CRYSTAL INTERACTIONS IN RENAL STONE DISEASE

描述(改编自申请者摘要)：这项资助的重点是 最关键但也是最不为人所知的机械论事件之一 尿石症是指尿路上皮细胞附着在尿液晶体上。 肾乳头状尖端是尿路结石的成熟部位 成长。石头研究文献支持组织之间的关系 损伤和结石病。他们对晶体在体内附着的研究 髓集合管细胞(IMCD)已经证明钙 一水草酸(COM)、羟基磷灰石(HA)和尿酸(UA)晶体 贴附在IMCD细胞培养物上的结构特定、可饱和和 可抑制的方式。水晶附着物似乎是基于特定的 石材表面分子阵列间的原子相互作用 晶体和IMCD表面富脂微区的表面 细胞。他们假设肾上皮细胞只与肾脏结合 如果外质膜存在特定的扰动，则为结石晶体 小叶磷脂成分和/或结构导致的形成 磷脂结构域在结构上与 晶体表面的分子阵列。这样的变化可能与 肾上皮损伤。 具体目标一.他们提出将COM、钙的附着 二水草酸(COD)、透明质酸(HA)和尿酸(UA)晶体对IMCD细胞的作用 它们质膜中的磷脂组成和结构 细胞。他们还建议界定组成中的变化和 磷脂结构域的结构与晶体结合的关系 PS和PI磷脂浓缩后。 他们建议研究晶体与IMCD细胞的结合，如 I)IMCD电池先前暴露在离子条件下或附近的函数 结石形成患者的过饱和状态 显示反复发作的结晶尿，II)IMCD细胞暴露 到包覆有选择性脂质或尿蛋白大分子的晶体 被确定为潜在的石材生长抑制或促进剂，以及iii) IMCD细胞在一种石晶型和第二种石晶型中的暴露 暴露第二种晶体类型以进行脂结构域成分或 结构微扰作为更有效的晶体附着的底物。 他们提出用结晶学的方法来模拟分子 所有五种晶体表面的结构以及晶体的结构 磷脂头基既是单一的也是混合的组装 磷脂结构。他们还建议从外延的角度分析 空间基础以及特定的分子成键与 将支持各种石头晶体之间的远程相互作用 IMCD细胞外叶富脂区的分子结构 质膜。

DESCRIPTION (Adapted from the Applicant's Abstract): This grant focuses on one of the most critical yet most poorly understood mechanistic events in urolithiasis, the attachment of urinary crystals by the epithelium of the kidney papillary tip which then serves as maturation sites for urinary stone growth. Stone research literature supports a relationship between tissue injury and stone disease. Their studies on crystal attachment to inner medullary collecting duct cells (IMCD) have demonstrated that calcium oxalate monohydrate (COM), hydroxyapatite (HA), and uric acid (UA) crystals attach to IMCD cells cultures in a structurally specific, saturable and inhibitable manner. Crystal attachment appears to be based on specific atomic interactions between molecular arrays on the surfaces of stone crystals and on the surfaces of lipid rich domains on the surfaces of IMCD cells. They hypothesize that renal epithelial cells will only bind kidney stone crystals if there is a specific perturbation in outer plasma membrane leaflet phospholipid composition and/or structure resulting in the formation of phospholipid domains which are structurally complementary to the molecular arrays on crystal surfaces. Such changes might be associated with renal epithelial injury. Specific Aim I. They propose to correlate the attachment of COM, calcium oxalate dihydrate (COD), HA, and UA crystals to IMCD cells with specific phospholipid composition and structure in the plasma membrane of these cells. They also propose to define the changes in the composition and structure of the phospholipid domains as a function of crystal attachment following PS and PI phospholipid enrichment. Specific Aim II. They propose to study crystal attachment to IMCD cells as a function of I) prior exposure of IMCD cells to ionic conditions at or near supersaturation conditions as would be expected in stone forming patients demonstrating recurrent episodes of crystalluria, ii) exposure of IMCD cells to crystals coated with selective lipids or urinary protein macromolecules identified as potential stone growth inhibitors or promoters, and iii) exposure of IMCD cells to one stone crystal type followed by a second exposure of a second crystal type to assay for lipid domain composition or structure perturbations as primers for more effective crystal attachment. Specific Aim III. They propose to crystallographically model the molecular structures on the surfaces of all five crystals as well as the structures of an assembly of phospholipid headgroups both as single as well as admixed phospholipid structures. They also propose to epitaxially analyze the dimensional basis as well as the specific molecular bonding matches that would support long range interactions between the various stone crystals and molecular structure in lipid-rich domains in the outer leaflet of IMCD cell plasma membranes.