Changes in Lipid Profiles with the Progression of Pregnancy in Black Women.

Background/Objectives: Lipid metabolism plays an important role in maternal health and fetal development. There is a gap in the knowledge of how lipid metabolism changes during pregnancy for Black women who are at a higher risk of adverse outcomes. We hypothesized that the comprehensive lipidome profiles would show variation across pregnancy indicative of requirements during gestation and fetal development. Methods: Black women were recruited at prenatal clinics. Plasma samples were collected at 8-18 weeks (T1), 22-29 weeks (T2), and 30-36 weeks (T3) of pregnancy. Samples from 64 women who had term births (≥37 weeks gestation) were subjected to "shotgun" Orbitrap mass spectrometry. Mixed-effects models were used to quantify systematic changes and dimensionality reduction models were used to visualize patterns and identify reliable lipid signatures. Results: Total lipids and major lipid classes showed significant increases with the progression of pregnancy. Phospholipids and glycerolipids exhibited a gradual increase from T1 to T2 to T3, while sphingolipids and total sterol lipids displayed a more pronounced increase from T2 to T3. Acylcarnitines, hydroxy acylcarnitines, and Lyso phospholipid levels significantly decreased from T1 to T3. A deviation was that non-esterified fatty acids decreased from T1 to T2 and increased again from T2 to T3, suggestive of a potential role for these lipids during the later stages of pregnancy. The fatty acids showing this trend included key fatty acids-non-esterified Linoleic acid, Arachidonic acid, Alpha-linolenic acid, Eicosapentaenoic acid, Docosapentaenoic acid, and Docosahexaenoic acid. Conclusions: Mapping lipid patterns and identifying lipid signatures would help develop intervention strategies to reduce perinatal health disparities among pregnant Black women.

Untargeted Analysis of Lipids Containing Very Long Chain Fatty Acids in Retina and Retinal Tight Junctions.

Several recent studies suggest that C24-C38 very long chain fatty acids (VLCFA) play an important role in vision, and decreased levels of retina VLCFA have been associated with vision disorders including the onset and progression of diabetic retinopathy in animal models. Traditional methods for VLCFA analysis lack the sensitivity and specificity needed to enable detailed characterization of VLCFA incorporation into complex lipids in tissues and subcellular components. To assess whether decreased VLCFA in diabetic retina are directly implicated in diabetes-induced breakdown of the blood-retinal barrier, we demonstrated the utility of performing untargeted lipid analysis via Orbitrap high resolution/accurate mass MS and MS/MS-based shotgun lipidomics to identify structural lipids containing VLCFA substituents. This comprehensive and highly sensitive approach to untargeted lipid identification enabled us to characterize low-abundance sphingolipids containing very long chain fatty acids from isolated retinal tight junction complexes, as well as VLCFA-containing phospholipids in retinal tissues. To facilitate future biochemical and physiological studies of the roles of VLCFA in blood-retina barrier integrity and maintenance of vision, this chapter describes steps to isolate tight junction complexes from a cell culture model of the outer blood-retinal barrier and perform untargeted Orbitrap high resolution/accurate mass-based lipid analysis to identify VLCFA in tight junctions and retina tissue.

Dietary fish oil enriched in very-long-chain polyunsaturated fatty acid reduces cardiometabolic risk factors and improves retinal function.

Very-long-chain polyunsaturated fatty acids (VLCPUFAs; C24-38) constitute a unique class of PUFA that have important biological roles, but the lack of a suitable dietary source has limited research in this field. We produced an n-3 C24-28-rich VLCPUFA-oil concentrated from fish oil to study its bioavailability and physiological functions in C57BL/6J mice. The serum and retinal C24:5 levels increased significantly compared to control after a single-dose gavage, and VLCPUFAs were incorporated into the liver, brain, and eyes after 8-week supplementation. Dietary VLCPUFAs resulted in favorable cardiometabolic changes, and improved electroretinography responses and visual performance. VLCPUFA supplementation changed the expression of genes involved in PPAR signaling pathways. Further in vitro studies demonstrated that the VLCPUFA-oil and chemically synthesized C24:5 are potent agonists for PPARs. The multiple potential beneficial effects of fish oil-derived VLCPUFAs on cardiometabolic risk and eye health in mice support future efforts to develop VLCPUFA-oil into a supplemental therapy.