👤 Yushi Otsuka

Remote ischemic preconditioning (RIpreC) is a strategy for remotely protecting target organs such as the brain by applying brief ischemia and reperfusion to the limb. However, the mechanisms underlying RIpreC-induced neuroprotection remain unclear. We aimed to investigate the neuroprotective effects of RIpreC on the peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α)/ fibronectin type III domain-containing protein 5 (FNDC5)/ brain-derived neurotrophic factor (BDNF) pathway in rat models of ischemic stroke. Rats were assigned to three groups: ischemia-reperfusion injury (IR, The online version contains supplementary material available at 10.1007/s12975-026-01422-z. Show less

Theogallin, a tea-derived polyphenol enriched in newly developed cultivars such as MK5601, has been shown to have cognitive benefits. However, its biological and mechanistic effects of theogallin remain unclear. Herein, we investigated the transcriptomic profiles of six mouse tissues after oral theogallin administration. Theogallin induced tissue-enriched transcriptional responses, particularly in the brain, where it activated memory-related and neuronal activity-related pathways through the upregulation of immediate-early genes (IEGs). These transcriptional changes closely resembled brain-derived neurotrophic factor (BDNF)-induced neuronal activation and contrasted with gene expression patterns associated with Alzheimer's disease. In aged mice, theogallin improved recognition memory and increased the expression of IEGs-associated proteins, while reducing neurodegeneration-linked markers. Theogallin also enhanced neuronal gene expression in SH-SY5Y cells, supporting a direct neuromodulatory role and further promoting neurite outgrowth. Therefore, theogallin is a functional enhancer of neuronal activation with potential therapeutic relevance for age-related cognitive decline and neurodegenerative disorders. Show less

The apolipoprotein E ε4 (APOE ε4) allele, a major genetic risk factor for Alzheimer's disease, is associated with early atrophy in the precuneus and posterior cingulate cortex. Whether physical activity can mitigate this atrophy in high-risk APOE ε4 carriers remains unclear. This study aimed to determine whether physical activity can reduce such neurodegenerative changes in older adults carrying this allele. This 10-year longitudinal study included 295 community-dwelling older adults (154 men and 141 women; age ≥65 years). Baseline physical activity was measured using accelerometers and analyzed according to activity intensity. Participants were categorized as APOE ε4 carriers or non-carriers. Volumes of the precuneus and posterior cingulate cortex were assessed using longitudinal magnetic resonance imaging. Sex-stratified linear mixed models examined the interaction between physical activity and APOE ε4 status on brain volume changes, adjusting for relevant covariates. The moderate-to-vigorous physical activity (MVPA) × APOE ε4 × year effect in women's left precuneus was significant unadjusted but not after false discovery rate (FDR; 16 models) and exploratory. Left precuneus volume declined significantly over 10 years regardless of MVPA level or APOE ε4 genotype (each p < 0.0001). However, among APOE ε4 carriers, greater time spent in MVPA slowed the rate of volume decline. No similar effect was observed in men. Higher habitual MVPA may be associated with slower left precuneus decline in APOE ε4-positive women. As this exploratory three‑way effect was FDR‑nonsignificant, targeted replication is needed to clarify the role of everyday activity in genetically vulnerable groups. Show less

Apolipoprotein E (ApoE) plays an important role in cerebral lipid transport. Beyond lipid transport, ApoE also contributes to the maintenance of neuronal integrity. Although DNA damage and dysfunction in the DNA damage response are recognized as early contributors to neuropathology, the connection between ApoE and DNA damage remains poorly understood. In this study, we investigated cells expressing endogenous mouse ApoE (mApoE) in the brain under both normal condition and etoposide-induced DNA damage. Immunohistochemical analysis revealed that mApoE was predominantly expressed in astrocytes and a subset of neurons across various brain regions, with minimal expression in microglia and no detectable expression in oligodendrocytes. Induction of DNA damage through etoposide treatment did not alter the expression level or distribution pattern of mApoE in brain. However, a correlation between neuronal mApoE expression and DNA damage was observed: mApoE-positive neurons were more affected and exhibited a higher number of γH2A.X foci upon etoposide treatment. This observation warrants further investigation to determine whether the increased sensitivity of mApoE-positive neurons to DNA damage is neuroprotective or contributes to neurodegeneration. Our study provides a foundation for understanding the physiological role of mApoE in response to DNA damage and suggests a potential involvement of neuronal mApoE in neurodegeneration. Show less

