RESUMEN
Apoptotic cells are rapidly engulfed and removed by phagocytes after displaying cell surface eat-me signals. Among many phospholipids, only phosphatidylserine (PS) is known to act as an eat-me signal on apoptotic cells. Using unbiased proteomics, we identified externalized phosphatidylinositides (PIPs) as apoptotic eat-me signals recognized by CD14+ phagocytes. Exofacial PIPs on the surfaces of early and late-apoptotic cells were observed in patches and blebs using anti-PI(3,4,5)P3 antibody, AKT- and PLCδ PH-domains, and CD14 protein. Phagocytosis of apoptotic cells was blocked either by masking exofacial PIPs or by CD14 knockout in phagocytes. We further confirmed that exofacial PIP+ thymocytes increased dramatically after in vivo irradiation and that exofacial PIP+ cells represented more significant populations in tissues of Cd14-/- than WT mice, especially after induction of apoptosis. Our findings reveal exofacial PIPs to be previously unknown cell death signals recognized by CD14+ phagocytes.
Asunto(s)
Fagocitosis , Transducción de Señal , Animales , Apoptosis/fisiología , Ratones , Fagocitos/metabolismo , Fagocitosis/fisiología , Fosfatidilserinas/metabolismo , Transducción de Señal/fisiologíaRESUMEN
Nuclear factor (NF)κB is a transcription factor that controls immune and inflammatory signaling pathways. In skeletal muscle, NFκB has been implicated in the regulation of metabolic processes and tissue mass, yet its affects on mitochondrial function in this tissue are unclear. To investigate the role of NFκB on mitochondrial function and its relationship with muscle mass across the life span, we study a mouse model with muscle-specific NFκB suppression (muscle-specific IκBα super-repressor [MISR] mice). In wild-type mice, there was a natural decline in muscle mass with aging that was accompanied by decreased mitochondrial function and mRNA expression of electron transport chain subunits. NFκB inactivation downregulated expression of PPARGC1A, and upregulated TFEB and PPARGC1B. NFκB inactivation also decreased gastrocnemius (but not soleus) muscle mass in early life (1-6 months old). Lower oxygen consumption rates occurred in gastrocnemius and soleus muscles from young MISR mice, whereas soleus (but not gastrocnemius) muscles from old MISR mice displayed increased oxygen consumption compared to age-matched controls. We conclude that the NFκB pathway plays an important role in muscle development and growth. The extent to which NFκB suppression alters mitochondrial function is age dependent and muscle specific. Finally, mitochondrial function and muscle mass are tightly associated in both genotypes and across the life span.
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Mitocondrias Musculares/fisiología , Desarrollo de Músculos/fisiología , FN-kappa B/fisiología , Envejecimiento/genética , Envejecimiento/patología , Envejecimiento/fisiología , Animales , Citrato (si)-Sintasa/metabolismo , Regulación del Desarrollo de la Expresión Génica , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mitocondrias Musculares/genética , Desarrollo de Músculos/genética , Músculo Esquelético/fisiología , Músculo Esquelético/ultraestructura , FN-kappa B/antagonistas & inhibidores , Consumo de Oxígeno , Transducción de SeñalRESUMEN
Oxytocin sets the stage for childbirth by initiating uterine contractions, lactation and maternal bonding behaviours. Mice lacking secreted oxcytocin (Oxt -/-, Cd38 -/-) or its receptor (Oxtr -/-) fail to nurture. Normal maternal behaviour is restored by peripheral oxcytocin replacement in Oxt -/- and Cd38 -/-, but not Oxtr -/- mice, implying that circulating oxcytocin crosses the blood-brain barrier. Exogenous oxcytocin also has behavioural effects in humans. However, circulating polypeptides are typically excluded from the brain. We show that oxcytocin is transported into the brain by receptor for advanced glycation end-products (RAGE) on brain capillary endothelial cells. The increases in oxcytocin in the brain which follow exogenous administration are lost in Ager -/- male mice lacking RAGE, and behaviours characteristic to abnormalities in oxcytocin signalling are recapitulated in Ager -/- mice, including deficits in maternal bonding and hyperactivity. Our findings show that RAGE-mediated transport is critical to the behavioural actions of oxcytocin associated with parenting and social bonding.
