Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal development
Abstract Background Neurons are highly specialized cells with a complex morphology generated by various membrane trafficking steps. They contain Golgi outposts in dendrites, which are formed from somatic Golgi tubules. In trafficking membrane fusion is mediated by a specific combination of SNARE pro...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2022-11-01
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| Series: | Neural Development |
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| Online Access: | https://doi.org/10.1186/s13064-022-00168-2 |
| _version_ | 1811304539367669760 |
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| author | Christian Bollmann Susanne Schöning Katharina Kotschnew Julia Grosse Nicole Heitzig Gabriele Fischer von Mollard |
| author_facet | Christian Bollmann Susanne Schöning Katharina Kotschnew Julia Grosse Nicole Heitzig Gabriele Fischer von Mollard |
| author_sort | Christian Bollmann |
| collection | DOAJ |
| description | Abstract Background Neurons are highly specialized cells with a complex morphology generated by various membrane trafficking steps. They contain Golgi outposts in dendrites, which are formed from somatic Golgi tubules. In trafficking membrane fusion is mediated by a specific combination of SNARE proteins. A functional SNARE complex contains four different helices, one from each SNARE subfamily (R-, Qa, Qb and Qc). Loss of the two Qb SNAREs vti1a and vti1b from the Golgi apparatus and endosomes leads to death at birth in mice with massive neurodegeneration in peripheral ganglia and defective axon tracts. Methods Hippocampal and cortical neurons were isolated from Vti1a −/− Vti1b −/− double deficient, Vti1a −/− Vti1b +/− , Vti1a +/− Vti1b −/− and Vti1a +/− Vti1b +/− double heterozygous embryos. Neurite outgrowth was determined in cortical neurons and after stimulation with several neurotrophic factors or the Rho-associated protein kinase ROCK inhibitor Y27632, which induces exocytosis of enlargeosomes, in hippocampal neurons. Moreover, postsynaptic densities were isolated from embryonic Vti1a −/− Vti1b −/− and Vti1a +/− Vti1b +/− control forebrains and analyzed by western blotting. Results Golgi outposts were present in Vti1a −/− Vti1b +/− and Vti1a +/− Vti1b −/− dendrites of hippocampal neurons but not detected in the absence of vti1a and vti1b. The length of neurites was significantly shorter in double deficient cortical neurons. These defects were not observed in Vti1a −/− Vti1b +/− and Vti1a +/− Vti1b −/− neurons. NGF, BDNF, NT-3, GDNF or Y27632 as stimulator of enlargeosome secretion did not increase the neurite length in double deficient hippocampal neurons. Vti1a −/− Vti1b −/− postsynaptic densities contained similar amounts of scaffold proteins, AMPA receptors and NMDA receptors compared to Vti1a +/− Vti1b +/− , but much more TrkB, which is the receptor for BDNF. Conclusion The absence of Golgi outposts did not affect the amount of AMPA and NMDA receptors in postsynaptic densities. Even though TrkB was enriched, BDNF was not able to stimulate neurite elongation in Vti1a −/− Vti1b −/− neurons. Vti1a or vti1b function as the missing Qb-SNARE together with VAMP-4 (R-SNARE), syntaxin 16 (Qa-SNARE) and syntaxin 6 (Qc-SNARE) in induced neurite outgrowth. Our data show the importance of vti1a or vti1b for two pathways of neurite elongation. |
| first_indexed | 2024-04-13T08:08:57Z |
| format | Article |
| id | doaj.art-62559d8939d5416b9d1783c81405db02 |
| institution | Directory Open Access Journal |
| issn | 1749-8104 |
| language | English |
| last_indexed | 2024-04-13T08:08:57Z |
| publishDate | 2022-11-01 |
| publisher | BMC |
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| series | Neural Development |
