The 1998 MOYER AWARD. Characteristics of thrombospondin-1 and its cysteine-serine-valine-threonine-cysteine-glycine receptor in burn wounds

Thrombospondin-1 (TSP-1), an adhesive glycoprotein, plays an important role in platelet adhesion, inflammation, cell-to-cell interaction, and angiogenesis. TSP-1 is expressed by endothelial cells, fibroblasts, and macrophages. TSP-1's unique cysteine-serine-valine-threonine-cysteine- glycine (CSVTCG) specific receptor plays an important role in the binding and modulation of cellular adhesion and invasion. This article histologically and quantitatively evaluates TSP-1 and its CSVTCG receptor in adult burn wounds over time. Tissue was obtained from burn wounds on several days and samples that were 5 μm thick were placed on slides. Expression of TSP-1 and its CSVTCG receptor were evaluated immunohistochemically and quantitated by computer image analysis in units of absorbance. Immunoglobin G (IgG) (negative) controls were performed and subtracted from the TSP-1 sample to eliminate background absorbance readings. Serum (negative) control was used for the CSVTCG receptor. Platelet concentrates were used as the positive control. A quantitative examination of the results yielded the following information, expressed as absorbance ± standard error of the mean: TSP-1: day 1, 62.0 ± 10.13; day 3, 76.2 ± 6.90; day 5, 36.0 ± 3.96; day 7, 60.4 ± 5.67; and day 9, 29.5 ± 2.91. TSP-1 displays an early peak, followed by a steep decrease over the time period studied. The readings for the CSVTCG receptor are as follows: day 1, 33.8 ± 1.87; day 3, 34.5 ± 5.39; day 7, 39.1 ± 1.93; day 21, 39.1 ± 1.93; day 28, 34.8 ± 3.67. In contrast, the CVSTCG receptor continues to be present in the wound over time. Histologic findings are reported, and photographs and a histopathologic analysis are included. The information presented in this article leads to the conclusion that temporal and histologic differences exist in the localization and expression of TSP-1 and its CSVTCG receptor. TSP-1 is up-regulated in injured tissues immediately after the injury; it is rapidly down-regulated as the tissue heals. In contrast, the levels of the CSVTCG receptor remain relatively constant during the healing process. These data are consistent with TSP-1's known role in cell-to-cell interaction, including the modulation of the growth factor and protease activity.