scholarly journals Antibody Protection against Long-Term Memory Loss Induced by Monomeric C-Reactive Protein in a Mouse Model of Dementia

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 828
Author(s):  
Elisa García-Lara ◽  
Samuel Aguirre ◽  
Núria Clotet ◽  
Xenia Sawkulycz ◽  
Clara Bartra ◽  
...  

Monomeric C-reactive protein (mCRP), the activated isoform of CRP, induces tissue damage in a range of inflammatory pathologies. Its detection in infarcted human brain tissue and its experimentally proven ability to promote dementia with Alzheimer’s disease (AD) traits at 4 weeks after intrahippocampal injection in mice have suggested that it may contribute to the development of AD after cerebrovascular injury. Here, we showed that a single hippocampal administration of mCRP in mice induced memory loss, lasting at least 6 months, along with neurodegenerative changes detected by increased levels of hyperphosphorylated tau protein and a decrease of the neuroplasticity marker Egr1. Furthermore, co-treatment with the monoclonal antibody 8C10 specific for mCRP showed that long-term memory loss and tau pathology were entirely avoided by early blockade of mCRP. Notably, 8C10 mitigated Egr1 decrease in the mouse hippocampus. 8C10 also protected against mCRP-induced inflammatory pathways in a microglial cell line, as shown by the prevention of increased generation of nitric oxide. Additional in vivo and in vitro neuroprotective testing with the anti-inflammatory agent TPPU, an inhibitor of the soluble epoxide hydrolase enzyme, confirmed the predominant involvement of neuroinflammatory processes in the dementia induced by mCRP. Therefore, locally deposited mCRP in the infarcted brain may be a novel biomarker for AD prognosis, and its antibody blockade opens up therapeutic opportunities for reducing post-stroke AD risk.

Author(s):  
О.А. Соловьева ◽  
М.А. Грудень ◽  
И.А. Калинин ◽  
А.М. Ратмиров ◽  
В.В. Шерстнев

Одним из важнейших патогенетических звеньев развития синуклеинопатий - группы хронических нейродегенеративных заболеваний, таких как болезнь Паркинсона, деменции с тельцами Леви и других является гиперпродукция белка α-синуклеина с последующей его агрегацией и образованием различающихся по размеру и структуре амилоидогенных форм белка, которые инициируют гибель нервных или глиальных клеток. В настоящее время для более полного понимания происходящих in vivo патологических процессов актуально изучение на моделях животных поведенческих эффектов как нативного белка α-синуклеина, так и его отдельных амилоидогенных структур (олигомеров и фибрилл), полученных и охарактеризованных in vitro, а также композиционных смесей данных белковых конформаций. Целью данной работы явилось изучение влияния композиционной смеси нативного белка α-синуклеина и олигомеров α-синуклеина при хроническом интраназальном введении на двигательную активность, кратковременную и долговременную память, а также тревожность стареющих мышей. Методы. Опыты проводили на 12- месячных самцах мышей C57Bl/6, которым на протяжении 14 дней один раз в сутки вводили отдельно в каждую ноздрю раствор α-синуклеина и его олигомеров, либо физиологический раствор. В тестах «Открытое поле», «Распознавание нового объекта», «Условная реакция пассивного избегания» и «Приподнятый крестообразный лабиринт» оценивали двигательную активность, кратко- и долговременную память, и тревожность животных. Результаты. Показано, что исследованная композиционная смесь конформаций α-синуклеина не вызывает статистически значимых изменений регистрируемых поведенческих показателей у стареющих мышей. Вместе с тем, ранее нами было документировано, что в условиях аналогичного экспериментального протокола нативный α-синуклеин инициирует снижение двигательной активности, а олигомеры α-синуклеина - угнетение двигательной активности, нарушение долговременной памяти и тревожности животных. Заключение. Полученные результаты свидетельствуют о менее выраженных поведенческих эффектах композиционной смеси нативной и олигомерной форм α-синуклеина, по сравнению с отдельными ее компонентами. Рассматриваются возможные механизмы выявленных особенностей влияния исследованной композиционной смеси конформаций α-синуклеина на поведенческом уровне. One of the most important steps in the pathogenesis of synucleinopathies, a group of chronic neurodegenerative diseases, such as Parkinson’s disease, dementia with Lewy bodies and others, is overproduction of α-synuclein protein, followed by its aggregation and formation of amyloidogenic protein species, which differ in their size and structure and initiate death of nerve or glial cells. At present, better understanding of in vivo pathological processes requires studying behavioral effects of both the native α-synuclein protein and its individual amyloidogenic structures (oligomers and fibrils) obtained and characterized in vitro on animal models, as well as composite mixtures of these protein conformations. The aim of this work was to study effects of chronic nasal application of a composite mixture of native α-synuclein protein and α-synuclein oligomers on motor activity, short-term and long-term memory, and anxiety of aging mice. Methods. Experiments were carried out on 12-month old male C57Bl/6 mice, which received a solution of α-synuclein and its oligomers or a saline solution separately into each nostril for 14 days daily. Motor activity, short- and long-term memory and anxiety of animals were evaluated in Open Field, Novel Object Recognition, Conditioned Passive Avoidance, and Elevated Plus Maze tests. Results. The studied composite mixture of α-synuclein conformations did not induce statistically significant changes in behavioral indices of aging mice. At the same time, we have previously documented that in a similar experimental protocol, native α-synuclein initiates a decrease in motor activity, and α-synuclein oligomers - inhibition of motor activity and disorders of long-term memory and anxiety. Conclusion. The results indicated less pronounced behavioral effects of the composite mixture of native and oligomeric forms of α-synuclein compared with its individual components. The authors discussed possible mechanisms of the behavioral effects of the studied composite mixture of α-synuclein confirmations.


