1
|
Xia Y, Wang X, Lin S, Dong TTX, Tsim KWK. Berberine and palmatine, acting as allosteric potential ligands of α7 nAChR, synergistically regulate inflammation and phagocytosis of microglial cells. FASEB J 2024; 38:e70094. [PMID: 39373933 DOI: 10.1096/fj.202302538rrrr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 09/10/2024] [Accepted: 09/23/2024] [Indexed: 10/08/2024]
Abstract
Berberine and palmatine are isoquinoline quaternary alkaloids derived from Chinese medicinal herbs. These alkaloids have shown promising synergy in inhibiting acetylcholinesterase (AChE), indicating their potential in treating Alzheimer's disease (AD). Besides, the anti-inflammatory effects of berberine and palmatine have been widely reported, although the underlying mechanism remains unclear. Here, we found that berberine and palmatine could induce calcium ion (Ca2+) influx via activating α7 nicotinic acetylcholine receptor (α7 nAChR) in cultured microglial cells, possibly serving as its allosteric potential ligands. Furthermore, we examined the synergistic anti-inflammatory effects of berberine and palmatine in the LPS-induced microglia, that significantly suppressed the production of TNF-α and iNOS. Notably, this suppression was reversed by co-treatment with a selective antagonist of α7 nAChR. Moreover, the alkaloid-induced microglial phagocytosis was shown to be mediated by the induction of Ca2+ influx through α7 nAChR and subsequent CaMKII-Rac1-dependent pathway. Additionally, the combination of berberine and palmatine, at low concentration, protected against the LPS-induced endoplasmic reticulum stress and mitochondrial dysfunction in microglia. These findings indicate the potential of berberine and palmatine, either individually or in combination, in contributing to anti-AD drug development, which provide valuable insights into the mechanisms by which natural products, such as plant alkaloids, exert their anti-AD effects.
Collapse
Affiliation(s)
- Yingjie Xia
- Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, SRI, The Hong Kong University of Science and Technology, Shenzhen, China
| | - Xiaoyang Wang
- Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, SRI, The Hong Kong University of Science and Technology, Shenzhen, China
| | - Shengying Lin
- Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, SRI, The Hong Kong University of Science and Technology, Shenzhen, China
| | - Tina T X Dong
- Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, SRI, The Hong Kong University of Science and Technology, Shenzhen, China
| | - Karl W K Tsim
- Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, SRI, The Hong Kong University of Science and Technology, Shenzhen, China
| |
Collapse
|
2
|
Presenilin 1 Modulates Acetylcholinesterase Trafficking and Maturation. Int J Mol Sci 2023; 24:ijms24021437. [PMID: 36674948 PMCID: PMC9864477 DOI: 10.3390/ijms24021437] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
In Alzheimer's disease (AD), the reduction in acetylcholinesterase (AChE) enzymatic activity is not paralleled with changes in its protein levels, suggesting the presence of a considerable enzymatically inactive pool in the brain. In the present study, we validated previous findings, and, since inactive forms could result from post-translational modifications, we analyzed the glycosylation of AChE by lectin binding in brain samples from sporadic and familial AD (sAD and fAD). Most of the enzymatically active AChE was bound to lectins Canavalia ensiformis (Con A) and Lens culinaris agglutinin (LCA) that recognize terminal mannoses, whereas Western blot assays showed a very low percentage of AChE protein being recognized by the lectin. This indicates that active and inactive forms of AChE vary in their glycosylation pattern, particularly in the presence of terminal mannoses in active ones. Moreover, sAD subjects showed reduced binding to terminal mannoses compared to non-demented controls, while, for fAD patients that carry mutations in the PSEN1 gene, the binding was higher. The role of presenilin-1 (PS1) in modulating AChE glycosylation was then studied in a cellular model that overexpresses PS1 (CHO-PS1). In CHO-PS1 cells, binding to LCA indicates that AChE displays more terminal mannoses in oligosaccharides with a fucosylated core. Immunocytochemical assays also demonstrated increased presence of AChE in the trans-Golgi. Moreover, AChE enzymatic activity was higher in plasmatic membrane of CHO-PS1 cells. Thus, our results indicate that PS1 modulates trafficking and maturation of AChE in Golgi regions favoring the presence of active forms in the membrane.
