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1.
BMC Nephrol ; 25(1): 123, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38580974

RESUMEN

BACKGROUND: Primary focal segmental glomerulosclerosis (FSGS) is a glomerular disease that sometimes recurs in patients after kidney transplantation (KT) and increases the risk of graft loss. Proteinuria is a common early sign of recurrent FSGS, but an abrupt decrease in urine volume is rare. Herein, we report a patient with early recurrence of FSGS with anuria following KT. CASE PRESENTATION: A 55-year-old man with end-stage kidney disease caused by primary FSGS experienced anuria on postoperative day 2 following deceased donor KT. Laboratory results revealed that serum tacrolimus trough levels were consistently elevated at the time of anuria. At first, we considered acute calcineurin inhibitor (CNI) nephrotoxicity based on graft biopsy on light microscopy, laboratory findings, and clinical courses. However, the allograft function did not recover even after discontinuation of CNI, and recurrent FSGS was diagnosed 2 weeks later on electron microscopy. A total of 13 sessions of plasmapheresis and two administrations of rituximab (375 mg/m2) were required to treat recurrent FSGS. The patient achieved a partial response, and the spot urine protein-to-creatinine ratio decreased from 15.5 g/g creatinine to 5.2 g/g creatinine. At 5 months following KT, the serum creatinine level was stable at 1.15 mg/dL. CONCLUSIONS: These findings highlight that anuria can occur in cases of early recurrence of FSGS combined with acute CNI nephrotoxicity.


Asunto(s)
Anuria , Glomeruloesclerosis Focal y Segmentaria , Enfermedades Renales , Trasplante de Riñón , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de la Calcineurina/toxicidad , Creatinina , Glomeruloesclerosis Focal y Segmentaria/diagnóstico , Glomeruloesclerosis Focal y Segmentaria/etiología , Glomeruloesclerosis Focal y Segmentaria/tratamiento farmacológico , Trasplante de Riñón/efectos adversos , Trasplante de Riñón/métodos , Recurrencia
2.
Int J Mol Sci ; 23(12)2022 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-35743267

RESUMEN

Recent advances in optical clearing techniques have dramatically improved deep tissue imaging by reducing the obscuring effects of light scattering and absorption. However, these optical clearing methods require specialized equipment or a lengthy undertaking with complex protocols that can lead to sample volume changes and distortion. In addition, the imaging of cleared tissues has limitations, such as fluorescence bleaching, harmful and foul-smelling solutions, and the difficulty of handling samples in high-viscosity refractive index (RI) matching solutions. To address the various limitations of thick tissue imaging, we developed an Aqueous high refractive Index matching and tissue Clearing solution for Imaging (termed AICI) with a one-step tissue clearing protocol that was easily made at a reasonable price in our own laboratory without any equipment. AICI can rapidly clear a 1 mm thick brain slice within 90 min with simultaneous RI matching, low viscosity, and a high refractive index (RI = 1.466), allowing the imaging of the sample without additional processing. We compared AICI with commercially available RI matching solutions, including optical clear agents (OCAs), for tissue clearing. The viscosity of AICI is closer to that of water compared with other RI matching solutions, and there was a less than 2.3% expansion in the tissue linear morphology during 24 h exposure to AICI. Moreover, AICI remained fluid over 30 days of air exposure, and the EGFP fluorescence signal was only reduced to ~65% after 10 days. AICI showed a limited clearing of brain tissue >3 mm thick. However, fine neuronal structures, such as dendritic spines and axonal boutons, could still be imaged in thick brain slices treated with AICI. Therefore, AICI is useful not only for the three-dimensional (3D) high-resolution identification of neuronal structures, but also for the examination of multiple structural imaging by neuronal distribution, projection, and gene expression in deep brain tissue. AICI is applicable beyond the imaging of fluorescent antibodies and dyes, and can clear a variety of tissue types, making it broadly useful to researchers for optical imaging applications.


Asunto(s)
Encéfalo , Imagen Óptica , Animales , Encéfalo/diagnóstico por imagen , Técnica del Anticuerpo Fluorescente , Imagenología Tridimensional/métodos , Ratones , Neuronas , Imagen Óptica/métodos , Refractometría
3.
FASEB J ; 34(5): 6965-6983, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32237183

