Neutrophils in type 1 diabetes

Viral infection and host immune response in diabetes

Diabetes, a chronic metabolic disorder disrupting blood sugar regulation, has emerged as a prominent silent pandemic. Uncontrolled diabetes predisposes an individual to develop fatal complications like cardiovascular disorders, kidney damage, and neuropathies and aggravates the severity of treatable infections. Escalating cases of Type 1 and Type 2 diabetes correlate with a global upswing in diabetes-linked mortality. As a growing global concern with limited preventive interventions, diabetes necessitates extensive research to mitigate its healthcare burden and assist ailing patients. An altered immune system exacerbated by chronic hyperinflammation heightens the susceptibility of diabetic individuals to microbial infections, including notable viruses like SARS-CoV-2, dengue, and influenza. Given such a scenario, we scrutinized the literature and compiled molecular pathways and signaling cascades related to immune compartments in diabetics that escalate the severity associated with the above-mentioned viral infections in them as compared to healthy individuals. The pathogenesis of these viral infections that trigger diabetes compromises both innate and adaptive immune functions and pre-existing diabetes also leads to heightened disease severity. Lastly, this review succinctly outlines available treatments for diabetics, which may hold promise as preventive or supportive measures to effectively combat these viral infections in the former.

A Plasma miR-193b-365 Signature Combined With Age and Glycemic Status Predicts Response to Lactococcus lactis-Based Antigen-Specific Immunotherapy in New-Onset Type 1 Diabetes

Immunomodulation combined with antigen therapy holds great promise to arrest autoimmune type 1 diabetes, but clinical translation is hampered by a lack of prognostic biomarkers. Low-dose anti-CD3 plus Lactococcus lactis bacteria secreting proinsulin and IL-10 reversed new-onset disease in nonobese diabetic (NOD) mice, yet some mice were resistant to the therapy. Using miRNA profiling, six miRNAs (i.e., miR-34a-5p, miR-125a-3p, miR-193b-3p, miR-328, miR-365-3p, and miR-671-3p) were identified as differentially expressed in plasma of responder versus nonresponder mice before study entry. After validation and stratification in an independent cohort, plasma miR-193b-3p and miR-365-3p, combined with age and glycemic status at study entry, had the best power to predict, with high sensitivity and specificity, poor response to the therapy. These miRNAs were highly abundant in pancreas-infiltrating neutrophils and basophils with a proinflammatory and activated phenotype. Here, a set of miRNAs and disease-associated parameters are presented as a predictive signature for the L. lactis-based immunotherapy outcome in new-onset type 1 diabetes, hence allowing targeted recruitment of trial participants and accelerated trial execution.

ARTICLE HIGHLIGHTS

Low-dose anti-CD3 combined with oral gavage of genetically modified Lactococcus lactis bacteria secreting human proinsulin and IL-10 holds great promise to arrest autoimmune type 1 diabetes, but the absence of biomarkers predicting therapeutic success hampers clinical translation. A set of cell-free circulation miRNAs together with age and glycemia at baseline predicts a poor response after L. lactis-based immunotherapy in nonobese mice with new-onset diabetes. Pancreas-infiltrating neutrophils and basophils are identified as potential cellular sources of discovered miRNAs. The prognostic signature could guide targeted recruitment of patients with newly diagnosed type 1 diabetes in clinical trials with the L. lactis-based immunotherapy.

Post hoc analysis of a randomized, double-blind, prospective trial evaluating a CXCR1/2 inhibitor in new-onset type 1 diabetes: endo-metabolic features at baseline identify a subgroup of responders

Aim

In a recent randomized, multicenter trial (NCT02814838) a short-term anti-inflammatory treatment with ladarixin (LDX; an inhibitor of the CXCR1/2 chemokine receptors) did not show benefit on preserving residual beta cell function in new-onset type 1 diabetes. We present a post hoc analysis of trial patients in the predefined subgroup analysis developed according to baseline daily insulin requirement (DIR) tertiles.

Method

A double-blind, randomized (2:1), placebo-controlled study was conducted in 45 men and 31 women (aged 18-46 years) within 100 days of the first insulin administration. Patients received LDX (400 mg twice daily) for three cycles of 14 days on/14 days off, or placebo. The primary endpoint was the area under the curve for C-peptide [AUC (0-120 min)] in response to a 2-h mixed meal tolerance test (MMTT) at week 13 ± 1. Seventy-five patients completed the week 13 MMTT and were divided into three groups according to the DIR tertiles: lower, ≤ 0.23U/kg/die (n = 25); middle, 0.24-0.40 U/kg/die (n = 24); upper, ≥ 0.41 U/kg/die (n = 26).

Results

When considering the patients in the upper tertile (HIGH-DIR), C-peptide AUC (0-120 min) at 13 weeks was higher in the LDX group (n = 16) than in the placebo (n = 10) group [difference: 0.72 nmol/L (95% CI 0.9-1.34), p = 0.027]. This difference reduced over time (0.71 nmol/L at 26 weeks, p = 0.04; 0.42 nmol/L at 52 weeks, p = 0.29), while it has never been significant at any time in patients in the lower and/or middle tertile (LOW-DIR). We characterized at baseline the HIGH-DIR and found that endo-metabolic (HOMA-B, adiponectin, and glucagon-to-C-peptide ratio) and immunologic (chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemoattractant protein 1 (MCP1) and Vascular Endothelial Growth Factor (VEGF)) features distinguished this group from LOW-DIR.

Conclusion

While LDX did not prevent the progressive loss of beta-cell function in the majority of treated subjects, the post hoc analysis suggests that it could work in subjects with HIGH-DIR at baseline. As we found differences in endo-metabolic and immunologic parameters within this subgroup, this generates the hypothesis that the interactions between host factors and drug action can contribute to its efficacy. Further research is needed to evaluate this hypothesis.

Neutrophil (dys)function due to altered immuno-metabolic axis in type 2 diabetes: implications in combating infections

Metabolic and inflammatory pathways are highly interdependent, and both systems are dysregulated in Type 2 diabetes (T2D). T2D is associated with pre-activated inflammatory signaling networks, aberrant cytokine production and increased acute phase reactants which leads to a pro-inflammatory 'feed forward loop'. Nutrient 'excess' conditions in T2D with hyperglycemia, elevated lipids and branched-chain amino acids significantly alter the functions of immune cells including neutrophils. Neutrophils are metabolically active cells and utilizes energy from glycolysis, stored glycogen and β-oxidation while depending on the pentose phosphate pathway for NADPH for performing effector functions such as chemotaxis, phagocytosis and forming extracellular traps. Metabolic changes in T2D result in constitutive activation and impeded acquisition of effector or regulatory activities of neutrophils and render T2D subjects for recurrent infections. Increased flux through the polyol and hexosamine pathways, elevated production of advanced glycation end products (AGEs), and activation of protein kinase C isoforms lead to (a) an enhancement in superoxide generation; (b) the stimulation of inflammatory pathways and subsequently to (c) abnormal host responses. Neutrophil dysfunction diminishes the effectiveness of wound healing, successful tissue regeneration and immune surveillance against offending pathogens. Hence, Metabolic reprogramming in neutrophils determines frequency, severity and duration of infections in T2D. The present review discusses the influence of the altered immuno-metabolic axis on neutrophil dysfunction along with challenges and therapeutic opportunities for clinical management of T2D-associated infections.

Characteristic gene prognostic model of type 1 diabetes mellitus via machine learning strategy

The present study was designed to detect possible biomarkers associated with Type 1 diabetes mellitus (T1DM) incidence in an effort to develop novel treatments for this condition. Three mRNA expression datasets of peripheral blood mononuclear cells (PBMCs) were obtained from the GEO database. Differentially expressed genes (DEGs) between T1DM patients and healthy controls were identified by Limma package in R, and using the DEGs to conduct GO and DO pathway enrichment. The LASSO-SVM were used to screen the hub genes. We performed immune correlation analysis of hub genes and established a T1DM prognosis model. CIBERSORT algorithm was used to identify the different immune cells in distribution between T1DM and normal samples. The correlation of the hub genes and immune cells was analyzed by Spearman. ROC curves were used to assess the diagnostic value of genes in T1DM. A total of 60 immune related DEGs were obtained from the T1DM and normal samples. Then, DEGs were further screened to obtain 3 hub genes, ANP32A-IT1, ESCO2 and NBPF1. CIBERSORT analysis revealed the percentage of immune cells in each sample, indicating that there was significant difference in monocytes, T cells CD8+, gamma delta T cells, naive CD4+ T cells and activated memory CD4+ T cells between T1DM and normal samples. The area under curve (AUC) of ESCO2, ANP32A-IT1 and NBPF1 were all greater than 0.8, indicating that these three genes have high diagnostic value for T1DM. Together, the findings of these bioinformatics analyses thus identified key hub genes associated with T1DM development.

