Mitochondrial dysfunction has been proposed to play a pivotal role in neurodegenerative diseases, including Alzheimer's disease (AD). To address whether mitochondrial dysfunction precedes the development of AD pathology, we conducted mitochondrial functional analyses in female triple transgenic Alzheimer's mice (3xTg-AD) and age-matched nontransgenic (nonTg). Mitochondrial dysfunction in the 3xTg-AD brain was evidenced by decreased mitochondrial respiration and decreased pyruvate dehydrogenase (PDH) protein level and activity as early as 3 months of age. 3xTg-AD mice also exhibited increased oxidative stress as manifested by increased hydrogen peroxide production and lipid peroxidation. Mitochondrial amyloid beta (A) level in the 3xTg-AD mice was significantly increased at 9 months and temporally correlated with increased level of A binding to alcohol dehydrogenase (ABAD). Embryonic neurons derived from 3xTg-AD mouse hippocampus exhibited significantly decreased mitochondrial respiration and increased glycolysis. Results of these analyses indicate that compromised mitochondrial function is evident in embryonic hippocampal neurons, continues unabated in females throughout the reproductive period, and is exacerbated during reproductive senescence. In nontransgenic control mice, oxidative stress was coincident with reproductive senescence and accompanied by a significant decline in mitochondrial function. Reproductive senescence in the 3xTg-AD mouse brain markedly exacerbated mitochondrial dysfunction. Collectively, the data indicate significant mitochondrial dysfunction occurs early in AD pathogenesis in a female AD mouse model. Mitochondrial dysfunction provides a plausible mechanistic rationale for the hypometabolism in brain that precedes AD diagnosis and suggests therapeutic targets for prevention of AD.ABAD ͉ aging ͉ bioenergetics ͉ brain hypometabolism ͉ mitochondria T he essential role of mitochondria in cellular bioenergetics and survival has been well established (1-3). Previous studies have suggested that mitochondrial dysfunction plays a central role in the pathogenesis of neurodegenerative disorders, including Alzheimer's disease (AD) (1, 4). Alzheimer's pathology is accompanied by a decrease in expression and activity of enzymes involved in mitochondrial bioenergetics, which would be expected to lead to compromised electron transport chain complex activity and reduced ATP synthesis (5). Further, in AD there is a generalized shift from glycolytic energy production toward use of an alternative fuel, ketone bodies. This is evidenced by a 45% reduction in cerebral glucose utilization in AD patients (6), which is paralleled by decrease in the expression of glycolytic enzymes coupled to a decrease in the activity of the pyruvate dehydrogenase (PDH) complex (5). Patients with incipient AD exhibit a utilization ratio of 2:1 glucose to alternative fuel, whereas comparably aged controls exhibit a ratio of 29:1, whereas young controls exclusively use glucose as with a ratio of 100:0 ratio (7). In addition to t...
Emerging data indicate that progesterone has multiple non-reproductive functions in the central nervous system to regulate cognition, mood, inflammation, mitochondrial function, neurogenesis and regeneration, myelination and recovery from traumatic brain injury. Progesterone-regulated neural responses are mediated by an array of progesterone receptors (PR) that include the classic nuclear PRA and PRB receptors and splice variants of each, the seven transmembrane domain 7TMPRβ and the membrane-associated 25-Dx PR (PGRMC1). These PRs induce classic regulation of gene expression while also transducing signaling cascades that originate at the cell membrane and ultimately activate transcription factors. Remarkably, PRs are broadly expressed throughout the brain and can be detected in every neural cell type. The distribution of PRs beyond hypothalamic borders, suggests a much broader role of progesterone in regulating neural function. Despite the large body of evidence regarding progesterone regulation of reproductive behaviors and estrogen-inducible responses as well as effects of progesterone metabolite neurosteroids, much remains to be discovered regarding the functional outcomes resulting from activation of the complex array of PRs in brain by gonadally and / or glial derived progesterone. Moreover, the impact of clinically used progestogens and developing selective PR modulators for targeted outcomes in brain is a critical avenue of investigation as the non-reproductive functions of PRs have far-reaching implications for hormone therapy to maintain neurological health and function throughout menopausal aging.
We show that fibroblast growth factor 2 (FGF2) and FGF receptors are transiently expressed by cells of the pseudostratified ventricular epithelium (PVE) during early neurogenesis. A single microinjection of FGF2 into cerebral ventricles of rat embryos at E15.5 increased the volume and total number of neurons in the adult cerebral cortex by 18% and 87%, respectively. Microinjection of FGF2 by the end of neurogenesis, at E20.5, selectively increased the number of glia. Mice lacking the FGF2 gene had fewer cortical neurons and glia at maturity. BrdU studies in FGF2-microinjected and FGF2-null animals suggested that FGF2 increases the proportion of dividing cells in the PVE without affecting the cell-cycle length. Thus, FGF2 increases the number of rounds of division of cortical progenitors.
ObjectiveTo determine the effect of erenumab, a human anti-calcitonin gene-related peptide receptor monoclonal antibody, in patients with chronic migraine and medication overuse.MethodsIn this double-blind, placebo-controlled study, 667 adults with chronic migraine were randomized (3:2:2) to placebo or erenumab (70 or 140 mg), stratified by region and medication overuse status. Data from patients with baseline medication overuse at baseline were used to assess changes in monthly migraine days, acute migraine-specific medication treatment days, and proportion of patients achieving ≥50% reduction from baseline in monthly migraine days.ResultsOf 667 patients randomized, 41% (n = 274) met medication overuse criteria. In the medication overuse subgroup, erenumab 70 or 140 mg groups had greater reductions than the placebo group at month 3 in monthly migraine days (mean [95% confidence interval] −6.6 [−8.0 to −5.3] and −6.6 [−8.0 to −5.3] vs −3.5 [−4.6 to −2.4]) and acute migraine-specific medication treatment days (−5.4 [−6.5 to −4.4] and −4.9 [−6.0 to −3.8] vs −2.1 [−3.0 to −1.2]). In the placebo and 70 and 140 mg groups, ≥50% reductions in monthly migraine days were achieved by 18%, 36% (odds ratio [95% confidence interval] 2.67 [1.36–5.22]) and 35% (odds ratio 2.51 [1.28–4.94]). These clinical responses paralleled improvements in patient-reported outcomes with a consistent benefit of erenumab across multiple measures of impact, disability, and health-related quality of life. The observed treatment effects were similar in the non–medication overuse subgroup.ConclusionsErenumab reduced migraine frequency and acute migraine-specific medication treatment days in patients with chronic migraine and medication overuse, improving disability and quality of life.Clinicaltrials.gov identifierNCT02066415.Classification of evidenceThis study provides Class II evidence that erenumab reduces monthly migraine days at 3 months in patients with chronic migraine and medication overuse.
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