Language：English   Publishing type：Research paper (scientific journal)  

CONTEXT: Diabetic retinopathy (DR) is a common microvascular complication of diabetes, and identifying the risk factors for severe DR is important. OBJECTIVE: We aimed to investigate the relationship between severe DR and the extracellular water to total body water ratio (ET ratio). DESIGN: Retrospective cross-sectional study. SETTING: Department of Endocrinology, Metabolism, and Diabetes at Kyushu University Hospital. PATIENTS: A total of 205 adults with type 2 diabetes (T2D) were included. The patients were divided into two groups: non-proliferative DR (non-PDR; n = 161, 126 with no DR and 35 with simple DR) and proliferative DR (PDR; n = 44, 18 with pre-proliferative DR and 26 with PDR). MAIN OUTCOME MEASURE: The ET ratio was measured using bioelectrical impedance analysis. RESULTS: The ET ratio was significantly higher in the PDR group than in the non-PDR group (0.390 vs. 0.398; P < .0001). Multivariate logistic regression analysis showed that the ET ratio was significantly associated with PDR, independent of known risk factors for DR progression. In the subgroup analysis by age, multivariate logistic regression analysis revealed a significant association between the ET ratio and PDR, independent of known risk factors for DR progression in patients younger than 60 years. However, in patients 60 years and older, only the urinary albumin to creatinine ratio (UACR) showed a significant association with PDR in a model using the UACR and the ET ratio. CONCLUSION: In patients with T2D younger than 60 years, the ET ratio may be a useful indicator for identifying severe DR.

DOI： 10.1210/clinem/dgae768

Web of Science

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PLoS ONE  

The Cre-loxP strategy for tissue-specific gene inactivation has become a widely employed tool in several research studies. Conversely, inadequate breeding and genotyping without considering the potential for non-specific Cre-recombinase expression may lead to misinterpretations of results. Nestin-Cre transgenic mice, widely used for the selective deletion of genes in neurons, have been observed to have an incidence of Cre-line germline recombination. In this study, we attempted to generate neuron-specific Glucagon-like peptide 1 receptor (Glp1r) knock-out mice by crossing mice harboring the Nestin-Cre transgene with mice harboring the Glp1r gene modified with loxP insertion, in order to elucidate the role of Glp1r signaling in the nervous system. Surprisingly, during this breeding process, we discovered that the null allele emerged in the offspring irrespective of the presence or absence of the Nestin-Cre transgene, with a high probability of occurrence (93.6%). To elucidate the cause of this null allele, we conducted breeding experiments between mice carrying the heterozygous Glp1r null allele but lacking the Nestin-Cre transgene. We confirmed that the null allele was inherited by the offspring independently of the Nestin-Cre transgene. Furthermore, we assessed the gene expression, protein expression, and phenotype of mice carrying the homozygous Glp1r null allele generated from the aforementioned breeding, thereby confirming that the null allele indeed caused a global knock-out of Glp1r. These findings suggest that the null allele in the NestinCre-Glp1r floxed breeding arose due to germline recombination. Moreover, we demonstrated the possibility that germline recombination may occur not only during the spermatogenesis at testis but also during epididymal sperm maturation. The striking frequency of germline recombination in the Nestin-Cre driver underscores the necessity for caution when implementing precise breeding strategies and employing suitable genotyping methods.

DOI： 10.1371/journal.pone.0296006

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Pancreatic islet inflammation plays a crucial role in the etiology of type 2 diabetes (T2D). Macrophages residing in pancreatic islets have emerged as key players in islet inflammation. Macrophages express a plethora of innate immune receptors that bind to environmental and metabolic cues and integrate these signals to trigger an inflammatory response that contributes to the development of islet inflammation. One such receptor, Dectin-2, has been identified within pancreatic islets; however, its role in glucose metabolism remains largely unknown. Here we demonstrated that mice lacking Dectin-2 exhibit local inflammation within islets, along with impaired insulin secretion and β-cell dysfunction. Our findings indicate that these effects are mediated by pro-inflammatory cytokines, such as IL-1α and IL-6, which are secreted by macrophages that have acquired an inflammatory phenotype because of the loss of Dectin-2. This study provides novel insights into the mechanisms underlying the role of Dectin-2 in the development of islet inflammation.

