Impairment of immune systems in diabetes

Update on the ZNT8 epitope and its role in the pathogenesis of type 1 diabetes

Type 1 diabetes (T1D) is an organ-specific chronic autoimmune disease mediated by autoreactive T cells. ZnT8 is a pancreatic islet-specific zinc transporter that is mainly located in β cells. It not only participates in the synthesis, storage and secretion of insulin but also maintains the structural integrity of insulin. ZnT8 is the main autoantigen recognized by autoreactive CD8+ T cells in children and adults with T1D. This article summarizes the latest research results on the T lymphocyte epitope and B lymphocyte epitope of ZnT8 in the current literature. The structure and expression of ZnT8, the role of ZnT8 in insulin synthesis and its role in autoimmunity are reviewed. ZnT8 is the primary autoantigen of T1D and is specifically expressed in pancreatic islets. Thus, it is one of biomarkers for the diagnosis of T1D. It has broad prospects for further research on immunomodulators for the treatment of T1D.

Serum IL-1ra Is Associated with but Has No Genetic Link to Type 1 Diabetes

Interleukin-1 antagonism is a proposed biomarker and potential therapy for the delay and/or treatment of type 1 diabetes (T1D). We evaluated the role of circulating interleukin-1 receptor antagonist (IL-1ra) in a prospectively monitored cohort of T1D patients. In order to determine a mechanistic association between IL-1ra and T1D, we performed co-localization analyses between serum IL-1ra protein quantitative trait loci and T1D genome-wide analysis studies. Adjusting for human leukocyte antigen (HLA) genotypes, first degree relative status, gender, and age, serum levels of IL-1ra were lower in subjects who progressed to T1D compared to the controls (p = 0.023). Our results suggest that females have higher levels of IL-1ra compared to males (p = 0.005). The 2q14.1 region associated with serum IL-1ra levels is not associated with a risk of developing T1D. Our data suggest that IL-1 antagonism by IL-1ra is not an effective therapy in T1D, but IL-1ra may be a biomarker for progression to T1D.

Impaired Innate Immunity in Pediatric Patients Type 1 Diabetes-Focus on Toll-like Receptors Expression

Type 1 diabetes (DM1) is classified as an autoimmune disease. An uncontrolled response of B and T lymphocytes to the body's own tissues develops in the absence of immune tolerance. The main aim of the study was to evaluate the effect of the duration of type 1 diabetes in children on the expression of TLR receptors and the relationship with the parameters of glycemic control in patients. As a result, we showed significant differences in the level of TLR2, TLR4 and TLR9 expression in patients with DM1 in the early stage of the disease and treated chronically compared to the healthy group. Additionally, in this study, we found that the numbers of CD19+ B cells, CD3+ CD4+, CD3+ CD8+ T cells and NK cells are different for newly diagnosed DM1 individuals, patients receiving chronic treatment and for healthy controls, indicating an important role of these cells in killing pancreatic beta cells. Moreover, higher levels of IL-10 in patients with newly diagnosed DM1 have also been found, confirming the reports found in the literature.

Hsa_circ_0060450 Negatively Regulates Type I Interferon-Induced Inflammation by Serving as miR-199a-5p Sponge in Type 1 Diabetes Mellitus

Circular RNAs (circRNAs) constitute a class of covalently circular non-coding RNA molecules formed by 5′ and 3′ end back-splicing. The rapid development of bioinformatics and large-scale sequencing has led to the identification of functional circRNAs. Despite an overall upward trend, studies focusing on the roles of circRNAs in immune diseases remain relatively scarce. In the present study, we obtained a differential circRNA expression profile based on microarray analysis of peripheral blood mononuclear cells (PBMCs) in children with type 1 diabetes mellitus (T1DM). We characterized one differentially expressed circRNA back-spliced from the MYB Proto-Oncogene Like 2 (MYBL2) gene in patients with T1DM, termed as hsa_circ_0060450. Subsequent assays revealed that hsa_circ_0060450 can serve as the sponge of miR-199a-5p, release its target gene, Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), encoded by the tyrosine-protein phosphatase non-receptor type 11 gene (PTPN11), and further suppress the JAK-STAT signaling pathway triggered by type I interferon (IFN-I) to inhibit macrophage-mediated inflammation, which indicates the important roles of circRNAs in T1DM and represents a promising therapeutic molecule in the treatment of T1DM.

Interleukin-6 and Interleukin-15 as Possible Biomarkers of the Risk of Autoimmune Diabetes Development

Aim

The aim of our study was to assay circulating interleukin-15 (IL-15) and interleukin-6 (IL-6) levels and insulin resistance measured by two different methods in newly diagnosed autoimmune diabetes (AD) patients, their I° relatives, and healthy controls.

