scholarly journals Aldehyde Dehydrogenases: Not Just Markers, but Functional Regulators of Stem Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Giuseppe Vassalli
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Cellular Function ◽  
Stem Cell Marker ◽  
Cell Populations ◽  
Aldh Activity ◽  
Cellular Functions ◽  
Stem And Progenitor Cells

Aldehyde dehydrogenase (ALDH) is a superfamily of enzymes that detoxify a variety of endogenous and exogenous aldehydes and are required for the biosynthesis of retinoic acid (RA) and other molecular regulators of cellular function. Over the past decade, high ALDH activity has been increasingly used as a selectable marker for normal cell populations enriched in stem and progenitor cells, as well as for cell populations from cancer tissues enriched in tumor-initiating stem-like cells. Mounting evidence suggests that ALDH not only may be used as a marker for stem cells but also may well regulate cellular functions related to self-renewal, expansion, differentiation, and resistance to drugs and radiation. ALDH exerts its functional actions partly through RA biosynthesis, as all-trans RA reverses the functional effects of pharmacological inhibition or genetic suppression of ALDH activity in many cell types in vitro. There is substantial evidence to suggest that the role of ALDH as a stem cell marker comes down to the specific isoform(s) expressed in a particular tissue. Much emphasis has been placed on the ALDH1A1 and ALDH1A3 members of the ALDH1 family of cytosolic enzymes required for RA biosynthesis. ALDH1A1 and ALDH1A3 regulate cellular function in both normal stem cells and tumor-initiating stem-like cells, promoting tumor growth and resistance to drugs and radiation. An improved understanding of the molecular mechanisms by which ALDH regulates cellular function will likely open new avenues in many fields, especially in tissue regeneration and oncology.

scholarly journals qPCR analysis of mesenchymal stem cell marker expression during the long-term culture of canine adipocyte derived stem cells

2020 ◽  
Vol 8 (4) ◽  
pp. 139-145
Author(s):  
Rut Bryl ◽  
Claudia Dompe ◽  
Maurycy Jankowski ◽  
Katarzyna Stefańska ◽  
Afsaneh Golkar Narenji ◽  
...  
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
Stem Cell Marker ◽  
Pcr Analysis ◽  
Marker Genes ◽  
Long Term Culture ◽  
Marker Expression

AbstractDue to its availability and accessibility, adipose tissue has been the subject of various studies in many different medical fields and is believed to be a useful source of stem cells. The ability of ASCs to differentiate towards different cell lineages, with possibility of directing this differentiation, increases their possible clinical applications, and they have been widely employed in multiple therapies and treatment of different pathologies. However, a deeper understanding of the molecular mechanisms underlying the ASCs osteoblastic and chondrocyte differentiation may lead to novel applications treating a multitude of different bone-related diseases through techniques more likely meeting worldwide consensus. In this study, the RT-qPCR method was used to determine the changes in expression of ASC specific markers (CD105, CD73, CD14, CD34, CD90 and CD45) before and after long-term (14-day) in vitro cultures. To confirm the identity of the investigated cells, flow cytometry was used to evaluate the presence of positive (CD44, CD90) and negative (CD45, CD34) ASC markers. Overall, the results of the PCR analysis showed a significant change in expression of most of the marker genes, indicating significant changes in the cultured cells caused by their long-term culture, potentially altering their original stem-like characteristics.Running title: ASC marker expression during long-term in vitro culture

scholarly journals The hemogenic endothelium: a critical source for the generation of PSC-derived hematopoietic stem and progenitor cells

2021 ◽  
Author(s):  
Lucas Lange ◽  
Michael Morgan ◽  
Axel Schambach
Keyword(s):  
Stem Cells ◽  
De Novo ◽  
Cell Types ◽  
Hemogenic Endothelium ◽  
Hematopoietic Stem ◽  
Autologous Cell ◽  
Stem And Progenitor Cells ◽  
Bona Fide