2020 ◽  
Vol 66 (2) ◽  
pp. 130-137
Author(s):  
B.A. Reikhardt ◽  
P.D. Shabanov

Protein kinase CK2 is an important enzyme in the nervous system. The nuclear forms of CK2 regulate chromatin structure and gene expression, the key processes for long-term memory formation. Memory modulators, the Structural Analogues of Etimizole (SAE), were able to increase or decrease the activity of chromatin-associated CK in the cortex and hippocampus of rat brain in vitro. In vivo memory enhancers from SAE-group (3 mg/kg) stimulated CK2 activity and the transcriptional ability of chromatin in the cortex and hippocampus, starting from 30 min with a peak for 60 min and a duration up to 180 min. At these periods the memory inhibitor from the SAE-group reduced CK2 activity and chromatin transcription. It is assumed that the modulating effect of SAE on CK2 activity and transcription underlies the effects of these compounds on long-term memory.


PLoS Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. e3001062
Author(s):  
Diego Barriales ◽  
Itziar Martín-Ruiz ◽  
Ana Carreras-González ◽  
Marta Montesinos-Robledo ◽  
Mikel Azkargorta ◽  
...  

Lyme carditis is an extracutaneous manifestation of Lyme disease characterized by episodes of atrioventricular block of varying degrees and additional, less reported cardiomyopathies. The molecular changes associated with the response to Borrelia burgdorferi over the course of infection are poorly understood. Here, we identify broad transcriptomic and proteomic changes in the heart during infection that reveal a profound down-regulation of mitochondrial components. We also describe the long-term functional modulation of macrophages exposed to live bacteria, characterized by an augmented glycolytic output, increased spirochetal binding and internalization, and reduced inflammatory responses. In vitro, glycolysis inhibition reduces the production of tumor necrosis factor (TNF) by memory macrophages, whereas in vivo, it produces the reversion of the memory phenotype, the recovery of tissue mitochondrial components, and decreased inflammation and spirochetal burdens. These results show that B. burgdorferi induces long-term, memory-like responses in macrophages with tissue-wide consequences that are amenable to be manipulated in vivo.


2008 ◽  
Vol 100 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Donald A. Wilson ◽  
Christiane Linster

Habituation is one of the simplest forms of memory, yet its neurobiological mechanisms remain largely unknown in mammalian systems. This review summarizes recent multidisciplinary analyses of the neurobiology of mammalian odor habituation including in vitro and in vivo synaptic physiology, sensory physiology, behavioral pharmacology, and computational modeling approaches. The findings show that a metabotropic glutamate receptor–mediated depression of afferent synapses to the olfactory cortex is necessary and perhaps sufficient to account for cortical sensory adaptation and short-term behavioral habituation. Furthermore, long-term habituation is an N-methyl-d-aspartate (NMDA) receptor–dependent process within the olfactory bulb. Thus there is both a pharmacological and anatomical distinction between short-term and long-term memory for habituation. The differential locus of change underlying short- and long-term memory leads to predictable differences in their behavioral characteristics, such as specificity.


2008 ◽  
Vol 100 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Laia Jofre-Monseny ◽  
Patricia Huebbe ◽  
Inken Stange ◽  
Christine Boesch-Saadatmandi ◽  
Jan Frank ◽  
...  

The molecular basis of the positive association between apoE4 genotype and CVD remains unclear. There is direct in vitro evidence indicating that apoE4 is a poorer antioxidant relative to the apoE3 isoform, with some indirect in vivo evidence also available. Therefore it was hypothesised that apoE4 carriers may benefit from α-tocopherol (α-Toc) supplementation. Targeted replacement mice expressing the human apoE3 and apoE4 were fed with a diet poor (0 mg/kg diet) or rich (200 mg/kg diet) in α-Toc for 12 weeks. Neither apoE genotype nor dietary α-Toc exerted any effects on the antioxidant defence system, including glutathione, catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase activities. In addition, no differences were observed in mitogen-induced lymphocyte proliferation. α-Toc concentrations were modestly higher in plasma and lower in tissues of apoE4 compared with apoE3 mice, with the greatest differences evident in the lung, suggesting that an apoE4 genotype may reduce α-Toc delivery to tissues. A tendency towards increased plasma F2-isoprostanes in apoE4 mice was observed, while liver thiobarbituric acid-reactive substances did not differ between apoE3 and apoE4 mice. In addition, C-reactive protein (CRP) concentrations were reduced in apoE4 mice indicating that this positive effect on CRP may in part negate the increased CVD risk associated with an apoE4 genotype.


