• Asian-Australasian Journal of Animal Sciences
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• 제33권6호
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• pp.1012-1022
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• 2020

Objective: Caseins and fatty acids of milk are synthesized and secreted by the epithelial cells of the mammary gland. All-trans retinoic acid (ATRA), an active metabolite of vitamin A, has been shown to promote mammary development. This study was conducted to determine the effect of ATRA on casein synthesis and fatty acid composition in MAC-T cells. Methods: MAC-T cells were allowed to differentiate for 4 d, treated with ATRA (0, 1.0, 1.5, and 2.0 μM), and incubated for 3 d. We analyzed the fatty acid composition, the mRNA expression of casein and fatty acid synthesis-related genes, and the phosphorylation of casein synthesis-related proteins of MAC-T cells by gas chromatography, quantitative polymerase chain reaction, and western blotting, respectively. Results: In MAC-T cells, ATRA increased the mRNA levels of α_S1-casein and β-casein, janus kinase 2 (JAK2) and E74-like factor 5 of the signal transducer and activator of transcription 5 β (STAT5-β) pathway, ribosomal protein S6 kinase beta-1 (S6K1) and eukaryotic translation initiation factor 4E binding protein 1 of the mammalian target of rapamycin (mTOR) pathway, inhibited the mRNA expression of phosphoinositide 3-kinase and eukaryotic initiation factor 4E of the mTOR pathway, and promoted the phosphorylation of STAT5-β and S6K1 proteins. Additionally, ATRA increased the de novo synthesis of fatty acids, reduced the content of long-chain fatty acids, the ratio of monounsaturated fatty acids to saturated fatty acids (SFA), the ratio of polyunsaturated fatty acids (PUFA) to SFA, and the ratio of ω-6 to ω-3 PUFA. The mRNA levels of acetyl-CoA carboxylase 1, fatty acid synthase, lipoprotein lipase, stearoyl-CoA desaturase, peroxisome proliferator-activated receptor gamma, and sterol regulatory element-binding protein 1 (SREBP1) were enhanced by ATRA. Conclusion: ATRA promotes the synthesis of casein by regulating JAK2/STAT5 pathway and downstream mTOR signaling pathway, and it improves the fatty acid composition of MAC-T cells by regulating SREBP1-related genes.

• Korean Journal of Acupuncture
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• 제37권2호
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• pp.63-75
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• 2020

Objectives : Osteoporosis is the most common bone disease and osteoporosis fracture is the leading cause of decreased life. Bisphosphonate and selective estrogen receptor modulators are the best choice of treatment for osteoporosis. However, when used for a long time, they increase the probability of side effect such as osteonecrosis of the jaw. Thus, it is crucial to develop alternative medicine to treat osteoporosis. Gentianae Macrophyllae Radix, a herbal medicine, is mainly to treat rheumatoid arthritis. However, the effect of the water extract of Gentianae Macrophyllae Radix (w-GM) on osteoporosis has not been investigated. Thus, we examine whether w-GM can inhibit osteoclast differentiation and bone resorption on receptor activator of nuclear factor kappa-B (NF-κB) ligand (RANKL)-treated RAW 264.7 cells. In this study, RAW 264.7 cells were used as an osteoclast differentiation model by treating them with RANKL. Methods : RAW 264.7 cells were used to determine the effect of w-GM on osteoclast differentiation and bone resorption. The number of tartrate-resistant acid phosphatase (TRAP)-positive cells, TRAP activity and pit formation assay were examined. In addition, protein expressions were measured by western blot and mRNA expressions were analyzed by reverse transcription polymerase chain reaction. Results : Treatment with w-GM inhibited the number of TRAP-positive cells, TRAP activity and pit area. In addition, w-GM decreased protein expression such as mitogen-activated protein kinase, NF-κB, c-Fos and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1). It also inhibited the mRNA levels such as c-Fos, NFATc1, TRAP, NF-κB, calcitonin receptor and cathepsin K in RANKL-treated RAW 264.7 cells. Conclusions : These results suggest that w-GM has inhibitory effects via osteoclast differentiation, thus it could be a new medication for osteoporosis.

