DHA is one of the most abundant fatty acids in the brain, largely present in stores of membrane phospholipids. It is readily released by the action of phospholipase A2 and is known to induce anti-inflammatory and neurotrophic effects. It is not thought to contribute to proinflammatory processes in the brain. In this study, an immortalized murine microglia cell line (BV-2) was used to evaluate the effect of DHA on neuroinflammatory cells. Pretreatment of BV-2 cells with low concentrations of DHA (30 µM) attenuates lipopolysaccharide-mediated inflammatory cytokine gene expression, consistent with known anti-inflammatory effects. However, higher (but still physiologically relevant) concentrations of DHA (200 µM) induce profound cell swelling and a reduction of viability. This is accompanied by increases in the expressions of inflammatory cytokine and lipoxygenase genes, activation of caspase-1 activity, and release of IL1β, indicating that cells were undergoing a proinflammatory cell death program known as pyroptosis. This process could be attenuated by pharmacological inhibition of 12-lipoxygenase (12-LOX, Alox12e), but not by inhibition of 5-LOX or 15-LOX. Cumulatively, these data demonstrate that DHA has an anti-inflammatory effect on microglial cells, but its metabolism by 12-LOX generates one or more products that activate a proinflammatory cell death program.
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Central nervous system
Damage-associated molecular pattern
Dulbecco’s modified Eagle’s medium
Pattern recognition receptor
Polyunsaturated fatty acid
Specialized pro-resolving mediators
Aiba-Masago, S., Masago, R., Vela-Roch, N., Talal, N., & Dang, H. (2001). Fas-mediated apoptosis in a rat acinar cell line is dependent on caspase-1 activity. Cell Signal, 13(9), 617–624.
Barlow, R. S., & White, R. E. (1998). Hydrogen peroxide relaxes porcine coronary arteries by stimulating BKCa channel activity. American Journal of Physiology, 275(4 Pt 2), H1283–H1289.
Bergsbaken, T., Fink, S. L., & Cookson, B. T. (2009). Pyroptosis: Host cell death and inflammation. Nature Reviews Microbiology, 7(2), 99–109. https://doi.org/10.1038/nrmicro2070.
Blasi, E., Barluzzi, R., Bocchini, V., Mazzolla, R., & Bistoni, F. (1990). Immortalization of murine microglial cells by a v-raf/v-myc carrying retrovirus. Journal of Neuroimmunology, 27(2–3), 229–237.
Calder, P. C. (2010). Omega-3 fatty acids and inflammatory processes. Nutrients, 2(3), 355–374. https://doi.org/10.3390/nu2030355.
Chen, G. Y., & Nunez, G. (2010). Sterile inflammation: Sensing and reacting to damage. Nature Reviews Immunology, 10(12), 826–837. https://doi.org/10.1038/nri2873.
Cookson, B. T., & Brennan, M. A. (2001). Pro-inflammatory programmed cell death. Trends in Microbiology, 9(3), 113–114.
Duvall, M. G., & Levy, B. D. (2016). DHA- and EPA-derived resolvins, protectins, and maresins in airway inflammation. European Journal of Pharmacology, 785, 144–155. https://doi.org/10.1016/j.ejphar.2015.11.001.
Dyall, S. C. (2015). Long-chain omega-3 fatty acids and the brain: A review of the independent and shared effects of EPA, DPA and DHA. Frontiers in Aging Neuroscience, 7, 52. https://doi.org/10.3389/fnagi.2015.00052.
Fann, D. Y., Lee, S. Y., Manzanero, S., Chunduri, P., Sobey, C. G., & Arumugam, T. V. (2013). Pathogenesis of acute stroke and the role of inflammasomes. Ageing Research Reviews, 12(4), 941–966. https://doi.org/10.1016/j.arr.2013.09.004.
Farooqui, A. A., Ong, W. Y., & Horrocks, L. A. (2004). Neuroprotection abilities of cytosolic phospholipase A2 inhibitors in kainic acid-induced neurodegeneration. Current Drug Targets-Cardiovascular & Hematological Disorders, 4(1), 85–96.
Feldman, N., Rotter-Maskowitz, A., & Okun, E. (2015). DAMPs as mediators of sterile inflammation in aging-related pathologies. Ageing Research Reviews, 24(Pt A), 29–39. https://doi.org/10.1016/j.arr.2015.01.003.
Fourrier, C., Remus-Borel, J., Greenhalgh, A. D., Guichardant, M., Bernoud-Hubac, N., Lagarde, M., et al. (2017). Docosahexaenoic acid-containing choline phospholipid modulates LPS-induced neuroinflammation in vivo and in microglia in vitro. Journal of Neuroinflammation, 14(1), 170. https://doi.org/10.1186/s12974-017-0939-x.
Godfrey, J., Jeanguenin, L., Castro, N., Olney, J. J., Dudley, J., Pipkin, J., et al. (2015). Chronic voluntary ethanol consumption induces favorable ceramide profiles in selectively bred alcohol-preferring (P) rats. PLoS ONE, 10(9), e0139012. https://doi.org/10.1371/journal.pone.0139012.
Herr, D. R., Lee, C. W., Wang, W., Ware, A., Rivera, R., & Chun, J. (2013). Sphingosine 1-phosphate receptors are essential mediators of eyelid closure during embryonic development. Journal of Biological Chemistry, 288(41), 29882–29889. https://doi.org/10.1074/jbc.M113.510099.
Herr, D. R., Reolo, M. J., Peh, Y. X., Wang, W., Lee, C. W., Rivera, R., et al. (2016). Sphingosine 1-phosphate receptor 2 (S1P2) attenuates reactive oxygen species formation and inhibits cell death: Implications for otoprotective therapy. Scientific Reports, 6, 24541. https://doi.org/10.1038/srep24541.
