Cutaneous wound healing effects of mesenchymal stromal cells and sheets overexpressing platelet-derived growth factor in dogs

Abstract

지방 유래 중간엽 줄기세포는 창상 치유에 탁월한 잠재력을 가지고 있다. 또한 혈소판유래성장인자는 각 치유 단계에 중요한 역할을 하며, 정상 피부와 손상된 피부에 강력한 창상 치유 능력을 갖는다. 본 연구는 혈소판유래성장인자 과발현 중간엽줄기세포 (PDGF-MSCs)와 시트 (PDGF-CS), 미분화중간엽줄기세포 (U-MSCs)와 시트 (UCS)의 개 피부 창상 치유능력을 다각도로 비교하였다. 각 세포와 시트의 실험실적 비교에서, PDGF-MSCs와 PDGF-CS의 PDGF-B 분비가 200 배 상승하였음을 확인하였다. 개 피부창상모델 통한 육안적 비교에서, 모든 세포와 시트 적용군의 창상치유가 촉진되었으며 (p < 0.05), 조직학적 비교에서 특히 PDGF-MSCs 적용군에서 상피율의 상피세포증식에 유의적 증가가 확인되었다 (p < 0.05). 육아조직에서, PDGF-CS 와 UCS 적용군의 육아조직 상층 조직형성, 콜라겐 침착, 활성화 섬유아세포 형성이 PDGF-MSCs, U-MSCs 적용군 보다 유의적으로 높았다 (p < 0.05). 특히 PDGF-CS 적용군이 가장 많은 육아조직 형성과 성숙도를 보였다. 결론적으로 PDGF-MSCs는 상피형성에 가장 큰 촉진작용을 보였으며, PDGF-CS는 육아조직형성과 성숙에 가장 높은 작용을 보여줬다. 따라서 PDGF 과발현 세포와 시트는 개 창상치유에 효과적인 치료 방법으로 시도 될 수 있다.

Adipose derived mesenchymal stem cells (Ad-MSCs) have excellent potential for use in skin repair. In addition, platelet derived growth factor (PDGF), which plays a key role at each stage of the healing process, has strong wound healing properties for normal and impaired tissues. The purpose of the present study was to compare the healing effects of PDGF-overexpressing Ad-MSCs (PDGF-MSCs) and their sheets (PDGF-CSs) with undifferentiated Ad-MSC (U-MSCs) and sheets (UCSs) on cutaneous wounds in dogs. For the in vitro study, all stem cells and sheets were analyzed by real-time quantitative reverse transcription polymerase chain reaction (real-time qRT-PCR). For the in vivo study, cells and sheets were transplanted into a square full-thickness (1.5 × 1.5 cm) skin defect model in 12 dogs, respectively. After 5 and 10 days, wounds were harvested and evaluated macroscopically and histopathologically. The PDGF-B gene was significantly 200-fold upregulated in PDGF-CS and PDGF-MSCs groups. Upon gross analysis, all stem cells and their sheets showed accelerated cutaneous wound healing (p < 0.05). PDGF groups, especially PDGF-MSCs, showed significantly increased epithelialization histopathologically (p < 0.05). In granulation tissue, the sheets, PDGF-CSs and UCSs, promoted more upper tissue formation and deposition of collagen and activated fibroblasts than the cells, PDGF-MSCs and U-MSCs (p < 0.05). Especially, the PDGF-CS presented the most formation and maturation of granulation tissue. The PDGF-CS showed the most granulation tissue formation and maturation, and intradermal injection of PDGF-MSCs accelerated keratinocyte proliferation and epithelialization the most.