A phytoestrogen diarylheptanoid mediates estrogen receptor/Akt/glycogen synthase kinase 3β protein-dependent activation of the Wnt/β-catenin signaling pathway

Effect of estradiol after bacterial infection on the Wnt/β-catenin pathway in bovine endometrium epithelial cells and organoids

Endometritis is a disease caused by a postpartum bacterial infection with a poor prognosis that primarily affects dairy cows. Three-dimensional organoids have been used as a model for endometritis, because they exhibit a structure comparable to that of the endometrium, demonstrating both expansibility and hormone responsiveness. These characteristics render them an ideal platform for in vitro investigations of endometrial diseases. Estradiol (E2) is an endogenous steroid hormone with demonstrated anti-inflammatory properties, and the objective of this study was to determine the mechanism by which E2 modulates the inflammatory response and the Wnt signal transduction pathway in bovine endometrial epithelial cells and organoids following E. coli infection. We present the techniques for isolating and culturing primary bovine endometrial epithelial cells (BEECs), and producing endometrial organoids. For the experiments, the endometrial epithelial cells and organoids were infected with E. coli for 1 h, followed by incubation with E2 for 12 h. The mRNA and protein expressions of the inflammation-related genes, IL-1β, IL-6, TLR4, and NF-κB, as well as the Wnt pathway-related genes, Wnt4, β-catenin, c-Myc, and CyclinD1, were assessed using real-time quantitative-PCR and western blotting, respectively. The CCK8 viable cell counting assay was utilized to determine the optimal concentration of the Wnt inhibitor, IWR-1. The mRNA and protein expression of Wnt pathway-related genes was assessed following IWR-1 treatment, while the expression levels of proliferation-associated genes (Ki67, PCNA) and barrier repair genes (occludin, claudin, and Zo-1) in BEECs and organoids were evaluated after E2 treatment. The results of this study show that mRNA expression of the inflammatory genes, IL-1β, TLR4, and NF-κB (P < 0.05) decreased in BEECs following E2 treatment compared to the E. coli group. The protein expression of the IL-1β, IL-6, TLR4 and NF-κB genes was also inhibited (P < 0.05). Similar results were observed in tests on the organoids. Our findings demonstrate that E2 significantly upregulates the expression of Wnt-related genes, including β-catenin and c-Myc, while concurrently downregulating the expression of GSK3β (P < 0.05). Next, we treated E. coli-infected BEECs and organoids with the Wnt inhibitor, IWR-1. Compared with E. coli and E. coli + E2, the expression of mRNA and protein from Wnt 4, β-catenin, and CyclinD1 in E. coli + E2 and E. coli + IWR-1 was down-regulated (P < 0.05). The expression of the proliferation genes, Ki67, PCNA, and the tight junction genes, occludin, claudin1, and Zo-1, in organoids was significantly higher than that in BEECs (P < 0.05). In summary, we found strong potential for E2 mitigation of the E. coli-induced inflammatory response in BEECs and organoids, through activation of the Wnt pathway. In addition, the proliferation and repair capacity of organoids was much higher than that of BEECs.

Improving hematopoietic differentiation from human induced pluripotent stem cells by the modulation of Hippo signaling with a diarylheptanoid derivative

BACKGROUND

The diarylheptanoid ASPP 049 has improved the quality of adult hematopoietic stem cell (HSC) expansion ex vivo through long-term reconstitution in animal models. However, its effect on hematopoietic regeneration from human induced pluripotent stem cells (hiPSCs) is unknown.

METHOD

We utilized a defined cocktail of cytokines without serum or feeder followed by the supplementation of ASPP 049 to produce hematopoietic stem/progenitor cells (HSPCs). Flow cytometry and trypan blue exclusion analysis were used to identify nonadherent and adherent cells. Nonadherent cells were harvested to investigate the effect of ASPP 049 on multipotency using LTC-IC and CFU assays. Subsequently, the mechanism of action was explored through transcriptomic profiles, which were validated by qRT-PCR, immunoblotting, and immunofluorescence analysis.

RESULT

The supplementation of ASPP 049 increased the number of phenotypically defined primitive HSPCs (CD34+CD45+CD90+) two-fold relative to seeded hiPSC colonies, indicating enhanced HSC derivation from hiPSCs. Under ASPP 049-supplemented conditions, we observed elevated HSPC niches, including CD144+CD73- hemogenic- and CD144+CD73+ vascular-endothelial progenitors, during HSC differentiation. Moreover, harvested ASPP 049-treated cells exhibited improved self-renewal and a significantly larger proportion of different blood cell colonies with unbiased lineages, indicating enhanced HSC stemness properties. Transcriptomics and KEGG analysis of sorted CD34+CD45+ cells-related mRNA profiles revealed that the Hippo signaling pathway is the most significant in responding to WWTR1/TAZ, which correlates with the validation of the protein expression. Interestingly, ASPP 049-supplemented HSPCs upregulated 11 genes similarly to umbilical cord blood-derived HSPCs.

CONCLUSION

These findings suggest that ASPP 049 can improve HSC-generating protocols with proliferative potentials, self-renewal ability, unbiased differentiation, and a definable mechanism of action for the clinical perspective of hematopoietic regenerative medicine.

17β-estradiol mitigates the inhibition of SH-SY5Y cell differentiation through WNT1 expression

17β-estradiol (E2) and canonical WNT-signaling represent crucial regulatory pathways for microtubule dynamics and synaptic formation. However, it is unclear yet whether E2-induced canonical WNT ligands have significant impact on neurogenic repair under inflammatory condition. In this study, first, we prepared the chronic activated-microglial-conditioned media, known to be comprised of neuro-inflammatory components. Long term exposure of microglial conditioned media to SH-SY5Y cells showed a negative impact on differentiation markers, microtubule associated protein-2 (MAP2) and synaptophysin (SYP), which was successfully rescued by pre and co-treatment of 10 nM 17β-estradiol. The inhibition of estrogen receptors, ERα and ERβ significantly blocked the E2-mediated recovery in the expression of differentiation marker, SYP. Furthermore, the inflammatory inhibition of canonical signaling ligand, WNT1 was also found to be rescued by E2. To our surprise, E2 was unable to replicate this success with β-catenin, which is considered to be the intracellular transducer of canonical WNT signaling. However, WNT antagonist - Dkk1 blocked the E2-mediated recovery in the expression of the differentiation marker, MAP2. Therefore, our data suggests that E2-mediated recovery in SH-SY5Y differentiation follows a divergent pathway from the conventional canonical WNT signaling pathway, which seems to regulate microtubule stability without the involvement of β-catenin. This mechanism provides fresh insight into how estradiol contributes to the restoration of differentiation marker proteins in the context of chronic neuroinflammation.

Ap-2β regulates cranial osteogenic potential via the activation of Wnt/β-catenin signaling pathway

The skull is a fundamental bone that protects the development of brain and consists of several bony elements, such as the frontal and parietal bones. Frontal bone exhibited superior in osteogenic potential and regeneration of cranial defects compared to parietal bone. However, how this regional difference is regulated remains largely unknown. In this study, we identified an Ap-2β transcriptional factor with a higher expression in frontal bone, but its molecular function in osteoblasts needs to be elucidated. We found that Ap-2β knockdown in preosteoblasts leads to reduced proliferation, increased cell death and impaired differentiation. Through RNA-seq analysis, we found that Ap-2β influences multiple signaling pathways including the Wnt pathway, and overexpression of Ap-2β showed increased nuclear β-catenin and its target genes expressions in osteoblasts. Pharmacological activation of Wnt/β-catenin signaling using LiCl treatment cannot rescue the reduced luciferase activities of the β-catenin/TCF/LEF reporter in Ap-2β knockdown preosteoblasts. Besides, transient expression of Ap-2β via the lentivirus system could sufficiently rescue the inferior osteogenic potential in parietal osteoblasts, while Ap-2β knockdown in frontal osteoblasts resulted in reduced osteoblast activity, reduced active β-catenin and target genes expressions. Taken together, our data demonstrated that Ap-2β modulates osteoblast proliferation and differentiation through the regulation of Wnt/β-catenin signaling pathway and plays an important role in regulating regional osteogenic potential in frontal and parietal bone.