Role of hematological parameters in pathogenesis of diabetes mellitus: A review of the literature

Diabetes mellitus (DM) is characterized by hyperglycemia and abnormalities in insulin secretion and activity. There are numerous hematological parameters; however, this review article only focuses on red blood cells, hemoglobin, hematocrit, red blood cell indices, platelet count, white blood cells, lymphocytes, neutrophils, monocytes, eosinophils, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio, which play an essential role in the pathogenesis of DM. Also, this review article aims to report the relationship between these hematological parameters and the development of DM. In con-clusion, this article shows that increased levels of platelets, red blood cells, hematocrit, lymphocytes, eosinophils, neutrophils, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio and decreased levels of hemoglobin are involved in the pathogenesis of DM. However, the role of basophils in DM is unknown yet.

Polymorphonuclear phenotypical expression of CD18, at baseline and after in vitro activation, in several clinical disorders: Revision of our case series

BACKGROUND

In relation to the different and important roles of the beta2 integrins, we have revisited the expression of polymorphonuclear leukocyte CD18 in several clinical disorders, at baseline and after in vitro activation.

SUBJECTS

we have examined subjects with type 1 diabetes mellitus, vascular atherosclerotic disease, type 2 diabetes mellitus without and with macrovascular complications, chronic renal failure on conservative treatment, essential hypertension, deep venous thrombosis, acute ischemic stroke and subjects with venous leg ulcers.

METHODS

unfractioned leukocyte suspension was prepared according to the Mikita's method, while the leukocyte were separated into mononuclear and polymorphonuclear cells with a Ficoll-Hypaque medium. Using specific monoclonal antibody, the CD18 expression was evaluated with cytofluorimetric analysis, using FACScan (Becton Dickinson) be Cellquest software; the activation in vitro with PMA was effected according to modified Yasui and Masuda methods.

RESULTS

in type 1 diabetes mellitus, at baseline CD18 is under expressed in comparison with normal control, and not changes after PMA activation were observed; in subjects with vascular atherosclerotic disease, in type 2 diabetes mellitus CD18 is over expressed at baseline but does not vary after activation; in subjects with chronic renal failure, essential hypertension and in subjects with acute ischemic stroke the CD18 up-regulate at baseline compared to normal control, and it increases further after activation; in subjects with deep venous thrombosis the CD18 expression is not different from control group at baseline, but it increases after activation; finally, in subjects with venous leg ulcers the CD18 is normally expressed at baseline, and it does not change after PMA activation.

CONCLUSIONS

in the different clinical disorders, the trend of this integrin subunit provides some specific information, useful to select the best therapeutic strategy in clinical practice.

Leukocyte metabolism in obese type 2 diabetic individuals associated with COVID-19 severity

Recent studies show that the metabolic characteristics of different leukocytes, such as, lymphocytes, neutrophils, and macrophages, undergo changes both in the face of infection with SARS-CoV-2 and in obesity and type 2 diabetes mellitus (DM2) condition. Thus, the objective of this review is to establish a correlation between the metabolic changes caused in leukocytes in DM2 and obesity that may favor a worse prognosis during SARS-Cov-2 infection. Chronic inflammation and hyperglycemia, specific and usual characteristics of obesity and DM2, contributes for the SARS-CoV-2 replication and metabolic disturbances in different leukocytes, favoring the proinflammatory response of these cells. Thus, obesity and DM2 are important risk factors for pro-inflammatory response and metabolic dysregulation that can favor the occurrence of the cytokine storm, implicated in the severity and high mortality risk of the COVID-19 in these patients.

NEUTROPHIL ACTIVITIES IN ADOLESCENTS WITH TYPE I DIABETES MELLITUS DEPENDING ON PERIODONTAL STATE

OBJECTIVE

The aim: To estimate the neutrophil activities in adolescents with type 1 diabetes mellitus (T1DM) depending on periodontal state.

PATIENTS AND METHODS

Materials and methods: A total of 93 individuals aged 12-16 years, including 62 T1DM patients and 31 healthy (H) controls, were included. Both groups were categorized into subgroups depending on their periodontal state. Phagocytic activity of neutrophils (PAN) the index of neutrophil activation (INA), and the percent of formazan-active neutrophils were evaluated using the spontaneous and the induced nitroblue tetrazolium (sNBT and iNBT) tests into oral rinses.

RESULTS

Results: PAN was significantly higher in the healthy (H) controls with gingivitis compared with the individuals with gingival health (p < 0.0001). This parameter decreased significantly in the T1DM subjects, especially with periodontitis, compared with the H controls (p < 0.0001). The percent of formazan-active neutrophils and INA in the sNBT test increased in the T1DM patients with gingival health and continued to raise as periodontal state of adolescents with T1DM worsened (p<0.0001). The parameters of the iNBT test in the T1DM adolescents decreased with the periodontal disease development (p < 0.0001) that may demonstrate that superoxide production exhausts in diabetes, especially associated with periodontal disease.

CONCLUSION

Conclusions: The sNBT test in studied adolescents showed that both periodontal disease and T1DM increase the rate of activated neutrophils (p<0,05).

Identification of diagnostic gene biomarkers and immune infiltration in patients with diabetic kidney disease using machine learning strategies and bioinformatic analysis

Objective

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease and end-stage renal disease worldwide. Early diagnosis is critical to prevent its progression. The aim of this study was to identify potential diagnostic biomarkers for DKD, illustrate the biological processes related to the biomarkers and investigate the relationship between them and immune cell infiltration.

Materials and methods

Gene expression profiles (GSE30528, GSE96804, and GSE99339) for samples obtained from DKD and controls were downloaded from the Gene Expression Omnibus database as a training set, and the gene expression profiles (GSE47185 and GSE30122) were downloaded as a validation set. Differentially expressed genes (DEGs) were identified using the training set, and functional correlation analyses were performed. The least absolute shrinkage and selection operator (LASSO), support vector machine-recursive feature elimination (SVM-RFE), and random forests (RF) were performed to identify potential diagnostic biomarkers. To evaluate the diagnostic efficacy of these potential biomarkers, receiver operating characteristic (ROC) curves were plotted separately for the training and validation sets, and immunohistochemical (IHC) staining for biomarkers was performed in the DKD and control kidney tissues. In addition, the CIBERSORT, XCELL and TIMER algorithms were employed to assess the infiltration of immune cells in DKD, and the relationships between the biomarkers and infiltrating immune cells were also investigated.

Results

A total of 95 DEGs were identified. Using three machine learning algorithms, DUSP1 and PRKAR2B were identified as potential biomarker genes for the diagnosis of DKD. The diagnostic efficacy of DUSP1 and PRKAR2B was assessed using the areas under the curves in the ROC analysis of the training set (0.945 and 0.932, respectively) and validation set (0.789 and 0.709, respectively). IHC staining suggested that the expression levels of DUSP1 and PRKAR2B were significantly lower in DKD patients compared to normal. Immune cell infiltration analysis showed that B memory cells, gamma delta T cells, macrophages, and neutrophils may be involved in the development of DKD. Furthermore, both of the candidate genes are associated with these immune cell subtypes to varying extents.

Conclusion

DUSP1 and PRKAR2B are potential diagnostic markers of DKD, and they are closely associated with immune cell infiltration.

Ladarixin, an inhibitor of the interleukin-8 receptors CXCR1 and CXCR2, in new-onset type 1 diabetes: A multicentre, randomized, double-blind, placebo-controlled trial

AIM

To evaluate the ability of ladarixin (LDX, 400 mg twice-daily for three cycles of 14 days on/14 days off), an inhibitor of the CXCR1/2 chemokine receptors, to maintain C-peptide production in adult patients with newly diagnosed type 1 diabetes.

MATERIALS AND METHODS

A double-blind, randomized (2:1), placebo-controlled study was conducted in 45 males and 31 females (aged 18-46 years) within 100 days of the first insulin administration. The primary endpoint was the area under the curve (AUC) for C-peptide in response to a 2-hour mixed meal tolerance test (AUC_{[0-120 min]} ) at week 13 ± 1. Secondary endpoints included C-peptide AUC_{(15-120 min)} , HbA1c, daily insulin requirement, severe hypoglycaemic events (SHE), the proportion of subjects achieving HbA1c less than 7.0% without SHE and maintaining a residual beta cell function. Follow-up assessments were scheduled at weeks 13 ± 1, 26 ± 2 and 52 ± 2.

RESULTS

In total, 26/26 (100%, placebo) and 49/50 (98%, LDX) patients completed week 13. The mean change from baseline to week 13 in C-peptide AUC_{(0-120 min)} was -0.144 ± 0.449 nmol/L with placebo and 0.003 ± .322 nmol/L with LDX. The difference was not significant (0.149 nmol/L, 95% CI -0.04 to 0.33; P = .122). At week 26, the proportion of patients with HbA1c less than 7.0% without SHE was transiently higher in the LDX group (81% vs. 54%, P = .024). Otherwise, no significant secondary endpoint differences were noted. Transient metabolic benefit was seen at week 26 in favour of the LDX group in the prespecified subpopulation with fasting C-peptide less than the median value at screening.

CONCLUSIONS

In newly diagnosed patients with type 1 diabetes, short-term LDX treatment had no appreciable effect on preserving residual beta cell function.

