Genetic risk factors for type 1 diabetes

Physical Activity, Genetic Susceptibility, and the Risk of Latent Autoimmune Diabetes in Adults and Type 2 Diabetes

PURPOSE

Physical activity (PA) has been linked to a reduced risk of type 2 diabetes by reducing weight and improving insulin sensitivity. We investigated whether PA is associated with a lower incidence of latent autoimmune diabetes in adults (LADA) and whether the association is modified by genotypes of human leukocyte antigen (HLA), transcription factor 7-like 2 (TCF7L2)-rs7903146, or the fat mass and obesity-associated gene, FTO-rs9939609.

METHODS

We combined data from a Swedish case-control study and a Norwegian prospective study including 621 incident cases of LADA and 3596 cases of type 2 diabetes. We estimated adjusted pooled relative risks (RRs) and 95% CI of diabetes in relation to high (≥ 30 minutes of moderate activity 3 times/week) self-reported leisure time PA, compared to sedentariness.

RESULTS

High PA was associated with a reduced risk of LADA (RR 0.61; CI, 0.43-0.86), which was attenuated after adjustment for body mass index (BMI) (RR 0.90; CI, 0.63-1.29). The reduced risk applied only to noncarriers of HLA-DQB1 and -DRB1 (RR 0.49; CI, 0.33-0.72), TCF7L2 (RR 0.62; CI, 0.45-0.87), and FTO (RR 0.51; CI, 0.32-0.79) risk genotypes. Adjustment for BMI attenuated but did not eliminate these associations. For type 2 diabetes, there was an inverse association with PA (RR 0.49; CI, 0.42-0.56), irrespective of genotype.

MAIN CONCLUSIONS

Our findings indicate that high PA is associated with a reduced risk of LADA in individuals without genetic susceptibility.

A non-coding RNASEH1 gene variant associates with type 1 diabetes and interacts with HLA tagSNPs in families from Colombia

OBJECTIVES

RNASEH1 gene has recently been associated with type 1 diabetes (T1D) in Colombia. The purpose of this study was to fine mapping the putative functional variant in RNASEH1 and testing its interaction with HLA tagSNPs.

METHODS

Two-hundred nuclear families with T1D were included in this study. Probands were tested for GAD65 and IA-2 autoantibodies. Genotyping was performed using 20 coding tagSNPs uncovered through Sanger sequencing (N = 96), in addition to 23 tagSNPs chosen from 1000genomes to cover the extent of the gene region. Also, 45 tagSNPs for classic HLA alleles associated with T1D were also genotyped. The transmission disequilibrium test (TDT) was used to test for association and a multiple testing correction was made using permutation. Interaction between RNASEH1 variants and HLA was evaluated by means of the M-TDT test.

RESULTS

We identified 20 variants (15 were novel) in the 96 patients sequenced. None of these variants were in linkage disequilibrium. In total, 43 RNASEH1 variants were genotyped in the 200 families. Association between T1D and rs7607888 was identified (P = .002). Haplotype analysis involving rs7607888 variant revealed even stronger association with T1D (most significative P = .0003). HLA tagSNPs displayed stronger associations (OR = 6.39, 95% CI = 4.33-9.44, P-value = 9.74E-28). Finally, we found several statistically significant interactions of HLA variants with rs7607888 (P-value ranged from 8.77E-04 to 5.33E-12).

CONCLUSION

Our results verify the association of rs7607888 in RNASEH1 gene with T1D. It is also shown in the interaction between RNASEH1 and HLA for conveying risk to T1D in Northwest Colombia. Work is underway aiming to identify the actual classic HLA alleles associated with the tagSNPs tested here.

Challenges in the diagnosis of diabetes type in pediatrics

The incidence of diabetes, both type 1 and type 2, is increasing. Health outcomes in pediatric diabetes are currently poor, with trends indicating that they are worsening. Minority racial/ethnic groups are disproportionately affected by suboptimal glucose control and have a higher risk of acute and chronic complications of diabetes. Correct clinical management starts with timely and accurate classification of diabetes, but in children this is becoming increasingly challenging due to high prevalence of obesity and shifting demographic composition. The growing obesity epidemic complicates classification by obesity's effects on diabetes. Since the prevalence and clinical characteristics of diabetes vary among racial/ethnic groups, migration between countries leads to changes in the distribution of diabetes types in a certain geographical area, challenging the clinician's ability to classify diabetes. These challenges must be addressed to correctly classify diabetes and establish an appropriate treatment strategy early in the course of disease for all. This may be the first step in improving diabetes outcomes across racial/ethnic groups. This review will discuss the pitfalls in the current diabetes classification scheme that is leading to increasing overlap between diabetes types and heterogeneity within each type. It will also present proposed alternative classification schemes and approaches to understanding diabetes type that may improve the timely and accurate classification of pediatric diabetes type.

Dog leucocyte antigen (DLA) class II haplotypes and risk of canine diabetes mellitus in specific dog breeds

Background

Canine diabetes mellitus (DM) is a common endocrine disease in domestic dogs. A number of pathological mechanisms are thought to contribute to the aetiopathogenesis of relative or absolute insulin deficiency, including immune-mediated destruction of pancreatic beta cells. DM risk varies considerably between different dog breeds, suggesting that genetic factors are involved and contribute susceptibility or protection. Associations of particular dog leucocyte antigen (DLA) class II haplotypes with DM have been identified, but investigations to date have only considered all breeds pooled together. The aim of this study was to analyse an expanded data set so as to identify breed-specific diabetes-associated DLA haplotypes.

Methods

The 12 most highly represented breeds in the UK Canine Diabetes Register were selected for study. DLA-typing data from 646 diabetic dogs and 912 breed-matched non-diabetic controls were analysed to enable breed-specific analysis of the DLA. Dogs were genotyped for allelic variation at DLA-DRB1, -DQA1, -DQB1 loci using DNA sequence-based typing. Genotypes from all three loci were combined to reveal three-locus DLA class II haplotypes, which were evaluated for statistical associations with DM. This was performed for each breed individually and for all breeds pooled together.

Results

Five dog breeds were identified as having one or more DLA haplotype associated with DM susceptibility or protection. Four DM-associated haplotypes were identified in the Cocker Spaniel breed, of which one haplotype was shared with Border Terriers. In the three breeds known to be at highest risk of DM included in the study (Samoyed, Tibetan Terrier and Cairn Terrier), no DLA haplotypes were found to be associated with DM.

Conclusions

Novel DLA associations with DM in specific dog breeds provide further evidence that immune response genes contribute susceptibility to this disease in some cases. It is also apparent that DLA may not be contributing obvious or strong risk for DM in some breeds, including the seven breeds analysed for which no associations were identified.

Risk factors for type 1 diabetes, including environmental, behavioural and gut microbial factors: a case-control study

Type 1 diabetes (T1D) is a common autoimmune disease that is characterized by insufficient insulin production. The onset of T1D is the result of gene-environment interactions. Sociodemographic and behavioural factors may contribute to T1D, and the gut microbiota is proposed to be a driving factor of T1D. An integrated preventive strategy for T1D is not available at present. This case-control study attempted to estimate the exposure linked to T1D to identify significant risk factors for healthy children. Forty children with T1D and 56 healthy controls were included in this study. Anthropometric, socio-economic, nutritional, behavioural, and clinical data were collected. Faecal bacteria were investigated by molecular methods. The findings showed, in multivariable model, that the risk factors for T1D include higher Firmicutes levels (OR 7.30; IC 2.26-23.54) and higher carbohydrate intake (OR 1.03; IC 1.01-1.05), whereas having a greater amount of Bifidobacterium in the gut (OR 0.13; IC 0.05 - 0.34) was a protective factor for T1D. These findings may facilitate the development of preventive strategies for T1D, such as performing genetic screening, characterizing the gut microbiota, and managing nutritional and social factors.

