RESUMEN
Regulatory brain cytoplasmic 200 RNA (BC200 RNA) is highly expressed in human mammary carcinoma cells. Here, we ask whether BC200 RNA becomes detectable in peripheral blood of patients with invasive breast cancer. Using quantitative reverse-transcription PCR (qRT-PCR) methodology, we observed that BC200 RNA blood levels were significantly elevated, in comparison with healthy subjects, in patients with invasive breast cancer prior to tumorectomy (p=0.001) and in patients with metastatic breast cancer (p=0.003). In patients with invasive breast cancer who had recently undergone tumorectomy, BC200 RNA blood levels were not distinguishable from levels in healthy subjects. However, normality analysis revealed a heterogeneous distribution of patients in this group, including a subgroup of individuals with high residual BC200 RNA blood levels. In blood from patients with invasive breast cancer, BC200 RNA was specifically detected in the mononuclear leukocyte fraction. The qRT-PCR approach is sensitive enough to detect as few as three BC200 RNA-expressing tumor cells. Our work establishes the potential of BC200 RNA detection in blood to serve as a molecular indicator of invasive breast malignancy.
Asunto(s)
Neoplasias de la Mama/sangre , Neoplasias de la Mama/genética , ARN Largo no Codificante/sangre , ARN Largo no Codificante/genética , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Células MCF-7 , Persona de Mediana Edad , Invasividad Neoplásica , Curva ROC , Sensibilidad y EspecificidadRESUMEN
The role of insulin in the brain is still not completely understood. In the periphery, insulin can decrease inflammation induced by lipopolysaccharide (LPS); however, whether insulin can reduce inflammation within the brain is unknown. Experiments administrating intranasal insulin to young and aged adults have shown that insulin improves memory. In our animal model of chronic neuroinflammation, we administered insulin and/or LPS directly into the brain via the fourth ventricle for 4 weeks in young rats; we then analyzed their spatial memory and neuroinflammatory response. Additionally, we administered insulin or artificial cerebral spinal fluid (aCSF), in the same manner, to aged rats and then analyzed their spatial memory and neuroinflammatory response. Response to chronic neuroinflammation in young rats was analyzed in the presence or absence of insulin supplementation. Here, we show for the first time that insulin infused (i.c.v.) to young rats significantly attenuated the effects of LPS by decreasing the expression of neuroinflammatory markers in the hippocampus and by improving performance in the Morris water pool task. In young rats, insulin infusion alone significantly improved their performance as compared to all other groups. Unexpectedly, in aged rats, the responsiveness to insulin was completely absent, that is, spatial memory was still impaired suggesting that an age-dependent insulin resistance may contribute to the cognitive impairment observed in neurodegenerative diseases. Our data suggest a novel therapeutic effect of insulin on neuroinflammation in the young but not the aged brain.
