Impact of coronavirus disease 2019 in seasonal variation of hemoglobin A1c in adults with type 1 diabetes and the effect of the mode of treatment: a single-center retrospective study for 2019 and 2021 and analysis by the mode of treatment.

The study was aimed to investigate the seasonal variation of hemoglobin A1c (HbA1c) in adults with type 1 diabetes (T1D) and the impact of coronavirus disease 2019 (COVID-19) by comparing 2019 and 2021 data and differences in treatment modes. This was a single-center retrospective observational study including 52 adult patients with T1D who regularly visited hospital in 2019 and 2021. Twenty-five patients used multiple daily injections (MDI)/self-measurement of blood glucose (SMBG), 16 used MDI/intermittently scanned continuous glucose monitoring (isCGM), 9 used sensor-augmented pump (SAP), and 2 used continuous subcutaneous insulin infusion (CSII)/isCGM. The mean HbA1c level was calculated for each month. The correlation between monthly means of temperature and HbA1c was investigated. Similar analyses were performed for the MDI/SMBG, MDI/isCGM, and SAP + CSII/isCGM groups. HbA1c levels in 2019 decreased in summer and increased in winter and showed a significant negative correlation with temperature (r = -0.652, p = 0.022). However, HbA1c in 2021 showed no seasonal variation and no correlation with temperature (r = -0.134, p = 0.678) and tended to decline after the three emergency declarations. HbA1c in the MDI/SMBG group showed the same trend as the whole group in 2019 and 2021. However, the effect of seasonal variation in HbA1c was lower in the MDI/isCGM group and the lowest in the SAP + CSII/isCGM group in 2019. The impact of emergency declaration on HbA1c level was small for the MDI/isCGM group and smaller for the SAP + CSII/isCGM group in 2021. The COVID-19 pandemic has affected the seasonal variation of HbA1c levels in T1D; the variation differed according to the treatment mode.

Newly developed type 1 diabetes after coronavirus disease 2019 vaccination: A case report.

The vaccine for the coronavirus disease 2019 (COVID-19) has been reported to potentially cause or worsen diabetes. A 73-year-old Japanese woman received two doses of Moderna COVID-19 vaccine. Four weeks after the second vaccination, her glycemic control began to deteriorate, and 8 weeks after the second vaccination, the patient was diagnosed with new-onset type 1 diabetes that was strongly positive for autoantibodies and showed a disease-susceptible human leukocyte antigen haplotype, DRB1*04:05:01-DQB1*04:01:01. The glucagon stimulation test suggested an insulin-dependent state, and induction of intensive insulin therapy brought about fair glycemic control. The time period from the COVID-19 vaccination to the development of type 1 diabetes was relatively longer than to the onset or exacerbation of type 2 diabetes, as previously reported, suggesting the complicated immunological mechanisms for the destruction of ß-cells associated with the vaccination. In recipients with the disease-susceptible haplotypes, one should be cautious about autoimmune responses for several months after the vaccination.

Enhancing Antigen Presentation and Inducing Antigen-Specific Immune Tolerance with Amphiphilic Peptides.

Ag-specific immunotherapy to restore immune tolerance to self-antigens, without global immune suppression, is a long-standing goal in the treatment of autoimmune disorders such as type 1 diabetes (T1D). However, vaccination with autoantigens such as insulin or glutamic acid decarboxylase have largely failed in human T1D trials. Induction and maintenance of peripheral tolerance by vaccination requires efficient autoantigen presentation by APCs. In this study, we show that a lipophilic modification at the N-terminal end of CD4+ epitopes (lipo-peptides) dramatically improves peptide Ag presentation. We designed amphiphilic lipo-peptides to efficiently target APCs in the lymph nodes by binding and trafficking with endogenous albumin. Additionally, we show that lipophilic modification anchors the peptide into the membranes of APCs, enabling a bivalent cell-surface Ag presentation. The s.c. injected lipo-peptide accumulates in the APCs in the lymph node, enhances the potency and duration of peptide Ag presentation by APCs, and induces Ag-specific immune tolerance that controls both T cell- and B cell-mediated immunity. Immunization with an amphiphilic insulin B chain 9-23 peptide, an immunodominant CD4+ T cell epitope in NOD mice, significantly suppresses the activation of T cells, increases inhibitory cytokine production, induces regulatory T cells, and delays the onset and lowers the incidence of T1D. Importantly, treatment with a lipophilic ß-cell peptide mixture delays progression to end-stage diabetes in acutely diabetic NOD mice, whereas the same doses of standard soluble peptides were not effective. Amphiphilic modification effectively enhances Ag presentation for peptide-based immune regulation of autoimmune diseases.

