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1.
Biochem Soc Trans ; 52(3): 1293-1304, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38716884

RESUMO

ATP has recently been reconsidered as a molecule with functional properties which go beyond its recognized role of the energetic driver of the cell. ATP has been described as an allosteric modulator as well as a biological hydrotrope with anti-aggregation properties in the crowded cellular environment. The role of ATP as a modulator of the homeostasis of the neurotrophins (NTs), a growth factor protein family whose most known member is the nerve growth factor (NGF), has been investigated. The modulation of NTs by small endogenous ligands is still a scarcely described area, with few papers reporting on the topic, and very few reports on the molecular determinants of these interactions. However, a detailed atomistic description of the NTs interaction landscape is of urgent need, aiming at the identification of novel molecules as potential therapeutics and considering the wide range of potential pharmacological applications for NGF and its family members. This mini-review will focus on the unique cartography casting the interactions of the endogenous ligand ATP, in the interaction with NGF as well as with its precursor proNGF. These interactions revealed interesting features of the ATP binding and distinct differences in the binding mode between the highly structured mature NGF and its precursor, proNGF, which is characterized by an intrinsically unstructured domain. The overview on the recent available data will be presented, together with the future perspectives on the field.


Assuntos
Trifosfato de Adenosina , Fator de Crescimento Neural , Ligação Proteica , Fator de Crescimento Neural/metabolismo , Trifosfato de Adenosina/metabolismo , Humanos , Animais , Precursores de Proteínas/metabolismo , Fatores de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/química , Ligantes , Sítios de Ligação
2.
Exp Eye Res ; 238: 109743, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38056550

RESUMO

Pigment epithelium-derived factor (PEDF) is widely recognized as a neuroprotective factor expressed in the retina and has shown therapeutic potential in several retinal diseases. Our study aimed to identify the neuroprotective fragment in PEDF and investigate its protective activity in retinas under ischemia-reperfusion (IR) condition. We synthesized a series of shorter synthetic peptides, 6-mer (Ser93-Gln98) and its d-form variant (6 dS) derived from the 44-mer (Val78-Thr121; a PEDF neurotrophic fragment), to determine their cytoprotective activity in IR injury, which was induced in rat retinas by injection of saline into the anterior chamber to increase the intraocular pressure (IOP) followed by reperfusion. We found the cytoprotective effect of 6-mer on glutamate-treated Neuro-2a cells and tert-butyl hydroperoxide (tBHP)-treated 661W cells were 2.6-fold and 1.5-fold higher than the 44-mer, respectively. The cytoprotective effect was blocked by a chemical inhibitor atglistatin and blocking antibody targeting PEDF receptor (PEDF-R). IR induced several impairments in retina, including cell apoptosis, activation of microglia/macroglia, degeneration of retinal capillaries, reduction in electroretinography (ERG) amplitudes, and retinal atrophy. Such IR injuries were ameliorated by treatment with 6-mer and 6 dS eye drops. Also, the neuroprotective activity of 6-mer and 6 dS in ischemic retinas were dramatically reversed by atglistatin preconditioning. Taken together, our data demonstrate smallest neuroprotective fragment of PEDF has potential to treat retinal degeneration-related diseases.


Assuntos
Proteínas do Olho , Fatores de Crescimento Neural , Traumatismo por Reperfusão , Retina , Retinite , Serpinas , Animais , Ratos , Coelhos , Fatores de Crescimento Neural/administração & dosagem , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Proteínas do Olho/administração & dosagem , Proteínas do Olho/química , Proteínas do Olho/metabolismo , Serpinas/administração & dosagem , Serpinas/química , Serpinas/metabolismo , Retina/metabolismo , Retina/patologia , Traumatismo por Reperfusão/metabolismo , Citoproteção , Apoptose , Neurônios/metabolismo , Retinite/tratamento farmacológico , Retinite/metabolismo , Administração Tópica , Peptídeos/administração & dosagem , Peptídeos/metabolismo
3.
Nature ; 618(7967): 1065-1071, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37198476

