Molecular pathways involved in metabolic control of CCL5 in adipocytes

2012 - 2013Obesity is a chronic disorder characterized by a tonic low-grade activation of the innate immune system that affects steady-state measures of metabolic homeostasis over time. In addition, obesity is often accompanied by elevations in tissue and circulating FFA concentrations. Systemic levels of FFAs can induce inflammatory cascades in adipocytes and macrophages through TLR4-dependent effect. Signaling through TLR4 activates a broad range of intracellular cascades that include stimulation of IKK-β, NF-kB, JNK and AP1. Indeed, in addition to store excess calories in the form of lipid, adipose tissue produces classical cytokines and chemokines such as MCP-1, IL-8 and CCL5. CCL5, as other chemokines, participates in mediating leukocyte infiltration of adipose tissue. Moreover circulating CCL5 concentrations are elevated in obesity, impaired glucose tolerance (IGT) and type 2 diabetes. In this study I have investigated the molecular mechanisms involved in the metabolic control of CCL5 expression in adipocytes. Cytokine/growth factor screening of conditioned media from 3T3-L1 preadipocytes and adipocytes revealed that adipocytes secreted higher amount of CCL5 compared to their undifferentiated precursors. Higher concentrations of glucose and fatty acids (oleate and palmitate) increased CCL5 secretion by 3T3-L1 adipocytes. Moreover, both oleate and palmitate enhanced CCL5 mRNA levels and induced an activation of JNK, NF-kB, MAPK and PI3K/AKT pathways. In cells treated with JSH23, a NF-kB inhibitor, the effect of FFAs on CCL5 mRNA levels was reduced thus indicating a direct involvement of NF-kB. Treatment of the cells with SP600125, a JNK inhibitor, also significantly reduced the stimulatory effect of oleate and palmitate on CCL5 mRNA and interestingly prevented FFA-induced NF-kB binding to CCL5 promoter. I have also obtained evidence that insulin exerted an inhibitory effect on CCL5 mRNA and counteracted fatty acid-induced stimulation. Both PD98059 and LY294002, inhibitors of MAPK and PI3K, respectively, increased CCL5 expression levels reverted anti-inflammatory effect of insulin in presence of fatty acids. Consistently, insulin exposure reduced NF-kB recruitment onto CCL5 promoter, and almost completely prevented fatty acid effect. In conclusion, oleate and palmitate induce CCL5 mRNA, possibly via JNK and NF-kB pathways. Fatty acid effect on CCL5 is largely prevented by insulin and may involve PI3K/AKT and MAPK. [edited by author]XII n.s

Serum 25-Hydroxyvitamin D Levels, phosphoprotein enriched in diabetes gene product (PED/PEA-15) and leptin-to-adiponectin ratio in women with PCOS

<p>Abstract</p> <p>Background</p> <p>Polycystic ovary syndrome (PCOS) is frequently associated with hypovitaminosis D. Vitamin D is endowed with pleiotropic effects, including insulin resistance (IR) and apoptotic pathway. Disruption of the complex mechanism that regulated ovarian apoptosis has been reported in PCOS. Phosphoprotein enriched in diabetes gene product (PED/PEA-15), an anti-apoptotic protein involved in type 2 diabetes mellitus (T2DM), is overexpressed in PCOS women, independently of obesity. Leptin-to-adiponectin ratio (L/A) is a biomarker of IR and low-grade inflammation in PCOS. The aim of the study was to investigate the levels of 25-hydroxy vitamin D (25(OH)D), and L/A, in association with PED/PEA-15 protein abundance, in both lean and overweight/obese (o/o) women with PCOS.</p> <p>Patients and Methods</p> <p>PED/PEA-15 protein abundance and circulating levels of 25(OH)D, L/A, sex hormone-binding globulin, and testosterone were evaluated in 90 untreated PCOS patients (25 ± 4 yrs; range 18-34) and 40 healthy controls age and BMI comparable, from the same geographical area. FAI (free androgen index) and the homeostasis model assessment of insulin resistance (HoMA-IR) index were calculated.</p> <p>Results</p> <p>In o/o PCOS, 25(OH)D levels were significantly lower, and L/A values were significantly higher than in lean PCOS (p < 0.001), while there were no differences in PED/PEA-15 protein abundance. An inverse correlation was observed between 25(OH)D and BMI, PED/PEA-15 protein abundance, insulin, HoMA-IR, FAI (p < 0.001), and L/A (p < 0.05). At the multivariate analysis, in o/o PCOS L/A, insulin and 25(OH)D were the major determinant of PED/PEA-15 protein abundance (β = 0.45, β = 0.41, and β = -0.25, respectively).</p> <p>Conclusions</p> <p>Lower 25(OH)D and higher L/A were associated to PED/PEA-15 protein abundance in PCOS, suggesting their involvement in the ovarian imbalance between pro-and anti-apoptotic mechanisms, with high L/A and insulin and low 25(OH)D levels as the main determinants of PED/PEA-15 protein variability. Further studies, involving also different apoptotic pathways or inflammatory cytokines and granulosa cells are mandatory to better define the possible bidirectional relationships between 25(OH)D, PED/PEA-15 protein abundance, leptin and adiponectin in PCOS pathogenesis.</p

