1
|
Ehtezazi T, Rahman K, Davies R, Leach AG. The Pathological Effects of Circulating Hydrophobic Bile Acids in Alzheimer's Disease. J Alzheimers Dis Rep 2023; 7:173-211. [PMID: 36994114 PMCID: PMC10041467 DOI: 10.3233/adr-220071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Recent clinical studies have revealed that the serum levels of toxic hydrophobic bile acids (deoxy cholic acid, lithocholic acid [LCA], and glycoursodeoxycholic acid) are significantly higher in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) when compared to control subjects. The elevated serum bile acids may be the result of hepatic peroxisomal dysfunction. Circulating hydrophobic bile acids are able to disrupt the blood-brain barrier and promote the formation of amyloid-β plaques through enhancing the oxidation of docosahexaenoic acid. Hydrophobic bile acid may find their ways into the neurons via the apical sodium-dependent bile acid transporter. It has been shown that hydrophobic bile acids impose their pathological effects by activating farnesoid X receptor and suppressing bile acid synthesis in the brain, blocking NMDA receptors, lowering brain oxysterol levels, and interfering with 17β-estradiol actions such as LCA by binding to E2 receptors (molecular modelling data exclusive to this paper). Hydrophobic bile acids may interfere with the sonic hedgehog signaling through alteration of cell membrane rafts and reducing brain 24(S)-hydroxycholesterol. This article will 1) analyze the pathological roles of circulating hydrophobic bile acids in the brain, 2) propose therapeutic approaches, and 3) conclude that consideration be given to reducing/monitoring toxic bile acid levels in patients with AD or aMCI, prior/in combination with other treatments.
Collapse
Affiliation(s)
- Touraj Ehtezazi
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Khalid Rahman
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Rhys Davies
- The Walton Centre, NHS Foundation Trust, Liverpool, UK
| | - Andrew G Leach
- School of Pharmacy, University of Manchester, Manchester, UK
| |
Collapse
|
2
|
Huang D, Thompson JA, Chen SC, Adams A, Pitout I, Lima A, Zhang D, Jeffery RCH, Attia MS, McLaren TL, Lamey TM, De Roach JN, McLenachan S, Aung-Htut MT, Fletcher S, Wilton SD, Chen FK. Characterising splicing defects of ABCA4 variants within exons 13-50 in patient-derived fibroblasts. Exp Eye Res 2022; 225:109276. [PMID: 36209838 DOI: 10.1016/j.exer.2022.109276] [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: 05/12/2022] [Revised: 09/12/2022] [Accepted: 09/28/2022] [Indexed: 12/29/2022]
Abstract
The ATP-binding cassette subfamily A member 4 gene (ABCA4)-associated retinopathy, Stargardt disease, is the most common monogenic inherited retinal disease. Given the pathogenicity of numerous ABCA4 variants is yet to be examined and a significant proportion (more than 15%) of ABCA4 variants are categorized as splice variants in silico, we therefore established a fibroblast-based splice assay to analyze ABCA4 variants in an Australian Stargardt disease cohort and characterize the pathogenic mechanisms of ABCA4 variants. A cohort of 67 patients clinically diagnosed with Stargardt disease was recruited. Genomic DNA was analysed using a commercial panel for ABCA4 variant detection and the consequences of ABCA4 variants were predicted in silico. Dermal fibroblasts were propagated from skin biopsies, total RNA was extracted and the ABCA4 transcript was amplified by RT-PCR. Our analysis identified a total of 67 unique alleles carrying 74 unique variants. The most prevalent splice-affecting complex allele c.[5461-10T>C; 5603A>T] was carried by 10% of patients in a compound heterozygous state. ABCA4 transcripts from exon 13 to exon 50 were readily detected in fibroblasts. In this region, aberrant splicing was evident in 10 out of 57 variant transcripts (18%), carried by 19 patients (28%). Patient-derived fibroblasts provide a feasible platform for identification of ABCA4 splice variants located within exons 13-50. Experimental evidence of aberrant splicing contributes to the pathogenic classification for ABCA4 variants. Moreover, identification of variants that affect splicing processes provides opportunities for intervention, in particular antisense oligonucleotide-mediated splice correction.
Collapse
Affiliation(s)
- Di Huang
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Shang-Chih Chen
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Abbie Adams
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia
| | - Ianthe Pitout
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia
| | - Alanis Lima
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia
| | - Dan Zhang
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Rachael C Heath Jeffery
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia; Royal Victorian Eye and Ear Hospital, Centre for Eye Research Australia, East Melbourne, Victoria, Australia
| | - Mary S Attia
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Terri L McLaren
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Tina M Lamey
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - John N De Roach
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Samuel McLenachan
- Ocular Tissue Engineering Laboratory, Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
| | - May Thandar Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Australia; PYC Therapeutics, Harry Perkins Institute of Medical Research, Verdun St, Nedlands, Western Australia, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Australia
| | - Fred K Chen
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Western Australia, Australia; Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia; Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia; Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, Victoria, Australia; Royal Victorian Eye and Ear Hospital, Centre for Eye Research Australia, East Melbourne, Victoria, Australia.