RESUMO

Eukaryotic cells can undergo different forms of programmed cell death, many of which culminate in plasma membrane rupture as the defining terminal event1-7. Plasma membrane rupture was long thought to be driven by osmotic pressure, but it has recently been shown to be in many cases an active process, mediated by the protein ninjurin-18 (NINJ1). Here we resolve the structure of NINJ1 and the mechanism by which it ruptures membranes. Super-resolution microscopy reveals that NINJ1 clusters into structurally diverse assemblies in the membranes of dying cells, in particular large, filamentous assemblies with branched morphology. A cryo-electron microscopy structure of NINJ1 filaments shows a tightly packed fence-like array of transmembrane α-helices. Filament directionality and stability is defined by two amphipathic α-helices that interlink adjacent filament subunits. The NINJ1 filament features a hydrophilic side and a hydrophobic side, and molecular dynamics simulations show that it can stably cap membrane edges. The function of the resulting supramolecular arrangement was validated by site-directed mutagenesis. Our data thus suggest that, during lytic cell death, the extracellular α-helices of NINJ1 insert into the plasma membrane to polymerize NINJ1 monomers into amphipathic filaments that rupture the plasma membrane. The membrane protein NINJ1 is therefore an interactive component of the eukaryotic cell membrane that functions as an in-built breaking point in response to activation of cell death.


Assuntos
Moléculas de Adesão Celular Neuronais , Morte Celular , Membrana Celular , Fatores de Crescimento Neural , Animais , Humanos , Camundongos , Moléculas de Adesão Celular Neuronais/química , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Moléculas de Adesão Celular Neuronais/ultraestrutura , Membrana Celular/metabolismo , Membrana Celular/patologia , Membrana Celular/ultraestrutura , Microscopia Crioeletrônica , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/ultraestrutura , Mutagênese Sítio-Dirigida , Biopolímeros/química , Biopolímeros/genética , Biopolímeros/metabolismo
4.
Ageing Res Rev ; 82: 101763, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36272696

RESUMO

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a novel evolutionarily conserved protein present in both vertebrate and invertebrate species. MANF shows distinct structural and functional properties than the traditional neurotrophic factors (NTF). MANF is composed of an N-terminal saposin-like lipid-binding domain and a C-terminal SAF-A/B, Acinus and PIAS (SAP) domain connected by a short linker. The two well-described activities of MANF include (1) role as a neurotrophic factor that plays direct neuroprotective effects in the nervous system and (2) cell protective effects in the animal models of non-neuronal diseases, including retinal damage, diabetes mellitus, liver injury, myocardial infarction, nephrotic syndrome, etc. The main objective of the current review is to provide up-to-date insights regarding the structure of MANF, mechanisms regulating its expression and secretion, physiological functions in various tissues and organs, protective effects during aging, and potential clinical applications. Together, this review highlights the importance of MANF in reversing age-related dysfunction and geroprotection.


Assuntos
Astrócitos , Fármacos Neuroprotetores , Animais , Humanos , Astrócitos/metabolismo , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/uso terapêutico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Estresse do Retículo Endoplasmático
5.
J Biol Chem ; 298(9): 102272, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35850303

RESUMO

The axon initial segment (AIS) has characteristically dense clustering of voltage-gated sodium channels (Nav), cell adhesion molecule Neurofascin 186 (Nfasc), and neuronal scaffold protein Ankyrin-G (AnkG) in neurons, which facilitates generation of an action potential and maintenance of axonal polarity. However, the mechanisms underlying AIS assembly, maintenance, and plasticity remain poorly understood. Here, we report the high-resolution crystal structure of the AnkG ankyrin repeat (ANK repeat) domain in complex with its binding site in the Nfasc cytoplasmic tail that shows, in conjunction with binding affinity assays with serial truncation variants, the molecular basis of AnkG-Nfasc binding. We confirm AnkG interacts with the FIGQY motif in Nfasc, and we identify another region required for their high affinity binding. Our structural analysis revealed that ANK repeats form 4 hydrophobic or hydrophilic layers in the AnkG inner groove that coordinate interactions with essential Nfasc residues, including F1202, E1204, and Y1212. Moreover, we show disruption of the AnkG-Nfasc complex abolishes Nfasc enrichment at the AIS in cultured mouse hippocampal neurons. Finally, our structural and biochemical analysis indicated that L1 syndrome-associated mutations in L1CAM, a member of the L1 immunoglobulin family proteins including Nfasc, L1CAM, NrCAM, and CHL1, compromise binding with ankyrins. Taken together, these results define the mechanisms underlying AnkG-Nfasc complex formation and show that AnkG-dependent clustering of Nfasc is required for AIS integrity.


