Rossella Valentino

Prevalence of Coeliac Disease in Patients with Thyroid Autoimmunity

The occurrence of autoimmune thyroid disorders among patients with coeliac disease (CD) is well documented, but the exact prevalence of CD among patients with autoimmune thyroid diseases (ATD) is as yet unclear. We screened 150 newly diagnosed patients with ATD by serum endomysial antibody detection (EmA). In 5 subjects (3.3%) EmA positivity was found; all underwent jejunal biopsy. On gluten-free diet an excellent clinical and histological response was recorded with an improvement of hypothyroidism and reduction of the thyroxine dosage. Our data suggest a significant high prevalence (3.3%) of CD in patients with ATD, in particular with Hashimoto’s thyroiditis.

Bisphenol-A Impairs Insulin Action and Up-Regulates Inflammatory Pathways in Human Subcutaneous Adipocytes and 3T3-L1 Cells

Current evidence indicates that chemical pollutants may interfere with the homeostatic control of nutrient metabolism, thereby contributing to the increased prevalence of metabolic disorders. Bisphenol-A (BPA) is a lipophilic compound contained in plastic which is considered a candidate for impairing energy and glucose metabolism. We have investigated the impact of low doses of BPA on adipocyte metabolic functions. Human adipocytes derived from subcutaneous adipose tissue and differentiated 3T3-L1 cells were incubated with BPA, in order to evaluate the effect on glucose utilization, insulin sensitivity and cytokine secretion. Treatment with 1nM BPA significantly inhibited insulin-stimulated glucose utilization, without grossly interfering with adipocyte differentiation. Accordingly, mRNA levels of the adipogenic markers PPARγ and GLUT4 were unchanged upon BPA exposure. BPA treatment also impaired insulin-activated receptor phosphorylation and signaling. Moreover, adipocyte incubation with BPA was accompanied by increased release of IL-6 and IFN-γ, as assessed by multiplex ELISA assays, and by activation of JNK, STAT3 and NFkB pathways. Treatment of the cells with the JNK inhibitor SP600125 almost fully reverted BPA effect on insulin signaling and glucose utilization. In conclusion, low doses of BPA interfere with inflammatory/insulin signaling pathways, leading to impairment of adipose cell function.

Derangement of the hypothalamic GnRH pulse generator in women with epilepsy

An increased frequency of reproductive endocrine diseases has been described in women with epilepsy and a subclinical reproductive dysfunction has been suggested in normally menstruating epileptic women. We assessed the reproductive endocrine function in 11 normally menstruating, drug-free epileptic women, evaluating the basal hormonal profile and LH pulsatile secretion during continuous EEG monitoring. A significant LH hyperpulsatility was observed in epileptic women compared with controls; moreover, a significant increase of gonadotropin basal secretions was observed when inter-ictal paroxysmal activity increased. The derangement of the hypothalamic GnRH pulse generator may represent a subclinical condition associated with epilepsy, not necessarily affecting the regularity of menstrual function. However, it is possible that the alteration of LH pulsatile pattern might eventually cause reproductive endocrine diseases. Paroxysmal activity seems to be an important additional factor in the derangement of gonadotropin secretion.

Bisphenol A in polycystic ovary syndrome and its association with liver-spleen axis.

Bisphenol A, one of the highest‐volume chemicals currently available, is known to act as endocrine disruptor and alters several metabolic functions, including inflammatory pathways. Elevated serum levels of bisphenol A have been found in women with polycystic ovary syndrome (PCOS) and a role of low‐grade chronic inflammation has been recently reported in the pathogenesis of this syndrome. Increased spleen volume, a reliable and stable index of chronic inflammation, was strictly associated with the severity of hepatic steatosis (HS) in obese subjects, determining the so‐called liver–spleen axis.

