The osteogenic differentiation of human bone marrow stromal cells induced by nanofiber scaffolds using bioinformatics.

This article aims to investigate the mechanism of behaviors of human bone marrow stromal cells (hBMSCs) affected by scaffold structure combining Monte Carlo feature selection (MFCS), incremental feature selection (IFS) and support vector machine (SVM). The specific differentially expressed genes (DEGs) of hBMSCs cultured on nanofiber (NF) scaffolds and freeform fabrication (FFF) scaffolds were obtained. Key genes were screened from common genes between osteogenic DEGs and NF specific DEGs with MFCS, IFS and SVM. The results demonstrated that NF scaffolds induced hBMSCs to express more genes related to osteogenic differentiation. Finally, 16 key genes were identified among the common genes. The common genes were significantly enriched in Rap1 signaling pathway, extracellular matrix and ossification. The results in this study suggested that the gene expression of hBMSCs was sensitive to NF scaffolds and FFF scaffolds, and the osteogenic differentiation of hBMSCs could be enhanced by NF scaffolds.

Occlusal load modelling significantly impacts the predicted tooth stress response during biting: a simulation study.

Computational models of the masticatory system can provide estimates of occlusal loading during (static) biting or (dynamic) chewing and therefore can be used to evaluate and optimize functional performance of prosthodontic devices and guide dental surgery planning. The modelling assumptions, however, need to be chosen carefully in order to obtain meaningful predictions. The objectives of this study were two-fold: (i) develop a computational model to calculate the stress response of the first molar during biting of a rubber sample and (ii) evaluate the influence of different occlusal load models on the stress response of dental structures. A three-dimensional finite element model was developed comprising the mandible, first molar, associated dental structures, and the articular fossa and discs. Simulations of a maximum force bite on a rubber sample were performed by applying muscle forces as boundary conditions on the mandible and computing the contact between the rubber and molars (GS case). The molar occlusal force was then modelled as a single point force (CF1 case), four point forces (CF2 case), and as a sphere compressing against the occlusal surface (SL case). The peak enamel stress for the GS case was 110 MPa and 677 MPa, 270 MPa and 305 MPa for the CF1, CF2 and SL cases, respectively. Peak dentin stress for the GS case was 44 MPa and 46 MPa, 50 MPa and 63 MPa for the CF1, CF2 and SL cases, respectively. Furthermore, the enamel stress distribution was also strongly correlated to the occlusal load model. The way in which occlusal load is modelled has a substantial influence on the stress response of enamel during biting, but has relatively little impact on the behavior of dentin. The use of point forces or sphere contact to model occlusal loading during mastication overestimates enamel stress magnitude and also influences enamel stress distribution.

NAFLD Induction Delays Postoperative Liver Regeneration of ALPPS in Rats.

BACKGROUND: Associating liver partition and portal vein ligation (ALPPS) is a promising two-step hepatectomy that is beneficial for accumulative regeneration of the future liver remnant (FLR) and avoids postoperative liver failure. AIMS: Our study aimed to evaluate whether nonalcoholic fatty liver disease affected the liver regeneration induced by ALPPS. METHODS: Sprague-Dawley rats fed a high-fat diet were used to construct the NAFLD model. ALPPS were performed, and blood and future liver remnant samples were collected at postoperative days 1 (POD1), POD3, and POD7. RESULTS: The hepatic regeneration rate (HRR) of ALPPS was higher than that of portal vein ligation (PVL) at POD3 and POD7 (p < 0.05), and the number of Ki-67-positive hepatocytes (POD3) and CD68-positive Kupffer cells (POD7) per visual field was higher in the ALPPS group than in the PVL group (p < 0.05). The serum TNF-α, hepatocyte growth factor protein, and the serum IL-6 level were higher in the ALPPS group than in the PVL group at POD3 and POD7. Compared with those of the standard laboratory diet (SLD)-fed rats, the rats with NAFLD exhibited a decrease in the HRR, Ki-67-positive hepatocytes, and CD68-positive Kupffer cells in the FLR. The number of CD68-positive Kupffer cells was lower in rats with NAFLD than that in SLD-fed rats; noteworthily, the serum level of IL-6 and TNF-α changed dramatically after surgeries. CONCLUSIONS: NAFLD induction delayed liver regeneration induced by the ALPPS procedure, which might be associated with hepatocyte proliferation and the number of Kupffer cells.

