Label-free quantitative proteomics for mouse kidney tissue of unilateral ureteral obstruction (UUO) vs Sham.
ABSTRACT: Label-free quantitative proteomics for mouse kidney tissue of UUO vs Sham was used for discovery of differential expressed proteins in the process of renal fibrosis. Compared to sham mice, we found that 216 upregulated proteins and 215 downregulated proteins in UUO mice according to fold change ≥ 5, adjusted-p ≤ 0.01. Then, we will study the potential mechanism according to differential expressed proteins.
Project description:Congenital obstructive nephropathy hinders normal kidney development. The severity and the duration of obstruction determine the compensatory growth of the contralateral, intact opposite kidney. We investigated the regulation of renal developmental genes, that are relevant in congenital anomalies of the kidney and urinary tract (CAKUT) in obstructed and contralateral (intact opposite) kidneys after unilateral ureteral obstruction (UUO) in neonatal and adult mice. Newborn and adult mice were subjected to complete UUO or sham-operation, and were sacrificed 1, 5, 12 and 19 days later. Quantitative RT-PCR was performed in obstructed, intact opposite kidneys and sham controls for Gdnf, Pax2, Six4, Six2, Dach1, Eya1, Bmp4, and Hnf-1?. Neonatal UUO induced an early and strong upregulation of all genes. In contrast, adult UUO kidneys showed a delayed and less pronounced upregulation. Intact opposite kidneys of neonatal mice revealed a strong upregulation of all developmental genes, whereas intact opposite kidneys of adult mice demonstrated only a weak response. Only neonatal mice exhibited an increase in BMP4 protein expression whereas adult kidneys strongly upregulated phosphatidylinositol 3 kinase class III, essential for compensatory hypertrophy. In conclusion, gene regulation differs in neonatal and adult mice with UUO. Repair and compensatory hypertrophy involve different genetic programs in developing and adult obstructed kidneys.
Project description:Renal scintigraphy using 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) is widely used for the assessment of renal function in humans. However, the application of this method to animal models of renal disease is currently limited, especially in rodents. Here, we have applied 99mTc-MAG3 renal scintigraphy to a mouse model of unilateral ureteral obstruction (UUO) and evaluated its utility in studying obstructive renal disease.UUO mice were generated by complete ligation of the left ureter. Sham-operated mice were used as a control. Renal function was investigated on days 0, 1, 3, and 6 post-surgery using dynamic planar imaging of 99mTc-MAG3 activity following retro-orbital injection. Time-activity curves (TACs) were produced for individual kidneys and renal function was assessed by 1) the slope of initial 99mTc-MAG3 uptake (SIU), which is related to renal perfusion; 2) peak activity; and 3) the time-to-peak (TTP). The parameters of tubular excretion were not evaluated in this study as 99mTc-MAG3 is not excreted from UUO kidneys.Compared to sham-operated mice, SIU was remarkably (>60%) reduced in UUO kidneys at day 1 post surgery and the TACs plateaued, indicating that 99mTc-MAG3 is not excreted in these kidneys. The plateau activity in UUO kidneys was relatively low (~40% of sham kidney's peak activity) as early as day1 post surgery, demonstrating that uptake of 99mTc-MAG3 is rapidly reduced in UUO kidneys. The time to plateau in UUO kidneys exceeded 200 sec, suggesting that 99mTc-MAG3 is slowly up-taken in these kidneys. These changes advanced as the disease progressed. SIU, peak activity and TTPs were minimally changed in contra-lateral kidneys during the study period.Our data demonstrate that renal uptake of 99mTc-MAG3 is remarkably and rapidly reduced in UUO kidneys, while the changes are minimal in contra-lateral kidneys. The parametric analysis of TACs suggested that renal perfusion as well as tubular uptake is reduced in UUO kidneys. This imaging technique should allow non-invasive assessments of UUO renal injury and enable a more rapid interrogation of novel therapeutic agents and protocols.
Project description:Although inflammation and fibrosis, which are key mechanisms of chronic kidney disease, are associated with mitochondrial damage, little is known about the effects of mitochondrial damage on the collecting duct in renal inflammation and fibrosis. To generate collecting duct-specific mitochondrial injury mouse models, CR6-interacting factor-1 (CRIF1) <sup>flox/flox</sup> mice were bred with Hoxb7-Cre mice. We evaluated the phenotype of these mice. To evaluate the effects on unilateral ureteral obstruction (UUO)-induced renal injury, we divided the mice into the following four groups: a CRIF1<sup>flox/flox</sup> (wild-type (WT)) group, a CRIF1<sup>flox/flox</sup>-Hob7 Cre (CRIF1-KO) group, a WT-UUO group, and a CRIF1-KO UUO group. We evaluated the blood and urine chemistries, inflammatory and fibrosis markers, light microscopy, and electron microscopy of the kidneys. The inhibition of <i>Crif1</i> mRNA in mIMCD cells reduced oxygen consumption and membrane potential. No significant differences in blood and urine chemistries were observed between WT and CRIF1-KO mice. In UUO mice, monocyte chemoattractant protein-1 and osteopontin expression, number of F4/80 positive cells, transforming growth factor-β and α-smooth muscle actin staining, and Masson's trichrome staining were significantly higher in the kidneys of CRIF1-KO mice compared with the kidneys of WT mice. In sham mice, urinary 8-hydroxydeoxyguanosine (8-OHDG) was higher in CRIF1-KO mice than in WT mice. Moreover, CRIF1-KO sham mice had increased 8-OHDG-positive cell recruitment compared with WT-sham mice. CRIF1-KO-UUO kidneys had increased recruitment of 8-OHDG-positive cells compared with WT-UUO kidneys. In conclusion, collecting duct-specific mitochondrial injury increased oxidative stress. Oxidative stress associated with mitochondrial damage may aggravate UUO-induced renal injury.
