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1.
J Immunol ; 200(9): 3077-3086, 2018 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-29602774

RESUMEN

Cytotoxic function and cytokine profile of NK cells are compromised in patients with systemic lupus erythematosus (SLE). CD3ζ, an important molecule for NK cell activation, is downregulated in SLE T cells and contributes to their altered function. However, little is known about the role of CD3ζ in SLE NK cells. We studied CD3ζ levels and its contribution to cytotoxic, degranulation, and cytokine production capacity of NK cells from patients with SLE. Furthermore, we studied the human NK cell line, NKL, in which manipulation of CD3ζ levels was achieved using small interfering RNA and NK cells from Rag2 mice deficient in CD3ζ. We found reduced CD3ζ expression in NK cells from SLE patients independent of disease activity. Downregulation of CD3ζ expression in NK cells is mediated, at least in part, by Caspase 3, the activity of which is higher in NK cells from patients with SLE compared with NK cells from healthy donors. CD3ζ levels correlated inversely with natural cytotoxicity and the percentage of cells capable of producing the proinflammatory cytokines IFN-γ and TNF. In contrast, CD3ζ levels showed a direct correlation with levels of Ab-dependent cellular cytotoxicity. Experiments performed in CD3ζ-silenced NKL and CD3ζ-deficient NK cells from Rag2 mice confirmed the dependence of NK cell function on CD3ζ levels. Our results demonstrate a differential role for CD3ζ in natural cytotoxicity and Ab-dependent cellular cytotoxicity. We conclude that downregulated CD3ζ confers a proinflammatory phenotype to SLE NK cells and contributes to their altered function in patients with SLE.


Asunto(s)
Complejo CD3/inmunología , Células Asesinas Naturales/inmunología , Lupus Eritematoso Sistémico/inmunología , Animales , Complejo CD3/metabolismo , Regulación hacia Abajo , Femenino , Humanos , Activación de Linfocitos/inmunología , Ratones , Fenotipo
2.
Proc Natl Acad Sci U S A ; 113(33): 9321-6, 2016 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-27482100

RESUMEN

Signaling lymphocytic activation molecule family 3 (SLAMF3/Ly9) is a coregulatory molecule implicated in T-cell activation and differentiation. Systemic lupus erythematosus (SLE) is characterized by aberrant T-cell activation and compromised IL-2 production, leading to abnormal regulatory T-cell (Treg) development/function. Here we show that SLAMF3 functions as a costimulator on CD4(+) T cells and influences IL-2 response and T helper cell differentiation. SLAMF3 ligation promotes T-cell responses to IL-2 via up-regulation of CD25 in a small mothers against decapentaplegic homolog 3 (Smad3)-dependent mechanism. This augments the activation of the IL-2/IL-2R/STAT5 pathway and enhances cell proliferation in response to exogenous IL-2. SLAMF3 costimulation promotes Treg differentiation from naïve CD4(+) T cells. Ligation of SLAMF3 receptors on SLE CD4(+) T cells restores IL-2 responses to levels comparable to those seen in healthy controls and promotes functional Treg generation. Taken together, our results suggest that SLAMF3 acts as potential therapeutic target in SLE patients by augmenting sensitivity to IL-2.


Asunto(s)
Linfocitos T CD4-Positivos/efectos de los fármacos , Interleucina-2/farmacología , Lupus Eritematoso Sistémico/inmunología , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/fisiología , Linfocitos T Reguladores/fisiología , Adulto , Anciano , Linfocitos T CD4-Positivos/inmunología , Diferenciación Celular , Polaridad Celular , Femenino , Humanos , Interleucina-2/biosíntesis , Subunidad alfa del Receptor de Interleucina-2/análisis , Subunidad alfa del Receptor de Interleucina-2/genética , Masculino , Persona de Mediana Edad
3.
Undersea Hyperb Med ; 46(2): 117-124, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31051056

