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Gayger-Dias V, Menezes L, Da Silva VF, Stiborski A, Silva ACR, Sobottka TM, Quines-Silva VC, Pakulski-Souto B, Bobermin LD, Quincozes-Santos A, Leite MC, Gonçalves CA. Changes in Astroglial Water Flow in the Pre-amyloid Phase of the STZ Model of AD Dementia. Neurochem Res 2024; 49:1851-1862. [PMID: 38733521 DOI: 10.1007/s11064-024-04144-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 03/04/2024] [Accepted: 05/02/2024] [Indexed: 05/13/2024]
Abstract
Alzheimer's disease (AD) is an age-dependent neurodegenerative disease that is typically sporadic and has a high social and economic cost. We utilized the intracerebroventricular administration of streptozotocin (STZ), an established preclinical model for sporadic AD, to investigate hippocampal astroglial changes during the first 4 weeks post-STZ, a period during which amyloid deposition has yet to occur. Astroglial proteins aquaporin 4 (AQP-4) and connexin-43 (Cx-43) were evaluated, as well as claudins, which are tight junction (TJ) proteins in brain barriers, to try to identify changes in the glymphatic system and brain barrier during the pre-amyloid phase. Glial commitment, glucose hypometabolism and cognitive impairment were characterized during this phase. Astroglial involvement was confirmed by an increase in glial fibrillary acidic protein (GFAP); concurrent proteolysis was also observed, possibly mediated by calpain. Levels of AQP-4 and Cx-43 were elevated in the fourth week post-STZ, possibly accelerating the clearance of extracellular proteins, since these proteins actively participate in the glymphatic system. Moreover, although we did not see a functional disruption of the blood-brain barrier (BBB) at this time, claudin 5 (present in the TJ of the BBB) and claudin 2 (present in the TJ of the blood-cerebrospinal fluid barrier) were reduced. Taken together, data support a role for astrocytes in STZ brain damage, and suggest that astroglial dysfunction accompanies or precedes neuronal damage in AD.
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Affiliation(s)
- Vitor Gayger-Dias
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Leonardo Menezes
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Vanessa-Fernanda Da Silva
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Amanda Stiborski
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Ana Carolina Ribeiro Silva
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Thomas Michel Sobottka
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Vitória Cristine Quines-Silva
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Betina Pakulski-Souto
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Larissa Daniele Bobermin
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
- Graduate Program in Neurosciences, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - André Quincozes-Santos
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
- Graduate Program in Neurosciences, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Marina Concli Leite
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil
| | - Carlos-Alberto Gonçalves
- Biochemistry Laboratory 33, Graduate Program in Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil.
- Graduate Program in Neurosciences, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos Street, 2600, Porto Alegre, 90035-003, Brazil.
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Thiankhaw K, Chattipakorn N, Chattipakorn SC. How calcineurin inhibitors affect cognition. Acta Physiol (Oxf) 2024; 240:e14161. [PMID: 38747643 DOI: 10.1111/apha.14161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 06/09/2024]
Abstract
AIMS With a focus on the discrepancy between preclinical and clinical findings, this review will gather comprehensive information about the effects of calcineurin inhibitors (CNI) on cognitive function and related brain pathology from in vitro, in vivo, and clinical studies. We also summarize the potential mechanisms that underlie the pathways related to CNI-induced cognitive impairment. METHODS We systematically searched articles in PubMed using keywords 'calcineurin inhibitor*' and 'cognition' to identify related articles, which the final list pertaining to underlying mechanisms of CNI on cognition. RESULTS Several studies have reported an association between calcineurin and the neuropathology of Alzheimer's disease (AD). AD is the most common neurocognitive disorder associated with amyloid plaques and neurofibrillary tangles in the brain, leading to cognitive impairment. CNI, including tacrolimus and cyclosporin A, are commonly prescribed for patients with transplantation of solid organs such as kidney, liver, or heart, those drugs are currently being used as long-term immunosuppressive therapy. Although preclinical models emphasize the favorable effects of CNI on the restoration of brain pathology due to the impacts of calcineurin on the alleviation of amyloid-beta deposition and tau hyperphosphorylation, or rescuing synaptic and mitochondrial functions, treatment-related neurotoxicity, resulting in cognitive dysfunctions has been observed in clinical settings of patients who received CNI. CONCLUSION Inconsistent results of CNI on cognition from clinical studies have been observed due to impairment of the blood-brain barrier, neuroinflammation mediated by reactive oxygen species, and alteration in mitochondrial fission, and extended research is required to confirm its promising use in cognitive impairment.
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Affiliation(s)
- Kitti Thiankhaw
- Division of Neurology, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nipon Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
| | - Siripron C Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, Thailand
- Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand
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Noche JA, Radhakrishnan H, Ubele MF, Boaz K, Mefford JL, Jones ED, van Rooyen HY, Perpich JA, McCarty K, Meacham B, Smiley J, Bembenek Bailey SA, Puskás LG, Powell DK, Sordo L, Phelan MJ, Norris CM, Head E, Stark CEL. Age-Related Brain Atrophy and the Positive Effects of Behavioral Enrichment in Middle-Aged Beagles. J Neurosci 2024; 44:e2366232024. [PMID: 38561226 PMCID: PMC11097262 DOI: 10.1523/jneurosci.2366-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/08/2024] [Accepted: 02/28/2024] [Indexed: 04/04/2024] Open
Abstract
Aging dogs serve as a valuable preclinical model for Alzheimer's disease (AD) due to their natural age-related development of β-amyloid (Aβ) plaques, human-like metabolism, and large brains that are ideal for studying structural brain aging trajectories from serial neuroimaging. Here we examined the effects of chronic treatment with the calcineurin inhibitor (CNI) tacrolimus or the nuclear factor of activated T cells (NFAT)-inhibiting compound Q134R on age-related canine brain atrophy from a longitudinal study in middle-aged beagles (36 females, 7 males) undergoing behavioral enrichment. Annual MRI was analyzed using modern, automated techniques for region-of-interest-based and voxel-based volumetric assessments. We found that the frontal lobe showed accelerated atrophy with age, while the caudate nucleus remained relatively stable. Remarkably, the hippocampus increased in volume in all dogs. None of these changes were influenced by tacrolimus or Q134R treatment. Our results suggest that behavioral enrichment can prevent atrophy and increase the volume of the hippocampus but does not prevent aging-associated prefrontal cortex atrophy.
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Affiliation(s)
| | - Hamsanandini Radhakrishnan
- University of California, Irvine, California 92697
- University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | | | - Kathy Boaz
- University of Kentucky, Lexington, Kentucky 40506
| | | | - Erin D Jones
- University of Kentucky, Lexington, Kentucky 40506
| | | | | | | | | | | | | | | | | | - Lorena Sordo
- University of California, Irvine, California 92697
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Kraner SD, Sompol P, Prateeptrang S, Promkan M, Hongthong S, Thongsopha N, Nelson PT, Norris CM. Development of a monoclonal antibody specific for a calpain-generated ∆48 kDa calcineurin fragment, a marker of distressed astrocytes. J Neurosci Methods 2024; 402:110012. [PMID: 37984591 PMCID: PMC10841921 DOI: 10.1016/j.jneumeth.2023.110012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/23/2023] [Accepted: 11/09/2023] [Indexed: 11/22/2023]
Abstract
BACKGROUND Calcineurin (CN) is a Ca2+/calmodulin-dependent protein phosphatase. In healthy tissue, CN exists mainly as a full-length (∼60 kDa) highly-regulated protein phosphatase involved in essential cellular functions. However, in diseased or injured tissue, CN is proteolytically converted to a constitutively active fragment that has been causatively-linked to numerous pathophysiologic processes. These calpain-cleaved CN fragments (∆CN) appear at high levels in human brain at early stages of cognitive decline associated with Alzheimer's disease (AD). NEW METHOD We developed a monoclonal antibody to ∆CN, using an immunizing peptide corresponding to the C-terminal end of the ∆CN fragment. RESULTS We obtained a mouse monoclonal antibody, designated 26A6, that selectively detects ∆CN in Western analysis of calpain-cleaved recombinant human CN. Using this antibody, we screened both pathological and normal human brain sections provided by the University of Kentucky's Alzheimer's Disease Research Center. 26A6 showed low reactivity towards normal brain tissue, but detected astrocytes both surrounding AD amyloid plaques and throughout AD brain tissue. In brain tissue with infarcts, there was considerable concentration of 26A6-positive astrocytes within/around infarcts, suggesting a link with anoxic/ischemia pathways. COMPARISON WITH EXISTING METHOD The results obtained with the new monoclonal are similar to those obtained with a polyclonal we had previously developed. However, the monoclonal is an abundant tool available to the dementia research community. CONCLUSIONS The new monoclonal 26A6 antibody is highly selective for the ∆CN proteolytic fragment and labels a subset of astrocytes, and could be a useful tool for marking insidious brain pathology and identifying novel astrocyte phenotypes.
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Affiliation(s)
| | - Pradoldej Sompol
- Sanders Brown Center on Aging, USA; Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Siriyagon Prateeptrang
- Sanders Brown Center on Aging, USA; School of Allied Health Science, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Moltira Promkan
- Sanders Brown Center on Aging, USA; Department of Clinical Microscopy, Faculty of Medical Technology, Mahidol University, Nakhon Pathom 73170, Thailand
| | - Suthida Hongthong
- Sanders Brown Center on Aging, USA; School of Allied Health Science, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Napasorn Thongsopha
- Sanders Brown Center on Aging, USA; School of Allied Health Science, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Peter T Nelson
- Sanders Brown Center on Aging, USA; Department of Pathology, University of Kentucky, Lexington, KY 40536, USA
| | - Christopher M Norris
- Sanders Brown Center on Aging, USA; Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40536, USA.
