Formation of Re-Aggregated Neonatal Porcine Islet Clusters Improves In Vitro Function and Transplantation Outcome.

Neonatal porcine islet-like cell clusters (NPICCs) are a promising source for islet cell transplantation. Excellent islet quality is important to achieve a cure for type 1 diabetes. We investigated formation of cell clusters from dispersed NPICCs on microwell cell culture plates, evaluated the composition of re-aggregated porcine islets (REPIs) and compared in vivo function by transplantation into diabetic NOD-SCID IL2rγ-/- (NSG) mice with native NPICCs. Dissociation of NPICCs into single cells and re-aggregation resulted in the formation of uniform REPI clusters. A higher prevalence of normoglycemia was observed in diabetic NSG mice after transplantation with a limited number (n = 1500) of REPIs (85.7%) versus NPICCs (n = 1500) (33.3%) (p < 0.05). Transplanted REPIs and NPICCs displayed a similar architecture of endocrine and endothelial cells. Intraperitoneal glucose tolerance tests revealed an improved beta cell function after transplantation of 1500 REPIs (AUC glucose 0-120 min 6260 ± 305.3) as compared to transplantation of 3000 native NPICCs (AUC glucose 0-120 min 8073 ± 536.2) (p < 0.01). Re-aggregation of single cells from dissociated NPICCs generates cell clusters with excellent functionality and improved in vivo function as compared to native NPICCs.

Depressive symptoms, impaired glucose metabolism, high visceral fat, and high systolic blood pressure in a subgroup of women with recent gestational diabetes.

Women with gestational diabetes (GDM) are a high risk group for early type 2 diabetes (T2D). Depression is a risk factor for T2D in the general population. We investigated in women after a recent pregnancy with GDM and without a clinical diagnosis of depression, whether mild to moderate depressive symptoms associate with pathologic glucose metabolism. In a cross-sectional analysis, we examined 173 women, 9 ± 3 months after delivery with several psychopathological assessments, 5-point oral glucose tolerance test with insulin, anthropometrics, and laboratory chemistry. In a subgroup of 101 women, abdominal visceral fat was quantified by magnetic resonance imaging (MRI). A total of 22 women (13%) showed mild to moderate depressive symptoms, and the proportion of women with pathologic glucose metabolism (impaired fasting glucose, impaired glucose tolerance, or T2D) was higher in this group than in the women without depressive symptoms (59.1% vs. 33.1%, p = 0.018). Women with depressive symptoms also had higher body mass index (BMI), systolic blood pressure, plasma leptin, plasma resistin, and abdominal visceral fat volume. Pathologic glucose metabolism (OR = 2.594, 95% CI: 1.021-6.592), systolic blood pressure (OR = 1.076, 95% CI: 1.027-1.128), and abdominal visceral fat volume (OR = 2.491, 95% CI: 1.142-5.433) remained, even after adjustment for BMI, associated with the presence of depressive symptoms. Taken together, we found depressive symptoms at a level not generally diagnosed in clinical practice in a subgroup of women with recent GDM. This subgroup also showed an unfavorable metabolic profile. Mild to moderate depressive symptoms may therefore help to identify this special subgroup.

Serum and plasma amino acids as markers of prediabetes, insulin resistance, and incident diabetes.

Presently, routine screening misses many cases of prediabetes and early type 2 diabetes (T2D). Therefore, better biomarkers are needed for a simple and early detection of abnormalities of glucose metabolism and prediction of future T2D. Possible candidates for this include plasma or serum amino acids because glucose and amino acid metabolism are closely connected. This review presents the available evidence of this connectivity and discusses its clinical implications. First, we examine the underlying physiological, pre-analytical, and analytical issues. Then, we summarize results of human studies that evaluate amino acid levels as markers for insulin resistance, prediabetes, and future incident T2D. Finally, we illustrate the interconnection of amino acid levels and metabolic syndrome with our own data from a deeply phenotyped human cohort. We also discuss how amino acids may contribute to the pathophysiology of T2D. We conclude that elevated branched-chain amino acids and reduced glycine are currently the most robust and consistent amino acid markers for prediabetes, insulin resistance, and future T2D. Yet, we are cautious regarding the clinical potential even of these parameters because their discriminatory power is insufficient and their levels depend not only on glycemia, but also on other components of the metabolic syndrome. The identification of more precise intermediates of amino acid metabolism or combinations with other biomarkers will, therefore, be necessary to obtain in order to develop laboratory tests that can improve T2D screening.

