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The corticotropin-releasing hormone (CRH) and urocortins (UCNs) have been implicated in energy homeostasis and the cellular stress response. However, the expression of these neuropeptides in children remains unclear. Therefore, we determined the impact of obesity on their expression in 40 children who were normal weight, overweight, and had obesity. Peripheral blood mononuclear cells (PBMCs) and plasma were used to assess the expression of neuropeptides. THP1 cells were treated with 25 mM glucose and 200 µM palmitate, and gene expression was measured by real-time polymerase chain reaction (RT-PCR). Transcript levels of neuropeptides were decreased in PBMCs from children with increased body mass index as indicated by a significant decrease in UCN1, UCN3, and CRH mRNA in overweight and obese children. UCN3 mRNA expression was strongly correlated with UCN1, UCN2, and CRH. Exposure of THP1 cells to palmitate or a combination of high glucose and palmitate for 24 h increased CRH, UCN2, and UCN3 mRNA expression with concomitant increased levels of inflammatory and endoplasmic reticulum stress markers, suggesting a crosstalk between these neuropeptides and the cellular stress response. The differential impairment of the transcript levels of CRH and UCNs in PBMCs from overweight and obese children highlights their involvement in obesity-related metabolic and cellular stress.
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Obesidad Infantil , Urocortinas , Niño , Humanos , Leucocitos Mononucleares/metabolismo , Neuropéptidos/sangre , Sobrepeso , Obesidad Infantil/sangre , Urocortinas/sangreRESUMEN
OBJECTIVE: The corticotropin-releasing factor neuropeptides (corticotropin-releasing hormone [CRH] and urocortin [UCN]-1,2,3) and spexin contribute to the regulation of energy balance and inhibit food intake in mammals. However, the status of these neuropeptides in children with overweight has yet to be elucidated. This study investigated the effect of increased body weight on the circulating levels of these neuropeptides. METHODS: A total of 120 children with a mean age of 12 years were enrolled in the study. Blood samples were collected to assess the circulating levels of neuropeptides and were correlated with various anthropometric, clinical, and metabolic markers. RESULTS: Plasma levels of UCNs were altered in children with overweight but less so in those with obesity. Furthermore, the expression pattern of UCN1 was opposite to that of UCN2 and UCN3, which suggests a compensatory effect. However, no significant effect of overweight and obesity was observed on CRH and spexin levels. Finally, UCN3 independently associated with circulating zinc-alpha-2-glycoprotein and UCN2 levels, whereas UCN1 was strongly predicted by TNFα levels. CONCLUSIONS: Significant changes in neuropeptide levels were primarily observed in children with overweight and were attenuated with increased obesity. This suggests the presence of a compensatory mechanism for neuropeptides to curb the progression of obesity.
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Sobrepeso , Urocortinas , Animales , Niño , Humanos , Mamíferos/metabolismo , Obesidad , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Urocortinas/metabolismo , Urocortinas/farmacologíaRESUMEN
The neuropeptide urocortin 3 (UCN3) has a beneficial effect on metabolic disorders, such as obesity, diabetes, and cardiovascular disease. It has been reported that UCN3 regulates insulin secretion and is dysregulated with increasing severity of obesity and diabetes. However, its function in the adipose tissue is unclear. We investigated the overexpression of UCN3 in 3T3-L1 preadipocytes and differentiated adipocytes and its effects on heat shock response, ER stress, inflammatory markers, and glucose uptake in the presence of stress-inducing concentrations of palmitic acid (PA). UCN3 overexpression significantly downregulated heat shock proteins (HSP60, HSP72 and HSP90) and ER stress response markers (GRP78, PERK, ATF6, and IRE1α) and attenuated inflammation (TNFα) and apoptosis (CHOP). Moreover, enhanced glucose uptake was observed in both preadipocytes and mature adipocytes, which is associated with upregulated phosphorylation of AKT and ERK but reduced p-JNK. Moderate effects of UCN3 overexpression were also observed in the presence of 400 µM of PA, and macrophage conditioned medium dramatically decreased the UCN3 mRNA levels in differentiated 3T3-L1 cells. In conclusion, the beneficial effects of UCN3 in adipocytes are reflected, at least partially, by the improvement in cellular stress response and glucose uptake and attenuation of inflammation and apoptosis.
