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Abstract: The hematopoietic stem cell (HSC) niche undergoes detrimental changes with age. The molecular differences between young and old niches are well studied and understood; however, young and old niches have not yet been extensively characterized in terms of morphology. In the present work, a 2D stromal model of young and old HSC niches isolated from bone marrow was investigated using light and scanning electron microscopy (SEM) to characterize cell density after one, two, or three weeks of culturing, cell shape, and cell surface morphological features. Our work is aimed at identifying morphological differences between young and old niche cells that could be used to discriminate between their respective murine HSC niches. The results show several age- specific morphological characteristics. The old niches differ from the young ones in terms of lower cell proliferating capacity, increased cell size with a flattened appearance, increased number of adipocytes, and the presence of tunneling nanotubes. In addition, proliferating cell clusters are present in the young niches but not in the old niches. Together, these characteristics could be used as a relatively simple and reliable tool to discriminate between young and old murine HSC niches and as a complementary approach to imaging with specific cellular markers.
Keywords: bone marrow, hematoopetic stem cell niche, aging, adipocytes, scanning electron microscopy
Published in DiRROS: 26.01.2024; Views: 214; Downloads: 107
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Abstract: Introduction: Cellular nanovesicles (CNVs), that are shed from cells, have been recognized as promising indicators of health status. We analyzed the effect of long-distance running on concentration of CNVs, along with some standard blood parameters, in 27 athletes two days before and > 15 hours after physical effort. Methods: CNVs were isolated by repetitive centrifugation and washing of samples, and assessed by flow cytometry. Cholinesterase (ChE) and glutathione S-transferase (GST) activity were measured spectrophotometrically. Interleukin 6 (IL-6) and tumor necrosis factor-% (TNF-%) concentrations were measured using enzyme-linked immunosorbent assay (ELISA). C-reactive protein (CRP) was measured with immunoturbidimetric determination and lipidogram parameters were measured by enzymatic colorimetric assay. Flow cytometry was used for blood cell count and mean platelet volume (MPV) measurement. Results: More than 15 hours after physical effort a decrease was found in CNVs% concentration in isolates from blood (46%; p< 0.05), in ChE activity in whole blood (47%; p< 0.001), in plasma (34%; p< 0.01), and in erythrocyte suspension (54%; p< 0.001), as well as in GST activity in erythrocyte suspension (16%; p< 0.01) and in IL-6 concentration in plasma (63%; p< 0.05). We found no change in GST activity in plasma and in TNF-% concentration in plasma. Correlations (> 0.8; p< 0.001) between CNVs% concentration and ChE activity, and GST activity, respectively, in erythrocyte suspension were found. Conclusion: We found that > 15 hours post-physical effort, CNVs% concentration was below the initial value, concomitant with other measured parameters: ChE and GST activity as well as IL-6 concentration, indicating a favorable effect of physical effort on health status. CNVs% concentration and ChE activity in isolates from peripheral blood proved to have potential as indicators of the response of the human body to inflammation after physical effort. Physical activity should be considered as an important factor in preparation of subjects for blood sampling in procedures focusing on CNV-containing diagnostic and therapeutic compounds.
Keywords: membrane vesiculation, physical effort, blood samples, inflammation process, cellular nanovesicles, marathon
Published in DiRROS: 25.01.2021; Views: 1302; Downloads: 1612
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