RESUMEN
Interlimb coordination involving cyclical movements of hand and foot in the sagittal plane is more difficult when the limbs move in opposite directions compared with the same direction (directional constraint). Here we first investigated whether the directional constraint on hand-foot coordination exists in motor imagery (imagined motion). Participants performed 10 cyclic coordinated movements of right wrist flexion-extension and right ankle dorsiflexion-plantarflexion as quickly and precisely as possible, in the following three conditions; (1) actual movements of the two limbs, (2) imaginary movements of the two limbs, and (3) actual movement of one limb combined with imaginary movement of the other limb. Each condition was performed under two directions; the same and the opposite direction. Task execution duration was measured as the time between the first and second press of a button by the participants. The opposite directional movement took a significantly longer time than did the same directional movement, irrespective of the condition type. This suggests that directional constraint of hand-foot coordination occurs even in motor imagery without actual motor commands or kinesthetic signals. We secondarily examined whether the corticospinal excitability of wrist muscles is modulated in synchronization with an imaginary foot movement to estimate the neural basis of directional constraint on imaginary hand-foot coordination. The corticospinal excitability of the forearm extensor in resting position increased during dorsiflexion and decreased during plantarflexion similarly in both actual and imaginary foot movements. This corticospinal modulation depending on imaginary movement phase likely produces the directional constraint on the imaginary hand-foot coordination.
RESUMEN
Type 1 (T1D) or type 2 diabetes (T2D) are caused by a deficit of functional insulin-producing ß cells. Thus, the identification of ß cell trophic agents could allow the development of therapeutic strategies to counteract diabetes. The discovery of SerpinB1, an elastase inhibitor that promotes human ß cell growth, prompted us to hypothesize that pancreatic elastase (PE) regulates ß cell viability. Here, we report that PE is up-regulated in acinar cells and in islets from T2D patients, and negatively impacts ß cell viability. Using high-throughput screening assays, we identified telaprevir as a potent PE inhibitor that can increase human and rodent ß cell viability in vitro and in vivo and improve glucose tolerance in insulin-resistant mice. Phospho-antibody microarrays and single-cell RNA sequencing analysis identified PAR2 and mechano-signaling pathways as potential mediators of PE. Taken together, our work highlights PE as a potential regulator of acinar-ß cell crosstalk that acts to limit ß cell viability, leading to T2D.
Asunto(s)
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Humanos , Ratones , Animales , Células Acinares/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Elastasa Pancreática/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Comunicación CelularRESUMEN
Remnant lipoproteins (RLs), which are typically present at high concentrations in patients with type 2 diabetes mellitus (T2DM), are associated with cardiovascular disease (CVD). Although an RL cholesterol homogeneous assay (RemL-C) is available for the measurement of RL concentrations, there have been no studies of the relationship between RemL-C and clinical parameters in T2DM. Therefore, we evaluated the relationships between RemL-C and CVD-related parameters in patients with T2DM. We performed a cross-sectional study of 169 patients with T2DM who were hospitalized at Kumamoto University Hospital. Compared with those with low RemL-C, those with higher RemL-C had higher fasting plasma glucose, homeostasis model assessment for insulin resistance (HOMA-R), total cholesterol, triglyceride, small dense low-density lipoprotein cholesterol (sdLDL-C), and urinary albumin-creatinine ratio; and lower high-density lipoprotein cholesterol, adiponectin, and ankle brachial pressure index (ABI). Multivariate logistic regression analysis showed that sdLDL-C and ABI were significantly and independently associated with high RemL-C. Although LDL-C was lower in participants with CVD, there was no difference in RemL-C between participants with or without CVD. Thus, RemL-C may represent a useful index of lipid and glucose metabolism, and that may be a marker of peripheral atherosclerotic disease (PAD) in male patients with T2DM.
Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Humanos , Masculino , Estudios Transversales , Colesterol , Lipoproteínas , Triglicéridos , LDL-ColesterolRESUMEN
Palbociclib(PAL), which is a small molecule with inhibitory activity against cyclin-dependent kinase 4/6, is used in endocrine combined therapy for the treatment of estrogen receptor(ER)-positive and HER2-negative inoperable and recurrent breast cancer. We retrospectively investigated the factors associated with prolonged treatment in inoperable and recurrent breast cancer in a multicenter study. The median time-to-treatment failure(TTF)after PAL was 5.6 months(0.2-22.5). A total of 28 patients in the fulvestrant(FUL)group and 21 patients in the aromatase inhibitor(AI)group received concomitant endocrine therapy. The median TTF was 2.6 vs 6.7 months(p=0.015)for white blood cell(WBC), 3.7 vs 6.6 months (p=0.021)for neutrophils(Neu), and 2.8 vs 7.5 months(p=0.007)for lymphocytes(Lym). The treatment period tended to be prolonged in the group with higher WBC, Neu, and Lym levels than that of the standard values. The median treatment duration of the FUL group was 7.5 months vs 4.2 months(p=0.162); however, the difference was not statistically significant. The WBC, Neu, and Lym levels upon PAL introduction may be factors affecting the prolonged treatment. Further analysis of the data and further investigation of the prolongation-related factors of PAL treatment period are necessary.
Asunto(s)
Neoplasias de la Mama , Duración de la Terapia , Humanos , Femenino , Estudios Retrospectivos , Recurrencia Local de Neoplasia , Neoplasias de la Mama/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica , Receptor ErbB-2/análisisRESUMEN
Insulin signaling is mediated via a network of protein phosphorylation. Dysregulation of this network is central to obesity, type 2 diabetes and metabolic syndrome. Here we investigate the role of phosphatase binding protein Alpha4 (α4) that is essential for the serine/threonine protein phosphatase 2A (PP2A) in insulin action/resistance in adipocytes. Unexpectedly, adipocyte-specific inactivation of α4 impairs insulin-induced Akt-mediated serine/threonine phosphorylation despite a decrease in the protein phosphatase 2A (PP2A) levels. Interestingly, loss of α4 also reduces insulin-induced insulin receptor tyrosine phosphorylation. This occurs through decreased association of α4 with Y-box protein 1, resulting in the enhancement of the tyrosine phosphatase protein tyrosine phosphatase 1B (PTP1B) expression. Moreover, adipocyte-specific knockout of α4 in male mice results in impaired adipogenesis and altered mitochondrial oxidation leading to increased inflammation, systemic insulin resistance, hepatosteatosis, islet hyperplasia, and impaired thermogenesis. Thus, the α4 /Y-box protein 1(YBX1)-mediated pathway of insulin receptor signaling is involved in maintaining insulin sensitivity, normal adipose tissue homeostasis and systemic metabolism.
Asunto(s)
Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Adipocitos/metabolismo , Animales , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Homeostasis , Insulina/metabolismo , Masculino , Ratones , Fosforilación , Proteína Fosfatasa 2/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 1/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Serina/metabolismo , Treonina/metabolismo , Tirosina/metabolismoRESUMEN
Triagonists of GLP-1R/ GIPR /GCGR, including SAR441255, bind to each receptor and induce specific effects through each receptor signaling pathway, thus result in weight loss and glycemic control in obese T2D animal models.
Asunto(s)
Diabetes Mellitus Tipo 2 , Receptor del Péptido 1 Similar al Glucagón , Animales , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Receptores de Glucagón/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Polipéptido Inhibidor Gástrico/metabolismo , Obesidad/complicaciones , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Receptores Acoplados a Proteínas GRESUMEN
In contrast to most mammals including human, fish cell lines have long been known to be immortal, with little sign of cellular senescence, despite the absence of transformation. Recently, our laboratory reported that DNA demethylation with 5-aza-2'-deoxycytidine (5-Aza-dC) induces telomere-independent cellular senescence and senescence-associated secretory phenotype (SASP) in an immortal fish cell line, EPC (Epithelioma papulosum cyprini). However, it is not known how fish derived cultured cells are usually resistant to aging in vitro. In this study, we focused on Ras, which carries out the main role of Ras-induced senescence (RIS), and investigated the role of Ras in the regulation of senescence in EPC cells. Our results show that 5-Aza-dC induced the expression of the ras (hras, kras, nras) gene in EPC cells. EPC cells overexpressing HRas or its constitutively active form (HRasV12) showed p53-dependent senescence-like growth arrest and senescence-associated ß-galactosidase (SA-ß-gal) activity with a large and/or flat morphology characteristic of cell senescence. On the other hand, the SASP was not induced. These results imply that the increased expression of HRas contributes to early senescence in EPC cells, but it alone may not be sufficient for the full senescence, even if HRas is aberrantly activated. Thus, the limited mechanism of RIS may play a role in the senescence-resistance of fish cell lines.