| |
Collapse
|
3
|
Non-Human Primate Blood-Brain Barrier and In Vitro Brain Endothelium: From Transcriptome to the Establishment of a New Model. Pharmaceutics 2020; 12:pharmaceutics12100967. [PMID: 33066641 PMCID: PMC7602447 DOI: 10.3390/pharmaceutics12100967] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/02/2020] [Accepted: 10/09/2020] [Indexed: 12/12/2022] Open
Abstract
The non-human primate (NHP)-brain endothelium constitutes an essential alternative to human in the prediction of molecule trafficking across the blood–brain barrier (BBB). This study presents a comparison between the NHP transcriptome of freshly isolated brain microcapillaries and in vitro-selected brain endothelial cells (BECs), focusing on important BBB features, namely tight junctions, receptors mediating transcytosis (RMT), ABC and SLC transporters, given its relevance as an alternative model for the molecule trafficking prediction across the BBB and identification of new brain-specific transport mechanisms. In vitro BECs conserved most of the BBB key elements for barrier integrity and control of molecular trafficking. The function of RMT via the transferrin receptor (TFRC) was characterized in this NHP-BBB model, where both human transferrin and anti-hTFRC antibody showed increased apical-to-basolateral passage in comparison to control molecules. In parallel, eventual BBB-related regional differences were Investig.igated in seven-day in vitro-selected BECs from five brain structures: brainstem, cerebellum, cortex, hippocampus, and striatum. Our analysis retrieved few differences in the brain endothelium across brain regions, suggesting a rather homogeneous BBB function across the brain parenchyma. The presently established NHP-derived BBB model closely mimics the physiological BBB, thus representing a ready-to-use tool for assessment of the penetration of biotherapeutics into the human CNS.
Collapse
|
4
|
Gliozzi M, Musolino V, Bosco F, Scicchitano M, Scarano F, Nucera S, Zito MC, Ruga S, Carresi C, Macrì R, Guarnieri L, Maiuolo J, Tavernese A, Coppoletta AR, Nicita C, Mollace R, Palma E, Muscoli C, Belzung C, Mollace V. Cholesterol homeostasis: Researching a dialogue between the brain and peripheral tissues. Pharmacol Res 2020; 163:105215. [PMID: 33007421 DOI: 10.1016/j.phrs.2020.105215] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/23/2020] [Accepted: 09/24/2020] [Indexed: 02/07/2023]
Abstract
Cholesterol homeostasis is a highly regulated process in human body because of its several functions underlying the biology of cell membranes, the synthesis of all steroid hormones and bile acids and the need of trafficking lipids destined to cell metabolism. In particular, it has been recognized that peripheral and central nervous system cholesterol metabolism are separated by the blood brain barrier and are regulated independently; indeed, peripherally, it depends on the balance between dietary intake and hepatic synthesis on one hand and its degradation on the other, whereas in central nervous system it is synthetized de novo to ensure brain physiology. In view of this complex metabolism and its relevant functions in mammalian, impaired levels of cholesterol can induce severe cellular dysfunction leading to metabolic, cardiovascular and neurodegenerative diseases. The aim of this review is to clarify the role of cholesterol homeostasis in health and disease highlighting new intriguing aspects of the cross talk between its central and peripheral metabolism.
Collapse
Affiliation(s)
- Micaela Gliozzi
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Vincenzo Musolino
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Francesca Bosco
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Miriam Scicchitano
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Federica Scarano
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Saverio Nucera
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Maria Caterina Zito
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Stefano Ruga
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Cristina Carresi
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Roberta Macrì
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Lorenza Guarnieri
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Jessica Maiuolo
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Annamaria Tavernese
- Division of Cardiology, University Hospital Policlinico Tor Vergata, Rome, Italy.
| | - Anna Rita Coppoletta
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Caterina Nicita
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Rocco Mollace
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Ernesto Palma
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
| | - Carolina Muscoli
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy; IRCCS San Raffaele Pisana, Via di Valcannuta, Rome, Italy.
| | | | - Vincenzo Mollace
- Institute of Research for Food Safety & Health (IRC-FSH) - Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy; IRCCS San Raffaele Pisana, Via di Valcannuta, Rome, Italy.
| |
Collapse
|
5
|
Identification of a combination of transcription factors that synergistically increases endothelial cell barrier resistance. Sci Rep 2020; 10:3886. [PMID: 32127614 PMCID: PMC7054428 DOI: 10.1038/s41598-020-60688-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 02/12/2020] [Indexed: 12/15/2022] Open
Abstract
Endothelial cells (ECs) display remarkable plasticity during development before becoming quiescent and functionally mature. EC maturation is directed by several known transcription factors (TFs), but the specific set of TFs responsible for promoting high-resistance barriers, such as the blood-brain barrier (BBB), have not yet been fully defined. Using expression mRNA data from published studies on ex vivo ECs from the central nervous system (CNS), we predicted TFs that induce high-resistance barrier properties of ECs as in the BBB. We used our previously established method to generate ECs from human pluripotent stem cells (hPSCs), and then we overexpressed the candidate TFs in hPSC-ECs and measured barrier resistance and integrity using electric cell-substrate impedance sensing, trans-endothelial electrical resistance and FITC-dextran permeability assays. SOX18 and TAL1 were the strongest EC barrier-inducing TFs, upregulating Wnt-related signaling and EC junctional gene expression, respectively, and downregulating EC proliferation-related genes. These TFs were combined with SOX7 and ETS1 that together effectively induced EC barrier resistance, decreased paracellular transport and increased protein expression of tight junctions and induce mRNA expression of several genes involved in the formation of EC barrier and transport. Our data shows identification of a transcriptional network that controls barrier resistance in ECs. Collectively this data may lead to novel approaches for generation of in vitro models of the BBB.