Project description:Renal fibrosis is a progressive histological manifestation leading to chronic kidney disease (CKD) and associated with mitochondrial dysfunction. In previous work, we showed that Bemcentinib, an Axl receptor tyrosine kinase inhibitor, reduced fibrosis development. In this study, to investigate its effects on mitochondrial dysfunction in renal fibrosis, we analysed genome-wide transcriptomics data from a unilateral ureter obstruction (UUO) murine model in the presence or absence of bemcentinib (n = 6 per group) and SHAM-operated (n = 4) mice. Kidney ligation resulted in dysregulation of mitochondria-related pathways, with a significant reduction in the expression of oxidative phosphorylation (OXPHOS), fatty acid oxidation (FAO), citric acid cycle (TCA), response to reactive oxygen species and amino acid metabolism-related genes. Bemcentinib treatment increased the expression of these genes. In contrast, AKT/PI3K signalling pathway genes were up-regulated upon UUO, but bemcentinib largely inhibited their expression. At the functional level, ligation reduced mitochondrial biomass, which was increased upon bemcentinib treatment. Serum metabolomics analysis also showed a normalizing amino acid profile in UUO, compared with SHAM-operated mice following bemcentinib treatment. Our data suggest that mitochondria and mitochondria-related pathways are dramatically affected by UUO surgery and treatment with Axl-inhibitor bemcentinib partially reverses these effects.
Project description:Urine has the potential to become a better source of biomarkers. Urinary proteins are affected by many factors; therefore, differentiating between the variables associated with any particular pathophysiological condition in clinical samples is challenging. To circumvent these problems, simpler systems, such as animal models, should be used to establish a direct relationship between disease progression and urine changes. In this study, a unilateral ureteral obstruction (UUO) model was used to observe tubular injury and the eventual development of renal fibrosis, as well as to identify differential urinary proteins in this process. Urine samples were collected from the residuary ureter linked to the kidney at 1 and 3 weeks after UUO. Five hundred proteins were identified and quantified by LC-MS/MS, out of which 7 and 19 significantly changed in the UUO 1- and 3-week groups, respectively, compared with the sham-operation group. Validation by western blot showed increased levels of Alpha-actinin-1 and Moesin in the UUO 1-week group, indicating that they may serve as candidate biomarkers of renal tubular injury, and significantly increased levels of Vimentin, Annexin A1 and Clusterin in the UUO 3-week group, indicating that they may serve as candidate biomarkers of interstitial fibrosis.
Project description:<h4>Background</h4>Fabry disease is a rare X-linked genetic lysosomal disorder caused by mutations in the GLA gene encoding alpha-galactosidase A. Despite some data showing that profibrotic and proinflammatory cytokines and oxidative stress could be involved in Fabry disease-related renal injury, the pathogenic link between metabolic derangement within cells and renal injury remains unclear.<h4>Methods</h4>Renal fibrosis was triggered by unilateral ureteral obstruction (UUO) in mice with Fabry disease to investigate the pathogenic mechanism leading to fibrosis in diseased kidneys.<h4>Results</h4>Compared to kidneys of wild-type mice, lamellar inclusion bodies were recognized in proximal tubules of mice with Fabry disease. Sirius red and trichrome staining revealed significantly increased fibrosis in all UUO kidneys, though it was more prominent in obstructed Fabry kidneys. Renal messenger RNA levels of inflammatory cytokines and profibrotic factors were increased in all UUO kidneys compared to sham-operated kidneys but were not significantly different between UUO control and UUO Fabry mice. Protein levels of Nox2, Nox4, NQO1, catalase, SOD1, SOD2, and Nrf2 were not significantly different between UUO control and UUO Fabry kidneys, while the protein contents of LC3-II and LC3-I and expression of Beclin1 were significantly decreased in UUO kidneys of Fabry disease mouse models compared with wild-type mice. Notably, TUNEL-positive cells were elevated in obstructed kidneys of Fabry disease mice compared to wild-type control and UUO mice.<h4>Conclusion</h4>These findings suggest that impaired autophagy and enhanced apoptosis are probable mechanisms involved in enhanced renal fibrosis under the stimulus of UUO in Fabry disease.
