FABP7 Protects Astrocytes Against ROS Toxicity via Lipid Droplet Formation

  • Ariful IslamEmail author
  • Yoshiteru Kagawa
  • Hirofumi Miyazaki
  • Subrata Kumar Shil
  • Banlanjo A. Umaru
  • Yuki Yasumoto
  • Yui Yamamoto
  • Yuji OwadaEmail author


Fatty acid-binding proteins (FABPs) bind and internalize long-chain fatty acids, controlling lipid dynamics. Recent studies have proposed the involvement of FABPs, particularly FABP7, in lipid droplet (LD) formation in glioma, but the physiological significance of LDs is poorly understood. In this study, we sought to examine the role of FABP7 in primary mouse astrocytes, focusing on its protective effect against reactive oxygen species (ROS) stress. In FABP7 knockout (KO) astrocytes, ROS induction significantly decreased LD accumulation, elevated ROS toxicity, and impaired thioredoxin (TRX) but not peroxiredoxin 1 (PRX1) signalling compared to ROS induction in wild-type astrocytes. Consequently, activation of apoptosis signalling molecules, including p38 mitogen-activated protein kinase (MAPK) and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and increased expression of cleaved caspase 3 were observed in FABP7 KO astrocytes under ROS stress. N-acetyl L-cysteine (NAC) application successfully rescued the ROS toxicity in FABP7 KO astrocytes. Furthermore, FABP7 overexpression in U87 human glioma cell line revealed higher LD accumulation and higher antioxidant defence enzyme (TRX, TRX reductase 1 [TRXRD1]) expression than mock transfection and protected against apoptosis signalling (p38 MAPK, SAPK/JNK and cleaved caspase 3) activation. Taken together, these data suggest that FABP7 protects astrocytes from ROS toxicity through LD formation, providing new insights linking FABP7, lipid homeostasis, and neuropsychiatric/neurodegenerative disorders, including Alzheimer’s disease and schizophrenia.


Fatty acid-binding protein 7 Astrocytes Lipid droplet Thioredoxin U87 



This research was supported mainly by grants from JSPS KAKENHI (16H05116 and 18K19723 to Y.O.) and in part by grants from the Project of Translational and Clinical Research Core Centers from AMED (grant no. JP17dm0107071) of Japan and the Tokyo Biochemical Research Foundation to Y.O.

Compliance with Ethical Standards

All experimental procedures involving mice were approved by the Institute of Laboratory Animals of Tohoku University Graduate School of Medicine and carried out according to the Guidelines for Animal Experimentation of the Tohoku University Graduate School of Medicine and according to the laws and notification requirements of Japanese governments.

Conflict of Interest

The authors declare that they have no conflict of interest.

Supplementary material

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Fig. S1

Expression of FABP7 in astrocytes. (a) Localization of FABP7 in astrocytes. Scale bar 5 μm. (b) FABP7 protein expression level in normoxic WT astrocytes. (PNG 333 kb)

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Fig. S2

Expression of FABP5 and FABP7 in astrocytes under ROS stress. Expression of FABP5, FABP7 and HIF-1α (indicator of hypoxia induction) proteins detected by western blotting. (PNG 2531 kb)

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Fig. S3

Effect of ROS stress on astrocyte cell morphology. Morphology of primary astrocytes after confluency and maintained in conditioned medium (either in glucose or glucose-deprived medium) for 3 days in (a) normoxic (20% O2) and (b) hypoxic (1% O2) conditions. Scale bar 100 μm. (PNG 260 kb)

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Fig. S4

ROS generation under ROS stress in FABP7 KO astrocytes. (a) Mitochondrial ROS production was detected using MitoSox red staining (red) of live astrocytes under ROS stress, while MitoTracker (green) was used as a mitochondrial marker. The nucleus was counterstained with Hoechst 33342, and the cells were washed and mounted to be microphotographed under a fluorescence microscope. (b) Mitochondrial ROS production from astrocytes measured with MitoSox (mitochondrial superoxide indicator) after 24, 48 and 72 h of incubation with conditioned medium. The fluorescence was measured at Ex510 nm and Em580 nm. The data presented are the mean ± SEM of triplicate experiments using astrocytes derived from different mouse brain specimens. *p < 0.05 versus the respective WT control. The data are presented here as % change over the WT control. (PNG 1634 kb)