Collapse
|
6
|
Tachikawa M, Toki H, Watanabe M, Tomi M, Hosoya KI, Terasaki T. Gene expression of A6-like subgroup of ATP-binding cassette transporters in mouse brain parenchyma and microvessels. Anat Sci Int 2018. [DOI: 10.1007/s12565-018-0435-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
7
|
Sasaki K, Tachikawa M, Uchida Y, Hirano S, Kadowaki F, Watanabe M, Ohtsuki S, Terasaki T. ATP-Binding Cassette Transporter A Subfamily 8 Is a Sinusoidal Efflux Transporter for Cholesterol and Taurocholate in Mouse and Human Liver. Mol Pharm 2018; 15:343-355. [DOI: 10.1021/acs.molpharmaceut.7b00679] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kazunari Sasaki
- Membrane Transport
and Drug Targeting Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Masanori Tachikawa
- Membrane Transport
and Drug Targeting Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Yasuo Uchida
- Membrane Transport
and Drug Targeting Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Satoshi Hirano
- Membrane Transport
and Drug Targeting Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Fumito Kadowaki
- Membrane Transport
and Drug Targeting Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Michitoshi Watanabe
- Membrane Transport
and Drug Targeting Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Sumio Ohtsuki
- Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8555, Japan
| | - Tetsuya Terasaki
- Membrane Transport
and Drug Targeting Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| |
Collapse
|
8
|
Pereira CD, Martins F, Wiltfang J, da Cruz e Silva OA, Rebelo S. ABC Transporters Are Key Players in Alzheimer’s Disease. J Alzheimers Dis 2017; 61:463-485. [DOI: 10.3233/jad-170639] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Cátia D. Pereira
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Filipa Martins
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Jens Wiltfang
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Odete A.B. da Cruz e Silva
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Sandra Rebelo
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| |
Collapse
|
9
|
Expression and function of Abcg4 in the mouse blood-brain barrier: role in restricting the brain entry of amyloid-β peptide. Sci Rep 2017; 7:13393. [PMID: 29042617 PMCID: PMC5645361 DOI: 10.1038/s41598-017-13750-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 09/27/2017] [Indexed: 12/04/2022] Open
Abstract
ABCG4 is an ATP-binding cassette transmembrane protein which has been shown, in vitro, to participate in the cellular efflux of desmosterol and amyloid-β peptide (Aβ). ABCG4 is highly expressed in the brain, but its localization and function at the blood-brain barrier (BBB) level remain unknown. We demonstrate by qRT-PCR and confocal imaging that mouse Abcg4 is expressed in the brain capillary endothelial cells. Modelling studies of the Abcg4 dimer suggested that desmosterol showed thermodynamically favorable binding at the putative sterol-binding site, and this was greater than for cholesterol. Additionally, unbiased docking also showed Aβ binding at this site. Using a novel Abcg4-deficient mouse model, we show that Abcg4 was able to export Aβ and desmosterol at the BBB level and these processes could be inhibited by probucol and L-thyroxine. Our assay also showed that desmosterol antagonized the export of Aβ, presumably as both bind at the sterol-binding site on Abcg4. We show for the first time that Abcg4 may function in vivo to export Aβ at the BBB, in a process that can be antagonized by its putative natural ligand, desmosterol (and possibly cholesterol).
Collapse
|
10
|
Affiliation(s)
- Wheaton T Little
- Takeda Pharmaceuticals, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
| | - Ceri H Davies
- Takeda Pharmaceuticals, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| |
Collapse
|
11
|
Gosselet F, Saint-Pol J, Fenart L. Effects of oxysterols on the blood–brain barrier: Implications for Alzheimer’s disease. Biochem Biophys Res Commun 2014; 446:687-91. [DOI: 10.1016/j.bbrc.2013.11.059] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 11/11/2013] [Indexed: 12/31/2022]
|
12
|
Abuznait AH, Kaddoumi A. Role of ABC transporters in the pathogenesis of Alzheimer's disease. ACS Chem Neurosci 2012. [PMID: 23181169 DOI: 10.1021/cn300077c] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common form of age-related dementia that begins with memory loss and progresses to include severe cognitive impairment. A major pathological hallmark of AD is the accumulation of beta amyloid peptide (Aβ) in senile plaques in the brain of AD patients. The exact mechanism by which AD takes place remains unknown. However, an increasing number of studies suggests that ATP-binding cassette (ABC) transporters, which are localized on the surface of brain endothelial cells of the blood-brain barrier (BBB) and brain parenchyma, may contribute to the pathogenesis of AD. Recent studies have unraveled important roles of ABC transporters including ABCB1 (P-glycoprotein, P-gp), ABCG2 (breast cancer resistant protein, BCRP), ABCC1 (multidrug resistance protein 1, MRP1), and the cholesterol transporter ABCA1 in the pathogenesis of AD and Aβ peptides deposition inside the brain. Therefore, understanding the mechanisms by which these transporters contribute to Aβ deposition in the brain is important for the development of new therapeutic strategies against AD. This review summarizes and highlights the accumulating evidence in the literature which describe the role of altered function of various ABC transporters in the pathogenesis and progression of AD and the implications of modulating their functions for the treatment of AD.
