Did you mean: pronephri
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Scientific Reports Oct 2023CLIC5 belongs to a family of ion channels with six members reported so far. In vertebrates, the CLIC5 gene encodes two different isoforms, CLIC5A and CLIC5B. In addition...
CLIC5 belongs to a family of ion channels with six members reported so far. In vertebrates, the CLIC5 gene encodes two different isoforms, CLIC5A and CLIC5B. In addition to its ion channel activity, there is evidence for further functions of CLIC5A, such as the remodeling of the actin cytoskeleton during the formation of a functional glomerulus in the vertebrate kidney. However, its specific role is still incompletely understood and a specific functional role for CLIC5B has not been described yet. Here we report our findings on the differential expression and functions of Clic5a and Clic5b during zebrafish kidney development. Whole-mount in situ hybridization studies revealed specific expression of clic5a in the eye and pronephric glomerulus, and clic5b is expressed in the gut, liver and the pronephric tubules. Clic5 immunostainings revealed that Clic5b is localized in the cilia. Whereas knockdown of Clic5a resulted in leakiness of the glomerular filtration barrier, Clic5b deficient embryos displayed defective ciliogenesis, leading to ciliopathy-associated phenotypes such as ventral body curvature, otolith deposition defects, altered left-right asymmetry and formation of hydrocephalus and pronephric cysts. In addition, Clic5 deficiency resulted in dysregulation of cilia-dependent Wnt signalling pathway components. Mechanistically, we identified a Clic5-dependent activation of the membrane-cytoskeletal linker proteins Ezrin/Radixin/Moesin (ERM) in the pronephric tubules of zebrafish. In conclusion, our in vivo data demonstrates a novel role for Clic5 in regulating essential ciliary functions and identified Clic5 as a positive regulator of ERM phosphorylation.
Topics: Animals; Actin Cytoskeleton; Chloride Channels; Chlorides; Cilia; Kidney Glomerulus; Microfilament Proteins; Zebrafish
PubMed: 37848494
DOI: 10.1038/s41598-023-44235-y -
Scientific Reports Nov 2023The transcription factor Six2 plays a crucial role in maintaining self-renewing nephron progenitor cap mesenchyme (CM) during metanephric kidney development. In mouse...
The transcription factor Six2 plays a crucial role in maintaining self-renewing nephron progenitor cap mesenchyme (CM) during metanephric kidney development. In mouse and human, expression at single-cell resolution has detected Six2 in cells as they leave the CM pool and differentiate. The role Six2 may play in these cells as they differentiate remains unknown. Here, we took advantage of the zebrafish pronephric kidney which forms directly from intermediate mesoderm to test six2b function during pronephric tubule development and differentiation. Expression of six2b during early zebrafish development was consistent with a role in pronephros formation. Using morpholino knock-down and CRISPR/Cas9 mutagenesis, we show a functional role for six2b in the development of proximal elements of the pronephros. By 48 h post-fertilization, six2b morphants and mutants showed disrupted pronephric tubule morphogenesis. We observed a lower-than-expected frequency of phenotypes in six2b stable genetic mutants suggesting compensation. Supporting this, we detected increased expression of six2a in six2b stable mutant embryos. To further confirm six2b function, F crispant embryos were analyzed and displayed similar phenotypes as morphants and stable mutants. Together our data suggests a conserved role for Six2 during nephrogenesis and a role in the morphogenesis of the proximal tubule.
Topics: Animals; Humans; Mice; Morphogenesis; Nephrons; Pronephros; Zebrafish; Zebrafish Proteins
PubMed: 37952044
DOI: 10.1038/s41598-023-47046-3 -
Ecotoxicology and Environmental Safety Jul 2023Gold nanoparticles (AuNPs) are widely used in biomedicine and their specific properties including, size, geometrics, and surface coating, will affect their fate and...
Gold nanoparticles (AuNPs) are widely used in biomedicine and their specific properties including, size, geometrics, and surface coating, will affect their fate and behaviour in biological systems. These properties are well studied for their intended biological targets, but there is a lack of understanding on the mechanisms by which AuNPs interact in non-target organisms when they enter the environment. We investigated the effects of size and surface chemistry of AuNPs on their bioavailability, tissue distribution and potential toxicity using zebrafish (Danio rerio) as an experimental model. Larval zebrafish were exposed to fluorescently tagged AuNPs of different sizes (10-100 nm) and surface modifications (TNFα, NHS/PAMAM and PEG), and uptake, tissue distribution and depuration rates were measured using selective-plane illumination microscopy (SPIM). The gut and pronephric tubules were found to contain detectable levels of AuNPs, and the concentration-dependent accumulation was related to the particle size. Surface addition of PEG and TNFα appeared to enhance particle accumulation in the pronephric tubules compared to uncoated particles. Depuration studies showed a gradual removal of particles from the gut and pronephric tubules, although fluorescence indicating the presence of the AuNPs remained in the pronephros 96 h after exposure. Toxicity assessment using two transgenic zebrafish reporter lines, however, revealed no AuNP-related renal injury or cellular oxidative stress. Collectively, our data show that AuNPs used in medical applications across the size range 40-80 nm, are bioavailable to larval zebrafish and some may persist in renal tissue, although their presence did not result in measurable toxicity with respect to pronephric organ function or cellular oxidative stress for short term exposures.
