Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Int. j. high dilution res ; 21(2): 4-4, May 6, 2022.
Artigo em Inglês | LILACS, HomeoIndex - Homeopatia | ID: biblio-1396752

RESUMO

The purpose of the research is to studythe efficacy of phytotherapeutic, and homeopathic drugs. Phytotherapeutic drugs have been widely used in parasitology for many years. Also, homeopathic drugs such as Cina have anti-helminthicproperties. The possibility of using phytotherapeutic and high dilutiondrugs during the treatment of nematodedisease has been studied. Two experimental parasitological disease models (aspiculuriosis and trichinellosis) were used.Trichinellosisis a common model of nematodesinmice [1,2].Aspiculuris tetrapteraa pinworm of mice is an important parasite in institutions with mice colonies for both research and teaching purposes. The infection is generally asymptomatic. This study aimed to assess the protective efficiency of a homeopathic drug such as Cina C6cH, sphagnum,and its complex against experimental trichinosis and aspiculuriosis. Methods:An assay was carried out on 80 white outbred mice. These were divided into 6 groups of ten mice each. Groups1 and 4 had sphagnum q.s. per os; groups2 and 5 -desoldering dissolved in water Cina C6cH one time a day per os, the groups3 and 6 received complex sphagnum+Cina C6cHone time a day per os. Groups1-3 were inoculated with a dose of 80 ± 5 units of T. spiralislarva per mouse, groups 4-6 had spontaneous aspiculuriosis, and group 7 had T. spiralis, group 8 had Aspiculuris tetraptera. After 60 days of trichinellosis incubation, process the mice were euthanized and dissected for evaluation.Results:Maximum protection was obtained in the group of mice 3: T. spiralisdetected larvae in animals was 650.5±25.1 larva/animal. Group N2 (Cina C6cH) presented 2840.5±183.3 larva/animal. This was less than the control group (4485±430.6 larva/mouse). Also,groups 4-6 of mice with aspiculuriosis showed 75%, 80%,and 86% efficacy against nematodes.


Assuntos
Cina maritima , Trichinella spiralis , Fitoterapia
2.
Pediatr Nephrol ; 36(9): 2747-2757, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33646395

RESUMO

BACKGROUND: The G1 and G2 alleles of apolipoprotein L1 (APOL1) are common in the Black population and associated with increased risk of focal segmental glomerulosclerosis (FSGS). The molecular mechanisms linking APOL1 risk variants with FSGS are not clearly understood, and APOL1's natural absence in laboratory animals makes studying its pathobiology challenging. METHODS: In a cohort of 90 Black patients with either FSGS or minimal change disease (MCD) enrolled in the Nephrotic Syndrome Study Network (58% pediatric onset), we used kidney biopsy traits as an intermediate outcome to help illuminate tissue-based consequences of APOL1 risk variants and expression. We tested associations between APOL1 risk alleles or glomerular APOL1 mRNA expression and 83 light- or electron-microscopy traits measuring structural and cellular kidney changes. RESULTS: Under both recessive and dominant models in the FSGS patient subgroup (61%), APOL1 risk variants were significantly correlated (defined as FDR <0.1) with decreased global mesangial hypercellularity, decreased condensation of cytoskeleton, and increased tubular microcysts. No significant correlations were detected in MCD cohort. Independent of risk alleles, glomerular APOL1 expression in FSGS patients was not correlated with morphologic features. CONCLUSIONS: While APOL1-associated FSGS is associated with two risk alleles, both one and two risk alleles are associated with cellular/tissue changes in this study of FSGS patients. Our lack of discovery of a large group of tissue differences in FSGS and no significant difference in MCD may be due to the lack of power but also supports investigating whether machine learning methods may more sensitively detect APOL1-associated changes.


