scholarly journals Hydrophilic Glycoproteins of an Edible Green Alga Capsosiphon fulvescens Prevent Aging-Induced Spatial Memory Impairment by Suppressing GSK-3β-Mediated ER Stress in Dorsal Hippocampus

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 168 ◽  
Author(s):  
Jeong Oh ◽  
Taek-Jeong Nam
Keyword(s):  
Oral Administration ◽  
Spatial Memory ◽  
Er Stress ◽  
Cognitive Dysfunction ◽  
Memory Impairment ◽  
Glycogen Synthase ◽  
Dorsal Hippocampus ◽  
Extracellular Signal ◽  
Capsosiphon Fulvescens ◽  
Gsk 3Β

Endoplasmic reticulum (ER) stress is involved in various neurodegenerative disorders. We previously found that Capsosiphon fulvescens (C. fulvescens) crude proteins enhance spatial memory by increasing the expression of brain-derived neurotrophic factor (BDNF) in rat dorsal hippocampus. The present study investigated whether the chronic oral administration of hydrophilic C. fulvescens glycoproteins (Cf-hGP) reduces aging-induced cognitive dysfunction by regulating ER stress in the dorsal hippocampus. The oral administration of Cf-hGP (15 mg/kg/day) for four weeks attenuated the aging-induced increase in ER stress response protein glucose-regulated protein 78 (GRP78) in the synaptosome of the dorsal hippocampus; this was attenuated by the function-blocking anti-BDNF antibody (1 μg/μL) and a matrix metallopeptidase 9 inhibitor 1 (5 μM). Aging-induced GRP78 expression was associated with glycogen synthase kinase-3 beta (GSK-3β) (Tyr216)-mediated c-Jun N-terminal kinase phosphorylation, which was downregulated upon Cf-hGP administration. The Cf-hGP-induced increase in GSK-3β (Ser9) phosphorylation was downregulated by inhibiting tyrosine receptor kinase B and extracellular signal-regulated kinase (ERK)1/2 with cyclotraxin-B (200 nM) and SL327 (10 μM), respectively. Cf-hGP administration or the inhibition of ER stress with salubrinal (1 mg/kg, i.p.) significantly decreased aging-induced spatial memory impairment. These findings suggest that the activation of the synaptosomal BDNF-ERK1/2 signaling in the dorsal hippocampus by Cf-hGP attenuates age-dependent ER stress-induced cognitive dysfunction.

scholarly journals Glycogen Synthase Kinase 3β and Extracellular Signal-Regulated Kinase Inactivate Heat Shock Transcription Factor 1 by Facilitating the Disappearance of Transcriptionally Active Granules after Heat Shock

1998 ◽  
Vol 18 (11) ◽  
pp. 6624-6633 ◽  
Author(s):  
Bin He ◽  
Yong-Hong Meng ◽  
Nahid F. Mivechi
Keyword(s):  
Transcription Factor ◽  
Heat Shock ◽  
Transcriptional Activity ◽  
Glycogen Synthase ◽  
Heat Shock Transcription Factor ◽  
Glycogen Synthase Kinase 3Β ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Gsk 3Β ◽  
Transcription Factor 1

ABSTRACT Heat shock transcription factor 1 (HSF-1) activates the transcription of heat shock genes in eukaryotes. Under normal physiological growth conditions, HSF-1 is a monomer. Its transcriptional activity is repressed by constitutive phosphorylation. Upon activation, HSF-1 forms trimers, acquires DNA binding activity, increases transcriptional activity, and appears as punctate granules in the nucleus. In this study, using bromouridine incorporation and confocal laser microscopy, we demonstrated that newly synthesized pre-mRNAs colocalize to the HSF-1 punctate granules after heat shock, suggesting that these granules are sites of transcription. We further present evidence that glycogen synthase kinase 3β (GSK-3β) and extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) participate in the down regulation of HSF-1 transcriptional activity. Transient increases in the expression of GSK-3β facilitate the disappearance of HSF-1 punctate granules and reduce hsp-70 transcription after heat shock. We have also shown that ERK is the priming kinase for GSK-3β. Taken together, these results indicate that GSK-3β and ERK MAPK facilitate the inactivation of activated HSF-1 after heat shock by dispersing HSF-1 from the sites of transcription.

