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1.
Int J Mol Sci ; 23(7)2022 Mar 26.
Article in English | MEDLINE | ID: mdl-35409014

ABSTRACT

Herbal remedies are increasing in popularity as treatments for metabolic conditions such as obesity and Type 2 Diabetes. One potential therapeutic option is fenugreek seeds (Trigonella foenum-graecum), which have been used for treating high cholesterol and Type 2 diabetes. A proposed mechanism for these benefits is through alterations in the microbiome, which impact mammalian host metabolic function. This study used untargeted metabolomics to investigate the fenugreek-induced alterations in the intestinal, liver, and serum profiles of mice fed either a 60% high-fat or low-fat control diet each with or without fenugreek supplementation (2% w/w) for 14 weeks. Metagenomic analyses of intestinal contents found significant alterations in the relative composition of the gut microbiome resulting from fenugreek supplementation. Specifically, Verrucomicrobia, a phylum containing beneficial bacteria which are correlated with health benefits, increased in relative abundance with fenugreek. Metabolomics partial least squares discriminant analysis revealed substantial fenugreek-induced changes in the large intestines. However, it was observed that while the magnitude of changes was less, significant modifications were present in the liver tissues resulting from fenugreek supplementation. Further analyses revealed metabolic processes affected by fenugreek and showed broad ranging impacts in multiple pathways, including carnitine biosynthesis, cholesterol and bile acid metabolism, and arginine biosynthesis. These pathways may play important roles in the beneficial effects of fenugreek.


Subject(s)
Diabetes Mellitus, Type 2 , Gastrointestinal Microbiome , Trigonella , Animals , Cholesterol , Diabetes Mellitus, Type 2/drug therapy , Dietary Supplements , Mammals , Mice , Plant Extracts/pharmacology , Plant Extracts/therapeutic use
2.
Sci Rep ; 10(1): 1245, 2020 01 27.
Article in English | MEDLINE | ID: mdl-31988303

ABSTRACT

Fenugreek (Trigonella foenum-graecum) is an annual herbaceous plant and a staple of traditional health remedies for metabolic conditions including high cholesterol and diabetes. While the mechanisms of the beneficial actions of fenugreek remain unknown, a role for intestinal microbiota in metabolic homeostasis is likely. To determine if fenugreek utilizes intestinal bacteria to offset the adverse effects of high fat diets, C57BL/6J mice were fed control/low fat (CD) or high fat (HFD) diets each supplemented with or without 2% (w/w) fenugreek for 16 weeks. The effects of fenugreek and HFD on gut microbiota were comprehensively mapped and then statistically assessed in relation to effects on metrics of body weight, hyperlipidemia, and glucose tolerance. 16S metagenomic analyses revealed robust and significant effects of fenugreek on gut microbiota, with alterations in both alpha and beta diversity as well as taxonomic redistribution under both CD and HFD conditions. As previously reported, fenugreek attenuated HFD-induced hyperlipidemia and stabilized glucose tolerance without affecting body weight. Finally, fenugreek specifically reversed the dysbiotic effects of HFD on numerous taxa in a manner tightly correlated with overall metabolic function. Collectively, these data reinforce the essential link between gut microbiota and metabolic syndrome and suggest that the preservation of healthy populations of gut microbiota participates in the beneficial properties of fenugreek in the context of modern Western-style diets.


Subject(s)
Diet, High-Fat/adverse effects , Gastrointestinal Microbiome/drug effects , Plant Extracts/pharmacology , Animals , Bacteria/genetics , Blood Glucose , Body Weight/drug effects , Dietary Supplements , Disease Models, Animal , Dyslipidemias/prevention & control , Glucose/metabolism , Glucose Intolerance/prevention & control , Hyperlipidemias/drug therapy , Male , Mice , Mice, Inbred C57BL , Obesity/drug therapy , Obesity/microbiology , Plant Extracts/metabolism , RNA, Ribosomal, 16S/genetics , Trigonella/metabolism
3.
Biochim Biophys Acta Mol Basis Dis ; 1865(9): 2157-2167, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31034991

