Potential Mechanisms of the Impact of Hepatocyte Growth Factor Gene-Modified Tendon Stem Cells on Tendon Healing.
Front Cell Dev Biol
; 9: 659389, 2021.
Article
em En
| MEDLINE
| ID: mdl-34222233
ABSTRACT
The therapeutic impact of stem cells is potentially largely attributable to secretion of exosomes and soluble factors. The present study evaluates the impact of hepatocyte growth factor (HGF)-expressing tendon stem cells (TSCs) on tendon healing in a rat model. Patellar tendon TSCs were isolated and underwent transfection with lentiviral vectors containing HGF or green fluorescent protein (GFP) genes. In vivo, immunohistochemistry of tendons sampled 1 week postsurgery demonstrated that all stem cell-treated groups exhibited higher numbers of CD163+ M2 monocytes and IL-10+ cells (anti-inflammatory), and lower numbers of CCR7+ M1 monocytes and IL-6+ as well as COX-2+ cells (pro-inflammatory). Effects were most pronounced in the HGF-expressing TSCs (TSCs + HGF) treated group. Histology ± immunohistochemistry of tendons sampled 4 and 8 weeks postsurgery demonstrated that all stem cell-treated groups exhibited more ordered collagen fiber arrangement and lower levels of COLIII, α-SMA, TGF-ß1, and fibronectin (proteins relevant to fibroscarring). Effects were most pronounced in the TSCs + HGF-treated group. For the in vitro study, isolated tendon fibroblasts pretreated with TGF-ß1 to mimic the in vivo microenvironment of tendon injury were indirectly cocultured with TSCs, TSCs + GFP, or TSCs + HGF using a transwell system. Western blotting demonstrated that all stem cell types decreased TGF-ß1-induced increases in fibroblast levels of COX-2, COLIII, and α-SMA, concomitant with decreased activation of major TGF-ß1 signaling pathways (p38 MAPK, ERK1/2, but not Smad2/3). This effect was most pronounced for TSCs + HGF, which also decreased the TGF-ß1-induced increase in activation of the Smad2/3 signaling pathway. The presence of specific inhibitors of these pathways during fibroblast TGF-ß1 stimulation also attenuated increases in levels of COX-2, COLIII, and α-SMA. In conclusion, TSCs + HGF, which exhibit HGF overexpression, may promoting tendon healing via decreasing inflammation and fibrosis, perhaps partly via inhibiting TGF-ß1-induced signaling. These findings identify a novel potential therapeutic strategy for tendon injuries, warranting additional research.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
China