1
|
Huang X, Wang YJ, Xiang Y. Bidirectional communication between brain and visceral white adipose tissue: Its potential impact on Alzheimer's disease. EBioMedicine 2022; 84:104263. [PMID: 36122553 PMCID: PMC9490488 DOI: 10.1016/j.ebiom.2022.104263] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 08/21/2022] [Accepted: 08/24/2022] [Indexed: 11/20/2022] Open
Abstract
A variety of axes between brain and abdominal organs have been reported, but the interaction between brain and visceral white adipose tissue (vWAT) remains unclear. In this review, we summarized human studies on the association between brain and vWAT, and generalized their interaction and the underlying mechanisms according to animal and cell experiments. On that basis, we come up with the concept of the brain-vWAT axis (BVA). Furthermore, we analyzed the potential mechanisms of involvement of BVA in the pathogenesis of Alzheimer's disease (AD), including vWAT-derived fatty acids, immunological properties of vWAT, vWAT-derived retinoic acid and vWAT-regulated insulin resistance. The proposal of BVA may expand our understanding to some extent of how the vWAT impacts on brain health and diseases, and provide a novel approach to study the pathogenesis and treatment strategies of neurodegenerative disorders.
Collapse
|
2
|
Behl T, Kaur D, Sehgal A, Singla RK, Makeen HA, Albratty M, Alhazmi HA, Meraya AM, Bungau S. Therapeutic insights elaborating the potential of retinoids in Alzheimer’s disease. Front Pharmacol 2022; 13:976799. [PMID: 36091826 PMCID: PMC9453874 DOI: 10.3389/fphar.2022.976799] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Alzheimer’s disease (AD) is perceived with various pathophysiological characteristics such oxidative stress, senile plaques, neuroinflammation, altered neurotransmission immunological changes, neurodegenerative pathways, and age-linked alterations. A great deal of studies even now are carried out for comprehensive understanding of pathological processes of AD, though many agents are in clinical trials for the treatment of AD. Retinoids and retinoic acid receptors (RARs) are pertinent to such attributes of the disease. Retinoids support the proper functioning of the immunological pathways, and are very potent immunomodulators. The nervous system relies heavily on retinoic acid signaling. The disruption of retinoid signaling relates to several pathogenic mechanisms in the normal brain. Retinoids play critical functions in the neuronal organization, differentiation, and axonal growth in the normal functioning of the brain. Disturbed retinoic acid signaling causes inflammatory responses, mitochondrial impairment, oxidative stress, and neurodegeneration, leading to Alzheimer’s disease (AD) progression. Retinoids interfere with the production and release of neuroinflammatory chemokines and cytokines which are located to be activated in the pathogenesis of AD. Also, stimulating nuclear retinoid receptors reduces amyloid aggregation, lowers neurodegeneration, and thus restricts Alzheimer’s disease progression in preclinical studies. We outlined the physiology of retinoids in this review, focusing on their possible neuroprotective actions, which will aid in elucidating the critical function of such receptors in AD pathogenesis.
Collapse
Affiliation(s)
- Tapan Behl
- School of Health Sciences, University of Petroleum and Energy Studies, Dehradun, Uttarakhand, India
- *Correspondence: Tapan Behl, ; Simona Bungau,
| | - Dapinder Kaur
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, India
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, India
| | - Rajeev K. Singla
- Institutes for Sytems Genetics, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- iGlobal Research and Publishing Foundation, New Delhi, India
| | - Hafiz A. Makeen
- Pharmacy Practice Research Unit, Clinical Pharmacy Department, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
| | - Mohammed Albratty
- Department of Pharmaceutical Chemistry and Pharmacognosy, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
| | - Hassan A. Alhazmi
- Department of Pharmaceutical Chemistry and Pharmacognosy, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
- Substance Abuse and Toxicology Research Center, Jazan University, Jazan, Saudi Arabia
| | - Abdulkarim M. Meraya
- Pharmacy Practice Research Unit, Department of Clinical Pharmacy, College of Pharmacy, Jazan University, Jazan, Saudi Arabia
| | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, Oradea, Romania
- Doctoral School of Biomedical Sciences, University of Oradea, Oradea, Romania
- *Correspondence: Tapan Behl, ; Simona Bungau,
| |
Collapse
|
3
|
All-trans retinoic acid reduces mammalian target of rapamycin via a Sirtuin1-dependent mechanism in neurons. Neuroreport 2021; 32:975-982. [PMID: 34050114 DOI: 10.1097/wnr.0000000000001672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Neuroinflammation has emerged as a key contributor in the pathogenesis of Alzheimer's disease (AD). Mammalian target of rapamycin (mTOR) is a key regulator of metabolism, cell growth and protein synthesis. And an elevated mTOR activity has been detected in AD-affected brain areas. Previous studies have suggested that all-trans retinoic acid (atRA) and rapamycin (RAPA), an mTOR inhibitor, protect lipopolysaccharide (LPS)-induced neuronal inflammation through inhibiting nuclear import of NFκB. The aim of this study was to test the effects of atRA on mTOR expression. Here we discovered that mTOR and p-mTOR expression are elevated in LPS-treated mice or primary rat neurons, while atRA blocks the mTOR gene upregulation via a SIRT1-dependent mechanism. The results of this study demonstrated that atRA may protect LPS-induced neuronal inflammation through suppressing mTOR signaling.
