1
|
Malik S, Xavier S, Soch A, Younesi S, Yip J, Slayo M, Barrientos RM, Sominsky L, Spencer SJ. High-fat diet and aging-associated memory impairments persist in the absence of microglia in female rats. Neurobiol Aging 2024; 140:22-32. [PMID: 38703636 DOI: 10.1016/j.neurobiolaging.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/06/2024]
Abstract
Aging is associated with a priming of microglia such that they are hypersensitive to further immune challenges. As such high-fat diet during aging can have detrimental effects on cognition that is not seen in the young. However, conflicting findings also suggest that obesity may protect against cognitive decline during aging. Given this uncertainty we aimed here to examine the role of microglia in high-fat, high-sucrose diet (HFSD)-induced changes in cognitive performance in the aging brain. We hypothesised that 8 weeks of HFSD-feeding would alter microglia and the inflammatory milieu in aging and worsen aging-related cognitive deficits in a microglia-dependent manner. We found that both aging and HFSD reduced hippocampal neuron numbers and open field exploration; they also impaired recognition memory. However, the aging-related deficits occurred in the absence of a pro-inflammatory response and the deficits in memory performance persisted after depletion of microglia in the Cx3cr1-Dtr knock-in rat. Our data suggest that mechanisms additional to the acute microglial contribution play a role in aging- and HFSD-associated memory dysfunction.
Collapse
Affiliation(s)
- Sajida Malik
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia; IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Soniya Xavier
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia
| | - Alita Soch
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia; The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
| | - Simin Younesi
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia; Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Jackson Yip
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia
| | - Mary Slayo
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia; Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Germany; Center for Mind, Brain and Behavior-CMBB, Giessen, Marburg, Germany
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH, USA
| | - Luba Sominsky
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia; Barwon Health, Geelong, Victoria, Australia; IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Sarah J Spencer
- School of Health and Biomedical Sciences RMIT University, Melbourne, VIC, Australia.
| |
Collapse
|
2
|
Muscat SM, Butler MJ, Bettes MN, DeMarsh JW, Scaria EA, Deems NP, Barrientos RM. Post-operative cognitive dysfunction is exacerbated by high-fat diet via TLR4 and prevented by dietary DHA supplementation. Brain Behav Immun 2024; 116:385-401. [PMID: 38145855 PMCID: PMC10872288 DOI: 10.1016/j.bbi.2023.12.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 12/04/2023] [Accepted: 12/20/2023] [Indexed: 12/27/2023] Open
Abstract
Post-operative cognitive dysfunction (POCD) is an abrupt decline in neurocognitive function arising shortly after surgery and persisting for weeks to months, increasing the risk of dementia diagnosis. Advanced age, obesity, and comorbidities linked to high-fat diet (HFD) consumption such as diabetes and hypertension have been identified as risk factors for POCD, although underlying mechanisms remain unclear. We have previously shown that surgery alone, or 3-days of HFD can each evoke sufficient neuroinflammation to cause memory deficits in aged, but not young rats. The aim of the present study was to determine if HFD consumption before surgery would potentiate and prolong the subsequent neuroinflammatory response and memory deficits, and if so, to determine the extent to which these effects depend on activation of the innate immune receptor TLR4, which both insults are known to stimulate. Young-adult (3mo) & aged (24mo) male F344xBN F1 rats were fed standard chow or HFD for 3-days immediately before sham surgery or laparotomy. In aged rats, the combination of HFD and surgery caused persistent deficits in contextual memory and cued-fear memory, though it was determined that HFD alone was sufficient to cause the long-lasting cued-fear memory deficits. In young adult rats, HFD + surgery caused only cued-fear memory deficits. Elevated proinflammatory gene expression in the hippocampus of both young and aged rats that received HFD + surgery persisted for at least 3-weeks after surgery. In a separate experiment, rats were administered the TLR4-specific antagonist, LPS-RS, immediately before HFD onset, which ameliorated the HFD + surgery-associated neuroinflammation and memory deficits. Similarly, dietary DHA supplementation for 4 weeks prior to HFD onset blunted the neuroinflammatory response to surgery and prevented development of persistent memory deficits. These results suggest that HFD 1) increases risk of persistent POCD-associated memory impairments following surgery in male rats in 2) a TLR4-dependent manner, which 3) can be targeted by DHA supplementation to mitigate development of persistent POCD.