Assuntos
Repetição de Anquirina , Anquirinas , Segmento Inicial do Axônio , Moléculas de Adesão Celular , Fatores de Crescimento Neural , Animais , Anquirinas/química , Segmento Inicial do Axônio/química , Sítios de Ligação , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Cristalografia por Raios X , Camundongos , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/genética , Molécula L1 de Adesão de Célula Nervosa/genética , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Domínios Proteicos
6.
Yakugaku Zasshi ; 142(3): 241-277, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-35228379

RESUMO

Neurotrophic factors have been shown to potentially be beneficial for the treatment of neurodegenerative diseases such as Alzheimer's disease, because endogenous neurotrophic factors (NGF, BDNF) have been recognized to play critical roles in the promotion of neurogenesis, differentiation, and neuroprotection throughout the development of the central nervous system. However, high-molecular-weight proteins are unable to cross the blood-brain barrier and are easily decomposed under physiological conditions. Thus, small molecules that can mimic the functions of neurotrophic factors are promising alternatives for the treatment of neurodegenerative disease. Since 1990, the author has been involved in searching for natural products with typical neurotrophic properties that can cause neurogenesis, enhance neurite outgrowth, and protect against neuronal death by using three cellular systems (PC12, rat cortical neurons, and MEB5 cells). Through these research activities on neurotrophic natural products, the author has tried to induce a paradigm shift from the discipline of natural products chemistry to science disciplines. This review focuses on our independent synthetic studies of the neurotrophic natural products discovered in the plants. The following synthetic elaborations are described: syntheses of dimeric isocuparane-type sesquiterpenes mastigophorenes A and B, macrocyclic bis-bibenzyls plagiochins A-D and cavicularin through a Pd-catalyzed Stille-Kelly reaction; the formal synthesis of merrilactone A and jiadifenin, which are seco-prezizaane-type sesquiterpenes, through intramolecular Pd-catalyzed Mizoroki-Heck and Tsuji-Trost reactions; and finally the first enantioselective synthesis of neovibsanin B, a vibsane-type diterpene, through a Pd-catalyzed cyclic carbopalladation-carbonyl tandem reaction.


Assuntos
Produtos Biológicos/síntese química , Fatores de Crescimento Neural/síntese química , Animais , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Barreira Hematoencefálica/metabolismo , Hidrocarbonetos Aromáticos com Pontes/síntese química , Ciclopentanos/síntese química , Diterpenos/síntese química , Lactonas/síntese química , Camundongos , Peso Molecular , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/farmacologia , Fatores de Crescimento Neural/uso terapêutico , Doenças Neurodegenerativas/tratamento farmacológico , Fenômenos de Química Orgânica , Ratos , Sesquiterpenos/síntese química , Estereoisomerismo
7.
Bioorg Med Chem Lett ; 60: 128580, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35066142

RESUMO

Majucin-type Illicium sesquiterpenes with potent neurotrophic activity are considered to be promising candidates for the treatment of various neurodegenerative disease. Owing to the low-abundance metabolites in Illicium genus, there are few studies on their structural modifications, structure-activity relationships, and pharmacophoric motif. Herein, structural modifications were conducted on the hydroxyl groups at C-3 and C-6 positions of two majucin-type compounds neomajucin (1) and majucin (2), and 39 neomajucin/majucin based esters were synthesized and evaluated for their neurite outgrowth-promoting activities. Among all the target derivatives, compounds 1a, 1j, 1r, 2b, 2d, 3a, 3b, 3d and 3h displayed more potent neurite outgrowth-promoting activity than their precursors. Some interesting structure-activity relationships (SARs) were also observed. Moreover, compound 1a showed good neuroprotective effect on MPP+-induced PC12 cell damage. Finally, compounds 1a and 3a exhibited relatively no cytotoxicity to normal human H9C2 cardiac cells. This work will shed light on the development of neomajucin/majucin derivatives as potential neurotrophic agents.


Assuntos
Fatores de Crescimento Neural/farmacologia , Doenças Neurodegenerativas/tratamento farmacológico , Crescimento Neuronal/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Relação Dose-Resposta a Droga , Humanos , Illicium/química , Estrutura Molecular , Fatores de Crescimento Neural/síntese química , Fatores de Crescimento Neural/química , Doenças Neurodegenerativas/metabolismo , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Células PC12 , Ratos , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade
8.
Mol Ther ; 29(9): 2821-2840, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33940158

