ABSTRACT
INTRODUCTION: Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an adipokine. It has been reported that decreased serum vaspin levels are significantly associated with stroke severity and prognosis. OBJECTIVE: This article aims to explore the theoretical feasibility of vaspin supplementation for cerebral ischemia-reperfusion (I/R) injury. METHODS: The I/R mouse models were constructed by the middle cerebral artery occlusion (MCAO) method, and the effects of vaspin on cerebral infarction, neurological function, angiogenesis and endoplasmic reticulum (ER) stress were explored. To verify the mediation of ER stress in the regulation of vaspin, human brain microvascular endothelial cells (HBMECs) were subjected to ER stress agonist tunicamycin in vitro. The impacts of vaspin and tunicamycin on oxygen glucose deprivation/ recovery (OGD/R)-induced cell viability, apoptosis, and angiogenesis were examined. RESULTS: Vaspin inhibited blood-brain barrier breakdown and infarction occurred in the brain tissue of the I/R mice. Vaspin also enhanced cerebral neovascularization and reduced the apoptosis. Additional tunicamycin increased the apoptosis of HBMECs and inhibited angiogenesis, reversing the protective effect of vaspin on cells. CONCLUSION: Together, this study reveals that vaspin supplementation reduces cerebral infarction and works against neurological dysfunction. It maintains the survival and angiogenesis capacity of HBMECs by inhibiting ER stress.
Subject(s)
Adipokines , Angiogenesis , Brain Ischemia , Endoplasmic Reticulum Stress , Reperfusion Injury , Serpins , Animals , Humans , Male , Mice , Adipokines/administration & dosage , Adipokines/metabolism , Adipokines/pharmacology , Angiogenesis/drug effects , Angiogenesis/metabolism , Apoptosis/drug effects , Brain Ischemia/drug therapy , Brain Ischemia/metabolism , Disease Models, Animal , Endoplasmic Reticulum Stress/drug effects , Endothelial Cells/metabolism , Endothelial Cells/drug effects , Infarction, Middle Cerebral Artery/metabolism , Infarction, Middle Cerebral Artery/prevention & control , Neovascularization, Physiologic/drug effects , Reperfusion Injury/metabolism , Reperfusion Injury/prevention & control , Serpins/metabolism , Serpins/pharmacologyABSTRACT
The effects of adipokine administration to the hypothalamic preoptic area (POA), which is one of the body temperature (BT) regulation centers in the central nervous system, on BT were investigated in male Wistar rats. BT was measured in conscious rats using telemetry. Insulin-like growth factor-1 (IGF-1), interleukin-1ß (IL-1ß), monocyte chemoattractant protein-1 and lipocalin-2 produced hyperthermia, and the effects induced by IL-1ß (25 ng) and IGF-1 (5 µg) were sustainable and remarkable. IL-6 did not show any significant effect. The IGF-1-induced effect was inhibited by pretreatment with IGF binding protein 3 (IGFBP3) or NVP-AEW541 (NVP, a selective inhibitor of type 1 IGF receptor tyrosine kinase, IGF1R TK). NVP-induced inhibition was observed only in the early phase of IGF-1-induced hyperthermia. In addition, IGF-1 increased the IL-1ß concentration in the microdialysate of POA perfusion, but did not increase the IL-1ß concentration in the plasma or the PGE2 concentration in the microdialysate. These findings suggested that IGF-1 produced hyperthermia, which was mediated, at least a part, through an increased IL-1ß concentration after activation of IGF1R TK in the POA, and the IGF-IGFBP system possibly participates in BT homeostasis in the POA.
