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Jiang S, Yuan C, Zou T, Koh J, Basabrain M, Chen Q, Liu J, Heng BC, Lim LW, Wang P, Zhang C. An injectable hydrogel loaded with GMSCs-derived neural lineage cells promotes recovery after stroke. Tissue Eng Part A 2024. [PMID: 38756085 DOI: 10.1089/ten.tea.2023.0330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024] Open
Abstract
Ischemic stroke is a devastating medical condition with poor prognosis due to the lack of effective treatment modalities. Transplantation of human neural stem cells or primary neural cells is a promising treatment approach, but this is hindered by limited suitable cell sources and low in vitro expansion capacity. This study aimed i) to use small molecules to reprogram gingival mesenchymal stem cells (GMSCs) commitment to the neural lineage cells in vitro, and ii) to use hyaluronic acid (HA) hydrogel scaffolds seeded with GMSCs-derived neural lineage cells to treat ischemic stroke invivo. Neural induction was carried out with a small molecule cocktail-based one-step culture protocol over a period of 24 hours. The induced cells were analyzed for expression of neural markers with immunocytochemistry and qRT-PCR. The SD rats (n=100) were subjected to the middle cerebral artery occlusion (MCAO) reperfusion ischemic stroke model. Then, after 8 days post-MCAO, the modelled rats were randomly assigned to six study groups (n=12 per group): (i) GMSCs, (ii) GMSCs-derived neural lineage cells, (iii) HA and GMSCs-derived neural lineage cells, (iv) HA, (v) PBS, and (vi) sham transplantation control, and received their respective transplantation. Evaluation of post-stroke recovery were performed by the behavioral tests and histological assessments. The morphologically altered nature of neural lineages has been observed of the GMSCs treated with small molecules compared to the untreated controls. As shown by the qRT-PCR and immunocytochemistry, small molecules further signifcantly enhanced the experession level of neural markers of GMSCs as compared with the untreated controls (all p<0.05). Intracerebral injection of self-assembling HA hydrogel carrying GMSCs-derived neural lineage cells promoted the recovery of neural function and reduced ischemic damage in rats with ischemic stroke, as demonstrated by histological examination and behavioral assessments (all p<0.05). In conclusion, the small molecule cocktail significantly enhanced the differentiation of GMSCs into neural lineage cells. The HA hydrogel was found to facilitate the proliferation and differentiation of GMSCs-derived neural lineage cells. Furthermore, HA hydrogel seeded with GMSCs-derived neural lineage cells could promote tissue repair and functional recovery in rats with ischemic stroke and may be a promising alternative treatment modality for stroke.
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Affiliation(s)
- Shan Jiang
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
- Shenzhen Stomatology Hospital (Pingshan), Southern Medical University, Shenzhen, China;
| | - Changyong Yuan
- The Affiliated Stomatological Hospital of Xuzhou Medical University, Xuzhou, China;
| | - Ting Zou
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
- Shenzhen Stomatology Hospital (Pingshan), Southern Medical University, Shenzhen, China;
| | - Junhao Koh
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China;
| | - Mohammed Basabrain
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China;
| | - Qixin Chen
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China;
| | - Junqing Liu
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China;
| | - Boon Chin Heng
- Peking University School of Stomatology, Beijing, China;
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong;
| | - Penglai Wang
- Xuzhou Stomatological Hospital, Dental Implant Cente, Xuzhou, Jiangsu, China;
| | - Chengfei Zhang
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong;
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Chin AHB, Lim LW, Muhsin SM. Regulatory safeguards needed if preimplantation genetic testing for polygenic risk scores (PGT-P) is permitted in Singapore. J Med Ethics 2024:jme-2023-109195. [PMID: 38744454 DOI: 10.1136/jme-2023-109195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 03/23/2024] [Indexed: 05/16/2024]
Abstract
Singapore, a highly affluent island city-state located in Southeast Asia, has increasingly leveraged new assisted reproductive technologies (ART) to overcome its dismal fertility rates in recent years. A new frontier in ART is preimplantation genetic testing (PGT) for polygenic risk scores (PRS) to predict complex multifactorial traits in IVF (in vitro fertilisation) embryos, such as type 2 diabetes, cardiovascular diseases and various other characteristics like height, intelligence quotient (IQ), hair and eye colour. Unlike well-known safety risks with human genome editing, there are negligible risks with PGT-P, because there are no man-made genetic modifications that can be transmitted to future generations. Nevertheless, the current efficacy of using PGT-P to select IVF embryos for either increased or decreased probability of developing specific polygenic traits is still far from certain. Hence, the regulatory safeguards proposed here will be based on the assumption that the efficacy of this new technology platform has already been validated. These include: (1) restricting the application of PGT-P only for prevention of clinically relevant polygenic disease traits, (2) securely blocking patients' access to the raw genomic DNA sequencing data of their IVF embryos, (3) validating diagnosis of polygenic disease traits in the prospective parents/grandparents of IVF embryos, and restricting PGT-P only for preventing specifically diagnosed polygenic disease traits and (4) mandating rigorous and comprehensive genetic counselling for IVF patients considering PGT-P. There is an urgent and dire need to prevent abuse of the PGT-P technique, as well as protect the interests and welfare of patients if its clinical application is to be permitted in the country.
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Affiliation(s)
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong Special Administrative Region, People's Republic of China
| | - Sayyed Mohamed Muhsin
- Department of Fiqh and Usul al-Fiqh, International Islamic University Malaysia, Gombak, Kuala Lumpur, Malaysia
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Buck O, Found T, Weldon R, Lim LW, Aquili L. Dietary tyrosine consumption modulates the effects of tDCS, but not tRNS, on planning behaviour. Brain Stimul 2024; 17:572-574. [PMID: 38648971 DOI: 10.1016/j.brs.2024.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 04/25/2024] Open
Affiliation(s)
- Oliver Buck
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Tenielle Found
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Rachel Weldon
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region
| | - Luca Aquili
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia; School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region.
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Caudwell KM, Baldini S, Calvezzi G, Graham A, Jackson K, Johansson I, Sines M, Lim LW, Aquili L. Learning bias predicts fear acquisition under stress but not cognitive flexibility. Physiol Behav 2023; 272:114384. [PMID: 37866645 DOI: 10.1016/j.physbeh.2023.114384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 10/24/2023]
Abstract
Individuals differ in their ability to learn from reinforcement and in avoiding punishment, which can be measured by the Probabilistic Selection Task (PST). Recently, some studies have demonstrated that this learning bias is regulated by the dopaminergic system, and that stress can differentially affect the use of positive (i.e., reinforcement) and negative (i.e., avoiding punishment) feedback. The current two studies examined whether performance on the PST can predict measures of goal-directed behaviour as assessed by a cognitive flexibility task (Wisconsin Card Sorting Test) and the acquisition of fear responses, when individuals are exposed to a stressor (Socially Evaluated Cold Pressor Test). A total of 26 and 59 healthy participants completed Experiments I and II, respectively. In those who were best at learning from reinforcement, stress increased the processing (i.e., higher skin conductance responses) of non-threatening stimuli during fear acquisition compared to the non-stressful condition, which was not recapitulated in those who were best at avoiding punishment. Additionally, PST performance did not interact with stress to modulate cognitive flexibility, although stress negatively impaired this domain, consistent with previous findings. Furthermore, independent of stress, both positive and negative learning biases were correlated with cognitive flexibility errors. Our results demonstrate that the PST has predictive value for better understanding the determinants of reinforcement and avoidance learning.
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Affiliation(s)
- Kim M Caudwell
- Faculty of Health, Charles Darwin University, Darwin, Australia
| | - Sara Baldini
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Gemma Calvezzi
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Aidan Graham
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Kasie Jackson
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Isabella Johansson
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia
| | - Madeline Sines
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region of China
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region of China
| | - Luca Aquili
- College of Health and Education, School of Psychology, Murdoch University, Perth, Australia; School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region of China.
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Strekalova T, Moskvin O, Jain AY, Gorbunov N, Gorlova A, Sadovnik D, Umriukhin A, Cespuglio R, Yu WS, Tse ACK, Kalueff AV, Lesch KP, Lim LW. Molecular signature of excessive female aggression: study of stressed mice with genetic inactivation of neuronal serotonin synthesis. J Neural Transm (Vienna) 2023; 130:1113-1132. [PMID: 37542675 PMCID: PMC10460733 DOI: 10.1007/s00702-023-02677-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 07/21/2023] [Indexed: 08/07/2023]
Abstract
Aggression is a complex social behavior, critically involving brain serotonin (5-HT) function. The neurobiology of female aggression remains elusive, while the incidence of its manifestations has been increasing. Yet, animal models of female aggression are scarce. We previously proposed a paradigm of female aggression in the context of gene x environment interaction where mice with partial genetic inactivation of tryptophan hydroxylase-2 (Tph2+/- mice), a key enzyme of neuronal 5-HT synthesis, are subjected to predation stress resulting in pathological aggression. Using deep sequencing and the EBSeq method, we studied the transcriptomic signature of excessive aggression in the prefrontal cortex of female Tph2+/- mice subjected to rat exposure stress and food deprivation. Challenged mutants, but not other groups, displayed marked aggressive behaviors. We found 26 genes with altered expression in the opposite direction between stressed groups of both Tph2 genotypes. We identified several molecular markers, including Dgkh, Arfgef3, Kcnh7, Grin2a, Tenm1 and Epha6, implicated in neurodevelopmental deficits and psychiatric conditions featuring impaired cognition and emotional dysregulation. Moreover, while 17 regulons, including several relevant to neural plasticity and function, were significantly altered in stressed mutants, no alteration in regulons was detected in stressed wildtype mice. An interplay of the uncovered pathways likely mediates partial Tph2 inactivation in interaction with severe stress experience, thus resulting in excessive female aggression.
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Affiliation(s)
- Tatyana Strekalova
- Division of Molecular Psychiatry, Center of Mental Health, University Hospital of Würzburg, Würzburg, Germany
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Oleg Moskvin
- Primate Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Singapore Medical School, BluMaiden Biosciences, Singapore, Singapore
| | - Aayushi Y Jain
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Nikita Gorbunov
- Division of Molecular Psychiatry, Center of Mental Health, University Hospital of Würzburg, Würzburg, Germany
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Anna Gorlova
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov Moscow State Medical University, Moscow, Russia
| | - Daria Sadovnik
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov Moscow State Medical University, Moscow, Russia
| | - Aleksei Umriukhin
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov Moscow State Medical University, Moscow, Russia
| | - Raymond Cespuglio
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov Moscow State Medical University, Moscow, Russia
- Neuroscience Research Center of Lyon, Beliv Plateau, Claude-Bernard Lyon-1 University, Bron, France
| | - Wing Shan Yu
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Anna Chung Kwan Tse
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Allan V Kalueff
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia
| | - Klaus-Peter Lesch
- Division of Molecular Psychiatry, Center of Mental Health, University Hospital of Würzburg, Würzburg, Germany.
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China.
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Khairuddin S, Lim WL, Aquili L, Tsui KC, Tse ACK, Jayalath S, Varma R, Sharp T, Benazzouz A, Steinbusch H, Blokland A, Temel Y, Lim LW. Prelimbic Cortical Stimulation Induces Antidepressant-like Responses through Dopaminergic-Dependent and -Independent Mechanisms. Cells 2023; 12:1449. [PMID: 37296570 PMCID: PMC10253143 DOI: 10.3390/cells12111449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/16/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
High-frequency stimulation (HFS) is a promising therapy for patients with depression. However, the mechanisms underlying the HFS-induced antidepressant-like effects on susceptibility and resilience to depressive-like behaviors remain obscure. Given that dopaminergic neurotransmission has been found to be disrupted in depression, we investigated the dopamine(DA)-dependent mechanism of the antidepressant-like effects of HFS of the prelimbic cortex (HFS PrL). We performed HFS PrL in a rat model of mild chronic unpredictable stress (CUS) together with 6-hydroxydopamine lesioning in the dorsal raphe nucleus (DRN) and ventral tegmental area (VTA). Animals were assessed for anxiety, anhedonia, and behavioral despair. We also examined levels of corticosterone, hippocampal neurotransmitters, neuroplasticity-related proteins, and morphological changes in dopaminergic neurons. We found 54.3% of CUS animals exhibited decreased sucrose consumption and were designated as CUS-susceptible, while the others were designated CUS-resilient. HFS PrL in both the CUS-susceptible and CUS-resilient animals significantly increased hedonia, reduced anxiety, decreased forced swim immobility, enhanced hippocampal DA and serotonin levels, and reduced corticosterone levels when compared with the respective sham groups. The hedonic-like effects were abolished in both DRN- and VTA-lesioned groups, suggesting the effects of HFS PrL are DA-dependent. Interestingly, VTA-lesioned sham animals had increased anxiety and forced swim immobility, which was reversed by HFS PrL. The VTA-lesioned HFS PrL animals also had elevated DA levels, and reduced p-p38 MAPK and NF-κB levels when compared to VTA-lesioned sham animals. These findings suggest that HFS PrL in stressed animals leads to profound antidepressant-like responses possibly through both DA-dependent and -independent mechanisms.
