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Pietrobon A, Stanford WL. Tuberous Sclerosis Complex Kidney Lesion Pathogenesis: A Developmental Perspective. J Am Soc Nephrol 2023; 34:1135-1149. [PMID: 37060140 PMCID: PMC10356159 DOI: 10.1681/asn.0000000000000146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/27/2023] [Indexed: 04/16/2023] Open
Abstract
The phenotypic diversity of tuberous sclerosis complex (TSC) kidney pathology is enigmatic. Despite a well-established monogenic etiology, an incomplete understanding of lesion pathogenesis persists. In this review, we explore the question: How do TSC kidney lesions arise? We appraise literature findings in the context of mutational timing and cell-of-origin. Through a developmental lens, we integrate the critical results from clinical studies, human specimens, and genetic animal models. We also review novel insights gleaned from emerging organoid and single-cell sequencing technologies. We present a new model of pathogenesis which posits a phenotypic continuum, whereby lesions arise by mutagenesis during development from variably timed second-hit events. This model can serve as a conceptual framework for testing hypotheses of TSC lesion pathogenesis, both in the kidney and in other affected tissues.
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Affiliation(s)
- Adam Pietrobon
- The Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
| | - William L. Stanford
- The Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, Ottawa, Ontario, Canada
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2
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Bissler JJ, Batchelor D, Kingswood JC. Progress in Tuberous Sclerosis Complex Renal Disease. Crit Rev Oncog 2023; 27:35-49. [PMID: 36734871 DOI: 10.1615/critrevoncog.2022042857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects both fetal development and postnatal tissue growth, resulting in altered brain structures and a tumor predisposition syndrome. Although every organ system is affected by the disease, kidney involvement is a leading cause of death in adults with TSC. Over the past decade, significant progress has been made in understanding the renal disease. This review focuses on the cystic and solid renal lesions in TSC, including their pathobiology and treatment.
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Affiliation(s)
- John J Bissler
- Department of Pediatrics, University of Tennessee Health Science Center and Le Bonheur Children's Hospital, Memphis, TN 38105; Children's Foundation Research Institute (CFRI), Le Bonheur Children's Hospital, Memphis, TN 38105; Pediatric Medicine Department, St. Jude Children's Research Hospital, Memphis, TN 38105
| | - Dinah Batchelor
- Johns Hopkins All Children's Hospital, St. Petersburg, FL 33702
| | - J Christopher Kingswood
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Centre, St. Georges University of London, London, United Kingdom
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3
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Mechanism of cystogenesis by Cd79a-driven, conditional mTOR activation in developing mouse nephrons. Sci Rep 2023; 13:508. [PMID: 36627370 PMCID: PMC9832032 DOI: 10.1038/s41598-023-27766-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 01/06/2023] [Indexed: 01/12/2023] Open
Abstract
Polycystic kidney disease (PKD) is a common genetic disorder arising from developmental and postnatal processes. Defects in primary cilia and their signaling (eg, mTOR) underlie the pathogenesis. However, how mTOR regulates tubular integrity remains unclear. The paucity of faithful models has limited our understanding of pathogenesis and, therefore, the refinement of therapeutic targets. To understand the role of mTOR in early cystogenesis, we studied an in-house mouse model, Cd79a-Cre;Tsc1ff. (Cd79a-Tsc1 KO hereafter), recapitulating human autosomal-dominant PKD histology. Cre-mediated Tsc1 depletion driven by the promoter for Cd79a, a known B-cell receptor, activated mTORC1 exclusively along the distal nephron from embryonic day 16 onward. Cysts appeared in the distal nephron at 1 weeks of age and mice developed definite PKD by 4 weeks. Cd79a-Tsc1 KO tubule cells proliferated at a rate comparable to controls after birth but continued to divide even after postnatal day 14 when tubulogenesis is normally completed. Apoptosis occurred only after 9 weeks. During postnatal days 7-11, pre-cystic Cd79a-Tsc1 KO tubule cells showed cilia elongation, aberrant cell intercalation, and mitotic division, suggesting that defective cell planar polarity (PCP) may underlie cystogenesis. mTORC1 was activated in a portion of cyst-lining cells and occasionally even when Tsc1 was not depleted, implying a non-autonomous mechanism. Our results indicate that mTORC1 overactivation in developing distal tubules impairs their postnatal narrowing by disrupting morphogenesis, which orients an actively proliferating cell toward the elongating axis. The interplay between mTOR and cilium signaling, which coordinate cell proliferation with PCP, may be essential for cystogenesis.
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4
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Karalis V, Donovan KE, Sahin M. Primary Cilia Dysfunction in Neurodevelopmental Disorders beyond Ciliopathies. J Dev Biol 2022; 10:54. [PMID: 36547476 PMCID: PMC9782889 DOI: 10.3390/jdb10040054] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/04/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Primary cilia are specialized, microtubule-based structures projecting from the surface of most mammalian cells. These organelles are thought to primarily act as signaling hubs and sensors, receiving and integrating extracellular cues. Several important signaling pathways are regulated through the primary cilium including Sonic Hedgehog (Shh) and Wnt signaling. Therefore, it is no surprise that mutated genes encoding defective proteins that affect primary cilia function or structure are responsible for a group of disorders collectively termed ciliopathies. The severe neurologic abnormalities observed in several ciliopathies have prompted examination of primary cilia structure and function in other brain disorders. Recently, neuronal primary cilia defects were observed in monogenic neurodevelopmental disorders that were not traditionally considered ciliopathies. The molecular mechanisms of how these genetic mutations cause primary cilia defects and how these defects contribute to the neurologic manifestations of these disorders remain poorly understood. In this review we will discuss monogenic neurodevelopmental disorders that exhibit cilia deficits and summarize findings from studies exploring the role of primary cilia in the brain to shed light into how these deficits could contribute to neurologic abnormalities.
