scholarly journals Effects of Caloric Intake on Learning and Memory Function in Juvenile C57BL/6J Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Bao-Lei Xu ◽  
Rong Wang ◽  
Li-Na Ma ◽  
Wen Dong ◽  
Zhi-Wei Zhao ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Memory Function ◽  
Caloric Intake ◽  
Camp Response Element Binding ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Downstream Effectors ◽  
Element Binding Protein

Dietary composition may influence neuronal function as well as processes underlying synaptic plasticity. In this study, we aimed to determine the effect of high and low caloric diets on a mouse model of learning and memory and to explore mechanisms underlying this process. Mice were divided into three different dietary groups: normal control(n=12), high-caloric (HC) diet(n=12), and low-caloric (LC) diet(n=12). After 6 months, mice were evaluated on the Morris water maze to assess spatial memory ability. We found that HC diet impaired learning and memory function relative to both control and LC diet. The levels of SIRT1 as well as its downstream effectors p53, p16, and peroxisome proliferator-activated receptorγ(PPARγ) were decreased in brain tissues obtained from HC mice. LC upregulated SIRT1 but downregulated p53, p16, and PPARγ. The expressions of PI3K and Akt were not altered after HC or LC diet treatment, but both LC and HC elevated the levels of phosphorylated-cAMP response element-binding protein (p-CREB) and IGF-1 in hippocampal CA1 region. Therefore, HC diet-induced dysfunction in learning and memory may be prevented by caloric restriction via regulation of the SIRT1-p53 or IGF-1 signaling pathways and phosphorylation of CREB.

scholarly journals BH4 activates CaMKK2 and rescues the cardiomyopathic phenotype in rodent models of diabetes

2020 ◽  
Vol 3 (9) ◽  
pp. e201900619
Author(s):  
Hyoung Kyu Kim ◽  
Tae Hee Ko ◽  
In-Sung Song ◽  
Yu Jeong Jeong ◽  
Hye Jin Heo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Therapeutic Potential ◽  
Cardiac Contractility ◽  
Camp Response Element Binding ◽  
Mitochondrial Activity ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Calcium Calmodulin Dependent ◽  
Element Binding Protein ◽  
Underlying Mechanisms

Diabetic cardiomyopathy (DCM) is a major cause of mortality/morbidity in diabetes mellitus patients. Although tetrahydrobiopterin (BH4) shows therapeutic potential as an endogenous cardiovascular target, its effect on myocardial cells and mitochondria in DCM and the underlying mechanisms remain unknown. Here, we determined the involvement of BH4 deficiency in DCM and the therapeutic potential of BH4 supplementation in a rodent DCM model. We observed a decreased BH4:total biopterin ratio in heart and mitochondria accompanied by cardiac remodeling, lower cardiac contractility, and mitochondrial dysfunction. Prolonged BH4 supplementation improved cardiac function, corrected morphological abnormalities in cardiac muscle, and increased mitochondrial activity. Proteomics analysis revealed oxidative phosphorylation (OXPHOS) as the BH4-targeted biological pathway in diabetic hearts as well as BH4-mediated rescue of down-regulated peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α) signaling as a key modulator of OXPHOS and mitochondrial biogenesis. Mechanistically, BH4 bound to calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) and activated downstream AMP-activated protein kinase/cAMP response element binding protein/PGC-1α signaling to rescue mitochondrial and cardiac dysfunction in DCM. These results suggest BH4 as a novel endogenous activator of CaMKK2.

scholarly journals PGC-1α Signaling Increases GABA(A) Receptor Subunit α2 Expression, GABAergic Neurotransmission and Anxiety-Like Behavior in Mice

2021 ◽  
Vol 14 ◽  
Author(s):  
Taavi Vanaveski ◽  
Svetlana Molchanova ◽  
Dan Duc Pham ◽  
Annika Schäfer ◽  
Ceren Pajanoja ◽  
...  
Keyword(s):  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Gabaergic Neurotransmission ◽  
Gaba A ◽  
Protein Levels ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Hippocampal Ca1 ◽  
Pparγ Agonist