ABSTRACT

Alzheimer's disease (AD) is the most common age-related neurodegenerative disease, while obesity is a major global public health problem associated with the metabolic disorder type 2 diabetes mellitus (T2DM). Chronic obesity and T2DM have been identified as invariant risk factors for dementia and late-onset AD, while their impacts on the occurrence and development of AD remain unclear. As shown in our previous study, the diabetic mutation (db, Leprdb/db) induces mixed or vascular dementia in mature to middle-aged APPΔNL/ΔNL x PS1P264L/P264L knock-in mice (db/AD). In the present study, the impacts of the db mutation on young AD mice at 10 weeks of age were evaluated. The db mutation not only conferred young AD mice with severe obesity, impaired glucose regulation and activated mammalian target of rapamycin (mTOR) signaling pathway in the mouse cortex, but lead to a surprising improvement in memory. At this young age, mice also had decreased cerebral Aß content, which we have not observed at older ages. This was unlikely to be related to altered Aß synthesis, as both ß- and γ-secretase were unchanged. The db mutation also reduced the cortical IL-1ß mRNA level and IBA1 protein level in young AD mice, with no significant effect on the activation of microglia and astrocytes. We conclude that the db mutation could transitorily improve the memory of young AD mice, a finding that may be partially explained by the relatively improved glucose homeostasis in the brains of db/AD mice compared to their counterpart AD mice, suggesting that glucose regulation could be a strategy for prevention and treatment of neurodegenerative diseases like AD.


Subject(s)
Alzheimer Disease/pathology , Diabetes Mellitus, Type 2/mortality , Memory , Receptors, Leptin/genetics , Aging , Alzheimer Disease/metabolism , Amyloid Precursor Protein Secretases/metabolism , Amyloid beta-Peptides/metabolism , Animals , Behavior, Animal , Brain/metabolism , Brain/pathology , Calcium-Binding Proteins/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/pathology , Disease Models, Animal , Glial Fibrillary Acidic Protein/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microfilament Proteins/metabolism , Receptors, Leptin/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/metabolism
4.
J Neurosci ; 38(44): 9414-9422, 2018 10 31.
Article in English | MEDLINE | ID: mdl-30381433

ABSTRACT

The gut microbiota has emerged as a critical player in shaping and modulating brain function and has been shown to influence numerous behaviors, including anxiety and depression-like behaviors, sociability, and cognition. However, the effects of the gut microbiota on specific disorders associated with thalamo-cortico-basal ganglia circuits, ranging from compulsive behavior and addiction to altered sensation and motor output, are only recently being explored. Wholesale depletion and alteration of gut microbial communities in rodent models of disorders, such as Parkinson's disease, autism, and addiction, robustly affect movement and motivated behavior. A new frontier therefore lies in identifying specific microbial alterations that affect these behaviors and understanding the underlying mechanisms of action. Comparing alterations in gut microbiota across multiple basal-ganglia associated disease states allows for identification of common mechanistic pathways that may interact with distinct environmental and genetic risk factors to produce disease-specific outcomes.


Subject(s)
Brain/physiopathology , Dysbiosis/physiopathology , Gastrointestinal Microbiome/physiology , Mental Disorders/physiopathology , Motivation/physiology , Movement/physiology , Animals , Dysbiosis/diagnosis , Dysbiosis/psychology , Humans , Mental Disorders/diagnosis , Mental Disorders/psychology
5.
Biol Psychiatry ; 83(3): 214-223, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29031410

ABSTRACT

There has been an explosion of interest in the study of microorganisms inhabiting the gastrointestinal tract (gut microbiota) and their impact on host health and physiology. Accumulating data suggest that altered communication between gut microbiota and host systems could participate in disorders such as obesity, diabetes mellitus, and autoimmune disorders as well as neuropsychiatric disorders, including autism, anxiety, and major depressive disorders. The conceptual development of the microbiome-gut-brain axis has facilitated understanding of the complex and bidirectional networks between gastrointestinal microbiota and their host, highlighting potential mechanisms through which this environment influences central nervous system physiology. Communication pathways between gut microbiota and the central nervous system could include autonomic, neuroendocrine, enteric, and immune systems, with pathology resulting in disruption to neurotransmitter balance, increases in chronic inflammation, or exacerbated hypothalamic-pituitary-adrenal axis activity. However, uncertainty remains regarding the generalizability of controlled animal studies to the more multifaceted pattern of human pathophysiology, especially with regard to the therapeutic potential for neuropsychiatric health. This narrative review summarizes current understanding of gut microbial influence over physiological function, with an emphasis on neurobehavioral and neurological impairment based on growing understanding of the gut-brain axis. Experimental and clinical data regarding means of therapeutic manipulation of gut microbiota as a novel treatment option for mental health are described, and important knowledge gaps are identified and discussed.


