👤 Yukitoshi Takahashi

Because intractable itch reduces quality of life, understanding the fundamental mechanisms of itch is required to develop antipruritic treatments. Itch is mediated by peripheral sensory neurons, which originate from the neural crest (NC) during development. Itch-associated signaling molecules have been detected in genetically engineered animals and in cultures of peripheral neurons from dorsal root ganglia (DRG). Ethical difficulties collecting peripheral neurons from human DRG have limited analysis of itch in humans. This study describes a method of differentiating peripheral neurons from human induced pluripotent stem cells (hiPSCs) for physiological study of itch. This method resulted in the robust induction of p75 and HNK1 double-positive NC cells from hiPSCs. The expression of NC markers TFAP2A, SOX10 and SNAI1 increased during NC induction. The induction efficiency was nearly 90%, and human peripheral neurons expressing peripherin were efficiently differentiated from hiPSC-derived NC cells. Moreover, induced peripheral neurons expressed the sensory neuronal marker BRN3A and the itch-related receptors HRH1, MRGPRX1, IL31R and IL-4R. Calcium imaging analyses indicated that these peripheral neurons included sensory neurons responsive to itch-related stimuli such as histamine, BAM8-22, IL-31 and IL-4. These findings may enable detailed analyses of human DRG neurons and may result in new therapies for intractable itch. Show less

The relationship between the molecular profiling of circulating tumor cells (CTCs) and clinical factors is a challenge. In this study, we performed molecular detection and characterization of CTCs in patients with head and neck squamous cell carcinoma (HNSCC). CTCs captured by microfilter were analyzed for the expression of multiple epithelial markers (EPCAM, MET, KRT19, and EGFR) by RT-qPCR. The CTCs-positive samples were further analyzed for the expression of 10 genes (PIK3CA, CCND1, SNAI1, VIM, CD44, NANOG, ALDH1A1, CD47, CD274, and PDCD1LG2). Finally, we analyzed whether the molecular profiling of CTCs was associated with clinical factors. Twenty-eight (63.6%) of the 44 HNSCC patients were positive for at least one epithelial-related gene. CTC-positivity was significantly correlated with treatment resistance (p = 0.0363), locoregional recurrence (p = 0.0151), and a shorter progression-free survival (PFS) (p = 0.0107). Moreover, the expression of MET in CTCs was associated with a shorter PFS (p = 0.0426). Notably, patients with CD274-positive CTC showed prolonged PFS (p = 0.0346) and overall survival (p = 0.0378) compared to those with CD274-negative CTC. Our results suggest that molecular profiling characterized by the gene expression of CTCs influences clinical factors in patients with HNSCC. Show less

Objective- APOA5 variants are strongly associated with hypertriglyceridemia, as well as increased risks of cardiovascular disease and acute pancreatitis. Hypertriglyceridemia in apo AV dysfunction often aggravates by environmental factors such as high-carbohydrate diets or aging. To date, the molecular mechanisms by which these environmental factors induce hypertriglyceridemia are poorly defined, leaving the high-risk hypertriglyceridemia condition undertreated. Previously, we reported that LXR (liver X receptor)-SREBP (sterol regulatory element-binding protein)-1c pathway regulates large-VLDL (very low-density lipoprotein) production induced by LXR agonist. However, the pathophysiological relevance of the finding remains unknown. Approach and Results- Here, we reconstitute the environment-induced hypertriglyceridemia phenotype of human APOA5 deficiency in Apoa5 Show less

To assess the use of plasma free amino acids (PFAAs) as biomarkers for metabolic disorders, it is essential to identify genetic factors that influence PFAA concentrations. PFAA concentrations were absolutely quantified by liquid chromatography-mass spectrometry using plasma samples from 1338 Japanese individuals, and genome-wide quantitative trait locus (QTL) analysis was performed for the concentrations of 21 PFAAs. We next conducted a conditional QTL analysis using the concentration of each PFAA adjusted by the other 20 PFAAs as covariates to elucidate genetic determinants that influence PFAA concentrations. We identified eight genes that showed a significant association with PFAA concentrations, of which two, SLC7A2 and PKD1L2, were identified. SLC7A2 was associated with the plasma levels of arginine and ornithine, and PKD1L2 with the level of glycine. The significant associations of these two genes were revealed in the conditional QTL analysis, but a significant association between serine and the CPS1 gene disappeared when glycine was used as a covariate. We demonstrated that conditional QTL analysis is useful for determining the metabolic pathways predominantly used for PFAA metabolism. Our findings will help elucidate the physiological roles of genetic components that control the metabolism of amino acids. Show less

