Zinc Deficiency Decreases Neurite Extension via CRMP2 Signal Pathway.

Previous reports indicated that zinc deficiency could increase the risk of infectious diseases and developmental retardation in children. In experimental study, it has been reported that zinc deficiency during the embryonic period inhibited fetal growth, and disturbed neural differentiation and higher brain function later in adulthood. Although it has been suggested that zinc deficiency during development can have significant effects on neuronal differentiation and maturation, the molecular mechanisms of the effects of low zinc on neuronal differentiation during development have not been elucidated in detail. This study was performed to determine the effects of low zinc status on neurite outgrowth and collapsin response mediator protein 2 (CRMP2) signal pathway. Low zinc suppressed neurite outgrowth, and caused increase levels of phosphorylated CRMP2 (pCRMP2) relative to CRMP2, and decrease levels of phosphorylated glycogen synthase kinase 3ß (pGSK3ß) relative to GSK3ß in human neuroblastoma cell line (SH-SY5Y) cells on days 1, 2, and 3 of neuronal differentiation induction. Neurite outgrowth inhibited by low zinc was restored by treatment with the GSK3ß inhibitor CHIR99021. These results suggested that low zinc causes neurite outgrowth inhibition via phosphorylation of CRMP2 by GSK3ß. In conclusion, this study is the first to demonstrate that CRMP signaling is involved in the suppression of neurite outgrowth by low zinc.

pHeeling the pHorce.

In this issue of Neuron, Yamada et al.1 show that fast excitatory neurotransmission by protons acting at acid-sensing ion channels (ASICs) mediates mechanical force-evoked signaling at the Merkel cell-neurite complex, contributing to mammalian tactile discrimination.

Circulating PACAP levels are associated with altered imaging measures of entorhinal cortex neurite density in posttraumatic stress disorder.

Introduction: Pituitary adenylate cyclase-activating polypeptide (PACAP) regulates plasticity in brain systems underlying arousal and memory and is associated with posttraumatic stress disorder (PTSD). Research in animal models suggests that PACAP modulates entorhinal cortex (EC) input to the hippocampus, contributing to impaired contextual fear conditioning. In PTSD, PACAP is associated with higher activity of the amygdala to threat stimuli and lower functional connectivity of the amygdala and hippocampus. However, PACAP-affiliated structural alterations of these regions have not been investigated in PTSD. Here, we examined whether peripheral PACAP levels were associated with neuronal morphology of the amygdala and hippocampus (primary analyses), and EC (secondary) using Neurite Orientation Dispersion and Density Imaging.Methods: Sixty-four (44 female) adults (19 to 54 years old) with DSM-5 Criterion A trauma exposure completed the Clinician-Administered PTSD Scale (CAPS-5), a blood draw, and magnetic resonance imaging. PACAP38 radioimmunoassay was performed and T1-weighted and multi-shell diffusion-weighted images were acquired. Neurite Density Index (NDI) and Orientation Dispersion Index (ODI) were quantified in the amygdala, hippocampus, and EC. CAPS-5 total score and anxious arousal score were used to test for clinical associations with brain structure.Results: Higher PACAP levels were associated with greater EC NDI (ß = 0.0099, q = 0.032) and lower EC ODI (ß = -0.0073, q = 0.047), and not hippocampal or amygdala measures. Neither EC NDI nor ODI was associated with clinical measures.Conclusions: Circulating PACAP levels were associated with altered neuronal density of the EC but not the hippocampus or amygdala. These findings strengthen evidence that PACAP may impact arousal-associated memory circuits in PTSD.

PACAP was associated with altered entorhinal cortex neurite density in PTSD.PACAP was not associated with altered neurite density in amygdala or hippocampus.PACAP may impact arousal-associated memory circuits.

Aberrant microstructural integrity of white matter in mild and severe orthostatic hypotension: A NODDI study.

