• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.33-37
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• 2012

Differential capacity of the parthenogenetic embryonic stem cells (PESCs) is still under controversy and the mechanisms of its neural induction are yet poorly understood. Here we demonstrated neural lineage induction of PESCs by addition of insulin-like growth factor-2 (Igf2), which is an important factor for embryo organ development and a paternally expressed imprinting gene. Murine PESCs were aggregated to embryoid bodies (EBs) by suspension culture under the leukemia inhibitory factor-free condition for 4 days. To test the effect of exogenous Igf2, 30 ng/ml of Igf2 was supplemented to EBs induction medium. Then neural induction was carried out with serum-free medium containing insulin, transferrin, selenium, and fibronectin complex (ITSFn) for 12 days. Normal murine embryonic stem cells derived from fertilized embryos (ESCs) were used as the control group. Neural potential of differentiated PESCs and ESCs were analyzed by immunofluorescent labeling and real-time PCR assay (Nestin, neural progenitor marker; Tuj1, neuronal cell marker; GFAP, glial cell marker). The differentiated cells from both ESC and PESC showed heterogeneous population of Nestin, Tuj1, and GFAP positive cells. In terms of the level of gene expression, PESC showed 4 times higher level of GFAP expression than ESCs. After exposure to Igf2, the expression level of GFAP decreased both in derivatives of PESCs and ESCs. Interestingly, the expression level of $Tuj1$ increased only in ESCs, not in PESCs. The results show that IGF2 is a positive effector for suppressing over-expressed glial differentiation during neural induction of PESCs and for promoting neuronal differentiation of ESCs, while exogenous Igf2 could not accelerate the neuronal differentiation of PESCs. Although exogenous Igf2 promotes neuronal differentiation of normal ESCs, expression of endogenous $Igf2$ may be critical for initiating neuronal differentiation of pluripotent stem cells. The findings may contribute to understanding of the relationship between imprinting mechanism and neural differentiation and its application to neural tissue repair in the future.

• Journal of Life Science
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• v.27 no.7
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• pp.834-839
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• 2017

Propolis is a natural product collected from plants by honey bees product used extensively in traditional medicine for its antioxidant, anti-inflammatory, immunomodulatory and anti-cancer effects. Propolis exhibits a broad spectrum of biological activities because it is a complex mixture of natural substances. Ovarian cancer is the second most common newly diagnosed cancer from all cancers among women in Korea and the leading cause of death from gynecological malignancies. While most ovarian cancer patients initially respond to surgical debulking and chemotherapy, patients later succumb to the disease. Thus, there is an urgent need to test novel therapeutic agents to counteract the high mortality rate associated with ovarian cancer. In this study, we investigated the anti-cancer properties and the active mechanism of Australian propolis in human epithelial ovarian cancer A2780 cells. Our data revealed that propolis showed a cytotoxic activity in a dose-dependent manner. Flow cytometric analysis for cell cycle arrest and apoptosis using propidium iodide staning and annexin V-FITC indicated that propolis could induce cycle arrest in the G0/G1 phase and apoptosis in a dose-dependent manner on human epithelial ovarian cancer cells. These results suggest that the Australian propolis is potential alternative agent on ovarian cancer prevention and treatment.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.219-236
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• 2005

Glycolic acid, an alpha-hydroxy acid derived from fruit and milk sugars, has been commonly used as a cosmetic ingredient since it was known to have photo-protective, anti-inflammatory effects, and anti-oxidant effect in UV-irradiated skin. However, little has been know about the functional role of glycolic acid on UV-induced skin cell proliferation. It was previously found that glycolic acid inhibited UV-induced skin tumor development in hairless mouse. As a possible mechanism of glycolic acid on the UV-induced skin tumor development, the ability of glycolic acid to inhibit the UVB-induced cell growth and possible mechanisms were investigated. Glycolic acid treatment attenuated the UV-induced cell proliferation and apoptotic cell death in the skin. In vitro study, glycolic acid inhibited the UVB-induced cell growth and apoptotic death through inhibiting caspase-3 activity. These results suggest that glycolic acid may exert the Inhibitory effect on the UVB-induced skin tumor development by regulating cell growth and apoptotic cell death.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.2
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• pp.103-114
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• 2017

Gnaphalium affine D. DON (GA) has been used as a vegetable as well as a folk medicine in East Asia. The antioxidant and anti-complementary activity of GA extract (GAE) has also been reported. However, little is known about its anti-inflammatory and anti-allergic effect and mechanism of action. In this study, we evaluated the inhibitory effects of GAE on the production of inflammatory mediators such as NO, $PGE_2$, TLR4, eotaxin-1 and histamine. Our results suggest that GAE inhibits the production of NO and $PGE_2$ by inhibiting transcriptional activation via the involvement of iNOS and COX-2. The LPS-induced expression of Toll-like receptor 4 (TLR4) was also attenuated. In addition, GAE inhibited A23187-induced histamine release from MC/9 mast cells. It also inhibited the production of eotaxin-1 induced by IL-4. Collectively, these results suggest that GAE may have considerable potential as a cosmetic ingredient with anti-inflammatory and anti-allergic properties.

