Objective: To investigate the expression and significance of peroxisome proliferator activated receptor γ(PPAR-γ) in human keloid.
Methods: Twenty-three keloid samples were harvested from the patients undergoing keloid and auto-skin grafting operation as the experimental group (keloid group), and the residual normal skin after auto-skin grafting operation was collected as the control group. The expression of PPAR-γ protein was examined by immunohistochemistry staining in both keloid and normal skin. Referring to Shimizu immunohistochemical standard, the result was graded; the positive rate of samples and the rate of positive cells were calculated.
Results: Immunohistochemistry staining showed that PPAR-γ protein was expressed in both keloid and normal skin. In keloid, it located in the pricle cell layer, and granular layer of epidermis, and the dermal vessel; the degree of dyeing was very light. However, in normal skin, it located in the base layer of epidermis, dermal vessel walls, sweat glands and sebaceous glands; the dyeing degree was deeper. Immunohistochemical staining score in the keloid group (2.65±0.78) was significantly lower than that in the control group (3.65±1.19) (t=5.030, P=0.000). The positive rate of samples in the keloid group (52.17%, 12/23) was significantly lower than that in the control group (82.61%, 19/23) (χ2=4.847, P=0.028). The rate of positive cells was 46.04%±8.61% in the keloid group, which was significantly lower than that in the control group (59.39%±11.26%) (t=5.974, P=0.000).
Conclusions: Compared with normal skin, the expression of PPAR-γ protein in keloid is down-regulated in in human keloid, indicating that PPAR-γ may be related to the formation of keloid.
目的: 探讨过氧化物酶体增殖物激活受体γ（peroxisome proliferator activated receptor γ,PPAR-γ）在瘢痕疙瘩组织中的表达及其意义。.
方法: 取23例患者自愿捐赠的瘢痕疙瘩标本进行观察，以同一患者手术取皮修剪后的剩余正常皮片作为正常对照。将标本行免疫组织化学染色，观察PPAR-γ蛋白的表达，参照Shimizu免疫组织化学评分标准进行评分，计算标本阳性率以及阳性细胞率。.
结果: 免疫组织化学染色示，PPAR-γ蛋白在瘢痕疙瘩和正常皮肤中均有表达。在瘢痕疙瘩中，其位于表皮的棘细胞层、颗粒层以及真皮血管，染色较浅；在正常皮肤中，位于表皮的基底层以及真皮血管壁、汗腺、皮脂腺，染色较深。瘢痕疙瘩组免疫组织化学染色评分为（2.65±0.78）分，低于正常对照组的（3.65±1.19）分；标本阳性率为52.17%（12/23），显著低于正常对照组的82.61%（19/23）；阳性细胞率为46.04%±8.61%，显著低于正常对照组的59.39%±11.26%。以上指标组间比较，差异均有统计学意义（t=5.030，P=0.000；χ2=4.847，P=0.028；t=5.974，P=0.000）。.
结论: 与正常皮肤相比，PPAR-γ在瘢痕疙瘩中呈下调表达状态，提示其可能与瘢痕疙瘩的形成有关。.
Keywords: Immunohistochemistry; Keloid; Peroxisome proliferator activated receptor γ.