Background: Many aging changes seem similar to those elicited by sleep-deprivation and psychosoci... more Background: Many aging changes seem similar to those elicited by sleep-deprivation and psychosocial stress. Further, sleep architecture changes with age suggest an age-related loss of sleep. Here, we hypothesized that sleep deprivation in young subjects would elicit both stress and aging-like transcriptional responses. Methodology/Principal Findings: F344 rats were divided into control and sleep deprivation groups. Body weight, adrenal weight, corticosterone level and hippocampal CA1 transcriptional profiles were measured. A second group of animals was exposed to novel environment stress (NES), and their hippocampal transcriptional profiles measured. A third cohort exposed to control or SD was used to validate transcriptional results with Western blots. Microarray results were statistically contrasted with prior transcriptional studies. Microarray results pointed to sleep pressure signaling and macromolecular synthesis disruptions in the hippocampal CA1 region. Animals exposed to NES recapitulated nearly one third of the SD transcriptional profile. However, the SD-aging relationship was more complex. Compared to aging, SD profiles influenced a significant subset of genes. mRNA associated with neurogenesis and energy pathways showed agreement between aging and SD, while immune, glial, and macromolecular synthesis pathways showed SD profiles that opposed those seen in aging. Conclusions/Significance: We conclude that although NES and SD exert similar transcriptional changes, selective presynaptic release machinery and Homer1 expression changes are seen in SD. Among other changes, the marked decrease in Homer1 expression with age may represent an important divergence between young and aged brain response to SD. Based on this, it seems reasonable to conclude that therapeutic strategies designed to promote sleep in young subjects may have off-target effects in the aged. Finally, this work identifies presynaptic vesicular release and intercellular adhesion molecular signatures as novel therapeutic targets to counter effects of SD in young subjects.
It has been recognized for some time that the Ca 2+-dependent slow afterhyperpolarization (sAHP) ... more It has been recognized for some time that the Ca 2+-dependent slow afterhyperpolarization (sAHP) is larger in hippocampal neurons of aged compared with young animals. In addition, extensive studies since have shown that other Ca 2+-mediated electrophysiological responses are increased in hippocampus with aging, including Ca 2+ transients, L-type voltage-gated Ca 2+ channel activity, Ca 2+ spike duration and action potential accommodation. Elevated Ca 2+-induced Ca 2+ release from ryanodine receptors (RyRs) appears to drive amplification of the Ca 2+ responses. Components of this Ca 2+ dysregulation phenotype correlate with deficits in cognitive function and plasticity, indicating they may play critical roles in aging-related impairment of brain function. However, the molecular mechanisms underlying aging-related Ca 2+ dysregulation are not well understood. FK506-binding proteins 1a and 1b (FKBP1a/1b, also known as FKBP12/12.6) are immunophilin proteins that bind the immunosuppressant drugs FK506 and rapamycin. In muscle cells, FKBP1a/1b also bind RyRs and inhibits Ca 2+-induced Ca 2+ release, but it is not clear whether FKBPs act similarly in brain cells. Recently, we found that selectively disrupting hippocampal FKBP1b function in young rats, either by microinjecting adeno-associated viral vectors containing siRNA, or by treatment with rapamycin, increases the sAHP and recapitulates much of the hippocampal Ca 2+ dysregulation phenotype. Moreover, in microarray studies, we found FKBP1b gene expression was downregulated in hippocampus of aging rats and early-stage Alzheimer's disease subjects. These results suggest the novel hypothesis that declining FKBP function is a key factor in aging-related Ca 2+ dysregulation in the brain and point to potential new therapeutic targets for counteracting unhealthy brain aging.
