RESUMEN
Chemotherapy remains a mainstay in the treatment of many types of cancer even though it is associated with debilitating behavioral side effects referred to as "chemobrain," including difficulty concentrating and memory impairment. The predominant hypothesis in the field is that systemic inflammation drives these cognitive impairments, although the brain mechanisms by which this occurs remain poorly understood. Here, we hypothesized that microglia are activated by chemotherapy and drive chemotherapy-associated cognitive impairments. To test this hypothesis, we treated female C57BL/6 mice with a clinically-relevant regimen of a common chemotherapeutic, paclitaxel (6 i.p. doses at 30 mg/kg), which impairs memory of an aversive stimulus as assessed via a contextual fear conditioning (CFC) paradigm. Paclitaxel increased the percent area of IBA1 staining in the dentate gyrus of the hippocampus. Moreover, using a machine learning random forest classifier we identified immunohistochemical features of reactive microglia in multiple hippocampal subregions that were distinct between vehicle- and paclitaxel-treated mice. Paclitaxel treatment also increased gene expression of inflammatory cytokines in a microglia-enriched population of cells from mice. Lastly, a selective inhibitor of colony stimulating factor 1 receptor, PLX5622, was employed to deplete microglia and then assess CFC performance following paclitaxel treatment. PLX5622 significantly reduced hippocampal gene expression of paclitaxel-induced proinflammatory cytokines and restored memory, suggesting that microglia play a critical role in the development of chemotherapy-associated neuroinflammation and cognitive impairments. This work provides critical evidence that microglia drive paclitaxel-associated cognitive impairments, a key mechanistic detail for determining preventative and intervention strategies for these burdensome side effects.
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Disfunción Cognitiva , Microglía , Ratones , Femenino , Animales , Microglía/metabolismo , Paclitaxel/efectos adversos , Ratones Endogámicos C57BL , Disfunción Cognitiva/inducido químicamente , Disfunción Cognitiva/metabolismo , Citocinas/metabolismo , Hipocampo/metabolismoRESUMEN
Over a third of patients with temporal lobe epilepsy (TLE) are not effectively treated with current anti-seizure drugs, spurring the development of gene therapies. The injection of adeno-associated viral vectors (AAV) into the brain has been shown to be a safe and viable approach. However, to date, AAV expression of therapeutic genes has not been regulated. Moreover, a common property of antiepileptic drugs is a narrow therapeutic window between seizure control and side effects. Therefore, a long-term goal is to develop drug-inducible gene therapies that can be regulated by clinically relevant drugs. In this study, a first-generation doxycycline-regulated gene therapy that delivered an engineered version of the leak potassium channel Kcnk2 (TREK-M) was injected into the hippocampus of male rats. Rats were electrically stimulated until kindled. EEG was monitored 24/7. Electrical kindling revealed an important side effect, as even low expression of TREK M in the absence of doxycycline was sufficient to cause rats to develop spontaneous recurring seizures. Treating the epileptic rats with doxycycline successfully reduced spontaneous seizures. Localization studies of infected neurons suggest seizures were caused by expression in GABAergic inhibitory neurons. In contrast, doxycycline increased the expression of TREK-M in excitatory neurons, thereby reducing seizures through net inhibition of firing. These studies demonstrate that drug-inducible gene therapies are effective in reducing spontaneous seizures and highlight the importance of testing for side effects with pro-epileptic stressors such as electrical kindling. These studies also show the importance of evaluating the location and spread of AAV-based gene therapies in preclinical studies.
