TY - JOUR
T1 - Unique properties of PTEN-L contribute to neuroprotection in response to ischemic-like stress
AU - Jochner, Magdalena C.E.
AU - An, Junfeng
AU - Lättig-Tünnemann, Gisela
AU - Kirchner, Marieluise
AU - Dagane, Alina
AU - Dittmar, Gunnar
AU - Dirnagl, Ulrich
AU - Eickholt, Britta J.
AU - Harms, Christoph
N1 - Funding Information:
We thank Hiroshi Kawabe for iCre:IRES-EGFP expressing plasmid in FUGW. We are grateful for the technical support by Jan Schmoranzer heading the Advanced Medical BioImaging Core Facility at Charité-University Medicine Berlin. M.C.E.J. was funded by a PhD fellowship of the NeuroCure Cluster of Excellence through grants received from the German Research Foundation (DFG). Conditional PTEN knockout mice were funded through the collaborative research center SFB958 to B.J.E. supported by the DFG. U.D. & C.H. received funding by the Federal Ministry of Education and Research (BMBF) for the Center for Stroke Research Berlin and the project ‘SUMO and stroke’. U.D. & C.H. received funding by the Berlin Institute of Health (BIH). We acknowledge support from the German Research Foundation (DFG) and the Open Access Publication Fund of Charité – Universitätsmedizin Berlin.
Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Phosphatase and tensin homolog (PTEN) signalling might influence neuronal survival after brain ischemia. However, the influence of the less studied longer variant termed PTEN-L (or PTENα) has not been studied to date. Therefore, we examined the translational variant PTEN-L in the context of neuronal survival. We identified PTEN-L by proteomics in murine neuronal cultures and brain lysates and established a novel model to analyse PTEN or PTEN-L variants independently in vitro while avoiding overexpression. We found that PTEN-L, unlike PTEN, localises predominantly in the cytosol and translocates to the nucleus 10–20 minutes after glutamate stress. Genomic ablation of PTEN and PTEN-L increased neuronal susceptibility to oxygen-glucose deprivation. This effect was rescued by expression of either PTEN-L indicating that both PTEN isoforms might contribute to a neuroprotective response. However, in direct comparison, PTEN-L replaced neurons were protected against ischemic-like stress compared to neurons expressing PTEN. Neurons expressing strictly nuclear PTEN-L NLS showed increased vulnerability, indicating that nuclear PTEN-L alone is not sufficient in protecting against stress. We identified mutually exclusive binding partners of PTEN-L or PTEN in cytosolic or nuclear fractions, which were regulated after ischemic-like stress. GRB2-associated-binding protein 2, which is known to interact with phosphoinositol-3-kinase, was enriched specifically with PTEN-L in the cytosol in proximity to the plasma membrane and their interaction was lost after glutamate exposure. The present study revealed that PTEN and PTEN-L have distinct functions in response to stress and might be involved in different mechanisms of neuroprotection.
AB - Phosphatase and tensin homolog (PTEN) signalling might influence neuronal survival after brain ischemia. However, the influence of the less studied longer variant termed PTEN-L (or PTENα) has not been studied to date. Therefore, we examined the translational variant PTEN-L in the context of neuronal survival. We identified PTEN-L by proteomics in murine neuronal cultures and brain lysates and established a novel model to analyse PTEN or PTEN-L variants independently in vitro while avoiding overexpression. We found that PTEN-L, unlike PTEN, localises predominantly in the cytosol and translocates to the nucleus 10–20 minutes after glutamate stress. Genomic ablation of PTEN and PTEN-L increased neuronal susceptibility to oxygen-glucose deprivation. This effect was rescued by expression of either PTEN-L indicating that both PTEN isoforms might contribute to a neuroprotective response. However, in direct comparison, PTEN-L replaced neurons were protected against ischemic-like stress compared to neurons expressing PTEN. Neurons expressing strictly nuclear PTEN-L NLS showed increased vulnerability, indicating that nuclear PTEN-L alone is not sufficient in protecting against stress. We identified mutually exclusive binding partners of PTEN-L or PTEN in cytosolic or nuclear fractions, which were regulated after ischemic-like stress. GRB2-associated-binding protein 2, which is known to interact with phosphoinositol-3-kinase, was enriched specifically with PTEN-L in the cytosol in proximity to the plasma membrane and their interaction was lost after glutamate exposure. The present study revealed that PTEN and PTEN-L have distinct functions in response to stress and might be involved in different mechanisms of neuroprotection.
UR - http://www.scopus.com/inward/record.url?scp=85062304316&partnerID=8YFLogxK
U2 - 10.1038/s41598-019-39438-1
DO - 10.1038/s41598-019-39438-1
M3 - Article
C2 - 30816308
AN - SCOPUS:85062304316
SN - 2045-2322
VL - 9
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 3183
ER -