eprintid: 10061208 rev_number: 29 eprint_status: archive userid: 608 dir: disk0/10/06/12/08 datestamp: 2018-11-09 18:01:18 lastmod: 2021-10-23 22:49:11 status_changed: 2019-02-01 17:25:02 type: article metadata_visibility: show creators_name: Nazir, FH creators_name: Becker, B creators_name: Brinkmalm, A creators_name: Höglund, K creators_name: Sandelius, Å creators_name: Bergström, P creators_name: Satir, TM creators_name: Öhrfelt, A creators_name: Blennow, K creators_name: Agholme, L creators_name: Zetterberg, H title: Expression and secretion of synaptic proteins during stem cell differentiation to cortical neurons ispublished: pub divisions: UCL divisions: B02 divisions: C07 divisions: D07 divisions: F86 keywords: Development, GAP-43, Neurogranin, SNAP-25, Stem cells, Synaptotagmin-1 note: This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. abstract: Synaptic function and neurotransmitter release are regulated by specific proteins. Cortical neuronal differentiation of human induced pluripotent stem cells (hiPSC) provides an experimental model to obtain more information about synaptic development and physiology in vitro. In this study, expression and secretion of the synaptic proteins, neurogranin (NRGN), growth-associated protein-43 (GAP-43), synaptosomal-associated protein-25 (SNAP-25) and synaptotagmin-1 (SYT-1) were analyzed during cortical neuronal differentiation. Protein levels were measured in cells, modeling fetal cortical development, and cell-conditioned media which was used as a model of cerebrospinal fluid (CSF), respectively. Human iPSC-derived cortical neurons were maintained over a period of at least 150 days, which encompasses the different stages of neuronal development. The differentiation was divided into the following stages: hiPSC, neuro-progenitors, immature and mature cortical neurons. We show that NRGN was first expressed and secreted by neuro-progenitors while the maximum was reached in mature cortical neurons. GAP-43 was expressed and secreted first by neuro-progenitors and its expression increased markedly in immature cortical neurons. SYT-1 was expressed and secreted already by hiPSC but its expression and secretion peaked in mature neurons. SNAP-25 was first detected in neuro-progenitors and the expression and secretion increased gradually during neuronal stages reaching a maximum in mature neurons. The sensitive analytical techniques used to monitor the secretion of these synaptic proteins during cortical development make these data unique, since the secretion of these synaptic proteins has not been investigated before in such experimental models. The secretory profile of synaptic proteins, together with low release of intracellular content, implies that mature neurons actively secrete these synaptic proteins that previously have been associated with neurodegenerative disorders, including Alzheimer's disease. These data support further studies of human neuronal and synaptic development in vitro, and would potentially shed light on the mechanisms underlying altered concentrations of the proteins in bio-fluids in neurodegenerative diseases. date: 2018-12 date_type: published official_url: https://doi.org/10.1016/j.neuint.2018.10.014 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1598928 doi: 10.1016/j.neuint.2018.10.014 pii: S0197-0186(18)30308-5 lyricists_name: Zetterberg, Henrik lyricists_id: HZETT94 actors_name: Jayawardana, Anusha actors_id: AJAYA51 actors_role: owner full_text_status: public publication: Neurochemistry International volume: 121 pagerange: 38-49 event_location: England issn: 1872-9754 citation: Nazir, FH; Becker, B; Brinkmalm, A; Höglund, K; Sandelius, Å; Bergström, P; Satir, TM; ... Zetterberg, H; + view all <#> Nazir, FH; Becker, B; Brinkmalm, A; Höglund, K; Sandelius, Å; Bergström, P; Satir, TM; Öhrfelt, A; Blennow, K; Agholme, L; Zetterberg, H; - view fewer <#> (2018) Expression and secretion of synaptic proteins during stem cell differentiation to cortical neurons. Neurochemistry International , 121 pp. 38-49. 10.1016/j.neuint.2018.10.014 <https://doi.org/10.1016/j.neuint.2018.10.014>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10061208/3/1-s2.0-S0197018618303085-main.pdf