RESUMEN
Most diseases of older age have as their common denominator a dysfunctional immune system, wherein a low, chronic level of inflammation is present due to an imbalance of pro-inflammatory cytokines over anti-inflammatory cytokines that develops during aging ("inflamm-aging"). A gerotherapeutic that can restore the immune balance to that shared by young/middle-aged adults and many centenarians could reduce the risk of those age-related diseases and increase healthy longevity. In this perspectives paper, we discuss potential longevity interventions that are being evaluated and compare them to a novel gerotherapeutic currently being evaluated in humans-Transcranial Electromagnetic Wave Treatment (TEMT). TEMT is provided non-invasively and safety through a novel bioengineered medical device-the MemorEM-that allows for near complete mobility during in-home treatments. Daily TEMT to mild/moderate Alzheimer's Disease (AD) patients over a 2-month period rebalanced 11 of 12 cytokines in blood back to that of normal aged adults. A very similar TEMT-induced rebalancing of cytokines occurred in the CSF/brain for essentially all seven measurable cytokines. Overall inflammation in both blood and brain was dramatically reduced by TEMT over a 14-27 month period, as measured by C-Reactive Protein. In these same AD patients, a reversal of cognitive impairment was observed at 2 months into treatment, while cognitive decline was stopped over a 2½ year period of TEMT. Since most age-related diseases have the commonality of immune imbalance, it is reasonable to postulate that TEMT could rebalance the immune system in many age-related diseases as it appears to do in AD. We propose that TEMT has the potential to reduce the risk/severity of age-related diseases by rejuvenating the immune system to a younger age, resulting in reduced brain/body inflammation and a substantial increase in healthy longevity.
Asunto(s)
Enfermedad de Alzheimer , Longevidad , Adulto , Anciano de 80 o más Años , Humanos , Persona de Mediana Edad , Envejecimiento , Enfermedad de Alzheimer/metabolismo , Citocinas , Inflamación/terapia , Estimulación Transcraneal de Corriente Directa , Radiación ElectromagnéticaRESUMEN
Background: There is currently no therapeutic that can stop or reverse the progressive memory impairment of Alzheimer's disease (AD). However, we recently published that 2 months of daily, in-home transcranial electromagnetic treatment (TEMT) reversed the cognitive impairment in eight mild/moderate AD subjects. These cognitive enhancements were accompanied by predicted changes in AD markers within both the blood and cerebrospinal fluid (CSF). Methods: In view of these encouraging findings, the initial clinical study was extended twice to encompass a period of 2½ years. The present study reports on the resulting long-term safety, cognitive assessments, and AD marker evaluations from the five subjects who received long-term treatment. Results: TEMT administration was completely safe over the 2½-year period, with no deleterious side effects. In six cognitive/functional tasks (including the ADAS-cog13, Rey AVLT, MMSE, and ADL), no decline in any measure occurred over this 2½-year period. Long-term TEMT induced reductions in the CSF levels of C-reactive protein, p-tau217, Aß1-40, and Aß1-42 while modulating CSF oligomeric Aß levels. In the plasma, long-term TEMT modulated/rebalanced levels of both p-tau217 and total tau. Conclusions: Although only a limited number of AD patients were involved in this study, the results suggest that TEMT can stop the cognitive decline of AD over a period of at least 2½ years and can do so with no safety issues.
RESUMEN
Background: The immune system plays a critical role in the development and progression of Alzheimer's disease (AD). However, there is disagreement as to whether development/progression of AD involves an over-activation or an under-activation of the immune system. In either scenario, the immune system's cytokine levels are abnormal in AD and in need of rebalancing. We have recently published a pilot clinical trial (https://clinicaltrials.gov/ct2/show/NCT02958930) showing that 2 months of daily in-home Transcranial Electromagnetic Treatment (TEMT) was completely safe and resulted in reversal of AD cognitive impairment. Methods: For the eight mild/moderate AD subjects in this published work, the present study sought to determine if their TEMT administration had immunologic effects on blood or CSF levels of 12 cytokines. Subjects were given daily in-home TEMT for 2 months by their caregivers, utilizing first-in-class MemorEM™ devices. Results: For eight plasma cytokines, AD subjects with lower baseline cytokine levels always showed increases in those cytokines after both a single treatment or after 2-months of daily TEMT. By contrast, those AD subjects with higher baseline cytokine levels in plasma showed treatment-induced decreases in plasma cytokines at both time points. Thus, a gravitation to reported normal plasma cytokine levels (i.e., a "rebalancing") occurred with both acute and long-term TEMT. In the CSF, TEMT-induced a similar rebalancing for seven measurable cytokines, the direction and extent of changes in individual subjects also being linked to their baseline CSF levels. Conclusion: Our results strongly suggest that daily TEMT to AD subjects for 2-months can "rebalance" levels for 11 of 12 cytokines in blood and/or brain, which is associated with reversal of their cognitive impairment. TEMT is likely to be providing these immunoregulatory effects by affecting cytokine secretion from: (1) blood cells traveling through the head's vasculature, and (2) the brain's microglia/astrocytes, choroid plexus, or neurons. This rebalancing of so many cytokines, and in both brain and systemic compartments, appears to be a remarkable new mechanism of TEMT action that may contribute substantially to it's potential to prevent, stop, or reverse AD and other diseases of aging.
