Innate inflammation in type 1 diabetes

Understanding the link between different types of maternal diabetes and the onset of autism spectrum disorders

Autism spectrum disorders (ASD) encompass a collection of neurodevelopmental disorders that exhibit impaired social interactions and repetitive stereotypic behaviors. Although the exact cause of these disorders remains unknown, it is widely accepted that both genetic and environmental factors contribute to their onset and progression. Recent studies have highlighted the potential negative impact of maternal diabetes on embryonic neurodevelopment, suggesting that intrauterine hyperglycemia could pose an additional risk to early brain development and contribute to the development of ASD. This paper presents a comprehensive analysis of the current research on the relationship between various forms of maternal diabetes, such as type 1 diabetes mellitus, type 2 diabetes mellitus, and gestational diabetes mellitus, and the likelihood of ASD in offspring. The study elucidates the potential mechanisms through which maternal hyperglycemia affects fetal development, involving metabolic hormones, immune dysregulation, heightened oxidative stress, and epigenetic alterations. The findings of this review offer valuable insights for potential preventive measures and evidence-based interventions targeting ASD.

Monocytes in type 1 diabetes families exhibit high cytolytic activity and subset abundances that correlate with clinical progression

Monocytes are immune regulators implicated in the pathogenesis of type 1 diabetes (T1D), an autoimmune disease that targets insulin-producing pancreatic β cells. We determined that monocytes of recent onset (RO) T1D patients and their healthy siblings express proinflammatory/cytolytic transcriptomes and hypersecrete cytokines in response to lipopolysaccharide exposure compared to unrelated healthy controls (uHCs). Flow cytometry measured elevated circulating abundances of intermediate monocytes and >2-fold more CD14+CD16+HLADR+KLRD1+PRF1+ NK-like monocytes among patients with ROT1D compared to uHC. The intermediate to nonclassical monocyte ratio among ROT1D patients correlated with the decline in functional β cell mass during the first 24 months after onset. Among sibling nonprogressors, temporal decreases were measured in the intermediate to nonclassical monocyte ratio and NK-like monocyte abundances; these changes coincided with increases in activated regulatory T cells. In contrast, these monocyte populations exhibited stability among T1D progressors. This study associates heightened monocyte proinflammatory/cytolytic activity with T1D susceptibility and progression and offers insight to the age-dependent decline in T1D susceptibility.

Hepatic insulin synthesis increases in rat models of diabetes mellitus type 1 and 2 differently

Insulin-positive (+) cells (IPCs), detected in multiple organs, are of great interest as a probable alternative to ameliorate pancreatic beta-cells dysfunction and insulin deficiency in diabetes. Liver is a potential source of IPCs due to it common embryological origin with pancreas. We previously demonstrated the presence of IPCs in the liver of healthy and diabetic rats, but detailed description and analysis of the factors, which potentially can induced ectopic hepatic expression of insulin in type 1 (T1D) and type 2 diabetes (T2D), were not performed. In present study we evaluate mass of hepatic IPCs in the rat models of T1D and T2D and discuss factors, which may stimulate it generation: glycaemia, organ injury, involving of hepatic stem/progenitor cell compartment, expression of transcription factors and inflammation. Quantity of IPCs in the liver was up by 1.7-fold in rats with T1D and 10-fold in T2D compared to non-diabetic (ND) rats. We concluded that ectopic hepatic expression of insulin gene is activated by combined action of a number of factors, with inflammation playing a decision role.

Beneficial Effects of Dietary Flaxseed Oil through Inflammation Pathways and Gut Microbiota in Streptozotocin-Induced Diabetic Mice

Flaxseed oil (FO) has displayed potential anti-diabetes properties by providing a high content of α-linolenic acid. However, the effects and mechanisms of FO on type 1 diabetes are still unclear. The present study aims to explore the effects of different doses of FO feeding on hepatic inflammation and gut microbiota in streptozotocin-induced diabetic mice. Forty-eight six-week-old C57BL/6J male mice were divided into a control group (CON), a diabetic group (MOD), a diabetes with 7.0% w/w FO feeding group (FO-L), and a diabetes with 10.5% w/w FO feeding group (FO-H) for six weeks. The 7.0% w/w and 10.5% w/w FO feeding groups exhibited potential recovery of the number and size of pancreas tissues. The fasting blood glucose level was significantly decreased only after 4 weeks of feeding with 10.5% w/w FO in diabetic mice. The 10.5% w/w FO feeding group significantly decreased the postprandial blood glucose level of mice in the OGTT test. Hepatic glycogen levels were dramatically upregulated in the mice fed with both 7.0% w/w and 10.5% w/w FO. FO feeding significantly attenuated hepatic LPS, TNF-α, and IL-1β levels. In addition, we observed that 7.0% w/w and 10.5% w/w FO feedings notably downregulated hepatic gene and protein expressions of TLR4, MyD88, and P65. Furthermore, only 10.5% FO regulated fecal microbiota by increasing the relative abundance of the Bacteroidetes phylum, Lactococcus family, and Muribaculaceae and Streptococcaceae family and genus in streptozotocin-induced diabetic mice. Therefore, we conclude that FO feeding plays a role in anti-inflammation via the regulation of hepatic LPS/TLR4/MyD88 pathways and gut microbiota. In addition, different doses of FO supplementation may exhibit varying mechanisms in streptozotocin-induced mice.

Does hand stiffness reflect internal organ fibrosis in diabetes mellitus?

Fibrosis leads to irreversible stiffening of tissue and loss of function, and is a common pathway leading to morbidity and mortality in chronic disease. Diabetes mellitus (both type 1 and type 2 diabetes) are associated with significant fibrosis in internal organs, chiefly the kidney and heart, but also lung, liver and adipose tissue. Diabetes is also associated with the diabetic cheirarthropathies, a collection of clinical manifestations affecting the hand that include limited joint mobility (LJM), flexor tenosynovitis, Duypuytren disease and carpal tunnel syndrome. Histo-morphologically these are profibrotic conditions affecting various soft tissue components in the hand. We hypothesize that these hand manifestations reflect a systemic profibrotic state, and are potential clinical biomarkers of current or future internal organ fibrosis. Epidemiologically, there is evidence that fibrosis in one organ associates with fibrosis with another; the putative exposures that lead to fibrosis in diabetes (advanced glycation end product deposition, microvascular disease and hypoxia, persistent innate inflammation) are 'systemic'; a common genetic susceptibility to fibrosis has also been hinted at. These data suggest that a subset of the diabetic population is susceptible to multi-organ fibrosis. The hand is an attractive biomarker to clinically detect this susceptibility, owing to its accessibility to physical examination and exposure to repeated mechanical stresses. Testing the hypothesis has a few pre-requisites: being able to measure hand fibrosis in the hand, using clinical scores or imaging based scores, which will facilitate looking for associations with internal organ fibrosis using validated methodologies for each. Longitudinal studies would be essential in delineating fibrosis trajectories in those with hand manifestations. Since therapies reversing fibrosis are few, the onus lies on identification of a susceptible subset for preventative measures. If systematically validated, clinical hand examination could provide a low-cost, universally accessible and easily reproducible screening step in selecting patients for clinical trials for fibrosis in diabetes.

Association between dietary inflammatory index and risk of endometriosis: A population-based analysis

Background and aims

Chronic inflammation plays a significant role in the etiology of endometriosis, which might be affected by dietary intake. This study aimed to investigate the association between dietary inflammatory index (DII) and the risk of endometriosis.

Methods

A cross-sectional analysis using data from the National Health and Nutrition Examination Survey (1999-2006) was conducted on 3,410 American participants, among whom 265 reported a diagnosis of endometriosis. DII scores were calculated based on the dietary questionnaire. The association of DII scores with endometriosis was evaluated by adjusted multivariate logistic regression analyzes, which were further investigated in the subgroups.

Results

In the fully adjusted models, the odds ratio (OR) for endometriosis participants in the highest and middle tertiles of DII scores were 1.57 [95% confidence interval (CI): 1.14-2.17] and 1.18 (95% CI: 0.84-1.65), compared to the lowest tertile (P _trend = 0.007). In subgroup analyzes, the significant positive association between DII scores and the endometriosis risk was also observed in non-obese women (OR_tertile3vs1: 1.69, 95% CI: 1.12-2.55; P _trend = 0.012), women without diabetes (OR_tertile3vs1: 1.62, 95% CI: 1.16-2.27; P _trend = 0.005), women with hypertension (OR_tertile3vs1: 2.25, 95% CI: 1.31-3.87; P _trend = 0.003), parous women (OR_tertile3vs1: 1.55, 95% CI: 1.11-2.17; P _trend = 0.011), and women using oral contraceptives (OR_tertile3vs1: 1.63, 95% CI: 1.15-2.30; P _trend = 0.006).

