Abstract 3594: Nogo-B is Essential for Macrophage Dependent Inflammatory Arteriogenesis and Angiogenesis

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Jun Yu ◽  
Carlos Fernandez-Hernando ◽  
Yajaira Suarez ◽  
Yajaira Suarez ◽  
Michael Schleicher ◽  
...  
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Blood Vessel ◽  
Plaque Rupture ◽  
Critical Role ◽  
Hindlimb Ischemia ◽  
Littermate Control ◽  
Regulated Gene Expression

Nogo-B, a member of the reticulon 4 family of proteins, is the dominant isoform expressed in endothelial, vascular smooth muscle and inflammatory cells. We previously have shown Nogo-B plays a critical role in vascular remodeling after injury in vivo . In mice and rabbits, neointimal expansion of injured blood vessels is associated with a marked reduction in Nogo-B, and, in humans, the loss of Nogo-B correlates with stenotic lesions and plaque rupture. However, the role of Nogo-B in regulating arteriogenesis or angiogenesis is not known. In the present study, we investigated the role of Nogo-B in arteriogenesis/angiogenesis using a mouse hindlimb ischemia model in Nogo-A/B KO (NgKO) and wild-type (WT) littermate control mice. Nogo-B mRNA and protein levels increased in the ischemic leg relative to the contralateral leg in WT. Hindlimb ischemia reduces tissue perfusion by 80% followed by a complete recovery of flow to pre-surgical values in WT after 4 weeks. In NgKO, there was a marked decrease in blood flow recovery post-ischemia, which was accompanied by a reduction in capillary density (assessed by isolectin staining), a decrease in smooth muscle/pericyte recruitment and an impaired collateral artery remodeling (assessed by quantitative angiography) compared to WT. Blood vessel formation and remodeling during ischemia requires coordination of the inflammatory response with regulated gene expression that promotes blood vessel assembly. Thus, we assessed the presence of tissue macrophages (F4/80 immunochemistry) 3 days after ischemia and found a 76% reduction of F4/80 positive cells in ischemic tissue in NgKO compared to WT. Mechanistically, the impaired recruitment of tissue macrophages was associated with reduced spreading, impairment of chemotaxis in response to monocyte chemokines compared to WT cells (76±4 vs. 113±8 cells/field in NgKO vs. WT), but not adhesion, of isolated bone marrow derived monocytes from NgKO compared to controls. Moreover, NgKO macrophage demonstrated impaired Rac activation, translocation and cytoskeletal organization upon stimulation of with chemokines. In conclusion, our data suggests that endogenous Nogo coordinates macrophage mediated inflammation with angiogenesis, arteriogenesis and blood flow control.

Heparan sulfate side chains have a critical role in the inhibitory effects of perlecan on vascular smooth muscle cell response to arterial injury

2014 ◽  
Vol 307 (3) ◽  
pp. H337-H345 ◽  
Author(s):  
Lara Gotha ◽  
Sang Yup Lim ◽  
Azriel B. Osherov ◽  
Rafael Wolff ◽  
Beiping Qiang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Critical Role ◽  
Arterial Injury ◽  
Side Chains ◽  
Wild Type ◽  
Injury Response ◽  
Migratory Response

