Procollagen C-Proteinase Enhancers: In vivo Roles

描述(由申请人提供)：前胶原C-蛋白水解酶(PCPs)裂解前胶原Mil的C-肽，产生形成ECM主要纤维成分的单体。两个PCP增强子蛋白(PCOLCE1和2)不是蛋白酶，但它们在体外以某种方式使PCP活性增加约10倍。PCOLCE1C端结构域可以抑制肿瘤细胞分泌的基质金属蛋白酶，并具有从软骨分离的抗血管生成活性。PCOLCE1也可能在生长控制中发挥作用，因为同源基因的破坏导致培养的成纤维细胞的非锚定生长。我们培育了PCOLCE1基因Pcolce为零等位基因的小鼠，以确定其在体内的作用。Pcolce-/-小鼠存活并具有生育能力，但在骨骼和软组织中存在严重的ECM扰动，因此确定PCOLCE1是骨强度和ECM完整性的决定因素。最近，我们成功地培育了PCOLCE2基因零等位基因Pcolce2的小鼠，并发现Pcolce2-/-小鼠既能存活又能生育。Pcolce2在软骨中的主要发育表达，以及Pcolce-/-小鼠的骨骼表型，表明Pcolce2在软骨内骨形成和关节炎的发病机制中发挥作用(S)。Pcolce和Pcolce2在心脏中的表达水平特别高，Pcolce2在眼睛中也有高水平的表达。我们建议对成年和胚胎Pcolce-/-和Pcolce2-/-小鼠及其衍生细胞进行充分的鉴定，以确定骨骼和软组织异常的分子基础和全部范围。Pcolce-/-和Pcolce2-/-小鼠的杂交产生Pcolce/Pcolce2双纯合子代，将去除由于Pcolce和Pcolce2之间可能的功能冗余而产生的任何残余活性。对Pcolce-/-、Pcolce2-/-和双零小鼠、胚胎和细胞的研究将有助于清楚地描述PCPE在哺乳动物发育、动态平衡和病理学中的作用。基于我们实验室最近关于PCOLCE1和BMP1样多氯联苯之间物理相互作用的证据，我们还提出了一些研究，这些研究有望改变我们对多氯联苯和多氯联苯功能的理解。

DESCRIPTION (provided by applicant): Procollagen C-proteinases (PCPs) cleave the C-propetides of procollagens Mil, to yield monomers that form the major fibrous components of ECM. The two PCP enhancer proteins (PCOLCE1 and 2) are not proteinases, yet they somehow enhance PCP activities approximately 10-fold in vitro. The PCOLCE1 C-terminal domain can inhibit matrix metalloproteinases (MMPs) secreted by tumor cells, and provides an anti-angiogenic activity isolated from cartilage. PCOLCE1 may also play a role in growth control, as disruption of the cognate gene results in anchorage-independent growth in cultured fibroblasts. We have generated mice with null alleles for the PCOLCE1 gene Pcolce, to ascertain its in vivo roles. Pcolce-/- mice are viable and fertile, but have profound ECM perturbations in bone and soft tissues, thus identifying PCOLCE1 as a determinant of bone strength and ECM integrity. More recently, we have succeeded in generating mice with null-alleles for the PCOLCE2 gene, Pcolce2, and have found Pcolce2-/- mice to be both viable and fertile. Predominant developmental expression of Pcolce2 in cartilage, plus the skeletal phenotype of Pcolce-/- mice, suggest role(s) for Pcolce2 in endochondral bone formation and in pathogenesis of arthridities. Both Pcolce and Pcolce2 are notable for particularly high expression levels in heart and Pcolce2 is also expressed at high levels in eye. We propose fully characterizing adult and embryo Pcolce-/- and Pcolce2-/- mice and derived cells, to determine the molecular bases and full extents of skeletal and soft tissue abnomalities. Crosses of Pcolce-/- and Pcolce2-/- mice to produce Pcolce/Pcolce2 doubly homozygous null progeny will remove any residual activity due to possible functional redundancy between Pcolce and Pcolce2. Studies of Pcolce-/-, Pcolce2-/- and doubly null mice, embryos and cells will enable clear delineation of PCPE roles in mammalian development, homeostasis and pathology. Based on recent evidience in our lab of physical interactions between PCOLCE1 and BMP1-like PCPs, we also propose studies that promise a paradigmatic shift in our understanding of how PCPs and PCOLCEs function.