GSK3B Research Articles

Evaluation of the Serum Dkk-1, Tenascin-C, Oxidative Stress Markers Levels and Wnt Signaling Pathway Genes Expression in Patients with Alzheimer's Disease.

Early diagnosis of Alzheimer's disease (AD) using potential biomarkers may help with implementing early therapeutic interventions, monitoring, and ultimately disease treatment. The current study aimed to evaluate serum levels of DKK-1, TNC, and oxidative stress markers, as well as analyzing the expression of LRP6, GSK3A, and GSK3B genes in patients with AD. Serum levels of DKK-1, TNC, TOS, TAC, and MDA were measured in 40 AD patients and 40 healthy individuals. Additionally, the relative expressions of LRP6, GSK3A, and GSK3B genes in whole blood were evaluated. Receiver operating characteristic (ROC) analysis was used to investigate the incremental diagnostic value of each factor in the study groups. Mean serum levels of DKK-1, TNC, TOS, TAC, and MDA were significantly higher in the AD group compared to the healthy group (p < 0.001). Moreover, a significant difference was observed in the expression of LRP6 and GSK3A genes (p < 0.001) between patients and healthy groups. However, the expression of GSK3B did not significantly differ between the two groups (p > 0.05). With considerable sensitivity and specificity, ROC analysis demonstrated the diagnostic efficacy of DKK-1 and TNC serum levels in AD within an area under the ROC curve of ≥ 0.98 (p ˂ 0.001). The results showed that evaluating serum levels of DKK-1 and TNC, as well as assessing the expression of LRP6, could be utilized for diagnosis and monitoring of AD patients.

Glycogen synthase kinase-3β inhibits tubular regeneration in acute kidney injury by a FoxM1-dependent mechanism.

Acute kidney injury (AKI) is characterized by injury to the tubular epithelium that leads to the sudden loss of renal function. Proper tubular regeneration is essential to prevent progression to chronic kidney disease. In this study, we examined the role of FoxM1, a forkhead box family member transcription factor in tubular repair after AKI. Renal FoxM1 expression increased after renal ischemia/reperfusion (I/R)-induced AKI in mouse kidneys. Treatment with thiostrepton, a FoxM1 inhibitor, reduced FoxM1 regulated pro-proliferative factors and cell proliferation in vitro, and tubular regeneration in mouse kidneys after AKI. Glycogen synthase kinase-3 (GSK3) was found to be an upstream regulator of FoxM1 because GSK3 inhibition or renal tubular GSK3β gene deletion significantly increased FoxM1 expression, and improved tubular repair and renal function. GSK3 inactivation increased β-catenin, Cyclin D1, and c-Myc, and reduced cell cycle inhibitors p21 and p27. Importantly, thiostrepton treatment abolished the improved tubular repair in GSK3β knockout mice following AKI. These results demonstrate that FoxM1 is important for renal tubular regeneration following AKI and that GSK3β suppresses tubular repair by inhibiting FoxM1.

Sodium orthovanadate improves learning and memory in intracerebroventricular-streptozotocin rat model of Alzheimer’s disease through modulation of brain insulin resistance induced tau pathology

Sporadic Alzheimer's disease (sAD) is the most common type of dementia and progressive neurodegenerative disease. To establish the sAD model, intracerebroventricular (ICV) streptozotocin (STZ) at a dose of 3 mg/kg was administered bilaterally in rats on a stereotaxic apparatus. Behavioral tests such as Morris water maze (MWM), novel object recognition (NOR) and open field test were performed to evaluate cognitive and locomotor functions. Two treatment doses (5 mg/kg and 10 mg/kg) of sodium orthovanadate (SOV) and rivastigmine (2 mg/kg) were given orally to ICV-STZ induced rats for 21 days. Cortical and hippocampal tissues were dissected. Estimation of oxidative stress, mitochondrial dysfunction as complex I, II, III, IV activity, cholinergic function as acetylcholinesterase activity, ELISA for phosphorylated tau protein and insulin degrading enzyme (IDE), neuroinflammation as NF-κB gene expression and insulin signaling functioning as Q-RT-PCR for IR, IRS-1, PI3K, AKT, GSK-3β gene expression were performed. Behavioral results with SOV and rivastigmine treatment revealed decreased escape latency and increased discrimination index in MWM and NOR respectively. Treatment results with SOV also demonstrated attenuation of oxidative imbalance, improved mitochondrial activity, and reversed IDE and tau pathology. SOV treatment upregulated gene expression of IR, IRS-1, PI3K, and AKT, and downregulated that of GSK-3β. SOV results were compared with standard drug rivastigmine. Conclusively, the memory enhancement by SOV was mediated through oxidative balance, mitochondrial enzyme complex activation, and improved insulin signaling regulation. However, the primary mechanism of SOV remained attenuation of tau pathology by the upregulation of IRS-1/PI3K/AKT/GSK-3β pathway and reversal of insulin resistance in terms of IDE. Hence, in sAD paradigm, SOV contributed to memory improvement evident with the findings of behavioral studies, which can further potentially have clinical significance in AD.

