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Woods-Burnham L, Stiel L, Martinez SR, Sanchez-Hernandez ES, Ruckle HC, Almaguel FG, Stern MC, Roberts LR, Williams DR, Montgomery S, Casiano CA. Psychosocial Stress, Glucocorticoid Signaling, and Prostate Cancer Health Disparities in African American Men. Cancer Health Disparities 2020; 4:https://companyofscientists.com/index.php/chd/article/view/169/188. [PMID: 35252767 PMCID: PMC8896511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Recent advances in our understanding of racial disparities in prostate cancer (PCa) incidence and mortality that disproportionately affect African American (AA) men have provided important insights into the psychosocial, socioeconomic, environmental, and molecular contributors. There is, however, limited mechanistic knowledge of how the interplay between these determinants influences prostate tumor aggressiveness in AA men and other men of African ancestry. Growing evidence indicates that chronic psychosocial stress in AA populations leads to sustained glucocorticoid signaling through the glucocorticoid receptor (GR), with negative physiological and pathological consequences. Compelling evidence indicates that treatment of castration-resistant prostate cancer (CRPC) with anti-androgen therapy activates GR signaling. This enhanced GR signaling bypasses androgen receptor (AR) signaling and transcriptionally activates both AR-target genes and GR-target genes, resulting in increased prostate tumor resistance to anti-androgen therapy, chemotherapy, and radiotherapy. Given its enhanced signaling in AA men, GR-together with specific genetic drivers-may promote CRPC progression and exacerbate tumor aggressiveness in this population, potentially contributing to PCa mortality disparities. Ongoing and future CRPC clinical trials that combine standard of care therapies with GR modulators should assess racial differences in therapy response and clinical outcomes in order to improve PCa health disparities that continue to exist for AA men.
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Affiliation(s)
- Leanne Woods-Burnham
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Laura Stiel
- Loma Linda University School of Behavioral Health, Loma Linda, CA, USA
| | - Shannalee R. Martinez
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Evelyn S. Sanchez-Hernandez
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Herbert C. Ruckle
- Department of Surgical Urology, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Frankis G. Almaguel
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA
- Loma Linda University Cancer Center, Loma Linda, CA, USA
| | - Mariana C. Stern
- Departments of Preventive Medicine and Urology, University of Southern California Keck School of Medicine, Los Angeles, CA
| | - Lisa R. Roberts
- Loma Linda University School of Nursing, Loma Linda, CA, USA
| | - David R. Williams
- Department of Social and Behavioral Sciences, Harvard University School of Public Health
| | - Susanne Montgomery
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA
- Loma Linda University School of Behavioral Health, Loma Linda, CA, USA
| | - Carlos A. Casiano
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, USA
- Department of Medicine, Loma Linda University School of Medicine, Loma Linda, CA, USA
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Sattiraju A, Solingapuram Sai KK, Xuan A, Pandya DN, Almaguel FG, Wadas TJ, Herpai DM, Debinski W, Mintz A. IL13RA2 targeted alpha particle therapy against glioblastomas. Oncotarget 2018; 8:42997-43007. [PMID: 28562337 PMCID: PMC5522122 DOI: 10.18632/oncotarget.17792] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/15/2017] [Indexed: 12/22/2022] Open
Abstract
Glioblastoma (GBM) is the most aggressive primary malignant brain cancer that invariably results in a dismal prognosis. Chemotherapy and radiotherapy have not been completely effective as standard treatment options for patients due to recurrent disease. We and others have therefore developed molecular strategies to specifically target interleukin 13 receptor alpha 2 (IL13RA2), a GBM restricted receptor expressed abundantly on over 75% of GBM patients. In this work, we evaluated the potential of Pep-1L, a novel IL13RA2 targeted peptide, as a platform to deliver targeted lethal therapies to GBM. To demonstrate GBM-specificity, we radiolabeled Pep-1L with Copper-64 and performed in vitro cell binding studies, which demonstrated specific binding that was blocked by unlabeled Pep-1L. Furthermore, we demonstrated real-time GBM localization of [64Cu]Pep-1L to orthotopic GBMs using small animal PET imaging. Based on these targeting data, we performed an initial in vivo safety and therapeutic study using Pep-1L conjugated to Actinium-225, an alpha particle emitter that has been shown to potently and irreversibly kill targeted cells. We infused [225Ac]Pep-1L into orthotopic GBMs using convection-enhanced delivery and found no significant adverse events at injected doses. Furthermore, our initial data also demonstrated significantly greater overall, median and mean survival in treated mice when compared to those in control groups (p < 0.05). GBM tissue extracted from mice treated with [225Ac]Pep-1L showed double stranded DNA breaks, lower Ki67 expression and greater propidium iodide internalization, indicating anti-GBM therapeutic effects of [225Ac]Pep-1L. Based on our results, Pep-1L warrants further investigation as a potential targeted platform to deliver anti-cancer agents.
