👤 Toshio Taniguchi

Visceral fat (VF), particularly epicardial adipose tissue (EAT), plays a crucial role in the development of coronary artery disease (CAD). Cathelicidin (LL37) is an antimicrobial peptide involved in innate immunity and has been implicated in inflammatory processes. However, the relationship between VF accumulation, cathelicidin, and atherosclerosis remains unclear. Seventy-eight subjects without CAD were enrolled and classified by obesity type: normal-weight (normal; n=20), subcutaneous fat (SF; n=19), and VF (n=39). Plasma LL37 concentrations were compared across groups. LL37 expression in EAT was assessed in 9 patients undergoing open-heart surgery, stratified by CAD status. In animal experiments, angiotensin II-infused wild-type and Apoe LL37 is associated with VF accumulation and CAD. However, these findings are exploratory and warrant prospective validation to determine its potential utility as a biomarker. Show less

Glycosyltransferases that biosynthesize glycans and their genes (glycogenes) play important roles in health and disease. In general, pathophysiological changes are defined by comparing knock-out (KO) or knock-in mice generated using CRISPR-Cas9 and other technologies to normal mice. Next, target molecules such as glycoproteins, glycolipids, and proteoglycans to which various biosynthetic glycans bind were identified. As a result, we found that N-glycan branches biosynthesized by glycosyltransferases are intrinsically involved in Alzheimer's disease, cancer metastasis, epithelial mesenchymal transition (EMT)/mesenchymal epithelial transition (MET), type 2 diabetes, chronic obstructive pulmonary disease (COPD), and ulcerative colitis. For example, the addition of core fucose biosynthesized by α1,6-fucosyltransferase (Fut8) leads to dysregulation of TGF-β receptors. Bisecting N-acetylglucosamine (GlcNAc) biosynthesized by β-1,4-GlcNAc transferase III (GnT-III) affects the subcellular localization of Beta-site Amyloid Precursor Protein Cleaving Enzyme 1 (β-secretase 1, referred to as BACE1). β1,6GlcNAc branching biosynthesized by GnT-V leads to the modification of matrix metalloproteinase (MMP). Identification and characterization of N-glycan structures on these proteins were performed using a glycoproteomic approach based on lectin blotting, western blotting, liquid chromatography-electron spray ionization mass spectrometry, and histochemical staining. Recently, studies concerning redox regulation of N-glycans, termed Glyco-Redox, have emerged as a promising approach. Functional and pathophysiological glycan studies are one of the main goals of glycobiology research. In this review, we describe the role of N-glycan branching glycosyltransferases and their biosynthesized glycans in relation to various diseases, such as cancer metastasis, COPD, Alzheimer's disease, and ulcerative colitis. Show less

Advanced esophageal squamous cell carcinoma (ESCC) has a poor prognosis, and current treatments provide limited survival benefits. This study aimed to identify prognostic biomarkers and therapeutic targets by genomic profiling of advanced ESCC using circulating tumor DNA (ctDNA). The SCRUM-MONSTAR GOZILA study is a nationwide, plasma-based molecular profiling project using Guardant360, involving 31 core cancer institutions in Japan. We evaluated the genomic landscape of advanced ESCC and investigated associations between specific alterations and overall survival (OS). The correlation between blood tumor mutation burden (bTMB) and clinical outcomes in patients with PD-1 inhibitors was also assessed using multiple cutoff values (2, 4, 6, 8, and 10 mutations/Mb). Among 313 patients, alterations predominantly consisted of single nucleotide variants (SNVs, 68.9%) and copy number alterations (20.7%). ctDNA analysis identified key genomic alterations linked to poor outcomes in advanced ESCC, revealing potential prognostic biomarkers and therapeutic targets. In contrast, bTMB did not show predictive value for the efficacy of PD-1 inhibitors in this study. Show less

