1
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Mistry H, Richardson CD, Higginbottom A, Ashford B, Ahamed SU, Moore Z, Matthews FE, Brayne C, Simpson JE, Wharton SB. Relationships of brain cholesterol and cholesterol biosynthetic enzymes to Alzheimer's pathology and dementia in the CFAS population-derived neuropathology cohort. Neurosci Res 2024; 204:22-33. [PMID: 38278219 PMCID: PMC11192635 DOI: 10.1016/j.neures.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 01/05/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024]
Abstract
Altered cholesterol metabolism is implicated in brain ageing and Alzheimer's disease. We examined whether key genes regulating cholesterol metabolism and levels of brain cholesterol are altered in dementia and Alzheimer's disease neuropathological change (ADNC). Temporal cortex (n = 99) was obtained from the Cognitive Function and Ageing Study. Expression of the cholesterol biosynthesis rate-limiting enzyme HMG-CoA reductase (HMGCR) and its regulator, SREBP2, were detected using immunohistochemistry. Expression of HMGCR, SREBP2, CYP46A1 and ABCA1 were quantified by qPCR in samples enriched for astrocyte and neuronal RNA following laser-capture microdissection. Total cortical cholesterol was measured using the Amplex Red assay. HMGCR and SREBP2 proteins were predominantly expressed in pyramidal neurones, and in glia. Neuronal HMGCR did not vary with ADNC, oxidative stress, neuroinflammation or dementia status. Expression of HMGCR neuronal mRNA decreased with ADNC (p = 0.022) and increased with neuronal DNA damage (p = 0.049), whilst SREBP2 increased with ADNC (p = 0.005). High or moderate tertiles for cholesterol levels were associated with increased dementia risk (OR 1.44, 1.58). APOE ε4 allele was not associated with cortical cholesterol levels. ADNC is associated with gene expression changes that may impair cholesterol biosynthesis in neurones but not astrocytes, whilst levels of cortical cholesterol show a weak relationship to dementia status.
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Affiliation(s)
- Hemant Mistry
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | | | - Adrian Higginbottom
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Bridget Ashford
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Saif U Ahamed
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Zoe Moore
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | | | - Carol Brayne
- Cambridge Public Health, University of Cambridge, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, and the Neuroscience Institute, the University of Sheffield, UK.
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2
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Zhang JL, Lv M, Yang CF, Zhu YX, Li CJ. Mevalonate pathway and male reproductive aging. Mol Reprod Dev 2023; 90:774-781. [PMID: 37733694 DOI: 10.1002/mrd.23705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 08/27/2023] [Accepted: 09/08/2023] [Indexed: 09/23/2023]
Abstract
Male fertility declines with age. The mevalonate pathway, through which cholesterol and nonsteroidal isoprenoids are synthesized, plays key role in metabolic processes and is an essential pathway for cholesterol production and protein prenylation. Male reproductive aging is accompanied by dramatic changes in the metabolic microenvironment of the testis. Since the mevalonate pathway has an important role in spermatogenesis, we attempted to explore the association between male reproductive aging and the mevalonate pathway to explain the mechanism of male reproductive aging. Alterations in the mevalonate pathway may affect male reproductive aging by decreasing cholesterol synthesis and altering testis protein prenylation. Decreased cholesterol levels affect cholesterol modification, testosterone production, and remodeling of germ cell membranes. Aging-related metabolic disorders also affect the metabolic coupling between somatic cells and spermatogenic cells, leading to male fertility decline. Therefore, we hypothesized that alterations in the mevalonate pathway represent one of the metabolic causes of reproductive aging.
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Affiliation(s)
- Jia-Le Zhang
- State Key Laboratory of Reproductive Medicine and China International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Meng Lv
- State Key Laboratory of Reproductive Medicine and China International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Chao-Fan Yang
- State Key Laboratory of Reproductive Medicine and China International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Ying-Xi Zhu
- State Key Laboratory of Reproductive Medicine and China International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Chao-Jun Li
- State Key Laboratory of Reproductive Medicine and China International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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3
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Cell extraction method coupled with LC-QTOF MS/MS analysis for predicting neuroprotective compounds from Polygonum tinctorium. J Pharm Biomed Anal 2022; 220:114988. [PMID: 35994944 DOI: 10.1016/j.jpba.2022.114988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/07/2022] [Accepted: 08/06/2022] [Indexed: 11/24/2022]
Abstract
The cell extraction method coupled with LC-QTOF-MS/MS is a biological screening technique in which cells are incubated with extracts of natural products, which results in potential bioactive compounds selectively combining with various extracellular and intracellular targets. Although the neuroprotective effects of the plant Polygonum tinctorium are unknown, the ethyl acetate (EtOAc) fraction exhibits significant neuroprotective effects against ʟ-glutamate-induced cytotoxicity in HT22 cells. In this study, we attempted to identify the neuroprotective compounds in the EtOAc fraction of P. tinctorium using the cell extraction method coupled with LC-QTOF MS/MS. Potential neuroprotective components derived from P. tinctorium were combined selectively with HT22 cells, and cell-derived metabolites were identified. A new flavonoid compound, 3,5,3',4'-tetrahydroxy-6,7-methylendioxyflavone-3-O-β-ᴅ-glucopyranoside (1), and 14 known compounds (2-15), with compounds 2, 3, 8, 13, and 15 detected by the cell extraction method, were isolated from the EtOAc fraction of P. tinctorium. Compounds 2, 8, 12, and 14 showed strong neuroprotective effects, with compounds 2 and 14 identified in this plant for the first time in this study. Our results indicate that the cell extraction method coupled with LC-QTOF MS/MS is a useful tool for screening and identifying neuroprotective compounds in natural products.
