1
|
Gefen AM, Zaritsky JJ. Review of childhood genetic nephrolithiasis and nephrocalcinosis. Front Genet 2024; 15:1381174. [PMID: 38606357 PMCID: PMC11007102 DOI: 10.3389/fgene.2024.1381174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 03/04/2024] [Indexed: 04/13/2024] Open
Abstract
Nephrolithiasis (NL) is a common condition worldwide. The incidence of NL and nephrocalcinosis (NC) has been increasing, along with their associated morbidity and economic burden. The etiology of NL and NC is multifactorial and includes both environmental components and genetic components, with multiple studies showing high heritability. Causative gene variants have been detected in up to 32% of children with NL and NC. Children with NL and NC are genotypically heterogenous, but often phenotypically relatively homogenous, and there are subsequently little data on the predictors of genetic childhood NL and NC. Most genetic diseases associated with NL and NC are secondary to hypercalciuria, including those secondary to hypercalcemia, renal phosphate wasting, renal magnesium wasting, distal renal tubular acidosis (RTA), proximal tubulopathies, mixed or variable tubulopathies, Bartter syndrome, hyperaldosteronism and pseudohyperaldosteronism, and hyperparathyroidism and hypoparathyroidism. The remaining minority of genetic diseases associated with NL and NC are secondary to hyperoxaluria, cystinuria, hyperuricosuria, xanthinuria, other metabolic disorders, and multifactorial etiologies. Genome-wide association studies (GWAS) in adults have identified multiple polygenic traits associated with NL and NC, often involving genes that are involved in calcium, phosphorus, magnesium, and vitamin D homeostasis. Compared to adults, there is a relative paucity of studies in children with NL and NC. This review aims to focus on the genetic component of NL and NC in children.
Collapse
Affiliation(s)
- Ashley M. Gefen
- Phoenix Children’s Hospital, Department of Pediatrics, Division of Nephrology, Phoenix, AZ, United States
| | | |
Collapse
|
2
|
Bansal S, Rahman M, Ravichandran R, Canez J, Fleming T, Mohanakumar T. Extracellular Vesicles in Transplantation: Friend or Foe. Transplantation 2024; 108:374-385. [PMID: 37482627 DOI: 10.1097/tp.0000000000004693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
The long-term function of transplanted organs, even under immunosuppression, is hindered by rejection, especially chronic rejection. Chronic rejection occurs more frequently after lung transplantation, termed chronic lung allograft dysfunction (CLAD), than after transplantation of other solid organs. Pulmonary infection is a known risk factor for CLAD, as transplanted lungs are constantly exposed to the external environment; however, the mechanisms by which respiratory infections lead to CLAD are poorly understood. The role of extracellular vesicles (EVs) in transplantation remains largely unknown. Current evidence suggests that EVs released from transplanted organs can serve as friend and foe. EVs carry not only major histocompatibility complex antigens but also tissue-restricted self-antigens and various transcription factors, costimulatory molecules, and microRNAs capable of regulating alloimmune responses. EVs play an important role in antigen presentation by direct, indirect, and semidirect pathways in which CD8 and CD4 cells can be activated. During viral infections, exosomes (small EVs <200 nm in diameter) can express viral antigens and regulate immune responses. Circulating exosomes may also be a viable biomarker for other diseases and rejection after organ transplantation. Bioengineering the surface of exosomes has been proposed as a tool for targeted delivery of drugs and personalized medicine. This review focuses on recent studies demonstrating the role of EVs with a focus on exosomes and their dual role (immune activation or tolerance induction) after organ transplantation, more specifically, lung transplantation.
Collapse
Affiliation(s)
- Sandhya Bansal
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ
| | | | | | | | | | | |
Collapse
|
3
|
Ancora C, Marchi M, Bonardi CM, Sartori G, Lopreiato R, Zuccarello D, D'Errico I, Nosadini M, Sartori S, Boniver C, Toldo I, Salviati L. Electroclinical Features in Two Novel STRADA Patients and a Functional Yeast Assay for the Validation of Missense STRADA Mutations. Pediatr Neurol 2023; 148:152-156. [PMID: 37722301 DOI: 10.1016/j.pediatrneurol.2023.08.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 09/20/2023]
Abstract
Loss of function of the STRADA gene, an upstream mTOR inhibitor, causes a rare neurodevelopmental disorder characterized by polyhydramnios, megalencephaly, and symptomatic epilepsy (PMSE syndrome). Patients display a homogeneous phenotype including early-onset drug-resistant epilepsy, severe psychomotor delay, multisystemic comorbidities, and increased risk of premature death. The administration of sirolimus, an mTOR inhibitor, is helpful in controlling seizures in this syndrome. We report the electroclinical phenotype of two novel patients and the development of a yeast model to validate the pathogenicity of missense variants. Patient 1 harbored a missense STRADA variant and had a peculiar electroclinical phenotype with a relatively mild epilepsy course. Patient 2 harbored a truncating STRADA variant and showed a typical PMSE phenotype and a favorable response to early treatment with sirolimus. When we modeled the p.(Ser264Arg) STRADA change in its yeast homolog SPS1, it impaired SPS1 function. The results underlie the importance of a timely molecular diagnosis in these patients and show that yeast is a simple yet effective model to validate the pathogenicity of missense variants.
Collapse
Affiliation(s)
- Caterina Ancora
- Pediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Marco Marchi
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy; Clinical Genetics Lab, Città della Speranza Pediatric Research Institute, Padua, Italy
| | - Claudia Maria Bonardi
- Pediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Geppo Sartori
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Daniela Zuccarello
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy
| | | | - Margherita Nosadini
- Pediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Stefano Sartori
- Pediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Clementina Boniver
- Pediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Irene Toldo
- Pediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy.
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padua, Padua, Italy; Clinical Genetics Lab, Città della Speranza Pediatric Research Institute, Padua, Italy
| |
Collapse
|
4
|
Rahman M, Ravichandran R, Sankpal NV, Bansal S, Sureshbabu A, Fleming T, Perincheri S, Bharat A, Smith MA, Bremner RM, Mohanakumar T. Downregulation of a tumor suppressor gene LKB1 in lung transplantation as a biomarker for chronic murine lung allograft rejection. Cell Immunol 2023; 386:104690. [PMID: 36812767 PMCID: PMC11019891 DOI: 10.1016/j.cellimm.2023.104690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023]
Abstract
BACKGROUND We recently demonstrated decreased tumor suppressor gene liver kinase B1 (LKB1) level in lung transplant recipients diagnosed with bronchiolitis obliterans syndrome. STE20-related adaptor alpha (STRADα) functions as a pseudokinase that binds and regulates LKB1 activity. METHODS A murine model of chronic lung allograft rejection in which a single lung from a B6D2F1 mouse was orthotopically transplanted into a DBA/2J mouse was employed. We examined the effect of LKB1 knockdown using CRISPR-CAS9 in vitro culture system. RESULTS Significant downregulation of LKB1 and STRADα expression was found in donor lung compared to recipient lung. STRADα knockdown significantly inhibited LKB1, pAMPK expression but induced phosphorylated mammalian target of rapamycin (mTOR), fibronectin, and Collagen-I, expression in BEAS-2B cells. LKB1 overexpression decreased fibronectin, Collagen-I, and phosphorylated mTOR expression in A549 cells. CONCLUSIONS We demonstrated that downregulation of LKB1-STRADα pathway accompanied with increased fibrosis, results in development of chronic rejection following murine lung transplantation.
Collapse
Affiliation(s)
- Mohammad Rahman
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | - Ranjithkumar Ravichandran
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | - Narendra V Sankpal
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | - Sandhya Bansal
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | - Angara Sureshbabu
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | - Timothy Fleming
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | | | - Ankit Bharat
- Northwestern University, Chicago, IL, United States
| | - Michael A Smith
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | - Ross M Bremner
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States
| | - T Mohanakumar
- Norton Thoracic Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, United States.
| |
Collapse
|
5
|
Hutson J, Siu VM, Rupar CA. Raisonnement clinique : L’hydramnios comme marqueur d’un syndrome génétique fœtal dans la population des mennonites du Vieil Ordre au Canada. Journal of Obstetrics and Gynaecology Canada 2022; 44:803-807. [DOI: 10.1016/j.jogc.2022.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 01/19/2022] [Indexed: 11/29/2022]
|
6
|
Siu VM, Hutson JR, Rupar CA. Clinical Conundrum: Polyhydramnios as a marker for a fetal genetic syndrome in the Canadian Old Order Mennonite population. Journal of Obstetrics and Gynaecology Canada 2022. [DOI: 10.1016/j.jogc.2022.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 10/19/2022]
|
7
|
Deb BK, Bateup HS. Modeling Somatic Mutations Associated With Neurodevelopmental Disorders in Human Brain Organoids. Front Mol Neurosci 2022; 14:787243. [PMID: 35058746 PMCID: PMC8764387 DOI: 10.3389/fnmol.2021.787243] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
Neurodevelopmental disorders (NDDs) are a collection of diseases with early life onset that often present with developmental delay, cognitive deficits, and behavioral conditions. In some cases, severe outcomes such as brain malformations and intractable epilepsy can occur. The mutations underlying NDDs may be inherited or de novo, can be gain- or loss-of-function, and can affect one or more genes. Recent evidence indicates that brain somatic mutations contribute to several NDDs, in particular malformations of cortical development. While advances in sequencing technologies have enabled the detection of these somatic mutations, the mechanisms by which they alter brain development and function are not well understood due to limited model systems that recapitulate these events. Human brain organoids have emerged as powerful models to study the early developmental events of the human brain. Brain organoids capture the developmental progression of the human brain and contain human-enriched progenitor cell types. Advances in human stem cell and genome engineering provide an opportunity to model NDD-associated somatic mutations in brain organoids. These organoids can be tracked throughout development to understand the impact of somatic mutations on early human brain development and function. In this review, we discuss recent evidence that somatic mutations occur in the developing human brain, that they can lead to NDDs, and discuss how they could be modeled using human brain organoids.
