Intra-islet insulin synthesis defects are associated with endoplasmic reticulum stress and loss of beta cell identity in human diabetes.

AIMS/HYPOTHESIS: Endoplasmic reticulum (ER) stress and beta cell dedifferentiation both play leading roles in impaired insulin secretion in overt type 2 diabetes. Whether and how these factors are related in the natural history of the disease remains, however, unclear. METHODS: In this study, we analysed pancreas biopsies from a cohort of metabolically characterised living donors to identify defects in in situ insulin synthesis and intra-islet expression of ER stress and beta cell phenotype markers. RESULTS: We provide evidence that in situ altered insulin processing is closely connected to in vivo worsening of beta cell function. Further, activation of ER stress genes reflects the alteration of insulin processing in situ. Using a combination of 17 different markers, we characterised individual pancreatic islets from normal glucose tolerant, impaired glucose tolerant and type 2 diabetic participants and reconstructed disease progression. CONCLUSIONS/INTERPRETATION: Our study suggests that increased beta cell workload is accompanied by a progressive increase in ER stress with defects in insulin synthesis and loss of beta cell identity.

The Landscape of microRNAs in ßCell: Between Phenotype Maintenance and Protection.

Diabetes mellitus is a group of heterogeneous metabolic disorders characterized by chronic hyperglycaemia mainly due to pancreatic ß cell death and/or dysfunction, caused by several types of stress such as glucotoxicity, lipotoxicity and inflammation. Different patho-physiological mechanisms driving ß cell response to these stresses are tightly regulated by microRNAs (miRNAs), a class of negative regulators of gene expression, involved in pathogenic mechanisms occurring in diabetes and in its complications. In this review, we aim to shed light on the most important miRNAs regulating the maintenance and the robustness of ß cell identity, as well as on those miRNAs involved in the pathogenesis of the two main forms of diabetes mellitus, i.e., type 1 and type 2 diabetes. Additionally, we acknowledge that the understanding of miRNAs-regulated molecular mechanisms is fundamental in order to develop specific and effective strategies based on miRNAs as therapeutic targets, employing innovative molecules.

Non-Coding RNAs: Novel Players in Insulin Resistance and Related Diseases.

The rising prevalence of metabolic diseases related to insulin resistance (IR) have stressed the urgent need of accurate and applicable tools for early diagnosis and treatment. In the last decade, non-coding RNAs (ncRNAs) have gained growing interest because of their potential role in IR modulation. NcRNAs are variable-length transcripts which are not translated into proteins but are involved in gene expression regulation. Thanks to their stability and easy detection in biological fluids, ncRNAs have been investigated as promising diagnostic and therapeutic markers in metabolic diseases, such as type 2 diabetes mellitus (T2D), obesity and non-alcoholic fatty liver disease (NAFLD). Here we review the emerging role of ncRNAs in the development of IR and related diseases such as obesity, T2D and NAFLD, and summarize current evidence concerning their potential clinical application.

Circulating microRNAs Signature for Predicting Response to GLP1-RA Therapy in Type 2 Diabetic Patients: A Pilot Study.

Type 2 diabetes (T2D) represents one of the major health issues of this century. Despite the availability of an increasing number of anti-hyperglycemic drugs, a significant proportion of patients are inadequately controlled, thus highlighting the need for novel biomarkers to guide treatment selection. MicroRNAs (miRNAs) are small non-coding RNAs, proposed as useful diagnostic/prognostic markers. The aim of our study was to identify a miRNA signature occurring in responders to glucagon-like peptide 1 receptor agonists (GLP1-RA) therapy. We investigated the expression profile of eight T2D-associated circulating miRNAs in 26 prospectively evaluated diabetic patients in whom GLP1-RA was added to metformin. As expected, GLP1-RA treatment induced significant reductions of HbA1c and body weight, both after 6 and 12 months of therapy. Of note, baseline expression levels of the selected miRNAs revealed two distinct patient clusters: "high expressing" and "low expressing". Interestingly, a significantly higher percentage of patients in the high expression group reached the glycemic target after 12 months of treatment. Our findings suggest that the evaluation of miRNA expression could be used to predict the likelihood of an early treatment response to GLP1-RA and to select patients in whom to start such treatment, paving the way to a personalized medicine approach.

