Project description:Kidney disease development is poorly understood due to the complex cellular interactions of more than 25 different cell types, each with specialized functions. Here, we used single cell RNA-sequencing to resolve cell type-specific and cell fraction changes in kidney disease. Whole kidney RNA-sequencing results were strongly influenced by cell fraction changes, but minimally informative to detect cell type-specific gene expression changes. Cell type-specific differential expression analysis identified proximal tubule cells (PT cells) as the key vulnerable cell type in diseased kidneys. Through unbiased cell trajectory analyses, we show that PT cell differentiation state is altered in disease state. Metabolism (fatty acid oxidation and oxidative phosphorylation) in PT cells showed the strongest and reproducible association with PT cells state. The coupling of cell state and metabolism is established by nuclear receptors such as ESRRA that not only control cellular metabolism but also the expression of PT cell-specific genes in mice and patient samples.
Project description:Circadian variability in kidney function has long been recognized but is often ignored as a potential confounding variable in in vivo physiological experiments. To provide a guide for physiological studies on the kidney proximal tubule, we have now created a data resource consisting of expression levels for all measurable mRNA transcripts in microdissected proximal tubule segments from mice as a function of the time of day. This approach employs small-sample RNA-sequencing (RNA-seq) applied to microdissected renal proximal tubules including both S1 proximal convoluted tubules (PCTs) and S2 proximal straight tubules (PSTs). The data were analyzed using JTK-Cycle to detect periodicity. The data are provided as a user-friendly web page at https://esbl.nhlbi.nih.gov/Databases/Circadian-Prox/. In PCTs, 234 transcripts were found to vary in a circadian manner (3.7 % of total quantified). In PSTs, 334 transcripts were found to vary in a circadian manner (5.3 % of total quantified). Transcripts previously known to be associated with corticosteroid action and transcripts associated with increased flow were found to be overrepresented among circadian transcripts peaking during the “dark” portion of the day (Zeitgeber 14-22), corresponding to the peak levels of corticosterone and glomerular filtration rate in mice.
Project description:Freshly isolated rat kidney proximal tubules were subjected for transcript profiling. Three microarray experiments were done to obtain the kidney proxmial tubule transcriptome.
Project description:Global gene expression in the primary cultured mouse kidney proximal tubule cells treated either DMSO or 1uM GW4064 (a FXR agonist) was compared. Results provide insight into mechanisms underlying effects of FXR activation on gene expression in mouse kidney proximal tubule cells. Male C57/BJ mice aged 6 weeks were sacrificed under anesthesia and kidney proximal tubule cells were cultured until confluent. Cells were treated with either GW4064 (1uM) or equal amount of DMSO and incubated for 24 hours. 4 total RNA samples per group were analyzed and gene expression was compared between the groups.
Project description:We performed bulk RNA-seq on primary and immortalized human renal proximal tubule epithelial cells (RPTECs) subjected to siRNA mediated TNIK silencing.
Project description:Purpose:Cultured cell lines are widely used for research in the physiology, pathophysiology, toxicology and pharmacology of the renal proximal tubule. The lines that are most appropriate for a given use depend on the genes expressed.We have used modern RNA-sequencing techniques to identify the gene expression profile of 14 different cell lines plus primary cultures of mouse proximal tubule and compare them to transcriptomes of native kidney proximal tubules. Methods: 14 different proximal tubule cell lines were grown on permeable supports under conditions specific for the respective lines. RNA-Seq followed standard procedures. Results and conclusion: Transcripts expressed in cell lines showed variable match to transcripts selectively expressed in native proximal tubule. Opossum kidney (OK) cells displayed the highest percentage match (45%) with pig kidney cells (LLC-PK1) close behind (39%). Much lower percentage matches were seen for various human lines including HK-2 cells (26%) and lines from rodent kidneys (18-23%).An online resource (https://esbl.nhlbi.nih.gov/JBrowse/KCT/) has been created for interrogation of the data.No cell line closely matched the transcriptome of native proximal tubule cells. However, some of the lines tested are suitable for the study of particular metabolic and transport processes seen in the proximal tubule.
Project description:This study reports the cellular self-organization of primary human renal proximal tubule epithelial cells (RPTECs) around a minimal Matrigel scaffold to produce basal-in and apical-out proximal tubule organoids (tubuloids). These tubuloids are produced and maintained in hanging drop cultures for 90+ days, the longest such culture of any kind reported to date. The tubuloids upregulate maturity markers, such as aquaporin-1 (AQP1) and megalin (LRP2), and exhibit less mesenchymal and proliferation markers, such as vimentin and Ki67, compared to 2D cultures. They also experience changes over time as revealed by a comparison of gene expression patterns of cells in 2D culture and in day 31 and day 67 tubuloids. Gene expression analysis and immunohistochemistry reveal an increase in the expression of megalin, an endocytic receptor that can directly bind and uptake protein or potentially assist protein uptake. The tubuloids, including day 90 tubuloids, uptake fluorescent albumin and reveal punctate fluorescent patterns, suggesting functional endocytic uptake through these receptors. Furthermore, the tubuloids release kidney injury molecule-1 (KIM-1), a common biomarker for kidney injury, when exposed to albumin in both dose- and time-dependent manners. While this study focuses on potential applications for modeling proteinuric kidney disease, the tubuloids may have broad utility for studies where apical proximal tubule cell access is required.
Project description:Injury to the proximal tubule plays a central role in the initiation and progression of kidney fibrosis, and rates of chronic kidney disease progresses approximately 50% faster in males compared to females. We applied Translating Ribosome Affinity Purification (TRAP) followed by RNA-sequencing to characterize the cell-specific proximal tubule transcriptional landscape during fibrosis in male vs. female mice.
Project description:Cultured cell lines are widely used for research in the physiology, pathophysiology, toxicology and pharmacology of the renal proximal tubule. The lines that are most appropriate for a given use depend on the genes expressed. New tools for transcriptomic and proteomic profiling using RNA-sequencing (RNA-Seq) and mass spectrometry make it possible to catalog expressed genes in each cell line. This data set is the protoemic data of Rat NRK-52E cell line. We concludeno cell line fully matched the transcriptome of native proximal tubule cells. However, some of the lines tested are suitable for the study of particular metabolic and transport processes seen in the proximal tubule.
Project description:Global gene expression in primary cultured mouse kidney proximal tubule cells treated with either DMSO or 1uM GW4064 (an FXR agonist) was compared. Results provide insight into mechanisms underlying effects of FXR activation on gene expression in mouse kidney proximal tubule cells.