Material and Methods

The group studied consisted of 54 patients with AD (28 with Latent Autoimmune Diabetes in Adults (LADA) and 26 with type 1 diabetes (T1D)), 70 first-degree relatives, and 60 controls. IL-6, IL-15, and anti-islet antibodies concentrations were measured by ELISA method. Homeostatic model assessment-insulin resistance (HOMAIR) and estimated glucose disposal rate (eGDR) were calculated.

Results

The patients with AD had significantly higher IL-15, IL-6, and HOMAIR and lower eGDR than the controls (p < 0.001, respectively) and first-degree relatives (p < 0.001, respectively). Significantly higher IL-15 and IL-6 were shown in the relatives with positive Ab as compared to the relatives without antibodies (p < 0.001, respectively) and the controls (p < 0.001, respectively). IL-15 negatively correlated with eGDR (r = −0.436, p = 0.021) in LADA and positively with HOMAIR in LADA and T1D (r = 0.507, p < 0.001; r = 0.4209, p < 0.001).

Conclusions

Significantly higher IL-15 and IL-6 concentrations, HOMAIR, and markedly lower eGDR in newly diagnosed AD patients and first-degree relatives with positive anti-islet antibodies might suggest the role of these pro-inflammatory cytokines and insulin resistance in the pathogenesis of autoimmune diabetes. IL-15 and IL-6 might be used as biomarkers of the risk of autoimmune diabetes development, in particular IL-15 for LADA. Both methods of IR measurement appear equally useful for calculating insulin resistance in autoimmune diabetes.

Co-occurrence of opisthorchiasis and diabetes exacerbates morbidity of the hepatobiliary tract disease

Complications arising from infection with the carcinogenic liver fluke Opisthorchis viverrini cause substantial morbidity and mortality in Thailand and adjacent lower Mekong countries. In parallel, the incidence rate of diabetes mellitus (DM) is increasing in this same region, and indeed worldwide. Many residents in opisthorchiasis-endemic regions also exhibit DM, but the hepatobiliary disease arising during the co-occurrence of these two conditions remains to be characterized. Here, the histopathological profile during co-occurrence of opisthorchiasis and DM was investigated in a rodent model of human opisthorchiasis in which diabetes was induced with streptozotocin. The effects of excretory/secretory products from the liver fluke, O. viverrini (OVES) on hepatocyte and cholangiocyte responses during hyperglycemic conditions also were monitored. Both the liver fluke-infected hamsters (OV group) and hamsters with DM lost weight compared to control hamsters. Weight loss was even more marked in the hamsters with both opisthorchiasis and DM (OD group). Hypertrophy of hepatocytes, altered biliary canaliculi, and biliary hyperplasia were more prominent in the OD group, compared with OV and DM groups. Profound oxidative DNA damage, evidenced by 8-oxo-2'-deoxyguanosine, proliferating cell nuclear antigen, and periductal fibrosis characterized the OD compared to OV and DM hamsters. Upregulation of expression of cytokines in response to infection and impairment of the pathway for insulin receptor substrate (IRS)/phosphatidylinositol-3-kinases (PI3K)/protein kinase B (AKT) signaling attended these changes. In vitro, OVES and glucose provoked time- and dose-dependent effects on the proliferation of both hepatocytes and cholangiocytes. In overview, the co-occurrence of opisthorchiasis and diabetes exacerbated pathophysiological damage to the hepatobiliary tract. We speculate that opisthorchiasis and diabetes together aggravate hepatobiliary pathogenesis through an IRS/PI3K/AKT-independent pathway.

Excess cost burden of diabetes in Southern India: a clinic-based, comparative cost-of-illness study

Background

There are few data on excess direct and indirect costs of diabetes in India and limited data on rural costs of diabetes. We aimed to further explore these aspects of diabetes burdens using a clinic-based, comparative cost-of-illness study.

Methods

Persons with diabetes (n = 606) were recruited from government, private, and rural clinics and compared to persons without diabetes matched for age, sex, and socioeconomic status (n = 356). We used interviewer-administered questionnaires to estimate direct costs (outpatient, inpatient, medication, laboratory, and procedures) and indirect costs [absence from (absenteeism) or low productivity at (presenteeism) work]. Excess costs were calculated as the difference between costs reported by persons with and without diabetes and compared across settings. Regression analyses were used to separately identify factors associated with total direct and indirect costs.

Results

Annual excess direct costs were highest amongst private clinic attendees (INR 19 552, US$425) and lowest amongst government clinic attendees (INR 1204, US$26.17). Private clinic attendees had the lowest excess absenteeism (2.36 work days/year) and highest presenteeism (0.06 work days/year) due to diabetes. Government clinic attendees reported the highest absenteeism (7.48 work days/year) and lowest presenteeism (-0.31 work days/year). Ten additional years of diabetes duration was associated with 11% higher direct costs (p < 0.001). Older age (p = 0.02) and longer duration of diabetes (p < 0.001) were associated with higher total lost work days.