Collapse
|
4
|
Tomlinson CWE, Cornish KAS, Whiting A, Pohl E. Structure-functional relationship of cellular retinoic acid-binding proteins I and II interacting with natural and synthetic ligands. Acta Crystallogr D Struct Biol 2021; 77:164-175. [PMID: 33559606 PMCID: PMC7869897 DOI: 10.1107/s2059798320015247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 11/16/2020] [Indexed: 11/11/2022] Open
Abstract
A detailed understanding of the interactions between small-molecule ligands and their proposed binding targets is of the utmost importance for modern drug-development programs. Cellular retinoic acid-binding proteins I and II (CRABPI and CRABPII) facilitate a number of vital retinoid signalling pathways in mammalian cells and offer a gateway to manipulation of signalling that could potentially reduce phenotypes in serious diseases, including cancer and neurodegeneration. Although structurally very similar, the two proteins possess distinctly different biological functions, with their signalling influence being exerted through both genomic and nongenomic pathways. In this article, crystal structures are presented of the L29C mutant of Homo sapiens CRABPI in complex with naturally occurring fatty acids (1.64 Å resolution) and with the synthetic retinoid DC645 (2.41 Å resolution), and of CRABPII in complex with the ligands DC479 (1.80 Å resolution) and DC645 (1.71 Å resolution). DC645 and DC479 are two potential drug compounds identified in a recent synthetic retinoid development program. In particular, DC645 has recently been shown to have disease-modifying capabilities in neurodegenerative disease models by activating both genomic and nongenomic signalling pathways. These co-crystal structures demonstrate a canonical binding behaviour akin to that exhibited with all-trans-retinoic acid and help to explain how the compounds are able to exert an influence on part of the retinoid signalling cascade.
Collapse
Affiliation(s)
- Charles W. E. Tomlinson
- Department of Chemistry, Durham University, Lower Mountjoy, South Road, Durham DH1 3LE, United Kingdom
| | - Katy A. S. Cornish
- Department of Chemistry, Durham University, Lower Mountjoy, South Road, Durham DH1 3LE, United Kingdom
| | - Andrew Whiting
- Department of Chemistry, Durham University, Lower Mountjoy, South Road, Durham DH1 3LE, United Kingdom
| | - Ehmke Pohl
- Department of Chemistry, Durham University, Lower Mountjoy, South Road, Durham DH1 3LE, United Kingdom
- Department of Biosciences, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, United Kingdom
| |
Collapse
|
5
|
Khatib T, Chisholm DR, Whiting A, Platt B, McCaffery P. Decay in Retinoic Acid Signaling in Varied Models of Alzheimer's Disease and In-Vitro Test of Novel Retinoic Acid Receptor Ligands (RAR-Ms) to Regulate Protective Genes. J Alzheimers Dis 2020; 73:935-954. [PMID: 31884477 PMCID: PMC7081102 DOI: 10.3233/jad-190931] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2019] [Indexed: 12/22/2022]
Abstract
Retinoic acid has been previously proposed in the treatment of Alzheimer's disease (AD). Here, five transgenic mouse models expressing AD and frontotemporal dementia risk genes (i.e., PLB2APP, PLB2TAU, PLB1Double, PLB1Triple, and PLB4) were used to investigate if consistent alterations exist in multiple elements of the retinoic acid signaling pathway in these models. Many steps of the retinoic acid signaling pathway including binding proteins and metabolic enzymes decline, while the previously reported increase in RBP4 was only consistent at late (6 months) but not early (3 month) ages. The retinoic acid receptors were exceptional in their consistent decline in mRNA and protein with transcript decline of retinoic acid receptors β and γ by 3 months, before significant pathology, suggesting involvement in early stages of disease. Decline in RBP1 transcript may also be an early but not late marker of disease. The decline in the retinoic acid signaling system may therefore be a therapeutic target for AD and frontotemporal dementia. Thus, novel stable retinoic acid receptor modulators (RAR-Ms) activating multiple genomic and non-genomic pathways were probed for therapeutic control of gene expression in rat primary hippocampal and cortical cultures. RAR-Ms promoted the non-amyloidogenic pathway, repressed lipopolysaccharide induced inflammatory genes and induced genes with neurotrophic action. RAR-Ms had diverse effects on gene expression allowing particular RAR-Ms to be selected for maximal therapeutic effect. Overall the results demonstrated the early decline of retinoic acid signaling in AD and frontotemporal dementia models and the activity of stable and potent alternatives to retinoic acid as potential therapeutics.
Collapse
Affiliation(s)
- Thabat Khatib
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK
| | - David R. Chisholm
- Department of Chemistry, Durham University, Science Laboratories, South Road, Durham, UK
| | - Andrew Whiting
- Department of Chemistry, Durham University, Science Laboratories, South Road, Durham, UK
| | - Bettina Platt
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK
| | - Peter McCaffery
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK
| |
Collapse
|
6
|
Sharma A, Kumar Y. Nature's Derivative(s) as Alternative Anti-Alzheimer's Disease Treatments. J Alzheimers Dis Rep 2019; 3:279-297. [PMID: 31867567 PMCID: PMC6918879 DOI: 10.3233/adr-190137] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 12/15/2022] Open
Abstract
Alzheimer's disease (AD), the 'Plague of Twenty-First Century,' is a crippling neurodegenerative disease that affects a majority of the older population globally. By 2050, the incidence of AD is expected to rise to 135 million, while no treatment(s) that can reverse or control the progression of AD are currently available. The treatment(s) in use are limited in their ability to manage the symptoms or slow the progression of the disease and can lead to some severe side effects. The overall care is economically burdensome for the affected individuals as well as the caretakers or family members. Thus, there is a pressing need to identify and develop much safer alternative therapies that can better manage AD. This review discusses a multitude of such treatments borrowed from Ayurveda, traditional Chinese practices, meditation, and exercising for AD treatment. These therapies are in practice since ancient times and reported to be beneficial as anti-AD therapies. Ayurvedic drugs like turmeric, Brahmi, Ashwagandha, etc., management of stress by meditation, regular exercising, and acupuncture have been reported to be efficient in their anti-AD usage. Besides, a combination of vitamins and natural dietary intakes is likely to play a significant role in combating AD. We conclude that the use of such alternative strategies will be a stepping-stone in preventing, treating, curing, or managing the disease.
