Molecular Neurobiology最新文献

Inflammation is an important pathogenic driving force in the genesis and development of epilepsy. The latest researches demonstrated that IL-17A mediated blood-brain barrier (BBB) dysfunction through disruption of tight junction protein expression. To investigate whether IL-17A is involved in BBB disruption after acute seizure attack, the pilocarpine model was established with C57BL/6 J (wild type, WT) and IL-17R-deficient mice in vivo and with primary cultured rat brain microvascular endothelial cells in vitro. The mortality rate and brain water content were evaluated at 24 h after status epilepticus, and IL-17A concentration, endothelial tight junction, adherens junction proteins, and albumin leakage were assessed at 0 h, 4 h, 12 h, and 24 h after status epilepticus (SE). IL-17R-deficient mice showed lessen severity of epilepsy than WT mice, accompanied by less albumin leakage, reduced brain water content, decreased IL-17A, and upregulated expression of target proteins (ZO-1, Occludin and VE-cadherin). IL-17R knockout abrogated abnormal upregulation of Src kinase and phosphorylated Src kinase in the setting of SE, and Src kinase inhibitor PP1 abrogated IL-17A-induced SE related endothelial injury in vitro. In conclusion, IL-17A inhibition might be a promising therapeutic option to attenuate endothelial cell injury and further BBB disruption by reducing Src kinase activation.

Intracerebral hemorrhage (ICH) is a subtype of stroke with the highest fatality and disability rate. Up to now, commonly used first-line therapies have limited value in improving prognosis. Angiogenesis is essential to neurological recovery after ICH. Recent studies have shown that microRNA-451(miR-451) plays an important role in angiogenesis by regulating the function of vascular endothelial cells. We found miR-451 was significantly decreased in the peripheral blood of ICH patients in the acute stage. Based on the clinical findings, we conducted this study to investigate the potential regulatory effect of miR-451 on angiogenesis after ICH. The expression of miR-451 in ICH mouse model and in a hemin toxicity model of human brain microvascular endothelial cells (hBMECs) was decreased the same as in ICH patients. MiR-451 negatively regulated the proliferation, migration, and tube formation of hBMECs in vitro. MiR-451 negatively regulated the microvessel density in the perihematoma tissue and affected neural functional recovery of ICH mouse model. Knockdown of miR-451 could recovered tight junction and protect the integrity of blood-brain barrier after ICH. Based on bioinformatic programs, macrophage migration inhibitory factor (MIF) was predicted to be the target gene and identified to be regulated by miR-451 inhibiting the protein translation. And p-AKT and p-ERK were verified to be downstream of MIF in angiogenesis. These results all suggest that miR-451 will be a potential target for regulating angiogenesis in ICH.

Spinal cord injury (SCI) is a severe neurological condition that can lead to paralysis or even death. This study explored the potential benefits of bone marrow mesenchymal stem cell (BMSC) transplantation for repairing SCI. BMSCs also differentiate into astrocytes within damaged spinal cord tissues hindering the cell transplantation efficacy, therefore it is crucial to enhance their neuronal differentiation rate to facilitate spinal cord repair. Wnt5a, an upstream protein in the non-classical Wnt signaling pathway, has been implicated in stem cell migration, differentiation, and neurite formation but its role in the neuronal differentiation of BMSCs remains unclear. Thus, this study investigated the role and underlying mechanisms of Wnt5a in promoting neuronal differentiation of BMSCs both in vivo and in vitro. Wnt5a enhanced neuronal differentiation of BMSCs in vitro while reducing astrocyte differentiation. Additionally, high-throughput RNA sequencing revealed a correlation between Wnt5a and phosphoinositide 3-kinase (PI3K)/protein kinase B(AKT) signaling, which was confirmed by the use of the PI3K inhibitor LY294002 to reverse the effects of Wnt5a on BMSC neuronal differentiation. Furthermore, transplantation of Wnt5a-modified BMSCs into SCI rats effectively improved the histomorphology (Hematoxylin and eosin [H&E], Nissl and Luxol Fast Blue [LFB] staining), motor function scores (Footprint test and Basso-Beattie-Bresnahan [BBB]scores)and promoted neuron production, axonal formation, and remodeling of myelin sheaths (microtubule associated protein-2 [MAP-2], growth-associated protein 43 [GAP43], myelin basic protein [MBP]), while reducing astrocyte production (glial fibrillary acidic protein [GFAP]). Therefore, targeting the Wnt5a/PI3K/AKT pathway could enhance BMSC transplantation for SCI treatment.