Assuntos
Apolipoproteína L1/genética , Glomerulosclerose Segmentar e Focal , Alelos , Genótipo , Glomerulosclerose Segmentar e Focal/genética , Humanos , Síndrome Nefrótica/genética
4.
Kidney360 ; 1(12): 1345-1352, 2020 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-35372895

RESUMO

Background: The COVID-19 pandemic strained hospital resources in New York City, including those for providing dialysis. New York University Medical Center and affiliations, including New York City Health and Hospitals/Bellevue, developed a plan to offset the increased needs for KRT. We established acute peritoneal dialysis (PD) capability, as usual dialysis modalities were overwhelmed by COVID-19 AKI. Methods: Observational study of patients requiring KRT admitted to Bellevue Hospital during the COVID surge. Bellevue Hospital is one of the largest public hospitals in the United States, providing medical care to an underserved population. There were substantial staff, supplies, and equipment shortages. Adult patients admitted with AKI who required KRT were considered for PD. We rapidly established an acute PD program. A surgery team placed catheters at the bedside in the intensive care unit; a nephrology team delivered treatment. We provided an alternative to hemodialysis and continuous venovenous hemofiltration for treating patients in the intensive-care unit, demonstrating efficacy with outcomes comparable to standard care. Results: From April 8, 2020 to May 8, 2020, 39 catheters were placed into ten women and 29 men. By June 10, 39% of the patients started on PD recovered kidney function (average ages 56 years for men and 59.5 years for women); men and women who expired were an average 71.8 and 66.2 years old. No episodes of peritonitis were observed; there were nine incidents of minor leaking. Some patients were treated while ventilated in the prone position. Conclusions: Demand compelled us to utilize acute PD during the COVID-19 pandemic. Our experience is one of the largest recently reported in the United States of which we are aware. Acute PD provided lifesaving care to acutely ill patients when expanding current resources was impossible. Our experience may help other programs to avoid rationing dialysis treatments in health crises.


Assuntos
Injúria Renal Aguda , COVID-19 , Diálise Peritoneal , Injúria Renal Aguda/epidemiologia , Adulto , COVID-19/epidemiologia , Feminino , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Pandemias , Diálise Peritoneal/efeitos adversos , Diálise Renal , SARS-CoV-2 , Estados Unidos
5.
J Am Soc Nephrol ; 29(11): 2745-2754, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30361325

RESUMO

BACKGROUND: We evaluated and compared the effects of sparsentan, a dual endothelin type A (ETA) and angiotensin II type 1 receptor antagonist, with those of the angiotensin II type 1 receptor antagonist irbesartan in patients with primary FSGS. METHODS: In this phase 2, randomized, double-blind, active-control Efficacy and Safety of Sparsentan (RE-021), a Dual Endothelin Receptor and Angiotensin Receptor Blocker, in Patients with Focal Segmental Glomerulosclerosis (FSGS): A Randomized, Double-blind, Active-Control, Dose-Escalation Study (DUET), patients aged 8-75 years with biopsy-proven FSGS, eGFR>30 ml/min per 1.73 m2, and urinary protein-to-creatinine ratio (UP/C) ≥1.0 g/g received sparsentan (200, 400, or 800 mg/d) or irbesartan (300 mg/d) for 8 weeks, followed by open-label sparsentan only. End points at week 8 were reduction from baseline in UP/C (primary) and proportion of patients achieving FSGS partial remission end point (FPRE) (UP/C: ≤1.5 g/g and >40% reduction [secondary]). RESULTS: Of 109 patients randomized, 96 received study drugs and had baseline and week 8 UP/C measurements. Sparsentan-treated patients had greater reductions in UP/C than irbesartan-treated patients did when all doses (45% versus 19%; P=0.006) or the 400 and 800 mg doses (47% versus 19%; P=0.01) were pooled for analysis. The FSGS partial remission end point was achieved in 28% of sparsentan-treated and 9% of irbesartan-treated patients (P=0.04). After 8 weeks of treatment, BP was reduced with sparsentan but not irbesartan, and eGFR was stable with both treatments. Overall, the incidence of adverse events was similar between groups. Hypotension and edema were more common among sparsentan-treated patients but did not result in study withdrawals. CONCLUSIONS: Patients with FSGS achieved significantly greater reductions in proteinuria after 8 weeks of sparsentan versus irbesartan. Sparsentan was safe and well tolerated.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Antagonistas do Receptor de Endotelina A/uso terapêutico , Glomerulosclerose Segmentar e Focal/tratamento farmacológico , Compostos de Espiro/uso terapêutico , Sulfonamidas/uso terapêutico , Adolescente , Adulto , Idoso , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/efeitos adversos , Criança , Creatinina/urina , Relação Dose-Resposta a Droga , Método Duplo-Cego , Antagonistas do Receptor de Endotelina A/administração & dosagem , Antagonistas do Receptor de Endotelina A/efeitos adversos , Feminino , Glomerulosclerose Segmentar e Focal/urina , Humanos , Irbesartana/administração & dosagem , Irbesartana/efeitos adversos , Irbesartana/uso terapêutico , Masculino , Pessoa de Meia-Idade , Proteinúria/tratamento farmacológico , Proteinúria/urina , Compostos de Espiro/administração & dosagem , Compostos de Espiro/efeitos adversos , Sulfonamidas/administração & dosagem , Sulfonamidas/efeitos adversos , Adulto Jovem
6.
Clin J Am Soc Nephrol ; 11(1): 81-9, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26656320

