Susan M Majka

Vanderbilt University, Нашвилл, Michigan, United States

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Publications (55)244.86 Total impact

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    ABSTRACT: Excess superoxide has been implicated in pulmonary hypertension (PH). We previously found that lung overexpression of the antioxidant extracellular superoxide dismutase (EC-SOD) attenuates PH and vascular remodeling. Though comprising only a small fraction of total SOD activity in most tissues, EC-SOD is abundant in arteries. We hypothesize that the selective loss of vascular EC-SOD promotes hypoxia-induced PH through redox-sensitive signaling pathways. EC-SOD(loxp/loxp)× Tg(cre/SMMHC) mice (SMC EC-SOD KO) received tamoxifen to conditionally deplete smooth muscle cell (SMC)-derived EC-SOD. Mice were exposed to hypobaric hypoxia for 35 days and PH was assessed by RV systolic pressure measurements and RV hypertrophy. Vascular remodeling was evaluated by morphometric analysis and two-photon microscopy for collagen. We examined lung cyclic GMP content, soluble guanylate cyclase expression and activity, phosphodiesterase5 expression and activity, expression of total and active endothelial nitric oxide synthase and GTP cyclohydrolase-1 (GTPCH-1), the rate-limiting enzyme in tetrahydrobiopterin synthesis. Knockout of SMC EC-SOD selectively decreased pulmonary artery EC-SOD without altering total lung EC-SOD. PH and vascular remodeling induced by chronic hypoxia was augmented in SMC EC-SOD KO. Depletion of SMC EC-SOD did not impact content or activity of lung sGC or PDE5, though it blunted the hypoxia-induced increase in cGMP. Though total eNOS was not altered, active eNOS and GTPCH-1 decreased with hypoxia only in SMC EC-SOD KO. We conclude that the localized loss of pulmonary artery EC-SOD augments chronic hypoxic PH. In addition to oxidative inactivation of NO, deletion of EC-SOD seems to reduce eNOS activity, further compromising pulmonary vascular function.
    AJP Lung Cellular and Molecular Physiology 10/2014; 307(11). DOI:10.1152/ajplung.00096.2014 · 4.04 Impact Factor
  • Journal of Women's Health 10/2014; 23(10):863-863. · 1.90 Impact Factor
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    ABSTRACT: Genesis of myofibroblasts is obligatory for the development of pathology in many adult lung diseases. Adult lung tissue contains a population of perivascular ABCG2(pos) mesenchymal stem cells (MSC) that are precursors of myofibroblasts and distinct from NG2 pericytes. We hypothesized that these MSC participate in deleterious remodeling associated with pulmonary fibrosis (PF) and associated hypertension (PH). To test this hypothesis, resident lung MSC were quantified in lung samples from control subjects and PF patients. ABCG2(pos) cell numbers were decreased in human PF and interstitial lung disease compared to control samples. Genetic labeling of lung MSC in mice enabled determination of terminal lineage and localization of ABCG2 cells following intratracheal administration of bleomycin to elicit fibrotic lung injury. Fourteen days following bleomycin injury eGFP labeled lung MSC-derived cells were increased in number and localized to interstitial areas of fibrotic and microvessel remodeling. Finally, gene expression analysis was evaluated to define the response of MSC to bleomycin injury in vivo using ABCG2(pos) MSC isolated during the inflammatory phase post injury and in vitro bleomycin or TGFβ1 treated cells. MSC responded to bleomycin treatment in vivo with a pro-fibrotic gene program which was not recapitulated in vitro with bleomycin treatment. However, TGFβ1 treatment induced the appearance of a pro-fibrotic myofibroblast phenotype in vitro. Additionally, when exposed to the profibrotic stimulus, TGFβ1, ABCG2 and NG2 pericytes demonstrated distinct responses. Our data highlight ABCG2(pos) lung MSC as a novel cell population that contributes to detrimental myofibroblast-mediated remodeling during PF.