Macrophages and neutrophils are necessary for ER stress-induced β cell loss

Persistent endoplasmic reticulum (ER) stress induces islet inflammation and β cell loss. How islet inflammation contributes to β cell loss remains uncertain. We have reported previously that chronic overnutrition-induced ER stress in β cells causes Ripk3-mediated islet inflammation, macrophage recruitment, and a reduction of β cell numbers in a zebrafish model. We show here that β cell loss results from the intricate communications among β cells, macrophages, and neutrophils. Macrophage-derived Tnfa induces cxcl8a in β cells. Cxcl8a, in turn, attracts neutrophils to macrophage-contacted “hotspots” where β cell loss occurs. We also show potentiation of chemokine expression in stressed mammalian β cells by macrophage-derived TNFA. In Akita and db/db mice, there is an increase in CXCL15-positive β cells and intra-islet neutrophils. Blocking neutrophil recruitment in Akita mice preserves β cell mass and slows diabetes progression. These results reveal an important role of neutrophils in persistent ER stress-induced β cell loss.

Yang et al. show a pivotal role of communications among β cells, macrophages, and neutrophils in chronic overnutrition-induced loss of pancreatic β cells in a diabetes-prone zebrafish model.

Isolated and Combined Effect of Age and Gender on Neutrophil-Lymphocyte Ratio in the Hyperglycemic Saudi Population

Inflammation is pivotal to the pathogenesis of diabetes mellitus (DM), but pathological alterations of the neutrophil−lymphocyte ratio (NLR), an emerging inflammatory index in DM management, remains understudied. The aim of this study is to examine the relationship between NLR and glycemic control in the Saudi population. Gender, age, WBC count, and fasting blood glucose (FBG) were obtained from Al-Borg Medical Laboratories for 14,205 subjects. Means, prevalence, risk measures, and the diagnostic accuracy of elevated NLR and hyperglycemia (HG) were evaluated. Subjects with elevated NLR (>3) had significantly higher FBG (105.10 ± 0.33 vs. 114.0 ± 2.81) and NLR was significantly elevated in impaired fasting glycemia (IFG; 1.21 ± 0.01 vs. 1.25 ± 0.01) and HG (1.21 ± 0.01 vs. 1.39 ± 0.02). Elevations of NLR in HG but not in IFG persisted across all age groups except young males and elderly females. The prevalence of elevated NLR in hyperglycemic subjects was 4.12% compared to 2.16% in subjects with normal FBG. HG was more prevalent in subjects with elevated NLR (17.33% vs. 12.46%) who had a relative risk (RR) of 1.68 (95% CI = 1.38−2.06, p < 0.0001) and an odds ratio (OR) of 1.94 (95% CI = 1.48−2.56, p < 0.0001) to be hyperglycemic. Nevertheless, NLR failed to discriminate individuals with normal FBG from those with HG based on ROC curve analysis. Pathological fluctuations in NLR may serve as supportive evidence in DM management.

Initial neutrophil/lymphocyte and lymphocyte/monocyte ratios can predict future insulin need in newly diagnosed type 1 diabetes mellitus

OBJECTIVES

The exact mechanism of partial clinical remission in type 1 diabetes mellitus (T1DM) has not been elucidated yet. The severity of the inflammation at the time of diagnosis may affect the occurrence or duration of this phase. We aimed to investigate the relationship between hematological inflammatory parameters at the time of diagnosis in T1DM and (i) daily insulin requirement during the follow-up and (ii) the presence of partial clinical remission period, which was determined according to insulin dose-adjusted HbA_1c levels.

METHODS

A single-center retrospective study was conducted, including children who were diagnosed with T1DM, were positive for at least one autoantibody, and were followed up for one year in our clinic between 2010 and 2020.

RESULTS

Sixty-eight patients (55.9% female, 64.7% prepubertal) were included in the study, whose mean age was 8.4 ± 4.2 years. A total of 38 patients (55.9%) had partial clinical remission. None of the initial hematological indices were associated with the occurrence of partial remission. Initial neutrophil/lymphocyte ratio (NLR) and derived-NLR (d-NLR) levels were significantly lower (p=0.011 and 0.033, respectively) and lymphocyte/monocyte ratio (LMR) levels were significantly higher (p=0.005) in patients who showed an insulin requirement of <0.5 IU/kg/day at the 3rd month after diagnosis.

CONCLUSIONS

Initial hematological parameters were not found as a predictor of partial clinical remission period in T1DM in children. However, a lower NLR and d-NLR, or a higher LMR at the time of diagnosis can be used as an indicator of a low daily insulin need at the 3rd month of T1DM.

Metabolic Reprogramming of Innate Immune Cells as a Possible Source of New Therapeutic Approaches in Autoimmunity

Immune cells undergo different metabolic pathways or immunometabolisms to interact with various antigens. Immunometabolism links immunological and metabolic processes and is critical for innate and adaptive immunity. Although metabolic reprogramming is necessary for cell differentiation and proliferation, it may mediate the imbalance of immune homeostasis, leading to the pathogenesis and development of some diseases, such as autoimmune diseases. Here, we discuss the effects of metabolic changes in autoimmune diseases, exerted by the leading actors of innate immunity, and their role in autoimmunity pathogenesis, suggesting many immunotherapeutic approaches.

Activation pathways that drive CD4+ T cells to break tolerance in autoimmune diseases. Immunol Rev 2022;307:161-190. [PMID: 35142369 PMCID: PMC9255211 DOI: 10.1111/imr.13071]

Autoimmune diseases are characterized by dysfunctional immune systems that misrecognize self as non-self and cause tissue destruction. Several cell types have been implicated in triggering and sustaining disease. Due to a strong association of major histocompatibility complex II (MHC-II) proteins with various autoimmune diseases, CD4+ T lymphocytes have been thoroughly investigated for their roles in dictating disease course. CD4+ T cell activation is a coordinated process that requires three distinct signals: Signal 1, which is mediated by antigen recognition on MHC-II molecules; Signal 2, which boosts signal 1 in a costimulatory manner; and Signal 3, which helps to differentiate the activated cells into functionally relevant subsets. These signals are disrupted during autoimmunity and prompt CD4+ T cells to break tolerance. Herein, we review our current understanding of how each of the three signals plays a role in three different autoimmune diseases and highlight the genetic polymorphisms that predispose individuals to autoimmunity. We also discuss the drawbacks of existing therapies and how they can be addressed to achieve lasting tolerance in patients.

Personalized Immunotherapies for Type 1 Diabetes: Who, What, When, and How?

Our understanding of the immunopathological features of type 1 diabetes (T1D) has greatly improved over the past two decades and has shed light on disease heterogeneity dictated by multiple immune, metabolic, and clinical parameters. This may explain the limited effects of immunotherapies tested so far to durably revert or prevent T1D, for which life-long insulin replacement remains the only therapeutic option. In the era of omics and precision medicine, offering personalized treatment could contribute to turning this tide. Here, we discuss how to structure the selection of the right patient at the right time for the right treatment. This individualized therapeutic approach involves enrolling patients at a defined disease stage depending on the target and mode of action of the selected drug, and better stratifying patients based on their T1D endotype, reflecting intrinsic disease aggressiveness and immune context. To this end, biomarker screening will be critical, not only to help stratify patients and disease stage, but also to select the best predicted responders ahead of treatment and at early time points during clinical trials. This strategy could contribute to increase therapeutic efficacy, notably through the selection of drugs with complementary effects, and to further develop precision multi-hit medicine.

Integrin Regulated Autoimmune Disorders: Understanding the Role of Mechanical Force in Autoimmunity

The pathophysiology of autoimmune disorders is multifactorial, where immune cell migration, adhesion, and lymphocyte activation play crucial roles in its progression. These immune processes are majorly regulated by adhesion molecules at cell–extracellular matrix (ECM) and cell–cell junctions. Integrin, a transmembrane focal adhesion protein, plays an indispensable role in these immune cell mechanisms. Notably, integrin is regulated by mechanical force and exhibit bidirectional force transmission from both the ECM and cytosol, regulating the immune processes. Recently, integrin mechanosensitivity has been reported in different immune cell processes; however, the underlying mechanics of these integrin-mediated mechanical processes in autoimmunity still remains elusive. In this review, we have discussed how integrin-mediated mechanotransduction could be a linchpin factor in the causation and progression of autoimmune disorders. We have provided an insight into how tissue stiffness exhibits a positive correlation with the autoimmune diseases’ prevalence. This provides a plausible connection between mechanical load and autoimmunity. Overall, gaining insight into the role of mechanical force in diverse immune cell processes and their dysregulation during autoimmune disorders will open a new horizon to understand this physiological anomaly.

NETosis in Long-Term Type 1 Diabetes Mellitus and Its Link to Coronary Artery Disease

Background

Neutrophil extracellular traps NETs have been linked to glucose and the pathogenesis of type 1 diabetes mellitus (T1DM). NETs also play a role in vascular inflammation and the development of coronary artery disease (CAD). The role of NETs in CAD progression in patients with long-term T1DM is unclear. We aimed to 1) investigate whether levels of circulating NETs markers were elevated in long-term T1DM subjects compared to controls, and 2) explore whether levels of NETs were related to the presence of CAD.

