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Baisgaard AE, Koldby KM, Kristensen TN, Nyegaard M, Rohde PD. Functionally Validating Evolutionary Conserved Risk Genes for Parkinson's Disease in Drosophila melanogaster. INSECTS 2023; 14:168. [PMID: 36835737 PMCID: PMC9958964 DOI: 10.3390/insects14020168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Parkinson's disease (PD) is a heterogeneous and complex neurodegenerative disorder and large-scale genetic studies have identified >130 genes associated with PD. Although genomic studies have been decisive for our understanding of the genetic contributions underlying PD, these associations remain as statistical associations. Lack of functional validation limits the biological interpretation; however, it is labour extensive, expensive, and time consuming. Therefore, the ideal biological system for functionally validating genetic findings must be simple. The study aim was to assess systematically evolutionary conserved PD-associated genes using Drosophila melanogaster. From a literature review, a total of 136 genes have found to be associated with PD in GWAS studies, of which 11 are strongly evolutionary conserved between Homo sapiens and D. melanogaster. By ubiquitous gene expression knockdown of the PD-genes in D. melanogaster, the flies' escape response was investigated by assessing their negative geotaxis response, a phenotype that has previously been used to investigate PD in D. melanogaster. Gene expression knockdown was successful in 9/11 lines, and phenotypic consequences were observed in 8/9 lines. The results provide evidence that genetically modifying expression levels of PD genes in D. melanogaster caused reduced climbing ability of the flies, potentially supporting their role in dysfunctional locomotion, a hallmark of PD.
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Affiliation(s)
- Amalie Elton Baisgaard
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
- Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark
| | | | | | - Mette Nyegaard
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
- Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark
| | - Palle Duun Rohde
- Department of Health Science and Technology, Aalborg University, 9220 Aalborg, Denmark
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
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2
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Roy P, Tomassoni D, Nittari G, Traini E, Amenta F. Effects of choline containing phospholipids on the neurovascular unit: A review. Front Cell Neurosci 2022; 16:988759. [PMID: 36212684 PMCID: PMC9541750 DOI: 10.3389/fncel.2022.988759] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
The roles of choline and of choline-containing phospholipids (CCPLs) on the maintenance and progress of neurovascular unit (NVU) integrity are analyzed. NVU is composed of neurons, glial and vascular cells ensuring the correct homeostasis of the blood-brain barrier (BBB) and indirectly the function of the central nervous system. The CCPLs phosphatidylcholine (lecithin), cytidine 5′-diphosphocholine (CDP-choline), choline alphoscerate or α-glyceryl-phosphorylcholine (α-GPC) contribute to the modulation of the physiology of the NVU cells. A loss of CCPLs contributes to the development of neurodegenerative diseases such as Alzheimer’s disease, multiple sclerosis, Parkinson’s disease. Our study has characterized the cellular components of the NVU and has reviewed the effect of lecithin, of CDP-choline and α-GPC documented in preclinical studies and in limited clinical trials on these compounds. The interesting results obtained with some CCPLs, in particular with α-GPC, probably would justify reconsideration of the most promising molecules in larger attentively controlled studies. This can also contribute to better define the role of the NVU in the pathophysiology of brain disorders characterized by vascular impairment.
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Affiliation(s)
- Proshanta Roy
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Daniele Tomassoni
- School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Giulio Nittari
- School of Medicinal and Health Products Sciences, University of Camerino, Camerino, Italy
| | - Enea Traini
- School of Medicinal and Health Products Sciences, University of Camerino, Camerino, Italy
| | - Francesco Amenta
- School of Medicinal and Health Products Sciences, University of Camerino, Camerino, Italy
- *Correspondence: Francesco Amenta,
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3
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Rawat V, Tyagi R, Singh I, Das P, Srivastava AK, Makharia GK, Sharma U. Cerebellar Abnormalities on Proton MR Spectroscopy and Imaging in Patients With Gluten Ataxia: A Pilot Study. Front Hum Neurosci 2022; 16:782579. [PMID: 35655925 PMCID: PMC9152097 DOI: 10.3389/fnhum.2022.782579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Abstract
Gluten ataxia is a rare immune-mediated neurological disorder caused by the ingestion of gluten. The diagnosis is not straightforward as antibodies are present in only up to 38% of patients, but often at lower titers. The symptoms of ataxia may be mild at the onset but lead to permanent damage if remain untreated. It is characterized by damage to the cerebellum however, the pathophysiology of the disease is not clearly understood. The present study investigated the neurochemical profile of vermis and right cerebellum and structural changes in various brain regions of patients with gluten ataxia (n = 6, age range 40–65 years) and compared it with healthy controls (n = 10, 40–55 years). Volumetric 3-D T1 and T1-weighted magnetic resonance imaging (MRI) in the three planes (axial, coronal, and sagittal) of the whole brain and single-voxel 1H- magnetic resonance spectroscopy (MRS) of the vermis and right cerebellum were acquired on 3 T human MR scanner. The metabolite concentrations were estimated using LC Model (6.1–4A) while brain volumes were estimated using the online tool volBrain pipeline and CERES and corrected for partial volumes. The levels of neuro-metabolites (N-acetyl aspartate + N-acetyl aspartate glutamate, glycerophosphocholine + phosphocholine, and total creatine) were found to be significantly lower in vermis, while N-acetyl aspartate + N-acetyl aspartate glutamate and glycerophosphocholine + phosphocholine was lower in cerebellum regions in the patients with gluten ataxia compared to healthy controls. A significant reduction in the white matter of (total brain, cerebellum, and cerebrum); reduction in the volumes of cerebellum lobe (X) and thalamus while lateral ventricles were increased in the patients with gluten ataxia compared to healthy controls. The reduced neuronal metabolites along with structural changes in the brain suggested neuronal degeneration in the patients with gluten ataxia. Our preliminary findings may be useful in understanding the gluten-induced cerebral damage and indicated that MRI and MRS may serve as a non-invasive useful tool in the early diagnosis, thereby enabling better management of these patients.
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Affiliation(s)
- Vishwa Rawat
- Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India
| | - Ritu Tyagi
- Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India
| | - Inder Singh
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Prasenjit Das
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | | | - Govind K. Makharia
- Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India
| | - Uma Sharma
- Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India
- *Correspondence: Uma Sharma
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Hu M, Zhao H, Yang B, Yang S, Liu H, Tian H, Shui G, Chen Z, E L, Lai J, Song W. ZmCTLP1 is required for the maintenance of lipid homeostasis and the basal endosperm transfer layer in maize kernels. THE NEW PHYTOLOGIST 2021; 232:2384-2399. [PMID: 34559890 PMCID: PMC9292782 DOI: 10.1111/nph.17754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/15/2021] [Indexed: 05/26/2023]
Abstract
Maize kernel weight is influenced by the unloading of nutrients from the maternal placenta and their passage through the transfer tissue of the basal endosperm transfer layer (BETL) and the basal intermediate zone (BIZ) to the upper part of the endosperm. Here, we show that Small kernel 10 (Smk10) encodes a choline transporter-like protein 1 (ZmCTLP1) that facilitates choline uptake and is located in the trans-Golgi network (TGN). Its loss of function results in reduced choline content, leading to smaller kernels with a lower starch content. Mutation of ZmCTLP1 disrupts membrane lipid homeostasis and the normal development of wall in-growths. Expression levels of Mn1 and ZmSWEET4c, two kernel filling-related genes, are downregulated in the smk10, which is likely to be one of the major causes of incompletely differentiated transfer cells. Mutation of ZmCTLP1 also reduces the number of plasmodesmata (PD) in transfer cells, indicating that the smk10 mutant is impaired in PD formation. Intriguingly, we also observed premature cell death in the BETL and BIZ of the smk10 mutant. Together, our results suggest that ZmCTLP1-mediated choline transport affects kernel development, highlighting its important role in lipid homeostasis, wall in-growth formation and PD development in transfer cells.