RESUMO

A molecular hallmark in Parkinson's disease (PD) pathogenesis are α-synuclein aggregates. Cerebral dopamine neurotrophic factor (CDNF) is an atypical growth factor that is mostly resident in the endoplasmic reticulum but exerts its effects both intracellularly and extracellularly. One of the beneficial effects of CDNF can be protecting neurons from the toxic effects of α-synuclein. Here, we investigated the effects of CDNF on α-synuclein aggregation in vitro and in vivo. We found that CDNF directly interacts with α-synuclein with a KD = 23 ± 6 nM and reduces its auto-association. Using nuclear magnetic resonance (NMR) spectroscopy, we identified interaction sites on the CDNF protein. Remarkably, CDNF reduces the neuronal internalization of α-synuclein fibrils and induces the formation of insoluble phosphorylated α-synuclein inclusions. Intra-striatal CDNF administration alleviates motor deficits in rodents challenged with α-synuclein fibrils, though it did not reduce the number of phosphorylated α-synuclein inclusions in the substantia nigra. CDNF's beneficial effects on rodent behavior appear not to be related to the number of inclusions formed in the current context, and further study of its effects on the aggregation mechanism in vivo are needed. Nonetheless, the interaction of CDNF with α-synuclein, modifying its aggregation, spreading, and associated behavioral alterations, provides novel insights into the potential of CDNF as a therapeutic strategy in PD and other synucleinopathies.


Assuntos
Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Doença de Parkinson/fisiopatologia , Substância Negra/metabolismo , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Modelos Animais de Doenças , Dopamina/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Modelos Moleculares , Doença de Parkinson/metabolismo , Fosforilação , Cultura Primária de Células , Agregados Proteicos , Ligação Proteica , Conformação Proteica , Ratos
9.
Proc Natl Acad Sci U S A ; 118(18)2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33903230

RESUMO

Neuropeptides and neurotrophic factors secreted from dense core vesicles (DCVs) control many brain functions, but the calcium sensors that trigger their secretion remain unknown. Here, we show that in mouse hippocampal neurons, DCV fusion is strongly and equally reduced in synaptotagmin-1 (Syt1)- or Syt7-deficient neurons, but combined Syt1/Syt7 deficiency did not reduce fusion further. Cross-rescue, expression of Syt1 in Syt7-deficient neurons, or vice versa, completely restored fusion. Hence, both sensors are rate limiting, operating in a single pathway. Overexpression of either sensor in wild-type neurons confirmed this and increased fusion. Syt1 traveled with DCVs and was present on fusing DCVs, but Syt7 supported fusion largely from other locations. Finally, the duration of single DCV fusion events was reduced in Syt1-deficient but not Syt7-deficient neurons. In conclusion, two functionally redundant calcium sensors drive neuromodulator secretion in an expression-dependent manner. In addition, Syt1 has a unique role in regulating fusion pore duration.


Assuntos
Encéfalo/metabolismo , Neurônios/metabolismo , Neurotransmissores/química , Sinaptotagmina I/genética , Sinaptotagminas/genética , Animais , Cálcio/química , Cálcio/metabolismo , Vesículas de Núcleo Denso/genética , Vesículas de Núcleo Denso/metabolismo , Regulação da Expressão Gênica/genética , Hipocampo/metabolismo , Humanos , Camundongos , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Neurônios/patologia , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo
10.
Nature ; 591(7848): 131-136, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33472215

RESUMO

Plasma membrane rupture (PMR) is the final cataclysmic event in lytic cell death. PMR releases intracellular molecules known as damage-associated molecular patterns (DAMPs) that propagate the inflammatory response1-3. The underlying mechanism of PMR, however, is unknown. Here we show that the cell-surface NINJ1 protein4-8, which contains two transmembrane regions, has an essential role in the induction of PMR. A forward-genetic screen of randomly mutagenized mice linked NINJ1 to PMR. Ninj1-/- macrophages exhibited impaired PMR in response to diverse inducers of pyroptotic, necrotic and apoptotic cell death, and were unable to release numerous intracellular proteins including HMGB1 (a known DAMP) and LDH (a standard measure of PMR). Ninj1-/- macrophages died, but with a distinctive and persistent ballooned morphology, attributable to defective disintegration of bubble-like herniations. Ninj1-/- mice were more susceptible than wild-type mice to infection with Citrobacter rodentium, which suggests a role for PMR in anti-bacterial host defence. Mechanistically, NINJ1 used an evolutionarily conserved extracellular domain for oligomerization and subsequent PMR. The discovery of NINJ1 as a mediator of PMR overturns the long-held idea that cell death-related PMR is a passive event.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Morte Celular , Membrana Celular/metabolismo , Fatores de Crescimento Neural/metabolismo , Animais , Apoptose , Moléculas de Adesão Celular Neuronais/química , Moléculas de Adesão Celular Neuronais/genética , Morte Celular/genética , Feminino , Humanos , Macrófagos , Masculino , Camundongos , Mutação , Necrose , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/genética , Multimerização Proteica , Piroptose/genética
11.
Drug Des Devel Ther ; 14: 5393-5403, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33304094