Collapse
Affiliation(s)
- Bipan K. Deb
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Helen S. Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States
- Chan Zuckerberg Biohub, San Francisco, CA, United States
- *Correspondence: Helen S. Bateup
| |
Collapse
|
8
|
Puffenberger EG. Mendelian disease research in the Plain populations of Lancaster County, Pennsylvania. Am J Med Genet A 2021; 185:3322-3333. [PMID: 34532947 DOI: 10.1002/ajmg.a.62489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/30/2021] [Accepted: 08/05/2021] [Indexed: 11/07/2022]
Abstract
Founder populations have long contributed to our knowledge of rare disease genes and phenotypes. From the pioneering work of Dr. Victor McKusick to today, research in these groups has shed light on rare recessive phenotypes, expanded the clinical spectrum of disease, and facilitated disease gene identification. Current clinical and research studies in these special groups augment the wealth of knowledge already gained, provide new insights into emerging problems such as variant interpretation and reduced penetrance, and contribute to the development of novel therapies for rare genetic diseases. Clinical developments over the past 30 years have altered the fundamental relationship with the Lancaster Plain communities: research has become more collaborative, and the knowledge imparted by these studies is now being harnessed to provide cutting-edge translational medicine to the very community of vulnerable individuals who need it most.
Collapse
|
9
|
Abstract
Malformations of cortical development (MCDs) represent a range of neurodevelopmental disorders that are collectively common causes of developmental delay and epilepsy, especially refractory childhood epilepsy. Initial treatment with antiseizure medications is empiric, and consideration of surgery is the standard of care for eligible patients with medically refractory epilepsy. In the past decade, advances in next generation sequencing technologies have accelerated progress in understanding the genetic etiologies of MCDs, and precision therapies for focal MCDs are emerging. Notably, mutations that lead to abnormal activation of the mammalian target of rapamycin (mTOR) pathway, which provides critical control of cell growth and proliferation, have emerged as a common cause of malformations. These include tuberous sclerosis complex (TSC), hemimegalencephaly (HME), and some types of focal cortical dysplasia (FCD). TSC currently represents the best example for the pathway from gene discovery to relatively safe and efficacious targeted therapy for epilepsy related to MCDs. Based on extensive pre-clinical and clinical data, the mTOR inhibitor everolimus is currently approved for the treatment of focal refractory seizures in patients with TSC. Although clinical studies are just emerging for FCD and HME, we believe the next decade will bring significant advancements in precision therapies for epilepsy related to these and other MCDs.
Collapse
Affiliation(s)
- Alissa M D'Gama
- Divisions of Newborn Medicine and Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA, USA
- Departments of Neurology and Pediatrics, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA, USA.
- Departments of Neurology and Pediatrics, Harvard Medical School, Boston, MA, USA.
- Broad Institute of Harvard and MIT, Cambridge, MA, USA.
| |
Collapse
|
10
|
Abstract
The mechanistic target of rapamycin (mTOR) is a kinase at the center of an evolutionarily conserved signaling pathway that orchestrates cell growth and metabolism. mTOR responds to an array of intra- and extracellular stimuli and in turn controls multiple cellular anabolic and catabolic processes. Aberrant mTOR activity is associated with numerous diseases, with particularly profound impact on the nervous system. mTOR is found in two protein complexes, mTOR complex 1 (mTORC1) and 2 (mTORC2), which are governed by different upstream regulators and have distinct cellular actions. Mutations in genes encoding for mTOR regulators result in a collection of neurodevelopmental disorders known as mTORopathies. While these disorders can affect multiple organs, neuropsychiatric conditions such as epilepsy, intellectual disability, and autism spectrum disorder have a major impact on quality of life. The neuropsychiatric aspects of mTORopathies have been particularly challenging to treat in a clinical setting. Current therapeutic approaches center on rapamycin and its analogs, drugs that are administered systemically to inhibit mTOR activity. While these drugs show some clinical efficacy, adverse side effects, incomplete suppression of mTOR targets, and lack of specificity for mTORC1 or mTORC2 may limit their utility. An increased understanding of the neurobiology of mTOR and the underlying molecular, cellular, and circuit mechanisms of mTOR-related disorders will facilitate the development of improved therapeutics. Animal models of mTORopathies have helped unravel the consequences of mTOR pathway mutations in specific brain cell types and developmental stages, revealing an array of disease-related phenotypes. In this review, we discuss current progress and potential future directions for the therapeutic treatment of mTORopathies with a focus on findings from genetic mouse models.
Collapse
Affiliation(s)
- Vasiliki Karalis
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| |
Collapse
|
11
|
Dang LT, Vaid S, Lin G, Swaminathan P, Safran J, Loughman A, Lee M, Glenn T, Majolo F, Crino PB, Parent JM. STRADA-mutant human cortical organoids model megalencephaly and exhibit delayed neuronal differentiation. Dev Neurobiol 2021; 81:696-709. [PMID: 33619909 DOI: 10.1002/dneu.22816] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 12/31/2022]
Abstract
Genetic diseases involving overactivation of the mechanistic target of rapamycin (mTOR) pathway, so-called "mTORopathies," often manifest with malformations of cortical development (MCDs), epilepsy, and cognitive impairment. How mTOR pathway hyperactivation results in abnormal human cortical development is poorly understood. To study the effect of mTOR hyperactivity on early stages of cortical development, we focused on Pretzel Syndrome (polyhydramnios, megalencephaly, symptomatic epilepsy; PMSE syndrome), a rare mTORopathy caused by homozygous germline mutations in the STRADA gene. We developed a human cortical organoid (hCO) model of PMSE and examined morphology and size for the first 2 weeks of organoid growth, and cell type composition at weeks 2, 8, and 12 of differentiation. In the second week, PMSE hCOs enlarged more rapidly than controls and displayed an abnormal Wnt pathway-dependent increase in neural rosette structures. PMSE hCOs also exhibited delayed neurogenesis, decreased subventricular zone progenitors, increased proliferation and cell death, and an abnormal architecture of primary cilia. At week 8, PMSE hCOs had fewer deep layer neurons. By week 12, neurogenesis recovered in PMSE organoids, but they displayed increased outer radial glia, a cell type thought to contribute to the expansion of the human cerebral cortex. Together, these findings suggest that megalencephaly in PMSE arises from the expansion of neural stem cells in early corticogenesis and potentially also from increased outer radial glial at later gestational stages. The delayed neuronal differentiation in PMSE organoids demonstrates the important role the mTOR pathway plays in the maintenance and expansion of the stem cell pool.
Collapse
Affiliation(s)
- Louis T Dang
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA.,Department of Neurology, Michigan Medicine, Ann Arbor, MI, USA.,Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, USA
| | - Shivanshi Vaid
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA.,Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, USA
| | - Grace Lin
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, USA.,Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, USA
| | | | - Jordan Safran
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Anna Loughman
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Monica Lee
- Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, USA
| | - Trevor Glenn
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, USA
| | - Fernanda Majolo
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, USA
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jack M Parent
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, USA.,Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, USA.,Neurology Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA
| |
Collapse
|
12
|
Abstract
Hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) due to mutations in genes along the PI3K-mTOR pathway and the GATOR1 complex causes a spectrum of neurodevelopmental disorders (termed mTORopathies) associated with malformation of cortical development and intractable epilepsy. Despite these gene variants’ converging impact on mTORC1 activity, emerging findings suggest that these variants contribute to epilepsy through both mTORC1-dependent and -independent mechanisms. Here, we review the literature on in utero electroporation-based animal models of mTORopathies, which recapitulate the brain mosaic pattern of mTORC1 hyperactivity, and compare the effects of distinct PI3K-mTOR pathway and GATOR1 complex gene variants on cortical development and epilepsy. We report the outcomes on cortical pyramidal neuronal placement, morphology, and electrophysiological phenotypes, and discuss some of the converging and diverging mechanisms responsible for these alterations and their contribution to epileptogenesis. We also discuss potential therapeutic strategies for epilepsy, beyond mTORC1 inhibition with rapamycin or everolimus, that could offer personalized medicine based on the gene variant.
Collapse
Affiliation(s)
- Lena H Nguyen
- Department of Neurosurgery, Yale School of Medicine, Yale University, New Haven, CT, United States.,Department of Cellular & Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Angélique Bordey
- Department of Neurosurgery, Yale School of Medicine, Yale University, New Haven, CT, United States.,Department of Cellular & Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States
| |
Collapse
|
13
|
Aerden M, Vallaeys L, Holvoet M, De Waele L, Van Den Bogaert K, Devriendt K. Homozygous missense STRADA mutation in a patient with polyhydramnios, megalencephaly and symptomatic epilepsy syndrome. Clin Dysmorphol 2021; 30:121-4. [PMID: 33605605 DOI: 10.1097/MCD.0000000000000368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Homozygous or compound heterozygous mutations in STRADA cause polyhydramnios, megalencephaly and symptomatic epilepsy syndrome (PMSE), with additional features of distinctive facial traits and severe developmental delay or intellectual disability. This syndrome was first defined in 16 Old Order Mennonite patients, carrying a homozygous STRADA deletion of exon 9-13. Five additional PMSE patients have been reported since, each of them with loss-of-function variants. We report a female patient with the typical clinical features of PMSE, homozygous for a novel STRADA missense mutation c.792T>A (p.Ser264Arg) in exon 10. This finding contributes to the further delineation of the phenotype of PMSE.
