Protein acylations induced by a ketogenic diet demonstrate diverse patterns depending on organs and differ between histones and global proteins

An essential ketone body, β-hydroxybutyrate (BOHB), plays various roles in physiological regulations via protein acylations such as lysine acetylation and β-hydroxybutyrylation. Here, to understand how BOHB systemically regulates acylations from an overarching perspective, we administered a ketogenic diet to mice to increase BOHB concentration and examined acylations. We found that global acetylation and β-hydroxybutyrylation dramatically increase in various organs except for the brains, where the increase was much smaller than in the other organs. Interestingly, we observe no increase in histone acetylation in the organs where significant global protein acetylation occurs despite a substantial rise in histone β-hydroxybutyrylation. Finally, we compared the transcriptome data of the mice's liver after the ketogenic diet to the public databases, showing that upregulated genes are enriched in those related to histone β-hydroxybutyrylation in starvation. Our data indicate that a ketogenic diet induces diverse patterns of acylations depending on organs and protein localizations, suggesting that different mechanisms regulate acylations and that the ketogenic diet is associated with starvation in terms of protein modifications.

Protocol of a Prospective Observational Study on Lifestyle and Quality of Life in Adults with Type 1 Diabetes in Japan

INTRODUCTION

Recent studies have shown that the quality of life (QOL) of people living with type 1 diabetes (T1D) is poor and must be improved. However, the living situation and QOL of adults living with T1D in Japan have not been fully clarified. This study will examine their lifestyle, QOL, and clinical situation, as well as the relationships between them.

METHODS

This is a prospective, 5-year follow-up observational study. Between December 2019 and September 2021, we enrolled adults in Japan who were living with T1D and receiving insulin therapy, and are acquiring longitudinal clinical data and the responses to seven questionnaires regarding lifestyle and QOL. The primary study outcomes are (1) the relationship between Problem Areas in Diabetes (PAID) scores and various factors including demographic data, clinical characteristics, medical history, lifestyle habits, treatment history, biochemical data, and the scores of questionnaires; and (2) the relationship between Beck Depression Inventory (BDI)-II scores and various factors aforementioned. The secondary outcomes are the relationships between various factors aforementioned and each of the following: (1) blood glucose control, (2) blood lipid control, (3) dietary patterns, (4) fear of hypoglycemia, (5) sleep patterns, and (6) physical activity.

PLANNED OUTCOME

We registered 352 participants. The median age was 49 (41-63) years, and the median duration of T1D was 13 (8-20) years. All the results will be available in 2026. We expect to clarify the factors associated with decreased QOL, and that this knowledge will contribute to improving QOL in adults in Japan who are living with T1D and receiving insulin therapy.

TRIAL REGISTRATION

Clinical Trials.gov identifier, UMIN000044088.

Regulation of urea cycle by reversible high-stoichiometry lysine succinylation

The post-translational modification lysine succinylation is implicated in the regulation of various metabolic pathways. However, its biological relevance remains uncertain due to methodological difficulties in determining high-impact succinylation sites. Here, using stable isotope labelling and data-independent acquisition mass spectrometry, we quantified lysine succinylation stoichiometries in mouse livers. Despite the low overall stoichiometry of lysine succinylation, several high-stoichiometry sites were identified, especially upon deletion of the desuccinylase SIRT5. In particular, multiple high-stoichiometry lysine sites identified in argininosuccinate synthase (ASS1), a key enzyme in the urea cycle, are regulated by SIRT5. Mutation of the high-stoichiometry lysine in ASS1 to succinyl-mimetic glutamic acid significantly decreased its enzymatic activity. Metabolomics profiling confirms that SIRT5 deficiency decreases urea cycle activity in liver. Importantly, SIRT5 deficiency compromises ammonia tolerance, which can be reversed by the overexpression of wild-type, but not succinyl-mimetic, ASS1. Therefore, lysine succinylation is functionally important in ammonia metabolism.

Low Handgrip Strength (Possible Sarcopenia) With Insulin Resistance Is Associated With Type 2 Diabetes Mellitus

Context

Older adults with sarcopenic obesity are at high risk for type 2 diabetes mellitus (T2DM). However, few East Asians have sarcopenic obesity. Since many East Asians have insulin resistance (IR) without obesity, it is possible that older East Asians with sarcopenia and IR might be at high risk for T2DM. However, this relationship has not been studied.

Methods

This cross-sectional study included 1629 older adults aged 65 to 84 years registered in the Bunkyo Health Study. All underwent a 75-g oral glucose tolerance test and handgrip strength measurement. Participants were classified into 4 groups by possible sarcopenia (handgrip strength <28 kg in men and <18 kg in women) and IR status (triglyceride glucose [TyG] index ≥8.79 for men and ≥8.62 for women [third quartile]). Modified Poisson regression was used to estimate relative risk (RR) and 95% CIs for T2DM with adjustment for confounding factors.

Results

The mean age was 73.1 ± 5.4 years. T2DM was diagnosed in 212 (13.0%) participants. After adjusting for age, sex, body mass index, use of lipid-lowering medications, hypertension, and cardiovascular disease, possible sarcopenia and IR were associated with T2DM, with their coexistence showing a notably stronger association (control: RR, 1.00 [Reference]; possible sarcopenia: RR, 1.55 [95% CI, 1.04-2.30]; IR: RR, 2.69 [95% CI, 1.99-3.65]; and IR possible sarcopenia: RR, 4.76 [95% CI, 3.34-6.79]).

Conclusion

Possible sarcopenia based on low handgrip strength and IR based on the TyG index are independently associated with T2DM in older Japanese individuals. Their coexistence shows a particularly strong association with T2DM.

Fat Accumulation and Elevated Free Fatty Acid Are Associated With Age-Related Glucose Intolerance: Bunkyo Health Study

Context

Older adults have a high prevalence of new-onset diabetes, often attributed to age-related decreases in insulin sensitivity and secretion. It remains unclear whether both insulin sensitivity and secretion continue to deteriorate after age 65.

Objective

To investigate the effects of aging on glucose metabolism after age 65 and to identify its determinants.

Methods

This cross-sectional study involved 1438 Japanese older adults without diabetes. All participants underwent a 75-g oral glucose tolerance test (OGTT). Body composition and fat distribution were measured with dual-energy X-ray absorptiometry and magnetic resonance imaging. Participants were divided into 4 groups by age (65-69, 70-74, 75-79, and 80-84 years) to compare differences in metabolic parameters.

Results

Mean age and body mass index were 73.0 ± 5.4 years and 22.7 ± 3.0 kg/m2. The prevalence of newly diagnosed diabetes increased with age. Fasting glucose, fasting insulin, the area under the curve (AUC)-insulin/AUC-glucose and insulinogenic index were comparable between groups. AUC-glucose and AUC-insulin during OGTT were significantly higher and Matsuda index and disposition index (Matsuda index · AUC-insulin/AUC-glucose) were significantly lower in the age 80-84 group than in the age 65-69 group. Age-related fat accumulation, particularly increased visceral fat area (VFA), and elevated free fatty acid (FFA) levels were observed. Multiple regression revealed strong correlations of both Matsuda index and disposition index with VFA and FFA.

Conclusion

Glucose tolerance declined with age in Japanese older adults, possibly due to age-related insulin resistance and β-cell deterioration associated with fat accumulation and elevated FFA levels.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Novel time-resolved reporter mouse reveals spatial and transcriptional heterogeneity during alpha cell differentiation

AIMS/HYPOTHESIS

Glucagon-expressing pancreatic alpha cells have attracted much attention for their plasticity to transdifferentiate into insulin-producing beta cells; however, it remains unclear precisely when, and from where, alpha cells emerge and what regulates alpha cell fate. We therefore explored the spatial and transcriptional heterogeneity of alpha cell differentiation using a novel time-resolved reporter system.