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a master regulator of mitochondria biogenesis and cell stress playing a role in metabolic and degenerative diseases. In the brain PGC-1α expression has been localized mainly to GABAergic interneurons but its overall role is not fully understood. We observed here that the protein levels of γ-aminobutyric acid (GABA) type A receptor-α2 subunit (GABARα2) were increased in hippocampus and brain cortex in transgenic (Tg) mice overexpressing PGC-1α in neurons. Along with this, GABARα2 expression was enhanced in the hippocampus of the PGC-1α Tg mice, as shown by quantitative PCR. Double immunostaining revealed that GABARα2 co-localized with the synaptic protein gephyrin in higher amounts in the striatum radiatum layer of the hippocampal CA1 region in the Tg compared with Wt mice. Electrophysiology revealed that the frequency of spontaneous and miniature inhibitory postsynaptic currents (mIPSCs) was increased in the CA1 region in the Tg mice, indicative of an augmented GABAergic transmission. Behavioral tests revealed an increase for anxiety-like behavior in the PGC-1α Tg mice compared with controls. To study whether drugs acting on PPARγ can affect GABARα2, we employed pioglitazone that elevated GABARα2 expression in primary cultured neurons. Similar results were obtained using the specific PPARγ agonist, N-(2-benzoylphenyl)-O-[2-(methyl-2-pyridinylamino) ethyl]-L-tyrosine hydrate (GW1929). These results demonstrate that PGC-1α regulates GABARα2 subunits and GABAergic neurotransmission in the hippocampus with behavioral consequences. This indicates further that drugs like pioglitazone, widely used in the treatment of type 2 diabetes, can influence GABARα2 expression via the PPARγ/PGC-1α system.

scholarly journals Aspirin binds to PPARα to stimulate hippocampal plasticity and protect memory

2018 ◽  
Vol 115 (31) ◽  
pp. E7408-E7417 ◽  
Author(s):  
Dhruv Patel ◽  
Avik Roy ◽  
Madhuchhanda Kundu ◽  
Malabendu Jana ◽  
Chi-Hao Luan ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Calcium Influx ◽  
Hippocampal Slices ◽  
Direct Interaction ◽  
Camp Response Element Binding ◽  
Nuclear Hormone Receptor ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Hippocampal Plasticity ◽  
Element Binding Protein

Despite its long history, until now, no receptor has been identified for aspirin, one of the most widely used medicines worldwide. Here we report that peroxisome proliferator-activated receptor alpha (PPARα), a nuclear hormone receptor involved in fatty acid metabolism, serves as a receptor of aspirin. Detailed proteomic analyses including cheminformatics, thermal shift assays, and TR-FRET revealed that aspirin, but not other structural homologs, acts as a PPARα ligand through direct binding at the Tyr314 residue of the PPARα ligand-binding domain. On binding to PPARα, aspirin stimulated hippocampal plasticity via transcriptional activation of cAMP response element-binding protein (CREB). Finally, hippocampus-dependent behavioral analyses, calcium influx assays in hippocampal slices and quantification of dendritic spines demonstrated that low-dose aspirin treatment improved hippocampal plasticity and memory in FAD5X mice, but not in FAD5X/Ppara-null mice. These findings highlight a property of aspirin: stimulating hippocampal plasticity via direct interaction with PPARα.

scholarly journals Shifting the feeding of mice to the rest phase creates metabolic alterations, which, on their own, shift the peripheral circadian clocks by 12 hours

2015 ◽  
Vol 112 (48) ◽  
pp. E6683-E6690 ◽  
Author(s):  
Atish Mukherji ◽  
Ahmad Kobiita ◽  
Pierre Chambon
Keyword(s):  
Molecular Mechanisms ◽  
Glycogen Synthase ◽  
Active Phase ◽  
Camp Response Element Binding ◽  
Circadian Clocks ◽  
Metabolic Reprogramming ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Metabolic Alterations ◽  
Element Binding Protein