Collapse
Affiliation(s)
- Alaa H. Abuznait
- Department of Basic Pharmaceutical
Sciences, College
of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana 71201, United States
| | - Amal Kaddoumi
- Department of Basic Pharmaceutical
Sciences, College
of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana 71201, United States
| |
Collapse
|
13
|
Piehler AP, Ozcürümez M, Kaminski WE. A-Subclass ATP-Binding Cassette Proteins in Brain Lipid Homeostasis and Neurodegeneration. Front Psychiatry 2012; 3:17. [PMID: 22403555 PMCID: PMC3293240 DOI: 10.3389/fpsyt.2012.00017] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 02/19/2012] [Indexed: 12/24/2022] Open
Abstract
The A-subclass of ATP-binding cassette (ABC) transporters comprises 12 structurally related members of the evolutionarily highly conserved superfamily of ABC transporters. ABCA transporters represent a subgroup of "full-size" multispan transporters of which several members have been shown to mediate the transport of a variety of physiologic lipid compounds across membrane barriers. The importance of ABCA transporters in human disease is documented by the observations that so far four members of this protein family (ABCA1, ABCA3, ABCA4, ABCA12) have been causatively linked to monogenetic disorders including familial high-density lipoprotein deficiency, neonatal surfactant deficiency, degenerative retinopathies, and congenital keratinization disorders. Recent research also point to a significant contribution of several A-subfamily ABC transporters to neurodegenerative diseases, in particular Alzheimer's disease (AD). This review will give a summary of our current knowledge of the A-subclass of ABC transporters with a special focus on brain lipid homeostasis and their involvement in AD.
Collapse
|
14
|
Wolf A, Bauer B, Hartz AMS. ABC Transporters and the Alzheimer's Disease Enigma. Front Psychiatry 2012; 3:54. [PMID: 22675311 PMCID: PMC3366330 DOI: 10.3389/fpsyt.2012.00054] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 05/15/2012] [Indexed: 11/25/2022] Open
Abstract
Alzheimer's disease (AD) is considered the "disease of the twenty-first century." With a 10-fold increase in global incidence over the past 100 years, AD is now reaching epidemic proportions and by all projections, AD patient numbers will continue to rise. Despite intense research efforts, AD remains a mystery and effective therapies are still unavailable. This represents an unmet need resulting in clinical, social, and economic problems. Over the last decade, a new AD research focus has emerged: ATP-binding cassette (ABC) transporters. In this article, we provide an overview of the ABC transporters ABCA1, ABCA2, P-glycoprotein (ABCB1), MRP1 (ABCC1), and BCRP (ABCG2), all of which are expressed in the brain and have been implicated in AD. We summarize recent findings on the role of these five transporters in AD, and discuss their potential to serve as therapeutic targets.
Collapse
Affiliation(s)
- Andrea Wolf
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Minnesota Duluth, MN, USA
| | | | | |
Collapse
|
15
|
Do TM, Ouellet M, Calon F, Chimini G, Chacun H, Farinotti R, Bourasset F. Direct evidence of abca1-mediated efflux of cholesterol at the mouse blood-brain barrier. Mol Cell Biochem 2011; 357:397-404. [PMID: 21660464 DOI: 10.1007/s11010-011-0910-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 05/28/2011] [Indexed: 02/07/2023]
Abstract
We investigated the expression and function of Abca1 in wild-type C57BL/6, abca1(+/+), and abca1(-/-) mice brain capillaries forming the blood-brain barrier (BBB). We first demonstrated by quantitative RT-PCR and Western immunoblot that Abca1 was expressed and enriched in the wild-type mouse brain capillaries. In abca1(-/-) mice, we reported that the lack of Abca1 resulted in an 1.6-fold increase of the Abcg4 expression level compared to abca1(+/+) mice. Next, using the in situ brain perfusion technique, we showed that the [(3)H]cholesterol brain uptake clearance (Cl(up), μl/s/g brain), was significantly increased (107%) in abca1(-/-) mice compared to abca1(+/+) mice, meaning that the deficiency of Abca1 conducted to a significant decrease of the cholesterol efflux at the BBB level. In addition, the co-perfusion of probucol (Abca1 inhibitor) with [(3)H]cholesterol resulted in an increase of [(3)H]cholesterol Cl(up) (115%) in abca1(+/+) but not in abca1(-/-) mice, meaning that probucol inhibited selectively the efflux function of Abca1. In conclusion, our results demonstrated that Abca1 was expressed in the mouse brain capillaries and that Abca1 functions as an efflux transporter through the mouse BBB.
Collapse
Affiliation(s)
- Tuan Minh Do
- Laboratory of Clinical Pharmacy, EA4123, University of Paris Sud 11, 5 rue Jean-Baptiste Clément, 92296 Châtenay-Malabry, France
| | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
The blood-brain barrier (BBB) is a dynamic physical and biological barrier between blood circulation and the central nervous system (CNS). This unique feature of the BBB lies in the structure of the neurovascular unit and its cerebral micro-vascular endothelial cells. The BBB restricts the passage of blood-borne drugs, neurotoxic substances and peripheral immune cells from entering the brain, while selectively facilitating the transport of nutrients across the BBB into the brain. Thus, the integrity and proper function of the BBB is crucial to homeostasis and physiological function of the CNS. A number of transport and carrier systems are expressed and polarized on the luminal or abluminal surface of the BBB to realize these discrete functions. Among these systems, ABC transporters play a critical role in keeping drugs and neurotoxic substances from entering the brain and in transporting toxic metabolites out of the brain. A number of studies have demonstrated that ABCB1 and ABCG2 are critical to drug efflux at the BBB and that ABCC1 is essential for the blood-cerebral spinal fluid (CSF) barrier. The presence of these efflux ABC transporters also creates a major obstacle for drug delivery into the brain. We have comprehensively reviewed the literature on ABC transporters and drug efflux at the BBB. Understanding the molecular mechanisms of these transporters is important in the development of new drugs and new strategies for drug delivery into the brain.
