51
|
Dossey AT. Insects and their chemical weaponry: New potential for drug discovery. Nat Prod Rep 2010; 27:1737-57. [DOI: 10.1039/c005319h] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
52
|
Alves BN, Marshall K, Tamang DL, Leong J, Redelman D, Elliott V, Lowe ME, Hudig D. Lipid-dependent cytotoxicity by the lipase PLRP2 and by PLRP2-positive cytotoxic T lymphocytes (CTLs). Cell Biochem Funct 2009; 27:296-308. [PMID: 19548271 DOI: 10.1002/cbf.1573] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IL-4 induces a lipase, pancreatic lipase related protein 2 (PLRP2), in cytotoxic T lymphocytes (CTLs). Because PLRP2 in semen can mediate lipid-dependent toxicity to sperm, we questioned whether CTL-derived PLRP2 could support similar cytotoxicity toward tumor cells. Recombinant PLRP2 was toxic to P815 tumor cells in 48 h when lipid and another protein, colipase, were present. However, PLRP2-positive CTLs (induced with many lots of IL-4) were unable to mediate lipid-dependent cytotoxicity. Notably, CTLs induced with only one lot of IL-4 had lipid-dependent cytotoxicity. The exceptional lot of IL-4 was effective in multiple experiments at inducing lipid-dependent cytotoxicity. The lipid-dependent cytotoxicity it induced was determined to be perforin-independent. CTLs induced with IL-4 that was unable to induce lipid-dependent cytotoxicity had mRNA for PLRP2 but not mRNA for colipase. Therefore, we added exogenous colipase to the CTL assays but still cytotoxicity was unchanged. We conclude (1) that lipid-dependent cytotoxicity, promoted by the lipase PLRP2 and colipase, will kill tumor cells and (2) that more than PLRP2 alone is required for lipid-dependent cytotoxicity mediated by CTLs.
Collapse
Affiliation(s)
- Bryce N Alves
- Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, NV 89557, USA.
| | | | | | | | | | | | | | | |
Collapse
|
53
|
Leekumjorn S, Cho HJ, Wu Y, Wright NT, Sum AK, Chan C. The role of fatty acid unsaturation in minimizing biophysical changes on the structure and local effects of bilayer membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:1508-16. [PMID: 19371719 DOI: 10.1016/j.bbamem.2009.04.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 02/15/2009] [Revised: 04/06/2009] [Accepted: 04/06/2009] [Indexed: 11/18/2022]
Abstract
Studying the effects of saturated and unsaturated fatty acids on biological and model (liposomes) membranes could provide insight into the contribution of biophysical effects on the cytotoxicity observed with saturated fatty acids. In vitro experiments suggest that unsaturated fatty acids, such as oleate and linoleate, are less toxic, and have less impact on the membrane fluidity. To understand and assess the biophysical changes in the presence of the different fatty acids, we performed computational analyses of model liposomes with palmitate, oleate, and linoleate. The computational results indicate that the unsaturated fatty acid chain serves as a membrane stabilizer by preventing changes to the membrane fluidity. Based on a Voronoi tessellation analysis, unsaturated fatty acids have structural properties that can reduce the lipid ordering within the model membranes. In addition, hydrogen bond analysis indicates a more uniform level of membrane hydration in the presence of oleate and linoleate as compared to palmitate. Altogether, these observations from the computational studies provide a possible mechanism by which unsaturated fatty acids minimize biophysical changes and protect the cellular membrane and structure. To corroborate our findings, we also performed a liposomal leakage study to assess how the different fatty acids alter the membrane integrity of liposomes. This showed that palmitate, a saturated fatty acid, caused greater destabilization of liposomes (more "leaky") than oleate, an unsaturated fatty acid.
Collapse
Affiliation(s)
- Sukit Leekumjorn
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | | | | | | | | | | |
Collapse
|
54
|
Alves B, Leong J, Tamang DL, Elliott V, Lowe M, Hudig D. Hydrolysis of tumor cell lipids after CTL-mediated death. Int Immunol 2009; 21:543-53. [PMID: 19325035 DOI: 10.1093/intimm/dxp026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Contributions of lipases to CTL function have been debated, including if T cell lipases damage target cells. Expression of the lipase pancreatic lipase-related protein 2 (PLRP2) was previously found in IL-4 cultured lymphocyte cell lines but absent from IL-2 cultured lymphocytes. Here, we evaluated IL-2 and IL-4 induced CTLs for hydrolysis of target cell lipids and killing. Using anti-CD3 redirected lysis of [(3)H]-oleic acid-labeled P815 tumor cells, we detected the release of the radioactive fatty acid (FA). When PLRP2(+/+) and PLRP2(-/-) CTLs were compared, there was more killing by the PLRP2(+/+) CTLs. However, [(3)H]-oleic acid release was similar per dead P815, suggesting that lipid hydrolysis was produced by the dead P815s rather than by PLRP2. The FA release and death were completely dependent on perforin and also occurred when P815s were killed by perforin-containing T cell granule extracts that lacked lipase activity. Death by the cytotoxic granules extracts was unaffected by the addition of lipases. A lipase inhibitor, tetrahydrolipstatin, blocked FA release without affecting CTL-mediated cytotoxicity. Also, CTL-mediated death caused as much FA release as death by disruption of cells by freeze-thawing. The released oleic acid may be sufficient to promote secondary apoptotic responses after CTL-induced trauma.