Although animal behavior is influenced by neuromodulatory signals, the underlying mechanism remains elusive. The ventral striatum, which consists of the olfactory tubercle (OT) and nucleus accumbens (NAc), promotes motivated behaviors and receives substantial neuromodulatory signals. We previously showed that the OT has anteromedial (am) and lateral domains regulating odor-guided attractive and aversive behaviors, respectively, in which the amOT highly expresses various receptors for feeding-regulated neuromodulators. Here, we investigated the functions of appetite-suppressing melanocortin 4 receptor (MC4R) signaling in the OT as well as in the NAc. When mice conditioned with an odor-food reward association underwent MC4R agonist injection in the amOT, their odor-attractive behavior was suppressed and odor-aversive behavior was induced. Conversely, injection of MC4R antagonist in the amOT induced attractive behavior to a neutral odor that was not associated with food reward. While MC4R agonist injection in the NAc shell did not influence odor-attractive behavior, it induced yawning and stretching behaviors. Consistent with a proposed role of these behaviors in the thermoregulation of the brain, recordings of brain temperature showed its occasional elevation after agonist injection, followed by the occurrence of yawning and stretching. These observations demonstrate the differential roles of MC4R signaling in the ventral striatum, the promotion of odor-aversive behavior in the amOT, and yawning/stretching behavior in the NAc, which are considered to collectively contribute to behavioral control under feeding. Show less

Verubecestat, atabecestat, and elenbecestat are small-molecule BACE1 inhibitors. Based on their structures, we designed and synthesized a novel BACE1 inhibitor with a hydroxyproline-derived N-amidinopyrrolidine scaffold. The initially synthesized derivative 7a showed a weak but detectable inhibitory activity against recombinant BACE1, which suggested that this novel scaffold was a viable BACE1 inhibitor. To enhance its activity, 22 derivatives with various substituents on the terminal benzene rings of the two biphenyl groups were synthesized and evaluated. Structure-activity relationship studies showed that introducing a substituent at the meta position of the biphenyl group on the hydroxy terminal improved the activity, and we identified the highly active derivative 12f. In contrast, substituents at the para position of the biphenyl group on the carboxy terminal increased activity. Additionally, we investigated the absolute configuration of the substituted pyrrolidine ring, which showed that the (2S,4R)-derivative exhibited the highest activity. Docking simulations suggested that a bulkier substituent tended to be located in the S1 and S3 pockets and that the binding mode significantly changed depending on which biphenyl group the substituent was attached to. These results show that the new scaffold would be useful for further development of small-molecule BACE1 inhibitors. Show less

In solid tumors, cancer cells adapt to hypoxic and nutrient deprived environments to support malignant progression. This study examined whether hypoxic and low glucose conditions enhance malignant behaviors more strongly in highly migratory MG63-R10 cells, which are derived from osteosarcoma MG-63 cells, compared to parental MG-63 cells, and further investigated whether lysophosphatidic acid (LPA) receptor signaling regulates this adaptation. MG63-R10 and MG-63 cells were cultured under hypoxic (1% O Under 1% O These results suggest that, compared to parental MG-63 cells, highly migratory osteosarcoma MG63-R10 cells adapt their malignant cellular functions to hypoxic and low-glucose conditions through LPA receptor signaling, highlighting this pathway as a potential therapeutic target in aggressive osteosarcomas. The online version contains supplementary material available at 10.1007/s12195-025-00873-y. Show less

The phase angle (PhA), assessed using bioelectrical impedance analysis (BIA), is becoming increasingly popular as an index of muscle quality associated with various health-related outcomes. This study aimed to clarify the relationship between PhA and sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA), which were objectively measured using accelerometers in older adults with disabilities requiring care. We recruited 90 older adults (39 men and 51 women, mean age of 78.7 ± 6.7 years) with disabilities under the long-term care insurance system. Skeletal muscle mass index (SMI) and PhA of the lower limbs were measured using a multifrequency BIA instrument. Daily durations of SB, LPA, and MVPA per day were measured using a triaxial accelerometer. Nutritional status was assessed using the long form of the Mini Nutritional Assessment (MNA). The MVPA duration was significantly associated with lower limb PhA after adjusting for age, sex, SB and LPA durations, MNA score, and medical history (p = 0.037), whereas SB and LPA durations were not associated with lower limb PhA. The duration of SB, LPA, and MVPA were not significantly associated with lower limb SMI, whereas the MNA score was. Lower limb PhA, but not lower limb SMI, was associated with MVPA duration, independent of nutritional status and medical history. Enhancing the duration of MVPA is needed to maintain the PhA and prevent further decline in physical function in older adults who require long-term care due to disabilities. Show less