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Fig. S5

(a) FABP7 overexpression may rescue U87 cells from higher ROS generation. (b) NAC incubation may improve the higher ROS generation in mock control cells. (PNG 233 kb)

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  1. 1.
    Chung WS, Allen NJ, Eroglu C (2015) Astrocytes control synapse formation, function, and elimination. Cold Spring Harb Perspect Biol 7(9):a020370. PubMedPubMedCentralCrossRefGoogle Scholar
  2. 2.
    Kimelberg HK (2004) The problem of astrocyte identity. Neurochem Int 45(2–3):191–202. PubMedCrossRefGoogle Scholar
  3. 3.
    Christopherson KS, Ullian EM, Stokes CC et al (2005) Thrombospondins are astrocyte-secreted proteins that promote CNS synaptogenesis. Cell 120(3):421–433. PubMedCrossRefGoogle Scholar
  4. 4.
    Mamczur P, Borsuk B, Paszko J et al (2015) Astrocyte-neuron crosstalk regulates the expression and subcellular localization of carbohydrate metabolism enzymes. Glia 63(2):328–340. PubMedCrossRefGoogle Scholar
  5. 5.
    Mauch DH, Nagler K, Schumacher S et al (2001) CNS synaptogenesis promoted by glia-derived cholesterol. Science 294(5545):1354–1357. PubMedCrossRefGoogle Scholar
  6. 6.
    Nishida H, Okabe S (2007) Direct astrocytic contacts regulate local maturation of dendritic spines. J Neurosci 27(2):331–340. PubMedCrossRefGoogle Scholar
  7. 7.
    Camargo N, Goudriaan A, van Deijk AF et al (2017) Oligodendroglial myelination requires astrocyte-derived lipids. PLoS Biol 15(5):e1002605. PubMedPubMedCentralCrossRefGoogle Scholar
  8. 8.
    Adachi Y, Hiramatsu S, Tokuda N et al (2012) Fatty acid-binding protein 4 (FABP4) and FABP5 modulate cytokine production in the mouse thymic epithelial cells. Histochem Cell Biol 138(3):397–406. PubMedCrossRefGoogle Scholar
  9. 9.
    Islam A, Kagawa Y, Sharifi K et al (2014) Fatty acid binding protein 3 is involved in n-3 and n-6 PUFA transport in mouse trophoblasts. J Nutr 144(10):1509–1516. PubMedCrossRefGoogle Scholar
  10. 10.
    Islam A, Owada Y (2015) Fatty acid binding protein 3 (FABP3) deficiency does not impact on feto-placental morphometry and fatty acid transporters in mice. Biores Comm 1(2):57–61Google Scholar
  11. 11.
    Miyazaki H, Sawada T, Kiyohira M et al (2014) Fatty acid binding protein 7 regulates phagocytosis and cytokine production in Kupffer cells during liver injury. Am J Pathol 184(9):2505–2515. PubMedCrossRefGoogle Scholar
  12. 12.
    Sharifi K, Morihiro Y, Maekawa M et al (2011) FABP7 expression in normal and stab-injured brain cortex and its role in astrocyte proliferation. Histochem Cell Biol 136(5):501–513. PubMedPubMedCentralCrossRefGoogle Scholar
  13. 13.
    Sharifi K, Ebrahimi M, Kagawa Y et al (2013) Differential expression and regulatory roles of FABP5 and FABP7 in oligodendrocyte lineage cells. Cell Tissue Res 354(3):683–695. PubMedCrossRefGoogle Scholar
  14. 14.
    Owada Y, Abdelwahab SA, Kitanaka N et al (2006) Altered emotional behavioral responses in mice lacking brain-type fatty acid-binding protein gene. Eur J Neurosci 24(1):175–187. PubMedCrossRefGoogle Scholar
  15. 15.
    Chmurzynska A (2006) The multigene family of fatty acid-binding proteins (FABPs): function, structure and polymorphism. J Appl Genet 47(1):39–48. PubMedCrossRefGoogle Scholar
  16. 16.
    Ratti S, Follo MY, Ramazzotti G et al (2018) Nuclear phospholipase c isoenzyme imbalance leads to pathologies in brain, hematologic, neuromuscular and fertility disorders. J Lipid Res:jlr. R089763.
