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1.
FASEB J ; 38(1): e23312, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38161282

RESUMEN

ProBDNF is the precursor protein of brain-derived neurotrophic factor (BDNF) expressed in the central nervous system and peripheral tissues. Previous studies showed that the blood levels of both proBDNF and p75 neurotrophic receptors (p75NTR) in major depressive disorder (MDD) were increased, but which blood cell types express proBDNF and its receptors is not known. Furthermore, the relationship between proBDNF/p75NTR and inflammatory cytokines in peripheral blood of MDD is unclear. Peripheral blood mononuclear cells (PBMCs) and serum were obtained from depressive patients (n = 32) and normal donors (n = 20). We examined the expression of proBDNF and inflammatory markers and their correlative relationship in patients with major depression. Using flow cytometry analysis, we examined which blood cells express proBDNF and its receptors. Finally, the role of proBDNF/p75NTR signal in inflammatory immune activity of PBMCs was verified in vitro experiments. Inflammatory cytokines in PBMC from MDD patients were increased and correlated with the major depression scores. The levels of IL-1ß and IL-10 were also positively correlated with the major depression scores, while the levels of TNF-α and IL-6 were negatively correlated with the major depression scores. Intriguingly, the levels of sortilin were positively correlated with IL-1ß. Q-PCR and Western blots showed proBDNF, p75NTR, and sortilin levels were significantly increased in PBMCs from MDD patients compared with that from the normal donors. Flow cytometry studies showed that proBDNF and p75NTR were present mainly in CD4+ and CD8+ T cells. The number of proBDNF and p75NTR positive CD4+ and CD8+ T cells from MDD patients was increased and subsequently reversed after therapeutic management. Exogenous proBDNF protein or p75ECD-Fc treatment of cultured PBMC affected the release of inflammatory cytokines in vitro. ProBDNF promoted the expression of inflammatory cytokines, while p75ECD-Fc inhibited the expression of inflammatory cytokines. Given there was an inflammatory response of lymphocytes to proBDNF, it is suggested that proBDNF/p75NTR signaling may upstream inflammatory cytokines in MDD. Our data suggest that proBDNF/p75NTR signaling may not only serve as biomarkers but also may be a potential therapeutic target for MDD.


Asunto(s)
Trastorno Depresivo Mayor , Humanos , Trastorno Depresivo Mayor/metabolismo , Leucocitos Mononucleares/metabolismo , Receptores de Factor de Crecimiento Nervioso/genética , Receptores de Factor de Crecimiento Nervioso/metabolismo , Regulación hacia Arriba , Linfocitos T CD8-positivos/metabolismo , Depresión , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Citocinas/metabolismo
2.
Mol Psychiatry ; 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-38001337

RESUMEN

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with a complex pathogenesis. Senile plaques composed of the amyloid-ß (Aß) peptide in the brain are the core hallmarks of AD and a promising target for the development of disease-modifying therapies. However, over the past 20 years, the failures of clinical trials directed at Aß clearance have fueled a debate as to whether Aß is the principal pathogenic factor in AD and a valid therapeutic target. The success of the recent phase 3 trials of lecanemab (Clarity AD) and donanemab (Trailblazer Alz2), and lessons from previous Aß clearance trials provide critical evidence to support the role of Aß in AD pathogenesis and suggest that targeting Aß clearance is heading in the right direction for AD treatment. Here, we analyze key questions relating to the efficacy of Aß targeting therapies, and provide perspectives on early intervention, adequate Aß removal, sufficient treatment period, and combinatory therapeutics, which may be required to achieve the best cognitive benefits in future trials in the real world.