Epicardial adipose tissue has an increased thickness and is a source of inflammatory mediators in patients with calcific aortic stenosis

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Diagnostic and Prognostic Value of Conventional Brain MRI in the Clinical Work-Up of Patients with Amyotrophic Lateral Sclerosis

open14noClinical signs of upper motor neuron (UMN) involvement are important in the diagnosis of amyotrophic lateral sclerosis (ALS) though are often difficult to analyze. Many studies using both qualitative and quantitative evaluations have reported abnormal Magnetic Resonance Imaging (MRI) findings at the level of the pyramidal pathway in patients with ALS. Although the most interesting results were obtained by quantitative studies using advanced MR techniques, the qualitative evaluation of MRI images remains the most-used in clinical practice. We evaluated the diagnostic and prognostic contribution of conventional 3T-MRI in the clinical work-up of ALS patients. Two neuroradiologists retrospectively assessed 3T-MRI data of 93 ALS patients and 89 controls. The features of interest were corticospinal tract (CST) T2/FLAIR hyperintensity, motor cortex (MC) T2*/SWI hypointensity, and selective MC atrophy. All MRI features were significantly more prevalent in ALS patients than in controls. The simultaneous presence of CST FLAIR hyperintensity and MC SWI hypointensity was associated with the highest diagnostic accuracy (sensitivity: 70%; specificity: 81%; positive predictive value, PPV: 90%; negative predictive value, NPV: 51%; accuracy: 73%) and a shorter survival (HR: 6.56,p= 0.002). Conventional 3T-MRI can be a feasible tool to detect specific qualitative changes based on UMN involvement and to support clinical diagnosis of ALS. Importantly, CST FLAIR hyperintensity and MC SWI hypointensity are predictors of shorter survival in ALS patients.openRizzo, Giovanni; Marliani, Anna Federica; Battaglia, Stella; Albini Riccioli, Luca; De Pasqua, Silvia; Vacchiano, Veria; Infante, Rossella; Avoni, Patrizia; Donadio, Vincenzo; Passaretti, Massimiliano; Bartolomei, Ilaria; Salvi, Fabrizio; Liguori, Rocco; On Behalf Of The BoReALS Group, nullRizzo, Giovanni; Marliani, Anna Federica; Battaglia, Stella; Albini Riccioli, Luca; De Pasqua, Silvia; Vacchiano, Veria; Infante, Rossella; Avoni, Patrizia; Donadio, Vincenzo; Passaretti, Massimiliano; Bartolomei, Ilaria; Salvi, Fabrizio; Liguori, Rocco; On Behalf Of The BoReALS Group, nul

Adipocyte-released insulin-like growth factor-1 is regulated by glucose and fatty acids and controls breast cancer cell growth in vitro

