C4orf7在牙周组织矿化动态平衡中的调控作用

Periodontal ligament is located in the root surface cementum and alveolar bone between the connective soft tissue, with the support, nutrition, sensory and functional form.It is one of the most active organizations in human body, which the rate of metabolism is much higher than gingiva, bone and skin. Periodontal ligament consist of the extracellular matrix and connective tissue cells, as well as blood vessels, lymphatic vessels and nerves constitute. The extracellular matrix contains mainly the molecules of collagen, glycoproteins and proteoglycans. The interaction between these components and control mechanisms make periodontal ligament in a state of dynamic equilibrium.Periodontal ligament in the body can maintain structural stability and good functional status, due to the regulation mechanisms of the sophisticated system of periodontal ligament cells and active signaling protein molecules. The mechanism, periodontal ligament in the course of life has always been to maintain the normal width and no mineralization of the physiological state and Maintain the dynamic equilibrium with around mineralization,is still not very clear and is the focus of many scholars to explore.C4orf7 is a new secreted protein found in the human teeth the new secreted protein, and the first reported of the periodontal ligament-specific markers. Studies have shown that it is only expressed in the periodontal ligament, and not in the enamel, dentin, pulp, alveolar bone and gingival of expression. As we all know, the specific tissues or organs to a large extent depends on the specificity of gene expression.Therefore, we predict that c4orf7 gene as the unique genes expression in periodontal ligament, has an important role in the formation and regeneration of the periodontal ligament.

牙周韧带是正畸牙移动中牙周骨组织改建的主要执行者。C4orf7 是首次在人类牙齿组织中发现的新基因，仅在牙的牙龈结合上皮和牙周韧带中表达，但是其生物学功能仍然未知。根据生物信息学比对，我们推断C4orf7 能够调控牙周韧带细胞的定向分化，是维持牙周组织中结缔组织（牙龈和牙周韧带）与矿化组织（牙骨质和牙槽骨）之间矿化动态平衡的关键调控因子。本课题组从细胞分化和信号转导的角度，研究C4orf7 对牙周韧带细胞功能的影响，探讨其与牙周组织中其他蛋白的相互作用并寻找其下游靶基因，明确其在正畸牙移动中的表达差异，以揭示其在C4orf7 在牙周组织中的独特功能，为进一步深入研究正畸牙移动的生物学机制奠定基础。

牙周炎是发生于牙周组织的感染性疾病，其特点为牙周支持组织的破坏，最终可导致牙齿的丢失。再生丢失的牙周组织是牙周炎的最终治疗目标。传统的治疗方法包括引导组织再生术等，但这些方法对于牙周组织再生的作用是有限的。随着组织工程与再生医学的发展，基于细胞与基因的再生方法为牙周炎的治疗提供了另一种可能性。. 牙周韧带定位于牙槽窝，作为一种血管化，富含细胞的软组织连接牙骨质与牙槽骨；大量研究表明，牙周韧带包含异质性细胞群体，在适当的培养条件下，牙周韧带细胞可分化为不同的细胞类型，包括成骨细胞，成牙骨质细胞，成软骨细胞，成脂细胞及神经细胞等；因此，牙周韧带细胞可作为再生牙周组织的候选细胞。. 在生理条件下，牙周骨组织处于一种持续不断的重塑状态。这一过程涉及不同类型始祖细胞间的复杂的相互作用；牙周韧带细胞向某一方向的特异性分化对于再生缺陷的牙周组织是至关重要的。. C4orf7是由85个氨基酸组成的小的分泌性肽，已有的体外研究报道，C4orf7过表达可维持牙周韧带细胞的成纤维表型，然而抑制其成骨分化。虽然这些研究已经阐明了C4orf7在牙周膜细胞成骨分化中的作用，但C4orf7在决定具多向分化潜能的牙周膜细胞向某一方向特异性分化中的角色还有待于进一步探索。. 本研究首先检测了C4orf7在牙周组织及体外培养的牙周膜细胞内的表达情况，然后采用慢病毒载体技术在体外培养的牙周膜细胞内过表达C4orf7,通过CCK8，碱性磷酸酶活性检测，茜素红染色，油红O染色，qPCR, western-blot等技术检测C4orf7过表达对牙周膜细胞成骨/成脂/破骨分化平衡的影响。结果表明：C4orf7在牙周韧带组织内显著表达，且可表达于原代培养的牙周膜细胞，但随着培养过程的进行，C4orf7在牙周膜细胞内的表达逐渐消失。C4orf7过表达对体外培养的牙周膜细胞增殖无影响，但可抑制牙周膜细胞的成骨/成牙骨质分化，促进成脂/破骨分化。因此，我们推测C4orf7可能是牙周炎及其他骨组织破坏性疾病潜在的治疗靶点。