OBJECTIVE: Scarce evidence is available to elucidate the association between the abnormal microstructure of white matter (WM) and cognitive performance in patients with orthostatic hypotension (OH). This study investigated the microstructural integrity of WM in patients with mild OH (MOH) and severe OH (SOH) and evaluated the association of abnormal WM microstructure with the broad cognitive domains and cognition-related plasma biomarkers. METHODS: Our study included 72 non-OH (NOH), 17 MOH, and 11 SOH participants. Across the groups, the WM integrity was analyzed by neurite orientation dispersion and density imaging (NODDI), and differences in WM microstructure were evaluated by nonparametric tests and post hoc models. The correlations between WM microstructure and broad cognitive domains and cognition-related plasma biomarkers were assessed by Spearman's correlation analysis. RESULTS: The abnormal WM microstructure was localized to the WM fiber bundles in MOH patients but distributed widely in SOH cohorts (p < 0.05). Further analysis showed that the neurite density index of the left cingulate gyrus was negatively associated with amyloid ß-40, glial fibrillary acidic protein, neurofilament light chain, phospho-tau181 (p < 0.05) but positively with global cognitive function (MOCA, MMSE, AER-III), memory, attention, language, language fluency, visuospatial function and amyloid ß-40 / amyloid ß-42 (p < 0.05). Additionally, other abnormal WM microstructures of OH were associated with broad cognitive domains and cognition-related plasma biomarkers to varying degrees. CONCLUSION: The findings evidence that abnormal WM microstructures may present themselves as early as in the MOH phase and that these structural abnormalities are associated with cognitive functions and cognition-related plasma biomarkers.

Modulation of neuronal morphology by antipsychotic drug: Involvement of serotonin receptor 7.

Antipsychotic drugs (APDs) are the primary pharmacological treatment for schizophrenia, a complex disorder characterized by altered neuronal connectivity. Atypical or second-generation antipsychotics, such as Risperidone (RSP) and Clozapine (CZP) predominantly block dopaminergic D2 and serotonin receptor 2A (5-HT2A) neurotransmission. Both compounds also exhibit affinity for the 5-HT7R, with RSP acting as an antagonist and CZP as an inverse agonist. Our study aimed to determine whether RSP and CZP can influence neuronal morphology through a 5-HT7R-mediated mechanism. Here, we demonstrated that CZP promotes neurite outgrowth of early postnatal cortical neurons, and the 5-HT7R mediates its effect. Conversely, RSP leads to a reduction of neurite length of early postnatal cortical neurons, in a 5-HT7R-independent way. Furthermore, we found that the effects of CZP, mediated by 5-HT7R activation, require the participation of ERK and Cdk5 kinase pathways. At the same time, the modulation of neurite length by RSP does not involve these pathways. In conclusion, our findings provide valuable insights into the morphological changes induced by these two APDs in neurons and elucidate some of the associated molecular pathways. Investigating the 5-HT7R-dependent signaling pathways underlying the neuronal morphogenic effects of APDs may contribute to the identification of novel targets for the treatment of schizophrenia.

Preparation of Viable Human Neurites for Neurobiological and Neurodegeneration Studies.

Few models allow the study of neurite damage in the human central nervous system. We used here dopaminergic LUHMES neurons to establish a culture system that allows for (i) the observation of highly enriched neurites, (ii) the preparation of the neurite fraction for biochemical studies, and (iii) the measurement of neurite markers and metabolites after axotomy. LUHMES-based spheroids, plated in culture dishes, extended neurites of several thousand µm length, while all somata remained aggregated. These cultures allowed an easy microscopic observation of live or fixed neurites. Neurite-only cultures (NOC) were produced by cutting out the still-aggregated somata. The potential application of such cultures was exemplified by determinations of their protein and RNA contents. For instance, the mitochondrial TOM20 protein was highly abundant, while nuclear histone H3 was absent. Similarly, mitochondrial-encoded RNAs were found at relatively high levels, while the mRNA for a histone or the neuronal nuclear marker NeuN (RBFOX3) were relatively depleted in NOC. Another potential use of NOC is the study of neurite degeneration. For this purpose, an algorithm to quantify neurite integrity was developed. Using this tool, we found that the addition of nicotinamide drastically reduced neurite degeneration. Also, the chelation of Ca2+ in NOC delayed the degeneration, while inhibitors of calpains had no effect. Thus, NOC proved to be suitable for biochemical analysis and for studying degeneration processes after a defined cut injury.

Localization of truncated TrkB and co-expression with full-length TrkB in the cerebral cortex of adult mice.

