Inhibition Of Glycogen Synthase Kinase-3β Research Articles

Capturing the Effects of Single Atom Substitutions on the Inhibition Efficiency of Glycogen Synthase Kinase-3β Inhibitors via Markov State Modeling and Experiments.

Small modifications in the chemical structure of ligands are known to dramatically change their ability to inhibit the activity of a protein. Unraveling the mechanisms that govern these dramatic changes requires scrutinizing the dynamics of protein-ligand binding and unbinding at the atomic level. As an exemplary case, we have studied Glycogen Synthase Kinase-3β (GSK-3β), a multifunctional kinase that has been implicated in a host of pathological processes. As such, there is a keen interest in identifying ligands that inhibit GSK-3β activity. One family of compounds that are highly selective and potent inhibitors of GSK-3β is exemplified by a molecule termed COB-187. COB-187 consists of a five-member heterocyclic ring with a thione at C2, a pyridine substituted methyl at N3, and a hydroxyl and phenyl at C4. We have studied the inhibition of GSK-3β by COB-187-related ligands that differ in a single heavy atom from each other (either in the location of nitrogen in their pyridine ring, or with the pyridine ring replaced by a phenyl ring), or in the length of the alkyl group joining the pyridine and the N3. The inhibition experiments show a large range of half-maximal inhibitory concentration (IC50) values from 10 nM to 10 μM, implying that these ligands exhibit vastly different propensities to inhibit GSK-3β. To explain these differences, we perform Markov State Modeling (MSM) using fully atomistic simulations. Our MSM results are in excellent agreement with the experiments in that they accurately capture differences in the binding propensities of the ligands. The simulations show that the binding propensities are related to the ligands' ability to attain a compact conformation where their two aromatic rings are spatially close. We rationalize this result by sampling numerous binding and unbinding events via funnel metadynamics simulations, which show that indeed while approaching the bound state, the ligands prefer to be in their compact conformation. We find that the presence of nitrogen in the aromatic ring increases the probability of attaining the compact conformation. Protein-ligand binding is understood to be dictated by the energetics of interactions and entropic factors, like the release of bound water from the binding pockets. This work shows that changes in the conformational distribution of ligands due to atom-level modifications in the structure play an important role in protein-ligand binding.

Anti-oxidative stress and cognitive improvement of a semi-synthetic isoorientin-based GSK-3β inhibitor in rat pheochromocytoma cell PC12 and scopolamine-induced AD model mice via AKT/GSK-3β/Nrf2 pathway

BackgroundAlzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive deficits. Although the pathogenesis of AD is unclear, oxidative stress has been implicated to play a dominant role in its development. The flavonoid isoorientin (ISO) and its synthetic derivatives TFGF-18 selectively inhibit glycogen synthase kinase-3β (GSK-3β), a potential target of AD treatment. PurposeTo investigate the neuroprotective effect of TFGF-18 against oxidative stress via the GSK-3β pathway in hydrogen peroxide (H2O2)-induced rat pheochromocytoma PC12 cells in vitro and scopolamine (SCOP)-induced AD mice in vivo. MethodThe oxidative stress of PC12 cells was induced by H2O2 (600 μM) and the effects of TFGF-18 (2 and 8 μM) or ISO (12.5 and 50 μM) were observed. The AD mouse model was induced by SCOP (3 mg/kg), and the effects of TFGF-18 (2 and 8 mg/kg), ISO (50 mg/kg), and donepezil (DNP) (3 mg/kg) were observed. DNP, a currently accepted drug for AD was used as a positive control. The neuronal cell damages were analyzed by flow cytometry, LDH assay, JC-1 assay and Nissl staining. The oxidative stress was evaluated by the detection of MDA, SOD, GPx and ROS. The level of ACh, and the activity of AChE, ChAT were detected by the assay kit. The expressions of Bax, Bcl-2, caspase3, cleaved-caspase3, p-AKT (Thr308), AKT, p-GSK-3β (Ser9), GSK-3β, Nrf2, and HO-1, as well as p-CREB (Ser133), CREB, and BDNF were analyzed by western blotting. Morris water maze test was performed to analyze learning and memory ability. ResultsTFGF-18 inhibited neuronal damage and the expressions of Bax, caspase3 and cleaved-caspase3, and increased the expression of Bcl-2 in vitro and in vivo. The level of MDA and ROS were decreased while the activities of SOD and GPx were increased by TFGF-18. Moreover, TFGF-18 increased the p-AKT, p-GSK-3β (Ser9), Nrf2, HO-1, p-CREB, and BDNF expression reduced by H2O2 and SCOP. Meanwhile, MK2206, an AKT inhibitor, reversed the effect of TFGF-18 on the AKT/GSK-3β pathway. In addition, the cholinergic system (ACh, ChAT, and AChE) disorders were retrained and the learning and memory impairments were prevented by TFGF-18 in SCOP-induced AD mice. ConclusionsTFGF-18 protects against neuronal cell damage and cognitive impairment by inhibiting oxidative stress via AKT/GSK-3β/Nrf2 pathway.

