Epigenetic regulation of Toll-like receptors and its roles in type 1 diabetes

Epigenetic regulation of B cells and its role in autoimmune pathogenesis

B cells play a pivotal role in the pathogenesis of autoimmune diseases. Although previous studies have shown many genetic polymorphisms associated with B-cell activation in patients with various autoimmune disorders, progress in epigenetic research has revealed new mechanisms leading to B-cell hyperactivation. Epigenetic mechanisms, including those involving histone modifications, DNA methylation, and noncoding RNAs, regulate B-cell responses, and their dysregulation can contribute to the pathogenesis of autoimmune diseases. Patients with autoimmune diseases show epigenetic alterations that lead to the initiation and perpetuation of autoimmune inflammation. Moreover, many clinical and animal model studies have shown the promising potential of epigenetic therapies for patients. In this review, we present an up-to-date overview of epigenetic mechanisms with a focus on their roles in regulating functional B-cell subsets. Furthermore, we discuss epigenetic dysregulation in B cells and highlight its contribution to the development of autoimmune diseases. Based on clinical and preclinical evidence, we discuss novel epigenetic biomarkers and therapies for patients with autoimmune disorders.

Akkermansia muciniphila and Gut Immune System: A Good Friendship That Attenuates Inflammatory Bowel Disease, Obesity, and Diabetes

Akkermansia muciniphila is a Gram-negative anaerobic mucus-layer-degrading bacterium that colonizes the intestinal mucosa of humans and rodents. Metagenomic data have shown an inverse correlation between the abundance of A. muciniphila and diseases such as inflammatory bowel disease (IBD), obesity, and diabetes. Thus, in recent decades, the potential of this bacterium as an immunomodulatory probiotic for autoimmune and chronic inflammatory diseases has been explored in experimental models. Corroborating these human correlation data, it has been reported that A. muciniphila slows down the development and progression of diabetes, obesity, and IBD in mice. Consequently, clinical studies with obese and diabetic patients are being performed, and the preliminary results are very promising. Therefore, this mini review highlights the main findings regarding the beneficial roles of A. muciniphila and its action mechanisms in autoimmune and chronic inflammatory diseases.

Toll-Like Receptor 4 in Pain: Bridging Molecules-to-Cells-to-Systems

Pain impacts the lives of billions of people around the world - both directly and indirectly. It is complex and transcends beyond an unpleasant sensory experience to encompass emotional experiences. To date, there are no successful treatments for sufferers of chronic pain. Although opioids do not provide any benefit to chronic pain sufferers, they are still prescribed, often resulting in more complications such as hyperalgesia and dependence. In order to develop effective and safe medications to manage, and perhaps even treat pain, it is important to evaluate novel contributors to pain pathologies. As such, in this chapter we review the role of Toll-like receptor 4, a receptor of the innate immune system, that continues to gain substantial attention in the field of pain research. Positioned in the nexus of the neuro and immune systems, TLR4 may provide one of the missing pieces in understanding the complexities of pain. Here we consider how TLR4 enables a mechanistical understanding of pain as a multidimensional biopsychosocial state from molecules to cells to systems and back again.

rs3806265 and rs4612666 of the NLRP3 Gene Are Associated With the Titer of Glutamic Acid Decarboxylase Antibody in Type 1 Diabetes

BACKGROUND AND AIMS

The NLRP3 gene is reportedly associated with several autoimmune diseases. However, in the Chinese Han population, whether NLRP3 polymorphisms are associated with type 1 diabetes (T1D) is unclear. Therefore, this study examined the associations of rs3806265 and rs4612666 of the NLRP3 gene with T1D susceptibility and the clinical characteristics of Chinese Han T1D patients.

METHODS

In total, 510 classic T1D patients and 531 healthy controls from the Chinese Han population were recruited for a case-control study. rs3806265 and rs4612666 of the NLRP3 gene were genotyped by MassARRAY. Logistic regression analysis and the chi-square test were used to compare the distributions of the alleles and genotypes of rs3806265 and rs4612666. The relationships between rs3806265 and rs4612666 and the clinical characteristics of T1D patients were analyzed by Kruskal-Wallis one-way ANOVA. Student's t test was used to analyze normally distributed data. Bonferroni correction was used for multiple comparisons.