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Saputra WD, Shono H, Ohsaki Y, Sultana H, Komai M, Shirakawa H. Geranylgeraniol Inhibits Lipopolysaccharide-Induced Inflammation in Mouse-Derived MG6 Microglial Cells via NF-κB Signaling Modulation. Int J Mol Sci 2021; 22:ijms221910543. [PMID: 34638882 PMCID: PMC8508820 DOI: 10.3390/ijms221910543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/25/2021] [Accepted: 09/25/2021] [Indexed: 12/18/2022] Open
Abstract
Persistent inflammatory reactions in microglial cells are strongly associated with neurodegenerative pathogenesis. Additionally, geranylgeraniol (GGOH), a plant-derived isoprenoid, has been found to improve inflammatory conditions in several animal models. It has also been observed that its chemical structure is similar to that of the side chain of menaquinone-4, which is a vitamin K2 sub-type that suppresses inflammation in mouse-derived microglial cells. In this study, we investigated whether GGOH has a similar anti-inflammatory effect in activated microglial cells. Particularly, mouse-derived MG6 cells pre-treated with GGOH were exposed to lipopolysaccharide (LPS). Thereafter, the mRNA levels of pro-inflammatory cytokines were determined via qRT-PCR, while protein expression levels, especially the expression of NF-κB signaling cascade-related proteins, were determined via Western blot analysis. The distribution of NF-κB p65 protein was also analyzed via fluorescence microscopy. Thus, it was observed that GGOH dose-dependently suppressed the LPS-induced increase in the mRNA levels of Il-1β, Tnf-α, Il-6, and Cox-2. Furthermore, GGOH inhibited the phosphorylation of TAK1, IKKα/β, and NF-κB p65 proteins as well as NF-κB nuclear translocation induced by LPS while maintaining IκBα expression. We showed that GGOH, similar to menaquinone-4, could alleviate LPS-induced microglial inflammation by targeting the NF-kB signaling pathway.
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Affiliation(s)
- Wahyu Dwi Saputra
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan; (W.D.S.); (H.S.); (Y.O.); (H.S.); (M.K.)
| | - Hiroki Shono
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan; (W.D.S.); (H.S.); (Y.O.); (H.S.); (M.K.)
| | - Yusuke Ohsaki
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan; (W.D.S.); (H.S.); (Y.O.); (H.S.); (M.K.)
- International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan
| | - Halima Sultana
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan; (W.D.S.); (H.S.); (Y.O.); (H.S.); (M.K.)
| | - Michio Komai
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan; (W.D.S.); (H.S.); (Y.O.); (H.S.); (M.K.)
| | - Hitoshi Shirakawa
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan; (W.D.S.); (H.S.); (Y.O.); (H.S.); (M.K.)
- International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan
- Correspondence: ; Tel.: +81-22-757-4402
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5
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Ötzkan S, Muller WE, Gibson Wood W, Eckert GP. Effects of 7,8-Dihydroxyflavone on Lipid Isoprenoid and Rho Protein Levels in Brains of Aged C57BL/6 Mice. Neuromolecular Med 2020; 23:130-139. [PMID: 33377988 PMCID: PMC7929957 DOI: 10.1007/s12017-020-08640-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022]
Abstract
Synaptic impairment may be the main cause of cognitive dysfunction in brain aging that is probably due to a reduction in synaptic contact between the axonal buttons and dendritic spines. Rho proteins including the small GTPase Rac1 have become key regulators of neuronal morphogenesis that supports synaptic plasticity. Small Rho- and Ras-GTPases are post-translationally modified by the isoprenoids geranylgeranyl pyrophosphate (GGPP) and farnesyl pyrophosphate (FPP), respectively. For all GTPases, anchoring in the plasma membrane is essential for their activation by guanine nucleotide exchange factors (GEFs). Rac1-specific GEFs include the protein T lymphoma invasion and metastasis 1 (Tiam1). Tiam1 interacts with the TrkB receptor to mediate the brain-derived neurotrophic factor (BDNF)-induced activation of Rac1, resulting in cytoskeletal rearrangement and changes in cellular morphology. The flavonoid 7,8-dihydroxyflavone (7,8-DHF) acts as a highly affine-selective TrkB receptor agonist and causes the dimerization and autophosphorylation of the TrkB receptor and thus the activation of downstream signaling pathways. In the current study, we investigated the effects of 7,8-DHF on cerebral lipid isoprenoid and Rho protein levels in male C57BL/6 mice aged 3 and 23 months. Aged mice were daily treated with 100 mg/kg b.w. 7,8-DHF by oral gavage for 21 days. FPP, GGPP, and cholesterol levels were determined in brain tissue. In the same tissue, the protein content of Tiam1 and TrkB in was measured. The cellular localization of the small Rho-GTPase Rac1 and small Rab-GTPase Rab3A was studied in total brain homogenates and membrane preparations. We report the novel finding that 7,8-DHF restored levels of the Rho proteins Rac1 and Rab3A in membrane preparations isolated from brains of treated aged mice. The selective TrkB agonist 7,8-DHF did not affect BDNF and TrkB levels, but restored Tiam1 levels that were found to be reduced in brains of aged mice. FPP, GGPP, and cholesterol levels were significantly elevated in brains of aged mice but not changed by 7,8-DHF treatment. Hence, 7,8-DHF may be useful as pharmacological tool to treat age-related cognitive dysfunction although the underlying mechanisms need to be elucidated in detail.
