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Higginbotham H, Eom TY, Mariani LE, Bachleda A, Gukassyan V, Hirt J, Cusack C, Lai C, Caspary T, Anton ES. Arl13b in primary cilia regulates the migration and placement of interneurons in the developing cerebral cortex. Dev Cell 2012; 23:925-38. [PMID: 23153492 PMCID: PMC3529475 DOI: 10.1016/j.devcel.2012.09.019] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 05/31/2012] [Accepted: 09/22/2012] [Indexed: 11/19/2022]
Abstract
Coordinated migration and placement of interneurons and projection neurons lead to functional connectivity in the cerebral cortex; defective neuronal migration and the resultant connectivity changes underlie the cognitive defects in a spectrum of neurological disorders. Here we show that primary cilia play a guiding role in the migration and placement of postmitotic interneurons in the developing cerebral cortex and that this process requires the ciliary protein, Arl13b. Through live imaging of interneuronal cilia, we show that migrating interneurons display highly dynamic primary cilia and we correlate cilia dynamics with the interneuron's migratory state. We demonstrate that the guidance cue receptors essential for interneuronal migration localize to interneuronal primary cilia, but their concentration and dynamics are altered in the absence of Arl13b. Expression of Arl13b variants known to cause Joubert syndrome induce defective interneuronal migration, suggesting that defects in cilia-dependent interneuron migration may in part underlie the neurological defects in Joubert syndrome patients.
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Affiliation(s)
- Holden Higginbotham
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Tae-Yeon Eom
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Laura E. Mariani
- Neurosciences Graduate Program
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Amelia Bachleda
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Vladimir Gukassyan
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Joshua Hirt
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Corey Cusack
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Cary Lai
- Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - E. S. Anton
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
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Abstract
Adenomatous polyposis coli 2 (APC2) is a family member of APC and mainly expressed in the nervous system. We previously reported that APC2 plays a critical role in axonal projection through the regulation of microtubule stability. Here, we show that a lack of Apc2 induces severe laminary defects in some regions of the mouse brain, including the cerebral cortex and cerebellum. In vivo BrdU labeling and immunohistochemical analyses with specific markers revealed that the laminary abnormalities are a result of dysregulated neuronal migration by a cell-autonomous mechanism. Using total internal reflection fluorescent microscopy, we found that APC2 is distributed along actin fibers as well as microtubules. Cerebellar granule cells in dissociated cultures and in vivo showed that BDNF-stimulated directional migration is impaired in Apc2-deficient neurons. We revealed that this impairment stems from the dysregulations of Rho family GTPase activation and TrkB localization, which disrupts the formation of BDNF-stimulated F-actin at the leading edge. Thus, APC2 is an essential mediator of the cytoskeletal regulation at leading edges in response to extracellular signals.
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53
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Lo FY, Chen HT, Cheng HC, Hsu HS, Wang YC. Overexpression of PAFAH1B1 is associated with tumor metastasis and poor survival in non-small cell lung cancer. Lung Cancer 2012; 77:585-92. [PMID: 22749159 DOI: 10.1016/j.lungcan.2012.05.105] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 04/11/2012] [Accepted: 05/25/2012] [Indexed: 11/15/2022]
Abstract
Our previous array-comparative genomic hybridization study showed that PAFAH1B1 gene locus was amplified in lung cancer patients, suggesting that PAFAH1B1 is a potential oncogene in lung cancer. Here, we investigate the oncogenic mechanisms of PAFAH1B1 in lung cancer. PAFAH1B1 was characterized in cell and animal models of lung cancer by in vitro migration and invasion assays and in vivo metastasis studies. The mRNA and protein expression levels of PAFAH1B1 were further determined and the prognostic effects of PAFAH1B1 overexpression in lung cancer patients were analyzed. Overexpression of PAFAH1B1 enhanced migration and invasion in lung cancer cells, whereas knockdown of PAFAH1B1 decreased cell migration and invasion, and disrupted cell microtubule organization and pericellular poly-fibronectin assemblies. In vivo tumor metastasis assay confirmed that PAFAH1B1 knockdown in lung cancer cells markedly reduced their metastasis capabilities in animals. The frequencies of overexpressed PAFAH1B1 mRNA and protein were 62.4% (63/101) and 57.4% (58/101) in lung cancer patients, respectively. The clinical correlation results showed that overexpression of PAFAH1B1 was significantly associated with late stage (mRNA: P=0.008, protein: P=0.008) and poor survival in lung adenocarcinoma (P=0.020) and male patients (P=0.049). Our results provide the first evidence that PAFAH1B1 overexpression contributes to lung tumorigenesis and poor prognosis. These effects are partly mediated through disruption of microtubule network and pericellular poly-fibronectin assembly to promote migration and invasiveness of lung cancer cells.
