Association of RPS26 gene polymorphism with different types of diabetes in Chinese individuals.

AIMS/INTRODUCTION: Different types of diabetes show distinct genetic characteristics, but the specific genetic susceptibility factors remain unclear. Our study aimed to explore the associations between the ribosomal protein S26 (RPS26) gene rs1131017 polymorphisms and susceptibility to type 1 diabetes mellitus, latent autoimmune diabetes in adults (LADA) and type 2 diabetes mellitus in the Chinese Han population, and their correlations with clinical features. MATERIALS AND METHODS: Genotyping of the rs1131017 variant was carried out for 1,006 type 1 diabetes mellitus patients, 210 LADA patients, 642 type 2 diabetes mellitus patients and 2,099 control individuals. RESULTS: We found that the rs1131017 C allele was a risk locus for both type 1 diabetes mellitus and LADA (odds ratio [OR] 1.50, 95% confidence interval [CI] 1.33-1.69, P < 0.001; OR 1.31, 95% CI 1.04-1.64, P = 0.021, respectively). Nevertheless, this association was not found for type 2 diabetes mellitus. Carrying the C allele genotype was associated with a lower postprandial C-peptide for type 1 diabetes mellitus (OR 1.41, 95% CI 1.11-1.80, P = 0.006) and lower fasting C-peptide for LADA (OR 1.55, 95% CI 1.01-2.38, P = 0.047). Interestingly, a lower GC frequency was noted for LADA than for type 1 diabetes mellitus, regardless of classification based on age at diagnosis, C-peptide or glutamic acid decarboxylase antibody positivity. CONCLUSIONS: The RPS26 polymorphism was associated with susceptibility and clinical characteristics of type 1 diabetes mellitus and LADA in the Chinese population, but was not related to type 2 diabetes mellitus. Thus, it might serve as a novel biomarker for particular types of diabetes.

Distinct signatures of gut microbiota and metabolites in different types of diabetes: a population-based cross-sectional study.

Background: Patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) present intestinal disturbances. Recent epidemiological data have showed that, worldwide, over half of newly diagnosed T1D patients were adults. However, the gut microbial alterations in adult-onset T1D are unclear. We aimed to identify the signatures of gut microbiota and metabolites in patients with adult-onset T1D systematically, comparing with T2D patients and healthy controls (HCs). Methods: This study enrolled 218 subjects from February 2019 to April 2022 (discovery cohort: 36 HCs, 51 patients with adult-onset T1D and 56 patients with T2D; validation cohort: 28 HCs, 27 patients with adult-onset T1D and 20 patients with T2D). Gut microbial profiles of the study subjects were investigated by metagenomic sequencing, and their faecal and serum metabolites were measured with targeted metabolomics. The study was registered on ClinicalTrials.gov (NCT05252728). Findings: Patients with adult-onset T1D had significant differences in the composition of bacteria and their metabolites, characterized by notable depletion of short-chain fatty acid-producing bacteria, especially Eubacterium rectale. This was associated with a severe loss of phenolic acids and their derivatives, including gallic acid (associated with glucose metabolism) and 3,4-dihydroxyhydrocinnamic acid (linked with glucose metabolism and pancreatic beta cell autoimmunity). A predictive model based on six bacteria and six metabolites simultaneously discriminated adult-onset T1D from T2D and HCs with high accuracy. Interestingly, bacterial-viral or bacterial-fungal trans-kingdom relationships, especially positive correlations between bacteriophages and beneficial bacteria, were significantly reduced in adult-onset T1D compared to HCs. Interpretation: Adult-onset T1D patients exhibit unique changes in host-microbiota-metabolite interactions. Gut microbiota and metabolite-based algorithms could be used as additional tools for differential diagnosis of different types of diabetes and beyond. Funding: National Key Research and Development Program of China, the National Natural Science Foundation of China.

Lipid metabolism in type 1 diabetes mellitus: Pathogenetic and therapeutic implications.

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease with insulin deficiency due to pancreatic ß cell destruction. Multiple independent cohort studies revealed specific lipid spectrum alterations prior to islet autoimmunity in T1DM. Except for serving as building blocks for membrane biogenesis, accumulative evidence suggests lipids and their derivatives can also modulate different biological processes in the progression of T1DM, such as inflammation responses, immune attacks, and ß cell vulnerability. However, the types of lipids are huge and majority of them have been largely unexplored in T1DM. In this review, based on the lipid classification system, we summarize the clinical evidence on dyslipidemia related to T1DM and elucidate the potential mechanisms by which they participate in regulating inflammation responses, modulating lymphocyte function and influencing ß cell susceptibility to apoptosis and dysfunction. This review systematically recapitulates the role and mechanisms of various lipids in T1DM, providing new therapeutic approaches for T1DM from a nutritional perspective.