Perlecan is a proteoglycan composed of a 470-kDa core protein linked to three heparan sulfate (HS) glycosaminoglycan chains. The intact proteoglycan inhibits the smooth muscle cell (SMC) response to vascular injury. Hspg2Δ3/Δ3 (MΔ3/Δ3) mice produce a mutant perlecan lacking the HS side chains. The objective of this study was to determine differences between these two types of perlecan in modifying SMC activities to the arterial injury response, in order to define the specific role of the HS side chains. In vitro proliferative and migratory activities were compared in SMC isolated from MΔ3/Δ3 and wild-type mice. Proliferation of MΔ3/Δ3 SMC was 1.5× greater than in wild type ( P < 0.001), increased by addition of growth factors, and showed a 42% greater migratory response than wild-type cells to PDGF-BB ( P < 0.001). In MΔ3/Δ3 SMC adhesion to fibronectin, and collagen types I and IV was significantly greater than wild type. Addition of DRL-12582, an inducer of perlecan expression, decreased proliferation and migratory response to PDGF-BB stimulation in wild-type SMC compared with MΔ3/Δ3. In an in vivo carotid artery wire injury model, the medial thickness, medial area/lumen ratio, and macrophage infiltration were significantly increased in the MΔ3/Δ3 mice, indicating a prominent role of the HS side chain in limiting vascular injury response. Mutant perlecan that lacks HS side chains had a marked reduction in the inhibition of in vitro SMC function and the in vivo arterial response to injury, indicating the critical role of HS side chains in perlecan function in the vessel wall.

Abstract 3598: Critical Role of Th17-CD4 + T cells in Angiogenic Response to Hindlimb Ischemia in Mice

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Takeki Hata ◽  
Masafumi Takahashi ◽  
Masanori Kawaguchi ◽  
Yuichiro Kashima ◽  
Yuji Shiba ◽  
...  
Keyword(s):  
T Cells ◽  
Blood Flow ◽  
Th17 Cells ◽  
Critical Role ◽  
Interleukin 17 ◽  
Hindlimb Ischemia ◽  
Capillary Formation ◽  
Angiogenic Response ◽  
Flow Perfusion

Background: Accumulating evidence indicates that CD4 + T cells contribute to the development of collateral vesssels in ischemic tissue; however, little is known about the responsible subset of CD4 + T cells in the induction of angiogenesis. Th17 cells are recently identified as a new subset of CD4 + T cells and have been associated with the pathogenesis of certain autoimmune diseases. Th17 cells specifically secrete interleukin-17 (IL-17) and regulate various biological functions. The purpose of this study is to investigate the role of CD4 + T and Th17 cells in angiogenic response to hindlimb ischemia. Methods and Results: Unilateral hindlimb ischemia was produced in wild-type (WT: C57BL/6, 8- to 10-week-old) mice treated with or without a neutralizing antibody against CD4. Blood flow perfusion and capillary formation were assessed by using a laser Doppler perfusion imaging (LDPI) and CD31 immunostaining, respectively. Well-developed collateral vessels and capillary formation were observed in WT mice in response to hindlimb ischemia. Treatment with a neutralizing anti-CD4 antibody resulted in almost complete CD4 + T cell depletion (flow cytometry analysis, control: 45.4% vs. antibody: 1.0%) and a significant decrease in angiogenesis after the induction of hindlimb ischemia (LDPI, 21 days, control: 0.61 ± 0.1 vs. antibody: 0.41 ± 0.1, p<0.05). IL-17-deficient (IL-17 −/− ) mice also showed a significant reduction of blood flow perfusion, compared with WT mice (LDPI, day 14: 0.56 ± 0.3 vs. 0.31 ± 0.2, p<0.05; day 21: 0.66 ± 0.3 vs. 0.37 ± 0.3, p=0.05). IL-17 −/− mice had severe ischemic damage of the limb and resulted in a 25% incidence of autoamputation by day 21 (no limb loss in WT mice). Furthermore, capillary formation was also decreased significantly in IL-17 −/− mice (692.9 ± 165.6/mm 2 vs. 1223.3 ± 267.3/mm 2 , p<0.01). Conclusion : These findings demonstrate that Th17 cells, a new subset of CD4 + T cells, contribute to the angiogenic response to hindlimb ischemia and provide new insights into the mechanism by which T cells promote collateral development and angiogenesis.

scholarly journals Role of astrocytes in cerebrovascular regulation

2006 ◽  
Vol 100 (1) ◽  
pp. 307-317 ◽  
Author(s):  
Raymond C. Koehler ◽  
Debebe Gebremedhin ◽  
David R. Harder
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Neurovascular Unit ◽  
Brain Slices ◽  
Calcium Oscillations ◽  
Synaptic Activity