Material and Methods

102 patients with > 45 years of T1DM and 75 age-matched controls were enrolled in a cross-sectional study. Median age was 62 years. Computed tomography coronary angiography (CTCA) was performed in 148 subjects without established coronary heart disease. For the current study, CAD was defined as a coronary artery stenosis >50%. Double-stranded deoxyribonucleic acid (dsDNA) was measured by a nucleic acid stain, myeloperoxidase-DNA (MPO-DNA), citrullinated histone 3 (H3Cit) and peptidylarginine deiminase 4 (PAD4) by ELISAs, while gene expression of PAD4 was measured in leukocytes from PAXgene tubes.

Results

Circulating MPO-DNA levels were significantly lower in patients with T1DM than in controls (0.17 vs 0.29 OD, p<0.001), while dsDNA, H3Cit, PAD4 and gene expression of PAD4 did not differ with respect to the presence of T1DM. There were no significant associations between NETs markers and HbA1c in the T1DM group. None of the NETs markers differed according to the presence of CAD in patients with T1DM. While all circulating NETs markers correlated significantly with circulating neutrophils in the control group (r=0.292-393, p<0.014), only H3Cit and PAD4 correlated with neutrophils in the T1DM group (r= 0.330-0.449, p ≤ 0.001).

Conclusions

In this cross-sectional study of patients with long-term T1DM and age-matched controls, circulating NETs levels were not consistently associated with the presence of T1DM or glycemic status, and did not differ according to the presence of CAD in patients with T1DM. Our results entail the possibility of altered neutrophil function and reduced NETosis in T1DM. This warrants further investigation.

Candidate Biomarkers for the Prediction and Monitoring of Partial Remission in Pediatric Type 1 Diabetes

The partial remission (PR) phase, a period experienced by most patients with type 1 diabetes (T1D) soon after diagnosis, is characterized by low insulin requirements and improved glycemic control. Given the great potential of this phase as a therapeutic window for immunotherapies because of its association with immunoregulatory mechanisms and β-cell protection, our objective was to find peripheral immunological biomarkers for its better characterization, monitoring, and prediction. The longitudinal follow-up of 17 pediatric patients with new-onset T1D over one year revealed that, during the PR phase, remitter patients show increased percentages of effector memory (EM) T lymphocytes, terminally differentiated EM T lymphocytes, and neutrophils in comparison to non-remitter patients. On the contrary, remitter patients showed lower percentages of naïve T lymphocytes, regulatory T cells (TREG), and dendritic cells (DCs). After a year of follow-up, these patients also presented increased levels of regulatory B cells and transitional T1 B lymphocytes. On the other hand, although none of the analyzed cytokines (IL-2, IL-6, TGF-β1, IL-17A, and IL-10) could distinguish or predict remission, IL-17A was increased at T1D diagnosis in comparison to control subjects, and remitter patients tended to maintain lower levels of this cytokine than non-remitters. Therefore, these potential monitoring immunological biomarkers of PR support that this stage is governed by both metabolic and immunological factors and suggest immunoregulatory attempts during this phase. Furthermore, since the percentage of TREG, monocytes, and DCs, and the total daily insulin dose at diagnosis were found to be predictors of the PR phase, we next created an index-based predictive model comprising those immune cell percentages that could potentially predict remission at T1D onset. Although our preliminary study needs further validation, these candidate biomarkers could be useful for the immunological characterization of the PR phase, the stratification of patients with better disease prognosis, and a more personalized therapeutic management.

Circulating platelet-neutrophil aggregates characterize the development of type 1 diabetes in humans and NOD mice

Platelet-neutrophil aggregates (PNAs) facilitate neutrophil activation and migration and could underpin the recruitment of neutrophils to the pancreas during type 1 diabetes (T1D) pathogenesis. PNAs, measured by flow cytometry, were significantly elevated in the circulation of autoantibody-positive (Aab⁺) children and new-onset T1D children, as well as in pre-T1D (at 4 weeks and 10–12 weeks) and T1D-onset NOD mice, compared with relevant controls, and PNAs were characterized by activated P-selectin⁺ platelets. PNAs were similarly increased in pre-T1D and T1D-onset NOD isolated islets/insulitis, and immunofluorescence staining revealed increased islet-associated neutrophil extracellular trap (NET) products (myeloperoxidase [MPO] and citrullinated histones [CitH3]) in NOD pancreata. In vitro, cell-free histones and NETs induced islet cell damage, which was prevented by the small polyanionic drug methyl cellobiose sulfate (mCBS) that binds to histones and neutralizes their pathological effects. Elevated circulating PNAs could, therefore, act as an innate immune and pathogenic biomarker of T1D autoimmunity. Platelet hyperreactivity within PNAs appears to represent a previously unrecognized hematological abnormality that precedes T1D onset. In summary, PNAs could contribute to the pathogenesis of T1D and potentially function as a pre-T1D diagnostic.

Single-cell RNA sequencing analysis reveals the relationship of bone marrow and osteopenia in STZ-induced type 1 diabetic mice

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scRNA-seq analysis reveals the profiles of bone marrow cells in STZ-induced T1D mice.

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scRNA-seq analysis reveals the heterogeneity of bone marrow immune cells in STZ-induced T1D mice.

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The ratio of BM-neutrophils to B lymphocytes is increased in the bone marrow of STZ-induced T1D mice.

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Osteopenia is occurred in STZ-induced T1D mice.

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This increased ratio is negatively correlated with osteopenia in STZ-induced T1D mice.

Introduction

Type 1 diabetes (T1D) is a multifactorial autoimmune disease. Broad knowledge about the genetics, epidemiology and clinical management of T1D has been achieved, but understandings about the cell varieties in the bone marrow during T1D remain limited.

Objectives

We aimed to present a profile of the bone marrow cells and reveal the relationship of bone marrow and osteopenia in streptozotocin (STZ)-induced T1D mice.

Methods

The whole bone marrow cells from the femurs and tibias of healthy (group C) and STZ-induced T1D mice (group D) were collected for single-cell RNA sequencing analysis. Single-cell flow cytometry and immunohistochemistry were performed to confirm the proportional changes among bone marrow neutrophils (BM-neutrophils) (Cxcr2⁺, Ly6g⁺) and B lymphocytes (Cd19⁺). X-ray and micro-CT were performed to detect bone mineral density. The correlation between the ratio of BM-neutrophils/B lymphocytes and osteopenia in STZ-induced T1D mice was analyzed by nonparametric Spearman correlation analysis.

Results

The bone marrow cells in groups C and D were divided into 12 clusters, and 249 differentially expressed genes were found. The diversity of CD45⁺ immune cells between groups C and D were greatly affected: the proportion of BM-neutrophils showed a significant increase while the proportion of B lymphocytes in group D showed a significant decrease. X-ray and micro-CT analyses confirmed that osteopenia occurred in group D mice. In addition, the results of single-cell flow cytometry and correlation analysis showed that the ratio of BM-neutrophils/B lymphocytes negatively correlated with osteopenia in STZ-induced T1D mice.

Conclusion

A single-cell RNA sequencing analysis revealed the profile and heterogeneity of bone marrow immune cells in STZ-induced T1D mice for the first time. The ratio of BM-neutrophils/B lymphocytes negatively correlated with osteopenia in STZ-induced T1D mice, which may enhance understanding for treating T1D and preventing T1D-induced osteopenia.

Neutrophils and their role in the aetiopathogenesis of type 1 and type 2 diabetes

Multiple and complex aetiological processes underlie diabetes mellitus, which invariably result in the development of hyperglycaemia. Although there are two prevalent distinct forms of the disease, that is, type 1 and type 2 diabetes, accumulating evidence indicates that these syndromes share more aetiopathological mechanisms than originally thought. This compels a rethinking of the approaches to prevent and treat the different manifestations of what eventually becomes a hyperglycaemic state. This review aims to address the involvement of neutrophils, the most abundant type of granulocytes involved in the initiation of the acute phase of inflammation, in the aetiopathogenesis of diabetes mellitus, with a focus on type 1 and type 2 diabetes. We review the evidence that neutrophils are the first leucocytes to react to and accumulate inside target tissues of diabetes, such as the pancreas and insulin-sensitive tissues. We then review available data on the role of neutrophils and their functional alteration, with a focus on NETosis, in the progression towards clinical disease. Finally, we review potential approaches as secondary and adjunctive treatments to limit neutrophil-mediated damage in the prevention of the progression of subclinical disease to clinical hyperglycaemia.

Dynamic changes in immune gene co-expression networks predict development of type 1 diabetes

Significant progress has been made in elucidating genetic risk factors influencing Type 1 diabetes (T1D); however, features other than genetic variants that initiate and/or accelerate islet autoimmunity that lead to the development of clinical T1D remain largely unknown. We hypothesized that genetic and environmental risk factors can both contribute to T1D through dynamic alterations of molecular interactions in physiologic networks. To test this hypothesis, we utilized longitudinal blood transcriptomic profiles in The Environmental Determinants of Diabetes in the Young (TEDDY) study to generate gene co-expression networks. In network modules that contain immune response genes associated with T1D, we observed highly dynamic differences in module connectivity in the 600 days (~ 2 years) preceding clinical diagnosis of T1D. Our results suggest that gene co-expression is highly plastic and that connectivity differences in T1D-associated immune system genes influence the timing and development of clinical disease.

