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Rare earth elements (REEs) are currently used in fertilizers, but their behavior in the soil-plant system remains poorly studied. The assessment of the binding of REEs to various organomineral phases of soils remains an important task. Using soddy-podzolic soil and typical chernozem as examples, we performed a comparative study of the dynamic fractionation of REEs in a rotating coiled column (RCC) and a microcolumn (MC). We isolated the exchangeable fraction, specifically adsorbed fraction, and fractions bound to manganese oxides, bound to organic matter, and bound to amorphous and weakly crystallized iron and aluminum oxides using, 0.05 M Ca(NO.sub.3).sub.2, 0.43 M CH.sub.3COOH, and a 0.1 M NH.sub.2OH·HCl solution (pH 3.6), a 0.1 M K.sub.4P.sub.2O.sub.7 solution (pH 11.0), and a 0.1 M (NH.sub.4).sub.2C.sub.2O.sub.4 solution (pH 3.2), respectively. Concentrations of elements in the initial samples and eluate fractions were determined by atomic emission spectrometry and inductively coupled plasma mass spectrometry. The results suggest that the main extractable REE form (up to 40% of the total content) is provided by organometallic complexes extracted with a 0.1 M K.sub.4P.sub.2O.sub.7 solution. For chernozem (soils with a high content of organic matter), fractionation in the RCC and MC yielded comparable results. For soddy-podzolic soil, some differences were observed in the isolation of the first three fractions: exchangeable, specifically adsorbed, and bound to manganese oxides. Both RCC and MC can be successfully used for the dynamic fractionation of REE in soils; however, it is preferable to use an MC in analyzing many samples as a simpler and more affordable device., Author(s): Yu. N. Shatrova [sup.1] , R. Kh. Dzhenloda [sup.1] , N. N. Fedyunina [sup.1] [sup.2] , V. K. Karandashev [sup.1] [sup.3] , P. S. Fedotov [sup.1] Author Affiliations: (1) [...]