Collapse
|
3
|
de Souza SS, Freitas ÍN, Gonçalves SDO, Luz TMD, Araújo APDC, Rajagopal R, Balasubramani G, Rahman MM, Malafaia G. Toxicity induced via ingestion of naturally-aged polystyrene microplastics by a small-sized terrestrial bird and its potential role as vectors for the dispersion of these pollutants. JOURNAL OF HAZARDOUS MATERIALS 2022; 434:128814. [PMID: 35427965 DOI: 10.1016/j.jhazmat.2022.128814] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 03/23/2022] [Accepted: 03/26/2022] [Indexed: 06/14/2023]
Abstract
In recent years, there has been a growing number of studies on the impact of microplastics (MPs) on biota. However, its effects on birds' health are poorly understood. Thus, we aimed to evaluate the possible effects of ingestion of naturally-aged MPs by Coturnix Coturnix japonica (11 and 22 MP particles/day/bird, once a day, for 9 days), from different toxicity biomarkers. At the end of the experiment, it was found that the ingested MPs in birds showed a significant reduction in body biomass. Also, an increase in malondialdehyde production in the liver, brain, intestine, and gizzard of the birds, as well as a suppressive effect on hepatic nitric oxide production and superoxide dismutase activity in the liver and intestine were observed. Cerebral catalase activity was reduced in birds exposed to MPs and the cholinesterasic effect (marked by increased acetylcholinesterase activity) was observed in the muscle and brain of these animals. Despite these differences, through the main component analysis, hierarchical clustering analysis, and integrated biomarker response assessment, we observed similar toxicological effects in birds exposed to different amounts of MPs. In addition, the size of MPs was reduced, and their shape was altered as they transited through the gastrointestinal system, which probably explains their accumulation in the liver of birds. An expressive number of MPs are released through the feces of the birds throughout the experiment. As far as we know, this is the first report that associates MPs ingestion by small-sized terrestrial birds with biochemical alterations viz., predictive of oxidative stress, redox imbalance, and cholinesterasic effect, in addition to shedding light on the potential role of these birds as vectors for dispersal of MPs in natural environments.
Collapse
Affiliation(s)
- Sindoval Silva de Souza
- Laboratory of Toxicology Applied to the Environment, Goiano Federal Institute, Urutaí, GO, Brazil; Post-Graduation Program in Conservation of Cerrado Natural Resources, Goiano Federal Institute, Urutaí, GO, Brazil
| | - Ítalo Nascimento Freitas
- Laboratory of Toxicology Applied to the Environment, Goiano Federal Institute, Urutaí, GO, Brazil
| | | | - Thiarlen Marinho da Luz
- Laboratory of Toxicology Applied to the Environment, Goiano Federal Institute, Urutaí, GO, Brazil
| | - Amanda Pereira da Costa Araújo
- Laboratory of Toxicology Applied to the Environment, Goiano Federal Institute, Urutaí, GO, Brazil; Post-Graduation Program in Environmental Sciences, Federal University of Goiás, Goiânia, Brazil
| | - Rajakrishnan Rajagopal
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Govindasamy Balasubramani
- Division of Research and Innovation, Department of Biotechnology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Sriperambudur, 600124 Tamil Nadu, India
| | - Md Mostafizur Rahman
- Department of Environmental Sciences, Jahangirnagar University, Dhaka 1342, Bangladesh; Laboratory of Environmental Health and Ecotoxicology, Department of Environmental Sciences, Jahangirnagar University, Dhaka 1342, Bangladesh
| | - Guilherme Malafaia
- Laboratory of Toxicology Applied to the Environment, Goiano Federal Institute, Urutaí, GO, Brazil; Post-Graduation Program in Conservation of Cerrado Natural Resources, Goiano Federal Institute, Urutaí, GO, Brazil; Post-Graduation Program in Ecology, Conservation, and Biodiversity, Federal University of Uberlândia, Uberlândia, MG, Brazil; Post-Graduation Program in Biotechnology and Biodiversity, Federal University of Goiás, Goiânia, GO, Brazil.
| |
Collapse
|
4
|
Butyrylcholinesterase-Protein Interactions in Human Serum. Int J Mol Sci 2021; 22:ijms221910662. [PMID: 34639003 PMCID: PMC8508650 DOI: 10.3390/ijms221910662] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 11/17/2022] Open
Abstract
Measuring various biochemical and cellular components in the blood is a routine procedure in clinical practice. Human serum contains hundreds of diverse proteins secreted from all cells and tissues in healthy and diseased states. Moreover, some serum proteins have specific strong interactions with other blood components, but most interactions are probably weak and transient. One of the serum proteins is butyrylcholinesterase (BChE), an enzyme existing mainly as a glycosylated soluble tetramer that plays an important role in the metabolism of many drugs. Our results suggest that BChE interacts with plasma proteins and forms much larger complexes than predicted from the molecular weight of the BChE tetramer. To investigate and isolate such complexes, we developed a two-step strategy to find specific protein–protein interactions by combining native size-exclusion chromatography (SEC) with affinity chromatography with the resin that specifically binds BChE. Second, to confirm protein complexes′ specificity, we fractionated blood serum proteins by density gradient ultracentrifugation followed by co-immunoprecipitation with anti-BChE monoclonal antibodies. The proteins coisolated in complexes with BChE were identified by mass spectroscopy. These binding studies revealed that BChE interacts with a number of proteins in the human serum. Some of these interactions seem to be more stable than transient. BChE copurification with ApoA-I and the density of some fractions containing BChE corresponding to high-density lipoprotein cholesterol (HDL) during ultracentrifugation suggest its interactions with HDL. Moreover, we observed lower BChE plasma activity in individuals with severely reduced HDL levels (≤20 mg/dL). The presented two-step methodology for determination of the BChE interactions can facilitate further analysis of such complexes, especially from the brain tissue, where BChE could be involved in the pathogenesis and progression of AD.