RESUMEN

Objectives: Hyperbaric oxygen (HBO2) exposure may enhance cardiorespiratory fitness. Exercise training and HBO2 exposure stimulate mitochondrial biogenesis, increase capillary density, and induce adaptive antioxidant mechanisms. We hypothesized that an exercise regimen of sprint interval training (SIT) while breathing HBO2 would lead to a greater improvement in exercise performance compared to the same training breathing ambient air. Methods: Healthy long-term intermediate-altitude residents, ages 20-39 years, with normal spirometry and cardiorespiratory fitness were randomized to two groups: one performing six sessions of a SIT regimen over two weeks in a hyperbaric chamber (1.4 ATA [141.9 kPa], FiO2=1.0); the other performing under ambient pressure conditions (0.85 ATA [86.1 kPa], FiO2=0.21). Training effect was evaluated by comparing incremental cycle ergometry cardiopulmonary exercise testing before and after the training regimen. The primary outcome measure was peak oxygen consumption (V̇O2), while secondary outcomes included additional exercise parameters. The effect of study group on exercise parameters was assessed using two-factor repeated measures ANOVA. Results: Of 58 participants randomized, 49 completed the training program and all cardiopulmonary exercise tests (n=23 HBO2, n=26 ambient). Both groups experienced an increase in peak V̇O2: 8.1% HBO2 and 7.1% ambient; the differences were not significant (p=0.50). Secondary parameters of peak work rate and peak V̇E experienced a significantly higher change in the HBO2 group compared to the ambient group (p=0.05 and p=0.03, respectively). Conclusion: Cardiorespiratory fitness improved after a two-week SIT regimen, but improvement in peak V̇O2 was not significantly different between ambient and HBO2 groups.


Asunto(s)
Capacidad Cardiovascular , Entrenamiento de Intervalos de Alta Intensidad/métodos , Oxigenoterapia Hiperbárica/métodos , Consumo de Oxígeno , Adulto , Análisis de Varianza , Presión Atmosférica , Prueba de Esfuerzo/métodos , Femenino , Humanos , Masculino , Valores de Referencia , Factores Sexuales , Adulto Joven
4.
Brain Inj ; 32(5): 569-574, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29393686

RESUMEN

OBJECTIVE: This study aimed to identify the Balance Error Scoring System's (BESS) intraclass reliability in a cohort of patients with prolonged symptoms using variance component analysis and intraclass correlation coefficient (ICC). SETTING: Outpatient sports medicine/concussion clinic. PARTICIPANTS: A total of 241 paediatric and 102 adult patients with symptoms lasting longer than 10 days. INTERVENTIONS: BESS testing. DESIGN: Retrospective review. MAIN OUTCOME MEASURES: Percent variance for each BESS component and intraclass reliability. A five-component model (including all components except for firm double-leg) and a four- component model (including all components except for firm and foam doubleleg) were also performed to compare ICC values. RESULTS: The largest source of variance came from stance (41.1%). The BESS components firm single (25.5%) and foam tandem (27.5%) stances accounted for the largest percentages of variance, while firm double (1.1%) and foam double (6.9%) accounted for the smallest percentages. The ICC for all patients was 0.800, and increased both if the firm double stance was excluded, or if both double-leg stances were excluded. CONCLUSION: BESS reliability appears to be high in a concussed cohort, regardless of age. Removing the two double-leg stance portions increases the ICC of the test without failing to identify balance deficits.


Asunto(s)
Conmoción Encefálica/complicaciones , Examen Físico/métodos , Equilibrio Postural/fisiología , Trastornos de la Sensación/diagnóstico , Trastornos de la Sensación/etiología , Adolescente , Adulto , Factores de Edad , Niño , Estudios de Cohortes , Correlación de Datos , Femenino , Humanos , Masculino , Pacientes Ambulatorios , Reproducibilidad de los Resultados , Medicina Deportiva , Adulto Joven
6.
Brain Behav Immun ; 36: 61-70, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24145050

