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Zamarbide M, Martinez-Pinilla E, Gil-Bea F, Yanagisawa M, Franco R, Perez-Mediavilla A. Genetic Inactivation of Free Fatty Acid Receptor 3 Impedes Behavioral Deficits and Pathological Hallmarks in the APP swe Alzheimer's Disease Mouse Model. Int J Mol Sci 2022; 23:ijms23073533. [PMID: 35408893 PMCID: PMC8999053 DOI: 10.3390/ijms23073533] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 01/01/2023] Open
Abstract
The free fatty acid FFA3 receptor (FFA3R) belongs to the superfamily of G-protein-coupled receptors (GPCRs). In the intestine and adipose tissue, it is involved in the regulation of energy metabolism, but its function in the brain is unknown. We aimed, first, to investigate the expression of the receptor in the hippocampus of Alzheimer disease (AD) patients at different stages of the disease and, second, to assess whether genetic inactivation of the Ffar3 gene could affect the phenotypic features of the APPswe mouse model. The expression of transcripts for FFA receptors in postmortem human hippocampal samples and in the hippocampus of wild-type and transgenic mice was analyzed by RT-qPCR. We generated a double transgenic mouse, FFA3R−/−/APPswe, to perform cognition studies and to assess, by immunoblotting Aβ and tau pathologies and the differential expression of synaptic plasticity-related proteins. For the first time, the occurrence of the FFA3R in the human hippocampus and its overexpression, even in the first stages of AD, was demonstrated. Remarkably, FFA3R−/−/APPswe mice do not have the characteristic memory impairment of 12-month-old APPswe mice. Additionally, this newly generated transgenic line does not develop the most important Alzheimer’s disease (AD)-related features, such as amyloid beta (Aβ) brain accumulations and tau hyperphosphorylation. These findings are accompanied by increased levels of the insulin-degrading enzyme (IDE) and lower activity of the tau kinases GSK3β and Cdk5. We conclude that the brain FFA3R is involved in cognitive processes and that its inactivation prevents AD-like cognitive decline and pathological hallmarks.
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Affiliation(s)
- Marta Zamarbide
- Neuroscience Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain; (M.Z.); (E.M.-P.); (F.G.-B.)
- Instituto de Investigación Sanitaria de Navarra (IDISNA), 31008 Pamplona, Spain
| | - Eva Martinez-Pinilla
- Neuroscience Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain; (M.Z.); (E.M.-P.); (F.G.-B.)
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Instituto de Neurociencias del Principado de Asturias (INEUROPA), 33003 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Francisco Gil-Bea
- Neuroscience Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain; (M.Z.); (E.M.-P.); (F.G.-B.)
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Tsukuba 305-8577, Japan;
| | - Rafael Franco
- Neuroscience Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain; (M.Z.); (E.M.-P.); (F.G.-B.)
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain
- Network Center, Neurodegenerative Diseases, CiberNed, Spanish National Health Institute “Carlos III”, 28031 Madrid, Spain
- Correspondence: (R.F.); (A.P.-M.); Tel.: +34-934021208 (R.F.); +34-948194700 (ext. 2033) (A.P.-M.)
| | - Alberto Perez-Mediavilla
- Neuroscience Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain; (M.Z.); (E.M.-P.); (F.G.-B.)
- Instituto de Investigación Sanitaria de Navarra (IDISNA), 31008 Pamplona, Spain
- Department of Biochemistry and Genetics, University of Navarra, 31008 Pamplona, Spain
- Correspondence: (R.F.); (A.P.-M.); Tel.: +34-934021208 (R.F.); +34-948194700 (ext. 2033) (A.P.-M.)
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Huang W, Hicks SN, Sondek J, Zhang Q. A fluorogenic, small molecule reporter for mammalian phospholipase C isozymes. ACS Chem Biol 2011; 6:223-8. [PMID: 21158426 DOI: 10.1021/cb100308n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Phospholipase C isozymes (PLCs) catalyze the conversion of the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP(2)) into two second messengers, inositol 1,4,5-trisphosphate and diacylglycerol. This family of enzymes are key signaling proteins that regulate the physiological responses of many extracellular stimuli such as hormones, neurotransmitters, and growth factors. Aberrant regulation of PLCs has been implicated in various diseases including cancer and Alzheimer's disease. How, when, and where PLCs are activated under different cellular contexts are still largely unknown. We have developed a fluorogenic PLC reporter, WH-15, that can be cleaved in a cascade reaction to generate fluorescent 6-aminoquinoline. When applied in enzymatic assays with either pure PLCs or cell lysates, this reporter displays more than a 20-fold fluorescence enhancement in response to PLC activity. Under assay conditions, WH-15 has comparable K(m) and V(max) with the endogenous PIP(2). This novel reporter will likely find broad applications that vary from imaging PLC activity in live cells to high-throughput screening of PLC inhibitors.