• Journal of Ginseng Research
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• 제32권1호
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• pp.39-47
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• 2008

본 실험은 홍삼 혼합물 (KTNG0345)을 이용한 주름 예방 및 개선효과가 있는 건강기능 식품을 개발하기 위한 기초자료로 활용하기 위하여 시료를 경구투여한 무모생쥐의 피부조직 으로부터 MMP-3의 발현양상과 작용 메커니즘을 연구하였다. MMP-3의 발현정도는 농도 의존적으로 현저한 감소를 나타내었으며, 유전자와 단백질 모두에서 동일한 양상을 보였다. PAK는 변화가 없었지만, p38, p-p38 그리고 c-Jun, p-c-Jun 을 통계적으로 유의하게 감소시킴으로써 MMPs의 발현 감소를 가져온 것으로 보인다. 뿐만 아니라 자외선에 의한 $TNF-{\alpha}$의 생성 또는 유입을 억제함으로써 $TNF-{\alpha}$ receptor에 의해 매개되는 신호전달 경로를 둔화시켜 MMPs의 발현을 감소시킨 것으로 보인다. 이렇게 KTNG0345는 복합적인 활성으로 작용하여 주름생성 억제 활성을 보이는 것으로 판단된다.

• Environmental Analysis Health and Toxicology
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• 제18권2호
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• pp.95-100
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• 2003

본 연구는 환경호르몬(endocrine disruptors)으로 분류되었으며, 제초제로 널리 사용되었던 Dichlorodiphenyltrichloroethane(DDT)가 설치류의 생식세포 중 Leydig 세포의 testosterone(T)생성억제 및 그 관련 작용메카니즘을 규명코자 수행되었다. 먼저 흰쥐의 웅성 생식세포주인 R2C세포에 T의 양 및 aromatase 활성도를 radio immunoassay (RIA)방법을 이용하여 측정하였다. 그 결과 R2C 세포에 황체형성호르몬(LH)를 처리하여 testosterone생성을 증가시킨 후, DDT를 처리한 군들은 대조군에 비하여 농도 의존적으로 T의 양은 감소하였으며, aromatase 활성도는 증가하였다. 또한 DDT자체만 처리한 군에서도 대조군에 비하여 testosterone의 생성이 감소하였다. 이러한 aromatase활성 증가가 estradiol receptor(ER)와의 상호 관련성을 확인하기 위해 ER antagonist인 ICI 182.780를 처리한 후 T의 양 및 aromatase 활성도를 측정한 결과 DDT에 의해 증가된 aromatase활성도가 ICI 182.780에 의해 다시 감소됨을 확인하였다. 또한 DDT에 의해 감소된 T의 양도 ICI 182.780에 의해 다시 회복되었다. In vivo실험으로 흰쥐에 DDT를 직접 투여한 후 정소 내 성 호르몬들을 측정해 본 결과 T의 양은 유의성 있게 감소하였으며, estradiol(E$_2$)의 양은 증가하였으며, aromatase 활성도도 감소하였다. 이러한 결과를 종합해 볼 때 DDT는 aromatase를 감소시키고, 이렇게 감소된 aromatase에 의해 testosterone 생성량을 억제하고, 이러한 DDT의 aromatase의 감소는 ER을 경유하는 것으로 추정할 수 있다.

• 생명과학회지
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• 제28권6호
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• pp.733-737
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• 2018

박과 작물에 함유되어 있는 tetracyclic triterpene 성분 중 하나인 쿠쿠르비타신(cucurbitacin)-I는 대장암, 유방암, 간암세포에서의 항종양 활성이 밝혀져 있으나 난소암에서의 쿠쿠르비타신-I의 역할은 보고된 바 없다. CD44는 세포막에 존재하는 당단백질로 생체 내 리간드인 glycosaminoglycan hyaluronic acid를 통해 세포 외부 매트릭스와 다른 세포와의 접촉을 매개한다. 최근 연구에 의해 CD44의 발현이 난소암세포의 증식 및 세포 부착과 침윤을 증가시키는 주요 원인이라는 것이 보고되었다. 이러한 결과는 CD44의 발현을 억제함으로써 난소암의 진행을 조절할 수 있음을 시사하고 있다. 본 연구에서는 쿠쿠르비타신-I가 난소암세포의 CD44의 발현을 억제할 수 있는 지의 여부를 조사하였다. 인간의 난소암 세포인 SKOV-3를 이용한 MTS assay를 수행한 결과, 쿠쿠르비타신-I는 100 nM이상의 농도에서 세포독성을 나타내었다. 세포독성을 나타내지 않는 농도의 쿠쿠르비타신-I를 SKOV-3 세포에 처리하여 Western blot 분석과 qRT-PCR을 수행한 결과, 쿠쿠르비타신-I에 의해 CD44의 단백질과 mRNA의 발현이 유의적으로 감소되는 것을 확인하였다. 또한 쿠쿠르비타신-I에 의한 CD44의 발현 억제가 $NF-{\kappa}B$와 AP-1의 인산화 감소에 기인하고 있음을 밝혔다. 이러한 결과는 쿠쿠르비타신-I가 CD44 발현을 억제하는 기능을 가지며, 이는 난소암 치료에 도움을 줄 수 있는 제재로서 쿠쿠르비타신-I의 가능성을 제시하는 것이다.