scholarly journals Glycogen Synthase Kinase 3β Promotes Postoperative Cognitive Dysfunction by Inducing the M1 Polarization and Migration of Microglia

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jingjin Li ◽  
Chonglong Shi ◽  
Zhengnian Ding ◽  
Wenjie Jin
Keyword(s):  
Cognitive Dysfunction ◽  
Lithium Chloride ◽  
Glycogen Synthase ◽  
Postoperative Cognitive Dysfunction ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3Β ◽  
Central Nervous System Complication ◽  
Proinflammatory Mediators ◽  
M1 Polarization ◽  
Gsk 3Β

Postoperative cognitive dysfunction (POCD) is a common postoperative central nervous system complication, especially in the elderly. It has been consistently reported that the pathological process of this clinical syndrome is related to neuroinflammation and microglial proliferation. Glycogen synthase kinase 3β (GSK-3β) is a widely expressed kinase with distinct functions in different types of cells. The role of GSK-3β in regulating innate immune activation has been well documented, but as far as we know, its role in POCD has not been fully elucidated. Lithium chloride (LiCl) is a widely used inhibitor of GSK-3β, and it is also the main drug for the treatment of bipolar disorder. Prophylactic administration of lithium chloride (2 mM/kg) can inhibit the expression of proinflammatory mediators in the hippocampus, reduce the hippocampal expression of NF-κB, and increase both the downregulation of M1 microglial-related genes (inducible nitric oxide synthase and CD86) and upregulation of M2 microglial-related genes (IL-10 and CD206), to alleviate the cognitive impairment caused by orthopedic surgery. In vitro, LiCl reversed LPS-induced production of proinflammatory mediators and M1 polarization of microglia. To sum up these results, GSK-3β is a key contributor to POCD and a potential target of neuroprotective strategies.

scholarly journals HDAC2 hyperexpression alters hippocampal neuronal transcription and microglial activity in neuroinflammation-induced cognitive dysfunction

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiao-Yu Sun ◽  
Teng Zheng ◽  
Xiu Yang ◽  
Le Liu ◽  
Shen-Shen Gao ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Histone Acetylation ◽  
Cognitive Dysfunction ◽  
Memory Impairment ◽  
Dorsal Hippocampus ◽  
Neuroprotective Effect ◽  
Memory Deficits ◽  
Peripheral Inflammation ◽  
Histone Deacetylase 2

Abstract Background Inflammation can induce cognitive dysfunction in patients who undergo surgery. Previous studies have demonstrated that both acute peripheral inflammation and anaesthetic insults, especially isoflurane (ISO), are risk factors for memory impairment. Few studies are currently investigating the role of ISO under acute peri-inflammatory conditions, and it is difficult to predict whether ISO can aggravate inflammation-induced cognitive deficits. HDACs, which are essential for learning, participate in the deacetylation of lysine residues and the regulation of gene transcription. However, the cell-specific mechanism of HDACs in inflammation-induced cognitive impairment remains unknown. Methods Three-month-old C57BL/6 mice were treated with single versus combined exposure to LPS injected intraperitoneally (i.p.) to simulate acute abdominal inflammation and isoflurane to investigate the role of anaesthesia and acute peripheral inflammation in cognitive impairment. Behavioural tests, Western blotting, ELISA, immunofluorescence, qRT-PCR, and ChIP assays were performed to detect memory, the expressions of inflammatory cytokines, HDAC2, BDNF, c-Fos, acetyl-H3, microglial activity, Bdnf mRNA, c-fos mRNA, and Bdnf and c-fos transcription in the hippocampus. Results LPS, but not isoflurane, induced neuroinflammation-induced memory impairment and reduced histone acetylation by upregulating histone deacetylase 2 (HDAC2) in dorsal hippocampal CaMKII+ neurons. The hyperexpression of HDAC2 in neurons was mediated by the activation of microglia. The decreased level of histone acetylation suppressed the transcription of Bdnf and c-fos and the expressions of BDNF and c-Fos, which subsequently impaired memory. The adeno-associated virus ShHdac2, which suppresses Hdac2 after injection into the dorsal hippocampus, reversed microglial activation, hippocampal glutamatergic BDNF and c-Fos expressions, and memory deficits. Conclusions Reversing HDAC2 in hippocampal CaMKII+ neurons exert a neuroprotective effect against neuroinflammation-induced memory deficits.