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Affiliation(s)
- Sharafuddin Khairuddin
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Wei Ling Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Department of Biological Sciences, Sunway University, Bandar Sunway, Petaling Jaya 47500, Malaysia
| | - Luca Aquili
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Discipline of Psychology, College of Health and Education, Murdoch University, Perth 6150, Australia
| | - Ka Chun Tsui
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Anna Chung-Kwan Tse
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Shehani Jayalath
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ruhani Varma
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Abdelhamid Benazzouz
- CNRS UMR5293, Institute of Neurodegenerative Diseases, University de Bordeaux, 33000 Bordeaux, France
| | - Harry Steinbusch
- Department of Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Yasin Temel
- Department of Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
- Department of Neurosurgery, Maastricht University, 6229 HX Maastricht, The Netherlands
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Department of Biological Sciences, Sunway University, Bandar Sunway, Petaling Jaya 47500, Malaysia
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Wong KH, Lim LW, Mohd Hisam NS, Kamarudin MNA, Lakshmanan H. Editorial: Natural products for neuroprotection and neuroregeneration. Front Pharmacol 2023; 14:1209297. [PMID: 37266142 PMCID: PMC10230221 DOI: 10.3389/fphar.2023.1209297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 05/09/2023] [Indexed: 06/03/2023] Open
Affiliation(s)
- Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | | | | | - Hariprasath Lakshmanan
- Division of Biochemistry, School of Life Sciences, JSS Academy of Higher Education and Research, Mysuru, Karnataka, India
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Lew SY, Mohd Hisam NS, Phang MWL, Syed Abdul Rahman SN, Poh RYY, Lim SH, Kamaruzzaman MA, Chau SC, Tsui KC, Lim LW, Wong KH. Adenosine Improves Mitochondrial Function and Biogenesis in Friedreich's Ataxia Fibroblasts Following L-Buthionine Sulfoximine-Induced Oxidative Stress. Biology (Basel) 2023; 12:biology12040559. [PMID: 37106759 PMCID: PMC10136261 DOI: 10.3390/biology12040559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/25/2023] [Accepted: 03/30/2023] [Indexed: 04/29/2023]
Abstract
Adenosine is a nucleoside that is widely distributed in the central nervous system and acts as a central excitatory and inhibitory neurotransmitter in the brain. The protective role of adenosine in different pathological conditions and neurodegenerative diseases is mainly mediated by adenosine receptors. However, its potential role in mitigating the deleterious effects of oxidative stress in Friedreich's ataxia (FRDA) remains poorly understood. We aimed to investigate the protective effects of adenosine against mitochondrial dysfunction and impaired mitochondrial biogenesis in L-buthionine sulfoximine (BSO)-induced oxidative stress in dermal fibroblasts derived from an FRDA patient. The FRDA fibroblasts were pre-treated with adenosine for 2 h, followed by 12.50 mM BSO to induce oxidative stress. Cells in medium without any treatments or pre-treated with 5 µM idebenone served as the negative and positive controls, respectively. Cell viability, mitochondrial membrane potential (MMP), aconitase activity, adenosine triphosphate (ATP) level, mitochondrial biogenesis, and associated gene expressions were assessed. We observed disruption of mitochondrial function and biogenesis and alteration in gene expression patterns in BSO-treated FRDA fibroblasts. Pre-treatment with adenosine ranging from 0-600 µM restored MMP, promoted ATP production and mitochondrial biogenesis, and modulated the expression of key metabolic genes, namely nuclear respiratory factor 1 (NRF1), transcription factor A, mitochondrial (TFAM), and NFE2-like bZIP transcription factor 2 (NFE2L2). Our study demonstrated that adenosine targeted mitochondrial defects in FRDA, contributing to improved mitochondrial function and biogenesis, leading to cellular iron homeostasis. Therefore, we suggest a possible therapeutic role for adenosine in FRDA.
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Affiliation(s)
- Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | | | - Michael Weng Lok Phang
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | | | - Rozaida Yuen Ying Poh
- Department of Biomedical Science, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Siew Huah Lim
- Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Mohd Amir Kamaruzzaman
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Cheras, Kuala Lumpur 56000, Malaysia
| | - Sze Chun Chau
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Ka Chun Tsui
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Chau SC, Chong PS, Jin H, Tsui KC, Khairuddin S, Tse ACK, Lew SY, Tipoe GL, Lee CW, Fung ML, Wong KH, Lim LW. Hericium erinaceus Promotes Anti-Inflammatory Effects and Regulation of Metabolites in an Animal Model of Cerebellar Ataxia. Int J Mol Sci 2023; 24:ijms24076089. [PMID: 37047062 PMCID: PMC10094689 DOI: 10.3390/ijms24076089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 04/14/2023] Open
Abstract
Cerebellar ataxia is a neurodegenerative disorder with no definitive treatment. Although previous study demonstrated the neuroprotective effects of Hericium erinaceus (H.E.), the mechanisms of H.E. treatment on the neuroinflammatory response, neurotransmission, and related metabolites remain largely unknown. We demonstrated that 3-AP rats treated with 25 mg/kg H.E. extracts had improved motor coordination and balance in the accelerated rotarod and rod tests. We showed that the H.E. treatment upregulated the expression of Tgfb1, Tgfb2, and Smad3 genes to levels comparable to those in the non-3-AP control group. Interestingly, we also observed a significant correlation between Tgfb2 gene expression and rod test performance in the 3-AP saline group, but not in the non-3-AP control or H.E.+3-AP groups, indicating a relationship between Tgfb2 gene expression and motor balance in the 3-AP rat model. Additionally, we also found that the H.E. treatment increased mitochondrial COX-IV protein expression and normalized dopamine-serotonin neurotransmission and metabolite levels in the cerebellum of the H.E.+3-AP group compared to the 3-AP saline group. In conclusion, our findings suggest that the H.E. treatment improved motor function in the 3-AP rat model, which was potentially mediated through neuroprotective mechanisms involving TGFB2-Smad3 signaling via normalization of neurotransmission and metabolic pathways.
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Affiliation(s)
- Sze Chun Chau
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Pit Shan Chong
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Hongkai Jin
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Ka Chun Tsui
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Sharafuddin Khairuddin
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Anna Chung Kwan Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Sze Yuen Lew
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - George Lim Tipoe
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Chi Wai Lee
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Man-Lung Fung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kah Hui Wong
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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Li S, Poon CH, Zhang Z, Yue M, Chen R, Zhang Y, Hossain MF, Pan Y, Zhao J, Rong L, Chu LW, Shea YF, Rogaeva E, Tu J, St George-Hyslop P, Lim LW, Song YQ. MicroRNA-128 suppresses tau phosphorylation and reduces amyloid-beta accumulation by inhibiting the expression of GSK3β, APPBP2, and mTOR in Alzheimer's disease. CNS Neurosci Ther 2023. [PMID: 36880288 DOI: 10.1111/cns.14143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 02/10/2023] [Accepted: 02/16/2023] [Indexed: 03/08/2023] Open
Abstract
INTRODUCTION AND AIMS Alzheimer's disease (AD) is characterized by the abnormal accumulation of hyperphosphorylated tau proteins and amyloid-beta (Aβ) peptides. Recent studies have shown that many microRNAs (miRNAs) are dysregulated in AD, and modulation of these miRNAs can influence the development of tau and Aβ pathology. The brain-specific miRNA miR-128, encoded by MIR128-1 and MIR128-2, is important for brain development and dysregulated in AD. In this study, the role of miR-128 in tau and Aβ pathology as well as the regulatory mechanism underlying its dysregulation were investigated. METHODS The effect of miR-128 on tau phosphorylation and Aβ accumulation was examined in AD cellular models through miR-128 overexpression and inhibition. The therapeutic potential of miR-128 in AD mouse model was assessed by comparing phenotypes of 5XFAD mice administered with miR-128-expressing AAVs with 5XFAD mice administered with control AAVs. Phenotypes examined included behavior, plaque load, and protein expression. The regulatory factor of miR-128 transcription was identified through luciferase reporter assay and validated by siRNA knockdown and ChIP analysis. RESULTS Both gain-of-function and loss-of-function studies in AD cellular models reveal that miR-128 represses tau phosphorylation and Aβ secretion. Subsequent investigations show that miR-128 directly inhibits the expression of tau phosphorylation kinase GSK3β and Aβ modulators APPBP2 and mTOR. Upregulation of miR-128 in the hippocampus of 5XFAD mice ameliorates learning and memory impairments, decreases plaque deposition, and enhances autophagic flux. We further demonstrated that C/EBPα transactivates MIR128-1 transcription, while both C/EBPα and miR-128 expression are inhibited by Aβ. CONCLUSION Our findings suggest that miR-128 suppresses AD pathogenesis, and could be a promising therapeutic target for AD. We also find a possible mechanism underlying the dysregulation of miR-128 in AD, in which Aβ reduces miR-128 expression by inhibiting C/EBPα.
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Affiliation(s)
- Siwen Li
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Chi Him Poon
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Zhigang Zhang
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China.,The Brain Cognition and Brain Disease Institute (BCBDI), CAS Key Laboratory of Brain Connectome and Manipulation, Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Ming Yue
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Ruijun Chen
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Yalun Zhang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Md Farhad Hossain
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Yining Pan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Jun Zhao
- Department of Clinical Immunology, Third Hospital of Sun Yat-sen University, Guangzhou, China
| | - Lei Rong
- Department of Medicine, The University of Hongkong-Shenzhen Hospital, Shenzhen, China
| | - Leung Wing Chu
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - Yat Fung Shea
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - Ekaterina Rogaeva
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Jie Tu
- The Brain Cognition and Brain Disease Institute (BCBDI), CAS Key Laboratory of Brain Connectome and Manipulation, Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China
| | - Peter St George-Hyslop
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Lee Wei Lim
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - You-Qiang Song
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China.,The Brain Cognition and Brain Disease Institute (BCBDI), CAS Key Laboratory of Brain Connectome and Manipulation, Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, China.,Department of Medicine, The University of Hongkong-Shenzhen Hospital, Shenzhen, China.,The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
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Poon CH, Wong STN, Roy J, Wang Y, Chan HWH, Steinbusch H, Blokland A, Temel Y, Aquili L, Lim LW. Sex Differences between Neuronal Loss and the Early Onset of Amyloid Deposits and Behavioral Consequences in 5xFAD Transgenic Mouse as a Model for Alzheimer's Disease. Cells 2023; 12:cells12050780. [PMID: 36899916 PMCID: PMC10000751 DOI: 10.3390/cells12050780] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/19/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
A promising direction in the research on Alzheimer's Disease (AD) is the identification of biomarkers that better inform the disease progression of AD. However, the performance of amyloid-based biomarkers in predicting cognitive performance has been shown to be suboptimal. We hypothesise that neuronal loss could better inform cognitive impairment. We have utilised the 5xFAD transgenic mouse model that displays AD pathology at an early phase, already fully manifested after 6 months. We have evaluated the relationships between cognitive impairment, amyloid deposition, and neuronal loss in the hippocampus in both male and female mice. We observed the onset of disease characterized by the emergence of cognitive impairment in 6-month-old 5xFAD mice coinciding with the emergence of neuronal loss in the subiculum, but not amyloid pathology. We also showed that female mice exhibited significantly increased amyloid deposition in the hippocampus and entorhinal cortex, highlighting sex-related differences in the amyloid pathology of this model. Therefore, parameters based on neuronal loss might more accurately reflect disease onset and progression compared to amyloid-based biomarkers in AD patients. Moreover, sex-related differences should be considered in studies involving 5xFAD mouse models.