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Affiliation(s)
- Sarah Ötzkan
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Goethe-University, Max-von-Laue-St. 9, 60438, Frankfurt, Germany
| | - Walter E Muller
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Goethe-University, Max-von-Laue-St. 9, 60438, Frankfurt, Germany
| | - W Gibson Wood
- Department of Pharmacology, Geriatric Research, Education and Clinical Center, University of Minnesota School of Medicine, VAMC, Minneapolis, MN, 55417, USA
| | - Gunter P Eckert
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Goethe-University, Max-von-Laue-St. 9, 60438, Frankfurt, Germany.
- Institute of Nutritional Sciences, Laboratory for Nutrition in Prevention and Therapy, Justus-Liebig-University of Giessen, Biomedical Research Center Seltersberg (BFS), Schubertstr. 81, 35392, Giessen, Germany.
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6
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Reddy JM, Raut NGR, Seifert JL, Hynds DL. Regulation of Small GTPase Prenylation in the Nervous System. Mol Neurobiol 2020; 57:2220-2231. [PMID: 31989383 DOI: 10.1007/s12035-020-01870-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 01/06/2020] [Indexed: 11/26/2022]
Abstract
Mevalonate pathway inhibitors have been extensively studied for their roles in cholesterol depletion and for inhibiting the prenylation and activation of various proteins. Inhibition of protein prenylation has potential therapeutic uses against neurological disorders, like neural cancers, neurodegeneration, and neurotramatic lesions. Protection against neurodegeneration and promotion of neuronal regeneration is regulated in large part by Ras superfamily small guanosine triphosphatases (GTPases), particularly the Ras, Rho, and Rab subfamilies. These proteins are prenylated to target them to cellular membranes. Prenylation can be specifically inhibited through altering the function of enzymes of the mevalonate pathway necessary for isoprenoid production and attachment to target proteins to elicit a variety of effects on neural cells. However, this approach does not address how prenylation affects a specific protein. This review focuses on the regulation of small GTPase prenylation, the different techniques to inhibit prenylation, and how this inhibition has affected neural cell processes.
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Affiliation(s)
| | | | | | - DiAnna L Hynds
- Texas Woman's University, Denton, TX, USA.
- Woodcock Institute for the Advancement of Neurocognitive Research and Applied Practice, Texas Woman's University, PO Box 4525799, Denton, TX, 76204-5799, USA.
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7
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Waller DD, Park J, Tsantrizos YS. Inhibition of farnesyl pyrophosphate (FPP) and/or geranylgeranyl pyrophosphate (GGPP) biosynthesis and its implication in the treatment of cancers. Crit Rev Biochem Mol Biol 2019; 54:41-60. [DOI: 10.1080/10409238.2019.1568964] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | - Jaeok Park
- Department of Chemistry, McGill University, Montreal, Canada
- Department of Biochemistry, McGill University, Montreal, Canada
| | - Youla S. Tsantrizos
- Department of Chemistry, McGill University, Montreal, Canada
- Department of Biochemistry, McGill University, Montreal, Canada
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8
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Chhonker YS, Haney SL, Bala V, Holstein SA, Murry DJ. Simultaneous Quantitation of Isoprenoid Pyrophosphates in Plasma and Cancer Cells Using LC-MS/MS. Molecules 2018; 23:molecules23123275. [PMID: 30544938 PMCID: PMC6321327 DOI: 10.3390/molecules23123275] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/07/2018] [Accepted: 12/07/2018] [Indexed: 11/16/2022] Open
Abstract
Isoprenoids (IsoP) are an important class of molecules involved in many different cellular processes including cholesterol synthesis. We have developed a sensitive and specific LC-MS/MS method for the quantitation of three key IsoPs in bio-matrices, geranyl pyrophosphate (GPP), farnesyl pyrophosphate (FPP), and geranylgeranyl pyrophosphate (GGPP). LC-MS/MS analysis was performed using a Nexera UPLC System connected to a LCMS-8060 (Shimadzu Scientific Instruments, Columbia, MD) with a dual ion source. The electrospray ionization source was operated in the negative MRM mode. The chromatographic separation and detection of analytes was achieved on a reversed phase ACCQ-TAG Ultra C18 (1.7 µm, 100 mm × 2.1 mm I.D.) column. The mobile phase consisted of (1) a 10 mM ammonium carbonate with 0.1% ammonium hydroxide in water, and (2) a 0.1% ammonium hydroxide in acetonitrile/methanol (75/25). The flow rate was set to 0.25 mL/min in a gradient condition. The limit of quantification was 0.04 ng/mL for all analytes with a correlation coefficient (r2) of 0.998 or better and a total run time of 12 min. The inter- and intra-day accuracy (85–115%) precision (<15%), and recovery (40–90%) values met the acceptance criteria. The validated method was successfully applied to quantitate basal concentrations of GPP, FPP and GGPP in human plasma and in cultured cancer cell lines. Our LC-MS/MS method may be used for IsoP quantification in different bio-fluids and to further investigate the role of these compounds in various physiological processes.
