Benzalkonium chloride (BAK) induces apoptosis or necrosis, but has no major influence on the cell cycle of Jurkat cells

Benzalkonium chloride (BAK) is a cationic detergent with a very slow turnover. Because of its strong antibacterial activities, BAK is widely used especially in dentistry and ophthalmology. It is the most commonly used preservative in topical ophthalmic medications. Due to chronicity and widespread use of such treatments, BAK’s side effects are of great importance. BAK toxicity for adherent cells, probably related to its pro-oxidative activities, is time- and dose-dependent. Although lymphocytes often infiltrate superficial eye tissues, the BAK influence on them is yet to be established. The aim of this study was to check BAK cytotoxicity on T lymphocytic Jurkat line cells and to verify the suggestion that BAK can induce G2M cell blocks. A dose- and time-dependent cytotoxic effect of BAK on lymphoid cells in relatively low concentrations was shown in this study. In lower concentrations, it shows a moderate apoptotic and minimal antiproliferative effect on Jurkat cells, while in higher concentrations it shows a rapid necrotic effect. No G2M cell blocks were observed. Our findings could suggest lymphoid dysfunction during intensive, prolonged topical BAK treatment, even at dosages relatively non-toxic to epithelial eye cells. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 225–230

Benzalkonium chloride (BAK) induces apoptosis or necrosis, but has no major influence on the cell cycle of Jurkat cells

Benzalkonium chloride (BAK) is a cationic detergent with a very slow turnover. Because of its strong antibacterial activities, BAK is widely used especially in dentistry and ophthalmology. It is the most commonly used preservative in topical ophthalmic medications. Due to chronicity and widespread use of such treatments, BAK’s side effects are of great importance. BAK toxicity for adherent cells, probably related to its pro-oxidative activities, is time- and dose-dependent. Although lymphocytes often infiltrate superficial eye tissues, the BAK influence on them is yet to be established. The aim of this study was to check BAK cytotoxicity on T lymphocytic Jurkat line cells and to verify the suggestion that BAK can induce G2M cell blocks. A dose- and time-dependent cytotoxic effect of BAK on lymphoid cells in relatively low concentrations was shown in this study. In lower concentrations, it shows a moderate apoptotic and minimal antiproliferative effect on Jurkat cells, while in higher concentrations it shows a rapid necrotic effect. No G2M cell blocks were observed. Our findings could suggest lymphoid dysfunction during intensive, prolonged topical BAK treatment, even at dosages relatively non-toxic to epithelial eye cells. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 225–230

Application of primary cell cultures of laryngeal carcinoma and laser scanning cytometry in the evaluation of tumor reactivity to cisplatinum.

Unsatisfactory effects of treatment of laryngeal carcinoma patients stimulate the clinicians as well as researchers to develop new more effective treatment models and to find new reliable prognostic factors. The aim of the present study was the evaluation of the use of primary cell cultures of the laryngeal carcinoma and laser scanning cytometry (LSC) in the assessment of tumor reactivity to cisplatinum. Nineteen primary cultures of laryngeal carcinoma cells established from fragments of laryngeal carcinoma infiltrations were cultured with or without cisplatin, stained with monoclonal antibodies against P53 and BCL-2 proteins and analyzed by LSC. Cisplatin added to the culture medium leads to the significant increase of P53 expression and decrease of BCL-2 expression. Moreover, changes of P53 and BCL-2 expressions were significantly correlated. Our findings of apoptosis regulatory mechanisms could be useful in patient qualification for the chemotherapeutic follow-up treatment

Proteomic analysis of cell cycle progression in asynchronous cultures, including mitotic subphases, using PRIMMUS

AbstractThe temporal regulation of protein abundance and post-translational modifications is a key feature of cell division. Recently, we analysed gene expression and protein abundance changes during interphase under minimally perturbed conditions (Ly et al. 2014; Ly et al. 2015). Here we show that by using specific intracellular immunolabeling protocols, FACS separation of interphase and mitotic cells, including mitotic subphases, can be combined with proteomic analysis by mass spectrometry. Using this PRIMMUS (PRoteomic analysis of Intracellular iMMUnolabeled cell Subsets) approach, we now compare protein abundance and phosphorylation changes in interphase and mitotic fractions from asynchronously growing human cells. We identify a set of 115 phosphorylation sites increased during G2, which we term ‘early risers’. This set includes phosphorylation of S738 on TPX2, which we show is important for TPX2 function and mitotic progression. Further, we use PRIMMUS to provide a proteome-wide analysis of protein abundance remodeling between prophase, prometaphase and anaphase.</jats:p

The effect of Propionibacterium acnes on maturation of dendritic cells derived from acne patients' peripherial blood mononuclear cells.