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Mackiewicz J, Lisek M, Boczek T. Targeting CaN/NFAT in Alzheimer's brain degeneration. Front Immunol 2023; 14:1281882. [PMID: 38077352 PMCID: PMC10701682 DOI: 10.3389/fimmu.2023.1281882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/06/2023] [Indexed: 12/18/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive loss of cognitive functions. While the exact causes of this debilitating disorder remain elusive, numerous investigations have characterized its two core pathologies: the presence of β-amyloid plaques and tau tangles. Additionally, multiple studies of postmortem brain tissue, as well as results from AD preclinical models, have consistently demonstrated the presence of a sustained inflammatory response. As the persistent immune response is associated with neurodegeneration, it became clear that it may also exacerbate other AD pathologies, providing a link between the initial deposition of β-amyloid plaques and the later development of neurofibrillary tangles. Initially discovered in T cells, the nuclear factor of activated T-cells (NFAT) is one of the main transcription factors driving the expression of inflammatory genes and thus regulating immune responses. NFAT-dependent production of inflammatory mediators is controlled by Ca2+-dependent protein phosphatase calcineurin (CaN), which dephosphorylates NFAT and promotes its transcriptional activity. A substantial body of evidence has demonstrated that aberrant CaN/NFAT signaling is linked to several pathologies observed in AD, including neuronal apoptosis, synaptic deficits, and glia activation. In view of this, the role of NFAT isoforms in AD has been linked to disease progression at different stages, some of which are paralleled to diminished cognitive status. The use of classical inhibitors of CaN/NFAT signaling, such as tacrolimus or cyclosporine, or adeno-associated viruses to specifically inhibit astrocytic NFAT activation, has alleviated some symptoms of AD by diminishing β-amyloid neurotoxicity and neuroinflammation. In this article, we discuss the recent findings related to the contribution of CaN/NFAT signaling to the progression of AD and highlight the possible benefits of targeting this pathway in AD treatment.
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Affiliation(s)
| | | | - Tomasz Boczek
- Department of Molecular Neurochemistry, Medical University of Lodz, Lodz, Poland
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Lim D, Tapella L, Dematteis G, Talmon M, Genazzani AA. Calcineurin Signalling in Astrocytes: From Pathology to Physiology and Control of Neuronal Functions. Neurochem Res 2023; 48:1077-1090. [PMID: 36083398 PMCID: PMC10030417 DOI: 10.1007/s11064-022-03744-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 07/31/2022] [Accepted: 08/29/2022] [Indexed: 10/14/2022]
Abstract
Calcineurin (CaN), a Ca2+/calmodulin-activated serine/threonine phosphatase, acts as a Ca2+-sensitive switch regulating cellular functions through protein dephosphorylation and activation of gene transcription. In astrocytes, the principal homeostatic cells in the CNS, over-activation of CaN is known to drive pathological transcriptional remodelling, associated with neuroinflammation in diseases such as Alzheimer's disease, epilepsy and brain trauma. Recent reports suggest that, in physiological conditions, the activity of CaN in astrocytes is transcription-independent and is required for maintenance of basal protein synthesis rate and activation of astrocytic Na+/K+ pump thereby contributing to neuronal functions such as neuronal excitability and memory formation. In this contribution we overview the role of Ca2+ and CaN signalling in astroglial pathophysiology focusing on the emerging physiological role of CaN in astrocytes. We propose a model for the context-dependent switch of CaN activity from the post-transcriptional regulation of cell proteostasis in healthy astrocytes to the CaN-dependent transcriptional activation in neuroinflammation-associated diseases.
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Affiliation(s)
- Dmitry Lim
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy.
| | - Laura Tapella
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy
| | - Giulia Dematteis
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy
| | - Maria Talmon
- Department of Health Sciences, School of Medicine, Università del Piemonte Orientale "Amedeo Avogadro", Via Solaroli 17, 28100, Novara, Italy
| | - Armando A Genazzani
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy.
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Sompol P, Gollihue JL, Weiss BE, Lin RL, Case SL, Kraner SD, Weekman EM, Gant JC, Rogers CB, Niedowicz DM, Sudduth TL, Powell DK, Lin AL, Nelson PT, Thibault O, Wilcock DM, Norris CM. Targeting Astrocyte Signaling Alleviates Cerebrovascular and Synaptic Function Deficits in a Diet-Based Mouse Model of Small Cerebral Vessel Disease. J Neurosci 2023; 43:1797-1813. [PMID: 36746627 PMCID: PMC10010459 DOI: 10.1523/jneurosci.1333-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 02/08/2023] Open
Abstract
Despite the indispensable role that astrocytes play in the neurovascular unit, few studies have investigated the functional impact of astrocyte signaling in cognitive decline and dementia related to vascular pathology. Diet-mediated induction of hyperhomocysteinemia (HHcy) recapitulates numerous features of vascular contributions to cognitive impairment and dementia (VCID). Here, we used astrocyte targeting approaches to evaluate astrocyte Ca2+ dysregulation and the impact of aberrant astrocyte signaling on cerebrovascular dysfunction and synapse impairment in male and female HHcy diet mice. Two-photon imaging conducted in fully awake mice revealed activity-dependent Ca2+ dysregulation in barrel cortex astrocytes under HHcy. Stimulation of contralateral whiskers elicited larger Ca2+ transients in individual astrocytes of HHcy diet mice compared with control diet mice. However, evoked Ca2+ signaling across astrocyte networks was impaired in HHcy mice. HHcy also was associated with increased activation of the Ca2+/calcineurin-dependent transcription factor NFAT4, which has been linked previously to the reactive astrocyte phenotype and synapse dysfunction in amyloid and brain injury models. Targeting the NFAT inhibitor VIVIT to astrocytes, using adeno-associated virus vectors, led to reduced GFAP promoter activity in HHcy diet mice and improved functional hyperemia in arterioles and capillaries. VIVIT expression in astrocytes also preserved CA1 synaptic function and improved spontaneous alternation performance on the Y maze. Together, the results demonstrate that aberrant astrocyte signaling can impair the major functional properties of the neurovascular unit (i.e., cerebral vessel regulation and synaptic regulation) and may therefore represent a promising drug target for treating VCID and possibly Alzheimer's disease and other related dementias.SIGNIFICANCE STATEMENT The impact of reactive astrocytes in Alzheimer's disease and related dementias is poorly understood. Here, we evaluated Ca2+ responses and signaling in barrel cortex astrocytes of mice fed with a B-vitamin deficient diet that induces hyperhomocysteinemia (HHcy), cerebral vessel disease, and cognitive decline. Multiphoton imaging in awake mice with HHcy revealed augmented Ca2+ responses in individual astrocytes, but impaired signaling across astrocyte networks. Stimulation-evoked arteriole dilation and elevated red blood cell velocity in capillaries were also impaired in cortex of awake HHcy mice. Astrocyte-specific inhibition of the Ca2+-dependent transcription factor, NFAT, normalized cerebrovascular function in HHcy mice, improved synaptic properties in brain slices, and stabilized cognition. Results suggest that astrocytes are a mechanism and possible therapeutic target for vascular-related dementia.
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Affiliation(s)
- Pradoldej Sompol
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | - Blaine E Weiss
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | - Ruei-Lung Lin
- Departments of Pharmacology and Nutritional Sciences
| | - Sami L Case
- Departments of Pharmacology and Nutritional Sciences
| | | | | | - John C Gant
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | | | | | | | - Ai-Ling Lin
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | - Peter T Nelson
- Sanders-Brown Center on Aging
- Pathology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Olivier Thibault
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | - Christopher M Norris
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
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Knaryan VH, Sarukhanyan FP. [Ca2+-regulated enzymes calpain and calcineurin in neurodegenerative processes and prospects for neuroprotective pharmacotherapy]. Zh Nevrol Psikhiatr Im S S Korsakova 2023; 123:32-40. [PMID: 37490663 DOI: 10.17116/jnevro202312307132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Calcium (Ca2+) and Ca2+-regulated enzymes calpain and calcineurin are the key molecules of signaling mechanisms in neurons and ensure the normal course of intracellular neurochemical and neurophysiological processes. The imbalance and increase in the intracellular level of Ca2+ correlates with the activation of calpain and calcineurin. Inactivation of endogenous inhibitors and/or absence of exogenous pharmacological inhibitors of these enzymes may induce a cascade of intracellular mechanisms that are detrimental to the structural integrity and functional activity of neurons. The interrelated processes of Ca2+ imbalance, dysregulation of calpain and calcineurin are directly related to the development of intracellular pathophysiological reactions leading to the degeneration and death of selective neuronal populations in neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. The review briefly presents the characteristics of calpain and calcineurin, their interrelated role in the neurodegeneration processes. Data on the efficiency of the exogenous inhibitors (in vivo, in vitro) point out the potential role of pharmacological regulation of calpain and calcineurin for neuroprotection.