3.
FASEB J ; 36(3): e22180, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35129860

RESUMEN

P75 pan-neurotrophin receptor (p75NTR) is an important receptor for the role of neurotrophins in survival and death of neurons during development and after nerve injury. Our previous research found that the precursor of brain-derived neurotrophic factor (proBDNF) regulates pain as an inflammatory mediator. The current understanding of the role of proBDNF/p75NTR signaling pathway in inflammatory arthritis pain and rheumatoid arthritis (RA) is unclear. We recruited 20 RA patients, 20 healthy donors (HDs), and 10 osteoarthritis (OA) patients. Hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) of proBDNF and p75NTR in synovial membrane were performed and evaluated. We next examined the mRNA and protein expression of proBDNF/p75NTR signaling pathway in peripheral blood mononuclear cells (PBMCs) and synovial tissue. ELISA and flow cytometry were assessed between the blood of RA patients and HD. To induce RA, collagen-induced arthritis (CIA) were induced in mice. We found over-synovitis of RA synovial membrane compared to OA controls in histologic sections. P75NTR and sortilin mRNA, and proBDNF protein level were significantly increased in PBMCs of RA patients compared with the HD. Consistently, ELISA showed that p75NTR, sortilin, tumor necrosis factor α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and interleukin-10 (IL-10) levels in the serum of RA patients were increased compared with HD and p75NTR, sortilin were positively correlated with Disease Activity Score in 28 joints (DAS28). In addition, using flow cytometry we showed that the increased levels of proBDNF and p75NTR characterized in CD4+ and CD8+ T cells of RA patients were subsequently reversed with methotrexate (MTX) treatment. Furthermore, we found pathological changes, inflammatory pain, upregulation of the mRNA and protein expression of proBDNF/p75NTR signaling pathway, and upregulation of inflammatory cytokines in spinal cord using a well-established CIA mouse model. We showed intravenous treatment of recombinant p75ECD-Fc that biologically blocked all inflammatory responses and relieved inflammatory pain of animals with CIA. Our findings showed the involvement of proBDNF/p75NTR pathway in the RA inflammatory response and how blocking it with p75ECD-Fc may be a promising therapeutic treatment for RA.


Asunto(s)
Artritis Reumatoide/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Interleucinas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Receptores de Factor de Crecimiento Nervioso/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Adulto , Animales , Femenino , Humanos , Interleucinas/sangre , Leucocitos Mononucleares/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Precursores de Proteínas/metabolismo , Membrana Sinovial/metabolismo , Linfocitos T/metabolismo , Factor de Necrosis Tumoral alfa/sangre
4.
Int J Mol Sci ; 24(12)2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37373499

RESUMEN

Anxiety and depressive disorders are closely associated; however, the pathophysiology of these disorders remains poorly understood. Further exploration of the mechanisms involved in anxiety and depression such as the stress response may provide new knowledge that will contribute to our understanding of these disorders. Fifty-eight 8-12-week-old C57BL6 mice were separated into experimental groups by sex as follows: male controls (n = 14), male restraint stress (n = 14), female controls (n = 15) and female restraint stress (n = 15). These mice were taken through a 4-week randomised chronic restraint stress protocol, and their behaviour, as well as tryptophan metabolism and synaptic proteins, were measured in the prefrontal cortex and hippocampus. Adrenal catecholamine regulation was also measured. The female mice showed greater anxiety-like behaviour than their male counterparts. Tryptophan metabolism was unaffected by stress, but some basal sex characteristics were noted. Synaptic proteins were reduced in the hippocampus in stressed females but increased in the prefrontal cortex of all female mice. These changes were not found in any males. Finally, the stressed female mice showed increased catecholamine biosynthesis capability, but this effect was not found in males. Future studies in animal models should consider these sex differences when evaluating mechanisms related to chronic stress and depression.


Asunto(s)
Neuroquímica , Ratones , Femenino , Animales , Masculino , Triptófano/metabolismo , Ratones Endogámicos C57BL , Corteza Prefrontal/metabolismo , Ansiedad/metabolismo , Hipocampo/metabolismo , Depresión/etiología , Depresión/metabolismo , Conducta Animal , Catecolaminas/metabolismo , Estrés Psicológico/metabolismo , Restricción Física
5.
Eur J Neurosci ; 56(8): 5299-5318, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36017737

RESUMEN

The interaction of neurotrophins with their receptors is involved in the pathogenesis and progression of various neurological diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, spinal cord injury and acute and chronic cerebral damage. The p75 neurotrophin receptor (p75NTR) plays a pivotal role in the development of neurological dysfunctions as a result of its high expression, abnormal processing and signalling. Therefore, p75NTR represents as a vital therapeutic target for the treatment of neurodegeneration, neuropsychiatric disorders and cerebrovascular insufficiency. This review summarizes the current research progress on the p75NTR signalling in neurological deficits. We also summarize the present therapeutic approaches by genetically and pharmacologically targeting p75NTR for the attenuation of pathological changes. Based on the evolving knowledge, the role of p75NTR in the regulation of tau hyperphosphorylation, Aß metabolism, the degeneration of motor neurons and dopaminergic neurons has been discussed. Its position as a biomarker to evaluate the severity of diseases and as a druggable target for drug development has also been elucidated. Several prototype small molecule compounds were introduced to be crucial in neuronal survival and functional recovery via targeting p75NTR. These small molecule compounds represent desirable agents in attenuating neurodegeneration and cell death as they abolish activation-induced neurotoxicity of neurotrophins via modulating p75NTR signalling. More comprehensive and in-depth investigations on p75NTR-based drug development are required to shed light on effective treatment of numerous neurological disorders.