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Affiliation(s)
- Anirudh Sattiraju
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.,Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Winston-Salem, NC 27157, USA
| | - Kiran Kumar Solingapuram Sai
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.,Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Winston-Salem, NC 27157, USA
| | - Ang Xuan
- Department of Nuclear Medicine and Radiology, The People's Hospital of Zhengzhou University, Zhengzhou, Henan 450003, China
| | - Darpan N Pandya
- Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Winston-Salem, NC 27157, USA
| | - Frankis G Almaguel
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Thaddeus J Wadas
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.,Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Denise M Herpai
- Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Winston-Salem, NC 27157, USA.,Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Waldemar Debinski
- Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Winston-Salem, NC 27157, USA.,Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Akiva Mintz
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.,Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Winston-Salem, NC 27157, USA
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Sai KKS, Sattiraju A, Almaguel FG, Xuan A, Rideout S, Krishnaswamy RS, Zhang J, Herpai DM, Debinski W, Mintz A. Peptide-based PET imaging of the tumor restricted IL13RA2 biomarker. Oncotarget 2017; 8:50997-51007. [PMID: 28881623 PMCID: PMC5584224 DOI: 10.18632/oncotarget.16549] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/27/2017] [Indexed: 11/25/2022] Open
Abstract
Peptides that target cancer cell surface receptors are promising platforms to deliver diagnostic and therapeutic payloads specifically to cancer but not normal tissue. IL13RA2 is a tumor-restricted receptor found to be present in several aggressive malignancies, including in the vast majority of high-grade gliomas and malignant melanoma. This receptor has been successfully targeted for diagnostic and therapeutic purposes using modified IL-13 ligand and more recently using a specific peptide, Pep-1L. In the current work, we establish the in vitro and in vivo tumor binding properties of radiolabeled Pep-1L, designed for tumor imaging. We radiolabeled Pep-1L with Copper-64 and demonstrated specific cell uptake in the IL13RA2-over expressing G48 glioblastoma cell line having abundant IL13RA2 expression. [64Cu]Pep-1L binding was blocked by unlabeled ligand, demonstrating specificity. To demonstrate in vivo tumor uptake, we intravenously injected into tumor-bearing mice and demonstrated that [64Cu]Pep-1L specifically bound tumors at 24 hours, which was significantly blocked (3-fold) by pre-injecting unlabeled peptide. To further demonstrate specificity of Pep-1L towards IL13RA2 in vivo, we exploited an IL13RA2-inducible melanoma tumor model that does not express receptor at baseline but expresses abundant receptor after treatment with doxycycline. We injected [64Cu]Pep-1L into mice bearing IL13RA2-inducible melanoma tumors and performed in vivo PET/CT and post-necropsy biodistribution studies and found that tumors that were induced to express IL13RA2 receptor by doxycycline pretreatment bound radiolabeled Pep-1L 3-4 fold greater than uninduced tumors, demonstrating receptor specificity. This work demonstrates that [64Cu]Pep-1L selectively binds hIL13RA2-expressing tumors and validates Pep-1L as an effective platform to deliver diagnostics and therapeutics to IL13RA2-expressing cancers.
