Silencing of circ-NT5C2 retards the progression of IL-1ß-induced osteoarthritis in an in vitro cell model by targeting the miR-142-5p/NAMPT axis.

Osteoarthritis (OA) is a degenerative disease that occurs mostly in the elderly, and its specific pathogenesis is still unknown, but recent studies have found that circular RNA generally display aberrant expression in OA. Our study explored the expression characteristics and mechanism of action of circ-NT5C2 in OA. Circ-NT5C2, microRNA-142-5p (miR-142-5p), and nicotinamide phosphoribosyltransferase (NAMPT) mRNA levels were measured using RT-qPCR. Western blot was employed to assess the protein level of NAMPT and extracellular matrix (ECM) production-related markers. The viability, proliferation, apoptosis and inflammation were examined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Relationship between miR-142-5p and circ-NT5C2 or NAMPT was demonstrated by dual-luciferase reporter system and RNA immunoprecipitation assay. We reported that circ-NT5C2 and NAMPT were greatly upregulated, and miR-142-5p level was constrained in OA tissues and in a cell model. Circ-NT5C2 silencing alleviated IL-1ß-induced inhibitory effects on chondrocyte proliferation and ECM generation, meanwhile the promotional role of IL-1ß on chondrocyte apoptosis and inflammation was also weakened. The targeting relationship of miR-142-5p with either circ-NT5C2 or NAMPT was confirmed. Knockdown of miR-142-5p reversed the suppressive effects of circ-NT5C2 silencing on the OA progression in vitro, and NAMPT overexpression also attenuated the effects of miR-142-5p upregulation in an OA cell model. Collectively, circ-NT5C2 accelerated the OA process by targeting the miR-142-5p/NAMPT axis. This study provides valuable information to find a better treatment for OA.

Frequency, prognosis and treatment modalities of newly diagnosed small bowel cancer with liver metastases.

BACKGROUND: Population-based analysis for the liver metastases of small bowel cancer is currently lacking. This study aimed to analyze the frequency, prognosis and treatment modalities for newly diagnosed small bowel cancer patients with liver metastases. METHODS: Patients with small bowel cancer diagnosed from 2010 to 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Binary logistic regression analysis was performed to determine predictors for the presence of liver metastases at diagnosis. Kaplan-Meier method and Cox regression analyses were performed for survival analyses. RESULTS: A total of 1461 small bowel cancer patients with liver metastases at initial diagnosis were identified, representing 16.5% of the entire set and 63.9% of the subset with metastatic disease to any distant site. Primary tumor with poorer histological type, larger tumor size, later N staging, more extrahepatic metastatic sites, and tumor on lower part of small intestine had increased propensity of developing liver metastases. The combined diagnostic model exhibited acceptable diagnostic efficiency with AUC value equal to 0.749. Patients with liver metastases had significant poorer survival (P < 0.001) than those without liver metastases. In addition, combination of surgery and chemotherapy (HR = 0.27, P < 0.001) conferred the optimal survival for patients with adenocarcinoma, while the optimal treatment options for NEC and GIST seemed to be surgery alone (HR = 0.24, P < 0.001) and chemotherapy alone (HR = 0.08, P = 0.022), respectively. CONCLUSIONS: The combined predictor had a good ability to predict the presence of liver metastases. In addition, those patients with different histologic types should be treated with distinct therapeutic strategy for obtaining optimal survival.

Comparison of P75 NTR-positive and -negative etcomesenchymal stem cell odontogenic differentiation through epithelial-mesenchymal interaction.