Cataracts are opacifications of the lens that cause loss of visual acuity and ultimately of eyesight. Age-related cataract develops in most elderly people, but the mechanisms of cataract onset are incompletely understood. The Ihara Cataract Rat (ICR) is an animal model of hereditary cataracts showing cortical opacity that commonly develops prematurely. We identified putative mechanisms of cataract onset in the ICR rat model by measuring gene expression changes before and after cortical cataract development and conducting point mutation analysis. Genes differentially expressed between 4-week-old animals without cortical cataracts and 8-10-week-old animals with cortical cataracts were selected from microarray analysis. Three connections were identified by STRING analysis: (i) Epithelial-Mesenchymal Transition (EMT), including Col1a2, and Pik3r1. (ii) Lens homeostasis, including Aqp5, and Cpm. (iii) Lipid metabolism, including Scd1, Srebf1, and Pnpla3. Subsequently, mutation points were selected by comparing ICR rats with 12 different rats that do not develop cataracts. The apolipoprotein Apoc3 was mutated in ICR rats. Analyses of gene expression changes and point and mutations suggested that abnormalities in EMT or lipid metabolism could contribute to cataract development in ICR rats. Show less

Heparan sulfate (HS) is a glycocalyx component present in the extracellular matrix and cell-surface HS proteoglycans (HSPGs). Although HSPGs are known to play functional roles in multiple aspects of tumor development and progression, the effect of HS expression in the tumor stroma on tumor growth in vivo remains unclear. We conditionally deleted Ext1, which encodes a glycosyltransferase essential for the biosynthesis of HS chains, using S100a4-Cre (S100a4-Cre; Ext1f/f) to investigate the role of HS in cancer-associated fibroblasts, which is the main component of the tumor microenvironment. Subcutaneous transplantation experiments with murine MC38 colon cancer and Pan02 pancreatic cancer cells demonstrated substantially larger subcutaneous tumors in S100a4-Cre; Ext1f/f mice. Additionally, the number of myofibroblasts observed in MC38 and Pan02 subcutaneous tumors of S100a4-Cre; Ext1f/f mice decreased. Furthermore, the number of intratumoral macrophages decreased in MC38 subcutaneous tumors in S100a4-Cre; Ext1f/f mice. Finally, the expression of matrix metalloproteinase-7 (MMP-7) markedly increased in Pan02 subcutaneous tumors in S100a4-Cre; Ext1f/f mice, suggesting that it may contribute to rapid growth. Therefore, our study demonstrates that the tumor microenvironment with HS-reduced fibroblasts provides a favorable environment for tumor growth by affecting the function and properties of cancer-associated fibroblasts, macrophages, and cancer cells. Show less

We investigated the influence of multiple oral administration on the accumulation of dalcetrapib (JTT-705/RO4607381), a novel cholesteryl ester transfer protein inhibitor, in rats. It is well known that orally administered dalcetrapib is rapidly hydrolysed to its active form, which has a sulfhydryl group, in the body. The active form then binds covalently to endogenous thiols via mixed disulfide bonds. Following multiple once daily oral administration of Show less

