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Yao Y, Qiu L, Wei X, Chen J, Choy KW, Zheng G, Yang T, Li S, Yang F. Functional study of a rare L1CAM gene c.1759G>C variant prove its pathogenicity. Cell Biochem Funct 2024; 42:e4034. [PMID: 38715189 DOI: 10.1002/cbf.4034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 04/29/2024] [Accepted: 04/29/2024] [Indexed: 05/14/2024]
Abstract
L1 syndrome, a neurological disorder with an X-linked inheritance pattern, mainly results from mutations occurring in the L1 cell adhesion molecule (L1CAM) gene. The L1CAM molecule, belonging to the immunoglobulin (Ig) superfamily of neurocyte adhesion molecules, plays a pivotal role in facilitating intercellular signal transmission across membranes and is indispensable for proper neuronal development and function. This study identified a rare missense variant (c.1759G>C; p.G587R) in the L1CAM gene within a male fetus presenting with hydrocephalus. Due to a lack of functional analysis, the significance of the L1CAM mutation c.1759G>C (p.G587R) remains unknown. We aimed to perform further verification for its pathogenicity. Blood samples were obtained from the proband and his parents for trio clinical exome sequencing and mutation analysis. Expression level analysis was conducted using western blot techniques. Immunofluorescence was employed to investigate L1CAM subcellular localization, while cell aggregation and cell scratch assays were utilized to assess protein function. The study showed that the mutation (c.1759G>C; p.G587R) affected posttranslational glycosylation modification and induced alterations in the subcellular localization of L1-G587R in the cells. It resulted in the diminished expression of L1CAM on the cell surface and accumulation in the endoplasmic reticulum. The p.G587R altered the function of L1CAM protein and reduced homophilic adhesion capacity of proteins, leading to impaired adhesion and migration of proteins between cells. Our findings provide first biological evidence for the association between the missense mutation (c.1759G>c; p.G587R) in the L1CAM gene and L1 syndrome, confirming the pathogenicity of this missense mutation.
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Affiliation(s)
- Yuqing Yao
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Liyan Qiu
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Xingyu Wei
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jianping Chen
- Medical Equipment Department, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Kwong Wai Choy
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, China
- Laboratory of Genetics and Genomics, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Guiyun Zheng
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Tuyin Yang
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Sisi Li
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Fang Yang
- Department of Fetal Medicine and Prenatal Diagnosis, Zhujiang Hospital, Southern Medical University, Guangzhou, China
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Chung KP, Frieboese D, Waltz F, Engel BD, Bock R. Identification and characterization of the COPII vesicle-forming GTPase Sar1 in Chlamydomonas. PLANT DIRECT 2024; 8:e614. [PMID: 38887666 PMCID: PMC11180857 DOI: 10.1002/pld3.614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 05/29/2024] [Indexed: 06/20/2024]
Abstract
Eukaryotic cells are highly compartmentalized, requiring elaborate transport mechanisms to facilitate the movement of proteins between membrane-bound compartments. Most proteins synthesized in the endoplasmic reticulum (ER) are transported to the Golgi apparatus through COPII-mediated vesicular trafficking. Sar1, a small GTPase that facilitates the formation of COPII vesicles, plays a critical role in the early steps of this protein secretory pathway. Sar1 was characterized in yeast, animals and plants, but no Sar1 homolog has been identified and functionally analyzed in algae. Here we identified a putative Sar1 homolog (CrSar1) in the model green alga Chlamydomonas reinhardtii through amino acid sequence similarity. We employed site-directed mutagenesis to generate a dominant-negative mutant of CrSar1 (CrSar1DN). Using protein secretion assays, we demonstrate the inhibitory effect of CrSar1DN on protein secretion. However, different from previously studied organisms, ectopic expression of CrSar1DN did not result in collapse of the ER-Golgi interface in Chlamydomonas. Nonetheless, our data suggest a largely conserved role of CrSar1 in the ER-to-Golgi protein secretory pathway in green algae.
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Affiliation(s)
- Kin Pan Chung
- Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdamGermany
| | - Daniel Frieboese
- Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdamGermany
| | | | | | - Ralph Bock
- Max‐Planck‐Institut für Molekulare PflanzenphysiologiePotsdamGermany
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3
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Pompili SVB, Fanzini S, Schachner M, Chen S. In Vitro and In Vivo Studies of Melanoma Cell Migration by Antagonistic Mimetics of Adhesion Molecule L1CAM. Int J Mol Sci 2024; 25:4811. [PMID: 38732030 PMCID: PMC11084881 DOI: 10.3390/ijms25094811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/08/2024] [Accepted: 04/25/2024] [Indexed: 05/13/2024] Open
Abstract
Melanoma, the deadliest type of skin cancer, has a high propensity to metastasize to other organs, including the brain, lymph nodes, lungs, and bones. While progress has been made in managing melanoma with targeted and immune therapies, many patients do not benefit from these current treatment modalities. Tumor cell migration is the initial step for invasion and metastasis. A better understanding of the molecular mechanisms underlying metastasis is crucial for developing therapeutic strategies for metastatic diseases, including melanoma. The cell adhesion molecule L1CAM (CD171, in short L1) is upregulated in many human cancers, enhancing tumor cell migration. Earlier studies showed that the small-molecule antagonistic mimetics of L1 suppress glioblastoma cell migration in vitro. This study aims to evaluate if L1 mimetic antagonists can inhibit melanoma cell migration in vitro and in vivo. We showed that two antagonistic mimetics of L1, anagrelide and 2-hydroxy-5-fluoropyrimidine (2H5F), reduced melanoma cell migration in vitro. In in vivo allograft studies, only 2H5F-treated female mice showed a decrease in tumor volume.
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Affiliation(s)
- Stefano Vito Boccadamo Pompili
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University, 00185 Rome, Italy
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA;
| | - Sophia Fanzini
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA;
| | - Melitta Schachner
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA;
| | - Suzie Chen
- Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA;
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08901, USA
- VA New Jersey Health System, East Orange, NJ 07018, USA
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Granato V, Congiu L, Jakovcevski I, Kleene R, Schwindenhammer B, Fernandes L, Freitag S, Schachner M, Loers G. Mice Mutated in the First Fibronectin Domain of Adhesion Molecule L1 Show Brain Malformations and Behavioral Abnormalities. Biomolecules 2024; 14:468. [PMID: 38672483 PMCID: PMC11048097 DOI: 10.3390/biom14040468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/18/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
The X-chromosome-linked cell adhesion molecule L1 (L1CAM), a glycoprotein mainly expressed by neurons in the central and peripheral nervous systems, has been implicated in many neural processes, including neuronal migration and survival, neuritogenesis, synapse formation, synaptic plasticity and regeneration. L1 consists of extracellular, transmembrane and cytoplasmic domains. Proteolytic cleavage of L1's extracellular and transmembrane domains by different proteases generates several L1 fragments with different functions. We found that myelin basic protein (MBP) cleaves L1's extracellular domain, leading to enhanced neuritogenesis and neuronal survival in vitro. To investigate in vivo the importance of the MBP-generated 70 kDa fragment (L1-70), we generated mice with an arginine to alanine substitution at position 687 (L1/687), thereby disrupting L1's MBP cleavage site and obliterating L1-70. Young adult L1/687 males showed normal anxiety and circadian rhythm activities but enhanced locomotion, while females showed altered social interactions. Older L1/687 males were impaired in motor coordination. Furthermore, L1/687 male and female mice had a larger hippocampus, with more neurons in the dentate gyrus and more proliferating cells in the subgranular layer, while the thickness of the corpus callosum and the size of lateral ventricles were normal. In summary, subtle mutant morphological changes result in subtle behavioral changes.
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Affiliation(s)
- Viviana Granato
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Ludovica Congiu
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Igor Jakovcevski
- Institut für Anatomie und Klinische Morphologie, Universität Witten/Herdecke, 58455 Witten, Germany; (I.J.); (B.S.)
- Department of Neuroanatomy and Molecular Brain Research, Institute of Anatomy, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Ralf Kleene
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Benjamin Schwindenhammer
- Institut für Anatomie und Klinische Morphologie, Universität Witten/Herdecke, 58455 Witten, Germany; (I.J.); (B.S.)