Collapse
Affiliation(s)
- Anuja Sharma
- Department of Biological Sciences and Engineering (BSE), Netaji Subhas University of Technology (NSUT), Formerly Netaji Subhas Institute of Technology (NSIT), Azad Hind Fauz Marg, New Delhi, India
| | - Yatender Kumar
- Department of Biological Sciences and Engineering (BSE), Netaji Subhas University of Technology (NSUT), Formerly Netaji Subhas Institute of Technology (NSIT), Azad Hind Fauz Marg, New Delhi, India
| |
Collapse
|
7
|
Xin Y, Diling C, Jian Y, Ting L, Guoyan H, Hualun L, Xiaocui T, Guoxiao L, Ou S, Chaoqun Z, Jun Z, Yizhen X. Effects of Oligosaccharides From Morinda officinalis on Gut Microbiota and Metabolome of APP/PS1 Transgenic Mice. Front Neurol 2018; 9:412. [PMID: 29962999 PMCID: PMC6013575 DOI: 10.3389/fneur.2018.00412] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/18/2018] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD), a progressive neurodegenerative disorder, lacks preclinical diagnostic biomarkers and therapeutic drugs. Thus, earlier intervention in AD is a top priority. Studies have shown that the gut microbiota influences central nervous system disorders and that prebiotics can improve the cognition of hosts with AD, but these effects are not well understood. Preliminary research has shown that oligosaccharides from Morinda officinalis (OMO) are a useful prebiotic and cause substantial memory improvements in animal models of AD; however, the mechanism is still unclear. Therefore, this study was conducted to investigate whether OMO are clinically effective in alleviating AD by improving gut microbiota. OMO were administered to APP/PS1 transgenic mice, and potential clinical biomarkers of AD were identified with metabolomics and bioinformatics. Behavioral experiments demonstrated that OMO significantly ameliorated the memory of the AD animal model. Histological changes indicated that OMO ameliorated brain tissue swelling and neuronal apoptosis and downregulated the expression of the intracellular AD marker Aβ1−42. 16S rRNA sequencing analyses indicated that OMO maintained the diversity and stability of the microbial community. The data also indicated that OMO are an efficacious prebiotic in an animal model of AD, regulating the composition and metabolism of the gut microbiota. A serum metabolomics assay was performed using UHPLC-LTQ Orbitrap mass spectrometry to delineate the metabolic changes and potential early biomarkers in APP/PS1 transgenic mice. Multivariate statistical analysis showed that 14 metabolites were significantly upregulated, and 8 metabolites were downregulated in the model animals compared to the normal controls. Thus, key metabolites represent early indicators of the development of AD. Overall, we report a drug and signaling pathway with therapeutic potential, including proteins associated with cognitive deficits in normal mice or gene mutations that cause AD.
Collapse
Affiliation(s)
- Yang Xin
- Department of Pharmacy, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,The Fifth Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Chen Diling
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Yang Jian
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Liu Ting
- The Fifth Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Hu Guoyan
- The Fifth Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Liang Hualun
- Department of Pharmacy, The Second Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Tang Xiaocui
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Lai Guoxiao
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China.,College of Pharmacy, Guangxi University of Traditional Chinese Medicine, Nanning, China
| | - Shuai Ou
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Zheng Chaoqun
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Zhao Jun
- Department of Obstetrics, Guangdong Women and Children Hospital, Guangzhou, China
| | - Xie Yizhen
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| |
Collapse
|
8
|
Mohammadzadeh Honarvar N, Saedisomeolia A, Abdolahi M, Shayeganrad A, Taheri Sangsari G, Hassanzadeh Rad B, Muench G. Molecular Anti-inflammatory Mechanisms of Retinoids and Carotenoids in Alzheimer's Disease: a Review of Current Evidence. J Mol Neurosci 2016; 61:289-304. [PMID: 27864661 DOI: 10.1007/s12031-016-0857-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 10/21/2016] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is considered as one of the most prevalent neurodegenerative disorders characterized by progressive loss of mental function and ability to learn. AD is a multifactorial disorder. Various hypotheses are suggested for the pathophysiology of AD including "Aβ hypothesis," "tau hypothesis," and "cholinergic hypothesis." Recently, it has been demonstrated that neuroinflammation is involved in the pathogenesis of AD. Neuroinflammation causes synaptic dysfunction and neuronal death within the brain. Excessive production of pro-inflammatory mediators induces Aβ peptide production/accumulation and hyperphosphorylated tau generating inflammatory molecules and cytokines. These inflammatory molecules disrupt blood-brain barrier integrity and increase the production of Aβ42 oligomers. Retinoids and carotenoids are potent antioxidants and anti-inflammatory agents having neuroprotective properties. They are able to prevent disease progression through several mechanisms such as suppression of Aβ peptide production/accumulation, oxidative stress, and pro-inflammatory mediator's secretion as well as improvement of cognitive performance. These observations, therefore, confirm the neuroprotective role of retinoids and carotenoids through multiple pathways. Therefore, the administration of these nutrients is considered as a promising approach to the prevention and/or treatment of AD in the future. The aim of this review is to present existing evidences regarding the beneficial effects of retinoids and carotenoids on AD's risk and outcomes, seeking the mechanism of their action.