    AJP Cell Physiology 08/2014; 307(8). DOI:10.1152/ajpcell.00114.2014 · 3.67 Impact Factor
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    ABSTRACT: Understanding differences in gene expression that increase risk for pulmonary arterial hypertension (PAH) is essential to understanding the molecular basis for disease. Previous studies on patient samples were limited by either end-stage disease effects or by use of non-adherent cells which are not ideal to model vascular cells in vivo. These studies addressed the hypothesis that pathological processes associated with PAH may be identified via a genetic signature common across multiple cell types. Expression array experiments were initially conducted analyzing cell types at different stages of vascular differentiation (mesenchymal stromal and endothelial) derived from PAH patient specific induced pluripotent stem cells (iPS cells). Molecular pathways which were altered in the PAH cell lines were then compared to fibroblasts from 21 patients, including both idiopathic and heritable PAH. Wnt was identified as a target pathway and validated in vitro using primary patient mesenchymal and endothelial cells. Taken together, our data suggest that the molecular lesions that cause PAH are present in all cell types evaluated regardless of origin and that stimulation of the Wnt signaling pathway was a common molecular defect in both heritable and idiopathic PAH.
    AJP Cell Physiology 05/2014; 307(5). DOI:10.1152/ajpcell.00057.2014 · 3.67 Impact Factor
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    ABSTRACT: Analysis and isolation of adipocytes via flow cytometry is particularly useful to study their biology. However, the adoption of this technology has often been hampered by the presence of stromal/vascular cells in adipocyte fractions prepared from collagenase-digested adipose tissue. Here, we describe a multistep staining method and gating strategy that effectively excludes stromal contaminants. Initially, we set a gate optimized to the size and internal complexity of adipocytes. Exclusion of cell aggregates is then performed based on fluorescence of a nuclear stain followed by positive selection to collect only those cell events containing lipid droplets. Lastly, negative selection of cells expressing stromal or vascular lineage markers removes any remaining stromal contaminants. These procedures are applicable to simple analysis of adipocytes and their subcellular constituents by flow cytometry as well as isolation of adipocytes by flow sorting.
    Methods in enzymology 01/2014; 537C:281-296. DOI:10.1016/B978-0-12-411619-1.00015-X · 2.19 Impact Factor
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    ABSTRACT: Pulmonary arterial hypertension (PAH) is a vasculopathy characterized by enhanced pulmonary artery smooth muscle cell (PASMC) proliferation and suppressed apoptosis. This results in both increase in pulmonary arterial pressure and pulmonary vascular resistance. Recent studies have shown the implication of the signal transducer and activator of transcription 3 (STAT3)/bone morphogenetic protein receptor 2 (BMPR2)/peroxisome proliferator-activated receptor gamma (PPARγ) in PAH. STAT3 activation induces BMPR2 downregulation, decreasing PPARγ, which both contribute to the proproliferative and antiapoptotic phenotype seen in PAH. In chondrocytes, activation of this axis has been attributed to the advanced glycation end-products receptor (RAGE). As RAGE is one of the most upregulated proteins in PAH patients' lungs and a strong STAT3 activator, we hypothesized that by activating STAT3, RAGE induces BMPR2 and PPARγ downregulation, promoting PAH-PASMC proliferation and resistance to apoptosis. In vitro, using PASMCs isolated from PAH and healthy patients, we demonstrated that RAGE is overexpressed in PAH-PASMC (6-fold increase), thus inducing STAT3 activation (from 10% to 40% positive cells) and decrease in BMPR2 and PPARγ levels (>50% decrease). Pharmacological activation of RAGE in control cells by S100A4 recapitulates the PAH phenotype (increasing RAGE by 6-fold, thus activating STAT3 and decreasing BMPR2 and PPARγ). In both conditions, this phenotype is totally reversed on RAGE inhibition. In vivo, RAGE inhibition in monocrotaline- and Sugen-induced PAH demonstrates therapeutic effects characterized by PA pressure and right ventricular hypertrophy decrease (control rats have an mPAP around 15 mm Hg, PAH rats have an mPAP >40 mm Hg, and with RAGE inhibition, mPAP decreases to 20 and 28 mm Hg, respectively, in MCT and Sugen models). This was associated with significant improvement in lung perfusion and vascular remodeling due to decrease in proliferation (>50% decrease) and BMPR2/PPARγ axis restoration (increased by ≥60%). We have demonstrated the implications of RAGE in PAH etiology. Thus, RAGE constitutes a new attractive therapeutic target for PAH.