Brain-derived neurotrophic factor (BDNF), one of the neurotrophins, and its specific receptor TrkB, are abundantly distributed in the central nervous system (CNS) and have a variety of biological effects, such as neural survival, neurite elongation, neural differentiation, and enhancing synaptic functions. Currently, there are two TrkB subtypes: full-length TrkB (TrkB-FL), which has a tyrosine kinase in the intracellular domain, and TrkB-T1, which is a tyrosine kinase-deficient form. While TrkB-FL is a typical tyrosine kinase receptor, TrkB-T1 is a main form expressed in the CNS of adult mammals, but its function is unknown. In this study, we performed fluorescent staining of the cerebral cortex of adult mice, by using TrkB-T1 antiserum and various antibodies of marker molecules for neurons and glial cells. We found that TrkB-T1 was expressed not only in neurons but also in astrocytes. In contrast, little expression of TrkB-T1 was found in oligodendrocytes and microglia. TrkB-T1 was expressed in almost all of the cells expressing TrkB-FL, indicating the direct interaction between TrkB subtypes. These findings suggest that a part of various functions of BDNF-TrkB signaling might be due to the interaction and cellular localization of TrkB subtypes in the cerebral cortex.

Chemoenzymatic Synthesis of GAA-7 Glycan Analogues and Evaluation of Their Neuritogenic Activities.

Ganglioside GAA-7 exhibits higher neurite outgrowth than ganglioside GM1a and most echinodermatous gangliosides (EGs) when tested on neuron-like rat adrenal pheochromocytoma (PC12) cells in the presence of nerve growth factor (NGF). The unique structure of GAA-7 glycan, containing an uncommon sialic acid (8-O-methyl-N-glycolylneuraminic acid) and sialic acid-α-2,3-GalNAc linkage, makes it challenging to synthesize. We recently developed a streamlined method to chemoenzymatically synthesize GAA-7 glycan and employed this modular strategy to efficiently prepare a library of GAA-7 glycan analogues incorporating N-modified or 8-methoxyl sialic acids. Most of these synthetic glycans exhibited moderate efficacy in promoting neuronal differentiation of PC12 cells. Among them, the analogue containing common sialic acid shows greater potential than the GAA-7 glycan itself. This result reveals that methoxy modification is not essential for neurite outgrowth. Consequently, the readily available analogue presents a promising model for further biological investigations.

The emerging role of ectodermal neural cortex 1 in cancer.

Ectodermal neural cortex 1 (ENC1) is a protein that plays a crucial role in the regulation of various cellular processes such as cell proliferation, differentiation, and apoptosis. Numerous studies have shown that ENC1 is overexpressed in various types of cancers, including breast, lung, pancreatic, and colorectal cancer, and its upregulation is correlated with a poorer prognosis. In addition to its role in cancer growth and spreading, ENC1 has also been linked to neuronal process development and neural crest cell differentiation. In this review, we provide an overview of the current knowledge on the relationship between ENC1 and cancer. We discuss the molecular mechanisms by which ENC1 contributes to tumorigenesis, including its involvement in multiple oncogenic signaling pathways. We also summarize the potential of targeting ENC1 for cancer therapy, as its inhibition has been shown to significantly reduce cancer cell invasion, growth, and metastasis. Finally, we highlight the remaining gaps in our understanding of ENC1's role in cancer and propose potential directions for future research.

Ciliary neurotrophic factor mediated growth of retinal ganglion cell axons on PGS/PCL scaffolds.

Ciliary neurotrophic factor (CNTF) promotes survival and/or differentiation of a variety of neuronal cells including retinal ganglion cells (RGCs). Delivery of CNTF requires a suitable medium capable of mediating diffusion and premature release of CNTF within the target tissue. Polymeric tissue-engineered scaffolds have been readily used as substrates for cell transplantation, expansion, and differentiation and, as carriers of cell growth factors. Their functions to CNTF release for RGC proliferation have remained so far unexplored, especially to CNTF affinity to the scaffold and subsequent RGC fate. Electrospunpoly(glycerol sebacate)/poly(ϵ-caprolactone) (PGS/PCL) biopolymer scaffolds have recently shown promising results in terms of supporting regeneration of RGC neurites. This work explores covalent immobilization of CNTF on PGS/PCL scaffold and the way immobilised CNTF mediates growth of RGC axons on the scaffold. Anex-vivothree-dimensional model of rodent optic nerve on PGS/PCL revealed that RGC explants cultured in CNTF mediated environment increased their neurite extensions after 20 d of cell culture employing neurite outgrowth measurements. The CNTF secretion on PGS/PCL scaffold was found bio-mimicking natural extracellular matrix of the cell target tissue and, consequently, has shown a potential to improve the overall efficacy of the RGC regeneration process.