• BMB Reports
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• 제39권3호
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• pp.253-262
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• 2006

Parkinson's disease (PD) is a common neurodegenerative disorder and is characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Although many studies showed that the aggregation of $\alpha$-synuclein might be involved in the pathogenesis of PD, its protective properties against oxidative stress remain to be elucidated. In this study, human wild type and mutant $\alpha$-synuclein genes were fused with a gene fragment encoding the nine amino acid trans activator of transcription (Tat) protein transduction domain of HIV-l in a bacterial expression vector to produce a genetic in-frame WT Tat-$\alpha$-synuclein (wild type) and mutant Tat-a-synucleins (mutants; A30P and A53T), respectively, and we investigated the protective effects of wild type and mutant Tat-$\alpha$-synucleins in vitro and in vivo. WT Tat-$\alpha$-synuclein rapidly transduced into an astrocyte cells and protected the cells against paraquat induced cell death. However, mutant Tat-$\alpha$-synucleins did not protect at all. In the mice models exposed to the herbicide paraquat, the WT Tat-$\alpha$-synuclein completely protected against dopaminergic neuronal cell death, whereas mutants failed in protecting against oxidative stress. We found that these protective effects were characterized by increasing the expression level of heat shock protein 70 (HSP70) in the neuronal cells and this expression level was dependent on the concentration of transduced WT Tat-$\alpha$-synuclein. These results suggest that transduced Tat-$\alpha$-synuclein might protect cell death from oxidative stress by increasing the expression level of HSP70 in vitro and in vivo and this may be of potential therapeutic benefit in the pathogenesis of PD.

• Nutrition Research and Practice
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• 제5권3호
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• pp.219-223
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• 2011

Obesity has been reported to be associated with low grade inflammatory status. In this study, we investigated the inflammatory response as well as associated signaling molecules in immune cells from diet-induced obese mice. Four-week-old C57BL mice were fed diets containing 5% fat (control) or 20% fat and 1% cholesterol (HFD) for 24 weeks. Splenocytes ($1{\times}10^7$ cells) were stimulated with $10\;{\mu}g/mL$ of lipopolysaccharide (LPS) for 6 or 24 hrs. Production of interleukin (IL)-$1{\beta}$, IL-6, and TNF-${\alpha}$ as well as protein expression levels of nucleotide-binding oligomerization domain (NOD)2, signal transducer and activator of transcription (STAT)3, and pSTAT3 were determined. Mice fed HFD gained significantly more body weight compared to mice fed control diet ($28.2{\pm}0.6$ g in HFD and $15.4{\pm}0.8$ g in control). After stimulation with LPS for 6 hrs, production of IL-$1{\beta}$ was significantly higher (P=0.001) and production of tumor necrosis factor (TNF)-${\alpha}$ tended to be higher (P < 0.064) in the HFD group. After 24 hrs of LPS stimulation, splenocytes from the HFD group produced significantly higher levels of IL-6 ($10.02{\pm}0.66$ ng/mL in HFD and $7.33{\pm}0.56$ ng/mL in control, P=0.005) and IL-$1{\beta}$ ($121.34{\pm}12.72$ pg/mL in HFD and $49.74{\pm}6.58$ pg/mL in control, P < 0.001). There were no significant differences in the expression levels of STAT3 and pSTAT3 between the HFD and the control groups. However, the expression level of NOD2 protein as determined by Western blot analysis was 60% higher in the HFD group compared with the control group. NOD2 contributes to the induction of inflammation by activation of nuclear factor ${\kappa}B$. These findings suggest that diet-induced obesity is associated with increased inflammatory response of immune cells, and higher expression of NOD2 may contribute to these changes.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2219-2225
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• 2015