Collapse
|
5
|
Analysis of Acetylcholinesterase Activity in Cell Membrane Microarrays of Brain Areas as a Screening Tool to Identify Tissue Specific Inhibitors. ANALYTICA 2021. [DOI: 10.3390/analytica2010003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Acetylcholinesterase (AChE) is responsible for hydrolyzing the acetylcholine neurotransmitter, bringing an end point to cholinergic neurotransmission. Thus, AChE is the primary target of a wide spectrum of compounds used as pesticides, nerve agents or therapeutic drugs for neurodegenerative diseases such as Alzheimer’s disease (AD). This enzyme is heterogeneously distributed in the brain showing different activity depending on the nervous region. Therefore, the aim of this work is to report a novel technology that enables the simultaneous determination of tissue specific AChE activity, as well as the analysis and screening of specific inhibitors, by using cell membrane microarrays. These microarrays were composed of cell membranes, isolated from 41 tissues, organs and brain areas, that were immobilized over a slide, maintaining the functionality of membrane proteins. To validate this platform, demonstrating its usefulness in drug discovery as a high throughput screening tool, a colorimetric protocol to detect the membrane-bound AChE activity was optimized. Thus, rat cortical and striatal AChE activities were estimated in presence of increased concentrations of AChE inhibitors, and the donepezil effect was assessed simultaneously in 41 tissues and organs, demonstrating the major potential of this microarray’s technology.
Collapse
|
6
|
Xu ML, Luk WK, Liu EY, Kong XP, Wu QY, Xia YJ, Dong TT, Tsim KW. Differentiation of erythroblast requires the dimeric form of acetylcholinesterase: Interference with erythropoietin receptor. Chem Biol Interact 2019; 308:317-322. [DOI: 10.1016/j.cbi.2019.06.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/24/2019] [Accepted: 06/03/2019] [Indexed: 12/14/2022]
|
7
|
Marinho CS, Matias MVF, Brandão IGF, Santos EL, Machado SS, Zanta CLPS. Characterization and kinetic study of the brain and muscle acetylcholinesterase from Danio rerio. Comp Biochem Physiol C Toxicol Pharmacol 2019; 222:11-18. [PMID: 30981910 DOI: 10.1016/j.cbpc.2019.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 03/09/2019] [Accepted: 04/08/2019] [Indexed: 11/26/2022]
Abstract
Acetylcholinesterase (AChE) plays an important role in the therapy of Alzheimer's disease and in the detection of pesticides such as organophosphates which are also widely used in chemical warfare. The aim of this study is the physicochemical and kinetic characterization of brain and muscle ChE from Danio rerio (Zebrafish). Optimal activity was found for brain ChE at alkaline pH 9.0 at 30 °C, and for muscle ChE at alkaline pH 8.5 at temperatures between 20 °C and 35 °C. The apparent kinetic constants, Kmapp and Vmaxapp, for brain ChE were determined as 0.191 ± 0.024 mM and 0.566 ± 0.028 U/mg protein, and for muscle ChE as 0.230 ± 0.030 mM and 0.677 ± 0.039 U/mg protein. Both brain and muscle ChE showed inhibition at high substrate concentrations. Brain and muscle ChE showed IC50 values for physostigmine of 0.61 μM and 0.37 μM, respectively. The ChE activity in brain was significantly inhibited by BW254c51 in all concentrations tested, but not by Iso-OMPA, while muscle ChE presented a moderate decrease (13 to 29%) in the activity values, indicating that BuChE is present.
Collapse
Affiliation(s)
- Claudiane S Marinho
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
| | - Marcos V F Matias
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
| | - Iago G F Brandão
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
| | - Elton L Santos
- Federal University of Alagoas, Agricultural Sciences Center, BR-104, Rio Largo, AL, Brazil
| | - Sonia S Machado
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil.