Subject(s)
Brain , Gastrointestinal Microbiome/physiology , Mental Disorders , Animals , Brain/immunology , Brain/metabolism , Brain/physiopathology , Gastrointestinal Microbiome/immunology , Humans , Mental Disorders/immunology , Mental Disorders/metabolism , Mental Disorders/physiopathology , Mental Disorders/therapy
6.
J Clin Exp Neuropsychol ; 40(3): 292-302, 2018 04.
Article in English | MEDLINE | ID: mdl-28669314

ABSTRACT

BACKGROUND: Clarifying relationships between specific neurocognitive functions in cognitively intact older adults can improve our understanding of mechanisms involved in cognitive decline, which may allow identification of new opportunities for intervention and earlier detection of those at increased risk of dementia. METHOD: The present study employed latent growth curve modeling to longitudinally examine the relationship between executive attention/processing speed, episodic memory, language, and working memory functioning utilizing the neuropsychological test battery from the National Alzheimer's Disease Coordinating Center. A total of 691 relatively healthy older adults (Mage = 69.07, SD = 6.49) were assessed at baseline, and 553 individuals completed three visits spanning a two-year period. RESULTS: Better cognitive performance was concomitantly associated with better functioning across domains. Subtle declines in executive attention/processing speed processes were found, while, on average, memory and language performance improved with repeated testing. Lower executive attention/processing speed performance at baseline predicted less incremental growth rate in memory. In turn, higher initial memory functioning was associated with incremental improvements in language performance. CONCLUSIONS: These results are consistent with the notion that intact executive function and attention processes are important to preserving memory functioning with advanced age, but are also the functions most susceptible to decline with age. These findings also provide further insight into the critical role of practice effects in clinical assessment practice and have implications for pharmaceutical trials. Practice effects should be routinely considered as they may give the appearance of retention of function within the cognitive domains considered to be a hallmark of Alzheimer's disease pathology.


Subject(s)
Alzheimer Disease/diagnosis , Attention/physiology , Cognition/physiology , Cognitive Dysfunction/diagnosis , Executive Function/physiology , Language , Aged , Alzheimer Disease/psychology , Cognition Disorders/etiology , Cognitive Dysfunction/psychology , Early Diagnosis , Female , Humans , Male , Memory, Short-Term/physiology , Middle Aged , Neuropsychological Tests
7.
PLoS One ; 12(8): e0181500, 2017.
Article in English | MEDLINE | ID: mdl-28771483

ABSTRACT

High fat diet-induced obesity is associated with inflammatory and oxidative signaling in macrophages that likely participates in metabolic and physiologic impairment. One key factor that could drive pathologic changes in macrophages is the pro-inflammatory, pro-oxidant enzyme NADPH oxidase. However, NADPH oxidase is a pleiotropic enzyme with both pathologic and physiologic functions, ruling out indiscriminant NADPH oxidase inhibition as a viable therapy. To determine if targeted inhibition of monocyte/macrophage NADPH oxidase could mitigate obesity pathology, we generated mice that lack the NADPH oxidase catalytic subunit NOX2 in myeloid lineage cells. C57Bl/6 control (NOX2-FL) and myeloid-deficient NOX2 (mNOX2-KO) mice were given high fat diet for 16 weeks, and subject to comprehensive metabolic, behavioral, and biochemical analyses. Data show that mNOX2-KO mice had lower body weight, delayed adiposity, attenuated visceral inflammation, and decreased macrophage infiltration and cell injury in visceral adipose relative to control NOX2-FL mice. Moreover, the effects of high fat diet on glucose regulation and circulating lipids were attenuated in mNOX2-KO mice. Finally, memory was impaired and markers of brain injury increased in NOX2-FL, but not mNOX2-KO mice. Collectively, these data indicate that NOX2 signaling in macrophages participates in the pathogenesis of obesity, and reinforce a key role for macrophage inflammation in diet-induced metabolic and neurologic decline. Development of macrophage/immune-specific NOX-based therapies could thus potentially be used to preserve metabolic and neurologic function in the context of obesity.


Subject(s)
Cognition , Diet, High-Fat/adverse effects , Gene Deletion , Membrane Glycoproteins/deficiency , Membrane Glycoproteins/genetics , Myeloid Cells/metabolism , NADPH Oxidases/deficiency , NADPH Oxidases/genetics , Animals , Body Composition/genetics , Body Weight/genetics , Brain/physiology , Cell Lineage , Gene Knockout Techniques , Intra-Abdominal Fat/metabolism , Mice , NADPH Oxidase 2
8.
PLoS One ; 12(4): e0175577, 2017.
Article in English | MEDLINE | ID: mdl-28441394