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Affiliation(s)
- V H Knaryan
- Buniatian Institute of Biochemistry NAS RA, Yerevan, Armenia
| | - F P Sarukhanyan
- Buniatian Institute of Biochemistry NAS RA, Yerevan, Armenia
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Norris CM. Is It Time to Repurpose Calcineurin Inhibitors for the Treatment of Cognitive Impairment and Dementia? J Alzheimers Dis 2023; 95:599-602. [PMID: 37661889 PMCID: PMC10947791 DOI: 10.3233/jad-230780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Numerous preclinical and human tissue studies implicate the protein phosphatase calcineurin (CN) as a pathophysiologic mechanism in Alzheimer's disease (AD) and other neurodegenerative conditions. Using public electronic records of tens of thousands of individuals across the United States, Silva et al. (2023) show that use of the FDA-approved CN inhibitor, tacrolimus (for purposes of immunosuppression) is also associated with reduced prevalence of dementia-related symptoms. Notably, the study controls for age, sex, and race as well as multiple risk factors for AD. The results suggest that tacrolimus, and possibly other immunosuppressants could be repurposed for the treatment of AD-related dementia.
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Affiliation(s)
- Christopher M. Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA
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10
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Silva JD, Taglialatela G, Jupiter DC. Reduced Prevalence of Dementia in Patients Prescribed Tacrolimus, Sirolimus, or Cyclosporine. J Alzheimers Dis 2023; 95:585-597. [PMID: 37574739 PMCID: PMC10578212 DOI: 10.3233/jad-230526] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2023] [Indexed: 08/15/2023]
Abstract
BACKGROUND Evidence suggests patients prescribed calcineurin inhibitors (CNIs) have a reduced prevalence of dementia, including Alzheimer's disease (AD); however, this result has never been replicated in a large cohort and the involved mechanism(s) and site of action (central versus periphery) remain unclear. OBJECTIVE We aim to determine if prescription of CNIs is associated with reduced prevalence of dementia, including AD, in a large, diverse patient population. Furthermore, we aim to gain insight into the mechanism(s) and site of action for CNIs to reduce dementia prevalence. METHODS Electronic health records (EHRs) from patients prescribed tacrolimus, cyclosporine, or sirolimus were analyzed to compare prevalence, odds, and hazard ratios related to dementia diagnoses among cohorts. EHRs from a random, heterogeneous population from the same network were obtained to generate a general population-like control. RESULTS All drugs examined reduced dementia prevalence compared to the general population-like control. There were no differences in dementia diagnoses upon comparing tacrolimus and sirolimus; however, patients prescribed tacrolimus had a reduced dementia prevalence relative to cyclosporine. CONCLUSION Converging mechanisms of action between tacrolimus and sirolimus likely explain the similar dementia prevalence between the cohorts. Calcineurin inhibition within the brain has a greater probability of reducing dementia relative to peripherally-restricted calcineurin inhibition. Overall, immunosuppressants provide a promising therapeutic avenue for dementia, with emphasis on the brain-penetrant CNI tacrolimus.
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Affiliation(s)
- Jacqueline D. Silva
- Mitchell Center for Neurodegenerative Disorders, Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
- Pharmacology and Toxicology Graduate Program, University of Texas Medical Branch, Galveston, TX, USA
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Disorders, Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
| | - Daniel C. Jupiter
- Department of Biostatistics and Data Science, University of Texas Medical Branch, Galveston, TX, USA
- Department of Orthopedics and Rehabilitation, University of Texas Medical Branch, Galveston, TX, USA
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11
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Lissek T. Activity-Dependent Induction of Younger Biological Phenotypes. Adv Biol (Weinh) 2022; 6:e2200119. [PMID: 35976161 DOI: 10.1002/adbi.202200119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/11/2022] [Indexed: 01/28/2023]
Abstract
In several mammalian species, including humans, complex stimulation patterns such as cognitive and physical exercise lead to improvements in organ function, organism health and performance, as well as possibly longer lifespans. A framework is introduced here in which activity-dependent transcriptional programs, induced by these environmental stimuli, move somatic cells such as neurons and muscle cells toward a state that resembles younger cells to allow remodeling and adaptation of the organism. This cellular adaptation program targets several process classes that are heavily implicated in aging, such as mitochondrial metabolism, cell-cell communication, and epigenetic information processing, and leads to functional improvements in these areas. The activity-dependent gene program (ADGP) can be seen as a natural, endogenous cellular reprogramming mechanism that provides deep insight into the principles of inducible improvements in cell and organism function and can guide the development of therapeutic approaches for longevity. Here, these ADGPs are analyzed, exemplary critical molecular nexus points such as cAMP response element-binding protein, myocyte enhancer factor 2, serum response factor, and c-Fos are identified, and it is explored how one may leverage them to prevent, attenuate, and reverse human aging-related decline of body function.
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Affiliation(s)
- Thomas Lissek
- Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
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12
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Schultz B, Taday J, Menezes L, Cigerce A, Leite MC, Gonçalves CA. Calpain-Mediated Alterations in Astrocytes Before and During Amyloid Chaos in Alzheimer's Disease. J Alzheimers Dis 2021; 84:1415-1430. [PMID: 34719501 DOI: 10.3233/jad-215182] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
One of the changes found in the brain in Alzheimer's disease (AD) is increased calpain, derived from calcium dysregulation, oxidative stress, and/or neuroinflammation, which are all assumed to be basic pillars in neurodegenerative diseases. The role of calpain in synaptic plasticity, neuronal death, and AD has been discussed in some reviews. However, astrocytic calpain changes sometimes appear to be secondary and consequent to neuronal damage in AD. Herein, we explore the possibility of calpain-mediated astroglial reactivity in AD, both preceding and during the amyloid phase. We discuss the types of brain calpains but focus the review on calpains 1 and 2 and some important targets in astrocytes. We address the signaling involved in controlling calpain expression, mainly involving p38/mitogen-activated protein kinase and calcineurin, as well as how calpain regulates the expression of proteins involved in astroglial reactivity through calcineurin and cyclin-dependent kinase 5. Throughout the text, we have tried to provide evidence of the connection between the alterations caused by calpain and the metabolic changes associated with AD. In addition, we discuss the possibility that calpain mediates amyloid-β clearance in astrocytes, as opposed to amyloid-β accumulation in neurons.
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Affiliation(s)
- Bruna Schultz
- Postgraduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Jéssica Taday
- Postgraduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Leonardo Menezes
- Postgraduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Anderson Cigerce
- Postgraduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Marina C Leite
- Postgraduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlos-Alberto Gonçalves
- Postgraduate Program in Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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13
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Cioffi F, Adam RHI, Bansal R, Broersen K. A Review of Oxidative Stress Products and Related Genes in Early Alzheimer's Disease. J Alzheimers Dis 2021; 83:977-1001. [PMID: 34420962 PMCID: PMC8543250 DOI: 10.3233/jad-210497] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oxidative stress is associated with the progression of Alzheimer’s disease (AD). Reactive oxygen species can modify lipids, DNA, RNA, and proteins in the brain. The products of their peroxidation and oxidation are readily detectable at incipient stages of disease. Based on these oxidation products, various biomarker-based strategies have been developed to identify oxidative stress levels in AD. Known oxidative stress-related biomarkers include lipid peroxidation products F2-isoprostanes, as well as malondialdehyde and 4-hydroxynonenal which both conjugate to specific amino acids to modify proteins, and DNA or RNA oxidation products 8-hydroxy-2’-deoxyguanosine (8-OHdG) and 8-hydroxyguanosine (8-OHG), respectively. The inducible enzyme heme oxygenase type 1 (HO-1) is found to be upregulated in response to oxidative stress-related events in the AD brain. While these global biomarkers for oxidative stress are associated with early-stage AD, they generally poorly differentiate from other neurodegenerative disorders that also coincide with oxidative stress. Redox proteomics approaches provided specificity of oxidative stress-associated biomarkers to AD pathology by the identification of oxidatively damaged pathology-specific proteins. In this review, we discuss the potential combined diagnostic value of these reported biomarkers in the context of AD and discuss eight oxidative stress-related mRNA biomarkers in AD that we newly identified using a transcriptomics approach. We review these genes in the context of their reported involvement in oxidative stress regulation and specificity for AD. Further research is warranted to establish the protein levels and their functionalities as well as the molecular mechanisms by which these potential biomarkers are involved in regulation of oxidative stress levels and their potential for determination of oxidative stress and disease status of AD patients.
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Affiliation(s)
- Federica Cioffi
- Department of Nanobiophysics, Technical Medical Centre, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Rayan Hassan Ibrahim Adam
- Department of Nanobiophysics, Technical Medical Centre, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Ruchi Bansal
- Department of Medical Cell Biophysics, Technical Medical Centre, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands.,Department of Pharmacokinetics, Toxicology, and Targeting, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Kerensa Broersen
- Department of Applied Stem Cell Technologies, Technical Medical Centre, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
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14
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Price BR, Johnson LA, Norris CM. Reactive astrocytes: The nexus of pathological and clinical hallmarks of Alzheimer's disease. Ageing Res Rev 2021; 68:101335. [PMID: 33812051 PMCID: PMC8168445 DOI: 10.1016/j.arr.2021.101335] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/21/2021] [Accepted: 03/20/2021] [Indexed: 02/06/2023]
Abstract
Astrocyte reactivity is a hallmark of neuroinflammation that arises with Alzheimer’s disease (AD) and nearly every other neurodegenerative condition. While astrocytes certainly contribute to classic inflammatory processes (e.g. cytokine release, waste clearance, and tissue repair), newly emerging technologies for measuring and targeting cell specific activities in the brain have uncovered essential roles for astrocytes in synapse function, brain metabolism, neurovascular coupling, and sleep/wake patterns. In this review, we use a holistic approach to incorporate, and expand upon, classic neuroinflammatory concepts to consider how astrocyte dysfunction/reactivity modulates multiple pathological and clinical hallmarks of AD. Our ever-evolving understanding of astrocyte signaling in neurodegeneration is not only revealing new drug targets and treatments for dementia but is suggesting we reimagine AD pathophysiological mechanisms.
