401
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Insulin resistance in brain alters dopamine turnover and causes behavioral disorders. Proc Natl Acad Sci U S A 2015; 112:3463-8. [PMID: 25733901 DOI: 10.1073/pnas.1500877112] [Citation(s) in RCA: 285] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Diabetes and insulin resistance are associated with altered brain imaging, depression, and increased rates of age-related cognitive impairment. Here we demonstrate that mice with a brain-specific knockout of the insulin receptor (NIRKO mice) exhibit brain mitochondrial dysfunction with reduced mitochondrial oxidative activity, increased levels of reactive oxygen species, and increased levels of lipid and protein oxidation in the striatum and nucleus accumbens. NIRKO mice also exhibit increased levels of monoamine oxidase A and B (MAO A and B) leading to increased dopamine turnover in these areas. Studies in cultured neurons and glia cells indicate that these changes in MAO A and B are a direct consequence of loss of insulin signaling. As a result, NIRKO mice develop age-related anxiety and depressive-like behaviors that can be reversed by treatment with MAO inhibitors, as well as the tricyclic antidepressant imipramine, which inhibits MAO activity and reduces oxidative stress. Thus, insulin resistance in brain induces mitochondrial and dopaminergic dysfunction leading to anxiety and depressive-like behaviors, demonstrating a potential molecular link between central insulin resistance and behavioral disorders.
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402
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Epigenetic regulation of inflammatory cytokines and associated genes in human malignancies. Mediators Inflamm 2015; 2015:201703. [PMID: 25814785 PMCID: PMC4359879 DOI: 10.1155/2015/201703] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 02/18/2015] [Indexed: 12/12/2022] Open
Abstract
Inflammation is a multifaceted defense response of immune system against infection. Chronic inflammation has been implicated as an imminent threat for major human malignancies and is directly linked to various steps involved in tumorigenesis. Inflammatory cytokines, interleukins, interferons, transforming growth factors, chemokines, and adhesion molecules have been associated with chronic inflammation. Numerous cytokines are reported to be aberrantly regulated by different epigenetic mechanisms like DNA methylation and histone modifications in tumor tissues, contributing to pathogenesis of tumor in multiple ways. Some of these cytokines also work as epigenetic regulators of other crucial genes in tumor biology, either directly or indirectly. Such regulations are reported in lung, breast, cervical, gastric, colorectal, pancreatic, prostate, and head and neck cancers. Epigenetics of inflammatory mediators in cancer is currently subject of extensive research. These investigations may help in understanding cancer biology and to develop effective therapeutic strategies. The purpose of this paper is to have a brief view of the aberrant regulation of inflammatory cytokines in human malignancies.
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403
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Barone E, Butterfield DA. Insulin resistance in Alzheimer disease: Is heme oxygenase-1 an Achille's heel? Neurobiol Dis 2015; 84:69-77. [PMID: 25731746 DOI: 10.1016/j.nbd.2015.02.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 02/18/2015] [Indexed: 01/10/2023] Open
Abstract
Insulin resistance, clinically defined as the inability of insulin to increase glucose uptake and utilization, has been found to be associated with the progression of Alzheimer disease (AD). Indeed, postmortem AD brain shows all the signs of insulin resistance including: (i) reduced brain insulin receptor (IR) sensitivity, (ii) hypophosphorylation of the insulin receptor and downstream second messengers such as IRS-1, and (iii) attenuated insulin and insulin growth factor (IGF)-1 receptor expression. However, the exact mechanisms driving insulin resistance have not been completely elucidated. Quite recently, the levels of the peripheral inducible isoform of heme oxygenase (HO-1), a well-known protein up-regulated during cell stress response, were proposed to be among the strongest positive predictors of metabolic disease, including insulin resistance. Because our group previously reported on levels, activation state and oxidative stress-induced post-translational modifications of HO-1 in AD brain and our ongoing studies to better elucidate the role of HO-1 in insulin resistance-associated AD pathology, the aim of this review is to provide reader with a critical analysis on new aspects of the interplay between HO-1 and insulin resistance and on how the available lines of evidence could be useful for further comprehension of processes in AD brain.
