Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptors
Abstract Background Seizures are associated with a decrease in γ-aminobutyric type A acid receptors (GABAaRs) on the neuronal surface, which may be regulated by enhanced internalization of GABAaRs. When interactions between GABAaR subunit α-1 (GABRA1) and postsynaptic scaffold proteins are weakened,...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2023-10-01
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| Series: | Journal of Translational Medicine |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12967-023-04596-4 |
| _version_ | 1797556862527209472 |
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| author | Sijun Li Xing Wei Hongmi Huang Lin Ye Meigang Ma Lanfeng Sun Yuling Lu Yuan Wu |
| author_facet | Sijun Li Xing Wei Hongmi Huang Lin Ye Meigang Ma Lanfeng Sun Yuling Lu Yuan Wu |
| author_sort | Sijun Li |
| collection | DOAJ |
| description | Abstract Background Seizures are associated with a decrease in γ-aminobutyric type A acid receptors (GABAaRs) on the neuronal surface, which may be regulated by enhanced internalization of GABAaRs. When interactions between GABAaR subunit α-1 (GABRA1) and postsynaptic scaffold proteins are weakened, the α1-containing GABAaRs leave the postsynaptic membrane and are internalized. Previous evidence suggested that neuroplastin (NPTN) promotes the localization of GABRA1 on the postsynaptic membrane. However, the association between NPTN and GABRA1 in seizures and its effect on the internalization of α1-containing GABAaRs on the neuronal surface has not been studied before. Methods An in vitro seizure model was constructed using magnesium-free extracellular fluid, and an in vivo model of status epilepticus (SE) was constructed using pentylenetetrazole (PTZ). Additionally, in vitro and in vivo NPTN-overexpression models were constructed. Electrophysiological recordings and internalization assays were performed to evaluate the action potentials and miniature inhibitory postsynaptic currents of neurons, as well as the intracellular accumulation ratio of α1-containing GABAaRs in neurons. Western blot analysis was performed to detect the expression of GABRA1 and NPTN both in vitro and in vivo. Immunofluorescence co-localization analysis and co-immunoprecipitation were performed to evaluate the interaction between GABRA1 and NPTN. Results The expression of GABRA1 was found to be decreased on the neuronal surface both in vivo and in vitro seizure models. In the in vitro seizure model, α1-containing GABAaRs showed increased internalization. NPTN expression was found to be positively correlated with GABRA1 expression on the neuronal surface both in vivo and in vitro seizure models. In addition, NPTN overexpression alleviated seizures and NPTN was shown to bind to GABRA1 to form protein complexes that can be disrupted during seizures in both in vivo and in vitro models. Furthermore, NPTN was found to inhibit the internalization of α1-containing GABAaRs in the in vitro seizure model. Conclusion Our findings provide evidence that NPTN may exert antiepileptic effects by binding to GABRA1 to inhibit the internalization of α1-containing GABAaRs. Graphical Abstract |
| first_indexed | 2024-03-10T17:08:56Z |
| format | Article |
| id | doaj.art-8b55ba7abecc47e2b1425f981fb53c18 |
| institution | Directory Open Access Journal |
| issn | 1479-5876 |
| language | English |
| last_indexed | 2024-03-10T17:08:56Z |
| publishDate | 2023-10-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Translational Medicine |
| spelling | doaj.art-8b55ba7abecc47e2b1425f981fb53c182023-11-20T10:44:07ZengBMCJournal of Translational Medicine1479-58762023-10-0121111610.1186/s12967-023-04596-4Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptorsSijun Li0Xing Wei1Hongmi Huang2Lin Ye3Meigang Ma4Lanfeng Sun5Yuling Lu6Yuan Wu7Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityDepartment of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityDepartment of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityDepartment of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityDepartment of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityDepartment of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityDepartment of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityDepartment of Neurology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical UniversityAbstract Background Seizures are associated with a decrease in γ-aminobutyric type A acid receptors (GABAaRs) on the neuronal surface, which may be regulated by enhanced internalization of GABAaRs. When interactions between GABAaR subunit α-1 (GABRA1) and postsynaptic scaffold proteins are weakened, the α1-containing GABAaRs leave the postsynaptic membrane and are internalized. Previous evidence suggested that neuroplastin (NPTN) promotes the localization of GABRA1 on the postsynaptic membrane. However, the association between NPTN and GABRA1 in seizures and its effect on the internalization of α1-containing GABAaRs on the neuronal surface has not been studied before. Methods An in vitro seizure model was constructed using magnesium-free extracellular fluid, and an in vivo model of status epilepticus (SE) was constructed using pentylenetetrazole (PTZ). Additionally, in vitro and in vivo NPTN-overexpression models were constructed. Electrophysiological recordings and internalization assays were performed to evaluate the action potentials and miniature inhibitory postsynaptic currents of neurons, as well as the intracellular accumulation ratio of α1-containing GABAaRs in neurons. Western blot analysis was performed to detect the expression of GABRA1 and NPTN both in vitro and in vivo. Immunofluorescence co-localization analysis and co-immunoprecipitation were performed to evaluate the interaction between GABRA1 and NPTN. Results The expression of GABRA1 was found to be decreased on the neuronal surface both in vivo and in vitro seizure models. In the in vitro seizure model, α1-containing GABAaRs showed increased internalization. NPTN expression was found to be positively correlated with GABRA1 expression on the neuronal surface both in vivo and in vitro seizure models. In addition, NPTN overexpression alleviated seizures and NPTN was shown to bind to GABRA1 to form protein complexes that can be disrupted during seizures in both in vivo and in vitro models. Furthermore, NPTN was found to inhibit the internalization of α1-containing GABAaRs in the in vitro seizure model. Conclusion Our findings provide evidence that NPTN may exert antiepileptic effects by binding to GABRA1 to inhibit the internalization of α1-containing GABAaRs. Graphical Abstracthttps://doi.org/10.1186/s12967-023-04596-4Seizuresγ-aminobutyric type A acid receptorsNeuroplastinInternalization |
| spellingShingle | Sijun Li Xing Wei Hongmi Huang Lin Ye Meigang Ma Lanfeng Sun Yuling Lu Yuan Wu Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptors Journal of Translational Medicine Seizures γ-aminobutyric type A acid receptors Neuroplastin Internalization |
| title | Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptors |
| title_full | Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptors |
| title_fullStr | Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptors |
| title_full_unstemmed | Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptors |
| title_short | Neuroplastin exerts antiepileptic effects through binding to the α1 subunit of GABA type A receptors to inhibit the internalization of the receptors |
| title_sort | neuroplastin exerts antiepileptic effects through binding to the α1 subunit of gaba type a receptors to inhibit the internalization of the receptors |
| topic | Seizures γ-aminobutyric type A acid receptors Neuroplastin Internalization |
| url | https://doi.org/10.1186/s12967-023-04596-4 |
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