METHODS

We established the mouse model, 'Gcg-Timer', in which newly generated alpha cells can be distinguished from more-differentiated cells by their fluorescence. Fluorescence imaging and transcriptome analysis were performed with Gcg-Timer mice during the embryonic and postnatal stages.

RESULTS

Fluorescence imaging and flow cytometry demonstrated that green fluorescence-dominant cells were present in Gcg-Timer mice at the embryonic and neonatal stages but not after 1 week of age, suggesting that alpha cell neogenesis occurs during embryogenesis and early neonatal stages under physiological conditions. Transcriptome analysis of Gcg-Timer embryos revealed that the mRNAs related to angiogenesis were enriched in newly generated alpha cells. Histological analysis revealed that some alpha cells arise close to the pancreatic ducts, whereas the others arise away from the ducts and adjacent to the blood vessels. Notably, when the glucagon signal was suppressed by genetic ablation or by chemicals, such as neutralising glucagon antibody, green-dominant cells emerged again in adult mice.

CONCLUSIONS/INTERPRETATION

Novel time-resolved analysis with Gcg-Timer reporter mice uncovered spatiotemporal features of alpha cell neogenesis that will enhance our understanding of cellular identity and plasticity within the islets.

DATA AVAILABILITY

Raw and processed RNA sequencing data for this study has been deposited in the Gene Expression Omnibus under accession number GSE229090.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Diabetic ketoacidosis due to a sensor defect of FreeStyle Libre: A case report

The FreeStyle Libre Flash Glucose Monitoring System allows users to obtain sensor glucose values by scanning with the reader or their mobile phone. We report a case of a 59-year-old man with type 1 diabetes mellitus who developed diabetic ketoacidosis due to a sensor defect. After replacing the sensor with a new one, the glucose value shown in the device was much lower than usual, which made him consider that he was hypoglycemic. Accordingly, he reduced his insulin dose and eventually developed diabetic ketoacidosis. He was unaware of the discrepancy due to the lack of self-monitoring of his blood glucose, although he was educated to do. In sum, glucose monitoring with the FreeStyle Libre is helpful; however, it is necessary to remind the patient that a sensor defect leading to a severe complication frequently happens.

Establishment of Pancreatic β-Cell-Specific Gene Knockout System Based on CRISPR-Cas9 Technology With AAV8-Mediated gRNA Delivery

The Cre-loxP system provides valuable resources to analyze the importance of tissue-specific gene knockout (KO), including pancreatic β-cells associated with the pathogenesis of diabetes. However, it is expensive and time consuming to generate transgenic mice harboring floxed genes of interest and cross them with cell-specific Cre expression mice. We establish a βCas9 system with mice expressing Cas9 in pancreatic β-cells and adeno-associated virus 8 (AAV8)-mediated guide RNA (gRNA) delivery based on CRISPR-Cas9 technology to overcome those shortcomings. Interbreeding CAG-loxP-STOP-loxP (LSL)-Cas9 with Ins1-Cre mice generates normal glucose-tolerant βCas9 mice expressing Cas9 with fluorescent reporter EGFP specifically in β-cells. We also show significant β-cell-specific gene KO efficiency with AAV8-mediated delivery of gRNA for EGFP reporter by intraperitoneal injection in the mice. As a proof of concept, we administered AAV8 to βCas9 mice for expressing gRNA for Pdx1, a culprit gene of maturity-onset diabetes of the young 4. As reported previously, we demonstrate that those mice show glucose intolerance with transdifferentiation of Pdx1 KO β-cells into glucagon-expressing cells. We successfully generated a convenient β-cell-specific gene KO system with βCas9 mice and AAV8-mediated gRNA delivery.

ARTICLE HIGHLIGHTS

Genome-wide screening for regulators of degradation of insulin secretory granules with a fluorescent reporter

Insulin is essential in controlling blood glucose levels, and its synthesis and secretion have been well investigated. In contrast, how insulin secretory granules (ISGs) are degraded in pancreatic beta cells remains largely unknown. To clarify the mechanism, we constructed a fluorescent reporter detecting ISG degradation, where EGFP and mCherry are tandemly conjugated to a cytoplasmic region of ZnT8, an ISG membrane-localized protein. Depletion of serum and amino acid stimulated lysosomal ISG degradation detected with the reporter. Next, with MIN6 cells expressing Cas9 and the reporter, we investigated the involvement of conventional Atg5/7-dependent autophagy to show that it is dispensable for the ISG degradation process. Finally, we performed genome-wide screening by enriching the cells lacking the ISG degradation and showed that pathways regulating autophagy are not identified. These results suggest that alternative degradation in lysosomes, instead of conventional autophagy, may be involved in ISG degradation.

Monitoring autophagic flux in vivo revealed its physiological response and significance of heterogeneity in pancreatic beta cells

Autophagy plays an essential role in preserving cellular homeostasis in pancreatic beta cells. However, the extent of autophagic flux in pancreatic islets induced in various physiological settings remains unclear. In this study, we generate transgenic mice expressing pHluorin-LC3-mCherry reporter for monitoring systemic autophagic flux by measuring the pHluorin/mCherry ratio, validating them in the starvation and insulin-deficient model. Our findings reveal that autophagic flux in pancreatic islets enhances after starvation, and suppression of the flux after short-term refeeding needs more prolonged re-starvation in islets than in the other insulin-targeted organs. Furthermore, heterogeneity of autophagic flux in pancreatic beta cells manifests under insulin resistance, and intracellular calcium influx by glucose stimulation increases more in high- than low-autophagic flux beta cells, with differential gene expression, including lipoprotein lipase. Our pHluorin-LC3-mCherry mice enable us to reveal biological insight into heterogeneity in autophagic flux in pancreatic beta cells.

Physical inactivity induces insulin resistance in plantaris muscle through protein tyrosine phosphatase 1B activation in mice

Inactivity causes insulin resistance in skeletal muscle and exacerbates various lifestyle-related diseases. We previously found that 24-h hindlimb cast immobilization (HCI) of the predominantly slow-twitch soleus muscle increased intramyocellular diacylglycerol (IMDG) and insulin resistance by activation of lipin1, and HCI after a high-fat diet (HFD) further aggravated insulin resistance. Here, we investigated the effects of HCI on the fast-twitch-predominant plantaris muscle. HCI reduced the insulin sensitivity of plantaris muscle by approximately 30%, and HCI following HFD dramatically reduced insulin sensitivity by approximately 70% without significant changes in the amount of IMDG. Insulin-stimulated phosphorylation levels of insulin receptor (IR), IR substrate-1, and Akt were reduced in parallel with the decrease in insulin sensitivity. Furthermore, tyrosine phosphatase 1B (PTP1B), a protein known to inhibit insulin action by dephosphorylating IR, was activated, and PTP1B inhibition canceled HCI-induced insulin resistance. In conclusion, HCI causes insulin resistance in the fast-twitch-predominant plantaris muscle as well as in the slow-twitch-predominant soleus muscle, and HFD potentiates these effects in both muscle types. However, the mechanism differed between soleus and plantaris muscles, since insulin resistance was mediated by the PTP1B inhibition at IR in plantaris muscle.

A 7 day inpatient diabetes education program improves quality of life and glycemic control 12 months after discharge

AIMS

For long-term management of diabetes, patients with type 2 diabetes mellitus require a high level of treatment adherence, which is associated with treatment satisfaction and their quality of life (QOL). To achieve it, patient education about diabetes self-management is essential. We routinely conduct a 7 day inpatient diabetes education program and administer the diabetes treatment-related (DTR)-QOL questionnaire to all participants, both before admission and at discharge. Here, we investigated whether our program improves QOL and post-discharge glycemic control.