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Affiliation(s)
- Chi Him Poon
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - San Tung Nicholas Wong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Jaydeep Roy
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yingyi Wang
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Hui Wang Hujo Chan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Harry Steinbusch
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6211 LK Maastricht, The Netherlands
- Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6211 LK Maastricht, The Netherlands
| | - Yasin Temel
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6211 LK Maastricht, The Netherlands
- Department of Neurosurgery, Maastricht University Medical Centre, Maastricht University, 6211 LK Maastricht, The Netherlands
| | - Luca Aquili
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
- College of Health and Education, Discipline of Psychology, Murdoch University, Perth 6150, Australia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
- Correspondence:
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12
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Poon CH, Liu Y, Pak S, Zhao RC, Aquili L, Tipoe GL, Leung GKK, Chan YS, Yang S, Fung ML, Wu EX, Lim LW. Prelimbic Cortical Stimulation with L-methionine Enhances Cognition through Hippocampal DNA Methylation and Neuroplasticity Mechanisms. Aging Dis 2023; 14:112-135. [PMID: 36818556 PMCID: PMC9937711 DOI: 10.14336/ad.2022.0706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 07/06/2022] [Indexed: 11/18/2022] Open
Abstract
Declining global DNA methylation and cognitive impairment are reported to occur in the normal aging process. It is not known if DNA methylation plays a role in the efficacy of memory-enhancing therapies. In this study, aged animals were administered prelimbic cortical deep brain stimulation (PrL DBS) and/or L-methionine (MET) treatment. We found that PrL DBS and MET (MET-PrL DBS) co-administration resulted in hippocampal-dependent spatial memory enhancements in aged animals. Molecular data suggested MET-PrL DBS induced DNA methyltransferase DNMT3a-dependent methylation, robust synergistic upregulation of neuroplasticity-related genes, and simultaneous inhibition of the memory-suppressing gene calcineurin in the hippocampus. We further found that MET-PrL DBS also activated the PKA-CaMKIIα-BDNF pathway, increased hippocampal neurogenesis, and enhanced dopaminergic and serotonergic neurotransmission. We next inhibited the activity of DNA methyltransferase (DNMT) by RG108 infusion in the hippocampus of young animals to establish a causal relationship between DNMT activity and the effects of PrL DBS. Hippocampal DNMT inhibition in young animals was sufficient to recapitulate the behavioral deficits observed in aged animals and abolished the memory-enhancing and molecular effects of PrL DBS. Our findings implicate hippocampal DNMT as a therapeutic target for PrL DBS and pave way for the potential use of non-invasive neuromodulation modalities against dementia.
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Affiliation(s)
- Chi Him Poon
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Yanzhi Liu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Sojeong Pak
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong, China.
| | | | - Luca Aquili
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,College of Science, Health, Engineering and Education, Discipline of Psychology, Murdoch University, Perth, Australia.
| | - George Lim Tipoe
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Gilberto Ka-Kit Leung
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Sungchil Yang
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong, China.
| | - Man-Lung Fung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Ed Xuekui Wu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China.
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,Correspondence should be addressed to: Dr. Lee Wei LIM, Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China. .
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Agadagba SK, Lim LW, Chan LLH. Advances in transcorneal electrical stimulation: From the eye to the brain. Front Cell Neurosci 2023; 17:1134857. [PMID: 36937185 PMCID: PMC10019785 DOI: 10.3389/fncel.2023.1134857] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 02/07/2023] [Indexed: 03/06/2023] Open
Abstract
The mammalian brain is reported to contain about 106-109 neurons linked together to form complex networks. Physiologically, the neuronal networks interact in a rhythmic oscillatory pattern to coordinate the brain's functions. Neuromodulation covers a broad range of techniques that can alter neuronal network activity through the targeted delivery of electrical or chemical stimuli. Neuromodulation can be used to potentially treat medical conditions and can serve as a research tool for studying neural functions. Typically, the main method of neuromodulation is to electrically stimulate specific structures in both the central and peripheral nervous systems via surgically implanted electrodes. Therefore, it is imperative to explore novel and safer methods for altering neuronal network activity. Transcorneal electrical stimulation (TES) has rapidly emerged as a non-invasive neuromodulatory technique that can exert beneficial effects on the brain through the eyes. There is substantial evidence to show that TES can change the brain oscillations in rodents. Moreover, the molecular data clearly shows that TES can also activate non-visual brain regions. In this review, we first summarize the use of TES in the retina and then discuss its effects in the brain through the eye-brain connection. We then comprehensively review the substantial evidence from electrophysiological, behavioral, and molecular studies on the role of TES on modulating neurons in the brain. Lastly, we discuss the implications and possible future directions of the research on TES as a non-invasive tool for neuromodulation of the brain via directly stimulating the mammalian eye.
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Affiliation(s)
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Leanne Lai Hang Chan
- Department of Electrical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
- *Correspondence: Leanne Lai Hang Chan
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14
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Subermaniam K, Lew SY, Yow YY, Lim SH, Yu WS, Lim LW, Wong KH. Malaysian brown macroalga Padina australis mitigates lipopolysaccharide-stimulated neuroinflammation in BV2 microglial cells. Iran J Basic Med Sci 2023; 26:669-679. [PMID: 37275754 PMCID: PMC10237163 DOI: 10.22038/ijbms.2023.67835.14842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 03/06/2023] [Indexed: 06/07/2023]
Abstract
Objectives Neuroinflammation and microglial activation are pathological features in central nervous system disorders. Excess levels of reactive oxygen species (ROS) and pro-inflammatory cytokines have been implicated in exacerbation of neuronal damage during chronic activation of microglial cells. Padina australis, a brown macroalga, has been demonstrated to have various pharmacological properties such as anti-neuroinflammatory activity. However, the underlying mechanism mediating the anti-neuroinflammatory potential of P. australis remains poorly understood. We explored the use of Malaysian P. australis in attenuating lipopolysaccharide (LPS)-stimulated neuroinflammation in BV2 microglial cells. Materials and Methods Fresh specimens of P. australis were freeze-dried and subjected to ethanol extraction. The ethanol extract (PAEE) was evaluated for its protective effects against 1 µg/ml LPS-stimulated neuroinflammation in BV2 microglial cells. Results LPS reduced the viability of BV2 microglia cells and increased the levels of nitric oxide (NO), prostaglandin E2 (PGE2), intracellular reactive oxygen species (ROS), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). However, the neuroinflammatory response was reversed by 0.5-2.0 mg/ml PAEE in a dose-dependent manner. Analysis of liquid chromatography-mass spectrometry (LC-MS) of PAEE subfractions revealed five compounds; methyl α-eleostearate, ethyl α-eleostearate, niacinamide, stearamide, and linoleic acid. Conclusion The protective effects of PAEE against LPS-stimulated neuroinflammation in BV2 microglial cells were found to be mediated by the suppression of excess levels of intracellular ROS and pro-inflammatory mediators and cytokines, denoting the protective role of P. australis in combating continuous neuroinflammation. Our findings support the use of P. australis as a possible therapeutic for neuroinflammatory and neurodegenerative diseases.
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Affiliation(s)
- Kogilavani Subermaniam
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
- Sungai Buloh Training Institute of Ministry of Health Malaysia, Jalan Hospital, 47000 Sungai Buloh, Selangor, Malaysia
| | - Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Yoon Yen Yow
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Siew Huah Lim
- Department of Chemistry, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Wing Shan Yu
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
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15
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Yatan G, Lim LW, Aquili L. Routine behaviour, a putative dopamine marker, predicts cognitive flexibility by tDCS of the dlPFC. Brain Stimul 2023; 16:108-110. [PMID: 36731769 DOI: 10.1016/j.brs.2023.01.1676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/03/2023] Open
Affiliation(s)
- Gibson Yatan
- College of Science, Health, Engineering and Education, Discipline of Psychology, Murdoch University, Perth, Australia
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China
| | - Luca Aquili
- College of Science, Health, Engineering and Education, Discipline of Psychology, Murdoch University, Perth, Australia; School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China.
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16
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Heng BC, Bai Y, Li X, Lim LW, Li W, Ge Z, Zhang X, Deng X. Electroactive Biomaterials for Facilitating Bone Defect Repair under Pathological Conditions. Adv Sci (Weinh) 2023; 10:e2204502. [PMID: 36453574 PMCID: PMC9839869 DOI: 10.1002/advs.202204502] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 10/24/2022] [Indexed: 06/02/2023]
Abstract
Bone degeneration associated with various diseases is increasing due to rapid aging, sedentary lifestyles, and unhealthy diets. Living bone tissue has bioelectric properties critical to bone remodeling, and bone degeneration under various pathological conditions results in significant changes to these bioelectric properties. There is growing interest in utilizing biomimetic electroactive biomaterials that recapitulate the natural electrophysiological microenvironment of healthy bone tissue to promote bone repair. This review first summarizes the etiology of degenerative bone conditions associated with various diseases such as type II diabetes, osteoporosis, periodontitis, osteoarthritis, rheumatoid arthritis, osteomyelitis, and metastatic osteolysis. Next, the diverse array of natural and synthetic electroactive biomaterials with therapeutic potential are discussed. Putative mechanistic pathways by which electroactive biomaterials can mitigate bone degeneration are critically examined, including the enhancement of osteogenesis and angiogenesis, suppression of inflammation and osteoclastogenesis, as well as their anti-bacterial effects. Finally, the limited research on utilization of electroactive biomaterials in the treatment of bone degeneration associated with the aforementioned diseases are examined. Previous studies have mostly focused on using electroactive biomaterials to treat bone traumatic injuries. It is hoped that this review will encourage more research efforts on the use of electroactive biomaterials for treating degenerative bone conditions.
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Affiliation(s)
- Boon Chin Heng
- Central LaboratoryPeking University School and Hospital of StomatologyBeijing100081P. R. China
- School of Medical and Life SciencesSunway UniversityDarul EhsanSelangor47500Malaysia
| | - Yunyang Bai
- Department of Geriatric DentistryPeking University School and Hospital of StomatologyBeijing100081P. R. China
| | - Xiaochan Li
- Department of Geriatric DentistryPeking University School and Hospital of StomatologyBeijing100081P. R. China
| | - Lee Wei Lim
- Neuromodulation LaboratorySchool of Biomedical SciencesLi Ka Shing Faculty of MedicineThe University of Hong KongPokfulamHong KongP. R. China
| | - Wang Li
- Department of Biomedical EngineeringPeking UniversityBeijing100871P. R. China
| | - Zigang Ge
- Department of Biomedical EngineeringPeking UniversityBeijing100871P. R. China
| | - Xuehui Zhang
- Department of Dental Materials & Dental Medical Devices Testing CenterPeking University School and Hospital of StomatologyBeijing100081P. R. China
- National Engineering Research Center of Oral Biomaterials and Digital Medical DevicesNMPA Key Laboratory for Dental MaterialsBeijing Laboratory of Biomedical Materials & Beijing Key Laboratory of Digital StomatologyPeking University School and Hospital of StomatologyBeijing100081P. R. China
| | - Xuliang Deng
- Department of Geriatric DentistryPeking University School and Hospital of StomatologyBeijing100081P. R. China
- Department of Dental Materials & Dental Medical Devices Testing CenterPeking University School and Hospital of StomatologyBeijing100081P. R. China
- National Engineering Research Center of Oral Biomaterials and Digital Medical DevicesNMPA Key Laboratory for Dental MaterialsBeijing Laboratory of Biomedical Materials & Beijing Key Laboratory of Digital StomatologyPeking University School and Hospital of StomatologyBeijing100081P. R. China
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Tsui KC, Roy J, Chau SC, Wong KH, Shi L, Poon CH, Wang Y, Strekalova T, Aquili L, Chang RCC, Fung ML, Song YQ, Lim LW. Distribution and inter-regional relationship of amyloid-beta plaque deposition in a 5xFAD mouse model of Alzheimer’s disease. Front Aging Neurosci 2022; 14:964336. [PMID: 35966777 PMCID: PMC9371463 DOI: 10.3389/fnagi.2022.964336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia. Although previous studies have selectively investigated the localization of amyloid-beta (Aβ) deposition in certain brain regions, a comprehensive characterization of the rostro-caudal distribution of Aβ plaques in the brain and their inter-regional correlation remain unexplored. Our results demonstrated remarkable working and spatial memory deficits in 9-month-old 5xFAD mice compared to wildtype mice. High Aβ plaque load was detected in the somatosensory cortex, piriform cortex, thalamus, and dorsal/ventral hippocampus; moderate levels of Aβ plaques were observed in the motor cortex, orbital cortex, visual cortex, and retrosplenial dysgranular cortex; and low levels of Aβ plaques were located in the amygdala, and the cerebellum; but no Aβ plaques were found in the hypothalamus, raphe nuclei, vestibular nucleus, and cuneate nucleus. Interestingly, the deposition of Aβ plaques was positively associated with brain inter-regions including the prefrontal cortex, somatosensory cortex, medial amygdala, thalamus, and the hippocampus. In conclusion, this study provides a comprehensive morphological profile of Aβ deposition in the brain and its inter-regional correlation. This suggests an association between Aβ plaque deposition and specific brain regions in AD pathogenesis.
