Effects of Radix Polygalae on Cognitive Decline and Depression in Estradiol Depletion Mouse Model of Menopause

Postmenopausal syndrome refers to symptoms caused by the gradual decrease in female hormones after mid-40 years. As a target organ of estrogen, decrease in estrogen causes various changes in brain function such as a decrease in choline acetyltransferase and brain-derived neurotrophic factor; thus, postmenopausal women experience cognitive decline and more depressive symptoms than age-matched men. Radix Polygalae has been used for memory boosting and as a mood stabilizer and its components have shown neuroprotective, antidepressant, and stress relief properties. In a mouse model of estrogen depletion induced by 4-vinylcyclohexene diepoxide, Radix Polygalae was orally administered for 3 weeks. In these animals, cognitive and depression-related behaviors and molecular changes related to these behaviors were measured in the prefrontal cortex and hippocampus. Radix Polygalae improved working memory and contextual memory and despair-related behaviors in 4-vinylcyclohexene diepoxide-treated mice without increasing serum estradiol levels in this model. In relation to these behaviors, choline acetyltransferase and brain-derived neurotrophic factor in the prefrontal cortex and hippocampus and bcl-2-associated athanogene expression increased in the hippocampus. These results implicate the possible benefit of Radix Polygalae in use as a supplement of estrogen to prevent conditions such as postmenopausal depression and cognitive decline.     

Genistein: A Potent Anti-Breast Cancer Agent

Genistein is an isoflavonoid present in high quantities in soybeans. Possessing a wide range of bioactives, it is being studied extensively for its tumoricidal effects. Investigations into mechanisms of the anti-cancer activity have revealed many pathways including induction of cell proliferation, suppression of tyrosine kinases, regulation of Hedgehog-Gli1 signaling, modulation of epigenetic activities, seizing of cell cycle and Akt and MEK signaling pathways, among others via which the cancer cell proliferation can be controlled. Notwithstanding, the observed activities have been time- and dose-dependent. In addition, genistein has also shown varying results in women depending on the physiological parameters, such as the early or post-menopausal states.     

HB-EGF induces mitochondrial dysfunction via estrogen hypersecretion in granulosa cells dependent on cAMP-PKA-JNK/ERK-Ca2+-FOXO1 pathway

Polycystic ovarian syndrome (PCOS) is one of the most prevalent endocrinopathies and the leading cause of anovulatory infertility, but its pathogenesis remains elusive. Although HB-EGF is involved in ovarian cancer progression, there is still no clarity about its relevance with PCOS. The present study exhibited that abundant HB-EGF was noted in follicular fluid from PCOS women, where it might induce the granulosa cells (GCs) production of more estrogen via the elevation of CYP19A1 expression after binding to EGFR. Furthermore, HB-EGF transduced intracellular downstream cAMP-PKA signaling to promote the phosphorylation of JNK and ERK whose blockage impeded the induction of HB-EGF on estrogen secretion. Meanwhile, HB-EGF enhanced the accumulation of intracellular Ca²⁺ whose chelation by BAPTA-AM abrogated the stimulation of HB-EGF on FOXO1 along with an obvious diminishment for estrogen production. cAMP-PKA-JNK/ERK-Ca²⁺ pathway played an important role in the crosstalk between HB-EGF and FOXO1. Treatment of GCs with HB-EGF resulted in mitochondrial dysfunction as evinced by the reduction of ATP content, mtDNA copy number and mitochondrial membrane potential. Additionally, HB-EGF facilitated the opening of mitochondrial permeability transition pore via targeting BAX and raised the release of cytochrome C from mitochondria into the cytosol to trigger the apoptosis of GCs, but this effectiveness was counteracted by estrogen receptor antagonist. Collectively, HB-EGF might induce mitochondrial dysfunction and GCs apoptosis through advancing estrogen hypersecretion dependent on cAMP-PKA-JNK/ERK-Ca²⁺-FOXO1 pathway and act as a promising therapeutic target for PCOS.     

SCM-198 Alleviates Endometriosis by Suppressing Estrogen-ERα mediated Differentiation and Function of CD4+CD25+ Regulatory T Cells

Background: Endometriosis (EMS), a typical endocrine immune disorder, associates with dramatically increased estrogen production and disorganized immune response in ectopic focus. Peritoneal regulatory T cells (Tregs) expansion in women with EMS and their pathogenic role attributable to endometriotic immunotolerance has been reported. Whether local high estrogen promotes EMS by discipling Tregs needs to be further explored. Up to date, there is no effective medicine for the treatment of EMS. SCM-198 is a synthetic leonurine with multiple physiological activities. Whether SCM-198 could regulate Tregs via estrogen and facilitate the radical cure of EMS has not yet been reported.Methods: Proportion of Tregs in peritoneal fluid of patients with EMS was firstly analyzed via flow cytometry. Peritoneal estrogen concentration and the mRNA levels of estrogen receptor α (ERα) and estrogen receptor β (ERβ) of Tregs were detected by ELISA and RT-PCR, respectively. Grouped in vitro induction assays were performed to explore the effects of SCM-198 and estrogen signaling on Tregs. Cell invasion and viability assays were utilized to detect the crosstalk between Tregs and ectopic endometrial stromal cells (eESCs), with or without SCM-198 treatment. Furthermore, EMS mice models were established to verify the therapeutic effects of SCM-198.Results: Increased Tregs were found in peritoneal fluid of EMS patients, accompanied with estrogen-ERα overactivation. Estrogen-ERα triggered the expansion of Tregs and their cytokine production (IL-10 and TGF-β1), which could be reversed by SCM-198 treatment. Moreover, SCM-198 abated the invasion and viability of eESCs enhanced by Tregs. In vivo experiments confirmed that SCM-198 obviously retarded the growth of ectopic lesions and downregulated the functions of Tregs via estrogen-ERα inactivation.Conclusions: These data suggest that SCM-198 attenuates Tregs expansion via the inhibition of estrogen-ERα signaling in EMS and offer a promising therapy for such a refractory disease.     