Subject(s)
Adipokines/administration & dosage , Adipokines/pharmacology , Body Temperature/drug effects , Body Temperature/genetics , Preoptic Area/metabolism , Preoptic Area/physiology , Animals , Chemokine CCL2/administration & dosage , Chemokine CCL2/pharmacology , Fever/chemically induced , Fever/genetics , Insulin-Like Growth Factor I/administration & dosage , Insulin-Like Growth Factor I/pharmacology , Interleukin-1beta/administration & dosage , Interleukin-1beta/metabolism , Interleukin-1beta/pharmacology , Lipocalin-2/administration & dosage , Lipocalin-2/pharmacology , Male , Protein-Tyrosine Kinases/metabolism , Rats, Wistar , Receptor, IGF Type 1/metabolismABSTRACT
BACKGROUND: obesity is a chronic disease associated with inadequate eating habits and reduced levels of physical activity. Because of obesity, the risk for comorbidities is increased, especially for cardiovascular diseases, insulin resistance, and increased pro-inflammatory factors. The aim of the present investigation was to analyze potential correlations between pro/anti-inflammatory adipokines, glycemic index, and other markers of diet quality using a metabolic profile in women undergoing interdisciplinary weight loss therapy. METHODS: thirty-two women with obesity were enrolled in a 12-week program of interdisciplinary therapy combining a clinical, nutritional, and physical exercise approach. Body composition, quality of diet, metabolic profile, and pro/anti-inflammatory adipokines were analyzed. RESULTS: the therapy showed to be effective in reducing body weight (from 93.16 ± 16.96 to 88.36 ± 16.23; p = 0.0000001), body mass index (from 34.01 ± 4.00 to 32.29 ± 3.96; p = 0.0000001), and body fat (from 38.25 ± 5.05 to 36.13 ± 5; p = 0.0000001). There was also an improvement in lipid profile, including total cholesterol (from 196.16 ± 34.78 to 183.53 ± 43.15; p = 0.001), non-HDL-cholesterol (from 142 ± 30.05 to 1333.69 ± 35.41; p = 0.01), VLDL-cholesterol (from 27.13 ± 12.4 to 22.06 ± 8.55; p = 0.002), triglycerides (from 135.88 ± 61.21 to 110.75 ± 43.09; p = 0.002) and glucose metabolism, including glucose (from 97.13 ± 10.43 to 92.6 ± 6.6; p = 0.004), and insulin (from 13.05 ± 5.54 to 11.29 ± 4.85; p = 0.03). As for food intake, there was a decrease in calorie consumption (from 1991.45 ± 677.78 to 1468.88 ± 390.56; p = 0.002), carbohydrates (from 50.37 ± 6 to 47.04 ± 8.67; p = 0.04), lipids (from 31.83 ± 5.53 to 30.37 ± 7.04; p = 0.3), and glycemic load (from 80.53 ± 39.88 to 54.79 ± 23.69; p = 0.02), and an increased consumption of proteins (from 18.3 ± 2.39 to 22.89 ± 4.9; p = 0.002). Positive correlations were demonstrated between insulin concentration and waist circumference (r = 0.82; p = 0.003); leptin and body fat and abdominal circumference (r = 0.74; p = 0.01); and LDL-cholesterol fraction and total cholesterol consumption (r = 0.69; p = 0.027). Negative correlations were demonstrated between leptin and monosaturated fat consumption (r = -0.71; p = 0.02); and adiponectin and liver enzyme GGT levels (r = -0.65; p = 0.04). CONCLUSIONS: interdisciplinary therapy had positive effects on inflammatory state, mediated by leptin, adiponectin, and quality of diet. Our findings suggest the effectiveness and clinical relevance of the interdisciplinary clinical therapy applied for obesity
INTRODUCCIÓN: la obesidad es una enfermedad crónica asociada con hábitos alimentarios inadecuados y niveles reducidos de actividad física. Debido a la obesidad, el riesgo de comorbilidad aumenta, especialmente el de las enfermedades cardiovasculares, la resistencia a la insulina y el aumento de los factores proinflamatorios. El objetivo de la presente investigación fue analizar las posibles correlaciones entre las adipocinas pro/antiinflamatorias, el índice glucémico y otros marcadores de calidad de la dieta con el perfil metabólico en mujeres sometidas a terapia interdisciplinaria para perder peso. MÉTODOS: treinta y dos mujeres con obesidad participaron en 12 semanas de terapia interdisciplinaria