CD90 Expression And Biological Characteristics Of Fibroblasts From Abnormal Scars And Normal Skin

OBJECTIVE : To investigate the differences of CD90 expression and biological characteristics of fibroblasts from abnormal scars and normal skin. CD90 expression of fibroblasts in abnormal scars and normal skin was undertaken by immunohistochemistry. Primary culture was applied to establish abnormal scar-derived fibroblasts model and the expression of CD90 and its correlation with the proliferation, synthesis and contraction of fibroblasts from abnormal scars and normal skin in vitro were investigated through immunocytochemistry and fluorescent quantitation with LSCM (laser scan confocal microscopy).METHODS:1. The 16 abnormal scar tissues and matched normal skin were divided into keloid group(K, n=4), hypertrophic scar group(HTS, n=12), normal skin-keloid group(n=4) and normal skin-hypertrophic scar group(n=12). Two Pathologists checked all the tissue sections with haematoxylin-eosin dyeing in order to support the clinical diagnosis. 2. CD90 expression of fibroblasts in abnormal scars and normal skin was compared by SABC immunohistochemistry techniques. 3. Fibroblasts were isolated from three more specific samples of every group by primary culture. The cell morphology and reproductive cycle of fibroblasts were observed to study their biological characteristics while we cultured four kinds of fibroblasts. 4. After natural purification and three passaging, we detected CD90 expression in fibroblasts grown on cover glass by SABC immuocytochemistry techniques. 5. CD90,α-SMA and ki-67 expression in every cell line were detected by double immunofluorescence labeling. The four protein expressions were compared in fibroblasts through calculating the fluorescent quantitation of CD90,α-SMA,Collagen-Ⅰand the percentage of ki-67+ cells. 6. The correlation of CD90 expression with that ofα-SMA, Collagen-Ⅰa nd Ki-67 was determined by means of statistical analysis. 7. The position of CD90 andα-SMA in fibroblasts was showed by double channels scanning of laser scan confocal microscopy.RESULTS:1.Immunohistochemistry showed that there was no CD90+ phenotypic fibroblasts in 4 cases of keloid and the normal skin-keloid surrounded,while a few of hypertrophic fibroblasts in 7 pieces of tissues out of the 12 samples which expressed CD90 in hypertrophic scars,and some smaller CD90+ cells were found in the normal skin around the scars. 2. We successfully established the abnormal scar-derived fibroblasts model with stable biological characteristics by primary culture and supplied the in vitro model for the further investigation of abnormal scars. 3. Immunocytochemistry showed CD90 expressed in all kinds of fibroblasts in vitro. 4. Double immunofluorescence labling combining with Fluorescent quantitation manifested that CD90 expression in hypertrophic scar-derived fibroblasts was significantly more than that in normal skin-derived fibroblasts (P<0.05). There was no difference in CD90 expression between the fibroblasts derived from keloid and normal skin (P>0.05). 5. Statistical analysis could not verify the correlation of CD90 expression withα-SMA,Ki-67,Collagen-Ⅰ. 6. Double channels scaning of LSCM showed that CD90 andα-SMA expression were co-location and had the coherent tendency in single fibroblast.CONCLUSIONS:1.Fibroblasts in hypertrophic scars that express CD90 might be some specifically phenotypic fibroblasts resulted in scar formation. 2. Using primary culture could establish abnormal scar-derived fibroblasts model. 3. There are some fibroblasts derived from hypertrophic scars significantly expressing CD90 in vitro. 4. CD90 expression andα-SMA are co-location and coherent in single fibroblast and they might have some synergistic relationships.