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.

Pancreatic beta-cell IL-22 receptor deficiency induces age-dependent dysregulation of insulin biosynthesis and systemic glucose homeostasis.

The IL-22RA1 receptor is highly expressed in the pancreas, and exogenous IL-22 has been shown to reduce endoplasmic reticulum and oxidative stress in human pancreatic islets and promote secretion of high-quality insulin from beta-cells. However, the endogenous role of IL-22RA1 signaling on these cells remains unclear. Here, we show that antibody neutralisation of IL-22RA1 in cultured human islets leads to impaired insulin quality and increased cellular stress. Through the generation of mice lacking IL-22ra1 specifically on pancreatic alpha- or beta-cells, we demonstrate that ablation of murine beta-cell IL-22ra1 leads to similar decreases in insulin secretion, quality and islet regeneration, whilst increasing islet cellular stress, inflammation and MHC II expression. These changes in insulin secretion led to impaired glucose tolerance, a finding more pronounced in female animals compared to males. Our findings attribute a regulatory role for endogenous pancreatic beta-cell IL-22ra1 in insulin secretion, islet regeneration, inflammation/cellular stress and appropriate systemic metabolic regulation.

Analytical performance of free testosterone calculated by direct immunoluminometric method compared with the Vermeulen equation: results from a clinical series.

INTRODUCTION: Testosterone (T) is a hormone that is crucial for primary and secondary sexual development in both males and females. Free testosterone (FT) represents the biologically active form of T, and its measurement is of great importance in clinical practice. While application of either equilibrium dialysis or ultrafiltration is considered to be the gold standard for FT assessment, these methods are expensive and not widely accessible. As an alternative, the Vermeulen formula is a commonly utilized calculated method. METHODS: This clinical study, including 190 consecutive patients, was carried out to compare FT levels obtained through direct immunoluminometric assay and the Vermeulen formula. The comparison was performed using Passing-Bablok and Deming regression as well as the Bland-Altman plot. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were assessed. RESULTS: The calculated method employing the Vermeulen formula was considered the gold standard. Passing-Bablok regression indicated a good agreement between the two methods, with slopes close to 1 for the whole series. Although the Bland-Altman plot demonstrated overall agreement, a potential proportional bias was observed in females. Deming regression confirmed excellent agreement and reliable estimates. Sensitivity and specificity analysis revealed that the direct method had a sensitivity of 75.0% and a specificity of 93.4% in all patients. However, sensitivity improved to 81.0% in males and dropped to 18.2% in females likely due to the low number of true positive cases. CONCLUSION: The direct method exhibited comparable performance to the calculated method, but caution should be exercised when interpreting results, particularly in females. Further studies are necessary to validate its sensitivity and specificity in larger series.

12-Month Efficacy of Advanced Hybrid Closed-Loop System in Adult Type 1 Diabetes Patients.

Automated insulin delivery (AID) systems have improved glycemic control in individuals with type 1 diabetes (T1D). The "advanced hybrid closed loop" (AHCL) stands out as the most recent development in AID systems for T1D management. In a real-world clinical environment, we retrospectively evaluated the AHCL MiniMed™ 780G system's effectiveness to achieve and sustain glycemic control over a 12-month period in 22 adult T1D subjects. Within just 14 days of activating the automatic mode, the AHCL MiniMed 780G system showed rapid improvement in glycemic control, which persisted for 12 months. These findings underscore the effectiveness of AHCL systems in achieving and preserving optimal glycemic control in adults with T1D over a very long follow-up.

Combined 18F-FDG PET-CT markers in dementia with Lewy bodies.

INTRODUCTION: 18F-Fluoro-deoxyglucose-positron emission tomography (FDG-PET) is a supportive biomarker in dementia with Lewy bodies (DLB) diagnosis and its advanced analysis methods, including radiomics and machine learning (ML), were developed recently. The aim of this study was to evaluate the FDG-PET diagnostic performance in predicting a DLB versus Alzheimer's disease (AD) diagnosis. METHODS: FDG-PET scans were visually and semi-quantitatively analyzed in 61 patients. Radiomics and ML analyses were performed, building five ML models: (1) clinical features; (2) visual and semi-quantitative PET features; (3) radiomic features; (4) all PET features; and (5) overall features. RESULTS: At follow-up, 34 patients had DLB and 27 had AD. At visual analysis, DLB PET signs were significantly more frequent in DLB, having the highest diagnostic accuracy (86.9%). At semi-quantitative analysis, the right precuneus, superior parietal, lateral occipital, and primary visual cortices showed significantly reduced uptake in DLB. The ML model 2 had the highest diagnostic accuracy (84.3%). DISCUSSION: FDG-PET is a valuable tool in DLB diagnosis, having visual and semi-quantitative analyses with the highest diagnostic accuracy at ML analyses.

