C1Q-INDUCED CA2+RESPONSES IN FIBROBLAST HETEROGENEITY

人牙龈成纤维细胞（HGF）在健康和 疾病我们的目标是了解细胞和分子机制 在伤口愈合过程中控制成纤维细胞增殖。为此目的 我们已经建立了一种体外模型，该模型由分离的，稳定的， 表型和代谢特征的正常和 具有独特的炎性补体受体的肉芽组织 C1q。C1 q由两个重要区域组成：胶原样结构域和 球状域HGF可分为cC 1 qR亚型， 主要表达C1 q胶原蛋白样结构域受体的牙龈，和 主要表达C1 q受体的肉芽组织gC 1 qR亚型 球状域体内C1 q选择性地在损伤部位积累。 在体外C1 q抑制60 - 80%的HGF增殖，提示C1 q是一种抑制HGF增殖的基因。 这种蛋白质作为生长因子调节剂的重要作用 活动仅C1 q抑制gC 1 qR细胞的生长反应 在细胞周期的G1期;相反， cC 1 qR细胞的生长不依赖于细胞周期。不同的亚型 暴露于C1 q后胞质Ca 2+浓度的模式。我们 假设细胞内Ca 2+反应的差异诱导 通过C1 q的球状结构域与胶原样结构域结合， 成纤维细胞受体是不同生长因子反应的基础， 亚型，这种机制可能是重要的转变， 口腔组织细胞数量和代谢活性的变化 在愈合过程中。以下目的验证细胞内信号如何 由C1 q激活的细胞因子可能调节细胞的生长因子反应， 正常组织和肉芽组织。对于C1 q激活的每种亚型，Aim I定量第二信使cAMP和肌醇磷酸的水平 周转，调动和调节Ca 2+通量从外部和 内部来源，并评估蛋白激酶A和C的活化。目的 II决定了这些第二信使在抑制 C1 q对细胞生长的影响及PDGF受体的调节 C1 q的表达和功能。目的III表征了 静息和生长因子中C1 q诱导的Ca 2+内流/外流 激活亚型，决定激活特定的钙离子通道， 膜的亚型和激活特定的细胞内钙库。 结果将阐明成纤维细胞相互作用的意义 损伤部位有补体c1 q的亚型，亚型间的关系 在伤口愈合中相互作用，并可能部分解释了 健康和患病牙周组织的细胞群。这些研究 可能会导致一种新的方法或辅助疗法， 促进组织再生的因素，通过设计方法， 或在选择的亚型中下调这些生长要素- 受C1 q活性影响的因子信号级联 出现在治疗部位。

Human gingival fibroblast (HGF) function differently in health and disease. Our goal is to understand the cellular and molecular mechanisms that control fibroblast proliferation in wound healing. For this purpose we have established an in vitro model consisting of isolated, stable, phenotypically and metabolically characterized HGF subtypes of normal and granulation tissues with unique receptors for inflammatory complement C1q. C1q consists of two important regions: a collagen-like domain and a globular domain. HGF may be divided into subtype cC1qR of healthy gingiva expressing mainly receptors for C1q collagen-like domain, and subtype gC1qR of granulation tissue expressing mainly receptors for C1q globular domain. In vivo C1q selectively accumulates at sites of injury. In vitro C1q inhibits 60 to 80 % proliferation of HGF, suggesting an important role for this protein as a regulator of growth factors activities. The growth response of gC1qR cells is inhibited by C1q only during the G1 phase of the cell cycle; in contrast C1q inhibition of growth of cC1qR cells is cell cycle-independent. Subtypes differ in the pattern of cytosolic Ca2+ concentration following exposure to C1q. We hypothesize that the differences in intracellular Ca2+ response induced by the binding of globular versus collagen-like domain of C1q to specific fibroblast receptors underlie the different growth-factor response of subtypes, and that this mechanism may be important in the shifts of cellular populations and changes of metabolic activities of oral tissues during healing. The following aims verify how intracellular signals activated by C1q may regulate the growth-factor response of cells of normal and granulation tissues. For each subtype activated by C1q, Aim I quantifies levels of second messengers cAMP and inositol-phosphate turnover that mobilize and regulate Ca2+ flux from both external and internal sources, and assesses activation of protein kinases A and C. Aim II determines the role of these second messengers in the inhibitory effects of C1q on cell growth, and the regulation of PDGF receptor expression and function by C1q. Aim Ill characterizes the kinetics of C1q-induced Ca2+ influx/efflux in both resting and growth factor activated subtypes, determines activation of specific Ca2+channels on membrane of subtypes and activation of specific intracellular Ca2+stores. Results will elucidate significance of interactions of fibroblast subtypes with complement c1q at injured sites, relationship of subtypes to one another in wound healing, and may in part explain the shifts in cellular populations of healthy and diseased periodontium. These studies may lead to a new approach or adjunct to therapies that use growth factors to enhance tissue regeneration, by designing methodology that up- or down-regulates in the subtype of choice those elements of growth- factor signaling cascade that are affected by the activities of C1q present at sites of treatment.