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Affiliation(s)
- Fang-Yi Lo
- Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Foote M, Zhou Y. 14-3-3 proteins in neurological disorders. INTERNATIONAL JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 3:152-164. [PMID: 22773956 PMCID: PMC3388734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 04/28/2012] [Indexed: 06/01/2023]
Abstract
14-3-3 proteins were originally discovered as a family of proteins that are highly expressed in the brain. Through interactions with a multitude of binding partners, 14-3-3 proteins impact many aspects of brain function including neural signaling, neuronal development and neuroprotection. Although much remains to be learned and understood, 14-3-3 proteins have been implicated in a variety of neurological disorders based on evidence from both clinical and laboratory studies. Here we will review previous and more recent research that has helped us understand the roles of 14-3-3 proteins in both neurodegenerative and neuropsychiatric diseases.
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Affiliation(s)
- Molly Foote
- Department of Biomedical Sciences, Florida State University College of Medicine Tallahassee, FL 32306, USA
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Moore KD, Chen R, Cilluffo M, Golden JA, Phelps PE. Lis1 reduction causes tangential migratory errors in mouse spinal cord. J Comp Neurol 2012; 520:1198-211. [PMID: 21935943 PMCID: PMC4079006 DOI: 10.1002/cne.22768] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mutations in human LIS1 cause abnormal neuronal migration and a smooth brain phenotype known as lissencephaly. Lis1+/− (Pafah1b1) mice show defective lamination in the cerebral cortex and hippocampal formation, whereas homozygous mutations result in embryonic lethality. Given that Lis1 is highly expressed in embryonic neurons, we hypothesized that sympathetic and parasympathetic preganglionic neurons (SPNs and PPNs) would exhibit migratory defects in Lis1+/− mice. The initial radial migration of SPNs and PPNs that occurs together with somatic motor neurons appeared unaffected in Lis1+/− mice. The subsequent dorsally directed tangential migration, however, was aberrant in a subset of these neurons. At all embryonic ages analyzed, the distribution of SPNs and PPNs in Lis1+/− mice was elongated dorsoventrally compared with Lis1+/+ mice. Individual cell bodies of ectopic preganglionic neurons were found in the ventral spinal cord with their leading processes oriented along their dorsal migratory trajectory. By birth, Lis1+/− SPNs and PPNs were separated into distinct groups, those that were correctly, and those incorrectly positioned in the intermediate horn. As mispositioned SPNs and PPNs still were detected in P30 Lis1+/− mice, we conclude that these neurons ceased migration prematurely. Additionally, we found that a dorsally located group of somatic motor neurons in the lumbar spinal cord, the retrodorsolateral nucleus, showed delayed migration in Lis1+/− mice. These results suggest that Lis1 is required for the dorsally directed tangential migration of many sympathetic and parasympathetic preganglionic neurons and a subset of somatic motor neurons.
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Affiliation(s)
- Katherine D. Moore
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, California 90095-7239
| | - Renee Chen
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, California 90095-7239
| | - Marianne Cilluffo
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, California 90095-7239
| | - Jeffrey A. Golden
- Department of Pathology and Laboratory Medicine, The Children’s Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Patricia E. Phelps
- Department of Integrative Biology and Physiology, UCLA, Los Angeles, California 90095-7239
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56
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Chow ML, Pramparo T, Winn ME, Barnes CC, Li HR, Weiss L, Fan JB, Murray S, April C, Belinson H, Fu XD, Wynshaw-Boris A, Schork NJ, Courchesne E. Age-dependent brain gene expression and copy number anomalies in autism suggest distinct pathological processes at young versus mature ages. PLoS Genet 2012; 8:e1002592. [PMID: 22457638 PMCID: PMC3310790 DOI: 10.1371/journal.pgen.1002592] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 01/22/2012] [Indexed: 01/09/2023] Open
Abstract
Autism is a highly heritable neurodevelopmental disorder, yet the genetic underpinnings of the disorder are largely unknown. Aberrant brain overgrowth is a well-replicated observation in the autism literature; but association, linkage, and expression studies have not identified genetic factors that explain this trajectory. Few studies have had sufficient statistical power to investigate whole-genome gene expression and genotypic variation in the autistic brain, especially in regions that display the greatest growth abnormality. Previous functional genomic studies have identified possible alterations in transcript levels of genes related to neurodevelopment and immune function. Thus, there is a need for genetic studies involving key brain regions to replicate these findings and solidify the role of particular functional pathways in autism pathogenesis. We therefore sought to identify abnormal brain gene expression patterns via whole-genome analysis of mRNA levels and copy number variations (CNVs) in autistic and control postmortem brain samples. We focused on prefrontal cortex tissue where excess neuron numbers and cortical overgrowth are pronounced in the majority of autism cases. We found evidence for dysregulation in