Collapse
|
14
|
Alsaif HS, Khashab HYEL, Alkuraya FS. Two further cases of polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome, caused by a truncating variant in STRADA. Am J Med Genet A 2020; 185:604-607. [PMID: 33247513 DOI: 10.1002/ajmg.a.61990] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/27/2020] [Accepted: 10/31/2020] [Indexed: 11/07/2022]
Affiliation(s)
- Hessa S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Heba Youssef E L Khashab
- Department of Pediatrics, Dr. Sulaiman Al-Habib Hospital, Riyadh, Saudi Arabia
- Department of Pediatrics, Division of Pediatric Neurology, Children's Hospital, Ain Shams University, Cairo, Egypt
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| |
Collapse
|
15
|
Affiliation(s)
- Peter B Crino
- Department of Neurology 12264University of Maryland School of Medicine
| |
Collapse
|
16
|
Dang LT, Glanowska KM, Iffland Ii PH, Barnes AE, Baybis M, Liu Y, Patino G, Vaid S, Streicher AM, Parker WE, Kim S, Moon UY, Henry FE, Murphy GG, Sutton M, Parent JM, Crino PB. Multimodal Analysis of STRADA Function in Brain Development. Front Cell Neurosci 2020; 14:122. [PMID: 32457579 PMCID: PMC7227375 DOI: 10.3389/fncel.2020.00122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 04/14/2020] [Indexed: 12/22/2022] Open
Abstract
mTORopathies are a heterogeneous group of neurological disorders characterized by malformations of cortical development (MCD), enhanced cellular mechanistic target of rapamycin (mTOR) signaling, and epilepsy that results from mutations in mTOR pathway regulatory genes. Homozygous mutations (del exon 9–13) in the pseudokinase STE20-related kinase adaptor alpha (STRAD-α; STRADA), an mTOR modulator, are associated with Pretzel Syndrome (PS), a neurodevelopmental disorder within the Old Order Mennonite Community characterized by megalencephaly, intellectual disability, and intractable epilepsy. To study the cellular mechanisms of STRADA loss, we generated CRISPR-edited Strada mouse N2a cells, a germline mouse Strada knockout (KO−/−) strain, and induced pluripotent stem cell (iPSC)-derived neurons from PS individuals harboring the STRADA founder mutation. Strada KO in vitro leads to enhanced mTOR signaling and iPSC-derived neurons from PS individuals exhibit enhanced cell size and mTOR signaling activation, as well as subtle alterations in electrical firing properties e.g., increased input resistance, a more depolarized resting membrane potential, and decreased threshold for action potential (AP) generation. Strada−/− mice exhibit high rates of perinatal mortality and out of more than 100 litters yielding both WT and heterozygous pups, only eight Strada−/− animals survived past P5. Strada−/− mice are hypotonic and tremulous. Histopathological examination (n = 5 mice) revealed normal gross brain organization and lamination but all had ventriculomegaly. Ectopic neurons were seen in all five Strada−/− brains within the subcortical white matter mirroring what is observed in human PS brain tissue. These distinct experimental platforms demonstrate that STRADA modulates mTOR signaling and is a key regulator of cell size, neuronal excitability, and cortical lamination.
Collapse
Affiliation(s)
- Louis T Dang
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, United States
| | - Katarzyna M Glanowska
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States
| | - Philip H Iffland Ii
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Allan E Barnes
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marianna Baybis
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Yu Liu
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States
| | - Gustavo Patino
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States
| | - Shivanshi Vaid
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Department of Pediatrics, Michigan Medicine, Ann Arbor, MI, United States
| | | | - Whitney E Parker
- Department of Neurosurgery, Weill-Cornell Medical Center, New York, NY, United States
| | - Seonhee Kim
- Louis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Uk Yeol Moon
- Louis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Frederick E Henry
- Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States.,Department of Molecular, and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
| | - Geoffrey G Murphy
- Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States.,Department of Molecular, and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
| | - Michael Sutton
- Michigan Neuroscience Institute, Michigan Medicine, Ann Arbor, MI, United States.,Department of Molecular, and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
| | - Jack M Parent
- Department of Neurology, Michigan Medicine, Ann Arbor, MI, United States.,Neurology Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, United States
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| |
Collapse
|
17
|
Jiang Q, Gu S. Sevoflurane Postconditioning Reduces Hypoxia-Reoxygenation Injury in H9C2 Embryonic Rat Cardiomyocytes and Targets the STRADA Gene by Upregulating microRNA-107. Med Sci Monit 2020; 26:e920849. [PMID: 32332694 PMCID: PMC7197225 DOI: 10.12659/msm.920849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Sevoflurane as a widely used inhalational general anesthetic that also has a cardioprotective role in hypoxia-reoxygenation (H/R) injury. This study aimed to investigate the effects of microRNA-107 (miR-107) on sevoflurane postconditioning (SpostC) in H9C2 embryonic rat cardiomyocytes and to use bioinformatics analysis to identify the molecular basis of cardioprotection from sevoflurane in human cardiac tissue. MATERIAL AND METHODS The STRADA gene was identified from the Gene Expression Omnibus (GEO) database. H9C2 embryonic rat cardiomyocytes were cultured with sevoflurane. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to measure the mRNA expression and protein expression of STRADA and miR-107 in H9C2 cells. TargetScanHuman version 7.2 was used to identify the target gene of miR-107 and to predict the STRADA 3'-UTR binding site of miR-107. The dual-luciferase reporter assay measured the relative luciferase activity. The cell proliferation rate and cell apoptosis were measured using the MTT assay and flow cytometry, respectively. RESULTS H/R injury in H9C2 cells following SpostC resulted in increased expression of miR-107 and reduced expression of STRADA. Specific binding of miR-107 was identified to STRADA 3'-UTR. Upregulation of the miR-107 in SpostC H/R injured H9C2 cells promoted cell proliferation, reduced cell apoptosis, and downregulating the protein expression of caspase-3. STRADA overexpression reduced the effects of a miR-107 mimic on SpostC. CONCLUSIONS SpostC reduced H/R injury in H9C2 embryonic rat cardiomyocytes by targeting the STRADA gene and by upregulating the expression of microRNA-107.
Collapse
Affiliation(s)
- Qun Jiang
- Department of Pain Medicine, Affiliated Hospital of Jianghan University, Wuhan, Hubei, China (mainland)
| | - Shan Gu
- Department of Anesthesiology, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, Hubei, China (mainland).,Hubei Province Academy of Traditional Chinese Medicine, Wuhan, Hubei, China (mainland)
| |
Collapse
|
18
|
Abstract
The mTOR pathway integrates a diverse set of environmental cues, such as growth factor signals and nutritional status, to direct eukaryotic cell growth. Over the past two and a half decades, mapping of the mTOR signalling landscape has revealed that mTOR controls biomass accumulation and metabolism by modulating key cellular processes, including protein synthesis and autophagy. Given the pathway's central role in maintaining cellular and physiological homeostasis, dysregulation of mTOR signalling has been implicated in metabolic disorders, neurodegeneration, cancer and ageing. In this Review, we highlight recent advances in our understanding of the complex regulation of the mTOR pathway and discuss its function in the context of physiology, human disease and pharmacological intervention.
Collapse
Affiliation(s)
- Grace Y Liu
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute, Cambridge, MA, USA
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Broad Institute, Cambridge, MA, USA.
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA, USA.
| |
Collapse
|
19
|
Abstract
Development of the central nervous system (CNS) is a complex, dynamic process that involves a precisely orchestrated sequence of genetic, environmental, biochemical, and physical factors from early embryonic stages to postnatal life. Duringthe past decade, great strides have been made to unravel mechanisms underlying human CNS development through the employment of modern genetic techniques and experimental approaches. In this chapter, we review the current knowledge regarding the main developmental processes and signaling mechanisms of (i) neurogenesis, (ii) neuronal migration, and (iii) axon guidance. We discuss mechanisms related to neural stem cells proliferation, migration, terminal translocation of neuronal progenitors, and axon guidance and pathfinding. For each section, we also provide a comprehensive overview of the underlying regulatory processes, including transcriptional, posttranscriptional, and epigenetic factors, and a myriad of signaling pathways that are pivotal to determine the fate of neuronal progenitors and newly formed migrating neurons. We further highlight how impairment of this complex regulating system, such as mutations in its core components, may cause cortical malformation, epilepsy, intellectual disability, and autism in humans. A thorough understanding of normal human CNS development is thus crucial to decipher mechanisms responsible for neurodevelopmental disorders and in turn guide the development of effective and targeted therapeutic strategies.
Collapse
Affiliation(s)
- Andrea Accogli
- Unit of Medical Genetics, Istituto Giannina Gaslini Pediatric Hospital, Genova, Italy; Departments of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal-Child Science, Università degli Studi di Genova, Genova, Italy
| | | | - Myriam Srour
- Research Institute, McGill University Health Centre, Montreal, QC, Canada; Department of Pediatrics, Division of Pediatric Neurology, McGill University, Montreal, QC, Canada.
| |
Collapse
|
20
|
Caracci MO, Fuentealba LM, Marzolo MP. Golgi Complex Dynamics and Its Implication in Prevalent Neurological Disorders. Front Cell Dev Biol 2019; 7:75. [PMID: 31134199 PMCID: PMC6514153 DOI: 10.3389/fcell.2019.00075] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 04/18/2019] [Indexed: 12/13/2022] Open
Abstract
Coupling of protein synthesis with protein delivery to distinct subcellular domains is essential for maintaining cellular homeostasis, and defects thereof have consistently been shown to be associated with several diseases. This function is particularly challenging for neurons given their polarized nature and differential protein requirements in synaptic boutons, dendrites, axons, and soma. Long-range trafficking is greatly enhanced in neurons by discrete mini-organelles resembling the Golgi complex (GC) referred to as Golgi outposts (GOPs) which play an essential role in the development of dendritic arborization. In this context, the morphology of the GC is highly plastic, and the polarized distribution of this organelle is necessary for neuronal migration and polarized growth. Furthermore, synaptic components are readily trafficked and modified at GOP suggesting a function for this organelle in synaptic plasticity. However, little is known about GOPs properties and biogenesis and the role of GOP dysregulation in pathology. In this review, we discuss current literature supporting a role for GC dynamics in prevalent neurological disorders such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and epilepsy, and examine the association of these disorders with the wide-ranging effects of GC function on common cellular pathways regulating neuronal excitability, polarity, migration, and organellar stress. First, we discuss the role of Golgins and Golgi-associated proteins in the regulation of GC morphology and dynamics. Then, we consider abnormal GC arrangements observed in neurological disorders and associations with common neuronal defects therein. Finally, we consider the cell signaling pathways involved in the modulation of GC dynamics and argue for a master regulatory role for Reelin signaling, a well-known regulator of neuronal polarity and migration. Determining the cellular pathways involved in shaping the Golgi network will have a direct and profound impact on our current understanding of neurodevelopment and neuropathology and aid the development of novel therapeutic strategies for improved patient care and prognosis.
Collapse
Affiliation(s)
- Mario O Caracci
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luz M Fuentealba
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María-Paz Marzolo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
21
|
Crowgey EL, Washburn MC, Kolb EA, Puffenberger EG. Development of a Novel Next-Generation Sequencing Assay for Carrier Screening in Old Order Amish and Mennonite Populations of Pennsylvania. J Mol Diagn 2019; 21:687-694. [PMID: 31028937 PMCID: PMC7338886 DOI: 10.1016/j.jmoldx.2019.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/15/2019] [Accepted: 03/13/2019] [Indexed: 11/25/2022] Open
Abstract
Genetically isolated populations, such as the Old Order Amish and Old Order Mennonite communities, have an increased incidence of specific autosomal recessive disorders caused by the founder effect. In these populations, robust expanded carrier screening and diagnostic testing have the potential to reduce overall medical costs and improve patient outcomes. A novel next-generation sequencing assay was developed using anchored multiplex PCR technology (ArcherDX) for 162 different genetic syndromes caused by 202 pathogenic variants consisting of 150 single-nucleotide changes, 43 small insertion/deletions, and 9 large deletions (>20 nucleotides). To assess the accuracy of the screening panel results, 48 samples were selected on the basis of prior whole exome sequencing results. An additional 15 samples were chosen specifically to validate SMN1 and SMN2 copy number analyses. Collectively, the screening panel detected 273 pathogenic single-nucleotide or small insertion/deletion variants, 35 copy number variations, and 1 chromosomal abnormality (Klinefelter syndrome). Concordance with prior whole exome sequencing was 100%. By using a novel next-generation sequencing workflow, a successful targeted gene variant panel was developed for the Old Order Amish and Old Order Mennonite populations of Lancaster County, Pennsylvania. Population-wide carrier screening may help decrease the morbidity and mortality of these conditions in the high-risk populations.
