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At least 991 records · Page 55

The inhibition of RANKL expression in fibroblasts attenuate CoCr particles induced aseptic prosthesis loosening via the MyD88-independent TLR signaling pathway

Periprosthetic osteolysis and aseptic loosening are mainly caused by wear particles (Ps) that are generated from friction interfaces. However, the mechanisms underlying the development of aseptic loosening remain unclear. Therefore, we aimed toclarify how the myeloid differentiation factor 88 (MyD88)-independent Toll-like receptor (TLR) signaling pathway mediates cobalt and chromium (CoCr)-Ps-induced osteolysis. We quantified the expression levels of TLRs, MyD88, RANKL, and inflammatory factors in patients experiencing aseptic loosening after primary total hip arthroplasty (THA) with metal-on-metal (MoM) bearings and hip osteoarthritis (hOA). We observed the in vitro and in vivo levels of RANKL, TLRs, and MyD88 in fibroblasts challenged with CoCr Ps by applying shMyD88 interference lentivirus vectors to block the MyD88-independent TLR pathway. The levels of TLRs, MyD88, RANKL, and inflammatory factors in the revision THA (rTHA) with MoM group were higher than those in the hOA group. Our data collectively revealed that inhibiting MyD88 expression could reduce osteoclastogenesis in vitro and CoCr-Ps-induced osteolysis in vivo. Our findings suggested that osteoclastogenesis is promoted by the CoCr-Ps-induced expression of RANKL in fibroblasts and that MyD88 is a potential target in the treatment of wear Ps-induced osteolysis.

60 APPLIED LIFE SCIENCES↗

The miR-31-SOX10 axis regulates tumor growth and chemotherapy resistance of melanoma via PI3K/AKT pathway

Highlights: • Firstly found up-regulation of SOX10 and down-regulation of miR-31 in MM. • miR-31 regulated SOX10 by binding to its 3′UTR. • SOX10 regulated tumor growth and chemotherapy resistance of melanoma in vitro and in vivo. • The miR-31-SOX10 axis mediated tumor growth and drug resistance via activation of PI3K/AKT pathway. MicroRNAs were thought to play a regulatory role through complementarity to target messenger RNA (mRNA). Our previous study revealed a miR-31-SOX10 axis that regulated tumor growth and resistance to chemotherapy of melanoma. Up-regulation of SOX10 and down-regulation of miR-31 were found in melanoma tissues. SOX10 was further identified as a target of miR-31. Overexpression of SOX10 dramatically promoted melanoma cell proliferation and chemotherapy resistance both in vitro and in vivo. While enforced miR-31 expression suppressed cell growth and enhanced the chemosensitivity of melanoma cells, the re-expression of SOX10 rescued these effects by activating PI3K/AKT signaling pathway. In conclusion, our results demonstrated that SOX10 acted as an oncogene and was negatively regulated by miR-31, which supports the potential therapeutic strategy against melanoma by targeting the miR-31-SOX10 axis.

60 APPLIED LIFE SCIENCES↗

The FGF2 aptamer inhibits the growth of FGF2-FGFR pathway driven lung cancer cells

Cancers, including lung cancer, are a leading cause of death worldwide. To overcome this deadly disease, multiple modality inhibitors have been developed. These include cytotoxic agents, molecular targeted small molecules, such as tyrosine kinase inhibitors, and neutralizing antibodies. An aptamer is a short single-stranded nucleic acid molecule that is selected in vitro from a large random sequence library based on its high and specific affinity to a target molecule. Aptamers can be applied to therapeutics of various types of diseases, including cancer, due to their strong and specific neutralizing activities. However, the efficacy of aptamer-based therapy for cancer cells is not well characterized. In this study, we aimed to show that the FGF2 aptamer is effective for the treatment of FGF2 dependent lung cancer cells. We previously developed PC9GR lung cancer cells, whose proliferation is dependent on EGFR and FGF2-FGFR pathways in a cell autonomous manner. Using PC9GR cells, we demonstrate that the addition of the FGF2 aptamer induces more significant inhibition of PC9GR cell proliferation than does the addition of EGFR inhibitor alone. Furthermore, the addition of the FGF2 aptamer more significantly inhibits the downstream signals and induces apoptosis to a higher extent than does the addition of EGFR inhibitor alone. Our results show that the FGF2 aptamer inhibits the growth of FGF2-FGFR pathway-dependent lung cancer cells. The findings provide preclinical evidence that aptamers can be useful for cancer treatment.