ONE MONTH WEIGHT LOSS PREDICTS THE EFFICACY OF LIRAGLUTIDE IN OBESE PATIENTS: DATA FROM A SINGLE CENTER.

Objective: Liraglutide is a glucagon-like peptide 1 receptor agonist which acts through peripheral and central receptor pathways affecting food intake. Preliminary identification of responder patients represents a crucial point to reduce an inappropriate exposure to the drug and the health expenditure. The primary endpoint of our study was to identify predictors of liraglutide efficacy in the short term follow-up. The secondary endpoint was to evaluate the treatment efficacy stratified by the underlying psychiatric disorder. Methods: We evaluated a cohort of 100 patients (77 females, 23 males, mean body mass index 38.6 ± 3.2 kg/m2) who were evaluated at baseline, and after 1, 3, and 6 months of treatment. Liraglutide efficacy was defined by a weight loss ≥5% of initial weight. Sociodemographic/metabolic parameters, food intake, smoking habit, and physical activity were correlated with liraglutide efficacy. Results: There was a significant weight loss after 1 month of therapy, as well as after 3 and 6 months when compared to the baseline (P<.0001; 27%, 45%, and 57% of patients showed a weight loss ≥5%, respectively). No difference was found in weight loss between the 3 groups of patients (with binge eating, with/without psychiatric disorders). The weight loss at 1 month was the only predictor of a positive response to the treatment. Conclusion: Our results confirm the efficacy of liraglutide even at a lower dose than conventional. The early response to the drug seems to be a good predictor of long-term efficacy and it might be useful in clinical practice to identify patients in whom liraglutide may induce a significant weight loss. Abbreviations: BMI = body mass index; EMA = European Medicine Agency; FDA = Food and Drug Administration; GLP-1 RA = glucagon-like peptide 1 receptor agonist.

Targeting microRNAs as a Therapeutic Strategy to Reduce Oxidative Stress in Diabetes.

Diabetes mellitus is a group of heterogeneous metabolic disorders characterized by chronic hyperglycaemia as a consequence of pancreatic ß cell loss and/or dysfunction, also caused by oxidative stress. The molecular mechanisms involved inß cell dysfunction and in response to oxidative stress are also regulated by microRNAs (miRNAs). miRNAs are a class of negative gene regulators, which modulate pathologic mechanisms occurring in diabetes and its complications. Although several pharmacological therapies specifically targeting miRNAs have already been developed and brought to the clinic, most previous miRNA-based drug delivery methods were unable to target a specific miRNA in a single cell type or tissue, leading to important off-target effects. In order to overcome these issues, aptamers and nanoparticles have been described as non-cytotoxic vehicles for miRNA-based drug delivery. These approaches could represent an innovative way to specifically target and modulate miRNAs involved in oxidative stress in diabetes and its complications. Therefore, the aims of this review are: (i) to report the role of miRNAs involved in oxidative stress in diabetes as promising therapeutic targets; (ii) to shed light onto the new delivery strategies developed to modulate the expression of miRNAs in diseases.

MicroRNAs as Regulators of Insulin Signaling: Research Updates and Potential Therapeutic Perspectives in Type 2 Diabetes.

The insulin signaling pathway is composed of a large number of molecules that positively or negatively modulate insulin specific signal transduction following its binding to the cognate receptor. Given the importance of the final effects of insulin signal transduction, it is conceivable that many regulators are needed in order to tightly control the metabolic or proliferative functional outputs. MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively modulate gene expression through their specific binding within the 3'UTR sequence of messenger RNA (mRNA), thus causing mRNA decoy or translational inhibition. In the last decade, miRNAs have been addressed as pivotal cellular rheostats which control many fundamental signaling pathways, including insulin signal transduction. Several studies demonstrated that multiple alterations of miRNAs expression or function are relevant for the development of insulin resistance in type 2 diabetes (T2D); such alterations have been highlighted in multiple insulin target organs including liver, muscles, and adipose tissue. Indirectly, miRNAs have been identified as modulators of inflammation-derived insulin resistance, by controlling/tuning the activity of innate immune cells in insulin target tissues. Here, we review main findings on miRNA functions as modulators of insulin signaling in physiologic- or in T2D insulin resistance- status. Additionally, we report the latest hypotheses of prospective therapies involving miRNAs as potential targets for future drugs in T2D.