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Affiliation(s)
- Brittani R Price
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA, 02111, USA
| | - Lance A Johnson
- Sanders-Brown Center on Aging, University of Kentucky, 800 S. Limestone St., Lexington, KY, 40356, USA; Department of Physiology, University of Kentucky, College of Medicine, UK Medical Center MN 150, Lexington, KY, 40536, USA
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky, 800 S. Limestone St., Lexington, KY, 40356, USA; Department of Pharmacology and Nutritional Sciences, University of Kentucky, College of Medicine, UK Medical Center MN 150, Lexington, KY, 40536, USA.
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15
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Radhakrishnan H, Ubele MF, Krumholz SM, Boaz K, Mefford JL, Jones ED, Meacham B, Smiley J, Puskás LG, Powell DK, Norris CM, Stark CEL, Head E. Tacrolimus Protects against Age-Associated Microstructural Changes in the Beagle Brain. J Neurosci 2021; 41:5124-5133. [PMID: 33952632 PMCID: PMC8197636 DOI: 10.1523/jneurosci.0361-21.2021] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/09/2021] [Accepted: 04/16/2021] [Indexed: 11/21/2022] Open
Abstract
The overexpression of calcineurin leads to astrocyte hyperactivation, neuronal death, and inflammation, which are characteristics often associated with pathologic aging and Alzheimer's disease. In this study, we tested the hypothesis that tacrolimus, a calcineurin inhibitor, prevents age-associated microstructural atrophy, which we measured using higher-order diffusion MRI, in the middle-aged beagle brain (n = 30, male and female). We find that tacrolimus reduces hippocampal (p = 0.001) and parahippocampal (p = 0.002) neurite density index, as well as protects against an age-associated increase in the parahippocampal (p = 0.007) orientation dispersion index. Tacrolimus also protects against an age-related decrease in fractional anisotropy in the prefrontal cortex (p < 0.0001). We also show that these microstructural alterations precede cognitive decline and gross atrophy. These results support the idea that calcineurin inhibitors may have the potential to prevent aging-related pathology if administered at middle age.SIGNIFICANCE STATEMENT Hyperactive calcineurin signaling causes neuroinflammation and other neurobiological changes often associated with pathologic aging and Alzheimer's disease (AD). Controlling the expression of calcineurin before gross cognitive deficits are observable might serve as a promising avenue for preventing AD pathology. In this study, we show that the administration of the calcineurin inhibitor, tacrolimus, over 1 year prevents age- and AD-associated microstructural changes in the hippocampus, parahippocampal cortex, and prefrontal cortex of the middle-aged beagle brain, with no noticeable adverse effects. Tacrolimus is already approved by the Food and Drug Administration for use in humans to prevent solid organ transplant rejection, and our results bolster the promise of this drug to prevent AD and aging-related pathology.
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Affiliation(s)
- Hamsanandini Radhakrishnan
- Mathematical, Computational and Systems Biology, University of California, Irvine, Irvine, California 92697
| | - Margo F Ubele
- Sanders Brown Center on Aging, Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, Kentucky 40506
| | - Stephanie M Krumholz
- Sanders Brown Center on Aging, Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, Kentucky 40506
| | - Kathy Boaz
- Sanders Brown Center on Aging, Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, Kentucky 40506
| | - Jennifer L Mefford
- Division of Laboratory Animal Resources, University of Kentucky, Lexington, Kentucky 40506
| | - Erin Denhart Jones
- Division of Laboratory Animal Resources, University of Kentucky, Lexington, Kentucky 40506
| | - Beverly Meacham
- Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, Kentucky 40506
| | - Jeffrey Smiley
- Division of Laboratory Animal Resources, University of Kentucky, Lexington, Kentucky 40506
| | | | - David K Powell
- Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, Kentucky 40506
| | - Christopher M Norris
- Sanders Brown Center on Aging, Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, Kentucky 40506
| | - Craig E L Stark
- Mathematical, Computational and Systems Biology, University of California, Irvine, Irvine, California 92697
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, California 92697
| | - Elizabeth Head
- Department of Pathology & Laboratory Medicine, University of California, Irvine, Irvine, California 92697
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16
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Li L, Lai M, Cole S, Le Novère N, Edelstein SJ. Neurogranin stimulates Ca2+/calmodulin-dependent kinase II by suppressing calcineurin activity at specific calcium spike frequencies. PLoS Comput Biol 2020; 16:e1006991. [PMID: 32049957 PMCID: PMC7041932 DOI: 10.1371/journal.pcbi.1006991] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 02/25/2020] [Accepted: 11/18/2019] [Indexed: 11/18/2022] Open
Abstract
Calmodulin sits at the center of molecular mechanisms underlying learning and memory. Its complex and sometimes opposite influences, mediated via the binding to various proteins, are yet to be fully understood. Calcium/calmodulin-dependent protein kinase II (CaMKII) and calcineurin (CaN) both bind open calmodulin, favoring Long-Term Potentiation (LTP) or Depression (LTD) respectively. Neurogranin binds to the closed conformation of calmodulin and its impact on synaptic plasticity is less clear. We set up a mechanistic computational model based on allosteric principles to simulate calmodulin state transitions and its interactions with calcium ions and the three binding partners mentioned above. We simulated calcium spikes at various frequencies and show that neurogranin regulates synaptic plasticity along three modalities. At low spike frequencies, neurogranin inhibits the onset of LTD by limiting CaN activation. At intermediate frequencies, neurogranin facilitates LTD, but limits LTP by precluding binding of CaMKII with calmodulin. Finally, at high spike frequencies, neurogranin promotes LTP by enhancing CaMKII autophosphorylation. While neurogranin might act as a calmodulin buffer, it does not significantly preclude the calmodulin opening by calcium. On the contrary, neurogranin synchronizes the opening of calmodulin's two lobes and promotes their activation at specific frequencies. Neurogranin suppresses basal CaN activity, thus increasing the chance of CaMKII trans-autophosphorylation at high-frequency calcium spikes. Taken together, our study reveals dynamic regulatory roles played by neurogranin on synaptic plasticity, which provide mechanistic explanations for opposing experimental findings.
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Affiliation(s)
- Lu Li
- Babraham Institute, Cambridge, United Kingdom
| | - Massimo Lai
- Quantitative Systems Pharmacology, CERTARA, Canterbury, United Kingdom
| | - Stephen Cole
- Cambridge Systems Biology Centre, University of Cambridge, Cambridge, United Kingdom
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17
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dos Santos JPA, Vizuete AF, Gonçalves CA. Calcineurin-Mediated Hippocampal Inflammatory Alterations in Streptozotocin-Induced Model of Dementia. Mol Neurobiol 2019; 57:502-512. [DOI: 10.1007/s12035-019-01718-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/23/2019] [Indexed: 01/26/2023]
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18
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Norris CM. Calcineurin: directing the damage in Alzheimer disease: An Editorial for 'Neuronal calcineurin transcriptional targets parallel changes observed in Alzheimer disease brain' on page 24. J Neurochem 2018; 147:8-11. [PMID: 30256415 PMCID: PMC6181764 DOI: 10.1111/jnc.14475] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 12/23/2022]
Abstract
Ca2+ dysregulation is a hallmark of Alzheimer disease (AD) and affects numerous and diverse signaling cascades linked to neurodegeneration and cognitive decline. Increasing evidence suggests that the protein phosphatase calcineurin (CN) mediates or exacerbates AD pathophysiology through activation of the NFAT family of transcription factors. In this editorial, we discuss work by Hopp et al, , which uncovered a novel role of CN/NFAT signaling in controlling global gene expression in hippocampal neurons of intact mice. Interestingly, the authors showed that elevated CN expression/activity in neurons plays a major role in transcriptional suppression. Many of the genes differentially affected by CN were related to synapse function and NFAT binding, and exhibited similar patterns of downregulation in previous studies on human AD biospecimens. Results are discussed in context with emerging roles for CN/NFATs in astrocyte signaling as they pertain to Ca2+ dysregulation and the progression of neurodegeneration and cognitive loss with AD.