Conclusion

This nationally representative study found that increased intake of the pro-inflammatory diet, as a higher DII score, was positively associated with endometriosis risk among American adults. Our results suggested anti-inflammatory dietary interventions may be promising in the prevention of endometriosis. Further prospective studies are necessary to confirm these findings.

Importance of Heparan Sulfate Proteoglycans in Pancreatic Islets and β-Cells

β-cells in the islets of Langerhans of the pancreas secrete insulin in response to the glucose concentration in the blood. When these pancreatic β-cells are damaged, diabetes develops through glucose intolerance caused by insufficient insulin secretion. High molecular weight polysaccharides, such as heparin and heparan sulfate (HS) proteoglycans, and HS-degrading enzymes, such as heparinase, participate in the protection, maintenance, and enhancement of the functions of pancreatic islets and β-cells, and the demand for studies on glycobiology within the field of diabetes research has increased. This review introduces the roles of complex glycoconjugates containing high molecular weight polysaccharides and their degrading enzymes in pancreatic islets and β-cells, including those obtained in studies conducted by us earlier. In addition, from the perspective of glycobiology, this study proposes the possibility of application to diabetes medicine.

Changes in the Coexpression of Innate Immunity Genes During Persistent Islet Autoimmunity Are Associated With Progression of Islet Autoimmunity: Diabetes Autoimmunity Study in the Young (DAISY)

Longitudinal changes in gene expression during islet autoimmunity (IA) may provide insight into biological processes that explain progression to type 1 diabetes (T1D). We identified individuals from Diabetes Autoimmunity Study in the Young (DAISY) who developed IA, autoantibodies present on two or more visits. Illumina's NovaSeq 6000 was used to quantify gene expression in whole blood. With linear mixed models we tested for changes in expression after IA that differed across individuals who progressed to T1D (progressors) (n = 25), reverted to an autoantibody-negative stage (reverters) (n = 47), or maintained IA positivity but did not develop T1D (maintainers) (n = 66). Weighted gene coexpression network analysis was used to identify coexpression modules. Gene Ontology pathway analysis of the top 150 differentially expressed genes (nominal P < 0.01) identified significantly enriched pathways including leukocyte activation involved in immune response, innate immune response, and regulation of immune response. We identified a module of 14 coexpressed genes with roles in the innate immunity. The hub gene, LTF, is known to have immunomodulatory properties. Another gene within the module, CAMP, is potentially relevant based on its role in promoting β-cell survival in a murine model. Overall, results provide evidence of alterations in expression of innate immune genes prior to onset of T1D.

Artemisia dracunculus L. Ethanolic Extract and an Isolated Component, DMC2, Ameliorate Inflammatory Signaling in Pancreatic β-Cells via Inhibition of p38 MAPK

Non-resolving pancreatic islet inflammation is widely viewed as a contributor to decreases in β-cell mass and function that occur in both Type 1 and Type 2 diabetes. Therefore, strategies aimed at reducing or eliminating pathological inflammation would be useful to protect islet β-cells. Herein, we described the use of 2′,4′-dihydroxy-4-methoxydihydrochalcone (DMC2), a bioactive molecule isolated from an ethanolic extract of Artemisia dracunculus L., as a novel anti-inflammatory agent. The ethanolic extract, termed PMI 5011, reduced IL-1β-mediated NF-κB activity. DMC2 retained this ability, indicating this compound as the likely source of anti-inflammatory activity within the overall PMI 5011 extract. We further examined NF-κB activity using promoter-luciferase reporter constructs, Western blots, mRNA abundance, and protein secretion. Specifically, we found that PMI 5011 and DMC2 each reduced the ability of IL-1β to promote increases in the expression of the Ccl2 and Ccl20 genes. These genes encode proteins that promote immune cell recruitment and are secreted by β-cells in response to IL-1β. Phosphorylation of IκBα and the p65 subunit of NF-κB were not reduced by either PMI 5011 or DMC2; however, phosphorylation of p38 MAPK was blunted in the presence of DMC2. Finally, we observed that while PMI 5011 impaired glucose-stimulated insulin secretion, insulin output was preserved in the presence of DMC2. In conclusion, PMI 5011 and DMC2 reduced inflammation, but only DMC2 did so with the preservation of glucose-stimulated insulin secretion.

Fluorine MR Imaging Probes Dynamic Migratory Profiles of Perfluorocarbon-Loaded Dendritic Cells After Streptozotocin-Induced Inflammation

PURPOSE

The pathogenesis of type 1 diabetes (T1D) involves presentation of islet-specific self-antigens by dendritic cells (DCs) to autoreactive T cells, resulting in the destruction of insulin-producing pancreatic beta cells. We aimed to study the dynamic homing of diabetes-prone DCs to the pancreas and nearby organs with and without induction of pancreatic stress in a T1D susceptible model of repeated streptozotocin (STZ) injection.

PROCEDURES

In vitro labeling of activated bone marrow-derived DCs (BMDCs) from NOD (Nonobese diabetes) mice was performed using zonyl perfluoro-15-crown-5-ether nanoparticles (ZPFCE-NPs). Internalization of particles was confirmed by confocal microscopy. Two groups of NOD.SCID (nonobese diabetic/severe combined immunodeficiency) mice with (induced by low dose STZ administration) or without pancreatic stress were compared. Diabetogenic BMDCs loaded with BDC2.5 mimotope were pre-labeled with ZPFCE-NPs and adoptively transferred into mice. Longitudinal in vivo fluorine MRI (19F MRI) was performed 24 h, 36 h and 48 h after transfer of BMDCs. For ex vivo quantification of labeled cells, 19F NMR and flow cytometry were performed on dissected tissues to validate in vivo 19F MRI data.

RESULTS

In vitro flow cytometry and confocal microscopy confirmed high uptake of nanoparticles in BMDCs during the process of maturation. Migration/homing of activated and ZPFCE-NP- labeled BMDCs to different organs was monitored and quantified longitudinally, showing highest cell density in pancreas at 48-h time-point. Based on 19F MRI, STZ induced mild inflammation in the pancreatic region, as indicated by high accumulation of ZPFCE-NP-labeled BMDCs in the pancreas when compared to the vehicle group. Pancreatic draining lymph nodes showed elevated homing of labeled BMDCs in the vehicle groups in contrast to the STZ group after 72 h. The effect of STZ was confirmed by increased blood glucose levels.

CONCLUSION

We showed the potential of 19F MRI for the non-invasive visualization and quantification of migrating immune cells in models for pancreatic inflammation after STZ administration. Without any intrinsic background signal, 19F MRI serves as a highly specific imaging tool to study the migration of diabetic-prone BMDCs in T1D models in vivo. This approach could particularly be of interest for the longitudinal assessment of established or novel anti-inflammatory therapeutic approaches in preclinical models.

Probiotic normalization of systemic inflammation in siblings of type 1 diabetes patients: an open-label pilot study

The incidence of type 1 diabetes (T1D) has increased, coinciding with lifestyle changes that have likely altered the gut microbiota. Dysbiosis, gut barrier dysfunction, and elevated systemic inflammation consistent with microbial antigen exposure, have been associated with T1D susceptibility and progression. A 6-week, single-arm, open-label pilot trial was conducted to investigate whether daily multi-strain probiotic supplementation could reduce this familial inflammation in 25 unaffected siblings of T1D patients. Probiotic supplementation was well-tolerated as reflected by high participant adherence and no adverse events. Community alpha and beta diversity were not altered between the pre- and post-supplement stool samplings. However, LEfSe analyses identified post-supplement enrichment of the family Lachnospiraceae, producers of the anti-inflammatory short chain fatty acid butyrate. Systemic inflammation was measured by plasma-induced transcription and quantified with a gene ontology-based composite inflammatory index (I.I._com). Post-supplement I.I._com was significantly reduced and pathway analysis predicted inhibition of numerous inflammatory mediators and activation of IL10RA. Subjects with the greatest post-supplement reduction in I.I._com exhibited significantly lower CD4+ CD45RO+ (memory):CD4+ CD45RA+ (naïve) T-cell ratios after supplementation. Post-supplement IL-12p40, IL-13, IL-15, IL-18, CCL2, and CCL24 plasma levels were significantly reduced, while post-supplement butyrate levels trended 1.4-fold higher. Probiotic supplementation may modify T1D susceptibility and progression and warrants further study.