Rett syndrome (RTT) is a characteristic neurological disease presenting with regressive loss of neurodevelopmental milestones. Typical RTT is generally caused by abnormality of methyl-CpG binding protein 2 ( We performed WES on 77 Pathogenic or likely pathogenic single-nucleotide variants in 28 known genes were found in 39 of 77 (50.6%) patients. WES-based CNV analysis revealed pathogenic deletions involving six known genes (including Our study provides a new landscape including additional genetic variants contributing to RTT-like phenotypes, highlighting the importance of comprehensive genetic analysis. Show less

Gonadotropin-releasing hormone (GnRH) is secreted from hypothalamic neurons (GnRH neurons) and stimulates anterior pituitary gonadotrophs to synthesize and secrete gonadotropins. In addition to gonadotrophs, GnRH neurons also express GnRH receptors, and the autocrine action of GnRH is reportedly involved in the regulation of functions of GnRH neurons. There is accumulating evidence that extracellular signal-regulated kinase (ERK), one of mitogen-activated protein kinases (MAPKs), is activated by GnRH and involved in various effects of GnRH in GnRH neurons. In the present study, we performed microarray analysis to examine the types of genes whose expression was regulated by GnRH in immortalized mouse GnRH neurons (GT1-7 cells). We found that 257 genes among 55,681 genes examined were up-regulated after 30-min treatment of GT1-7 cells with GnRH. These up-regulated genes included four dual-specificity MAPK phosphatases (DUSPs), DUSP1, DUSP2, DUSP5, and DUSP6. Reverse transcription-polymerase chain reaction analysis confirmed that the mRNA levels of DUSP5 and DUSP6 were robustly increased within 30 min. U0126, an inhibitor of ERK activation, completely inhibited the increases in the mRNA levels of DUSP5 and DUSP6. Immunoblotting analysis revealed that ERK activation peaked at 5 min and declined steeply at 60 min, whereas DUSP5 and DUSP6 proteins were increased from 60 min. It was notable that down-regulation of DUSP6 augmented GnRH-induced ERK activation approximately 1.7-fold at 60 min. These results suggested that the up-regulation of DUSP6 regulates the duration of ERK activation at least in part. Show less

Genome-wide association studies (GWASs) have identified several susceptibility loci for bipolar disorder (BD) and shown that the genetic architecture of BD can be explained by polygenicity, with numerous variants contributing to BD. In the present GWAS (Phase I/II), which included 2964 BD and 61 887 control subjects from the Japanese population, we detected a novel susceptibility locus at 11q12.2 (rs28456, P=6.4 × 10 Show less

Several inherited arrhythmias, including Brugada syndrome and arrhythmogenic cardiomyopathy, primarily affect the right ventricle and can lead to sudden cardiac death. Among many differences, right and left ventricular cardiomyocytes derive from distinct progenitors, prompting us to investigate how embryonic programming may contribute to chamber-specific conduction and arrhythmia susceptibility. Here, we show that developmental perturbation of Wnt signaling leads to chamber-specific transcriptional regulation of genes important in cardiac conduction that persists into adulthood. Transcriptional profiling of right versus left ventricles in mice deficient in Wnt transcriptional activity reveals global chamber differences, including genes regulating cardiac electrophysiology such as Gja1 and Scn5a. In addition, the transcriptional repressor Hey2, a gene associated with Brugada syndrome, is a direct target of Wnt signaling in the right ventricle only. These transcriptional changes lead to perturbed right ventricular cardiac conduction and cellular excitability. Ex vivo and in vivo stimulation of the right ventricle is sufficient to induce ventricular tachycardia in Wnt transcriptionally inactive hearts, while left ventricular stimulation has no effect. These data show that embryonic perturbation of Wnt signaling in cardiomyocytes leads to right ventricular arrhythmia susceptibility in the adult heart through chamber-specific regulation of genes regulating cellular electrophysiology. 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