RESUMEN
BACKGROUND: Small aggregates (oligomers) of the toxic proteins amyloid-ß (Aß) and phospho-tau (p-tau) are essential contributors to Alzheimer's disease (AD). In mouse models for AD or human AD brain extracts, Transcranial Electromagnetic Treatment (TEMT) disaggregates both Aß and p-tau oligomers, and induces brain mitochondrial enhancement. These apparent "disease-modifying" actions of TEMT both prevent and reverse memory impairment in AD transgenic mice. OBJECTIVE: To evaluate the safety and initial clinical efficacy of TEMT against AD, a comprehensive open-label clinical trial was performed. METHODS: Eight mild/moderate AD patients were treated with TEMT in-home by their caregivers for 2 months utilizing a unique head device. TEMT was given for two 1-hour periods each day, with subjects primarily evaluated at baseline, end-of-treatment, and 2 weeks following treatment completion. RESULTS: No deleterious behavioral effects, discomfort, or physiologic changes resulted from 2 months of TEMT, as well as no evidence of tumor or microhemorrhage induction. TEMT induced clinically important and statistically significant improvements in ADAS-cog, as well as in the Rey AVLT. TEMT also produced increases in cerebrospinal fluid (CSF) levels of soluble Aß1-40 and Aß1-42, cognition-related changes in CSF oligomeric Aß, a decreased CSF p-tau/Aß1-42 ratio, and reduced levels of oligomeric Aß in plasma. Pre- versus post-treatment FDG-PET brain scans revealed stable cerebral glucose utilization, with several subjects exhibiting enhanced glucose utilization. Evaluation of diffusion tensor imaging (fractional anisotropy) scans in individual subjects provided support for TEMT-induced increases in functional connectivity within the cognitively-important cingulate cortex/cingulum. CONCLUSION: TEMT administration to AD subjects appears to be safe, while providing cognitive enhancement, changes to CSF/blood AD markers, and evidence of stable/enhanced brain connectivity.
Asunto(s)
Enfermedad de Alzheimer/terapia , Estimulación Magnética Transcraneal/métodos , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/psicología , Péptidos beta-Amiloides/sangre , Péptidos beta-Amiloides/líquido cefalorraquídeo , Cognición , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neuroimagen , Pruebas Neuropsicológicas , Estimulación Magnética Transcraneal/efectos adversos , Resultado del Tratamiento , Proteínas tau/sangre , Proteínas tau/líquido cefalorraquídeoRESUMEN
We have demonstrated in multiple studies that daily, long-term electromagnetic field (EMF) treatment in the ultra-high frequency range not only protects Alzheimer's disease (AD) transgenic mice from cognitive impairment, but also reverses such impairment in aged AD mice. Moreover, these beneficial cognitive effects appear to be through direct actions on the AD process. Based on a large array of pre-clinical data, we have initiated a pilot clinical trial to determine the safety and efficacy of EMF treatment to mild-moderate AD subjects. Since it is important to establish the safety of this new neuromodulatory approach, the main purpose of this review is to provide a comprehensive assessment of evidence supporting the safety of EMFs, particularly through transcranial electromagnetic treatment (TEMT). In addition to our own pre-clinical studies, a rich variety of both animal and cell culture studies performed by others have underscored the anticipated safety of TEMT in clinical AD trials. Moreover, numerous clinical studies have determined that short- or long-term human exposure to EMFs similar to those to be provided clinically by TEMT do not have deleterious effects on general health, cognitive function, or a variety of physiologic measures-to the contrary, beneficial effects on brain function/activity have been reported. Importantly, such EMF exposure has not been shown to increase the risk of any type of cancer in human epidemiologic studies, as well as animal and cell culture studies. In view of all the above, clinical trials of safety/efficacy with TEMT to AD subjects are clearly warranted and now in progress.