Collapse
Affiliation(s)
- Niyaz Mohammadzadeh Honarvar
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Saedisomeolia
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. .,Department of Pharmacology, School of Medicine, Western Sydney University, NSW, Australia. .,School of Molecular Bioscience, Charles Perkins Centre, University of Sydney, NSW, Australia.
| | - Mina Abdolahi
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Amir Shayeganrad
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | - Gerald Muench
- Department of Pharmacology, School of Medicine, Western Sydney University, NSW, Australia
| |
Collapse
|
9
|
Chakrabarti M, McDonald AJ, Will Reed J, Moss MA, Das BC, Ray SK. Molecular Signaling Mechanisms of Natural and Synthetic Retinoids for Inhibition of Pathogenesis in Alzheimer's Disease. J Alzheimers Dis 2016; 50:335-52. [PMID: 26682679 DOI: 10.3233/jad-150450] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Retinoids, which are vitamin A derivatives, interact through retinoic acid receptors (RARs) and retinoid X receptors (RXRs) and have profound effects on several physiological and pathological processes in the brain. The presence of retinoic acid signaling is extensively detected in the adult central nervous system, including the amygdala, cortex, hypothalamus, hippocampus, and other brain areas. Retinoids are primarily involved in neural patterning, differentiation, and axon outgrowth. Retinoids also play a key role in the preservation of the differentiated state of adult neurons. Impairment in retinoic acid signaling can result in neurodegeneration and progression of Alzheimer's disease (AD). Recent studies demonstrated severe deficiencies in spatial learning and memory in mice during retinoic acid (vitamin A) deprivation indicating its significance in preserving memory function. Defective cholinergic neurotransmission plays an important role in cognitive deficits in AD. All-trans retinoic acid is known to enhance the expression and activity of choline acetyltransferase in neuronal cell lines. Activation of RAR and RXR is also known to impede the pathogenesis of AD in mice by inhibiting accumulation of amyloids. In addition, retinoids have been shown to inhibit the expression of chemokines and pro-inflammatory cytokines in microglia and astrocytes, which are activated in AD. In this review article, we have described the chemistry and molecular signaling mechanisms of natural and synthetic retinoids and current understandings of their therapeutic potentials in prevention of AD pathology.
Collapse
Affiliation(s)
- Mrinmay Chakrabarti
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Alexander J McDonald
- Department of Pharmacology, Physiology, and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - J Will Reed
- Department of Chemical Engineering, University of South Carolina, Columbia, SC, USA
| | - Melissa A Moss
- Department of Chemical Engineering, University of South Carolina, Columbia, SC, USA
| | - Bhaskar C Das
- Division of Hematology and Oncology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Swapan K Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA
| |
Collapse
|
10
|
A tuberous sclerosis complex signalling node at the peroxisome regulates mTORC1 and autophagy in response to ROS. Nat Cell Biol 2013; 15:1186-96. [PMID: 23955302 PMCID: PMC3789865 DOI: 10.1038/ncb2822] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 07/10/2013] [Indexed: 12/12/2022]
Abstract
Subcellular localization is emerging as an important mechanism for mTORC1 regulation. We report that the tuberous sclerosis complex (TSC) signaling node, TSC1, TSC2 and Rheb, localizes to peroxisomes, where it regulates mTORC1 in response to reactive oxygen species (ROS). TSC1 and TSC2 were bound by PEX19 and PEX5, respectively, and peroxisome-localized TSC functioned as a Rheb GAP to suppress mTORC1 and induce autophagy. Naturally occurring pathogenic mutations in TSC2 decreased PEX5 binding, abrogated peroxisome localization, Rheb GAP activity, and suppression of mTORC1 by ROS. Cells lacking peroxisomes were deficient in mTORC1 repression by ROS and peroxisome-localization deficient TSC2 mutants caused polarity defects and formation of multiple axons in neurons. These data identify a role for TSC in responding to ROS at the peroxisome, and identify the peroxisome as a signaling organelle involved in regulation of mTORC1.
Collapse
|
11
|
Shearer KD, Stoney PN, Morgan PJ, McCaffery PJ. A vitamin for the brain. Trends Neurosci 2012; 35:733-41. [PMID: 22959670 DOI: 10.1016/j.tins.2012.08.005] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Revised: 08/14/2012] [Accepted: 08/14/2012] [Indexed: 11/25/2022]
Abstract
In the central nervous system (CNS) the function of retinoic acid, the active metabolite of vitamin A, is best understood from its action in guiding embryonic development; as development comes to completion, retinoic acid signaling declines. However, it is increasingly recognized that this signaling mechanism does not disappear in the adult brain but becomes more regionally focused and takes on new roles. These functions are often tied to processes of neural plasticity whether in the hippocampus, through homeostatic neural plasticity, the olfactory bulb or the hypothalamus. The role of retinoic acid in the control of plastic processes has led to suggestions of its involvement in neural disorders, both degenerative and psychiatric. This review presents a snapshot of developments in these areas over recent years.
