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Objectives: The role of glycogen synthase kinase (GSK)‐3β in adult T‐cell leukemia (ATL) caused by human T‐cell leukemia virus type 1 (HTLV‐1) is paradoxical and enigmatic. Here, we investigated the role of GSK‐3β and its potential as a therapeutic target for ATL. Methods: Cell proliferation/survival, cell cycle, apoptosis, and reactive oxygen species (ROS) generation were examined using the WST‐8 assay, flow cytometry, and Hoechst 33342 staining, respectively. Expression of GSK‐3β and cell cycle/death‐related proteins, and survival signals was analyzed using RT‐PCR, immunofluorescence staining, and immunoblotting. Results: HTLV‐1‐infected T‐cell lines showed nuclear accumulation of GSK‐3β. GSK‐3β knockdown and its inhibition with 9‐ING‐41 and LY2090314 suppressed cell proliferation/survival. 9‐ING‐41 induced G2/M arrest by enhancing the expression of γH2AX, p53, p21, and p27, and suppressing the expression of CDK1, cyclin A/B, and c‐Myc. It induced caspase‐mediated apoptosis by decreasing the expression of Bcl‐xL, Mcl‐1, XIAP, c‐IAP1/2, and survivin, and increasing the expression of Bak and Bax. 9‐ING‐41 also induced ferroptosis and necroptosis, promoted JNK phosphorylation, and suppressed IKKγ and JunB expression. It inhibited the phosphorylation of IκBα, Akt, and STAT3/5, induced ROS production, and reduced glycolysis‐derived lactate levels. Conclusion: GSK‐3β functions as an oncogene in ATL and could be a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Ischemia‐reperfusion injury (IRI) results in irreversible metabolic dysfunction and structural damage to tissues or organs, posing a formidable challenge in the field of organ implantation, cardiothoracic surgery, and general surgery. Glycogen synthase kinase‐3β (GSK‐3β) a multifunctional serine/threonine kinase, is involved in a variety of biological processes, including cell proliferation, apoptosis, and immune response. Phosphorylation of its tyrosine 216 and serine 9 sites positively and negatively regulates the activation and inactivation of the enzyme. Significantly, inhibition or inactivation of GSK‐3β provides protection against IRI, making it a viable target for drug development. Though numerous GSK‐3β inhibitors have been identified to date, the development of therapeutic treatments remains a considerable distance away. In light of this, this review summarizes the complicated network of GSK‐3β roles in IRI. First, we provide an overview of GSK‐3β's basic background. Subsequently, we briefly review the pathological mechanisms of GSK‐3β in accelerating IRI, and highlight the latest progress of GSK‐3β in multiorgan IRI, encompassing heart, brain, kidney, liver, and intestine. Finally, we discuss the current development of GSK‐3β inhibitors in various organ IRI, offering a thorough and insightful reference for GSK‐3β as a potential target for future IRI therapy. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a major common neurodegenerative disease characterized by progressive memory loss and decline in cognitive function, leading to dementia. Unlike pharmacological therapies, which are targeted toward symptoms, cell-based therapies target the underlying causes of AD. Therapies using mesenchymal stem cells (MSC) that target several important proteins such as calpains, glycogen synthase kinase 3-beta (GSK3β), and ryanodine receptor 3 (RYR3) related to amyloid-beta (Aβ) which contribute to AD pathophysiology need further investigation. This systematic review explored studies that examined the effects of MSC on the expression of calpains, GSK3β, and RYR3 in mouse models of AD. A literature search of Medline/PubMed electronic database identified seven studies that met the inclusion criteria. These studies suggested that MSC may be associated with reduced GSK3β activity in AD mice by activating its inhibitory pathway and suppressing its activation pathway. MSC could also suppress RYR3 expression in AD mice, reducing calcium (Ca2+) levels in the cytosol. The beneficial effects of reduced GSK3β and RYR3 activity after MSC treatment include improved cognitive function, and reduced tau phosphorylation and Aβ plaques in AD mice. This systematic review emphasizes the need for further research on which MSC types, doses, and administration routes are most effective, as well as the immune response and effects in humans. [ABSTRACT FROM AUTHOR]

Endothelial-mesenchymal transition (EndMT) drives endothelium to contribute to atherosclerotic calcification. In a previous study, we showed that glycogen synthase kinase-3β (GSK3β) inhibition induced β-catenin and reduced mothers against DPP homolog 1 (SMAD1) in order to redirect osteoblast-like cells towards endothelial lineage, thereby reducing vascular calcification in Matrix Gla Protein (Mgp) deficiency and diabetic Ins2Akita/wt mice. Here, we report that GSK3β inhibition or endothelial-specific deletion of GSK3β reduces atherosclerotic calcification. We also find that alterations in β-catenin and SMAD1 induced by GSK3β inhibition in the aortas of Apoe-/- mice are similar to Mgp-/- mice. Together, our results suggest that GSK3β inhibition reduces vascular calcification in atherosclerotic lesions through a similar mechanism to that in Mgp-/- mice.

Purpose: Osthole possesses anti-tumor activities. However, whether osthole can have a radiosensitization effect on hepatic cancer remains unclear. Here, an HCC-LM3 cells-inoculated subcutaneous transplanted tumor was adopted to explore the effect of osthole. Methods: The tumor-bearing mice were treated with 100 mg/kg osthole for 12 days, 4 Gy irradiation twice, or their combination. The tumor volume and weight, lactic acid content, glycolytic enzyme activities, and protein expression of glycogen synthase kinase 3β (GSK-3β), p‑GSK-3β, mammalian target of rapamycin (mTOR), p‑mTOR, AMP-activated protein kinase (AMPK), p‑AMPK, glucose transporter 1/3, and pyruvate kinase M2 were determined. The GSK-3β-overexpressed HCC-LM3 or SK-Hep‑1 cell models were also adopted to verify the effects of osthole on expression of these proteins. Results: The tumor volume and weight, lactic acid content, and glycolytic enzyme activities in tumor tissues were lower in the osthole + radiation group than in the radiation group. Moreover, osthole could reverse the radiation-induced increments of p‑GSK-3β/GSK-3β and p‑mTOR/mTOR protein ratios and the expression of glucose transporter 1/3 and pyruvate kinase M2 proteins in tumor tissues, and increase the protein ratio of p‑AMPK/AMPK. The effects of osthole on these glycolysis-related proteins were also observed in GSK-3β-overexpressed HCC-LM3 or SK-Hep‑1 cell models. Conclusion: Osthole has a radiosensitizing effect on subcutaneous transplanted hepatocellular carcinoma, and its mechanism may be related to inhibition of GSK-3β/AMPK/mTOR pathway-controlled glycolysis. [ABSTRACT FROM AUTHOR]

Aim: Both the activation of glycogen synthase kinase‐3β (GSK‐3β) and the presence of ApoE ε4 genotype have been found to respectively correlate with cognitive decline in patients with type 2 diabetes mellitus (T2DM), who further show a high incidence of developing Alzheimer's disease. However, the relationship between ApoE ε4 and GSK‐3β in the cognitive impairment of T2DM patients remains unclear. Methods: ApoE genotypes and platelet GSK‐3β level were measured in 1139 T2DM patients recruited from five medical centers in Wuhan, China. Cognitive functions were assessed by Mini‐Mental State Examination (MMSE). The association and the relationships among apolipoprotein E (ApoE) genotypes, GSK‐3β activity and cognitive function were analyzed by regression and mediating effect analyses, respectively. Results: T2DM patients with ApoE ε4 but not ApoE ε2 haplotype showed poorer cognitive function and elevated platelet GSK‐3β activity, when using ApoE ε3 as reference. The elevation of GSK‐3β activity was positively correlated the diabetes duration, as well as plasma glycated hemoglobin (HbA1c) and glucose levels. Moreover, correlation and regression analysis also revealed significant pairwise correlations among GSK‐3β activity, ApoE gene polymorphism and cognitive function. Lastly, using Baron and Kenny modeling, we unveiled a mediative role of GSK‐3β activity between ApoE ε4 and cognitive impairment. Conclusion: We reported here that the upregulation of GSK‐3β activity mediates the exacerbation of cognitive impairment by ApoE ε4‐enhanced cognitive impairment in T2DM patients, suggesting GSK‐3β inhibitors as promising drugs for preserving cognitive function in T2DM patients, especially to those with ApoE ε4 genotype. [ABSTRACT FROM AUTHOR]