Insulin secretory defect in familial partial lipodystrophy Type 2 and successful long-term treatment with a glucagon-like peptide 1 receptor agonist.

BACKGROUND: Familial partial lipodystrophies are rare monogenic disorders that are often associated with diabetes. In such cases, it can be difficult to achieve glycaemic control. CASE REPORT: We report a 34-year old woman with familial partial lipodystrophy type 2 (Dunnigan) and diabetes; her hyperglycaemia persisted despite metformin treatment. A combined intravenous glucose tolerance-euglycaemic clamp test showed severe insulin resistance, as expected, but also showed strongly diminished first-phase insulin secretion. After the latter finding, we added the glucagon-like peptide-1 receptor agonist liraglutide to the patient's treatment regimen, which rapidly normalized plasma glucose levels. HbA1c values <42 mmol/mol (6.0%) have now been maintained for over 4 years. CONCLUSION: This case suggests that a glucagon-like peptide-1 receptor agonist may be a useful component of glucose-lowering therapy in individuals with familial partial lipodystrophy and diabetes mellitus.

LEA29Y expression in transgenic neonatal porcine islet-like cluster promotes long-lasting xenograft survival in humanized mice without immunosuppressive therapy.

Genetically engineered pigs are a promising source for islet cell transplantation in type 1 diabetes, but the strong human anti-pig immune response prevents its successful clinical application. Here we studied the efficacy of neonatal porcine islet-like cell clusters (NPICCs) overexpressing LEA29Y, a high-affinity variant of the T cell co-stimulation inhibitor CTLA-4Ig, to engraft and restore normoglycemia after transplantation into streptozotocin-diabetic NOD-SCID IL2rγ-/- (NSG) mice stably reconstituted with a human immune system. Transplantation of INSLEA29Y expressing NPICCs resulted in development of normal glucose tolerance (70.4%) and long-term maintenance of normoglycemia without administration of immunosuppressive drugs. All animals transplanted with wild-type NPICCs remained diabetic. Immunohistological examinations revealed a strong peri- and intragraft infiltration of wild-type NPICCs with human CD45+ immune cells consisting of predominantly CD4+ and CD8+ lymphocytes and some CD68+ macrophages and FoxP3+ regulatory T cells. Significantly less infiltrating lymphocytes and only few macrophages were observed in animals transplanted with INSLEA29Y transgenic NPICCs. This is the first study providing evidence that beta cell-specific LEA29Y expression is effective for NPICC engraftment in the presence of a humanized immune system and it has a long-lasting protective effect on inhibition of human anti-pig xenoimmunity. Our findings may have important implications for the development of a low-toxic protocol for porcine islet transplantation in patients with type 1 diabetes.

Physical fitness and plasma leptin in women with recent gestational diabetes.

AIMS/HYPOTHESIS: Low physical fitness (PF) is a risk factor for type 2 diabetes mellitus (T2D). Women with a history of gestational diabetes (GDM) are at risk for T2D at a young age, but the role of PF in this population is not clear. PF has also been found to correlate inversely with plasma leptin in previous studies. Here, we examine whether women who had GDM have lower PF than women after a normoglycemic pregnancy and, second, whether PF is associated with plasma leptin, independently of body fat mass. METHODS: Cross-sectional analysis of 236 participants in the PPSDiab Study (cohort study of women 3-16 months after delivery, 152 after gestational diabetes (pGDM), 84 after normoglycemic pregnancy (control subjects); consecutively recruited 2011-16); medical history, physical examination with bioelectrical impedance analysis (BIA), whole body magnetic resonance imaging (MRI) (n = 154), 5-point oral glucose tolerance test, cardiopulmonary exercise testing, clinical chemistry including fasting plasma leptin; statistical analysis with Mann-Whitney U and t -test, Spearman correlation coefficient, multiple linear regression. RESULTS: Women pGDM had lower maximally achieved oxygen uptake (VO2peak/kg: 25.7(21.3-29.9) vs. 30.0(26.6-34.1)ml/min/kg; total VO2peak: 1733(1552-2005) vs. 1970(1767-2238)ml/min; p<0.0001 for both), and maximum workload (122.5(105.5-136.5) vs. 141.0(128.5-159.5)W; p<0.0001). Fasting plasma leptin correlated inversely with PF (VO2peak/kg ρ = -0.72 p<0.0001; VO2peak ρ = -0.16 p = 0.015; max. load ρ = -0.35 p<0.0001). These associations remained significant with adjustment for body mass index, or for body fat mass (BIA and MRI). CONCLUSIONS/INTERPRETATION: Women with a recent history of GDM were less fit than control subjects. Low PF may therefore contribute to the risk for T2D after GDM. This should be tested in intervention studies. Low PF also associated with increased leptin levels-independently of body fat. PF may therefore influence leptin levels and signaling. This hypothesis requires further investigation.

