scholarly journals Arginase Inhibition Supports Survival and Differentiation of Neuronal Precursors in Adult Alzheimer’s Disease Mice

2019 ◽  
Author(s):  
Baruh Polis ◽  
Vyacheslav Gurevich ◽  
Naamah Bloch ◽  
Abraham O. Samson

AbstractAdult neurogenesis is a complex physiological process, which plays a central role in maintaining cognitive functions, and consists of progenitor cell proliferation, newborn cell migration, and cell maturation. Adult neurogenesis is susceptible to alterations under various physiological and pathological conditions. A substantial decay of neurogenesis has been documented in Alzheimer’s disease (AD) patients and animal AD models; however, several treatment strategies can halt any further decline and even induce neurogenesis.Our previous results indicated a potential effect of arginase inhibition, with norvaline, on various aspects of neurogenesis in triple-transgenic mice. To better evaluate this effect, we chronically administer an arginase inhibitor, norvaline, to triple-transgenic and wild-type mice, and apply an advanced immunohistochemistry approach with several biomarkers and bright-field microscopy.Remarkably, we evidence a significant reduction in the density of neuronal progenitors, which demonstrate a different phenotype in the hippocampi of triple-transgenic mice as compared to wild-type animals. However, norvaline shows no significant effect upon the progenitor cell number and constitution. We demonstrate that norvaline treatment leads to an escalation of the polysialylated neuronal cell adhesion molecule immunopositivity, which suggests an improvement in the newborn neuron survival rate. Additionally, we identify a significant increase in the hippocampal microtubule-associated protein 2 stain intensity. We also explore the molecular mechanisms underlying the effects of norvaline on adult mice neurogenesis and provide insights into their machinery.

2020 ◽  
Vol 21 (3) ◽  
pp. 1133 ◽  
Author(s):  
Baruh Polis ◽  
Kolluru D. Srikanth ◽  
Vyacheslav Gurevich ◽  
Naamah Bloch ◽  
Hava Gil-Henn ◽  
...  

Adult neurogenesis is a complex physiological process, which plays a central role in maintaining cognitive functions, and consists of progenitor cell proliferation, newborn cell migration, and cell maturation. Adult neurogenesis is susceptible to alterations under various physiological and pathological conditions. A substantial decay of neurogenesis has been documented in Alzheimer’s disease (AD) patients and animal AD models; however, several treatment strategies can halt any further decline and even induce neurogenesis. Our previous results indicated a potential effect of arginase inhibition, with norvaline, on various aspects of neurogenesis in triple-transgenic mice. To better evaluate this effect, we chronically administered an arginase inhibitor, norvaline, to triple-transgenic and wild-type mice, and applied an advanced immunohistochemistry approach with several biomarkers and bright-field microscopy. Remarkably, we evidenced a significant reduction in the density of neuronal progenitors, which demonstrate a different phenotype in the hippocampi of triple-transgenic mice as compared to wild-type animals. However, norvaline showed no significant effect upon the progenitor cell number and constitution. We demonstrated that norvaline treatment leads to an escalation of the polysialylated neuronal cell adhesion molecule immunopositivity, which suggests an improvement in the newborn neuron survival rate. Additionally, we identified a significant increase in the hippocampal microtubule-associated protein 2 stain intensity. We also explore the molecular mechanisms underlying the effects of norvaline on adult mice neurogenesis and provide insights into their machinery.


2020 ◽  
Vol 26 ◽  
Author(s):  
Nimra Javaid ◽  
Muhammad Ajmal Shah ◽  
Azhar Rasul ◽  
Zunera Chauhdary ◽  
Uzma Saleem ◽  
...  

: Neurodegeneration is a multifactorial process involved the different cytotoxic pathways that lead towards neuronal cell death. Alzheimer’s disease (AD) is a persistent neurodegenerative disorder that normally has a steady onset yet later on it worsens. The documented evidence of AD neuropathology manifested the neuro-inflammation, increased reactive oxygen, nitrogen species and decreased antioxidant protective process; mitochondrial dysfunction as well as increased level of acetylcholinesterase activity. Moreover, enhanced action of proteins leads towards neural apoptosis which have a vital role in the degeneration of neurons. The inability of commercial therapeutic options to treat AD with targeting single mechanism leads the attraction towards organic drugs. Ellagic acid is a dimer of gallic acid, latest studies expressed that ellagic acid can initiate the numerous cell signaling transmission and decrease the progression of disorders, involved in the degeneration of neurons. The influential property of ellagic acid to protect the neurons in neurodegenerative disorders is due to its antioxidant effect, iron chelating and mitochondrial protective effect. The main goal of this review is to critically analyze the molecular mode of action of ellagic acid against neurodegeneration.


