Changes in cellular motility and cytoskeletal actin in fibroblasts from patients with chronic venous insufficiency and in neonatal fibroblasts in the presence of chronic wound fluid

Abstract

Purpose: Fibroblasts (fb) play an important role in wound healing involving motility, contraction, fibrosis, and expression of the cytoskeletal protein α-smooth muscle actin (α-sma). Patients with chronic venous insufficiency (CVI) are known to have dermal changes and impaired venous ulcer healing. To investigate whether these dermal-fb have an altered ability to migrate and whether chronic wound fluid from venous ulcers alters neonatal fb motility, we examined cell migration and α-sma. Methods: Fibroblasts were cultured from the margin of venous ulcers (du-fb, n = 4, CEAP 6), from patients with venous reflux without ulcer (dr-fb, n = 5, CEAP 2), and from the ipsilateral thigh of the same patients with (pu-fb) and without (pr-fb) ulcer, respectively. The abbreviations used are p and d, which represent proximal and distal, respectively; u and r represent ulcer and reflux, respectively. Neonatal foreskin fibroblasts (nf-fb) were exposed to chronic venous ulcer wound fluid (CVUWF, 300 μg protein/mL, n = 3) or bovine serum albumin (BSA, control). Fibroblast motility was determined by means of time-lapse photo-images, and the rate (micrometer per hour) was calculated. Immunohistochemistry for α-sma was analyzed with confocal laser microscopy. Results: The rate of motility (micrometer per hour ± SEM) was decreased for both du-fb (11.4 ± 0.7) and dr-fb (13.8 ± 0.6), when compared with pu-fb (21.9 ± 0.9) and pr-fb (24.7 ± 1.1), respectively. The motility rate for nf-fb was lower in CVUWF (24.7 ± 2.0) than in BSA (37.1 ± 6.7). An elevated level of microfilament bundles of α-sma for both du-fb and dr-fb, compared with those of pu-fb and pr-fb, and also in nf-fb treated with CVUWF was demonstrated by means of immunohistochemistry. Conclusion: These data demonstrate a reduced motility in the dermal fb of patients with CVI. Patients with reflux disease without ulcer are predisposed to these changes. Furthermore, it appears that CVUWF causes changes in motility and α-sma expression in nf-fb as demonstrated in du-fb. These findings suggest that reduced motility and CVUWF, representing the microenvironment of venous ulcers, play a significant role in impaired wound healing.