AbstractIn vitro generation of hematopoietic cells and especially hematopoietic stem cells (HSCs) from human pluripotent stem cells (PSCs) are subject to intensive research in recent decades, as these cells hold great potential for regenerative medicine and autologous cell replacement therapies. Despite many attempts, in vitro, de novo generation of bona fide HSCs remains challenging, and we are still far away from their clinical use, due to insufficient functionality and quantity of the produced HSCs. The challenges of generating PSC-derived HSCs are already apparent in early stages of hemato-endothelial specification with the limitation of recapitulating complex, dynamic processes of embryonic hematopoietic ontogeny in vitro. Further, these current shortcomings imply the incompleteness of our understanding of human ontogenetic processes from embryonic mesoderm over an intermediate, specialized hemogenic endothelium (HE) to their immediate progeny, the HSCs. In this review, we examine the recent investigations of hemato-endothelial ontogeny and recently reported progress for the conversion of PSCs and other promising somatic cell types towards HSCs with the focus on the crucial and inevitable role of the HE to achieve the long-standing goal—to generate therapeutically applicable PSC-derived HSCs in vitro.

scholarly journals Human pluripotent stem cells for the modelling and treatment of respiratory diseases

2021 ◽  
Vol 30 (161) ◽  
pp. 210042
Author(s):  
Pien A. Goldsteen ◽  
Christina Yoseif ◽  
Amalia M. Dolga ◽  
Reinoud Gosens
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
High Throughput Screening ◽  
Respiratory Diseases ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Human Pluripotent Stem Cells ◽  
Medical Need ◽  
New Chemical Entities

Respiratory diseases are among the leading causes of morbidity and mortality worldwide, representing a major unmet medical need. New chemical entities rarely make it into the clinic to treat respiratory diseases, which is partially due to a lack of adequate predictive disease models and the limited availability of human lung tissues to model respiratory disease. Human pluripotent stem cells (hPSCs) may help fill this gap by serving as a scalable human in vitro model. In addition, human in vitro models of rare genetic mutations can be generated using hPSCs. hPSC-derived epithelial cells and organoids have already shown great potential for the understanding of disease mechanisms, for finding new potential targets by using high-throughput screening platforms, and for personalised treatments. These potentials can also be applied to other hPSC-derived lung cell types in the future. In this review, we will discuss how hPSCs have brought, and may continue to bring, major changes to the field of respiratory diseases by understanding the molecular mechanisms of the pathology and by finding efficient therapeutics.

scholarly journals Pituitary Remodeling Throughout Life: Are Resident Stem Cells Involved?

2021 ◽  
Vol 11 ◽  
Author(s):  
Emma Laporte ◽  
Annelies Vennekens ◽  
Hugo Vankelecom
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pituitary Gland ◽  
Molecular Mechanisms ◽  
Pituitary Function ◽  
Cell Phenotype ◽  
Cell Populations ◽  
Cell Remodeling

The pituitary gland has the primordial ability to dynamically adapt its cell composition to changing hormonal needs of the organism throughout life. During the first weeks after birth, an impressive growth and maturation phase is occurring in the gland during which the distinct hormonal cell populations expand. During pubertal growth and development, growth hormone (GH) levels need to peak which requires an adaptive enterprise in the GH-producing somatotrope population. At aging, pituitary function wanes which is associated with organismal decay including the somatopause in which GH levels drop. In addition to these key time points of life, the pituitary’s endocrine cell landscape plastically adapts during specific (patho-)physiological conditions such as lactation (need for PRL) and stress (engagement of ACTH). Particular resilience is witnessed after physical injury in the (murine) gland, culminating in regeneration of destroyed cell populations. In many other tissues, adaptive and regenerative processes involve the local stem cells. Over the last 15 years, evidence has accumulated that the pituitary gland houses a resident stem cell compartment. Recent studies propose their involvement in at least some of the cell remodeling processes that occur in the postnatal pituitary but support is still fragmentary and not unequivocal. Many questions remain unsolved such as whether the stem cells are key players in the vivid neonatal growth phase and whether the decline in pituitary function at old age is associated with decreased stem cell fitness. Furthermore, the underlying molecular mechanisms of pituitary plasticity, in particular the stem cell-linked ones, are still largely unknown. Pituitary research heavily relies on transgenic in vivo mouse models. While having proven their value, answers to pituitary stem cell-focused questions may more diligently come from a novel powerful in vitro research model, termed organoids, which grow from pituitary stem cells and recapitulate stem cell phenotype and activation status. In this review, we describe pituitary plasticity conditions and summarize what is known on the involvement and phenotype of pituitary stem cells during these pituitary remodeling events.