2018 ◽  
Vol 2 (2) ◽  
pp. 241-258 ◽  
Author(s):  
Shelli R. Kesler ◽  
Paul Acton ◽  
Vikram Rao ◽  
William J. Ray

Neurodegeneration in Alzheimer’s disease (AD) is associated with amyloid-beta peptide accumulation into insoluble amyloid plaques. The five-familial AD (5XFAD) transgenic mouse model exhibits accelerated amyloid-beta deposition, neuronal dysfunction, and cognitive impairment. We aimed to determine whether connectome properties of these mice parallel those observed in patients with AD. We obtained diffusion tensor imaging and resting-state functional magnetic resonance imaging data for four transgenic and four nontransgenic male mice. We constructed both structural and functional connectomes and measured their topological properties by applying graph theoretical analysis. We compared connectome properties between groups using both binarized and weighted networks. Transgenic mice showed higher characteristic path length in weighted structural connectomes and functional connectomes at minimum density. Normalized clustering and modularity were lower in transgenic mice across the upper densities of the structural connectome. Transgenic mice also showed lower small-worldness index in higher structural connectome densities and in weighted structural networks. Hyper-correlation of structural and functional connectivity was observed in transgenic mice compared with nontransgenic controls. These preliminary findings suggest that 5XFAD mouse connectomes may provide useful models for investigating the molecular mechanisms of AD pathogenesis and testing the effectiveness of potential treatments.


2006 ◽  
Vol 14 (7S_Part_5) ◽  
pp. P301-P302
Author(s):  
Alyson C. Williamson ◽  
Hayley R. LeBlanc ◽  
Brian G. Gentry ◽  
Craige C. Wrenn

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
T. Harach ◽  
N. Marungruang ◽  
N. Duthilleul ◽  
V. Cheatham ◽  
K. D. Mc Coy ◽  
...  

Abstract Alzheimer’s disease is the most common form of dementia in the western world, however there is no cure available for this devastating neurodegenerative disorder. Despite clinical and experimental evidence implicating the intestinal microbiota in a number of brain disorders, its impact on Alzheimer’s disease is not known. To this end we sequenced bacterial 16S rRNA from fecal samples of Aβ precursor protein (APP) transgenic mouse model and found a remarkable shift in the gut microbiota as compared to non-transgenic wild-type mice. Subsequently we generated germ-free APP transgenic mice and found a drastic reduction of cerebral Aβ amyloid pathology when compared to control mice with intestinal microbiota. Importantly, colonization of germ-free APP transgenic mice with microbiota from conventionally-raised APP transgenic mice increased cerebral Aβ pathology, while colonization with microbiota from wild-type mice was less effective in increasing cerebral Aβ levels. Our results indicate a microbial involvement in the development of Abeta amyloid pathology, and suggest that microbiota may contribute to the development of neurodegenerative diseases.


2013 ◽  
Vol 9 ◽  
pp. P190-P190 ◽  
Author(s):  
Juliet Moncaster ◽  
Mark Wojnarowicz ◽  
Srikant Sarangi ◽  
Andrew Fisher ◽  
Olga Minaeva ◽  
...  

2019 ◽  
Author(s):  
Sruti Rayaprolu ◽  
Tianwen Gao ◽  
Hailian Xiao ◽  
Supriya Ramesha ◽  
Laura D. Weinstock ◽  
...  

AbstractBackgroundProteomic characterization of microglia provides the most proximate assessment of functionally relevant molecular mechanisms of neuroinflammation. However, microglial proteomics studies have been limited by low cellular yield and contamination by non-microglial proteins using existing enrichment strategies.MethodsWe coupled magnetic-activated cell sorting (MACS) and fluorescence activated cell sorting (FACS) of microglia with tandem mass tag-mass spectrometry (TMT-MS) to obtain a highly-pure microglial proteome and identified a core set of highly-abundant microglial proteins in adult mouse brain. We interrogated existing human proteomic data for Alzheimer’s disease (AD) relevance of highly-abundant microglial proteins and performed immuno-histochemical and in-vitro validation studies.ResultsQuantitative multiplexed proteomics by TMT-MS of CD11b+ MACS-enriched (N = 5 mice) and FACS-isolated (N = 5 mice), from adult wild-type mice, identified 1,791 proteins. A total of 203 proteins were highly abundant in both datasets, representing a core-set of highly abundant microglial proteins. In addition, we found 953 differentially enriched proteins comparing MACS and FACS-based approaches, indicating significant differences between both strategies. The FACS-isolated microglia proteome was enriched with cytosolic, endoplasmic reticulum, and ribosomal proteins involved in protein metabolism and immune system functions, as well as an abundance of canonical microglial proteins. Conversely, the MACS-enriched microglia proteome was enriched with mitochondrial and synaptic proteins and higher abundance of neuronal, oligodendrocytic and astrocytic proteins. From the 203 consensus microglial proteins with high abundance in both datasets, we confirmed microglial expression of moesin (Msn) in wild-type and 5xFAD mouse brains as well as in human AD brains. Msn expression is nearly exclusively found in microglia that surround Aβ plaques in 5xFAD brains. In in-vitro primary microglial studies, Msn silencing by siRNA decreased Aβ phagocytosis and increased lipopolysaccharide-induced production of the pro-inflammatory cytokine, tumor necrosis factor (TNF). In network analysis of human brain proteomic data, Msn was a hub protein of an inflammatory co-expression module positively associated with AD neuropathological features and cognitive dysfunction.ConclusionsUsing FACS coupled with TMT-MS as the method of choice for microglial proteomics, we define a core set of highly-abundant adult microglial proteins. Among these, we validate Msn as highly-abundant in plaque-associated microglia with relevance to human AD.