pathways governing cell number, cortical patterning, and differentiation in young autistic prefrontal cortex. In contrast, adult autistic prefrontal cortex showed dysregulation of signaling and repair pathways. Genes regulating cell cycle also exhibited autism-specific CNVs in DNA derived from prefrontal cortex, and these genes were significantly associated with autism in genome-wide association study datasets. Our results suggest that CNVs and age-dependent gene expression changes in autism may reflect distinct pathological processes in the developing versus the mature autistic prefrontal cortex. Our results raise the hypothesis that genetic dysregulation in the developing brain leads to abnormal regional patterning, excess prefrontal neurons, cortical overgrowth, and neural dysfunction in autism. Autism is a disorder characterized by aberrant social, communication, and restricted and repetitive behaviors. It develops clinically in the first years of life. Toddlers and children with autism often exhibit early brain enlargement and excess neuron numbers in the prefrontal cortex. Adults with autism generally do not display enlargement but instead may have a smaller brain size. Thus, we investigated DNA and mRNA patterns in prefrontal cortex from young versus adult postmortem individuals with autism to identify age-related gene expression differences as well as possible genetic correlates of abnormal brain enlargement, excess neuron numbers, and abnormal functioning in this disorder. We found abnormalities in genetic pathways governing cell number, neurodevelopment, and cortical lateralization in autism. We also found that the key pathways associated with autism are different between younger and older autistic individuals. These findings suggest that dysregulated gene pathways in the early stages of neurodevelopment could lead to later behavioral and cognitive deficits associated with autism.
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Affiliation(s)
- Maggie L. Chow
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Tiziano Pramparo
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- Division of Medical Genetics, Department of Pediatrics and Institute of Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Mary E. Winn
- Scripps Genomic Medicine and The Scripps Translational Sciences Institute (STSI), La Jolla, California, United States of America
- Graduate Program in Biomedical Sciences, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Cynthia Carter Barnes
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Hai-Ri Li
- Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Lauren Weiss
- Department of Psychiatry, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Jian-Bing Fan
- Illumina, San Diego, California, United States of America
| | - Sarah Murray
- Scripps Genomic Medicine and The Scripps Translational Sciences Institute (STSI), La Jolla, California, United States of America
| | - Craig April
- Illumina, San Diego, California, United States of America
| | - Haim Belinson
- Division of Medical Genetics, Department of Pediatrics and Institute of Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Anthony Wynshaw-Boris
- Division of Medical Genetics, Department of Pediatrics and Institute of Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Nicholas J. Schork
- Scripps Genomic Medicine and The Scripps Translational Sciences Institute (STSI), La Jolla, California, United States of America
- * E-mail: (NJS); (EC)
| | - Eric Courchesne
- Department of Neuroscience, NIH–UCSD Autism Center of Excellence, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (NJS); (EC)
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Funaya C, Samarasinghe S, Pruggnaller S, Ohta M, Connolly Y, Müller J, Murakami H, Grallert A, Yamamoto M, Smith D, Antony C, Tanaka K. Transient structure associated with the spindle pole body directs meiotic microtubule reorganization in S. pombe. Curr Biol 2012; 22:562-74. [PMID: 22425159 PMCID: PMC3382715 DOI: 10.1016/j.cub.2012.02.042] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/10/2012] [Accepted: 02/17/2012] [Indexed: 02/06/2023]
Abstract
Background Vigorous chromosome movements driven by cytoskeletal assemblies are a widely conserved feature of sexual differentiation to facilitate meiotic recombination. In fission yeast, this process involves the dramatic conversion of arrays of cytoplasmic microtubules (MTs), generated from multiple MT organizing centers (MTOCs), into a single radial MT (rMT) array associated with the spindle pole body (SPB), the major MTOC during meiotic prophase. The rMT is then dissolved upon the onset of meiosis I when a bipolar spindle emerges to conduct chromosome segregation. Structural features and molecular mechanisms that govern these dynamic MT rearrangements are poorly understood. Results Electron tomography of the SPBs showed that the rMT emanates from a newly recognized amorphous structure, which we term the rMTOC. The rMTOC, which resides at the cytoplasmic side of the SPB, is highly enriched in γ-tubulin reminiscent of the pericentriolar material of higher eukaryotic centrosomes. Formation of the rMTOC depends on Hrs1/Mcp6, a meiosis-specific SPB component that is located at the rMTOC. At the onset of meiosis I, Hrs1/Mcp6 is subject to strict downregulation by both proteasome-dependent degradation and phosphorylation leading to complete inactivation of the rMTOC. This ensures rMT dissolution and bipolar spindle formation. Conclusions Our study reveals the molecular basis for the transient generation of a novel MTOC, which triggers a program of MT rearrangement that is required for meiotic differentiation.