Novel neutrophil phenotypic signature in pediatric patients with type 1 diabetes and diabetic ketoacidosis

Type 1 diabetes (T1D) is a chronic inflammatory condition sometimes complicated by acute diabetic ketoacidosis (DKA). A subset of patients with T1D develop DKA independent of known risk factors. This study tested the hypothesis that circulating polymorphonuclear leukocytes (PMN) from children with T1D and DKA would exhibit a primed phenotype and that the signature would be unique in patients predisposed to have DKA. Using a prospective cohort study design, neutrophil phenotype was assessed in 30 patients with T1D seen in endocrinology clinic for routine care, 30 patients with acute DKA, and 36 healthy donors. Circulating PMN from patients with DKA display a primed phenotype with increased basal cell-surface CD11b, L-selectin shedding, and enhanced fMLF-elicited reactive oxygen species (ROS) production. Moreover, PMN from T1D patients both with and without DKA lack the capacity to be further primed by incubation with TNF-α, a classic priming stimulus. Primed PMN phenotypic signatures demonstrated are independent of hemoglobin A1c, the premier biological marker for DKA risk, and are consistent with a hyperinflammatory state. A single nucleotide polymorphism in TLR-1 (1805G>T), known to be associated with a hyperinflammatory PMN phenotype, correlated with DKA. This study elucidated a novel phenotypic signature in circulating PMN from children with T1D with and without DKA, and suggests the possibility of a previously unrecognized PMN phenotype with potential clinical implications. Immunophenotype and genotype may be applicable as biomarkers for DKA risk stratification in patients with T1D.

Increase of Neutrophil Extracellular Traps, Mitochondrial DNA and Nuclear DNA in Newly Diagnosed Type 1 Diabetes Children but Not in High-Risk Children

Neutrophil extracellular traps (NETs) and mitochondrial DNA (mtDNA) are inflammatory mediators involved in the development of type 1 diabetes (T1D). Pancreas-infiltrating neutrophils can release NETs, contributing to the inflammatory process. Levels of NETs are increased in serum from patients with T1D and mtDNA is increased in adult T1D patients. Our aim was to investigate extracellular DNA (NETs, mtDNA and nuclear DNA) in children with newly diagnosed T1D and in children at high risk of the disease. We also elucidated if extracellular DNA short after diagnosis could predict loss of endogenous insulin production. Samples were analysed for mtDNA and nuclear DNA using droplet digital PCR and NETs were assessed by a NET-remnants ELISA. In addition, in vitro assays for induction and degradation of NETs, as well as analyses of neutrophil elastase, HLA genotypes, levels of c-peptide, IL-1beta, IFN and autoantibodies (GADA, IA-2A, IAA and ZnT8A) were performed. In serum from children 10 days after T1D onset there was an increase in NETs (p=0.007), mtDNA (p<0.001) and nuclear DNA (p<0.001) compared to healthy children. The elevated levels were found only in younger children. In addition, mtDNA increased in consecutive samples short after onset (p=0.017). However, levels of extracellular DNA short after onset did not reflect future loss of endogenous insulin production. T1D serum induced NETs in vitro and did not deviate in the ability to degrade NETs. HLA genotypes and autoantibodies, except for ZnT8A, were not associated with extracellular DNA in T1D children. Serum from children with high risk of T1D showed fluctuating levels of extracellular DNA, sometimes increased compared to healthy children. Therefore, extracellular DNA in serum from autoantibody positive high-risk children does not seem to be a suitable biomarker candidate for prediction of T1D. In conclusion, we found increased levels of extracellular DNA in children with newly diagnosed T1D, which might be explained by an ongoing systemic inflammation.

Circulating cell free DNA response to exhaustive exercise in average trained men with type I diabetes mellitus

It is believed that neutrophils extracellular traps (NETs) formation is responsible for the increase in cf DNA after exercise. Since T1DM is accompanied by enhanced NETs generation, we compared exercise-induced increase in cf DNA in 14 men with T1DM and 11 healthy controls and analyzed its association with exercise load. Subjects performed a treadmill run to exhaustion at speed corresponding to 70% of their personal VO2max. Blood was collected before and just after exercise for determination of plasma cf nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, blood cell count and metabolic markers. Exercise resulted in the increase in median cf n-DNA from 3.9 ng/mL to 21.0 ng/mL in T1DM group and from 3.3 ng/mL to 28.9 ng/mL in controls. Median exercise-induced increment (∆) in cf n-DNA did not differ significantly in both groups (17.8 ng/mL vs. 22.1 ng/mL, p = 0.23), but this variable correlated with run distance (r = 0.66), Δ neutrophils (r = 0.86), Δ creatinine (r = 0.65) and Δ creatine kinase (r = 0.77) only in controls. Pre- and post-exercise cf mt-DNA were not significantly different within and between groups. These suggest low usefulness of Δ cf n-DNA as a marker of exercise intensity in T1DM men.

Influence of PTPN22 Allotypes on Innate and Adaptive Immune Function in Health and Disease

Protein tyrosine phosphatase, non-receptor type 22 (PTPN22) regulates a panoply of leukocyte signaling pathways. A single nucleotide polymorphism (SNP) in PTPN22, rs2476601, is associated with increased risk of Type 1 Diabetes (T1D) and other autoimmune diseases. Over the past decade PTPN22 has been studied intensely in T cell receptor (TCR) and B cell receptor (BCR) signaling. However, the effect of the minor allele on PTPN22 function in TCR signaling is controversial with some reports concluding it has enhanced function and blunts TCR signaling and others reporting it has reduced function and increases TCR signaling. More recently, the core function of PTPN22 as well as functional derangements imparted by the autoimmunity-associated variant allele of PTPN22 have been examined in monocytes, macrophages, dendritic cells, and neutrophils. In this review we will discuss the known functions of PTPN22 in human cells, and we will elaborate on how autoimmunity-associated variants influence these functions across the panoply of immune cells that express PTPN22. Further, we consider currently unresolved questions that require clarification on the role of PTPN22 in immune cell function.

Intracerebral Hemorrhage and Diabetes Mellitus: Blood-Brain Barrier Disruption, Pathophysiology, and Cognitive Impairments

There is a surge in diabetes incidence with an estimated 463 million individuals been diagnosed worldwide. Diabetes Mellitus (DM) is a major stroke-related comorbid condition that increases the susceptibility of disabling post-stroke outcomes. Although less common, intracerebral hemorrhage (ICH) is the most dramatic subtype of stroke that is associated with higher mortality, particularly in DM population. Previous studies have focused mainly on the impact of DM on ischemic stroke. Few studies have focused on impact of DM on ICH and discussed the blood-brain barrier disruption, brain edema, and hematoma formation. However, more recently, investigating the role of oxidative damage and reactive oxygen species (ROS) production in preclinical studies involving DM-ICH animal models has gained attention. But, little is known about the correlation between neuroinflammatory processes, glial cells activation, and peripheral immune cell invasion with DM-ICH injury. DM and ICH patients experience impaired abilities in multiple cognitive domains by relatively comparable mechanisms, which could get exacerbated in the setting of comorbidities. In this review, we discuss both the pathology of DM as a comorbid condition for ICH and the potential molecular therapeutic targets for the clinical management of the ICH and its recovery.

First and Second Waves of Coronavirus Disease 2019 in Madrid, Spain: Clinical Characteristics and Hematological Risk Factors Associated With Critical/Fatal Illness

Supplemental Digital Content is available in the text.

Objectives:

This study aims to determine similarities and differences in clinical characteristics between the patients from two waves of severe acute respiratory syndrome coronavirus-2 infection at the time of hospital admission, as well as to identify risk biomarkers of coronavirus disease 2019 severity.

Design:

Retrospective observational study.

Setting:

A single tertiary-care center in Madrid.

Patients:

Coronavirus disease 2019 adult patients admitted to hospital from March 4, 2020, to March 25, 2020 (first infection wave), and during July 18, 2020, and August 20, 2020 (second infection wave).

Interventions:

Treatment with a hospital-approved drug cocktail during hospitalization.