Project description:Desorption electrospray ionization mass spectrometry (DESI-MS) is an emerging analytical tool for rapid in situ assessment of metabolomic profiles on tissue sections without tissue pretreatment or labeling. We applied DESI-MS to identify candidate metabolic biomarkers associated with kidney injury at the early stage. DESI-MS was performed on sections of kidneys from 80 mice over a time course following unilateral ureteral obstruction (UUO) and compared to sham controls. A predictive model of renal damage was constructed using the LASSO (least absolute shrinkage and selection operator) method. Levels of lipid and small metabolites were significantly altered and glycerophospholipids comprised a significant fraction of altered species. These changes correlate with altered expression of lipid metabolic genes, with most genes showing decreased expression. However, rapid upregulation of PG(22:6/22:6) level appeared to be a hitherto unknown feature of the metabolic shift observed in UUO. Using LASSO and SAM (significance analysis of microarrays), we identified a set of well-measured metabolites that accurately predicted UUO-induced renal damage that was detectable by 12 h after UUO, prior to apparent histological changes. Thus, DESI-MS could serve as a useful adjunct to histology in identifying renal damage and demonstrates early and broad changes in membrane associated lipids.
Project description:In unilateral ureteral obstruction (UUO), both oxidative stress and mitochondrial dysfunction are related to cell death. The aim of this study has been to characterize profiles of enzyme antioxidant activities and mitochondrial functioning of the contralateral (CL) compared to UUO and Sham (false-operated) kidneys of Balb/c mice. Kidneys were resected 14 days after obstruction for immunohistochemical and cortical mitochondrial functioning assays. Antioxidant enzymes activities were investigated in mitochondria and cytosol. Oxygen consumption (QO2) and formation of O2 reactive species (ROS) were assessed with pyruvate plus malate or succinate as the respiratory substrates. QO2 decreased in CL and UUO in all states using substrates for complex II, whereas it was affected only in UUO when substrates for complex I were used. Progressive decrease in mitochondrial ROS formation-in the forward and reverse pathway at complex I-correlates well with the inhibition of QO2 and, therefore, with decreased electron transfer at the level of complexes upstream of cytochrome c oxidase. CL and UUO transmembrane potential responses to ADP were impaired with succinate. Intense Ca2+-induced swelling was elicited in CL and UUO mitochondria. Important and selective differences exist in CL antioxidant enzymes with respect to either Sham or UUO kidneys: CL kidneys had increased mitochondrial glutathione peroxidase and cytosolic catalase activities, indicative of compensatory responses in the face of an early altered ROS homeostasis (as detected by 4-hydroxynonenal), and of a significant tendency to apoptosis. In CL and UUO, upregulation of nuclear (erythroid-derived 2)-like 2 transcription factor (Nrf2), as well as of cytoplasmic and nuclear Kelch-like ECH-associated protein 1 (Keap1) in opposition to decreased heme oxygenase-1 (HO-1), suggest impairment of the Nrf2/Keap1/HO-1 system. It is concluded that chronic obstruction impairs mitochondrial function in CL and UUO, preferentially affecting complex II.
Project description:Renal fibrosis leads to end-stage renal disease, but antifibrotic drugs are difficult to develop. Chronic kidney disease often results in muscle wasting, and thereby increases morbidity and mortality. In this work, adeno-associated virus (AAV)-mediated overexpressing miR-29a was hypothesized to counteract renal fibrosis and muscle wasting through muscle-kidney crosstalk in unilateral ureteral obstruction (UUO) mice. miR-29a level was downregulated in the kidney and skeletal muscle of UUO mice. The secretion of exosome-encapsulated miR-29a increased in cultured skeletal muscle satellite cells and HEK293 renal cells after stimulation with serum from UUO mice. This result was confirmed by qPCR and microRNA deep sequencing in the serum exosomes of mice with obstructed ureters. A recombinant AAV-miR-29a was generated to overexpress miR-29a and injected into the tibialis anterior muscle of the mice 2 weeks before UUO surgery. AAV-miR-29a abrogated the UUO-induced upregulation of YY1 and myostatin in skeletal muscles. Renal fibrosis was also partially improved in the UUO mice with intramuscular AAV-miR-29a transduction. AAV-miR-29a overexpression reversed the increase in transforming growth factor ?, fibronectin, alpha-smooth muscle actin, and collagen 1A1 and 4A1 levels in the kidney of UUO mice. AAV-green fluorescent protein was applied to trace the AAV route <i>in vivo</i>, and fluorescence was significantly visible in the injected/uninjected muscles and in the kidneys. In conclusion, intramuscular AAV-miR-29a injection attenuates muscle wasting and ameliorates renal fibrosis by downregulating several fibrotic-related proteins in UUO mice.