88 research outputs found
How to track cellular aging of mesenchymal stromal cells?
Mesenchymal stromal cells (MSC) are currently tested in a large number of
clinical trials and raise high hope in regenerative medicine. These cells
have to be expanded in vitro before transplantation and several studies
demonstrated that long-term culture evokes continuous changes in MSC:
proliferation rate decays, the cell size increases, differentiation
potential is affected, chromosomal instabilities may arise and molecular
changes are acquired. Long-term culture of cell preparations might also
have therapeutic consequences, although this has hardly been addressed in
ongoing trials so far. Reliable therapeutic regimens necessitate quality
control of cellular products. This research perspective summarizes
available methods to track cellular aging of MSC. We have demonstrated that
gene expression changes and epigenetic modifications are
continuously acquired during replicative senescence. Molecular analysis of
a suitable panel of genes might provide a robust tool to assess efficiency
and safety of long-term expansion
Littoral undersea warfare: a case study in process modelling for functionality and introperability of complex systems
The goal of this investigation is to demonstrate the application of a
process modelling approach to architect a System of Systems (SoS) capable of
conducting Anti-Submarine Warfare (ASW) operations projecting to the year
2025. Process modelling is a methodology for architectural analysis for
complex systems whose operation is characterised by âprocessesâ whose
sequential execution may be scaled-up to understand overall system behaviour.
It is ideally suited to address complexity and interoperability issues of an ASW
SoS. New contributions of this work include the successful implementation of a
process modelling approach to architect an ASW SoS and a cohesive set of
results analysing its operation with future projections to the year 2025.
We believe this work may serve as a foundation for future systems engineering
research addressing interoperability and performance of complex systems
whose function is closely tied to time-dependent processes, with particular
application to military and security systems
Human Dermis Harbors Distinct Mesenchymal Stromal Cell Subsets
Multipotent mesenchymal stromal cells (MSCs) are found in a variety of adult tissues including human dermis. These MSCs are morphologically similar to bone marrowâderived MSCs, but are of unclear phenotype. To shed light on the characteristics of human dermal MSCs, this study was designed to identify and isolate dermal MSCs by a specific marker expression profile, and subsequently rate their mesenchymal differentiation potential. Immunohistochemical staining showed that MSC markers CD73/CD90/CD105, as well as CD271 and SSEA-4, are expressed on dermal cells in situ. Flow cytometric analysis revealed a phenotype similar to bone marrowâderived MSCs. Human dermal cells isolated by plastic adherence had a lower differentiation capacity as compared with bone marrowâderived MSCs. To distinguish dermal MSCs from differentiated fibroblasts, we immunoselected CD271+ and SSEA-4+ cells from adherent dermal cells and investigated their mesenchymal differentiation capacity. This revealed that cells with increased adipogenic, osteogenic, and chondrogenic potential were enriched in the dermal CD271+ population. The differentiation potential of dermal SSEA-4+ cells, in contrast, appeared to be limited to adipogenesis. These results indicate that specific cell populations with variable mesenchymal differentiation potential can be isolated from human dermis. Moreover, we identified three different subsets of dermal mesenchymal progenitor cells
Multi-Parameter Analysis of Biobanked Human Bone Marrow Stromal Cells Shows Little Influence for Donor Age and Mild Comorbidities on Phenotypic and Functional Properties
Heterogeneous populations of human bone marrow-derived stromal cells (BMSC) are among the most frequently tested cellular therapeutics for treating degenerative and immune disorders, which occur predominantly in the aging population. Currently, it is unclear whether advanced donor age and commonly associated comorbidities affect the properties of ex vivo-expanded BMSCs. Thus, we stratified cells from adult and elderly donors from our biobank (n = 10 and n = 13, mean age 38 and 72 years, respectively) and compared their phenotypic and functional performance, using multiple assays typically employed as minimal criteria for defining multipotent mesenchymal stromal cells (MSCs). We found that BMSCs from both cohorts meet the standard criteria for MSC, exhibiting similar morphology, growth kinetics, gene expression profiles, and pro-angiogenic and immunosuppressive potential and the capacity to differentiate toward adipogenic, chondrogenic, and osteogenic lineages. We found no substantial differences between cells from the adult and elderly cohorts. As positive controls, we studied the impact of in vitro aging and inflammatory cytokine stimulation. Both conditions clearly affected the cellular properties, independent of donor age. We conclude that in vitro aging rather than in vivo donor aging influences BMSC characteristics
A cancer stem cell-like phenotype is associated with miR-10b expression in aggressive squamous cell carcinomas
Background
Cutaneous squamous cell carcinomas (cSCC) are the primary cause of premature deaths in patients suffering from the rare skin-fragility disorder recessive dystrophic epidermolysis bullosa (RDEB), which is in marked contrast to the rarely metastasizing nature of these carcinomas in the general population. This remarkable difference is attributed to the frequent development of chronic wounds caused by impaired skin integrity. However, the specific molecular and cellular changes to malignancy, and whether there are common players in different types of aggressive cSCCs, remain relatively undefined.
Methods
MiRNA expression profiling was performed across various cell types isolated from skin and cSCCs. Microarray results were confirmed by qPCR and by an optimized in situ hybridization protocol. Functional impact of overexpression or knock-out of a dysregulated miRNA was assessed in migration and 3D-spheroid assays. Sample-matched transcriptome data was generated to support the identification of disease relevant miRNA targets.