Collapse
Affiliation(s)
- Erin L Crowgey
- Nemours Biomedical Research Department, Nemours Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | | | - E Anders Kolb
- Nemours Biomedical Research Department, Nemours Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | | |
Collapse
|
22
|
Mühlebner A, Bongaarts A, Sarnat HB, Scholl T, Aronica E. New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives. J Anat 2019; 235:521-542. [PMID: 30901081 DOI: 10.1111/joa.12956] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2019] [Indexed: 12/20/2022] Open
Abstract
In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.
Collapse
Affiliation(s)
- A Mühlebner
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - A Bongaarts
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, AB, Canada
| | - T Scholl
- Department of Paediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - E Aronica
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Amsterdam, The Netherlands
| |
Collapse
|
23
|
Rasika S, Passemard S, Verloes A, Gressens P, El Ghouzzi V. Golgipathies in Neurodevelopment: A New View of Old Defects. Dev Neurosci 2019; 40:396-416. [PMID: 30878996 DOI: 10.1159/000497035] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 01/16/2019] [Indexed: 11/19/2022] Open
Abstract
The Golgi apparatus (GA) is involved in a whole spectrum of activities, from lipid biosynthesis and membrane secretion to the posttranslational processing and trafficking of most proteins, the control of mitosis, cell polarity, migration and morphogenesis, and diverse processes such as apoptosis, autophagy, and the stress response. In keeping with its versatility, mutations in GA proteins lead to a number of different disorders, including syndromes with multisystem involvement. Intriguingly, however, > 40% of the GA-related genes known to be associated with disease affect the central or peripheral nervous system, highlighting the critical importance of the GA for neural function. We have previously proposed the term "Golgipathies" in relation to a group of disorders in which mutations in GA proteins or their molecular partners lead to consequences for brain development, in particular postnatal-onset microcephaly (POM), white-matter defects, and intellectual disability (ID). Here, taking into account the broader role of the GA in the nervous system, we refine and enlarge this emerging concept to include other disorders whose symptoms may be indicative of altered neurodevelopmental processes, from neurogenesis to neuronal migration and the secretory function critical for the maturation of postmitotic neurons and myelination.
Collapse
Affiliation(s)
- Sowmyalakshmi Rasika
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Sandrine Passemard
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Alain Verloes
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,AP HP, Hôpital Robert Debré, UF de Génétique Clinique, Paris, France
| | - Pierre Gressens
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Vincent El Ghouzzi
- NeuroDiderot, INSERM UMR1141, Université Paris Diderot, Sorbonne Paris Cité, Paris, France,
| |
Collapse
|
24
|
Xu Q, Uliel-Sibony S, Dunham C, Sarnat H, Flores-Sarnat L, Brunga L, Davidson S, Lo W, Shlien A, Connolly M, Boelman C, Datta A. mTOR Inhibitors as a New Therapeutic Strategy in Treatment Resistant Epilepsy in Hemimegalencephaly: A Case Report. J Child Neurol 2019; 34:132-138. [PMID: 30514132 DOI: 10.1177/0883073818813238] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Hemimegalencephaly is a hamartomatous malformation of one hemisphere. Functional hemispherectomy, the definitive treatment, is associated with significant morbidity and mortality in early infancy. Dysregulation of the mTOR pathway can result in malformations of cortical development, and mTOR inhibitors can effectively reduce seizures in tuberous sclerosis complex. We report a 6-day-old female with hemimegalencephaly and frequent seizures despite 9 antiseizure medications. At 3 months of age, while awaiting hemispherectomy, an mTOR inhibitor, rapamycin, was initiated by the neurologist. After 1 week of treatment, there was >50% reduction in seizures and total seizure burden, and after 2 weeks, development improved, resulting in deferral of surgery by 2.5 months with an increased body weight. Pathology demonstrated cortical dysplasia with upregulation of the mTOR pathway. Deep-sequencing of brain tissue demonstrated 16% mosaicism for a pathogenic de novo MTOR gene mutation. This case exemplifies how mTOR inhibitors could be considered for seizure reduction in patients with hemimegalencephaly while awaiting surgery.
Collapse
Affiliation(s)
- Qi Xu
- 1 Division of Neurology, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| | - Shimrit Uliel-Sibony
- 1 Division of Neurology, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| | - Christopher Dunham
- 2 Department of Pathology, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| | - Harvey Sarnat
- 3 Division of Pediatric Neurology, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada
| | - Laura Flores-Sarnat
- 3 Division of Pediatric Neurology, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada
| | - Ledia Brunga
- 4 University of Toronto, Program in Genetics and Genome Biology, the Hospital for Sick Children, Toronto, ON, Canada
| | - Scott Davidson
- 4 University of Toronto, Program in Genetics and Genome Biology, the Hospital for Sick Children, Toronto, ON, Canada
| | - Winnie Lo
- 4 University of Toronto, Program in Genetics and Genome Biology, the Hospital for Sick Children, Toronto, ON, Canada
| | - Adam Shlien
- 4 University of Toronto, Program in Genetics and Genome Biology, the Hospital for Sick Children, Toronto, ON, Canada
| | - Mary Connolly
- 1 Division of Neurology, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| | - Cyrus Boelman
- 1 Division of Neurology, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| | - Anita Datta
- 1 Division of Neurology, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| |
Collapse
|
25
|
Abstract
Malformations of cortical development encompass heterogeneous groups of structural brain anomalies associated with complex neurodevelopmental disorders and diverse genetic and nongenetic etiologies. Recent progress in understanding the genetic basis of brain malformations has been driven by extraordinary advances in DNA sequencing technologies. For example, somatic mosaic mutations that activate mammalian target of rapamycin signaling in cortical progenitor cells during development are now recognized as the cause of hemimegalencephaly and some types of focal cortical dysplasia. In addition, research on brain development has begun to reveal the cellular and molecular bases of cortical gyrification and axon pathway formation, providing better understanding of disorders involving these processes. New neuroimaging techniques with improved resolution have enhanced our ability to characterize subtle malformations, such as those associated with intellectual disability and autism. In this review, we broadly discuss cortical malformations and focus on several for which genetic etiologies have elucidated pathogenesis.
Collapse
Affiliation(s)
- Gordana Juric-Sekhar
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington 98195, USA; ,
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195, USA
| | - Robert F Hevner
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington 98195, USA; ,
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195, USA
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington 98105, USA
- Current affiliation: Department of Pathology, University of California, San Diego, California 92093, USA
| |
Collapse
|
26
|
Dixit AB, Sharma D, Tripathi M, Srivastava A, Paul D, Prakash D, Sarkar C, Kumar K, Banerjee J, Chandra PS. Genome-wide DNA Methylation and RNAseq Analyses Identify Aberrant Signalling Pathways in Focal Cortical Dysplasia (FCD) Type II. Sci Rep 2018; 8:17976. [PMID: 30568293 PMCID: PMC6299275 DOI: 10.1038/s41598-018-35892-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/01/2018] [Indexed: 01/26/2023] Open
Abstract
Focal cortical dysplasia (FCD) is one of the most common pathologies associated with drug-resistant epilepsy (DRE). The pharmacological targets remain obscured, as the molecular mechanisms underlying FCD are unclear. Implications of epigenetically modulated aberrant gene expression in disease progression are reported in various DRE pathologies except FCD. Here we performed genome-wide CpG-DNA methylation profiling by methylated DNA immunoprecipitation (MeDIP) microarray and RNA sequencing (RNAseq) on cortical tissues resected from FCD type II patients. A total of 19088 sites showed altered DNA methylation in all the CpG islands. Of these, 5725 sites were present in the promoter regions, of which 176 genes showed an inverse correlation between methylation and gene expression. Many of these 176 genes were found to belong to a cohesive network of physically interacting proteins linked to several cellular functions. Pathway analysis revealed significant enrichment of receptor tyrosine kinases (RTK), EGFR, PDGFRA, NTRK3, and mTOR signalling pathways. This is the first study that investigates the epigenetic signature associated with FCD type II pathology. The candidate genes and pathways identified in this study may play a crucial role in the regulation of the pathogenic mechanisms of epileptogenesis associated with FCD type II pathologies.
Collapse
Affiliation(s)
- Aparna Banerjee Dixit
- Center of Excellence for Epilepsy, A joint NBRC-AIIMS collaboration, NBRC, Manesar, India. .,Dr. B R Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India.
| | - Devina Sharma
- Center of Excellence for Epilepsy, A joint NBRC-AIIMS collaboration, NBRC, Manesar, India.,Department of Neurosurgery, AIIMS, New Delhi, India
| | - Manjari Tripathi
- Center of Excellence for Epilepsy, A joint NBRC-AIIMS collaboration, NBRC, Manesar, India.,Department of Neurology, AIIMS, New Delhi, India
| | | | - Debasmita Paul
- Center of Excellence for Epilepsy, A joint NBRC-AIIMS collaboration, NBRC, Manesar, India.,Department of Neurosurgery, AIIMS, New Delhi, India
| | - Deepak Prakash
- Department of Forensic Medicine and Toxicology, AIIMS, New Delhi, India
| | | | - Krishan Kumar
- Center of Excellence for Epilepsy, A joint NBRC-AIIMS collaboration, NBRC, Manesar, India.,Department of Neurosurgery, AIIMS, New Delhi, India
| | - Jyotirmoy Banerjee
- Center of Excellence for Epilepsy, A joint NBRC-AIIMS collaboration, NBRC, Manesar, India.,Department of Biophysics, AIIMS, New Delhi, India
| | - P Sarat Chandra
- Center of Excellence for Epilepsy, A joint NBRC-AIIMS collaboration, NBRC, Manesar, India. .,Department of Neurosurgery, AIIMS, New Delhi, India.
| |
Collapse
|
27
|
Nelson K, Jackman C, Bell J, Shih CS, Payne K, Dlouhy S, Walsh L. Novel Homozygous Deletion in STRADA Gene Associated With Polyhydramnios, Megalencephaly, and Epilepsy in 2 Siblings: Implications for Diagnosis and Treatment. J Child Neurol 2018; 33:925-929. [PMID: 30311510 DOI: 10.1177/0883073818802724] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mutations in the STE20-related kinase adaptor α ( STRADA) gene have been reported to cause an autosomal recessive neurodevelopmental disorder characterized by infantile-onset epilepsy, developmental delay, and craniofacial dysmorphisms. To date, there have been 17 reported individuals diagnosed with STRADA mutations, 16 of which are from a single Old Order Mennonite cohort and share a deletion of exons 9-13. The remaining individual is of consanguineous Indian descent and has a homozygous single-base pair duplication. We report a novel STRADA gene deletion of exons 7-9 in 2 sisters from nonconsanguineous parents, as well as an improvement in seizure control in 1 sibling following treatment with sirolimus, an m-Tor inhibitor of potential benefit to patients with this genetic mutation.
