Expression and proteolytic activity of calpain in lens epithelial cells of oxidative cataract

INTRODUCTION The association between oxidative stress andcataract formation is well known from both clinicaland experimental data. The mechanism throughwhich oxidative stress causes cataract has not yetbeen established. It is known that many kinds ofcataract are related to increased levels of calcium.This has raised interest in the involvement of cal-cium-activated proteases. Calpains are non-lysosomal, cysteine prote-ases activated by calcium, which are found in mostmammalian…     

Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein

INTRODUCTION Senile dementia of the Alzheimer type calledin short Alzheimer’s Disease (AD), is the mostcommon type of senile dementia. The pathologicalcharacters of AD are neuron loss, accumulation of senile lipofuscin pigment (SP) caused by the ex- tracellular deposition of Amyloid beta-Protein (Aβ) and neurofibrillary tangles (NFT) caused by ac-t cumulation of excessively …     

Homoharringtonine induces apoptosis of endothelium and down-regulates VEGF expression of K562 cells

INTRODUCTION Homoharringtonine (HHT) is a cephalotoxin alkaloid with anti-leukemic activity and had been used successfully in the treatment of acute and chronic myeloid leukemias (O払rien et al., 1995; 1999; Feldman et al., 1992). The principal mecha-nism of action by HHT is the inhibition of protein synthesis in a dose- and time-dependent manner by binding to ribosome and inhibiting polypeptide chain elongation (Tujebajeva et al., 1989; Zhou et al., 1995). HHT had been shown to indu…     

Numerical investigation of microtexturing rings’ structure on the friction performance of bearing cells

We presented a numerical examination of the effect of microtexturing negative rings’ structure on the tribological performance of parallel bearing couples’ cell. Three mcirotexturing rings, which are circle, square and ellipse, were chosen and the analysis model were established. We used the Reynolds equation coupled with finite difference method and successive over relaxation Gauss-Seidel iterative method to solve the Newtonian flow’s hydrodynamics within a bearing couple. The effect of texture density and radius ratio (thickness) of the microtexturing rings were investigated on the tribological performance under the similar operating conditions. The numerical simulation reveals that: 1) The microtexturing rings’ structure can homogenize the local pressure much uniformly within the bearing cell. 2) The tribological performance is determined mainly by the microtexturing rings’ geometry and texture density, and the thickness of the rings’ structure can help to change the quantitative values. 3) The square and circle rings’s microtexturing surface can slightly improve the frictional performance with the bearing cells’ gap, while the ellipse ring’s surface may decrease the frictional performance. 4) The ellipse rings’ microtexturing surface can achieve the minimum spacing gap but the maximum friction coefficient of the bearing couple, and then the circle and square rings’ structure take the second and third place, respectively     

Cytotoxicity of epigallocatechin-3-gallate to LNCaP cells in the presence of Cu^2＋

Epigallocatechin-3-gallate (EGCG) has shown remarkably anti-cancer activity, with its bioactivity being related to reactive conditions, such as pH and metal ions. The present study investigated the degradation of EGCG and its effect on prostate cancer cell in the presence of Cu2 . EGCG was incubated with prostate cancer cells,     

Brain metastases of melanoma mechanisms of attack on their defence system by engineered stem cells in the microenvironment

This report gives a better emphasis on the role of targeted effectors （e.g. a combination of 5-FC with CD-NSPCs as compared to the application of NSPCs alone） and how such delivery of pro-drug activating enzymes and other tumor-killing substances may overcome melanocytic defence system, interact with and promote the host defence and immune response modulations not only in melanoma but, potentially, in other highly-metastatic cancers.     