Background/Objectives: Dermal fibroblasts (DFs) are key participants in skin hypertrophic scarring, and their properties are being studied to identify the molecular and cellular mechanisms underlying the pathogenesis of skin scarring. Methods: In the present work, we performed a comparative analysis of DFs isolated from normal skin (normal dermal fibroblasts, NDFs), and hypertrophic scar skin (hypertrophic scar fibroblasts, HTSFs). The fibroblasts were karyotyped and phenotyped, and experiments on growth rate, wound healing, and single-cell motility were conducted. Results: Comparative analysis revealed a minor karyotype difference between cells. However, HTSFs are characterized by higher proliferation level and motility compared to NDFs. These significant differences may be associated with quantitative and qualitative differences in the cell secretome. A proteomic comparison of NDF and HTSF found that differences were associated with metabolic proteins reflecting physiological differences between the two cells lines. Numerous unique proteins were found only in the vesicular phase of vHTSFs. Some proteins involved in cell proliferation (protein-glutamine gamma-glutamyltransferase K) and cell motility (catenin delta-1), which regulate gene transcription and the activity of Rho family GTPases and downstream cytoskeletal dynamics, were identified. A number of proteins which potentially play a role in fibrosis and inflammation (mucin-5B, CD97, adhesion G protein-coupled receptor E2, antileukoproteinase, protein S100-A8 and S100-A9, protein caspase recruitment domain-containing protein 14) were detected in vHTSFs. Conclusions: A comparative analysis of primary cell cultures revealed their various properties, especially in the cell secretome. These proteins may be considered promising target molecules for developing treatment or prevention strategies for pathological skin scarring. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are currently used in fertilizers, but their behavior in the soil-plant system remains poorly understood. The assessment of the binding of REEs to various organomineral phases of soils remains an important task. Using soddy-podzolic soil and typical chernozem as examples, we performed a comparative study of two procedures of the fractionation of REEs in soils in the dynamic extraction mode. According to a five-stage procedure using a 0.05 M Ca(NO.sub.3).sub.2 solution, 0.43 M CH.sub.3COOH, a 0.1 M NH.sub.2OH·HCl solution (pH 3.6), a 0.1 M K.sub.4P.sub.2O.sub.7 solution (pH 11.0), and a 0.1 M (NH.sub.4).sub.2C.sub.2O.sub.4 solution (pH 3.2), five extractable fractions were isolated, which can be conventionally named, exchangeable, specifically sorbed, associated with manganese oxides, associated with organic matter, and associated with amorphous and weakly crystallized oxides of iron and aluminum, respectively. A four-stage procedure, using a 0.05 M Ca(NO.sub.3).sub.2 solution, a 0.1 M citric acid solution, a 0.05 M NH.sub.2OH·HCl solution (pH 2.0), and 1.4 M HNO.sub.3, enabled the isolation of exchange ions and fractions bound to carbonates, reducible, and acid-soluble, respectively. The concentration of elements in the initial samples and extracts was determined by atomic emission spectrometry and inductively coupled plasma mass spectrometry. In a five-stage procedure, the main extractable REE species (up to 40% of the total content) is provided by organometallic complexes extracted with a 0.1 M solution of potassium pyrophosphate. Using a four-stage procedure, the main fraction of REEs (up to 30%) is extracted with 1.4 M nitric acid. Using La, Ce, and Nd as examples, two procedures were compared. The concentration of REEs extracted by nitric acid (four-stage procedure) corresponds to the concentration of REEs extracted by pyrophosphate (five-stage procedure). In addition, the use of a 0.05 M NH.sub.2OH·HCl solution at pH 2.0 (four-stage procedure) and a 0.1 M (NH.sub.4).sub.2C.sub.2O.sub.4 solution at pH 3.2 (five-stage procedure) leads to similar results. Thus, both procedures can be used for the dynamic fractionation of REE species in soils. However, the five-stage procedure is preferable, because the reagents used are sufficiently selective with respect to the dissolved organomineral phases of soils, which more clearly reflects the pattern of the distribution of REE species., Author(s): Yu. N. Shatrova [sup.1], R. Kh. Dzhenloda [sup.1], N. N. Fedyunina [sup.2], V. K. Karandashev [sup.2] [sup.3], P. S. Fedotov [sup.1] Author Affiliations: (1) grid.439081.7, 0000 0004 0380 8849, [...]

Ionic homeostasis of human mesenchymal stem cells (MSCs) during their long-term cultivation was studied. It was found that, at early passages (second to fourth), the intracellular K+ content calculated for total cellular protein was almost 40% higher than in cells of the same clone after 12–15 passages. Under the same conditions, the intracellular Na+ content remains practically unchanged in MSCs with age. Flow cytometry assay of MSC proliferation at various passages revealed that a decrease in the intracellular K+ content correlated with the cell accumulation in the G1 phase of the cell cycle and was accompanied by a slower cell division. On the basis of data on monovalent ion transport in permanent cell lines of different origin, human stem cells as well as activated human lymphocytes, the mechanism of implication of K+ in the cell proliferation has been discussed. It is suggested that changes in cellular K+ content per total cell protein accompanying triggering or inhibition of cell proliferation show the involvement of K+ in the cell volume regulation. The high intracellular K+ content is important for successful proliferation of hMSCs, and the cell K+ content per cell protein is an informative test for assessing the functional status of stem cells in vitro. [ABSTRACT FROM AUTHOR]

In this study, we reported proliferation-related changes in cell K+ and Na+ content and K+ influxes in cultivated human mesenchymal stem cells (MSCs). The intracellular K+ content calculated per cell protein amount was found to decrease in the growing culture, whereas intracellular Na+ content was not significantly changed. It was also revealed that, at higher densities of an hMSC monolayer, the ouabain-sensitive K+ influx was decreased thus indicating a decline in Na+, K+ pump-mediated transport. We analyzed the cell cycle profiles of hMSC cultures and found that, under optimal culture conditions in high-density cultures, the decline in K+ content per cell protein was correlated with accumulation of G1 cells and slowing down cell proliferation in the population. It is concluded that cell K+ content per cell protein is an informative test for assessing the functional status of stem cells in vitro. [ABSTRACT FROM AUTHOR]