Gluten Free Diet for the Management of Non Celiac Diseases: The Two Sides of the Coin

A lifelong adherence to a gluten-free (GF) diet is currently the only treatment for Celiac disease (CD), an autoimmune disorder that arises after gluten ingestion in individuals who are genetically predisposed. The gluten intake exerts toxic effects through several pathways involving gut barrier integrity, intestinal microbiota composition and immune system stimulation. However, despite the great benefit of GF diet for CD patients, its use has been debated. Indeed, individuals who adopt this diet regime may be at risk of nutrient deficiencies. Emerging evidence supports a beneficial effect of a GF diet also for other pathological conditions, including gluten-related disorders (GRD) often associated to CD, such as Non celiac gluten sensitivity (NCGS) and Dermatitis Herpetiforme (DH) as well as Irritable bowel syndrome (IBS) and Diabetes. This suggests a pathogenic role of gluten in these conditions. Despite the growing popularity of GF diet among consumers, to date, there are limited evidences supporting its use for the management of non-celiac diseases. Therefore, in this review, we discuss whether the GF diet could really improve the general quality of life of patients with GRD and non-GRD conditions, keeping in mind its sensorial limitations and nutritional inadequacies. In addition, we discuss the current motivations, leading to the use of a GF diet, despite the inferior quality of GF products respect to those containing gluten.

Epigenetic Effects of Gut Metabolites: Exploring the Path of Dietary Prevention of Type 1 Diabetes

Type 1 diabetes (T1D) has increased over the past half century and has now become the second most frequent autoimmune disease in childhood and one of major public health concern worldwide. Evidence suggests that modern lifestyles and rapid environmental changes are driving factors that underlie this increase. The integration of these two factors brings about changes in food intake. This, in turn, alters epigenetic regulations of the genome and intestinal microbiota composition, which may ultimately play a role in pathogenesis of T1D. Recent evidence shows that dysbiosis of the gut microbiota is closely associated with T1D and that a dietary intervention can influence epigenetic changes associated with this disease and may modify gene expression patterns through epigenetic mechanisms. In this review focus on how a diet can shape the gut microbiome, its effect on the epigenome in T1D, and the future of T1D management by microbiome therapy.

Confirmation and Identification of Biomarkers Implicating Environmental Triggers in the Pathogenesis of Type 1 Diabetes

Multiple environmental triggers have been proposed to explain the increased incidence of type 1 diabetes (T1D). These include viral infections, microbiome disturbances, metabolic disorders, and vitamin D deficiency. Here, we used ELISA to examine blood plasma from juvenile T1D subjects and age-matched controls for the abundance of several circulating factors relevant to these hypotheses. We screened plasma for sCD14, mannose binding lectin (MBL), lipopolysaccharide binding protein (LBP), c-reactive protein (CRP), fatty acid binding protein 2 (FABP2), human growth hormone, leptin, total adiponectin, high molecular weight (HMW) adiponectin, total IgG, total IgA, total IgM, endotoxin core antibodies (EndoCAbs), 25(OH) vitamin D, vitamin D binding protein, IL-7, IL-10, IFN-γ, TNF-α, IL-17A, IL-18, and IL-18BPa. Subjects also were tested for prevalence of antibodies targeting adenovirus, parainfluenza 1/2/3, Coxsackievirus, cytomegalovirus, Epstein-Barr virus viral capsid antigen (EBV VCA), herpes simplex virus 1, and Saccharomyces cerevisiae. Finally, all subjects were screened for presence and abundance of autoantibodies targeting islet cell cytoplasmic proteins (ICA), glutamate decarboxylase 2 (GAD65), zinc transporter 8 (ZNT8), insulinoma antigen 2 (IA-2), tissue transglutaminase, and thyroid peroxidase, while β cell function was gauged by measuring c-peptide levels. We observed few differences between control and T1D subjects. Of these, we found elevated sCD14, IL-18BPa, and FABP2, and reduced total IgM. Female T1D subjects were notably elevated in CRP levels compared to control, while males were similar. T1D subjects also had significantly lower prevalence of EBV VCA antibodies compared to control. Lastly, we observed that c-peptide levels were significantly correlated with leptin levels among controls, but this relationship was not significant among T1D subjects. Alternatively, adiponectin levels were significantly correlated with c-peptide levels among T1D subjects, while controls showed no relationship between these two factors. Among T1D subjects, the highest c-peptide levels were associated with the lowest adiponectin levels, an indication of insulin resistance. In total, from our examination we found limited data that strongly support any of the hypotheses investigated. Rather, we observed an indication of unexplained monocyte/macrophage activation in T1D subjects judging from elevated levels of sCD14 and IL-18BPa. These observations were partnered with unique associations between adipokines and c-peptide levels among T1D subjects.

Fulminant type 1 diabetes: A comprehensive review of an autoimmune condition

Fulminant type 1 diabetes (FT1D) is a subset of type 1 diabetes characterized by extremely rapid pancreatic β-cell destruction with aggressive progression of hyperglycaemia and ketoacidosis. It was initially classified as idiopathic type 1 diabetes due to the absence of autoimmune markers. However, subsequent studies provide evidences supporting the involvement of autoimmunity in rapid β-cell loss in FT1D pathogenesis, which are crucial for FT1D being an autoimmune disease. This article highlights the role of immunological aspects in FT1D according to the autoimmune-associated genetic background, viral infection, innate immunity, adaptive immunity, and pancreas histology.

N-glycans as functional effectors of genetic and epigenetic disease risk

N-glycosylation is a frequent modification of proteins, essential for all domains of life. N-glycan biosynthesis is a dynamic, complex, non-templated process, wherein specific glycoforms are modulated by various microenvironmental cues, cellular signals and local availability of dedicated enzymes and sugar precursors. This intricate regulatory network comprises hundreds of proteins, whose activity is dependent on both sequence of implicated genes and the regulation of their expression. In this regard, variation in N-glycosylation patterns stems from either gene polymorphisms or from stable epigenetic regulation of gene expression in different individuals. Moreover, epigenome alters in response to various environmental factors, representing a direct link between environmental exposure and changes in gene expression, that are subsequently reflected through altered N-glycosylation. N-glycosylation itself has a fundamental role in numerous biological processes, ranging from protein folding, cellular homeostasis, adhesion and immune regulation, to the effector functions in multiple diseases. Moreover, specific modification of the glycan structure can modulate glycoprotein's biological function or direct the faith of the entire cell, as seen on the examples of antibodies and T cells, respectively. Since immunoglobulin G is one of the most profoundly studied glycoproteins in general, the focus of this review will be on its N-glycosylation changes and their functional implications. By deepening the knowledge on the mechanistic roles that certain glycoforms exert in differential pathological processes, valuable insight into molecular perturbations occurring during disease development could be obtained. The prospect of resolving the exact biological pathways involved offers a potential for the development of new therapeutic interventions and molecular tools that would aid in prognosis, early referral and timely treatment of multiple disease conditions.

The protective effects of human milk-derived peptides on the pancreatic islet biology

Several epidemiological studies support the protective role of breastfeeding in reducing the risk for type 1 diabetes. Human breast milk is the perfect nutrition for infants and contains many complex proteins, lipids and carbohydrates. In this study, we examined the physiological effects of human milk-derived opioid peptides, β-casomorphins (BCM), and compared them with bovine-milk-derived opioid peptides on pancreatic hormone regulation and β-cell regeneration. Exposure of wild-type zebrafish embryos to 50 µg/ml of human BCM-5 and -7 from 3 days post fertilisation until 6 days post fertilisation resulted in an increased insulin domain of expression while exposure to bovine BCM-5 and -7 significantly reduced the insulin domain of expression as analysed by whole-mount in situ hybridisation. These changes may be accounted for by reduced insulin expression or β-cell number and were mitigated by the µ-opioid receptor antagonist, naloxone. The effect of BCM on β-cell regeneration was assessed following ablation of β-cells in Tg (ins: CFP-NTR) zebrafish from 3 days post fertilisation to 4 days post fertilisation, followed by exposure of bovine and human BCM-5 and -7 (50 µg/ml) from 4 days post fertilisation until 7 days post fertilisation. The regenerative capacity of β-cells was not impeded following exposure to human BCM-5 and -7, whereas the capacity of β-cells to regenerate following bovine BCM-5 and -7 exposure was reduced. Our data suggest that human BCM-5 and -7 may promote β-cell development and enable the regeneration of β-cells, while the bovine-milk-derived peptides, BCM-5 and -7, play an opposite role. These data may provide some biological explanation for the protective effect of breastfeeding on the development of type 1 diabetes.

Evaluation for type 1 diabetes associated autoantibodies in diabetic and non-diabetic Australian terriers and Samoyeds

Background

Evidence for an autoimmune etiology in canine diabetes is inconsistent and could vary based on breed. Previous studies demonstrated that small percentages of diabetic dogs possess autoantibodies to antigens known to be important in human type 1 diabetes, but most efforts involved analysis of a wide variety of breeds. The objective of this study was to evaluate the presence of glutamic acid decarboxylase 65 (GAD65), insulinoma-associated protein 2 (IA-2), and zinc transporter 8 (ZnT8) autoantibodies in diabetic and non-diabetic Australian Terriers and Samoyeds, two breeds with comparatively high prevalence of diabetes, in the United States.