Poor sleep quality is associated with impaired glucose tolerance in women after gestational diabetes.

We analyzed the association of sleep quality and glucose metabolism in women after gestational diabetes (pGDM) and in women after normoglycemic pregnancy (controls). Data during pregnancy and a visit within the first 15 months after delivery were collected from 61 pGDM and 30 controls in a prospective cohort study. This included a medical history, physical examination, questionnaires (Pittsburgh Sleep Quality Index (PSQI), and Perceived Stress Scale (PSS)), and 5-point oral glucose tolerance test with insulin measurements to determine indices of insulin sensitivity and insulin secretion. We used Spearman correlation coefficients and multivariate regression models for analysis.9.3 ± 3.2 months after delivery, pGDM had significantly higher fasting and 2 h glucose levels and lower insulin sensitivity than controls. There was no significant difference in age, BMI and sleep quality as assessed with the PSQI between the two groups. The PSQI score correlated with the ogtt-2 h plasma glucose in pGDM (δ = 0.41; p = 0.0012), but not in controls. This association was confirmed with a multivariate linear regression model with adjustment for age, BMI and months post-delivery. Perceived stress was an independent risk factor (OR 1.12; 95% CI 1.02-1.23) for impaired sleep. Our findings suggest that post-delivery sleep quality significantly influences glucose tolerance in women after GDM and that impaired sleep is associated with increased stress perception. Measures to improve of sleep quality and reduce perceived stress should therefore be tested as additional strategies to prevent progression to type 2 diabetes after GDM.

[Current concepts in diagnostics and therapy of diabetes mellitus]. / Aktuelle Konzepte in der Diagnostik und Therapie des Diabetes mellitus.

In Germany approximately 7.2% of the population currently suffer from diabetes mellitus. A further increase in the prevalence is expected in the coming years. Many therapy options, sometimes even without a risk of hypoglycemia, are now available. The foundations of a sufficient therapy of type 2 diabetes are, however, still lifestyle measures, such as weight reduction, optimized nutrition and increased physical activity. Optimization of cardiac and cerebrovascular risk factors is also an essential component of management of diabetes in order to reduce or even avoid secondary complications.

Xenotransplantation of porcine islet cells as a potential option for the treatment of type 1 diabetes in the future.

Solid organ and cell transplantation, including pancreatic islets constitute the treatment of choice for chronic terminal diseases. However, the clinical use of allogeneic transplantation is limited by the growing shortage of human organs. This has prompted us to initiate a unique multi-center and multi-team effort to promote translational research in xenotransplantation to bring xenotransplantation to the clinical setting. Supported by the German Research Foundation, an interdisciplinary group of surgeons, internal medicine doctors, diabetologists, material sciences experts, immunologists, cell biologists, virologists, veterinarians, and geneticists have established a collaborative research center (CRC) focusing on the biology of xenogeneic cell, tissue, and organ transplantation. A major strength of this consortium is the inclusion of members of the regulatory bodies, including the Paul-Ehrlich Institute (PEI), infection specialists from the Robert Koch Institute and PEI, veterinarians from the German Primate Center, and representatives of influential ethical and religious institutions. A major goal of this consortium is to promote islet xenotransplantation, based on the extensive expertise and experience of the existing clinical islet transplantation program. Besides comprehensive approaches to understand and prevent inflammation-mediated islet xenotransplant dysfunction [immediate blood-mediated inflammatory reaction (IBMIR)], we also take advantage of the availability of and experience with islet macroencapsulation, with the goal to improve graft survival and function. This consortium harbors a unique group of scientists with complementary expertise under a cohesive program aiming at developing new therapeutic approaches for islet replacement and solid organ xenotransplantation.