The Relationships between Gut Microbiota and Diabetes Mellitus, and Treatments for Diabetes Mellitus

Diabetes mellitus is considered to be a global epidemic. The combination of genetic susceptibility and an unhealthy lifestyle is considered to be the main trigger of this metabolic disorder. Recently, there has been increased interest in the roles of gut microbiota as a new potential contributor to this epidemic. Research, in recent years, has contributed to an in-depth characterization of the human microbiome and its associations with various diseases, including metabolic diseases and diabetes mellitus. It is known that diet can change the composition of gut microbiota, but it is unclear how this, in turn, may influence metabolism. The main objective of this review is to evaluate the pathogenetic association between microbiota and diabetes and to explore any new therapeutic agents, including nutraceuticals that may modulate the microbiota. We also look at several mechanisms involved in this process. There is a clear, bidirectional relationship between microbiota and diabetes. Current treatments for diabetes influence microbiota in various ways, some beneficial, but others with still unclear effects. Microbiota-aimed treatments have seen no real-world significant effects on the progression of diabetes and its complications, with more studies needed in order to find a really beneficial agent.

Effector memory CD4+ T cells induce damaging innate inflammation and autoimmune pathology by engaging CD40 and TNFR on myeloid cells

Cytokine storm and sterile inflammation are common features of T cell-mediated autoimmune diseases and T cell-targeted cancer immunotherapies. Although blocking individual cytokines can mitigate some pathology, the upstream mechanisms governing overabundant innate inflammatory cytokine production remain unknown. Here, we have identified a critical signaling node that is engaged by effector memory T cells (T_EM) to mobilize a broad proinflammatory program in the innate immune system. Cognate interactions between T_EM and myeloid cells led to induction of an inflammatory transcriptional profile that was reminiscent, yet entirely independent, of classical pattern recognition receptor (PRR) activation. This PRR-independent "de novo" inflammation was driven by preexisting T_EM engagement of both CD40 and tumor necrosis factor receptor (TNFR) on myeloid cells. Cytokine toxicity and autoimmune pathology could be completely rescued by ablating these pathways genetically or pharmacologically in multiple models of T cell-driven inflammation, indicating that T_EM instruction of the innate immune system is a primary driver of associated immunopathology. Thus, we have identified a previously unknown trigger of cytokine storm and autoimmune pathology that is amenable to therapeutic interventions.

Signaling Pathways Related to Oxidative Stress in Diabetic Cardiomyopathy

Diabetes is a chronic metabolic disease that is increasing in prevalence and causes many complications. Diabetic cardiomyopathy (DCM) is a complication of diabetes that is associated with high mortality, but it is not well defined. Nevertheless, it is generally accepted that DCM refers to a clinical disease that occurs in patients with diabetes and involves ventricular dysfunction, in the absence of other cardiovascular diseases, such as coronary atherosclerotic heart disease, hypertension, or valvular heart disease. However, it is currently uncertain whether the pathogenesis of DCM is directly attributable to metabolic dysfunction or secondary to diabetic microangiopathy. Oxidative stress (OS) is considered to be a key component of its pathogenesis. The production of reactive oxygen species (ROS) in cardiomyocytes is a vicious circle, resulting in further production of ROS, mitochondrial DNA damage, lipid peroxidation, and the post-translational modification of proteins, as well as inflammation, cardiac hypertrophy and fibrosis, ultimately leading to cell death and cardiac dysfunction. ROS have been shown to affect various signaling pathways involved in the development of DCM. For instance, OS causes metabolic disorders by affecting the regulation of PPARα, AMPK/mTOR, and SIRT3/FOXO3a. Furthermore, OS participates in inflammation mediated by the NF-κB pathway, NLRP3 inflammasome, and the TLR4 pathway. OS also promotes TGF-β-, Rho-ROCK-, and Notch-mediated cardiac remodeling, and is involved in the regulation of calcium homeostasis, which impairs ATP production and causes ROS overproduction. In this review, we summarize the signaling pathways that link OS to DCM, with the intention of identifying appropriate targets and new antioxidant therapies for DCM.

Hypothalamic inflammation in metabolic disorders and aging

The hypothalamus is a critical brain region for the regulation of energy homeostasis. Over the years, studies on energy metabolism primarily focused on the neuronal component of the hypothalamus. Studies have recently uncovered the vital role of glial cells as an additional player in energy balance regulation. However, their inflammatory activation under metabolic stress condition contributes to various metabolic diseases. The recruitment of monocytes and macrophages in the hypothalamus helps sustain such inflammation and worsens the disease state. Neurons were found to actively participate in hypothalamic inflammatory response by transmitting signals to the surrounding non-neuronal cells. This activation of different cell types in the hypothalamus leads to chronic, low-grade inflammation, impairing energy balance and contributing to defective feeding habits, thermogenesis, and insulin and leptin signaling, eventually leading to metabolic disorders (i.e., diabetes, obesity, and hypertension). The hypothalamus is also responsible for the causation of systemic aging under metabolic stress. A better understanding of the multiple factors contributing to hypothalamic inflammation, the role of the different hypothalamic cells, and their crosstalks may help identify new therapeutic targets. In this review, we focus on the role of glial cells in establishing a cause-effect relationship between hypothalamic inflammation and the development of metabolic diseases. We also cover the role of other cell types and discuss the possibilities and challenges of targeting hypothalamic inflammation as a valid therapeutic approach.

Increased spontaneous CCL2 (MCP-1) and CCL5 (RANTES) secretion in vitro in LADA compared to type 1 diabetes and type 2 diabetes: Action LADA 14

AIMS

Immune-mediated type 1 diabetes (T1D) in adulthood and latent autoimmune diabetes in adults (LADA) share similar pathological mechanisms but differ clinically in disease progression. The aim of this study was to acquire insights into spontaneous and stimulated chemokine secretion of immune cells in different diabetes types.

MATERIALS AND METHODS

We investigated in vitro spontaneous, mitogen (PI) and antigen (HSP60, p277, pGAD, pIA2) stimulated chemokine secretion of leucocytes from patients with T1D (n = 32), LADA (n = 22), type 2 diabetes (T2D; n = 49), and glucose-tolerant individuals (n = 13). Chemokine concentration in supernatants was measured for CCL2 (MCP-1), CXCL10 (IP10) and CCL5 (RANTES) using a multiplex bead array assay.

RESULTS

Spontaneous secretion of CCL2 and CCL5 were higher in LADA compared to T1D and T2D (all p < 0.05) while CXCL10 was similar in the groups. Mitogen-stimulated secretion of CCL2 in LADA was lower compared to T1D and T2D (all p < 0.05) while CXCL10 and CCL5 were similar in all groups. Upon stimulation with pIA2 the secretion of CCL2 in LADA was lower compared to T2D (p < 0.05). Spontaneous CXCL10 secretion in LADA was positively associated with body mass index (r²  = 0.35; p = 0.0035) and C-peptide (r²  = 0.30; p = 0.009).

CONCLUSIONS

Chemokine secretion is altered between different diabetes types. Increased spontaneous secretion of CCL2 and CCL5 and decreased secretion of CCL2, upon stimulation with PI and pIA2, in LADA compared to T1D and T2D could reflect altered immune responsiveness in LADA patients in association with their slower clinical progression compared to insulin dependence.

The oxylipin profile is associated with development of type 1 diabetes: the Diabetes Autoimmunity Study in the Young (DAISY)

AIMS/HYPOTHESIS

Oxylipins are lipid mediators derived from polyunsaturated fatty acids. Some oxylipins are proinflammatory (e.g. those derived from arachidonic acid [ARA]), others are pro-resolving of inflammation (e.g. those derived from α-linolenic acid [ALA], docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) and others may be both (e.g. those derived from linoleic acid [LA]). The goal of this study was to examine whether oxylipins are associated with incident type 1 diabetes.

METHODS

We conducted a nested case-control analysis in the Diabetes Autoimmunity Study in the Young (DAISY), a prospective cohort study of children at risk of type 1 diabetes. Plasma levels of 14 ARA-derived oxylipins, ten LA-derived oxylipins, six ALA-derived oxylipins, four DHA-derived oxylipins and two EPA-related oxylipins were measured by ultra-HPLC-MS/MS at multiple timepoints related to autoantibody seroconversion in 72 type 1 diabetes cases and 71 control participants, which were frequency matched on age at autoantibody seroconversion (of the case), ethnicity and sample availability. Linear mixed models were used to obtain an age-adjusted mean of each oxylipin prior to type 1 diabetes. Age-adjusted mean oxylipins were tested for association with type 1 diabetes using logistic regression, adjusting for the high risk HLA genotype HLA-DR3/4,DQB1*0302. We also performed principal component analysis of the oxylipins and tested principal components (PCs) for association with type 1 diabetes. Finally, to investigate potential critical timepoints, we examined the association of oxylipins measured before and after autoantibody seroconversion (of the cases) using PCs of the oxylipins at those visits.