Understanding the mechanistic potential of plant based phytochemicals in management of postmenopausal osteoporosis

Postmenopausal osteoporosis, an epidemic disorder is defined as a loss in bone mineral density and a greater possibility of fractures in older women. It is a multifactorial disease under the control of various genetic, hormonal, and environmental factors. Insufficiency of estrogen hormone, leads to postmenopausal osteoporosis. Hormone replacement therapy (HRT), despite being the most effective treatment, it is associated with the risk of breast cancer and cardiovascular disorders. This review seeks to compile the most recent information on medicinal plants and natural compounds used to treat and prevent postmenopausal osteoporosis. Furthermore, the origin, chemical constituents and the molecular mechanisms responsible for this therapeutic and preventive effect are also discussed. Literature research was conducted using PubMed, Science direct, Scopus, Web of Science, and Google Scholar. Different plant extracts and pure compounds exerts their antiosteoporotic activity by inhibition of RANKL and upregulation of OPG. RANKL signaling regulates osteoclast formation, characterized by increased bone turnover and osteoprotegrin is a decoy receptor for RANKL thereby preventing bone loss from excessive resorption. In addition, this review also includes the chemical structure of bioactive compounds acting on NFκB, TNF α, RUNX2. In conclusion, we propose that postmenopausal osteoporosis could be prevented or treated with herbal products.

Crosstalk between the gut microbiota and postmenopausal osteoporosis: Mechanisms and applications

Postmenopausal osteoporosis (PMO) results from a reduction in bone mass and microarchitectural deterioration in bone tissue due to estrogen deficiency, which may increase the incidence of fragility fractures. The number of people suffering from PMO has increased over the years because of the rapidly aging population worldwide. However, several pharmacological agents for the treatment of PMO have many safety risks and impose a heavy financial burden to patients and society. In recent years, the "gut-bone" axis has been proposed as a new approach in the prevention and treatment of PMO. This paper reviews the relationship between the gut microbiota and PMO, which mainly includes the underlying mechanisms between hormones, immunity, nutrient metabolism, metabolites of the gut microbiota and intestinal permeability, and explores the possible role of the gut microbiota in these processes. Finally, we discuss the therapeutic effects of diet, prebiotics, probiotics, and fecal microbiota transplantation on the gut microbiota.

Enhancing Erythropoiesis by a Phytoestrogen Diarylheptanoid from Curcuma comosa

Erythropoietin (Epo) is widely used for the treatment of anemia; however, non-hematopoietic effects and cancer risk limit its clinical applications. Therefore, alternative molecules to improve erythropoiesis in anemia patients are urgently needed. Here, we investigated the potential effects of a phytoestrogen diarylheptanoid (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol, (ASPP 049) isolated from Curcuma comosa on promoting erythropoiesis. Treatment with C. comosa extract improved anemia symptoms demonstrated by increasing red blood cell numbers, hematocrit, and hemoglobin content in anemic mice. In addition, ASPP 049, the major compound isolated from C. comosa, enhanced the suboptimal Epo dosages to improve erythroid cell differentiation from hematopoietic stem cells, which was inhibited by the estrogen receptor (ER) antagonist, ICI 182,780. Moreover, the ASPP 049-activated Epo-Epo receptor (EpoR) complex subsequently induced phosphorylation of EpoR-mediated erythropoiesis pathways: STAT5, MAPK/ERK, and PI3K/AKT in Epo-sensitive UT-7 cells. Taken together, these results suggest that C. comosa extract and ASPP 049 increased erythropoiesis through ER- and EpoR-mediated signaling cascades. Our findings provide insight into the specific interaction between a phytoestrogen diarylheptanoid and Epo-EpoR in a hematopoietic system for the potential treatment of anemia.

Ex vivo expansion and functional activity preservation of adult hematopoietic stem cells by a diarylheptanoid from Curcuma comosa

Hematopoietic stem cells (HSCs, CD34+ cells) have shown therapeutic efficacy for transplantation in various hematological disorders. However, a large quantity of HSCs is required for transplantation. Therefore, strategies to increase HSC numbers and preserve HSC functions through ex vivo culture are critically required. Here, we report that expansion medium supplemented with ASPP 049, a diarylheptanoid isolated from Curcuma comosa, and a cocktail of cytokines markedly increased numbers of adult CD34+ cells. Interestingly, phenotypically defined primitive HSCs (CD34+CD38-CD90+) were significantly increased under ASPP 049 treatment relative to control. ASPP 049 treatment also improved two functional properties of HSCs, as evidenced by an increased number of CD34+CD38- cells in secondary culture (self-renewal) and the growth of colony-forming units as assessed by colony formation assay (multilineage differentiation). Transplantation of cultured CD34+ cells into immunodeficient mice demonstrated the long-term reconstitution and differentiation ability of ASPP 049-expanded cells. RNA sequencing and KEGG analysis revealed that Hippo signaling was the most likely pathway involved in the effects of ASPP 049. These results suggest that ASPP 049 improved ex vivo expansion and functional preservation of expanded HSCs. Our findings provide a rationale for the use of ASPP 049 to grow HSCs prior to hematological disease treatment.

Experimental and molecular docking studies of estrogen-like and anti-osteoporosis activity of compounds in Fructus Psoraleae

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus Psoraleae (FP), dry mature fruits of Cullen corylifolium (L.) Medik., has been used clinically to treat kidney yang deficiency-induced impotence, asthma and cold pain in waist and knee caused by kidney deficiency. A study of the source of the significant kidney-enhancing effect of FP revealed that it may be due to its strong estrogen-like activity.

AIM OF THE STUDY

This study aimed to investigate the estrogen-like activity of the FP extract and 13 bioactive compounds in it, as well as the mechanisms underlying their estrogen-like and anti-osteoporosis activities.

MATERIALS AND METHODS

The estrogen-like activities of the 75% ethanol-only FP extract, and 75% ethanol plus petroleum ether, ethyl acetate, n-butanol or water FP extracts were each measured using Cell Counting Kit-8 (CCK-8) and luciferase reporter gene assays. The compounds were identified by high-performance liquid chromatography analysis. The activation of estrogen receptor signaling by the compounds was compared with that by estradiol (E₂) using the molecular docking software MOE-Dock 2008.10. The activation of the ER-Wnt-β-catenin signaling pathway was investigated using an alkaline phosphatase (ALP) assay, qPCR analysis and Western blot analysis.

RESULTS

The results revealed that the 75% ethanol plus ethyl acetate extract showed the highest estrogen-like activity among the four 75% ethanol extract fractions (further extracted with petroleum ether, ethyl acetate, n-butanol or water). Some compounds in FP showed strong estrogenic effect and anti-osteoporosis activity, and activated the Wnt-β-catenin pathway. The isoflavone compound was the most active.

CONCLUSIONS

This study demonstrated that FP has a strong estrogen-like activity and some of its component compounds have anti-osteoporosis activity by activating the ER-Wnt-β-catenin signaling pathway. Our detections provide a new insight into the mechanisms underlying the estrogen-like and anti-osteoporosis activities of FP, as well as a better understanding of structure effects.

7,8-Dihydroxyflavone modulates bone formation and resorption and ameliorates ovariectomy-induced osteoporosis

Imbalances in bone formation and resorption cause osteoporosis. Mounting evidence supports that brain-derived neurotrophic factor (BDNF) implicates in this process. 7,8-Dihydroxyflavone (7,8-DHF), a plant-derived small molecular TrkB agonist, mimics the functions of BDNF. We show that both BDNF and 7,8-DHF promoted the proliferation, osteogenic differentiation, and mineralization of MC3T3-E1 cells. These effects might be attributed to the activation of the Wnt/β-catenin signaling pathway as the expression of cyclin D1, phosphorylated-glycogen synthase kinase-3β (p-GSK3β), β-catenin, Runx2, Osterix, and osteoprotegerin (OPG) was all significantly up-regulated. Knockdown of β-catenin restrained the up-regulation of Runx2 and Osterix stimulated by 7,8-DHF. In particular, blocking TrkB by its specific inhibitor K252a suppressed 7,8-DHF-induced osteoblastic proliferation, differentiation, and expression of osteoblastogenic genes. Moreover, BDNF and 7,8-DHF repressed osteoclastic differentiation of RAW264.7 cells. The transcription factor c-fos and osteoclastic genes such as tartrate-resistant acid phosphatase (TRAP), matrix metalloprotein-9 (MMP-9), Adamts5 were inhibited by 7,8-DHF. More importantly, 7,8-DHF attenuated bone loss, improved trabecular microarchitecture, tibial biomechanical properties, and bone biochemical indexes in an ovariectomy (OVX) rat model. The current work highlights the dual regulatory effects that 7,8-DHF exerts on bone remodeling.