Results
Several miRNAs were identified as dysregulated in cSCCs compared to control skin. These included the metastasis-linked miR-10b, which was significantly upregulated in primary cell cultures and in archival biopsies. At the functional level, overexpression of miR-10b conferred the stem cell-characteristic of 3D-spheroid formation capacity to keratinocytes. Analysis of miR-10b downstream effects identified a novel putative target of miR-10b, the actin- and tubulin cytoskeleton-associated protein DIAPH2.
Conclusion
The discovery that miR-10b mediates an aspect of cancer stemness â that of enhanced tumor cell adhesion, known to facilitate metastatic colonization â provides an important avenue for future development of novel therapies targeting this metastasis-linked miRNA
Recommended from our members
The GPR 55 agonist, L-α-lysophosphatidylinositol, mediates ovarian carcinoma cell-induced angiogenesis
Background and Purpose Highly vascularized ovarian carcinoma secretes the putative endocannabinoid and GPR55 agonist, L-α-lysophosphatidylinositol (LPI), into the circulation. We aimed to assess the involvement of this agonist and its receptor in ovarian cancer angiogenesis. Experimental Approach Secretion of LPI by three ovarian cancer cell lines (OVCAR-3, OVCAR-5 and COV-362) was tested by mass spectrometry. Involvement of cancer cell-derived LPI on angiogenesis was tested in the in vivo chicken chorioallantoic membrane (CAM) assay along with the assessment of the effect of LPI on proliferation, network formation, and migration of neonatal and adult human endothelial colony-forming cells (ECFCs). Engagement of GPR55 was verified by using its pharmacological inhibitor CID16020046 and diminution of GPR55 expression by four different target-specific siRNAs. To study underlying signal transduction, Western blot analysis was performed. Key Results Ovarian carcinoma cell-derived LPI stimulated angiogenesis in the CAM assay. Applied LPI stimulated proliferation, network formation, and migration of neonatal ECFCs in vitro and angiogenesis in the in vivo CAM. The pharmacological GPR55 inhibitor CID16020046 inhibited LPI-stimulated ECFC proliferation, network formation and migration in vitro as well as ovarian carcinoma cell- and LPI-induced angiogenesis in vivo. Four target-specific siRNAs against GPR55 prevented these effects of LPI on angiogenesis. These pro-angiogenic effects of LPI were transduced by GPR55-dependent phosphorylation of ERK1/2 and p38 kinase. Conclusions and Implications We conclude that inhibiting the pro-angiogenic LPI/GPR55 pathway appears a promising target against angiogenesis in ovarian carcinoma
Less is more: Antibiotics at the beginning of life.
Antibiotic exposure at the beginning of life can lead to increased antimicrobial resistance and perturbations of the developing microbiome. Early-life microbiome disruption increases the risks of developing chronic diseases later in life. Fear of missing evolving neonatal sepsis is the key driver for antibiotic overtreatment early in life. Bias (a systemic deviation towards overtreatment) and noise (a random scatter) affect the decision-making process. In this perspective, we advocate for a factual approach quantifying the burden of treatment in relation to the burden of disease balancing antimicrobial stewardship and effective sepsis management
Analysis of Antibiotic Exposure and Early-Onset Neonatal Sepsis in Europe, North America, and Australia.
IMPORTANCE
Appropriate use of antibiotics is life-saving in neonatal early-onset sepsis (EOS), but overuse of antibiotics is associated with antimicrobial resistance and long-term adverse outcomes. Large international studies quantifying early-life antibiotic exposure along with EOS incidence are needed to provide a basis for future interventions aimed at safely reducing neonatal antibiotic exposure.
OBJECTIVE
To compare early postnatal exposure to antibiotics, incidence of EOS, and mortality among different networks in high-income countries.
DESIGN, SETTING, AND PARTICIPANTS
This is a retrospective, cross-sectional study of late-preterm and full-term neonates born between January 1, 2014, and December 31, 2018, in 13 hospital-based or population-based networks from 11 countries in Europe and North America and Australia. The study included all infants born alive at a gestational age greater than or equal to 34 weeks in the participating networks. Data were analyzed from October 2021 to March 2022.
EXPOSURES
Exposure to antibiotics started in the first postnatal week.
MAIN OUTCOMES AND MEASURES
The main outcomes were the proportion of late-preterm and full-term neonates receiving intravenous antibiotics, the duration of antibiotic treatment, the incidence of culture-proven EOS, and all-cause and EOS-associated mortality.
RESULTS
A total of 757âŻ979 late-preterm and full-term neonates were born in the participating networks during the study period; 21âŻ703 neonates (2.86%; 95% CI, 2.83%-2.90%), including 12âŻ886 boys (59.4%) with a median (IQR) gestational age of 39 (36-40) weeks and median (IQR) birth weight of 3250 (2750-3750) g, received intravenous antibiotics during the first postnatal week. The proportion of neonates started on antibiotics ranged from 1.18% to 12.45% among networks. The median (IQR) duration of treatment was 9 (7-14) days for neonates with EOS and 4 (3-6) days for those without EOS. This led to an antibiotic exposure of 135 days per 1000 live births (range across networks, 54-491 days per 1000 live births). The incidence of EOS was 0.49 cases per 1000 live births (range, 0.18-1.45 cases per 1000 live births). EOS-associated mortality was 3.20% (12 of 375 neonates; range, 0.00%-12.00%). For each case of EOS, 58 neonates were started on antibiotics and 273 antibiotic days were administered.
CONCLUSIONS AND RELEVANCE
The findings of this study suggest that antibiotic exposure during the first postnatal week is disproportionate compared with the burden of EOS and that there are wide (up to 9-fold) variations internationally. This study defined a set of indicators reporting on both dimensions to facilitate benchmarking and future interventions aimed at safely reducing antibiotic exposure in early life
- âŠ