Asunto(s)
Enfermedades del Sistema Nervioso , Receptor de Factor de Crecimiento Nervioso , Biomarcadores , Desarrollo de Medicamentos , Humanos , Factores de Crecimiento Nervioso , Enfermedades del Sistema Nervioso/tratamiento farmacológico , Receptor de Factor de Crecimiento Nervioso/metabolismo , Receptores de Factor de Crecimiento Nervioso/metabolismo
6.
Stem Cells ; 39(6): 803-818, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33554422

RESUMEN

The interplay between mesenchymal stem cells (MSCs) and immune cells has been studied for MSCs isolated from different tissues. However, the immunomodulatory capacity of urine stem cells (USCs) has not been adequately researched. The present study reports on the effect of USCs on peripheral blood lymphocytes. USCs were isolated and characterized before coculture with resting and with anti-CD3/CD28 bead stimulated lymphocytes. Similarly to bone marrow mesenchymal stem cells (BM-MSCs), USCs inhibited the proliferation of activated T lymphocytes and induced their apoptosis. However, they also induced strong activation, proliferation, and cytokine and antibody production by B lymphocytes. Molecular phenotype and supernatant analysis revealed that USCs secrete a range of cytokines and effector molecules, known to play a central role in B cell biology. These included B cell-activating factor (BAFF), interleukin 6 (IL-6) and CD40L. These findings raise the possibility of an unrecognized active role for kidney stem cells in modulating local immune cells.


Asunto(s)
Linfocitos B/fisiología , Supervivencia Celular/fisiología , Activación de Linfocitos/inmunología , Células Madre/citología , Células de la Médula Ósea/citología , Proliferación Celular/fisiología , Técnicas de Cocultivo , Citocinas/genética , Humanos , Células Madre Mesenquimatosas/citología , Células Madre/inmunología , Linfocitos T/citología
7.
Metab Brain Dis ; 37(6): 1941-1957, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35704147

RESUMEN

Most Alzheimer disease (AD) patients present as sporadic late onset AD, with metabolic factors playing an important role in the occurrence and development of AD. Given the link between peripheral insulin resistance and tau pathology in streptozotocin-injected and db/db mouse models of diabetes, we fed high fat diet (HFD) to pR5 mice expressing P301L mutant human tau, with the aim of developing a new model with characteristics of obesity, T2DM and AD to mimic AD patients exacerbated by obesity and T2DM, an increasing trend in modern society. In our study, pR5 and C57BL/6 (WT) mice were randomly allocated to a standard diet (STD) or HFD for 30 weeks starting at 8 weeks of age. Food intake was measured weekly, body weight and fasting glucose levels were measured fortnightly, and a comprehensive behavioral test battery was performed to assess anxiety, depression and cognitive dysfunction. Glucose and insulin tolerance tests were performed after 30 weeks of HFD. We also investigated the effect of long term HFD on tau pathology in the brains of WT and P301L mice by performing western blotting of whole brain homogenates for total tau, phosphorylated tau at Ser396 and Thr231. Our results show that pR5 mice fed with HFD are more vulnerable to diet induced obesity compared to WT, especially with increasing age. In addition, pR5 mice on HFD developed glucose intolerance and insulin resistance. It was identified that long term HFD significantly aggravates depression like behavior and impairs cognitive function in pR5 mice, and also induces anxiety like behavior in both pR5 and WT mice. Long term HFD was also shown to aggravate tau hyperphosphorylation in pR5 transgenic mice, and increase total and hyperphosphorylated tau in WT mice. These results indicate that diet induced obesity of pR5 transgenic mice expressing P301L mutant human tau generates T2DM, and aggravates tau phosphorylation, and is therefore a model useful for investigations that seek to understand the relationships between AD, T2DM and obesity, and the underlying biochemical changes and mechanisms associated with metabolic disorders and AD tauopathy.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Enfermedades Metabólicas , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/genética , Animales , Cognición , Disfunción Cognitiva/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Glucosa , Enfermedades Metabólicas/complicaciones , Enfermedades Metabólicas/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Obesidad/complicaciones , Proteínas tau
8.
Int J Mol Sci ; 23(3)2022 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-35163660

RESUMEN

Induced neural stem cells (iNSCs) reprogrammed from somatic cells hold great potentials for drug discovery, disease modelling and the treatment of neurological diseases. Although studies have shown that human somatic cells can be converted into iNSCs by introducing transcription factors, these iNSCs are unlikely to be used for clinical application due to the safety concern of using exogenous genes and viral transduction vectors. Here, we report the successful conversion of human fibroblasts into iNSCs using a cocktail of small molecules. Furthermore, our results demonstrate that these human iNSCs (hiNSCs) have similar gene expression profiles to bona fide NSCs, can proliferate, and are capable of differentiating into glial cells and functional neurons. This study collectively describes a novel approach based on small molecules to produce hiNSCs from human fibroblasts, which may be useful for both research and therapeutic purposes.


