Differential expression of wound fibrotic factors between facial and trunk dermal fibroblasts

Abstract

Clinically, wounds on the face tend to heal with less scarring than those on the trunk, but the causes of this difference have not been clarified. Fibroblasts obtained from different parts of the body are known to show different properties. To investigate whether the characteristic properties of facial and trunk wound healing are caused by differences in local fibroblasts, we comparatively analyzed the functional properties of superficial and deep dermal fibroblasts obtained from the facial and trunk skin of seven individuals, with an emphasis on tendency for fibrosis. Proliferation kinetics and mRNA and protein expression of 11 fibrosis-associated factors were investigated. The proliferation kinetics of facial and trunk fibroblasts were identical, but the expression and production levels of profibrotic factors, such as extracellular matrix, transforming growth factor-β1, and connective tissue growth factor mRNA, were lower in facial fibroblasts when compared with trunk fibroblasts, while the expression of antifibrotic factors, such as collagenase, basic fibroblast growth factor, and hepatocyte growth factor, showed no clear trends. The differences in functional properties of facial and trunk dermal fibroblasts were consistent with the clinical tendencies of healing of facial and trunk wounds. Thus, the differences between facial and trunk scarring are at least partly related to the intrinsic nature of the local dermal fibroblasts.

Figure 1

Cell morphology of FS, TS, FD, and TD. Phase contrast microscopic findings for FS, TS, FD, and TD from donor No. 4 at 4,12, and 32 days after cell seeding. Scale bar indicates 100 μm.

Figure 2

Cell proliferation of FS, TS, FD, and TD. (A) Chronological cell number in four cell fractions is noted (n = 7 for each). Error bars indicate SEM. (B) Cell count of FS, TS, FD, and TD on day 32 (n = 7 for each). (C) Correlation of saturated cell number between facial and trunk fibroblasts on day 32.

Figure 3

Expression of wound healing-associated factors by FS, TS, FD, and TD. mRNA expression of fibrosis-associated factors by FS, FD, TS, and TD (n = 7, each).

Figure 4

Production of wound healing-associated factors by FS, TS, FD, and TD. Production of type I collagen, TGF-ß1 and TGF-ß2, and CTGF by FS, FD, TS, and TD (for type I collagen, n = 5 for each; for others, n = 6 for each).