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Affiliation(s)
- Ka Chun Tsui
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Jaydeep Roy
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Sze Chun Chau
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Kah Hui Wong
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Lei Shi
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Chi Him Poon
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Yingyi Wang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Tatyana Strekalova
- Department of Neuroscience, Maastricht University, Maastricht, Netherlands
- Department of Normal Physiology and Laboratory of Psychiatric Neurobiology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Luca Aquili
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Discipline of Psychology, College of Science, Health, Engineering, and Education, Murdoch University, Perth, WA, Australia
| | - Raymond Chuen-Chung Chang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Man-Lung Fung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- *Correspondence: Man-Lung Fung,
| | - You-qiang Song
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- You-qiang Song,
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Lee Wei Lim,
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Caudwell KM, Soranzo A, Lim LW, Aquili L. How have COVID-19 stringency measures changed scholarly activity? Ann N Y Acad Sci 2022; 1513:5-9. [PMID: 35312197 PMCID: PMC9115337 DOI: 10.1111/nyas.14767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/15/2022] [Indexed: 01/09/2023]
Abstract
Government restrictions to the movement of people due to the COVID-19 pandemic have had a wide range of effects on scientific activity. Here, we show that during the pandemic there has been a reduction in the number of registered non-COVID-19 clinical trials. Furthermore, using the Oxford COVID-19 Government Response Tracker Stringency Index (SI) as an indicator of COVID-19-related workplace adjustment (e.g., restrictions on gatherings, workplace closures, and stay-at-home orders), we demonstrate that this drop in clinical trial registration has been greater in countries with a higher SI. This could have significant consequences for the discovery of treatments that are required to reduce the global burden of disease.
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Affiliation(s)
- Kim M. Caudwell
- College of Health & Human SciencesCharles Darwin UniversityDarwinNorthern TerritoryAustralia
| | - Alessandro Soranzo
- Department of Psychology, Sociology & PoliticsSheffield Hallam UniversitySheffieldUK
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of MedicineUniversity of Hong KongHong KongChina
| | - Luca Aquili
- College of Health & Human SciencesCharles Darwin UniversityDarwinNorthern TerritoryAustralia,Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of MedicineUniversity of Hong KongHong KongChina
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Yu WS, Aquili L, Wong KH, Lo ACY, Chan LLH, Chan YS, Lim LW. Transcorneal electrical stimulation enhances cognitive functions in aged and 5XFAD mouse models. Ann N Y Acad Sci 2022; 1515:249-265. [PMID: 35751874 DOI: 10.1111/nyas.14850] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Dementia is a major burden on global health for which there are no effective treatments. The use of noninvasive visual stimulation to ameliorate cognitive deficits is a novel concept that may be applicable for treating dementia. In this study, we investigated the effects of transcorneal electrical stimulation (TES) on memory enhancement using two mouse models, in aged mice and in the 5XFAD model of Alzheimer's disease. After 3 weeks of TES treatment, mice were subjected to Y-maze and Morris water maze tests to assess hippocampal-dependent learning and memory. Immunostaining of the hippocampus of 5XFAD mice was also performed to examine the effects of TES on amyloid plaque pathology. The results showed that TES improved the performance of both aged and 5XFAD mice in memory tests. TES also reduced hippocampal plaque deposition in male, but not female, 5XFAD mice. Moreover, TES significantly reversed the downregulated level of postsynaptic protein 95 in the hippocampus of male 5XFAD mice, suggesting the effects of TES involve a postsynaptic mechanism. Overall, these findings support further investigation of TES as a potential treatment for cognitive dysfunction and mechanistic studies of TES effects in other dementia models.
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Affiliation(s)
- Wing Shan Yu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Luca Aquili
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,Discipline of Psychology, College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia
| | - Kah Hui Wong
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,Faculty of Medicine, Department of Anatomy, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Amy Cheuk Yin Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Leanne Lai Hang Chan
- Department of Electrical Engineering, City University of Hong Kong, Hong Kong SAR, China
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Osman T, Lim LW, Ng JS, Tan CH. Fabrication of infrared linear arrays of InAs planar avalanche photodiodes. Opt Express 2022; 30:21758-21763. [PMID: 36224888 DOI: 10.1364/oe.460017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/20/2022] [Indexed: 06/16/2023]
Abstract
We report a, to the best of our knowledge, new device fabrication process for 128-pixel linear arrays of InAs planar avalanche photodiodes, utilizing selective area implantation of Beryllium ions into epitaxially-grown InAs wafers. The pixels exhibited uniform avalanche gain and responsivity. Room temperature responsivity values at 1550 and 2004 nm wavelengths are 0.49 ± 0.017 and 0.89 ± 0.024 A/W, respectively. Reverse dark current-voltage and avalanche gain measurements were carried out at different temperatures (from room temperature to 150 K). At 200 K at -15 V reverse bias, the pixels exhibited an avalanche gain of 22.5 ± 1.18 and dark current density of 0.68 ± 0.48 A/cm2.
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21
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Pak S, Choi G, Roy J, Poon CH, Lee J, Cho D, Lee M, Lim LW, Bao S, Yang S, Yang S. Altered synaptic plasticity of the longitudinal dentate gyrus network in noise-induced anxiety. iScience 2022; 25:104364. [PMID: 35620435 PMCID: PMC9127171 DOI: 10.1016/j.isci.2022.104364] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/31/2022] [Accepted: 05/03/2022] [Indexed: 12/20/2022] Open
Abstract
Anxiety is characteristic comorbidity of noise-induced hearing loss (NIHL), which causes physiological changes within the dentate gyrus (DG), a subfield of the hippocampus that modulates anxiety. However, which DG circuit underlies hearing loss-induced anxiety remains unknown. We utilize an NIHL mouse model to investigate short- and long-term synaptic plasticity in DG networks. The recently discovered longitudinal DG-DG network is a collateral of DG neurons synaptically connected with neighboring DG neurons and displays robust synaptic efficacy and plasticity. Furthermore, animals with NIHL demonstrate increased anxiety-like behaviors similar to a response to chronic restraint stress. These behaviors are concurrent with enhanced synaptic responsiveness and suppressed short- and long-term synaptic plasticity in the longitudinal DG-DG network but not in the transverse DG-CA3 connection. These findings suggest that DG-related anxiety is typified by synaptic alteration in the longitudinal DG-DG network. Traumatic noise-induced hearing loss enhances anxiety-like behaviors The longitudinal DG-DG network displays robust synaptic efficacy and plasticity Abnormal anxiety is associated with synaptic alterations of the DG-DG network DG-related brain disorders might stem from dysfunctional DG-DG networks
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Yu WS, Guan L, Kai Tan SZ, Shrestha S, Or YZ, Lufkin T, Lin VCL, Lim LW. Tetratricopeptide repeat domain 9A knockout induces social anxiety and impairs offense behaviors in female mice. Iran J Basic Med Sci 2022; 25:698-703. [PMID: 35949301 PMCID: PMC9320210 DOI: 10.22038/ijbms.2022.63044.13932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/12/2022] [Indexed: 11/06/2022]
Abstract
Objectives The involvement of tetratricopeptide repeat domain 9A (TTC9A) in anxiety-like behaviors through estrogen action has been reported in female mice, this study further investigated its effects on social anxiety and aggressive behaviors. Materials and sMethods Using female Ttc9a knockout (Ttc9a-/-) mice, the role of TTC9A in anxiety was investigated in non-social and social environments through home-cage emergence and social interaction tests, respectively, whereas aggressive behaviors were examined under the female intruder test. Results We observed significant social behavioral deficits with pronounced social and non-social anxiogenic phenotypes in female Ttc9a-/- mice. When tested for aggressive-like behaviors, we found a reduction in offense in Ttc9a-/- animals, suggesting that TTC9A deficiency impairs the offense responses in female mice. Conclusion Future study investigating mechanisms underlying the social anxiety-like behavioral changes in Ttc9a-/- mice may promote the understanding of social and anxiety disorders.
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Affiliation(s)
- Wing Shan Yu
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, P.R. China,Theses authors contributed eqully to this work
| | - Li Guan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, P.R. China,Department of Physiology, Guangzhou University of Chinese Medicine, Guangdong, P.R. China,Theses authors contributed eqully to this work
| | - Shawn Zheng Kai Tan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, P.R. China
| | - Smeeta Shrestha
- School of Biological Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore ,School of Basic and Applied Sciences, Dayananda Sagar University, Bangalore, India
| | - Yu Zuan Or
- School of Biological Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore
| | - Thomas Lufkin
- Department of Biology, Clarkson University, Potsdam, New York, United States
| | - Valerie CL Lin
- School of Biological Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore ,Corresponding authors: Valerie Chun Ling Lin. School of Biological Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637551. ; Lee Wei Lim. Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, P.R. China.
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, P.R. China,Corresponding authors: Valerie Chun Ling Lin. School of Biological Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637551. ; Lee Wei Lim. Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, P.R. China.
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23
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Uddin MS, Lim LW. Glial cells in Alzheimer's disease: From neuropathological changes to therapeutic implications. Ageing Res Rev 2022; 78:101622. [PMID: 35427810 DOI: 10.1016/j.arr.2022.101622] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 04/04/2022] [Accepted: 04/08/2022] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that usually develops slowly and progressively worsens over time. Although there has been increasing research interest in AD, its pathogenesis is still not well understood. Although most studies primarily focus on neurons, recent research findings suggest that glial cells (especially microglia and astrocytes) are associated with AD pathogenesis and might provide various possible therapeutic targets. Growing evidence suggests that microglia can provide protection against AD pathogenesis, as microglia with weakened functions and impaired responses to Aβ proteins are linked with elevated AD risk. Interestingly, numerous findings also suggest that microglial activation can be detrimental to neurons. Indeed, microglia can induce synapse loss via the engulfment of synapses, possibly through a complement-dependent process. Furthermore, they can worsen tau pathology and release inflammatory factors that cause neuronal damage directly or through the activation of neurotoxic astrocytes. Astrocytes play a significant role in various cerebral activities. Their impairment can mediate neurodegeneration and ultimately the retraction of synapses, resulting in AD-related cognitive deficits. Deposition of Aβ can result in astrocyte reactivity, which can further lead to neurotoxic effects and elevated secretion of inflammatory mediators and cytokines. Moreover, glial-induced inflammation in AD can exert both beneficial and harmful effects. Understanding the activities of astrocytes and microglia in the regulation of AD pathogenesis would facilitate the development of novel therapies. In this article, we address the implications of microglia and astrocytes in AD pathogenesis. We also discuss the mechanisms of therapeutic agents that exhibit anti-inflammatory effects against AD.
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Affiliation(s)
- Md Sahab Uddin
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
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Yu WS, Tse ACK, Guan L, Chiu JLY, Tan SZK, Khairuddin S, Agadagba SK, Lo ACY, Fung ML, Chan YS, Chan LLH, Lim LW. Antidepressant-like effects of transcorneal electrical stimulation in rat models. Brain Stimul 2022; 15:843-856. [DOI: 10.1016/j.brs.2022.05.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/04/2022] [Accepted: 05/25/2022] [Indexed: 11/02/2022] Open
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Roy J, Wong KY, Aquili L, Uddin MS, Heng BC, Tipoe GL, Wong KH, Fung ML, Lim LW. Role of melatonin in Alzheimer's disease: From preclinical studies to novel melatonin-based therapies. Front Neuroendocrinol 2022; 65:100986. [PMID: 35167824 DOI: 10.1016/j.yfrne.2022.100986] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/21/2022] [Accepted: 02/07/2022] [Indexed: 12/11/2022]
Abstract
Melatonin and novel melatonin-based therapies such as melatonin-containing hybrid molecules, melatonin analogues, and melatonin derivatives have been investigated as potential therapeutics against Alzheimer's disease (AD) pathogenesis. In this review, we examine the developmental trends of melatonin therapies for AD from 1997 to 2021. We then highlight the neuroprotective mechanisms of melatonin therapy derived from preclinical studies. These mechanisms include the alleviation of amyloid-related burden, neurofibrillary tangle accumulation, oxidative stress, neuroinflammation, apoptosis, mitochondrial dysfunction, and impaired neuroplasticity and neurotransmission. We further illustrate the beneficial effects of melatonin on behavior in animal models of AD. Next, we discuss the clinical effects of melatonin on sleep, cognition, behavior, psychiatric symptoms, electroencephalography findings, and molecular biomarkers in patients with mild cognitive impairment and AD. We then explore the effectiveness of novel melatonin-based therapies. Lastly, we discuss the limitations of current melatonin therapies for AD and suggest two emerging research themes for future study.