    Journal of the American Heart Association 12/2013; 2(1):e005157. DOI:10.1161/JAHA.112.005157 · 2.88 Impact Factor
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    ABSTRACT: Pulmonary vascular remodeling and oxidative stress are common to many adult lung diseases. However, little is known about the relevance of lung mesenchymal stem cells (MSCs) in these processes. We tested the hypothesis that dysfunctional lung MSCs directly participate in remodeling of the microcirculation. We employed a genetic model to deplete extracellular superoxide dismutase (EC-SOD) in lung MSCs coupled with lineage tracing analysis. We crossed (floxp)sod3 and mT/mG reporter mice to a strain expressing Cre recombinase under the control of the ABCG2 promoter. We demonstrated In vivo that depletion of EC-SOD in lung MSCs resulted in their contribution to microvascular remodeling in the smooth muscle actin positive layer. We further characterized lung MSCs to be multipotent vascular precursors, capable of myofibroblast, endothelial and pericyte differentiation in vitro. EC-SOD deficiency in cultured lung MSCs accelerated proliferation and apoptosis, restricted colony-forming ability, multilineage differentiation potential and promoted the transition to a contractile phenotype. Further studies correlated cell dysfunction to alterations in canonical Wnt/β-catenin signaling, which were more evident under conditions of oxidative stress. Our data establish that lung MSCs are a multipotent vascular precursor population, a population which has the capacity to participate in vascular remodeling and their function is likely regulated in part by the Wnt/β-catenin signaling pathway. These studies highlight an important role for microenviromental regulation of multipotent MSC function as well as their potential to contribute to tissue remodeling.
    03/2013; 3(1):31-49. DOI:10.4103/2045-8932.109912
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    Robert F Foronjy · Susan M Majka
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    ABSTRACT: Tissue resident mesenchymal stem cells (MSCs) are important regulators of tissue repair or regeneration, fibrosis, inflammation, angiogenesis and tumor formation. Bone marrow derived mesenchymal stem cells (BM-MSCs) and endothelial progenitor cells (EPC) are currently being considered and tested in clinical trials as a potential therapy in patients with such inflammatory lung diseases including, but not limited to, chronic lung disease, pulmonary arterial hypertension (PAH), pulmonary fibrosis (PF), chronic obstructive pulmonary disease (COPD)/emphysema and asthma. However, our current understanding of tissue resident lung MSCs remains limited. This review addresses how environmental cues impact on the phenotype and function of this endogenous stem cell pool. In addition, it examines how these local factors influence the efficacy of cell-based treatments for lung diseases.
    12/2012; 1(4):874. DOI:10.3390/cells1040874
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    ABSTRACT: We have reported the production of white adipocytes in adipose tissue from hematopoietic progenitors arising from bone marrow. However, technical challenges have hindered detection of this adipocyte population by certain other laboratories. These disparate results highlight the need for sensitive and definitive techniques to identify bone marrow progenitor (BMP)-derived adipocytes. In these studies we exploited new models and methods to enhance detection of this adipocyte population. Here we showed that confocal microscopy with spectrum acquisition could effectively identify green fluorescent protein (GFP) positive BMP-derived adipocytes by matching their fluorescence spectrum to that of native GFP. Likewise, imaging flow cytometry made it possible to visualize intact unilocular and multilocular GFP-positive BMP-derived adipocytes and distinguished them from non-fluorescent adipocytes and cell debris in the cytometer flow stream. We also devised a strategy to detect marker genes in flow-enriched adipocytes from which stromal cells were excluded. This technique also proved to be an efficient means for detecting genetically labeled adipocytes and should be applicable to models in which marker gene expression is low or absent. Finally, in vivo imaging of mice transplanted with BM from adipocyte-targeted luciferase donors showed a time-dependent increase in luciferase activity, with the bulk of luciferase activity confined to adipocytes rather than stromal cells. These results confirmed and extended our previous reports and provided proof-of-principle for sensitive techniques and models for detection and study of these unique cells.
    10/2012; 1(4):215-229. DOI:10.4161/adip.21496
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    ABSTRACT: Cell-free hemoglobin (Hb) exposure may be a pathogenic mediator in the development of pulmonary arterial hypertension (PAH), and when combined with chronic hypoxia the potential for exacerbation of PAH and vascular remodeling is likely more pronounced. We hypothesized that Hb may contribute to hypoxia-driven PAH collectively as a prooxidant, inflammatory, and nitric oxide (NO) scavenger. Using programmable micropump technology, we exposed male Sprague-Dawley rats housed under room air or hypoxia to 12 or 30 mg per day Hb for 3, 5, and 7 wk. Blood pressure, cardiac output, right ventricular hypertrophy, and indexes of pulmonary vascular remodeling were evaluated. Additionally, markers of oxidative stress, NO bioavailability and inflammation were determined. Hb increased pulmonary arterial (PA) pressure, pulmonary vessel wall stiffening, and right heart hypertrophy with temporal and dose dependence in both room air and hypoxic cohorts. Hb induced a modest increase in plasma oxidative stress markers (malondialdehyde and 4-hydroxynonenal), no change in NO bioavailability, and increased lung ICAM protein expression. Treatment with the antioxidant Tempol attenuated Hb-induced pulmonary arterial wall thickening, but not PA pressures or ICAM expression. Chronic exposure to low plasma Hb concentrations (range = 3-10 μM) lasting up to 7 wk in rodents induces pulmonary vascular disease via inflammation and to a lesser extent by Hb-mediated oxidation. Tempol demonstrated a modest effect on the attenuation of Hb-induced pulmonary vascular disease. NO bioavailability was found to be of minimal importance in this model.