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Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Epilepsia del Lóbulo Temporal , Epilepsia , Ratas , Masculino , Animales , Doxiciclina/farmacología , Neuronas/metabolismo , Epilepsia/metabolismo , Epilepsia del Lóbulo Temporal/metabolismo , Hipocampo/metabolismo , Terapia Genética , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/metabolismo , Modelos Animales de EnfermedadRESUMEN
Epileptogenesis is characterized by intrinsic changes in neuronal firing, resulting in hyperactive neurons and the subsequent generation of seizure activity. These alterations are accompanied by changes in gene transcription networks, first with the activation of early-immediate genes and later with the long-term activation of genes involved in memory. Our objective was to engineer a promoter containing binding sites for activity-dependent transcription factors upregulated in chronic epilepsy (EpiPro) and validate it in multiple rodent models of epilepsy. First, we assessed the activity dependence of EpiPro: initial electrophysiology studies found that EpiPro-driven GFP expression was associated with increased firing rates when compared with unlabeled neurons, and the assessment of EpiPro-driven GFP expression revealed that GFP expression was increased ~150× after status epilepticus. Following this, we compared EpiPro-driven GFP expression in two rodent models of epilepsy, rat lithium/pilocarpine and mouse electrical kindling. In rodents with chronic epilepsy, GFP expression was increased in most neurons, but particularly in dentate granule cells, providing in vivo evidence to support the "breakdown of the dentate gate" hypothesis of limbic epileptogenesis. Finally, we assessed the time course of EpiPro activation and found that it was rapidly induced after seizures, with inactivation following over weeks, confirming EpiPro's potential utility as a gene therapy driver for epilepsy.
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Epilepsia , Estado Epiléptico , Ratas , Ratones , Animales , Epilepsia/genética , Epilepsia/terapia , Epilepsia/metabolismo , Convulsiones/genética , Convulsiones/terapia , Convulsiones/metabolismo , Neuronas/metabolismo , Estado Epiléptico/genética , Estado Epiléptico/terapia , Estado Epiléptico/metabolismo , Pilocarpina , Terapia Genética , Modelos Animales de Enfermedad , Hipocampo/metabolismoRESUMEN
Cancer patients experience circadian rhythm disruptions in activity cycles and cortisol release that correlate with poor quality of life and decreased long-term survival rates. However, the extent to which chemotherapy contributes to altered circadian rhythms is poorly understood. In the present study, we examined the extent to which paclitaxel, a common chemotherapy drug, altered entrained and free-running circadian rhythms in wheel running behavior, circulating corticosterone, and circadian clock gene expression in the brain and adrenal glands of tumor-free mice. Paclitaxel injections delayed voluntary wheel running activity onset in a light-dark cycle (LD) and lengthened the free-running period of locomotion in constant darkness (DD), indicating an effect on inherent suprachiasmatic nucleus (SCN) pacemaker activity. Paclitaxel attenuated clock gene rhythms in multiple brain regions in LD and DD. Furthermore, paclitaxel disrupted circulating corticosterone rhythms in DD by elevating its levels across a 24-hour cycle, which correlated with blunted amplitudes of Arntl, Nr1d1, Per1, and Star rhythms in the adrenal glands. Paclitaxel also shortened SCN slice rhythms, increased the amplitude of adrenal gland oscillations in PER2::luciferase cultures, and increased the concentration of pro-inflammatory cytokines and chemokines released from the SCN. These findings indicate that paclitaxel disrupts clock genes and behavior driven by the SCN, other brain regions, and adrenal glands, which were associated with chemotherapy-induced inflammation. Together, this preclinical work demonstrates that chemotherapy disrupts both central and peripheral circadian rhythms and supports the possibility that targeted circadian realignment therapies may be a novel and non-invasive way to improve patient outcomes after chemotherapy.
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Relojes Circadianos , Animales , Ritmo Circadiano/genética , Humanos , Ratones , Actividad Motora/genética , Paclitaxel/farmacología , Proteínas Circadianas Period/genética , Calidad de VidaRESUMEN
Circadian rhythms influence various aspects of biology, including hormonal, immunological, and behavioral processes. These 24-hour oscillations are necessary to optimize cellular functions and to synchronize these processes with the environment. Breast cancer patients and survivors frequently report disruptions in circadian oscillations that adversely affect quality-of-life, including fragmented sleep-wake cycles and flattened cortisol rhythms, which are associated with negative behavioral comorbidities (e.g., fatigue). However, the potential causal role of tumor biology in circadian dysregulation has not been investigated. Here, we examined the extent to which sham surgery, non-metastatic mammary tumors, or mammary tumor removal in mice disrupts circadian rhythms in brain clock gene expression, locomotor behavior (free-running and entrained), and physiological rhythms that have been associated with cancer behavioral comorbidities. Tumors and tumor resection altered time-of-day differences in hypothalamic expression of eight circadian-regulated genes. The onset of activity in entrained running behavior was advanced in tumor-bearing mice, and the amplitude of free-running rhythms was increased in tumor-resected mice. Tumors flattened rhythms in circulating corticosterone and Ly6cHi monocytes which were largely restored by surgical tumor resection. This work implies that tumors alone may directly impact central and/or peripheral circadian rhythmicity in breast cancer patients, and that these effects may persist in cancer survivors, potentially contributing to behavioral comorbidities.