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Affiliation(s)
- Mingjian Hu
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
| | - Haiming Zhao
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
| | - Bo Yang
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
| | - Shuang Yang
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
| | - Haihong Liu
- State Key Laboratory of Plant Physiology and BiochemistryCollege of Biological SciencesChina Agricultural UniversityBeijing100193China
| | - He Tian
- State Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing100101China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental BiologyInstitute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing100101China
| | - Zongliang Chen
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
- Waksman Institute of MicrobiologyRutgers UniversityPiscatawayNJ08854‐8020USA
| | - Lizhu E
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
- Center for Crop Functional Genomics and Molecular BreedingChina Agricultural UniversityBeijing100193China
| | - Jinsheng Lai
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
- Center for Crop Functional Genomics and Molecular BreedingChina Agricultural UniversityBeijing100193China
| | - Weibin Song
- State Key Laboratory of Plant Physiology and Biochemistry and National Maize Improvement CenterDepartment of Plant Genetics and BreedingChina Agricultural UniversityBeijing100193China
- Center for Crop Functional Genomics and Molecular BreedingChina Agricultural UniversityBeijing100193China
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Fatima A, Ahmad MW, Al Saidi AKA, Choudhury A, Chang Y, Lee GH. Recent Advances in Gadolinium Based Contrast Agents for Bioimaging Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2449. [PMID: 34578765 PMCID: PMC8465722 DOI: 10.3390/nano11092449] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/15/2021] [Accepted: 09/17/2021] [Indexed: 12/12/2022]
Abstract
Gadolinium (Gd) based contrast agents (CAs) (Gd-CAs) represent one of the most advanced developments in the application of Gd for magnetic resonance imaging (MRI). Current challenges with existing CAs generated an urgent requirement to develop multimodal CAs with good biocompatibility, low toxicity, and prolonged circulation time. This review discussed the Gd-CAs used in bioimaging applications, addressing their advantages and limitations. Future research is required to establish the safety, efficacy and theragnostic capabilities of Gd-CAs. Nevertheless, these Gd-CAs offer extraordinary potential as imaging CAs and promise to benefit bioimaging applications significantly.
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Affiliation(s)
- Atiya Fatima
- Department of Chemical Engineering, College of Engineering, Dhofar University, P.O. Box 2509, Salalah 211, Sultanate of Oman;
| | - Md. Wasi Ahmad
- Department of Chemical Engineering, College of Engineering, Dhofar University, P.O. Box 2509, Salalah 211, Sultanate of Oman;
| | - Abdullah Khamis Ali Al Saidi
- Department of Chemistry, College of Natural Sciences, Kyungpook National University (KNU), Taegu 702-701, Korea;
| | - Arup Choudhury
- Department of Chemical Engineering, Birla Institute of Technology, Ranchi 835215, India
| | - Yongmin Chang
- Department of Molecular Medicine and Medical & Biological Engineering, School of Medicine, Kyungpook National University (KNU), Taegu 702-701, Korea;
| | - Gang Ho Lee
- Department of Chemistry, College of Natural Sciences, Kyungpook National University (KNU), Taegu 702-701, Korea;
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Zhao L, Zhu J, Gong J, Song N, Wu S, Qiao W, Yang J, Zhu M, Zhao J. Polyethylenimine-based theranostic nanoplatform for glioma-targeting single-photon emission computed tomography imaging and anticancer drug delivery. J Nanobiotechnology 2020; 18:143. [PMID: 33054757 PMCID: PMC7557081 DOI: 10.1186/s12951-020-00705-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/07/2020] [Indexed: 12/22/2022] Open
Abstract
Background Glioma is the deadliest brain cancer in adults because the blood–brain-barrier (BBB) prevents the vast majority of therapeutic drugs from entering into the central nervous system. The development of BBB-penetrating drug delivery systems for glioma therapy still remains a great challenge. In this study, we aimed to design and develop a theranostic nanocomplex with enhanced BBB penetrability and tumor-targeting efficiency for glioma single-photon emission computed tomography (SPECT) imaging and anticancer drug delivery. Results This multifunctional nanocomplex was manufactured using branched polyethylenimine (PEI) as a template to sequentially conjugate with methoxypolyethylene glycol (mPEG), glioma-targeting peptide chlorotoxin (CTX), and diethylenetriaminepentaacetic acid (DTPA) for 99mTc radiolabeling on the surface of PEI. After the acetylation of the remaining PEI surface amines using acetic anhydride (Ac2O), the CTX-modified PEI (mPEI-CTX) was utilized as a carrier to load chemotherapeutic drug doxorubicin (DOX) in its interior cavity. The formed mPEI-CTX/DOX complex had excellent water dispersibility and released DOX in a sustainable and pH-dependent manner; furthermore, it showed targeting specificity and therapeutic effect of DOX toward glioma cells in vitro and in vivo (a subcutaneous tumor mouse model). Owing to the unique biological properties of CTX, the mPEI-CTX/DOX complex was able to cross the BBB and accumulate at the tumor site in an orthotopic rat glioma model. In addition, after efficient radiolabeling of PEI with 99mTc via DTPA, the 99mTc-labeled complex could help to visualize the drug accumulation in tumors of glioma-bearing mice and the drug delivery into the brains of rats through SPECT imaging. Conclusions These results indicate the potential of the developed PEI-based nanocomplex in facilitating glioma-targeting SPECT imaging and chemotherapy. ![]()
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Affiliation(s)
- Lingzhou Zhao
- Department of Nuclear Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, People's Republic of China
| | - Jingyi Zhu
- School of Pharmaceutical Sciences, Nanjing Tech University, Nanjing, 211816, People's Republic of China
| | - Jiali Gong
- Department of Nuclear Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, People's Republic of China
| | - Ningning Song
- Department of Nuclear Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, People's Republic of China
| | - Shan Wu
- Department of Nuclear Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, People's Republic of China
| | - Wenli Qiao
- Department of Nuclear Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, People's Republic of China
| | - Jiqin Yang
- Department of Nuclear Medicine, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, People's Republic of China.
| | - Meilin Zhu
- School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, 750004, Ningxia, People's Republic of China.
| | - Jinhua Zhao
- Department of Nuclear Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, People's Republic of China.