A systematic review of data sources for artificial intelligence applications in pediatric brain tumors in Europe: implications for bias and generalizability.

Introduction: Europe works to improve cancer management through the use of artificialintelligence (AI), and there is a need to accelerate the development of AI applications for childhood cancer. However, the current strategies used for algorithm development in childhood cancer may have bias and limited generalizability. This study reviewed existing publications on AI tools for pediatric brain tumors, Europe's most common type of childhood solid tumor, to examine the data sources for developing AI tools. Methods: We performed a bibliometric analysis of the publications on AI tools for pediatric brain tumors, and we examined the type of data used, data sources, and geographic location of cohorts to evaluate the generalizability of the algorithms. Results: We screened 10503 publications, and we selected 45. A total of 34/45 publications developing AI tools focused on glial tumors, while 35/45 used MRI as a source of information to predict the classification and prognosis. The median number of patients for algorithm development was 89 for single-center studies and 120 for multicenter studies. A total of 17/45 publications used pediatric datasets from the UK. Discussion: Since the development of AI tools for pediatric brain tumors is still in its infancy, there is a need to support data exchange and collaboration between centers to increase the number of patients used for algorithm training and improve their generalizability. To this end, there is a need for increased data exchange and collaboration between centers and to explore the applicability of decentralized privacy-preserving technologies consistent with the General Data Protection Regulation (GDPR). This is particularly important in light of using the European Health Data Space and international collaborations.

Angiotensin I-converting enzyme type 2 expression is increased in pancreatic islets of type 2 diabetic donors.

AIMS: Angiotensin I-converting enzyme type 2 (ACE2), a pivotal SARS-CoV-2 receptor, has been shown to be expressed in multiple cells, including human pancreatic beta-cells. A putative bidirectional relationship between SARS-CoV-2 infection and diabetes has been suggested, confirming the hypothesis that viral infection in beta-cells may lead to new-onset diabetes or worse glycometabolic control in diabetic patients. However, whether ACE2 expression levels are altered in beta-cells of diabetic patients has not yet been investigated. Here, we aimed to elucidate the in situ expression pattern of ACE2 in Type 2 diabetes (T2D) with respect to non-diabetic donors which may account for a higher susceptibility to SARS-CoV-2 infection in beta-cells. MATERIAL AND METHODS: Angiotensin I-converting enzyme type 2 immunofluorescence analysis using two antibodies alongside insulin staining was performed on formalin-fixed paraffin embedded pancreatic sections obtained from n = 20 T2D and n = 20 non-diabetic (ND) multiorgan donors. Intensity and colocalisation analyses were performed on a total of 1082 pancreatic islets. Macrophage detection was performed using anti-CD68 immunohistochemistry on serial sections from the same donors. RESULTS: Using two different antibodies, ACE2 expression was confirmed in beta-cells and in pancreas microvasculature. Angiotensin I-converting enzyme type 2 expression was increased in pancreatic islets of T2D donors in comparison to ND controls alongside with a higher colocalisation rate between ACE2 and insulin using both anti-ACE2 antibodies. CD68+ cells tended to be increased in T2D pancreata, in line with higher ACE2 expression observed in serial sections. CONCLUSIONS: Higher ACE2 expression in T2D islets might increase their susceptibility to SARS-CoV-2 infection during COVID-19 in T2D patients, thus worsening glycometabolic outcomes and disease severity.

A Plasma miR-193b-365 Signature Combined With Age and Glycemic Status Predicts Response to Lactococcus lactis-Based Antigen-Specific Immunotherapy in New-Onset Type 1 Diabetes.