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Affiliation(s)
- Yashpal S Chhonker
- Department of Pharmacy Practice, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Staci L Haney
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Veenu Bala
- Department of Pharmaceutical Sciences, Mohanlal Sukhadia University, Udaipur, Rajasthan 313001, India.
| | - Sarah A Holstein
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Daryl J Murry
- Department of Pharmacy Practice, University of Nebraska Medical Center, Omaha, NE 68198, USA.
- Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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9
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Pelleieux S, Picard C, Lamarre-Théroux L, Dea D, Leduc V, Tsantrizos YS, Poirier J. Isoprenoids and tau pathology in sporadic Alzheimer's disease. Neurobiol Aging 2018; 65:132-139. [PMID: 29476987 DOI: 10.1016/j.neurobiolaging.2018.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/07/2017] [Accepted: 01/21/2018] [Indexed: 12/12/2022]
Abstract
The mevalonate pathway has been described to play a key role in Alzheimer's disease (AD) physiopathology. Farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) are nonsterol isoprenoids derived from mevalonate, which serve as precursors to numerous human metabolites. They facilitate protein prenylation; hFPP and hGGPP synthases act as gateway enzymes to the prenylation of the small guanosine triphosphate (GTP)ase proteins such as RhoA and cdc42 that have been shown to facilitate phospho-tau (p-Tau, i.e., protein tau phosphorylated) production in the brain. In this study, a significant positive correlation was observed between the synthases mRNA prevalence and disease status (FPPS, p < 0.001, n = 123; GGPPS, p < 0.001, n = 122). The levels of mRNA for hFPPS and hGGPPS were found to significantly correlate with the amount of p-Tau protein levels (p < 0.05, n = 34) and neurofibrillary tangle density (p < 0.05, n = 39) in the frontal cortex. Interestingly, high levels of hFPPS and hGGPPS mRNA prevalence are associated with earlier age of onset in AD (p < 0.05, n = 58). Together, these results suggest that accumulation of p-Tau in the AD brain is related, at least in part, to increased levels of neuronal isoprenoids.
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Affiliation(s)
- Sandra Pelleieux
- Douglas Mental Health University Institute, McGill University, Montreal, Canada
| | - Cynthia Picard
- Douglas Mental Health University Institute, McGill University, Montreal, Canada; Center for Studies on the Prevention of Alzheimer's Disease, McGill University, Montreal, Canada
| | | | - Doris Dea
- Douglas Mental Health University Institute, McGill University, Montreal, Canada
| | - Valérie Leduc
- Douglas Mental Health University Institute, McGill University, Montreal, Canada
| | - Youla S Tsantrizos
- Department of Chemistry, McGill University, Montreal, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Judes Poirier
- Douglas Mental Health University Institute, McGill University, Montreal, Canada; Center for Studies on the Prevention of Alzheimer's Disease, McGill University, Montreal, Canada.
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10
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Palsuledesai CC, Ochocki JD, Kuhns MM, Wang YC, Warmka JK, Chernick DS, Wattenberg EV, Li L, Arriaga EA, Distefano MD. Metabolic Labeling with an Alkyne-modified Isoprenoid Analog Facilitates Imaging and Quantification of the Prenylome in Cells. ACS Chem Biol 2016; 11:2820-2828. [PMID: 27525511 PMCID: PMC5074897 DOI: 10.1021/acschembio.6b00421] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Protein prenylation is a post-translational modification that is responsible for membrane association and protein-protein interactions. The oncogenic protein Ras, which is prenylated, has been the subject of intense study in the past 20 years as a therapeutic target. Several studies have shown a correlation between neurodegenerative diseases including Alzheimer's disease and Parkinson's disease and protein prenylation. Here, a method for imaging and quantification of the prenylome using microscopy and flow cytometry is described. We show that metabolically incorporating an alkyne isoprenoid into mammalian cells, followed by a Cu(I)-catalyzed alkyne azide cycloaddition reaction to a fluorophore, allows for detection of prenylated proteins in several cell lines and that different cell types vary significantly in their levels of prenylated proteins. The addition of a prenyltransferase inhibitor or the precursors to the native isoprenoid substrates lowers the levels of labeled prenylated proteins. Finally, we demonstrate that there is a significantly higher (22%) level of prenylated proteins in a cellular model of compromised autophagy as compared to normal cells, supporting the hypothesis of a potential involvement of protein prenylation in abrogated autophagy. These results highlight the utility of total prenylome labeling for studies on the role of protein prenylation in various diseases including aging-related disorders.
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Affiliation(s)
- Charuta C. Palsuledesai
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Joshua D. Ochocki
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Michelle M. Kuhns
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Yen-Chih Wang
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Janel K. Warmka
- Division
of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Dustin S. Chernick
- Department
of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Elizabeth V. Wattenberg
- Division
of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ling Li
- Department
of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Edgar A. Arriaga
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mark D. Distefano
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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11
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Ostrowski SM, Johnson K, Siefert M, Shank S, Sironi L, Wolozin B, Landreth GE, Ziady AG. Simvastatin inhibits protein isoprenylation in the brain. Neuroscience 2016; 329:264-74. [PMID: 27180285 DOI: 10.1016/j.neuroscience.2016.04.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 04/14/2016] [Accepted: 04/30/2016] [Indexed: 10/25/2022]
Abstract
Evidence suggests that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, may reduce the risk of Alzheimer's disease (AD). Statin action in patients with AD, as in those with heart disease, is likely to be at least partly independent of the effects of statins on cholesterol. Statins can alter cellular signaling and protein trafficking through inhibition of isoprenylation of Rho, Cdc42, and Rab family GTPases. The effects of statins on protein isoprenylation in vivo, particularly in the central nervous system, are poorly studied. We utilized two-dimensional gel electrophoresis approaches to directly monitor the levels of isoprenylated and non-isoprenylated forms of Rho and Rab family GTPases. We report that simvastatin significantly inhibits RhoA and Rab4, and Rab6 isoprenylation at doses as low as 50nM in vitro. We also provide the first in vivo evidence that statins inhibit the isoprenylation of RhoA in the brains of rats and RhoA, Cdc42, and H-Ras in the brains of mice treated with clinically relevant doses of simvastatin.