Measurements and Main Results:

Demographic, clinical, and laboratory data were compared between the patients with moderate and critical/fatal illness across both infection waves. The median age of patients with critical/fatal coronavirus disease 2019 was 67.5 years (interquartile range, 56.75–78.25 yr; 64.5% male) in the first wave and 59.0 years (interquartile range, 48.25–80.50 yr; 70.8% male) in the second wave. Hypertension and dyslipidemia were major comorbidities in both waves. Body mass index over 25 and presence of bilateral pneumonia were common findings. Univariate logistic regression analyses revealed an association of a number of blood parameters with the subsequent illness progression and severity in both waves. However, some remarkable differences were detected between both waves that prevented an accurate extrapolation of prediction models from the first wave into the second wave. Interleukin-6 and d-dimer concentrations at the time of hospital admission were remarkably higher in patients who developed a critical/fatal condition only during the first wave (p < 0.001), although both parameters significantly increased with disease worsening in follow-up studies from both waves. Multivariate analyses from wave 1 rendered a predictive signature for critical/fatal illness upon hospital admission that comprised six blood biomarkers: neutrophil-to-lymphocyte ratio (≥ 5; odds ratio, 2.684 [95% CI, 1.143–6.308]), C-reactive protein (≥ 15.2 mg/dL; odds ratio, 2.412 [95% CI, 1.006–5.786]), lactate dehydrogenase (≥ 411.96 U/L; odds ratio, 2.875 [95% CI, 1.229–6.726]), interleukin-6 (≥ 78.8 pg/mL; odds ratio, 5.737 [95% CI, 2.432–13.535]), urea (≥ 40 mg/dL; odds ratio, 1.701 [95% CI, 0.737–3.928]), and d-dimer (≥ 713 ng/mL; odds ratio, 1.903 [95% CI, 0.832–4.356]). The predictive accuracy of the signature was 84% and the area under the receiver operating characteristic curve was 0.886. When the signature was validated with data from wave 2, the accuracy was 81% and the area under the receiver operating characteristic curve value was 0.874, albeit most biomarkers lost their independent significance. Follow-up studies reassured the importance of monitoring the biomarkers included in the signature, since dramatic increases in the levels of such biomarkers occurred in critical/fatal patients over disease progression.

Conclusions:

Most parameters analyzed behaved similarly in the two waves of coronavirus disease 2019. However, univariate logistic regression conducted in both waves revealed differences in some parameters associated with poor prognosis in wave 1 that were not found in wave 2, which may reflect a different disease stage of patients on arrival to hospital. The six-biomarker predictive signature reported here constitutes a helpful tool to classify patient’s prognosis on arrival to hospital.

Vitamin D affects the neutrophil-to-lymphocyte ratio in patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

Chronic inflammation is an underlying feature of type 2 diabetes mellitus. Hypovitaminosis D is associated with type 2 diabetes mellitus, but whether it contributes to chronic inflammation is unclear. We examined the effects of vitamin D on various immune markers to evaluate its contribution to systemic inflammation in type 2 diabetes mellitus.

MATERIALS AND METHODS

We retrospectively analyzed data from type 2 diabetes mellitus patients, people with prediabetes and control patients without diabetes (n = 9,746). Demographic and clinical variables were evaluated using descriptive statistics and generalized linear regression. A stratified analysis based on total serum vitamin D was also carried out.

RESULTS

Neutrophil count was a significant predictor of 1,5-anhydroglucitol and glycated hemoglobin (HbA1c) in patients with prediabetes (1,5-anhydroglucitol: β = -0.719, P < 0.001 and HbA1c: β = -0.006, P = 0.002) and patients with diabetes (1,5-anhydroglucitol: β = 0.207, P = 0.004 and HbA1c: β = -0.067, P = 0.010). Lymphocyte count was a significant predictor of HbA1c in patients without diabetes (β = 0.056, P < 0.001) and patients with prediabetes (β = 0.038, P < 0.001). The neutrophil-to-lymphocyte ratio (NLR) was a significant predictor of HbA1c in patients without diabetes (β = -0.001, P = 0.032). No immune markers differed significantly based on vitamin D level among patients without diabetes (P> 0.05 for all). Among patients with prediabetes, those who were vitamin D-deficient had the highest NLR (P = 0.040). Among patients with diabetes, those who were vitamin D-deficient had the highest neutrophil count (P = 0.001), lowest lymphocyte count (P = 0.016) and highest NLR (P < 0.001).

CONCLUSIONS

The NLR is strongly influenced by serum vitamin D level. Given the high prevalence of hypovitaminosis D and elevated NLR among chronic disease patients and the elderly, our results suggest that clinical interpretation of NLR as a predictive marker of type 2 diabetes mellitus-related inflammation should consider vitamin D level, age and pre-existing morbidity.

Neutrophil Extracellular Traps and Their Implications in Cardiovascular and Inflammatory Disease

Neutrophils are primary effector cells of innate immunity and fight infection by phagocytosis and degranulation. Activated neutrophils also release neutrophil extracellular traps (NETs) in response to a variety of stimuli. These NETs are net-like complexes composed of cell-free DNA, histones and neutrophil granule proteins. Besides the evolutionarily conserved mechanism to capture and eliminate pathogens, NETs are also associated with pathophysiological processes of various diseases. Here, we elucidate the mechanisms of NET formation and their different implications in disease. We focused on autoinflammatory and cardiovascular disorders as the leading cause of death. Neutrophil extracellular traps are not only present in various cardiovascular diseases but play an essential role in atherosclerotic plaque formation, arterial and venous thrombosis, as well as in the development and progression of abdominal aortic aneurysms. Furthermore, NETosis can be considered as a source of autoantigens and maintains an inflammatory milieu promoting autoimmune diseases. Indeed, there is further need for research into the balance between NET induction, inhibition, and degradation in order to pharmacologically target NETs and their compounds without impairing the patient’s immune defense. This review may be of interest to both basic scientists and clinicians to stimulate translational research and innovative clinical approaches.

Mechanism and transmission routes of COVID-19

A recent form of novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has emerged in China, appears to have a distinct genome from the previously sequenced coronavirus. SARS-CoV-2 is shown to cause acute respiratory infections in humans. SARS-CoV-2 is a ribonucleic acid virus believed to have transmitted from a zoonotic host accompanied by human-to-human spread that has contributed to a recent pandemic. Clinical symptoms of coronavirus disease 2019 patients start with tiredness, sore throat, cough, running nose, and fever, and then progressing to trouble breathing and loss of taste; severe cases experience death due to organ failure. Also, a few affected individuals can also be asymptomatic. Elderly and individuals with chronic conditions viz. hypertension, diabetes, and cardiac complications are more vulnerable to viral infection and disease severity. In this chapter, we discuss in detail the origin of SARS-CoV-2, followed by the various risk factors that could influence the infection, and finally the different modes of viral transmission.

Neutrophil-Associated Inflammatory Changes in the Pre-Diabetic Pancreas of Early-Age NOD Mice

A growing body of evidence indicates that neutrophils are the first major leukocyte population accumulating inside the pancreas even before the onset of a lymphocytic-driven impairment of functional beta cells in type 1 diabetes mellitus (T1D). In humans, pancreata from T1D deceased donors exhibit significant neutrophil accumulation. We present a time course of previously unknown inflammatory changes that accompany neutrophil and neutrophil elastase accumulation in the pancreas of the non-obese diabetic (NOD) mouse strain as early as 2 weeks of age. We confirm earlier findings in NOD mice that neutrophils accumulate as early as 2 weeks of age. We also observe a concurrent increase in the expression of neutrophil elastase in this time period. We also detect components of neutrophil extracellular traps (NET) mainly in the exocrine tissue of the pancreas during this time as well as markers of vascular pathology as early as 2 weeks of age. Age- and sex-matched C57BL/6 mice do not exhibit these features inside the pancreas. When we treated NOD mice with inhibitors of myeloperoxidase and neutrophil elastase, two key effectors of activated neutrophil activity, alone or in combination, we were unable to prevent the progression to hyperglycemia in any manner different from untreated control mice. Our data confirm and add to the body of evidence demonstrating neutrophil accumulation inside the pancreas of mice genetically susceptible to T1D and also offer novel insights into additional pathologic mechanisms involving the pancreatic vasculature that have, until now, not been discovered inside the pancreata of these mice. However, inhibition of key neutrophil enzymes expressed in activated neutrophils could not prevent diabetes. These findings add to the body of data supporting a role for neutrophils in the establishment of early pathology inside the pancreas, independently of, and earlier from the time at onset of lymphocytic infiltration. However, they also suggest that inhibition of neutrophils alone, acting via myeloperoxidase and neutrophil elastase only, in the absence of other other effector cells, is insufficient to alter the natural course of autoimmune diabetes, at least in the NOD model of the disease.

The Role of Glucagon in Glycemic Variability in Type 1 Diabetes: A Narrative Review

Type 1 diabetes mellitus (T1DM) is a progressive disease as a result of the severe destruction of islet β-cell function, which leads to high glucose variability in patients. However, α-cell function is also compromised in patients with T1DM, characterized by aberrant fasting and postprandial glucagon secretion. According to recent studies, this aberrant glucagon secretion plays an increasing role in hyperglycemia, insulin-induced hypoglycemia and exercise-associated hypoglycemia in patients with T1DM. With application of continuous glucose monitoring system, dozens of metrics enable the assessment of glycemic variability, which is an integral component of glycemic control for patients with T1DM. There is growing evidences to illustrate the contribution of glucagon secretion to the glycemic variability in patients with T1DM, which may promote the development of new treatment strategies aiming to mitigate glycemic variability associated with aberrant glucagon secretion.

Assessment of hematologic indices and their correlation to hemoglobin A1c among Bosnian children with type 1 diabetes mellitus and their healthy peers

Background

Altered levels of many hematological parameters have been directly associated with diabetes in adults, while studies on children with type 1 diabetes mellitus are lacking. The aim of this study was to determine hematological indices in diabetic Bosnian children in comparison to healthy controls as well as to correlate their levels to blood glucose and hemoglobin A1c.