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Estrés del Retículo Endoplásmico , Urocortinas , Células 3T3-L1 , Adipocitos/metabolismo , Animales , Diferenciación Celular , Chaperón BiP del Retículo Endoplásmico , Endorribonucleasas/metabolismo , Resistencia a la Insulina , Ratones , Proteínas Serina-Treonina Quinasas/metabolismoRESUMEN
INTRODUCTION: Diabetic foot ulcers (DFU) and infection (DFI) are a major diabetes-related problem around the world due to the high prevalence of diabetes in the population. The aim of our study was to determine the microbiological profile of infected ulcers in patients attending Dasman Diabetes Institute (DDI) clinics in Kuwait and to analyze the distribution of microbial isolates according to wound grade, sex, age and diabetes control. METHODS: We collected and analyzed clinical data and samples from 513 diabetic patients with foot ulcers referred to our podiatry clinic at DDI from Jan 2011 till Dec 2017. RESULTS: We show a higher prevalence of DFU in men than in women, and a greater percentage of DFU occurred in men at an earlier age (p<0.05). Only about half of the DFU were clinically infected (49.3%) but 92% of DFU showed bacterial growth in the microbiological lab analysis. In addition, we isolated more monomicrobial (57.3%) than polymicrobial (34.8%) DFI and representing an average of 1.30 pathogens per patient. The presence of Gram-positive and Gram-negative strains was comparable between men and women regardless their age or glucose levels. Interestingly, more Gram-positive strains are present in ulcers without ischemia while more Gram-negative strains are present in ulcers with ischemia (p<0.05). While Staphylococcus aureus was common in infected ulcers without ischemia, Pseudomonas aeruginosa was predominant in ulcers with infection and ischemia, regardless of ulcer depth. Finally, a higher percentage of women has controlled HbA1c levels (19.41% versus 11.95% in men) and more women in this group displayed non-infected wounds (60.6% and 43.90% for women and men, respectively). CONCLUSION: Our results provide an updated picture of the DFI patterns and antibiotics resistance in patients attending Dasman Diabetes Institute (DDI) clinics in Kuwait which might help in adopting the appropriate treatment of infected foot and improving clinical outcomes.
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Pie Diabético/epidemiología , Pie Diabético/microbiología , Factores de Edad , Anciano , Antibacterianos/farmacología , Complicaciones de la Diabetes/epidemiología , Complicaciones de la Diabetes/microbiología , Diabetes Mellitus/epidemiología , Diabetes Mellitus/microbiología , Farmacorresistencia Microbiana/efectos de los fármacos , Femenino , Pie/microbiología , Úlcera del Pie/epidemiología , Úlcera del Pie/microbiología , Humanos , Kuwait/epidemiología , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Prevalencia , Pseudomonas aeruginosa/efectos de los fármacos , Factores Sexuales , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacosRESUMEN
BACKGROUND: Obstructive sleep apnea (OSA) is caused by partial or complete obstruction of the upper airways. Corrective surgeries aim at removing obstructions in the nasopharynx, oropharynx, and hypopharynx. OSA is associated with an increased risk of various metabolic diseases. Our objective was to evaluate the effect of surgery on the plasma metabolome. METHODS: This study included 39 OSA patients who underwent Multilevel Sleep Surgery (MLS). Clinical and anthropometric measures were taken at baseline and five months after surgery. RESULTS: The mean Apnea-Hypopnea Index (AHI) significantly dropped from 22.0 ± 18.5 events/hour to 8.97 ± 9.57 events/hour (p-Value < 0.001). Epworth's sleepiness Score (ESS) dropped from 12.8 ± 6.23 to 2.95 ± 2.40 (p-Value < 0.001), indicating the success of the surgery in treating OSA. Plasma levels of metabolites, phosphocholines (PC) PC.41.5, PC.42.3, ceremide (Cer) Cer.44.0, and triglyceride (TG) TG.53.6, TG.55.6 and TG.56.8 were decreased (p-Value < 0.05), whereas lysophosphatidylcholines (LPC) 20.0 and PC.39.3 were increased (p-Value < 0.05) after surgery. CONCLUSION: This study highlights the success of MLS in treating OSA. Treatment of OSA resulted in an improvement of the metabolic status that was characterized by decreased TG, PCs, and Cer metabolites after surgery, indicating that the success of the surgery positively impacted the metabolic status of these patients.
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Spexin is a novel neuropeptide playing an emerging role in metabolic diseases such as obesity and diabetes via involvement in energy homeostasis and food intake. The present study investigated the effects of obesity and type 2 diabetes (T2D) on circulating levels of spexin and its modulation by physical exercise. Normal-weight (n = 50) and obese adults with and without T2D (n = 69 and n = 66, respectively) were enrolled in the study. A subgroup of obese participants (n = 47) underwent a supervised 3-month exercise programme. Plasma spexin levels were measured by ELISA and correlated with various markers. Plasma spexin levels decreased in obese participants with or without T2D compared with those of normal-weight participants (0.43 ± 0.11, 0.44 ± 0.12 and 0.61 ± 0.23 ng/ml, respectively; P < 0.001). Spexin levels negatively correlated with adiposity markers and blood pressure in the whole study population (P < 0.05). Multiple regression analysis revealed blood pressure was the greatest predictive determinant of plasma spexin levels, which significantly increased in response to physical exercise in obese participants without and with T2D (P < 0.05). Spexin levels significantly increased only in responders to exercise (those with increased oxygen consumption, VO2 max) with a concomitant improvement in metabolic profile. In conclusion, plasma spexin levels may be an indicator of response to physical exercise.