The subject technology relates, in part, to a method of treating Alzheimer\u27s Disease (AD), ear... more The subject technology relates, in part, to a method of treating Alzheimer\u27s Disease (AD), early-stage AD, elevated risk of AD, mild cognitive impairment (MCI), or other forms of age-related cognitive decline in a subject in need thereof by administering to the subject a molecule that promotes calcium-release stabilization in ryanodine receptors (RyRs) and/or inosital triphosphate receptors (InsP3Rs) in brain cells. Diagnostic methods using calcium-release stabilizing immunophilins, junctophilins or calmodulin are also disclosed
Brain Ca(2+) regulatory processes are altered during aging, disrupting neuronal, and cognitive fu... more Brain Ca(2+) regulatory processes are altered during aging, disrupting neuronal, and cognitive functions. In hippocampal pyramidal neurons, the Ca(2+)-dependent slow afterhyperpolarization (sAHP) exhibits an increase with aging, which correlates with memory impairment. The increased sAHP results from elevated L-type Ca(2+) channel activity and ryanodine receptor (RyR)-mediated Ca(2+) release, but underlying molecular mechanisms are poorly understood. Previously, we found that expression of the gene encoding FK506-binding protein 12.6/1b (FKBP1b), a small immunophilin that stabilizes RyR-mediated Ca(2+) release in cardiomyocytes, declines in hippocampus of aged rats and Alzheimer\u27s disease subjects. Additionally, knockdown/disruption of hippocampal FKBP1b in young rats augments neuronal Ca(2+) responses. Here, we test the hypothesis that declining FKBP1b underlies aging-related hippocampal Ca(2+) dysregulation. Using microinjection of adeno-associated viral vector bearing a transg...
The subject technology relates, in part, to a method of treating Alzheimer's Disease (AD), early-... more The subject technology relates, in part, to a method of treating Alzheimer's Disease (AD), early-stage AD, elevated risk of AD, mild cognitive impairment (MCI), or other forms of age-related cognitive decline in a subject in need thereof by administering to the subject a molecule that promotes calcium-release stabilization in ryanodine receptors (RyRs) and/or inosital triphosphate receptors (InsP3Rs) in brain cells. Diagnostic methods using calcium-release stabilizing immunophilins, junctophilins or calmodulin are also disclosed. 10 Claims, 4 Drawing Sheets US 9,464,322 B2 Page 2 (56) References Cited OTHER PUBLICATIONS Skolnick eta!. "From genes to protein structure and function: novel applications of computational approaches in the genomic era."
subleqto any dlsclalmeri the term Ofthls Liau et al., "Identi?cation of a Human Glioma-associated... more subleqto any dlsclalmeri the term Ofthls Liau et al., "Identi?cation of a Human Glioma-associated Growth patent 1S eXIended 01' adjusted under 35 Factor Gene, Granulin, Using Differential Immuno-absorption", U.S.C. 154(b) by 0 days.
The subject technology relates, in part, to a method of treating Alzheimer's Disease (AD), early-... more The subject technology relates, in part, to a method of treating Alzheimer's Disease (AD), early-stage AD, elevated risk of AD, mild cognitive impairment (MCI), or other forms of age-related cognitive decline in a subject in need thereof by administering to the subject a molecule that promotes calcium-release stabilization in ryanodine receptors (RyRs) and/or inosital triphosphate receptors (InsP3Rs) in brain cells. Diagnostic methods using calcium-release stabilizing immunophilins, junctophilins or calmodulin are also disclosed. 10 Claims, 4 Drawing Sheets US 9,464,322 B2 Page 2 (56) References Cited OTHER PUBLICATIONS Skolnick eta!. "From genes to protein structure and function: novel applications of computational approaches in the genomic era."
