Macroeconomic Consequences of Market Manipulation

Regulatory T (Treg) cells are characterized by the expression of CD4, CD25 and the intracellular Foxp3. However, these markers do not indicate whether Treg cells are thymic derived Treg (tTreg) cells or peripherally induced Treg (pTreg) cells. Recently, Helios and Neuropilin-1 (Nrp1) has been reported as potential markers for tTreg cells. Herein, we used flow cytometry to examine the proportion of CD4(+)CD8(-)CD25(+) Treg cells expressing Helios, Nrp1 and Foxp3 in thymus, pancreatic draining lymph nodes (PDLNs) and spleen of CD-1 mice, and thymus of NOD and C57BL/6 mice. The frequency of Helios(+) cells was higher than that of Nrp1(+) cells in CD4(+)CD8(-)CD25(+) and CD4(+)CD8(-)CD25(+)Foxp3(+) Treg cells in thymus. Interestingly, the proportion of IL-10(+), Ebi3(+) and CTLA-4(+) cells was higher in Helios(+) than Nrp1(+) tTreg cells. The anti-apoptotic activity of Helios(+) tTreg cells was higher in thymus compared to Nrp1(+) tTreg cells. Nrp1 seems to be expressed at a later developmental stage compared to Helios and Foxp3. Furthermore, the expression of Nrp1 in CD4(+)CD25(+) T cells of younger mice did not increase after stimulating them in vitro with anti-CD3 and -CD28. Thus, under these conditions, Helios could be considered a more reliable marker for distinguishing tTreg cells from pTreg cells than Nrp1

Altered Expression of Somatostatin Receptors in Pancreatic Islets from NOD Mice Cultured at Different Glucose Concentrations In Vitro and in Islets Transplanted to Diabetic NOD Mice In Vivo

Somatostatin acts via five receptors (sst1–5). We investigated if the changes in pancreatic islet sst expression in diabetic NOD mice compared to normoglycemic mice are a consequence of hyperglycemia or the ongoing immune reaction in the pancreas. Pancreatic islets were isolated from NOD mice precultured for 5 days and further cultured for 3 days at high or low glucose before examined. Islets were also isolated from NOD mice and transplanted to normal or diabetic mice in a number not sufficient to cure hyperglycemia. After three days, the transplants were removed and stained for sst1–5 and islet hormones. Overall, changes in sst islet cell expression were more common in islets cultured in high glucose concentration in vitro as compared to the islet transplantation in vivo to diabetic mice. The beta and PP cells exhibited more frequent changes in sst expression, while the alpha and delta cells were relatively unaffected by the high glucose condition. Our findings suggest that the glucose level may alter sst expressed in islets cells; however, immune mechanisms may counteract such changes in islet sst expression

The Increased Circulating Plasma Levels of Vascular Endothelial Growth Factor in Patients with Type 1 Diabetes Do Not Correlate to Metabolic Control

Aim. To characterize the plasma levels of vascular endothelial growth factor (VEGF) in type 1 diabetes mellitus (T1D) and its relation to both present and historical metabolic control and microvascular complications. Methods. Plasma levels of VEGF and routine clinical parameters were analyzed in 115 patients with long-standing T1D and 45 healthy controls (HC). All patients were under clinical routine diabetes treatment at Uppsala University Hospital. Results. The plasma levels of VEGF were increased by 37% in patients with T1D when compared to HC (18.2 ± 0.8 versus 13.2 ± 1.0 pg/ml, < 0.001). The levels of VEGF correlated to insulin needs and BMI but not to present or historical metabolic control. The levels of VEGF were similar in patients with T1D and microvascular complications (microalbuminuria and retinopathy) when compared with patients without microvascular complications. Historical HbA1c levels were found to be the best predictor for present metabolic control. Conclusion. Circulating plasma levels of VEGF do not correlate to present or historical metabolic control in long-standing T1D and the levels are not affected by the presence of microvascular complications

The Increased Circulating Plasma Levels of Vascular Endothelial Growth Factor in Patients with Type 1 Diabetes Do Not Correlate to Metabolic Control

Aim. To characterize the plasma levels of vascular endothelial growth factor ( VEGF) in type 1 diabetes mellitus (T1D) and its relation to both present and historical metabolic control and microvascular complications. Methods. Plasma levels of VEGF and routine clinical parameters were analyzed in 115 patients with long-standing T1D and 45 healthy controls (HC). All patients were under clinical routine diabetes treatment at Uppsala University Hospital. Results. The plasma levels of VEGF were increased by 37% in patients with T1D when compared to HC (18.2 +/- 0.8 versus 13.2 +/- 1.0 pg/ml, p < 0.001). The levels of VEGF correlated to insulin needs and BMI but not to present or historical metabolic control. The levels of VEGF were similar in patients with T1D and microvascular complications (microalbuminuria and retinopathy) when compared with patients without microvascular complications. Historical HbA1c levels were found to be the best predictor for present metabolic control. Conclusion. Circulating plasma levels of VEGF do not correlate to present or historical metabolic control in long-standing T1D and the levels are not affected by the presence of microvascular complications

