101
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Morello M, Landel V, Lacassagne E, Baranger K, Annweiler C, Féron F, Millet P. Vitamin D Improves Neurogenesis and Cognition in a Mouse Model of Alzheimer's Disease. Mol Neurobiol 2018; 55:6463-6479. [PMID: 29318446 PMCID: PMC6061182 DOI: 10.1007/s12035-017-0839-1] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/12/2017] [Indexed: 12/11/2022]
Abstract
The impairment of hippocampal neurogenesis at the early stages of Alzheimer’s disease (AD) is believed to support early cognitive decline. Converging studies sustain the idea that vitamin D might be linked to the pathophysiology of AD and to hippocampal neurogenesis. Nothing being known about the effects of vitamin D on hippocampal neurogenesis in AD, we assessed them in a mouse model of AD. In a previous study, we observed that dietary vitamin D supplementation in female AD-like mice reduced cognitive decline only when delivered during the symptomatic phase. With these data in hand, we wondered whether the consequences of vitamin D administration on hippocampal neurogenesis are stage-dependent. Male wild-type and transgenic AD-like mice (5XFAD model) were fed with a diet containing either no vitamin D (0VD) or a normal dose of vitamin D (NVD) or a high dose of vitamin D (HVD), from month 1 to month 6 (preventive arm) or from month 4 to month 9 (curative arm). Working memory was assessed using the Y-maze, while amyloid burden, astrocytosis, and neurogenesis were quantified using immunohistochemistry. In parallel, the effects of vitamin D on proliferation and differentiation were assayed on primary cultures of murine neural progenitor cells. Improved working memory and neurogenesis were observed when high vitamin D supplementation was administered during the early phases of the disease, while a normal dose of vitamin D increased neurogenesis during the late phases. Conversely, an early hypovitaminosis D increased the number of amyloid plaques in AD mice while a late hypovitaminosis D impaired neurogenesis in AD and WT mice. The observed in vivo vitamin D-associated increased neurogenesis was partially substantiated by an augmented in vitro proliferation but not an increased differentiation of neural progenitors into neurons. Finally, a sexual dimorphism was observed. Vitamin D supplementation improved the working memory of males and females, when delivered during the pre-symptomatic and symptomatic phases, respectively. Our study establishes that (i) neurogenesis is improved by vitamin D in a male mouse model of AD, in a time-dependent manner, and (ii) cognition is enhanced in a gender-associated way. Additional pre-clinical studies are required to further understand the gender- and time-specific mechanisms of action of vitamin D in AD. This may lead to an adaptation of vitamin D supplementation in relation to patient’s gender and age as well as to the stage of the disease.
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Affiliation(s)
- Maria Morello
- Aix Marseille Univ, CNRS, NICN, Marseille, France.,Clinical Biochemistry, Department of Experimental Medicine and Surgery, Faculty of Medicine, University Hospital of Tor Vergata, Rome, Italy.,Division of Clinical Nutrition and Nutrigenomics, Department of Biomedicine and Prevention Faculty of Medicine, University of Tor Vergata, Rome, Italy
| | | | | | | | - Cedric Annweiler
- Department of Neurosciences and Aging, Division of Geriatric Medicine, Angers University Hospital, Angers University Memory Clinic, Research Center on Autonomy and Longevity, UPRES EA 4638, University of Angers, UNAM, Angers, France.,Robarts Research Institute, Department of Medical Biophysics, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
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102
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Castillo E, Leon J, Mazzei G, Abolhassani N, Haruyama N, Saito T, Saido T, Hokama M, Iwaki T, Ohara T, Ninomiya T, Kiyohara Y, Sakumi K, LaFerla FM, Nakabeppu Y. Comparative profiling of cortical gene expression in Alzheimer's disease patients and mouse models demonstrates a link between amyloidosis and neuroinflammation. Sci Rep 2017; 7:17762. [PMID: 29259249 PMCID: PMC5736730 DOI: 10.1038/s41598-017-17999-3] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 12/05/2017] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia, characterized by accumulation of amyloid β (Aβ) and neurofibrillary tangles. Oxidative stress and inflammation are considered to play an important role in the development and progression of AD. However, the extent to which these events contribute to the Aβ pathologies remains unclear. We performed inter-species comparative gene expression profiling between AD patient brains and the App NL-G-F/NL-G-F and 3xTg-AD-H mouse models. Genes commonly altered in App NL-G-F/NL-G-F and human AD cortices correlated with the inflammatory response or immunological disease. Among them, expression of AD-related genes (C4a/C4b, Cd74, Ctss, Gfap, Nfe2l2, Phyhd1, S100b, Tf, Tgfbr2, and Vim) was increased in the App NL-G-F/NL-G-F cortex as Aβ amyloidosis progressed with exacerbated gliosis, while genes commonly altered in the 3xTg-AD-H and human AD cortices correlated with neurological disease. The App NL-G-F/NL-G-F cortex also had altered expression of genes (Abi3, Apoe, Bin2, Cd33, Ctsc, Dock2, Fcer1g, Frmd6, Hck, Inpp5D, Ly86, Plcg2, Trem2, Tyrobp) defined as risk factors for AD by genome-wide association study or identified as genetic nodes in late-onset AD. These results suggest a strong correlation between cortical Aβ amyloidosis and the neuroinflammatory response and provide a better understanding of the involvement of gender effects in the development of AD.