RESUMEN

Microtubule-associated protein (MAP) 2 has been perceived as a static cytoskeletal protein enriched in neuronal dendritic shafts. Emerging evidence indicates dynamic functions for various MAPs in activity-dependent synaptic plasticity. However, it is unclear how MAP2 is associated with synaptic plasticity mechanisms. Here, we demonstrate that specific silencing of high-molecular-weight MAP2 in vivo abolished induction of long-term potentiation (LTP) in the Schaffer collateral pathway of CA1 pyramidal neurons and in vitro blocked LTP-induced surface delivery of AMPA receptors and spine enlargement. In mature hippocampal neurons, we observed rapid translocation of a subpopulation of MAP2, present in dendritic shafts, to spines following LTP stimulation. Time-lapse confocal imaging showed that spine translocation of MAP2 was coupled with LTP-induced spine enlargement. Consistently, immunogold electron microscopy revealed that LTP stimulation of the Schaffer collateral pathway promoted MAP2 labeling in spine heads of CA1 neurons. This translocation depended on NMDA receptor activation and Ras-MAPK signaling. Furthermore, LTP stimulation led to an increase in surface-expressed AMPA receptors specifically in the neurons with MAP2 spine translocation. Altogether, this study indicates a novel role for MAP2 in LTP mechanisms and suggests that MAP2 participates in activity-dependent synaptic plasticity in mature hippocampal networks.


Asunto(s)
Región CA1 Hipocampal/citología , Región CA1 Hipocampal/metabolismo , Potenciación a Largo Plazo/fisiología , Proteínas Asociadas a Microtúbulos/metabolismo , Células Piramidales/metabolismo , Animales , Células Cultivadas , Espinas Dendríticas/metabolismo , Espinas Dendríticas/ultraestructura , Técnicas In Vitro , Sistema de Señalización de MAP Quinasas , Masculino , Ratones Endogámicos C57BL , Microscopía Inmunoelectrónica , Proteínas Asociadas a Microtúbulos/antagonistas & inhibidores , Proteínas Asociadas a Microtúbulos/genética , Plasticidad Neuronal/fisiología , Transporte de Proteínas , Células Piramidales/ultraestructura , Interferencia de ARN , ARN Interferente Pequeño/genética , Ratas , Receptores AMPA/metabolismo
4.
Proc Natl Acad Sci U S A ; 113(24): 6749-54, 2016 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-27226294

RESUMEN

Neural Abelson-related gene-binding protein 2 (nArgBP2) was originally identified as a protein that directly interacts with synapse-associated protein 90/postsynaptic density protein 95-associated protein 3 (SAPAP3), a postsynaptic scaffolding protein critical for the assembly of glutamatergic synapses. Although genetic deletion of nArgBP2 in mice leads to manic/bipolar-like behaviors resembling many aspects of symptoms in patients with bipolar disorder, the actual function of nArgBP2 at the synapse is completely unknown. Here, we found that the knockdown (KD) of nArgBP2 by specific small hairpin RNAs (shRNAs) resulted in a dramatic change in dendritic spine morphology. Reintroducing shRNA-resistant nArgBP2 reversed these defects. In particular, nArgBP2 KD impaired spine-synapse formation such that excitatory synapses terminated mostly at dendritic shafts instead of spine heads in spiny neurons, although inhibitory synapse formation was not affected. nArgBP2 KD further caused a marked increase of actin cytoskeleton dynamics in spines, which was associated with increased Wiskott-Aldrich syndrome protein-family verprolin homologous protein 1 (WAVE1)/p21-activated kinase (PAK) phosphorylation and reduced activity of cofilin. These effects of nArgBP2 KD in spines were rescued by inhibiting PAK or activating cofilin combined with sequestration of WAVE. Together, our results suggest that nArgBP2 functions to regulate spine morphogenesis and subsequent spine-synapse formation at glutamatergic synapses. They also raise the possibility that the aberrant regulation of synaptic actin filaments caused by reduced nArgBP2 expression may contribute to the manifestation of the synaptic dysfunction observed in manic/bipolar disorder.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Espinas Dendríticas/metabolismo , Sinapsis/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Trastorno Bipolar/genética , Trastorno Bipolar/metabolismo , Técnicas de Silenciamiento del Gen , Ratones , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Ratas , Ratas Sprague-Dawley , Sinapsis/genética
5.
J Cell Sci ; 128(9): 1848-61, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25795301

RESUMEN

The 5-hydroxytryptamine (5-HT, also known as serotonin) subtype 6 receptor (5-HT6R, also known as HTR6) plays roles in cognition, anxiety and learning and memory disorders, yet new details concerning its regulation remain poorly understood. In this study, we found that 5-HT6R directly interacted with SNX14 and that this interaction dramatically increased internalization and degradation of 5-HT6R. Knockdown of endogenous SNX14 had the opposite effect. SNX14 is highly expressed in the brain and contains a putative regulator of G-protein signaling (RGS) domain. Although its RGS domain was found to be non-functional as a GTPase activator for Gαs, we found that it specifically bound to and sequestered Gαs, thus inhibiting downstream cAMP production. We further found that protein kinase A (PKA)-mediated phosphorylation of SNX14 inhibited its binding to Gαs and diverted SNX14 from Gαs binding to 5-HT6R binding, thus facilitating the endocytic degradation of the receptor. Therefore, our results suggest that SNX14 is a dual endogenous negative regulator in 5-HT6R-mediated signaling pathway, modulating both signaling and trafficking of 5-HT6R.