MicroRNA Expression Analysis of In Vitro Dedifferentiated Human Pancreatic Islet Cells Reveals the Activation of the Pluripotency-Related MicroRNA Cluster miR-302s.

ß-cell dedifferentiation has been recently suggested as an additional mechanism contributing to type-1 and to type-2 diabetes pathogenesis. Moreover, several studies demonstrated that in vitro culture of native human pancreatic islets derived from non-diabetic donors resulted in the generation of an undifferentiated cell population. Additional evidence from in vitro human ß-cell lineage tracing experiments, demonstrated that dedifferentiated cells derive from ß-cells, thus representing a potential in vitro model of ß-cell dedifferentiation. Here, we report the microRNA expression profiles analysis of in vitro dedifferentiated islet cells in comparison to mature human native pancreatic islets. We identified 13 microRNAs upregulated and 110 downregulated in islet cells upon in vitro dedifferentiation. Interestingly, among upregulated microRNAs, we observed the activation of microRNA miR-302s cluster, previously defined as pluripotency-associated. Bioinformatic analysis indicated that miR-302s are predicted to target several genes involved in the control of ß-cell/epithelial phenotype maintenance; accordingly, such genes were downregulated upon human islet in vitro dedifferentiation. Moreover, we uncovered that cell-cell contacts are needed to maintain low/null expression levels of miR-302. In conclusion, we showed that miR-302 microRNA cluster genes are involved in in vitro dedifferentiation of human pancreatic islet cells and inhibits the expression of multiple genes involved in the maintenance of ß-cell mature phenotype.

A set of circulating microRNAs belonging to the 14q32 chromosome locus identifies two subgroups of individuals with recent-onset type 1 diabetes.

Circulating microRNAs (miRNAs) are linked to the onset and progression of type 1 diabetes mellitus (T1DM), thus representing potential disease biomarkers. In this study, we employed a multiplatform sequencing approach to analyze circulating miRNAs in an extended cohort of prospectively evaluated recent-onset T1DM individuals from the INNODIA consortium. Our findings reveal that a set of miRNAs located within T1DM susceptibility chromosomal locus 14q32 distinguishes two subgroups of individuals. To validate our results, we conducted additional analyses on a second cohort of T1DM individuals, confirming the identification of these subgroups, which we have named cluster A and cluster B. Remarkably, cluster B T1DM individuals, who exhibit increased expression of a set of 14q32 miRNAs, show better glycemic control and display a different blood immunomics profile. Our findings suggest that this set of circulating miRNAs can identify two different T1DM subgroups with distinct blood immunomics at baseline and clinical outcomes during follow-up.

New Advances in Metabolic Syndrome, from Prevention to Treatment: The Role of Diet and Food.

The definition of metabolic syndrome (MetS) has undergone several changes over the years due to the difficulty in establishing universal criteria for it. Underlying the disorders related to MetS is almost invariably a pro-inflammatory state related to altered glucose metabolism, which could lead to elevated cardiovascular risk. Indeed, the complications closely related to MetS are cardiovascular diseases (CVDs) and type 2 diabetes (T2D). It has been observed that the predisposition to metabolic syndrome is modulated by complex interactions between human microbiota, genetic factors, and diet. This review provides a summary of the last decade of literature related to three principal aspects of MetS: (i) the syndrome's definition and classification, pathophysiology, and treatment approaches; (ii) prediction and diagnosis underlying the biomarkers identified by means of advanced methodologies (NMR, LC/GC-MS, and LC, LC-MS); and (iii) the role of foods and food components in prevention and/or treatment of MetS, demonstrating a possible role of specific foods intake in the development of MetS.

