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Producción Científica, Aims/hypothesis Type 2 diabetes is characterised by hyperglucagonaemia and perturbed function of pancreatic glucagon secreting alpha cells but the molecular mechanisms contributing to these phenotypes are poorly understood. Insulin-degrading enzyme (IDE) is present within all islet cells, mostly in alpha cells, in both mice and humans. Furthermore, IDE can degrade glucagon as well as insulin, suggesting that IDE may play an important role in alpha cell function in vivo. Methods We have generated and characterised a novel mouse model with alpha cell-specific deletion of Ide, the A-IDE-KO mouse line. Glucose metabolism and glucagon secretion in vivo was characterised; isolated islets were tested for glucagon and insulin secretion; alpha cell mass, alpha cell proliferation and α-synuclein levels were determined in pancreas sections by immunostaining. Results Targeted deletion of Ide exclusively in alpha cells triggers hyperglucagonaemia and alpha cell hyperplasia, resulting in elevated constitutive glucagon secretion. The hyperglucagonaemia is attributable in part to dysregulation of glucagon secretion, specifically an impaired ability of IDE-deficient alpha cells to suppress glucagon release in the presence of high glucose or insulin. IDE deficiency also leads to α-synuclein aggregation in alpha cells, which may contribute to impaired glucagon secretion via cytoskeletal dysfunction. We showed further that IDE deficiency triggers impairments in cilia formation, inducing alpha cell hyperplasia and possibly also contributing to dysregulated glucagon secretion and hyperglucagonaemia. Conclusions/interpretation We propose that loss of IDE function in alpha cells contributes to hyperglucagonaemia in type 2 diabetes, Ministerio de Economía, Industria y Competitividad (SAF2016-77871-C2-1-R to IC and BFU2016-77125-R to IQ), Ministerio de Ciencia, Innovación y Universidades (PID2019-110496RB-C21 to IC and PID2019-110496RB-C22 to GP), La Caixa Foundation (grant LCF/PR/PR18/51130007 to GP), National Institutes of Health from USA (GM115617), Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCLE

Producción Científica, Insulin-degrading enzyme (IDE) is a highly conserved and ubiquitously expressed Zn2+-metallopeptidase that regulates hepatic insulin sensitivity, albeit its regulation in response to the fasting-to-postprandial transition is poorly understood. In this work, we studied the regulation of IDE mRNA and protein levels as well as its proteolytic activity in the liver, skeletal muscle, and kidneys under fasting (18 h) and refeeding (30 min and 3 h) conditions, in mice fed a standard (SD) or high-fat (HFD) diets. In the liver of mice fed an HFD, fasting reduced IDE protein levels (~30%); whereas refeeding increased its activity (~45%) in both mice fed an SD and HFD. Likewise, IDE protein levels were reduced in the skeletal muscle (~30%) of mice fed an HFD during the fasting state. Circulating lactate concentrations directly correlated with hepatic IDE activity and protein levels. Of note, L-lactate in liver lysates augmented IDE activity in a dose-dependent manner. Additionally, IDE protein levels in liver and muscle tissues, but not its activity, inversely correlated (R2 = 0.3734 and 0.2951, respectively; p < 0.01) with a surrogate marker of insulin resistance (HOMA index). Finally, a multivariate analysis suggests that circulating insulin, glucose, non-esterified fatty acids, and lactate levels might be important in regulating IDE in liver and muscle tissues. Our results highlight that the nutritional regulation of IDE in liver and skeletal muscle is more complex than previously expected in mice, and that fasting/refeeding does not strongly influence the regulation of renal IDE, Ministerio de Economía, Industria y Competitividad (SAF2016-77871-C2-1-R y SAF2016-77871-C2-2-R), Ministerio de Ciencia e Innovación (PID2019-110496RB-C21 y PID2019-110496RB-C22), Junta de Castilla y León (CLU-2019-02), Fundación “la Caixa” (LCF/PR/PR18/51130007)