Asunto(s)
Diferenciación Celular , Fibroblastos/citología , Células-Madre Neurales/citología , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Astrocitos/citología , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Biomarcadores/metabolismo , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Línea Celular , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Fenómenos Electrofisiológicos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Ratones , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/metabolismo , Neuronas/citología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Oligodendroglía/citología , Oligodendroglía/efectos de los fármacos , Oligodendroglía/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
9.
FASEB J ; 34(2): 2541-2553, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31908023

RESUMEN

Brain-derived neurotrophic factor precursor (proBDNF) has been reported to strengthen the dysfunction of monocytes/macrophages in animal studies. However, it is still unknown the roles of proBDNF in the dysfunction of monocytes in the inflammatory diseases in humans. In the present study, we showed that proBDNF and pan neurotrophic receptor p75 were significantly upregulated in monocytes from healthy donors (HD) after lipopolysaccharide treatment. Exogenous proBDNF treatment upregulated CD40 and proinflammatory cytokines expression in monocytes including interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α. In Stanford type-A acute aortic dissection (AAD) patients, proBDNF was upregulated in CD14+ CD163+ CX3CR1+ M2- but not CD14+ CD68+ CCR2+ M1-like monocytes. In addition, sera from AAD patients activated gene expression of proinflammatory cytokines in cultured PBMCs from HD, which was attenuated by proBDNF monoclonal antibody (Ab-proB) treatment. These findings suggested that upregulation of proBDNF in M2-like monocytes may contribute to the proinflammatory response in the AAD.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Citocinas/metabolismo , Macrófagos/metabolismo , Monocitos/metabolismo , Precursores de Proteínas/metabolismo , Adulto , Disección Aórtica/metabolismo , Células Cultivadas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia Arriba
10.
Int J Mol Sci ; 22(14)2021 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-34299000

RESUMEN

Parkinson's disease (PD) is the most common movement disorder, characterized by progressive degeneration of the nigrostriatal pathway, which consists of dopaminergic cell bodies in substantia nigra and their neuronal projections to the striatum. Moreover, PD is associated with an array of non-motor symptoms such as olfactory dysfunction, gastrointestinal dysfunction, impaired regulation of the sleep-wake cycle, anxiety, depression, and cognitive impairment. Inflammation and concomitant oxidative stress are crucial in the pathogenesis of PD. Thus, this study aimed to model PD via intrastriatal injection of the inflammagen lipopolysaccharide (LPS)to investigate if the lesion causes olfactory and motor impairments, inflammation, oxidative stress, and alteration in synaptic proteins in the olfactory bulb, striatum, and colon. Ten µg of LPS was injected unilaterally into the striatum of 27 male C57BL/6 mice, and behavioural assessment was conducted at 4 and 8 weeks post-treatment, followed by tissue collection. Intrastriatal LPS induced motor impairment in C57BL/6 mice at 8 weeks post-treatment evidenced by reduced latency time in the rotarod test. LPS also induced inflammation in the striatum characterized by increased expression of microglial marker Iba-1 and astrocytic marker GFAP, with degeneration of dopaminergic neuronal fibres (reduced tyrosine hydroxylase immunoreactivity), and reduction of synaptic proteins and DJ-1 protein. Additionally, intrastriatal LPS induced inflammation, oxidative stress and alterations in synaptic proteins within the olfactory bulb, although this did not induce a significant impairment in olfactory function. Intrastriatal LPS induced mild inflammatory changes in the distal colon, accompanied by increased protein expression of 3-nitrotyrosine-modified proteins. This model recapitulated the major features of PD such as motor impairment and degeneration of dopaminergic neuronal fibres in the striatum, as well as some pathological changes in the olfactory bulb and colon; thus, this model could be suitable for understanding clinical PD and testing neuroprotective strategies.


