Project description:Type 2 diabetes mellitus represents a major health problem with increasing prevalence worldwide. Limited efficacy of current therapies have prompted a search for novel therapeutic options. Here we show that treatment of pre-diabetic mice with mitochondrially targeted tamoxifen, a potential anti-cancer agent with senolytic activity, improves glucose tolerance and reduces body weight with most pronounced reduction of visceral adipose tissue due to reduced food intake, suppressed adipogenesis and elimination of senescent cells. Glucose-lowering effect of mitochondrially targeted tamoxifen is linked to improvement of type 2 diabetes mellitus-related hormones profile and is accompanied by reduced lipid accumulation in liver. Lower senescent cell burden in various tissues, as well as its inhibitory effect on pre-adipocyte differentiation, results in lower level of circulating inflammatory mediators that typically enhance metabolic dysfunction. Targeting senescence with mitochodrially targeted tamoxifen thus represents an approach to the treatment of type 2 diabetes mellitus and its related comorbidities, promising a complex impact on senescence-related pathologies in aging population of patients with type 2 diabetes mellitus with potential translation into the clinic.
Project description:Background/objectivePlasma apoB predicts the incidence of type 2 diabetes (T2D); however, the link between apoB-linpoproteins and risks for T2D remain unclear. Insulin resistance (IR) and compensatory hyperinsulinemia characterize prediabetes, and the involvement of an activated interleukin-1 (IL-1) family, mainly IL-1β and its receptor antagonist (IL-Ra), is well documented. ApoB-lipoproteins were reported to promote IL-1β secretion in immune cells; however, in vivo evidence is lacking. We hypothesized that obese subjects with hyperapoB have an activated IL-1 system that explains hyperinsulinemia and IR in these subjects.Subjects/methodsWe examined 81 well-characterized normoglycemic men and postmenopausal women (⩾27 kg m(-2), 45-74 years, non-smokers, sedentary, free of chronic disease). Insulin secretion and sensitivity were measured by the gold-standard Botnia clamp, which is a combination of a 1-h intravenous glucose tolerance test (IVGTT) followed by 3-h hyperinsulinemic euglycemic clamp.ResultsPlasma IL-1β was near detection limit (0.071-0.216 pg ml(-1)), while IL-1Ra accumulated at 1000-folds higher (77-1068 pg ml(-1)). Plasma apoB (0.34-1.80 g l(-1)) associated significantly with hypersinsulinemia (totalIVGTT: C-peptide r=0.27, insulin r=0.22), IR (M/I=-0.29) and plasma IL-1Ra (r=0.26) but not with IL-1β. Plasma IL-1Ra associated with plasma IL-1β (r=0.40), and more strongly with hyperinsulinemia and IR than apoB, while the association of plasma IL-1β was limited to second phase and total insulin secretion (r=0.23). Adjusting the association of plasma apoB to hyperinsulinemia and IR for IL-1Ra eliminated these associations. Furthermore, despite equivalent body composition, subjects with hyperapoB (⩾80th percentile, 1.14 g l(-1)) had higher C-peptide secretion and lower insulin sensitivity than those with low plasma apoB (⩽20th percentile, 0.78 g l(-1)). Adjustment for plasma IL-1 Ra eliminated all group differences.ConclusionPlasma apoB is associated with hyperinsulinemia and IR in normoglycemic obese subjects, which is eliminated upon adjustment for plasma IL-1Ra. This may implicate the IL-1 family in elevated risks for T2D in obese subjects with hyperapoB.
Project description:Obesity is a chronic and complex disease, with an increasing incidence worldwide that is associated with metabolic disorders such as type 2 diabetes mellitus (T2DM). Thus, it is important to determine the differences between metabolically healthy obese individuals and those with metabolic disorders. The aim of this study was to perform an untargeted metabolomics assay in women with morbid obesity (MO) compared to a normal weight group, and to differentiate the metabolome of these women with MO who present with T2DM. We carried out a liquid chromatography-mass spectrometry-based untargeted metabolomics assay using serum samples of 209 Caucasian women: 73 with normal weight and 136 with MO, of which 71 had T2DM. First, we found increased levels of choline and acylglycerols and lower levels of bile acids, steroids, ceramides, glycosphingolipids, lysophosphatidylcholines, and lysophosphatidylethanolamines in MO women than in the control group. Then, in MO women with T2DM, we found increased levels of glutamate, propionyl-carnitine, bile acids, ceramides, lysophosphatidylcholine 14:0, phosphatidylinositols and phosphoethanolamines, and lower levels of Phe-Ile/Leu. Thus, we found metabolites with opposite trends of concentration in the two metabolomic analyses. These metabolites could be considered possible new factors of study in the pathogenesis of MO and associated T2DM in women.
Project description:Obesity and type 2 diabetes (T2D) remain major global healthcare challenges and developing therapeutics necessitate using nonhuman primate models. Here, we present proteomic analyses of all the major organs of cynomolgus monkeys with spontaneous obesity or T2D in comparison to healthy controls.
