title: Deletion of ADP Ribosylation Factor-Like GTPase 13B Leads to Kidney Cysts.
abstract: The gene for ADP ribosylation factor-like GTPase 13B (Arl13b) encodes a small GTPase essential for cilia biogenesis in multiple model organisms. Inactivation of arl13b in zebrafish leads to a number of phenotypes indicative of defective cilia, including cystic kidneys. In mouse, null mutation in Arl13b results in severe patterning defects in the neural tube and defective Hedgehog signaling. Human mutations of ARL13B lead to Joubert syndrome, a ciliopathy. However, patients with mutated ARL13B do not develop kidney cysts. To investigate whether Arl13b has a role in ciliogenesis in mammalian kidney and whether loss of function of Arl13b leads to cystic kidneys in mammals, we generated a mouse model with kidney-specific conditional knockout of Arl13b Deletion of Arl13b in the distal nephron at the perinatal stage led to a cilia biogenesis defect and rapid kidney cyst formation. Additionally, we detected misregulation of multiple pathways in the cystic kidneys of this model. Moreover, valproic acid, a histone deacetylase inhibitor that we previously showed slows cyst progression in a mouse cystic kidney model with neonatal inactivation of Pkd1, inhibited the early rise of Wnt7a expression, ameliorated fibrosis, slowed cyst progression, and improved kidney function in the Arl13b mutant mouse. Finally, in rescue experiments in zebrafish, all ARL13B allele combinations identified in patients with Joubert syndrome provided residual Arl13b function, supporting the idea that the lack of cystic kidney phenotype in human patients with ARL13B mutations is explained by the hypomorphic nature of the mutations.
authors.affiliation: Departments of *Genetics and.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Xin
authors.initials: X
authors.lastname: Tian
authors.affiliation: Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Ming
authors.initials: M
authors.lastname: Ma
authors.affiliation: Departments of *Genetics and.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Jerman
authors.affiliation: Departments of *Genetics and.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Kong
authors.affiliation: Departments of *Genetics and.|Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Stefan
authors.initials: S
authors.lastname: Somlo
authors.affiliation: Departments of *Genetics and zhaoxia.sun@yale.edu.
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Sun
mesh_terms: D020727:ADP-Ribosylation Factors / Q000235:genetics*; D000015:Abnormalities, Multiple / Q000235:genetics*; D000818:Animals; D002531:Cerebellum / Q000002:abnormalities*; D005124:Eye Abnormalities / Q000235:genetics*; D017353:Gene Deletion; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000235:genetics*; D051379:Mice; D009154:Mutation; D012160:Retina / Q000002:abnormalities*; D015027:Zebrafish
chemical_list: C560093:Arl13b protein, mouse; D020727:ADP-Ribosylation Factors
keywords: polycystic kidney disease; renal fibrosis; signaling