| spelling | doaj.art-62559d8939d5416b9d1783c81405db022022-12-22T02:55:03ZengBMCNeural Development1749-81042022-11-0117111310.1186/s13064-022-00168-2Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal developmentChristian Bollmann0Susanne Schöning1Katharina Kotschnew2Julia Grosse3Nicole Heitzig4Gabriele Fischer von Mollard5Biochemistry III, Department of Chemistry, Bielefeld UniversityBiochemistry III, Department of Chemistry, Bielefeld UniversityBiochemistry III, Department of Chemistry, Bielefeld UniversityBiochemistry III, Department of Chemistry, Bielefeld UniversityBiochemistry III, Department of Chemistry, Bielefeld UniversityBiochemistry III, Department of Chemistry, Bielefeld UniversityAbstract Background Neurons are highly specialized cells with a complex morphology generated by various membrane trafficking steps. They contain Golgi outposts in dendrites, which are formed from somatic Golgi tubules. In trafficking membrane fusion is mediated by a specific combination of SNARE proteins. A functional SNARE complex contains four different helices, one from each SNARE subfamily (R-, Qa, Qb and Qc). Loss of the two Qb SNAREs vti1a and vti1b from the Golgi apparatus and endosomes leads to death at birth in mice with massive neurodegeneration in peripheral ganglia and defective axon tracts. Methods Hippocampal and cortical neurons were isolated from Vti1a −/− Vti1b −/− double deficient, Vti1a −/− Vti1b +/− , Vti1a +/− Vti1b −/− and Vti1a +/− Vti1b +/− double heterozygous embryos. Neurite outgrowth was determined in cortical neurons and after stimulation with several neurotrophic factors or the Rho-associated protein kinase ROCK inhibitor Y27632, which induces exocytosis of enlargeosomes, in hippocampal neurons. Moreover, postsynaptic densities were isolated from embryonic Vti1a −/− Vti1b −/− and Vti1a +/− Vti1b +/− control forebrains and analyzed by western blotting. Results Golgi outposts were present in Vti1a −/− Vti1b +/− and Vti1a +/− Vti1b −/− dendrites of hippocampal neurons but not detected in the absence of vti1a and vti1b. The length of neurites was significantly shorter in double deficient cortical neurons. These defects were not observed in Vti1a −/− Vti1b +/− and Vti1a +/− Vti1b −/− neurons. NGF, BDNF, NT-3, GDNF or Y27632 as stimulator of enlargeosome secretion did not increase the neurite length in double deficient hippocampal neurons. Vti1a −/− Vti1b −/− postsynaptic densities contained similar amounts of scaffold proteins, AMPA receptors and NMDA receptors compared to Vti1a +/− Vti1b +/− , but much more TrkB, which is the receptor for BDNF. Conclusion The absence of Golgi outposts did not affect the amount of AMPA and NMDA receptors in postsynaptic densities. Even though TrkB was enriched, BDNF was not able to stimulate neurite elongation in Vti1a −/− Vti1b −/− neurons. Vti1a or vti1b function as the missing Qb-SNARE together with VAMP-4 (R-SNARE), syntaxin 16 (Qa-SNARE) and syntaxin 6 (Qc-SNARE) in induced neurite outgrowth. Our data show the importance of vti1a or vti1b for two pathways of neurite elongation.https://doi.org/10.1186/s13064-022-00168-2Neurite outgrowthGolgi outpostPostsynaptic densityEnlargeosomeY27632SNARE |
| spellingShingle | Christian Bollmann Susanne Schöning Katharina Kotschnew Julia Grosse Nicole Heitzig Gabriele Fischer von Mollard Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal development Neural Development Neurite outgrowth Golgi outpost Postsynaptic density Enlargeosome Y27632 SNARE |
| title | Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal development |
| title_full | Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal development |
| title_fullStr | Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal development |
| title_full_unstemmed | Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal development |
| title_short | Primary neurons lacking the SNAREs vti1a and vti1b show altered neuronal development |
| title_sort | primary neurons lacking the snares vti1a and vti1b show altered neuronal development |
| topic | Neurite outgrowth Golgi outpost Postsynaptic density Enlargeosome Y27632 SNARE |
| url | https://doi.org/10.1186/s13064-022-00168-2 |
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