Circular RNA hsa_circ_0000673 promotes hepatocellular carcinoma malignance by decreasing miR-767-3p targeting SET.

The importance of circular RNAs (circRNAs) in human cancers has gradually been acknowledged. In hepatocellular carcinoma (HCC), several circRNAs have been reported to regulate tumor growth and metastasis. However, the role of hsa_circ_0000673 in HCC remains largely unknown. In this study, we found that hsa_circ_0000673 was significantly upregulated in HCC tissues compared to adjacent non-tumor tissues. Moreover, we found that hsa_circ_0000673 knockdown markedly inhibited the proliferation and invasion of HCC cells in vitro. Besides, hsa_circ_0000673 silence led to delayed tumor growth in vivo. In terms of mechanism, we showed that hsa_circ_0000673 directly associated with miR-767-3p in HCC cells. Via inhibiting miR-767-3p, hsa_circ_0000673 promoted HCC cell proliferation and invasion. Furthermore, we demonstrated that SET was a downstream effector of hsa_circ_0000673/miR-767-3p signaling. We showed that miR-767-3p could significantly promote SET expression by sponging miR-767-3p in HCC cells. Finally, rescue assays indicated that SET expression was essential for the effects of hsa_circ_0000673/miR-767-3p signaling on HCC cell proliferation and invasion. Taken together, our findings demonstrated that hsa_circ_0000673 promoted HCC malignant behaviors via regulating miR-767-3p/SET pathway.

Mefloquine targets ß-catenin pathway and thus can play a role in the treatment of liver cancer.

The current study was designed and performed to investigate the effect of mefloquine on the proliferation and tumor formation potential of liver cancer stem cells. CD133 + HepG2 cells were identified using MACS and showed markedly higher tumor formation potential compared to the parental cells. The secondary tumors formed by CD133 + cells were markedly large in size and more in number compared to the parental cells. Mefloquine treatment of CD133 + HepG2 cells inhibited the proliferation selectively in concentration based manner. The rate of proliferation was inhibited to 82 and 12% in parental and CD133 + sphere forming cells, respectively on treatment with 10 µM concentration of mefloquine. The number of secondary tumors formed by primary tumors was decreased significantly on treatment with 10 µM mefloquine concentration. Treatment of the liver cancer stem cells with mefloquine markedly decreased the potential to undergo self-renewal at 10 µM concentration after 48 h. The results from western blot analysis showed significantly higher expression of cancer stem cell molecules ß-catenin and cyclin D1 in LCSCs. Treatment of the LCSCs with various concentrations of mefloquine reduced the expression levels of ß-catenin and cyclin D1. Administration of the CD133 + cell tumor xenografts in the mice led to the formation of large sized tumors in the control group. However, the tumor growth was inhibited significantly in the mice on treatment with 10 mg/kg doses of mefloquine after day 21. The tumor weight was significantly lower in the animals of mefloquine treatment group compared to the control group. Thus, mefloquine treatment inhibits self-renewal and proliferation potential of cells through targeting ß-catenin pathway.

SIK2 regulates fasting-induced PPARα activity and ketogenesis through p300.

Fatty acid oxidation and subsequent ketogenesis is one of the major mechanisms to maintain hepatic lipid homeostasis under fasting conditions. Fasting hormone glucagon has been shown to stimulate ketone body production through activation of PPARα; however, the signal pathway linking glucagon to PPARα is largely undiscovered. Here we report that a SIK2-p300-PPARα cascade mediates glucagon's effect on ketogenesis. p300 interacts with PPARα through a conserved LXXLL motif and enhances its transcriptional activity. SIK2 disrupts p300-PPARα interaction by direct phosphorylation of p300 at Ser89, which in turn decreases PPARα-mediated ketogenic gene expression. Moreover, SIK2 phosphorylation defective p300 (p300 S89A) shows increased interaction with PPARα and abolishes suppression of SIK2 on PPARα-mediated ketogenic gene expression in liver. Taken together, our results unveil the signal pathway that mediates fasting induced ketogenesis to maintain hepatic lipid homeostasis.