Collapse
Affiliation(s)
- Katherine Nelson
- 1 Department of Medical and Molecular Genetics, Indiana University Health, Indianapolis, IN, USA
| | - Christopher Jackman
- 2 Department of Neurology, Division of Child Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jennifer Bell
- 3 Department of Pediatric Oncology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chie-Schin Shih
- 4 Department of Pediatrics, Division of Hematology/Oncology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Katelyn Payne
- 2 Department of Neurology, Division of Child Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Stephen Dlouhy
- 5 Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Laurence Walsh
- 2 Department of Neurology, Division of Child Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| |
Collapse
|
28
|
Abstract
The technological advancement of next-generation sequencing has greatly accelerated the pace of variant discovery in epilepsy. Despite an initial focus on autosomal dominant epilepsy due to the tractable nature of variant discovery with trios under a de novo model, more and more variants are being reported in families with epilepsies consistent with autosomal recessive (AR) inheritance. In this review, we touch on the classical AR epilepsy variants such as the inborn errors of metabolism and malformations of cortical development. However, we also highlight recently reported genes that are being identified by next-generation sequencing approaches and online 'matchmaking' platforms. Syndromes mainly characterized by seizures and complex neurodevelopmental disorders comorbid with epilepsy are discussed as an example of the wide phenotypic spectrum associated with the AR epilepsies. We conclude with a foray into the future, from the application of whole-genome sequencing to identify elusive epilepsy variants, to the promise of precision medicine initiatives to provide novel targeted therapeutics specific to the individual based on their clinical genetic testing.
Collapse
Affiliation(s)
- Jeffrey D Calhoun
- a Department of Neurology , Northwestern University Feinberg School of Medicine , Chicago , IL , USA
| | - Gemma L Carvill
- a Department of Neurology , Northwestern University Feinberg School of Medicine , Chicago , IL , USA
| |
Collapse
|
29
|
Sun R, Cui G, Chen Y, Shu B, Zhong G, Yi X. Proteomic Profiling Analysis of Male Infertility in Spodoptera Litura
Larvae Challenged with Azadirachtin and its Potential-Regulated Pathways in the Following Stages. Proteomics 2018; 18:e1800192. [DOI: 10.1002/pmic.201800192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/28/2018] [Indexed: 01/03/2023]
Affiliation(s)
- Ranran Sun
- Key Laboratory of Natural Pesticide and Chemical Biology; Ministry of Education; South China Agricultural University; Guangzhou P. R. China
- Key Laboratory of Crop Integrated Pest Management in South China; Ministry of Agriculture; South China Agricultural University; Guangzhou P. R. China
| | - Gaofeng Cui
- Key Laboratory of Natural Pesticide and Chemical Biology; Ministry of Education; South China Agricultural University; Guangzhou P. R. China
- Key Laboratory of Crop Integrated Pest Management in South China; Ministry of Agriculture; South China Agricultural University; Guangzhou P. R. China
| | - Yaoyao Chen
- Key Laboratory of Natural Pesticide and Chemical Biology; Ministry of Education; South China Agricultural University; Guangzhou P. R. China
- Key Laboratory of Crop Integrated Pest Management in South China; Ministry of Agriculture; South China Agricultural University; Guangzhou P. R. China
| | - Benshui Shu
- Key Laboratory of Natural Pesticide and Chemical Biology; Ministry of Education; South China Agricultural University; Guangzhou P. R. China
- Key Laboratory of Crop Integrated Pest Management in South China; Ministry of Agriculture; South China Agricultural University; Guangzhou P. R. China
| | - Guohua Zhong
- Key Laboratory of Natural Pesticide and Chemical Biology; Ministry of Education; South China Agricultural University; Guangzhou P. R. China
- Key Laboratory of Crop Integrated Pest Management in South China; Ministry of Agriculture; South China Agricultural University; Guangzhou P. R. China
| | - Xin Yi
- Key Laboratory of Natural Pesticide and Chemical Biology; Ministry of Education; South China Agricultural University; Guangzhou P. R. China
- Key Laboratory of Crop Integrated Pest Management in South China; Ministry of Agriculture; South China Agricultural University; Guangzhou P. R. China
| |
Collapse
|
30
|
Abstract
Nearly a third of patients with epilepsy have seizures refractory to current medical therapies. In the search for novel drug targets, the mTOR pathway has emerged as key in the regulation of neuronal function, growth and survival, and other cellular processes related to epileptogenesis. Hyperactivation of the mTOR pathway has been implicated in tuberous sclerosis complex and other 'mTORopathies', clinical syndromes associated with cortical developmental malformations and drug-resistant epilepsy. Recently published clinical trials of mTOR inhibitors in tuberous sclerosis complex have shown that these drugs are effective at decreasing seizure frequency. Future studies may establish whether mTOR inhibitors can provide effective treatment for patients with diverse genetic and acquired epilepsies, including preventative, disease-modifying therapies.
Collapse
Affiliation(s)
- Jennifer L Griffith
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
31
|
Salpietro V, Perez-Dueñas B, Nakashima K, San Antonio-Arce V, Manole A, Efthymiou S, Vandrovcova J, Bettencourt C, Mencacci NE, Klein C, Kelly MP, Davies CH, Kimura H, Macaya A, Houlden H. A homozygous loss-of-function mutation in PDE2A associated to early-onset hereditary chorea. Mov Disord 2018; 33:482-488. [PMID: 29392776 PMCID: PMC5873427 DOI: 10.1002/mds.27286] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/01/2017] [Accepted: 12/04/2017] [Indexed: 01/05/2023] Open
Abstract
Background: We investigated a family that presented with an infantile‐onset chorea‐predominant movement disorder, negative for NKX2‐1, ADCY5, and PDE10A mutations. Methods: Phenotypic characterization and trio whole‐exome sequencing was carried out in the family. Results: We identified a homozygous mutation affecting the GAF‐B domain of the 3’,5’‐cyclic nucleotide phosphodiesterase PDE2A gene (c.1439A>G; p.Asp480Gly) as the candidate novel genetic cause of chorea in the proband. PDE2A hydrolyzes cyclic adenosine/guanosine monophosphate and is highly expressed in striatal medium spiny neurons. We functionally characterized the p.Asp480Gly mutation and found that it severely decreases the enzymatic activity of PDE2A. In addition, we showed equivalent expression in human and mouse striatum of PDE2A and its homolog gene, PDE10A. Conclusions: We identified a loss‐of‐function homozygous mutation in PDE2A associated to early‐onset chorea. Our findings possibly strengthen the role of cyclic adenosine monophosphate and cyclic guanosine monophosphate metabolism in striatal medium spiny neurons as a crucial pathophysiological mechanism in hyperkinetic movement disorders. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Vincenzo Salpietro
- Department of Molecular Neuroscience, University College of London, London, United Kingdom
| | - Belen Perez-Dueñas
- Department of Pediatric Neurology, Hospital Universitari Sant Joan de Déu, Barcelona, Spain
| | - Kosuke Nakashima
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Victoria San Antonio-Arce
- Unit of Epilepsy, Sleep and Neurophysiology, Hospital Universitari Sant Joan de Déu, Barcelona, Spain
| | - Andreea Manole
- Department of Molecular Neuroscience, University College of London, London, United Kingdom
| | - Stephanie Efthymiou
- Department of Molecular Neuroscience, University College of London, London, United Kingdom
| | - Jana Vandrovcova
- Department of Molecular Neuroscience, University College of London, London, United Kingdom
| | - Conceicao Bettencourt
- Department of Molecular Neuroscience, University College of London, London, United Kingdom
| | - Niccolò E Mencacci
- Department of Molecular Neuroscience, University College of London, London, United Kingdom.,Center for Genetic Medicine, Feinberg school of medicine, Northwestern University, Chicago, Illinois, USA
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Michy P Kelly
- Department of Pharmacology, Physiology and Neuroscience, School of Medicine, University of South Carolina, Columbia, South Carolina, USA
| | - Ceri H Davies
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Haruhide Kimura
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Alfons Macaya
- Department of Pediatric Neurology, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Henry Houlden
- Department of Molecular Neuroscience, University College of London, London, United Kingdom
| |
Collapse
|
32
|
Affiliation(s)
- Paolo Curatolo
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University Hospital, Rome, Italy
| | - Romina Moavero
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University Hospital, Rome, Italy
- Child Neurology Unit, Neuroscience and Neurorehabilitation Department, “Bambino Gesù” Children’s Hospital, IRCCS, Rome, Italy
| | - Jackelien van Scheppingen
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), The Netherlands
| |
Collapse
|
33
|
Abstract
Malformations of cortical development represent a common cause of epileptic encephalopathies and drug-resistant epilepsy in children. As current treatments are often ineffective, new therapeutic targets are needed for epileptic encephalopathies associated with cortical malformations. The mechanistic/mammalian target of rapamycin (mTOR) pathway constitutes a signaling pathway that drives cellular and molecular mechanisms of epileptogenesis in a variety of focal cortical malformations. mTOR inhibitors prevent epilepsy and associated pathogenic mechanisms of epileptogenesis in mouse models of tuberous sclerosis complex and are currently in clinical trials for drug-resistant seizures in these patients. A recent explosion of genetic studies has linked mutations in various genes regulating the mTOR pathway to other cortical malformations, such as focal cortical dysplasia and hemimegalencephaly. Thus, mTOR inhibitors represent promising candidates as novel antiseizure and antiepileptogenic therapies for epilepsy associated with a spectrum of cortical malformations.