RESUMEN

Annual rhythms in morbidity and mortality are well-documented, and host defense mechanisms undergo marked seasonal phenotypic change. Siberian hamsters (Phodopus sungorus) exhibit striking immunological plasticity following adaptation to short winter day lengths (SD), including increases in blood leukocytes and in the magnitude of T cell-mediated immune responses. Thyroid hormone (TH) signaling is rate-limited by tissue-level expression of iodothyronine deiodinase types II and III (dio2, dio3), and dio2/dio3 expression in the central nervous system gate TH-dependent transduction of photoperiod information into the neuroendocrine system. THs are also potent immunomodulators, but their role in seasonal immunobiology remains unexamined. Here we report that photoperiod-driven changes in triiodothyronine (T3) signaling mediate seasonal changes in multiple aspects of immune function. Transfer from long days (LD) to SD inhibited leukocyte dio3 expression, which increased cellular T4→T3 catabolism. T3 was preferentially localized in the lymphocyte cytoplasm, consistent with a non-nuclear role of T3 in lymphoid cell differentiation and maturation. Exposure to SD upregulated leukocyte DNA methyltransferase expression and markedly increased DNA methylation in the dio3 proximal promoter region. Lastly, to bypass low endogenous T3 biosynthesis in LD lymphocytes, LD hamsters were treated with T3, which enhanced T cell-dependent delayed-type hypersensitivity inflammatory responses and blood leukocyte concentrations in a dose-dependent manner, mimicking effects of SD on these immunophenotypes. T3 signaling represents a novel mechanism by which environmental day length cues impact the immune system: changes in day length alter lymphoid cell T3-signaling via epigenetic transcriptional control of dio3 expression.


Asunto(s)
Ritmo Circadiano/inmunología , Yoduro Peroxidasa/metabolismo , Leucocitos/enzimología , Tiroxina/metabolismo , Triyodotironina/metabolismo , Animales , Cricetinae , Metilación de ADN , Femenino , Yoduro Peroxidasa/genética , Leucocitos/metabolismo , Masculino , Phodopus , Fotoperiodo , Estaciones del Año
7.
Horm Behav ; 66(1): 159-68, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24666779

RESUMEN

This article is part of a Special Issue "Energy Balance". Both the light-dark cycle and the timing of food intake can entrain circadian rhythms. Entrainment to food is mediated by a food entrainable circadian oscillator (FEO) that is formally and mechanistically separable from the hypothalamic light-entrainable oscillator. This experiment examined whether seasonal changes in day length affect the function of the FEO in male Siberian hamsters (Phodopus sungorus). Hamsters housed in long (LD; 15 h light/day) or short (SD; 9h light/day) photoperiods were subjected to a timed-feeding schedule for 10 days, during which food was available only during a 5h interval of the light phase. Running wheel activity occurring within a 3h window immediately prior to actual or anticipated food delivery was operationally-defined as food anticipatory activity (FAA). After the timed-feeding interval, hamsters were fed ad libitum, and FAA was assessed 2 and 7 days later via probe trials of total food deprivation. During timed-feeding, all hamsters exhibited increases FAA, but FAA emerged more rapidly in SD; in probe trials, FAA was greater in magnitude and persistence in SD. Gonadectomy in LD did not induce the SD-like FAA phenotype, indicating that withdrawal of gonadal hormones is not sufficient to mediate the effects of photoperiod on FAA. Entrainment of the circadian system to light markedly affects the functional output of the FEO via gonadal hormone-independent mechanisms. Rapid emergence and persistent expression of FAA in SD may reflect a seasonal adaptation that directs behavior toward sources of nutrition with high temporal precision at times of year when food is scarce.


Asunto(s)
Adaptación Fisiológica/fisiología , Ritmo Circadiano/fisiología , Cricetinae/fisiología , Conducta Alimentaria/fisiología , Hormonas Gonadales/fisiología , Actividad Motora/fisiología , Fotoperiodo , Animales , Castración , Ingestión de Alimentos/fisiología , Privación de Alimentos/fisiología , Hormonas Gonadales/metabolismo , Masculino , Phodopus/fisiología
8.
Curr Res Neurobiol ; 7: 100136, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39239479

