RESUMO
Contactin 2 (CNTN2) is a cell adhesion molecule involved in axon guidance, neuronal migration, and fasciculation. The ectodomains of CNTN1-CNTN6 are composed of six Ig domains (Ig1-Ig6) and four FN domains. Here, we show that CNTN2 forms transient homophilic interactions (KD â¼200 nM). Cryo-EM structures of full-length CNTN2 and CNTN2_Ig1-Ig6 reveal a T-shaped homodimer formed by intertwined, parallel monomers. Unexpectedly, the horseshoe-shaped Ig1-Ig4 headpieces extend their Ig2-Ig3 tips outwards on either side of the homodimer, while Ig4, Ig5, Ig6, and the FN domains form a central stalk. Cross-linking mass spectrometry and cell-based binding assays confirm the 3D assembly of the CNTN2 homodimer. The interface mediating homodimer formation differs between CNTNs, as do the homophilic versus heterophilic interaction mechanisms. The CNTN family thus encodes a versatile molecular platform that supports a very diverse portfolio of protein interactions and that can be leveraged to strategically guide neural circuit development.
RESUMO
BACKGROUND: The relationship between lifestyle and migraine is complex, as it remains uncertain which specific lifestyle factors play the most prominent role in the development of migraine, or which modifiable metabolic traits serve as mediators in establishing causality. METHODS: Independent genetic variants strongly associated with 20 lifestyle factors were selected as instrumental variables from corresponding genome-wide association studies (GWASs). Summary-level data for migraine were obtained from the FinnGen consortium (18,477 cases and 287,837 controls) as a discovery set and the GWAS meta-analysis data (26,052 cases and 487,214 controls) as a replication set. Estimates derived from the two datasets were combined using fixed-effects meta-analysis. Two-step univariable MR (UVMR) and multivariable Mendelian randomization (MVMR) analyses were conducted to evaluate 19 potential mediators of association and determine the proportions of these mediators. RESULTS: The combined effect of inverse variance weighted revealed that a one standard deviation (SD) increase in genetically predicted Leisure screen time (LST) was associated with a 27.7% increase (95% CI: 1.14-1.44) in migraine risk, while Moderate or/and vigorous physical activity (MVPA) was associated with a 26.9% decrease (95% CI: 0.61-0.87) in migraine risk. The results of the mediation analysis indicated that out of the 19 modifiable metabolic risk factors examined, hypertension explains 24.81% of the relationship between LST and the risk of experiencing migraine. Furthermore, hypertension and diastolic blood pressure (DBP) partially weaken the association between MVPA and migraines, mediating 4.86% and 4.66% respectively. CONCLUSION: Our research findings indicated that both LST and MVPA in lifestyle have independent causal effects on migraine. Additionally, we have identified that hypertension and DBP play a mediating role in the causal pathway between these two factors and migraine.
Assuntos
Exercício Físico , Estudo de Associação Genômica Ampla , Hipertensão , Análise da Randomização Mendeliana , Transtornos de Enxaqueca , Tempo de Tela , Humanos , Transtornos de Enxaqueca/genética , Transtornos de Enxaqueca/epidemiologia , Transtornos de Enxaqueca/fisiopatologia , Exercício Físico/fisiologia , Hipertensão/genética , Hipertensão/epidemiologia , Atividades de LazerRESUMO
Migraine is the second highest cause of disability worldwide, bringing a huge socioeconomic burden. Improving mitochondrial function has promise as an effective treatment strategy for migraine. Szeto-Schiller peptide (SS-31) is a new mitochondria-targeted tetrapeptide molecule that has been shown to suppress the progression of diseases by restoring mitochondrial function, including renal disease, cardiac disease, and neurodegenerative disease. However, whether SS-31 has a therapeutic effect on migraine remains unclear. The aim of this study is to clarify the treatment of SS-31 for headache and its potential mechanisms. Here we used a mouse model induced by repeated dural infusion of inflammatory soup (IS), and examined roles of Sirt3/Pgc-1α positive feedback loop in headache pathogenesis and mitochondrial function. Our results showed that repeated IS infusion impaired mitochondrial function, mitochondrial ultrastructure and mitochondrial homeostasis in the trigeminal nucleus caudalis (TNC). These IS-induced damages in TNC were reversed by SS-31. In addition, IS-induced nociceptive responses were simultaneously alleviated. The effects of SS-31 on mitochondrial function and mitochondrial homeostasis (mainly mitochondrial biogenesis) were attenuated partially by the inhibitor of Sirt3/Pgc-1α. Overexpression of Sirt3/Pgc-1α increased the protein level of each other. These results indicated that SS-31 alleviated nociceptive responses and restored mitochondrial function in an IS-induced headache mouse model via Sirt3/Pgc-1α positive feedback loop. SS-31 has the potential to be an effective drug candidate for headache treatment.