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Affiliation(s)
- Jaydeep Roy
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kan Yin Wong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Luca Aquili
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; College of Science, Health, Engineering and Education, Discipline of Psychology, Murdoch University, Perth, Australia
| | - Md Sahab Uddin
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Boon Chin Heng
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Peking University School of Stomatology, Beijing, China
| | - George Lim Tipoe
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kah Hui Wong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Man Lung Fung
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
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Svirin E, Veniaminova E, Costa-Nunes JP, Gorlova A, Umriukhin A, Kalueff AV, Proshin A, Anthony DC, Nedorubov A, Tse ACK, Walitza S, Lim LW, Lesch KP, Strekalova T. Predation Stress Causes Excessive Aggression in Female Mice with Partial Genetic Inactivation of Tryptophan Hydroxylase-2: Evidence for Altered Myelination-Related Processes. Cells 2022; 11:cells11061036. [PMID: 35326487 PMCID: PMC8947002 DOI: 10.3390/cells11061036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/11/2022] [Accepted: 03/15/2022] [Indexed: 01/27/2023] Open
Abstract
The interaction between brain serotonin (5-HT) deficiency and environmental adversity may predispose females to excessive aggression. Specifically, complete inactivation of the gene encoding tryptophan hydroxylase-2 (Tph2) results in the absence of neuronal 5-HT synthesis and excessive aggressiveness in both male and female null mutant (Tph2−/−) mice. In heterozygous male mice (Tph2+/−), there is a moderate reduction in brain 5-HT levels, and when they are exposed to stress, they exhibit increased aggression. Here, we exposed female Tph2+/− mice to a five-day rat predation stress paradigm and assessed their emotionality and social interaction/aggression-like behaviors. Tph2+/− females exhibited excessive aggression and increased dominant behavior. Stressed mutants displayed altered gene expression of the 5-HT receptors Htr1a and Htr2a, glycogen synthase kinase-3 β (GSK-3β), and c-fos as well as myelination-related transcripts in the prefrontal cortex: myelin basic protein (Mbp), proteolipid protein 1 (Plp1), myelin-associated glycoprotein (Mag), and myelin oligodendrocyte glycoprotein (Mog). The expression of the plasticity markers synaptophysin (Syp) and cAMP response element binding protein (Creb), but not AMPA receptor subunit A2 (GluA2), were affected by genotype. Moreover, in a separate experiment, naïve female Tph2+/− mice showed signs of enhanced stress resilience in the modified swim test with repeated swimming sessions. Taken together, the combination of a moderate reduction in brain 5-HT with environmental challenges results in behavioral changes in female mice that resemble the aggression-related behavior and resilience seen in stressed male mutants; additionally, the combination is comparable to the phenotype of null mutants lacking neuronal 5-HT. Changes in myelination-associated processes are suspected to underpin the molecular mechanisms leading to aggressive behavior.
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Affiliation(s)
- Evgeniy Svirin
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands; (E.S.); (K.-P.L.)
- Division of Molecular Psychiatry, Center of Mental Health, University of Würzburg, 97080 Würzburg, Germany
- Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, 125315 Moscow, Russia
| | - Ekaterina Veniaminova
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov University, 119991 Moscow, Russia; (E.V.); (J.P.C.-N.); (A.G.); (A.U.); (D.C.A.)
| | - João Pedro Costa-Nunes
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov University, 119991 Moscow, Russia; (E.V.); (J.P.C.-N.); (A.G.); (A.U.); (D.C.A.)
- Institute of Molecular Medicine, New University of Lisbon, 1649-028 Lisbon, Portugal
| | - Anna Gorlova
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov University, 119991 Moscow, Russia; (E.V.); (J.P.C.-N.); (A.G.); (A.U.); (D.C.A.)
| | - Aleksei Umriukhin
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov University, 119991 Moscow, Russia; (E.V.); (J.P.C.-N.); (A.G.); (A.U.); (D.C.A.)
| | - Allan V. Kalueff
- Neuroscience Program, Sirius University, 354340 Sochi, Russia;
- Moscow Institute of Physics and Technology, School of Biological and Medical Physics, 141701 Dolgoprudny, Russia
- Institute of Natural Sciences, Ural Federal University, 620002 Yekaterinburg, Russia
| | - Andrey Proshin
- P.K. Anokhin Research Institute of Normal Physiology, 125315 Moscow, Russia;
| | - Daniel C. Anthony
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov University, 119991 Moscow, Russia; (E.V.); (J.P.C.-N.); (A.G.); (A.U.); (D.C.A.)
- Department of Pharmacology, Oxford University, Oxford OX1 3QT, UK
| | - Andrey Nedorubov
- Institute of Translational Medicine and Biotechnology, Sechenov University, 119991 Moscow, Russia;
| | - Anna Chung Kwan Tse
- Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China;
| | - Susanne Walitza
- Department for Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, 8032 Zurich, Switzerland;
| | - Lee Wei Lim
- Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China;
- Correspondence: or (L.W.L.); (T.S.); Tel.: +852-3917-6830 (L.W.L.); +31-43-38-84-108 (T.S.)
| | - Klaus-Peter Lesch
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands; (E.S.); (K.-P.L.)
- Division of Molecular Psychiatry, Center of Mental Health, University of Würzburg, 97080 Würzburg, Germany
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov University, 119991 Moscow, Russia; (E.V.); (J.P.C.-N.); (A.G.); (A.U.); (D.C.A.)
| | - Tatyana Strekalova
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands; (E.S.); (K.-P.L.)
- Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, 125315 Moscow, Russia
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov University, 119991 Moscow, Russia; (E.V.); (J.P.C.-N.); (A.G.); (A.U.); (D.C.A.)
- Correspondence: or (L.W.L.); (T.S.); Tel.: +852-3917-6830 (L.W.L.); +31-43-38-84-108 (T.S.)
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Prowacki M, Lim LW, Aquili L. Eyeblink rate, a putative dopamine marker, predicts negative reinforcement learning by tDCS of the dlPFC. Brain Stimul 2022; 15:533-535. [DOI: 10.1016/j.brs.2022.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 02/15/2022] [Accepted: 02/21/2022] [Indexed: 01/05/2023] Open
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Poon CH, Tan SZK, Sheng V, Wang S, Aquili L, Lim LW. A Brief Comparative Look at Experimental Memory Editing Techniques for Cognitive Dysfunction. Curr Alzheimer Res 2021; 18:841-848. [PMID: 34879803 DOI: 10.2174/1567205018666211208142036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 07/20/2020] [Accepted: 07/29/2020] [Indexed: 11/22/2022]
Abstract
Neuroscience has long sought to develop methods that can "edit" or even "erase" mem- ories, with the aim to provide treatments for memory-related neurological and psychiatric diseases such as anxiety and addiction. Current efforts are heavily focused on modifying cognitive behavio- ral therapy protocols or pharmacological treatments, but the efficacy and safety of these methods have been called into question by several studies. Advances in modern technology and the rapid emergence of techniques that can directly stimulate/alter neuronal activity, such as neuromodula- tion, have great potential in achieving the goal of memory modification for treating dementia such as Alzheimer's disease. However, more research and validation studies are required before these memory editing technologies can be applied clinically. In this mini-review, we compare and high- light the advantages and disadvantages of cognitive behavioral therapy, pharmacological methods, and neuromodulation techniques. We believe that neuromodulation techniques will play a key role in overcoming the challenges of translating memory-manipulating techniques to clinical applications.
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Affiliation(s)
- Chi Him Poon
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. China
| | - Shawn Zheng Kai Tan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. China
| | - Victoria Sheng
- School of Biological Sciences, The University of Hong Kong, Hong Kong. China
| | - Shouyan Wang
- Neural and Intelligence Engineering Center, Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai. China
| | - Luca Aquili
- College of Health & Human Sciences, Charles Darwin University, Darwin, Northern Territory. Australia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. China
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Chong PS, Poon CH, Roy J, Tsui KC, Lew SY, Phang MWL, Tan RJY, Cheng PG, Fung ML, Wong KH, Lim LW. Neurogenesis-dependent antidepressant-like activity of Hericium erinaceus in an animal model of depression. Chin Med 2021; 16:132. [PMID: 34876186 PMCID: PMC8650354 DOI: 10.1186/s13020-021-00546-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/27/2021] [Indexed: 12/26/2022] Open
Abstract
Background Depression is a severe neuropsychiatric disorder that affects more than 264 million people worldwide. The efficacy of conventional antidepressants are barely adequate and many have side effects. Hericium erinaceus (HE) is a medicinal mushroom that has been reported to have therapeutic potential for treating depression. Methods Animals subjected to chronic restraint stress were given 4 weeks HE treatment. Animals were then screened for anxiety and depressive-like behaviours. Gene and protein assays, as well as histological analysis were performed to probe the role of neurogenesis in mediating the therapeutic effect of HE. Temozolomide was administered to validate the neurogenesis-dependent mechanism of HE. Results The results showed that 4 weeks of HE treatment ameliorated depressive-like behaviours in mice subjected to 14 days of restraint stress. Further molecular assays demonstrated the 4-week HE treatment elevated the expression of several neurogenesis-related genes and proteins, including doublecortin, nestin, synaptophysin, brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB), phosphorylated extracellular signal-regulated kinase, and phosphorylated cAMP response element-binding protein (pCREB). Increased bromodeoxyuridine-positive cells were also observed in the dentate gyrus of the hippocampus, indicating enhanced neurogenesis. Neurogenesis blocker temozolomide completely abolished the antidepressant-like effects of HE, confirming a neurogenesis-dependent mechanism. Moreover, HE induced anti-neuroinflammatory effects through reducing astrocyte activation in the hippocampus, which was also abolished with temozolomide administration. Conclusion HE exerts antidepressant effects by promoting neurogenesis and reducing neuroinflammation through enhancing the BDNF-TrkB-CREB signalling pathway. Supplementary Information The online version contains supplementary material available at 10.1186/s13020-021-00546-8.
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Affiliation(s)
- Pit Shan Chong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China
| | - Chi Him Poon
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China
| | - Jaydeep Roy
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China
| | - Ka Chun Tsui
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China
| | - Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Michael Weng Lok Phang
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Rachael Julia Yuenyinn Tan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China
| | - Poh Guat Cheng
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.,Ganofarm R&D SDN BHD, 01-01, SKYPOD SQUARE, Persiaran Puchong Jaya Selatan, Bandar Puchong Jaya, 47100, Puchong, Selangor, Malaysia
| | - Man-Lung Fung
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China
| | - Kah Hui Wong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China. .,Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, China.
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Poon CH, Tsui KC, Chau SC, Chong PS, Lui SWY, Aquili L, Wong KH, Lim LW. Functional Roles of Neuronal Nitric Oxide Synthase in Neurodegenerative Diseases and Mood Disorders. Curr Alzheimer Res 2021; 18:831-840. [PMID: 34719364 DOI: 10.2174/1567205018666211022164025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/30/2020] [Accepted: 07/03/2020] [Indexed: 11/22/2022]
Abstract
Nitric oxide synthase (NOS) is well known for its involvement in the regulation of the nervous, cardiovascular, and immune systems. Neuronal NOS (nNOS) is the most characterized NOS among all the isoforms. It accounts for most of the production of nitric oxide (NO) in the ner- vous system required for synaptic transmission and neuroplasticity. Previous studies have described the localization of nNOS in specific brain regions of interest. There is substantial evidence in the literature suggesting that nNOS signaling has significant involvement in several disease pathologies. However, the association between brain nNOS expression profiles and disease remains largely unknown. In this review, we attempt to delineate the contribution of nNOS signaling in memory and mood disorders in order to achieve a better understanding of nNOS in disease modulation.