Asunto(s)
Senescencia Celular/genética , Genes ras/genética , Genes ras/fisiología , Envejecimiento/genética , Envejecimiento/metabolismo , Animales , Línea Celular , Células Cultivadas , Senescencia Celular/fisiología , Peces/genética , Humanos , Proteínas Proto-Oncogénicas p21(ras)/genéticaRESUMEN
OBJECTIVE: In elderly patients, age-related, disease-related, and drug-related factors are associated with chronic kidney disease (CKD). Little is known about which factors are the best predictors for CKD in elderly patients. MATERIALS AND METHODS: The study was based on 784 patients aged 75 years or older for whom the clinical and serum creatinine on admission to our hospital were available. Impaired renal function, including CKD and transient renal insufficiency, was defined as a non-indexed glomerular filtration rate (GFR) below 60 mL/min. A logistic regression model was developed for predictors of CKD and was internally validated using bootstrapping. RESULTS: Approximately 61% of the patients, who had CKD (46%) and transient renal insufficiency (15%), had a non-indexed GFR < 60 mL/min. Synergistic use of 3 drugs potentially impairing renal function, diuretics, ACE-I/ARB, and NSAIDs (odds ratio (OR), 4.66; 95% confidence interval (CI), 1.48 - 17.7, p = 0.012) was a significantly associated factor for CKD in a multivariate logistic regression analysis. Age (OR 1.56, 95% CI 1.04 - 2.33, p = 0.03), female gender (OR 1.58, 95% CI 1.04 - 2.39, p = 0.03), any prescription ACE-I/ARB either alone or in combinations with diuretics or NSAIDs (OR 2.74, 95% CI 1.83 - 4.13, p = 0.0001), and proteinuria (OR 1.98, 95% CI 1.27 - 3.10, p = 0.003), were included as the best model for CKD. The area under the curve (AUC) of the best model and the bootstrapping validation were 0.68 and 0.71, respectively. CONCLUSION: Given the widespread use of ACE-I/ARB for elderly patients, our findings suggest that caution is needed when they are prescribed because of the possibility of the patient developing CKD.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Antiinflamatorios no Esteroideos/efectos adversos , Diuréticos/efectos adversos , Prescripción Inadecuada/estadística & datos numéricos , Insuficiencia Renal Crónica/inducido químicamente , Anciano , Creatinina/sangre , Estudios Transversales , Femenino , Tasa de Filtración Glomerular , Humanos , Pacientes Internos , MasculinoRESUMEN
OBJECTIVE: Macrophages play a central role in various stages of atherosclerotic plaque formation and progression. The local macrophages reportedly proliferate during atherosclerosis, but the pathophysiological significance of macrophage proliferation in this context remains unclear. Here, we investigated the involvement of local macrophage proliferation during atherosclerosis formation and progression using transgenic mice, in which macrophage proliferation was specifically suppressed. APPROACH AND RESULTS: Inhibition of macrophage proliferation was achieved by inducing the expression of cyclin-dependent kinase inhibitor 1B, also known as p27kip, under the regulation of a scavenger receptor promoter/enhancer. The macrophage-specific human p27kip Tg mice were subsequently crossed with apolipoprotein E-deficient mice for the atherosclerotic plaque study. Results showed that a reduced number of local macrophages resulted in marked suppression of atherosclerotic plaque formation and inflammatory response in the plaque. Moreover, fewer local macrophages in macrophage-specific human p27kip Tg mice helped stabilize the plaque, as evidenced by a reduced necrotic core area, increased collagenous extracellular matrix, and thickened fibrous cap. CONCLUSIONS: These results provide direct evidence of the involvement of local macrophage proliferation in formation and progression of atherosclerotic plaques and plaque stability. Thus, control of macrophage proliferation might represent a therapeutic target for treating atherosclerotic diseases.