60 APPLIED LIFE SCIENCES↗

Decreased intracellular chloride promotes ADP induced platelet activation through inhibition of cAMP/PKA instead of activation of Lyn/PI3K/Akt pathway

Decrease of chloride concentration contributes to cardiovascular diseases, however, whether decrease of chloride concentration is involved in platelet activation remains elusive. In the present study, we found that ACI patients had lower serum chloride which would be rescued after Aspirin administration. ADP induced chloride concentration reduction in platelets. Blockade of chloride channel prevented ADP-induced platelet adhesion, activation and aggregation, however, decreasing the extracellular chloride concentration promoted ADP-induced platelet adhesion and activation. Decrease of the extracellular chloride concentration facilitated the inactivation of Src family kinase Lyn, which was not involved in PI3K/Akt phosphorylation. Nevertheless, low chloride concentration promoted the production of platelet cytosol Gαi2 subunit. This subunit prevents AC from converting ATP into cAMP, which therefore, inhibited the phosphorylation of PKA to promote platelet activation. In conclusion, decreased intracellular chloride promotes ADP induced platelet activation through the Gαi2/cAMP/PKA pathway instead of the Lyn/PI3K/Akt signal pathway.

60 APPLIED LIFE SCIENCES↗

LncRNA SNHG20 knockdown suppresses the osteosarcoma tumorigenesis through the mitochondrial apoptosis pathway by miR-139/RUNX2 axis

Highlights: • SNHG20 was up-regulated in osteosarcoma samples and its high-expression indicated the poor prognosis. • SNHG20 knockdown inhibited the proliferation, invasion and promoted the apoptosis of osteosarcoma cells in vitro. • SNHG20 knockdown up-regulated the expression levels of caspase-9, caspase-3 and Bax. • miR-139 both targeted with the 3′-UTR of RUNX2 and SNHG20. • SNHG20/miR-139/RUNX2 axis modulates the osteosarcoma tumorigenesis and apoptosis via mitochondrial apoptosis. Increasing evidence has indicated the important roles of long noncoding RNAs (lncRNAs) in human osteosarcoma tumorigenesis. In present study, we aim to investigate the roles of lncRNA SNHG20 (small nucleolar RNA host gene 20) in osteosarcoma tumorigenesis and explore the in-depth molecular mechanism. Results showed that lncRNA SNHG20 expression was up-regulated in osteosarcoma samples and its high-expression indicated the poor prognosis. Loss-of-functional experiments indicated that SNHG20 knockdown inhibited the proliferation, invasion and induced the apoptosis of osteosarcoma cells in vitro. Specifically, SNHG20 knockdown up-regulated the expression levels of caspase-9, caspase-3 and Bax, indicating that SNHG20 knockdown accelerated the apoptosis of osteosarcoma cells via mitochondrial apoptosis pathway. Bioinformatics analysis revealed that miR-139 both targeted with the 3′-UTR of runt-related transcription factor 2 (RUNX2) and SNHG20, which was verified by luciferase reporter assay and RNA immunoprecipitation (RIP). In conclusion, our data reveals that lncRNA SNHG20/miR-139/RUNX2 axis modulates the osteosarcoma tumorigenesis and apoptosis via mitochondrial apoptosis pathway, providing a novel insight for the pathophysiological process.

60 APPLIED LIFE SCIENCES↗

Adiponectin inhibits osteoclastogenesis by suppressing NF-κB and p38 signaling pathways

Highlights: • Adiponectin inhibits osteoclastogenesis and resorption function in vitro. • Adiponectin suppresses osteoclastogenesis mainly by inhibition of the NF-κB and p38 signaling pathways. • Adiponectin may provide a potential treatment for osteoclast-related diseases,such as osteoporosis. Adiponectin (APN) has been shown to play a key role in regulating bone mineral density (BMD). Nevertheless, the effects of APN on receptor activator of NF-κB ligand (RANKL)-induced osteoclast formation and mechanism of regulation are not entirely clear. The study, therefore, aimed to evaluate the effect of APN on osteoclastogenesis. Our results showed that APN inhibits osteoclastogenesis and resorption function in vitro by suppressing nuclear factor-κB (NF-κB) and p38 signaling pathways, which is essential for osteoclast formation. Moreover, APN blocked the formation of F-actin rings and attenuated osteoclast-mediated bone resorptive function. Therefore, we concluded that APN may provide a potential treatment for osteoclast-related diseases, such as osteoporosis.

