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The modification of Wnt and Notch signaling pathways by hypoxia, and its association with osteoblast proliferation and apoptosis remain to be fully elucidated. To investigate Wnt-Notch crosstalk, and its role in hypoxia-induced osteoblast proliferation and apoptosis regulation, the present study investigated the effects of cobalt-mimicked hypoxia on the mouse pre-osteoblast-like cell line, MC3T3-E1, when the Notch signals were repressed using a γ-secretase inhibitor DAPT. The data showed that the cobalt-mimicked hypoxia suppressed cell proliferation under normal conditions, but increased cell proliferation under conditions of Notch repression, in a concentration-dependent manner. The results of western blot and reverse transcription-quantitative polymerase chain reaction analyses showed that the cobalt treatment increased the levels of activated β-catenin protein and the expression levels of the target genes, axis inhibition protein 2 and myelocytomatosis oncogene, under DAPT-induced Notch repression. However, no significant changes were found in the expression levels of the Notch intracellular domain protein or the Notch target gene, hes1. In a β-catenin gene-knockdown experiment, the proliferation of the MC3T3-E1 cells under hypoxia were decreased by DAPT treatment, and knockdown of the expression of hypoxia-inducible factor-1α (HIF-1α) suppressed the cobalt-induced increase in Wnt target gene levels. No significant difference in cell proliferation rate was found following DAPT treatment when the expression of HIF-1α was knocked down. The results of the present study showed the opposing effects of Wnt and Notch signaling under cobalt-mimicked hypoxia, which were partially regulated by HIF-1α, The results also showed that osteoblast proliferation was dependent on Wnt-Notch signal crosstalk. [ABSTRACT FROM AUTHOR]

The present study aimed to determine the antitumor effects of polysaccharides extracted from Pleurotus ostreatus mycelium on gastric cancer in vitro and in vivo. Polysaccharides were extracted from Pleurotus ostreatus mycelium and an antitumor component, known as Pleurotus ostreatus mycelium polysaccharides 2 (POMP2), with a relative molecular weight of 29 kDa, was then sequentially purified using Sephadex G200 size-exclusion chromatography and diethylaminoethyl-52 cellulose ion-exchange chromatography. The MTT method was used to determine the proliferation of BGC-823 cells treated with POMP2; cell migration assay, colony formation assay and in vivo antitumor tests were used to assess the effect of POMP2 on migration, cell survival and the in vivo tumor formation of BGH-823 cells. Results of the MTT assay indicated that POMP2 had a marked inhibitory effect on the BGC-823 human gastric cancer cell line; when administered at a concentration of 400 mg/l for 72 h, the rate of inhibition was 35.6%. In addition, the colony forming capacity of the BGC-823 cells was significantly reduced following treatment with POMP2. A migration assay indicated that the invasive capabilities of the BGC-823 cells were also significantly inhibited by POMP2. Furthermore, in vivo tests of mice engrafted with BGC-823 cancer cells demonstrated that both tumor weight and volume were markedly reduced following two weeks of treatment with POMP2. The results of the present study suggested that the polysaccharide POMP2 may have a potential application as a natural antitumor treatment for gastric cancer. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is the most common type of endocrine disorder, affecting 5-11% of women of reproductive age worldwide. Transcription factors (TFs) and microRNAs are considered to have crucial roles in the developmental process of several diseases and have synergistic regulatory actions. However, the effects of TFs and microRNAs, and the patterns of their cooperation in the synergistic regulatory network of PCOS, remain to be elucidated. The present study aimed to determine the possible mechanism of PCOS, based on a TF-microRNA synergistic regulatory network. Initially, the differentially expressed genes (DEGs) in PCOS were identified using microarray data of the GSE34526 dataset. Subsequently, the TFs and microRNAs which regulated the DEGs of PCOS were identified, and a PCOS-associated TF-microRNA synergistic regulatory network was constructed. This network included 195 DEGs, 136 TFs and 283 microRNAs, and the DEGs were regulated by TFs and microRNAs. Based on topological and functional enrichment analyses, SP1, mir-355-5p and JUN were identified as potentially crucial regulators in the development of PCOS and in characterizing the regulatory mechanism. In conclusion, the TF-microRNA synergistic regulatory network constructed in the present study provides novel insight on the molecular mechanism of PCOS in the form of synergistic regulated model. [ABSTRACT FROM AUTHOR]

