Publications by authors named "Hiroko Nansai"

Article Synopsis
  • Low-dose radiation has significant effects on undifferentiated cells but its specific impacts on developing retinal cells are not fully understood.
  • This study examined human retinal cells created from induced pluripotent stem cells (iPSCs) after exposure to low-dose radiation, discovering that different radiation levels (30 vs. 180 mGy) influenced gene expression and cellular development distinctly.
  • Results indicated that while 30 mGy promoted the growth of essential eye development factors and certain retinal cells, 180 mGy led to decreased levels and suggested a dedifferentiation and neural development response, indicating that developing retinal cells adapt through complex biological mechanisms under stress conditions.
View Article and Find Full Text PDF
Article Synopsis
  • Chemical-induced changes in DNA methylation during fetal development can lead to disorders or increased disease risk later in life.
  • The study created a detection assay using human iPS cells with a fluorescent marker to screen for harmful chemicals that affect DNA methylation.
  • Analysis of 135 chemicals revealed that those with stronger MBD signals were linked to significant impacts on DNA methylation and gene expression related to cell growth and development, showcasing the assay's potential for advancing drug safety and research.
View Article and Find Full Text PDF

Increasing evidence indicates that many insecticides produce significant epigenetic changes during embryogenesis, leading to developmental toxicities. However, the effects of insecticides on DNA methylation status during early development have not been well studied. We developed a novel nuclear phenotypic approach using mouse embryonic stem cells harboring enhanced green fluorescent protein fused with methyl CpG-binding protein to evaluate global DNA methylation changes via high-content imaging analysis.

View Article and Find Full Text PDF

Stress in early life has been linked with the development of late-life neurological disorders. Early developmental age is potentially sensitive to several environmental chemicals such as alcohol, drugs, food contaminants, or air pollutants. The recent advances using three-dimensional neural sphere cultures derived from pluripotent stem cells have provided insights into the etiology of neurological diseases and new therapeutic strategies for assessing chemical safety.

View Article and Find Full Text PDF

The practical application of engineered nanomaterials or nanoparticles like polyamidoamine (PAMAM) dendrimers has been promoted in medical devices or industrial uses. The safety of PAMAM dendrimers needs to be assessed when used as a drug carrier to treat brain disease. However, the effects of PAMAM on the human nervous system remain unknown.

View Article and Find Full Text PDF

The effects of chronic low-dose radiation on human health have not been well established. Recent studies have revealed that neural progenitor cells are present not only in the fetal brain but also in the adult brain. Since immature cells are generally more radiosensitive, here we investigated the effects of chronic low-dose radiation on cultured human neural progenitor cells (hNPCs) derived from embryonic stem cells.

View Article and Find Full Text PDF

Di-(2-ethylhexyl)-phthalate (DEHP) is a phthalate ester that binds peroxisome proliferator-activated receptor α (PPARα) to induce proliferation of peroxisomes and regulate the expression of specific target genes. The question of whether the effect of DEHP on female reproductive processes is mediated via PPARα-dependent signaling is controversial. In this study, we investigated the effect of exposure to DEHP on ovarian expression of estrogen receptor α (Esr1) and aromatase (Cyp19a1) in three generations of Sv/129 wild-type (WT, +/+) and PPARα (-/-) knockout mice.

View Article and Find Full Text PDF