探讨胰岛素样生长因子结合蛋白相关蛋白质1(IGFBPrP1)对SD大鼠及比格犬肺组织的影响及意义。

(1)健康雄性SD大鼠60只随机分为3组，A组(n＝10)：尾静脉注射生理盐水；B组(n＝25)：尾静脉注射腺病毒包装的增强型绿色荧光蛋白(Ad-EGFP)；C组(n＝25)：尾静脉注射腺病毒包装的IGFBPrP1(Ad-IGFBPrP1)。分别于注射后1、2、4、6、9周末留取肺组织。(2)健康雄性比格犬18只随机分为3组，每组6只。D组：正常饲养。E组：硫代乙酰胺(TAA)皮下注射12 mg/kg，2次/周。F组：TAA皮下注射12 mg/kg，2次/周，5周起同时注射IGFBPrP1抗体，5 μg/kg，1次/周。12周末留取各犬肺组织。前期实验已证实采用以上C组及E组相同处理方法可成功诱导SD大鼠及比格犬肝纤维化。行HE染色和Siris Red染色观察SD大鼠及比格犬肺组织病理形态改变及胶原纤维形成情况；免疫组织化学染色检测SD大鼠肺组织IGFBPrP1、转化生长因子β1(TGFβ1)、纤维连接蛋白(FN)、白细胞介素1β(IL-1β)以及比格犬肺组织IGFBPrP1的分布及表达。

(1)SD大鼠：与A、B组大鼠正常肺组织相比，C组肺组织转染早期出现炎性损伤，随转染时间延长病变加重，转染9周胶原纤维明显增多发生纤维化样病变；IGFBPrP1于C组2周达高峰(1.5±0.03)，IL-1β于C组4周达高峰(1.94±0.03)，后均逐渐下降；TGFβ1蛋白表达从C组1周时开始明显增多，呈转染时间依赖性升高，9周达高峰(2.38±0.01)；FN表达在C组9周(1.23±0.05)时明显增高。(2)比格犬：与D组正常肺组织相比，E组肺组织病变严重，胶原纤维含量增多，F组病变程度较E组显著减轻；IGFBPrP1在E组(1.39±0.20)、F组(1.05±0.16)的表达较D组(0.50±0.14)明显增多，F组IGFBPrP1蛋白表达较E组减少，差异均有统计学意义(P<0.01)。

IGFBPrP1对SD大鼠肺组织有炎性损伤甚至促纤维化作用，也可引起比格犬肺组织损伤，可能是一种无组织器官特异性的致病因子。

To investigate the effect and significance of insulin-like growth factor-binding protein related protein 1(IGFBPrP1)on lung tissue in SD rats and beagles.

①Sixty healthy male SD rats were randomly divided into A group(n=10)、B group(n=25)and C group(n=25), and were respectively injected with the same doses of saline, Ad-EGFP and Ad-IGFBPrP1 via the caudal vein.Lung tissues were obtained for analysis at week 1, 2, 4, 6 and 9.②Eighteen healthy male beagles were randomly assigned to three groups of 6 each.Beagles in D group had a free access to food and water.Beagles in E group were given subcutaneous injection of thioacetamide(TAA)(12 mg/kg, twice per week). Beagles in F group were given subcutaneous injection of TAA(12 mg/kg, twice per week), and IGFBPrP1-Ab(5 μg/kg, once per week)were injected into portal vein from week 5.Lung tissues of all beagles were obtained for analysis at week 12.The same methods of group C and E could cause hepatic fibrosis to SD rats and beagles successfully.HE staining and Siris Red staining were observed to investigate the pathomorphological changes and deposition of collagen fibers in lung of SD rats and beagles.The expressions of IGFBPrP1, transforming growth factorβ1(TGFβ1), fibronectin(FN)and interleukin1(IL-1β)of lung tissues in SD rats and IGFBPrP1 in beagles were detected by immunohistochemical staining.

①SD rats: Comparing with A and B group, there appeared inflammatory injury after the transfection of Ad-IGFBPrP1 and the degree of inflammation was gradually advanced with time, and lung fibrosis and increase of collagen fibers were observed at 9 weeks in C group.The expression of IGFBPrP1 protein in C group increased and peaked(1.5±0.03)at 2 weeks after transfection, then gradually decreased.The level of IL-1βup-regulated and peaked(1.94±0.03)at 4 weeks after transfection and later gradually down-regulated.The level of TGFβ1 increased from 1 week, and peaked(2.38±0.01)at 9 weeks.The expression pattern of FN was similar to TGFβ1, and it peaked at 9 week s(1.23±0.05). ②Beagles: Comparing with D group, E group showed pathomorphological changes and deposition of collagen fibers.Comparing with E group, the degree of pathomorphological changes and the content of collagen fiber decreased in F group.The expression of IGFBPrP1 protein in E group(1.39±0.20)and F group(1.05±0.16)increased comparing with D group(0.50±0.14), and that in F group was less than E group(P<0.01).

IGFBPrP1 contributes to the inflammatory injury and fibrosis of the lung tissue in SD rats, and it can also cause varying degrees of damages to the lung tissue in beagles, which may not be a tissue-specific pathogenic factor.