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Affiliation(s)
- Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, Kentucky, USA
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19
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Hopp SC, Bihlmeyer NA, Corradi JP, Vanderburg C, Cacace AM, Das S, Clark TW, Betensky RA, Hyman BT, Hudry E. Neuronal calcineurin transcriptional targets parallel changes observed in Alzheimer disease brain. J Neurochem 2018; 147:24-39. [PMID: 29806693 DOI: 10.1111/jnc.14469] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/11/2018] [Accepted: 05/09/2018] [Indexed: 01/23/2023]
Abstract
Synaptic dysfunction and loss are core pathological features in Alzheimer disease (AD). In the vicinity of amyloid-β plaques in animal models, synaptic toxicity occurs and is associated with chronic activation of the phosphatase calcineurin (CN). Indeed, pharmacological inhibition of CN blocks amyloid-β synaptotoxicity. We therefore hypothesized that CN-mediated transcriptional changes may contribute to AD neuropathology and tested this by examining the impact of CN over-expression on neuronal gene expression in vivo. We found dramatic transcriptional down-regulation, especially of synaptic mRNAs, in neurons chronically exposed to CN activation. Importantly, the transcriptional profile parallels the changes in human AD tissue. Bioinformatics analyses suggest that both nuclear factor of activated T cells and numerous microRNAs may all be impacted by CN, and parallel findings are observed in AD. These data and analyses support the hypothesis that at least part of the synaptic failure characterizing AD may result from aberrant CN activation leading to down-regulation of synaptic genes, potentially via activation of specific transcription factors and expression of repressive microRNAs. OPEN PRACTICES Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/ Read the Editorial Highlight for this article on page 8.
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Affiliation(s)
- Sarah C Hopp
- Alzheimer's disease Research Laboratory, Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Nathan A Bihlmeyer
- MIND Informatics, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Cambridge, Massachusetts, USA
| | - John P Corradi
- Exploratory Biology and Genomics, Bristol-Myers Squibb, Wallingford, Connecticut, USA
| | - Charles Vanderburg
- Alzheimer's disease Research Laboratory, Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Angela M Cacace
- Exploratory Biology and Genomics, Bristol-Myers Squibb, Wallingford, Connecticut, USA
| | - Sudeshna Das
- MIND Informatics, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Cambridge, Massachusetts, USA
| | - Timothy W Clark
- MIND Informatics, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Cambridge, Massachusetts, USA
| | - Rebecca A Betensky
- Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Bradley T Hyman
- Alzheimer's disease Research Laboratory, Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Eloise Hudry
- Alzheimer's disease Research Laboratory, Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
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20
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Sompol P, Norris CM. Ca 2+, Astrocyte Activation and Calcineurin/NFAT Signaling in Age-Related Neurodegenerative Diseases. Front Aging Neurosci 2018; 10:199. [PMID: 30038565 PMCID: PMC6046440 DOI: 10.3389/fnagi.2018.00199] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/12/2018] [Indexed: 12/12/2022] Open
Abstract
Mounting evidence supports a fundamental role for Ca2+ dysregulation in astrocyte activation. Though the activated astrocyte phenotype is complex, cell-type targeting approaches have revealed a number of detrimental roles of activated astrocytes involving neuroinflammation, release of synaptotoxic factors and loss of glutamate regulation. Work from our lab and others has suggested that the Ca2+/calmodulin dependent protein phosphatase, calcineurin (CN), provides a critical link between Ca2+ dysregulation and the activated astrocyte phenotype. A proteolyzed, hyperactivated form of CN appears at high levels in activated astrocytes in both human tissue and rodent tissue around regions of amyloid and vascular pathology. Similar upregulation of the CN-dependent transcription factor nuclear factor of activated T cells (NFAT4) also appears in activated astrocytes in mouse models of Alzheimer's disease (ADs) and traumatic brain injury (TBI). Major consequences of hyperactivated CN/NFAT4 signaling in astrocytes are neuroinflammation, synapse dysfunction and glutamate dysregulation/excitotoxicity, which will be covered in this review article.
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Affiliation(s)
- Pradoldej Sompol
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States.,Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
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21
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Castonguay D, Dufort-Gervais J, Ménard C, Chatterjee M, Quirion R, Bontempi B, Schneider JS, Arnsten AFT, Nairn AC, Norris CM, Ferland G, Bézard E, Gaudreau P, Lombroso PJ, Brouillette J. The Tyrosine Phosphatase STEP Is Involved in Age-Related Memory Decline. Curr Biol 2018; 28:1079-1089.e4. [PMID: 29576474 DOI: 10.1016/j.cub.2018.02.047] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/27/2017] [Accepted: 02/19/2018] [Indexed: 01/22/2023]
Abstract
Cognitive disabilities that occur with age represent a growing and expensive health problem. Age-associated memory deficits are observed across many species, but the underlying molecular mechanisms remain to be fully identified. Here, we report elevations in the levels and activity of the striatal-enriched phosphatase (STEP) in the hippocampus of aged memory-impaired mice and rats, in aged rhesus monkeys, and in people diagnosed with amnestic mild cognitive impairment (aMCI). The accumulation of STEP with aging is related to dysfunction of the ubiquitin-proteasome system that normally leads to the degradation of STEP. Higher level of active STEP is linked to enhanced dephosphorylation of its substrates GluN2B and ERK1/2, CREB inactivation, and a decrease in total levels of GluN2B and brain-derived neurotrophic factor (BDNF). These molecular events are reversed in aged STEP knockout and heterozygous mice, which perform similarly to young control mice in the Morris water maze (MWM) and Y-maze tasks. In addition, administration of the STEP inhibitor TC-2153 to old rats significantly improved performance in a delayed alternation T-maze memory task. In contrast, viral-mediated STEP overexpression in the hippocampus is sufficient to induce memory impairment in the MWM and Y-maze tests, and these cognitive deficits are reversed by STEP inhibition. In old LOU/C/Jall rats, a model of healthy aging with preserved memory capacities, levels of STEP and GluN2B are stable, and phosphorylation of GluN2B and ERK1/2 is unaltered. Altogether, these data suggest that elevated levels of STEP that appear with advancing age in several species contribute to the cognitive declines associated with aging.
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Affiliation(s)
- David Castonguay
- Department of Pharmacology and Physiology, Université de Montréal, and Hôpital du Sacré-Coeur de Montréal Research Center, Montreal, QC, Canada
| | - Julien Dufort-Gervais
- Department of Pharmacology and Physiology, Université de Montréal, and Hôpital du Sacré-Coeur de Montréal Research Center, Montreal, QC, Canada
| | - Caroline Ménard
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada; Department of Medecine, Université de Montréal, Centre Hospitalier de l'Université de Montréal Research Center, Montreal, QC, Canada
| | - Manavi Chatterjee
- Child Study Center, Yale University School of Medicine, New Haven, CT, USA
| | - Rémi Quirion
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada
| | - Bruno Bontempi
- Université de Bordeaux, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Jay S Schneider
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Amy F T Arnsten
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Angus C Nairn
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Christopher M Norris
- Department of Molecular and Biomedical Pharmacology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Guylaine Ferland
- Department of Nutrition, Université de Montréal, and Institut de Cardiologie de Montréal, Montreal, QC, Canada
| | - Erwan Bézard
- Université de Bordeaux, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Pierrette Gaudreau
- Department of Medecine, Université de Montréal, Centre Hospitalier de l'Université de Montréal Research Center, Montreal, QC, Canada
| | - Paul J Lombroso
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Child Study Center, Yale University School of Medicine, New Haven, CT, USA.
| | - Jonathan Brouillette
- Department of Pharmacology and Physiology, Université de Montréal, and Hôpital du Sacré-Coeur de Montréal Research Center, Montreal, QC, Canada; Child Study Center, Yale University School of Medicine, New Haven, CT, USA.
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AD-Related N-Terminal Truncated Tau Is Sufficient to Recapitulate In Vivo the Early Perturbations of Human Neuropathology: Implications for Immunotherapy. Mol Neurobiol 2018; 55:8124-8153. [PMID: 29508283 DOI: 10.1007/s12035-018-0974-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/19/2018] [Indexed: 01/08/2023]
Abstract
The NH2tau 26-44 aa (i.e., NH2htau) is the minimal biologically active moiety of longer 20-22-kDa NH2-truncated form of human tau-a neurotoxic fragment mapping between 26 and 230 amino acids of full-length protein (htau40)-which is detectable in presynaptic terminals and peripheral CSF from patients suffering from AD and other non-AD neurodegenerative diseases. Nevertheless, whether its exogenous administration in healthy nontransgenic mice is able to elicit a neuropathological phenotype resembling human tauopathies has not been yet investigated. We explored the in vivo effects evoked by subchronic intracerebroventricular (i.c.v.) infusion of NH2htau or its reverse counterpart into two lines of young (2-month-old) wild-type mice (C57BL/6 and B6SJL). Six days after its accumulation into hippocampal parenchyma, significant impairment in memory/learning performance was detected in NH2htau-treated group in association with reduced synaptic connectivity and neuroinflammatory response. Compromised short-term plasticity in paired-pulse facilitation paradigm (PPF) was detected in the CA3/CA1 synapses from NH2htau-impaired animals along with downregulation in calcineurin (CaN)-stimulated pCREB/c-Fos pathway(s). Importantly, these behavioral, synaptotoxic, and neuropathological effects were independent from the genetic background, occurred prior to frank neuronal loss, and were specific because no alterations were detected in the control group infused with its reverse counterpart. Finally, a 2.0-kDa peptide which biochemically and immunologically resembles the injected NH2htau was endogenously detected in vivo, being present in hippocampal synaptosomal preparations from AD subjects. Given that the identification of the neurotoxic tau species is mandatory to develop a more effective tau-based immunological approach, our evidence can have important translational implications for cure of human tauopathies.
