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1.
BMC Med Genet ; 21(1): 66, 2020 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-32228489

RESUMEN

BACKGROUND: Ischemic Stroke (IS) is the most common neurological emergency disease and has become the second most frequent cause of death after coronary artery disease in 2015. Owing to its high fatality rate and narrow therapeutic time window, early identification and prevention of potential stroke is becoming increasingly important. METHODS: We used meta-analysis and bioinformatics mining to explore disease-related pathways and regulatory networks after combining messengerRNA (mRNA) and miRNA expression analyses. The purpose of our study was to screen for candidate target genes and microRNA(miRNA) for early diagnosis of potential stroke. RESULTS: Five datasets were collected from the Gene Expression Omnibus (GEO) database by systematical retrieval, which contained three mRNA datasets (102 peripheral blood samples in total) and two miRNA dataset (59 peripheral blood samples). Approximately 221 different expression(DE) mRNAs (155 upregulated and 66 downregulated mRNAs) and 185 DE miRNAs were obtained using the metaDE package and GEO2R tools. Further functional enrichments of DE-mRNA, DE-miRNA and protein-protein interaction (PPI) were performed and visualized using Cytoscape. CONCLUSION: Our study identified six core mRNAs and two regulated miRNAs in the pathogenesis of stroke, and we elaborated the intrinsic role of systemic lupus erythematosus (SLE) and atypical infections in stroke, which may aid in the development of precision medicine for treating ischemic stroke. However, the role of these novel biomarkers and the underlying molecular mechanisms in IS require further fundamental experiments and further clinical evidence.


Asunto(s)
Biomarcadores/análisis , Isquemia Encefálica/genética , Accidente Cerebrovascular/genética , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/epidemiología , Biología Computacional/métodos , Conjuntos de Datos como Asunto/estadística & datos numéricos , Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Estudios de Asociación Genética/estadística & datos numéricos , Humanos , MicroARNs/genética , ARN Mensajero/genética , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología
2.
Cell Mol Neurobiol ; 39(8): 1125-1137, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31256326

RESUMEN

Microglia are the inherent immune effector cells in the central nervous system (CNS), are activated rapidly when the CNS is stimulated by ischaemia, infection, injury, etc. and participate in and aggravate the development of inflammatory reactions in the CNS. During the process of microglial activation, inflammatory factors such as TNF-α and IL-1ß and an abundance of reactive oxygen species (ROS)/reactive nitrogen species (RNS), are released by damaged nerve cells. LXW7 is a small molecule peptide and specifically binds with integrin αvß3. Cerium oxide nanoparticles (nanoceria) are strong free radical scavengers and are widely used in many studies. In this research, a model of inflammation was established using lipopolysaccharide (LPS) to induce BV2 microglia activation, and the effects of CeO2@PAA (synthetic nanoscale cerium oxide particles), LXW7 and CeO2@PAA-LXW7 were evaluated. We detected the expression level of inflammatory factors, the release of NO in BV2 cells and the generation of intracellular ROS. The expression levels of focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) and their phosphorylated proteins were detected in BV2 microglia. We found that CeO2@PAA, LXW7 and CeO2@PAA-LXW7 all effectively inhibited the activation of BV2 microglia, reduced the production of cytokines and the release of NO and reduced the production of intracellular ROS. The three treatments all inhibited the phosphorylation of FAK and STAT3 in BV2 microglia. Regarding these effects, CeO2@PAA-LXW7 was more effective than the other two monotherapies. Our data indicate that CeO2@PAA, LXW7 and CeO2@PAA-LXW7 can exert a neuroprotective function by inhibiting the inflammatory response of LPS-induced BV2 microglia. LXW7 may inhibit the activation of FAK and STAT3 signals in combination with integrin αvß3 to restrain neuroinflammation and the antioxidative stress effect of cerium oxide; hence, CeO2@PAA-LXW7 can exert a more robust anti-inflammatory and neuroprotective effect via synergistically suppressing the ability of LXW7 to influence the integrin pathway and the free radical-scavenging ability of CeO2@PAA.


