Evaluation of tenogenic differentiation potential of selected subpopulations of human adipose‐derived stem cells

Adipose-derived mesenchymal stem cells have become a popular cell choice for tendon repair strategies due to their relative abundance, ease of isolation, and ability to differentiate into tenocytes. In this study, we investigated the solo effect of different uniaxial tensile strains and loading frequencies on the matrix directionality and tenogenic differentiation of adipose-derived stem cells encapsulated within three-dimensional collagen scaffolds. Samples loaded at 0%, 2%, 4%, and 6% strains and 0.1 Hz and 1 Hz frequencies for 2 hours/day over a 7-day period using a custom-built uniaxial tensile strain bioreactor were characterized in terms of matrix organization, cell viability, and musculoskeletal gene expression profiles. The results displayed that the collagen fibers of the loaded samples exhibited increased matrix directionality with an increase in strain values. Gene expression analyses demonstrated that ASC-encapsulated collagen scaffolds loaded at 2% strain and 0.1 Hz frequency showed significant increases in extracellular matrix genes and tenogenic differentiation markers. Importantly, no cross-differentiation potential to osteogenic, chondrogenic, and myogenic lineages was observed at 2% strain and 0.1 Hz frequency loading condition. Thus, 2% strain and 0.1 Hz frequency were identified as the appropriate mechanical loading regime to induce tenogenic differentiation of adipose-derived stem cells cultured in a three-dimensional environment.

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A NOTCH1/LSD1/BMP2 co-regulatory network mediated by miR-137 negatively regulates osteogenesis of human adipose-derived stem cells

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02495-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Cong Fan ◽

Xiaohan Ma ◽

Yuejun Wang ◽

Longwei Lv ◽

Yuan Zhu ◽

...

Keyword(s):

Stem Cells ◽

Osteoblastic Differentiation ◽

Negative Control ◽

Bone Morphogenetic Protein 2 ◽

Luciferase Reporter ◽

Adipose Derived Stem Cells ◽

Differentiation Potential ◽

Lineage Differentiation ◽

Morphogenetic Protein ◽

Genes Expression

Abstract Background MicroRNAs have been recognized as critical regulators for the osteoblastic lineage differentiation of human adipose-derived stem cells (hASCs). Previously, we have displayed that silencing of miR-137 enhances the osteoblastic differentiation potential of hASCs partly through the coordination of lysine-specific histone demethylase 1 (LSD1), bone morphogenetic protein 2 (BMP2), and mothers against decapentaplegic homolog 4 (SMAD4). However, still numerous molecules involved in the osteogenic regulation of miR-137 remain unknown. This study aimed to further elucidate the epigenetic mechanisms of miR-137 on the osteogenic differentiation of hASCs. Methods Dual-luciferase reporter assay was performed to validate the binding to the 3′ untranslated region (3′ UTR) of NOTCH1 by miR-137. To further identify the role of NOTCH1 in miR-137-modulated osteogenesis, tangeretin (an inhibitor of NOTCH1) was applied to treat hASCs which were transfected with miR-137 knockdown lentiviruses, then together with negative control (NC), miR-137 overexpression and miR-137 knockdown groups, the osteogenic capacity and possible downstream signals were examined. Interrelationships between signaling pathways of NOTCH1-hairy and enhancer of split 1 (HES1), LSD1 and BMP2-SMADs were thoroughly investigated with separate knockdown of NOTCH1, LSD1, BMP2, and HES1. Results We confirmed that miR-137 directly targeted the 3′ UTR of NOTCH1 while positively regulated HES1. Tangeretin reversed the effects of miR-137 knockdown on osteogenic promotion and downstream genes expression. After knocking down NOTCH1 or BMP2 individually, we found that these two signals formed a positive feedback loop as well as activated LSD1 and HES1. In addition, LSD1 knockdown induced NOTCH1 expression while suppressed HES1. Conclusions Collectively, we proposed a NOTCH1/LSD1/BMP2 co-regulatory signaling network to elucidate the modulation of miR-137 on the osteoblastic differentiation of hASCs, thus providing mechanism-based rationale for miRNA-targeted therapy of bone defect.

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Tetrahedral framework nucleic acids regulate osteogenic differentiation potential of osteoporotic adipose-derived stem cells

Chinese Chemical Letters ◽

10.1016/j.cclet.2021.11.090 ◽

2021 ◽

Author(s):

Tianyu Chen ◽

Dexuan Xiao ◽

Yanjing Li ◽

Sirong Shi ◽

Xiao Yang ◽

...

Keyword(s):

Stem Cells ◽

Nucleic Acids ◽

Osteogenic Differentiation ◽

Adipose Derived Stem Cells ◽

Differentiation Potential ◽

Tetrahedral Framework

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High glucose induces early senescence in adipose-derived stem cells by accelerating p16 and mTOR

Biomedical Research and Therapy ◽

10.15419/bmrat.v6i6.548 ◽

2019 ◽

Vol 6 (6) ◽

pp. 3213-3221

Author(s):

Hieu Liem Pham ◽

Phuc Van Pham

Keyword(s):

Stem Cells ◽

High Glucose ◽

Glucose Concentration ◽

Culture Medium ◽

Diabetic Patients ◽

Adipose Derived Stem Cells ◽

Differentiation Potential ◽

Normal Glucose

Introduction: The senescence of stem cells is the primary reason that causes aging of stem cell-containing tissues. Some hypotheses have suggested that high glucose concentration in diabetic patients is the main factor that causes senescence of cells in those patients. This study aimed to evaluate the effects of high glucose concentrations on the senescence of adipose-derived stem cells (ADSCs). Methods: ADSCs were isolated and expanded from human adipose tissues. They were characterized and confirmed as mesenchymal stem cells (MSCs) by expression of surface markers, their shape, and in vitro differentiation potential. They were then cultured in 3 different media- that contained 17.5 mM, 35 mM, or 55 mM of D-glucose. The senescent status of ADSCs was recorded by the expression of the enzyme beta-galactosidase, cell proliferation, and doubling time. Real-time RT-PCR was used to evaluate the expression of p16, p21, p53 and mTOR. Results: The results showed that high glucose concentrations (35 mM and 55 mM) in the culture medium induced senescence of human ADSCs. The ADSCs could progress to the senescent status quicker than those cultured in the lower glucose-containing medium (17.5 mM). The senescent state was related to the up-regulation of p16 and mTOR genes. Conclusion: These results suggest that high glucose in culture medium can trigger the expression of p16 and mTOR genes which cause early senescence in ADSCs. Therefore, ADSCs should be cultured in low glucose culture medium, or normal glucose concentration, to extend their life in vitro as well as in vivo.

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