The vast majority of type 1 diabetes (T1D) genetic association signals lie in noncoding regions of the human genome. Many have been predicted to affect the expression and secondary structure of long noncoding RNAs (lncRNAs), but the contribution of these lncRNAs to the pathogenesis of T1D remains to be clarified. Here, we performed a complete functional characterization of a lncRNA that harbors a single nucleotide polymorphism (SNP) associated with T1D, namely, Lnc13. Human pancreatic islets harboring the T1D-associated SNP risk genotype in Lnc13 (rs917997*CC) showed higher STAT1 expression than islets harboring the heterozygous genotype (rs917997*CT). Up-regulation of Lnc13 in pancreatic β-cells increased activation of the proinflammatory STAT1 pathway, which correlated with increased production of chemokines in an allele-specific manner. In a mirror image, Lnc13 gene disruption in β-cells partially counteracts polyinosinic-polycytidylic acid (PIC)-induced STAT1 and proinflammatory chemokine expression. Furthermore, we observed that PIC, a viral mimetic, induces Lnc13 translocation from the nucleus to the cytoplasm promoting the interaction of STAT1 mRNA with (poly[rC] binding protein 2) (PCBP2). Interestingly, Lnc13-PCBP2 interaction regulates the stability of the STAT1 mRNA, sustaining inflammation in β-cells in an allele-specific manner. Our results show that the T1D-associated Lnc13 may contribute to the pathogenesis of T1D by increasing pancreatic β-cell inflammation. These findings provide information on the molecular mechanisms by which disease-associated SNPs in lncRNAs influence disease pathogenesis and open the door to the development of diagnostic and therapeutic approaches based on lncRNA targeting., This work was supported by a Research Project Grant from the Basque Department of Health (2015111068) and a Research Grant from Fundación de la Sociedad Española de Diabetes (FSED) to I.S. I.G.-M. and A.O.-G. were supported by Predoctoral Fellowship Grants from the UPV/EHU (Universidad del Pais Vasco/Euskal Herriko Unibertsitatea) and the Basque Department of Education, respectively. A.C.-R. was funded by a Grant from the Spanish Ministry of Science, Innovation and Universities (PGC2018-097573-A-I00). D.L.E. received support from the Fonds National de la Recherche 420 Scientifique (FNRS), Welbio Grant CR-2015A-06. B.R.G. was funded by the Spanish Ministry of Science, Innovation and Universities; the European Fund for Regional Development (FEDER) (Grant BFU2017-83588-P); and the Juvenile Diabetes Research Foundation (Grants 17-2013-372 and 2-SRA-2019-837-S-B).

Epicardial adipose tissue (EAT) is a metabolically active tissue intimately associated with metabolic syndrome and cardiovascular disease. Quantification of EAT volume is an interesting clinical tool for the evaluation of cardiometabolic disease. Nevertheless, current methodology presents serious disadvantages. The soluble form of the receptor LRP1 (sLRP1) is a non-invasive biomarker of EAT in general population. Here, we analysed the potential of circulating sLRP1 as biomarker of EAT volume in patients with type 1 diabetes mellitus (T1DM). The study included a well-characterized cohort of T1DM patients without clinical cardiovascular disease (N = 73). EAT volume was assessed by a multidetector computed tomography (MDCT). sLRP1 and panel of inflammatory and endocrine mediators were measured using commercially available ELISA. EAT volume showed a direct association with circulating sLRP1 (β = 0.398, P = 0.001) in univariate linear regression analysis. This association was higher than that observed for other potential inflammatory and endocrine biomarkers. Using multivariate linear regression analyses, we demonstrated that the association between EAT volume and circulating sLRP1 was independent of potential confounding factors, including age, sex, body mass index, CRP, HbA1c and LDL-C (P, Tis work was supported by FIS PI14/01729 and FIS PI13/00364 from the Instituto Salud Carlos III, co-fnanced by the European Fund for Regional Development (E.F.R.D), Fundació Marató TV3 (201521 10) and Ayudas Sociedad Española de Diabetes (SED) de Investigación Básica y Clínica en Diabetes 2011. CIBER Cardiovascular (CB16/11/00403) and CIBERDEM (CB07/08/0016) are Instituto de Salud Carlos III Projects. DdG-C was a recipient of a Sara Borrell grant from the Instituto de Salud Carlos III (CD14/00109). AR-U, MP-C and JLS-Q are members of the Quality Research Group 2014-SGR-0246 and VLL-C, DdG-C are members of the Quality Research Group 2014-SGR-00170 from Generalitat de Catalunya.