Apigenin alleviates doxorubicin-induced myocardial pyroptosis by inhibiting glycogen synthase kinase-3β in vitro and in vivo.

Apigenin, a natural flavonoid compound found in chamomile (Matricaia chamomilla L.) from the Asteraceae family, has been shown in our previous study to possess antimyocardial hypertrophy and anti-cardiac fibrosis effects. However, its effects and mechanisms on the pyroptosis of cardiomyocytes induced by doxorubicin (DOX) are poorly understood. The objective of this study was to investigate the role of GSK-3β and the effects of apigenin in DOX-induced cardiotoxicity. H9c2 cells stimulated with DOX were treated with SB216763 and apigenin. Additionally, a mouse model of DOX-induced cardiotoxicity was prepared and further treated with apigenin and SB216763 for 30 days. The findings revealed that treatment with SB216763 or apigenin resulted in a significant reduction in the levels of pyroptosis-related factors. Furthermore, the phosphorylation of GSK-3β was enhanced while the phosphorylation of nuclear factor-kB (NF-κB) p65 was reduced following treatment with either SB216763 or apigenin. Conversely, the effects of apigenin treatment were nullified in siRNA-GSK-3β-transfected cells. Results from computer simulation and molecular docking analysis supported that apigenin could directly target the regulation of GSK-3β. Therefore, our study confirmed that the inhibition of GSK-3β and treatment with apigenin effectively suppressed the pyroptosis of cardiomyocytes in both DOX-stimulated H9c2 cells and mice. These benefits may be attributed in part to the decrease in GSK-3β expression and subsequent reduction in NF-κB p65 activation. Overall, our findings revealed that the pharmacological targeting of GSK-3β may offer a promising therapeutic approach for alleviating DOX-induced cardiotoxicity.

Combined in vivo effect of N-acylethanolamine-hydrolyzing acid amidase and glycogen synthase kinase-3β inhibition to treat multiple sclerosis

The current pharmacological approaches to multiple sclerosis (MS) target its inflammatory and autoimmune components, but effective treatments to foster remyelination and axonal repair are still lacking. We therefore selected two targets known to be involved in MS pathogenesis: N-acylethanolamine-hydrolyzing acid amidase (NAAA) and glycogen synthase kinase-3β (GSK-3β). We tested whether inhibiting these targets exerted a therapeutic effect against experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The combined inhibition of NAAA and GSK-3β by two selected small-molecule compounds, ARN16186 (an NAAA inhibitor) and AF3581 (a GSK-3β inhibitor), effectively mitigated disease progression, rescuing the animals from paralysis and preventing a worsening of the pathology. The complementary activity of the two inhibitors reduced the infiltration of immune cells into the spinal cord and led to the formation of thin myelin sheaths around the axons post-demyelination. Specifically, the inhibition of NAAA and GSK-3β modulated the over-activation of NF-kB and STAT3 transcription factors in the EAE-affected mice and induced the nuclear translocation of β-catenin, reducing the inflammatory insult and promoting the remyelination process. Overall, this work demonstrates that the dual-targeting of key aspects responsible for MS progression could be an innovative pharmacological approach to tackle the pathology.

Synthesis and Evaluation of 5-(Heteroarylmethylene)hydantoins as Glycogen Synthase Kinase-3β Inhibitors.

Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase which plays a center role in the phosphorylation of a wide variety of proteins, generally leading to their inactivation. As such, GSK-3 is viewed as a therapeutic target. An ever-increasing number of small organic molecule inhibitors of GSK-3 have been reported. Phenylmethylene hydantoins are known to exhibit a wide range of inhibitory activities including for GSK-3β. A family of fourteen 2-heterocycle substituted methylene hydantoins (14, 17-29) were prepared and evaluated for the inhibition of GSK-3β at 25 μM. The IC50 values of five of these compounds was determined; the two best inhibitors are 5-[(4'-chloro-2-pyridinyl)methylene]hydantoin (IC50 = 2.14 ± 0.18 μM) and 5-[(6'-bromo-2-pyridinyl)methylene]hydantoin (IC50 = 3.39 ± 0.16 μM). The computational docking of the compounds with GSK-3β (pdb 1q41) revealed poses with hydrogen bonding to the backbone at Val135. The 5-[(heteroaryl)methylene]hydantoins did not strongly inhibit other metalloenzymes, demonstrating poor inhibitory activity against matrix metalloproteinase-12 at 25 μM and against human carbonic anhydrase at 200 μM, and were not inhibitors for Staphylococcus aureus pyruvate carboxylase at concentrations >1000 μM.

Mature neurons from iPSCs unveil neurodegeneration-related pathways in mucopolysaccharidosis type II: GSK-3β inhibition for therapeutic potential

Mucopolysaccharidosis (MPS) type II is caused by a deficiency of iduronate-2-sulfatase and is characterized by the accumulation of glycosaminoglycans (GAGs). Without effective therapy, the severe form of MPS II causes progressive neurodegeneration and death. This study generated multiple clones of induced pluripotent stem cells (iPSCs) and their isogenic controls (ISO) from four patients with MPS II neurodegeneration. MPS II-iPSCs were successfully differentiated into cortical neurons with characteristic biochemical and cellular phenotypes, including axonal beadings positive for phosphorylated tau, and unique electrophysiological abnormalities, which were mostly rescued in ISO-iPSC-derived neurons. RNA sequencing analysis uncovered dysregulation in three major signaling pathways, including Wnt/β-catenin, p38 MAP kinase, and calcium pathways, in mature MPS II neurons. Further mechanistic characterization indicated that the dysregulation in calcium signaling led to an elevated intracellular calcium level, which might be linked to compromised survival of neurons. Based on these dysregulated pathways, several related chemicals and drugs were tested using this mature MPS II neuron-based platform and a small-molecule glycogen synthase kinase-3β inhibitor was found to significantly rescue neuronal survival, neurite morphology, and electrophysiological abnormalities in MPS II neurons. Our results underscore that the MPS II-iPSC-based platform significantly contributes to unraveling the mechanisms underlying the degeneration and death of MPS II neurons and assessing potential drug candidates. Furthermore, the study revealed that targeting the specific dysregulation of signaling pathways downstream of GAG accumulation in MPS II neurons with a well-characterized drug could potentially ameliorate neuronal degeneration.

Glycogen Synthase Kinase-3β Inhibitor VP3.15 Ameliorates Neurogenesis, Neuronal Loss and Cognitive Impairment in a Model of Germinal Matrix-intraventricular Hemorrhage of the Preterm Newborn.

Advances in neonatology have significantly reduced mortality rates due to prematurity. However, complications of prematurity have barely changed in recent decades. Germinal matrix-intraventricular hemorrhage (GM-IVH) is one of the most severe complications of prematurity, and these children are prone to suffer short- and long-term sequelae, including cerebral palsy, cognitive and motor impairments, or neuropsychiatric disorders. Nevertheless, GM-IVH has no successful treatment. VP3.15 is a small, heterocyclic molecule of the 5-imino-1,2,4-thiadiazole family with a dual action as a phosphodiesterase 7 and glycogen synthase kinase-3β (GSK-3β) inhibitor. VP3.15 reduces neuroinflammation and neuronal loss in other neurodegenerative disorders and might ameliorate complications associated with GM-IVH. We administered VP3.15 to a mouse model of GM-IVH. VP3.15 reduces the presence of hemorrhages and microglia in the short (P14) and long (P110) term. It ameliorates brain atrophy and ventricle enlargement while limiting tau hyperphosphorylation and neuronal and myelin basic protein loss. VP3.15 also improves proliferation and neurogenesis as well as cognition after the insult. Interestingly, plasma gelsolin levels, a feasible biomarker of brain damage, improved after VP3.15 treatment. Altogether, our data support the beneficial effects of VP3.15 in GM-IVH by ameliorating brain neuroinflammatory, vascular and white matter damage, ultimately improving cognitive impairment associated with GM-IVH.

