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Hepatoma cells are a promising cell source for the construction of bioartificial liver (BAL) systems owing to their high proliferative capability. However, their low liver function compared with primary hepatocytes is a major problem. In a previous study, we established a genetically modified hepatoma cell line, Hepa/8F5, in which eight liver-enriched transcription factor (LETF) genes were transduced into mouse hepatoma Hepa1-6 cells using a drug-inducible transactivator system. These cells proliferate actively under normal culture conditions, meaning that large quantities can be prepared easily. When the overexpression of the LETFs is induced by the addition of an inducer drug, cell growth stops and cell morphology changes with concomitant high expression of liver functions. However, the liver functions largely depend on the presence of the inducer drug, which must be continuously added to maintain these enhanced functions. In the present study, we attempted to modify the method of induction of LETF overexpression in Hepa/8F5 cells to remove the requirement for continual drug addition. To this end, we constructed a system in which the artificial transactivator was transcribed and amplified under the control of a heat-shock protein promoter, and introduced the system into the genome of Hepa/8F5 cells. In our modified cell line, heat-triggered LETF expression was confirmed to induce high liver function. After drug-screening of transfected cells, we established a hepatoma cell line (Hepa/HS), which exhibited high, heat-inducible liver functions. The Hepa/HS cells may represent a new cell source for hepatic studies such as the construction of BAL systems.

The online version of this article (10.1007/s10616-021-00457-4) contains supplementary material, which is available to authorized users.

The online version of this article (10.1007/s10616-021-00457-4) contains supplementary material, which is available to authorized users.Hyperuricemia, the high uric acid (UA) state in blood, has been accepted as an important risk factor for gout. The liver is a main factory of UA production. In the present study, we have examined the effects of three kinds of flavonol and flavones as typical aglycons, i.e., quercetin, luteolin, apigenin, their glycosides and related compounds, on UA productivity in cultured hepatocytes, adopting allopurinol as the positive control drug. Quercetin, luteolin, diosmetin (4′-O-methylluteolin) and apigenin at 10, 30 and 100 μM as well as allopurinol at 0.1, 0.3 and 1 μM dose-dependently and significantly decreased UA production in the hepatocytes, when compared with 0 μM (control). Both rutin (quercetin-3-O-rutinoside) and quercitrin (quercetin-3-O-ramnoside) significantly reduced UA production in the hepatocytes at 100 μM. Luteolin glycosides such as orientin (luteolin-8-C-glucoside) and isoorientin (luteolin-6-C-glucoside) exerted no influences on it even at 100 μM. Likewise, apigenin glycosides such as vitexin (apigenin-8-C-glucoside) and isovitexin (apigenin-6-C-glucoside) showed no inhibitory effect on it, while apigetrin (apigenin-7-O-glucoside) significantly reduced it at 100 μM. In model mice with purine bodies-induced hyperuricemia, allopurinol completely suppressed the hyperuricemia at a dose of 10 mg/kg body weight. Rutin suppressed significantly the hyperuricemia at a dose of 300 mg/kg body weight, while vitexin showed no significant effect up to 300 mg/kg body weight. Thus, rutin (O-glycoside) is demonstrated to be hypouricemic in both cultured hepatocytes and model mice with recently contrived purine bodies-induced hyperuricemia.We found that strawberry extract suppressed immunoglobulin (Ig) E production in vitro and in vivo, and identified glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as one of the IgE suppressor in the extract. Selleckchem STAT5-IN-1 We report here the effect of GAPDH on various Ig productions in vitro and in vivo. GAPDH suppressed IgE and enhanced IgA, IgG and IgM productions in ovalbumin (OVA)-stimulated human peripheral blood mononuclear cells. Oral administration of GAPDH at 10 mg/kg/day to OVA-induced allergy model mice tended to decrease total IgE level and increase total IgA and IgG levels in sera, and also decreased OVA-specific IgE and IgG levels. It is known that the increase of total IgA as well as the decrease of total and specific IgE is important for alleviating allergic symptoms. In addition, GAPDH accelerated IgA production and increased some cytokine secretions such as IL-4, TGF-β1 and IFN-γ in the OVA-immunized mice spleen lymphocytes. These cytokines involved in the class-switching, IgA enhancement, and IgE suppression, respectively, supporting above results. Our study suggests a possibility that oral administration of GAPDH may induce the immunomodulation in allergic responses.Chinese hamster ovary (CHO) cells are used as host cells for industrial monoclonal antibody (mAb) production. Cell cycle control is an effective approach to increase mAb production in the cell culture. Violacein, a purple-colored pigment produced by microorganisms, has diverse bioactive properties and has been proposed for various industrial applications. In this study, we evaluated the potency of violacein for cell cycle control and improvement of recombinant immunoglobulin G (IgG) production in CHO cells. Compared with the control, 0.9 μM violacein in a 14-day fed-batch culture increased the maximum IgG concentration by 37.6% via increasing the specific production rate and cell longevity. Cell cycle analysis showed that violacein induced G1 and G2/M phase arrest. However, the G1 arrest was observed only on day 1, while G2/M arrest lasted more than 3 days, suggesting that G2/M arrest mediated the violacein-induced enhanced IgG production. Moreover, in line with the increased protein expression, the expression levels of IgG mRNA and nutrient metabolic rates were also increased. N-Linked glycosylation and charge variant profiles were barely affected by violacein treatment. Our results indicate that violacein affects the cell cycle of CHO cells and increases IgG production without changing product quality, showing promise as a mAb production enhancer in CHO cells. The study provides insight into violacein utilization in industrial mAb manufacturing and can help develop advanced, effective mAb production technologies using CHO cell cultures.