Astrocytes send processes to synapses and blood vessels, communicate with other astrocytes through gap junctions and by release of ATP, and thus are an integral component of the neurovascular unit. Electrical field stimulations in brain slices demonstrate an increase in intracellular calcium in astrocyte cell bodies transmitted to perivascular end-feet, followed by a decrease in vascular smooth muscle calcium oscillations and arteriolar dilation. The increase in astrocyte calcium after neuronal activation is mediated, in part, by activation of metabotropic glutamate receptors. Calcium signaling in vitro can also be influenced by adenosine acting on A2B receptors and by epoxyeicosatrienoic acids (EETs) shown to be synthesized in astrocytes. Prostaglandins, EETs, arachidonic acid, and potassium ions are candidate mediators of communication between astrocyte end-feet and vascular smooth muscle. In vivo evidence supports a role for cyclooxygenase-2 metabolites, EETs, adenosine, and neuronally derived nitric oxide in the coupling of increased blood flow to increased neuronal activity. Combined inhibition of the EETs, nitric oxide, and adenosine pathways indicates that signaling is not by parallel, independent pathways. Indirect pharmacological results are consistent with astrocytes acting as intermediaries in neurovascular signaling within the neurovascular unit. For specific stimuli, astrocytes are also capable of transmitting signals to pial arterioles on the brain surface for ensuring adequate inflow pressure to parenchymal feeding arterioles. Therefore, evidence from brain slices and indirect evidence in vivo with pharmacological approaches suggest that astrocytes play a pivotal role in regulating the fundamental physiological response coupling dynamic changes in cerebral blood flow to neuronal synaptic activity. Future work using in vivo imaging and genetic manipulation will be required to provide more direct evidence for a role of astrocytes in neurovascular coupling.

scholarly journals Redundant Role of Tissue-Selective TAFII105 in B Lymphocytes

2002 ◽  
Vol 22 (18) ◽  
pp. 6564-6572 ◽  
Author(s):  
Richard N. Freiman ◽  
Shane R. Albright ◽  
Leslie E. Chu ◽  
Shuang Zheng ◽  
Hong-Erh Liang ◽  
...  
Keyword(s):  
B Cells ◽  
Rna Polymerase Ii ◽  
B Lymphocyte ◽  
Critical Role ◽  
Central Component ◽  
Related Factors ◽  
Tissue Specific ◽  
Regulated Gene Expression

ABSTRACT Regulated gene expression is a complex process achieved through the function of multiple protein factors acting in concert at a given promoter. The transcription factor TFIID is a central component of the machinery regulating mRNA synthesis by RNA polymerase II. This large multiprotein complex is composed of the TATA box binding protein (TBP) and several TBP-associated factors (TAFIIs). The recent discovery of multiple TBP-related factors and tissue-specific TAFIIs suggests the existence of specialized TFIID complexes that likely play a critical role in regulating transcription in a gene- and tissue-specific manner. The tissue-selective factor TAFII105 was originally identified as a component of TFIID derived from a human B-cell line. In this report we demonstrate the specific induction of TAFII105 in cultured B cells in response to bacterial lipopolysaccharide (LPS). To examine the in vivo role of TAFII105, we have generated TAFII105-null mice by homologous recombination. Here we show that B-lymphocyte development is largely unaffected by the absence of TAFII105. TAFII105-null B cells can proliferate in response to LPS, produce relatively normal levels of resting antibodies, and can mount an immune response by producing antigen-specific antibodies in response to immunization. Taken together, we conclude that the function of TAFII105 in B cells is likely redundant with the function of other TAFII105-related cellular proteins.