Immunomodulation combined with antigen therapy holds great promise to arrest autoimmune type 1 diabetes, but clinical translation is hampered by a lack of prognostic biomarkers. Low-dose anti-CD3 plus Lactococcus lactis bacteria secreting proinsulin and IL-10 reversed new-onset disease in nonobese diabetic (NOD) mice, yet some mice were resistant to the therapy. Using miRNA profiling, six miRNAs (i.e., miR-34a-5p, miR-125a-3p, miR-193b-3p, miR-328, miR-365-3p, and miR-671-3p) were identified as differentially expressed in plasma of responder versus nonresponder mice before study entry. After validation and stratification in an independent cohort, plasma miR-193b-3p and miR-365-3p, combined with age and glycemic status at study entry, had the best power to predict, with high sensitivity and specificity, poor response to the therapy. These miRNAs were highly abundant in pancreas-infiltrating neutrophils and basophils with a proinflammatory and activated phenotype. Here, a set of miRNAs and disease-associated parameters are presented as a predictive signature for the L. lactis-based immunotherapy outcome in new-onset type 1 diabetes, hence allowing targeted recruitment of trial participants and accelerated trial execution. ARTICLE HIGHLIGHTS: Low-dose anti-CD3 combined with oral gavage of genetically modified Lactococcus lactis bacteria secreting human proinsulin and IL-10 holds great promise to arrest autoimmune type 1 diabetes, but the absence of biomarkers predicting therapeutic success hampers clinical translation. A set of cell-free circulation miRNAs together with age and glycemia at baseline predicts a poor response after L. lactis-based immunotherapy in nonobese mice with new-onset diabetes. Pancreas-infiltrating neutrophils and basophils are identified as potential cellular sources of discovered miRNAs. The prognostic signature could guide targeted recruitment of patients with newly diagnosed type 1 diabetes in clinical trials with the L. lactis-based immunotherapy.

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.

Risk of Intraocular Pressure Increase With Intravitreal Injections of Vascular Endothelial Growth Factor Inhibitors: A Cohort Study.

PURPOSE: Intraocular pressure increase (IOPi) after intravitreal injections of vascular endothelial growth factor inhibitors (VEGFis) might be different among different VEGFis (bevacizumab, aflibercept, ranibizumab). The purpose of this study was to evaluate the risk of IOPi among new users of bevacizumab, ranibizumab, and aflibercept in nondiabetic patients in Tuscany, Italy. DESIGN: Retrospective cohort study. METHODS: Tuscan regional administrative database was used to identify subjects with a first VEGFi intravitreal injection between 2011 and 2020, followed to first incidence of IOPi. Diabetic subjects, those with pre-existing IOPi, or previous use of dexamethasone implants were excluded. Multivariable Cox regression analyses (intention-to-treat and as treated) were conducted to evaluate risk of IOPi among aflibercept, bevacizumab, and ranibizumab, adjusting for potential confounding variables. IOPi was defined as the first record of International Classification of Diseases, Ninth Revision (ICD-9-CM) code 365 or use of 2 glaucoma drugs dispensations within 180 days of each other. RESULTS: We identified 6585 new users of VEGFis: 1749 aflibercept, 1112 bevacizumab, and 3724 ranibizumab. Women made up 60% of the cohort, with a mean age of 73.6 years. In the intention-to-treat analysis, the adjusted hazard ratio (HR) for incident IOPi, compared with aflibercept, was higher for bevacizumab (HR = 2.20, 95% CI = 1.64-2.95) and ranibizumab users (HR = 1.88, 95% CI = 1.46-2.42), respectively. The HRs remained robust after exclusion of patients with proxy of retinal vascular occlusion. As treated analysis confirmed such results (bevacizumab: HR = 3.76, 95% CI = 2.30-6.17; ranibizumab: HR = 2.49, 95% CI = 1.62-3.82). CONCLUSIONS: This study found an increased risk of IOPi among nondiabetic patients with ranibizumab and bevacizumab compared with aflibercept. Future studies are needed to validate these findings.

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.

Developing a Predictive Grading Model for Children with Gliomas Based on Diffusion Kurtosis Imaging Metrics: Accuracy and Clinical Correlations with Patient Survival.