Glucose regulates diacylglycerol intracellular levels and protein kinase C activity by modulating diacylglycerol kinase subcellular localization

Although chronic hyperglycemia reduces insulin sensitivity and leads to impaired glucose utilization, short term exposure to high glucose causes cellular responses positively regulating its own metabolism. We show that exposure of L6 myotubes overexpressing human insulin receptors to 25 mm glucose for 5 min decreased the intracellular levels of diacylglycerol (DAG). This was paralleled by transient activation of diacylglycerol kinase (DGK) and of insulin receptor signaling. Following 30-min exposure, however, both DAG levels and DGK activity returned close to basal levels. Moreover, the acute effect of glucose on DAG removal was inhibited by >85% by the DGK inhibitor R59949. DGK inhibition was also accompanied by increased protein kinase C-α (PKCα) activity, reduced glucose-induced insulin receptor activation, and GLUT4 translocation. Glucose exposure transiently redistributed DGK isoforms α and δ, from the prevalent cytosolic localization to the plasma membrane fraction. However, antisense silencing of DGKδ, but not of DGKα expression, was sufficient to prevent the effect of high glucose on PKCα activity, insulin receptor signaling, and glucose uptake. Thus, the short term exposure of skeletal muscle cells to glucose causes a rapid induction of DGK, followed by a reduction of PKCα activity and transactivation of the insulin receptor signaling. The latter may mediate, at least in part, glucose induction of its own metabolism.

Low-Dose Bisphenol-A Impairs Adipogenesis and Generates Dysfunctional 3T3-L1 Adipocytes

Environmental endocrine disruptors (EDCs), including bisphenol-A (BPA), have been recently involved in obesity and diabetes by dysregulating adipose tissue function. Our aim was to examine whether prolonged exposure to low doses of BPA could affect adipogenesis and adipocyte metabolic functions. Therefore, 3T3-L1 pre-adipocytes were cultured for three weeks with BPA 1nM to mimic human environmental exposure. We evaluated BPA effect on cell proliferation, differentiation, gene expression and adipocyte metabolic function. BPA significantly increased pre-adipocyte proliferation (p<0.01). In 3T3-L1 adipocytes differentiated in the presence of BPA, the expression of Peroxisome proliferator-activated receptor gamma (PPARγ), Fatty Acid Binding Protein 4/Adipocyte Protein 2 (FABP4/AP2) and CCAAT/enhancer binding protein (C/EBPα) was increased by 3.5, 1.5 and 3 folds, respectively. Mature adipocytes also showed a significant increase in lipid accumulation (p<0.05) and alterations of insulin action, with significant reduction in insulin-stimulated glucose utilization (p<0.001). Moreover, in mature adipocytes, mRNA levels of Leptin, interleukin-6 (IL6) and interferon-γ (IFNγ) were significantly increased (p<0.05). In conclusion, BPA prolonged exposure at low doses, consistent with those found in the environment, may affect adipocyte differentiation program, enhancing pre-adipocyte proliferation and anticipating the expression of the master genes involved in lipid/glucose metabolism. The resulting adipocytes are hypertrophic, with impaired insulin signaling, reduced glucose utilization and increased pro-inflammatory cytokine expression. Thus, these data supported the hypothesis that BPA exposure, during critical stages of adipose tissue development, may cause adipocyte metabolic dysfunction and inflammation, thereby increasing the risk of developing obesity-related diseases.

Adipose microenvironment promotes triple negative breast cancer cell invasiveness and dissemination by producing CCL5.

Growing evidence indicates that adiposity is associated with raised cancer incidence, morbidity and mortality. In a subset of tumors, cancer cell growth and/or metastasis predominantly occur in adipocyte-rich microenvironment. Indeed, adipocytes represent the most abundant cell types surrounding breast cancer cells. We have studied the mechanisms by which peritumoral human adipose tissue contributes to Triple Negative Breast Cancer (TNBC) cell invasiveness and dissemination. Co-culture with human adipocytes enhanced MDA-MB231 cancer cell invasiveness. Adipocytes cultured in high glucose were 2-fold more active in promoting cell invasion and motility compared to those cultured in low glucose. This effect is induced, at least in part, by the CC-chemokine ligand 5 (CCL5). Indeed, CCL5 inhibition by specific peptides and antibodies reduced adipocyte-induced breast cancer cell migration and invasion. CCL5 immuno-detection in peritumoral adipose tissue of women with TNBC correlated with lymph node (p-value = 0.04) and distant metastases (p-value = 0.001). A positive trend was also observed between CCL5 expression and glycaemia. Finally, Kaplan-Meier curves showed a negative correlation between CCL5 staining in the peritumoral adipose tissue and overall survival of patients (p-value = 0.039). Thus, inhibition of CCL5 in adipose microenvironment may represent a novel approach for the therapy of highly malignant TNBC.