RESUMO

BACKGROUND AND OBJECTIVES: This analysis from the Nephrotic Syndrome Study Network (NEPTUNE) assessed the phenotypic and pathology characteristics of proteinuric patients undergoing kidney biopsy and defined the frequency and factors associated with complete proteinuria remission (CRever). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We enrolled adults and children with proteinuria ≥0.5 g/d at the time of first clinically indicated renal biopsy at 21 sites in North America from April 2010 to June 2014 into a prospective cohort study. NEPTUNE central pathologists assigned participants to minimal-change disease (MCD), FSGS, membranous nephropathy, or other glomerulopathy cohorts. Outcome measures for this analysis were (1) CRever with urine protein-to-creatinine ratio (UPC) <0.3 g/g with preserved native kidney function and (2) ESRD. Continuous variables are reported as median and interquartile range (IQR; 25th, 75th percentile). Cox proportional hazards modeling was used to assess factors associated with CRever. RESULTS: We enrolled 441 patients: 116 (27%) had MCD, 142 (32%) had FSGS, 66 (15%) had membranous nephropathy, and 117 (27%) had other glomerulopathy. The baseline UPC was 4.1 g/g (IQR, 1.9, 7.7) and the eGFR was 81 ml/min per 1.73 m(2) (IQR, 50, 105). Median duration of observation was 19 months (IQR, 11, 30). CRever occurred in 46% of patients, and 4.6% progressed to ESRD. Multivariate analysis demonstrated that higher prebiopsy proteinuria (hazard ratio, 0.3; 95% confidence interval, 0.2 to 0.5) and pathology diagnosis (FSGS versus MCD; hazard ratio, 0.2; 95% confidence interval, 0.1 to 0.5) were inversely associated with CRever. The effect of immunosuppressive therapy on remission varied by pathology diagnosis. CONCLUSIONS: In NEPTUNE, the high frequency of other pathology in proteinuric patients affirms the value of the diagnostic kidney biopsy. Clinical factors, including level of proteinuria before biopsy, pathology diagnosis, and immunosuppression, are associated with complete remission.