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Affiliation(s)
- Erika Castillo
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Julio Leon
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.,Department of Neurology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Guianfranco Mazzei
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Nona Abolhassani
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Naoki Haruyama
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Saitama, Japan
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Saitama, Japan
| | - Masaaki Hokama
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.,Department of Neurosurgery, Japan Community Health Care Organization Kyushu Hospital, Kitakyushu, 806-8501, Japan
| | - Toru Iwaki
- Department of Neuropathology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Tomoyuki Ohara
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Toshiharu Ninomiya
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yutaka Kiyohara
- Hisayama Research Institute for Lifestyle Diseases, Hisayama, Fukuoka, Japan
| | - Kunihiko Sakumi
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Frank M LaFerla
- Department of Neurobiology and Behavior, University of California, Irvine, CA, 92697, USA
| | - Yusaku Nakabeppu
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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103
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Michel L, Reygagne P, Benech P, Jean-Louis F, Scalvino S, Ly Ka So S, Hamidou Z, Bianovici S, Pouch J, Ducos B, Bonnet M, Bensussan A, Patatian A, Lati E, Wdzieczak-Bakala J, Choulot JC, Loing E, Hocquaux M. Study of gene expression alteration in male androgenetic alopecia: evidence of predominant molecular signalling pathways. Br J Dermatol 2017; 177:1322-1336. [PMID: 28403520 DOI: 10.1111/bjd.15577] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2017] [Indexed: 01/01/2023]
Abstract
BACKGROUND Male androgenetic alopecia (AGA) is the most common form of hair loss in men. It is characterized by a distinct pattern of progressive hair loss starting from the frontal area and the vertex of the scalp. Although several genetic risk loci have been identified, relevant genes for AGA remain to be defined. OBJECTIVES To identify biomarkers associated with AGA. METHODS Molecular biomarkers associated with premature AGA were identified through gene expression analysis using cDNA generated from scalp vertex biopsies of hairless or bald men with premature AGA, and healthy volunteers. RESULTS This monocentric study reveals that genes encoding mast cell granule enzymes, inflammatory mediators and immunoglobulin-associated immune mediators were significantly overexpressed in AGA. In contrast, underexpressed genes appear to be associated with the Wnt/β-catenin and bone morphogenic protein/transforming growth factor-β signalling pathways. Although involvement of these pathways in hair follicle regeneration is well described, functional interpretation of the transcriptomic data highlights different events that account for their inhibition. In particular, one of these events depends on the dysregulated expression of proopiomelanocortin, as confirmed by polymerase chain reaction and immunohistochemistry. In addition, lower expression of CYP27B1 in patients with AGA supports the notion that changes in vitamin D metabolism contributes to hair loss. CONCLUSIONS This study provides compelling evidence for distinct molecular events contributing to alopecia that may pave the way for new therapeutic approaches.
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Affiliation(s)
- L Michel
- Inserm UMR976, Skin Research Institute, F-75475, Paris, France.,University Paris Diderot, Sorbonne Paris-Cité, Hôpital Saint-Louis, F-75475, Paris, France
| | - P Reygagne
- Centre Sabouraud, F-75475, Paris, France
| | - P Benech
- NICN UMR 7259 CNRS Faculté de Médecine, 13344, Marseille, France.,GENEX, 91160, Longjumeau, France
| | - F Jean-Louis
- Inserm UMR976, Skin Research Institute, F-75475, Paris, France.,University Paris Diderot, Sorbonne Paris-Cité, Hôpital Saint-Louis, F-75475, Paris, France
| | - S Scalvino
- Laboratoire BIO-EC, 91160, Longjumeau, France
| | - S Ly Ka So
- Inserm UMR976, Skin Research Institute, F-75475, Paris, France
| | - Z Hamidou
- Centre Sabouraud, F-75475, Paris, France
| | | | - J Pouch
- Plateforme de qPCR à Haut Débit Genomic Paris Centre, IBENS, 75005, Paris, France
| | - B Ducos
- Plateforme de qPCR à Haut Débit Genomic Paris Centre, IBENS, 75005, Paris, France.,Laboratoire de Physique Statistique, École Normale Supérieure, PSL Research University, University Paris Diderot, Sorbonne Paris-Cité, CNRS, 75005, Paris, France
| | - M Bonnet
- Inserm UMR976, Skin Research Institute, F-75475, Paris, France
| | - A Bensussan
- Inserm UMR976, Skin Research Institute, F-75475, Paris, France.,University Paris Diderot, Sorbonne Paris-Cité, Hôpital Saint-Louis, F-75475, Paris, France
| | | | - E Lati
- GENEX, 91160, Longjumeau, France.,Laboratoire BIO-EC, 91160, Longjumeau, France
| | | | | | - E Loing
- IEB-Lucas Meyer Cosmetics, 31520, Ramonville, France
| | - M Hocquaux
- IEB-Lucas Meyer Cosmetics, 31520, Ramonville, France
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104
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George C, Gontier G, Lacube P, François JC, Holzenberger M, Aïd S. The Alzheimer's disease transcriptome mimics the neuroprotective signature of IGF-1 receptor-deficient neurons. Brain 2017; 140:2012-2027. [PMID: 28595357 DOI: 10.1093/brain/awx132] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 04/12/2017] [Indexed: 12/22/2022] Open