BackgroundOur previous multicenter case-control study showed that aging, up-regulation of platelet glycogen synthase kinase-3β (GSK-3β), impaired olfactory function, and ApoE ϵ4 genotype were associated with cognitive decline in type 2 diabetes mellitus (T2DM) patients. However, the causal relationship between these biomarkers and the development of cognitive decline in T2DM patients remains unclear.MethodsTo further investigate this potential relationship, we designed a 6-year follow-up study in 273 T2DM patients with normal cognitive in our previous study. Baseline characteristics of the study population were compared between T2DM patients with and without incident mild cognitive impairment (MCI). We utilized Cox proportional hazard regression models to assess the risk of cognitive impairment associated with various baseline biomarkers. Receiver operating characteristic curves (ROC) were performed to evaluate the diagnostic accuracy of these biomarkers in predicting cognitive impairment.ResultsDuring a median follow-up time of 6 years (with a range of 4 to 9 years), 40 patients (16.13%) with T2DM developed MCI. Participants who developed incident MCI were more likely to be older, have a lower education level, have more diabetic complications, a higher percentage of ApoE ϵ4 allele and a higher level of platelet GSK-3β activity (rGSK-3β) at baseline (P

Study Design. Histologic analysis of the ligamentum flavum (LF) in the lumbar spine. Objective. The objective of this study is to investigate the levels of glycogen synthase kinase-3β (GSK-3β) and β-catenin in the LF tissue of patients with lumbar spinal stenosis (LSS). Summary of Background Data. The hypertrophy of the LF is the primary cause of the progression of LSS. Recently, Wnt signaling has been proposed as one of the molecular processes contributing to LF hypertrophy. GSK-3β and β-catenin are recognized to play a crucial part in the control of this signaling pathway. Materials and Methods. From May 2020 to July 2022, LF from 51 LSS patients (LSS group) and 18 lumbar disc herniation patients (control group) were prospectively collected during surgery. Histologic analysis was investigated to confirm the progression of LF fibrosis. The levels of α-smooth muscle actin, phosphorylation of GSK-3β (p-GSK-3β; inactive form), and β-catenin were analyzed in LF withWestern blot analysis to reveal the GSK-3β/β-catenin signaling pathway. Continuous variables are expressed as mean±SD and compared using the student t test. Categorical variables are compared using the χ² test or Fisher exact test, as appropriate. To determine the association between p-GSK-3β and LF thickness, the Pearson correlation coefficient was calculated based on the results of Western blot analysis. Results. The LSS group was older and had thicker LF than the controls. The LSS group showed increased collagen fiber and cellularity than the controls. The levels of α-smooth muscle actin, p-GSK-3β, and β-catenin in the LF of the LSS group were significantly higher than that of the control group. There was a strong positive correlation between p-GSK-3β (Ser9) level and LF thickness in LSS patients (r=0.69, P= 0.01). Conclusion. This research proposes a molecular mechanism for the pathogenesis of LF hypertrophy in LSS. Specifically, GSK-3β/β-catenin signaling appears to be related to LF hypertrophy in LSS and a positive correlation exists between p-GSK-3β level and LF thickness. [ABSTRACT FROM AUTHOR]

Background: Tau phosphorylation is a pathological hallmark of Alzheimer's disease (AD). Previously, we reported that the γ-adducin 1-357 fragment is present in the brains of AD patients. However, it remains unknown how γ-adducin regulates tau phosphorylation. Objective: The aim of this project is to investigate the effects of the γ-adducin 1-357 fragment on tau phosphorylation and the kinases involved in this process. Methods: Full-length γ-adducin or the γ-adducin 1-357 fragment was expressed in HEK293 cells, SH-SY5Y cells, and primary neurons. The phosphorylation of tau Ser396 was determined using Western blot and immunofluorescence. Tau P301S transgenic mice were injected with adeno-associated virus encoding full-length γ-adducin or γ-adducin 1-357 fragment to determine the phosphorylation of tau. Results: The γ-adducin 1-357 fragment enhances tau phosphorylation at Ser396. Additionally, the expression of the γ-adducin 1-357 fragment leads to the activation of glycogen synthase kinase-3β (GSK-3β). This effect was mitigated by the GSK-3β inhibitor 4-Benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8). Conclusion: The γ-adducin 1-357 fragment enhances tau phosphorylation by activating GSK3β. These results support that the fragmentation of γ-adducin may play a pivotal role in tau pathology. [ABSTRACT FROM AUTHOR]

Endothelial-mesenchymal transition (EndMT) drives endothelium to contribute to atherosclerotic calcification. In a previous study, we showed that glycogen synthase kinase-3β (GSK3β) inhibition induced β-catenin and reduced mothers against DPP homolog 1 (SMAD1) in order to redirect osteoblast-like cells towards endothelial lineage, thereby reducing vascular calcification in Matrix Gla Protein (Mgp) deficiency and diabetic Ins2Akita/wt mice. Here, we report that GSK3β inhibition or endothelial-specific deletion of GSK3β reduces atherosclerotic calcification. We also find that alterations in β-catenin and SMAD1 induced by GSK3β inhibition in the aortas of Apoe−/− mice are similar to Mgp−/− mice. Together, our results suggest that GSK3β inhibition reduces vascular calcification in atherosclerotic lesions through a similar mechanism to that in Mgp−/− mice. [ABSTRACT FROM AUTHOR]

Long-term hypercaloric intake such as a high-fat diet (HFD) could act as negative regulators on bone remodeling, thereby inducing bone loss and bone microarchitecture destruction. Currently, food-derived natural compounds represent a promising strategy to attenuate HFD-induced bone loss. We previously prepared a whey protein hydrolysate (WPH) with osteogenic capacity. In this study, we continuously isolated and identified an osteogenic and antioxidant octapeptide TPEVDDA from WPH, which significantly promoted the alkaline phosphatase activities on MC3T3-E1 cells and exerted DPPH radical scavenging capacity. We then established an HFD-fed obese mice model with significantly imbalanced redox status and reduced bone mass and further evaluated the effects of different doses of WPH on ameliorating the HFD-induced bone loss and oxidative damages. Results showed that the administration of 2% and 4% WPH for 12 weeks significantly restored perirenal fat mass, improved serum lipid levels, reduced oxidative stress, and promoted the activity of antioxidant enzymes; meanwhile, WPH significantly preserved bone mass and bone mechanical properties, attenuated the degradation of trabecular microstructure, and regulated serum bone metabolism biomarkers. The protein levels of Runx2, Nrf2, and HO-1, as well as the phosphorylation level of GSK-3β in tibias, were notably activated by WPH. Overall, we found that the potential mechanism of WPH on ameliorating the HFD-induced bone loss mainly through its antioxidant and osteogenic capacity by activating Runx2 and GSK-3β/Nrf2 signaling pathway, demonstrating the potential of WPH to be used as a nutritional strategy for obesity and osteoporosis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Glycogen synthase kinase-3ß (GSK3β), fat mass and obesity-associated protein (FTO), and toll-like receptors 4 (TLR4) take on critical significance in different biological processes, whereas their interactions remain unclear. The objective was the investigation of the interaction effect in cerebral ischemia-reperfusion (I/R) injury. METHODS: The function of the cerebral cortex in the mouse middle cerebral artery occlusion (MCAO) model (each group n = 6) and P12 cells oxygen-glucose deprivation/reoxygenation (OGD/R) model was analyzed using short hairpin GSK3β lentivirus and overexpression of FTO lentivirus (in vitro), TLR4 inhibitor (TAK242), and LiCl to regulate GSK3β, FTO, TLR4 expression, and GSK3β activity, respectively. RESULTS: After GSK3β knockdown in the OGD/R model of PC12 cells, the levels of TLR4 and p-p65 were lower than in the control, and the level of FTO was higher than in the control. Knockdown GSK3β reversed the OGD/R-induced nuclear factor kappa-B transfer to the intranuclear nuclei. As indicated by the result, TLR4 expression was down-regulated by overexpressed FTO, and TLR4 expression was up-regulated notably after inhibition of FTO with the use of R-2HG. After the inhibition of the activity of GSK3β in vivo, the reduction of FTO in mice suffering from MCAO was reversed. CONCLUSIONS: Our research shows that GSK3β/FTO/TLR4 pathway contributes to cerebral I/R injury. [ABSTRACT FROM AUTHOR]