Collapse
Affiliation(s)
- Anna Jeong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
34
|
Rao S, Kirschen GW, Szczurkowska J, Di Antonio A, Wang J, Ge S, Shelly M. Repositioning of Somatic Golgi Apparatus Is Essential for the Dendritic Establishment of Adult-Born Hippocampal Neurons. J Neurosci 2018; 38:631-47. [PMID: 29217690 DOI: 10.1523/JNEUROSCI.1217-17.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 10/02/2017] [Accepted: 10/29/2017] [Indexed: 01/22/2023] Open
Abstract
New dentate granule cells (DGCs) are continuously generated, and integrate into the preexisting hippocampal network in the adult brain. How an adult-born neuron with initially simple spindle-like morphology develops into a DGC, consisting of a single apical dendrite with further branches, remains largely unknown. Here, using retroviruses to birth date and manipulate newborn neurons, we examined initial dendritic formation and possible underlying mechanisms. We found that GFP-expressing newborn cells began to establish a DGC-like morphology at ∼7 d after birth, with a primary dendrite pointing to the molecular layer, but at this stage, with several neurites in the neurogenic zone. Interestingly, the Golgi apparatus, an essential organelle for neurite growth and maintenance, was dynamically repositioning in the soma of newborn cells during this initial integration stage. Two weeks after birth, by which time most neurites in the neurogenic zone were eliminated, a compact Golgi apparatus was positioned exclusively at the base of the primary dendrite. We analyzed the presence of Golgi-associated genes using single-cell transcriptomes of newborn DGCs, and among Golgi-related genes, found the presence of STK25 and STRAD, regulators of embryonic neuronal development. When we knocked down either of these two proteins, we found Golgi mislocalization and extensive aberrant dendrite formation. Furthermore, overexpression of a mutated form of STRAD, underlying the disorder polyhydramnios, megalencephaly, and symptomatic epilepsy, characterized by abnormal brain development and intractable epilepsy, caused similar defects in Golgi localization and dendrite formation in adult-born neurons. Together, our findings reveal a role for Golgi repositioning in regulating the initial integration of adult-born DGCs.SIGNIFICANCE STATEMENT Since the discovery of the continuous generation of new neurons in the adult hippocampus, extensive effort was directed toward understanding the functional contribution of these newborn neurons to the existing hippocampal circuit and associated behaviors, while the molecular mechanisms controlling their early morphological integration are less well understood. Dentate granule cells (DGCs) have a single, complex, apical dendrite. The events leading adult-born DGCs' to transition from simple spindle-like morphology to mature dendrite morphology are largely unknown. We studied establishment of newborn DGCs dendritic pattern and found it was mediated by a signaling pathway regulating precise localization of the Golgi apparatus. Furthermore, this Golgi-associated mechanism for dendrite establishment might be impaired in a human genetic epilepsy syndrome, polyhydramnios, megalencephaly, and symptomatic epilepsy.
Collapse
|
35
|
Evers C, Staufner C, Granzow M, Paramasivam N, Hinderhofer K, Kaufmann L, Fischer C, Thiel C, Opladen T, Kotzaeridou U, Wiemann S, Schlesner M, Eils R, Kölker S, Bartram CR, Hoffmann GF, Moog U. Impact of clinical exomes in neurodevelopmental and neurometabolic disorders. Mol Genet Metab 2017; 121:297-307. [PMID: 28688840 DOI: 10.1016/j.ymgme.2017.06.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/29/2017] [Accepted: 06/29/2017] [Indexed: 01/06/2023]
Abstract
Whole exome sequencing (WES) is well established in research and is now being introduced into clinically indicated diagnostics (so-called clinical exomes). We evaluated the diagnostic yield and clinical implications of WES in 72 patients from 60 families with undiagnosed neurodevelopmental disorders (NDD), neurometabolic disorders, and dystonias. Pathogenic or likely pathogenic variants leading to a molecular diagnosis could be identified in 21 of the 60 families (overall 35%, in 36% of patients with NDD, in 43% of patients with neurometabolic disorders, in 25% of patients with dystonias). In one family two coexisting autosomal recessive diseases caused by homozygous pathogenic variants in two different genes were diagnosed. In another family, a homozygous frameshift variant in STRADA was found to cause a severe NDD with early onset epilepsy, brain anomalies, hypotonia, heart defect, nephrocalcinosis, macrocephaly and distinctive facies so far designated as PMSE (polyhydramnios, megalencephaly, symptomatic epilepsy) syndrome. In 7 of the 21 families with a molecular diagnosis the pathogenic variants were only identified by clinical follow-up, manual reevaluation of the literature, a change of filter setting, and/or reconsideration of inheritance pattern. Most importantly, clinical implications included management changes in 8 cases and impact on family planning in 20 families with a molecular diagnosis. This study shows that reevaluation and follow-up can improve the diagnostic rate and that WES results have important implications on medical management and family planning. Furthermore, we could confirm STRADA as a gene associated with syndromic ID but find it questionable if the current designation as PMSE depicts the most important clinical features.
Collapse
Affiliation(s)
- Christina Evers
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany.
| | - Christian Staufner
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Martin Granzow
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Nagarajan Paramasivam
- Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany; Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Katrin Hinderhofer
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Lilian Kaufmann
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Christine Fischer
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Christian Thiel
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Thomas Opladen
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Urania Kotzaeridou
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Stefan Wiemann
- Genomics & Proteomics Core Facility, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120 Heidelberg, Germany
| | - Matthias Schlesner
- Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Roland Eils
- Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Department for Bioinformatics and Functional Genomics, Institute for Pharmacy and Molecular Biotechnology (IPMB) and BioQuant, Heidelberg University, 69120 Heidelberg, Germany
| | - Stefan Kölker
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Claus R Bartram
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Georg F Hoffmann
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Ute Moog
- Institute of Human Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| |
Collapse
|
36
|
Pavone P, Praticò AD, Rizzo R, Corsello G, Ruggieri M, Parano E, Falsaperla R. A clinical review on megalencephaly: A large brain as a possible sign of cerebral impairment. Medicine (Baltimore) 2017; 96:e6814. [PMID: 28658095 PMCID: PMC5500017 DOI: 10.1097/md.0000000000006814] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 02/23/2017] [Accepted: 02/27/2017] [Indexed: 11/26/2022] Open
Abstract
Megalencephaly and macrocephaly present with a head circumference measurement 2 standard deviations above the age-related mean. However, even if pathologic events resulting in both megalencephaly and macrocephaly may coexist, a distinction between these two entities is appropriate, as they represent clinical expression of different disorders with a different approach in clinical work-up, overall prognosis, and treatment. Megalencephaly defines an increased growth of cerebral structures related to dysfunctional anomalies during the various steps of brain development in the neuronal proliferation and/or migration phases or as a consequence of postnatal abnormal events. The disorders associated with megalencephaly are classically defined into 3 groups: idiopathic or benign, metabolic, and anatomic. In this article, we seek to underline the clinical aspect of megalencephaly, emphasizing the main disorders that manifest with this anomaly in an attempt to properly categorize these disorders within the megalencephaly group.
Collapse
Affiliation(s)
- Piero Pavone
- University-Hospital “Policlinico-Vittorio Emanuele”
| | - Andrea Domenico Praticò
- Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry
- Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Renata Rizzo
- Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry
| | - Giovanni Corsello
- Department of Maternal and Child Health, University of Palermo, Palermo
| | - Martino Ruggieri
- Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry
| | - Enrico Parano
- National Research Council, Section of Catania, Catania, Italy
| | | |
Collapse
|
37
|
Abstract
INTRODUCTION Dishevelled, Egl-10 and Pleckstrin (DEP) domain-containing protein 5 (DEPDC5) is a protein subunit of the GTPase-activating proteins towards Rags 1 (GATOR1) complex. GATOR1 is a recently identified modulator of mechanistic target of rapamycin (mTOR) activity. mTOR is a key regulator of cell proliferation and metabolism; disruption of the mTOR pathway is implicated in focal epilepsy, both acquired and genetic. Tuberous sclerosis is the prototypic mTOR genetic syndrome with epilepsy, however GATOR1 gene mutations have recently been shown to cause lesional and non-lesional focal epilepsy. Areas covered: This review summarizes the mTOR pathway, including regulators and downstream effectors, emphasizing recent developments in the understanding of the complex role of the GATOR1 complex. We review the epilepsy types associated with mTOR overactivity, including tuberous sclerosis, polyhydramnios megalencephaly symptomatic epilepsy, cortical dysplasia, non-lesional focal epilepsy and post-traumatic epilepsy. Currently available mTOR inhibitors are discussed, primarily rapamycin analogs and ATP competitive mTOR inhibitors. Expert opinion: DEPDC5 is an attractive therapeutic target in focal epilepsy, as effects of DEPDC5 agonists would likely be anti-epileptogenic and more selective than currently available mTOR inhibitors. Therapeutic effects might be synergistic with certain existing dietary therapies, including the ketogenic diet.
Collapse
Affiliation(s)
- Kenneth A Myers
- a Epilepsy Research Centre, Department of Medicine , The University of Melbourne, Austin Health , Heidelberg , Victoria , Australia.,b Department of Paediatrics , Royal Children's Hospital, The University of Melbourne , Flemington , Victoria , Australia
| | - Ingrid E Scheffer
- a Epilepsy Research Centre, Department of Medicine , The University of Melbourne, Austin Health , Heidelberg , Victoria , Australia.,b Department of Paediatrics , Royal Children's Hospital, The University of Melbourne , Flemington , Victoria , Australia.,c The Florey Institute of Neuroscience and Mental Health , Heidelberg , Victoria , Australia
| |
Collapse
|
38
|
Suarato G, Lee SI, Li W, Rao S, Khan T, Meng Y, Shelly M. Micellar nanocomplexes for biomagnetic delivery of intracellular proteins to dictate axon formation during neuronal development. Biomaterials 2017; 112:176-191. [PMID: 27768972 PMCID: PMC5121005 DOI: 10.1016/j.biomaterials.2016.09.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 09/10/2016] [Accepted: 09/26/2016] [Indexed: 12/31/2022]
Abstract
During mammalian embryonic development, neurons polarize to create distinct cellular compartments of axon and dendrite that inherently differ in form and function, providing the foundation for directional signaling in the nervous system. Polarization results from spatio-temporal segregation of specific proteins' activities to discrete regions of the neuron to dictate axonal vs. dendritic fate. We aim to manipulate axon formation by directed subcellular localization of crucial intracellular protein function. Here we report critical steps toward the development of a nanotechnology for localized subcellular introduction and retention of an intracellular kinase, LKB1, crucial regulator of axon formation. This nanotechnology will spatially manipulate LKB1-linked biomagnetic nanocomplexes (LKB1-NCs) in developing rodent neurons in culture and in vivo. We created a supramolecular assembly for LKB1 rapid neuronal uptake and prolonged cytoplasmic stability. LKB1-NCs retained kinase activity and phosphorylated downstream targets. NCs were successfully delivered to cultured embryonic hippocampal neurons, and were stable in the cytoplasm for 2 days, sufficient time for axon formation. Importantly, LKB1-NCs promoted axon formation in these neurons, representing unique proof of concept for the sufficiency of intracellular protein function in dictating a central developmental event. Lastly, we established NC delivery into cortical progenitors in live rat embryonic brain in utero. Our nanotechnology provides a viable platform for spatial manipulation of intracellular protein-activity, to dictate central events during neuronal development.