Abstract
Seminal studies using post-mortem brains of patients with Alzheimer's disease evidenced aberrant insulin-like growth factor 1 receptor (IGF1R) signalling. Addressing causality, work in animal models recently demonstrated that long-term suppression of IGF1R signalling alleviates Alzheimer's disease progression and promotes neuroprotection. However, the underlying mechanisms remain largely elusive. Here, we showed that genetically ablating IGF1R in neurons of the ageing brain efficiently protects from neuroinflammation, anxiety and memory impairments induced by intracerebroventricular injection of amyloid-β oligomers. In our mutant mice, the suppression of IGF1R signalling also invariably led to small neuronal soma size, indicative of profound changes in cellular homeodynamics. To gain insight into transcriptional signatures leading to Alzheimer's disease-relevant neuronal defence, we performed genome-wide microarray analysis on laser-dissected hippocampal CA1 after neuronal IGF1R knockout, in the presence or absence of APP/PS1 transgenes. Functional analysis comparing neurons in early-stage Alzheimer's disease with IGF1R knockout neurons revealed strongly convergent transcriptomic signatures, notably involving neurite growth, cytoskeleton organization, cellular stress response and neurotransmission. Moreover, in Alzheimer's disease neurons, a high proportion of genes responding to Alzheimer's disease showed a reversed differential expression when IGF1R was deleted. One of the genes consistently highlighted in genome-wide comparison was the neurofilament medium polypeptide Nefm. We found that NEFM accumulated in hippocampus in the presence of amyloid pathology, and decreased to control levels under IGF1R deletion, suggesting that reorganized cytoskeleton likely plays a role in neuroprotection. These findings demonstrated that significant resistance of the brain to amyloid-β can be achieved lifelong by suppressing neuronal IGF1R and identified IGF-dependent molecular pathways that coordinate an intrinsic program for neuroprotection against proteotoxicity. Our data also indicate that neuronal defences against Alzheimer's disease rely on an endogenous gene expression profile similar to the neuroprotective response activated by genetic disruption of IGF1R signalling. This study highlights neuronal IGF1R signalling as a relevant target for developing Alzheimer's disease prevention strategies.
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Affiliation(s)
- Caroline George
- INSERM, Centre de Recherche Saint-Antoine, 75012 Paris, France.,Sorbonne Universités, UPMC - Université Pierre et Marie Curie, 75012 Paris, France
| | - Géraldine Gontier
- INSERM, Centre de Recherche Saint-Antoine, 75012 Paris, France.,Sorbonne Universités, UPMC - Université Pierre et Marie Curie, 75012 Paris, France
| | - Philippe Lacube
- INSERM, Centre de Recherche Saint-Antoine, 75012 Paris, France.,Sorbonne Universités, UPMC - Université Pierre et Marie Curie, 75012 Paris, France
| | - Jean-Christophe François
- INSERM, Centre de Recherche Saint-Antoine, 75012 Paris, France.,Sorbonne Universités, UPMC - Université Pierre et Marie Curie, 75012 Paris, France
| | - Martin Holzenberger
- INSERM, Centre de Recherche Saint-Antoine, 75012 Paris, France.,Sorbonne Universités, UPMC - Université Pierre et Marie Curie, 75012 Paris, France
| | - Saba Aïd
- INSERM, Centre de Recherche Saint-Antoine, 75012 Paris, France.,Sorbonne Universités, UPMC - Université Pierre et Marie Curie, 75012 Paris, France
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105
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Keren-Shaul H, Spinrad A, Weiner A, Matcovitch-Natan O, Dvir-Szternfeld R, Ulland TK, David E, Baruch K, Lara-Astaiso D, Toth B, Itzkovitz S, Colonna M, Schwartz M, Amit I. A Unique Microglia Type Associated with Restricting Development of Alzheimer's Disease. Cell 2017; 169:1276-1290.e17. [PMID: 28602351 DOI: 10.1016/j.cell.2017.05.018] [Citation(s) in RCA: 2812] [Impact Index Per Article: 401.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/10/2017] [Accepted: 05/11/2017] [Indexed: 01/23/2023]
Abstract
Alzheimer's disease (AD) is a detrimental neurodegenerative disease with no effective treatments. Due to cellular heterogeneity, defining the roles of immune cell subsets in AD onset and progression has been challenging. Using transcriptional single-cell sorting, we comprehensively map all immune populations in wild-type and AD-transgenic (Tg-AD) mouse brains. We describe a novel microglia type associated with neurodegenerative diseases (DAM) and identify markers, spatial localization, and pathways associated with these cells. Immunohistochemical staining of mice and human brain slices shows DAM with intracellular/phagocytic Aβ particles. Single-cell analysis of DAM in Tg-AD and triggering receptor expressed on myeloid cells 2 (Trem2)-/- Tg-AD reveals that the DAM program is activated in a two-step process. Activation is initiated in a Trem2-independent manner that involves downregulation of microglia checkpoints, followed by activation of a Trem2-dependent program. This unique microglia-type has the potential to restrict neurodegeneration, which may have important implications for future treatment of AD and other neurodegenerative diseases. VIDEO ABSTRACT.