The molecular mechanisms underlying the events through which alterations in diurnal activities impinge on peripheral circadian clocks (PCCs), and reciprocally how the PCCs affect metabolism, thereby generating pathologies, are still poorly understood. Here, we deciphered how switching the diurnal feeding from the active to the rest phase, i.e., restricted feeding (RF), immediately creates a hypoinsulinemia during the active phase, which initiates a metabolic reprogramming by increasing FFA and glucagon levels. In turn, peroxisome proliferator-activated receptor alpha (PPARα) activation by free fatty acid (FFA), and cAMP response element-binding protein (CREB) activation by glucagon, lead to further metabolic alterations during the circadian active phase, as well as to aberrant activation of expression of the PCC components nuclear receptor subfamily 1, group D, member 1 (Nr1d1/RevErbα), Period (Per1 and Per2). Moreover, hypoinsulinemia leads to an increase in glycogen synthase kinase 3β (GSK3β) activity that, through phosphorylation, stabilizes and increases the level of the RevErbα protein during the active phase. This increase then leads to an untimely repression of expression of the genes containing a RORE DNA binding sequence (DBS), including the Bmal1 gene, thereby initiating in RF mice a 12-h PCC shift to which the CREB-mediated activation of Per1, Per2 by glucagon modestly contributes. We also show that the reported corticosterone extraproduction during the RF active phase reflects an adrenal aberrant activation of CREB signaling, which selectively delays the activation of the PPARα–RevErbα axis in muscle and heart and accounts for the retarded shift of their PCCs.

scholarly journals Inhibition of Glyceroneogenesis by Histone Deacetylase 3 Contributes to Lipodystrophy in Mice with Adipose Tissue Inflammation

Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 1829-1838 ◽  
Author(s):  
Jin Zhang ◽  
Tara M. Henagan ◽  
Zhanguo Gao ◽  
Jianping Ye
Keyword(s):  
Adipose Tissue ◽  
Histone Deacetylase ◽  
Gene Promoter ◽  
Camp Response Element Binding ◽  
Peroxisome Proliferator ◽  
Camp Response Element ◽  
Response Element ◽  
Peroxisome Proliferator Activated Receptor ◽  
Histone Deacetylase 3 ◽  
Element Binding Protein

We have reported that the nuclear factor-κB (NF-κB) induces chronic inflammation in the adipose tissue of p65 transgenic (Tg) mice, in which the NF-κB subunit p65 (RelA) is overexpressed from the adipocyte protein 2 (aP2) gene promoter. Tg mice suffer a mild lipodystrophy and exhibit deficiency in adipocyte differentiation. To understand molecular mechanism of the defect in adipocytes, we investigated glyceroneogenesis by examining the activity of cytosolic phosphoenolpyruvate carboxykinase (PEPCK) in adipocytes. In aP2-p65 Tg mice, Pepck expression is inhibited at both the mRNA and protein levels in adipose tissue. The mRNA reduction is a consequence of transcriptional inhibition but not alteration in mRNA stability. The Pepck gene promoter is inhibited by NF-κB, which enhances the corepressor activity through activation of histone deacetylase 3 (HDAC3) in the nucleus. HDAC3 suppresses Pepck transcription by inhibiting the transcriptional activators, peroxisome proliferator-activated receptor-γ, and cAMP response element binding protein. The NF-κB activity is abolished by Hdac3 knockdown or inhibition of HDAC3 catalytic activity. In a chromatin immunoprecipitation assay, HDAC3 interacts with peroxisome proliferator-activated receptor-γ and cAMP response element binding protein in the Pepck promoter when NF-κB is activated by TNF-α. These results suggest that HDAC3 mediates NF-κB activity to repress Pepck transcription. This mechanism is responsible for inhibition of glyceroneogenesis in adipocytes, which contributes to lipodystrophy in the aP2-p65 Tg mice.

CREBL2, interacting with CREB, induces adipogenesis in 3T3-L1 adipocytes

2011 ◽  
Vol 439 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Xi Ma ◽  
Heyu Zhang ◽  
Lan Yuan ◽  
Hao Jing ◽  
Phil Thacker ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Binding Protein ◽  
Critical Role ◽  
Camp Response Element Binding ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Glucose Transporter 1 ◽  
Creb Phosphorylation ◽  
Protein Levels ◽  
Element Binding Protein

