A5014201910- Zebrafish Biomedical Research Applications
- Growth Hormone and Insulin-like Growth Factors
- Cancer, Hypoxia, and Metabolism
- Functional Brain Connectivity Studies
- Birth, Development, and Health
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Advanced MRI Techniques and Applications
- Reproductive biology and impacts on aquatic species
- Adipose Tissue and Metabolism
- Sperm and Testicular Function
- Congenital heart defects research
- EEG and Brain-Computer Interfaces
- Animal Genetics and Reproduction
- Physiological and biochemical adaptations
- Lipid metabolism and disorders
- Atomic and Subatomic Physics Research
- MicroRNA in disease regulation
- Liver Disease Diagnosis and Treatment
- Neurological diseases and metabolism
- Diet, Metabolism, and Disease
- Metabolism, Diabetes, and Cancer
- Pancreatic function and diabetes
- Muscle metabolism and nutrition
- Diet and metabolism studies
- Spaceflight effects on biology
Kanazawa University
2017-2025
The University of Tokyo
2003-2021
Graduate School USA
2015
University of Michigan
2007-2013
Michigan United
2008-2009
Saigata National Hospital
2002
Fukuoka University
2002
Hiroshima University
1996
Japan Tobacco (Japan)
1988
Follicle-stimulating hormone (FSH) plays important roles in spermatogenesis. However, the biologic activity of FSH can vary different vertebrate classes, and definitive function has not been established. In this study, we investigated functions on spermatogenesis using an vitro culture system for Japanese eel testis. The Fsh receptor was expressed testis tissue during whole process spermatogenesis, mainly by Leydig cells that produce steroid hormones Sertoli surrounding type A spermatogonia...
Insulin-like growth factors (IGFs) are key regulators of development, growth, and longevity. In most vertebrate species including humans, there is one IGF-1 gene IGF-2 gene. Here we report the identification functional characterization 4 distinct IGF genes (termed as igf-1a, -1b, -2a, -2b) in zebrafish. These encode structurally peptides. IGF-1a IGF-2a mRNAs were detected multiple tissues adult fish. IGF-1b mRNA was only gonad IGF-2b liver. Functional analysis showed that all IGFs caused...
Gene duplication is the primary force of new gene evolution. Deciphering whether a pair duplicated genes has evolved divergent functions often challenging. The zebrafish uniquely positioned to provide insight into process functional evolution due its amenability genetic and experimental manipulation because it possess large number genes.We report identification characterization two hypoxia-inducible in that are co-ortholgs human IGF binding protein-1 (IGFBP-1). IGFBP-1 secreted protein binds...
Animals respond to adverse environments by slowing down or arresting growth and development. Upon returning normal conditions, they often show compensatory acceleration in developmental rate. This phenomenon, known as `catch-up' growth, is widely documented the animal kingdom. The underlying molecular mechanisms, however, are poorly understood. Using zebrafish embryo an experimental model system, we tested hypothesis that changes IGF signaling activities play important role accelerated...
Insulin-like growth factors (IGFs) induce proliferation of various cell types and play important roles in somatic cancer development. Phosphorylation insulin receptor substrate (IRS)-1/2 by IGF-I tyrosine kinase is essential for IGF action. Here we identify Nedd4 as an IRS-2 ubiquitin ligase. monoubiquitinates IRS-2, which promotes its association with Epsin1, a ubiquitin-binding protein. recruits to the membrane, probably through promoting Epsin1 binding, enhances receptor-induced...
Background Insulin-like growth factor binding protein-2 (IGFBP-2) is a secreted protein that binds and regulates IGF actions in controlling growth, development, reproduction, aging. Elevated expression of IGFBP-2 often associated with progression many types cancers. Methodology/Principal Findings We report the identification characterization two genes zebrafish four other teleost fish. Comparative genomics structural analyses suggest they are co-orthologs human gene. Biochemical assays show...
Among vertebrates, teleost fishes have evolved the most impressive adaptations to variable oxygen tensions in water (Shoubridge and Hochachka 1980; Nilsson Randall 2010). Under conditions of deprivation (hypoxia), major changes gene expression are mediated by hypoxia-inducible factors (HIF alpha). Here we show that hif alpha genes were duplicated specific whole-genome duplication. Although one each paralogous pair was lost teleosts, both copies retained cyprinids. Computational analyses...