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Affiliation(s)
- Hadas Keren-Shaul
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Amit Spinrad
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Assaf Weiner
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel; Hubrecht Institute-KNAW (Royal Netherlands Academy of Arts and Sciences), and University Medical Center, Cancer Genomics Netherlands, 3584 CG Utrecht, the Netherlands.
| | - Orit Matcovitch-Natan
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Raz Dvir-Szternfeld
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tyler K Ulland
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Eyal David
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Kuti Baruch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - David Lara-Astaiso
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Beata Toth
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michal Schwartz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Ido Amit
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel.
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106
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van Gijsel-Bonnello M, Baranger K, Benech P, Rivera S, Khrestchatisky M, de Reggi M, Gharib B. Metabolic changes and inflammation in cultured astrocytes from the 5xFAD mouse model of Alzheimer's disease: Alleviation by pantethine. PLoS One 2017; 12:e0175369. [PMID: 28410378 PMCID: PMC5391924 DOI: 10.1371/journal.pone.0175369] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/26/2017] [Indexed: 12/14/2022] Open
Abstract
Astrocytes play critical roles in central nervous system homeostasis and support of neuronal function. A better knowledge of their response may both help understand the pathophysiology of Alzheimer's disease (AD) and implement new therapeutic strategies. We used the 5xFAD transgenic mouse model of AD (Tg thereafter) to generate astrocyte cultures and investigate the impact of the genotype on metabolic changes and astrocytes activation. Metabolomic analysis showed that Tg astrocytes exhibited changes in the glycolytic pathway and tricarboxylic acid (TCA) cycle, compared to wild type (WT) cells. Tg astrocytes displayed also a prominent basal inflammatory status, with accentuated reactivity and increased expression of the inflammatory cytokine interleukin-1 beta (IL-1β). Compensatory mechanisms were activated in Tg astrocytes, including: i) the hexose monophosphate shunt with the consequent production of reducing species; ii) the induction of hypoxia inducible factor-1 alpha (HIF-1α), known to protect against amyloid-β (Aβ) toxicity. Such events were associated with the expression by Tg astrocytes of human isoforms of both amyloid precursor protein (APP) and presenilin-1 (PS1). Similar metabolic and inflammatory changes were induced in WT astrocytes by exogenous Aβ peptide. Pantethine, the vitamin B5 precursor, known to be neuroprotective and anti-inflammatory, alleviated the pathological pattern in Tg astrocytes as well as WT astrocytes treated with Aß. In conclusion, our data enlighten the dual pathogenic/protective role of astrocytes in AD pathology and the potential protective role of pantethine.
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Affiliation(s)
| | | | | | | | | | - Max de Reggi
- Aix Marseille Univ, CNRS, NICN, Marseille, France
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107
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Molino Y, Jabès F, Bonnet A, Gaudin N, Bernard A, Benech P, Khrestchatisky M. Gene expression comparison reveals distinct basal expression of HOX members and differential TNF-induced response between brain- and spinal cord-derived microvascular endothelial cells. J Neuroinflammation 2016; 13:290. [PMID: 27832801 PMCID: PMC5105278 DOI: 10.1186/s12974-016-0749-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 10/18/2016] [Indexed: 01/12/2023] Open
Abstract
Background The heterogeneity of endothelial cell types underlies their remarkable ability to sub-specialize and provide specific requirements for a given vascular bed. Here, we compared rat microvascular endothelial cells (MECs) derived from the brain and spinal cord in both basal and inflammatory conditions. Methods We used whole rat genome microarrays to compare, at different time points, basal and TNF-α-induced gene expression of rat MECs from in vitro models of the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB). Validation at both messenger RNA (mRNA) and protein levels was performed on freshly extracted microvessels (MVs) from the brain and spinal cord (BMVs and SCMVs, respectively), as these were considered the closest in vivo tissues to cultured MECs. Results Most of the genes encoding adhesion/tight junction molecules and known endothelial markers were similarly expressed in brain and spinal cord MECs (BMECs and SCMECs, respectively). However, one striking finding was the higher expression of several Hox genes, which encode transcription factors involved in positional identity. The differential expression of Hoxa9 and Hoxb7 at the mRNA levels as well as protein levels was confirmed in BMVs and SCMVs. Although the TNF-α response was in general higher in BMECs than in SCMECs at 12 h, the opposite was observed at 48 h. Furthermore, we found that expression of Tnfrsf1a and Tnfrsf1b encoding the TNF receptor super-family member 1a/TNFR1 and 1b/TNFR2, respectively, were constitutively higher in BMVs compared to SCMVs. However, only Tnfrsf1b was induced in SCMECs in response to TNF-α at 24 and 48 h. Conclusions Our results support a role for HOX members in defining the positional identities of MECs in vivo. Our data also suggest that the delayed transcriptional activation upon TNF-α treatment in SCMECs results from the requirement of the TNF-induced expression of Tnfrsf1b. In contrast, its high basal expression in BMECs might be sufficient to confer an immediate and efficient TNF-α response. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0749-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yves Molino
- Vect-Horus SAS, Faculté de Médecine - Secteur Nord, 51 Bd Pierre Dramard, 13344, Marseille Cedex 15, France
| | - Françoise Jabès
- Vect-Horus SAS, Faculté de Médecine - Secteur Nord, 51 Bd Pierre Dramard, 13344, Marseille Cedex 15, France
| | | | | | - Anne Bernard
- Aix Marseille Univ, CNRS, NICN, Marseille, France
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108