Glycogen Synthase Kinase-3β Mediates Proinflammatory Cytokine Secretion and Adipogenesis in Orbital Fibroblasts from Patients with Graves' Orbitopathy.

PurposeWe sought to determine the role of glycogen synthase kinase-3β (GSK-3β) in the pathogenesis of Graves’ orbitopathy(GO).MethodsExpression of the GSK-3β gene in whole orbital tissue explants was compared between GO and non-GO donors using quantitative real-time PCR (RT-PCR). The expression of proinflammatory molecules in the presence of the GSK-3β inhibitor CHIR 99021 was analyzed using RT-PCR, western blot, and ELISA. Adipogenic differentiation was identified using Oil Red O staining, and the levels of peroxisome proliferator activator gamma (PPARγ) and CCAAT-enhancer-binding proteins (C/EBPs) α and β were determined by western blot.ResultsThe expression of GSK-3β was significantly higher in GO tissues than in control tissues. The addition of CHIR 99021 led to a decrease in the active form of the kinase in which the Y216 residue is phosphorylated. When GO and non-GO fibroblasts were stimulated with IL-1β or TNF-α, IL-6, IL-8, intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-1 (COX-1), and monocyte chemoattractant protein 1 (MCP-1) showed increased production, which was blunted when CHIR 99021 was added. The activation of Akt, PI3K, nuclear factor (NF)-κB, Erk, Jnk, and p38 kinase by IL-1β and TNF-α was diminished with CHIR 99021 in GO cells. A decrease in lipid droplets and expression of PPARγ and c/EBPα and -β was noted in fibroblasts treated with CHIR 99021 during adipocyte differentiation. The inhibition of Wnt and β-catenin in adipogenesis was reversed by CHIR 99021.ConclusionsGSK-3β plays a significant role in GO pathogenesis. The inhibition of the kinase attenuated the proinflammatory cytokines production and fibroblast differentiation into adipocytes. GSK-3β may be a potential target for anti-inflammatory and anti-adipogenic treatment of GO.

Hyssopus officinalis exerts hypoglycemic effects on streptozotocin-induced diabetic rats via modulating GSK-3β, C-fos, NF-κB, ABCA1 and ABGA1 gene expression.

Type 2 diabetes mellitus (DMT2) is contributed to dual interactions between environmental factors and certain genetic factors. This impressed a great need for novel treatment strategy. Nevertheless, Hyssopus officinalis (H. officinalis) as a terrestrial herb is considered to be an important source of natural antioxidants, it could be assessed as an anti-hyperglycemic agent. In the current study, HPLC identified the active constitutes of H. officinalis, including total polyphenols, and flavonoids. Type 2 diabetes mellitus was induced in male Wistar albino rats via a single ip dose of streptozotocin (STZ) (35 mg/kg BW). One week post diabetes induction, rats were administrated H. officinalis (500 mg/ kg BW) orally for one month. Molecular analysis was assessed to investigate the efficiency of H. officinalis on modulating ATP-binding cassette transporter A1 (ABCA1) and G1 (ABCG1) genes, in addition to apoptotic biomarkers, glycogen synthase kinase-3β (GSK-3β) and cellular oncogene-fos (C-fos) genes. Furthermore, inflammatory biomarkers, nuclear factor kappa-B (NF-κB) and tumor necrosis factor-α (TNF-α) gene expression were also assessed. H. officinalis alcoholic extract declared the presence of polyphenols as gallic acid and flavonoids as quercetin in addition to many active constituents. Apigenin-7-glucoside and Chlorgenic acid were the most common constituents in the extract. RT-PCR results declared a significant up-regulation in mRNA gene expression of ABCA1 and ABCG1 upon H. officinalis treatment. Meanwhile, C-fos gene expression recorded a slight down-regulation. Gene expression of apoptotic biomarker GSK-3β demonstrated a significant down regulation as well as inflammatory biomarkers NF-κB and TNF-α. From the data recorded, it could be concluded that H. officinalis exerts a great hypoglycemic potential via modulating C-fos, GSK-3β, NF-κB, TNF-α, ABCA1 and ABCG1 gene expression and signaling pathways and could be considered as an effective candidate for DMT2 treatment.

