Publications by authors named "Hironori Waki"

The physiological actions of a gut hormone, glucagon-like peptide-1 (GLP-1), in Alzheimer's disease (AD) brain remain poorly understood, although GLP-1 receptor (GLP-1R) expression in this organ has been shown in several experimental studies. Therefore, we explored whether the GLP-1R signaling promotes the clearance of amyloid β (Aβ) (1-42) which is a core pathological hallmark of AD, focusing on the water channel protein aquaporin 4 (AQP4) localized to astrocyte endfeet perivascular membranes in intact brain. First, we confirmed that Glp1r mRNA is predominantly expressed at perivascular site of astrocytes in normal mouse cerebral cortex through in situ hybridization analysis.

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Article Synopsis
  • White adipose tissue (WAT) plays a crucial role in storing lipids and maintaining energy balance, making adipocyte formation and stability important for addressing obesity and metabolic disorders.
  • Researchers identified PATZ1 as a significant adipogenic transcription factor involved in the development of adipocytes, as it promotes adipogenesis through specific protein interactions and DNA binding.
  • Experiments revealed that removing PATZ1 in mice resulted in decreased adipocyte precursor cells and fat mass, highlighting its essential regulatory role in adipocyte differentiation and overall fat tissue development.
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Background: Increasing physical activity improves glycemic control in patients with type 2 diabetes (T2D). Mobile health (mHealth) interventions have been proven to increase exercise, but engagement often fades with time. As the use of health behavior theory in mHealth design can increase effectiveness, we developed StepAdd, an mHealth intervention based on the constructs of social cognitive theory (SCT).

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Article Synopsis
  • A 67-year-old man with type 1 diabetes and other health issues was hospitalized after experiencing right hemiplegia and speech difficulties due to low blood sugar levels.
  • After administering glucose, his symptoms resolved, but he had similar episodes three times within 10 days, typically occurring at night.
  • A review of cases showed that recurrent hypoglycemic hemiplegia is more common on the right side and often happens at night; proper glucose management is crucial to prevent these episodes.
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Background: Intramuscular adipose tissue (IMAT) formation derived from muscle fibro-adipogenic progenitors (FAPs) has been recognized as a pathological feature of sarcopenia. This study aimed to explore whether genetic and pharmacological gastric inhibitory polypeptide (GIP) receptor antagonism suppresses IMAT accumulation and ameliorates sarcopenia in mice.

Methods: Whole body composition, grip strength, skeletal muscle weight, tibialis anterior (TA) muscle fibre cross-sectional area (CSA) and TA muscle IMAT area were measured in young and aged male C57BL/6 strain GIP receptor (Gipr)-knockout (Gipr ) and wild-type (Gipr ) mice.

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Adipose tissue is central to regulation of energy homeostasis. Adaptive thermogenesis, which relies on mitochondrial oxidative phosphorylation (Ox-Phos), dissipates energy to counteract obesity. On the other hand, chronic inflammation in adipose tissue is linked to type 2 diabetes and obesity.

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Background: We previously conducted a pilot randomized controlled trial "the MASTER study" and demonstrated that alpha-glucosidase inhibitor miglitol and a dipeptidyl peptidase-4 inhibitor sitagliptin modified postprandial plasma excursions of active glucagon-like peptide-1 (aGLP-1) and active gastric inhibitory polypeptide (aGIP), and miglitol treatment decreased body fat mass in patients with type 2 diabetes (T2D). However, the details regarding the relationships among postprandial plasma aGLP-1 and aGIP excursions, skeletal muscle mass, and body fat mass are unclear.

Methods: We conducted a secondary analysis of the relationships among skeletal muscle mass index (SMI), total body fat mass index (TBFMI), and the incremental area under the curves (iAUC) of plasma aGLP-1 and aGIP excursions following mixed meal ingestion at baseline and after 24-week add-on treatment with either miglitol alone, sitagliptin alone, or their combination in T2D patients.