  17. 17.
    Owada Y, Yoshimoto T, Kondo H (1996) Spatio-temporally differential expression of genes for three members of fatty acid binding proteins in developing and mature rat brains. J Chem Neuroanat 12(2):113–122PubMedCrossRefGoogle Scholar
  18. 18.
    Matsumata M, Sakayori N, Maekawa M et al (2012) The effects of FABP7 and FABP5 on postnatal hippocampal neurogenesis in the mouse. Stem Cells 30(7):1532–1543. PubMedCrossRefGoogle Scholar
  19. 19.
    Arai Y, Funatsu N, Numayama-Tsuruta K et al (2005) Role of Fabp7, a downstream gene of Pax6, in the maintenance of neuroepithelial cells during early embryonic development of the rat cortex. J Neurosci 25(42):9752–9761. PubMedCrossRefGoogle Scholar
  20. 20.
    Watanabe A, Toyota T, Owada Y et al (2007) Fabp7 maps to a quantitative trait locus for a schizophrenia endophenotype. PLoS Biol 5(11):e297. PubMedPubMedCentralCrossRefGoogle Scholar
  21. 21.
    Kipp M, Gingele S, Pott F et al (2011) BLBP-expression in astrocytes during experimental demyelination and in human multiple sclerosis lesions. Brain Behav Immun 25(8):1554–1568. PubMedCrossRefGoogle Scholar
  22. 22.
    Maekawa M, Iwayama Y, Arai R et al (2010) Polymorphism screening of brain-expressed FABP7, 5 and 3 genes and association studies in autism and schizophrenia in Japanese subjects. J Hum Genet 55(2):127–130. PubMedCrossRefGoogle Scholar
  23. 23.
    Kagawa Y, Yasumoto Y, Sharifi K et al (2015) Fatty acid-binding protein 7 regulates function of caveolae in astrocytes through expression of caveolin-1. Glia 63(5):780–794. PubMedCrossRefGoogle Scholar
  24. 24.
    Ebrahimi M, Yamamoto Y, Sharifi K et al (2016) Astrocyte-expressed FABP7 regulates dendritic morphology and excitatory synaptic function of cortical neurons. Glia 64(1):48–62. PubMedCrossRefGoogle Scholar
  25. 25.
    Ebrahimi M, Sharifi K, Islam A et al (2015) Proteomic differential display analysis reveals decreased expression of PEA-15 and vimentin in FABP7-deficient astrocytes. J Proteomics Bioinform 8:009–014Google Scholar
  26. 26.
    Yasumoto Y, Miyazaki H, Ogata M et al (2018) Glial fatty acid-binding protein 7 (FABP7) regulates neuronal leptin sensitivity in the hypothalamic arcuate nucleus. Mol Neurobiol.
  27. 27.
    Fujimoto T, Parton RG (2011) Not just fat: the structure and function of the lipid droplet. Cold Spring Harb Perspect Biol 3(3):a004838PubMedPubMedCentralCrossRefGoogle Scholar
  28. 28.
    Bensaad K, Favaro E, Lewis CA et al (2014) Fatty acid uptake and lipid storage induced by hif-1alpha contribute to cell growth and survival after hypoxia-reoxygenation. Cell Rep 9(1):349–365. PubMedCrossRefGoogle Scholar
  29. 29.
    Scifres CM, Chen B, Nelson DM et al (2011) Fatty acid binding protein 4 regulates intracellular lipid accumulation in human trophoblasts. J Clin Endocrinol Metab 96(7):E1083–E1091. PubMedPubMedCentralCrossRefGoogle Scholar
  30. 30.
    Lucken-Ardjomande Hasler S, Vallis Y, Jolin HE et al (2014) Graf1a is a brain-specific protein that promotes lipid droplet clustering and growth, and is enriched at lipid droplet junctions. J Cell Sci 127(Pt 21):4602–4619. PubMedPubMedCentralCrossRefGoogle Scholar
  31. 31.
    Liu L, MacKenzie KR, Putluri N et al (2017) The glia-neuron lactate shuttle and elevated ros promote lipid synthesis in neurons and lipid droplet accumulation in glia via apoe/d. Cell Metab 26(5):719–737.e716. PubMedPubMedCentralCrossRefGoogle Scholar
  32. 32.
