Salidroside alleviates dexamethasone-induced inhibition of bone formation via transforming growth factor-beta/Smad2/3 signaling pathway.

Glucocorticoid-induced osteoporosis is the third epidemic osteoporosis following postmenopausal and senileosteoporosis. According to one study, salidroside made ovariectomized rats' bones strong. Salidroside's potential for treating glucocorticoid-induced osteoporosis remains unproven. This study aimed to investigate the protective effect and mechanism of salidroside on dexamethasone-induced osteogenic differentiation and bone formation in MC3T3-E1 cells and zebrafish. The study proved that salindroside had no harmful impact on MC3T3E1 cells. Salidroside significantly relieved dexamethasone-induced inhibition of ALP (alkaline phosphatase) activity and mineralization in MC3T3-E1 cells, and promoted osteogenic differentiation of cells. Salidroside increased the expression of osteopontin (OPN), runt-related transcription factor 2 (Runx2), osterix (Osx), transforming growth factor-beta (TGF-ß) proteins and promoted the phosphorylation of Smad2/3 in MC3T3-E1 cells treated with dexamethasone. In addition, the effect of salidroside in relieving dexamethasone-induced inhibition of osteogenic differentiation in MC3T3-E1 cells can be blocked by TGF-ß receptor type I/II inhibitor (LY2109761). At the same time, we found that salidroside significantly alleviated the inhibition of dexamethasone-induced bone formation in zebrafish and promoted the mineralization of zebrafish skulls. LY2109761 reversed the protective impact of salidroside on dexamethasone-mediated bone impairment in zebrafish. These findings suggested that salidroside alleviated dexamethasone-induced inhibition of osteogenic differentiation and bone formation via TGF-ß/Smad2/3 signaling pathway.

Cycloastragenol protects against glucocorticoid-induced osteogenic differentiation inhibition by activating telomerase.

Glucocorticoid-induced osteoporosis (GIOP) that is mainly featured as low bone density and increased risk of fracture is prone to occur with the administration of excessive glucocorticoids. Cycloastragenol (CAG) has been verified to be a small molecule that activates telomerase. Studied showed that up-regulated telomerase was associated with promoting osteogeneic differentiation, so we explored whether CAG could promote osteogenic differentiation to protect against GIOP and telomerase would be the target that CAG exerted its function. Our results demonstrated that CAG prominently increased the ALP activity, mineralization, mRNA of runt-related transcription factor 2, osteocalcin, osteopontin, collagen type I in both MC3T3-E1 cells and dexamethasone (DEX)-treated MC3T3-E1 cells. CAG up-regulated telomerase reverse transcriptase and the protective effect of CAG was blocked by telomerase inhibitor TMPyP4. Moreover, CAG improved bone mineralization in DEX-induced bone damage in a zebrafish larvea model. Therefore, the study showed that CAG could alleviate the osteogenic differentiation inhibition induced by DEX in vitro and in vivo, and CAG might be considered as a candidate drug for the treatment of GIOP.

Isolation, synthesis, and cytotoxicity evaluation of two impurities in nomegestrol acetate.

Nomegestrol acetate (NOMAc) is a synthetic progesterone analog and classified as a fourth-generation progestin. It has been approved in many countries for oral contraception, hormonal replacement therapy (HRT), and treatment of various gynecological disorders. There are several synthetic routes reported for the synthesis of NOMAc and they all share the very similar last three to five steps toward the conversion of 6-methylene to 6-methyl-6,7-unsaturated structure. Therefore the final product from different processing routes may have similar impurity profiles. In the analysis of NOMAc, we identified two impurities, impurity A (listed in EP 8.0) and impurity B (not specified in EP 8.0). Both impurities were further confirmed by synthesis. In addition, both impurities and NOMAc were evaluated for their in vitro cytotoxicities against L02 liver cells, mesenchymal stem cells, MCF-7 breast cancer cells, and C33A cervical cancer cells. These three analogs are not cytotoxic to the four cell lines at low concentrations (<20 µM). NOMAc and impurity A showed cytotoxicity to L02, MCF-7, and C33A cells at high concentrations, while impurity B did not show significant cytotoxicity to any of the cell lines tested.