Collapse
Affiliation(s)
- Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA
| | - Michael J Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Menaz N Bettes
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - James W DeMarsh
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Emmanuel A Scaria
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Department of Psychiatry & Behavioral Health, The Ohio State University, Columbus, OH, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
3
|
Leuner B. Microglia and age-related cognitive decline: Primed for sex differences. Brain Behav Immun 2024; 116:267-268. [PMID: 38096924 DOI: 10.1016/j.bbi.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 12/25/2023] Open
Affiliation(s)
- Benedetta Leuner
- Departments of Psychology and Neuroscience, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
4
|
Herrera G, Silvero C MJ, Becerra MC, Lasaga M, Scimonelli T. Modulatory role of α-MSH in hippocampal-dependent memory impairment, synaptic plasticity changes, oxidative stress, and astrocyte reactivity induced by short-term high-fat diet intake. Neuropharmacology 2023; 239:109688. [PMID: 37591460 DOI: 10.1016/j.neuropharm.2023.109688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/11/2023] [Accepted: 08/12/2023] [Indexed: 08/19/2023]
Abstract
High-fat diet (HFD) consumption is associated with cognitive deficits and neurodegenerative diseases. Since the hippocampus is extremely sensitive to pathophysiological changes, neuroinflammation and the concomitant oxidative stress induced by HFD can significantly interfere with hippocampal-dependent functions related to learning and memory. The neuropeptide alpha-melanocyte stimulating hormone (α-MSH) mediates neuroprotective actions in the central nervous system and can reverse the effects of neuroinflammation in cognitive functions that depend on the hippocampus. In this study, we used male Wistar rats to evaluate the effect of short-term HFD intake (5 days) plus a mild immune challenge, Lipopolysaccharide (LPS 10 μg/kg) on contextual fear, changes in structural plasticity, oxidative stress, and astrocyte reactivation in the hippocampus. We also determined the possible modulatory role of α-MSH. HFD consumption was associated with an increase in markers of oxidative stress (Advanced oxidation protein products and Malondialdehyde) in the dorsal hippocampus (DH). We also found changes in hippocampal structural synaptic plasticity, observing a decrease in total spine in the DH after HFD plus LPS. We observed astrocyte proliferation and a significant increase in the percentage of the area occupied by GFAP. Treatment with α-MSH (0.1 μg/0.25 μl) in the DH reversed the effect of short-term HFD plus LPS on contextual fear memory, oxidative stress, and spine density. α-MSH also reduced astrocyte proliferation. Our present results indicate that HFD consumption for a short period sensitizes the central nervous system (CNS) to a subsequent immune challenge and impairs contextual fear memory and that α-MSH could have a modulatory protective effect.
Collapse
Affiliation(s)
- Guadalupe Herrera
- Instituto de Farmacología Experimental de Córdoba, IFEC-CONICET. Departamento de Farmacología Otto Orshinger, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
| | - M Jazmín Silvero C
- Unidad de Investigación y Desarrollo en Tecnología Farmacéutica UNITEFA-CONICET. Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - M Cecilia Becerra
- Unidad de Investigación y Desarrollo en Tecnología Farmacéutica UNITEFA-CONICET. Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Mercedes Lasaga
- Instituto de Investigaciones Biomédicas INBIOMED UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Argentina
| | - Teresa Scimonelli
- Instituto de Farmacología Experimental de Córdoba, IFEC-CONICET. Departamento de Farmacología Otto Orshinger, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| |
Collapse
|
5
|
Ince LM, Darling JS, Sanchez K, Bell KS, Melbourne JK, Davis LK, Nixon K, Gaudet AD, Fonken LK. Sex differences in microglia function in aged rats underlie vulnerability to cognitive decline. Brain Behav Immun 2023; 114:438-452. [PMID: 37709153 PMCID: PMC10790303 DOI: 10.1016/j.bbi.2023.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/07/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023] Open
Abstract
Aging is associated with a significant shift in immune system reactivity ("inflammaging"), as basal inflammation increases but protective responses to infection are compromised. The immune system exhibits considerable sex differences, which may influence the process of inflammaging, including immune cell activation and behavioral consequences of immune signaling (i.e., impaired memory). Here, we test the hypothesis that sex differences in immune aging may mediate sex differences in cognitive decline. Aged male and female rats received peripheral immune stimulation using lipopolysaccharide (LPS), then molecular, cellular, and behavioral outcomes were assessed. We observed that LPS-treated aged male rats showed cognitive impairment and increased neuroinflammatory responses relative to adult males. In contrast, aged female rats did not display these aging-related deficits. Using transcriptomic and flow cytometry analyses, we further observed significant age- and sex- dependent changes in immune cell populations in the brain parenchyma and meninges, indicating a broad shift in the neuroinflammatory environment that may potentiate these behavioral effects. Ovariectomized aged female rats were also resistant to inflammation-induced memory deficits, indicating that ovarian hormones are not required for the attenuated neuroinflammation in aged females. Overall, our results indicate that males have amplified inflammatory priming with age, which contributes to age-associated cognitive decline. Our findings highlight sexual dimorphism in mechanisms of aging, and suggest that sex is a crucial consideration for identifying therapies for aging and neuroinflammation.
