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Reduced expression of perineuronal nets in the normotopic somatosensory cortex of the tish rat. Brain Res 2023; 1800:148179. [PMID: 36511312 DOI: 10.1016/j.brainres.2022.148179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 11/20/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
The tish (telencephalic internal structural heterotopia) rat is a naturally occurring and unique model of a malformation of cortical development (MCD) arising from a sponeantous mutation in the Eml1 gene. Tish rats are characterized by a macroscopic bilateral heterotopic dysplastic cortex (HDCx) and an overlaying, intact normotopic neocortex (NNCx). These two cortices are functional and have been reported to innervate and establish connections with subcortical regions including the thalamus, resulting in a dual-cortical representation. Additionally, impaired GABAergic neurotransmission and early-onset spike wave discharge bursts have been reported in developing tish rats. Perineuronal nets (PNNs) are specialized extraceullar matrix structures that predominately surround and stabilize parvalbumin-positive (PV+) GABAergic interneurons and are essential components of the neural landscape. Here, we report a significant reduction in the average number of WFA+-PNNs in the normotopic somatosensory cortex (NSSCx) of the tish rat at two developmental time points, P16 and P35, corresponding to a decrease in the number of PV+ interneurons ensheathed by a PNN in the NSSCx. Compared with control animals, PNN expression was partially, but significantly restored following treatment with insulin-like growth factor 1 (IGF-1). These data suggest that the 'dual cortical representation' in the setting of an MCD reduces the cortical activation necessary for proper PNN expression likely contributing to the impairments in GABAergic neurotransmission and network excitability previously identified in the tish rat.
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Yin H, Zhang T, Wang H, Hu X, Hou X, Fang X, Yin Y, Li H, Shi L, Su YQ. Echinoderm Microtubule Associated Protein Like 1 Is Indispensable for Oocyte Spindle Assembly and Meiotic Progression in Mice. Front Cell Dev Biol 2021; 9:687522. [PMID: 34124073 PMCID: PMC8194061 DOI: 10.3389/fcell.2021.687522] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/04/2021] [Indexed: 12/02/2022] Open
Abstract
Completion of the first meiosis is an essential prerequisite for producing a functionally normal egg for fertilization and embryogenesis, but the precise mechanisms governing oocyte meiotic progression remains largely unclear. Here, we report that echinoderm microtubule associated protein (EMAP) like 1 (EML1), a member of the conserved EMAP family proteins, plays a crucial role in the control of oocyte meiotic progression in the mouse. Female mice carrying an ENU-induced nonsense mutation (c.1956T > A; p.Tyr652∗) of Eml1 are infertile, and the majority of their ovulated oocytes contain abnormal spindles and misaligned chromosomes. In accordance with the mutant oocyte phenotype, we find that EML1 is colocalized with spindle microtubules during the process of normal oocyte meiotic maturation, and knockdown (KD) of EML1 by specific morpholinos in the fully grown oocytes (FGOs) disrupts the integrity of spindles, and delays meiotic progression. Moreover, EML1-KD oocytes fail to progress to metaphase II (MII) stage after extrusion of the first polar body, but enter into interphase and form a pronucleus containing decondensed chromatins. Further analysis shows that EML1-KD impairs the recruitment of γ-tubulin and pericentrin to the spindle poles, as well as the attachment of kinetochores to microtubules and the proper inactivation of spindle assembly checkpoint at metaphase I (MI). The loss of EML1 also compromises the activation of maturation promoting factor around the time of oocyte resumption and completion of the first meiosis, which, when corrected by WEE1/2 inhibitor PD166285, efficiently rescues the phenotype of oocyte delay of meiotic resumption and inability of reaching MII. Through IP- mass spectrometry analysis, we identified that EML1 interacts with nuclear distribution gene C (NUDC), a critical mitotic regulator in somatic cells, and EML1-KD disrupts the specific localization of NUDC at oocyte spindles. Taken together, these data suggest that EML1 regulates acentrosomal spindle formation and the progression of meiosis to MII in mammalian oocytes, which is likely mediated by distinct mechanisms.