Biological activity and health promoting effects of psoralidin.

Psoralidin, a prenylated coumestrol isolated from the seed of a traditional Chinese medicine Psoralea corylifolia L., has been demonstrated to exhibit anti-inflammatory, anti-cancer, anti-oxidative, estrogenic, neuroprotective, anti-bacterial, and anti-parasite activities. Due to prenylation, psoralidin exhibits stronger estrogenic activity with no obvious adverse effects and shows a close association with management of osteoporosis and some cancers. However, the hydrophobicity and low bioavailability of psoralidin limit its clinical application, although recent investigation has gained valuable data. This review will discuss the biological activities of psoralidin in health.

[Systematic review of Shenqi Fuzheng Injection combined with chemotherapy for treatment of breast cancer].

Databases including China Biological Medicine database(CBM), Chinese scientific journals full-text database(VIP), China National Knowledge Infrastructure database(CNKI), WanFang Data, PubMed, and EMbase were searched from inception to March 2018 to collect the randomized controlled trials(RCTs) on Shenqi Fuzheng Injection combined with chemotherapy for the treatment of breast cancer. All included studies were critically appraised by two independent reviewers by following the cochrane systematic review method and using Revman 5.3 software and State 12.0 for data analysis. After screening, 20 RCTs involving 2 095 patients were included in the study. Meta-analysis showed that as compared with control group of chemotherapy alone, Shenqi Fuzheng Injection combined with chemotherapy could improve the clinical curative efficiency, the KPS score, and immune function indexes such as total T cells, Th cells and Ts cells; inhibit the decline of white blood cells(WBC), platelets in blood system, T-lymphocyte subsets such as CD3~+, CD4~+, CD4~+/CD8~+, alleviate myelosuppression and reduce the incidence of side effects such as gastrointestinal adverse reaction, liver and kidney dysfunction and abnormal electrocardiogram. The results revealed that for clinical breast cancer patients, Shenqi Fuzheng Injection combined with chemotherapy could significantly improve its clinical efficacy and reduce adverse reactions. However, the conclusions still need to be verified by high-quality, multi-center, large-sample, prospective, randomized and double-blind clinical trials. In conclusion, this study has systemically evaluated the efficacy and safety of Shenqi Fuzheng Injection combined with chemotherapy in treatment of breast cancer and provided the reference of evidence-based medicine for safe and effective clinical application of medicines.

5,7,3',4'-Tetramethoxyflavone protects chondrocytes from ER stress-induced apoptosis through regulation of the IRE1α pathway.

AIM OF THE STUDY: To investigate the roles of endoplasmic reticulum (ER) transmembrane sensor inositol-requiring enzyme-1 (IRE1)α signaling in ER stress-induced chondrocyte apoptosis, and to determine the molecular mechanisms underlying chondroprotective activity of 5,7,3',4'-tetramethoxyflavone (TMF) from Murraya exotica. MATERIALS AND METHODS: IRE1α was knocked down by siRNA transfection in chondrocytes, which were harvested from rats' knee cartilages. Chondrocytes with IRE1α deficiency were administrated with tunicamycin (TM) and TMF. Chondrocyte apoptosis was quantified by flow cytometry and DAPI/TUNEL staining. Expression of mRNA and proteins was quantified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western-blot, respectively. RESULTS: IRE1α deficiency significantly increased the rate of TM-induced chondrocyte apoptosis, down-regulated the expression of pro-survival factors XBP1S and Bcl-2, and up-regulated pro-apoptotic factors CHOP, p-JNK, and caspase-3. TMF suppressed TM-induced chondrocyte apoptosis by activating the expression of IRE1α, which reversed the expression patterns of downstream pro-survival and pro-apoptotic factors due to IRE1α deficiency. CONCLUSION: The mechanism of TMF in protecting chondrocytes against ER stress-induced apoptosis might be associated with regulating the activity of ER sensor IRE1α and its downstream pathway.