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Affiliation(s)
| | - Anirudh Sattiraju
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Frankis G Almaguel
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Ang Xuan
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Stephanie Rideout
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | | | - JoAnn Zhang
- MicroPET/CT Imaging Section, TriFoil Imaging, Chatsworth, CA, USA
| | - Denise M Herpai
- Department of Cancer Biology, Brain Tumor Center of Excellence, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Waldemar Debinski
- Department of Cancer Biology, Brain Tumor Center of Excellence, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Akiva Mintz
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
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Pacheco FJ, Almaguel FG, Evans W, Rios-Colon L, Filippov V, Leoh LS, Rook-Arena E, Mediavilla-Varela M, De Leon M, Casiano CA. Docosahexanoic acid antagonizes TNF-α-induced necroptosis by attenuating oxidative stress, ceramide production, lysosomal dysfunction, and autophagic features. Inflamm Res 2014; 63:859-71. [PMID: 25095742 DOI: 10.1007/s00011-014-0760-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 06/02/2014] [Accepted: 07/23/2014] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE It was previously reported that docosahexanoic acid (DHA) reduces TNF-α-induced necrosis in L929 cells. However, the mechanisms underlying this reduction have not been investigated. The present study was designed to investigate cellular and biochemical mechanisms underlying the attenuation of TNF-α-induced necroptosis by DHA in L929 cells. METHODS L929 cells were pre-treated with DHA prior to exposure to TNF-α, zVAD, or Necrostatin-1 (Nec-1). Cell death and survival were assessed by MTT and caspase activity assays, and microscopic visualization. Reactive oxygen species (ROS) were measured by flow cytometry. C16- and C18-ceramides were measured by mass spectrometry. Lysosomal membrane permeabilization (LMP) was evaluated by fluorescence microscopy and flow cytometry using Acridine Orange. Cathepsin L activation was evaluated by immunoblotting and fluorescence microscopy. Autophagy was assessed by immunoblotting of LC3-II and Beclin. RESULTS Exposure of L929 cells to TNF-α alone for 24 h induced necroptosis, as evidenced by the inhibition of cell death by Nec-1, absence of caspase-3 activity and Lamin B cleavage, and morphological analysis. DHA attenuated multiple biochemical events associated with TNF-α-induced necroptosis, including ROS generation, ceramide production, lysosomal dysfunction, cathepsin L activation, and autophagic features. DHA also attenuated zVAD-induced necroptosis but did not attenuate the enhanced apoptosis and necrosis induced by the combination of TNF-α with Actinomycin D or zVAD, respectively, suggesting that its protective effects might be limited by the strength of the cell death insult induced by TNF-α. CONCLUSIONS DHA effectively attenuates TNF-α-induced necroptosis and autophagy, most likely via its ability to inhibit TNF-α-induced sphingolipid metabolism and oxidative stress. These results highlight the role of this Omega-3 fatty acid in antagonizing inflammatory cell death.
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Affiliation(s)
- Fabio J Pacheco
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
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Figueroa JD, Cordero K, Serrano-Illan M, Almeyda A, Baldeosingh K, Almaguel FG, De Leon M. Metabolomics uncovers dietary omega-3 fatty acid-derived metabolites implicated in anti-nociceptive responses after experimental spinal cord injury. Neuroscience 2013; 255:1-18. [PMID: 24042033 DOI: 10.1016/j.neuroscience.2013.09.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 01/23/2023]
Abstract
Chronic neuropathic pain is a frequent comorbidity following spinal cord injury (SCI) and often fails to respond to conventional pain management strategies. Preventive administration of docosahexaenoic acid (DHA) or the consumption of a diet rich in omega-3 polyunsaturated fatty acids (O3PUFAs) confers potent prophylaxis against SCI and improves functional recovery. The present study examines whether this novel dietary strategy provides significant antinociceptive benefits in rats experiencing SCI-induced pain. Rats were fed control chow or chow enriched with O3PUFAs for 8weeks before being subjected to sham or cord contusion surgeries, continuing the same diets after surgery for another 8 more weeks. The paw sensitivity to noxious heat was quantified for at least 8weeks post-SCI using the Hargreaves test. We found that SCI rats consuming the preventive O3PUFA-enriched diet exhibited a significant reduction in thermal hyperalgesia compared to those consuming the normal diet. Functional neurometabolomic profiling revealed a distinctive deregulation in the metabolism of endocannabinoids (eCB) and related N-acyl ethanolamines (NAEs) at 8weeks post-SCI. We found that O3PUFAs consumption led to a robust accumulation of novel NAE precursors, including the glycerophospho-containing docosahexaenoyl ethanolamine (DHEA), docosapentaenoyl ethanolamine (DPEA), and eicosapentaenoyl ethanolamine (EPEA). The tissue levels of these metabolites were significantly correlated with the antihyperalgesic phenotype. In addition, rats consuming the O3PUFA-rich diet showed reduced sprouting of nociceptive fibers containing CGRP and dorsal horn neuron p38 mitogen-activated protein kinase (MAPK) expression, well-established biomarkers of pain. The spinal cord levels of inositols were positively correlated with thermal hyperalgesia, supporting their role as biomarkers of chronic neuropathic pain. Notably, the O3PUFA-rich dietary intervention reduced the levels of these metabolites. Collectively, these results demonstrate the prophylactic value of dietary O3PUFA against SCI-mediated chronic pain.