Collapse
Affiliation(s)
- Shanshan Shen
- Neurobiology Program, Institute for Biological Sciences, National Research Council of Canada, Ottawa, Canada K1A 0R6
| | | |
Collapse
|
17
|
The expression of LDL receptor in vessels with blood–brain barrier impairment in a stroke-prone hypertensive model. Histochem Cell Biol 2010; 133:669-76. [DOI: 10.1007/s00418-010-0705-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2010] [Indexed: 01/30/2023]
|
18
|
Transcriptional profiles of receptors and transporters involved in brain cholesterol homeostasis at the blood-brain barrier: use of an in vitro model. Brain Res 2008; 1249:34-42. [PMID: 18996096 DOI: 10.1016/j.brainres.2008.10.036] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 09/04/2008] [Accepted: 10/11/2008] [Indexed: 01/03/2023]
Abstract
Brain is the most cholesterol rich organ of the whole body and recent studies suggest a role for the blood-brain barrier (BBB) in cerebral cholesterol homeostasis. Low density lipoprotein receptor (LDLR)-related receptors and ATP-binding Cassette (ABC) transporters play an important role in peripheral sterol homeostasis. The purpose of this study was to determine the mRNA expression profiles of ABC transporters (ABCA1, 2, 3, 7 and ABCG1) and low density lipoprotein receptor (LDLR)-related receptors (LDLR, vLDLR, LRP1, LRP2 and LRP8) in BBB endothelium using an in vitro co-culture model of bovine brain capillary endothelial cells (BCECs) and rat glial cells. All transcripts tested are expressed by BCECs and in capillary extract, except vLDLR. Glial cells influence ABCG1, A1, 2, 7 and LRP1 transcription, suggesting a role in cerebral lipid supply/elimination through the modulation of the expression of these transporters and receptors by these cells. Altogether, these results highlight the importance of glial input in the BBB transport phenotype for sterol homeostasis in the central nervous system, and confirm the importance of the BBB in this process.
Collapse
|
19
|
Cattelotte J, André P, Ouellet M, Bourasset F, Scherrmann JM, Cisternino S. In situ mouse carotid perfusion model: glucose and cholesterol transport in the eye and brain. J Cereb Blood Flow Metab 2008; 28:1449-59. [PMID: 18446168 DOI: 10.1038/jcbfm.2008.34] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The in situ mouse brain perfusion method for measuring blood-brain barrier permeability was adapted to assess transport of solutes at the blood-brain and blood-eye barriers. The procedure was checked with radiolabeled markers in oxygenated bicarbonate-buffered fluid infused for 30 to 120 sec via a carotid artery. Vascular flow estimated with diazepam was 2.2-fold lower in the eye than in the brain. The vascular volume and the integrity markers sucrose and inulin indicated that a perfusion flow rate of 2.5 mL/min preserved the physical integrity of these organs. However, the brain vasculature integrity was more sensitive to acute perfusion pressure than the eye vasculature. The functional capacities of blood barriers were assessed with D-glucose; its transport followed Michaelis-Menten kinetics with an apparent K(m) of 7.6 mmol/L and a V(max) of 23 micromol/sec per g in the brain, and a K(m) of 22.9 mmol/L and a V(max) of 40 micromol/sec per g in the eye. The transport of cholesterol to the brain and eye was significantly enhanced by adding the Abca1 inhibitor probucol, suggesting an Abca1-mediated efflux at the mouse brain and eye blood barriers. Thus in situ carotid perfusion is suitable for elucidating transport processes at the blood-brain and blood-eye barriers.
Collapse
Affiliation(s)
- Julie Cattelotte
- Department of Pharmacokinetics, Faculty of Pharmacy, INSERM U705, CNRS UMR 7157, Université Paris Descartes, Paris, France
| | | | | | | | | | | |
Collapse
|
20
|
Kim WS, Weickert CS, Garner B. Role of ATP-binding cassette transporters in brain lipid transport and neurological disease. J Neurochem 2008; 104:1145-66. [DOI: 10.1111/j.1471-4159.2007.05099.x] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
21
|
Quezada CA, Garrido WX, González-Oyarzún MA, Rauch MC, Salas MR, Martín RES, Claude AA, Yañez AJ, Slebe JC, Cárcamo JG. Effect of Tacrolimus on Activity and Expression of P-Glycoprotein and ATP-Binding Cassette Transporter A5 (ABCA5) Proteins in Hematoencephalic Barrier Cells. Biol Pharm Bull 2008; 31:1911-6. [DOI: 10.1248/bpb.31.1911] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Claudia Andrea Quezada
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | - Wallys Ximena Garrido
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | | | - María Cecilia Rauch
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | - Mónica Roxana Salas
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | - Rody Enrique San Martín
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | - Alejandro Andrés Claude
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | - Alejandro Javier Yañez
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | - Juan Carlos Slebe
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| | - Juan Guillermo Cárcamo
- Laboratorio de Bioquímica y Farmacología Tumoral, Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile
| |
Collapse
|
22
|
ATP-binding cassette transporter A1 (ABCA1) deficiency does not attenuate the brain-to-blood efflux transport of human amyloid-beta peptide (1-40) at the blood-brain barrier. Neurochem Int 2007; 52:956-61. [PMID: 18201804 DOI: 10.1016/j.neuint.2007.12.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Revised: 11/30/2007] [Accepted: 12/04/2007] [Indexed: 11/22/2022]
Abstract
ATP-binding cassette transporter A1 (ABCA1) mediates apolipoprotein-dependent cholesterol release from cellular membranes. Recent studies using ABCA1 knockout mice have demonstrated that ABCA1 affects amyloid-beta peptide (A beta) levels in the brain and the production of senile plaque. Cerebral A beta(1-40) was eliminated from the brain to the circulating blood via the blood-brain barrier (BBB), which expresses ABCA1. Therefore, in the present study, we examined whether ABCA1 affects the brain-to-blood efflux transport of human A beta(1-40)(hA beta(1-40)) at the BBB. The apparent uptake of [125I]hA beta(1-40) into ABCA1-expressing HEK293 cells was not significantly different from that into parental HEK293 cells. In addition, the apparent uptake was not significantly affected even in the presence of apolipoprotein A-I as a cholesterol release acceptor. Moreover, [125I]hA beta(1-40) elimination from mouse brain across the BBB was not significantly different between ABCA1-deficient and wild-type mice 60 min after its administration into the cerebrum. These results suggest that ABCA1 does not directly transport hA beta(1-40) and a deficiency of ABCA1 does not attenuate the brain-to-blood efflux transport of hA beta(1-40) across the BBB.