[Systematic review on efficacy and safety of Danshen Chuanxiongqin Injection in treatment of acute cerebral infarction].

To systemically evaluate the therapeutic efficacy and safety of Danshen Chuanxiongqin Injection in treatment of acute cerebral infarction and provide the reference of evidence-based medicine for its clinical safety and effective drug use. Databases including CNKI, WanFang Data, SinoMed, the Cochrane Library, EMbase and PubMed were searched from inception to April 2018 to collect the randomized controlled trials (RCTs) on Danshen Chuanxiongqin Injection in the treatment of acute cerebral infarction. The quality of all included studies was evaluated by two independent reviewers following the cochrane systematic review method and using Revman5.3 software and State13.0 for Meta-analysis. A total of 30 RCTs involving 3 233 patients with acute cerebral infarction were included in the study after literature quality evaluation. Meta-analysis showed that as compared with the control group of conventional western medicine alone, Danshen Chuanxiongqin Injection combined with conventional western medicine can achieve better efficacy in treatment of acute cerebral infarction, increase the clinical total effective rate (RR=1.22, 95% CI [1.18, 1.27], P<0.000 01) and activities of daily living (MD=9.42, 95% CI [8.12, 10.72], P<0.000 01), and improve the degree of neurological impairment (MD=-3.99, 95% CI [-4.89, -3.07], P<0.000 01). Furthermore, the result showed that Danshen Chuanxiongqin Injection in the treatment of acute cerebral infarction can significantly decrease the whole blood high-shear viscosity, whole blood low-shear viscosity, plasma viscosity, fibrinogen level and other hemorheological indexes (P<0.01). This Meta-analysis demonstrated that Danshen Chuan xiongqin injection in the treatment of acute cerebral infarction is safe and effective, but lacks the large multicenter clinical randomized trials to support the treatment outcome.

The Key Roles of GSK-3ß in Regulating Mitochondrial Activity.

Glycogen synthase kinase-3ß (GSK-3ß), a serine/threonine protein kinase, has been reported to show essential roles in molecular pathophysiology of many diseases. Mitochondrion is a dynamic organelle for producing cellular energy and determining cell fates. Stress-induced translocated GSK-3ß may interact with mitochondrial proteins, including PI3K-Akt, PGC-1α, HK II, PKCε, components of respiratory chain, and subunits of mPTP. Mitochondrial pool of GSK-3ß has been implicated in mediation of mitochondrial functions. GSK-3ß exhibits the regulatory effects on mitochondrial biogenesis, mitochondrial bioenergetics, mitochondrial permeability, mitochondrial motility, and mitochondrial apoptosis. The versatile functions of GSK-3ß might be associated with its wide range of substrates. Accumulative evidence demonstrates that GSK-3ß inactivation may be potentially developed as the promising strategy in management of many diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). Intensive efforts have been made for exploring GSK-3ß inhibitors. Natural products provide us a great source for screening new lead compounds in inactivation of GSK-3ß. The key roles of GSK-3ß in mediation of mitochondrial functions are discussed in this review.

miR-365 Ameliorates Dexamethasone-Induced Suppression of Osteogenesis in MC3T3-E1 Cells by Targeting HDAC4.