| | - Carmem L P S Zanta
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
| |
Collapse
|
8
|
Boyko KM, Baymukhametov TN, Chesnokov YM, Hons M, Lushchekina SV, Konarev PV, Lipkin AV, Vasiliev AL, Masson P, Popov VO, Kovalchuk MV. 3D structure of the natural tetrameric form of human butyrylcholinesterase as revealed by cryoEM, SAXS and MD. Biochimie 2019; 156:196-205. [DOI: 10.1016/j.biochi.2018.10.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 10/24/2018] [Indexed: 12/13/2022]
|
9
|
Wu Q, Fung AHY, Xu ML, Poon K, Liu EYL, Kong XP, Yao P, Xiong QP, Dong TTX, Tsim KWK. Microphthalmia-associated transcription factor up-regulates acetylcholinesterase expression during melanogenesis of murine melanoma cells. J Biol Chem 2018; 293:14417-14428. [PMID: 30076217 DOI: 10.1074/jbc.ra118.003729] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/29/2018] [Indexed: 11/06/2022] Open
Abstract
Acetylcholinesterase (AChE) hydrolyzes the neurotransmitter acetylcholine in neurons. However, AChE has been proposed to also have nonneuronal functions in different cell types. Here, we report that AChE is expressed in melanocytes and melanoma cells, and that the tetrameric (G4) form is the major AChE isoform in these cells. During melanogenesis of B16F10 murine melanoma cells, AChE levels decreased markedly. The differentiation of melanoma cells led to (i) an increase in melanin and tyrosinase, (ii) a change in intracellular cAMP levels, and (iii) a decrease in microphthalmia-associated transcription factor (MITF). We hypothesized that the regulation of AChE during melanogenesis is mediated by two transcription factors: cAMP-response element-binding protein (CREB) and MITF. In melanoma cells, exogenous cAMP suppressed AChE expression and the promoter activity of the ACHE gene. This suppression was mediated by a cAMP-response element (CRE) located on the ACHE promoter, as mutation of CRE relieved the suppression. In melanoma, MITF overexpression induced ACHE transcription, and mutation of an E-box site in human ACHE promoter blocked this induction. An AChE inhibitor greatly enhanced acetylcholine-mediated responses of melanogenic gene expression levels in vitro; however, this enhancement was not observed in the presence of agonists of the muscarinic acetylcholine receptor. These results indicate that ACHE transcription is regulated by cAMP-dependent signaling during melanogenesis of B16F10 cells, and the effect of this enzyme on melanin production suggests that it has a potential role in skin pigmentation.
Collapse
Affiliation(s)
- Qiyun Wu
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Aster H Y Fung
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Miranda L Xu
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Kaman Poon
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Etta Y L Liu
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Xiang P Kong
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and
| | - Ping Yao
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Qing P Xiong
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Tina T X Dong
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and.,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Karl W K Tsim
- From the Shenzhen Key Laboratory of Edible and Medicinal Bioresources, Shenzhen Research Institute, Shenzhen, 518000, China and .,Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| |
Collapse
|
10
|
Thurner M, Asim F, Garczarczyk-Asim D, Janke K, Deutsch M, Margreiter E, Troppmair J, Marksteiner R. Development of an in vitro potency assay for human skeletal muscle derived cells. PLoS One 2018; 13:e0194561. [PMID: 29566057 PMCID: PMC5864011 DOI: 10.1371/journal.pone.0194561] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 03/04/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Potency is a quantitative measure of the desired biological function of an advanced therapy medicinal product (ATMP) and is a prerequisite for market approval application (MAA). To assess the potency of human skeletal muscle-derived cells (SMDCs), which are currently investigated in clinical trials for the regeneration of skeletal muscle defects, we evaluated acetylcholinesterase (AChE), which is expressed in skeletal muscle and nervous tissue of all mammals. METHODS CD56+ SMDCs were separated from CD56- SMDCs by magnetic activated cell sorting (MACS) and both differentiated in skeletal muscle differentiation medium. AChE activity of in vitro differentiated SMDCs was correlated with CD56 expression, fusion index, cell number, cell doubling numbers, differentiation markers and compared to the clinical efficacy in patients treated with SMDCs against fecal incontinence. RESULTS CD56- SMDCs did not form multinucleated myotubes and remained low in AChE activity during differentiation. CD56+ SMDCs generated myotubes and increased in AChE activity during differentiation. AChE activity was found to accurately reflect the number of CD56+ SMDCs in culture, their fusion competence, and cell doubling number. In patients with fecal incontinence responding to SMDCs treatment, the improvement of clinical symptoms was positively linked with the AChE activity of the SMDCs injected. DISCUSSION AChE activity was found to truly reflect the in vitro differentiation status of SMDCs and to be superior to the mere use of surface markers as it reflects not only the number of myogenic SMDCs in culture but also their fusion competence and population doubling number, thus combining cell quality and quantification of the expected mode of action (MoA) of SMDCs. Moreover, the successful in vitro validation of the assay proves its suitability for routine use. Most convincingly, our results demonstrate a link between clinical efficacy and the AChE activity of the SMDCs preparations used for the treatment of fecal incontinence. Thus, we recommend using AChE activity of in vitro differentiated SMDCs as a potency measure in end stage (phase III) clinical trials using SMDCs for skeletal muscle regeneration and subsequent market approval application (MAA).