- Department of Neuroanatomy and Molecular Brain Research, Institute of Anatomy, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Luciana Fernandes
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Sandra Freitag
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
| | - Melitta Schachner
- Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08554, USA
| | - Gabriele Loers
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (V.G.); (L.C.); (R.K.); (S.F.)
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Mir A, Song Y, Lee H, Khanahmad H, Khorram E, Nasiri J, Tabatabaiefar MA. Whole exome sequencing revealed variants in four genes underlying X-linked intellectual disability in four Iranian families: novel deleterious variants and clinical features with the review of literature. BMC Med Genomics 2023; 16:239. [PMID: 37821930 PMCID: PMC10566173 DOI: 10.1186/s12920-023-01680-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 10/01/2023] [Indexed: 10/13/2023] Open
Abstract
AIM AND OBJECTIVE Intellectual disability (ID) is a heterogeneous condition affecting brain development, function, and/or structure. The X-linked mode of inheritance of ID (X-linked intellectual disability; XLID) has a prevalence of 1 out of 600 to 1000 males. In the last decades, exome sequencing technology has revolutionized the process of disease-causing gene discovery in XLIDs. Nevertheless, so many of them still remain with unknown etiology. This study investigated four families with severe XLID to identify deleterious variants for possible diagnostics and prevention aims. METHODS Nine male patients belonging to four pedigrees were included in this study. The patients were studied genetically for Fragile X syndrome, followed by whole exome sequencing and analysis of intellectual disability-related genes variants. Sanger sequencing, co-segregation analysis, structural modeling, and in silico analysis were done to verify the causative variants. In addition, we collected data from previous studies to compare and situate our work with existing knowledge. RESULTS In three of four families, novel deleterious variants have been identified in three different genes, including ZDHHC9 (p. Leu189Pro), ATP2B3 (p. Asp847Glu), and GLRA2 (p. Arg350Cys) and also with new clinical features and in another one family, a reported pathogenic variant in the L1CAM (p. Glu309Lys) gene has been identified related to new clinical findings. CONCLUSION The current study's findings expand the existing knowledge of variants of the genes implicated in XLID and broaden the spectrum of phenotypes associated with the related conditions. The data have implications for genetic diagnosis and counseling.
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Affiliation(s)
- Atefeh Mir
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, 81746 73461, Iran
| | - Yongjun Song
- Division of Medical Genetics, 3Billion Inc, Seoul, South Korea
| | - Hane Lee
- Division of Medical Genetics, 3Billion Inc, Seoul, South Korea
| | - Hossein Khanahmad
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, 81746 73461, Iran
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Erfan Khorram
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, 81746 73461, Iran
| | - Jafar Nasiri
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, 81746 73461, Iran.
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
- Deputy of Research and Technology, GenTArget Corp (GTAC), Isfahan University of Medical Sciences, Isfahan, Iran.
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Banerjee A, Biswas D, Barpanda A, Halder A, Sibal S, Kattimani R, Shah A, Mahadevan A, Goel A, Srivastava S. The First Pituitary Proteome Landscape From Matched Anterior and Posterior Lobes for a Better Understanding of the Pituitary Gland. Mol Cell Proteomics 2022; 22:100478. [PMID: 36470533 PMCID: PMC9877467 DOI: 10.1016/j.mcpro.2022.100478] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
To date, very few mass spectrometry (MS)-based proteomics studies are available on the anterior and posterior lobes of the pituitary. In the past, MS-based investigations have focused exclusively on the whole pituitary gland or anterior pituitary lobe. In this study, for the first time, we performed a deep MS-based analysis of five anterior and five posterior matched lobes to build the first lobe-specific pituitary proteome map, which documented 4090 proteins with isoforms, mostly mapped into chromosomes 1, 2, and 11. About 1446 differentially expressed significant proteins were identified, which were studied for lobe specificity, biological pathway enrichment, protein-protein interaction, regions specific to comparison of human brain and other neuroendocrine glands from Human Protein Atlas to identify pituitary-enriched proteins. Hormones specific to each lobe were also identified and validated with parallel reaction monitoring-based target verification. The study identified and validated hormones, growth hormone and thyroid-stimulating hormone subunit beta, exclusively to the anterior lobe whereas oxytocin-neurophysin 1 and arginine vasopressin to the posterior lobe. The study also identified proteins POU1F1 (pituitary-specific positive transcription factor 1), POMC (pro-opiomelanocortin), PCOLCE2 (procollagen C-endopeptidase enhancer 2), and NPTX2 (neuronal pentraxin-2) as pituitary-enriched proteins and was validated for their lobe specificity using parallel reaction monitoring. In addition, three uPE1 proteins, namely THEM6 (mesenchymal stem cell protein DSCD75), FSD1L (coiled-coil domain-containing protein 10), and METTL26 (methyltransferase-like 26), were identified using the NeXtProt database, and depicted tumor markers S100 proteins having high expression in the posterior lobe. In summary, the study documents the first matched anterior and posterior pituitary proteome map acting as a reference control for a better understanding of functional and nonfunctional pituitary adenomas and extrapolating the aim of the Human Proteome Project towards the investigation of the proteome of life.
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Affiliation(s)
- Arghya Banerjee
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Deepatarup Biswas
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Abhilash Barpanda
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Ankit Halder
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Shamira Sibal
- Lokmanya Tilak Municipal Medical College, Mumbai, India
| | | | - Abhidha Shah
- Department of Neurosurgery at King Edward Memorial Hospital and Seth G. S. Medical College, Mumbai, India
| | - Anita Mahadevan
- Human Brain Bank, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore, India
| | - Atul Goel
- Department of Neurosurgery at King Edward Memorial Hospital and Seth G. S. Medical College, Mumbai, India
| | - Sanjeeva Srivastava
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
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Stoyanova II, Lutz D. Functional Diversity of Neuronal Cell Adhesion and Recognition Molecule L1CAM through Proteolytic Cleavage. Cells 2022; 11:cells11193085. [PMID: 36231047 PMCID: PMC9562852 DOI: 10.3390/cells11193085] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
The neuronal cell adhesion and recognition molecule L1 does not only 'keep cells together' by way of homophilic and heterophilic interactions, but can also promote cell motility when cleaved into fragments by several proteases. It has largely been thought that such fragments are signs of degradation. Now, it is clear that proteolysis contributes to the pronounced functional diversity of L1, which we have reviewed in this work. L1 fragments generated at the plasma membrane are released into the extracellular space, whereas other membrane-bound fragments are internalised and enter the nucleus, thus conveying extracellular signals to the cell interior. Post-translational modifications on L1 determine the sequence of cleavage by proteases and the subcellular localisation of the generated fragments. Inside the neuronal cells, L1 fragments interact with various binding partners to facilitate morphogenic events, as well as regenerative processes. The stimulation of L1 proteolysis via injection of L1 peptides or proteases active on L1 or L1 mimetics is a promising tool for therapy of injured nervous systems. The collective findings gathered over the years not only shed light on the great functional diversity of L1 and its fragments, but also provide novel mechanistic insights into the adhesion molecule proteolysis that is active in the developing and diseased nervous system.
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Affiliation(s)
- Irina I. Stoyanova
- Department of Anatomy and Cell Biology, Faculty of Medicine, Medical University, 9002 Varna, Bulgaria
- Department of Brain Ischemia Mechanisms, Research Institute, Medical University, 9002 Varna, Bulgaria
- Correspondence: (I.I.S.); (D.L.)
| | - David Lutz
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum,
44801 Bochum, Germany
- Correspondence: (I.I.S.); (D.L.)
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Li D, Gao H, Zheng W, Jin C, Huang Y, Pan S. Case report: Fetal cervical immature teratoma and copy number variations. Front Oncol 2022; 12:843268. [PMID: 36046039 PMCID: PMC9423720 DOI: 10.3389/fonc.2022.843268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 07/19/2022] [Indexed: 11/30/2022] Open
Abstract
Fetal cervical teratoma is a rare congenital neck tumor. Here, we report a case of a fetus with an anterior solid neck tumor that was confirmed to have an immature teratoma by histology. A duplication was found at chromosome 14q24.1-q24.3 of the fetus in chromosome microarray (CMA) and whole exome sequencing (WES), which was a copy number variation (CNV) and a probably new-onset. Ultrasound coupled with magnetic resonance imaging (MRI) can be considered to be a relatively reliable diagnostic tool, whereas ex-utero intrapartum therapy or resection of the tumor mass on placental support may improve the chances of the newborn’s survival. Strangely, the same duplication occurred on her next fetus that was found with complex congenital heart malformations. CNV at chromosome 14q24.1-q24.3 needs to be paid more attention.
