Increased intestinal permeability has been implicated in metabolic dysfunction-associated steatotic liver disease (MASLD), but its relationship with liver fibrosis independent of metabolic risk factors remains unclear. The aim of this study was to investigate the relationship between markers of gut-derived immune activation and liver fibrosis in individuals with metabolic disease. We enrolled 139 adults (48.8 ± 11 years; BMI 33.7 ± 9.5 kg/m2; 50% type 2 diabetes); liver steatosis and fibrosis were estimated using the Hepatic Steatosis Index (HSI) and Fibrotic NASH Index (FNI); liver biopsies were available in a bariatric subgroup. Plasma soluble CD14 (sCD14) and lipopolysaccharide-binding protein (LBP) levels were measured by ELISA kits, and the LBP/sCD14 ratio was calculated. MASLD was present in 78% of participants; in these individuals, sCD14 levels correlated with HSI and FNI (both p < 0.01). In multivariable analysis adjusting for age, sex, BMI, waist circumference, and type 2 diabetes, sCD14 was independently associated with advanced fibrosis (OR: 3.16, 95% CI 1.32-7.55; p = 0.010). This association was confirmed by histology (p = 0.02). Overall, these findings point to a link between gut-derived immune activation and fibrotic burden in MASLD and provide insight into the pathophysiological relevance of the gut-liver axis in metabolic disease.

Background: Oral semaglutide, a GLP1-receptor agonist (GLP1-RA), shows promise in efficacy and compliance, especially amid the global shortage of injectable GLP-1 RAs. Its short-term effectiveness remains unexplored. Objective: This real-world observational study assessed the short-term effectiveness of oral semaglutide after three months of therapy. Methods: Patients with type 2 diabetes from four Italian diabetes centers, who received an initial prescription of oral semaglutide, were reassessed after three months. Primary outcomes included glycated hemoglobin (HbA1c) and body weight reduction; secondary outcomes involved changes in lipid parameters and cardiovascular risk. Results: Among 167 participants (mean age 66.5 years, mostly obese, baseline HbA1c 8.4% ± 1.5), 83.2% received a 7 mg dose. After three months, HbA1c significantly declined (8.4% to 7.1%, -1.3%, p < 0.001), alongside body mass index (BMI) (30.9 kg/m2 to 29.6 kg/m2, p < 0.0001). The target HbA1c ≤ 7% was achieved by 54.5%, and 34.7% reached ≤6.5%. Patients losing >5% of their initial weight (30.5%) saw the largest HbA1c drop (-1.9%). Those with newly diagnosed diabetes or a duration < 5 years showed superior responses (p = 0.001), while no significant differences were found based on the timing of drug administration. Oral semaglutide replaced or supplemented prior therapies, allowing discontinuation of dipeptidyl peptidase 4 inhibitors (DPP4i), sulfonylureas, glinides, and acarbose, and deprescription of thiazolidinediones. A significant reduction in cardiovascular risk was observed (p = 0.04), together with a significant reduction in lipid parameters. Conclusions: Oral semaglutide showed significant short-term efficacy, reducing HbA1c, body weight, and cardiovascular risk in three months, making it a valuable therapeutic option.

Obesity-associated adipose tissue dysfunction represents a key driver of metabolic disorders, including type 2 diabetes, cardiovascular diseases, and fatty liver disease. Emerging evidence highlights the vitamin D/vitamin D receptor (VD/VDR) axis as an important regulator of adipose tissue homeostasis. Beyond its classical role in mineral metabolism, vitamin D influences adipogenesis, inflammation, and insulin sensitivity, thereby modulating systemic metabolic health. In this review, we summarize the current understanding of the VD/VDR axis in adipose tissue biology, from molecular pathways controlling lipid turnover and immune responses to experimental and clinical evidence linking vitamin D status with obesity-related complications. We also discuss the role of genetic variability and tissue-specific VDR signaling in shaping metabolic outcomes. While results from supplementation trials remain inconsistent, maintaining adequate vitamin D levels appears crucial for the prevention of adipose tissue dysfunction and its cardiometabolic consequences. Future studies are warranted to define optimal strategies for harnessing the VD/VDR axis in therapeutic approaches to obesity and metabolic disease.