Follow-up after bariatric surgery: is it time to tailor it? Analysis of early predictive factors of 3-year weight loss predictors of unsuccess in bariatric patients.

Bariatric surgery (BS) is the most effective treatment strategy for obesity. Nevertheless, a subset of patients does not reach a successful weight loss or experience long-term weight regain. Conflicting evidence exists regarding predictors of BS outcomes. We aimed to define the early factors linked to 3 year unsuccessful weight loss in order to promote a tailored close follow-up. We enrolled 443 patients who underwent BS from January 2014 to December 2018 with a 3 year follow-up. An unsuccessful BS outcome was defined as a percentage of total weight loss (%TWL) < 20. We compared the characteristics between successful and unsuccessful patients in order to identify predictor factors of unsuccess after surgery. We found that the proportion of patients with unsuccessful weight loss progressively increased from one to three years after BS. In a multiple regression model, only 1 month %TWL and sleeve gastrectomy (SG) were significantly associated with 3 year unsuccessful weight loss. We stratified our cohort in four groups according to the risk of BS unsuccess, in terms of 1 month %TWL and type of surgery (SG vs gastric bypass). Interestingly, groups showed a significant difference in terms of %TWL at each follow-up point. Patients submitted to SG with lower 1 month %TWL must be considered at higher risk of future weight regain; consequently, they require a tailored and closer follow-up.

Circulating microRNAs as clinically useful biomarkers for Type 2 Diabetes Mellitus: miRNomics from bench to bedside.

Type 2 diabetes (T2D), a chronic metabolic disease, has attained the status of a global epidemic with steadily increasing incidence worldwide. Improved diagnosis, stratification and prognosis of T2D patients and the development of more effective treatments are needed. In this era of personalized medicine, the discovery and evaluation of innovative circulating biomarkers can be an effective tool for better stratification, prognosis and therapeutic selection/management of T2D patients. MicroRNAs (miRNAs), a class of small non-coding RNAs that modulate gene expression, have been investigated as potential circulating biomarkers in T2D. Several studies have investigated the expression of circulating miRNAs in T2D patients from various biological fluids, including plasma and serum, and have demonstrated their potential as diagnostic and prognostic biomarkers, as well as biomarkers of response to therapy. In this review, we provide an overview of the current state of knowledge, focusing on circulating miRNAs that have been consistently expressed in at least two independent studies, in order to identify a set of consistent biomarker candidates in T2D. The expression levels of miRNAs, correlation with clinical parameters, functional roles of miRNAs and their potential as biomarkers are reported. A systematic literature search and assessment of studies led to the selection and review of 10 miRNAs (miR-126-3p, miR-223-3p, miR-21-5p, miR-15a-5p, miR-24-3p, miR-34a-5p, miR-146a-5p, miR-148a-3p, miR-30d-5p and miR-30c-5p). We also present technical challenges and our thoughts on the potential validation of circulating miRNAs and their application as biomarkers in the context of T2D.

Increased Expression of Viral Sensor MDA5 in Pancreatic Islets and in Hormone-Negative Endocrine Cells in Recent Onset Type 1 Diabetic Donors.