Collapse
Affiliation(s)
- Bryce Alves
- Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, NV 89557, USA.
| | | | | | | | | | | |
Collapse
|
55
|
Kwon JI, Kim GY, Park KY, Ryu CH, Choi YH. Induction of apoptosis by linoleic acid is associated with the modulation of Bcl-2 family and Fas/FasL system and activation of caspases in AGS human gastric adenocarcinoma cells. J Med Food 2008; 11:1-8. [PMID: 18361731 DOI: 10.1089/jmf.2007.073] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In this study, we investigated the effects of linoleic acid (LA), a polyunsaturated fatty acid found in most vegetable oils and certain food products, on the growth of AGS human gastric adenocarcinoma cells. LA treatment resulted in a concentration-dependent growth inhibition of AGS cells by inducing apoptosis, as evidenced by the formation of apoptotic bodies, chromatin condensation, and the accumulation cells in the sub-G1 phase. LA treatment induced cyclin-dependent kinase inhibitor p21 in a p53-independent manner; however, this compound did not affect the cell cycle distribution. Reverse transcription-polymerase chain reaction and western blot analyses showed that treating the cells with LA caused the up-regulation of pro-apoptotic Bax expression and the down-regulation of anti-apoptotic Bcl-2 expression. The apoptosis of AGS cells by LA was found to be associated with an elevated Fas and Fas ligand expression in a concentration-dependent manner. Furthermore, a proteolytic activation of caspases (3, 8, and 9), and degradation/cleavage of poly(ADP-ribose) polymerase and phospholipase C-gamma 1 protein were noted in LA-treated AGS cells. The present results indicate that the Fas/Fas ligand pathway might be involved in LA-induced apoptosis of AGS cells.
Collapse
Affiliation(s)
- Jae Im Kwon
- Department of Biochemistry, Dongeui University College of Oriental Medicine, Busan, Republic of Korea
| | | | | | | | | |
Collapse
|
56
|
Experimental and computational studies investigating trehalose protection of HepG2 cells from palmitate-induced toxicity. Biophys J 2007; 94:2869-83. [PMID: 18096630 DOI: 10.1529/biophysj.107.120717] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Understanding the mechanism of saturated fatty acid-induced hepatocyte toxicity may provide insight into cures for diseases such as obesity-associated cirrhosis. Trehalose, a nonreducing disaccharide shown to protect proteins and cellular membranes from inactivation or denaturation caused by different stress conditions, also protects hepatocytes from palmitate-induced toxicity. Our results suggest that trehalose serves as a free radical scavenger and alleviates damage from hydrogen peroxide secreted by the compromised cells. We also observe that trehalose protects HepG2 cells by interacting with the plasma membrane to counteract the changes in membrane fluidity induced by palmitate. The experimental results are supported by molecular dynamics simulations of model cell membranes that closely reflect the experimental conditions. Simulations were performed to understand the specific interactions between lipid bilayers, palmitate, and trehalose. The simulations results reveal the early stages of how palmitate induces biophysical changes to the cellular membrane and the role of trehalose in protecting the membrane structure.
Collapse
|
57
|
Yoo YC, Shin BH, Hong JH, Lee J, Chee HY, Song KS, Lee KB. Isolation of fatty acids with anticancer activity from Protaetia brevitarsis larva. Arch Pharm Res 2007; 30:361-5. [PMID: 17424944 DOI: 10.1007/bf02977619] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this study, biologically active compounds were isolated from Protaetia brevitarsis larva (PBL) by dichloromethane extraction. The dichloromethane extract from PBL was highly cytotoxic to various cancer cells. From a silica gel column chromatograpy of this extract, we obtained four fractions (F-2, F-4, F-5 and F-7) having apoptosis-inducing activity. These fractions induced DNA ladder and caspase-3 activation during apoptosis in colon 26 tumor cells. In 1H and 13C NMR and mass spectral analysis of the fraction F-2 showing the highest apoptosis-inducing activity, we found that the fraction was composed of three free fatty acids such as palmitic acid, (Z)-9-octadecenoic acid and octadecenoic acid. These results indicate that the dichloromethane extract of PBL includes anticancer components composed of at least three fatty acids, and apoptosis-inducing activity of the extract was mediated by caspase-3 activation in tumor cells.