Enoxacin Up-Regulates MicroRNA Biogenesis and Down-Regulates Cytotoxic CD8 T-Cell Function in Autoimmune Cholangitis.

BACKGROUND AND AIMS: Primary biliary cholangitis (PBC) is a prototypical organ-specific autoimmune disease that is mediated by autoreactive T-cell attack and destruction of cholangiocytes. Despite the clear role of autoimmunity in PBC, immune-directed therapies have failed to halt PBC, including biologic therapies effective in other autoimmune diseases. MicroRNA (miRNA) dysregulation is implicated in the pathogenesis (PBC). In the dominant-negative TGF-ß receptor type II (dnTGFßRII) mouse model of PBC, autoreactive CD8 T cells play a major pathogenic role and demonstrate a striking pattern of miRNA down-regulation. Enoxacin is a small molecule fluoroquinolone that enhances miRNA biogenesis, partly by stabilizing the interaction of transactivation response RNA-binding protein with Argonaute (Ago) 2. APPROACH AND RESULTS: We hypothesized that correcting aberrant T-cell miRNA expression with enoxacin in dnTGFßRII mice could modulate autoreactive T-cell function and prevent PBC. Here, we show that liver-infiltrating dnTGFßRII CD8 T cells have significantly decreased levels of the miRNA biogenesis molecules prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and Ago2 along with significantly increased levels of granzyme B and perforin. Enoxacin treatment significantly up-regulated miRNAs in dnTGFßRII CD8 T cells and effectively treated autoimmune cholangitis in dnTGFßRII mice. Enoxacin treatment directly altered T cells both ex vivo and in vitro, resulting in altered memory subset numbers, decreased proliferation, and decreased interferon-γ production. Enoxacin significantly decreased CD8 T-cell expression of the transcription factor, Runx3, and significantly decreased perforin expression at both the mRNA and protein levels. CONCLUSIONS: Enoxacin increases miRNA expression in dnTGFßRII CD8 T cells, reduces CD8 T-cell pathogenicity, and effectively halted progression of autoimmune biliary disease. Targeting the miRNA pathway is a therapeutic approach to autoimmunity that corrects pathological miRNA abnormalities in autoreactive T cells.

Soluble CD137 Ameliorates Acute Type 1 Diabetes by Inducing T Cell Anergy.

We show here that soluble CD137 (sCD137), the alternately spliced gene product of Tnfsfr9, effectively treats acute type 1 diabetes (T1D) in nonobese diabetic (NOD) mice. sCD137 significantly delayed development of end-stage disease, preserved insulin+ islet beta cells, and prevented progression to end-stage T1D in some mice. We demonstrate that sCD137 induces CD4+ T cell anergy, suppressing antigen-specific T cell proliferation and IL-2/IFN-γ secretion. Exogenous IL-2 reversed the sCD137 anergy effect. sCD137 greatly reduces inflammatory cytokine production by CD8 effector memory T cells, critical mediators of beta cell damage. We demonstrate that human T1D patients have decreased serum sCD137 compared to age-matched controls (as do NOD mice compared to NOD congenic mice expressing a protective Tnfsfr9 allele), that human sCD137 is secreted by regulatory T cells (Tregs; as in mice), and that human sCD137 induces T cell suppression in human T cells. These findings provide a rationale for further investigation of sCD137 as a treatment for T1D and other T cell-mediated autoimmune diseases.

GLP-1 receptor agonist, liraglutide, ameliorates hepatosteatosis induced by anti-CD3 antibody in female mice.