DOI： 10.1210/endocr/bqad181

Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Diabetes is associated with an increased risk of deleterious changes in muscle mass and function or sarcopenia, leading to physical inactivity and worsening glycaemic control. Given the negative energy balance during sodium-glucose cotransporter-2 (SGLT2) inhibition, whether SGLT2 inhibitors affect skeletal muscle mass and function is a matter of concern. However, how SGLT2 inhibition affects the skeletal muscle function in patients with diabetes remains insufficiently explored. We aimed to explore the effects of canagliflozin (CANA), an SGLT2 inhibitor, on skeletal muscles in genetically diabetic db/db mice focusing on the differential responses of oxidative and glycolytic muscles. METHODS: Db/db mice were treated with CANA for 4 weeks. We measured running distance and handgrip strength to assess skeletal muscle function during CANA treatment. At the end of the experiment, we performed a targeted metabolome analysis of the skeletal muscles. RESULTS: CANA treatment improved the reduced endurance capacity, as revealed by running distance in db/db mice (414.9 ± 52.8 vs. 88.7 ± 22.7 m, P < 0.05). Targeted metabolome analysis revealed that 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl 5'-monophosphate (AICARP), a naturally occurring AMP-activated protein kinase (AMPK) activator, increased in the oxidative soleus muscle (P < 0.05), but not in the glycolytic extensor digitorum longus muscle (P = 0.4376), with increased levels of AMPK phosphorylation (P < 0.01). CONCLUSIONS: This study highlights the potential role of the AICARP/AMPK pathway in oxidative rather than glycolytic skeletal muscles during SGLT2 inhibition, providing novel insights into the mechanism by which SGLT2 inhibitors improve endurance capacity in patients with type 2 diabetes.

DOI： 10.1002/jcsm.13350

Language：Japanese   Publishing type：Research paper (scientific journal)  

Sulfonylureas (SUs) are effective and affordable antidiabetic drugs. However, chronic use leads to secondary failure, limiting their utilization. Here, we identify cytochrome b5 reductase 3 (Cyb5r3) down-regulation as a mechanism of secondary SU failure and successfully reverse it. Chronic exposure to SU lowered Cyb5r3 abundance and reduced islet glucose utilization in mice in vivo and in ex vivo murine islets. Cyb5r3 β cell-specific knockout mice phenocopied SU failure. Cyb5r3 engaged in a glucose-dependent interaction that stabilizes glucokinase (Gck) to maintain glucose utilization. Hence, Gck activators can circumvent Cyb5r3-dependent SU failure. A Cyb5r3 activator rescued secondary SU failure in mice in vivo and restored insulin secretion in ex vivo human islets. We conclude that Cyb5r3 is a key factor in the secondary failure to SU and a potential target for its prevention, which might rehabilitate SU use in diabetes.

DOI： 10.1126/scitranslmed.abq4126

Language：Japanese  

Country：Japan  

Language：Japanese  

Country：Japan  

Language：Japanese  

Country：Japan  

Language：Japanese  

Country：Japan  

Language：Japanese  

Country：Japan  

Language：English  

Understanding the genetic factors of diabetes is essential for addressing the global increase in type 2 diabetes. HNF1A mutations cause a monogenic form of diabetes called maturity-onset diabetes of the young (MODY), and HNF1A single-nucleotide polymorphisms are associated with the development of type 2 diabetes. Numerous studies have been conducted, mainly using genetically modified mice, to explore the molecular basis for the development of diabetes caused by HNF1A mutations, and to reveal the roles of HNF1A in multiple organs, including insulin secretion from pancreatic beta cells, lipid metabolism and protein synthesis in the liver, and urinary glucose reabsorption in the kidneys. Recent studies using human stem cells that mimic MODY have provided new insights into beta cell dysfunction. In this article, we discuss the involvement of HNF1A in beta cell dysfunction by reviewing previous studies using genetically modified mice and recent findings in human stem cell-derived beta cells.

DOI： 10.3390/ijms23063222