Asunto(s)
Neuronas/metabolismo , Receptores de Serotonina/metabolismo , Transducción de Señal , Nexinas de Clasificación/metabolismo , Animales , Membrana Celular/metabolismo , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Citosol/metabolismo , Endocitosis , Subunidades alfa de la Proteína de Unión al GTP Gs/metabolismo , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Ratones , Fosforilación , Fosfoserina/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Proteolisis , Ratas
6.
Chem Pharm Bull (Tokyo) ; 65(9): 826-832, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28867709

RESUMEN

The tubers of Corydalis ternata have been used to treat cardiovascular diseases such as hypertension and cardiac arrhythmia. Its active components have anticholinesterase, antiamnesic, and anti-inflammatory activities, and analgesic effects. In the present study, we performed quantitative analyses of the two components of C. ternata, coptisine and berberine, using HPLC. A 70% ethanol extract of C. ternata was prepared and the two components were separated using a C-18 analytical column on a gradient solvent system of acetonitrile and 0.1% (v/v) aqueous trifluoroacetic acid. Recordings were performed at a UV wavelength of 265 nm for two standard components. The established analytical method showed high linearity (correlation coefficient (r)=1.0000) and proper precision (0.49-3.88%), accuracy (97.88-102.7%), and recovery (95.12-103.79%) for two standard components. The amount of the coptisine and berberine was 4.968±0.089 mg/g and 3.73±0.075 mg/g, respectively. In addition, we investigated the effects of coptisine and berberine on acetylcholinesterase activity and amyloid-ß aggregation, which are major biomarkers of dementia. Coptisine and berberine decreased acetylcholinesterase activity in a dose-dependent manner (IC50=0.74 and 0.48 µM, respectively). The C. ternata extract exerted an antioxidant activity by stimulating the radical scavenging activity of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), but not 2,2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, the C. ternata extract reversed the hydrogen peroxide-induced death of HT22 hippocampal cells, indicating its neuroprotective effect. Our results suggest the potential of C. ternata as a therapeutic agent against dementia via the inhibition of acetylcholinesterase activity and neuronal cell death.


Asunto(s)
Corydalis/química , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Acetilcolinesterasa/química , Acetilcolinesterasa/metabolismo , Berberina/análogos & derivados , Berberina/química , Berberina/aislamiento & purificación , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Corydalis/metabolismo , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/aislamiento & purificación , Humanos , Peróxido de Hidrógeno/toxicidad , Fármacos Neuroprotectores/aislamiento & purificación , Extractos Vegetales/química , Tubérculos de la Planta/química , Tubérculos de la Planta/metabolismo
7.
Molecules ; 22(6)2017 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-28574473

RESUMEN

The dried bark of Phellodendron chinense has been used as a traditional herbal medicine to remove damp heat, relieve consumptive fever, and cure dysentery and diarrhea. In the present study, we performed quantitative analyses of the two components of P. chinense, phellodendrine and berberine, using high-performance liquid chromatography. A 70% ethanol extract of P. chinense was prepared and the two components were separated on a C-18 analytical column using a gradient solvent system of acetonitrile and 0.1% (v/v) aqueous trifluoroacetic acid. The ultraviolet wavelength used for detection was 200 nm for phellodendrine and 226 nm for berberine. The analytical method established here showed high linearity (correlation coefficient, ≥0.9991). The amount of phellodendrine and berberine used was 22.255 ± 0.123 mg/g and 269.651 ± 1.257 mg/g, respectively. Moreover, we performed an in vitro acetylcholinesterase (AChE) activity assay and an amyloid-ß aggregation test to examine the biological properties of phellodendrine and berberine as therapeutic drugs for Alzheimer's disease. Phellodendrine and berberine inhibited AChE activity in a dose-dependent manner (IC50 = 36.51 and 0.44 µM, respectively). In contrast, neither phellodendrine nor berberine had an effect on amyloid-ß aggregation. The P. chinense extract and phellodendrine, but not berberine, exhibited antioxidant activity by increasing radical scavenging activity. Moreover, P. chinense demonstrated a neuroprotective effect in hydrogen peroxide-treated HT22 hippocampal cells. Overall, our findings suggest that P. chinense has potential as an anti-Alzheimer's agent via the suppression of the enzymatic activity of acetylcholinesterase and the stimulation of antioxidant activity.