    AJP Lung Cellular and Molecular Physiology 06/2012; 303(4):L312-26. DOI:10.1152/ajplung.00074.2012 · 4.04 Impact Factor
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    ABSTRACT: Obese white adipose tissue (AT) is characterized by large-scale infiltration of proinflammatory macrophages, in parallel with systemic insulin resistance; however, the cellular stimulus that initiates this signaling cascade and chemokine release is still unknown. The objective of this study was to determine the role of the phosphoinositide 3-kinase (PI3K) regulatory subunits on AT macrophage (ATM) infiltration in obesity. Here, we find that the Pik3r1 regulatory subunits (i.e., p85α/p55α/p50α) are highly induced in AT from high-fat diet-fed obese mice, concurrent with insulin resistance. Global heterozygous deletion of the Pik3r1 regulatory subunits (αHZ), but not knockout of Pik3r2 (p85β), preserves whole-body, AT, and skeletal muscle insulin sensitivity, despite severe obesity. Moreover, ATM accumulation, proinflammatory gene expression, and ex vivo chemokine secretion in obese αHZ mice are markedly reduced despite endoplasmic reticulum (ER) stress, hypoxia, adipocyte hypertrophy, and Jun NH(2)-terminal kinase activation. Furthermore, bone marrow transplant studies reveal that these improvements in obese αHZ mice are independent of reduced Pik3r1 expression in the hematopoietic compartment. Taken together, these studies demonstrate that Pik3r1 expression plays a critical role in mediating AT insulin sensitivity and, more so, suggest that reduced PI3K activity is a key step in the initiation and propagation of the inflammatory response in obese AT.
    Diabetes 06/2012; 61(10):2495-505. DOI:10.2337/db11-1433 · 8.47 Impact Factor
  • American Thoracic Society 2012 International Conference, May 18-23, 2012 • San Francisco, California; 05/2012
  • Mauricio Rojas · Naveen Gupta · Susan M. Majka
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    ABSTRACT: In the past decade, investigations related to the role of mesenchymal stem cells, both bone marrow derived and local, in lung disease and repair have grown exponentially. Stem cells are emerging as a therapeutic modality in various inflammatory disease states. A number of ongoing randomized phase I/II clinical trials are evaluating the effects of allogeneic mesenchymal stem cell (MSC) infusion in patients with multiple sclerosis, graft-versus-host disease, Crohn’s disease, and severe, chronic myocardial ischemia. MSC are also being considered and tested in clinical trials as a potential therapy in patients with inflammatory lung diseases including pulmonary fibrosis, acute lung injury, chronic obstructive pulmonary disease and emphysema. Several studies, including our own, have demonstrated compelling benefits from the administration of bone marrow derived MSC in animal models of lung injury. These studies are leading to growing interest in the therapeutic use of MSCs in lung diseases. In this chapter, we describe how the immunoregulatory effects of MSCs can confer substantial protection in the setting of the most common lung diseases such as fibrosis, acute lung injury, chronic obstructive pulmonary disease, asthma, and lung transplant. In addition we will discuss recent evidence for resident lung MSC and their functions during tissue homeostasis and disease.
    Stem Cells and Cancer Stem Cells, Volume 7, 01/2012: pages 145-154;
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    ABSTRACT: Human lung research has made remarkable progress over the last century largely through the use of animal models of disease. The challenge for the future is to translate these findings into human disease and bring about meaningful disease modification or even cure. The ability to generate transformative therapies in the future will require human tissue, currently scarce under the best of circumstances. Unfortunately, patient-derived somatic cells are often poorly characterized and have a limited life span in culture. Moreover, these cells are frequently obtained from patients with end-stage disease exposed to multiple drug therapies, leaving researchers with questions about whether their findings recapitulate disease-initiating processes or are simply the result of pharmacological intervention or subsequent host responses. The goal of studying early disease in multiple cell and tissue types has driven interest in the use of induced pluripotent stem cells (iPSCs) to model lung disease. These cells provide an alternative model for relevant lung research and hold promise in particular for studying the initiation of disease processes in genetic conditions such as heritable pulmonary arterial hypertension as well as other lung diseases. In this Perspective, we focus on potential iPSC use in pulmonary vascular disease research as a model for iPSC use in many types of advanced lung disease.