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Affiliation(s)
- Dianjie Li
- Department of Gynaecology and Obstetrics, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Hong Gao
- Department of Urology, Shenzhen Hospital, University of Chinese Academy of Sciences, Shenzhen, China
| | - Wanting Zheng
- Department of Gynaecology and Obstetrics, Shantou Central Hospital, Shantou, China
| | - Chunzhu Jin
- Department of Gynaecology and Obstetrics, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Yuxin Huang
- Department of Gynaecology and Obstetrics, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Yuxin Huang, ; Shilei Pan,
| | - Shilei Pan
- Department of Gynaecology and Obstetrics, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Yuxin Huang, ; Shilei Pan,
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9
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Congiu L, Granato V, Loers G, Kleene R, Schachner M. Mitochondrial and Neuronal Dysfunctions in L1 Mutant Mice. Int J Mol Sci 2022; 23:ijms23084337. [PMID: 35457156 PMCID: PMC9026747 DOI: 10.3390/ijms23084337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 12/04/2022] Open
Abstract
Adhesion molecules regulate cell proliferation, migration, survival, neuritogenesis, synapse formation and synaptic plasticity during the nervous system’s development and in the adult. Among such molecules, the neural cell adhesion molecule L1 contributes to these functions during development, and in synapse formation, synaptic plasticity and regeneration after trauma. Proteolytic cleavage of L1 by different proteases is essential for these functions. A proteolytic fragment of 70 kDa (abbreviated L1-70) comprising part of the extracellular domain and the transmembrane and intracellular domains was shown to interact with mitochondrial proteins and is suggested to be involved in mitochondrial functions. To further determine the role of L1-70 in mitochondria, we generated two lines of gene-edited mice expressing full-length L1, but no or only low levels of L1-70. We showed that in the absence of L1-70, mitochondria in cultured cerebellar neurons move more retrogradely and exhibit reduced mitochondrial membrane potential, impaired Complex I activity and lower ATP levels compared to wild-type littermates. Neither neuronal migration, neuronal survival nor neuritogenesis in these mutants were stimulated with a function-triggering L1 antibody or with small agonistic L1 mimetics. These results suggest that L1-70 is important for mitochondrial homeostasis and that its absence contributes to the L1 syndrome phenotypes.
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Affiliation(s)
- Ludovica Congiu
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (L.C.); (V.G.); (G.L.); (R.K.)
| | - Viviana Granato
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (L.C.); (V.G.); (G.L.); (R.K.)
| | - Gabriele Loers
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (L.C.); (V.G.); (G.L.); (R.K.)
| | - Ralf Kleene
- Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany; (L.C.); (V.G.); (G.L.); (R.K.)
| | - Melitta Schachner
- Keck Center for Collaborative Neuroscience, Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08554, USA
- Correspondence: ; Tel.: +1-848-445-1780
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10
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Wang P, Liao H, Wang Q, Xie H, Wang H, Yang M, Liu S. L1 Syndrome Prenatal Diagnosis Supplemented by Functional Analysis of One L1CAM Gene Missense Variant. Reprod Sci 2021; 29:768-780. [PMID: 34914080 PMCID: PMC8863719 DOI: 10.1007/s43032-021-00828-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/06/2021] [Indexed: 11/30/2022]
Abstract
L1 syndrome, a complex X-linked neurological disorder, is caused by mutations in the L1 cell adhesion molecule (L1CAM) gene. L1CAM molecule is a member of immunoglobulin (Ig) superfamily of neural cell adhesion molecules (CAMs), which plays a pivotal role in the developing nervous system. In this study, a L1CAM gene exonic missense variant (c.1108G > A, p.G370R) was identified in two induced fetuses (abnormal fetuses), who presented corpus callosum agenesis accompanied with hydrocephalus. Clinical data, published literature, online database, and bioinformatic analysis suggest that the single-nucleotide variant of L1CAM gene is a likely pathogenic mutation. In vitro assays were performed to evaluate the effects of this variant. Based on NSC-34/COS-7 cells transfected with wild-type (L1-WT) and mutated (L1-G370R) plasmids, the L1CAM gene exonic missense variant (c.1108G > A, p.G370R) reduced cell surface expression, induced partial endoplasmic reticulum retention, affected posttranslational modification, and reduced protein’s homophilic adhesive ability, but did not induce endoplasmic reticulum stress, which might probably associate with L1 syndrome. Finally, 35 isolated fetuses were screened for L1CAM gene variants by Sanger sequencing. These cases all prenatally suspected of corpus callosum agenesis accompanied with hydrocephalus, which may relate to L1 syndrome. Consequently, one L1CAM gene single missense variant (c.550C > T, p.R184W) was detected in one fetus. Our results provided evidence that the L1CAM gene missense variant (c.1108G > A, p.G370R) may relate to L1 syndrome. The findings of this study suggest a potential possibility of L1CAM gene screening for prenatal diagnoses for fetuses presented corpus callosum agenesis accompanied with hydrocephalus.
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Affiliation(s)
- Ping Wang
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, No. 20, Section 3, Renminnan Road, Chengdu, 610041, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Hong Liao
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, No. 20, Section 3, Renminnan Road, Chengdu, 610041, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Quyou Wang
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, No. 20, Section 3, Renminnan Road, Chengdu, 610041, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Hanbing Xie
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, No. 20, Section 3, Renminnan Road, Chengdu, 610041, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - He Wang
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, No. 20, Section 3, Renminnan Road, Chengdu, 610041, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Mei Yang
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, No. 20, Section 3, Renminnan Road, Chengdu, 610041, Sichuan, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Shanling Liu
- Department of Obstetrics & Gynecology, West China Second University Hospital, Sichuan University, No. 20, Section 3, Renminnan Road, Chengdu, 610041, Sichuan, China. .,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, Sichuan, China.
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11
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Tan H, Xie Y, Chen F, Chen M, Yu L, Chen D, Chen J. Novel and recurrent variants identified in fetuses with central nervous system abnormalities by trios-medical exome sequencing. Clin Chim Acta 2020; 510:599-604. [PMID: 32798513 DOI: 10.1016/j.cca.2020.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 07/12/2020] [Accepted: 08/10/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Fetal central nervous system abnormalities often associated with infant death or severe disability. The etiology in fetuses with CNS abnormalities who have normal karyotypes and copy number variants (CNVs) remains unclear, which increases the difficulty in following management and the assessment of prognosis. METHOD 11 unrelated fetuses with CNS abnormalities and their parents were enrolled. Genomic DNA was obtained and then trios-medical exome sequencing (trios-MES) including 4000 genes (fetuses and their parents) was performed after both karyotyping and chromosome microarray showed negative results. RESULTS Pathogenic and likely pathogenic variants were identified in five of 11 cases (5/11, 45.5%), including five novel mutations and two recurrent mutations in ISPD, L1CAM, and GRIN2B genes. Most cases (4/5, 80%) carried one or two recessive mutations, indicating a high recurrent risk. CONCLUSION Exome sequencing should be considered for fetuses with CNS abnormalities following negative results of karyotyping and chromosome array. Trios-MES as one of exome sequencing is a potential method for the diagnosis of these fetuses.
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Affiliation(s)
- Hu Tan
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, Guangdong, China; The Medical Centre for Critical Pregnant Women in Guangzhou, Guangzhou 510150, China; Obstetrics & Gynecology Institute of Guangzhou, Guangzhou 510150, China
| | - Yinong Xie
- Department of Fetal Medicine and Prenatal Diagnosis, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Fei Chen
- Department of Fetal Medicine and Prenatal Diagnosis, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Min Chen
- Department of Fetal Medicine and Prenatal Diagnosis, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China
| | - Li Yu
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, Guangdong, China
| | - Dunjin Chen
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, Guangdong, China; The Medical Centre for Critical Pregnant Women in Guangzhou, Guangzhou 510150, China; Obstetrics & Gynecology Institute of Guangzhou, Guangzhou 510150, China.
| | - Jingsi Chen
- Key Laboratory for Major Obstetric Diseases of Guangdong Province, Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, Guangdong, China; Department of Fetal Medicine and Prenatal Diagnosis, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China; The Medical Centre for Critical Pregnant Women in Guangzhou, Guangzhou 510150, China; Obstetrics & Gynecology Institute of Guangzhou, Guangzhou 510150, China.
