Isolation of Neuronal Synaptic Membranes by Sucrose Gradient Centrifugation

Hopiavuori, Blake R.; Masser, Dustin R.; Wilkerson, Joseph L.; Brush, Richard S.; Mandal, Nawajes A.; Anderson, Robert E.; Freeman, Willard M.

doi:10.1007/978-1-4939-6996-8_4

Cited by 4 publications

(2 citation statements)

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“…We identified two brain-derived VLC-SFA products of ELOVL4, 28:0 and 30:0 as components of sphingolipids. Furthermore, membrane fractionation and lipidomic analysis (Hopiavuori et al, 2017c) of freshly dissected baboon hippocampus revealed a dramatic enrichment of both 28:0 and 30:0 in synaptic vesicle membranes relative to the other membrane fractions analyzed (Hopiavuori et al, 2017b) (Fig. 9A–E).…”

Section: Understanding the Role Of Elovl4 In The Cns; A Shift To In Vmentioning

confidence: 94%

ELOVL4: Very long-chain fatty acids serve an eclectic role in mammalian health and function

Hopiavuori

Anderson

Agbaga

2019

Progress in Retinal and Eye Research

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ELO ngation of V ery L ong chain fatty acids- 4 (ELOVL4) is an elongase responsible for the biosynthesis of very long chain (VLC, ≥C28) saturated (VLC-SFA) and polyunsaturated (VLC-PUFA) fatty acids in brain, retina, skin, Meibomian glands, and testes. Fascinatingly, different mutations in this gene have been reported to cause vastly different phenotypes in humans. Heterozygous inheritance of seven different mutations in the coding sequence and 5’ untranslated region of ELOVL4 causes autosomal dominant Stargardt-like macular dystrophy (STGD3), while homozygous inheritance of three more mutant variants causes severe seizures with ichthyosis, hypertonia, and even death. Some recent studies have described heterozygous inheritance in yet another three mutant ELOVL4 variants, two that cause spinocerebellar ataxia-34 (SCA34) with erythrokeratodermia (EKV) and one that causes SCA34 without EKV. We identified the specific enzymatic reactions catalyzed by ELOVL4 and, using a variety of genetically engineered mouse models, have actively searched for the mechanisms by which ELOVL4 impacts neural function and health. In this review, we critically compare and contrast the various animal model and case studies involving ELOVL4 deficiency via either mutation or deletion, and the resulting consequences on neuronal health and function in both the retina and central nervous system.

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Section: Understanding the Role Of Elovl4 In The Cns; A Shift To In Vmentioning

confidence: 94%

ELOVL4: Very long-chain fatty acids serve an eclectic role in mammalian health and function

Hopiavuori

Anderson

Agbaga

2019

Progress in Retinal and Eye Research

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“…We used a modified version of the protocol described by VanGuilder et al [ 37 , 38 ]; see [ 39 ] for details. Briefly, five major membrane fractions were isolated along with a starting homogenate (H) from freshly dissected baboon hippocampus: P1 (nuclear), P2 (cytoskeletal), P3 (neurosynaptosomal), PSD (post-synaptic density), and SV (synaptic vesicle).…”

Section: Methodsmentioning

confidence: 99%

Homozygous Expression of Mutant ELOVL4 Leads to Seizures and Death in a Novel Animal Model of Very Long-Chain Fatty Acid Deficiency

et al. 2017

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Lipids are essential components of the nervous system. However, the functions of very long-chain fatty acids (VLC-FA; ≥ 28 carbons) in the brain are unknown. The enzyme ELOngation of Very Long-chain fatty acids-4 (ELOVL4) catalyzes the rate-limiting step in the biosynthesis of VLC-FA (Agbaga et al., Proc Natl Acad Sci USA 105(35): 12843–12848, 2008; Logan et al., J Lipid Res 55(4): 698–708, 2014), which we identified in the brain as saturated fatty acids (VLC-SFA). Homozygous mutations in ELOVL4 cause severe neuropathology in humans (Ozaki et al., JAMA Neurol 72(7): 797–805, 2015; Mir et al., BMC Med Genet 15: 25, 2014; Cadieux-Dion et al., JAMA Neurol 71(4): 470–475, 2014; Bourassa et al., JAMA Neurol 72(8): 942–943, 2015; Aldahmesh et al., Am J Hum Genet 89(6): 745–750, 2011) and are post-natal lethal in mice (Cameron et al., Int J Biol Sci 3(2): 111–119, 2007; Li et al., Int J Biol Sci 3(2): 120–128, 2007; McMahon et al., Molecular Vision 13: 258–272, 2007; Vasireddy et al., Hum Mol Genet 16(5): 471–482, 2007) from dehydration due to loss of VLC-SFA that comprise the skin permeability barrier. Double transgenic mice with homozygous knock-in of the Stargardt-like macular dystrophy (STDG3; 797-801_AACTT) mutation of Elovl4 with skin-specific rescue of wild-type Elovl4 expression (S + Elovl4 mut/mut mice) develop seizures by P19 and die by P21. Electrophysiological analyses of hippocampal slices showed aberrant epileptogenic activity in S + Elovl4 mut/mut mice. FM1-43 dye release studies showed that synapses made by cultured hippocampal neurons from S + Elovl4 mut/mut mice exhibited accelerated synaptic release kinetics. Supplementation of VLC-SFA to cultured hippocampal neurons from mutant mice rescued defective synaptic release to wild-type rates. Together, these studies establish a critical, novel role for ELOVL4 and its VLC-SFA products in regulating synaptic release kinetics and epileptogenesis. Future studies aimed at understanding the molecular mechanisms by which VLC-SFA regulate synaptic function may provide new targets for improved seizure therapies.Electronic supplementary materialThe online version of this article (10.1007/s12035-017-0824-8) contains supplementary material, which is available to authorized users.

