Time-dependent pericellular expression of collagen type IV, laminin, and heparan sulfate proteoglycan in myofibroblasts

Human skin wounds (n = 62) with a wound age between 5 h and 6 weeks were investigated. The appearance of cell-associated pericellular basement membrane components collagen type IV, laminin and heparan sulfate proteoglycan (HSPG) in myofibroblasts was evaluated by immunohistochemistry. Laminin and HSPG were first detectable around myofibroblasts approximately 1.5 days after wounding. Collagen type IV did not appear before the 4th day after wound infliction. In wounds more than 7 days old, 94% of the cases showed fibroblastic cells positively staining for laminin, 70% of the wounds contained fibroblastic cells positive for HSPG and in 63% a positive reaction for collagen type IV was obtained around these cells. The numbers of the cases as well as of the cells positively stained for laminin exceeded the corresponding values for HSPG and especially for collagen type IV. The pericellular appearance of laminin or HSPG around myofibroblasts, therefore, indicates a wound age of at least approximately 1.5 days. The pericellular localization of collagen type IV indicates a survival time of approximately 4 days or more. Since these proteins are still detectable in the pericellular region of myofibroblasts in skin wounds with advanced wound age (6 weeks) further information for the time-estimation of older human skin lesions cannot be obtained. A semiquantitative analysis revealed no significant correlation between the number of positively stained cells and the wound age, rendering this parameter unsuitable for a practicable time-estimation of human wounds.