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12
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Shemesh OA, Linghu C, Piatkevich KD, Goodwin D, Celiker OT, Gritton HJ, Romano MF, Gao R, Yu CCJ, Tseng HA, Bensussen S, Narayan S, Yang CT, Freifeld L, Siciliano CA, Gupta I, Wang J, Pak N, Yoon YG, Ullmann JFP, Guner-Ataman B, Noamany H, Sheinkopf ZR, Park WM, Asano S, Keating AE, Trimmer JS, Reimer J, Tolias AS, Bear MF, Tye KM, Han X, Ahrens MB, Boyden ES. Precision Calcium Imaging of Dense Neural Populations via a Cell-Body-Targeted Calcium Indicator. Neuron 2020; 107:470-486.e11. [PMID: 32592656 DOI: 10.1016/j.neuron.2020.05.029] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 05/09/2019] [Accepted: 05/20/2020] [Indexed: 01/11/2023]
Abstract
Methods for one-photon fluorescent imaging of calcium dynamics can capture the activity of hundreds of neurons across large fields of view at a low equipment complexity and cost. In contrast to two-photon methods, however, one-photon methods suffer from higher levels of crosstalk from neuropil, resulting in a decreased signal-to-noise ratio and artifactual correlations of neural activity. We address this problem by engineering cell-body-targeted variants of the fluorescent calcium indicators GCaMP6f and GCaMP7f. We screened fusions of GCaMP to natural, as well as artificial, peptides and identified fusions that localized GCaMP to within 50 μm of the cell body of neurons in mice and larval zebrafish. One-photon imaging of soma-targeted GCaMP in dense neural circuits reported fewer artifactual spikes from neuropil, an increased signal-to-noise ratio, and decreased artifactual correlation across neurons. Thus, soma-targeting of fluorescent calcium indicators facilitates usage of simple, powerful, one-photon methods for imaging neural calcium dynamics.
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Affiliation(s)
- Or A Shemesh
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Department of Biological Engineering, MIT, Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; Department of Neurobiology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Changyang Linghu
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, USA
| | - Kiryl D Piatkevich
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Department of Biological Engineering, MIT, Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province, China
| | - Daniel Goodwin
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Orhan Tunc Celiker
- MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, USA
| | - Howard J Gritton
- Boston University, Department of Biomedical Engineering, Boston, MA 02215, USA
| | - Michael F Romano
- Boston University, Department of Biomedical Engineering, Boston, MA 02215, USA
| | - Ruixuan Gao
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Chih-Chieh Jay Yu
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Department of Biological Engineering, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Hua-An Tseng
- Boston University, Department of Biomedical Engineering, Boston, MA 02215, USA
| | - Seth Bensussen
- Boston University, Department of Biomedical Engineering, Boston, MA 02215, USA
| | - Sujatha Narayan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Chao-Tsung Yang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Limor Freifeld
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; Faculty of Biomedical Engineering, Technion, Haifa, Israel
| | - Cody A Siciliano
- Vanderbilt Center for Addiction Research, Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Ishan Gupta
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Department of Biological Engineering, MIT, Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Joyce Wang
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Nikita Pak
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; Department of Mechanical Engineering, MIT, Cambridge, MA, USA
| | - Young-Gyu Yoon
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; Department of Electrical Engineering and Computer Science, MIT, Cambridge, MA, USA; School of Electrical Engineering, KAIST Institute for Health Science and Technology, Daejeon, Republic of Korea
| | - Jeremy F P Ullmann
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital & Harvard Medical School, Boston, MA, USA
| | - Burcu Guner-Ataman
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Habiba Noamany
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Zoe R Sheinkopf
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Shoh Asano
- Internal Medicine Research Unit, Pfizer, Cambridge, MA, USA
| | - Amy E Keating
- Department of Biological Engineering, MIT, Cambridge, MA, USA; Department of Biology, MIT, Cambridge, MA, USA; Koch Institute, MIT, Cambridge, MA 02139, USA
| | - James S Trimmer
- Department of Physiology and Membrane Biology, University of California, Davis School of Medicine, Davis, CA, USA
| | - Jacob Reimer
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Center for Neuroscience and AI, Baylor College of Medicine, Houston, TX, USA
| | - Andreas S Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Center for Neuroscience and AI, Baylor College of Medicine, Houston, TX, USA; Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Mark F Bear
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Kay M Tye
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA; Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Xue Han
- Boston University, Department of Biomedical Engineering, Boston, MA 02215, USA
| | - Misha B Ahrens
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Edward S Boyden
- The MIT Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Department of Biological Engineering, MIT, Cambridge, MA, USA; MIT Center for Neurobiological Engineering, MIT, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA; MIT McGovern Institute for Brain Research, MIT, Cambridge, MA, USA; Koch Institute, MIT, Cambridge, MA 02139, USA.
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13
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Lorenzo DN. Cargo hold and delivery: Ankyrins, spectrins, and their functional patterning of neurons. Cytoskeleton (Hoboken) 2020; 77:129-148. [PMID: 32034889 DOI: 10.1002/cm.21602] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/01/2020] [Accepted: 02/03/2020] [Indexed: 01/12/2023]
Abstract
The highly polarized, typically very long, and nonmitotic nature of neurons present them with unique challenges in the maintenance of their homeostasis. This architectural complexity serves a rich and tightly controlled set of functions that enables their fast communication with neighboring cells and endows them with exquisite plasticity. The submembrane neuronal cytoskeleton occupies a pivotal position in orchestrating the structural patterning that determines local and long-range subcellular specialization, membrane dynamics, and a wide range of signaling events. At its center is the partnership between ankyrins and spectrins, which self-assemble with both remarkable long-range regularity and micro- and nanoscale specificity to precisely position and stabilize cell adhesion molecules, membrane transporters, ion channels, and other cytoskeletal proteins. To accomplish these generally conserved, but often functionally divergent and spatially diverse, roles these partners use a combinatorial program of a couple of dozens interacting family members, whose code is not fully unraveled. In a departure from their scaffolding roles, ankyrins and spectrins also enable the delivery of material to the plasma membrane by facilitating intracellular transport. Thus, it is unsurprising that deficits in ankyrins and spectrins underlie several neurodevelopmental, neurodegenerative, and psychiatric disorders. Here, I summarize key aspects of the biology of spectrins and ankyrins in the mammalian neuron and provide a snapshot of the latest advances in decoding their roles in the nervous system.
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Affiliation(s)
- Damaris N Lorenzo
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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14
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Shemesh OA, Tanese D, Zampini V, Linghu C, Piatkevich K, Ronzitti E, Papagiakoumou E, Boyden ES, Emiliani V. Temporally precise single-cell-resolution optogenetics. Nat Neurosci 2017; 20:1796-1806. [PMID: 29184208 PMCID: PMC5726564 DOI: 10.1038/s41593-017-0018-8] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/26/2017] [Indexed: 02/07/2023]
Abstract
Optogenetic control of individual neurons with high temporal precision within intact mammalian brain circuitry would enable powerful explorations of how neural circuits operate. Two-photon computer-generated holography enables precise sculpting of light and could in principle enable simultaneous illumination of many neurons in a network, with the requisite temporal precision to simulate accurate neural codes. We designed a high-efficacy soma-targeted opsin, finding that fusing the N-terminal 150 residues of kainate receptor subunit 2 (KA2) to the recently discovered high-photocurrent channelrhodopsin CoChR restricted expression of this opsin primarily to the cell body of mammalian cortical neurons. In combination with two-photon holographic stimulation, we found that this somatic CoChR (soCoChR) enabled photostimulation of individual cells in mouse cortical brain slices with single-cell resolution and <1-ms temporal precision. We used soCoChR to perform connectivity mapping on intact cortical circuits.