    AJP Lung Cellular and Molecular Physiology 12/2011; 301(6):L830-5. DOI:10.1152/ajplung.00255.2011 · 4.04 Impact Factor
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    ABSTRACT: During lung development, parabronchial SMC (PSMC) progenitors in the distal mesenchyme secrete fibroblast growth factor 10 (Fgf10), which acts on distal epithelial progenitors to promote their proliferation. β-catenin signaling within PSMC progenitors is essential for their maintenance, proliferation, and expression of Fgf10. Here, we report that this Wnt/Fgf10 embryonic signaling cascade is reactivated in mature PSMCs after naphthalene-induced injury to airway epithelium. Furthermore, we found that this paracrine Fgf10 action was essential for activating surviving variant Clara cells (the cells in the airway epithelium from which replacement epithelial cells originate) located at the bronchoalveolar duct junctions and adjacent to neuroendocrine bodies. After naphthalene injury, PSMCs secreted Fgf10 to activate Notch signaling and induce Snai1 expression in surviving variant Clara cells, which subsequently underwent a transient epithelial to mesenchymal transition to initiate the repair process. Epithelial Snai1 expression was important for regeneration after injury. We have therefore identified PSMCs as a stem cell niche for the variant Clara cells in the lung and established that paracrine Fgf10 signaling from the niche is critical for epithelial repair after naphthalene injury. These findings also have implications for understanding the misregulation of lung repair in asthma and cancer.
    The Journal of clinical investigation 11/2011; 121(11):4409-19. DOI:10.1172/JCI58097 · 13.77 Impact Factor
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    ABSTRACT: Tissue resident mesenchymal stem cells (MSC) are important regulators of tissue repair or regeneration, fibrosis, inflammation, angiogenesis and tumor formation. Taken together these studies suggest that resident lung MSC play a role during pulmonary tissue homeostasis, injury and repair during diseases such as pulmonary fibrosis (PF) and arterial hypertension (PAH). Here we describe a technology to define a population of resident lung MSC. The definition of this population in vivo pulmonary tissue using a define set of markers facilitates the repeated isolation of a well-characterized stem cell population by flow cytometry and the study of a specific cell type and function.
    Journal of Visualized Experiments 10/2011; DOI:10.3791/3159 · 1.33 Impact Factor
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    Susan M Majka · Yaacov Barak · Dwight J Klemm
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    ABSTRACT: Adipose tissue is the primary energy reservoir in the body and an important endocrine organ that plays roles in energy homeostasis, feeding, insulin sensitivity, and inflammation. While it was tacitly assumed that fat in different anatomical locations had a common origin and homogenous function, it is now clear that regional differences exist in adipose tissue characteristics and function. This is exemplified by the link between increased deep abdominal or visceral fat, but not peripheral adipose tissue and the metabolic disturbances associated with obesity. Regional differences in fat function are due in large part to distinct adipocyte populations that comprise the different fat depots. Evidence accrued primarily in the last decade indicates that the distinct adipocyte populations are generated by a number of processes during and after development. These include the production of adipocytes from different germ cell layers, the formation of distinct preadipocyte populations from mesenchymal progenitors of mesodermal origin, and the production of adipocytes from hematopoietic stem cells from the bone marrow. This review will examine each of these process and their relevance to normal adipose tissue formation and contribution to obesity-related diseases.