MATERIALS AND METHODS

This retrospective study utilized data from patients with type 2 diabetes mellitus who participated in our program between July 2017 and March 2020 and who had been treated in our outpatient department for more than 1 year. We evaluated the relationship between at admission and at discharge diabetes treatment-related quality of life scores and glycemic control after discharge.

RESULTS

Data from 140 patients were analyzed in this study, which showed a significant improvement in the total, 'Anxiety and dissatisfaction with treatment', and 'Satisfaction-with-treatment' scores. A significant improvement was evident in HbA1c at 12 months after discharge. Multiple regression analysis showed that HbA1c after 12 months was independently associated with gender, duration of diabetes, and HbA1c at admission.

CONCLUSIONS

Our program effectively improves quality of life and post-discharge glycemic control in patients with type 2 diabetes mellitus. It is particularly effective in patients of the male gender, with a shorter duration of diabetes mellitus and higher HbA1c at admission.

Establishment of a novel NFAT-GFP reporter platform useful for the functional avidity maturation of HLA class II-restricted TCRs

CD4⁺ T cells that recognize antigenic peptides presented on HLA class II are essential for inducing an optimal anti-tumor immune response, and adoptive transfer of tumor antigen-specific TCR-transduced CD4⁺ T cells with high responsiveness against tumor is a promising strategy for cancer treatment. Whereas a precise evaluation method of functional avidity, an indicator of T cell responsiveness against tumors, has been established for HLA class I-restricted TCRs, it remains unestablished for HLA class II-restricted TCRs. In this study, we generated a novel platform cell line, CD4-2D3, in which GFP reporter was expressed by NFAT activation via TCR signaling, for correctly evaluating functional avidity of HLA class II-restricted TCRs. Furthermore, using this platform cell line, we succeeded in maturating functional avidity of an HLA class II-restricted TCR specific for a WT1-derived helper peptide by substituting amino acids in complementarity determining region 3 (CDR3) of the TCR. Importantly, we demonstrated that transduction of an avidity-maturated TCR conferred strong cytotoxicity against WT1-expressing leukemia cells on CD4⁺ T cells, compared to that of its original TCR. Thus, CD4-2D3 cell line should be useful not only to evaluate TCR functional avidity in HLA class II-restricted TCRs but also to screen appropriate TCRs for clinical applications such as cancer immunotherapy.

The Effect of Long-Term Inorganic Iodine on Intrathyroidal Iodothyronine Content and Gene Expression in Mice with Graves' Hyperthyroidism

Background: The main molecular mechanism underlying acute suppression of iodine organification in normal thyroids after an excessive iodine load, that is, the Wolff-Chaikoff effect, is assumed to be suppression of iodine oxidation and iodothyronine synthesis. However, the mechanism underlying chronic antithyroid action of inorganic iodine in Graves' disease is not fully understood. Using a mouse model of Graves' hyperthyroidism, we examined changes in iodothyronine content and gene expression profiles in the thyroid glands after inorganic iodine loading. Materials and Methods: Graves' hyperthyroidism was induced and maintained in BALB/c mice by repeated immunizations of recombinant adenovirus expressing the human thyrotropin (TSH) receptor A-subunit. Hyperthyroid mice were left untreated (GD-C; n = 8) or treated with inorganic iodine for 12 weeks (GD-NaI; n = 8). We used unimmunized BALB/c mice as a control group (n = 10). In each mouse, serum thyroxine (T4) levels were measured with enzyme-linked immunosorbent assay (ELISA) at 4-week intervals. The intrathyroidal iodothyronine content and gene expression levels were, respectively, evaluated by mass spectrometry and RNA sequencing (RNA-seq) at the end of the experimental period. Results: Serum T4 levels in the GD-C group remained higher than in the control group, whereas those in the GD-NaI group declined to normal levels during the experimental period. Intrathyroidal triiodothyronine (T3), reverse T3 (rT3), and T4 contents in the GD-C group were higher than the control group, and rT3 and T4 were further increased in the GD-NaI group. The observed alterations in iodothyronine levels in the thyroid and sera may be explained by altered expression levels of genes for iodothyronine biosynthetic molecules, their transporter, and deiodinases. Conclusion: In this mouse model of hyperthyroidism, higher intrathyroidal accumulation of T4 and reduced gene expression data of iodothyronine transporters in the GD-NaI group suggest that chronic antithyroid action of iodine in Graves' disease involves suppression of hormone secretion.

STAT3 suppression and β-cell ablation enhance α-to-β reprogramming mediated by Pdx1

As diabetes results from the absolute or relative deficiency of insulin secretion from pancreatic β cells, possible methods to efficiently generate surrogate β cells have attracted a lot of efforts. To date, insulin-producing cells have been generated from various differentiated cell types in the pancreas, such as acinar cells and α cells, by inducing defined transcription factors, such as PDX1 and MAFA, yet it is still challenging as to how surrogate β cells can be efficiently generated for establishing future regenerative therapies for diabetes. In this study, we demonstrated that the exogenous expression of PDX1 activated STAT3 in α cells in vitro, and STAT3-null PDX1-expressing α cells in vivo resulted in efficient induction of α-to-β reprogramming, accompanied by the emergence of α-cell-derived insulin-producing cells with silenced glucagon expression. Whereas β-cell ablation by alloxan administration significantly increased the number of α-cell-derived insulin-producing cells by PDX1, STAT3 suppression resulted in no further increase in β-cell neogenesis after β-cell ablation. Thus, STAT3 modulation and β-cell ablation nonadditively enhance α-to-β reprogramming induced by PDX1, which may lead to the establishment of cell therapies for curing diabetes.

Identifying antibiotics based on structural differences in the conserved allostery from mitochondrial heme-copper oxidases

Antimicrobial resistance (AMR) is a global health problem. Despite the enormous efforts made in the last decade, threats from some species, including drug-resistant Neisseria gonorrhoeae, continue to rise and would become untreatable. The development of antibiotics with a different mechanism of action is seriously required. Here, we identified an allosteric inhibitory site buried inside eukaryotic mitochondrial heme-copper oxidases (HCOs), the essential respiratory enzymes for life. The steric conformation around the binding pocket of HCOs is highly conserved among bacteria and eukaryotes, yet the latter has an extra helix. This structural difference in the conserved allostery enabled us to rationally identify bacterial HCO-specific inhibitors: an antibiotic compound against ceftriaxone-resistant Neisseria gonorrhoeae. Molecular dynamics combined with resonance Raman spectroscopy and stopped-flow spectroscopy revealed an allosteric obstruction in the substrate accessing channel as a mechanism of inhibition. Our approach opens fresh avenues in modulating protein functions and broadens our options to overcome AMR.

Effects of Interfacial Interactions on Electrocatalytic Activity of Cytochrome c Oxidase in Biomimetic Lipid Membranes on Gold Electrodes

Effects of interfacial interactions on the electrocatalytic activity of protein-tethered bilayer lipid membranes (ptBLMs) containing cytochrome c oxidase (CcO) for the oxygen reduction reaction are studied by using protein film electrochemistry and surface-enhanced infrared absorption (SEIRA) spectroscopy. Mammalian CcO was immobilized on a gold electrode via self-assembled monolayers (SAMs) of mixed alkanethiols. The protein orientation on the electrode is controlled by SAM-CcO interactions and is critical to the cytochrome c (cyt c) binding. The CcO-phospholipid and CcO-cyt c interactions modulate the electrocatalytic activity of CcO, and more densely packed ptBLMs show higher electrocatalytic activity. Our study indicates that spectroscopic and electrochemical studies of ptBLMs can provide insights into the effects of relatively weak protein-protein and protein-lipid interactions on the enzymatic activity of transmembrane enzymes.