OBJECTIVES: The aim of this study was to investigate differences of odonto-differentiation between P75 -neurotrophin receptor (P75 -NTR)-positive ectomesenchymal stem cells (P75+EMSCs) and P75 -NTR-negative ectomesenchymal stem cells (P75-EMSCs), and their underlying mechanisms. MATERIALS AND METHODS: Primary cranial neural crest-derived cells (CNC) were isolated from the first branchial arches, and P75+EMSCs and P75-EMSCs were sorted by fluorescence-activated cell sorting. Differentiation of P75+EMSCs or P75-EMSCs into odontoblast-like cells was induced by dental epithelial cells in vitro or in vivo. Differential gene expression profiles between P75+EMSCs and P75-EMSCs were analysed by microarray assay. Smad4-specific small interfering RNA and activator kartogenin were used to treat the cells, to evaluate effects of Smad4 in odonto-differentiation of P75+EMSCs or P75-EMSCs. RESULTS: Under induction of dental epithelium conditioned medium, P75+EMSCs had more mineralized node formation and higher expression of Dmp1 and Dspp compared to P75-EMSCs. In our in vivo study, graft of P75+EMSCs recombination with dental epithelium showed higher expression of DMP1 and DSP. Knock-down of Smad4 in P75+EMSCs significantly downregulated expression of DMP1 and DSP, while activation of Smad4 in P75-EMSCs by the activator kartogenin, significantly increased DSP and DMP1 expression. CONCLUSIONS: P75+EMSCs showed more odonto-differentiation potential than P75-EMSCs both in vivo and in vitro. Smad4 played a critical role in determination of odonto-differentiation potential of CNC-derived EMSCs.

Aberrant promoter DNA methylation inhibits bone morphogenetic protein 2 expression and contributes to drug resistance in breast cancer.

Bone morphogenetic protein 2 (BMP2) is a growth factor that is involved in the development and progression of various types of cancer. However, the epigenetic regulation of the expression of BMP2 and the association between BMP2 expression and drug resistance in breast cancer remains to be elucidated. The present study reported that the expression of BMP2 was significantly decreased in primary breast cancer samples and the MCF­7/ADR breast cancer mulitdrug resistance cell line, which was closely associated with its promoter DNA methylation status. The expression of BMP2 in MCF­7/ADR cells markedly increased when treated with 5­Aza­2'­deoxycytidine. Knockdown of BMP2 by specific small interfering RNA enhanced the chemoresistance of the MCF­7 breast cancer cell line. These findings indicated that epigenetic silencing of BMP2 in breast cancer may be involved in breast cancer progression and drug resistance, and provided a novel prognostic marker and therapeutic strategy for breast cancer.

Pharmacological blockade of the MaxiK channel attenuates experimental acute pancreatitis and associated lung injury in rats.

Increasing evidence has recently demonstrated that soluble heparan sulfate (HS), a degradation product of extracellular matrix produced by elastase, plays a key role in the aggravation of acute pancreatitis (AP) and associated lung injury. However little is known about the detailed mechanism underlying HS-induced inflammatory cascade. Our previous work has provided a valuable clue that a large-conductance K(+) channel (MaxiK) was involved in the HS-stimulated activation of murine macrophages. Here we attempted to ask whether pharmacological inhibition of the MaxiK channel will exert beneficial effects on the treatment of AP and secondary lung injury. The protective effects of paxilline, a specific blocker of MaxiK, on rats against sodium taurocholate induced AP were evaluated. Our data showed that paxilline substantially attenuated AP and resultant lung injury, mainly by limiting the burst of inflammatory responses, as proven by decreased plasma concentrations of tumor necrosis factor-α and macrophage inflammatory protein-2, together with unimpaired pancreatic enzyme activities in rats suffering from AP. Compared with the therapeutic administration, pre-treatment of paxilline showed superior potential to slow down the progress of AP. Furthermore, AP rats received paxilline exhibited improved histopathologic alterations both in the pancreas and the lungs, and even lower lung MPO activity. Taken together, our study provides evidence that MaxiK is involved in the spread of inflammatory responses and the following lung injury during the attack of AP, indicating that this ion channel is a promising candidate as a therapeutic target for AP.

Ecto-mesenchymal stem cells from facial process: potential for muscle regeneration.

