RESUMEN
Background: Hippocampal and cerebellar neuropathology occurs in individuals with alcohol use disorders (AUD), resulting in impaired cognitive and motor function.Objectives: Evaluate the effects of ethanol on the expression of pro- and anti-inflammatory molecules, as well as the effects of the anti-inflammatory PPAR-γ agonist pioglitazone in suppressing ethanol-induced neuroinflammation.Methods: Adult male and female mice were treated chronically with ethanol for just under a month followed by a single acute binge dose of ethanol. Animals were provided liquid diet in the absence of ethanol (Control; n = 18, 9 M/9F), liquid diet containing ethanol (ethanol; n = 22, 11 M/11F), or liquid diet containing ethanol plus gavage administration of 30.0 mg/kg pioglitazone (ethanol + pioglitazone; n = 20, 10 M/10F). The hippocampus and cerebellum were isolated 24 h following the binge dose of ethanol, mRNA was isolated, and pro- and anti-inflammatory molecules were quantified by qRT-PCR.Results: Ethanol significantly (p < .05) increased the expression of pro-inflammatory molecules IL-1ß, TNF-α, CCL2, and COX2; increased the expression of inflammasome-related molecules NLRP3 and Casp1 but decreased IL-18; and altered the expression of anti-inflammatory molecules including TGFßR1 in the hippocampus and cerebellum, though some differences were observed between males and females and the two brain regions. The anti-inflammatory pioglitazone inhibited ethanol-induced alterations in the expression of most, but not all, inflammation-related molecules.Conclusion: Chronic plus binge administration of ethanol induced the expression of inflammatory molecules in adult mice and pioglitazone suppressed ethanol-induced neuroinflammation.
Asunto(s)
Alcoholismo , Etanol , Ratones , Femenino , Masculino , Animales , Etanol/farmacología , Pioglitazona/metabolismo , Pioglitazona/farmacología , Enfermedades Neuroinflamatorias , Hipocampo , Cerebelo/metabolismoRESUMEN
Ethanol exposure to the fetus during pregnancy can result in fetal alcohol spectrum disorders (FASD). These disorders vary in severity, can affect multiple organ systems, and can lead to lifelong disabilities. Damage to the central nervous system (CNS) is common in FASD, and can result in altered behavior and cognition. The incidence of FASD is alarmingly high, resulting in significant personal and societal costs. There are no cures for FASD. Alcohol can directly alter the function of neurons in the developing CNS. In addition, ethanol can alter the function of CNS glial cells including microglia and astrocytes which normally maintain homeostasis in the CNS. These glial cells can function as resident immune cells in the CNS to protect against pathogens and other insults. However, activation of glia can also damage CNS cells and lead to aberrant CNS function. Ethanol exposure to the developing brain can result in the activation of glia and neuroinflammation, which may contribute to the pathology associated with FASD. This suggests that anti-inflammatory agents may be effective in the treatment of FASD.
Asunto(s)
Astrocitos/metabolismo , Sistema Nervioso Central/metabolismo , Etanol/farmacología , Trastornos del Espectro Alcohólico Fetal/metabolismo , Microglía/metabolismo , Enfermedades Neuroinflamatorias/metabolismo , Animales , Antiinflamatorios/farmacología , Astrocitos/inmunología , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/fisiopatología , Femenino , Trastornos del Espectro Alcohólico Fetal/inmunología , Trastornos del Espectro Alcohólico Fetal/fisiopatología , Humanos , Microglía/inmunología , Enfermedades Neuroinflamatorias/inmunología , Enfermedades Neuroinflamatorias/fisiopatología , EmbarazoRESUMEN
Fetal alcohol spectrum disorders (FASD) are the most common cause of nonheritable, preventable mental disability and are characterized by cognitive, behavioral, and physical impairments. FASD occurs in almost 5% of births in the United States, but despite this prevalence there is no known cure, largely because the biological mechanisms that translate alcohol exposure to neuropathology are not well understood. While the effects of early ethanol exposure on neuronal survival and circuitry have received more attention, glia, the cells most closely tied to initiating and propagating inflammatory events, could be an important target for alcohol in the developing brain. Inflammation is known to alter developmental trajectories, but it has recently been shown that even small changes in both astrocytes and microglia in the absence of full-blown inflammatory signaling can alter brain function long-term. Here, we studied the acute response of astrocytes and microglia to a single exposure to ethanol in development across sexes in a mouse model of human third trimester exposure, in order to understand how these cells may transition from their normal developmental path to a different program that leads to FASD neuropathology. We found that although a single ethanol exposure delivered subcutaneously on postnatal day 4 did not cause large changes in microglial morphology or the expression of AldH1L1 and GFAP in the cortex and hippocampus, subtle effects were observed. These findings suggest that even a single, early ethanol exposure can induce mild acute alterations in glia that could contribute to developmental deficits.