RESULTS

1) rs3806265 was associated with glutamic acid decarboxylase antibody (GADA) titers (P = 0.02), and patients with the CC genotype had higher GADA titers than patients with the TT genotype. 2) rs4612666 was also associated with GADA titers (P=0.041). Compared with patients with the CC genotype, patients with the TT genotype had higher GADA titers. 3) rs3806265 and rs4612666 of the NLRP3 gene were not significantly associated with T1D susceptibility under different genetic models.

CONCLUSION

rs3806265 and rs4612666 of the NLRP3 gene were significantly associated with GADA titers in Chinese Han T1D patients.

Innate immunity in latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is an autoimmune disease that shares some genetic, immunological and clinical features with both type 1 diabetes and type 2 diabetes. Immune cells including CD4⁺ T cells, CD8⁺ T cells, B cells, macrophages and dendritic cells (DCs) have been detected in the pancreas of patients with LADA and a rat model of LADA. Therefore, similar to type 1 diabetes, the pathogenesis of LADA may be caused by interactions between islet β-cells and innate and adaptive immune cells. However, the role of the immunity in the initiation and progression of LADA remains largely unknown. In this review, we have summarized the potential roles of innate immunity and immune-modulators in LADA development. Furthermore, we have examined the evidence and discussed potential innate immunological reasons for the slower development of LADA compared with type 1 diabetes. More in-depth mechanistic studies are needed to fully elucidate the roles of innate immune-associated genes, molecules and cells in their contributions to LADA pathogenesis. Undertaking these studies will greatly enhance the development of new strategies and optimization of current strategies for the diagnosis and treatment of the disease.

The Positivity Rate of IA-2A and ZnT8A in the Chinese Han Population With Type 1 Diabetes Mellitus: Association With rs1143627 and rs1143643 Polymorphisms in the IL1B Gene

Objective: To investigate the association between susceptibility to type 1 diabetes mellitus (T1DM) and polymorphisms (rs1143627 and rs1143643) in the interleukin 1 beta (IL1B) gene in the Chinese Han population. Methods: The Meso Scale Discovery (MSD) method was used to detect the concentration of IL-1β in 24 T1DM patients and 27 healthy controls. MassARRAY was used to analyze the polymorphisms in the IL1B gene in 510 patients with classic T1DM and 531 healthy controls. The general data of the T1DM patients and healthy controls were compared by the chi-square test and Mann-Whitney U test. The chi-square test and logistic regression were used to analyze the frequency distributions of alleles and genotypes of polymorphisms in the IL1B gene. The Kruskal-Wallis H test and chi-square test were used for the genotype-phenotype analysis of rs1143627 and rs1143643 in the IL1B gene. Results: ① The concentration of IL-1β in T1DM patients was significantly higher than that in healthy controls. ② rs1143627 and rs1143643 in the IL1B gene were significantly correlated with the positivity rates for IA-2A and ZnT8A; genotype GG at rs1143627 and genotype CC at rs1143643 in the case group showed lower positivity rates for IA-2A and ZnT8A. ③ There was no significant difference in the genotypes or allele frequencies at rs1143627 (GG/GA/AA) or rs1143643 (CC/CT/TT) between the case group and control group (p > 0.05). ④ rs1143627 and rs1143643 were not found to be linked to T1DM susceptibility under different genetic models. Conclusion: rs1143627 and rs1143643 in the IL1B gene correlate with the positivity rate of IA-2A and ZnT8A in Chinese Han individuals with T1DM.