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Ritmo Circadiano/genética , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/metabolismo , Animales , Relojes Circadianos/genética , Ritmo Circadiano/fisiología , Corticosterona/metabolismo , Femenino , Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/genética , Hipotálamo/metabolismo , Neoplasias Mamarias Animales/genética , Neoplasias Mamarias Animales/metabolismo , Neoplasias Mamarias Experimentales/fisiopatología , Ratones , Ratones Endogámicos BALB C , Actividad Motora/fisiologíaRESUMEN
Circadian modulation of learning and memory efficiency is an evolutionarily conserved phenomenon, occurring in organisms ranging from invertebrates to higher mammalian species, including humans. While the suprachiasmatic nucleus (SCN) of the hypothalamus functions as the master mammalian pacemaker, recent evidence suggests that forebrain regions, including the hippocampus, exhibit oscillatory capacity. This finding, as well as work on the cellular signaling events that underlie learning and memory, has opened promising new avenues of investigation into the precise cellular, molecular, and circuit-based mechanisms by which clock timing impacts plasticity and cognition. In this review, we examine the complex molecular relationship between clock timing and memory, with a focus on hippocampal-dependent tasks. We evaluate how the dysregulation of circadian timing, both at the level of the SCN and at the level of ancillary forebrain clocks, affects learning and memory. Further, we discuss experimentally validated intracellular signaling pathways (e.g., ERK/MAPK and GSK3ß) and potential cellular signaling mechanisms by which the clock affects learning and memory formation. Finally, we examine how long-term potentiation (LTP), a synaptic process critical to the establishment of several forms of memory, is regulated by clock-gated processes.
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Ritmo Circadiano/fisiología , Hipocampo/fisiología , Aprendizaje/fisiología , Memoria/fisiología , Transducción de Señal/fisiología , Sinapsis/fisiología , Animales , Humanos , Potenciación a Largo Plazo/fisiología , Neuronas/fisiologíaRESUMEN
OBJECTIVE: To develop a constitutively active K(+) leak channel using TREK-1 (TWIK-related potassium channel 1; TREK-M) that is resistant to compensatory down-regulation by second messenger cascades, and to validate the ability of TREK-M to silence hyperactive neurons using cultured hippocampal neurons. To test if adenoassociated viral (AAV) delivery of TREK-M could reduce the duration of status epilepticus and reduce neuronal death induced by lithium-pilocarpine administration. METHODS: Molecular cloning techniques were used to engineer novel vectors to deliver TREK-M via plasmids, lentivirus, and AAV using a cytomegalovirus (CMV)-enhanced GABRA4 promoter. Electrophysiology was used to characterize the activity and regulation of TREK-M in human embryonic kidney (HEK-293) cells, and the ability to reduce spontaneous activity in cultured hippocampal neurons. Adult male rats were injected bilaterally with self-complementary AAV particles composed of serotype 5 capsid into the hippocampus and entorhinal cortex. Lithium-pilocarpine was used to induce status epilepticus. Seizures were monitored using continuous video-electroencephalography (EEG) monitoring. Neuronal death was measured using Fluoro-Jade C staining of paraformaldehyde-fixed brain slices. RESULTS: TREK-M inhibited neuronal firing by hyperpolarizing the resting membrane potential and decreasing input resistance. AAV delivery of TREK-M decreased the duration of status epilepticus by 50%. Concomitantly it reduced neuronal death in areas targeted by the AAV injection. SIGNIFICANCE: These findings demonstrate that TREK-M can silence hyperexcitable neurons in the brain of epileptic rats and treat acute seizures. This study paves the way for an alternative gene therapy treatment of status epilepticus, and provides the rationale for studies of AAV-TREK-M's effect on spontaneous seizures in chronic models of temporal lobe epilepsy.