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7
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Fagerberg CR, Taylor A, Distelmaier F, Schrøder HD, Kibæk M, Wieczorek D, Tarnopolsky M, Brady L, Larsen MJ, Jamra RA, Seibt A, Hejbøl EK, Gade E, Markovic L, Klee D, Nagy P, Rouse N, Agarwal P, Dolinsky VW, Bakovic M. Choline transporter-like 1 deficiency causes a new type of childhood-onset neurodegeneration. Brain 2020; 143:94-111. [PMID: 31855247 DOI: 10.1093/brain/awz376] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 09/11/2019] [Accepted: 10/07/2019] [Indexed: 12/14/2022] Open
Abstract
Cerebral choline metabolism is crucial for normal brain function, and its homoeostasis depends on carrier-mediated transport. Here, we report on four individuals from three families with neurodegenerative disease and homozygous frameshift mutations (Asp517Metfs*19, Ser126Metfs*8, and Lys90Metfs*18) in the SLC44A1 gene encoding choline transporter-like protein 1. Clinical features included progressive ataxia, tremor, cognitive decline, dysphagia, optic atrophy, dysarthria, as well as urinary and bowel incontinence. Brain MRI demonstrated cerebellar atrophy and leukoencephalopathy. Moreover, low signal intensity in globus pallidus with hyperintensive streaking and low signal intensity in substantia nigra were seen in two individuals. The Asp517Metfs*19 and Ser126Metfs*8 fibroblasts were structurally and functionally indistinguishable. The most prominent ultrastructural changes of the mutant fibroblasts were reduced presence of free ribosomes, the appearance of elongated endoplasmic reticulum and strikingly increased number of mitochondria and small vesicles. When chronically treated with choline, those characteristics disappeared and mutant ultrastructure resembled healthy control cells. Functional analysis revealed diminished choline transport yet the membrane phosphatidylcholine content remained unchanged. As part of the mechanism to preserve choline and phosphatidylcholine, choline transporter deficiency was implicated in impaired membrane homeostasis of other phospholipids. Choline treatments could restore the membrane lipids, repair cellular organelles and protect mutant cells from acute iron overload. In conclusion, we describe a novel childhood-onset neurometabolic disease caused by choline transporter deficiency with autosomal recessive inheritance.
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Affiliation(s)
| | - Adrian Taylor
- Department of Human Health and Nutritional Sciences, University of Guelph, Canada
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich-Heine University, Düsseldorf, Germany
| | | | - Maria Kibæk
- Children Hospital of H. C Andersen, Odense University Hospital, Odense, Denmark
| | - Dagmar Wieczorek
- Institute of Human Genetics, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Mark Tarnopolsky
- Department of Pediatrics, Neuromuscular and Neurometabolic Clinic, McMaster University Medical Centre, Hamilton, Canada
| | - Lauren Brady
- Department of Pediatrics, Neuromuscular and Neurometabolic Clinic, McMaster University Medical Centre, Hamilton, Canada
| | - Martin J Larsen
- Department of Clinical Genetics, Odense University Hospital, Odense, Denmark
| | - Rami A Jamra
- Institute of Human Genetics, Leipzig University, Germany and Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Annette Seibt
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich-Heine University, Düsseldorf, Germany
| | | | - Else Gade
- Department of Ophthalmology, Odense University Hospital, 5000 Odense C, Denmark
| | - Ljubo Markovic
- Department of Radiology, Odense University Hospital, 5000 Odense C, Denmark
| | - Dirk Klee
- Department of Diagnostic and Interventional Radiology, Heinrich-Heine University, Düsseldorf, Germany
| | | | | | - Prasoon Agarwal
- Department of Pharmacology and Therapeutics, University of Manitoba, Canada
| | - Vernon W Dolinsky
- Department of Pharmacology and Therapeutics, University of Manitoba, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Canada
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8
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Iwaki H, Blauwendraat C, Leonard HL, Kim JJ, Liu G, Maple-Grødem J, Corvol JC, Pihlstrøm L, van Nimwegen M, Hutten SJ, Nguyen KDH, Rick J, Eberly S, Faghri F, Auinger P, Scott KM, Wijeyekoon R, Van Deerlin VM, Hernandez DG, Gibbs JR, Chitrala KN, Day-Williams AG, Brice A, Alves G, Noyce AJ, Tysnes OB, Evans JR, Breen DP, Estrada K, Wegel CE, Danjou F, Simon DK, Andreassen O, Ravina B, Toft M, Heutink P, Bloem BR, Weintraub D, Barker RA, Williams-Gray CH, van de Warrenburg BP, Van Hilten JJ, Scherzer CR, Singleton AB, Nalls MA. Genomewide association study of Parkinson's disease clinical biomarkers in 12 longitudinal patients' cohorts. Mov Disord 2019; 34:1839-1850. [PMID: 31505070 PMCID: PMC7017876 DOI: 10.1002/mds.27845] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/17/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Several reports have identified different patterns of Parkinson's disease progression in individuals carrying missense variants in GBA or LRRK2 genes. The overall contribution of genetic factors to the severity and progression of Parkinson's disease, however, has not been well studied. OBJECTIVES To test the association between genetic variants and the clinical features of Parkinson's disease on a genomewide scale. METHODS We accumulated individual data from 12 longitudinal cohorts in a total of 4093 patients with 22,307 observations for a median of 3.81 years. Genomewide associations were evaluated for 25 cross-sectional and longitudinal phenotypes. Specific variants of interest, including 90 recently identified disease-risk variants, were also investigated post hoc for candidate associations with these phenotypes. RESULTS Two variants were genomewide significant. Rs382940(T>A), within the intron of SLC44A1, was associated with reaching Hoehn and Yahr stage 3 or higher faster (hazard ratio 2.04 [1.58-2.62]; P value = 3.46E-8). Rs61863020(G>A), an intergenic variant and expression quantitative trait loci for α-2A adrenergic receptor, was associated with a lower prevalence of insomnia at baseline (odds ratio 0.63 [0.52-0.75]; P value = 4.74E-8). In the targeted analysis, we found 9 associations between known Parkinson's risk variants and more severe motor/cognitive symptoms. Also, we replicated previous reports of GBA coding variants (rs2230288: p.E365K; rs75548401: p.T408M) being associated with greater motor and cognitive decline over time, and an APOE E4 tagging variant (rs429358) being associated with greater cognitive deficits in patients. CONCLUSIONS We identified novel genetic factors associated with heterogeneity of Parkinson's disease. The results can be used for validation or hypothesis tests regarding Parkinson's disease. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Hirotaka Iwaki
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
- Data Tecnica International, Glen Echo, Maryland, USA
| | - Cornelis Blauwendraat
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
| | - Hampton L. Leonard
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
- Data Tecnica International, Glen Echo, Maryland, USA
| | - Jonggeol J. Kim
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
| | - Ganqiang Liu
- School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Advanced Center for Parkinson’s Disease Research, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Precision Neurology Program, Harvard Medical School, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Jodi Maple-Grødem
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway
- Department of Chemistry, Bioscience and Environmental Engineering, University in Stavanger, Stavanger, Norway
| | - Jean-Christophe Corvol
- Assistance-Publique Hôpitaux de Paris, ICM, INSERM UMRS 1127, CNRS 7225, ICM, Department of Neurology and CIC Neurosciences, Pitié-Salpêtrière Hospital, Paris, France
| | - Lasse Pihlstrøm
- Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Marlies van Nimwegen
- Radboud University Medical Centre, Donders Institute for Brain, Cognition, and Behaviour; Department of Neurology, Nijmegen, The Netherlands
| | - Samantha J. Hutten
- The Michael J. Fox Foundation for Parkinson’s Research, New York, New York, USA
| | | | - Jacqueline Rick
- Department of Neurology University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Shirley Eberly
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, New York, USA
| | - Faraz Faghri
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
- Department of Computer Science, University of Illinois Urbana-Champaign, Champaign, Illinois, USA
| | - Peggy Auinger
- Department of Neurology, Center for Health + Technology, University of Rochester, Rochester, New York, USA
| | - Kirsten M. Scott
- Department of Clinical Neurosciences, University of Cambridge, John van Geest Centre for Brain Repair, Cambridge, United Kingdom
| | - Ruwani Wijeyekoon
- Department of Clinical Neurosciences, University of Cambridge, John van Geest Centre for Brain Repair, Cambridge, United Kingdom
| | - Vivianna M. Van Deerlin
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, Parelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Dena G. Hernandez
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
| | - J. Raphael Gibbs
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Kumaraswamy Naidu Chitrala