RESULTS

The ARA-related oxylipin 5-HETE was associated with increased type 1 diabetes risk. Five LA-related oxylipins, two ALA-related oxylipins and one DHA-related oxylipin were associated with decreased type 1 diabetes risk. A profile of elevated LA- and ALA-related oxylipins (PC1) was associated with decreased type 1 diabetes risk (OR 0.61; 95% CI 0.40, 0.94). A profile of elevated ARA-related oxylipins (PC2) was associated with increased diabetes risk (OR 1.53; 95% CI 1.03, 2.29). A critical timepoint analysis showed type 1 diabetes was associated with a high ARA-related oxylipin profile at post-autoantibody-seroconversion but not pre-seroconversion.

CONCLUSIONS/INTERPRETATION

The protective association of higher LA- and ALA-related oxylipins demonstrates the importance of both inflammation promotion and resolution in type 1 diabetes. Proinflammatory ARA-related oxylipins may play an important role once the autoimmune process has begun.

Oxyberberine, an absorbed metabolite of berberine, possess superior hypoglycemic effect via regulating the PI3K/Akt and Nrf2 signaling pathways

Berberine (BBR) is a promising anti-diabetic isoquinoline alkaloid from Rhizoma coptidis, while its bioavailability was extremely low. Here, the existing form and pharmacokinetics of BBR were comparatively characterized in conventional and antibiotic-induced pseudo germ-free (PGF) rats. Furthermore, we comparatively investigated the antidiabetic effect and potential mechanism of BBR and its intestinal oxidative metabolite oxyberberine (OBB) in STZ-induced diabetic rats. Results showed that BBR and OBB existed mainly as protein-bound form in blood, while protein-bound OBB was significantly depleted in PGF rats. Treatment with OBB and BBR effectively decreased clinical symptoms of diabetic rats, reduced blood glucose level, ameliorated the pancreatic damage, and mitigated oxidative stress and inflammatory markers. However, the anti-diabetes effect of BBR was obviously compromised by antibiotics. In addition, OBB exerted superior anti-diabetes effect to BBR of the same dose, significantly up-regulated the mRNA expression of Nrf2 signaling pathway and substantially promoted the pancreatic levels of PI3K/Akt signaling pathway. In conclusion, BBR and its absorbed oxidative metabolite OBB were mainly presented and transported in the protein-bound form in vivo. The gut microbiota may play an important role in the anti-diabetes effect of BBR through transforming itself into the superior hypoglycemic metabolite OBB. OBB possessed favorable hypoglycemic and pancreatic β-cells protective effects, which may stand a huge potential to be further developed into a promising anti-diabetes candidate.

Duodenal mucosal mitochondrial gene expression is associated with delayed gastric emptying in diabetic gastroenteropathy

Hindered by a limited understanding of the mechanisms responsible for diabetic gastroenteropathy (DGE), management is symptomatic. We investigated the duodenal mucosal expression of protein-coding genes and microRNAs (miRNA) in DGE and related them to clinical features. The diabetic phenotype, gastric emptying, mRNA, and miRNA expression and ultrastructure of duodenal mucosal biopsies were compared in 39 DGE patients and 21 controls. Among 3175 differentially expressed genes (FDR < 0.05), several mitochondrial DNA–encoded (mtDNA-encoded) genes (12 of 13 protein coding genes involved in oxidative phosphorylation [OXPHOS], both rRNAs and 9 of 22 transfer RNAs) were downregulated; conversely, nuclear DNA–encoded (nDNA-encoded) mitochondrial genes (OXPHOS) were upregulated in DGE. The promoters of differentially expressed genes were enriched in motifs for transcription factors (e.g., NRF1), which regulate mitochondrial biogenesis. Seventeen of 30 differentially expressed miRNAs targeted differentially expressed mitochondrial genes. Mitochondrial density was reduced and correlated with expression of 9 mtDNA OXPHOS genes. Uncovered by principal component (PC) analysis of 70 OXPHOS genes, PC1 was associated with neuropathy (P = 0.01) and delayed gastric emptying (P < 0.05). In DGE, mtDNA- and nDNA-encoded mitochondrial genes are reduced and increased — associated with reduced mitochondrial density, neuropathy, and delayed gastric emptying — and correlated with cognate miRNAs. These findings suggest that mitochondrial disturbances may contribute to delayed gastric emptying in DGE.

Role of Innate Inflammation in the Regulation of Tissue Remodeling during Tooth Eruption

Tooth eruption is characterized by a coordinated complex cascade of cellular and molecular events that promote tooth movement through the eruptive pathway. During tooth eruption, the stratum intermedium structurally changes to the papillary layer with tooth organ development. We previously reported intercellular adhesion molecule-1 (ICAM-1) expression on the papillary layer, which is the origin of the ICAM-1-positive junctional epithelium. ICAM-1 expression is induced by proinflammatory cytokines, including interleukin-1 and tumor necrosis factor. Inflammatory reactions induce tissue degradation. Therefore, this study aimed to examine whether inflammatory reactions are involved in tooth eruption. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed sequential expression of hypoxia-induced factor-1α, interleukin-1β, and chemotactic factors, including keratinocyte-derived chemokine (KC) and macrophage inflammatory protein-2 (MIP-2), during tooth eruption. Consistent with the RT-PCR results, immunohistochemical analysis revealed KC and MIP-2 expression in the papillary layer cells of the enamel organ from the ameloblast maturation stage. Moreover, there was massive macrophage and neutrophil infiltration in the connective tissue between the tooth organ and oral epithelium during tooth eruption. These findings suggest that inflammatory reactions might be involved in the degradation of tissue overlying the tooth organ. Further, these reactions might be induced by hypoxia in the tissue overlying the tooth organ, which results from decreased capillaries in the tissue. Our findings indicate that bacterial infections are not associated with the eruption process. Therefore, tooth eruption might be regulated by innate inflammatory mechanisms.

Upstream Regulators of Fibroblast Growth Factor 23

Fibroblast growth factor 23 (FGF23) has been described as an important regulator of mineral homeostasis, but has lately also been linked to iron deficiency, inflammation, and erythropoiesis. FGF23 is essential for the maintenance of phosphate homeostasis in the body and activating mutations in the gene itself or inactivating mutations in its upstream regulators can result in severe chronic hypophosphatemia, where an unbalanced mineral homeostasis often leads to rickets in children and osteomalacia in adults. FGF23 can be regulated by changes in transcriptional activity or by changes at the post-translational level. The balance between O-glycosylation and phosphorylation is an important determinant of how much active intact or inactive cleaved FGF23 will be released in the circulation. In the past years, it has become evident that iron deficiency and inflammation regulate FGF23 in a way that is not associated with its classical role in mineral metabolism. These conditions will not only result in an upregulation of FGF23 transcription, but also in increased cleavage, leaving the levels of active intact FGF23 unchanged. The exact mechanisms behind and function of this process are still unclear. However, a deeper understanding of FGF23 regulation in both the classical and non-classical way is important to develop better treatment options for diseases associated with disturbed FGF23 biology. In this review, we describe how the currently known upstream regulators of FGF23 change FGF23 transcription and affect its post-translational modifications at the molecular level.

Phytochemicals as Anti-Inflammatory Agents in Animal Models of Prevalent Inflammatory Diseases

Phytochemicals are known to have anti-inflammatory effects in vitro and in vivo, such as in inflammatory disease model systems. Inflammation is an essential immune response to exogenous stimuli such as infection and injury. Although inflammation is a necessary host-defense mechanism, chronic inflammation is associated with the continuous local or systemic release of inflammatory mediators, non-cytokine mediators, such as ROS and NO, and inflammatory cytokines are strongly implicated in the pathogenesis of various inflammatory disorders. Phytochemicals that exhibit anti-inflammatory mechanisms that reduce sustained inflammation could be therapeutic candidates for various inflammatory diseases. These phytochemicals act by modulating several main inflammatory signaling pathways, including NF-κB, MAPKs, STAT, and Nrf-2 signaling. Here, we discuss the characteristics of phytochemicals that possess anti-inflammatory activities in various chronic inflammatory diseases and review the molecular signaling pathways altered by these anti-inflammatory phytochemicals, with a focus on transcription factor pathways. Furthermore, to evaluate the phytochemicals as drug candidates, we translate the effective doses of phytochemicals in mice or rat disease models into the human-relevant equivalent and compare the human-relevant equivalent doses of several phytochemicals with current anti-inflammatory drugs doses used in different types of chronic inflammatory diseases.