Collapse
|
23
|
Akanuma SI, Hori S, Ohtsuki S, Fujiyoshi M, Terasaki T. Expression of nuclear receptor mRNA and liver X receptor-mediated regulation of ABC transporter A1 at rat blood-brain barrier. Neurochem Int 2007; 52:669-74. [PMID: 17919779 DOI: 10.1016/j.neuint.2007.08.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 08/03/2007] [Accepted: 08/22/2007] [Indexed: 10/22/2022]
Abstract
The aim of the present study was to investigate the expression of nuclear receptor mRNA and regulation of the expression of ATP-binding cassette (ABC) transporters by nuclear receptor agonists in rat brain capillary endothelial cells, which form the blood-brain barrier, by using rat brain capillary fraction from 8-week-old rats and a conditionally immortalized brain capillary endothelial cell line (TR-BBB13). RT-PCR analysis revealed that liver X receptor alpha and beta, retinoid X receptor alpha and beta and peroxisome proliferator-activating receptor alpha and beta mRNAs were expressed in the rat brain capillary endothelial cells and TR-BBB cells. In contrast, pregnane X receptor, farnesoid X receptor and constitutive androstane receptor were not detected. Furthermore, treatment with a liver X receptor agonist increased the ABCA1 mRNA level in TR-BBB13 cells, while ABCG2 mRNA expression was not affected. Treatment with a rat pregnane X receptor agonist did not affect the ABCB1 mRNA level in TR-BBB13 cells. These results demonstrate that the rat blood-brain barrier has an expressional regulation mechanism via sterol-related nuclear receptor, and indicate that the blood-brain barrier in 8-week-old rats lacks ABCB1 regulation via pregnane X receptor.
Collapse
Affiliation(s)
- Shin-ichi Akanuma
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | | | | | | | | |
Collapse
|
24
|
Tachikawa M, Toki H, Tomi M, Hosoya KI. Gene expression profiles of ATP-binding cassette transporter A and C subfamilies in mouse retinal vascular endothelial cells. Microvasc Res 2007; 75:68-72. [PMID: 17574281 DOI: 10.1016/j.mvr.2007.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 05/10/2007] [Indexed: 11/15/2022]
Abstract
The purpose of this study was to quantify gene expression levels of the ATP-binding cassette (ABC) transporter A and C subfamilies ABCA1-A9, and ABCC1-6/Mrp1-6, C10/Mrp7 in mouse retinal vascular endothelial cells (RVEC) using a combination of a magnetic isolation method for mouse RVEC and real-time quantitative PCR analysis. The transcript level of endothelial cell markers, such as CD31, Tie-2, claudin-5, occludin, ABCB1a/mdr1a, and ABCG2, were more than 20-fold higher than those in the non-RVEC fraction, suggesting that RVEC in the RVEC fraction are concentrated at least 20-fold compared with those of the non-RVEC fraction. In the ABCA1 to A9 families, the transcript level of ABCA3 and A9 in the RVEC fraction was 1.2- and 32-fold higher than that in the non-RVEC fraction. Although ABCA3 was expressed in both the RVEC and non-RVEC fractions, A9 is predominantly expressed in the RVEC fraction. In the ABCC1 to C6 and C10 families, the transcript level of ABCC3, C4, and C6 in the RVEC fraction was 27-, 251-, and 242-fold higher, respectively, than that in the non-RVEC fraction, suggesting that ABCC3, C4, and C6 are predominantly expressed in the RVEC. In conclusion, ABCA3, ABCA9, ABCC3, ABCC4, and ABCC6 mRNAs are predominantly expressed at the inner blood-retina barrier (inner BRB) and appear to play a major role in the efflux transport of their substrates at the inner BRB.