Assuntos
Síndrome Nefrótica/fisiopatologia , Proteinúria/fisiopatologia , Adolescente , Adulto , Biópsia , Estudos de Coortes , Feminino , Taxa de Filtração Glomerular , Humanos , Rim/patologia , Falência Renal Crônica/etiologia , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/complicações , Síndrome Nefrótica/tratamento farmacológico , Síndrome Nefrótica/patologia , Avaliação de Resultados em Cuidados de Saúde , Modelos de Riscos Proporcionais , Estudos Prospectivos , Indução de Remissão
7.
Kidney Int ; 83(4): 749-56, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23325076

RESUMO

The Nephrotic Syndrome Study Network (NEPTUNE) is a North American multicenter collaborative consortium established to develop a translational research infrastructure for nephrotic syndrome. This includes a longitudinal observational cohort study, a pilot and ancillary study program, a training program, and a patient contact registry. NEPTUNE will enroll 450 adults and children with minimal change disease, focal segmental glomerulosclerosis, and membranous nephropathy for detailed clinical, histopathological, and molecular phenotyping at the time of clinically indicated renal biopsy. Initial visits will include an extensive clinical history, physical examination, collection of urine, blood and renal tissue samples, and assessments of quality of life and patient-reported outcomes. Follow-up history, physical measures, urine and blood samples, and questionnaires will be obtained every 4 months in the first year and biannually, thereafter. Molecular profiles and gene expression data will be linked to phenotypic, genetic, and digitalized histological data for comprehensive analyses using systems biology approaches. Analytical strategies were designed to transform descriptive information to mechanistic disease classification for nephrotic syndrome and to identify clinical, histological, and genomic disease predictors. Thus, understanding the complexity of the disease pathogenesis will guide further investigation for targeted therapeutic strategies.


Assuntos
Glomerulonefrite , Nefrose Lipoide , Síndrome Nefrótica , Projetos de Pesquisa , Pesquisa Translacional Biomédica/métodos , Adulto , Fatores Etários , Biópsia , Criança , Comportamento Cooperativo , Genótipo , Glomerulonefrite/epidemiologia , Glomerulonefrite/genética , Glomerulonefrite/patologia , Glomerulonefrite/terapia , Glomerulonefrite Membranosa/epidemiologia , Glomerulonefrite Membranosa/genética , Glomerulonefrite Membranosa/patologia , Glomerulonefrite Membranosa/terapia , Glomerulosclerose Segmentar e Focal/epidemiologia , Glomerulosclerose Segmentar e Focal/genética , Glomerulosclerose Segmentar e Focal/patologia , Glomerulosclerose Segmentar e Focal/terapia , Humanos , Estudos Longitudinais , Nefrose Lipoide/epidemiologia , Nefrose Lipoide/genética , Nefrose Lipoide/patologia , Nefrose Lipoide/terapia , Síndrome Nefrótica/epidemiologia , Síndrome Nefrótica/genética , Síndrome Nefrótica/patologia , Síndrome Nefrótica/terapia , América do Norte/epidemiologia , Fenótipo , Projetos Piloto , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Sistema de Registros , Fatores de Risco , Inquéritos e Questionários , Biologia de Sistemas , Fatores de Tempo
8.
Kidney Int ; 80(7): 719-30, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21544061

RESUMO

Micro-RNAs (miRNAs) are short (average 22 nucleotides) noncoding regulatory RNAs that inhibit gene expression by targeting complementary 3'-untranslated regions of protein-encoding mRNAs for translational repression or degradation. miRNAs play key roles in both the function and differentiation of many cell types. Drosha and Dicer, two RNAase III enzymes, function in a stepwise manner to generate a mature miRNA. Previous studies have shown that podocyte-specific deletion of Dicer during development results in proteinuric renal disease and collapsing glomerulopathy (CG); however, Dicer has functions other than the generation of miRNAs. Here we found that the podocyte-specific deletion of Drosha results in a similar phenotype to Dicer mutants, confirming that the Dicer mutant phenotype is due to the loss of miRNAs. Moreover, the inducible deletion of Drosha in 2- to 3-month-old mice (Tet-On system) resulted in CG. Thus, continuous generation of miRNAs are required for the normal function of mature podocytes and their loss leads to CG. Identifying these miRNAs may provide new insight into disease pathogenesis and novel therapeutic targets in various podocytopathies.