RESUMO

INTRODUCTION: Carbamoylated erythropoietin (CEPO) is a chemically engineered, nonhematopoietic derivative of erythropoietin (EPO) that retains its antidepressant and pro-cognitive effects, which are attributed to the increased expression of neurotrophic factors like brain derived neurotrophic factor (BDNF), in the central nervous system. However, the chemical modification process which produces CEPO from erythropoietin (EPO) requires pure EPO as raw material, is challenging to scale-up and can also cause batch-to-batch variability. To address these key limitations while retaining its behavioral effects, we designed, expressed and analyzed a triple, glutamine, substitution recombinant mimetic of CEPO, named QPO. METHODS AND MATERIALS: We employ a combination of computational structural biology, molecular, cellular and behavioral assays to design, produce, purify and test QPO. RESULTS: QPO was shown to be a nonhematopoietic polypeptide with significant antidepressant-like and pro-cognitive behavioral effects in rodent assays while significantly upregulating BDNF expression in-vitro and in-vivo. The in-silico binding affinity analysis of QPO bound to the EPOR/EPOR homodimer receptor shows significantly decreased binding to Active Site 2, but not Active Site 1, of EPOR. DISCUSSION: The results of the behavioral and gene expression analysis imply that QPO is a successful CEPO mimetic protein and potentially acts via a similar neurotrophic mechanism, making it a drug development target for psychiatric disorders. The decreased binding to Active Site 2 could imply that this active site is not involved in neuroactive signaling and could allow the development of a functional innate repair receptor (IRR) model. Substituting the three glutamine substitution residues with arginine (RPO) resulted in the loss of behavioral activity, indicating the importance of glutamine residues at those positions.


Assuntos
Antidepressivos/uso terapêutico , Desenvolvimento de Medicamentos , Transtornos Mentais/tratamento farmacológico , Fatores de Crescimento Neural/uso terapêutico , Animais , Antidepressivos/química , Antidepressivos/isolamento & purificação , Linhagem Celular Tumoral , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/isolamento & purificação , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
12.
Org Lett ; 22(19): 7676-7680, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-32955264

RESUMO

Meloyunnanines A-C, three alkaloids with an unprecedented skeleton, were isolated from fruits of Melodinus yunnanensis. The structures featuring a caged-6/6/5/6/5/5 ring system were elucidated by the analysis of comprehensive spectroscopic and X-ray data. Biosynthetically, meloyunnanines A-C were assigned to monoterpenoid quinoline alkaloids (MQAs), derived from monoterpenoid indole alkaloids through oxidation and rearrangement. These compounds together with three known Melodinus MQAs were evaluated for their neurotrophic activity and scandine N4-oxide exhibited significant effect.


Assuntos
Apocynaceae/química , Monoterpenos/farmacologia , Fatores de Crescimento Neural/farmacologia , Alcaloides de Triptamina e Secologanina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Frutas , Humanos , Estrutura Molecular , Monoterpenos/química , Monoterpenos/isolamento & purificação , Fatores de Crescimento Neural/química , Neuritos , Quinolinas/química , Alcaloides de Triptamina e Secologanina/química , Alcaloides de Triptamina e Secologanina/isolamento & purificação
13.
Proc Natl Acad Sci U S A ; 117(21): 11450-11458, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32385162

RESUMO

Dynamic remodeling of the extracellular matrix affects many cellular processes, either directly or indirectly, through the regulation of soluble ligands; however, the mechanistic details of this process remain largely unknown. Here we propose that type I collagen remodeling regulates the receptor-binding activity of pigment epithelium-derived factor (PEDF), a widely expressed secreted glycoprotein that has multiple important biological functions in tissue and organ homeostasis. We determined the crystal structure of PEDF in complex with a disulfide cross-linked heterotrimeric collagen peptide, in which the α(I) chain segments-each containing the respective PEDF-binding region (residues 930 to 938)-are assembled with an α2α1α1 staggered configuration. The complex structure revealed that PEDF specifically interacts with a unique amphiphilic sequence, KGHRGFSGL, of the type I collagen α1 chain, with its proposed receptor-binding sites buried extensively. Molecular docking demonstrated that the PEDF-binding surface of type I collagen contains the cross-link-susceptible Lys930 residue of the α1 chain and provides a good foothold for stable docking with the α1(I) N-telopeptide of an adjacent triple helix in the fibril. Therefore, the binding surface is completely inaccessible if intermolecular crosslinking between two crosslink-susceptible lysyl residues, Lys9 in the N-telopeptide and Lys930, is present. These structural analyses demonstrate that PEDF molecules, once sequestered around newly synthesized pericellular collagen fibrils, are gradually liberated as collagen crosslinking increases, making them accessible for interaction with their target cell surface receptors in a spatiotemporally regulated manner.