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Affiliation(s)
- Vasiliki Karalis
- The Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- FM Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Kathleen E. Donovan
- The Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- FM Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Mustafa Sahin
- The Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- FM Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
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5
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Yin F, Wei Z, Chen F, Xin C, Chen Q. Molecular targets of primary cilia defects in cancer (Review). Int J Oncol 2022; 61:98. [DOI: 10.3892/ijo.2022.5388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/20/2022] [Indexed: 11/05/2022] Open
Affiliation(s)
- Fengying Yin
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Zihao Wei
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Fangman Chen
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Chuan Xin
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Qianming Chen
- Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
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6
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Kumar P, Zadjali F, Yao Y, Bissler JJ. Renal cystic disease in tuberous sclerosis complex. Exp Biol Med (Maywood) 2021; 246:2111-2117. [PMID: 34488473 DOI: 10.1177/15353702211038378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is associated with TSC1 or TSC2 gene mutations resulting in hyperactivation of the mTORC1 pathway. This mTORC1 activation is associated with abnormal tissue development and proliferation such that in the kidney there are both solid tumors and cystic lesions. This review summarizes recent advances in tuberous sclerosis complex nephrology and focuses on the genetics and cell biology of tuberous sclerosis complex renal disease, highlighting a role of extracellular vesicles and the innate immune system in disease pathogenesis.
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Affiliation(s)
- Prashant Kumar
- Department of Pediatrics, University of Tennessee Health Science Center and Le Bonheur Children's Hospital, Memphis, TN 38105, USA.,Children's Foundation Research Institute (CFRI), Le Bonheur Children's Hospital, Memphis, TN 38105, USA
| | - Fahad Zadjali
- Department of Pediatrics, University of Tennessee Health Science Center and Le Bonheur Children's Hospital, Memphis, TN 38105, USA.,Children's Foundation Research Institute (CFRI), Le Bonheur Children's Hospital, Memphis, TN 38105, USA.,Department of Clinical Biochemistry, College of Medicine & Health Sciences, Sultan Qaboos University, Muscat, PC 123, Oman
| | - Ying Yao
- Department of Pediatrics, University of Tennessee Health Science Center and Le Bonheur Children's Hospital, Memphis, TN 38105, USA.,Children's Foundation Research Institute (CFRI), Le Bonheur Children's Hospital, Memphis, TN 38105, USA
| | - John J Bissler
- Department of Pediatrics, University of Tennessee Health Science Center and Le Bonheur Children's Hospital, Memphis, TN 38105, USA.,Children's Foundation Research Institute (CFRI), Le Bonheur Children's Hospital, Memphis, TN 38105, USA.,Pediatric Medicine Department, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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7
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Klofas LK, Short BP, Zhou C, Carson RP. Prevention of premature death and seizures in a Depdc5 mouse epilepsy model through inhibition of mTORC1. Hum Mol Genet 2021; 29:1365-1377. [PMID: 32280987 DOI: 10.1093/hmg/ddaa068] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
Mutations in DEP domain containing 5 (DEPDC5) are increasingly appreciated as one of the most common causes of inherited focal epilepsy. Epilepsies due to DEPDC5 mutations are often associated with brain malformations, tend to be drug-resistant, and have been linked to an increased risk of sudden unexplained death in epilepsy (SUDEP). Generation of epilepsy models to define mechanisms of epileptogenesis remains vital for future therapies. Here, we describe a novel mouse model of Depdc5 deficiency with a severe epilepsy phenotype, generated by conditional deletion of Depdc5 in dorsal telencephalic neuroprogenitor cells. In contrast to control and heterozygous mice, Depdc5-Emx1-Cre conditional knockout (CKO) mice demonstrated macrocephaly, spontaneous seizures and premature death. Consistent with increased mTORC1 activation, targeted neurons were enlarged and both neurons and astrocytes demonstrated increased S6 phosphorylation. Electrophysiologic characterization of miniature inhibitory post-synaptic currents in excitatory neurons was consistent with impaired post-synaptic response to GABAergic input, suggesting a potential mechanism for neuronal hyperexcitability. mTORC1 inhibition with rapamycin significantly improved survival of CKO animals and prevented observed seizures, including for up to 40 days following rapamycin withdrawal. These data not only support a primary role for mTORC1 hyperactivation in epilepsy following homozygous loss of Depdc5, but also suggest a developmental window for treatment which may have a durable benefit for some time even after withdrawal.
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Affiliation(s)
- Lindsay K Klofas
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Brittany P Short
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Robert P Carson
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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8
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Di Nardo A, Lenoël I, Winden KD, Rühmkorf A, Modi ME, Barrett L, Ercan-Herbst E, Venugopal P, Behne R, Lopes CAM, Kleiman RJ, Bettencourt-Dias M, Sahin M. Phenotypic Screen with TSC-Deficient Neurons Reveals Heat-Shock Machinery as a Druggable Pathway for mTORC1 and Reduced Cilia. Cell Rep 2021; 31:107780. [PMID: 32579942 PMCID: PMC7381997 DOI: 10.1016/j.celrep.2020.107780] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 04/20/2020] [Accepted: 05/27/2020] [Indexed: 02/08/2023] Open
Abstract
Tuberous sclerosis complex (TSC) is a neurogenetic disorder that leads to elevated mechanistic targeting of rapamycin complex 1 (mTORC1) activity. Cilia can be affected by mTORC1 signaling, and ciliary deficits are associated with neurodevelopmental disorders. Here, we examine whether neuronal cilia are affected in TSC. We show that cortical tubers from TSC patients and mutant mouse brains have fewer cilia. Using high-content image-based assays, we demonstrate that mTORC1 activity inversely correlates with ciliation in TSC1/2-deficientneurons.To investigate the mechanistic relationship between mTORC1 and cilia, we perform a phenotypic screen for mTORC1 inhibitors with TSC1/2-deficient neurons. We identify inhibitors ofthe heat shock protein 90 (Hsp90) that suppress mTORC1 through regulation of phosphatidylinositol 3-kinase (PI3K)/Akt signaling. Pharmacological inhibition of Hsp90 rescues ciliation through downregulation of Hsp27. Our study uncovers the heat-shock machinery as a druggable signaling node to restore mTORC1 activity and cilia due to loss of TSC1/2, and it provides broadly applicable platforms for studying TSC-related neuronal dysfunction. Di Nardo et al. find that cortical tubers from TSC patients and mutant mouse brains have fewer cilia. An image-based screening of mTORC1 activity in TSC1/2-deficient neurons leads to the identification of the heat-shock machinery as a druggable signaling node to restore mTORC1 activity and cilia.
