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Lau JS, Lust CAC, Lecques JD, Hillyer LM, Mountjoy M, Kang JX, Robinson LE, Ma DWL. n-3 PUFA ameliorate functional outcomes following repetitive mTBI in the fat-1 mouse model. Front Nutr 2024; 11:1410884. [PMID: 39070251 PMCID: PMC11272621 DOI: 10.3389/fnut.2024.1410884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 06/28/2024] [Indexed: 07/30/2024] Open
Abstract
Purpose Repeated mild traumatic brain injuries (mTBI) are a continuing healthcare concern worldwide, given its potential for enduring adverse neurodegenerative conditions. Past research suggests a potential protective effect of n-3 polyunsaturated fatty acids (PUFA) in experimental models of mTBI. The aim of this study was to investigate whether the neuroprotective benefits of n-3 PUFA persist following repetitive weight drop injury (WDI). Methods Male fat-1 mice (n = 12), able to endogenously convert n-6 PUFA to n-3 PUFA, and their wild type (WT) counterparts (n = 12) were maintained on a 10% w/w safflower diet. At 9-10 weeks of age, both groups received one mild low-impact WDI on the closed cranium daily, for three consecutive days. Following each WDI, time to righting reflex and seeking behaviour were measured. Neurological recovery, cognitive, motor, and neurobehavioural outcomes were assessed using the Neurological Severity Score (NSS) over 7 days (168 h) post-last WDI. Brains were assessed for cerebral microhemorrhages by Prussian blue and cellular damage by glial fibrillary acidic protein (GFAP) staining. Results Fat-1 mice exhibited significantly faster righting reflex and seeking behaviour time, and lower mean NSS scores and at all post-WDI time points (p ≤ 0.05) compared to WT mice. Immunohistochemistry showed no significant difference in presence of cerebral microhemorrhage however, fat-1 mice had significantly lower GFAP staining in comparison to WT mice (p ≤ 0.05). Conclusion n-3 PUFA is effective in restoring cognitive, motor, and behavioural function after repetitive WDI, which may be mediated through reduced cellular damage of the brain.
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Affiliation(s)
- Jessi S. Lau
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Cody A. C. Lust
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | | | - Lyn M. Hillyer
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Margo Mountjoy
- Department of Family Medicine, McMaster University, Hamilton, ON, Canada
| | - Jing X. Kang
- Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Lindsay E. Robinson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - David W. L. Ma
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
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Dai Y, Dong J, Wu Y, Zhu M, Xiong W, Li H, Zhao Y, Hammock BD, Zhu X. Enhancement of the liver's neuroprotective role ameliorates traumatic brain injury pathology. Proc Natl Acad Sci U S A 2023; 120:e2301360120. [PMID: 37339206 PMCID: PMC10293829 DOI: 10.1073/pnas.2301360120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/19/2023] [Indexed: 06/22/2023] Open
Abstract
Traumatic brain injury (TBI) is a pervasive problem worldwide for which no effective treatment is currently available. Although most studies have focused on the pathology of the injured brain, we have noted that the liver plays an important role in TBI. Using two mouse models of TBI, we found that the enzymatic activity of hepatic soluble epoxide hydrolase (sEH) was rapidly decreased and then returned to normal levels following TBI, whereas such changes were not observed in the kidney, heart, spleen, or lung. Interestingly, genetic downregulation of hepatic Ephx2 (which encodes sEH) ameliorates TBI-induced neurological deficits and promotes neurological function recovery, whereas overexpression of hepatic sEH exacerbates TBI-associated neurological impairments. Furthermore, hepatic sEH ablation was found to promote the generation of A2 phenotype astrocytes and facilitate the production of various neuroprotective factors associated with astrocytes following TBI. We also observed an inverted V-shaped alteration in the plasma levels of four EET (epoxyeicosatrienoic acid) isoforms (5,6-, 8,9-,11,12-, and 14,15-EET) following TBI which were negatively correlated with hepatic sEH activity. However, hepatic sEH manipulation bidirectionally regulates the plasma levels of 14,15-EET, which rapidly crosses the blood-brain barrier. Additionally, we found that the application of 14,15-EET mimicked the neuroprotective effect of hepatic sEH ablation, while 14,15-epoxyeicosa-5(Z)-enoic acid blocked this effect, indicating that the increased plasma levels of 14,15-EET mediated the neuroprotective effect observed after hepatic sEH ablation. These results highlight the neuroprotective role of the liver in TBI and suggest that targeting hepatic EET signaling could represent a promising therapeutic strategy for treating TBI.
