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. 2022 Jul 22:13:932383.
doi: 10.3389/fimmu.2022.932383. eCollection 2022.

Natural fish oil improves the differentiation and maturation of oligodendrocyte precursor cells to oligodendrocytes in vitro after interaction with the blood-brain barrier

Paweł Piatek  1 , Natalia Lewkowicz  2 , Sylwia Michlewska  3 , Marek Wieczorek  4 , Radosław Bonikowski  5 , Karol Parchem  6 , Przemysław Lewkowicz  1 , Magdalena Namiecinska  1
Affiliations

Natural fish oil improves the differentiation and maturation of oligodendrocyte precursor cells to oligodendrocytes in vitro after interaction with the blood-brain barrier

Paweł Piatek et al. Front Immunol. .

Abstract

The blood-brain barrier (BBB) tightly controls the microenvironment of the central nervous system (CNS) to allow neurons to function properly. Additionally, emerging studies point to the beneficial effect of natural oils affecting a wide variety of physiological and pathological processes in the human body. In this study, using an in vitro model of the BBB, we tested the influence of natural fish oil mixture (FOM) vs. borage oil (BO), both rich in long-chain polyunsaturated fatty acids (LC-PUFAs) and monounsaturated fatty acids (MUFAs) such as oleic acid (C18:1n9c) or nervonic acid (NA), on human oligodendrocyte precursor cells (hOPCs) during their maturation to oligodendrocytes (OLs) regarding their ability to synthesize myelin peptides and NA. We demonstrated that FOM, opposite to BO, supplemented endothelial cells (ECs) and astrocytes forming the BBB, affecting the function of hOPCs during their maturation. This resulted in improved synthesis of myelin basic protein (MBP), myelin oligodendrocyte glycoprotein (MOG), proteolipid protein (PLP), and NA in mature OLs. This effect is probably the result of BBB cell and hOPC stimulation via free fatty acid receptors (FFARs), which increases insulin growth factor-1 (IGF-1), ciliary neurotrophic factor (CNTF), and brain-derived neurotrophic factor (BDNF) and inhibits fibroblast growth factor 2 (FGF-2) synthesis. The unique formula of fish oil, characterized by much more varied components compared to those of BOs, also improved the enhancement of the tight junction by increasing the expression of claudin-5 and VE-cadherin on ECs. The obtained data justify consideration of naturally derived fish oil intake in human diet as affecting during remyelination.

Keywords: Blood-brain barrier; astrocytes; endothelial cells; long-chain fatty acids; oligodendrocyte precursor cells; oligodendrocytes; remyelinating therapy.

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Conflict of interest statement

The authors declare a conflict of interest. This work was supported by funds obtained from the cooperation between Medical University of Lodz with The Marinex International Company (contract No. CRU: 0121-CSTT-2020). The Marinex International Company had no role in the design, execution, interpretation, and writing the manuscript.