Asunto(s)
Inhibidores de la Colinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Phellodendron/química , Fitoquímicos/química , Fitoquímicos/farmacología , Extractos Vegetales/química , Péptidos beta-Amiloides/metabolismo , Animales , Antioxidantes/farmacología , Biomarcadores , Cromatografía Líquida de Alta Presión , Ratones , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacología , Agregado de Proteínas/efectos de los fármacos , Agregación Patológica de Proteínas , Sensibilidad y Especificidad
8.
J Biol Chem ; 290(12): 7323-35, 2015 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-25605715

RESUMEN

Recent studies have reported conflicting results regarding the role of ARF6 in dendritic spine development, but no clear answer for the controversy has been suggested. We found that ADP-ribosylation factor 6 (ARF6) either positively or negatively regulates dendritic spine formation depending on neuronal maturation and activity. ARF6 activation increased the spine formation in developing neurons, whereas it decreased spine density in mature neurons. Genome-wide microarray analysis revealed that ARF6 activation in each stage leads to opposite patterns of expression of a subset of genes that are involved in neuronal morphology. ARF6-mediated Rac1 activation via the phospholipase D pathway is the coincident factor in both stages, but the antagonistic RhoA pathway becomes involved in the mature stage. Furthermore, blocking neuronal activity in developing neurons using tetrodotoxin or enhancing the activity in mature neurons using picrotoxin or chemical long term potentiation reversed the effect of ARF6 on each stage. Thus, activity-dependent dynamic changes in ARF6-mediated spine structures may play a role in structural plasticity of mature neurons.


Asunto(s)
Factores de Ribosilacion-ADP/fisiología , Espinas Dendríticas , Neuronas/citología , Factor 6 de Ribosilación del ADP , Animales , Secuencia de Bases , Células Cultivadas , Hipocampo/citología , Hipocampo/embriología , ARN Interferente Pequeño/genética , Ratas , Ratas Sprague-Dawley
9.
J Neurosci ; 34(30): 10085-95, 2014 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-25057210

RESUMEN

Secretory carrier membrane protein 5 (SCAMP5), a recently identified candidate gene for autism, is brain specific and highly abundant in synaptic vesicles (SVs), but its function is currently unknown. Here, we found that knockdown (KD) of endogenous SCAMP5 by SCAMP5-specific shRNAs in cultured rat hippocampal neurons resulted in a reduction in total vesicle pool size as well as in recycling pool size, but the recycling/resting pool ratio was significantly increased. SCAMP5 KD slowed endocytosis after stimulation, but impaired it severely during strong stimulation. We also found that KD dramatically lowered the threshold of activity at which SV endocytosis became unable to compensate for the ongoing exocytosis occurring during a stimulus. Reintroducing shRNA-resistant SCAMP5 reversed these endocytic defects. Therefore, our results suggest that SCAMP5 functions during high neuronal activity when a heavy load is imposed on endocytosis. Our data also raise the possibility that the reduction in expression of SCAMP5 in autistic patients may be related to the synaptic dysfunction observed in autism.


Asunto(s)
Proteínas Portadoras/fisiología , Endocitosis/fisiología , Proteínas de la Membrana/fisiología , Neuronas/fisiología , Vesículas Sinápticas/fisiología , Animales , Proteínas Portadoras/genética , Endocitosis/genética , Femenino , Técnicas de Silenciamiento del Gen , Células HEK293 , Hipocampo/citología , Hipocampo/fisiología , Humanos , Masculino , Proteínas de la Membrana/genética , Cultivo Primario de Células , Ratas , Ratas Sprague-Dawley , Vesículas Sinápticas/genética
10.
J Biol Chem ; 288(41): 29453-66, 2013 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-24003235

RESUMEN

SNX26, a brain-enriched RhoGAP, plays a key role in dendritic arborization during early neuronal development in the neocortex. In mature neurons, it is localized to dendritic spines, but little is known about its role in later stages of development. Our results show that SNX26 interacts with PSD-95 in dendritic spines of cultured hippocampal neurons, and as a GTPase-activating protein for Cdc42, it decreased the F-actin content in COS-7 cells and in dendritic spines of neurons. Overexpression of SNX26 resulted in a GTPase-activating protein activity-dependent decrease in total protrusions and spine density together with dramatic inhibition of filopodia-to-spine transformations. Such effects of SNX26 were largely rescued by a constitutively active mutant of Cdc42. Consistently, an shRNA-mediated knockdown of SNX26 significantly increased total protrusions and spine density, resulting in an increase in thin or stubby type spines at the expense of the mushroom spine type. Moreover, endogenous expression of SNX26 was shown to be bi-directionally modulated by neuronal activity. Therefore, we propose that in addition to its key role in neuronal development, SNX26 also has a role in the activity-dependent structural change of dendritic spines in mature neurons.