ABSTRACT

Maternal obesity is known to predispose offspring to metabolic and neurodevelopmental abnormalities. While the mechanisms underlying these phenomena are unclear, high fat diets dramatically alter intestinal microbiota, and gut microbiota can impact physiological function. To determine if maternal diet-induced gut dysbiosis can disrupt offspring neurobehavioral function, we transplanted high fat diet- (HFD) or control low fat diet-associated (CD) gut microbiota to conventionally-housed female mice. Recipient mice were then bred and the behavioral phenotype of male and female offspring was tracked. While maternal behavior was unaffected, neonatal offspring from HFD dams vocalized less upon maternal separation than pups from CD dams. Furthermore, weaned male offspring from HFD dams had significant and selective disruptions in exploratory, cognitive, and stereotypical/compulsive behavior compared to male offspring from CD dams; while female offspring from HFD dams had increases in body weight and adiposity. 16S metagenomic analyses confirmed establishment of divergent microbiota in CD and HFD dams, with alterations in diversity and taxonomic distribution throughout pregnancy and lactation. Likewise, significant alterations in gut microbial diversity and distribution were noted in offspring from HFD dams compared to CD dams, and in males compared to females. Regression analyses of behavioral performance against differentially represented taxa suggest that decreased representation of specific members of the Firmicutes phylum predict behavioral decline in male offspring. Collectively, these data establish that high fat diet-induced maternal dysbiosis is sufficient to disrupt behavioral function in murine offspring in a sex-specific manner. Thus these data reinforce the essential link between maternal diet and neurologic programming in offspring and suggest that intestinal dysbiosis could link unhealthy modern diets to the increased prevalence of neurodevelopmental and childhood disorders.


Subject(s)
Anxiety/etiology , Cognition , Compulsive Behavior/etiology , Gastrointestinal Microbiome , Obesity/microbiology , Prenatal Exposure Delayed Effects/etiology , Adiposity , Animal Communication , Animals , Animals, Newborn , Anxiety/microbiology , Compulsive Behavior/microbiology , Female , Male , Maternal Nutritional Physiological Phenomena , Mice, Inbred C57BL , Pregnancy , Prenatal Exposure Delayed Effects/microbiology
9.
PLoS One ; 11(8): e0156732, 2016.
Article in English | MEDLINE | ID: mdl-27486898

ABSTRACT

BACKGROUND: Developing measures to detect preclinical Alzheimer's Disease is vital, as prodromal stage interventions may prove more efficacious in altering the disease's trajectory. Gait changes may serve as a useful clinical heuristic that precedes cognitive decline. This study provides the first systematic investigation of gait characteristics relationship with relevant demographic, physical, genetic (Apolipoprotein E genotype), and health risk factors in non-demented older adults during a cognitive-load dual task walking condition. METHODS: The GAITRite system provided objective measurement of gait characteristics in APOE-e4 "carriers" (n = 75) and "non-carriers" (n = 224). Analyses examined stride length and step time gait characteristics during simple and dual-task (spelling five-letter words backwards) conditions in relation to demographic, physical, genetic, and health risk factors. RESULTS: Slower step time and shorter stride length associated with older age, greater health risk, and worse physical performance (ps < .05). Men and women differed in height, gait characteristics, health risk factors and global cognition (ps < .05). APOE-e4 associated with a higher likelihood of hypercholesterolemia and overall illness index scores (ps < .05). No genotype-sex interactions on gait were found. APOE-e4 was linked to shorter stride length and greater dual-task related disturbances in stride length. CONCLUSIONS: Stride length has been linked to heightened fall risk, attention decrements and structural brain changes in older adults. Our results indicate that stride length is a useful behavioral marker of cognitive change that is associated with genetic risk for AD. Sex disparities in motor decline may be a function of health risk factors.


Subject(s)
Alzheimer Disease/genetics , Apolipoproteins E/genetics , Gait Disorders, Neurologic/physiopathology , Gait/genetics , Hypercholesterolemia/epidemiology , Age Factors , Aged , Alzheimer Disease/physiopathology , Female , Gait Disorders, Neurologic/genetics , Genetic Predisposition to Disease , Genetic Variation , Genotype , Humans , Male , Middle Aged , Sex Characteristics
10.
Biochim Biophys Acta ; 1862(6): 1228-35, 2016 06.
Article in English | MEDLINE | ID: mdl-26912411