Human cytomegalovirus induces alteration of β-actin mRNA and microfilaments in human embryo fibroblast cells

INTRODUCTION It is known that human embryo fibroblast cellsare permissive for cytomegalovirus (CMV) repli-cation in vitro. Data have shown that CMV infec-tion causes a rapid, progressive disruption of thehost cell cytoskeleton (CSK); and that the disrup-tion correlates with actin depolymerization. Someexperts used whole-mount (3D) electron micros-copy to analyze the CSK of uninfected and CMV-infected human lung fibroblast cells; and foundwithin 2 min of CMV infection, localiz…     

Science Letters:Brain metastases of melanoma-mechanisms of attack on their defence system by engineered stem cells in the microenvironment

This report gives a better emphasis on the role of targeted effectors (e.g. a combination of 5-FC with CD-NSPCs as compared to the application of NSPCs alone) and how such delivery of pro-drug activating enzymes and other tumor-killing substances may overcome melanocytic defence system, interact with and promote the host defence and immune response modulations not only in melanoma but, potentially, in other highly-metastatic cancers.     

Immunotherapy of intracranial G422 glioblastoma with dendritic cells pulsed with tumor extract or RNA

Objective: To investigate the anti-tumor efficacy of dendritic cell (DC)-based vaccines pulsed with tumor extracts or RNA in a mouse model of intracranial G422 glioblastoma. Methods: Bone marrow-derived DCs were pulsed ex vivo with tumor extracts or RNA. Ninety female mice harboring 4-day-old intracranial G422 glioblastomas and 126 normal mice were treated with three spaced one week apart subcutaneous injections either with PBS, unpulsed DCs, G422 tumor extracts, RNA, DCs pulsed with G422 tumor extracts (DC/extract) or with RNA (DC/RNA). Seven days after the third immunization of normal mice, the spleens of 36 of them were harvested for cytotoxic T lyphocyte (CTL) assays and the others were challenged in the brain with G422 tumor cells. All the treated mice were followed for survival. Some mice brains were removed and examined pathologically when they died. Results: Immunization using DC/extract or DC/RNA significantly induced G422-specific CTL responses compared with control groups (P<0.01). Vaccinatio     

Cholangiocarcinoma-derived exosomes inhibit the antitumor activity of cytokine-induced killer cells by down-regulating the secretion of tumor necrosis factor-α and perforin

Objective

The aim of our study is to observe the impact of cholangiocarcinoma-derived exosomes on the antitumor activities of cytokine-induced killer (CIK) cells and then demonstrate the appropriate mechanism.

Methods

Tumor-derived exosomes (TEXs), which are derived from RBE cells (human cholangiocarcinoma line), were collected by ultracentrifugation. CIK cells induced from peripheral blood were stimulated by TEXs. Fluorescence-activated cell sorting (FACS) was performed to determine the phenotypes of TEX-CIK and N-CIK (normal CIK) cells. The concentrations of tumor necrosis factor-α (TNF-α) and perforin in the culture medium supernatant were examined by using an enzyme-linked immunosorbent assay (ELISA) kit. A CCK-8 kit was used to evaluate the cytotoxic activity of the CIK cells to the RBE cell line.

Results

The concentrations of TNF-α and perforin of the group TEX-CIK were 138.61 pg/ml and 2.41 ng/ml, respectively, lower than those of the group N-CIK 194.08 pg/ml (P<0.01) and 3.39 ng/ml (P<0.05). The killing rate of the group TEX-CIK was 33.35%, lower than that of the group N-CIK (47.35% (P<0.01)). The population of CD3⁺, CD8⁺, NK (CD56⁺), and CD3⁺CD56⁺ cells decreased in the TEX-CIK group ((63.2±6.8)%, (2.5±1.0)%, (0.53±0.49)%, (0.45±0.42)%) compared with the N-CIK group ((90.3±7.3)%, (65.7±3.3)%, (4.2±1.2)%, (15.2±2.7)%), P<0.01.

Conclusions

Our results suggest that RBE cells-derived exosomes inhibit the antitumor activity of CIK cells by down-regulating the population of CD3⁺, CD8⁺, NK (CD56⁺), and CD3⁺CD56⁺ cells and the secretion of TNF-α and perforin. TEX may play an important role in cholangiocarcinoma immune escape.