G Protein-Coupled Estrogen Receptor Correlates With Dkk2 Expression and Has Prognostic Impact in Ovarian Cancer Patients

PURPOSE

Wnt pathway modulator Dickkopf 2 (Dkk2) and signaling of the G protein-coupled estrogen receptor (GPER) seem to have essential functions in numerous cancer types. For epithelial ovarian cancer (EOC), it has not been proven if either Dkk2 or the GPER on its own have an independent impact on overall survival (OS). So far, the correlation of both factors and their clinical significance has not systematically been investigated before.

METHODS

Expression levels of Dkk2 were immunohistochemically analyzed in 156 patient samples from different histologic subtypes of EOC applying the immune-reactivity score (IRS). Expression analyses were correlated with clinical and pathological parameters to assess for prognostic relevance. Data analysis was performed using Spearman's correlations, Kruskal-Wallis-test and Kaplan-Meier estimates.

RESULTS

Highest Dkk2 expression of all subtypes was observed in clear cell carcinoma. In addition, Dkk2 expression differed significantly (p<0.001) between low and high grade serous ovarian cancer. A significant correlation of Dkk2 with the cytoplasmic GPER expression was noted (p=0.001) but not for the nuclear estrogen receptor alpha (ERα) or beta (ERβ). Patients exhibiting both, high expression Dkk2 (IRS>4) and GPER (IRS>8), had a significantly better overall survival compared to patients with low expression (61 months vs. 33 months; p=0.024).

CONCLUSION

Dkk2 and GPER expression correlates in EOC and combined expression of both is associated with improved OS. These findings underline the clinical significance of both pathways and indicate a possible prognostic impact as well as a potential for treatment strategies addressing interactions between estrogen and Wnt signaling in ovarian cancer.

Inhibition of Adipogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells by a Phytoestrogen Diarylheptanoid from Curcuma comosa

We investigated the effect of a phytoestrogen, (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol (DPHD), from Curcuma comosa Roxb. (Zingiberaceae family) on the adipogenic differentiation of mesenchymal progenitors, human bone marrow-derived mesenchymal stem cells (hBMSCs). DPHD inhibited adipocyte differentiation of hBMSCs by suppressing the expression of genes involved in adipogenesis. DPHD at concentrations of 0.1, 1, and 10 μM significantly decreased triglyceride accumulation in hBMSCs to 7.1 ± 0.2, 6.3 ± 0.4, and 4.9 ± 0.2 mg/dL, respectively, compared to the nontreated control (10.1 ± 0.9 mg/dL) (p < 0.01). Based on gene expression profiling, DPHD increased the expression of several genes involved in the Wnt/β-catenin signaling pathway, a negative regulator of adipocyte differentiation in hBMSCs. DPHD also increased the levels of essential signaling proteins which are extracellular signal-regulated kinases 1 and 2 (ERK1/2) and glycogen synthase kinase 3 beta (GSK-3β) that link estrogen receptor (ER) signaling to Wnt/β-catenin signaling. In conclusion, DPHD exhibited the anti-adipogenic effect in hBMSCs by suppression of adipogenic markers in hBMSCs through the activation of ER and Wnt/β catenin signaling pathways. This finding suggests the potential role of DPHD in preventing bone marrow adiposity which is one of the major factors that exacerbates osteoporosis in postmenopause.

Aberrant canonical Wnt signaling: Phytochemical based modulation

BACKGROUND

Wnt signaling pathway plays a major role during development like gastrulation, axis formation, organ development and organization of body plan development. Wnt signaling aberration has been linked with various disease conditions like osteoporosis, colon cancer, hair follicle tumor, Leukemia, and Alzheimer's disease. Phytochemicals like flavonoid, glycosides, polyphenols, have been reported to directly target the markers of Wnt signaling in different disease models.

PURPOSE

The study deals in detail about the different phytochemical targeting key players of Wnt signaling pathway in diseases like Cancer, Osteoporosis, and Alzheimer's disease. We have focused on the Pharmacological basis of disease alleviation by phytochemical specifically targeting the Wnt signaling markers in this study.

METHODS

The study focused on the published articles from the preclinical rodent and invitro cell line studies related to Wnt signaling and Phytochemicals related to Cancer, Alzheimer's and Osteoporosis. The electronic databases Scopus, Web of Science and Pubmed database were used for the systematic search of literatures from 2005 up to 2019 using keywords Canonical Wnt signaling pathway, Cancer, Alzheimer's disease, Osteoporosis, Phytochemicals. The focus was to identify the target specific modulation of Wnt signaling mediated by phytochemicals.

RESULTS

Approximately 30 phytochemicals of different class have been identified to modulate Wnt signaling pathway acting through Axin, β-catenin translocation, GSK-3β, AKT, Wif-1 in various experimental studies. The down regulation of Wnt signaling is observed in Cancer mostly colorectal cancer, breast cancer mediated through mutations in APC and Axin genes. Different class of Phytochemicals such as flavonoid, glycosides, polyphenol, alkaloids etc. have been found to target Wnt signaling markers and alleviate Cancer. Similarly, Up regulation of Wnt signaling has been reported in Osteoporosis and neurodegenerative disease like Alzheimer's disease.

CONCLUSION

This review highlights the possibility of the Phytochemicals to target Wnt markers and its potential to either activate or deactivate the Wnt signaling pathway. It also describes the challenges in proper targeting of Wnt signaling and the potential risk and consequences of either up regulation or down regulation of the signaling pathway. This article highlights the possibility of Wnt signaling pathway as a therapeutic option in different diseases.

Low bone mass is associated with carotid calcification plaque in Chinese postmenopausal women: the Chongqing osteoporosis study

Background: The aim of this study was to examine the relationship between low bone mass and the risk of carotid calcification plaques in Chinese postmenopausal women.Methods: We conducted a 5 years prospective study. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) scanning. Carotid computed tomography angiography (CTA) was conducted using a 64-multidetector row scanner to assess carotid arterial plaque at baseline and during follow-up. Cox proportional hazards analysis was used to evaluate the association of BMD and risk of carotid calcification plaques.Results: Four hundred and eighty-eight women sustained prospective carotid plaques during the follow-up. Women with carotid calcification plaques had low BMD than those with carotid non-calcification plaques. After adjustment for potential confounders, BMD, age, years since menopause, levels of plasma osteoprotegerin and adiponectin, hypertension, diabetes mellitus and hyperlipidemia were independently associated with increased risk of carotid calcification plaques. For carotid calcification plaques, a significant inverse correlation was indicated between BMD and the plaques, and a significant positive correlation was indicated between bone loss and plaques.Conclusions: This study suggested that lower BMD and increased loss rate of BMD were associated with a higher risk of carotid calcification plaques in Chinese postmenopausal women.

Effect and mechanism of psoralidin on promoting osteogenesis and inhibiting adipogenesis

BACKGROUND

Psoralidin (PL), a prenylated coumestrol, is isolated from Psoralea corylifolia L. (Fabaceae), which is frequently used for treatment of osteoporosis.

PURPOSE

This study was designed to investigate the dual effects and potential mechanism of PL on promoting osteogenesis and inhibiting adipogenesis.

METHODS

Bone marrow mesenchymal stem cells (BMSCs) were used to investigate the effect of PL on stimulating osteogenesis and inhibiting adipogenesis, while preosteoblast MC3T3-E1 cells and preadipocyte 3T3-L1 cells were employed to explore the potential mechanisms. Estradiol (E₂) and ICI 182,780 (ICI) were used as the specific agonist and antagonist of classical estrogen receptors (ER), respectively, to interfere with classical ER signaling. Meanwhile, G-1 and G-15 were introduced as the selective agonist and antagonist of G protein coupled receptor 30 (GRP30, a membrane ER) to further clarify if membrane ER involved in PL mediating osteogenesis and adipogenesis RESULTS: PL not only promoted mineralization, but also inhibited adipocytes formation of BMSCs. In terms of osteogenesis, PL enhanced calcium nodule formation, alkaline phosphatase activity and osteocalcin levels in MC3T3-E1 cells. As for adipogenesis, PL decreased adipocyte formation in 3T3-L1 cells through down-regulating several mRNA expressions and protein synthesis of adipogenesis related factors. ICI completely blocked the effect of PL in promoting osteogenesis, but only partially suppressed its effect in inhibition of adipogenesis, while G-15 partially suppressed the effect of PL on promoting mineralization and inhibiting oil drop formation. Furthermore, during suppression of adipocyte differentiation, PL regulated protein kinase B / glycogen synthase kinase 3β / β-catenin signaling pathway.