Agricultural or gardening activity (also known as hobby farming) is a simple strategy that may be effective for maintaining health and preventing lifestyle-related diseases. However, its preventive effect on the development of conditions associated with neurovascular aging (e.g., stroke and dementia) remains unclear. To comprehensively investigate the preventive role of regular agricultural or gardening physical activity (AGPA) in neurovascular aging and its underlying mechanisms using two approaches. We conducted an experimental study in which we assessed arterial stiffness, cognitive performance (Flanker and Stroop tests), and circulating biomarkers (e.g., plasmin-α2-plasmin inhibitor complexes, nitric oxide, brain-derived neurotrophic factor) in 12 male students (average age: 22 ± 1 years) before and after three 40-min interventions (resting, cycling, and simulated AGPA) under controlled conditions. We also conducted a cross-sectional study, in which we recruited 161 (79 in the AGPA group and 82 in the control group) hospital-based older individuals (average age: 78 ± 5 years) and assessed their history of stroke, cognitive function, and brain magnetic resonance imaging (MRI) findings. In the experimental study, simulated AGPA reduced arterial stiffness, improved executive cognitive function, and elevated circulating plasmin-α2-plasmin inhibitor complexes, nitric oxide, and brain-derived neurotrophic factor. Brain MRI-assessed cerebral white matter hyperintensities caused by reduced blood flow to brain tissue and stroke prevalence were lower, and cognitive scores (as assessed by the Hasegawa Dementia Scale-Revised) were higher in the AGPA group than in the control group. Our findings suggest that regular AGPA is associated with markers of slower neurovascular aging in older individuals. AGPA induces a combination of general physical activity-related and specific AGPA-related effects; moreover, it may offer similar or even greater benefits than physical activity alone. Therefore, habitual AGPA may serve as an effective preventive strategy for neurovascular aging. Show less

Type 2 diabetic patients exhibited an increased secretion of triglyceride-rich lipoproteins and low high-density lipoprotein cholesterol levels with a greater amount of small dense low-density lipoprotein (LDL). Given that apolipoprotein B (apoB), a proatherogenic lipoprotein, exists at both triglyceride-rich lipoproteins and LDL particles, circulating apoB may associate with diabetic coronary atherosclerosis. The OPTIMAL study was a prospective randomized-controlled study which employed serial near-infrared spectroscopy (NIRS)/intravascular ultrasound (IVUS) imaging to evaluate the efficacy of glycemic control on coronary atherosclerosis in 94 statin-treated type 2 diabetic patients with coronary artery disease (CAD) (UMIN000036721). Of these, 78 patients with both serial apoB levels and NIRS/IVUS images at baseline and week 48 were analyzed. NIRS/IVUS-derived plaque measures were compared in those with and without any reduction of apoB levels. All of the study subjects received a statin, and 60.6% of the study subjects exhibited any reduction of apoB levels. There was no significant difference in the atheroma progression rate between the 2 groups (-0.27 ± 0.15% vs -0.33 ± 0.51%, P = .44). However, patients with any reduction of apoB levels exhibited a greater frequency of change in maximal lipid-core burden index at 4-mm segment (maxLCBI In statin-treated type 2 diabetic patients with CAD, a greater delipidation of coronary atherosclerosis was observed in association with a reduction of apoB levels. The current findings indicate a potential anti-atherosclerotic effect of lowering apoB levels, which may ultimately mitigate future coronary events risk in statin-treated type 2 diabetic patients with CAD. Show less