Neural Development by Transplanted Human Embryonal Carcinoma Stem Cells Expressing Green Fluorescent Protein

2005 ◽  
Vol 14 (6) ◽  
pp. 339-351 ◽  
Author(s):  
R. Stewart ◽  
M. Lako ◽  
G. M. Horrocks ◽  
S. A. Przyborski
Keyword(s):  
Stem Cells ◽  
Green Fluorescent Protein ◽  
Neural Development ◽  
Molecular Mechanisms ◽  
Embryonal Carcinoma ◽  
Fluorescent Protein ◽  
Cell Types ◽  
Green Fluorescent

For many years, researchers have investigated the fate and potential of neuroectodermal cells during the development of the central nervous system. Although several key factors that regulate neural differentiation have been identified, much remains unknown about the molecular mechanisms that control the fate and specification of neural subtypes, especially in humans. Human embryonal carcinoma (EC) stem cells are valuable research tools for the study of neural development; however, existing in vitro experiments are limited to inducing the differentiation of EC cells into only a handful of cell types. In this study, we developed and characterized a novel EC cell line (termed TERA2.cl.SP12-GFP) that carries the reporter molecule, green fluorescent protein (GFP). We demonstrate that TERA2.cl.SP12-GFP stem cells and their differentiated neural derivatives constitutively express GFP in cells grown both in vitro and in vivo. Cellular differentiation does not appear to be affected by insertion of the transgene. We propose that TERA2.cl.SP12-GFP cells provide a valuable research tool to track the fate of cells subsequent to transplantation into alternative environments and that this approach may be particularly useful to investigate the differentiation of human neural tissues in response to local environmental signals.

scholarly journals Stem cells: an origin and marks

2020 ◽  
Vol 22 (2) ◽  
pp. 211-216
Author(s):  
A. V. Moskalev ◽  
B. Y. Gumilevskiy ◽  
A. V. Apchel ◽  
V. N. Cygan
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Molecular Marker ◽  
Population Level ◽  
Cell Types ◽  
Stem Cell Marker ◽  
Wide Range ◽  
Almost All

The basic physiological functions of stem cells are given: the ability to reproduce and generate offspring, which are manifested at the level of the population, and not of a single cell. The manifestation of these functions depends on the quantitative and qualitative composition of the microenvironment. Stem cells consist of two fundamentally different types: pluripotent, which exist only in vitro (in vitro) and tissue, existing in the postpartum body (in vivo). Stem cells can be replaced without limitation in vitro and lead to the appearance of a wide range of cell types. Tissue stem cells under normal conditions do not generate cells characteristic of other types of tissue. Stem cells include cells capable of expressing the gene products characteristic of them. However, there is no universal marker to differentiate stem cells from non-stem cells. A key marker of pluripotency is the transcription factor - a pituitary-specific transcription factor is positive. A component that can be found in almost all types of stem cells is the telomerase complex. Another stem cell marker is called CD34 glycoprotein. The functional activity of stem cells is associated with a molecular marker referred to as leucine-rich repeat containing G-protein bound to receptor 5. However, other types of cells do not express this marker. The physiological capabilities of stem cells depend both on the cells themselves and on their environment. The most reliable way to identify stem cells is to determine their phenotype in vivo. This suggests that stem cells do not carry a universal molecular marker. Most likely, they have significant differences from transplanted cells, and these differences cannot always be detected in individual cells, but only at the population level.

scholarly journals Kinases of the Focal Adhesion Complex Contribute to Cardiomyocyte Specification

2021 ◽  
Vol 22 (19) ◽  
pp. 10430
Author(s):  
Sacha Robert ◽  
Marcus Flowers ◽  
Brenda M. Ogle
Keyword(s):  
Stem Cells ◽  
Focal Adhesion ◽  
Pluripotent Stem Cells ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Culture Conditions ◽  
Model Systems ◽  
Critical Components

Differentiation of pluripotent stem cells to cardiomyocytes is influenced by culture conditions including the extracellular matrices or similar synthetic scaffolds on which they are grown. However, the molecular mechanisms that link the scaffold with differentiation outcomes are not fully known. Here, we determined by immunofluorescence staining and mass spectrometry approaches that extracellular matrix (ECM) engagement by mouse pluripotent stem cells activates critical components of canonical wingless/integrated (Wnt) signaling pathways via kinases of the focal adhesion to drive cardiomyogenesis. These kinases were found to be differentially activated depending on type of ECM engaged. These outcomes begin to explain how varied ECM composition of in vivo tissues with development and in vitro model systems gives rise to different mature cell types, having broad practical applicability for the design of engineered tissues.