POS1196 SARS-CoV-2 VACCINE ACCEPTANCE AND ASSOCIATED PSYCHOLOGICAL FACTORS IN PATIENTS WITH RHEUMATIC AND MUSCULOSKELETAL DISEASES

Background

The mortality rate of coronavirus disease 2019 (COVID-19) in patients with rheumatic and musculoskeletal disease (RMD) is as high as approximately 10% [1]. Therefore, vaccination promotion is a critical issue. However, there are few reports on the psychological aspects of patient vaccine acceptance.

Objectives

To investigate the intention of patients with RMD to receive the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine and explore the psychological factors related to vaccine acceptance.

Methods

We conducted a questionnaire-based survey of 406 outpatients with RMD at Shiga General Hospital from July to October 2021. The questionnaire included the following sections: (1) vaccination status; (2) expectation of susceptibility to severe COVID-19; (3) expectation of vaccine efficacy; and (4) anxiety about the vaccine, which included concerns on I) the diminishing effect of the vaccine due to current treatment and II) the influence of vaccination on: i) primary disease status, ii) treatment, and iii) adverse reaction.

Results

There were 305 vaccinated and 101 unvaccinated individuals. Unvaccinated individuals were classified into the acceptance group (n=60) and hesitancy group (n=41) according to their vaccination status (Figure 1).

Figure 1.

SARS-CoV-2 vaccination status (n=406)

We compared the backgrounds and awareness of the patients on vaccination between the two groups. Univariate analysis did not show any difference in the backgrounds. The expectation of susceptibility to severe COVID-19 was similar in both groups. There were also no significant differences in the vaccine-related anxiety levels. However, the expectation of vaccine efficacy was higher in the acceptance group and significantly influenced vaccination intention as revealed by multivariate analyses (Table 1).

Table 1.

Awareness towards COVID-19 and SARS-CoV-2 vaccine associated with vaccination intention

Awareness towards COVID-19 and SARS-CoV-2 vaccineAcceptance(N=60)Hesitancy(N=41)UnivariateAnalysis§Multivariate Analysis||Median[IQR]Median[IQR]p-valuep-valueExpectation of susceptibility to severe COVID-19*2.0[1.0-3.0]2.0[1.5-2.5]0.84720.3440Expectation of vaccine efficacy†3.0[3.0-3.0]2.0[1.0-3.0]<0.0001¶<0.0001**Concerns about the diminishing effect of the vaccine due to current treatment‡2.0[1.0-3.0]3.0[2.0-3.0]0.04750.3600Concerns about the effect of vaccination on treatment‡3.0[1.0-3.0]3.0[2.0-4.0]0.01280.6232Concern about the effect of vaccination on primary disease status‡3.0[1.0-3.0]3.0[2.0-3.0]0.05760.7134Concern about the effect of vaccination on adverse reaction‡3.0[3.0-3.0]3.0[3.0-4.0]0.00930.8335

*0: Less likely to become severe~3: Very likely to become severe, †0: Not expected at all~4: Highly expected, ‡0: Not concerned at all ~4:Very concerned

§Pearson’s chi-square test or Wilcoxon test, ||Nominal logistic regression analysis, ¶ p<0.008 (after Bonferroni correction), ** p<0.05.

Conclusion

The perception of vaccine efficacy is strongly correlated with vaccine acceptance. In order to promote vaccination in patients with RMDs, this study suggests that emphasizing the efficacy of the vaccine may be more effective than alleviating anxiety about the adverse effects of the vaccine.

References

[1]Strangfeld, A. et al. Ann. Rheum. Dis. 2021; 80: 930–942.

Disclosure of Interests

Haruka Sugawara: None declared, Hiroshi Doi: None declared, Takeshi Iwasaki: None declared, Yoichi Nakayama: None declared, Yuri Nishida: None declared, Yoshie Gon: None declared, Masaki Kamakura: None declared, Kenshi Ohbori: None declared, Naoko Sakane: None declared, Naomi Nakamura: None declared, Takahiko Utsumi: None declared, Akio Morinobu Speakers bureau: Eli Lilly Japan K.K., Ono Pharmaceutical Co., Pfizer Inc., UCB Japan, AbbVie G.K., Asahi Kasei Pharma., and Chugai Pharmaceutical Co. Ltd., Grant/research support from: Eli Lilly Japan K.K., Ono Pharmaceutical Co., Pfizer Inc., UCB Japan, AbbVie G.K., Asahi Kasei Pharma., and Chugai Pharmaceutical Co. Ltd.

Genetic ablation of p62/SQSTM1 demonstrates little effect on pancreatic β-cell function under autophagy deficiency

Autophagy is known to play an essential role in intracellular quality control through the degradation of damaged organelles and components. We previously demonstrated that β-cell-specific autophagy deficient mice, which lack Atg7, exhibited impaired glucose tolerance, accompanied by the accumulation of sequestosome 1/p62 (hereafter referred to as p62). Whereas p62 has been reported to play essential roles in regulating cellular homeostasis in the liver and adipose tissue, we previously showed that β-cell-specific p62 deficiency does not cause any apparent impairment in glucose metabolism. In the present study, we investigated the roles of p62 in β cells under autophagy-deficient conditions, by simultaneously inactivating both Atg7 and p62 in a β-cell specific manner. Whereas p62 accumulation was substantially reduced in the islets of Atg7 and p62 double-deficient mice, glucose tolerance and insulin secretion were comparable to Atg7 single-deficient mice. Taken together, these findings suggest that the p62 accumulation appears to have little effect on β-cell function under conditions of autophagy inhibition.

Cumulative autophagy insufficiency in mice leads to progression of β-cell failure

Autophagy is known to play a pivotal role in β-cell function. While the lifelong inhibition of autophagy through Atg7 deletion in β cells has been demonstrated to lead to impaired glucose tolerance together with β-cell dysfunction, the temporal association between autophagy inhibition and β-cell dysfunction remains unclear. To address such questions, inducible β-cell-specific Atg7-knockout (iβAtg7^KO) mice were generated, and autophagy inhibition was induced for two different time durations. Whereas 2 weeks of Atg7 ablation was sufficient to induce autophagy deficiency, confirmed by the accumulation of p62, iβAtg7^KO mice exhibited normal glucose tolerance. In contrast, prolonged autophagy deficiency for 6 weeks resulted in glucose intolerance together with impaired insulin secretion. Direct mRNA sequencing and pathway analysis revealed that the gene set associated with insulin secretion was downregulated only after the 6-week prolonged autophagy inhibition. Furthermore, we identified a novel gene, Sprr1a, which was expressed at more than 50-fold higher levels during both the 2-week and 6-week autophagy inhibition. These findings suggest that autophagy insufficiency cumulatively leads to β-cell failure after a certain interval, accompanied by stepwise alterations of gene expression patterns.

Retrospective Study on the Effects of Glucose Abnormality on COVID-19 Outcomes in Japan

INTRODUCTION

To investigate the effects of glucose abnormality on outcomes of hospitalized coronavirus disease 2019 (COVID-19) patients in Japan.

METHODS

This study retrospectively analyzed 393 COVID-19 patients admitted at Juntendo University Hospital. Patients were divided into subgroups according to history of diabetes and blood glucose (BG) levels and subsequently compared in terms of in-hospital death, invasive ventilation, or a composite of both.