Secondary injury presents a significant hurdle to neural regeneration following spinal cord injury (SCI), primarily driven by inflammation in which microglial cells play a crucial role. Despite the growing interest in mitophagy, studies on its occurrence post-spinal cord injury, particularly within microglial cells, are scarce. While P2Y6R has been implicated in inflammation regulation in various neurological conditions, its specific role in SCI remains uncertain. Our study revealed an upregulation of P2Y6R expression following SCI notably in microglial cells. Treatment with the P2Y6R-specific inhibitor, MRS2578, in mice facilitated M2 polarization of microglial cells and alleviated secondary damage, ultimately enhancing neural regeneration and functional recovery. In an in vitro BV2 inflammation model, our findings indicate that P2Y6R inhibition induced M2 polarization of BV2 cells and reduced neuroinflammation through PINK/Parkin-dependent mitophagy activation. In summary, our results underscore the potential of P2Y6R inhibition in promoting mitophagy-induced M2 polarization of microglial cells, thereby ameliorating secondary injury following spinal cord injury.

Alpha-synuclein (α-syn) is a major pathological marker of Parkinson's disease (PD), and its abnormal expression and aggregation lead to dopaminergic neuron degeneration, in which oxidative stress plays an important role. However, the exact molecular mechanism by which α-syn causes PD remains unclear. In this study, exogenous α-syn, also known as α-syn preformed fibrils (α-syn PFFs), was used to construct in vivo and in vitro models of PD. Behavioral, Western blotting, biochemical, immunofluorescence, flow cytometry, electron microscopy, etc. were used to investigate the pathological mechanism of PD induced by α-syn. We found that 6 months after striatum injection of α-syn PFFs, mice exhibited motor deficits. Meanwhile, the protein expression of pS129-α-syn (p-α-syn) and α-syn oligomer significantly increased, while the expression of TH significantly decreased, and the oxidative stress in the substantia nigra was aggravated. In addition, we found an increase in the protein expression of NMDAR2B and p-Tyr1472-NMDAR2B (p-NMDAR2B) and a decrease in the protein expression of Nur77. However, in α-syn PFFs-induced SH-SY5Y cells, we found that inhibiting p-NMDAR2B increased the protein expression of Nur77, while overexpression of Nur77 did not affect the expression of p-NMDAR2B. Inhibition of p-NMDAR2B and overexpression of Nur77 reversed α-syn PFF-induced oxidative stress, thus reducing mitochondrial damage and cytotoxicity. Therefore, we speculate that α-syn PFF-induced oxidative stress in dopaminergic neurons may be mediated by p-NMDAR2B/Nur77. Our study provides novel insights into the pathology mechanism underlying α-syn-induced PD.

Depression often occurs in patients with additional co-morbidities, particularly in cases of chronic pain. Currently, there is a lack of research on the molecular mechanisms of depression under chronic pain conditions and suitable animal models. Due to the contradiction exhibited by platelet-derived growth factor receptor (PDGF/PDGFR) in neuroprotection, further investigation is required. In the present study, we investigated the roles of PDGFR-α in the hippocampus based on rat models of chronic pain (myofascial pain syndrome, MPS) that exhibited depressive phenotypes. The depression-like phenotypes were assessed by the sucrose preference test, forced swimming test, tail suspension test, and the levels of BDNF and 5HT1AR. Electron microscopic analysis and altered expression of autophagy-related proteins revealed reduced autophagy levels in the hippocampus of MPS rats. Phosphorylation PDGFR-α was significantly upregulated in the MPS rat model of depression, as well as the levels of inflammatory factors and p-JAK2/p-STAT3. Treatment with inhibitors of PDGFR-α or JAK2/STAT3 alleviated depressive behaviors, Nissl bodies staining, increased the protein levels of BDNF and 5HT1AR, and decreased the levels of inflammatory factors in MPS rats. Additionally, it restored autophagy levels. These results indicate that PDGFR-α induces neuroinflammation, altered autophagy, and depressive behavior, potentially mediated by the JAK2/STAT3 signaling pathway in MPS rats. PDGFR-α may thus represent a promising therapeutic target for the treatment of this type of depression.