RESUMEN

Iron is an important cofactor for many proteins and is used to create Fe-S clusters and heme prosthetic groups that enzymes use to catalyze enzymatic reactions. Proteins involved in the import, export, and sequestration of iron are regulated by Iron Regulatory Proteins (IRPs). Recently, a patient with bi-allelic loss of function mutations in IREB2 leading to the absence of IRP2 protein was discovered. The patient failed to achieve developmental milestones and was diagnosed with dystonic cerebral palsy, epilepsy, microcytic hypochromic anemia, and frontal lobe atrophy. Several more IREB2 deficient patients subsequently identified manifested similar neurological problems. To better understand the manifestations of this novel neurological disease, we subjected an Irp2-null mouse model to extensive behavioral testing. Irp2-null mice had a significant motor deficit demonstrated by reduced performance on rotarod and hanging wire tests. Somatosensory function was also compromised in hot and cold plate assays. Their spatial search strategy was impaired in the Barnes maze and they exhibited a difficulty in flexibly adapting their response in the operant touchscreen reversal learning task. The latter is a cognitive behavior known to require an intact prefrontal cortex. These results suggest that loss of Irp2 in mice causes motor and behavioral deficits that faithfully reflect the IREB2 patient's neurodegenerative disorder.

9.
bioRxiv ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38766181

RESUMEN

The recent upsurge in the use of common marmosets (Callithrix jacchus) as a desirable model for high priority biomedical research has challenged local and global suppliers struggling to provide sufficient numbers of marmosets for large scale projects. Scientific research laboratories are increasingly establishing institutional breeding colonies, in part to combat the resulting shortage and high cost of commercially available animals, and in part to have maximum control over research lines involving reproduction and development. For such laboratories, efficient marmoset breeding can be challenging and time consuming. Random male/female pairings are often unsuccessful, with intervals of several months before attempting alternate pairings. Here we address this challenge through a behavioral task that promotes self-directed female selection of potential mates to increase the efficiency of breeding in captive marmosets. We created a partner preference test ('love maze') in which nulliparous females (n=12) had the opportunity to select between two eligible males (n=23) at a time, in a forced choice test. In this test, both males usually displayed sexual solicitations. However, the female would clearly indicate her preference for one. Most commonly, the female actively ignored the non-preferred male and directed overt prosocial behaviors (e.g. proceptive tongue-flicking, approach and grooming) to the preferred male. Moreover, once a male was selected in this context, the female would continue to prefer him over other males in three consecutive testing sessions. Compared with random pairings, this directed female choice showed a 2.5-fold improvement in breeding within 90 days compared to random pairings. This cost-effective and straightforward pairing practice can be used to enhance breeding efficiency in both small and large marmoset colonies.

10.
bioRxiv ; 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38529485

RESUMEN

The social dynamics of vocal behavior has major implications for social development in humans. We asked whether early life damage to the anterior cingulate cortex (ACC), which is closely associated with socioemotional regulation more broadly, impacts the normal development of vocal expression. The common marmoset provides a unique opportunity to study the developmental trajectory of vocal behavior, and to track the consequences of early brain damage on aspects of social vocalizations. We created ACC lesions in neonatal marmosets and compared their pattern of vocalization to that of age-matched controls throughout the first 6 weeks of life. We found that while early life ACC lesions had little influence on the production of vocal calls, developmental changes to the quality of social contact calls and their associated syntactical and acoustic characteristics were compromised. These animals made fewer social contact calls, and when they did, they were short, loud and monotonic. We further determined that damage to ACC in infancy results in a permanent alteration in downstream brain areas known to be involved in social vocalizations, such as the amygdala and periaqueductal gray. Namely, in the adult, these structures exhibited diminished GABA-immunoreactivity relative to control animals, likely reflecting disruption of the normal inhibitory balance following ACC deafferentation. Together, these data indicate that the normal development of social vocal behavior depends on the ACC and its interaction with other areas in the vocal network during early life.

11.
bioRxiv ; 2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-39131306

RESUMEN

While amino acid neurotransmitters are the main chemical messengers in the brain, they are co-expressed with neuropeptides which are increasingly recognized as modulators of cognitive pathways. For example, the neuropeptide galanin has been implicated in a wide range of pathological conditions in which frontal and temporal structures are compromised. In a recent study in rats, we discovered that direct pharmacological stimulation of galanin receptor type 1 (GalR1) in the ventral prefrontal cortex (vPFC) and ventral hippocampus (vHC) led to opposing effects on attention and impulse control behavior. In the present study, we investigate how subtypes of neurons expressing GalR1 in these two areas differentially contribute to these behaviors. We first establish that GalR1 is predominantly expressed in glutamatergic neurons in both the vPFC and HC. We develop a novel viral approach to gain genetic access to GalR1-expressing neurons and demonstrate that optogenetic excitation of GalR1 expressing neurons in the vPFC, but not vHC, selectively disrupts attention in a complex behavioral task. Finally, using fiber photometry, we measure the bulk calcium dynamics in GalR1-expressing neurons during the same task to demonstrate opposing activity in vPFC and vHC. These results are consistent with our previous work demonstrating differential behavioral effects induced by GalR1 activating in vPFC and vHC. These results indicate the distinct neuromodulatory and behavioral contributions of galanin mediated by subclasses of neurons in the hippocampal and prefrontal circuitry.

