RESUMO
Adverse childhood experiences (ACEs) are early-life psychosocial stressors that are associated with poorer mental health and increased cardiovascular disease (CVD) risk in a dose-dependent manner. We examined the feasibility of an 8-wk combined aerobic and resistance exercise training program to improve systolic (SBP) and diastolic blood pressure (DBP), serum endothelin-1 (ET-1), resilience, hope agency, and hope pathways in young women with ACEs. Forty-two healthy women (21 ± 3 yr) with ≥4 (ACE+; n = 28) or 0 ACEs (ACE-; n = 14) participated in this study. Women with ACEs were randomly assigned to an exercise (ACE+EXT; n = 14) or nonexercise control (ACE+CON; n = 14) group, whereas all ACE- participants were assigned to a nonexercise control (n = 14) group. Hope agency and DBP did not change in any group (P ≥ 0.43), but hope pathways improved only in ACE+EXT (means ± SE change; +1.6 ± 0.74 au, P = 0.032, Hedges' g = 0.53). ET-1 decreased in ACE+EXT only (-0.31 ± 0.15 pg/mL, P = 0.043, g = 0.46). Although the interactions for resilience and SBP did not reach significance (P = 0.05-0.06), forced post hoc analyses indicated that resilience improved (+4.9 ± 1.9 au, P = 0.012, g = 0.64) and SBP tended to improve (-4.0 ± 2.0 mmHg, P = 0.053, g = 0.51) in ACE+EXT only. There were significant associations between changes in hope pathways and SBP (ρ = -0.43, P = 0.023) and ET-1 (ρ = -0.53, P = 0.005), and between changes in SBP and ET-1 (ρ = 0.49; P = 0.012) in the ACE+ group. In summary, structured exercise training reduces serum ET-1 levels, improves positive psychological coping, and may improve SBP in young women with ACEs. The relationships among the changes in hope pathways, SBP, and ET-1 suggest a cardiovascular psychophysiological relationship in young women with ACEs.NEW & NOTEWORTHY This randomized controlled pilot trial shows, for the first time, that 8 wk of structured, progressive exercise training lowers serum endothelin-1 (ET-1) and improves positive psychological coping in young women with significant early-life psychosocial stress. Furthermore, the observed associations among changes in psychological attributes, ET-1, and systolic blood pressure signify a potential interplay between positive psychology and cardiovascular disease risk among women with adverse childhood experiences.
Assuntos
Experiências Adversas da Infância , Doenças Cardiovasculares , Feminino , Humanos , Adulto Jovem , Pressão Sanguínea/fisiologia , Endotelina-1 , Exercício Físico , AdolescenteRESUMO
Adverse childhood experiences (ACEs) are psychosocial stressors that occur during sensitive developmental windows and are associated with increased lifetime cardiovascular disease (CVD) risk in a dose-dependent manner. Vascular endothelial dysfunction is a pathophysiological mechanism that promotes hypertension and CVD and may be a mechanism by which ACEs contribute to lifetime CVD risk. We examined whether exposure to ACEs is associated with reduced vascular endothelial function (VEF) in otherwise healthy, young adult women (20.7 ± 3 yr) with (ACE+) versus without (ACE-) ACEs, explored whether differences in circulating sirtuin 1 (SIRT1) or systemic oxidative stress could explain ACEs-related differences in VEF, and examined the ability of a pilot, 8-wk exercise intervention to augment VEF and SIRT1 or reduce oxidized LDL cholesterol (oxLDL) in ACE+ young adult women. Forty-two otherwise healthy young adults completed this study. Prior to the intervention, VEF (P = 0.002) and SIRT1 (P = 0.004) were lower in the ACE+ than ACE- group, but oxLDL concentrations were not different (P = 0.77). There were also significant relationships (P ≤ 0.04) among flow-mediated dilation (FMD), SIRT1, and oxLDL in the ACE+, but not ACE- group. Adjusting for circulating SIRT1 and oxLDL reduced the differences in FMD observed between groups (P = 0.10), but only SIRT1 was a significant adjuster of the means (P < 0.05). Finally, the exercise intervention employed was unable to enhance VEF or SIRT1 in the ACE+ exercise group. Our data suggest that ACEs likely increase susceptibility to hypertension and CVD by causing endothelial dysfunction, perhaps through a SIRT1 pathway-related mechanism.NEW & NOTEWORTHY Our study provides novel evidence that young adult women with moderate-to-severe adverse childhood experience (ACE) exposure present impaired endothelial function and lower circulating sirtuin 1 (SIRT1) concentrations than age-matched controls. However, an 8-wk exercise intervention was unable to augment endothelial function or SIRT1 concentrations in a subset of those with ACEs. Our data suggest that ACEs-related impairments in endothelial function may be secondary to decreased NO bioavailability via SIRT1 and/or oxidative stress-related mechanisms.
