Project description:Uric acid (UA) is the final product of purine metabolism and plays an important role as a physiological antioxidant. In recent years, several different groups have reported a correlation between decreased UA in Parkinson’s disease (PD) and clinical progression and stage of PD. However, little is known about the molecular mechanisms of decreased UA under oxidative stress. We used our systematic functional annotation pipeline for silkworm genes to identify a novel UA metabolic pathway regulator under oxidative stress in a UA metabolism mutant silkworm Bombyx mori model. Gene expression was measured in 3day of fifth instar larvae of abnormal uric acid synthesis Bombyx mori mutant of op.
Project description:Natural flavonoid pectolinarigenin (PEC) was reported to alleviate tubulointerstitial fibrosis of unilateral ureteral obstruction (UUO) mice in our previous study. To further investigate nephroprotective effects of PEC in hyperuricemic nephropathy (HN), adenine and potassium oxonate induced HN mice and uric acid-treated mouse kidney epithelial (TCMK-1) cells were employed in the study. As a result, PEC significantly lowered serum uric acid level and restored hyperuricemia-related kidney injury in HN mice. Meanwhile, PEC alleviated inflammation, fibrosis and reduced adipokine FABP4 content in the kidneys of HN mice and uric acid-treated TCMK-1 cells. Mechanistically, PEC inhibited the TGF-β1 expression as well as the phosphorylation of transcription factor SMAD3 and STAT3 to regulate the corresponding inflammatory and fibrotic gene expression in kidney tissues. In conclusion, our results suggested that PEC could inhibit the activation of SMAD3 and STAT3 signaling to suppress inflammation and fibrosis, thereby alleviate HN in mice.
Project description:Approximately 15% of US adults have circulating levels of uric acid above its solubility limit, which is causally linked to the inflammatory disease gout. In most mammals, uric acid elimination is facilitated by the enzyme uricase. However, human uricase is a pseudogene, having been inactivated early in hominid evolution. Though it has long been known that a substantial amount of uric acid is eliminated in the gut, the role of the gut microbiota in hyperuricemia has not been studied. Here we identify a gene cluster, widely distributed in the gut microbiome, that encodes a pathway for uric acid degradation. Stable isotope tracing demonstrates that gut bacteria metabolize uric acid to xanthine or short chain fatty acids such as acetate, lactate and butyrate. Ablation of the microbiota in uricase-deficient mice causes profound hyperuricemia, and anaerobe-targeted antibiotics increase the risk of gout in humans. These data reveal a role for the gut microbiota in uric acid excretion and highlight the potential for microbiome-targeted therapeutics in hyperuricemia.
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:Kidney stone disease is influenced by multiple factors, including but not limited to age, gender, genetic background, hydration status, diet and drug. Regarding the gender, epidemiologic data across the world has shown that females at the reproductive age (15-49 years) have lower incidence/prevalence of kidney stone disease approximately 1.5-2.5 folds as compared to males at the same age. However, this gap is narrower in the postmenopausal age, whereas the postmenopausal females with higher serum estrogen levels are less likely to have kidney stones. Furthermore, female stone formers (patients with kidney stones) are associated with lower estrogen levels. Therefore, estrogen has been proposed to serve as the protective hormone against kidney stone disease. However, the precise mechanisms underlying such protective effects of estrogen remain unclear and require further investigations. This study thus investigated the effects of estradiol (which is the most prevalent and potent form of estrogen in females at the reproductive age) on cellular proteome of renal tubular cells using a proteomics approach.
Project description:Kidney stone disease causes significant morbidity and increases health care utilization. The pathogenesis of stone disease is incompletely understood, due in part to the poor characterization of the cellular and molecular makeup of the human papilla and its alteration with disease. In this work, we characterize the human renal papilla in health and calcium oxalate stone disease using single nuclear RNA sequencing, spatial transcriptomics and high-resolution large scale multiplexed 3D and Co-Detection by indexing (CODEX) imaging. We define and localize subtypes of principal cells enriched in the papilla as well as immune and stromal cell populations. We further uncovered an undifferentiated epithelial cell signature in the papilla, particularly during nephrolithiasis.
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.