Asunto(s)
Resinas Acrílicas/química , Cerio/química , Inflamación/patología , Microglía/patología , Nanopartículas/química , Péptidos/farmacología , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Integrina alfaVbeta3/metabolismo , Interleucina-1beta/metabolismo , Lipopolisacáridos , Ratones , Microglía/efectos de los fármacos , Modelos Biológicos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Fosforilación/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Factor de Transcripción STAT3/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
3.
Neurochem Res ; 43(7): 1439-1453, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29882125

RESUMEN

CeO2 nanoparticles (nanoceria) have been used in many studies as a powerful free radical scavenger, and LXW7, a small-molecule peptide, can specifically target the integrin αvß3, whose neuroprotective effects have also been demonstrated. The objective of this study is to observe the neuroprotective effect and potential mechanism of CeO2@PAA-LXW7, a new compound that couples CeO2@PAA (nanoceria modified with the functional group of polyacrylic acid) with LXW7 via a series of chemical reactions, in H2O2-induced NGF-differentiated PC12 cells. We examined the effects of LXW7, CeO2@PAA, and CeO2@PAA-LXW7 on the viability of primary hippocampal neurons and found that there was no significant difference under control conditions, but increased cellular viability was observed in the case of H2O2-induced injury. We used H2O2-induced NGF-differentiated PC12 cells as the classical injury model to investigate the neuroprotective effect of CeO2@PAA-LXW7. In this study, LXW7, CeO2@PAA, and CeO2@PAA-LXW7 inhibit H2O2-induced oxidative stress by reducing the production of reactive oxygen species (ROS) and regulating Bax/Bcl-2, cleaved caspase-3 and mitochondrial cytochrome C (cyto C) in the apoptotic signaling pathways. We found that the levels of phosphorylation of focal adhesion kinase (FAK) and of signal transducer and activator of transcription 3 (STAT3) increased significantly in H2O2-induced NGF-differentiated PC12 cells, whereas LXW7, CeO2@PAA, and CeO2@PAA-LXW7 suppressed the increase to different degrees. Among the abovementioned changes, the inhibitory effect of CeO2@PAA-LXW7 on H2O2-induced changes, including the increases in the levels of p-FAK and p-STAT3, is more obvious than that of LXW7 or CeO2@PAA alone. In summary, these results suggest that integrin signaling participates in the regulation of apoptosis via the regulation of ROS and of the apoptosis pathway in H2O2-induced NGF-differentiated PC12 cells. LXW7, CeO2@PAA, and CeO2@PAA-LXW7 can play neuroprotective roles by counteracting the oxidative stress and apoptosis induced by H2O2 in NGF-differentiated PC12 cells. CeO2@PAA-LXW7 exerting a more powerful synergistic effect via the conjunction of LXW7 and CeO2@PAA.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Factor de Crecimiento Nervioso/metabolismo , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Resinas Acrílicas , Animales , Cerio , Peróxido de Hidrógeno/farmacología , Neuronas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Células PC12 , Péptidos , Ratas , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos
4.
Front Neurol ; 13: 1007702, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36457862

RESUMEN

Objective: The aim of the study was to evaluate non-invasive brain stimulation (NIBS) [including transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES)] on neurological symptoms in patients with multiple sclerosis (PwMS). Method: We searched PubMed, Embase, Cochrane Library, Web of Science and Ovid MEDLINE until February 2022. And we evaluated the included studies for methodological quality by the Cochrane bias risk assessment tool and assessed the studies' certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. We performed network meta analysis (NMA) by using Stata 15 and ranked the results of the NMA by using the surface under the cumulative ranking curve (SUCRA) ranking chart. Result: Twenty seven clinical trials were finally included (N = 596, 66.4% women). For the immediate effects, rTMS over M1 yielded the most optimal scheme for fatigue reduction among all the interventions compared to the sham stimulation groups [MD = -0.85, 95% CI (-1.57, -0.14)] (SUCRA = 82.6%). iTBS over M1 yielded the most signifcant reduced pain level than the sham groups did [MD = -1.26, 95% CI (-2.40, -0.11)] (SUCRA = 98.4%). tDCS over F3 was the best protocol of NIBS to improve quality of life (QOL) [MD = 1.41, 95% CI = (0.45,2.36)] (SUCRA = 76.7%), and iTBS over M1 may significantly reduce spasticity compared to sham stimulation [MD = -1.20, 95% CI = (-1.99, -0.41)] (SUCRA = 90.3%). Furthermore, rTMS, tRNS, and tDCS on certain areas may improve PwMS accuracy, response time, manual dexterity, pain relief and QOL, but does not show statistically significant differences. The evidence assessed using GRADE is very low. Conclusion: Based on the NMA and SUCRA ranking, we can conclude that symptoms including fatigue, pain, spasticity, and QOL can be improved by following NIBS protocol after treatment. Nonetheless, most of the included studies lack a good methodology, and more high-quality randomized clinical trials are needed.