Assuntos
Transtornos de Enxaqueca , Doenças Neurodegenerativas , Sirtuína 3 , Camundongos , Animais , Sirtuína 3/metabolismo , Sirtuína 3/farmacologia , Retroalimentação , Doenças Neurodegenerativas/metabolismo , Nociceptividade , Mitocôndrias/metabolismo , Modelos Animais de Doenças , Cefaleia/metabolismo , Transtornos de Enxaqueca/metabolismoRESUMO
Background: Targeting metabolic pathways has emerged as a new migraine treatment strategy as researchers realize the critical role metabolism plays in migraine. Activated inflammatory cells undergo metabolic reprogramming and rely on glycolysis to function. The objective of this study was to investigate the glycolysis changes in the experimental model of migraine and the effect of glycolysis inhibitor 2-Deoxy-D-glucose (2-DG) in the pathophysiology of migraine. Methods: We used a rat model of migraine that triggered migraine attacks by applying inflammatory soup (IS) to the dura and examined changes in glycolysis. 2-DG was used to inhibit glycolysis, and the effects of 2-DG on mechanical ectopic pain, microglial cell activation, calcitonin gene-related peptides (CGRP), c-Fos, and inflammatory factors induced by inflammatory soup were observed. LPS stimulated BV2 cells to establish a model in vitro to observe the effects of 2-DG on brain-derived neurotrophic factor (BDNF) after microglia activation. Results: In the experimental model of migraine, key enzymes involved in glycolysis such as phosphofructokinase platelet (PFKP), hexokinase (HK2), hypoxia inducible factor-1α (HIF-1α), lactate dehydrogenase (LDH) and pyruvate kinase (PKM2) were expressed in the medullary dorsal horn. While the expression of electronic respiratory transport chain complex IV (COXIV) decreased. There were no significant changes in glucose 6-phosphate dehydrogenase (G6PD), a key enzyme in the pentose phosphate pathway. The glycolysis inhibitor 2-DG alleviated migraine-like symptoms in an experimental model of migraine, reduced the release of proinflammatory cytokines caused by microglia activation, and decreased the expression of CGRP and c-Fos. Further experiments in vitro demonstrated that glycolysis inhibition can reduce the release of Iba-1/proBDNF/BDNF and inhibit the activation of microglia. Conclusion: The migraine rat model showed enhanced glycolysis. This study suggests that glycolytic inhibitor 2-DG is an effective strategy for alleviating migraine-like symptoms. Glycolysis inhibition may be a new target for migraine treatment.
