Nutrients are required for growth and survival of all cells, but are also crucially involved in cell fate determination of many cell types, including immune cells. There is a growing appreciation... Show moreNutrients are required for growth and survival of all cells, but are also crucially involved in cell fate determination of many cell types, including immune cells. There is a growing appreciation that the metabolic micro-environment also plays a major role in shaping the functional properties of dendritic cells (DCs). Under pathological conditions nutrient availability can range from a very restricted supply, such as seen in a tumor micro-environment, to an overabundance of nutrients found in for example obese adipose tissue. In this review we will discuss what is currently known about the metabolic requirements for DC differentiation and immunogenicity and compare that to how function and fate of DCs under pathological conditions can be affected by alterations in environmental levels of carbohydrates, lipids and amino acids as well as by other metabolic cues, including availability of oxygen, redox homeostasis and lactate levels. Many of these insights have been generated usingin vitromodel systems, which have revealed highly diverse effects of different metabolic cues on DC function. However, they also stress the importance of shifting toward more physiologically relevant experimental settings to be able to fully delineate the role of the metabolic surroundings in its full complexity in shaping the functional properties of DCs in health and disease. Show less
Uitbeijerse, B.S.; Nijhoff, M.F.; Sont, J.K.; Koning, E.J.P. de 2020
In order to assess beta cell secretory capacity after islet transplantation, standardized mixed meal stimulation tests are often used. But these tests are cumbersome and the effect of exogenous... Show moreIn order to assess beta cell secretory capacity after islet transplantation, standardized mixed meal stimulation tests are often used. But these tests are cumbersome and the effect of exogenous insulin on the test results is unclear. The aim of our study was to determine to what extent fasting glycemic indices can estimate stimulated beta cell function in islet transplant recipients with and without basal insulin. In total 100 mixed meal stimulation tests, including 31 with concurrent basal insulin treatment, were performed in 36 islet transplant recipients. In a multivariate model, fasting C-peptide and fasting glucose together estimated peak C-peptide withR(2) = .87 and area under the curve (AUC) C-peptide with aR(2) = .93. There was a larger increase of glucose during tests in which exogenous insulin was used (+7.9 vs +5.3 mmol/L,P < .001) and exogenous insulin use was associated with a slightly lower estimated peak C-peptide (relative change: -15%,P = .02). In islet transplant recipients the combination of fasting C-peptide and glucose can be used to accurately estimate stimulated beta cell function after a mixed meal stimulation test, whether exogenous basal insulin is present or not. These data indicate that graft function can be reliably determined during exogenous insulin treatment and that regular islet graft stimulation tests can be minimized. Show less
Groeneweg, K.E.; Au, Y.W.; Duijs, J.M.G.J.; Florijn, B.W.; Kooten, C. van; Fijter, J.W. de; ... ; Bijkerk, R. 2020
Simultaneous pancreas-kidney transplantation (SPKT) replaces kidney function and restores endogenous insulin secretion in patients with diabetic nephropathy (DN). Here, we aimed to identify... Show moreSimultaneous pancreas-kidney transplantation (SPKT) replaces kidney function and restores endogenous insulin secretion in patients with diabetic nephropathy (DN). Here, we aimed to identify circulating long noncoding RNAs (lncRNAs) that are associated with DN and vascular injury in the context of SPKT. Based on a pilot study and a literature-based selection of vascular injury-related lncRNAs, we assessed 9 candidate lncRNAs in plasma samples of patients with diabetes mellitus with a kidney function >35 mL/min/1.73 m(2) (DM; n = 12), DN (n = 14), SPKT (n = 35), healthy controls (n = 15), and renal transplant recipients (KTx; n = 13). DN patients were also studied longitudinally before and 1, 6, and 12 months after SPKT. Of 9 selected lncRNAs, we found MALAT1, LIPCAR, and LNC-EPHA6 to be higher in DN compared with healthy controls. SPKT caused MALAT1, LIPCAR, and LNC-EPHA6 to normalize to levels of healthy controls, which was confirmed in the longitudinal study. In addition, we observed a strong association between MALAT1, LNC-EPHA6, and LIPCAR and vascular injury marker soluble thrombomodulin and a subset of angiogenic microRNAs (miR-27a, miR-130b, miR-152, and miR-340). We conclude that specific circulating lncRNAs associate with DN-related vascular injury and normalize after SPKT, suggesting that lncRNAs may provide a promising novel monitoring strategy for vascular integrity in the context of SPKT. Show less
We recently reported that loss of hyaluronan (HA) from the endothelial glycocalyx leads to loss of vessel stability in specific microcirculatory vascular beds. Here we hypothesized that such... Show moreWe recently reported that loss of hyaluronan (HA) from the endothelial glycocalyx leads to loss of vessel stability in specific microcirculatory vascular beds. Here we hypothesized that such derangements in the glycocalyx may also impair the adaptive response to vascular ischemia. Endothelial specific conditional hyaluronan synthase 2-KO (Has2-cKO) mice revealed reduced endothelial HA expression and lower hindlimb perfusion at baseline compared to control mice. After a single ligation of the common femoral artery in these mice, we observed dysregulated angiogenesis in the gastrocnemius muscle which did not restore capillary perfusion. Mechanistically, decreased endothelial binding of the pericyte-derived molecule angiopoietin1 (Ang1) could be observed in the Has2-cKO mouse. In vitro angiogenesis assays with an endothelial cell-pericyte coculture confirmed such disturbed Ang1-TIE2 signaling resulting in excessive angiogenesis upon loss of HA. These data could be of relevance to diabetes patients, where we confirm loss of endothelial HA in the microcirculation of muscle tissue, indicating that this may contribute to the known disturbed adaptation to ischemia in these patients. In summary, loss of endothelial HA results in impaired microvascular perfusion and endothelial stability in ischemic gastrocnemius muscle. Endothelial HA is a potential target to improve angiogenic therapy in diabetic patients with critical limb ischemia. Show less