Asunto(s)
Astrocitos/metabolismo , Astrocitos/patología , Etanol/farmacología , Microglía/metabolismo , Microglía/patología , Animales , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Trastornos del Espectro Alcohólico Fetal/metabolismo , Trastornos del Espectro Alcohólico Fetal/patología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/patología , Ratones , Ratones Endogámicos C57BLRESUMEN
Fetal alcohol spectrum disorders (FASD) are alarmingly common, result in significant personal and societal loss, and there is no effective treatment for these disorders. Cerebellar neuropathology is common in FASD and causes aberrant cognitive and motor function. Ethanol-induced neuroinflammation is believed to contribute to neuropathological sequelae of FASD, and was previously demonstrated in the cerebellum in animal models of FASD. We now demonstrate neuroinflammation persists in the cerebellum several days following cessation of ethanol treatment in an early postnatal mouse model, with meaningful implications for timing of therapeutic intervention in FASD. We also demonstrate by Sholl analysis that ethanol decreases ramification of microglia cell processes in cells located near the Purkinje cell layer but not those near the external granule cell layer. Ethanol did not alter the expression of anti-inflammatory molecules or molecules that constitute NLRP1 and NLRP3 inflammasomes. Interestingly, ethanol decreased the expression of IL-23a (P19) and IL-12Rß1 suggesting that ethanol may suppress IL-12 and IL-23 signaling. Fractalkine-fractalkine receptor (CX3CL1-CX3CR1) signaling is believed to suppress microglial activation and our demonstration that ethanol decreases CX3CL1 expression suggests that ethanol modulation of CX3CL1-CX3CR1 signaling may contribute to cerebellar neuroinflammation and neuropathology. We demonstrate ethanol alters the expression of specific molecules in the cerebellum understudied in FASD, but crucial for immune responses. Ethanol increases the expression of NOX-2 and NGP and decreases the expression of RAG1, NOS1, CD59a, S1PR5, PTPN22, GPR37, and Serpinb1b. These molecules represent a new horizon as potential targets for development of FASD therapy.
Asunto(s)
Cerebelo/metabolismo , Trastornos del Espectro Alcohólico Fetal/metabolismo , Microglía/metabolismo , Enfermedades Neuroinflamatorias/metabolismo , Animales , Cerebelo/patología , Quimiocina CX3CL1/metabolismo , Citocinas/metabolismo , Femenino , Expresión Génica , Inflamasomas/metabolismo , Ratones , Ratones Endogámicos C57BL , Microglía/patología , EmbarazoRESUMEN
BACKGROUND: The developing hippocampus and cerebellum, unique among brain regions, exhibit a secondary surge in neurogenesis during the third trimester of pregnancy. Ethanol (EtOH) exposure during this period is results in a loss of tissue volume and associated neurobehavioral deficits. However, mechanisms that link EtOH exposure to teratology in these regions are not well understood. We therefore analyzed transcriptomic adaptations to EtOH exposure to identify mechanistic linkages. METHODS: Hippocampi and cerebella were microdissected at postnatal day (P)10, from control C57BL/6J mouse pups, and pups treated with 4 g/kg of EtOH from P4 to P9. RNA was isolated and RNA-seq analysis was performed. We compared gene expression in EtOH- and vehicle-treated control neonates and performed biological pathway-overrepresentation analysis. RESULTS: While EtOH exposure resulted in the general induction of genes associated with the S-phase of mitosis in both cerebellum and hippocampus, overall there was little overlap in differentially regulated genes and associated biological pathways between these regions. In cerebellum, EtOH additionally induced gene expression associated with the G2/M-phases of the cell cycle and sonic hedgehog signaling, while in hippocampus, EtOH-induced the pathways for ribosome biogenesis and protein translation. Moreover, EtOH inhibited the transcriptomic identities associated with inhibitory interneuron subpopulations in the hippocampus, while in the cerebellum there was a more pronounced inhibition of transcripts across multiple oligodendrocyte maturation stages. CONCLUSIONS: These data indicate that during the delayed neurogenic period, EtOH may stimulate the cell cycle, but it otherwise results in widely divergent molecular effects in the hippocampus and cerebellum. Moreover, these data provide evidence for region- and cell-type-specific vulnerability, which may contribute to the pathogenic effects of developmental EtOH exposure.