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Affiliation(s)
- Eugenio Barone
- Department of Biochemical Sciences, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - D Allan Butterfield
- Department of Chemistry and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA.
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404
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Neuroinflammation and Aβ accumulation linked to systemic inflammation are decreased by genetic PKR down-regulation. Sci Rep 2015; 5:8489. [PMID: 25687824 DOI: 10.1038/srep08489] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 01/15/2015] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder, marked by senile plaques composed of amyloid-β (Aβ) peptide, neurofibrillary tangles, neuronal loss and neuroinflammation. Previous works have suggested that systemic inflammation could contribute to neuroinflammation and enhanced Aβ cerebral concentrations. The molecular pathways leading to these events are not fully understood. PKR is a pro-apoptotic kinase that can trigger inflammation and accumulates in the brain and cerebrospinal fluid of AD patients. The goal of the present study was to assess if LPS-induced neuroinflammation and Aβ production could be altered by genetic PKR down regulation. The results show that, in the hippocampus of LPS-injected wild type mice, neuroinflammation, cytokine release and Aβ production are significantly increased and not in LPS-treated PKR knock-out mice. In addition BACE1 and activated STAT3 levels, a putative transcriptional regulator of BACE1, were not found increased in the brain of PKR knock-out mice as observed in wild type mice. Using PET imaging, the decrease of hippocampal metabolism induced by systemic LPS was not observed in LPS-treated PKR knock-out mice. Altogether, these findings demonstrate that PKR plays a major role in brain changes induced by LPS and could be a valid target to modulate neuroinflammation and Aβ production.
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405
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Cardiotrophin-1 (CT-1) Improves High Fat Diet-Induced Cognitive Deficits in Mice. Neurochem Res 2015; 40:843-53. [DOI: 10.1007/s11064-015-1535-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/29/2015] [Accepted: 02/04/2015] [Indexed: 01/12/2023]
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406
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Okabayashi S, Shimozawa N, Yasutomi Y, Yanagisawa K, Kimura N. Diabetes mellitus accelerates Aβ pathology in brain accompanied by enhanced GAβ generation in nonhuman primates. PLoS One 2015; 10:e0117362. [PMID: 25675436 PMCID: PMC4326359 DOI: 10.1371/journal.pone.0117362] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 12/21/2014] [Indexed: 11/18/2022] Open
Abstract
Growing evidence suggests that diabetes mellitus (DM) is one of the strongest risk factors for developing Alzheimer’s disease (AD). However, it remains unclear why DM accelerates AD pathology. In cynomolgus monkeys older than 25 years, senile plaques (SPs) are spontaneously and consistently observed in their brains, and neurofibrillary tangles are present at 32 years of age and older. In laboratory-housed monkeys, obesity is occasionally observed and frequently leads to development of type 2 DM. In the present study, we performed histopathological and biochemical analyses of brain tissue in cynomolgus monkeys with type 2 DM to clarify the relationship between DM and AD pathology. Here, we provide the evidence that DM accelerates Aβ pathology in vivo in nonhuman primates who had not undergone any genetic manipulation. In DM-affected monkey brains, SPs were observed in frontal and temporal lobe cortices, even in monkeys younger than 20 years. Biochemical analyses of brain revealed that the amount of GM1-ganglioside-bound Aβ (GAβ)—the endogenous seed for Aβ fibril formation in the brain—was clearly elevated in DM-affected monkeys. Furthermore, the level of Rab GTPases was also significantly increased in the brains of adult monkeys with DM, almost to the same levels as in aged monkeys. Intraneuronal accumulation of enlarged endosomes was also observed in DM-affected monkeys, suggesting that exacerbated endocytic disturbance may underlie the acceleration of Aβ pathology due to DM.