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Affiliation(s)
- Weigang Huang
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Stephanie N. Hicks
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - John Sondek
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Qisheng Zhang
- Division of Medicinal Chemistry and Natural Products and ‡Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder. Behavioural, cognitive and memory dysfunctions are characteristic symptoms of AD. The formation of amyloid plaques is currently considered as the key event of AD. Other histological hallmarks of the disease are the formation of fibrillary tangles, astrocytosis, and loss of certain neuronal systems in cortical areas of the brain. A great number of possible aetiologic and pathogenetic factors of AD have been published in the course of the last two decades. Among the toxic factors, which have been considered to contribute to the symptoms and progression of AD, ammonia deserves special interest for the following reasons: (a) Ammonia is formed in nearly all tissues and organs of the vertebrate organism; it is the most common endogenous neurotoxic compounds. Its effects on glutamatergic and GABAergic neuronal systems, the two prevailing neuronal systems of the cortical structures, are known for many years. (b) The impairment of ammonia detoxification invariably leads to severe pathology. Several symptoms and histologic aberrations of hepatic encephalopathy (HE), of which ammonia has been recognised as a pathogenetic factor, resemble those of AD. (c) The excessive formation of ammonia in the brains of AD patients has been demonstrated, and it has been shown that some AD patients exhibit elevated blood ammonia concentrations. (d) There is evidence for the involvement of aberrant lysosomal processing of beta-amyloid precursor protein (beta-APP) in the formation of amyloid deposits. Ammonia is the most important natural modulator of lysosomal protein processing. (e) Inflammatory processes and activation of microglia are widely believed to be implicated in the pathology of AD. Ammonia is able to affect the characteristic functions of microglia, such as endocytosis, and cytokine production. Based on these facts, an ammonia hypothesis of AD has first been suggested in 1993. In the present review old and new observations are discussed, which are in support of the notion that ammonia is a factor able to produce symptoms of AD and to affect the progression of the disease.
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Affiliation(s)
- Nikolaus Seiler
- Laboratory of Nutritional Oncology, Institut de Recherche Contre les Cancers de l'Appareil Digestif, Strasbourg, France.
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Shimohama S, Akaike A, Tamura Y, Matsushima H, Kume T, Fujimoto S, Takenawa T, Kimura J. Glutamate-induced antigenic changes of phospholipase C-delta in cultured cortical neurons. J Neurosci Res 1995; 41:418-26. [PMID: 7563235 DOI: 10.1002/jnr.490410315] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in signal transduction. It was previously demonstrated that an antibody to an isozyme of PLC, PLC-delta, produces intense staining of neurofibrillary tangles (NFT), the neurites surrounding senile plaque (SP) cores and neuropil threads in the brains of patients with Alzheimer's disease (AD). Although the etiology of neuronal degeneration in AD is still to be defined, excitotoxic glutamate might be a candidate. In the present study, an anti-PLC-delta antibody was used to examine the influence of glutamate on PLC-delta immunoreactivity in cultured rat cortical neurons. Exposure to glutamate caused the death of cultured cortical neurons and exhibited increased immunostaining with the anti-PLC-delta antibody. Subtoxic doses of glutamate also increased PLC-delta immunoreactivity in a dose-dependent manner. Both glutamate-induced neuronal degeneration and the increases in PLC-delta immunoreactivity were prevented by removal of extracellular Ca2+ or the application of an N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801. The glutamate-induced increase in PLC-delta immunoreactivity was also prevented by N omega-nitro-L-arginine, a nitric oxide (NO) synthase inhibitor. These results suggest that NO formation secondary to Ca2+ influx by NMDA receptor activation leads to similar modifications of PLC-delta to those seen in AD.
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Affiliation(s)
- S Shimohama
- Department of Neurology, Faculty of Medicine, Kyoto University, Japan
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