Aims/hypothesis: Type 2 diabetes and obesity are associated with increased risk of site-specific cancers. We have investigated whether metabolic alterations at the level of adipose-derived differentiating cells may affect specific phenotypes of breast cancer cells. Methods: Growth profiles of breast cancer cell lines were evaluated in co-cultures with differentiated adipocytes or their precursor cells and upon treatment with adipocyte conditioned media. Production and release of cytokines and growth factors were assessed by real-time RT-PCR and multiplex-based ELISA assays. Results: Co-cultures with either differentiated mouse 3T3-L1 or human mammary adipocytes increased viability of MCF-7 cells to a greater extent, when compared with their undifferentiated precursors. Adipocytes cultured in 25 mmol/l glucose were twofold more effective in promoting cell growth, compared with those grown in 5.5 mmol/l glucose, and activated mitogenic pathways in MCF-7 cells. Growth-promoting action was also enhanced when adipocytes were incubated in the presence of palmitate or oleate. Interestingly, 3T3-L1 and human adipocytes released higher amounts of keratinocyte-derived chemokine/IL-8, the protein 'regulated upon activation, normally T expressed, and secreted' (RANTES), and IGF-1, compared with their precursor cells. Their levels were reduced upon incubation with low glucose and enhanced by fatty acids. Moreover, both undifferentiated cells and differentiated adipocytes from obese individuals displayed about twofold higher IGF-1 release and MCF-7 cell growth induction than lean individuals. Finally, inhibition of the IGF-1 pathway almost completely prevented the growth-promoting effect of adipocytes on breast cancer cells. Conclusions/interpretation: IGF-1 release by adipocytes is regulated by glucose and fatty acids and may contribute to the control of cancer cell growth in obese individuals

Seminal Fluid Metabolomic Markers of Oligozoospermic Infertility in Humans

Infertility affects 12&ndash;15% of couples worldwide, and male factors are the cause of nearly half of all cases. Studying seminal fluid composition could lead to additional diagnostic accuracy and a better understanding of the pathophysiology of male factor infertility. Metabolomics offers a new opportunity to evaluate biomarkers and better understand pathological mechanisms. The aim of the study was to identify new markers or therapeutic targets to improve outcomes in male factor or idiopathic infertility patients. Semen samples were obtained from 29 men with a normal spermogram test, and from 18 oligozoospermic men. Samples were processed and analyzed by Nuclear Magnetic Resonance spectroscopy and, subsequently, multivariate and univariate statistical analyses. Receiving Operator Curves (ROC) and Spearman correlations were also performed. An Orthogonal Partial Least Square Discriminant Analysis supervised multivariate model was devised to compare the groups. The levels of fructose, myo-inositol, aspartate and choline were altered. Moreover, Spearman Correlation associated fructose, aspartate and myo-inositol with the total amount of spermatozoa, total motile spermatozoa, % of immotility and % of &ldquo;in situ&rdquo; spermatozoic motility respectively. NMR-based metabolomics allowed the identification of a specific metabolic fingerprint of the seminal fluids of patients affected by oligozoospermia

Bisphenol-A plasma levels are related to inflammatory markers, visceral obesity and insulin-resistance: a cross-sectional study on adult male population.

Background: The current increase of obesity and metabolic syndrome (MS) focuses attention on bisphenol-A (BPA), "obesogen" endocrine disruptor, main plastic component. Aim was to verify the role of BPA in metabolic alterations, insulin resistance, low grade inflammation and visceral obesity. Methods: A cross-sectional study was performed in 76 out of 139 environmentally exposed adult males, unselected Caucasian subjects, enrolled by routine health survey at the "Federico II" University of Naples outpatient facilities. BPA plasma levels (ELISA), metabolic risk factors, homeostasis model assessment of insulin resistance index, plasma monocyte chemoattractant protein 1, interleukin-6 (IL-6) and tumor necrosis factor-alpha were performed. Clinical and biochemical parameters have been compared with BPA and pro-inflammatory cytokines levels. Results: In total 24 subjects out of 76 (32%) presented with waist circumference (WC) >102 cm, 36 (47%) had impaired fasting glucose and 24 (32%) subjects had insulin resistance [11 out 52 (21%) with WC ≤102 cm and 13 out of 24 with WC >102 cm (54%), χ(2) 6.825, p = 0.009]. BPA and pro-inflammatory cytokine levels were significantly higher in subjects with visceral adiposity (WC > 102 cm). BPA correlated with WC, triglycerides, glucose homeostasis and inflammatory markers. At the multivariate analysis WC and IL-6 remained the main predictors of BPA. Conclusions: Detectable BPA plasma levels have been found also in our population. The strictly association between BPA and WC, components of MS, and inflammatory markers, further supports the BPA role in visceral obesity-related low grade chronic inflammation