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Weissmann R, Hüttenrauch M, Kacprowski T, Bouter Y, Pradier L, Bayer TA, Kuss AW, Wirths O. Gene Expression Profiling in the APP/PS1KI Mouse Model of Familial Alzheimer's Disease. J Alzheimers Dis 2016; 50:397-409. [PMID: 26639971 DOI: 10.3233/jad-150745] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by early intraneuronal amyloid-β (Aβ) accumulation, extracellular deposition of Aβ peptides, and intracellular hyperphosphorylated tau aggregates. These lesions cause dendritic and synaptic alterations and induce an inflammatory response in the diseased brain. Although the neuropathological characteristics of AD have been known for decades, the molecular mechanisms causing the disease are still under investigation. Studying gene expression changes in postmortem AD brain tissue can yield new insights into the molecular disease mechanisms. To that end, one can employ transgenic AD mouse models and the next-generation sequencing technology. In this study, a whole-brain transcriptome analysis was carried out using the well-characterized APP/PS1KI mouse model for AD. These mice display a robust phenotype reflected by working memory deficits at 6 months of age, a significant neuron loss in a variety of brain areas including the CA1 region of the hippocampus and a severe amyloid pathology. Based on deep sequencing, differentially expressed genes (DEGs) between 6-month-old WT or PS1KI and APP/PS1KI were identified and verified by qRT-PCR. Compared to WT mice, 250 DEGs were found in APP/PS1KI mice, while 186 DEGs could be found compared to PS1KI control mice. Most of the DEGs were upregulated in APP/PS1KI mice and belong to either inflammation-associated pathways or lysosomal activation, which is likely due to the robust intraneuronal accumulation of Aβ in this mouse model. Our comprehensive brain transcriptome study further highlights APP/PS1KI mice as a valuable model for AD, covering molecular inflammatory and immune responses.
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Affiliation(s)
- Robert Weissmann
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Melanie Hüttenrauch
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - Tim Kacprowski
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine and Ernst-Moritz-Arndt University Greifswald, Germany
| | - Yvonne Bouter
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - Laurent Pradier
- Sanofi, Therapeutic Strategy Unit Neurodegeneration and Pain, Chilly Mazarin, France
| | - Thomas A Bayer
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - Andreas W Kuss
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Oliver Wirths
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
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109
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Can MRI T 1 be used to detect early changes in 5xFAD Alzheimer's mouse brain? MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 30:153-163. [PMID: 27785640 PMCID: PMC5364252 DOI: 10.1007/s10334-016-0593-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/13/2016] [Accepted: 10/04/2016] [Indexed: 10/31/2022]
Abstract
OBJECTIVES In the present study, we have tested whether MRI T1 relaxation time is a sensitive marker to detect early stages of amyloidosis and gliosis in the young 5xFAD transgenic mouse, a well-established animal model for Alzheimer's disease. MATERIALS AND METHODS 5xFAD and wild-type mice were imaged in a 4.7 T Varian horizontal bore MRI system to generate T1 quantitative maps using the spin-echo multi-slice sequence. Following immunostaining for glial fibrillary acidic protein, Iba-1, and amyloid-β, T1 and area fraction of staining were quantified in the posterior parietal and primary somatosensory cortex and corpus callosum. RESULTS In comparison with age-matched wild-type mice, we observed first signs of amyloidosis in 2.5-month-old 5xFAD mice, and development of gliosis in 5-month-old 5xFAD mice. In contrast, MRI T1 relaxation times of young, i.e., 2.5- and 5-month-old, 5xFAD mice were not significantly different to those of age-matched wild-type controls. Furthermore, although disease progression was detectable by increased amyloid-β load in the brain of 5-month-old 5xFAD mice compared with 2.5-month-old 5xFAD mice, MRI T1 relaxation time did not change. CONCLUSIONS In summary, our data suggest that MRI T1 relaxation time is neither a sensitive measure of disease onset nor progression at early stages in the 5xFAD mouse transgenic mouse model.
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Kamphuis W, Kooijman L, Schetters S, Orre M, Hol EM. Transcriptional profiling of CD11c-positive microglia accumulating around amyloid plaques in a mouse model for Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1847-60. [DOI: 10.1016/j.bbadis.2016.07.007] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/01/2016] [Accepted: 07/13/2016] [Indexed: 12/25/2022]
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111
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Yamazaki Y, Painter MM, Bu G, Kanekiyo T. Apolipoprotein E as a Therapeutic Target in Alzheimer's Disease: A Review of Basic Research and Clinical Evidence. CNS Drugs 2016; 30:773-89. [PMID: 27328687 PMCID: PMC5526196 DOI: 10.1007/s40263-016-0361-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that causes progressive cognitive decline. The majority of AD cases are sporadic and late-onset (>65 years old) making it the leading cause of dementia in the elderly. While both genetic and environmental factors contribute to the development of late-onset AD (LOAD), APOE polymorphism is a major genetic risk determinant for LOAD. In humans, the APOE gene has three major allelic variants: ε2, ε3, and ε4, of which APOE ε4 is the strongest genetic risk factor for LOAD, whereas APOE ε2 is protective. Mounting evidence suggests that APOE ε4 contributes to AD pathogenesis through multiple pathways including facilitated amyloid-β deposition, increased tangle formation, synaptic dysfunction, exacerbated neuroinflammation, and cerebrovascular defects. Since APOE modulates multiple biological processes through its corresponding protein apolipoprotein E (apoE), APOE gene and apoE properties have been a promising target for therapy and drug development against AD. In this review, we summarize the current evidence regarding how the APOE ε4 allele contributes to the pathogenesis of AD and how relevant therapeutic approaches can be developed to target apoE-mediated pathways in AD.