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Diabetes Mellitus Tipo 2/terapia , Terapia por Ejercicio/métodos , Obesidad/terapia , Hormonas Peptídicas/sangre , Adulto , Biomarcadores/sangre , Diabetes Mellitus Tipo 2/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/sangre , Consumo de OxígenoRESUMEN
Lipotoxicity, an important factor in the pathogenesis of diabetes, leads to defective ß-cell proliferation and increased apoptosis. Glucagon-like peptide-1 (GLP-1) analogs, which are used to treat type 2 diabetes, reduce endoplasmic reticulum stress and inflammation in pancreatic ß-cells and improve their survival. However, their effects on the heat shock response (HSR) have not been elucidated yet. We investigated whether the GLP-1 analog exendin-4 exerts its protective effect by modulating the HSR and mitogen-activated protein kinases (MAPKs) in BTC-6 mouse pancreatic cells under palmitic acid (PA) stress. Expression patterns were analyzed using mass spectrometry, Western blotting, and qRT-PCR in the presence of 250 or 400 µM PA and 100 nM exendin-4. Additionally, we measured MAPK expression and phosphorylation using qRT-PCR and Western blotting, respectively. Upregulation of heat shock protein (HSP), notably HSP72, in the presence of PA, was attenuated by exendin-4. Despite the absence of global effects on the HSR system, exendin-4 attenuated the expression of other non-classical HSPs (GRP94, DNAJA1, and DNAJB6) in the presence of PA. Regarding MAPKs, only extracellular signal-regulated kinase (ERK) phosphorylation was highly increased by exendin-4 in both the presence and absence of PA. Furthermore, exendin-4 significantly alleviated PA-induced cell death, which was further confirmed with proteomics analysis where key cellular functions, including cellular growth, assembly, and organization, were improved by exendin-4 treatment. Thus, our results expand the protective role of GLP-1 analogs to include other cellular mechanisms involved in restoring normal ß-cell homeostasis.
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Exenatida/metabolismo , Péptido 1 Similar al Glucagón/análogos & derivados , Proteínas del Choque Térmico HSP72/metabolismo , Células Secretoras de Insulina/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Diabetes Mellitus Tipo 2/metabolismo , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Exenatida/farmacología , Proteínas del Choque Térmico HSP40 , Glicoproteínas de Membrana , Ratones , Chaperonas Moleculares , Fosforilación , Sustancias Protectoras/farmacología , Mapas de Interacción de Proteínas , Regulación hacia ArribaRESUMEN
Epoxide hydrolase 2 (EPHX2) is an emerging therapeutic target in several immunometabolic disorders. EPHX2 metabolizes anti-inflammatory epoxyeicosatrienoic acids into pro-inflammatory diols. The contribution of EPHX2 activity to human obesity remains unexplored. We compared the expression of EPHX2 between lean and obese humans (n = 20 each) in subcutaneous adipose tissue (SAT) and peripheral blood mononuclear cells (PBMCs) using RT-PCR, Western Blot analysis, immunohistochemistry, and confocal microscopy before and after a 3-month physical activity regimen. We also assessed EPHX2 levels during preadipocyte differentiation in humans and mice. EPHX2 mRNA and protein expression were significantly elevated in obese subjects, with concomitant elevated endoplasmic reticulum (ER) stress components (the 78-kDa glucose-regulated protein; GRP78, and the Activating transcription factor 6; ATF6) and inflammatory markers (Tumor necrosis factor-α; TNFα, and Interleukin 6; IL6) as compared to controls (p < 0.05). EPHX2 mRNA levels strongly correlated with adiposity markers. In obese individuals, physical activity attenuated EPHX2 expression levels in both the SAT and PBMCs, with a parallel decrease in ER stress and inflammation markers. EPHX2 expression was also elevated during differentiation of both human primary and 3T3-L1 mouse preadipocytes. Mediators of cellular stress (palmitate, homocysteine, and macrophage culture medium) also increased EPHX2 expression in 3T3-L1 preadipocytes. Our findings suggest that EPHX2 upregulation is linked to ER stress in adiposity and that physical activity may attenuate metabolic stress by reducing EPHX2 expression.