Cell adhesion molecule immobilized gold surfaces for enhanced neuron-electrode interfaces.

To provide a long-term solution for increasing the biocompatibility of neuroprosthetics, approaches to reduce the side effects of invasive neuro-implantable devices are still in need of improvement. Physical, chemical, and bioactive design aspects of the biomaterials are proven to be important for providing proper cell-to-cell, cell-to-material interactions. Particularly, modification of implant surfaces with bioactive cues, especially cell adhesion molecules (CAMs) that capitalize on native neural adhesion mechanisms, are promising candidates in favor of providing efficient interfaces. Within this concept, this study utilized specific CAMs, namely N-Cadherin (Neural cadherin, N-Cad) and neural cell adhesion molecule (NCAM), to enhance neuron-electrode contact by mimicking the cell-to-ECM interactions for improving the survival of cells and promoting neurite outgrowth. For this purpose, representative gold electrode surfaces were modified with N-Cadherin, NCAM, and the mixture (1:1) of these molecules. Modifications were characterized, and the effect of surface modification on both differentiated and undifferentiated neuroblastoma SH-SY5Y cell lines were compared. The findings demonstrated the successful modification of these molecules which subsequently exhibited biocompatible properties as evidenced by the cell viability results. In cell culture experiments, the CAMs displayed promising results in promoting neurite outgrowth compared to conventional poly-l-lysine coated surfaces, especially NCAM and N-Cad/NCAM modified surfaces clearly showed significant improvement. Overall, this optimized approach is expected to provide an insight into the action mechanisms of cells against the local environment and advance processes for the fabrication of alternative neural interfaces.

Arsenic-induced IGF-1 signaling impairment and neurite shortening: The protective roles of IGF-1 through the PI3K/Akt axis.

We recently reported that arsenic caused insulin resistance in differentiated human neuroblastoma SH-SY5Y cells. Herein, we further investigated the effects of sodium arsenite on IGF-1 signaling, which shares downstream signaling with insulin. A time-course experiment revealed that sodium arsenite began to decrease IGF-1-stimulated Akt phosphorylation on Day 3 after treatment, indicating that prolonged sodium arsenite treatment disrupted the neuronal IGF-1 response. Additionally, sodium arsenite decreased IGF-1-stimulated tyrosine phosphorylation of the IGF-1 receptor ß (IGF-1Rß) and its downstream target, insulin receptor substrate 1 (IRS1). These results suggested that sodium arsenite impaired the intrinsic tyrosine kinase activity of IGF-1Rß, ultimately resulting in a reduction in tyrosine-phosphorylated IRS1. Sodium arsenite also reduced IGF-1 stimulated tyrosine phosphorylation of insulin receptor ß (IRß), indicating the potential inhibition of IGF-1R/IR crosstalk by sodium arsenite. Interestingly, sodium arsenite also induced neurite shortening at the same concentrations that caused IGF-1 signaling impairment. A 24-h IGF-1 treatment partially rescued neurite shortening caused by sodium arsenite. Moreover, the reduction in Akt phosphorylation by sodium arsenite was attenuated by IGF-1. Inhibition of PI3K/Akt by LY294002 diminished the protective effects of IGF-1 against sodium arsenite-induced neurite retraction. Together, our findings suggested that sodium arsenite-impaired IGF-1 signaling, leading to neurite shortening through IGF-1/PI3K/Akt.

Synergy of Nanotopography and Electrical Conductivity of PEDOT/PSS for Enhanced Neuronal Development.

Biomaterials able to promote neuronal development and neurite outgrowth are highly desired in neural tissue engineering for the repair of damaged or disrupted neural tissue and restoring the axonal connection. For this purpose, the use of either electroactive or micro- and nanostructured materials has been separately investigated. Here, the use of a nanomodulated conductive poly(3,4-ethylendioxithiophene) poly(styrenesulfonate) (PEDOT/PSS) substrate that exhibits instructive topographical and electrical cues at the same time was investigated for the first time. In particular, thin films featuring grooves with sizes comparable with those of neuronal neurites (NanoPEDOT) were fabricated by electrochemical polymerization of PEDOT/PSS on a nanomodulated polycarbonate template. The ability of NanoPEDOT to support neuronal development and direct neurite outgrowth was demonstrated by assessing cell viability and proliferation, expression of neuronal markers, average neurite length, and direction of neuroblastoma N2A cells induced to differentiate on this novel support. In addition to the beneficial effect of the nanogrooved topography, a 30% increase was shown in the average length of neurites when differentiating cells were subjected to an electrical stimulation of a few microamperes for 6 h. The results reported here suggest a favorable effect on the neuronal development of the synergistic combination of nanotopography and electrical stimulation, supporting the use of NanoPEDOT in neural tissue engineering to promote physical and functional reconnection of impaired neural networks.