Asunto(s)
Espinas Dendríticas/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Guanilato-Quinasas/metabolismo , Proteínas de la Membrana/metabolismo , Neuronas/metabolismo , Nexinas de Clasificación/metabolismo , Actinas/metabolismo , Animales , Sitios de Unión , Células COS , Células Cultivadas , Chlorocebus aethiops , Homólogo 4 de la Proteína Discs Large , Proteínas Activadoras de GTPasa/genética , Guanilato-Quinasas/genética , Células HEK293 , Hipocampo/citología , Hipocampo/crecimiento & desarrollo , Hipocampo/metabolismo , Humanos , Immunoblotting , Proteínas de la Membrana/genética , Ratones , Microscopía Confocal , Neuronas/citología , Unión Proteica , Seudópodos/metabolismo , Interferencia de ARN , Ratas , Nexinas de Clasificación/genética , Factores de Tiempo
11.
Methods Protoc ; 6(6)2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-37987355

RESUMEN

Whole-brain imaging is important for understanding brain functions through deciphering tissue structures, neuronal circuits, and single-neuron tracing. Thus, many clearing methods have been developed to acquire whole-brain images or images of three-dimensional thick tissues. However, there are several limitations to imaging whole-brain volumes, including long image acquisition times, large volumes of data, and a long post-image process. Based on these limitations, many researchers are unsure about which light microscopy is most suitable for imaging thick tissues. Here, we compared fast-confocal microscopy with light-sheet fluorescence microscopy for whole-brain three-dimensional imaging, which can acquire images the fastest. To compare the two types of microscopies for large-volume imaging, we performed tissue clearing of a whole mouse brain, and changed the sample chamber and low- magnification objective lens and modified the sample holder of a light-sheet fluorescence microscope. We found out that light-sheet fluorescence microscopy using a 2.5× objective lens possesses several advantages, including saving time, large-volume image acquisitions, and high Z-resolution, over fast-confocal microscopy, which uses a 4× objective lens. Therefore, we suggest that light-sheet fluorescence microscopy is suitable for whole mouse brain imaging and for obtaining high-resolution three-dimensional images.

12.
Blood Adv ; 7(13): 3155-3168, 2023 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-36809797

RESUMEN

Acute myeloid leukemia (AML) generally has an unsatisfactory prognosis despite the recent introduction of new regimens, including targeted agents and antibodies. To find a new druggable pathway, we performed integrated bioinformatic pathway screening on large OHSU and MILE AML databases, discovered the SUMOylation pathway, and validated it independently with an external data set (totaling 2959 AML and 642 normal sample data). The clinical relevance of SUMOylation in AML was supported by its core gene expression which is correlated with patient survival, European LeukemiaNet 2017 risk classification, and AML-relevant mutations. TAK-981, a first-in-class SUMOylation inhibitor currently under clinical trials for solid tumors, showed antileukemic effects with apoptosis induction, cell-cycle arrest, and induction of differentiation marker expression in leukemic cells. It exhibited potent nanomolar activity, often stronger than that of cytarabine, which is part of the standard of care. TAK-981's utility was further demonstrated in in vivo mouse and human leukemia models as well as patient-derived primary AML cells. Our results also indicate direct and cancer cell-inherent anti-AML effects by TAK-981, different from the type 1 interferon and immune-dependent mechanism in a previous solid tumor study. Overall, we provide a proof-of-concept for SUMOylation as a new targetable pathway in AML and propose TAK-981 as a promising direct anti-AML agent. Our data should prompt studies on optimal combination strategies and transitions to clinical trials in AML.


Asunto(s)
Antineoplásicos , Leucemia Mieloide Aguda , Animales , Ratones , Humanos , Apoptosis , Sumoilación , Proliferación Celular , Antineoplásicos/uso terapéutico , Leucemia Mieloide Aguda/genética
13.
J Cell Physiol ; 227(4): 1476-84, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21618538