Despite increasing research in type 2 diabetes mellitus (T2D), there are few studies showing the impact of the poor glycemic control on biological processes occurring in T2D. In order to identify potential genes related to poorly/well-controlled patients with T2D, our strategy of investigation included a primary screen by microarray (Human Genome U133) in a small group of individuals followed by an independent validation in a greater group using RT-qPCR. Ninety patients were divided as follows: poorly controlled T2D (G1), well-controlled T2D (G2), and normoglycemic individuals (G3). After using affy package in R, differentially expressed genes (DEGs) were prospected as candidate genes potentially relevant for the glycemic control in T2D patients. After validation by RT-qPCR, the obtained DEGs were as follows-G1 + G2 versus G3: Show less

Age-related macular degeneration (AMD) is a major cause of blindness in the elderly. Previous sequencing studies of AMD susceptibility genes have revealed the association of rare coding variants in CFH, CFI, C3 and C9 in European population; however, the impact of rare or low-frequency coding variants on AMD susceptibility in other populations is largely unknown. To identify the role of low-frequency coding variants on exudative AMD susceptibility in a Japanese population, we analysed the association of coding variants of 34 AMD candidate genes in the two-stage design by a multiplex PCR-based target sequencing method. We used a total of 2,886 (1st: 827, 2nd: 2,059) exudative AMD cases including typical AMD, polypoidal choroidal vasculopathy, and retinal angiomatous proliferation and 9,337 (1st: 3,247 2nd: 6,090) controls. Gene-based analysis found a significant association of low-frequency variants (minor allele frequency (MAF) < 0.05) in CETP, C2 and CFB. The association of CETP remained after conditioned with all known genome-wide association study (GWAS) associated variants. In addition, when we included only disruptive variants, enrichment of rare variants (MAF < 0.01) was also observed after conditioned with all GWAS associated variants (P = 1.03 × 10−6, odds ratio (OR) = 2.48). Haplotype and conditional analysis of the C2-CFB-SKIV2L locus showed a low-frequency variant (R74H) in CFB would be individually associated with AMD susceptibility independent of the GWAS associated SNP. These findings highlight the importance of target sequencing to reveal the impact of rare or low-frequency coding variants on disease susceptibility in different ethnic populations. Show less

Fetal organs require much lipid for growth, but the cord blood had low TG concentrations, compared to adult serum. We investigated the association between the concentration of apolipoprotein A-V (apoA-V) and lipid profile in cord blood and neonatal serum. ApoA-V was identified as an important determinant of plasma triglyceride concentrations. We sought to determine the association between serum apoA-V concentrations and lipoprotein profile in preterm infants and its early postnatal change. Sixty-three neonates (35 males and 28 females; 15 term and 48 preterm) were included. Serum lipoprotein profile and apoA-V concentrations were determined at birth and 1 month. Cord blood apoA-V concentrations in appropriate-for-gestational age infants were extremely low (13.1 ± 3.4 ng/mL in term infants, 4.4 ± 0.9 ng/mL in preterm infants) compared with adult values, and those of small-for-gestational age infants were further low (6.4 ± 4.2 ng/mL, 2.2 ± 1.3 ng/mL, respectively). During the first month, serum apoA-V concentration markedly increased, and the concentration of preterm appropriate-for-gestational age infants caught up, whereas that of preterm small-for-gestational age infants did not. At birth, apoA-V concentration positively correlated with gestational age (r = 0.354, P = .0069) but not with birth weight Z-score. ApoA-V concentration had a positive association with very low-density lipoprotein triglyceride concentrations (r = 0.646, P < .0001), and the relationships still remained at 1 month (r = 0.283, P = .0348). ApoA-V in neonates was unique in its serum concentration and in the association with lipoprotein profile. Show less

Basaloid squamous cell carcinoma (BSCC) is a rare and poorly differentiated variant of typical squamous cell carcinoma, and is characterised in part by activation of the Wnt signalling pathway. We previously demonstrated that constitutive activation of the Wnt signalling pathway by epigenetic silencing of secreted frizzled-related protein 4 (SFRP4) is observed in this tumour. Increasing evidence shows that the Wnt signalling pathway cross-talks with other developmental pathways, including the Hedgehog (HH) pathway. The HH pathway is stimulated by inactivating mutations of PTCH1, which have a well-described oncogenic role in basal cell carcinoma (BCC) of the skin. We employed polymerase chain reaction followed by direct sequencing to detect inactivating mutations of PTCH1 using archival tissue samples of 30 oesophageal BSCCs. The frequency of PTCH1 mutation was compared to that of Wnt component genes that we reported previously. We found PTCH1 mutations in 53.3% (16/30) of cases, revealing T1195S as a hotspot mutation. This frequency is quite high for cancers other than BCC of the skin, and PTCH1 mutations were almost mutually exclusive with mutations in APC, Axin1 and Axin2. Considering the fact that activation of Wnt signalling via down-regulation of APC and SFRP5 due to promoter methylation is observed in BCC of the skin, Wnt signalling activation in oesophageal BSCC might be a secondary effect of the PTCH1-inactivating mutations. These findings suggest that the HH and Wnt pathways coordinately contribute to tumourigenesis in oesophageal BSCC. Furthermore, this study provides a potential therapeutic application for HH pathway inhibitors in oesophageal BSCC with highly malignant potential. Show less