60 APPLIED LIFE SCIENCES↗

miR-7-5p acts as a tumor suppressor in bladder cancer by regulating the hedgehog pathway factor Gli3

Although important progresses have been made in the diagnosis and treatment of bladder cancer (BCa), the overall survival for patients with advanced BCa remains poor. It is necessary to uncover the molecular mechanism underlying the initiation and progression of bladder cancer. According to previous reports, mircoRNAs (miRNAs) can regulate tumorigenesis by targeting their downstream mRNAs. This study aims to explore and analyze a novel miRNA-mRNA axis which can regulate the progression of bladder cancer. Based on the microarray analysis, 182 mRNAs were found to be upregulated in BCa tissues. Gene oncology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that these upregulated mRNAs are related with hedgehog pathway. Gli3, an important factor of hedgehog pathway, belongs to these 182 upregulated mRNAs. Therefore, Gli3 was chosen to do further study. Kaplan-Meier analysis revealed that highly expressed Gli3 predicted unfavorable prognosis for patients with BCa. Results of functional experiments indicated the inhibitory effects of silenced Gli3 on cell proliferation, migration and EMT progress. Mechanically, Gli3 was the target mRNA of miR-7-5p in BCa cells. Finally, rescue assays were performed to validate the specific function of miR-7-5p/Gli3 axis in BCa progression. According to all data, we concluded that miR-7-5p acts as a tumor suppressor in BCa by downregulating Gli3.

60 APPLIED LIFE SCIENCES↗

A novel MtHSP70-FPR1 fusion protein enhances cytotoxic T lymphocyte responses to cervical cancer cells by activating human monocyte-derived dendritic cells via the p38 MAPK signaling pathway

Highlights: • MtHSP70-FPR1 induces phenotypic and functional maturation of human monocyte-derived dendritic cells. • MtHSP70-FPR1-matured dendritic cells significantly increase cytotoxic T lymphocytes responses to cervical cancer cells. • P38 MAPK signaling pathway play a vital role in MtHSP70-FPR1-induced dendritic cells maturation. To evaluate the potential effects of recombinant mycobacterium tuberculosis heat shock protein 70-formyl peptide receptor 1 (MtHSP70-FPR1) fusion protein on human monocyte-derived dendritic cell (moDC) maturation; cytotoxic T lymphocyte (CTL) responses to cervical cancer (CC) cells; and the roles of the p38 MAPK, ERK, and JNK pathways in its transition.

60 APPLIED LIFE SCIENCES↗

Anlotinib induces hepatocellular carcinoma apoptosis and inhibits proliferation via Erk and Akt pathway

Although anlotinib, a multi-targeted receptor tyrosine kinase inhibitor has been reported have antitumor effects in many preclinical and clinical trials, little is known about its effect on hepatocellular carcinoma (HCC). Here, we have shown the antitumor effects of anlotinib on HCC. Data indicated that anlotinib application significantly inhibited HCC cell viability, proliferation, colony formation, and prompted apoptosis in vitro. Furthermore, animal experiments also illustrated that anlotinib alleviated HCC progression. Mechanically, we demonstrated that anlotinib treatment downregulated the anti-apoptotic protein Bcl-2 and Survivin, but upregulated pro-apoptotic molecule Bax, which accounts for its therapeutic effect on HCC. Pathway analysis has shown decreased phosphorylation levels of Erk and Akt. Together, this study suggests that anlotinib may have a direct antitumor progression effect on HCC by inhibiting Bcl-2 and Survivin expression, promoting Bax expression via inactivating Erk and Akt pathways and could be a promising agent treating HCC.

