Leucine-rich repeats containing 4(LRRC4,also named netrin-G ligand 2[NGL-2])is a member of the NetrinGs ligands(NGLs)family.As a gene with relatively high and specific expression in brain,it is a member of the leucine...Leucine-rich repeats containing 4(LRRC4,also named netrin-G ligand 2[NGL-2])is a member of the NetrinGs ligands(NGLs)family.As a gene with relatively high and specific expression in brain,it is a member of the leucine-rich repeat superfamily and has been proven to be a suppressor gene for gliomas,thus being involved in gliomagenesis.LRRC4 is the core of microRNA-dependent multi-phase regulatory loops that inhibit the proliferation and invasion of glioblastoma(GB)cells,including LRRC4/NGL2-activator protein 2(AP2)-microRNA(miR)182-LRRC4 and LRRC4-miR185-DNA methyltransferase 1(DNMT1)-LRRC4/specific protein 1(SP1)-DNMT1-LRRC4.In this review,we demonstrated LRRC4 as a new member of the partitioning-defective protein(PAR)polarity complex that promotes axon differentiation,mediates the formation and plasticity of synapses,and assists information input to the hippocampus and storage of memory.As an important synapse regulator,aberrant expression of LRRC4 has been detected in autism,spinal injury and GBs.LRRC4 is a candidate susceptibility gene for autism and a neuro-protective factor in spinal nerve damage.In GBs,LRRC4 is a novel inhibitor of autophagy,and an inhibitor of protein–protein interactions involving in temozolomide resistance,tumor immune microenvironment,and formation of circular RNA.展开更多
Down syndrome cell adhesion molecule(DSCAM)acts as a netrin-1 receptor and mediates attractive response of axons to netrin-1 in neural development.However,the signaling mechanisms of netrin-DSCAM remain unclear.Here w...Down syndrome cell adhesion molecule(DSCAM)acts as a netrin-1 receptor and mediates attractive response of axons to netrin-1 in neural development.However,the signaling mechanisms of netrin-DSCAM remain unclear.Here we report that AMP-activated protein kinase(AMPK)interacts with DSCAM through itsγsubunit,but does not interact with DCC(deleted in co-lorectal cancer),another major receptor for netrin-1.Netrin-treatment of cultured cortical neurons leads to increased phosphorylation of AMPK.Both AMPK mu-tant with dominant-negative effect and AMPK inhibitor can significantly suppress netrin-1 induced neurite outgrowth.Together,these findings demonstrate that AMPK interacts with DSCAM and plays an important role in netrin-1 induced neurite outgrowth.Our study uncovers a previously unknown component,AMPK,in netrin-DSCAM signaling pathway.展开更多
The peripheral nervous system has an astonishing ability to regenerate following a compression or crush injury;however,the potential for full repair following a transection injury is much less.Currently,the major clin...The peripheral nervous system has an astonishing ability to regenerate following a compression or crush injury;however,the potential for full repair following a transection injury is much less.Currently,the major clinical challenge for peripheral nerve repair come from long gaps between the proximal and distal nerve stumps,which prevent regenerating axons reaching the distal nerve.Precise axon targeting during nervous system development is controlled by families of axon guidance molecules including Netrins,Slits,Ephrins and Semaphorins.Several recent studies have indicated key roles of Netrin1,Slit3 and EphrinB2 signalling in controlling the formation of new nerve bridge tissue and precise axon regeneration after peripheral nerve transection injury.Inside the nerve bridge,nerve fibroblasts express EphrinB2 while migrating Schwann cells express the receptor EphB2.EphrinB2/EphB2 signalling between nerve fibroblasts and migrating Schwann cells is required for Sox2 upregulation in Schwann cells and the formation of Schwann cell cords within the nerve bridge to allow directional axon growth to the distal nerve stump.Macrophages in the outermost layer of the nerve bridge express Slit3 while migrating Schwann cells and regenerating axons express the receptor Robo1;within Schwann cells,Robo1 expression is also Sox2-dependent.Slit3/Robo1 signalling is required to keep migrating Schwann cells and regenerating axons inside the nerve bridge.In addition to the Slit3/Robo1 signalling system,migrating Schwann cells also express Netrin1 and regenerating axons express the DCC receptor.It appears that migrating Schwann cells could also use Netrin1 as a guidance cue to direct regenerating axons across the peripheral nerve gap.Engineered neural tissues have been suggested as promising alternatives for the repair of large peripheral nerve gaps.Therefore,understanding the function of classic axon guidance molecules in nerve bridge formation and their roles in axon regeneration could be highly beneficial in developing engineered neural展开更多