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Affiliation(s)
- J D Figueroa
- Center for Health Disparities and Molecular Medicine, Loma Linda University, Loma Linda, CA, United States; Department of Basic Sciences, Loma Linda University, Loma Linda, CA, United States; Department of Pathology and Human Anatomy, Loma Linda University, Loma Linda, CA, United States
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Almaguel FG, Liu JW, Pacheco FJ, De Leon D, Casiano CA, De Leon M. Lipotoxicity-mediated cell dysfunction and death involve lysosomal membrane permeabilization and cathepsin L activity. Brain Res 2010; 1318:133-43. [PMID: 20043885 DOI: 10.1016/j.brainres.2009.12.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 12/10/2009] [Accepted: 12/12/2009] [Indexed: 01/03/2023]
Abstract
Lipotoxicity, which is triggered when cells are exposed to elevated levels of free fatty acids, involves cell dysfunction and apoptosis and is emerging as an underlying factor contributing to various pathological conditions including disorders of the central nervous system and diabetes. We have shown that palmitic acid (PA)-induced lipotoxicity (PA-LTx) in nerve growth factor-differentiated PC12 (NGFDPC12) cells is linked to an augmented state of cellular oxidative stress (ASCOS) and apoptosis and that these events are inhibited by docosahexanoic acid (DHA). The mechanisms of PA-LTx in nerve cells are not well understood, but our previous findings indicate that it involves ROS generation, mitochondrial membrane permeabilization (MMP), and caspase activation. The present study used nerve growth factor differentiated PC12 cells (NGFDPC12 cells) and found that lysosomal membrane permeabilization (LMP) is an early event during PA-induced lipotoxicity that precedes MMP and apoptosis. Cathepsin L, but not cathepsin B, is an important contributor in this process since its pharmacological inhibition significantly attenuated LMP, MMP, and apoptosis. In addition, co-treatment of NGFDPC12 cells undergoing lipotoxicity with DHA significantly reduced LMP, suggesting that DHA acts by antagonizing upstream signals leading to lysosomal dysfunction. These results suggest that LMP is a key early mediator of lipotoxicity and underscore the value of interventions targeting upstream signals leading to LMP for the treatment of pathological conditions associated with lipotoxicity.
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Affiliation(s)
- Frankis G Almaguel
- Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Mortensen Hall 142, 11085 Campus St., Loma Linda, CA 92350, USA
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Almaguel FG, Liu JW, Pacheco FJ, Casiano CA, De Leon M. Activation and reversal of lipotoxicity in PC12 and rat cortical cells following exposure to palmitic acid. J Neurosci Res 2009; 87:1207-18. [PMID: 18951473 DOI: 10.1002/jnr.21918] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Lipotoxicity involves a series of pathological cellular responses after exposure to elevated levels of fatty acids. This process may be detrimental to normal cellular homeostasis and cell viability. The present study shows that nerve growth factor-differentiated PC12 cells (NGFDPC12) and rat cortical cells (RCC) exposed to high levels of palmitic acid (PA) exhibit significant lipotoxicity and death linked to an "augmented state of cellular oxidative stress" (ASCOS). The ASCOS response includes generation of reactive oxygen species (ROS), alterations in the mitochondrial transmembrane potential, and increase in the mRNA levels of key cell death/survival regulatory genes. The observed cell death was apoptotic based on nuclear morphology, caspase-3 activation, and cleavage of lamin B and PARP. Quantitative real-time PCR measurements showed that cells undergoing lipotoxicity exhibited an increase in the expression of the mRNAs encoding the cell death-associated proteins BNIP3 and FAS receptor. Cotreatment of NGFDPC12 and RCC cells undergoing lipotoxicity with docosahexaenoic acid (DHA) and bovine serum albumin (BSA) significantly reduced cell death within the first 2 hr following the initial exposure to PA. The data suggest that lipotoxicity in NGFDPC12 and cortical neurons triggers a strong cell death apoptotic response. Results with NGFDPC12 cells suggest a linkage between induction of ASCOS and the apoptotic process and exhibit a temporal window that is sensitive to DHA and BSA interventions.