ABSTRACT

HIV protease inhibitors are key components of HIV antiretroviral therapies, which are fundamental in the treatment of HIV infection. However, the protease inhibitors are well-known to induce metabolic dysfunction which can in turn escalate the complications of HIV, including HIV associated neurocognitive disorders. As experimental and epidemiological data support a therapeutic role for adiponectin in both metabolic and neurologic homeostasis, this study was designed to determine if increased adiponectin could prevent the detrimental effects of protease inhibitors in mice. Adult male wild type (WT) and adiponectin-overexpressing (ADTg) mice were thus subjected to a 4-week regimen of lopinavir/ritonavir, followed by comprehensive metabolic, neurobehavioral, and neurochemical analyses. Data show that lopinavir/ritonavir-induced lipodystrophy, hypoadiponectinemia, hyperglycemia, hyperinsulinemia, and hypertriglyceridemia were attenuated in ADTg mice. Furthermore, cognitive function and blood-brain barrier integrity were preserved, while loss of cerebrovascular markers and white matter injury were prevented in ADTg mice. Finally, lopinavir/ritonavir caused significant increases in expression of markers of brain inflammation and decreases in synaptic markers in WT, but not in ADTg mice. Collectively, these data reinforce the pathophysiologic link from metabolic dysfunction to loss of cerebrovascular and cognitive homeostasis; and suggest that preservation and/or replacement of adiponectin could prevent these key aspects of HIV protease inhibitor-induced toxicity in clinical settings.


Subject(s)
Adiponectin/metabolism , Brain Injuries/chemically induced , Brain/blood supply , HIV Protease Inhibitors/adverse effects , Lopinavir/adverse effects , Ritonavir/adverse effects , Adiponectin/genetics , Animals , Blood-Brain Barrier/drug effects , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Brain/drug effects , Brain/pathology , Brain Injuries/metabolism , Brain Injuries/pathology , Cognition/drug effects , HIV Infections/drug therapy , Homeostasis/drug effects , Male , Mice , Mice, Inbred C57BL , Up-Regulation
12.
Am J Transl Res ; 8(12): 5309-5319, 2016.
Article in English | MEDLINE | ID: mdl-28078004

ABSTRACT

Nuclear factor E2-related factor 2 (NRF2) is a well-known master controller of the cellular adaptive antioxidant and detoxification response. Recent studies demonstrated altered glucose, lipid and energy metabolism in mice with a global Nrf2 knockout. In the present study, we aim to determine the effects of an adipose-specific ablation of Nrf2 (ASAN) on diet-induced obesity (DIO) in male mice. The 6-week-old adipose-specific Nrf2 knockout (NK) and its Nrf2 control (NC) mice were fed with either control diet (CD) or high-fat diet (HFD) for 14 weeks. NK mice exhibited transiently delayed body weight (BW) growth from week 5 to week 11 of HFD feeding, higher daily physical activity levels and preferential use of fat over carbohydrates as a source of energy at week 8 of the CD-feeding period. After 14 weeks of feeding, NK mice showed comparable results with NC mice with respect to the overall BW and body fat content, but exhibited reduced blood glucose, reduced number but increased size of adipocytes, accompanied with elevated expression of many genes and proteins in the visceral fat related to glucose, lipid and energy metabolism (e.g. Fgf21, Pgc1a). These results indicated that NRF2 is an important mediator for glucose, lipid and energy metabolism in adipose tissue, and ASAN could have beneficial effect for prevention of DIO during the early development of mice.

13.
Biochim Biophys Acta ; 1862(2): 274-83, 2016 02.
Article in English | MEDLINE | ID: mdl-26554604

ABSTRACT

Recent clinical and laboratory evidences suggest that high fat diet (HFD) induced obesity and its associated metabolic syndrome conditions promotes neuropathology in aging and age-related neurological disorders. However, the effects of high fat diet on brain pathology are poorly understood, and the effective strategies to overcome these effects remain elusive. In the current study, we examined the effects of HFD on brain pathology and further evaluated whether donepezil, an AChE inhibitor with neuroprotective functions, could suppress the ongoing HFD induced pathological changes in the brain. Our data demonstrates that HFD induced obesity results in increased neuroinflammation and increased AChE activity in the brain when compared with the mice fed on low fat diet (LFD). HFD administration to mice activated mTOR pathway resulting in increased phosphorylation of mTOR(ser2448), AKT(thr308) and S6K proteins involved in the signaling. Interestingly, donepezil administration with HFD suppressed HFD induced increases in AChE activity, and partially reversed HFD effects on microglial reactivity and the levels of mTOR signaling proteins in the brain when compared to the mice on LFD alone. However, gross levels of synaptic proteins were not altered in the brain tissues of mice fed either diet with or without donepezil. In conclusion, these results present a new insight into the detrimental effects of HFD on brain via microglial activation and involvement of mTOR pathway, and further demonstrates the possible therapeutic role for donepezil in ameliorating the early effects of HFD that could help preserve the brain function in metabolic syndrome conditions.


