Basement Membranes and Associated Protein Factors In Development and Disease

发育和疾病中的基底膜和相关蛋白质因子

• 批准号: 8553324
• 负责人: Yoshihiko Yamada
• 金额: $ 81.79万
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8553324
• 关键词: Active Sites; Adult; Affect; Afferent Neurons; Animal Model; Axon; Basement membrane; Behavior Disorders; Biological; Caliber; Cell Adhesion; Cell Surface Receptors; Cells; Cerebellum; Collaborations; Collagen Type IV; Corticospinal Tracts; Defect; Development; Disease; Embryo; Endothelial Cells; Epiblast; Epithelial; Extracellular Matrix; Extracellular Matrix Proteins; Family; Fiber; Genes; Glycoproteins; Goals; Hereditary Disease; Hindlimb; Integral Membrane Protein; Knockout Mice; Laminin; Membrane; Membrane Proteins; Meninges; Mesenchymal; Molecular Conformation; Morphogenesis; Motor; Multiple Sclerosis; Mus; Muscle Cells; Mutation; Myelin; NID gene; Neuraxis; Neurites; Neurons; Nidogen; Oligodendroglia; Organ; Patients; Phenotype; Play; Process; Proteins; Purkinje Cells; Role; Sensory; Spinal Cord; Spinal Cord Tract; Structure; Structure-Activity Relationship; Tissues; Transgenes; Transgenic Mice; Transgenic Organisms; Tremor; Tumor Cell Invasion; Wild Type Mouse; dorsal column; dysmyelination; granule cell; implantation; in vivo; laminin-1; membrane assembly; migration; mouse model; myelination; perlecan; scaffold; tissue repair

Basement membranes are thin extracellular matrices that separate epithelial and mesenchymal cells, and surround cells such as endothelial, muscle, and neural cells. Basement membranes are the first extracellular matrix to appear in development and are critical for organ development and tissue repair. They not only provide the scaffold for cells and cell layers, but they also play an essential role in morphogenesis that affects cell adhesion, migration, proliferation, and differentiation. Basement membranes consist of collagen IV, laminin, perlecan, nidogen/entactin, and other molecules, and they interact with one another to form supramolecular structures. Laminins are a family of large multidomain glycoproteins that are usually specific to basement membranes. Laminins perform a variety of biological activities, including promotion of cell adhesion, migration, differentiation, tumor cell invasion, and interactions with matrix molecules and cell surface receptors. Laminin-1 (also called laminin-111) is a heterotrimeric extracellular matrix protein composed of α1, β1, and γ1 chains and is crucial for early basement membrane assembly, as well as embryonic implantation and development. Laminin-1 promotes neurite outgrowth in various neuronal cells, and several active sites in the α1 and γ1 chains for neurite outgrowth have been identified. Mouse embryos that are deficient in Lama1 lack Reichert's membrane and die by embryonic day 7. In the central nervous system, however, the role of Lama1 is unknown. To study the in vivo role of Lama1 in the CNS, we generated conditional Lama1 knockout (Lama1CKO) mice in the epiblast lineage using Sox2-Cre mice in collaboration with Dr. Eri Arikawa-Hirasawa. These Lama1CKO mice survived, but displayed behavioral disorders and impaired formation of the cerebellum. Deficiency of Lama1 in the pial basement membrane of the meninges resulted in defects in the conformation of the meninges. During cerebellar development, Lama1 deficiency also caused a decrease in the proliferation and migration of granule cell precursors, disorganization of Bergmann glial fibers and endfeet, and a transient reduction in the activity of Akt. A marked reduction in the number of dendritic processes in Purkinje cells was observed in Lama1CKO mice. Together, these results indicate that Lama1 is required for cerebellar development and function. During the creation of transgenic mice to study the role of perlecan, a basement membrane component, we found that one of the transgenic lines developed tremor in the hindlimbs. We designated this mouse model as furue (fru/fru). We subsequently identified that the furue mutation was caused by a transgene insertion into the teneurin-4 (Ten-4/Odz4) gene, which encoded a transmembrane protein of unknown function. Ten-4 was strongly expressed in the spinal cord of wild-type mice and was induced during normal oligodendrocyte differentiation. In contrast, the furue mice showed no expression of Ten-4. In the spinal cord of the furue mice, myelination of small diameter axons was dramatically reduced and differentiation of oligodendrocytes in the CNS was inhibited. The tremor phenotype in fur/fur mice was predominantly observed in the hindlimbs. The dorsal column of the fur/fur spinal cord showed severe defects in myelin formation in the corticospinal tract and fasciculus gracilis. The corticospinal tract is one of the major motor tracts and consists of many small diameter axons. The fasciculus gracilis is the region from which the small diameter axons of the lower body's sensory neurons ascend. Therefore, defects in myelination of small diameter axons in the corticospinal tract and the fasciculus gracilis are likely the cause of the hindlimb-dominant tremors in the fur/fur mice. In patients with multiple sclerosis, a dysmyelinating disease, small diameter axons are selectively damaged in the corticospinal and sensory tracts of the spinal cord. Ten-4 may therefore play an important role in multiple sclerosis.