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Aaron G. Day-Williams
- Flagship Labs 60 Inc, Cambridge, Massachusetts, USA
- Statistical Genetics, Biogen, Cambridge, Massachusetts, USA
| | - Alexis Brice
- Institut du cerveau et de la moelle épinière ICM, Paris, France
- Sorbonne Université SU, Paris, France
- INSERM UMR1127, Paris, France
| | - Guido Alves
- The Norwegian Centre for Movement Disorders, Stavanger University Hospital, Stavanger, Norway
- Department of Chemistry, Bioscience and Environmental Engineering, University in Stavanger, Stavanger, Norway
- Department of Neurology, Stavanger University Hospital, Stavanger, Norway
| | - Alastair J. Noyce
- Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, United Kingdom
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, United Kingdom
| | - Ole-Bjørn Tysnes
- Department of Neurology, Haukeland University Hospital, Bergen, Norway
- University of Bergen, Bergen, Norway
| | - Jonathan R. Evans
- Department of Neurology, Nottingham University NHS Trust, Nottingham, United Kingdom
| | - David P. Breen
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland
- Anne Rowling Regenerative Neurology Clinic, University of Edinburgh, Edinburgh, Scotland
- Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, Scotland
| | - Karol Estrada
- Translational Genome Sciences, Biogen, Cambridge, Massachusetts, USA
| | - Claire E. Wegel
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis, Indiana, USA
| | - Fabrice Danjou
- Institut du cerveau et de la moelle épinière ICM, Paris, France
| | - David K. Simon
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Ole Andreassen
- NORMENT, Institute of Clinical Medicine, University of Oslo, Oslo, Norway, Norway
- Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway, Norway
| | - Bernard Ravina
- Voyager Therapeutics, Cambridge, Massachusetts, USA
- Department of Neurology, University of Rochester School of Medicine, Rochester, New York, USA
| | - Mathias Toft
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Peter Heutink
- German Center for Neurodegenerative Diseases-Tubingen, Tuebingen, Germany
- HIH Tuebingen, Tubingen, Tuebingen, Germany
| | - Bastiaan R. Bloem
- Radboud University Medical Centre, Donders Institute for Brain, Cognition, and Behaviour; Department of Neurology, Nijmegen, The Netherlands
| | - Daniel Weintraub
- Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
- Department of Veterans Affairs, Philadelphia, Pennsylvania, USA
| | - Roger A. Barker
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | | | - Bart P. van de Warrenburg
- Radboud University Medical Centre, Donders Institute for Brain, Cognition, and Behaviour; Department of Neurology, Nijmegen, The Netherlands
| | | | - Clemens R. Scherzer
- Advanced Center for Parkinson’s Disease Research, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Precision Neurology Program, Harvard Medical School, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Andrew B. Singleton
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
| | - Mike A. Nalls
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, USA
- Data Tecnica International, Glen Echo, Maryland, USA
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9
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Inazu M. Functional Expression of Choline Transporters in the Blood-Brain Barrier. Nutrients 2019; 11:nu11102265. [PMID: 31547050 PMCID: PMC6835570 DOI: 10.3390/nu11102265] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 12/24/2022] Open
Abstract
Cholinergic neurons in the central nervous system play a vital role in higher brain functions, such as learning and memory. Choline is essential for the synthesis of the neurotransmitter acetylcholine by cholinergic neurons. The synthesis and metabolism of acetylcholine are important mechanisms for regulating neuronal activity. Choline is a positively charged quaternary ammonium compound that requires transporters to pass through the plasma membrane. Currently, there are three groups of choline transporters with different characteristics, such as affinity for choline, tissue distribution, and sodium dependence. They include (I) polyspecific organic cation transporters (OCT1-3: SLC22A1-3) with a low affinity for choline, (II) high-affinity choline transporter 1 (CHT1: SLC5A7), and (III) choline transporter-like proteins (CTL1-5: SLC44A1-5). Brain microvascular endothelial cells, which comprise part of the blood-brain barrier, take up extracellular choline via intermediate-affinity choline transporter-like protein 1 (CTL1) and low-affinity CTL2 transporters. CTL2 is responsible for excreting a high concentration of choline taken up by the brain microvascular endothelial cells on the brain side of the blood-brain barrier. CTL2 is also highly expressed in mitochondria and may be involved in the oxidative pathway of choline metabolism. Therefore, CTL1- and CTL2-mediated choline transport to the brain through the blood-brain barrier plays an essential role in various functions of the central nervous system by acting as the rate-limiting step of cholinergic neuronal activity.
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Affiliation(s)
- Masato Inazu
- Institute of Medical Science, Tokyo Medical University, Tokyo 160-8402, Japan.
- Department of Molecular Preventive Medicine, Tokyo Medical University, Tokyo 160-8402, Japan.
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10
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Mir YR, Kuchay RAH. Advances in identification of genes involved in autosomal recessive intellectual disability: a brief review. J Med Genet 2019; 56:567-573. [PMID: 30842223 DOI: 10.1136/jmedgenet-2018-105821] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 02/01/2019] [Accepted: 02/11/2019] [Indexed: 12/28/2022]
Abstract
Intellectual disability (ID) is a clinically and genetically heterogeneous disorder, affecting 1%-3% of the general population. The number of ID-causing genes is high. Many X-linked genes have been implicated in ID. Autosomal dominant genes have recently been the focus of several large-scale studies. The total number of autosomal recessive ID (ARID) genes is estimated to be very high, and most are still unknown. Although research into the genetic causes of ID has recently gained momentum, identification of pathogenic mutations that cause ARID has lagged behind, predominantly due to non-availability of sizeable families. A commonly used approach to identify genetic loci for recessive disorders in consanguineous families is autozygosity mapping and whole-exome sequencing. Combination of these two approaches has recently led to identification of many genes involved in ID. These genes have diverse function and control various biological processes. In this review, we will present an update regarding genes that have been recently implicated in ID with focus on ARID.
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Affiliation(s)
- Yaser Rafiq Mir
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, Jammu and Kashmir, India
| | - Raja Amir Hassan Kuchay
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, Jammu and Kashmir, India
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11
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Hedtke V, Bakovic M. Choline transport for phospholipid synthesis: An emerging role of choline transporter-like protein 1. Exp Biol Med (Maywood) 2019; 244:655-662. [PMID: 30776907 DOI: 10.1177/1535370219830997] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
IMPACT STATEMENT This review will provide a summary of recent advances in choline transport research and highlight important novel areas of focus in the field.
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Affiliation(s)
- Vera Hedtke
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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12
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Brailoiu E, Chakraborty S, Brailoiu GC, Zhao P, Barr JL, Ilies MA, Unterwald EM, Abood ME, Taylor CW. Choline Is an Intracellular Messenger Linking Extracellular Stimuli to IP 3-Evoked Ca 2+ Signals through Sigma-1 Receptors. Cell Rep 2019; 26:330-337.e4. [PMID: 30625315 PMCID: PMC6326163 DOI: 10.1016/j.celrep.2018.12.051] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/11/2018] [Accepted: 12/11/2018] [Indexed: 11/18/2022] Open
Abstract
Sigma-1 receptors (Sig-1Rs) are integral ER membrane proteins. They bind diverse ligands, including psychoactive drugs, and regulate many signaling proteins, including the inositol 1,4,5-trisphosphate receptors (IP3Rs) that release Ca2+ from the ER. The endogenous ligands of Sig-1Rs are unknown. Phospholipase D (PLD) cleaves phosphatidylcholine to choline and phosphatidic acid (PA), with PA assumed to mediate all downstream signaling. We show that choline is also an intracellular messenger. Choline binds to Sig-1Rs, it mimics other Sig-1R agonists by potentiating Ca2+ signals evoked by IP3Rs, and it is deactivated by metabolism. Receptors, by stimulating PLC and PLD, deliver two signals to IP3Rs: IP3 activates IP3Rs, and choline potentiates their activity through Sig-1Rs. Choline is also produced at synapses by degradation of acetylcholine. Choline uptake by transporters activates Sig-1Rs and potentiates Ca2+ signals. We conclude that choline is an endogenous agonist of Sig-1Rs linking extracellular stimuli, and perhaps synaptic activity, to Ca2+ signals.
