Prospectus, September 22, 1982

STUDENT VOTE SHOULD BE EXERCISED; News Digest; Election candidates present platforms; Children\u27s theater group performs new play; College remark causes reaction; Annex gets approval; C-U Happenings…; Club designed for business students; Bike is victim of \u27dastardly deed\u27; Microprecision department one of few in U.S.; Hough now teaches class; Community Calendar; Classified; Problem lyrics can\u27t overshadow great music; Hot Country Singles; TV season may bring surprises; TH\u27s delight CU at AH; Abbey\u27s job has variety; White leads for Parkland; ISU transfer looks like an asset; Fast Freddy Contesthttps://spark.parkland.edu/prospectus_1982/1010/thumbnail.jp

HSP90 and eNOS partially co-localize and change cellular localization in relation to different ECM components in 2D and 3D cultures of adult rat cardiomyocytes.

Background information. Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM chemistry and mechanics on the cellular localization of two interacting signalling proteins: HSP90 (heat-shock protein of 90 kDa) and eNOS (endothelial nitric oxide synthase). Results. Freshly isolated rat cardiomyocytes were cultured on fibronectin, Matrigel gel or laminin, or in co-culture with cardiac fibroblasts, and tested for both integrity and viability. As validation criteria, integrity of both plasma membrane and mitochondria was evaluated by transmission electron microscopy. Cell sensitivity to microenvironmental stimuli was monitored by immunofluorescence and confocal microscopy. We found that HSP90 and eNOS expression and localization are affected by changes in ECM composition. Elaboration of the images revealed, on Matrigel-cultured cardiomyocytes, areas of high co-localization between HSP90 and eNOS and co-localization coefficients, which indicated the highest correlation with respect to the other substrates. Conclusions. Our three-dimensional adult cardiomyocyte cultures are suitable for both analysing cell–ECM interactions at electron and confocal microscopy levels and monitoring micro-environment impact on cardiomyocyte phenotype

Effects of Mycobacterium bovis BCG Infection on Regulation of l-Arginine Uptake and Synthesis of Reactive Nitrogen Intermediates in J774.1 Murine Macrophages

The generation of nitric oxide (NO) by activated macrophages is believed to control mycobacterial infection in the murine system. In this study we examined the effect of Mycobacterium bovis BCG infection on the l-arginine-dependent NO pathway in J774.1 murine macrophages. We have confirmed previous results by demonstrating that stimulation of J774.1 with lipopolysaccharide (LPS) and gamma interferon (IFN-γ) results in an increase in the uptake of (3)H-labeled l-arginine and a concomitant increase in the production of NO. We have also shown that BCG can mimic LPS treatment, leading to enhanced l-[(3)H]arginine uptake by IFN-γ-stimulated macrophages. Lipoarabinomannan, a component of the BCG cell wall that is structurally similar to LPS, is not responsible for the uptake stimulation in IFN-γ stimulated macrophages. Although we demonstrated that there was a 2.5-fold increase in NO production by macrophages 4 h after LPS–IFN-γ stimulation, BCG infection (with or without IFN-γ stimulation) did not lead to the production of NO by the macrophages by 4 h postinfection. At 24 h postinfection, the infected macrophages that were stimulated with IFN-γ produced amounts of NO similar to those of macrophages stimulated with LPS–IFN-γ. This suggests that there are multiple regulatory pathways involved in the production of NO. Finally, our data suggest that increased expression of the arginine permease, MCAT2B, after 4 h of LPS–IFN-γ treatment or BCG infection–IFN-γ treatment is not sufficient to account for the increases in l-[(3)H]arginine uptake detected. This suggests that the activity of the l-arginine transporter(s) is also altered in response to macrophage activation