Quantitative proteomic study of human prostate cancer cells with different metastatic potentials.

Metastatic dissemination is a feature of most cancers including prostate cancer (PCa), and is the main cause of treatment failure and mortality. The aim of the study is to explore the mechanisms of PCa metastasis and to search for potential prognostic markers using proteomics. Two-dimensional fluorescent differential gel electrophoresis (2D-DIGE) was used to quantify proteins in normal prostate epithelial cells, bone metastasis-derived PC-3 cells, and visceral metastasis-derived PC-3M cells. Metastatic potential was confirmed by flow cytometry, electron microscopy, proliferating cell nuclear antigen assay, and wound healing assay. Differential protein expression was compared between PCa cells with different metastatic potentials (LNcap, DU145, PC-3 and PC-3M) and normal prostate epithelial cells (RWPE-1). Selected candidate proteins in human prostate tissues were analyzed using GOA, UniProt and GeneCards analyses. Eighty-six proteins were differentially expressed between cell lines (>1.5-fold, P<0.05). Among them, twelve proteins were identified by MALDI-TOF-MS. One protein was upregulated in normal prostate epithelial cells, nine proteins were upregulated in PC-3, and two proteins were upregulated in PC-3M. Proteins were divided into five groups according to their functions. The SETDB1 protein was closely associated with the prognosis of PCa. Bioinformatics suggested that SETDB1 might promote PCa bone metastasis through the WNT pathway. In conclusion, SETDB1 might be associated with the development of bone metastases from PCa. Further study is necessary to assess its exact role in PCa.

Role of ursolic acid chalcone, a synthetic analogue of ursolic acid, in inhibiting the properties of CD133(+) sphere-forming cells in liver stem cells.

The expression of CD133 decreases with differentiation of tumor cell, indicating that CD133 is a specific marker for isolation and identification of CSCs. In the present study the effect of Ursolic acid chalcone (UAC) on CD133(+) hepatocellular carcinoma cell (HCC CSCs) differentiation, their self-renewal, tumorigenic capacity and sensitivity to chemotherapeutic drugs was studied. The results demonstrated that UAC inhibits the expression of CD133(+) in a dose and time-dependent manner in PLC/PRF/5 and Huh7 HCC cells. The inhibition was significant at 50 µM and on day 8. The percentage of CD133(+) cells decreased from an initial 59.3% in PLC/PRF/5 to 37.1% and 78.2% in Huh7 to 59.2% on treatment with UAC. There was inhibition of Oct4, Tert, Bmi1, ß-catenin, ABCG2, and tumor sphere-related gene Ep300. In addition it also decreased number of CK19-positive cells and increased number of CK8/18-positive cells. UAC treatment caused a decrease in self-renewal capability and increase in sensitivity to doxorubicin and vincristine drugs in CD133(+) HCC CSCs. Therefore, UAC can be a potent therapeutic agent to target differentiation of CSC in HCC.

Regulation of T cell proliferation by JMJD6 and PDGF-BB during chronic hepatitis B infection.

T cell functional exhaustion during chronic hepatitis B virus (HBV) infection may contribute to the failed viral clearance; however, the underlying molecular mechanisms remain largely unknown. Here we demonstrate that jumonji domain-containing protein 6 (JMJD6) is a potential regulator of T cell proliferation during chronic HBV infection. The expression of JMJD6 was reduced in T lymphocytes in chronic hepatitis B (CHB) patients, and this reduction in JMJD6 expression was associated with impaired T cell proliferation. Moreover, silencing JMJD6 expression in primary human T cells impaired T cell proliferation. We found that JMJD6 promotes T cell proliferation by suppressing the mRNA expression of CDKN3. Furthermore, we have identified platelet derived growth factor-BB (PDGF-BB) as a regulator of JMJD6 expression. PDGF-BB downregulates JMJD6 expression and inhibits the proliferation of human primary T cells. Importantly, the expression levels of JMJD6 and PDGF-BB in lymphocytes from CHB patients were correlated with the degree of liver damage and the outcome of chronic HBV infection treatment. Our results demonstrate that PDGF-BB and JMJD6 regulate T cell function during chronic HBV infection and may provide insights for the treatment strategies for CHB patients.