Subject(s)
Brain/drug effects , Cholinesterase Inhibitors/therapeutic use , Diet, High-Fat/adverse effects , Donepezil/therapeutic use , Inflammation/drug therapy , Inflammation/etiology , TOR Serine-Threonine Kinases/immunology , Animals , Brain/immunology , Brain/pathology , Cholinesterase Inhibitors/pharmacology , Donepezil/pharmacology , Inflammation/immunology , Inflammation/pathology , Male , Mice, Inbred C57BL , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Obesity/drug therapy , Obesity/etiology , Obesity/immunology , Signal Transduction/drug effects , Synapses/drug effects , Synapses/immunology , Synapses/pathology
14.
Mol Neurobiol ; 53(5): 3168-3178, 2016 07.
Article in English | MEDLINE | ID: mdl-26033219

ABSTRACT

Ghrelin is an orexigenic hormone with a role in the onset and progression of neurodegenerative disorders. It has been recently associated to Alzheimer's disease (AD) for its neuroprotective and anti-apoptotic activity. In the present study, we dissected the effect of ghrelin treatment on the two major intracellular proteolytic pathways, the ubiquitin-proteasome system (UPS) and autophagy, in cellular models of AD (namely SH-SY5Y neuroblastoma cells stably transfected with either the wild-type AßPP gene or the 717 valine-to-glycine AßPP-mutated gene). Ghrelin showed a growth-promoting effect on neuronal cells inducing also time-dependent modifications of the growth hormone secretagogue receptor type 1 (GHS-R1) expression. Interestingly, we demonstrated for the first time that ghrelin was able to activate the proteasome in neural cells playing also a role in the interplay between the UPS and autophagy. Our data provide a novel mechanism by which circulating hormones control neural homeostasis through the regulation of proteolytic pathways implicated in AD.


Subject(s)
Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Ghrelin/pharmacology , Neurons/metabolism , Neurons/pathology , Proteolysis/drug effects , Apoptosis/drug effects , Autophagy/drug effects , Beclin-1/metabolism , Cathepsin B/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Humans , Microtubule-Associated Proteins/metabolism , Neurons/drug effects , Proteasome Endopeptidase Complex/metabolism , Receptors, Ghrelin/metabolism , Sequestosome-1 Protein/metabolism , Transfection , Ubiquitin/metabolism
15.
J Neuropathol Exp Neurol ; 74(11): 1093-118, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26469251

ABSTRACT

Despite effective viral suppression through combined antiretroviral therapy (cART), approximately half of HIV-positive individuals have HIV-associated neurocognitive disorders (HAND). Studies of antiretroviral-treated patients have revealed persistent white matter abnormalities including diffuse myelin pallor, diminished white matter tracts, and decreased myelin protein mRNAs. Loss of myelin can contribute to neurocognitive dysfunction because the myelin membrane generated by oligodendrocytes is essential for rapid signal transduction and axonal maintenance. We hypothesized that myelin changes in HAND are partly due to effects of antiretroviral drugs on oligodendrocyte survival and/or maturation. We showed that primary mouse oligodendrocyte precursor cell cultures treated with therapeutic concentrations of HIV protease inhibitors ritonavir or lopinavir displayed dose-dependent decreases in oligodendrocyte maturation; however, this effect was rapidly reversed after drug removal. Conversely, nucleoside reverse transcriptase inhibitor zidovudine had no effect. Furthermore, in vivo ritonavir administration to adult mice reduced frontal cortex myelin protein levels. Finally, prefrontal cortex tissue from HIV-positive individuals with HAND on cART showed a significant decrease in myelin basic protein compared with untreated HIV-positive individuals with HAND or HIV-negative controls. These findings demonstrate that antiretrovirals can impact myelin integrity and have implications for myelination in juvenile HIV patients and myelin maintenance in adults on lifelong therapy.


Subject(s)
Antirheumatic Agents/therapeutic use , Gene Expression Regulation, Viral/drug effects , HIV Infections , Myelin Sheath/drug effects , Oligodendroglia/drug effects , Adult , Animals , Animals, Newborn , Cell Differentiation/drug effects , Cells, Cultured , Cognition Disorders/etiology , Cohort Studies , Disease Models, Animal , Gangliosides/metabolism , Gene Expression Regulation, Viral/physiology , HIV Infections/complications , HIV Infections/drug therapy , HIV Infections/pathology , Humans , Male , Mice , Mice, Inbred C57BL , Middle Aged , Myelin Basic Protein/metabolism , Myelin Proteolipid Protein/metabolism , Myelin Sheath/virology , Oligodendroglia/virology , Reactive Oxygen Species/metabolism
16.
Front Aging Neurosci ; 7: 34, 2015.
Article in English | MEDLINE | ID: mdl-25852548