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Affiliation(s)
- Alessia Di Nardo
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Isadora Lenoël
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Kellen D Winden
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Alina Rühmkorf
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Meera E Modi
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Lee Barrett
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ebru Ercan-Herbst
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Pooja Venugopal
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Robert Behne
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Carla A M Lopes
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, Oeiras 2780-156, Portugal
| | - Robin J Kleiman
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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9
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Zhu P, Qiu Q, Harris PC, Xu X, Lin X. mtor Haploinsufficiency Ameliorates Renal Cysts and Cilia Abnormality in Adult Zebrafish tmem67 Mutants. J Am Soc Nephrol 2021; 32:822-836. [PMID: 33574160 PMCID: PMC8017545 DOI: 10.1681/asn.2020070991] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/21/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Although zebrafish embryos have been used to study ciliogenesis and model polycystic kidney disease (PKD), adult zebrafish remain unexplored. METHODS Transcription activator-like effector nucleases (TALEN) technology was used to generate mutant for tmem67, the homolog of the mammalian causative gene for Meckel syndrome type 3 (MKS3). Classic 2D and optical-clearing 3D imaging of an isolated adult zebrafish kidney were used to examine cystic and ciliary phenotypes. A hypomorphic mtor strain or rapamycin was used to inhibit mTOR activity. RESULTS Adult tmem67 zebrafish developed progressive mesonephric cysts that share conserved features of mammalian cystogenesis, including a switch of cyst origin with age and an increase in proliferation of cyst-lining epithelial cells. The mutants had shorter and fewer distal single cilia and greater numbers of multiciliated cells (MCCs). Absence of a single cilium preceded cystogenesis, and expansion of MCCs occurred after pronephric cyst formation and was inversely correlated with the severity of renal cysts in young adult zebrafish, suggesting a primary defect and an adaptive action, respectively. Finally, the mutants exhibited hyperactive mTOR signaling. mTOR inhibition ameliorated renal cysts in both the embryonic and adult zebrafish models; however, it only rescued ciliary abnormalities in the adult mutants. CONCLUSIONS Adult zebrafish tmem67 mutants offer a new vertebrate model for renal cystic diseases, in which cilia morphology can be analyzed at a single-nephron resolution and mTOR inhibition proves to be a candidate therapeutic strategy.
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Affiliation(s)
- Ping Zhu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| | - Qi Qiu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| | - Peter C. Harris
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota,Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota,Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| | - Xueying Lin
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
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10
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Reciprocal Regulation between Primary Cilia and mTORC1. Genes (Basel) 2020; 11:genes11060711. [PMID: 32604881 PMCID: PMC7349257 DOI: 10.3390/genes11060711] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 12/11/2022] Open
Abstract
In quiescent cells, primary cilia function as a mechanosensor that converts mechanic signals into chemical activities. This unique organelle plays a critical role in restricting mechanistic target of rapamycin complex 1 (mTORC1) signaling, which is essential for quiescent cells to maintain their quiescence. Multiple mechanisms have been identified that mediate the inhibitory effect of primary cilia on mTORC1 signaling. These mechanisms depend on several tumor suppressor proteins localized within the ciliary compartment, including liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK), polycystin-1, and polycystin-2. Conversely, changes in mTORC1 activity are able to affect ciliogenesis and stability indirectly through autophagy. In this review, we summarize recent advances in our understanding of the reciprocal regulation of mTORC1 and primary cilia.
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11
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Bonucci M, Kuperwasser N, Barbe S, Koka V, de Villeneuve D, Zhang C, Srivastava N, Jia X, Stokes MP, Bienaimé F, Verkarre V, Lopez JB, Jaulin F, Pontoglio M, Terzi F, Delaval B, Piel M, Pende M. mTOR and S6K1 drive polycystic kidney by the control of Afadin-dependent oriented cell division. Nat Commun 2020; 11:3200. [PMID: 32581239 PMCID: PMC7314806 DOI: 10.1038/s41467-020-16978-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 06/01/2020] [Indexed: 02/08/2023] Open
Abstract
mTOR activation is essential and sufficient to cause polycystic kidneys in Tuberous Sclerosis Complex (TSC) and other genetic disorders. In disease models, a sharp increase of proliferation and cyst formation correlates with a dramatic loss of oriented cell division (OCD). We find that OCD distortion is intrinsically due to S6 kinase 1 (S6K1) activation. The concomitant loss of S6K1 in Tsc1-mutant mice restores OCD but does not decrease hyperproliferation, leading to non-cystic harmonious hyper growth of kidneys. Mass spectrometry-based phosphoproteomics for S6K1 substrates revealed Afadin, a known component of cell-cell junctions required to couple intercellular adhesions and cortical cues to spindle orientation. Afadin is directly phosphorylated by S6K1 and abnormally decorates the apical surface of Tsc1-mutant cells with E-cadherin and α-catenin. Our data reveal that S6K1 hyperactivity alters centrosome positioning in mitotic cells, affecting oriented cell division and promoting kidney cysts in conditions of mTOR hyperactivity.