RESUMO
MDGAs (MAM domain-containing glycosylphosphatidylinositol anchors) are synaptic cell surface molecules that regulate the formation of trans-synaptic bridges between neurexins (NRXNs) and neuroligins (NLGNs), which promote synaptic development. Mutations in MDGAs are implicated in various neuropsychiatric diseases. MDGAs bind NLGNs in cis on the postsynaptic membrane and physically block NLGNs from binding to NRXNs. In crystal structures, the six immunoglobulin (Ig) and single fibronectin III domains of MDGA1 reveal a striking compact, triangular shape, both alone and in complex with NLGNs. Whether this unusual domain arrangement is required for biological function or other arrangements occur with different functional outcomes is unknown. Here, we show that WT MDGA1 can adopt both compact and extended 3D conformations that bind NLGN2. Designer mutants targeting strategic molecular elbows in MDGA1 alter the distribution of 3D conformations while leaving the binding affinity between soluble ectodomains of MDGA1 and NLGN2 intact. In contrast, in a cellular context, these mutants result in unique combinations of functional consequences, including altered binding to NLGN2, decreased capacity to conceal NLGN2 from NRXN1ß, and/or suppressed NLGN2-mediated inhibitory presynaptic differentiation, despite the mutations being located far from the MDGA1-NLGN2 interaction site. Thus, the 3D conformation of the entire MDGA1 ectodomain appears critical for its function, and its NLGN-binding site on Ig1-Ig2 is not independent of the rest of the molecule. As a result, global 3D conformational changes to the MDGA1 ectodomain via strategic elbows may form a molecular mechanism to regulate MDGA1 action within the synaptic cleft.
Assuntos
Moléculas de Adesão de Célula Nervosa , Sinapses , Moléculas de Adesão de Célula Nervosa/genética , Moléculas de Adesão de Célula Nervosa/metabolismo , Sinapses/metabolismo , Sítios de Ligação , Imunoglobulinas/genética , Imunoglobulinas/metabolismo , Conformação Molecular , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismoRESUMO
BACKGROUND: Iron-refractory iron deficiency anaemia (IRIDA) is an autosomal recessive iron deficiency anaemia caused by mutations in the TMPRSS6 gene. Iron deficiency anaemia is common, whereas IRIDA is rare. The prevalence of IRIDA is unclear. This study aimed to estimate the carrier frequency and genetic prevalence of IRIDA using Genome Aggregation Database (gnomAD) data. METHODS: The pathogenicity of TMPRSS6 variants was interpreted according to the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) standards and guidelines. The minor allele frequency (MAF) of TMPRSS6 gene disease-causing variants in 141,456 unique individuals was examined to estimate the global prevalence of IRIDA in seven ethnicities: African/African American (afr), American Admixed/Latino (amr), Ashkenazi Jewish (asj), East Asian (eas), Finnish (fin), Non-Finnish European (nfe) and South Asian (sas). The global and population-specific carrier frequencies and genetic prevalence of IRIDA were calculated using the Hardy-Weinberg equation. RESULTS: In total, 86 pathogenic/likely pathogenic variants (PV/LPV) were identified according to ACMG/AMP guideline. The global carrier frequency and genetic prevalence of IRIDA were 2.02 per thousand and 1.02 per million, respectively. CONCLUSIONS: The prevalence of IRIDA is greater than previous estimates.
Assuntos
Anemia Ferropriva , Humanos , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/genética , Prevalência , Mutação/genética , Frequência do Gene/genéticaRESUMO
The AP1 transcription factor ΔFOSB, a splice variant of FOSB, accumulates in the brain in response to chronic insults such as exposure to drugs of abuse, depression, Alzheimer's disease and tardive dyskinesias, and mediates subsequent long-term neuroadaptations. ΔFOSB forms heterodimers with other AP1 transcription factors, e.g. JUND, that bind DNA under control of a putative cysteine-based redox switch. Here, we reveal the structural basis of the redox switch by determining a key missing crystal structure in a trio, the ΔFOSB/JUND bZIP domains in the reduced, DNA-free form. Screening a cysteine-focused library containing 3200 thiol-reactive compounds, we identify specific compounds that target the redox switch, validate their activity biochemically and in cell-based assays, and show that they are well tolerated in different cell lines despite their general potential to bind to cysteines covalently. A crystal structure of the ΔFOSB/JUND bZIP domains in complex with a redox-switch-targeting compound reveals a deep compound-binding pocket near the DNA-binding site. We demonstrate that ΔFOSB, and potentially other, related AP1 transcription factors, can be targeted specifically and discriminately by exploiting unique structural features such as the redox switch and the binding partner to modulate biological function despite these proteins previously being thought to be undruggable.