Asunto(s)
Astrocitos/metabolismo , Colon/metabolismo , Cuerpo Estriado/metabolismo , Neuronas Dopaminérgicas/metabolismo , Lipopolisacáridos/metabolismo , Bulbo Olfatorio/metabolismo , Enfermedad de Parkinson/metabolismo , Animales , Astrocitos/efectos de los fármacos , Astrocitos/patología , Escala de Evaluación de la Conducta , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Proteínas de Unión al Calcio/metabolismo , Colon/patología , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/patología , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/patología , Proteína Ácida Fibrilar de la Glía/metabolismo , Inmunohistoquímica , Inflamación/metabolismo , Inflamación/patología , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas de Microfilamentos/metabolismo , Microglía/metabolismo , Microglía/patología , Bulbo Olfatorio/efectos de los fármacos , Bulbo Olfatorio/patología , Estrés Oxidativo/efectos de los fármacos , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/psicología , Proteína Desglicasa DJ-1/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Sustancia Negra/metabolismo , Sustancia Negra/patología , Tirosina 3-Monooxigenasa/metabolismo , alfa-Sinucleína/metabolismo
11.
Int J Mol Sci ; 22(1)2021 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-33466423

RESUMEN

Elucidation of the biological functions of extracellular vesicles (EVs) and their potential roles in physiological and pathological processes is an expanding field of research. In this study, we characterized USC-derived EVs and studied their capacity to modulate the human immune response in vitro. We found that the USC-derived EVs are a heterogeneous population, ranging in size from that of micro-vesicles (150 nm-1 µm) down to that of exosomes (60-150 nm). Regarding their immunomodulatory functions, we found that upon isolation, the EVs (60-150 nm) induced B cell proliferation and IgM antibody secretion. Analysis of the EV contents unexpectedly revealed the presence of BAFF, APRIL, IL-6, and CD40L, all known to play a central role in B cell stimulation, differentiation, and humoral immunity. In regard to their effect on T cell functions, they resembled the function of mesenchymal stem cell (MSC)-derived EVs previously described, suppressing T cell response to activation. The finding that USC-derived EVs transport a potent bioactive cargo opens the door to a novel therapeutic avenue for boosting B cell responses in immunodeficiency or cancer.


Asunto(s)
Linfocitos B/inmunología , Vesículas Extracelulares/inmunología , Activación de Linfocitos/inmunología , Adulto , Diferenciación Celular/inmunología , Proliferación Celular/fisiología , Exosomas/inmunología , Humanos , Inmunidad Humoral/inmunología , Inmunoglobulina M/inmunología , Inmunomodulación/inmunología , Masculino , Células Madre Mesenquimatosas/inmunología , Persona de Mediana Edad , Linfocitos T/inmunología , Adulto Joven
12.
Mol Biol Rep ; 47(4): 2713-2722, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32185687

RESUMEN

Neural cell transplantation is an effective way for treatment of neurological diseases. However, the absence of transplantable human neurons remains a barrier for clinical therapies. Human urine-derived cells, namely renal cells and urine stem cells, have become a good source of cells for reprogramming or trans-differentiation research. Here, we show that human urine-derived cells can be partially converted into neuron-like cells by applying a cocktail of small molecules. Gene expression analysis has shown that these induced cells expressed some neuron-specific genes, and a proportion of the cells are GABAergic neurons. Moreover, whole-cell patch clamping recording has shown that some induced cells have neuron-specific voltage gated Na+ and K+ currents but have failed to generate Ca2+ currents and action potentials. Taken together, these results suggest that induced neuronal cells from human urine-derived cells may be useful for neurological disease modelling, drug screening and cell therapies.


Asunto(s)
Técnicas de Cultivo de Célula/métodos , Células-Madre Neurales/citología , Neuronas/metabolismo , Orina/citología , Potenciales de Acción/efectos de los fármacos , Adulto , Diferenciación Celular/efectos de los fármacos , Células Cultivadas/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/citología , Masculino , Persona de Mediana Edad , Células-Madre Neurales/metabolismo , Neuronas/patología , Técnicas de Placa-Clamp
13.
Mol Cell Neurosci ; 99: 103395, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31422108