Sulfated fucan/fucosylated chondroitin sulfate-dominated polysaccharide fraction from low-edible-value sea cucumber ameliorates type 2 diabetes in rats: New prospects for sea cucumber polysaccharide based-hypoglycemic functional food

Sulfated fucan chondroitin sulfate-dominated polysaccharide fraction from low-edible-value sea cucumber may be a good alternative to high-edible-value sea cucumber-derived polysaccharide for application in hypoglycemic functional foods. To evaluate the potential effect of low-edible-value sea cucumber-derived polysaccharide fraction on type 2 diabetes (T2DM), two sulfated fucan/fucosylated chondroitin sulfate-dominated polysaccharide fractions screening from 10 global commercial low-edible-value sea cucumber species were investigated to identify their anti-diabetics efficacies using a high-fat diet and streptozotocin-induced T2DM rat model. Sulfated fucan-dominated polysaccharide fraction from Thelenota ananas and fucosylated chondroitin sulfate-dominated polysaccharide fraction from Cucumaria frondosa ameliorated hyperglycemia, restored hypertriglyceridemia and hypercholesterolemia, decreased inflammatory status and oxidative stress, protected against liver injury, as well as improved insulin resistance and promoted accumulation of hepatic glycogen by activating IRS/PI3K/AKT signaling and regulating GSK-3β gene expression in T2DM rats. The current findings provide an available strategy for the commercialization of sea cucumber polysaccharide based-hypoglycemic functional food.

Orthosiphon stamineus Standardized Extract Reverses Streptozotocin-induced Alzheimer's Disease-Like Condition in a Rat Model.

Alzheimer’s disease (AD) is a chronic neurodegenerative brain disease that is characterized by impairment in cognitive functioning as well as the presence of intraneuronal neurofibrillary tangles (NFTs) and extracellular senile plaques. There is a growing interest in the potential of phytochemicals to improve memory, learning, and general cognitive abilities. The Malaysian herb Orthosiphon stamineus is a traditional remedy that possesses anti-inflammatory, anti-oxidant, and free-radical scavenging abilities, all of which are known to protect against AD. Previous studies have reported that intracerebroventricular (ICV) administration of streptozotocin (STZ) mimics a condition similar to that observed in AD. This experiment thus aimed to explore if an ethanolic leaf extract of O. stamineus has the potential to be a novel treatment for AD in a rat model and can reverse the STZ- induced learning and memory dysfunction. The results of this study indicate that O. stamineus has the potential to be potentially effective against AD-like condition, as both behavioral models employed in this study was observed to be able to reverse memory impairment. Treatment with the extract was able to decrease the up-regulated expression levels of amyloid precursor protein (APP), microtubule associated protein tau (MAPT), Nuclear factor kappa-light-chain-enhancer of activated B cells (NFᴋB), glycogen synthase kinase 3 alpha (GSK3α), and glycogen synthase kinase 3 beta (GSK3β) genes indicating the extract’s neuroprotective ability. These research findings suggest that the O. stamineus ethanolic extract demonstrated an improved effect on memory, and hence, could serve as a potential therapeutic target for the treatment of neurodegenerative diseases such as AD.

Enhanced conditioning of adverse memories in the mouse modified swim test is associated with neuroinflammatory changes - Effects that are susceptible to antidepressants.

Deficient learning and memory are well-established pathophysiologic features of depression, however, mechanisms of the enhanced learning of aversive experiences associated with this disorder are poorly understood. Currently, neurobiological mechanisms of enhanced retention of aversive memories during depression, and, in particular, their relation to neuroinflammation are unclear. As the association between major depressive disorder and inflammation has been recognized for some time, we aimed to address whether neuroinflammatory changes are involved in enhanced learning of adversity in a depressive state. To study this question, we used a recently described mouse model of enhanced contextual conditioning of aversive memories, the modified forced swim model (modFST). In this model, the classic two-day forced swim is followed by an additional delayed session on Day 5, where increased floating behaviour and upregulated glycogen synthase kinase-3 (GSK-3) are context-dependent. Here, increased time spent floating on Day 5, a parameter of enhanced learning of the adverse context, was accompanied by hypercorticosteronemia, increased gene expression of GSK-3α, GSK-3β, c-Fos, cyclooxygenase-1 (COX-1) and pro-inflammatory cytokines interleukin-1 beta (IL-1β), tumor necrosis factor (TNF), and elevated concentrations of protein carbonyl, a marker of oxidative stress, in the prefrontal cortex and hippocampus. There were significant correlations between cytokine levels and GSK-3β gene expression. Two-week administration of compounds with antidepressant properties, imipramine (7mg/kg/day) or thiamine (vitamin B1; 200mg/kg/day) ameliorated most of the modFST-induced changes. Thus, enhanced learning of adverse memories is associated with pro-inflammatory changes that should be considered for optimizing pharmacotherapy of depression associated with enhanced learning of aversive memories.