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Epóxido Hidrolasas/genética , Ejercicio Físico , Regulación de la Expresión Génica , Obesidad/genética , Obesidad/metabolismo , Adulto , Biomarcadores , Pesos y Medidas Corporales , Chaperón BiP del Retículo Endoplásmico , Epóxido Hidrolasas/metabolismo , Femenino , Humanos , Leucocitos Mononucleares/metabolismo , Masculino , Persona de Mediana Edad , ARN Mensajero/genética , ARN Mensajero/metabolismo , Grasa Subcutánea/metabolismoRESUMEN
Fetuin-A (Fet-A) was one of the first hepatokines to be reportedly linked to metabolic diseases. Fet-A was also suggested to be an adipokine, but its expression in the adipose tissue remains debatable. Here we compared the expression of Fet-A between human and mice adipose tissue biopsies as well as among human subcutaneous tissue and visceral adipose tissue primary cells, and mouse 3 T3-L1 cells at various stages of differentiation. Fet-A was expressed in mice biopsies and cells but not in human biopsies and cells, except in visceral adipose tissue primary cells following differentiation. Although the marginal expression of Fet-A in human visceral adipose tissue, a major contribution of Fet-A expression in human adipose tissue to systemic Fet-A levels is discounted, but it could indicate specific local Fet-A action in the visceral adipose tissue.
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Tejido Adiposo/citología , alfa-2-Glicoproteína-HS/metabolismo , Animales , Células Cultivadas , Humanos , Grasa Intraabdominal/citología , Grasa Intraabdominal/metabolismo , Ratones , Tejido Subcutáneo/metabolismo , alfa-2-Glicoproteína-HS/genéticaRESUMEN
Cardiovascular disease (CVD) risks persist in patients despite treatment. CVD susceptibility also varies with sex and ethnicity and is not entirely explained by conventional CVD risk factors. The aim of the present study was to identify novel CVD candidate markers in circulating Peripheral blood mononuclear cells (PBMCs) and plasma from Arab obese subjects with and without CVD using proteomic approaches. Human adults with confirmed CVD (n = 208) and matched non-CVD controls (n = 152) living in Kuwait were examined in the present cross-sectional study. Anthropometric and classical biochemical parameters were determined. We employed a shotgun proteomic profiling approach on PBMCs isolated from a subset of the groups (n = 4, each), and differentially expressed proteins selected between the two groups were validated at the mRNA level using RT-PCR (n = 6, each). Plasma levels of selected proteins from the proteomics profiling: Proteinase-3 (PR3), Annexin-A3 (ANX3), Defensin (DEFA1), and Matrix Metalloproteinase-9 (MMP9), were measured in the entire cohort using human enzyme-linked immunosorbent assay kits and were subsequently correlated with various clinical parameters. Out of the 1407 we identified and quantified from the proteomics profiling, 47 proteins were dysregulated with at least twofold change between the two subject groups. Among the differentially expressed proteins, 11 were confirmed at the mRNA levels. CVD influenced the levels of the shortlisted proteins (MMP9, PR3, ANX3, and DEFA1) in the PBMCs and plasma differentially. Despite the decreased levels of both protein and mRNA in PBMCs, PR3 circulating levels increased significantly in patients with CVD and were influenced by neither diabetes nor statin treatment. No significant changes were; however, observed in the DEFA1, MMP9, and ANX3 levels in plasma. Multivariate logistic regression analysis revealed that only PR3 was independently associated with CVD. Our results suggest that the dysregulation of PR3 levels in plasma and PBMCs reflects underlying residual CVD risks even in the treated population. More prospective and larger studies are required to establish the role of PR3 in CVD progression.