Ecto-mesenchymal stem cells (EMSCs) originate from the cranial neural crest and participate in the formation of tooth, salivary, and muscle in early development stage. The transplantation of EMSCs, a potential source of myoblast stem cell, might improve muscle regeneration. The purpose of this study was to explore whether EMSCs have the potential to differentiate and display a myogenic phenotype in vitro the in vitro. Here, we characterized the EMSCs isolated from the facial process, and p75 + EMSCs were collected by a FACS calibur flow cytometer. In vitro, p75 + EMSCs induced by DMSO can accumulate and fuse into multinucleated myotubes and further differentiate into the skeletal muscle cells in form of cell sheet. Functional myoblast phenotypes of p75 + EMSCs were found in vivo model of muscle injury. The remarkable ability of stem cells to regenerate skeletal muscle indicated their potential role in the cell therapy and tissue engineering of the skeletal muscle.

Effects of hypoxia on the proliferation, mineralization and ultrastructure of human periodontal ligament fibroblasts in vitro.

This study aimed to investigate the effects of hypoxia on the proliferation, mineralization and ultrastructure of human periodontal ligament fibroblasts (HPLFs) at various times in vitro in order to further study plateau-hypoxia-induced periodontal disease. HPLFs (fifth passage) cultured by the tissue culture method were assigned to the slight (5% O2), middle (2% O2), and severe hypoxia (1% O2) groups and the control (21% O2) group, respectively. At 12, 24, 48 and 72 h, the proliferation and alkaline phosphatase (ALP) activities were detected. The ultrastructure of the severe hypoxia group was observed. HPLFs grew more rapidly with an increase in the degree of hypoxia at 12 and 24 h, and significant levels of proliferation (P<0.05) were observed in the severe hypoxia group at 24 h. Cell growth was restrained with an increase in the degree of hypoxia at 48 and 72 h, and the restrictions were clear (P<0.05) in the middle and severe hypoxia groups. ALP activity was restrained with increasing hypoxia at each time point. The restrictions were marked (P<0.05) in the severe hypoxia group at 24 h and in the middle and severe hypoxia groups at 48 and 72 h. However, the restriction was more marked (P<0.05) in the severe hypoxia group at 72 h. An increase was observed in the number of mitochondria and rough endoplasmic reticula (RER), with slightly expanded but complete membrane structures, in the severe hypoxia group at 24 h. At 48 h, the number of mitochondria and RER decreased as the mitochondria increased in size. Furthermore, mitochondrial cristae appeared to be vague, and a RER structural disorder was observed. At 72 h, the number of mitochondria and RER decreased further when the mitochondrial cristae were broken, vacuolar degeneration occurred, and the RER particles were reduced while the number of lysosomes increased. HPLF proliferation and mineralization was restrained. Additionally, HPLF structure was broken for a relatively long period of time in the middle and severe hypoxia groups. This finding demonstrated that hypoxia was capable of damaging the metabolism, reconstruction and recovery of HPLFs. The poor state of HPLFs under hypoxic conditions may therefore initiate or aggravate periodontal disease.

Characterization of p75(+) ectomesenchymal stem cells from rat embryonic facial process tissue.

Several populations of stem cells, including those from the dental pulp and periodontal ligament, have been isolated from different parts of the tooth and periodontium. The characteristics of such stem cells have been reported as well. However, as a common progenitor of these cells, ectomesenchymal stem cells (EMSCs), derived from the cranial neural crest have yet to be fully characterized. The aim of this study was to better understand the characteristics of EMSCs isolated from rat embryonic facial processes. Immunohistochemical staining showed that EMSCs had migrated to rat facial processes at E11.5, while the absence of epithelial invagination or tooth-like epithelium suggested that any epithelial-mesenchymal interactions were limited at this stage. The p75 neurotrophin receptor (p75NTR), a typical neural crest marker, was used to select p75NTR-positive EMSCs (p75(+) EMSCs), which were found to show a homogeneous fibroblast-like morphology and little change in the growth curve, proliferation capacity, and cell phenotype during cell passage. They also displayed the capacity to differentiate into diverse cell types under chemically defined conditions in vitro. p75(+) EMSCs proved to be homogeneous, stable in vitro and potentially capable of multiple lineages, suggesting their potential for application in dental or orofacial tissue engineering.