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Affiliation(s)
- Yu Yamazaki
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Meghan M Painter
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Takahisa Kanekiyo
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
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Chen W, Abud EA, Yeung ST, Lakatos A, Nassi T, Wang J, Blum D, Buée L, Poon WW, Blurton-Jones M. Increased tauopathy drives microglia-mediated clearance of beta-amyloid. Acta Neuropathol Commun 2016; 4:63. [PMID: 27339073 PMCID: PMC4918195 DOI: 10.1186/s40478-016-0336-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/13/2016] [Indexed: 12/23/2022] Open
Abstract
Alzheimer disease is characterized by the accumulation of β-amyloid (Aβ) plaques and tau-laden neurofibrillary tangles. Emerging studies suggest that in neurodegenerative diseases, aggregation of one protein species can promote other proteinopathies and that inflammation plays an important role in this process. To study the interplay between Aβ deposition, tau pathology, and microgliosis, we established a new AD transgenic mouse model by crossing 5xfAD mice with Thy-Tau22 transgenic mice. The resulting 'T5x' mice exhibit a greater than three-fold increase in misfolded and hyperphosphorylated tau and further substantiates the hypothesis that Aβ accelerates tau pathology. Surprisingly, T5x mice exhibit a 40-50 % reduction in Aβ plaque load and insoluble Aβ species when compared with aged-matched 5xfAD littermates. T5x mice exhibit significant changes in cytokine production, an almost doubling of microglial number, and a dramatic shift in microglia activation state. Furthermore, T5x microglia exhibit increased phagocytic capacity that enhances the clearance of insoluble Aβ and decreasing plaque load. Therefore, our results suggest that strategies to increase the phagocytic ability of microglia can be employed to reduce Aβ and that tau-induced changes in microglial activation state can promote the clearance of Aβ.
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113
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Martini-Stoica H, Xu Y, Ballabio A, Zheng H. The Autophagy-Lysosomal Pathway in Neurodegeneration: A TFEB Perspective. Trends Neurosci 2016; 39:221-234. [PMID: 26968346 PMCID: PMC4928589 DOI: 10.1016/j.tins.2016.02.002] [Citation(s) in RCA: 285] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/03/2016] [Accepted: 02/09/2016] [Indexed: 02/08/2023]
Abstract
The autophagy-lysosomal pathway (ALP) is involved in the degradation of long-lived proteins. Deficits in the ALP result in protein aggregation, the generation of toxic protein species, and accumulation of dysfunctional organelles, which are hallmarks of Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and prion disease. Decades of research have therefore focused on enhancing the ALP in neurodegenerative diseases. More recently, transcription factor EB (TFEB), a major regulator of autophagy and lysosomal biogenesis, has emerged as a leading factor in addressing disease pathology. We review the regulation of the ALP and TFEB and their impact on neurodegenerative diseases. We also offer our perspective on the complex role of autophagy and TFEB in disease pathogenesis and its therapeutic implications through the examination of prion disease.
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Affiliation(s)
- Heidi Martini-Stoica
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA; Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Yin Xu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Andrea Ballabio
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Dan and Jan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Telethon Institute of Genetics and Medicine (TIGEM) and Department of Translational Medical Sciences, Frederico II University, Naples, Italy
| | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX.
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114
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Zheng H, Liu CC, Atagi Y, Chen XF, Jia L, Yang L, He W, Zhang X, Kang SS, Rosenberry TL, Fryer JD, Zhang YW, Xu H, Bu G. Opposing roles of the triggering receptor expressed on myeloid cells 2 and triggering receptor expressed on myeloid cells-like transcript 2 in microglia activation. Neurobiol Aging 2016; 42:132-41. [PMID: 27143430 DOI: 10.1016/j.neurobiolaging.2016.03.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 02/14/2016] [Accepted: 03/06/2016] [Indexed: 01/12/2023]
Abstract
Mutations in triggering receptor expressed on myeloid cells 2 (TREM2), which has been proposed to regulate the inflammatory responses and the clearance of apoptotic neurons and/or amyloid-β, are genetically linked to increased risk for late-onset Alzheimer's disease (AD). Interestingly, a missense variant in TREM-like transcript 2 (TREML2), a structurally similar protein encoded by the same gene cluster with TREM2 on chromosome 6, has been shown to protect against AD. However, the molecular mechanisms by which TREM2 and TREML2 regulate the pathogenesis of AD, and their functional relationship, if any, remain unclear. Here, we show that lipopolysaccharide (LPS) stimulation significantly suppressed TREM2 but increased TREML2 expression in mouse brain. Consistent with this in vivo result, LPS or oligomeric amyloid-β treatment down regulated TREM2 but up-regulated TREML2 expression in primary microglia. Most important, modulation of TREM2 or TREML2 levels had opposing effects on inflammatory responses with enhancement or suppression of LPS-induced proinflammatory cytokine gene expression observed on TREM2 or TREML2 down regulation, respectively. In addition, the proliferation of primary microglia was significantly decreased when TREM2 was down regulated, whereas it was increased on TREML2 knockdown. Together, our results suggest that several microglial functions are strictly regulated by TREM2 and TREML2, whose dysfunctions likely contribute to AD pathogenesis by impairing brain innate immunity. Our findings provide novel mechanistic insights into the functions of TREM2 and TREML2 in microglia and have implications on designing new therapeutic strategies to treat AD.
