Lysophosphatidylcholine

Overview

Lysophosphatidylcholines are produced within cells mainly by the enzyme phospholipase A2, which removes one of the fatty acid groups from phosphatidylcholine to produce LPC. Among other properties, they activate endothelial cells during early atherosclerosis. LPC also acts as a find-me signal, released by apoptotic cells to recruit phagocytes, which then phagocytose the apoptotic cells. Moreover, LPCs can be used in the lab to cause demyelination of brain slices and to mimic the effects of demyelinating diseases such as multiple sclerosis. LPCs are also known to stimulate phagocytosis of the myelin sheath and can change the surface properties of erythrocytes. LPC-induced demyelination is thought to occur through the actions of recruited macrophages and microglia which phagocytose nearby myelin. Invading T cells are also thought to mediate this process. Bacteria such as Legionella pneumophila utilize phospholipase A2 end-products (fatty acids and lysophospholipids) to cause host cell (macrophage) apoptosis through cytochrome C release.

LPCs are present as minor phospholipids in the cell membrane (≤ 3%) and in the blood plasma (8–12%). Lysophosphatidylcholine processing has been discovered to be an essential component of normal human brain development: those born with genes that prevent adequate uptake suffer from lethal microcephaly. MFSD2a has been shown to transport LPC-bound polyunsaturated fatty acids, including DHA and EPA, across the blood-brain and blood-retinal barriers.

LPCs occur in many foods naturally. According to the third edition of Starch: Chemistry and Technology, lysophosphatidylcholine makes up about 70% of the lipids in oat starch (p.592).

Also, the anti-cancer abilities of synthetic LPC variants are special since they do not target the cell DNA but rather insert into the plasma membrane, causing apoptosis through the influencing of several signal pathways. Therefore, their effects are independent of the proliferation state of the tumor cell.

Industrial applications of PLA2

FoodPro LysoMaxa Oil is an FDA approved commercialized PLA2 enzyme preparation utilized for the degumming of vegetable oils in large-scale productions to increase yield. Variants of lysophosphatidylcholine are the main products of this enzyme.

Applications

Lysophosphatidylcholine has been studied as an immune activator for differentiating monocytes to mature dendritic cells. Lysophosphatidylcholine present in blood amplifies microbial TLR ligands-induced inflammatory responses from human cells like intestinal epithelial cells and macrophages/monocytes. This has an implication in sepsis induced by microbes.

Occurrence in foods

Lysophosphatidylcholine accounts for 4.6% of phospholipids found in coconut oil, which make up 0.2% of lipids in coconut oil. In contrast, vegetable oils contain about 2-3% phospholipids.

Production in atherosclerosis

Intima-media thickness, which is positively correlated with reduced blood flow, was studied in young smokers. Evidence pointed towards smoking as a major risk factor for increased levels of PLA2, due to tobacco smoke's impact on oxidation of retained LDL particles in the intima of a carotid artery, which may have a detrimental impact on overall health.

References

References

1. (May 2018). "Lysophospholipids induce innate immune transdifferentiation of endothelial cells, resulting in prolonged endothelial activation.". The Journal of Biological Chemistry.
2. [http://www.lipidlibrary.co.uk/Lipids/pc/index.htm Phosphatidylcholine and related lipids] {{webarchive. link. (2009-05-31 , lipidlibrary.co.uk)
3. (April 2016). "Mitochondrial Reactive Oxygen Species Mediate Lysophosphatidylcholine-Induced Endothelial Cell Activation". Arteriosclerosis, Thrombosis, and Vascular Biology.
4. (March 2018). "IL-35 (Interleukin-35) Suppresses Endothelial Cell Activation by Inhibiting Mitochondrial Reactive Oxygen Species-Mediated Site-Specific Acetylation of H3K14 (Histone 3 Lysine 14).". Arteriosclerosis, Thrombosis, and Vascular Biology.
5. Lauber, K. (2003). "Apoptotic Cells Induce Migration of Phagocytes via Caspase-3-Mediated Release of a Lipid Attraction Signal". Cell.
6. Munder, PG. (1979). "Lysophosphatidylcholine (Lysolecithin) and its Synthetic Analogues. Immunemodulating and Other Biologic Effects". Springer Seminars in Immunopathology.
7. Houlihan, W. (1995). "Phospholipid antitumor agents.". Medicinal Research Reviews.
8. Guemez-Gamboa, Alicia. (2015). "Inactivating mutations in MFSD2A, required for omega-3 fatty acid transport in brain, cause a lethal microcephaly syndrome.". Nature Genetics.
9. (2014-05-22). "Mfsd2a is a transporter for the essential omega-3 fatty acid docosahexaenoic acid". Nature.
10. (2016). "Mfsd2a Is a Transporter for the Essential ω-3 Fatty Acid Docosahexaenoic Acid (DHA) in Eye and Is Important for Photoreceptor Cell Development". J Biol Chem.
11. (2009-04-06). "Starch". Academic Press.
12. van Blitterswijk, W. (2008). "Anticancer alkylphospholipids: mechanisms of action, cellular sensitivity and resistance, and clinical prospects.". Current Pharmaceutical Design.
13. (2012-10-08). "Biochemistry of Foods". Academic Press.
14. "Patent US20110135684 - Use of L-alpha-lysophosphatidylcholine to obtain the differentiation of...". google.com.mx.
15. (2020). "Serum-borne lipids amplify TLR-activated inflammatory responses". Journal of Leukocyte Biology.
16. "Rahman's page 12 chart".
17. (2013). "Lysophosphatidylcholine and Carotid Intima-Media Thickness in Young Smokers: A Role for Oxidized LDL-Induced Expression of PBMC Lipoprotein-Associated Phospholipase A2?". PLOS ONE.