Asunto(s)
Enfermedad de Alzheimer/terapia , Encéfalo/fisiología , Magnetoterapia/métodos , Enfermedad de Alzheimer/genética , Animales , Neoplasias Encefálicas , Modelos Animales de Enfermedad , Humanos , ImanesRESUMEN
Transcription factors are involved to varying extents in the health and survival of neurons in the brain and a better understanding of their roles with respect to the pathogenesis of Alzheimer's disease (AD) could lead to the development of additional treatment strategies. Sp1 is a transcription factor that responds to inflammatory signals occurring in the AD brain. It is known to regulate genes with demonstrated importance in AD, and we have previously found it upregulated in the AD brain and in brains of transgenic AD model mice. To better understand the role of Sp1 in AD, we tested whether we could affect memory function (measured with a battery of behavioral tests discriminating different aspects of cognitive function) in a transgenic model of AD by pharmaceutical modulation of Sp1. We found that inhibition of Sp1 function in transgenic AD model mice increased memory deficits, while there were no changes in sensorimotor or anxiety tests. Aß42 and Aß40 peptide levels were significantly higher in the treated mice, indicating that Sp1 elevation in AD could be a functionally protective response. Circulating levels of CXCL1 (KC) decreased following treatment with mithramycin, while a battery of other cytokines, including IL-1α, IL-6, INF-γ and MCP-1, were unchanged. Gene expression levels for several genes important to neuronal health were determined by qRT-PCR, and none of these appeared to change at the transcriptional level.
RESUMEN
Traumatic brain injury (TBI) has become a signature wound of the wars in Iraq and Afghanistan. Many American soldiers, even those undiagnosed but likely suffering from mild TBI, display Alzheimer's disease (AD)-like cognitive impairments, suggesting a pathological overlap between TBI and AD. This study examined the cognitive and neurohistological effects of TBI in presymptomatic APP/PS1 AD-transgenic mice. AD mice and non-transgenic (NT) mice received an experimental TBI on the right parietal cortex using the controlled cortical impact model. Animals were trained in a water maze task for spatial memory before TBI, and then reevaluated in the same task at two and six weeks post-TBI. The results showed that AD mice with TBI made significantly more errors in the task than AD mice without TBI and NT mice regardless of TBI. A separate group of AD mice and NT mice were evaluated neurohistologically at six weeks after TBI. The number of extracellular beta-amyloid (Aß)-deposits significantly increased by at least one fold in the cortex of AD mice that received TBI compared to the NT mice that received TBI or the AD and NT mice that underwent sham surgery. A significant decrease in MAP2 positive cells, indicating neuronal loss, was observed in the cortex of both the AD and NT mice that received TBI compared to the AD and NT mice subjected to sham surgery. Similar changes in extracellular Aß deposits and MAP2 positive cells were also seen in the hippocampus. These results demonstrate for the first time that TBI precipitates cognitive impairment in presymptomatic AD mice, while also confirming extracellular Aß deposits following TBI. The recognition of this pathological link between TBI and AD should aid in developing novel treatments directed at abrogating cellular injury and extracellular Aß deposition in the brain.
Asunto(s)
Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/metabolismo , Lesiones Encefálicas/fisiopatología , Trastornos del Conocimiento/fisiopatología , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Lesiones Encefálicas/complicaciones , Trastornos del Conocimiento/etiología , Modelos Animales de Enfermedad , Espacio Extracelular/metabolismo , Hipocampo/lesiones , Hipocampo/metabolismo , Humanos , Aprendizaje por Laberinto/fisiología , Memoria/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Ratones Transgénicos , Microscopía Confocal , Lóbulo Parietal/lesiones , Lóbulo Parietal/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo , Factores de TiempoRESUMEN
Caffeine and melatonin have been shown to protect the Swedish mutant amyloid precursor protein (APP(sw)) transgenic mouse model of Alzheimer's disease from cognitive dysfunction. But their mechanisms of action remain incompletely understood. These Alzheimer's mice have extensive mitochondrial dysfunction, which likely contributes to their cognitive decline. To further explore the mechanism through which caffeine and melatonin protect cognitive function in these mice, we monitored the function of isolated mitochondria from APP(sw) mice treated with caffeine, melatonin, or both in their drinking water for one month. Melatonin treatment yielded a near complete restoration of mitochondrial function in assays of respiratory rate, membrane potential, reactive oxygen species production, and ATP levels. Caffeine treatment by itself yielded a small increase in mitochondrial function. However, caffeine largely blocked the large enhancement of mitochondrial function provided by melatonin. Studies with N2a neuroblastoma cells stably expressing APP(sw) showed that specific inhibition of cAMP-dependent phosphodiesterase (PDE) 4 or cGMP-dependent PDE5 also blocked melatonin protection of mitochondrial function, but A(2a) and A1 adenosine receptor antagonists were without effect. Melatonin or caffeine at the concentrations used to modulate mitochondrial function in the cells had no effect on cAMP-dependent PDE activity or cellular cAMP or cGMP levels. Therefore, caffeine and increased cyclic nucleotide levels likely block melatonin signaling to mitochondria by independent mechanisms that do not involve adenosine receptor antagonism. The results of this study indicate that melatonin restores mitochondrial function much more potently than caffeine in APP(sw) transgenic mouse and cell models of Alzheimer's disease.
