Recent studies have shown that mutation at Ser522 causes inhibition of collapsin response mediator protein 2(CRMP2) phosphorylation and induces axon elongation and partial recovery of the lost sensorimotor function af...Recent studies have shown that mutation at Ser522 causes inhibition of collapsin response mediator protein 2(CRMP2) phosphorylation and induces axon elongation and partial recovery of the lost sensorimotor function after spinal cord injury(SCI).We aimed to reveal the intracellular mechanism in axotomized neurons in the CRMP2 knock-in(CRMP2KI) mouse model by performing transcriptome analysis in mouse sensorimotor cortex using micro-dissection punching system.Prior to that, we analyzed the structural pathophysiology in axotomized or neighboring neurons after SCI and found that somatic atrophy and dendritic spine reduction in sensorimotor cortex were suppressed in CRMP2KI mice.Further analysis of the transcriptome has aided in the identification of four hemoglobin genes Hba-a1, Hba-a2, Hbb-bs, and Hbb-bt that are significantly upregulated in wild-type mice with concomitant upregulation of genes involved in the oxidative phosphorylation and ribosomal pathways after SCI.However, we observed substantial upregulation in channel activity genes and downregulation of genes regulating vesicles, synaptic function, glial cell differentiation in CRMP2KI mice.Moreover, the transcriptome profile of CRMP2KI mice has been discussed wherein energy metabolism and neuronal pathways were found to be differentially regulated.Our results showed that CRMP2KI mice displayed improved SCI pathophysiology not only via microtubule stabilization in neurons, but also possibly via the whole metabolic system in the central nervous system, response changes in glial cells, and synapses.Taken together, we reveal new insights on SCI pathophysiology and the regenerative mechanism of central nervous system by the inhibition of CRMP2 phosphorylation at Ser522.All these experiments were performed in accordance with the guidelines of the Institutional Animal Care and Use Committee at Waseda University, Japan(2017-A027 approved on March 21, 2017;2018-A003 approved on March 25, 2018;2019-A026 approved on March 25, 2019).展开更多
CRMP2 is one of the well-studied members of the CRMPs family,which has been demonstrated not only play the roles in neurite extension,dendrites and dendritic spine development,but also in the AMPA receptor trafficking...CRMP2 is one of the well-studied members of the CRMPs family,which has been demonstrated not only play the roles in neurite extension,dendrites and dendritic spine development,but also in the AMPA receptor trafficking.However,the role of CRMP2 on the trafficking of AMPA receptor GluA2 subunit especially phosphorylated GluA2 is unknown.GST-Pull down and C-IP assays,immunofluorescence staining and whole cell patch clamp recording technique were performed in this study.The results showed that CRMP2 interacted with wild-type GluA2 and promoted the surface expression of wild-type GluA2.No matter GluA2 S880 was exogenously phosphorylated by phorbol myristate acetate(TPA)or endogenously phosphorylated by PKC5,CRMP2 can promote the surface expression of phosphorylated GluA2 and enhance its amplitude and frequency of mEPSCs,increasing the slope of the I-V curve.展开更多
Brain-specific loss of a microtubule-binding protein collapsin response mediator protein-2(CRMP2)in the mouse recapitulates many schizophrenia-like behaviors of human patients,possibly resulting from associated develo...Brain-specific loss of a microtubule-binding protein collapsin response mediator protein-2(CRMP2)in the mouse recapitulates many schizophrenia-like behaviors of human patients,possibly resulting from associated developmental deficits in neuronal differentiation,path-finding,and synapse formation.However,it is still unclear how the Crmp2 loss affects neuronal circuit function and plasticity.By conducting in vivo and ex vivo electrophysiological recording in the mouse primary visual cortex(V1),we reveal that CRMP2 exerts a key regulation on the timing of postnatal critical period(CP)for experience-dependent circuit plasticity of sensory cortex.In the developing V1,the Crmp2 deficiency induces not only a delayed maturation of visual tuning functions but also a precocious CP for visual input-induced ocular dominance plasticity and its induction activity–coincident binocular inputs right after eye-opening.Mechanistically,the Crmp2 deficiency accelerates the maturation process of cortical inhibitory transmission and subsequently promotes an early emergence of balanced excitatory-inhibitory cortical circuits during the postnatal development.Moreover,the precocious CP plasticity results in deteriorated binocular depth perception in adulthood.Thus,these findings suggest that the Crmp2 deficiency dysregulates the timing of CP for experience-dependent refinement of circuit connections and further leads to impaired sensory perception in later life.展开更多
Axonal degeneration is a key pathological feature in many neurological diseases. It often leads to persistent deficits due to the inability of axons to regenerate in the central nervous system. Therefore therapeutic a...Axonal degeneration is a key pathological feature in many neurological diseases. It often leads to persistent deficits due to the inability of axons to regenerate in the central nervous system. Therefore therapeutic approaches should optimally both attenuate axonal degeneration and foster axonal regeneration. Compelling evidence suggests that collapsin response mediator protein-2（CRMP2） might be a molecular target fulfilling these requirements. In this mini-review, we give a compact overview of the known functions of CRMP2 and its molecular interactors in neurite outgrowth and in neurodegenerative conditions. Moreover, we discuss in detail our recent findings on the role of CRMP2 in acute axonal degeneration in the optic nerve. We found that the calcium influx induced by the lesion activates the protease calpain which cleaves CRMP2, leading to impairment of axonal transport. Both calpain inhibition and CRMP2 overexpression effectively protected the proximal axons against acute axonal degeneration. Taken together, CRMP2 is further characterized as a central molecular player in acute axonal degeneration and thus evolves as a promising therapeutic target to both counteract axonal degeneration and foster axonal regeneration in neurodegenerative and neurotraumatic diseases.展开更多
