Project description:Fibroblasts are present in every organ. While the role fibroblasts in chronic diseases such as fibrosis or tumor expression has been extensively explored, little is known about their physiological role. The kidney possesses a unique capacity to recover from even severe acute injury. We study molecular mechanisms of this intrinsic repair capacity in the mouse model of ischemia-reperfusion (IR). In this model, the renal artery and vein are clamped for 45 min, leading to acute kidney injury. The kidney spontaneously recovers from such IR injury within 14 days. IR kidney injury is associated with a transient accumulation of fibroblasts in the diseased tissue. We hypothesized that fibroblasts aid the repair of acute IR injury in the kidney. To elucidate how FSP1+ fibroblasts may contribute to the repair of kidney injury, we undertook a global unbiased approach to compare gene expression profiles of fibroblasts isolated from kidneys post-IRI and from control kidneys by FACS sorting. To investigate the role fibroblasts may play in the repair of kidney inhury, we performed ischemia reperfusion injury surgery on transgenic mice in which the FSP-1 promoter drives EGFP expression. Kidney injury peaks at day 3 post-IRI, followed by spontaneous regeration that restores nearly perfect kidney architecture and health by day 10. Fibroblasts are thought to possibly play a role in this process, as they are normally rare in the healthy kidney, acute kidney injury is associated with a transient accumulation of interstitial fibroblasts, but whether they may help repair the acute kidney injury or in fact could contribute to the damage is not known. To compare the gene expression profiles of normal fibroblasts and those from post-ischemic kidneys, we sacrificed control FSP1-GFP mice and the FSP1-GFP mice three days post-IRI. We generated single-cell suspensions from both the post-IRI and control kidneys, and then isolated FSP1-GFP+ cells by FACS sorting that, when cultured on plastic, displayed typical fibroblast morphology. Total RNA was immediately extracted from the sorted cells and amplified to produce enough for a array. We biotinylated five of the samples from post-ischemic kidneys and three of the control (non-ischemic) kidneys and used Affymetrix 3' Arrays to examine differences in gene expression profiles between the two groups that may she some light on what role, if any, fibroblasts play in the spontaneous healing of the kidney after acute kidney injury. We performed ischemia reperfusion surgery in FSP1-GFP mice, and at day 3, we sacrificed the mice, isolated FSP1-GFP positive cells from both IR and normal control kidneys by FACS sorting, extracted total RNA from the isolated FSP1-GFP cells and used Affymetrix Mouse Expression Array 430 2.0 microarrays to perform gene expression profiling of the samples. All told, we performed the FACS Sorting, RNA extration, and hybridization with 5 ischemic kidneys and 3 normal kidneys. Fibroblasts, acute kidney injury, repair, comparative gene expression profiling, microarrays, FACS sorting, role in healing
Project description:Fibroblasts are present in every organ. While the role fibroblasts in chronic diseases such as fibrosis or tumor expression has been extensively explored, little is known about their physiological role. The kidney possesses a unique capacity to recover from even severe acute injury. We study molecular mechanisms of this intrinsic repair capacity in the mouse model of ischemia-reperfusion (IR). In this model, the renal artery and vein are clamped for 45 min, leading to acute kidney injury. The kidney spontaneously recovers from such IR injury within 14 days. IR kidney injury is associated with a transient accumulation of fibroblasts in the diseased tissue. We hypothesized that fibroblasts aid the repair of acute IR injury in the kidney. To elucidate how FSP1+ fibroblasts may contribute to the repair of kidney injury, we undertook a global unbiased approach to compare gene expression profiles of fibroblasts isolated from kidneys post-IRI and from control kidneys by FACS sorting. To investigate the role fibroblasts may play in the repair of kidney inhury, we performed ischemia reperfusion injury surgery on transgenic mice in which the FSP-1 promoter drives EGFP expression. Kidney injury peaks at day 3 post-IRI, followed by spontaneous regeration that restores nearly perfect kidney architecture and health by day 10. Fibroblasts are thought to possibly play a role in this process, as they are normally rare in the healthy kidney, acute kidney injury is associated with a transient accumulation of interstitial fibroblasts, but whether they may help repair the acute kidney injury or in fact could contribute to the damage is not known. To compare the gene expression profiles of normal fibroblasts and those from post-ischemic kidneys, we sacrificed control FSP1-GFP mice and the FSP1-GFP mice three days post-IRI. We generated single-cell suspensions from both the post-IRI and control kidneys, and then isolated FSP1-GFP+ cells by FACS sorting that, when cultured on plastic, displayed typical fibroblast morphology. Total RNA was immediately extracted from the sorted cells and amplified to produce enough for a array. We biotinylated five of the samples from post-ischemic kidneys and three of the control (non-ischemic) kidneys and used Affymetrix 3' Arrays to examine differences in gene expression profiles between the two groups that may she some light on what role, if any, fibroblasts play in the spontaneous healing of the kidney after acute kidney injury.
Project description:Acute kidney injury (AKI) is a major health burden in the United States. Macrophages have been shown to mediate AKI in murine models. Murine kidneys contain multiple subpopulations of kidney resident macrophages (KRM) that are transcriptionally and spatially distinct. We hypothesized the human kidney contains orthologous KRM subpopulations, both transcriptionally and spatially. We utilized kidney sections from donors diagnosed with mild to moderate AKI in order to increase the translatability of murine research to clinical settings.
Project description:Ischemia-reperfusion injury (IRI) is a well-known model for acute kidney injury (AKI).
We applied proteomic analysis to detect membrane proteins from IRI mouse kidneys. The analysis set are composed of negative control (sham operation), samples of 4-hour after IRI, and samples of 8-hour IRI.