Hepatocellular carcinoma (HCC) arises from various etiologies, including viral hepatitis and non-viral liver diseases. Although comprehensive genomic profiling (CGP) is increasingly applied in oncology, the influence of disease etiology on the genomic landscape of HCC and biomarker applicability remains insufficiently characterized. CGP data from 551 patients with HCC, registered in the National Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database, were analyzed after excluding cases with undefined etiology. We characterized the mutational landscape, compared mutation frequencies among HBV-, HCV-, and non-viral, non-cholestatic (nBnC)-related HCC, assessed the association between homologous recombination repair (HRR)-related gene alterations and tumor mutation burden (TMB), and evaluated the detection rates of actionable mutations in tissue- versus liquid-based CGP. Telomerase reverse transcriptase splice site mutations were the most common genomic alteration and were consistently observed across all etiologic groups. Although mutations in AXIN1 and DDR2 genes showed modest enrichment in HCV- and HBV-related HCC, respectively, the overall mutational profiles remained largely conserved across etiologies. TMB was significantly lower in nBnC-HCC compared to HCV-related HCC but showed no association with HRR-related mutations. The detection rates of targetable mutations were similar between tissue and liquid biopsies; however, only a small proportion of patients received matched therapies. Real-world data indicate a conserved genomic architecture in HCC regardless of etiology, supporting unified therapeutic approaches. The absence of a relationship between HRR alterations and TMB suggests distinct biological mechanisms. Liquid biopsy remains a reliable option when tissues are unavailable in managing patients with HCC. Show less

Photochemical reactions are powerful tools for synthesizing organic molecules. The input of energy provided by light offers a means to produce strained and unique molecules that cannot be assembled using thermal protocols, allowing for the production of immense molecular complexity in a single chemical step. Furthermore, unlike thermal reactions, photochemical reactions do not require active reagents such as acids, bases, metals, or enzymes. Photochemical reactions play a central role in green chemistry. This article reports the isolation and structure determination of four new compounds (1-4) from the photoreaction products of the Polyozellus multiplex MeOH ext. The structures of the new compounds were elucidated using MS, IR, comprehensive NMR measurements and microED. The four compounds were formed by deacetylation of polyozellin, the main secondary metabolite of P. multiplex, and addition of singlet oxygen generated by sunlight. To develop drugs for treating Alzheimer's disease (AD) on the basis of the amyloid cascade hypothesis, the compounds (1-4) obtained by photoreaction were evaluated for BACE1 inhibitory activity. The hydrolysates (5 and 6) of polyozellin, the main secondary metabolites of P. multiplex, were also evaluated. The photoreaction products (3 and 4) and hydrolysates (5 and 6) of polyozellin showed BACE1 inhibitory activity (IC Show less

Recent studies have advanced our understanding of the pathophysiology of autoimmune gastritis, particularly its molecular aspects. The most noteworthy recent advancement lies in the identification of several candidate genes implicated in the pathogenesis of pernicious anemia through genome-wide association studies. These genes include Show less

Some patients with inflammatory bowel disease (IBD) who were under mesalamine treatment develop adverse reactions called "mesalamine allergy," which includes high fever and worsening diarrhea. Currently, there is no method to predict mesalamine allergy. Pharmacogenomic approaches may help identify these patients. Here we analyzed the genetic background of mesalamine intolerance in the first genome-wide association study of Japanese patients with IBD. Two independent pharmacogenetic IBD cohorts were analyzed: the MENDEL (n = 1523; as a discovery set) and the Tohoku (n = 788; as a replication set) cohorts. Genome-wide association studies were performed in each population, followed by a meta-analysis. In addition, we constructed a polygenic risk score model and combined genetic and clinical factors to model mesalamine intolerance. In the combined cohort, mesalamine-induced fever and/or diarrhea was significantly more frequent in ulcerative colitis vs Crohn's disease. The genome-wide association studies and meta-analysis identified one significant association between rs144384547 (upstream of RGS17) and mesalamine-induced fever and diarrhea (P = 7.21e-09; odds ratio = 11.2). The estimated heritability of mesalamine allergy was 25.4%, suggesting a significant correlation with the genetic background. Furthermore, a polygenic risk score model was built to predict mesalamine allergy (P = 2.95e-2). The combined genetic/clinical prediction model yielded a higher area under the curve than did the polygenic risk score or clinical model alone (area under the curve, 0.89; sensitivity, 71.4%; specificity, 90.8%). Mesalamine allergy was more common in ulcerative colitis than in Crohn's disease. We identified a novel genetic association with and developed a combined clinical/genetic model for this adverse event. Show less