RNA integrity numbers (RINs) are a standardized method for semi-quantification of RNA degradation... more RNA integrity numbers (RINs) are a standardized method for semi-quantification of RNA degradation, and are used in quality control prior to transcriptional profiling analysis. Recent work has demonstrated that RINs are associated with downstream transcriptional profiling, and correction procedures are typically employed in bioinformatic analysis pipelines to attempt to control for RIN’s influence on gene expression. However, relatively little work has been done to determine whether RIN’s influence is random, or is specifically targeted to a subset of mRNAs. We tested the hypothesis that RIN would be associated with a robust transcriptional profile seen across multiple studies.To test this, we downloaded subsets of raw transcriptional data from six published studies. We only included control, non-pathological post-mortem human brain tissue (n = 383 samples) in which independent subjects’ RIN values were also reported. A robust set of mRNAs consistently and significantly correlated wi...
Men and women differ in circulating lipids and coronary artery disease (CAD). While sex hormones ... more Men and women differ in circulating lipids and coronary artery disease (CAD). While sex hormones such as estrogens decrease CAD risk, hormone replacement therapy increases risk. Biological sex is determined by sex hormones and chromosomes, but effects of sex chromosomes on circulating lipids and atherosclerosis are unknown. Here, we use mouse models to separate effects of sex chromosomes and hormones on atherosclerosis, circulating lipids and intestinal fat metabolism. We assess atherosclerosis in multiple models and experimental paradigms that distinguish effects of sex chromosomes, and male or female gonads. Pro-atherogenic lipids and atherosclerosis are greater in XX than XY mice, indicating a primary effect of sex chromosomes. Small intestine expression of enzymes involved in lipid absorption and chylomicron assembly are greater in XX male and female mice with higher intestinal lipids. Together, our results show that an XX sex chromosome complement promotes the bioavailability o...
Intranasal insulin is a safe and effective method for ameliorating memory deficits associated wit... more Intranasal insulin is a safe and effective method for ameliorating memory deficits associated with pathological brain aging. However, the impact of different formulations and the duration of treatment on insulin’s efficacy and the cellular processes targeted by the treatment remain unclear. Here, we tested whether intranasal insulin aspart, a short-acting insulin formulation, could alleviate memory decline associated with aging and whether long-term treatment affected regulation of insulin receptors and other potential targets. Outcome variables included measures of spatial learning and memory, autoradiography and immunohistochemistry of the insulin receptor, and hippocampal microarray analyses. Aged Fischer 344 rats receiving long-term (3 months) intranasal insulin did not show significant memory enhancement on the Morris water maze task. Autoradiography results showed that long-term treatment reduced insulin binding in the thalamus but not the hippocampus. Results from hippocampal...
Aging is the leading risk factor for idiopathic Alzheimer's disease (AD), indicating that normal ... more Aging is the leading risk factor for idiopathic Alzheimer's disease (AD), indicating that normal aging processes promote AD and likely are present in the neurons in which AD pathogenesis originates. In AD, neurofibrillary tangles (NFTs) appear first in entorhinal cortex, implying that aging processes in entorhinal neurons promote NFT pathogenesis. Using electrophysiology and immunohistochemistry, we find pronounced aging-related Ca 2+ dysregulation in rat entorhinal neurons homologous with the human neurons in which NFTs originate. Considering that humans recapitulate many aspects of animal brain aging, these results support the hypothesis that aging-related Ca 2+ dysregulation occurs in human entorhinal neurons and promotes NFT pathogenesis.
Arteriosclerosis, thrombosis, and vascular biology, 2018
Aortic pathologies exhibit sexual dimorphism, with aneurysms in both the thoracic and abdominal a... more Aortic pathologies exhibit sexual dimorphism, with aneurysms in both the thoracic and abdominal aorta (ie, abdominal aortic aneurysm [AAA]) exhibiting higher male prevalence. Women have lower prevalence of aneurysms, but when they occur, aneurysms progress rapidly. To define mechanisms for these sex differences, we determined the role of sex chromosome complement and testosterone on the location and progression of angiotensin II (AngII)-induced aortic pathologies. We used transgenic male mice expressing (sex-determining region Y) on an autosome to create (low-density lipoprotein receptor)-deficient male mice with an XY or XX sex chromosome complement. Transcriptional profiling was performed on abdominal aortas from XY or XX males, demonstrating 1746 genes influenced by sex chromosomes or sex hormones. Males (XY or XX) were either sham-operated or orchiectomized before AngII infusions. Diffuse aortic aneurysm pathology developed in XY AngII-infused males, whereas XX males developed f...
