Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.bbrep.2021.100984

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

Ascorbic acid (AA, vitamin C) serves as a cofactor for ten-eleven translocation (TET) enzymes and induces DNA demethylation in vitro. However, its role in DNA demethylation in vivo remains unclear. We previously reported that DNA demethylation in the mouse liver was enhanced during the suckling period. Therefore, we hypothesized that DNA demethylation is enhanced in an AA-dependent manner during the suckling period. To examine our hypothesis, we employed wild-type (WT) mice, which synthesize AA, and senescence marker protein-30/gluconolactonase (SMP30/GNL) knockout (KO) mice, which cannot synthesize AA, and analyzed the DNA methylation status in the livers of offspring in both the suckling period and adulthood. SMP30/GNL KO offspring showed DNA hypermethylation in the liver possibly due to low plasma and hepatic AA levels during the suckling period despite the administration of rescue-dose AA to dams. Furthermore, DNA hypermethylation of the fibroblast growth factor 21 gene (Fgf21), a PPARα target gene, persisted into adulthood. In contrast, a high-dose AA administration to SMP30/GNL KO dams during the lactation period restored DNA demethylation in the livers of offspring. Even though a slight increase was observed in plasma AA levels with the administration of rescue-dose AA to WT dams during the gestation and lactation periods, DNA demethylation in the livers of offspring was minimally enhanced. The present results demonstrate that AA intake during the suckling period is required for proper DNA demethylation in the liver.

DOI： 10.1038/s41598-020-77962-7

PubMed

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

Our understanding of the spatiotemporal regulation of cardiogenesis is hindered by the difficulties in modeling this complex organ currently by in vitro models. Here we develop a method to generate heart organoids from mouse embryonic stem cell-derived embryoid bodies. Consecutive morphological changes proceed in a self-organizing manner in the presence of the laminin-entactin (LN/ET) complex and fibroblast growth factor 4 (FGF4), and the resulting in vitro heart organoid possesses atrium- and ventricle-like parts containing cardiac muscle, conducting tissues, smooth muscle and endothelial cells that exhibited myocardial contraction and action potentials. The heart organoids exhibit ultrastructural, histochemical and gene expression characteristics of considerable similarity to those of developmental hearts in vivo. Our results demonstrate that this method not only provides a biomimetic model of the developing heart-like structure with simplified differentiation protocol, but also represents a promising research tool with a broad range of applications, including drug testing.

DOI： 10.1038/s41467-020-18031-5

PubMed

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

The lumicrine system is a postulated signaling system in which testis-derived (upstream) secreted factors enter the male reproductive tract to regulate epididymal (downstream) pathways required for sperm maturation. Until now, no lumicrine factors have been identified. We demonstrate that a testicular germ-cell-secreted epidermal growth factor-like protein, neural epidermal growth factor-like-like 2 (NELL2), specifically binds to an orphan receptor tyrosine kinase, c-ros oncogene 1 (ROS1), and mediates the differentiation of the initial segment (IS) of the caput epididymis. Male mice in which Nell2 had been knocked out were infertile. The IS-specific secreted proteases, ovochymase 2 (OVCH2) and A disintegrin and metallopeptidase 28 (ADAM28), were expressed upon IS maturation, and OVCH2 was required for processing of the sperm surface protein ADAM3, which is required for sperm fertilizing ability. This work identifies a lumicrine system essential for testis-epididymis-spermatozoa (NELL2-ROS1-OVCH2-ADAM3) signaling and male fertility.

DOI： 10.1126/science.aay5134

PubMed

Language：English  

DOI： 10.15252/embr.201948251

PubMed

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

The placenta is critical in mammalian embryonic development because the embryo's supply of nutrients, including amino acids, depends solely on mother-to-embryo transport through it. However, the molecular mechanisms underlying this amino acid supply are poorly understood. In this study, we focused on system A amino acid transporters Slc38a1/SNAT1, Slc38a2/SNAT2, and Slc38a4/SNAT4, which carry neutral, short-side-chain amino acids, to determine their involvement in placental or embryonic development. A triple-target CRISPR screen identified Slc38a4/SNAT4 as the critical amino acid transporter for placental development in mice. We established mouse lines from the CRISPR founders with large deletions in Slc38a4 and found that, consistent with the imprinted paternal expression of Slc38a4/SNAT4 in the placenta, paternal knockout (KO) but not maternal KO of Slc38a4/SNAT4 caused placental hypoplasia associated with reduced fetal weight. Immunostaining revealed that SNAT4 was widely expressed in differentiating cytotrophoblasts and maturing trophoblasts at the maternal-fetal interface. A blood metabolome analysis revealed that amino acid concentrations were globally reduced in Slc38a4/SNAT4 mutant embryos. These results indicated that SNAT4-mediated amino acid transport in mice plays a major role in placental and embryonic development. Given that expression of Slc38a4 in the placenta is conserved in other species, our Slc38a4/SNAT4 mutant mice could be a promising model for the analysis of placental defects leading to intrauterine growth restriction in mammals.

