Influence of Early Life Lead (Pb) Exposure on α-Synuclein, GSK-3β and Caspase-3 Mediated Tauopathy: Implications on Alzheimer’s Disease

2018 ◽  
Vol 15 (12) ◽  
pp. 1114-1122 ◽  
Author(s):  
Syed Waseem Bihaqi ◽  
Bothaina Alansi ◽  
Anwar M. Masoud ◽  
Foqia Mushtaq ◽  
Gehad M. Subaiea ◽  
...  

Background: Previously we have shown that developmental exposure to the heavy metal lead (Pb) resulted in latent cognitive impairment, upregulation of biomarkers and pathology associated with both the tau and amyloid pathways, however, the impact on Alpha Synuclein (α-Syn) and its relationship to these pathways and their connection to cognitive performance warrant further elucidation. Objective: The present study determined the impact of developmental Pb exposure on the α-Syn pathways in a mouse model knock-out (KO) for murine tau gene and in differentiated human neuroblastoma SHSY5Y cell line exposed to a series of Pb concentrations. Methods: Western blot analysis and RT-PCR were used to assess the levels of intermediates in the tau and α-Syn pathways following postnatal Pb exposure on aged mice lacking tau gene and in differentiated SHSY5Y cells on day 3 and day 6 after the Pb exposure had ceased. Result: Early life Pb exposure is accompanied by latent up-regulation in α-Syn in these mice. Furthermore, prior exposure to Pb in-vitro also resulted in an increase in α-Syn, its phosphorylated forms, as well as an increase in glycogen synthase kinase 3β (GSK-3β) and Caspase-3. Conclusion: An environmental agent can act as a latent inducer of both α-Syn and associated kinases that are involved in tau hyperphosphorylation and may allude to the interactive nature of these two neurodegenerative pathways.

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 610
Author(s):  
Robin Park ◽  
Andrew L. Coveler ◽  
Ludimila Cavalcante ◽  
Anwaar Saeed

Glycogen synthase kinase-3 beta is a ubiquitously and constitutively expressed molecule with pleiotropic function. It acts as a protooncogene in the development of several solid tumors including pancreatic cancer through its involvement in various cellular processes including cell proliferation, survival, invasion and metastasis, as well as autophagy. Furthermore, the level of aberrant glycogen synthase kinase-3 beta expression in the nucleus is inversely correlated with tumor differentiation and survival in both in vitro and in vivo models of pancreatic cancer. Small molecule inhibitors of glycogen synthase kinase-3 beta have demonstrated therapeutic potential in pre-clinical models and are currently being evaluated in early phase clinical trials involving pancreatic cancer patients with interim results showing favorable results. Moreover, recent studies support a rationale for the combination of glycogen synthase kinase-3 beta inhibitors with chemotherapy and immunotherapy, warranting the evaluation of novel combination regimens in the future.


2021 ◽  
Vol 11 (10) ◽  
pp. 1908-1917
Author(s):  
Rongkang Mai ◽  
Yiyao Cao ◽  
Huitian Yu ◽  
Yong Zheng ◽  
Juke Huang

80 male Wistar rats were stochastically assigned to Sham + Vehicle group, Sham + BUT group, PD + Vehicle group and PD + BUT group. Rotenone PD model rats were prepared by subcutaneous injection of rotenone sunflower oil emulsion 2 mg/(kg · d) for 5 consecutive weeks. Butylphthalide 80 mg/(kg · d) were given to the rats in Sham + BUT group and PD + BUT group by gavage from the first day of rotenone injection for 5 weeks. Subsequently, the motor retardation ability and the morphological changes of the substantia nigra (SN) of each group were evaluated. Meanwhile, the levels of neuronal injury, apoptosis, inflammation and oxidative stress in each group of rats were assayed. The impact of BUT treatment on miR-146a-5p expression and PI3K/AKT signal pathway in rat brain tissue was assayed. Finally, by constructing a PD cell model of the neurotoxin 6-hydroxydopamine (6-OHDA)-treated human neuroblastoma cell line SH-SY5Y, the in vitro anti-PD pharmacological effect of BUT was further verified.


Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5391
Author(s):  
Zheng Liu ◽  
Ming Bian ◽  
Qian-Qian Ma ◽  
Zhuo Zhang ◽  
Huan-Huan Du ◽  
...  

A series of novel synthetic substituted benzo[d]oxazole-based derivatives (5a–5v) exerted neuroprotective effects on β-amyloid (Aβ)-induced PC12 cells as a potential approach for the treatment of Alzheimer’s disease (AD). In vitro studies show that most of the synthesized compounds were potent in reducing the neurotoxicity of Aβ25-35-induced PC12 cells at 5 μg/mL. We found that compound 5c was non-neurotoxic at 30 μg/mL and significantly increased the viability of Aβ25-35-induced PC12 cells at 1.25, 2.5 and 5 μg/mL. Western blot analysis showed that compound 5c promoted the phosphorylation of Akt and glycogen synthase kinase (GSK-3β) and decreased the expression of nuclear factor-κB (NF-κB) in Aβ25-35-induced PC12 cells. In addition, our findings demonstrated that compound 5c protected PC12 cells from Aβ25-35-induced apoptosis and reduced the hyperphosphorylation of tau protein, and decreased the expression of receptor for AGE (RAGE), β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), inducible nitric oxide synthase (iNOS) and Bcl-2-associated X protein/B-cell lymphoma 2 (Bax/Bcl-2) via Akt/GSK-3β/NF-κB signaling pathway. In vivo studies suggest that compound 5c shows less toxicity than donepezil in the heart and nervous system of zebrafish.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1307 ◽  
Author(s):  
Eliška Kohelová ◽  
Rozálie Peřinová ◽  
Negar Maafi ◽  
Jan Korábečný ◽  
Daniela Hulcová ◽  
...  

Twelve derivatives 1a–1m of the β-crinane-type alkaloid haemanthamine were developed. All the semisynthetic derivatives were studied for their inhibitory potential against both acetylcholinesterase and butyrylcholinesterase. In addition, glycogen synthase kinase 3β (GSK-3β) inhibition potency was evaluated in the active derivatives. In order to reveal the availability of the drugs to the CNS, we elucidated the potential of selected derivatives to penetrate through the blood-brain barrier (BBB). Two compounds, namely 11-O-(2-methylbenzoyl)-haemanthamine (1j) and 11-O-(4-nitrobenzoyl)-haemanthamine (1m), revealed the most intriguing profile, both being acetylcholinesterase (hAChE) inhibitors on a micromolar scale, with GSK-3β inhibition properties, and predicted permeation through the BBB. In vitro data were further corroborated by detailed inspection of the compounds’ plausible binding modes in the active sites of hAChE and hBuChE, which led us to provide the structural determinants responsible for the activity towards these enzymes.


2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Jikui Sun ◽  
Quanfeng Ma ◽  
Banban Li ◽  
Chen Wang ◽  
Lidong Mo ◽  
...  

Abstract Accumulating evidence indicates that the dysregulation of the miRNAs/mRNA-mediated carcinogenic signaling pathway network is intimately involved in glioma initiation and progression. In the present study, by performing experiments and bioinformatics analysis, we found that RPN2 was markedly elevated in glioma specimens compared with normal controls, and its upregulation was significantly linked to WHO grade and poor prognosis. Knockdown of RPN2 inhibited tumor proliferation and invasion, promoted apoptosis, and enhanced temozolomide (TMZ) sensitivity in vitro and in vivo. Mechanistic investigation revealed that RPN2 deletion repressed β-catenin/Tcf-4 transcription activity partly through functional activation of glycogen synthase kinase-3β (GSK-3β). Furthermore, we showed that RPN2 is a direct functional target of miR-181c. Ectopic miR-181c expression suppressed β-catenin/Tcf-4 activity, while restoration of RPN2 partly reversed this inhibitory effect mediated by miR-181c, implying a molecular mechanism in which TMZ sensitivity is mediated by miR-181c. Taken together, our data revealed a new miR-181c/RPN2/wnt/β-catenin signaling axis that plays significant roles in glioma tumorigenesis and TMZ resistance, and it represents a potential therapeutic target, especially in GBM.