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Affiliation(s)
- Eugen Brailoiu
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
| | | | - G Cristina Brailoiu
- Department of Pharmaceutical Sciences, Jefferson College of Pharmacy, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Pingwei Zhao
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Jeffrey L Barr
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Marc A Ilies
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, PA 19140, USA
| | - Ellen M Unterwald
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Mary E Abood
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Colin W Taylor
- Department of Pharmacology, Tennis Court Road, Cambridge CB2 1PD, UK.
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13
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Chen H, Zhou Z, Wang L, Wang H, Liu R, Zhang H, Song L. An invertebrate-specific miRNA targeted the ancient cholinergic neuroendocrine system of oyster. Open Biol 2017; 6:rsob.160059. [PMID: 27488375 PMCID: PMC5008008 DOI: 10.1098/rsob.160059] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 07/05/2016] [Indexed: 02/07/2023] Open
Abstract
Acetylcholine (ACh) is the main neurotransmitter in the cholinergic neuroendocrine system and plays an indispensable role in modulating diverse immune responses. As important transporters in choline uptake, choline transporter-like proteins (CTLs) can control ACh synthesis and release indirectly in multiple organisms. In this study, cgi-miR-2d, an invertebrate-specific miRNA in oyster Crassostrea gigas, is proved to repress the synthesis/release of ACh by targeting CgCTL1 and choline uptake in haemocytes during the early stage of pathogen infection. In short, an opposite expression pattern between CgCTL1 and cgi-miR-2d is observed during Vibrio splendidus infection, accompanied by changes in haemolymph ACh. In addition, the expression level of CgCTL1 is found to be significantly repressed after cgi-miR-2d overexpression in vivo, while both haemocyte choline and haemolymph ACh are also decreased simultaneously, similar to the finding in CgCTL1 knock-down assay. As a result, the expression of two tumour necrosis factor-like proteins and the bacteriostatic activity of oyster haemocytes are found to be altered significantly by either gain-of-function cgi-miR-2d or knock-down of CgCTL1. To our knowledge, this is the first miRNA identified in invertebrates that can target the ancient cholinergic system and augment immune response during infection.
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Affiliation(s)
- Hao Chen
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Zhi Zhou
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China
| | - Lingling Wang
- Key Laboratory of Mariculture and Stock enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, People's Republic of China
| | - Hao Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China
| | - Rui Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China
| | - Huan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China
| | - Linsheng Song
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China Key Laboratory of Mariculture and Stock enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, People's Republic of China
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14
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Zhang L, Liu R, Peng H, Li P, Xu Z, Whittaker AK. The evolution of gadolinium based contrast agents: from single-modality to multi-modality. NANOSCALE 2016; 8:10491-10510. [PMID: 27159645 DOI: 10.1039/c6nr00267f] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Gadolinium-based contrast agents are extensively used as magnetic resonance imaging (MRI) contrast agents due to their outstanding signal enhancement and ease of chemical modification. However, it is increasingly recognized that information obtained from single modal molecular imaging cannot satisfy the higher requirements on the efficiency and accuracy for clinical diagnosis and medical research, due to its limitation and default rooted in single molecular imaging technique itself. To compensate for the deficiencies of single function magnetic resonance imaging contrast agents, the combination of multi-modality imaging has turned to be the research hotpot in recent years. This review presents an overview on the recent developments of the functionalization of gadolinium-based contrast agents, and their application in biomedicine applications.
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Affiliation(s)
- Li Zhang
- Hubei Collaborative Innovation Center for Advance Organic Chemical Materials, Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan, Hubei 430062, China.
| | - Ruiqing Liu
- Hubei Collaborative Innovation Center for Advance Organic Chemical Materials, Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan, Hubei 430062, China.
| | - Hui Peng
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia 4072, Australia.
| | - Penghui Li
- Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zushun Xu
- Hubei Collaborative Innovation Center for Advance Organic Chemical Materials, Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan, Hubei 430062, China.
| | - Andrew K Whittaker
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia 4072, Australia.
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15
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Peng GZ, Ye QF, Wang R, Li MX, Yang ZX. Knockdown by shRNA identifies SLC44A5 as a potential therapeutic target in hepatocellular carcinoma. Mol Med Rep 2016; 13:4845-52. [PMID: 27082540 DOI: 10.3892/mmr.2016.5136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 03/02/2016] [Indexed: 11/06/2022] Open
Abstract
Hepatocellular carcinoma (HCC) has been ranked the second leading cause of cancer‑associated mortality in China and the third leading cause of cancer‑associated mortality worldwide. A number of previous studies investigating SLC44A5 have revealed important biological insight and disease‑specific functions. Therefore, the present study investigated the expression of SLC44A5 in HCC tissues and cell lines, and assessed the effect of SLC44A5 on the viability, cell cycle, apoptosis and invasion of HCC cell lines. The mRNA expression of SLC44A5 in 35 HCC tissues was significantly higher compared with that in 35 normal tissues. The protein expression of SLC44A5 was notably high in MHCC‑97H and SMMC‑7721 cells compared with that in four other HCC cell lines. Knockdown of SLC44A5 using short hairpin RNA inhibited cell viability and arrested the cells in G1 of the cell cycle by reducing the expression of cell cycle markers, proliferating cell nuclear antigen and cyclin‑dependent kinase 2 in MHCC‑97H and SMMC‑7721 cells. Furthermore, SLC44A5 knockdown cells also exhibited cell apoptosis by reducing the expression levels of apoptosis markers, caspase‑3 and caspase‑9 in MHCC‑97H and SMMC‑7721 cells, and suppressed invasion. The present results suggested that SLC44A5 is involved in HCC carcinogenesis and progression in HCC, indicating that SLC44A5 may be a molecular target in cancer therapy.
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Affiliation(s)
- Gui-Zhu Peng
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, Hubei 430071, P.R. China
| | - Qi-Fa Ye
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, Hubei 430071, P.R. China
| | - Ren Wang
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, Hubei 430071, P.R. China
| | - Ming-Xia Li
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, Hubei 430071, P.R. China
| | - Zi-Xuan Yang
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, Hubei 430071, P.R. China
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16
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Utilization of Superfused Cerebral Slices in Probing Muscarinic Receptor Autoregulation of Acetylcholine Release. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/978-1-4939-2858-3_12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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17
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Functional expression of choline transporter like-protein 1 (CTL1) and CTL2 in human brain microvascular endothelial cells. Neurochem Int 2015; 93:40-50. [PMID: 26746385 DOI: 10.1016/j.neuint.2015.12.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/24/2015] [Accepted: 12/27/2015] [Indexed: 11/20/2022]
Abstract
In this study, we examined the molecular and functional characterization of choline transporter in human brain microvascular endothelial cells (hBMECs). Choline uptake into hBMECs was a saturable process that was mediated by a Na(+)-independent, membrane potential and pH-dependent transport system. The cells have two different [(3)H]choline transport systems with Km values of 35.0 ± 4.9 μM and 54.1 ± 8.1 μM, respectively. Choline uptake was inhibited by choline, acetylcholine (ACh) and the choline analog hemicholinium-3 (HC-3). Various organic cations also interacted with the choline transport system. Choline transporter-like protein 1 (CTL1) and CTL2 mRNA were highly expressed, while mRNA for high-affinity choline transporter 1 (CHT1) and organic cation transporters (OCTs) were not expressed in hBMECs. CTL1 and CTL2 proteins were localized to brain microvascular endothelial cells in human brain cortical sections. Both CTL1 and CTL2 proteins were expressed on the plasma membrane and mitochondria. CTL1 and CTL2 proteins are mainly expressed in plasma membrane and mitochondria, respectively. We conclude that choline is mainly transported via an intermediate-affinity choline transport system, CTL1 and CTL2, in hBMECs. These transporters are responsible for the uptake of extracellular choline and organic cations. CTL2 participate in choline transport mainly in mitochondria, and may be the major site for the control of choline oxidation.
