scholarly journals Multiomic identification of factors associated with progression to cystic kidney disease in mice with nephron Ift88 disruption

2021 ◽  
Author(s):  
Chunyan Hu ◽  
Katherine Beebe ◽  
Edgar J Hernandez ◽  
Jose M Lazaro-Guevara ◽  
Monica P Revelo ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Kidney Disease ◽  
Primary Cilia ◽  
Gene Mutations ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Factors Associated ◽  
Lipidomic Analysis ◽  
Renal Histology ◽  
Chain Acyl

Ift88 gene mutations cause primary cilia loss and polycystic kidney disease (PKD) in mice. Nephron Ift88 knockout (KO) at 2 months postnatal does not affect renal histology at 4 months postnatal and causes PKD only in males by 11 months postnatal. To identify factors associated with PKD development, kidneys from 4-month-old male and female control and Ift88 KO mice underwent transcriptomic, proteomic, western, metabolomic and lipidomic analysis. mRNAs involved in extracellular matrix (ECM) synthesis and degradation were selectively upregulated in male KO mice. Proteomic analysis was insufficiently sensitive to detect most ECM components, while western analysis paradoxically revealed reduced fibronectin and collagen I in male KO mice. Only male KO mice upregulated mRNAs encoding fibrinogen subunits and receptors for VEGF and PDGF; Per2, Per3 and Nrld2 clock mRNAs were selectively decreased in male KO mice. Proteomic, metabolomic and lipidomic analysis detected a relative (vs same sex control) decrease in factors involved in fatty acid ß-oxidation in female KO, while increased or unchanged levels in male KO, mice including medium chain acyl-CoA dehydrogenase, 3-hydroxybutyrate, and acylcarnitine. Three putative mRNA biomarkers of cystogenesis in male Ift88 KO mice (similar control levels between sexes and uniquely altered by KO in males) were identified, including high levels (Fga and Sdf2l1) and low levels (Banp) in male KO mice. These findings suggest that relative alterations in renal ECM metabolism, fatty acid ß-oxidation, and other pathways precede cystogenesis in Ift88 KO mice. In addition, potential novel biomarkers of cystogenesis in Ift88 KO mice have been identified.

Molecular genetics of renal ciliopathies

2021 ◽  
Author(s):  
Miguel Barroso-Gil ◽  
Eric Olinger ◽  
John A. Sayer
Keyword(s):  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Primary Cilia ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Renal Tubules ◽  
Polycystic Kidney ◽  
Inherited Disorders ◽  
Disease Phenotypes ◽  
Renal Histology

Renal ciliopathies are a heterogenous group of inherited disorders leading to an array of phenotypes that include cystic kidney disease and renal interstitial fibrosis leading to progressive chronic kidney disease and end-stage kidney disease. The renal tubules are lined with epithelial cells that possess primary cilia that project into the lumen and act as sensory and signalling organelles. Mutations in genes encoding ciliary proteins involved in the structure and function of primary cilia cause ciliopathy syndromes and affect many organ systems including the kidney. Recognised disease phenotypes associated with primary ciliopathies that have a strong renal component include autosomal dominant and recessive polycystic kidney disease and their various mimics, including atypical polycystic kidney disease and nephronophthisis. The molecular investigation of inherited renal ciliopathies often allows a precise diagnosis to be reached where renal histology and other investigations have been unhelpful and can help in determining kidney prognosis. With increasing molecular insights, it is now apparent that renal ciliopathies form a continuum of clinical phenotypes with disease entities that have been classically described as dominant or recessive at both extremes of the spectrum. Gene-dosage effects, hypomorphic alleles, modifier genes and digenic inheritance further contribute to the genetic complexity of these disorders. This review will focus on recent molecular genetic advances in the renal ciliopathy field with a focus on cystic kidney disease phenotypes and the genotypes that lead to them. We discuss recent novel insights into underlying disease mechanisms of renal ciliopathies that might be amenable to therapeutic intervention.

scholarly journals Nephrocystin-3 is required for ciliary function in zebrafish embryos