    Shimamoto C, Ohnishi T, Maekawa M et al (2014) Functional characterization of FABP3, 5 and 7 gene variants identified in schizophrenia and autism spectrum disorder and mouse behavioral studies. Hum Mol Genet 23(24):6495–6511. PubMedPubMedCentralCrossRefGoogle Scholar
  33. 33.
    Guo X, Namekata K, Kimura A et al (2017) Ask1 in neurodegeneration. Adv Biol Regul 66:63–71. PubMedCrossRefGoogle Scholar
  34. 34.
    Ishii T, Takanashi Y, Sugita K et al (2017) Endogenous reactive oxygen species cause astrocyte defects and neuronal dysfunctions in the hippocampus: a new model for aging brain. Aging Cell 16(1):39–51. PubMedCrossRefGoogle Scholar
  35. 35.
    Bondarenko A, Chesler M (2001) Rapid astrocyte death induced by transient hypoxia, acidosis, and extracellular ion shifts. Glia 34(2):134–142PubMedCrossRefGoogle Scholar
  36. 36.
    Abdelwahab SA, Owada Y, Kitanaka N et al (2003) Localization of brain-type fatty acid-binding protein in Kupffer cells of mice and its transient decrease in response to lipopolysaccharide. Histochem Cell Biol 119(6):469–475. PubMedCrossRefGoogle Scholar
  37. 37.
    Owada Y, Abdelwahab SA, Suzuki R et al (2001) Localization of epidermal-type fatty acid binding protein in alveolar macrophages and some alveolar type ii epithelial cells in mouse lung. Histochem J 33(8):453–457PubMedCrossRefGoogle Scholar
  38. 38.
    Sheng WS, Hu S, Feng A et al (2013) Reactive oxygen species from human astrocytes induced functional impairment and oxidative damage. Neurochem Res 38(10):2148–2159. PubMedPubMedCentralCrossRefGoogle Scholar
  39. 39.
    Marambio P, Toro B, Sanhueza C et al (2010) Glucose deprivation causes oxidative stress and stimulates aggresome formation and autophagy in cultured cardiac myocytes. Biochim Biophys Acta 1802(6):509–518. PubMedCrossRefGoogle Scholar
  40. 40.
    Matsuzawa A (2017) Thioredoxin and redox signaling: roles of the thioredoxin system in control of cell fate. Arch Biochem Biophys 617:101–105. PubMedCrossRefGoogle Scholar
  41. 41.
    Dunnill CJ, Ibraheem K, Mohamed A et al (2017) A redox state-dictated signalling pathway deciphers the malignant cell specificity of cd40-mediated apoptosis. Oncogene 36(18):2515–2528. PubMedCrossRefGoogle Scholar
  42. 42.
    Zafarullah M, Li WQ, Sylvester J et al (2003) Molecular mechanisms of n-acetylcysteine actions. Cell Mol Life Sci 60(1):6–20PubMedCrossRefGoogle Scholar
  43. 43.
    Liu RZ, Graham K, Glubrecht DD et al (2012) A fatty acid-binding protein 7/RXRbeta pathway enhances survival and proliferation in triple-negative breast cancer. J Pathol 228(3):310–321. PubMedCrossRefGoogle Scholar
  44. 44.
    Huo Y, Rangarajan P, Ling EA et al (2011) Dexamethasone inhibits the NOX-dependent ROS production via suppression of MKP-1-dependent MAPK pathways in activated microglia. BMC Neurosci 12:49. PubMedPubMedCentralCrossRefGoogle Scholar
  45. 45.
    Song HY, Ryu J, Ju SM et al (2007) Extracellular HIV-1 Tat enhances monocyte adhesion by up-regulation of ICAM-1 and VCAM-1 gene expression via ROS-dependent nf-kappab activation in astrocytes. Exp Mol Med 39(1):27–37. PubMedCrossRefGoogle Scholar
  46. 46.
    Lee JH, Kong J, Jang JY et al (2014) Lipid droplet protein lid-1 mediates atgl-1-dependent lipolysis during fasting in caenorhabditis elegans. Mol Cell Biol 34(22):4165–4176. PubMedPubMedCentralCrossRefGoogle Scholar
  47. 47.