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Affiliation(s)
- Or A Shemesh
- Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
- Department of Biological Engineering, MIT, Cambridge, MA, USA
- Center for Neurobiological Engineering, MIT, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Dimitrii Tanese
- Neurophotonics Laboratory, Wave Front Engineering Microscopy Group, CNRS UMR8250, Université Paris Descartes, Paris, France
| | - Valeria Zampini
- Neurophotonics Laboratory, Wave Front Engineering Microscopy Group, CNRS UMR8250, Université Paris Descartes, Paris, France
- Institut de la Vision, UM 80, UPMC, Paris, France
| | - Changyang Linghu
- Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
- Department of Biological Engineering, MIT, Cambridge, MA, USA
- Center for Neurobiological Engineering, MIT, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Kiryl Piatkevich
- Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
- Department of Biological Engineering, MIT, Cambridge, MA, USA
- Center for Neurobiological Engineering, MIT, Cambridge, MA, USA
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA
| | - Emiliano Ronzitti
- Neurophotonics Laboratory, Wave Front Engineering Microscopy Group, CNRS UMR8250, Université Paris Descartes, Paris, France
- Institut de la Vision, UM 80, UPMC, Paris, France
| | - Eirini Papagiakoumou
- Neurophotonics Laboratory, Wave Front Engineering Microscopy Group, CNRS UMR8250, Université Paris Descartes, Paris, France
- Institut national de la santé et de la recherche médicale (Inserm), Paris, France
| | - Edward S Boyden
- Media Laboratory, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
- Department of Biological Engineering, MIT, Cambridge, MA, USA.
- Center for Neurobiological Engineering, MIT, Cambridge, MA, USA.
- Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA.
- McGovern Institute for Brain Research, MIT, Cambridge, MA, USA.
| | - Valentina Emiliani
- Neurophotonics Laboratory, Wave Front Engineering Microscopy Group, CNRS UMR8250, Université Paris Descartes, Paris, France.
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15
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Plasticity Related Gene 3 (PRG3) overcomes myelin-associated growth inhibition and promotes functional recovery after spinal cord injury. Aging (Albany NY) 2017; 8:2463-2487. [PMID: 27744421 PMCID: PMC5115901 DOI: 10.18632/aging.101066] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 09/25/2016] [Indexed: 12/14/2022]
Abstract
The Plasticity Related Gene family covers five, brain-specific, transmembrane proteins (PRG1-5, also termed LPPR1-5) that operate in neuronal plasticity during development, aging and brain trauma. Here we investigated the role of the PRG family on axonal and filopodia outgrowth. Comparative analysis revealed the strongest outgrowth induced by PRG3 (LPPR1). During development, PRG3 is ubiquitously located at the tip of neuronal processes and at the plasma membrane and declines with age. In utero electroporation of PRG3 induced dendritic protrusions and accelerated spine formations in cortical pyramidal neurons. The neurite growth promoting activity of PRG3 requires RasGRF1 (RasGEF1/Cdc25) mediated downstream signaling. Moreover, in axon collapse assays, PRG3-induced neurites resisted growth inhibitors such as myelin, Nogo-A (Reticulon/RTN-4), thrombin and LPA and impeded the RhoA-Rock-PIP5K induced neurite repulsion. Transgenic adult mice with constitutive PRG3 expression displayed strong axonal sprouting distal to a spinal cord lesion. Moreover, fostered PRG3 expression promoted complex motor-behavioral recovery compared to wild type controls as revealed in the Schnell swim test (SST). Thus, PRG3 emerges as a developmental RasGRF1-dependent conductor of filopodia formation and axonal growth enhancer. PRG3-induced neurites resist brain injury-associated outgrowth inhibitors and contribute to functional recovery after spinal cord lesions. Here, we provide evidence that PRG3 operates as an essential neuronal growth promoter in the nervous system. Maintaining PRG3 expression in aging brain may turn back the developmental clock for neuronal regeneration and plasticity.
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16
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17
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Morales DM, Silver SA, Morgan CD, Mercer D, Inder TE, Holtzman DM, Wallendorf MJ, Rao R, McAllister JP, Limbrick DD. Lumbar Cerebrospinal Fluid Biomarkers of Posthemorrhagic Hydrocephalus of Prematurity: Amyloid Precursor Protein, Soluble Amyloid Precursor Protein α, and L1 Cell Adhesion Molecule. Neurosurgery 2017; 80:82-90. [PMID: 27571524 DOI: 10.1227/neu.0000000000001415] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 06/15/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Intraventricular hemorrhage (IVH) is the most frequent, severe neurological complication of prematurity and is associated with posthemorrhagic hydrocephalus (PHH) in up to half of cases. PHH requires lifelong neurosurgical care and is associated with significant cognitive and psychomotor disability. Cerebrospinal fluid (CSF) biomarkers may provide both diagnostic information for PHH and novel insights into its pathophysiology. OBJECTIVE To explore the diagnostic ability of candidate CSF biomarkers for PHH. METHODS Concentrations of amyloid precursor protein (APP), soluble APPα (sAPPα), soluble APPβ, neural cell adhesion molecule-1 (NCAM-1), L1 cell adhesion molecule (L1CAM), tau, phosphorylated tau, and total protein (TP) were measured in lumbar CSF from neonates in 6 groups: (1) no known neurological disease (n = 33); (2) IVH grades I to II (n = 13); (3) IVH grades III to IV (n = 12); (4) PHH (n = 12); (5) ventricular enlargement without hydrocephalus (n = 10); and (6) hypoxic ischemic encephalopathy (n = 13). CSF protein levels were compared using analysis of variance, and logistic regression was performed to examine the predictive ability of each marker for PHH. RESULTS Lumbar CSF levels of APP, sAPPα, L1CAM, and TP were selectively increased in PHH compared with all other conditions (all P < .001). The sensitivity, specificity, and odds ratios of candidate CSF biomarkers for PHH were determined for APP, sAPPα, and L1CAM; cut points of 699, 514, and 113 ng/mL yielded odds ratios for PHH of 80.0, 200.0, and 68.75, respectively. CONCLUSION Lumbar CSF APP, sAPPα, L1CAM, and TP were selectively increased in PHH. These proteins, and sAPPα, in particular, hold promise as biomarkers of PHH and provide novel insight into PHH-associated neural injury and repair.
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Affiliation(s)
- Diego M Morales
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Shawgi A Silver
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Clinton D Morgan
- Depart-ment of Neurological Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Deanna Mercer
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Terri E Inder
- Department of Pediatrics, Harvard University School of Medicine, Boston, Massachusetts
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri.,Hope Center for Neurological Disorders, Washington University School of Medi-cine, St. Louis, Missouri.,Knight Alzheimer's Disease Research Center, Washing-ton University School of Medicine, St. Louis, Missouri
| | - Michael J Wallendorf
- Division of Biostat-istics, Washington University School of Medicine, St. Louis, Missouri
| | - Rakesh Rao
- Depart-ment of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - James P McAllister
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - David D Limbrick
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri.,Hope Center for Neurological Disorders, Washington University School of Medi-cine, St. Louis, Missouri.,Depart-ment of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
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18
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Patzke C, Acuna C, Giam LR, Wernig M, Südhof TC. Conditional deletion of L1CAM in human neurons impairs both axonal and dendritic arborization and action potential generation. J Exp Med 2016; 213:499-515. [PMID: 27001749 PMCID: PMC4821644 DOI: 10.1084/jem.20150951] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 02/12/2016] [Indexed: 01/02/2023] Open
Abstract
Patzke et al. create human embryonic stem cell–derived neurons that enable the generation of conditional loss-of-function mutations of L1CAM. Deletion of L1CAM impairs axonal elongation, dendritic arborization, and action potential generation. Hundreds of L1CAM gene mutations have been shown to be associated with congenital hydrocephalus, severe intellectual disability, aphasia, and motor symptoms. How such mutations impair neuronal function, however, remains unclear. Here, we generated human embryonic stem (ES) cells carrying a conditional L1CAM loss-of-function mutation and produced precisely matching control and L1CAM-deficient neurons from these ES cells. In analyzing two independent conditionally mutant ES cell clones, we found that deletion of L1CAM dramatically impaired axonal elongation and, to a lesser extent, dendritic arborization. Unexpectedly, we also detected an ∼20–50% and ∼20–30% decrease, respectively, in the levels of ankyrinG and ankyrinB protein, and observed that the size and intensity of ankyrinG staining in the axon initial segment was significantly reduced. Overexpression of wild-type L1CAM, but not of the L1CAM point mutants R1166X and S1224L, rescued the decrease in ankyrin levels. Importantly, we found that the L1CAM mutation selectively decreased activity-dependent Na+-currents, altered neuronal excitability, and caused impairments in action potential (AP) generation. Thus, our results suggest that the clinical presentations of L1CAM mutations in human patients could be accounted for, at least in part, by cell-autonomous changes in the functional development of neurons, such that neurons are unable to develop normal axons and dendrites and to generate normal APs.