Telomeric repeat binding factor 1 (TERF1) has been identified as a tumor suppressor gene in numerous types of human cancer. However, the expression of TERF1 and its mechanism in prostate cancer (PCa) remains unclear. The present study aimed to explore the expression and functions of TERF1 in PCa. The UALCAN database was used to analyze the differential expression of TERF1 between normal prostate tissue and primary PCa tissue. Cell apoptosis was analyzed by Annexin V/propidium iodide staining, and wound healing and Transwell assays were used to detect the cell migration and invasion abilities, respectively. The cell viability was analyzed using an MTT assay. Reverse transcription‑quantitative PCR and western blotting were used to analyze the mRNA and protein expression levels, respectively, of epithelial‑mesenchymal transition (EMT) markers following TERF1 knockdown in the PC3 cell line. A dual luciferase reporter assay was used to verify the association between TERF1 and microRNA (miR)‑155 predicted by bioinformatics analysis. Rescue experiments were performed to determine the role of the miR‑155/TERF1 axis in regulating the cellular behaviors of PCa. The results demonstrated that the expression levels of TERF1 in the primary prostate tumors were significantly downregulated compared with in prostate normal tissue. TERF1 silencing was discovered to significantly promote cell viability, migration and invasion, while suppressing cell apoptosis. The impact of TERF1 on PC3 cells was suggested to occur through the EMT pathway. TERF1 was confirmed to be the direct target of miR‑155. The overexpression of miR‑155 promoted the viability, migration and invasion, while suppressing the apoptosis of the PC3 cell line, while the knockdown of miR‑155 in PC3 cells achieved the opposite trends. In addition, TERF1 overexpression reversed the promotive effects of upregulated miR‑155 expression levels on the migration and apoptosis of PC3 cells. On the contrary, the knockdown of TERF1 reversed the migration and apoptosis abilities of the downregulated miR‑155 expression levels on the cellular behaviors of PC3 cells. In conclusion, TERF1, as a direct target of miR‑155, was discovered to be significantly downregulated in PCa, which was suggested to promote the migration and invasion of PCa via the EMT pathway. [ABSTRACT FROM AUTHOR]

The present study was performed to investigate the role of p38 mitogen-activated protein kinase (MAPK) in the resorption of herniated intervertebral discs in 30 rats. In the non-contained and p38 MAPK inhibition (p38i) groups, two coccygeal intervertebral discs (IVDs) were removed and wounded prior to relocation into the subcutaneous space of the skin of the back. In the contained group, the cartilage endplates maintained their integrity. Furthermore, SB203580 was injected intraperitoneally into the p38i group, whereas saline was injected into the other two groups. In the non-contained group, the weight of the relocated IVDs decreased to a greater extent over time when compared with the contained and p38i groups. Phosphorylated p38, tumor necrosis factor-a, and interleukin-1β were observed to exhibit higher expression levels in the non-contained group compared with the contained and p38i groups, at weeks 1 and 4 post-surgery. The expression level of caspase-3 and the densities of apoptotic disc cells were significantly higher in the non-contained group compared with the contained and p38i groups at 4 weeks post-surgery. In conclusion, p38 MAPK induces apoptosis in IVDs, while also accelerating the resorption of the relocated IVDs. Thus, p38 MAPK may be important in spontaneous resorption of IVDs. [ABSTRACT FROM AUTHOR]

Malignant gliomas are a common type of primary tumor of the central nervous system. In spite of current intensive therapy, the prognosis of patients with malignant glioma remains poor, hence the development of novel therapeutic modalities is necessary. Cell apoptosis is a frequent target in the development of anti-cancer drugs. Fatsioside A, a novel baccharane-type triterpenoid glycoside, is extracted from the fruits of Fatsia japonica. Previous studies have shown that Fatsioside A induces growth inhibition, cell cycle arrest and apoptosis in C6 rat glioma cells and U251 human glioma cells. However, to the best of our knowledge, no detailed studies have reported its effect on U87MG glioma cells and its exact mechanisms remain unknown. In the current study, the growth inhibitory effect of Fatsioside A on U87MG cells was evaluated and the underlying molecular mechanisms were explored. Through the use of flow cytometry and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, it was determined that Fatsioside A markedly inhibits the growth of U87MG cells. Mechanistic studies demonstrated that Fatsioside A induces growth inhibition of U87MG cells via the induction of endoplasmic reticulum (ER) stress, which was supported by the upregulation of ER stress markers, including elevated levels of phosphorylation of PERK and eIF2α, the increased expression levels of CHOP and the accelerated cleavage of caspase-4. The downregulation of CHOP via CHOP-specific siRNA reduced the growth-inhibitive effect of Fatsioside A on U87MG cells, further confirming the role of the ER stress response in mediating Fatsioside A-induced growth inhibition. In conclusion, Fatsioside A inhibits glioma cell growth via the induction of ER stress-mediated apoptosis. This may provide a molecular basis for the development of Fatsioside A into a drug candidate for the treatment of malignant glioma. [ABSTRACT FROM AUTHOR]

