SEPS1 protects RAW264.7 cells from pharmacological ER stress agent-induced apoptosis

Selenoprotein S (SEPS1) is a novel endoplasmic reticulum (ER) resident protein and it is known to play an important role in production of inflammatory cytokines. Here, we show evidence that SEPS1 is stimulated by pharmacological ER stress agents in RAW264.7 macrophages as well as other cell types. Overexpression studies reveal a protective action of SEPS1 in macrophages against ER stress-induced cytotoxicity and apoptosis, resulting in promoting cell survival during ER stress. The protective action of SEPS1 is largely dependent on ER stress-mediated cell death signal with less effect on non-ER stress component cell death signals. Conversely, suppression of SEPS1 in macrophages results in sensitization of cells to ER stress-induced cell death. These findings suggest that SEPS1 could be a new ER stress-dependent survival factor that protects macrophage against ER stress-induced cellular dysfunction.

Photothermally induced apoptosis of cancer cells using gold nanorods for low energy cancer therapy

Gold nanorods functionalised with transferrin were used for photothermally induced necrosis and apoptosis of cancer cells. It was observed that the laser energy required to induce cell apoptosis is significantly lower than that for cell necrosis, indicating that photothermally induced apoptosis can be used for medically safe laser cancer treatment.

Dynamic analysis of drug-induced cytotoxicity using chip-based dielectrophoretic cell immobilization technology

Quantification of programmed and accidental cell death provides useful end-points for the anticancer drug efficacy assessment. Cell death is, however, a stochastic process. Therefore, the opportunity to dynamically quantify individual cellular states is advantageous over the commonly employed static, end-point assays. In this work, we describe the development and application of a microfabricated, dielectrophoretic (DEP) cell immobilization platform for the realtime analysis of cancer drug-induced cytotoxicity. Microelectrode arrays were designed to generate weak electro-thermal vortices that support efficient drug mixing and rapid cell immobilization at the delta-shape regions of strong electric field formed between the opposite microelectrodes. We applied this technology to the dynamic analysis of hematopoietic tumor cells that represent a particular challenge for real-time imaging due to their dislodgement during image acquisition. The present study was designed to provide a comprehensive mechanistic rationale for accelerated cell-based assays on DEP chips using real-time labeling with cell permeability markers. In this context, we provide data on the complex behavior of viable vs dying cells in the DEP fields and probe the effects of DEP fields upon cell responses to anticancer drugs and overall bioassay performance. Results indicate that simple DEP cell immobilization technology can be readily applied for the dynamic analysis of investigational drugs in hematopoietic cancer cells. This ability is of particular importance in studying the outcome of patient derived cancer cells, when exposed to therapeutic drugs, as these cells are often rare and difficult to collect, purify and immobilize.

A novel mechanism of CD40-induced apoptosis of carcinoma cells involving TRAF3 and JNK/AP-1 activation

Membrane-presented CD40 agonists can induce apoptosis in carcinoma, but not normal homologous epithelial cells, whereas soluble agonists are growth inhibitory but not proapoptotic unless protein synthesis is blocked. Here we demonstrate that membrane-presented CD40 ligand (CD154) (mCD40L), but not soluble agonists, triggers cell death in malignant human urothelial cells via a direct mechanism involving rapid upregulation of TNFR-associated factor (TRAF)3 protein, without concomitant upregulation of TRAF3 mRNA, followed by activation of the c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway and induction of the caspase-9/caspase-3-associated intrinsic apoptotic machinery. TRAF3 knockdown abrogated JNK/AP-1 activation and prevented CD40-mediated apoptosis, whereas restoration of CD40 expression in CD40-negative carcinoma cells restored apoptotic susceptibility via the TRAF3/AP-1-dependent mechanism. In normal human urothelial cells, mCD40L did not trigger apoptosis, but induced rapid downregulation of TRAF2 and 3, thereby paralleling the situation in B-lymphocytes. Thus, TRAF3 stabilization, JNK activation and caspase-9 induction define a novel pathway of CD40-mediated apoptosis in carcinoma cells.