RESUMEN

ßPix, a Pak-interacting nucleotide exchange factor (Cool-1/p85SPR), is a Cdc42/Rac1-specific guanine nucleotide exchange factor (GEF) involved in various actin-related processes. Many previous studies have focused on ubiquitously expressed ßPix-a, while the role of the neuronal-specific isoform ßPix-b is still unknown, especially whether its role is distinct from or similar to ßPix-a. Here we show that unlike ßPix-a, overexpression of ßPix-b stimulates actin-dependent comet formation in BHK21 cells. This effect is attributed to the interaction between its proline-rich domain (PRD) and the WH1 domain of N-WASP. In addition, we show that overexpression of ßPix-b stimulates actin-dependent dendritic spine formation in rat hippocampal neurons in culture, a formation that is blocked by co-expression of the WH1 domain of N-WASP or the PRD of ßPix-b. Knocking-down endogenous expression of ßPix-b by shRNA reduced the number of dendritic spines, which were rescued only by PRD-containing ßPix-b mutants. GEF activity of ßPix-b is also required for these effects. The results show that neuronal-specific ßPix-b stimulates actin-dependent processes in cells via the interaction between its PRD and the WH1 domain of N-WASP. Our results identify N-WASP as the first protein shown to interact with the PRD of ßPix-b, raising the possibility that, as an N-WASP WH1-binding protein, ßPix-b may regulate N-WASP's activity in cells.


Asunto(s)
Actinas/metabolismo , Factores de Intercambio de Guanina Nucleótido/química , Factores de Intercambio de Guanina Nucleótido/metabolismo , Neuronas/metabolismo , Proteína Neuronal del Síndrome de Wiskott-Aldrich/química , Proteína Neuronal del Síndrome de Wiskott-Aldrich/metabolismo , Animales , Secuencia de Bases , Línea Celular , Células Cultivadas , Cricetinae , Espinas Dendríticas/metabolismo , Espinas Dendríticas/ultraestructura , Expresión Génica , Técnicas de Silenciamiento del Gen , Factores de Intercambio de Guanina Nucleótido/antagonistas & inhibidores , Factores de Intercambio de Guanina Nucleótido/genética , Células HEK293 , Humanos , Modelos Neurológicos , Neuronas/ultraestructura , Dominios y Motivos de Interacción de Proteínas , ARN Interferente Pequeño/genética , Ratas , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Factores de Intercambio de Guanina Nucleótido Rho , Proteína Neuronal del Síndrome de Wiskott-Aldrich/genética
14.
J Cell Sci ; 123(Pt 10): 1742-50, 2010 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-20427313

RESUMEN

SNX18 and SNX9 are members of a subfamily of SNX (sorting nexin) proteins with the same domain structure. Although a recent report showed that SNX18 and SNX9 localize differently in cells and appear to function in different trafficking pathways, concrete evidence regarding whether they act together or separately in intracellular trafficking is still lacking. Here, we show that SNX18 has a similar role to SNX9 in endocytic trafficking at the plasma membrane, rather than having a distinct role. SNX18 and SNX9 are expressed together in most cell lines, but to a different extent. Like SNX9, SNX18 interacts with dynamin and stimulates the basal GTPase activity of dynamin. It also interacts with neuronal Wiskott-Aldrich syndrome protein (N-WASP) and synaptojanin, as does SNX9. SNX18 and SNX9 can form a heterodimer and colocalize in tubular membrane structures. Depletion of SNX18 by small hairpin RNA inhibited transferrin uptake. SNX18 successfully compensates for SNX9 deficiency during clathrin-mediated endocytosis and vice versa. Total internal reflection fluorescence microscopy in living cells shows that a transient burst of SNX18 recruitment to clathrin-coated pits coincides spatiotemporally with a burst of dynamin and SNX9. Taken together, our results suggest that SNX18 functions with SNX9 in multiple pathways of endocytosis at the plasma membrane and that they are functionally redundant.


Asunto(s)
Membrana Celular/metabolismo , Vesículas Cubiertas por Clatrina/metabolismo , Glioma/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Línea Celular Tumoral , Dinaminas/metabolismo , Endocitosis/genética , Glioma/genética , Glioma/patología , Humanos , Microscopía Fluorescente , Proteínas del Tejido Nervioso/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , Unión Proteica , Transporte de Proteínas , ARN Interferente Pequeño/genética , Nexinas de Clasificación , Proteínas de Transporte Vesicular/genética , Proteína Neuronal del Síndrome de Wiskott-Aldrich/metabolismo
15.
Mol Cells ; 45(8): 537-549, 2022 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-35950455

RESUMEN

Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-likelike 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.


Asunto(s)
Factor de Crecimiento Epidérmico , Proteínas del Tejido Nervioso , Animales , Encefalinas , Factor de Crecimiento Epidérmico/genética , Factor de Crecimiento Epidérmico/farmacología , Expresión Génica , Ratones , Células 3T3 NIH , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Precursores de Proteínas , Ratas
16.
Am J Respir Cell Mol Biol ; 44(5): 716-24, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-20639461