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Encéfalo/metabolismo , Conducta Materna/fisiología , Apego a Objetos , Oxitocina/metabolismo , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Animales , Células Endoteliales/metabolismo , Femenino , Humanos , Masculino , Conducta Materna/psicología , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Receptor para Productos Finales de Glicación Avanzada/sangre , Receptor para Productos Finales de Glicación Avanzada/genética , Receptores de Oxitocina/genética , Receptores de Oxitocina/metabolismoRESUMEN
Older adults universally suffer from sarcopenia and approximately 60-70% are diabetic or prediabetic. Nonetheless, the mechanisms underlying these aging-related metabolic disorders are unknown. NFκB has been implicated in the pathogenesis of several aging-related pathologies including sarcopenia and type 2 diabetes and has been proposed as a target against them. NFκB also is thought to mediate muscle wasting seen with disuse, denervation, and some systemic diseases (e.g., cancer, sepsis). We tested the hypothesis that lifelong inhibition of the classical NFκB pathway would protect against aging-related sarcopenia and insulin resistance. Aged mice with muscle-specific overexpression of a super-repressor IκBα mutant (MISR) were protected from insulin resistance. However, MISR mice were not protected from sarcopenia; to the contrary, these mice had decreases in muscle mass and strength compared to wild-type mice. In MISR mice, NFκB suppression also led to an increase in proteasome activity and alterations in several genes and pathways involved in muscle growth and atrophy (e.g., myostatin). We conclude that the mechanism behind aging-induced sarcopenia is NFκB independent and differs from muscle wasting due to pathologic conditions. Our findings also indicate that, while suppressing NFκB improves insulin sensitivity in aged mice, this transcription factor is important for normal muscle mass maintenance and its sustained inhibition is detrimental to muscle function.
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Envejecimiento/metabolismo , Resistencia a la Insulina , Músculo Esquelético/metabolismo , Miostatina/genética , FN-kappa B/genética , Sarcopenia/genética , Envejecimiento/patología , Animales , Glucemia/metabolismo , Carnitina/análogos & derivados , Carnitina/metabolismo , Línea Celular , Ceramidas/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Músculo Esquelético/patología , Atrofia Muscular/genética , Atrofia Muscular/metabolismo , Atrofia Muscular/patología , Mioblastos/metabolismo , Mioblastos/patología , Inhibidor NF-kappaB alfa/genética , Inhibidor NF-kappaB alfa/metabolismo , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Sarcopenia/metabolismo , Sarcopenia/patologíaRESUMEN
TBC1D4 (also known as AS160) is a Rab·GTPase-activating protein (RabGAP) which functions in insulin signaling. TBC1D4 is critical for translocation of glucose transporter 4 (GLUT4), from an inactive, intracellular, vesicle-bound site to the plasma membrane, where it promotes glucose entry into cells. The TBC1D4 protein is structurally subdivided into two N-terminal phosphotyrosine-binding (PTB) domains, a C-terminal catalytic RabGAP domain, and a disordered segment in between containing potential Akt phosphorylation sites. Structural predictions further suggest that a region C-terminal to the RabGAP domain adopts a coiled-coil motif. We show that C-terminal region (CTR) region is largely α-helical and mediates TBC1D4 RabGAP dimerization. RabGAP catalytic activity and thermal stability appear to be independent of CTR-mediated dimerization.