Assuntos
Cisteína , Proteínas Proto-Oncogênicas c-fos , Proteínas Proto-Oncogênicas c-fos/metabolismo , Cisteína/genética , Cisteína/metabolismo , Regulação da Expressão Gênica , DNA/genética , DNA/metabolismo , Oxirredução , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismoRESUMO
Migraine is the second most common form of headache disorder and the second leading cause of disability worldwide. Cognitive symptoms ranked second resulting in migraine-related disability, after pain. P2X7 receptor (P2X7R) was recently shown to be involved in hyperalgesia in migraine. However, the role of P2X7R in migraine-related cognitive impairment is still ill-defined. The aim of this study was to explore the molecular mechanisms underlying migraine-related cognitive impairment and the role of P2X7R in it. Here we used a well-established mouse model of migraine that triggered migraine attacks by application of inflammatory soup (IS) to the dura. Our results showed that repeated dural IS stimulation triggered upregulation of P2X7R, activation of NLRP3 inflammasome, release of proinflammatory cytokines (IL-1ß and IL-18) and activation of pyroptotic cell death pathway. Gliosis (microgliosis and astrogliosis), neuronal loss and cognitive impairment also occurred in the IS-induced migraine model. No significant apoptosis or whiter matter damage was observed following IS-induced migraine attacks. These pathological changes occurred mainly in the cerebral cortex and to a less extent in the hippocampus, all of which can be prevented by pretreatment with a specific P2X7R antagonist Brilliant Blue G (BBG). Moreover, BBG can alleviate cognitive impairment following dural IS stimulation. These results identified P2X7R as a key contributor to migraine-related cognitive impairment and may represent a potential therapeutic target for mitigating cognitive impairment in migraine.
Assuntos
Disfunção Cognitiva , Transtornos de Enxaqueca , Proteína 3 que Contém Domínio de Pirina da Família NLR , Receptores Purinérgicos P2X7 , Animais , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Camundongos , Transtornos de Enxaqueca/complicações , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Doenças Neuroinflamatórias/genética , Doenças Neuroinflamatórias/metabolismo , Piroptose/genética , Piroptose/fisiologia , Receptores Purinérgicos P2X7/metabolismo , Transdução de Sinais/fisiologiaRESUMO
OBJECTIVE: Fear aura has traditionally been considered relevant to epileptic discharges from mesial temporal areas, and few studies have investigated its effect on surgical outcome in drug-resistant epilepsy. We aim to assess the localizing and lateralizing value as well as prognostic significance of fear aura in patients with focal epilepsy. METHODS: The occurrence of fear aura in relation to epileptogenic origin and its association with postoperative outcome were analyzed in 146 consecutive patients undergoing resective surgery for intractable epilepsy. RESULTS: Ninety-four (64.4%) patients reported auras, and 31 (21.2%) reported fear aura in their seizures. One hundred ten (75.3%) patients had an Engel class I outcome until last follow-up, of whom 24 experienced fear aura preoperatively. Fear aura appeared more frequently during temporal and frontal lobe seizures, but did not lateralize the seizure onset zone. There were no significant baseline differences between patients with and without fear aura. No correlation was found between postoperative outcome and the presence of auras. Occurrence of fear aura failed to show predictive value in surgical outcome whether in pooled or subgroup analysis. INTERPRETATION: This study advances our understanding of the origin of fear aura, and is helpful for presurgical evaluation and outcome prediction. Without lateralizing value, fear aura is more commonly seen with temporal or frontal origin. When taken as a whole, auras do not have a significant impact on seizure outcome in focal epilepsy. Patients with fear aura are no more likely to become seizure-free than those without fear aura.