RESULTS

Patients with glucose abnormality demonstrated more risk factors for serious COVID-19, such as high body mass index, dyslipidemia, and hypertension, and higher biomarkers for inflammation compared to those with normal BG levels. Oxygen inhalation and steroid use were more frequent among patients with than without glucose abnormality. Invasive ventilation was more frequent in patients with diabetes (9.5% vs. 3.2%, p = 0.033) and BG ≥ 140 mg/dl (11.0% vs. 3.1%, p = 0.009) compared with those without diabetes and BG < 140 mg/dl, respectively. Logistic regression analysis showed that BG ≥ 140 mg/dl was a risk factor for invasive ventilation [odds ratio (OR) 2.87, 95% CI 1.04-7.68, p = 0.037] or the composite outcome (OR 3.03, 95% CI 1.21-7.38, p = 0.015) even after adjusting for by age and gender. Kaplan-Meier analysis showed that glucose abnormality was significantly associated with invasive ventilation and that BG ≥ 140 mg/dl was a risk factor for invasive ventilation [hazard ratio (HR) 2.68, 95% CI 1.05-6.82, p = 0.039] and the composite of death and invasive ventilation (HR 2.77, 95% CI 1.21-6.37, p = 0.016) regardless of age and gender.

CONCLUSIONS

Glucose abnormality, particularly BG ≥ 140 mg/dl, was associated with serious outcomes among Japanese COVID-19 patients, suggesting the need to consider high BG as a major risk factor for poor clinical course also in Japan.

Defective autophagy in vascular smooth muscle cells enhances the healing of abdominal aortic aneurysm

Autophagy is an evolutionarily conserved cellular catabolic process essential for cell homeostasis, and thus its failure is associated with several diseases. While autophagy has been reported to play a role in vascular smooth muscle cells (SMCs) in vascular disorders, its precise role in the pathogenesis of abdominal aortic aneurysm (AAA) has not yet been elucidated. In this study, we investigated the role of SMC autophagy in AAA formation. As a mouse model of AAA, we used control apolipoprotein E-deficient (apoeKO) mice and Atg7cKO (SMC-specific Atg7-deficient mice):apoeKO mice administered angiotensin II for 4 weeks. Intriguingly, Kaplan-Meier curves showed that the survival rates of Atg7cKO:apoeKO mice were significantly higher than those of apoeKO mice. The hematoma area in AAA of Atg7cKO:apoeKO mice was smaller than in apoeKO mice despite the lack of a significant difference in AAA incidence between the two groups. Furthermore, the amount of granulomatous tissues was significantly larger and the collagen-positive area within AAA was significantly larger in Atg7cKO:apoeKO mice than in apoeKO mice. In accordance with these findings, SMCs cultured from Atg7cKO mice showed increased expression of collagens, independent of angiotensin II action. Taken together, our data suggest that defective autophagy in SMCs elicits AAA healing that may underlie the better survival rate under dyslipidemia and angiotensin II infusion.

AMPK regulates cell shape of cardiomyocytes by modulating turnover of microtubules through CLIP-170

AMP-activated protein kinase (AMPK) is a multifunctional kinase that regulates microtubule (MT) dynamic instability through CLIP-170 phosphorylation; however, its physiological relevance in vivo remains to be elucidated. In this study, we identified an active form of AMPK localized at the intercalated disks in the heart, a specific cell-cell junction present between cardiomyocytes. A contractile inhibitor, MYK-461, prevented the localization of AMPK at the intercalated disks, and the effect was reversed by the removal of MYK-461, suggesting that the localization of AMPK is regulated by mechanical stress. Time-lapse imaging analysis revealed that the inhibition of CLIP-170 Ser-311 phosphorylation by AMPK leads to the accumulation of MTs at the intercalated disks. Interestingly, MYK-461 increased the individual cell area of cardiomyocytes in CLIP-170 phosphorylation-dependent manner. Moreover, heart-specific CLIP-170 S311A transgenic mice demonstrated elongation of cardiomyocytes along with accumulated MTs, leading to progressive decline in cardiac contraction. In conclusion, these findings suggest that AMPK regulates the cell shape and aspect ratio of cardiomyocytes by modulating the turnover of MTs through homeostatic phosphorylation of CLIP-170 at the intercalated disks.

Rubicon in pancreatic beta cells plays a limited role in maintaining glucose homeostasis following increased insulin resistance

Autophagy has been reported to play a crucial role in the maintenance of intracellular homeostasis, including in pancreatic beta cells. Rubicon, which interacts with the phosphoinositide 3-kinase (PI3K) complex, through autophagy-related 14 (ATG14), is among the few autophagy regulators that have been reported to inhibit autophagic flux to date and the deletion of Rubicon has been shown to increase autophagic flux. Based on previous results showing a causal relationship between autophagic dysfunction and pancreatic beta-cell impairment, we hypothesized that the deletion of Rubicon in pancreatic beta cells would improve cell integrity and confer protective effects. To test this hypothesis, we first confirmed that Rubicon knockdown (KD) promoted autophagic flux in βTC3 pancreatic beta-cell line. Next, we generated pancreatic beta-cell-specific Rubicon knockout (βKO) mice, by administering tamoxifen to Rubicon^flox/flox:MIP-Cre-ERT mice, which showed normal glucose tolerance and insulin secretion under a normal chow diet, despite successful gene recombination. We also attempted to increase insulin resistance by feeding the mice with a high-fat diet for an additional 2 months to find little differences among the parameters evaluated for glucose metabolism. Finally, severe insulin resistance was induced with insulin receptor antagonist treatment, which resulted in comparable glucose homeostasis measurements between Rubicon βKO and control mice. In summary, these results suggest that in pancreatic beta cells, Rubicon plays a limited role in the maintenance of systemic glucose homeostasis.

Increased risk of cardiovascular mortality by strict glycemic control (pre-procedural HbA1c < 6.5%) in Japanese medically-treated diabetic patients following percutaneous coronary intervention: a 10-year follow-up study

BACKGROUND

In the secondary prevention of cardiovascular (CV) disease in patients with diabetes, an optimal level of HbA1c, the most widely-used glycemic control indicator, for favorable clinical consequences still remains to be established. This study assessed the association between preprocedural HbA1c level and CV mortality in Japanese diabetic patients undergoing percutaneous coronary intervention (PCI).

METHODS

This is a retrospective observational study using a single-center prospective PCI database involving consecutive 4542 patients who underwent PCI between 2000 and 2016. Patients with any antidiabetic medication including insulin at PCI were included in the analysis (n = 1328). We divided the patients into 5 and 2 groups according to HbA1c level; HbA1c: < 6.5% (n = 267), 6.5-7.0% (n = 268), 7.0-7.5% (n = 262), 7.5-8.5% (n = 287) and ≥ 8.5% (n = 244), and 7.0% > and ≤ 7.0%, respectively. The primary outcome was CV mortality including sudden death. The median follow-up duration was 6.2 years.

RESULTS

In the follow-up period, CV and sudden death occurred in 81 and 23 patients, respectively. While unadjusted Kaplan-Meier analysis showed no difference in cumulative CV mortality rate between patients binarized by preprocedural HbA1c 7.0%, analysis of the 5 groups of HbA1c showed significantly higher cumulative CV death in patients with HbA1c < 6.5% compared with those with 7.0-7.5% (P = 0.042). Multivariate Cox hazard analysis revealed a U-shaped relationship between preprocedural HbA1c level and risk of CV death, and the lowest risk was in the HbA1c 7.0-7.5% group (Hazard ratio of HbA1c < 6.5% compared to 7.0-7.5%: 2.97, 95% confidence interval: 1.33-7.25, P = 0.007). Similarly, univariate analysis revealed the lowest risk of sudden death was in the HbA1c 7.0-7.5% group.

CONCLUSION

The findings indicate an increased risk of CV mortality by strict glycemic control (HbA1c < 6.5%) in the secondary prevention of CV disease in Japanese patients with medically-treated diabetes. Trial registration This study reports the retrospective analysis of a prospective registry database of patients who underwent PCI at Juntendo University Hospital, Tokyo, Japan (Juntendo Physicians' Alliance for Clinical Trials, J-PACT), which is publicly registered (University Medical Information Network Japan-Clinical Trials Registry UMIN-CTR 000035587).