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Affiliation(s)
- Chi Him Poon
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
| | - Ka Chun Tsui
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
| | - Sze Chun Chau
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
| | - Pit Shan Chong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
| | - Sylvia Wing Yan Lui
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
| | - Luca Aquili
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
| | - Kah Hui Wong
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR. China
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Strekalova T, Svirin E, Veniaminova E, Kopeikina E, Veremeyko T, Yung AWY, Proshin A, Walitza S, Anthony DC, Lim LW, Lesch KP, Ponomarev ED. ASD-like behaviors, a dysregulated inflammatory response and decreased expression of PLP1 characterize mice deficient for sialyltransferase ST3GAL5. Brain Behav Immun Health 2021; 16:100306. [PMID: 34589798 PMCID: PMC8474501 DOI: 10.1016/j.bbih.2021.100306] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 06/22/2021] [Accepted: 07/24/2021] [Indexed: 01/28/2023] Open
Abstract
Gangliosides are glycosphingolipids, which are abundant in brain, are known to modulate ion channels and cell-to-cell communication. Deficiencies can result in aberrant myelination and altered immune responses, which can give rise to neurodevelopmental psychiatric disorders. However, to date, little mechanistic data is available on how ganglioside deficiencies contribute to the behavioural disorders. In humans, the loss of lactosylceramide-alpha-2,3-sialyltransferase (ST3Gal5) leads to a severe neuropathology, but in ST3Gal5 knock-out (St3gal5−/−) mice the absence of GM3 and associated a-, b- and c-series gangliosides is partially compensated by 0-series gangliosides and there is no overt behavioural phenotype. Here, we sought to examine the behavioural and molecular consequences of GM3 loss more closely. Mutants of both sexes exhibited impaired conditioned taste aversion in an inhibitory learning task and anxiety-like behaviours in the open field, moderate motor deficits, abnormal social interactions, excessive grooming and rearing behaviours. Taken together, the aberrant behaviours are suggestive of an autism spectrum disorder (ASD)-like syndrome. Molecular analysis showed decreased gene and protein expression of proteolipid protein-1 (Plp1) and over expression of proinflammatory cytokines, which has been associated with ASD-like syndromes. The inflammatory and behavioural responses to lipopolysaccharide (LPS) were also altered in the St3gal5−/− mice compared to wild-type, which is indicative of the importance of GM3 gangliosides in regulating immune responses. Together, the St3gal5−/− mice display ASD-like behavioural features, altered response to systemic inflammation, signs of hypomyelination and neuroinflammation, which suggests that deficiency in a- and b-series gangliosides could contribute to the development of an ASD-like pathology in humans. St3gal5−/− mice exhibit aberrant social, motor and cognitive behavior that is reminiscent of ASD-like syndrome. Interleukin1β is upregulated in the brain and spleen of St3gal5−/− of both sexes. Mutants display reduced gene and protein expression of the myelin protein Plp1. LPS induces sex-dependent abnormalities in the inflammatory response and social behavior in the St3gal5−/− mice. St3gal5−/− mice can be used to study the behavioural consequence of a- and b-series ganglioside deficiency
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Affiliation(s)
- Tatyana Strekalova
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, the Netherlands.,Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov First Moscow State Medical University, Moscow, Russia.,Division of Molecular Psychiatry, Center of Mental Health, University of Würzburg, Würzburg, Germany
| | - Evgeniy Svirin
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, the Netherlands.,Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov First Moscow State Medical University, Moscow, Russia.,Division of Molecular Psychiatry, Center of Mental Health, University of Würzburg, Würzburg, Germany
| | - Ekaterina Veniaminova
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, the Netherlands.,Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Ekaterina Kopeikina
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Tatyana Veremeyko
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Amanda W Y Yung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Andrey Proshin
- P.K. Anokhin Research Institute of Normal Physiology, Moscow, Russia
| | - Susanne Walitza
- Department for Child and Adolescent Psychiatry and Psychotherapy of the University of Zurich and the University Hospital of Psychiatry, Zurich, Switzerland
| | - Daniel C Anthony
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov First Moscow State Medical University, Moscow, Russia.,Department of Pharmacology, Oxford University, Oxford, United Kingdom
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Klaus-Peter Lesch
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, the Netherlands.,Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine and Department of Normal Physiology, Sechenov First Moscow State Medical University, Moscow, Russia.,Division of Molecular Psychiatry, Center of Mental Health, University of Würzburg, Würzburg, Germany
| | - Eugene D Ponomarev
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.,Kunmin Institute of Zoology, Chinese University of Hong Kong Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Kunmin-Hong Kong, China
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Chan HJ, Yanshree, Roy J, Tipoe GL, Fung ML, Lim LW. Therapeutic Potential of Human Stem Cell Implantation in Alzheimer's Disease. Int J Mol Sci 2021; 22:10151. [PMID: 34576314 PMCID: PMC8471075 DOI: 10.3390/ijms221810151] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive debilitating neurodegenerative disease and the most common form of dementia in the older population. At present, there is no definitive effective treatment for AD. Therefore, researchers are now looking at stem cell therapy as a possible treatment for AD, but whether stem cells are safe and effective in humans is still not clear. In this narrative review, we discuss both preclinical studies and clinical trials on the therapeutic potential of human stem cells in AD. Preclinical studies have successfully differentiated stem cells into neurons in vitro, indicating the potential viability of stem cell therapy in neurodegenerative diseases. Preclinical studies have also shown that stem cell therapy is safe and effective in improving cognitive performance in animal models, as demonstrated in the Morris water maze test and novel object recognition test. Although few clinical trials have been completed and many trials are still in phase I and II, the initial results confirm the outcomes of the preclinical studies. However, limitations like rejection, tumorigenicity, and ethical issues are still barriers to the advancement of stem cell therapy. In conclusion, the use of stem cells in the treatment of AD shows promise in terms of effectiveness and safety.
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Affiliation(s)
| | | | | | | | | | - Lee Wei Lim
- School of Biomedical, Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (H.J.C.); (Y.); (J.R.); (G.L.T.); (M.-L.F.)
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Uddin MS, Yu WS, Lim LW. Exploring ER stress response in cellular aging and neuroinflammation in Alzheimer's disease. Ageing Res Rev 2021; 70:101417. [PMID: 34339860 DOI: 10.1016/j.arr.2021.101417] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 02/06/2023]
Abstract
One evident hallmark of Alzheimer's disease (AD) is the irregular accumulation of proteins due to changes in proteostasis involving endoplasmic reticulum (ER) stress. To alleviate ER stress and reinstate proteostasis, cells undergo an integrated signaling cascade called the unfolded protein response (UPR) that reduces the number of misfolded proteins and inhibits abnormal protein accumulation. Aging is associated with changes in the expression of ER chaperones and folding enzymes, leading to the impairment of proteostasis, and accumulation of misfolded proteins. The disrupted initiation of UPR prevents the elimination of unfolded proteins, leading to ER stress. In AD, the accumulation of misfolded proteins caused by sustained cellular stress leads to neurodegeneration and neuronal death. Current research has revealed that ER stress can trigger an inflammatory response through diverse transducers of UPR. Although the involvement of a neuroinflammatory component in AD has been documented for decades, whether it is a contributing factor or part of the neurodegenerative events is so far unknown. Besides, a feedback loop occurs between neuroinflammation and ER stress, which is strongly associated with neurodegenerative processes in AD. In this review, we focus on the current research on ER stress and UPR in cellular aging and neuroinflammatory processes, leading to memory impairment and synapse dysfunction in AD.
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Abstract
The pressures of the ethos of “publish or perish” in academia has led to a multitude of issues for science and scientists. In this paper, we argue that the existentialist philosophy concept of authenticity would be useful for scientists to prevent issues of reproducibility, data manipulation, fraud, and mentorship. We highlight some major caveats and call for policies to prevent them. Overall, we propose a way for scientists to ensure they do not succumb to the pressures of a career in science.
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Affiliation(s)
- Shawn Zheng Kai Tan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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Subermaniam K, Teoh SL, Yow YY, Tang YQ, Lim LW, Wong KH. Marine algae as emerging therapeutic alternatives for depression: A review. Iran J Basic Med Sci 2021; 24:997-1013. [PMID: 34804417 PMCID: PMC8591755 DOI: 10.22038/ijbms.2021.54800.12291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 06/21/2021] [Indexed: 12/24/2022]
Abstract
Depression is a complex heterogeneous brain disorder characterized by a range of symptoms, resulting in psychomotor and cognitive disabilities and suicidal thoughts. Its prevalence has reached an alarming level affecting millions of people globally. Despite advances in current pharmacological treatments, the heterogenicity of clinical response and incidences of adverse effects have shifted research focus to identification of new natural substances with minimal or no adverse effects as therapeutic alternatives. Marine algae-derived extracts and their constituents are considered potential sources of secondary metabolites with diverse beneficial effects. Marine algae with enormous health benefits are emerging as a natural source for discovering new alternative antidepressants. Its medicinal properties exhibited shielding efficacy against neuroinflammation, oxidative stress, and mitochondrial dysfunction, which are indicated to underlie the pathogenesis of many neurological disorders. Marine algae have been found to ameliorate depressive-like symptoms and behaviors in preclinical and clinical studies by restoring monoaminergic neurotransmission, hypothalamic-pituitary-adrenal axis function, neuroplasticity, and continuous neurogenesis in the dentate gyrus of the hippocampus via modulating brain-derived neurotrophic factors and antineuroinflammatory activity. Although antidepressant effects of marine algae have not been validated in comparison with currently available synthetic antidepressants, they have been reported to have effects on the pathophysiology of depression, thus suggesting their potential as novel antidepressants. In this review, we analyzed the currently available research on the potential benefits of marine algae on depression, including their effects on the pathophysiology of depression, potential clinical relevance of their antidepressant effects in preclinical and clinical studies, and the underlying mechanisms of these effects.
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Affiliation(s)
- Kogilavani Subermaniam
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia,Training Management Division, Ministry of Health Malaysia, 62675 Putrajaya, Malaysia
| | - Seong Lin Teoh
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia
| | - Yoon-Yen Yow
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Yin Quan Tang
- School of Biosciences, Faculty of Health & Medical Sciences, Taylor’s University Lakeside Campus, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia,Corresponding author: K.H. Wong, Department of Anatomy, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia. Tel: +60379674729; Fax: +60379674724;
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Roy J, Tsui KC, Ng J, Fung ML, Lim LW. Regulation of Melatonin and Neurotransmission in Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms22136841. [PMID: 34202125 PMCID: PMC8268832 DOI: 10.3390/ijms22136841] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/20/2022] Open
Abstract
Alzheimer’s disease is a neurodegenerative disorder associated with age, and is characterized by pathological markers such as amyloid-beta plaques and neurofibrillary tangles. Symptoms of AD include cognitive impairments, anxiety and depression. It has also been shown that individuals with AD have impaired neurotransmission, which may result from the accumulation of amyloid plaques and neurofibrillary tangles. Preclinical studies showed that melatonin, a monoaminergic neurotransmitter released from the pineal gland, is able to ameliorate AD pathologies and restore cognitive impairments. Theoretically, inhibition of the pathological progression of AD by melatonin treatment should also restore the impaired neurotransmission. This review aims to explore the impact of AD on neurotransmission, and whether and how melatonin can enhance neurotransmission via improving AD pathology.
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Tan SZK, Poon CH, Chan YS, Lim LW. Prelimbic cortical stimulation disrupts fear memory consolidation through ventral hippocampal dopamine D 2 receptors. Br J Pharmacol 2021; 178:3587-3601. [PMID: 33899943 DOI: 10.1111/bph.15505] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/18/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Anxiety disorders pose one of the biggest threats to mental health worldwide, yet current therapeutics have been mostly ineffective due to issues with relapse, efficacy and toxicity of the medications. Deep brain stimulation (DBS) is a promising therapy for treatment-resistant psychiatric disorders including anxiety, but very little is known about the effects of deep brain stimulation on fear memories. EXPERIMENTAL APPROACH In this study, we employed a standard tone-footshock fear conditioning paradigm and modified plus maze discriminative avoidance task to probe the effects of prelimbic cortex deep brain stimulation on various stages of memory. KEY RESULTS We identified memory consolidation stage as a critical time point to disrupt fear memory via prelimbic cortex deep brain stimulation. The observed disruption was partially modulated by the inactivation of the ventral hippocampus and the transient changes in ventral hippocampus dopamine (D2 ) receptors expression upon prelimbic cortex deep brain stimulation. We also observed wide-scale changes of various neurotransmitters and their metabolites in ventral hippocampus, confirming its important role in response to prelimbic cortex deep brain stimulation. CONCLUSION AND IMPLICATIONS These findings highlight the molecular mechanism in the ventral hippocampus in response to prelimbic cortex stimulation and may have translational value, indicating that targeting the prelimbic cortex in the memory consolidation stage via non-invasive neuromodulation techniques may be a feasible therapeutic strategy against anxiety disorders.