Astrocytic pyruvate dehydrogenase kinase-2 is involved in hypothalamic inflammation in mouse models of diabetes

Hypothalamic inflammation plays an important role in disrupting feeding behavior and energy homeostasis as well as in the pathogenesis of obesity and diabetes. Here, we show that pyruvate dehydrogenase kinase (PDK)-2 plays a role in hypothalamic inflammation and its sequelae in mouse models of diabetes. Cell type-specific genetic ablation and pharmacological inhibition of PDK2 in hypothalamic astrocytes suggest that hypothalamic astrocytes are involved in the diabetic phenotype. We also show that the PDK2-lactic acid axis plays a regulatory role in the observed metabolic imbalance and hypothalamic inflammation in mouse primary astrocyte and organotypic cultures, through the AMPK signaling pathway and neuropeptidergic circuitry governing feeding behavior. Our findings reveal that PDK2 ablation or inhibition in mouse astrocytes attenuates diabetes-induced hypothalamic inflammation and subsequent alterations in feeding behavior.

Hypothalamic inflammation is involved in the pathogenesis of diabetes. The underlying mechanisms are unclear. Here, the authors show that astrocytic PDK2 ablation or inhibition attenuates hypothalamic inflammation in mouse models of diabetes.

Psychische Komorbiditäten bei Jugendlichen und jungen Erwachsenen mit Typ-1-Diabetes

Jugendliche und junge Erwachsene mit Typ-1-Diabetes sind häufig von komorbiden psychischen Störungen betroffen. Dabei zeigt die Studienlage zur Verbreitung ein heterogenes und inkonsistentes Bild. Diagnose und Behandlung der somatopsychischen Begleiterkrankungen beeinflussen den Behandlungs- und Krankheitsverlauf sowie die Lebensqualität der Betroffenen. Trotzdem wird dies in der klinischen Praxis selten frühzeitig berücksichtigt. Das multizentrische Verbundprojekt COACH verfolgt das Ziel, die Erkennung und Behandlung psychischer Komorbidität für diese Zielgruppe in der bundesweiten Routineversorgung zu optimieren.

The NLRP3 Inflammasome and Its Role in T1DM

The NLRP3 (nucleotide-binding and oligomerization domain-like receptor family pyrin domain-containing 3) inflammasome is a protein complex expressed in cells. It detects danger signals and induces the production of active caspase-1 and the maturation and release of IL (interleukin)-33, IL-18, IL-1β and other cytokines. T1DM (type 1 diabetes mellitus) is defined as a chronic autoimmune disorder characterized by the autoreactive T cell-mediated elimination of insulin-positive pancreatic beta-cells. Although the exact underlying mechanisms are obscure, researchers have proposed that both environmental and genetic factors are involved in the pathogenesis of T1DM. Furthermore, immune responses, including innate and adaptive immunity, play an important role in this process. Recently, the NLRP3 inflammasome, a critical component of innate immunity, was reported to be associated with T1DM. Here, we review the assembly and function of the NLRP3 inflammasome. In addition, the activation and regulatory mechanisms that enhance or attenuate NLRP3 inflammasome activation are discussed. Finally, we focus on the relationship between the NLRP3 inflammasome and T1DM, as well as its potential value for clinical use.

Innate immune stimulation of whole blood reveals IFN-1 hyper-responsiveness in type 1 diabetes

AIMS/HYPOTHESIS

Self-antigen-specific T cell responses drive type 1 diabetes pathogenesis, but alterations in innate immune responses are also critical and not as well understood. Innate immunity in human type 1 diabetes has primarily been assessed via gene-expression analysis of unstimulated peripheral blood mononuclear cells, without the immune activation that could amplify disease-associated signals. Increased responsiveness in each of the two main innate immune pathways, driven by either type 1 IFN (IFN-1) or IL-1, have been detected in type 1 diabetes, but the dominant innate pathway is still unclear. This study aimed to determine the key innate pathway in type 1 diabetes and assess the whole blood immune stimulation assay as a tool to investigate this.

METHODS

The TruCulture whole blood ex vivo stimulation assay, paired with gene expression and cytokine measurements, was used to characterise changes in the stimulated innate immune response in type 1 diabetes. We applied specific cytokine-induced signatures to our data, pre-defined from the same assays measured in a separate cohort of healthy individuals. In addition, NOD mice were stimulated with CpG and monocyte gene expression was measured.

RESULTS

Monocytes from NOD mice showed lower baseline vs diabetes-resistant B6.g7 mice, but higher induced IFN-1-associated gene expression. In human participants, ex vivo whole blood stimulation revealed higher induced IFN-1 responses in type 1 diabetes, as compared with healthy control participants. In contrast, neither the IL-1-induced gene signature nor response to the adaptive immune stimulant Staphylococcal enterotoxin B were significantly altered in type 1 diabetes samples vs healthy control participants. Targeted gene-expression analysis showed that this enhanced IFN response was specific to IFN-1, as IFN-γ-driven responses were not significantly different.

CONCLUSIONS/INTERPRETATION

Our study identifies increased responsiveness to IFN-1 as a feature of both the NOD mouse model of autoimmune diabetes and human established type 1 diabetes. A stimulated IFN-1 gene signature may be a potential biomarker for type 1 diabetes and used to evaluate the effects of therapies targeting this pathway.

DATA AVAILABILITY

Mouse gene expression data are found in the gene expression omnibus (GEO) repository, accession GSE146452 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE146452 ). Nanostring count data from the human experiments were deposited in the GEO repository, accession GSE146338 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE146338 ). Data files and R code for all analyses are available at https://github.com/rodriguesk/T1D_truculture_diabetologia . Graphical abstract.

MD2 activation by direct AGE interaction drives inflammatory diabetic cardiomyopathy

Hyperglycemia activates toll-like receptor 4 (TLR4) to induce inflammation in diabetic cardiomyopathy (DCM). However, the mechanisms of TLR4 activation remain unclear. Here we examine the role of myeloid differentiation 2 (MD2), a co-receptor of TLR4, in high glucose (HG)- and diabetes-induced inflammatory cardiomyopathy. We show increased MD2 in heart tissues of diabetic mice and serum of human diabetic subjects. MD2 deficiency in mice inhibits TLR4 pathway activation, which correlates with reduced myocardial remodeling and improved cardiac function. Mechanistically, we show that HG induces extracellular advanced glycation end products (AGEs), which bind directly to MD2, leading to formation of AGEs-MD2-TLR4 complex and initiation of pro-inflammatory pathways. We further detect elevated AGE-MD2 complexes in heart tissues and serum of diabetic mice and human subjects with DCM. In summary, we uncover a new mechanism of HG-induced inflammatory responses and myocardial injury, in which AGE products directly bind MD2 to drive inflammatory DCM.

The mechanisms underlying cardiac inflammation in diabetic cardiomyopathy are incompletely understood. Here the authors show that advanced glycation end products bind to the TLR4 co-receptor MD2 initiating pro-inflammatory pathways.

Proteomic and Transcriptional Profiles of Human Stem Cell-Derived β Cells Following Enteroviral Challenge

Enteroviral infections are implicated in islet autoimmunity and type 1 diabetes (T1D) pathogenesis. Significant β-cell stress and damage occur with viral infection, leading to cells that are dysfunctional and vulnerable to destruction. Human stem cell-derived β (SC-β) cells are insulin-producing cell clusters that closely resemble native β cells. To better understand the events precipitated by enteroviral infection of β cells, we investigated transcriptional and proteomic changes in SC-β cells challenged with coxsackie B virus (CVB). We confirmed infection by demonstrating that viral protein colocalized with insulin-positive SC-β cells by immunostaining. Transcriptome analysis showed a decrease in insulin gene expression following infection, and combined transcriptional and proteomic analysis revealed activation of innate immune pathways, including type I interferon (IFN), IFN-stimulated genes, nuclear factor-kappa B (NF-κB) and downstream inflammatory cytokines, and major histocompatibility complex (MHC) class I. Finally, insulin release by CVB4-infected SC-β cells was impaired. These transcriptional, proteomic, and functional findings are in agreement with responses in primary human islets infected with CVB ex vivo. Human SC-β cells may serve as a surrogate for primary human islets in virus-induced diabetes models. Because human SC-β cells are more genetically tractable and accessible than primary islets, they may provide a preferred platform for investigating T1D pathogenesis and developing new treatments.