Everaert, I.; He, J.L.; Hanssens, M.; Stautemas, J.; Bakker, K.; Albrecht, T.; ... ; Derave, W. 2020
doi:10.1152/ajprenal.00329.2019. Manipulation of circulating histidine-containing dipeptides (HCD) has been shown to affect the development of diabetes and early-stage diabetic nephropathy (DN).... Show moredoi:10.1152/ajprenal.00329.2019. Manipulation of circulating histidine-containing dipeptides (HCD) has been shown to affect the development of diabetes and early-stage diabetic nephropathy (DN). The aim of the present study was to investigate whether such interventions, which potentially alter levels of circulating HCD, also affect the development of advanced -stage DN. 'Iwo interventions, aerobic exercise training and overexpression of the human carnosinase-1 (hCNI) enzyme, were tested. BTBR ob/ob mice were either subjected to aerobic exercise training (20 wk) or genetically manipulated to overexpress hCNi, and different diabetes- and DNrelated markers were compared with control ob/ob and healthy (wild type) mice. An acute exercise study was performed to elucidate the effect of obesity, acute running, and hCNI overexpression on plasma HCD levels. Chronic aerobic exercise training did not affect the development of diabetes or DN, but hCNI overexpression accelerated hyperlipidemia and aggravated the development of alburninuria, mesangial matrix expansion, and glomerular hypertrophy- of ob/ob mice. In line, plasma, kidney, and muscle 11CD were markedly lower in oh/oh versus wild -type mice, and plasma and kidney HCD in particular were lower in ob/ob hCNI versus ob/ob mice but were unaffected by aerobic exercise. In conclusion, advanced glomerular damage is accelerated in mice overexpressing the hCNI enzyme but not protected by chronic exercise training. Interestingly, we showed, for the first time, that the development of DN is closely linked to renal HCD availability. Further research will have to elucidate whether the stimulation of renal HCD levels can he a therapeutic strategy to reduce the risk for developing DN. Show less
Background Control of blood glucose levels is needed not only to alleviate symptoms of hypoglycaemia and hyperglycaemia, but also to prevent or delay diabetes-related complications. Advice for... Show moreBackground Control of blood glucose levels is needed not only to alleviate symptoms of hypoglycaemia and hyperglycaemia, but also to prevent or delay diabetes-related complications. Advice for glucose control is usually provided to patients by members of the health care team. However, many diabetes apps claim to enhance self-management of blood glucose by providing decision support to patients when an out-of-range blood glucose level is recorded. In this study, we investigated the appropriateness of action prompts provided by diabetes apps for hypoglycaemia and hyperglycaemia against evidence-based guidelines. Methods We used methods previously reported to identify and select diabetes apps, which were downloaded and assessed against the American Diabetes Association (ADA) guidelines. Screenshots of action prompts corresponding to low or high out-of-range blood glucose values were subjected to content analysis. Results Of 371 diabetes self-management apps evaluated, only 217 and 216 apps alerted patients about hypoglycaemia and hyperglycaemia, respectively. Of these, 20.7% (45/217) and 15.3% (33/216) also provided action prompts. We found 5.1% of apps (hypoglycaemia: 11/217; hyperglycaemia: 11/216) provided prompts that were either too general to be helpful or not aligned with ADA guidelines. Overall, only 17.9% (39/217) and 14.8% (32/216) provided appropriate action prompts for hypoglycaemia and hyperglycaemia, respectively. Conclusion Less than one fifth of apps provided evidence-based steps to guide patients through hypoglycaemia and hyperglycaemia. The majority of apps failed to provide just-in-time diabetes self-management education to prevent frequent or severe episodes of hypoglycaemia and hyperglycaemia. Our findings emphasize the need for better design and quality assurance of diabetes apps. Show less
Shift work, defined as work occurring outside typical daytime working hours, is associated with an increased risk of various non-communicable diseases, including diabetes and cardiovascular disease... Show moreShift work, defined as work occurring outside typical daytime working hours, is associated with an increased risk of various non-communicable diseases, including diabetes and cardiovascular disease. Disruption of the internal circadian timing system and concomitant sleep disturbances is thought to play a critical role in the development of these health problems. Indeed, controlled laboratory studies have shown that short-term circadian misalignment and sleep restriction independently impair physiological processes, including insulin sensitivity, energy expenditure, immune function, blood pressure and cardiac modulation by the autonomous nervous system. If allowed to persist, these acute effects may lead to the development of cardiometabolic diseases in the long term. Here, we discuss the evidence for the contributions of circadian disruption and associated sleep disturbances to the risk of metabolic and cardiovascular health problems in shift workers. Improving the understanding of the physiological mechanisms affected by circadian misalignment and sleep disturbance will contribute to the development and implementation of strategies that prevent or mitigate the cardiometabolic impact of shift work. Show less