Asunto(s)
Enfermedad de Alzheimer/patología , Antioxidantes/farmacología , Cafeína/farmacología , Estimulantes del Sistema Nervioso Central/farmacología , Melatonina/antagonistas & inhibidores , Melatonina/farmacología , Mitocondrias/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Adenosina Trifosfato/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Células Cultivadas , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Ensayo de Inmunoadsorción Enzimática , Técnicas In Vitro , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ratones Transgénicos , Enfermedades Mitocondriales/tratamiento farmacológico , Enfermedades Mitocondriales/metabolismo , Neuronas/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Inhibidores de Fosfodiesterasa/farmacología , Hidrolasas Diéster Fosfóricas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , TransfecciónRESUMEN
The universal failure of pharmacologic interventions against Alzheimer's disease (AD) appears largely due to their inability to get into neurons and the fact that most have a single mechanism-of-action. A non-invasive, neuromodulatory approach against AD has consequently emerged: transcranial electromagnetic treatment (TEMT). In AD transgenic mice, long-term TEMT prevents and reverses both cognitive impairment and brain amyloid-ß (Aß) deposition, while TEMT even improves cognitive performance in normal mice. Three disease-modifying and inter-related mechanisms of TEMT action have been identified in the brain: 1) anti-Aß aggregation, both intraneuronally and extracellularly; 2) mitochondrial enhancement; and 3) increased neuronal activity. Long-term TEMT appears safe in that it does not impact brain temperature or oxidative stress levels, nor does it induce any abnormal histologic/anatomic changes in the brain or peripheral tissues. Future TEMT development in both AD mice and normal mice should involve head-only treatment to discover the most efficacious set of parameters for achieving faster and even greater cognitive benefit. Given the already extensive animal work completed, translational development of TEMT could occur relatively quickly to "proof of concept" AD clinical trials. TEMT's mechanisms of action provide extraordinary therapeutic potential against other neurologic disorders/injuries, such as Parkinson's disease, traumatic brain injury, and stroke.
Asunto(s)
Enfermedad de Alzheimer/terapia , Magnetoterapia/métodos , Estimulación Magnética Transcraneal/métodos , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Transgénicos , Presenilina-1/metabolismoRESUMEN
Few studies have investigated physiologic and cognitive effects of "long-term" electromagnetic field (EMF) exposure in humans or animals. Our recent studies have provided initial insight into the long-term impact of adulthood EMF exposure (GSM, pulsed/modulated, 918 MHz, 0.25-1.05 W/kg) by showing 6+ months of daily EMF treatment protects against or reverses cognitive impairment in Alzheimer's transgenic (Tg) mice, while even having cognitive benefit to normal mice. Mechanistically, EMF-induced cognitive benefits involve suppression of brain ß-amyloid (Aß) aggregation/deposition in Tg mice and brain mitochondrial enhancement in both Tg and normal mice. The present study extends this work by showing that daily EMF treatment given to very old (21-27 month) Tg mice over a 2-month period reverses their very advanced brain Aß aggregation/deposition. These very old Tg mice and their normal littermates together showed an increase in general memory function in the Y-maze task, although not in more complex tasks. Measurement of both body and brain temperature at intervals during the 2-month EMF treatment, as well as in a separate group of Tg mice during a 12-day treatment period, revealed no appreciable increases in brain temperature (and no/slight increases in body temperature) during EMF "ON" periods. Thus, the neuropathologic/cognitive benefits of EMF treatment occur without brain hyperthermia. Finally, regional cerebral blood flow in cerebral cortex was determined to be reduced in both Tg and normal mice after 2 months of EMF treatment, most probably through cerebrovascular constriction induced by freed/disaggregated Aß (Tg mice) and slight body hyperthermia during "ON" periods. These results demonstrate that long-term EMF treatment can provide general cognitive benefit to very old Alzheimer's Tg mice and normal mice, as well as reversal of advanced Aß neuropathology in Tg mice without brain heating. Results further underscore the potential for EMF treatment against AD.