Donor cell leukemia (DCL) occurs after allogeneic hematopoietic stem cell transplantation. Several mechanisms, including occult leukemic/preleukemic subclones in the donor graft and germline predisposition to leukemia, are proposed to be associated with DCL's molecular pathogenesis. We report a comprehensive genetic analysis of a patient with KMT2A-rearranged DCL after allogeneic bone marrow transplantation for refractory cytopenia of childhood. We performed a whole-exome sequencing of the recipient's peripheral blood before transplant and the donor's peripheral blood and the recipient's bone marrow at the time of DCL diagnosis. RNA sequencing was also performed to detect fusion genes in DCL blasts. There were no germline mutations that were associated with a predisposition to leukemia in the recipient and donor. Furthermore, there were no detectable somatic alterations except KMT2A-MLLT10 and other related gene fusions in DCL. KMT2A-MLLT10 was not detectable in the donor's bone marrow. We propose a novel pattern of the molecular pathogenesis of DCL solely involving a genetic mutation acquired after transplant with no identifiable genetic factor related to the donor and recipient. Show less

Genetic alterations in specific genes are critical events in carcinogenesis and hepatocellular carcinoma (HCC) progression. However, the genetic alterations responsible for HCC development, progression, and survival are unclear. We investigated the essential difference in genetic alterations between HCC and adjacent non-HCC tissues using next-generation sequencing technology. We found recurrent mutations in several genes such as telomerase reverse transcriptase (TERT; 65% of the total 104 HCCs), TP53 (38%), CTNNB1 (30%), AXIN1 (2%), PTEN (2%), and CDKN2A (2%). TERT promoter mutations were associated with older age (p = 0.005), presence of hepatitis C virus (HCV) infection (p = 0.003), and absence of hepatitis B virus (HBV) infection (p < 0.0001). In hepatitis B surface antigen (HBs Ag)-positive HCC without TERT promoter mutations, HBV integration into TERT locus was found in 47% patients and was mutually exclusive to TERT promoter mutations. Most (89%) HBV integrants were in the HBx region. TP53 mutations were associated with HBV infection (p = 0.0001) and absence of HCV infection (p = 0.002). CTNNB1 mutations were associated with absence of HBV infection (p = 0.010). Moreover, TERT promoter mutation was significantly associated with shorter disease-free survival (p = 0.005) and poor overall survival (p = 0.024). Gene alterations in TERT promoter, TP53, CTNNB1, and HBV integration were closely associated with HCC development, and mutations in TERT promoter are related to poor prognosis. These results are useful for understanding the underlying mechanism of hepatocarcinogenesis, diagnosis, and predicting outcomes of patients with HCC. Show less

Fatty acid composition is an economically important trait in meat-producing livestock. To gain insight into the molecular genetics of fatty acid desaturase (FADS) genes in pigs, we investigated the genomic structure of the porcine FADS gene family on chromosome 2. We also examined the tissue distribution of FADS gene expression. The genomic structure of FADS family in mammals consists of three isoforms FADS1, FADS2 and FADS3. However, porcine FADS cluster in the latest pig genome assembly (Sscrofa 10.2) containing some gaps is distinct from that in other mammals. We therefore sought to determine the genomic structure, including the FADS cluster in a 200-kbp range by sequencing gap regions. The structure we obtained was similar to that in other mammals. We then investigated the porcine FADS1 transcription start site and identified a novel isoform named FADS1b. Phylogenetic analysis revealed that the three members of the FADS cluster were orthologous among mammals, whereas the various FADS1 isoforms identified in pigs, mice and cattle might be attributable to species-specific transcriptional regulation with alternative promoters. Porcine FADS1b and FADS3 isoforms were predominantly expressed in the inner layer of the subcutaneous adipose tissue. Additional analyses will reveal the effects of these functionally unknown isoforms on fatty acid composition in pig fat tissues. Show less