Assuntos
Experiências Adversas da Infância , Endotélio Vascular/metabolismo , Estresse Oxidativo , Sirtuína 1/genética , Estresse Psicológico/metabolismo , Adolescente , Adulto , Idoso , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sirtuína 1/metabolismo , Estresse Psicológico/etiologia , Estresse Psicológico/fisiopatologiaRESUMO
BACKGROUND: Major depressive disorder (MDD) is the leading cause of years lived with disability; however, little is known about its etiology to inform treatment. For a subset of MDD patients, appetite change and/or bodily inflammation may play a role in exacerbating symptoms. The goal of this study is to examine whether, relative to healthy comparisons (HC), MDD individuals with increased versus decreased appetite symptoms show a differential relationship between diet quality and inflammation. METHODS: Unmedicated current MDD (n = 61) varying in appetite change (decrease (MDD-DE): n = 39; increase (MDD-IN): n = 22) and HC (n = 42) completed 24-hour dietary recall and state depression/anxiety measures. Healthy eating and dietary inflammatory indices were calculated from dietary reports. Blood samples measured five inflammation-related biomarkers. Analyses investigated between- and within-group differences in the Healthy Eating Index (HEI), the Dietary Inflammatory Index (DII), inflammation-related blood biomarkers, and symptom severity. RESULTS: While both MDD-DE and MDD-IN exhibited lower HEI scores than HC, only MDD-IN showed higher plasma interleukin-1 receptor antagonist (IL-1RA) and interleukin-6 (IL-6) levels than HC. In contrast, MDD-DE exhibited higher DII scores than MDD-IN and HC. Within MDD-DE, greater symptom severity was associated with lower HEI and higher DII. LIMITATIONS: Modest sample sizes and the cross-sectional study design limited power to detect within-MDD effects. CONCLUSIONS: Although MDD, regardless of appetite change, is linked to poorer dietary quality, depression severity was related to dietary characteristics only in subjects who reported appetite loss. Thus, increasing the quality of dietary intake could be a treatment target for some individuals with depression.
Assuntos
Apetite , Transtorno Depressivo Maior , Dieta , Inflamação , Estudos Transversais , Transtorno Depressivo Maior/fisiopatologia , HumanosRESUMO
There exists little human neuroscience research to explain why some individuals lose their appetite when they become depressed, while others eat more. Answering this question may reveal much about the various pathophysiologies underlying depression. The present study combined neuroimaging, salivary cortisol, and blood markers of inflammation and metabolism collected prior to scanning. We compared the relationships between peripheral endocrine, metabolic, and immune signaling and brain activity to food cues between depressed participants experiencing increased (N = 23) or decreased (N = 31) appetite and weight in their current depressive episode and healthy control participants (N = 42). The two depression subgroups were unmedicated and did not differ in depression severity, anxiety, anhedonia, or body mass index. Depressed participants experiencing decreased appetite had higher cortisol levels than subjects in the other two groups, and their cortisol values correlated inversely with the ventral striatal response to food cues. In contrast, depressed participants experiencing increased appetite exhibited marked immunometabolic dysregulation, with higher insulin, insulin resistance, leptin, CRP, IL-1RA, and IL-6, and lower ghrelin than subjects in other groups, and the magnitude of their insulin resistance correlated positively with the insula response to food cues. These findings provide novel evidence linking aberrations in homeostatic signaling pathways within depression subtypes to the activity of neural systems that respond to food cues and select when, what, and how much to eat. In conjunction with prior work, the present findings strongly support the existence of pathophysiologically distinct depression subtypes for which the direction of appetite change may be an easily measured behavioral marker.