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Affiliation(s)
- Sachi Okabayashi
- Tsukuba Primate Research Center, National Institute of Biomedical Innovation, 1–1 Hachimandai, Tsukuba-shi, Ibaraki, 305–0843, Japan
- The Corporation for Production and Research of Laboratory Primates, 1–1 Hachimandai, Tsukuba-shi, Ibaraki, 305–0843, Japan
| | - Nobuhiro Shimozawa
- Tsukuba Primate Research Center, National Institute of Biomedical Innovation, 1–1 Hachimandai, Tsukuba-shi, Ibaraki, 305–0843, Japan
| | - Yasuhiro Yasutomi
- Tsukuba Primate Research Center, National Institute of Biomedical Innovation, 1–1 Hachimandai, Tsukuba-shi, Ibaraki, 305–0843, Japan
| | - Katsuhiko Yanagisawa
- Section of Cell Biology and Pathology, Department of Alzheimer's Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology (NCGG), Gengo 35, Moriika, Obu, Aichi, 474–8511, Japan
| | - Nobuyuki Kimura
- Tsukuba Primate Research Center, National Institute of Biomedical Innovation, 1–1 Hachimandai, Tsukuba-shi, Ibaraki, 305–0843, Japan
- Section of Cell Biology and Pathology, Department of Alzheimer's Disease Research, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology (NCGG), Gengo 35, Moriika, Obu, Aichi, 474–8511, Japan
- * E-mail:
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407
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Das SK, Sharma NK, Zhang B. Integrative network analysis reveals different pathophysiological mechanisms of insulin resistance among Caucasians and African Americans. BMC Med Genomics 2015; 8:4. [PMID: 25868721 PMCID: PMC4351975 DOI: 10.1186/s12920-015-0078-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 01/27/2015] [Indexed: 12/15/2022] Open
Abstract
Background African Americans (AA) have more pronounced insulin resistance and higher insulin secretion than European Americans (Caucasians or CA) when matched for age, gender, and body mass index (BMI). We hypothesize that physiological differences (including insulin sensitivity [SI]) between CAs and AAs can be explained by co-regulated gene networks in tissues involved in glucose homeostasis. Methods We performed integrative gene network analyses of transcriptomic data in subcutaneous adipose tissue of 99 CA and 37 AA subjects metabolically characterized as non-diabetic, with a range of SI and BMI values. Results Transcripts negatively correlated with SI in only the CA or AA subjects were enriched for inflammatory response genes and integrin-signaling genes, respectively. A sub-network (module) with TYROBP as a hub enriched for genes involved in inflammatory response (corrected p = 1.7E-26) was negatively correlated with SI (r = −0.426, p = 4.95E-04) in CA subjects. SI was positively correlated with transcript modules enriched for mitochondrial metabolism in both groups. Several SI-associated co-expressed modules were enriched for genes differentially expressed between groups. Two modules involved in immune response to viral infections and function of adherens junction, are significantly correlated with SI only in CAs. Five modules involved in drug/intracellular transport and oxidoreductase activity, among other activities, are correlated with SI only in AAs. Furthermore, we identified driver genes of these race-specific SI-associated modules. Conclusions SI-associated transcriptional networks that were deranged predominantly in one ethnic group may explain the distinctive physiological features of glucose homeostasis among AA subjects. Electronic supplementary material The online version of this article (doi:10.1186/s12920-015-0078-0) contains supplementary material, which is available to authorized users.
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408
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Maimaiti S, Anderson KL, DeMoll C, Brewer LD, Rauh BA, Gant JC, Blalock EM, Porter NM, Thibault O. Intranasal Insulin Improves Age-Related Cognitive Deficits and Reverses Electrophysiological Correlates of Brain Aging. J Gerontol A Biol Sci Med Sci 2015; 71:30-9. [PMID: 25659889 DOI: 10.1093/gerona/glu314] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/23/2014] [Indexed: 12/25/2022] Open
Abstract
Peripheral insulin resistance is a key component of metabolic syndrome associated with obesity, dyslipidemia, hypertension, and type 2 diabetes. While the impact of insulin resistance is well recognized in the periphery, it is also becoming apparent in the brain. Recent studies suggest that insulin resistance may be a factor in brain aging and Alzheimer's disease (AD) whereby intranasal insulin therapy, which delivers insulin to the brain, improves cognition and memory in AD patients. Here, we tested a clinically relevant delivery method to determine the impact of two forms of insulin, short-acting insulin lispro (Humalog) or long-acting insulin detemir (Levemir), on cognitive functions in aged F344 rats. We also explored insulin effects on the Ca(2+)-dependent hippocampal afterhyperpolarization (AHP), a well-characterized neurophysiological marker of aging which is increased in the aged, memory impaired animal. Low-dose intranasal insulin improved memory recall in aged animals such that their performance was similar to that seen in younger animals. Further, because ex vivo insulin also reduced the AHP, our results suggest that the AHP may be a novel cellular target of insulin in the brain, and improved cognitive performance following intranasal insulin therapy may be the result of insulin actions on the AHP.