12.
Brain Behav Immun ; 32: 94-104, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23474187

RESUMEN

The immune system is under strong circadian control, and circadian desynchrony is a risk factor for metabolic disorders, inflammatory responses and cancer. Signaling pathways that maintain circadian rhythms (CRs) in immune function in vivo, and the mechanisms by which circadian desynchrony impairs immune function, remain to be fully identified. These experiments tested the hypothesis that the hypothalamic circadian pacemaker in the suprachiasmatic nucleus (SCN) drives CRs in the immune system, using a non-invasive model of SCN circadian arrhythmia. Robust CRs in blood leukocyte trafficking, with a peak during the early light phase (ZT4) and nadir in the early dark phase (ZT18), were absent in arrhythmic hamsters, as were CRs in spleen clock gene (per1, bmal1) expression, indicating that a functional pacemaker in the SCN is required for the generation of CRs in leukocyte trafficking and for driving peripheral clocks in secondary lymphoid organs. Pinealectomy was without effect on CRs in leukocyte trafficking, but abolished CRs in spleen clock gene expression, indicating that nocturnal melatonin secretion is necessary for communicating circadian time information to the spleen. CRs in trafficking of antigen presenting cells (CD11c(+) dendritic cells) in the skin were abolished, and antigen-specific delayed-type hypersensitivity skin inflammatory responses were markedly impaired in arrhythmic hamsters. The SCN drives robust CRs in leukocyte trafficking and lymphoid clock gene expression; the latter of which is not expressed in the absence of melatonin. Robust entrainment of the circadian pacemaker provides a signal critical to diurnal rhythms in immunosurveilliance and optimal memory T-cell dependent immune responses.


Asunto(s)
Relojes Circadianos/inmunología , Dermatitis/inmunología , Leucocitos/inmunología , Ciclos de Actividad/inmunología , Animales , Relojes Circadianos/genética , Ritmo Circadiano/genética , Cricetinae , ADN Complementario/biosíntesis , ADN Complementario/genética , Oscuridad , Células Dendríticas/efectos de los fármacos , Células Dendríticas/fisiología , Femenino , Citometría de Flujo , Expresión Génica , Hidrocortisona/sangre , Hipersensibilidad Tardía/inmunología , Iluminación , Tejido Linfoide/inmunología , Tejido Linfoide/fisiología , Masculino , Melatonina/farmacología , Actividad Motora/fisiología , Proteínas Circadianas Period , Phodopus , Glándula Pineal/fisiología , Reacción en Cadena de la Polimerasa , ARN/biosíntesis , ARN/aislamiento & purificación , Bazo/fisiología , Estrés Psicológico/inmunología , Estrés Psicológico/psicología
13.
Elife ; 122023 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-36951911

RESUMEN

Recently developed methods for video analysis, especially models for pose estimation and behavior classification, are transforming behavioral quantification to be more precise, scalable, and reproducible in fields such as neuroscience and ethology. These tools overcome long-standing limitations of manual scoring of video frames and traditional 'center of mass' tracking algorithms to enable video analysis at scale. The expansion of open-source tools for video acquisition and analysis has led to new experimental approaches to understand behavior. Here, we review currently available open-source tools for video analysis and discuss how to set up these methods for labs new to video recording. We also discuss best practices for developing and using video analysis methods, including community-wide standards and critical needs for the open sharing of datasets and code, more widespread comparisons of video analysis methods, and better documentation for these methods especially for new users. We encourage broader adoption and continued development of these tools, which have tremendous potential for accelerating scientific progress in understanding the brain and behavior.