    Granneman JG, Moore HP, Mottillo EP et al (2009) Functional interactions between Mldp (LSDP5) and Abhd5 in the control of intracellular lipid accumulation. J Biol Chem 284(5):3049–3057. PubMedPubMedCentralCrossRefGoogle Scholar
  48. 48.
    Gauthier MS, Miyoshi H, Souza SC et al (2008) Amp-activated protein kinase is activated as a consequence of lipolysis in the adipocyte: potential mechanism and physiological relevance. J Biol Chem 283(24):16514–16524. PubMedPubMedCentralCrossRefGoogle Scholar
  49. 49.
    Furukawa S, Fujita T, Shimabukuro M et al (2004) Increased oxidative stress in obesity and its impact on metabolic syndrome. J Clin Invest 114(12):1752–1761. PubMedPubMedCentralCrossRefGoogle Scholar
  50. 50.
    Murphy EJ, Rosenberger TA, Horrocks LA (1997) Effects of maturation on the phospholipid and phospholipid fatty acid compositions in primary rat cortical astrocyte cell cultures. Neurochem Res 22(10):1205–1213PubMedCrossRefGoogle Scholar
  51. 51.
    Zheng P, Xie Z, Yuan Y et al (2017) Plin5 alleviates myocardial ischaemia/reperfusion injury by reducing oxidative stress through inhibiting the lipolysis of lipid droplets. Sci Rep 7:42574. PubMedPubMedCentralCrossRefGoogle Scholar
  52. 52.
    Kuramoto K, Okamura T, Yamaguchi T et al (2012) Perilipin 5, a lipid droplet-binding protein, protects heart from oxidative burden by sequestering fatty acid from excessive oxidation. J Biol Chem 287(28):23852–23863. PubMedPubMedCentralCrossRefGoogle Scholar
  53. 53.
    Kalogeris T, Baines CP, Krenz M et al (2012) Cell biology of ischemia/reperfusion injury. Int Rev Cell Mol Biol 298:229–317. PubMedPubMedCentralCrossRefGoogle Scholar
  54. 54.
    Patten DA, Germain M, Kelly MA et al (2010) Reactive oxygen species: stuck in the middle of neurodegeneration. J Alzheimers Dis 20(Suppl 2):S357–S367. PubMedCrossRefGoogle Scholar
  55. 55.
    Blesa J, Trigo-Damas I, Quiroga-Varela A et al (2015) Oxidative stress and Parkinson’s disease. Front Neuroanat 9 (91).
  56. 56.
    Afanasiev SA, Egorova MV, Kondratyeva DS et al (2014) Comparative analysis of changes of myocardial angiogenesis and energy metabolism in postinfarction and diabetic damage of rat heart. J Diabetes Res 2014:827896. PubMedPubMedCentralCrossRefGoogle Scholar
  57. 57.
    Bailey AP, Koster G, Guillermier C et al (2015) Antioxidant role for lipid droplets in a stem cell niche of drosophila. Cell 163(2):340–353. PubMedPubMedCentralCrossRefGoogle Scholar
  58. 58.
    Welte MA (2015) Expanding roles for lipid droplets. Curr Biol 25(11):R470–R481. PubMedPubMedCentralCrossRefGoogle Scholar
  59. 59.
    Listenberger LL, Han X, Lewis SE et al (2003) Triglyceride accumulation protects against fatty acid-induced lipotoxicity. Proc Natl Acad Sci U S A 100(6):3077–3082. PubMedPubMedCentralCrossRefGoogle Scholar
  60. 60.
    Schaffer JE (2003) Lipotoxicity: when tissues overeat. Curr Opin Lipidol 14(3):281–287. PubMedCrossRefGoogle Scholar
  61. 61.
    Wilfling F, Wang H, Haas JT et al (2013) Triacylglycerol synthesis enzymes mediate lipid droplet growth by relocalizing from the ER to lipid droplets. Dev Cell 24(4):384–399. PubMedPubMedCentralCrossRefGoogle Scholar

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© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Organ AnatomyTohoku University Graduate School of MedicineSendaiJapan
  2. 2.Department of PharmacyUniversity of RajshahiRajshahiBangladesh
  3. 3.Department of AnatomyTohoku Medical and Pharmaceutical UniversitySendaiJapan

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