Mutant KCNJ3 and KCNJ5 Potassium Channels as Novel Molecular Targets in Bradyarrhythmias and Atrial Fibrillation

BACKGROUND

Bradyarrhythmia is a common clinical manifestation. Although the majority of cases are acquired, genetic analysis of families with bradyarrhythmia has identified a growing number of causative gene mutations. Because the only ultimate treatment for symptomatic bradyarrhythmia has been invasive surgical implantation of a pacemaker, the discovery of novel therapeutic molecular targets is necessary to improve prognosis and quality of life.

METHODS

We investigated a family containing 7 individuals with autosomal dominant bradyarrhythmias of sinus node dysfunction, atrial fibrillation with slow ventricular response, and atrioventricular block. To identify the causative mutation, we conducted the family-based whole exome sequencing and genome-wide linkage analysis. We characterized the mutation-related mechanisms based on the pathophysiology in vitro. After generating a transgenic animal model to confirm the human phenotypes of bradyarrhythmia, we also evaluated the efficacy of a newly identified molecular-targeted compound to upregulate heart rate in bradyarrhythmias by using the animal model.

RESULTS

We identified one heterozygous mutation, KCNJ3 c.247A>C, p.N83H, as a novel cause of hereditary bradyarrhythmias in this family. KCNJ3 encodes the inwardly rectifying potassium channel Kir3.1, which combines with Kir3.4 (encoded by KCNJ5) to form the acetylcholine-activated potassium channel ( I_KACh channel) with specific expression in the atrium. An additional study using a genome cohort of 2185 patients with sporadic atrial fibrillation revealed another 5 rare mutations in KCNJ3 and KCNJ5, suggesting the relevance of both genes to these arrhythmias. Cellular electrophysiological studies revealed that the KCNJ3 p.N83H mutation caused a gain of I_KACh channel function by increasing the basal current, even in the absence of m₂ muscarinic receptor stimulation. We generated transgenic zebrafish expressing mutant human KCNJ3 in the atrium specifically. It is interesting to note that the selective I_KACh channel blocker NIP-151 repressed the increased current and improved bradyarrhythmia phenotypes in the mutant zebrafish.

CONCLUSIONS

The I_KACh channel is associated with the pathophysiology of bradyarrhythmia and atrial fibrillation, and the mutant I_KACh channel ( KCNJ3 p.N83H) can be effectively inhibited by NIP-151, a selective I_KACh channel blocker. Thus, the I_KACh channel might be considered to be a suitable pharmacological target for patients who have bradyarrhythmia with a gain-of-function mutation in the I_KACh channel.

Higd1a improves respiratory function in the models of mitochondrial disorder

The respiratory chain (RC) transports electrons to form a proton motive force that is required for ATP synthesis in the mitochondria. RC disorders cause mitochondrial diseases that have few effective treatments; therefore, novel therapeutic strategies are critically needed. We previously identified Higd1a as a positive regulator of cytochrome c oxidase (CcO) in the RC. Here, we test that Higd1a has a beneficial effect by increasing CcO activity in the models of mitochondrial dysfunction. We first demonstrated the tissue-protective effects of Higd1a via in situ measurement of mitochondrial ATP concentrations ([ATP]_mito) in a zebrafish hypoxia model. Heart-specific Higd1a overexpression mitigated the decline in [ATP]_mito under hypoxia and preserved cardiac function in zebrafish. Based on the in vivo results, we examined the effects of exogenous HIGD1A on three cellular models of mitochondrial disease; notably, HIGD1A improved respiratory function that was coupled with increased ATP synthesis and demonstrated cellular protection in all three models. Finally, enzyme kinetic analysis revealed that Higd1a significantly increased the maximal velocity of the reaction between CcO and cytochrome c without changing the affinity between them, indicating that Higd1a is a positive modulator of CcO. These results corroborate that Higd1a, or its mimic, provides therapeutic options for the treatment of mitochondrial diseases.

Age-related and seasonal change in serum osmolarity and water intake in a healthy population

Background and aim

Few studies have clarified the seasonal and age-related change of serum osmolarity and water intake, which is thought to be associated with heat stroke and ischemic stroke. We investigated the association between them in a healthy population.

Methods

We conducted a cross-sectional study using database from Kobe Orthopedic and Biomedical Epidemiologic (KOBE) Study. Among 1138 healthy Japanese participants in the baseline survey, 1010 (women 704 and men 306) participants were eligible for the present study. Daily non-alcohol drink (NAD) intake was estimated according to food frequency questionnaire. Alcohol beverage and water in the meal or soup were excluded from the counting. Serum osmolarity (Osm/L) was calculated by Worthley’s formula: 2 (serum sodium (mEq/L)) + (blood urea nitrogen (mg/dL))/2.8 + (glucose (mg/dL))/18. The seasons the surveys were conducted were categorized into 4 groups, March-May (Spring), June-August (Summer), September-November (Autumn), and December-February (Winter). The association between serum osmolarity and daily NAD intake was analyzed using linear regression models.

Results

The seasonal change was observed in the serum osmolarity and daily NAD intake; serum osmolarity increased in spring and summer and daily NAD intake increased in summer. The serum osmolarity increased by aging in any seasons, while daily water intake didn’t. There was no significant association observed between serum osmolarity and the daily NAD intake, even after adjusting for sex, age, and season.

Conclusions

Serum osmolarity showed seasonal and age-related changes, but the serum osmolarity in subjects who had the daily habit of high NAD intake was not necessarily low.

Key messages

Serum osmolarity increased by aging and in spring and summer. Serum osmolarity was not associated with non-alcohol drink intake.

Conversion of pancreatic α cells into insulin-producing cells modulated by β-cell insufficiency and supplemental insulin administration

The emergence of bihormonal (BH) cells expressing insulin and glucagon has been reported under diabetic conditions in humans and mice. Whereas lineage tracing studies demonstrated that glucagon-producing α cells can be reprogrammed into BH cells, the underlying dynamics of the conversion process remain poorly understood. In the present study, we investigated the identities of pancreatic endocrine cells by genetic lineage tracing under diabetic conditions. When β-cell ablation was induced by alloxan (ALX), a time-dependent increase in BH cells was subsequently observed. Lineage tracing experiments demonstrated that BH cells originate from α cells, but not from β cells, in ALX-induced diabetic mice. Notably, supplemental insulin administration into diabetic mice resulted in a significant increase in α-cell-derived insulin-producing cells that did not express glucagon. Furthermore, lineage tracing in Ins2^Akita diabetic mice demonstrated a significant induction of α-to-β conversion. Thus, adult α cells have plasticity, which enables them to be reprogrammed into insulin-producing cells under diabetic conditions, and this can be modulated by supplemental insulin administration.

Establishment of a system for screening autophagic flux regulators using a modified fluorescent reporter and CRISPR/Cas9

Autophagy is a mechanism of bulk protein degradation that plays an important role in regulating homeostasis in many organisms. Among several methods for evaluating its activity, a fluorescent reporter GFP-LC3-RFP-LC3ΔG, in which GFP-LC3 is cleaved by ATG4 following autophagic induction and degraded in lysosome, has been used for monitoring autophagic flux, which is the amount of lysosomal protein degradation. In this study, we modified this reporter by exchanging GFP for pHluorin, which is more sensitive to low pH, and RFP to mCherry, to construct pHluorin-LC3-mCherry reporter. Following starvation or mTOR inhibition, the increase of autophagic flux was detected by a decrease of the fluorescent ratio of pHluorin to mCherry; our reporter was also more sensitive to autophagy-inducing stimuli than the previous one. To establish monitoring cells for mouse genome-wide screening of regulators of autophagic flux based on CRISPR/Cas9 system, after evaluating knockout efficiency of clones of Cas9-expressing MEFs, we co-expressed our reporter and confirmed that autophagic flux was impaired in gRNA-mediated knockout of canonical autophagy genes. Finally, we performed genome-wide gRNA screening for genes inhibiting starvation-mediated autophagic flux and identified previously reported genes such as Atgs. Thus, we have successfully established a system for screening of genes regulating autophagic flux with our pHluorin-LC3-mCherry reporter in mice.