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Affiliation(s)
- Stephen M Ostrowski
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Kachael Johnson
- Department of Pediatrics, Emory University, Atlanta, GA, USA; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Matthew Siefert
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Sam Shank
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Luigi Sironi
- Department of Pharmacological and Biomolecular Sciences, University of Milan, and Centro Cardiologico Monzino, Milan, Italy
| | - Benjamin Wolozin
- Departments of Pharmacology and Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Gary E Landreth
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Assem G Ziady
- Department of Pediatrics, Emory University, Atlanta, GA, USA; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA.
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12
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Ling Q, Tejada-Simon MV. Statins and the brain: New perspective for old drugs. Prog Neuropsychopharmacol Biol Psychiatry 2016; 66:80-86. [PMID: 26655447 DOI: 10.1016/j.pnpbp.2015.11.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/15/2015] [Accepted: 11/25/2015] [Indexed: 12/22/2022]
Abstract
Statins are one of the most popular lipid-lowering drugs (LLDs). Upon oral administration, these drugs are well absorbed by the intestine and effectively used for the treatment of dyslipidemias. Recently, statins are becoming also well-known for their cholesterol-independent effects and their potential use in brain diseases and different types of cancers. While still controversial, recent research has suggested that statin's cholesterol-independent activities work possibly through alterations on isoprenoid levels. This reduction of isoprenoids in the central nervous system might result in effective biochemical and behavioral improvements on certain neurological disorders. This manuscript aims to highlight current research describing the use of statin therapy in the brain and discuss whether statins might affect neuronal dynamics and function independently of their cholesterol regulatory role.
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Affiliation(s)
- Q Ling
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX, USA
| | - M V Tejada-Simon
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX, USA; Department of Biology, University of Houston, Houston, TX, USA; Department of Psychology, University of Houston, Houston, TX, USA; Biology of Behavior Institute (BoBI), University of Houston, Houston, TX, USA.
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13
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Gao S, Yu R, Zhou X. The Role of Geranylgeranyltransferase I-Mediated Protein Prenylation in the Brain. Mol Neurobiol 2015; 53:6925-6937. [DOI: 10.1007/s12035-015-9594-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 12/01/2015] [Indexed: 10/22/2022]
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14
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Hynds DL. Subcellular localization of Rho GTPases: implications for axon regeneration. Neural Regen Res 2015; 10:1032-3. [PMID: 26330813 PMCID: PMC4541221 DOI: 10.4103/1673-5374.160064] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2015] [Indexed: 11/20/2022] Open
Affiliation(s)
- DiAnna L Hynds
- Department of Biology, Texas Woman's University, Denton, TX, USA
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15
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Park J, Matralis AN, Berghuis AM, Tsantrizos YS. Human isoprenoid synthase enzymes as therapeutic targets. Front Chem 2014; 2:50. [PMID: 25101260 PMCID: PMC4106277 DOI: 10.3389/fchem.2014.00050] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 06/25/2014] [Indexed: 12/14/2022] Open
Abstract
In the human body, the complex biochemical network known as the mevalonate pathway is responsible for the biosynthesis of all isoprenoids, which consists of a vast array of metabolites that are vital for proper cellular functions. Two key isoprenoids, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) are responsible for the post-translational prenylation of small GTP-binding proteins, and serve as the biosynthetic precursors to numerous other biomolecules. The down-stream metabolite of FPP and GGPP is squalene, the precursor to steroids, bile acids, lipoproteins, and vitamin D. In the past, interest in prenyl synthase inhibitors focused mainly on the role of the FPP in lytic bone diseases. More recently pre-clinical and clinical studies have strongly implicated high levels of protein prenylation in a plethora of human diseases, including non-skeletal cancers, the progression of neurodegenerative diseases and cardiovascular diseases. In this review, we focus mainly on the potential therapeutic value of down-regulating the biosynthesis of FPP, GGPP, and squalene. We summarize the most recent drug discovery efforts and the structural data available that support the current on-going studies.
