Characteristics of macrophage activation by gamma interferon for tumor cytotoxicity in peritoneal macrophages and macrophage cell line J774.1

Involvement of Expression of miR33-5p and ABCA1 in Human Peripheral Blood Mononuclear Cells in Coronary Artery Disease

MicroRNAs (miRs) are small non-coding RNAs that regulate gene expression post-transcriptionally and are crucial in lipid metabolism. ATP-binding cassette transporter A1 (ABCA1) is essential for cholesterol efflux from cells to high-density lipoprotein (HDL). Dysregulation of miRs targeting ABCA1 can affect cholesterol homeostasis and contribute to coronary artery disease (CAD). This study aimed to investigate the expression of miRs targeting ABCA1 in human monocytes, their role in cholesterol efflux, and their relationship with CAD. We included 50 control and 50 CAD patients. RT-qPCR examined the expression of miR-33a-5p, miR-26a-5p, and miR-144-3p in monocytes. Logistic regression analysis explored the association between these miRs and CAD. HDL's cholesterol acceptance was analyzed using the J774A.1 cell line. Results showed that miR-26a-5p (p = 0.027) and ABCA1 (p = 0.003) expression levels were higher in CAD patients, while miR-33a-5p (p < 0.001) levels were lower. Downregulation of miR-33a-5p and upregulation of ABCA1 were linked to a lower CAD risk. Atorvastatin upregulated ABCA1 mRNA, and metformin downregulated miR-26a-5p in CAD patients. Decreased cholesterol efflux correlated with higher CAD risk and inversely with miRs in controls. Reduced miR-33a-5p expression and increased ABCA1 expression are associated with decreased CAD risk. miR deregulation in monocytes may influence atherosclerotic plaque formation by regulating cholesterol efflux. Atorvastatin and metformin could offer protective effects by modulating miR-33a-5p, miR-26a-5p, and ABCA1, suggesting potential therapeutic strategies for CAD prognosis and treatment.

Comparative evaluation of plant extract effects on peritoneal, medullary and J774 cells. G8 macrophages

The use of medicinal plants as raw material for extracts production and pure substances isolation and subsequence development of new drugs represents a constantly growing area. However, some stages are indispensable before pharmacologically evaluating natural products such as medicines. Toxicity tests in mammalian cells are essential to initiate new drugs development or verify the substance's biocompatibility. Thus, we verified the toxicity of crude extracts and fractions with different polarities obtained from the leaves and stems of eight plant species. The toxic effect was evaluated on macrophages obtained from the bone marrow and peritoneal cavity of a Swiss webster mouse and J774 macrophages. G8 cell lineage. These macrophages were cultured in a 96-well plate, and the compounds were added at a concentration of 100 µg/mL for 24 hours. After this time, the supernatant was removed. The toxicity was evaluated for lactate dehydrogenase (LDH) release assay and the resazurin assay, which uses an indicator dye to measure oxidation-reduction reactions. The results showed a difference in the percentage of toxicity when comparing the same extract in different types of macrophages. This outcome indicates that these cells from different origins may exhibit different responses when exposed to the same natural compounds.

Characterization of influenza virus-induced death of J774.1 macrophages

The mechanism and role of influenza virus (IV)-induced pathogenesis of macrophages during respiratory infection are ill defined. Reported here are findings on IV-induced cytopathic effects (CPEs) for an in vitro experimental system using the murine macrophage cell line J774.1. CPE was elicited by 0.2 or greater multiplicity of infection (m.o.i.). CPEs showed a lag of 6-8 h postinfection and occurred most rapidly between 6 and 12 h. J774.1 cells did not support productive IV replication, but immunofluorescence demonstrated that IV protein synthesis occurred. Light microscopy and DNA staining showed that after death cells had very condensed cytoplasm and nuclei. Cell remnants were surrounded by intact plasma membrane (PM) as demonstrated by exclusion of a membrane-impermeant dye. Time-lapse video microscopy recordings between 6 and 10 h postinfection showed sequential structural changes, including previously undescribed events. Notable changes were a rapid cytokinesis (zeiosis; "cell boiling"), followed by nuclear shrinkage, and an unusual transient blebbing of the PM. DNA fragmentation occurred after 12 h, producing a wide size range. UV-inactivated virus failed to induce CPEs, and CPE was blocked by amantadine. N-Acetylcysteine and pyrrolidine dithiocarbamate, but not other inhibitors of reactive oxygen intermediates, reduced or blocked the CPE. Most changes observed are those attributed to apoptotic processes rather than necrotic cell death. The kinetics and inhibitor effects suggest that IV infection and replication must be initiated to activate CPEs.

Role of specific determinants in mannan of Candida albicans serotype A in adherence to human buccal epithelial cells

Candida albicans serotype A (C. albicans A) possesses a specific antigen, designated antigen 6, which resides in mannans on the cell surface. To determine the role of the mannan moiety of the C. albicans cell wall in adherence to buccal epithelial cells, we used antigen 6-deficient mutants which had been isolated by screening with an agglutinating monoclonal antibody against antigen 6 (MAb-6). 1H nuclear magnetic resonance spectral analysis of the purified mannans from the mutants showed a loss of the signals related to that beta-linkage of the side chains. Moreover, acetolyzed fragments of the mutant mannans showed a decreased amount of mannohexaose and mannopentaose. The mutant yeast cells exhibited significantly reduced ability to adhere both to exfoliated buccal epithelial cells and to a human buccal cell line. A number of strains of C. albicans A, C. tropicalis, and C. glabrata, all of which bear antigen 6, showed significantly higher adherence to the cell line than did those of C. albicans serotype B, which lack antigen 6. The whole mannan from the C. albicans A parent inhibited the adherence of C. albicans A to epithelial cells dose dependently, whereas mannan from a mutant strains did not. Moreover, C. albicans A treated with MAb-6 or polyclonal factor 6 serum showed reduced adherence. A close correlation was found between adhesive ability and agglutinability with MAb-6 in the C. albicans A parent, the antigenic mutants, and their spontaneous revertants. These results suggest that so far as mannan adhesion is concerned, serotype A-specific determinants are largely involved in the mechanisms of adherence of C. albicans A to human buccal epithelial cells.