Special AT-rich sequence binding protein 2 (SATB2) is an evolutionarily conserved transcription factor that has multiple roles in neuronal development, osteoblast differentiation, and craniofacial patterning. SATB2 binds to the nuclear matrix attachment region, and regulates the expression of diverse sets of genes by altering chromatin structure. Recent studies have reported that high expression of SATB2 is associated with favorable prognosis in colorectal and laryngeal cancer; however, it remains uncertain whether SATB2 has tumor-suppressive functions in cancer cells. In this study, we examined the effects of SATB2 expression on the malignant characteristics of colorectal cancer cells. Expression of SATB2 repressed the proliferation of cancer cells in vitro and in vivo, and also suppressed their migration and invasion. Extracellular signal-regulated kinase 5 (ERK5) is a mitogen-activated protein kinase that is associated with an aggressive phenotype in various types of cancer. SATB2 expression reduced the activity of ERK5, and constitutive activation of ERK5 restored the proliferation, anchorage-independent growth, migration and invasion of SATB2-expressing cells. Our results demonstrate the existence of a novel regulatory mechanism of SATB2-mediated tumor suppression via ERK5 inactivation. Show less

Peyer's patches (PPs), which are covered by specialized follicle-associated epithelium (FAE) including M cells, play a central role in immune induction in the gastrointestinal tract. This study is to investigate a new molecule to characterize PPs. We generated a monoclonal antibody (mAb 10-15-3-3) that specifically reacts to the epithelium of PPs and isolated lymphoid follicles. Target antigen was analyzed by immunoprecipitation and mass spectrometry. Localization and expression of target antigen were evaluated by immunofluorescence, in situ hybridization and real-time PCR. Immunoprecipitation and mass spectrometry revealed that mAb 10-15-3-3 recognized apolipoprotein A-IV (ApoA-IV), a well-known lipid transporter; this finding was confirmed by the specific reactivity of mAb 10-15-3-3 to cells transfected with the murine ApoA-IV gene. Immunofluorescence using mAb 10-15-3-3 showed intestinal localization of ApoA-IV, in which strong expression of the ApoA-IV protein occurred throughout the entire intestinal epithelium during developing period before weaning but was restricted to the FAE in adult mice. In support of these findings, in situ hybridization showed strong expression of the ApoA-IV gene throughout the entire intestinal epithelium during developing period before weaning, but this expression was restricted to the FAE predominantly and the tips of villi to a lesser extent in adult mice. Deficiency of ApoA-IV had no effect on the organogenesis of PP in mice. Our current results reveal ApoA-IV as a novel FAE-specific marker especially in the upper small intestine of adult mice. Show less

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare variant of typical squamous cell carcinoma (SCC) associated with poor survival. A characteristic feature is nuclear accumulation of β-catenin, without a mutation of the gene. We studied the methylation status of Wnt antagonist genes, such as secreted frizzled-related protein (sFRP) gene family members, Wnt inhibitory factor-1 (WIF-1), Dickkopf-1 (Dkk-1), and human Dapper protein-1 (HDPR-1), and alterations of the APC, Axin1, and Axin2 genes in 30 cases of esophageal BSCC. β-catenin and sFRP (sFRP-1, sFRP-2, sFRP-4, sFRP-5) protein expression was examined by immunohistochemistry. APC, Axin1, and Axin2 gene mutations were detected in 3, 2, and 2 cases, respectively, and 6 cases (20 %) harbored at least 1 alteration in these genes. Methylation of the sFRP-2 promoter region was observed in all cases, and methylation was frequent in sFRP-1 and sFRP-5, but infrequent in Dkk-1, WIF-1, sFRP-4, and HDPR-1. sFRP-2 expression was almost completely absent in 25 cases (83 %), consistent with the methylation status. Nuclear accumulation of β-catenin was observed in all cases. sFRP-5 expression was associated with a low nuclear β-catenin labeling index. These results show that sFRP-2 is a target gene of hypermethylation in esophageal BSCC and suggest that sFRP-2 might contribute to BSCC tumorigenesis through the Wnt/β-catenin signaling pathway. Show less