Trabid patient mutations impede the axonal trafficking of adenomatous polyposis coli to disrupt neurite growth.

ZRANB1 (human Trabid) missense mutations have been identified in children diagnosed with a range of congenital disorders including reduced brain size, but how Trabid regulates neurodevelopment is not understood. We have characterized these patient mutations in cells and mice to identify a key role for Trabid in the regulation of neurite growth. One of the patient mutations flanked the catalytic cysteine of Trabid and its deubiquitylating (DUB) activity was abrogated. The second variant retained DUB activity, but failed to bind STRIPAK, a large multiprotein assembly implicated in cytoskeleton organization and neural development. Zranb1 knock-in mice harboring either of these patient mutations exhibited reduced neuronal and glial cell densities in the brain and a motor deficit consistent with fewer dopaminergic neurons and projections. Mechanistically, both DUB-impaired and STRIPAK-binding-deficient Trabid variants impeded the trafficking of adenomatous polyposis coli (APC) to microtubule plus-ends. Consequently, the formation of neuronal growth cones and the trajectory of neurite outgrowth from mutant midbrain progenitors were severely compromised. We propose that STRIPAK recruits Trabid to deubiquitylate APC, and that in cells with mutant Trabid, APC becomes hyperubiquitylated and mislocalized causing impaired organization of the cytoskeleton that underlie the neuronal and developmental phenotypes.

Effects of MAP4K inhibition on neurite outgrowth.

Protein kinases are responsible for protein phosphorylation and are involved in important intracellular signal transduction pathways in various cells, including neurons; however, a considerable number of poorly characterized kinases may be involved in neuronal development. Here, we considered mitogen-activated protein kinase kinase kinase kinases (MAP4Ks), related to as candidate regulators of neurite outgrowth and synaptogenesis, by examining the effects of a selective MAP4K inhibitor PF06260933. PF06260933 treatments of the cultured neurons reduced neurite lengths, not the number of synapses, and phosphorylation of GAP43 and JNK, relative to the control. These results suggest that MAP4Ks are physiologically involved in normal neuronal development and that the resultant impaired neurite outgrowth by diminished MAP4Ks' activity, is related to psychiatric disorders.

Brazilian Green Propolis' Artepillin C and Its Acetylated Derivative Activate the NGF-Signaling Pathways and Induce Neurite Outgrowth in NGF-Deprived PC12 Cells.

Artepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12 cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP-43 and Synapsin I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug-likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF-signaling pathways but through different neuronal proteins. Furthermore, in silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.

Poly(N-acryloylglycine-acrylamide) Hydrogel Mimics the Cellular Microenvironment and Promotes Neurite Growth with Protection from Oxidative Stress.

In this work, the glycine-based acryloyl monomer is polymerized to obtain a neurogenic polymeric hydrogel for regenerative applications. The synthesized poly(N-acryloylglycine-acrylamide) [poly(NAG-b-A)] nanohydrogel exhibits high swelling (∼1500%) and is mechanically very stable, biocompatible, and proliferative in nature. The poly(NAG-b-A) nanohydrogel provides a stable 3D extracellular mimetic environment and promotes healthy neurite growth for primary cortical neurons by facilitating cellular adhesion, proliferation, actin filament stabilization, and neuronal differentiation. Furthermore, the protective role of the poly(NAG-b-A) hydrogel for the neurons in oxidative stress conditions is revealed and it is found that it is a clinically relevant material for neuronal regenerative applications, such as for promoting nerve regeneration via GSK3ß inhibition. This hydrogel additionally plays an important role in modulating the biological microenvironment, either as an agonist and antagonist or as an antioxidant. Furthermore, it favors the physiological responses and eases the neurite growth efficiency. Additionally, we found out that the conversion of glycine-based acryloyl monomers into their corresponding polymer modulates the mechanical performance, mimics the cellular microenvironment, and accelerates the self-healing capability due to the responsive behavior towards reactive oxygen species (ROS). Thus, the p(NAG-b-A) hydrogel could be a potential candidate to induce neuronal regeneration since it provides a physical cue and significantly boosts neurite outgrowth and also maintains the microtubule integrity in neuronal cells.