RESUMEN

BACE1 is a transmembrane aspartic protease that cleaves various substrates and it is required for normal brain function. BACE1 expression is high during early development, but it is reduced in adulthood. Under conditions of stress and injury, BACE1 levels are increased; however, the underlying mechanisms that drive BACE1 elevation are not well understood. One mechanism associated with brain injury is the activation of injurious p75 neurotrophin receptor (p75), which can trigger pathological signals. Here we report that within 72 h after controlled cortical impact (CCI) or laser injury, BACE1 and p75 are increased and tightly co-expressed in cortical neurons of mouse brain. Additionally, BACE1 is not up-regulated in p75 null mice in response to focal cortical injury, while p75 over-expression results in BACE1 augmentation in HEK-293 and SY5Y cell lines. A luciferase assay conducted in SY5Y cell line revealed that BACE1 expression is regulated at the transcriptional level in response to p75 transfection. Interestingly, this effect does not appear to be dependent upon p75 ligands including mature and pro-neurotrophins. In addition, BACE1 activity on amyloid precursor protein (APP) is enhanced in SY5Y-APP cells transfected with a p75 construct. Lastly, we found that the activation of c-jun n-terminal kinase (JNK) by p75 contributes to BACE1 up-regulation. This study explores how two injury-induced molecules are intimately connected and suggests a potential link between p75 signaling and the expression of BACE1 after brain injury.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/metabolismo , Lesiones Traumáticas del Encéfalo/metabolismo , Receptor de Factor de Crecimiento Nervioso/metabolismo , Secretasas de la Proteína Precursora del Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Ácido Aspártico Endopeptidasas/genética , Línea Celular Tumoral , Células Cultivadas , Corteza Cerebral/metabolismo , Células HEK293 , Humanos , MAP Quinasa Quinasa 4/metabolismo , Masculino , Ratones , Receptor de Factor de Crecimiento Nervioso/genética , Transducción de Señal , Regulación hacia Arriba
14.
Neurobiol Dis ; 132: 104567, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31394202

RESUMEN

Neurofibrillary tangles of hyperphosphorylated tau protein (p-tau) are a key pathological feature of Alzheimer's disease (AD). Tau phosphorylation is suggested to be secondary to amyloid-beta (Aß) accumulation. However, the mechanism by which Aß induces tau phosphorylation in neurons remains unclear. Neurotrophin receptor p75 (p75NTR) is a receptor for Aß and mediates Aß neurotoxicity, implying that p75NTR may mediate Aß-induced tau phosphorylation in AD. Here, we showed that Aß-induced tau hyperphosphorylation and neurodegeneration, including tau phosphorylation, synaptic disorder and neuronal loss, in the brains of both male wild-type (Wt) mice and male P301L transgenic mice (a mouse model of human tauopathy) were alleviated by genetic knockout of p75NTR in the both mouse models. We further confirmed that the activation or inhibition of cyclin-dependent kinase 5 (CDK5) and glycogen synthase kinase-3ß (GSK3ß) significantly changed Aß/p75NTR-mediated p-tau levels in neurons. Treatment of male P301L mice with soluble p75NTR extracellular domain (p75ECD-Fc), which antagonizes the binding of Aß to p75NTR, suppressed tau hyperphosphorylation. Taken together, our findings suggest that p75NTR meditates Aß-induced tau pathology and is a potential druggable target for AD and other tauopathies.


Asunto(s)
Péptidos beta-Amiloides/toxicidad , Receptores de Factor de Crecimiento Nervioso/metabolismo , Tauopatías/metabolismo , Proteínas tau/metabolismo , Animales , Células Cultivadas , Masculino , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Distribución Aleatoria , Receptores de Factor de Crecimiento Nervioso/administración & dosificación , Receptores de Factor de Crecimiento Nervioso/genética , Tauopatías/tratamiento farmacológico , Tauopatías/genética , Proteínas tau/antagonistas & inhibidores , Proteínas tau/genética
15.
Mol Psychiatry ; 23(8): 1813-1824, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29867188

RESUMEN

Tau pathology is characterized as a form of frontotemporal lobar degeneration (FTLD) known as FTLD-tau. The underlying pathogenic mechanisms are not known and no therapeutic interventions are currently available. Here, we report that the neurotrophin receptor p75NTR plays a critical role in the pathogenesis of FTLD-tau. The expression of p75NTR and the precursor of nerve growth factor (proNGF) were increased in the brains of FTLD-tau patients and mice (P301L transgenic). ProNGF-induced tau phosphorylation via p75NTR in vitro, which was associated with the AKT/glycogen synthase kinase (GSK)3ß pathway. Genetic reduction of p75NTR in P301L mice rescued the memory deficits, alleviated tau hyperphosphorylation and restored the activity of the AKT/GSK3ß pathway. Treatment of the P301L mice with the soluble p75NTR extracellular domain (p75ECD-Fc), which can antagonize neurotoxic ligands of p75NTR, effectively improved memory behavior and suppressed tau pathology. This suggests that p75NTR plays a crucial role in tau paGSKthology and represents a potential druggable target for FTLD-tau and related tauopathies.