Asunto(s)
Proteínas Activadoras de GTPasa/química , Multimerización de Proteína , Humanos , Dominios Proteicos , Estabilidad Proteica , Estructura Cuaternaria de Proteína , TemperaturaRESUMEN
OBJECTIVE: To assess long-term efficacy and safety of salsalate to improve glycemia in persons with diabetes risk, who are overweight with statin-treated, stable coronary heart disease. METHODS: Glycemic status was assessed in 192 persons without diabetes at baseline in a pre-specified secondary analysis from Targeting INflammation Using SALsalate in CardioVascular Disease (TINSAL-CVD), a multi-center, double-masked, randomized (1:1), placebo-controlled, parallel clinical trial. RESULTS: Participants were mostly Caucasian males, age 60±7 years, BMI 31.4±3.0 kg/m2 , fasting glucose 92.8±11.0 mg/dL, and HbA1c 5.8±0.3%. Reductions in mean fasting glucose -5.70 mg/dL (95%CI: -7.44 to -3.97 mg/dL, P<0.001), HbA1c -0.11% (95%CI: -0.210 to -0.002%, P=0.046) and glycated serum protein -81.8 µg/mL (95%CI: -93.7 to -69.9 µg/mL, P<0.001) were demonstrated in salsalate compared to placebo-assigned groups over 30 months. Reductions in fasting glucose and glycated serum protein were greater with salsalate compared to placebo in participants with prediabetes compared to a normoglycemic sub-group (Pinteraction =0.018). Salsalate lowered total white blood cell counts (mean difference -0.7x103 /µL, 95%CI: -1.0 to -0.4 x103 /µL, P<0.001) and increased adiponectin (mean difference 1.8 µg/mL, 95%CI: 0.9 to 2.6 µg/mL, P<0.001) and albuminurea (16.7 µg/mg, 95%CI: 6.4 to 27.1 µg/mg, P<0.001) compared to placebo, consistent with previous results for patients with type 2 diabetes taking salsalate for shorter times. CONCLUSIONS: Salsalate improves glycemia in obese persons at increased risk for diabetes, and hence may decrease risk of incident type 2 diabetes. Salsalate may inform new therapeutic approaches for diabetes prevention, but renal safety may limit clinical utility.
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Glucemia/efectos de los fármacos , Enfermedades Cardiovasculares/tratamiento farmacológico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Sobrepeso/sangre , Sobrepeso/tratamiento farmacológico , Estado Prediabético/sangre , Estado Prediabético/tratamiento farmacológico , Salicilatos/uso terapéutico , Adulto , Anciano , Glucemia/metabolismo , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/complicaciones , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sobrepeso/complicaciones , Placebos , Estado Prediabético/complicaciones , Factores de Riesgo , Resultado del TratamientoRESUMEN
Obesity-related sub-acute chronic inflammation has been associated with incident type 2 diabetes and atherosclerotic cardiovascular disease. Inflammation is increasingly considered to be a pathologic mediator of these commonly co-occurring diseases. A growing number of preclinical and clinical studies support the inflammatory hypothesis, but clinical trials to confirm the therapeutic potential to target inflammation to treat or prevent cardiometabolic conditions are still ongoing. There are multiple inflammatory signaling pathways. Regulation is complex, with substantial crosstalk across these multiple pathways. The activity of select pathways may be differentially regulated in different tissues. Pharmacologic approaches to diabetes management may have direct or indirect antiinflammatory effects, the latter potentially attributable to an improved metabolic state. Conversely, some antiinflammatory approaches may affect glucose metabolism and cardiovascular health. To date, clinical trials suggest that targeting one portion of the inflammatory cascade may differentially affect dysglycemia and atherothrombosis. Understanding the underlying biological processes may contribute to the development of safe and effective therapies, although a single approach may not be sufficient for optimal management of both metabolic and athrothrombotic disease states.
Asunto(s)
Aterosclerosis , Complicaciones de la Diabetes , Diabetes Mellitus Tipo 2 , Trombosis , Animales , Aterosclerosis/etiología , Aterosclerosis/inmunología , Aterosclerosis/patología , Aterosclerosis/terapia , Complicaciones de la Diabetes/inmunología , Complicaciones de la Diabetes/patología , Complicaciones de la Diabetes/terapia , Diabetes Mellitus Tipo 2/inmunología , Diabetes Mellitus Tipo 2/patología , Diabetes Mellitus Tipo 2/terapia , Glucosa/inmunología , Humanos , Inflamación/inmunología , Inflamación/patología , Inflamación/terapia , Trombosis/etiología , Trombosis/inmunología , Trombosis/patología , Trombosis/terapiaRESUMEN
Skeletal muscle is a highly regenerative tissue, but muscle repair potential is increasingly compromised with advancing age. In this study, we demonstrate that increased NF-κB activity in aged muscle fibers contributes to diminished myogenic potential of their associated satellite cells. We further examine the impact of genetic modulation of NF-κB signaling in muscle satellite cells or myofibers on recovery after damage. These studies reveal that NF-κB activity in differentiated myofibers is sufficient to drive dysfunction of muscle regenerative cells via cell-non-autonomous mechanisms. Inhibition of NF-κB, or its downstream target Phospholipase A2, in myofibers rescued muscle regenerative potential in aged muscle. Moreover, systemic administration of sodium salicylate, an FDA-approved NF-κB inhibitor, decreased inflammatory gene expression and improved repair in aged muscle. Together, these studies identify a unique NF-κB regulated, non-cell autonomous mechanism by which stem cell function is linked to lipid signaling and homeostasis, and provide important new targets to stimulate muscle repair in aged individuals.