Assuntos
Apetite , Depressão/imunologia , Depressão/metabolismo , Adolescente , Adulto , Apetite/imunologia , Proteína C-Reativa/análise , Depressão/sangue , Depressão/classificação , Feminino , Grelina/sangue , Humanos , Hidrocortisona/análise , Inflamação/sangue , Inflamação/complicações , Inflamação/imunologia , Insulina/sangue , Insulina/metabolismo , Resistência à Insulina , Proteína Antagonista do Receptor de Interleucina 1/sangue , Proteína Antagonista do Receptor de Interleucina 1/imunologia , Interleucina-6/sangue , Interleucina-6/imunologia , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Saliva/química , Adulto JovemRESUMO
In chronic kidney disease (CKD), elevated serum levels of the phosphate regulating hormone fibroblast growth factor (FGF) 23 have emerged as powerful risk factors for cardiovascular disease and death. Mechanistically, FGF23 can bind and activate fibroblast growth factor receptor (FGFR) 4 independently of α-klotho, the canonical co-receptor for FGF23 in the kidney, which stimulates left ventricular hypertrophy and hepatic production of inflammatory cytokines. FGF23 has also been shown to independently predict progression of renal disease, however, whether FGF23 and FGFR4 also contribute to CKD remains unknown. Here, we generated a mouse model with dual deletions of FGFR4 and α-klotho, and we induced CKD in mice with either global deletion or constitutive activation of FGFR4. We demonstrate that FGF23 is not capable of inducing phosphaturia via FGFR4 and that FGFR4 does not promote or mitigate renal injury in animal models of CKD. Taken together our results suggest FGFR4 inhibition as a safe alternative strategy to target cardiovascular disease and chronic inflammation in patients with CKD without interrupting the necessary phosphaturic effects of FGF23.
Assuntos
Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/metabolismo , Insuficiência Renal Crônica/patologia , Animais , Modelos Animais de Doenças , Progressão da Doença , Fator de Crescimento de Fibroblastos 23 , Técnicas de Introdução de Genes , Glucuronidase/metabolismo , Humanos , Proteínas Klotho , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/fisiologia , Fatores de RiscoRESUMO
OBJECTIVE: To explore the potential of mHealth using smartphones to improve fruit and vegetable intake in children. DESIGN: A 10-week randomized control and intervention pilot study. SETTING: Story time sessions at local libraries. PARTICIPANTS: A convenience sample of 30 parents and children (aged 3-8 years). INTERVENTION: Delivery of nutrition intervention through the mobile Jump2Health website, Facebook posts, and text messages. MAIN OUTCOME MEASURES: Electronic food photos of children's meals and snacks, 10-question survey related to fruit and vegetable consumption, reflectance spectroscopy via Veggie Meter to measure skin carotenoid levels, body mass index percentiles, and a mobile learning survey. ANALYSIS: Descriptive statistics and Wilcoxon matched-pairs signed-rank test. RESULTS: Veggie Meter values for children and parents showed significant weekâ¯×â¯treatment interactions in the intervention group compared with the control group for both children (P < .001 and parents (P < .001). CONCLUSIONS AND IMPLICATIONS: This pilot study offers a potentially effective program including a mobile Web site, social media, and test message components to increase fruit and vegetable intake of young children.
Assuntos
Carotenoides/análise , Preferências Alimentares , Frutas , Promoção da Saúde/métodos , Verduras , Adulto , Criança , Pré-Escolar , Comportamento Alimentar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pais , Projetos Piloto , Pele/química , Smartphone , Mídias Sociais , Telemedicina/métodos , Texas , Adulto JovemRESUMO
Background: In US, approximately 23% of children between the ages of 2-5 years are overweight or obese. Parents need access to information to create healthy home environments for obesity prevention, yet participation for in-person education programs is challenging. Web-based interventions are promising educational tools due to 24/7 availability. However, information is limited on their development and evaluation. Design and Methods: This study reports on a rigorous development process that included six focus group discussions (FGD) with stakeholders (three FGD each with parents and teachers) to assess education needs and inform the development of the Jump2Health Website™ by a multidisciplinary team. After development, the Website was evaluated by telephone interviews with stakeholders (five parents and six teachers) and reviewed by an expert panel of five Registered Dietitians. Results: Twenty Head Start parents and 22 Head Start teachers participated in the FGD. To address the needs identified by these stakeholders, the Website was designed to include components that were enabling and motivating, such as descriptions of health benefits by achieving the desired behaviours, short videos on easy meal preparation, and tip sheets on how to achieve healthy behaviours in easy, economical ways. Stakeholder evaluation of the Website indicated that the information was helpful, easy to use, and would be beneficial for parents. Conclusions: The development of Jump2Health Website™ was strengthened by FGD with stakeholders that assessed educational needs. Interviews with stakeholders and an expert panel review showed that the Website may be an effective educational method to teach parents about healthy behaviours related to obesity prevention.