Houshiheisan,a classic prescription in traditional Chinese medicine,contains Flos Chrysanthemi,Radix Saposhnikoviae,Ramulus Cinnamomi,Rhizoma Chuanxiong,Radix et Rhizoma Asari,Radix Platycodonis,Rhizoma Atractylodis m...Houshiheisan,a classic prescription in traditional Chinese medicine,contains Flos Chrysanthemi,Radix Saposhnikoviae,Ramulus Cinnamomi,Rhizoma Chuanxiong,Radix et Rhizoma Asari,Radix Platycodonis,Rhizoma Atractylodis macrocephalae,Poria,Rhizoma Zingiberis,Radix Angelicae sinensis,Radix et Rhizoma Ginseng,Radix Scutellariae and Concha Ostreae.According to traditional Chinese medicine theory,Flos Chrysanthemi,Radix Saposhnikoviae,Ramulus Cinnamomi,Rhizoma Chuanxiong,Radix et Rhizoma Asari and Radix Platycodonis are wind-dispelling drugs;Rhizoma Atractylodis macrocephalae,Poria,Rhizoma Zingiberis,Radix Angelicae sinensis and Radix et Rhizoma Ginseng are deficiency-nourishing drugs.A large number of randomized controlled trials have shown that Houshiheisan is effective in treating stroke,but its mechanism of action is unknown.Axonal remodeling is an important mechanism in neural protection and regeneration.Therefore,this study explored the effect and mechanism of action of Houshiheisan on the repair of axons after cerebral ischemia.Rat models of focal cerebral ischemia were established by ligating the right middle cerebral artery.At 6 hours after model establishment,rats were intragastrically administered 10.5 g/kg Houshiheisan or 7.7 g/kg wind-dispelling drug or 2.59 g/kg deficiency-nourishing drug.These medicines were intragastrically administered as above every 24 hours for 7 consecutive days.Houshiheisan,and its wind-dispelling and deficiency-nourishing components reduced the neurological deficit score and ameliorated axon and neuron lesions after cerebral ischemia.Furthermore,Houshiheisan,and its wind-dispelling and deficiency-nourishing components decreased the expression of proteins that inhibit axonal remodeling：amyloid precursor protein,neurite outgrowth inhibitor protein A（Nogo-A）,Rho family small GTPase A（Rho A） and Rho-associated kinase 2（Rock2）,and increased the expression of growth associated protein-43,microtubule-associated protein-2,netrin-1,Ras-related C3 botulinum toxin substrate 1（R展开更多
基金National Natural Science Foundation of China(No.82073096)Hunan Provincial Natural Science Foundation of China(No.2022JJ40578)
文摘Leucine-rich repeats containing 4(LRRC4,also named netrin-G ligand 2[NGL-2])is a member of the NetrinGs ligands(NGLs)family.As a gene with relatively high and specific expression in brain,it is a member of the leucine-rich repeat superfamily and has been proven to be a suppressor gene for gliomas,thus being involved in gliomagenesis.LRRC4 is the core of microRNA-dependent multi-phase regulatory loops that inhibit the proliferation and invasion of glioblastoma(GB)cells,including LRRC4/NGL2-activator protein 2(AP2)-microRNA(miR)182-LRRC4 and LRRC4-miR185-DNA methyltransferase 1(DNMT1)-LRRC4/specific protein 1(SP1)-DNMT1-LRRC4.In this review,we demonstrated LRRC4 as a new member of the partitioning-defective protein(PAR)polarity complex that promotes axon differentiation,mediates the formation and plasticity of synapses,and assists information input to the hippocampus and storage of memory.As an important synapse regulator,aberrant expression of LRRC4 has been detected in autism,spinal injury and GBs.LRRC4 is a candidate susceptibility gene for autism and a neuro-protective factor in spinal nerve damage.In GBs,LRRC4 is a novel inhibitor of autophagy,and an inhibitor of protein–protein interactions involving in temozolomide resistance,tumor immune microenvironment,and formation of circular RNA.
基金supported by the National Basic Research Program(973 Program)(Nos.2010CB529603 and 2009CB825402)the National Natural Science Foundation of China(91132710)and Chinese Academy of Science(CASNN-GWPPS-2008)supported by NIH(RO1AG033004 and R56NS074763)and ALS Therapy Alliance.