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23
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Calcineurin/NFAT Signaling in Activated Astrocytes Drives Network Hyperexcitability in Aβ-Bearing Mice. J Neurosci 2017; 37:6132-6148. [PMID: 28559377 DOI: 10.1523/jneurosci.0877-17.2017] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/12/2017] [Accepted: 05/16/2017] [Indexed: 12/25/2022] Open
Abstract
Hyperexcitable neuronal networks are mechanistically linked to the pathologic and clinical features of Alzheimer's disease (AD). Astrocytes are a primary defense against hyperexcitability, but their functional phenotype during AD is poorly understood. Here, we found that activated astrocytes in the 5xFAD mouse model were strongly associated with proteolysis of the protein phosphatase calcineurin (CN) and the elevated expression of the CN-dependent transcription factor nuclear factor of activated T cells 4 (NFAT4). Intrahippocampal injections of adeno-associated virus vectors containing the astrocyte-specific promoter Gfa2 and the NFAT inhibitory peptide VIVIT reduced signs of glutamate-mediated hyperexcitability in 5xFAD mice, measured in vivo with microelectrode arrays and ex vivo brain slices, using whole-cell voltage clamp. VIVIT treatment in 5xFAD mice led to increased expression of the astrocytic glutamate transporter GLT-1 and to attenuated changes in dendrite morphology, synaptic strength, and NMDAR-dependent responses. The results reveal astrocytic CN/NFAT4 as a key pathologic mechanism for driving glutamate dysregulation and neuronal hyperactivity during AD.SIGNIFICANCE STATEMENT Neuronal hyperexcitability and excitotoxicity are increasingly recognized as important mechanisms for neurodegeneration and dementia associated with Alzheimer's disease (AD). Astrocytes are profoundly activated during AD and may lose their capacity to regulate excitotoxic glutamate levels. Here, we show that a highly active calcineurin (CN) phosphatase fragment and its substrate transcription factor, nuclear factor of activated T cells (NFAT4), appear in astrocytes in direct proportion to the extent of astrocyte activation. The blockade of astrocytic CN/NFAT signaling in a common mouse model of AD, using adeno-associated virus vectors normalized glutamate signaling dynamics, increased astrocytic glutamate transporter levels and alleviated multiple signs of neuronal hyperexcitability. The results suggest that astrocyte activation drives hyperexcitability during AD through a mechanism involving aberrant CN/NFAT signaling and impaired glutamate transport.
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Popugaeva E, Pchitskaya E, Bezprozvanny I. Dysregulation of neuronal calcium homeostasis in Alzheimer's disease - A therapeutic opportunity? Biochem Biophys Res Commun 2016; 483:998-1004. [PMID: 27641664 DOI: 10.1016/j.bbrc.2016.09.053] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 09/12/2016] [Indexed: 10/21/2022]
Abstract
Alzheimer's disease (AD) is the disease of lost memories. Synaptic loss is a major reason for memory defects in AD. Signaling pathways involved in memory loss in AD are under intense investigation. The role of deranged neuronal calcium (Ca2+) signaling in synaptic loss in AD is described in this review. Familial AD (FAD) mutations in presenilins are linked directly with synaptic Ca2+ signaling abnormalities, most likely by affecting endoplasmic reticulum (ER) Ca2+ leak function of presenilins. Excessive ER Ca2+ release via type 2 ryanodine receptors (RyanR2) is observed in AD spines due to increase in expression and function of RyanR2. Store-operated Ca2+ entry (nSOC) pathway is disrupted in AD spines due to downregulation of STIM2 protein. Because of these Ca2+ signaling abnormalities, a balance in activities of Ca2+-calmodulin-dependent kinase II (CaMKII) and Ca2+-dependent phosphatase calcineurin (CaN) is shifted at the synapse, tilting a balance between long-term potentiation (LTP) and long-term depression (LTD) synaptic mechanisms. As a result, synapses are weakened and eliminated in AD brains by LTD mechanism, causing memory loss. Targeting synaptic calcium signaling pathways offers opportunity for development of AD therapeutic agents.
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Affiliation(s)
- Elena Popugaeva
- Laboratory of Molecular Neurodegeneration, Department of Medical Physics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russian Federation.
| | - Ekaterina Pchitskaya
- Laboratory of Molecular Neurodegeneration, Department of Medical Physics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russian Federation.
| | - Ilya Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Department of Medical Physics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russian Federation; Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX, USA.
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Blockade of Astrocytic Calcineurin/NFAT Signaling Helps to Normalize Hippocampal Synaptic Function and Plasticity in a Rat Model of Traumatic Brain Injury. J Neurosci 2016; 36:1502-15. [PMID: 26843634 DOI: 10.1523/jneurosci.1930-15.2016] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED Increasing evidence suggests that the calcineurin (CN)-dependent transcription factor NFAT (Nuclear Factor of Activated T cells) mediates deleterious effects of astrocytes in progressive neurodegenerative conditions. However, the impact of astrocytic CN/NFAT signaling on neural function/recovery after acute injury has not been investigated extensively. Using a controlled cortical impact (CCI) procedure in rats, we show that traumatic brain injury is associated with an increase in the activities of NFATs 1 and 4 in the hippocampus at 7 d after injury. NFAT4, but not NFAT1, exhibited extensive labeling in astrocytes and was found throughout the axon/dendrite layers of CA1 and the dentate gyrus. Blockade of the astrocytic CN/NFAT pathway in rats using adeno-associated virus (AAV) vectors expressing the astrocyte-specific promoter Gfa2 and the NFAT-inhibitory peptide VIVIT prevented the injury-related loss of basal CA1 synaptic strength and key synaptic proteins and reduced the susceptibility to induction of long-term depression. In conjunction with these seemingly beneficial effects, VIVIT treatment elicited a marked increase in the expression of the prosynaptogenic factor SPARCL1 (hevin), especially in hippocampal tissue ipsilateral to the CCI injury. However, in contrast to previous work on Alzheimer's mouse models, AAV-Gfa2-VIVIT had no effects on the levels of GFAP and Iba1, suggesting that synaptic benefits of VIVIT were not attributable to a reduction in glial activation per se. Together, the results implicate the astrocytic CN/NFAT4 pathway as a key mechanism for disrupting synaptic remodeling and homeostasis in the hippocampus after acute injury. SIGNIFICANCE STATEMENT Similar to microglia, astrocytes become strongly "activated" with neural damage and exhibit numerous morphologic/biochemical changes, including an increase in the expression/activity of the protein phosphatase calcineurin. Using adeno-associated virus (AAV) to inhibit the calcineurin-dependent activation of the transcription factor NFAT (Nuclear Factor of Activated T cells) selectively, we have shown that activated astrocytes contribute to neural dysfunction in animal models characterized by progressive/chronic neuropathology. Here, we show that the suppression of astrocytic calcineurin/NFATs helps to protect synaptic function and plasticity in an animal model in which pathology arises from a single traumatic brain injury. The findings suggest that at least some astrocyte functions impair recovery after trauma and may provide druggable targets for treating victims of acute nervous system injury.
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Tau accumulation induces synaptic impairment and memory deficit by calcineurin-mediated inactivation of nuclear CaMKIV/CREB signaling. Proc Natl Acad Sci U S A 2016; 113:E3773-81. [PMID: 27298345 DOI: 10.1073/pnas.1604519113] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Intracellular accumulation of wild-type tau is a hallmark of sporadic Alzheimer's disease (AD), but the molecular mechanisms underlying tau-induced synapse impairment and memory deficit are poorly understood. Here we found that overexpression of human wild-type full-length tau (termed hTau) induced memory deficits with impairments of synaptic plasticity. Both in vivo and in vitro data demonstrated that hTau accumulation caused remarkable dephosphorylation of cAMP response element binding protein (CREB) in the nuclear fraction. Simultaneously, the calcium-dependent protein phosphatase calcineurin (CaN) was up-regulated, whereas the calcium/calmodulin-dependent protein kinase IV (CaMKIV) was suppressed. Further studies revealed that CaN activation could dephosphorylate CREB and CaMKIV, and the effect of CaN on CREB dephosphorylation was independent of CaMKIV inhibition. Finally, inhibition of CaN attenuated the hTau-induced CREB dephosphorylation with improved synapse and memory functions. Together, these data indicate that the hTau accumulation impairs synapse and memory by CaN-mediated suppression of nuclear CaMKIV/CREB signaling. Our findings not only reveal new mechanisms underlying the hTau-induced synaptic toxicity, but also provide potential targets for rescuing tauopathies.
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Pleiss MM, Sompol P, Kraner SD, Abdul HM, Furman JL, Guttmann RP, Wilcock DM, Nelson PT, Norris CM. Calcineurin proteolysis in astrocytes: Implications for impaired synaptic function. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1521-32. [PMID: 27212416 DOI: 10.1016/j.bbadis.2016.05.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 05/14/2016] [Accepted: 05/16/2016] [Indexed: 01/01/2023]
Abstract
Mounting evidence suggests that astrocyte activation, found in most forms of neural injury and disease, is linked to the hyperactivation of the protein phosphatase calcineurin. In many tissues and cell types, calcineurin hyperactivity is the direct result of limited proteolysis. However, little is known about the proteolytic status of calcineurin in activated astrocytes. Here, we developed a polyclonal antibody to a high activity calcineurin proteolytic fragment in the 45-48kDa range (ΔCN) for use in immunohistochemical applications. When applied to postmortem human brain sections, the ΔCN antibody intensely labeled cell clusters in close juxtaposition to amyloid deposits and microinfarcts. Many of these cells exhibited clear activated astrocyte morphology. The expression of ΔCN in astrocytes near areas of pathology was further confirmed using confocal microscopy. Multiple NeuN-positive cells, particularly those within microinfarct core regions, also labeled positively for ΔCN. This observation suggests that calcineurin proteolysis can also occur within damaged or dying neurons, as reported in other studies. When a similar ΔCN fragment was selectively expressed in hippocampal astrocytes of intact rats (using adeno-associated virus), we observed a significant reduction in the strength of CA3-CA1 excitatory synapses, indicating that the hyperactivation of astrocytic calcineurin is sufficient for disrupting synaptic function. Together, these results suggest that proteolytic activation of calcineurin in activated astrocytes may be a central mechanism for driving and/or exacerbating neural dysfunction during neurodegenerative disease and injury.