Asunto(s)
Aorta/patología , Aortitis/prevención & control , Aterosclerosis/prevención & control , Proliferación Celular , Activación de Macrófagos , Macrófagos Peritoneales/patología , Placa Aterosclerótica , Animales , Aorta/metabolismo , Aortitis/genética , Aortitis/metabolismo , Aortitis/patología , Aterosclerosis/genética , Aterosclerosis/metabolismo , Aterosclerosis/patología , Células Cultivadas , Colágeno/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Modelos Animales de Enfermedad , Fibrosis , Mediadores de Inflamación/metabolismo , Macrófagos Peritoneales/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Ratones Transgénicos , Necrosis , Transducción de SeñalRESUMEN
AIMS/INTRODUCTION: The aim of the present prospective observational study was to assess long-term efficacy and safety of insulin degludec as a part of a basal-bolus therapy for Japanese patients with type 1 or type 2 diabetes in routine clinical practice. MATERIALS AND METHODS: In the present study, 93 type 1 diabetes patients and 135 type 2 diabetes patients treated with insulin glargine or detemir were switched from their basal insulin to insulin degludec. The primary end-points were the changes in glycated hemoglobin (HbA1c) from baseline at 3, 6 and 12 months. The secondary end-points were changes in body mass index, insulin dose, frequency of hypoglycemia and adverse events. RESULTS: HbA1c levels from baseline were significantly reduced at 3, 6, and 12 months by 0.4, 0.4 and 0.3% in type 1 diabetes patients, respectively, and by 0.5, 0.5 and 0.3% in type 2 diabetes patients, respectively. Body mass index in type 1 diabetes patients increased significantly (P < 0.05), whereas that in type 2 diabetes patients did not change. Basal insulin dose decreased significantly at 3 months after switching (P < 0.05), and returned baseline dose at 12 months in type 1 diabetes and type 2 diabetes patients. The frequency of both total and nocturnal hypoglycemia decreased significantly in type 1 diabetes and type 2 diabetes patients (P < 0.05). The result of multiple regression analysis showed that baseline HbA1c was a significant independent variable of the percentage change in HbA1c with switching. CONCLUSION: In both type 1 diabetes and type 2 diabetes patients, switching from insulin glargine or insulin detemir to insulin degludec led to improvement of glycemic control with a significant reduction of hypoglycemia.
Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulina Detemir/uso terapéutico , Insulina Glargina/uso terapéutico , Insulina de Acción Prolongada/uso terapéutico , Anciano , Pueblo Asiatico , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 2/sangre , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Hipoglucemiantes/efectos adversos , Insulina Detemir/efectos adversos , Insulina Glargina/efectos adversos , Insulina de Acción Prolongada/efectos adversos , Japón , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Estudios Prospectivos , Resultado del TratamientoRESUMEN
The peroxisome proliferator-activated receptor-γ (PPARγ) is an important regulator of lipid and glucose metabolism, and its activation is reported to suppress the progression of atherosclerosis. We have reported that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) activate PPARγ in macrophages. However, it is not yet known whether statins activate PPARγ in other vascular cells. In the present study, we investigated whether statins activate PPARγ in smooth muscle cells (SMCs) and endothelial cells (ECs) and thus mediate anti-atherosclerotic effects. Human aortic SMCs (HASMCs) and human umbilical vein ECs (HUVECs) were used in this study. Fluvastatin and pitavastatin activated PPARγ in HASMCs, but not in HUVECs. Statins induced cyclooxygenase-2 (COX-2) expression in HASMCs, but not in HUVECs. Moreover, treatment with COX-2-siRNA abrogated statin-mediated PPARγ activation in HASMCs. Statins suppressed migration and proliferation of HASMCs, and inhibited lipopolysaccharide-induced expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) in HASMCs. These effects of statins were abrogated by treatment with PPARγ-siRNA. Treatment with statins suppressed atherosclerotic lesion formation in Apoe(-/-) mice. In addition, transcriptional activity of PPARγ and CD36 expression were increased, and the expression of MCP-1 and TNF-α was decreased, in the aorta of statin-treated Apoe(-/-) mice. In conclusion, statins mediate anti-atherogenic effects through PPARγ activation in SMCs. These effects of statins on SMCs may be beneficial for the prevention of atherosclerosis.