Structure-based high-throughput epitope analysis of hexon proteins in B and C species human adenoviruses (HAdVs).

Human adenoviruses (HAdVs) are the etiologic agent of many human infectious diseases. The existence of at least 54 different serotypes of HAdVs has resulted in difficulties in clinical diagnosis. Acute respiratory tract disease (ARD) caused by some serotypes from B and C species is particularly serious. Hexon, the main coat protein of HAdV, contains the major serotype-specific B cell epitopes; however, few studies have addressed epitope mapping in most HAdV serotypes. In this study, we utilized a novel and rapid method for the modeling of homologous proteins based on the phylogenetic tree of protein families and built three-dimensional (3D) models of hexon proteins in B and C species HAdVs. Based on refined hexon structures, we used reverse evolutionary trace (RET) bioinformatics analysis combined with a specially designed hexon epitope screening algorithm to achieve high-throughput epitope mapping of all 13 hexon proteins in B and C species HAdVs. This study has demonstrated that all of the epitopes from the 13 hexon proteins are located in the proteins' tower regions; however, the exact number, location, and size of the epitopes differ among the HAdV serotypes.

Downregulation of the AU-rich RNA-binding protein ZFP36 in chronic HBV patients: implications for anti-inflammatory therapy.

Inflammation caused by chronic hepatitis B virus (HBV) infection is associated with the development of cirrhosis and hepatocellular carcinoma; however, the mechanisms by which HBV infection induces inflammation and inflammatory cytokine production remain largely unknown. We analyzed the gene expression patterns of lymphocytes from chronic HBV-infected patients and found that the expression of ZFP36, an AU-rich element (ARE)-binding protein, was dramatically reduced in CD4(+) and CD8(+) T lymphocytes from chronic HBV patients. ZFP36 expression was also reduced in CD14(+) monocytes and in total PBMCs from chronic HBV patients. To investigate the functional consequences of reduced ZFP36 expression, we knocked down ZFP36 in PBMCs from healthy donors using siRNA. siRNA-mediated silencing of ZFP36 resulted in dramatically increased expression of multiple inflammatory cytokines, most of which were also increased in the plasma of chronic HBV patients. Furthermore, we found that IL-8 and RANTES induced ZFP36 downregulation, and this effect was mediated through protein kinase C. Importantly, we found that HBsAg stimulated PBMCs to express IL-8 and RANTES, resulting in decreased ZFP36 expression. Our results suggest that an inflammatory feedback loop involving HBsAg, ZFP36, and inflammatory cytokines may play a critical role in the pathogenesis of chronic HBV and further indicate that ZFP36 may be an important target for anti-inflammatory therapy during chronic HBV infection.

[Elastic modulus of small intestinal submucosa].

OBJECTIVE: to determine the modulus of elasticity (E) of small intestinal submucosa (SIS), a new biological graft material. METHODS: The longitudinal tensile testing was performed on 21 specimens of canine jejunum with the electronic material test machine. RESULTS: Stress (sigma)-strain (epsilon) data were obtained. It was found that the stress (sigma)-strain (epsilon) data fitted the expression sigma = Kiepsilon(alpha) very well, the mean correlation coefficients R2 was 0. 991 6. Then the expression of the modulus of elasticity (E) of SIS was E=K(1/alpha)sigma(1-1/alpha). The mean values of alpha and K were 3.966 9 and 374.55, so E = 4.3992sigma(0.75). CONCLUSION: The modulus of elasticity was found to increase with increasing stress. The variations law is similar to that of the vessels. Furthermore when sigma is 0.01333 MPa (100 mmHg), E is about 0.16 MPa, which is similar to that of the vessels.