Propionibacterium acnes (P. acnes) has been implicated in the pathogenesis of acne vulgaris which is the most common cutaneous disorder. It has a proinflammatory activity and takes part in immune reactions modulating the Th1/Th2 cellular response. The exposure of dendritic cells (DCs) to whole bacteria, their components, cytokines or other inflammatory stimuli and infectious agents induces differentiation from immature DCs into antigen-presenting mature DCs. The aim of the study was to evaluate the capability of P. acnes to induce the maturation of DCs. We stimulated monocyte derived dendritic cells (Mo-DCs) from acne patients with various concetrations of heat-killed P. acnes (10(6)-10(8) bacteria/ml) cultured from acne lesions. The results showed an increase in CD80+/CD86+/DR+ and CD83+/CD1a+/DR+ cells percentage depending on the concetration of P. acnes. The expression of CD83 and CD80 (shown as the mean fluorescence intensity - MFI) increased with higher concetrations of P. acnes. There were also significant correlations between MFI of CD83, CD80, CD86 and concetration of P. acnes. The study showed that P. acnes in the concetration of 10(8) bacteria/ml is most effective in the induction of Mo-DCs maturation. Futher studies concerning the influence on the function of T cells are needed

Altered cytological parameters in buccal cells from individuals with mild cognitive impairment and Alzheimer\u27s disease

Previous studies have shown that mild cognitive impairment (MCI) may be reflective of the early stages of more pronounced neurodegenerative disorders such as Alzheimer\u27s disease (AD). There is a need for a minimally invasive and inexpensive diagnostic to identify those who exhibit cellular pathology indicative of MCI and AD risk so that they can be prioritized for primary preventative measures. The hypothesis was that a minimally invasive approach using cytological markers in isolated buccal mucosa cells can be used to identify individuals of both MCI and AD. An automated buccal cell assay was developed using laser scanning cytometry (LSC) to measure buccal cell type ratios, nuclear DNA content and shape, and neutral lipid content of buccal cells from clinically diagnosed AD (n=13) and MCI (n=13) patients prior to treatment compared to age- and gender-matched controls (n=26). DNA content was significantly higher in all cell types in both MCI (P2N nuclei. Abnormal nuclear shape (circularity) was significantly increased in transitional cells in MCI (

Biologic predictors of extension of oligoarticular juvenile idiopathic arthritis as determined from synovial fluid cellular composition and gene expression

Objective. To identify biomarkers in the first synovial fluid (SF) aspirate obtained from children with oligoarticular juvenile idiopathic arthritis (JIA), which could be used to identify children whose disease is likely to extend to a more severe phenotype.Methods. Patients with recent-onset oligoarticular JIA were identified and grouped according to those whose mild disease persisted (persistent disease) or those whose disease would extend from a mild to more severe phenotype (extended-to-be disease) at 1 year after diagnosis. Flow cytometry was used to delineate differences in the mononuclear cell populations between the first blood sample and first SF aspirate from the same patient and between outcome (persistent versus extended-to-be) groups. Proportions of lymphocytes in the joint were modeled on chemotaxis of lymphocytes to CCL5, using Transwell migration assays. Levels of CCL5 in the SF were quantified by enzyme-linked immunosorbent assay. RNA profiles of SF mononuclear cells were compared between groups using the Affymetrix GeneChip hybridization protocol and hierarchical clustering analyses.Results. Compared with peripheral blood mononuclear cells, SF mononuclear cells displayed an expansion of CD8+ T cells, reduced proportion of B cells, and expansion of CD16- natural killer cells. The lower CD4:CD8 ratio in the SF was recapitulated in vitro by the observed migration of blood T cells in response to CCL5. Synovial CCL5 levels were higher in children whose disease extended to a more severe phenotype. The CD4: CD8 ratio in the SF was significantly lower in patients with extended-to-be oligoarticular JIA (0.57 compared with 0.90 in the persistent disease group, difference 0.33, 95% confidence interval 0.04-0.62; P = 0.009). Gene expression profiling revealed that 344 genes were > 1.5-fold differentially expressed between outcome groups (P < 0.05), and these included genes associated with inflammation and macrophage differentiation, which showed increased levels in patients with extended disease at 1 year, and genes associated with immune regulation, which showed increased levels in patients with persistent disease at 1 year.Conclusion. Analyses of the proportions of synovial lymphocytes, levels of CCL5, and differential gene expression yielded potential biomarkers with which to predict the likelihood of extension of oligoarticular JIA to a more severe disease phenotype