文摘Down syndrome cell adhesion molecule(DSCAM)acts as a netrin-1 receptor and mediates attractive response of axons to netrin-1 in neural development.However,the signaling mechanisms of netrin-DSCAM remain unclear.Here we report that AMP-activated protein kinase(AMPK)interacts with DSCAM through itsγsubunit,but does not interact with DCC(deleted in co-lorectal cancer),another major receptor for netrin-1.Netrin-treatment of cultured cortical neurons leads to increased phosphorylation of AMPK.Both AMPK mu-tant with dominant-negative effect and AMPK inhibitor can significantly suppress netrin-1 induced neurite outgrowth.Together,these findings demonstrate that AMPK interacts with DSCAM and plays an important role in netrin-1 induced neurite outgrowth.Our study uncovers a previously unknown component,AMPK,in netrin-DSCAM signaling pathway.
文摘The peripheral nervous system has an astonishing ability to regenerate following a compression or crush injury;however,the potential for full repair following a transection injury is much less.Currently,the major clinical challenge for peripheral nerve repair come from long gaps between the proximal and distal nerve stumps,which prevent regenerating axons reaching the distal nerve.Precise axon targeting during nervous system development is controlled by families of axon guidance molecules including Netrins,Slits,Ephrins and Semaphorins.Several recent studies have indicated key roles of Netrin1,Slit3 and EphrinB2 signalling in controlling the formation of new nerve bridge tissue and precise axon regeneration after peripheral nerve transection injury.Inside the nerve bridge,nerve fibroblasts express EphrinB2 while migrating Schwann cells express the receptor EphB2.EphrinB2/EphB2 signalling between nerve fibroblasts and migrating Schwann cells is required for Sox2 upregulation in Schwann cells and the formation of Schwann cell cords within the nerve bridge to allow directional axon growth to the distal nerve stump.Macrophages in the outermost layer of the nerve bridge express Slit3 while migrating Schwann cells and regenerating axons express the receptor Robo1;within Schwann cells,Robo1 expression is also Sox2-dependent.Slit3/Robo1 signalling is required to keep migrating Schwann cells and regenerating axons inside the nerve bridge.In addition to the Slit3/Robo1 signalling system,migrating Schwann cells also express Netrin1 and regenerating axons express the DCC receptor.It appears that migrating Schwann cells could also use Netrin1 as a guidance cue to direct regenerating axons across the peripheral nerve gap.Engineered neural tissues have been suggested as promising alternatives for the repair of large peripheral nerve gaps.Therefore,understanding the function of classic axon guidance molecules in nerve bridge formation and their roles in axon regeneration could be highly beneficial in developing engineered neural
基金supported by the National Natural Science Foundation of China,No.81373526
文摘Houshiheisan,a classic prescription in traditional Chinese medicine,contains Flos Chrysanthemi,Radix Saposhnikoviae,Ramulus Cinnamomi,Rhizoma Chuanxiong,Radix et Rhizoma Asari,Radix Platycodonis,Rhizoma Atractylodis macrocephalae,Poria,Rhizoma Zingiberis,Radix Angelicae sinensis,Radix et Rhizoma Ginseng,Radix Scutellariae and Concha Ostreae.According to traditional Chinese medicine theory,Flos Chrysanthemi,Radix Saposhnikoviae,Ramulus Cinnamomi,Rhizoma Chuanxiong,Radix et Rhizoma Asari and Radix Platycodonis are wind-dispelling drugs;Rhizoma Atractylodis macrocephalae,Poria,Rhizoma Zingiberis,Radix Angelicae sinensis and Radix et Rhizoma Ginseng are deficiency-nourishing drugs.A large number of randomized controlled trials have shown that Houshiheisan is effective in treating stroke,but its mechanism of action is unknown.Axonal remodeling is an important mechanism in neural protection and regeneration.Therefore,this study explored the effect and mechanism of action of Houshiheisan on the repair of axons after cerebral ischemia.Rat models of focal cerebral ischemia were established by ligating the right middle cerebral artery.At 6 hours after model establishment,rats were intragastrically administered 10.5 g/kg Houshiheisan or 7.7 g/kg wind-dispelling drug or 2.59 g/kg deficiency-nourishing drug.These medicines were intragastrically administered as above every 24 hours for 7 consecutive days.Houshiheisan,and its wind-dispelling and deficiency-nourishing components reduced the neurological deficit score and ameliorated axon and neuron lesions after cerebral ischemia.Furthermore,Houshiheisan,and its wind-dispelling and deficiency-nourishing components decreased the expression of proteins that inhibit axonal remodeling：amyloid precursor protein,neurite outgrowth inhibitor protein A（Nogo-A）,Rho family small GTPase A（Rho A） and Rho-associated kinase 2（Rock2）,and increased the expression of growth associated protein-43,microtubule-associated protein-2,netrin-1,Ras-related C3 botulinum toxin substrate 1（R