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Affiliation(s)
- Jaeok Park
- Department of Biochemistry, McGill University Montreal, QC, Canada
| | | | - Albert M Berghuis
- Department of Biochemistry, McGill University Montreal, QC, Canada ; Department of Microbiology and Immunology, McGill University Montreal, QC, Canada
| | - Youla S Tsantrizos
- Department of Biochemistry, McGill University Montreal, QC, Canada ; Department of Chemistry, McGill University Montreal, QC, Canada
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16
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Wood WG, Li L, Müller WE, Eckert GP. Cholesterol as a causative factor in Alzheimer's disease: a debatable hypothesis. J Neurochem 2014; 129:559-72. [PMID: 24329875 PMCID: PMC3999290 DOI: 10.1111/jnc.12637] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/24/2013] [Accepted: 12/09/2013] [Indexed: 12/17/2022]
Abstract
High serum/plasma cholesterol levels have been suggested as a risk factor for Alzheimer's disease (AD). Some reports, mostly retrospective epidemiological studies, have observed a decreased prevalence of AD in patients taking the cholesterol lowering drugs, statins. The strongest evidence causally linking cholesterol to AD is provided by experimental studies showing that adding/reducing cholesterol alters amyloid precursor protein (APP) and amyloid beta-protein (Ab) levels. However, there are problems with the cholesterol-AD hypothesis. Cholesterol levels in serum/plasma and brain of AD patients do not support cholesterol as a causative factor in AD.Prospective studies on statins and AD have largely failed to show efficacy. Even the experimental data are open to interpretation given that it is well-established that modification of cholesterol levels has effects on multiple proteins, not only amyloid precursor protein and Ab. The purpose of this review, therefore, was to examine the above-mentioned issues, discuss the pros and cons of the cholesterol-AD hypothesis, involvement of other lipids in the mevalonate pathway, and consider that AD may impact cholesterol homeostasis.
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Affiliation(s)
- W. Gibson Wood
- Geriatric Research, Education and Clinical Center, VAMC, Department of Pharmacology, University of Minnesota School of Medicine, Minneapolis, MN 55455 USA
| | - Ling Li
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455 USA
| | - Walter E. Müller
- Department of Pharmacology, Biocenter Niederursel, Goethe University, Max-von-Laue-St. 9, 60438 Frankfurt, Germany
| | - Gunter P. Eckert
- Department of Pharmacology, Biocenter Niederursel, Goethe University, Max-von-Laue-St. 9, 60438 Frankfurt, Germany
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17
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Afshordel S, Wood WG, Igbavboa U, Muller WE, Eckert GP. Impaired geranylgeranyltransferase-I regulation reduces membrane-associated Rho protein levels in aged mouse brain. J Neurochem 2014; 129:732-42. [PMID: 24428713 PMCID: PMC3999261 DOI: 10.1111/jnc.12654] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/09/2014] [Accepted: 01/10/2014] [Indexed: 12/21/2022]
Abstract
Synaptic impairment rather than neuronal loss may be the leading cause of cognitive dysfunction in brain aging. Certain small Rho-GTPases are involved in synaptic plasticity, and their dysfunction is associated with brain aging and neurodegeneration. Rho-GTPases undergo prenylation by attachment of geranylgeranylpyrophosphate (GGPP) catalyzed by GGTase-I. We examined age-related changes in the abundance of Rho and Rab proteins in membrane and cytosolic fractions as well as of GGTase-I in brain tissue of 3- and 23-month-old C57BL/6 mice. We report a shift in the cellular localization of Rho-GTPases toward reduced levels of membrane-associated and enhanced cytosolic levels of those proteins in aged mouse brain as compared with younger mice. The age-related reduction in membrane-associated Rho proteins was associated with a reduction in GGTase-Iβ levels that regulates binding of GGPP to Rho-GTPases. Proteins prenylated by GGTase-II were not reduced in aged brain indicating a specific targeting of GGTase-I in the aged brain. Inhibition of GGTase-I in vitro modeled the effects of aging we observed in vivo. We demonstrate for the first time a decrease in membrane-associated Rho proteins in aged brain in association with down-regulation of GGTase-Iβ. This down-regulation could be one of the mechanisms causing age-related weakening of synaptic plasticity.
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Affiliation(s)
- Sarah Afshordel
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Max-von-Laue-St. 9, 60438 Frankfurt, Germany
| | - W. Gibson Wood
- Department of Pharmacology, University of Minnesota School of Medicine, Geriatric Research, Education and Clinical Center, VAMC, Minneapolis, MN 55417 USA
| | - Urule Igbavboa
- Department of Pharmacology, University of Minnesota School of Medicine, Geriatric Research, Education and Clinical Center, VAMC, Minneapolis, MN 55417 USA
| | - Walter E. Muller
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Max-von-Laue-St. 9, 60438 Frankfurt, Germany
| | - Gunter P. Eckert
- Department of Pharmacology, Biocenter Niederursel, University of Frankfurt, Max-von-Laue-St. 9, 60438 Frankfurt, Germany
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18
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Inhibiting geranylgeranylation increases neurite branching and differentially activates cofilin in cell bodies and growth cones. Mol Neurobiol 2014; 50:49-59. [PMID: 24515839 DOI: 10.1007/s12035-014-8653-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/23/2014] [Indexed: 10/25/2022]
Abstract
Inhibitors of the mevalonate pathway, including the highly prescribed statins, reduce the production of cholesterol and isoprenoids such as geranylgeranyl pyrophosphates. The Rho family of small guanine triphosphatases (GTPases) requires isoprenylation, specifically geranylgeranylation, for activation. Because Rho GTPases are primary regulators of actin filament rearrangements required for process extension, neurite arborization, and synaptic plasticity, statins may affect cognition or recovery from nervous system injury. Here, we assessed how manipulating geranylgeranylation affects neurite initiation, elongation, and branching in neuroblastoma growth cones. Treatment with the statin, lovastatin (20 μM), decreased measures of neurite initiation by 17.0 to 19.0 % when a source of cholesterol was present and increased neurite branching by 4.03- to 9.54-fold (regardless of exogenous cholesterol). Neurite elongation was increased by treatment with lovastatin only in cholesterol-free culture conditions. Treatment with lovastatin decreased growth cone actin filament content by up to 24.3 %. In all cases, co-treatment with the prenylation precursor, geranylgeraniol (10 μM), reversed the effect of lovastatin. In a prior work, statin effects on outgrowth were linked to modulating the actin depolymerizing factor, cofilin. In our assays, treatment with lovastatin or geranylgeraniol decreased cofilin phosphorylation in whole cell lysates. However, lovastatin increased cofilin phosphorylation in cell bodies and decreased it in growth cones, indicating differential regulation in specific cell regions. Together, we interpret these data to suggest that protein geranylgeranylation likely regulates growth cone actin filament content and subsequent neurite outgrowth through mechanisms that also affect actin nucleation and polymerization.