Collapse
Affiliation(s)
- Marco Thurner
- Innovacell Biotechnologie AG, Science Park, Innsbruck, Austria
- Daniel Swarovski Research Laboratory, Department of Visceral, Transplant, and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
- * E-mail: ,
| | - Faheem Asim
- Innovacell Biotechnologie AG, Science Park, Innsbruck, Austria
| | | | - Katrin Janke
- Innovacell Biotechnologie AG, Science Park, Innsbruck, Austria
| | - Martin Deutsch
- Innovacell Biotechnologie AG, Science Park, Innsbruck, Austria
| | - Eva Margreiter
- Innovacell Biotechnologie AG, Science Park, Innsbruck, Austria
| | - Jakob Troppmair
- Daniel Swarovski Research Laboratory, Department of Visceral, Transplant, and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | | |
Collapse
|
11
|
Pai PJ, Hu Y, Lam H. Direct glycan structure determination of intact N-linked glycopeptides by low-energy collision-induced dissociation tandem mass spectrometry and predicted spectral library searching. Anal Chim Acta 2016; 934:152-62. [DOI: 10.1016/j.aca.2016.05.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/24/2016] [Accepted: 05/30/2016] [Indexed: 11/24/2022]
|
12
|
Lau KM, Gong AGW, Xu ML, Lam CTW, Zhang LML, Bi CWC, Cui D, Cheng AWM, Dong TTX, Tsim KWK, Lin H. Transcriptional activity of acetylcholinesterase gene is regulated by DNA methylation during C2C12 myogenesis. Brain Res 2016; 1642:114-123. [PMID: 27021952 DOI: 10.1016/j.brainres.2016.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/25/2016] [Accepted: 03/15/2016] [Indexed: 12/26/2022]
Abstract
The expression of acetylcholinesterase (AChE), an enzyme hydrolyzes neurotransmitter acetylcholine at vertebrate neuromuscular junction, is regulated during myogenesis, indicating the significance of muscle intrinsic factors in controlling the enzyme expression. DNA methylation is essential for temporal control of myogenic gene expression during myogenesis; however, its role in AChE regulation is not known. The promoter of vertebrate ACHE gene carries highly conserved CG-rich regions, implying its likeliness to be methylated for epigenetic regulation. A DNA methyltransferase inhibitor, 5-azacytidine (5-Aza), was applied onto C2C12 cells throughout the myotube formation. When DNA methylation was inhibited, the promoter activity, transcript expression and enzymatic activity of AChE were markedly increased after day 3 of differentiation, which indicated the putative role of DNA methylation. By bisulfite pyrosequencing, the overall methylation rate was found to peak at day 3 during C2C12 cell differentiation; a SP1 site located at -1826bp upstream of mouse ACHE gene was revealed to be heavily methylated. The involvement of transcriptional factor SP1 in epigenetic regulation of AChE was illustrated here: (i) the SP1-driven transcriptional activity was increased in 5-Aza-treated C2C12 culture; (ii) the binding of SP1 onto the SP1 site of ACHE gene was fully blocked by the DNA methylation; and (iii) the sequence flanking SP1 sites of ACHE gene was precipitated by chromatin immuno-precipitation assay. The findings suggested the role of DNA methylation on AChE transcriptional regulation and provided insight in elucidating the DNA methylation-mediated regulatory mechanism on AChE expression during muscle differentiation.
Collapse
Affiliation(s)
- Kei M Lau
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Amy G W Gong
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Miranda L Xu
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Candy T W Lam
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Laura M L Zhang
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Cathy W C Bi
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - D Cui
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Anthony W M Cheng
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Tina T X Dong
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Karl W K Tsim
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China.
| | - Huangquan Lin
- Division of Life Science and Center of Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China.
| |
Collapse
|
13
|
Radiometric assay of ghrelin hydrolase activity and 3H-ghrelin distribution into mouse tissues. Biochem Pharmacol 2015; 98:732-9. [PMID: 26514871 DOI: 10.1016/j.bcp.2015.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/21/2015] [Indexed: 11/24/2022]
Abstract
A high-throughput radiometric assay was developed to characterize enzymatic hydrolysis of ghrelin and to track the peptide's fate in vivo. The assay is based on solvent partitioning of [(3)H]-octanoic acid liberated from [(3)H]-octanoyl ghrelin during enzymatic hydrolysis. This simple and cost-effective method facilitates kinetic analysis of ghrelin hydrolase activity of native and mutated butyrylcholinesterases or carboxylesterases from multiple species. In addition, the assay's high sensitivity facilitates ready evaluation of ghrelin's pharmacokinetics and tissue distribution in mice after i.v. bolus administration of radiolabeled peptide.