Assuntos
Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Epilepsia , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsias Parciais/cirurgia , Medo , Humanos , Prognóstico , Convulsões , Lobo TemporalRESUMO
A simple and versatile strategy for controlled production of monodisperse ethyl cellulose (EC) microcapsules by a single-stage emulsification method has been developed. Monodisperse oil-in-water emulsions, obtained by a microfluidic device, are used as templates for preparing EC microcapsules. Oil-soluble ethyl acetate (EA) is miscible with water, so the interfacial mass transfer between EA and water occurs sufficiently, which leads to water molecules pass through the phase interface and diffuse into emulsion interior. Water molecules aggregate at the interface, and some merge into a large water drop in the central position of the emulsion. After evaporation of EA solvent, monodisperse EC microcapsules create large numbers of pits on the surface with a hollow structure. Curcumin is used as a model drug and embedded in the hollow structure. EC microcapsules have good, sustained drug release efficacy in a simulated intestinal environment, and the release process of EC microcapsules containing 6.14% drug-loaded capacity is fully consistent with the vitro drug release model. Such simple techniques for making EC microcapsules may open a window to the controlled preparation of other multifunctional microcapsules. Besides, it offers theoretical guidance for the study of EC microcapsules as drug carriers and expanding clinical application of curcumin.
Assuntos
Curcumina , Cápsulas/química , Celulose/análogos & derivados , Preparações de Ação Retardada , Emulsões/química , Tamanho da Partícula , Água/químicaRESUMO
The nature and magnitude of nocebo responses in primary headache disorders are still unknown. To assess the distribution and possible predictors of nocebo responses in primary headache treatments, databases, including PubMed, EMBASE, and Cochrane Library were searched from 1988 to December 31, 2020, for parallel-group, double-blind, randomized placebo-controlled trials of pharmacologic treatments of primary headaches. The nocebo responses were calculated using a random effects meta-analysis model. Subgroup and metaregression analyses were performed to determine the associations of study design and demographic characteristics with nocebo responses. A total of 178 randomized controlled trials that satisfied the inclusion criteria were included. Prophylactic treatments elicited stronger nocebo responses than acute treatments. The majority of nocebo adverse events were mild to moderate in severity, with the nervous and digestive systems being the most commonly affected. There was a strong correlation between the active medication and control groups in terms of adverse events, both quantitatively and qualitatively. Long treatment duration, a high proportion of subjects receiving active medications, multicenter design, North America, high body mass index, women, previous treatment experiences, and a high proportion of patients with migraine headache with aura were all found to be significant positive predictors of nocebo responses, whereas the year of publication was found to be inversely related to them. Nocebo effects should be noticed for their contribution to discontinuation of or lack of adherence to active treatments. Clarifying these nocebo-related risk factors can aid in their clinical prevention and management.
Assuntos
Transtornos de Enxaqueca , Efeito Nocebo , Método Duplo-Cego , Feminino , Cefaleia/tratamento farmacológico , Humanos , Transtornos de Enxaqueca/tratamento farmacológico , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de RiscoRESUMO
BACKGROUND: The incidence of migraines is higher among individuals with epilepsy than in healthy individuals, and these two diseases are thought to shared pathophysiological mechanisms. Excitation/inhibition imbalance plays an essential role in the comorbidity of epilepsy and migraine. Microglial activation is crucial for abnormal neuronal signal transmission. However, it remains unclear whether and how microglia are activated and their role in comorbidities after being activated. This study aimed to explore the characteristics and mechanism of microglial activation after seizures and their effect on migraine. METHODS: Model rats of status epilepticus (SE) induced by intraperitoneal injection of lithium chloride (LiCl)-pilocarpine and migraine induced by repeated dural injections of inflammatory soup (IS) were generated, and molecular and histopathologic evidence of the microglial activation targets of fractalkine (FKN) signalling were examined. HT22-BV2 transwell coculture assays were used to explore the interaction between neurons and microglia. LPS (a microglial agonist) and FKN stimulation of BV2 microglial cells were used to evaluate changes in BDNF levels after microglial activation. RESULTS: Microglia were specifically hyperplastic and activated in the temporal lobe cortex, thalamus, and spinal trigeminal nucleus caudalis (sp5c), accompanied by the upregulation of FKN and CX3CR1 four days after seizures. Moreover, SE-induced increases in nociceptive behaviour and FKN/CX3CR1 axis expression in migraine model rats. AZD8797 (a CX3CR1 inhibitor) prevented the worsening of hyperalgesia and microglial activation in migraine model rats after seizures, while FKN infusion in migraine model rats exacerbated hyperalgesia and microglial activation associated with BDNF-Trkb signalling. Furthermore, in neuron-microglia cocultures, microglial activation and FKN/CX3CR1/BDNF/iba1 expression were increased compared with those in microglial cultures alone. Activating microglia with LPS and FKN increased BDNF synthesis in BV2 microglia. CONCLUSIONS: Our results indicated that epilepsy facilitated migraine through FKN/CX3CR1 axis-mediated microglial activation in the cortex/thalamus/sp5c, which was accompanied by BDNF release. Blocking the FKN/CX3CR1 axis and microglial activation are potential therapeutic strategies for preventing and treating migraine in patients with epilepsy.