Heparan sulfate (HS), a highly sulfated linear polysaccharide, is involved in diverse biological functions in various tissues. Although previous studies have suggested a possible contribution of HS to the differentiation of white adipocytes, there has been no direct evidence supporting this. Here, we inhibited the synthesis of HS chains in 3T3-L1 cells using CRISPR-Cas9 technology, resulting in impaired differentiation of adipocytes with attenuated bone morphogenetic protein 4 (BMP4)-fibroblast growth factor 1 (FGF1) signaling pathways. HS reduction resulted in reduced glucose uptake and decreased insulin-dependent intracellular signaling. We then made heterozygous mutant mice for the Ext1 gene, which encodes an enzyme essential for the HS biosynthesis, specifically in the visceral white adipose tissue (Fabp4-Cre Show less

The aim of the present study was to consider whether the ultrastructural features of cardiomyocytes in dilated cardiomyopathy can be used to guide genetic testing. Endomyocardial biopsy and whole-exome sequencing were performed in 32 consecutive sporadic dilated cardiomyopathy patients [51.0 (40.0-64.0) years, 75% men] in initial phases of decompensated heart failure. The predicted pathogenicity of ultrarare (minor allele frequency ≤0.0005), non-synonymous variants was determined using the American College of Medical Genetics guidelines. Focusing on 75 cardiomyopathy-susceptibility and 41 arrhythmia-susceptibility genes, we identified 404 gene variants, of which 15 were considered pathogenic or likely pathogenic in 14 patients (44% of 32). There were five sarcomeric gene variants (29% of 17 variants) found in five patients (16% of 32), involving a variant of MYBPC3 and four variants of TTN. A patient with an MYBPC3 variant showed disorganized sarcomeres, three patients with TTN variants located in the region encoding the A-band domain showed sparse sarcomeres, and a patient with a TTN variant in encoding the I-band domain showed disrupted sarcomeres. The distribution of diffuse myofilament lysis depended on the causal genes; three patients with the same TMEM43 variant had diffuse myofilament lysis near nuclei (P = 0.011), while two patients with different DSP variants had lysis in the peripheral areas of cardiomyocytes (P = 0.033). Derangement patterns of myofilament and subcellular distribution of myofilament lysis might implicate causal genes. Large-scale studies are required to confirm whether these ultrastructural findings are related to the causative genes. Show less

Hypertrophic cardiomyopathy (HCM), which is inherited as an autosomal dominant trait, is the most prevalent hereditary cardiac disease. Although there are several reports on the systematic screening of mutations in the disease-causing genes in European and American populations, only limited information is available for Asian populations, including Japanese. Genetic screening of disease-associated mutations in 8 genes for sarcomeric proteins, MYH7, MYBPC3, MYL2, MYL3, TNNT2, TNNI3, TPM1, and ACTC, was performed by direct sequencing in 112 unrelated Japanese proband patients with familial HCM; 37 different mutations, including 13 novel ones in 5 genes, MYH7, MYBPC3, TNNT2, TNNI3, and TPM1, were identified in 49 (43.8%) patients. Among them, 3 carried compound heterozygous mutations in MYBPC3 or TNNT2. The frequency of patients carrying the MYBPC3, MYH7, and TNNT2 mutations were 19.6%, 10.7%, and 8.9%, respectively, and the most frequently affected genes in the northeastern and southwestern parts of Japan were MYBPC3 and MYH7, respectively. Several mutations were found in multiple unrelated proband patients, for which the geographic distribution suggested founder effects of the mutations. This study demonstrated the frequency and distribution of mutations in a large cohort of familial HCM in Japan. Show less