Collapse
Affiliation(s)
- Yung-Choon Yoo
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 302-801, Korea
| | | | | | | | | | | | | |
Collapse
|
58
|
Lucci CM, Schreier LL, Machado GM, Amorim CA, Báo SN, Dobrinsky JR. Effects of storing pig ovaries at 4 or 20 degrees C for different periods of time on the morphology and viability of pre-antral follicles. Reprod Domest Anim 2007; 42:76-82. [PMID: 17214778 DOI: 10.1111/j.1439-0531.2006.00734.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The purpose of this study was to evaluate the effect of cooling ovarian tissue on pig pre-antral follicles. Ovaries were maintained in saline solution (0.9%) at 4 or 20 degrees C for 6, 12 or 18 h. After storage, pre-antral follicles were morphologically evaluated. While primordial follicles were not affected by the storage, the percentage of morphologically normal growing follicles was significantly reduced in ovarian tissue stored at 20 degrees C for 12 or 18 h. To test the viability of stored follicles, growing follicles isolated from ovaries stored at 4 degrees C for 18 h and at 20 degrees C for 6 h were cultured for 3 days. Follicles stored in either condition presented the same growth pattern in vitro as fresh follicles. We conclude that storage of pig ovaries at 4 degrees C for up to 18 h or at 20 degrees C for up to 6 h does not affect the morphology of growing follicles or their ability to grow in vitro.
Collapse
Affiliation(s)
- C M Lucci
- Germplasm and Gamete Physiology Laboratory, Agricultural Research Service, US Department of Agriculture, Beltsville, MD, USA.
| | | | | | | | | | | |
Collapse
|
59
|
Martins de Lima T, Cury-Boaventura MF, Giannocco G, Nunes MT, Curi R. Comparative toxicity of fatty acids on a macrophage cell line (J774). Clin Sci (Lond) 2006; 111:307-17. [PMID: 16737441 DOI: 10.1042/cs20060064] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the present study, the cytotoxicity of palmitic, stearic, oleic, linoleic, arachidonic, docosahexaenoic and eicosapentaenoic acids on a macrophage cell line (J774) was investigated. The induction of toxicity was investigated by changes in cell size, granularity, membrane integrity, DNA fragmentation and phosphatidylserine externalization by using flow cytometry. Fluorescence microscopy was used to determine the type of cell death (Acridine Orange/ethidium bromide assay). The possible mechanisms involved were examined by measuring mitochondrial depolarization, lipid accumulation and PPARgamma (peroxisome-proliferator-activated receptor gamma) activation. The results demonstrate that fatty acids induce apoptosis and necrosis of J774 cells. At high concentrations, fatty acids cause macrophage death mainly by necrosis. The cytotoxicity of the fatty acids was not strictly related to the number of double bonds in the molecules: palmitic acid>docosahexaenoic acid>stearic acid=eicosapentaenoic acid=arachidonic acid>oleic acid>linoleic acid. The induction of cell death did not involve PPARgamma activation. The mechanisms of fatty acids to induce cell death involved changes in mitochondrial transmembrane potential and intracellular neutral lipid accumulation. Fatty acids poorly incorporated into triacylglycerol had the highest toxicity.
Collapse
Affiliation(s)
- Thais Martins de Lima
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, CEP 05508-900, São Paulo, Brazil.
| | | | | | | | | |
Collapse
|
60
|
Sommers CH. Induction of Micronuclei in Human TK6 Lymphoblasts by 2-Dodecylcyclobutanone, a Unique Radiolytic Product of Palmitic Acid. J Food Sci 2006. [DOI: 10.1111/j.1750-3841.2006.00032.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
61
|
Carballeira NM, Miranda C, Orellano EA, González FA. Synthesis of a novel series of 2-methylsulfanyl fatty acids and their toxicity on the human K-562 and U-937 leukemia cell lines. Lipids 2006; 40:1063-8. [PMID: 16382579 PMCID: PMC1618881 DOI: 10.1007/s11745-005-1470-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hitherto unknown 2-methylsulfanyldecanoic acid and 2-methylsulfanyldodecanoic acid were synthesized from methyl decanoate and methyl dodecanoate, respectively, through the reaction of lithium diisopropylamide and dimethyldisulfide in THF followed by saponification with potassium hydroxide in ethanol. Both alpha-methylsulfanylated FA were cytotoxic to the human chronic myelogenous leukemia K-562 and the human histiocytic lymphoma U-937 cell lines with EC50 values in the 200-300 microM range, which makes them more cytotoxic to these cell lines than decanoic and/or dodecanoic acid. The cytotoxicity of the studied FA toward K-562 followed the order 2-SCH3-12:0 > 2-SCH3-10:0 > 10:0 > 12:0 > 2-OCH3-12:0, whereas toward U-937 the cytotoxicity was 2-SCH3-10:0 > 2-SCH3-12:0 > 12:0 > 10:0 > 2-OCH3-12:0. These results indicate that the alpha-methylsulfanyl substitution increases the cytotoxicity of the C10 and C12 FA toward the studied leukemia cell lines.
Collapse
|