en la que se combinaron los enfoques clínico, nutricional y de ejercicio físico. Se analizaron la composición corporal, la calidad de la dieta, el perfil metabólico y las adipocinas pro/antiinflamatorias. RESULTADOS: la terapia demostró ser efectiva para reducir el peso corporal (de 93,16 ± 16,96 a 88,36 ± 16,23; p = 0,0000001), el índice de masa corporal (de 34,01 ± 4,00 a 32,29 ± 3,96; p = 0,0000001) y la grasa corporal (de 38,25 ± 5,05 a 36,13 ± 5,00; p = 0,0000001). También hubo una mejora del perfil lipídico, incluidos el colesterol total (de 196,16 ± 34,78 a 183,53 ± 43,15; p = 0,001), el colesterol no HDL (de 142,00 ± 30,05 a 1333,69 ± 35,41; p = 0,01), el VLDL-colesterol (de 27,13 ± 12,4 a 22,06 ± 8,55; p = 0,002), y el metabolismo de la glucosa, incluyendo la glucosa (de 97,13 ± 10,43 a 92,6 ± 6,6; p = 0,004) y la insulina (de 13,05 ± 5,54 a 11,29 ± 4,85; p = 0,03). En cuanto a la ingesta de alimentos, hubo disminución en el consumo de calorías (de 1991,45 ± 677,78 a 1468,88 ± 390,56; p = 0,002), carbohidratos (de 50,37 ± 6,00 a 47,04 ± 8,67; p = 0,04), lípidos (de 31,83 ± 5,53 a 30,37 ± 7,04; p = 0,3) y carga glucémica (de 80,53 ± 39,88 a 54,79 ± 23,69; p = 0,02), y aumento del consumo de proteínas (de 18,3 ± 2,39 a 22,89 ± 4,90; p = 0,002). Se demostraron correlaciones positivas entre la concentración de insulina y la circunferencia de la cintura (r = 0,82; p = 0,003); la leptina, la grasa corporal y la circunferencia abdominal (r = 0,74; p = 0,01), y la fracción de colesterol LDL y el consumo total de colesterol (r = 0,69; p = 0,027). Se demostraron correlaciones negativas entre la leptina y el consumo de grasa monosaturada (r = -0,71; p = 0,02), y la adiponectina y la enzima hepática GGT (r = -0,65; p = 0,04). CONCLUSIONES: la terapia interdisciplinaria tuvo efectos positivos sobre el estado inflamatorio, mediado por la leptina, la adiponectina, y la calidad de la dieta. Nuestros hallazgos sugieren la efectividad y la relevancia clínica de la terapia clínica interdisciplinaria aplicada a la obesidad
Subject(s)
Humans , Female , Adult , Inflammation/drug therapy , Leptin/administration & dosage , Adiponectin/administration & dosage , Obesity/diet therapy , Adipokines/administration & dosage , Patient Care Team , Feeding Behavior , Cardiovascular Diseases/prevention & control , Body Weight , Body Mass Index , Body Composition/physiologyABSTRACT
C1q/tumor necrosis factor (TNF)-related proteins (CTRPs) have been confirmed to be adiponectin (APN) paralogs and some share APN's metabolic regulatory functions. Oxidative stress contributes to brain injury after intracerebral hemorrhage (ICH) and APN can inhibit oxidative stress injury during ICH. Thus, we addressed the role of a specific CTRP-CTRP 3-after experimental ICH and studied post-ICH oxidative stress injury and the pathway involved. ICH was induced in rats via intracerebral infusion of autologous blood, and the effects of exogenous CTRP3 (lentivirus or recombinant CTRP3) replenishment on ICH injury were investigated. Rats received an intracerebral injection of H89 (a PKA inhibitor) with recombinant CTRP3 (rCTRP 3) or dibutyryl cyclic AMP (db-cAMP, a PKA activator) without rCTRP 3. Then, oxidative stress, CTRP 3, PKA, and NADPH oxidase-2 (NOX 2) were assessed, as were functional outcomes, cerebral edema, and blood-brain barrier (BBB) permeability at 24h. We found that treatment with recombinant or lentivirus CTRP3 reduced cerebral edema and BBB damage and improved neurological functions as well as reduced post-ICH elevated reactive oxygen species and malondialdehyde and increased reduced glutathione and the ratio of oxidized to reduced glutathione. CTRP 3 applied 30min after ICH increased PKA, reduced NOX 2 expression, and decreased oxidative stress. A PKA-inhibitor abolished CTRP 3-induced protective effects and increased NOX 2 expression. We conclude from our results that CTRP 3 may regulate oxidative stress injury via PKA signaling and may provide a new therapeutic strategy for ICH.