Figures

Figure 1
Figure 1
Quantitative analysis of the mRNA expression of myelin peptides revealed that hOPCs supplemented with fish oil mixture (FOM) contrary to borage oil (BO) during maturation results in enhanced transcription of MOG, PLP, and MBP in mature OLs. This synthesis was further improved by the use of the blood–brain barrier (BBB). (A) Diagram of the experiment performed to characterize the role of the BBB exposed to FOM or BO and their effect on OPC differentiation into mature MBP/PLP/MOG-producing OLs. (B) The quantitative mRNA analysis of MBP, MOG, and PLP expressed by hOPCs and OLs. The results were expressed as the number of gene copies per 20 μl of samples. The graph presented the means ± SD from three independent experiments. The differences between medium/BO/FOM were calculated using the one-way ANOVA test and Scheffe’s test. The differences in the adequate groups between “direct exposition” and “BBB model” were calculated using the paired t-test.
Figure 2
Figure 2
The supplementation of BBB cells by FOM, opposite to BO, during hOPC maturation enhanced MOG, PLP, and MBP synthesis by mature OLs. The use of the BBB increased the ability of mature OLs to synthesize myelin peptides compared to direct exposition of hOPCs to FOM during their maturation. (A, left panel) Diagram of the experiment performed to characterize the role of the BBB exposed to FOM or BO and their effect on OPC differentiation into mature MBP/PLP/MOG-producing OLs. (A, right panel) The ICC analysis of MOG (green pseudocolor) and MBP (red). (B) PLP immunocytochemical analysis. The data from the quantitative fluorescence signal of protein analysis are presented as the relative mean fluorescence intensity [arbitral units (a.u.)] ± SD from three independent experiments using at least 100 single cells for each test. The differences between medium/BO/FOM were calculated using the one-way ANOVA test and Scheffe’s test. The differences in the adequate groups between “direct exposition” and “BBB model” were calculated using the paired t-test.
Figure 3
Figure 3
The supplementation of BBB cells by FOM during polarization of hOPCs to mature OLs resulted in the stimulation of IGF-1, BDNF, and CNTF but decreased FGF-2 synthesis. (A) The concentration of IGF-1, BDNF, CNTF, and FGF-2 in supernatants of the BBB construct with OLs. BBB cells were conditioned by FOM or BO. (B) The analysis of FOM and BO effect on individual cell subpopulations: endothelial cells, astrocytes, hOPCs, and OLs. The graph presented the means ± SD from three independent experiments. The differences between BO and FOM supplementation vs. adequate group in medium were calculated using the paired t-test.
Figure 4
Figure 4
OPCs and mature OLs, contrary to BBB cells, are characterized by a high expression of FFAR4, receptors for long-chain saturated and unsaturated FA. In turn, a high expression of FFAR3, receptors recognized for short-chain fatty acids, is observed on astrocytes (Ast.). (A) The ICC analysis of FFAR2 (green pseudocolor) and FFAR4 (red) expression on separated cell cultures of ECs, Ast., hOPCs, and mature OLs. (B) ICC double-labeling of FFAR1 (green pseudocolor) and FFAR3 (red) on ECs, Ast., OPCs, and OLs. The bars represent average fluorescence intensity ± SD calculated from three independent experiments using at least 100 single cells for each test. The differences between different cell populations were calculated using the one-way ANOVA test and Scheffe’s test.
Figure 5
Figure 5
BBB cells supplemented with FOM enhanced NA synthesis by mature OLs. (A) The division into substrates: C16:0, C18:0 vs. products: C18:1n9c, C20:1n9; C22:1n9, C24:1n9 was set arbitrary based on the starting enzyme Δ9 desaturase, creating a carbon(C9)/carbon(C10) double bond. (B) BBB cells initiate lipid metabolism to NA synthesis. The distribution of substrates and products involved in NA synthesis by OPCs and OLs is presented as the percentage of all lipids and as NA pathway index. Data are presented as the mean calculated from three independent experiments. (C) The effect of BBB supplementation with FOM and BO on the NA pathway is presented as the percentage of decreasing substrates vs. product increment. Data are presented as the mean calculated from three independent experiments.
Figure 6
Figure 6
BBB cells supplemented with FOM increased claudin-5 (CLDN-5) and VE-cadherin (VEC) expression on endothelial cells (ECs), enhancing tight junction. ICC double-labeling for CLDN-5 (green pseudocolor) and VEC (red) on ECs with/without exposition to FOM and BO. ICC staining was performed after the membrane was cut from the Transwell inserts. The bars represent average fluorescence intensity ± SD calculated from three independent experiments using at least 100 single cells for each test. The differences between differently conditioned cells were calculated using the one-way ANOVA test and Scheffe’s test.
Figure 7
Figure 7
The comparative analysis of lipid species in FOM vs. BO by RP-LC-Q-Orbitrap HRMS technique displayed significantly more compounds in FOM compared to BO, despite similar percentages of all TG, DG, and MG in both oils. (A) The number and percentage of the lipid species divided into main lipid categories: MG, monoacylglycerol; DG, diacylglycerol; TG, triacylglycerol. (B) Retention time (RT) vs. mass-to-charge ratio (m/z) plots for lipid species identified in FOM and BO using RP-LC-Q-Orbitrap HRMS.
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References

    1. Almutairi MM, Gong C, Xu YG, Chang Y, Shi H. Factors controlling permeability of the blood-brain barrier. Cell Mol Life Sci (2016) 73:57–77. doi: 10.1007/s00018-015-2050-8 - DOI - PMC - PubMed
    1. Luissint AC, Artus C, Glacial F, Ganeshamoorthy K, Couraud PO. Tight junctions at the blood brain barrier: Physiological architecture and disease-associated dysregulation. Fluids Barriers CNS (2012) 9:23. doi: 10.1186/2045-8118-9-23 - DOI - PMC - PubMed
    1. Li SQ, Lin YN, Li QY. Soluble VE-cadherin: not just a marker of endothelial permeability. Eur Respir J (2021) 58(6):2102241. doi: 10.1183/13993003.02241-2021 - DOI - PubMed
    1. Lotun A, Gessler DJ, Gao G. Canavan disease as a model for gene therapy-mediated myelin repair. Front Cell Neurosci (2021) 15:661928. doi: 10.3389/fncel.2021.661928 - DOI - PMC - PubMed
    1. Gómez-Pinedo U, Duran-Moreno M, Sirerol-Piquer S, Matias-Guiu J. Myelin changes in Alexander disease. Neurol (Engl Ed) (2018) 33(8):526–33. doi: 10.1016/j.nrl.2017.01.019 - DOI - PubMed

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