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Affiliation(s)
- Shaniya Maimaiti
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - Katie L Anderson
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - Chris DeMoll
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - Lawrence D Brewer
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - Benjamin A Rauh
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - John C Gant
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - Eric M Blalock
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - Nada M Porter
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky
| | - Olivier Thibault
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky.
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409
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Kim KS, Lee YM, Lee HW, Jacobs DR, Lee DH. Associations between organochlorine pesticides and cognition in U.S. elders: National Health and Nutrition Examination Survey 1999-2002. ENVIRONMENT INTERNATIONAL 2015; 75:87-92. [PMID: 25461417 DOI: 10.1016/j.envint.2014.11.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/03/2014] [Accepted: 11/11/2014] [Indexed: 05/06/2023]
Abstract
There is limited evidence about whether background exposure to organochlorine pesticides is related to impairment of cognitive function in general populations. This study was performed to investigate cross-sectional associations between serum concentrations of organochlorine pesticides and cognitive function, a predictor of dementia, among U.S. elders without overt dementia. Study subjects were 644 elders aged 60-85, participating in the National Health and Nutrition Examination Survey 1999-2002. We selected 6 organochlorine pesticides (p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (DDE), trans-nonachlor, oxychlordane, heptachlor epoxide, and β-hexachlorocyclohexane) which were commonly detected in current general population. Cognitive function was assessed with the Digit-Symbol Substitution Test. All 6 compounds showed statistically significant or marginally significant inverse associations with cognitive score after adjusting for covariates including education levels. The strongest association was observed with p,p'-DDT. With the outcome of low cognitive score defined as <25th percentile, elders in the highest quartile of p,p'-DDT, p,p'-DDE, and β-hexachlorocyclohexane had 2 to 3 times higher risks than those in the lowest quartile. In particular, when their concentrations were further divided with the cutoff points of 90th and 95th percentiles, p,p'-DDT in the highest 5th percentile showed 6.5 (95% confidence interval: 2.6-16.3) times higher risk of low cognitive score. On the other hand, non-persistent pesticides like organophosphates or pyrethroid showed little association with this cognitive score. The potential role of background exposure to organochlorine pesticides in the development of dementia should be explored in future prospective studies and in-vitro/in-vivo experimental studies.
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Affiliation(s)
- Ki-Su Kim
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Yu-Mi Lee
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Ho-Won Lee
- Dept. of Neurology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu, Republic of Korea
| | - David R Jacobs
- Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Duk-Hee Lee
- Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea; BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, Kyungpook National University, Daegu, Republic of Korea.
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410
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Clarke JR, Lyra E Silva NM, Figueiredo CP, Frozza RL, Ledo JH, Beckman D, Katashima CK, Razolli D, Carvalho BM, Frazão R, Silveira MA, Ribeiro FC, Bomfim TR, Neves FS, Klein WL, Medeiros R, LaFerla FM, Carvalheira JB, Saad MJ, Munoz DP, Velloso LA, Ferreira ST, De Felice FG. Alzheimer-associated Aβ oligomers impact the central nervous system to induce peripheral metabolic deregulation. EMBO Mol Med 2015; 7:190-210. [PMID: 25617315 PMCID: PMC4328648 DOI: 10.15252/emmm.201404183] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is associated with peripheral metabolic disorders. Clinical/epidemiological data indicate increased risk of diabetes in AD patients. Here, we show that intracerebroventricular infusion of AD-associated Aβ oligomers (AβOs) in mice triggered peripheral glucose intolerance, a phenomenon further verified in two transgenic mouse models of AD. Systemically injected AβOs failed to induce glucose intolerance, suggesting AβOs target brain regions involved in peripheral metabolic control. Accordingly, we show that AβOs affected hypothalamic neurons in culture, inducing eukaryotic translation initiation factor 2α phosphorylation (eIF2α-P). AβOs further induced eIF2α-P and activated pro-inflammatory IKKβ/NF-κB signaling in the hypothalamus of mice and macaques. AβOs failed to trigger peripheral glucose intolerance in tumor necrosis factor-α (TNF-α) receptor 1 knockout mice. Pharmacological inhibition of brain inflammation and endoplasmic reticulum stress prevented glucose intolerance in mice, indicating that AβOs act via a central route to affect peripheral glucose homeostasis. While the hypothalamus has been largely ignored in the AD field, our findings indicate that AβOs affect this brain region and reveal novel shared molecular mechanisms between hypothalamic dysfunction in metabolic disorders and AD.