Asunto(s)
Enfermedad de Alzheimer/radioterapia , Péptidos beta-Amiloides/metabolismo , Circulación Cerebrovascular/efectos de la radiación , Magnetoterapia/métodos , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Animales , Temperatura Corporal/efectos de la radiación , Cognición/efectos de la radiación , Modelos Animales de Enfermedad , Campos Electromagnéticos , Humanos , Aprendizaje por Laberinto/efectos de la radiación , Memoria/efectos de la radiación , Ratones , Ratones Transgénicos , Mitocondrias/efectos de la radiación , Desempeño Psicomotor/efectos de la radiaciónRESUMEN
Although both human epidemiologic and animal model studies have suggested that caffeine/coffee protects against Alzheimer's disease, direct human evidence for this premise has been lacking. In the present case-control study, two separate cohorts consisting of 124 total individuals (65-88 years old) were cognitively assessed and a blood sample taken for caffeine/biomarker analysis. Subjects were then monitored for cognitive status over the ensuing 2-4 year period to determine the extent to which initial plasma caffeine/biomarkers levels would be predictive of changes in cognitive status. Plasma caffeine levels at study onset were substantially lower (-51%) in mild cognitive impairment (MCI) subjects who later progressed to dementia (MCIâDEM) compared to levels in stable MCI subjects (MCIâMCI). Moreover, none of the MCIâDEM subjects had initial blood caffeine levels that were above a critical level of 1200 ng/ml, while half of stable MCIâMCI subjects had blood caffeine levels higher than that critical level. Thus, plasma caffeine levels greater than 1200 ng/ml (≈6 µM) in MCI subjects were associated with no conversion to dementia during the ensuing 2-4 year follow-up period. Among the 11 cytokines measured in plasma, three of them (GCSF, IL-10, and IL-6) were decreased in MCIâDEM subjects, but not in stable MCIâMCI subjects with high plasma caffeine levels. Coffee would appear to be the major or perhaps only source of caffeine for such stable MCI patients. This case-control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset, particularly for those who already have MCI.
Asunto(s)
Cafeína/sangre , Cognición/fisiología , Disfunción Cognitiva/sangre , Demencia/prevención & control , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/psicología , Estudios de Casos y Controles , Disfunción Cognitiva/psicología , Demencia/sangre , Demencia/psicología , Progresión de la Enfermedad , Femenino , Humanos , Estudios Longitudinales , Masculino , Pruebas Neuropsicológicas , Factores de RiesgoRESUMEN
Amyloid precursor protein (APP) proteolysis is essential for production of amyloid-ß (Aß) peptides that form ß-amyloid plaques in brains of Alzheimer disease (AD) patients. Recent focus has been directed toward a group of naturally occurring anti-amyloidogenic polyphenols known as flavonoids. We orally administered the flavonoid tannic acid (TA) to the transgenic PSAPP mouse model of cerebral amyloidosis (bearing mutant human APP and presenilin-1 transgenes) and evaluated cognitive function and AD-like pathology. Consumption of TA for 6 months prevented transgene-associated behavioral impairment including hyperactivity, decreased object recognition, and defective spatial reference memory, but did not alter nontransgenic mouse behavior. Accordingly, brain parenchymal and cerebral vascular ß-amyloid deposits and abundance of various Aß species including oligomers were mitigated in TA-treated PSAPP mice. These effects occurred with decreased cleavage of the ß-carboxyl-terminal APP fragment, lowered soluble APP-ß production, reduced ß-site APP cleaving enzyme 1 protein stability and activity, and attenuated neuroinflammation. As in vitro validation, we treated well characterized mutant human APP-overexpressing murine neuron-like cells with TA and found significantly reduced Aß production associated with less amyloidogenic APP proteolysis. Taken together, these results raise the possibility that dietary supplementation with TA may be prophylactic for AD by inhibiting ß-secretase activity and neuroinflammation and thereby mitigating AD pathology.