Collapse
Affiliation(s)
- Kirsty D Shearer
- Institute of Medical Sciences, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK
| | | | | | | |
Collapse
|
12
|
Abstract
The deposition of amyloid β-protein (Aβ) in the brain is an invariant feature of Alzheimer's disease (AD). Vitamin A, which has been traditionally considered an anti-oxidant compound, plays a role in maintaining higher function in the central nervous system. Plasma or cerebrospinal fluid concentrations of vitamin A and β-carotene have been reported to be lower in AD patients, and these vitamins have been clinically shown to slow the progression of dementia. Vitamin A (retinol, retinal and retinoic acid) and β-carotene have been shown in in vitro studies to inhibit the formation, extension and destabilizing effects of β-amyloid fibrils. Recently, the inhibition of the oligomerization of Aβ has been suggested as a possible therapeutic target for the treatment of AD. We have recently shown the inhibitory effects of vitamin A and β-carotene on the oligomerization of Aβ40 and Aβ42 in vitro. In previous in vivo studies, intraperitoneal injections of vitamin A decreased brain Aβ deposition and tau phosphorylation in transgenic mouse models of AD, attenuated neuronal degeneration, and improved spatial learning and memory. Thus, vitamin A and β-carotene could be key molecules for the prevention and therapy of AD.
Collapse
Affiliation(s)
- Kenjiro Ono
- Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
| | | |
Collapse
|
13
|
Obulesu M, Dowlathabad MR, Bramhachari PV. Carotenoids and Alzheimer's disease: an insight into therapeutic role of retinoids in animal models. Neurochem Int 2011; 59:535-41. [PMID: 21672580 DOI: 10.1016/j.neuint.2011.04.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 03/16/2011] [Accepted: 04/20/2011] [Indexed: 01/09/2023]
Abstract
Carotenoids play a pivotal role in prevention of many degenerative diseases mediated by oxidative stress including neurodegenerative diseases like Alzheimer's Disease (AD). The involvement of retinoids in physiology, AD pathology and their therapeutic role in vitro and in vivo has been extensively studied. This review focuses on the role of carotenoids like retinoic acid (RA), all trans retinoic acid (ATRA), lycopene and β-carotene in prevention of AD symptoms primarily through inhibition of amyloid beta (Aβ) formation, deposition and fibril formation either by reducing the levels of p35 or inhibiting corresponding enzymes. The role of antioxidant micronutrients in prevention or delaying of AD symptoms has been included. This study emphasizes the dietary supplementation of carotenoids to combat AD and warrants further studies on animal models to unravel their mechanism of neuroprotection.
Collapse
Affiliation(s)
- M Obulesu
- Department of Biotechnology, Rayalaseema University, Kurnool, Andhra Pradesh, India.
| | | | | |
Collapse
|
14
|
Sakamoto K, Hiraiwa M, Saito M, Nakahara T, Sato Y, Nagao T, Ishii K. Protective effect of all-trans retinoic acid on NMDA-induced neuronal cell death in rat retina. Eur J Pharmacol 2010; 635:56-61. [DOI: 10.1016/j.ejphar.2010.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 01/30/2010] [Accepted: 03/03/2010] [Indexed: 12/17/2022]
|
15
|
Lee HP, Casadesus G, Zhu X, Lee HG, Perry G, Smith MA, Gustaw-Rothenberg K, Lerner A. All-trans retinoic acid as a novel therapeutic strategy for Alzheimer's disease. Expert Rev Neurother 2010; 9:1615-21. [PMID: 19903021 DOI: 10.1586/ern.09.86] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Retinoic acid, an essential factor derived from vitamin A, has been shown to have a variety of functions including roles as an antioxidant and in cellular differentiation. Since oxidative stress and dedifferentiation of neurons appear to be common pathological elements of a number of neurodegenerative disorders, we speculated that retinoic acid may offer therapeutic promise. In this vein, recent compelling evidence indicates a role of retinoic acid in cognitive activities and anti-amyloidogenic properties. Here, we review the actions of retinoic acid that indicate that it may have therapeutic properties ideally served for the treatment of neurodegenerative diseases such as Alzheimer's disease.
Collapse
Affiliation(s)
- Hyun-Pil Lee
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA.
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Hahm BJ, Min SU, Yoon MY, Shin YW, Kim JS, Jung JY, Suh DH. Changes of psychiatric parameters and their relationships by oral isotretinoin in acne patients. J Dermatol 2009; 36:255-61. [PMID: 19382995 DOI: 10.1111/j.1346-8138.2009.00635.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Oral isotretinoin is a highly effective agent for the treatment of moderate to severe acne, but ever since oral isotretinoin was introduced as a modality for acne, the relationship between oral isotretinoin therapy and psychiatric problems, especially depression, has been controversial. The purposes of this study were to know the acute effects of oral isotretinoin therapy on psychiatric symptoms and to investigate the relationships among them, which have not been reported in the published work. This cohort study included 38 acne patients who started oral isotretinoin therapy. Individual patients were examined before administering oral isotretinoin and 2 and 8 weeks after commencement. Acne severity was graded using the Leeds revised acne grading system. Acute psychiatric effects of oral isotretinoin were assessed using a questionnaire authorized by two psychiatrists. This questionnaire included assessments of acne-related quality of life (Assessment of the Psychological and Social Effects of Acne [APSEA]), depression (Beck's depression inventory [BDI]), anxiety (Beck's anxiety inventory [BAI]) and psychopathology (Symptomchecklist-90-revised [SCL-90-R]). Acne grading and APSEA showed similar change patterns. Both improved after 8 weeks of oral isotretinoin treatment. On the other hand, the severity of depression decreased after 2 weeks of treatment. A significant correlation was found between BDI and APSEA, but no correlation was found between BDI and acne grade. These results indicate that oral isotretinoin therapy alleviates depressive symptoms. Improvements in depression are directly related to acne-related life quality improvements rather than to improvement in acne grade.
