Complement Activation and STAT4 Expression Are Associated with Early Inflammation in Diabetic Wounds

Area of Science:

• Immunology
• Wound Healing
• Diabetic Complications

Background:

• Diabetic non-healing wounds are a significant clinical challenge, often linked to unresolved inflammation.
• The complement system (CS) and Signal transducer and activator of transcription 4 (STAT4) are implicated in inflammatory processes and potentially in impaired wound healing.

Purpose of the Study:

• To investigate the role of the complement system (CS) and STAT4 in early-stage diabetic skin wounds.
• To characterize the expression and activation of CS and STAT4 in a mouse model of diabetic wounds.

Main Methods:

• Utilized db/db mice as a model for diabetic skin wounds.
• Assessed complement activation via C5a levels and C3 fragment deposition.
• Evaluated the effect of a complement inhibitor (PIC1) on inflammation and leukocyte infiltration.
• Measured STAT4, CCL2, and CCR2 expression in wound tissues.

Main Results:

• Complement system activation was evident early in diabetic wounds, indicated by increased C5a and C3 deposition.
• Diabetic wounds exhibited a significant increase in nucleated cells compared to controls.
• STAT4, CCL2, and CCR2 expression were significantly elevated in early diabetic wounds.
• PIC1 treatment reduced inflammation and leukocyte infiltration in the wounds.

Conclusions:

• Early activation of the complement system and STAT4 contributes to unresolved inflammation in diabetic wounds.
• Targeting the complement system and STAT4 presents a promising therapeutic strategy for improving diabetic wound healing.