The interaction between genetic and environmental factors determines the development of type 1 diabetes (T1D). Some viruses are capable of infecting and damaging pancreatic ß-cells, whose antiviral response could be modulated by specific viral RNA receptors and sensors such as melanoma differentiation associated gene 5 (MDA5), encoded by the IFIH1 gene. MDA5 has been shown to be involved in pro-inflammatory and immunoregulatory outcomes, thus determining the response of pancreatic islets to viral infections. Although the function of MDA5 has been previously well explored, a detailed immunohistochemical characterization of MDA5 in pancreatic tissues of nondiabetic and T1D donors is still missing. In the present study, we used multiplex immunofluorescence imaging analysis to characterize MDA5 expression and distribution in pancreatic tissues obtained from 22 organ donors (10 nondiabetic autoantibody-negative, 2 nondiabetic autoantibody-positive, 8 recent-onset, and 2 long-standing T1D). In nondiabetic control donors, MDA5 was expressed both in α- and ß-cells. The colocalization rate imaging analysis showed that MDA5 was preferentially expressed in α-cells. In T1D donors, we observed an increased colocalization rate of MDA5-glucagon with respect to MDA5-insulin in comparison to nondiabetic controls; such increase was more pronounced in recent-onset with respect to long-standing T1D donors. Of note, an increased colocalization rate of MDA5-glucagon was found in insulin-deficient-islets (IDIs) with respect to insulin-containing-islets (ICIs). Strikingly, we detected the presence of MDA5-positive/hormone-negative endocrine islet-like clusters in T1D donors, presumably due to dedifferentiation or neogenesis phenomena. These clusters were identified exclusively in donors with recent disease onset and not in autoantibody-positive nondiabetic donors or donors with long-standing T1D. In conclusion, we showed that MDA5 is preferentially expressed in α-cells, and its expression is increased in recent-onset T1D donors. Finally, we observed that MDA5 may also characterize the phenotype of dedifferentiated or newly forming islet cells, thus opening to novel roles for MDA5 in pancreatic endocrine cells.

Reduced miR-184-3p expression protects pancreatic ß-cells from lipotoxic and proinflammatory apoptosis in type 2 diabetes via CRTC1 upregulation.

The loss of functional ß-cell mass in type 2 diabetes (T2D) is associated with molecular events that include ß-cell apoptosis, dysfunction and/or dedifferentiation. MicroRNA miR-184-3p has been shown to be involved in several ß-cell functions, including insulin secretion, proliferation and survival. However, the downstream targets and upstream regulators of miR-184-3p have not been fully elucidated. Here, we show reduced miR-184-3p levels in human T2D pancreatic islets, whereas its direct target CREB regulated transcription coactivator 1 (CRTC1) was increased and protects ß-cells from lipotoxicity- and inflammation-induced apoptosis. Downregulation of miR-184-3p in ß-cells leads to upregulation of CRTC1 at both the mRNA and protein levels. Remarkably, the protective effect of miR-184-3p is dependent on CRTC1, as its silencing in human ß-cells abrogates the protective mechanism mediated by inhibition of miR-184-3p. Furthermore, in accordance with miR-184-3p downregulation, we also found that the ß-cell-specific transcription factor NKX6.1, DNA-binding sites of which are predicted in the promoter sequence of human and mouse MIR184 gene, is reduced in human pancreatic T2D islets. Using chromatin immunoprecipitation analysis and mRNA silencing experiments, we demonstrated that NKX6.1 directly controls both human and murine miR-184 expression. In summary, we provide evidence that the decrease in NKX6.1 expression is accompanied by a significant reduction in miR-184-3p expression and that reduction of miR-184-3p protects ß-cells from apoptosis through a CRTC1-dependent mechanism.

Extracellular Vesicles in Immune System Regulation and Type 1 Diabetes: Cell-to-Cell Communication Mediators, Disease Biomarkers, and Promising Therapeutic Tools.

Extracellular vesicles (EVs) are generated by cells of origin through complex molecular mechanisms and released into extracellular environment. Hence, the presence of EVs has been described in multiple biological fluids and in most cases their molecular cargo, which includes non-coding RNAs (ncRNA), messenger RNAs (mRNA), and proteins, has been reported to modulate distinct biological processes. EVs release and their molecular cargo have been demonstrated to be altered in multiple diseases, including autoimmune diseases. Notably, numerous evidence showed a relevant crosstalk between immune system and interacting cells through specific EVs release. The crosstalk between insulin-producing pancreatic ß cells and immune system through EVs bidirectional trafficking has yet started to be deciphered, thus uncovering an intricate communication network underlying type 1 diabetes (T1D) pathogenesis. EVs can also be found in blood plasma or serum. Indeed, the assessment of circulating EVs cargo has been shown as a promising advance in the detection of reliable biomarkers of disease progression. Of note, multiple studies showed several specific cargo alterations of EVs collected from plasma/serum of subjects affected by autoimmune diseases, including T1D subjects. In this review, we discuss the recent literature reporting evidence of EVs role in autoimmune diseases, specifically focusing on the bidirectional crosstalk between pancreatic ß cells and immune system in T1D and highlight the relevant promising role of circulating EVs as disease biomarkers.