Collapse
Affiliation(s)
- Giulia Suarato
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Seong-Il Lee
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Weiyi Li
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Sneha Rao
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Tanvir Khan
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Yizhi Meng
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Maya Shelly
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA.
| |
Collapse
|
39
|
Creuzet SE, Viallet JP, Ghawitian M, Torch S, Thélu J, Alrajeh M, Radu AG, Bouvard D, Costagliola F, Borgne ML, Buchet-Poyau K, Aznar N, Buschlen S, Hosoya H, Thibert C, Billaud M. LKB1 signaling in cephalic neural crest cells is essential for vertebrate head development. Dev Biol 2016; 418:283-96. [DOI: 10.1016/j.ydbio.2016.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 07/19/2016] [Accepted: 08/06/2016] [Indexed: 11/25/2022]
|
40
|
Abstract
Defining the multiple roles of the mechanistic (formerly 'mammalian') target of rapamycin (mTOR) signalling pathway in neurological diseases has been an exciting and rapidly evolving story of bench-to-bedside translational research that has spanned gene mutation discovery, functional experimental validation of mutations, pharmacological pathway manipulation, and clinical trials. Alterations in the dual contributions of mTOR - regulation of cell growth and proliferation, as well as autophagy and cell death - have been found in developmental brain malformations, epilepsy, autism and intellectual disability, hypoxic-ischaemic and traumatic brain injuries, brain tumours, and neurodegenerative disorders. mTOR integrates a variety of cues, such as growth factor levels, oxygen levels, and nutrient and energy availability, to regulate protein synthesis and cell growth. In line with the positioning of mTOR as a pivotal cell signalling node, altered mTOR activation has been associated with a group of phenotypically diverse neurological disorders. To understand how altered mTOR signalling leads to such divergent phenotypes, we need insight into the differential effects of enhanced or diminished mTOR activation, the developmental context of these changes, and the cell type affected by altered signalling. A particularly exciting feature of the tale of mTOR discovery is that pharmacological mTOR inhibitors have shown clinical benefits in some neurological disorders, such as tuberous sclerosis complex, and are being considered for clinical trials in epilepsy, autism, dementia, traumatic brain injury, and stroke.
Collapse
|
41
|
Bi W, Glass IA, Muzny DM, Gibbs RA, Eng CM, Yang Y, Sun A. Whole exome sequencing identifies the first STRADA point mutation in a patient with polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome (PMSE). Am J Med Genet A 2016; 170:2181-5. [PMID: 27170158 DOI: 10.1002/ajmg.a.37727] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 04/01/2016] [Indexed: 11/07/2022]
Abstract
Polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome (PMSE) is an ultra rare neurodevelopmental disorder characterized by severe, infantile-onset intractable epilepsy, neurocognitive delay, macrocephaly, and craniofacial dysmorphism. The molecular diagnosis of this condition has thus far only been made in 16 Old Order Mennonite patients carrying a homozygous 7 kb founder deletion of exons 9-13 of STRADA. We performed clinical whole exome sequencing (WES) on a 4-year-old Indian male with global developmental delay, history of failure to thrive, infantile spasms, repetitive behaviors, hypotonia, low muscle mass, marked joint laxity, and dysmorphic facial features including tall forehead, long face, arched eyebrows, small chin, wide mouth, and tented upper lip. A homozygous single nucleotide duplication, c.842dupA (p.D281fs), in exon 10 of STRADA was identified. Sanger sequencing confirmed the mutation in the individual and identified both parents as carriers. In light of the molecular discoveries, the patient's clinical phenotype was considered to be a good fit for PMSE. We identified for the first time a homozygous point mutation in STRADA causing PMSE. Additional bi-allelic mutations related to PMSE thus far have not been observed in Baylor ∼6,000 consecutive clinical WES cases, supporting the rarity of this disorder. Our findings may have treatment implications for the patient since previous studies have shown rapamycin as a potential therapeutic agent for the seizures and cognitive problems in PMSE patients. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Ian A Glass
- Department of Pediatrics, University of Washington, Seattle, Washington
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - Christine M Eng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Angela Sun
- Department of Pediatrics, University of Washington, Seattle, Washington
| |
Collapse
|
42
|
Tee AR, Sampson JR, Pal DK, Bateman JM. The role of mTOR signalling in neurogenesis, insights from tuberous sclerosis complex. Semin Cell Dev Biol 2016; 52:12-20. [PMID: 26849906 DOI: 10.1016/j.semcdb.2016.01.040] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/05/2016] [Accepted: 01/25/2016] [Indexed: 11/30/2022]
Abstract
Understanding the development and function of the nervous system is one of the foremost aims of current biomedical research. The nervous system is generated during a relatively short period of intense neurogenesis that is orchestrated by a number of key molecular signalling pathways. Even subtle defects in the activity of these molecules can have serious repercussions resulting in neurological, neurodevelopmental and neurocognitive problems including epilepsy, intellectual disability and autism. Tuberous sclerosis complex (TSC) is a monogenic disease characterised by these problems and by the formation of benign tumours in multiple organs, including the brain. TSC is caused by mutations in the TSC1 or TSC2 gene leading to activation of the mechanistic target of rapamycin (mTOR) signalling pathway. A desire to understand the neurological manifestations of TSC has stimulated research into the role of the mTOR pathway in neurogenesis. In this review we describe TSC neurobiology and how the use of animal model systems has provided insights into the roles of mTOR signalling in neuronal differentiation and migration. Recent progress in this field has identified novel mTOR pathway components regulating neuronal differentiation. The roles of mTOR signalling and aberrant neurogenesis in epilepsy are also discussed. Continuing efforts to understand mTOR neurobiology will help to identify new therapeutic targets for TSC and other neurological diseases.
Collapse
Affiliation(s)
- Andrew R Tee
- Institute of Cancer & Genetics, Cardiff University School of Medicine, Institute of Medical Genetics Building, Heath Park, Cardiff CF14 4XN UK
| | - Julian R Sampson
- Institute of Cancer & Genetics, Cardiff University School of Medicine, Institute of Medical Genetics Building, Heath Park, Cardiff CF14 4XN UK
| | - Deb K Pal
- Department of Basic & Clinical Neurosciences, Institute of Psychiatry, Psychology & Neuroscience, King's College, London SE5 8RX UK
| | - Joseph M Bateman
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London SE1 1UL UK.
| |
Collapse
|
43
|
Gai Z, Chu W, Deng W, Li W, Li H, He A, Nellist M, Wu G. Structure of the TBC1D7-TSC1 complex reveals that TBC1D7 stabilizes dimerization of the TSC1 C-terminal coiled coil region. J Mol Cell Biol 2016; 8:411-425. [PMID: 26798146 DOI: 10.1093/jmcb/mjw001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/03/2015] [Accepted: 12/10/2015] [Indexed: 01/01/2023] Open
Abstract
TSC1 and TSC2 mutations account for the majority of tuberous sclerosis complex cases. The TSC1 and TSC2 proteins assemble into a complex that is stabilized by TBC1D7 through its direct interaction with the TSC1 coiled coil (CC) region. Loss of TBC1D7 is associated with intellectual disability and megalencephaly. Here, we determine the crystal structure of the complex between TBC1D7 and the C-terminal part (residues 939-992) of TSC1-CC. The structure reveals that two TSC1-CCs form a parallel homodimer, which results in the formation of two symmetric surfaces for interaction with TBC1D7. TBC1D7 employs its α4 and α5 helices to interact with the α1 helix of one TSC1 (939-992) molecule mainly through hydrophobic interactions, and simultaneously associates with the other TSC1 (939-992) molecule using the C-terminal tip of its α4 helix. Biochemical and cell biological data demonstrate that TBC1D7 indeed substantially stabilizes the homodimerization of TSC1-CC, and mutations to the critical interface residues greatly compromise this effect. Together, our data reveal the molecular mechanism underlying TBC1D7-mediated stabilization of TSC1 dimerization, and its contribution to the structural integrity of the holo-TSC complex.
Collapse
Affiliation(s)
- Zhongchao Gai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Wendan Chu
- The China National Center for Protein Sciences (Beijing) Tsinghua University Branch, Beijing, China
| | - Wei Deng
- National Center for Protein Science Shanghai, Shanghai, China
| | - Wenqi Li
- The China National Center for Protein Sciences (Beijing) Tsinghua University Branch, Beijing, China
| | - Hua Li
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ailiang He
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Mark Nellist
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Geng Wu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
44
|
Ohtaka-Maruyama C, Okado H. Molecular Pathways Underlying Projection Neuron Production and Migration during Cerebral Cortical Development. Front Neurosci 2015; 9:447. [PMID: 26733777 PMCID: PMC4682034 DOI: 10.3389/fnins.2015.00447] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 11/09/2015] [Indexed: 12/25/2022] Open
Abstract
Glutamatergic neurons of the mammalian cerebral cortex originate from radial glia (RG) progenitors in the ventricular zone (VZ). During corticogenesis, neuroblasts migrate toward the pial surface using two different migration modes. One is multipolar (MP) migration with random directional movement, and the other is locomotion, which is a unidirectional movement guided by the RG fiber. After reaching their final destination, the neurons finalize their migration by terminal translocation, which is followed by maturation via dendrite extension to initiate synaptogenesis and thereby complete neural circuit formation. This switching of migration modes during cortical development is unique in mammals, which suggests that the RG-guided locomotion mode may contribute to the evolution of the mammalian neocortical 6-layer structure. Many factors have been reported to be involved in the regulation of this radial neuronal migration process. In general, the radial migration can be largely divided into four steps; (1) maintenance and departure from the VZ of neural progenitor cells, (2) MP migration and transition to bipolar cells, (3) RG-guided locomotion, and (4) terminal translocation and dendrite maturation. Among these, many different gene mutations or knockdown effects have resulted in failure of the MP to bipolar transition (step 2), suggesting that it is a critical step, particularly in radial migration. Moreover, this transition occurs at the subplate layer. In this review, we summarize recent advances in our understanding of the molecular mechanisms underlying each of these steps. Finally, we discuss the evolutionary aspects of neuronal migration in corticogenesis.