Valproic acid, which is widely used to treat various types of epilepsy, may cause severe hyperammonemia. However, the mechanism responsible for this side effect is not readily apparent. Polymorphisms in the genes encoding carbamoyl-phosphate synthase 1 (CPS1) and N-acetylglutamate synthase (NAGS) were recently reported to be risk factors for the development of hyperammonemia during valproic acid-based therapy. This study aimed to examine the influence of patient characteristics, including polymorphisms in CPS1 4217C>A and NAGS -3064C>A, on the development of hyperammonemia in Japanese pediatric epilepsy patients. The study included 177 pediatric epilepsy patients. The presence of a 4217C>A polymorphism in CPS1 was determined using an allele-specific polymerase chain reaction (PCR)-based method, and the presence of a -3064C>A polymorphism in NAGS was determined using a PCR-based restriction fragment length polymorphism method. Hyperammonemia was defined as a plasma ammonia level exceeding 200 μg/dL. We observed a significant difference between the combination of valproic acid with phenytoin and the development of hyperammonemia in both univariate and multivariate analyses. With regard to the CPS1 4217C>A polymorphism, we did not observe a significant association with the development of hyperammonemia. In conclusion, CPS1 4217C>A polymorphism may not be associated with the development of hyperammonemia in Japanese population. Show less

Known genetic loci explain only a small proportion of the familial relative risk of colorectal cancer (CRC). We conducted a genome-wide association study of CRC in East Asians with 14,963 cases and 31,945 controls and identified 6 new loci associated with CRC risk (P = 3.42 × 10(-8) to 9.22 × 10(-21)) at 10q22.3, 10q25.2, 11q12.2, 12p13.31, 17p13.3 and 19q13.2. Two of these loci map to genes (TCF7L2 and TGFB1) with established roles in colorectal tumorigenesis. Four other loci are located in or near genes involved in transcriptional regulation (ZMIZ1), genome maintenance (FEN1), fatty acid metabolism (FADS1 and FADS2), cancer cell motility and metastasis (CD9), and cell growth and differentiation (NXN). We also found suggestive evidence for three additional loci associated with CRC risk near genome-wide significance at 8q24.11, 10q21.1 and 10q24.2. Furthermore, we replicated 22 previously reported CRC-associated loci. Our study provides insights into the genetic basis of CRC and suggests the involvement of new biological pathways. Show less

Transcription factor Hesr family genes are important in neuronal development. We demonstrated previously that HESR1 and HESR2 modified expression of the dopamine transporter (DAT) reporter gene. HESR-family genes have been investigated in development, but their functions, especially in relation to behaviors regulated by dopamine, in adult animals remain unclear. In the present study, we investigated the effects of Hesr1 and Hesr2 on behavior. A behavioral test battery to examine spontaneous activity, anxiety-like behavior, aggressive behavior, pain sensitivity, and sensorimotor gating was conducted in Hesr1 and Hesr2 knockout (KO) mice. Enhanced prepulse inhibition (PPI), which is a form of sensorimotor gating, was observed in only Hesr1 KO mice; other behavioral traits were mostly comparable to wild-type animals in both the Hesr1 and the Hesr2 KO lines. Next, we used a dopamine agonist, apomorphine, to confirm the involvement of the dopaminergic system. Injection of apomorphine reduced the enhanced PPI in Hesr1 KO mice. Additionally, dose-dependent sensitivity to the agonist was lower in the Hesr1 KO mice than in wild-type mice, suggesting that the enhanced PPI resulted from this alteration in dopamine sensitivity. Furthermore, DAT mRNA was downregulated in Hesr1 KO mice, whereas the dopamine D1 and D2 receptors were comparable. These findings suggest Hesr1 to be a novel factor that affects dopamine sensitivity and the sensorimotor gating system. Show less