基底膜是薄的细胞外基质，其将上皮细胞和间充质细胞分开，并包围细胞如内皮细胞、肌肉细胞和神经细胞。 基底膜是发育过程中出现的第一种细胞外基质，对器官发育和组织修复至关重要。它们不仅为细胞和细胞层提供支架，而且在影响细胞粘附、迁移、增殖和分化的形态发生中发挥重要作用。基底膜由IV型胶原、层粘连蛋白、串珠蛋白聚糖、巢蛋白/巢蛋白和其他分子组成，并且它们彼此相互作用以形成超分子结构。 层粘连蛋白是一个大的多结构域糖蛋白家族，通常特异于基底膜。层粘连蛋白具有多种生物学活性，包括促进细胞粘附、迁移、分化、肿瘤细胞侵袭以及与基质分子和细胞表面受体的相互作用。层粘连蛋白-1（也称为层粘连蛋白-111）是由1、1和1链组成的异源三聚体细胞外基质蛋白，并且对于早期基底膜组装以及胚胎植入和发育至关重要。层粘连蛋白-1促进各种神经元细胞中的神经突生长，并且已经鉴定了神经突生长的1和1链中的几个活性位点。缺乏Lama 1的小鼠胚胎缺乏Reichert膜，并在胚胎第7天死亡。然而，在中枢神经系统中，Lama 1的作用尚不清楚。为了研究Lama 1在CNS中的体内作用，我们与Eri Arikawa-Hirasawa博士合作，使用Sox 2-Cre小鼠在上胚层谱系中产生了条件性Lama 1敲除（Lama 1CKO）小鼠。这些Lama 1CKO小鼠存活下来，但表现出行为障碍和小脑形成受损。脑膜软脑膜基底膜中Lama 1的缺乏导致脑膜构象的缺陷。在小脑发育过程中，Lama 1缺陷还导致颗粒细胞前体的增殖和迁移减少，Bergmann胶质纤维和终足的解体，以及Akt活性的短暂降低。在Lama 1CKO小鼠中观察到浦肯野细胞中树突状突起的数量显著减少。总之，这些结果表明Lama 1是小脑发育和功能所必需的。 在创建转基因小鼠以研究基底膜成分串珠素的作用期间，我们发现其中一个转基因品系的后肢出现震颤。我们将该小鼠模型命名为furue（fru/fru）。我们随后确定，furue突变是由转基因插入teneurin-4（Ten-4/Odz 4）基因引起的，该基因编码一种功能未知的跨膜蛋白。Ten-4在野生型小鼠的脊髓中强烈表达，并在正常少突胶质细胞分化过程中被诱导。相比之下，furue小鼠没有显示Ten-4的表达。在furue小鼠的脊髓中，小直径轴突的髓鞘形成显著减少，CNS中少突胶质细胞的分化受到抑制。毛皮/毛皮小鼠的震颤表型主要在后肢中观察到。毛皮/毛皮脊髓的背柱显示皮质脊髓束和薄束中髓鞘形成的严重缺陷。皮质脊髓束是主要的运动束之一，由许多小直径的轴突组成。薄束是下体感觉神经元的小直径轴突向上延伸的区域。因此，皮质脊髓束和薄束中小直径轴突的髓鞘形成缺陷可能是毛皮/毛皮小鼠后肢优势震颤的原因。在患有多发性硬化症（一种髓鞘形成障碍疾病）的患者中，脊髓的皮质脊髓束和感觉束中的小直径轴突被选择性地损伤。因此，Ten-4可能在多发性硬化症中发挥重要作用。