Estudio del efecto terapéutico de las células mesenquimales de la gelatina de Wharton del cordón umbilical humano en un modelo murino de cicatrización de heridas

Abstract

ABSTRACT STUDY OF THE THERAPEUTIC EFFECT OF HUMAN WHARTON'S JELLY MESENCHYMAL STEM CELLS IN AN EXPERIMENTAL MURINE MODEL OF WOUND HEALING. Introduction: the skin is the largest organ in the human body. Cutaneous wounds are the result of disrupted skin integrity. Mesenchymal stem cells (MSCs) are emerging as a promising candidate for cell-based therapy for the treatment of chronic wounds because of their enormous potential for enhancing tissue repair and regeneration following injury. Silk fibroin cellularized with MSCs from different sources has been shown to be effective in repairing experimental wounds of the skin. Objectives: to investigate the behavior of Wharton's jelly mesenchymal stem cells (Wj-MSCs) both in vitro and in vivo when cultivated on electrospun silk fibroin scaffolds and implanted in immunocompetent mice. To determine whether Wj-MSCs delivered in silk fibroin scaffolds into skin defects in SKH1 mice would contribute to dermal wound healing. Methodology: we have first standardized the protocol for the isolation and characterization of Wj-MSCs. Further, these MSCs along with the combination of silk fibroin scaffolds were used to test their wound healing properties by creating skin wounds in an experimental murine model. Results: Wj-MSCs exhibited a fibroblastic morphology and displayed MSC surface markers positive for CD90, CD105, CD73 with no detectable presence of hematopoietic cells markers. Wj-MSCs were limited on their ability to differentiate into adipocytes, chondrocytes, and osteoblasts. Wj-MSCs suppressed T cell proliferation after stimulation with anti-CD3/CD28 coated beads and allogeneic mDCs. Wj-MSCs downmodulated the in vitro production of the pro-inflammatory cytokine IFN- by activated T lymphocytes. This immunosuppressive effect was also mediated by the production of the anti-inflammatory cytokines TGF- , IDO, and PGE2. MLCs experiments in the presence of different specific inhibitors of the biosynthesis or signaling of these anti-inflammatory factors such as SB-431542, indomethacin (IDM) or 1-methyl-tryptophan (1-MT), respectively, recovered almost entirely the proliferation rate of mDCs-stimulated T cells. Treatment of skin injury of SKH1 mice model demonstrated that combination of Wj-MSCs and silk fibroin scaffold exhibited significantly better wound-healing capabilities. Conclusions: Wj-MSCs have reduced immunogenicity, did not express costimulatory molecules, and express cytokines that may modulate immune function. Wharton's jelly MSCs combined with silk fibroin scaffolds in the wound bed contributed to the generation of a high-quality, well-vascularized granulation tissue, enhanced re-epithelialization of the wound, and attenuated the formation of fibrotic scar tissue. Wharton's jelly from the human umbilical cord may be an adequate source for obtaining MSCs for wound healing given its several advantages and together with the synergistic benefits of a nanoscaffold they make ideal combinations as wound dressings for slow healing and hard-to-heal chronic wounds. Keywords: mesenchymal stem cells, Wharton's jelly, umbilical cord, wound healing.