BackgroundAluminum (Al) can cause irreversible damage to neurons and synapses function, and the mechanism may be connected to mitochondrial damage caused by glycogen synthase kinase-3β (GSK-3β) regulating dynamin-related protein 1 (DRP1), resulting in inhibition of the growth of neuronal protrusions.ObjectiveTo investigate the role of GSK-3β regulating DRP1 in the inhibition of primary hippocampal neurite growth induced by Al.MethodsNeurons were extracted from the hippocampus of newborn mice (≤24 h old) for primary culture. On day 6, the purity of neurons was detected by immunofluorescence. On day 10, neurons with good growth state were selected for Al exposure and GSK-3β inhibitor SB216763 (SB) intervention. The experiment design included a blank control group, a dimethyl sulfoxide (DMSO) group, an Al (20 μmol·L−1) group, a SB (1 μmol·L−1) group, and a SB (1 μmol·L−1) + Al (20 μmol·L−1) group. After primary hippocampal neurons were treated with Al or SB for 48 h, cell viability was detected by CCK-8 assay, the mitochondrial morphology of primary hippocampal neurons was observed by transmission electron microscopy, the total protrusion length of primary hippocampal neurons was scanned and analyzed by laser confocal imaging, and their complexity was analyzed by Sholl analysis. The expression levels of phospho-GSK-3β, GSK-3β, and DRP1 were detected by Western blotting.ResultsThe immunofluorescent results showed that the purity of primary neurons was higher than 90%. After the Al exposure and the SB intervention for 48 h, compared with the blank control group, there was no obvious difference in cell viability in the DMSO group and the SB group (P>0.05), and the Al group showed reduced cell viability (P=0.006); there was no obvious difference in cell viability between the SB+Al group and the Al group (P>0.05). Compared with the blank control group, there was no obvious difference in the average total length of protrusion in the DMSO group and the SB group (P>0.05), and the Al group showed reduced average total length of neurite (P0.05), and that in the Al group was significantly reduced (P0.05). The mitochondrial structure of the blank control group was complete and the crest was clearly visible; there was no apparent variation in the mitochondrial structure in the DMSO group and the SB group; the mitochondria in the Al group were vacuolated and the crista disappeared; the SB+Al group showed clearer crista than the Al group. The difference in GSK-3β phosphorylation level among groups was statistically significant (F=45.841, P0.05), increased in the SB group (P=0.022), and significantly reduced in the Al group (P0.05), and significantly increased in the Al group (P=0.001); the DRP1 protein level in the SB+Al group was significantly lower than that in the Al group (P=0.029).ConclusionAl may increase the level of DRP1 protein by activating GSK-3β, causing mitochondrial damage and inhibiting neuronal protrusions growth.

AIM: To explore the effect of xanthohumol （Xn） on arthritis pain in rats and its mechanism. METHODS: Sprague-Dawley rats were randomly divided into three groups （10 rats per group）: control group, complete Freund's adjuvant （CFA） group, and CFA+Xn group. A CFA mouse model was established through intra-articular injection with 10 μL CFA into the left hind knee joint, and Xn（ 5 mg/kg） was then intrathecally injected into the rats. Pain behavior and motor ability changes in the rats were recorded. Auto-dock was used for analyzing the binding between Xn and glycogen synthase kinase 3β （GSK-3β）, while immunofluorescence and Western blot analysis were used for detecting the expression and activity of GSK-3β, astrocyte status, nuclear factor-κB （NF-κB） level, and interleukin-1β （IL-1β） expression in the spinal cord tissue of the rats. ELISA was used for measuring the serum levels of IL-1β and tumor necrosis factor-α （TNF-α）. RESULTS: Compared with control group, treatment with CFA increased the number of flinches, decreased the mechanical threshold, and impaired motor ability （P<0. 05）. The levels of phosphorylated GSK-3β, astrocyte marker glial fibrillary acidic protein （GFAP）, NF-κB, and IL-1β were increased in the spinal cords of the rats in CFA group（ P<0. 05）. The serum levels of IL-1β and TNF-α were up-regulated in CFA group（ P<0. 05）. Compared with CFA group, intrathecal administration of Xn reduced the number of spontaneous foot contractions, up-regulated mechanical pain threshold, and increased stay time and motor distance of the rotating rod （P<0. 05）. Molecular docking analysis found Xn to inhibit GSK-3β activity. Compared with CFA group, Xn administration significantly attenuated serum inflam‐mation in the rats （P<0. 05）, and significantly reduced GSK-3β activity and the expression levels of GFAP, NF-κB and IL-1β （P<0. 05）. CONCLUSION: Xanthohumol inhibits NF-κB/IL-1β inflammatory signaling by blocking GSK-3β, thus alleviating arthritis pain in rats. [ABSTRACT FROM AUTHOR]

Formaldehyde (FA) has been found to induce major Alzheimer's disease (AD)-like features including cognitive impairment, Aβ deposition, and Tau hyperphosphorylation, suggesting that it may play a significant role in the initiation and progression of AD. Therefore, elucidating the mechanism underlying FA-induced neurotoxicity is crucial for exploring more comprehensive approaches to delay or prevent the development of AD. Mangiferin (MGF) is a natural C-glucosyl-xanthone with promising neuroprotective effects, and is considered to have potential in the treatment of AD. The present study was designed to characterize the effects and mechanisms by which MGF protects against FA-induced neurotoxicity. The results in murine hippocampal cells (HT22) revealed that co-treatment with MGF significantly decreased FA-induced cytotoxicity and inhibited Tau hyperphosphorylation in a dose-dependent manner. It was further found that these protective effects were achieved by attenuating FA-induced endoplasmic reticulum stress (ERS), as indicated by the inhibition of the ERS markers, GRP78 and CHOP, and downstream Tau-associated kinases (GSK-3β and CaMKII) expression. In addition, MGF markedly inhibited FA-induced oxidative damage, including Ca2+ overload, ROS generation, and mitochondrial dysfunction, all of which are associated with ERS. Further studies showed that the intragastric administration of 40 mg/kg/day MGF for 6 weeks significantly improved spatial learning ability and long-term memory in C57/BL6 mice with FA-induced cognitive impairment by reducing Tau hyperphosphorylation and the expression of GRP78, GSK-3β, and CaMKII in the brains. Taken together, these findings provide the first evidence that MGF exerts a significant neuroprotective effect against FA-induced damage and ameliorates mice cognitive impairment, the possible underlying mechanisms of which are expected to provide a novel basis for the treatment of AD and diseases caused by FA pollution. [ABSTRACT FROM AUTHOR]

Triggering receptor expressed on myeloid cells-2 (TREM2), a cell surface receptor mainly expressed on microglia, has been shown to play a critical role in Alzheimer's disease (AD) pathogenesis and progression. Our recent results showed that overexpression of TREM2 inhibited inflammatory response in APP/PS1 mice and BV2 cells. Several studies indicated that TREM2 ameliorated tau hyperphosphorylation might be ascribed to the inhibition of neuroinflammation. However, the precise signaling pathways underlying the effect of TREM2 on tau pathology and neuronal apoptosis have not been fully elucidated. In the present study, upregulation of TREM2 significantly inhibited tau hyperphosphorylation at Ser199, Ser396, and Thr205, respectively, as well as prevented neuronal loss and apoptosis. We also found that upregulation of TREM2 alleviated behavioral deficits and improved the spatial cognitive ability of APP/PS1 mice. Further study revealed that TREM2 could activate phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway, resulting in an inhibitory effect on glycogen synthase kinase-3β (GSK-3β), which is a major kinase responsible for tau hyperphosphorylation in AD. In line with in vivo findings, TREM2-overexpressing BV2 microglia following β-amyloid (Aβ) stimulation led to a significant increase in the phosphorylation of PI3K, Akt, and GSK-3β, accompanied by a decrease in tau hyperphosphorylation and apoptosis in co-cultured SH-SY5Y cells. Furthermore, LY294002, a specific PI3K inhibitor, was observed to abolish the beneficial effects of TREM2 on tau hyperphosphorylation, neuronal apoptosis, and spatial cognitive impairments in vivo and in vitro. Thus, our findings indicated that TREM2 inhibits tau hyperphosphorylation and neuronal apoptosis, at least in part, by the activation of the PI3K/Akt/GSK-3β signaling pathway. Taken together, the above results allow us to better understand how TREM2 protects against tau pathology and suggest that upregulation of TREM2 may provide new ideas and therapeutic targets for AD. [ABSTRACT FROM AUTHOR]

Dysregulated microRNA (miRNA) expression in the brain can contribute to cognitive dysfunction and aberrant tau hyperphosphorylation in Alzheimer’s disease (AD). Several studies have reported a role for microRNA-23b-3p (miR-23b-3p) in various neurologic disorders; however, its involvement in cognition-related functions remains unclear. In the present study, we investigated the potential therapeutic effects and mechanisms of miR-23b-3p in AD. miRNA profiles in the cortex of amyloid precursor protein (APP)/presenilin 1 (PS1) double transgenic mice (APP/PS1 mice) demonstrated that miR-23b-3p was reduced. This decrease was verified in APPswe cells, SAMP8 mouse brains, and plasma from AD patients. Furthermore, glycogen synthase kinase-3β (GSK-3β), a major tau kinase implicated in tau pathology, was identified as a target of miR-23b-3p. Functional in vivo studies demonstrated that intracerebroventricular delivery of miR-23b-3p in APP/PS1 mice ameliorated cognitive deficits, histopathological changes, and tau phosphorylation immunoreactivity at several sites by inhibiting GSK-3β expression and activation. Similarly, the upregulation of miR-23b-3p in APPswe cells inhibited GSK-3β-mediated tau hyperphosphorylation, Aβ1-42 generation, and neuronal apoptosis, resulting in the suppression of the GSK-3β/p-tau and Bax/caspase-3 pathways. Collectively, our findings strongly support the hypothesis that miR-23b-3p plays a neuroprotective role in AD, thereby identifying miR-23b-3p as a promising therapeutic target for AD.