186 BOVINE AMNIOTIC FLUID MESENCHYMAL STEM CELLS CHARACTERIZATION AFTER CULTURE IN VITRO

2014 ◽  
Vol 26 (1) ◽  
pp. 207
Author(s):  
B. Rossi ◽  
B. Merlo ◽  
E. Iacono ◽  
P. P. Pagliaro ◽  
P. L. Tazzari ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Amniotic Fluid ◽  
Cell Types ◽  
Calcium Deposition ◽  
Cell Populations ◽  
Rt Pcr ◽  
Differentiation Potential ◽  
Phenotypic Characterisation

In recent years, fetal adnexa and fluids have been recognised as important sources of mesenchymal stem cells (MSC). The aim of this study was to characterise cell populations of bovine amniotic fluid, studying phenotypic characterisation, RNA expression, and differentiation potential of samples after in vitro culture for different lengths of time following trypsinization and expansion (passage). Amniotic fluid samples were recovered at the slaughterhouse from 25 pregnant cows and harvested cells were cultured in DMEM-TCM199 (1 : 1) plus 10% fetal bovine serum (FBS) in 5% CO2 at 38.5°C. At passages P3 and P7, a sample for each of the 4 population found was characterised. Immunophenotypic characterisation was performed for MSC (CD90, CD105, CD44) and haematopoietic (CD14, CD34) markers by flow cytometry (FACS). Immunocytochemistry (ICC) was performed for Oct4, SSEA4, and α-SMA and the ratio between positive cells and total nuclei was evaluated. Gene expression profile was analysed by RT–PCR for pluripotency markers (Oct4, Nanog, Sox2). At the same passages chondrogenic, osteogenic and adipogenic differentiation were induced and evaluated morphologically and cytologically using, respectively, Alcian blue to identify cartilage matrix, Von Kossa for extracellular calcium deposition, and Oil Red O for intracellular lipid droplets. Cell population appeared heterogeneous and we could identify 2 main cell types: round (R) and spindle-shaped (S) cells. Each isolated sample was classified into one of the following 4 types depending on percentages of R or S cells: prevalence of S-cells (S), prevalence of R-cells (R), and samples showing both morphologies with ~10% of S-cells (S10) or 40% S-cells (S40). S-cells percentage decreased with passages in S10 and S40. After FACS, all lines were positive for CD90, CD105, CD44, and CD34 and negative for CD14 both at P3 and at P7. After ICC, Oct4 was negative in all samples analysed, few S cells stained for SSEA4 (8%) at P3 but increased at P7 to 22%; R, S10, and S40 did not express SSEA4 both at P3 and at P7. α-SMA was expressed in all samples at P3 (9.4% S; 0.9% R; 2.5% S10; 27% S40) but not at P7 (27.5% S; 0% R; 0% S10; 0% S40). After RT–PCR analyses, Oct4 was negative in all samples; at P3, Nanog was clearly positive in S-cells, weak in S40, and negative in R and S10, but all samples turned negative at P7. Sox2 was weakly expressed (S) or not expressed (S10, S40, R) at P3 and it was negative in all cells at P7. Only S showed high differentiation potential into all 3 lineages at both P3 and P7, R had the lowest differentiation potential, whereas S10 and S40 were intermediate at both end points. In conclusion, bovine amniotic fluid showed heterogeneous cell populations and S-type had the characteristics of MSCs. S10 and S40 showed more MSC markers at P3, when S cells were still present, and this aspect suggests that S population is the presumptive MSC one. Although prevalent, R-type showed only some MSC characteristics. Further studies are under way to improve S-type isolation, purification, and culture, and to determine the lifespan of these cell types. This work was supported by grant PRIN2009.

313 UNSORTED, FRESHLY ISOLATED PORCINE ADIPOSE-DERIVED STEM CELLS ARE MORE EFFICACIOUS IN BONE HEALING COMPARED WITH PURIFIED CD34+ ADIPOSE-DERIVED STEM CELLS

2011 ◽  
Vol 23 (1) ◽  
pp. 253
Author(s):  
M. Bionaz ◽  
T. Jensen ◽  
E. Monaco ◽  
Z. Dymon ◽  
A. J. Maki ◽  
...  
Keyword(s):  
Stem Cells ◽  
Random Effect ◽  
Cell Types ◽  
Cell Populations ◽  
Adipose Derived Stem Cells ◽  
Cd34 Cells ◽  
Vitro Data ◽  
In Vitro Data