2016 ◽  
Author(s):  
Loraine Campanati ◽  
Luiza M. Higa ◽  
Rodrigo Delvecchio ◽  
Paula Pezzuto ◽  
Ana Luiza Valadão ◽  
...  

AbstractIn the last few months, an overwhelming number of people have been exposed to the Zika virus (ZIKV) in South and Central America. Here we showed, in vitro, that a Brazilian isolate impacts more severely murine neuronal progenitors and neurons than the African strain MR766. We found that the Brazilian isolate more pronouncedly inhibits neurite extension from neurospheres, alters their differentiation potential and causes neurons to have less and shorter processes. Comparing both lineages using a panel of inflammatory cytokines, we showed, with human neuroblastoma cells, that ZIKV induces the production of several inflammatory and chemotactic cytokines and once again, the Brazilian isolate had a more significant impact. Although much more needs to be studied regarding the association of ZIKV infection and brain damage during development, our study sheds some light into the differences between African and American lineages and the mechanisms by which the virus may be affecting neurogenesis.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Wei Wu ◽  
Xingxing Liu ◽  
Longfei Han

Abstract To evaluate the role of glycogen synthase kinase-3β (GSK-3β) in the apoptosis of cardiomyocytes in diabetic cardiomyopathy (DCM). Diabetes mellitus (DM) in rats was induced by intraperitoneal injection of 1% streptozotocin (STZ), and lithium chloride (LiCl) was used to decrease the expression of GSK-3β. Hematoxylin/eosin (HE) staining and the terminal deoxyribonucleotide transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay was conducted to evaluate the pathological injury and apoptosis of cardiomyocytes respectively. Western blot was applied to detect the protein expressions of Cleaved-caspase 3, caspase 3, Bax and Bcl-2 in rat cardiomyocytes. Real-time polymerase chain reaction (RT-PCR) was applied to detect the gene expressions of phosphoinositide 3-kinases (PI3K), Akt, and GSK-3β in rat cardiomyocytes. DM-induced cardiomyocyte injuries, which were presented as capillary basement membrane thickening, interstitial fibrosis, cardiomyocyte hypertrophy and necrosis in HE staining and increased apoptosis detected by TUNEL assay. When comparing with the control group, the mRNA expression of PI3K and Akt in DM group obviously decreased but the mRNA expression of GSK-3β obviously elevated (P < 0.05). In addition, the ratio of Cleaved-caspase 3/caspase 3 and Bax/Bcl-2 were notably increased in DM group compared with control group (P < 0.05). LiCl, as an inhibitor of GSK-3 apparently reduced the expression of GSK-3β mRNA (P < 0.05) but not the PI3K and Akt comparing with the DM group. LiCl also attenuated the myocardial injury and apoptosis induced by DM. The myocardial injury induced by DM is associated with the up-regulation of GSK-3β. LiCl inhibited the expression of GSK-3β and myocardial apoptosis in diabetic myocardium.


2020 ◽  
Vol 319 (4) ◽  
pp. G481-G493 ◽  
Author(s):  
Chethan Sampath ◽  
Shanthi Srinivasan ◽  
Michael L. Freeman ◽  
Pandu R. Gangula

Inhibition of glycogen synthase kinase 3β (GSK-3β) with SB 216763 attenuates delayed gastric emptying through gastric nuclear factor erythroid 2-related factor 2 (Nrf2) -phase II enzymes in high-fat diet-fed female mice. SB 216763 restored impaired gastric PI3K/AKT/ β-catenin/caspase 3 expression. Inhibition of GSK-3β normalized gastric dihydrofolate reductase, neuronal nitric oxide synthase-α expression, dimerization and nitrergic relaxation. SB 216763 normalized both serum estrogen and nitrate levels in female obese/Type 2 diabetes mice. SB 216763 reduced downstream signaling of GSK-3β in enteric neuronal cells in vitro.


Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 252 ◽  
Author(s):  
Hung-Chi Chang ◽  
Keng-Fan Liu ◽  
Chia-Jen Teng ◽  
Shu-Chen Lai ◽  
Shu-Er Yang ◽  
...  

Sophora species are used as dietary medicines in aging-associated symptoms. Sophora tomentosa L. (ST) is a native medicinal plant in Southeast Asia; however, there is no pharmacological literature about ST extract. The present study evaluates the antioxidant phytoconstituent contents and radical scavenging capacities of ST extract. The further investigation was to clarify the neuroprotective mechanism of ST extract against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism by assaying the activities of the dopaminergic system and antioxidant defenses, glycogen synthase kinase 3β (GSK3-β) phosphorylation, and α-synuclein levels in C57BL/6 mice. The results show that ST extract alleviated the motor deficits in MPTP-induced Parkinsonism with four behavioral tests, including a rearing locomotor, catalepsy test, balance beam walking test, and pole test. ST extract reversed the number of tyrosine hydroxylase (TH)-positive neurons in substantia nigra (SN) that had decreased by MPTP. ST extract also restored the decreased levels of dopamine and the expression of tyrosine hydroxylase (TH) in the striatum. Furthermore, ST extract restored the levels of glutathione (GSH) and the activities of antioxidant enzymes, and decreased the elevated levels of malondialdehyde (MDA) in mouse striatum. ST extract also decreased α-synuclein overexpression and GSK-3β phosphorylation in mouse striatum. In vitro, ST extract exerted higher 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging capacities through its higher phenolic contents, especially protocatechuic acid and epicatechin. These results suggest that ST extract has the potential to counteract MPTP-induced motor deficit. The neuroprotective mechanism of ST extract against MPTP-induced Parkinsonism might be related to decreasing GSK-3β phosphorylation and restoring the activities of striatal antioxidant defenses to restore the nigrostriatal dopaminergic function and decrease α-synuclein accumulation.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Ying Xin ◽  
Yang Bai ◽  
Xin Jiang ◽  
Shanshan Zhou ◽  
Yuehui Wang ◽  
...  

Aims: Sulforaphane (SFN) as a nuclear factor erythroid 2-related factor 2 (Nrf2) activator protects the heart from, and deletion of the Nrf2 gene exaggerates, the effects of diabetes. Angiotensin II (Ang II) plays a critical role in the development of diabetic cardiomyopathy; therefore, whether SFN prevents Ang II-induced cardiomyopathy through activation of Nrf2 was examined. Methods and Results: The chronic cardiac effects of Ang II with and without SFN were examined in wild-type mice, transgenic Nrf2 knockout (Nrf2-KO) mice, and mice in which cardiac tissue overexpressed Nrf2 (Nrf2-TG). The signaling pathways of SFN-mediated Nrf2 activation were examined in H9C2 cells. Administration of a subpressor dose of Ang II to WT mice induced cardiac oxidative stress, inflammation, remodeling and dysfunction, all of which could be prevented by SFN treatment, which also up-regulated Nrf2 expression and activation. Nrf2-TG mice showed resistance and Nrf2-KO mice displayed resistance to Ang II-induced cardiomyopathy. Meanwhile, the ability of SFN to protect against Ang II-induced cardiac damage was lost in Nrf2-KO mice. Up-regulation and activation of Nrf2 by SFN is accompanied by activation of AKT, inhibition of glycogen synthase kinase (GSK)-3β, and increased nuclear accumulation of Fyn. In vitro up-regulation of Nrf2 by SFN in H9C2 cells was abolished and nuclear Fyn accumulation was increased when cells were exposed to a PI3K inhibitor or GSK-3β-specific activator. Conclusion: Nrf2 plays a central role in the prevention of Ang II-induced pathological effects, and SFN can prevent Ang II-induced cardiomyopathy through activation of Nrf2 partially via the AKT/GSK-3β/Fyn pathway.


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