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Affiliation(s)
- Charlotta Funaya
- Electron Microscopy Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
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58
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Bradshaw NJ, Porteous DJ. DISC1-binding proteins in neural development, signalling and schizophrenia. Neuropharmacology 2012; 62:1230-41. [PMID: 21195721 PMCID: PMC3275753 DOI: 10.1016/j.neuropharm.2010.12.027] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 12/17/2010] [Accepted: 12/22/2010] [Indexed: 12/18/2022]
Abstract
In the decade since Disrupted in Schizophrenia 1 (DISC1) was first identified it has become one of the most convincing risk genes for major mental illness. As a multi-functional scaffold protein, DISC1 has multiple identified protein interaction partners that highlight pathologically relevant molecular pathways with potential for pharmaceutical intervention. Amongst these are proteins involved in neuronal migration (e.g. APP, Dixdc1, LIS1, NDE1, NDEL1), neural progenitor proliferation (GSK3β), neurosignalling (Girdin, GSK3β, PDE4) and synaptic function (Kal7, TNIK). Furthermore, emerging evidence of genetic association (NDEL1, PCM1, PDE4B) and copy number variation (NDE1) implicate several DISC1-binding partners as risk factors for schizophrenia in their own right. Thus, a picture begins to emerge of DISC1 as a key hub for multiple critical developmental pathways within the brain, disruption of which can lead to a variety of psychiatric illness phenotypes.
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Key Words
- disc1
- schizophrenia
- neurodevelopment
- signalling
- synapse
- association studies
- app, amyloid precursor protein
- atf4, activating transcription factor 4
- bace1, β-site app-cleaving enzyme-1
- bbs4, bardet–biedl syndrome 4
- cep290, centrosomal protein 290 kda
- cnv, copy number variation
- cre, camp response element
- dbz, disc1-binding zinc finger
- disc1, disrupted in schizophrenia 1
- dixdc1, dishevelled-axin domain containing-1
- fez1, fasciculation and elongation protein zeta 1
- glur, glutamate receptor
- gsk3β, glycogen synthase kinase 3β
- kal7, kalirin-7
- lef/tcf, lymphoid enhancer factor/t cell factor
- lis1, lissencephaly 1
- mtor, mammalian target of rapamycin
- nde1, nuclear distribution factor e homologue 1 or nuclear distribution element 1
- ndel1, nde-like 1
- nrg, neuregulin
- pacap, pituitary adenylate cyclase-activating polypeptide
- pcm1, pericentriolar material 1
- pcnt, pericentrin
- pde4, phosphodiesterase 4
- pi3 k, phosphatidylinositiol 3-kinase
- psd, post-synaptic density
- rac1, ras-related c3 botulinum toxin substrate 1
- tnik, traf2 and nck interacting kinase
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Affiliation(s)
- Nicholas J. Bradshaw
- Medical Genetics Section, Molecular Medicine Centre, Institute of Genetics & Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh, Midlothian EH4 2XU, UK
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59
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Patterson NB. Sudden Death in a 61-Year-Old Woman with Subcortical Band Heterotopia. Acad Forensic Pathol 2012. [DOI: 10.23907/2012.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Subcortical band heterotopia (SBH), also known as double cortex syndrome, is a rare congenital abnormality seen almost exclusively in women. Affected individuals present with seizures, decreased cognitive ability, and behavioral problems, all of which may be expressed with variable severity. The diagnosis is considered with the characteristic MRI findings coupled with the neurologic features and appropriate family history. The rarity of this disorder combined with the typically early presentation with seizures and the characteristic imaging findings make initial diagnosis in a forensic setting unlikely. Therefore, to our knowledge, SBH has not been described in the forensic literature. This case demonstrates a case of sudden death in a woman with known epilepsy, without further clinical history available at the time of autopsy.
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Abstract
The organization and function of eukaryotic cells rely on the action of many different molecular motor proteins. Cytoplasmic dynein drives the movement of a wide range of cargoes towards the minus ends of microtubules, and these events are needed, not just at the single-cell level, but are vital for correct development. In the present paper, I review recent progress on understanding dynein's mechanochemistry, how it is regulated and how it binds to such a plethora of cargoes. The importance of a number of accessory factors in these processes is discussed.