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Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/metabolismo , Mieloblastina/metabolismo , Adulto , Anexina A3/análisis , Anexina A3/sangre , Anexina A3/metabolismo , Árabes , Estudios Transversales , Defensinas/análisis , Defensinas/sangre , Defensinas/metabolismo , Femenino , Perfilación de la Expresión Génica , Humanos , Kuwait/epidemiología , Leucocitos/metabolismo , Leucocitos Mononucleares/metabolismo , Masculino , Metaloproteinasa 9 de la Matriz/análisis , Metaloproteinasa 9 de la Matriz/sangre , Metaloproteinasa 9 de la Matriz/metabolismo , Persona de Mediana Edad , Mieloblastina/análisis , Mieloblastina/sangre , Plasma/metabolismo , Estudios Prospectivos , Proteómica , ARN Mensajero/genéticaRESUMEN
Urocortin3 (UCN3) regulates metabolic functions and is involved in cellular stress response. Although UCN3 is expressed in human adipose tissue, the association of UCN3 with obesity and diabetes remains unclear. This study investigated the effects of Type 2 diabetes (T2D) and increased body weight on the circulatory and subcutaneous adipose tissue (SAT) levels of UCN3 and assessed UCN3 modulation by a regular physical exercise. Normal-weight (n = 37) and overweight adults with and without T2D (n = 98 and n = 107, respectively) were enrolled in the study. A subset of the overweight subjects (n = 39 for each group) underwent a supervised 3-month exercise program combining both moderate intensity aerobic exercise and resistance training with treadmill. UCN3 levels in SAT were measured by immunofluorescence and RT-PCR. Circulatory UCN3 in plasma was assessed by ELISA and was correlated with various clinical and metabolic markers. Our data revealed that plasma UCN3 levels decreased in overweight subjects without T2D compared with normal-weight controls [median; 11.99 (0.78-86.07) and 6.27 (0.64-77.04), respectively; p < 0.001], whereas plasma UCN3 levels increased with concomitant T2D [median; 9.03 (0.77-104.92) p < 0.001]. UCN3 plasma levels were independently associated with glycemic index; fasting plasma glucose and hemoglobin A1c (r = 0.16 and r = 0.20, p < 0.05, respectively) and were significantly different between both overweight, with and without T2D, and normal-weight individuals (OR = 2.11 [1.84-4.11, 95% CI] and OR = 2.12 [1.59-3.10, 95% CI], p < 0.01, respectively). Conversely, the UCN3 patterns observed in SAT were opposite to those in circulation; UCN3 levels were significantly increased with body weight and decreased with T2D. After a 3-month supervised exercise protocol, UCN3 expression showed a significant reduction in SAT of both overweight groups (2.3 and 1.6-fold change; p < 0.01, respectively). In conclusion, UCN levels are differentially dysregulated in obesity in a tissue-dependent manner and can be mitigated by regular moderate physical exercise.
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Despite reports on the occurrence of Granulicatella adiacens in infective endocarditis, few mechanistic studies on its virulence characteristics or pathogenicity are available. Proteins secreted by this species may act as determinants of host-microbe interaction and play a role in virulence. Our aim in this study was to investigate and functionally characterize the secretome of G. adiacens. Proteins in the secretome preparation were digested by trypsin and applied to nanoLC-ESI-MS/MS. By using a combined mass spectrometry and bioinformatics approach, we identified 101 proteins. Bioinformatics tools predicting subcellular localization revealed that 18 of the secreted proteins possessed signal sequence. More than 20% of the secretome proteins were putative virulence proteins including serine protease, superoxide dismutase, aminopeptidase, molecular chaperone DnaK, and thioredoxin. Ribosomal proteins, molecular chaperones, and glycolytic enzymes, together known as "moonlighting proteins," comprised fifth of the secretome proteins. By Gene Ontology analysis, more than 60 proteins of the secretome were grouped in biological processes or molecular functions. KEGG pathway analysis disclosed that the secretome consisted of enzymes involved in biosynthesis of antibiotics. Cytokine profiling revealed that secreted proteins stimulated key cytokines, such as IL-1ß, MCP-1, TNF-α, and RANTES from human PBMCs. In summary, the results from the current investigation of the G. adiacens secretome provide a basis for understanding possible pathogenic mechanisms of G. adiacens.
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Proteínas Bacterianas/análisis , Carnobacteriaceae/química , Carnobacteriaceae/patogenicidad , Factores de Virulencia/análisis , Carnobacteriaceae/aislamiento & purificación , Biología Computacional , Endocarditis/microbiología , Humanos , Proteómica , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en TándemRESUMEN
BACKGROUND: The hepatokine fetuin-A is linked to obesity and type 2 diabetes, but its presence and expression in adipose tissue remain unclear. In this study, we aimed to assess the circulating levels of fetuin-A and its expression in subcutaneous adipose tissue (SAT) from diabetic and non-diabetic obese subjects and their modulation by exercise. METHODS: SAT and blood were obtained from adults obese (diabetic, n=118 and non-diabetic, n=166) before and after a 3-month exercise program (diabetic, n=40 and non-diabetic, n=36, respectively). Plasma fetuin-A was assayed using ELISA. The presence and expression of fetuin-A in SAT, peripheral blood mononuclear cells (PBMCs) and cell lines (3T3-L1, THP-1, HepG2, RAW 264.7) were analysed using confocal microscopy, immunoblotting and qRT-PCR. RESULTS: Plasma fetuin-A level did not significantly differ between diabetic and non-diabetic obese subjects. However, when the non-diabetic group was divided into metabolically healthy and unhealthy phenotypes, significantly higher fetuin-A level was observed in the unhealthy sub-group. Circulating fetuin-A was mainly associated with glycaemic markers. In SAT, fetuin-A protein level was significantly higher in the diabetic obese subjects but its mRNA was not detected. Similarly, fetuin-A protein was detected in PBMCs, but its mRNA was not. In line with this, the use of various cell lines and culture media indicated that the presence of fetuin-A in SAT and PBMCs was due to its uptake from circulation rather than its endogenous expression. Finally, physical exercise decreased fetuin-A levels in both plasma and SAT in both groups. CONCLUSIONS: Fetuin-A levels increased in association with diabetes in SAT but not in circulation in the obese subjects. Moreover, physical exercise decreased fetuin-A level. Fetuin-A potentially acts as a hepatokine taken up by other tissues, such as adipose tissue.