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

BackgroundPolycystic 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.Patients and MethodsPED/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.ResultsIn 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).ConclusionsLower 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.

Functional hyperandrogenism detected by corticotropin and GnRH-analogue stimulation tests in women affected by apparently idiopathic hirsutism

The etiologic diagnosis of hirsutism is often difficult. Previous studies have reported normal basal androgen and SHBG concentrations in 33–50% of hirsute women, suggesting the presence of an “idiopathic” form of hirsutism as the most frequent cause of this problem. The recent use of GnRH-analogues together with the corticotropin stimulation test allows better understanding of whether the cause of hirsutism is androgen excess and, if so, whether the origin of the latter is ovarian, adrenal or both. The present study evaluated adrenal and ovarian function in 48 young hirsute women as well as in 78 normal women matched for body mass index and age, who acted as control group. To determine ovarian function, a single 100-μg dose of GnRH analogue triptorelin was injected sc; thereafter, gonadotropins, 17-hydroxyprogesterone (17-OHP), Δ4-androstenedione (Δ4), total testosterone (T) and estradiol were determined. To better understand the adrenal function, 250 μg of 1,24 ACTH were administrated as iv infusion for 5 h, and plasma cortisol (F), 17-OHP, Δ4, DHEAS, T, 11-desossicortisol were measured. The combined use of these two stimulation tests was able to detect mild to moderate abnormalities in the steroidogenesis of ovaries alone (23%), adrenals alone (16.6%), or both (35.4%) in most hirsute women (75%) with otherwise normal baseline androgen concentrations. In particular, patients showed significantly increased responses of 17-OHP, Δ4, total T, 11-desossicorti-sol, and F to 1,24-ACTH administration. Moreover, they also had significantly higher 17-OHP and T responses to triptorelin. In conclusion, milder forms of functional ovarian and/or adrenal hyperandrogenism, similar to those found in clearly hyperandrogenic women, were observed and could be an underlying mechanism of idiopathic hirsutism.

Platelet‐Rich Plasma Increases Growth and Motility of Adipose Tissue‐Derived Mesenchymal Stem Cells and Controls Adipocyte Secretory Function

Adipose tissue‐derived mesenchymal stem cells (Ad‐MSC) and platelet derivatives have been used alone or in combination to achieve regeneration of injured tissues. We have tested the effect of platelet‐rich plasma (PRP) on Ad‐MSC and adipocyte function. PRP increased Ad‐MSC viability, proliferation rate and G1‐S cell cycle progression, by at least 7‐, 2‐, and 2.2‐fold, respectively, and reduced caspase 3 cleavage. Higher PRP concentrations or PRPs derived from individuals with higher platelet counts were more effective in increasing Ad‐MSC growth. PRP also accelerated cell migration by at least 1.5‐fold. However, PRP did not significantly affect mature adipocyte viability, differentiation and expression levels of PPAR‐γ and AP‐2 mRNAs, while it increased leptin production by 3.5‐fold. Interestingly, PRP treatment of mature adipocytes also enhanced the release of Interleukin (IL)‐6, IL‐8, IL‐10, Interferon‐γ, and Vascular Endothelial Growth Factor. Thus, data are consistent with a stimulatory effect of platelet derivatives on Ad‐MSC growth and motility. Moreover, PRP did not reduce mature adipocyte survival and increased the release of pro‐angiogenic factors, which may facilitate tissue regeneration processes.