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Patel, V. et al. Acute kidney injury and aberrant planar cell polarity induce cyst formation in mice lacking renal cilia. Hum. Mol. Genet. 17, 1578-1590

Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Human Molecular Genetics (Impact Factor: 6.39). 07/2008; 17(11):1578-90. DOI: 10.1093/hmg/ddn045
Source: PubMed

ABSTRACT

Polycystic kidney disease (PKD) is an inherited disorder that is characterized by the accumulation of cysts in the renal parenchyma and progressive decline in renal function. Recent studies suggest that PKD arises from abnormalities of the primary cilium. We have previously shown that kidney-specific inactivation of the ciliogenic gene Kif3a during embryonic development produces kidney cysts and renal failure. Here, we used tamoxifen-inducible, kidney-specific gene targeting to inactivate Kif3a in the postnatal mouse kidney. Kidney-specific inactivation of Kif3a in newborn mice resulted in the loss of primary cilia and produced kidney cysts primarily in the loops of Henle, whereas inactivation in adult mice did not lead to the rapid development of cysts despite a comparable loss of primary cilia. The age-dependence and locations of the cysts suggested that cyst formation required increased rates of cell proliferation. To test this possibility, we stimulated cell proliferation in the adult kidney by inducing acute kidney injury and tubular regeneration. Acute kidney injury induced cyst formation in adult Kif3a mutant mice. Analysis of pre-cystic tubules in Kif3a mutant mice showed that the loss of cilia did not stimulate cell proliferation but instead resulted in aberrant planar cell polarity as manifested by abnormalities in the orientation of cell division. We conclude that primary cilia are required for the maintenance of planar cell polarity in the mammalian kidney and that acute kidney injury exacerbates cystic disease.