Plasma MR-proANP levels are associated with carotid intima-media thickness in the general community: the KORA F4 study.

OBJECTIVE: Subjects with metabolic syndrome (MetS) and individuals with type 2 diabetes are at high risk for vascular complications. Hormones acting on vascular endothelium may be involved in the atherogenic process associated with metabolic disorders. The objective of this study was to determine the correlation of pro-atrial natriuretic hormone (proANP) with the presence of subclinical atherosclerosis. METHODS: In 1272 subjects participating in the KORA F4 study, we determined plasma levels of mid-regional proANP (MR-proANP) and the intima-media thickness (IMT) of the carotid artery. We used logistic regression models to investigate the relation of MR-proANP with components of MetS and IMT. RESULTS: In multiple adjusted regression models, MR-proANP levels were inversely associated with MetS (OR = 0.66, 95% CI 0.47-0.93), central obesity (OR = 0.67, 95% CI 0.46-0.96), raised triglyceride levels (OR = 0.53, 95% CI 0.37-0.77), prediabetes (OR = 0.62, 95%, CI 0.44-0.87) and type 2 diabetes (OR = 0.55, 95% CI 0.35-0.88) when comparing the top quartile vs. the lower three quartiles. Furthermore, there was an inverse relationship between MR-proANP and IMT. After adjustment for traditional cardiovascular risk markers, individuals with high MR-proANP plasma levels in the top quartile (Q4) had significantly lower IMT values (Q4 vs. Q1-Q3: ß -0.0178, 95% CI -0.0344; -0.0013). CONCLUSIONS: In this population-based study, high plasma concentrations of MR-proANP were significantly associated with a lower incidence of MetS components and lower measures of early atherosclerosis. The data suggest a link between MR-proANP levels and the development of vascular complications.

Antimicrobial effects of murine mesenchymal stromal cells directed against Toxoplasma gondii and Neospora caninum: role of immunity-related GTPases (IRGs) and guanylate-binding proteins (GBPs).

Mesenchymal stromal cells (MSCs) have a multilineage differentiation potential and provide immunosuppressive and antimicrobial functions. Murine as well as human MSCs restrict the proliferation of T cells. However, species-specific differences in the underlying molecular mechanisms have been described. Here, we analyzed the antiparasitic effector mechanisms active in murine MSCs. Murine MSCs, in contrast to human MSCs, could not restrict the growth of a highly virulent strain of Toxoplasma gondii (BK) after stimulation with IFN-γ. However, the growth of a type II strain of T. gondii (ME49) was strongly inhibited by IFN-γ-activated murine MSCs. Immunity-related GTPases (IRGs) as well as guanylate-binding proteins (GBPs) contributed to this antiparasitic effect. Further analysis showed that IFN-γ-activated mMSCs also inhibit the growth of Neospora caninum, a parasite belonging to the apicomplexan group as well. Detailed studies with murine IFN-γ-activated MSC indicated an involvement in IRGs like Irga6, Irgb6 and Irgd in the inhibition of N. caninum. Additional data showed that, furthermore, GBPs like mGBP1 and mGBP2 could have played a role in the anti-N. caninum effect of murine MSCs. These data underline that MSCs, in addition to their regenerative and immunosuppressive activity, function as antiparasitic effector cells as well. However, IRGs are not present in the human genome, indicating a species-specific difference in anti-T. gondii and anti-N. caninum effect between human and murine MSCs.

[Update on type 1 diabetes]. / Update Typ-1-Diabetes.