Asunto(s)
Degeneración Lobar Frontotemporal/metabolismo , Factor de Crecimiento Nervioso/metabolismo , Precursores de Proteínas/metabolismo , Receptores de Factor de Crecimiento Nervioso/metabolismo , Proteínas tau/metabolismo , Animales , Encéfalo/metabolismo , Encéfalo/patología , Células Cultivadas , Femenino , Degeneración Lobar Frontotemporal/patología , Degeneración Lobar Frontotemporal/terapia , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Masculino , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/patología , Trastornos de la Memoria/terapia , Ratones Transgénicos , Neuronas/metabolismo , Neuronas/patología , Fosforilación/fisiología , Cultivo Primario de Células , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal
16.
J Cell Physiol ; 233(3): 2133-2145, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28370021

RESUMEN

Neurotrophins and their receptors are key molecules that are known to be critical in regulating nervous system development and maintenance and have been recognized to be also involved in regulating tissue formation and healing in skeletal tissues. Studies have shown that neurotrophins and their receptors are widely expressed in skeletal tissues, implicated in chondrogenesis, osteoblastogenesis, and osteoclastogenesis, and are also involved in regulating tissue formation and healing events in skeletal tissue. Increased mRNA expression for neurotrophins NGF, BDNF, NT-3, and NT-4, and their Trk receptors has been observed in injured bone tissues, and NT-3 and its receptor, TrkC, have been identified to have the highest induction at the injury site in a drill-hole injury repair model in both bone and the growth plate. In addition, NT-3 has also recently been shown to be both an osteogenic and angiogenic factor, and this neurotrophin can also enhance expression of the key osteogenic factor, BMP-2, as well as the major angiogenic factor, VEGF, to promote bone formation, vascularization, and healing of the injury site. Further studies, however, are needed to investigate if different neurotrophins have differential roles in skeletal repair, and if NT-3 can be a potential target of intervention for promoting bone fracture healing.


Asunto(s)
Remodelación Ósea/fisiología , Huesos/embriología , Condrogénesis/fisiología , Factores de Crecimiento Nervioso/metabolismo , Osteogénesis/fisiología , Receptor trkC/metabolismo , Proteína Morfogenética Ósea 2/biosíntesis , Huesos/irrigación sanguínea , Neovascularización Fisiológica/fisiología , Factores de Crecimiento Nervioso/genética , Neurotrofina 3 , Osteoblastos/fisiología , Receptor trkC/genética , Factor A de Crecimiento Endotelial Vascular/biosíntesis
17.
J Neurochem ; 144(3): 302-317, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28869759

RESUMEN

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive deposition of amyloid beta (Aß) and dysregulation of neurotrophic signaling, causing synaptic dysfunction, loss of memory, and cell death. The expression of p75 neurotrophin receptor is elevated in the brain of AD patients, suggesting its involvement in this disease. However, the exact mechanism of its action is not yet clear. Here, we show that p75 interacts with beta-site amyloid precursor protein cleaving enzyme-1 (BACE1), and this interaction is enhanced in the presence of Aß. Our results suggest that the colocalization of BACE1 and amyloid precursor protein (APP) is increased in the presence of both Aß and p75 in cortical neurons. In addition, the localization of APP and BACE1 in early endosomes is increased in the presence of Aß and p75. An increased phosphorylation of APP-Thr668 and BACE1-Ser498 by c-Jun N-terminal kinase (JNK) in the presence of Aß and p75 could be responsible for this localization. In conclusion, our study proposes a potential involvement in amyloidogenesis for p75, which may represent a future therapeutic target for AD. Cover Image for this Issue: doi. 10.1111/jnc.14163.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Péptidos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidasas/metabolismo , Corteza Cerebral/metabolismo , Endosomas/metabolismo , Neuronas/metabolismo , Receptores de Factor de Crecimiento Nervioso/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Modelos Animales de Enfermedad , Ratones Noqueados , Cultivo Primario de Células , Receptores de Factor de Crecimiento Nervioso/genética , Transducción de Señal
18.
Neurochem Res ; 43(3): 637-649, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29330684

RESUMEN

Treatment with mature brain-derived neurotrophic factor (mBDNF) promotes functional recovery after ischemia in animal trials but the possible role of its precursor protein proBDNF and its receptors or the factors responsible for the conversion of proBDNF to mBDNF in ischemic stroke are not known. The main aim of this study was to characterize the time-dependent expression of genes and/or proteins related to BDNF processing and signaling after ischemia as well as the sensorimotor behavioral dysfunction in a photothrombotic ischemic model in rats. Characterization of different genes and proteins related to BDNF processing and signaling was performed using qPCR, immunoblotting and enzyme-linked immunosorbent assays. We showed in this study that some sensory and motor functional deficiencies appeared in the ischemic group at day 1 and persisted until day 14. Most changes in gene expression of BDNF and its processing enzymes occurred within the first 24 h in the ipsilateral cortex, but not in the contralateral cortex. At the protein level, proBDNF expression was increased at 6 h, mBDNF expression was increased between 15 h and 1 day while p75 receptor protein expression was increased between 6 h and 3 days in the ipsilateral cortex, but not in the contralateral cortex. Therefore, cerebral ischemia in rats led to the up-regulation of genes and/or proteins of BDNF, proBDNF and their processing enzymes and receptors in a time-dependent manner. We propose that the balance between BDNF and proBDNF and their associated proteins may play an important role in the pathogenesis and recovery from ischemia.