RESUMEN

Mucin hypersecretion is an important clinical feature of several respiratory diseases, including asthma, cystic fibrosis, nasal allergy, rhinitis, and sinusitis. It has been shown that α-melanocyte-stimulating hormone (α-MSH), a proopiomelanocortin (POMC)-derived peptide, has immunomodulatory activities by inhibiting NF-κB activation induced by proinflammatory cytokines such as TNF-α. Because MUC5AC expression is known to be up-regulated by TNF-α via NF-κB activation, we evaluated the inhibitory effect of α-MSH on MUC5AC gene expression induced by TNF-α in normal human nasal epithelial (NHNE) cells. Melanocortin-1-receptor (MC-1R) was detected by RT-PCR, Western blotting, and immunofluorescent labeling in NHNE cells. α-MSH suppressed NF-κB/p65 phosphorylation induced by TNF-α as well as IkB-α degradation in a dose-dependent manner, as assessed by Western blotting. In addition, α-MSH inhibited TNF-α-induced nuclear translocation of NF-κB and NF-κB luciferase activity. Real-time quantitative PCR data showed that α-MSH inhibited TNF-α-induced expression of MUC5AC, and this effect of α-MSH was neutralized by knockdown of MC-1R using MC-1R shRNA lentivirus. Analyses using RT-PCR and Western blotting showed the expression of POMC and two key enzymes in the POMC processing, proprotein convertases (PC)1 and PC2, and 7B2, which is required for enzymatic activity of PC2, in normal human nasal mucosa. We conclude that α-MSH down-regulates MUC5AC expression by inhibiting TNF-α-induced NF-κB activity through MC-1R stimulation in NHNE cells and that normal human nasal mucosa possesses the POMC processing machinery. Therefore, α-MSH may be a promising candidate to decrease mucin overproduction initiated by NF-κB activation.


Asunto(s)
Células Epiteliales/metabolismo , Melanocitos/metabolismo , Mucina 5AC/metabolismo , Mucosa Nasal/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Transporte Activo de Núcleo Celular , Células Epiteliales/citología , Regulación de la Expresión Génica , Humanos , Proteínas I-kappa B/metabolismo , Lentivirus/genética , Lentivirus/metabolismo , Modelos Biológicos , Mucina 5AC/antagonistas & inhibidores , Inhibidor NF-kappaB alfa , FN-kappa B/metabolismo , Proopiomelanocortina/metabolismo , Receptor de Melanocortina Tipo 1/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , alfa-MSH/metabolismo
17.
Biol Res Nurs ; 23(2): 248-257, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-32844660

RESUMEN

The prevalence of vascular dementia continues to increase with no cure. Thus, it is important identify the aggravating factors of vascular dementia to delay disease progression in patients. Obesity is a well-known risk factor for vascular dementia and causes mild cognitive impairment. In the present study, we evaluated whether obesity exacerbates cognitive impairment in vascular dementia rats and how it affects synaptic plasticity through the BDNF pathway. We randomly assigned 30 Wistar male rats to three groups: sham surgery (Sham), vascular dementia (VaD), and vascular dementia with obesity (OB + VaD). We fed rats a 60% high-fat diet to establish obesity; we then induced vascular dementia using bilateral common carotid artery occlusion. After 6 weeks, we evaluated cognitive function using the Morris water maze and radial arm maze tests. We analyzed post-synaptic density-95 (PSD95) and growth-associated protein-43 (GAP43) to confirm synaptic plasticity. We also evaluated brain-derived neurotrophic factor (BDNF), phosphorylated extracellular signal-regulated kinase (pERK), and phosphorylated cyclic adenosine monophosphate response element-binding protein (pCREB) in the hippocampus. The OB + VaD group showed the most impaired cognitive function on behavioral tests, with decreases in PSD95. The VaD group showed increased levels of BDNF, pERK, and pCREB, while the OB + VaD group displayed decreased levels. We suggest that obesity exacerbates cognitive impairment in vascular dementia by inhibiting the compensatory increases of BDNF-ERK-CREB pathway.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Disfunción Cognitiva/fisiopatología , Demencia Vascular/fisiopatología , Obesidad/fisiopatología , Animales , Disfunción Cognitiva/etiología , Disfunción Cognitiva/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Demencia Vascular/complicaciones , Demencia Vascular/metabolismo , Dieta Alta en Grasa/efectos adversos , Modelos Animales de Enfermedad , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Hipocampo/metabolismo , Masculino , Aprendizaje por Laberinto/fisiología , Plasticidad Neuronal/fisiología , Obesidad/complicaciones , Obesidad/metabolismo , Ratas , Ratas Wistar
18.
Biol Res Nurs ; 23(3): 464-470, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33406883