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Bechler ME, de Figueiredo P, Brown WJ. A PLA1-2 punch regulates the Golgi complex. Trends Cell Biol 2011; 22:116-24. [PMID: 22130221 DOI: 10.1016/j.tcb.2011.10.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 10/19/2011] [Accepted: 10/20/2011] [Indexed: 12/14/2022]
Abstract
The mammalian Golgi complex, trans Golgi network (TGN) and ER-Golgi intermediate compartment (ERGIC) are comprised of membrane cisternae, coated vesicles and membrane tubules, all of which contribute to membrane trafficking and maintenance of their unique architectures. Recently, a new cast of players was discovered to regulate the Golgi and ERGIC: four unrelated cytoplasmic phospholipase A (PLA) enzymes, cPLA(2)α (GIVA cPLA(2)), PAFAH Ib (GVIII PLA(2)), iPLA(2)-β (GVIA-2 iPLA(2)) and iPLA(1)γ. These ubiquitously expressed enzymes regulate membrane trafficking from specific Golgi subcompartments, although there is evidence for some functional redundancy between PAFAH Ib and cPLA(2)α. Three of these enzymes, PAFAH Ib, cPLA(2)α and iPLA(2)-β, exert effects on Golgi structure and function by inducing the formation of membrane tubules. We review our current understanding of how PLA enzymes regulate Golgi and ERGIC morphology and function.
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Affiliation(s)
- Marie E Bechler
- Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY 14853, USA
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62
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Ye S, Fowler TW, Pavlos NJ, Ng PY, Liang K, Feng Y, Zheng M, Kurten R, Manolagas SC, Zhao H. LIS1 regulates osteoclast formation and function through its interactions with dynein/dynactin and Plekhm1. PLoS One 2011; 6:e27285. [PMID: 22073305 PMCID: PMC3207863 DOI: 10.1371/journal.pone.0027285] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 10/13/2011] [Indexed: 11/19/2022] Open
Abstract
Microtubule organization and lysosomal secretion are both critical for the activation and function of osteoclasts, highly specialized polykaryons that are responsible for bone resorption and skeletal homeostasis. Here, we have identified a novel interaction between microtubule regulator LIS1 and Plekhm1, a lysosome-associated protein implicated in osteoclast secretion. Decreasing LIS1 expression by shRNA dramatically attenuated osteoclast formation and function, as shown by a decreased number of mature osteoclasts differentiated from bone marrow macrophages, diminished resorption pits formation, and reduced level of CTx-I, a bone resorption marker. The ablated osteoclast formation in LIS1-depleted macrophages was associated with a significant decrease in macrophage proliferation, osteoclast survival and differentiation, which were caused by reduced activation of ERK and AKT by M-CSF, prolonged RANKL-induced JNK activation and declined expression of NFAT-c1, a master transcription factor of osteoclast differentiation. Consistent with its critical role in microtubule organization and dynein function in other cell types, we found that LIS1 binds to and colocalizes with dynein in osteoclasts. Loss of LIS1 led to disorganized microtubules and aberrant dynein function. More importantly, the depletion of LIS1 in osteoclasts inhibited the secretion of Cathepsin K, a crucial lysosomal hydrolase for bone degradation, and reduced the motility of osteoclast precursors. These results indicate that LIS1 is a previously unrecognized regulator of osteoclast formation, microtubule organization, and lysosomal secretion by virtue of its ability to modulate dynein function and Plekhm1.
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Affiliation(s)
- Shiqiao Ye
- Center for Osteoporosis and Metabolic Bone Diseases, Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Arkansas for Medical Sciences and the Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, United States of America
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Chansard M, Hong JH, Park YU, Park SK, Nguyen MD. Ndel1, Nudel (Noodle): flexible in the cell? Cytoskeleton (Hoboken) 2011; 68:540-54. [PMID: 21948775 DOI: 10.1002/cm.20532] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 09/08/2011] [Accepted: 09/09/2011] [Indexed: 02/06/2023]
Abstract
Nuclear distribution element-like 1 (Ndel1 or Nudel) was firstly described as a regulator of the cytoskeleton in microtubule and intermediate filament dynamics and microtubule-based transport. Emerging evidence indicates that Ndel1 also serves as a docking platform for signaling proteins and modulates enzymatic activities (kinase, ATPase, oligopeptidase, GTPase). Through these structural and signaling functions, Ndel1 plays a role in diverse cellular processes (e.g., mitosis, neurogenesis, neurite outgrowth, and neuronal migration). Furthermore, Ndel1 is linked to the etiology of various mental illnesses and neurodegenerative disorders. In the present review, we summarize the physiological and pathological functions associated with Ndel1. We further advance the concept that Ndel1 interfaces GTPases-mediated processes (endocytosis, vesicles morphogenesis/signaling) and cytoskeletal dynamics to impact cell signaling and behaviors. This putative mechanism may affect cellular functionalities and may contribute to shed light into the causes of devastating human diseases.
