Increased Fibronectin Production by Cell Lines from Hypertrophic Scar and Keloid

Abstract

Primary cell lines of fibroblasts from 8 tissues were established--three from hypertrophic scars (HS), one keloid (K) and four from the normal uninvolved dermis adjacent to each lesion. The objective was to quantify and compare all eight cell lines on the basis of fibronectin (FN) produced per cell and per total protein (PR). Two hypertrophic scars and their adjacent skin cell lines were evaluated by the ELISA method for FN and a micro Lowry assay for PR. The scar lines showed statistically significant increases in the amount of FN/cell compared to the cell lines from their adjacent normal dermis. The third hypertrophic scar and the keloid with their adjacent skin cell lines were assayed for FN and PR by radioimmunoprecipitation. Subconfluent cells were metabolically labeled with 35S-methionine for 20 hours. Harvested media and cell monolayers were assayed for radioactivity incorporated into FN and PR. The percentage of FN/PR was significantly higher in media for HS and K compared to the adjacent normal skin lines in the three passages tested. These results support our previous immunofluorescence studies and demonstrate that a fibroblast-type cell line from a hypertrophic scar or keloid produces more FN/PR over time than the normal fibroblast-type cell line from adjacent uninvolved dermis.

Increased Proliferation in Keloid Fibroblasts Woundedin Vitro

“…and this finding has been corroborated by several studies [18][19][20][21][22]. Kischer et al [23] and Babu et al [24] ACKNOWLEDGMENTS have shown that keloid fibroblasts also produce more…”

“…This increased in vitro wounding. Keloid fibroblasts are known to synthesize more collagen and other matrix components in mitogenic response supports previous observations of increased fibroblast activity in vivo in early keloid vitro than do normal dermal fibroblasts under standard culture conditions [17][18][19][20][21][22][23][24]. Cohen et al were the first scars, and suggests that increased keloid-derived fibroblast proliferation in response to wounding contrito demonstrate increased rates of collagen synthesis in keloid cultures compared to normal skin or scar [17], butes to the pathogenesis of keloid scar formation.…”

Anti-Scarring Properties of Different Tryptophan Derivatives

“…Fibronectin is an abundant component of the provisional matrix regulates different aspects of wound healing including cell attachment, migration and differentiation, matrix organization and wound contraction [46]. Exaggerated fibronectin expression and accumulation are pathological features of fibrotic disorders [47], [48], [49], [50]. By acting as a potent chemoattractant [51], fibronectin recruits fibroblasts into the wound bed and induces their differentiation into myofibroblasts [52].…”

Increased Plasminogen Activator Inhibitor-1 in Keloid Fibroblasts May Account for their Elevated Collagen Accumulation in Fibrin Gel Cultures

“…In vitro, keloid fibroblasts exhibit an altered phenotype of either intrinsic or growth factor-stimulated collagen, fibronectin, elastin, and proteoglycan accumulation. [3][4][5][6][7][8][9][10] These alterations may occur at the level of growth factor production, growth factor receptor expression, or postreceptor signal transduction. [11][12][13] Aberrations in cell growth have also been implicated in keloid scar formation and expansion.…”