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Affiliation(s)
- Shawn Zheng Kai Tan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Chi Him Poon
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Lew SY, Teoh SL, Lim SH, Lim LW, Wong KH. Discovering the Potentials of Medicinal Mushrooms in Combating Depression - A Review. Mini Rev Med Chem 2021; 20:1518-1531. [PMID: 32452327 DOI: 10.2174/1389557520666200526125534] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 01/21/2023]
Abstract
Depression is the most common form of mental illness and the major cause of disability worldwide. Symptoms of depression, including feelings of intense sadness and hopelessness, may occur after a specific event or in response to a gradual decline in health and functional status, often associated with aging. Current therapies for treating these symptoms include antidepressant drugs, counseling and behavioral therapy. However, antidepressant drugs are associated with mild to severe adverse effects, which has prompted the need for better treatment options. Medicinal mushrooms are valuable sources of food and medicine and are increasingly being used as supplements or as alternative medicines in standard healthcare. Numerous studies have provided insights into the neuroprotective effects of medicinal mushrooms, which are attributed to their antioxidant, anti-neuroinflammatory, cholinesterase inhibitory and neuroprotective properties. In this review, we comprehensively examine the role of these medicinal mushrooms in the treatment of depression. However, to apply these natural products in clinical settings, the therapeutic agent needs to be properly evaluated, including the active ingredients, the presence of synergistic effects, efficient extraction methods, and stabilization of the active ingredients for delivery into the body as well as crossing the blood-brain barrier.
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Affiliation(s)
- Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Seong Lin Teoh
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Center, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia
| | - Siew Huah Lim
- Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Hossain MF, Wang N, Chen R, Li S, Roy J, Uddin MG, Li Z, Lim LW, Song YQ. Exploring the multifunctional role of melatonin in regulating autophagy and sleep to mitigate Alzheimer's disease neuropathology. Ageing Res Rev 2021; 67:101304. [PMID: 33610813 DOI: 10.1016/j.arr.2021.101304] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022]
Abstract
Melatonin (MLT) is a neurohormone that is regulated by the circadian clock and plays multifunctional roles in numerous neurodegenerative disorders, such as Alzheimer's disease (AD). AD is the most common form of dementia and is associated with the degradation of axons and synapses resulting in memory loss and cognitive impairment. Despite extensive research, there is still no effective cure or specific treatment to prevent the progression of AD. The pathogenesis of AD involves atrophic alterations in the brain that also result in circadian alterations, sleep disruption, and autophagic dysfunction. In this scenario, MLT and autophagy play a central role in removing the misfolded protein aggregations. MLT also promotes autophagy through inhibiting methamphetamine toxicity to protect against neuronal cell death in AD brain. Besides, MLT plays critical roles as either a pro-autophagic indicator or anti-autophagic regulator depending on the phase of autophagy. MLT also has antioxidant properties that can counteract mitochondrial damage, oxidative stress, and apoptosis. Aging, a major risk factor for AD, can change sleep patterns and sleep quality, and MLT can improve sleep quality through regulating sleep cycles. The primary purpose of this review is to explore the putative mechanisms of the beneficial effects of MLT in AD patients. Furthermore, we also summarize the findings from preclinical and clinical studies on the multifunctional roles of MLT on autophagic regulation, the control of the circadian clock-associated genes, and sleep regulation.
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Tan SZK, Zhao RC, Chakrabarti S, Stambler I, Jin K, Lim LW. Interdisciplinary Research in Alzheimer's Disease and the Roles International Societies Can Play. Aging Dis 2021; 12:36-41. [PMID: 33532125 PMCID: PMC7801283 DOI: 10.14336/ad.2020.0602] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/02/2020] [Indexed: 01/01/2023] Open
Abstract
An ever-increasing ageing population has elevated Alzheimer's disease to be one of the biggest challenges in modern medicine. Alzheimer's disease is highly complex, and we are still no closer to understanding the causes, let alone an effective treatment. The lack of good experimental models and lack of critical understanding has led to high failure rates of clinical trials with high associated costs, as well as difficulties in implementing treatments. The multifaceted nature of this disease highlights the need for an interdisciplinary approach to address these concerns. In this essay, we suggest how collaborative work can be useful in addressing some of the above issues. We then propose that international organisations and publishers need to support interdisciplinary research by creating platforms, lobbying funders, and pushing for interdisciplinary publications. We further highlight some of the issues involved in implementing these suggestions and argue that willpower of the research community, together with a re-evaluation of evaluation metrics and incentive systems, are needed in order to foster interdisciplinary research. Overall, we emphasise the need for interdisciplinary research in Alzheimer's disease and suggest that international societies should play a huge role in this endeavour.
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Affiliation(s)
- Shawn Zheng Kai Tan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Robert Chunhua Zhao
- International Society on Aging and Disease (ISOAD), Fort Worth, Texas, USA.
- The Executive Committee on Anti-aging and Disease Prevention in the framework of Science and Technology, Pharmacology and Medicine Themes under an Interactive Atlas along the Silk Roads, UNESCO, Paris, France.
- School of Life Sciences, Shanghai University, Shanghai, China.
| | - Sasanka Chakrabarti
- International Society on Aging and Disease (ISOAD), Fort Worth, Texas, USA.
- The Executive Committee on Anti-aging and Disease Prevention in the framework of Science and Technology, Pharmacology and Medicine Themes under an Interactive Atlas along the Silk Roads, UNESCO, Paris, France.
- Department of Biochemistry and Central Research Cell, M M Institute of Medical Sciences and Research, Mullana, India.
| | - Ilia Stambler
- International Society on Aging and Disease (ISOAD), Fort Worth, Texas, USA.
- The Executive Committee on Anti-aging and Disease Prevention in the framework of Science and Technology, Pharmacology and Medicine Themes under an Interactive Atlas along the Silk Roads, UNESCO, Paris, France.
- The Geriatric Medical Center "Shmuel Harofe", Beer Yaakov, affiliated to Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
| | - Kunlin Jin
- International Society on Aging and Disease (ISOAD), Fort Worth, Texas, USA.
- The Executive Committee on Anti-aging and Disease Prevention in the framework of Science and Technology, Pharmacology and Medicine Themes under an Interactive Atlas along the Silk Roads, UNESCO, Paris, France.
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Texas, USA.
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- International Society on Aging and Disease (ISOAD), Fort Worth, Texas, USA.
- The Executive Committee on Anti-aging and Disease Prevention in the framework of Science and Technology, Pharmacology and Medicine Themes under an Interactive Atlas along the Silk Roads, UNESCO, Paris, France.
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Phang MWL, Lew SY, Chung I, Lim WKS, Lim LW, Wong KH. Therapeutic roles of natural remedies in combating hereditary ataxia: A systematic review. Chin Med 2021; 16:15. [PMID: 33509239 PMCID: PMC7841890 DOI: 10.1186/s13020-020-00414-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/17/2020] [Accepted: 12/11/2020] [Indexed: 12/30/2022] Open
Abstract
Background Hereditary ataxia (HA) represents a group of genetically heterogeneous neurodegenerative diseases caused by dysfunction of the cerebellum or disruption of the connection between the cerebellum and other areas of the central nervous system. Phenotypic manifestation of HA includes unsteadiness of stance and gait, dysarthria, nystagmus, dysmetria and complaints of clumsiness. There are no specific treatments for HA. Management strategies provide supportive treatment to reduce symptoms. Objectives This systematic review aimed to identify, evaluate and summarise the published literature on the therapeutic roles of natural remedies in the treatment of HA to provide evidence for clinical practice. Methods A systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Web of Science, PubMed and Science Direct Scopus were thoroughly searched for relevant published articles from June 2007 to July 2020. Results Ten pre-clinical and two clinical studies were eligible for inclusion in this systematic review. We identified the therapeutic roles of medicinal plants Brassica napus, Gardenia jasminoides, Gastrodia elata, Ginkgo biloba, Glycyrrhiza inflata, Paeonia lactiflora, Pueraria lobata and Rehmannia glutinosa; herbal formulations Shaoyao Gancao Tang and Zhengan Xifeng Tang; and medicinal mushroom Hericium erinaceus in the treatment of HA. In this review, we evaluated the mode of actions contributing to their therapeutic effects, including activation of the ubiquitin–proteasome system, activation of antioxidant pathways, maintenance of intracellular calcium homeostasis and regulation of chaperones. We also briefly highlighted the integral cellular signalling pathways responsible for orchestrating the mode of actions. Conclusion We reviewed the therapeutic roles of natural remedies in improving or halting the progression of HA, which warrant further study for applications into clinical practice.
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Affiliation(s)
- Michael Weng Lok Phang
- Department of Anatomy, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Ivy Chung
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - William Kiong-Seng Lim
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak, Kuching, Sarawak, 94300, Malaysia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China.
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia.
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Lew SY, Lim SH, Lim LW, Wong KH. Neuroprotective effects of Hericium erinaceus (Bull.: Fr.) Pers. against high-dose corticosterone-induced oxidative stress in PC-12 cells. BMC Complement Med Ther 2020; 20:340. [PMID: 33176761 PMCID: PMC7656699 DOI: 10.1186/s12906-020-03132-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 10/26/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Hericium erinaceus is a culinary and medicinal mushroom in Traditional Chinese Medicines. It has numerous pharmacological effects including immunomodulatory, anti-tumour, anti-microbial, anti-aging and stimulation of nerve growth factor (NGF) synthesis, but little is known about its potential role in negating the detrimental effects of oxidative stress in depression. The present study investigated the neuroprotective effects of H. erinaceus standardised aqueous extract (HESAE) against high-dose corticosterone-induced oxidative stress in rat pheochromocytoma (PC-12) cells, a cellular model mimicking depression. METHODS PC-12 cells was pre-treated with HESAE for 48 h followed by 400 μM corticosterone for 24 h to induce oxidative stress. Cells in complete medium without any treatment or pre-treated with 3.125 μg/mL desipramine served as the negative and positive controls, respectively. The cell viability, lactate dehydrogenase (LDH) release, endogenous antioxidant enzyme activities, aconitase activity, mitochondrial membrane potentials (MMPs), intracellular reactive oxygen species (ROS) levels and number of apoptotic nuclei were quantified. In addition, HESAE ethanol extract was separated into fractions by chromatographic methods prior to spectroscopic analysis. RESULTS We observed that PC-12 cells treated with high-dose corticosterone at 400 μM had decreased cell viability, reduced endogenous antioxidant enzyme activities, disrupted mitochondrial function, and increased oxidative stress and apoptosis. However, pre-treatment with HESAE ranging from 0.25 to 1 mg/mL had increased cell viability, decreased LDH release, enhanced endogenous antioxidant enzyme activities, restored MMP, attenuated intracellular ROS and protected from ROS-mediated apoptosis. The neuroprotective effects could be attributed to significant amounts of adenosine and herierin III isolated from HESAE. CONCLUSIONS HESAE demonstrated neuroprotective effects against high-dose corticosterone-induced oxidative stress in an in vitro model mimicking depression. HESAE could be a potential dietary supplement to treat depression.
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Affiliation(s)
- Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Siew Huah Lim
- Department of Chemistry, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China, China
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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Khairuddin S, Aquili L, Heng BC, Hoo TLC, Wong KH, Lim LW. Dysregulation of the orexinergic system: A potential neuropeptide target in depression. Neurosci Biobehav Rev 2020; 118:384-396. [DOI: 10.1016/j.neubiorev.2020.07.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/19/2020] [Accepted: 07/31/2020] [Indexed: 12/20/2022]
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Khairuddin S, Ngo FY, Lim WL, Aquili L, Khan NA, Fung ML, Chan YS, Temel Y, Lim LW. A Decade of Progress in Deep Brain Stimulation of the Subcallosal Cingulate for the Treatment of Depression. J Clin Med 2020; 9:jcm9103260. [PMID: 33053848 PMCID: PMC7601903 DOI: 10.3390/jcm9103260] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022] Open
Abstract
Major depression contributes significantly to the global disability burden. Since the first clinical study of deep brain stimulation (DBS), over 446 patients with depression have now undergone this neuromodulation therapy, and 29 animal studies have investigated the efficacy of subgenual cingulate DBS for depression. In this review, we aim to provide a comprehensive overview of the progress of DBS of the subcallosal cingulate in humans and the medial prefrontal cortex, its rodent homolog. For preclinical animal studies, we discuss the various antidepressant-like behaviors induced by medial prefrontal cortex DBS and examine the possible mechanisms including neuroplasticity-dependent/independent cellular and molecular changes. Interestingly, the response rate of subcallosal cingulate Deep brain stimulation marks a milestone in the treatment of depression. DBS achieved response and remission rates of 64–76% and 37–63%, respectively, from clinical studies monitoring patients from 6–24 months. Although some studies showed its stimulation efficacy was limited, it still holds great promise as a therapy for patients with treatment-resistant depression. Overall, further research is still needed, including more credible clinical research, preclinical mechanistic studies, precise selection of patients, and customized electrical stimulation paradigms.