Asunto(s)
Animales Recién Nacidos/crecimiento & desarrollo , Cerebelo/crecimiento & desarrollo , Etanol/efectos adversos , Hipocampo/crecimiento & desarrollo , Neurogénesis/efectos de los fármacos , Transcriptoma/efectos de los fármacos , Animales , Apoptosis/genética , Ciclo Celular/genética , Cerebelo/metabolismo , Etanol/administración & dosificación , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Hipocampo/metabolismo , Interneuronas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Embarazo , ARN Mensajero/análisisAsunto(s)
Etanol , Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Enfermedades no Transmisibles , Proteína con Dominio Pirina 3 de la Familia NLR/antagonistas & inhibidores , Humanos , Inflamasomas/efectos de los fármacos , Enfermedades no Transmisibles/tratamiento farmacológico , AnimalesRESUMEN
In both multiple sclerosis and experimental autoimmune encephalomyelitis (EAE), the C-C chemokine receptor 6 (CCR6) is critical for pathogenic T helper 17 (Th17) cell migration to the central nervous system (CNS). Whereas many cytokines and their receptors are potently regulated via post-transcriptional mechanisms in response to various stimuli, how CCR6 expression is post-transcriptionally regulated in Th17 cells is unknown. Here, using RNA-binding protein HuR conditional knock-out (KO) and wild-type (WT) mice, we present evidence that HuR post-transcriptionally regulates CCR6 expression by binding to and stabilizing Ccr6 mRNA and by promoting CCR6 translation. We also found that HuR down-regulates several microRNA expressions, which could target the 3'-UTR of Ccr6 mRNA for decay. Accordingly, knock-out of HuR reduced CCR6 expression on Th17 cells and impaired their migration to CNS compared with the response of WT Th17 cells and thereby ameliorated EAE. Together, these findings highlight how HuR contributes to Th17 cell-mediated autoimmune neuroinflammation and support the notion that targeting HuR might be a potential therapeutic intervention for managing autoimmune disorders of the CNS.
Asunto(s)
Proteína 1 Similar a ELAV/metabolismo , Regulación de la Expresión Génica , ARN Mensajero/metabolismo , Receptores CCR6/agonistas , Linfocitos T Colaboradores-Inductores/metabolismo , Regiones no Traducidas 3' , Animales , Enfermedades Autoinmunes del Sistema Nervioso/inmunología , Enfermedades Autoinmunes del Sistema Nervioso/metabolismo , Enfermedades Autoinmunes del Sistema Nervioso/patología , Línea Celular , Movimiento Celular , Células Cultivadas , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/metabolismo , Sistema Nervioso Central/patología , Proteína 1 Similar a ELAV/antagonistas & inhibidores , Proteína 1 Similar a ELAV/genética , Encefalomielitis/inmunología , Encefalomielitis/metabolismo , Encefalomielitis/patología , Humanos , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , MicroARNs/metabolismo , Biosíntesis de Proteínas , Interferencia de ARN , Estabilidad del ARN , Receptores CCR6/antagonistas & inhibidores , Receptores CCR6/genética , Receptores CCR6/metabolismo , Linfocitos T Colaboradores-Inductores/citología , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/patologíaRESUMEN
Binge alcohol drinking has emerged as a typical phenomenon in young people. This pattern of drinking, repeatedly leading to extremely high blood and brain alcohol levels and intoxication is associated with severe risks of neurodegeneration and cognitive damage. Mechanisms involved in excitotoxicity and neuroinflammation are pivotal elements in alcohol-induced neurotoxicity. Evidence has demonstrated that PPARγ receptor activation shows anti-inflammatory and neuroprotective properties. Here we examine whether treatment with the PPARγ agonist pioglitazone is beneficial in counteracting neurodegeneration, neuroinflammation and cognitive damage produced by binge alcohol intoxication. Adult Wistar rats were subjected to a 4-day binge intoxication procedure, which is commonly used to model excessive alcohol consumption in humans. Across the 4-day period, pioglitazone (0, 30, 60mg/kg) was administered orally twice daily at 12-h intervals. Degenerative cells were detected by fluoro-jade B (FJ-B) immunostaining in brain regions where expression of pro-inflammatory cytokines was also determined. The effects of pioglitazone on cognitive function were assessed in an operant reversal learning task and the Morris water maze task. Binge alcohol exposure produced selective neuronal degeneration in the hippocampal dentate gyrus and the adjacent entorhinal cortex. Pioglitazone reduced FJ-B positive cells in both regions and prevented alcohol-induced expression of pro-inflammatory cytokines. Pioglitazone also rescued alcohol-impaired reversal learning in the operant task and spatial learning deficits in the Morris water maze. These findings demonstrate that activation of PPARγ protects against neuronal and cognitive degeneration elicited by binge alcohol exposure. The protective effect of PPARγ agonist appears to be linked to inhibition of pro-inflammatory cytokines.