Glucocorticoid administration is the leading cause of secondary osteoporosis. In this study, we tested the hypotheses that histone deacetylase 4 (HDAC4) is associated with glucocorticoid-induced bone loss and that HDAC4 dependent bone loss can be ameliorated by miRNA-365. Our previous studies showed that miR-365 mediates mechanical stimulation of chondrocyte proliferation and differentiation by targeting HDAC4. However, it is not clear whether miR-365 has an effect on glucocorticoid-induced osteoporosis. We have shown that, in MC3T3-E1 osteoblasts, dexamethasone (DEX) treatment decreased the expression of miR-365, which is accompanied by the decrease of cell viability in a dose-dependent manner. Transfection of miR-365 ameliorated DEX-induced inhibition of MC3T3-E1 cell viability and alkaline phosphatase activity, and attenuated the suppressive effect of DEX on runt-related transcription factor 2 (Runx2), osteopontin (OPN), and collagen 1a1 (Col1a1) osteogenic gene expression. In addition, miR-365 decreased the expression of HDAC4 mRNA and protein by direct targeting the 3'-untranslated regions (3'-UTR) of HDAC4 mRNA in osteoblasts. MiR-365 increased Runx2 expression and such stimulatory effect could be reversed by HDAC4 over-expression in osteoblasts. Collectively, our findings indicate that miR-365 ameliorates DEX-induced suppression of cell viability and osteogenesis by regulating the expression of HDAC4 in osteoblasts, suggesting miR-365 might be a novel therapeutic agent for treatment of glucocorticoid-induced osteoporosis.

Apigenin promotes osteogenic differentiation of human mesenchymal stem cells through JNK and p38 MAPK pathways.

Apigenin is a plant-derived flavonoid and has been reported to prevent bone loss in ovariectomized mice, but the role of apigenin on osteogenic differentiation of human mesenchymal stem cells (hMSCs) has not been reported. In the present study, the effect of apigenin on osteogenic differentiation of hMSCs was explored. Our results showed that apigenin treatment significantly increased alkaline phosphatase (ALP) activity and mineralization in hMSCs. RT-PCR revealed that apigenin markedly up-regulated the mRNA expression of osteopontin (OPN) and the transcription factors runt-related transcription factor 2 (Runx2). The expression of Runx2 and osterix (OSX) proteins were also increased in hMSCs differentiating into osteoblasts after treatment with apigenin. Furthermore, we investigated the signaling pathways responsible for osteogenic differentiation of apigenin in hMSCs. We found that apigenin treatment significantly increased the levels of p-JNK, p-p38 in hMSCs and addition of the inhibitors of JNK (SP600125) or p38 MAPK (SB203580) eliminated the stimulating effects of apigenin. In addition, addition of SP600125 or SB203580 also blocked apigenin-induced ALP activity, OPN, Runx2, and OSX expression and meanwhile inhibited bone nodule formation. Taken together, these findings suggest apigenin promotes the osteogenesis of hMSCs through activation of JNK and p38 MAPK signal pathways which leads to Runx2 and OSX expressions to induce the formation of bone nodule.

Taurine promotes human mesenchymal stem cells to differentiate into osteoblast through the ERK pathway.

Taurine has been reported to influence bone metabolism, but the role of taurine on osteogenic differentiation of human mesenchymal stem cells (hMSCs) remains unclear. In the present study, we investigated the effect of taurine on osteogenic differentiation of hMSCs. The results showed that taurine increased the alkaline phosphatase (ALP) activity and mineralized nodules in hMSCs induced by osteogenic induced medium. Meanwhile, RT-PCR analysis showed that taurine up-regulated the mRNA expression of ALP, osteopontin, Runt-related transcription factor 2 (Runx2) and Osterix in a dose-dependent manner. Furthermore, taurine induced activation of extracellular signal regulated kinase (ERK) and pretreatment with the ERK inhibitor U0126 abolished the taurine-induced osteogenesis of hMSCs. Taken together, our study reveals that taurine promotes the osteogenesis of hMSCs by activating the ERK pathway.

Effect of gut hormones on bone metabolism and their possible mechanisms in the treatment of osteoporosis.

Bone is a highly dynamic organ that changes with the daily circadian rhythm. During the day, bone resorption is suppressed due to eating, while it increases at night. This circadian rhythm of the skeleton is regulated by gut hormones. Until now, gut hormones that have been found to affect skeletal homeostasis include glucagon-like peptide-1 (GLP-1), glucagon-like peptide-2 (GLP-2), glucose-dependent insulinotropic polypeptide (GIP), and peptide YY (PYY), which exerts its effects by binding to its cognate receptors (GLP-1R, GLP-2R, GIPR, and Y1R). Several studies have shown that GLP-1, GLP-2, and GIP all inhibit bone resorption, while GIP also promotes bone formation. Notably, PYY has a strong bone resorption-promoting effect. In addition, gut microbiota (GM) plays an important role in maintaining bone homeostasis. This review outlines the roles of GLP-1, GLP-2, GIP, and PYY in bone metabolism and discusses the roles of gut hormones and the GM in regulating bone homeostasis and their potential mechanisms.