Omentin is a novel adipokine, which is expressed in and released from omental adipose tissue. In the present study, the effect of omentin on neural stem cells (NSCs) was investigated. NSCs are a subtype of stem cell in the nervous system, which are able to self-renew and generate neurons and glia for repairing neural lesions. Mouse NSCs were isolated and cultured in vitro. Treatment with recombinant omentin for 3 and 5 days significantly increased the size of NSC neurospheres (P<0.01) and enhanced NSC cell viability in normal conditions. In addition, omentin protected against the decrease in cell viability induced by the pro-inflammatory cytokine tumor necrosis factor-α. In the NSCs, incubation of omentin for 2, 4, 6, 8 and 16 h enhanced the phosphorylation of Akt at the Thr308 site and of AS160 at the Ser318 site, peaking 6 h after treatment. Additionally, treatment with LY294002 (10 μM), a specific inhibitor of phosphatidylinositol 3-kinase/Akt signaling, eliminated the omentin-induced increase in neurosphere size and cell viability. Overall, the present study provided the first evidence, to the best of our knowledge, that omentin promotes the growth and survival of NSCs in vitro through activation of the Akt signaling pathway. These results may contribute to the understanding of the role of omentin in the nervous system. [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide (SPIO) nanoparticles generate superparamagnetism, thereby resulting in an inhomogeneous local magnetic field, which shortens the T2 value on magnetic resonance imaging (MRI). The purpose of the present study was to use MRI to track bone marrow mesenchymal stem cells (BMSCs) labeled with SPIO in a rat model of myocardial infarction. The BMSCs were isolated from rats and labeled with SPIO. The anterior descending branch of the coronary artery was ligated under anesthesia. Two weeks later, the rats received, at random, 5x107 SPIO-labeled BMSCs, 5x107 unlabeled BMSCs or a vehicle (100 µl phosphate-buffered saline) via direct injection into the ischemic area (20 animals/group). MRI was used to track the SPIO-labeled BMSCs and the rats were then sacrificed to verify the presence of BMSCs using immunohistochemistry with an anti-CD90 antibody. The procedure labeled 99% of the BMSCs with SPIO, which exhibited low-intensity signals on T2 and T2* MRI imaging. At 24 h post-BMSC transplantation, low-intensity MRI signals were detected on the T2 and T2* sequences at the infarction margins. After 3 weeks following transplantation, low-intensity signals started to appear within the infarcted area; however, the signal intensity subsequently decreased and became indistinct. Immunohistochemistry revealed that the SPIO-labeled BMSCs migrated from the margin into the infarcted region. In conclusion, the BMSCs were readily labeled with SPIO and in vivo and MRI tracking demonstrated that the SPIO-labeled BMSCs established and grew in the infarcted myocardium. [ABSTRACT FROM AUTHOR]

Fulminant hepatic failure is a severe clinical syndrome associated with a high rate of patient mortality. Recent studies have shown that in addition to its hematopoietic effect, erythropoietin (EPO) has multiple protective effects and exhibits antiapoptotic, antioxidant and anti-inflammatory activities. The present study aimed to determine the hepatoprotective effect of EPO and to elucidate the underlying mechanisms using a D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced model of acute liver injury. Experimental groups of mice were administered with various doses of EPO (1,000, 3,000 or 10,000 U/kg, intraperitoneal) once per day for 3 days, prior to injection with D-GalN (700 mg/kg)/LPS (10 μg/kg). Mice were sacrificed 8 h after treatment with D-GalN/LPS. Liver function and histopathology, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and EPO receptor (EPOR) and phosphatidylinositol 3-kinase (PI3K) mRNA expression were evaluated. D-GalN/LPS administration markedly induced liver injury, as evidenced by elevated levels of serum aminotransferases, as well as histopathological changes. Compared with the D-GalN/LPS group, pretreatment with EPO significantly decreased the levels of aspartate aminotransferase, alanine aminotransferase and MDA, and increased the activities of SOD and GSH-Px. Furthermore, the protective effects of EPO were paralleled by an upregulation in the mRNA expression of EPOR and PI3K. These data suggest that EPO can ameliorate D-GalN/LPS-induced acute liver injury by reducing oxidative stress and upregulating the mRNA expression of EPOR and PI3K. [ABSTRACT FROM AUTHOR]

Dural arteriovenous fistulas (DAVFs) are associated with venous hypertension. Numerous studies have revealed high expression levels of vascular endothelial growth factor (VEGF) in human DAVF specimens, as well as in animal models of experimental venous hypertension. Lhe objective of the present study was to clarify whether the VEGF signaling pathway is important in the development of DAVFs. Rats (n=216) were randomly divided into six groups. In the rats from five groups (groups A and C-E, n=45 in each group; group B, n=12), experimental venous hypertension was induced by right common carotid artery (CCA)-external jugular vein (EJV) anastomosis, superior sinus occlusion and left transver sinus occlusion, while the remaining group (group F, n=24) underwent sham surgery. The rats in group A received a VEGF recombinant adenovirus injection into the distal section of the right EJV 30 min prior to anastomosis of the CCA and EJV. An equivalent control adenovirus was injected into the right EJV of group B rats prior to anastomosis. The rats in group C received no virus prior to anastomosis and no medicine subsequent to surgery. The group D rats were lavaged with Vatalanib, a VEGF receptor (VEGFR) inhibitor, and the group E rats were lavaged with an equal quantity of saline weekly following surgery. Six rats from groups A-E and one rat from group F were sacrificed in the first, second, fourth and twelfth weeks after surgery for immunohistochemical analysis of VEGF expression and analysis of microvessel density. Cerebral angiography was performed on the remaining rats in each group on the twelfth [ABSTRACT FROM AUTHOR]