Cancer targeted nanoparticles specifically induce apoptosis in cancer cells and spare normal cells

Curing cancer is the greatest challenge for modern medicine and finding ways to minimize the adverse effects caused by chemotherapeutic agents is of importance in improving patient’s physical conditions. Traditionally, chemotherapy can induce various adverse effects, and these effects are mostly caused by the non-target specific properties of the chemotherapeutic compounds. Recently, the use of nanoparticles has been found to be capable of minimizing these drug-induced adverse effects in animals and in patients during cancer treatment. The use of nanoparticles allows various chemotherapeutic drugs to be targeted to cancer cells with lower dosages. In addition to this, the use of nanoparticles also allows various drugs to be administered to the subjects by an oral route. Here, locked nucleic acid (LNA)-modified epithelial cell adhesion molecules (EpCAM), aptamers (RNA nucleotide), and nucleolin (DNA nucleotide) aptamers have been developed and conjugated on anti-cancer drug-loaded nanocarriers for specific delivery to cancer cells and spare normal cells. Significant amounts of the drug loaded nanocarriers (92 ± 6 %) were found to distribute to the cancer cells at the tumour site and more interestingly, normal cells were unaffected in vitro and in vivo. In this review, the benefits of using nanoparticle-coated drugs in various cancer treatments are discussed. Various nanoparticles that have been tried in improving the target specificity and potency of chemotherapeutic compounds are also described.

Novel protein and atenolol co-encapsulated nanocapsules to impede cardiomyocyte apoptosis

 The research conducted was based on regenerating the dying heart cells (cardiomyocytes) by employing novel therapeutic proteins and their respective co-encapsulated nanoformulation with an antihypertensive drug. This promising therapeutic strategy to revive the heart can help in the treatment of several cardiac pathologies such as myocardial infarction and drug induced cardiotoxicity.

Diesel exhaust particulate matter induces multinucleate cells and zinc transporter-dependent apoptosis in human airway cells

The cellular effects of biodiesel emissions particulate matter (BDEP) and petroleum diesel emissions particulate matter (PDEP) were compared using a human airway cell line, A549. At concentrations of 25 µg/ml, diesel particulate matter induced the formation of multinucleate cells. In cells treated with a mixture of 80% PDEP:20% BDEP, 52% of cells were multinucleate cells compared with only 16% of cells treated with 20% PDEP:80% BDEP with a background multinucleate rate of 7%. These results demonstrate a causal relation between the formation of multinucleate cells and exposure to exhaust particulate matter, in particular diesel exhaust. Exposure of A549 cells to PDEP induced apoptosis, seen by active caspase-3 expression and the presence of cleaved pancytokeratin. PDEP exhaust was a much stronger inducer of cellular death through apoptosis than BDEP. There was an eightfold increase in the expression of SLC30A3 (zinc transporter-3 or ZnT3) in cells exposed to 80% PDEP:20% BDEP compared to untreated cells. The increase in ZnT3 expression seen in apoptotic cells following PDEP suggests a role for this zinc transporter in the apoptotic pathway, possibly through controlling zinc fluxes. As exposure to diesel exhaust particles is associated with asthma and apoptosis in airway cells, diesel exhaust particles may directly contribute to asthma by inducing epithelial cell death through apoptotic pathway.

RTKN2 induces NF-KappaB dependent resistance to intrinsic apoptosis in HEK cells and REgulates BCL-2 genes in human CD4+ lymphocytes

The gene for Rhotekin 2 (RTKN2) was originally identified in a promyelocytic cell line resistant to oxysterol-induced apoptosis. It is differentially expressed in freshly isolated CD4+ T-cells compared with other hematopoietic cells and is down-regulated following activation of the T-cell receptor. However, very little is known about the function of RTKN2 other than its homology to Rho-GTPase effector, rhotekin, and the possibility that they may have similar roles. Here we show that stable expression of RTKN2 in HEK cells enhanced survival in response to intrinsic apoptotic agents; 25-hydroxy cholesterol and camptothecin, but not the extrinsic agent, TNFα. Inhibitors of NF-KappaB, but not MAPK, reversed the resistance and mitochondrial pro-apoptotic genes, Bax and Bim, were down regulated. In these cells, there was no evidence of RTKN2 binding to the GTPases, RhoA or Rac2. Consistent with the role of RTKN2 in HEK over-expressing cells, suppression of RTKN2 in primary human CD4+ T-cells reduced viability and increased sensitivity to 25-OHC. The expression of the pro-apoptotic genes, Bax and Bim were increased while BCL-2 was decreased. In both cell models RTKN2 played a role in the process of intrinsic apoptosis and this was dependent on either NF-KappaB signaling or expression of downstream BCL-2 genes. As RTKN2 is a highly expressed in CD4+ T-cells it may play a role as a key signaling switch for regulation of genes involved in T-cell survival.