Efficient synthesis of 1-azakenpaullone, a selective inhibitor of glycogen synthase kinase-3β for cellular regeneration

The selective GSK-3β inhibitor 1-azakenpaullone has broad applications in cellular regeneration and regenerative medicine. A two-step protocol featuring an indium-trichloride-mediated intramolecular cyclization to 1-azakenpaullone is disclosed.

A Complex Interplay between Notch Effectors and β-Catenin Signaling in Morular Differentiation of Endometrial Carcinoma Cells

Notch signaling contributes to tissue development and homeostasis, but little is known about its roles in morular differentiation of endometrial carcinoma (Em Ca) cells. The current study focused on crosstalk between Notch and β-catenin signaling in Em Ca with morules. Promoters of hairy and enhancer of split 1 (Hes1) and mastermind-like 2 (MAML2) were activated by Notch intracellular domain 1 (NICD1) but not β-catenin; we also observed a positive feedback loop between Hes1 and MAML2. Immunoreactivities for nuclear β-catenin, Hes1, and MAML2, as well as the interaction between β-catenin and Hes1 or MAML2, were significantly higher in morular lesions as compared to surrounding carcinoma (Sur Ca) in Em Ca. Inhibition of glycogen synthase kinase-3β (GSK-3β) increased expression of total nuclear and cytoplasmic GSK-3β and its phosphorylated forms, as well as NICD1, Hes1, and active β-catenin. GSK-3β inhibition also decreased proliferation and migration, consistent with the response of cells stably overexpressing Hes1. Finally, the nuclear/cytoplasmic GSK-3β score was significantly higher in morules compared to Sur Ca in Em Ca, and was positively correlated with nuclear β-catenin, Hes1, and MAML2 scores. This complex interplay between Notch effectors and β-catenin signaling through GSK-3β inhibition contributes to the establishment and maintenance of β-catenin-mediated morular differentiation, which is in turn associated with reduced proliferation and inhibition of migration in Em Ca.

Massive expansion of functional human iPSC-derived cardiomyocytes by concomitant glycogen synthase kinase-3 beta inhibition and removal of cell-cell contact

Abstract Background Adult mammalian heart has limited capacity for regeneration. Cardiac injuries such as myocardial infarction lead to significant cardiomyocyte (CM) loss and subsequent heart failure with significant morbidity and mortality. Cell-based therapeutic approaches such as injection of stem cell-derived cells or transplantation of engineered cardiac tissue patches have shown promise to re-muscularize the damaged myocardium and enhance cardiac functions. Rationale: Modulating signaling pathways including Wnt and Hippo can induce cardiomyocyte proliferation in vivo. Applying these signaling modulators to human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in vitro can expand CMs modestly (< 5-fold). Results Here, we demonstrate massive expansion of hiPSC-CMs in vitro (i.e. 100 to 250-fold) by glycogen synthase kinase-3β (GSK-3β) inhibition using CHIR99021 and concurrent removal of cell-cell contact. We show GSK-3β inhibition suppresses CM maturation while contact removal prevents CMs from cell cycle exit. Remarkably, contact removal enabled 10- to 25-times greater expansion beyond GSK-3β inhibition alone. Mechanistically, persistent CM proliferation required both LEF/TCF activity and AKT phosphorylation but was independent from Yes associated protein (YAP) signaling. Engineered heart tissues from expanded hiPSC-CMs showed comparable contractility to those from unexpanded hiPSC-CMs, demonstrating uncompromised cellular functionality after expansion. Conclusion In summary, we uncovered a molecular interplay that enables massive hiPSC-CMs expansion for large-scale drug screening and tissue engineering applications.