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Affiliation(s)
- Mathieu Chansard
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
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64
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Stolp HB, Turnquist C, Dziegielewska KM, Saunders NR, Anthony DC, Molnár Z. Reduced ventricular proliferation in the foetal cortex following maternal inflammation in the mouse. Brain 2011; 134:3236-48. [PMID: 21964917 PMCID: PMC3212715 DOI: 10.1093/brain/awr237] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
It has been well established that maternal inflammation during pregnancy alters neurological function in the offspring, but its impact on cortical development and long-term consequences on the cytoarchitecture is largely unstudied. Here we report that lipopolysaccharide-induced systemic maternal inflammation in C57Bl/6 mice at embryonic Day 13.5 of pregnancy, as early as 8 h after challenge, caused a significant reduction in cell proliferation in the ventricular zone of the developing cerebral cortex, as revealed by quantification of anti-phospho-Histone H3 immunoreactivity and bromodeoxyuridine pulse labelling. The angle of mitotic cleavage, determined from analysis of haematoxylin and eosin staining, cyclin E1 gene expression and the pattern of β-catenin immunoreactivity were also altered by the challenge, which suggests a change from symmetric to asymmetric division in the radial progenitor cells. Modifications of cortical lamination and gene expression patterns were detected at post-natal Day 8 suggesting prolonged consequences of these alterations during embryonic development. Cellular uptake of proteins from the cerebrospinal fluid was observed in brains from lipopolysaccharide-treated animals in radial progenitor cells. However, the foetal blood–brain barrier to plasma proteins remained intact. Together, these results indicate that maternal inflammation can disrupt the ventricular surface and lead to decreased cellular proliferation. Changes in cell density in Layers IV and V at post-natal Day 8 show that these initial changes have prolonged effects on cortical organization. The possible shift in the fate of progeny and the resulting alterations in the relative cell numbers in the cerebral cortex following a maternal inflammatory response shown here will require further investigation to determine the long-term consequences of inflammation on the development of neuronal circuitry and behaviour.
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Affiliation(s)
- Helen B Stolp
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK.
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Lee KI, Lim CY, Kang BT, Park HM. Clinical and MRI findings of lissencephaly in a mixed breed dog. J Vet Med Sci 2011; 73:1385-8. [PMID: 21685716 DOI: 10.1292/jvms.11-0117] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A 7-year-old castrated male mixed-breed dog was presented with a complaint of acute pain. The dog had suffered from isolated seizures for two years. Magnetic resonance imaging (MRI) of the brain revealed a smooth brain surface due to lack of gyri and sulci formation of the cerebrum and thick cortical grey matter. Additionally, ventriculomegaly and an arachnoid cyst were noted. Multiple spinal cord compressions induced by intervertebral disc protrusion were observed on a cervical MRI. Based on these findings, the dog was diagnosed as having lissencephaly concurrent with intervertebral cervical disease. After therapy for seizure and cervical pain, the clinical signs were completely resolved. To the author's knowledge, this is the case report to diagnose lissencephaly in a mixed-breed dog.
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Affiliation(s)
- Kyo-Im Lee
- BK21 Basic & Diagnostic Veterinary Specialist Program for Animal Diseases and Department of Veterinary Internal Medicine, College of Veterinary Medicine, Konkuk University, Seoul, Korea
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Alkuraya F, Cai X, Emery C, Mochida G, Al-Dosari M, Felie J, Hill R, Barry B, Partlow J, Gascon G, Kentab A, Jan M, Shaheen R, Feng Y, Walsh C. Human mutations in NDE1 cause extreme microcephaly with lissencephaly [corrected]. Am J Hum Genet 2011; 88:536-47. [PMID: 21529751 PMCID: PMC3146728 DOI: 10.1016/j.ajhg.2011.04.003] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 03/25/2011] [Accepted: 04/07/2011] [Indexed: 11/23/2022] Open
Abstract
Genes disrupted in human microcephaly (meaning "small brain") define key regulators of neural progenitor proliferation and cell-fate specification. In comparison, genes mutated in human lissencephaly (lissos means smooth and cephalos means brain) highlight critical regulators of neuronal migration. Here, we report two families with extreme microcephaly and grossly simplified cortical gyral structure, a condition referred to as microlissencephaly, and show that they carry homozygous frameshift mutations in NDE1, which encodes a multidomain protein that localizes to the centrosome and mitotic spindle poles. Both human mutations in NDE1 truncate the C-terminal NDE1domains, which are essential for interactions with cytoplasmic dynein and thus for regulation of cytoskeletal dynamics in mitosis and for cell-cycle-dependent phosphorylation of NDE1 by Cdk1. We show that the patient NDE1 proteins are unstable, cannot bind cytoplasmic dynein, and do not localize properly to the centrosome. Additionally, we show that CDK1 phosphorylation at T246, which is within the C-terminal region disrupted by the mutations, is required for cell-cycle progression from the G2 to the M phase. The role of NDE1 in cell-cycle progression probably contributes to the profound neuronal proliferation defects evident in Nde1-null mice and patients with NDE1 mutations, demonstrating the essential role of NDE1 in human cerebral cortical neurogenesis.
