scholarly journals Paper of the June Issue of Stem Cell Reviews and Reports Provides Further Evidence that Tissue Physiological Low Oxygen Tension in Contrast to Atmospheric Ambient Oxygen Tension Enhances Competence and Functional Properties of Stem Cells

2021 ◽  
Author(s):  
Mariusz Z. Ratajczak
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Oxygen Tension ◽  
Functional Properties ◽  
Low Oxygen ◽  
Ambient Oxygen ◽  
Low Oxygen Tension

A brief very-low oxygen tension regimen is sufficient for the early chondrogenic commitment of human adipose-derived mesenchymal stem cells

2021 ◽  
Vol 66 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Marco Govoni ◽  
Claudio Muscari ◽  
Francesca Bonafè ◽  
Paolo Giovanni Morselli ◽  
Marilisa Cortesi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Oxygen Tension ◽  
Low Oxygen ◽  
Low Oxygen Tension

scholarly journals Inability of Low Oxygen Tension to Induce Chondrogenesis in Human Infrapatellar Fat Pad Mesenchymal Stem Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Samia Rahman ◽  
Alexander R. A. Szojka ◽  
Yan Liang ◽  
Melanie Kunze ◽  
Victoria Goncalves ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Oxygen Tension ◽  
Endochondral Ossification ◽  
Infrapatellar Fat Pad ◽  
Low Oxygen ◽  
Fat Pad ◽  
Chondrogenic Medium ◽  
Low Oxygen Tension

ObjectiveArticular cartilage of the knee joint is avascular, exists under a low oxygen tension microenvironment, and does not self-heal when injured. Human infrapatellar fat pad-sourced mesenchymal stem cells (IFP-MSC) are an arthroscopically accessible source of mesenchymal stem cells (MSC) for the repair of articular cartilage defects. Human IFP-MSC exists physiologically under a low oxygen tension (i.e., 1–5%) microenvironment. Human bone marrow mesenchymal stem cells (BM-MSC) exist physiologically within a similar range of oxygen tension. A low oxygen tension of 2% spontaneously induced chondrogenesis in micromass pellets of human BM-MSC. However, this is yet to be demonstrated in human IFP-MSC or other adipose tissue-sourced MSC. In this study, we explored the potential of low oxygen tension at 2% to drive the in vitro chondrogenesis of IFP-MSC. We hypothesized that 2% O2 will induce stable chondrogenesis in human IFP-MSC without the risk of undergoing endochondral ossification at ectopic sites of implantation.MethodsMicromass pellets of human IFP-MSC were cultured under 2% O2 or 21% O2 (normal atmosphere O2) in the presence or absence of chondrogenic medium with transforming growth factor-β3 (TGFβ3) for 3 weeks. Following in vitro chondrogenesis, the resulting pellets were implanted in immunodeficient athymic nude mice for 3 weeks.ResultsA low oxygen tension of 2% was unable to induce chondrogenesis in human IFP-MSC. In contrast, chondrogenic medium with TGFβ3 induced in vitro chondrogenesis. All pellets were devoid of any evidence of undergoing endochondral ossification after subcutaneous implantation in athymic mice.

scholarly journals Low-Oxygen Tension and IGF-I Promote Proliferation and Multipotency of Placental Mesenchymal Stem Cells (PMSCs) from Different Gestations via Distinct Signaling Pathways

Endocrinology ◽  
2014 ◽  
Vol 155 (4) ◽  
pp. 1386-1397 ◽  
Author(s):  
Amer Youssef ◽  
Cristiana Iosef ◽  
Victor K.M. Han
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Insulin Receptor ◽  
Oxygen Tension ◽  
Insulin Receptor Substrate ◽  
Low Oxygen ◽  
Insulin Receptor Substrate 1 ◽  
Placental Mesenchymal Stem Cells ◽  
Low Oxygen Tension ◽  
Igf I

The microenvironment of placental mesenchymal stem cells (PMSCs) is dynamic throughout gestation and determines changes in cell fate. In vivo, PMSCs initially develop in low-oxygen tension and low IGF-I concentrations, and both increase gradually with gestation. The impact of varying concentrations of IGF-I and changing oxygen tension on PMSC signaling and multipotency was investigated in PMSCs from early (preterm) and late (term) gestation human placentae. Preterm PMSCs had greater proliferative response to IGF-I, which was further enhanced by low-oxygen tension. Low-oxygen tension alone was sufficient to induce ERK1/2 phosphorylation, whereas IGF-I was required for AKT (protein kinase B) phosphorylation. Low-oxygen tension prolonged ERK1/2 and AKT phosphorylation with a slowed phosphorylation decay even in presence of IGF-I. Low-oxygen tension maintained higher levels of IGF-I receptor and insulin receptor substrate 1 that were otherwise decreased by exposure to IGF-I and induced a differential phosphorylation pattern on IGF-I receptorβ and insulin receptor substrate 1. Phosphorylation of ERK1/2 and AKT was different between the preterm and term PMSCs, and phospho-AKT, and not phospho-ERK1/2, was the major determinant of PMSC proliferation and octamer-4 levels. These studies demonstrate that low-oxygen tension regulates the fate of PMSCs from early and late gestations in response to IGF-I, both independently and dependently, via specific signal transduction mechanisms.

scholarly journals Low Oxygen Tension Modulates the Insulin-Like Growth Factor-1 or -2 Signaling via Both Insulin-Like Growth Factor-1 Receptor and Insulin Receptor to Maintain Stem Cell Identity in Placental Mesenchymal Stem Cells

Endocrinology ◽  
2016 ◽  
Vol 157 (3) ◽  
pp. 1163-1174 ◽  
Author(s):  
Amer Youssef ◽  
Victor K. M. Han
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Growth Factor ◽  
Insulin Receptor ◽  
Oxygen Tension ◽  
Insulin Like Growth Factor ◽  
Low Oxygen ◽  
Placental Mesenchymal Stem Cells ◽  
Low Oxygen Tension

Abstract Placental mesenchymal stem cells (PMSCs) are readily available multipotent stem cells for potential use in regenerative therapies. For this purpose, PMSCs must be maintained in culture conditions that mimic the in vivo microenvironment. IGFs (IGF-1 and IGF-2) and oxygen tension are low in the placenta in early gestation and increase as pregnancy progresses. IGFs bind to two receptor tyrosine kinases, the IGF-1 receptor (IGF-1R) and the insulin receptor (IR), and their hybrid receptors. We hypothesized that IGF-1 and IGF-2 signal via distinct signaling pathways under low-oxygen tension to maintain PMSC multipotency. In preterm PMSCs, low-oxygen tension increased the expression of IGF-2 and reduced IGF-1. IGF-1 stimulated higher phosphorylation of IGF-1Rβ, ERK1/2, and AKT, which was maintained at steady lower levels by low oxygen tension. PMSC proliferation was increased by IGF-1 more than IGF-2,and was potentiated by low-oxygen tension. This IGF/low oxygen tension-mediated proliferation was receptor dependent because neutralization of the IGF-1R inhibited PMSC proliferation in the presence of IGF-1 and the IR in presence of IGF-2. These findings suggest that both IGF-1R and the IR can participate in mediating IGF signaling in maintaining PMSCs multipotency. We conclude that low-oxygen tension can modify the IGF-1 or IGF-2 signaling via the IGF-1R and IR in PMSCs.

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