Polyphyllin I attenuates pressure over-load induced cardiac hypertrophy via inhibition of Wnt/β-catenin signaling pathway

AimsCardiac hypertrophy is one of most important risk factors for cardiovascular mortality. Activation of Wnt/β-catenin signaling pathway is acknowledged to be an important mechanism for pathogenesis of cardiac hypertrophy. Polyphyllin I (PPI), a component in the traditional Chinese medicinal herb, has shown anticancer effect partially via interruption of Wnt/β-catenin signaling pathway. Our aim was to test whether PPI attenuates cardiac hypertrophy. Materials and methodsAdult male C57BL/6J mice were subjected to either pressure overload generated by transverse aortic constriction (TAC) or sham surgery (control group). Angiotensin-II (Ang-II) was used to induce cardiomyocyte hypertrophy in vitro. PPI was intraperitoneally administrated daily for 4 weeks after TAC surgery and then cardiac function was determined by echocardiography and histological analysis was performed. Key findingsPPI significantly ameliorated cardiac dysfunction of mice subjected to TAC. Meanwhile, PPI attenuated TAC induced cardiac hypertrophy indicated by blunted increase in heart mass, cross section area of cardiomyocyte, cardiac fibrosis and expression of hypertrophic biomarkers ANP, BNP and β-MHC. In addition, PPI also ameliorated Ang-II induced cardiomyocyte hypertrophy in vitro. Importantly, PPI decreased protein expression of active β-catenin/total β-catenin, phosphorylation of GSK3β and Wnt target genes c-myc, c-jun, c-fos and cyclin D1 and its anti-hypertrophic effect was blunted by supplementation of Wnt 3a. SignificanceOur results suggest that PPI attenuates cardiac dysfunction and attenuate development of pressure over-load induced cardiac hypertrophic via suppressing Wnt/β-catenin signaling pathway. PPI might be a candidate drug for treatment of cardiac hypertrophy.

A specific group of patients with diagnostic conversion from depression to bipolar disorder and finally to dementia as a mental GSK-3 disease: A hypothesis.

To focus on a specific group of patients whose diagnoses were changed from unipolar depression to bipolar disorder, and finally to dementia. Qualitative review of the relevant articles. A substantial portion of patients with unipolar depression manifest manic and/or hypomanic episodes, resulting in a change of diagnoses to bipolar disorder. Further, a substantial portion of bipolar patients develop dementia. Previous research suggests that genetic variants in the glycogen synthase kinase 3β (GSK-3β) gene are associated with early onset of unipolar depression, a subset of which may be bipolar depression, with three SNPs (rs334555, rs119258668, and rs11927974) identified. Notably, another promotor SNP (rs334558) of the GSK-3β gene is reportedly associated with unipolar depression, bipolar disorders, and dementia. Additionally, lithium, which is reported to inhibit GSK-3, is generally accepted to be effective for bipolar disorder and recently reported to be effective for dementia. There is a specific group of patients whose diagnoses longitudinally change from depression to bipolar disorder and finally to dementia, and GSK-3 may be a common etiological factor in these diseases and in diagnostic conversions.

Abstract B092: Assessment of glycogen synthase kinase-3 beta (GSK3β) genomic landscape to inform use of cancer therapeutics