A novel genomic instability-derived lncRNA signature to predict prognosis and immune characteristics of pancreatic ductal adenocarcinoma.

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignant tumor of the digestive system. Its grim prognosis is mainly attributed to the lack of means for early diagnosis and poor response to treatments. Genomic instability is shown to be an important cancer feature and prognostic factor, and its pattern and extent may be associated with poor treatment outcomes in PDAC. Recently, it has been reported that long non-coding RNAs (lncRNAs) play a key role in maintaining genomic instability. However, the identification and clinical significance of genomic instability-related lncRNAs in PDAC have not been fully elucidated. Methods: Genomic instability-derived lncRNA signature (GILncSig) was constructed based on the results of multiple regression analysis combined with genomic instability-associated lncRNAs and its predictive power was verified by the Kaplan-Meier method. And real-time quantitative polymerase chain reaction (qRT-PCR) was used for simple validation in human cancers and their adjacent non-cancerous tissues. In addition, the correlation between GILncSig and tumor microenvironment (TME) and epithelial-mesenchymal transition (EMT) was investigated by Pearson correlation analysis. Results: The computational framework identified 206 lncRNAs associated with genomic instability in PDAC and was subsequently used to construct a genome instability-derived five lncRNA-based gene signature. Afterwards, we successfully validated its prognostic capacity in The Cancer Genome Atlas (TCGA) cohort. In addition, via careful examination of the transcriptome expression profile of PDAC patients, we discovered that GILncSig is associated with EMT and an adaptive immunity deficient immune profile within TME. Conclusions: Our study established a genomic instability-associated lncRNAs-derived model (GILncSig) for prognosis prediction in patients with PDAC, and revealed the potential functional regulatory role of GILncSig.

Latent Autoimmune Diabetes in Adults (LADA): From Immunopathogenesis to Immunotherapy.

Latent autoimmune diabetes in adults (LADA) is a type of diabetes characterized by slow autoimmune damage of pancreatic ß cells without insulin treatment in the early clinical stage. There are differences between LADA and classical type 1 diabetes (T1D) and type 2 diabetes (T2D) in genetic background, autoimmune response, rate of islet function decline, clinical metabolic characteristics, and so on. The disease progression and drug response of patients with LADA are closely related to the level of islet autoimmunity, thus exploring the pathogenesis of LADA is of great significance for its prevention and treatment. Previous studies reported that adaptive immunity and innate immunity play a critical role in the etiology of LADA. Recent studies have shown that the intestinal microbiota which impacts host immunity hugely, participates in the pathogenesis of LADA. In addition, the progression of autoimmune pancreatic ß cell destruction in LADA is slower than in classical T1D, providing a wider window of opportunities for intervention. Therefore, therapies including antidiabetic drugs with immune-regulation effects and immunomodulators could contribute to promising interventions for LADA. We also shed light on potential interventions targeting the gut microbiota and gut-associated immunity, which may be envisaged to halt or delay the process of autoimmunity in LADA.

Emerging Roles of Sodium Glucose Cotransporter 2 (SGLT-2) Inhibitors in Diabetic Cardiovascular Diseases: Focusing on Immunity, Inflammation and Metabolism.

Diabetes mellitus (DM) is one of the most fast evolving global issues characterized by hyperglycemia. Patients with diabetes are considered to face with higher risks of adverse cardiovascular events. Those are the main cause of mortality and disability in diabetes patients. There are novel antidiabetic agents that selectively suppress sodium-glucose cotransporter-2 (SGLT-2). They work by reducing proximal tubule glucose reabsorption. Although increasing evidence has shown that SGLT-2 inhibitors can contribute to a series of cardiovascular benefits in diabetic patients, including a reduced incidence of major adverse cardiovascular events and protection of extracardiac organs, the potential mechanisms of SGLT2 inhibitors' cardiovascular protective effects are still not fully elucidated. Given the important role of inflammation and metabolism in diabetic cardiovascular diseases, this review is intended to rationally compile the multifactorial mechanisms of SGLT-2 inhibitors from the point of immunity, inflammation and metabolism, depicting the fundamental cellular and molecular processing of SGLT-2 inhibitors exerting regulating immunity, inflammation and metabolism. Finally, future directions and perspectives to prevent or delay cardiovascular complications in DM by SGLT-2 inhibitors are presented.

Effects of Immunomodulatory Drug Fingolimod (FTY720) on Chlamydia Dissemination and Pathogenesis.

