Protomyofibroblast Pathway in Early Thermal Burn Healing

Area of Science:

• Dermatology
• Wound Healing Research
• Cell Biology

Background:

• Partial thickness thermal burns risk hypertrophic scarring.
• Increased skin myofibroblast (MF) density is common in burn healing.
• Cellular transitions from monocytes to fibrocytes and myofibroblasts are proposed in scar formation.

Purpose of the Study:

• To investigate the cellular dynamics during wound healing in partial thickness thermal burns.
• To identify the presence and density of specific cell types, including protomyofibroblasts (PMF) and myofibroblasts (MF), in burn wound healing.
• To explore the potential cellular origins of MF in burn scars.

Main Methods:

• Skin biopsies from 25 burn patients were collected at 1 and 4 weeks post-injury.
• Immunohistochemistry was utilized to detect various cell markers including α-SMA, β-SMA, CD14, CD34, and factor XIIIa.
• Analysis focused on the density and distribution of monocytes, fibrocytes, dendrocytes, PMF, MF, and endothelial cells.

Main Results:

• Mac 387+ and CD14+ monocytes were observed alongside CD34+ fibrocytes and factor XIIIa+ dendrocytes.
• β-SMA+ protomyofibroblasts (PMF) were found to be rare in the healing burn wounds.
• α-SMA+ myofibroblasts (MF) showed significantly higher abundance at week 4 compared to week 1 (p < 0.01).

Conclusions:

• Partial thickness thermal burn healing involves diverse cell types, including PMF.
• The density of protomyofibroblasts (PMF) remained low in the studied burn wound samples.
• The increased presence of α-SMA+ myofibroblasts (MF) over time suggests their role in later stages of burn wound healing.