5.
Biomark Med ; 15(8): 585-595, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33988461

RESUMEN

Aim: In this study, we aimed to identify potential diagnostic biomarkers Parkinson's disease (PD) by exploring microarray gene expression data of PD patients. Materials & methods: Differentially expressed genes associated with PD were screened from the GSE99039 dataset using weighted gene co-expression network analysis, followed by gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, gene-gene interaction network analysis and receiver operator characteristics analysis. Results: We identified two PD-associated modules, in which genes from the chemokine signaling pathway were primarily enriched. In particular, CS, PRKCD, RHOG and VAMP2 directly interacted with known PD-associated genes and showed higher expression in the PD samples, and may thus be potential biomarkers in PD diagnosis. Conclusion: A DFG-analysis identified a four-gene panel (CS, PRKCD, RHOG, VAMP2) as a potential diagnostic predictor to diagnose PD.


Asunto(s)
Biomarcadores/análisis , Ontología de Genes , Redes Reguladoras de Genes , Genómica/métodos , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Mapas de Interacción de Proteínas , Estudios de Casos y Controles , Perfilación de la Expresión Génica , Humanos , Transducción de Señal
6.
Int Immunopharmacol ; 77: 105963, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31732449

RESUMEN

Microglia activation is closely linked to ischemia, various chronic neurodegenerative diseases (e.g., Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis), and many other central nervous system diseases. Accumulating evidence suggests that depressing the microglial inflammatory response could be an effective treatment for inflammatory disorders. The integrin αvß3 inhibitor LXW7 has a neuroprotective effect; however, its anti-inflammatory effects and underlying mechanism remain unclear. Thus, we examined whether LXW7 would inhibit inflammatory cytokines and mediators, and we evaluated the potential mechanisms of its neuroprotective effects. Nitrite analysis revealed LXW7 reduced the nitric oxide (NO) level. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) suggested that LXW7 suppressed the expression of proinflammatory genes for tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1ß), inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and anti-inflammatory gene interleukin 10 (IL-10) at the messenger ribonucleic acid level. Enzyme-linked immunosorbent assay results demonstrated that LXW7 treatment reduced the expression of prostaglandin E2 (PGE2), TNF-α, IL-1ß and IL-10 at the protein level. Western blotting was conducted to confirm the upregulation of inflammatory factors, including iNOS and COX-2 at the protein level. LXW7 inhibited major genes in the Akt/NF-κB and c-Jun NH2-terminal kinase/ mitogen-activated protein kinases (JNK/MAPK) signaling pathways. Immunofluorescence revealed that LXW7 inhibited the nuclear translocation of nuclear factor kappa B (NF-κB). Thus, LXW7 effectively alleviated LPS-induced inflammatory damage and had neuroprotective effects. The anti-inflammatory effects of LXW7 may be associated with the inhibition of microglial activation via Akt/NF-κB and JNK/MAPK signaling pathways by blocking integrin αvß3 receptor. The present study's findings suggest that LXW7 has a substantial therapeutic potential for treating inflammatory and neurodegenerative diseases.