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Affiliation(s)
- Martina Bonucci
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Nicolas Kuperwasser
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Serena Barbe
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Vonda Koka
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Delphine de Villeneuve
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Chi Zhang
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Nishit Srivastava
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
| | - Xiaoying Jia
- Cell Signaling Technology INC, 3 Trask Lane, Danvers, MA, 01923, USA
| | - Matthew P Stokes
- Cell Signaling Technology INC, 3 Trask Lane, Danvers, MA, 01923, USA
| | - Frank Bienaimé
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Virginie Verkarre
- Université de Paris, PARCC, INSERM, Equipe Labellisée par la Ligue contre le Cancer, F-75015, Paris, France.,Assistance Publique-Hôpitaux de Paris (AP-HP centre), Hôpital Européen Georges Pompidou, Département d'anatomo-pathologie, F-75015, Paris, France
| | | | | | - Marco Pontoglio
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Fabiola Terzi
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France.,Inserm, U1151, Paris, F-75014, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Benedicte Delaval
- CRBM, CNRS, Univ. Montpellier, Centrosome, cilia and pathologies Lab, 1919 Route de Mende, 34293, Montpellier, France
| | - Matthieu Piel
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
| | - Mario Pende
- Institut Necker-Enfants Malades, 14 rue Maria Helena Vieira Da Silva, CS, 61431, Paris, France. .,Inserm, U1151, Paris, F-75014, France. .,Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
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12
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Bissler JJ, Zadjali F, Bridges D, Astrinidis A, Barone S, Yao Y, Redd JR, Siroky BJ, Wang Y, Finley JT, Rusiniak ME, Baumann H, Zahedi K, Gross KW, Soleimani M. Tuberous sclerosis complex exhibits a new renal cystogenic mechanism. Physiol Rep 2019; 7:e13983. [PMID: 30675765 PMCID: PMC6344348 DOI: 10.14814/phy2.13983] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 12/20/2018] [Indexed: 02/06/2023] Open
Abstract
Tuberous sclerosis complex (TSC) is a tumor predisposition syndrome with significant renal cystic and solid tumor disease. While the most common renal tumor in TSC, the angiomyolipoma, exhibits a loss of heterozygosity associated with disease, we have discovered that the renal cystic epithelium is composed of type A intercalated cells that have an intact Tsc gene that have been induced to exhibit Tsc-mutant disease phenotype. This mechanism appears to be different than that for ADPKD. The murine models described here closely resemble the human disease and both appear to be mTORC1 inhibitor responsive. The induction signaling driving cystogenesis may be mediated by extracellular vesicle trafficking.
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Affiliation(s)
- John J. Bissler
- Department of PediatricsUniversity of Tennessee Health Science Center and Le Bonheur Children's HospitalMemphisTennessee
- St. Jude Children's Research HospitalMemphisTennessee
| | - Fahad Zadjali
- Department of Clinical BiochemistryCollege of Medicine & Health SciencesSultan Qaboos UniversityMuscatOman
| | - Dave Bridges
- Department of Nutritional SciencesUniversity of Michigan School of Public HealthAnn ArborMichigan
| | - Aristotelis Astrinidis
- Department of PediatricsUniversity of Tennessee Health Science Center and Le Bonheur Children's HospitalMemphisTennessee
| | - Sharon Barone
- Departments of MedicineUniversity of Cincinnati College of MedicineCincinnatiOhio
- Center on Genetics of TransportUniversity of Cincinnati College of MedicineCincinnatiOhio
- Research ServicesVeterans Affairs Medical CenterCincinnatiOhio
| | - Ying Yao
- Department of PediatricsUniversity of Tennessee Health Science Center and Le Bonheur Children's HospitalMemphisTennessee
| | - JeAnna R. Redd
- Department of Nutritional SciencesUniversity of Michigan School of Public HealthAnn ArborMichigan
| | - Brian J. Siroky
- Department of PediatricsUniversity of Cincinnati College of MedicineCincinnatiOhio
| | - Yanqing Wang
- Department of Molecular and Cellular BiologyRoswell Park Cancer InstituteBuffaloNew York
| | - Joel T. Finley
- Department of PediatricsUniversity of Tennessee Health Science Center and Le Bonheur Children's HospitalMemphisTennessee
| | - Michael E. Rusiniak
- Department of Molecular and Cellular BiologyRoswell Park Cancer InstituteBuffaloNew York
| | - Heinz Baumann
- Department of Molecular and Cellular BiologyRoswell Park Cancer InstituteBuffaloNew York
| | - Kamyar Zahedi
- Departments of MedicineUniversity of Cincinnati College of MedicineCincinnatiOhio
- Center on Genetics of TransportUniversity of Cincinnati College of MedicineCincinnatiOhio
- Research ServicesVeterans Affairs Medical CenterCincinnatiOhio
| | - Kenneth W. Gross
- Department of Molecular and Cellular BiologyRoswell Park Cancer InstituteBuffaloNew York
| | - Manoocher Soleimani
- Departments of MedicineUniversity of Cincinnati College of MedicineCincinnatiOhio
- Center on Genetics of TransportUniversity of Cincinnati College of MedicineCincinnatiOhio
- Research ServicesVeterans Affairs Medical CenterCincinnatiOhio
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13
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Bissler JJ, Christopher Kingswood J. Renal manifestation of tuberous sclerosis complex. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:338-347. [PMID: 30307110 DOI: 10.1002/ajmg.c.31654] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/05/2018] [Accepted: 09/06/2018] [Indexed: 11/07/2022]
Abstract
Tuberous sclerosis complex (TSC) is a tumor predisposition syndrome with significant renal cystic and solid tumor disease. It commonly causes several types of cystic disease and benign tumors (angiomyolipomata) in the kidneys that can both lead to significant premature loss of glomerular filtration rate. The main risks of angiomyolipomata, severe bleeding, loss of renal function, and pulmonary lymphangioleiomyomatosis, can be ameliorated by active surveillance and preemptive therapy with mTOR inhibitors. The cystogenic mechanism may involve primary cilia, but also appears to also involve a majority of normal tubular cells and may be driven by a minority of cells with mutations inactivating both their TSC1 or TSC2 genes. Malignant tumors are rare.