Asunto(s)
Envejecimiento , Encefalitis/complicaciones , Encefalitis/patología , Hipocampo/metabolismo , Insulina/uso terapéutico , Trastornos de la Memoria/tratamiento farmacológico , Análisis de Varianza , Animales , Citocinas/genética , Citocinas/metabolismo , Modelos Animales de Enfermedad , Encefalitis/inducido químicamente , Encefalitis/tratamiento farmacológico , Regulación de la Expresión Génica/efectos de los fármacos , Hipocampo/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Trastornos de la Memoria/etiología , Proteína Quinasa C/metabolismo , Ratas , Ratas Endogámicas F344 , Tiempo de Reacción/efectos de los fármacos , Memoria Espacial/efectos de los fármacosRESUMEN
BACKGROUND: Chronic neuroinflammation and calcium (Ca(+2)) dysregulation are both components of Alzheimer's disease. Prolonged neuroinflammation produces elevation of pro-inflammatory cytokines and reactive oxygen species which can alter neuronal Ca(+2) homeostasis via L-type voltage-dependent Ca(+2) channels (L-VDCCs) and ryanodine receptors (RyRs). Chronic neuroinflammation also leads to deficits in spatial memory, which may be related to Ca(+2) dysregulation. METHODS: The studies herein use an in vivo model of chronic neuroinflammation: rats were infused intraventricularly with a continuous small dose of lipopolysaccharide (LPS) or artificial cerebrospinal fluid (aCSF) for 28 days. The rats were treated with the L-VDCC antagonist nimodipine or the RyR antagonist dantrolene. RESULTS: LPS-infused rats had significant memory deficits in the Morris water maze, and this deficit was ameliorated by treatment with nimodipine. Synaptosomes from LPS-infused rats had increased Ca(+2) uptake, which was reduced by a blockade of L-VDCCs either in vivo or ex vivo. CONCLUSIONS: Taken together, these data indicate that Ca(+2) dysregulation during chronic neuroinflammation is partially dependent on increases in L-VDCC function. However, blockade of the RyRs also slightly improved spatial memory of the LPS-infused rats, demonstrating that other Ca(+2) channels are dysregulated during chronic neuroinflammation. Ca(+2)-dependent immediate early gene expression was reduced in LPS-infused rats treated with dantrolene or nimodipine, indicating normalized synaptic function that may underlie improvements in spatial memory. Pro-inflammatory markers are also reduced in LPS-infused rats treated with either drug. Overall, these data suggest that Ca(+2) dysregulation via L-VDCCs and RyRs play a crucial role in memory deficits resulting from chronic neuroinflammation.
Asunto(s)
Canales de Calcio Tipo L/metabolismo , Calcio/metabolismo , Encefalitis/complicaciones , Encefalitis/patología , Trastornos de la Memoria/etiología , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Complejo Relacionado con el SIDA/metabolismo , Análisis de Varianza , Animales , Bloqueadores de los Canales de Calcio/uso terapéutico , Canales de Calcio Tipo L/genética , Enfermedad Crónica , Dantroleno/uso terapéutico , Modelos Animales de Enfermedad , Encefalitis/inducido químicamente , Encefalitis/tratamiento farmacológico , Regulación de la Expresión Génica/efectos de los fármacos , Lipopolisacáridos/toxicidad , Aprendizaje por Laberinto/efectos de los fármacos , Trastornos de la Memoria/tratamiento farmacológico , Relajantes Musculares Centrales/uso terapéutico , Nimodipina/uso terapéutico , Ratas , Ratas Endogámicas F344 , Canal Liberador de Calcio Receptor de Rianodina/genética , Memoria Espacial/efectos de los fármacosRESUMEN
Insulin receptor (IR) in the brain plays a role in synaptic plasticity and cognitive functions. Phosphorylation of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors GluR1 subunit at Serine 831 is regulated by calcium-calmodulin-dependent protein kinase II and protein kinase C that underlie long-term potentiation and learning/memory. Recent studies have shown that the novel Protein Kinase M zeta (PKMζ) underlies synaptic plasticity and may regulate AMPAr. In this study, we show that insulin induces phosphorylation of Serine 831 GluR1 subunit of AMPAr and induces over-expression of PKMζ; pre-treatment with either the IR inhibitor 3-Bromo-5-t-butyl-4-hydroxy-benzylidenemalonitrile (AG1024) or PKMζ inhibitor protein kinase C zeta pseudo-substrate inhibitor returned the phosphorylation value of GluR1 to control level. Amyloid beta (Aß) peptide in the form of oligomers interferes with IR signaling. Pre-treating neuronal cultures with Aß following incubation with insulin, we found a reduction of insulin-dependent PKMζ over-expression and MAPK/Erk (1/2) phosphorylation, i.e., signaling pathways involved in synaptic plasticity and learning/memory. These results indicate a new intracellular insulin signaling pathway, and, additionally, that insulin resistance in Alzheimer's disease is a response to the production and accumulation of Aß.