Hyperglycemia may alter cytokine production and phagocytosis by means other than hyperosmotic stress

miR15a and miR16 in Chilean type 1 diabetes patients: possible association with apoptosis, inflammatory, or autoimmunity markers

AIM

Type 1 diabetes mellitus (T1D) is an autoimmune disease characterized by the progressive destruction of β cells, mediated by the interaction between T cells and several cytokines. The pathogenesis of T1D has established its possible relationship with miRNAs. In this study, we analyze the expression profile of miR-15a and miR-16 in peripheral blood mononuclear cells (PBMCs) and their possible association with apoptosis, inflammation, or autoimmunity markers.

PATIENTS AND METHODOLOGY

38 T1D patients and 41 control subjects were recruited. mRNAs were analyzed by means of qPCR and TaqMan probes. PBMCs were treated with different concentrations of glucose (baseline, 11 and 25 mM) with or without an inflammatory stimulus as TNF-α (10 ng/ml).

RESULTS

A decrease in the levels of the miR-15a expression in basal conditions is observed in T1D patients compared to healthy control subjects (relative units 0.5 vs. 1.8, p < 0.05). This change in miR-15a and miR-16 is not affected by the addition of TNF-α. No association is observed with inflammatory markers (IL-6, TNF-α, vCAM) or apoptosis (bcl2 expression). The relationship with immunological markers shows an interaction effect between miR16 and IA-2 (p < 0.03).

CONCLUSION

TNF-α does not affect the expression profile of miR-15a and miR16 in PBMCs. A weak correlation is observed between miR-16 and with the autoimmunity profile (IA-2 autoantibody).

Expression of miR-155, miR-146a, and miR-326 in T1D patients from Chile: relationship with autoimmunity and inflammatory markers

Objective The aim of this research was to analyze the expression profile of miR-155, miR-146a, and miR-326 in peripheral blood mononuclear cells (PBMC) of 47 patients with type 1 diabetes mellitus (T1D) and 39 control subjects, as well as the possible association with autoimmune or inflammatory markers. Subjects and methods Expression profile of miRs by means of qPCR using TaqMan probes. Autoantibodies and inflammatory markers by ELISA. Statistical analysis using bivariate correlation. Results The analysis of the results shows an increase in the expression of miR-155 in T1D patients in basal conditions compared to the controls (p < 0.001) and a decreased expression level of miR-326 (p < 0.01) and miR-146a (p < 0.05) compared T1D patients to the controls. miR-155 was the only miRs associated with autoinmmunity (ZnT8) and inflammatory status (vCAM). Conclusion Our data show a possible role of miR-155 related to autoimmunity and inflammation in Chilean patients with T1D.

miR15a and miR16 in Chilean type 1 diabetes patients: possible association with apoptosis, inflammatory, or autoimmunity markers

AIM

Type 1 diabetes mellitus (T1D) is an autoimmune disease characterized by the progressive destruction of β cells, mediated by the interaction between T cells and several cytokines. The pathogenesis of T1D has established its possible relationship with miRNAs. In this study, we analyze the expression profile of miR-15a and miR-16 in peripheral blood mononuclear cells (PBMCs) and their possible association with apoptosis, inflammation, or autoimmunity markers.

PATIENTS AND METHODOLOGY

38 T1D patients and 41 control subjects were recruited. mRNAs were analyzed by means of qPCR and TaqMan probes. PBMCs were treated with different concentrations of glucose (baseline, 11 and 25 mM) with or without an inflammatory stimulus as TNF-α (10 ng/ml).

RESULTS

A decrease in the levels of the miR-15a expression in basal conditions is observed in T1D patients compared to healthy control subjects (relative units 0.5 vs. 1.8, p < 0.05). This change in miR-15a and miR-16 is not affected by the addition of TNF-α. No association is observed with inflammatory markers (IL-6, TNF-α, vCAM) or apoptosis (bcl2 expression). The relationship with immunological markers shows an interaction effect between miR16 and IA-2 (p < 0.03).

CONCLUSION

TNF-α does not affect the expression profile of miR-15a and miR16 in PBMCs. A weak correlation is observed between miR-16 and with the autoimmunity profile (IA-2 autoantibody).