Asunto(s)
Fibras Musculares Esqueléticas/metabolismo , FN-kappa B/metabolismo , Células Satélite del Músculo Esquelético/metabolismo , Anciano , Envejecimiento/fisiología , Animales , Antiinflamatorios no Esteroideos/farmacología , Senescencia Celular , Expresión Génica , Humanos , Ratones , Desarrollo de Músculos/efectos de los fármacos , Fibras Musculares Esqueléticas/efectos de los fármacos , Regeneración , Células Satélite del Músculo Esquelético/efectos de los fármacos , Salicilato de Sodio/farmacología , Nicho de Células MadreRESUMEN
IMPORTANCE: Inflammation may contribute to pathological associations among obesity, diabetes mellitus, and cardiovascular disease. OBJECTIVE: To determine whether targeting inflammation using salsalate compared with placebo reduces progression of noncalcified coronary artery plaque. DESIGN, SETTING, AND PARTICIPANTS: In the Targeting Inflammation Using Salsalate in Cardiovascular Disease (TINSAL-CVD) trial participants were randomly assigned between September 23, 2008, and July 5, 2012, to 30 months of salsalate or placebo in addition to standard, guideline-based therapies. Randomization was computerized and centrally allocated, with patients, health care professionals, and researchers masked to treatment assignment. Participants were overweight and obese statin-using patients with established, stable coronary heart disease. INTERVENTIONS: Salsalate (3.5 g/d) or placebo orally over 30 months. MAIN OUTCOMES AND MEASURES: The primary outcome was progression of noncalcified coronary artery plaque assessed by multidetector computed tomographic angiography. Secondary outcomes were other measures of safety and efficacy. RESULTS: Two hundred fifty-seven participants were randomized to salsalate (n = 129) or placebo (n = 128). Their mean (SD) age was 60.8 (7.0) years, and 94.0% (236 of 251) were male. One hundred ninety participants (89 in the salsalate group and 101 in the placebo group) completed the study. Compared with baseline, there was no increase in noncalcified plaque volume in the placebo-treated patients and no difference in change between the salsalate and placebo groups (mean difference, -1 mm3; 95% CI, -11 to 9 mm3; P = .87). Salsalate treatment decreased total white blood cell, lymphocyte, monocyte, and neutrophil counts and increased adiponectin levels without change in C-reactive protein levels. Fasting glucose, triglycerides, uric acid, and bilirubin levels were decreased in the salsalate group compared with the placebo group, while hemoglobin levels were increased. Urinary albumin levels increased, with tinnitus and atrial arrhythmias more common, in the salsalate group compared with the placebo group. CONCLUSIONS AND RELEVANCE: Salsalate when added to current therapies that include a statin does not reduce progression of noncalcified coronary plaque volume assessed by multidetector computed tomographic angiography in statin-using patients with established, stable coronary heart disease. The absence of progression of noncalcified plaque volume in the placebo group may limit interpretation of the trial results. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00624923.
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Inflamación/tratamiento farmacológico , Obesidad , Sobrepeso , Placa Aterosclerótica/tratamiento farmacológico , Salicilatos/uso terapéutico , Anciano , Método Doble Ciego , Femenino , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Inflamación/complicaciones , Masculino , Persona de Mediana EdadRESUMEN
Obesity-induced inflammation mediated by immune cells in adipose tissue appears to participate in the pathogenesis of insulin resistance. We show that natural killer (NK) cells in adipose tissue play an important role. High-fat diet (HFD) increases NK cell numbers and the production of proinflammatory cytokines, notably TNFα, in epididymal, but not subcutaneous, fat depots. When NK cells were depleted either with neutralizing antibodies or genetic ablation in E4bp4(+/-) mice, obesity-induced insulin resistance improved in parallel with decreases in both adipose tissue macrophage (ATM) numbers, and ATM and adipose tissue inflammation. Conversely, expansion of NK cells following IL-15 administration or reconstitution of NK cells into E4bp4(-/-) mice increased both ATM numbers and adipose tissue inflammation and exacerbated HFD-induced insulin resistance. These results indicate that adipose NK cells control ATMs as an upstream regulator potentially by producing proinflammatory mediators, including TNFα, and thereby contribute to the development of obesity-induced insulin resistance.