Abstract MP151: Cardiomyocyte HIPK2 is a Critical Regulator of Purinergic Signaling Regulated Myocardial Inflammation

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Tousif Sultan ◽  
Anand P Singh ◽  
Prachi Umbarkar ◽  
QinKun Zhang ◽  
Hind Lal
Keyword(s):  
Cardiac Function ◽  
Purinergic Signaling ◽  
Critical Role ◽  
Public Health Problem ◽  
Neonatal Rat ◽  
Myocardial Inflammation ◽  
Littermate Control

Objective: Heart failure (HF) is a major and growing public health problem worldwide. Recently our lab has identified HIPK2 as an essential kinase to maintain basal cardiac function. However, the role of cardiomyocytes specific HIPK2 (CM-HIPK2) in myocardial inflammation is unknown. Methods: α-MHC promoter-driven, Cre mice were crossed with HIPK2 fl/fl mice to generate CM-HIPK2 KO. Echocardiography was performed to assess cardiac function. Immunoblotting assays were performed to determine the expression of HIPK2, CD39, CD73, and other signaling pathway . Flow cytometry and ELISA were performed to study the dynamics of inflammation. Results: Consistent with our previous report , echocardiography confirmed an impaired cardiac function in 3 months old CM-HIPK2 KO as compared to their littermate controls. Importantly, cardiac function in the KOs starts to deteriorate at ~2.5 months of age, thus, at two months of age, the cardiac function of KO and littermate control was comparable. Comprehensive immune profiling of CM-HIPK2 KO and littermate control hearts were performed at two months of age. We observed an increased frequency of infiltrated CD45 + leukocytes, CCR2 + pro-inflammatory macrophages, Th17 + , Th9 + , CD45 + TNFα + , CD45 + IL1β + , CD45 + Ki67 + cells but diminished frequency of Myeloid-derived suppressor cells (MDSCs), TCRαβ + CTLA-4 + and TCRαβ + PD-1 + in the CM-HIPK2 KO hearts. Mechanistically, we observed a significantly reduced expression of CD39 and CD73 over HIPK2 deleted cardiomyocytes. Indeed, CD39 and CD73 are the key players of purinergic signaling regulated inflammation response. In-vitro studies with neonatal rat ventricular cardiomyocytes (NRVMs) corroborated the in-vivo findings. Specifically, adenovirus-mediated overexpression of HIPK2 significantly increased CD39 expression. Consistently, Ad-shRNA-HIPK2 expression suppressed the CD39 expression. Taken together, our findings suggest a critical role of CM-HIPK2 in purinergic signaling mediated myocardial inflammation. Conclusions: CM-HIPK2 maintains basal cardiac function by controlling purinergic signaling regulated myocardial inflammation. Future work will explore the underlying mechanism of HIPK2 mediated regulation of CD39 and CD73.

Abstract W P365: Critical Role of Smooth Muscle Cell Phenotypic Modulation in Cerebral Aneurysm Formation and Rupture

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Robert M Starke ◽  
Muhammad S Ali ◽  
Nohra Chalouhi ◽  
Pascal M Jabbour ◽  
Stavropoula I Tjoumakaris ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Carotid Arteries ◽  
Critical Role ◽  
Phenotypic Modulation ◽  
Knock Out ◽  
Aneurysm Formation ◽  
Tnf Α ◽  
Knock Out Mice