Reverse cholesterol transport (RCT) removes excess cholesterol from macrophages to prevent atherosclerosis. ATP-binding cassette, subfamily A, member 1 (ABCA1) is a crucial cholesterol transporter involved in RCT to produce high density lipoprotein-cholesterol (HDLC), and is transcriptionally regulated by liver X receptor alpha (LXRα), a nuclear receptor. Quercetin is a widely distributed flavonoid in edible plants which prevented atherosclerosis in an animal model. We found that quercetin-3-O-glucuronide (Q3GA), a major quercetin metabolite after absorption from the digestive tract, enhanced ABCA1 expression, in vitro, via LXRα in macrophages. In addition, leaf extracts of a traditional Asian edible plant, Nelumbo nucifera (NNE), which contained abundant amounts of quercetin glycosides, significantly elevated plasma HDLC in mice. We are the first to present experimental evidence that Q3GA induced ABCA1 in macrophages, and to provide an alternative explanation to previous studies on arteriosclerosis prevention by quercetin. Show less

In mouse embryos, some primordial germ cells (PGCs) are eliminated by apoptosis, but the molecular pathways that lead to PGC survival versus apoptosis have not been fully characterized. Here, we found that REST (repressor element 1-silencing transcription factor), a transcription factor that binds a conserved regulatory element, NRSE/RE1, played a role in PGC survival. REST expression was higher in PGCs than in surrounding somatic cells. Moreover, in mouse embryos with a PGC-specific conditional REST mutation, the PGC population experienced more apoptosis and was significantly smaller than that in control embryos; these findings indicated that REST functioned in a cell-autonomous fashion that was critical for PGC survival. Several anti-apoptotic genes were among the previously identified REST-target gene candidates; moreover, some of these genes were downregulated in the REST-deficient PGCs. Mek5, which encodes a component in the a MAP kinase cascade, was one of these downregulated REST-target gene candidates, and a Mek5 mutation, like the REST mutation, caused an increase in PGC apoptosis; these finding suggested that REST promoted PGC survival via regulation of the Mek5 expression. Importantly, there were a normal number of PGCs in the REST mutants at birth, and both the male and female REST-mutant adults were fertile; these final observations revealed that the PGC population was very robust and could recover from a genetically induced reduction in cell number. Show less

The proteins encoded by all of the five cloned human EXT family genes (EXT1, EXT2, EXTL1, EXTL2, and EXTL3), members of the hereditary multiple exostoses gene family of tumor suppressors, are glycosyltransferases required for the biosynthesis of heparan sulfate. In the Caenorhabditis elegans genome, only two genes, rib-1 and rib-2, homologous to the mammalian EXT genes have been identified. Although rib-2 encodes an N-acetylglucosaminyltransferase involved in initiating the biosynthesis and elongation of heparan sulfate, the involvement of the protein encoded by rib-1 in the biosynthesis of heparan sulfate remains unclear. Here we report that RIB-1 is indispensable for the biosynthesis and for embryonic morphogenesis. Despite little individual glycosyltransferase activity by RIB-1, the polymerization of heparan sulfate chains was demonstrated when RIB-1 was coexpressed with RIB-2 in vitro. In addition, RIB-1 and RIB-2 were demonstrated to interact by pulldown assays. To investigate the functions of RIB-1 in vivo, we depleted the expression of rib-1 by deletion mutagenesis. The null mutant worms showed reduced synthesis of heparan sulfate and embryonic lethality. Notably, the null mutant embryos showed abnormality at the gastrulation cleft formation stage or later and arrested mainly at the 1-fold stage. Nearly 100% of the embryos died before L1 stage, although the differentiation of some of the neurons and muscle cells proceeded normally. Similar phenotypes have been observed in rib-2 null mutant embryos. Thus, RIB-1 in addition to RIB-2 is indispensable for the biosynthesis of heparan sulfate in C. elegans, and the two cooperate to synthesize heparan sulfate in vivo. These findings also show that heparan sulfate is essential for post-gastrulation morphogenic movement of embryonic cells and is indispensable for ensuring the normal spatial organization of differentiated tissues and organs. Show less