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Diabetes Mellitus Tipo 2/metabolismo , Leucocitos Mononucleares/metabolismo , Obesidad/metabolismo , Grasa Subcutánea/metabolismo , alfa-2-Glicoproteína-HS/genética , Adulto , Animales , Línea Celular , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Ejercicio Físico , Femenino , Regulación de la Expresión Génica , Humanos , Masculino , Ratones , Persona de Mediana Edad , Obesidad/sangre , Obesidad/complicaciones , alfa-2-Glicoproteína-HS/análisisRESUMEN
The chemokine CCL2 (also known as MCP-1) is a key regulator of monocyte infiltration into adipose tissue, which plays a central role in the pathophysiology of obesity-associated inflammation and insulin resistance. It remains unclear how CCL2 production is upregulated in obese humans and rodents. Because elevated levels of the free fatty acid (FFA) palmitate and TNF-α have been reported in obesity, we studied whether these agents interact to trigger CCL2 production. Our data show that treatment of THP-1 and primary human monocytic cells with palmitate and TNF-α led to a marked increase in CCL2 production compared with either treatment alone. Mechanistically, we found that cooperative production of CCL2 by palmitate and TNF-α did not require MyD88, but it was attenuated by blocking TLR4 or TRIF. IRF3-deficient cells did not show synergistic CCL2 production in response to palmitate/TNF-α. Moreover, IRF3 activation by polyinosinic-polycytidylic acid augmented TNF-α-induced CCL2 secretion. Interestingly, elevated NF-κB/AP-1 activity resulting from palmitate/TNF-α costimulation was attenuated by TRIF/IRF3 inhibition. Diet-induced C57BL/6 obese mice with high FFAs levels showed a strong correlation between TNF-α and CCL2 in plasma and adipose tissue and, as expected, also showed increased adipose tissue macrophage accumulation compared with lean mice. Similar results were observed in the adipose tissue samples from obese humans. Overall, our findings support a model in which elevated FFAs in obesity create a milieu for TNF-α to trigger CCL2 production via the TLR4/TRIF/IRF3 signaling cascade, representing a potential contribution of FFAs to metabolic inflammation.
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Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Quimiocina CCL2/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Factor 3 Regulador del Interferón/metabolismo , Palmitatos/farmacología , Factor de Necrosis Tumoral alfa/farmacología , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Línea Celular , Humanos , Resistencia a la Insulina/fisiología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Factor 88 de Diferenciación Mieloide/metabolismo , FN-kappa B/metabolismo , Transducción de Señal/efectos de los fármacos , Receptor Toll-Like 4/metabolismoRESUMEN
Heat shock protein 60 (HSP60) is a key protein in the crosstalk between cellular stress and inflammation. However, the status of HSP60 in diabetes and obesity is unclear. In the present study, we investigated the hypothesis that HSP60 expression levels in the adipose tissue of human obese adults with and without diabetes are different and physical exercise might affect these levels. Subcutaneous adipose tissue (SAT) and blood samples were collected from obese adults with and without diabetes (n = 138 and n = 92, respectively, at baseline; n = 43 for both groups after 3 months of physical exercise). Conventional RT-PCR, immunohistochemistry, immunofluorescence, and ELISA were used to assess the expression and secretion of HSP60. Compared with obese adults without diabetes, HSP60 mRNA and protein levels were decreased in SAT in diabetic obese together with increased inflammatory marker expression and glycemic levels but lower VO2 Max. More interestingly, a 3-month physical exercise differentially affected HSP60 expression and the heat shock response but attenuated inflammation in both groups, as reflected by decreased endogenous levels of IL-6 and TNF-α. Indeed, HSP60 expression levels in SAT were significantly increased by exercise in the diabetes group, whereas they were decreased in the non-diabetes group. These results were further confirmed using immunofluorescence microscopy and anti-HSP60 antibody in SAT. Exercise had only marginal effects on HSP60 secretion and HSP60 autoantibody levels in plasma in both obese with and without diabetes. Physical exercise differentially alleviates cellular stress in obese adults with and without diabetes despite concomitant attenuation of the inflammatory response.