Purpose: To evaluate the protective effect, effective time window, and mechanism of protection of sevoflurane post-conditioning and late sevoflurane post-conditioning on heart muscle ischemiareperfusion (I/R) lesion in isolated rat heart. Methods: Langendorff isolated perfusion model was established in Sprague-Dawley (SD) rats. After 15 min of stabilization, the rats were assigned to 10 groups, based on the treatments given: control group (TTC), I/R group, sevoflurane post-processing group (SpostC), 0.5 min-, 1 min-, 5 min-, 10 min-, 20 min-, 30 min-delayed sevoflurane post-processing group (S0.5, S1, S3, S5, S10, and S20). The levels of mitochondrial membrane permeability, area of myocardial infarction, myocardial apoptosis, and p-GSK-3 beta level were determined. Results: Myocardial infarction areas in Spost, S0.5, S1, S3, S5, S10 and S20 groups were significantly than in I/R group (p < 0.05), while expression levels of myocardial p-Akt were significantly higher in Spost, S0.5, S1, S3, S5, S10, S20, and S30 groups than in I/R group (p < 0.05). GSK-3 phosphorylation level was significantly higher in Spost, S1, S10, S20, and S30 groups than in I/R group (p < 0.05). Expression of p-GSK-3β in S30 group decreased, relative to that in Spost group (p < 0.05). Conclusion: Sevoflurane post-conditioning and delayed sevoflurane post-conditioning mitigates I/R lesions in isolated rat hearts. The protective effect against ischemia-reperfusion injury is related to the levels of phosphorylation of Akt and GSK-3β. Thus, this treatment approach may be useful in the management of cardiac ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Aim: Cardiac autonomic nervous system (ANS) dysregulation is a hallmark of several cardiovascular diseases. Adrenergic signaling enhanced cardiomyocyte cohesion via PKA‐mediated plakoglobin phosphorylation at serine 665, referred to as positive adhesiotropy. This study investigated cholinergic regulation of cardiomyocyte cohesion using muscarinic receptor agonist carbachol (CCH). Methods: Dissociation assays, Western blot analysis, immunostaining, atomic force microscopy (AFM), immunoprecipitation, transmission electron microscopy (TEM), triton assays, and siRNA knockdown of genes were performed in either HL‐1 cells or plakoglobin (PG) wild type (Jup+/+) and knockout (Jup−/−) mice, which served as a model for arrhythmogenic cardiomyopathy. Results: In HL‐1 cells grown in norepinephrine (NE)‐containing medium for baseline adrenergic stimulation, and murine cardiac slice cultures from Jup+/+ and Jup−/− mice CCH treatment impaired cardiomyocyte cohesion. Immunostainings and AFM experiments revealed that CCH reduced desmoglein 2 (DSG2) localization and binding at cell borders. Furthermore, CCH reduced intercalated disc plaque thickness in both Jup+/+ and Jup−/−mice, evidenced by TEM analysis. Immunoprecipitation experiments in HL‐1 cells revealed no changes in DSG2 interaction with desmoplakin (DP), plakophilin 2 (PKP2), PG, and desmin (DES) after CCH treatment. However, knockdown of any of the above proteins abolished CCH‐mediated loss of cardiomyocyte cohesion. Furthermore, in HL‐1 cells, CCH inhibited adrenergic‐stimulated ERK phosphorylation but not PG phosphorylation at serine 665. In addition, CCH activated the AKT/GSK‐3β axis in the presence of NE. Conclusion: Our results demonstrate that cholinergic signaling antagonizes the positive effect of adrenergic signaling on cardiomyocyte cohesion and thus causes negative adhesiotropy independent of PG phosphorylation. [ABSTRACT FROM AUTHOR]

Human papillomavirus (HPV) infection‐dependent cervical cancer is one of the most common gynecological cancers and often becomes aggressive, with rapid proliferation, invasion/migration, and drug resistance. Here, 135 fresh human cervical squamous cell carcinoma (CSCC) tissue specimens, comprising 21 adjacent normal (AN), 30 cervical intraepithelial neoplasia (CIN1–3), 45 CSCC, and 39 drugs (chemo‐radiation)‐resistant cervical tumor (DRCT) tissues were included. HPV‐positive (HeLa, SiHa), HPV‐negative (C33A), and cisplatin‐resistant (CisR–HeLa/–SiHa/–C33A) cell lines were used for in vitro studies. HPV16/18 oncoproteins E6/E7, pERK1/2, and glycogen synthase kinase‐3 (GSK3) and the matrix metalloproteinases (MMPs) MMP‐9/‐2 were assessed using immunohistochemistry, WB, and gelatin zymography. HPV16/18 infection was observed in 16.7% of the CIN1‐3, 77.8% of the CSCC, and 89.7% of DRCT samples. Total and inactive GSK3β expressions were associated with overall CSCC progression (p = 0.039 and p = 0.024, respectively) and chemoresistance (p = 0.004 and p = 0.014, respectively). Positive correlations were observed, between the expression of E6 and pGSK3β expression (p = 0.013); E6 and CSCC progression (p < 0.0001)/drug resistance (p = 0.0001). CisR–HeLa/–SiHa was more dependent on pGSK3β, and activation of GSK3 by SMIs (iAkt), treatment with nimbolide, or knockdown of E6/E7 reduced cisplatin resistance and promoted apoptosis. Hence, the activation of GSK3β with nimbolide and iAkt can be exploited for therapeutic interventions of cervical cancer. [ABSTRACT FROM AUTHOR]

BackgroundAluminum can induce irreversible structural and synaptic functional damage, and the associated mechanism may be related to the neurite damage regulated by glycogen synthase kinase-3β (GSK-3β)/collapsin response mediator protein 2 (CRMP2).ObjectiveThis experiment is conducted to investigate the effect of aluminum-maltolate [Al(mal)3] on primary hippocampal neuron neurites in mice, and reveal the role of GSK-3β-CRMP2 in this process.MethodsThe hippocampus of newborn ICR mice (≤ 24 h old) was used for primary neuronal cultures. On the 5th day in vitro (DIV5), neuron purity detection were performed by confocal laser scanning microscopy. On DIV7, the neurons were transfected with lentiviral vector-mediated mNeonGreen. On DIV10, the neurons with mNeonGreen fluorescence in good growth state were treated with Al(mal)3. The stage I experimental groups were blank control group, maltol group, 10 µmol·L−1 Al group, 20 µmol·L−1 Al group, and 40 µmol·L−1 Al group. Then 20 µmol·L−1 Al was used to establish a model of neurite injury and for the intervention. The stage II experimental groups were blank control group, dimethyl sulfoxide (DMSO) group, Al (20 µmol·L−1) group, SB (GSK-3β inhibitor, 1 µmol·L−1), and SB (1 µmol·L−1)+Al (20 µmol·L−1) group. CCK-8 method was used to detect the viability of neurons. The primary hippocampal neurons of mice were scanned with high content analysis system at 0 h and 48 h after Al or SB treatment, and the density and length of neurites were analyzed. Western blotting was used to detect the expression and phosphorylation levels of CRMP2 and GSK-3β in primary hippocampal neurons of mice.ResultsThe immunofluorescence results showed that the purity of primary neurons was more than 90%. Compared with the blank control group in stage I, the cell viability rates of the 10, 20, and 40 µmol·L−1 Al groups were decreased after 48h of Al(mal)3 treatment (P

Alzheimer's Disease (AD) is one of the significant diseases of the aging population and affects Central Nervous System dominantly. Blood-brain-barrier permeation is a substantial complication in developing CNS drugs, and it is considered challenging with minimal success rates. Although Glycogen synthase kinase-3β (GSK-3β) is an attractive disease-modifying target for AD, there is no single GSK-3β inhibitor in clinical trials for AD. Here we performed structure-based virtual screening on the Chembridge CNS-Set library compounds. 10 hits were identified based on interaction, binding energy, dock score, and a potential ADME profile. These 10 chosen compounds were then investigated for in vitro kinase inhibitory activity against GSK-3β and other AD-related kinases. Among these, the molecule 7114202 showed 48% GSK-3β inhibition while showing selectivity over other AD-related kinases. Molecular dynamic simulations of apoenzyme, co-crystallized molecule, and 7114202 validated the Lys85, Val135, Leu188, Asp200 located in the active site of enzyme play a significant role in GSK-3β complex formation with inhibitors, and they are responsible for activity and selectivity. The in vitro studies also revealed a potent and selective Casein Kinase 1ε (CK1ε) inhibitor 7774767 with IC50 5.10 µM. [ABSTRACT FROM AUTHOR]