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18
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Beckmann J, Schubert J, Morhenn HG, Grau V, Schnettler R, Lips KS. Expression of choline and acetylcholine transporters in synovial tissue and cartilage of patients with rheumatoid arthritis and osteoarthritis. Cell Tissue Res 2015; 359:465-477. [PMID: 25418136 PMCID: PMC4320306 DOI: 10.1007/s00441-014-2036-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 10/15/2014] [Indexed: 12/20/2022]
Abstract
Increasing evidence is showing that the non-neuronal cholinergic system plays an important role in the pathology of rheumatoid arthritis (RA). Choline transport into the cell is the rate-limiting step for the synthesis of acetylcholine (ACh), which can be released directly or in vesicles from the cell. However, in the human joint little is known about choline import or the release of ACh from the cell. Thus, we analyze the expression of members of the organic cation transporter (OCT), of the newly discovered choline transporter-like (CTL) family and of classical neuronal components such as the high-affinity choline transporter (CHT1) and the vesicular ACh transporter (VAChT) in the synovium and cartilage of the human hip joint from patients with osteoarthritis (OA) and RA. OCT1, OCT3 and OCTN1 and all members of the CTL family were expressed in synovial and cartilage samples. The expression of CTL1 and CTL2 was localized in synovial macrophages and fibroblasts. CHT1 mRNA expression was detectable only in the synovium, whereas VAChT was completely absent in all samples. Therefore, in the human joint, choline transport into the cell and the release of ACh seems to be mediated mainly by members of the OCT and CTL family. Expression of transporters appears not to be influenced by the pathological state, as no differences have been detected between joints from OA or RA patients. Importantly, however, all necessary components for choline import and the release of non-neuronal ACh are present in the human joint.
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Affiliation(s)
- Janet Beckmann
- Laboratory of Experimental Trauma Surgery, Justus-Liebig University, Schubert Strasse 81, 35392, Giessen, Germany.
| | - Jan Schubert
- Laboratory of Experimental Trauma Surgery, Justus-Liebig University, Schubert Strasse 81, 35392, Giessen, Germany
| | - Hans-Georg Morhenn
- Laboratory of Experimental Trauma Surgery, Justus-Liebig University, Schubert Strasse 81, 35392, Giessen, Germany
| | - Veronika Grau
- Laboratory of Experimental Surgery, Justus-Liebig University, Giessen, German
| | - Reinhard Schnettler
- Laboratory of Experimental Trauma Surgery, Justus-Liebig University, Schubert Strasse 81, 35392, Giessen, Germany
- Department of Trauma Surgery Giessen, University Hospital of Giessen-Marburg, Giessen, German
| | - Katrin Susanne Lips
- Laboratory of Experimental Trauma Surgery, Justus-Liebig University, Schubert Strasse 81, 35392, Giessen, Germany
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19
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Palmitic acid and oleic acid differentially regulate choline transporter-like 1 levels and glycerolipid metabolism in skeletal muscle cells. Lipids 2014; 49:731-44. [PMID: 24972900 DOI: 10.1007/s11745-014-3925-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 06/16/2014] [Indexed: 12/20/2022]
Abstract
Choline is an essential nutrient required for the biosynthesis of membrane lipid phosphatidylcholine (PtdCho). Here we elucidate the mechanism of how palmitic acid (PAM) and oleic acid (OLA) regulate choline transporter-like protein 1 (CTL1/SLC44A1) function. We evaluated the mechanism of extracellular and intracellular transport of choline, and their contribution to PtdCho and other glycerolipid-diacylglycerol (DAG) and triacylglycerol (TAG) homeostasis in differentiated skeletal muscle cells. PAM reduces total and plasma membrane CTL1/SLC44A1 protein by lysosomal degradation, and limits the choline uptake while increasing DAG and TAG synthesis. OLA maintains total and plasma membrane CTL1/SLC44A1, but increases PtdCho synthesis more than PAM. OLA does not increase the rate of DAG synthesis, but does increase TAG content. Thus, the CTL1/SLC44A1 presence at the plasma membrane regulates choline requirements in accordance with the type of fatty acid. The increased PtdCho and TAG turnover by OLA stimulates cell growth and offers a specific protection mechanism from the excess of intracellular DAG and autophagy. This protection was present after OLA treatments, but not after PAM treatments. The mitochondrial choline uptake was reduced by both FA; however, the regulation is complex and guided not only by the presence of the mitochondrial CTL1/SLC44A1 protein but also by the membrane potential and general mitochondrial function.
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20
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Cukier P, Wright H, Rulfs T, Silveira LFG, Teles MG, Mendonca BB, Arnhold IJP, Heger S, Latronico AC, Ojeda SR, Brito VN. Molecular and gene network analysis of thyroid transcription factor 1 (TTF1) and enhanced at puberty (EAP1) genes in patients with GnRH-dependent pubertal disorders. Horm Res Paediatr 2014; 80:257-66. [PMID: 24051510 DOI: 10.1159/000354643] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/21/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIM TTF1 and EAP1 are transcription factors that modulate gonadotropin-releasing hormone expression. We investigated the contribution of TTF1 and EAP1 genes to central pubertal disorders. PATIENTS AND METHODS 133 patients with central pubertal disorders were studied: 86 with central precocious puberty and 47 with normosmic isolated hypogonadotropic hypogonadism. The coding region of TTF1 and EAP1 were sequenced. Variations of polyglutamine and polyalanine repeats in EAP1 were analyzed by GeneScan software. Association of TTF1 and EAP1 to genes implicated in timing of puberty was investigated by meta-network framework GeneMANIA and Cytoscape software. RESULTS Direct sequencing of the TTF1 did not reveal any mutation or polymorphisms. Four EAP1 synonymous variants were identified with similar frequencies among groups. The most common EAP1 5'-distal polyalanine genotype was the homozygous 12/12, but the genotype 12/9 was identified in 2 central precocious puberty sisters without functional alteration in EAP1 transcriptional activity. TTF1 and EAP1 were connected, via genetic networks, to genes implicated in the control of menarche. CONCLUSION No TTF1 or EAP1 germline mutations were associated with central pubertal disorders. TTF1 and EAP1 may affect puberty by changing expression in response to other members of puberty-associated gene networks, or by differentially affecting the expression of gene components of these networks.