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Affiliation(s)
- Melanie M Pleiss
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Pradoldej Sompol
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Susan D Kraner
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Hafiz Mohmmad Abdul
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Jennifer L Furman
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Rodney P Guttmann
- Department of Psychology, University of West Florida, Pensacola, FL, USA.
| | - Donna M Wilcock
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Peter T Nelson
- Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA; Department of Pathology and Laboratory Medicine, University of Kentucky College of Medicine, Lexington, KY, USA.
| | - Christopher M Norris
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA; Sanders Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, USA.
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Ding F, Li X, Li B, Guo J, Zhang Y, Ding J. Calpain-Mediated Cleavage of Calcineurin in Puromycin Aminonucleoside-Induced Podocyte Injury. PLoS One 2016; 11:e0155504. [PMID: 27171192 PMCID: PMC4865207 DOI: 10.1371/journal.pone.0155504] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 04/30/2016] [Indexed: 11/18/2022] Open
Abstract
The calcineurin inhibitors cyclosporine A (CsA) and tacrolimus are widely used in the treatment of proteinuria diseases. As the direct target of these drugs, calcineurin has previously been demonstrated to play a role in proteinuria diseases. However, aside from its immune-related effects, the local status of calcineurin in renal inherent cells has not been fully explored in the settings of proteinuria disease and podocyte injury. In this study, calcineurin activity and protein expression in the well-known puromycin aminonucleoside (PAN)-induced podocyte injury model were examined. Interestingly, we found that calcineurin activity was abnormally increased in PAN-treated podocytes, whereas the expression of the full-length 60-kDa calcineurin protein was decreased. This result suggests that there may be another activated form of calcineurin that is independent of the full-length phosphatase. To investigate whether calpain is involved in regulating calcineurin, we exposed PAN-treated podocytes to both pharmacological inhibitors of calpain and specific siRNAs against calpain. Calpain blockade reduced the enhanced calcineurin activity and restored the down-regulated expression of 60-kDa calcineurin. In addition, purified calpain protein was incubated with podocyte extracts, and a 45-kDa fragment of calcineurin was identified; this finding was confirmed in PAN-induced podocyte injury and calpain inhibition experiments. We conclude that calcineurin activity is abnormally increased during PAN-induced podocyte injury, whereas the expression of the full-length 60-kDa calcineurin protein is down-regulated due to over-activated calpain that cleaves calcineurin to form a 45-kDa fragment.
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Affiliation(s)
- Fangrui Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xuejuan Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Baihong Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jifan Guo
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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Kurbatskaya K, Phillips EC, Croft CL, Dentoni G, Hughes MM, Wade MA, Al-Sarraj S, Troakes C, O’Neill MJ, Perez-Nievas BG, Hanger DP, Noble W. Upregulation of calpain activity precedes tau phosphorylation and loss of synaptic proteins in Alzheimer's disease brain. Acta Neuropathol Commun 2016; 4:34. [PMID: 27036949 PMCID: PMC4818436 DOI: 10.1186/s40478-016-0299-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/15/2016] [Indexed: 12/05/2022] Open
Abstract
Alterations in calcium homeostasis are widely reported to contribute to synaptic degeneration and neuronal loss in Alzheimer’s disease. Elevated cytosolic calcium concentrations lead to activation of the calcium-sensitive cysteine protease, calpain, which has a number of substrates known to be abnormally regulated in disease. Analysis of human brain has shown that calpain activity is elevated in AD compared to controls, and that calpain-mediated proteolysis regulates the activity of important disease-associated proteins including the tau kinases cyclin-dependent kinase 5 and glycogen kinase synthase-3. Here, we sought to investigate the likely temporal association between these changes during the development of sporadic AD using Braak staged post-mortem brain. Quantification of protein amounts in these tissues showed increased activity of calpain-1 from Braak stage III onwards in comparison to controls, extending previous findings that calpain-1 is upregulated at end-stage disease, and suggesting that activation of calcium-sensitive signalling pathways are sustained from early stages of disease development. Increases in calpain-1 activity were associated with elevated activity of the endogenous calpain inhibitor, calpastatin, itself a known calpain substrate. Activation of the tau kinases, glycogen-kinase synthase-3 and cyclin-dependent kinase 5 were also found to occur in Braak stage II-III brain, and these preceded global elevations in tau phosphorylation and the loss of post-synaptic markers. In addition, we identified transient increases in total amyloid precursor protein and pre-synaptic markers in Braak stage II-III brain, that were lost by end stage Alzheimer's disease, that may be indicative of endogenous compensatory responses to the initial stages of neurodegeneration. These findings provide insight into the molecular events that underpin the progression of Alzheimer's disease, and further highlight the rationale for investigating novel treatment strategies that are based on preventing abnormal calcium homeostasis or blocking increases in the activity of calpain or important calpain substrates.
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Watanabe K, Uemura K, Asada M, Maesako M, Akiyama H, Shimohama S, Takahashi R, Kinoshita A. The participation of insulin-like growth factor-binding protein 3 released by astrocytes in the pathology of Alzheimer's disease. Mol Brain 2015; 8:82. [PMID: 26637371 PMCID: PMC4670528 DOI: 10.1186/s13041-015-0174-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 11/30/2015] [Indexed: 01/02/2023] Open
Abstract
Background Alzheimer’s disease (AD) is characterized by senile plaques, extracellular deposits composed primarily of amyloid–beta (Aβ), and neurofibrillary tangles, which are abnormal intracellular inclusions containing hyperphosphorylated tau. The amyloid cascade hypothesis posits that the deposition of Aβ in the brain parenchyma initiates a sequence of events that leads to dementia. However, the molecular process by which the extracellular accumulation of Aβ peptides promotes intracellular pathologic changes in tau filaments remains unclear. To elucidate this process, we presumed that astrocytes might trigger neuronal reactions, leading to tau phosphorylation. In this study, we examined AD pathology from the perspective of the astrocyte-neuron interaction. Results A cytokine-array analysis revealed that Aβ stimulates astrocytes to release several chemical mediators that are primarily related to inflammation and cell adhesion. Among those mediators, insulin-like growth factor (IGF)-binding protein 3 (IGFBP-3) was highly upregulated. In AD brains, the expression of IGFBP-3 was found to be increased by western blot analysis, and increased expression of IGFBP-3 was observed in astrocytes via fluorescence microscopy. In addition, we reproduced the increase in IGFBP-3 after treatment with Aβ using human astrocytoma cell lines and found that IGFBP-3 was expressed via calcineurin. In AD brains, the activated forms of calcineurin were found to be increased by western blot analysis, and increased expression of calcineurin was observed in astrocytes via fluorescence microscopy. When Ser9 of glycogen synthase kinase-3β (GSK-3β) is phosphorylated, GSK-3β is controlled and tau phosphorylation is suppressed. Aβ suppresses the phosphorylation of GSK-3β, leading to tau phosphorylation. In this study, we found that IGF-Ι suppressed tau phosphorylation induced by Aβ, although IGFBP-3 inhibited this property of IGF-Ι. As a result, IGFBP-3 contributed to tau phosphorylation and cell death induced by Aβ. Conclusions Our study suggested that calcineurin in astrocytes was activated by Aβ, leading to IGFBP-3 release. We further demonstrated that IGFBP-3 produced by astrocytes induced tau phosphorylation in neurons. Our study provides novel insights into the role of astrocytes in the induction of tau phosphorylation and suggests that IGFBP-3 could be an important link between Aβ and tau pathology and an important therapeutic target. Electronic supplementary material The online version of this article (doi:10.1186/s13041-015-0174-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kiwamu Watanabe
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Kengo Uemura
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Megumi Asada
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan. .,School of Human Health Sciences Faculty of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Masato Maesako
- School of Human Health Sciences Faculty of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Haruhiko Akiyama
- Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
| | - Shun Shimohama
- Department of Neurology, Sapporo Medical University School of Medicine, 16 Minami-1-jyo-Nishi, Chuo-ku, Sapporo, 060-8543, Japan.
| | - Ryosuke Takahashi
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Ayae Kinoshita
- School of Human Health Sciences Faculty of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
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Norris CM, Sompol P, Roberts KN, Ansari M, Scheff SW. Pycnogenol protects CA3-CA1 synaptic function in a rat model of traumatic brain injury. Exp Neurol 2015; 276:5-12. [PMID: 26607913 DOI: 10.1016/j.expneurol.2015.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 11/16/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
Abstract
Pycnogenol (PYC) is a patented mix of bioflavonoids with potent anti-oxidant and anti-inflammatory properties. Previously, we showed that PYC administration to rats within hours after a controlled cortical impact (CCI) injury significantly protects against the loss of several synaptic proteins in the hippocampus. Here, we investigated the effects of PYC on CA3-CA1 synaptic function following CCI. Adult Sprague-Dawley rats received an ipsilateral CCI injury followed 15 min later by intravenous injection of saline vehicle or PYC (10 mg/kg). Hippocampal slices from the injured (ipsilateral) and uninjured (contralateral) hemispheres were prepared at seven and fourteen days post-CCI for electrophysiological analyses of CA3-CA1 synaptic function and induction of long-term depression (LTD). Basal synaptic strength was impaired in slices from the ipsilateral, relative to the contralateral, hemisphere at seven days post-CCI and susceptibility to LTD was enhanced in the ipsilateral hemisphere at both post-injury timepoints. No interhemispheric differences in basal synaptic strength or LTD induction were observed in rats treated with PYC. The results show that PYC preserves synaptic function after CCI and provides further rationale for investigating the use of PYC as a therapeutic in humans suffering from neurotrauma.
