Conditioned Medium from Hypoxic Bone Marrow-Derived Mesenchymal Stem Cells Enhances Wound Healing in Mice

Abstract

Growing evidence indicates that bone marrow-derived mesenchymal stem cells (BM-MSCs) enhance wound repair via paracrine. Because the extent of environmental oxygenation affects the innate characteristics of BM-MSCs, including their stemness and migration capacity, the current study set out to elucidate and compare the impact of normoxic and hypoxic cell-culture conditions on the expression and secretion of BM-MSC-derived paracrine molecules (e.g., cytokines, growth factors and chemokines) that hypothetically contribute to cutaneous wound healing in vivo. Semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) analyses of normoxic and hypoxic BM-MSCs and their conditioned medium fractions showed that the stem cells expressed and secreted significantly higher amounts of basic fibroblast growth factor (bFGF),vascular endothelial growth factor A (VEGF-A) interleukin 6 (IL-6) and interleukin 8 (IL-8) under hypoxic conditions. Moreover, hypoxic BM-MSC-derived conditioned medium (hypoCM) vs. normoxic BM-MSC-derived conditioned medium (norCM) or vehicle control medium significantly enhanced the proliferation of keratinocytes, fibroblasts and endothelial cells, the migration of keratinocytes, fibroblasts, endothelial cells and monocytes, and the formation of tubular structures by endothelial cells cultured on Matrigel matrix. Consistent with these in vitro results, skin wound contraction was significantly accelerated in Balb/c nude mice treated with topical hypoCM relative to norCM or the vehicle control. Notably increased in vivo cell proliferation, neovascularization as well as recruitment of inflammatory macrophages and evidently decreased collagen I, and collagen III were also found in the hypoCM-treated group. These findings suggest that BM-MSCs promote murine skin wound healing via hypoxia-enhanced paracrine.

Physiologically Low Oxygen Enhances Biomolecule Production and Stemness of Mesenchymal Stem Cell Spheroids

“…This increase was similar to levels reported by Lee et al with a 2.8-and 2.3-fold increase of VEGF and bFGF, respectively, for adipose-derived stem cells under 2% oxygen flat culture for 72 h. 42 The hypoxic treatment of hMSCs also significantly increased VEGF by 2.56 fold and bFGF expression by 3.33 fold. 43 VEGF had also been shown to be increased in spheroids formed on chitosan films for 7 days, with a 1.2-fold increase in VEGF, but with no significant change in bFGF. 44 This increase of growth factors due to low oxygen culture and 3D condition could in turn activate the collagen synthesis and migration of fibroblasts, leading to enhanced wound healing.…”

Alginate and DNA Gels Are Suitable Delivery Systems for Diabetic Wound Healing

“…Also, the gene expression profile of the transplanted cells is crucial for their therapeutic effect. [17][18][19] Therefore, next-generation delivery systems should protect bioactive agents in the wound environment, provide sustained release of the bioactive molecules, and adequately modulate the fate, location, and phenotype of transplanted cells.…”

Mesenchymal Stem Cell Therapy in Type 1 Diabetes Mellitus and Its Main Complications: From Experimental Findings to Clinical Practice

“…Nevertheless, most studies agree that although MSCs can migrate to injury sites in response to chemotactic signals in vivo [126,127], only a small percentage of engrafted MSCs actually become incorporated and survive within damaged tissue [128]. On the other hand, other studies have revealed that transplanted MSCs do not necessarily have to be in close proximity to damaged tissue to promote wound repair and functional recovery, thereby suggesting that paracrine factor secretion is the main MSC therapeutic action concerned in repairing skin disorders [129,130]. This theory has been further reinforced by recent studies which have shown that allogeneic MSCs-conditioned medium has enhanced healing when administered locally into wounds [121,122,[131][132][133][134].…”