Mesenchymal Stem-Cell Remodeling of Adsorbed Type-I Collagen—The Effect of Collagen Oxidation

This study describes the effect of collagen type I (Col I) oxidation on its physiological remodeling by adipose tissue-derived mesenchymal stem cells (ADMSCs), both mechanical and proteolytic, as an in vitro model for the acute oxidative stress that may occur in vivo upon distinct environmental changes. Morphologically, remodeling was interpreted as the mechanical rearrangement of adsorbed FITC-labelled Col I into a fibril-like pattern. This process was strongly abrogated in cells cultured on oxidized Col I albeit without visible changes in cell morphology. Proteolytic activity was quantified utilizing fluorescence de-quenching (FRET effect). The presence of ADMSCs caused a significant increase in native FITC-Col I fluorescence, which was almost absent in the oxidized samples. Parallel studies in a cell-free system confirmed the enzymatic de-quenching of native FITC-Col I by Clostridial collagenase with statistically significant inhibition occurring in the oxidized samples. Structural changes to the oxidized Col I were further studied by differential scanning calorimetry. In the oxidized samples, an additional endotherm with sustained enthalpy (∆H) was observed at 33.6 °C along with Col I’s typical one at 40.5 °C. Collectively, these data support that the remodeling of Col I by ADMSCs is altered upon oxidation due to intrinsic changes to the protein’s structure, which represents a novel mechanism for the control of stem cell behavior

Molecular pathogenesis of spontaneous abortions - Whole genome copy number analysis and expression of angiogenic factors.

OBJECTIVE To study two major molecular alterations in spontaneous abortions (SA) with unexplained etiology - fetal genomic anomalies and the endometrial expression of main angiogenic factors VEGFA/VEGFR2 and chemokines SDF-1/CXCR4. MATERIALS AND METHODS Whole genome copy number analysis by arrayCGH or Next Generation Sequencing (NGS) was applied for detection of fetal genomic imbalances. The abortive decidua of SA without fetal aneuploidies was further investigated for expression levels of the abovementioned factors using real time PCR analysis. A total of 30 abortive materials were collected from spontaneous abortions after exclusion of known predisposing factors. RESULTS In 21 of 30 spontaneous abortions (70%), genomic anomalies were discovered by whole genome copy number analysis. Numerical anomalies were detected in 90% of aberrant cases, and in 10% - structural aberrations were revealed. An increased expression for essential factors of angiogenesis was identified in spontaneous abortions' tissues - 3.44 times for VEGFA and 10.29 times for VEGFR2. We found an average of 14 times increase in the expression levels of SDF-1 and 3.21 times for its receptor CXCR4. CONCLUSION We could suggest the occurrence of increased angiogenesis in SA without fetal aneuploidies, compared to the control tissues, which could lead to increased oxidative stress and fetal loss

Conditioned Medium from Adipose Tissue-Derived Mesenchymal Stem Cells Induces CD4+FOXP3+ Cells and Increases IL-10 Secretion

Mesenchymal stem cells (MSCs) are a new and promising tool for therapy of autoimmune disorders. In recent years their possibility to take part in the modulation of the immune response is discussed. The exact mechanisms for immunoregulation realized by MSCs are not clear yet, but interactions with other immunoregulatory cells may be involved in this process. The investigation of the influence of MSCs on the expression of FoxP3 and cytokine secretion by T helper cells was the aim of this study. T helper cells were isolated from PBMCs by magnetic separation and MSCs were isolated from human adipose tissue, and CD4+ T cells were cultured with conditional medium of MSCs. The methods which were used include flow cytometry, ELISA, and Human Proteome profiler kits. The results demonstrated that secretory factors in MSCs conditional medium lead to increased expression of FoxP3 and increased secretion of IL-10 by T helpers. The obtained results give us opportunity to discuss the interaction between two kinds of immunoregulatory cells: MSCs and FoxP3+ T helpers. We suppose that this interaction leads to increased number of immunosuppressive helpers which secrete IL-10. MSCs provide some of their immunosuppressive functions acting on T regulatory cells, and we believe that IL-6 secreted by MSCs is involved in this process