Abstract Background: GSK3β, a serine/threonine kinase, has been implicated in the pathogenesis of many cancers. It can act both as a tumor suppressor and a proto-oncogene. Overexpression of GSK3β promotes tumor growth and chemotherapy resistance. Genomic alterations in GSK3β have been identified in many cancer types but no comprehensive analysis is available. Characterization of both the landscape and functional implications of GSK3β alterations will be critical to guide patient selection for treatment with GSK3β inhibitors and related combinations in clinical development, including 9-ING-41, a first-in-class, small molecule potent selective GSK3β inhibitor currently in phase 1/2 clinical trial (NCT03678883). Methods: Publicly-available tumor genomic data was accessed from cBioPortal. Data from 159 studies, curated to exclude duplicate tumor samples, was analyzed. Tumor samples with a GSK3β genomic alteration, including mutations or copy number variations (CNV), were included for analysis. For each tumor, histology, GSK3β protein change or type of CNV, and predicted functional impact of mutation were obtained. Results: 42,199 tumor samples were assessed for GSK3β genomic alterations that were identified in approximately 1% of the specimens (n=414). GSK3β mutations, fusions, frameshift insertions/deletions, and splice site mutations, were present in 211 (0.5%) tumors. Missense mutations were most prevalent (67%). Of 117 unique missense mutations, 68% were predicted to be deleterious by SIFT criteria, while 66% were predicted to be at least possibly damaging by Polyphen-2. Of all mutations, 58% were found in the GSK3β kinase domain. Of all 211 tumors, 10 (5%) had mutations in one of three key GSK3β residues that form a binding pocket for the phosphate group of a primed substrate (R96, R180, and K205). R96 and R180 were found to be of the most commonly mutated residues in this dataset. Cancers most frequently containing a GSK3β mutation were uterine endometrioid carcinoma (n=30, 5% of all cBioPortal uterine endometrioid carcinoma samples included in 42,199 analyzed tumors), melanoma (n=24, 2%) colorectal adenocarcinoma (n=30, 1%), and lung adenocarcinoma (n=19, 1%). GSK3β gene fusions were identified in 17 cases with prostate cancer being the most frequent cancer type (53%). GSK3β CNV, including amplification and homozygous deletion, were found in 217 (0.5%) tumors. Cancers most frequently containing GSK3β CNV were cervical squamous cell carcinoma (n=15, 6%), lung squamous cell carcinoma (n=36, 5%), head and neck squamous cell carcinoma (n=15, 3%), serous ovarian cancer (n=15, 3%), prostate adenocarcinoma (n=40, 2%), and breast invasive ductal carcinoma (n=18, 1%). Conclusions: GSK3β genomic alterations are present in a subset of several malignancies (1-6%). Commonly mutated residues include those that form the binding pocket for the phosphate group of a primed GSK3β substrate, and the majority of GSK3β mutations occur in the kinase domain. The most commonly mutated histologies are distinct from those with GSK3β CNV. Ongoing additional analyses include assessment of the GSK3β genomic landscape in an expanded cohort and functional and pathway analyses to investigate potential biomarkers for treatment response or resistance to selective GSK3β inhibitor 9-ING-41. Citation Format: Brittany A. Borden, Lorin Crawford, Howard P. Safran, Francis J. Giles, Wafik S. El-Deiry, Benedito A. Carneiro. Assessment of glycogen synthase kinase-3 beta (GSK3β) genomic landscape to inform use of cancer therapeutics [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B092. doi:10.1158/1535-7163.TARG-19-B092

Structural variation in the glycogen synthase kinase 3β and brain-derived neurotrophic factor genes in Japanese patients with bipolar disorders.

BackgroundLithium is the first‐line drug for the treatment of bipolar disorders (BDs); however, not all patients responded. Glycogen synthase kinase (GSK) 3β and brain‐derived neurotrophic factor (BDNF) play a role in the therapeutic action of lithium. Since structural variations were reported in these genes, it is possible that these genomic variations may be involved in the therapeutic responses to lithium.MethodFifty patients with BDs and 50 healthy subjects (mean age 55.0 ± 15.0 years; M/F 19/31) participated. We examined structural variation of the GSK3β and BDNF genes by real‐time PCR. We examined the influence of structural variation of these genes on the therapeutic responses to lithium and the occurrence of antidepressant‐emergent affective switch (AEAS). The efficacy of lithium was assessed using the Alda scale, and AEAS was evaluated using Young Mania Rating Scale.ResultsAlthough we examined structural variations within intron II and VII of the GSK3® gene and from the end of exon IV to intron IV and within exon IX of the BDNF gene, no structural variation was found in BDs. Whereas 5 of 50 patients exhibited three copies of the genomic region within exon IV of the BDNF gene, all healthy subjects had two copies. No difference in the therapeutic efficacy of lithium was found between patients with three and two copies. No difference in the occurrence of AEAS was found between the two groups.ConclusionThe amplification of the BDNF gene influenced neither the therapeutic responses to lithium nor the occurrence of AEAS.

Testosterone supplementation improves insulin responsiveness in HFD fed male T2DM mice and potentiates insulin signaling in the skeletal muscle and C2C12 myocyte cell line.