Fingolimod (FTY720), an FDA-approved immunomodulatory drug for treating multiple sclerosis, is an agonist of sphingosine-1-phosphate receptor (S1PR), which has been used as a research tool for inhibiting immune cell trafficking. FTY720 was recently reported to inhibit Chlamydia dissemination. Since genital Chlamydia spreading to the gastrointestinal tract correlated with its pathogenicity in the upper genital tract, we evaluated the effect of FTY720 on chlamydial pathogenicity in the current study. Following an intravaginal inoculation, live chlamydial organisms were detected in mouse rectal swabs. FTY720 treatment significantly delayed live organism shedding in the rectal swabs. However, FTY720 failed to block chlamydial spreading to the gastrointestinal tract. The live chlamydial organisms recovered from rectal swabs reached similar levels between mice with or without FTY720 treatment by day 42 in C57BL/6J and day 28 in CBA/J mice, respectively. Thus, genital Chlamydia is able to launch a 2nd wave of spreading via an FTY720-resistant pathway after the 1st wave of spreading is inhibited by FTY720. As a result, all mice developed significant hydrosalpinx. The FTY720-resistant spreading led to stable colonization of chlamydial organisms in the colon. Consistently, FTY720 did not alter the colonization of intracolonically inoculated Chlamydia Thus, we have demonstrated that, following a delay in chlamydial spreading caused by FTY720, genital Chlamydia is able to both spread to the gastrointestinal tract via an FTY720-resistant pathway and maintain its pathogenicity in the upper genital tract. Further characterization of the FTY720-resistant pathway(s) explored by Chlamydia for spreading to the gastrointestinal tract may promote our understanding of Chlamydia pathogenic mechanisms.

Suppression of Chlamydial Pathogenicity by Nonspecific CD8+ T Lymphocytes.

Chlamydia trachomatis, a leading infectious cause of tubal infertility, induces upper genital tract pathology, such as hydrosalpinx, which can be modeled with Chlamydia muridarum infection in mice. Following C. muridarum inoculation, wild-type mice develop robust hydrosalpinx, but OT1 mice fail to do so because their T cell receptors are engineered to recognize a single ovalbumin epitope (OVA457-462). These observations have demonstrated a critical role of Chlamydia-specific T cells in chlamydial pathogenicity. In the current study, we have also found that OT1 mice can actively inhibit chlamydial pathogenicity. First, depletion of CD8+ T cells from OT1 mice led to the induction of significant hydrosalpinx by Chlamydia, indicating that CD8+ T cells are necessary to inhibit chlamydial pathogenicity. Second, adoptive transfer of CD8+ T cells from OT1 mice to CD8 knockout mice significantly reduced chlamydial induction of hydrosalpinx, demonstrating that OT1 CD8+ T cells are sufficient for attenuating chlamydial pathogenicity in CD8 knockout mice. Finally, CD8+ T cells from OT1 mice also significantly inhibited hydrosalpinx development in wild-type mice following an intravaginal inoculation with Chlamydia Since T cells in OT1 mice are engineered to recognize only the OVA457-462 epitope, the above observations have demonstrated a chlamydial antigen-independent immune mechanism for regulating chlamydial pathogenicity. Further characterization of this mechanism may provide information for developing strategies to reduce infertility-causing pathology induced by infections.

Chlamydia muridarum Induces Pathology in the Female Upper Genital Tract via Distinct Mechanisms.

Sexually transmitted infection with Chlamydia trachomatis may lead to fibrotic blockage in women's upper genital tracts, resulting in tubal infertility. Intravaginal inoculation with C. muridarum readily induces fibrotic blockage or hydrosalpinx in mice and is used for investigating C. trachomatis pathogenicity. Using this model in combination with an antibody depletion approach, we confirmed CD4+ T cell-mediated protective immunity and a CD8+ T cell-dependent pathogenic mechanism during chlamydial infection in C57BL/6J mice. However, when mice genetically deficient in CD8+ T cells were evaluated, we found, surprisingly, that these mice were still able to develop robust hydrosalpinx following C. muridarum infection, both contradicting the observation made in C57BL/6J mice and suggesting a pathogenic mechanism that is independent of CD8+ T cells. We further found that depletion of CD4+ T cells from CD8+ T cell-deficient mice significantly reduced chlamydial induction of hydrosalpinx, indicating that CD4+ T cells became pathogenic in mice genetically deficient in CD8+ T cells. Since depletion of CD4+ T cells both promoted chlamydial infection and reduced chlamydial pathogenicity in CD8+ T cell-deficient mice, we propose that in the absence of CD8+ T cells, some CD4+ T cells may remain protective (as in C57BL/6J mice), while others may directly contribute to chlamydial pathogenicity. Thus, chlamydial pathogenicity can be mediated by distinct host mechanisms, depending upon host genetics and infection conditions. The CD8+ T cell-deficient mouse model may be useful for further investigating the mechanisms by which CD4+ T cells promote chlamydial pathogenicity.