Assuntos
Receptor 1 de Quimiocina CX3C , Quimiocina CX3CL1 , Transtornos de Enxaqueca , Estado Epiléptico , Animais , Receptor 1 de Quimiocina CX3C/metabolismo , Quimiocina CX3CL1/metabolismo , Humanos , Microglia/metabolismo , Transtornos de Enxaqueca/metabolismo , Ratos , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/metabolismo , Estado Epiléptico/patologia , Tálamo/metabolismoRESUMO
GNAL mutations (DYT25) have lately been identified as the firstly proven cause of focal adult-onset dystonia. We report here a new mutation in the GNAL gene in two siblings with dystonia. The new mutation is called NM 001,142,339:c.97C > T. Our research emphasizes the possible effects of new mutation on disease risk and the significance of genetic tests for GNAL mutations in confirming the molecular diagnosis.
Assuntos
Distonia , Distúrbios Distônicos , Adulto , Distonia/genética , Distúrbios Distônicos/genética , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Testes Genéticos , Humanos , Mutação/genéticaRESUMO
BACKGROUND: Upshaw-Schulman syndrome (USS) is an autosomal recessive disease characterized by thrombotic microangiopathies caused by pathogenic variants in ADAMTS13. We aimed to (1) curate the ADAMTS13 gene pathogenic variant dataset and (2) estimate the carrier frequency and genetic prevalence of USS using Genome Aggregation Database (gnomAD) data. METHODS: Studies were comprehensively retrieved. All previously reported pathogenic ADAMTS13 variants were compiled and annotated with gnomAD allele frequencies. The pooled global and population-specific carrier frequencies and genetic prevalence of USS were calculated using the Hardy-Weinberg equation. RESULTS: We mined reported disease-causing variants that were present in the gnomAD v2.1.1, filtered by allele frequency. The pathogenicity of variants was classified according to the American College of Medical Genetics and Genomics criteria. The genetic prevalence and carrier frequency of USS were 0.43 per 1 million (95% CI: [0.36, 0.55]) and 1.31 per 1 thousand population, respectively. When the novel pathogenic/likely pathogenic variants were included, the genetic prevalence and carrier frequency were 1.1 per 1 million (95% CI: [0.89, 1.37]) and 2.1 per 1 thousand population, respectively. CONCLUSIONS: The genetic prevalence and carrier frequency of USS were within the ranges of previous estimates.
Assuntos
Púrpura Trombocitopênica Trombótica/epidemiologia , Púrpura Trombocitopênica Trombótica/genética , Frequência do Gene , Humanos , PrevalênciaRESUMO
OBJECTIVE: To evaluate the improvement of motor, anxiety, and depression in patients with blepharospasm with the use of botulinum toxin type A (BTX-A) and repetitive transcranial magnetic stimulation (rTMS). METHODS: A total of 63 BEB patients accompanied by anxiety/depression were enrolled, among which 28 patients were treated with the injection of botulinum toxin type A (BTX-A) alone, while 35 patients were treated with BTX-A injection combined with rTMS. All patients were followed up for 6 months, and the overall efficacy was evaluated. RESULTS: BTX-A alone treatment and combined rTMS treatment could both significantly improve the symptoms of patients, and the effective rate was 92.86% and 94.29%, respectively. The duration of efficacy was significantly longer in the combined rTMS treatment group (16.89±3.39 weeks) than in BTX-A treatment group (13.04±3.48 weeks). After treatment, SDS score of BTX-A treatment group and combined rTMS treatment group was 49.69±7.90 and 49.46±6.73, respectively, and there was no significant difference between the two treatment groups; SAS score of BTX-A treatment group and combined rTMS treatment group was 53.88±7.34 and 48.79±6.62, respectively, and there was significant difference between the two treatment groups. CONCLUSION: Compared to BTX-A alone treatment, BTX-A combined with rTMS can effectively improve the effect of BTX-A, prolong the duration of blepharospasm relief, and significantly reduce depression and anxiety in patients with BEB.