BackgroundType 2 Diabetes Mellitus (T2DM) is characterised by hyperglycemia due to the incidence of insulin resistance. Testosterone supplementation has been shown to have a positive co-relation with improved glycemic control in T2DM males. Clinical studies have reported that Androgen Replacement Therapy (ART) to hypogonadic males with T2DM resulted in improved glycemic control and metabolic parameters, but, these studies did not address in detail how testosterone acted on the key glucose homeostatic organs.MethodIn this study, we delineate the effect of testosterone supplementation to high-fat diet (HFD) induced T2DM in male C57BL6J mice and the effect of testosterone supplementation on the skeletal muscle insulin responsiveness. We also studied the effect of testosterone on the insulin signaling pathway proteins in C2C12 myocyte cells to validate the in vivo findings.ResultsWe found that testosterone had a potentiating effect on the skeletal muscle insulin signaling pathway to improve glycaemic control. We demonstrate that, in males, testosterone improves skeletal muscle insulin responsiveness by potentiating the PI3K-AKT pathway. The testosterone treated animals showed significant increase in the skeletal muscle Insulin Receptor (IR), p85 subunit of PI3K, P-GSK3α (Ser-21), and P-AKT (Ser-473) levels as compared to the control animals; but there was no significant change in total AKT and GSK3α. Testosterone supplementation inhibited GSK3α in the myocytes in a PI3K/AKT pathway dependent manner; on the other hand GSK3β gene expression was reduced in the skeletal muscle upon testosterone supplementation.ConclusionTestosterone increases insulin responsiveness by potentiating insulin signaling in the skeletal muscle cells, which is in contrast to the increased insulin resistance in the liver of testosterone treated T2DM male animals.

Effect of Epigallocatechin Gallate and Catechin on Overexpression of GSK-3β and IR Genes Induced by Streptozotocin in Rat Brain

Background: Type 2 diabetes mellitus (T2DM) is one of the significant risk factors for Alzheimer disease (AD). Defects in insulin signaling pathway induce AD hallmarks mainly through activation of glycogen synthase kinase-3β (GSK-3β) pathway. Objectives: In this study, we investigated the expression of GSK-3β and insulin receptor (IR) genes in the hippocampi of an animal model of sporadic AD and assessed the preventive effect of Catechin (CAT) and epigallocatechin gallate (EGCG) on their expression. Materials &amp; Methods: Adult male Wistar rats were treated by intracerebroventricular streptozotocin (STZ) injection (3 mg/kg) at day 1 and 3 after cannulation. CAT was administered at a dose of 40 mg/kg for 10 days per gavage, and EGCG was administered at a dose of 3 mg/kg for 14 days into drinking water. Then the animals were decapitated, and their hippocampi were removed. Real-time Polymerase Chain Reaction (PCR) was used to evaluate the alteration in gene expression. Results: There was overexpression in GSK-3β gene in STZ-treated rats (P≤0.05), which was brought back to normalcy by EGCG (P≤0.01). The IR gene also increased after STZ treatment, but CAT reduced IR expression (P≤0.05). However, the suppressive effect of EGCG on IR expression was stronger (P≤0.01). Conclusion: The neuroprotective activity of EGCG might be due to its influence on IR and GSK-3β expression.

Famotidine has a neuroprotective effect on MK-801 induced toxicity via the Akt/GSK-3β/β-catenin signaling pathway in the SH-SY5Y cell line

Schizophrenia cannot be treated sufficiently with existing antipsychotic drugs. Taken into account that increased Glycogen Synthase Kinase 3 Beta (GSK-3β) activity is associated with schizophrenia pathophysiology and certain antipsychotics can be able to decrease GSK3β activity, inhibition of GSK-3β activity could be a novel approach for the treatment of schizophrenia. In the present study MK-801, a widely used chemical for the in vivo/in vitro modeling of schizophrenia was selected to evoke a detrimental effect on cellular survival via GSK3β and related proteins. A limited number of studies have reported the curative effects of famotidine, an antiulcer drug, in schizophrenic patients. To the best of our knowledge, no study investigated the molecular mechanism of the beneficial effect of famotidine in the patients. A recent study based on computerized drug modeling software (docking) indicated that famotidine might inhibit the GSK3β activity due to its chemical structure independent from histaminergic receptors. In this study, we aimed to investigate the effects of famotidine on the Akt/GSK-3β/β-catenin signaling pathway on SH-SY5Y neuroblastoma cells in the presence of MK-801. We investigated the effects of famotidine, olanzapine (an antipsychotic drug), and SB 415286 (specific GSK-3β inhibitor), on the basal cellular survival and MK-801 induced neuronal death beside of Akt/GSK-3β/β-catenin protein and gene expressions in SH-SY5Y cells. Cell viability, protein and gene expressions were determined by the real-time cell analysis (xCELLigence) system, western blotting and real-time polymerase chain reactions (Rt-PCR), respectively. Our findings suggested that MK-801 administration decreased cell survival probably via the increasing GSK-3β gene expression and activity in the SH-SY5Y cells. Pre-treatments with famotidine, olanzapine, and SB 415286 prevented MK-801 induced cell death via inhibitory effects on the MK-801 induced GSK-3β activity. Overall, the present results suggest that famotidine has a neuroprotective effect against MK-801 via modulation of the Akt/GSK-3β/β-catenin signaling pathway, an important mechanism in schizophrenia neurobiology.