The purpose of this study was to examine selective macrophage differentiation occurring in areas of intraplaque hemorrhage in human atherosclerosis. Macrophage subsets are recognized in atherosclerosis, but the stimulus for and importance of differentiation programs remain unknown. We used freshly isolated human monocytes, a rabbit model, and human atherosclerotic plaques to analyze macrophage differentiation in response to hemorrhage. Macrophages characterized by high expression of both mannose and CD163 receptors preferentially exist in atherosclerotic lesions at sites of intraplaque hemorrhage. These hemoglobin (Hb)-stimulated macrophages, M(Hb), are devoid of neutral lipids typical of foam cells. In vivo modeling of hemorrhage in the rabbit model demonstrated that sponges exposed to red cells showed an increase in mannose receptor-positive macrophages only when these cells contained Hb. Cultured human monocytes exposed to Hb:haptoglobin complexes, but not interleukin-4, expressed the M(Hb) phenotype and were characterized by their resistance to cholesterol loading and up-regulation of ATP-binding cassette (ABC) transporters. M(Hb) demonstrated increased ferroportin expression, reduced intracellular iron, and reactive oxygen species (ROS). Degradation of ferroportin using hepcidin increased ROS and inhibited ABCA1 expression and cholesterol efflux to apolipoprotein A-I, suggesting reduced ROS triggers these effects. Knockdown of liver X receptor alpha (LXRα) inhibited ABC transporter expression in M(Hb) and macrophages differentiated in the antioxidant superoxide dismutase. Last, LXRα luciferase reporter activity was increased in M(Hb) and significantly reduced by overnight treatment with hepcidin. Collectively, these data suggest that reduced ROS triggers LXRα activation and macrophage reverse cholesterol transport. Hb is a stimulus for macrophage differentiation in human atherosclerotic plaques. A decrease in macrophage intracellular iron plays an important role in this nonfoam cell phenotype by reducing ROS, which drives transcription of ABC transporters through activation of LXRα. Reduction of macrophage intracellular iron may be a promising avenue to increase macrophage reverse cholesterol transport. Show less

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder with an autosomal-dominant pattern of inheritance mainly caused by single heterozygous mutations in sarcomere genes. Although multiple gene mutations have recently been reported in Western countries, clinical implications of multiple mutations in Japanese subjects are not clear. A comprehensive genetic analysis of 5 sarcomere genes (cardiac β-myosin heavy chain gene [MYH7], cardiac myosin-binding protein C gene [MYBPC3], cardiac troponin T gene [TNNT2], α-tropomyosin gene [TPM1] and cardiac troponin I gene [TNNI3]) was performed in 93 unrelated patients and 14 mutations were identified in 28 patients. Twenty-six patients had single heterozygosity (20 in MYBPC3, 4 in MYH7, 1 in TNNT2, 1 in TNNI3), whereas 2 proband patients with familial HCM had double heterozygosity: 1 with P106fs in MYBPC3 and R869C in MYH7 and 1 with R945fs in MYBPC3 and E1049D in MYH7. From the results of the family survey and the previous literature on HCM mutations, P106fs, R945fs and R869C seemed to be pathological mutations and E1049D might be a rare polymorphism. The proband patient with P106fs and R869C double mutation was diagnosed as having HCM at an earlier age (28 years of age) than her relatives with single mutation, and had greater wall thickness with left ventricular outflow obstruction. One double mutation was identified in a Japanese cohort of HCM patients. Further studies are needed to clarify the clinical significance of multiple mutations including phenotypic severity. Show less

Carbamoylphosphate synthetase I deficiency (CPS1D) is a urea-cycle disorder characterized by episodes of life-threatening hyperammonemia. Correct diagnosis is crucial for patient management, but is difficult to make from clinical presentation and conventional laboratory tests alone. Enzymatic or genetic diagnoses have also been hampered by difficult access to the appropriate organ and the large size of the gene (38 exons). In this study, in order to address this diagnostic dilemma, we performed the largest mutational and clinical analyses of this disorder to date in Japan. Mutations in CPS1 were identified in 16 of 18 patients with a clinical diagnosis of CPS1D. In total, 25 different mutations were identified, of which 19 were novel. Interestingly, in contrast to previous reports suggesting an extremely diverse mutational spectrum, 31.8% of the mutations identified in Japanese were common to more than one family. We also identified two common polymorphisms that might be useful for simple linkage analysis in prenatal diagnosis. The accumulated clinical data will also help to reveal the clinical presentation of this rare disorder in Japan. Show less