Abstract 1312: Dietary Supplementation With Sodium Valproate Attenuates Lesion Development In Hyperglycemic Apolipoprotein E-deficient Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Anna J Bowes ◽  
Mohammad I Khan ◽  
Yuanyuan Shi ◽  
Lindsie A Robertson ◽  
Geoff H Werstuck
Keyword(s):  
Valproic Acid ◽  
Er Stress ◽  
Sodium Valproate ◽  
Lipid Accumulation ◽  
Glycogen Synthase ◽  
Dietary Supplementation ◽  
Specific Cell ◽  
Lesion Volume ◽  
Atherosclerotic Lesions ◽  
Gsk 3Β

Diabetes mellitus is a major independent risk factor for cardiovascular disease and stroke however the molecular and cellular mechanisms by which diabetes contributes to the development of vascular disease are not fully understood. We have shown that conditions of hyperglycemia are associated with accumulation of glucosamine, a down stream metabolite of glucose, in specific cell types. Our findings indicate that elevated levels of intracellular glucosamine can promote endoplasmic reticulum (ER) stress in vascular cells leading to inflammation and lipid accumulation - the hallmark features of atherosclerosis. Treatment with valproic acid, a small branch chain fatty acid, can protect cultured cells from glucosamine-induced lipid accumulation by a mechanism that appears to involve inhibition of the signaling factor glycogen synthase kinase (GSK)-3. Here we evaluate the hypothesis that valproic acid can reduce the development and progression of atherosclerotic lesions in a hyperglycemic mouse model of accelerated atherosclerosis. Female apoE −/− mice were made hyperglycemic with multiple low dose injections of streptozotocin. At 15 weeks of age, hyperglycemic mice had accelerated the development of atherosclerotic lesions at the aortic root compared to normoglycemic mice. Mice fed a diet supplemented with 625 mg/kg sodium valproate had significantly reduced lesion volume relative to unsupplemented controls (4.98±0.76 versus 8.62±1.23 μm 3 , P <0.05, n =9). Valproate supplementation had no apparent effect on plasma glucose or plasma lipid levels or on the expression of diagnostic markers of ER stress in the atherosclerotic plaque. Significant reductions were observed in total hepatic lipids (>50.4%, P <0.05, n =3) and hepatic GSK-3β activity (>55.8%, P <0.05, n =3) in mice fed the valproate diet. In conclusion, dietary supplementation with low levels of sodium valproate significantly attenuates atherogenesis in hyperglycemic apoE −/− mice. This effect may involve the previously observed ability of valproate to attenuate the downstream effects of ER stress, such as GSK-3β activity.

Dorsal Hippocampus to Infralimbic Cortex Circuit is Essential for the Recall of Extinction Memory

2020 ◽  
Author(s):  
Cheng Qin ◽  
Xin-Lan Bian ◽  
Hai-Yin Wu ◽  
Jia-Yun Xian ◽  
Cheng-Yun Cai ◽  
...  
Keyword(s):  
Memory Impairment ◽  
Stress Disorder ◽  
Dorsal Hippocampus ◽  
Neural Mechanisms ◽  
Male Mice ◽  
Infralimbic Cortex ◽  
Extracellular Signal Regulated Kinase ◽  
Conditional Deletion ◽  
Extracellular Signal ◽  
Extinction Memory

Abstract Posttraumatic stress disorder subjects usually show impaired recall of extinction memory, leading to extinguished fear relapses. However, little is known about the neural mechanisms underlying the impaired recall of extinction memory. We show here that the activity of dorsal hippocampus (dHPC) to infralimbic (IL) cortex circuit is essential for the recall of fear extinction memory in male mice. There were functional neural projections from the dHPC to IL. Using optogenetic manipulations, we observed that silencing the activity of dHPC-IL circuit inhibited recall of extinction memory while stimulating the activity of dHPC-IL circuit facilitated recall of extinction memory. “Impairment of extinction consolidation caused by” conditional deletion of extracellular signal-regulated kinase 2 (ERK2) in the IL prevented the dHPC-IL circuit-mediated recall of extinction memory. Moreover, silencing the dHPC-IL circuit abolished the effect of intra-IL microinjection of ERK enhancer on the recall of extinction memory. Together, we identify a dHPC to IL circuit that mediates the recall of extinction memory, and our data suggest that the dysfunction of dHPC-IL circuit and/or impaired extinction consolidation may contribute to extinguished fear relapses.