Results

There was no significant difference in the proportion of samples considered positive for GAD65 or ZnT8 autoantibodies in either breed evaluated, or for IA-2 autoantibodies in Australian Terriers (p > 0.05). The proportion of IA-2 autoantibody positive samples was significantly higher in diabetic versus non-diabetic Samoyeds (p = 0.003), but substantial overlap was present between diabetic and non-diabetic groups.

Conclusions

The present study does not support GAD65, IA-2, or ZnT8 autoantibodies as markers of autoimmunity in canine diabetes in Samoyeds or Australian Terriers as measured using human antigen sandwich enzyme-linked immunosorbent (ELISA) assays. Future studies using canine specific assays as well as investigation for alternative markers of autoimmunity in these and other canine breeds are warranted.

Promising role of medicinal plants in the regulation and management of male erectile dysfunction

Male erectile dysfunction (ED) refers to incompetency to reaching and retaining adequate penile tumescence for sexual intercourse. Over 152 million men globally suffer from ED and by 2025, the number of affected individuals is anticipated to be around 322 million. Pharmacological and nonpharmacological therapies such as phosphodiesterase (PDE) inhibitors, alprostadil, penile prosthesis surgery, and hormonal replacement are available for management and recuperation of ED. Nevertheless, such therapies are reported to have adverse effects as well as life-threatening. Accordingly, diversity of medicinal plant species and bioactive active compounds are preferred as therapeutic options because they are natural, abundant, available, low-cost and cause fewer or no side effects. This current review will emphasise the aetiology, risk factors, mechanisms underlying the pathophysiology of ED, treatments of ED as well as their side effects. It also provides medicinal plants that are proven effective in vivo and in vitro for the mitigation and treatment of male ED. This knowledge could be used in the future in drug discovery for the development of more natural drugs with no side effects.

Sphingolipids in Type 1 Diabetes: Focus on Beta-Cells

Type 1 diabetes (T1DM) is a chronic autoimmune disease, with a strong genetic background, leading to a gradual loss of pancreatic beta-cells, which secrete insulin and control glucose homeostasis. Patients with T1DM require life-long substitution with insulin and are at high risk for development of severe secondary complications. The incidence of T1DM has been continuously growing in the last decades, indicating an important contribution of environmental factors. Accumulating data indicates that sphingolipids may be crucially involved in T1DM development. The serum lipidome of T1DM patients is characterized by significantly altered sphingolipid composition compared to nondiabetic, healthy probands. Recently, several polymorphisms in the genes encoding the enzymatic machinery for sphingolipid production have been identified in T1DM individuals. Evidence gained from studies in rodent islets and beta-cells exposed to cytokines indicates dysregulation of the sphingolipid biosynthetic pathway and impaired function of several sphingolipids. Moreover, a number of glycosphingolipids have been suggested to act as beta-cell autoantigens. Studies in animal models of autoimmune diabetes, such as the Non Obese Diabetic (NOD) mouse and the LEW.1AR1-iddm (IDDM) rat, indicate a crucial role of sphingolipids in immune cell trafficking, islet infiltration and diabetes development. In this review, the up-to-date status on the findings about sphingolipids in T1DM will be provided, the under-investigated research areas will be identified and perspectives for future studies will be given.

Time trends in incidence of diabetes mellitus in Austrian children and adolescents <15 years (1989-2017)

OBJECTIVE

To analyze the time trends of nationwide diabetes incidence <15 years of age from 1989 until 2017 in Austria.

METHODS

The Austrian Diabetes Incidence Study Group registers all newly diagnosed patients with diabetes mellitus <15 years of age in a prospective population-based study. The diabetes type was classified on the basis of clinical and laboratory findings according to American Diabetes Association criteria. Time trends were estimated by Joinpoint analysis.

RESULTS

1311 patients were diagnosed with type 1 diabetes (T1D) between 1989 and 1999 and 4624 patients with any type of diabetes (1999-2017). T1D accounted for the majority of cases (94.2%), 1.8% were classified as type 2 (T2D) and 4.0% as other specific types of diabetes (1999-2017). In the total cohort (age 0 to <15 years), a constant increase until 2012 (annual percent change [APC] 4.5, 95% confidence interval [CI]: 3.94, 5.06) was observed, followed by a leveling off with a corresponding drop (APC 0.28, 95%CI: -3.94, 4.69). This observation was mainly driven by the dynamic in the youngest age group (0-4 years) with a steep increase until 2007 (APC 7.1, 95%CI: 5.05, 9.19) and a decrease from 2007 to 2017 (APC -0.86, 95%CI: 4.41, 2.82). No significant increase of T2D <15 years was detected. Over the observed time period (APC = 3.7, 95%CI: -0.30, 7.78).

CONCLUSIONS

The incidence of T1D is declining in young children aged 0 to 4 years, but is still rising in children 5 to 14 years in Austria. Incidence of T2D did not increase significantly and other specific types of diabetes occur twice as often compared to T2D.

Mass cytometry and type 1 diabetes research in the age of single-cell data science

PURPOSE OF REVIEW

New single-cell tec. hnologies developed over the past decade have considerably reshaped the biomedical research landscape, and more recently have found their way into studies probing the pathogenesis of type 1 diabetes (T1D). In this context, the emergence of mass cytometry in 2009 revolutionized immunological research in two fundamental ways that also affect the T1D world: first, its ready embrace by the community and rapid dissemination across academic and private science centers alike established a new standard of analytical complexity for the high-dimensional proteomic stratification of single-cell populations; and second, the somewhat unexpected arrival of mass cytometry awoke the flow cytometry field from its seeming sleeping beauty stupor and precipitated substantial technological advances that by now approach a degree of analytical dimensionality comparable to mass cytometry.

RECENT FINDINGS

Here, we summarize in detail how mass cytometry has thus far been harnessed for the pursuit of discovery studies in T1D science; we provide a succinct overview of other single-cell analysis platforms that already have been or soon will be integrated into various T1D investigations; and we briefly consider how effective adoption of these technologies requires an adjusted model for expense allocation, prioritization of experimental questions, division of labor, and recognition of scientific contributions.

SUMMARY

The introduction of contemporary single-cell technologies in general, and of mass cytometry, in particular, provides important new opportunities for current and future T1D research; the necessary reconfiguration of research strategies to accommodate implementation of these technologies, however, may both broaden research endeavors by fostering genuine team science, and constrain their actual practice because of the need for considerable investments into infrastructure and technical expertise.

Assessing effector T cells in type 1 diabetes

PURPOSE OF REVIEW

The role of T cells specific for islet autoantigens is proven in pathogenesis of type 1 diabetes. Recently, there has been rapid expansion in the number of T-cell subsets identified, this has coincided with an increase in the repertoire of reported islet antigens mainly through the discovery of novel epitopes. A discussion of how these marry together is now warranted and timely.

RECENT FINDINGS

In this review, we will discuss the autoreactivity against neo-epitopes. We then explore the growing array of T-cell subsets for both CD4 T cells, including follicular and peripheral T helper cells, and CD8 T cells, discussing evolution from naïve to exhausted phenotypes. Finally, we detail how subsets correlate with disease stage and loss of β-cell function and are impacted by immunotherapy.

SUMMARY

The expanding list of T-cell subsets may be potentially encouraging in terms of elucidating disease mechanisms and have a role as biomarkers for disease progression. Furthermore, T-cell subsets can be used in stratifying patients for clinical trials and for monitoring immunotherapy outcomes. However, the definition of subsets needs to be refined in order to ensure that there is a uniform approach in designating T-cell subset attributes that is globally applied.

UBASH3A deficiency accelerates type 1 diabetes development and enhances salivary gland inflammation in NOD mice

Recent advances in genetic analyses have significantly refined human type 1 diabetes (T1D) associated loci. The goal of such effort is to identify the causal genes and have a complete understanding of the molecular pathways that independently or interactively influence cellular processes leading to the destruction of insulin producing pancreatic β cells. UBASH3A has been suggested as the underlying gene for a human T1D associated region on chromosome 21. To further evaluate the role of UBASH3A in T1D, we targeted Ubash3a in NOD mice using zinc-finger nuclease mediated mutagenesis. In both 10-week-old females and males, significantly more advanced insulitis was observed in UBASH3A-deficient than in wild-type NOD mice. Consistently, UBASH3A-deficient NOD mice developed accelerated T1D in both sexes, which was associated with increased accumulation of β-cell autoreactive T cells in the spleen and pancreatic lymph node. Adoptive transfer of splenic T cells into NOD.Rag1^-/- mice demonstrated that UBASH3A deficiency in T cells was sufficient to promote T1D development. Our results provide strong evidence to further support a role of UBASH3A in T1D. In addition to T1D, UBASH3A deficiency also promoted salivary gland inflammation in females, demonstrating its broad impact on autoimmunity.