Peroxiredoxin 6 Attenuates Alloxan-Induced Type 1 Diabetes Mellitus in Mice and Cytokine-Induced Cytotoxicity in RIN-m5F Beta Cells

Type 1 diabetes is associated with the destruction of pancreatic beta cells, which is mediated via an autoimmune mechanism and consequent inflammatory processes. In this article, we describe a beneficial effect of peroxiredoxin 6 (PRDX6) in a type 1 diabetes mouse model. The main idea of this study was based on the well-known data that oxidative stress plays an important role in pathogenesis of diabetes and its associated complications. We hypothesised that PRDX6, which is well known for its various biological functions, including antioxidant activity, may provide an antidiabetic effect. It was shown that PRDX6 prevented hyperglycemia, lowered the mortality rate, restored the plasma cytokine profile, reversed the splenic cell apoptosis, and reduced the β cell destruction in Langerhans islets in mice with a severe form of alloxan-induced diabetes. In addition, PRDX6 protected rat insulinoma RIN-m5F β cells, cultured with TNF-α and IL-1β, against the cytokine-induced cytotoxicity and reduced the apoptotic cell death and production of ROS. Signal transduction studies showed that PRDX6 prevented the activation of NF-κB and c-Jun N-terminal kinase signaling cascades in RIN-m5F β cells cultured with cytokines. In conclusion, there is a prospect for therapeutic application of PRDX6 to delay or even prevent β cell apoptosis in type 1 diabetes.

Angiotensin II receptor Neprilysin inhibitor (LCZ696) compared to Valsartan attenuates Hepatotoxicity in STZ-induced hyperglycemic rats

Background and objectives: Although diabetic-induced hepatotoxicity is less common, it can be included in the list of target organ pathologies associated with diabetes. This study aimed to investigate the potential therapeutic role of sacubitril/valsartan (LCZ696) in modulating oxidative and inflammatory injuries and liver fibrosis in STZ-induced hyperglycemic rats in comparison to valsartan alone. Materials and Methods: Following the induction of diabetes using a single dose of streptozotocin (STZ), STZ-induced hyperglycemic animals were administered LCZ696 or valsartan for 6 weeks. Glucose, transaminases, lipid profile, tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin - 6 (IL-6), were estimated using the obtained serum. Oxidative stress biomarkers including thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were measured in the liver homogenate. Additionally, the levels of TNF-α, IL-1β, IL-6, and nuclear factor - kappa β (NF-κB) levels were estimated in hepatic tissue. To assess the general histopathological changes, harvested liver tissue was treated with hematoxylin and eosin or Masson's trichrome staining to detect fibrosis. Results: STZ-induced hyperglycemic rats demonstrated high blood glucose, dyslipidemia, and significant elevation in hepatic transaminases, proinflammatory cytokines, NF-κB, lipid peroxidation, and hepatic fibrosis, with impairment in antioxidant enzymes. In STZ-induced hyperglycemic rats, the administration of LCZ696 ameliorated hyperglycemia, dyslipidemia, improved liver functions, and boosted antioxidants enzymes. Furthermore, LCZ696 therapy attenuated oxidation, inflammation, progression of liver injury, and hepatic fibrosis. LCZ696 was superior to valsartan in reducing AST, hepatic fibrosis, tissue IL-1β, TNF-α and NF-κB. In addition, compared with the valsartan group, LCZ696 significantly increased the antioxidant parameters such as GSH, SOD, CAT and GPx. Conclusion: Collectively, our data demonstrated that LCZ696 could suppress the progression of diabetes-induced hepatic fibrosis, correlating with reduced oxidative stress, hepatic inflammation and NF-κB compared with valsartan alone.

Abnormal Peripheral Neutrophil Transcriptome in Newly Diagnosed Type 2 Diabetes Patients

AIM

There are increasing evidence demonstrating that neutrophil-mediated inflammation plays a role in the etiology of type 2 diabetes. However, the molecular mechanisms by which neutrophils contribute to type 2 diabetes remain largely unknown. The aim of the present work was to identify possible changes in circulating neutrophils to better elucidate neutrophil involvement in human type 2 diabetes.

METHODS

Patients newly diagnosed with type 2 diabetes (n = 5) and age- and sex-matched healthy controls (n = 5) were recruited. Neutrophils were purified from type 2 diabetes patients and controls, and RNA sequencing (RNA-seq) was used for comprehensive transcriptome analysis. Differentially expressed genes (DEGs) were screened, and Gene Ontology (GO) and KEGG pathway enrichment analyses were performed. Real-time polymerase chain reaction (qPCR) was used for validation in external samples of type 2 diabetes patients (n = 8) and healthy controls (n = 8).

RESULTS

Gene expression analysis showed that, compared with neutrophils from healthy controls, there were 1990 upregulated DEGs and 1314 downregulated DEGs in neutrophils from type 2 diabetes patients. GO analysis demonstrated that the DEGs were mainly involved in myeloid leukocyte activation, T cell activation, adaptive immunity, and cytokine production. The top 20 enriched KEGG pathways included the cytokine-cytokine receptor interaction pathway, NF-κB signaling pathway, cell adhesion molecules, and chemokine signaling pathway. Furthermore, qPCR of genes related to neutrophil activation revealed that the expression of SELL, SELP, CXCR1, and S100A8 was significantly increased in neutrophils from type 2 diabetes patients compared with that in neutrophils from controls.

CONCLUSIONS

Our study reveals an abnormal activation of circulating neutrophils at the transcriptome level in type 2 diabetes patients. These findings suggest a potential involvement of neutrophil dysfunction in the pathologic process of type 2 diabetes and provide insight into potential therapeutic targets for type 2 diabetes.

Roles of chitinase 3-like 1 in the development of cancer, neurodegenerative diseases, and inflammatory diseases

Chitinase 3-like 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly increased by various inflammatory and immunological conditions, including rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, and several cancers. However, its physiological and pathophysiological roles in the development of cancer and neurodegenerative and inflammatory diseases remain unclear. Several studies have reported that CHI3L1 promotes cancer proliferation, inflammatory cytokine production, and microglial activation, and that multiple receptors, such as advanced glycation end product, syndecan-1/αVβ3, and IL-13Rα2, are involved. In addition, the pro-inflammatory action of CHI3L1 may be mediated via the protein kinase B and phosphoinositide-3 signaling pathways and responses to various pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 could contribute to a vast array of inflammatory diseases. In this article, we review recent findings regarding the roles of CHI3L1 and suggest therapeutic approaches targeting CHI3L1 in the development of cancers, neurodegenerative diseases, and inflammatory diseases.

Impact of coxsackievirus-B4E2 combined with a single low dose of streptozotocin on pancreas of outbred mice: investigation of viral load, pathology and inflammation

Coxsackieviruses B (CV-B) belong to the EV-B species. CV-B and particularly CV-B4 are thought to be involved in the development of chronic diseases like type 1 diabetes (T1D). The mechanisms of the enteroviral pathogenesis of T1D are not well known, yet. The in vitro studies are rich with information but in vivo infection models are needed to investigate the impact of viruses onto organs. Our objective was to study the impact of CV-B4E2 combined with a single sub-diabetogenic dose of streptozotocin (STZ) on the pancreas of mice. The infection with CV-B4E2 of CD1 outbred mice treated with a sub-diabetogenic dose of STZ induced hyperglycemia and hypoinsulinemia. Along with the chemokine IP-10, viral RNA and infectious particles were detected in the pancreas. The pancreas of these animals was also marked with insulitis and other histological alterations. The model combining STZ and CV-B4E2 opens the door to new perspectives to better understand the interactions between virus and host, and the role of environmental factors capable, like STZ, to predispose the host to the diabetogenic effects of enteroviruses.

Liposomal Curcumin is Better than Curcumin to Alleviate Complications in Experimental Diabetic Mellitus

Curcumin (CC) is known to have anti-inflammatory and anti-oxidative properties and has already been tested for its efficiency in different diseases including diabetes mellitus (DM). New formulations and route administration were designed to obtain products with higher bioavailability. Our study aimed to test the effect of intraperitoneal (i.p.) administration of liposomal curcumin (lCC) as pre-treatment in streptozotocin(STZ)-induced DM in rats on oxidative stress, liver, and pancreatic functional parameters. Forty-two Wistar-Bratislava rats were randomly divided into six groups (seven animals/group): control (no diabetes), control-STZ (STZ-induced DM —60 mg/100g body weight a single dose intraperitoneal administration, and no CC pre-treatment), two groups with DM and CC pre-treatment (1mg/100g bw—STZ + CC1, 2 mg/100g bw—STZ + CC2), and two groups with DM and lCC pre-treatment (1 mg/100g bw—STZ + lCC1, 2 mg/100g bw—STZ + lCC1). Intraperitoneal administration of Curcumin in diabetic rats showed a significant reduction of nitric oxide, malondialdehyde, total oxidative stress, and catalase for both evaluated formulations (CC and lCC) compared to control group (p < 0.005), with higher efficacy of lCC formulation compared to CC solution (p < 0.002, excepting catalase for STZ + CC2vs. STZ + lCC1when p = 0.0845). The CC and lCC showed hepatoprotective and hypoglycemic effects, a decrease in oxidative stress and improvement in anti-oxidative capacity status against STZ-induced DM in rats (p < 0.002). The lCC also proved better efficacy on MMP-2, and -9 plasma levels as compared to CC (p < 0.003, excepting STZ + CC2 vs. STZ + lCC1 comparison with p = 0.0553). The lCC demonstrated significantly better efficacy as compared to curcumin solution on all serum levels of the investigated markers, sustaining its possible use as adjuvant therapy in DM.