基金supported by Grants-in-Aid for Scientific Research on Priority Areas from The Ministry of Education, Culture, Sports, Science and Technology(No.26430043to TO)。
文摘Recent studies have shown that mutation at Ser522 causes inhibition of collapsin response mediator protein 2(CRMP2) phosphorylation and induces axon elongation and partial recovery of the lost sensorimotor function after spinal cord injury(SCI).We aimed to reveal the intracellular mechanism in axotomized neurons in the CRMP2 knock-in(CRMP2KI) mouse model by performing transcriptome analysis in mouse sensorimotor cortex using micro-dissection punching system.Prior to that, we analyzed the structural pathophysiology in axotomized or neighboring neurons after SCI and found that somatic atrophy and dendritic spine reduction in sensorimotor cortex were suppressed in CRMP2KI mice.Further analysis of the transcriptome has aided in the identification of four hemoglobin genes Hba-a1, Hba-a2, Hbb-bs, and Hbb-bt that are significantly upregulated in wild-type mice with concomitant upregulation of genes involved in the oxidative phosphorylation and ribosomal pathways after SCI.However, we observed substantial upregulation in channel activity genes and downregulation of genes regulating vesicles, synaptic function, glial cell differentiation in CRMP2KI mice.Moreover, the transcriptome profile of CRMP2KI mice has been discussed wherein energy metabolism and neuronal pathways were found to be differentially regulated.Our results showed that CRMP2KI mice displayed improved SCI pathophysiology not only via microtubule stabilization in neurons, but also possibly via the whole metabolic system in the central nervous system, response changes in glial cells, and synapses.Taken together, we reveal new insights on SCI pathophysiology and the regenerative mechanism of central nervous system by the inhibition of CRMP2 phosphorylation at Ser522.All these experiments were performed in accordance with the guidelines of the Institutional Animal Care and Use Committee at Waseda University, Japan(2017-A027 approved on March 21, 2017;2018-A003 approved on March 25, 2018;2019-A026 approved on March 25, 2019).
文摘CRMP2 is one of the well-studied members of the CRMPs family,which has been demonstrated not only play the roles in neurite extension,dendrites and dendritic spine development,but also in the AMPA receptor trafficking.However,the role of CRMP2 on the trafficking of AMPA receptor GluA2 subunit especially phosphorylated GluA2 is unknown.GST-Pull down and C-IP assays,immunofluorescence staining and whole cell patch clamp recording technique were performed in this study.The results showed that CRMP2 interacted with wild-type GluA2 and promoted the surface expression of wild-type GluA2.No matter GluA2 S880 was exogenously phosphorylated by phorbol myristate acetate(TPA)or endogenously phosphorylated by PKC5,CRMP2 can promote the surface expression of phosphorylated GluA2 and enhance its amplitude and frequency of mEPSCs,increasing the slope of the I-V curve.
基金the National Natural Science Foundation of China(32071025,31921002,and 31730108)the Beijing Municipal Science&Technology Commission(Z181100001518001)+1 种基金the Interdisciplinary Research Fund of Beijing Normal Universitythe Strategic Priority Research Program and Innovation Program of the Chinese Academy of Sciences(XDB32020100)。
文摘Brain-specific loss of a microtubule-binding protein collapsin response mediator protein-2(CRMP2)in the mouse recapitulates many schizophrenia-like behaviors of human patients,possibly resulting from associated developmental deficits in neuronal differentiation,path-finding,and synapse formation.However,it is still unclear how the Crmp2 loss affects neuronal circuit function and plasticity.By conducting in vivo and ex vivo electrophysiological recording in the mouse primary visual cortex(V1),we reveal that CRMP2 exerts a key regulation on the timing of postnatal critical period(CP)for experience-dependent circuit plasticity of sensory cortex.In the developing V1,the Crmp2 deficiency induces not only a delayed maturation of visual tuning functions but also a precocious CP for visual input-induced ocular dominance plasticity and its induction activity–coincident binocular inputs right after eye-opening.Mechanistically,the Crmp2 deficiency accelerates the maturation process of cortical inhibitory transmission and subsequently promotes an early emergence of balanced excitatory-inhibitory cortical circuits during the postnatal development.Moreover,the precocious CP plasticity results in deteriorated binocular depth perception in adulthood.Thus,these findings suggest that the Crmp2 deficiency dysregulates the timing of CP for experience-dependent refinement of circuit connections and further leads to impaired sensory perception in later life.
文摘Axonal degeneration is a key pathological feature in many neurological diseases. It often leads to persistent deficits due to the inability of axons to regenerate in the central nervous system. Therefore therapeutic approaches should optimally both attenuate axonal degeneration and foster axonal regeneration. Compelling evidence suggests that collapsin response mediator protein-2（CRMP2） might be a molecular target fulfilling these requirements. In this mini-review, we give a compact overview of the known functions of CRMP2 and its molecular interactors in neurite outgrowth and in neurodegenerative conditions. Moreover, we discuss in detail our recent findings on the role of CRMP2 in acute axonal degeneration in the optic nerve. We found that the calcium influx induced by the lesion activates the protease calpain which cleaves CRMP2, leading to impairment of axonal transport. Both calpain inhibition and CRMP2 overexpression effectively protected the proximal axons against acute axonal degeneration. Taken together, CRMP2 is further characterized as a central molecular player in acute axonal degeneration and thus evolves as a promising therapeutic target to both counteract axonal degeneration and foster axonal regeneration in neurodegenerative and neurotraumatic diseases.