CONCLUSION

PL promoted osteogenesis via mediating classical ER pathway, and inhibited adipocytes formation by regulating combined classical and membrane ER pathways. PL might be a potential candidate for the treatment of postmenopausal osteoporosis by modulating the competitive relationship between osteogenesis and adipogenesis of bone marrow mesenchymal stem cells.

17β-Estradiol attenuates the influence of chronic activated microglia on SH-SY5Y cell proliferation via canonical WNT signaling pathway

The decline in circulating estrogen following menopause or aging is likely to initiate chronic inflammatory disorders, leading to neurodegenerative disease. Though, WNT1 paracrine molecules are crucial in embryonic neuroblastoma cell proliferation, very less is known about its role in adult brain that is associated with estrogen as preventive therapeutic strategy. The present study evidenced for the first time that 17β-estradiol (E2), a potent form of estrogen, could compensate the chronic neuroinflammation-associated loss of neurons by upregulating canonical WNT signaling pathway. Lipopolysaccharide was used to induce inflammatory responses in microglial cell line. The increased secretion of IL-6 cytokine was confirmed as a marker of chronic microglial activation. LPS-conditioned microglial media significantly reduced the viable cells and proliferative markers, BrdU and CyclinD1 in SH-SY5Y. It also decreased the expression of canonical WNT signaling components; WNT1 and β-catenin, which were significantly rescued with pre- and co-treatment of 10 nM E2. Furthermore, estrogen antagonist ICI 182,780 abolished the E2-mediated recovery in WNT1 expression. Whereas, canonical WNT receptor antagonist, Dkk1 was able to inhibit E2-mediated recovery in the expression of downstream component, β-catenin. It suggests a promising role of canonical WNT signaling pathway in estrogen mediated prevention of neuronal cell loss under chronic neuroinflammatory condition.

Preparation of Curcuma comosa tablets using liquisolid techniques: In vitro and in vivo evaluation

Curcuma comosa (C. comosa) is a Thai medicinal herb that provides numerous pharmacologic activities due to its estrogen-like action. This study aimed to investigate the use of liquisolid technique to prepare tablets containing oleoresin-like crude extract of C. comosa, and to improve the dissolution profiles of its major compounds, diarylheptanoids (DAs). Free flowing powders of C. comosa extract were obtained by adsorption onto solid carriers, microcrystalline cellulose, with colloidal silica as coating material. FTIR results ruled out possible interactions between C. comosa extract and excipients. The results indicated that all of liquisolid tablets met the USP requirements. The release of DAs were significantly increased through liquisolid formulations, compared to crude extract. By decreasing the ratio of carrier to coating from 20 to 10, an improvement in dissolution rate was observed. Addition of additives - namely polymer (polyvinyl pyrrolidone) and/or nonvolatile liquid (propylene glycol) affected tablet properties which involved longer disintegration time and lower DA dissolution. Optimized C. comosa liquisolid formulation was prepared in a carrier to coating ratio of 10 without additives. Stability studies showed that physical properties of liquisolid tablet were not affected by aging, but percent remaining and dissolution profiles of DAs were influenced by storage temperature. In vivo pharmacokinetic behavior of the optimized C. comosa liquisolid tablets was investigated following a single oral administration to rabbits. The results proved that the method used for preparation of liquisolid led to C. comosa tablets with low variation in content uniformity and tablet properties, as well as enhanced dissolution behavior.

Geraniin promotes osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) via activating β-catenin: a comparative study between BMSCs from normal and osteoporotic rats

Abnormal osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) has been correlated with the pathogenesis of osteoporosis. Geraniin, a polyphenolic compound isolated from Phyllanthus amarus, is effective in preventing osteoporosis, but the mechanisms of action of geraniin and the impact of osteoporotic condition on drug action are not known. In this study we compared the proliferation and osteoblastic differentiation potential of BMSCs from normal rats with that from osteoporotic rats, and examined the responses of both BMSCs to geraniin in parallel. BMSCs of rats subjected to ovariectomy or sham operation were isolated and treated with geraniin. Cell proliferation was measured by CCK-8 assay. Osteoblastic differentiation was quantified by Alizarin Red S staining and alkaline phosphatase assay. Nuclear translocation of β-catenin was monitored by immunofluorescent staining. Expression of β-catenin was determined by Western blot and quantitative real-time polymerase chain reaction. Results showed that the proliferation and osteoblast formation of osteoporotic BMSCs decreased in comparison to that of normal BMSCs. Geraniin enhanced proliferation and osteoblastic differentiation of both BMSCs, but the responses of osteoporotic BMSCs to geraniin were less than those of normal BMSCs. Expression and nuclear accumulation of β-catenin in osteoporotic BMSCs were found to be diminished. Geraniin increased nuclear translocation and expression of β-catenin in both BMSCs. This study associated the osteogenic effect of geraniin to activation of Wnt/β-catenin signaling, and provided rationale for pharmacological investigation of geraniin in osteoporosis prevention and treatment.

The anti-cancer activity of an andrographolide analogue functions through a GSK-3β-independent Wnt/β-catenin signaling pathway in colorectal cancer cells

The Wnt/β-catenin signaling pathway plays a key role in the progression of human colorectal cancers (CRCs) and is one of the leading targets of chemotherapy agents developed for CRC. The present study aimed to investigate the anti-cancer effects and molecular mechanisms of 19-O-triphenylmethyl andrographolide (RS-PP-050), an andrographolide analogue and determine its activity in the Wnt/β-catenin pathway. RS-PP-050 was found to potently inhibit the proliferation and survival of HT-29 CRC cells. It induces cell cycle arrest and promotes apoptotic cell death which was associated with the activation of PARP-1 and p53. Furthermore, RS-PP-050 exerts inhibitory effects on β-catenin transcription by suppressing T-cell factor/lymphocyte enhancer factor (TCF/LEF) activity in cells overexpressing β-catenin and by down-regulating the endogenous expression of Wnt target genes. RS-PP-050 also decreased the protein expression of the active form of β-catenin but functions independently of GSK-3β, a negative regulator of Wnt. Interestingly, RS-PP-050 extensively blocks phosphorylation at Ser675 of β-catenin which links to interference of the nuclear translocation of β-catenin and might contribute to Wnt inactivation. Collectively, our findings reveal the underlying anti-cancer mechanism of an andrographolide analogue and provide useful insight for exploiting a newly chemotherapeutic agent in Wnt/β-catenin-overexpressing CRC cells.

The GSK3β inhibitor BIS I reverts YAP-dependent EMT signature in PDAC cell lines by decreasing SMADs expression level

The Yes-associated protein, YAP, is a transcriptional co-activator, mediating the Epithelial to Mesenchymal Transition program in pancreatic ductal adenocarcinoma (PDAC). With the aim to identify compounds that can specifically modulate YAP functionality in PDAC cell lines, we performed a small scale, drug-based screening experiment using YAP cell localization as the read-out. We identified erlotinib as an inducer of YAP cytoplasmic localization, an inhibitor of the TEA luciferase reporter system and the expression of the bona fide YAP target gene, Connective Tissue Growth Factor CTGF. On the other hand, BIS I, an inhibitor of PKCδ and GSK3β, caused YAP accumulation into the nucleus. Activation of β-catenin reporter and interfering experiments show that inhibition of the PKCδ/GSK3β pathway triggers YAP nuclear accumulation inducing YAP/TEAD transcriptional response. Inhibition of GSK3β by BIS I reduced the expression levels of SMADs protein and reduced YAP contribution to EMT. Notably, BIS I reduced proliferation, migration and clonogenicity of PDAC cells in vitro, phenocopying YAP genetic down-regulation. As shown by chromatin immunoprecipitation experiments and YAP over-expressing rescue experiments, BIS I reverted YAP-dependent EMT program by modulating the expression of the YAP target genes E-cadherin, vimentin, CTGF and of the newly identified target, CD133. In conclusion, we identified two different molecules, erlotinib and BIS I, modulating YAP functionality although via different mechanisms of action, with the second one specifically inhibiting the YAP-dependent EMT program in PDAC cell lines.

Diet and Exercise: a Match Made in Bone

PURPOSE OF REVIEW

Multiple dietary components have the potential to positively affect bone mineral density in early life and reduce loss of bone mass with aging. In addition, regular weight-bearing physical activity has a strong positive effect on bone through activation of osteocyte signaling. We will explore possible synergistic effects of dietary components and mechanical stimuli for bone health by identifying dietary components that have the potential to alter the response of osteocytes to mechanical loading.