Integration of network pharmacology with experimental validation to reveal the mechanism of action of Longdan Xiegan Decoction against HSV2 infection and determine its effective components.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese Medicine (TCM) has made enormous strides recently in the discovery of anti-herpes simplex virus (HSV) drugs under the guidance of TCM theory. Longdan Xiegan Decoction (LXD), a formulation recorded in the Pharmacopoeia of the People's Republic of China, has proved to be effective against HSV infection. However, its effective components and action mechanism remain unclear. AIM OF THE STUDY: To investigate the effective components and mechanisms of LXD in treating HSV infection based on network pharmacology and experimental validation. MATERIALS AND METHODS: The anti-HSV activities of key compounds predicted by network analysis were detected by antiviral tests. High-performance liquid chromatography (HPLC) was applied to identify the main components of the LXD aqueous extract. Time-of-addition assay and infectivity inhibition reversibility assay were conducted to identify the potential antiviral mechanisms of licochalcone B (LCB). Additionally, we assessed the antiviral effect of LCB in vivo by use of body weight, viral load, histological analysis, and scoring of genital lesions in an HSV2-infected mouse model. RESULTS: Our data demonstrated that some components exhibited significant anti-HSV1/2 activity in vitro, including quercetin, kaempferol, wogonin, formononetin, naringenin, baicalein, isorhamnetin, glabridin, licochalcone A, echinatin, oroxylin A, isoliquiritigenin, pinocembrin, LCB and acacetin. HPLC analysis showed that LCB was the main component of LXD aqueous extract. In vitro experiments revealed that LCB not only inactivated HSV2 particles, but also inhibited HSV2 multiplication through the inhibition of the phosphorylation of Akt and its downstream targets. In vivo experiments confirmed that LCB could significantly reduce viral titer, delay weight loss, and alleviate pathological changes in vaginal tissue in vaginal infection mouse models. CONCLUSION: LCB acted as the main component of LXD, with significant anti-HSV2 infection effects both in vivo and in vitro. This study provides additional evidence of the healing efficacy of LXD against HSV infection and presents an efficient analytical method for further investigation of the mechanisms of TCM in prevention and treatment of various diseases.

Novel Sigma-2 receptor ligand A011 overcomes MDR in adriamycin-resistant human breast cancer cells by modulating ABCB1 and ABCG2 transporter function.

Multidrug resistance (MDR) is thought to be one of the main reasons for the failure of chemotherapy in cancers. ATP-binding cassette subfamily B member 1 (ABCB1) or P-glycoprotein (P-gp) and ATP-binding cassette subfamily G member 2 (ABCG2) play indispensable roles in cancer cell MDR. Sigma-2 (σ2) receptor is considered to be a cancer biomarker and a potential therapeutic target due to its high expression in various proliferative tumors. Recently, σ2 receptor ligands have been shown to have promising cytotoxic effects against cancer cells and to modulate the activity of P-glycoprotein (ABCB1) in vitro experiments, but their specific effects and mechanisms remain to be elucidated. We found that A011, a σ2 receptor ligand with the structure of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline, showed promising cytotoxicity against breast cancer MCF-7 and adriamycin-resistant MCF-7 (MCF-7/ADR), induced apoptosis, and reversed adriamycin (ADR) and paclitaxel resistance in MCF-7/ADR cells. Furthermore, we demonstrated that A011 increased the accumulation of rhodamine 123 and mitoxantrone in MCF-7/ADR cells. A011 significantly decreased the ATPase activity of the ABCB1 and down-regulated ABCG2 protein expression. In addition, A011, administered alone or in combination with ADR, significantly inhibited tumor growth in the MCF-7/ADR tumor-bearing nude mouse model. A011 may be a potential therapeutic agent for the treatment of tumor resistance.