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Affiliation(s)
- Frankis G Almaguel
- Center for Health Disparities and Molecular Medicine and Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, California 92350, USA
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Liu JW, Almaguel FG, Bu L, De Leon DD, De Leon M. Expression of E-FABP in PC12 cells increases neurite extension during differentiation: involvement of n-3 and n-6 fatty acids. J Neurochem 2008; 106:2015-29. [PMID: 18513372 DOI: 10.1111/j.1471-4159.2008.05507.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Epidermal fatty acid-binding protein (E-FABP), a member of the family of FABPs, exhibits a robust expression in neurons during axonal growth in development and in nerve regeneration following nerve injury. This study examines the impact of E-FABP expression in normal neurite extension in differentiating pheochromocytoma cell (PC12) cultures supplemented with selected long chain free fatty acids (LCFFA). We found that E-FABP binds to a broad range of saturated and unsaturated LCFFAs, including those with potential interest for neuronal differentiation and axonal growth such as C22:6n-3 docosahexaenoic acid (DHA), C20:5n-3 eicosapentaenoic acid (EPA), and C20:4n-6 arachidonic acid (ARA). PC12 cells exposed to nerve growth factor (NGFDPC12) exhibit high E-FABP expression that is blocked by mitogen-activated protein kinase kinase (MEK) inhibitor U0126. Nerve growth factor-differentiated pheochromocytoma cells (NGFDPC12) antisense clones (NGFDPC12-AS) which exhibit low E-FABP expression have fewer/shorter neurites than cells transfected with vector only or NGFDPC12 sense cells (NGFDPC12-S). Replenishing NGFDPC12-AS cells with biotinylated recombinant E-FABP (biotin-E-FABP) protein restores normal neurite outgrowth. Cellular localization of biotin-E-FABP in NGFDPC12 was detected mostly in the cytoplasm and in the nuclear region. Treatment of NGFDPC12 with DHA, EPA, or ARA further enhances neurite length but it does not trigger further induction of TrkA or MEK phosphorylation or E-FABP mRNA observed in differentiating PC12 cells without LCFFA supplementation. Significantly, DHA and EPA neurite stimulating effects are higher in NGFDPC12-S than in NGFDPC12-AS cells. These findings are consistent with the scenario that neurite extension of differentiating PC12 cells, including further stimulation by DHA and EPA, requires sufficient cellular levels of E-FABP.
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Affiliation(s)
- Jo-Wen Liu
- Center for Health Disparities and Molecular Medicine, Department of Basic Science, Loma Linda University, California 92350, USA
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Ulloth JE, Almaguel FG, Padilla A, Bu L, Liu JW, De Leon M. Characterization of methyl-beta-cyclodextrin toxicity in NGF-differentiated PC12 cell death. Neurotoxicology 2007; 28:613-21. [PMID: 17292476 PMCID: PMC1994916 DOI: 10.1016/j.neuro.2007.01.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 12/21/2006] [Accepted: 01/04/2007] [Indexed: 12/17/2022]
Abstract
Cyclodextrins (CDs) are used to deliver hydrophobic molecules in aqueous environments. Methyl-beta-cyclodextrin (MbetaCD), a member of this family of molecules, has been proposed to be a good carrier to deliver fatty acids to cells in culture. This report focuses on studying the in vitro effects of MbetaCD on nerve growth factor-differentiated PC12 (NGFDPC12) cells, a tissue culture model to study neuronal survival and differentiation. The main findings are: (1) NGFDPC12 cells have normal viability when exposed to 0.12% MbetaCD but showed a significant loss in cell viability at higher concentrations; (2) NGFDPC12 cells exposed to 0.25% MbetaCD exhibit nuclear condensation, blebbing and apoptotic bodies, and whole cell lysates exhibited an increase in caspase-3-like activity and high levels of Bax and Bcl-X(L) protein expression compared to control. Cultures treated with 0.25% MbetaCD also showed cleavage of normal 21-kDa Bax protein into a 18-kDa fragment. (3) Experiments using 0.12% MbetaCD to deliver oleic acid did not affect cell viability, in contrast NGFDPC12 cultures in which 0.25% MbetaCD concentration is used exhibited similar loss of cell viability as observed with 0.25% MbetaCD alone. Treating these cultures with caspase-3 inhibitor z-VAD-fmk did not protect the cells from MbetaCD toxic effects. (4) Immortalized Schwann cells (iSC) exposed to MbetaCD 0.12% did not show loss of cell viability while 0.25% MbetaCD triggered a significant toxicity but with a different dose and time course dynamic than NGFDPC12 cells. Thus, NGFDPC12 or iSC cell cultures exposed to 0.12% MbetaCD exhibits normal viability while higher concentrations increase in cell death and apoptosis.
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Affiliation(s)
| | | | | | | | | | - Marino De Leon
- *Corresponding author address: Center for Health Disparities and Molecular Medicine, 142 Mortensen Hall, 11085 Campus Street, Loma Linda University, School of Medicine, Loma Linda CA, 92350. Tel: 909–558–8777. Fax: 909–558–0177.
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