RECENT FINDINGS

Several (sub)cellular aspects of osteocytes determine their signaling towards osteoblasts and osteoclasts in response to mechanical stimuli, such as the osteocyte cytoskeleton, estrogen receptor α, the vitamin D receptor, and the architecture of the lacunocanalicular system. Potential modulators of these features include 1,25-dihydroxy vitamin D3, several forms of vitamin K, and the phytoestrogen genistein. Multiple dietary components potentially affect osteocyte function and therefore may have a synergistic effect on bone health when combined with a regime of physical activity.

TIEG1 modulates β-catenin sub-cellular localization and enhances Wnt signaling in bone

We have previously demonstrated that TGFβ Inducible Early Gene-1 (TIEG1), also known as KLF10, plays important roles in mediating skeletal development and homeostasis in mice. TIEG1 has also been identified in clinical studies as one of a handful of genes whose altered expression levels or allelic variations are associated with decreased bone mass and osteoporosis in humans. Here, we provide evidence for the first time that TIEG1 is involved in regulating the canonical Wnt signaling pathway in bone through multiple mechanisms of action. Decreased Wnt signaling in the absence of TIEG1 expression is shown to be in part due to impaired β-catenin nuclear localization resulting from alterations in the activity of AKT and GSK-3β. We also provide evidence that TIEG1 interacts with, and serves as a transcriptional co-activator for, Lef1 and β-catenin. Changes in Wnt signaling in the setting of altered TIEG1 expression and/or activity may in part explain the observed osteopenic phenotype of TIEG1 KO mice as well as the known links between TIEG1 expression levels/allelic variations and patients with osteoporosis.

Osteoporosis and ageing affects the migration of stem cells and this is ameliorated by transfection with CXCR4

OBJECTIVES

Cellular movement and relocalisation are important for many physiologic properties. Local mesenchymal stem cells (MSCs) from injured tissues and circulating MSCs aid in fracture healing. Cytokines and chemokines such as Stromal cell-derived factor 1(SDF-1) and its receptor chemokine receptor type 4 (CXCR4) play important roles in maintaining mobilisation, trafficking and homing of stem cells from bone marrow to the site of injury. We investigated the differences in migration of MSCs from the femurs of young, adult and ovariectomised (OVX) rats and the effect of CXCR4 over-expression on their migration.

METHODS

MSCs from young, adult and OVX rats were put in a Boyden chamber to establish their migration towards SDF-1. This was compared with MSCs transfected with CXCR4, as well as MSCs differentiated to osteoblasts.

RESULTS

MSCs from OVX rats migrate significantly (p < 0.05) less towards SDF-1 (9%, sd 5%) compared with MSCs from adult (15%, sd 3%) and young rats (25%, sd 4%). Cells transfected with CXCR4 migrated significantly more towards SDF-1 compared with non-transfected cells, irrespective of whether these cells were from OVX (26.5%, sd 4%), young (47%, sd 17%) or adult (21%, sd 4%) rats. Transfected MSCs differentiated to osteoblasts express CXCR4 but do not migrate towards SDF-1.

CONCLUSIONS

MSC migration is impaired by age and osteoporosis in rats, and this may be associated with a significant reduction in bone formation in osteoporotic patients. The migration of stem cells can be ameliorated by upregulating CXCR4 levels which could possibly enhance fracture healing in osteoporotic patients.Cite this article: A. Sanghani-Kerai, M. Coathup, S. Samazideh, P. Kalia, L. Di Silvio, B. Idowu, G. Blunn. Osteoporosis and ageing affects the migration of stem cells and this is ameliorated by transfection with CXCR4. Bone Joint Res 2017;6:-365. DOI: 10.1302/2046-3758.66.BJR-2016-0259.R1.

Simple assay for screening phytoestrogenic compounds using the oestrogen receptor immobilised magnetite nanoparticles

With increasing interests of phytoestrogens for their potential applications, a rapid and simple tool for screening these phytochemicals is still required. In this study, a simple assay to detect phytoestrogens was developed based on the competition binding between the tested samples and the fluorescently labelled oestrogen (E2) to the human ligand binding domain of oestrogen receptor (LBD-ER) that was immobilised on the magnetite nanoparticles (MNPs). The 40-kDa LBD-ER peptide was produced in an Escherichia coli system. The synthesised 68.7-nm MNPs were silanised and subsequently covalently linked to the C-terminus of LBD-ER peptide. The LBD-ER immobilised MNPs demonstrated the specific binding for the standard E2 with the equilibrium dissociation constant of 9.56 nM and the binding capacity of 0.08 pmol/1 mg of the MNPs. The LBD-ER immobilised MNPs could evaluate oestrogenic activity of the extracts of Asparagus racemosus and Curcuma comosa, the reported phytoestrogenic plants, but not progesterone (P4) and Raphanus sativus extract, the negative controls. The results of this work clearly demonstrated a potential assay for detecting phytoestrogens of crude plant extracts, which is simple and easily adapted to a high throughput format.

Selective Estrogen Receptor Modulator (SERM)-like Activities of Diarylheptanoid, a Phytoestrogen from Curcuma comosa, in Breast Cancer Cells, Pre-osteoblast Cells, and Rat Uterine Tissues

Diarylheptanoids from Curcuma comosa, of the Zingiberaceae family, exhibit diverse estrogenic activities. In this study we investigated the estrogenic activity of a major hydroxyl diarylheptanoid, 7-(3,4 -dihydroxyphenyl)-5-hydroxy-1-phenyl-(1E)-1-heptene (compound 092) isolated from C. comosa. The compound elicited different transcriptional activities of estrogen agonist at low concentrations (0.1-1 μM) and antagonist at high concentrations (10-50 μM) using luciferase reporter gene assay in HEK-293T cells. In human breast cancer (MCF-7) cells, compound 092 showed an anti-estrogenic activity by down-regulating ERα-signaling and suppressing estrogen-responsive genes, whereas it attenuated the uterotrophic effect of estrogen in immature ovariectomized rats. Of note, compound 092 promoted mouse pre-osteoblastic (MC3T3-E1) cell differentiation and the related bone markers, indicating its positive osteogenic effect. Our findings highlight a new, nonsteroidal, estrogen agonist/antagonist of catechol diarylheptanoid from C. comosa, which is scientific evidence supporting its potential as a dietary supplement to prevent bone loss with low risk of breast and uterine cancers in postmenopausal women.

Serum lipidomics analysis of ovariectomized rats under Curcuma comosa treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Curcuma comosa Roxb. (C. comosa) or Wan Chak Motluk, Zingiberaceae family, has been used in Thai traditional medicine for the treatment of gynecological problems and inflammation.

AIM OF THE STUDY

This study aimed to investigate the therapeutic potential of C. comosa by determining the changes in the lipid profiles in the ovariectomized rats, as a model of estrogen-deficiency-induced hyperlipidemia, after treatment with different components of C. comosa using an untargeted lipidomics approach.

MATERIALS AND METHODS

Lipids were extracted from the serum of adult female rats subjected to a sham operation (SHAM; control), ovariectomy (OVX), or OVX with 12-week daily doses of estrogen (17β-estradiol; E₂), (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol (DPHD; a phytoestrogen from C. comosa), powdered C. comosa rhizomes or its crude ethanol extract. They were then analyzed by liquid chromatography-mass spectrometry, characterized, and subjected to the orthogonal projections to latent structures discriminant analysis statistical model to identify tentative biomarkers.

RESULTS

Levels of five classes of lipids (ceramide, ceramide-1-phosphate, sphingomyelin, 1-O-alkenyl-lysophosphatidylethanolamine and lysophosphatidylethanolamine) were elevated in the OVX rats compared to those in the SHAM rats, while the monoacylglycerols and triacylglycerols were decreased. The E₂ treatment only reversed the levels of ceramides, whereas treatments with DPHD, C. comosa extract or powder returned the levels of all upregulated lipids back to those in the SHAM control rats.

CONCLUSIONS

The findings suggest the potential beneficial effects of C. comosa on preventing the increased ceramide levels in OVX rats, a possible cause of metabolic disturbance under estrogen deficiency. Overall, the results demonstrated the power of untargeted lipidomics in discovering disease-relevant biomarkers, as well as evaluating the effectiveness of treatment by C. comosa components (DPHD, extract or powder) as utilized in Thai traditional medicine, and also providing scientific support for its folklore use.