Targeting glycogen synthase kinase 3 for therapeutic benefit in lymphoma

AbstractTargeting the B-cell receptor and phosphatidylinositol 3-kinase/mTOR signaling pathways has shown meaningful, but incomplete, antitumor activity in lymphoma. Glycogen synthase kinase 3 (GSK3) α and β are 2 homologous and functionally overlapping serine/threonine kinases that phosphorylate multiple protein substrates in several key signaling pathways. To date, no agent targeting GSK3 has been approved for lymphoma therapy. We show that lymphoma cells abundantly express GSK3α and GSK3β compared with normal B and T lymphocytes at the messenger RNA and protein levels. Utilizing a new GSK3 inhibitor 9-ING-41 and by genetic deletion of GSK3α and GSK3β genes using CRISPR/CAS9 knockout, GSK3 was demonstrated to be functionally important to lymphoma cell growth and proliferation. GSK3β binds to centrosomes and microtubules, and lymphoma cells treated with 9-ING-41 become arrested in mitotic prophase, supporting the notion that GSK3β is necessary for the progression of mitosis. By analyzing recently published RNA sequencing data on 234 diffuse large B-cell lymphoma patients, we found that higher expression of GSK3α or GSK3β correlates well with shorter overall survival. These data provide rationale for testing GSK3 inhibitors in lymphoma patient trials.

Abstract 2640: DKK1 overexpression might induce crizotinib resistance

Abstract NSCLC patients with pleural effusions tend to show progressive status and malignant features. Newly established lung cancer cell lines from pleural effusions, SNU-2550 and SNU-2563 were harboring ALK rearrangement and they were originally sensitive to crizotinib. After treated with regular crizotinib treatment and recovery at least 1 year, crizotinib-resistant cell lines (SNU-2550CR and SNU-2563CR) that became resistant to crizotinib more than 5 times were established. And then, whole exome sequencing (WES) and RNA-seq were operated in order to understand way to acquire resistance. According to WES result, there were differences in mutations between parental cell lines and resistant cell lines. For example, mutations in MKNK2, IGFN1, PRSS1 and FOXA2 genes were only present in SNU-2550CR not SNU-2550. Variations of ESX1, PRSS1, PCDHA4 and AGAP3 genes were observed in only SNU-2563CR. When the differences were studied and visualized via SPIA two-way evidence plot and heatmap, genes related with cell cycle, p53 and Wnt pathway were commonly changed in RNA expression level. In fact, there were expressional differences in genes related those pathways such as MAPK2, DKK1, APC and GSK3b genes. Among them, Dkk1 expression level was more than doubled in two set. Through those analysis, we examined differences between parental cell lines that have sensitive reactivity and resistant cell lines that acquired resistance. When crizotinib resistance was induced, Dkk1 expression was elevated. Augmentation of Dkk1 expression level induces the level of overall β-catenin expression, and cytoplasmic β-catenin tends to be concentrated adjacent to membrane and into nucleus region. Therefore, Dkk1 can be considered as a factor that is related to crizotinib resistance by up-regulating Wnt/β-catenin pathway in lung cancer. Acquired resistance to crizotinib is major predicament especially when there is ALK rearrangement. Studying the mechanism of crizotinib resistance therefore improves the prognosis of ALK rearrangement lung cancer. We found that Dkk1 overexpression might be correlated to crizotinib resistance. Note: This abstract was not presented at the meeting. Citation Format: Ha Young Seo. DKK1 overexpression might induce crizotinib resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2640.

Brain Volume-Related Polymorphisms of the Glycogen Synthase Kinase-3β Gene and Their Effect on Antidepressant Treatment in Major Depressive Disorder