    Stem Cells 07/2011; 29(7):1034-40. DOI:10.1002/stem.653 · 7.70 Impact Factor
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    ABSTRACT: Pulmonary arterial hypertension (PAH) is thought to be driven by dysfunction of pulmonary vascular microendothelial cells (PMVEC). Most hereditary PAH is associated with BMPR2 mutations. However, the physiologic and molecular consequences of expression of BMPR2 mutations in PMVEC are unknown. In vivo experiments were performed on adult mice with conditional endothelial-specific expression of the truncation mutation Bmpr2delx4+, with age-matched transactivator-only mice as controls. Phenotype was assessed by RVSP, counts of muscularized vessels and proliferating cells, and staining for thromboses, inflammatory cells, and apoptotic cells. The effects of BMPR2 knockdown in PMVEC by siRNA on rates of apoptosis were assessed. Affymetrix expression arrays were performed on PMVEC isolated and cultured from triple transgenic mice carrying the immortomouse gene, a transactivator, and either control, Bmpr2delx4+ or Bmpr2R899X mutation. Transgenic mice showed increased RVSP and corresponding muscularization of small vessels, with histologic alterations including thrombosis, increased inflammatory cells, increased proliferating cells, and a moderate increase in apoptotic cells. Expression arrays showed alterations in specific pathways consistent with the histologic changes. Bmpr2delx4+ and Bmpr2R899X mutations resulted in very similar alterations in proliferation, apoptosis, metabolism, and adhesion; Bmpr2delx4+ cells showed upregulation of platelet adhesion genes and cytokines not seen in Bmpr2R899X PMVEC. Bmpr2 mutation in PMVEC does not cause a loss of differentiation markers as was seen with Bmpr2 mutation in smooth muscle cells. Bmpr2 mutation in PMVEC in vivo may drive PAH through multiple, potentially independent, downstream mechanisms, including proliferation, apoptosis, inflammation, and thrombosis.
    Respiratory research 06/2011; 12(1):84. DOI:10.1186/1465-9921-12-84 · 3.38 Impact Factor
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    ABSTRACT: Hypoxia-induced pulmonary arterial hypertension (PAH) is a deadly disease characterized by progressive remodeling and persistent vasoconstriction of the pulmonary arterial system. Remodeling of the pulmonary artery (PA) involves smooth muscle cell (SMC) proliferation, hypertrophy, migration, and elevated extracellular matrix (ECM) production elicited by mitogens and oxidants produced in response to hypoxic insult. We previously reported that the transcription factor cAMP response element binding protein (CREB) is depleted in medial PA SMCs in remodeled, hypertensive vessels in rats or calves exposed to chronic hypoxia. In culture, CREB loss can be induced in PA SMCs by exogenous oxidants or platelet-derived growth factor. Forced depletion of CREB with small interfering RNA (siRNA) in PA SMCs is sufficient to induce their proliferation, hypertrophy, migration, dedifferentiation, and ECM production. This suggests that oxidant and/or mitogen-induced loss of CREB in medial SMCs is, in part, responsible for PA thickening. Here, we tested whether oxidant scavengers could prevent the loss of CREB in PA SMCs and inhibit SMC proliferation, migration, and ECM production using in vitro and in vivo models. Exposure of PA SMCs to hypoxia induced hydrogen peroxide (H2O2) production and loss of CREB. Treatment of SMCs with exogenous H2O2 or a second oxidant, Sin-1, elicited CREB depletion under normoxic conditions. Exogenous H2O2 also induced SMC proliferation, migration, and increased elastin levels as did forced depletion of CREB. In vivo, hypoxia-induced thickening of the PA wall was suppressed by the superoxide dismutase mimetic, Tempol, which also prevented the loss of CREB in medial SMCs. Tempol also reduced hypoxia-induced SMC proliferation and elastin deposition in the PA. The data indicate that CREB levels in the arterial wall are regulated in part by oxidants produced in response to hypoxia and that CREB plays a crucial role in regulating SMC phenotype and PA remodeling.
    Journal of cardiovascular pharmacology 05/2011; 58(2):181-91. DOI:10.1097/FJC.0b013e31821f2773 · 2.11 Impact Factor
  • American Thoracic Society 2011 International Conference, May 13-18, 2011 • Denver Colorado; 05/2011

Publication Stats

3k Citations
244.86 Total Impact Points


  • 2012–2014
    • Vanderbilt University
      • Department of Medicine
      Нашвилл, Michigan, United States
  • 2011
    • Magee-Womens Hospital
      Pittsburgh, Pennsylvania, United States
  • 2007–2011
    • University of Colorado
      • • Cardiovascular Pulmonary Research Laboratory
      • • Department of Medicine
      Denver, Colorado, United States
  • 2006
    • Colorado State University
      • Department of Microbiology, Immunology & Pathology
      Fort Collins, Colorado, United States
  • 2002–2003
    • Baylor College of Medicine
      • • Department of Pediatrics
      • • Children's Nutrition Research Center
      Houston, TX, United States