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Affiliation(s)
- Yongfeng Dai
- School of Basic Medical Science, Southern Medical University, Guangzhou510515, China
- Research Center for Brain Health, Pazhou Lab, Guangzhou510330, China
| | - Jinghua Dong
- School of Basic Medical Science, Southern Medical University, Guangzhou510515, China
- Research Center for Brain Health, Pazhou Lab, Guangzhou510330, China
| | - Yu Wu
- Research Center for Brain Health, Pazhou Lab, Guangzhou510330, China
- School of Psychology, Shenzhen University, Shenzhen518060, China
| | - Minzhen Zhu
- Research Center for Brain Health, Pazhou Lab, Guangzhou510330, China
| | - Wenchao Xiong
- School of Basic Medical Science, Southern Medical University, Guangzhou510515, China
| | - Huanyu Li
- Research Center for Brain Health, Pazhou Lab, Guangzhou510330, China
| | - Yulu Zhao
- School of Basic Medical Science, Southern Medical University, Guangzhou510515, China
- Research Center for Brain Health, Pazhou Lab, Guangzhou510330, China
| | - Bruce D. Hammock
- Department of Entomology and Nematology, University of California, Davis, CA95616
- University of California Davis Comprehensive Cancer Center, University of California, Davis, CA95616
| | - Xinhong Zhu
- School of Basic Medical Science, Southern Medical University, Guangzhou510515, China
- Research Center for Brain Health, Pazhou Lab, Guangzhou510330, China
- School of Psychology, Shenzhen University, Shenzhen518060, China
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou510006, China
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Mfsd2a attenuated hypoxic-ischemic brain damage via protection of the blood-brain barrier in mfat-1 transgenic mice. Cell Mol Life Sci 2023; 80:71. [PMID: 36820986 PMCID: PMC9950179 DOI: 10.1007/s00018-023-04716-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/10/2023] [Accepted: 02/01/2023] [Indexed: 02/24/2023]
Abstract
Previous studies have shown that mfat-1 transgenic mice have protective effects against some central nervous system (CNS) disorders, owing to the high docosahexaenoic acid (DHA) content enriched in their brains. However, whether this protective effect is connected to the blood-brain barrier (BBB) remains unclear. This study aims to investigate the mechanisms of the protective effect against hypoxic-ischemic brain damage (HIBD) of mfat-1 transgenic mice. mfat-1 mice not only demonstrated a significant amelioration of neurological dysfunction and neuronal damage but also partly maintained the physiological permeability of the BBB after HIBD. We initially showed this was associated with elevated major facilitator superfamily domain-containing 2a (Mfsd2a) expression on the BBB, resulting from more lysophosphatidylcholine (LPC)-DHA entering the brain. Wild-type (WT) mice showed a similar Mfsd2a expression trend after long-term feeding with an LPC-DHA-rich diet. Knockdown of Mfsd2a by siRNA intra-cerebroventricular (ICV) injection neutralized the protective effect against HIBD-induced BBB disruption in mfat-1 mice, further validating the protective function of Mfsd2a on BBB. HIBD-induced BBB high permeability was attenuated by Mfsd2a, primarily through a transcellular pathway to decrease caveolae-like vesicle-mediated transcytosis. Taken together, these findings not only reveal that mfat-1 transgenic mice have higher expression of Mfsd2a on the BBB, which partly sustains BBB permeability via vesicular transcytosis to alleviate the severity of HIBD, but also suggest that dietary intake of LPC-DHA may upregulate Mfsd2a expression as a novel therapeutic strategy for BBB dysfunction and survival in HIBD patients.
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