• Journal of Plant Biology
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• v.38 no.1
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• pp.87-93
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• 1995

For understanding physiological nature of phototaxis in Synechocystis sp. PCC 6803 PTX(S. 6803 PTX), we examined the effects of some metabolic inhibitors and cation ionophore on the phototactic movement. In the presence of DCMU, which blocks the photosynthetic electron transport just after photosystem II acceptor, there was no inhibitory effect on the phototaxis up to $100\;\mu\textrm{M}$. Instead, the respiratory electron chain inhibitor such as sodium azide dramatically impaired the phototaxis in S. 6803 PTX. These observations indicate that the phototaxis is linked not to photo-phosphorylation, but to respiratory phosphorylation. When the cells were treated with un couplers such as CCCP or DNP, which dissipate the electrochemical gradient of proton($\Delta\mu_{H}+$) across the cytoplasmic membrane, these chemicals did not affect phototaxis. In contrast, when cells were treated with DCCD or NBD which deprive cells of A TP but leave $\Delta\mu_{H}+$ intact across the membrane, the phototactic movement was severly reduced. These results imply that ATP production, not proton motive force, is involved in the phototactic movement in this organism as a driving motive force. The application of specific calcium ionophore A23187 strongly impaired positive phototaxis. Calcium fluxes should be engaged in the sensory trans-duction of phototactic orientation. Finally, when ethionine was supplimented to culture media, the photomovement of this organism was inhibited. This implies that methylation/demethylation mechanism controls the process of phototaxis in S. 6803 PTX like chemotaxis in E. coli and Salmonella typhimurium.murium.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.305-310
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• 2005

It has been suggested that nitric oxide (NO) derived from inducible nitric oxide synthase (iNOS) may act as a mediator of cytokine-induced effects on bone turn-over. NO is also recognized as an important factor in bone remodeling, i.e., participating in osteoblast apoptosis in an arthritic joint. The components of Agastache rugosa are known to have many pharmacological activities. In the present study, we investigated the effects of Agastache rugosa leaf extract (ELAR) on NO production and the iNOS expression in ROS 17/2.8 cells activated by a mixture of inflammatory cytokines including TNF-$alpha$ and IL-1$\beta$. A preincubation with ELAR significantly and concentration-dependently reduced the expression of iNOS protein in ROS 17/2.8 cells activated with the cytokine mixture. Consequently, the NO production was also significantly reduced by ELAR with an IC$_{50}$ of 0.75 mg/mL. The inhibitory mechanism of iNOS induction by ELAR prevented the activation and translocation of NF-$\kappa$B (p65) to the nucleus from the cytosol fraction. Furthermore, ELAR concentration-dependently reduced the cellular toxicity induced by sodium nitroprusside, an NO-donor. These results suggest that ELAR may be beneficial in NO-mediated inflammatory conditions such as osteoporosis.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.485-490
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• 1999

The mechanism of action of fish oil (FO), currently used in different chronic inflammatory conditions such as rheumatoid arthritis (RA), is not completely understood, although it is thought that it could alter the metabolism of endogenous autacoids. In addition, we hypothesized that the known capability of fatty acids (FA) of stabilizing serum albumin and perhaps other proteins, may be of pharmacological relevance considering that it is shared by other anti-rheumatic agents (e.g. nonsteroidal antiinflammatory drugs). Thus, we studied the effect of oral administration of FO and corn oil (CO), a vegetable oil with a different composition, on the stability of rat serum proteins, evaluated buy a classical in vitro method based on heat-induced protein denaturation. FO, and, to a lower extent, CO inhibited heat-induced denaturation of rat serum (RS): based on the inhibitory activity (EC50) of the major fatty acids against heat-induced denaturation of RS in vitro, it was possible to speculate the in vivo effects of palmitic acid (C16:0) and eicosapentaenoic acid (EPA, C20:5, n-3) may be more relevant than that of linolenic acid (C18:2). To better investigate this phenomenon, we extracted albumin from the serum of animals treated or not with FO with a one-step affinity chromatography technique, obtaining high purity rat serum albumin preparations (RSA-CTRL and RSA-FO), as judged by SDS-PAGE with Coomassie blue staining. When these RSA preparations were heated at $70^{\circ}C$ for 30 min, it was noted that RSA-FO was much more stable than RSA-CTRL, presumably due to higher number of long chain fatty acids (FA) such as palmitic acid or EPA. In conclusion, we provided evidences that oral administration of FO in the rat stabilizes serum albumin, due to an increase in the number of protein bound long chain fatty acids (e.g. palitic acid and EPA). We speculate that the stabilization of serum albumin and perhaps other proteins could prevent changes of antigenicity due to protein denaturation and glycosylation, which may trigger pathological autoimmune responses, suggesting that this action may be involved in the mode of action of FO in RA and other chronic inflammatory diseases.