Synthesis of Coumarin Derivatives as Versatile Scaffolds for GSK-3β Enzyme Inhibition

2020 ◽  
Vol 20 (2) ◽  
pp. 153-160 ◽  
Author(s):  
Carla S. Francisco ◽  
Clara L. Javarini ◽  
Iatahanderson de S. Barcelos ◽  
Pedro A.B. Morais ◽  
Heberth de Paula ◽  
...  
Keyword(s):  
Kinase Inhibitors ◽  
Glycogen Synthase ◽  
Synthetic Methods ◽  
Kinase Assay ◽  
Crystallographic Structure ◽  
Coumarin Derivatives ◽  
Enzymatic Production ◽  
Docking Simulations ◽  
In Silico Studies ◽  
Gsk 3Β

Background: Glycogen synthase kinase-3 (GSK-3) is involved in the phosphorylation and inactivation of glycogen synthase. GSK-3 inhibitors have been associated with a variety of diseases, including Alzheimer´s disease (AD), diabetes type II, neurologic disorders, and cancer. The inhibition of GSK-3β isoforms is likely to represent an effective strategy against AD. Objective: The present work aimed to design and synthesize coumarin derivatives to explore their potential as GSK-3β kinase inhibitors. Method: The through different synthetic methods were used to prepare coumarin derivatives. The GSK-3β activity was measured through the ADP-Glo™ Kinase Assay, which quantifies the kinasedependent enzymatic production of ADP from ATP, using a coupled-luminescence-based reaction. A docking study was performed by using the crystallographic structure of the staurosporine/GSK-3β complex [Protein Data Bank (PDB) code: 1Q3D]. Results: The eleven coumarin derivatives were obtained and evaluated as potential GSK-3β inhibitors. Additionally, in silico studies were performed. The results revealed that the compounds 5c, 5d, and 6b inhibited GSK-3β enzymatic activity by 38.97–49.62% at 1 mM. The other coumarin derivatives were tested at 1 mM, 1 µM, and 1 nM concentrations and were shown to be inhibitor candidates, with significant IC50 (1.224–6.875 µM) values, except for compound 7c (IC50 = 10.809 µM). Docking simulations showed polar interactions between compound 5b and Lys85 and Ser203, clarifying the mechanism of the most potent activity. Conclusion: The coumarin derivatives 3a and 5b, developed in this study, showed remarkable activity as GSK-3β inhibitors.

Targeting Tau Hyperphosphorylation via Kinase Inhibition: Strategy to Address Alzheimer's Disease

2020 ◽  
Vol 20 (12) ◽  
pp. 1059-1073 ◽  
Author(s):  
Ahmad Abu Turab Naqvi ◽  
Gulam Mustafa Hasan ◽  
Md. Imtaiyaz Hassan
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Glycogen Synthase ◽  
Paired Helical Filaments ◽  
Tau Hyperphosphorylation ◽  
Microtubule Stabilization ◽  
Extracellular Signal

Microtubule-associated protein tau is involved in the tubulin binding leading to microtubule stabilization in neuronal cells which is essential for stabilization of neuron cytoskeleton. The regulation of tau activity is accommodated by several kinases which phosphorylate tau protein on specific sites. In pathological conditions, abnormal activity of tau kinases such as glycogen synthase kinase-3 &#946; (GSK3&#946;), cyclin-dependent kinase 5 (CDK5), c-Jun N-terminal kinases (JNKs), extracellular signal-regulated kinase 1 and 2 (ERK1/2) and microtubule affinity regulating kinase (MARK) lead to tau hyperphosphorylation. Hyperphosphorylation of tau protein leads to aggregation of tau into paired helical filaments like structures which are major constituents of neurofibrillary tangles, a hallmark of Alzheimer’s disease. In this review, we discuss various tau protein kinases and their association with tau hyperphosphorylation. We also discuss various strategies and the advancements made in the area of Alzheimer&#039;s disease drug development by designing effective and specific inhibitors for such kinases using traditional in vitro/in vivo methods and state of the art in silico techniques.

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