Purpose: To develop a predictive grading model based on diffusion kurtosis imaging (DKI) metrics in children affected by gliomas, and to investigate the clinical impact of the predictive model by correlating with overall survival and progression-free survival. Materials and methods: 59 patients with a histological diagnosis of glioma were retrospectively studied (33 M, 26 F, median age 7.2 years). Patients were studied on a 3T scanner with a standardized MR protocol, including conventional and DKI sequences. Mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) maps were obtained. Whole tumour volumes (VOIs) were segmented semi-automatically. Mean DKI values were calculated for each metric. The quantitative values from DKI-derived metrics were used to develop a predictive grading model to develop a probability prediction of a high-grade glioma (pHGG). Three models were tested: DTI-based, DKI-based, and combined (DTI and DKI). The grading accuracy of the resulting probabilities was tested with a receiver operating characteristics (ROC) analysis for each model. In order to account for dataset imbalances between pLGG and pHGG, we applied a random synthetic minority oversampling technique (SMOTE) analysis. Lastly, the most accurate model predictions were correlated with progression-free survival (PFS) and overall survival (OS) using the Kaplan−Meier method. Results: The cohort included 46 patients with pLGG and 13 patients with pHGG. The developed model predictions yielded an AUC of 0.859 (95%CI: 0.752−0.966) for the DTI model, of 0.939 (95%CI: 0.879−1) for the DKI model, and of 0.946 (95%CI: 0.890−1) for the combined model, including input from both DTI and DKI metrics, which resulted in the most accurate model. Sample estimation with the random SMOTE analysis yielded an AUC of 0.98 on the testing set. Model predictions from the combined model were significantly correlated with PFS (25.2 months for pHGG vs. 40.0 months for pLGG, p < 0.001) and OS (28.9 months for pHGG vs. 44.9 months for pLGG, p < 0.001). Conclusions: a DKI-based predictive model was highly accurate for pediatric glioma grading. The combined model, derived from both DTI and DKI metrics, proved that DKI-based model predictions of tumour grade were significantly correlated with progression-free survival and overall survival.

Outer Membrane Vesicles From The Gut Microbiome Contribute to Tumor Immunity by Eliciting Cross-Reactive T Cells.

A growing body of evidence supports the notion that the gut microbiome plays an important role in cancer immunity. However, the underpinning mechanisms remain to be fully elucidated. One attractive hypothesis envisages that among the T cells elicited by the plethora of microbiome proteins a few exist that incidentally recognize neo-epitopes arising from cancer mutations ("molecular mimicry (MM)" hypothesis). To support MM, the human probiotic Escherichia coli Nissle was engineered with the SIINFEKL epitope (OVA-E.coli Nissle) and orally administered to C57BL/6 mice. The treatment with OVA-E.coli Nissle, but not with wild type E. coli Nissle, induced OVA-specific CD8+ T cells and inhibited the growth of tumors in mice challenged with B16F10 melanoma cells expressing OVA. The microbiome shotgun sequencing and the sequencing of TCRs from T cells recovered from both lamina propria and tumors provide evidence that the main mechanism of tumor inhibition is mediated by the elicitation at the intestinal site of cross-reacting T cells, which subsequently reach the tumor environment. Importantly, the administration of Outer Membrane Vesicles (OMVs) from engineered E. coli Nissle, as well as from E. coli BL21(DE3)ΔompA, carrying cancer-specific T cell epitopes also elicited epitope-specific T cells in the intestine and inhibited tumor growth. Overall, our data strengthen the important role of MM in tumor immunity and assign a novel function of OMVs in host-pathogen interaction. Moreover, our results pave the way to the exploitation of probiotics and OMVs engineered with tumor specific-antigens as personalized mucosal cancer vaccines.

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.

Crosstalk between MicroRNA and Oxidative Stress in Physiology and Pathology 2.0.

MicroRNAs (miRNAs) are a class of small non-coding RNAs around 22 nucleotides long that regulate gene expression by binding specific sequences within target messenger RNA (mRNA) [...].

NF-κB-inducing kinase (NIK) is activated in pancreatic ß-cells but does not contribute to the development of diabetes.