RESUMO
Hevin is secreted by astrocytes and its synaptogenic effects are antagonized by the related protein, SPARC. Hevin stabilizes neurexin-neuroligin transsynaptic bridges in vivo. A third protein, membrane-tethered MDGA, blocks these bridges. Here, we reveal the molecular underpinnings of a regulatory network formed by this trio of proteins. The hevin FS-EC structure differs from SPARC, in that the EC domain appears rearranged around a conserved core. The FS domain is structurally conserved and it houses nanomolar affinity binding sites for neurexin and neuroligin. SPARC also binds neurexin and neuroligin, competing with hevin, so its antagonist action is rooted in its shortened N-terminal region. Strikingly, the hevin FS domain competes with MDGA for an overlapping binding site on neuroligin, while the hevin EC domain binds the extracellular matrix protein collagen (like SPARC), so that this trio of proteins can regulate neurexin-neuroligin transsynaptic bridges and also extracellular matrix interactions, impacting synapse formation and ultimately neural circuits.
Assuntos
Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas da Matriz Extracelular/química , Proteínas da Matriz Extracelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Osteonectina/química , Osteonectina/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Humanos , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Mapas de Interação de ProteínasRESUMO
Neuronal growth regulator 1 (NEGR1) and neurotrimin (NTM) are abundant cell-surface proteins found in the brain and form part of the IgLON (Immunoglobulin LSAMP, OBCAM, Neurotrimin) family. In humans, NEGR1 is implicated in obesity and mental disorders, while NTM is linked to intelligence and cognitive function. IgLONs dimerize homophilically and heterophilically, and they are thought to shape synaptic connections and neural circuits by acting in trans (spanning cellular junctions) and/or in cis (at the same side of a junction). Here, we reveal homodimeric structures of NEGR1 and NTM. They assemble into V-shaped complexes via their Ig1 domains, and disruption of the Ig1-Ig1 interface abolishes dimerization in solution. A hydrophobic ridge from one Ig1 domain inserts into a hydrophobic pocket from the opposing Ig1 domain producing an interaction interface that is highly conserved among IgLONs but remarkably plastic structurally. Given the high degree of sequence conservation at the interaction interface, we tested whether different IgLONs could elicit the same biological effect in vivo. In a small-scale study administering different soluble IgLONs directly into the brain and monitoring feeding, only NEGR1 altered food intake significantly. Taking NEGR1 as a prototype, our studies thus indicate that while IgLONs share a conserved mode of interaction and are able to bind each other as homomers and heteromers, they are structurally plastic and can exert unique biological action.