Role of Innate Immunity and Oxidative Stress in the Development of Type 1 Diabetes Mellitus. Peroxiredoxin 6 as a New Anti-Diabetic Agent

The review discusses information on the development of type 1 diabetes mellitus (T1D) as a systemic autoimmune and inflammatory disease. Focus of the review is on the role of innate immune system, including activation of some signaling cascades, cytokine response, and activity of the Toll-like receptors in the development of T1D. Dysfunction of innate immunity is the cause of the attack of pancreatic beta cells by the host T-lymphocytes, which leads to the death of pancreatic beta cells that produce insulin. Lack of insulin causes hyperglycemia and the need for lifelong injections of insulin in patients with T1D, which, nevertheless, does not exclude damage to many organs and tissues, given particular vulnerability of the blood vessels under conditions of hyperglycemia. The review discusses the role of oxidative stress as a factor that plays a major role in damage of vascular system and pancreatic tissue during the development of T1D. Considering high sensitivity of pancreatic beta cells to the action of reactive oxygen species (ROS), the possibility of using antioxidants for reducing the level of pathological consequences in the course of T1D development is discussed. New information on anti-diabetic activity of the exogenous antioxidant enzyme peroxiredoxin 6, which is capable of penetrating cells, activating insulin production in beta cells, reducing ROS levels, as well as decreasing activation of some signaling cascades, production of pro-inflammatory cytokines, and expression of Toll-like receptors in beta cells and in immune cells during T1D development is discussed.

Insights Into the Role of DNA Methylation in Immune Cell Development and Autoimmune Disease

To date, nearly 100 autoimmune diseases have been an area of focus, and these diseases bring health challenges to approximately 5% of the population worldwide. As a type of disease caused by tolerance breakdown, both environmental and genetic risk factors contribute to autoimmune disease development. However, in most cases, there are still gaps in our understanding of disease pathogenesis, diagnosis, and treatment. Therefore, more detailed knowledge of disease pathogenesis and potential therapies is indispensable. DNA methylation, which does not affect the DNA sequence, is one of the key epigenetic silencing mechanisms and has been indicated to play a key role in gene expression regulation and to participate in the development of certain autoimmune diseases. Potential epigenetic regulation via DNA methylation has garnered more attention as a disease biomarker in recent years. In this review, we clarify the basic function and distribution of DNA methylation, evaluate its effects on gene expression and discuss related key enzymes. In addition, we summarize recent aberrant DNA methylation modifications identified in the most important cell types related to several autoimmune diseases and then provide potential directions for better diagnosing and monitoring disease progression driven by epigenetic control, which may broaden our understanding and contribute to further epigenetic research in autoimmune diseases.

Effect of cold exposure and capsaicin on the expression of histone acetylation and Toll-like receptors in 1,2-dimethylhydrazine-induced colon carcinogenesis

Previous studies have indicated that capsaicin-rich diet and cold weather have shown strong association with tumor incidence. Thus, we investigated the effects of capsaicin and cold exposure in 1,2-dimethylhydrazine (DMH)-induced colorectal cancer as well as the mechanisms underlying capsaicin and cold-induced CRC. Rats were randomly divided into four groups and received cold still water and capsaicin via intragastric gavage until the end of the experiment. The rat's body weight, thymus weight, and food intakes were assessed. Global levels of histone H3K9, H3K18, H3K27, and H4K16 acetylation and histone deacetylase (HDACs) in colon mucosa were assessed by western blot. Expression levels of Toll-like receptors 2 (TLR2) and Toll-like receptors 4 (TLR4) were measured by western blot and reverse-transcriptase quantitative polymerase chain reaction (qPCR). We found that cold and low-dose capsaicin increased tumor numbers and multiplicity, although there were no differences in tumor incidence. Additionally, rat exposure to cold water and capsaicin display further higher levels of histone H3 lysine 9 (H3K9AC), histone H3 lysine 18 (H3K18AC), histone H3 lysine 27 (H3K27AC), and HDACs compared with the DMH and normal rats. In contrast, a considerable decrease of histone H4 lysine 16 (H4K16AC) was detected in the colon mucosa. Cold and low-dose capsaicin exposure groups were also increased TLR2 and TLR4 protein levels and mRNA levels. These results suggest that chronic cold exposure and capsaicin at a low-dose intervention exacerbate ectopic expression of global histone acetylation and TLR level, which are crucial mechanisms responsible for the progression of colorectal cancer in rats.

