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Curutiu C.,University of Bucharest | Chifiriuc M.C.,University of Bucharest | Iordache F.,Nicolae Simionescu Institute of Cellular Biology and Pathology of the Romanian Academy | Bleotu C.,University of Bucharest | And 5 more authors.
Romanian Journal of Morphology and Embryology | Year: 2014

Intracellular invasion of professional phagocytic cells like monocytes and macrophages by a pathogen usually triggers the apoptosis of the host cells. The aim of this study was to evaluate if Pseudomonas aeruginosa, although not considered a classic intracellular pathogen, could adhere to endothelial cell surface, invade the intracellular compartment and subsequently induce apoptosis of the cells. The adherence and invasion capacity of P. aeruginosa to endothelial cells was monitored using Cravioto's adapted method. The apoptotic cells were evidenced by staining with Acridine orange/Ethidium bromide. The qualitative assay of bacterial adherence to the cellular substrate revealed that all tested strains adhered to endothelial cells surface, exhibiting a diffuse, aggregative or mixed (diffuse-aggregative or localized-aggregative) pattern and 20-70% adherence rates. The adherence of P. aeruginosa induced the reorganization of cytoskeleton filaments and formation of endocytic membrane expansions. Cell free P. aeruginosa culture supernatants did not induce any cell death response, as noticed in case of whole bacterial culture, showing the capacity to induce apoptosis of endothelial cells. The fluorescence microscopy examination revealed chromatin condensation, fragmented nuclei, and membrane blebbing and apoptotic bodies in pathogen invaded cells.

Corotchi M.C.,Nicolae Simionescu Institute of Cellular Biology and Pathology of the Romanian Academy | Popa M.A.,Nicolae Simionescu Institute of Cellular Biology and Pathology of the Romanian Academy | Simionescu M.,Nicolae Simionescu Institute of Cellular Biology and Pathology of the Romanian Academy
Romanian Journal of Morphology and Embryology | Year: 2016

Human adult stem and progenitor cells are promising cell types widely studied for their clinical benefits. A reduced number of stem cells present in the human body are associated with numerous dysfunctions. Since androgens have a profound effect on different cell types, we questioned whether testosterone (T), one of the main androgens, influence and are involved in the proliferation of stem cells and/or affect their stemness potential. Isolated mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) were cultured and then stimulated with different concentration of testosterone (10–100 nM). The cellular proliferation rate, adhesion, and viability were measured in real-time using xCELLigence system and DNA-cell proliferation assay. The immunophenotype of the stimulated cells versus non-stimulated cells was determined by flow cytometry. The maximal effect on MSCs and EPCs proliferation was obtained at 40 nM testosterone; this concentration was used in further experiments. The cellular index measured in real-time by impedance-based dynamic measurements revealed that 40 nM testosterone had a proliferative effect on both MSCs and EPCs, having a proliferative index of ~50% above the control (non-stimulated) cells. Furthermore, flow cytometry assay indicated that testosterone stimulation did not alter the phenotype of MSCs and EPCs, both cell types preserving the expression of the characteristic surface markers. Testosterone stimulation increases the proliferation and preserves stemness of MSCs and EPCs suggesting that, besides other factors, the hormone may engineer these cells and increase their therapeutic potential. © 2016 Editura Academiei Romane. All rights reserved.

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