Assuntos
Moléculas de Adesão Celular Neuronais/química , Moléculas de Adesão de Célula Nervosa/química , Animais , Moléculas de Adesão Celular Neuronais/metabolismo , Cristalografia por Raios X , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Masculino , Modelos Moleculares , Moléculas de Adesão de Célula Nervosa/metabolismo , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To explore the efficacy of botulinum toxin type A (BTX-A) therapy in relieving anxiety and depression in patients with hemifacial spasm (HFS) and benign essential blepharospasm (BEB). PATIENTS AND METHOD: Ninety idiopathic HFS patients and 90 BEB patients were enrolled. The anxiety and depression status were evaluated by self-rating anxiety scale (SAS) and self-rating depression scale (SDS), respectively, before and after the injection of BTX-A. RESULTS: Before treatment, the SAS and SDS scores of HFS patients were 41.25±6.35 and 42.25±7.57, respectively. The SAS scores were 40.17±8.36 for males and 43.56±6.10 for females (P=0.031). The SDS scores were 40.25±6.46 for males and 45.48±7.31 for females (P=0.008). After treatment, the SAS and SDS scores were 30.12±4.35 and 30.58±4.89, respectively. There was a significant difference in the SAS and SDS scores before and after treatment. Before treatment, the SAS scores of male and female BEB patients were 56.45±8.75 and 60.89±9.11, respectively, and the SDS scores of male and female BEB patients were 57.90±7.93 and 60.12±8.35, respectively. After treatment, the SAS score was 38.17±3.67 and the SDS score was 38.12±4.15, with a significant difference in before and after treatment scores. CONCLUSION: In HFS and BEB, especially in female patients, there is an association with anxiety and depression. BTX-A can improve the symptoms of anxiety and depression.
RESUMO
Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) systems are prokaryotic adaptive immune systems against invading nucleic acids. CRISPR locus variability has been exploited in evolutionary and epidemiological studies of Mycobacterium tuberculosis, the causative agent of tuberculosis, for over 20 yr, yet the biological function of this type III-A system is largely unexplored. Here, using cell biology and biochemical, mutagenic, and RNA-seq approaches, we show it is active in invader defense and has features atypical of type III-A systems: mature CRISPR RNA (crRNA) in its crRNA-CRISPR/Cas protein complex are of uniform length (â¼71 nt) and appear not to be subject to 3'-end processing after Cas6 cleavage of repeat RNA 8 nt from its 3' end. crRNAs generated resemble mature crRNA in type I systems, having both 5' (8 nt) and 3' (28 nt) repeat tags. Cas6 cleavage of repeat RNA is ion dependent, and accurate cleavage depends on the presence of a 3' hairpin in the repeat RNA and the sequence of its stem base nucleotides. This study unveils further diversity among CRISPR/Cas systems and provides insight into the crRNA recognition mechanism in M. tuberculosis, providing a foundation for investigating the potential of a type III-A-based genome editing system.-Wei, W., Zhang, S., Fleming, J., Chen, Y., Li, Z., Fan, S., Liu, Y., Wang, W., Wang, T., Liu, Y., Ren, B., Wang, M., Jiao, J., Chen, Y., Zhou, Y., Zhou, Y., Gu, S., Zhang, X., Wan, L., Chen, T., Zhou, L., Chen, Y., Zhang, X.-E., Li, C., Zhang, H., Bi, L. Mycobacterium tuberculosis type III-A CRISPR/Cas system crRNA and its maturation have atypical features.
Assuntos
Sistemas CRISPR-Cas , Mycobacterium tuberculosis/metabolismo , RNA Bacteriano/genética , Edição de Genes , Mycobacterium tuberculosis/genética , Análise de Sequência de RNA/métodosRESUMO
Objective: This study aimed to screen gene mutations in Chinese patients with benign essential blepharospasm (BEB) to understand its etiology. Methods: Twenty BEB patients diagnosed by clinical manifestations between April 2015 and October 2015 were enrolled. All the cases were investigated by questionnaires about general conditions, social behavioral factors, environmental factors, psychological factors, genetic factors, and previous diseases. In each patient, a total of 151 genes related to movement disorders were analyzed by second-generation sequencing. Results: Two patients had a family history of BEB, and they had SYNE1 and Cdkn1A-interacting zinc finger protein 1 (CIZ1) mutation, respectively. We found the SYNE1 mutation in seven patients, the CIZ1 mutation in two patients, the CACNA1A mutation in two patients, the LRRK2 mutation in two patients, and the FUS mutation in two patients. The C10orf2, TPP1, SLC1A3, PNKD, EIF4G1, SETX, PRRT2, SPTBN2, and TTBK2 mutations were found in only one patient, respectively, while not any mutation in the 151 genes were found in two patients. Some patients had mutations in two genes. Conclusion: Genetic factors, especially SYNE1 and CIZ1 mutations, contribute to the etiology of BEB.