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Técnicas de Transferencia de Gen , Neuronas/patología , Canales de Potasio de Dominio Poro en Tándem/genética , Estado Epiléptico/genética , Estado Epiléptico/prevención & control , Animales , Muerte Celular/genética , Polaridad Celular/genética , Vectores Genéticos/administración & dosificación , Vectores Genéticos/genética , Células HEK293 , Humanos , Masculino , Inhibición Neural/genética , Neuronas/fisiología , Canales de Potasio de Dominio Poro en Tándem/administración & dosificación , Ratas , Ratas Sprague-Dawley , Estado Epiléptico/patologíaRESUMEN
While the proliferation of data-driven omics technologies has continued to accelerate, methods of identifying relationships among large-scale changes from omics experiments have stagnated. It is therefore imperative to develop methods that can identify key mechanisms among one or more omics experiments in order to advance biological discovery. To solve this problem, here we describe the network-based algorithm MENTOR - Multiplex Embedding of Networks for Team-Based Omics Research. We demonstrate MENTOR's utility as a supervised learning approach to successfully partition a gene set containing multiple ontological functions into their respective functions. Subsequently, we used MENTOR as an unsupervised learning approach to identify important biological functions pertaining to the host genetic architectures in Populus trichocarpa associated with microbial abundance of multiple taxa. Moreover, as open source software designed with scientific teams in mind, we demonstrate the ability to use the output of MENTOR to facilitate distributed interpretation of omics experiments.
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Chronic pain is a common problem, with more than one-fifth of adult Americans reporting pain daily or on most days. It adversely affects the quality of life and imposes substantial personal and economic costs. Efforts to treat chronic pain using opioids had a central role in precipitating the opioid crisis. Despite an estimated heritability of 25-50%, the genetic architecture of chronic pain is not well-characterized, in part because studies have largely been limited to samples of European ancestry. To help address this knowledge gap, we conducted a cross-ancestry meta-analysis of pain intensity in 598,339 participants in the Million Veteran Program, which identified 126 independent genetic loci, 69 of which are new. Pain intensity was genetically correlated with other pain phenotypes, level of substance use and substance use disorders, other psychiatric traits, education level and cognitive traits. Integration of the genome-wide association studies findings with functional genomics data shows enrichment for putatively causal genes (n = 142) and proteins (n = 14) expressed in brain tissues, specifically in GABAergic neurons. Drug repurposing analysis identified anticonvulsants, ß-blockers and calcium-channel blockers, among other drug groups, as having potential analgesic effects. Our results provide insights into key molecular contributors to the experience of pain and highlight attractive drug targets.
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Dolor Crónico , Veteranos , Adulto , Humanos , Dolor Crónico/tratamiento farmacológico , Dolor Crónico/genética , Estudio de Asociación del Genoma Completo/métodos , Dimensión del Dolor , Calidad de Vida , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
The intracellular cholesterol transporter NPC1 functions in late endosomes and lysosomes to efflux unesterified cholesterol, and its deficiency causes Niemann-Pick disease Type C, an autosomal recessive lysosomal disorder characterized by progressive neurodegeneration and early death. Here, we use single-nucleus RNA-seq on the forebrain of Npc1-/- mice at P16 to identify cell types and pathways affected early in pathogenesis. Our analysis uncovers significant transcriptional changes in the oligodendrocyte lineage during developmental myelination, accompanied by diminished maturation of myelinating oligodendrocytes. We identify upregulation of genes associated with neurogenesis and synapse formation in Npc1-/- oligodendrocyte lineage cells, reflecting diminished gene silencing by H3K27me3. Npc1-/- oligodendrocyte progenitor cells reproduce impaired maturation in vitro, and this phenotype is rescued by treatment with GSK-J4, a small molecule inhibitor of H3K27 demethylases. Moreover, mobilizing stored cholesterol in Npc1-/- mice by a single administration of 2-hydroxypropyl-ß-cyclodextrin at P7 rescues myelination, epigenetic marks, and oligodendrocyte gene expression. Our findings highlight an important role for NPC1 in oligodendrocyte lineage maturation and epigenetic regulation, and identify potential targets for therapeutic intervention.