This article belongs to the Special Issue Marine Compounds and Inflammation II, 2017., Type 2 diabetes (T2DM) is a complex disease linked to pancreatic beta-cell failure and insulin resistance. Current antidiabetic treatment regimens for T2DM include insulin sensitizers and insulin secretagogues. We have previously demonstrated that leptolide, a member of the furanocembranolides family, promotes pancreatic beta-cell proliferation in mice. Considering the beneficial effects of leptolide in diabetic mice, in this study, we aimed to address the capability of leptolide to improve insulin resistance associated with the pathology of obesity. To this end, we tested the hypothesis that leptolide should protect against fatty acid-induced insulin resistance in hepatocytes. In a time-dependent manner, leptolide (0.1 µM) augmented insulin-stimulated phosphorylation of protein kinase B (PKB) by two-fold above vehicle-treated HepG2 cells. In addition, leptolide (0.1 µM) counteracted palmitate-induced insulin resistance by augmenting by four-fold insulin-stimulated phosphorylation of PKB in HepG2 cells. In vivo, acute intraperitoneal administration of leptolide (0.1 mg/kg and 1 mg/kg) improved glucose tolerance and insulin sensitivity in lean mice. Likewise, prolonged leptolide treatment (0.1 mg/kg) in diet-induced obese mice improved insulin sensitivity. These effects were paralleled with an ~50% increased of insulin-stimulated phosphorylation of PKB in liver and skeletal muscle and reduced circulating pro-inflammatory cytokines in obese mice. We concluded that leptolide significantly improves insulin sensitivity in vitro and in obese mice, suggesting that leptolide may be another potential treatment for T2DM, This research has been funded by Sociedad Española de Diabetes (Ayudas Investigación Básica 2014), Salud Castilla y León (BIO/VA40/15) and Ministerio de Economía y Competitividad-Spain (SAF2014-58702-C2-1-R) to I.C. and Ministerio de Economía y Competitividad-Spain (SAF2014-58702-C2-2-R) to G.P., We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).

The manufacturing of human mesenchymal stem cells (hMSCs) as cell-based products for clinical use should be performed with appropriate controls that ensure its safety and quality. The use of hMSCs in cell therapy has increased considerably in the past few years. In line with this, the assessment and management of contamination risks by microbial agents that could affect the quality of cells and the safety of patients have to be considered. It is necessary to implant a quality control program (QCP) covering the entire procedure of the ex vivo expansion, from the source of cells, starting materials, and reagents, such as intermediate products, to the final cellular medicine. We defined a QCP to detect microbiological contamination during manufacturing of autologous hMSCs for clinical application. The methods used include sterility test, Gram stain, detection of mycoplasma, endotoxin assay, and microbiological monitoring in process according to the European Pharmacopoeia (Ph. Eur.) and each analytical technique was validated in accordance with three different cell cultures. Results showed no microbiological contamination in any phases of the cultures, meeting all the acceptance criteria for sterility test, detection of mycoplasma and endotoxin, and environmental and staff monitoring. Each analytical technique was validated demonstrating the sensitivity, limit of detection, and robustness of the method. The quality and safety of MSCs must be controlled to ensure their final use in patients. The evaluation of the proposed QCP revealed satisfactory results in order to standardize this procedure for clinical use of cells. © Copyright 2014, Mary Ann Liebert, Inc. 2014., This study was supported by the Fundación Progreso y Salud, Consejería de Salud, Junta de Andalucía (grant PI-0022/2008); Consejería de Innovación Ciencia y Empresa, Junta de Andalucía (grant CTS-6505; INP-2011-1615-900000); FEDER co-funded grants from Instituto de Salud Carlos III (Red TerCel grant RD06/0010/0025; PI10/00964 and PI10/00871); and the Ministry of Health and Consumer Affairs (Advanced Therapies Program grant TRA-120). Support from FSED and FAID allows access to databanks. CIBERDEM is an initiative of the Instituto de Salud Carlos III.