Protocol to analyze circulating small non-coding RNAs by high-throughput RNA sequencing from human plasma samples.

The identification and validation of circulating small non-coding RNA (sncRNA) as biomarkers for disease diagnosis, staging, and response to novel therapies is still a compelling challenge. Pre-analytical variables, such as storage temperature or blood hemolysis, and different analytical approaches affect sncRNA stability, detection, and expression, resulting in discrepancies among studies. Here, we report a systematic standardized protocol to reproducibly analyze circulating sncRNAs, employing high-throughput sncRNA sequencing and qRT-PCR validation, from 200 µL of human plasma samples. For details on the use and execution of this protocol, please refer to Ventriglia et al. (2020), Sebastiani et al. (2017), and Dotta et al. (2018).

Ten years of experience with DPP-4 inhibitors for the treatment of type 2 diabetes mellitus.

Achieving and maintaining recommended glycemic targets without causing adverse e ffects, including hypoglycemia, is challenging, especially in older patients with type 2 diabetes mellitus (T2DM). The introduction of dipeptidyl peptidase-4 (DPP-4) inhibitors, more than 10 years ago, has provided an alternative to conventional medications for the intensification of glucose-lowering treatment after failure of metformin monotherapy, and therefore, marked an important advance in the management of T2DM. By prolonging the activity of incretin hormones, DPP-4 inhibitors induce insulin release and decrease glucagon secretion in a glucose-dependent manner. This results in a more physiologic glycemic control as compared to that ensured by insulin secretagogues (sulfonylureas and glinides). Overall, DPP-4 inhibitors have a favorable safety profile and can be used without dose adjustments in older adults and in patients with mild renal impairment; they have a neutral effect on body weight and do not cause hypoglycemia by themselves. Safety issues, reported mainly in post-marketing surveillance programs and including cardiovascular outcomes and the risk of acute pancreatitis, are being extensively investigated. The aim of this review is to discuss the impact of DPP-4 inhibitors on the treatment of T2DM, after 10 years of experience, with an emphasis on diabetes care in Italy. We will first describe T2DM treatment in Italy and then provide an overview of the main findings from randomized controlled trials, real-world studies and post-marketing surveillance programs with DPP-4 inhibitors.

Circulating microRNA (miRNA) Expression Profiling in Plasma of Patients with Gestational Diabetes Mellitus Reveals Upregulation of miRNA miR-330-3p.

Gestational diabetes mellitus (GDM) is characterized by insulin resistance accompanied by low/absent beta-cell compensatory adaptation to the increased insulin demand. Although the molecular mechanisms and factors acting on beta-cell compensatory response during pregnancy have been partially elucidated and reported, those inducing an impaired beta-cell compensation and function, thus evolving in GDM, have yet to be fully addressed. MicroRNAs (miRNAs) are a class of small endogenous non-coding RNAs, which negatively modulate gene expression through their sequence-specific binding to 3'UTR of mRNA target. They have been described as potent modulators of cell survival and proliferation and, furthermore, as orchestrating molecules of beta-cell compensatory response and function in diabetes. Moreover, it has been reported that miRNAs can be actively secreted by cells and found in many biological fluids (e.g., serum/plasma), thus representing both optimal candidate disease biomarkers and mediators of tissues crosstalk(s). Here, we analyzed the expression profiles of circulating miRNAs in plasma samples obtained from n = 21 GDM patients and from n = 10 non-diabetic control pregnant women (24-33 weeks of gestation) using TaqMan array microfluidics cards followed by RT-real-time PCR single assay validation. The results highlighted the upregulation of miR-330-3p in plasma of GDM vs non-diabetics. Furthermore, the analysis of miR-330-3p expression levels revealed a bimodally distributed GDM patients group characterized by high or low circulating miR-330 expression and identified as GDM-miR-330high and GDM-miR-330low. Interestingly, GDM-miR-330high subgroup retained lower levels of insulinemia, inversely correlated to miR-330-3p expression levels, and a significant higher rate of primary cesarean sections. Finally, miR-330-3p target genes analysis revealed major modulators of beta-cell proliferation and of insulin secretion, such as the experimentally validated genes E2F1 and CDC42 as well as AGT2R2, a gene involved in the differentiation of mature beta-cells. In conclusion, we demonstrated that plasma miR-330-3p could be of help in identifying GDM patients with potential worse gestational diabetes outcome; in GDM, miR-330-3p may directly be transferred from plasma to beta-cells thus modulating key target genes involved in proliferation, differentiation, and insulin secretion.