Metabolic-associated steatotic liver disease (MASLD) represents the most common chronic hepatopathy worldwide and an independent risk factor for cardiovascular disease and mortality, particularly when liver fibrosis occurs. Epigenetic alterations, such as DNA methylation, may influence MASLD susceptibility and progression; yet mechanisms underlying this process are limited. This study aimed to investigate whether active DNA demethylation in peripheral blood mononuclear cells (PBMCs) from individuals with MASLD, alongside the methylation and mRNA levels of inflammation- and fibrosis-related candidate genes, is associated with liver fibrosis. For this study, global demethylation intermediates (5-hydroxymethylcytosine [5hmC], 5-formylcytosine [5fC]) were quantified in PBMCs from 89 individuals with/without MASLD using ELISA. Site-specific DNA methylation of SOCS3, SREBF1, and TXNIP was analyzed by mass spectrometry-based bisulfite sequencing; mRNA expression was assessed via RT-PCR. Individuals with MASLD and moderate-to-high fibrosis risk (estimated by the fibrosis non-alcoholic steatohepatitis (NASH) index, FNI) progressively exhibited greater global 5hmC and 5fC levels. Higher FNI was associated with reduced methylation of the SOCS3 gene and increased mRNA expression of the SOCS3, TXNIP, IL-6, and MCP-1 genes. In conclusion, elevated fibrosis risk in MASLD is associated with active global DNA demethylation, as well as differential methylation and expression patterns of genes, which are key regulators of inflammation and fibrosis. These epigenetic alterations in PBMCs may mirror DNA methylation changes in the liver, which may potentially contribute to liver fibrogenesis and represent novel biomarkers for MASLD progression toward fibrosis.

CONTEXT:The mechanisms underlying bone fragility and increased fracture risk observed in individuals with type 2 diabetes (T2D) are not yet fully elucidated. Previous research has suggested a role for neuropeptides in regulating bone metabolism; however, the contribution of the neuropeptide Neurotensin (NT), which is thoroughly implicated in T2D and cardiovascular disease, has not been investigated in this context. OBJECTIVE:To study the relationship between circulating levels of the NT precursor proneurotensin (proNT) and bone mineralisation in T2D women. MATERIALS AND METHODS:This is a cross-sectional investigation with a longitudinal prospective phase, involving 126 women with T2D who underwent bone density scans and had proNT levels measured. Biomarkers of bone metabolism and inflammation were also assessed. Data on bone mineral density (BMD) after 12 months were available for 49 patients. MAIN OUTCOME MEASURE:Plasma proNT levels in relation to BMD. RESULTS:32% of the participants had osteopenia/osteoporosis and exhibited higher proNT than those with normal BMD (200.8 ± 113.7 vs. 161.6 ± 108.8 pg/mL; p = 0.013). ProNT inversely correlated with femur BMD and T-score (p < 0.01) and was associated with degraded bone architecture (TBS, p = 0.02), and higher OPN, P1NP, TNF-α and IL-1β levels. Baseline proNT correlated with further BMD reduction at the 12-month follow-up, independently of potential confounders (p = 0.02). CONCLUSIONS:In women with T2D, greater proNT levels are associated with impaired bone mineralisation and predict mineral density decline overtime. ProNT could potentially serve as a diagnostic tool for identifying patients at higher risk of osteopenia/osteoporosis, suggesting a significant connection between this neuropeptide and bone metabolism in diabetes.