Asunto(s)
Algoritmos , Programas Informáticos , Animales , Conducta Animal , Etología , Grabación en Video
14.
Neurooncol Adv ; 5(1): vdad108, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37781088

RESUMEN

Background: Hypersomnolence is a common and disruptive side effect of cranial radiotherapy and is associated with fatigue and disturbances in mood and cognition in primary brain tumor (PBT) patients. The biological underpinnings of this effect are not understood. Our laboratory has previously found that the presence of a single nucleotide polymorphism (rs934945, G-E mutation) in the PERIOD2 (PER2) clock gene was associated with a decreased likelihood of fatigue in PBT patients. Here, we aim to understand the effects of PER2 polymorphism on radiation susceptibility within a murine model of cranial-irradiation-induced hypersomnolence (C-RIH). Methods: Male and female transgenic mice were generated using CRISPR-Cas9, replacing the endogenous mouse PER2:CRY1 binding domain with its human isoform with (hE1244 KI) or without the SNP rs934945 (hG1244 KI). Activity and sleep were monitored continuously 10 days before and after cranial irradiation (whole brain, 15Gy, single fraction). Behavioral assessments measuring anxiety, depression, and working memory were used to assess mood and cognitive changes 2 months postradiation. Results: During their active phase, hE1244 knock-ins (KIs) had less radiation-induced suppression of activity relative to hG1244 KIs and female hE1244 KIs saw a reduction of hypersomnolence over 10 days. hE1244 KIs displayed less anxiety behavior and were more ambulatory within all behavioral tests. Conclusions: The PER2 rs934945 polymorphism had long-lasting behavioral effects associated with radiation toxicity, particularly in sleep in females and the activity of all animals. Our findings shed light on biological mechanisms underlying C-RIH.

15.
J Am Acad Dermatol ; 67(1): e29-35, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21907449

RESUMEN

BACKGROUND: We report 7 patients with a distinct and unusual eruption consisting of a neutrophilic dermatosis in conjunction with lupus erythematosus (LE). The significance of these findings and their relevance to LE are discussed. OBJECTIVE: We aimed to evaluate the significance of eruptive neutrophilic dermatosis in conjunction with LE. METHODS: Seven original cases were collected during 10 years at a tertiary referral center, and were reviewed by a single board-certified dermatopathologist. All patient demographics were tabulated and analyzed. Eleven articles reporting 15 similar cases were obtained from a literature review. RESULTS: Of a total of 7 adult patients, 14% (1 of 7) had a history of LE, whereas 86% (6 of 7) exhibited synchronous initial presentation of neutrophilic dermatosis with LE. Of note, 100% (7 of 7) of the patients exhibited cutaneous lesions on sun-exposed sites. LIMITATIONS: Only 7 of 400,000 cases showed this phenomenon, giving rise to the idea this may be just by chance. CONCLUSIONS: Our data and literature review suggest the existence of a neutrophilic dermatosis distinct from conventional Sweet syndrome that may herald conventional signs and symptoms or represent an initial presentation of cutaneous LE. This neutrophilic dermatosis may share a similar pathogenic mechanism related to ultraviolet exposure.


Asunto(s)
Lupus Eritematoso Sistémico/diagnóstico , Neutrófilos/patología , Piel/patología , Síndrome de Sweet/diagnóstico , Adulto , Anciano , Diagnóstico Diferencial , Femenino , Humanos , Lupus Eritematoso Cutáneo/diagnóstico , Lupus Eritematoso Cutáneo/patología , Lupus Eritematoso Sistémico/patología , Masculino , Persona de Mediana Edad , Síndrome de Sweet/patología
16.
Horm Behav ; 58(4): 647-52, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20600050

