Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, Salt Lake City, UT 84132.
Department of Chemistry, University of Utah, Salt Lake City, UT 84112.
Proc Natl Acad Sci U S A. 2021 Feb 9;118(6). doi: 10.1073/pnas.2017739118.
Rare, nondietary very-long-chain polyunsaturated fatty acids (VLC-PUFAs) are uniquely found in the retina and a few other vertebrate tissues. These special fatty acids play a clinically significant role in retinal degeneration and development, but their physiological and interventional research has been hampered because pure VLC-PUFAs are scarce. We hypothesize that if Stargardt-3 or age-related macular degeneration patients were to consume an adequate amount of VLC-PUFAs that could be directly used in the retina, it may be possible to bypass the steps of lipid elongation mediated by the retina's ELOVL4 enzyme and to delay or prevent degeneration. We report the synthesis of a VLC-PUFA (32:6 n-3) in sufficient quantity to study its bioavailability and functional benefits in the mouse retina. We acutely and chronically gavage fed wild-type mice and rod-cone conditional knockout mice this synthetic VLC-PUFA to understand its bioavailability and its role in visual function. VLC-PUFA-fed wild-type and conditional knockout mice show a significant increase in retinal VLC-PUFA levels in comparison to controls. The VLC-PUFA-fed mice also had improvement in the animals' visual acuity and electroretinography measurements. Further studies with synthetic VLC-PUFAs will continue to expand our understanding of the physiological roles of these unique retinal lipids, particularly with respect to their potential utility for the treatment and prevention of retinal degenerative diseases.
罕见的、非饮食来源的超长链多不饱和脂肪酸(VLC-PUFAs)仅存在于视网膜和一些其他脊椎动物组织中。这些特殊的脂肪酸在视网膜变性和发育中具有重要的临床意义,但由于纯 VLC-PUFAs 稀缺,其生理和干预研究受到了阻碍。我们假设,如果 Stargardt 3 或年龄相关性黄斑变性患者摄入足够数量的可直接用于视网膜的 VLC-PUFAs,那么有可能绕过视网膜 ELOVL4 酶介导的脂质延长步骤,并延迟或预防变性。我们报告了一种 VLC-PUFA(32:6 n-3)的合成,其数量足以研究其在小鼠视网膜中的生物利用度和功能益处。我们急性和慢性灌胃给予野生型和视杆-视锥条件性敲除小鼠这种合成的 VLC-PUFA,以了解其生物利用度及其在视觉功能中的作用。与对照组相比,VLC-PUFA 喂养的野生型和条件性敲除小鼠的视网膜 VLC-PUFA 水平显著增加。VLC-PUFA 喂养的小鼠的动物视力和视网膜电图测量也有所改善。进一步的合成 VLC-PUFA 研究将继续扩展我们对这些独特的视网膜脂质的生理作用的理解,特别是它们在治疗和预防视网膜退行性疾病方面的潜在应用。