Asunto(s)
Conducta Animal/efectos de los fármacos , Etanol/toxicidad , Hipocampo/efectos de los fármacos , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/administración & dosificación , PPAR gamma/agonistas , Tiazolidinedionas/administración & dosificación , Animales , Nivel de Alcohol en Sangre , Citocinas/metabolismo , Etanol/administración & dosificación , Hipocampo/metabolismo , Hipocampo/patología , Masculino , Actividad Motora/efectos de los fármacos , Neuronas/patología , Pioglitazona , Ratas Wistar , Aprendizaje Espacial/efectos de los fármacos , Memoria Espacial/efectos de los fármacosRESUMEN
T-helper cells that produce interleukin-17 (T(H)17 cells) are a recently identified CD4(+) T-cell subset with characterized pathological roles in autoimmune diseases. The nuclear receptors retinoic-acid-receptor-related orphan receptors α and γt (RORα and RORγt, respectively) have indispensible roles in the development of this cell type. Here we present SR1001, a high-affinity synthetic ligand-the first in a new class of compound-that is specific to both RORα and RORγt and which inhibits T(H)17 cell differentiation and function. SR1001 binds specifically to the ligand-binding domains of RORα and RORγt, inducing a conformational change within the ligand-binding domain that encompasses the repositioning of helix 12 and leads to diminished affinity for co-activators and increased affinity for co-repressors, resulting in suppression of the receptors' transcriptional activity. SR1001 inhibited the development of murine T(H)17 cells, as demonstrated by inhibition of interleukin-17A gene expression and protein production. Furthermore, SR1001 inhibited the expression of cytokines when added to differentiated murine or human T(H)17 cells. Finally, SR1001 effectively suppressed the clinical severity of autoimmune disease in mice. Our data demonstrate the feasibility of targeting the orphan receptors RORα and RORγt to inhibit specifically T(H)17 cell differentiation and function, and indicate that this novel class of compound has potential utility in the treatment of autoimmune diseases.
Asunto(s)
Autoinmunidad/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Sulfonamidas/farmacología , Células Th17/citología , Células Th17/inmunología , Tiazoles/farmacología , Animales , Autoinmunidad/inmunología , Agonismo Inverso de Drogas , Células HEK293 , Humanos , Interleucina-17/biosíntesis , Interleucina-17/inmunología , Interleucinas/biosíntesis , Interleucinas/inmunología , Ligandos , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Miembro 1 del Grupo F de la Subfamilia 1 de Receptores Nucleares/antagonistas & inhibidores , Miembro 1 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Miembro 1 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/antagonistas & inhibidores , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Células Th17/efectos de los fármacos , Células Th17/metabolismoRESUMEN
BACKGROUND: Fetal alcohol spectrum disorders (FASD) result from fetal exposure to alcohol and are the leading cause of mental retardation in the United States. There is currently no effective treatment that targets the causes of these disorders. Thus, novel therapies are critically needed to limit the neurodevelopmental and neurodegenerative pathologies associated with FASD. METHODS: A neonatal mouse FASD model was used to examine the role of the neuroimmune system in ethanol (EtOH)-induced neuropathology. Neonatal C57BL/6 mice were treated with EtOH, with or without pioglitazone, on postnatal days 4 through 9, and tissue was harvested 1 day post treatment. Pioglitazone is a peroxisome proliferator-activated receptor (PPAR)-γ agonist that exhibits anti-inflammatory activity and is neuroprotective. We compared the effects of EtOH with or without pioglitazone on cytokine and chemokine expression and microglial morphology in the hippocampus, cerebellum, and cerebral cortex. RESULTS: In EtOH-treated animals compared with controls, cytokines interleukin-1ß and tumor necrosis factor-α mRNA levels were increased significantly in the hippocampus, cerebellum, and cerebral cortex. Chemokine CCL2 mRNA was increased significantly in the hippocampus and cerebellum. Pioglitazone effectively blocked the EtOH-induced increase in the cytokines and chemokine in all tissues to the level expressed in handled-only and vehicle-treated control animals. EtOH also produced a change in microglial morphology in all brain regions that was indicative of microglial activation, and pioglitazone blocked this EtOH-induced morphological change. CONCLUSIONS: These studies indicate that EtOH activates microglia to a pro-inflammatory stage and also increases the expression of neuroinflammatory cytokines and chemokines in diverse regions of the developing brain. Further, the anti-inflammatory and neuroprotective PPAR-γ agonist pioglitazone blocked these effects. It is proposed that microglial activation and inflammatory molecules expressed as a result of EtOH treatment during brain development contribute to the sequelae associated with FASD. Thus, pioglitazone and anti-inflammatory pharmaceuticals more broadly have potential as novel therapeutics for FASD.