AIMS: Hepatosteatosis is mainly induced by obesity and metabolic disorders, but various medications also induce hepatosteatosis. The administration of anti-CD3 antibody was shown to induce hepatosteatosis, but changes in lipid and glucose metabolism remain unclear. We investigated the mechanism of hepatosteatosis induced by anti-CD3 antibody and the effects of glucagon-like peptide-1 (GLP-1) receptor agonist that was recently shown to affect immune function in metabolic disorders. METHODS: Anti-CD3 antibody was administered to female BALB/c and C.B-17-scid mice with or without reconstitution by naïve CD4-positive splenocytes. Hepatic lipid content, serum lipid profile and glucose tolerance were evaluated. Splenic CD4-positive T lymphocytes were stimulated with the GLP-1R agonist, liraglutide, and cytokine production was measured. The effect of liraglutide on metabolic parameters in vivo was investigated in a T-cell activation-induced hepatosteatosis model. RESULTS: The administration of anti-CD3 antibody induced hepatosteatosis, hyperlipidemia, and glucose intolerance. C.B-17-scid mice reconstituted with CD4-positive T lymphocytes developed hepatosteatosis induced by anti-CD3 antibody. Liraglutide suppressed CD4-positive T lymphocyte cytokine expression in vitro and in vivo, and improved hepatosteatosis, glucose tolerance, and insulin sensitivity. CONCLUSIONS: Liraglutide suppressed the activation of CD4-positive T lymphocytes, and improved hepatosteatosis and metabolic disorders induced by T-cell activation in female mice.

Targeting innate immunity to downmodulate adaptive immunity and reverse type 1 diabetes.

Type 1 diabetes (T1D) is characterized by specific destruction of pancreatic insulin-producing beta cells accompanied by evidence of beta-cell-directed autoimmunity such as autoreactive T cells and islet autoantibodies (IAAs). Currently, T1D cannot be prevented or reversed in humans. T1D is easy to prevent in the nonobese diabetic (NOD) spontaneous mouse model but reversing new-onset T1D in mice is more difficult. Since the discovery of the T-cell receptor in the 1980s and the subsequent identification of autoreactive T cells directed toward beta-cell antigens (eg, insulin, glutamic acid decarboxylase), the dream of antigen-specific immunotherapy has dominated the field with its promise of specificity and limited side effects. While such approaches have worked in the NOD mouse, however, dozens of human trials have failed. Broader immunosuppressive approaches (originally cyclosporine, subsequently anti-CD3 antibody) have shown partial successes (e.g., prolonged C peptide preservation) but no major therapeutic efficacy or disease reversal. Human prevention trials have failed, despite the ease of such approaches in the NOD mouse. In the past 50 years, the incidence of T1D has increased dramatically, and one explanation is the "hygiene hypothesis", which suggests that decreased exposure of the innate immune system to environmental immune stimulants (e.g., bacterial products such as Toll-like receptor (TLR) 4-stimulating lipopolysaccharide [LPS]) dramatically affects the adaptive immune system and increases subsequent autoimmunity. We have tested the role of innate immunity in autoimmune T1D by treating acute-onset T1D in NOD mice with anti-TLR4/MD-2 agonistic antibodies and have shown a high rate of disease reversal. The TLR4 antibodies do not directly stimulate T cells but induce tolerogenic antigen-presenting cells (APCs) that mediate decreased adaptive T-cell responses. Here, we review our current knowledge and suggest future prospects for targeting innate immunity in T1D immunotherapy.

Bile acid binding resin prevents fat accumulation through intestinal microbiota in high-fat diet-induced obesity in mice.