Mammalian tribbles homolog 1 (TRIB1) regulates hepatic lipogenesis and is genetically associated with plasma triglyceride (TG) levels and cholesterol, but the molecular mechanisms remain obscure. We explored these mechanisms in mouse livers transfected with a TRIB1 overexpression, a shRNA template or a control (LacZ) adenovirus vector. The overexpression of TRIB1 reduced, whereas induction of the shRNA template increased, plasma glucose, TG, and cholesterol and simultaneously hepatic TG and glycogen levels. The involvement of TRIB1 in hepatic lipid accumulation was supported by the findings of a human SNP association study. A TRIB1 SNP, rs6982502, was identified in an enhancer sequence, modulated enhancer activity in reporter gene assays, and was significantly (P=9.39 × 10(-7)) associated with ultrasonographically diagnosed non-alcoholic fatty liver disease in a population of 5570 individuals. Transcriptome analyses of mouse livers revealed significant modulation of the gene sets involved in glycogenolysis and lipogenesis. Enforced TRIB1 expression abolished CCAAT/enhancer binding protein A (CEBPA), CEBPB, and MLXIPL proteins, whereas knockdown increased the protein level. Levels of TRIB1 expression simultaneously affected MKK4 (MAP2K4), MEK1 (MAP2K1), and ERK1/2 (MAPK1/3) protein levels and the phosphorylation of JNK, but not of ERK1/2. Pull-down and mammalian two-hybrid analyses revealed novel molecular interaction between TRIB1 and a hepatic lipogenic master regulator, MLXIPL. Co-expression of TRIB1 and CEBPA or MLXIPL reduced their protein levels and proteasome inhibitors attenuated the reduction. These data suggested that the modulation of TRIB1 expression affects hepatic lipogenesis and glycogenesis through multiple molecular interactions. Show less

Gastric neoplasia of chief cell-predominant type (GN-CCP) has been reported as a new, rare variant of gastric tumor. GN-CCPs were defined as tumors consisting of irregular anastomosing glands of columnar cells mimicking chief cells of fundic gland with nuclear atypia and prolapse-type submucosal involvement. We comparatively evaluated clinicopathologic features between 31 GN-CCPs and 130 cases of conventional gastric adenocarcinoma invading into submucosa (CGA-SM) in addition to nuclear β-catenin immunolabeling and direct sequencing of members of the Wnt/β-catenin pathway, CTNNB1, APC, and AXIN, in a subset of these tumors. GN-CCP presented as small protruded lesions located in the upper third of the stomach, with minimal involvement into the submucosa and rare lymphovascular invasion. None of the lesions have demonstrated a recurrence of disease or metastasis on follow-up. Nuclear β-catenin immunolabeling was higher in GN-CCP (labeling index [LI]: median, 19.3%; high expresser [LI >30%], 7/27 cases [26%]) than CGA-SM (median LI, 14.7%; high expresser, 1/19 cases [6%]). Missense mutation of APC was observed in 1 GN-CCP but not CGA-SM. Missense or nonsense mutations of CTNNB1 and AXIN1 were higher in GN-CCPs (14.8%, both) than CGA-SMs (5.3%, both). Missense mutations of AXIN2 were higher in GN-CCPs (25.9%) than in CGA-SMs (10.5%). Overall, 14 (51.9%) of 27 GN-CCPs and 5 (26.3%) of 19 CGA-SM cases harbored at least 1 of these gene mutations. In conclusion, GN-CCPs as a unique variant of nonaggressive tumor are characterized by nuclear β-catenin accumulation and mutation of CTNNB1 or AXIN gene, suggesting activation of the Wnt/β-catenin pathway. Show less

Multidrug resistance protein 2 (MRP2, ABCC2) is localized to the apical membrane of hepatocytes and played an important role in the biliary excretion of a broad range of endogenous and xenobiotic compounds and drugs, such as pravastatin. However, the effects of statins on MRP2 in the liver and the precise mechanisms of their actions have been obscure. The goal of this study was to determine the regulatory molecular mechanism for statin-induced MRP2 expression in hepatocytes. In vitro and in vivo studies suggested that pitavastatin increased MRP2 expression. Pitavastatin promoted liver X receptor (LXR) α/β translocation from the cytosol to nuclei, resulting in LXR activation. Deletion and mutational analysis suggested that the potential sterol regulatory element (SRE) played a major role in the observed modulation of MRP2 expression by pitavastatin. Furthermore pitavastatin increased the protein-DNA complex, and when SRE was mutated, stimulation of the protein-DNA complex by pitavastatin was decreased. It was demonstrated that pitavastatin upregulated MRP2 expression by an SREBP regulatory pathway in hepatocytes and that the actions of statins may lead to improve the biliary excretion of MRP2 substrates. Show less