Asunto(s)
Modelos Animales de Enfermedad , Etanol/toxicidad , Trastornos del Espectro Alcohólico Fetal/prevención & control , Inmunidad Celular/efectos de los fármacos , Microglía/efectos de los fármacos , Tiazolidinedionas/farmacología , Animales , Cerebelo/efectos de los fármacos , Cerebelo/metabolismo , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Etanol/antagonistas & inhibidores , Femenino , Trastornos del Espectro Alcohólico Fetal/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Inmunidad Celular/fisiología , Ratones , Ratones Endogámicos C57BL , Microglía/metabolismo , Pioglitazona , Embarazo , Tiazolidinedionas/uso terapéuticoRESUMEN
BACKGROUND: Alcohol use occurs across the life span beginning in adolescence and continuing through adulthood. Ethanol (EtOH)-induced pathology varies with age and includes changes in neurogenesis, neurodegeneration, and glial cell activation. EtOH-induced changes in glial activation and immune activity are believed to contribute to EtOH-induced neuropathology. Recent studies indicate an emerging role of glial-derived neuroimmune molecules in alcohol abuse and addiction. METHODS: Adolescent and adult C57BL/6 mice were treated via gavage with 6 g/kg EtOH for 10 days, and tissue was harvested 1 day post treatment. We compared the effects of EtOH on chemokine and cytokine expression and astrocyte glial fibrillary acidic protein (GFAP) immunostaining and morphology in the hippocampus, cerebellum, and cerebral cortex. RESULTS: EtOH increased mRNA levels of the chemokine CCL2/MCP-1 in all 3 regions of adult mice relative to controls. The cytokine interleukin-6 (IL-6) was selectively increased only in the adult cerebellum. EtOH did not affect mRNA levels of the cytokine tumor necrosis factor-alpha (TNF-α) in any of these brain regions in adult animals. Interestingly, CCL2, IL-6, and TNF-α mRNA levels were not increased in the hippocampus, cerebellum, or cortex of adolescent mice. EtOH treatment of adult and adolescent mice resulted in increased GFAP immunostaining. CONCLUSIONS: Collectively, these data indicate an age- and region-specific susceptibility to EtOH regulation of neuroinflammatory and addiction-related molecules as well as astrocyte phenotype. These studies may have important implications concerning differential alcohol-induced neuropathology and alcohol addiction across the life span.
Asunto(s)
Envejecimiento/inmunología , Encéfalo/efectos de los fármacos , Encéfalo/inmunología , Depresores del Sistema Nervioso Central/farmacología , Etanol/farmacología , Inmunidad/efectos de los fármacos , Envejecimiento/fisiología , Animales , Astrocitos/efectos de los fármacos , Astrocitos/inmunología , Cerebelo/citología , Cerebelo/efectos de los fármacos , Cerebelo/inmunología , Corteza Cerebral/citología , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/inmunología , Quimiocina CCL2/biosíntesis , ADN Complementario/biosíntesis , ADN Complementario/aislamiento & purificación , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipocampo/citología , Hipocampo/efectos de los fármacos , Hipocampo/inmunología , Inmunidad Celular/efectos de los fármacos , Inmunohistoquímica , Interleucina-6/biosíntesis , Ratones Endogámicos C57BL , ARN/biosíntesis , ARN/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
Fetal alcohol spectrum disorders (FASD) caused by developmental ethanol exposure lead to cerebellar impairments, including motor problems, decreased cerebellar weight, and cell death. Alterations in the sole output of the cerebellar cortex, Purkinje cells, and central nervous system immune cells, microglia, have been reported in animal models of FASD. To determine how developmental ethanol exposure affects adult cerebellar microglia and Purkinje cells, we used a human third-trimester binge exposure model in which mice received ethanol or saline from postnatal (P) days 4-9. In adolescence, cerebellar cranial windows were implanted and mice were aged to young adulthood for examination of microglia and Purkinje cells in vivo with two-photon imaging or in fixed tissue. Ethanol had no effect on microglia density, morphology, dynamics, or injury response. However, Purkinje cell linear frequency was reduced by ethanol. Microglia-Purkinje cell interactions in the Purkinje Cell Layer were altered in females compared to males. Overall, developmental ethanol exposure had few effects on cerebellar microglia in young adulthood and Purkinje cells appeared to be more susceptible to its effects.