针刺对去卵巢大鼠脑内胆碱乙酰转移酶基因表达的影响

本工作旨在探讨雌激素对脑内乙酰胆碱生成的影响和电针刺激“足三里”穴对去卵巢大鼠脑内乙酰胆碱生成的调整作用。实验选用成年Wistar雌性大鼠,将动物分为正常对照组(INT)、去卵巢组(OVX)和去卵巢针刺组(OVX AC)。用放射免疫分析方法测定血中雌二醇含量,采用RT-PCR方法获得大鼠脑内胆碱乙酰转移酶(ChAT)mRNA的逆转录表达产物——cDNA,用琼脂糖凝胶电泳方法检测,并通过原位杂交方法观察海马ChAT mRNA阳性神经元的表达,然后用计算机图像分析系统进行统计分析。实验结果显示：去卵巢组大鼠体内雌激素水平明显降低,脑内ChAT mRNA的RT-PCR产物和海马ChAT mRNA阳性表达产物的平均面积、平均积分光度值均明显减少,与对照组和针刺组比较有显著性差异;去卵巢针刺“足三里”穴组与去卵巢组相比,大鼠血中雌激素水平明显升高,脑内ChAT mRNA RT-PCR产物明显增多,海马的ChAT mRNA表达阳性神经元增多。以上结果提示：脑内ChAT基因表达与体内雌激素水平有密切关系,去卵巢后针刺“足三里”穴对ChAT的调节作用可能是针刺增强脑内乙酰胆碱含量的机制之一。     

Estrogen receptor-alpha gene haplotype is associated with primary knee osteoarthritis in Korean population

Estrogen and estrogen receptors (ERs) are known to play important roles in the pathophysiology of osteoarthritis (OA). To investigate ER-alpha gene polymorphisms for its associations with primary knee OA, we conducted a case-control association study in patients with primary knee OA (n = 151) and healthy individuals (n = 397) in the Korean population. Haplotyping analysis was used to determine the relationship between three polymorphisms in the ER-alpha gene (intron 1 T/C, intron 1 A/G and exon 8 G/A) and primary knee OA. Genotypes of the ER-alpha gene polymorphism were determined by PCR followed by restriction enzyme digestion (PvuII for intron 1 T/C, XbaI for intron 1 A/G, and BtgI for exon 8 G/A polymorphism). There was no significant difference between primary knee OA patients and healthy control individuals in the distribution of any of the genotypes evaluated. However, we found that the allele frequency for the exon 8 G/A BtgI polymorphism (codon 594) was significantly different between primary knee OA patients and control individuals (odds ratio = 1.38, 95% confidence interval = 1.01-1.88; P = 0.044). In haplotype frequency estimation analysis, there was a significant difference between primary knee OA patients and control individuals (degrees of freedom = 7, chi2 = 21.48; P = 0.003). Although the number OA patients studied is small, the present study shows that ER-alpha gene haplotype may be associated with primary knee OA, and genetic variations in the ER-alpha gene may be involved in OA.     

Estrogenic activity of an environmental pollutant, 2-nitrofluorene,after metabolic activation by rat liver microsomes

In this study, the metabolic activation of 2-nitrofluorene (NF) to estrogenic compounds was examined. NF was negative in estrogen reporter assays using estrogen-responsive yeast and human breast cancer cell line MCF-7. However, the compound exhibited estrogenic activity after incubation with liver microsomes of 3-methylcholanthrene-treated rats in the presence of NADPH. Minor estrogenic activity was observed when liver microsomes of untreated or phenobarbital-treated rats were used instead of those from 3-methylcholanthrene-treated rats. When the compound was incubated with the liver microsomes of 3-methylcholanthrene-treated rats in the presence of NADPH, 7-hydroxy-2-nitrofluorene (7-OH-NF) was formed as a major metabolite. However, little of the metabolite was formed by liver microsomes of untreated or phenobarbital-treated rats. Rat recombinant cytochrome P450 1A1 exhibited a significant oxidase activity toward NF, affording 7-OH-NF. Liver microsomes of phenobarbital-treated rats also enhanced oxidase activity toward NF. In this case, 9-hydroxy-2-nitrofluorene was formed. 7-OH-NF exhibited a significant estrogenic activity, while the activity of 9-hydroxy-2-nitrofluorene was much lower. These results suggest that the estrogenic activity of NF was due to formation of the 7-hydroxylated metabolite by liver microsomes.