BACKGROUND: Bile acid binding resin (BAR) absorbs intestinal bile acids, and improves obesity and metabolic disorders, but the precise mechanism remains to be clarified. Recent findings reveal that obesity is associated with skewed intestinal microbiota. Thus, we investigated the effect of BAR on intestinal microbiota and the role of microbiota in the prevention of obesity in high-fat diet-induced obesity in mice. PROCEDURES: Male Balb/c mice were fed a low-fat diet (LFD), high-fat diet (HFD), or HFD with BAR (HFD+BAR), and then metabolic parameters, caecal microbiota, and metabolites were investigated. The same interventions were conducted in germ-free and antibiotic-treated mice. MAIN FINDINGS: The frequency of Clostridium leptum subgroup was higher in both HFD-fed and HFD+BAR-fed mice than in LFD-fed mice. The frequency of Bacteroides-Prevotella group was lower in HFD-fed mice than in LFD-fed mice, but the frequency was higher in HFD+BAR-fed mice than in HFD-fed mice. Caecal propionate was lower in HFD-fed mice than in LFD-fed mice, and higher in HFD+BAR-fed mice than in HFD-fed mice. HFD+BAR-fed mice showed lower adiposity than HFD-fed mice, and the reduction was not observed in germ-free or antibiotic-treated mice. Colonized germ-free mice showed a reduction in adiposity by BAR administration. Energy expenditure was lower in HFD-fed mice and higher in HFD+BAR-fed mice, but the increments induced by administration of BAR were not observed in antibiotic-treated mice. CONCLUSIONS: Modulation of intestinal microbiota by BAR could be a novel therapeutic approach for obesity.

CD137 Plays Both Pathogenic and Protective Roles in Type 1 Diabetes Development in NOD Mice.

We previously reported that CD137 (encoded by Tnfrsf9) deficiency suppressed type 1 diabetes (T1D) progression in NOD mice. We also demonstrated that soluble CD137 produced by regulatory T cells contributed to their autoimmune-suppressive function in this model. These results suggest that CD137 can either promote or suppress T1D development in NOD mice depending on where it is expressed. In this study, we show that NOD.Tnfrsf9-/- CD8 T cells had significantly reduced diabetogenic capacity, whereas absence of CD137 in non-T and non-B cells had a limited impact on T1D progression. In contrast, NOD.Tnfrsf9-/- CD4 T cells highly promoted T1D development. We further demonstrated that CD137 was important for the accumulation of ß cell-autoreactive CD8 T cells but was dispensable for their activation in pancreatic lymph nodes. The frequency of islet-infiltrating CD8 T cells was reduced in NOD.Tnfrsf9-/- mice in part because of their decreased proliferation. Furthermore, CD137 deficiency did not suppress T1D development in NOD mice expressing the transgenic NY8.3 CD8 TCR. This suggests that increased precursor frequency of ß cell-autoreactive CD8 T cells in NY8.3 mice obviated a role for CD137 in diabetogenesis. Finally, blocking CD137-CD137 ligand interaction significantly delayed T1D onset in NOD mice. Collectively, our results indicate that one important diabetogenic function of CD137 is to promote the expansion and accumulation of ß cell-autoreactive CD8 T cells, and in the absence of CD137 or its interaction with CD137 ligand, T1D progression is suppressed.

Time-dependent changes in insulin requirement for maternal glycemic control during antenatal corticosteroid therapy in women with gestational diabetes: a retrospective study.

Though recommended for pregnant women at risk of preterm birth to improve perinatal outcomes, antenatal corticosteroid (ACS) treatment can cause maternal hyperglycemia, especially in cases of glucose intolerance. A standardized protocol for preventing hyperglycemia during ACS treatment remains to be established. We herein retrospectively investigated the time-dependent changes in insulin dose required for maternal glycemic control during ACS treatment in gestational diabetes (GDM). Twelve singleton pregnant women with GDM who received 12 mg of betamethasone intramuscularly twice 24 hours apart were included in this analysis. Of those, eight also received ritodrine hydrochloride for preterm labor. The blood glucose levels were maintained at 70-120 mg/dL with continuous intravenous infusion of insulin and nothing by mouth for 48 hours after the first betamethasone administration. After the first dose of betamethasone, the insulin dosage needed for glycemic control gradually increased and reached a maximum (6.6 ± 5.8 units/hr) at 10 hours, then, decreased to 4.1 ± 1.5 units/hr at 24 hours. Similar changes in the insulin requirement were found after the second betamethasone dose (the maximum insulin dosage: 5.5 ± 1.6 units/hr at 9 hours following the second administration). Women treated with ritodrine hydrochloride needed more insulin, than those without ritodrine hydrochloride treatment (130.8 ± 15.0 vs. 76.8 ± 15.2 units/day, respectively, p < 0.05). Our data indicated that the requirement for insulin is highest 9-10 hours after each dose of betamethasone. When GDM is treated with ACS, levels of blood glucose should be carefully monitored, especially in patients treated with ritodrine hydrochloride.

