• Title/Summary/Keyword: Estrogen receptor $\alpha$

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Involvement of Estrogen Receptor-α in the Activation of Nrf2-Antioxidative Signaling Pathways by Silibinin in Pancreatic β-Cells

  • Chu, Chun;Gao, Xiang;Li, Xiang;Zhang, Xiaoying;Ma, Ruixin;Jia, Ying;Li, Dahong;Wang, Dongkai;Xu, Fanxing
    • Biomolecules & Therapeutics
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    • v.28 no.2
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    • pp.163-171
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    • 2020
  • Silibinin exhibits antidiabetic potential by preserving the mass and function of pancreatic β-cells through up-regulation of estrogen receptor-α (ERα) expression. However, the underlying protective mechanism of silibinin in pancreatic β-cells is still unclear. In the current study, we sought to determine whether ERα acts as the target of silibinin for the modulation of antioxidative response in pancreatic β-cells under high glucose and high fat conditions. Our in vivo study revealed that a 4-week oral administration of silibinin (100 mg/kg/day) decreased fasting blood glucose with a concurrent increase in levels of serum insulin in high-fat diet/streptozotocin-induced type 2 diabetic rats. Moreover, expression of ERα, NF-E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) in pancreatic β-cells in pancreatic islets was increased by silibinin treatment. Accordingly, silibinin (10 μM) elevated viability, insulin biosynthesis, and insulin secretion of high glucose/palmitate-treated INS-1 cells accompanied by increased expression of ERα, Nrf2, and HO-1 as well as decreased reactive oxygen species production in vitro. Treatment using an ERα antagonist (MPP) in INS-1 cells or silencing ERα expression in INS-1 and NIT-1 cells with siRNA abolished the protective effects of silibinin. Our study suggests that silibinin activates the Nrf2-antioxidative pathways in pancreatic β-cells through regulation of ERα expression.

Estrogen-related receptor γ is a novel catabolic regulator of osteoarthritis pathogenesis

  • Son, Young-Ok;Chun, Jang-Soo
    • BMB Reports
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    • v.51 no.4
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    • pp.165-166
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    • 2018
  • Osteoarthritis (OA) is the most common form of arthritis and is a leading cause of disability with a large socioeconomic cost. OA is a whole-joint disease characterized by cartilage destruction, synovial inflammation, osteophyte formation, and subchondral bone sclerosis. To date, however, no effective disease-modifying therapies for OA have been developed. The estrogen-related receptors (ERRs), a family of orphan nuclear receptor transcription factors, are composed of $ERR{\alpha}$, $ERR{\beta}$, and $ERR{\gamma}$, which play diverse biological functions such as cellular energy metabolism. However, the role of ERRs in OA pathogenesis has not been studied yet. Among the ERR family members, $ERR{\gamma}$ is markedly upregulated in human and various models of mouse OA cartilage. Adenovirus-mediated overexpression of $ERR{\gamma}$ in the mouse knee joint tissue caused OA pathogenesis. Additionally, cartilage-specific $ERR{\gamma}$ transgenic (Tg) mice exhibited enhanced experimental OA. Consistently, $ERR{\gamma}$ in articular chondrocytes directly caused expression of matrix metalloproteinase (MMP) 3 and MMP13, which play a crucial role in cartilage destruction. In contrast, genetic ablation of Esrrg or shRNA-mediated Esrrg silencing in the joint tissues abrogated experimental OA in mice. These results collectively indicated that $ERR{\gamma}$ is a novel catabolic regulator of OA pathogenesis and can be used as a therapeutic target for OA.

Expression of Monocarboxylate Transporters(MCTs) and Basigin and Estrogen Receptor α(ERα)-Mediated Regulation of MCT1 Expression in The Efferent Ductules of Male Reproductive Tract During Postnatal Development (생후 발달과정동안 남성 생식기의 Efferent Ductules에서 Monocarboxylate Transporters(MCTs)와 Basigin의 발현 양상과 에스트로젠 수용체 α에 의한 MCT1 발현 조절 연구)

  • Lee, Ki-Ho;Choi, I.H.;Chung, C.S.;Chang, J.S.
    • Journal of Animal Science and Technology
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    • v.49 no.3
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    • pp.309-320
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    • 2007
  • The purpose of the present study was to determine if monocarboxylate transporter(MCT) isoforms and Basigin(Bsg) are expressed in the efferent ductules(ED) and if MCT1 expression is under estrogen receptor(ER)α-regulation in the ED of male reproductive tract. The presence of MCT isoforms and Bsg mRNAs was detected by real-time polymerization chain reaction(PCR), and ERα-mediated regulation of MCT1 expression in the ED was indirectly determined by immuno- histochemistry. Current study found differential expression of MCT isoforms(MCT1, 2, 3, 4, and 8) and Bsg mRNAs in rat ED according to postnatal ages. In addition, comparison of MCT1 expression in the ED between wild type and ERα knockout mice at different postnatal ages showed basolateral localization of MCT1 in ciliated cells of the ED and, in part, ERα- mediated regulation of MCT1 expression. It is suggested that MCTs would play a role in regulation of function of the ED.