Correlation between Cytogenetic Findings and Spermatogenic Failure in Bulgarian Infertile Men

The aim of our study was to determine the type and frequency of chromosomal aberrations and polymorphisms in men with different degrees of spermatogenic failure in comparison to men with normozoospermia, in order to find correlations between cytogenetic findings and the abnormal results of semen analysis. In our study, we performed cytogenetic analysis in 901 infertile men, divided into five groups according to semen analysis—normozoospermia (86), asthenozoospermia (394), oligoasthenozoospermia (182), severe male factor (100), and azoospermia (139). The frequency of polymorphisms was similar in all groups (11–16%, without significant differences). The frequency of numerical and structural aberrations increases with the degree of the spermatogenic failure (3.5% in normozoospermia, 5.6% in asthenozoospermia, 9.8% in oligoasthenozoospermia, 9% in severe male factor, and 13.5% in azoospermia). We found a significantly higher incidence of numerical chromosomal aberrations in severe male factor (7%) and azoospermia (9.3%). Oligoasthenozoospermia occured in 45% of cases with translocation, compared to 20% in the group with a normal karyotype. We revealed that chromosomal translocations are tightly associated with oligoasthenozoospermia, whereas numerical chromosomal aberrations—with severe male factor and azoospermia. The impact of chromosome polymorphisms on male infertility should be studied in greater detail

Osteogenic differentiation of mesenchymal stem cells using hybrid nanofibers with different configurations and dimensionality

[EN] Novel, hybrid fibrinogen/polylactic acid (FBG/PLA) nanofibers with different configuration (random vs aligned) and dimensionality (2¿D vs 3¿D environment) were used to control the overall behavior and the osteogenic differentiation of human adipose¿derived mesenchymal stem cells (ADMSCs). Aligned nanofibers in both the 2¿D and 3¿D configurations are proved to be favored for osteodifferentiation. Morphologically, we found that on randomly configured nanofibers, the cells developed a stellate¿like morphology with multiple projections; however, time¿lapse analysis showed significantly diminished cell movements. Conversely, an elongated cell shape with advanced cell spreading and extended actin cytoskeleton accompanied with significantly increased cell mobility were observed when cells attached on aligned nanofibers. Moreover, a clear tendency for higher alkaline phosphatase activity was also found on aligned fibers when ADMSCs were switched to osteogenic induction medium. The strongest accumulation of Alizarin red (AR) and von Kossa stain at 21 days of culture in osteogenic medium were found on 3¿D aligned constructs while the rest showed lower and rather undistinguishable activity. Quantitative reverse transcription¿polymerase chain reaction analysis for Osteopontin (OSP) and RUNX 2 generally confirmed this trend showing favorable expression of osteogenic genes activity in 3¿D environment particularly in aligned configuration.Contract grant sponsor: CIBER-BBN Spain (project BIOSURFACES) Contract grant sponsor: European Commission through the FP7 Industry-Academia Partnerships and Pathways (IAPP) project FIBROGELNET; contract grant number: PAP-GA-2012-324386 Contract grant sponsor: Spanish Ministry of Economy and Competitiveness; contract grant number: MAT 2015-69315-C3 MYOHEAL Contract grant sponsor: The Scientific and Technological Research Council of Turkey (TUBITAK); contract grant number: 11S497Gugutkov, D.; Awaja, F.; Belemezova, K.; Keremidarska, M.; Krasteva, N.; Kyurkchiev, S.; Gallego-Ferrer, G.... (2017). Osteogenic differentiation of mesenchymal stem cells using hybrid nanofibers with different configurations and dimensionality. Journal of Biomedical Materials Research Part A. 105(7):2065-2074. https://doi.org/10.1002/jbm.a.36065S20652074105