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Affiliation(s)
- Priscilla Cukier
- Unidade de Endocrinologia do Desenvolvimento, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de São Paulo e Laboratório de Hormônios e Genética Molecular LIM/42, São Paulo, Brazil
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21
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Inazu M. Choline transporter-like proteins CTLs/SLC44 family as a novel molecular target for cancer therapy. Biopharm Drug Dispos 2014; 35:431-49. [PMID: 24532461 DOI: 10.1002/bdd.1892] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 01/31/2014] [Accepted: 02/07/2014] [Indexed: 12/13/2022]
Abstract
Choline is essential for the synthesis of the major membrane phospholipid phosphatidylcholine (PC), the methyl donor betaine and the neurotransmitter acetylcholine (ACh). Elevated levels of choline and up-regulated choline kinase activity have been detected in various cancers. Thus, the intracellular accumulation of choline through choline transporters is the rate-limiting step in phospholipid metabolism and a prerequisite for cancer cell proliferation. Previous studies have demonstrated abnormalities in choline uptake and choline phospholipid metabolism in cancer cells using the imaging of cancer with positron emission tomography (PET) and magnetic resonance spectroscopy (MRS). The aberrant choline metabolism in cancer cells is strongly correlated with their malignant progression. Using quantitative real-time PCR, the mRNA expression of choline transporters was measured, and it was found that choline transporter-like proteins CTLs/SLC44 family are highly expressed in various cancer cell lines. Choline uptake through CTLs is associated with cell viability, and the functional inhibition of CTLs could promote apoptotic cell death. Furthermore, non-neuronal cholinergic systems that include CTLs-mediated choline transport are associated with cell proliferation and their inhibition promotes apoptotic cell death in colon cancer, small cell lung cancer and human leukemic T-cells. The identification of this new CTLs-mediated choline transport system provides a potential new target for cancer therapy.
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Affiliation(s)
- Masato Inazu
- Institute of Medical Science, Department of Molecular Preventive Medicine, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan
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22
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A choline derivate-modified nanoprobe for glioma diagnosis using MRI. Sci Rep 2013; 3:1623. [PMID: 23563908 PMCID: PMC3619251 DOI: 10.1038/srep01623] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 03/15/2013] [Indexed: 12/26/2022] Open
Abstract
Gadolinium (Gd) chelate contrast-enhanced magnetic resonance imaging (MRI) is a preferred method of glioma detection and preoperative localisation because it offers high spatial resolution and non-invasive deep tissue penetration. Gd-based contrast agents, such as Gd-diethyltriaminepentaacetic acid (DTPA-Gd, Magnevist), are widely used clinically for tumor diagnosis. However, the Gd-based MRI approach is limited for patients with glioma who have an uncompromised blood-brain barrier (BBB). Moreover, the rapid renal clearance and non-specificity of such contrast agents further hinders their prevalence. We present a choline derivate (CD)-modified nanoprobe with BBB permeability, glioma specificity and a long blood half-life. Specific accumulation of the nanoprobe in gliomas and subsequent MRI contrast enhancement are demonstrated in vitro in U87 MG cells and in vivo in a xenograft nude model. BBB and glioma dual targeting by this nanoprobe may facilitate precise detection of gliomas with an uncompromised BBB and may offer better preoperative and intraoperative tumor localization.
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The choline transporter-like family SLC44: properties and roles in human diseases. Mol Aspects Med 2013; 34:646-54. [PMID: 23506897 DOI: 10.1016/j.mam.2012.10.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 03/14/2012] [Indexed: 12/18/2022]
Abstract
The Na(+)-independent, high affinity choline carrier system proposed to supply choline for the synthesis of cell membrane phospholipids was recently associated with SLC44 family members (SLC44A1-5) also called choline-like transporter family. SLC44A1 is widely expressed throughout the nervous system in both neurons and oligodendrocytes, while SLC44A2-4 are mainly detected in peripheral tissues. The subcellular localization of the proteins was mainly addressed for SLC44A1 through the development of specific antibodies. SLC44A1 is detected in both the plasma and mitochondrial membranes where the protein is able to transport choline at high affinity and in a Na(+)-independent manner. The physiological relevance of SLC44A1 as a choline carrier is indicated by its likely involvement in membrane synthesis for cell growth or repair, and also by its role in phospholipid production for the generation of lung surfactant. Moreover, an autoimmune disease has been related to the blockade of SLC44A2 function, which results in the alteration of hair cells in the inner ear and leads to autoimmune hearing loss. In the alloimmune syndrome called transfusion-related acute lung injury, antibodies to SLC44A2 cause a deleterious aggregation of granulocytes. Therefore transporters of the SLC44 family represent attractive and promising targets for therapeutic and diagnostic applications regarding both immune and degenerative diseases.
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Song P, Rekow SS, Singleton CA, Sekhon HS, Dissen GA, Zhou M, Campling B, Lindstrom J, Spindel ER. Choline transporter-like protein 4 (CTL4) links to non-neuronal acetylcholine synthesis. J Neurochem 2013; 126:451-61. [PMID: 23651124 DOI: 10.1111/jnc.12298] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 01/26/2023]
Abstract
Synthesis of acetylcholine (ACh) by non-neuronal cells is now well established and plays diverse physiologic roles. In neurons, the Na(+) -dependent, high affinity choline transporter (CHT1) is absolutely required for ACh synthesis. In contrast, some non-neuronal cells synthesize ACh in the absence of CHT1 indicating a fundamental difference in ACh synthesis compared to neurons. The aim of this study was to identify choline transporters, other than CHT1, that play a role in non-neuronal ACh synthesis. ACh synthesis was studied in lung and colon cancer cell lines focusing on the choline transporter-like proteins, a five gene family choline-transporter like protein (CTL)1-5. Supporting a role for CTLs in choline transport in lung cancer cells, choline transport was Na(+) -independent and CTL1-5 were expressed in all cells examined. CTL1, 2, and 5 were expressed at highest levels and knockdown of CTL1, 2, and 5 decreased choline transport in H82 lung cancer cells. Knockdowns of CTL1, 2, 3, and 5 had no effect on ACh synthesis in H82 cells. In contrast, knockdown of CTL4 significantly decreased ACh secretion by both lung and colon cancer cells. Conversely, increasing expression of CTL4 increased ACh secretion. These results indicate that CTL4 mediates ACh synthesis in non-neuronal cell lines and presents a mechanism to target non-neuronal ACh synthesis without affecting neuronal ACh synthesis.
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Affiliation(s)
- Pingfang Song
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon 97006, USA
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Abstract
The overproduction of β-amyloid (Aβ) fragments in transgenic APPswe/PS1dE9 mice results in formation of amyloid deposits in the cerebral cortex and hippocampus starting around four months of age and leading to cognitive impairment much later. We have previously found an age and transgene-dependent weakening of muscarinic receptor-mediated transmission that was not present in young (6-10-week-old) animals but preceded both amyloid deposits and cognitive deficits. Now we investigated immediate and prolonged in vitro effects of non-aggregated Aβ(1-42) on coupling of individual muscarinic receptor subtypes expressed in CHO (Chinese hamster ovary) cells and their underlying mechanisms. Immediate application of 1 μM Aβ(1-42) had no effect on the binding of the muscarinic antagonist N-methylscopolamine or the agonist carbachol. In contrast, 4-day treatment of CHO cells expressing the M1 muscarinic receptor with 100 nM Aβ(1-42) significantly changed the binding characteristics of the muscarinic agonist carbachol and reduced the extent of the M1 receptor-stimulated breakdown of phosphatidylinositol while it did not demonstrate overt toxic effects. The treatment had no influence on the expression of either G-proteins or muscarinic receptors. In concert, we found no change in the gene expression of muscarinic receptor subtypes and gene or protein expression of the G(s), G(q/11), and G(i/o) G-proteins in the cerebral cortex of young adult APPswe/PS1dE9 mice that demonstrate high concentrations of soluble Aβ(1-42) and impaired muscarinic receptor-mediated G-protein activation. Our results provide strong evidence that the initial injurious effects of Aβ(1-42) on M1 muscarinic receptor-mediated transmissionis is due to compromised coupling of the receptor with G(q/11) G-protein.
