Project description:Renal excretion of water and major electrolytes exhibits a significant circadian rhythm. This functional periodicity is believed to result, at least in part, from circadian changes in secretion/reabsorption capacities of the distal nephron and collecting ducts. Here, we studied the molecular mechanisms underlying circadian rhythms in the distal nephron segments, i.e. distal convoluted tubule (DCT) and connecting tubule (CNT) and, the cortical collecting duct (CCD). Temporal expression analysis performed on microdissected mouse DCT/CNT or CCD revealed a marked circadian rhythmicity in the expression of a large number of genes crucially involved in various homeostatic functions of the kidney. This analysis also revealed that both DCT/CNT and CCD possess an intrinsic circadian timing system characterized by robust oscillations in the expression of circadian core clock genes (clock, bma11, npas2, per, cry, nr1d1) and clock-controlled Par bZip transcriptional factors dbp, hlf and tef. The clock knockout mice or mice devoid of dbp/hlf/tef (triple knockout) exhibit significant changes in renal expression of several key regulators of water or sodium balance (vasopressin V2 receptor, aquaporin-2, aquaporin-4, M-oM-^AM-!ENaC). Functionally, the loss of clock leads to a complex phenotype characterized by partial diabetes insipidus, dysregulation of sodium excretion rhythms and a significant decrease in blood pressure. Collectively, this study uncovers a major role of molecular clock in renal function. Experiment Overall Design: We examined the temporal profiles of gene expression in mouse distal nephron segments and collecting ducts. The RNA was extracted from microdissected distal convoluted tubules and connecting tubules (DCT/CNT samples) or, cortical collecting ducts (CCD samples). Animals were sacrificed for microdissection every 4 hours, i.e. at ZT0, ZT4, ZT8, ZT12, ZT16 and ZT20 (ZT M-bM-^@M-^S Zeitgeber (circadian) time, indicates time of light-on as ZT0 and time of light-off as ZT12). The microarray hybridization was performed in duplicates on two pools of RNA composed of equivalent amounts of RNA prepared from five animals at each ZT time-point.
Project description:Renal excretion of water and major electrolytes exhibits a significant circadian rhythm. This functional periodicity is believed to result, at least in part, from circadian changes in secretion/reabsorption capacities of the distal nephron and collecting ducts. Here, we studied the molecular mechanisms underlying circadian rhythms in the distal nephron segments, i.e. distal convoluted tubule (DCT) and connecting tubule (CNT) and, the cortical collecting duct (CCD). Temporal expression analysis performed on microdissected mouse DCT/CNT or CCD revealed a marked circadian rhythmicity in the expression of a large number of genes crucially involved in various homeostatic functions of the kidney. This analysis also revealed that both DCT/CNT and CCD possess an intrinsic circadian timing system characterized by robust oscillations in the expression of circadian core clock genes (clock, bma11, npas2, per, cry, nr1d1) and clock-controlled Par bZip transcriptional factors dbp, hlf and tef. The clock knockout mice or mice devoid of dbp/hlf/tef (triple knockout) exhibit significant changes in renal expression of several key regulators of water or sodium balance (vasopressin V2 receptor, aquaporin-2, aquaporin-4, alphaENaC). Functionally, the loss of clock leads to a complex phenotype characterized by partial diabetes insipidus, dysregulation of sodium excretion rhythms and a significant decrease in blood pressure. Collectively, this study uncovers a major role of molecular clock in renal function. Keywords: time course
Project description:The kidney is the main hematopoietic organ in teleost fish. Various stages of hematopoietic cells were observed in the interstitial tissue of the kidney. We recently demonstrated that zebrafish hematopoietic stem cells (HSCs) expressing jam1a were specifically localized along the renal collecting ducts in the adult kidney. Interestingly, most of HSCs invaded into the intracellular spaces of the epithelium in collecting ducts, suggesting that collecting ducts provide a specific microenvironment for HSCs. In order to identify niche factors in collecting ducts, we performed microarray analysis in collecting ducts isolated from the Tg(jam1a:EGFP) zebrafish kidney. Collecting ducts were isolated from Tg(jam1a:EGFP) zebrafish under a fluorescent microscope. To examine the effect of X-ray irradiation on the niche, collecting ducts were isolated from the fish irradiated with 25Gy. The whole kidney tissues were also used for a comparison analysis. Two independent replicates consisting of five zebrafish were prepared for each sample.
Project description:The kidney is the main hematopoietic organ in teleost fish. Various stages of hematopoietic cells were observed in the interstitial tissue of the kidney. We recently demonstrated that zebrafish hematopoietic stem cells (HSCs) expressing jam1a were specifically localized along the renal collecting ducts in the adult kidney. Interestingly, most of HSCs invaded into the intracellular spaces of the epithelium in collecting ducts, suggesting that collecting ducts provide a specific microenvironment for HSCs. In order to identify niche factors in collecting ducts, we performed microarray analysis in collecting ducts isolated from the Tg(jam1a:EGFP) zebrafish kidney.
Project description:To investigate the specific role of Foxp1 in kidney tubular system, we specifically deleted Foxp1 expression in kidney distal nephrons and collecting ducts. We examined the effects of Foxp1 on IC differentiation and urine acidification. Chip-seq was used to identify Foxp1 target genes.
Project description:During development, distinct progenitors contribute to the nephrons versus the ureteric epithelium of the kidney. Indeed, previous pluripotent stem cell-derived models of kidney tissue either contain nephrons or pattern specifically to the ureteric epithelium. By reanalysing the transcriptional distinction between distal nephron and ureteric epithelium in human fetal kidney, we show here that while existing nephron-containing kidney organoids contain distal nephron epithelium and no ureteric epithelium, this distal nephron segment alone displays significant in vitro plasticity and can adopt a ureteric epithelial tip identity when isolated and cultured in defined conditions. “Induced” ureteric epithelium cultures can be cryopreserved, serially passaged without loss of identity and transitioned towards a collecting duct fate. Indeed, cultures harbouring loss-of-function mutations in PKHD1 recapitulate the cystic phenotype associated with autosomal recessive polycystic kidney disease.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)