scholarly journals Peroxisomal Proliferator-Activated Receptor β/δ Deficiency Induces Cognitive Alterations

2021 ◽  
Author(s):  
Triana Espinosa-Jimenez ◽  
Oriol Busquets ◽  
Amanda Cano ◽  
Ester Verdaguer ◽  
Jordi Olloquequi ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Cognitive Decline ◽  
Dendritic Spine ◽  
Coconut Oil ◽  
Spine Density ◽  
Synaptic Structure ◽  
Synaptic Markers ◽  
The Central Nervous System

Abstract BackgroundPPARβ/δ, the most PPAR abundant isotype in the central nervous system is involved in the modulation of microglial homeostasis and metabolism. Several studies have demonstrated that people suffering from type 2 diabetes mellitus develop cognitive decline turning insulin resistance one of the best predictors of this disturbance. Although numerous investigations have studied the role of PPARb/d in metabolism, its role in neuronal and cognitive function has been underexplored. Therefore, the aim of the study is to determine the role of PPARb/d in the neuropathological pathways involved in the development of cognitive decline and as to whether a risk factor involved in cognitive loss such as obesity modulates neuropathological markers.6-month-old male PPARβ/δ-null (PPARβ/δ-/-) and wildtype (WT) littermates with the same genetic background (C57BL/6X129/SV) and exceptionally, C57BL/6 were used. After the weaning, animals were fed either with conventional chow (CT) or with a palmitic acid-enriched diet containing 45% of fat mainly from hydrogenated coconut oil (HFD). Thus, four groups were defined: WT CT, WT HFD, PPARβ/δ-/- CT and PPARβ/δ-/- HFD and several pathological mechanisms involved in cognitive decline were analyzed.ResultsOur results confirmed that C57BL/6X129/SV showed significantly increased levels of anxiety compared to C57BL/6. Therefore, to evaluate cognitive decline, behavioral tests were dismissed, and dendritic spine quantification and other biochemical biomarkers were performed.PPARβ/δ-/- mice exhibited a decrease in dendritic spine density and synaptic markers, suggesting an alteration in cognitive function and synaptic plasticity. Likewise, our study demonstrated that the lack of PPARβ/δ receptor enhances gliosis in the hippocampus, contributing to astrocyte and microglial activation and also induced an increase in neuroinflammatory biomarkers. Additionally, alterations in the hippocampal insulin receptor pathway were found. Interestingly, while some of the disturbances caused by the lack of PPARβ/δ were not affected by feeding the HFD, others were exacerbated or required the combination of both factors.ConclusionsTaken together, these findings suggest that the loss of PPARβ/δ-/- affects neuronal and synaptic structure, contributing to cognitive dysfunction and, they also present this receptor as a possible new target for the treatment of cognitive decline.

scholarly journals Preservation of dendritic spine morphology and postsynaptic signaling markers after treatment with solid lipid curcumin particles in the 5xFAD mouse model of Alzheimer’s disease

2020 ◽  
Author(s):  
Panchanan Maiti ◽  
Zackary L Bowers ◽  
Ali Bourcier ◽  
Jarod MOrse ◽  
Gary L Dunbar
Keyword(s):  
Alzheimer’S Disease ◽  
Cognitive Function ◽  
Dendritic Spines ◽  
Dendritic Spine ◽  
Amyloid Plaque ◽  
Spine Density ◽  
Solid Lipid ◽  
Dendritic Spine Density ◽  
Synaptic Markers ◽  
5Xfad Mice

Abstract Background Synaptic failure is one of the principal events associated with cognitive dysfunction in Alzheimer’s disease (AD). Preservation of existing synapses and prevention of synaptic loss are promising strategies to preserve cognitive function in AD patients. As a potent natural anti-oxidant, anti-amyloid, anti-inflammatory polyphenol, curcumin (Cur) shows great promise as a therapy for AD. However, hydrophobicity of natural Cur limits its solubility, stability, bioavailability and clinical utility for AD therapy. We have demonstrated that solid lipid curcumin particles (SLCP) have greater therapeutic potential than natural Cur in vitro and in vivo models of AD. In the present study, we have investigated whether SLCP has any preservative role on affected dendritic spines and synaptic markers in 5xFAD mice.Methods Six- and 12-month-old 5xFAD and age-matched wild-type mice received oral administration of SLCP (100 mg/kg body weight) or equivalent amounts of vehicle for 2 months. Neuronal morphology, neurodegeneration and amyloid plaque load were investigated from prefrontal cortex (PFC), entorhinal cortex (EC), CA1, CA3 and the subicular complex (SC). Further, dendritic spine density of apical and basal branches were studied by Golgi-Cox stain. Further, synaptic markers, such as synaptophysin, PSD95, Shank, Homer, Drebrin, kalirin-7, CREB and phosphorylated CREB (pCREB) were studied using Western blots. Finally, cognitive and motor functions were assessed using open field, novel object recognition (NOR) and Morris water maze (MWM) tasks after treatment with SLCP.Results We observed an increase number of pyknotic and degenerated cells in all these brain areas in 5xFAD mice and SLCP treatment partially protected against those losses. Decrease in dendritic arborization and dendritic spine density from primary and secondary apical and basal branches were observed in PFC, EC, CA1, CA3 in both 6- and 12-month-old 5xFAD mice and SLCP treatments partially preserved the normal morphology of these dendritic spines. In addition, pre- and post-synaptic protein markers were also restored by SLCP treatment. Furthermore, SLCP treatment improved NOR and cognitive function in 5xFAD mice.Conclusions Overall, these findings indicate that use of SLCP exerts neuroprotective properties by decreasing amyloid plaque burden, preventing neuronal death, as well as preservation of dendritic spine density and synaptic markers in the 5xFAD mice.