RAGE-mediated functional DNA methylated modification contributes to cigarette smoke-induced airway inflammation in mice

Our previous study indicated knockout of receptor for advanced glycation end-products (RAGE) significantly attenuated cigarette smoke (CS)-induced airway inflammation in mice. In the present study, we aim to further detect the mediatory effects of RAGE in DNA methylated modification in CS-induced airway inflammation. Lung tissues from the CS-exposed mouse model of airway inflammation were collected for profiling of DNA methylation by liquid hybridization capture-based bisulfite sequencing, which were used for conjoint analysis with our previous data of gene expression by cDNA microarray to identify functional methylated genes, as well as hub genes selected by protein-protein interaction (PPI) network analysis, and functional enrichment analyses were then performed. After RAGE knockout, 90 genes were identified by intersection of the differentially methylated genes and differentially expressed genes. According to the reversed effects of methylation in promoters on gene transcription, 14 genes with functional methylated modification were further identified, among which chemokine (C-X-C motif) ligand 1 (CXCL1), Toll-like receptor 6 (TLR6) and oncostatin M (OSM) with hypomethylation in promoters, were selected as the hub genes by PPI network analysis. Moreover, functional enrichment analyses showed the 14 functional methylated genes, including the 3 hub genes, were mainly enriched in immune-inflammatory responses, especially mitogen-activated protein kinase, tumor necrosis factor, TLRs, interleukin (IL)-6 and IL-17 pathways. The present study suggests that RAGE mediates functional DNA methylated modification in a cluster of 14 targeted genes, particularly hypomethylation in promoters of CXCL1, TLR6 and OSM, which might significantly contribute to CS-induced airway inflammation via a network of signaling pathways.

The Role of Interleukin-1β in Destruction of Transplanted Islets

Islet transplantation is a promising β-cell replacement therapy for type 1 diabetes, which can reduce glucose lability and hypoglycemic episodes compared with standard insulin therapy. Despite the tremendous progress made in this field, challenges remain in terms of long-term successful transplant outcomes. The insulin independence rate remains low after islet transplantation from one donor pancreas. It has been reported that the islet-related inflammatory response is the main cause of early islet damage and graft loss after transplantation. The production of interleukin-1β (IL-1β) has considered to be one of the primary harmful inflammatory events during pancreatic procurement, islet isolation, and islet transplantation. Evidence suggests that the innate immune response is upregulated through the activity of Toll-like receptors and The NACHT Domain-Leucine-Rich Repeat and PYD-containing Protein 3 inflammasome, which are the starting points for a series of signaling events that drive excessive IL-1β production in islet transplantation. In this review, we show recent contributions to the advancement of knowledge of IL-1β in islet transplantation and discuss several strategies targeting IL-1β for improving islet engraftment.

Role of Tet2 in Regulating Adaptive and Innate Immunity

Accumulated evidence indicates that epigenetic modifications play central roles in gene expression regulation and participate in developing many autoimmune and autoinflammatory diseases. Mechanistically, epigenetic modifications act as a bridge between environmental and cellular factors and susceptibility genes. DNA methylation is a critical epigenetic modification that is regulated by ten-eleven translocation (TET) enzymes. Accumulating evidence has revealed that TET family proteins function as gene regulators and antitumor drug targets mainly because of their ability to oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). Recently, the effect of Tet2, an essential TET protein, on the development of autoimmune diseases has been explored. In this review, we summarize the current understanding of Tet2 in immune response regulation, clarify the mechanisms of Tet2 in B and T cell differentiation and function, and discuss the opposing effects of Tet2 on inflammatory gene expression in the immune system to provide new potential therapeutic targets for related diseases.