Topics: Animals; Zebrafish; Gold; Metal Nanoparticles; Tumor Necrosis Factor-alpha; Tissue Distribution; Biological Availability; Particle Size
PubMed: 37269610
DOI: 10.1016/j.ecoenv.2023.115019 -
Scientific Reports Oct 2023The nephron, functional unit of the vertebrate kidney, is specialized in metabolic wastes excretion and body fluids osmoregulation. Given the high evolutionary...
The nephron, functional unit of the vertebrate kidney, is specialized in metabolic wastes excretion and body fluids osmoregulation. Given the high evolutionary conservation of gene expression and segmentation patterning between mammalian and amphibian nephrons, the Xenopus laevis pronephric kidney offers a simplified model for studying nephrogenesis. The Lhx1 transcription factor plays several roles during embryogenesis, regulating target genes expression by forming multiprotein complexes with LIM binding protein 1 (Ldb1). However, few Lhx1-Ldb1 cofactors have been identified for kidney organogenesis. By tandem- affinity purification from kidney-induced Xenopus animal caps, we identified single-stranded DNA binding protein 2 (Ssbp2) interacts with the Ldb1-Lhx1 complex. Ssbp2 is expressed in the Xenopus pronephros, and knockdown prevents normal morphogenesis and differentiation of the glomus and the convoluted renal tubules. We demonstrate a role for a member of the Ssbp family in kidney organogenesis and provide evidence of a fundamental function for the Ldb1-Lhx1-Ssbp transcriptional complexes in embryonic development.
Topics: Animals; Xenopus laevis; LIM-Homeodomain Proteins; Gene Expression Regulation, Developmental; Transcription Factors; Kidney; Embryonic Development; Morphogenesis; Pronephros; Xenopus Proteins; Mammals
PubMed: 37794075
DOI: 10.1038/s41598-023-43662-1 -
BioRxiv : the Preprint Server For... Sep 2023Developmental studies have revealed the importance of the transcription factor Hand2 in cardiac development. Hand2 promotes cardiac progenitor differentiation and...
Developmental studies have revealed the importance of the transcription factor Hand2 in cardiac development. Hand2 promotes cardiac progenitor differentiation and epithelial maturation, while repressing other tissue types. The mechanisms underlying the promotion of cardiac fates are far better understood than those underlying the repression of alternative fates. Here, we assess Hand2-dependent changes in gene expression and chromatin remodeling in cardiac progenitors of zebrafish embryos. Cell-type specific transcriptome analysis shows a dual function for Hand2 in activation of cardiac differentiation genes and repression of pronephric pathways. We identify functional regulatory elements whose chromatin accessibility are increased in mutant cells. These regulatory elements associate with non-cardiac gene expression, and drive reporter gene expression in tissues associated with Hand2-repressed genes. We find that functional Hand2 is sufficient to reduce non-cardiac reporter expression in cardiac lineages. Taken together, our data support a model of Hand2-dependent coordination of transcriptional programs, not only through transcriptional activation of cardiac and epithelial maturation genes, but also through repressive chromatin remodeling at the DNA regulatory elements of non-cardiac genes.
PubMed: 37790542
DOI: 10.1101/2023.09.23.559156 -
International Journal of Molecular... Mar 2024Mutations of coding for polycystin-1 (PC1) account for most cases of autosomal-dominant polycystic kidney disease (ADPKD). The extracellular region of PC1 contains many...
Mutations of coding for polycystin-1 (PC1) account for most cases of autosomal-dominant polycystic kidney disease (ADPKD). The extracellular region of PC1 contains many evolutionarily conserved domains for ligand interactions. Among these are the leucine-rich repeats (LRRs) in the far N-terminus of PC1. Using zebrafish () as an in vivo model system, we explored the role of LRRs in the function of PC1. Zebrafish expresses two human paralogs, and . Knockdown of both genes in zebrafish by morpholino antisense oligonucleotides produced phenotypes of dorsal-axis curvature and pronephric cyst formation. We found that overexpression of LRRs suppressed both phenotypes in -morphant zebrafish. Purified recombinant LRR domain inhibited proliferation of HEK cells in culture and interacted with the heterotrimeric basement membrane protein laminin-511 (α5β1γ1) in vitro. Mutations of amino acid residues in LRRs structurally predicted to bind laminin-511 disrupted LRR-laminin interaction in vitro and neutralized the ability of LRRs to inhibit cell proliferation and cystogenesis. Our data support the hypothesis that the extracellular region of PC1 plays a role in modulating PC1 interaction with the extracellular matrix and contributes to cystogenesis of PC1 deficiency.
Topics: Animals; Humans; Polycystic Kidney, Autosomal Dominant; Zebrafish; Leucine; TRPP Cation Channels; Polycystic Kidney Diseases; Laminin; Kidney
PubMed: 38474131
DOI: 10.3390/ijms25052886