Enteroviruses and T1D: Is It the Virus, the Genes or Both which Cause T1D

Type 1 diabetes (T1D) is a chronic autoimmune disorder that results from the selective destruction of insulin-producing β-cells in the pancreas. Up to now, the mechanisms triggering the initiation and progression of the disease are, in their complexity, not fully understood and imply the disruption of several tolerance networks. Viral infection is one of the environmental factors triggering diabetes, which is initially based on the observation that the disease’s incidence follows a periodic pattern within the population. Moreover, the strong correlation of genetic susceptibility is a prerequisite for enteroviral infection associated islet autoimmunity. Epidemiological data and clinical findings indicate enteroviral infections, mainly of the coxsackie B virus family, as potential pathogenic mechanisms to trigger the autoimmune reaction towards β-cells, resulting in the boost of inflammation following β-cell destruction and the onset of T1D. This review discusses previously identified virus-associated genetics and pathways of β-cell destruction. Is it the virus itself which leads to β-cell destruction and T1D progression? Or is it genetic, so that the virus may activate auto-immunity and β-cell destruction only in genetically predisposed individuals?

Direct Lineage Reprogramming: Harnessing Cell Plasticity between Liver and Pancreas

Direct lineage reprogramming of abundant and accessible cells into therapeutically useful cell types holds tremendous potential in regenerative medicine. To date, a number of different cell types have been generated by lineage reprogramming methods, including cells from the neural, cardiac, hepatic, and pancreatic lineages. The success of this strategy relies on developmental biology and the knowledge of cell-fate-defining transcriptional networks. Hepatocytes represent a prime target for β cell conversion for numerous reasons, including close developmental origin, accessibility, and regenerative potential. We present here an overview of pancreatic and hepatic development, with a particular focus on the mechanisms underlying the divergence between the two cell lineages. Additionally, we discuss to what extent this lineage relationship can be exploited in efforts to reprogram one cell type into the other and whether such an approach may provide a suitable strategy for regenerative therapies of diabetes.

Motifs of Three HLA-DQ Amino Acid Residues (α44, β57, β135) Capture Full Association With the Risk of Type 1 Diabetes in DQ2 and DQ8 Children

HLA-DQA1 and -DQB1 are strongly associated with type 1 diabetes (T1D), and DQ8.1 and DQ2.5 are major risk haplotypes. Next-generation targeted sequencing of HLA-DQA1 and -DQB1 in Swedish newly diagnosed 1- to 18 year-old patients (n = 962) and control subjects (n = 636) was used to construct abbreviated DQ haplotypes, converted into amino acid (AA) residues, and assessed for their associations with T1D. A hierarchically organized haplotype (HOH) association analysis allowed 45 unique DQ haplotypes to be categorized into seven clusters. The DQ8/9 cluster included two DQ8.1 risk and the DQ9 resistant haplotypes, and the DQ2 cluster included the DQ2.5 risk and DQ2.2 resistant haplotypes. Within each cluster, HOH found residues α44Q (odds ratio [OR] 3.29, P = 2.38 * 10^-85) and β57A (OR 3.44, P = 3.80 * 10^-84) to be associated with T1D in the DQ8/9 cluster representing all ten residues (α22, α23, α44, α49, α51, α53, α54, α73, α184, β57) due to complete linkage disequilibrium (LD) of α44 with eight such residues. Within the DQ2 cluster and due to LD, HOH analysis found α44C and β135D to share the risk for T1D (OR 2.10, P = 1.96 * 10^-20). The motif "QAD" of α44, β57, and β135 captured the T1D risk association of DQ8.1 (OR 3.44, P = 3.80 * 10^-84), and the corresponding motif "CAD" captured the risk association of DQ2.5 (OR 2.10, P = 1.96 * 10^-20). Two risk associations were related to GAD65 autoantibody (GADA) and IA-2 autoantibody (IA-2A) but in opposite directions. CAD was positively associated with GADA (OR 1.56, P = 6.35 * 10^-8) but negatively with IA-2A (OR 0.59, P = 6.55 * 10^-11). QAD was negatively associated with GADA (OR 0.88; P = 3.70 * 10^-3) but positively with IA-2A (OR 1.64; P = 2.40 * 10^-14), despite a single difference at α44. The residues are found in and around anchor pockets 1 and 9, as potential T-cell receptor contacts, in the areas for CD4 binding and putative homodimer formation. The identification of three HLA-DQ AAs (α44, β57, β135) conferring T1D risk should sharpen functional and translational studies.

Pancreatic β-cells in type 1 and type 2 diabetes mellitus: different pathways to failure

Loss of functional β-cell mass is the key mechanism leading to the two main forms of diabetes mellitus - type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Understanding the mechanisms behind β-cell failure is critical to prevent or revert disease. Basic pathogenic differences exist in the two forms of diabetes mellitus; T1DM is immune mediated and T2DM is mediated by metabolic mechanisms. These mechanisms differentially affect early β-cell dysfunction and eventual fate. Over the past decade, major advances have been made in the field, mostly delivered by studies on β-cells in human disease. These advances include studies of islet morphology and human β-cell gene expression in T1DM and T2DM, the identification and characterization of the role of T1DM and T2DM candidate genes at the β-cell level and the endoplasmic reticulum stress signalling that contributes to β-cell failure in T1DM (mostly IRE1 driven) and T2DM (mostly PERK-eIF2α dependent). Here, we review these new findings, focusing on studies performed on human β-cells or on samples obtained from patients with diabetes mellitus.

Haploinsufficiency of the NF1 gene is associated with protection against diabetes

Background

The hereditary predisposition to diabetes is only partially explained by genes identified so far. Neurofibromatosis type 1 (NF1) is a rare monogenic dominant syndrome caused by aberrations of the NF1 gene. Here, we used a cohort of 1410 patients with NF1 to study the association of the NF1 gene with type 1 (T1D) and type 2 diabetes (T2D).

Methods

A total of 1410 patients were confirmed to fulfil the National Institutes of Health diagnostic criteria for NF1 by individually reviewing their medical records. The patients with NF1 were compared with 14 017 controls matched for age, sex and area of residence as well as 1881 non-NF1 siblings of the patients with NF1. Register-based information on purchases of antidiabetic medication and hospital encounters related to diabetes were retrieved. The Cox proportional hazards model was used to calculate the relative risk for diabetes in NF1.

Results

Patients with NF1 showed a lower rate of T2D when compared with a 10-fold control cohort (HR 0.27, 95% CI 0.17 to 0.43) or with their siblings without NF1 (HR 0.28, 95% CI 0.16 to 0.47). The estimates remained practically unchanged after adjusting the analyses for history of obesity and dyslipidaemias. The rate of T1D in NF1 was decreased although statistically non-significantly (HR 0.58, 95% CI 0.27 to 1.25).

Conclusion

Haploinsufficiency of the NF1 gene may protect against T2D and probably T1D. Since NF1 negatively regulates the Ras signalling pathway, the results suggest that the Ras pathway may be involved in the pathogenesis of diabetes.