Cellular Autophagy in α Cells Plays a Role in the Maintenance of Islet Architecture

Autophagy is known to play a pivotal role in intracellular quality control through the degradation of subcellular damaged organelles and components. Whereas autophagy is essential for maintaining β-cell function in pancreatic islets, it remains unclear as to how the cellular autophagy affects the homeostasis and function of glucagon-secreting α cells. To investigate the role of autophagy in α cells, we generated a mutant mouse model lacking Atg7, a key molecule for autophagosome formation, specifically in α cells. Histological analysis demonstrated more glucagon-positive cells, with a multilayered structure, in the islets under Atg7 deficiency, although metabolic profiles, such as body weight, blood glucose, and plasma glucagon levels were comparable between Atg7-deficient mice and control littermates. Consistent with our previous findings that Atg7 deficiency suppressed β-cell proliferation, cellular proliferation was suppressed in Atg7-deficient α cells. These findings suggest that α-cell autophagy plays a role in maintaining α-cell area and normal islet architecture but appears to be dispensable for metabolic homeostasis.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.

A molecular triage process mediated by RING finger protein 126 and BCL2-associated athanogene 6 regulates degradation of G0/G1 switch gene 2

Oxidative phosphorylation generates most of the ATP in respiring cells. ATP is an essential energy source, especially in cardiomyocytes because of their continuous contraction and relaxation. Previously, we reported that G₀/G₁ switch gene 2 (G0S2) positively regulates mitochondrial ATP production by interacting with F_OF₁-ATP synthase. G0S2 overexpression mitigates ATP decline in cardiomyocytes and strongly increases their hypoxic tolerance during ischemia. Here, we show that G0S2 protein undergoes proteasomal degradation via a cytosolic molecular triage system and that inhibiting this process increases mitochondrial ATP production in hypoxia. First, we performed screening with a library of siRNAs targeting ubiquitin-related genes and identified RING finger protein 126 (RNF126) as an E3 ligase involved in G0S2 degradation. RNF126-deficient cells exhibited prolonged G0S2 protein turnover and reduced G0S2 ubiquitination. BCL2-associated athanogene 6 (BAG6), involved in the molecular triage of nascent membrane proteins, enhanced RNF126-mediated G0S2 ubiquitination both in vitro and in vivo Next, we found that Glu-44 in the hydrophobic region of G0S2 acts as a degron necessary for G0S2 polyubiquitination and proteasomal degradation. Because this degron was required for an interaction of G0S2 with BAG6, an alanine-replaced G0S2 mutant (E44A) escaped degradation. In primary cultured cardiomyocytes, both overexpression of the G0S2 E44A mutant and RNF126 knockdown effectively attenuated ATP decline under hypoxic conditions. We conclude that the RNF126/BAG6 complex contributes to G0S2 degradation and that interventions to prevent G0S2 degradation may offer a therapeutic strategy for managing ischemic diseases.

Establishment of a novel platform cell line for efficient and precise evaluation of T cell receptor functional avidity

Adoptive T-cell therapy with T cell receptor (TCR) -engineered T cells is an attractive strategy for cancer treatment and the success in this therapy is dependent on the functional avidity of the transduced TCRs against targeted tumor antigens. Therefore, the establishment of the methodology of the efficient and precise evaluation of TCR functional avidity has been awaited. Here, we show a novel platform cell line, named 2D3, which enables the functional avidity of transduced TCRs to be evaluated efficiently and precisely. In the 2D3, the precise TCR functional avidity of transduced TCRs is easily evaluable by the expression of green fluorescent protein (GFP) reporter gene driven by nuclear factor of activated T cells (NFAT) activation via TCR signaling. Four different TCRs of HLA-A^*24:02-restricted Wilms’ tumor gene 1 (WT1)-specific CD8⁺ cytotoxic T lymphocytes (CTLs) were transduced into 2D3 cells and the functional avidities of these four TCRs were evaluated. The evaluated functional avidity of these TCRs positively correlated with cell proliferation, cytokine production, and WT1-specific cytotoxicity of the TCR-transduced CD8⁺ T cells in response to WT1 antigen. These results showed that 2D3 cell line was a novel and stable tool useful for the efficient and precise evaluation of the functional avidity of isolated and transduced TCRs in developing TCR-based immunotherapy.

Suppression of STAT3 signaling promotes cellular reprogramming into insulin-producing cells induced by defined transcription factors

BACKGROUND

STAT3 has been demonstrated to play a role in maintaining cellular identities in the pancreas, whereas an activating STAT3 mutation has been linked to impaired β-cell function.

METHODS

The role of STAT3 in β-cell neogenesis, induced by the exogenous expression of Pdx1, Neurog3, and Mafa, was analyzed in vitro and in vivo.

FINDINGS

The expression of phosphorylated STAT3 (pSTAT3) was induced in both Pdx1-expressing and Mafa-expressing cells, but most of the induced β cells were negative for pSTAT3. The suppression of STAT3 signaling, together with exogenously expressed Pdx1, Neurog3, and Mafa, significantly increased the number of reprogrammed β cells in vitro and in vivo, enhanced the formation of islet-like clusters in mice, and ameliorated hyperglycemia in diabetic mice.

INTERPRETATION

These findings suggest that STAT3 inhibition promotes cellular reprogramming into β-like cells, orchestrated by defined transcription factors, which may lead to the establishment of cell therapies for curing diabetes. FUND: JSPS, MEXT, Takeda Science Foundation, Suzuken Memorial Foundation, Astellas Foundation for Research on Metabolic Disorders, Novo Nordisk, Eli Lilly, MSD, Life Scan, Novartis, and Takeda.

Defective autophagy in vascular smooth muscle cells enhances cell death and atherosclerosis

Macroautophagy/autophagy is considered as an evolutionarily conserved cellular catabolic process. In this study, we aimed to elucidate the role of autophagy in vascular smooth muscle cells (SMCs) on atherosclerosis. SMCs cultured from mice with SMC-specific deletion of the essential autophagy gene atg7 (Atg7cKO) showed reduced serum-induced cell growth, increased cell death, and decreased cell proliferation rate. Furthermore, 7-ketocholestrerol enhanced apoptosis and the expression of CCL2 (chemokine [C-C motif] ligand 2) with the activation of TRP53, the mouse ortholog of human and rat TP53, in SMCs from Atg7cKO mice. In addition, Atg7cKO mice crossed with Apoe (apolipoprotein E)-deficient mice (apoeKO; Atg7cKO:apoeKO) showed reduced medial cellularity and increased TUNEL-positive cells in the descending aorta at 10 weeks of age. Intriguingly, Atg7cKO: apoeKO mice fed a Western diet containing 1.25% cholesterol for 14 weeks showed a reduced survival rate. Autopsy of the mice demonstrated the presence of aortic rupture. Analysis of the descending aorta in Atg7cKO:apoeKO mice showed increased plaque area, increased TUNEL-positive area, decreased SMC-positive area, accumulation of macrophages in the media, and adventitia and perivascular tissue, increased CCL2 expression in SMCs in the vascular wall, medial disruption, and aneurysm formation. In conclusion, our data suggest that defective autophagy in SMCs enhances atherosclerotic changes with outward arterial remodeling.

Periventricular small cystic lesions in a patient with Coffin-Lowry syndrome who exhibited a novel mutation in the RPS6KA3 gene

BACKGROUND

Coffin-Lowry syndrome is a rare X-linked disease, caused by loss-of-function mutations in the RPS6KA3 gene. Patients exhibit severe intellectual disability with characteristic dysmorphism. As there are no specific laboratory findings to support the diagnosis of Coffin-Lowry syndrome, it may be difficult to diagnose-especially in young children, where the characteristic craniofacial features are less discernible.