We have previously shown that heterologous transplantation of porcine adipose-derived stem cells (ADSC) enhances bone healing. Freshly harvested ADSC are a heterogeneous population that contains several types of cells other than stem cells. The isolation of highly purified ADSC could be of clinical importance. In this study, we compared the in vitro growth characteristics and in vivo healing potential of ADSC unsorted or separated using CD34 as a marker. The ADSC were extracted from the back fat of 4 male pigs at 6 months of age. For the in vitro experiment, aliquots of the ADSC were sorted by magnetic beads (Miltenyi Biotec, Gladbach, Germany) into CD34-positive (CD34+) and CD34-negative (CD34–) cell populations. The unsorted ADSC (uADSC), plus the CD34+, CD34–, and a 50:50 mixture of CD34+ and CD34– (MIX) were plated in 24-well plates and differentiated into osteocytes. A robotic stage inverted microscope was used to photograph the entire culture well, and then number, dimension, and density of bone nodules were assessed. Alizarin red (AR) staining was performed and quantified. Cells were harvested before cell plating and then on several time points during expansion, at confluence, and at 3, 6, or 18 days [d] of differentiation for cell counting and RNA extraction. Real-time RT-PCR was performed for CD34, COL1A1, and SPARC genes. For the in vivo experiment, freshly isolated ADSC were sorted by flow cytometry into CD34+ and CD34– cell populations. Unsorted and sorted cells were transplanted, in duplicate, into 10- or 25-mm mandible osteoctomies. Mandibles were harvested after 8 weeks for evaluation of healing by DEXA scanning. In vitro data were statistically analysed using a mixed model (SAS) with time and cell type as fixed effect and pig as the random effect. The in vivo data were assessed by ANOVA with cell types as the fixed effect and pig as the random effect. Freshly harvested ADSC contained 42.3 ± 11.0% CD34+ cells. The uADSC reached confluence at 6 days after plating, whereas other cell types reached confluence at 16 days. Expression of CD34 decreased after plating but was similar between cell types. Among osteogenic genes, only expression of SPARC increased during differentiation. The number of osteogenic nodules was higher (P < 0.05) in uADSC than the in other cell types, but the area and nodule density were similar to CD34– and greater (P < 0.05) than CD34+ and MIX. The amount of AR was higher (P < 0.05) in uADSC compared with CD34– and MIX but similar to CD34+. In the in vivo trial, uADSC had a greater (P < 0.05) healing compared with sorted cells. Among those, CD34– cells appeared to increase healing compared with CD34+ cells. Results indicate that CD34+ cells do not differ significantly from CD34– in the in vitro osteogenic differentiation but have lower in vivo healing capacity; however, in vitro data were confused by a lack of pure CD34– cells. The freshly isolated ADSC have a greater healing capacity than sorted cells, as indicated by in vitro and in vivo experiments. Overall our data indicate that the sorting of ADSC CD34+ cells is not of clinical relevance.

The potential of small chemical functional groups for directing the differentiation of kidney stem cells

2010 ◽  
Vol 38 (4) ◽  
pp. 1062-1066 ◽  
Author(s):  
Patricia Murray ◽  
Krasimir Vasilev ◽  
Cristina Fuente Mora ◽  
Egon Ranghini ◽  
Hayeit Tensaout ◽  
...  
Keyword(s):  
Stem Cells ◽  
Kidney Disease ◽  
Functional Groups ◽  
Renal Cell ◽  
Drug Targets ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Kidney Stem Cells ◽  
Small Chemical

In the future, stem-cell-based therapies could offer new approaches to treat kidney disease and reduce the incidence of ESRD (end-stage renal disease), but, as yet, research in this area is only being conducted in rodents and it is not clear whether or when it could be applied to human patients. Drug therapies, on the other hand, have been very effective at delaying the progression of kidney disease, but, for various reasons, current drug regimes are not suitable for all patients. A greater understanding of the molecular mechanisms that underlie disease progression in chronic kidney disease could help to identify novel drug targets. However, progress in this area is currently hindered due to the lack of appropriate in vitro culture systems for important renal cell types, such as proximal tubule cells and podocytes. This problem could be overcome if it were possible to direct the differentiation of kidney stem cells to renal cell types in vitro. In the present review, we highlight the potential of surface gradients of small chemical functional groups to direct the differentiation of kidney stem cells.

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