Collapse
Affiliation(s)
- Bong Jin Hahm
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
| | | | | | | | | | | | | |
Collapse
|
17
|
Koryakina A, Aeberhard J, Kiefer S, Hamburger M, Küenzi P. Regulation of secretases by all-trans-retinoic acid. FEBS J 2009; 276:2645-55. [DOI: 10.1111/j.1742-4658.2009.06992.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
18
|
Robles A. Pharmacological Treatment of Alzheimer's Disease: Is it Progressing Adequately? Open Neurol J 2009; 3:27-44. [PMID: 19461897 PMCID: PMC2684708 DOI: 10.2174/1874205x00903010027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 12/26/2008] [Accepted: 01/02/2009] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Between 1993 and 2000 four acetylcholinesterase inhibitors were marketed as a symptomatic treatment for Alzheimer's disease (AD), as well as memantine in 2003. Current research is focused on finding drugs that favorably modify the course of the disease. However, their entrance into the market does not seem to be imminent. RESEARCH DEVELOPMENT The aim of AD research is to find substances that inhibit certain elements of the AD pathogenic chain (beta- and gamma-secretase inhibitors, alpha-secretase stimulants, beta-amyloid aggregability reducers or disaggregation and elimination inductors, as well as tau-hyperphosphorylation, glutamate excitotoxicity, oxidative stress and mitochondrial damage reducers, among other action mechanisms). Demonstrating a disease's retarding effect demands longer trials than those necessary to ascertain symptomatic improvement. Besides, a high number of patients (thousands of them) is necessary, all of which turns out to be difficult and costly. Furthermore, it would be necessary to count on diagnosis and progression markers in the disease's pre-clinical stage, markers for specific phenotypes, as well as high-selectivity molecules acting only where necessary. In order to compensate these difficulties, drugs acting on several defects of the pathogenic chain or showing both symptomatic and neuroprotective action simultaneously are being researched. CONCLUSIONS There are multiple molecules used in research to modify AD progression. Although it turns out to be difficult to obtain drugs with sufficient efficacy so that their marketing is approved, if they were achieved they would lead to a reduction of AD prevalence.
Collapse
Affiliation(s)
- Alfredo Robles
- La Rosaleda Hospital, Santiago León de Caracas street, no. 1, 15706 – Santiago de Compostela, Spain
| |
Collapse
|
19
|
Ghenimi N, Beauvieux MC, Biran M, Pallet V, Higueret P, Gallis JL. Vitamin A deficiency in rats induces anatomic and metabolic changes comparable with those of neurodegenerative disorders. J Nutr 2009; 139:696-702. [PMID: 19193816 DOI: 10.3945/jn.108.102988] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Anatomic and metabolic changes in central nervous system induced by 14 wk of vitamin A deprivation (VAD) were monitored and quantified in rats. In vivo brain magnetic resonance imaging (4.7T) was performed at 5, 7, 9, 11, and 14 wk of each diet after weaning in the following: 1) VAD group; 2) control pair-fed group; and 3) control group that consumed the diet ad libitum (1.15 microg retinol/g diet). After 14 wk, high-resolution magic angle spinning proton NMR spectroscopy (11.7T) was performed on small samples of cortex, hippocampus, and striatum. Serum retinol concentrations remained stable and cerebral volume (CV) increased as a linear function of body weight in the ad libitum group (R(2) = 0.78; P = 0.047) and pair-fed controls (R(2) = 0.78; P = 0.046). In VAD rats, retinol decreased from the onset of deprivation (2.2 +/- 0.14 micromol/L) to reach 0.3 +/- 0.13 micromol/L at wk 5, followed by a stopping of body weight gain from wk 7. In VAD rats, the CV decreased from wk 5 and reached a value 11% lower than that of the control group (P < 0.001) at wk 14 and was correlated with retinol status (R(2) = 0.99; P = 0.002). The VAD hippocampal volume decreased beginning at wk 9 and was 22% lower than that of the control group at wk 14 (P < 0.001). Compared with the control, VAD led to lower N acetyl aspartate:creatine+phosphocreatine (Cr) in cortex (-36%), striatum (-22%), and hippocampus (-19%) and higher myoinositol:Cr in cortex (+127%) and striatum (+150%). VAD induced anatomic and metabolic changes comparable to those associated with neurodegenerative disorders. By wk 7 of deprivation, the slowing in cerebral growth that correlated with the retinol level could be considered as a predictive marker of brain disorders, confirmed by metabolic data from VAD rats after 14 wk.
Collapse
Affiliation(s)
- Nadirah Ghenimi
- Centre de Résonance Magnétique des Systèmes Biologiques, Unité Mixte de Recherche 5536 Centre National de Recherche Scientifique-Université Bordeaux 2, F-33076 Bordeaux Cedex, France
| | | | | | | | | | | |
Collapse
|
20
|
Retinoic acid attenuates beta-amyloid deposition and rescues memory deficits in an Alzheimer's disease transgenic mouse model. J Neurosci 2008; 28:11622-34. [PMID: 18987198 DOI: 10.1523/jneurosci.3153-08.2008] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Recent studies have revealed that disruption of vitamin A signaling observed in Alzheimer's disease (AD) leads to beta-amyloid (Abeta) accumulation and memory deficits in rodents. The aim of the present study was to evaluate the therapeutic effect of all-trans retinoic acid (ATRA), an active metabolite of vitamin A, on the neuropathology and deficits of spatial learning and memory in amyloid precursor protein (APP) and presenilin 1 (PS1) double-transgenic mice, a well established AD mouse model. Here we report a robust decrease in brain Abeta deposition and tau phosphorylation in the blinded study of APP/PS1 transgenic mice treated intraperitoneally for 8 weeks with ATRA (20 mg/kg, three times weekly, initiated when the mice were 5 months old). This was accompanied by a significant decrease in the APP phosphorylation and processing. The activity of cyclin-dependent kinase 5, a major kinase involved in both APP and tau phosphorylation, was markedly downregulated by ATRA treatment. The ATRA-treated APP/PS1 mice showed decreased activation of microglia and astrocytes, attenuated neuronal degeneration, and improved spatial learning and memory compared with the vehicle-treated APP/PS1 mice. These results support ATRA as an effective therapeutic agent for the prevention and treatment of AD.