Bariatric Surgery Reduces Serum Anti-mullerian Hormone Levels in Obese Women With and Without Polycystic Ovarian Syndrome.

PURPOSE: Obesity in fertile women has negative effect on fertility. Anti-mullerian hormone (AMH) represents a good index of fertility, and it is considered a marker of ovarian reserve and of polycystic ovarian syndrome (PCOS) gravity. Previous studies evaluated the relationship between obesity and AMH with contradictory results. The aim of the study was to investigate the relationship between obesity and AMH and the changes of AMH in obese women in reproductive age submitted to bariatric surgery. MATERIALS AND METHODS: Fifty-five obese patients between 18 and 39 years with (29 patients) and without PCOS (26 patients) were compared with a control group of normal weight women with (24 patients) and without PCOS (19 patients). Fourteen obese women with PCOS and 18 without PCOS underwent to bariatric surgery. Serum AMH, testosterone, androstenedione, and DHEAS were performed in all patients before and 1 year after surgical intervention. RESULTS: AMH was significantly higher in the PCOS groups (p < 0.001), both in obese (5.84 ± 3.94 ng/ml) and non-obese women (7.35 ± 4.39 ng/ml). AMH was positively related to testosterone (p < 0.0001), androstenedione (p = 0.0005), and DHEAS (p = 0.003). After bariatric surgery, AMH levels were reduced in the both PCOS (p = 0.02) and non-PCOS group (p = 0.04). CONCLUSIONS: AMH levels are elevated in PCOS patients regardless of the body weight. Bariatric surgery is effective in the normalization of AMH levels (a possible indirect marker of better fertility) only in obese patients with PCOS.

Regulatory T-cells from pancreatic lymphnodes of patients with type-1 diabetes express increased levels of microRNA miR-125a-5p that limits CCR2 expression.

Autoimmune type 1 diabetes (T1D) is thought to be caused by a defective immune regulation with regulatory T (Treg) cells playing a fundamental role in this process. Tolerance mechanisms depend on tunable responses that are sensitive to minor perturbations in the expression of molecules that can be carried out by multiple epigenetic mechanisms, including regulation by microRNAs. In this study, microRNA expression profile was investigated in Treg cells isolated from peripheral blood (PB) and from pancreatic draining lymph nodes (PLN) of T1D patients and non-diabetic subjects. Among 72 microRNAs analyzed, miR-125a-5p resulted specifically hyper-expressed in Treg cells purified from PLN of T1D patients. TNFR2 and CCR2 were identified as miR-125a-5p target genes. Elevated miR-125a-5p was detected in Treg cells isolated from PLN but not from PB of donors with T1D and was associated with reduced CCR2 expression. A specific beta-cell expression of the CCR2-ligand (CCL2) was observed in the pancreata of cadaveric donors, suggesting that beta-cells are prone to attract CCR2+ Treg cells. These novel data propose a mechanism, occurring in PLNs of T1D patients, involving increased expression of miR-125a-5p on Treg cells which results into reduced expression of CCR2, thus limiting their migration and eventual function in the pancreas.