The CD137 Ligand Is Important for Type 1 Diabetes Development but Dispensable for the Homeostasis of Disease-Suppressive CD137+ FOXP3+ Regulatory CD4 T Cells

CD137 modulates type 1 diabetes (T1D) progression in NOD mice. We previously showed that CD137 expression in CD4 T cells inhibits T1D, but its expression in CD8 T cells promotes disease development by intrinsically enhancing the accumulation of β-cell-autoreactive CD8 T cells. CD137 is expressed on a subset of FOXP3+ regulatory CD4 T cells (Tregs), and CD137+ Tregs are the main source of soluble CD137. Soluble CD137 suppresses T cells in vitro by binding to the CD137 ligand (CD137L) upregulated on activated T cells. To further study how the opposing functions of CD137 are regulated, we successfully targeted Tnfsf9 (encoding CD137L) in NOD mice using the CRISPR/Cas9 system (designated NOD.Tnfsf9 -/-). Relative to wild-type NOD mice, T1D development in the NOD.Tnfsf9 -/- strain was significantly delayed, and mice developed less insulitis and had reduced frequencies of β-cell-autoreactive CD8 T cells. Bone marrow chimera experiments showed that CD137L-deficient hematopoietic cells were able to confer T1D resistance. Adoptive T cell transfer experiments showed that CD137L deficiency on myeloid APCs was associated with T1D suppression. Conversely, lack of CD137L on T cells enhanced their diabetogenic activity. Furthermore, neither CD137 nor CD137L was required for the development and homeostasis of FOXP3+ Tregs. However, CD137 was critical for the in vivo T1D-suppressive activity of FOXP3+ Tregs, suggesting that the interaction between CD137 and CD137L regulates their function. Collectively, our results provide new insights into the complex roles of CD137-CD137L interaction in T1D.

Perinatal factors and the risk of type 1 diabetes in childhood and adolescence-A register-based case-cohort study in Finland, years 1987 to 2009

OBJECTIVES

Our aim was to clarify previously reported associations and to explore new ones between various maternal background and perinatal factors and the risk of type 1 diabetes in childhood.

METHODS

We identified all children born 1 January 1987 to 31 December 2008 in Finland and diagnosed with type 1 diabetes by age 16 years or end of 2009 from the Special Reimbursement Register (n = 6862). A 10% random sample from each birth year cohort was selected as a reference cohort (n = 127 216). Information on perinatal factors was obtained from the Finnish Medical Birth Register.

RESULTS

Maternal diabetes (hazard ratios [HR] = 6.43; 95% confidence interval [CI] 5.35, 7.73), maternal asthma (HR = 1.23; 95% CI 1.06, 1.43), child's high birth length for gestational age (HR = 1.35; 95% CI 1.22, 1.51 highest vs lowest quintile) and premature or early term birth (HR = 1.21; 95% CI 1.05, 1.39 gestational weeks 33-36 and HR = 1.17; 95% CI 1.09, 1.26 gestational weeks 37-38 vs gestational weeks 39-40) was associated with an increased risk of type 1 diabetes when adjusted for several potential confounders. Maternal smoking during pregnancy (HR = 0.72; 95% CI 0.66, 0.77), high number of previous live births (HR = 0.65; 95% CI 0.55, 0.76 ≥ 4 vs 0 live births), and the child being born small for gestational age (HR = 0.80; 95% CI 0.67, 0.96) was associated with a decreased risk of type 1 diabetes.

CONCLUSIONS

Findings on maternal asthma and high birth length for gestational age increasing the risk of type 1 diabetes are novel and need to be confirmed. Our findings indicate that perinatal factors may play a role in the development of type 1 diabetes.

Evaluation of α-klotho level in insulin dependent diabetes mellitus (IDDM) children

Objectives Reduced levels of α-Klotho is associated with the pathogenesis of various diseases including diabetes. In type I diabetes, decrease in Klotho leads to apoptosis of β-cells of pancreases. The aim of this study was to evaluate the levels of α-Klotho in type I diabetic pediatric patients. Methods In this cross-sectional single centered study, 46 patients presenting type I diabetes mellitus (case group) and 78 control group under the age of 12, referred to our clinic were included in our study. Serum levels of soluble Klotho were measured by sandwich ELISA in case and control groups. Statistical analysis was conducted for the data recorded via questionnaire. Results Mean age of the patients in the case and control group was 7.65 ± 3.09 and 7 ± 2.37, respectively. Type I diabetes patients had a significant reduction in the levels of serum Klotho, as compared to controls (p<0.001). However, gender and age-based comparison between patient and control group was not significant. Conclusions This study reports a significant decrease in the serum levels of α-Klotho in type 1 diabetic patients. Low levels of Klotho can be associated with diabetic nephropathy and other comorbidities in these patients.

Microbiota derived factors as drivers of type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease caused by complex interactions between host genetics and environmental factors, culminating in the T-cell mediated destruction of the insulin producing cells in the pancreas. The rapid increase in disease frequency over the past 50 years or more has been too rapid to attribute to genetics. Dysbiosis of the gut microbiota is currently being widely investigated as a major contributor to environmental change driving increased T1D onset. In this chapter, we discuss the major changes in gut microbiota composition and function linked to T1D risk as well as the potential origin of these changes including infant diet, antibiotic use and host genetics. We examine the interaction between inflammation and gut barrier function and the dysbiotic gut microbiota that have been linked to T1D.

Application of magnetic nanoparticles in nucleic acid detection

Nucleic acid is the main material for storing, copying, and transmitting genetic information. Gene sequencing is of great significance in DNA damage research, gene therapy, mutation analysis, bacterial infection, drug development, and clinical diagnosis. Gene detection has a wide range of applications, such as environmental, biomedical, pharmaceutical, agriculture and forensic medicine to name a few. Compared with Sanger sequencing, high-throughput sequencing technology has the advantages of larger output, high resolution, and low cost which greatly promotes the application of sequencing technology in life science research. Magnetic nanoparticles, as an important part of nanomaterials, have been widely used in various applications because of their good dispersion, high surface area, low cost, easy separation in buffer systems and signal detection. Based on the above, the application of magnetic nanoparticles in nucleic acid detection was reviewed.

Decreased HLA-DQ expression on peripheral blood cells in children with varying number of beta cell autoantibodies

The risk for type 1 diabetes is strongly associated with HLA-DQ and the appearance of beta cell autoantibodies against either insulin, glutamate decarboxylase (GAD65), insulinoma-associated protein-2 (IA-2), or zinc transporter 8 (ZnT8). Prolonged exposure to autoantibodies may be related to T cell exhaustion known to occur in chronic infections or autoimmune disorders. It was hypothesized that autoantibody exposure may affect HLA-DQ expression on peripheral blood cells and thereby contribute to T cell exhaustion thought to be associated with the pathogenesis of type 1 diabetes. The aim of this study was to determine whether autoantibody exposure as an expression of autoimmunity burden was related to peripheral blood cell HLA-DQ cell surface expression in either 1) a cross-sectional analysis or 2) cumulative as area under the trajectory of autoantibodies during long term follow-up in the Diabetes Prediction in Skåne (DiPiS) study. Children (n = 67), aged 10–15 years were analyzed for complete blood count, HLA-DQ cell surface median fluorescence intensity (MFI), autoantibody frequency, and HLA genotypes by Next Generation Sequencing. Decreased HLA-DQ cell surface MFI with an increasing number of autoantibodies was observed in CD16⁺, CD14⁺CD16⁻, CD4⁺ and CD8⁺ cells but not in CD19⁺ cells and neutrophils. HLA-DQ cell surface MFI was associated with HLA-DQ2/8 in CD4⁺ T cells, marginally in CD14⁺CD16⁻ monocytes and CD8⁺ T cells. These associations appeared to be related to autoimmunity burden. The results suggest that HLA-DQ cell surface expression was related to HLA and autoimmunity burden.

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PBMC HLA-DQ surface expression in beta cell autoimmunity is poorly understood.

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Children, 10–15 years of age without or with beta cell autoantibodies were analyzed.

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HLA-DQ cell surface expression decreased with increasing number of autoantibodies.

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HLA-DQ cell surface expression was related to HLA and autoimmunity burden.

What do parents believe are the causes of their Type 1 diabetic child's condition?

Purpose

This paper aims to investigate parents' beliefs about the causes of their child's Type 1 diabetes to understand if this affects the way diagnosis is processed and if this impacts on sibling parenting.

Design/methodology/approach

Online, semi-structured qualitative interviews with nine parents of children with Type 1 diabetes who have at least one non-diabetic child. The results were analysed using interpretative phenomenological analysis (IPA).

Findings

Two interlinked themes were identified: “What ifs”: parents postulated underlying genetic reasons for their child's diabetes and had working theories about the triggers of diabetes that included stress, infection, vaccination or a virus. Developing a personal aetiology of their child's condition allowed some a feeling of control, while others focused on practical ways to manage diabetes. “Having something to blame”: narratives dwelt on the relationship between beliefs about causes and self-blame. Some believed that acting on an identified trigger reduced personal guilt.

Research limitations/implications

Although internet access is widespread in the UK, a limitation of this research is that it excluded those without internet access.

Practical implications

The findings of this research may provide greater depth and a more holistic perspective to the health promoter to better support parents of Type 1 diabetics.