Collapse
|
14
|
Ruiz CA, Rossi SG, Rotundo RL. Rescue and Stabilization of Acetylcholinesterase in Skeletal Muscle by N-terminal Peptides Derived from the Noncatalytic Subunits. J Biol Chem 2015; 290:20774-20781. [PMID: 26139603 PMCID: PMC4543640 DOI: 10.1074/jbc.m115.653741] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/29/2015] [Indexed: 11/06/2022] Open
Abstract
The vast majority of newly synthesized acetylcholinesterase (AChE) molecules do not assemble into catalytically active oligomeric forms and are rapidly degraded intracellularly by the endoplasmic reticulum-associated protein degradation pathway. We have previously shown that AChE in skeletal muscle is regulated in part post-translationally by the availability of the noncatalytic subunit collagen Q, and others have shown that expression of a 17-amino acid N-terminal proline-rich attachment domain of collagen Q is sufficient to promote AChE tetramerization in cells producing AChE. In this study we show that muscle cells, or cell lines expressing AChE catalytic subunits, incubated with synthetic proline-rich attachment domain peptides containing the endoplasmic reticulum retrieval sequence KDEL take up and retrogradely transport them to the endoplasmic reticulum network where they induce assembly of AChE tetramers. The peptides act to enhance AChE folding thereby rescuing them from reticulum degradation. This enhanced folding efficiency occurs in the presence of inhibitors of protein synthesis and in turn increases total cell-associated AChE activity and active tetramer secretion. Pulse-chase studies of isotopically labeled AChE molecules show that the enzyme is rescued from intracellular degradation. These studies provide a mechanistic explanation for the large scale intracellular degradation of AChE previously observed and indicate that simple peptides alone can increase the production and secretion of this critical synaptic enzyme in muscle tissue.
Collapse
Affiliation(s)
- Carlos A Ruiz
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Susana G Rossi
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Richard L Rotundo
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, Florida 33136; Department of Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida 33136.
| |
Collapse
|
15
|
Xu ML, Luk WKW, Lau KM, Bi CWC, Cheng AWM, Gong AGW, Lin H, Tsim KWK. Three N-Glycosylation Sites of Human Acetylcholinesterase Shares Similar Glycan Composition. J Mol Neurosci 2015; 57:486-91. [PMID: 26231935 DOI: 10.1007/s12031-015-0629-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/21/2015] [Indexed: 11/29/2022]
Abstract
Acetylcholinesterase (AChE; EC 3.1.1.7) is a glycoprotein possessing three conserved N-linked glycosylation sites in mammalian species, locating at 296, 381, and 495 residues of the human sequence. Several lines of evidence demonstrated that N-glycosylation of AChE affected the enzymatic activity, as well as its biosynthesis. In order to determine the role of three N-glycosylation sites in AChE activity and glycan composition, the site-directed mutagenesis of N-glycosylation sites in wild-type human AChE(T) sequence was employed to generate the single-site mutants (i.e., AChE(T) (N296Q), AChET (N381Q), and AChE(T) (N495Q)) and all site mutant (i.e., AChE(T) (3N→3Q)). The mutation did not affect AChE protein expression in the transfected cells. The mutants, AChE(T) (3N→3Q) and AChE(T) (N381Q), showed very minimal enzymatic activity, while the other mutants showed reduced activity. By binding to lectins, Con A, and SNA, the glycosylation profile was revealed in those mutated AChE. The binding affinity with lectins showed no significant difference between various N-glycosylation mutants, which suggested that similar glycan composition should be resulted from different N-glycosylation sites. Although the three glycosylation sites within AChE sequence have different extent in affecting the enzymatic activity, their glycan compositions are very similar.
Collapse
Affiliation(s)
- Miranda L Xu
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Wilson K W Luk
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Kei M Lau
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Cathy W C Bi
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Anthony W M Cheng
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Amy G W Gong
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Huangquan Lin
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | - Karl W K Tsim
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China.
| |
Collapse
|
16
|
Sánchez S, Vera B, Montagna C, Magnarelli G. Characterization of placental cholinesterases and activity induction associated to environmental organophosphate exposure. Toxicol Rep 2014; 2:437-442. [PMID: 28962379 PMCID: PMC5598449 DOI: 10.1016/j.toxrep.2014.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 02/04/2023] Open
Abstract
Although non-innervated, the placenta contains both cholinesterases (ChEs), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE). These enzymes are well-known for their multiple molecular forms. In a first approach, we used recognized specific inhibitors, substrate preferences and non-denaturating gel electrophoresis in order to characterize the ChE profile of term placenta from uncomplicated pregnancy. Results strongly suggest that the predominant cholinesterasic form present was tetrameric BChE. It is well established that both ChEs are targets of cholinesterase-inhibiting organophosphates (OP), one of the most important classes of chemicals actively applied to the environment. However, we have previously reported increased ChEs activity in placenta of rural residents exposed to OP. In the present work, we have studied: 1) whether this finding was reproducible and, 2) whether AChE or BChE up regulation is behind the increase of placental ChE activity. The population studied included forty healthy women who live in an agricultural area. Samples were collected during both the OP pulverization period (PP) and the recess period (RP). The placental ChEs activity increased in PP, evidencing reproducibility of previous results. The analysis of non-denaturating gels revealed that increased activity of total ChE activity in placenta from women exposed to OP may be attributable to tetrameric BChE up-regulation.