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Affiliation(s)
- Julia R Clarke
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil School of Pharmacy Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Natalia M Lyra E Silva
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Claudia P Figueiredo
- School of Pharmacy Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Rudimar L Frozza
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Jose H Ledo
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Danielle Beckman
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Carlos K Katashima
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Daniela Razolli
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Bruno M Carvalho
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Renata Frazão
- Department of Anatomy, Institute of Biomedical Sciences University of São Paulo, SP, Brazil
| | - Marina A Silveira
- Department of Anatomy, Institute of Biomedical Sciences University of São Paulo, SP, Brazil
| | - Felipe C Ribeiro
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Theresa R Bomfim
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Fernanda S Neves
- School of Pharmacy Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - William L Klein
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Rodrigo Medeiros
- Institute for Memory Impairments and Neurological Disorders University of California, Irvine, CA, USA
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders University of California, Irvine, CA, USA
| | - Jose B Carvalheira
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Mario J Saad
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Douglas P Munoz
- Center for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Licio A Velloso
- Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, SP, Brazil
| | - Sergio T Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil Institute of Biophysics Carlos Chagas Filho Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Fernanda G De Felice
- Institute of Medical Biochemistry Leopoldo de Meis Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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411
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Mouton-Liger F, Rebillat AS, Gourmaud S, Paquet C, Leguen A, Dumurgier J, Bernadelli P, Taupin V, Pradier L, Rooney T, Hugon J. PKR downregulation prevents neurodegeneration and β-amyloid production in a thiamine-deficient model. Cell Death Dis 2015; 6:e1594. [PMID: 25590804 PMCID: PMC4669750 DOI: 10.1038/cddis.2014.552] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/30/2014] [Accepted: 11/03/2014] [Indexed: 12/22/2022]
Abstract
Brain thiamine homeostasis has an important role in energy metabolism and displays reduced activity in Alzheimer's disease (AD). Thiamine deficiency (TD) induces regionally specific neuronal death in the animal and human brains associated with a mild chronic impairment of oxidative metabolism. These features make the TD model amenable to investigate the cellular mechanisms of neurodegeneration. Once activated by various cellular stresses, including oxidative stress, PKR acts as a pro-apoptotic kinase and negatively controls the protein translation leading to an increase of BACE1 translation. In this study, we used a mouse TD model to assess the involvement of PKR in neuronal death and the molecular mechanisms of AD. Our results showed that the TD model activates the PKR-eIF2α pathway, increases the BACE1 expression levels of Aβ in specific thalamus nuclei and induces motor deficits and neurodegeneration. These effects are reversed by PKR downregulation (using a specific inhibitor or in PKR knockout mice).