SHP1 negatively regulates the Janus kinase 2/signal transducer and activator of transcription (JAK2/STAT) signaling pathway, which is constitutively activated in myeloproliferative neoplasms (MPNs) and leukemia. Promoter hypermethylation resulting in epigenetic inactivation of SHP1 has been reported in myelomas, leukemias and other cancers. However, whether SHP1 hypermethylation occurs in MPNs, especially in Chinese patients, has remained unclear. Here, we report that aberrant hypermethylation of SHP1 was observed in several leukemic cell lines and bone marrow mononuclear cells from MPN patients. About 51 of 118 (43.2%) MPN patients including 23 of 50 (46%) polycythaemia vera patients, 20 of 50 (40%) essential thrombocythaemia and 8 of 18 (44.4%) idiopathic myelofibrosis showed hypermethylation by methylation-specific polymerase chain reaction. However, SHP1 methylation was not measured in 20 healthy volunteers. Hypermethylation of SHP1 was found in MPN patients with both positive (34/81, 42%) and negative (17/37, 45.9%) JAK2V617F mutation. The levels of SHP1 mRNA were significantly lower in hypermethylated samples than unmethylated samples, suggesting SHP1 may be epigenetically inactivated in MPN patients. Furthermore, treatment with 5-aza-2'-deoxycytidine (AZA) in K562 cells showing hypermethylation of SHP1 led to progressive demethylation of SHP1, with consequently increased reexpression of SHP1. Meanwhile, phosphorylated JAK2 and STAT3 were progressively reduced. Finally, AZA increased the expression of SHP1 in primary MPN cells with hypermethylation of SHP1. Therefore, our data suggest that epigenetic inactivation of SHP1 contributes to the constitutive activation of JAK2/STAT signaling. Restoration of SHP1 expression by AZA may contribute to clinical treatment for MPN patients.

• The Korean Journal of Physiology and Pharmacology
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• 제17권4호
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• pp.291-297
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• 2013

Notch1 has been reported to be highly expressed in triple-negative and other subtypes of breast cancer. Mutant p53 (R280K) is overexpressed in MDA-MB-231 triple-negative human breast cancer cells. The present study aimed to determine whether the mutant p53 can be a potent transcriptional activator of the Notch1 in MDA-MB-231 cells, and explore the role of this mutant p53-Notch1 axis in curcumin-induced apoptosis. We found that curcumin treatment resulted in an induction of apoptosis in MDA-MB-231 cells, together with downregulation of Notch1 and its downstream target, Hes1. This reduction in Notch1 expression was determined to be due to the decreased activity of endogenous mutant p53. We confirmed the suppressive effect of curcumin on Notch1 transcription by performing a Notch1 promoter-driven reporter assay and identified a putative p53-binding site in the Notch1 promoter by EMSA and chromatin immunoprecipitation analysis. Overexpression of mutant p53 increased Notch1 promoter activity, whereas knockdown of mutant p53 by small interfering RNA suppressed Notch1 expression, leading to the induction of cellular apoptosis. Moreover, curcumin-induced apoptosis was further enhanced by the knockdown of Notch1 or mutant p53, but it was decreased by the overexpression of active Notch1. Taken together, our results demonstrate, for the first time, that Notch1 is a transcriptional target of mutant p53 in breast cancer cells and suggest that the targeting of mutant p53 and/or Notch1 may be combined with a chemotherapeutic strategy to improve the response of breast cancer cells to curcumin.

• IMMUNE NETWORK
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• 제6권4호
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• pp.192-198
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• 2006

Background: Investigating strategy to enhance efficiency of gene transfer via adenovirus is critical to sustain gene expression in targeted cells or tissues to regulate immune responses. However, the use of adenovirus as a gene delivery method has been limited by the native tropism of the virus. In this study, the critical parameter is to improve the efficient binding of viral particles to the plasma membrane prior to cellular uptake. Methods: Human immunodeficiency virus (HIV-1) trans-acting activator of transcription (TAT), a protein transduction domain, was fused to the ectodomain of the coxsackie-adenovirus receptor (CAR). The CAR-TAT protein was produced from a Drosophila Schneider 2 cells (S2) transfected with CAR-TAT genes. The function of CARTAT was analyzed the efficiency of adenoviral gene transfer by flow cytometry, and then immunizing AdVGFP with CAR-TAT was transduced on dendritic cells (DCs). Results: S2 transfectants secreting CAR-TAT fusion protein has been stable over a period of 6 months and its expression was verified by western blot. Addition of CAR-TAT induced higher transduction efficiency for AdVGFP at every MOI tested. When mice were vaccinated with DC of which adenoviral transduction was mediated by CAR-TAT, the number of IFN-${\gamma}$ secreting T-cells was increased as compared with those DCs transduced without CAR-TAT. Conclusion: Our data provide evidence that CAR-TAT fusion protein enhances adenoviral transduction and immunogenecity of transgenes on DCs and may influence on the development of adenoviral-mediated anti-tumor immunotherapy.