The formation of heparan sulfate (HS) chains is catalyzed by glycosyltransferases encoded by EXT (hereditary multiple exostosin gene) family members. Genetic screening for mutations affecting morphogen signaling pathways in Drosophila has identified three genes, tout-velu (ttv), sister of tout-velu (sotv), and brother of toutvelu (botv), which encode homologues of human EXT1, EXT2, and EXTL3, respectively. So far, in vitro glycosyltransferase activities have been demonstrated only for BOTV/DEXTL3, which harbors both N-acetylglucosaminyltransferase-I (GlcNAcT-I) and N-acetylglucosaminyltransferase-II (GlcNAcT-II) activities responsible for the chain initiation and elongation of HS, and no glucuronyltransferase-II (GlcAT-II) activity. Here we demonstrated that TTV/DEXT1 and SOTV/DEXT2 had GlcNAcT-II and GlcAT-II activities required for the biosynthesis of repeating disaccharide units of the HS backbone, and the coexpression of TTV with SOTV markedly augmented both glycosyltransferase activities when compared with the expression of TTV or SOTV alone. Moreover, the polymerization of HS was demonstrated on a linkage region analogue as an acceptor substrate by BOTV and an enzyme complex composed of TTV and SOTV (TTV-SOTV). In contrast to human, TTV-SOTV exhibited no GlcNAcT-I activity, indicating that BOTV/DEXT3, which is an EXT-Like gene and possesses GlcNAcT-I activity required for the initiation of HS, is indispensable for the biosynthesis of HS chains in Drosophila. Thus, all three EXT members in Drosophila, TTV, SOTV, and BOTV, are required for the biosynthesis of full-length HS in Drosophila. Show less

Comparative proteomic analysis was used to search for characteristic alterations in the sera of hepatocellular carcinoma (HCC) patients who had undergone curative radiofrequency ablation treatment. Serum samples collected from eight patients before and after treatment were subjected to 2-DE. Eighty-eight protein spots differentially expressed with the treatment were selected by clustering analysis, and the proteins were identified by MS based on MALDI-TOF/TOF analysis and public database searches. The statistical analysis suggested that four proteins decreased after treatment (pro-apolipoprotein, alpha2-HS glycoprotein, apolipoprotein A-IV precursor, and PRO1708/PRO2044, which is the carboxy terminal fragment of albumin) and that seven proteins were increased after treatment, including leucine-rich alpha2-glycoprotein and alpha1-antitrypsin. These data facilitate the identification of differentially expressed proteins that are involved in HCC carcinogenesis and provide candidate biomarkers for the development of diagnostic and therapeutic tools. Show less

Activation of Wnt signaling through beta-catenin mutations contributes to the development of hepatocellular carcinoma (HCC) and hepatoblastoma (HB). To explore the contribution of additional Wnt pathway molecules to hepatocarcinogenesis, we examined beta-catenin, AXIN1 and AXIN2 mutations in 73 HCCs and 27 HBs. beta-catenin mutations were detected in 19.2% (14 out of 73) HCCs and 70.4% (19 out of 27) HBs. beta-catenin mutations in HCCs were primarily point mutations, whereas more than half of the HBs had deletions. AXIN1 mutations occurred in seven (9.6%) HCCs and two (7.4%) HBs. The AXIN1 mutations included seven missense mutations, a 1 bp deletion, and a 12 bp insertion. The predominance of missense mutations found in the AXIN1 gene is different from the small deletions or nonsense mutations described previously. Loss of heterozygosity at the AXIN1 locus was present in four of five informative HCCs with AXIN1 mutations, suggesting a tumor suppressor function of this gene. AXIN2 mutations were found in two (2.7%) HCCs but not in HBs. Two HCCs had both AXIN1 and beta-catenin mutations, and one HCC had both AXIN2 and beta-catenin mutations. About half the HCCs with AXIN1 or AXIN2 mutations showed beta-catenin accumulation in the nucleus, cytoplasm or membrane. Overall, these data indicate that besides the approximately 20% of HCCs and 80% of HBs with beta-catenin mutations contributing to hepatocarcinogenesis, AXIN1 and AXIN2 mutations appear to be important in an additional 10% of HCCs and HBs. Show less