Background: Glycogen synthase kinase-3β (GSK-3β) polymorphisms are known to influence hippocampal brain tissue volume in individuals with major depressive disorder (MDD). However, the effects of the GSK-3β gene single nucleotide polymorphisms (SNPs) in those receiving antidepressant therapy are unknown. Objectives: In the present study, we examined the relationship between brain volume-related SNPs of the GSK-3β gene and antidepressant treatment effects in patients with MDD. Methods: Paroxetine, fluvoxamine, or milnacipran was administered to 143 Japanese patients with MDD. Two SNPs of the GSK-3β gene (rs6438552 and rs12630592) that influence brain volume in the hippocampus were genotyped. For the primary outcome, the relationship between genetic variations in the SNPs and the percent change in the Hamilton Rating Scale for Depression (HAM-D) score at week 6 was examined. In addition, rs334558, which has been reported repeatedly, was also genotyped. Results: There was a significant correlation between the two SNPs and the percent change in the HAM-D scores at week 6 (rs6438552 A/A vs. A/G + G/G: p = 0.016; rs12630592 G/G vs. G/T + T/T: p = 0.016). There was high linkage disequilibrium between the rs6438552 and rs12630592 SNPs. The correlation between high therapeutic response over time and the two SNPs were also confirmed (rs6438552 A/A vs. others: p = 0.031; rs12630592 G/G vs. others: p = 0.031). Conclusions: Our results suggest that two GSK-3β variants that influence brain volume were associated with changes in the HAM-D scores at week 6 in patients with MDD.

Effects of different starch sources on glucose and fat metabolism in broiler chickens

ABSTRACT 1. The aim of the present study was to investigate the effects of different starch sources (corn, wheat, and rice) on the blood glucose level, glycogen content of liver and muscle, expression of GSK-3β and FAS mRNA, abdominal fat weight and abdominal fat deposition in broiler chickens. 2. A total of 360, one-day-old AA (Arbor Acres) broiler chickens were randomly assigned to three treatment groups, each with six replicates, consisting of 20 chickens per replicate, and fed either a corn-, wheat- or rice-based diet for 21 days. The chickens were then subdivided into groups A and B, and the chickens in these two subgroups were processed or sampled for 28 days, respectively. 3. The results indicated that post-prandial time significantly affected the glucose concentration, glycogen content in the liver and breast muscle and expression of GSK-3β and FAS mRNAs (P < 0.05). The expression of the GSK-3β gene in the chicken liver of the corn-based diet group was higher (P < 0.05) than that in the wheat-based diet group, and the expression of the FAS gene in the corn-based diet group was lower (P < 0.05) than that in the wheat-based and rice-based diet groups. Abdominal fat weight and deposition in the corn-based diet group were lower than those of the wheat-based and rice-based diet groups, but these differences were not significant (P > 0.05). 4. The results suggested that the efficiency of glucose absorption in animals might have an effect on the fat deposition efficiency in the liver and that diets with different starch sources might affect fat deposition in chickens.

Silencing GSK3β instead of DKK1 can inhibit osteogenic differentiation caused by co-exposure to fluoride and arsenic

Chronic exposure to combined fluoride (F) and arsenic (As) continues to be a major public health problem worldwide, attracting the attention of an increasing number of researchers. While bone is the main target organ of syndrome of endemic arsenic poisoning and fluorosis (SEAF), the specific mechanism and targeted intervention remains uncertain. The first question in this study sought to determine the interaction of F and As on the Wnt signaling pathway and its role in osteogenic differentiation in the SEAF population. As can be seen from the data, with the increase in exposure to F, the content of Wnt signaling inhibitor Dickkopf-related protein 1 (DKK1) gradually decreased, but the expression of glycogen synthase kinase-3β (GSK3β), β-catenin and the osteogenic differentiation indicators pro-collagen I alpha 1 (COL1A1) and bone alkaline phosphatase (BALP) were increased. Next, we grouped the SEAF population according to urinary As and found that As can upregulate the GSK3β, β-catenin level and the bone formation bio-marker BALP in serum. But the experiments did not detect any evidence that As can change the content of DKK1 in serum. To better understand the combined effects of F and As on the Wnt signaling pathway, we performed further interaction analysis. These results suggest that the interaction of F and As can inhibit the GSK3β, β-catenin, COL1A1 and BALP. And DKK1 is mainly manifested by the independent effect of F. To further study the role of DKK1 and GSK3β in fluoride-arsenic pollution combined with osteogenic differentiation, we attempted to silence the DKK1 and GSK3β gene in hFOB 1.19 cells. The results show that F, As alone and in combination exposure can up-regulate GSK catenin transcription and protein expression levels and down-regulate DKK1, and COL1A1 and ALP are significantly increased, after silenced the DKK1. The same results did not appear after silenced the GSK3β. F and As alone and in combination exposure did not reverse the inhibition of GSK3β and β-catenin by GSK3β silencing, and COL1A1 and ALP are significantly decreased. The results indicate that silencing GSK3β instead of DKK1 can inhibit osteogenic differentiation caused by co-exposure to fluoride and arsenic. This study can provide a scientific basis for further understanding the causes of bone formation caused by F and As and the improvement of targeted intervention strategies.