5-Acetyl goniothalamin suppresses proliferation of breast cancer cells via Wnt/β-catenin signaling

Styryl lactones are plant-derived compounds from genus Goniothalamus with promising anti-proliferation and anticancer properties. However, the exact mechanism and the target for their activities remained unclear. In the present study, we investigated the effect of 5-acetyl goniothalamin (5GTN) from Goniothalamus marcanii on Wnt/β-catenin signaling pathway which is a key regulator in controlling cell proliferation in breast cancer cells (MCF-7 and MDA-MB-231). 5GTN, a naturally occurring derivative of goniothalamin (GTN) mediated the toxicity to MCF-7 and MDA-MB-231 cells in a dose- and time- related manner, and was more potent than that of GTN. 5GTN strongly inhibited cell proliferation and markedly suppressed transcriptional activity induced by β-catenin in luciferase reporter gene assay. In consistent with this view, the expression of Wnt/β-catenin signaling target genes including c-Myc, cyclin D1 and Axin2 in MCF-7 and MDA-MB-231 cells were suppressed after treatment with 5GTN. It was concomitant with cell cycle arrest at G₁ phase and cell apoptosis in MCF-7 cells. In addition, 5GTN enhanced glycogen synthase kinase (GSK-3β) activity and therefore reduced the expression of active form of β-catenin protein in MCF-7 and MDA-MB-231 cells. Taken together, 5GTN exhibited a promising anticancer effect against breast cancer cells through an inhibition of Wnt/β-catenin signaling. This pathway may be served as a potential chemotherapeutic target for breast cancer by 5GTN.

Chronic over-nutrition and dysregulation of GSK3 in diseases

Loss of cellular response to hormonal regulation in maintaining metabolic homeostasis is common in the process of aging. Chronic over-nutrition may render cells insensitive to such a hormonal regulation owing to overstimulation of certain signaling pathways, thus accelerating aging and causing diseases. The glycogen synthase kinase 3 (GSK3) plays a pivotal role in relaying various extracellular and intracellular regulatory signals critical to cell growth, survival, regeneration, or death. The main signaling pathway regulating GSK3 activity through serine-phosphorylation is the phosphoinositide 3-kinase (PI3K)/phosphoinositide-dependent kinase-1 (PDK1)/Akt relay that catalyzes serine-phosphorylation and thus inactivation of GSK3. In addition, perilipin 2 (PLIN2) has recently been shown to regulate GSK3 activation through direct association with GSK3. This review summarizes current understanding on environmental and nutritional factors contributing to GSK3 regulation (or dysregulation) through the PI3K/PDK1/Akt/GSK3 axis, and highlights the newly discovered role that PLIN2 plays in regulating GSK3 activity and GSK3 downstream pathways.

Estrogen enhances activity of Wnt signaling during osteogenesis by inducing Fhl1 expression

Estrogen is a crucial hormone for osteoclast inhibition and for preventing osteoporosis. However, the hormone's role in osteoblast growth and differentiation remains unclear. The complexity of estrogen's role in guiding osteoblast behavior arises partly from crosstalk with other signaling pathways, including Wnt signaling. In this study, we show that the Wnt agonist, LiCl, induced Fhl1 gene expression, which substantially enhanced osteoblast differentiation. Staining with alizarin red revealed that MC3T3-E1 mineralization was enhanced by overexpression of Fhl1. In addition, Fhl1 promoted the expression of the osteogenic markers, Runt-related transcription factor 2 (Runx2), osteocalcin (OCN), and osteopontin (OPN), whereas MC3T3-E1 cells with gene knockdown of Fhl1 exhibited limited mineralization and expression of Runx2, OCN, and OPN. We further demonstrate evidences from quantitative reverse transcription real-time polymerase chain reaction and reporter assay that Fhl1 expression was synergistically stimulated by estrogen (E2) and LiCl, but reduced by the estrogen-receptor inhibitor fulvestrant (ICI 182,780). However, estrogen could not enhance osteogenesis while Fhl1 expression was knocked down. Because estrogen and Wnt signaling frequently interact in developmental processes, we propose that Fhl1 can be an acting molecule mediating both signaling pathways during osteogenesis.

Pharmaceutical inhibition of glycogen synthetase kinase 3 beta suppresses wear debris-induced osteolysis

Aseptic loosening is associated with the development of wear debris-induced peri-implant osteolytic bone disease caused by an increased osteoclastic bone resorption and decreased osteoblastic bone formation. However, no effective measures for the prevention and treatment of peri-implant osteolysis currently exist. The aim of this study was to determine whether lithium chloride (LiCl), a selective inhibitor of glycogen synthetase kinase 3 beta (GSK-3β), mitigates wear debris-induced osteolysis in a murine calvarial model of osteolysis. GSK-3β is activated by titanium (Ti) particles, and implantation of Ti particles on the calvarial surface in C57BL/6 mice resulted in osteolysis caused by an increase in the number of osteoclasts and a decrease in the number of osteoblasts. Mice implanted with Ti particles were gavage-fed LiCl (50 or 200 mg kg(-1)d(-1)), 6 days per week for 2 weeks. The LiCl treatment significantly inhibited GSK-3β activity and increased β-catenin and axin-2 expression in a dose-dependent manner, dramatically mitigating the Ti particle-induced suppression of osteoblast numbers and the expression of bone formation markers. Finally, we demonstrated that inhibition of GSK-3β suppresses osteoclast differentiation and reduces the severity of Ti particle-induced osteolysis. The results of this study indicate that Ti particle-induced osteolysis is partly dependent on GSK-3β and, therefore, the canonical Wnt signaling pathway. This suggests that selective inhibitors of GSK-3β such as LiCl may help prevent and treat wear debris-induced osteolysis.

Estrogen Modulates Bone Morphogenetic Protein-Induced Sclerostin Expression Through the Wnt Signaling Pathway

Clinical data show that estrogen levels are inversely associated with the production of sclerostin, a Wnt antagonist that recently attracted great attention over the use of its antibody in the anabolic treatment of osteoporotic conditions. However, the molecular link between sclerostin expression and estrogen signaling is not yet known. We investigated the mechanisms by which estrogen modulates sclerostin (SOST) gene expression at the cellular level in human osteoblast cells in association with bone morphogenetic protein (BMP)2 signaling given that BMP2 is a potential inducer of SOST in human mesenchymal stromal cells (hMSCs). 17β-Estradiol (E2) alone had no effect on SOST expression, which was significantly induced by treatment with BMP2 in hMSCs and osteoblasts derived from the mandibles of female donors. However, E2 suppressed the induction of SOST and other BMP2 target genes by BMP2 in hMSCs. E2 signaling was independent of the Smad pathway, which plays a critical role in SOST induction mediated by BMP2. Instead, E2 increased the transcriptional expression of β-catenin and levels of its activated form. Silencing of the gene encoding estrogen receptor (ER)α decreased E2 activity in β-catenin activation and the suppression of SOST induction by BMP2, but had no influence on BMP2-mediated SOST induction in the same conditions. Similar results were obtained after treatment with ERα antagonist as a Wnt inhibitor. In human osteoblasts, the effect of E2 on SOST expression was either suppressive or absent, depending on the cell donor. Interestingly, the SOST expression pattern after treatment with BMP2 or BMP2/E2 in human osteoblasts showing a pattern of E2 suppression on SOST induction by BMP2 correlated with the ratio of receptor activator of nuclear factor kappa-B ligand (RANKL) to osteoprotegerin (OPG) expression. These results demonstrate that estrogen signaling in osteoblasts negatively regulates SOST expression in an indirect manner through interaction with BMP2 signaling and that this regulation involves the Wnt/ERα and β-catenin pathways. This study highlights several interactions between estrogen and BMP cascades in osteoblasts that may provide a basis for therapeutic intervention for the modification of bone mass density.

