Project description:Kidney stone disease causes significant morbidity and increases health care utilization. In this dataset, we applied a single-nucleus assay to renal papila samples in order to charachterize the cellular and molecular niches in patients with calcium oxalate (CaOx) stone disease and healthy subjects. In addition to identifying cell types important in papillary physiology, we characterize collecting duct cell subtypes and an undifferentiated epithelial cell type that was more prevalent in stone patients. Despite the focal nature of mineral deposition in nephrolithiasis, we uncover a global injury signature characterized by immune activation, oxidative stress and extracellular matrix remodeling. We also identify the association of MMP7 and MMP9 expression with stone disease and mineral deposition, respectively. MMP7 and MMP9 are significantly increased in the urine of patients with CaOx stone disease, and their levels correlate with disease activity. Our results define the spatial molecular landscape and specific pathways contributing to stone-mediated injury in the human papilla and identify associated urinary biomarkers.
Project description:Comparison between renal papilla tissue with and without the presence of calcified Randall’s plaques, and between the papilla, medulla, and cortex regions from within a single recurrent stone forming kidney demonstrated that patterns of gene expression between the papilla, medulla, and cortex that distinguished these three regions from one another. Disease and function analysis of these gene sets demonstrated up-regulation of genes related to urinary/renal disorders, granulocyte response, vascular smooth muscle cell proliferation, dehydration, and renal calcification and down-regulation of genes related to carboxylic acid/ lipid/ fatty acid transport and urine osmolality.
Project description:Urinary tract-associated lymphoid structures (UTLASs), tertiary lymphoid tissues, are formed in renal pelvis (RP) of humans and mice with chronic kidney disease. We found that UTALS development was accelerated by urine leakage from RP lumen to the parenchyma following dysfunction of transitional epithelium covering UTLASs. Thus, UTALS-forming cells were stimulated by urine including urinary bio active substances.
Project description:Clinical and animal studies have demonstrated the increasing evidence of oxidative stress in kidney stone disease. Recent findings have shown that the interactions between calcium oxalate (CaOx) crystals and renal tubular cells can promote many cellular events such as cell proliferation, cell death, cellular injury, mitochondrial dysfunction and inflammatory cascade. All of these cellular events are associated with oxidative stress and overproduction of free radicals and reactive oxygen species (ROS) such as superoxide and hydrogen peroxide in renal tubular cells. However, almost all of these references have shown that oxidative stress occurs after the causative crystals have been deposited in the kidney or exposed to renal tubular cells, whereas its primary role as the etiology remained unclear. In this study, we examined effects of oxidative modifications of urinary proteins on CaOx stone formation processes. Urinary proteins were modified by performic oxidation and the presence of oxidatively modified urinary proteins was verified, quantified and characterized by Oxyblot assay and tandem mass spectrometry (nanoLC-ESI-LTQ-Orbitrap-MS/MS). Subsequently, activities of oxidatively modified urinary proteins on CaOx stone formation processes were examined.
Project description:<p>Genetic and environmental factors play an important role in the etiology of nephrolithiasis. This project will build on and extend our previous efforts (examining environmental risk factors for stone formation) by allowing us to study the risk of stone formation associated with specific genes and gene-environment interactions. We will take advantage of previously collected data in three large cohort studies: Nurses' Health Study I (n=121,000 women), Nurses' Health Study II (n=116,000 women), and Health Professionals Follow-up Study (n=51,000 men). Over a period of 17 to 26 years, information has been collected prospectively on important exposures including diet, family history, body size measures, past medical history, and medications. We have confirmed over 2000 incident cases of kidney stones in each cohort (DK59583, PI Curhan). Further, we have collected 24-hour urine samples from over 4100 stone formers and non-stone formers; the majority of participants have performed two collections. The primary objective of this project is to examine the association between single nucleotide polymorphisms and the 24-hour urinary excretion of stone promoters (calcium and oxalate) and a stone inhibitor (citrate). The secondary objective is to explore the impact of interactions between the genetic factors and dietary factors on 24-hour urinary excretion of relevant lithogenic factors. These findings should provide new insight into regulation of these important factors and also into novel approaches for prevention of stone formation.</p>