Expression and activity of collagenases in the digital laminae of horses with carbohydrate overload-induced acute laminitis.
Expression and activity of collagenases in the digital laminae of horses with carbohydrate overload-induced acute laminitis.
复制标题
患有碳水化合物超载引起的急性蹄叶炎的马的指趾板中胶原酶的表达和活性。
DOI：
10.1111/jvim.12252
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发表时间：
2014
影响因子：
2.6
通讯作者：
Black,SJ
中科院分区：
文献类型：
--
作者：
Wang,L;Pawlak,EA;Johnson,PJ;Belknap,JK;Alfandari,D;Black,SJ
背景基质金属蛋白酶（MMP）被认为降解了患有蹄叶炎的马的层状细胞外基质（ECM）的结构重要成分。（MMP-1，-13）和膜型MMP（MMP-14，-15，-16），以及它们的ECM底物的分布，在健康马和患有碳水化合物过载蹄叶炎的马的蹄叶中。动物二十五匹成年马。方法使用真实的时间定量测定蹄叶提取物中的基因和蛋白质表达。十二烷基硫酸钠聚丙烯酰胺凝胶电泳后进行聚合酶链反应和Western印迹。使用非固定冷冻切片的间接免疫荧光显微镜测定MMP-13和ECM组分的分布。ECM形态通过苏木精和伊红染色进行评估。ResultsOf研究的基因中，只有那些编码MMP-1和-13的基因在CHO诱导的蹄叶炎中上调; MMP-1在Obel等级（OG）1跛行，MMP-13在OG 3跛行。层MMP-1仅以52 kDa酶原存在。MMP-13以原酶（61 kDa）和加工酶（48 kDa）的形式存在。MMP-13定位于次级表皮层的基底上皮，其表达增加伴随着次级真皮层（SDL）中多个病灶的出现，这些病灶缺乏胶原蛋白I、纤连蛋白、软骨素和硫酸角质素糖胺聚糖以及伊红染色材料。通过降解ECM的成分，可能导致OG 3跛行SDL中出现的无ECM病变（间隙或撕裂）的形成。
BackgroundMatrix metalloproteinases (MMP) are hypothesized to degrade structurally important components of the laminar extracellular matrix (ECM) in horses with laminitis.ObjectiveTo compare levels of expression of stromelysin‐1 (MMP‐3), collagenases (MMP‐1, ‐13), and membrane type‐MMPs (MMP‐14, ‐15, ‐16), and the distribution of their ECM substrates, in laminae of healthy horses and horses with carbohydrate overload laminitis.AnimalsTwenty‐five adult horses.MethodsGene and protein expression were determined in extracts of laminae using real‐time quantitative polymerase chain reaction and Western blotting after sodium dodecylsulfate polyacrylamide gel electrophoresis. Distribution of MMP‐13 and ECM components was determined using indirect immunofluorescent microscopy of nonfixed frozen sections. ECM morphology was assessed by hematoxylin and eosin staining.ResultsOf the genes studied, only those encoding MMP‐1 and ‐13 were upregulated in CHO‐induced laminitis; MMP‐1 at Obel grade (OG)1 lameness and MMP‐13 at OG3 lameness. Laminar MMP‐1 was present as 52 kDa proenzyme only. MMP‐13 was present as pro‐ (61 kDa) and processed (48 kDa) enzyme. MMP‐13 localized to the basal epithelium of the secondary epidermal laminae and its increased expression were accompanied by the appearance in secondary dermal laminae (SDL) of multiple foci that were devoid of collagen I, fibronectin, chondroitin and keratan sulfate glycosaminoglycans, and eosin‐staining material.Conclusions and Clinical RelevanceMMP‐13 is upregulated in laminae of horses with CHO‐induced OG3 lameness and, by degrading components of the ECM, may contribute to the formation of ECM‐free lesions (gaps or tears) that appear in the SDL with OG3 lameness.