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Simvastatin promotes adult hippocampal neurogenesis by enhancing Wnt/β-catenin signaling. Stem Cell Reports 2013; 2:9-17. [PMID: 24511465 PMCID: PMC3916759 DOI: 10.1016/j.stemcr.2013.11.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 11/05/2013] [Accepted: 11/06/2013] [Indexed: 02/01/2023] Open
Abstract
Statins improve recovery from traumatic brain injury and show promise in preventing Alzheimer disease. However, the mechanisms by which statins may be therapeutic for neurological conditions are not fully understood. In this study, we present the initial evidence that oral administration of simvastatin in mice enhances Wnt signaling in vivo. Concomitantly, simvastatin enhances neurogenesis in cultured adult neural progenitor cells as well as in the dentate gyrus of adult mice. Finally, we find that statins enhance Wnt signaling through regulation of isoprenoid synthesis and not through cholesterol. These findings provide direct evidence that Wnt signaling is enhanced in vivo by simvastatin and that this elevation of Wnt signaling is required for the neurogenic effects of simvastatin. Collectively, these data add to the growing body of evidence that statins may have therapeutic value for treating certain neurological disorders.
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20
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Yang C, Madonna R, Li Y, Zhang Q, Shen WF, McNamara K, Yang YJ, Geng YJ. Simvastatin-enhanced expression of promyogenic nuclear factors and cardiomyogenesis of murine embryonic stem cells. Vascul Pharmacol 2013; 60:8-16. [PMID: 24200505 DOI: 10.1016/j.vph.2013.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 09/30/2013] [Accepted: 10/28/2013] [Indexed: 12/24/2022]
Abstract
A combination of statin and stem cell therapies has been shown to benefit in experimental models of myocardial infarction. This study tests whether treatment with simvastatin has a direct impact on the cardiomyogenic development of murine embryonic stem cells (ESCs) in embryoid bodies. In a concentration-dependent manner, simvastatin treatment enhanced expression of several promyogenic nuclear transcription factors, including GATA4, Nkx2.5, DTEF-1 and myocardin A. The statin-treated cells also displayed higher levels of cardiac proteins, including myosin, α-actinin, Ryanodine receptor-2, and atrial natriuretic peptide, and they developed synchronized contraction. The statin's promyogenic effect was partially diminished by the addition of the two isoprenoids FPP and GGPP, which are intermediates of cholesterol synthesis. Thus, simvastatin treatment enhances ESC myogenesis during early development perhaps via a mechanism inhibiting the mevalonate-FPP/GGPP pathway.
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Affiliation(s)
- ChenMin Yang
- The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Medical School at Houston, Houston, TX USA; The Department of Obstetrics and Gynecology, Ruijin Hospital, Jiao-Tong University Medical School, Shanghai, China; Texas Heart Institute, Houston, TX, USA
| | - Rosalinda Madonna
- The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Medical School at Houston, Houston, TX USA; Texas Heart Institute, Houston, TX, USA
| | - Yangxin Li
- The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Medical School at Houston, Houston, TX USA; Texas Heart Institute, Houston, TX, USA
| | - Qi Zhang
- The Department of Cardiovascular Medicine, Ruijin Hospital, Jiao-Tong University Medical School, Shanghai, China
| | - Wei-Feng Shen
- The Department of Cardiovascular Medicine, Ruijin Hospital, Jiao-Tong University Medical School, Shanghai, China
| | - Katharine McNamara
- The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Medical School at Houston, Houston, TX USA; Texas Heart Institute, Houston, TX, USA
| | - Yue-Jin Yang
- FuWai Cardiovascular Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yong-Jian Geng
- The Center for Cardiovascular Biology and Atherosclerosis Research, The University of Texas Medical School at Houston, Houston, TX USA; Texas Heart Institute, Houston, TX, USA.
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Smiljanic K, Vanmierlo T, Djordjevic AM, Perovic M, Loncarevic-Vasiljkovic N, Tesic V, Rakic L, Ruzdijic S, Lutjohann D, Kanazir S. Aging induces tissue-specific changes in cholesterol metabolism in rat brain and liver. Lipids 2013; 48:1069-77. [PMID: 24057446 DOI: 10.1007/s11745-013-3836-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/22/2013] [Indexed: 11/26/2022]
Abstract
Disturbance of cholesterol homeostasis in the brain is coupled to age-related brain dysfunction. In the present work, we studied the relationship between aging and cholesterol metabolism in two brain regions, the cortex and hippocampus, as well as in the sera and liver of 6-, 12-, 18- and 24-month-old male Wistar rats. Using gas chromatography-mass spectrometry, we undertook a comparative analysis of the concentrations of cholesterol, its precursors and metabolites, as well as dietary-derived phytosterols. During aging, the concentrations of the three cholesterol precursors examined (lanosterol, lathosterol and desmosterol) were unchanged in the cortex, except for desmosterol which decreased (44 %) in 18-month-old rats. In the hippocampus, aging was associated with a significant reduction in lanosterol and lathosterol concentrations at 24 months (28 and 25 %, respectively), as well as by a significant decrease of desmosterol concentration at 18 and 24 months (36 and 51 %, respectively). In contrast, in the liver we detected age-induced increases in lanosterol and lathosterol concentrations, and no change in desmosterol concentration. The amounts of these sterols were lower than in the brain regions. In the cortex and hippocampus, desmosterol was the predominant cholesterol precursor. In the liver, lathosterol was the most abundant precursor. This ratio remained stable during aging. The most striking effect of aging observed in our study was a significant decrease in desmosterol concentration in the hippocampus which could reflect age-related reduced synaptic plasticity, thus representing one of the detrimental effects of advanced age.