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Affiliation(s)
- Christopher Patzke
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Claudio Acuna
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Louise R Giam
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
| | - Marius Wernig
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305 Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305 Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305
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19
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Christaller WAA, Vos Y, Gebre-Medhin S, Hofstra RMW, Schäfer MKE. L1 syndrome diagnosis complemented with functional analysis of L1CAM variants located to the two N-terminal Ig-like domains. Clin Genet 2016; 91:115-120. [DOI: 10.1111/cge.12763] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/15/2016] [Accepted: 02/15/2016] [Indexed: 11/30/2022]
Affiliation(s)
- W. A. A. Christaller
- Department of Anesthesiology, University Medical Center; Johannes Gutenberg-University Mainz; Mainz Germany
| | - Y. Vos
- Department of Genetics, University Medical Centre Groningen; University of Groningen; Groningen The Netherlands
| | - S. Gebre-Medhin
- Department of Clinical Genetics; University Hospital, Lund University; Lund Sweden
| | - R. M. W. Hofstra
- Department of Clinical Genetics; University of Rotterdam; Rotterdam The Netherlands
| | - M. K. E. Schäfer
- Department of Anesthesiology, University Medical Center; Johannes Gutenberg-University Mainz; Mainz Germany
- Focus program Translational Neurosciences (FTN); Johannes Gutenberg-University Mainz; Mainz Germany
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Morales DM, Holubkov R, Inder TE, Ahn HC, Mercer D, Rao R, McAllister JP, Holtzman DM, Limbrick DD. Cerebrospinal fluid levels of amyloid precursor protein are associated with ventricular size in post-hemorrhagic hydrocephalus of prematurity. PLoS One 2015; 10:e0115045. [PMID: 25738507 PMCID: PMC4349693 DOI: 10.1371/journal.pone.0115045] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 11/18/2014] [Indexed: 02/03/2023] Open
Abstract
Background Neurological outcomes of preterm infants with post-hemorrhagic hydrocephalus (PHH) remain among the worst in infancy, yet there remain few instruments to inform the treatment of PHH. We previously observed PHH-associated elevations in cerebrospinal fluid (CSF) amyloid precursor protein (APP), neural cell adhesion molecule-L1 (L1CAM), neural cell adhesion molecule-1 (NCAM-1), and other protein mediators of neurodevelopment. Objective The objective of this study was to examine the association of CSF APP, L1CAM, and NCAM-1 with ventricular size as an early step toward developing CSF markers of PHH. Methods CSF levels of APP, L1CAM, NCAM-1, and total protein (TP) were measured in 12 preterm infants undergoing PHH treatment. Ventricular size was determined using cranial ultrasounds. The relationships between CSF APP, L1CAM, and NCAM-1, occipitofrontal circumference (OFC), volume of CSF removed, and ventricular size were examined using correlation and regression analyses. Results CSF levels of APP, L1CAM, and NCAM-1 but not TP paralleled treatment-related changes in ventricular size. CSF APP demonstrated the strongest association with ventricular size, estimated by frontal-occipital horn ratio (FOR) (Pearson R = 0.76, p = 0.004), followed by NCAM-1 (R = 0.66, p = 0.02) and L1CAM (R = 0.57,p = 0.055). TP was not correlated with FOR (R = 0.02, p = 0.95). Conclusions Herein, we report the novel observation that CSF APP shows a robust association with ventricular size in preterm infants treated for PHH. The results from this study suggest that CSF APP and related proteins at once hold promise as biomarkers of PHH and provide insight into the neurological consequences of PHH in the preterm infant.
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Affiliation(s)
- Diego M. Morales
- Department of Neurological Surgery, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
| | - Richard Holubkov
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Terri E. Inder
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
| | - Haejun C. Ahn
- Department of Neurological Surgery, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
| | - Deanna Mercer
- Department of Neurological Surgery, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
| | - Rakesh Rao
- Department of Newborn Medicine, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
| | - James P. McAllister
- Department of Neurological Surgery, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
| | - David M. Holtzman
- Department of Neurology, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
- The Hope Center for Neurological Disorders, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
| | - David D. Limbrick
- Department of Neurological Surgery, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
- The Hope Center for Neurological Disorders, Washington University in St. Louis, School of Medicine, Saint Louis, Missouri, United States of America
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AlphaII-spectrin participates in the surface expression of cell adhesion molecule L1 and neurite outgrowth. Exp Cell Res 2014; 322:365-80. [DOI: 10.1016/j.yexcr.2014.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 01/11/2014] [Accepted: 01/13/2014] [Indexed: 11/22/2022]
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Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster. PLoS One 2013; 8:e76974. [PMID: 24155914 PMCID: PMC3796554 DOI: 10.1371/journal.pone.0076974] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 09/05/2013] [Indexed: 01/17/2023] Open
Abstract
A large number of different pathological L1CAM mutations have been identified that result in a broad spectrum of neurological and non-neurological phenotypes. While many of these mutations have been characterized for their effects on homophilic and heterophilic interactions, as well as expression levels in vitro, there are only few studies on their biological consequences in vivo. The single L1-type CAM gene in Drosophila, neuroglian (nrg), has distinct functions during axon guidance and synapse formation and the phenotypes of nrg mutants can be rescued by the expression of human L1CAM. We previously showed that the highly conserved intracellular FIGQY Ankyrin-binding motif is required for L1CAM-mediated synapse formation, but not for neurite outgrowth or axon guidance of the Drosophila giant fiber (GF) neuron. Here, we use the GF as a model neuron to characterize the pathogenic L120V, Y1070C, C264Y, H210Q, E309K and R184Q extracellular L1CAM missense mutations and a L1CAM protein with a disrupted ezrin-moesin-radixin (ERM) binding site to investigate the signaling requirements for neuronal development. We report that different L1CAM mutations have distinct effects on axon guidance and synapse formation. Furthermore, L1CAM homophilic binding and signaling via the ERM motif is essential for axon guidance in Drosophila. In addition, the human pathological H210Q, R184Q and Y1070C, but not the E309K and L120V L1CAM mutations affect outside-in signaling via the FIGQY Ankyrin binding domain which is required for synapse formation. Thus, the pathological phenotypes observed in humans are likely to be caused by the disruption of signaling required for both, guidance and synaptogenesis.
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Brand Y, Sung M, Chavez E, Wei E, Pak KK, Housley GD, Bodmer D, Ryan AF. Neural cell adhesion molecule L1 modulates type I but not type II inner ear spiral ganglion neurite outgrowth in an in vitro alternate choice assay. J Mol Neurosci 2013; 51:663-70. [PMID: 23760987 DOI: 10.1007/s12031-013-0040-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 05/27/2013] [Indexed: 12/17/2022]
Abstract
L1, a neural cell adhesion molecule of the immunoglobulin superfamily, is widely expressed in the nervous system and important in axonal outgrowth, guidance, synapse formation, and signaling. Gene deletion studies emphasize the significance of L1 during development of the central nervous system and L1 is crucial for the topographic targeting of retinal axons. In contrast to the brain and retina, the role of L1 in the inner ear is largely unknown. While previous studies have localized L1 in the developing inner ear of the chicken and mouse, its function during the innervation of the cochlea still remains largely unclear. We therefore investigated the functional role of L1 in the mammalian inner ear. Our aim was to determine whether or not L1 can modulate type I and/or type II spiral ganglion neuron outgrowth using an in vitro alternate choice assay. We found that L1, presented in stripe micropatterns, provide directional cues to neonatal rodent type I but not type II inner ear spiral ganglion neurites. The results suggest that L1 may play a role in axonal pathfinding of type I spiral ganglion dendrites toward their inner hair cell targets but not of type II toward the outer hair cells.