DOI： 10.1073/pnas.1907884116

PubMed

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

DOI： 10.1099/ijsem.0.003549.

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

Recent genetic studies have suggested that tumor suppressor genes are often silenced during carcinogenesis via epigenetic modification caused by methylation of promoter CpG islands. Here, we characterized genes inactivated by DNA methylation in human hepatocellular carcinoma (HCC) to identify the genes and pathways involved in DNA methylation in hepatocellular carcinoma.
We identified CXCL2, an immune-related chemokine, decreased in hepatocellular carcinoma and the regulation mechanism may be controlled by methylation. Further studies should be warranted to examine if and to what extent the gene is actually suppressed by methylation and if there is a possibility that the CXCL2 axis plays a role for diagnosis and treatment of hepatocellular carcinoma.

DOI： 10.1007/s00432-018-2824-0

PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Nature America, Inc  

X-chromosome inactivation (XCI) is an essential epigenetic process in female mammalian development. Although cell-based studies suggest the potential importance of the Ftx long non-protein-coding RNA (lncRNA) in XCI, its physiological roles in vivo remain unclear. Here we show that targeted deletion of X-linked mouse Ftx lncRNA causes eye abnormalities resembling human microphthalmia in a subset of females but rarely in males. This inheritance pattern cannot be explained by X-linked dominant or recessive inheritance, where males typically show a more severe phenotype than females. In Ftx-deficient mice, some X-linked genes remain active on the inactive X, suggesting that defects in random XCI in somatic cells cause a substantially female-specific phenotype. The expression level of Xist, a master regulator of XCI, is diminished in females homozygous or heterozygous for Ftx deficiency. We propose that loss-of-Ftx lncRNA abolishes gene silencing on the inactive X chromosome, leading to a female microphthalmia-like phenotype.

DOI： 10.1038/s41467-018-06327-6

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：FRONTIERS MEDIA SA  

Many risk factors related to the development of non-alcoholic fatty liver disease (NAFLD) have been proposed, including the most well-known of diabetes and obesity as well as periodontitis. As periodontal pathogenic bacteria produce endotoxins, periodontal treatment can result in endotoxemia. The aim of this study was to investigate the effects of intravenous, sonicated Porphyromonas gingivalis (Pg) injection on glucose/lipid metabolism, liver steatosis, and gut microbiota in mice. Endotoxemia was induced in C57BL/6J mice (8 weeks old) by intravenous injection of sonicated Pg; Pg was deactivated but its endotoxin remained. The mice were fed a high-fat diet and administered sonicated Pg (HFPg) or saline (HFco) injections for 12 weeks. Liver steatosis, glucose metabolism, and gene expression in the liver were evaluated. 16S rRNA gene sequencing with metagenome prediction was performed on the gut microbiota. Overall, intravenous injection of sonicated Pg caused impaired glucose tolerance, insulin resistance, and liver steatosis in mice fed high-fat diets. Thus, blood infusion of Pg contributes to NAFLD and alters the gut microbiota.

DOI： 10.3389/fmicb.2018.02470

Web of Science

Event date： 2019.12

Language：Japanese   Presentation type：Poster presentation  

Venue：福岡  

Event date： 2019.12

Language：Japanese   Presentation type：Poster presentation  

Venue：福岡  

Event date： 2018.11

Language：Japanese   Presentation type：Poster presentation  

Venue：パシフィコ横浜  

Event date： 2018.11

Language：Japanese   Presentation type：Symposium workshop panel(nominated)  

Venue：パシフィコ横浜  

受精から着床までの初期発生の時期はゲノムのエピジェネティックな状態がダイナミックに変化するステージである。配偶子の成熟過程において年齢をはじめとする両親の生理的な条件がゲノムのエピジェネティック修飾に影響を及ぼし、世代を超えて受精後もその影響を残すのかということも重要な問題である。そこで我々はヒト胚盤胞期胚の遺伝子発現を、単一胚ごとにRNA-seqによって解析を行ってきた。その結果多くの遺伝子の発現変動と相関を示したのは母親年齢・父親年齢であった。特に、母親年齢の上昇に従って発現が低下する遺伝子の中に、PTTG1、AURKC、SMC1B、CENPW、MEIKINといった減数分裂時の染色体分配に重要な遺伝子が含まれていることが明らかとなった。このことは、胚盤胞期の遺伝子発現が生殖細胞の成立時期の親の生理的状態の影響をエピジェネティックな調節を介して強く受け、その変化が受精を経て次の世代に伝わる可能性を示唆している。

Audience： General

Type：TV or radio program

Audience： Researchesrs,　Governmental agency

Type：Seminar, workshop