Women with type 2 diabetes have an increased risk of bone fragility and fractures. Experimental models suggest that dipeptidyl peptidase-4 inhibitors (DPP4-Is) may have protective effects on bone, but clinical data remain limited, and randomized trials targeting bone Outcomes are lacking. This study aimed to evaluate the efficacy and safety of 52 weeks of oral sitagliptin treatment in improving bone Outcomes in women with type 2 diabetes. This multicenter, phase III, superiority, double-blind, randomized, placebo-controlled trial enrolled 132 women with type 2 diabetes in monotherapy with metformin and stable glycemic control. Participants were recruited from diabetes Outpatient clinics at Sapienza University of Rome, Italy, and were randomly assigned to receive sitagliptin or placebo for 52 weeks. The main outcome was a change in bone mineral density (BMD) and bone turnover biomarkers. Both intention-to-treat (ITT) and per-protocol (PP) analyses were conducted. Treatment with sitagliptin preserved the total proximal femur BMD T score over 52 weeks (estimated mean difference: − 0.02; 95

The adaptor protein p66Shc regulates oxidative stress and aging, but its role in renal aging is unclear. We investigated the effects of p66Shc deletion on age-related kidney changes, focusing on G protein-coupled receptor 124 (GPR124) and cellular senescence. Using kidney and urine samples from p66Shc-/- and wild-type mice aged 5-24 months, we found that p66Shc deficiency slows renal aging. Compared to wild-type mice, p66Shc-/- mice showed better kidney function and reduced glomerular sclerosis and mesangial expansion from 18 months, alongside attenuated fibrosis, oxidative stress, and podocyte loss. Age-related declines in GPR124 were also smaller in p66Shc-/- mice, correlating with lower p16INK4a levels in glomeruli and cultured podocytes. These findings suggest that p66Shc deletion provides kidney protection by limiting oxidative stress and senescence, potentially through the preservation of GPR124. This study links p66Shc to natural kidney aging and identifies GPR124 as a mediator of p66Shc-driven senescence, suggesting potential targets for interventions in age-related renal decline.

BackgroundOsteoporosis and metabolic syndrome (MetS) are conditions associated with ageing and chronic inflammation; among MetS’ components, visceral obesity has been correlated to low bone mineral density in postmenopausal women. However, data on an increased fracture risk in MetS are still contrasting. The trabecular bone score (TBS) is an indicator of bone quality and a potential predictive factor for fractures. We aim to explore the relationship between MetS components and TBS.Methodswe analyzed data from 3962 women in the 2005-2006 and 2007-2008 NHANES cohorts, for whom a valid TBS value was available. All analyses were adjusted for the principal risk factors of altered bone metabolism.ResultsAn inverse significant association was observed between TBS and most of the MetS variables investigated, with the strongest correlation found with waist circumference (WC) (P <0.001). WC represented the major predictor of degraded TBS (P <0.001), in adjusted models considering age, 25(OH)Vitamin D, smoke and insulin resistance. Increased WC was significantly associated with the presence of bone fractures at the logistic regression analysis (P = 0.001) in all study participants and in the subgroup of women ≤50 years old after adjustment for potential confounders (P = 0.006).ConclusionThis study, using a large sample of women, found a negative association of MetS on bone health, mainly driven by visceral obesity.

The (pro)renin receptor ((P)RR), a versatile protein found in various organs, including the kidney, is implicated in cardiometabolic conditions like diabetes, hypertension, and dyslipidemia, potentially contributing to organ damage. Importantly, changes in (pro)renin/(P)RR system localization during renal injury, a critical information base, remain unexplored. This study investigates the expression and topographic localization of the full length (FL)-(P)RR, its ligands (renin and prorenin), and its target cyclooxygenase-2 and found that they are upregulated in three distinct animal models of renal injury. The protein expression of these targets, initially confined to specific tubular renal cell types in control animals, increases in renal injury models, extending to glomerular cells. (P)RR gene expression correlates with protein changes in a genetic model of focal and segmental glomerulosclerosis. However, in diabetic and high-fat-fed mice, (P)RR mRNA levels contradict FL-(P)RR immunoreactivity. Research on diabetic mice kidneys and human podocytes exposed to diabetic glucose levels suggests that this inconsistency may result from disrupted intracellular (P)RR processing, likely due to increased Munc18-1 interacting protein 3. It follows that changes in FL-(P)RR cellular content mechanisms are specific to renal disease etiology, emphasizing the need for consideration in future studies exploring this receptor’s involvement in renal damage of different origins.