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Affiliation(s)
- Kosara Smiljanic
- Laboratory of Molecular Neurobiology, Department of Neurobiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia
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Raina V, Gupta S, Yadav S, Surolia A. Simvastatin induced neurite outgrowth unveils role of cell surface cholesterol and acetyl CoA carboxylase in SH-SY5Y cells. PLoS One 2013; 8:e74547. [PMID: 24040277 PMCID: PMC3770597 DOI: 10.1371/journal.pone.0074547] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 08/02/2013] [Indexed: 01/08/2023] Open
Abstract
Statins are known to modulate cell surface cholesterol (CSC) and AMP-activated protein kinase (AMPK) in non-neural cells; however no study demonstrates whether CSC and AMPK may regulate simvastatin induced neuritogenesis (SIN). We found that simvastatin (SIM) maintains CSC as shown by Fillipin III staining, Flotillin-2 protein expression / localization and phosphorylation of various receptor tyrosine kinases (RTKs) in the plasma membrane. Modulation of CSC revealed that SIN is critically dependent on this CSC. Simultaneously, phospho array for mitogen activated protein kinases (MAPKs) revealed PI3K / Akt as intracellular pathway which modulates lipid pathway by inhibiting AMPK activation. Though, SIM led to a transient increase in AMPK phosphorylation followed by a sudden decline; the effect was independent of PI3K. Strikingly, AMPK phosphorylation was regulated by protein phosphatase 2A (PP2A) activity which was enhanced upon SIM treatment as evidenced by increase in threonine phosphorylation. Moreover, it was observed that addition of AMP analogue and PP2A inhibitor inhibited SIN. Bio-composition of neurites shows that lipids form a major part of neurites and AMPK is known to regulate lipid metabolism majorly through acetyl CoA carboxylase (ACC). AMPK activity is negative regulator of ACC activity and we found that phosphorylation of ACC started to decrease after 6 hrs which becomes more pronounced at 12 hrs. Addition of ACC inhibitor showed that SIN is dependent on ACC activity. Simultaneously, addition of Fatty acid synthase (FAS) inhibitor confirmed that endogenous lipid pathway is important for SIN. We further investigated SREBP-1 pathway activation which controls ACC and FAS at transcriptional level. However, SIM did not affect SREBP-1 processing and transcription of its target genes likes ACC1 and FAS. In conclusion, this study highlights a distinct role of CSC and ACC in SIN which might have implication in process of neuronal differentiation induced by other agents.
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Affiliation(s)
- Varshiesh Raina
- Molecular Sciences Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi, India
| | - Sarika Gupta
- Molecular Sciences Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi, India
- * E-mail: (AS); (SG)
| | - Saurabh Yadav
- Molecular Sciences Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, Delhi, India
| | - Avadhesha Surolia
- Molecular Biophysics Unit, Indian Institute of Science, Bangaluru, Karnataka, India
- * E-mail: (AS); (SG)
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Posada-Duque RA, Velasquez-Carvajal D, Eckert GP, Cardona-Gomez GP. Atorvastatin requires geranylgeranyl transferase-I and Rac1 activation to exert neuronal protection and induce plasticity. Neurochem Int 2013; 62:433-45. [PMID: 23411415 DOI: 10.1016/j.neuint.2013.01.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 01/23/2013] [Accepted: 01/26/2013] [Indexed: 11/24/2022]
Abstract
Statins are widely used cholesterol-lowering drugs that may reduce the incidence of stroke and the progression of Alzheimer's disease (AD). However, how statins exert these beneficial effects remains poorly understood. Thus, this study evaluated the roles of Rac1 geranylgeranylation and the relationship between Rac1 and αN-catenin in the protective activity of atorvastatin (ATV) in a cortical neuronal culture model of glutamate (GLU) excitotoxicity. We found that ATV-induced neuroprotection and plasticity were blocked by isoprenoids, such as farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP), inhibition of farnesylation (FTI-277) and geranylgeranylation (GGTI-286), down-regulation of GGTase-Iβ and Rac activity and promotion of active RhoA. Additionally, ATV rescued the distribution of dendritic αN-catenin and increased the number and length of dendritic branches; these effects were reversed by GGTI-286, GGTase-Iβ shRNA, Rac1 shRNA and a dominant-negative version of Rac1 (T17N). In summary, our findings suggest that ATV requires GGTase-Iβ, prenylation and active Rac1 to induce protection and plasticity. In this regard, αN-catenin is a marker for stable interactions between adhesion proteins and the actin cytoskeleton and is necessary for the neuroprotective action of ATV.
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Affiliation(s)
- Rafael Andrés Posada-Duque
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, SIU, University of Antioquia, Medellín, Colombia
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