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Enfermedad de Niemann-Pick Tipo C , Animales , Ratones , Linaje de la Célula , Colesterol/metabolismo , Epigénesis Genética , Proteínas de Transporte de Membrana/metabolismo , Enfermedad de Niemann-Pick Tipo C/genética , Enfermedad de Niemann-Pick Tipo C/metabolismo , Oligodendroglía/metabolismoRESUMEN
Introduction: Despite a recent global decrease in suicide rates, death by suicide has increased in the United States. It is therefore imperative to identify the risk factors associated with suicide attempts to combat this growing epidemic. In this study, we aim to identify potential risk factors of suicide attempt using geospatial features in an Artificial intelligence framework. Methods: We use iterative Random Forest, an explainable artificial intelligence method, to predict suicide attempts using data from the Million Veteran Program. This cohort incorporated 405,540 patients with 391,409 controls and 14,131 attempts. Our predictive model incorporates multiple climatic features at ZIP-code-level geospatial resolution. We additionally consider demographic features from the American Community Survey as well as the number of firearms and alcohol vendors per 10,000 people to assess the contributions of proximal environment, access to means, and restraint decrease to suicide attempts. In total 1,784 features were included in the predictive model. Results: Our results show that geographic areas with higher concentrations of married males living with spouses are predictive of lower rates of suicide attempts, whereas geographic areas where males are more likely to live alone and to rent housing are predictive of higher rates of suicide attempts. We also identified climatic features that were associated with suicide attempt risk by age group. Additionally, we observed that firearms and alcohol vendors were associated with increased risk for suicide attempts irrespective of the age group examined, but that their effects were small in comparison to the top features. Discussion: Taken together, our findings highlight the importance of social determinants and environmental factors in understanding suicide risk among veterans.
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Chronic pain is a common problem, with more than one-fifth of adult Americans reporting pain daily or on most days. It adversely affects quality of life and imposes substantial personal and economic costs. Efforts to treat chronic pain using opioids played a central role in precipitating the opioid crisis. Despite an estimated heritability of 25-50%, the genetic architecture of chronic pain is not well characterized, in part because studies have largely been limited to samples of European ancestry. To help address this knowledge gap, we conducted a cross-ancestry meta-analysis of pain intensity in 598,339 participants in the Million Veteran Program, which identified 125 independent genetic loci, 82 of which are novel. Pain intensity was genetically correlated with other pain phenotypes, level of substance use and substance use disorders, other psychiatric traits, education level, and cognitive traits. Integration of the GWAS findings with functional genomics data shows enrichment for putatively causal genes (n = 142) and proteins (n = 14) expressed in brain tissues, specifically in GABAergic neurons. Drug repurposing analysis identified anticonvulsants, beta-blockers, and calcium-channel blockers, among other drug groups, as having potential analgesic effects. Our results provide insights into key molecular contributors to the experience of pain and highlight attractive drug targets.
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For plants, distinguishing between mutualistic and pathogenic microbes is a matter of survival. All microbes contain microbe-associated molecular patterns (MAMPs) that are perceived by plant pattern recognition receptors (PRRs). Lysin motif receptor-like kinases (LysM-RLKs) are PRRs attuned for binding and triggering a response to specific MAMPs, including chitin oligomers (COs) in fungi, lipo-chitooligosaccharides (LCOs), which are produced by mycorrhizal fungi and nitrogen-fixing rhizobial bacteria, and peptidoglycan in bacteria. The identification and characterization of LysM-RLKs in candidate bioenergy crops including Populus are limited compared to other model plant species, thus inhibiting our ability to both understand and engineer microbe-mediated gains in plant productivity. As such, we performed a sequence analysis of LysM-RLKs in the Populus genome and predicted their function based on phylogenetic analysis with known LysM-RLKs. Then, using predictive models, molecular dynamics simulations, and comparative structural analysis with previously characterized CO and LCO plant receptors, we identified probable ligand-binding sites in Populus LysM-RLKs. Using several machine learning models, we predicted remarkably consistent binding affinity rankings of Populus proteins to CO. In addition, we used a modified Random Walk with Restart network-topology based approach to identify a subset of Populus LysM-RLKs that are functionally related and propose a corresponding signal transduction cascade. Our findings provide the first look into the role of LysM-RLKs in Populus-microbe interactions and establish a crucial jumping-off point for future research efforts to understand specificity and redundancy in microbial perception mechanisms.