Neurotensin (NT) is a small protein implicated in the regulation of energy balance which acts as both a neurotransmitter in the central nervous system and as a gastrointestinal peptide. In the gut, NT is secreted after fat ingestion and promotes the absorption of fatty acids. The circulating levels of its precursor, pro-NT, predicts the presence and development of metabolic and cardiovascular diseases. Despite the extensive knowledge on the dynamic changes that occur to pro-NT = after fat load, the determinants of fasting pro-NT are unknown. The aim of this study was to determine the possible genetic regulation of plasma pro-NT. The NT gene (NTS) was sequenced for potential functional variants, evaluating its entire genomic and potentially regulatory regions, in DNA from 28 individuals, stratified by low and high pro-NT levels. The identified variant differently distributed in the two pro-NT subgroups was genotyped in a cohort of nine hundred and thirty-two overweight/obese children and adolescents. A total of seven sequence variations across the NTS gene, none of them located in coding regions, were identified. The rs2234762 polymorphism, sited in the NTS gene promoter, was statistically more frequent in the lowest pro-NTS level group. Carriers of the rs2234762 variant showed lower pro-NT levels, after adjusting for sex, age, BMI, triglycerides and the Tanner stage. Having NTS rs2234762 predicted less pronounced insulin resistance at the 6.5-year follow-up with OR: 0.46 (0.216–0.983), at the logistic regression analysis adjusted for age, sex and BMI. In conclusion, the NTS rs2234762 gene variant is a determinant of reduced circulating pro-NT levels in overweight and obese children, which predisposes this group to a more favorable metabolic profile and a reduced insulin resistance later in life, independently from metabolic confounders.

Lipopolysaccharide (LPS) and its binding protein LBP have emerged as potential contributors to the progression from overweight/obesity to overt metabolic diseases and NAFLD. While LPS is known to activate hepatocyte inflammation, thus contributing toward NAFLD development, the role of LBP is more intricate, and recent data have shown that experimental reduction in hepatic LBP promotes NAFLD progression. In this cross-sectional investigation, we evaluated circulating LBP in relation to obesity, NAFLD, visceral adipose tissue (VAT) inflammation, and type 2 diabetes (T2D). We recruited 186 individuals (M/F: 81/105; age: 47 ± 10.4 years; BMI: 35.5 ± 8.6 kg/m2); a subgroup (n = 81) underwent bariatric surgery with intra-operative VAT and liver biopsies. LBP levels were higher in obese individuals than non-obese individuals but were inversely correlated with the parameters of glucose metabolism. Reduced LBP predicted T2D independent of age, sex, and BMI (p < 0.001). LBP levels decreased across more severe stages of hepatosteatosis and lobular inflammation, and were inversely associated with VAT inflammation signatures. In conclusion, LBP levels are increased in obese individuals and are associated with a more favorable metabolic profile and lower NAFLD/NASH prevalence. A possible explanation for these findings is that hepatic LBP production may be triggered by chronic caloric excess and facilitate LPS degradation in the liver, thus protecting these individuals from the metabolic consequences of obesity.

Type 2 diabetes is characterized by impairment in insulin secretion, with an established genetic contribution. We aimed to evaluate common and low-frequency (1–5%) variants in nine genes strongly associated with insulin secretion by targeted sequencing in subjects selected from the extremes of insulin release measured by the disposition index. Collapsing data by gene and/or function, the association between disposition index and nonsense variants were significant, also after adjustment for confounding factors (OR = 0.25, 95% CI = 0.11–0.59, p = 0.001). Evaluating variants individually, three novel variants in ARAP1, IGF2BP2 and GCK, out of eight reaching significance singularly, remained associated after adjustment. Constructing a genetic risk model combining the effects of the three variants, only carriers of the ARAP1 and IGF2BP2 variants were significantly associated with a reduced probability to be in the lower, worst, extreme of insulin secretion (OR = 0.223, 95% CI = 0.105–0.473, p < 0.001). Observing a high number of normal glucose tolerance between carriers, a regression posthoc analysis was performed. Carriers of genetic risk model variants had higher probability to be normoglycemic, also after adjustment (OR = 2.411, 95% CI = 1.136–5.116, p = 0.022). Thus, in our southern European cohort, nonsense variants in all nine candidate genes showed association with better insulin secretion adjusted for insulin resistance, and we established the role of ARAP1 and IGF2BP2 in modulating insulin secretion.