RESUMEN

BACKGROUND: Epigenetic age acceleration has been studied as a promising biomarker of age-related conditions, including cognitive aging. This pilot study aims to explore potential cognitive aging-related biomarkers by investigating the relationship of epigenetic age acceleration and cognitive function and by examining the epigenetic age acceleration differences between successful cognitive aging (SCA) and normal cognitive aging (NCA) among Korean community-dwelling older adults (CDOAs). METHODS: We used data and blood samples of Korean CDOAs from the Korean Frailty and Aging Cohort Study. The participants were classified into two groups, SCA (above the 50th percentile in all domains of cognitive function) and NCA. The genome-wide DNA methylation profiling array using Illumina Infinium MethylationEPIC BeadChip was used to calculate the following: the DNA methylation age, universal epigenetic age acceleration, intrinsic epigenetic age acceleration (IEAA), and extrinsic epigenetic age acceleration (EEAA). We also used Pearson correlation analysis and independent t-tests to analyze the data. RESULTS: Universal age acceleration correlated with the Frontal Assessment Battery test results (r = -0.42, p = 0.025); the EEAA correlated with the Word List Recognition test results (r = -0.41, p = 0.027). There was a significant difference between SCA and NCA groups in IEAA (p = 0.041, Cohen's d = 0.82) and EEAA (p = 0.042, Cohen's d = 0.78). CONCLUSIONS: Epigenetic age acceleration can be used as a biomarker for early detection of cognitive decline in Korean community-dwelling older adults. Large longitudinal studies are warranted.


Asunto(s)
Envejecimiento Cognitivo , Vida Independiente , Anciano , Envejecimiento/genética , Estudios de Cohortes , Metilación de ADN , Epigénesis Genética , Humanos , Proyectos Piloto , República de Corea
19.
Artículo en Inglés | MEDLINE | ID: mdl-33670149

RESUMEN

Older adults suffer from multiple symptoms, which negatively affects their health-related quality of life. The single-symptom management approach has been less than effective. The data of 2362 Korean community-dwelling older adults aged 70 and above were analyzed in the Korean Frailty and Aging Cohort Study (KFACS) study. A cluster analysis, correlation analysis, and logistic regression were used to analyze the data. We found three symptom clusters: high symptom burden (HSB, n = 1032); pain and fatigue group (PAF, n = 566); and the sleep deprivation group (SDP, n = 764). Participants in the HSB group are more likely to be of old age (OR = 1.1), be female (OR = 2.4), live in a rural area (OR = 1.4), have low physical activity (OR = 0.9), and have multiple chronic conditions (OR = 1.5). The clinical blood markers analysis showed a negative relationship among the physical health, free T4 (r = -0.083, p < 0.01) and insulin (r = -0.084, p < 0.01). The sex-specific blood markers analysis showed differences among three clusters. While free testosterone (male: r = 0.124, female: r = 0.110, p < 0.05) and dehydroepiandrosterone (DHEA) (male: r = 0.352 and female: r = 0.134, p < 0.05) were associated with physical health in the HSB group, only free testosterone was associated with mental health (male: r = -0.093, and female: r = -0.116, p < 0.05) in the SDP group. These findings suggest the potential role of the patient's sex and sex hormones in symptoms of Korean community-dwelling older adults. Understanding the symptom profiles and impact of biopsychosocial factors may enhance precision symptom management.


Asunto(s)
Fragilidad , Calidad de Vida , Anciano , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Vida Independiente , Masculino , República de Corea/epidemiología
20.
Plants (Basel) ; 10(4)2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33917273

RESUMEN

Bauhinia coccinea is a tropical woody plant widely distributed in Vietnam and Unnan in southern China. Although many studies have shown the biological activities of extracts from various other species in the genus, no studies have investigated the effects of B. coccinea extracts on biological systems. In the present study, a quantitative analysis of four marker compounds of ethanol extracts of B. coccinea branches (EEBC) was performed using the high performance liquid chromatography (HPLC)-photodiode array (PDA) method. Among gallic acid, (+)-catechin, ellagic acid, and quercitrin contained in EEBC, the most abundant compound was (+)-catechin (18.736 mg/g). In addition, we investigated the EEBC on neuroprotection, antioxidation, and Alzheimer's disease (AD) marker molecules, acetylcholinesterase (AChE), and amyloid-ß (Aß). EEBC significantly inhibited hydrogen peroxide (H2O2)-induced cell death in a HT22 neuronal cell line and increased 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl scavenging activity markedly. EEBC also inhibited AChE and Aß aggregation. Among the four compounds, gallic acid exhibited strong inhibitory effects against AChE activation. In the Aß aggregation assay, the four marker compounds exhibited inhibitory effects lower than 30%. According to the results, EEBC could exert anti-AChE activation and Aß aggregation activities based on the interactive effects of the marker compounds. Our findings suggest that EEBC are sources of therapeutic candidates for application in the development of AD medication based on AChE and Aß dual targeting.

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