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Varicose veins represent a common cause of cardiovascular morbidity, with limited available medical therapies. Although varicose veins are heritable and epidemiologic studies have identified several candidate varicose vein risk factors, the molecular and genetic basis remains uncertain. Here we analyzed the contribution of common genetic variants to varicose veins using data from the Veterans Affairs Million Veteran Program and four other large biobanks. Among 49,765 individuals with varicose veins and 1,334,301 disease-free controls, we identified 139 risk loci. We identified genetic overlap between varicose veins, other vascular diseases and dozens of anthropometric factors. Using Mendelian randomization, we prioritized therapeutic targets via integration of proteomic and transcriptomic data. Finally, topological enrichment analyses confirmed the biologic roles of endothelial shear flow disruption, inflammation, vascular remodeling and angiogenesis. These findings may facilitate future efforts to develop nonsurgical therapies for varicose veins.
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The unprecedented scientific achievements in combating the COVID-19 pandemic reflect a global response informed by unprecedented access to data. We now have the ability to rapidly generate a diversity of information on an emerging pathogen and, by using high-performance computing and a systems biology approach, we can mine this wealth of information to understand the complexities of viral pathogenesis and contagion like never before. These efforts will aid in the development of vaccines, antiviral medications, and inform policymakers and clinicians. Here we detail computational protocols developed as SARS-CoV-2 began to spread across the globe. They include pathogen detection, comparative structural proteomics, evolutionary adaptation analysis via network and artificial intelligence methodologies, and multiomic integration. These protocols constitute a core framework on which to build a systems-level infrastructure that can be quickly brought to bear on future pathogens before they evolve into pandemic proportions.
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Tratamiento Farmacológico de COVID-19 , SARS-CoV-2 , Antivirales/farmacología , Antivirales/uso terapéutico , Inteligencia Artificial , Humanos , Pandemias/prevención & control , Biología de SistemasRESUMEN
While chemotherapy remains a common cancer treatment, it is associated with debilitating side effects (e.g., anorexia, weight loss, and fatigue) that adversely affect patient quality of life and increase mortality. However, the mechanisms underlying taxane chemotherapy-induced side effects, and effective treatments to ameliorate them, are not well-established. Here, we tested the longitudinal relationship between a clinically-relevant paclitaxel regimen, inflammation, and sickness behaviors (loss of body mass, anorexia, fever, and fatigue) in adult, female mice. Furthermore, we sought to identify the extent to which voluntary exercise (wheel running) attenuates paclitaxel-induced sickness behaviors and underlying central pathways. Body mass and food intake decreased following six doses of chemotherapy treatment relative to vehicle controls, lasting less than 5 days after the last dose. Paclitaxel treatment also transiently decreased locomotion (open field test), voluntary wheel running, home-cage locomotion, and core body temperature without affecting motor coordination (rotarod task). Circulating interleukin (IL)-6 and hypothalamic Il1b gene expression remained elevated in chemotherapy-treated mice at least 3 days after the last dose. Exercise intervention did not ameliorate fatigue or inflammation, but hastened recovery from paclitaxel-induced weight loss. Body mass recovery was associated with the wheel running-induced recovery of body composition, paclitaxel-induced alterations to hypothalamic melanocortin signaling, and associated peripheral circulating hormones (ghrelin and leptin). The present findings demonstrate the benefits of exercise on faster recovery from paclitaxel-induced body mass loss and deficits in melanocortin signaling and suggests the development of therapies targeting the melanocortin pathway to reduce paclitaxel-induced weight loss.