RESUMEN

Animals living in temperate climates with predictable seasonal changes in food availability may use seasonal information to engage different metabolic strategies. Siberian hamsters decrease costs of thermoregulation during winter by reducing food intake and body mass in response to decreasing or short-day lengths (SD). These experiments examined whether SD reduction in food intake in hamsters is driven, at least in part, by altered behavioral responses to ghrelin, a gut-derived orexigenic peptide which induces food intake via NPY-dependent mechanisms. Relative to hamsters housed in long-day (LD) photoperiods, SD hamsters consumed less food in response to i.p. treatment with ghrelin across a range of doses from 0.03 to 3 mg/kg. To determine whether changes in photoperiod alter behavioral responses to ghrelin-induced activation of NPY neurons, c-Fos and NPY expression were quantified in the arcuate nucleus (ARC) via double-label fluorescent immunocytochemistry following i.p. treatment with 0.3 mg/kg ghrelin or saline. Ghrelin induced c-Fos immunoreactivity (-ir) in a greater proportion of NPY-ir neurons of LD relative to SD hamsters. In addition, following ghrelin treatment, a greater proportion of ARC c-Fos-ir neurons were identifiable as NPY-ir in LD relative to SD hamsters. Changes in day length markedly alter the behavioral response to ghrelin. The data also identify photoperiod-induced changes in the ability of ghrelin to activate ARC NPY neurons as a possible mechanism by which changes in day length alter food intake.


Asunto(s)
Ingestión de Alimentos/efectos de los fármacos , Ghrelina/farmacología , Phodopus/fisiología , Fotoperiodo , Animales , Núcleo Arqueado del Hipotálamo/efectos de los fármacos , Núcleo Arqueado del Hipotálamo/metabolismo , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Peso Corporal/efectos de los fármacos , Ritmo Circadiano , Cricetinae , Ingestión de Alimentos/fisiología , Conducta Alimentaria/efectos de los fármacos , Conducta Alimentaria/fisiología , Péptidos y Proteínas de Señalización Intracelular/farmacología , Neuropéptido Y/metabolismo , Neuropéptidos/farmacología , Orexinas , Phodopus/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Estaciones del Año
17.
Cell Rep ; 30(1): 112-123.e4, 2020 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-31914379

RESUMEN

Patients with systemic lupus erythematosus (SLE) suffer frequent infections that account for significant morbidity and mortality. T cell cytotoxic responses are decreased in patients with SLE, yet the responsible molecular events are largely unknown. We find an expanded CD8CD38high T cell subset in a subgroup of patients with increased rates of infections. CD8CD38high T cells from healthy subjects and patients with SLE display decreased cytotoxic capacity, degranulation, and expression of granzymes A and B and perforin. The key cytotoxicity-related transcription factors T-bet, RUNX3, and EOMES are decreased in CD8CD38high T cells. CD38 leads to increased acetylated EZH2 through inhibition of the deacetylase Sirtuin1. Acetylated EZH2 represses RUNX3 expression, whereas inhibition of EZH2 restores CD8 T cell cytotoxic responses. We propose that high levels of CD38 lead to decreased CD8 T cell-mediated cytotoxicity and increased propensity to infections in patients with SLE, a process that can be reversed pharmacologically.


Asunto(s)
ADP-Ribosil Ciclasa 1/metabolismo , Linfocitos T CD8-positivos/inmunología , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Infecciones/inmunología , Lupus Eritematoso Sistémico/inmunología , NAD/metabolismo , Sirtuina 1/metabolismo , Linfocitos T Citotóxicos/inmunología , Adulto , Línea Celular , Femenino , Humanos , Lupus Eritematoso Sistémico/microbiología , Masculino , Factores de Transcripción/metabolismo
18.
Med Sci Sports Exerc ; 50(3): 589-595, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29189667

RESUMEN

INTRODUCTION/PURPOSE: Cardiopulmonary exercise testing (CPET) plays an important role in clinical medicine and research. Repeatability of CPET parameters has not been well characterized, but is important to assess variability and determine if there have been meaningful changes in a given CPET parameter. METHODS: We recruited 45 healthy subjects and performed two symptom-limited CPET within 30 d using a cycle ergometer. Differences in relevant CPET parameters between CPET-1 and CPET-2 were assessed using a paired t-test. Coefficient of variation (CoV) and Bland-Altman plots are reported. Factors that may be associated with variability were analyzed (sex, age, time of day, fitness level). The coefficient of repeatability was calculated for peak oxygen consumption (V˙O2) and V˙O2 at lactate threshold (LT) to establish a 95% threshold for meaningful change. RESULTS: There were no significant differences between tests in the parameters reported. Specifically, we found overall low CoV in peak V˙O2 (4.9%), V˙O2@LT (10.4%), peak O2 pulse (4.6%), peak minute ventilation (V˙E; 7.4%), V˙E/V˙CO2@LT (4.0%), and V˙E/V˙O2@LT (4.8%). The CoV for peak respiratory exchange ratio@LT was significantly affected by diurnal factors; age, sex, and fitness level did not affect variability. The 95% threshold for meaningful change was 0.540 L·min in peak V˙O2 and 0.520 L·min in V˙O2@LT. CONCLUSIONS: Repeatability of CPET parameters is generally higher than previously reported. There were no significant differences in variability related to sex, age, and fitness level; diurnal factors had a limited effect. The threshold for meaningful change in peak V˙O2 and for V˙O2@LT should be considered when gauging a response to therapies or training.