Mesenchymal stromal cells (MSCs) have been established as promising candidate sources of universal donor cells for cell therapy due to their contributions to tissue and organ homeostasis, repair, and support by self-renewal and multidifferentiation, as well as by their anti-inflammatory, antiproliferative, immunomodulatory, trophic, and proangiogenic properties. Various diseases have been treated by MSCs in animal models. Additionally, hundreds of clinical trials related to the potential benefits of MSCs are in progress. However, although all MSCs are considered suitable to exert these functions, dissimilarities have been found among MSCs derived from different tissues. The same levels of efficacy and desired outcomes have not always been achieved in the diverse studies that have been performed thus far. Moreover, autologous MSCs can be affected by the disease status of patients, compromising their use. Therefore, collecting information regarding the characteristics of MSCs obtained from different sources and the influence of the host (patient) medical conditions on MSCs is important for assuring the safety and efficacy of cell-based therapies. This review provides relevant information regarding factors to consider for the clinical application of MSCs., The authors are supported by the Fundacion Progreso y ´ Salud, Consejer´ıa de Salud, Junta de Andaluc´ıa; FEDER cofunded grants from Consejer´ıa de Innovacion Ciencia y ´ Empresa, Junta de Andaluc´ıa (Grants CTS-6505; INP-2011- 1615-900000); FEDER cofunded grants from Instituto de Salud Carlos III (Red TerCel-Grant RD12/0019/0028; PI10/ 00964 and PI14/01015) and the Ministry of Health and Consumer Affairs (Advanced Therapies Program Grant TRA- 120); SUDOE Program-BIOREG (Regenerative Medicine Network-SOE3/P1/E750) and ACTION Cost (European Cooperation in Science and Technology-BM1305). Support from FSED and FAID allowed access to databanks. CIBERDEM is an initiative of the Instituto de Salud Carlos III

Diabetes is a consequence of a decrease on functional β-cell mass. We have recently demonstrated that epoxypukalide (Epoxy) is a natural compound with beneficial effects on primary cultures of rat islets. In this study, we extend our previous investigations to test the hypothesis that Epoxy protects β-cells and improves glucose metabolism in STZ-induced diabetic mice. We used 3-months old male mice that were treated with Epoxy at 200 μg/kg body weight. Glucose intolerance was induced by multiple intraperitoneal low-doses of streptozotocin (STZ) on 5 consecutive days. Glucose homeostasis was evaluated measuring plasma insulin levels and glucose tolerance. Histomorphometry was used to quantify the number of pancreatic β-cells per islet. β-cell proliferation was assessed by BrdU incorporation, and apoptosis by TUNEL staining. Epoxy treatment significantly improved glucose tolerance and plasma insulin levels. These metabolic changes were associated with increased β-cell numbers, as a result of a two-fold increase in β-cell proliferation and a 50% decrease in β-cell death. Our results demonstrate that Epoxy improves whole-body glucose homeostasis by preventing pancreatic β-cell death due to STZ-induced toxicity in STZ-treated mice., This work was supported by grants from: Programa Ramón y Cajal (RYC-2011-08101) Ministerio de Economía y Competitividad (Spain); Sociedad Española de Diabetes Basic Research Grant (2014) to IC.

Stem cells have been successfully used for the treatment of critical limb ischemia (CLI). We conducted a clinical trial to determine the feasibility of using autologous adipose-derived mesenchymal stromal cells (AdMSCs) for the treatment of CLI. Unexpectedly, two diabetic patients developed peripheral microthrombosis. This adverse effect, which contrasts with the reported antithrombotic properties of MSCs, may stem from the diabetic environment that alters the fibrinolytic activity of AdMSCs, thereby increasing the probability of developing thrombosis. Here, we confirm this premise by demonstrating that diabetic AdMSCs cultured in the presence of blood sera expressed and released higher levels of plasminogen activator inhibitor type 1, reduced levels of tissue plasminogen activator, and lower D-dimer formation compared with nondiabetic AdMSCs. Thus, to establish an appropriate cell therapy for diabetic patients, we recommend including new preclinical safety tests, such as the D-dimer and/or the tissue plasminogen activator-to-plasminogen activator inhibitor type 1 ratio tests, to assess fibrinolytic activity of cells before implantation. © 2013 by the American Diabetes Association., The authors are supported by the Fundación Progreso y Salud, Consejería de Salud, Junta de Andalucía (Grant PI- 0022/2008) and Consejería de Innovación Ciencia y Empresa, Junta de Andalucía (Grant CTS-6505, INP-2011-1615-900000). Fondo Europeo de Desarrollo Regional (FEDER) cofunded grants from Instituto de Salud Carlos III (Red TerCel-Grant RD06/0010/0025, PI10/00964, and PI10/00871) and the Ministry of Health and Consumer Affairs (Advanced Therapies Program Grant TRA-120). Support from Fundación de la Sociedad Española de Diabetes (FSED) and Fundación Andaluza de Investigación y Desarrollo (FAID) allow access to databanks.