     

PI-3 kinase pathway can mediate the effect of TGF-β1 in inducing the expression of SHARP-2 in LLC-PK1 cells

1-3 kinase pathway can mediate this effect.     

Availability and toxicity of Fe(Ⅱ) and Fe(Ⅲ) in Caco-2 cells

The objective of the present study was to compare the toxicity and availability of Fe(Ⅱ) and Fe(Ⅲ) to Caco-2 cells.Cellular damage was studied by measuring cell proliferation and lactate dehydrogenase (LDH) release. The activities of two major antioxidative enzymes [superoxide dismutase (SOD) and glutathione peroxidase (GPx)] and differentiation marker (alkaline phosphatase) were determined after the cells were exposed to different levels of iron salts. The cellular iron concentration was investigated to evaluate iron bioavailability. The results show that iron uptake of the cells treated with Fe(Ⅱ) is significantly higher than that of the cells treated with Fe(Ⅲ) (P＜0.05). Fe(Ⅱ) at a concentration>1.5 mmol/L was found to be more effective in reducing cellular viability than Fe(Ⅲ). LDH release investigation suggests that Fe(Ⅱ) can reduce stability of the cell membrane. The activities of SOD and GPx of the cells treated with Fe(Ⅱ) were higher than those of the cells treated with Fe(Ⅲ), although both of them increased with raising iron supply levels. The results indicate that both Fe(Ⅱ) and Fe(Ⅲ) could reduce the cellular antioxidase gene expression at high levels.     

Allograftic bone marrow-derived mesenchymal stem cells transplanted into heart infarcted model of rabbit to renovate infarcted heart

Objective: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. Materials and Methods: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n=12), heart infarcted model with PBS injection (control group, n=20), sham operation with PBS injection (sham group, n=17). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. Result: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P<0.05)]. Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group     

Antitumor effects of human interferon-alpha 2b secreted by recombinant bacillus Calmette-Guérin vaccine on bladder cancer cells

Objective:Our objective was to construct a recombinant bacillus Calmette-Guérin vaccine(rBCG) that secretes human interferon-alpha 2b(IFNα-2b) and to study its immunogenicity and in vitro antitumor activity against human bladder cancer cell lines T24 and T5637.Methods:The signal sequence BCG Ag85B and the gene IFNα-2b were amplified from the genome of BCG and human peripheral blood,respectively,by polymerase chain reaction(PCR).The two genes were cloned in Escherichia coli-BCG shuttle-vector pMV261 to obtain a new recombinant plasmid pMV261-Ag85B-IFNα-2b.BCG was transformed with the recombinant plasmid by electroporation and designated rBCG-IFNα-2b.Mononuclear cells were isolated from human peripheral blood(PBMCs) and stimulated with rBCG-IFNα-2b or wild type BCG for 3 d,and then cultured with human bladder cancer cell lines T24 and T5637.Their cytotoxicities were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay.Results:BCG was successfully transformed with the recombinant plasmid pMV261-Ag85B-IFNα-2b by electroporation and the recombinant BCG(rBCG-IFNα-2b) was capable of synthesizing and secreting cytokine IFNα-2b.PBMC proliferation was enhanced significantly by rBCG-IFNα-2b,and the cytotoxicity of PBMCs stimulated by rBCG-IFNα-2b to T24 and T5627 was significantly stronger in comparison to wild type BCG.Conclusions:A recombinant BCG,secreting human IFNα-2b(rBCG-IFNα-2b),was constructed successfully and was superior to control wild type BCG in inducing immune responses and enhancing cytotoxicity to human bladder cancer cell lines T24 and T5637.This suggests that rBCG-IFNα-2b could be a promising agent for bladder cancer patients in terms of possible reductions in both clinical dosage and side effects of BCG immunotherapy.