Collapse
Affiliation(s)
- Chiaki Ohtaka-Maruyama
- Neural Network Project, Department of Brain Development and Neural Regeneration, Tokyo Metropolitan Institute of Medical Science Tokyo, Japan
| | - Haruo Okado
- Neural Development Project, Department of Brain Development and Neural Regeneration, Tokyo Metropolitan Institute of Medical Science Tokyo, Japan
| |
Collapse
|
45
|
Abstract
TOR (target of rapamycin) and its mammalian ortholog mTOR have been discovered in an effort to understand the mechanisms of action of the immunosuppressant drug rapamycin extracted from a bacterium of the Easter Island (Rapa Nui) soil. mTOR is a serine/threonine kinase found in two functionally distinct complexes, mTORC1 and mTORC2, which are differentially regulated by a great number of nutrients such as glucose and amino acids, energy (oxygen and ATP/AMP content), growth factors, hormones, and neurotransmitters. mTOR controls many basic cellular functions such as protein synthesis, energy metabolism, cell size, lipid metabolism, autophagy, mitochondria, and lysosome biogenesis. In addition, mTOR-controlled signaling pathways regulate many integrated physiological functions of the nervous system including neuronal development, synaptic plasticity, memory storage, and cognition. Thus it is not surprising that deregulation of mTOR signaling is associated with many neurological and psychiatric disorders. Preclinical and preliminary clinical studies indicate that inhibition of mTORC1 can be beneficial for some pathological conditions such as epilepsy, cognitive impairment, and brain tumors, whereas stimulation of mTORC1 (direct or indirect) can be beneficial for other pathologies such as depression or axonal growth and regeneration.
Collapse
Affiliation(s)
- Joël Bockaert
- Centre National de la Recherche Scientifique, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France; Institut National de la Santé et de la Recherche Médicale U1191, Montpellier, France; and Université de Montpellier, UMR-5203, Montpellier, France
| | - Philippe Marin
- Centre National de la Recherche Scientifique, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France; Institut National de la Santé et de la Recherche Médicale U1191, Montpellier, France; and Université de Montpellier, UMR-5203, Montpellier, France
| |
Collapse
|
46
|
Kim GE, Ross JL, Xie C, Su KN, Zaha VG, Wu X, Palmeri M, Ashraf M, Akar JG, Russell KS, Akar FG, Young LH. LKB1 deletion causes early changes in atrial channel expression and electrophysiology prior to atrial fibrillation. Cardiovasc Res 2015; 108:197-208. [PMID: 26378152 PMCID: PMC4571838 DOI: 10.1093/cvr/cvv212] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 07/09/2015] [Accepted: 07/14/2015] [Indexed: 12/19/2022] Open
Abstract
AIMS Liver kinase B1 (LKB1) is a protein kinase that activates the metabolic regulator AMP-activated protein kinase (AMPK) and other related kinases. Deletion of LKB1 in mice leads to cardiomyopathy and atrial fibrillation (AF). However, the specific role of the LKB1 pathway in early atrial biology remains unknown. Thus, we investigated whether LKB1 deletion altered atrial channel expression and electrophysiological function in a cardiomyocyte-specific knockout mouse model. METHODS AND RESULTS We performed a systematic comparison of αMHC-Cre LKB1(fl/fl) and littermate LKB1(fl/fl) male mice. This included analysis of gene expression, histology, and echocardiography, as well as cellular and tissue-level electrophysiology using patch-clamp recordings in vitro, optical mapping ex vivo, and ECG recordings in vivo. At postnatal day 1, atrial depolarization was prolonged, and Nav1.5 and Cx40 expression were markedly down-regulated in MHC-Cre LKB1(fl/fl) mice. Inward sodium current density was significantly decreased in MHC-Cre LKB1(fl/fl) neonatal atrial myocytes. Subsequently, additional alterations in atrial channel expression, atrial fibrosis, and spontaneous onset of AF developed by 2 weeks of age. In adult mice, abnormalities of interatrial conduction and bi-atrial electrical coupling were observed, likely promoting the perpetuation of AF. Mice with AMPK-inactivated hearts demonstrated modest overlap in channel expression with MHC-Cre LKB1(fl/fl) hearts, but retained normal structure, electrophysiological function and contractility. CONCLUSIONS Deletion of LKB1 causes early defects in atrial channel expression, action potential generation and conduction, which precede widespread atrial remodelling, fibrosis and AF. LKB1 is critical for normal atrial growth and electrophysiological function.
Collapse
Affiliation(s)
- Grace E Kim
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA
| | - Jenna L Ross
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Chaoqin Xie
- Cardiovascular Research Center, Mt. Sinai School of Medicine, New York, NY 10029, USA
| | - Kevin N Su
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA
| | - Vlad G Zaha
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Xiaohong Wu
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Monica Palmeri
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Mohammed Ashraf
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Joseph G Akar
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Kerry S Russell
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Fadi G Akar
- Cardiovascular Research Center, Mt. Sinai School of Medicine, New York, NY 10029, USA
| | - Lawrence H Young
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT 06520, USA Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| |
Collapse
|
47
|
Sadowski K, Kotulska-jóźwiak K, Jóźwiak S. Role of mTOR inhibitors in epilepsy treatment. Pharmacol Rep 2015; 67:636-46. [DOI: 10.1016/j.pharep.2014.12.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 12/24/2014] [Accepted: 12/30/2014] [Indexed: 01/16/2023]
|
48
|
Lin YX, Lin K, Kang DZ, Liu XX, Wang XF, Zheng SF, Yu LH, Lin ZY. Similar PDK1–AKT–mTOR pathway activation in balloon cells and dysmorphic neurons of type II focal cortical dysplasia with refractory epilepsy. Epilepsy Res 2015; 112:137-49. [DOI: 10.1016/j.eplepsyres.2015.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 01/25/2015] [Accepted: 02/06/2015] [Indexed: 11/30/2022]
|
49
|
Abstract
Over the past decade enhanced activation of the mammalian target of rapamycin (mTOR)-signaling cascade has been identified in focal malformations of cortical development (MCD) subtypes, which have been collectively referred to as "mTORopathies." Mutations in mTOR regulatory genes (e.g., TSC1, TSC2, AKT3, DEPDC5) have been associated with several focal MCD highly associated with epilepsy such as tuberous sclerosis complex (TSC), hemimegalencephaly (HME; brain malformation associated with dramatic enlargement of one brain hemisphere), and cortical dysplasia. mTOR plays important roles in the regulation of cell division, growth, and survival, and, thus, aberrant activation of the cascade during cortical development can cause dramatic alterations in cell size, cortical lamination, and axon and dendrite outgrowth often observed in focal MCD. Although it is widely believed that structural alterations induced by hyperactivated mTOR signaling are critical for epileptogenesis, newer evidence suggests that mTOR activation on its own may enhance neuronal excitability. Clinical trials with mTOR inhibitors have shown efficacy in the treatment of seizures associated with focal MCD.
Collapse
Affiliation(s)
- Peter B Crino
- Shriners Hospital Pediatric Research Center and Department of Neurology, Temple University, Philadelphia, Pennsylvania 19140
| |
Collapse
|
50
|
Nguyen LH, Brewster AL, Clark ME, Regnier-Golanov A, Sunnen CN, Patil VV, D'Arcangelo G, Anderson AE. mTOR inhibition suppresses established epilepsy in a mouse model of cortical dysplasia. Epilepsia 2015; 56:636-46. [PMID: 25752454 DOI: 10.1111/epi.12946] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/21/2015] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Hyperactivation of the mechanistic target of rapamycin (mTOR; also known as mammalian target of rapamycin) pathway has been demonstrated in human cortical dysplasia (CD) as well as in animal models of epilepsy. Although inhibition of mTOR signaling early in epileptogenesis suppressed epileptiform activity in the neuron subset-specific Pten knockout (NS-Pten KO) mouse model of CD, the effects of mTOR inhibition after epilepsy is fully established were not previously examined in this model. Here, we investigated whether mTOR inhibition suppresses epileptiform activity and other neuropathological correlates in adult NS-Pten KO mice with severe and well-established epilepsy. METHODS The progression of epileptiform activity, mTOR pathway dysregulation, and associated neuropathology with age in NS-Pten KO mice were evaluated using video-electroencephalography (EEG) recordings, Western blotting, and immunohistochemistry. A cohort of NS-Pten KO mice was treated with the mTOR inhibitor rapamycin (10 mg/kg i.p., 5 days/week) starting at postnatal week 9 and video-EEG monitored for epileptiform activity. Western blotting and immunohistochemistry were performed to evaluate the effects of rapamycin on the associated pathology. RESULTS Epileptiform activity worsened with age in NS-Pten KO mice, with parallel increases in the extent of hippocampal mTOR complex 1 and 2 (mTORC1 and mTORC2, respectively) dysregulation and progressive astrogliosis and microgliosis. Rapamycin treatment suppressed epileptiform activity, improved baseline EEG activity, and increased survival in severely epileptic NS-Pten KO mice. At the molecular level, rapamycin treatment was associated with a reduction in both mTORC1 and mTORC2 signaling and decreased astrogliosis and microgliosis. SIGNIFICANCE These findings reveal a wide temporal window for successful therapeutic intervention with rapamycin in the NS-Pten KO mouse model, and they support mTOR inhibition as a candidate therapy for established, late-stage epilepsy associated with CD and genetic dysregulation of the mTOR pathway.
Collapse
Affiliation(s)
- Lena H Nguyen
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, U.S.A; The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, U.S.A; The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, Texas, U.S.A
| | | | | | | | | | | | | | | |
Collapse
|