RESUMO
Few interventions have been shown to be successful in reducing child obesity, due in part to the challenges in reaching parents. Web-based nutrition intervention is becoming more feasible due to technology advancements and accessibility across income groups. However, studies on the effectiveness and acceptability of web-based interventions to teach parents about healthy behaviors are needed. The purpose of this study was to evaluate the Jump2Health™ Website intervention using qualitative interview methodology. A follow-up phone interview was conducted with 13 participants, approximately 1-to 2-month-postintervention. Participants reported making desired behavior changes in targeted areas and also considered the Website an effective learning method.
RESUMO
Although IL-18 has not previously been shown to promote T lymphopoiesis, results obtained via a novel data mining algorithm (global microarray meta-analysis) led us to explore a predicted role for this cytokine in T cell development. IL-18 is a member of the IL-1 cytokine family that has been extensively characterized as a mediator of inflammatory immune responses. To assess a potential role for IL-18 in T cell development, we sort-purified mouse bone marrow-derived common lymphoid progenitor cells, early thymic progenitors (ETPs), and double-negative 2 thymocytes and cultured these populations on OP9-Delta-like 4 stromal layers in the presence or absence of IL-18 and/or IL-7. After 1 wk of culture, IL-18 promoted proliferation and accelerated differentiation of ETPs to the double-negative 3 stage, similar in efficiency to IL-7. IL-18 showed synergy with IL-7 and enhanced proliferation of both the thymus-derived progenitor cells and the bone marrow-derived common lymphoid progenitor cells. The synergistic effect on the ETP population was further characterized and found to correlate with increased surface expression of c-Kit and IL-7 receptors on the IL-18-treated cells. In summary, we successfully validated the global microarray meta-analysis prediction that IL-18 affects T lymphopoiesis and demonstrated that IL-18 can positively impact bone marrow lymphopoiesis and T cell development, presumably via interaction with the c-Kit and IL-7 signaling axis.
Assuntos
Proliferação de Células/fisiologia , Interleucina-18/imunologia , Interleucina-7 , Linfopoese , Células Precursoras de Linfócitos T/imunologia , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/imunologia , Interleucina-18/agonistas , Interleucina-18/genética , Interleucina-7/agonistas , Interleucina-7/genética , Interleucina-7/imunologia , Linfopoese/genética , Linfopoese/imunologia , Camundongos , Camundongos Mutantes , Análise de Sequência com Séries de Oligonucleotídeos , Células Precursoras de Linfócitos T/citologia , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologiaRESUMO
BACKGROUND: We have developed a 12-parameter/10-color flow cytometric staining method for the simultaneous detection and characterization of 21 mouse thymocyte subpopulations that represent discreet stages of T cell development. To demonstrate the utility of this method, we assessed cytokine receptor expression on mouse thymocyte subsets. These experiments revealed distinct patterns of surface expression of receptors for the cytokines IL-4 and IL-6. RESULTS: The IL-4 receptor α chain (CD124) was highly expressed on the earliest thymocyte subsets, then downregulated prior to T cell receptor ß-selection and finally upregulated in the CD4/CD8 double positive cells prior to positive selection. The IL-6 receptor α chain (CD126) showed a different pattern of expression. It was expressed on the most mature subsets within the CD4 and CD8 single positive (SP) compartments and was absent on all other thymocytes with the exception of a very small cKit-CD4-CD8- population. Intracellular staining of SP thymocytes for phosphorylated STAT-1 demonstrated that IL-6 signaling was confined to the most mature SP subsets. CONCLUSIONS: This 12-parameter staining methodology uses only commercially available fluorochrome-coupled monoclonal antibodies and therefore could be employed by any investigator with access to a 4-laser flow cytometer. This novel staining scheme allowed us to easily phenotype thymocyte subpopulations that span across development, from the early thymic progenitors (ETPs) to the most mature subsets of the CD4 and CD8 single positive populations.