2010 ◽  
Vol 299 (1) ◽  
pp. F55-F62 ◽  
Author(s):  
Weibin Zhou ◽  
Julie Dai ◽  
Massimo Attanasio ◽  
Friedhelm Hildebrandt
Keyword(s):  
Kidney Disease ◽  
Positional Cloning ◽  
Primary Cilia ◽  
Kidney Diseases ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Zebrafish Embryos ◽  
Convergent Extension ◽  
Renal Cystic Disease ◽  
Ciliary Function

Nephronophthisis (NPHP) is the most frequent genetic cause of end-stage renal failure in the first three decades of life. It is characterized primarily by renal cysts with extrarenal involvements of the eye and brain. Ten recessive genes responsible for NPHP have been identified by positional cloning. This discovery supported a unifying theory of renal cystic disease, which states that all proteins mutated in cystic kidney diseases of human, mice, or zebrafish are expressed in primary cilia of renal epithelial cells. Mutations in nephrocystin-3 (NPHP3) are the cause of human nephronophthisis type 3 and polycystic kidney disease (pcy) mouse mutants. To study the functional role of NPHP3 in normal embryonic development and in the pathogenesis of cystic kidney disease, we characterized the zebrafish ortholog nphp3 by morpholino oligo (MO)-mediated knockdown. When nphp3 function was suppressed by either of the two MOs blocking the translation of the protein or the splicing of mRNA, zebrafish embryos displayed hydrocephalus and pronephric cysts. Knockdown of nphp3 also led to situs inversus phenotypes due to defective cilia at Kupffer's vesicle. We showed that nphp3 genetically interacts with nphp2/inversin and human NPHP3 localizes to primary cilia in Madin-Darby canine kidney cells. Like nphp2/inversin, nphp3 knockdown affected morphogenic cell movement during gastrulation, suggesting nphp3 is essential to regulate convergent extension. Thus nphp3, cooperating with nphp2/inversin, plays an essential role related to ciliary function, and the knockdown provides an animal model that may be used for studies of the pathogenesis and therapy for this disease.

scholarly journals Notch signaling regulates Akap12 expression and primary cilia length during renal tubule morphogenesis

2019 ◽  
Author(s):  
Malini Mukherjee ◽  
Ishara Ratnayake ◽  
Madhusudhana Janga ◽  
Eric Fogarty ◽  
Shania Scheidt ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Notch Signaling ◽  
Primary Cilia ◽  
Renal Tubule ◽  
Ectopic Expression ◽  
Clinical Manifestations ◽  
Alagille Syndrome ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Cystic Kidneys

AbstractAlagille syndrome patients present with loss of function mutations in either JAG1 or NOTCH2. About 40-50% of patients have kidney abnormalities, with multi-cystic, dysplastic kidneys being one of the more frequent kidney defects. Additionally, gain-of-function mutations in NOTCH2 are associated with cystic kidneys in Hajdu-Cheney syndrome patients. Conditional inactivation of Notch1, Notch2, or RBPJ within the nephrogenic lineage impairs nephrogenesis and produces proximal tubule cysts in mice. How perturbations in Notch signaling cause renal tubular cysts remains unclear. Here we have determined that inhibition of Notch signaling in the kidney increases Akap12 expression. Ectopic expression of Akap12 in renal epithelia results in abnormally long primary cilia similar to those observed in Notch-signal-deficiency. Both loss of Notch signaling and elevated Akap12 expression disrupt the ability of renal epithelial cells to form spherical structures with a single lumen when grown embedded in matrix. We conclude that Notch signaling regulates Akap12 expression to ensure normal primary cilia length and renal epithelial morphogenesis, and suggest that diseases associated with defective Notch signaling, such as Alagille syndrome, maybe mechanistically related to ciliopathies.Translational StatementThe current study examines how a reduction in Notch signaling results in abnormal renal tubule formation, as occurs in Alagille Syndrome patients with mutations in JAG1 or NOTCH2. The finding that reduced Notch signaling results in abnormally long cilia is suggestive that some of the clinical manifestations in Alagille Syndrome, such as small cystic kidneys, may originate due to defective cilia function. Linking Notch to primary cilia also opens up the possibility that coinheritance of mutations in ciliopathy genes along with a mutation in JAG1 or NOTCH2 may enhance the severity of the clinical phenotypes such as cystic kidney disease and may explain the variable occurrence and onset of kidney disease among Alagille Syndrome patients.

scholarly journals Drug and siRNA screens identify ROCK2 as a therapeutic target for ciliopathies