Effects of combined exposure to ethanol and delta-9-tetrahydrocannabinol during adolescence on synaptic plasticity in the prefrontal cortex of Long Evans rats

Significant exposure to alcohol or cannabis during adolescence can induce lasting disruptions of neuronal signaling in brain regions that are later to mature, such as the medial prefrontal cortex (mPFC). Considerably less is known about the effects of alcohol and cannabis co-use, despite its common occurrence. Here, we used male and female Long-Evans rats to investigate the effects of early-life exposure to ethanol, delta-9-tetrahydrocannabinol (THC), or their combination on high frequency stimulation (HFS)-induced plasticity in the prelimbic region of the mPFC. Animals were injected daily from postnatal days 30–45 with vehicle or THC (escalating doses, 3–20 mg/kg) and allowed to drink vehicle (0.1% saccharin) or 10% ethanol immediately after each injection. In vitro brain slice electrophysiology was then used to record population responses of layer V neurons following HFS in layer II/III after 3–4 weeks of abstinence. We found that THC exposure reduced body weight gains observed in ad libitum fed rats, and reduced intake of saccharin and ethanol. Compared to controls, there was a significant reduction in HFS-induced long-term depression (LTD) in rats exposed to either drug alone, and an absence of LTD in rats exposed to the drug combination. Bath application of indiplon or AR-A014418, which enhance GABAA receptor function or inhibit glycogen synthase kinase 3β (GSK3β), respectively, suggested the effects of ethanol, THC or their combination were due in part to lasting adaptations in GABA and GSK3β signaling. These results suggest the potential for long-lasting adaptations in mPFC output following co-exposure to alcohol and THC.

CHIR99021 causes inactivation of Tyrosine Hydroxylase and depletion of dopamine in rat brain striatum

CHIR99021, also known as laduviglusib or CT99021, is a Glycogen-synthase kinase 3β (GSK3β) inhibitor, which has been reported as a promising drug for cardiomyocyte regeneration or treatment of sensorial hearing loss. Since the activation of dopamine (DA) receptors regulates dopamine synthesis and they can signal through the β-arrestin pathway and GSK3β, we decided to check the effect of GSK3β inhibitors (CHIR99021, SB216763 and lithium ion) on the control of DA synthesis. Using ex vivo experiments with minces from rat brain striatum, we observed that CHIR99021, but not SB216763 or lithium, causes complete abrogation of both DA synthesis and accumulation, pointing to off-target effects of CHIR99021. This decrease can be attributed to tyrosine hydroxylase (TH) inhibition since the accumulation of l-DOPA in the presence of a DOPA decarboxylase inhibitor was similarly decreased. On the other hand, CHIR99021 caused a dramatic increase in the DOPAC/DA ratio, an indicator of DA metabolization, and hindered DA incorporation into striatum tissue. Tetrabenazine, an inhibitor of DA vesicular transport, also caused DA depletion and DOPAC/DA ratio increase to the same extent as CHIR99021. In addition, both CHIR99021 or SB216763, but not lithium, decreased TH phosphorylation in Ser19, but not in Ser31 or Ser40. These results demonstrate that CHIR99021 can lead to TH inactivation and DA depletion in brain striatum, opening the possibility of its use in DA-related disorders, and shows effects to be considered in future clinical trials. More work is needed to find the mechanism exerted by CHIR99021 on DA accumulation.

E-cadherin/β-catenin expression is conserved in human and rat erythropoiesis and marks stress erythropoiesis

AbstractE-cadherin is a crucial regulator of epithelial cell-to-cell adhesion and an established tumor suppressor. Aside epithelia, E-cadherin expression marks the erythroid cell lineage during human but not mouse hematopoiesis. However, the role of E-cadherin in human erythropoiesis remains unknown. Because rat erythropoiesis was postulated to reflect human erythropoiesis more closely than mouse erythropoiesis, we investigated E-cadherin expression in rat erythroid progenitors. E-cadherin expression is conserved within the erythroid lineage between rat and human. In response to anemia, erythroblasts in rat bone marrow (BM) upregulate E-cadherin as well as its binding partner β-catenin. CRISPR/Cas9–mediated knock out of E-cadherin revealed that E-cadherin expression is required to stabilize β-catenin in human and rat erythroblasts. Suppression of β-catenin degradation by glycogen synthase kinase 3β (GSK3β) inhibitor CHIR99021 also enhances β-catenin stability in human erythroblasts but hampers erythroblast differentiation and survival. In contrast, direct activation of β-catenin signaling, using an inducible, stable β-catenin variant, does not perturb maturation or survival of human erythroblasts but rather enhances their differentiation. Although human erythroblasts do not respond to Wnt ligands and direct GSK3β inhibition even reduces their survival, we postulate that β-catenin stability and signaling is mostly controlled by E-cadherin in human and rat erythroblasts. In response to anemia, E-cadherin–driven upregulation and subsequent activation of β-catenin signaling may stimulate erythroblast differentiation to support stress erythropoiesis in the BM. Overall, we uncover E-cadherin/β-catenin expression to mark stress erythropoiesis in rat BM. This may provide further understanding of the underlying molecular regulation of stress erythropoiesis in the BM, which is currently poorly understood.