Asunto(s)
Tejido Adiposo/patología , Inflamación/complicaciones , Resistencia a la Insulina , Células Asesinas Naturales/patología , Macrófagos/patología , Obesidad/complicaciones , Tejido Adiposo/inmunología , Animales , Células Cultivadas , Dieta Alta en Grasa/efectos adversos , Inflamación/inmunología , Inflamación/patología , Células Asesinas Naturales/inmunología , Macrófagos/inmunología , Ratones Endogámicos C57BL , Obesidad/inmunología , Obesidad/patologíaAsunto(s)
Antiinflamatorios no Esteroideos/farmacología , Remodelación Ósea/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Osteocalcina/efectos de los fármacos , Salicilatos/farmacología , Antiinflamatorios no Esteroideos/administración & dosificación , Biomarcadores/sangre , Humanos , Salicilatos/administración & dosificación , Resultado del TratamientoRESUMEN
OBJECTIVE: Diaphragmatic weakness and acute respiratory failure are common in sepsis. Nuclear factor-κB acts as a general coordinator of the systemic inflammatory response, but its role within the diaphragm itself during sepsis is unknown. We investigated the potential protective effect upon the diaphragm of inhibiting nuclear factor-κB only within muscle fibers during acute endotoxemia. DESIGN: Prospective study in experimental animals. SETTING: University research laboratory. INTERVENTIONS: Wild-type and transgenic (muscle-specific IκBα super-repressor) mice with skeletal muscle-specific inhibition of the classical nuclear factor-κB pathway were subjected to acute endotoxemia. Muscle-specific ubiquitin ligases (muscle RING-finger protein 1 and atrogin-1), caspase-3 activity, inhibitor of apoptosis proteins, proinflammatory cytokines (interleukin-1ß, monocyte chemoattractant protein-1, and tumor necrosis factor-α), and diaphragmatic contractility were evaluated after 24 hours. MEASUREMENTS AND MAIN RESULTS: In wild-type mice, endotoxemia significantly increased proinflammatory cytokines (fold-change messenger RNA: interleukin-1ß = 7.6, monocyte chemoattractant protein-1 = 15.3, and tumor necrosis factor-α = 2.2) and proteolysis effectors (fold-change messenger RNA: muscle RING-finger protein 1 = 5.7, atrogin-1 = 2.8; caspase-3 activity elevated by 28%) in the diaphragm, while reducing its force-generating capacity by 38%. In nonendotoxemic muscle-specific IκBα super-repressor diaphragms, caspase-3 activity was unexpectedly increased by 40% above basal wild-type levels and inhibitors of apoptosis proteins were down-regulated, but force production remained normal. In muscle-specific IκBα super-repressor mice subjected to endotoxemia, proinflammatory cytokines, muscle RING-finger protein 1, and atrogin-1 were not significantly increased above their basal levels, and diaphragmatic weakness and further increases in caspase-3 activity were completely prevented. CONCLUSIONS: These results suggest that nuclear factor-κB signaling within skeletal muscle fibers is a key pathway leading to diaphragmatic weakness during acute endotoxemia, most likely via effects on multiple inflammatory mediators. In addition, inhibition of nuclear factor-κB signaling within diaphragm muscle fibers has complex effects on caspase-3 activation, which could have implications for the treatment of sepsis-induced diaphragmatic dysfunction.
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Diafragma/metabolismo , Endotoxemia/fisiopatología , Inflamación/metabolismo , FN-kappa B/antagonistas & inhibidores , Animales , Apoptosis/fisiología , Caspasa 3/biosíntesis , Citocinas/biosíntesis , Ratones , Ratones Transgénicos , Contracción Muscular/fisiología , Fibras Musculares Esqueléticas , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Complementary surfaces are buried when peptide hormones, growth factors, or cytokines bind and activate cellular receptors. Although these extended surfaces provide high affinity and specificity to the interactions, they also present great challenges to the design of small molecules that might either mimic or antagonize the process. We show that the insulin receptor (IR) and downstream signals can be activated by targeting a site outside of its ligand-binding domain. A 24-residue peptide having the IR transmembrane (TM) domain sequence activates IR, but not related growth factor receptors, through specific interactions with the receptor TM domain. Like insulin-dependent activation, IR-TM requires that IR have a competent ATP-binding site and kinase activation loop. IR-TM also activates mutated receptors from patients with severe insulin resistance, which do not respond to insulin. These results show that IR can be activated through a pathway that bypasses its canonical ligand-binding domain.