60 APPLIED LIFE SCIENCES↗

High mobility group A2 (HMGA2) promotes EMT via MAPK pathway in prostate cancer

Highlights: • HMGA2 expression increases with prostate cancer progression. • Wild-type HMGA2 promotes EMT via MAPK. • Truncated HMGA2 increases cell viability and migration via non-EMT pathway. Studies have shown that High mobility group A2 (HMGA2), a non-histone protein, can promote epithelial-mesenchymal transition (EMT), which plays a critical role in prostate cancer progression and metastasis. Interestingly, full-length or wild-type HMGA2 and truncated (lacking the 3′UTR) HMGA2 isoforms are overexpressed in several cancers. However, there are no studies investigating the expression and differential roles of WT vs truncated HMGA2 isoforms in prostate cancer. Immunohistochemical staining of prostate tissue microarray revealed low membrane expression in normal epithelial prostate cells, and that expression increased with tumor grade as well as a switch from predominantly cytoplasmic HMGA2 in lower tumor grades, to mostly nuclear in high grade and bone metastatic tissue. LNCaP cells stably overexpressing wild-type HMGA2 displayed nuclear localization of HMGA2 and induction of EMT associated with increased Snail, Twist and vimentin expression compared to LNCaP Neo control cells, as shown by immunofluorescence and western blot analyses. This was associated with increased cell migration on collagen shown using boyden chamber assay. Conversely, LNCaP cells overexpressing truncated HMGA2 showed cytoplasmic HMGA2 expression that did not induce EMT yet displayed increased cell proliferation and migration compared to LNCaP Neo. Both wild-type and truncated HMGA2 increased levels of phospho-ERK, and interestingly, treatment with U0126, MAPK inhibitor, antagonized wild-type HMGA2-mediated EMT and cell migration, but did not affect truncated HMGA2-mediated cell proliferation or migration. Therefore, although both wild-type and truncated HMGA2 may promote prostate tumor progression, wild-type HMGA2 acts by inducing EMT via MAPK pathway.

60 APPLIED LIFE SCIENCES↗

CircRNA circ-ITCH suppresses papillary thyroid cancer progression through miR-22-3p/CBL/β-catenin pathway

While recent evidence has uncovered that circular RNAs (circRNAs) are vital regulators of carcinogenesis, their role in papillary thyroid cancer (PTC) is not clearly understood. In this study, we reveal that lower levels of circRNA circ-ITCH are expressed in PTC tissues than in normal adjacent tissues. Gain-of-functional assays show that circ-ITCH overexpression suppresses PTC cell proliferation and invasion and promotes apoptosis in vitro. Overexpression of circ-ITCH also leads to impaired tumor growth in vivo. Bioinformatics analysis and luciferase reporter assays demonstrate that circ-ITCH sponges miR-22-3p to upregulate the expression of CBL, an E3 ligase of nuclear β-catenin. Elevated levels of CBL suppress activation of the Wnt/β-catenin pathway and consequently attenuates PTC progression. In summary, our study reveals a novel signaling pathway of circ-ITCH/miR-22-3p/CBL/β-catenin involved in PTC development and progression.

60 APPLIED LIFE SCIENCES↗

Shikonin exerts anti-inflammatory effects in LPS-induced mastitis by inhibiting NF-κB signaling pathway

Highlights: • Myeloperoxidase decreased when shikonin was given by gavage in LPS-induced mammary gland tissues. • Nuclear factor-κB was inhibited in SHI group both in tissues and cells, comparing with groups challenged by LPS. • SHI exerts less pro-inflammatory cytokines than LPS-challenged group, indicating the potential for mastitis treatment. Previous studies have shown that shikonin(SHI), the bioactive naphthoquinone constituent extracted from Chinese herb Lithospermum Erythrorhizon, possesses the potential to confront inflammation, and has little concerns towards drug residues comparing with antibiotics. While mastitis in dairy industry always trigger great harm to milk yields, effects of SHI on lipopolysaccharides (LPS)-induced mastitis should be measured. Here, we demonstrate anti-inflammatory effects of SHI on LPS-challenged mastitis and elucidate the potential signaling pathway both in vivo and in vitro. As a result, SHI administration mice significantly suffered less impairment of mammary gland and less recruitment of neutrophils than LPS administration mice. SHI significantly suppressed the expression of p-IκBα and p-p65, which are the critical proteins functioning in NF-kB signaling pathway. qPCR results indicate decreasing level of upstream pro-inflammatory cytokines in tissues, such as TNF-α, IL-1β, and IL-6. The results are corresponding with the results in vitro, suggesting the potential usage of SHI as a therapeutic medicine in mastitis.

60 APPLIED LIFE SCIENCES↗

Toosendanin induces caspase-dependent apoptosis through the p38 MAPK pathway in human gastric cancer cells

Highlights: • Toosendanin suppresses viability of various gastric cancer cell lines. • Toosendanin induces G{sub 1}/S cell cycle arrest followed by inhibiting proliferation of AGS and HGC-27 cells. • Toosendanin induces caspase-dependent apoptosis via p38 MAPK signaling pathway in AGS and HGC-27 cells. • Toosendanin can be a promising therapeutic compound for gastric cancer therapy. Although many advances have been made in the treatment of gastric cancer (GC), numerous difficulties, such as the emergence of chemo-drug resistance, continue to lead to disappointing GC prognoses. Thus, novel alternative strategies are urgently needed. The use of natural products could be a viable option to treat GC. Toosendanin (TSN) is a triterpenoid derived from the bark of Melia toosendanin Sieb. et Zucc that has been shown to be highly cytotoxic to multiple cancer cells. As the underlying impact of TSN on GC and its molecular mechanism remain poorly understood, in this study, we performed a series of experiments involving the use of TSN to treat GC cells. In the present study, we showed that TSN suppressed cell viability, inhibited cell proliferation by causing G{sub 1}/S arrest and induced caspase-dependent apoptosis in AGS and HGC-27 cells. The possible mechanism of TSN-induced apoptosis may be associated with the activation of the p38 MAPK pathway. These results demonstrated the potential of TSN as a promising therapeutic compound to treat gastric cancer.