Core fucosylation at N-glycans, which is uniquely catalyzed by fucosyltransferase FUT8, plays essential roles in post-translational regulation of protein function. Aberrant core fucosylation leads to neurological disorders in individuals with congenital glycosylation disorders (CDG). However, the underlying mechanisms for these neurological defects remain largely unknown. In this study, we have showed that FUT8 and fucosylation are abundant in cerebellum. Specific deletion of Fut8 in cerebellar granule neuron progenitors (GNPs) results in the impaired proliferation and differentiation of GNPs, as well as the compromised neuronal development, synaptic physiology and motor coordination. Mechanistically, we have showed that Fut8 deficiency reduced Contactin 2 (Cntn2) expression, a member of neural cell adhesion molecules (NCAMs). Furthermore, ectopic Cntn2 can rescue the neuronal defects induced by Fut8 deficiency. Collectively, our study has revealed the important roles of FUT8 and core fucosylation in regulating cerebellar development and function through modulating Cntn2 expression.

Spinal muscular atrophy (SMA) is a neuromuscular disorder resulting in the loss of α-motor neurons. Nusinersen is an antisense oligonucleotide administered intrathecally to SMA patients that corrects the splicing defect of SMN2. Not all SMA patients respond equally to the therapy and work is in progress to identify biomarkers that may help stratify to SMA patients. In this study, we evaluated the expression of SMN circular RNAs (circRNAs) as potential biomarkers of the disease. This monocentric study was conducted at Fondazione Policlinico A. Gemelli in collaboration with Catholic University of Sacred Heart between December 2019 and March 2023. The inclusion criteria comprised having a diagnosis of SMA I and being treated with Nusinersen. The quantitative analysis of SMN circ4-2b-3 was conducted analyzing patients' serum-derived exosomes. The study included 19 type I SMA patients. Among several SMN circRNAs expressed in SMA cells, only SMN circ4-2b-3 was also detected in exosomes isolated from both type I SMA cell lines and patient-derived serum. High copy number of SMN circ4-2b-3 occurred in a small subgroup of type I SMA patients who were defined as super-responders, based on their response to the Nusinersen therapy. The levels of this circRNA remained high over time. Our results suggest that SMN circ4-2b-3 is a potential biomarker to predict the therapeutic response of type I SMA patients to Nusinersen. However, since other super-responders had a lower number of SMN circ4-2b-3 copies, these findings should be confirmed in larger cohorts.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by multiple dysfunctions in behavior, the nervous system, and the immune system. Increasing evidence suggests that mitochondrial DNA (mtDNA) plays a crucial role in the pathology of ASD. In clinical practice, altered mtDNA levels have been observed in various tissues of individuals with ASD. Mutation or oxidation of mtDNA is also closely related to the immune response associated with the pathology of autism. With mtDNA identified as a causal factor, much interest has focused on how its production affects neurodevelopment and neurophysiology. Here, we review how mtDNA leads to dysfunction of cellular mitochondria and immune response. We also illustrate the relationship between mtDNA alterations and the pathology of autism. Finally, we discuss the existing evidence on cell-free mtDNA associated with ASD and look forward to its application in clinical diagnosis and treatment.

The coordination of neuronal wiring and activity within the central nervous system (CNS) is crucial for cognitive function, particularly in the context of aging and neurological disorders. Neurogranin (Ng), an abundant forebrain protein, modulates calmodulin (CaM) activity and deeply influences synaptic plasticity and neuronal processing. This study investigates the regulatory mechanisms of Ng expression, a critical but underexplored area for combating cognitive impairment. Utilizing both in vitro and in vivo hippocampal models, we show that Ng expression arises during late developmental stages, coinciding with the processes of synaptic maturation and neuronal circuit consolidation. We observed that Ng expression increases in neuronal networks with heightened synaptic activity and identified GluN2B-containing N-methyl-D-aspartate (NMDA) receptors as key drivers of this expression. Additionally, we discovered that nuclear-localized HDAC4 inhibits Ng expression, establishing a regulatory axis that is counteracted by NMDA receptor stimulation. Analysis of the Ng gene promoter activity revealed regulatory elements between the - 2.4 and - 0.85 Kbp region, including a binding site for RE1-Silencing Transcription factor (REST), which may mediate HDAC4's repressive effect on Ng expression. Further analysis of the promoter sequence revealed conserved binding sites for the myocyte enhancer factor-2 (MEF2) transcription factor, a target of HDAC4-mediated transcription regulation. Our findings elucidate the interplay between synaptic activity, NMDAR function, and transcriptional regulation in controlling Ng expression, offering insights into synaptic plasticity mechanisms and potential therapeutic strategies to prevent cognitive dysfunction.