Asunto(s)
Resistencia a la Insulina , Receptor de Insulina/metabolismo , Animales , Células CHO , Cricetinae , Cricetulus , Humanos , Ratones , Mutación , Células 3T3 NIH , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Receptor de Insulina/genéticaRESUMEN
OBJECTIVE Salsalate is a nonacetylated salicylate that lowers glucose levels in people with type 2 diabetes (T2D). Here we examined whether salsalate also lowered serum-protein-bound levels of early and advanced glycation end products (AGEs) that have been implicated in diabetic vascular complications. RESEARCH DESIGN AND METHODS Participants were from the Targeting Inflammation Using Salsalate for Type 2 Diabetes (TINSAL-T2D) study, which examined the impact of salsalate treatment on hemoglobin A1c (HbA1c) and a wide variety of other parameters. One hundred eighteen participants received salsalate, 3.5 g/day for 48 weeks, and 109 received placebo. Early glycation product levels (HbA1c and fructoselysine [measured as furosine]) and AGE levels (glyoxal and methylglyoxal hydroimidazolones [G-(1)H, MG-(1)H], carboxymethyllysine [CML], carboxyethyllysine [CEL], pentosidine) were measured in patient serum samples. RESULTS Forty-eight weeks of salsalate treatment lowered levels of HbA1c and serum furosine (P < 0.001) and CML compared with placebo. The AGEs CEL and G-(1)H and MG-(1)H levels were unchanged, whereas pentosidine levels increased more than twofold (P < 0.001). Among salsalate users, increases in adiponectin levels were associated with lower HbA1c levels during follow-up (P < 0.001). Changes in renal and inflammation factor levels were not associated with changes in levels of early or late glycation factors. Pentosidine level changes were unrelated to changes in levels of renal function, inflammation, or cytokines. CONCLUSIONS Salsalate therapy was associated with a reduction in early but not late glycation end products. There was a paradoxical increase in serum pentosidine levels suggestive of an increase in oxidative stress or decreased clearance of pentosidine precursor.
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Productos Finales de Glicación Avanzada/sangre , Salicilatos/uso terapéutico , Adiponectina/sangre , Adulto , Arginina/análogos & derivados , Arginina/sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Angiopatías Diabéticas/prevención & control , Femenino , Hemoglobina Glucada/análisis , Humanos , Lisina/análogos & derivados , Lisina/sangre , Masculino , Persona de Mediana Edad , Piruvaldehído/sangreRESUMEN
It is increasingly accepted that chronic inflammation participates in obesity-induced insulin resistance and type 2 diabetes (T2D). Salicylates and thiazolidinediones (TZDs) both have anti-inflammatory and anti-hyperglycemic properties. The present study compared the effects of these drugs on obesity-induced inflammation in adipose tissue (AT) and AT macrophages (ATMs), as well as the metabolic and immunological phenotypes of the animal models. Both drugs improved high fat diet (HFD)-induced insulin resistance. However, salicylates did not affect AT and ATM inflammation, whereas Pioglitazone improved these parameters. Interestingly, HFD and the drug treatments all modulated systemic inflammation as assessed by changes in circulating immune cell numbers and activation states. HFD increased the numbers of circulating white blood cells, neutrophils, and a pro-inflammatory monocyte subpopulation (Ly6C(hi)), whereas salicylates and Pioglitazone normalized these cell numbers. The drug treatments also decreased circulating lymphocyte numbers. These data suggest that obesity induces systemic inflammation by regulating circulating immune cell phenotypes and that anti-diabetic interventions suppress systemic inflammation by normalizing circulating immune phenotypes.