Asunto(s)
Antiinflamatorios/farmacología , Inflamación/tratamiento farmacológico , Microglía/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Línea Celular , Citocinas/metabolismo , Inflamación/metabolismo , Mediadores de Inflamación/metabolismo , Lipopolisacáridos/farmacología , Ratones , Microglía/metabolismo , Sustancias Protectoras/farmacología , Regulación hacia Arriba/efectos de los fármacos
7.
J Immunol Res ; 2019: 7430780, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31049359

RESUMEN

OBJECTIVE: Systemic lupus erythematosus (SLE) is an immune disease characterized by multiorgan involvement. Neuropsychiatric systemic lupus erythematosus (NPSLE) is one of the most devastating complications of SLE, which lacks efficient diagnostic biomarkers. The recent studies on the anti-GAPDH autoantibodies suggested its potential pathogenic roles in NPSLE. However, the clinical relevance of the anti-GAPDH autoantibodies in patients with SLE is still elusive. In this study, we sought to determine the serum levels of the anti-GAPDH autoantibodies in patients with SLE to investigate the clinical significance of the anti-GAPDH autoantibodies in SLE. METHODS: Concentrations of the glyceraldehyde 3-phosphate dehydrogenase autoantibodies (anti-GAPDH autoantibodies) in the serum of 130 SLE patients and 55 healthy individuals were determined by enzyme-linked immunosorbent assay (ELISA). Among the 130 SLE patients, 95 were SLE patients without neuropsychiatric symptoms and 35 had NPSLE. White blood cell (WBC) count, hemoglobin (HB), platelet count (PLT), IgG, IgA, IgM, anti-dsDNA, C3, C4, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), RF, anti-cardiolipin (Acl), ANA, AnuA, anti-SSA, anti-SSB, ß2-GPI, urinalysis, and 24 h urine protein were measured by standard laboratory techniques. Systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) and Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index scores were evaluated accordingly. RESULTS: The serum levels of the anti-GAPDH autoantibodies were significantly elevated in the SLE patients, especially in the patients with NPSLE (P = 0.0011). Elevated serum anti-GAPDH was correlated with increased SLEDAI-2K (P = 0.017), ESR, IgG, and IgM and associated with increased intracranial pressure and incidence of cerebrovascular lesions, but it was protective for seizure disorder incidence. CONCLUSIONS: Serum anti-GAPDH autoantibody was increased in both groups of SLE patients with or without neuropsychiatric symptoms and associated with disease severity. It could become an indicator of tissue damages in the brain for the future clinical practice.


Asunto(s)
Autoanticuerpos/inmunología , Gliceraldehído-3-Fosfato Deshidrogenasa (Fosforilante)/inmunología , Presión Intracraneal , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/inmunología , Adulto , Autoanticuerpos/sangre , Sedimentación Sanguínea , Proteína C-Reactiva/análisis , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Vasculitis por Lupus del Sistema Nervioso Central/inmunología , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Adulto Joven
8.
J Cancer ; 9(13): 2341-2348, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30026830

RESUMEN

The impact of albumin to globulin ratio (AGR) on the prognosis of various human cancers has not been well established. Here, a systemic review and meta-analysis has been performed to comprehensively assess the relationships between AGR and lymph node metastasis (LNM) or overall survival (OS). Systematical search through six electronic databases has been carried out to identify reports involving the role of AGR on OS and LNM in human cancers. Hazard ratio (HR), odd ratio (OR) and their 95% confidence intervals (95% CI) were evaluated through meta-analysis according to standard steps. Of 403 studies retrieved, 14 eligible studies with 4136 patients were included in this study. The analysis based on random-effect model demonstrated that low AGR was significantly associated with poor OS in various cancers (HR=1.87, 95% CI 1.50-2.34; P < 0.001). Subsequent results showed a significant increase in the risk of LNM in the low AGR group when compared with high AGR group (HR=2.24; 95% CI=1.49-3.36; P<0.001). To conclusion, this study suggested that AGR was associated with OS and LNM in cancer patients and AGR may be a potential marker to assess prognosis of cancer patients. However, a large scale of samples and prospective studies are needed in the future to validate the role of AGR in practice.