MicroRNAs as Potential Regulators of GSK-3β in Renal Cell Carcinoma.

The prognosis of patients with advanced renal cell carcinoma (RCC) has improved with newer therapies, including molecular-targeted therapies and immuno-oncology agents. Despite these therapeutic advances, many patients with metastatic disease remain uncured. Inhibition of glycogen synthase kinase-3β (GSK-3β) is a promising new therapeutic strategy for RCC; however, the precise regulatory mechanism has not yet been fully elucidated. MicroRNAs (miRNAs) act as post-translational regulators of target genes, and we investigated the potential regulation of miRNAs on GSK-3β in RCC. We selected nine candidate miRNAs from three databases that could potentially regulate GSK-3β. Among these, hsa-miR-4465 (miR-4465) was downregulated in RCC cell lines and renal cancer tissues. Furthermore, luciferase assays revealed that miR-4465 directly interacted with the 3' untranslated region of GSK-3β, and Western blot analysis showed that overexpression of miR-4465 significantly decreased GSK-3β protein expression. Functional assays showed that miR-4465 overexpression significantly suppressed cell invasion of A498 and Caki-1 cells; however, cell proliferation and migration were suppressed only in Caki-1 and A498 cells, respectively, with no effect on cell cycle and apoptosis. In conclusion, miR-4465 regulates GSK-3β expression but does not consistently affect RCC cell function as a single molecule. Further comprehensive investigation of regulatory networks is required in this field.

Novel synergistic treatment for depression: involvement of GSK3β-regulated AMPA receptors in the prefrontal cortex of mice.

Previous evidence has suggested a vital role of glycogen synthase kinase 3β-mediated α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors trafficking in depression. Considering the antidepressant effect of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors activation in the prefrontal cortex, we hypothesized that glycogen synthase kinase 3β-induced alterations in α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors function in the prefrontal cortex participate in depression. Herein, we confirmed that the levels of phosphorylated glycogen synthase kinase 3β and GluA1, the latter being a subunit of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors, were decreased in the prefrontal cortex of the chronic social defeat stress model mice presenting with depressive-like behaviors. We then found that a glycogen synthase kinase 3β (p.S9A) point mutation downregulated GluA1 and induced depressive-like behaviors in mice, whereas an agonist of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors, PF-4778574 (2mg/kg) did not reversed the molecular changes. On the other hand, the antidepressant effect of PF-4778574 was dose dependent, and the single administration of PF-4778574 at a lower dose (0.5mg/kg) or of the glycogen synthase kinase 3β inhibitor SB216763 (5 and 10mg/kg) did not evoke an antidepressant effect. In contrast, co-treatment with PF-4778574 (0.5mg/kg) and SB216763 (10mg/kg) led to antidepressant effects similar to those of PF-4778574 (2mg/kg). Our results suggest that glycogen synthase kinase 3β-induced α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors dysfunction in the prefrontal cortex is one of the key mechanisms of depression, and the combination of a lower dose of PF-4778574 with SB216763 shows potential as a novel synergistic treatment for depression.

Computational Simulations Reveal the Synergistic Action of Phytochemicals of Morus alba to Exert Anti-Alzheimer Activity via Inhibition of Acetylcholinesterase and Glycogen Synthase Kinase-3β

Morus alba Linn. is a popular medium-sized tree with a potent neuroprotective activity such as anti-Alzheimer. To date, it is not known which phytocompound of M. alba exerts anti-Alzheimer activity. Therefore, the present study was aimed to identify the phytochemicals of M. alba responsible for the anti-Alzheimer activity by targeting proteins such as acetylcholinesterase (AChE) and glycogen synthase kinase-3 beta (GSK-3β) that are associated in the pathogenesis of Alzheimer disease (AD). Molecular docking, molecular dynamics (MD) simulations and MM-GBSA calculations were performed for the study. Phytocompounds with code 32, 41, 67, and 70 showed the best glide gscore against AchE and GSK-3β. All these phytocompounds interacted with multiple crucial amino acids present at the active binding site of the proteins through conventional hydrogen bonds and hydrophobic interactions. MD simulations of 100 ns revealed stable conformation for all protein-ligand complexes. Based on the computational findings, we conclude that M. alba’s phytoconstituents (32, 41 67, and 70) exerts anti-Alzheimer potential by inhibiting AChE and GSK-3β.

