N-methyI-D-aspartate receptors （NMDARs） containing different GluN2 subunits play distinct roles in synaptic plasticity. Such differences may not only be determined by the channel properties, but also by differential...N-methyI-D-aspartate receptors （NMDARs） containing different GluN2 subunits play distinct roles in synaptic plasticity. Such differences may not only be determined by the channel properties, but also by differential surface distribution and synaptic localization. In the present study, using a Cy3-conjugated Fab fragment of the GFP antibody to label surface-located GluN2 subunits tagged with GFP at the N-terminus, we observed the membrane distribution patterns of GluN2A- or GluN2B-containing NMDARs in cultured rat hippocampal neurons. We found that surface NMDARs containing GluN2A, but not those containing GluN2B, were inclined to cluster at DIV7. Swapping the carboxyl termini of the GluN2 subunits completely reversed these distribution patterns. In addition, surface NMDARs containing GluN2A were preferentially associated with PSD-95. Taken together, the results of our study suggest that the clustering distribution of GluN2A- containing NMDARs is determined by the GluN2A C-terminus, and its interaction with PSD-95 plays an important role in this process.展开更多
Paired associative stimulation has been used in stroke patients as an innovative recovery treatment.However,the mechanisms underlying the therapeutic effectiveness of paired associative stimulation on neurological fun...Paired associative stimulation has been used in stroke patients as an innovative recovery treatment.However,the mechanisms underlying the therapeutic effectiveness of paired associative stimulation on neurological function remain unclear.In this study,rats were randomly divided into middle cerebral occlusion model(MCAO)and paired associated magnetic stimulation(PAMS)groups.The MCAO rat model was produced by middle cerebral artery embolization.The PAMS group received PAMS on days 3 to 20 post MCAO.The MCAO group received sham stimulation,three times every week.Within 18 days after ischemia,rats were subjected to behavioral experiments—the foot-fault test,the balance beam walking test,and the ladder walking test.Balance ability was improved on days 15 and 17,and the footfault rate was less in their affected limb on day 15 in the PAMS group compared with the MCAO group.Western blot assay showed that the expression levels of brain derived neurotrophic factor,glutamate receptor 2/3,postsynaptic density protein 95 and synapsin-1 were significantly increased in the PAMS group compared with the MCAO group in the ipsilateral sensorimotor cortex on day 21.Resting-state functional magnetic resonance imaging revealed that regional brain activities in the sensorimotor cortex were increased in the ipsilateral hemisphere,but decreased in the contralateral hemisphere on day 20.By finite element simulation,the electric field distribution showed a higher intensity,of approximately 0.4 A/m^2,in the ischemic cortex compared with the contralateral cortex in the template.Together,our findings show that PAMS upregulates neuroplasticity-related proteins,increases regional brain activity,and promotes functional recovery in the affected sensorimotor cortex in the rat MCAO model.The experiments were approved by the Institutional Animal Care and Use Committee of Fudan University,China(approval No.201802173 S)on March 3,2018.展开更多
Accumulating evidence indicates that the synaptic activation of N-methyl-o-aspartate receptors （NMDARs） has a neuroprotective effect on neurons. Our previous study demonstrated that APPL1 （adaptor protein containin...Accumulating evidence indicates that the synaptic activation of N-methyl-o-aspartate receptors （NMDARs） has a neuroprotective effect on neurons. Our previous study demonstrated that APPL1 （adaptor protein containing pleckstrin homology domain, phosphotyrosine- binding domain, and leucine zipper motif） mediates the synaptic activity-dependent activation of PI3K-Akt signaling via coupling this pathway with NMDAR-PSD95 （postsynaptic density protein 95） complexes. However, the molecular mechanism underlying this process is still unknown. In the present study, we investigated the inter- action of APPL1 with PSD95 using co-immunocyto- chemical staining and western blotting. We found that the PDZ2 domain of PSD95 is a binding partner of APPL1. Furthermore, we identified serine 707 of APPL1, a pre- dicted phosphorylation site within the PDZ-binding motif at the C-terminus, as critical for the binding of APPL1 to PSD95, as well as for activation of the Akt signaling pathway during synaptic activity. This suggests that serine 707 of APPL1 is a potential phosphorylation site and may be involved in regulating the neuroprotective Akt signaling pathway that depends on synaptic NMDAR activity.展开更多
基金supported by grants from the National Basic Research Program of China (2010CB912002)the National Natural Science Foundation of China (81221003 and 81271453)Fundamental Research Funds for the Central Universities of China
文摘N-methyI-D-aspartate receptors （NMDARs） containing different GluN2 subunits play distinct roles in synaptic plasticity. Such differences may not only be determined by the channel properties, but also by differential surface distribution and synaptic localization. In the present study, using a Cy3-conjugated Fab fragment of the GFP antibody to label surface-located GluN2 subunits tagged with GFP at the N-terminus, we observed the membrane distribution patterns of GluN2A- or GluN2B-containing NMDARs in cultured rat hippocampal neurons. We found that surface NMDARs containing GluN2A, but not those containing GluN2B, were inclined to cluster at DIV7. Swapping the carboxyl termini of the GluN2 subunits completely reversed these distribution patterns. In addition, surface NMDARs containing GluN2A were preferentially associated with PSD-95. Taken together, the results of our study suggest that the clustering distribution of GluN2A- containing NMDARs is determined by the GluN2A C-terminus, and its interaction with PSD-95 plays an important role in this process.