Collapse
Affiliation(s)
- Louise M Ince
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA
| | - Jeffrey S Darling
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA
| | - Kevin Sanchez
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA
| | - Kiersten S Bell
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA
| | - Jennifer K Melbourne
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA
| | - Lourdes K Davis
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA; Institute for Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Kimberly Nixon
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA
| | - Andrew D Gaudet
- Institute for Neuroscience, University of Texas at Austin, Austin, TX 78712, USA; Department of Psychology, University of Texas at Austin, Austin, TX 78712, USA; Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Laura K Fonken
- Division of Pharmacology & Toxicology, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA; Institute for Neuroscience, University of Texas at Austin, Austin, TX 78712, USA.
| |
Collapse
|
6
|
Nakamura Y, Koike S. Daily fat intake is associated with basolateral amygdala response to high-calorie food cues and appetite for high-calorie food. Nutr Neurosci 2023:1-9. [PMID: 37731332 DOI: 10.1080/1028415x.2023.2260585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
OBJECTIVES Animal studies have indicated that fat intake mediates amygdala activation, which in turn promotes fat intake, while amygdala activation increases the preference for fat and leads to increased fat intake. However, the association among fat intake, amygdala activation, and appetite for high-calorie foods in humans remains unclear. Thus, to examine this association, we conducted a functional magnetic resonance imaging (fMRI) experiment. METHODS Fifty healthy-weight adults (18 females; mean age: 22.9 ± 3.02 years) were included. Participants were shown images of high-calorie and low-calorie foods and were instructed to rate their desire to eat the food items during fMRI. All participants provided information on their daily fat intake using a self-reported questionnaire. Associations among fat intake, the desire to eat high-calorie or low-calorie food items, and amygdala responses to food items were examined. RESULTS The basolateral amygdala (BLA) response was positively associated with fat intake ([x, y, z] = [24, -6, -16], z = 3.91, pFWE-corrected = 0.007) and the desire to eat high-calorie food items ([26, -4, -16], z = 3.75, pFWE-corrected = 0.010). Structural equation modeling showed that the desire for high-calorie food items was predicted by BLA response to high-calorie food items (p = 0.013, β = 3.176), and BLA response was predicted by fat intake (p < 0.001, β = 0.026). DISCUSSION Fat intake influences BLA response to high-fat food, which in turn increases the desire to eat palatable high-fat food. This may lead to additional fat intake and increase the risk of weight gain.
Collapse
Affiliation(s)
- Yuko Nakamura
- Center for Evolutionary Cognitive Sciences, Graduate School of Art and Sciences, the University of Tokyo, Meguro-ku, Japan
- University of Tokyo Institute for Diversity & Adaptation of Human Mind (UTIDAHM), Meguro-ku, Japan
| | - Shinsuke Koike
- Center for Evolutionary Cognitive Sciences, Graduate School of Art and Sciences, the University of Tokyo, Meguro-ku, Japan
- University of Tokyo Institute for Diversity & Adaptation of Human Mind (UTIDAHM), Meguro-ku, Japan
- The International Research Center for Neurointelligence (WPI-IRCN), Institutes for Advanced Study (UTIAS), University of Tokyo, Bunkyo-ku, Japan
| |
Collapse
|