Social implications

The analysis of illness narratives that this research provides may offer a greater understanding of the social context in which health and illness develop. This research found some examples of parental confidence about the causes and triggers of their child's diabetes being positively associated with a sense of control. This might indicate the value of a more comprehensive larger-scale study to establish whether parents who are supported to develop a personalised conception of the aetiology of their child's diabetes develop a greater sense of coherence and well-being regarding their child's condition.

Originality/value

There is very limited literature focusing on the beliefs of sufferers and their families about Type 1 diabetes causality. Of that which does exist, some research is heterogenous in its sampling of Types 1 and 2 diabetes sufferers. This study offers a rare, focused insight into the beliefs of parents about the background causes and more proximal triggers of their child's Type 1 diabetes.

Serum 25-hydroxyvitamin D concentration in childhood and risk of islet autoimmunity and type 1 diabetes: the TRIGR nested case-control ancillary study

AIMS/HYPOTHESIS

Our aim was to study the association between serum 25-hydroxyvitamin D (25OHD) concentration and islet autoimmunity and type 1 diabetes in children with an increased genetic risk of type 1 diabetes.

METHODS

Serum samples for 25OHD measurements were obtained in the Trial to Reduce IDDM in the Genetically at Risk (TRIGR) ancillary study (Divia) from children in 15 countries. Case children (n = 244) were defined as having positivity for at least two out of four diabetes-associated autoantibodies measured at any one sample. For each case child, two control children were selected matched for country and date of birth (±1 year) (n = 488). Of the case children, 144 developed type 1 diabetes. Serum 25OHD was measured repeatedly in infancy and childhood and was compared according to age at the first seroconversion (at 6, 12 and 18 months prior to and at seroconversion) and calendar age (0, 6, 12 and 18 months).

RESULTS

In children with islet autoimmunity, mean serum 25OHD concentration was lower 18 months prior to the age of first seroconversion of the case children compared with the control children (57.7 vs 64.8 nmol/l, p = 0.007). In children with type 1 diabetes (n = 144), mean serum 25OHD concentration was lower 18 months prior to the age of the first seroconversion (58.0 vs 65.0 nmol/l, p = 0.018) and at the calendar age of 12 months (70.1 vs 75.9 nmol/l, p = 0.031) than in their control counterparts. Analyses were adjusted for month of sample collection, human leucocyte antigen genotype, maternal type 1 diabetes and sex.

CONCLUSIONS/INTERPRETATION

The results suggest that early postnatal vitamin D may confer protection against the development of type 1 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00179777.

The rs11755527 polymorphism in the BACH2 gene and type 1 diabetes mellitus: case control study in a Brazilian population

Objective Type 1 diabetes mellitus (T1DM) is an autoimmune disorder caused by a complex interaction between environmental and genetic risk factors. BTB domain and CNC homolog 2 (BACH2) gene encodes a transcription factor that acts on the differentiation and formation of B and T lymphocytes. BACH2 is also involved in the suppression of apoptosis and inflammation in pancreatic beta-cells, indicating a role for it in the development of T1DM. Therefore, the aim of this study was to evaluate the association of the BACH2 rs11755527 single nucleotide polymorphism (SNP) with T1DM. Subjects and methods This case-control study comprised 475 patients with T1DM and 598 nondiabetic individuals. The BACH2 rs11755527 (C/G) SNP was genotyped using real-time PCR with TaqMan MGB probes. Results Genotype distributions of rs11755527 SNP were in accordance with frequencies predicted by the Hardy-Weinberg equilibrium in case and control groups and were similar between groups (P = 0.729). The minor allele frequency was 43.6% in cases and 42.5% in controls (P = 0.604). Moreover, the G allele frequency did not differ between groups when considering different inheritance models and adjusting for age, gender, body mass index, and HLA DR/DQ genotypes of high-risk for T1DM. Although, well-known high-risk T1DM HLA DR/DQ genotypes were associated with T1DM in our population [OR= 7.42 (95% CI 3.34 - 17.0)], this association was not influenced by the rs11755527 SNP. Conclusion The BACH2 rs11755527 SNP seems not to be associated with T1DM in a Brazilian population.

The relationship between long-term exposure to PM2.5 and fasting plasma glucose levels in Chinese children and adolescents aged 6-17 years: A national cross-sectional study

BACKGROUND

Previous studies investigating the association between PM_2.5 exposure and fasting plasma glucose levels (FPGLs) are mostly limited to short- and mid-term PM_2.5 exposure and lack adjustments for key confounders in adult research.

OBJECTIVES

Exploring the relationship between seven years long-term PM_2.5 exposure and FPGLs in Chinese children and adolescents aged 6-17 years.

METHODS

Between September 2013 and December 2013, 16,489 participants aged 6-17 years were recruited using a four-staged, stratified, cluster sampling strategy from 7 provinces, autonomous regions and municipalities of mainland China. A generalized linear mixed model (GLMM) was used to estimate the relationship between annual PM_2.5 exposure (2007-2013) and FPGLs stratified by sex and one-year age increments. Sociodemographic characteristics, living with both parents, early-life factors, behaviours, and infection symptoms were gradually adjusted from the crude model to regression model 6, and BMI was adjusted for in model 7.

RESULTS

The annual concentration of PM_2.5 was 56.23 (±12.99) μg/m³. The mean FPGLs in the 8551 boys (4.75 mmol/L ± 0.52) was significantly higher than that in the 8194 girls (4.63 mmol/L ± 0.48) (P < 0.0001). In model 6, for every 10 μg/m3 increase in PM_2.5 exposure, the FPGLs in boys and girls increased by 0.048 (95% CIs 0.031 to 0.065) mmol/L (P < 0.0001) and 0.054 (95% CIs 0.039 to 0.069) mmol/L (P < 0.0001), respectively. The FPGLs were significantly positively associated with long-term PM_2.5 exposure at the ages of 12, 15 and 16 years in both the boys and girls and exhibited age differences in model 7. The prevalence of impaired fasting plasma glucose (IFP) and diabetes decreased by 0.8% when the exposure concentration of PM_2.5 was reduced by 10 μg/m³ in model 6, which assessed the negative effects of PM_2.5 exposure and revealed that 1,298,920 children and adolescents could have been protected from IFP and diabetes in 2013 in China.

CONCLUSIONS

Long-term PM_2.5 exposure may be an independent risk factor of elevated FPGLs. The adverse effect of PM_2.5 exposure on FPGLs in children and adolescents could appear after 10 years of cumulative exposure. The precise intervention time was revealed as approximately 12 and 11 years in boys and girls, respectively. There are great public health implications associated with early prevention strategies for the eradication of the negative effects of long-term exposure to PM_2.5 on FPGLs.

Biochemical, serological, and genetic aspects related to gene HLA-DQB1 and its association with type 1 diabetes mellitus (T1DM)

Background

Type 1 Diabetes Mellitus (T1DM) is the autoimmune disorder of destruction of β cells of pancreas, creating insulin deficiency condition, which leads to hyperglycemia, polyuria, polydipsia, ketoacidosis, and other metabolic disorder especially in children. Different genetic aspects and environmental factors are involved in pathophysiology of the disease. About 20 genes are associated with this disease in which the most common is the different combination of haplotype DRB1‐DQA1‐DQB1 present at HLA gene. At HLA‐DQB1, there are some SNPs which are associated with T1DM. In T1DM, there are number of biochemical, serological parameters which show some abnormalities leading to some complications.

Methods

Samples were subjected to all biochemical and serological techniques to get the measurement of concentration of glucose, lipid profile (cholesterol, triglycerides, and HDL and LDL cholesterol), urea, creatinine, albumin, insulin, anti‐insulin antibodies, C‐peptides, and leptin. All these values were compared with controls values and statistical analysis was also done on these values. At molecular level, two primers set which were allele specific at HLA‐DQB1, were used to amplify the SNPs, homozygous and heterozygous conditions were stated.

Results

PCR results for the studied population showed that most of samples have heterozygous condition for these SNPs of this allele specific region on HLA‐DQB1. Very few of them have homozygous state for it. Even in the control sample have the same conditions.

Conclusion

In Pakistan, there is dire need of studies about SNPs and haplotypes related to HLA‐DQB1 which show association with T1DM.