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BACKGROUND: Cardiovascular disease (CVD) risks persist in patients despite the use of conventional treatments. This might be due to chronic inflammation as reflected in epidemiological studies associating circulating low-grade inflammatory markers with CVD recurrent events. Here, we explored this potential link by assessing plasma dual-specificity phosphatase 1 (DUSP1) levels and comparing them to high-sensitivity CRP (hsCRP) and oxidized low-density lipoprotein (oxLDL) levels and their associations to conventional CVD risk factors in confirmed CVD patients. METHODS: Human adults with reported CVD (n = 207) and controls (n = 70) living in Kuwait were used in this study. Anthropometric and classical biochemical parameters were determined. Plasma levels of DUSP1, oxLDL, and hsCRP were measured using human enzyme-linked immunosorbent assay kits. RESULTS: DUSP1 and hsCRP plasma levels and their least square means were higher in CVD cases, while oxLDL plasma levels were lower (p < 0.05). Multivariate logistic regression analysis showed that DUSP1 and hsCRP are independently associated with CVD in the studied population, as reflected by 2-fold and 1.5-fold increased risks with increased levels of DUSP1 and hsCRP, respectively. In our study, DUSP1 levels were found to be associated with CVD despite statin treatment and diabetes status (p < 0.05), whereas hsCRP mainly correlated with obesity markers. CONCLUSIONS: Circulating DUSP1 might be a predictor of chronic subclinical inflammation and residual risk in CVD patients, whereas our data suggest that the association between hsCRP and CVD is largely accounted for adiposity risk factors.
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Biomarcadores/sangre , Enfermedades Cardiovasculares/metabolismo , Fosfatasa 1 de Especificidad Dual/sangre , Adulto , Anciano , Árabes , Proteína C-Reactiva/metabolismo , Enfermedades Cardiovasculares/sangre , Estudios de Casos y Controles , Femenino , Humanos , Kuwait , Lipoproteínas LDL/sangre , Modelos Logísticos , Masculino , Persona de Mediana EdadRESUMEN
PURPOSE: Glucagon-like peptide-1 (GLP-1) analogues reduce ER stress and inflammation in key metabolic organs, including the liver. However, their effects on heat shock response (HSR) and mitogen-activated protein kinases (MAPKs) have not yet been elucidated. In the present study, we investigate whether the GLP-1 analogue, exendin-4, triggers the expression of HSR and increases MAPK activity under metabolic stress. EXPERIMENTAL DESIGN: The effects of exendin-4 in the presence or absence of palmitic acid (PA; 400 µm) or glucose (30 mm) in the HepG2 liver cell line are assessed using Western blots, quantitative real-time PCR, and label-free proteomics. RESULTS: Heat shock proteins (HSP60, HSP72, HSP90, and GRP78) and other chaperones are not significantly affected by exendin-4 under the conditions tested. In contrast, the presence of exendin-4 alone increases the MAPK phosphorylation levels (JNK, ERK1/2, and p38). For short incubation periods, in the presence of PA or glucose, treatment with exendin-4 exhibits limited effects but significantly attenuates MAPK phosphorylation after a 24-h incubation. Interestingly, canonical signaling pathways, such as EIF2, ILK, PKA, and Rho, are modulated by exendin-4. CONCLUSION AND CLINICAL RELEVANCE: Identifying new pathways modulated by GLP-1 analogues will provide further insights into their benefits beyond their currently recognized roles in glycemic control, such as MAPK activity, energy homeostasis, and body weight decrease.
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Exenatida/farmacología , MAP Quinasa Quinasa 4/genética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Supervivencia Celular/efectos de los fármacos , Cromatografía Liquida , Chaperón BiP del Retículo Endoplásmico , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Respuesta al Choque Térmico/efectos de los fármacos , Respuesta al Choque Térmico/genética , Células Hep G2 , Humanos , MAP Quinasa Quinasa 4/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Fosforilación/efectos de los fármacos , Espectrometría de Masas en Tándem , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Functional foods contain biologically active ingredients associated with physiological health benefits for preventing and managing chronic diseases, such as type 2 diabetes mellitus (T2DM). A regular consumption of functional foods may be associated with enhanced anti-oxidant, anti-inflammatory, insulin sensitivity, and anti-cholesterol functions, which are considered integral to prevent and manage T2DM. Components of the Mediterranean diet (MD)-such as fruits, vegetables, oily fish, olive oil, and tree nuts-serve as a model for functional foods based on their natural contents of nutraceuticals, including polyphenols, terpenoids, flavonoids, alkaloids, sterols, pigments, and unsaturated fatty acids. Polyphenols within MD and polyphenol-rich herbs-such as coffee, green tea, black tea, and yerba maté-have shown clinically-meaningful benefits on metabolic and microvascular activities, cholesterol and fasting glucose lowering, and anti-inflammation and anti-oxidation in high-risk and T2DM patients. However, combining exercise with functional food consumption can trigger and augment several metabolic and cardiovascular protective benefits, but it is under-investigated in people with T2DM and bariatric surgery patients. Detecting functional food benefits can now rely on an "omics" biological profiling of individuals' molecular, genetics, transcriptomics, proteomics, and metabolomics, but is under-investigated in multi-component interventions. A personalized approach for preventing and managing T2DM should consider biological and behavioral models, and embed nutrition education as part of lifestyle diabetes prevention studies. Functional foods may provide additional benefits in such an approach.