Assuntos
Subunidade alfa de Receptor de Interleucina-4/metabolismo , Subunidade alfa de Receptor de Interleucina-6/metabolismo , Subpopulações de Linfócitos T/metabolismo , Linfócitos T/metabolismo , Timo/citologia , Animais , Diferenciação Celular/imunologia , Linhagem da Célula/imunologia , Separação Celular , Células Cultivadas , Citometria de Fluxo/instrumentação , Citometria de Fluxo/métodos , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Timo/embriologia , Timo/crescimento & desenvolvimentoRESUMO
CD27 and CD28 have emerged as indicators demarcating the transition of thymocytes through beta-selection. We found that CD28 exhibits a greater dynamic range of expression during this phase, thus it was employed to further parse the DN/CD44(-) compartment in order to assess IL-7 signaling during the beta-selection process. Plotting CD28 versus CD25 expression revealed six DN/CD44(-) populations. OP9-DL1 stromal cell co-culture was used to demonstrate a developmental linkage from DN3a (CD25(+)CD28(-/lo)) to DN3b (CD25(+)CD28(+)) to DN3c (CD25(int)CD28(+)) to DN4a (CD25(-)CD28(+)) to double positive (DP) and showed the DN4b (CD25(-)CD28(hi)) and DN4c (CD25(-)CD28(-/lo)) populations to be inefficient in producing DP cells. Using CD69 as an additional marker to further parse the DN4a population, we found the pre-DP cells to be the CD44(-)CD25(-)CD28(int)CD69(-)CD4(-/lo)CD8(-/lo) subset. Using this refined developmental scheme, IL-7R alpha expression was found to be transiently up-regulated post-beta-selection in the DN3b and DN3c subsets; however, this increase did not confer enhanced responsiveness over that observed in the DN3a population. CD28 messenger RNA expression was up-regulated in post-beta-selected cells, whereas transcripts for CD27, IL-7R alpha and Bcl-2 were lower than that observed in the DN3a population. This study refines the current thymocyte differentiation scheme to allow for more detailed evaluation of events controlling early T-cell development, specifically surrounding the beta-selection checkpoint.
Assuntos
Antígenos CD28/genética , Antígenos CD28/imunologia , Diferenciação Celular , Linfócitos T/citologia , Timo/citologia , Animais , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Diferenciação Celular/imunologia , Técnicas de Cocultura , Citometria de Fluxo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Subunidade alfa de Receptor de Interleucina-2/genética , Subunidade alfa de Receptor de Interleucina-2/imunologia , Lectinas Tipo C/genética , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , Receptores de Interleucina-7/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/imunologia , Timo/imunologiaRESUMO
Interleukin (IL)-7 is a factor essential for mouse and human thymopoiesis. Mouse thymocytes have altered sensitivities to IL-7 at different developmental stages. CD4/CD8 double positive (DP) mouse thymocytes are shielded from the influence of IL-7 because of loss of CD127 (IL-7Ralpha). In this study, we assessed IL-7 receptor expression and IL-7 signaling in human thymocytes. We found human DP cells to be severely limited in their ability to phosphorylate STAT-5 in response to IL-7. The relative expression levels of the IL-7-inducible proteins Bcl-2 and Mcl-1 were also lower in human DP cells, consistent with a stage-specific decrease in IL-7 responsiveness. IL-7 responses were restored in a subset of cells that matured past the DP stage. Unlike the regulation of IL-7 signaling in mouse thymocytes, loss of IL-7 signaling in human DP cells was not due to absence of CD127, but instead correlated with downregulation of CD132 (common gamma chain).