Correction: Zheng et al. Geniposide Ameliorated Dexamethasone-Induced Cholesterol Accumulation in Osteoblasts by Mediating the GLP-1R/ABCA1 Axis. Cells 2021, 10, 3424.

The authors wish to make the following changes to their paper [...].

Identification of phytochemicals in Qingfei Paidu decoction for the treatment of coronavirus disease 2019 by targeting the virus-host interactome.

Qingfei Paidu decoction (QFPDD) has been clinically proven to be effective in the treatment of coronavirus disease 2019 (COVID-19). However, the bioactive components and therapeutic mechanisms remain unclear. This study aimed to explore the effective components and underlying mechanisms of QFPDD in the treatment of COVID-19 by targeting the virus-host interactome and verifying the antiviral activities of its active components in vitro. Key active components and targets were identified by analysing the topological features of a compound-target-pathway-disease regulatory network of QFPDD for the treatment of COVID-19. The antiviral activity of the active components was determined by a live virus infection assay, and possible mechanisms were analysed by pseudotyped virus infection and molecular docking assays. The inhibitory effects of the components tested on the virus-induced release of IL-6, IL-1ß and CXCL-10 were detected by ELISA. Three components of QFPDD, oroxylin A, hesperetin and scutellarin, exhibited potent antiviral activities against live SARS-CoV-2 virus and HCoV-OC43 virus with IC50 values ranging from 18.68 to 63.27 µM. Oroxylin A inhibited the entry of SARS-CoV-2 pseudovirus into target cells and inhibited SARS-CoV-2 S protein-mediated cell-cell fusion by binding with the ACE2 receptor. The active components of QFPDD obviously inhibited the IL-6, IL-1ß and CXCL-10 release induced by the SARS-CoV-2 S protein. This study supports the clinical application of QFPDD and provides an effective analysis method for the in-depth study of the mechanisms of traditional Chinese medicine (TCM) in the prevention and treatment of COVID-19.

A011, a novel small-molecule ligand of σ2 receptor, potently suppresses breast cancer progression via endoplasmic reticulum stress and autophagy.

Breast cancer has surpassed lung cancer to become the most commonly diagnosed cancer in women worldwide. Sigma-2 (σ2) receptor is considered to be a potential therapeutic target for breast cancer because of its high expression in breast cancer cells and low expression in normal breast cells. Many σ2 ligands have been reported to have excellent anticancer activity, but their mechanism of action has not been fully elucidated. We discovered that A011 had high affinity and selectivity for σ2 receptor, reduced proliferation in five cancer cell lines, and significantly inhibited the monoclonal formation ability of MCF-7 cells. Furthermore, A011 rapidly increased the levels of intracellular Ca2+ and reactive oxygen species and induced autophagy. Molecular pharmacology studies revealed that A011 induced endoplasmic reticulum stress, activated the PERK-eIF2α-CHOP pathway and inhibited the activation of the PI3K-Akt-mTOR pathway, leading to cell apoptosis. In an in vivo tumor model, A011 showed obvious anti-tumor activity and no significant toxicity. More importantly, our study demonstrated for the first time that endoplasmic reticulum stress is the main mechanism of anti-cancer effects for σ2 ligands, at least for A011. A011 may potentially be useful as a therapeutic agent for treating breast cancer.

Kaempferol Ameliorates the Inhibitory Activity of Dexamethasone in the Osteogenesis of MC3T3-E1 Cells by JNK and p38-MAPK Pathways.