Association of single-nucleotide polymorphisms in tumour necrosis factor and human leukocyte antigens genes with type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease characterized by progressive destruction of insulin-producing pancreatic beta cells. This multifactorial disease has a strong genetic component associated with the human leukocyte antigens (HLA) and non-HLA regions. In this study, we compared frequencies of HLA-DRB1 alleles and single-nucleotide polymorphisms (SNPs) associated the genes coding for: toll-like receptors (TLRs), tumour necrosis factor (TNF), interleukin-1 (IL-1), interleukin-1 receptor type 1 (IL-1R1), interleukin-1 receptor antagonist (IL-1RN), interleukin-2 (IL-2) and interleukin-12B (IL-12B), between T1D patients and healthy controls. The aim was to identify frequency differences and linkage between these genetic markers in T1D patients and healthy controls. Twelve SNPs were investigated as follows: rs16944 (IL-1B), rs1143634 (IL-1B), rs1800587 (IL-1A), rs2069762 (IL-2), rs3212227 (IL-12B), rs2234650 (IL-1R1), rs315952 (IL-1RN), rs3804099 (TLR2), rs4986790 (TLR4), rs4986791 (TLR4), rs1800629 (TNF) and rs361525 (TNF). TaqMan genotype assay method was used for SNPs genotyping. HLA-DRB1* genes were typed by Sequence Specific Oligonucleotide Probe (SSOP). SPSS and SNPStats programs were used for the statistical analysis. Significant differences between T1D and control groups were found for the dominant model of rs361525 and rs1800629A:rs361525G genotypes for TNF. Increased frequencies of DRB1*03 and DRB1*04 and decreased frequencies of DRB1*07, DRB1*11 and DRB1*13 and DRB1*15 were observed in T1D patients compared with controls. However, the genotype, DRB1*07 with rs1800629A/G was associated with T1D. We have confirmed that DRB1*03 and DRB1*04 are associated with increased risk and DRB1*07, DRB1*11 and DRB1*13 and DRB1*15 with decreased risk of T1D. Also, the dominant model of rs361525A, and the rs1800629G:361525A genotype were associated with increased risk. The simultaneous presence of DRB1*07 and rs1800629A/G genotypes in 23 out of 27 DRB1*07 positive T1D patients implied that islet cell peptide processing may have been biased towards autoimmunity by upregulation of TNF associated intronic SNPs.

Phosphorylated Heat Shock Protein 27 Inhibits Lipopolysaccharide-Induced Inflammation in Thp1 Cells by Promoting TLR4 Endocytosis, Ubiquitination, and Degradation

The aims of this study were to investigate the effect of Hsp27 on LPS-induced inflammation and identify the precise mechanisms about how Hsp27 regulates LPS-induced TLR4 signaling in Thp1 cells. Thp1 cells were transfected with Flag-Hsp27 or pcDNA3.1, and then treated with LPS for indicated time. TNF-α, IL-1β, and IL-6 were determined by ELISA. The protein levels of Hsp27, p-Hsp27 (Ser15, Ser78, and Ser82), and TLR4 were measured by Western blotting. In vitro study showed that over-expression of Hsp27 downregulated the release of TNF-α, IL-1β, and IL-6 and suppressed the activation of TLR4 signals after stimulated by LPS. The location of TLR4 and RAB5 was detected by confocal microscopy. Immunoprecipitation was used to determine the ubiquitination and degradation of TLR4 and interaction between Hsp27 and TLR4. Results showed that Hsp27 could promote TLR4 endocytosis and ubiquitination and degradation. Further research revealed that Hsp27 was phosphorylated after LPS, only phosphorylated Hsp27 can interact with TLR4 and inhibit the activation of TLR4 signaling, which was demonstrated by inhibition of Hsp27 phosphorylation with inhibitors or transfection of Hsp27 mutants into Thp1 cells. Phosphorylated Hsp27 reduced the release of TNF-α, IL-1β, and IL-6, and suppressed the activation of TLR4 signaling by promoting TLR4 endocytosis, ubiquitination, and degradation.

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.

A novel epigenetic mechanism of FXR inhibiting GLP-1 secretion via miR-33 and its downstream targets

Type II diabetes is a complex, chronic, and progressive disease. Previously, we demonstrate that FXR inhibits GLP-1 secretion via interacting with CREB to inhibit the transcriptional activity of CREB, thus promoting the development of type II diabetes. Epigenetic modifications, such as DNA methylation, histone acetylation, and post-transcriptional RNA regulation, are essential mediators contributing to diabetes-associated morbidity and mortality. Thus, we attempted to investigate the epigenetic mechanisms of FXR modulating GLP-1 secretion. Firstly, the involvement of histone acetylation, DNA methylation, and post-transcriptional regulation in FXR inhibiting GLP-1 secretion was verified. As FXR overexpression significantly inhibited the activity of GCG 3'-UTR, we hypothesize that miRNA might participate in the mechanism. Two online tools and real-time PCR revealed that FXR promoted miR-33 expression. Moreover, miR-33 inhibited the expression of GCG and CREB1 through direct targeting in STC-1 cells. FXR overexpression in STC-1 cells significantly reduced the mRNA expression and protein levels of both GCG and CREB1, as well as the secretion of GLP-1; miR-33 inhibition exerted opposing effects. More importantly, the effects of FXR overexpression were significantly reversed by miR-33 inhibition, indicating that FXR inhibited GLP-1 secretion through promoting miR-33 expression, therefore inhibiting the expression of miR-33 targets, GCG and CREB1. In conclusion, we provide a novel epigenetic mechanism by which FXR inhibits the secretion of GLP-1 through miR-33 and its two downstream targets, GCG and CREB1. These findings might provide innovative strategies for improving type II diabetes, which needs further in vivo and clinical investigation.