9.
Front Aging Neurosci ; 10: 178, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29967579

RESUMEN

Parkinson's disease (PD) is a quite common neurodegenerative disorder with a prevalence of approximately 1:800-1,000 in subjects over 60 years old. The aim of our study was to determine the candidate target genes in PD through meta-analysis of multiple gene expression arrays datasets and to further combine mRNA and miRNA expression analyses to identify more convincing biological targets and their regulatory factors. Six included datasets were obtained from the Gene Expression Omnibus database by systematical search, including five mRNA datasets (150 substantia nigra samples in total) and one miRNA dataset containing 32 peripheral blood samples. A chip meta-analysis of five microarray data was conducted by using the metaDE package and 94 differentially expressed (DE) mRNAs were comprehensively obtained. And 19 deregulated DE miRNAs were obtained through the analysis of one miRNAs dataset by Qlucore Omics Explorer software. An interaction network formed by DE mRNAs, DE miRNAs, and important pathways was discovered after we analyzed the functional enrichment, protein-protein interactions, and miRNA targetome prediction analysis. In conclusion, this study suggested that five significantly downregulated mRNAs (MAPK8, CDC42, NDUFS1, COX4I1, and SDHC) and three significantly downregulated miRNAs (miR-126-5p, miR-19-3p, and miR-29a-3p) were potentially useful diagnostic markers in clinic, and lipid metabolism (especially non-alcoholic fatty liver disease pathway) and mitochondrial dysregulation may be the keys to biochemically detectable molecular defects. However, the role of these new biomarkers and molecular mechanisms in PD requires further experiments in vivo and in vitro and further clinical evidence.

10.
Oncotarget ; 6(29): 28502-12, 2015 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-26143635

RESUMEN

BACKGROUND: Several recent randomized clinical trials have preliminarily demonstrated that initial targeted therapy with combined BRAF and MEK inhibition is more effective in metastatic melanoma (MM) than single agent. To guide therapeutic decisions, we did a comprehensive network meta-analysis to identify evidence to robustly support whether combined BRAF and MEK inhibition is the best initial targeted therapeutic strategy for patients with MM. METHODS: The databases of PubMed and trial registries were researched for randomized clinical trials of targeted therapy. Data of outcome were extracted on progression-free survival (PFS), objective response rate (ORR), and overall survival (OS). Network meta-analysis using a Bayesian statistical model was performed to evaluate relative hazard ratio (HR) for PFS and OS, odds ratio (OR) for ORR. RESULTS: Finally, 16 eligible trials comprising 5976 participants were included in this meta-analysis. PFS were significantly prolonged in patients who received combined BRAF-MEK inhibition compared with those who received BRAF inhibition (HR: 0.58, 95%CI: 0.51-0.67, P < 0.0001) or MEK inhibition alone (HR: 0.29, 95%CI: 0.22-0.37, P < 0.0001). Combined BRAF-MEK inhibition also improved the OS over BRAF inhibition (HR: 0.67, 95%CI: 0.56-0.81, P < 0.0001) or MEK inhibition alone (HR: 0.48, 95%CI: 0.36-0.65, P < 0.0001). The ORR was superior in combined BRAF and MEK inhibition comparing with BRAF inhibition (OR: 2.00, 95%CI: 1.66-2.44, P < 0.0001) or MEK inhibition alone (OR: 20.66, 95%CI: 12.22-35.47, P < 0.0001). CONCLUSIONS: This study indicates that concurrent inhibition of BRAF and MEK improved the most effective therapeutic modality as compared as single BRAF or MEK inhibition for patients with MM.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Melanoma/tratamiento farmacológico , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Proto-Oncogénicas B-raf/antagonistas & inhibidores , Teorema de Bayes , Supervivencia sin Enfermedad , Humanos , Melanoma/metabolismo , Melanoma/patología , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Terapia Molecular Dirigida/métodos , Metástasis de la Neoplasia , Inhibidores de Proteínas Quinasas/administración & dosificación , Proteínas Proto-Oncogénicas B-raf/metabolismo , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento
11.
Brain Res Mol Brain Res ; 103(1-2): 91-105, 2002 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-12106695