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Although the measurement of hemoglobin A1c (HbA1c) using high-performance liquid chromatography (HPLC) is routinely used to estimate average blood glucose levels, it may not be accurately measured for various reasons, such as alteration of red blood cell lifespan and the existence of hemoglobin variants; including hemoglobin F (HbF). Here, we report cases of fulminant type 1 and type 2 diabetes mellitus in which HbA1c levels were unmeasurable because of increased labile HbA1c levels. Case 1 involved a 73-year-old man with fulminant type 1 diabetes mellitus, who was brought to our hospital with diabetic ketoacidosis.

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Article Synopsis
  • - Vascular injury triggers a transformation in perivascular adipose tissue (PVAT) into a brown adipose tissue-like state, known as beiging, which helps regulate inflammation and vascular remodeling.
  • - In mouse studies, the accumulation of macrophages in PVAT leads to this beiging process, with genetic inhibition of beiging resulting in worse inflammation and vascular changes, while promoting beiging reduces these negative effects.
  • - Researchers found that the beiging of PVAT, particularly the secretion of neuregulin 4 (Nrg4) from these cells, plays a crucial role in activating macrophages to resolve inflammation, suggesting potential new treatments for atherosclerosis based on manipulating PVAT functions.
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Thermogenic brown and beige adipocytes counteract obesity by enhancing energy dissipation via uncoupling protein-1 (Ucp1). However, the effect of genetic variation on these cells, a major source of disease susceptibility, has been less well studied. Here we examined beige adipocytes from obesity-prone C57BL/6J (B6) and obesity-resistant 129X1/SvJ (129) mouse strains and identified a -regulatory variant rs47238345 that is responsible for differential Ucp1 expression.

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Introduction: A newly developed resistant starch (RS) rice line with double mutation of starch synthase IIIa and branching enzyme IIb (ss3a/be2b) exhibits a tenfold greater percentage RS value than the wild-type rice line. Currently, the effects of cooked rice with such high RS content on secretion and action of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are unclear. Therefore, we conducted a pilot study to assess postprandial responses of GLP-1 and GIP along with glucose and insulin and also gastric emptying after ingestion of the high-RS cooked rice with ss3a/be2b in healthy subjects.

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Isthmin-1 is an adipokine that has a potent glucose-lowering effect by stimulating a common intracellular signaling pathway with insulin through a distinct receptor and has an inhibitory effect on lipogenesis in the liver, whereas insulin has the opposite effect. Isthmin-1 is expected to have clinical benefits in the treatment of diabetes.

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Chronic intestinal pseudo-obstruction (CIPO) is a rare disorder of intestinal dysmotility characterized by chronic symptoms, including vomiting and abdominal pain, associated with bowel obstruction without any mechanical obstructive causes. We herein report a case of mitochondrial diseases with recurrent duodenal obstruction that was initially diagnosed as superior mesenteric artery syndrome (SMAS) for a few years but was later diagnosed as CIPO. Since CIPO is known to be associated with mitochondrial diseases, it should be considered in the differential diagnosis of patients with mitochondrial diseases presenting with recurrent intestinal obstruction.

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The transcription factor nuclear factor I-A (NFIA) is a regulator of brown adipocyte differentiation. Here we show that the C-terminal 17 amino acid residues of NFIA (which we call pro#3 domain) are required for the transcriptional activity of NFIA. Full-length NFIA-but not deletion mutant lacking pro#3 domain-rescued impaired expression of PPARγ, the master transcriptional regulator of adipogenesis and impaired adipocyte differentiation in NFIA-knockout cells.

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Aims: Monogenic diabetes is clinically heterogeneous and differs from common forms of diabetes (type 1 and 2). We aimed to investigate the clinical usefulness of a comprehensive genetic testing system, comprised of targeted next-generation sequencing (NGS) with phenotype-driven bioinformatics analysis in patients with monogenic diabetes, which uses patient genotypic and phenotypic data to prioritize potentially causal variants.

Methods: We performed targeted NGS of 383 genes associated with monogenic diabetes or common forms of diabetes in 13 Japanese patients with suspected (n = 10) or previously diagnosed (n = 3) monogenic diabetes or severe insulin resistance.