Time for a paradigm shift in treating type 1 diabetes mellitus: coupling inflammation to islet regeneration

Type 1 diabetes mellitus (T1DM) is an autoimmune disease that targets the destruction of islet beta-cells resulting in insulin deficiency, hyperglycemia and death if untreated. Despite advances in medical devices and longer-acting insulin, there is still no robust therapy to substitute and protect beta-cells that are lost in T1DM. Attempts to refrain from the autoimmune attack have failed to achieve glycemic control in patients highlighting the necessity for a paradigm shift in T1DM treatment. Paradoxically, beta-cells are present in T1DM patients indicating a disturbed equilibrium between the immune attack and beta-cell regeneration reminiscent of unresolved wound healing that under normal circumstances progression towards an anti-inflammatory milieu promotes regeneration. Thus, the ultimate T1DM therapy should concomitantly restore immune self-tolerance and replenish the beta-cell mass similar to wound healing. Recently the agonistic activation of the nuclear receptor LRH-1/NR5A2 was shown to induce immune self-tolerance, increase beta-cell survival and promote regeneration through a mechanism of alpha-to-beta cell phenotypic switch. This trans-regeneration process appears to be facilitated by a pancreatic anti-inflammatory environment induced by LRH-1/NR5A2 activation. Herein, we review the literature on the role of LRH1/NR5A2 in immunity and islet physiology and propose that a cross-talk between these cellular compartments is mandatory to achieve therapeutic benefits.

Autoantigen Treatment in Type 1 Diabetes: Unsolved Questions on How to Select Autoantigen and Administration Route

Autoantigen treatment has been tried for the prevention of type 1 diabetes (T1D) and to preserve residual beta-cell function in patients with a recent onset of the disease. In experimental animal models, efficacy was good, but was insufficient in human subjects. Besides the possible minor efficacy of peroral insulin in high-risk individuals to prevent T1D, autoantigen prevention trials have failed. Other studies on autoantigen prevention and intervention at diagnosis are ongoing. One problem is to select autoantigen/s; others are dose and route. Oral administration may be improved by using different vehicles. Proinsulin peptide therapy in patients with T1D has shown possible minor efficacy. In patients with newly diagnosed T1D, subcutaneous injection of glutamic acid decarboxylase (GAD) bound to alum hydroxide (GAD-alum) can likely preserve beta-cell function, but the therapeutic effect needs to be improved. Intra-lymphatic administration may be a better alternative than subcutaneous administration, and combination therapy might improve efficacy. This review elucidates some actual problems of autoantigen therapy in the prevention and/or early intervention of type 1 diabetes.

Anti-diabetic potential of plant alkaloids: Revisiting current findings and future perspectives

Diabetes mellitus (DM) is a chronic metabolic disease which causes millions of death all over the world each year, and its incidence is on increase. The most prevalent form, type 2 DM, is characterized by insulin resistance and β-cell dysfunction, whereas type 1 DM is due to insulin deficiency as a result of β-cell destruction. Various classes of synthetic drugs have been developed to regulate glucose homeostasis and combat the development of late-diabetic complications. However, several of these chemical agents are either sub-optimal in their effect and/or may have side effects. Biologically, alkaloids unveiled a wide range of therapeutic effects including anti-diabetic properties. The chemical backbones of these compounds have the potential to interact with a wide range of proteins involved in glucose homeostasis, and thus they have received increasing attention as reliable candidates for drug development. This review sets out to investigate the anti-diabetic potential of plant alkaloids (PAs), and therefore, scientific databases were comprehensively screened to highlight the biological activity of 78 PAs with a considerable anti-diabetic profile. There are not enough clinical data available for these phytochemicals to follow their fingerprint in human, but current studies generally recommending PAs as potent α-glucosidase inhibitors. Except for some classes of monoterpene alkaloids, other compounds showed similar features as well as the presently available anti-diabetic drugs such as amino sugars and other relevant drugs. Moreover, the evidence suggests that PAs have the potential to be used as alternative additives for the treatment of DM, however, further in vitro and in vivo studies are needed to validate these findings.

Distinct two different ages associated with clinical profiles of acute onset type 1 diabetes in Chinese patients

BACKGROUND

There are abundant variations in the phenotypes and genetics of type 1 diabetes (T1D) patients across different races. This study aimed to assess differences between juvenile acute onset (JAO) and adult acute onset in Chinese T1D patients.

METHODS

Seven hundred and fifty-one acute onset T1D patients were divided into two groups by the patient onset age as follows: the juvenile acute onset group (≤20 years, JAO group) and the adult acute onset group (>20 years, AAO group). Clinical characteristics, islet autoantibodies, and HLA class II haplotypes and genotypes were compared between these two groups.

RESULTS

In comparison with AAO patients, JAO patients had significantly lower relative weights and lower triglyceride levels (P < .001, P < .01, respectively) but higher frequency of ketoacidosis (P < .001), higher daily insulin dosage (P_c  < .001), higher HbA1_c (P_c  < .05), and higher HDL-cholesterol levels (P_c  < .01). The JAO group showed a higher prevalence of IA-2A, ZnT8A, and multiple autoantibodies than that in the AAO group (P < .001, P < .01, P < .001, respectively). Haplotypes for DRB1*0301-DQA1*03-DQB1*0201, DR3, DR4, DR9, and DR3/DR9 genotypes are highly associated with JAO susceptibility, whereas only DR3 and DR9 genotypes confer risk for AAO. In the JAO group but not the AAO group, DR3 is related to ZnT8A, and DR3/DR9 is related to IA-2A and multiple autoantibodies.

CONCLUSIONS

These observations suggest that JAO patients markedly differ from AAO patients in their clinical manifestations and genetics in the Chinese T1D population. Notably, the DR3/DR9 genotype can facilitate the appearance of IA-2A or multiple autoantibodies in JAO patients.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Investigation of gut microbiome changes in type 1 diabetic mellitus rats based on high-throughput sequencing

The incidence of type 1 diabetes mellitus (T1DM) is increasing year by year, gut microbiota is considered to be closely related to the occurrence and development of T1DM in recent years. In this study, Sprague Dawley (SD) rats were intraperitoneally injected with 75mg/kg streptozotocin to establish T1DM model, fecal samples were collected and DNA were extracted, 16S rRNA microbial gene clone library were constructed, and lastly high-throughput sequencing and bioinformatics analysis were performed. The results showed that the abundances of pathogenic bacteria such as Ruminococcaceae, Shigella, Enterococcus, Streptococcus, Rothia and Alistipes associated with infection and inflammation in T1DM rats were up-regulated, while the abundances of beneficial bacteria such as Lactobacillus, Faecalitalea, Butyricicoccus and Allobaculum were reduced. Among them, Butyricicoccus and Allobaculum protect intestinal barrier function by producing short-chain fatty acids. This study suggests that intestinal inflammation and reduction of short chain fatty acids (SCFAs) caused by the imbalance of gut microbiota are crucial to the pathogenesis of T1DM.

Association between Aldose Reductase Gene C(-106)T Polymorphism and Diabetic Retinopathy: A Systematic Review and Meta-Analysis

Controversial results regarding the associations between aldose reductase (AR) genetic polymorphisms and diabetic retinopathy (DR) have been reported for many years. The present meta-analysis was performed to clarify the effects of the AR gene C(-106)T polymorphism on DR risk. The PubMed, Web of Sciences, Cochrane library, EMBASE, Chinese National Knowledge Infrastructure, and Wan Fang databases were extensively searched in Chinese to select relevant studies with an updated date of April 25, 2018. The Newcastle-Ottawa Scale (NOS) was applied to assess quality. The random-effects model was applied to calculate the pooled OR and 95% CI. This meta-analysis identified 23 studies with an average score of 7.52 for NOS analysis, including 4,313 DR cases and 5,128 diabetes mellitus (DM) control cases. In the overall analysis, a significant association between the AR gene C(-106)T polymorphism and DR susceptibility was found. In subgroups stratified by DM type and ethnicity, significantly increased risks for DR were found in DM type 1, East Asian populations, and Middle Eastern populations. Compared with DR control cases, the following associations were found: T vs. C: OR 0.91, 95% CI 0.85-0.97, I2 = 72.9%; CT + TT vs. CC: OR 0.75, 95% CI 0.68-0.81, I2 = 86.7%; and CT vs. CC: OR 0.86, 95% CI 0.78-0.94, I2 = 70.5%. The results of this meta-analysis showed a significant association between the AR gene C(-106)T polymorphism and susceptibility to DR in DM patients. DM patients with allele T and CT+TT genotype of the AR gene may have a lower risk of DR.

