Project description:The present study aims to assess the potential changes in microRNAs of proximal renal tubular cells in response to the adhesion of calcium oxalate monohydrate (COM) crystals. microRNA microarray was applied to evaluate the expression of HK-2 cells exposed to COM crystals for 0 and 24 hours.
Project description:The present study aims to assess the potential changes in microRNAs of proximal renal tubular cells in response to the adhesion of calcium oxalate monohydrate (COM) crystals.
Project description:The present study aims to assess the potential changes in LncRNAs of proximal renal cells in response to the adhesion of calcium oxalate monohydrate (COM) crystals.
Project description:The present study aims to assess the potential changes in LncRNAs of proximal renal cells in response to the adhesion of calcium oxalate monohydrate (COM) crystals. lncRNA microarray were applied to evaluate the expression of HK-2 cells exposed to COM crystal for 0 and 24 hours.
Project description:Previous studies have proposed that production of reactive oxygen species (ROS) is an important contributor to renal injury and inflammation following exposure to oxalate or calcium-oxalate crystals. The present study was conducted to determine, utilizing global transcriptome analyses, if the NADPH oxidase system is activated in kidneys of rats fed a diet leading to hyperoxaluria and crystal deposition. HLP was used to induce hyperoxaluria. Hyperoxaluria will lead to crystallization and up regulation of various NADPH oxidase subunits followed by increased expression of different specific genes. It is our hypothesis that crystallization induces inflammation of the kidneys via the activation of renin-angiotensin system (RAS) and production of reactive oxygen species (ROS) through NADPH oxidase complex. Apocynin was used to block hyperoxaluria and production of reactive oxygen species (ROS) with the inhibition of NADPH oxidase system as Apocynin inhibits membrane translocation of p47 subunit of NADPH oxidase.
Project description:The present study aims to compare the miRNA expression profiles in exosomes derived from HK-2 cells treated with 0, 1, 2 mM sodium oxalate, and to explore the roles of different exosomal-miRNAs in the regulation of calcium oxalate (CaOx) stones formation.
Project description:Previous studies have proposed that production of reactive oxygen species (ROS) is an important contributor to renal injury and inflammation following exposure to oxalate or calcium-oxalate crystals. The present study was conducted to determine, utilizing global transcriptome analyses, if the NADPH oxidase system is activated in kidneys of rats fed a diet leading to hyperoxaluria and crystal deposition. HLP was used to induce hyperoxaluria. Hyperoxaluria will lead to crystallization and up regulation of various NADPH oxidase subunits followed by increased expression of different specific genes. It is our hypothesis that crystallization induces inflammation of the kidneys via the activation of renin-angiotensin system (RAS) and production of reactive oxygen species (ROS) through NADPH oxidase complex. Apocynin was used to block hyperoxaluria and production of reactive oxygen species (ROS) with the inhibition of NADPH oxidase system as Apocynin inhibits membrane translocation of p47 subunit of NADPH oxidase. The present study was designed based on NADPH oxidase system and rats were divided into 4 groups (n= 6/group). Group 1 was fed regular rat chow diet, Group 2 received regular rat chow diet supplemented with 5% (Hydroxy-L-Proline) HLP, Group 3 received rat chow diet with 4 mmol Apocynin to drink, and Group 4 received regular rat chow diet with 5% HLP and 4 mmol Apocynin. After 28 days each rat was euthanized, their kidneys freshly explanted and dissected to obtain both cortex and medulla tissues. So the 4 groups were divided into cortex and medulla forming 8 groups. RNA was isolated from all the 8 specimens
Project description:Calcium oxalate stones account for over 80% of urinary stones, while the molecular mechanism of its formation is still not completely elucidated. The incidence of hyperoxaluria in calcium oxalate stone formation ranks only second to hypercalciuria. It plays an important role in the pathophysiological process of stone formation. We analyzed miRNA expression profiles between experimental hyperoxaluric rats and normal rats in order to find out the target genes and signaling pathways in the pathogenesis of hyperoxaluria.
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:Kidney stones (KS) are very common, excruciating, and are associated with tremendous healthcare cost, chronic kidney disease (CKD), and end stage renal disease (ESRD). Most KS are composed of calcium oxalate and very small increases in urine oxalate concentration increase the risk for stone formation. Besides its critical role in the pathogenesis of KS, emerging data suggest that disturbed oxalate homeostasis (hyperoxaluria and/or hyperoxalemia) contributes to CKD progression, CKD - and ESRD-associated cardiovascular diseases, progression of cyst growth in autosomal dominant polycystic kidney disease (ADPKD), and delayed graft function & poor renal allograft survival. This emphasizes the urgent need for plasma and urinary oxalate lowering therapies, and enhancing the bowel’s ability to secrete oxalate may effectively do so. We previously identified Oxalobacter formigenes (O. formigenes)-derived factors secreted in its culture conditioned medium (CM) which stimulated oxalate transport by human intestinal Caco2-BBE (C2) cells and reduced urinary oxalate excretion in hyperoxaluric mice by enhancing colonic oxalate secretion. Given their remarkable therapeutic potential, we now identified several proteins belonging to Sel1-like family as the major O. formigenes-derived secreted factors, and we determined the crystal structures for six proteins to better understand their function. Importantly, Sel1-14-derived small peptides P8 & P9 were identified as the major factors, with P8+9 closely recapitulate the CM’s effects, including acting through the oxalate transporters SLC26A2 & SLC26A6 and PKA activation. P8+9 also stimulate oxalate transport by human ileal and colonic organoids, confirming that these peptides work in human tissues. Collectively, the identification of these small peptides provide a great opportunity for developing a peptide-based novel therapeutic for hyperoxalemia, hyperoxaluria, and related disorders, impacting the outcomes of patients suffering from KS, primary hyperoxaluria, CKD, ADPKD, ESRD, and renal transplant recipients.