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Affiliation(s)
- Honghua Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Yuka Atagi
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Xiao-Fen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China
| | - Lin Jia
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China
| | - Longyu Yang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China
| | - Wencan He
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China
| | - Xilin Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China
| | - Silvia S Kang
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | | | - John D Fryer
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA; Neurobiology of Disease Graduate Program, Mayo Clinic, Jacksonville, FL, USA
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China; Degenerative Disease Research Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China; Degenerative Disease Research Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Guojun Bu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, PR China; Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA; Neurobiology of Disease Graduate Program, Mayo Clinic, Jacksonville, FL, USA.
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115
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Vitamin D interacts with Esr1 and Igf1 to regulate molecular pathways relevant to Alzheimer's disease. Mol Neurodegener 2016; 11:22. [PMID: 26932723 PMCID: PMC4774101 DOI: 10.1186/s13024-016-0087-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 02/23/2016] [Indexed: 01/05/2023] Open
Abstract
Background Increasing evidence suggests a potential therapeutic benefit of vitamin D supplementation against Alzheimer’s disease (AD). Although studies have shown improvements in cognitive performance and decreases in markers of the pathology after chronic treatment, the mechanisms by which vitamin D acts on brain cells are multiple and remain to be thoroughly studied. We analyzed the molecular changes observed after 5 months of vitamin D3 supplementation in the brains of transgenic 5xFAD (Tg) mice, a recognized mouse model of AD, and their wild type (Wt) littermates. We first performed a kinematic behavioural examination at 4, 6 and 8 months of age (M4, M6 and M8) followed by a histologic assessment of AD markers. We then performed a comparative transcriptomic analysis of mRNA regulation in the neocortex and hippocampus of 9 months old (M9) female mice. Results Transcriptomic analysis of the hippocampus and neocortex of both Wt and Tg mice at M9, following 5 months of vitamin D3 treatment, reveals a large panel of dysregulated pathways related to i) immune and inflammatory response, ii) neurotransmitter activity, iii) endothelial and vascular processes and iv) hormonal alterations. The differentially expressed genes are not all direct targets of the vitamin D-VDR pathway and it appears that vitamin D action engages in the crosstalk with estrogen and insulin signaling. The misexpression of the large number of genes observed in this study translates into improved learning and memory performance and a decrease in amyloid plaques and astrogliosis in Tg animals. Conclusions This study underlies the multiplicity of action of this potent neurosteroid in an aging and AD-like brain. The classical and non-classical actions of vitamin D3 can act in an additive and possibly synergistic manner to induce neuroprotective activities in a context-specific way. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0087-2) contains supplementary material, which is available to authorized users.
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116
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Lian H, Zheng H. Signaling pathways regulating neuron-glia interaction and their implications in Alzheimer's disease. J Neurochem 2016; 136:475-91. [PMID: 26546579 PMCID: PMC4720533 DOI: 10.1111/jnc.13424] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/23/2015] [Accepted: 10/28/2015] [Indexed: 12/11/2022]
Abstract
Astrocytes are the most abundant cells in the central nervous system. They play critical roles in neuronal homeostasis through their physical properties and neuron-glia signaling pathways. Astrocytes become reactive in response to neuronal injury and this process, referred to as reactive astrogliosis, is a common feature accompanying neurodegenerative conditions, particularly Alzheimer's disease. Reactive astrogliosis represents a continuum of pathobiological processes and is associated with morphological, functional, and gene expression changes of varying degrees. There has been a substantial growth of knowledge regarding the signaling pathways regulating glial biology and pathophysiology in recent years. Here, we attempt to provide an unbiased review of some of the well-known players, namely calcium, proteoglycan, transforming growth factor β, NFκB, and complement, in mediating neuron-glia interaction under physiological conditions as well as in Alzheimer's disease. This review discusses the role of astrocytic NFκB and calcium as well as astroglial secreted factors, including proteoglycans, TGFβ, and complement in mediating neuronal function and AD pathogenesis through direct interaction with neurons and through cooperation with microglia.
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Affiliation(s)
- Hong Lian
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
- Institute of Neuroscience, Xiamen University College of Medicine, Xiamen, Fujian 361102, China
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117
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Onos KD, Sukoff Rizzo SJ, Howell GR, Sasner M. Toward more predictive genetic mouse models of Alzheimer's disease. Brain Res Bull 2015; 122:1-11. [PMID: 26708939 DOI: 10.1016/j.brainresbull.2015.12.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 12/09/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023]
Abstract
Genetic mouse models for Alzheimer's disease (AD) have been widely used to understand aspects of the biology of the disease, but have had limited success in translating these findings to the clinic. In this review, we discuss the benefits and limitations of existing genetic models and recent advances in technologies (including high throughput sequencing and genome editing) that promise more predictive models. We summarize widely used biomarkers and behavioral tests for mouse models of AD and highlight best practices that will maximize translatability of preclinical findings.