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Affiliation(s)
- Fowzan S. Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
- Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh 11472, Saudi Arabia
| | - Xuyu Cai
- Division of Genetics, Howard Hughes Medical Institute, and Manton Center for Orphan Disease Research, Children's Hospital Boston, Boston, MA 02215, USA
- Program in Biomedical and Biological Sciences, Harvard Medical School, Boston, MA 02215, USA
| | - Carina Emery
- Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Ganeshwaran H. Mochida
- Division of Genetics, Howard Hughes Medical Institute, and Manton Center for Orphan Disease Research, Children's Hospital Boston, Boston, MA 02215, USA
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02215, USA
- Pediatric Neurology Unit, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Mohammed S. Al-Dosari
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Jillian M. Felie
- Division of Genetics, Howard Hughes Medical Institute, and Manton Center for Orphan Disease Research, Children's Hospital Boston, Boston, MA 02215, USA
| | - R. Sean Hill
- Division of Genetics, Howard Hughes Medical Institute, and Manton Center for Orphan Disease Research, Children's Hospital Boston, Boston, MA 02215, USA
| | - Brenda J. Barry
- Division of Genetics, Howard Hughes Medical Institute, and Manton Center for Orphan Disease Research, Children's Hospital Boston, Boston, MA 02215, USA
| | - Jennifer N. Partlow
- Division of Genetics, Howard Hughes Medical Institute, and Manton Center for Orphan Disease Research, Children's Hospital Boston, Boston, MA 02215, USA
| | - Generoso G. Gascon
- Department of Neurology, King Faisal Hospital and Research Centre, Jeddah 11211, Saudi Arabia
| | - Amal Kentab
- Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh 11472, Saudi Arabia
| | - Mohammad Jan
- Department of Neurology, King Faisal Hospital and Research Centre, Jeddah 11211, Saudi Arabia
| | - Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Yuanyi Feng
- Department of Neurology and Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Christopher A. Walsh
- Division of Genetics, Howard Hughes Medical Institute, and Manton Center for Orphan Disease Research, Children's Hospital Boston, Boston, MA 02215, USA
- Program in Biomedical and Biological Sciences, Harvard Medical School, Boston, MA 02215, USA
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02215, USA
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67
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Copp AJ, Carvalho R, Wallace A, Sorokin L, Sasaki T, Greene NDE, Ybot-Gonzalez P. Regional differences in the expression of laminin isoforms during mouse neural tube development. Matrix Biol 2011; 30:301-9. [PMID: 21524702 DOI: 10.1016/j.matbio.2011.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 04/01/2011] [Accepted: 04/05/2011] [Indexed: 01/13/2023]
Abstract
Many significant human birth defects originate around the time of neural tube closure or early during post-closure nervous system development. For example, failure of the neural tube to close generates anencephaly and spina bifida, faulty cell cycle progression is implicated in primary microcephaly, while defective migration of neuroblasts can lead to neuronal migration disorders such as lissencephaly. At the stage of neural tube closure, basement membranes are becoming organised around the neuroepithelium, and beneath the adjacent non-neural surface ectoderm. While there is circumstantial evidence to implicate basement membrane dynamics in neural tube and surface ectodermal development, we have an incomplete understanding of the molecular composition of basement membranes at this stage. In the present study, we examined the developing basement membranes of the mouse embryo at mid-gestation (embryonic day 9.5), with particular reference to laminin composition. We performed in situ hybridization to detect the mRNAs of all eleven individual laminin chains, and immunohistochemistry to identify which laminin chains are present in the basement membranes. From this information, we inferred the likely laminin variants and their tissues of origin: that is, whether a given basement membrane laminin is contributed by epithelium, mesenchyme, or both. Our findings reveal major differences in basement composition along the body axis, with the rostral neural tube (at mandibular arch and heart levels) exhibiting many distinct laminin variants, while the lumbar level where the neural tube is just closing shows a much simpler laminin profile. Moreover, there appears to be a marked difference in the extent to which the mesenchyme contributes laminin variants to the basement membrane, with potential contribution of several laminins rostrally, but no contribution caudally. This information paves the way towards a mechanistic analysis of basement membrane laminin function during early neural tube development in mammals.