scholarly journals Preservation of dendritic spine morphology and postsynaptic signaling markers after treatment with solid lipid curcumin particles in the 5xFAD mouse model of Alzheimer’s amyloidosis

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Panchanan Maiti ◽  
Zackary Bowers ◽  
Ali Bourcier-Schultz ◽  
Jarod Morse ◽  
Gary L. Dunbar
Keyword(s):  
Cognitive Function ◽  
Dendritic Spines ◽  
Dendritic Spine ◽  
Amyloid Plaque ◽  
Spine Density ◽  
In Vivo Models ◽  
Solid Lipid ◽  
Dendritic Spine Density ◽  
Synaptic Markers ◽  
5Xfad Mice

Abstract Background Synaptic failure is one of the principal events associated with cognitive dysfunction in Alzheimer’s disease (AD). Preservation of existing synapses and prevention of synaptic loss are promising strategies to preserve cognitive function in AD patients. As a potent natural anti-oxidant, anti-amyloid, and anti-inflammatory polyphenol, curcumin (Cur) shows great promise as a therapy for AD. However, hydrophobicity of natural Cur limits its solubility, stability, bioavailability, and clinical utility for AD therapy. We have demonstrated that solid lipid curcumin particles (SLCP) have greater therapeutic potential than natural Cur in vitro and in vivo models of AD. In the present study, we have investigated whether SLCP has any preservative role on affected dendritic spines and synaptic markers in 5xFAD mice. Methods Six- and 12-month-old 5xFAD and age-matched wild-type mice received oral administration of SLCP (100 mg/kg body weight) or equivalent amounts of vehicle for 2 months. Neuronal morphology, neurodegeneration, and amyloid plaque load were investigated from prefrontal cortex (PFC), entorhinal cortex (EC), CA1, CA3, and the subicular complex (SC). In addition, the dendritic spine density from apical and basal branches was studied by Golgi-Cox stain. Further, synaptic markers, such as synaptophysin, PSD95, Shank, Homer, Drebrin, Kalirin-7, CREB, and phosphorylated CREB (pCREB) were studied using Western blots. Finally, cognitive and motor functions were assessed using open-field, novel object recognition (NOR) and Morris water maze (MWM) tasks after treatment with SLCP. Results We observed an increased number of pyknotic and degenerated cells in all these brain areas in 5xFAD mice and SLCP treatment partially protected against those losses. Decrease in dendritic arborization and dendritic spine density from primary, secondary, and tertiary apical and basal branches were observed in PFC, EC, CA1, and CA3 in both 6- and 12-month-old 5xFAD mice, and SLCP treatments partially preserved the normal morphology of these dendritic spines. In addition, pre- and postsynaptic protein markers were also restored by SLCP treatment. Furthermore, SLCP treatment improved NOR and cognitive function in 5xFAD mice. Conclusions Overall, these findings indicate that use of SLCP exerts neuroprotective properties by decreasing amyloid plaque burden, preventing neuronal death, and preserving dendritic spine density and synaptic markers in the 5xFAD mice.

scholarly journals NEUROPROTECTIVE ROLE OF ASCORBIC ACID: ANTIOXIDANT AND NON-ANTIOXIDANT FUNCTIONS

2018 ◽  
Vol 11 (10) ◽  
pp. 30 ◽  
Author(s):  
Arun Kumar ◽  
Reena V Saini ◽  
Adesh K Saini
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glutamate Toxicity ◽  
Cellular Functions ◽  
Dietary Antioxidant ◽  
The Central Nervous System