Conclusions

Excess health expenditures and lost productivity amongst individuals with diabetes are substantial and different across care settings. Innovative solutions are needed to cope with diabetes and its associated cost burdens in India.

Ventromedial hypothalamic lesions downregulate multiple immune signaling pathways in rat pancreatic islets

It was recently reported that ventromedial hypothalamic lesions change the expression of cell proliferation-related genes and metabolism-related genes in rat pancreatic islets. This study has examined how gene families involved in immune responses are regulated in rat pancreatic islets after VMH lesions formation. Total pancreatic islets RNA was extracted, and differences in the gene expression profiles between rats at day 3 after VMH lesioning and sham-VMH-lesioned rats were investigated using DNA microarray and real-time polymerase chain reaction. VMH lesions downregulated multiple immune signaling pathways in rat pancreatic islets. Real-time polymerase chain reaction also confirmed that gene expressions of RT1 class II, locus Bb (RT1-Bb) was up-regulated and Spi-B transcription factor (Spib) was downregulated at day 3 after the VMH lesions. Ventromedial hypothalamic lesions may change the expression of multiple immune response genes in rat pancreatic islets.

Blastomyces Tenosynovitis of the Foot and Ankle: A Case Report and Review of the Literature

Deep fungal infection localized to the foot is not common, and when it occurs it often affects immunocompromised individuals. In this report, we describe the case of an adult diabetic patient who suffered with with Blastomycosis infection of the flexor digitorum longus and peroneal tendon sheaths. The condition was treated with systemic antifungal therapy and surgical debridement.

Insulin and the Brain: A Sweet Relationship With Intensive Care

BACKGROUND

Insulin receptors (IRs) in the brain have unique molecular features and a characteristic pattern of distribution. Their possible functions extend beyond glucose utilization. In this systematic review, we explore the interactions between insulin and the brain and its implications for anesthesiologists, critical care physicians, and other medical disciplines.

METHODS

A literature search of published preclinical and clinical studies between 1978 and 2014 was conducted, yielding 5996 articles. After applying inclusion and exclusion criteria, 92 studies were selected for this systematic review.

RESULTS

The IRs have unique molecular features, pattern of distribution, and mechanism of action. It has effects on neuronal function, metabolism, and neurotransmission. The IRs are involved in neuronal apoptosis and neurodegenerative processes.

CONCLUSION

In this systematic review, we present a close relationship between insulin and the brain, with discernible effects on memory, learning abilities, and motor functions. The potential therapeutic effects extend from acute brain insults such as traumatic brain injury, brain ischemia, and hemorrhage, to chronic neurodegenerative diseases such as Alzheimer and Parkinson disease. An understanding of the wider effects of insulin conveyed in this review will prompt anaesthesiologists and critical care physicians to consider its therapeutic potential and guide future studies.

Glibenclamide attenuates myocardial injury by lipopolysaccharides in streptozotocin-induced diabetic mice

BACKGROUND

Sepsis is a common disease that continues to increase in incidence in the world. Diseases, such as diabetes mellitus, may make the situation worse. Diabetic patients are at increased risk for common infections. This study was designed to investigate the role of glibenclamide on myocardial injury by lipopolysaccharides (LPS) in streptozotocin induced diabetic mice (STZ-mice).

METHODS

LPS was used to induce endotoxemia in STZ-mice. Heart rate and mean arterial pressure were measured by MPA-HBBS. Serum epinephrine level was measured by enzyme-linked immunosorbent assays (ELISA). Myocardial injury was examined by light and transmission electron microscope and TUNEL staining. Macrophage infiltration was measured by immunohistochemistry. Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) levels in myocardial tissue and serum in STZ-mice, and in conditional medium of primary cultured peritoneal macrophages were determined by ELISA. Nalp3 and Caspase-1 protein levels were measured by Western blotting analysis.

RESULTS

STZ administration decreased body weight and increased blood glucose in C57BL/6 mice. LPS injection caused decreases of heart rate and mean arterial pressure, and elevated serum epinephrine level in C57BL/6 mice. Compared with control mice without STZ treatment, LPS induced more severe myocardial injury and macrophage infiltration in STZ-mice, which was attenuated by pretreatment of glibenclamide. LPS stimulation enhanced the levels of IL-1β and TNF-α in both cardiac tissue and serum. Glibenclamide pretreatment significantly inhibited the serum levels of pro-inflammatory cytokines. Either high glucose or LPS increased the levels of IL-1β and TNF-α in the conditional medium of peritoneal macrophages. Glibenclamide treatment suppressed the increase of IL-1β level induced by high glucose and LPS. Furthermore, Nalp3 and Caspase-1 levels were markedly increased by high glucose plus LPS, and both proteins were significantly inhibited by glibenclamide treatment.

CONCLUSIONS

We conclude that glibenclamide could attenuate myocardial injury induced by LPS challenge in STZ-mice, which was possibly related to inhibiting inflammation through Nalp3 inflammasomes.