Project description:This manuscript provides a brief review of current concepts in the mechanisms potentially linking type-2-diabetes (T2D) with cognitive impairment. Existing epidemiologic studies, imaging studies, autopsy studies, and clinical trials provide insights into the mechanisms linking T2D and cognitive impairment. There seems to be little dispute that T2D can cause cerebrovascular disease and thus cause vascular cognitive impairment (VCI). Whether T2D can cause late onset Alzheimer's disease (LOAD) remains to be elucidated. Many epidemiologic studies show an association between T2D and cognitive impairment, but the association with VCI seems to be stronger compared to LOAD, suggesting that cerebrovascular disease may be the main mechanism linking T2D and cognitive impairment. Imaging studies show an association between T2D and imaging markers of LOAD, but these observations could still be explained by cerebrovascular mechanisms. Autopsy studies are few and conflicting, with some suggesting a predominantly cerebrovascular mechanism, and others providing support for a neurodegenerative mechanism. Thus far, the evidence from clinical trials is mixed in supporting a causal association between T2D and cognitive impairment, and most clinical trials that can answer this question are yet to be reported or finished. Given the epidemic of T2D in the world, it is important to elucidate whether the association between T2D and cognitive impairment, particularly LOAD, is causal, and if so, what the mechanisms are.
Project description:The risk of type 2 diabetes (T2D) increases with obesity. One possible explanation is that pleiotropic genes affect risk of both T2D and obesity. To identify pleiotropic genes, we performed bivariate analysis of T2D with waist-hip ratio (WHR) and with body mass index (BMI) in the African-American subset of the Genetics of NIDDM (GENNID) sample. Of 12 T2D loci identified through suggestive or higher univariate logarithm of the odds ratio (lod) scores, we inferred pleiotropy with obesity for six (chromosomes 1 at 17-19 Mb, 2 at 237-240 Mb, 7 at 54-73 Mb, 13 at 26-30 Mb, 16 at 26-47 Mb and 20 at 56-59 Mb). These findings provide evidence that at least some of the co-occurrence of obesity with T2D is because of pleiotropic genes. We also inferred four obesity loci through suggestive or higher lod scores for WHR (chromosomes 1 at 24-32 Mb, 2 at 79-88 Mb, 2 at 234-238 Mb and 3 at 148-159 Mb).
Project description:Metabolic disorders such as obesity and type 2 diabetes (T2D) are considered the major risk factors for the development of cardiovascular diseases (CVD). Although the pathological mechanisms underlying the mutual development of obesity and T2D are difficult to define, a better understanding of the molecular aspects is of utmost importance to identify novel therapeutic targets. Recently, a class of non-coding RNAs, called microRNAs (miRNAs), are emerging as key modulators of metabolic abnormalities. There is increasing evidence supporting the role of intra- and extracellular miRNAs as determinants of the crosstalk between adipose tissues, liver, skeletal muscle and other organs, triggering the paracrine communication among different tissues. miRNAs may be considered as risk factors for CVD due to their correlation with cardiovascular events, and in particular, may be related to the most prominent risk factors. In this review, we describe the associations observed between miRNAs expression levels and the most common cardiovascular risk factors. Furthermore, we sought to depict the molecular aspect of the interplay between obesity and diabetes, investigating the role of microRNAs in the interorgan crosstalk. Finally, we discussed the fascinating hypothesis of the loss of protective factors, such as antioxidant defense systems regulated by such miRNAs.
Project description:In this project we will investigate the peptides present by HLA-DQ8. We will identify linear, spliced and PTM peptides from one cell line.
Project description:Biased agonism of G protein-coupled receptors (GPCRs) holds great promise for the development of safer medications. Current efforts have explored the balance between heterotrimeric G proteins and the scaffold protein b-arrestin; however, other transducers like GPCR kinases (GRKs) represent important, but understudied mediators of agonist-induced signaling. In particular, GRK2 has been shown to play an essential role in b2 adrenergic receptor (b2AR)-mediated glucose uptake, but b2AR agonists are generally thought to make poor clinical candidates for glycemic management given their potential for Gs/cAMP-induced cardiac side effects and tendency for b-arrestin-dependent desensitization with long-term treatment. For these reasons, we sought to develop pathway-selective agonists of b2AR that prefer GRK coupling to heterotrimeric Gs and b-arrestin. Ligand-based virtual screening and chemical evolution of adrenergic agonists led to the identification of GRK-biased b2AR partial agonists. We demonstrate that these compounds perform well in preclinical models of hyperglycemia and obesity and demonstrate a lower potential for cardiac and muscular side effects compared to standard b2-receptor agonists and incretin mimetics respectively. Furthermore, our lead candidate showed favorable pharmacokinetics and was determined to be safe in a placebo-controlled clinical trial. GRK-biased b2AR partial agonists are thus promising candidates to offer a viable, orally available alternative to injection-based incretin mimetics used in the treatment of type II diabetes and obesity.
Project description:Partial remission (PR) occurs in only half of patients with new-onset type 1 diabetes (T1D) and correspond to a transient period characterized by low daily insulin needs, low glycemic fluctuations and increased endogenous insulin secretion. While identification of newly-onset T1D patients with significant residual beta-cell function may foster patient-specific interventions, reliable predictive biomarkers of PR occurrence currently lack. We analyzed the plasma of children with new-onset T1D to identify biomarkers present at diagnosis that predicted PR at 3 months post-diagnosis. We first performed an extensive shotgun proteomic analysis using Liquid Chromatography-Tandem-Mass-Spectrometry (LCMS/MS) on the plasma of 16 children with new-onset T1D and quantified nearly 1500 unique proteins with 98 significantly correlating with Insulin-Dose Adjusted glycated hemoglobin A1c score (IDAA1C). We next applied a series of both qualitative and statistical filters that yielded to the selection of 26 protein candidates that were associated to pathophysiological mechanisms related to T1D. Finally, we translationally validated several of the candidates using single-shot targeted proteomic (PRM method) on raw plasma. Taken together, we identified plasmatic biomarkers present at diagnosis that may predict the occurrence of PR in a single mass-spectrometry run. We believe that the identification of new predictive biomarkers of PR and β-cell function is key to stratify patients with new-onset T1D for β-cell preservation therapies