CASE

Here we report on a 2-year-old boy with Coffin-Lowry syndrome with a novel missense mutation in the RPS6KA3 gene. On magnetic resonance imaging, his brain exhibited periventricular signal abnormalities with multiple small cystic lesions. These findings may aid in diagnosis of Coffin-Lowry syndrome.

Everolimus Directly Suppresses Insulin Secretion Independently of Cell Growth Inhibition

Everolimus, an orally administered mammalian target of rapamycin inhibitor, has been widely used as an immunosuppressant and an anticancer agent. Whereas everolimus can control recurrent hypoglycemia in patients with insulinoma, possibly through tumor regression and/or the direct inhibition of insulin secretion, time-dependent changes in serum insulin levels caused by everolimus still remain unclear. Here we report a clinical case of a patient with metastatic insulinoma, in which frequent monitoring of serum insulin levels demonstrated rapid and substantial changes in insulin secretion levels, a few days after the discontinuation as well as the readministration of everolimus. To further confirm the direct effect of everolimus on β-cell function, we performed in vitro experiments using mouse insulinoma cells (MIN6) and human induced pluripotent stem cell (hiPSC)–derived insulin-producing cells and found that everolimus significantly suppressed glucose-stimulated insulin secretion in both MIN6 cells and hiPSC–derived insulin-producing cells. Thus, both a patient with metastatic insulinoma and in vitro experiments demonstrated that everolimus directly suppresses insulin secretion, independently of its tumor regression effect.

Vision System for an Autonomous Underwater Vehicle with a Benthos Sampling Function

We developed a vision system for an autonomous underwater robot with a benthos sampling function, specifically sampling-autonomous underwater vehicle (AUV). The sampling-AUV includes the following five modes: preparation mode (PM), observation mode (OM), return mode (RM), tracking mode (TM), and sampling mode (SM). To accomplish the mission objective, the proposed vision system comprises software modules for image acquisition, image enhancement, object detection, image selection, and object tracking. The camera in the proposed system acquires images in intervals of five seconds during OM and RM, and in intervals of one second during TM. The system completes all processing stages in the time required for image acquisition by employing high-speed algorithms. We verified the effective operation of the proposed system in a pool.

Underwater Platform for Intelligent Robotics and its Application in Two Visual Tracking Systems

A hovering-type autonomous underwater vehicle (AUV) capable of cruising at low altitudes and observing the seafloor using only mounted sensors and payloads was developed for sea-creature survey. The AUV has a local area network (LAN) interface for an additional payload that can acquire navigation data from the AUV and transmit the target value to the AUV. In the handling process of the state flow of an AUV, additional payloads can control the AUV position using the transmitted target value without checking the AUV condition. In the handling process of the state flow of an AUV, additional payloads can control the AUV position using the transmitted target value without checking the AUV condition. In this research, water tank tests and sea trials were performed using an AUV equipped with a visual tracking system developed in other laboratories. The experimental results proved that additional payload can control the AUV position with a standard deviation of 0.1 m.

Dram1 regulates DNA damage-induced alternative autophagy

Autophagy is an evolutionarily conserved process that degrades subcellular constituents. Mammalian cells undergo two types of autophagy; Atg5-dependent conventional autophagy and Atg5-independent alternative autophagy, and the molecules required for the latter type of autophagy are largely unknown. In this study, we analyzed the molecular mechanisms of genotoxic stress-induced alternative autophagy, and identified the essential role of p53 and damage-regulated autophagy modulator (Dram1). Dram1 was sufficient to induce alternative autophagy. In the mechanism of alternative autophagy, Dram1 functions in the closure of isolation membranes downstream of p53. These findings indicate that Dram1 plays a pivotal role in genotoxic stress-induced alternative autophagy.

Abstract P6-11-17: Nanoparticle albumin-bound paclitaxel-induced peripheral neuropathy in patients receiving neoadjuvant or adjuvant chemotherapy for breast cancer

A brief background discussion.

Nanoparticle albumin-bound paclitaxel (nab-PTX) has been developed under the concept of improved drug delivery. nab-PTX has been shown to significantly increase progression-free survival compared with solvent-based paclitaxel (PTX) in metastatic breast cancer. However, the long-term outcomes of nab-PTX induced peripheral neuropathy (nPIPN) have not yet been fully elucidated.

Trial design: observational cohort study (UMIN20852)

Primary objective: The long-term outcome of nPIPN

Secondary objectives

(1)The validity of the Neuropathic Pain Screening Questionnaire (Japan–Q, Ishikawa et al. Pain Research 2016 )

(2) To evaluate the effect of frozen gloves and elastic stockings for nPIPN

nPIPN was assessed by the Japan-Q (J-Q) and Common Toxicity Criteria for Adverse Events ver 4.0 (CTC). The J-Q is an assessment tool for patient-reported pain severity, which consists of seven items, each rated on a five-point scale 0-4; grade 0 (no symptoms) to grade 4 (verysevere symptoms). Pricking pain, electric shock pain, burn like pain, tingling pain with numbness, allodynia, reduced or hyper sensitivity and hand-foot syndrome. Assessment was performed every day during chemotherapy, six months and one year after completion of nab-PTX therapy. Total of 28 points for each day and 588 points for each cycle, higher point correlates with severity. Frozen gloves during administration of nab-PTX and/or elastic stockings were optionally used.

Statistical methods

Kruskal Wallis test was used and p&lt;0.05 was considered as significant.

RESULTS:

Between May 2013, and April 2016, 105 patients were enrolled from 7 hospitals. In 73 patients (69.5%) nab-PTX was administered as primary and in 32 patients (30.5%) as adjuvant therapy. Forty three (41.0%) patients received nab-PTX as first line and 62 (59.0%) received after anthracycline contained regimen. Trastuzumab was administered as combination therapy with nab-PTX for Her2 positive patients. Both frozen gloves and stockings were used in 21 patients (20.0%) and frozen gloves only were used in 21 patients (20.0%) according to patient preference.

One hundred patients (95.2%) completed four courses, and overall relative dose intensity was 91.4%.

During chemotherapy, J-Q scores go elevated from day 1 to day 5 and gradually declined throughout the rest of the cycle. Without using frozen gloves, there was a significant increase according to courses (1st: 45.0 ± 5.7, 2nd: 76.7 ± 8.6, 3rd: 94.3 ± 11.8, 4th: 95.4 ± 11.8). Using frozen gloves, there was a significant increase from 1st course to 2nd, but no further increase was observed(1st: 37.4 ± 8.1, 2nd: 61.9 ± 12.4, 3rd: 62.9 ± 10.4, 4th: 55.3 ± 10.6). After six month and one year, the scores were significantly lower compared with the last day of the fourth cycle (4.28 ± 0.50, 2.53 ± 0.25, 2.85 ± 0.39, respectively). CTC, grade 2 or more sensory disturbance was observed in 57.9% after four cycles, but improved to 9.5% and 5.4% after six month and one year respectively.

CONCLUSIONS:

Patient-reported nPIPN was significantly getting worse without frozen gloves during chemotherapy, however be largely reversible within 1 year of PST or adjuvant treatment. The J-Q findings support that nab-PTX treatment is tolerable.

Citation Format: Yoshidome K, Morimoto T, Matsunami N, Tsunashima R, Tsukamoto F, Ryo T, Nishida Y, Shimo T, Anno K, Shimada M, Udo M, Kagawa M, Morishima H, Oda N. Nanoparticle albumin-bound paclitaxel-induced peripheral neuropathy in patients receiving neoadjuvant or adjuvant chemotherapy for breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-11-17.