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.127-133
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• 2020

Chibby family member 2 (CBY2), also known as SPERT or NURIT, is a gene with Chibby-like super family domain, whose function is not well known. In this study, the quail CBY2 gene was cloned, its sequences were analyzed, and its role in the myogenesis of QM7 quail muscle cells was characterized. Quail CBY2 has 978 nucleotides, which are translated into 325 amino acids, and the amino acid sequences are highly similar to those of chicken CBY2. Avian CBY2 diverted from mammalian CBY2 during early evolutionary history. According to the protein domain prediction analysis, quail CBY2 has a Chibby-like superfamily domain consisting of 83 amino acids at the N-terminal of the protein, although compared to mammalian CBY2, many of the amino acids were different. CBY2 was highly expressed in the adipose tissue and moderately expressed in the liver, heart, and kidney, whereas rarely expressed in the muscle tissue in quail. To characterize the role of CBY2 in myogenesis, CBY2 was overexpressed in QM7 cells. The overexpression of CBY2 inhibited myotube formation as shown that the myotube area was approximately only 25% that of the control. Taken together, quail CBY2 has a Chibby-like superfamily domain and inhibits myogenesis. Further studies should focus on the identification of the inhibitory mechanism of CBY2 on myogenesis.

• Journal of Life Science
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• v.18 no.1
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• pp.114-119
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• 2008

The molecular machinery controlling cell cycle is centered around the regulation of the activity of maturation-promoting factor (MPF), a complex composed of a catalytic Cdc2 and the cyclinB regulatory subunit. Cdc2 kinase is inactivated by phosphorylation of inhibitory kinase, Wee1. It has been known that there are three different Wee1 kinases in the mammalian cell, Wee1A, Wee1B and Myt1. To investigate the regulatory mechanism of Wee1 kinases, the phosphorylation and degradation of Wee1A and Wee1B were checked in the Xenopus oocyte cell cycle. When Wee1 kinases were injected into frog oocyte, Wee1B was more stable than Wee1A. Wee1A and Wee1B kinase were phosphorylated by many kinases such as PKA and Akt. The roles of amino or carboxyl terminal in mouse Wee1A or Wee1B kinase were investigated using chimeric constructs. The degree of protein phosphorylation, degradation and cell cycle progression were different between chimeric constructs. The amino domain of Wee1A was implicated in the protein phosphorylation and degradation while amino domain of Wee1B and carboxyl domain of Wee1A were involved in the activity regulation. These results suggested that the domains of Wee1 kinase have different and significant roles in regulating the Wee1 kinases in the cell cycle progression.

• Journal of Life Science
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• v.23 no.3
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• pp.333-340
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• 2013

This study was performed to determine whether stem bark extract containing saponin of Albizzia julibrissin in the diet influences gonadal maturation and spawning in medaka (Oryzias latipes). The crude extraction containing saponin (HaBC) was partially purified from n-BuOH extraction of A. julibrissin stem bark by Diaion HP-20, Silica gel and Sephadex LH-20 chromatographies. We fed diets supplemented with HaBC to medaka. We then studied the effects of the HaBC supplement on the suppression of gonadal maturation and spawning in female medaka that were reared in aquaria with recirculation systems. In the experiment with immature female medaka, the periods of initiation of gonadal maturation and spawning were delayed in the fish that were fed diets supplemented with at least HaBC 20 mg/g-feed. In the experiment with mature female medaka, the fish that were fed diets supplemented with at least HaBC 20 mg/g-feed had lower GSIs than the control diet group did. The results showed that the growth of the immature medaka was not correlated with the amount of supplementation of HaBC in the diet. However, the condition factors (CF) in the medaka that were fed diets supplemented with at least HaBC 20 mg/g-feed were higher than in the medaka fed on the control diet. We concluded that extracts containing saponin from the stem bark of A. julibrissin have the potential to inhibit gonadal maturation in female medaka, but they did not act as growth stimulation. Further studies are required to determine the mechanism of the action.