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Affiliation(s)
- F Mouton-Liger
- 1] Inserm UMR-S942, Paris 75010, France [2] Department of Histology, Pathology and Biochemistry, Saint Louis Lariboisière Fernand Hospital, Service AP-HP, University of Paris Diderot, Paris, France
| | | | - S Gourmaud
- 1] Inserm UMR-S942, Paris 75010, France [2] Department of Histology, Pathology and Biochemistry, Saint Louis Lariboisière Fernand Hospital, Service AP-HP, University of Paris Diderot, Paris, France
| | - C Paquet
- 1] Inserm UMR-S942, Paris 75010, France [2] Department of Histology, Pathology and Biochemistry, Saint Louis Lariboisière Fernand Hospital, Service AP-HP, University of Paris Diderot, Paris, France [3] Clinical and Research Memory Center, Paris Nord Ile de France Saint Louis Lariboisière Fernand Hospital, AP-HP, University of Paris Diderot, Paris, France
| | - A Leguen
- Inserm UMR-S942, Paris 75010, France
| | - J Dumurgier
- 1] Department of Histology, Pathology and Biochemistry, Saint Louis Lariboisière Fernand Hospital, Service AP-HP, University of Paris Diderot, Paris, France [2] Clinical and Research Memory Center, Paris Nord Ile de France Saint Louis Lariboisière Fernand Hospital, AP-HP, University of Paris Diderot, Paris, France
| | - P Bernadelli
- Sanofi-Aventis Therapeutic Strategy Unit Aging, Chilly-Mazarin, France
| | - V Taupin
- Sanofi-Aventis Therapeutic Strategy Unit Aging, Chilly-Mazarin, France
| | - L Pradier
- Sanofi-Aventis Therapeutic Strategy Unit Aging, Chilly-Mazarin, France
| | - T Rooney
- Sanofi-Aventis Therapeutic Strategy Unit Aging, Chilly-Mazarin, France
| | - J Hugon
- 1] Inserm UMR-S942, Paris 75010, France [2] Department of Histology, Pathology and Biochemistry, Saint Louis Lariboisière Fernand Hospital, Service AP-HP, University of Paris Diderot, Paris, France [3] Clinical and Research Memory Center, Paris Nord Ile de France Saint Louis Lariboisière Fernand Hospital, AP-HP, University of Paris Diderot, Paris, France
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412
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Sharma B, Kim H, Rhyu D. Caulerpa lentillifera extract ameliorates insulin resistance and regulates glucose metabolism in C57BL/KsJ-db/db mice via PI3K/AKT signaling pathway in myocytes. J Transl Med 2015; 13:62. [PMID: 25889508 PMCID: PMC4350654 DOI: 10.1186/s12967-015-0412-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 01/20/2015] [Indexed: 12/22/2022] Open
Abstract
Background Glucose homeostasis is distorted by defects of the PI3K/AKT and AMPK pathways in insulin-sensitive tissues, allowing the accumulation of glucose in the blood. The purpose of this study was to assess the effects and mechanisms by which ethanol extract of Caulerpa lentillifera (CLE) regulates glucose metabolism in C57BL/KsJ-db/db (db/db) mice. Methods Mice were administered CLE (250 or 500 mg/kg BW) or rosiglitazone (RSG, 10 mg/kg BW) for 6 weeks. Then, oral glucose tolerance test (OGTT) and intraperitoneal insulin tolerance test (IPITT) were performed, and blood glucose was measured in db/db mice. Levels of insulin and insulin resistance factors in plasma, glycogen content in the liver, and IRS, PI3K, AKT, and GLUT4 expressions in skeletal muscles were measured in db/db mice. Glucose uptake and insulin signaling molecules were measured in L6 myocytes, using fluorometry and Western blotting. Results CLE significantly decreased fasting blood glucose, glucose level in OGTT and IPITT, plasma insulin, homeostatic model assessment-insulin resistant (HOMA-IR), TNF-α, IL-6, FFA, TG and TC levels, and hepatic glycogen content in db/db mice. CLE significantly increased the activation of IRS, AKT, PI3K, and GLUT4, which are the key effector molecules of the PI3K/AKT pathway in L6 myocytes and the skeletal muscles of db/db mice. The enhanced glucose uptake by CLE was abolished by treatment with a PI3K inhibitor (LY294002), but not by an AMPK inhibitor (compound C) in L6 myocytes. CLE regulated glucose uptake and homeostasis via the PI3K/AKT pathway in myocytes and db/db mice, respectively. Conclusion Our results suggest that CLE could be a potential candidate for the prevention of diabetes.