Evasion of apoptosis, which enables cells to survive and proliferate under metabolic stress, is one of the hallmarks of cancer. We have recently reported that SH3GLB1/Bif-1 functions as a haploinsufficient tumor suppressor to prevent the acquisition of apoptosis resistance and malignant transformation during Myc-driven lymphomagenesis. SH3GLB1 is a membrane curvature-inducing protein that interacts with BECN1 though UVRAG and regulates the post-Golgi trafficking of membrane-integrated ATG9A for autophagy. At the premalignant stage, allelic loss of Sh3glb1 enhances Myc-induced chromosomal instability and results in the upregulation of anti-apoptotic proteins, including MCL1 and BCL2L1. Notably, we found that Sh3glb1 haploinsufficiency increases mitochondrial mass in overproliferated prelymphomatous Eμ-Myc cells. Moreover, loss of Sh3glb1 suppresses autophagy-dependent mitochondrial clearance (mitophagy) in PARK2/Parkin-expressing mouse embryonic fibroblasts (MEFs) treated with the mitochondrial uncoupler CCCP. Interestingly, PARK2-expressing Sh3glb1-deficient cells accumulate ER-associated immature autophagosome-like structures after treatment with CCCP. Taken together, we propose a model of mitophagy in which SH3GLB1 together with the class III phosphatidylinositol 3-kinase complex II (PIK3C3CII) (PIK3R4-PIK3C3-BECN1-UVRAG) regulates the trafficking of ATG9A-containing Golgi-derived membranes (A9(+)GDMs) to damaged mitochondria for autophagosome formation to counteract oncogene-driven tumorigenesis. Show less

Obesity is a disorder with a complex genetic etiology, and its epidemic is a worldwide problem. Although multiple genetic loci associated with body mass index, the most common measure of obesity, have been identified in European populations, few studies have focused on Asian populations. Here we report a genome-wide association study and replication studies with 62,245 east Asian subjects, which identified two new body mass index-associated loci in the CDKAL1 locus at 6p22 (rs2206734, P = 1.4 × 10(-11)) and the KLF9 locus at 9q21 (rs11142387, P = 1.3 × 10(-9)), as well as several previously reported loci (the SEC16B, BDNF, FTO, MC4R and GIPR loci, P < 5.0 × 10(-8)). We subsequently performed gene-gene interaction analyses and identified an interaction (P = 2.0 × 10(-8)) between a SNP in the KLF9 locus (rs11142387) and one in the MSTN (also known as GDF8) locus at 2q32 (rs13034723). These findings should provide useful insights into the etiology of obesity. Show less

Mixed-lineage-leukemia (MLL) fusion oncogenes are intimately involved in acute leukemia and secondary therapy-related acute leukemia. To understand MLL-rearranged leukemia, several murine models for this disease have been established. However, the mouse leukemia derived from mouse hematopoietic stem cells (HSCs) may not be fully comparable with human leukemia. Here we developed a humanized mouse model for human leukemia by transplanting human cord blood-derived HSCs transduced with an MLL-AF10 oncogene into a supra-immunodeficient mouse strain, NOD/Shi-scid, IL-2Rγ(-/-) (NOG) mice. Injection of the MLL-AF10-transduced HSCs into the liver of NOG mice enhanced multilineage hematopoiesis, but did not induce leukemia. Because active mutations in ras genes are often found in MLL-related leukemia, we next transduced the gene for a constitutively active form of K-ras along with the MLL-AF10 oncogene. Eight weeks after transplantation, all the recipient mice had developed acute monoblastic leukemia (the M5 phenotype in French-American-British classification). We thus successfully established a human MLL-rearranged leukemia that was derived in vivo from human HSCs. In addition, since the enforced expression of the mutant K-ras alone was insufficient to induce leukemia, the present model may also be a useful experimental platform for the multi-step leukemogenesis model of human leukemia. Show less