The factors that influence preadipocyte determination remain poorly understood. In the present paper, we report that CREBL2 [CREB (cAMP-response-element-binding protein)-like 2], a novel bZIP_1 protein, is up-regulated during MDI-induced preadipocyte differentiation. During both overexpression and under physiological conditions, CREBL2 interacted and was entirely co-localized with CREB. Overexpression of CREBL2 was sufficient to promote adipogenesis via up-regulating the expression of PPARγ (peroxisome-proliferator-activated receptor γ) and C/EBPα (CCAAT/enhancer-binding protein α) and accelerate lipogenesis accompanied with increased GLUT (glucose transporter) 1 and GLUT4. CREBL2 knockdown restrained adipogenic conversion and lipogenesis. Additionally, depletion of CREB could completely block the effects of overexpressed CREBL2, whereas an increase in CREB could not drive adipogenesis in the absence of CREBL2, indicating that the roles for CREBL2 on adipogenesis were CREB-dependent. Furthermore, siCREBL2 [siRNA (short interfering RNA) against CREBL2] could down-regulate CREB transcriptional activity and suppress CREB phosphorylation. CREB knockdown decreased the CREBL2 protein levels and vice versa. Collectively, the results of the present study indicate that CREBL2 plays a critical role in adipogenesis and lipogenesis via interaction with CREB.

scholarly journals High levels of 27-hydroxycholesterol results in synaptic plasticity alterations in the hippocampus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raul Loera-Valencia ◽  
Erika Vazquez-Juarez ◽  
Alberto Muñoz ◽  
Gorka Gerenu ◽  
Marta Gómez-Galán ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Memory Function ◽  
Long Term Potentiation ◽  
Synaptic Function ◽  
Cholesterol Homeostasis ◽  
Stratum Radiatum ◽  
Actin Binding ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Term Potentiation

AbstractAlterations in brain cholesterol homeostasis in midlife are correlated with a higher risk of developing Alzheimer’s disease (AD). However, global cholesterol-lowering therapies have yielded mixed results when it comes to slowing down or preventing cognitive decline in AD. We used the transgenic mouse model Cyp27Tg, with systemically high levels of 27-hydroxycholesterol (27-OH) to examine long-term potentiation (LTP) in the hippocampal CA1 region, combined with dendritic spine reconstruction of CA1 pyramidal neurons to detect morphological and functional synaptic alterations induced by 27-OH high levels. Our results show that elevated 27-OH levels lead to enhanced LTP in the Schaffer collateral-CA1 synapses. This increase is correlated with abnormally large dendritic spines in the stratum radiatum. Using immunohistochemistry for synaptopodin (actin-binding protein involved in the recruitment of the spine apparatus), we found a significantly higher density of synaptopodin-positive puncta in CA1 in Cyp27Tg mice. We hypothesize that high 27-OH levels alter synaptic potentiation and could lead to dysfunction of fine-tuned processing of information in hippocampal circuits resulting in cognitive impairment. We suggest that these alterations could be detrimental for synaptic function and cognition later in life, representing a potential mechanism by which hypercholesterolemia could lead to alterations in memory function in neurodegenerative diseases.

scholarly journals Anti-adipogenic effect of mastoparan B analogue peptide on 3T3-L1 preadipocytes

2018 ◽  
Vol 13 (4) ◽  
pp. 333-339
Author(s):  
Ji Hye Kim ◽  
Mi Jeong Jo ◽  
Hye Jin Go ◽  
Nam Gyu Park ◽  
Gun Do Kim
Keyword(s):  
Glycogen Synthase ◽  
Binding Protein ◽  
Regulatory Element ◽  
Cardiovascular Effects ◽  
Peroxisome Proliferator ◽  
Preadipocyte Differentiation ◽  
Peroxisome Proliferator Activated Receptor ◽  
Element Binding Protein ◽  
Gsk 3Β ◽  
Adipogenic Effect

Mastoparan B (MP-B), a cationic tetradecapeptide isolated from the venom of the Vespa basalis, exhibits cardiovascular effects, local edema and antibacterial activity. In this study, the anti-adipogenic effect of an MP-B analogue and its mechanism of action in 3T3-L1 preadipocytes were studied. The MP-B analogue (MP-B12) inhibited preadipocyte differentiation and decreased the expression of adipogenic transcription factors, including CCAAT/enhancer binding protein-alpha (C/EBPα), nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) and sterol regulatory element-binding protein-1 (SREBP-1). Moreover, MP-B12 regulated the phosphorylation of Akt and glycogen synthase kinase-3 beta (GSK-3β), both of which play a role in preadipocyte differentiation, in which insulin and certain growth factors stimulated adipogenesis. This study demonstrates that MP-B12 inhibits preadipocyte differentiation and the accumulation of lipid droplets in 3T3-L1 preadipocytes and could potentially be used to treat obesity.Video Clip of Methodology:4 min 11 sec   Full Screen   Alternate  

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