Ascorbic acid (AA) or Vitamin C is an important antioxidant which participates in numerous cellular functions. Although in human plasma its concentration is in micromolars but it reaches millimolar concentrations in most of the human tissues. The high ascorbate cellular concentrations are generated and maintained by a specific sodium-dependent Vitamin C transporter type 2 (SVCT2, member of Slc23 family). Metabolic processes recycle Vitamin C from its oxidized forms (ascorbate) inside the cells. AA concentration is highest in the neurons of the central nervous system (CNS) of mammals, and deletion of its transporter affects mice brain and overall survival. In the CNS, intracellular ascorbate serves several functions including antioxidant protection, peptide amidation, myelin formation, synaptic potentiation, and protection against glutamate toxicity. SVCT2 maintains neuronal ascorbate content in CNS which has relevance for neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s disease. As ascorbate supplements decrease infarct size in ischemia-reperfusion injury and protect neurons from oxidative damage, it is a vital dietary antioxidant. The aim of this review is to assess the role of the SVCT2 in regulating neuronal ascorbate homeostasis in CNS and the extent to which ascorbate affects brain function as an antioxidant.

F165. Using CRISPR/Cas9-Based Epigenetic Editing to Study the Role of Schizophrenia-Related Alterations in DNA Methylation on Dendritic Spine Density

2019 ◽  
Vol 85 (10) ◽  
pp. S277
Author(s):  
Jennifer Kuflewski ◽  
Christopher Hensler ◽  
Shahwar Tariq ◽  
David Lewis ◽  
Robert Sweet ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Dendritic Spine ◽  
Spine Density ◽  
Dendritic Spine Density ◽  
Epigenetic Editing

scholarly journals TheGαoActivator Mastoparan-7 Promotes Dendritic Spine Formation in Hippocampal Neurons

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Valerie T. Ramírez ◽  
Eva Ramos-Fernández ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Protein Kinase ◽  
Dendritic Spine ◽  
Hippocampal Neurons ◽  
Biological Effects ◽  
Critical Role ◽  
Head Width ◽  
Dependent Manner ◽  
Spine Density ◽  
Dendritic Spine Density

Mastoparan-7 (Mas-7), an analogue of the peptide mastoparan, which is derived from wasp venom, is a direct activator ofPertussis toxin-(PTX-) sensitive G proteins. Mas-7 produces several biological effects in different cell types; however, little is known about how Mas-7 influences mature hippocampal neurons. We examined the specific role of Mas-7 in the development of dendritic spines, the sites of excitatory synaptic contact that are crucial for synaptic plasticity. We report here that exposure of hippocampal neurons to a low dose of Mas-7 increases dendritic spine density and spine head width in a time-dependent manner. Additionally, Mas-7 enhances postsynaptic density protein-95 (PSD-95) clustering in neurites and activatesGαosignaling, increasing the intracellular Ca2+concentration. To define the role of signaling intermediates, we measured the levels of phosphorylated protein kinase C (PKC), c-Jun N-terminal kinase (JNK), and calcium-calmodulin dependent protein kinase IIα(CaMKIIα) after Mas-7 treatment and determined that CaMKII activation is necessary for the Mas-7-dependent increase in dendritic spine density. Our results demonstrate a critical role forGαosubunit signaling in the regulation of synapse formation.

scholarly journals Hippocampal CA1 Pyramidal Neurons ofMecp2Mutant Mice Show a Dendritic Spine Phenotype Only in the Presymptomatic Stage

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Christopher A. Chapleau ◽  
Elena Maria Boggio ◽  
Gaston Calfa ◽  
Alan K. Percy ◽  
Maurizio Giustetto ◽  
...  
Keyword(s):  
Dendritic Spines ◽  
Dendritic Spine ◽  
Pyramidal Neurons ◽  
Mutant Mice ◽  
Spine Density ◽  
Ca1 Pyramidal Neurons ◽  
Dendritic Spine Density ◽  
Presymptomatic Stage ◽  
Deficient Mice

Alterations in dendritic spines have been documented in numerous neurodevelopmental disorders, including Rett Syndrome (RTT). RTT, an X chromosome-linked disorder associated with mutations inMECP2, is the leading cause of intellectual disabilities in women. Neurons inMecp2-deficient mice show lower dendritic spine density in several brain regions. To better understand the role of MeCP2 on excitatory spine synapses, we analyzed dendritic spines of CA1 pyramidal neurons in the hippocampus ofMecp2tm1.1Jaemale mutant mice by either confocal microscopy or electron microscopy (EM). At postnatal-day 7 (P7), well before the onset of RTT-like symptoms, CA1 pyramidal neurons from mutant mice showed lower dendritic spine density than those from wildtype littermates. On the other hand, at P15 or later showing characteristic RTT-like symptoms, dendritic spine density did not differ between mutant and wildtype neurons. Consistently, stereological analyses at the EM level revealed similar densities of asymmetric spine synapses in CA1stratum radiatumof symptomatic mutant and wildtype littermates. These results raise caution regarding the use of dendritic spine density in hippocampal neurons as a phenotypic endpoint for the evaluation of therapeutic interventions in symptomaticMecp2-deficient mice. However, they underscore the potential role of MeCP2 in the maintenance of excitatory spine synapses.