Insulin-like growth factor binding protein (IGFBP)-5 is a secreted that binds to IGF and modulates actions. IGFBP-5 also found in the nucleus of mammalian cells has transactivation activity. The structural basis this activity its role mediating IGF-independent actions are not clear. Here we report there 2 igfbp-5 genes zebrafish other teleost fish. In zebrafish, igfbp-5a -5b expressed spatially restricted, mostly nonoverlapping domains during early development. site conserved both IGFBP-5s,...
A new functional magnetic resonance imaging (fMRI) technique to visualize the distribution of neuronal currents in human brain was developed Measurements internal field deformation caused by an electric current dipole a phantom were performed using method based on microscopic technique. The minimal value moment detected present determined be 90 nAm. applied obtain maps activity motor and sensory stimulus paradigms. made with EPI sequence at 1.5 T. Intensity changes, resulting from causes...
Abstract We previously reported that a low-protein diet caused animals to develop fatty liver containing high level of triglycerides (TG), similar the human nutritional disorder “kwashiorkor”. To investigate underlying mechanisms, we cultured hepatocytes in amino acid-sufficient or deficient medium. Surprisingly, intracellular TG was increased by acid deficiency without addition any lipids hormones, accompanied enhanced lipid synthesis, indicating themselves monitored extracellular...
Insulin receptor substrates (IRSs) are well-known mediators of the insulin and insulin-like growth factor (IGF)-I signaling pathways. We previously reported that protein levels IRS-2, a molecular species IRS, were upregulated in livers rats fed protein-restricted diet. This study aimed to elucidate physiological role whose level increases response restriction cultured hepatocyte models. Hepatocyte-derived cell lines subjected amino acid deprivation showed increased IRS2 mRNA IRS-2 due...
Fetal growth restriction is often caused by uteroplacental insufficiency that leads to fetal hypoxia and nutrient deprivation. Elevated IGF binding protein (IGFBP)-1 expression associated with has been documented. In this study we tested the hypothesis deprivation induce IGFBP-1 phosphorylation increase its biological potency in inhibiting actions. HepG2 cells were subjected leucine mimic of metabolic substrates. The total levels measured ELISA approximately 2- 2.5-fold higher...
This study demonstrates inducible transgenic expression in the exceptionally short‐lived turquoise killifish Nothobranchius furzeri , which is a useful vertebrate model for ageing research. Transgenic N. bearing green fluorescent protein (Gfp) containing construct under control of heat shock 70 promoter were generated, shock‐induced and reversible Gfp was demonstrated germline transmission transgene to F1 F2 generations achieved. The availability this system will make ageing‐related...
Although fasting induces hepatic triglyceride (TG) accumulation in both rodents and humans, little is known about the underlying mechanism. Because parasympathetic nervous system activity tends to attenuate secretion of very-low-density-lipoprotein-triglyceride (VLDL-TG) increase TG stores liver, serum cholinesterase elevated fatty liver disease, inhibition neurotransmitter acetylcholinesterase (AChE) may have some influence on lipid metabolism. To assess AChE metabolism, effect...
Most animals display retarded growth in adverse conditions; however, upon the removal of unfavorable factors, they often show quick restoration, which is known as "catch-up" growth. In zebrafish embryos, hypoxia causes arrest, but subsequent reoxygenation induces catch-up Here, we report role insulin receptor substrate (Irs)1–mediated insulin/insulinlike factor signaling (IIS) and involvement stem cells reoxygenated embryos. Disturbed irs1 expression attenuated IIS, resulting greater...
Congenital loss of the SHOX gene is considered to be a genetic cause short stature phenotype in Turner syndrome and Leri-Weill dyschondrosteosis patients. Though expression initiates during early fetal development, little known about embryonic roles SHOX. The evolutionary conservation zebrafish shox convenience developmental stages for analyses make preferred model. Here, we characterized structure, expression, through loss-of-function approach.We found previously undiscovered Shox protein...
ABSTRACT In order to efficiently derive hematopoietic stem cells (HSCs) from pluripotent precursors, it is crucial understand how mesodermal acquire and endothelial identities: two divergent, but closely related, cell fates. Although Npas4 has been recently identified as a conserved master regulator of hemato-vascular development, the molecular mechanisms underlying fate divergence between vascular are still unclear. Here, we show in zebrafish that differentiation into regulated by...
The authors describe a patient who had point mutation at codon 232 of the prion protein gene, resulting in substitution methionine for arginine (M232R). developed dementia and died 6 years after its onset. Autopsy revealed with Lewy bodies, not Creutzfeldt–Jakob disease. Although M232R has been reported to cause disease, findings our suggest that all patients presenting progressive have