Kaempferol has been reported to exhibit beneficial effect on the osteogenic differentiation in mesenchymal stem cells (MSC) and osteoblasts. In our previous study, dexamethasone (DEX) demonstrated inhibitory effect on MC3T3-E1 cells differentiation. In this study, we mainly explored the protective effect of kaempferol on the inhibitory activity of DEX in the osteogenesis of MC3T3-E1 cells. We found that kaempferol ameliorated the proliferation inhibition, cell cycle arrest, and cell apoptosis and increased the activity of alkaline phosphatase (ALP) and the mineralization in DEX-treated MC3T3-E1 cells. Kaempferol also significantly enhanced the expression of osterix (Osx) and runt-related transcription factor 2 (Runx2) in MC3T3-E1 cells treated with DEX. In addition, kaempferol attenuated DEX-induced reduction of cyclin D1 and Bcl-2 expression and elevation of p53 and Bax expression. Kaempferol also activated JNK and p38-MAPK pathways in DEX-treated MC3T3-E1 cells. Furthermore, kaempferol improved bone mineralization in DEX-induced bone damage in a zebrafish larvae model. These data suggested that kaempferol ameliorated the inhibitory activity of DEX in the osteogenesis of MC3T3-E1 cells by activating JNK and p38-MAPK signaling pathways. Kaempferol exhibited great potentials in developing new drugs for treating glucocorticoid-induced osteoporosis.

5,7,3',4'-tetramethoxyflavone ameliorates cholesterol dysregulation by mediating SIRT1/FOXO3a/ABCA1 signaling in osteoarthritis chondrocytes.

Dyslipidemia has been associated with the development of osteoarthritis. Our previous study found that 5,7,3',4'-tetramethoxyflavone (TMF) exhibited protective activities against the pathological changes of osteoarthritis. Aim: To investigate the roles of TMF in regulating ABCA1-mediated cholesterol metabolism. Methods: Knockdown and overexpression were employed to study gene functions. Protein-protein interaction was investigated by co-immunoprecipitation, and the subcellular locations of proteins were studied by immunofluorescence. Results: IL-1ß decreased ABCA1 expression and induced apoptosis. Therapeutically, TMF ameliorated the effects of IL-1ß. FOXO3a knockdown expression abrogated the effects of TMF, and FOXO3a overexpression increased ABCA1 expression by interacting with LXRα. TMF promoted FOXO3a nuclear translocation by activating SIRT1 expression. Conclusions: TMF ameliorates cholesterol dysregulation by increasing the expression of FOXO3a/LXRα/ABCA1 signaling through SIRT1 in C28/I2 cells.

Geniposide Ameliorated Dexamethasone-Induced Cholesterol Accumulation in Osteoblasts by Mediating the GLP-1R/ABCA1 Axis.

BACKGROUND: Overexposure to glucocorticoid (GC) produces various clinical complications, including osteoporosis (OP), dyslipidemia, and hypercholesterolemia. Geniposide (GEN) is a natural iridoid compound isolated from Eucommia ulmoides. Our previous study found that GEN could alleviate dexamethasone (DEX)-induced differentiation inhibition of MC3T3-E1 cells. However, whether GEN protected against Dex-induced cholesterol accumulation in osteoblasts was still unclear. METHODS: DEX was used to induce rat OP. Micro-CT data was obtained. The ALP activity and mineralization were determined by the staining assays, and the total intracellular cholesterol was determined by the ELISA kits. The protein expression was detected by western blot. RESULTS: GEN ameliorated Dex-induced micro-structure damages and cell differentiation inhibition in the bone trabecula in rats. In MC3T3-E1 cells, Dex enhanced the total intracellular cholesterol, which reduced the activity of cell proliferation and differentiation. Effectively, GEN decreased DEX-induced cholesterol accumulation, enhanced cell differentiation, and upregulated the expression of the GLP-1R/ABCA1 axis. In addition, inhibition of ABAC1 expression reversed the actions of GEN. Treatment with Exendin9-39, a GLP-1R inhibitor, could abrogate the protective activity of GEN. CONCLUSIONS: GEN ameliorated Dex-induced accumulation of cholesterol and inhibition of cell differentiation by mediating the GLP-1R/ABCA1 axis in MC3T3-E1 cells.