Collapse
Affiliation(s)
- Masanori Tachikawa
- Department of Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | | | | | | |
Collapse
|
25
|
Carter CJ. Convergence of genes implicated in Alzheimer's disease on the cerebral cholesterol shuttle: APP, cholesterol, lipoproteins, and atherosclerosis. Neurochem Int 2006; 50:12-38. [PMID: 16973241 DOI: 10.1016/j.neuint.2006.07.007] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 06/30/2006] [Accepted: 07/11/2006] [Indexed: 11/24/2022]
Abstract
Polymorphic genes associated with Alzheimer's disease (see ) delineate a clearly defined pathway related to cerebral and peripheral cholesterol and lipoprotein homoeostasis. They include all of the key components of a glia/neurone cholesterol shuttle including cholesterol binding lipoproteins APOA1, APOA4, APOC1, APOC2, APOC3, APOD, APOE and LPA, cholesterol transporters ABCA1, ABCA2, lipoprotein receptors LDLR, LRP1, LRP8 and VLDLR, and the cholesterol metabolising enzymes CYP46A1 and CH25H, whose oxysterol products activate the liver X receptor NR1H2 and are metabolised to esters by SOAT1. LIPA metabolises cholesterol esters, which are transported by the cholesteryl ester transport protein CETP. The transcription factor SREBF1 controls the expression of most enzymes of cholesterol synthesis. APP is involved in this shuttle as it metabolises cholesterol to 7-betahydroxycholesterol, a substrate of SOAT1 and HSD11B1, binds to APOE and is tethered to LRP1 via APPB1, APBB2 and APBB3 at the cytoplasmic domain and via LRPAP1 at the extracellular domain. APP cleavage products are also able to prevent cholesterol binding to APOE. BACE cleaves both APP and LRP1. Gamma-secretase (PSEN1, PSEN2, NCSTN) cleaves LRP1 and LRP8 as well as APP and their degradation products control transcription factor TFCP2, which regulates thymidylate synthase (TS) and GSK3B expression. GSK3B is known to phosphorylate the microtubule protein tau (MAPT). Dysfunction of this cascade, carved out by genes implicated in Alzheimer's disease, may play a major role in its pathology. Many other genes associated with Alzheimer's disease affect cholesterol or lipoprotein function and/or have also been implicated in atherosclerosis, a feature of Alzheimer's disease, and this duality may well explain the close links between vascular and cerebral pathology in Alzheimer's disease. The definition of many of these genes as risk factors is highly contested. However, when polymorphic susceptibility genes belong to the same signaling pathway, the risk associated with multigenic disease is better related to the integrated effects of multiple polymorphisms of genes within the same pathway than to variants in any single gene [Wu, X., Gu, J., Grossman, H.B., Amos, C.I., Etzel, C., Huang, M., Zhang, Q., Millikan, R.E., Lerner, S., Dinney, C.P., Spitz, M.R., 2006. Bladder cancer predisposition: a multigenic approach to DNA-repair and cell-cycle-control genes. Am. J. Hum. Genet. 78, 464-479.]. Thus, the fact that Alzheimer's disease susceptibility genes converge on a clearly defined signaling network has important implications for genetic association studies.
Collapse
|
26
|
Kim WS, Guillemin GJ, Glaros EN, Lim CK, Garner B. Quantitation of ATP-binding cassette subfamily-A transporter gene expression in primary human brain cells. Neuroreport 2006; 17:891-6. [PMID: 16738483 DOI: 10.1097/01.wnr.0000221833.41340.cd] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Five ATP-binding cassette (ABC) subfamily-A transporters (ABCA1, ABCA2, ABCA3, ABCA7 and ABCA8) are expressed in the brain. These transporters may regulate brain lipid transport; however, their relative expression level in isolated human brain cells is unknown. We developed real-time polymerase chain reaction assays to quantify the expression of these genes in human neurons, astrocytes, oligodendrocytes, microglia and cell lines. Neurons expressed predominantly ABCA1 and ABCA3; astrocytes ABCA1, ABCA2 and ABCA3; microglia ABCA1 and oligodendrocytes ABCA2 and ABCA3. Although ABCA7 and ABCA8 expression was relatively low in all cells, the highest expression occurred in microglia and neurons, respectively. ABCA gene expression in the NTERA-2 and MO3.13 cell lines closely resembled the ABCA expression pattern of primary neurons and oligodendrocytes, respectively.
Collapse
Affiliation(s)
- Woojin S Kim
- Prince of Wales Medical Research Institute, Randwick, New South Wales, Australia.
| | | | | | | | | |
Collapse
|
27
|
Liu HC, Hu CJ, Chang JG, Sung SM, Lee LS, Yuan RY, Leu SJ. Proteomic identification of lower apolipoprotein A-I in Alzheimer's disease. Dement Geriatr Cogn Disord 2006; 21:155-61. [PMID: 16391478 DOI: 10.1159/000090676] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/12/2005] [Indexed: 11/19/2022] Open
Abstract
Many researches have been trying to find the potential biomarkers for Alzheimer's disease (AD). We hereby used the proteomics method to search for protein expression differences in the serum between AD patients and controls. We enrolled 59 AD patients and 74 age- and sex-matched controls in this study. Ten AD patients and 10 controls were selected for proteomic analysis. Apolipoprotein A-I (ApoA-I) was found to have a lower expression in the AD group by a proteomics two-dimensional gel electrophoresis study. We further measured the serum ApoA-I level which was significantly lower in the AD patients (112.29 +/- 21.33 mg/dl) in comparison to the controls (144.53 +/- 19.91 mg/dl; p < 0.0002). Lower serum ApoA-I levels might be a potential biomarker for AD.