Subject(s)
Adipokines/metabolism , Brain/metabolism , Cerebral Hemorrhage/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Oxidative Stress/physiology , Adipokines/administration & dosage , Adipokines/genetics , Animals , Antioxidants/administration & dosage , Antioxidants/metabolism , Brain/drug effects , Brain Edema/metabolism , Brain Edema/therapy , Cerebral Hemorrhage/therapy , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , Disease Models, Animal , Genetic Therapy , Genetic Vectors , Lentivirus/genetics , Male , Membrane Glycoproteins/metabolism , NADPH Oxidase 2 , NADPH Oxidases/metabolism , Neuroprotection/drug effects , Neuroprotection/physiology , Oxidative Stress/drug effects , RNA, Messenger/metabolism , Random Allocation , Rats, Sprague-Dawley , Recombinant Proteins/administration & dosage , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Signal Transduction/drug effects , Signal Transduction/physiologyABSTRACT
Macrophages are an important source of pro-inflammatory and pro-angiogenic factors, which can promote pathological processes involving inflammation and angiogenesis. This study investigated the effects of Apelin on macrophages under both normal and hypoxic conditions. Under normal culture conditions, Apelin down-regulated the mRNA expression levels of monocyte chemotactic protein 1 (MCP1), monocyte chemotactic protein 3 (MCP3), macrophage inflammatory protein 1 (MIP1α, MIP1ß), vascular endothelial growth factor A (VEGFA), Angiopoietin 2 (Ang2) and tumor necrosis factor α (TNFα). The supernatant concentrations of MCP1, MCP3, MIP1α, MIP1ß, macrophage inflammatory protein 2 (MIP2) and TNFα proteins were significantly decreased in the Apelin treated group. Hypoxia induced profound up-regulations of the angiogenic, chemokine, and inflammatory factors at both the mRNA and protein levels. Apelin suppressed the hypoxia-induced increases in MCP1, MCP3, MIP2, MIP1ß and TNFα expression. The underlying mechanism of Apelin inhibit inflammation is regulating NF-κB/JNK signal pathway. Additionally, Apelin can protect macrophages from apoptosis and can enhance cell migration during hypoxia. And cleaved Caspase9/3 pathways were involved in Apelin inhibiting RAW264.7 apoptosis. In conclusion, we showed the effect of Apelin on RAW264.7 macrophage under normal and hypoxic condition, which could further influence the angiogenesis and inflammation process that promoted by macrophages.