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413
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Ravona-Springer R, Schnaider Beeri M. A spectrum of contributions of type 2 diabetes and related metabolic characteristics to dementia. Eur Neuropsychopharmacol 2014; 24:1945-6. [PMID: 25483324 PMCID: PMC5753418 DOI: 10.1016/j.euroneuro.2014.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Ramit Ravona-Springer
- Department of Psychiatry, Sheba Medical Center, Tel Hashomer, Israel; Sackler Faculty of Medicine, Tel Aviv University, Israel.
| | - Michal Schnaider Beeri
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Israel; Department of Psychiatry, Icahn School of Medicine, Mount Sinai, New York, USA
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414
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Palmitic acid-induced neuron cell cycle G2/M arrest and endoplasmic reticular stress through protein palmitoylation in SH-SY5Y human neuroblastoma cells. Int J Mol Sci 2014; 15:20876-99. [PMID: 25402647 PMCID: PMC4264201 DOI: 10.3390/ijms151120876] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 10/27/2014] [Accepted: 10/30/2014] [Indexed: 12/29/2022] Open
Abstract
Obesity-related neurodegenerative diseases are associated with elevated saturated fatty acids (SFAs) in the brain. An increase in SFAs, especially palmitic acid (PA), triggers neuron cell apoptosis, causing cognitive function to deteriorate. In the present study, we focused on the specific mechanism by which PA triggers SH-SY5Y neuron cell apoptosis. We found that PA induces significant neuron cell cycle arrest in the G2/M phase in SH-SY5Y cells. Our data further showed that G2/M arrest is involved in elevation of endoplasmic reticular (ER) stress according to an increase in p-eukaryotic translation inhibition factor 2α, an ER stress marker. Chronic exposure to PA also accelerates beta-amyloid accumulation, a pathological characteristic of Alzheimer’s disease. Interestingly, SFA-induced ER stress, G2/M arrest and cell apoptosis were reversed by treatment with 2-bromopalmitate, a protein palmitoylation inhibitor. These findings suggest that protein palmitoylation plays a crucial role in SFA-induced neuron cell cycle G2/M arrest, ER stress and apoptosis; this provides a novel strategy for preventing SFA-induced neuron cell dysfunction.
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415
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Kirkland JL, Tchkonia T. Clinical strategies and animal models for developing senolytic agents. Exp Gerontol 2014; 68:19-25. [PMID: 25446976 DOI: 10.1016/j.exger.2014.10.012] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 10/20/2014] [Accepted: 10/26/2014] [Indexed: 10/24/2022]
Abstract
Aging is associated with increasing predisposition to multiple chronic diseases. One fundamental aging process that is often operative at sites of the pathology underlying chronic age-related diseases is cellular senescence. Small molecule senolytic agents are being developed. For successful drug development: 1) appropriate animal models of human age-related diseases need to be devised. 2) Models have to be made in which it can be proven that beneficial phenotypic effects are actually caused through clearing senescent cells by putative senolytic agents, as opposed to "off-target" effects of these agents on non-senescent cells. 3) Models are needed to test efficacy of drugs and to uncover potential side effects of senolytic agents. Development of the optimal animal models and clinical trial paradigms for senolytic agents warrants an intensive effort, since senolytic agents, if successful in delaying, preventing, alleviating, or reversing age-related diseases as a group would be transformative.
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Affiliation(s)
- James L Kirkland
- Mayo Clinic Robert and Arlene Kogod Center on Aging, 200 First Street, S.W., Rochester, MN 55905, United States.
| | - Tamara Tchkonia
- Mayo Clinic Robert and Arlene Kogod Center on Aging, 200 First Street, S.W., Rochester, MN 55905, United States
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416
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Jestadi DB, Phaniendra A, Babji U, Srinu T, Shanmuganathan B, Periyasamy L. Effects of short term exposure of atrazine on the liver and kidney of normal and diabetic rats. J Toxicol 2014; 2014:536759. [PMID: 25349608 PMCID: PMC4198780 DOI: 10.1155/2014/536759] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/27/2014] [Accepted: 09/01/2014] [Indexed: 02/02/2023] Open
Abstract
The present study evaluates the effects of short term (15 days) exposure of low dose (300 μg kg(-1)) of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) on antioxidant status and markers of liver and kidney damage in normal (nondiabetic) and diabetic male Wistar rats. Rats were divided into four groups: Group I as normal control, Group II as atrazine treated, Group III as diabetic control, and Group IV as atrazine treated diabetic rats. Atrazine administration resulted in increased MDA concentration as well as increased activities of SOD, CAT, and GPx in both liver and kidney of atrazine treated and atrazine treated diabetic rats. However, GSH level was decreased in both liver and kidney of atrazine treated and atrazine treated diabetic rats. Atrazine administration led to significant increase in liver damage biomarkers such as AST, ALT, and ALP as well as kidney damage biomarkers such as creatinine and urea in both normal and diabetic rats, but this increase was more pronounced in diabetic rats when compared to normal rats. In conclusion, the results of the present study demonstrate that short term exposure of atrazine at a dose of 300 μg kg(-1) could potentially induce oxidative damage in liver and kidney of both normal and diabetic rats.