MicroRNA Post-transcriptional Regulation of the NLRP3 Inflammasome in Immunopathologies

Inflammation has a crucial role in protection against various pathogens. The inflammasome is an intracellular multiprotein signaling complex that is linked to pathogen sensing and initiation of the inflammatory response in physiological and pathological conditions. The most characterized inflammasome is the NLRP3 inflammasome, which is a known sensor of cell stress and is tightly regulated in resting cells. However, altered regulation of the NLRP3 inflammasome is found in several pathological conditions, including autoimmune disease and cancer. NLRP3 expression was shown to be post-transcriptionally regulated and multiple miRNA have been implicated in post-transcriptional regulation of the inflammasome. Therefore, in recent years, miRNA based post-transcriptional control of NLRP3 has become a focus of much research, especially as a potential therapeutic approach. In this review, we provide a summary of the recent investigations on the role of miRNA in the post-transcriptional control of the NLRP3 inflammasome, a key regulator of pro-inflammatory IL-1β and IL-18 cytokine production. Current approaches to targeting the inflammasome product were shown to be an effective treatment for diseases linked to NLRP3 overexpression. Although utilizing NLRP3 targeting miRNAs was shown to be a successful therapeutic approach in several animal models, their therapeutic application in patients remains to be determined.

Probiotics and Prebiotics for the Amelioration of Type 1 Diabetes: Present and Future Perspectives

Type 1-diabetes (T1D) is an autoimmune disease characterized by immune-mediated destruction of pancreatic beta (β)-cells. Genetic and environmental interactions play an important role in immune system malfunction by priming an aggressive adaptive immune response against β-cells. The microbes inhabiting the human intestine closely interact with the enteric mucosal immune system. Gut microbiota colonization and immune system maturation occur in parallel during early years of life; hence, perturbations in the gut microbiota can impair the functions of immune cells and vice-versa. Abnormal gut microbiota perturbations (dysbiosis) are often detected in T1D subjects, particularly those diagnosed as multiple-autoantibody-positive as a result of an aggressive and adverse immunoresponse. The pathogenesis of T1D involves activation of self-reactive T-cells, resulting in the destruction of β-cells by CD8⁺ T-lymphocytes. It is also becoming clear that gut microbes interact closely with T-cells. The amelioration of gut dysbiosis using specific probiotics and prebiotics has been found to be associated with decline in the autoimmune response (with diminished inflammation) and gut integrity (through increased expression of tight-junction proteins in the intestinal epithelium). This review discusses the potential interactions between gut microbiota and immune mechanisms that are involved in the progression of T1D and contemplates the potential effects and prospects of gut microbiota modulators, including probiotic and prebiotic interventions, in the amelioration of T1D pathology, in both human and animal models.

Epigenetic Control of Pancreatic Regeneration in Diabetes

Both type 1 and type 2 diabetes are conditions that are associated with the loss of insulin-producing β-cells within the pancreas. An active research therefore aims at regenerating these β-cells with the hope that they could restore euglycemia. The approaches classically used consist in mimicking embryonic development, making use of diverse cell sources or converting pre-existing pancreatic cells. Despite impressive progresses and promising successes, it appears that we still need to gain further insight into the molecular mechanisms underlying β-cell development. This becomes even more obvious with the emergence of a relatively new field of research, epigenetics. The current review therefore focuses on the latest advances in this field in the context of β-cell (neo-)genesis research.