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Affiliation(s)
- John J Bissler
- Department of Pediatrics, University of Tennessee Health Science Center and Le Bonheur Children's Hospital, Memphis, TN
- St. Jude Children's Research Hospital, Memphis, TN
| | - J Christopher Kingswood
- Cardiology Clinical Academic Group, Molecular and Clinical Sciences Research Centre, St. Georges University of London, London, United kingdom
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14
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Rosengren T, Larsen LJ, Pedersen LB, Christensen ST, Møller LB. TSC1 and TSC2 regulate cilia length and canonical Hedgehog signaling via different mechanisms. Cell Mol Life Sci 2018; 75:2663-2680. [PMID: 29396625 PMCID: PMC6003990 DOI: 10.1007/s00018-018-2761-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 01/03/2018] [Accepted: 01/24/2018] [Indexed: 01/22/2023]
Abstract
Primary cilia are sensory organelles that coordinate multiple cellular signaling pathways, including Hedgehog (HH), Wingless/Int (WNT) and Transforming Growth Factor-β (TGF-β) signaling. Similarly, primary cilia have been implicated in regulation of mTOR signaling, in which Tuberous Sclerosis Complex proteins 1 and 2 (TSC1/2) negatively regulate protein synthesis by inactivating the mTOR complex 1 (mTORC1) at energy limiting states. Here we report that TSC1 and TSC2 regulate Smoothened (SMO)-dependent HH signaling in mouse embryonic fibroblasts (MEFs). Reduced SMO-dependent expression of Gli1 was demonstrated in both Tsc1-/- and Tsc2-/- cells, and we found that Tsc1 is required for TGF-β induced phosphorylation of SMAD2/3 and subsequent expression of the HH signaling effector and transcription factor GLI2. Hedgehog signaling was restored in Tsc1-/- cells after exogenous expression of Gli2, whereas rapamycin restored HH signaling in Tsc2-/- cells. Furthermore, we observed that Tsc1-/- MEFs display significantly elongated cilia, whereas cilia in Tsc2-/- MEFs were shorter than normal. The elongated cilium phenotype of Tsc1-/- MEFs is likely due to increased mTORC1-dependent autophagic flux observed in these cells, as both the autophagic flux and the cilia length phenotype was restored by rapamycin. In addition, ciliary length control in Tsc1-/- MEFs was also influenced by reduced expression of Gli2, which compromised expression of Wnt5a that normally promotes cilia disassembly. In summary, our results support distinct functions of Tsc1 and Tsc2 in cellular signaling as the two genes affect ciliary length control and HH signaling via different mechanisms.
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Affiliation(s)
- Thomas Rosengren
- Applied Human Molecular Genetics, Clinical Genetic Clinic, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Gl. Landevej 7, 2600, Glostrup, Denmark
| | - Lasse Jonsgaard Larsen
- Applied Human Molecular Genetics, Clinical Genetic Clinic, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Gl. Landevej 7, 2600, Glostrup, Denmark
| | - Lotte Bang Pedersen
- Department of Biology, The August Krogh Building, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark
| | - Søren Tvorup Christensen
- Department of Biology, The August Krogh Building, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark
| | - Lisbeth Birk Møller
- Applied Human Molecular Genetics, Clinical Genetic Clinic, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Gl. Landevej 7, 2600, Glostrup, Denmark.
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15
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Oyerinde O, Buccine D, Treichel A, Hong C, Lee CCR, Moss J, Darling TN. Fibrous cephalic plaques in tuberous sclerosis complex. J Am Acad Dermatol 2017; 78:717-724. [PMID: 29258863 DOI: 10.1016/j.jaad.2017.12.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/01/2017] [Accepted: 12/10/2017] [Indexed: 12/29/2022]
Abstract
BACKGROUND Fibrous cephalic plaques (FCPs) stereotypically develop on the forehead of patients with tuberous sclerosis complex (TSC). They constitute a major feature for TSC diagnosis and may present before other TSC-related cutaneous hamartomas. OBJECTIVE To describe the clinical characteristics of FCPs in TSC. METHODS A total of 113 patients with TSC were enrolled in an observational cohort study. Retrospective analysis of medical records and skin photography was performed. FCPs were categorized by anatomic location and size. RESULTS FCPs were observed in 36% of patients (41 of 113). Of 62 total lesions, 58% were 1 to less than 5 cm, 13% were 5 cm or larger, and 29% were of unknown size mostly because of prior excision. The distribution of lesions was 39% on the forehead, 27% on the face (nonforehead), 3% on the neck, and 31% on the scalp. Fourteen patients had similar lesions less than 1 cm in diameter. Histopathologically, FCPs displayed dermal collagenosis, decreased elastic fibers, and features of angiofibromas or fibrofolliculomas. LIMITATIONS Men were under-represented because the cohort was enriched for patients with TSC with lymphangioleiomyomatosis, which occurs in adult women. CONCLUSION Two-fifths of FCPs presented on the forehead, with most of the remainder in other locations on the face and scalp. Better recognition of these lesions may lead to earlier diagnosis of TSC.