Apigenin Inhibits Growth of Breast Cancer Cells: The Role of ERα and HER2/neu

Phytoestrogens are a group of plant-derived compounds with an estrogen-like activity. In mammalians, phytoestrogens bind to the estrogen receptor (ER) and participate in the regulation of cell growth and gene transcription. There are several reports of the cytotoxic effects of phytoestrogens in different cancer cell lines. The aim of this study was to measure the phytoestrogen activity against breast cancer cells with different levels of ER expression and to elucidate the molecular pathways regulated by the leader compound. Methods used in the study include immunoblotting, transfection with a luciferase reporter vector, and a MTT test. We demonstrated the absence of a significant difference between ER+ and ER- breast cancer cell lines in their response to cytotoxic stimuli: treatment with high doses of phytoestrogens (apigenin, genistein, quercetin, naringenin) had the same efficiency in ER-positive and ER-negative cells. Incubation of breast cancer cells with apigenin revealed the highest cytotoxicity of this compound; on the contrary, naringenin treatment resulted in a low cytotoxic activity. It was shown that high doses of apigenin (50 μM) do not display estrogen-like activity and can suppress ER activation by 17β-estradiol. Cultivation of HER2-positive breast cancer SKBR3 cells in the presence of apigenin resulted in a decrease in HER2/neu expression, accompanied by cleavage of an apoptosis substrate PARP. Therefore, the cytotoxic effects of phytoestrogens are not associated with the steroid receptors of breast cancer cells. Apigenin was found to be the most effective phytoestrogen that strongly inhibits the growth of breast cancer cells, including HER2-positive ones.

The impact of low-magnitude high-frequency vibration on fracture healing is profoundly influenced by the oestrogen status in mice

Fracture healing is impaired in aged and osteoporotic individuals. Because adequate mechanical stimuli are able to increase bone formation, one therapeutical approach to treat poorly healing fractures could be the application of whole-body vibration, including low-magnitude high-frequency vibration (LMHFV). We investigated the effects of LMHFV on fracture healing in aged osteoporotic mice. Female C57BL/6NCrl mice (n=96) were either ovariectomised (OVX) or sham operated (non-OVX) at age 41 weeks. When aged to 49 weeks, all mice received a femur osteotomy that was stabilised using an external fixator. The mice received whole-body vibrations (20 minutes/day) with 0.3 G: peak-to-peak acceleration and a frequency of 45 Hz. After 10 and 21 days, the osteotomised femurs and intact bones (contra-lateral femurs, lumbar spine) were evaluated using bending-testing, micro-computed tomography (μCT), histology and gene expression analyses. LMHFV disturbed fracture healing in aged non-OVX mice, with significantly reduced flexural rigidity (-81%) and bone formation (-80%) in the callus. Gene expression analyses demonstrated increased oestrogen receptor β (ERβ, encoded by Esr2) and Sost expression in the callus of the vibrated animals, but decreased β-catenin, suggesting that ERβ might mediate these negative effects through inhibition of osteoanabolic Wnt/β-catenin signalling. In contrast, in OVX mice, LMHFV significantly improved callus properties, with increased flexural rigidity (+1398%) and bone formation (+637%), which could be abolished by subcutaneous oestrogen application (0.025 mg oestrogen administered in a 90-day-release pellet). On a molecular level, we found an upregulation of ERα in the callus of the vibrated OVX mice, whereas ERβ was unaffected, indicating that ERα might mediate the osteoanabolic response. Our results indicate a major role for oestrogen in the mechanostimulation of fracture healing and imply that LMHFV might only be safe and effective in confined target populations.

Phytoestrogens as alternative hormone replacement therapy in menopause: What is real, what is unknown

Menopause is characterized by an altered hormonal status and by a decrease in life quality due to the appearance of uncomfortable symptoms. Nowadays, with increasing life span, women spend one-third of their lifetime under menopause. Understanding menopause-associated pathophysiology and developing new strategies to improve the treatment of menopausal-associated symptoms is an important topic in the clinic. This review describes physiological and hormone alterations observed during menopause and therapeutic strategies used during this period. We critically address the benefits and doubts associated with estrogen/progesterone-based hormone replacement therapy (HRT) and discuss the use of phytoestrogens (PEs) as a possible alternative. These relevant plant-derived compounds have structural similarities to estradiol, interacting with cell proteins and organelles, presenting several advantages and disadvantages versus traditional HRT in the context of menopause. However, a better assessment of PEs safety/efficacy would warrant a possible widespread clinical use.

Attenuation of Aβ25-35-induced parallel autophagic and apoptotic cell death by gypenoside XVII through the estrogen receptor-dependent activation of Nrf2/ARE pathways

Amyloid-beta (Aβ) has a pivotal function in the pathogenesis of Alzheimer's disease. To investigate Aβ neurotoxicity, we used an in vitro model that involves Aβ25-35-induced cell death in the nerve growth factor-induced differentiation of PC12 cells. Aβ25-35 (20μM) treatment for 24h caused apoptotic cell death, as evidenced by significant cell viability reduction, LDH release, phosphatidylserine externalization, mitochondrial membrane potential disruption, cytochrome c release, caspase-3 activation, PARP cleavage, and DNA fragmentation in PC12 cells. Aβ25-35 treatment led to autophagic cell death, as evidenced by augmented GFP-LC3 puncta, conversion of LC3-I to LC3-II, and increased LC3-II/LC3-I ratio. Aβ25-35 treatment induced oxidative stress, as evidenced by intracellular ROS accumulation and increased production of mitochondrial superoxide, malondialdehyde, protein carbonyl, and 8-OHdG. Phytoestrogens have been proved to be protective against Aβ-induced neurotoxicity and regarded as relatively safe targets for AD drug development. Gypenoside XVII (GP-17) is a novel phytoestrogen isolated from Gynostemma pentaphyllum or Panax notoginseng. Pretreatment with GP-17 (10μM) for 12h increased estrogen response element reporter activity, activated PI3K/Akt pathways, inhibited GSK-3β, induced Nrf2 nuclear translocation, augmented antioxidant responsive element enhancer activity, upregulated heme oxygenase 1 (HO-1) expression and activity, and provided protective effects against Aβ25-35-induced neurotoxicity, including oxidative stress, apoptosis, and autophagic cell death. In conclusion, GP-17 conferred protection against Aβ25-35-induced neurotoxicity through estrogen receptor-dependent activation of PI3K/Akt pathways, inactivation of GSK-3β and activation of Nrf2/ARE/HO-1 pathways. This finding might provide novel insights into understanding the mechanism for neuroprotective effects of phytoestrogens or gypenosides.

Supplementing with Opuntia ficus-indica Mill and Dioscorea nipponica Makino extracts synergistically attenuates menopausal symptoms in estrogen-deficient rats

ETHNOPHARMACOLOGICAL RELEVANCE

Prickly pear cactus grown in Korea (Opuntia ficus-indica Mill, KC) and Buchema (Dioscorea nipponica Makino, B) have been traditionally used in East Asia and South America to treat various metabolic diseases. The aim of the present study was to determine whether the extracts of KC, B, and KC+B can prevent the impairments of energy, glucose, lipid and bone homeostasis in estrogen-deficient ovariectomized (OVX) rats and to explore their mechanisms.

MATERIALS AND METHODS

OVX rats were divided into 4 groups and fed high fat diets supplemented with either 3% dextrin (control), 3% KC, 3% B or 1.5% KC+1.5% B. Sham rats were fed 3% dextrin. After 12 weeks of diet consumption, energy, lipid, glucose and bone metabolisms were analyzed and Wnt signaling in the femur and hepatic signaling were determined.

RESULTS

OVX impaired energy, glucose and lipid metabolism and decreased uterine and bone masses. B and KC+B prevented the decrease in energy expenditure, especially from fat oxidation, in OVX rats, but did not affect food intake. KC+B and B reduced body weight and visceral fat levels, as compared to the OVX-control, by decreasing fat synthesis and inhibiting FAS and SREBP-1c expression. KC+B and B prevented the increases in serum lipid levels and insulin resistance by improving hepatic insulin signaling (pIRS→pAkt→pGSK-3β). KC and KC+B also prevented decreases in bone mineral density (BMD) in the femur and lumbar spine in OVX rats. This was related to decreased expressions of bone turnover markers such as serum osteocalcin, alkaline phosphatase (ALP) and bone-specific ALP levels, and increased serum P levels. KC and KC+B upregulated low-density lipoprotein receptor-related protein 5 and β-catenin in OVX rats, but suppressed the expression of dickkopf-related protein 1. B alone improved energy, lipid and glucose homeostasis, but not bone loss, whereas KC alone enhanced BMD, but not energy, lipid or glucose homeostasis.

CONCLUSION

KC+B synergistically attenuated impairments of bone, energy, lipid and glucose metabolism by OVX, suggesting potential efficacy of the combination for alleviating menopausal symptoms.