ABSTRACT

Gait abnormalities are linked to cognitive decline and an increased fall risk within older adults. The present study addressed gaps from cross-sectional studies in the literature by longitudinally examining the interplay between temporal and spatial aspects of gait, cognitive function, age, and lower-extremity strength in elderly "fallers" and "non-fallers". Gait characteristics, neuropsychological and physical test performance were examined at two time points spaced a year apart in cognitively intact individuals aged 60 and older (N = 416). Mixed-model repeated-measure ANCOVAs examined temporal (step time) and spatial (stride length) gait characteristics during a simple and cognitive-load walking task in fallers as compared to non-fallers. Fallers consistently demonstrated significant alterations in spatial, but not temporal, aspects of gait as compared to non-fallers during both walking tasks. Step time became slower as stride length shortened amongst all participants during the dual task. Shorter strides and slower step times during the dual task were both predicted by worse executive attention/processing speed performance. In summary, divided attention significantly impacts spatial aspects of gait in "fallers", suggesting stride length changes may precede declines in other neuropsychological and gait characteristics, thereby selectively increasing fall risk. Our results indicate that multimodal intervention approaches that integrate physical and cognitive remediation strategies may increase the effectiveness of fall risk interventions.

17.
Biol Psychiatry ; 77(7): 607-15, 2015 Apr 01.
Article in English | MEDLINE | ID: mdl-25173628

ABSTRACT

BACKGROUND: The prevalence of mental illness, particularly depression and dementia, is increased by obesity. Here, we test the hypothesis that obesity-associated changes in gut microbiota are intrinsically able to impair neurocognitive behavior in mice. METHODS: Conventionally housed, nonobese, adult male C57BL/6 mice maintained on a normal chow diet were subjected to a microbiome depletion/transplantation paradigm using microbiota isolated from donors on either a high-fat diet (HFD) or control diet. Following re-colonization, mice were subjected to comprehensive behavioral and biochemical analyses. RESULTS: The mice given HFD microbiota had significant and selective disruptions in exploratory, cognitive, and stereotypical behavior compared with mice with control diet microbiota in the absence of significant differences in body weight. Sequencing-based phylogenetic analysis confirmed the presence of distinct core microbiota between groups, with alterations in α- and ß-diversity, modulation in taxonomic distribution, and statistically significant alterations to metabolically active taxa. HFD microbiota also disrupted markers of intestinal barrier function, increased circulating endotoxin, and increased lymphocyte expression of ionized calcium-binding adapter molecule 1, toll-like receptor 2, and toll-like receptor 4. Finally, evaluation of brain homogenates revealed that HFD-shaped microbiota increased neuroinflammation and disrupted cerebrovascular homeostasis. CONCLUSIONS: Collectively, these data reinforce the link between gut dysbiosis and neurologic dysfunction and suggest that dietary and/or pharmacologic manipulation of gut microbiota could attenuate the neurologic complications of obesity.


Subject(s)
Gastrointestinal Tract/microbiology , Microbiota , Obesity/microbiology , Obesity/physiopathology , Animals , Body Weight/physiology , Brain/physiopathology , Diet, High-Fat/adverse effects , Exploratory Behavior/physiology , Gastrointestinal Tract/physiopathology , Male , Memory/physiology , Mice, Inbred C57BL , Microbiota/genetics , Motor Activity/physiology , Obesity/psychology , Stereotyped Behavior/physiology
18.
PLoS One ; 9(6): e99436, 2014.
Article in English | MEDLINE | ID: mdl-24905590

ABSTRACT

Neuropsychological abilities have found to explain a large proportion of variance in objective measures of walking gait that predict both dementia and falling within the elderly. However, to this date there has been little research on the interplay between changes in these neuropsychological processes and walking gait overtime. To our knowledge, the present study is the first to investigate intra-individual changes in neurocognitive test performance and gait step time at two-time points across a one-year span. Neuropsychological test scores from 440 elderly individuals deemed cognitively normal at Year One were analyzed via repeated measures t-tests to assess for decline in cognitive performance at Year Two. 34 of these 440 individuals neuropsychological test performance significantly declined at Year Two; whereas the "non-decliners" displayed improved memory, working memory, attention/processing speed test performance. Neuropsychological test scores were also submitted to factor analysis at both time points for data reduction purposes and to assess the factor stability overtime. Results at Year One yielded a three-factor solution: Language/Memory, Executive Attention/Processing Speed, and Working Memory. Year Two's test scores also generated a three-factor solution (Working Memory, Language/Executive Attention/Processing Speed, and Memory). Notably, language measures loaded on Executive Attention/Processing Speed rather than on the Memory factor at Year Two. Hierarchal multiple regression revealed that both Executive Attention/Processing Speed and sex significantly predicted variance in dual task step time at both time points. Remarkably, in the "decliners", the magnitude of the contribution of the neuropsychological characteristics to gait variance significantly increased at Year Two. In summary, this study provides longitudinal evidence of the dynamic relationship between intra-individual cognitive change and its influence on dual task gait step time. These results also indicate that the failure to show improved test performance (particularly, on memory tests) with repeated administrations might prove to be useful of indicator of early cognitive decline.