Subject(s)
Adipokines/metabolism , Inflammation/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Macrophages/metabolism , Peptides/metabolism , Adipokines/administration & dosage , Adipokines/genetics , Angiopoietin-2/biosynthesis , Animals , Apelin , Cell Movement/genetics , Chemokine CCL2/biosynthesis , Chemokine CCL2/genetics , Chemokine CCL4/biosynthesis , Chemokine CCL4/genetics , Gene Expression Regulation/drug effects , Inflammation/genetics , Inflammation/pathology , Intercellular Signaling Peptides and Proteins/administration & dosage , Intercellular Signaling Peptides and Proteins/genetics , Macrophages/drug effects , Macrophages/pathology , Mice , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/metabolism , Peptides/administration & dosage , Peptides/chemical synthesis , Tumor Necrosis Factor-alpha/biosynthesis , Vascular Endothelial Growth Factor A/biosynthesisABSTRACT
BACKGROUND: Clinical prognosis is critically poor in fulminant myocarditis, while it's initiation or progression is fated, in part, by T cell-mediated autoimmunity. Adiponectin (APN) and associated adipokines were shown to be immune tolerance inducers, although the clinically relevant delivery method into target pathologies is under debate. Whether the cell sheet-based delivery system of adipokines might induce immune tolerance and functional recovery in experimental autoimmune myocarditis (EAM) was tested. METHODS AND RESULTS: Scaffold-free-induced adipocyte cell-sheet (iACS) was generated by differentiating adipose tissue-derived syngeneic stromal vascular-fraction cells into adipocytes on temperature-responsive dishes. Rats with EAM underwent iACS implantation or sham operation. Supernatants of iACS contained a high level of APN and hepatocyte growth factor (HGF), and reduced proliferation of CD4-positive T cells in vitro. Immunohistolabelling showed that the iACS implantation elevated the levels of APN and HGF in the myocardium compared to the sham operation, which attenuated the immunological response by inhibiting CD68-positive macropharges and CD4-positive T-cells and activating Foxp3-positive regulatory T cells. Consequently, left ventricular ejection fraction was significantly greater after the iACS implantation than after the sham operation, in association with less collagen accumulation. CONCLUSIONS: The targeted delivery of adipokines using tissue-engineered iACS ameliorated cardiac performance of the EAM rat model via effector T cell suppression and induction of immune tolerance. These findings might suggest a potential of this tissue-engineered drug delivery system in treating fulminant myocarditis in the clinical setting.
Subject(s)
Adipocytes/transplantation , Adipokines/administration & dosage , Autoimmune Diseases/therapy , Drug Delivery Systems , Isografts/metabolism , Myocarditis/therapy , Adipocytes/metabolism , Adipokines/immunology , Adipokines/metabolism , Adipokines/therapeutic use , Adiponectin/administration & dosage , Adiponectin/metabolism , Adiponectin/pharmacology , Animals , Autoimmune Diseases/immunology , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , Cells, Cultured , Collagen/analysis , Culture Media, Conditioned/pharmacology , Heart , Hepatocyte Growth Factor/pharmacology , Immune Tolerance , Lymphocyte Activation/drug effects , Male , Myocarditis/immunology , Myocarditis/physiopathology , Myocardium/chemistry , Myocardium/pathology , Random Allocation , Rats , Rats, Inbred Lew , Recombinant Proteins/pharmacology , Stroke Volume , Tissue Engineering , Transplantation, Heterotopic , Transplantation, Isogeneic , Vascular Endothelial Growth Factor A/pharmacologyABSTRACT
Chemerin is a recently identified adipokine that is involved in the regulation of adipogenesis, energy metabolism, and inflammation. The aim of the present study was to investigate the role of chemerin on food intake, body weight and hypothalamic peptidergic and aminergic modulators which play a pivotal role in feeding regulation in rats. Male adult Wistar rats were intraperitoneally injected, daily for 17 days at 9.00am, with either vehicle (saline; N=12) or chemerin (8µg/kg; N=12) and (16µg/kg; N=12). Food intake was recorded 24h after each administration. Animals were sacrificed 24h after the last injection. Total RNA was extracted from hypothalami and reverse transcribed to evaluate gene expression of agouti-related peptide (AgRP), neuropeptide Y (NPY), orexin-A, corticotrophin releasing hormone (CRH), pro-opiomelanocortin (POMC) and cocaine and amphetamine-regulated transcript (CART). Furthermore, we evaluated the effect of chemerin on dopamine, norepinephrine and serotonin steady state concentrations in rat hypothalamus homogenate, and monoamine release from rat hypothalamic synaptosomes. Chemerin administration (8 and 16µg/kg) decreased both food intake and body weight compared to vehicle, possibly associated with a significant increase in serotonin synthesis and release, in the hypothalamus. On the other hand, the pattern of gene expression following chemerin administration indicates a minor role played by chemerin as a peripheral appetite-regulating signal.