Objective: Little is known about smooth muscle cell (SMC) phenotypic modulation in the cerebral circulation or pathogenesis of intracranial aneurysms. TNF-α has been associated with aneurysms, but a direct role has not been established. Methods: Cultured cerebral SMC were treated with TNF-α for PCR, western blot, chromatin immune-precipitation (CHIP), and adenovirus promoter transfection. In vivo experiments were carried out in the following models: application of TNF-α to the surface of carotid arteries, cerebral model of hypertension and hemodynamic stress, and cerebral model of aneurysm formation and rupture. The TNF-α inhibitor 3,6’dithiothalidomide (DTH) was synthesized. Results: Cultured cerebral SMC over-expressing myocardin induced expression of key SMC contractile genes (SM-α-actin, SM-22α, SM-MHC), while dominant negative suppressed expression. TNF-α treatment inhibited this contractile phenotype and induced pro-inflammatory genes (MCP-1, MMPs, VCAM-1, IL-1β). TNF-α increased expression of KLF4 and KLF4 siRNA abrogated TNF-α induced phentotypic modulation. These mechanisms were confirmed in vivo following exposure of rat carotid arteries to TNF-α and early in a model of cerebral hypertension and hemodynamic stress prior to cerebral aneurysm formation. Treatment with DTH reversed these pathological vessel wall alterations. TNF-α knock-out mice and DTH pre-treatment decreased the incidence of aneurysm formation and rupture. As compared with sham mice, TNF-α expression was not significantly different in TNF-α knock-out mice or those pre-treated with DTH, but was elevated in unruptured and ruptured aneurysms. Initiation of DTH 7 days after aneurysm induction did not alter aneurysm incidence, but resulted in stabilization and decreased rupture. CHIP assays in vivo and in vitro demonstrated that TNF-α promotes epigenetic changes through KLF4 dependent alterations in promoter regions of myocardin, SMC’s, and inflammatory genes. Conclusion: TNF-α induces phenotypic modulation of cerebral SMC through myocardin and KLF4 regulated pathways. These results demonstrate a novel role for TNF-α in promoting a pro-inflammatory phenotype. These data suggests a critical role of TNF-α in the formation and rupture of aneurysms.

Adrenomedullin insufficiency increases allergen-induced airway hyperresponsiveness in mice

2007 ◽  
Vol 102 (6) ◽  
pp. 2361-2368 ◽  
Author(s):  
Hiroshi Yamamoto ◽  
Takahide Nagase ◽  
Takayuki Shindo ◽  
Shinji Teramoto ◽  
Tomoko Aoki-Nagase ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Airway Responsiveness ◽  
Mutant Mice ◽  
Wild Type ◽  
T Helper 1 ◽  
Littermate Control

Adrenomedullin (ADM), a newly identified vasodilating peptide, is reported to be expressed in lungs and have a bronchodilating effect. We hypothesized whether ADM could be involved in the pathogenesis of bronchial asthma. We examined the role of ADM in airway responsiveness using heterozygous ADM-deficient mice ( AM+/−) and their littermate control ( AM+/+). Here, we show that airway responsiveness is enhanced in ADM mutant mice after sensitization and challenge with ovalbumin (OVA). The immunoreactive ADM level in the lung tissue after methacholine challenge was significantly greater in the wild-type mice than that in the mutant. However, the impairment of ADM gene function did not affect immunoglobulins (OVA-specific IgE and IgG1), T helper 1 and 2 cytokines, and leukotrenes. Thus the conventional mechanism of allergen-induced airway responsiveness is not relevant to this model. Furthermore, morphometric analysis revealed that eosinophilia and airway hypersecretion were similarly found in both the OVA-treated ADM mutant mice and the OVA-treated wild-type mice. On the other hand, the area of the airway smooth muscle layer of the OVA-treated mutant mice was significantly greater than that of the OVA-treated wild-type mice. These results suggest that ADM gene disruption may be associated with airway smooth muscle hyperplasia as well as enhanced airway hyperresponsiveness. ADM mutant mice might provide novel insights to study the pathophysiological role of ADM in vivo.

scholarly journals Nr4a1 siRNA Expression Attenuates α-MSH Regulated Gene Expression in 3T3-L1 Adipocytes

2011 ◽  
Vol 25 (2) ◽  
pp. 291-306 ◽  
Author(s):  
S.-C. Mary Wang ◽  
Stephen A. Myers ◽  
Natalie A. Eriksson ◽  
Rebecca L. Fitzsimmons ◽  
George E. O. Muscat
Keyword(s):  
Gene Expression ◽  
Mrna Expression ◽  
Cross Talk ◽  
Energy Homeostasis ◽  
Critical Role ◽  
Nuclear Hormone Receptor ◽  
Sirna Expression ◽  
Regulated Gene Expression