Asunto(s)
Aterosclerosis/tratamiento farmacológico , Aterosclerosis/metabolismo , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , PPAR gamma/metabolismo , Animales , Aorta/patología , Apolipoproteínas E/deficiencia , Apolipoproteínas E/metabolismo , Aterosclerosis/enzimología , Aterosclerosis/patología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Quimiocina CCL2/metabolismo , Ciclooxigenasa 2/metabolismo , Progresión de la Enfermedad , Ácidos Grasos Monoinsaturados/farmacología , Fluvastatina , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Indoles/farmacología , Lipopolisacáridos , Ratones Endogámicos C57BL , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , FN-kappa B/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The effects of high-fat diet (HFD) and postprandial endotoxemia on the development of type 2 diabetes are not fully understood. Here we show that the serine protease prostasin (PRSS8) regulates hepatic insulin sensitivity by modulating Toll-like receptor 4 (TLR4)-mediated signalling. HFD triggers the suppression of PRSS8 expression by inducing endoplasmic reticulum (ER) stress and increases the TLR4 level in the liver. PRSS8 releases the ectodomain of TLR4 by cleaving it, which results in a reduction in the full-length form and reduces the activation of TLR4. Liver-specific PRSS8 knockout (LKO) mice develop insulin resistance associated with the increase in hepatic TLR4. Restoration of PRSS8 expression in livers of HFD, LKO and db/db mice decreases the TLR4 level and ameliorates insulin resistance. These results identify a novel physiological role for PRSS8 in the liver and provide new insight into the development of diabetes resulting from HFD or metabolic endotoxemia.
Asunto(s)
Resistencia a la Insulina , Hígado/metabolismo , Serina Endopeptidasas/metabolismo , Transducción de Señal , Receptor Toll-Like 4/metabolismo , Animales , Índice de Masa Corporal , Membrana Celular/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Dieta Alta en Grasa , Retículo Endoplásmico/metabolismo , Intolerancia a la Glucosa/genética , Humanos , Immunoblotting , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Mutantes , Interferencia de ARN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Serina Endopeptidasas/sangre , Serina Endopeptidasas/genética , Receptor Toll-Like 4/genéticaRESUMEN
BACKGROUND: An increased leukocyte count is an independent risk factor for cardiovascular events, but the association between leukocyte subtype counts and carotid atherosclerosis in patients with diabetes has not been determined. We therefore investigated the correlation between leukocyte subtype counts and intima-media thickness of the common carotid artery (CCA-IMT) in subjects with type 2 diabetes. METHODS: This cross-sectional study involved 484 in-patients with type 2 diabetes (282 males and 202 females), who were hospitalized for glycemic control and underwent carotid ultrasonography at Kumamoto University Hospital between 2005 and 2011. Mean and maximum CCA-IMT was measured by high-resolution B-mode ultrasonography. RESULTS: Univariate analyses revealed that mean CCA-IMT was positively correlated with age, systolic blood pressure, brachial-ankle pulse wave velocity (PWV), urinary albumin excretion and duration of diabetes, but was negatively correlated with diastolic blood pressure and fasting plasma glucose. Maximum CCA-IMT was positively and negatively correlated with the same factors as mean CCA-IMT except for fasting plasma glucose. Mean CCA-IMT was positively correlated with total leukocyte (r = 0.124, p = 0.007), monocyte (r = 0.373, p < 0.001), neutrophil (r = 0.139, p = 0.002) and eosinophil (r = 0.107, p = 0.019) counts. Maximum CCA-IMT was positively correlated with total leukocyte (r = 0.154, p < 0.001), monocyte (r = 0.398, p < 0.001), neutrophil (r = 0.152, p < 0.001) and basophil counts (r = 0.102, p = 0.027). Multiple regression analyses showed that monocyte count, age and PWV were significant and independent factors associated with mean CCA-IMT (adjusted R2 = 0.239, p < 0.001), and that monocyte count, age and urinary albumin excretion were significant and independent factors associated with maximum CCA-IMT (adjusted R2 = 0.277, p < 0.001). CONCLUSIONS: Monocyte counts were positively correlated with both mean CCA-IMT and maximum CCA-IMT in patients with type 2 diabetes. Monocyte count may be a useful predictor of macrovascular complications in patients with type 2 diabetes. TRIAL REGISTRATION: Trial registry no: UMIN000003526.