Asunto(s)
Prueba de Esfuerzo/normas , Consumo de Oxígeno , Reproducibilidad de los Resultados , Adulto , Femenino , Voluntarios Sanos , Humanos , Ácido Láctico/sangre , Masculino
19.
Prim Dent Care ; 14(3): 117-22, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17650390

RESUMEN

OBJECTIVE: To seek opinions from general dental practitioners in Calderdale and Kirklees (West Yorkshire) regarding an online orthodontic referral service and to establish the profile of dentists working in primary care who would refer patients online for a consultant orthodontist's opinion. METHODOLOGY: All 91 general dental practices in Calderdale and Kirklees in West Yorkshire were sent a piloted questionnaire enquiring into their orthodontic treatment and referral patterns, and also into their attitudes to the use of the Internet and related technologies. Three mailings were performed, followed by telephone contact with non-responders. RESULTS: Usable responses were obtained from 119 general dental practitioners who worked in 71 practices (78%). Analysis of data showed that, when asked whether they would be interested in using teledentistry to obtain a consultant orthodontist's opinion online, 53/116 (46%) replied positively. The most frequently specified reason for this interest was that it would save time and would achieve a quicker opinion for a practitioner's treatment plan. These dentists were more likely to be familiar with the use of digital cameras, be using removable appliances, and currently be in the habit of referring orthodontic cases to consultants and specialists. CONCLUSIONS: Just under half of the dentists working in primary care in Calderdale and Kirklees who responded had a positive attitude towards the benefits of a teledentistry referral scheme. However, a substantial number remained undecided, possibly because they were unsure of their information technology (IT) skills. A further pilot study is planned. It will enquire into the feasibility of carrying out such an exercise across West Yorkshire.


Asunto(s)
Odontología General , Ortodoncia , Consulta Remota , Actitud del Personal de Salud , Inglaterra , Femenino , Humanos , Internet , Modelos Logísticos , Masculino , Proyectos Piloto , Encuestas y Cuestionarios
20.
Nat Rev Nephrol ; 13(6): 329-343, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28287110

RESUMEN

Glomerulonephritis is traditionally considered to result from the invasion of the kidney by autoantibodies and immune complexes from the circulation or following their formation in situ, and by cells of the innate and the adaptive immune system. The inflammatory response leads to the proliferation and dysfunction of cells of the glomerulus, and invasion of the interstitial space with immune cells, resulting in tubular cell malfunction and fibrosis. T cells are critical drivers of autoimmunity and related organ damage, by supporting B-cell differentiation and antibody production or by directly promoting inflammation and cytotoxicity against kidney resident cells. T cells might become activated by autoantigens in the periphery and become polarized to secrete inflammatory cytokines before entering the kidney where they have the opportunity to expand owing to the presence of costimulatory molecules and activating cytokines. Alternatively, naive T cells could enter the kidney where they become activated after encountering autoantigen and expand locally. As not all individuals with a peripheral autoimmune response to kidney antigens develop glomerulonephritis, the contribution of local kidney factors expressed or produced by kidney cells is probably of crucial importance. Improved understanding of the biochemistry and molecular biology of T cells in patients with glomerulonephritis offers unique opportunities for the recognition of treatment targets for autoimmune kidney disease.


Asunto(s)
Autoinmunidad , Enfermedades Renales/inmunología , Linfocitos T/fisiología , Animales , Autoanticuerpos/inmunología , Citocinas/fisiología , Glomerulonefritis/inmunología , Humanos , Inmunidad Innata , Inflamación/inmunología , Lupus Eritematoso Sistémico/inmunología
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