RESUMEN

The expression level of the neuronal-specific K-Cl cotransporter KCC2 (SLC12A5) is a major determinant of whether neurons will respond to GABA with a depolarizing, excitatory response or a hyperpolarizing, inhibitory response. In view of the potential role in human neuronal excitability we have characterized the hKCC2 cDNA and gene. The 5.9 kb hKCC2 transcript is specific to brain, and is induced during in vitro differentiation of NT2 teratocarcinoma cells into neuronal NT2-N cells. The 24-exon SLC12A5 gene is on human chromosome 20q13, and contains a polymorphic dinucleotide repeat within intron 1 near a potential binding site for neuron-restrictive silencing factor. Expression of hKCC2 cRNA in Xenopus laevis oocytes results in significant Cl(-)-dependent (86)Rb(+) uptake under isotonic conditions; cell swelling under hypotonic conditions causes a 20-fold activation, which is blocked by the protein phosphatase inhibitor calyculin-A. In contrast, oocytes expressing mouse KCC4 do not mediate isotonic K-Cl cotransport but express much higher absolute transport activity than KCC2 oocytes under hypotonic conditions. Initial and steady state kinetics of hKCC2-injected oocytes were performed in both isotonic and hypotonic conditions, revealing K(m)s for K(+) and Cl(-) of 9.3+/-1.8 mM and 6.8+/-0.9 mM, respectively; both affinities are significantly higher than KCC1 and KCC4. The K(m) for Cl(-) is close to the intracellular Cl(-) activity of mature neurons, as befits a neuronal efflux mechanism.


Asunto(s)
Neuronas/metabolismo , Simportadores/genética , Simportadores/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Clonación Molecular , Exones , Expresión Génica , Humanos , Soluciones Hipotónicas/farmacología , Intrones , Soluciones Isotónicas/farmacología , Datos de Secuencia Molecular , Oocitos/fisiología , Polimorfismo Genético , Radioisótopos de Rubidio , Venas Umbilicales/citología , Xenopus laevis , Cotransportadores de K Cl
12.
Am J Physiol Renal Physiol ; 283(4): F826-38, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12217875

RESUMEN

We report the molecular and functional characterization of murine Slc26a6, the putative apical chloride-formate exchanger of the proximal tubule. The Slc26a6 transcript is expressed in several tissues, including kidney. Alternative splicing of the second exon generates two distinct isoforms, denoted Slc26a6a and Slc26a6b, which differ in the inclusion of a 23-residue NH(2)-terminal extension. Functional comparison with murine Slc26a1, the basolateral oxalate exchanger of the proximal tubule, reveals a number of intriguing differences. Whereas Slc26a6 is capable of Cl(-), SO, formate, and oxalate uptake when expressed in Xenopus laevis oocytes, Slc26a1 transports only SO and oxalate. Measurement of intracellular pH during the removal of extracellular Cl(-) in the presence and absence of HCO indicates that Slc26a6 functions as both a Cl(-)/HCO and a Cl(-)/OH(-) exchanger; simultaneous membrane hyperpolarization during these experimental maneuvers reveals that HCO and OH(-) transport mediated by Slc26a6 is electrogenic. Cis-inhibition and efflux experiments indicate that Slc26a6 can mediate the exchange of both Cl(-) and SOwith a number of substrates, including formate and oxalate. In contrast, SO and oxalate transport by Slc26a1 are mutually cis-inhibited but activated significantly by extracellular halides, lactate, and formate. The data indicate that Slc26a6 encodes an apical Cl(-)/formate/oxalate and Cl(-)/base exchanger and reveal significant mechanistic differences between apical and basolateral oxalate exchangers of the proximal tubule.


Asunto(s)
Antiportadores/química , Antiportadores/metabolismo , Concentración de Iones de Hidrógeno , Túbulos Renales Proximales/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Transporte de Anión , Antiportadores/genética , Secuencia de Bases , Northern Blotting , Cloruros/metabolismo , Cromosomas/química , Cromosomas/genética , Electrofisiología , Cinética , Ratones , Datos de Secuencia Molecular , Oocitos/metabolismo , Transportadores de Sulfato , Sulfatos/metabolismo , Xenopus laevis
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