Assuntos
Colágeno Tipo I/metabolismo , Proteínas do Olho/química , Proteínas do Olho/metabolismo , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Serpinas/química , Serpinas/metabolismo , Sítios de Ligação , Dicroísmo Circular , Colágeno Tipo I/química , Cristalografia por Raios X , Dissulfetos/química , Lisina/química , Simulação de Acoplamento Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Conformação Proteica , Transdução de Sinais , Análise Espaço-Temporal
14.
J Mol Neurosci ; 70(8): 1293-1302, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32458204

RESUMO

TLQP62 is a neuropeptide derived from the neurotrophin-inducible VGF (non-acronymic) protein with antidepressant-like properties capable of inducing increased memory on the mouse hippocampus by promoting neurogenesis and synaptic plasticity through brain-derived neurotropic factor (BDNF) and its receptor tyrosine receptor kinase B (TrkB). Human SH-SY5Y neuroblastoma-derived cell line is widely used in neuroscience research and is known to undergo neurodifferentiation in the presence of all-trans retinoic acid by upregulating the expression of TrkB, making cells responsive to BDNF. As TLQP62 promotes BDNF expression, which in turn activates a BDNF/TrkB/CREB (cAMP response element-binding protein) pathway that upregulates VGF expression, there is a VGF-BDNF regulatory loop that seems to regulate neurogenesis. Therefore, here, we evaluate by morphological observation the ability of human TLQP62 to induce neuritogenesis of human SH-SY5Y neuroblastoma-derived cell line in a retinoic acid and BDFN-like way, making this cell line a suitable cell model for further studies concerning TLQP62 molecular mechanisms and signalling pathways. SIGNIFICANCE STATEMENT: VGF has been widely explored for its role in emotional behaviour and neuropsychiatric illness (Bartolomucci et al. 2011). Although VGF levels were found reduced in leukocytes of depressed patients, after antidepressant treatment or voluntary exercise, those levels were found to be restored in the hippocampus (Hunsberger et al. 2007; Thakker-Varia et al. 2007). Administration to hippocampal cells of TLQP62 produced an increase in synaptic charge that could explain this antidepressants effects (Alder et al. 2003). This interesting role of TLQP62 in the brain, especially in the hippocampus, makes this neuropeptide an attractive target for further investigation of its role in neurogenesis, learning, memory, and neurological disorders, and possible treatment development. Thus, the identification of a receptor(s) for this peptide and associated signalling pathway(s) is of high importance, as well as a proper cell model to perform those studies.


Assuntos
Crescimento Neuronal/efeitos dos fármacos , Peptídeos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Humanos , Glicoproteínas de Membrana/metabolismo , Fatores de Crescimento Neural/química , Peptídeos/química , Receptor trkB/metabolismo , Transdução de Sinais
15.
J Mol Biol ; 432(13): 3749-3760, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32302608

RESUMO

Optically controlled receptor tyrosine kinases (opto-RTKs) allow regulation of RTK signaling using light. Until recently, the majority of opto-RTKs were activated with blue-green light. Fusing a photosensory core module of Deinococcus radiodurans bacterial phytochrome (DrBphP-PCM) to the kinase domains of neurotrophin receptors resulted in opto-RTKs controlled with light above 650 nm. To expand this engineering approach to RTKs of other families, here we combined the DrBpP-PCM with the cytoplasmic domains of EGFR and FGFR1. The resultant Dr-EGFR and Dr-FGFR1 opto-RTKs are rapidly activated with near-infrared and inactivated with far-red light. The opto-RTKs efficiently trigger ERK1/2, PI3K/Akt, and PLCγ signaling. Absence of spectral crosstalk between the opto-RTKs and green fluorescent protein-based biosensors enables simultaneous Dr-FGFR1 activation and detection of calcium transients. Action mechanism of the DrBphP-PCM-based opto-RTKs is considered using the available RTK structures. DrBphP-PCM represents a versatile scaffold for engineering of opto-RTKs that are reversibly regulated with far-red and near-infrared light.