Subject(s)
Adipokines/physiology , Appetite Regulation , Hypothalamus/physiology , Adipokines/administration & dosage , Animals , Biogenic Monoamines/biosynthesis , Chemokines , Energy Intake , Feeding Behavior , Gene Expression , Hypothalamus/drug effects , Intercellular Signaling Peptides and Proteins , Male , Rats , Rats, Wistar , Weight GainABSTRACT
INTRODUCTION: Adipocytes are nowadays recognized as cells able to produce and secrete a large variety of active substances with direct effects on vascular cells, known as adipokines. Visfatin is a recently identified adipokine not yet completely characterized for its pathophysiological role in cardiovascular disease. Increased levels of visfatin are measurable in the plasma of patients with coronary artery disease and specifically in those with acute coronary syndromes (ACS). Several studies have indicated that Tissue Factor (TF) plays a pivotal role in the pathophysiology of ACS by triggering the formation of intracoronary thrombi following endothelial injury. This study investigates the effects of visfatin on TF in human coronary endothelial cells (HCAECs). METHODS: HCAECs were stimulated with visfatin in a concentration range usually measurable in plasma of patients with ACS and than processed to evaluate TF-mRNA levels as well as TF expression/activity. Finally, the role of NF-κB pathway was investigated. RESULTS: We demonstrate that visfatin induces transcription of mRNA for TF by Real Time PCR. In addition, we show that this adipokine promotes surface expression of TF that is functionally active since we measured increased procoagulant activity. Visfatin effects on TF appear modulated by the activation of the transcription factor, NF-κB, since NF-κB inhibitors suppressed TF expression. Finally, we show that the nicotinamide phopsphoribosyltransferase enzymatic activity of visfatin seems to play a pivotal role in modulating the NF-κB driven regulation of TF. DISCUSSION: Data of the present study, although in vitro, indicate that visfatin, at doses measurable in ACS patient plasma, induces a procoagulant phenotype in human coronary endothelial cells by promoting TF expression. These observations support the hypothesis that this adipokine might play a relevant role as an active partaker in athero-thrombotic disease.
Subject(s)
Coronary Vessels/immunology , Cytokines/administration & dosage , Cytokines/immunology , Endothelial Cells/immunology , NF-kappa B/immunology , Nicotinamide Phosphoribosyltransferase/administration & dosage , Nicotinamide Phosphoribosyltransferase/immunology , Thromboplastin/immunology , Adipokines/administration & dosage , Adipokines/immunology , Cells, Cultured , Coronary Vessels/cytology , Coronary Vessels/drug effects , Dose-Response Relationship, Drug , Endothelial Cells/drug effects , Humans , Signal Transduction/drug effects , Signal Transduction/immunologyABSTRACT
AIMS: Cytokines interfere with signaling pathways and mediators of vascular contraction. Endothelin-1 (ET-1) plays a major role on vascular dysfunction in conditions characterized by increased circulating levels of adipokines. In the present study we tested the hypothesis that the adipokine chemerin increases vascular contractile responses via activation of ET-1/ET-1 receptors-mediated pathways. MAIN METHODS: Male, 10-12 week-old Wistar rats were used. Endothelium-intact and endothelium-denuded aortic rings were incubated with chemerin (0.5 ng/mL or 5 ng/mL, for 1 or 24h), and isometric contraction was recorded. Protein expression was determined by Western blotting. KEY FINDINGS: Constrictor responses to phenylephrine (PE) and ET-1 were increased in vessels treated for 1h with chemerin. Chemerin incubation for 24h decreased PE contractile response whereas it increased the sensitivity to ET-1. Endothelium removal significantly potentiated chemerin effects on vascular contractile responses to PE and ET-1. Incubation with either an ERK1/2 inhibitor (PD98059) or ETA antagonist (BQ123) abolished chemerin effects on PE- and ET-1-induced vasoconstriction. Phosphorylation of MEK1/2 and ERK1/2 was significantly increased in vessels treated with chemerin for 1 and 24h. Phosphorylation of these proteins was further increased in vessels incubated with ET-1 plus chemerin. ET-1 increased MEK1/2, ERK1/2 and MKP1 protein expression to values observed in vessels treated with chemerin. SIGNIFICANCE: Chemerin increases contractile responses to PE and ET-1 via ERK1/2 activation. Our study contributes to a better understanding of the mechanisms by which the adipose tissue affects vascular function and, consequently, the vascular alterations present in obesity and related diseases.