Assuntos
Nefropatias/genética , MicroRNAs/genética , Podócitos/metabolismo , Ribonuclease III/genética , Animais , Apoptose , Biomarcadores/metabolismo , Desdiferenciação Celular , Diferenciação Celular , Proliferação de Células , RNA Helicases DEAD-box/deficiência , RNA Helicases DEAD-box/genética , Nefropatias/patologia , Camundongos , Camundongos Knockout , Camundongos Mutantes , MicroRNAs/metabolismo , Podócitos/patologia , Ribonuclease III/deficiência
9.
J Biol Chem ; 285(50): 38765-71, 2010 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-20884616

RESUMO

Nucleoside diphosphate kinases (NDPKs) are encoded by the Nme (non-metastatic cell) gene family. Although they comprise a family of 10 genes, NDPK-A and -B are ubiquitously expressed and account for most of the NDPK activity. We previously showed that NDPK-B activates the K(+) channel KCa3.1 via histidine phosphorylation of the C terminus of KCa3.1, which is required for T cell receptor-stimulated Ca(2+) flux and proliferation of activated naive human CD4 T cells. We now report the phenotype of NDPK-B(-/-) mice. NDPK-B(-/-) mice are phenotypically normal at birth with a normal life span. Although T and B cell development is normal in NDPK-B(-/-) mice, KCa3.1 channel activity and cytokine production are markedly defective in T helper 1 (Th1) and Th2 cells, whereas Th17 function is normal. These findings phenocopy studies in the same cells isolated from KCa3.1(-/-) mice and thereby support genetically that NDPK-B functions upstream of KCa3.1. NDPK-A and -B have been linked to an astonishing array of disparate cellular and biochemical functions, few of which have been confirmed in vivo in physiological relevant systems. NDPK-B(-/-) mice will be an essential tool with which to definitively address the biological functions of NDPK-B. Our finding that NDPK-B is required for activation of Th1 and Th2 CD4 T cells, together with the normal overall phenotype of NDPK-B(-/-) mice, suggests that specific pharmacological inhibitors of NDPK-B may provide new opportunities to treat Th1- and Th2-mediated autoimmune diseases.


Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Nucleosídeo NM23 Difosfato Quinases/genética , Potássio/química , Linfócitos T/metabolismo , Animais , Linfócitos T CD4-Positivos/metabolismo , Citometria de Fluxo , Histidina Quinase , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Técnicas de Patch-Clamp , Proteínas Quinases/metabolismo , Transdução de Sinais , Linfócitos T/citologia
10.
Proc Natl Acad Sci U S A ; 107(4): 1541-6, 2010 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-20080610

RESUMO

The calcium-activated K(+) channel KCa3.1 plays an important role in T lymphocyte Ca(2+) signaling by helping to maintain a negative membrane potential, which provides an electrochemical gradient to drive Ca(2+) influx. To assess the role of KCa3.1 channels in lymphocyte activation in vivo, we studied T cell function in KCa3.1(-/-) mice. CD4 T helper (i.e., Th0) cells isolated from KCa3.1(-/-) mice lacked KCa3.1 channel activity, which resulted in decreased T cell receptor-stimulated Ca(2+) influx and IL-2 production. Although loss of KCa3.1 did not interfere with CD4 T cell differentiation, both Ca(2+) influx and cytokine production were impaired in KCa3.1(-/-) Th1 and Th2 CD4 T cells, whereas T-regulatory and Th17 function were normal. We found that inhibition of KCa3.1(-/-) protected mice from developing severe colitis in two mouse models of inflammatory bowel disease, which were induced by (i) the adoptive transfer of mouse naïve CD4 T cells into rag2(-/-) recipients and (ii) trinitrobenzene sulfonic acid. Pharmacologic inhibitors of KCa3.1 have already been shown to be safe in humans. Thus, if these preclinical studies continue to show efficacy, it may be possible to rapidly test whether KCa3.1 inhibitors are efficacious in patients with inflammatory bowel diseases such as Crohn's disease and ulcerative colitis.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Colite/imunologia , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/imunologia , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular , Células Cultivadas , Colite/genética , Colite/metabolismo , Colite/patologia , Citocinas/biossíntese , Citocinas/imunologia , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/imunologia , Modelos Animais de Doenças , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo
11.
Mol Biol Cell ; 20(17): 3783-91, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19587117