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Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/prevención & control , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Trastornos del Conocimiento/tratamiento farmacológico , Trastornos del Conocimiento/prevención & control , Taninos/farmacología , Enfermedad de Alzheimer/patología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Péptidos beta-Amiloides/genética , Péptidos beta-Amiloides/metabolismo , Animales , Ácido Aspártico Endopeptidasas/metabolismo , Línea Celular , Angiopatía Amiloide Cerebral/tratamiento farmacológico , Angiopatía Amiloide Cerebral/patología , Trastornos del Conocimiento/patología , Modelos Animales de Enfermedad , Encefalitis/tratamiento farmacológico , Encefalitis/patología , Femenino , Gliosis/tratamiento farmacológico , Gliosis/patología , Humanos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Transgénicos , Neuronas/citología , Neuronas/efectos de los fármacos , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/metabolismoRESUMEN
Caffeine intake has been associated with a lower incidence of Alzheimer's disease (AD) in humans. In AD mouse models, caffeine significantly decreases senile plaques and amyloid beta (Aß) levels while also protecting against or reversing cognitive impairment. To understand the mechanism(s) underlying the protective effects of caffeine against AD pathology, we investigated the effects of a two-week treatment with caffeine (3mg/day) in transgenic (APPswe) mice and non-transgenic (NT) mice on signaling factors involved in neuronal plasticity and survival. We evaluated cAMP-dependent protein kinase A (PKA), phospho-cyclic AMP response-element binding protein (phospho-CREB), and the pro-apoptotic protein kinases extracellular signal-regulated kinase 1/2 (phospho-ERK) and phospho-c-Jun N-terminal kinase 1 (phospho-JNK) in the striatum and frontal cortex of caffeine-treated mice. In the striatum, APPswe control mice exhibited a significant decrease in phospho-CREB, as well as significant increases in phospho-JNK and phospho-ERK in comparison to NT mice. Caffeine treatment stimulated PKA activity, increased phospho-CREB levels, and decreased phospho-JNK and phospho-ERK expression in the striatum of APPswe mice, all of which are thought to be beneficial changes for brain function. Even caffeine-treated NT mice exhibited some of these changes in striatum. In the frontal cortex, caffeine did not significantly increase phospho-CREB and PKA activity, but significantly reduced phospho-JNK and phospho-ERK expression in both APPswe and NT mice. These results suggest that caffeine shifts the balance between neurodegeneration and neuronal survival toward the stimulation of pro-survival cascades and inhibition of pro-apoptotic pathways in the striatum and/or cortex, which may contribute to its beneficial effects against AD.
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Enfermedad de Alzheimer/enzimología , Encéfalo/efectos de los fármacos , Cafeína/farmacología , Estimulantes del Sistema Nervioso Central/farmacología , MAP Quinasa Quinasa 4/metabolismo , Transducción de Señal/efectos de los fármacos , Enfermedad de Alzheimer/patología , Animales , Western Blotting , Encéfalo/enzimología , Encéfalo/patología , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Modelos Animales de Enfermedad , Activación Enzimática , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones TransgénicosRESUMEN
Mitochondrial dysfunction is a hallmark of Alzheimer's disease (AD) and is observed in mutant amyloid precursor protein (APP) transgenic mouse models of familial AD. Melatonin is a potent antioxidant, can prevent toxic aggregation of Alzheimer's beta-amyloid (Aß) peptide and, when taken long term, can protect against cognitive deficits in APP transgenic mice. To study the effects of melatonin on brain mitochondrial function in an AD model, APP/PS1 transgenic mice were treated for 1 month with melatonin. Analysis of isolated brain mitochondria from mice indicated that melatonin treatment decreased mitochondrial Aß levels by two- to fourfold in different brain regions. This was accompanied by a near complete restoration of mitochondrial respiratory rates, membrane potential, and ATP levels in isolated mitochondria from the hippocampus, cortex, or striatum. When isolated mitochondria from untreated young mice were given melatonin, a slight increase in respiratory rate was observed. No such effect was observed in mitochondria from aged mice. In APP-expressing neuroblastoma cells in culture, mitochondrial function was restored by melatonin or by the structurally related compounds indole-3-propionic acid or N(1)-acetyl-N(2)-formyl-5-methoxykynuramine. This restoration was partially blocked by melatonin receptor antagonists indicating melatonin receptor signaling is required for the full effect. Therefore, treatments that stimulate melatonin receptor signaling may be beneficial for restoring mitochondrial function in AD, and preservation of mitochondrial function may an important mechanism by which long term melatonin treatment delays cognitive dysfunction in AD mice.
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Enfermedad de Alzheimer/tratamiento farmacológico , Melatonina/farmacología , Mitocondrias/efectos de los fármacos , Receptores de Melatonina/metabolismo , Adenosina Trifosfato/metabolismo , Enfermedad de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Análisis de Varianza , Animales , Encéfalo/citología , Encéfalo/metabolismo , Fraccionamiento Celular , Línea Celular Tumoral , Indoles/farmacología , Kinuramina/análogos & derivados , Kinuramina/farmacología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mitocondrias/metabolismo , Neuroblastoma , Propionatos/farmacología , Especies Reactivas de Oxígeno/metabolismo , Estadísticas no ParamétricasRESUMEN
Retrospective and prospective epidemiologic studies suggest that enhanced coffee/caffeine intake during aging reduces risk of Alzheimer's disease (AD). Underscoring this premise, our studies in AD transgenic mice show that long-term caffeine administration protects against cognitive impairment and reduces brain amyloid-ß levels/deposition through suppression of both ß- and γ-secretase. Because coffee contains many constituents in addition to caffeine that may provide cognitive benefits against AD, we examined effects of caffeinated and decaffeinated coffee on plasma cytokines, comparing their effects to caffeine alone. In both AßPPsw+PS1 transgenic mice and non-transgenic littermates, acute i.p. treatment with caffeinated coffee greatly and specifically increased plasma levels of granulocyte-colony stimulating factor (GCSF), IL-10, and IL-6. Neither caffeine solution alone (which provided high plasma caffeine levels) or decaffeinated coffee provided this effect, indicating that caffeine synergized with some as yet unidentified component of coffee to selectively elevate these three plasma cytokines. The increase in GCSF is particularly important because long-term treatment with coffee (but not decaffeinated coffee) enhanced working memory in a fashion that was associated only with increased plasma GCSF levels among all cytokines. Since we have previously reported that long-term GCSF treatment enhances cognitive performance in AD mice through three possible mechanisms (e.g., recruitment of microglia from bone marrow, synaptogenesis, and neurogenesis), the same mechanisms could be complimentary to caffeine's established ability to suppress Aß production. We conclude that coffee may be the best source of caffeine to protect against AD because of a component in coffee that synergizes with caffeine to enhance plasma GCSF levels, resulting in multiple therapeutic actions against AD.
