Diabetic wound healing in a MMP9-/- mouse model

Area of Science:

• Wound healing research
• Cellular and molecular biology
• Regenerative medicine

Background:

• Chronic wounds exhibit reduced endothelial progenitor cell (EPC) mobilization and recruitment, hindering healing.
• The precise role of bone marrow-derived EPCs in cutaneous wound neovascularization and healing requires further elucidation.
• Current understanding limitations impede the development of effective EPC-based wound healing therapies.

Purpose of the Study:

• To investigate the role of EPCs in wound neovascularization and healing.
• To evaluate wound healing in single (EPC deficiency) and double (EPC + diabetes) deficiency models.
• To determine the efficacy of stem cell factor (SCF) in rescuing impaired wound healing.

Main Methods:

• Utilized a Matrix metalloproteinase 9 knockout (MMP9 KO) mouse model.
• Induced diabetes using streptozotocin in MMP9 KO mice.
• Administered tail-vein injections of SCF in the presence or absence of diabetes.
• Created full-thickness excisional wounds and assessed neovascularization, inflammation, and EPC levels at day 7 postwounding.

Main Results:

• MMP9 deficiency impaired wound neovascularization, increased inflammation, and reduced peripheral blood EPC (pb-EPC) counts.
• Diabetes exacerbated inflammation but did not further impair vascularization in MMP9 KO mice.
• SCF administration improved neovascularization and increased EPC levels to wild-type (WT) levels.
• SCF treatment also exacerbated inflammation across all experimental groups.

Conclusions:

• Bone marrow-derived EPCs play a critical role in wound neovascularization.
• SCF effectively rescues EPC deficiency and improves neovascularization in both diabetic and nondiabetic MMP9 KO mice.
• SCF-based therapy, coupled with controlled inflammation, shows potential for enhancing chronic diabetic wound healing.