記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Scientific Reports  

HepG2 cells are widely used as a human hepatocytes model, but their functions, including drug metabolism, are inferior to primary hepatocytes. We previously reported that the hepatic gene expressions in HepG2 cells were upregulated by treatment with zebularine, which is an inhibitor of DNA methylation, through the inhibition of both DNA methyltransferase 1 (DNMT1) and double-stranded RNA-dependent protein kinase (PKR). In this study, we established a new HepG2 cell subline, HepG2-DP cells, by stable double knockdown of DNMT1 and PKR and evaluated its function. Albumin production, expression of CYP1A2 genes, and accumulation of lipid droplets were increased in HepG2-DP cells compared with the original HepG2 cells. Comprehensive gene expression analysis of transcription factors revealed that the expression of important genes for hepatic function, such as HNF1β, HNF4α, ONECUT1, FOXA1, FOXA2, FOXA3, and various nuclear receptors, was upregulated in HepG2-DP cells. These results indicate that the newly established HepG2-DP cells are a highly functional hepatocyte cell line. In addition, we investigated whether HepG2-DP cells are able to mature by differentiation induction, since HepG2 cells are derived from hepatoblastoma. The gene expression of major CYPs and Phase II, III drug-metabolizing enzyme genes was significantly increased in HepG2-DP cells cultured in differentiation induction medium. These results suggest that HepG2-DP cells can be further matured by the induction of differentiation and could therefore be applied to studies of drug metabolism and pharmacokinetics.

DOI： 10.1038/s41598-022-25777-z

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その他リンク： https://www.nature.com/articles/s41598-022-25777-z

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Biology of the Cell  

Background Information: An in vitro evaluation system using cultured hepatocytes is the most useful method in preclinical research, such as drug metabolism and toxicity test. Human hepatocytes should be used in an in vitro evaluation system because the expression of drug-metabolizing enzymes varies among animal species. HepG2 cells, a liver cancer-derived cell line, are widely used as a human hepatocyte model; however, their hepatic functions are generally weak. Results: In this study, we showed that low-density HepG2 cell culture induces hepatic function. The morphology of HepG2 cells was altered depending on the cell density at the time of seeding. Low-density cultured HepG2 cells proliferated as tightly packed colonies. The HepG2 cell colonies in low-density culture demonstrated enhanced tight junction formation. Tight junction protein gene expression levels, such as those of zonula occludens-1 (ZO-1), junctional adhesion molecule 1 (JAM), claudin, occludin, and tricellulin, increased in low-density cultured HepG2 cells. Phases I and II metabolic enzymes, phase III transporter gene expression, and CYP3A4 activity also increased in low-density cultured HepG2 cells. Occludin and tricellulin knockdown inhibited the increased hepatic function in low-density cultures. Tricellulin knockdown reduced the expression of hepatocyte nuclear factor 6 (HNF6), CCAAT/enhancer-binding protein alpha (CEBPA), and aryl hydrocarbon receptor (AHR). In addition, the expression of nuclear receptor subfamily 1 group h member 2 (NR1H2) increased in low-density cultures, canceled by occludin and tricellulin knockdown. Conclusions: Our results suggest that low-density HepG2 cell cultures enhance hepatic function by promoting tight junction formation and demonstrate the importance of cell density in drug evaluation using hepatocyte cell lines.

DOI： 10.1111/boc.202200002

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PubMed

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Neuroscience Research  

We previously reported that mice pups showed individual differences in mother preferences at 16 days old; some pups show high preference to their mother, and other pups show low preference to it. In this study, we examined whether these individual differences were associated with anxiety-like behavior and cognition functions in adulthood. We found that pups showing low mother preference exhibit low anxiety-like behavior and impaired object cognition in adulthood. These results suggest that some behavioral characteristics in adulthood may be associated with the profile of mother preference prior to weaning.

DOI： 10.1016/j.neures.2022.06.004

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Neuroscience Research  

Mutual attachment between mother and pup is important to enable the mother to care for her pup and for the pup to receive care from its mother. Pups eventually leave their mothers, which is also very important to their growth. The mechanism of preference by which pups transfer attachment from their mother to others remains unknown. In this study, we assessed mother/novel dam preferences and examined the brain regions associated with the regulation of this preference in C57BL/6 mice pups. We found that C57BL/6 mice pups had variety in their mother/novel dam preferences at 16 days old. This variety was not related to the sex of the pups, their weight, or the litter size. In order to clarify the brain mechanisms responsible for this variety, we examined the relationship between mother/novel dam preference and neuronal activation induced by contact with the mother. We found that pups exhibiting novel dam preference had higher neural activity in the anterior cingulate cortex (ACC) and bed nucleus of the stria terminalis (BNST) when exposed to their mother. These results suggest that ACC and/or BNST neural activity may be associated with mother/novel dam preferences in infant mice.

DOI： 10.1016/j.neures.2022.01.008

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PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Physiology and Behavior  

Although the involvement of two types of vasopressin (AVP) receptors, v1a and v1b, in neural regulation of social behavior is well documented in rodents, there is no report on combined actions of them in regulation of social behavior. In this study, we investigated behavioral differences between wild-type (WT) and v1a and v1b double knockout (dKO) mice. For this, we measured olfactory preference, sexual behavior with receptive females (four weekly tests) in an enriched large observation cage, and anxiety-like behaviors. No difference between WT and dKO mice was found in olfactory preferences for estrous female odor to male odor. Over all four mating tests, the number of mounts and pursuits after receptive females was significantly greater in dKO mice than in WT mice. In the elevated plus maze and the open field test, dKO mice showed lower anxiety-like behavior than WT mice. Finally, we measured approach behavior to several types of objects, figurines, and caged anestrous or estrous females placed in the open field apparatus. The only difference observed was that dKO mice spent longer in the vicinity of estrous females than did WT mice. These findings suggest that vasopressin receptors are involved in the regulation of sociosexual behavior, presumably partly mediated by emotional responses, in male mice.

DOI： 10.1016/j.physbeh.2018.09.016

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PubMed

記述言語：日本語   出版者・発行元：(一社)日本内分泌学会  

記述言語：日本語   出版者・発行元：日本動物心理学会