Assuntos
Fitocromo/ultraestrutura , Receptores Proteína Tirosina Quinases/ultraestrutura , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Técnicas Biossensoriais , Deinococcus/química , Deinococcus/genética , Proteínas de Fluorescência Verde/química , Células HeLa , Humanos , Luz , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/genética , Fosfatidilinositol 3-Quinases/genética , Fitocromo/química , Fitocromo/genética , Conformação Proteica/efeitos da radiação , Proteínas Proto-Oncogênicas c-akt/genética , Receptores Proteína Tirosina Quinases/química , Receptores Proteína Tirosina Quinases/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/química , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptores de Fator de Crescimento Neural/química , Receptores de Fator de Crescimento Neural/genética , Transdução de Sinais/efeitos da radiação
17.
ACS Appl Mater Interfaces ; 12(14): 16168-16177, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32182427

RESUMO

Peripheral nerve injury (PNI) was the leading cause of permanent dysfunction in movement and sensation. Synthesized nerve guide conduits (NGCs) with Schwann Cells (SCs) can help peripheral nerve regeneration. However, poor accessibility of SCs and lack of full coverage of seeded cells on NGCs can lead to failure of nerve regeneration across long gaps and full functional recovery. To overcome these limitations, bone marrow stromal cells (BMSCs) and a novel culture method were proposed in the current study. BMSCs were harvested and seeded on a never growth factor (NGF)-loaded PCL nanofibrous NGCs and cultured with a rotary cell culture system (RCCS) before implantation. The NGCs were tested in vitro with PC-12 cells to validate the bioactivity of released NGF and to access its ability to promote neurite extension. Also, the NGCs were tested in vivo with rat sciatic nerve model to exam its potential in bridging the long gap (15 mm segmental defect). The efficacy of the NGCs was investigated based on the results of the functional test, electrophysiology test, muscle atrophy, and histological analysis. The results of in vitro PC-12 cell study confirmed the bioactivity of released NGF and showed a significant increase in the neurite extension with the help of PEG-diamine and BSA. These results showed that the novel loading method could preserve the bioactivity of growth factors and achieve a sustained release in vitro. Besides, the results of the in vivo study exhibited a significant increase with the combination of all additives. These results showed that with the help of NGF and RCCS, the NGCs with the seeded BMSCs could enhance peripheral nerve regeneration across long nerve injury gaps.


Assuntos
Nanofibras/química , Regeneração Nervosa/efeitos dos fármacos , Traumatismos dos Nervos Periféricos/terapia , Nervo Isquiático/efeitos dos fármacos , Animais , Reatores Biológicos , Técnicas de Cultura de Células , Modelos Animais de Doenças , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Nanofibras/uso terapêutico , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Células PC12 , Traumatismos dos Nervos Periféricos/patologia , Nervos Periféricos/efeitos dos fármacos , Nervos Periféricos/crescimento & desenvolvimento , Nervos Periféricos/patologia , Ratos , Células de Schwann/efeitos dos fármacos , Nervo Isquiático/crescimento & desenvolvimento , Nervo Isquiático/patologia
18.
Biomed Mater ; 15(3): 035020, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32079004

RESUMO

Spinal cord injury is a devastating trauma with high mortality and disability, for which there is no effective treatment. Stem cell-based tissue engineering has been reported to promote functional neural recovery. At present, building a neural scaffold with excellent biocompatibility for cells and tissues is still challenging. In this study, a new thermosensitive composite hydrogel based on chitosan, hydroxyethyl cellulose, collagen and ß-phosphoglycerate (CS-HEC-Col/GP hydrogel) is developed to encapsulate murine bone marrow-derived mesenchymal stem cells (BMSCs) to improve therapeutic efficacy in spinal cord injured mice. This composite hydrogel possesses a good cytocompatibility to mouse BMSCs by live/dead staining, minimized inflammatory reaction in vivo by hematoxylin and eosin staining and suitable rheological behavior similar to neural tissue, ranging from 100 to 1000 Pa. Furthermore, the data from animal experiments indicated that BMSC-loaded CS-HEC-Col/GP hydrogel could enhance the survival or proliferation of endogenous nerve cells, probably by secreting neurotrophic factors and inhibiting apoptosis, and thereby promote the recovery of motor function in the hindlimbs of a murine spinal cord injury model.