Purpose To investigate the relationship between the single-point insulin sensitivity estimator (SPISE) index, an insulin sensitivity indicator validated in adolescents and adults, and metabolic profile in overweight/obese children, and to evaluate whether basal SPISE is predictive of impaired glucose regulation (IGR) development later in life. Methods The SPISE index (= 600 × HDL 0.185 /Triglycerides 0.2 × BMI 1.338 ) was calculated in 909 overweight/obese children undergoing metabolic evaluations at University of Cagliari, Italy, and in 99 normal-weight, age-, sex-comparable children, selected as a reference group, together with other insulin-derived indicators of insulin sensitivity/resistance. 200 overweight/obese children were followed-up for 6.5 [3.5–10] years, data were used for longitudinal retrospective investigations. Results At baseline, 96/909 (11%) overweight/obese children had IGR; in this subgroup, SPISE was significantly lower than in normo-glycaemic youths (6.3 ± 1.7 vs. 7 ± 1.6, p < 0.001). The SPISE index correlated positively with the insulin sensitivity index (ISI) and the disposition index (DI), negatively with age, blood pressure, HOMA-IR, basal and 120 min blood glucose and insulin (all p values < 0.001). A correlation between SPISE, HOMA-IR and ISI was also reported in normal-weight children. At the 6.5-year follow-up, lower basal SPISE—but not ISI or HOMA-IR—was an independent predictor of IGR development (OR = 3.89(1.65–9.13), p = 0.002; AUROC: 0.82(0.72–0.92), p < 0.001). Conclusion In children, low SPISE index is significantly associated with metabolic abnormalities and predicts the development of IGR in life.

Recently ANK2, encoding ankyrin-B (AnkB), has been proposed as an obesity susceptibility gene. AnKB negatively regulates the expression of glucose transporter 4 (GLUT4) in adipocytes, and it has been hypothesized that functional alterations of AnkB may determine the persistence of GLUT4 on the cell surface, increasing glucose transport in adipocytes. Adipose tissue-specific AnkB-KO mice develop obesity and progressive pancreatic islet dysfunction with age or high-fat diet. AnkB-deficient adipocytes exhibit increased lipid accumulation associated with increased glucose uptake and impaired endocytosis of GLUT4. Functional alterations have been observed in ANK2 gene in European Americans and African Americans and have been proposed as candidates to contribute to obesity susceptibility in humans. Considering that variants of ANK2 gene were previously observed in subjects of American and African American ethnicity, and that these variants were never studied in association with obesity, we performed a genetic association analysis with obesity in a cohort of Southern European subjects. For this study 1900 Italian subjects with body mass index (BMI) between 16 and 91 were selected. All subjects underwent clinical examination, anthropometric measurements and routine laboratory tests. The SNPs rs45454496 (E1813K) and rs35530544 (L1622I) have been studied in DNAs by Eco TM Real-Time PCR System by Illumina. Among the 1900 subjects we identified 15 (frequency 0.7%) heterozygous subjects for the rs45454496 variant and no homozygous subject. The observed frequency in our population is more than double that observed in other populations of European origin (0.7% vs 0.3%, p = 0.3). We then analysed the association between this polymorphism and clinical and biochemical characteristics. Carriers of the mutation showed no significantly differences compared to wild-type subjects in any of the parameters examined. Population stratification by BMI showed a random distribution of the rs45454496 variant according to weight. Also, population stratification based on glycaemic alterations showed no association of the rs45454496 variant with categories of glucose metabolism. Finally, we analysed the study cohort for the rs35530544, but we did not observe any subject carrying the variant in an initial sample of 840 patients. In conclusion, we observed that the rs45454496 (E1813K) variant of ANK2 gene, although showing a higher frequency in our Southern European population (0.7%) than the frequencies reported in other populations of European origin, in the analysed sample does not seem to have effects on clinical and metabolic alterations.