Subject(s)
Adipokines/administration & dosage , Aorta, Thoracic/drug effects , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Adipokines/metabolism , Animals , Aorta, Thoracic/metabolism , Blotting, Western , Chemokines , Dose-Response Relationship, Drug , Endothelin-1/administration & dosage , Endothelin-1/metabolism , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Flavonoids/pharmacology , Intercellular Signaling Peptides and Proteins , MAP Kinase Kinase 1/metabolism , MAP Kinase Kinase 2/metabolism , Male , Peptides, Cyclic/pharmacology , Phenylephrine/pharmacology , Phosphorylation/drug effects , Rats , Rats, Wistar , Time FactorsABSTRACT
Visfatin is an adipocytokine capable of mimicking the glucose-lowering effects of insulin and activating the pro-survival kinases phosphatidylinositol-3-OH kinase (PI3K)-protein kinase B (Akt) and mitogen-activated protein kinase kinase 1 and 2 (MEK1/2)-extracellular signal-regulated kinase 1 and 2 (Erk 1/2). Experimental studies have demonstrated that the activation of these kinases confers cardioprotection through the inhibition of the mitochondrial permeability transition pore (mPTP). Whether visfatin is capable of exerting direct cardioprotective effects through these mechanisms is unknown and is the subject of the current study. Anaesthetized C57BL/6 male mice were subjected to in situ 30 min. of regional myocardial ischaemia and 120 min. of reperfusion. The administration of an intravenous bolus of visfatin (5 x 10(-6) micromol) at the time of myocardial reperfusion reduced the myocardial infarct size from 46.1+/-4.1% in control hearts to 27.3+/-4.0% (n>or= 6/group, P<0.05), an effect that was blocked by the PI3K inhibitor, wortmannin, and the MEK1/2 inhibitor, U0126 (48.8+/-5.5% and 45.9+/-8.4%, respectively, versus 27.3+/-4.0% with visfatin; n>or= 6/group, P<0.05). In murine ventricular cardiomyocytes subjected to 30 min. of hypoxia followed by 30 min. of reoxygenation, visfatin (100 ng/ml), administered at the time of reoxygenation, reduced the cell death from 65.2+/-4.6% in control to 49.2+/-3.7%(n>200 cells/group, P<0.05), an effect that was abrogated by wortmannin and U0126 (68.1+/-5.2% and 59.7+/-6.2%, respectively; n>200 cells/group, P>0.05). Finally, the treatment of murine ventricular cardiomyocytes with visfatin (100 ng/ml) delayed the opening of the mPTP induced by oxidative stress from 81.2+/-4 sec. in control to 120+/-7 sec. (n>20 cells/group, P<0.05) in a PI3K- and MEK1/2-dependent manner. We report that the adipocytokine, visfatin, is capable of reducing myocardial injury when administered at the time of myocardial reperfusion in both the in situ murine heart and the isolated murine cardiomyocytes. The mechanism appears to involve the PI3K and MEK1/2 pathways and the mPTP.