Asunto(s)
Etanol , Trastornos del Espectro Alcohólico Fetal , Embarazo , Masculino , Humanos , Femenino , Animales , Ratones , Adulto Joven , Adulto , Anciano , Etanol/farmacología , Células de Purkinje , Trastornos del Espectro Alcohólico Fetal/etiología , Trastornos del Espectro Alcohólico Fetal/metabolismo , Microglía/metabolismo , Cerebelo/metabolismo , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: Alcohol abuse has dramatic effects on the health of the elderly. Recent studies indicate that ethanol increases immune activity in younger animals and that some of these proinflammatory molecules alter alcohol consumption and addiction. However, the effects of alcohol on immune activation in aged animals have not been thoroughly investigated. FINDINGS: We compared the effects of ethanol on chemokine and cytokine expression in the hippocampus, cerebellum, and cerebral cortex of aged C57BL/6 mice. Mice were treated via gavage with 6 g/kg ethanol for 10 days and tissue was harvested 1 day post-treatment. Ethanol selectively increased mRNA levels of the chemokine (C-C motif) ligand 2/monocyte chemotactic protein-1 in the hippocampus and cerebellum, but not in the cortex of aged mice relative to control animals. In this paradigm, ethanol did not affect mRNA levels of the cytokines IL-6 or TNF-α in any of these brain regions in aged animals. CONCLUSIONS: Collectively, these data indicate a region-specific susceptibility to ethanol regulation of neuroinflammatory and addiction-related molecules in aged mice. These studies could have important implications concerning alcohol-induced neuropathology and alcohol addiction in the elderly.
Asunto(s)
Envejecimiento/inmunología , Envejecimiento/fisiología , Encéfalo/efectos de los fármacos , Encéfalo/inmunología , Depresores del Sistema Nervioso Central/farmacología , Etanol/farmacología , Inmunidad/efectos de los fármacos , Animales , Depresores del Sistema Nervioso Central/sangre , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Quimiocina CCL2/biosíntesis , ADN Complementario/biosíntesis , Etanol/sangre , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Ratones , Ratones Endogámicos C57BL , ARN/biosíntesis , ARN/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Ethanol induces neuroinflammation, which is believed to contribute to the pathogenesis of alcohol use disorder (AUD). Toll-like receptors (TLRs) are a group of pattern recognition receptors (PRRs) expressed on both immune cells, including microglia and astrocytes, and non-immune cells in the central nervous system (CNS). Studies have shown that alcohol activates TLR4 signaling, resulting in the induction of pro-inflammatory cytokines and chemokines in the CNS. However, the effect of alcohol on signaling pathways downstream of TLR4, such as MyD88 and TRIF (TICAM) signaling, has not been evaluated extensively. In the current study, we treated male wild-type, TLR4-, MyD88-, and TRIF-deficient mice using a chronic plus binge mouse model of AUD. Evaluation of mRNA expression by qRT-PCR revealed that ethanol increased IL-1ß, TNF-α, CCL2, COX2, FosB, and JunB in the cerebellum in wild-type and TRIF-deficient mice, while ethanol generally did not increase the expression of these molecules in TLR4- and MyD88-deficient mice. Furthermore, IRF3, IRF7, and IFN-ß1, which are associated with the TRIF-dependent signaling cascade, were largely unaffected by alcohol. Collectively, these results suggest that the TLR4 and downstream MyD88-dependent signaling pathways are essential in ethanol-induced neuroinflammation in this mouse model of AUD.
Asunto(s)
Alcoholismo , Masculino , Animales , Ratones , Etanol , Factor 88 de Diferenciación Mieloide , Receptor Toll-Like 4 , Enfermedades Neuroinflamatorias , Proteínas Adaptadoras Transductoras de Señales , Modelos Animales de Enfermedad , Proteínas Adaptadoras del Transporte VesicularRESUMEN
Alcohol use disorder (AUD) is one of the most common preventable mental health disorders and can result in pathology within the CNS, including the cerebellum. Cerebellar alcohol exposure during adulthood has been associated with disruptions in proper cerebellar function. However, the mechanisms regulating ethanol-induced cerebellar neuropathology are not well understood. High-throughput next generation sequencing was performed to compare control versus ethanol-treated adult C57BL/6J mice in a chronic plus binge model of AUD. Mice were euthanized, cerebella were microdissected, and RNA was isolated and submitted for RNA-sequencing. Down-stream transcriptomic analyses revealed significant changes in gene expression and global biological pathways in control versus ethanol-treated mice that included pathogen-influenced signaling pathways and cellular immune response pathways. Microglial-associated genes showed a decrease in homeostasis-associated transcripts and an increase in transcripts associated with chronic neurodegenerative diseases, while astrocyte-associated genes showed an increase in transcripts associated with acute injury. Oligodendrocyte lineage cell genes showed a decrease in transcripts associated with both immature progenitors as well as myelinating oligodendrocytes. These data provide new insight into the mechanisms by which ethanol induces cerebellar neuropathology and alterations to the immune response in AUD.