2015 ◽  
Vol 96 (1) ◽  
pp. 50-55 ◽  
Author(s):  
A V Leushina ◽  
L F Nurullin ◽  
E O Petukhova ◽  
A L Zefirov ◽  
M A Mukhamedyarov

Aim. Study is aimed to investigate contractility impairments and receptor mechanisms of adrenergic regulation of myocardium inotropic function in Alzheimer’s disease model on transgenic mice.Methods. Experiments were performed on isolated preparations of atria and ventricles myocardium of mice. Transgenic mice of B6C3-Tg(APP695)85Dbo Tg(PSENI)85Dbo genotype were used as animal model of Alzheimer’s disease. Contractile responses of myocardium were registered by conventional myographic technique in isometric conditions. To evaluate the expression of adrenergic receptors, immunofluorescence staining of myocardium with specific antibodies was performed.Results. Transgenic mice showed not only a decreased effect of norepinephrine on myocardium inotropic function but also the inversion of the effect of norepinephrine - the use of 10-5-10-4 M of norepinephrine decreased myocardium inotropic function. Immunofluorescent staining showed decrease of expression of β1- and especially β2-adrenergic receptors ventricular myocardium of transgenic mice comparing to wild type mice. Adrenergic deregulation was registered in ventricles, but not in atria. The features of adrenergic regulatory mechanisms of myocardial contractility in transgenic APP/PS1 mice aged 8-10 months are specific, although somewhat similar to wild type mice aged 8-10 months, and are evidently due to Alzheimer’s disease. The inversion of norepinephrine inotropic effect (from positive to negative) may be explained by switching the intracellular cascade pathway of β2-adrenergic receptors effects to another type of G-protein.Conclusion. The results indicate that peripheral adrenergic mechanisms of myocardial contractility regulation are impaired in studied transgenic mice model of Alzheimer’s disease. Obtained data widen our understanding of Alzheimer’s disease pathogenesis, as well as our conception of relations between cardiovascular diseases and neurodegeneration.


2020 ◽  
Vol 11 (12) ◽  
Author(s):  
Zhourui Wu ◽  
Xia Liu ◽  
Liming Cheng ◽  
Keqiang Ye

AbstractAlzheimer’s disease (AD) is the most common neurodegenerative disease with multifactorial pathologies including Aβ containing senile plaques and neurofibrillary tangles (NFT) consisted of aggregated Tau. Most of the AD patients are sporadic and the familial mutation hereditary patients are composed only 1% of all cases. However, the current AD mouse models employ mutated APP, PS1, or even Tau mutant, in order to display a portion of AD pathologies. Delta-secretase (legumain, or asparaginyl endopeptidase, AEP) simultaneously cleaves both APP and Tau and augments Aβ production and Tau hyperphosphorylation and aggregation, contributing to AD pathogenesis. Here we show that δ-secretase is sufficient to promote prominent AD pathologies in wild-type hAPP/hMAPT double transgenic mice. We crossed hAPP l5 mice and hMAPT mice to generate double transgenic mouse model carrying both human wild-type APP and Tau. Compared to the single transgenic parents, these double transgenic mice demonstrated AD-related pathologies in one-year-old hAPP/hMAPT mice. Notably, overexpression of δ-secretase in hAPP/hMAPT double-transgenic mice evidently accelerated enormous senile plaques and NFT, associated with prominent synaptic defects and cognitive deficits. Hence, δ-secretase facilitates AD pathogenesis independent of any patient-derived mutation.


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