GSK3β Inhibition Ameliorates Atherosclerotic Calcification.

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.

Mango ginger (Curcuma amada Roxb.) may alleviate the effect of high-fat diet/streptozotocin-induced diabetes by activation of the GSK-3β/Fyn/Nrf2 pathway.

Mango ginger (MG) exhibits antioxidant, anti-inflammatory, and antihyperglycemic effects; however, the exact mechanism of action of MG extract in relation to its antidiabetic properties remains unclear. To investigate the potential antidiabetic effect of MG extract, we used a high-fat diet (HFD)/low-dose streptozotocin (STZ)-induced type 2 diabetic rat model. A total of 28 male Wistar rats were randomly divided into four groups: (i) Control, (ii) MG (50 mg/kg/day of MG extract), (iii) HFD + STZ (40 mg/kg i.p.), and (iv) HFD + STZ + MG. Following a 12-week administration of MG extract, significant reductions were observed in serum glucose, insulin, free fatty acid, cholesterol, and triglyceride levels in diabetic rats (p < .0001 for all). MG extract supplementation led to an increase in the total antioxidant capacity of the serum and a decrease in malondialdehyde (MDA) levels in both the serum and liver (p < .0001). Furthermore, hepatocellular fat accumulation was partially attenuated in the HFD + STZ + MG group. Notably, MG extract inhibited glycogen synthase kinase-3β (GSK-3β) in the liver (p < .01) and downregulated Fyn expression, resulting in elevated nuclear factor erythroid 2-related factor 2 (Nrf2) activity in the HFD + STZ + MG group compared to the HFD + STZ group (p < .05). The increased activity of Nrf2 in the HFD + STZ + MG group likely promoted the upregulation of heme oxygenase 1 (HO-1) in the liver (p < .0001). In conclusion, MG extract may exert antidiabetic effects by augmenting the antioxidant defense system through the regulation of GSK-3β/Fyn/Nrf2 in a rat model of type 2 diabetes.

Synthesis, Characterization and Biological Evaluation of Glycogen Synthase Kinase-3β Inhibitors as Antidiabetic Agents

Diabetes is a substantially growing unhealthiest in the globe that causes severe morbidity and mortality. Currently a day’s there’s an imperative for the invention, development and improvement of novel antidiabetic drug molecules. A chain of compound (5-imidazol-2-yl-4-phenylpyrimidin-2-yl) [2-(2- pyridyl amino) ethyl] amine were developed and synthesized by using suitable chemical synthetic techniques. These recently synthesized derivatives were characterized with the help of modern analytical techniques. This compound was evaluated for glycogen synthase kinase-3 enzyme inhibitor activities for managing of polygenic disease. GSK-3 inhibitors may advance and emerge as a novel strategy for the management of diabetes.

Apoptosis of Kinetin Riboside in Colorectal Cancer Cells Occurs by Promoting β-Catenin Degradation.

Kinetin riboside is a naturally produced cytokinin that displays strong antiproliferative activity in various human cancer cells. However, the mechanism of chemoprevention in colorectal cancer cells has not been elucidated. We used a cell-based reporter system to identify kinetin riboside as an antagonist of the Wnt/β-catenin pathway, which is aberrantly upregulated in colorectal cancer. Kinetin riboside suppressed β-catenin response transcription (CRT) by accelerating the degradation of intracellular β-catenin via a proteasomal degradation pathway. Pharmacological inhibition of glycogen synthase kinase-3β did not affect CRT downregulation. Kinetin riboside decreased the intracellular β-catenin levels in colorectal cancer cells with mutations in adenomatous polyposis coli (APC) and β-catenin. Consistently, kinetin riboside repressed expression of c-Myc and cyclin D1, β-catenin/T-cell factor (TCF)-dependent genes, and inhibited the proliferation of colorectal cancer cells. In addition, kinetin riboside stimulated apoptosis, as measured by an increase in annexin V-FITC-stained cells. These findings suggest that kinetin riboside exerts its anti-cancer activity by promoting β-catenin degradation and has significant potential as a chemopreventive agent for colorectal cancer cells.