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Diabetes Mellitus Tipo 2/prevención & control , Alimentos Funcionales , Estilo de Vida , Dieta Mediterránea , HumanosRESUMEN
OBJECTIVE: ANGPTL7 is a member of the Angiopoietin-like (ANGPTL) protein family that is composed of eight proteins (1-8). Increasing evidence is associating ANGPTL proteins to obesity and insulin resistance. The biological role of ANGPTL7 is yet to be understood except for a recently proposed role in the pathophysiology of glaucoma. This study was designed to shed light on the function of ANGPTL7 in obesity and its modulation by physical exercise as well as its potential association with lipid profile. METHODS: A total of 144 subjects were enrolled in this study and finished three months of physical exercise. The participants were classified based on their BMI, 82 subjects were non-obese and 62 obese. ANGPTL7 levels in plasma and adipose tissue were measured by ELISA, RT-PCR and immunohistochemistry. RESULTS: In this study, we showed that ANGPTL7 level was increased in the plasma of obese subjects (1249.05± 130.39 pg/mL) as compared to non-obese (930.34 ± 87.27 pg/mL) (p-Value = 0.032). ANGPTL7 Gene and protein expression levels in adipose tissue also showed over two fold increase. Physical exercise reduced circulating level of ANGPTL7 in the obese subjects to 740.98± 127.18 pg/mL, (p-Value = 0.007). ANGPTL7 expression in adipose tissue was also reduced after exercise. Finally, ANGPTL7 circulating level showed significant association with TG level in the obese subjects (R2 = 0.183, p-Value = 0.03). CONCLUSION: In conclusion, our data shows for the first time that obesity increases the level of ANGPTL7 in both plasma and adipose tissue. Increased expression of ANGPTL7 might play a minor role in the regulation of TG level in obese subjects either directly or through interaction with other ANGPTL protein members. Physical exercise reduced the level of ANGPTL7 highlighting the potential for targeting this protein as a therapeutic target for regulating dyslipidemia.
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Tejido Adiposo/metabolismo , Angiopoyetinas/metabolismo , Ejercicio Físico , Obesidad/metabolismo , Adulto , Proteína 7 Similar a la Angiopoyetina , Proteínas Similares a la Angiopoyetina , Angiopoyetinas/sangre , Biomarcadores , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/tratamiento farmacológico , Palmitatos/farmacología , Palmitatos/uso terapéuticoRESUMEN
BACKGROUND AND OBJECTIVES: Perturbation of the endoplasmic reticulum (ER) homeostasis has emerged as one of the prominent features of obesity and diabetes. This occurs when the adaptive unfolded protein response (UPR) fails to restore ER function in key metabolic tissues. We previously reported increased inflammation and impaired heat shock response (HSR) in obese human subjects that were restored by physical exercise. Here, we investigated the status of ER stress chaperone; glucose-regulated protein 78 (GRP78) and its downstream UPR pathways in human obese, and their modulation by a supervised 3-month physical exercise. METHODS: Subcutaneous adipose tissue (SAT) and blood samples were collected from non-diabetic adult human lean (n=40) and obese (n=40, at baseline and after 3months of physical exercise). Transcriptomic profiling was used as a primary screen to identify differentially expressed genes and it was carried out on SAT samples using the UPR RT(2) Profiler PCR Array. Conventional RT-PCR, immunohistochemistry, immunofluorescence, Western blot and ELISA were used to validate the transcriptomic data. Correlation analyses with the physical, clinical and biochemical outcomes were performed using Pearson's rank correlation coefficient. RESULTS: Levels of GRP78 and its three downstream UPR arms; activating transcription factor-6 (ATF6), inositol-requiring enzyme-1α (IRE1α) and protein kinase RNA-like endoplasmic reticulum kinase (PERK) were increased in obese subjects. More interestingly, higher levels of circulating GRP78 protein were found in obese compared to lean subjects which correlated negatively with maximum oxygen uptake (VO2 Max) but positively with high-sensitivity C-reactive protein (hsCRP) and obesity indicators such as BMI, percentage body fat (PBF) and waist circumference. GRP78 increased secretion in obese was further confirmed in vitro using 3T3-L1 preadipocyte cells under ER stress. Finally, we showed that physical exercise significantly attenuated the expression and release of GRP78 with a concomitant reduction in the phosphorylation of IRE1α and eukaryotic initiation factor-2α (eIF2α). CONCLUSION: Our results suggest that physical exercise alleviates ER stress in human obese through attenuation of GRP78 signaling network.