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Tejido Adiposo/patología , Dieta Alta en Grasa , Inflamación/tratamiento farmacológico , Inflamación/patología , Salicilatos/uso terapéutico , Tiazolidinedionas/uso terapéutico , Tejido Adiposo/efectos de los fármacos , Animales , Recuento de Células , Citometría de Flujo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Inflamación/genética , Resistencia a la Insulina , Activación de Macrófagos/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Familia de Multigenes , Obesidad/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Pioglitazona , Salicilatos/farmacología , Tiazolidinedionas/farmacologíaRESUMEN
The activation of the transcription factor NF-κB leads to changes in expression of many genes in pancreatic ß-cells. However, the role of NF-κB activation in islet transplantation has not been fully elucidated. The aim of the present study was to investigate whether the state of NF-κB activation would influence the outcome of islet transplantation. Transgenic mice expressing a dominant active IKKß (constitutively active) or a non-degradable form of IκBα (constitutive inhibition) under control of the rat insulin promoter were generated. Islets from these mice were transplanted into streptozotocin diabetic mice in suboptimal numbers. Further, the effects of salicylate (an inhibitor of NF-κB) treatment of normal islets prior to transplantation, and the effects of salicylate administration to mice prior to and after islet implantation were evaluated. Transplantation outcomes were not affected using islets expressing a non-degradable form of IκBα when compared to wild type controls. However, the transplantation outcomes using islets isolated from mice expressing a constitutively active mutant of NF-κB were marginally worse, although no aberrations of islet function in vitro could be detected. Salicylate treatment of normal islets or mice had no effect on transplantation outcome. The current study draws attention to the complexities of NF-κB in pancreatic beta cells by suggesting that they can adapt with normal or near normal function to both chronic activation and inhibition of this important transcription factor.
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Diabetes Mellitus Experimental/metabolismo , Quinasa I-kappa B/metabolismo , Células Secretoras de Insulina/metabolismo , Trasplante de Islotes Pancreáticos , FN-kappa B/metabolismo , Animales , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/terapia , Femenino , Regulación de la Expresión Génica , Quinasa I-kappa B/genética , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/patología , Masculino , Ratones , Ratones Transgénicos , FN-kappa B/genética , Regiones Promotoras Genéticas , Ratas , Ácido Salicílico/administración & dosificación , Estreptozocina , Resultado del TratamientoRESUMEN
OBJECTIVE: To test whether inhibiting inflammation with salsalate improves endothelial function in patients with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: We conducted an ancillary study to the National Institutes of Health-sponsored, multicenter, randomized, double-masked, placebo-controlled trial evaluating the safety and efficacy of salsalate in targeting inflammation to improve glycemia in patients with T2D. Flow-mediated, endothelium-dependent dilation (FMD) and endothelium-independent, nitroglycerin-mediated dilation (NMD) of the brachial artery were assessed at baseline and 3 and 6 months following randomization to either salsalate 3.5 g/day or placebo. The primary end point was change in FMD at 6 months. RESULTS: A total of 88 participants were enrolled in the study, and data after randomization were available for 75. Patients in the treatment and control groups had similar ages (56 years), BMI (33 kg/m(2)), sex (64% male), ethnicity, current treatment, and baseline HbA1c (7.7% [61 mmol/mol]). In patients treated with salsalate versus placebo, HbA1c was reduced by 0.46% (5.0 mmol/mol; P < 0.001), fasting glucose by 16.1 mg/dL (P < 0.001), and white blood cell count by 430 cells/µL (P < 0.02). There was no difference in the mean change in either FMD (0.70% [95% CI -0.86 to 2.25%]; P = 0.38) or NMD (-0.59% [95% CI -2.70 to 1.51%]; P = 0.57) between the groups treated with salsalate and placebo at 6 months. Total and LDL cholesterol were 11 and 16 mg/dL higher, respectively, and urinary albumin was 2.0 µg/mg creatinine higher in the patients treated with salsalate compared with those treated with placebo (all P < 0.009). CONCLUSIONS: Salsalate does not change FMD in peripheral conduit arteries in patients with T2D despite lowering HbA1c. This finding suggests that salsalate does not have an effect on vascular inflammation, inflammation does not cause endothelial dysfunction in T2D, or confounding effects of salsalate mitigate favorable effects on endothelial function.