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Affiliation(s)
- Yves Brand
- Department of Surgery/Otolaryngology, UCSD School of Medicine, 9500 Gilman Drive MC0666, La Jolla, CA, 92093, USA
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Mitogen-activated protein kinase modulates ethanol inhibition of cell adhesion mediated by the L1 neural cell adhesion molecule. Proc Natl Acad Sci U S A 2013; 110:5683-8. [PMID: 23431142 DOI: 10.1073/pnas.1221386110] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
There is a genetic contribution to fetal alcohol spectrum disorders (FASD), but the identification of candidate genes has been elusive. Ethanol may cause FASD in part by decreasing the adhesion of the developmentally critical L1 cell adhesion molecule through interactions with an alcohol binding pocket on the extracellular domain. Pharmacologic inhibition or genetic knockdown of ERK2 did not alter L1 adhesion, but markedly decreased ethanol inhibition of L1 adhesion in NIH/3T3 cells and NG108-15 cells. Likewise, leucine replacement of S1248, an ERK2 substrate on the L1 cytoplasmic domain, did not decrease L1 adhesion, but abolished ethanol inhibition of L1 adhesion. Stable transfection of NIH/3T3 cells with human L1 resulted in clonal cell lines in which L1 adhesion was consistently sensitive or insensitive to ethanol for more than a decade. ERK2 activity and S1248 phosphorylation were greater in ethanol-sensitive NIH/3T3 clonal cell lines than in their ethanol-insensitive counterparts. Ethanol-insensitive cells became ethanol sensitive after increasing ERK2 activity by transfection with a constitutively active MAP kinase kinase 1. Finally, embryos from two substrains of C57BL mice that differ in susceptibility to ethanol teratogenesis showed corresponding differences in MAPK activity. Our data suggest that ERK2 phosphorylation of S1248 modulates ethanol inhibition of L1 adhesion by inside-out signaling and that differential regulation of ERK2 signaling might contribute to genetic susceptibility to FASD. Moreover, identification of a specific locus that regulates ethanol sensitivity, but not L1 function, might facilitate the rational design of drugs that block ethanol neurotoxicity.
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25
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Tagliavacca L, Colombo F, Racchetti G, Meldolesi J. L1CAM and its cell-surface mutants: new mechanisms and effects relevant to the physiology and pathology of neural cells. J Neurochem 2012; 124:397-409. [PMID: 22973895 PMCID: PMC3557714 DOI: 10.1111/jnc.12015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 09/05/2012] [Accepted: 09/08/2012] [Indexed: 11/27/2022]
Abstract
The L1 syndrome, a genetic disease that affects 1/30 000 newborn males, is sustained by numerous missense mutations of L1 cell adhesion molecule (L1CAM), an adhesion surface protein active also in transmembrane signaling, essential for the development and function of neurons. To investigate the cell biology of L1CAM, we employed a high RE1-silencing transcription (factor) clone of the pheochromocytoma PC12 line, defective in L1CAM expression and neurite outgrowth. The clone was transfected with wild-type L1CAM and four missense, disease-inducing point mutants encoding proteins distributed to the cell surface. The mutant-expressing cells, defective in adhesion to extracellular matrix proteins and in migration, exhibited unchanged proliferation. The nerve growth factor (NGF)-induced neurite outgrowth was re-established in defective clone cells transfected with the wild-type and the H210Q and I219T L1CAMs mutants, but not in the others. The stimulated outgrowth was confirmed in a second defective PC12 clone over-expressing the NGF receptor TrkA, treated with NGF and/or a recombinant L1CAM chimera. These results revealed a new function of L1CAM, a positive, robust and dose-dependent modulation of the TrkA receptor activated spontaneously or by NGF. The variable effects observed with the different L1CAM mutants suggest that this function contributes to the marked heterogeneity of symptoms and severity observed in the patients affected by the L1 syndrome.
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Affiliation(s)
- Luigina Tagliavacca
- Department of Neuroscience, Vita-Salute San Raffaele University and San Raffaele Institute, Milano, Italy
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Functional inactivation of the genome-wide association study obesity gene neuronal growth regulator 1 in mice causes a body mass phenotype. PLoS One 2012; 7:e41537. [PMID: 22844493 PMCID: PMC3402391 DOI: 10.1371/journal.pone.0041537] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 06/22/2012] [Indexed: 12/21/2022] Open
Abstract
To date, genome-wide association studies (GWAS) have identified at least 32 novel loci for obesity and body mass-related traits. However, the causal genetic variant and molecular mechanisms of specific susceptibility genes in relation to obesity are yet to be fully confirmed and characterised. Here, we examined whether the candidate gene NEGR1 encoding the neuronal growth regulator 1, also termed neurotractin or Kilon, accounts for the obesity association. To characterise the function of NEGR1 for body weight control in vivo, we generated two novel mutant mouse lines, including a constitutive NEGR1-deficient mouse line as well as an ENU-mutagenised line carrying a loss-of-function mutation (Negr1-I87N) and performed metabolic phenotypic analyses. Ablation of NEGR1 results in a small but steady reduction of body mass in both mutant lines, accompanied with a small reduction in body length in the Negr1-I87N mutants. Magnetic resonance scanning reveals that the reduction of body mass in Negr1-I87N mice is due to a reduced proportion of lean mass. Negr1-I87N mutants display reduced food intake and physical activity while normalised energy expenditure remains unchanged. Expression analyses confirmed the brain-specific distribution of NEGR1 including strong expression in the hypothalamus. In vitro assays show that NEGR1 promotes cell-cell adhesion and neurite growth of hypothalamic neurons. Our results indicate a role of NEGR1 in the control of body weight and food intake. This study provides evidence that supports the link of the GWAS candidate gene NEGR1 with body weight control.
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Role of L1CAM for axon sprouting and branching. Cell Tissue Res 2012; 349:39-48. [DOI: 10.1007/s00441-012-1345-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 01/25/2012] [Indexed: 01/02/2023]
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Seabold GK, Wang PY, Petralia RS, Chang K, Zhou A, McDermott MI, Wang YX, Milgram SL, Wenthold RJ. Dileucine and PDZ-binding motifs mediate synaptic adhesion-like molecule 1 (SALM1) trafficking in hippocampal neurons. J Biol Chem 2012; 287:4470-84. [PMID: 22174418 PMCID: PMC3281672 DOI: 10.1074/jbc.m111.279661] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 11/22/2011] [Indexed: 12/18/2022] Open
Abstract
Synaptic adhesion-like molecules (SALMs) are a family of cell adhesion molecules involved in neurite outgrowth and synapse formation. Of the five family members, only SALM1, -2, and -3 contain a cytoplasmic C-terminal PDZ-binding motif. We have found that SALM1 is unique among the SALMs because deletion of its PDZ-binding motif (SALM1ΔPDZ) blocks its surface expression in heterologous cells. When expressed in hippocampal neurons, SALM1ΔPDZ had decreased surface expression in dendrites and the cell soma but not in axons, suggesting that the PDZ-binding domain may influence cellular trafficking of SALMs to specific neuronal locations. Endoglycosidase H digestion assays indicated that SALM1ΔPDZ is retained in the endoplasmic reticulum (ER) in heterologous cells. However, when the entire C-terminal tail of SALM1 was deleted, SALM1 was detected on the cell surface. Using serial deletions, we identified a region of SALM1 that contains a putative dileucine ER retention motif, which is not present in the other SALMs. Mutation of this DXXXLL motif allowed SALM1 to leave the ER and enhanced its surface expression in heterologous cells and neurons. An increase in the number of protrusions at the dendrites and cell body was observed when this SALM1 mutant was expressed in hippocampal neurons. With electron microscopy, these protrusions appeared to be irregular, enlarged spines and filopodia. Thus, enrichment of SALM1 on the cell surface affects dendritic arborization, and intracellular motifs regulate its dendritic versus axonal localization.
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Affiliation(s)
- Gail K Seabold
- Laboratory of Neurochemistry, NIDCD/National Institutes of Health, 50 South Dr., Bldg. 50, Rm. 4144, Bethesda, MD20892-8027, USA.