Type 1a diabetes develops from a chronic autoimmune process leading to absolute insulin deficiency and proneness to ketosis. Prospective studies have clearly shown that intensive insulin therapy (ICT) results in improved quality of life and reduced development of diabetes-associated microvascular and macrovascular complications. The gold standard of therapy in type 1 diabetes is insulin injection with a basal bolus insulin regimen, in which patient daily routine and wishes are considered. The treatment goals should be determined on an individualized basis together with the patient. An HbA(1c) value < 7.0% is considered to be well controlled while values ≤ 6.5% indicate an excellent blood glucose control, as long as there are no episodes of severe hypoglycemia. As many adult patients with type 1 diabetes develop additional cardiovascular risk factors dyslipidemia and hypertension should also be considered and treated according to current treatment guidelines. A multimodal treatment may be the best way to preserve quality of life in patients with type 1 diabetes.

Suppression of the nuclear factor Eny2 increases insulin secretion in poorly functioning INS-1E insulinoma cells.

Eny2, the mammalian ortholog of yeast Sus1 and drosophila E(y)2, is a nuclear factor that participates in several steps of gene transcription and in mRNA export. We had previously found that Eny2 expression changes in mouse pancreatic islets during the metabolic adaptation to pregnancy. We therefore hypothesized that the protein contributes to the regulation of islet endocrine cell function and tested this hypothesis in rat INS-1E insulinoma cells. Overexpression of Eny2 had no effect but siRNA-mediated knockdown of Eny2 resulted in markedly increased glucose and exendin-4-induced insulin secretion from otherwise poorly glucose-responsive INS-1E cells. Insulin content, cellular viability, and the expression levels of several key components of glucose sensing remained unchanged; however glucose-dependent cellular metabolism was higher after Eny2 knockdown. Suppression of Eny2 enhanced the intracellular incretin signal downstream of cAMP. The use of specific cAMP analogues and pathway inhibitors primarily implicated the PKA and to a lesser extent the EPAC pathway. In summary, we identified a potential link between the nuclear protein Eny2 and insulin secretion. Suppression of Eny2 resulted in increased glucose and incretin-induced insulin release from a poorly glucose-responsive INS-1E subline. Whether these findings extend to other experimental conditions or to in vivo physiology needs to be determined in further studies.

Screening for primary aldosteronism in hypertensive subjects: results from two German epidemiological studies.

OBJECTIVE: The prevalence of primary aldosteronism in unselected hypertensive patients is currently unknown. We investigated the frequency of positive screening results for primary aldosteronism based on the aldosterone-to-renin ratio (ARR) in hypertensive subjects aged 30-79 years from two German epidemiological studies. We further examined the frequency of positive screening results in subjects with resistant hypertension or stage III hypertension and assessed possible disparities between untreated and treated hypertensive subjects. METHODS: Data were obtained from the first follow-ups of the population-based study of health in Pomerania (SHIP; n=1392) and the cooperative health research in the region of Augsburg (KORA; n=1052). Study-specific reference ranges for plasma aldosterone concentration (PAC), plasma renin concentration (PRC) and the ARR were applied. Confirmation tests for primary aldosteronism were not performed in these epidemiological studies.Three definitions for a positive screening for primary aldosteronism were applied: A) increased ARR; B) increased ARR and decreased PRC; and C) increased ARR and increased PAC and decreased PRC. RESULTS: The frequency of positive screening results was 7.0, 3.8 and 0.2% according to definitions A-C respectively. In the subgroups of subjects with resistant hypertension (11.9, 5.5 and 0.9%) or stage III hypertension (18.3, 14.0 and 1.1%), these frequencies were markedly higher than those in the general hypertensive population. There was no difference in the frequency of positive screening results between the treated and untreated hypertensive subjects. CONCLUSIONS: A maximum of 7.0% of the hypertensive population in Germany shows a positive screening result for primary aldosteronism. Thus, primary aldosteronism may be less frequent than previously expected based on data from referred hypertensive patients.

Increased serum concentrations of adhesion molecules but not of chemokines in patients with Type 2 diabetes compared with patients with Type 1 diabetes and latent autoimmune diabetes in adult age: action LADA 5.