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Affiliation(s)
- Oyetewa Oyerinde
- Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; Department of Dermatology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Danielle Buccine
- Department of Dermatology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Alison Treichel
- Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; Department of Dermatology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Claire Hong
- Department of Dermatology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Chyi-Chia Richard Lee
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Joel Moss
- Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Thomas N Darling
- Department of Dermatology, Uniformed Services University of the Health Sciences, Bethesda, Maryland.
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16
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PI3K Signaling in Tissue Hyper-Proliferation: From Overgrowth Syndromes to Kidney Cysts. Cancers (Basel) 2017; 9:cancers9040030. [PMID: 28353628 PMCID: PMC5406705 DOI: 10.3390/cancers9040030] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 03/24/2017] [Accepted: 03/27/2017] [Indexed: 12/19/2022] Open
Abstract
The members of the PhosphoInositide-3 Kinase (PI3K) protein family are well-known regulators of proliferative signals. By the generation of lipid second messengers, they mediate the activation of AKT/PKB (AKT) and mammalian Target Of Rapamycin (mTOR) pathways. Although mutations in the PI3K/AKT/mTOR pathway are highly characterized in cancer, recent evidence indicates that alterations in the proliferative signals are major drivers of other diseases such as overgrowth disorders and polycystic kidney disease. In this review, we briefly summarize the role of the PI3K/AKT/mTOR pathway in cell proliferation by comparing the effect of alterations in PI3K enzymes in different tissues. In particular, we discuss the most recent findings on how the same pathway may lead to different biological effects, due to the convergence and cooperation of different signaling cascades.
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17
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Malicki JJ, Johnson CA. The Cilium: Cellular Antenna and Central Processing Unit. Trends Cell Biol 2017; 27:126-140. [PMID: 27634431 PMCID: PMC5278183 DOI: 10.1016/j.tcb.2016.08.002] [Citation(s) in RCA: 247] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 07/14/2016] [Accepted: 08/04/2016] [Indexed: 12/14/2022]
Abstract
Cilia mediate an astonishing diversity of processes. Recent advances provide unexpected insights into the regulatory mechanisms of cilium formation, and reveal diverse regulatory inputs that are related to the cell cycle, cytoskeleton, proteostasis, and cilia-mediated signaling itself. Ciliogenesis and cilia maintenance are regulated by reciprocal antagonistic or synergistic influences, often acting in parallel to each other. By receiving parallel inputs, cilia appear to integrate multiple signals into specific outputs and may have functions similar to logic gates of digital systems. Some combinations of input signals appear to impose higher hierarchical control related to the cell cycle. An integrated view of these regulatory inputs will be necessary to understand ciliogenesis and its wider relevance to human biology.
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Affiliation(s)
- Jarema J Malicki
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Western Bank Sheffield, S10 2TN, UK.
| | - Colin A Johnson
- Wellcome Trust Brenner Building, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Beckett Street, Leeds LS9 7TF, UK.
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18
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Sherpa RT, Atkinson KF, Ferreira VP, Nauli SM. RAPAMYCIN INCREASES LENGTH AND MECHANOSENSORY FUNCTION OF PRIMARY CILIA IN RENAL EPITHELIAL AND VASCULAR ENDOTHELIAL CELLS. INTERNATIONAL EDUCATION AND RESEARCH JOURNAL 2016; 2:91-97. [PMID: 28529994 PMCID: PMC5436805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Primary cilia arebiophysically-sensitive organelles responsible for sensing fluid-flow and transducing this stimulus into intracellular responses. Previous studies have shown that the primary cilia mediate flow-induced calcium influx, and sensitivity of cilia function to flow is correlated to cilia length. Cells with abnormal cilia length or function can lead to a host of diseases that are collectively termed as ciliopathies. Rapamycin, a potent inhibitor of mTOR (mammalian target of rapamycin), has been demonstrated to be a potential pharmacological agent against the aberrant mTOR signaling seen in ciliopathies such as polycystic kidney disease (PKD) and tuberous sclerosis complex (TSC). Here we look at the effects of rapamycin on ciliary length and function for the first time. Compared to controls, primary cilia in rapamycin-treated porcine renal epithelial and mouse vascular endothelial cells showed a significant increase in length. Graded increases in fluid-shear stress further indicates that rapamycin enhances cilia sensitivity to fluid flow. Treatment with rapamycin led to G0 arrest in porcine epithelial cells while no significant change in cell cycle were observed in rapamycin-treated mouse epithelial or endothelial cells, indicating a species-specific effect of rapamycin. Given the previousin vitro and in vivo studies establishing rapamycin as a potential therapeutic agent for ciliopathies, such as PKD and TSC, our studies show that rapamycin enhances ciliary function and sensitivity to fluid flow. The results of our studies suggest a potential ciliotherapeutic effect of rapamycin.