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Glucagon is detected in plasma even after total pancreatectomy, and it is debated whether this glucagon is derived from the gastrointestinal tract. Here, we applied sandwich enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-high-resolution mass spectrometry to measure plasma glucagon levels in one patient after partial pancreatectomy (one-seventh of the pancreas remaining) and three patients after total pancreatectomy. Sandwich ELISA detected higher glucagon levels in pancreatectomy patients than in healthy individuals.

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To ensure that experiences and lessons learned from the unprecedented 2011 Great East Japan Earthquake are used to improve future disaster planning, the Japan Diabetes Society (JDS) launched the "Research and Survey Committee for Establishing Disaster Diabetes Care Systems Based on Relevant Findings from the Great East Japan Earthquake" under the supervision of the Chairman of the JDS. The Committee conducted a questionnaire survey among patients with diabetes, physicians, disaster medical assistance teams (DMATs), nurses, pharmacists, and nutritionists in disaster areas about the events they saw happening, the situations they found difficult to handle, and the needs that they felt required to be met during the 2011 Great East Japan Earthquake. A total of 3,481 completed questionnaires were received.

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Background: Disease modeling with patient-derived induced pluripotent stem cells (iPSCs) is a powerful tool for elucidating the mechanisms underlying disease pathogenesis and developing safe and effective treatments. Patient peripheral blood (PB) cells are used for iPSC generation in many cases since they can be collected with minimum invasiveness. To derive iPSCs that lack immunoreceptor gene rearrangements, hematopoietic stem and progenitor cells (HSPCs) are often targeted as the reprogramming source.

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To ensure that experiences and lessons learned from the unprecedented 2011 Great East Japan Earthquake are used to improve future disaster planning, the Japan Diabetes Society (JDS) launched the "Research and Survey Committee for Establishing Disaster Diabetes Care Systems Based on Relevant Findings from the Great East Japan Earthquake" under the supervision of the Chairman of the JDS. The Committee conducted a questionnaire survey among patients with diabetes, physicians, disaster medical assistance teams (DMATs), nurses, pharmacists, and nutritionists in disaster areas about the events they saw happening, the situations they found difficult to handle, and the needs that they felt required to be met during the 2011 Great East Japan Earthquake. A total of 3,481 completed questionnaires were received.

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Adipocyte differentiation is regulated by various mechanisms, of which mitotic clonal expansion (MCE) is a key step. Although this process is known to be regulated by cell cycle modulators, the precise mechanism remains unclear. -Methyladenosine (mA) posttranscriptional RNA modification, whose methylation and demethylation are performed by respective enzyme molecules, has recently been suggested to be involved in the regulation of adipogenesis.

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Brown fat dissipates energy as heat and protects against obesity. Here, we identified nuclear factor I-A (NFIA) as a transcriptional regulator of brown fat by a genome-wide open chromatin analysis of murine brown and white fat followed by motif analysis of brown-fat-specific open chromatin regions. NFIA and the master transcriptional regulator of adipogenesis, PPARγ, co-localize at the brown-fat-specific enhancers.

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CDK5 Regulatory Subunit-Associated Protein 1-like 1 (CDKAL1) was identified as a susceptibility gene for type 2 diabetes and body mass index in genome-wide association studies. Although it was reported that CDKAL1 is a methylthiotransferase essential for tRNA(UUU) and faithful translation of proinsulin generated in pancreatic β cells, the role of CDKAL1 in adipocytes has not been understood well. In this study, we found that CDKAL1 is expressed in adipose tissue and its expression is increased during differentiation.

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Obesity is a risk factor for many diseases including diabetes, cancer, cardiovascular disease, and chronic kidney disease. Obesity is characterized by the expansion of white adipose tissue (WAT). Hypertrophy and hyperplasia of adipocytes cause tissue hypoxia followed by inflammation and fibrosis.

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Objectives: To examine the prevalence of the willingness of patients with diabetes to use a self-management tool based on information and communication technology (ICT) such as personal computers, smartphones, and mobile phones; and to examine the patient characteristics associated with that willingness.

Research Design And Methods: We conducted a cross-sectional interview survey of 312 adults with diabetes at a university hospital in an urban area in Japan. Participants were classified into 2 groups: those who were willing to use an ICT-based self-management tool and those who were unwilling.

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