PPARs and the Development of Type 1 Diabetes

Peroxisome proliferator-activated receptors (PPARs) are a family of transcription factors with a key role in glucose and lipid metabolism. PPARs are expressed in many cell types including pancreatic beta cells and immune cells, where they regulate insulin secretion and T cell differentiation, respectively. Moreover, various PPAR agonists prevent diabetes in the non-obese diabetic (NOD) mouse model of type 1 diabetes. PPARs are thus of interest in type 1 diabetes (T1D) as they represent a novel approach targeting both the pancreas and the immune system. In this review, we examine the role of PPARs in immune responses and beta cell biology and their potential as targets for treatment of T1D.

Water Soluble Vitamins and their Role in Diabetes and its Complications

BACKGROUND

Diabetes is a metabolic disorder associated with abnormally high levels of glucose in the blood due to inadequate production of insulin or inadequate sensitivity of cells to the action of insulin. Diabetes has become an increasing challenge in the world. The predicted diabetic population according to the World Health Organization is 8.7% between the age group 20-70 years. There are many complications linked to prolonged high blood glucose levels, such as microvascular complications and macrovascular complications. Vitamins play an important role in glucose metabolism and the potential utility of supplementation is relevant for the prevention and/or management of diabetes mellitus and its complications.

METHODS

Literature search was performed using various dataset like PUBMED, EBSCO, ProQuest, Scopus and selected websites like the National Institute of Health and the World Health Organization.

RESULT

Water-soluble vitamins have been thoroughly studied for their activity in diabetes and diabetic complications.

CONCLUSION

Water-soluble vitamins like B1, B3, B6, B7, B9 and B12 have notable effects in diabetes mellitus and its related complications like nephropathy, neuropathy, retinopathy and cardiomyopathy.

Polymorphisms of the NLRC4 Gene are Associated with the Onset Age, Positive Rate of GADA and 2-h Postprandial C-Peptide in Patients with Type 1 Diabetes

PURPOSE

The purpose of this study was to clarify the association between the NLRC4 gene and the susceptibility and clinical characteristics of type 1 diabetes (T1D) in a Chinese Han population.

PATIENTS AND METHODS

A case-control study was performed in a Chinese Han population including 510 classical T1D patients and 531 healthy controls. rs212704 and rs385076 of the NLRC4 gene were genotyped by MassARRAY. The frequency distributions of alleles and genotypes of polymorphisms in the NLRC4 gene were compared by logistic regression and the chi-square test. The relationships between the polymorphisms of the NLRC4 gene and various clinical characteristics were analyzed by Kruskal-Wallis one-way ANOVA. The statistical power was calculated by Quanto software.

RESULTS

1) rs385076 of the NLRC4 gene was significantly correlated with the onset age of T1D patients and the positive rate of GADA. The relationship between rs212704 and 2-h postprandial C-peptide was statistically significant. 2) There was no significant difference in the frequency distributions of the genotypes and alleles of rs212704 and rs385076 between T1D patients and controls. 3) rs212704 and rs385076 were not correlated with T1D susceptibility under different genetic models.

CONCLUSION

rs212704 was associated with 2-h postprandial C-peptide, while rs385076 of the NLRC4 gene was associated with the onset age and positive rate of GADA in patients with T1D.

Prediction and Prevention of Type 1 Diabetes

Type 1 Diabetes (T1D) is one of the most common chronic autoimmune diseases in children. The disease is characterized by the destruction of beta cells, leading to hyperglycemia, and to a lifelong insulin-dependent state. Although several studies in the last decades have added relevant insights, the complex pathogenesis of the disease is not yet completely understood. Recent studies have been focused on several factors, including family history and genetic predisposition (HLA and non-HLA genes) as well as environmental and metabolic biomarkers, with the aim of predicting the development and progression of T1D. Once a child becomes symptomatic, beta cell mass has already reached a critical threshold (usually a residual of 20-30% of normal amounts), thus representing only the very late phase of the disease. In particular, this final stage follows two preceding asymptomatic stages, which have been precisely identified. In view of the long natural history and complex pathogenesis of the disease, many strategies may be proposed for primary, secondary, and tertiary prevention. Strategies of primary prevention aim to prevent the onset of autoimmunity against beta cells in asymptomatic individuals at high risk for T1D. In addition, the availability of novel humoral and metabolic biomarkers that are able to characterize subjects at high risk of progression, have stimulated several studies on secondary and tertiary prevention, aimed to preserve residual beta cell destruction and/or to prolong the remission phase after the onset of T1D. This review focuses on the major current knowledge on prediction and prevention of T1D in children.

Type 1 diabetes linked PTPN22 gene polymorphism is associated with the frequency of circulating regulatory T cells

Dysfunction of FOXP3-positive regulatory T cells (Tregs) likely plays a major role in the pathogenesis of multiple autoimmune diseases including type 1 diabetes (T1D). Whether genetic polymorphisms associated with the risk of autoimmune diseases affect Treg frequency or function is currently unclear. Here, we analysed the effect of T1D-associated major HLA class II haplotypes and seven single nucleotide polymorphisms in six non-HLA genes [INS (rs689), PTPN22 (rs2476601), IL2RA (rs12722495 and rs2104286), PTPN2 (rs45450798), CTLA4 (rs3087243), and ERBB3 (rs2292239)] on peripheral blood Treg frequencies. These were determined by flow cytometry in 65 subjects who had progressed to T1D, 86 islet autoantibody-positive at-risk subjects, and 215 islet autoantibody-negative healthy controls. The PTPN22 rs2476601 risk allele A was associated with an increase in total (p = 6 × 10^-6 ) and naïve (p = 4 × 10^-5 ) CD4+CD25+CD127lowFOXP3+ Treg frequencies. These findings were validated in a separate cohort comprising ten trios of healthy islet autoantibody-negative children carrying each of the three PTPN22 rs2476601 genotypes AA, AG, and GG (p = 0.005 for total and p = 0.03 for naïve Tregs, respectively). In conclusion, our analysis implicates the autoimmune PTPN22 rs2476601 risk allele A in controlling the frequency of Tregs in human peripheral blood.

The associations between three genome-wide risk variants for serum C-peptide of T1D and autoantibody-positive T1D risk, and clinical characteristics in Chinese population

AIMS

Recent meta-genome-wide association studies identified several genetic variants associated with beta-cell function in type 1 diabetes (T1D). The aim of this study was to investigate the associations between these variants and T1D risk, C-peptide levels, islet-specific autoantibodies, and lipid levels in Chinese Han population.

METHODS

A total of 1005 unrelated autoantibody-positive T1D cases and 1417 healthy controls were included, which were genotyped for rs559047, rs9260151, and rs3135002. T1D individuals were measured for both C-peptide and lipid levels. Logistic regression models were used to examine these associations.

RESULTS

We found that rs3135002 A allele showed a genome-wide significant association with T1D risk (OR = 0.22, 95% CI = 0.17-0.30; P = 7.49 × 10^-27), and significant heterogeneity of effect size was observed between early-onset and later-onset T1D subgroups (I² = 80% and P = 0.026). Rs559047 had a nominal association with fasting C-peptide levels in newly diagnosed T1D individuals (P = 0.036). Moreover, rs3135002 A allele was significantly associated with GADA positivity (OR = 0.52, 95% CI = 0.30-0.91, P = 0.02). In addition, nominal correlations were observed with HDL levels for rs559047 (P = 0.042), while LDL levels for rs9260151 (P = 0.032) in T1D individuals.

CONCLUSIONS

Our results indicate that there are both similarities and differences for the associations of genetic variants among T1D development, progression, and related autoimmunity, metabolic traits.

Gastrointestinal Microbiota and Type 1 Diabetes Mellitus: The State of Art

The incidence of autoimmune type 1 diabetes (T1DM) is increasing worldwide and disease onset tends to occur at a younger age. Unfortunately, clinical trials aiming to detect predictive factors of disease, in individuals with a high risk of T1DM, reported negative results. Hence, actually there are no tools or strategies to prevent T1DM onset. The importance of the gut microbiome in autoimmune diseases is increasingly recognized and recent data suggest that intestinal dysbiosis has a pathogenic role in T1DM by affecting both intestinal immunostasis and the permeability of the gut barrier. An improved understanding of the mechanisms whereby dysbiosis in the gut favors T1DM development may help develop new intervention strategies to reduce both the incidence and burden of T1DM. This review summarizes available data on the associations between gut microbiota and T1DM in both experimental animals and humans and discusses future perspectives in this novel and exciting area of research.