Asunto(s)
Cafeína/uso terapéutico , Trastornos del Conocimiento/sangre , Trastornos del Conocimiento/prevención & control , Factor Estimulante de Colonias de Granulocitos/sangre , Inhibidores de Fosfodiesterasa/uso terapéutico , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/sangre , Precursor de Proteína beta-Amiloide/genética , Análisis de Varianza , Animales , Cafeína/sangre , Café/metabolismo , Trastornos del Conocimiento/etiología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Humanos , Memoria a Corto Plazo/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación/genética , Pruebas Neuropsicológicas , Fragmentos de Péptidos/sangre , Presenilina-1/genética , Teofilina/sangre , Factores de TiempoRESUMEN
Alzheimer's disease (AD) affects millions of people world-wide and new effective and safe therapies are needed. Cotinine, the main metabolite of nicotine, has a long half-life and does not have cardiovascular or addictive side effects in humans. We studied the effect of cotinine on amyloid-ß (Aß) aggregation as well as addressed its impact on working and reference memories. Cotinine reduced Aß deposition, improved working and reference memories, and inhibited Aß oligomerization in the brains of transgenic (Tg) 6799 AD mice. In vitro studies confirmed the inhibitory effect of cotinine on Aß1-42 aggregation. Cotinine stimulated Akt signaling, including the inhibition of glycogen synthase kinase 3ß (GSK3ß), which promotes neuronal survival and the synaptic plasticity processes underlying learning and memory in the hippocampus and cortex of wild type and Tg6799 AD mice. Simulation of the cotinine-Aß1-42 complex using molecular dynamics showed that cotinine may interact with key histidine residues of Aß1-42, altering its structure and inhibiting its aggregation. The good safety profile in humans and its beneficial effects suggest that cotinine may be an excellent therapeutic candidate for the treatment of AD.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Péptidos beta-Amiloides/metabolismo , Cotinina/uso terapéutico , Modelos Animales de Enfermedad , Memoria/fisiología , Enfermedad de Alzheimer/tratamiento farmacológico , Animales , Cotinina/química , Cotinina/farmacología , Humanos , Masculino , Memoria/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Desempeño Psicomotor/efectos de los fármacos , Desempeño Psicomotor/fisiología , Distribución AleatoriaRESUMEN
Rheumatoid arthritis (RA) is a negative risk factor for the development of Alzheimer's disease (AD). While it has been commonly assumed that RA patients' usage of non-steroidal anti-inflammatory drugs (NSAIDs) helped prevent onset and progression of AD, NSAID clinical trials have proven unsuccessful in AD patients. To determine whether intrinsic factors within RA pathogenesis itself may underlie RA's protective effect, we investigated the activity of colony-stimulating factors, upregulated in RA, on the pathology and behavior of transgenic AD mice. 5 microg bolus injections of macrophage, granulocyte, and granulocyte-macrophage colony-stimulating factors (M-CSF, G-CSF, or GM-CSF) were administered unilaterally into the hippocampus of aged cognitively-impaired AD mice and the resulting amyloid load reductions determined one week later, using the artificial cerebrospinal fluid-injected contralateral sides as controls. G-CSF and more significantly, GM-CSF reduced amyloidosis throughout the treated brain hemisphere one week following bolus administration to AD mice. 20 daily subcutaneous injections of 5 microg of GM-CSF (the most amyloid-reducing CSF in the bolus experiment) were administered to balanced cohorts of AD mice after assessment in a battery of cognitive tests. Reductions in amyloid load and improvements in cognitive function were assessed. Subcutaneous GM-CSF administration significantly reduced brain amyloidosis and completely reversed the cognitive impairment, while increasing hippocampal synaptic area and microglial density. These findings, along with two decades of accrued safety data using Leukine, recombinant human GMCSF, in elderly leukopenic patients, suggest that Leukine should be tested as a treatment to reverse cerebral amyloid pathology and cognitive impairment in AD.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Amiloidosis/tratamiento farmacológico , Artritis Reumatoide/metabolismo , Trastornos del Conocimiento/tratamiento farmacológico , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Enfermedad de Alzheimer/epidemiología , Enfermedad de Alzheimer/patología , Amiloidosis/epidemiología , Amiloidosis/patología , Animales , Artritis Reumatoide/epidemiología , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/patología , Modelos Animales de Enfermedad , Factor Estimulante de Colonias de Granulocitos/farmacología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/patología , Humanos , Factor Estimulante de Colonias de Macrófagos/farmacología , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Factores de Riesgo , Regulación hacia Arriba/fisiologíaRESUMEN