Assuntos
Células da Medula Óssea/citologia , Quitosana/química , Hidrogéis/química , Células-Tronco Mesenquimais/citologia , Traumatismos da Medula Espinal/metabolismo , Engenharia Tecidual/métodos , Animais , Apoptose , Materiais Biocompatíveis , Temperatura Corporal , Celulose/análogos & derivados , Celulose/química , Meios de Cultura , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Destreza Motora , Fatores de Crescimento Neural/química , Neurônios/metabolismo , Pressão , Reologia/métodos , Traumatismos da Medula Espinal/terapia
19.
Mol Neurobiol ; 57(4): 1799-1813, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31838721

RESUMO

Neuregulin 2 (NRG2) belongs to the EGF family of growth factors. Most of this family members require proteolytic cleavage to liberate their ectodomains capable of binding and activating their cognate ErbB receptors. To date, most of the studies investigating proteolytic processing of neuregulins focused on NRG1, which was shown to undergo ectodomain shedding by several ADAM proteases and BACE1 and the remaining fragment was further cleaved by γ-secretase. Recently, NRG2 attracted more attention due to its role in the neurogenesis and modulation of behaviors associated with psychiatric disorders. In this study, we used genetic engineering methods to identify proteases involved in proteolytic processing of murine NRG2. Using non-neuronal cell lines as well as cultures of primary hippocampal neurons, we demonstrated that the major proteases responsible for releasing NRG2 ectodomain are ADAM10 and BACE2. Co-expression of NRG2 and BACE2 in neurons of certain brain structures including medulla oblongata and cerebellar deep nuclei was confirmed via immunohistochemical staining. The cleavage of NRG2 by ADAM10 or BACE2 generates a C-terminal fragment that serves as a substrate for γ-secretase. We also showed that murine NRG2 is subject to post-translational modifications, substantial glycosylation of its extracellular part, and phosphorylation of the cytoplasmic tail.


Assuntos
Fatores de Crescimento Neural/metabolismo , Processamento de Proteína Pós-Traducional , Proteína ADAM10/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Linhagem Celular Tumoral , Glicosilação , Camundongos Endogâmicos C57BL , Fatores de Crescimento Neural/química , Fases de Leitura Aberta/genética , Domínios Proteicos , Especificidade por Substrato
20.
Biomed Res Int ; 2019: 5320902, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31886225

RESUMO

Pregnancy is a period in a woman's life in which changes can occur that affect different physiological processes. Common conditions during this period include vascular changes, such as lower extremity venous insufficiency (VI). This is an observational, analytical, and prospective cohort study in which 114 pregnant women were analyzed, of which 62 were clinically diagnosed with VI. In parallel, 52 control patients without VI (HC) were studied. The aim of this study was to observe changes in angiogenesis and inflammation markers as well as the presence of calcium deposits. The expression of vascular endothelial growth factor (VEGF), transforming growth factor-ß (TGF-ß), and pigment epithelium-derived factor (PEDF) was analyzed by immunohistochemistry and RT-qPCR. The presence of calcium deposits was revealed using the von Kossa method. In the placentas of mothers with VI, gene expression of VEGF (34.575 [32.380-36.720] VI vs 32.965 [30.580-36.320] HC) and PEDF (25.417 [24.459-27.675] VI vs 24.400 [23.102-30.223] HC) significantly increased, as was protein expression in the placental villi. An increase in calcium deposits was observed in the placentas of women with VI (72.58% VI/53.84% HC). This study revealed the existence of cellular damage in the placental villi of mothers with VI with tissue implications such as increased calcification.


Assuntos
Calcinose/metabolismo , Proteínas do Olho/análise , Fatores de Crescimento Neural/análise , Placenta , Complicações Cardiovasculares na Gravidez/metabolismo , Serpinas/análise , Fator A de Crescimento do Endotélio Vascular/análise , Insuficiência Venosa/metabolismo , Adolescente , Adulto , Calcinose/fisiopatologia , Proteínas do Olho/química , Proteínas do Olho/metabolismo , Feminino , Humanos , Extremidade Inferior/fisiopatologia , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/metabolismo , Placenta/irrigação sanguínea , Placenta/química , Placenta/patologia , Gravidez , Complicações Cardiovasculares na Gravidez/fisiopatologia , Estudos Prospectivos , Serpinas/química , Serpinas/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/química , Fator A de Crescimento do Endotélio Vascular/metabolismo , Insuficiência Venosa/fisiopatologia , Adulto Jovem
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