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Affiliation(s)
- Dinesh Babu Jestadi
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Alugoju Phaniendra
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Undru Babji
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Thupakula Srinu
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Bhavatharini Shanmuganathan
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Latha Periyasamy
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
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417
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Insulin resistance in Alzheimer's disease. Neurobiol Dis 2014; 72 Pt A:92-103. [PMID: 25237037 DOI: 10.1016/j.nbd.2014.09.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 09/02/2014] [Accepted: 09/05/2014] [Indexed: 12/16/2022] Open
Abstract
Insulin is a key hormone regulating metabolism. Insulin binding to cell surface insulin receptors engages many signaling intermediates operating in parallel and in series to control glucose, energy, and lipids while also regulating mitogenesis and development. Perturbations in the function of any of these intermediates, which occur in a variety of diseases, cause reduced sensitivity to insulin and insulin resistance with consequent metabolic dysfunction. Chronic inflammation ensues which exacerbates compromised metabolic homeostasis. Since insulin has a key role in learning and memory as well as directly regulating ERK, a kinase required for the type of learning and memory compromised in early Alzheimer's disease (AD), insulin resistance has been identified as a major risk factor for the onset of AD. Animal models of AD or insulin resistance or both demonstrate that AD pathology and impaired insulin signaling form a reciprocal relationship. Of note are human and animal model studies geared toward improving insulin resistance that have led to the identification of the nuclear receptor and transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) as an intervention tool for early AD. Strategic targeting of alternate nodes within the insulin signaling network has revealed disease-stage therapeutic windows in animal models that coalesce with previous and ongoing clinical trial approaches. Thus, exploiting the connection between insulin resistance and AD provides powerful opportunities to delineate therapeutic interventions that slow or block the pathogenesis of AD.
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418
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Is Alzheimer's disease related to metabolic syndrome? A Wnt signaling conundrum. Prog Neurobiol 2014; 121:125-46. [PMID: 25084549 DOI: 10.1016/j.pneurobio.2014.07.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/17/2014] [Accepted: 07/23/2014] [Indexed: 01/07/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia, affecting more than 36 million people worldwide. AD is characterized by a progressive loss of cognitive functions. For years, it has been thought that age is the main risk factor for AD. Recent studies suggest that life style factors, including nutritional behaviors, play a critical role in the onset of dementia. Evidence about the relationship between nutritional behavior and AD includes the role of conditions such as obesity, hypertension, dyslipidemia and elevated glucose levels. The coexistence of some of these cardio-metabolic risk factors is generally known as metabolic syndrome (MS). Some clinical studies support the role of MS in the onset of AD. However, the cross-talk between the molecular signaling implicated in these disorders is unknown. In the present review, we focus on the molecular correlates that support the relationship between MS and the onset of AD. We also discuss relevant issues such as the role of leptin, insulin and renin-angiotensin signaling in the brain and the possible role of Wnt signaling in both MS and AD. We discuss the evidence supporting the use of ob/ob mice, high-fructose diets, aortic coarctation-induced hypertension and Octodon degus, which spontaneously develops β-amyloid deposits and metabolic derangements, as suitable animal models to address the relationships between MS and AD. Finally, we examine emergent data supporting the role of Wnt signaling in the modulation of AD and MS, implicating this pathway as a therapeutic target in both conditions.
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