Yu Takahashi 교수

Gut epithelial organoids are routinely used to investigate intestinal biology; however, current culture methods are not amenable to genetic manipulation, and it is difficult to generate sufficient numbers for high-throughput studies. Here, we present an improved culture system of human induced pluripotent stem cell (iPSC)-derived intestinal organoids involving four methodological advances. (1) We adopted a lentiviral vector to readily establish and optimize conditioned medium for human intestina

3D (three-dimensional) cultures are considered to be an effective method for toxicological studies; however, little evidence has been reported whether 3D cultures have an impact on hepatocellular physiology regarding lipid or glucose metabolism. In the present study, we conducted physiological characterization of hepatoma cell lines HepG2 and HepaRG cells cultured in 3D conditions using a hanging drop method to verify the effect of culture environment on cellular responses. Apo (Apolipoprotein)B

In the course of an effort to identify the regulators for peroxisome proliferator-activated receptor gamma (PPARgamma)-dependent perilipin gene expression, we found that tribbles homolog 3 (TRB3), containing a single kinase domain without enzymatic activity, downregulates PPARgamma transcriptional activities by protein-protein interaction. We examined the role that TRB3 plays in adipocyte differentiation in 3T3-L1 cells. TRB3 gene and protein expression was increased during adipocyte differentia

Perilipin2 (Plin2), also known as adipose differentiation-related protein (ADRP), or adipophilin, is a member of the PAT family involved in lipid droplet (LD) formation in the liver and peripheral tissues. Although Plin2 was originally identified as a highly expressed gene in adipocytes, its physiological role in mature adipocytes is largely unknown. In this report, we investigated the regulation of Plin2 expression and its function in differentiated adipocytes of mouse embryonic fibroblasts (ME

Elaborate metamerism in vertebrate somitogenesis is based on segmental gene expression in the anterior presomitic mesoderm (PSM). Notch signal pathways with Notch ligands Dll1 and Dll3, and the transcription factor Mesp2 are implicated in the rostrocaudal patterning of the somite. We have previously shown that changes in the Mesp2 expression domain from a presumptive one somite into a rostral half somite results in differential activation of two types of Notch pathways, dependent or independent

Sterol regulatory element-binding protein-1 (SREBP-1) has been thought to be a critical factor that assists adipogenesis. During adipogenesis SREBP-1 stimulates lipogenic gene expression, and peroxisome proliferator-activated receptor γ (PPARγ) enhances perilipin (plin) gene expression, resulting in generating lipid droplets (LDs) to store triacylglycerol (TAG) in adipocytes. Plin coats adipocyte LDs and protects them from lipolysis. Here we show in white adipose tissue (WAT) of plin-/- mice tha

Visceral fat accumulation as observed in Crohn's disease and obesity is linked to chronic gut inflammation, suggesting that accumulation of gut adipocytes can trigger local inflammatory signaling. However, direct interactions between intestinal epithelial cells (IECs) and adipocytes have not been investigated, in part because IEC physiology is difficult to replicate in culture. In this study, we originally prepared intact, polarized, and cytokine responsive IEC monolayers from primary or induced

SUMO/Smt3, a ubiquitin-like modifier, is known to conjugate other proteins and modulate their functions in various processes. Recently, Ull1/Siz1 was discovered as a novel PIAS-type E3 required for septin sumoylation in yeast. We demonstrate here that the second PIAS-type Nfi1/Siz2 is also a SUMO ligase. It interacted with Smt3, SUMO/Smt3 conjugating enzyme Ubc9 and a septin component Cdc3 in the two-hybrid system. The region containing the RING-like domain of Nfi1/Siz2 bound directly to Ubc9 an

Our results indicate that LAT1, but not LAT2, recognizes pregabalin as a substrate. It is suggested that LAT1 mediates pregabalin transport at the BBB.

Mesp1 and Mesp2 are homologous basic helix-loop-helix (bHLH) transcription factors that are co-expressed in the anterior presomitic mesoderm (PSM) just prior to somite formation. Analysis of possible functional redundancy of Mesp1 and Mesp2 has been prevented by the early developmental arrest of Mesp1/Mesp2 double-null embryos. Here we performed chimera analysis, using either Mesp2-null cells or Mesp1/Mesp2 double-null cells, to clarify (1) possible functional redundancy and the relative contrib

Intestinal organoids are physiologically relevant tools used for cellular models. However, the suitability of organoids to examine biological functions over existing established cell lines lacks sufficient evidence. Cytochrome P450 3A4 (CYP3A4) induction by pregnane X receptor ligands, glucose uptake via sodium/glucose cotransporter 1, and microsomal triglyceride transfer protein-dependent ApoB-48 secretion, which are critical for human intestinal metabolism, were observed in organoid-derived tw

Organoids are regarded as physiologically relevant cell models and useful for compound screening for drug development; however, their applications are currently limited because of the high cost of their culture. We previously succeeded in reducing the cost of human intestinal organoid culture using conditioned medium (CM) of L cells co-expressing Wnt3a, R-spondin1, and Noggin. Here, we further reduced the cost by replacing recombinant hepatocyte growth factor with CM. Moreover, we showed that em

Spin-orbit torque-induced switching of an elliptical nanomagnet with an in-plane easy axis allows sub-ns and field-free operation. Since its properties crucially depend on the design of the nanomagnet such as the easy-axis direction, it is of high importance to systematically elucidate the dependence of performance on various parameters of the nanomagnet towards magnetoresistive random access memory applications. Here, we show a scheme to statistically evaluate the switching properties of in-pla