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 24, 2018
Hippocampal overexpression of FK506-binding protein 12.6/1b (), a negative regulator of ryanodine... more Hippocampal overexpression of FK506-binding protein 12.6/1b (), a negative regulator of ryanodine receptor Carelease, reverses aging-induced memory impairment and neuronal Cadysregulation. Here, we tested the hypothesis thatalso can protect downstream transcriptional networks from aging-induced dysregulation. We gave hippocampal microinjections of-expressing viral vector to male rats at either 13 months of age (long-term, LT) or 19 months of age (short-term, ST) and tested memory performance in the Morris water maze at 21 months of age. Aged rats treated ST or LT withsubstantially outperformed age-matched vector controls and performed similarly to each other and young controls (YCs). Transcriptional profiling in the same animals identified 2342 genes with hippocampal expression that was upregulated/downregulated in aged controls (ACs) compared with YCs (the aging effect). Of these aging-dependent genes, 876 (37%) also showed altered expression in aged-treated rats compared with ACs,...
Background: Abdominal aortic aneurysms (AAAs) are a deadly pathology with strong sexual dimorphis... more Background: Abdominal aortic aneurysms (AAAs) are a deadly pathology with strong sexual dimorphism. Similar to humans, female mice exhibit far lower incidences of angiotensin II–induced AAAs than males. In addition to sex hormones, the X and Y sex chromosomes, and their unique complements of genes, may contribute to sexually dimorphic AAA pathology. Here, we defined the effect of female (XX) versus male (XY) sex chromosome complement on angiotensin II–induced AAA formation and rupture in phenotypically female mice. Methods: Female low-density lipoprotein receptor ( Ldlr ) deficient mice with an XX or XY sex chromosome complement were infused with angiotensin II for 28 days to induce AAAs. Abdominal aortic lumen diameters were quantified by ultrasound, whereas AAA diameters were quantified at study end point. DNA microarrays were performed on abdominal aortas. To mimic males, female mice were administered a single dose of testosterone as neonates or as adults before angiotensin II in...
subleqto any dlsclalmeri the term Ofthls Liau et al., "Identi?cation of a Human Glioma-associated... more subleqto any dlsclalmeri the term Ofthls Liau et al., "Identi?cation of a Human Glioma-associated Growth patent 1S eXIended 01' adjusted under 35 Factor Gene, Granulin, Using Differential Immuno-absorption", U.S.C. 154(b) by 0 days.
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 29, 2015
Brain Ca(2+) regulatory processes are altered during aging, disrupting neuronal, and cognitive fu... more Brain Ca(2+) regulatory processes are altered during aging, disrupting neuronal, and cognitive functions. In hippocampal pyramidal neurons, the Ca(2+)-dependent slow afterhyperpolarization (sAHP) exhibits an increase with aging, which correlates with memory impairment. The increased sAHP results from elevated L-type Ca(2+) channel activity and ryanodine receptor (RyR)-mediated Ca(2+) release, but underlying molecular mechanisms are poorly understood. Previously, we found that expression of the gene encoding FK506-binding protein 12.6/1b (FKBP1b), a small immunophilin that stabilizes RyR-mediated Ca(2+) release in cardiomyocytes, declines in hippocampus of aged rats and Alzheimer's disease subjects. Additionally, knockdown/disruption of hippocampal FKBP1b in young rats augments neuronal Ca(2+) responses. Here, we test the hypothesis that declining FKBP1b underlies aging-related hippocampal Ca(2+) dysregulation. Using microinjection of adeno-associated viral vector bearing a trans...