New Biomarkers Probing Depth of Cell Senescence Assessed by Laser Scanning Cytometry

The imaging analytical capabilities of laser scanning cytometer (LSC) have been used to assess morphological features considered to be typical of the senescent phenotype. The characteristic “flattening” of senescent cells was reflected by the decline in the density of staining (intensity of maximal pixel) of DNA-associated fluorescence [4,6-diamidino-2-phenylindole (DAPI)] paralleled by an increase in nuclear size (area). The decrease in ratio of maximal pixel to nuclear area was even more sensitive senescence biomarker than the change in maximal pixel or nuclear area, each alone. The saturation cell density at plateau phase of growth recorded by LSC was found to be dramatically decreased in cultures of senescent cells, thereby also serving as an additional marker. The induction of cyclin dependent kinase inhibitors p21WAF1 and p27KIP1 and γH2AX and activation of ATM markers of DNA damage response were measured in parallel with DNA/DAPI maximal pixel and nuclear area. These biomarker indices were expressed in quantitative terms by reporting them as a fraction of the respective controls. The effect of treatment of A549 and WI-38 cells with different concentrations of mitoxantrone (Mxt) and trichostatin A for various time periods was studied to assess the degree (depth) of cell senescence. Also assessed was the effect of 2-deoxy-d-glucose, the agent attenuating metabolic cell activity, on the depth of senescence induced by Mxt. A relationship between the ability of cells to synthesize RNA (incorporate 5-ethynyluridine) that leads to growth imbalance and induction of cell senescence was also studied. The data show that morphometric analysis of cellular attributes by LSC offers an attractive tool to detect cell senescence and measure its degree particularly in assessing effects of the factors that enhance or attenuate this process. This methodology is of importance in light of the evidence that cellular senescence is not only a biological process that is fundamental for organismal aging but also impedes formation of induced-pluripotent stem cells providing the barrier for neoplastic transformation and is the major mechanism of induction of reproductive cell death during treatment of solid tumors. © 2010 International Society for Advancement of Cytometry

Cyclophosphamide Chemotherapy Sensitizes Tumor Cells to TRAIL-Dependent CD8 T Cell-Mediated Immune Attack Resulting in Suppression of Tumor Growth

Background: Anti-cancer chemotherapy can be simultaneously lymphodepleting and immunostimulatory. Pre-clinical models clearly demonstrate that chemotherapy can synergize with immunotherapy, raising the question how the immune system can be mobilized to generate anti-tumor immune responses in the context of chemotherapy. Methods and Findings: We used a mouse model of malignant mesothelioma, AB1-HA, to investigate T cell-dependent tumor resolution after chemotherapy. Established AB1-HA tumors were cured by a single dose of cyclophosphamide in a CD8 T cell- and NK cell-dependent manner. This treatment was associated with an IFN-α/β response and a profound negative impact on the anti-tumor and total CD8 T cell responses. Despite this negative effect, CD8 T cells were essential for curative responses. The important effector molecules used by the anti-tumor immune response included IFN-γ and TRAIL. The importance of TRAIL was supported by experiments in nude mice where the lack of functional T cells could be compensated by agonistic anti-TRAIL-receptor (DR5) antibodies. Conclusion: The data support a model in which chemotherapy sensitizes tumor cells for T cell-, and possibly NK cell-, mediated apoptosis. A key role of tumor cell sensitization to immune attack is supported by the role of TRAIL in tumor resolution and explains the paradox of successful CD8 T cell-dependent anti-tumor responses in the absence of CD8 T cell expansion

Eliminating caspase-7 and cathepsin B cross-reactivity on fluorogenic caspase-3 substrates

11 FRET-based fluorogenic substrates were constructed using the pentapeptide template Asp-Glu-X(2)-Asp-X(1)′, and evaluated with caspase-3, caspase-7 and cathepsin B. The sequence Asp-Glu-Pro-Asp-Ser was able to selectively quantify caspase-3 activity in vitro without notable caspase-7 and cathepsin B cross-reactivity, while exhibiting low μM K (M) values and good catalytic efficiencies (7.0–16.9 μM(–1) min(–1))