In Silico Docking Studies of Selected Flavonoids - Natural Healing Agents against Breast Cancer

  • Suganya, Jeyabaskar;Radha, Mahendran;Naorem, Devi Leimarembi;Nishandhini, Marimuthu
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8155-8159
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    • 2014
  • Background: Breast cancer is the serious health concern in India causing the highest mortality rate in females, which occurs due to uncontrolled cell division and can be metastasize to other parts of the human body. Interactions with estrogen receptor (ER) alpha are mainly responsible for the malignant tumors with regulation of the transcription of various genes as a transcription factor. Most of the drugs currently used for the breast cancer treatment produce various side effects and hence we focused on natural compounds which do not exhibit any toxic effect against normal human cells. Materials and Methods: Structure of human ER was retrieved from the Protein Data Bank and the structures of flavonoid compounds have been collected from PubChem database. Molecular docking and drug likeness studies were performed for those natural compounds to evaluate and analyze the anti-breast cancer activity. Results: Finally two compounds satisfying the Lipinski's rule of five were reported. The two compounds also exhibited highest binding affinity with human ER greater than 10.5 Kcal/mol. Conclusions: The results of this study can be implemented in the drug designing pipeline.

Anti-osteoporotic Effects of Unripe Fructus of Rubus coreanus Miquel in Osteoblastic and Osteoclastic Cells

  • Kim, Hyo Jin;Sim, Dong-Soo;Sohn, Eun-Hwa
    • Korean Journal of Plant Resources
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    • v.27 no.6
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    • pp.593-600
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    • 2014
  • Osteoporosis is a progressive bone disease characterized by low bone mass which is caused by disturbance in the balance between the activities of osteoblasts and osteoclasts. Postmenopausal osteoporosis is one of the most common disorders in women after menopause, which is linked to an estrogen deficiency and characterized by an excessive loss of trabecular bone. Rubus coreanus has been used for their various pharmacological properties in Asia as a traditional medicine. To investigate the effect of unripe fruits of R. coreanus 30% ethanol extract (RCE) on osteoblast-like cells (MG63) differentiation, we examined the effects of RCE on in vitro osteoblastic differentiation markers, alkaline phosphatase (ALP) activity and receptor activator of nuclear factor ${\kappa}$-B ligand (RANKL) and osteoprotegerin (OPG) expression. The high concentration (50 and $100{\mu}g/mL$) of RCE markedly increased ALP activity, whereas decreased the RANKL/OPG. We also investigated the effect of RCE on M-CSF plus RANKL-induced differentiation of pre-osteoclast cells (RAW 264.7). RCE treatment remarkably inhibited M-CSF/RANKL-induced formation of osteoclast-like multinuclear cells from RAW 264.7 cells. Moreover, the inhibitory effect of RCE was reduced by selective estrogen receptor-${\alpha}$ antagonist. Our research suggests that suggested that unripe fruits of R. coreanus may act beneficial effects on bone mass by regulating both osteoblast and osteoclast.

17 $\alpha$-ethinylestradiol 과 nonylphenol에 노출된 송사리에서 vitellogenin 및 estrogen receptor의 발현

  • 이철우;박응로;류지성;남규찬;남성숙;구자민;전성환;나진균;최덕일
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2001.05a
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    • pp.132-132
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    • 2001
  • Vitellogenin은 난황단백질의 전구체로서 생체내 발현은 에스트로젠과 에스트로젠 수용체가 반응함으로써 활성화되는 것으로 알려져 있다. 어류의 경우 간에서의 vitellogenin의 합성 및 분비는 성숙된 암컷에서만 일어날 수 있는 현상이나, 과거 여러 실험 결과를 바탕으로 수컷이나 미성숙한 암컷에서도 에스트로젠성 물질에 의해 합성이 유도되는 것으로 밝혀졌다. 따라서 수컷 또는 치어 plasma에서 vitellogenin의 측정은 외인성에스트로젠에 대한 노출을 평가할 수 있는 좋은 수단이 될 수 있다. (중략)

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