Background and aims: Neurotensin (NT) is an intestinal peptide released after fat ingestion, which regulates appetite and facilitates lipid absorption. Elevated plasma levels of its stable precursor pro-neurotensin (pro-NT) are associated with type 2 diabetes, obesity and cardiovascular mortality in adult populations; no data on pro-NT and metabolic disease are available in children. Aim of the study was to evaluate plasma pro-NT in relation to the presence of obesity in children, and to test if high pro-NT associates with the development of metabolic impairment later in life. Methods and results: For this longitudinal retrospective study, we studied 151 overweight/obese children undergoing metabolic evaluations at University of Cagliari, Italy. Pro-NT was also assessed in 46 normal-weight, age-, sex-comparable normal-weight children, selected as a reference group. At the baseline, pro-NT was comparable between overweight/obese and normal-weight children and correlated positively with age (p < 0.001), triglycerides (p < 0.001) and inversely with HDL levels (p = 0.008). Plasma pro-NT associated with high triglycerides with OR = 5.9 (95%CI: 1.24-28.1; p = 0.026) after adjustment for multiple confounders. At the 6.5-year follow-up, high basal pro-NT associated with impaired beta-cell function to compensate for insulin-resistance (disposition index: r = -0.19, p = 0.035) and predicted bodyweight increase, as indicated by percentage change of standard deviation score BMI (median(95%CI) = +20.8(+4.9-+27.5)% in the highest tertile), independently from age, sex, triglycerides and insulin-resistance (standardized beta = 0.24; p = 0.036). Conclusions: Elevated pro-NT levels in children are significantly associated with weight gain later in life and may represent a marker of susceptibility to metabolic impairment in presence of obesity. (C) 2020 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Introduction Dipeptidyl peptidase 4 (DPP4) levels are associated to metabolic and cardiovascular diseases in humans; initial evidence reported a relationship between DPP4 and chronic liver diseases. Aim of this study was to investigate hepatic and systemic DPP4 levels/activity in relation to NAFLD/NASH in individuals with and without metabolic disease. Methods We recruited fifty-two obese individuals undergoing bariatric surgery and intra-operative liver biopsy at Sapienza University, Rome, Italy. The association between DPP4 levels/activity and NAFLD was also evaluated in 126 non-obese individuals recruited in the same setting. Results NAFLD patients had significantly higher circulating DPP4 activity than no-NAFLD in both the obese and non-obese cohorts; plasma DPP4 activity and levels linearly correlated with steatosis grade and inflammation at the liver biopsy. Hepatic DPP4 mRNA was not associated to either its circulating levels/activity or NAFLD. In the multivariate logistic regression analysis on all the study participants ( n = 178), higher circulating DPP4 activity was associated with NAFLD independently of potential confounders with OR (95% CI): 3.5 (1.2–10.21), p = 0.022. Conclusions This study demonstrates the coexistence of increased plasma DPP4 levels and activity in NAFLD. Circulating DPP4 measurement may represent a novel cost-effective strategy for NAFLD/NASH risk stratification and a potential tool for monitoring disease’s progression in established NAFLD.

Background Obesity in youth is associated with increased risk of metabolic disorders. Adipose tissue hormones are involved in body-weight regulation. Among these, apelin is recognized as an insulin-sensitizer adipokine. Data on apelin levels in obese children and its relation to insulin-sensitivity are limited. Objective We aimed to evaluate apelin levels in relation to obesity and insulin sensitivity in a large cohort of overweight/obese children and adolescents. Furthermore, these youths were reevaluated after a median 6.5 years of follow-up, thus allowing assessing changes in apelin levels in relation to increasing age and weight changes. Methods Clinical data in 909 children and adolescents were collected between 2007 and 2010. Two hundred and one were reexamined at a median 6.5 years of follow-up. All subjects at baseline and at follow-up underwent an OGTT. Apelin levels were measured on sera by ELISA method. Results At baseline, lower apelin levels were associated with increasing age and puberty (Tanner >= II 0.67 +/- 0.96 ng/mL vs. Tanner I 0.89 +/- 1.13 ng/mL,p< .002), but not with body-weight. At follow-up, apelin levels in the 201 subjects reexamined were significantly lower than at baseline (0.45 +/- 0.77 ng/mL at follow-up, 0.68 +/- 0.95 ng/mL baseline,p< .001), confirming the effects of age and puberty. Body-weight did not affect apelin levels. Multiple regression analysis confirmed that sex and puberty were associated with lower apelin levels, independently from age and insulin-sensitivity. Conclusions Apelin levels decrease significantly with pubertal development, whilst body-weight in children and adolescents did not determine changes in apelin. Reduced levels of apelin in children and adolescents may therefore represent a necessary response to maintain the "physiological" insulin resistance of puberty.