Collapse
Affiliation(s)
- Hsing-Cheng Liu
- Department of Psychiatry, Taipei City Hospital, Taipei, Taiwan, ROC
| | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
Alzheimer's disease (AD) is the most common form of neurodegenerative dementia and affects up to 15 million people worldwide. Although no single cause of AD has been identified, recent research has suggested that several pathogenetic factors influence risk and expression. A growing amount of evidence underscores a mechanistic link between cholesterol metabolism in the brain and the formation of amyloid plaques. Excess brain cholesterol has been associated with increased formation and deposition of amyloid-beta peptide from amyloid precursor protein. Cholesterol-lowering statins have become a focus of research in AD. Genetic polymorphisms associated with pivotal points in cholesterol metabolism in brain tissues may contribute to the risk and pathogenesis of AD. In this review, we summarise current knowledge of the role of cholesterol metabolism in the pathogenesis of AD and examine the potential of statins in the prevention and treatment of AD.
Collapse
Affiliation(s)
- Leila A Shobab
- Division of Neurology, Department of Medicine, Clinic for Alzheimer Disease and Related Disorders, Vancouver Costal Health, University of British Columbia, Vancouver BC, V6T 2B5, Canada
| | | | | |
Collapse
|
29
|
Bhongsatiern J, Ohtsuki S, Tachikawa M, Hori S, Terasaki T. Retinal-specific ATP-binding cassette transporter (ABCR/ABCA4) is expressed at the choroid plexus in rat brain. J Neurochem 2005; 92:1277-80. [PMID: 15715676 DOI: 10.1111/j.1471-4159.2004.02941.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
ATP-binding cassette (ABC) transporter A4 is a member of the ABC transporter subfamily A which has been reported to be exclusively expressed in the retina. In contrast, a previous report has suggested a possible relationship between ABCA4 and CNS function. The purpose of the present study was to investigate the localization of ABCA4 mRNA and protein in rat brain. In situ hybridization analysis revealed that ABCA4 mRNA was localized in the lateral ventricles. RT-PCR analysis detected ABCA4 mRNA in isolated rat choroid plexus and conditionally immortalized rat choroid plexus epithelial cells (TR-CSFB). Furthermore, ABCA4 protein was also detected in the isolated rat choroid plexus at about 250 kDa by western blot analysis, and its apparent molecular size was reduced by N-glycosidase F treatment. These results suggest that glycosylated ABCA4 protein is expressed in rat choroid plexus epithelial cells. ABCA4 may play a role in the function of the blood-cerebrospinal fluid barrier and affect CSF conditions.
Collapse
Affiliation(s)
- Jiraganya Bhongsatiern
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | | | | | | | | |
Collapse
|
30
|
Teng XW, Davies NM, Fukuda C, Good RL, Fariss MW. Pharmacokinetics and tissue distribution ofd-alpha-tocopheryl succinate formulations following intravenous administration in the rat. Biopharm Drug Dispos 2005; 26:195-203. [PMID: 15900617 DOI: 10.1002/bdd.451] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Unlike d-alpha tocopherol (T), d-alpha tocopheryl succinate (TS) has the unique ability to selectively kill tumor cells while protecting normal tissue from toxic oxidative stress. The pharmacokinetics of TS and the serum and tissue disposition of TS were studied in male Sprague-Dawley rats to delineate formulation dependent disposition between TS administered as the Tris salt (TS-T) (a liposomal formulation) or as the free acid (TS-FA) dissolved in polyethylene glycol (PEG) 400. The pharmacokinetics of TS was studied after single intravenous (i.v.) equimolar doses of 124 mg/kg TS-T and 100 mg/kg of TS-FA. Serial blood samples were collected via a catheter inserted into the right jugular vein and serum samples were analysed for TS and T levels using a reverse phase HPLC method. Terminal tissue samples were also collected at 24 and 48 h. After an acute i.v. dose of TS-T, serum AUC, t(1/2), Cl and V(d) of TS were 2601.0 +/- 351.7 microg h/ml, 9.98 +/- 1.02 h, 0.049 +/- 0. 0073 l/h/kg and 0.7 +/- 0.14 l/kg (mean +/- SD), respectively. The acute i.v. administration of TS-FA (PEG formulation) yielded results similar to those observed for TS-T, with a serum AUC, t(1/2), Cl and V(d) of 2553.3 +/- 166.4 microg h/ml, 9.83 +/- 0.86 h, 0.039 +/- 0.0027 l/h/kg and 0.56 +/- 0.09 l/kg (mean +/- SD), respectively. Distribution into tissues and a low Cl was apparent, with the highest concentrations of TS in the liver and lung, regardless of formulation. As expected, baseline endogenous concentrations of T were present in both groups, with a net increase in T levels, occurring as TS was hydrolysed to T, which slowly peaked in serum between 7-8 h post-dose. Intravenous TS administration, regardless of formulation, also resulted in significant T accumulation in all tissues examined, which was especially abundant in the liver and lung. Likewise, there was a lack of significant effect of formulation on the pharmacokinetics and tissue distribution of TS. The only significant formulation difference was a small but significant increase in serum T and liver T levels in the TS in PEG formulation group. These results indicate that TS may be especially useful for the targeted delivery of T and TS to the lung and liver for anti-oxidant and anti-cancer activity.
Collapse
Affiliation(s)
- Xiao Wei Teng
- Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University Pullman, 99164-6534, USA
| | | | | | | | | |
Collapse
|