expression, which was later corroborated in human lung cancer tissues and immortalized lung cancer cell lines via indirect immunofluorescence and immunoblotting, respectively. Stable knockdown of LYCAT in NSCLC cell lines not only reduced CL and increased monolyso CL levels but also reduced in vivo tumor growth, as determined by xenograft studies in athymic nude mice. Furthermore, blocking LYCAT activity using a LYCAT mimetic peptide, attenuated cell migration, suggesting a novel role for LYCAT activity in promoting NSCLC. Mechanistically, the pro-proliferative effects of LYCAT were mediated by an increase in mitochondrial fusion, and a G1/S cell cycle transition, both of which are linked to increased cell proliferation. Taken together, these results demonstrate a novel role for LYCAT in promoting NSCLC and suggests that targeting LYCAT expression or activity in NSCLC may provide new avenues for the therapeutic treatment of lung cancer.

Research paper thumbnail of Pentalinonsterol exhibits the immunomodulatory action in macrophages through activation of Phospholipase A 2

Research paper thumbnail of PulmCirc-2013-3-1-108-109925-4892321 133523

Research paper thumbnail of The mitochondrial cardiolipin remodeling enzyme lysocardiolipin acyltransferase is a novel target in pulmonary fibrosis

American journal of respiratory and critical care medicine, 2014

Lysocardiolipin acyltransferase (LYCAT), a cardiolipin-remodeling enzyme regulating the 18:2 lino... more 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. To define a role for LYCAT in human and murine models of pulmonary fibrosis. 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. LYCAT expression was significantly altered in PBMCs and lung tissues from patients with idiopathic pulmonary fibrosis (IPF), which was confirmed in two precl...

Research paper thumbnail of Pentalinonsterol, a Phytosterol from Pentalinon andrieuxii, is Immunomodulatory through Phospholipase A2 in Macrophages toward its Antileishmanial Action

Cell Biochemistry and Biophysics, 2021

Our earlier in vitro and in vivo studies have revealed that the phytosterol, pentalinonsterol (ch... more Our earlier in vitro and in vivo studies have revealed that the phytosterol, pentalinonsterol (cholest-4,20,24-trien-3-one) (PEN), isolated from the roots of Pentalinon andrieuxii, possesss immunomodulatory properties in macrophages and dendritic cells. Leishmaniasis, caused by the infection of Leishmania spp. (a protozoan parasite), is emerging as the second-leading cause of mortality among the tropical diseases and there is an unmet need for a pharmacological intervention of leishmaniasis. Given the beneficial immunomodulatory actions and lipophilic properties of PEN, the objective of this study was to elucidate the mechanism(s) of action of the immunomodulatory action(s) of PEN in macrophages through the modulation of phospholipase A2 (PLA2) activity that might be crucial in the antileishmanial action of PEN. Therefore, in this study, we investigated whether PEN would modulate the activity of PLA2 in RAW 264.7 macrophages and mouse bone marrow-derived primary macrophages (BMDMs) in vitro and further determined how the upstream PLA2 activation would regulate the downstream cytokine release in the macrophages. Our current results demonstrated that (i) PEN induced PLA2 activation (arachidonic acid release) in a dose- and time-dependent manner that was regulated upstream by the mitogen-activated protein kinases (MAPKs); (ii) the PEN-induced activation of PLA2 was attenuated by the cPLA2-specific pharmacological inhibitors; and (iii) the cPLA2-specific pharmacological inhibitors attenuated the release of inflammatory cytokines from the macrophages. For the first time, our current study demonstrated that PEN exhibited its immunomodulatory actions through the activation of cPLA2 in the macrophages, which potentially could be used in the development of a pharmacological intervention against leishmaniasis.

Research paper thumbnail of Effects Of Intermittent Hypoxia On Glucose Tolerance In Female TALLYHO/JngJ Mice

B73. SLEEP DISORDERED BREATHING AND CONTROL OF VENTILATION: BASIC AND TRANSLATIONAL ASPECTS, 2010

ABSTRACT

Research paper thumbnail of Adipokines and Sleep Disorders

Research paper thumbnail of Bioactive Phospholipid Mediators of Inflammation

Molecular Pathophysiology, Nutritional and Therapeutic Interventions, 2012

Research paper thumbnail of Lipidomics – A Novel Strategy for Probing into Systems Biology Operations: Networking between Glycome, Lipidome, Proteome, and Genome

Journal of Glycomics & Lipidomics, 2011

Research paper thumbnail of Effects Of Intermittent Hypoxia On Glucose Tolerance In Female TALLYHO/JngJ Mice

B73. SLEEP DISORDERED BREATHING AND CONTROL OF VENTILATION: BASIC AND TRANSLATIONAL ASPECTS, 2010

ABSTRACT

Research paper thumbnail of Novel Lipid-Soluble Thiol-Redox Antioxidant and Heavy Metal Chelator, N,N'-bis(2-Mercaptoethyl)Isophthalamide (NBMI) and Phospholipase D-Specific Inhibitor, 5-Fluoro-2-Indolyl Des-Chlorohalopemide (FIPI) Attenuate Mercury-Induced Lipid Signaling Leading to Protection Against Cytotoxicity in Aorti...

International Journal of Toxicology, 2011

Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of merc... more Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of mercury cytotoxicity in mouse aortic endothelial cell (MAEC) in vitro model utilizing the novel lipid-soluble thiol-redox antioxidant and heavy metal chelator, N,N'-bis(2-mercaptoethyl)isophthalamide (NBMI) and the novel PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). Our results demonstrated (i) mercury in the form of mercury(II) chloride, methylmercury, and thimerosal induced PLD activation in a dose- and time-dependent manner; (ii) NBMI and FIPI completely attenuated mercury- and oxidant-induced PLD activation; (iii) mercury induced upstream phosphorylation of extracellular-regulated kinase 1/2 (ERK1/2) leading to downstream threonine phosphorylation of PLD(1) which was attenuated by NBMI; (iv) mercury caused loss of intracellular glutathione which was restored by NBMI; and (v) NBMI and FIPI attenuated mercury- and oxidant-induced cytotoxicity in MAECs. For the first time, this study demonstrated that redox-dependent and PLD-mediated bioactive lipid signaling was involved in mercury-induced vascular EC cytotoxicity which was protected by NBMI and FIPI.

Research paper thumbnail of A novel sterol isolated from a plant used by Mayan traditional healers is effective in treatment of visceral leishmaniasis caused by Leishmania donovani

ACS Infectious Diseases, 2015

Research paper thumbnail of Pulmonary Fibrosis Inducer, Bleomycin, Activates Phospholipase D and Generates Bioactive Lipid Signal Mediator, Phosphatidic Acid in Lung Microvascular Endothelial Cells

Research paper thumbnail of ACTIN-DIRECTED TOXIN. ACD toxin-produced actin oligomers poison formin-controlled actin polymerization

Science (New York, N.Y.), Jan 31, 2015

The actin cross-linking domain (ACD) is an actin-specific toxin produced by several pathogens, in... more 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.

Research paper thumbnail of PulmCirc-2013-3-1-108-109925-4892321 133523

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

Indian journal of biochemistry & biophysics, 2013

The purpose of this study was to elucidate the mechanism of the airborne poultry dust (particulat... more 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 (A...

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

Indian journal of biochemistry & biophysics, 2012

The use of cyclodextrins as tools to establish the role of cholesterol rafts in cellular function... more 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 ind...

Research paper thumbnail of MG29/SYPL2 Contributes to Dysregulation of Lipid Composition and Store Operated Ca2+ Entry in Aging Skeletal Muscle

Biophysical Journal, 2015