Abstract Several recent investigations have underscored the growing role of melanocortin signaling in the peripheral regulation of lipid, glucose, and energy homeostasis. In addition, the melanocortins play a critical role in the central control of satiety. These observations, and the latest reports highlighting the emerging role of the nuclear hormone receptor (NR) 4A subgroup in metabolism, have prompted us to investigate the cross talk between [Nle4, d-Phe7] (NDP)-α-MSH and Nr4a signaling in adipose. We have shown that NDP-MSH strikingly and preferentially induces the expression of the NR4A subgroup (but not any other members of the NR superfamily) in differentiated 3T3-L1 adipocytes. Utilization of quantitative PCR on custom-designed metabolic TaqMan low-density arrays identified the concomitant and marked induction of the mRNAs encoding Il-6, Cox2, Pdk4, and Pck-1 after NDP-MSH treatment. Similar experiments demonstrated that the mRNA expression profile induced by cAMP and NDP-MSH treatment displayed unique but also overlapping properties and suggested that melanocortin-mediated induction of gene expression involves cAMP-dependent and -independent signaling. Nr4a1/Nur77 small interfering RNA (siRNA) expression suppressed NDP-MSH-mediated induction of Nr4a1/Nur77 and Nr4a3/Nor-1 (but not Nr4a2/Nurr1). Moreover, expression of the siRNA-attenuated NDP-MSH mediated induction of the mRNAs encoding Il-6, Cox2/Ptgs2, and Pck-1 expression. In addition, Nur77 siRNA expression attenuated NDP-MSH-mediated glucose uptake. In vivo, ip administration of NDP-MSH to C57 BL/6J (male) mice significantly induced the expression of the mRNA encoding Nur77 and increased IL-6, Cox2, Pck1, and Pdk4 mRNA expression in (inguinal) adipose tissue. We conclude that Nur77 expression is necessary for MSH-mediated induction of gene expression in differentiated adipocytes. Furthermore, this study demonstrates cross talk between MSH and Nr4a signaling in adipocytes.

scholarly journals The role of the PZP domain of AF10 in acute leukemia driven by AF10 translocations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Anagha Deshpande ◽  
Khan L. Cox ◽  
Fan Xuan ◽  
Mohamad Zandian ◽  
...  
Keyword(s):  
Critical Role ◽  
Cellular Transformation ◽  
Acute Leukemias ◽  
Hematopoietic Stem ◽  
Nucleosome Core ◽  
Stem And Progenitor Cells ◽  
Transforming Activity

AbstractChromosomal translocations of the AF10 (or MLLT10) gene are frequently found in acute leukemias. Here, we show that the PZP domain of AF10 (AF10PZP), which is consistently impaired or deleted in leukemogenic AF10 translocations, plays a critical role in blocking malignant transformation. Incorporation of functional AF10PZP into the leukemogenic CALM-AF10 fusion prevents the transforming activity of the fusion in bone marrow-derived hematopoietic stem and progenitor cells in vitro and in vivo and abrogates CALM-AF10-mediated leukemogenesis in vivo. Crystallographic, biochemical and mutagenesis studies reveal that AF10PZP binds to the nucleosome core particle through multivalent contacts with the histone H3 tail and DNA and associates with chromatin in cells, colocalizing with active methylation marks and discriminating against the repressive H3K27me3 mark. AF10PZP promotes nuclear localization of CALM-AF10 and is required for association with chromatin. Our data indicate that the disruption of AF10PZP function in the CALM-AF10 fusion directly leads to transformation, whereas the inclusion of AF10PZP downregulates Hoxa genes and reverses cellular transformation. Our findings highlight the molecular mechanism by which AF10 targets chromatin and suggest a model for the AF10PZP-dependent CALM-AF10-mediated leukemogenesis.

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