2020 ◽  
Author(s):  
Alice V. R. Lake ◽  
Claire E. L. Smith ◽  
Subaashini Natarajan ◽  
Basudha Basu ◽  
Sunayna K. Best ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Primary Cilia ◽  
Therapeutic Interventions ◽  
Cystic Kidney Disease ◽  
Pharmacological Intervention ◽  
Cystic Kidney ◽  
Rock Inhibitor ◽  
Positive Effects ◽  
Cilia Formation ◽  
And Function

AbstractPrimary cilia are microtubule-based organelles that act as cellular antennae to mediate vertebrate development and growth factor signalling. Defects in primary cilia result in a group of inherited developmental conditions known as ciliopathies. Ciliopathies often present with cystic kidney disease, a major cause of early renal failure that requires renal replacement therapies. Currently, only one drug, Tolvaptan, is licensed to slow the decline of renal function for the ciliopathy polycystic kidney disease. Novel therapeutic interventions for these conditions remain a pressing clinical need.We screened clinical development compounds for positive effects on cilia formation and function and identified fasudil hydrochloride as the top hit. Fasudil is a generic, off-patent drug that is a potent but broadly selective Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor. In a parallel whole genome siRNA-based reverse genetics phenotypic screen of positive modulators of cilia formation, we identified ROCK2 as the target molecule. We demonstrate that ROCK2 is a key mediator of cilium formation and function through effects on actin cytoskeleton remodelling. Our results indicate that specific ROCK2 inhibitors such as belumosudil (KD-025) could be repurposed for pharmacological intervention in cystic kidney disease. We propose that ROCK2 inhibition represents a novel, disease-modifying therapeutic approach for heterogeneous ciliopathies.

scholarly journals Deletion of IFT20 in the mouse kidney causes misorientation of the mitotic spindle and cystic kidney disease

2008 ◽  
Vol 183 (3) ◽  
pp. 377-384 ◽  
Author(s):  
Julie A. Jonassen ◽  
Jovenal San Agustin ◽  
John A. Follit ◽  
Gregory J. Pazour
Keyword(s):  
Kidney Disease ◽  
Primary Cilia ◽  
Collecting Duct ◽  
Cyst Formation ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Duct Cells ◽  
Cell Proliferation And Differentiation ◽  
Cilia Formation ◽  
Collecting Duct Cells

Primary cilia project from the surface of most vertebrate cells and are thought to be sensory organelles. Defects in primary cilia lead to cystic kidney disease, although the ciliary mechanisms that promote and maintain normal renal function remain incompletely understood. In this work, we generated a floxed allele of the ciliary assembly gene Ift20. Deleting this gene specifically in kidney collecting duct cells prevents cilia formation and promotes rapid postnatal cystic expansion of the kidney. Dividing collecting duct cells in early stages of cyst formation fail to properly orient their mitotic spindles along the tubule, whereas nondividing cells improperly position their centrosomes. At later stages, cells lacking cilia have increased canonical Wnt signaling and increased rates of proliferation. Thus, IFT20 functions to couple extracellular events to cell proliferation and differentiation.

scholarly journals Autosomal recessive polycystic kidney disease and complex nephronophtisis medullary cystic disease

2008 ◽  
Vol 136 (Suppl. 4) ◽  
pp. 348-352
Author(s):  
Emilija Golubovic
Keyword(s):  
Kidney Disease ◽  
Mammalian Cells ◽  
Autosomal Recessive ◽  
Primary Cilia ◽  
Calcium Influx ◽  
Control Cell ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Cystic Disease ◽  
Renal Cystic Disease

Reseach during the past decade has led to the discovery that defects in some proteins that localize to primary cilia or the basal body are the main contributors to renal cyst development. Autosomal recessive polycystic disease and nephronophthisis-medullary cystic kidney disease are named ciliopathies. The cilium is a microtubule-based organelle that is found on most mammalian cells. Cilia-mediated hypothesis has evolved into the concept of cystogenesis, cilia bend by fluid initiate a calcium influx that prevents cyst formation. Cilia might sense stimuli in the cell enviroment and control cell polarity and mitosis. A new set of pathogenic mechanisms in renal cystic disease defined new therapeutic targets, control of intracellular calcium, inhibition of cAMP and down regulation cannonical Wnt signaling.

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