Subject(s)
Aging , Cognition Disorders/physiopathology , Cognition , Gait , Memory, Short-Term , Walking , Aged , Aged, 80 and over , Female , Humans , Longitudinal Studies , Male
19.
J Neuroimmune Pharmacol ; 9(3): 388-98, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24562631

ABSTRACT

HIV protease inhibitors (PI) are fundamental to combination antiretroviral therapy, which has revolutionized HIV clinical care and produced significant reductions in HIV-associated morbidity and mortality. However, PI administration is frequently associated with severe metabolic impairment, including lipodystrophy, dyslipidemia, and insulin resistance; all of which can contribute to cardiovascular and neurologic co-morbidities. Experimental and epidemiological data support a potentially important role for the adipokine adiponectin in both metabolic and neurologic physiology. This study examined if ADP355, a novel, peptide-based adiponectin receptor agonist, could neutralize the detrimental effects of PI treatment in experimental animal models. Adult male C57BL/6 mice were subjected to a clinically relevant, 4-week regimen of lopinavir/ritonavir, with daily injections of ADP355 administered only during the final 2 weeks of PI exposure. Comprehensive metabolic, neurobehavioral, and biochemical analyses revealed that ADP355 administration partially reversed PI-induced loss of subcutaneous adipose tissue, attenuated PI-induced hyperinsulinemia, hypertriglyceridemia, and hypoadiponectinemia, and prevented PI-induced cognitive impairment and brain injury. Collectively, these data reinforce the link between metabolic co-morbidities and cognitive impairment and suggest that pharmacological reactivation of adiponectin pathways could remediate key aspects of PI-induced metabolic syndrome in clinical settings. Furthermore, therapeutic targeting of adiponectin receptors could show utility in reducing the prevalence and/or severity of HIV-associated neurocognitive disorders.


Subject(s)
Adiponectin/analogs & derivatives , Brain Injuries/chemically induced , Brain Injuries/prevention & control , Drug Design , HIV Protease Inhibitors/toxicity , Receptors, Adiponectin/agonists , Adiponectin/chemistry , Adiponectin/therapeutic use , Animals , Brain Injuries/metabolism , Male , Mice , Mice, Inbred C57BL , Receptors, Adiponectin/metabolism
20.
PLoS One ; 8(6): e65925, 2013.
Article in English | MEDLINE | ID: mdl-23776570

ABSTRACT

While considerable knowledge has been gained through the use of established cognitive and motor assessment tools, there is a considerable interest and need for the development of a battery of reliable and validated assessment tools that provide real-time and remote analysis of cognitive and motor function in the elderly. Smartphones appear to be an obvious choice for the development of these "next-generation" assessment tools for geriatric research, although to date no studies have reported on the use of smartphone-based applications for the study of cognition in the elderly. The primary focus of the current study was to assess the feasibility, reliability, and validity of a smartphone-based application for the assessment of cognitive function in the elderly. A total of 57 non-demented elderly individuals were administered a newly developed smartphone application-based Color-Shape Test (CST) in order to determine its utility in measuring cognitive processing speed in the elderly. Validity of this novel cognitive task was assessed by correlating performance on the CST with scores on widely accepted assessments of cognitive function. Scores on the CST were significantly correlated with global cognition (Mini-Mental State Exam: r = 0.515, p<0.0001) and multiple measures of processing speed and attention (Digit Span: r = 0.427, p<0.0001; Trail Making Test: r = -0.651, p<0.00001; Digit Symbol Test: r = 0.508, p<0.0001). The CST was not correlated with naming and verbal fluency tasks (Boston Naming Test, Vegetable/Animal Naming) or memory tasks (Logical Memory Test). Test re-test reliability was observed to be significant (r = 0.726; p = 0.02). Together, these data are the first to demonstrate the feasibility, reliability, and validity of using a smartphone-based application for the purpose of assessing cognitive function in the elderly. The importance of these findings for the establishment of smartphone-based assessment batteries of cognitive and motor function in the elderly is discussed.


Subject(s)
Cell Phone , Cognition/physiology , Aged , Dementia/diagnosis , Dementia/physiopathology , Female , Humans , Male , Neuropsychological Tests
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