Continuous Treatment with Oxalate Changes Renal Physiology and Morphology (DK0750

草酸盐连续治疗改变肾脏生理学和形态学 (DK0750

• 批准号: 7147259
• 负责人: SUSAN RUTH MARENGO
• 金额: $ 23.18万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7147259
• 关键词: crystallization; cytotoxicity; disease /disorder model; disease /disorder proneness /risk; drug administration rate /duration; drug adverse effect; drug screening /evaluation; electrolyte balance; immunofluorescence technique; ion exchange chromatography; kidney function; laboratory rat; liver function; model design /development; morphology; myocardium disorder; nephrocalcinosis; northern blottings; oxalates; physiologic bone resorption; polymerase chain reaction; renal tubule; terminal nick end labeling; transmission electron microscopy; western blottings

DESCRIPTION (provided by applicant): The role that oxalate plays in calcium oxalate (CaOx) nephrocalcinosis and oxalate driven nephrolithiasis is not well understood. There is accruing evidence that in addition to crystal formation, oxalate promotes these conditions through its interactions with the renal epithelium, interstitium and vasculature. Differing susceptibilities to these effects may partially explain why individuals with similar risk factors have do not have similar clinical symptoms. This proposal will utilize two versions of the minipump model to study these interactions. The standard 14D protocol models moderate-to-severe hyperoxaluria in that it induces a greater than or equal to 3x increase in oxalate excretion and intratubular CaOx-nephrocalcinosis. The LongDose protocol will model the more common mild-to-moderate hyperoxaluria by inducing less than or equal to 1.5-2x increase in oxalate excretion over a 4wk period and the induction of mixed CaOx-/CaP- nephrocalcinosis. A novel aspect of this proposal is that ion chromatography and polarizing microscopy/ Yasue staining + morphometric analysis will be used to correlate oxalate's effects on specific segments of the nephron, interstitium or vasculature with intrarenal oxalate concentrations and crystal deposition. Dose response and time course studies will identify those changes which occur prior to crystal deposition and thus could be fostering nephrocalcinosis. In Specific Aim 1, the effects of 360 muM KOx/24hr for 14D on liver function, cardiomyopathy, and bone remodiling will be determined and the LongDose protocol will be developed. Specific Aim 2 will utilize RT-PCR, Northern & Western blotting and immunofluorescence to identify changes in the expression of segment specific, general distress, vasculature distress and stone disease makers during continuous, steady exposure to oxalate. Specific Aim 3 will utilize transmission electron microscopy and immunofluorescence to identify segments of the nephron and regions of the interstitium and vasculature that show morphological damage, apoptosis or proliferation during continuous, steady exposure to oxalate. Relevance to Public Health: This proposal investigates oxalate's effects on specific regions of the kidney during the early phases of CaOx- nephrocalcinosis and oxalate driven stone disease using the rat minipump model. The objective is to identify those effects which promote these conditions. Future work will determine the mechanism of these effects with the goal of developing an effective preventative therapy.

描述（由申请人提供）：草酸盐在草酸钙（CaOx）肾钙质沉着症和草酸盐驱动的肾结石中所起的作用尚不清楚。越来越多的证据表明，除了晶体形成之外，草酸盐还通过与肾上皮、间质和脉管系统的相互作用促进这些病症。对这些影响的不同敏感性可能部分解释了为什么具有相似危险因素的个体没有相似的临床症状。该提案将利用两个版本的微型泵模型来研究这些相互作用。标准 14D 方案模拟中度至重度高草酸尿症，因为它会导致草酸盐排泄增加 3 倍以上以及肾小管内 CaOx 肾钙质沉着症。 LongDose 方案将通过在 4 周内诱导草酸盐排泄量增加小于或等于 1.5-2 倍以及诱导混合 CaOx-/CaP- 肾钙质沉着症来模拟更常见的轻度至中度高草酸尿症。该提案的一个新颖之处在于，离子色谱和偏光显微镜/安江染色+形态分析将用于将草酸盐对肾单位、间质或脉管系统特定部分的影响与肾内草酸盐浓度和晶体沉积相关联。剂量反应和时程研究将确定晶体沉积之前发生的那些变化，从而可能促进肾钙质沉着症。在具体目标 1 中，将确定 360 muM KOx/24 小时持续 14 天对肝功能、心肌病和骨重塑的影响，并开发长剂量方案。具体目标 2 将利用 RT-PCR、Northern 和 Western 印迹以及免疫荧光来识别在连续、稳定暴露于草酸盐期间节段特异性、一般性不适、脉管系统不适和结石病制造者的表达变化。具体目标 3 将利用透射电子显微镜和免疫荧光来识别在连续、稳定暴露于草酸盐期间表现出形态损伤、细胞凋亡或增殖的肾单位片段以及间质和脉管系统区域。与公共健康的相关性：该提案使用大鼠微型泵模型研究了草酸盐在 CaOx 肾钙质沉着症和草酸盐驱动的结石病的早期阶段对肾脏特定区域的影响。目的是确定促进这些情况的影响。未来的工作将确定这些影响的机制，目标是开发有效的预防疗法。