Assuntos
Subunidade gama Comum de Receptores de Interleucina/metabolismo , Interleucina-7/farmacologia , Células Precursoras de Linfócitos T/efeitos dos fármacos , Receptores de Interleucina-7/metabolismo , Animais , Antígenos CD4/biossíntese , Antígenos CD8/biossíntese , Diferenciação Celular , Células Cultivadas , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Subunidade gama Comum de Receptores de Interleucina/genética , Subunidade gama Comum de Receptores de Interleucina/imunologia , Interleucina-7/imunologia , Camundongos , Células Precursoras de Linfócitos T/citologia , Células Precursoras de Linfócitos T/imunologia , Células Precursoras de Linfócitos T/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Interleucina-7/genética , Receptores de Interleucina-7/imunologia , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Timo/citologia , Timo/imunologiaRESUMO
Thymocyte development is accompanied by sequential changes in cell surface glycosylation. For example, medullary thymocytes have increased levels of alpha2,3-linked sialic acid and a loss of asialo core 1 O-glycans as compared to cortical thymocytes. Some of these changes have been linked to fine tuning of the T cell receptor avidity. We analyzed ST6Gal I transcript abundance and levels of alpha2,6-linked sialic acid across thymocyte subsets. We found that ST6Gal I transcript levels increased following T cell receptor beta-selection suggesting that this sialyltransferase may influence the development of early thymocyte populations. Indeed, low levels of alpha2,6-linked sialic acid were found in the earliest T lineage cells, and then increased in T cell receptor beta-selected cells. To determine whether ST6Gal I influences T cell development, we analyzed ST6Gal I-deficient mice for disruptions in thymocyte populations. We found reduced thymic cellularity in the ST6Gal I-deficient mice starting in the early thymocyte compartments.
Assuntos
Diferenciação Celular/genética , Sialiltransferases/genética , Timo/citologia , Animais , Contagem de Células , Feminino , Perfilação da Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Oligossacarídeos/metabolismo , Timo/crescimento & desenvolvimento , Timo/metabolismo , beta-D-Galactosídeo alfa 2-6-SialiltransferaseRESUMO
Murine thymocytes down-regulate IL-7 responsiveness following beta-selection and reacquire sensitivity after positive selection. To assess the potential consequences of IL-7 signaling during this phase of development, transgenic IL-7 receptor alpha (IL-7Ralpha) mice were evaluated for IL-7 responsiveness as gauged by STAT-5 phosphorylation. Transgenic IL-7Ralpha expression increased the percentage of thymocytes responsive to IL-7 yet resulted in a decrease in total thymic cellularity. Aberrant thymocyte development in transgenic mice was first manifested by a reduction of DN3 thymocytes that correlated with lower Bcl-2 expression. Surprisingly, transgenic restoration of Bcl-2 expression did not correct thymic hypocellularity induced by IL-7Ralpha overexpression. These findings demonstrate that failure to appropriately downregulate IL-7Ralpha expression interferes with thymocyte development past the pro-T stage resulting in significantly lower levels of mature thymocytes.
Assuntos
Subunidade alfa de Receptor de Interleucina-7/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Timo/citologia , Animais , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Células Cultivadas , DNA Complementar/genética , Citometria de Fluxo , Técnicas de Transferência de Genes , Subunidade alfa de Receptor de Interleucina-7/genética , Linfopoese/imunologia , Camundongos , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Timo/embriologia , Timo/imunologiaRESUMO
This study utilized suppressive subtractive hybridization between the clinical isolate Burkholderia cenocepacia J2315 and the closely related environmental isolate Burkholderia cepacia ATCC 25416(T) to isolate DNA fragments specific to B. cenocepacia J2315. Analysis of the resulting pools of B. cenocepacia-specific DNAs identified several fragments that may be part of putative virulence factors. Further in silico analysis of a single fragment indicated that it was internal to a gene of which the predicted product had characteristics of repeat in toxin (RTX)-like proteins and high similarity to proteins in other human or plant pathogens. In conjunction with this finding, phenotypic traits associated with known RTX proteins were assessed. A haemagglutinating activity of B. cenocepacia J2315 was identified that was absent in B. cepacia ATCC 25416(T). The expression of this activity appeared to be growth phase-dependent. Analysis of the gene presence and haemagglutinating activity across the species of the B. cepacia complex showed that both were common to the ET12 lineage of B. cenocepacia, but were absent in the other species examined. Haemagglutinating activity was limited to isolates with the RTX-like gene. Expression studies utilizing quantitative PCR demonstrated an association between onset of haemagglutinating activity and increased expression of the gene, which suggests that the putative RTX determinant encodes a haemagglutinating activity.