RESUMO

The Ca(2+)-activated K(+) channel KCa3.1 is required for Ca(2+) influx and the subsequent activation of T-cells. We previously showed that nucleoside diphosphate kinase beta (NDPK-B), a mammalian histidine kinase, directly phosphorylates and activates KCa3.1 and is required for the activation of human CD4 T lymphocytes. We now show that the class II phosphatidylinositol 3 kinase C2beta (PI3K-C2beta) is activated by the T-cell receptor (TCR) and functions upstream of NDPK-B to activate KCa3.1 channel activity. Decreased expression of PI3K-C2beta by siRNA in human CD4 T-cells resulted in inhibition of KCa3.1 channel activity. The inhibition was due to decreased phosphatidylinositol 3-phosphate [PI(3)P] because dialyzing PI3K-C2beta siRNA-treated T-cells with PI(3)P rescued KCa3.1 channel activity. Moreover, overexpression of PI3K-C2beta in KCa3.1-transfected Jurkat T-cells led to increased TCR-stimulated activation of KCa3.1 and Ca(2+) influx, whereas silencing of PI3K-C2beta inhibited both responses. Using total internal reflection fluorescence microscopy and planar lipid bilayers, we found that PI3K-C2beta colocalized with Zap70 and the TCR in peripheral microclusters in the immunological synapse. This is the first demonstration that a class II PI3K plays a critical role in T-cell activation.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Ativação Linfocitária , Fosfatidilinositol 3-Quinases/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Classe II de Fosfatidilinositol 3-Quinases , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Células Jurkat , Núcleosídeo-Difosfato Quinase/genética , Núcleosídeo-Difosfato Quinase/metabolismo , Técnicas de Patch-Clamp , Fosfatidilinositol 3-Quinases/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteína-Tirosina Quinase ZAP-70/genética , Proteína-Tirosina Quinase ZAP-70/metabolismo
12.
Proc Natl Acad Sci U S A ; 105(38): 14442-6, 2008 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-18796614

RESUMO

The calcium activated K(+) channel KCa3.1 plays an important role in T lymphocyte Ca(2+) signaling by helping to maintain a negative membrane potential, which provides an electrochemical gradient to drive Ca(2+) influx. We previously showed that nucleoside diphosphate kinase beta (NDPK-B), a mammalian histidine kinase, is required for KCa3.1 channel activation in human CD4 T lymphocytes. We now show that the mammalian protein histidine phosphatase (PHPT-1) directly binds and inhibits KCa3.1 by dephosphorylating histidine 358 on KCa3.1. Overexpression of wild-type, but not a phosphatase dead, PHPT-1 inhibited KCa3.1 channel activity. Decreased expression of PHPT-1 by siRNA in human CD4 T cells resulted in an increase in KCa3.1 channel activity and increased Ca(2+) influx and proliferation after T cell receptor (TCR) activation, indicating that endogenous PHPT-1 functions to negatively regulate CD4 T cells. Our findings provide a previously unrecognized example of a mammalian histidine phosphatase negatively regulating TCR signaling and are one of the few examples of histidine phosphorylation/dephosphorylation influencing a biological process in mammals.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Adulto , Animais , Linfócitos T CD4-Positivos/citologia , Células CHO , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Proliferação de Células , Cricetinae , Cricetulus , Expressão Gênica , Inativação Gênica , Histidina/metabolismo , Humanos , Imunoprecipitação , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/antagonistas & inibidores , Técnicas de Patch-Clamp , Monoéster Fosfórico Hidrolases/genética , RNA Interferente Pequeno/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...