Concomitant analysis of Helios and Neuropilin-1 as a marker to detect thymic derived regulatory T cells in naive mice

Regulatory T (Treg) cells are characterized by the expression of CD4, CD25 and the intracellular Foxp3. However, these markers do not indicate whether Treg cells are thymic derived Treg (tTreg) cells or peripherally induced Treg (pTreg) cells. Recently, Helios and Neuropilin-1 (Nrp1) has been reported as potential markers for tTreg cells. Herein, we used flow cytometry to examine the proportion of CD4(+)CD8(-)CD25(+) Treg cells expressing Helios, Nrp1 and Foxp3 in thymus, pancreatic draining lymph nodes (PDLNs) and spleen of CD-1 mice, and thymus of NOD and C57BL/6 mice. The frequency of Helios(+) cells was higher than that of Nrp1(+) cells in CD4(+)CD8(-)CD25(+) and CD4(+)CD8(-)CD25(+)Foxp3(+) Treg cells in thymus. Interestingly, the proportion of IL-10(+), Ebi3(+) and CTLA-4(+) cells was higher in Helios(+) than Nrp1(+) tTreg cells. The anti-apoptotic activity of Helios(+) tTreg cells was higher in thymus compared to Nrp1(+) tTreg cells. Nrp1 seems to be expressed at a later developmental stage compared to Helios and Foxp3. Furthermore, the expression of Nrp1 in CD4(+)CD25(+) T cells of younger mice did not increase after stimulating them in vitro with anti-CD3 and -CD28. Thus, under these conditions, Helios could be considered a more reliable marker for distinguishing tTreg cells from pTreg cells than Nrp1

Macrophage migration inhibitory factor deficiency protects pancreatic islets from palmitic acid-induced apoptosis

As a result of chronic exposure to high levels of free fatty acids, glucose and inflammatory mediators beta-cell apoptosis occurs at the end stage of obesity-associated type 2 diabetes (T2D). One potentially deleterious molecule for beta-cell function associated with T2D and obesity in humans is macrophage migration inhibitory factor (MIF). Therefore, the aim of this study was to explore MIF expression in vivo during development of obesity and insulin resistance in high-fat diet (HFD)-fed C57BL/6 mice and whether MIF inhibition could affect beta-cell apoptosis and dysfunction induced by palmitic acid (PA) in vitro. Indeed, increase in systemic and locally produced MIF correlated well with the weight gain, triglyceride upregulation, glucose intolerance and insulin resistance, which developed in HFD-fed mice. In in vitro settings PA dose-dependently induced MIF secretion before apoptosis development in islets. Further, mif gene deletion, mRNA silencing or protein inhibition rescued beta-cells from PA-induced apoptosis as measured by MTT assay and histone-DNA enzyme linked immuno sorbent assay. Protection from induced apoptosis was mediated by altered activation of caspase pathway and correlated with changes in the level of Bcl-2 family members. Further, MIF inhibition conveyed a significant resistance to PA-induced downregulation of insulin and PDX-1 expression and ATP content. However, beta-cell function was not entirely preserved in the absence of MIF judging by low glucose oxidation and depolarized mitochondria! membrane. In conclusion, the observed considerable preservation of beta-cells from nutrient-induced apoptosis might implicate MIF as a potential therapeutic target in the later stage of obesity-associated T2D. Immunology and Cell Biology (2012) 90, 688-698; doi:10.1038/icb.2011.89; published online 8 November 201

Macrophage migration inhibitory factor (MIF) enhances palmitic acid-and glucose-induced murine beta cell dysfunction and destruction in vitro

Although several reports suggest a potentially deleterious role of macrophage migration inhibitory factor (MIF) in type 2 diabetes (T2D) pathology, it is still unclear how this pro-inflammatory cytokine acts on pancreatic beta cells. The aim of the present study was to evaluate MIF effects on murine beta cells in the in vitro settings mimicking T2D-associated conditions. Results indicate that recombinant MIF further increased apoptosis of pancreatic islets or MIN6 cells upon exposure to palmitic acid or glucose. This was accompanied by upregulation of several pro-apoptotic molecules. Furthermore, MIF potentiated nutrient-induced islet cell dysfunction, as revealed by lower glucose oxidation rate, ATP content, and depolarized mitochondrial membrane. The final outcome was potentiation of mitochondrial apoptotic pathway. The observed upregulation of nutrient-induced islet cell dysfunction and apoptosis by MIF implicates that silencing MIF may be beneficial for maintaining integrity of endocrine pancreas in obesity-associated T2D