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Available from: Vishal Patel, May 26, 2014
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    • "KAP3 has the location to associate with cargoes through small G proteins, whereas KIF3A/KIF3B bond to the MTs [23]. The homolog of KIF3 in sea urchin has been reported to be a heterotrimer composed of SpKRP85, SpKRP95 and SpKAP115 [24]–[26]. KIF3 is responsible for the formation and elongation of cilia along with the central pair of MTs [19]. OSM-3 functions in the anterograde transport of cargoes that can mediate sensory ciliary growth in sensory neurons and inner labial neurons [27]. "
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    ABSTRACT: Background Spermatogenesis represents the transformation process at the level of cellular development. KIF3A and KIF3B are believed to play some roles in the assembly and maintenance of flagella, intracellular transport of materials including organelles and proteins, and other unknown functions during this process. During spermatogenesis in Eriocheir sinensis, if the sperm shaping machinery is dependent on KIF3A and KIF3B remains unknown. Methodology/Principal Findings The cDNA of KIF3A and KIF3B were obtained by designing degenerate primers, 3′RACE, and 5′RACE. We detected the genetic presence of kif3a and kif3b in the heart, muscle, liver, gill, and testis of E. sinensis through RT-PCR. By western blot analysis, the protein presence of KIF3A and KIF3B in heart, muscle, gill, and testis reflected the content in protein level. Using in situ hybridization and immunofluorescence, we could track the dynamic location of KIF3A and KIF3B during different developmental phases of sperm. KIF3A and KIF3B were found surrounding the nucleus in early spermatids. In intermediate spermatids, these proteins expressed at high levels around the nucleus and extended to the final phase. During the nuclear shaping period, KIF3A and KIF3B reached their maximum in the late spermatids and were located around the nucleus and concentrated in the acrosome to some extent. Conclusions/Significance Our results revealed that KIF3A and KIF3B were involved in the nuclear and cellular morphogenesis at the levels of mRNA and protein. These proteins can potentially facilitate the intracellular transport of organelles, proteins, and other cargoes. The results represent the functions of KIF3A and KIF3B in the spermatogenesis of Crustacea and clarify phylogenetic relationships among the Decapoda.
    Full-text · Article · May 2014 · PLoS ONE
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    • "The animal protocols were approved by Yale Animal Resources Center and Institutional Animal Care and Use Committee regulations . Pkd1 flox/flox mice were crossed with Pkd1 flox/+ :Pkhd1-Cre mice to generate Pkd1 flox/flox :Pkhd1-Cre mice as described previously [8] [19]. Pkd1 flox/flox :Pkhd1-Cre kidneys developed a minimal cystic lesions from post-natal (P) day 10 (P10) onward and progressed to massive cystic phenotype at P24 in distal tubule and collecting duct segments. "
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    ABSTRACT: Cyst enlargement in autosomal dominant polycystic kidney disease (ADPKD) is associated with cAMP-activated proliferation of cyst-lining epithelial cells and transepithelial fluid secretion into the cyst lumen via cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel leading to renal failure for which no effective treatment is currently available. We previously reported that steviol retards Madin-Darby canine kidney (MDCK) cyst enlargement by inhibiting CFTR channel activity and promoting proteasomal-mediated CFTR degradation. It is imperative to examine the effect of steviol in animal models of ADPKD. Therefore, we examined the effect of steviol on renal cyst growth in an orthologous mouse model of human ADPKD (Pkd1flox/flox:Pkhd1-Cre). The results showed that daily treatment with both 200mg/kg BW of steviol and 1,000mg/kg BW of stevioside for 14 days markedly decreased kidney weight and cystic index in these mice. However, only steviol markedly reduced blood urea nitrogen and creatinine values. Steviol also reduced cell proliferation but had no effect on cell apoptosis. In addition, steviol suppressed CFTR and mTOR/S6K expression in renal cyst-lining epithelial cells. Interestingly, steviol was found to stimulate AMP-activated protein kinase (AMPK). Our findings indicate that steviol slows cyst progression in ADPKD mouse model, in part, through the activation of AMPK which subsequently inhibits CFTR chloride channel expression and inhibits renal epithelial cell proliferation via mTOR/S6K pathway. Most importantly, steviol could markedly improve kidney function in a mouse model of ADPKD. Steviol thus has potential application for further development as a therapeutic compound for the treatment of polycystic kidney disease.
    Full-text · Article · Feb 2014 · Biochemical pharmacology
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    • "Interestingly, several recent studies have suggested a connection between ciliary dysfunction and acute kidney injury (AKI). On one hand, the loss of cilia seems to sensitize renal ischemia–reperfusioninduced AKI and on the other, ischemic AKI can promote or accelerate PKD in mice with ciliary defects [8] [9] [10] [11] [12]. Despite these notable observations , it is unclear whether ciliary regulation is involved specifically in ischemia–reperfusion injury or in other types of AKI as well. "
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    ABSTRACT: In kidneys, each tubular epithelial cell contains a primary cilium that protrudes from the apical surface. Ciliary dysfunction was recently linked to acute kidney injury (AKI) following renal ischemia-reperfusion. Whether ciliary regulation is a general pathogenic mechanism in AKI remains unclear. Moreover, the ciliary change during AKI and its underlying mechanism are largely unknown. Here we examined the change of primary cilium and its role in tubular cell apoptosis and AKI induced by cisplatin, a chemotherapy agent with notable nephrotoxicity. In cultured human proximal tubular HK-2 epithelial cells, cilia became shorter during cisplatin treatment, followed by apoptosis. Knockdown of Kif3a or Polaris (cilia maintenance proteins) reduced cilia and increased apoptosis during cisplatin treatment. We further subcloned HK-2 cells and found that the clones with shorter cilia were more sensitive to cisplatin-induced apoptosis. Mechanistically, cilia-suppressed cells showed hyperphosphorylation or activation of ERK. Inhibition of ERK by U0126 preserved cilia during cisplatin treatment and protected against apoptosis in HK-2 cells. In C57BL/6 mice, U0126 prevented the loss of cilia from proximal tubules during cisplatin treatment and protected against AKI. U0126 up-regulated Polaris, but not Kif3a, in kidney tissues. It is suggested that ciliary regulation by ERK plays a role in cisplatin-induced tubular apoptosis and AKI.
    Full-text · Article · May 2013 · Biochimica et Biophysica Acta
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