Trigonella foenum-graecum (fenugreek) can ameliorate dyslipidemia, but the detailed mechanism is unclear. In this study, we examined the effects of fenugreek on hepatic lipid metabolism, particularly lipogenesis, which is enhanced in obesity and diabetes, in diabetic obese KK-Ay mice. KK-Ay mice were fed a control high-fat diet (HFD; 60% of energy as fat) (C group) or an HFD containing 0.5% or 2% fenugreek (0.5F and 2.0F groups, respectively) for 4 wk. Hepatic and plasma TG and mRNA expression levels of lipogenic genes were lower in the 2.0F group at 4 wk (P < 0.05), but not in the 0.5F group, than in the C group. The hydrolyzed saponin fraction, but not the saponin fraction per se, in fenugreek inhibited the accumulation of TG in HepG2 cells. We fractionated the hydrolyzed saponin into 15 fractions by HPLC and examined the effect of these fractions on TG accumulation in HepG2 cells. Fraction 11 inhibited TG accumulation in HepG2 cells and we determined by liquid chromatography tandem MS that the active substance contained in fraction 11 is diosgenin. Diosgenin (5 and 10 μmol/L) inhibited the accumulation of TG and the expression of lipogenic genes in HepG2 cells. Moreover, diosgenin inhibited the transactivation of liver-X-receptor-α, as measured using a luciferase assay system and by gel mobility shift assay. These findings suggest that fenugreek ameliorates dyslipidemia by decreasing the hepatic lipid content in diabetic mice and that its effect is mediated by diosgenin. Fenugreek, which contains diosgenin, may be useful for the management of diabetes-related hepatic dyslipidemias. Show less

Allergic rhinitis is a global health problem that causes major illnesses and disability worldwide. Allergen-specific immunotherapy (SIT) is the only available treatment that can alter the natural course of allergic disease. However, the precise mechanism underlying allergen-SIT is not well understood. The aim of the current study was to identify protein expression signatures reflective of allergen-SIT-more specifically, sublingual immunotherapy (SLIT). Serum was taken twice from patients with seasonal allergic rhinitis caused by Japanese cedar: once before the pollen season and once during the season. A total of 25 patients was randomly categorized into a placebo-treated group and an active-treatment group. Their serum protein profiles were analyzed by 2-dimensional electrophoresis. Sixteen proteins were found to be differentially expressed during the pollen season. Among the differentially expressed proteins, the serum levels of complement C4A, apolipoprotein A-IV (apoA-IV), and transthyretin were significantly increased in SLIT-treated patients but not in placebo-treated patients. Among these proteins, the serum levels of apoA-IV correlated with the clinical symptom-medication scores (r = -0.635; P < .05) and with quality of life scores (r = -0.516; P < .05) in the case of SLIT-treated patients. The amount of histamine released from the basophils in vitro was greatly reduced after the addition of recombinant apoA-IV in the medium (P < .01). Our data will increase the understanding of the mechanism of SLIT and may provide novel insights into the treatment of allergic rhinitis. Show less

The synthesis and SAR studies of 3- and 4-substituted 7-hydroxycoumarins as novel 17beta-HSD3 inhibitors are discussed. The most potent compounds from this series exhibited low nanomolar inhibitory activity with acceptable selectivity versus other 17beta-HSD isoenzymes and nuclear receptors. Show less

Epigenetic modifications of chromatin play an important role in the regulation of gene expression. KMT4/Dot1 is a conserved histone methyltransferase capable of methylating chromatin on Lys79 of histone H3 (H3K79). Here we report the identification of a multisubunit Dot1 complex (DotCom), which includes several of the mixed lineage leukemia (MLL) partners in leukemia such as ENL, AF9/MLLT3, AF17/MLLT6, and AF10/MLLT10, as well as the known Wnt pathway modifiers TRRAP, Skp1, and beta-catenin. We demonstrated that the human DotCom is indeed capable of trimethylating H3K79 and, given the association of beta-catenin, Skp1, and TRRAP, we investigated, and found, a role for Dot1 in Wnt/Wingless signaling in an in vivo model system. Knockdown of Dot1 in Drosophila results in decreased expression of a subset of Wingless target genes. Furthermore, the loss of expression for the Drosophila homologs of the Dot1-associated proteins involved in the regulation of H3K79 shows a similar reduction in expression of these Wingless targets. From yeast to human, specific trimethylation of H3K79 by Dot1 requires the monoubiquitination of histone H2B by the Rad6/Bre1 complex. Here, we demonstrate that depletion of Bre1, the E3 ligase required for H2B monoubiquitination, leads specifically to reduced bulk H3K79 trimethylation levels and a reduction in expression of many Wingless targets. Overall, our study describes for the first time the components of DotCom and links the specific regulation of H3K79 trimethylation by Dot1 and its associated factors to the Wnt/Wingless signaling pathway. Show less