60 APPLIED LIFE SCIENCES↗

β1,6 GlcNAc branches-modified protein tyrosine phosphatase Mu attenuates its tyrosine phosphatase activity and promotes glioma cell migration through PLCγ-PKC pathways

The metastatic potential of malignant tumor has been shown to be correlated with the increased expression of tri- and tetra-antennary β1,6-N-acetylglucosamine (β1,6-GlcNAc) N-glycans. In this study, We found that GnT-V expression was negatively correlated with receptor protein tyrosine phosphatase type μ(RPTPμ) in human glioma tissues. To study whether RPTPμ is a novel substance of GnT-V which further affect RPTPμ′s downstream dephosphorylation function, we preform lentiviral infection with GnT-V gene to construct stably transfected GnT-V glial cell lines. We found RPTPμ undergone severer cleavage in GnT-V transfected glioma cells compare to Mock cells. RPTPμ intracellular domain fragments increased while β1,6-GlcNAc-branched N-glycans increased, in consistent with the decrease of RPTPμ′s catalytic activity. The results showed that abnormal glycosylation could decrease the phosphorylation activity of PTP μ, and affect PLCγ-PKC pathways. Both protease inhibitor Furin and N-glycan biosynthesis inhibitor swainsonine could decrease cell mobility in GnT-V-U87 transfectants and other glioma cell lines. All results above suggest increased post-translational modification of RPTPμ N-glycans by GnT-V attenuates its tyrosine phosphatase activity and promotes glioma cell migration through PLCγ-PKC pathways, and that the β1,6-GlcNAc-branched N-glycans of RPTPμ play a crucial role in glioma invasivity.

60 APPLIED LIFE SCIENCES↗

LINC00662 promotes gastric cancer cell growth by modulating the Hippo-YAP1 pathway

Highlights: • High expression of LINC00662 predicted poor prognosis of gastric cancer patients. • LINC00662 activated Hippo-YAP1 pathway via sponging miR-497-5p. • The LINC00662-miR-497-5p-YAP1 signal axis may be a target of gastric cancer. Long non-coding RNAs (lncRNAs) function as vital regulators of the progression of various diseases, particularly cancers. In the present study, utilizing the Cancer Genome Atlas (TCGA) data set and a series of cell experiments and clinical tissue samples assays, we found that LINC00662 expression was significantly up-regulated in gastric cancer (GC) tissues and cell lines. High expression of LINC00662 predicted poor prognosis compared to in patients showing low expression. Knockdown of LINC00662 expression decreased GC cell proliferation and increased the chemo-sensitivity of GC cells. Further, we demonstrated that knockdown of LINC00662 suppressed the Hippo-YAP1 signaling pathway in GC cells. Mechanistically, LINC00662 regulated YAP1-mediated GC cell proliferation by sponging miR-497-5p. Overall, our results revealed a critical role for the LINC00662-miR-497-5p–YAP1 axis in GC cell growth, providing a new target for GC.

60 APPLIED LIFE SCIENCES↗

Downregulation of miR-223 and miR-19a induces differentiation and promotes recruitment of osteoclast cells in giant-cell tumor of the bone via the Runx2/TWIST-RANK/RANKL pathway

Highlights: • MiR-223 and miR-19a regulate the expression levels of TWIST and Runx2, influence the RANKL-RANK pathway. • MiR-223 and miR-19a regulate the pathophysiological process of osteolytic bone destruction. • Re-expression of miR-223 and miR-19a induces a suppress effect on bone destruction capacity of GCT. Giant-cell tumor (GCT) of the bone is an invasiveness and high recurrent bone tumor that is considered borderline or potentially malignant. To explore the molecular mechanism leading to bone destruction and identify novel targets for treatment, we conducted silencing of miR-223 and miR-19a in stromal giant cells and identified TWIST and Runx2 as their target genes. We investigated the impact of these microRNAs and their target genes on stromal giant cells that promote the differentiation of monocyte/macrophages into osteoclast cells and recruitment to the bone microenvironment, which in turn enhances the bone destruction capacity of GCT. MiR-223 and miR-19a were found to regulate the expression of TWIST and Runx2, influence the RANKL-RANK pathway and the expression of MCP-1, and finally regulate the pathophysiological process of osteolytic bone destruction. Our results indicate that re-expression of miR-223 and miR-19a induces an inhibitory effect on the bone destruction capacity of GCT, suggesting that re-expression of miR-223 and miR-19a can be a novel strategy for the treatment of GCT.