基金supported by the National Natural Science Foundation of China,Nos.81974358,81772453(to DSX)。
文摘Paired associative stimulation has been used in stroke patients as an innovative recovery treatment.However,the mechanisms underlying the therapeutic effectiveness of paired associative stimulation on neurological function remain unclear.In this study,rats were randomly divided into middle cerebral occlusion model(MCAO)and paired associated magnetic stimulation(PAMS)groups.The MCAO rat model was produced by middle cerebral artery embolization.The PAMS group received PAMS on days 3 to 20 post MCAO.The MCAO group received sham stimulation,three times every week.Within 18 days after ischemia,rats were subjected to behavioral experiments—the foot-fault test,the balance beam walking test,and the ladder walking test.Balance ability was improved on days 15 and 17,and the footfault rate was less in their affected limb on day 15 in the PAMS group compared with the MCAO group.Western blot assay showed that the expression levels of brain derived neurotrophic factor,glutamate receptor 2/3,postsynaptic density protein 95 and synapsin-1 were significantly increased in the PAMS group compared with the MCAO group in the ipsilateral sensorimotor cortex on day 21.Resting-state functional magnetic resonance imaging revealed that regional brain activities in the sensorimotor cortex were increased in the ipsilateral hemisphere,but decreased in the contralateral hemisphere on day 20.By finite element simulation,the electric field distribution showed a higher intensity,of approximately 0.4 A/m^2,in the ischemic cortex compared with the contralateral cortex in the template.Together,our findings show that PAMS upregulates neuroplasticity-related proteins,increases regional brain activity,and promotes functional recovery in the affected sensorimotor cortex in the rat MCAO model.The experiments were approved by the Institutional Animal Care and Use Committee of Fudan University,China(approval No.201802173 S)on March 3,2018.
基金supported by grants from the National Natural Science Foundation of China(91232303,81221003,and 81561168)
文摘Accumulating evidence indicates that the synaptic activation of N-methyl-o-aspartate receptors （NMDARs） has a neuroprotective effect on neurons. Our previous study demonstrated that APPL1 （adaptor protein containing pleckstrin homology domain, phosphotyrosine- binding domain, and leucine zipper motif） mediates the synaptic activity-dependent activation of PI3K-Akt signaling via coupling this pathway with NMDAR-PSD95 （postsynaptic density protein 95） complexes. However, the molecular mechanism underlying this process is still unknown. In the present study, we investigated the inter- action of APPL1 with PSD95 using co-immunocyto- chemical staining and western blotting. We found that the PDZ2 domain of PSD95 is a binding partner of APPL1. Furthermore, we identified serine 707 of APPL1, a pre- dicted phosphorylation site within the PDZ-binding motif at the C-terminus, as critical for the binding of APPL1 to PSD95, as well as for activation of the Akt signaling pathway during synaptic activity. This suggests that serine 707 of APPL1 is a potential phosphorylation site and may be involved in regulating the neuroprotective Akt signaling pathway that depends on synaptic NMDAR activity.