2016 ◽  
Vol 90 (6) ◽  
pp. 3123-3137 ◽  
Author(s):  
Kevin C. Chen ◽  
Richard J. Stanton ◽  
Jareer J. Banat ◽  
Mark R. Wills

ABSTRACTImmune responses of natural killer (NK) cell are controlled by the balance between activating and inhibitory receptors, but the expression of these receptors varies between cells within an individual. Although NK cells are a component of the innate immune system, particular NK cell subsets expressing Ly49H are positively selected and increase in frequency in response to cytomegalovirus infection in mice. Recent evidence suggests that in humans certain NK subsets also have an increased frequency in the blood of human cytomegalovirus (HCMV)-infected individuals. However, whether these subsets differ in their capacity of direct control of HCMV-infected cells remains unclear. In this study, we developed a novelin vitroassay to assess whether human NK cell subsets have differential abilities to inhibit HCMV growth and dissemination. NK cells expressing or lacking NKG2C did not display any differences in controlling viral dissemination. However, whenin vitro-expanded NK cells were used, cells expressing or lacking the inhibitory receptor leukocyte immunoglobulin-like receptor 1 (LIR1) were differentially able to control dissemination. Surprisingly, the ability of LIR1+NK cells to control virus spread differed between HCMV viral strains, and this phenomenon was dependent on amino acid sequences within the viral ligand UL18. Together, the results here outline anin vitrotechnique to compare the long-term immune responses of different human NK cell subsets and suggest, for the first time, that phenotypically defined human NK cell subsets may differentially recognize HCMV infections.IMPORTANCEHCMV infection is ubiquitous in most populations; it is not cleared by the host after primary infection but persists for life. The innate and adaptive immune systems control the spread of virus, for which natural killer (NK) cells play a pivotal role. NK cells can respond to HCMV infection by rapid, short-term, nonspecific innate responses, but evidence from murine studies suggested that NK cells may display long-term, memory-like responses to murine cytomegalovirus infection. In this study, we developed a new assay that examines human NK cell subsets that have been suggested to play a long-term memory-like response to HCMV infection. We show that changes in an HCMV viral protein that interacts with an NK cell receptor can change the ability of NK cell subsets to control HCMV while the acquisition of another receptor has no effect on virus control.


Molecules ◽  
2018 ◽  
Vol 23 (4) ◽  
pp. 737 ◽  
Author(s):  
Jin-Young Sung ◽  
Ji-Hyun Bae ◽  
Jong-Ha Lee ◽  
Yoon-Nyun Kim ◽  
Dae-Kwang Kim

2011 ◽  
Vol 39 (2) ◽  
pp. 53-54
Author(s):  
Kevin Mccarty

2010 ◽  
Vol 56 (8) ◽  
pp. 1345-1348 ◽  
Author(s):  
Simona Valleggi ◽  
Sridevi Devaraj ◽  
Mohan R Dasu ◽  
Ishwarlal Jialal

BACKGROUND C-reactive protein (CRP) inhibits the activity of the endothelial isoform of nitric oxide synthase (eNOS) via uncoupling of the enzyme both in vitro and in vivo. eNOS activity appears to be related in part to its interaction with other cellular proteins, including heat shock protein 90 (Hsp90), caveolin-1, and porin. In this study, we examined the effect of CRP treatment of human aortic endothelial cells (HAECs) on eNOS interaction with caveolin-1, Hsp90, and porin. METHODS We incubated HAECs with CRP (0, 12.5, and 25 mg/L) for 1, 6, or 24 h and assessed the interaction of these proteins with eNOS by immunoprecipitation and western blotting. RESULTS CRP treatment (12.5 and 25 mg/L) of HAECs for 24 h significantly increased eNOS binding to caveolin-1 (40% and 54% increase, respectively; P < 0.05) and decreased binding to Hsp90 (33% and 66% decrease, respectively; P < 0.05). CRP (25 mg/L) also significantly decreased the binding of porin to eNOS (11% decrease, P < 0.05). Similar results were seen when HAECs were treated with CRP for 6 h. CONCLUSIONS These negative protein–protein interactions of eNOS were able to partly explain the CRP-induced decreases in the activity of this critical enzyme, which caused endothelial dysfunction.


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