Cell type-specific immune phenotypes predict loss of insulin secretion in new-onset type 1 diabetes

The rate of decline in insulin secretion after diagnosis with type 1 diabetes (T1D) varies substantially among individuals and with age at diagnosis, but the mechanism(s) behind this heterogeneity are not well understood. We investigated the loss of pancreatic β cell function in new-onset T1D subjects using unbiased whole blood RNA-seq and verified key findings by targeted cell count measurements. We found that patients who lost insulin secretion more rapidly had immune phenotypes ("immunotypes") characterized by higher levels of B cells and lower levels of neutrophils, especially neutrophils expressing primary granule genes. The B cell and neutrophil immunotypes showed strong age dependence, with B cell levels in particular predicting rate of progression in young subjects only. This age relationship suggested that therapy targeting B cells in T1D would be most effective in young subjects with high pretreatment B cell levels, a prediction which was supported by data from a clinical trial of rituximab in new-onset subjects. These findings demonstrate a link between age-related immunotypes and disease outcome in new-onset T1D. Furthermore, our data suggest that greater success could be achieved by targeted use of immunomodulatory therapy in specific T1D populations defined by age and immune characteristics.

Genetic immune and inflammatory markers associated with diabetes in solid organ transplant recipients

New-onset diabetes mellitus after transplantation (NODAT) is a complication following solid organ transplantation (SOT) and may be related to immune or inflammatory responses. We investigated whether single nucleotide polymorphisms (SNPs) within 158 immune- or inflammation-related genes contribute to NODAT in SOT recipients. The association between 263 SNPs and NODAT was investigated in a discovery sample of SOT recipients from the Swiss Transplant Cohort Study (STCS, n₁  = 696). Positive results were tested in a first STCS replication sample (n₂  = 489) and SNPs remaining significant after multiple test corrections were tested in a second SOT replication sample (n₃  = 156). Associations with diabetic traits were further tested in several large general population-based samples (n > 480 000). Only SP110 rs2114592C>T remained associated with NODAT in the STCS replication sample. Carriers of rs2114592-TT had 9.9 times (95% confidence interval [CI]: 3.22-30.5, P = .00006) higher risk for NODAT in the combined STCS samples (n = 1184). rs2114592C>T was further associated with NODAT in the second SOT sample (odds ratio: 4.8, 95% CI: 1.55-14.6, P = .006). On the other hand, SP110 rs2114592C>T was not associated with diabetic traits in population-based samples, suggesting a specific gene-environment interaction, possibly due to the use of specific medications (ie, immunosuppressants) in transplant patients and/or to the illness that may unmask the gene effect.

Dual Role of PTPN22 but Not NLRP3 Inflammasome Polymorphisms in Type 1 Diabetes and Celiac Disease in Children

Genetic polymorphisms in genes coding for inflammasome components nucleotide-binding oligomerization domain leucine rich repeat and pyrin domain-containing protein 3 (NLRP3) and caspase recruitment domain-containing protein 8 (CARD8) have been associated with autoinflammatory and autoimmune diseases. On the other hand several studies suggested that NLRP3 inflammasome contributes to maintenance of gastrointestinal immune homeostasis and that activation of NLRP3 is regulated by protein tyrosine phosphatase non-receptor 22 (PTPN22). PTPN22 polymorphism was implicated in the risk for various autoimmune diseases including type 1 diabetes (T1D) but not for celiac disease (CD). The aim of our study was to evaluate the role of inflammasome related polymorphisms in subjects with either T1D or CD as well as in subjects affected by both diseases. We examined PTPN22 rs2476601 (p.Arg620Trp), NLRP3 rs35829419 (p.Gln705Lys), and CARD8 rs2043211 (p.Cys10Ter) in 66 subjects with coexisting T1D and CD, 65 subjects with T1D who did not develop CD, 67 subjects diagnosed only with CD and 127 healthy unrelated Slovenian individuals. All results were adjusted for clinical characteristic and human leukocyte antigen (HLA) risk. PTPN22 rs2476601 allele was significantly more frequent among subjects with T1D (P_adj = 0.001) and less frequent in subjects with CD (P_adj = 0.039) when compared to controls. In patients with coexisting T1D and CD this variant was significantly less frequent compared to T1D group (P_adj = 0.010). Protective effect on CD development in individuals with T1D was observed only within the low risk HLA group. On the other hand, we found no association of NLRP3 rs35829419 and CARD8 rs2043211 with the development of T1D, CD or both diseases together. In conclusion PTPN22 rs2476601polymorphism was significantly associated with the risk of developing T1D in Slovenian population, while no associations of proinflammatory NLRP3 and CARD8 polymorphisms with T1D and CD were observed. Interestingly, the same PTPN22 variant protected from CD. We hypothesize that this effect may be mediated through the NLRP3 inflammasome activation.

Innate immune activity as a predictor of persistent insulin secretion and association with responsiveness to CTLA4-Ig treatment in recent-onset type 1 diabetes

AIMS/HYPOTHESIS

The study aimed to determine whether discrete subtypes of type 1 diabetes exist, based on immunoregulatory profiles at clinical onset, as this has significant implications for disease treatment and prevention as well as the design and analysis of clinical trials.

METHODS

Using a plasma-based transcriptional bioassay and a gene-ontology-based scoring algorithm, we examined local participants from the Children's Hospital of Wisconsin and conducted an ancillary analysis of TrialNet CTLA4-Ig trial (TN-09) participants.

RESULTS

The inflammatory/regulatory balance measured during the post-onset period was highly variable. Notably, a significant inverse relationship was identified between baseline innate inflammatory activity and stimulated C-peptide AUC measured at 3, 6, 12, 18 and 24 months post onset among placebo-treated individuals (p ≤ 0.015). Further, duration of persistent insulin secretion was negatively related to baseline inflammation (p ≤ 0.012) and positively associated with baseline abundance of circulating activated regulatory T cells (CD4⁺/CD45RA^-/FOXP3^high; p = 0.016). Based on these findings, data from participants treated with CTLA4-Ig were stratified by inflammatory activity at onset; in this way, we identified pathways and transcripts consistent with inhibition of T cell activation and enhanced immunoregulation. Variance among baseline plasma-induced signatures of TN-09 participants was further examined with weighted gene co-expression network analysis and related to clinical metrics. Four age-independent subgroups were identified that differed in terms of baseline innate inflammatory/regulatory bias, rate of C-peptide decline and response to CTLA4-Ig treatment.

CONCLUSIONS/INTERPRETATION

These data support the existence of multiple type 1 diabetes subtypes characterised by varying levels of baseline innate inflammation that are associated with the rate of C-peptide decline.

DATA AVAILABILITY

Gene expression data files are publicly available through the National Center for Biotechnology Information Gene Expression Omnibus (accession number GSE102234).

Interleukin-1 Blockade: An Update on Emerging Indications

Interleukin (IL)-1 is a pro-inflammatory cytokine that induces local and systemic inflammation aimed to eliminate microorganisms and tissue damage. However, an increasing number of clinical conditions have been identified in which IL-1 production is considered inappropriate and IL-1 is part of the disease etiology. In autoinflammatory diseases, gout, Schnitzler's syndrome, and adult-onset Still's disease, high levels of inappropriate IL-1 production have been shown to be a key process in the etiology of the disease. In these conditions, blocking IL-1 has proven very effective in clinical studies. In other diseases, IL-1 has shown to be present in disease process but is not the central driving force of inflammation. In these conditions, including type 1 and 2 diabetes mellitus, acute coronary syndrome, amyotrophic lateral sclerosis, and several neoplastic diseases, the benefits of IL-1 blockade are minimal or absent.