Collapse
Key Words
- ACh, acetylcholine
- AChE, acetylcholinesterase
- ASCh, acetylthiocholine iodide
- Acetylcholinesterase
- BChE, butyrylcholinesterase
- BSCh, butyrylthiocholine iodide
- BW284C51, 1,5-bis (4-allyldimethyl ammoniumphenyl)-pentan-3-one dibromide
- Butyrylcholinesterase
- ChE, cholinesterase
- ChEs, cholinesterases
- OP, organophosphates
- Organophosphates
- PP, pulverization period
- Placenta
- RP, recess period
- iso-OMPA, tetraisopropylpyrophosphoramide
Collapse
Affiliation(s)
- S. Sánchez
- Facultad de CienciasMédicas, Universidad NacionaldelComahue, Cipolletti, Río Negro, Argentina
| | - B. Vera
- LIBIQUIMA, Facultad de Ingeniería, Universidad NacionaldelComahue, Neuquén, Argentina
- Facultad de CienciasMédicas, Universidad NacionaldelComahue, Cipolletti, Río Negro, Argentina
| | - C. Montagna
- LIBIQUIMA, Facultad de Ingeniería, Universidad NacionaldelComahue, Neuquén, Argentina
- Facultad de CienciasdelAmbiente y la Salud, Universidad Nacional del Comahue, Neuquén, Argentina
| | - G. Magnarelli
- LIBIQUIMA, Facultad de Ingeniería, Universidad NacionaldelComahue, Neuquén, Argentina
- Facultad de CienciasMédicas, Universidad NacionaldelComahue, Cipolletti, Río Negro, Argentina
| |
Collapse
|
17
|
Bi CWC, Luk WKW, Campanari ML, Liu YH, Xu L, Lau KM, Xu ML, Choi RCY, Sáez-Valero J, Tsim KWK. Quantification of the transcripts encoding different forms of AChE in various cell types: real-time PCR coupled with standards in revealing the copy number. J Mol Neurosci 2014; 53:461-8. [PMID: 24385197 DOI: 10.1007/s12031-013-0210-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 12/10/2013] [Indexed: 01/05/2023]
Abstract
Acetylcholinesterase (AChE) is encoded by a single gene, and the alternative splicing at the 3' end produces different isoforms, including tailed (AChET), read-through (AChER), and hydrophobic (AChEH). Different forms of this enzyme exist in different cell types. Each AChE form has been proposed to have unique function, and all of them could be found in same cell type. Thus, the splicing process of different AChE forms remains unclear. Here, we aimed to establish a quantification method in measuring the absolute amount of each AChE splicing variants within a cell type. By using real-time PCR coupled with standard curves of defined copy of AChE variants, the copies of AChET transcript per 100 ng of total RNA were 5.7 × 10(4) in PC12 (rat neuronal cell), 1.3 × 10(4) in Caco-2 (human intestinal cell), 0.67 × 10(4) in TF-1 (human erythropoietic precursor), 133.3 in SH-SY5Y (human neuronal cell), and 56.7 in human umbilical vein endothelial cells (human endothelial cells). The copies of AChEH in these cell types were 0.3 × 10(4), 3.3 × 10(4), 2.7 × 10(4), 133.3, and 46.7, respectively, and AChER were 0.07 × 10(4), 0.13 × 10(4), 890, 3.3, and 2.7, respectively. Furthermore, PC12 and TF-1 cells were chosen for the analysis of AChE splicing pattern during differentiation. The results demonstrated a selective increase in AChET mRNA but not AChER or AChEH mRNAs in PC12 upon nerve growth factor-induced neuronal differentiation. PC12 cells could therefore act as a good cell model for the study on alternative splicing mechanism and regulation of AChET.
Collapse
Affiliation(s)
- Cathy W C Bi
- Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Tsim K, Soreq H. Acetylcholinesterase: old questions and new developments. Front Mol Neurosci 2013; 5:101. [PMID: 23316131 PMCID: PMC3540815 DOI: 10.3389/fnmol.2012.00101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 12/14/2012] [Indexed: 11/20/2022] Open
Affiliation(s)
- Karl Tsim
- Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology Hong Kong, China
| | | |
Collapse
|
19
|
Luk WKW, Chen VP, Choi RCY, Tsim KWK. N-linked glycosylation of dimeric acetylcholinesterase in erythrocytes is essential for enzyme maturation and membrane targeting. FEBS J 2012; 279:3229-39. [PMID: 22805525 DOI: 10.1111/j.1742-4658.2012.08708.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acetylcholinesterase (AChE) is well-known for its cholinergic functions in the nervous system; however, this enzyme is also found in other tissues where its function is still not understood. AChE is synthesized through alternative splicing as splicing variants, with isoforms including read-through (AChE(R)), tailed (AChE(T)) and hydrophobic (AChE(H)). In human erythrocytes, AChE(H) is a glycophosphatidylinositol-linked dimer on the plasma membrane. Three N-linked glycosylation sites have been identified in the catalytic domain of human AChE. Here, we investigate the roles of glycosylation in assembly and trafficking of human AChE(H). In transfected fibroblasts, expression of AChE(H) was able to mimic the function of the dimeric form of AChE on the erythrocyte membrane. A glycan-depleted form was constructed by site-directed mutagenesis. By comparison with the wild-type AChE(H), the mutant had a much lower enzymatic activity and a much higher K(m) value. In addition, the mutant was dimerized in the endoplasmic reticulum, but was not trafficked to the Golgi apparatus. The results suggest that the glycosylation may affect AChE(H) enzymatic activity and trafficking, but not dimer formation. The present findings indicate the significance of N-glycosylation in controlling the biosynthesis of the AChE(H) dimer form.