Bone marrow chimeras and c-fms conditional ablation (mafia) mice reveal an essential role for resident myeloid cells in lipopolysaccharide/TLR4-induced corneal inflammation

The mammalian cornea contains an extensive network of resident macrophages and dendritic cells. To determine the role of these cells in LPS-induced corneal inflammation, TLR4−/− mice were sublethally irradiated and reconstituted with bone marrow cells from either enhanced GFP (eGFP)+/C57BL/6 or eGFP+/TLR4−/− mice. The corneal epithelium was abraded, LPS was added topically, and cellular infiltration to the corneal stroma and development of corneal haze were examined after 24 h. TLR4−/− mice reconstituted with C57BL/6, but not TLR4−/− bone marrow cells donor cells were found to cause infiltration of eGFP+ cells to the cornea, including neutrophils, and also increased corneal haze compared with saline-treated corneas. In a second experimental approach, corneas of transgenic macrophage Fas induced apoptosis (Mafia) mice were stimulated with LPS. These mice express eGFP and a suicide gene under control of the c-fms promoter, and systemic treatment with the FK506 dimerizer (AP20187) causes Fas-mediated apoptosis of monocytic cells. AP20187-treated mice had significantly fewer eGFP+ cells in the cornea than untreated mice. After stimulation with LPS neutrophil recruitment and development of corneal haze were impaired in AP20187-treated mice compared with untreated controls. Furthermore, LPS induced CXCL1/KC and IL-1α production within 4 h in corneas of untreated Mafia mice, which is before cellular infiltration; however, cytokine production was impaired after AP20187 treatment. Together, results from both experimental approaches demonstrate an essential role for resident corneal monocytic lineage cells (macrophages and dendritic cells) in development of corneal inflammation.

The mechanisms of Chansu in inducing efficient apoptosis in colon cancer cells

Chansu is one of the most widely used traditional Chinese medicines in China, Japan, and other Southeast Asian countries primarily for antipain, anti-inflammation, and recently anticancer. Over 10 recipes and remedies contained Chansu, which are easily available in pharmacies and hospitals, but the mechanisms of action were not clearly articulated. In the present study, Cinobufagin (CBF), the major compound of Chansu, was employed as a surrogate marker to determine its ability in inducing cancer cell death. As expected, CBF has significant cancer-killing capacity for a range of cancers, but such ability differs markedly. Colon and prostate cancers are more sensitive than skin and lung cancers. Interestingly, cancer cells die through apoptotic pathway either being biphasic caspase- 3-dependent (HCT116) or independent (HT29). Multipathway analysis reveals that CBF-induced apoptosis is likely modulated by the hypoxia-inducing factor-1 alpha subunit (HIF-1

Efficacy of nefazodone in the treatment of neuroleptic induced extrapyramidal side effects: a double-blind randomised parallel group placebo-controlled trial.

Many atypical antipsychotics show antagonism at both serotonergic and dopaminergic neurones and show fewer extrapyramidal side effects (EPS). Nefazodone blocks postsynaptic 5HT2A receptors and weakly inhibits serotonin reuptake. This study aimed to elucidate the role of nefazodone in the treatment of antipsychotic-induced EPS. The trial was a double-blind, randomised, placebo-controlled trial of patients requiring antipsychotic treatment with haloperidol 10mg daily; from which a subgroup of patients who developed EPS were selected for the study. Patients were randomised to add-on therapy with either placebo (n=24) or nefazodone (n=25) 100mg bd. EPS were measured on days 0, 3 and 7 using the Simpson Angus, Barnes akathisia, abnormal involuntary movement and Chouinard scales. Nefazodone significantly reduced EPS as measured by both the Simpson Angus scale and CGI (p=0.007 and 0.0247, respectively). Akathisia and tardive dyskinesia did not differ between the two groups (p=0.601; p=0.507, respectively). These results suggest the role of 5HT2 antagonism in the mechanism of action of atypical antipsychotics with respect to lowering rates of drug-induced EPS. In addition, a therapeutic role for nefazodone is suggested in the treatment of antipsychotic-induced EPS.

Epigallocatechin-3-gallate induces the apoptosis of hepatocellular carcinoma LM6 cells but not non-cancerous liver cells

Epigallocatechin-3-gallate (EGCG) is a constituent of green tea and has been associated with anticancer activity. In the present study, the inhibitory effect of EGCG on human hepatocellular cancer cells was examined by cell viability assay, in vitro apoptosis assay and cell cycle analysis. In addition, gene expression was measured to elucidate the molecular mechanisms of action of EGCG by mitochondrial membrane potential (MMP) determination and western blot analysis. We demonstrated that EGCG induced apoptosis, decreased mitochondrial membrane potential and promoted G0/G1 phase cell cycle arrest of HCCLM6 cells but not that of non-cancerous liver cells (HL-7702). The EGCG-induced apoptosis of HCCLM6 cells was associated with a significant decrease in Bcl-2 and NF-κB expression. In addition, the expression of Bax, p53, caspase-9 and caspase-3 increased, and cytochrome c was released. These results suggest that EGCG inhibits the progression of cancer through cytocidal activity and that it is a potential therapeutic compound for hepatocellular carcinoma (HCC).