CRYSTAL INTERACTIONS IN RENAL STONE DISEASE

描述（改编自申请人的摘要）：本补助金的重点是 这是人类历史上最关键但最不为人所知的机械事件之一， 尿石症，尿晶体附着在上皮细胞上， 肾乳头尖端，然后作为泌尿系结石的成熟部位 增长 结石研究文献支持组织 损伤和结石病。 他们对晶体附着在内部的研究 髓集合管细胞（IMCD）已经证明，钙 草酸一水合物（COM）、羟基磷灰石（HA）和尿酸（UA）晶体 附着在IMCD细胞培养物中， 以令人信服的方式。 晶体附着似乎是基于特定的 石头表面分子阵列之间的原子相互作用 晶体和IMCD表面上的脂质丰富的领域的表面上 细胞 他们假设肾上皮细胞只会结合肾脏 如果外质膜有特定的扰动， 小叶磷脂组合物和/或结构 磷脂结构域，其在结构上与 晶体表面的分子阵列。 这些变化可能与 肾上皮损伤 具体目标一。他们提出COM的附着与钙离子 草酸二水合物（COD），HA和UA晶体的IMCD细胞与特定的 磷脂组成和结构在质膜的这些 细胞 他们还提议界定组成的变化， 磷脂结构域的结构作为晶体附着的函数 在PS和PI磷脂富集之后。 具体目标二。 他们建议研究IMCD细胞的晶体附着， I）IMCD细胞先前暴露于等于或接近等于或接近等于 如结石形成患者中预期的过饱和状态 ii）暴露于IMCD细胞， 涂有选择性脂质或尿蛋白大分子的晶体 被鉴定为潜在的结石生长抑制剂或促进剂，和iii） IMCD细胞暴露于一种石晶体类型，然后是第二种 将第二种晶体类型暴露于脂质结构域组成的测定，或 结构扰动作为引物用于更有效的晶体附着。 具体目标三。 他们提出用晶体学方法模拟 所有五种晶体表面的结构以及 磷脂头基的组装，无论是单一的还是混合的， 磷脂结构 他们还建议外延分析 尺寸基础以及特定的分子键合匹配， 将支持各种石晶体之间的远距离相互作用， 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.