AIMS: Systemic concentrations of adhesion molecules and chemokines are associated with increased risk of cardiovascular complications. We compared these factors between patients with Type 2 diabetes vs. Type 1 diabetes or latent autoimmune diabetes in adults. METHODS: Serum concentrations of adhesion molecules sE-selectin, sICAM-1 and sVCAM-1, and chemokines CCL2, CCL3 and CCL4 were measured in 61 patients with latent autoimmune diabetes in adults, 90 with Type 1 diabetes, 465 with Type 2 diabetes and in 41 control subjects, using multiple regression models to adjust for possible confounders. RESULTS: Patients with Type 2 diabetes exhibited greater concentrations of adhesion molecules (P < 0.02) than those with Type 1 diabetes, latent autoimmune diabetes in adults and control subjects. These differences persisted upon adjustments for age, sex, BMI, blood pressure and diabetes duration (P < 0.04). Higher BMI positively correlated with concentrations of adhesion molecules in all subjects (P < 0.0001). Concentrations of sE-selectin positively related to diastolic (ß = 0.31) and systolic (ß = 0.28) blood pressure in the adjusted model (P < 0.04). Concentrations of the chemokines, CCL2 and CCL4, did not differ between groups, while CCL3 was higher in patients with latent autoimmune diabetes in adults and Type 1 diabetes than in those with Type 2 diabetes and control subjects (P < 0.05). CONCLUSIONS: Systemic concentrations of adhesion molecules, but not chemokines, relate to cardiovascular risk factors, but remain higher after adjustments in Type 2 diabetes, suggesting a diabetes-type specific effect without difference between latent autoimmune diabetes in adults and Type 1 diabetes, despite their dissimilar phenotype.

[Gestational diabetes]. / Gestationsdiabetes.

Gestational diabetes is one of the most common complications during pregnancy. Its incidence has increased in recent decades. This is partly due to improved screening strategies and more stringent diagnostic criteria. Using the updated diagnostic thresholds, it is expected that 5-10% at least of all pregnant women will be diagnosed with diabetes mellitus. The rationale for the novel blood glucose criteria are data from prospective studies reporting an increase of fetal and maternal complications even when the blood glucose is only slightly increased. For the first time, solid evidence now exists for the diagnosis and treatment of gestational diabetes.

Kinetics of insulin secretion and glucose intolerance in adult patients with cystic fibrosis.

Disturbance of glucose metabolism and diabetes is an increasing complication in adult patients with cystic fibrosis (CF). The aim of the present study was to evaluate the impact of insulin and glucagon-like peptide-1 (GLP-1) secretion on early disturbance of glucose metabolism and clinical status in an unselected cohort of CF patients. 34 adult CF patients and 10 matched healthy subjects underwent an oral glucose tolerance test. Blood samples were taken to measure indices for insulin secretion and insulin sensitivity. Metabolic parameters were correlated with anthropometric and clinical data. In CF patients, there was a decrease in first phase insulin secretion (FPIR) with progressive delay of insulin peak, which was correlated with worsening glucose tolerance (Stumvoll index: normal glucose tolerance: 450±291; impaired fasting glucose: 252±203; impaired glucose tolerance: 309±254; CF related diabetes: 18±41; controls: 950±388) and high early post-challenge glucose peak (p<0.01 vs. controls). However, total insulin secretory capacity was not decreased in CF patients resulting to low glucose levels in the late phase (120-180 min). We found neither a difference in basal or maximal GLP-1 levels nor in insulin resistance between study groups. Maximum glucose levels correlated with impaired FEV1 (rs=-0.5, p=0.002). Our data demonstrate that alteration of FPIR, but not insulinopenia, insulin resistance, or disturbed GLP-1 secretion is present in the prediabetic state in CF patients. Correlation between high glucose levels and worse clinical status suggest that diabetes treatment should be initiated more early in the state of glucose intolerance.

Reduced proliferation and a high apoptotic frequency of pancreatic beta cells contribute to genetically-determined diabetes susceptibility of db/db BKS mice.