Collapse
Affiliation(s)
- Wilson K W Luk
- Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China
| | | | | | | |
Collapse
|
20
|
Vidal CJ, Montenegro MF, Muñoz-Delgado E, Campoy FJ, Cabezas-Herrera J, Moral-Naranjo MT. The AChE membrane-binding tail PRiMA is down-regulated in muscle and nerve of mice with muscular dystrophy by merosin deficiency. Chem Biol Interact 2012; 203:330-4. [PMID: 22906800 DOI: 10.1016/j.cbi.2012.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/27/2012] [Accepted: 08/02/2012] [Indexed: 01/22/2023]
Abstract
Since Duchenne muscular dystrophy was attributed to mutations in the dystrophin gene, more than 30 genes have been found to be causally related with muscular dystrophies, about half of them encoding proteins of the dystrophin-glycoprotein complex (DGC). Through laminin-2, the DGC bridges the muscle cytoskeleton and the extracellular matrix. Decreased levels of PRiMA-linked acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) have been observed in dystrophic muscle and nerve of dystrophin-deficient (mdx) and laminin-2 deficient (Lama2dy) mice. To help explain these observations, the relative content of AChE, BuChE and PRiMA mRNAs were compared in normal and Lama2dy mouse muscle and sciatic nerve. The 17-fold lower level of PRiMA mRNA in Lama2dy muscle explained the deficit in PRiMA-linked ChEs. This would increase acetylcholine availability and, eventually, the desensitization of nicotinic receptors. Abnormal development of the Schwann cells led to peripheral neuropathy in the Lama2dy mouse. Compared with normal nerve, dystrophic nerve displayed 4-fold less AChE-T mRNA, 3-fold more BuChE mRNA and 2.5-fold less PRiMA mRNA, which agreed with the lower AChE activity in dystrophic nerve, its increased BuChE activity and the specific drop in PRiMA-linked BuChE. The widely accepted role of glial cells as the source of BuChE, the observed dysmyelination of Lama2dy nerve and its increased BuChE activity support the idea that BuChE up-regulation is related with the aberrant differentiation of the Schwann cells.
Collapse
Affiliation(s)
- C J Vidal
- Departamento de Bioquímica y Biología Molecular-A, Edificio de Veterinaria, Universidad de Murcia, Regional Campus of International Excellence Campus Mare Nostrum, E-30071 Espinardo, Murcia, Spain.
| | | | | | | | | | | |
Collapse
|
21
|
Sperling LE, Klaczinski J, Schütz C, Rudolph L, Layer PG. Mouse acetylcholinesterase enhances neurite outgrowth of rat R28 cells through interaction with laminin-1. PLoS One 2012; 7:e36683. [PMID: 22570738 PMCID: PMC3343015 DOI: 10.1371/journal.pone.0036683] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 04/11/2012] [Indexed: 02/02/2023] Open
Abstract
The enzyme acetylcholinesterase (AChE) terminates synaptic transmission at cholinergic synapses by hydrolyzing the neurotransmitter acetylcholine, but can also exert 'non-classical', morpho-regulatory effects on developing neurons such as stimulation of neurite outgrowth. Here, we investigated the role of AChE binding to laminin-1 on the regulation of neurite outgrowth by using cell culture, immunocytochemistry, and molecular biological approaches. To explore the role of AChE, we examined fiber growth of cells overexpressing different forms of AChE, and/or during their growth on laminin-1. A significant increase of neuritic growth as compared with controls was observed for neurons over-expressing AChE. Accordingly, addition of globular AChE to the medium increased total length of neurites. Co-transfection with PRIMA, a membrane anchor of AChE, led to an increase in fiber length similar to AChE overexpressing cells. Transfection with an AChE mutant that leads to the retention of AChE within cells had no stimulatory effect on neurite length. Noticeably, the longest neurites were produced by neurons overexpressing AChE and growing on laminin-1, suggesting that the AChE/laminin interaction is involved in regulating neurite outgrowth. Our findings demonstrate that binding of AChE to laminin-1 alters AChE activity and leads to increased neurite growth in culture. A possible mechanism of the AChE effect on neurite outgrowth is proposed due to the interaction of AChE with laminin-1.
Collapse
Affiliation(s)
- Laura E Sperling
- Entwicklungsbiologie und Neurogenetik, Fachbereich Biologie, Technische Universität Darmstadt, Darmstadt, Germany.
| | | | | | | | | |
Collapse
|