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Affiliation(s)
- Christopher M Norris
- Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY 40536, United States; Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY 40536, United States.
| | - Pradoldej Sompol
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY 40536, United States.
| | - Kelly N Roberts
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY 40536, United States.
| | - Mubeen Ansari
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY 40536, United States.
| | - Stephen W Scheff
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY 40536, United States; Anatomy and Neurobiology, University of Kentucky, College of Medicine, Lexington, KY 40536, United States.
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The synaptic maintenance problem: membrane recycling, Ca2+ homeostasis and late onset degeneration. Mol Neurodegener 2013; 8:23. [PMID: 23829673 PMCID: PMC3708831 DOI: 10.1186/1750-1326-8-23] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/05/2013] [Indexed: 01/02/2023] Open
Abstract
Most neurons are born with the potential to live for the entire lifespan of the organism. In addition, neurons are highly polarized cells with often long axons, extensively branched dendritic trees and many synaptic contacts. Longevity together with morphological complexity results in a formidable challenge to maintain synapses healthy and functional. This challenge is often evoked to explain adult-onset degeneration in numerous neurodegenerative disorders that result from otherwise divergent causes. However, comparably little is known about the basic cell biological mechanisms that keep normal synapses alive and functional in the first place. How the basic maintenance mechanisms are related to slow adult-onset degeneration in different diseasesis largely unclear. In this review we focus on two basic and interconnected cell biological mechanisms that are required for synaptic maintenance: endomembrane recycling and calcium (Ca2+) homeostasis. We propose that subtle defects in these homeostatic processes can lead to late onset synaptic degeneration. Moreover, the same basic mechanisms are hijacked, impaired or overstimulated in numerous neurodegenerative disorders. Understanding the pathogenesis of these disorders requires an understanding of both the initial cause of the disease and the on-going changes in basic maintenance mechanisms. Here we discuss the mechanisms that keep synapses functional over long periods of time with the emphasis on their role in slow adult-onset neurodegeneration.
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Lim D, Iyer A, Ronco V, Grolla AA, Canonico PL, Aronica E, Genazzani AA. Amyloid beta deregulates astroglial mGluR5-mediated calcium signaling via calcineurin and Nf-kB. Glia 2013; 61:1134-45. [DOI: 10.1002/glia.22502] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 03/05/2013] [Indexed: 12/24/2022]
Affiliation(s)
- Dmitry Lim
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro,”; Novara; Italy
| | - Anand Iyer
- Department of (Neuro)Pathology; Academic Medical Center, University of Amsterdam; Amsterdam; The Netherlands
| | - Virginia Ronco
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro,”; Novara; Italy
| | - Ambra A. Grolla
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro,”; Novara; Italy
| | - Pier Luigi Canonico
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro,”; Novara; Italy
| | | | - Armando A. Genazzani
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro,”; Novara; Italy
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Targeting astrocytes ameliorates neurologic changes in a mouse model of Alzheimer's disease. J Neurosci 2013; 32:16129-40. [PMID: 23152597 DOI: 10.1523/jneurosci.2323-12.2012] [Citation(s) in RCA: 222] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Astrocytes are the most abundant cell type in the brain and play a critical role in maintaining healthy nervous tissue. In Alzheimer's disease (AD) and most other neurodegenerative disorders, many astrocytes convert to a chronically "activated" phenotype characterized by morphologic and biochemical changes that appear to compromise protective properties and/or promote harmful neuroinflammatory processes. Activated astrocytes emerge early in the course of AD and become increasingly prominent as clinical and pathological symptoms progress, but few studies have tested the potential of astrocyte-targeted therapeutics in an intact animal model of AD. Here, we used adeno-associated virus (AAV) vectors containing the astrocyte-specific Gfa2 promoter to target hippocampal astrocytes in APP/PS1 mice. AAV-Gfa2 vectors drove the expression of VIVIT, a peptide that interferes with the immune/inflammatory calcineurin/NFAT (nuclear factor of activated T-cells) signaling pathway, shown by our laboratory and others to orchestrate biochemical cascades leading to astrocyte activation. After several months of treatment with Gfa2-VIVIT, APP/PS1 mice exhibited improved cognitive and synaptic function, reduced glial activation, and lower amyloid levels. The results confirm a deleterious role for activated astrocytes in AD and lay the groundwork for exploration of other novel astrocyte-based therapies.
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Clinkinbeard T, Ghoshal S, Craddock S, Creed Pettigrew L, Guttmann RP. Calpain cleaves methionine aminopeptidase-2 in a rat model of ischemia/reperfusion. Brain Res 2013; 1499:129-35. [PMID: 23295187 DOI: 10.1016/j.brainres.2012.12.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 12/18/2012] [Accepted: 12/28/2012] [Indexed: 10/27/2022]
Abstract
Ischemic stroke results in multiple injurious signals within a cell including dysregulation of calcium homeostasis. Consequently, there is an increase in the enzymatic activity of the calpains, calcium dependent proteases that are thought to contribute to neuronal injury. In addition, cellular stress due to ischemia/reperfusion also triggers a decrease in protein translation through activation of the unfolded protein response (UPR). In the present study we found that methionine aminopeptidase 2 (MetAP2), a critical component of the translation initiation complex, is a calpain substrate. In vitro calpain assays demonstrated that while MetAP2 has autoproteolytic activity, calpain also produces a stable proteolytic fragment at 50kDa using recombinant MetAP2. This 50kDa fragment, in addition to a 57kDa fragment was present in in vitro digestions of rat brain homogenates. Production of these fragments was inhibited by calpastatin, the endogenous and specific inhibitor of calpain. Using an in vivo middle cerebral artery occlusion (MCAO) model only the 57kDa fragment of MetAP2 was observed. These data suggest that calpain activation in stroke may regulate MetAP2-mediated protein translation giving calpains a larger role in the cellular stress response than previously determined.
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Baumgärtel K, Mansuy IM. Neural functions of calcineurin in synaptic plasticity and memory. Learn Mem 2012; 19:375-84. [PMID: 22904368 DOI: 10.1101/lm.027201.112] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Major brain functions depend on neuronal processes that favor the plasticity of neuronal circuits while at the same time maintaining their stability. The mechanisms that regulate brain plasticity are complex and engage multiple cascades of molecular components that modulate synaptic efficacy. Protein kinases (PKs) and phosphatases (PPs) are among the most important of these components that act as positive and negative regulators of neuronal signaling and plasticity, respectively. In these cascades, the PP protein phosphatase 2B or calcineurin (CaN) is of particular interest because it is the only Ca(2+)-activated PP in the brain and a major regulator of key proteins essential for synaptic transmission and neuronal excitability. This review describes the primary properties of CaN and illustrates its functions and modes of action by focusing on several representative targets, in particular glutamate receptors, striatal enriched protein phosphatase (STEP), and neuromodulin (GAP43), and their functional significance for synaptic plasticity and memory.
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Affiliation(s)
- Karsten Baumgärtel
- Dorris Neuroscience Center, Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037-1000, USA
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Braithwaite SP, Stock JB, Lombroso PJ, Nairn AC. Protein phosphatases and Alzheimer's disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 106:343-79. [PMID: 22340724 PMCID: PMC3739963 DOI: 10.1016/b978-0-12-396456-4.00012-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Alzheimer's Disease (AD) is characterized by progressive loss of cognitive function, linked to marked neuronal loss. Pathological hallmarks of the disease are the accumulation of the amyloid-β (Aβ) peptide in the form of amyloid plaques and the intracellular formation of neurofibrillary tangles (NFTs). Accumulating evidence supports a key role for protein phosphorylation in both the normal and pathological actions of Aβ as well as the formation of NFTs. NFTs contain hyperphosphorylated forms of the microtubule-binding protein tau, and phosphorylation of tau by several different kinases leads to its aggregation. The protein kinases involved in the generation and/or actions of tau or Aβ are viable drug targets to prevent or alleviate AD pathology. However, it has also been recognized that the protein phosphatases that reverse the actions of these protein kinases are equally important. Here, we review recent advances in our understanding of serine/threonine and tyrosine protein phosphatases in the pathology of AD.
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Crouch PJ, Savva MS, Hung LW, Donnelly PS, Mot AI, Parker SJ, Greenough MA, Volitakis I, Adlard PA, Cherny RA, Masters CL, Bush AI, Barnham KJ, White AR. The Alzheimer’s therapeutic PBT2 promotes amyloid-β degradation and GSK3 phosphorylation via a metal chaperone activity. J Neurochem 2011; 119:220-30. [DOI: 10.1111/j.1471-4159.2011.07402.x] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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