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Plant‐Derived Vesicle‐Like Nanoparticles as Promising Biotherapeutic Tools: Present and Future

et al. 2023

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At present, it is generally acknowledged that EVs are secreted by almost all living cells including plant cells. [4] Compared with mammalian EVs, the research of plant EVs is still in its infancy. Increasing evidence has proved that plant cells are able to secret exosome-like vesicles or extracellular vesicles into apoplast space. [5] In the 1960s, using transmission electron microscopy (TEM), Halperin et al. for the first time observed and discovered multivesicular bodies (MVBs) fusing with the plasma membrane and releasing exosome-like vesicles into the cell wall area in carrot cell cultures. [6] Fifty years after this first discovery, Regenteet al. used a tissue-infiltration-centrifugation method and successfully separated exosome-like vesicles from apoplast washing fluids (AWF) of sunflower seeds. [5a] Following these discoveries, plant exosomelike vesicles or vesicle-like nanoparticles have been successfully isolated from many plant species, including ginseng, ginger, broccoli, bitter melon, oat, grape, grapefruit, lemon, blueberry, orange, sunflower seed, and Arabidopsis, etc. [5a,7] The efficient separation of PDVLNs from plant cells is still one of the challenges that need to be solved in the plant EV field. At present, two plant tissue pre-processing methods, namely tissue-disruption and tissue-infiltration centrifugation, have emerged as favorite methods used for vesicle separation from plant cells in the field. [5b,8] After tissue pre-treatment, most studies use ultracentrifugation or density gradient centrifugation for further PDVLN separation. [5a,9] In addition, novel separation methods are under development for PDVLNs, such as ultrafiltration, immunoaffinity capture, size-exclusive chromatography, etc. [5b,7j,10] However, it is still challenging to isolate specific PDVLN subtypes, due to the lack of generic or specific markers for PDVLNs and well-verified plant species antibodies. [4b,5b] The nomenclature of vesicles prepared by these methods is not standardized in existing references. Many terms were used, including "plant particles", "plant vesicles", etc. [7b,8b,10,11] To facilitate communication in the plant vesicle field, standardizing the nomenclatures is necessary. We thus propose to unify these nomenclatures into plant-derived vesicle-like nanoparticles (PDVLNs) in this review.PDVLNs share many similar physical characteristics to those of human-derived EVs, including features such as morphology, particle size, concentration, Zeta potential, etc. [2a,7b,e,11] To further elucidate the specific molecular mechanism of PDVLNs on Extracellular vesicles (EVs) are heterogeneous, phospholipid bilayer-enclosed biological particles that regulate cell communication by molecular cargo delivery and surface signaling. EVs are secreted by almost all living cells, including plant cells. Plant-derived vesicle-like nanoparticles (PDVLNs) is a generic term referring to vesicle-like nanostructure particles isolated from plants. Their low immunogenicity and wide availability make PDVLNs safer and mor...

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Isolation of Neuronal Synaptic Membranes by Sucrose Gradient Centrifugation

Cited by 4 publications

References 11 publications

ELOVL4: Very long-chain fatty acids serve an eclectic role in mammalian health and function

ELOVL4: Very long-chain fatty acids serve an eclectic role in mammalian health and function

Homozygous Expression of Mutant ELOVL4 Leads to Seizures and Death in a Novel Animal Model of Very Long-Chain Fatty Acid Deficiency

Plant‐Derived Vesicle‐Like Nanoparticles as Promising Biotherapeutic Tools: Present and Future

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