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Roberts BL, Bennett BJ, Bennett CM, Carroll JM, Dalbøge LS, Hall C, Hassouneh W, Heppner KM, Kirigiti MA, Lindsley SR, Tennant KG, True CA, Whittle A, Wolf AC, Roberts CT, Tang-Christensen M, Sleeman MW, Cowley MA, Grove KL, Kievit P. Reelin is modulated by diet-induced obesity and has direct actions on arcuate proopiomelanocortin neurons. Mol Metab 2019; 26:18-29. [PMID: 31230943 PMCID: PMC6667498 DOI: 10.1016/j.molmet.2019.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/22/2019] [Accepted: 06/04/2019] [Indexed: 11/26/2022] Open
Abstract
Objective Reelin (RELN) is a large glycoprotein involved in synapse maturation and neuronal organization throughout development. Deficits in RELN signaling contribute to multiple psychological disorders, such as autism spectrum disorder, schizophrenia, and bipolar disorder. Nutritional stress alters RELN expression in brain regions associated with these disorders; however, the involvement of RELN in the neural circuits involved in energy metabolism is unknown. The RELN receptors apolipoprotein E receptor 2 (ApoER2) and very low-density lipoprotein receptor (VLDLR) are involved in lipid metabolism and expressed in the hypothalamus. Here we explored the involvement of RELN in hypothalamic signaling and the impact of diet-induced obesity (DIO) on this system. Methods Adult male mice were fed a chow diet or maintained on a high-fat diet (HFD) for 12–16 weeks. HFD-fed DIO mice exhibited decreased ApoER2 and VLDLR expression and increased RELN protein in the hypothalamus. Electrophysiology was used to determine the mechanism by which the central fragment of RELN (CF-RELN) acts on arcuate nucleus (ARH) satiety-promoting proopiomelanocortin (POMC) neurons and the impact of DIO on this circuitry. Results CF-RELN exhibited heterogeneous presynaptic actions on inhibitory inputs onto ARH-POMC-EGFP neurons and consistent postsynaptic actions. Additionally, central administration of CF-RELN caused a significant increase in ARH c-Fos expression and an acute decrease in food intake and body weight. Conclusions We conclude that RELN signaling is modulated by diet, that RELN is involved in synaptic signaling onto ARH-POMC neurons, and that altering central CF-RELN levels can impact food intake and body weight. Diet-induced obesity alters reelin protein levels and expression of ApoER2 and VLDLR. Reelin has direct, but divergent actions on GABAergic inputs onto POMC neurons. Central administration of reelin protein decreases food intake and body weight.
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Affiliation(s)
- Brandon L Roberts
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Baylin J Bennett
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Camdin M Bennett
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Julie M Carroll
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | | | - Colin Hall
- Obesity Research Center, Novo Nordisk, Seattle, WA, 98109, USA
| | - Wafa Hassouneh
- Obesity Research Center, Novo Nordisk, Seattle, WA, 98109, USA
| | | | - Melissa A Kirigiti
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Sarah R Lindsley
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Katherine G Tennant
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Cadence A True
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Andrew Whittle
- Obesity Research Center, Novo Nordisk, Seattle, WA, 98109, USA
| | - Anitra C Wolf
- Obesity Research Center, Novo Nordisk, Seattle, WA, 98109, USA
| | - Charles T Roberts
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | | | - Mark W Sleeman
- Department of Physiology, Monash University Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Michael A Cowley
- Department of Physiology, Monash University Biomedicine Discovery Institute, Clayton, Victoria, Australia
| | - Kevin L Grove
- Obesity Research Center, Novo Nordisk, Seattle, WA, 98109, USA
| | - Paul Kievit
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Beaverton, OR, 97006, USA.
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Di Battista AM, Heinsinger NM, Rebeck GW. Alzheimer's Disease Genetic Risk Factor APOE-ε4 Also Affects Normal Brain Function. Curr Alzheimer Res 2017; 13:1200-1207. [PMID: 27033053 DOI: 10.2174/1567205013666160401115127] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 03/15/2016] [Accepted: 03/28/2016] [Indexed: 12/24/2022]
Abstract
APOE-ε4 is the strongest genetic risk factor for Alzheimer's disease (AD), and is associated with an increase in the levels of amyloid deposition and an early age of onset. Recent data demonstrate that AD pathological changes occur decades before clinical symptoms, raising questions about the precise onset of the disease. Now a convergence of approaches in mice and humans has demonstrated that APOE-ε4 affects normal brain function even very early in life in the absence of gross AD pathological changes. Normal mice expressing APOE4 have task-specific spatial learning deficits, as well as reduced NMDAR-dependent signaling and structural changes to presynaptic and postsynaptic compartments in neurons, particularly in hippocampal regions. Young humans possessing APOE-ε4 are more adept than APOE-ε4 negative individuals at some behavioral tasks, and functional magnetic resonance imaging has shown that inheritance of APOE-ε4 has specific effects on medial temporal brain activities. These findings suggest that inheritance of APOE-ε4 causes life long changes to the brain that may be related to the late risk of AD. Several possible mechanisms of how APOE-ε4 could affect brain neurochemistry, structure, and function are reviewed.
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Affiliation(s)
| | | | - G William Rebeck
- New Research Building, WP- 13, 3970 Reservoir Rd, NW, Washington, DC 20007; USA
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