Viral Entry Inhibitors Protect against SARS-CoV-2-Induced Neurite Shortening in Differentiated SH-SY5Y Cells.

The utility of human neuroblastoma cell lines as in vitro model to study neuro-invasiveness and neuro-virulence of SARS-CoV-2 has been demonstrated by our laboratory and others. The aim of this report is to further characterize the associated cellular responses caused by a pre-alpha SARS-CoV-2 strain on differentiated SH-SY5Y and to prevent its cytopathic effect by using a set of entry inhibitors. The susceptibility of SH-SY5Y to SARS-CoV-2 was confirmed at high multiplicity-of-infection, without viral replication or release. Infection caused a reduction in the length of neuritic processes, occurrence of plasma membrane blebs, cell clustering, and changes in lipid droplets electron density. No changes in the expression of cytoskeletal proteins, such as tubulins or tau, could explain neurite shortening. To counteract the toxic effect on neurites, entry inhibitors targeting TMPRSS2, ACE2, NRP1 receptors, and Spike RBD were co-incubated with the viral inoculum. The neurite shortening could be prevented by the highest concentration of camostat mesylate, anti-RBD antibody, and NRP1 inhibitor, but not by soluble ACE2. According to the degree of entry inhibition, the average amount of intracellular viral RNA was negatively correlated to neurite length. This study demonstrated that targeting specific SARS-CoV-2 host receptors could reverse its neurocytopathic effect on SH-SY5Y.

Droj2 Facilitates Somatosensory Neurite Sculpting via GTP-Binding Protein Arf102F in Drosophila.

Developmental remodeling of neurite is crucial for the accurate wiring of neural circuits in the developing nervous system in both vertebrates and invertebrates, and may also contribute to the pathogenesis of neuropsychiatric disorders, for instance, autism, Alzheimer's disease (AD), and schizophrenia. However, the molecular underpinnings underlying developmental remodeling are still not fully understood. Here, we have identified DnaJ-like-2 (Droj2), orthologous to human DNAJA1 and DNAJA4 that is predicted to be involved in protein refolding, as a developmental signal promoting dendrite sculpting of the class IV dendritic arborization (C4da) sensory neuron in Drosophila. We further show that Arf102F, a GTP-binding protein previously implicated in protein trafficking, serves downstream of Droj2 to govern neurite pruning of C4da sensory neurons. Intriguingly, our data consistently demonstrate that both Droj2 and Arf102F promote the downregulation of the conserved L1-type cell-adhesion molecule Neuroglian anterior to dendrite pruning. Mechanistically, Droj2 genetically interacts with Arf102F and promotes Neuroglian downregulation to initiate dendrite severing. Taken together, this systematic study sheds light on an unprecedented function of Droj2 and Arf102F in neuronal development.

Extracellular Pgk1 interacts neural membrane protein enolase-2 to improve the neurite outgrowth of motor neurons.

Understanding the molecular interaction between ligand and receptor is important for providing the basis for the development of regenerative drugs. Although it has been reported that extracellular phosphoglycerate kinase 1 (Pgk1) can promote the neurite outgrowth of motoneurons, the Pgk1-interacting neural receptor remains unknown. Here we show that neural membranous Enolase-2 exhibits strong affinity with recombinant Pgk1-Flag, which is also evidently demonstrated by immunoelectron microscopy. The 325th-417th domain of Pgk1 interacts with the 405th-431st domain of Enolase-2, but neither Enolase-1 nor Enolase-3, promoting neurite outgrowth. Combining Pgk1 incubation and Enolase-2 overexpression, we demonstrate a highly significant enhancement of neurite outgrowth of motoneurons through a reduced p-P38-T180/p-Limk1-S323/p-Cofilin signaling. Collectively, extracellular Pgk1 interacts neural membrane receptor Enolase-2 to reduce the P38/Limk1/Cofilin signaling which results in promoting neurite outgrowth. The extracellular Pgk1-specific neural receptor found in this study should provide a material for screening potential small molecule drugs that promote motor nerve regeneration.