Collapse
|
21
|
Isotretinoin (13-cis-retinoic acid) alters learning and memory, but not anxiety-like behavior, in the adult rat. Pharmacol Biochem Behav 2008; 91:243-51. [DOI: 10.1016/j.pbb.2008.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Revised: 08/02/2008] [Accepted: 08/06/2008] [Indexed: 11/18/2022]
|
22
|
Maden M. Retinoic acid in the development, regeneration and maintenance of the nervous system. Nat Rev Neurosci 2007; 8:755-65. [PMID: 17882253 DOI: 10.1038/nrn2212] [Citation(s) in RCA: 619] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Retinoic acid (RA) is involved in the induction of neural differentiation, motor axon outgrowth and neural patterning. Like other developmental molecules, RA continues to play a role after development has been completed. Elevated RA signalling in the adult triggers axon outgrowth and, consequently, nerve regeneration. RA is also involved in the maintenance of the differentiated state of adult neurons, and disruption of RA signalling in the adult leads to the degeneration of motor neurons (motor neuron disease), the development of Alzheimer's disease and, possibly, the development of Parkinson's disease. The data described here strongly suggest that RA could be used as a therapeutic molecule for the induction of axon regeneration and the treatment of neurodegeneration.
Collapse
Affiliation(s)
- Malcolm Maden
- MRC Centre for Developmental Neurobiology, fourth floor New Hunt's House, Guy's Campus, King's College London, London, SE1 1UL, UK.
| |
Collapse
|
23
|
Shinozaki Y, Sato Y, Koizumi S, Ohno Y, Nagao T, Inoue K. Retinoic acids acting through retinoid receptors protect hippocampal neurons from oxygen-glucose deprivation-mediated cell death by inhibition of c-jun-N-terminal kinase and p38 mitogen-activated protein kinase. Neuroscience 2007; 147:153-63. [PMID: 17521827 DOI: 10.1016/j.neuroscience.2007.04.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 04/16/2007] [Accepted: 04/17/2007] [Indexed: 01/25/2023]
Abstract
Retinoic acids (RAs), including all-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA), play fundamental roles in a variety of physiological events in vertebrates, through their specific nuclear receptors: retinoic acid receptor (RAR) and retinoid X receptor (RXR). Despite the physiological importance of RA, their functional significance under pathological conditions is not well understood. We examined the effect of ATRA on oxygen/glucose-deprivation/reperfusion (OGD/Rep)-induced neuronal damage in cultured rat hippocampal slices, and found that ATRA significantly reduced neuronal death. The cytoprotective effect of ATRA was observed not only in cornu ammonis (CA) 1 but also in CA2 and dentate gyrus (DG), and was attenuated by selective antagonists for RAR or RXR. By contrast, in the CA3 region, no protective effects of ATRA were observed. The OGD/Rep also increased phosphorylated forms of c-jun-N-terminal kinase (P-JNK) and p38 (P-p38) in hippocampus, and specific inhibitors for these kinases protected neurons. ATRA prevented the increases in P-JNK and P-p38 after OGD/Rep, as well as the decrease in NeuN and its shrinkage, all of which were inhibited by antagonists for RAR or RXR. These findings suggest that the ATRA signaling via retinoid receptors results in the inhibition of JNK and p38 activation, leading to the protection of neurons against OGD/Rep-induced damage in the rat hippocampus.
Collapse
Affiliation(s)
- Y Shinozaki
- Division of Pharmacology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya, Tokyo 158-8501, Japan
| | | | | | | | | | | |
Collapse
|
24
|
Ono K, Yamada M. Vitamin A potently destabilizes preformed α-synuclein fibrils in vitro: Implications for Lewy body diseases. Neurobiol Dis 2007; 25:446-54. [PMID: 17169566 DOI: 10.1016/j.nbd.2006.10.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2006] [Revised: 10/10/2006] [Accepted: 10/19/2006] [Indexed: 12/25/2022] Open
Abstract
Alpha-synuclein (alphaS) is the major component of the filamentous inclusions that constitute defining characteristics of Lewy body diseases (LBD) and multiple system atrophy (MSA). Clinically, antioxidant vitamins, such as vitamin E and the vitamin-like substance coenzyme Q10, have been used in the treatment of LBD with some efficacy. Using fluorescence spectroscopy with thioflavin S, electron microscopy and atomic force microscopy, here we examined the effects of ten antioxidant vitamins and vitamin-like substances, vitamin A (retinol, retinal and retinoic acid), beta-carotene, vitamins B2, B6, C, E, coenzyme Q10 and alpha-lipoic acid, on the formation of alphaS fibrils (falphaS) and on preformed falphaS. Among them, vitamin A, beta-carotene and coenzyme Q10 dose-dependently inhibited the formation of falphaS. Moreover, they also dose-dependently destabilized preformed falphaS. With such potent anti-fibrillogenic as well as fibril-destabilizing activities, these compounds could be useful in the treatment and prevention of LBD and MSA.