scholarly journals Necrostatin-1 Mitigates Cognitive Dysfunction in Prediabetic Rats With no Alteration in Insulin Sensitivity

2020 ◽  
Author(s):  
Ada Admin ◽  
Kewarin Jinawong ◽  
Nattayaporn Apaijai ◽  
Supawit Wongsuchai ◽  
Wasana Pratchayasakul ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Cognitive Function ◽  
Insulin Sensitivity ◽  
Cognitive Decline ◽  
High Fat Diet ◽  
Spine Density ◽  
High Fat ◽  
Dendritic Spine Density ◽  
Microglial Morphology ◽  
Brain Mitochondrial Function

Previous studies show that 12-week of high-fat diet (HFD) consumption caused not only prediabetes, but also cognitive decline and brain pathologies. Recently, necrostatin-1 (nec-1), a necroptosis inhibitor, showed beneficial effects in brain against stroke. However, the comparative effects of nec-1 and metformin on cognition and brain pathologies in prediabetes have not been investigated. We hypothesized that nec-1 and metformin equally attenuated cognitive decline and brain pathologies in prediabetic rats. Rats (n=32) were fed with either normal diet (ND) or high-fat diet (HFD) for 20 weeks. At week 13, ND-fed rats were given a vehicle (n=8) and HFD-fed rats were randomly assigned into 3 subgroups (n=8/subgroup) with vehicle, nec-1 or metformin for 8 weeks. Metabolic parameters, cognitive function, brain insulin receptor function, synaptic plasticity, dendritic spine density, microglial morphology, brain mitochondrial function, Alzheimer’s protein, and cell death were determined.<b> </b>HFD-fed rats exhibited prediabetes, cognitive decline, and brain pathologies. Nec-1 and metformin equally improved cognitive function, synaptic plasticity, dendritic spine density, microglial morphology, brain mitochondrial function, reduced hyperphosphorylated-tau and necroptosis in HFD-fed rats. Interestingly metformin, but not nec-1, improved brain insulin sensitivity in those rats.<b> </b><b> </b>In conclusion, necroptosis inhibition directly improved cognition in prediabetic rats without alteration in insulin sensitivity.

scholarly journals The association between injurious falls and older adults’ cognitive function: the role of depressive mood and physical performance

2021 ◽  
Author(s):  
Caterina Trevisan ◽  
Enrico Ripamonti ◽  
Giulia Grande ◽  
Federico Triolo ◽  
Stina Ek ◽  
...  
Keyword(s):  
Older Adults ◽  
Cognitive Function ◽  
Cognitive Decline ◽  
Physical Performance ◽  
Walking Speed ◽  
Depressive Mood ◽  
Time Interval ◽  
Injurious Falls

Abstract Background The impact of falls on cognitive function is unclear. We explored whether injurious falls are associated with cognitive decline in older adults, and evaluated the role of changes in psychological and physical health as mediators of such association. Methods This prospective study involved 2,267 community-dwelling participants in the Swedish National study on Aging and Care in Kungsholmen (≥60 years). Data on injurious falls (i.e., falls requiring medical attention) during each 3-year time interval of follow-up were obtained from national registers. Assessment of cognitive function (Mini-Mental State Examination[MMSE]), depressive mood (Montgomery-Åsberg Depression Rating Scale), and physical performance (walking speed) were carried out every 3 or 6 years over a 12-year follow-up. The association between falls and cognition was estimated through linear mixed effects models, and the mediating role of changes in depressive mood and physical performance was tested using mediation analysis. Results After adjusting for potential confounders, individuals who experienced injurious falls had a greater annual decline in MMSE in the subsequent time interval (β=-1.49, 95%CI:-1.84;-1.13), than those who did not. The association increased with the occurrence of ≥2 falls (β=-2.13, 95%CI:-2.70;-1.56). Worsening of walking speed and depressive mood explained around 26% and 8%, respectively, of the association between falls and cognitive decline. Conclusions Injurious falls are associated with greater cognitive decline, and this association is partly mediated by worsening of physical performance and, in a lesser extent, of depressive mood. These findings suggest that physical deficits and low mood are potential therapeutic targets for mitigating the association between falls and cognitive decline.

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