Methods

100 healthy and 100 children with type 1 diabetes mellitus (age 1-18) were included in this study. Complete blood count, hemoglobin A1c, and glucose were tested. Results were analysed by IBM SPSS Statistics version 23.

Results

Significant differences (p<0.05) between healthy and diabetic children were found in relation to HbA1c, glucose, mean platelet volume, the number of white blood cells and erythrocytes, hematocrit, hemoglobin and MCH values. No gender differences or significant age differences were seen for hemoglobin, hematocrit, and MCV, while platelets, MPV, and MCH differed by age only in healthy children. When diabetic children were classified according to HbA1c levels, significant differences were seen for erythrocyte count and hematocrit value (p=0.013 and 0.019, respectively). The number of erythrocytes and white blood cells correlated significantly with HbA1c (p=0.037 and 0.027, respectively).

Conclusions

Lower levels of erythrocytes, hematocrit, and hemoglobin in diabetic compared to healthy children indicate possible development of anemia, while higher MCV, MCH, and MPV values indicate an alteration in erythrocyte morphology. Hematological indices could be a useful inexpensive tool in the diagnosis and follow up of type 1 diabetes in children.

Epigenetic Histone Modifications in the Pathogenesis of Diabetic Kidney Disease

Diabetic kidney disease (DKD), as the main complication of diabetes mellitus, is the primary cause of the end-stage renal disease (ESRD) and the most common chronic kidney disease. Overall, 30-40% of patients with type 1 and type 2 diabetes eventually develop DKD. Although some diabetes patients have intensified glycemic control, they still develop diabetic kidney disease. Current treatment methods can alleviate but do not markedly halt disease development, resulting in renal failure and severe complications, even contributing to elevated morbidity and mortality rates. DKD is a disease with interactions of genes and the environment. Emerging evidence indicates that DKD-associated key genes are also regulated by the epigenetic mechanism. Recently, increasing researches involving cells and experimental animals demonstrated that histone post-translational modifications can mediate gene expression, which correlated with diabetic kidney disease. Novel therapeutic strategies for epigenetic events could be beneficial for the early detection and treatment of DKD to prevent it from developing into end-stage renal disease (ESRD). In this review, we discuss prior findings in the field of histone modifications in DKD, especially histone acetylation and histone methylation. We then focus on recent developments in histone acetylation and methylation involved in the pathogenesis of DKD.

Loganic Acid, an Iridoid Glycoside Extracted from Cornus mas L. Fruits, Reduces of Carbonyl/Oxidative Stress Biomarkers in Plasma and Restores Antioxidant Balance in Leukocytes of Rats with Streptozotocin-Induced Diabetes Mellitus

The various complications related to diabetes are due to the alteration in plasma components and functional activity of blood cells, hence the search for preventive remedies that would ameliorate the clinical condition of patients is a relevant problem today. The main aim of the present study was to examine the antidiabetic potency and antioxidant effects of loganic acid (LA) in blood of diabetic rats. LA showed a restoration of balance between functioning of antioxidant defense system and oxidative stress in leukocytes without notable effects on blood glucose levels when administered orally to rats (20 mg/kg b.w./day) for 14 days. LA ameliorated antioxidant status in leukocytes, as indicated by increasing the content of reduced glutathione and activities of catalase, glutathione peroxidase and glutathione reductase along with decreasing levels of intracellular reactive oxygen species. In addition, we observed the ability of LA to protect against formation and accumulation of glycation and oxidation protein products and malondialdehyde derivates in plasma. Therefore, LA showed antioxidant properties that may have beneficial effects under diabetes. Such results may represent LA as one of the plant components in the development of new drugs that will correct metabolic and functional disorders in leukocytes under diabetes.

Carvedilol prevents pancreatic β-cell damage and the development of type 1 diabetes in mice by the inhibition of proinflammatory cytokines, NF-κB, COX-2, iNOS and oxidative stress

Inflammation is one of the main mechanisms of pancreatic β-cell damage and the development of type 1 diabetes (T1D). Carvedilol, a beta-adrenergic receptor blocker, has been demonstrated to have anti-inflammatory and antioxidant effects. The aim of this study was to investigate the protective effect of carvedilol against pancreatic β-cell damage and the development of T1D in an experimental model. T1D was induced in mice by multiple low-dose streptozotocin (STZ) injections. Diabetic mice were treated with carvedilol (15 and 20 mg/kg/day, orally) for 14 days. Results showed that blood glucose levels, diabetes incidence, body weight loss and insulitis in the pancreatic tissue were significantly reduced in mice treated with carvedilol. Treatment of mice with carvedilol significantly increased the levels of antioxidants glutathione (GSH), superoxide dismutase (SOD), and catalase and decreased the levels of malondialdehyde (MDA), nitric oxide (NO) and myeloperoxidase (MPO) in the pancreatic tissue as compared with those in the STZ-induced diabetic mice. Carvedilol decreased the expression of nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as important modulators of inflammation and β-cell damage in the pancreatic tissue. In addition, carvedilol significantly reduced the levels of proinflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 IL-12, IL-17, interferon (IFN)-γ and chemokine MCP-1, while increased the anti-inflammatory cytokine IL-10 in the pancreatic tissue. In conclusion, these findings suggest that carvedilol is able to prevent pancreatic β-cell damage and the development of T1D in mice by the inhibition of inflammatory and oxidative mediators.

Periodontal Disease in Diabetes Mellitus: A Case-Control Study in Smokers and Non-Smokers

INTRODUCTION

It is well established that periodontal disease (PD) and diabetes mellitus (DM) can have a detrimental effect on each other's disease course, and that cigarette smoking exacerbates both conditions. However, literature on the periodontal status of smokers with DM is scarce, and the studies conducted to date did not use healthy controls or non-smokers with DM as controls. Consequently, the individual effects of smoking and DM on PD are difficult to untangle and estimate.

METHODS

A total of 128 participants were recruited to this study and their data analyzed. They were assigned to four groups: smoking patients with DM (SDM); non-smoking patients with DM (NSDM); smokers without DM (control group, SC) and (4) non-smokers without DM (control group, NSC). Each group consisted of 32 age-matched participants. The periodontal status of the participants was assessed by full oral examination. To express periodontal status, we used the four-stage classification introduced by Fernandes and colleagues (J Periodontol. 80(7):1062-1068, 2009). The control of DM was estimated by measuring hemoglobin A1c (HbA1c) levels in the peripheral blood.

RESULTS

A significant difference in the severity of PD was found between the SC and NSC groups (p = 0.027) and between the NSC and SDM groups (p = 0.000), while the difference between the NSDM and SDM groups approached significance (p = 0.052). No person in the smoker groups could be classified as having a healthy periodontal status. The four-stage classification followed a normal distribution in the healthy, non-smoking controls (NSC). Smoking caused a shift toward medium-severe PD, while a marked shift toward the most severe stage was observed when both smoking and DM were present (SDM). There was no significant association between the type of DM and periodontal status, nor between diabetes control and the severity of PD. Persons in the SDM group had significantly fewer teeth than those in the NSC group (mean ± standard deviation: 16.0 ± 7.9 vs. 20.7 ± 5.6; p = 0.02).

CONCLUSION

Smoking damages the periodontium of even healthy individuals, but the damage is multiplied in a smoker who has DM, even though the effect of DM alone on periodontium health is relatively mild. Our results suggest a synergy between DM and smoking in terms of damage to the periodontal tissues, but the limited sample size of this study does not allow any hard conclusion to be drawn.

Neutrophil count as a reliable marker for diabetic kidney disease in autoimmune diabetes

BACKGROUND

A growing body of evidence supports neutrophils as having an active role in the development of diabetic kidney disease (DKD). However, the clinical relevance of neutrophils and DKD in autoimmune diabetes remains unknown. This study aimed to investigate the relationship between circulating neutrophils and DKD in autoimmune diabetes.

METHODS

Patients with type 1 diabetes (T1D, n = 226) and latent autoimmune diabetes in adults (LADA, n = 79) were enrolled and stratified according to the urinary albumin to creatinine ratio (ACR). Circulating levels of white blood cells (WBCs), including neutrophils, were measured in a central laboratory, and the neutrophil-to-lymphocyte ratio (NLR) was calculated. The risk factors associated with DKD were analysed by logistic regression.

RESULTS

In T1D and LADA patients, the peripheral neutrophil counts increased in parallel with DKD advancement. The neutrophil counts in the patients with macroalbuminuria were significantly higher than those in the patients with normoalbuminuria for each type of diabetes. Furthermore, neutrophil counts positively correlated with ACR in T1D. In addition, neutrophils were independently associated with DKD in T1D in the logistic regression analysis, when various well-known risk factors, including age, gender, disease duration, hypertension, dyslipidemia and smoking status, were adjusted.

CONCLUSIONS

Neutrophil counts are closely associated with DKD in patients with autoimmune diabetes, suggesting that neutrophil-mediated inflammation may be involved in the pathogenesis of DKD in patients with autoimmune diabetes.