Asunto(s)
Isquemia Encefálica/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Corteza Cerebral/metabolismo , Receptores de Factor de Crecimiento Nervioso/metabolismo , Animales , Animales Recién Nacidos , Precursores de Proteínas/metabolismo , Ratas Sprague-Dawley , Transducción de Señal/fisiología , Regulación hacia Arriba
19.
Proc Natl Acad Sci U S A ; 112(16): 5225-30, 2015 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-25847999

RESUMEN

Alzheimer's disease (AD) is one of most devastating diseases affecting elderly people. Amyloid-ß (Aß) accumulation and the downstream pathological events such as oxidative stress play critical roles in pathogenesis of AD. Lessons from failures of current clinical trials suggest that targeting multiple key pathways of the AD pathogenesis is necessary to halt the disease progression. Here we show that Edaravone, a free radical scavenger that is marketed for acute ischemic stroke, has a potent capacity of inhibiting Aß aggregation and attenuating Aß-induced oxidation in vitro. When given before or after the onset of Aß deposition via i.p. injection, Edaravone substantially reduces Aß deposition, alleviates oxidative stress, attenuates the downstream pathologies including Tau hyperphosphorylation, glial activation, neuroinflammation, neuronal loss, synaptic dysfunction, and rescues the behavioral deficits of APPswe/PS1 mice. Oral administration of Edaravone also ameliorates the AD-like pathologies and memory deficits of the mice. These findings suggest that Edaravone holds a promise as a therapeutic agent for AD by targeting multiple key pathways of the disease pathogenesis.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Antipirina/análogos & derivados , Trastornos del Conocimiento/tratamiento farmacológico , Administración Oral , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/patología , Amiloide/metabolismo , Péptidos beta-Amiloides/toxicidad , Animales , Antipirina/administración & dosificación , Antipirina/química , Antipirina/farmacología , Antipirina/uso terapéutico , Conducta Animal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/patología , Línea Celular , Trastornos del Conocimiento/complicaciones , Trastornos del Conocimiento/patología , Dendritas/efectos de los fármacos , Dendritas/patología , Edaravona , Humanos , Inflamación/patología , Ratones Transgénicos , Neurotoxinas/toxicidad , Estrés Oxidativo/efectos de los fármacos , Fosforilación/efectos de los fármacos , Presenilina-1/metabolismo , Agregación Patológica de Proteínas/complicaciones , Agregación Patológica de Proteínas/tratamiento farmacológico , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Proteínas tau/metabolismo
20.
J Stroke Cerebrovasc Dis ; 27(7): 1992-1997, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29673615

RESUMEN

BACKGROUND: To investigate the effects of abdominal obesity (AO) and nonalcoholic fatty liver disease (NAFLD) with or without AO on carotid arteries by determining carotid intima-media thickness (CIMT). METHODS: A total of 2745 Chinese Han adults (aged between 40 and 50 years old) were recruited and divided into 4 groups: (1) NW-no NAFL group: the normal body weight without NAFLD (n = 1888); (2) AO-no NAFL group: AO without NAFLD (n = 259); (3) NW-with NAFL group: NAFLD without AO (n = 93); and (4) AO-with NAFL group: AO with NAFLD (n = 505). The CIMT rate of each group was compared among 4 groups and the regression analysis was further used to correct confounders. RESULTS: We found that the NW-with NAFL group had a significantly higher CIMT rate than the AO-no NAFL group ([.87 ± .31] versus [.72 ± .29] P < .01) and the AO-with NAFL group ([.87 ± .31] versus [.79 ± .26], P < .01). CONCLUSIONS: The ectopic liver fat accumulation may increase the risk of atherosclerosis. Therefore, screening NAFLD in the population with normal weight may be beneficial for the prevention of atherosclerosis at an early stage.


Asunto(s)
Arterias Carótidas/diagnóstico por imagen , Grosor Intima-Media Carotídeo , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Obesidad Abdominal/diagnóstico por imagen , Tejido Adiposo/diagnóstico por imagen , Adulto , Aterosclerosis/diagnóstico por imagen , Composición Corporal , China , Femenino , Humanos , Hígado/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Análisis de Regresión , Factores de Riesgo
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