Asunto(s)
Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/sangre , Diabetes Mellitus Tipo 2/sangre , Eosinófilos , Monocitos , Neutrófilos , Factores de Edad , Anciano , Albuminuria/complicaciones , Índice Tobillo Braquial , Pueblo Asiatico , Glucemia , Presión Sanguínea , Enfermedades de las Arterias Carótidas/complicaciones , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Grosor Intima-Media Carotídeo , Estudios Transversales , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Femenino , Humanos , Hipoglucemiantes/uso terapéutico , Recuento de Leucocitos , Modelos Lineales , Masculino , Persona de Mediana Edad , Análisis de la Onda del Pulso , Factores de RiesgoRESUMEN
Tumor necrosis factor α (TNFα) is a pro-inflammatory cytokine and one of the major mediators of obesity-induced insulin resistance. TNFα is generated through TNFα converting enzyme (TACE)-mediated cleavage of the transmembrane precursor pro-TNFα. Inhibition of TACE resulted in the improvement in glucose and insulin levels in diabetic animals, suggesting a crucial role of TACE activity in glucose metabolism. However, the regulation of TACE activity in insulin-sensitive tissues has not been fully determined. This study aimed to investigate the impact of TACE in insulin-sensitive tissues in the early stage of the development of obesity. C57BL6 mice were fed standard chow (B6-SC) or high-fat/high-sucrose diet (B6-HF/HS). KK-Ay mice were fed SC ad libitum (Ay-AL) or fed reduced amounts of SC (caloric restriction (CR); Ay-CR). As control for Ay-AL, KK mice fed SC ad libitum (KK-AL) were used. TACE activity in visceral adipose tissue (VAT), but not in liver or skeletal muscle, was significantly elevated in B6-HF/HS and Ay-AL compared with B6-SC and KK-AL, respectively. Phosphorylation of JNK and p38MAPK, but not ERK, in VATs from B6-HF/HS and Ay-AL was also significantly elevated. Ay-CR showed significantly lower TACE, JNK and p38MAPK activities in VAT and serum TNFα level compared with those of Ay-AL. In contrast, intraperitoneal injection of TNFα activated TACE, JNK and p38MAPK activities in VAT in KK mice. In conclusion, during the development of obesity, TACE activity is elevated only in VAT, and CR effectively reduced TACE activity and TACE-mediated pro-TNFα shedding in VAT.
Asunto(s)
Proteínas ADAM/metabolismo , Tejido Adiposo/enzimología , Obesidad/enzimología , Proteína ADAM17 , Animales , Restricción Calórica , MAP Quinasa Quinasa 4/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Fosforilación , Regulación hacia Arriba , Vísceras/enzimología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Production of reactive oxygen species (ROS) and other proinflammatory substances by macrophages plays an important role in atherogenesis. Apocynin (4-hydroxy-3-methoxy-acetophenone), which is well known as a NADPH oxidase inhibitor, has anti-inflammatory effects including suppression of the generation of ROS. However, the suppressive effects of apocynin on the progression of atherosclerosis are not clearly understood. Thus, we investigated anti-atherosclerotic effects of apocynin using apolipoprotein E-deficient (apoE(-/-)) mice in vivo and in mouse peritoneal macrophages in vitro. In atherosclerosis-prone apoE(-/-) mice, apocynin suppressed the progression of atherosclerosis, decreased 4-hydroxynonenal-positive area in atherosclerotic lesions, and mRNA expression of monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) in aorta. In mouse peritoneal macrophages, apocynin suppressed the Ox-LDL-induced ROS generation, mRNA expression of MCP-1, IL-6 and granulocyte/macrophage colony-stimulating factor, and cell proliferation. Moreover, immunohistochemical studies revealed that apocynin decreased the number of proliferating cell nuclear antigen-positive macrophages in atherosclerotic lesions of apoE(-/-) mice. These results suggested that apocynin suppressed the formation of atherosclerotic lesions, at least in part, by inactivation of macrophages. Therefore, apocynin may be a potential therapeutic material to prevent the progression of atherosclerosis.