Asunto(s)
Alcoholismo , Etanol , Ratones , Animales , Etanol/metabolismo , Alcoholismo/patología , Enfermedades Neuroinflamatorias , Transcriptoma , Ratones Endogámicos C57BL , Cerebelo/metabolismo , Enfermedad Crónica , ARN/metabolismoRESUMEN
Fetal alcohol spectrum disorders (FASD) are a group of neurodevelopmental disorders caused by ethanol exposure in utero, which can result in neurocognitive and behavioral impairments, growth defects, and craniofacial anomalies. FASD affects up to 1-5% of school-aged children in the United States, and there is currently no cure. The underlying mechanisms involved in ethanol teratogenesis remain elusive and need greater understanding to develop and implement effective therapies. Using a third trimester human equivalent postnatal mouse model of FASD, we evaluate the transcriptomic changes induced by ethanol exposure in the cerebellum on P5 and P6, after only 1 or 2 days of ethanol exposure, with the goal of shedding light on the transcriptomic changes induced early during the onset and development of FASD. We have highlighted key pathways and cellular functions altered by ethanol exposure, which include pathways related to immune function and cytokine signaling as well as the cell cycle. Additionally, we found that ethanol exposure resulted in an increase in transcripts associated with a neurodegenerative microglia phenotype, and acute- and pan-injury reactive astrocyte phenotypes. Mixed effects on oligodendrocyte lineage cell associated transcripts and cell cycle associated transcripts were observed. These studies help to elucidate the underlying mechanisms that may be involved with the onset of FASD and provide further insights that may aid in identifying novel targets for interventions and therapeutics.
RESUMEN
Introduction: Fetal alcohol spectrum disorders (FASD) are the most common cause of non-heritable, preventable mental disability, occurring in almost 5% of births in the United States. FASD lead to physical, behavioral, and cognitive impairments, including deficits related to the cerebellum. There is no known cure for FASD and their mechanisms remain poorly understood. To better understand these mechanisms, we examined the cerebellum on a cellular level by studying microglia, the principal immune cells of the central nervous system, and Purkinje cells, the sole output of the cerebellum. Both cell types have been shown to be affected in models of FASD, with increased cell death, immune activation of microglia, and altered firing in Purkinje cells. While ethanol administered in adulthood can acutely depress the dynamics of the microglial process arbor, it is unknown how developmental ethanol exposure impacts microglia dynamics and their interactions with Purkinje cells in the long term. Methods: To address this question, we used a mouse model of human 3rd trimester exposure, whereby L7cre/Ai9+/-/Cx3cr1G/+ mice (with fluorescently labeled microglia and Purkinje cells) of both sexes were subcutaneously treated with a binge-level dose of ethanol (5.0 g/kg/day) or saline from postnatal days 4-9. Cranial windows were implanted in adolescent mice above the cerebellum to examine the long-term effects of developmental ethanol exposure on cerebellar microglia and Purkinje cell interactions using in vivo two-photon imaging. Results: We found that cerebellar microglia dynamics and morphology were not affected after developmental ethanol exposure. Microglia dynamics were also largely unaltered with respect to how they interact with Purkinje cells, although subtle changes in these interactions were observed in females in the molecular layer of the cerebellum. Discussion: This work suggests that there are limited in vivo long-term effects of ethanol exposure on microglia morphology, dynamics, and neuronal interactions, so other avenues of research may be important in elucidating the mechanisms of FASD.