Collapse
Affiliation(s)
- Kenjiro Ono
- Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa 920-8640, Japan
| | | |
Collapse
|
25
|
Abstract
Neurotoxins represent unique chemical tools, providing a means to 1) gain insight into cellular mechanisms of apopotosis and necrosis, 2) achieve a morphological template for studies otherwise unattainable, 3) specifically produce a singular phenotype of denervation, and 4) provide the starting point to delve into processes and mechanisms of nerve regeneration and sprouting. There are many other notable uses of neurotoxins in neuroscience research, and ever more being discovered each year. The objective of this review paper is to highlight the broad areas of neuroscience in which neurotoxins and neurotoxicity mechanism come into play. This shifts the focus away from neurotoxins per se, and onto the major problems under study today. Neurotoxins broadly defined are used to explore neurodegenerative disorders, psychiatric disorders and substance use disorders. Neurotoxic mechanisms relating to protein aggregates are indigenous to Alzheimer disease, Parkinson's disease. NeuroAIDS is a disorder in which microglia and macrophages have enormous import. The gap between the immune system and nervous system has been bridged, as neuroinflammation is now considered to be part of the neurodegenerative process. Related mechanisms now arise in the process of neurogenesis. Accordingly, the entire spectrum of neuroscience is within the purview of neurotoxins and neurotoxicity mechanisms. Highlights on discoveries in the areas noted, and on selective neurotoxins, are included, mainly from the past 2 to 3 years.
Collapse
Affiliation(s)
- Juan Segura-Aguilar
- Molecular and Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, Casilla 70000, Santiago, Chile.
| | | |
Collapse
|
26
|
Husson M, Enderlin V, Delacourte A, Ghenimi N, Alfos S, Pallet V, Higueret P. Retinoic acid normalizes nuclear receptor mediated hypo-expression of proteins involved in β-amyloid deposits in the cerebral cortex of vitamin A deprived rats. Neurobiol Dis 2006; 23:1-10. [PMID: 16531051 DOI: 10.1016/j.nbd.2006.01.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Revised: 01/19/2006] [Accepted: 01/27/2006] [Indexed: 11/26/2022] Open
Abstract
Recent data have revealed that disruption of vitamin A signaling observed in Alzheimer's disease (AD) leads to a deposition of beta-amyloid (Abeta). The aim of this study was to precise the role of vitamin A and its nuclear receptors (RAR) in the processes leading to the Abeta deposits. Thus, the effect of vitamin A depletion and subsequent administration of retinoic acid (RA, the active metabolite of vitamin A) on the expression of RARbeta, and of proteins involved in amyloidogenic pathway, e.g., amyloid precursor protein (APP), beta-secretase enzyme (BACE), and APP carboxy-terminal fragment (APP-CTF) was examined in the whole brain, hippocampus, striatum, and cerebral cortex of rats. Rats fed a vitamin A-deprived diet for 13 weeks exhibited decreased amount of RARbeta, APP695, BACE, and of APP-CTF in the whole brain and in the cerebral cortex. Administration of RA is able to restore all expression. The results suggest that fine regulation of vitamin A mediated gene expression seems fundamental for the regulation of APP processing.
Collapse
Affiliation(s)
- Marianne Husson
- Unité de Nutrition et Signalisation Cellulaire (E.A. MENRT; USC INRA) ISTAB, Université Bordeaux 1, Avenue des Facultés, 33405 Talence cedex, France
| | | | | | | | | | | | | |
Collapse
|
27
|
Goodman AB. Retinoid receptors, transporters, and metabolizers as therapeutic targets in late onset Alzheimer disease. J Cell Physiol 2006; 209:598-603. [PMID: 17001693 DOI: 10.1002/jcp.20784] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Vitamin A (retinoid) is required in the adult brain to enable cognition, learning, and memory. While brain levels of retinoid diminish over the course of normal ageing, retinoid deficit is greater in late onset Alzheimer disease (LOAD) brains than in normal-aged controls. This paper reviews recent evidence supporting these statements and further suggests that genes necessary for the synthesis, transport and function of retinoid to and within the ageing brain are appropriate targets for treatment of LOAD. These genes tend to be clustered with genes that have been proposed as candidates in LOAD, are found at chromosomal regions linked to LOAD, and suggest the possibility of an overall coordinated regulation. This phenomenon is termed Chromeron and is analogous to the operon mechanism observed in prokaryotes. Suggested treatment targets are the retinoic-acid inactivating enzymes (CYP26)s, the retinol binding and transport proteins, retinol-binding protein (RBP)4 and transthyretin (TTR), and the retinoid receptors. TTR as a LOAD target is the subject of active investigation. The retinoid receptors and the retinoid-inactivating enzymes have previously been proposed as targets. This is the first report to suggest that RBP4 is an amenable treatment target in LOAD. RBP4 is elevated in type-2 diabetes and obesity, conditions associated with increased risk for LOAD. Fenretinide, a novel synthetic retinoic acid (RA) analog lowers RBP4 in glucose intolerant obese mice. The feasibility of using fenretinide either as an adjunct to present LOAD therapies, or on its own as an early prevention strategy should be determined.
Collapse
Affiliation(s)
- Ann B Goodman
- The Massachusetts Mental Health Center Academic Division of Public Psychiatry, Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|