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Affiliation(s)
- Rinzhin T. Sherpa
- Department of Biomedical & Pharmaceutical Sciences, Chapman University, Irvine, CA
| | - Kimberly F. Atkinson
- Department of Biomedical & Pharmaceutical Sciences, Chapman University, Irvine, CA
| | - Viviana P. Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH
| | - Surya M. Nauli
- Department of Biomedical & Pharmaceutical Sciences, Chapman University, Irvine, CA
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19
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Nikopoulos K, Farinelli P, Giangreco B, Tsika C, Royer-Bertrand B, Mbefo M, Bedoni N, Kjellström U, El Zaoui I, Di Gioia S, Balzano S, Cisarova K, Messina A, Decembrini S, Plainis S, Blazaki S, Khan M, Micheal S, Boldt K, Ueffing M, Moulin A, Cremers F, Roepman R, Arsenijevic Y, Tsilimbaris M, Andréasson S, Rivolta C. Mutations in CEP78 Cause Cone-Rod Dystrophy and Hearing Loss Associated with Primary-Cilia Defects. Am J Hum Genet 2016; 99:770-776. [PMID: 27588451 DOI: 10.1016/j.ajhg.2016.07.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/07/2016] [Indexed: 02/08/2023] Open
Abstract
Cone-rod degeneration (CRD) belongs to the disease spectrum of retinal degenerations, a group of hereditary disorders characterized by an extreme clinical and genetic heterogeneity. It mainly differentiates from other retinal dystrophies, and in particular from the more frequent disease retinitis pigmentosa, because cone photoreceptors degenerate at a higher rate than rod photoreceptors, causing severe deficiency of central vision. After exome analysis of a cohort of individuals with CRD, we identified biallelic mutations in the orphan gene CEP78 in three subjects from two families: one from Greece and another from Sweden. The Greek subject, from the island of Crete, was homozygous for the c.499+1G>T (IVS3+1G>T) mutation in intron 3. The Swedish subjects, two siblings, were compound heterozygotes for the nearby mutation c.499+5G>A (IVS3+5G>A) and for the frameshift-causing variant c.633delC (p.Trp212Glyfs(∗)18). In addition to CRD, these three individuals had hearing loss or hearing deficit. Immunostaining highlighted the presence of CEP78 in the inner segments of retinal photoreceptors, predominantly of cones, and at the base of the primary cilium of fibroblasts. Interaction studies also showed that CEP78 binds to FAM161A, another ciliary protein associated with retinal degeneration. Finally, analysis of skin fibroblasts derived from affected individuals revealed abnormal ciliary morphology, as compared to that of control cells. Altogether, our data strongly suggest that mutations in CEP78 cause a previously undescribed clinical entity of a ciliary nature characterized by blindness and deafness but clearly distinct from Usher syndrome, a condition for which visual impairment is due to retinitis pigmentosa.
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20
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Pema M, Drusian L, Chiaravalli M, Castelli M, Yao Q, Ricciardi S, Somlo S, Qian F, Biffo S, Boletta A. mTORC1-mediated inhibition of polycystin-1 expression drives renal cyst formation in tuberous sclerosis complex. Nat Commun 2016; 7:10786. [PMID: 26931735 PMCID: PMC4778067 DOI: 10.1038/ncomms10786] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 01/20/2016] [Indexed: 01/07/2023] Open
Abstract
Previous studies report a cross-talk between the polycystic kidney disease (PKD) and tuberous sclerosis complex (TSC) genes. mTOR signalling is upregulated in PKD and rapamycin slows cyst expansion, whereas renal inactivation of the Tsc genes causes cysts. Here we identify a new interplay between the PKD and TSC genes, with important implications for the pathophysiology of both diseases. Kidney-specific inactivation of either Pkd1 or Tsc1 using an identical Cre (KspCre) results in aggressive or very mild PKD, respectively. Unexpectedly, we find that mTORC1 negatively regulates the biogenesis of polycystin-1 (PC-1) and trafficking of the PC-1/2 complex to cilia. Genetic interaction studies reveal an important role for PC-1 downregulation by mTORC1 in the cystogenesis of Tsc1 mutants. Our data potentially explain the severe renal manifestations of the TSC/PKD contiguous gene syndrome and open new perspectives for the use of mTOR inhibitors in autosomal dominant PKD caused by hypomorphic or missense PKD1 mutations. Polycystic kidney disease (PKD) is a ciliopathy resulting from defective localization of membrane proteins such as PC-1 to the primary cilium, resulting in renal cysts, and is associated with another cystic genetic disease called tuberous sclerosis complex (TSC). Here the authors use kidney-specific Tsc1 and Pkd1 mice to show that mTORC1 signalling inhibits PC-1 biogenesis as a potential mechanism of TSC/PKD contiguous gene syndrome.
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Affiliation(s)
- Monika Pema
- Division of Genetics and Cell Biology, Dibit San Raffaele Scientific Institute, Via Olgettina, 58, Milano 20132, Italy.,PhD Program in Biology and Biotherapy of Cancer, Università Vita-Salute San Raffaele, Via Olgettina, 58, Milano 20132, Italy
| | - Luca Drusian
- Division of Genetics and Cell Biology, Dibit San Raffaele Scientific Institute, Via Olgettina, 58, Milano 20132, Italy.,PhD Program in Biology and Biotherapy of Cancer, Università Vita-Salute San Raffaele, Via Olgettina, 58, Milano 20132, Italy
| | - Marco Chiaravalli
- Division of Genetics and Cell Biology, Dibit San Raffaele Scientific Institute, Via Olgettina, 58, Milano 20132, Italy
| | - Maddalena Castelli
- Division of Genetics and Cell Biology, Dibit San Raffaele Scientific Institute, Via Olgettina, 58, Milano 20132, Italy
| | - Qin Yao
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | | | - Stefan Somlo
- Department of Internal Medicine and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520-8029, USA
| | - Feng Qian
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Stefano Biffo
- INGM, Via Sforza 28, Milano 20122, Italy.,Department of Biosciences, University of Milan, Via Celoria, 26, Milano 20133, Italy
| | - Alessandra Boletta
- Division of Genetics and Cell Biology, Dibit San Raffaele Scientific Institute, Via Olgettina, 58, Milano 20132, Italy
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21
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Wu H, Chen J, Xu J, Dong Z, Meyuhas O, Chen JK. Blocking rpS6 Phosphorylation Exacerbates Tsc1 Deletion-Induced Kidney Growth. J Am Soc Nephrol 2015; 27:1145-58. [PMID: 26296742 DOI: 10.1681/asn.2014121264] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 07/16/2015] [Indexed: 11/03/2022] Open
Abstract
The molecular mechanisms underlying renal growth and renal growth-induced nephron damage remain poorly understood. Here, we report that in murine models, deletion of the tuberous sclerosis complex protein 1 (Tsc1) in renal proximal tubules induced strikingly enlarged kidneys, with minimal cystogenesis and occasional microscopic tumorigenesis. Signaling studies revealed hyperphosphorylation of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) and increased phosphorylation of ribosomal protein S6 (rpS6) in activated renal tubules. Notably, knockin of a nonphosphorylatable rpS6 in these Tsc1-mutant mice exacerbated cystogenesis and caused drastic nephron damage and renal fibrosis, leading to kidney failure and a premature death rate of 67% by 9 weeks of age. In contrast, Tsc1 single-mutant mice were all alive and had far fewer renal cysts at this age. Mechanistic studies revealed persistent activation of mammalian target of rapamycin complex 1 (mTORC1) signaling causing hyperphosphorylation and consequent accumulation of 4E-BP1, along with greater cell proliferation, in the renal tubules of Tsc1 and rpS6 double-mutant mice. Furthermore, pharmacologic treatment of Tsc1 single-mutant mice with rapamycin reduced hyperphosphorylation and accumulation of 4E-BP1 but also inhibited phosphorylation of rpS6. Rapamycin also exacerbated cystic and fibrotic lesions and impaired kidney function in these mice, consequently leading to a premature death rate of 40% within 2 weeks of treatment, despite destroying tumors and decreasing kidney size. These findings indicate that Tsc1 prevents aberrant renal growth and tumorigenesis by inhibiting mTORC1 signaling, whereas phosphorylated rpS6 suppresses cystogenesis and fibrosis in Tsc1-deleted kidneys.