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Abstract
Many epithelial and endothelial cells express a cholinergic autocrine loop in which acetylcholine acts as a growth factor to stimulate cell growth. Cancers derived from these tissues similarly express a cholinergic autocrine loop and ACh secreted by the cancer or neighboring cells interacts with M3 muscarinic receptors expressed on the cancer cells to stimulate tumor growth. Primary proliferative pathways involve MAPK and Akt activation. The ability of muscarinic agonists to stimulate, and M3 antagonists to inhibit tumor growth has clearly been demonstrated for lung and colon cancer. The ability of muscarinic agonists to stimulate growth has been shown for melanoma, pancreatic, breast, ovarian, prostate and brain cancers, suggesting that M3 antagonists will also inhibit growth of these tumors as well. As yet no clinical trials have proven the efficacy of M3 antagonists as cancer therapeutics, though the widespread clinical use and low toxicity of M3 antagonists support the potential role of these drugs as adjuvants to current cancer therapies.
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Affiliation(s)
- Eliot R Spindel
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
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Yamada T, Inazu M, Tajima H, Matsumiya T. Functional expression of choline transporter-like protein 1 (CTL1) in human neuroblastoma cells and its link to acetylcholine synthesis. Neurochem Int 2010; 58:354-65. [PMID: 21185344 DOI: 10.1016/j.neuint.2010.12.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 12/03/2010] [Accepted: 12/09/2010] [Indexed: 01/11/2023]
Abstract
We examined the molecular and functional characterization of choline uptake into human neuroblastoma cell lines (SH-SY5Y: non-cholinergic and LA-N-2: cholinergic neuroblastoma), and the association between choline transport and acetylcholine (ACh) synthesis in these cells. Choline uptake was saturable and mediated by a single transport system. Removal of Na(+) from the uptake buffer strongly enhanced choline uptake. Choline uptake was inhibited by the choline analogue hemicholinium-3 (HC-3) and various organic cations, and was significantly decreased by acidification of the extracellular medium. The increase in choline uptake under Na(+)-free conditions was inhibited by a Na(+)/H(+) exchanger (NHE) inhibitor. Real-time PCR revealed that choline transporter-like protein 1 (CTL1), NHE1 and NHE5 mRNA are mainly expressed. Western blot and immunocytochemical analysis indicated that CTL1 protein was expressed in plasma membrane. ChAT mRNA was expressed at a much higher level in LA-N-2 cells than in SH-SY5Y cells. The conversion of choline to ACh was confirmed in both cells, and was enhanced in Na(+)-free conditions. These findings suggest that CTL1 is functionally expressed in both SH-SY5Y and LA-N-2 cells and is responsible for choline uptake that relies on a directed H(+) gradient as a driving force, and this transport functions in co-operation with NHE1 and NHE5. Furthermore, choline uptake through CTL1 is associated with ACh synthesis in cholinergic neuroblastoma cells.
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Affiliation(s)
- Tomoko Yamada
- Department of Pharmacology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
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Kommareddi PK, Nair TS, Thang LV, Galano MM, Babu E, Ganapathy V, Kanazawa T, McHugh JB, Carey TE. Isoforms, expression, glycosylation, and tissue distribution of CTL2/SLC44A2. Protein J 2010; 29:417-26. [PMID: 20665236 DOI: 10.1007/s10930-010-9268-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Antibodies to the solute carrier protein, CTL2/SLC44A2, cause hearing loss in animals, are frequently found in autoimmune hearing loss patients, and are implicated in transfusion-related acute lung injury. We cloned a novel CTL2/SLC44A2 isoform (CTL2 P1) from inner ear and identified an alternate upstream promoter and exon 1a encoding a protein of 704 amino acids which differs in the first 10-12 amino acids from the known exon 1b isoform (CTL2 P2; 706 amino acids). The expression of these CTL2/SLC44A2 isoforms, their posttranslational modifications in tissues and their localization in HEK293 cells expressing rHuCTL2/SLC44A2 were assessed. P1 and P2 isoforms with differing glycosylation are variably expressed in cochlea, tongue, heart, colon, lung, kidney, liver and spleen suggesting tissue specific differences that may influence function in each tissue. Because antibodies to CTL2/SLC44A2 have serious pathologic consequences, it is important to understand its distribution and modifications. Heterologous expression in X. laevis oocytes shows that while human CTL2-P1 does not transport choline, human CTL2-P2 exhibits detectable choline transport activity.
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Affiliation(s)
- P K Kommareddi
- Kresge Hearing Research Institute, Department of Otolaryngology/Head and Neck Surgery, The University of Michigan, 1150 West Medical Center Drive, Room 5311 Medical Science I, Ann Arbor, MI 48109-5516, USA
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Brandes AH, Ward CS, Ronen SM. 17-allyamino-17-demethoxygeldanamycin treatment results in a magnetic resonance spectroscopy-detectable elevation in choline-containing metabolites associated with increased expression of choline transporter SLC44A1 and phospholipase A2. Breast Cancer Res 2010; 12:R84. [PMID: 20946630 PMCID: PMC3096977 DOI: 10.1186/bcr2729] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Accepted: 10/14/2010] [Indexed: 01/18/2023] Open
Abstract
Introduction 17-allyamino-17-demethoxygeldanamycin (17-AAG), a small molecule inhibitor of Hsp90, is currently in clinical trials in breast cancer. However, 17-AAG treatment often results in inhibition of tumor growth rather than shrinkage, making detection of response a challenge. Magnetic resonance spectroscopy (MRS) and spectroscopic imaging (MRSI) are noninvasive imaging methods than can be used to monitor metabolic biomarkers of drug-target modulation. This study set out to examine the MRS-detectable metabolic consequences of Hsp90 inhibition in a breast cancer model. Methods MCF-7 breast cancer cells were investigated, and MRS studies were performed both on live cells and on cell extracts. 31P and 1H MRS were used to determine total cellular metabolite concentrations and 13C MRS was used to probe the metabolism of [1,2-13C]-choline. To explain the MRS metabolic findings, microarray and RT-PCR were used to analyze gene expression, and in vitro activity assays were performed to determine changes in enzymatic activity following 17-AAG treatment. Results Treatment of MCF-7 cells with 17-AAG for 48 hours caused a significant increase in intracellular levels of choline (to 266 ± 18% of control, P = 0.05) and phosphocholine (PC; to 181 ± 10% of control, P = 0.001) associated with an increase in expression of choline transporter SLC44A1 and an elevation in the de novo synthesis of PC. We also detected an increase in intracellular levels of glycerophosphocholine (GPC; to 176 ± 38% of control, P = 0.03) associated with an increase in PLA2 expression and activity. Conclusions This study determined that in the MCF-7 breast cancer model inhibition of Hsp90 by 17-AAG results in a significant MRS-detectable increase in choline, PC and GPC, which is likely due to an increase in choline transport into the cell and phospholipase activation. 1H MRSI can be used in the clinical setting to detect levels of total choline-containing metabolite (t-Cho, composed of intracellular choline, PC and GPC). As Hsp90 inhibitors enter routine clinical use, t-Cho could thus provide an easily detectable, noninvasive metabolic biomarker of Hsp90 inhibition in breast cancer patients.
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Affiliation(s)
- Alissa H Brandes
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, 94158, USA
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