Astrocyte reactivity (i.e., activation) and associated neuroinflammation are increasingly thought... more Astrocyte reactivity (i.e., activation) and associated neuroinflammation are increasingly thought to contribute to neurodegenerative disease. However, the mechanisms that trigger astrocyte activation are poorly understood. Here, we studied the Ca2+-dependent phosphatase calcineurin, which regulates inflammatory signaling pathways in immune cells, for a role in astrogliosis and brain neuroinflammation. Adenoviral transfer of activated calcineurin to primary rat hippocampal cultures resulted in pronounced thickening of astrocyte somata and processes compared with uninfected or virus control cultures, closely mimicking the activated hypertrophic phenotype. This effect was blocked by the calcineurin inhibitor cyclosporin A. Parallel microarray studies, validated by extensive statistical analyses, showed that calcineurin overexpression also induced genes and cellular pathways representing most major markers associated with astrocyte activation and recapitulated numerous changes in gene e...
With aging, multiple Ca2+-associated electrophysiological processes exhibit increased magnitude i... more With aging, multiple Ca2+-associated electrophysiological processes exhibit increased magnitude in hippocampal pyramidal neurons, including the Ca2+-dependent slow afterhyperpolarization (sAHP), L-type voltage-gated Ca2+channel (L-VGCC) activity, Ca2+-induced Ca2+release (CICR) from ryanodine receptors (RyRs), and Ca2+transients. This pattern of Ca2+dysregulation correlates with reduced neuronal excitability/plasticity and impaired learning/memory and has been proposed to contribute to unhealthy brain aging and Alzheimer's disease. However, little is known about the underlying molecular mechanisms. In cardiomyocytes, FK506-binding protein 1b/12.6 (FKBP1b) binds and stabilizes RyR2 in the closed state, inhibiting RyR-mediated Ca2+release. Moreover, we recently found that hippocampalFkbp1bexpression is downregulated, whereasRyr2andFrap1/Mtor(mammalian target of rapamycin) expression is upregulated with aging in rats. Here, we tested the hypothesis that disrupting FKBP1b function a...
Although expression of some genes is known to change during neuronal activity or plasticity, the ... more Although expression of some genes is known to change during neuronal activity or plasticity, the overall relationship of gene expression changes to memory or memory disorders is not well understood. Here, we combined extensive statistical microarray analyses with behavioral testing to comprehensively identify genes and pathways associated with aging and cognitive dysfunction. Aged rats were separated into cognitively unimpaired (AU) or impaired (AI) groups based on their Morris water maze performance relative to young-adult (Y) animals. Hippocampal gene expression was assessed in Y, AU, and AI on the fifth (last) day of maze training (5T) or 21 d posttraining (21PT) and in nontrained animals (eight groups total, one array per animal;n= 78 arrays). ANOVA and linear contrasts identified genes that differed from Y generally with aging (differed in both AU and AI) or selectively, with cognitive status (differed only in AI or AU). Altered pathways/processes were identified by overreprese...
Age-dependent metabolic syndrome (MetS) is a well established risk factor for cardiovascular dise... more Age-dependent metabolic syndrome (MetS) is a well established risk factor for cardiovascular disease, but it also confers major risk for impaired cognition in normal aging or Alzheimer's disease (AD). However, little is known about the specific pathways mediating MetS–brain interactions. Here, we performed the first studies quantitatively linking MetS variables to aging changes in brain genome-wide expression and mitochondrial function. In six young adult and six aging female rhesus monkeys, we analyzed gene expression in two major hippocampal subdivisions critical for memory/cognitive function [hippocampus proper, or cornu ammonis (CA), and dentate gyrus (DG)]. Genes that changed with aging [aging-related genes (ARGs)] were identified in each region. Serum variables reflecting insulin resistance and dyslipidemia were used to construct a quantitative MetS index (MSI). This MSI increased with age and correlated negatively with hippocampal mitochondrial function (state III oxidati...
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Papers by Eric Blalock