Mitochondrial dysfunction is observed in Alzheimer's disease (AD) brain, and the amyloid-beta (Abeta) peptide is known to induce mitochondrial dysfunction. The relative degree of mitochondrial dysfunction in different regions of the brain in AD is not completely understood. Moreover, the relationship between levels of synaptic mitochondrial Abeta and mitochondrial dysfunction has not been clearly established. Therefore synaptic and nonsynaptic mitochondria were isolated from the hippocampus, cortex, striatum, and amygdala of 12 month AbetaPPsw and AbetaPP+PS1 mouse models of AD as well as nontransgenic mice. Mitochondrial respiratory rates, reactive oxygen species production, membrane potential, and cytochrome c oxidase activity were measured. Hippocampal and cortical mitochondria showed the highest levels of mitochondrial dysfunction, while striatal mitochondria were moderately affected, and amygdalar mitochondria were minimally affected. Mitochondria from AbetaPP/PS1 brain regions were more impaired than those from AbetaPP mice. Mitochondrial Abeta levels nearly mirrored the extent of mitochondrial dysfunction. Synaptic mitochondria were more impaired than nonsynaptic mitochondria in the AD mouse models. The AbetaPP/PS1 mice showed more impairment in the cognitive interference task of working memory than the AbetaPP mice. The association between mitochondrial Abeta levels and mitochondrial dysfunction in mouse models of AD supports a primary role for mitochondrial Abeta in AD pathology. Moreover, the degree of cognitive impairment in AD transgenic mice can be linked to the extent of synaptic mitochondrial dysfunction and mitochondrial Abeta levels, suggesting that a mitochondrial Abeta-induced signaling cascade may contribute to cognitive impairment. Therapeutics that target this cascade could be beneficial in the treatment of AD.
Asunto(s)
Enfermedad de Alzheimer/complicaciones , Péptidos beta-Amiloides/metabolismo , Encéfalo/patología , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/patología , Mitocondrias/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Precursor de Proteína beta-Amiloide/genética , Animales , Conducta Animal , Encéfalo/metabolismo , Calcio/metabolismo , Modelos Animales de Enfermedad , Complejo IV de Transporte de Electrones/metabolismo , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Aprendizaje por Laberinto/fisiología , Potencial de la Membrana Mitocondrial/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación/genética , Presenilina-1/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Epidemiologic studies have increasingly suggested that caffeine/coffee could be an effective therapeutic against Alzheimer's disease (AD). We have utilized a transgenic mouse model for AD in well-controlled studies to determine if caffeine and/or coffee have beneficial actions to protect against or reverse AD-like cognitive impairment and AD pathology. AD mice given caffeine in their drinking water from young adulthood into older age showed protection against memory impairment and lower brain levels of the abnormal protein (amyloid-beta; Abeta) thought to be central to AD pathogenesis. Moreover, "aged" cognitively-impaired AD mice exhibited memory restoration and lower brain Abeta levels following only 1-2 months of caffeine treatment. We believe that the cognitive benefits of chronic caffeine administration in AD mice are due to caffeine itself, and not metabolites of caffeine; this, because our long-term administration of theophylline to AD mice provided no cognitive benefits. In acute studies involving AD mice, one oral caffeine treatment quickly reduced both brain and plasma Abeta levels - similarly rapid alterations in plasma Abeta levels were seen in humans following acute caffeine administration. "Caffeinated" coffee provided to AD mice also quickly decreased plasma Abeta levels, but not "decaffeinated" coffee, suggesting that caffeine is critical to decreasing blood Abeta levels. Caffeine appears to provide its disease-modifying effects through multiple mechanisms, including a direct reduction of Abeta production through suppression of both beta- and gamma-secretase levels. These results indicate a surprising ability of moderate caffeine intake (the human equivalent of 500 mg caffeine or 5 cups of coffee per day) to protect against or treat AD in a mouse model for the disease and a therapeutic potential for caffeine against AD in humans.