60 APPLIED LIFE SCIENCES↗

Arctigenin shows preferential cytotoxicity to acidity-tolerant prostate carcinoma PC-3 cells through ROS-mediated mitochondrial damage and the inhibition of PI3K/Akt/mTOR pathway

Highlights: • Arctigenin induces preferential cytotoxicity to acid-tolerant PC-3AcT cells. • Arctigenin induced cytotoxicity is linked to ROS-mediated mitochondrial damage. • Arctigenin-induced ROS accumulation was associated with ATP depletion. • PI3K/Akt/mTOR pathway is one of the targets of arctigenin-induced oxidative insults. Extracellular acidity in the tumor microenvironment contributes to chemoresistance of malignant tumors. The objective of this study was to determine anticancer effects of arctigenin, a novel anti-inflammatory lignan extracted from seeds of Arctium lappa, on acidity-tolerant prostate cancer PC-3AcT cells. The PC-3AcT cells manifested increased tolerance to low-pH media with enhanced percent cell viability and increased resistance to docetaxel compared to their parental PC-3 cells. Arctigenin alone or in combination with docetaxel induced potent cytotoxicity. Preferential sensitization of PC-3AcT cells to arctigenin was accompanied by increased cell fractions with sub-G{sub 0}/G{sub 1} peak and annexin V-PE(+), increased ROS levels, decreased mitochondrial membrane potential and cellular ATP content, and inhibition of PI3K/Akt/mTOR pathway. A series of changes caused by arctigenin were efficiently reversed through reducing ROS levels by radical scavenger N-acetylcysteine, thus placing ROS upstream of arctigenin-driven cytotoxicity. Collectively, these results demonstrate that arctigenin can increase oxidative stress-mediated mitochondrial damage of acidity-tolerant PC-3AcT cells, suggesting that arctigenin might be a potential therapeutic candidate to overcome acidic-microenvironment-associated chemotherapeutic resistance in prostate cancer.

60 APPLIED LIFE SCIENCES↗

Rubiadin-1-methyl ether from Morinda officinalis How. Inhibits osteoclastogenesis through blocking RANKL-induced NF-κB pathway

Highlights: • Rubiadin-1-methyl ether (RBM) inhibits osteoclastogenesis at early stage. • RBM inhibits bone resorption by reducing expression of osteoclastic c-Fos and NFATc1. • RBM is involved in RANKL-induced NF-κB signaling pathway in osteoclasts. Rubiadin-1-methyl ether (RBM) is a natural anthraquinone compound isolated from the root of Morinda officinalis How. In our previous study, RBM was found to have inhibitory effects on the TRAP activity of osteoclasts, which means that RBM may be a candidate for therapy of bone diseases characterized by enhanced bone resorption. However, the further effect of RBM on osteoclasts and the underlying mechanism remain unclear. In the present study, we investigated the effects of RBM isolated from Morinda officinalis How. on osteoclasts derived from bone marrow macrophages (BMMs) and the underlying mechanism in vitro. RBM at the dose that did not affect the viability of cells significantly inhibited RANKL-induced osteoclastogenesis and actin ring formation of osteoclast, while RBM performed a stronger effect at the early stage. In addition, RBM downregulated the expression of osteoclast-related proteins, including nuclear factor of activated T cells cytoplasmic 1 (NFATc1), cellular oncogene Fos (c-Fos), matrix metallopeptidase 9 (MMP-9) and cathepsin K (CtsK) as shown by Western blot. Furthermore, RBM inhibited the phosphorylation of NF-κB p65 and the degradation of IκBα as well as decreased the nuclear translocation of p65. Collectively, the results suggest that RBM inhibit osteoclastic bone resorption through blocking NF-κB pathway and may be a promising agent for the prevention and treatment of bone diseases characterized by excessive bone resorption.

60 APPLIED LIFE SCIENCES↗