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Antineoplásicos/efectos adversos , Caquexia , Citocinas , Conducta de Enfermedad , Inflamación , Melanocortinas/metabolismo , Actividad Motora , Paclitaxel/efectos adversos , Condicionamiento Físico Animal/fisiología , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Caquexia/inducido químicamente , Caquexia/metabolismo , Caquexia/terapia , Citocinas/sangre , Citocinas/efectos de los fármacos , Fatiga/inducido químicamente , Fatiga/metabolismo , Fatiga/terapia , Femenino , Fiebre/inducido químicamente , Fiebre/metabolismo , Fiebre/terapia , Ghrelina/sangre , Ghrelina/efectos de los fármacos , Conducta de Enfermedad/efectos de los fármacos , Conducta de Enfermedad/fisiología , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/terapia , Leptina/sangre , Ratones Endogámicos C57BL , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiología , Transducción de Señal/fisiologíaRESUMEN
Improvements in breast cancer therapy/diagnosis have substantially increased the cancer survivor population, although many survivors report persistent mental health issues including fatigue, mood and anxiety disorders, and cognitive impairments. These behavioral symptoms impair quality-of-life and are often associated with increased inflammation. Nocturnal rodent models of cancer are critical to the identification of the neurobiological mechanisms underlying these behavioral changes. Although both behavior and immunity display distinct diurnal patterns, most rodent research in this field is performed during the rodents' inactive (light) period, which could potentially undermine the conclusions and clinical relevance. Therefore, here we tested the extent to which mammary tumors or tumor resection ("survivors") in mice affects behavior and neuroinflammation in a nyctohemeral (day versus night)-dependent manner. Indeed, only the dark (active) phase unmasked fatigue-like behavior and altered novel object investigation for both tumor-bearing and -resected mice relative to surgical controls. Several inflammatory markers were expressed in a time-of-day-dependent manner (lower in the dark phase) in the blood and brains of surgical control mice, whereas this temporal pattern was absent (IL-1ß, CXCL1, Myd88, Cd4) or reversed (C3) in the respective tissues of tumor-bearing and -resected mice. Taken together, these data indicate that the time of day of assessment significantly modulates various persistent and transient tumor-induced behavioral and immune changes.
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Ansiedad/fisiopatología , Encéfalo/fisiopatología , Depresión/fisiopatología , Fatiga/fisiopatología , Inflamación/fisiopatología , Neoplasias Mamarias Experimentales/fisiopatología , Animales , Ansiedad/psicología , Biomarcadores de Tumor/análisis , Línea Celular Tumoral , Depresión/psicología , Modelos Animales de Enfermedad , Fatiga/psicología , Femenino , Hábitos , Humanos , Inflamación/psicología , Neoplasias Mamarias Experimentales/psicología , Ratones Endogámicos BALB C , Factores de TiempoRESUMEN
Within the suprachiasmatic nucleus (SCN)-the locus of the master circadian clock- transcriptional regulation via the CREB/CRE pathway is implicated in the functioning of the molecular clock timing process, and is a key conduit through which photic input entrains the oscillator. One event driving CRE-mediated transcription is the phosphorylation of CREB at serine 133 (Ser133). Indeed, numerous reporter gene assays have shown that an alanine point mutation in Ser133 reduces CREB-mediated transcription. Here, we sought to examine the contribution of Ser133 phosphorylation to the functional role of CREB in SCN clock physiology in vivo. To this end, we used a CREB knock-in mouse strain, in which Ser133 was mutated to alanine (S/A CREB). Under a standard 12 h light-dark cycle, S/A CREB mice exhibited a marked alteration in clock-regulated wheel running activity. Relative to WT mice, S/A CREB mice had highly fragmented bouts of locomotor activity during the night phase, elevated daytime activity, and a delayed phase angle of entrainment. Further, under free-running conditions, S/A CREB mice had a significantly longer tau than WT mice and reduced activity amplitude. In S/A CREB mice, light-evoked clock entrainment, using both Aschoff type 1 and 6 h "jet lag" paradigms, was markedly reduced relative to WT mice. S/A CREB mice exhibited attenuated transcriptional drive, as assessed by examining both clock-gated and light-evoked gene expression. Finally, SCN slice culture imaging detected a marked disruption in cellular clock phase synchrony following a phase-resetting stimulus in S/A CREB mice. Together, these data indicate that signaling through CREB phosphorylation at Ser133 is critical for the functional fidelity of both SCN timing and entrainment.