Project description:In the present study, goal was to scan the potential biomarker for acute kidney injury induced by aristolochic acid I (AAI).We utilized the microarry analysis to investigate the microRNA (miRNA) expression profile in kidneys from rat treated by 40mg/kg AA I for 2-6 days. miRNAs with significantly different expression of global miRNA expression profile were validated by qRT-PCR. For miRNAs still significantly disregulation, we further examined the expression in plasma of rats treated with AAI dosed at 10, 20 and 40mg/kg AAI for 2-6 days by qRT-PCR. miRNAs with significantly dysregulation in plasma, their expression in brain, liver and heart was examined for kicking out the non-specific disregulation in AAI induced acute kidney injury, so that the significant dysregulation miRNAs with specificity in kidney and plasma was found as potential biomarkers for AAI induced acute kidney injury. Five control and 15 kidneys treated with 40mg/kg AAI on day 2, 4 and 6 was examined by microarray.
Project description:Sepsis-associated acute kidney injury (SA-AKI) is a severe and life-threatening condi-tion with high morbidity and mortality among emergency patients, and it poses a sig-nificant risk of chronic renal failure. Clinical treatments for SA-AKI remain reactive and non-specific, lacking effective diagnostic biomarkers or treatment targets. In this study, we established an SA-AKI mouse model using LPS and performed proteomics and metabolomics analyses. A variety of bioinformatic analyses, including Gene Set En-richment Analysis (GSEA), Weighted Gene Co-expression Network Analysis (WGCNA), protein and protein interactions (PPI), and MetaboAnalyst analysis, were conducted to investigate the key molecules of SA-AKI. Proteomics and metabolomics analyses re-vealed that sepsis led to impaired renal mitochondrial function and metabolic disorders. Immune-related pathways were found to be activated in kidneys upon septic infection. The catabolic products of polyamines accumulated in septic kidneys. Overall, our study provides a more comprehensive understanding of SA-AKI and identifies potential pathways for this condition.
Project description:Microarray analysis of human kidneys with acute kidney injury (AKI) has been limited because such kidneys are seldom biopsied. However, all kidney transplants experience AKI, and early kidney transplants without rejection are an excellent model for human AKI: they are screened to exclude chronic kidney disease, frequently biopsied, and have extensive follow-up. We used histopathology and microarrays to compare indication biopsies from 28 transplants with AKI to 11 pristine protocol biopsies of stable transplants. Kidneys with AKI showed increased expression of 394 injury-repair response associated transcripts, including many known epithelial injury molecules (e.g. ITGB6, LCN2), tissue remodeling molecules (e.g. VCAN), and inflammation molecules (S100A8, ITGB3). Many other genes also predict the phenotype, depending on statistical filtering rules, including AKI biomarkers as HAVCR1 and IL18. Most mouse orthologs of the top injury-repair transcripts were increased in published mouse AKI models. Pathway analysis of the injury-repair transcripts revealed similarities to cancer, development, and cell movement. The injury-repair transcript score AKI kidneys correlated with reduced function, future recovery, brain death, and need for dialysis, but not future graft loss. In contrast, histologic features of "acute tubular injury" did not correlate with function or with the molecular changes. Thus the injury-repair associated transcripts represent a massive coordinate injury-repair response of kidney parenchyma to AKI, similar to mouse AKI models, and provide an objective measure for assessing the severity of AKI in kidney biopsies and validation for the use of many AKI biomarkers. AKI biopsies sample names and CEL files are from GSE21374. All consenting renal transplant patients undergoing biopsies for cause as standard of care between 09/2004 and 10/2007 at the university of Alberta or between 11/2006 and 02/2007 at the University of Illinois were included in the analysis. In addition to the cores required for standard histopathology, we collected one core for gene expression studies. the relationship between gene expression in the biopsy and subsequent graft loss was analyzed. This dataset is part of the TransQST collection.
Project description:Congenital obstructive nephropathy is a common cause of chronic kidney disease and a leading indication for renal transplant in children. The cellular and molecular responses of the kidney to congenital obstruction are incompletely characterized. In this study, we evaluated global transcription in kidneys with graded hydronephrosis in the megabladder (mgb-/-) mouse to better understand the pathophysiology of congenital obstructive nephropathy. Three primary pathways associated with kidney remodeling/repair were induced in mgb-/- kidneys independent of the degree of hydronephrosis. These pathways included retinoid signaling, steroid hormone metabolism, and renal response to injury. Urothelial proliferation and the expression of genes with roles in the integrity and maintenance of the renal urothelium were selectively increased in mgb-/- kidneys. Ngal/Lcn2, a marker of acute kidney injury, was elevated in 36% of kidneys with higher grades of hydronephrosis. Evaluation of Ngalhigh versus Ngallow kidneys identified the expression of several novel candidate markers of renal injury. This study indicates that the development of progressive hydronephrosis in mgb-/- mice results in renal adaptation that includes significant changes in the morphology and potential functionality of the renal urothelium. These observations will permit the development of novel biomarkers and therapeutic approaches to progressive renal injury in the context of congenital obstruction. Gene expression was measured in control, mild, moderate and severely hydronephrotic megabladder mouse kidneys. A total of 6 control kidneys were compared to 18 mutant kidneys from age-matched male animals.
Project description:To clarify the effects of cisplatin (cis-diamminedichloroplatinum II, CDDP) on the gene expression profiles in renal proximal tubules, microarray analyses were carried out using total RNA samples isolated from microdissected proximal tubules and whole kidneys. The molecular events underlying acute kidney injury (AKI) in the proximal tubules of rats with cisplatin-induced nephrotoxicity were successfully clarified with 17,000 transcripts.