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Affiliation(s)
- Andrew J Copp
- Neural Development Unit, Institute of Child Health, University College London, UK
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Pramparo T, Libiger O, Jain S, Li H, Youn YH, Hirotsune S, Schork NJ, Wynshaw-Boris A. Global developmental gene expression and pathway analysis of normal brain development and mouse models of human neuronal migration defects. PLoS Genet 2011; 7:e1001331. [PMID: 21423666 PMCID: PMC3053345 DOI: 10.1371/journal.pgen.1001331] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 02/08/2011] [Indexed: 01/01/2023] Open
Abstract
Heterozygous LIS1 mutations are the most common cause of human lissencephaly, a human neuronal migration defect, and DCX mutations are the most common cause of X-linked lissencephaly. LIS1 is part of a protein complex including NDEL1 and 14-3-3ε that regulates dynein motor function and microtubule dynamics, while DCX stabilizes microtubules and cooperates with LIS1 during neuronal migration and neurogenesis. Targeted gene mutations of Lis1, Dcx, Ywhae (coding for 14-3-3ε), and Ndel1 lead to neuronal migration defects in mouse and provide models of human lissencephaly, as well as aid the study of related neuro-developmental diseases. Here we investigated the developing brain of these four mutants and wild-type mice using expression microarrays, bioinformatic analyses, and in vivo/in vitro experiments to address whether mutations in different members of the LIS1 neuronal migration complex lead to similar and/or distinct global gene expression alterations. Consistent with the overall successful development of the mutant brains, unsupervised clustering and co-expression analysis suggested that cell cycle and synaptogenesis genes are similarly expressed and co-regulated in WT and mutant brains in a time-dependent fashion. By contrast, focused co-expression analysis in the Lis1 and Ndel1 mutants uncovered substantial differences in the correlation among pathways. Differential expression analysis revealed that cell cycle, cell adhesion, and cytoskeleton organization pathways are commonly altered in all mutants, while synaptogenesis, cell morphology, and inflammation/immune response are specifically altered in one or more mutants. We found several commonly dysregulated genes located within pathogenic deletion/duplication regions, which represent novel candidates of human mental retardation and neurocognitive disabilities. Our analysis suggests that gene expression and pathway analysis in mouse models of a similar disorder or within a common pathway can be used to define novel candidates for related human diseases.
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Affiliation(s)
- Tiziano Pramparo
- Department of Pediatrics and Institute for Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Departments of Pediatrics and Medicine, Center for Human Genetics and Genomics, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Ondrej Libiger
- The Scripps Research Institute and the Scripps Translational Science Institute, La Jolla, California United States of America
| | - Sonia Jain
- Department of Family and Preventive Medicine, Division of Biostatistics and Bioinformatics, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Hong Li
- Departments of Pediatrics and Medicine, Center for Human Genetics and Genomics, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Yong Ha Youn
- Department of Pediatrics and Institute for Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Departments of Pediatrics and Medicine, Center for Human Genetics and Genomics, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Shinji Hirotsune
- Department of Genetic Disease Research, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Nicholas J. Schork
- The Scripps Research Institute and the Scripps Translational Science Institute, La Jolla, California United States of America
| | - Anthony Wynshaw-Boris
- Department of Pediatrics and Institute for Human Genetics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Departments of Pediatrics and Medicine, Center for Human Genetics and Genomics, School of Medicine, University of California San Diego, La Jolla, California, United States of America
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Role of cytoskeletal abnormalities in the neuropathology and pathophysiology of type I lissencephaly. Acta Neuropathol 2011; 121:149-70. [PMID: 21046408 PMCID: PMC3037170 DOI: 10.1007/s00401-010-0768-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 10/01/2010] [Accepted: 10/23/2010] [Indexed: 01/24/2023]
Abstract
Type I lissencephaly or agyria-pachygyria is a rare developmental disorder which results from a defect of neuronal migration. It is characterized by the absence of gyri and a thickening of the cerebral cortex and can be associated with other brain and visceral anomalies. Since the discovery of the first genetic cause (deletion of chromosome 17p13.3), six additional genes have been found to be responsible for agyria–pachygyria. In this review, we summarize the current knowledge concerning these genetic disorders including clinical, neuropathological and molecular results. Genetic alterations of LIS1, DCX, ARX, TUBA1A, VLDLR, RELN and more recently WDR62 genes cause migrational abnormalities along with more complex and subtle anomalies affecting cell proliferation and differentiation, i.e., neurite outgrowth, axonal pathfinding, axonal transport, connectivity and even myelination. The number and heterogeneity of clinical, neuropathological and radiological defects suggest that type I lissencephaly now includes several forms of cerebral malformations. In vitro experiments and mutant animal studies, along with neuropathological abnormalities in humans are of invaluable interest for the understanding of pathophysiological mechanisms, highlighting the central role of cytoskeletal dynamics required for a proper achievement of cell proliferation, neuronal migration and differentiation.
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