Ho, C. F., Bon, C. P., Ng, Y. K., Herr, D. R., Wu, J. S., Lin, T. N., et al. (2018). Expression of DHA-metabolizing enzyme Alox15 is regulated by selective histone acetylation in neuroblastoma cells. Neurochemical Research, 43(3), 540–555. https://doi.org/10.1007/s11064-017-2448-9.
Kim, J., Fann, D. Y., Seet, R. C., Jo, D. G., Mattson, M. P., & Arumugam, T. V. (2016). Phytochemicals in ischemic stroke. Neuromolecular Medicine, 18(3), 283–305. https://doi.org/10.1007/s12017-016-8403-0.
Lamkanfi, M., Kanneganti, T. D., Van Damme, P., Vanden Berghe, T., Vanoverberghe, I., Vandekerckhove, J., et al. (2008). Targeted peptidecentric proteomics reveals caspase-7 as a substrate of the caspase-1 inflammasomes. Molecular & Cellular Proteomics, 7(12), 2350–2363. https://doi.org/10.1074/mcp.M800132-MCP200.
Miao, E. A., Rajan, J. V., & Aderem, A. (2011). Caspase-1-induced pyroptotic cell death. Immunological Reviews, 243(1), 206–214. https://doi.org/10.1111/j.1600-065X.2011.01044.x.
Pizato, N., Luzete, B. C., Kiffer, L., Correa, L. H., de Oliveira Santos, I., Assumpcao, J. A. F., et al. (2018). Omega-3 docosahexaenoic acid induces pyroptosis cell death in triple-negative breast cancer cells. Scientific Reports, 8(1), 1952. https://doi.org/10.1038/s41598-018-20422-0.
Poh, K. W., Yeo, J. F., Stohler, C. S., & Ong, W. Y. (2012). Comprehensive gene expression profiling in the prefrontal cortex links immune activation and neutrophil infiltration to antinociception. Journal of Neuroscience, 32(1), 35–45. https://doi.org/10.1523/JNEUROSCI.2389-11.2012.
Reed, J. C. (2000). Mechanisms of apoptosis. The American Journal of Pathology, 157(5), 1415–1430. https://doi.org/10.1016/S0002-9440(10)64779-7.
Rubartelli, A., Lotze, M. T., Latz, E., & Manfredi, A. (2013). Mechanisms of sterile inflammation. Frontiers in Immunology, 4, 398. https://doi.org/10.3389/fimmu.2013.00398.
Sagulenko, V., Vitak, N., Vajjhala, P. R., Vince, J. E., & Stacey, K. J. (2018). Caspase-1 Is an apical caspase leading to caspase-3 cleavage in the AIM2 inflammasome response, independent of caspase-8. Journal of Molecular Biology, 430(2), 238–247. https://doi.org/10.1016/j.jmb.2017.10.028.
Seki, K., Yoshikawa, H., Shiiki, K., Hamada, Y., Akamatsu, N., & Tasaka, K. (2000). Cisplatin (CDDP) specifically induces apoptosis via sequential activation of caspase-8, -3 and -6 in osteosarcoma. Cancer Chemotherapy and Pharmacology, 45(3), 199–206. https://doi.org/10.1007/s002800050030.
Shalini, S. M., Herr, D. R., & Ong, W. Y. (2017). The analgesic and anxiolytic effect of souvenaid, a novel nutraceutical, is mediated by Alox15 activity in the prefrontal cortex. Molecular Neurobiology, 54(8), 6032–6045. https://doi.org/10.1007/s12035-016-0138-2.
Shalini, S. M., Ho, C. F., Ng, Y. K., Tong, J. X., Ong, E. S., Herr, D. R., et al. (2018). Distribution of Alox15 in the rat brain and its role in prefrontal cortical resolvin D1 formation and spatial working memory. Molecular Neurobiology, 55(2), 1537–1550. https://doi.org/10.1007/s12035-017-0413-x.
Shinohara, M., Mirakaj, V., & Serhan, C. N. (2012). Functional metabolomics reveals novel active products in the DHA metabolome. Frontiers in Immunology, 3, 81. https://doi.org/10.3389/fimmu.2012.00081.
Tatsuta, T., Shiraishi, A., & Mountz, J. D. (2000). The prodomain of caspase-1 enhances Fas-mediated apoptosis through facilitation of caspase-8 activation. Journal of Biological Chemistry, 275(19), 14248–14254.
Thirunavukkarasan, M., Wang, C., Rao, A., Hind, T., Teo, Y. R., Siddiquee, A. A., et al. (2017). Short-chain fatty acid receptors inhibit invasive phenotypes in breast cancer cells. PLoS ONE, 12(10), e0186334. https://doi.org/10.1371/journal.pone.0186334.
The authors are grateful to Low Kay En and the Electron Microscopy Unit at the National University of Singapore for expert technical assistance with the scanning electron microscopy, and to Pabba Anubharath for expert technical assistance with the processing of time-lapse microscopy data. This work was supported by the Ministry of Education, Singapore (T1-2016 Sep-11, D.R.H.); the National Medical Research Council, Singapore (NMRC/CIRG/1410/2014, W.Y.O.); and the National University Health System (NUHSRO/2014/085/AF-Partner/01, D.R.H.).
Conflict of interest
The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.
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Srikanth, M., Chandrasaharan, K., Zhao, X. et al. Metabolism of Docosahexaenoic Acid (DHA) Induces Pyroptosis in BV-2 Microglial Cells. Neuromol Med 20, 504–514 (2018). https://doi.org/10.1007/s12017-018-8511-0
- Docosahexaenoic acid (DHA)