Bone is the preferential site of metastasis for breast cancer. Invasion of cancer cells induces the destruction of bone tissue and damnification of peripheral nerves and consequently induced central sensitization which contributes to severe pain. Herein, cancer induced bone pain (CIBP) rats exhibited destruction of tibia, mechanical allodynia and spinal inflammation. Inflammatory response mainly mediated by astrocyte and microglia in central nervous system. Our immunofluorescence analysis revealed activation of spinal astrocytes and microglia in CIBP rats. Transmission electron microscopy (TEM) observations of mitochondrial outer membrane disruption and cristae damage in spinal mitochondria of CIBP rats. Proteomics analysis identified abnormal expression of proteins related to mitochondrial organization and function. Intrathecally, injection of GSK‐3β activity inhibitor TDZD‐8 significantly attenuated Drp1‐mediated mitochondrial fission and recovered mitochondrial function. Inhibition of GSK‐3β activity also suppressed NLRP3 inflammasome cascade and consequently decreased mechanical pain sensitivity of CIBP rats. For cell research, TDZD‐8 treatment significantly reversed TNF‐α induced mitochondrial membrane potential (MMP) deficiency and high mitochondrial reactive oxygen species level. Taken together, GSK‐3β inhibition by TDZD‐8 decreases spinal inflammation and relieves cancer induced bone pain via reducing Drp1‐mediated mitochondrial damage. [ABSTRACT FROM AUTHOR]

Abstract Background Propofol, an intravenous anesthetic, was proven to protect against lung ischemia/reperfusion (I/R) injury. However, the detailed mechanism of Propofol in lung I/R injury is still elusive. This study was designed to explore the therapeutic effects of Propofol, both in vivo and in vitro, on lung I/R injury and the underlying mechanisms related to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-144 (miR-144)/glycogen synthase kinase-3β (GSK3β). Methods C57BL/6 mice were used to establish a lung I/R injury model while pulmonary microvascular endothelial cells (PMVECs) were constructed as hypoxia/reperfusion (H/R) cellular model, both of which were performed with Propofol treatment. Gain- or loss-of-function approaches were subsequently employed, followed by observation of cell apoptosis in lung tissues and evaluation of proliferative and apoptotic capabilities in H/R cells. Meanwhile, the inflammatory factors, autophagosomes, and autophagy-related proteins were measured. Results Our experimental data revealed that Propofol treatment could decrease the elevated expression of MALAT1 following I/R injury or H/R induction, indicating its protection against lung I/R injury. Additionally, overexpressing MALAT1 or GSK3β promoted the activation of autophagosomes, proinflammatory factor release, and cell apoptosis, suggesting that overexpressing MALAT1 or GSK3β may reverse the protective effects of Propofol against lung I/R injury. MALAT1 was identified to negatively regulate miR-144 to upregulate the GSK3β expression. Conclusion Overall, our study demonstrated that Propofol played a protective role in lung I/R injury by suppressing autophagy and decreasing release of inflammatory factors, with the possible involvement of the MALAT1/miR-144/GSK3β axis.

Formaldehyde (FA) has been found to induce major Alzheimer’s disease (AD)-like features including cognitive impairment, Aβ deposition, and Tau hyperphosphorylation, suggesting that it may play a significant role in the initiation and progression of AD. Therefore, elucidating the mechanism underlying FA-induced neurotoxicity is crucial for exploring more comprehensive approaches to delay or prevent the development of AD. Mangiferin (MGF) is a natural C-glucosyl-xanthone with promising neuroprotective effects, and is considered to have potential in the treatment of AD. The present study was designed to characterize the effects and mechanisms by which MGF protects against FA-induced neurotoxicity. The results in murine hippocampal cells (HT22) revealed that co-treatment with MGF significantly decreased FA-induced cytotoxicity and inhibited Tau hyperphosphorylation in a dose-dependent manner. It was further found that these protective effects were achieved by attenuating FA-induced endoplasmic reticulum stress (ERS), as indicated by the inhibition of the ERS markers, GRP78 and CHOP, and downstream Tau-associated kinases (GSK-3β and CaMKII) expression. In addition, MGF markedly inhibited FA-induced oxidative damage, including Ca2+ overload, ROS generation, and mitochondrial dysfunction, all of which are associated with ERS. Further studies showed that the intragastric administration of 40 mg/kg/day MGF for 6 weeks significantly improved spatial learning ability and long-term memory in C57/BL6 mice with FA-induced cognitive impairment by reducing Tau hyperphosphorylation and the expression of GRP78, GSK-3β, and CaMKII in the brains. Taken together, these findings provide the first evidence that MGF exerts a significant neuroprotective effect against FA-induced damage and ameliorates mice cognitive impairment, the possible underlying mechanisms of which are expected to provide a novel basis for the treatment of AD and diseases caused by FA pollution.

[Display omitted] • A library of 13 5-bromo-substituted indirubins was designed and synthesized. • 5-Bromoindirubin-3'-glycerol-oxime ether (cmpd. 2) was revealed as hit compound. • Cmpd. 2 supressed inflammatory cytokine and prostaglandin release in monocytes. • Cmpd. 2 acts as cellular dual GSK-3β and CDK8/9 inhibitor. • Encapsulation of 2 into PLGA nanoparticles improves its pharmacological potential. Targeting protein kinases that regulate signalling pathways in inflammation is an effective pharmacological approach to alleviate uncontrolled inflammatory diseases. In this context, the natural product indirubin and its 6-bromo-substituted analogue 6-bromoindirubin-3 -glycerol-oxime ether (6BIGOE; 1) were identified as potent inhibitors of glycogen synthase kinase-3β (GSK-3β). These inhibitors suppress the release of pro-inflammatory cytokines and prostaglandins (PG) from human monocytes. However, indirubin derivatives target several protein kinases such as cyclin-dependent kinases (CDKs) which has been a major concern for their application in inflammation therapy. Here, we report on a library of 13 5-bromo-substituted indirubin derivatives that have been designed to improve potency and target selectivity. Side-by-side comparison of reference compound 1 (6BIGOE) with 5-bromo derivatives revealed its isomer 2 (5BIGOE), as the most potent derivative able to supress pro-inflammatory cytokine and PG release in lipopolysaccharide-stimulated human monocytes. Analysis of protein kinase inhibition in intact monocytes, supported by our in silico findings, proposed higher selectivity of 1 for GSK-3β inhibition with lesser potency against CDKs 8 and 9. In contrast, 2 supressed the activity of these CDKs with higher effectiveness than GSK-3β, representing additional targets of indirubins within the inflammatory response. Encapsulation of 1 and 2 into polymer-based nanoparticles (NP) improved their pharmacological potential. In conclusion, the 5- and 6-brominated indirubins 1 and 2 as dual GSK-3β and CDK8/9 inhibitors represent a novel concept for intervention with inflammatory disorders. [ABSTRACT FROM AUTHOR]

Increasing resistance of malarial parasites to current anti-malarials has led to efforts to explore use of medicinal plants as immunomodulators to target the host. Momordica charantia(MC) is an Asian dietary fruit with different pharmacological activities. GSK3 is known to be pivotal in the controlling of cytokine inflammatory response. Present investigation involves evaluation of MC aqueous extract for its anti-malarial activity and to elucidate whether its mechanism involves inhibition of GSK3β. Akt and NF-κB in the action of MC on GSK3 were evaluated. Our in vitro studies using Plasmodium falciparum 3D7 culture revealed that MC suppressed parasite growth with a selectivity index exceeding 10. Intra-peritoneal administration of the aqueous extract into P. berghei NK65-infected mice resulted in a dose-dependent manner and improved median survival time. The selected doses of MC into infected mice resulted in significant increase in the levels (7.2 and 2.7fold) of phosphorylated GSK3β and Akt respectively in liver. Decreased phosphorylation of NF-κB (2.0fold) in MC-treated infected mice was observed. MC decreased levels of the serum pro-inflammatory cytokines IFN-γ(2.7fold), TNF-α (4.9fold), while the anti-inflammatory cytokine level IL-10 was increased (2.3fold). Our findings demonstrate that anti-malarial effect of MC involved cytokine modulation mediated via inhibition of GSK3β in P. berghei- infected mice. [ABSTRACT FROM AUTHOR]