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Affiliation(s)
- Sharafuddin Khairuddin
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L4 Laboratory Block, 21 Sassoon Road, Hong Kong, China; (S.K.); (F.Y.N.); (W.L.L.); (M.-L.F.); (Y.-S.C.)
| | - Fung Yin Ngo
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L4 Laboratory Block, 21 Sassoon Road, Hong Kong, China; (S.K.); (F.Y.N.); (W.L.L.); (M.-L.F.); (Y.-S.C.)
| | - Wei Ling Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L4 Laboratory Block, 21 Sassoon Road, Hong Kong, China; (S.K.); (F.Y.N.); (W.L.L.); (M.-L.F.); (Y.-S.C.)
- Department of Biological Sciences, School of Science and Technology, Sunway University, Bandar Sunway 47500, Malaysia
| | - Luca Aquili
- School of Psychological and Clinical Sciences, Charles Darwin University, NT0815 Darwin, Australia;
| | - Naveed Ahmed Khan
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, Sharjah 26666, UAE;
| | - Man-Lung Fung
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L4 Laboratory Block, 21 Sassoon Road, Hong Kong, China; (S.K.); (F.Y.N.); (W.L.L.); (M.-L.F.); (Y.-S.C.)
| | - Ying-Shing Chan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L4 Laboratory Block, 21 Sassoon Road, Hong Kong, China; (S.K.); (F.Y.N.); (W.L.L.); (M.-L.F.); (Y.-S.C.)
| | - Yasin Temel
- Departments of Neuroscience and Neurosurgery, Maastricht University, 6229ER Maastricht, The Netherlands;
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L4 Laboratory Block, 21 Sassoon Road, Hong Kong, China; (S.K.); (F.Y.N.); (W.L.L.); (M.-L.F.); (Y.-S.C.)
- Department of Biological Sciences, School of Science and Technology, Sunway University, Bandar Sunway 47500, Malaysia
- Correspondence:
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Wong KY, Roy J, Fung ML, Heng BC, Zhang C, Lim LW. Relationships between Mitochondrial Dysfunction and Neurotransmission Failure in Alzheimer's Disease. Aging Dis 2020; 11:1291-1316. [PMID: 33014538 PMCID: PMC7505271 DOI: 10.14336/ad.2019.1125] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022] Open
Abstract
Besides extracellular deposition of amyloid beta and formation of phosphorylated tau in the brains of patients with Alzheimer's disease (AD), the pathogenesis of AD is also thought to involve mitochondrial dysfunctions and altered neurotransmission systems. However, none of these components can describe the diverse cognitive, behavioural, and psychiatric symptoms of AD without the pathologies interacting with one another. The purpose of this review is to understand the relationships between mitochondrial and neurotransmission dysfunctions in terms of (1) how mitochondrial alterations affect cholinergic and monoaminergic systems via disruption of energy metabolism, oxidative stress, and apoptosis; and (2) how different neurotransmission systems drive mitochondrial dysfunction via increasing amyloid beta internalisation, oxidative stress, disruption of mitochondrial permeabilisation, and mitochondrial trafficking. All these interactions are separately discussed in terms of neurotransmission systems. The association of mitochondrial dysfunctions with alterations in dopamine, norepinephrine, and histamine is the prospective goal in this research field. By unfolding the complex interactions surrounding mitochondrial dysfunction in AD, we can better develop potential treatments to delay, prevent, or cure this devastating disease.
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Affiliation(s)
- Kan Yin Wong
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Jaydeep Roy
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Man Lung Fung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Boon Chin Heng
- Peking University School of Stomatology, Beijing, China.
| | - Chengfei Zhang
- Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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Poon CH, Wang Y, Fung ML, Zhang C, Lim LW. Rodent Models of Amyloid-Beta Feature of Alzheimer's Disease: Development and Potential Treatment Implications. Aging Dis 2020; 11:1235-1259. [PMID: 33014535 PMCID: PMC7505263 DOI: 10.14336/ad.2019.1026] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 10/26/2019] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder worldwide and causes severe financial and social burdens. Despite much research on the pathogenesis of AD, the neuropathological mechanisms remain obscure and current treatments have proven ineffective. In the past decades, transgenic rodent models have been used to try to unravel this disease, which is crucial for early diagnosis and the assessment of disease-modifying compounds. In this review, we focus on transgenic rodent models used to study amyloid-beta pathology in AD. We also discuss their possible use as promising tools for AD research. There is still no effective treatment for AD and the development of potent therapeutics are urgently needed. Many molecular pathways are susceptible to AD, ranging from neuroinflammation, immune response, and neuroplasticity to neurotrophic factors. Studying these pathways may shed light on AD pathophysiology as well as provide potential targets for the development of more effective treatments. This review discusses the advantages and limitations of these models and their potential therapeutic implications for AD.
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Affiliation(s)
- Chi Him Poon
- 1School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yingyi Wang
- 1School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Man-Lung Fung
- 1School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Chengfei Zhang
- 2Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Lee Wei Lim
- 1School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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Tan SZK, Neoh J, Lawrence AJ, Wu EX, Lim LW. Prelimbic Cortical Stimulation Improves Spatial Memory Through Distinct Patterns of Hippocampal Gene Expression in Aged Rats. Neurotherapeutics 2020; 17:2054-2068. [PMID: 32816221 PMCID: PMC7851284 DOI: 10.1007/s13311-020-00913-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Dementia poses major health challenges worldwide, yet current treatments are faced with issues of efficacy and toxicity. Deep brain stimulation (DBS) is a promising non-pharmacological treatment for dementia, but most DBS studies use young healthy animals, which may not be aetiologically relevant. In this study, we used an aged rat model in which cognitive decline occurs through a natural ageing process. We used a Morris water maze (MWM) to determine the effects of prelimbic cortex (PrL) DBS on memory in aged rats. To investigate the underlying mechanisms of the effects of DBS, we carried out microarray, quantitative PCR analysis, and mass spectrometry to detect gene expression and neurotransmitter changes in the hippocampus. We showed PrL DBS improved the performance in MWM, with related distinct patterns of gene expression involving G protein-coupled receptor pathways. We further found neurotransmitter changes in the dorsal hippocampus, which corroborated and extended the microarray findings. Our results suggest that non-neurogenesis pathways play roles in the effects of DBS. Further studies are needed to investigate the effects of DBS on memory beyond neurogenesis and to consider the highlighted pathways suggested by our data.
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Affiliation(s)
- Shawn Zheng Kai Tan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR China
| | - Joveen Neoh
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR China
| | - Andrew John Lawrence
- Behavioural Neuroscience Division, Florey Institute of Neuroscience and Mental Health, Parkville, VIC Australia
| | - Ed Xuekui Wu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, SAR China
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR China
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Abstract
Background Recent advancements in neuroscientific techniques have allowed us to make huge progress in our understanding of memories, and in turn has paved the way for new memory modification technologies (MMTs) that can modulate memories with a degree of precision, which was not previously possible. With advancements in such techniques, new and critical ethical questions have emerged. Understanding and framing these ethical questions within the current philosophical theories is crucial in order to systematically examine them as we translate these techniques to the clinic. Main body In this paper, we discuss the ethical implications of modern neuroscience techniques that aim to disrupt or enhance memories. We attempt to frame the MMTs in the context of existing ethical philosophical theories to provide a cohesive analysis of the myriad of ethical quagmires that might emerge from such technologies. We argue the application of Aristotle’s Golden Mean and multiple accounts of authenticity are useful in approaching the ethical questions surrounding MMTs. We then propose a framework in which ethical considerations can be systematically examined. Lastly, we provide caveats and considerations for the use of this framework. Overall, we provide a practical approach for the ethical use of MMTs depending on the situation. Conclusion While at face value, our model appears to put severe limitations on the application of MMTs, we are not completely opposed to their use, but rather our framework guides the agent to consider the implications before making any decisions. Most importantly, we argue that the use of MMTs does not reduce the responsibility of the initial decision, and the agent must accept the post-MMT self as the new “true self” regardless of the outcome. As the developmental trajectory of MMTs suggests we are getting closer to practical clinical applications, ethical concerns across a wide range of disciplines need to be addressed to develop best strategies and policies when dealing with MMTs. If this can be achieved, we believe the ethical use of MMTs is not only possible but would also be of tremendous benefit to many people suffering from memory-related mental disorders.
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Affiliation(s)
- Shawn Zheng Kai Tan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong, PR China.
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong, PR China.
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Tan SZK, Du R, Perucho JAU, Chopra SS, Vardhanabhuti V, Lim LW. Dropout in Neural Networks Simulates the Paradoxical Effects of Deep Brain Stimulation on Memory. Front Aging Neurosci 2020; 12:273. [PMID: 33093830 PMCID: PMC7521073 DOI: 10.3389/fnagi.2020.00273] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/10/2020] [Indexed: 12/02/2022] Open
Abstract
Neuromodulation techniques such as deep brain stimulation (DBS) are a promising treatment for memory-related disorders including anxiety, addiction, and dementia. However, the outcomes of such treatments appear to be somewhat paradoxical, in that these techniques can both disrupt and enhance memory even when applied to the same brain target. In this article, we hypothesize that disruption and enhancement of memory through neuromodulation can be explained by the dropout of engram nodes. We used a convolutional neural network (CNN) to classify handwritten digits and letters and applied dropout at different stages to simulate DBS effects on engrams. We showed that dropout applied during training improved the accuracy of prediction, whereas dropout applied during testing dramatically decreased the accuracy of prediction, which mimics enhancement and disruption of memory, respectively. We further showed that transfer learning of neural networks with dropout had increased the accuracy and rate of learning. Dropout during training provided a more robust “skeleton” network and, together with transfer learning, mimicked the effects of chronic DBS on memory. Overall, we showed that the dropout of engram nodes is a possible mechanism by which neuromodulation techniques such as DBS can both disrupt and enhance memory, providing a unique perspective on this paradox.
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Affiliation(s)
- Shawn Zheng Kai Tan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Richard Du
- Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Jose Angelo Udal Perucho
- Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Shauhrat S Chopra
- School of Energy and Environment, City University of Hong Kong, Hong Kong, Hong Kong
| | - Varut Vardhanabhuti
- Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
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Poon CH, Heng BC, Lim LW. New insights on brain-derived neurotrophic factor epigenetics: from depression to memory extinction. Ann N Y Acad Sci 2020; 1484:9-31. [PMID: 32808327 DOI: 10.1111/nyas.14458] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/21/2020] [Accepted: 07/14/2020] [Indexed: 12/14/2022]
Abstract
Advances in characterizing molecular profiles provide valuable insights and opportunities for deciphering the neuropathology of depression. Although abnormal brain-derived neurotrophic factor (BDNF) expression in depression has gained much support from preclinical and clinical research, how it mediates behavioral alterations in the depressed state remains largely obscure. Environmental factors contribute significantly to the onset of depression and produce robust epigenetic changes. Epigenetic regulation of BDNF, as one of the most characterized gene loci in epigenetics, has recently emerged as a target in research on memory and psychiatric disorders. Specifically, epigenetic alterations of BDNF exons are heavily involved in mediating memory functions and antidepressant effects. In this review, we discuss key research on stress-induced depression from both preclinical and clinical studies, which revealed that differential epigenetic regulation of specific BDNF exons is associated with depression pathophysiology. Considering that BDNF has a central role in depression, we argue that memory extinction, an adaptive response to fear exposure, is dependent on BDNF modulation and holds promise as a prospective target for alleviating or treating depression and anxiety disorders.
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Affiliation(s)
- Chi Him Poon
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Boon Chin Heng
- Peking University School of Stomatology, Beijing, China.,Department of Biological Sciences, Sunway University, Selangor, Malaysia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Department of Biological Sciences, Sunway University, Selangor, Malaysia
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