Diabetes, infection risk and COVID-19

BACKGROUND

Individuals with diabetes are at a greater risk of hospitalization and mortality resulting from viral, bacterial, and fungal infections. The coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has spread quickly to more than 213 countries and claimed 395,779 lives as of June 7, 2020. Notably, in several studies, diabetes is one of the most reported comorbidities in patients with severe COVID-19.

SCOPE OF REVIEW

In this review, I summarize the clinical data on the risk for infectious diseases in individuals with diabetes while highlighting the mechanisms for altered immune regulation. The focus is on coronaviruses. Based on the new clinical data obtained from COVID-19 patients, a discussion of mechanisms, such as cytokine storm, pulmonary and endothelial dysfunction, and hypercoagulation, that may render individuals with diabetes more vulnerable to COVID-19 is provided.

MAJOR CONCLUSIONS

Epidemiological studies show that poorly controlled diabetes is a risk factor for various infectious diseases. Given the global burden of diabetes and the pandemic nature of coronaviruses, understanding how diabetes affects COVID-19 severity is critical to designing tailored treatments and clinical management of individuals affected by diabetes.

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.

Crosstalk Between Immunity System Cells and Pancreas. Transformation of Stem Cells Used in the 3D Bioprinting Process as a Personalized Treatment Method for Type 1 Diabetes

Interactions between the immune system and the pancreas are pivotal in understanding how and why β cells' damage causes problems with pancreas functioning. Pancreatic islets are crucial in maintaining glucose homeostasis in organs, tissue and cells. Autoimmune aggression towards pancreatic islets, mainly β cells, leads to type 1 diabetes-one of the most prevalent autoimmune disease in the world, being a worldwide risk to health of many people. In this review, we highlight the role of immune cells and its influence in the development of autoimmunity in Langerhans islets. Moreover, we discuss the impact of the immunological factors on future understanding possible recurrence of autoimmunity on 3D-bioprinted bionic pancreas.

Neutrophil Extracellular Trap Induced Dendritic Cell Activation Leads to Th1 Polarization in Type 1 Diabetes

Neutrophils releasing neutrophil extracellular traps (NETs) infiltrate the pancreas prior to type 1 diabetes (T1D) onset; however, the precise nature of their contribution to disease remains poorly defined. To examine how NETs affect immune functions in T1D, we investigated NET composition and their effect on dendritic cells (DCs) and T lymphocytes in T1D children. We showed that T1D patient NET composition differs substantially from that of healthy donors and that the presence of T1D-NETs in a mixed peripheral blood mononuclear cell culture caused a strong shift toward IFNγ-producing T lymphocytes, mediated through activation of innate immunity cells in T1D samples. Importantly, in a monocyte-derived DC (moDC) culture, NETs induced cytokine production, phenotypic change and IFNγ-producing T cells only in samples from T1D patients but not in those from healthy donors. RNA-seq analysis revealed that T1D-NETs presence causes TGFβ downregulation and IFNα upregulation and creates pro-T1D signature in healthy moDCs.

Possible Involvement of Vitamin C in Periodontal Disease-Diabetes Mellitus Association

Ascorbic acid (vitamin C) is an important water-soluble vitamin found in many fruits and vegetables. It has well-documented beneficial effects on the human body and is used as a supplement, alone or in combination with other vitamins and minerals. Over recent years, research has focused on possible new therapeutic actions in chronic conditions including periodontal disease (PD). We conducted a systematic review on clinical trials from four databases (PubMed, Clinical Trials, Cochrane, Web of Science) which measured plasmatic/salivary levels of ascorbic acid in PD–diabetes mellitus (DM) association. Six studies were included in our review, three of them analyzing patients with different grades of PD and DM who received vitamin C as a treatment (500 mg vitamin C/day for 2 months and 450 mg/day for 2 weeks) or as part of their alimentation (guava fruits), in combination with standard therapies and procedures. Decreased levels of vitamin C were observed in PD patients with DM but data about efficacy of vitamin C administration are inconclusive. Given the important bidirectional relationship between PD and DM, there is a strong need for more research to assess the positive effects of ascorbic acid supplementation in individuals suffering from both diseases and also its proper regimen for these patients.

Identification of an Early Unipotent Neutrophil Progenitor with Pro-tumoral Activity in Mouse and Human Bone Marrow

Neutrophils are short-lived cells that play important roles in both health and disease. Neutrophils and monocytes originate from the granulocyte monocyte progenitor (GMP) in bone marrow; however, unipotent neutrophil progenitors are not well defined. Here, we use cytometry by time of flight (CyTOF) and single-cell RNA sequencing (scRNA-seq) methodologies to identify a committed unipotent early-stage neutrophil progenitor (NeP) in adult mouse bone marrow. Importantly, we found a similar unipotent NeP (hNeP) in human bone marrow. Both NeP and hNeP generate only neutrophils. NeP and hNeP both significantly increase tumor growth when transferred into murine cancer models, including a humanized mouse model. hNeP are present in the blood of treatment-naive melanoma patients but not of healthy subjects. hNeP can be readily identified by flow cytometry and could be used as a biomarker for early cancer discovery. Understanding the biology of hNeP should allow the development of new therapeutic targets for neutrophil-related diseases, including cancer.

Innate Immunity Mediated Inflammation and Beta Cell Function: Neighbors or Enemies?

Type 1 diabetes (T1D) is still considered a huge burden because the available treatments are not effective in preventing the onset or progression of the disease. Recently, the idea that diabetes is an autoimmune disease mediated exclusively by T cells has been reshaped. In fact, T cells are not the only players with an active role in beta cell destruction. Macrophages and neutrophils, which physiologically reside in pancreatic tissue, can also participate in tissue homeostasis and damage by promoting innate immune responses and modulating inflammation. During the development of the pancreatic islet inflammation there is a strong interplay of both adaptive and innate immune cells, and the presence of innate immune cells has been demonstrated both in exocrine and endocrine pancreatic compartments during the earliest stages of insulitis. Innate immune cell populations secrete cytokines, which must be considered both as physiological and pathological mediators. In fact, it has been demonstrated that cytokines could regulate directly and indirectly insulin secretion and, simultaneously, trigger inflammatory reaction. Indeed, cytokines pathways could represent targets both to improve glucose metabolism and to prevent autoimmune damage. Concordantly, the combination of immunomodulatory strategies against both innate and adaptive immunity should be tested in the next future, as they can be more efficient to prevent or delay islet damage and T1D onset.

Abnormal Neutrophil Transcriptional Signature May Predict Newly Diagnosed Latent Autoimmune Diabetes in Adults of South China

OBJECTIVE

Latent autoimmune diabetes in adults (LADA) is an autoimmune diabetes characterized by slowly progressive of β-cell function deterioration. Our previous finding demonstrated that neutrophil numbers and migration abilities display distinct levels in different types of diabetes, including LADA, whereas its pathological alterations in the development of LADA remain unknown. We aimed to investigate the changes in transcriptional levels of peripheral neutrophils in newly diagnosed LADA.

METHODS

Peripheral blood neutrophils were isolated from newly diagnosed LADA patients (n = 5) and age-and sex-matched healthy controls (n = 5). The Transcriptomic signature was determined by RNA sequencing (RNA-seq). Differentially expressed genes (DEG) were screened, followed by analyzing downstream Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Real-time polymerase chain reaction (qPCR) was applied for validation in LADA patients (n = 9) and age-and sex-matched healthy controls (n = 18), including sequencing samples.

RESULTS

Compared with controls, 4105 DEG were screened in LADA patients, including 2661 upregulated and 1444 downregulated DEG. In GO analysis, DEG are mainly involved in leukocyte degranulation, myeloid cell differentiation, and immune response-regulating signaling. The top enriched KEGG pathways included cytokine-cytokine receptor interaction, adhesion molecule signaling, nuclear factor-κB (NF-κB) signaling and Th17 cell differentiation. Consistent with RNA-seq results, SELL, ITGA4, ITGAM, NCF4, ARHGAP3, and CLDN15 are upregulated in neutrophils by qPCR.

CONCLUSION

The present study results provided a profile of DEG in the newly diagnosed LADA of south China. Our study reveals an abnormality in neutrophil disposition at the transcriptional level in LADA. Several essential genes may be involved in of LADA's pathological process, which may be useful to guide prediction for LADA and further investigation into the pathogenesis for this disease.

Advances in Knowledge of Candidate Genes Acting at the Beta-Cell Level in the Pathogenesis of T1DM

T1DM (type 1 diabetes mellitus), which results from the irreversible elimination of beta-cells mediated by autoreactive T cells, is defined as an autoimmune disease. It is widely accepted that T1DM is caused by a combination of genetic and environmental factors, but the precise underlying molecular mechanisms are still unknown. To date, more than 50 genetic risk regions contributing to the pathogenesis of T1DM have been identified by GWAS (genome-wide association studies). Notably, more than 60% of the identified candidate genes are expressed in islets and beta-cells, which makes it plausible that these genes act at the beta-cell level and play a key role in the pathogenesis of T1DM. In this review, we focus on the current status of candidate genes that act at the beta-cell level by regulating the innate immune response and antiviral activity, affecting susceptibility to proapoptotic stimuli and influencing the pancreatic beta-cell phenotype.