Granzyme B (GrB) is a serine protease produced by immune and non-immune cells, able to promote multiple processes, like apoptosis, inflammation, extracellular matrix remodeling and fibrosis. GrB expression in visceral adipose tissue (VAT) was associated with tissue damage, local inflammation and insulin resistance in obesity murine model, but there is no data in humans. Aim of this study was to explore the expression of GrB in VAT from obese subjects in relation to adipose tissue injury, inflammation, metabolic alterations and GrB circulating levels. For this purpose, 85 obese individuals undergoing bariatric surgery and 35 healthy subjects (as control) were recruited at Sapienza University, Rome, Italy. Study participants underwent clinical work-up and routine biochemistry. mRNA expression of GrB in VAT and of a panel of VAT inflammatory markers was analyzed by real-time PCR. Serum GrB levels were measured by Elisa Affymetrix EBIO. We observed that 80% of obese patients expressed GrB mRNA in VAT, and GrB VAT expression was associated with the presence of local inflammation and glucose homeostasis alterations. Moreover, GrB serum levels, which were higher in obese subjects compared to non-obese healthy individuals, were associated with GrB expression in VAT and glyco-metabolic impairment. Our data show, for the first time in humans, that obese subjects with “sick” fat and altered glucose tolerance exhibit GrB expression in VAT, and suggest that GrB might contribute to obesity-related VAT inflammatory remodeling and glucose homeostasis dysregulation. Moreover, increased circulating GrB levels might represent a possible peripheral marker of VAT dysfunction in metabolic diseases.

Background and aim: Dipeptidyl peptidase 4 (DPP4) is a key enzyme involved in the regulation of the incretin system exerted by cleaving the glucagon-like peptide 1 (GLP-1); the blockage of DPP4, exerted by the antidiabetic agents DPP4-inhibitors (DPP4-I), results in greater GLP-1 concentration and improved glycaemic control. DPP4 acts also as a pro-inflammatory molecule and mediates vascular damage in experimental models. The relationship between DPP4 activity and endothelial function in diabetes has not been explored yet. Aim of this study was to investigate systemic plasma DPP4 activity in relation to endothelial function in patients with type 2 diabetes mellitus (T2DM). Methods and results: Sixty-two T2DM individuals were recruited in our Diabetes outpatient clinics, Sapienza University, Rome, Italy. All participants underwent complete clinical work-up; endothelial function was evaluated by flow-mediated dilatation (FMD) test; plasma DPP4 activity was assessed by measuring the 7-amino-4-methylcoumarin (AMC) cleavage rate from the synthetic substrate H-glycyl-prolyl-AMC and compared with DPP4 activity measured in sixty-two age-, sex-, BMI-matched non-diabetic subjects. Patients with T2DM had significantly higher DPP4 activity than non-diabetic individuals (211,466 +/- 87657 vs 158,087 +/- 60267 nmol/min/ml, p < 0.001); in T2DM patients, greater DPP4 activity significantly correlated with lower FMD whereas was not associated with BMI and metabolic control. Greater systemic DPP4 activity was an independent predictor of reduced FMD after adjusting for age, gender and other confounders. Conclusions: Circulating DPP4 activity is increased in individuals with T2DM and associated with signs of endothelial dysfunction such as impaired FMD. DPP4 may negatively affect endothelial function through mechanisms beyond glucose homeostasis and metabolic control. (C) 2019 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.