Restoration of the type I IFN-IL-1 balance through targeted blockade of PTGER4 inhibits autoimmunity in NOD mice

Type I IFN (IFN-I) dysregulation contributes to type 1 diabetes (T1D) development, and although increased IFN-I signals are pathogenic at the initiation of autoimmune diabetes, IFN-I dysregulation at later pathogenic stages more relevant for therapeutic intervention is not well understood. We discovered that 5 key antigen-presenting cell subsets from adult prediabetic NOD mice have reduced responsiveness to IFN-I that is dominated by a decrease in the tonic-sensitive subset of IFN-I response genes. Blockade of IFNAR1 in prediabetic NOD mice accelerated diabetes and increased Th1 responses. Therefore, IFN-I responses shift from pathogenic to protective as autoimmunity progresses, consistent with chronic IFN-I exposure. In contrast, IL-1-associated inflammatory pathways were elevated in prediabetic mice. These changes correlated with human T1D onset-associated gene expression. Prostaglandin E2 (PGE2) and prostaglandin receptor 4 (PTGER4), a receptor for PGE2 that mediates both inflammatory and regulatory eicosanoid signaling, were higher in NOD mice and drive innate immune dysregulation. Treating prediabetic NOD mice with a PTGER4 antagonist restored IFNAR signaling, decreased IL-1 signaling, and decreased infiltration of leukocytes into the islets. Therefore, innate cytokine alterations contribute to both T1D-associated inflammation and autoimmune pathogenesis. Modulating innate immune balance via signals such as PTGER4 may contribute to treatments for autoimmunity.

Modulation of the diet and gastrointestinal microbiota normalizes systemic inflammation and β-cell chemokine expression associated with autoimmune diabetes susceptibility

Environmental changes associated with modern lifestyles may underlie the rising incidence of Type 1 diabetes (T1D). Our previous studies of T1D families and the BioBreeding (BB) rat model have identified a peripheral inflammatory state that is associated with diabetes susceptibility, consistent with pattern recognition receptor ligation, but is independent of disease progression. Here, compared to control strains, islets of spontaneously diabetic BB DRlyp/lyp and diabetes inducible BB DR+/+ weanlings provided a standard cereal diet expressed a robust proinflammatory transcriptional program consistent with microbial antigen exposure that included numerous cytokines/chemokines. The dependence of this phenotype on diet and gastrointestinal microbiota was investigated by transitioning DR+/+ weanlings to a gluten-free hydrolyzed casein diet (HCD) or treating them with antibiotics to alter/reduce pattern recognition receptor ligand exposure. Bacterial 16S rRNA gene sequencing revealed that these treatments altered the ileal and cecal microbiota, increasing the Firmicutes:Bacteriodetes ratio and the relative abundances of lactobacilli and butyrate producing taxa. While these conditions did not normalize the inherent hyper-responsiveness of DR+/+ rat leukocytes to ex vivo TLR stimulation, they normalized plasma cytokine levels, plasma TLR4 activity levels, the proinflammatory islet transcriptome, and β-cell chemokine expression. In lymphopenic DRlyp/lyp rats, HCD reduced T1D incidence, and the introduction of gluten to this diet induced islet chemokine expression and abrogated protection from diabetes. Overall, these studies link BB rat islet-level immunocyte recruiting potential, as measured by β-cell chemokine expression, to a genetically controlled immune hyper-responsiveness and innate inflammatory state that can be modulated by diet and the intestinal microbiota.

Proteomic Landscape of Patient-Derived CD4+ T Cells in Recent-Onset Type 1 Diabetes

The pathophysiology underlying the autoimmune disease type 1 diabetes (T1D) is poorly understood. Obtaining an accurate proteomic profile of the T helper cell population is essential for understanding the pathogenesis of T1D. Here, we performed in-depth proteomic profiling of peripheral CD4+ T cells in a pediatric cohort to identify cellular signatures associated with the onset of T1D. Using only 250 000 CD4+ T cells per patient, isolated from biobanked PBMC samples, we identified nearly 6000 proteins using deep-proteome profiling with LC-MS/MS data-independent acquisition. Our analysis revealed an inflammatory signature in patients with T1D; this signature is characterized by circulating mediators of neutrophils, platelets, and the complement system. This signature likely reflects the inflammatory extracellular milieu, which suggests that activation of the innate immune system plays an important role in disease onset. Our results emphasize the potential value of using high-resolution LC-MS/MS to investigate limited quantities of biobanked samples to identify disease-relevant proteomic patterns. Proteomic profiles of 114 individuals have been deposited in a comprehensive portable repository serving as a unique resource for CD4+ T cell expression in the context of both health and T1D disease.

Evidence-based update on rosacea comorbidities and their common physiologic pathways

Rosacea is a common chronic inflammatory disease affecting the facial skin whose etiology and pathophysiology are the subject of much investigation. Risk factors include genetic and environmental elements that may predispose individuals to localized inflammation and abnormal neurovascular responses to stimuli. Recent studies have introduced an array of systemic rosacea comorbidities, such as inflammatory bowel disease and neurologic conditions, that can be challenging to synthesize. We critically review the current data behind reported rosacea comorbidities and identify and highlight underrecognized physiologic mediators shared among rosacea and associated comorbidities. This information may be helpful in addressing patient questions about potential systemic implications of rosacea and can serve as a candidate platform for future research to understand rosacea and improve treatments.

Oral delivery of staphylococcal nuclease by Lactococcus lactis prevents type 1 diabetes mellitus in NOD mice

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by the self-destruction of insulin-producing β cells. Recently, studies have revealed that neutrophils contribute to the early pathological injury to the pancreas, predominantly via the formation of neutrophil extracellular traps (NETs). To determine whether early intervention targeting NETs with staphylococcal nuclease (SNase) can delay the onset of T1DM, non-obese diabetic (NOD) mice were orally administered recombinant Lactococcus lactis (L. lactis) expressing SNase. The results showed that NETs were effectively disrupted by SNase both in vivo and in vitro, leading to a significant decrease in neutrophil-derived circulating free DNA (cf-DNA/NETs), neutrophil elastase (NE), and protease 3 (PR3) in the serum compared with the controls. In addition, SNase effectively regulated the blood glucose levels of NOD mice, and the onset of diabetes was postponed with reduced mortality and morbidity. Recombinant L. lactis also ameliorated inflammation in NOD mice, as evidenced by the remarkable increase in IL-4 and reductions in TNF-α and CRP. Moreover, HE staining results showed that L. lactis expressing SNase exerted protective effects on pancreatic islets and relieved inflammation of the small intestine in NOD mice. Hence, the present study indicates that the oral delivery of SNase by L. lactis can effectively prevent T1DM, ameliorate inflammation, and contribute to immunomodulatory balance in NOD mice.

MicroRNA-146a-5p Mediates High Glucose-Induced Endothelial Inflammation via Targeting Interleukin-1 Receptor-Associated Kinase 1 Expression

Background and Aims: Interleukin-1 receptor-associated kinase-1 (IRAK-1) is critical for mediating toll-like receptor and interleukin-1 receptor signaling. In this study, we have examined whether IRAK-1 expression is altered in high glucose (HG)-stimulated human aortic endothelial cells (HAECs), and whether microRNAs (miRs) target IRAK-1 to regulate HG-induced endothelial inflammation.

Methods: HAECs were treated with HG for 24 and 48 h. Real-time PCR, Western blot, monocyte adhesion assay, bioinformatics analysis, TaqMan® arrays, microRNA mimic or inhibitor transfection, luciferase reporter assay and siRNA IRAK-1 transfection were performed. The aortic tissues from db/db type 2 diabetic mice were examined by immunohistochemistry staining.

Results: HG time-dependently increased IRAK-1 mRNA and protein levels in HAECs, and was associated with increased VCAM-1/ICAM-1 gene expression and monocyte adhesion. Bioinformatic analysis, TaqMan® arrays, and real-time PCR were used to confirm that miR-146a-5p, miR-339-5p, and miR-874-3p were significantly downregulated in HG-stimulated HAECs, suggesting impaired feedback restraints on HG-induced endothelial inflammation via IRAK-1. However, only miR-146a-5p mimic transfection reduced the HG-induced upregulation of IRAK-1 expression, VCAM-1/ICAM-1 expression, and monocyte adhesion. Additionally, IRAK-1 depletion reduced HG-induced VCAM-1/ICAM-1 gene expression, and monocyte adhesion, indicating that HG-induced endothelial inflammation was mediated partially through IRAK-1. In vivo, intravenous injections of miR-146a-5p mimic prevented endothelial IRAK-1 and ICAM-1 expression in db/db mice.

Conclusion: These results suggest that miR-146a-5p is involved in the regulation of HG-induced endothelial inflammation via modulation of IRAK-1; indicating that miR-146a-5p may be a novel target for the treatment of diabetic vascular complications.