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Affiliation(s)
| | | | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, United States; Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA, United States.
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118
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Song F, Qian Y, Peng X, Han G, Wang J, Bai Z, Crack PJ, Lei H. Perturbation of the transcriptome: implications of the innate immune system in Alzheimer's disease. Curr Opin Pharmacol 2015; 26:47-53. [PMID: 26480202 DOI: 10.1016/j.coph.2015.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 09/29/2015] [Accepted: 09/30/2015] [Indexed: 12/01/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease with broad impact. Although Aβ and tau have been proposed as the key molecules in the disease mechanism, comprehensive understanding of AD pathogenesis requires a systemic view at the genomic level. From studies on the brain transcriptome of AD, we have gradually realized the contribution of the immune system to AD development. Recent explorations on the blood transcriptome of AD patients have revealed robust immune activation in the peripheral blood. The combination of transcriptome studies and other types of studies has further elucidated the roles of specific immune pathways in distinct cell types during AD development and highlighted the critical contributions from immune genes such as TREM2.
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Affiliation(s)
- Fuhai Song
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Ying Qian
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xing Peng
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Guangchun Han
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Jiajia Wang
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Zhouxian Bai
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Peter J Crack
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Australia
| | - Hongxing Lei
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China.
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119
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Saura CA, Parra-Damas A, Enriquez-Barreto L. Gene expression parallels synaptic excitability and plasticity changes in Alzheimer's disease. Front Cell Neurosci 2015; 9:318. [PMID: 26379494 PMCID: PMC4548151 DOI: 10.3389/fncel.2015.00318] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/03/2015] [Indexed: 11/14/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by abnormal accumulation of β-amyloid and tau and synapse dysfunction in memory-related neural circuits. Pathological and functional changes in the medial temporal lobe, a region essential for explicit memory encoding, contribute to cognitive decline in AD. Surprisingly, functional imaging studies show increased activity of the hippocampus and associated cortical regions during memory tasks in presymptomatic and early AD stages, whereas brain activity declines as the disease progresses. These findings suggest an emerging scenario where early pathogenic events might increase neuronal excitability leading to enhanced brain activity before clinical manifestations of the disease, a stage that is followed by decreased brain activity as neurodegeneration progresses. The mechanisms linking pathology with synaptic excitability and plasticity changes leading to memory loss in AD remain largely unclear. Recent studies suggest that increased brain activity parallels enhanced expression of genes involved in synaptic transmission and plasticity in preclinical stages, whereas expression of synaptic and activity-dependent genes are reduced by the onset of pathological and cognitive symptoms. Here, we review recent evidences indicating a relationship between transcriptional deregulation of synaptic genes and neuronal activity and memory loss in AD and mouse models. These findings provide the basis for potential clinical applications of memory-related transcriptional programs and their regulatory mechanisms as novel biomarkers and therapeutic targets to restore brain function in AD and other cognitive disorders.
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Affiliation(s)
- Carlos A. Saura
- Institut de Neurociències, Departament de Bioquímica i Biologia Molecular, Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Universitat Autònoma de BarcelonaBarcelona, Spain
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120
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Zhong L, Chen XF, Zhang ZL, Wang Z, Shi XZ, Xu K, Zhang YW, Xu H, Bu G. DAP12 Stabilizes the C-terminal Fragment of the Triggering Receptor Expressed on Myeloid Cells-2 (TREM2) and Protects against LPS-induced Pro-inflammatory Response. J Biol Chem 2015; 290:15866-15877. [PMID: 25957402 DOI: 10.1074/jbc.m115.645986] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Indexed: 11/06/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a DAP12-associated receptor expressed in microglia, macrophages, and other myeloid-derived cells. Previous studies have suggested that TREM2/DAP12 signaling pathway reduces inflammatory responses and promotes phagocytosis of apoptotic neurons. Recently, TREM2 has been identified as a risk gene for Alzheimer disease (AD). Here, we show that DAP12 stabilizes the C-terminal fragment of TREM2 (TREM2-CTF), a substrate for γ-secretase. Co-expression of DAP12 with TREM2 selectively increased the level of TREM2-CTF with little effects on that of full-length TREM2. The interaction between DAP12 and TREM2 is essential for TREM2-CTF stabilization as a mutant form of DAP12 with disrupted interaction with TREM2 failed to exhibit such an effect. Silencing of either Trem2 or Dap12 gene significantly exacerbated pro-inflammatory responses induced by lipopolysaccharides (LPS). Importantly, overexpression of either full-length TREM2 or TREM2-CTF reduced LPS-induced inflammatory responses. Taken together, our results support a role of DAP12 in stabilizing TREM2-CTF, thereby protecting against excessive pro-inflammatory responses.
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Affiliation(s)
- Li Zhong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China
| | - Xiao-Fen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China.
| | - Zhen-Lian Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China
| | - Zhe Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China
| | - Xin-Zhen Shi
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China
| | - Kai Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China; Degenerative Disease Research Program, Center for Neuroscience, Aging, and Stem Cell Research, Sanford-Burnham Medical Research Institute, La Jolla, California 92037
| | - Guojun Bu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, PR China; Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224.
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