Leptin receptor-deficient db/db mice are a commonly used research model and it is known that the genetic background, on which the mutation is bred, modulates the phenotype. While diabetes-resistant strains sustain near normal glycemia and hyperinsulinemia, susceptible backgrounds develop overt hyperglycemia and islet involution. We hypothesized that genetically-determined differences in the proliferative capacity and the apoptotic frequency of pancreatic beta cells contribute to this phenotypic disparity. We studied C57BLKS/J (BKS; diabetes-susceptible) and C57BL/6 (B6; diabetes-resistant) db/db mice and heterozygous controls from 5 to 12 weeks of age. Body weight, fasting blood glucose, plasma insulin, HOMA-IR, alpha cell mass, beta cell mass, proliferation and apoptosis were measured. Comparable insulin resistance developed in the 2 db/db strains, which was well compensated for on both genetic backgrounds until 7 weeks of age. As expected, the BKS mice became hyperglycemic at 9 weeks. Beta cell proliferation was initially increased in both db/db strains but decreased rapidly in the BKS mice with advancing age. The rate of beta cell apoptosis was already higher in prediabetic BKS mice than in their B6 counterparts. Beta cell mass increased continuously in the B6 strain until 12 weeks of age, but declined from 7 weeks onwards in BKS. An age-dependent decline of beta cell proliferation and an increased rate of beta cell apoptosis already in the prediabetic state probably contribute to the diabetes susceptibility of db/db BKS mice. These factors could also play a role in the genetic predisposition for type 2 diabetes in humans.

Pro- and anti-inflammatory cytokines in latent autoimmune diabetes in adults, type 1 and type 2 diabetes patients: Action LADA 4.

AIMS/HYPOTHESIS: Systemic pro- and anti-inflammatory cytokines are associated with both type 1 and type 2 diabetes, while their role in latent autoimmune diabetes in adults (LADA) is unclear. Therefore, we compared cytokine concentrations in patients with LADA, type 1 or type 2 diabetes and healthy individuals to test the hypothesis that differences of cytokine concentrations between all groups are attributable to diabetes type and BMI. METHODS: The pro-inflammatory cytokines IL-6 and TNF-α, and the anti-inflammatory cytokines IL-1 receptor antagonist (IL-1RA) and IL-10 were measured in 90 participants with type 1 diabetes, 61 with LADA, 465 with type 2 diabetes and 41 control participants using multiple regression models adjusted for BMI, sex, age, blood pressure and diabetes duration. RESULTS: Patients with type 2 diabetes had higher concentrations of systemic IL-1RA, IL-6 and TNF-α cytokines than patients with either LADA or type 1 diabetes (p < 0.0001 for all differences). Cytokine concentrations in controls were lower than those in all diabetes types (p < 0.04). Increased BMI was positively associated with higher systemic cytokine concentrations in all diabetes types (p < 0.0001). Despite the association of cytokines with anthropometric data, differences between diabetes forms persisted also after adjusting analysis for the confounders BMI, age, sex, disease duration and blood pressure (p < 0.04). CONCLUSIONS/INTERPRETATION: Although body mass associates positively with pro- and anti-inflammatory cytokine levels, patients with type 2 diabetes have higher cytokine levels independent of the prevailing BMI. LADA and type 1 diabetes could not be distinguished by systemic cytokines.

Human but not murine multipotent mesenchymal stromal cells exhibit broad-spectrum antimicrobial effector function mediated by indoleamine 2,3-dioxygenase.

Human multipotent mesenchymal stromal cells (MSCs) exhibit multilineage differentiation potential, support hematopoiesis, and inhibit proliferation and effector function of various immune cells. On the basis of these properties, MSC are currently under clinical investigation in a range of therapeutic applications including tissue repair and immune-mediated disorders such as graft-versus-host-disease refractory to pharmacological immunosuppression. Although initial clinical results appear promising, there are significant concerns that application of MSC might inadvertently suppress antimicrobial immunity with an increased risk of infection. We demonstrate here that on stimulation with inflammatory cytokines human MSC exhibit broad-spectrum antimicrobial effector function directed against a range of clinically relevant bacteria, protozoal parasites and viruses. Moreover, we identify the tryptophan catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) as the underlying molecular mechanism. We furthermore delineate significant differences between human and murine MSC in that murine MSC fail to express IDO and inhibit bacterial growth. Conversely, only murine but not human MSC express inducible nitric oxide synthase on cytokine stimulation thus challenging the validity of murine in vivo models for the preclinical evaluation of human MSC. Collectively, our data identify human MSC as a cellular immunosuppressant that concurrently exhibits potent antimicrobial effector function thus encouraging their further evaluation in clinical trials.