Zhenyang Zheng,1 Xiaolei Shi,2 Yue Xiang,3 Aiwu Zhang,2 Yannan Fang2 1Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, 350001, People’s Republic of China; 2Department of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510080, People’s Republic of China; 3Department of Nursing, Fujian Health College, Fuzhou, 350101, People’s Republic of ChinaCorrespondence: Yannan FangDepartment of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, People’s Republic of ChinaTel +86-20-87755766Fax +86-20-87335935Email fyn2012@126.comBackground: Recent studies indicated that analgesic overuse upregulated 5-hydroxytryptamine receptor 2A (5-HT2AR) and subsequently activated nitric oxide synthase (NOS) and thus induced latent sensitization, which provided a mechanistic basis for medication-overuse headache (MOH). Moreover, glycogen synthase kinase-3β (GSK-3β) was regulated by serotonin receptors and the phosphorylation of GSK-3β affected NOS activity, indicating that GSK-3β could be involved in the regulation of NOS activity by 5-HT2AR in MOH pathophysiology. Herein, we performed this study to investigate the role of 5-HT2AR in MOH pathophysiology and the role of GSK-3β in the regulation of NOS activity by 5-HT2AR.Materials and Methods: Wistar rats were daily administered with paracetamol (200 mg/kg) for 30 days to set animal models for pre-clinical MOH research. After the rat MOH models were successfully established, the expression of 5-HT2AR and NOS, GSK-3β activity in trigeminal nucleus caudalis (TNC) were assayed. Then, 5-HT2AR antagonist ketanserin and agonist DOI were applied to investigate the effect of 5-HT2AR on NOS activity in TNC of MOH rats, and GSK-3β antagonist LiCl and agonist perifosine were applied to explore the role of GSK-3β in the activation of NOS by 5-HT2AR.Results: We found that the expression of 5-HT2AR and NOS, GSK-3β activity were enhanced in TNC of MOH rats. 5-HT2AR modulator regulated the activity of NOS and GSK-3β in TNC of MOH rats, and drugs acting on GSK-3β affected NOS activity.Conclusion: These data suggest that GSK-3β may mediate the activation of NOS by 5-HT2AR and underline the role of 5-HT2AR in MOH pathophysiology.Keywords: medication-overuse headache, 5-hydroxytryptamine receptor 2A, nitric oxide synthase, glycogen synthase kinase-3β

Postmenopausal women with Alzheimer’s disease (AD) exhibit dramatically reduced sensitivity to estrogen replacement therapy, which is though to be related to an estrogen receptor (ER)α/ERβ ratio imbalance arising from a significantly decreased level of ERs of the brain. The aim of our study was to investigate whether valproic acid (VPA) can enhance the beneficial effects of estrogen on cognitive function through restoration of ERα and ERβ expression in the brain. We removed the ovaries of female APP/PS1 mice to simulate the low estrogen levels present in postmenopausal women and then administered VPA (30 mg/kg, intraperitoneal injection, once daily), 17β-estradiol (E2) (2.4 μg, intraperitoneal injection, once daily), liquiritigenin (LG) (50 μg/kg, intragastric infusion, once daily), VPA + E2, or VPA + LG for 4 successive weeks. Compared with treatment with a single drug, treatment with VPA + E2 or VPA + LG significantly increased the level of glycogen synthase kinase 3β, increased the expression of estrogen receptor α, reduced the expression of small ubiquitin-like modifiers, and increased the level of estrogen receptor β. This resulted in enhanced sensitivity to estrogen therapy, reduced amyloid β aggregation, reduced abnormal phosphorylation of the tau protein, reduced neuronal loss, increased dendritic spine and postsynaptic density, and significantly alleviated memory loss and learning impairment in mice. This study was approved by the Chongqing Medical University Animal Protection and Ethics Committee, China on March 6, 2013.

Summary: Background: Glycogen synthase kinase-3β (GSK-3β) is one of the most effective kinases in promoting tau hyperphosphorylation and accumulation in Alzheimer's disease (AD). However, it is not clear how GSK-3β activity is regulated during AD progression. Methods: We firstly used mass spectrometry to identify the acetylation site of GSK-3β, and then established the cell and animal models of GSK-3β acetylation. Next, we conducted molecular, cell biological and behavioral tests. Finally, we designed a peptide to test whether blocking tau-mediated GSK-3β acetylation could be beneficial to AD. Findings: We found that GSK-3β protein levels increased in the brains of AD patients and the transgenic mice. Overexpressing tau increased GSK-3β protein level with increased acetylation and decreased ubiquitination-related proteolysis. Tau could directly acetylate GSK-3β at K15 both in vitro and in vivo. K15-acetylation inhibited ubiquitination-associated proteolysis of GSK-3β and changed its activity-dependent phosphorylation, leading to over-activation of the kinase. GSK-3β activation by K15-acetylation in turn exacerbated the AD-like pathologies. Importantly, competitively inhibiting GSK-3β K15-acetylation by a novel-designed peptide remarkably improved cognitive impairment and the AD-like pathologies in 3xTg-AD mice. Interpretation: Tau can directly acetylate GSK-3β at K15 which reveals a vicious cycle between tau hyperphosphorylation and GSK-3β activation. Funding: This study was supported in parts by grants from Science and Technology Committee of China (2016YFC1305800), Hubei Province (2018ACA142), Natural Science Foundation of China (91949205, 82001134, 31730035, 81721005), Guangdong Provincial Key S&T Program (018B030336001).

Insulin regulates glucose metabolism via both direct hormone interactions with its signaling system and glucose transporters in cells of peripheral tissues and indirectly through the central nervous system. In type 2 diabetes mellitus (T2DM), impaired receptor-mediated transport across the blood–brain barrier leads to insulin deficiency in the brain and causes dysfunctions of eating behavior, thermogenesis, carbohydrate and lipid metabolism. Intranasal insulin (I-I) administration is used as an alternative way of its delivery to increase the hormone level in the brain. A combination of I-I administration with various insulin sensitizers facilitates the restoration of glucose tolerance in a shorter period of time at lower doses of insulin. Such a therapy, combining I-I administration (0.5 IU/rat/day) and intranasally administered total calf brain gangliosides (6 mg/kg/day), was applied here for the first time to treat T2DM rats. Intranasal co-administration of insulin and gangliosides led to the normalization of glucose tolerance in T2DM animals after 4 weeks of treatment, while taken separately, the drugs were less effective. As shown by Western blotting, the increase in hepatic insulin sensitivity may be due to a significant decrease in the expression of a negative insulin signaling regulator protein tyrosine phosphatase 1B (PTP1B) and an increase in the phosphorylation level of the key effector protein kinases Akt at Ser473, GSK3β at Ser9 and p38-MAPK at Thr180/Tyr182. Inhibitory phosphorylation of GSK3β at Ser9 may occur due to the activation of both Akt kinase and p38-MAPK, with the contribution of the latter being, in our opinion, more significant. Since intranasally administered insulin and gangliosides may directly affect brain regions responsible for the regulation of peripheral insulin sensitivity and hepatic carbohydrate metabolism, we concluded that the central mechanism of their action was predominant under conditions used in this study. [ABSTRACT FROM AUTHOR]

Ferroptosis is a form of regulated cell death resulting from iron accumulation and lipid peroxidation. Iron dyshomeostasis and peroxidation damage of neurons in some particular brain regions are closely related to a wide range of neurodegenerative diseases known as "tauopathies," in which intracellular aggregation of microtubule-associated protein tau is the common neuropathological feature. However, the relationship between ferroptosis and tau aggregation is not well understood. The current study demonstrates that erastin-induced ferroptosis can promote tau hyperphosphorylation and aggregation in mouse neuroblastoma cells (N2a cells). Moreover, ferroptosis inhibitor ferrostatin-1 can alleviate tau aggregation effectively. In-depth mechanism research indicates that activated glycogen synthase kinase-3β (GSK-3β) is responsible for the abnormal hyperphosphorylation of tau. More importantly, proteasome inhibition can exacerbate tau degradation obstacle and accelerate tau aggregation in the process of ferroptosis. Our results indicate that ferroptosis can lead to abnormal aggregation of tau protein and might be a promising therapeutic target of tauopathies. [ABSTRACT FROM AUTHOR]

Postoperative cognitive dysfunction is a common complication in elderly patients after surgeries involving anesthesia, but the underlying mechanisms are poorly understood. Lithium is a conventional treatment for bipolar disorder, which exerts a neuroprotective role in various diseases by inhibiting glycogen synthase kinase‐3β (GSK‐3β) in the brain and spinal cord. However, it is not known whether lithium chloride (LiCl) can protect against cognitive dysfunction induced by sevoflurane (SEV) anesthesia. Here, we examined the effects of LiCl on SEV‐induced cognitive dysfunction in rats and on SEV‐induced neuron apoptosis. We report that anesthesia with SEV significantly impaired memory performance, induced oxidative stress and hippocampal neuron apoptosis, and stimulated GSK‐3β activity. Treatment with LiCl ameliorated SEV‐induced cognitive disorder in rats by inhibiting the GSK‐3β/β‐catenin signaling pathway. In addition, LiCl reduced hippocampal neuron apoptosis and oxidative stress induced by SEV anesthesia. These results suggest that LiCl may have potential for development into a therapeutic agent for treatment of SEV anesthesia‐induced cognitive dysfunction.