Stress hyperglycemia, insulin treatment, and innate immune cells

Hyperglycemia (HG) and insulin resistance are the hallmarks of a profoundly altered metabolism in critical illness resulting from the release of cortisol, catecholamines, and cytokines, as well as glucagon and growth hormone. Recent studies have proposed a fundamental role of the immune system towards the development of insulin resistance in traumatic patients. A comprehensive review of published literatures on the effects of hyperglycemia and insulin on innate immunity in critical illness was conducted. This review explored the interaction between the innate immune system and trauma-induced hypermetabolism, while providing greater insight into unraveling the relationship between innate immune cells and hyperglycemia. Critical illness substantially disturbs glucose metabolism resulting in a state of hyperglycemia. Alterations in glucose and insulin regulation affect the immune function of cellular components comprising the innate immunity system. Innate immune system dysfunction via hyperglycemia is associated with a higher morbidity and mortality in critical illness. Along with others, we hypothesize that reduction in morbidity and mortality observed in patients receiving insulin treatment is partially due to its effect on the attenuation of the immune response. However, there still remains substantial controversy regarding moderate versus intensive insulin treatment. Future studies need to determine the integrated effects of HG and insulin on the regulation of innate immunity in order to provide more effective insulin treatment regimen for these patients.

Good glycemic control is associated with better survival in diabetic patients on peritoneal dialysis: a prospective observational study

BACKGROUND

The effect of glycemic control after starting peritoneal dialysis (PD) on the survival of diabetic PD patients has largely been unexplored, especially in Asian population.

METHODS

We conducted a prospective observational study, in which 140 incident PD patients with diabetes were recruited. Patients were divided into tertiles according to the means of quarterly HbA1C levels measured during the first year after starting PD. We examined the association between HbA1C and all-cause mortality using Cox proportional hazards models.

RESULTS

The mean age was 58.7 years, 59.3% were male, and the mean follow-up duration was 3.5 years (range 0.4-9.5 years). The mean HbA1C levels were 6.3%, 7.1%, and 8.5% in the 1(st), 2(nd), and 3(rd) tertiles, respectively. Compared to the 1(st) tertile, the all-cause mortality rates were higher in the 2(nd) [hazard ratio (HR), 4.16; 95% confidence interval (CI), 0.91-18.94; p = 0.065] and significantly higher in the 3(rd) (HR, 13.16; 95% CI, 2.67-64.92; p = 0.002) tertiles (p for trend = 0.005), after adjusting for confounding factors. Cardiovascular mortality, however, did not differ significantly among the tertiles (p for trend = 0.682). In contrast, non-cardiovascular deaths, most of which were caused by infection, were more frequent in the 2(nd) (HR, 7.67; 95% CI, 0.68-86.37; p = 0.099) and the 3(rd) (HR, 51.24; 95% CI, 3.85-681.35; p = 0.003) tertiles than the 1(st) tertile (p for trend = 0.007).

CONCLUSIONS

Poor glycemic control is associated with high mortality rates in diabetic PD patients, suggesting that better glycemic control may improve the outcomes of these patients.

Blood glucose control in patients with severe sepsis and septic shock

The main pathophysiological feature of sepsis is the uncontrollable activation of both pro- and anti-inflammatory responses arising from the overwhelming production of mediators such as pro- and anti-inflammatory cytokines. Such an uncontrollable inflammatory response would cause many kinds of metabolic derangements. One such metabolic derangement is hyperglycemia. Accordingly, control of hyperglycemia in sepsis is considered to be a very effective therapeutic approach. However, despite the initial enthusiasm, recent studies reported that tight glycemic control with intensive insulin therapy failed to show a beneficial effect on mortality of patients with severe sepsis and septic shock. One of the main reasons for this disappointing result is the incidence of harmful hypoglycemia during intensive insulin therapy. Therefore, avoidance of hypoglycemia during intensive insulin therapy may be a key issue in effective tight glycemic control. It is generally accepted that glycemic control aimed at a blood glucose level of 80-100 mg/dL, as initially proposed by van den Berghe, seems to be too tight and that such a level of tight glycemic control puts septic patients at increased risk of hypoglycemia. Therefore, now many researchers suggest less strict glycemic control with a target blood glucose level of 140-180 mg/dL. Also specific targeting of glycemic control in diabetic patients should be considered. Since there is a significant correlation between success rate of glycemic control and the degree of hypercytokinemia in septic patients, some countermeasures to hypercytokinemia may be an important aspect of successful glycemic control. Thus, in future, use of an artificial pancreas to avoid hypoglycemia during insulin therapy, special consideration of septic diabetic patients, and control of hypercytokinemia should be considered for more effective glycemic control in patients with severe sepsis and septic shock.