Asunto(s)
Acetofenonas/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Aterosclerosis/tratamiento farmacológico , Macrófagos/efectos de los fármacos , Animales , Apolipoproteínas E/genética , Aterosclerosis/patología , Quimiocina CCL2/biosíntesis , Factor Estimulante de Colonias de Granulocitos/biosíntesis , Interleucina-6/biosíntesis , Lipoproteínas LDL/metabolismo , Ratones , Ratones Mutantes , ARN Mensajero/biosíntesis , Especies Reactivas de Oxígeno/antagonistas & inhibidoresRESUMEN
OBJECTIVE: Telmisartan, an angiotensin type I receptor blocker (ARB), protects against the progression of atherosclerosis. Here, we investigated the molecular basis of the antiatherosclerotic effects of telmisartan in macrophages and apolipoprotein E-deficient mice. METHODS AND RESULTS: In macrophages, telmisartan increased peroxisome proliferator-activated receptor-γ (PPARγ) activity and PPAR ligand-binding activity. In contrast, 3 other ARBs, losartan, valsartan, and olmesartan, did not affect PPARγ activity. Interestingly, high doses of telmisartan activated PPARα in macrophages. Telmisartan induced the mRNA expression of CD36 and ATP-binding cassette transporters A1 and G1 (ABCA1/G1), and these effects were abrogated by PPARγ small interfering RNA. Telmisartan, but not other ARBs, inhibited lipopolysaccharide-induced mRNA expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α, and these effects were abrogated by PPARγ small interfering RNA. Moreover, telmisartan suppressed oxidized low-density lipoprotein-induced macrophage proliferation through PPARγ activation. In apolipoprotein E(-/-) mice, telmisartan increased the mRNA expression of ABCA1 and ABCG1, decreased atherosclerotic lesion size, decreased the number of proliferative macrophages in the lesion, and suppressed MCP-1 and tumor necrosis factor-α mRNA expression in the aorta. CONCLUSION: Telmisartan induced ABCA1/ABCG1 expression and suppressed MCP-1 expression and macrophage proliferation by activating PPARγ. These effects may induce antiatherogenic effects in hypertensive patients.
Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Aterosclerosis/tratamiento farmacológico , Bencimidazoles/farmacología , Benzoatos/farmacología , Macrófagos/efectos de los fármacos , PPAR gamma/efectos de los fármacos , Animales , Apolipoproteínas E/fisiología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Quimiocina CCL2/biosíntesis , Regulación de la Expresión Génica/efectos de los fármacos , Lipoproteínas LDL/antagonistas & inhibidores , Masculino , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Telmisartán , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
OBJECTIVE: Nifedipine, an L-type calcium channel blocker, protects against the progression of atherosclerosis. We investigated the molecular basis of the antiatherosclerotic effect of nifedipine in macrophages and apolipoprotein E-deficient mice. METHODS AND RESULTS: In macrophages, nifedipine increased peroxisome proliferator-activated receptor-gamma (PPARgamma) activity without increasing PPARgamma-binding activity. Amlodipine, another L-type calcium channel blocker, and 1,2-bis-(o-aminophenoxy)-ethane-N,N,-N',N'-tetraacetic acid tetraacetoxy-methyl ester (BAPTA-AM), a calcium chelator, decreased PPARgamma activity, suggesting that nifedipine does not activate PPARgamma via calcium channel blocker activity. Inactivation of extracellular signal-regulated kinase 1/2 suppressed PPARgamma2-Ser112 phosphorylation and induced PPARgamma activation. Nifedipine suppressed extracellular signal-regulated kinase 1/2 activation and PPARgamma2-Ser112 phosphorylation, and mutating PPARgamma2-Ser112 to Ala abrogated nifedipine-mediated PPARgamma activation. These results suggested that nifedipine inhibited extracellular signal-regulated kinase 1/2 activity and PPARgamma2-Ser112 phosphorylation, leading to PPARgamma activation. Nifedipine inhibited lipopolysaccharide-induced monocyte chemoattractant protein-1 expression and induced ATP-binding cassette transporter A1 mRNA expression, and these effects were abrogated by small interfering RNA for PPARgamma. Furthermore, in apolipoprotein E-deficient mice, nifedipine treatment decreased atherosclerotic lesion size, phosphorylation of PPARgamma2-Ser112 and extracellular signal-regulated kinase 1/2, and monocyte chemoattractant protein-1 mRNA expression and increased ATP-binding cassette transporter A1 expression in the aorta. CONCLUSIONS: Nifedipine unlike amlodipine inhibits PPARgamma-Ser phosphorylation and activates PPARgamma to suppress monocyte chemoattractant protein-1 expression and induce ATP-binding cassette transporter A1 expression in macrophages. These effects may induce antiatherogenic effects in hypertensive patients.