Bile acid binding resin improves hepatic insulin sensitivity by reducing cholesterol but not triglyceride levels in the liver.

AIMS: Bile acid binding resin (BAR) improves glycaemic control in patients with type 2 diabetes. Although the mechanism is hypothesised to involve the clearance of excess hepatic triglyceride, this hypothesis has not been examined in appropriately designed studies. Therefore, we investigated whether reduced hepatic triglyceride deposition is involved in BAR-mediated improvements in glycaemic control in spontaneous fatty liver diabetic mice without dietary interventions. METHODS: Male 6-week-old fatty liver Shionogi (FLS) mice were fed a standard diet without or with 1.5% BAR (colestilan) for 6 weeks. Glucose tolerance, insulin sensitivity, hepatic lipid content, and gene expression were assessed. A liver X receptor (LXR) agonist was also administered to activate the LXR pathway. We also retrospectively analysed the medical records of 21 outpatients with type 2 diabetes who were treated with colestilan for ≥6 months. RESULTS: BAR enhanced glucose tolerance and insulin sensitivity in FLS mice without altering fat mass. BAR improved hepatic insulin sensitivity, increased IRS2 expression, and decreased SREBP expression. BAR reduced hepatic cholesterol levels but not hepatic triglyceride levels. BAR also reduced the expression of LXR target genes, and LXR activation abolished the BAR-mediated improvements in glycaemic control. Colestilan significantly lowered serum cholesterol levels and improved glycaemic control in patients with type 2 diabetes. CONCLUSIONS: BAR improved hepatic insulin resistance in FLS mice by reducing hepatic cholesterol without affecting hepatic triglyceride levels or body fat distribution. Our study revealed that BAR improves glycaemic control at least in part by downregulating the hepatic cholesterol-LXR-IRS2 pathway.

A case of hypoglycemic hemiparesis and literature review.

An 89-year-old man with diabetes treated with metformin 500 mg/day and glimepiride 4 mg/day was hospitalized because of hypoglycemic right hemiparesis and dysarthria (casual glucose value 1.8 mmol/L), which resolved quickly following administration of 40 mL of 40% dextrose. Hemiparesis is a rare symptom (4.2%) of hypoglycemia. There are about 200 case reports of hypoglycemic hemiparesis. The average glucose level at which hemiparesis developed was 1.8 mmol/L. Right-sided hemiparesis predominated (R 66%; L 34%). On imaging studies, abnormal findings were frequently observed in the internal capsule or splenium of the corpus callosum. The mechanism of hemiparesis is not fully understood. The existence of cases in which hypoglycemia cannot be distinguished from stroke on imaging studies suggests the importance of measurement of the blood glucose level when the symptoms of stroke are first recognized.

GAD-reactive T cells were mainly detected in autoimmune-related type 1 diabetic patients with HLA DR9.

Type 1 diabetes mellitus (T1DM) is considered to be a T cell-mediated disease, and many reports suggest that some HLA types, especially HLA DR4 and DR9, convey susceptibility to T1DM in Japanese. We investigated the association between T cell reactivity against GAD and HLA types in "islet-associated autoantibody-positive" T1DM in Japanese. Blood samples were obtained from 36 "autoantibody-positive" type 1 diabetic patients with HLA DR4 or DR9 and 23 type 2 diabetic patients with HLA DR4 or DR9 as controls. They were divided into three groups, DR4/9, DR4/X, and DR9/X groups. In each HLA type group, GAD-reactive IFN-gamma-producing CD4(+) cells were assessed by means of intracellular cytokine staining for flow cytometry. Type 1 diabetic patients with HLA DR9/X had significantly higher numbers of GAD-reactive IFN-gamma-producing CD4(+) cells as compared to type 1 diabetic patients with DR4/X or DR4/9 (P < 0.05) and all type 2 diabetic patients. There was no significant difference in the number of GAD-reactive IFN-gamma-producing CD4(+) cells between type 1 diabetic and type 2 diabetic patients belonging to the DR4/X and DR4/9 groups. There was an association between T cell reactivity against GAD and HLA DR9 in Japanese type 1 diabetes.