Isoflurane and sevoflurane are both inhalation anesthetics, but in clinical application, sevoflurane has been considered to be less suitable for long-term anesthesia because of its catabolic compounds and potential nephrotoxicity. Nevertheless, recent studies have shown that these two inhalation anesthetics are similar in hepatorenal toxicity, cost, and long-term anesthetic effect. Moreover, sevoflurane possibly has less cognitive impact on young mice. In this study, C57BL/6 mice aged 8–10 weeks were exposed to 1.2% isoflurane or 2.4% sevoflurane for 6 hours. Cognitive function and memory were examined in young mice using the novel object recognition, contextual fear conditioning, and cued-fear extinction tests. Western blot assay was performed to detect expression levels of D1 dopamine receptor, catechol-O-methyltransferase, phospho-glycogen synthase kinase-3β, and total glycogen synthase kinase-3β in the hippocampus. Our results show that impaired performance was not detected in mice exposed to sevoflurane during the novel object recognition test. Contextual memory impairment in the fear conditioning test was shorter in the sevoflurane group than the isoflurane group. Long-term sevoflurane exposure did not affect memory consolidation, while isoflurane led to memory consolidation and reduced retention. Downregulation of hippocampal D1 dopamine receptors and phosphorylated glycogen synthase kinase-3β/total glycogen synthase kinase-3β and upregulation of catechol-O-methyltransferase may be associated with differing memory performance after exposure to isoflurane or sevoflurane. These results confirm that sevoflurane has less effect on cognitive impairment than isoflurane, which may be related to expression of D1 dopamine receptors and catechol-O-methyltransferase and phosphorylation of glycogen synthase kinase-3β in the hippocampus. This study was approved by the Institutional Animal Care and Use Committee, Nanjing University, China on November 20, 2017 (approval No. 20171102).

Glycogen synthase kinase-3 beta (GSK-3β) is a desired pharmacological target for cancer treatment. Despite its role in the development of various cancers, any target directing GSK-3 inhibitors have not been authorized for cancer treatment. The therapeutic importance of this enzyme is reflected in its monitoring character in autophagy, genetic material mismatch correction, tumor development, and invasion, which justifies medication combinations. GSK-3 controls various cell processes, including metabolism, signaling, and structural proteins. It modulates programmed cell death-ligand 1 (PD-L1) by phosphorylating target pro-oncogenes. New evidence on GSK-3 as a modulator of the antineoplastic immune response further highlights the potential uses of new GSK-3β selective antagonists currently being tested in humans. Indole, indazole, oxadiazole, isothiazolidinedione, and morpholine congeners are the privileged heterocyclic nucleus in drug discovery. These scaffolds produced numerous biological activities in which anticancer is important. The structure activity relationship studies may support to explore the design and synthesis of potential scaffolds in short time period. Therefore, in the present review, we tried to explore the structural aspects of GSK-3β with their structure–activity relationship against various targets for developing potential compounds. The GSK3β antagonists in clinical and preclinical trials have been reviewed in this study. And we tried to explore the structural aspects of several GSK-3β inhibitors with their structure–activity relationship for developing potential anticancer compounds, which will aid scientists in developing more target-specific therapeutic compounds with lower toxicity in the future.

In the pathogenesis of Alzheimer's disease, the overexpression of glycogen synthase kinase-3β (GSK-3β) stands out due to its multifaced nature, as it contributes to the promotion of amyloid β and tau protein accumulation, as well as neuroinflammatory processes. Therefore, in the present study, we have designed, synthesized, and evaluated a new series of GSK-3β inhibitors based on the N -(pyridin-2-yl)cyclopropanecarboxamide scaffold. We identified compound 36 , demonstrating an IC 50 of 70 nM against GSK-3β. Subsequently, through crystallography studies and quantum mechanical analysis, we elucidated its binding mode and identified the structural features crucial for interactions with the active site of GSK-3β, thereby understanding its inhibitory potency. Compound 36 was effective in the cellular model of hyperphosphorylated tau-induced neurodegeneration, where it restored cell viability after okadaic acid treatment and showed anti-inflammatory activity in the LPS model, significantly reducing NO, IL-6, and TNF-α release. In ADME-tox in vitro studies, we confirmed the beneficial profile of 36, including high permeability in PAMPA ( Pe equals 9.4) and high metabolic stability in HLMs as well as lack of significant interactions with isoforms of the CYP enzymes and lack of considerable cytotoxicity on selected cell lines (IC 50 > 100 μM on HT-22 cells and 89.3 μM on BV-2 cells). Based on promising pharmacological activities and favorable ADME-tox properties, compound 36 may be considered a promising candidate for in vivo research as well as constitute a reliable starting point for further studies.

Argemone mexicana L. is a medicinal plant, but its impact on Alzheimer's disease (AD) is right now undetermined. We intended to investigate the in-vitro anti-AD potential of leaves and flowers of A. mexicana methanol, ethanol, and ethyl extracts and to identify multi-modal anti-AD phytochemicals by computational approaches. Molecular docking of 196 phytochemicals identified three hit phytochemicals (protoberberine, protopine, and codeine) with higher binding affinity and multi-targeting ability toward AChE, BChE, BACE-1, and GSK-3β. Further MM-GBSA assays confirmed the integrity of these phytochemicals as the hit phytochemicals. However, these phytochemicals demonstrated favorable pharmacokinetics (PK) and drugable properties having no toxicity. Molecular dynamics simulations confirmed the binding strength of the hit phytoconstituents in the active pockets of AChE, BChE, BACE-1, and GSK-3β with multi-targeting inhibitory activities. All the extracts exhibited dose-dependent antioxidant and anti-cholinesterase activities supporting the in silico results in the context of oxidative stress and cholinergic pathways. Our results offer scientific validation of the anti-AD properties of Argemone mexicana L. and identified protoberberine, protopine, and codeine that could be used for the development of multi-modal inhibitors of AChE, BChE, BACE-1, and GSK-3β to combat AD. Additional in vivo validation is recommended to ensure a thorough assessment in the present research., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work presented in this paper., (© 2024 Published by Elsevier Ltd.)

The effect of taurine (Tau) on the inhibition of invasion and metastasis of colorectal cancer (CRC) was observed and the molecular mechanism of Tau inhibiting invasion and metastasis of CRC was explored. Human colorectal cancer SW480 and HT29 cells were selected as the research objects, and the cells were treated with Tau at a concentration of 40-200 mmoL. Transwell chamber and cell scar healing as-say were used to detect cell invasion and migration ability. Western blot was used to detect EMT signature proteins E-cadherin N-cadherin, Vimentin, matrix metalloproteinase 2/7 ( MMP2/7) and AKT/GSK-3β pathway related proteins. Compared with normal control group, Tau inhibited the invasion and migration of CRC in a concentration-dependent manner, up-regulated the expression of CRC epithelial marker E-cadher-in, and down-regulated the expression of EMT interstitial marker N-cadherin, Vimentin and MMPs. AKT and p-AKT levels were decreased, and PTEN, GSK-3β and p-GSK-3β expression levels were increased (P< 0.05). Compared with p-EGFP-GSK-3β or Tau group, the number of cell migration and invasion in p-EGFP-GSK-3β +Tau group was significantly decreased (P<0.01); Compared with Tau group or p-EGFP-GSK-3β group, the expression of E-cadherin GSK-3β protein in p-EGFP-GSK-3β+ Tau group was significantly increased (P<0.01), and the expression of N-cadherin,Vimentin,13-catenin MMP2,MMP7 and AKT was significantly decreased (P<0.01).Taurine can inhibit the invasion and metastasis of colorectal cancer cells by regulating the Akt/GSK-3β pathway. [ABSTRACT FROM AUTHOR]

Background: Propofol, an intravenous anesthetic, was proven to protect against lung ischemia/reperfusion (I/R) injury. However, the detailed mechanism of Propofol in lung I/R injury is still elusive. This study was designed to explore the therapeutic effects of Propofol, both in vivo and in vitro, on lung I/R injury and the underlying mechanisms related to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-144 (miR-144)/glycogen synthase kinase-3β (GSK3β). Methods: C57BL/6 mice were used to establish a lung I/R injury model while pulmonary microvascular endothelial cells (PMVECs) were constructed as hypoxia/reperfusion (H/R) cellular model, both of which were performed with Propofol treatment. Gain- or loss-of-function approaches were subsequently employed, followed by observation of cell apoptosis in lung tissues and evaluation of proliferative and apoptotic capabilities in H/R cells. Meanwhile, the inflammatory factors, autophagosomes, and autophagy-related proteins were measured. Results: Our experimental data revealed that Propofol treatment could decrease the elevated expression of MALAT1 following I/R injury or H/R induction, indicating its protection against lung I/R injury. Additionally, overexpressing MALAT1 or GSK3β promoted the activation of autophagosomes, proinflammatory factor release, and cell apoptosis, suggesting that overexpressing MALAT1 or GSK3β may reverse the protective effects of Propofol against lung I/R injury. MALAT1 was identified to negatively regulate miR-144 to upregulate the GSK3β expression. Conclusion: Overall, our study demonstrated that Propofol played a protective role in lung I/R injury by suppressing autophagy and decreasing release of inflammatory factors, with the possible involvement of the MALAT1/miR-144/GSK3β axis. [ABSTRACT FROM AUTHOR]