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Affiliation(s)
- Huijuan Wu
- Department of Cellular Biology and Anatomy, Department of Medicine, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
| | - Jianchun Chen
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jinxian Xu
- Department of Cellular Biology and Anatomy, Department of Medicine, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Research Department, Charlie Norwood VA Medical Center, Augusta, Georgia; and
| | - Oded Meyuhas
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Jian-Kang Chen
- Department of Cellular Biology and Anatomy, Department of Medicine, Medical College of Georgia, Georgia Regents University, Augusta, Georgia;
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22
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Mitchell KAP. Isolation of primary cilia by shear force. CURRENT PROTOCOLS IN CELL BIOLOGY 2013; Chapter 3:3.42.1-3.42.9. [PMID: 23728745 DOI: 10.1002/0471143030.cb0342s59] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The cell's primary cilium is both a mechanical and chemical sensor involved in many signaling pathways. In order to ascertain protein enrichment in the primary cilium or study sub-ciliary localization of various proteins, it is advantageous to remove the primary cilium from the cell body. The protocol described here gives detailed instructions on purifying primary cilia by separating them from the cell body using shear force. This simple technique avoids using harsh purification conditions that may affect signaling proteins in the cilium or cause the ciliary membrane to disintegrate. In addition, as the cell body remains mostly intact, contamination of the isolated cilia by proteins from the cell body is minimized. This protocol is ideally suited for isolating cilia from renal cell lines, as primary cilia in these cells grow to greater lengths than in other cell types (up to 50-µm long in Xenopus A6 toad kidney cells as opposed to 1 to 5 µm in NIH3T3 fibroblast cells).
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23
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Cardenas-Rodriguez M, Irigoín F, Osborn DPS, Gascue C, Katsanis N, Beales PL, Badano JL. The Bardet-Biedl syndrome-related protein CCDC28B modulates mTORC2 function and interacts with SIN1 to control cilia length independently of the mTOR complex. Hum Mol Genet 2013; 22:4031-42. [PMID: 23727834 DOI: 10.1093/hmg/ddt253] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
CCDC28B encodes a coiled coil domain-containing protein involved in ciliogenesis that was originally identified as a second site modifier of the ciliopathy Bardet-Biedl syndrome. We have previously shown that the depletion of CCDC28B leads to shortened cilia; however, the mechanism underlying how this protein controls ciliary length is unknown. Here, we show that CCDC28B interacts with SIN1, a component of the mTOR complex 2 (mTORC2), and that this interaction is important both in the context of mTOR signaling and in a hitherto unknown, mTORC-independent role of SIN1 in cilia biology. We show that CCDC28B is a positive regulator of mTORC2, participating in its assembly/stability and modulating its activity, while not affecting mTORC1 function. Further, we show that Ccdc28b regulates cilia length in vivo, at least in part, through its interaction with Sin1. Importantly, depletion of Rictor, another core component of mTORC2, does not result in shortened cilia. Taken together, our findings implicate CCDC28B in the regulation of mTORC2, and uncover a novel function of SIN1 regulating cilia length that is likely independent of mTOR signaling.
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24
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Kotsis F, Boehlke C, Kuehn EW. The ciliary flow sensor and polycystic kidney disease. Nephrol Dial Transplant 2013; 28:518-26. [PMID: 23314319 PMCID: PMC3588856 DOI: 10.1093/ndt/gfs524] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Since the discovery that proteins mutated in different forms of polycystic kidney disease (PKD) are tightly associated with primary cilia, strong efforts have been made to define the role of this organelle in the pathogenesis of cyst formation. Cilia are filiform microtubular structures, anchored in the basal body and extending from the apical membrane into the tubular lumen. Early work established that cilia act as flow sensors, eliciting calcium transients in response to bending, which involve the two proteins mutated in autosomal dominant PKD (ADPKD), polycystin-1 and -2. Loss of cilia alone is insufficient to cause cyst formation. Nevertheless, a large body of evidence links flow sensing by cilia to aspects relevant for cyst formation such as cell polarity, Stat6- and mammalian target of rapamycin signalling. This review summarizes the current literature on cilia and flow sensing with respect to PKD and discusses how these findings intercalate with different aspects of cyst formation.
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Affiliation(s)
- Fruzsina Kotsis
- Department of Nephrology, University Hospital Freiburg, Freiburg,Germany
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