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Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Endotelio Vascular/fisiopatología , Inflamación/tratamiento farmacológico , Salicilatos/administración & dosificación , Vasodilatación/efectos de los fármacos , Administración Oral , Adulto , Antiinflamatorios no Esteroideos/administración & dosificación , Arteria Braquial/diagnóstico por imagen , Arteria Braquial/efectos de los fármacos , Arteria Braquial/fisiopatología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Quimioterapia Combinada , Endotelio Vascular/diagnóstico por imagen , Endotelio Vascular/efectos de los fármacos , Femenino , Estudios de Seguimiento , Humanos , Hipoglucemiantes/uso terapéutico , Inflamación/etiología , Inflamación/metabolismo , Masculino , Persona de Mediana Edad , Flujo Sanguíneo Regional , Método Simple Ciego , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía , Vasodilatación/fisiologíaRESUMEN
Metabolic inflammation may contribute to the pathogenesis of obesity and its comorbidities, including type 2 diabetes and cardiovascular disease. Previously, we showed that the actin-binding protein profilin-1 (pfn) plays a role in atherogenesis because pfn heterozygote mice (PfnHet) exhibited a significant reduction in atherosclerotic lesion burden and vascular inflammation. In the current study, we tested whether pfn haploinsufficiency would also limit diet-induced adipose tissue inflammation and insulin resistance (IR). First, we found that a high-fat diet (HFD) upregulated pfn expression in epididymal and subcutaneous white adipose tissue (WAT) but not in the liver or muscle of C57BL/6 mice compared with normal chow. Pfn expression in WAT correlated with F4/80, an established marker for mature macrophages. Of note, HFD elevated pfn protein levels in both stromal vascular cells and adipocytes of WAT. We also found that PfnHet were significantly protected from HFD-induced glucose intolerance observed in pfn wild-type mice. With HFD, PfnHet displayed blunted expression of systemic and WAT proinflammatory cytokines and decreased accumulation of adipose tissue macrophages, which were also preferentially biased toward an M2-like phenotype; this correlated with preserved frequency of regulatory T cells. Taken together, the findings indicate that pfn haploinsufficiency protects against diet-induced IR and inflammation by modulating WAT immune homeostasis.
Asunto(s)
Tejido Adiposo Blanco/inmunología , Intolerancia a la Glucosa/genética , Haploinsuficiencia , Inflamación/inmunología , Profilinas/genética , Grasa Subcutánea/inmunología , Tejido Adiposo Blanco/patología , Animales , Antígenos de Diferenciación/biosíntesis , Dieta Alta en Grasa , Homeostasis , Resistencia a la Insulina/fisiología , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Obesidad/genética , Profilinas/biosíntesis , Factor de Transcripción STAT3/metabolismo , Grasa Subcutánea/metabolismoRESUMEN
BACKGROUND: Short-duration studies show that salsalate improves glycemia in type 2 diabetes mellitus (T2DM). OBJECTIVE: To assess 1-year efficacy and safety of salsalate in T2DM. DESIGN: Placebo-controlled, parallel trial; computerized randomization and centralized allocation, with patients, providers, and researchers blinded to assignment. (ClinicalTrials.gov: NCT00799643). SETTING: 3 private practices and 18 academic centers in the United States. PATIENTS: Persons aged 18 to 75 years with fasting glucose levels of 12.5 mmol/L or less (≤225 mg/dL) and hemoglobin A1c (HbA1c) levels of 7.0% to 9.5% who were treated for diabetes. INTERVENTION: 286 participants were randomly assigned (between January 2009 and July 2011) to 48 weeks of placebo (n = 140) or salsalate, 3.5 g/d (n = 146), in addition to current therapies, and 283 participants were analyzed (placebo, n = 137; salsalate, n = 146). MEASUREMENTS: Change in hemoglobin A1c level (primary outcome) and safety and efficacy measures. RESULTS: The mean HbA1c level over 48 weeks was 0.37% lower in the salsalate group than in the placebo group (95% CI, -0.53% to -0.21%; P < 0.001). Glycemia improved despite more reductions in concomitant diabetes medications in salsalate recipients than in placebo recipients. Lower circulating leukocyte, neutrophil, and lymphocyte counts show the anti-inflammatory effects of salsalate. Adiponectin and hematocrit levels increased more and fasting glucose, uric acid, and triglyceride levels decreased with salsalate, but weight and low-density lipoprotein cholesterol levels also increased. Urinary albumin levels increased but reversed on discontinuation; estimated glomerular filtration rates were unchanged. LIMITATION: Trial duration and number of patients studied were insufficient to determine long-term risk-benefit of salsalate in T2DM. CONCLUSION: Salsalate improves glycemia in patients with T2DM and decreases inflammatory mediators. Continued evaluation of mixed cardiorenal signals is warranted.