Metabolic syndrome (MetS) is largely coupled with chronic kidney disease (CKD). Glycogen synthase kinase-3β (GSK-3β) pathway drives tubular injury in animal models of acute kidney injury; but its contribution in CKD is still elusive. This study investigated the effect empagliflozin and/or pirfenidone against MetS-induced kidney dysfunction, and to clarify additional underpinning mechanisms particularly the GSK-3β signaling pathway. Adult male rats received 10% w / v fructose in drinking water for 20 weeks to develop MetS, then treated with either drug vehicle, empagliflozin (30 mg/kg/day) and/or pirfenidone (100 mg/kg/day) via oral gavage for subsequent 4 weeks, concurrently with the high dietary fructose. Age-matched rats receiving normal drinking water were used as controls. After 24 weeks, blood and kidneys were harvested for subsequent analyses. Rats with MetS showed signs of kidney dysfunction, structural changes and interstitial fibrosis. Activation of GSK-3β, decreased cyclinD1 expression and enhanced apoptotic signaling were found in kidneys of MetS rats. There was abundant alpha-smooth muscle actin (α-SMA) expression along with up-regulation of TGF-β1/Smad3 in kidneys of MetS rats. These derangements were almost alleviated by empagliflozin or pirfenidone, with evidence that the combined therapy was more effective than either individual drug. This study emphasizes a novel mechanism underpinning the beneficial effects of empagliflozin and pirfenidone on kidney dysfunction associated with MetS through targeting GSK-3β signaling which can mediate the regenerative capacity, anti-apoptotic effects and anti-fibrotic properties of such drugs. These findings recommend the possibility of using empagliflozin and pirfenidone as promising therapies for management of CKD in patients with MetS. [Display omitted] • Empagliflozin mitigates renal dysfunction in rats with metabolic syndrome (MetS). • Empagliflozin suppresses the activation of GSK-3β signaling in kidneys of MetS rats. • Empagliflozin exerts anti-apoptotic and antifibrotic effect in kidneys of MetS rats. • Empagliflozin promotes regenerative potential of renal tubular cells in MetS rats. • Pirfenidone enhances the renoprotective effect of empagliflozin. [ABSTRACT FROM AUTHOR]

A new series of fifteen 5-, 6-, and 8-appended 4-methylquinolines were synthesized and evaluated for their neural protective activities. Selected compounds were further examined for their inhibition of glycogen synthase kinase-3β (GSK-3β) and protein kinase C (PKC). Two most potent analogs, compounds 3 and 10, show nanomolar protective activities in amyloid β-induced MC65 cells and enzymatic inhibitory activities against GSK-3β, but poor PKC inhibitory activities. Using normal mouse model, the distribution of the most potent analog 3 in various tissues and possible toxic effects in the locomotors and inhibition of liver transaminases activities were carried out. No apparent decline of locomotor activity and no inhibition of liver transaminases were found. The compound appears to be safe for long-term use in Alzheimer's disease mouse model.

Rehabilitation training is believed to be beneficial to patients with stroke, but its molecular mechanism is still unclear. Rat models of cerebral ischemic stroke were established by middle cerebral artery occlusion/reperfusion, and then received treadmill training of different intensities, twice a day for 30 minutes for 1 week. Low-intensity training was conducted at 5 m/min, with a 10-minute running, 10-minute rest, and 10-minute running cycle. In the moderate-intensity training, the intensity gradually increased from 5 m/min to 10 m/min in 5 minutes, with the same rest cycle as above. In high-intensity training, the intensity gradually increased from 5 m/min to 25 m/min in 5 minutes, with the same rest cycle as above. The Bederson scale was used to evaluate the improvement of motor function. Infarct volume was detected using 2,3,5-triphenyltetrazolium chloride staining. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining was applied to detect the apoptosis of nerve cells in brain tissue. Western blot assay was employed to analyze the activation of cyclic adenosine monophosphate (cAMP)/protein kinase A and Akt/glycogen synthase kinase-3β signaling pathways in rat brain tissue. All training intensities reduced the neurological deficit score, infarct volume, and apoptosis in nerve cells in brain tissue of stroke rats. Training intensities activated the cAMP/protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This activation was more obvious with higher training intensities. These changes were reversed by intracerebroventricular injection of protein kinase A inhibitor Rp-cAMP. Our findings indicate that the neuroprotective effect of rehabilitation training is achieved via activation of the cAMP/protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This study was approved by the Ethics Committee of Animal Experimentation in Shanghai No. 8 People’s Hospital, China.

In Alzheimer's disease (AD), the enzyme acetylcholinesterase (AChE) co‐localizes with hyperphosphorylated tau (P‐tau) within neurofibrillary tangles. Having demonstrated that AChE expression is increased in the transgenic mouse model of tau Tg‐VLW, here we examined whether modulating phosphorylated tau levels by over‐expressing wild‐type human tau and glycogen synthase kinase‐3β (GSK3β) influences AChE expression. In SH‐SY5Y neuroblastoma cells expressing higher levels of P‐tau, AChE activity and protein increased by (20% ± 2%) and (440% ± 150%), respectively. Western blots and qPCR assays showed that this increment mostly corresponded to the cholinergic ACHE‐T variant, for which the protein and transcript levels increased ~60% and ~23%, respectively. Moreover, in SH‐SY5Y cells differentiated into neurons by exposure to retinoic acid (10 µM), over‐expression of GSK3β and tau provokes an imbalance in cholinergic activity with a decrease in the neurotransmitter acetylcholine in the cell (45 ± 10%). Finally, we obtained cerebrospinal fluid (CSF) from AD patients enrolled on a clinical trial of tideglusib, an irreversible GSK3β inhibitor. In CSF of patients that received a placebo, there was an increase in AChE activity (35 ± 16%) respect to basal levels, probably because of their treatment with AChE inhibitors. However, this increase was not observed in tideglusib‐treated patients. Moreover, CSF levels of P‐tau at the beginning measured by commercially ELISA kits correlated with AChE activity. In conclusion, this study shows that P‐tau can modulate AChE expression and it suggests that AChE may possibly increase in the initial phases of AD. [ABSTRACT FROM AUTHOR]

• Sevoflurane activates Cdk5/CRMP2 or GSK-3β/CRMP2 pathway in neonatal rat brain. • Cdk5/GSK-3β blocker rescues sevoflurane-induced synaptic and cognitive impairment. • Inhibition of CRMP2 eliminates the protective effects of Cdk5 or GSK-3β blocker. General anesthetics such as sevoflurane interfere with dendritic development and synaptogenesis, resulting in cognitive impairment. The collapsin response mediator protein2 (CRMP2) plays important roles in dendritic development and synaptic plasticity and its phosphorylation is regulated by cycline dependent kinase-5 (Cdk5) and glycogen synthase kinase-3β (GSK-3β). Here we investigated whether Cdk5/CRMP2 or GSK-3β/CRMP2 pathway is involved in sevoflurane-induced developmental neurotoxicity. Rats at postnatal day 7 (PND7) were i.p. injected with Cdk5 inhibitor roscovitine, GSK-3β inhibitor SB415286 or saline 20 min. before exposure to 2.8% sevoflurane for 4 h. Western-blotting was applied to measure the expression of Cdk5/CRMP2 and GSK-3β/CRMP2 pathway proteins in the hippocampus 6 h after the sevoflurane exposure. When rats grew to adolescence (from PND25), they were tested for open-field and contextual fear conditioning, and then long term potentiation (LTP) from hippocampal slices was recorded, and morphology of pyramidal neuron was examined by Golgi staining and synaptic plasticity-related proteins expression in hippocampus were measured by western-blotting. In another batch of experiment, siRNA-CRMP2 or vehicle control was injected into hippocampus on PND5. Sevoflurane activated Cdk5/CRMP2 and GSK-3β/CRMP2 pathways in the hippocampus of neonatal rats, reduced dendritic length, branches and the density of dendritic spine in pyramidal neurons. It also reduced the expressions of PSD-95, drebrin and synaptophysin in hippocampus, impaired memory ability of rats and inhibited LTP in hippocampal slices. All the impairment effects by sevoflurane were attenuated by pretreatment with inhibitor of Cdk5 or GSK-3β. Furthermore, rat transfected with siRNA-CRMP2 eliminated the neuroprotective effects of Cdk5 or GSK-3β blocker in neurobehavioral and LTP tests. Cdk5/CRMP2 and GSK-3β/CRMP2 pathways participate in sevoflurane-induced dendritic development abnormalities and cognitive dysfunction in developing rats. [ABSTRACT FROM AUTHOR]