The transcription factor nuclear factor-κB (NF-κB) has a key role in the pathogenesis of diabetes and its complications. Although activation of the canonical NF-κB pathway in ß-cells is generally deleterious, little is known about the role of the non-canonical NF-κB signalling and its main regulator, the NF-κB-inducing kinase (NIK), on pancreatic ß-cell survival and function. Previous studies based on models of NIK overexpression in pancreatic islet cells showed that NIK induced either spontaneous ß-cell death due to islet inflammation or glucose intolerance during diet-induced obesity (DIO) in mice. Therefore, NIK has been proposed as a potential target for diabetes therapy. However, no clear studies showed whether inhibition of NIK improves diabetes development. Here we show that genetic silencing of NIK in pancreatic ß-cells neither modifies diabetes incidence nor inflammatory responses in a mouse model of immune-mediated diabetes. Moreover, NIK silencing in DIO mice did not influence body weight gain, nor glucose metabolism. In vitro studies corroborated the in vivo findings in terms of ß-cell survival, function, and downstream gene regulation. Taken together, our data suggest that NIK activation is dispensable for the development of diabetes.

Serum Proteomic Profile of Asthmatic Patients after Six Months of Benralizumab and Mepolizumab Treatment.

Severe eosinophilic asthma is characterized by chronic airway inflammation, oxidative stress, and elevated proinflammatory cytokines, especially IL-5. Mepolizumab and benralizumab are both humanized IgG antibodies directed against IL-5 signaling, directly acting on eosinophils count. Together with the complexity of severe asthma classification and patient selection for the targeted treatment, there is also the urgency to clarify the follow-up of therapy to identify biomarkers, in addition to eosinophils, for the optimal duration of treatment, persistence of effectiveness, and safety. To this purpose, here we performed a follow-up study using differential proteomic analysis on serum samples after 1 and 6 months of both therapies and sera from healthy patients. Statistical analysis by PCA and heatmap analyses were performed, and identified proteins were used for enrichment analysis by MetaCore software. The analysis highlighted 82 differences among all considered conditions. In particular, 30 referred to benralizumab time point (T0, T1B, T6B) and 24 to mepolizumab time point (T0, T1M, T6M) analyses. t-SNE and heatmap analyses evidence that the differential serum protein profile at 6 months of both treatments is more similar to that of the healthy subjects. Among the identified proteins, APOAI, APOC-II, and APOC-III are upregulated principally after 6 months of benralizumab treatment, plasminogen is upregulated after 6 months of both treatments and ceruloplasmin, upregulated already after 1 month of benralizumab, becoming higher after 6 months of mepolizumab. Using enrichment analysis, identified proteins were related to lipid metabolism and transport, blood coagulation, and ECM remodeling.

Identification and Validation of miR-222-3p and miR-409-3p as Plasma Biomarkers in Gestational Diabetes Mellitus Sharing Validated Target Genes Involved in Metabolic Homeostasis.

Gestational diabetes mellitus (GDM) causes both maternal and fetal adverse outcomes. The deregulation of microRNAs (miRNAs) in GDM suggests their involvement in GDM pathogenesis and complications. Exosomes are extracellular vesicles (EVs) of endosomal origin, released via exocytosis into the extracellular compartment. Through EVs, miRNAs are delivered in distant target cells and are able to affect gene expression. In this study, miRNA expression was analyzed to find new miRNAs that could improve GDM classification and molecular characterization. MiRNA were profiled in total plasma and EVs in GDM patients and normal glucose tolerance (NGT) women. Samples were collected at third trimester of gestation from two diabetes centers. MiRNA expression was profiled in a discovery cohort using the multiplexed NanoString nCounter Human v3 miRNA. Validation analysis was performed in a second independent cohort using RT-qPCR. A set of miRNAs resulted to be differentially expressed (DE) in total plasma and EVs in GDM. Among them, total plasma miR-222-3p and miR-409-3p were validated in the independent cohort. MiR-222-3p levels correlated with fasting plasma glucose (FPG) (p < 0.001) and birth weight (p = 0.012), whereas miR-409-3p expression correlated with FPG (p < 0.001) and inversely with gestational age (p = 0.001). The major validated target genes of the deregulated miRNAs were consistently linked to type 2 diabetes and GDM pathophysiology. MiR-222-3p and miR-409-3p are two circulating biomarkers that could improve GDM classification power and act in the context of the molecular events leading to the metabolic alterations observed in GDM.

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.