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Affiliation(s)
- Hong Yin
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Teng Zhang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Hao Wang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Xin Hu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Xuan Hou
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Xianbao Fang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Yaoxue Yin
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Hui Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Lanying Shi
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - You-Qiang Su
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
- Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
- Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, China
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Markus F, Kannengießer A, Näder P, Atigbire P, Scholten A, Vössing C, Bültmann E, Korenke GC, Owczarek-Lipska M, Neidhardt J. A novel missense variant in the EML1 gene associated with bilateral ribbon-like subcortical heterotopia leads to ciliary defects. J Hum Genet 2021; 66:1159-1167. [PMID: 34211111 PMCID: PMC8612930 DOI: 10.1038/s10038-021-00947-5] [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: 03/08/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 02/06/2023]
Abstract
Heterotopia is a brain malformation caused by a failed migration of cortical neurons during development. Clinical symptoms of heterotopia vary in severity of intellectual disability and may be associated with epileptic disorders. Abnormal neuronal migration is known to be associated with mutations in the doublecortin gene (DCX), the platelet-activating factor acetylhydrolase gene (PAFAH1B1), or tubulin alpha-1A gene (TUBA1A). Recently, a new gene encoding echinoderm microtubule-associated protein-like 1 (EML1) was reported to cause a particular form of subcortical heterotopia, the ribbon-like subcortical heterotopia (RSH). EML1 mutations are inherited in an autosomal recessive manner. Only six unrelated EML1-associated heterotopia-affected families were reported so far. The EML1 protein is a member of the microtubule-associated proteins family, playing an important role in microtubule assembly and stabilization as well as in mitotic spindle formation in interphase. Herein, we present a novel homozygous missense variant in EML1 (NM_004434.2: c.692G>A, NP_004425.2: p.Gly231Asp) identified in a male RSH-affected patient. Our clinical and molecular findings confirm the genotype-phenotype associations of EML1 mutations and RSH. Analyses of patient-derived fibroblasts showed the significantly reduced length of primary cilia. In addition, our results presented, that the mutated EML1 protein did not change binding capacities with tubulin. The data described herein will expand the mutation spectrum of the EML1 gene and provide further insight into molecular and cellular bases of the pathogenic mechanisms underlying RSH.
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Affiliation(s)
- Fenja Markus
- grid.5560.60000 0001 1009 3608Junior Research Group, Genetics of Childhood Brain Malformations, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany ,grid.5560.60000 0001 1009 3608Human Genetics, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Annika Kannengießer
- grid.5560.60000 0001 1009 3608Junior Research Group, Genetics of Childhood Brain Malformations, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany ,grid.5560.60000 0001 1009 3608Human Genetics, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Patricia Näder
- grid.5560.60000 0001 1009 3608Human Genetics, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Paul Atigbire
- grid.5560.60000 0001 1009 3608Human Genetics, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Alexander Scholten
- grid.5560.60000 0001 1009 3608Division of Biochemistry, Biochemistry of signal transduction/neurosensory processes, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Christine Vössing
- grid.5560.60000 0001 1009 3608Human Genetics, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Eva Bültmann
- grid.10423.340000 0000 9529 9877Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - G. Christoph Korenke
- grid.419838.f0000 0000 9806 6518Department of Neuropediatrics, University Children’s Hospital, Klinikum Oldenburg, Oldenburg, Germany
| | - Marta Owczarek-Lipska
- grid.5560.60000 0001 1009 3608Junior Research Group, Genetics of Childhood Brain Malformations, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany ,grid.5560.60000 0001 1009 3608Human Genetics, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany ,grid.5560.60000 0001 1009 3608Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
| | - John Neidhardt
- grid.5560.60000 0001 1009 3608Human Genetics, Faculty VI-School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany ,grid.5560.60000 0001 1009 3608Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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