Huogu I formula prevents steroid-induced osteonecrosis in rats by down-regulating PPARgamma expression and activating wnt/LRP5/ beta-catenin signaling

OBJECTIVE

To investigate the effects of Huogu I formula on regulation of lipid metabolism in steroid-induced osteonecrosis of the femoral head (SONFH) rats and verify our hypothesis that Huogu I formula regulates lipid metabolism by down-regulating peroxisome proliferator-activated receptor gamma (PPARgamma) expression and activating Wnt signaling pathways.

METHODS

Eighty-five rats were divided into four groups: control, model, Huogu 15 g/kg and Huogu 30 g/kg. Six weeks later, animals were anaesthetized, femora was dissected for histopathological examination of the osteonecrotic changes and repair processes, micro computed tomography (Micro-CT)-based micro-angiography was performed to assess vascularization. Serum lipid levels were detected by haematological examination. The expressions of PPARy, Wnt3a, low density lipoprotein receptor-related protein 5 (LRP5) and beta-catenin were evaluated by immunohistochemistry, Western blot and quantitative real-time polymerase chain reaction analyses.

RESULTS

The incidence of osteonecrosis, ratio of empty lacuna, adipose tissue area and adipocyte perimeter in the bone marrow were dramatically lower in the Huogu I formula treatment groups. By micro-CT quantification, Huogu I formula treatment dose-dependently increased vessel volume, vessel surface, percentage of vessel volume and vessel thickness of the femoral heads of SONFH rats. Levels of serum lipid in Huogu 15 g/kg and Huogu 30 g/kg groups reduced significantly. Huogu I formula treatment could suppress the expression of PPARy and increase the expressions of Wnt3a, LRP5 and beta-catenin at both protein and mRNA levels.

CONCLUSION

The results of our present study highlight the lipid-lowering potential of Huogu I formula, and provide further evidence of the involvement of the PPARgamma inhibition and Wnt/LRP5/ beta-catenin signaling activation in the effects of Huogu I formula.

Inactivation of glycogen synthase kinase-3β up-regulates β-catenin and promotes chondrogenesis

This study aimed to investigate whether inhibition of glycogen synthase kinase-3β (GSK-3β) could promote chondrocytes proliferation. The expression pattern of GSK-3β was firstly determined by immunohistochemistry (IHC) in normal mouse. Tibias were then isolated and cultured for 6 days. The tibias were treated with dimethylsulfoxide (control) or GSK-3 inhibitor SB415286 (SB86). Length of tibias was measured until 6 days after treatment. These bones were either stained with alcian blue/alizarin red or analyzed by IHC. In addition, GSK-3β and β-catenin were analyzed by Western blot. Finally, cartilage-specific GSK-3β deletion mice (KO) were generated. Efficiency of GSK-3β deletion was determined through Western blot and IHC. After treated by inhibitor SB86, the overall length of growth plate was not changed. However, growth of tibia in SB86 group was increased by 31 %, the length of resting and proliferating was increased 13 % (P < 0.01), whereas the length of hypertrophic was decreased by 57 % (P < 0.01). Besides, the mineralized length was found to be significant longer than the control group (P < 0.05). In KO mice, growth plate and calvaria tissue both exhibit significant reduction of GSK-3β (P < 0.05) whereas the lengths of tibias in KO were almost same compared with control mice. Finally, an increase amount of β-catenin protein was observed in SB86 (P < 0.05). In addition, significantly increased β-catenin was also found in the growth plate of KO mice (P < 0.05). Inhibition of GSK-3 could promote longitudinal growth of bone through increasing bone formation. Besides, the inactivation of GSK-3β could lead to enhancing β-catenin, therefore promote chondrocytes proliferation.

Estrogen improves the proliferation and differentiation of hBMSCs derived from postmenopausal osteoporosis through notch signaling pathway

Estrogen deficiency is the main reason of bone loss, leading to postmenopausal osteoporosis, and estrogen replacement therapy (ERT) has been demonstrated to protect bone loss efficiently. Notch signaling controls proliferation and differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Moreover, imperfect estrogen-responsive elements (EREs) were found in the 5'-untranslated region of Notch1 and Jagged1. Thus, we examined the molecular and biological links between estrogen and the Notch signaling in postmenopausal osteoporosis in vitro. hBMSCs were obtained from healthy women and patients with postmenopausal osteoporosis. Notch signaling molecules were quantified using real-time polymerase chain reaction (real-time PCR) and Western Blot. Luciferase reporter constructs with putative EREs were transfected into hBMSCs and analyzed. hBMSCs were transduced with lentiviral vectors containing human Notch1 intracellular domain (NICD1). We also used N-[N-(3, 5-diflurophenylacetate)-l-alanyl]-(S)-phenylglycine t-butyl ester, a γ-secretase inhibitor, to suppress the Notch signaling. We found that estrogen enhanced the Notch signaling in hBMSCs by promoting the expression of Jagged1. hBMSCs cultured with estrogen resulted in the up-regulation of Notch signaling and increased proliferation and differentiation. Enhanced Notch signaling could enhance the proliferation and differentiation of hBMSCs from patients with postmenopausal osteoporosis (OP-hBMSCs). Our results demonstrated that estrogen preserved bone mass partly by activating the Notch signaling. Because long-term ERT has been associated with several side effects, the Notch signaling could be a potential target for treating postmenopausal osteoporosis.

Involvement of estrogen in gastric cancer cell invasion regulated by tunicamycin induced-endoplasmic reticulum stress

AIM: To investigate the involvement of estrogen in gastric cancer cell invasion regulated by tunicamycin (TM) induced-endoplasmic reticulum stress and to explore the possible mechanism involved.

METHODS: TM (3 μmol/L) alone or in combination with 17β-estradiol (E2, 10-9 mol/L) was incubated with SGC7901 cells for 24 h, with the same concentrations of DMSO and alcohol used as vehicle controls. After treatment, the invasion of gastric cancer cells was evaluated by Transwell chamber assays. The expression of phosphorylated protein kinase RNA-like endoplasmic reticulum kinase (pPERK) and phosphorylated glycogen synthase kinase-3β (GSK-3β) at Ser9 were examined by Western blot analysis.

RESULTS: TM induced-endoplasmic reticulum stress, which was demonstrated by increased pPERK, decreased the invasion ability of gastric cancer SGC7901 cells and the phosphorylation of GSK-3β at Ser9. However, simultaneous treatment with E2 increased the invasion of gastric cancer cells by counteracting the activating effect of TM on GSK-3β, causing an increase in the phosphorylation of Ser9-GSK-3β.

CONCLUSION: Estrogen may counteract endoplasmic reticulum stress-induced activation of GSK-3β and increase the invasion of gastric cancer cells.

Dioscin promotes osteoblastic proliferation and differentiation via Lrp5 and ER pathway in mouse and human osteoblast-like cell lines

Background

Dioscin, a typical steroid saponin, is isolated from Dioscorea nipponica Makino and Dioscorea zingiberensis Wright. It has estrogenic activity and many studies have also reported that dioscorea plants have an effect in preventing and treating osteoporosis. However, the molecular mechanisms underlying their effect on osteoporosis treatment are poorly understood. Therefore, the present study aims to investigate the mechanism (s) by which dioscin promotes osteoblastic proliferation and differentiation in mouse pre-osteoblast like MC3T3-E1 cells and human osteoblast-like MG-63 cells.

Results

We found that dioscin (0.25 μg/ml, 0.5 μg/ml, and 1.0 μg/ml) promoted MC3T3-E1 cells and MG-63 cells proliferation and differentiation dose dependently. Western blot analysis results showed that estrogen receptor α (ER-α), estrogen receptor β (ER-β), β-catenin and Bcl-2 protein expression increased after MC3T3-E1 cells were treated with dioscin. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that dioscin could increase the ratio of osteoprotegerin (OPG)/receptor activator of NF-κB ligand (RANKL) and up-regulate the level of Lrp5 and β-catenin. And by RNA interference analysis, we proved that the effect of dioscin increasing the ratio of OPG/RANKL was dependent on Lrp5 pathway. In addition, we also found that these effects of dioscin were abolished by ICI 182, 780 (100 nM), an antagonist of ER, indicating that an ER signaling pathway was also involved. We also found that dioscin (0.25 μg/ml, 0.5 μg/ml, and 1.0 μg/ml) induced MG-63 cells proliferation and differentiation in a dose-dependent manner. Western blot analysis results indicated that ER-α, ER-β and β-catenin protein expression increased after MG-63 cells were treated with dioscin.

Conclusions

The current study is the first to reveal that dioscin can promote osteoblasts proliferation and differentiation via Lrp5 and ER pathway.