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Marx M, Diestel S, Bozon M, Keglowich L, Drouot N, Bouché E, Frebourg T, Minz M, Saugier-Veber P, Castellani V, Schäfer MKE. Pathomechanistic characterization of two exonic L1CAM variants located in trans in an obligate carrier of X-linked hydrocephalus. Neurogenetics 2012; 13:49-59. [PMID: 22222883 DOI: 10.1007/s10048-011-0307-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 12/07/2011] [Indexed: 11/29/2022]
Abstract
Mutations in the gene encoding the neural cell adhesion molecule L1CAM cause several neurological disorders collectively referred to as L1 syndrome. We report here a family case of X-linked hydrocephalus in which an obligate female carrier has two exonic L1CAM missense mutations in trans substituting amino acids in the first (p.W635C) or second (p.V768I) fibronectin-type III domains. We performed various biochemical and cell biological in vitro assays to evaluate the pathogenicity of these variants. Mutant L1-W635C protein accumulates in the endoplasmic reticulum (ER), is not transported into axons, and fails to promote L1CAM-mediated cell-cell adhesion as well as neurite growth. Immunoprecipitation experiments show that L1-W635C associates with the molecular ER chaperone calnexin and is modified by poly-ubiquitination. The mutant L1-V768I protein localizes at the cell surface, is not retained in the ER, and promotes neurite growth similar to wild-type L1CAM. However, the p.V768I mutation impairs L1CAM-mediated cell-cell adhesion albeit less severe than L1-W635C. These data indicate that p.W635C is a novel loss-of-function L1 syndrome mutation. The p.V768I mutation may represent a non-pathogenic variant or a variant associated with low penetrance. The poly-ubiquitination of L1-W635C and its association with the ER chaperone calnexin provide further insights into the molecular mechanisms underlying defective cell surface trafficking of L1CAM in L1 syndrome.
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Affiliation(s)
- Mariola Marx
- Institute of Anatomy and Cell Biology, Center for Neurosciences, University of Freiburg, Freiburg, Germany
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Plank C, Zelphati O, Mykhaylyk O. Magnetically enhanced nucleic acid delivery. Ten years of magnetofection-progress and prospects. Adv Drug Deliv Rev 2011; 63:1300-31. [PMID: 21893135 PMCID: PMC7103316 DOI: 10.1016/j.addr.2011.08.002] [Citation(s) in RCA: 251] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 08/18/2011] [Accepted: 08/19/2011] [Indexed: 12/28/2022]
Abstract
Nucleic acids carry the building plans of living systems. As such, they can be exploited to make cells produce a desired protein, or to shut down the expression of endogenous genes or even to repair defective genes. Hence, nucleic acids are unique substances for research and therapy. To exploit their potential, they need to be delivered into cells which can be a challenging task in many respects. During the last decade, nanomagnetic methods for delivering and targeting nucleic acids have been developed, methods which are often referred to as magnetofection. In this review we summarize the progress and achievements in this field of research. We discuss magnetic formulations of vectors for nucleic acid delivery and their characterization, mechanisms of magnetofection, and the application of magnetofection in viral and nonviral nucleic acid delivery in cell culture and in animal models. We summarize results that have been obtained with using magnetofection in basic research and in preclinical animal models. Finally, we describe some of our recent work and end with some conclusions and perspectives.
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Accumulation of wildtype and ALS-linked mutated VAPB impairs activity of the proteasome. PLoS One 2011; 6:e26066. [PMID: 21998752 PMCID: PMC3187839 DOI: 10.1371/journal.pone.0026066] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 09/19/2011] [Indexed: 11/19/2022] Open
Abstract
Cellular homeostasis relies on a tight control of protein synthesis, folding and degradation, in which the endoplasmic reticulum (ER) quality control and the ubiquitin proteasome system (UPS) have an instrumental function. ER stress and aberrant accumulation of misfolded proteins represent a pathological signature of amyotrophic lateral sclerosis (ALS), a fatal paralytic disorder caused by the selective degeneration of motoneurons in the brain and spinal cord. Mutations in the ER-resident protein VAPB have been associated with familial forms of the disease. ALS-linked mutations cause VAPB to form cytoplasmic aggregates. We previously demonstrated that viral-mediated expression of both wildtype and mutant human VAPB (hVAPB) leads to an ER stress response that contributes to the selective death of motoneurons. However, the mechanisms behind ER stress, defective UPS and hVAPB-associated motoneuron degeneration remain elusive. Here, we show that the overexpression of wildtype and mutated hVAPB, which is found to be less stable than the wildtype protein, leads to the abnormal accumulation of ubiquitin and ubiquitin-like protein conjugates in non-human primate cells. We observed that overexpression of both forms of hVAPB elicited an ER stress response. Treatment of wildtype and mutated hVAPB expressing cells with the ER stress inhibitor salubrinal diminished the burden of ubiquitinated proteins, suggesting that ER stress contributes to the impairment of proteasome function. We also found that both wildtype and mutated hVAPB can associate with the 20S proteasome, which was found to accumulate at the ER with wildtype hVAPB or in mutant hVAPB aggregates. Our results suggest that ER stress and corruption of the proteasome function might contribute to the aberrant protein homeostasis associated with hVAPB.
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Itoh K, Fujisaki K, Watanabe M. Human L1CAM carrying the missense mutations of the fibronectin-like type III domains is localized in the endoplasmic reticulum and degraded by polyubiquitylation. J Neurosci Res 2011; 89:1637-45. [PMID: 21688291 DOI: 10.1002/jnr.22695] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 04/11/2011] [Accepted: 04/15/2011] [Indexed: 11/09/2022]
Abstract
Any mutations in the human neural cell adhesion molecule L1 (hL1CAM) gene might cause various types of serious neurological syndromes in humans, characterized by increased mortality, mental retardation, and various malformations of the nervous system. Such missense mutations often cause severe abnormalities or even fatalities, and the reason for this may be a disruption of the adhesive function of L1CAM resulting from a misdirection of the degradative pathway. Transfection studies using neuroblastoma N2a cells demonstrated that hL1CAM carrying the missense mutations in the fibronectin-like type III (FnIII) domains most likely is located within the endoplasmic reticulum (ER), but it is less well expressed on the cell surface. One mutant, L935P, in the fourth FnIII domain, was chosen from six mutants (K655 and G698 at Fn1, L935P and P941 at Fn4, W1036 and Y1070 at Fn5) in the FnIII domains to study in detail the functions of hL1CAM(200 kDa) , such as the intracellular traffic and degradation, because only a single band at 200 kDa was detected in the hL1CAM(L935P) -transfected cells. hL1CAM(200 kDa) is expressed predominantly in the ER but not on the cell surface. In addition, this missense mutated hL1CAM(200 kDa) is polyubiquitylated at some sites in the extracellular domain and thus becomes degraded by proteasomes via the ER-associated degradation pathway. These observations demonstrate that the missense mutations of hL1CAM in the FnIII domain may cause the resultant pathogenesis because of a loss of expression on the cell surface resulting from misrouting to the degradative pathway.
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Affiliation(s)
- Kouichi Itoh
- Laboratory of Molecular and Cellular Neurosciences, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-city, Kagawa, Japan.
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Full-length L1CAM and not its Δ2Δ27 splice variant promotes metastasis through induction of gelatinase expression. PLoS One 2011; 6:e18989. [PMID: 21541352 PMCID: PMC3081839 DOI: 10.1371/journal.pone.0018989] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 03/24/2011] [Indexed: 01/09/2023] Open
Abstract
Tumour-specific splicing is known to contribute to cancer progression. In the case of the L1 cell adhesion molecule (L1CAM), which is expressed in many human tumours and often linked to bad prognosis, alternative splicing results in a full-length form (FL-L1CAM) and a splice variant lacking exons 2 and 27 (SV-L1CAM). It has not been elucidated so far whether SV-L1CAM, classically considered as tumour-associated, or whether FL-L1CAM is the metastasis-promoting isoform. Here, we show that both variants were expressed in human ovarian carcinoma and that exposure of tumour cells to pro-metastatic factors led to an exclusive increase of FL-L1CAM expression. Selective overexpression of one isoform in different tumour cells revealed that only FL-L1CAM promoted experimental lung and/or liver metastasis in mice. In addition, metastasis formation upon up-regulation of FL-L1CAM correlated with increased invasive potential and elevated Matrix metalloproteinase (MMP)-2 and -9 expression and activity in vitro as well as enhanced gelatinolytic activity in vivo. In conclusion, we identified FL-L1CAM as the metastasis-promoting isoform, thereby exemplifying that high expression of a so-called tumour-associated variant, here SV-L1CAM, is not per se equivalent to a decisive role of this isoform in tumour progression.
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