RESUMEN
Inflammatory molecules have been implicated in the pathogenesis of neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and multiple sclerosis. Resveratrol is an anti-fungal compound found in the skins of red grapes and other fruits and nuts. We examined the ability of resveratrol to inhibit lipopolysaccharide (LPS)-induced production of inflammatory molecules from primary mouse astrocytes. Resveratrol inhibited LPS-induced production of nitric oxide (NO); the cytokines tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1ß), and IL-6; and the chemokine monocyte chemotactic protein-1 (MCP-1), which play critical roles in innate immunity, by astrocytes. Resveratrol also suppressed astrocyte production of IL-12p40 and IL-23, which are known to alter the phenotype of T cells involved in adaptive immunity. Finally resveratrol inhibited astrocyte production of C-reactive protein (CRP), which plays a role in a variety of chronic inflammatory disorders. Collectively, these studies suggest that resveratrol may be an effective therapeutic agent in neurodegenerative diseases initiated or maintained by inflammatory processes.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Astrocitos/efectos de los fármacos , Enfermedades Neurodegenerativas/inmunología , Estilbenos/farmacología , Animales , Antiinflamatorios no Esteroideos/uso terapéutico , Astrocitos/inmunología , Astrocitos/patología , Proteína C-Reactiva/antagonistas & inhibidores , Proteína C-Reactiva/metabolismo , Células Cultivadas , Quimiocina CCL2/metabolismo , Citocinas/metabolismo , Subunidad p40 de la Interleucina-12/antagonistas & inhibidores , Subunidad p40 de la Interleucina-12/metabolismo , Interleucina-23/antagonistas & inhibidores , Interleucina-23/metabolismo , Lipopolisacáridos/inmunología , Ratones , Enfermedades Neurodegenerativas/tratamiento farmacológico , Óxido Nítrico/metabolismo , Resveratrol , Estilbenos/uso terapéuticoRESUMEN
BACKGROUND: Cross-sectional magnetic resonance imaging (MRI) studies have generated substantial evidence relating neuroimaging abnormalities to clinical and cognitive decline in multiple sclerosis (MS). Longitudinal neuroimaging studies may have additional value for predicting future cognitive deficits or clinical impairment, potentially leading to earlier interventions and better disease management. We conducted a meta-analysis of longitudinal studies using neuroimaging to predict cognitive decline (i.e. the Symbol Digits Modalities Test, SDMT) and disability outcomes (i.e. the Expanded Disability Status Scale, EDSS) in MS. METHODS: Our systematic literature search yielded 64 relevant publications encompassing 105 distinct sub-analyses. We performed a multilevel random-effects meta-analysis to estimate overall effect size for neuroimaging's ability to predict longitudinal cognitive and clinical decline, and a meta-regression to investigate the impact of distinct study factors on pooled effect size. RESULTS: In the EDSS analyses, the meta-analysis yielded a medium overall pooled effect size (Pearson's correlation coefficient r = 0.42, 95% CI [0.37; 0.46]). The meta-regression further indicated that analyses exclusively evaluating gray matter tissue had significantly stronger effect sizes than analyses of white matter tissue or whole brain analyses (p < 0.05). No other study factors significantly influenced the pooled effect size (all p > 0.05). In the SDMT analyses, the meta-analysis yielded a medium overall pooled effect size (r = 0.47, 95% CI [0.32; 0.60]). The meta-regression found no significant study factors influencing the pooled effect size. CONCLUSION: The present findings indicate that brain imaging is a medium predictor of longitudinal change in both disability progression (EDSS) and cognitive decline (SDMT). These findings reinforce the need for further longitudinal studies standardizing methods, using multimodal approaches, creating data consortiums, and publishing more complete datasets investigating MRI modalities to predict longitudinal disability and cognitive decline.
Asunto(s)
Trastornos del Conocimiento , Esclerosis Múltiple , Cognición , Humanos , Imagen por Resonancia Magnética , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/diagnóstico por imagen , Neuroimagen , Pruebas NeuropsicológicasRESUMEN
Fetal alcohol spectrum disorders (FASD) result from ethanol exposure to the developing fetus and are the most common cause of mental retardation in the United States. These disorders are characterized by a variety of neurodevelopmental and neurodegenerative anomalies which result in significant lifetime disabilities. Thus, novel therapies are required to limit the devastating consequences of FASD. Neuropathology associated with FASD can occur throughout the central nervous system (CNS), but is particularly well characterized in the developing cerebellum. Rodent models of FASD have previously demonstrated that both Purkinje cells and granule cells, which are the two major types of neurons in the cerebellum, are highly susceptible to the toxic effects of ethanol. The current studies demonstrate that ethanol decreases the viability of cultured cerebellar granule cells and microglial cells. Interestingly, microglia have dual functionality in the CNS. They provide trophic and protective support to neurons. However, they may also become pathologically activated and produce inflammatory molecules toxic to parenchymal cells including neurons. The findings in this study demonstrate that the peroxisome proliferator-activated receptor-γ agonists 15-deoxy-Δ12,15 prostaglandin J2 and pioglitazone protect cultured granule cells and microglia from the toxic effects of ethanol. Furthermore, investigations using a newly developed mouse model of FASD and stereological cell counting methods in the cerebellum elucidate that ethanol administration to neonates is toxic to both Purkinje cell neurons as well as microglia, and that in vivo administration of PPAR-γ agonists protects these cells. In composite, these studies suggest that PPAR-γ agonists may be effective in limiting ethanol-induced toxicity to the developing CNS.