Developmental Perfluorooctanesulfonic acid (PFOS) exposure as a potential risk factor for late-onset Alzheimer's disease in CD-1 mice and SH-SY5Y cells.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that accounts for approximately 60-80% of dementia cases worldwide and is characterized by an accumulation of extracellular senile plaques composed of ß-amyloid (Aß) peptide and intracellular neurofibrillary tangles (NFTs) containing hyperphosphorylated tau protein. Sporadic or late-onset AD (LOAD) represents 95 % of the AD cases and its etiology does not appear to follow Mendelian laws of inheritance, thus, implicating the role of epigenetic programming and environmental factors. Apolipoprotein allele 4 (ApoE4), the only established genetic risk factor for LOAD, is suggested to accelerate the pathogenesis of AD by increasing tau hyperphosphorylation, inhibiting the clearance of amyloid-ß (Aß), and promoting Aß aggregation. Perfluorooctanesulfonic acid (PFOS) is a persistent organic pollutant, with potential neurotoxic effects, that poses a major threat to the ecosystem and human health. By employing in vivo and in vitro models, the present study investigated PFOS as a potential risk factor for LOAD by assessing its impact on amyloidogenesis, tau pathology, and rodent behavior. Our behavioral analysis revealed that developmentally exposed male and female mice exhibited a strong trend of increased rearing and significantly increased distance traveled in the open field test. Biochemically, GSK3ß and total ApoE were increased following developmental exposure, in vivo. Furthermore, in vitro, low concentrations of PFOS elevated protein levels of APP, tau, and its site-specific phosphorylation. Differentiated SH-SY5Y cells exposed to a series of PFOS concentrations, also, had elevated protein expression of GSK3ß. These data suggest that total ApoE is inducible by environmental exposure to PFOS.

Lithium Chloride Protects against Sepsis-Induced Skeletal Muscle Atrophy and Cancer Cachexia.

Inflammation-mediated skeletal muscle wasting occurs in patients with sepsis and cancer cachexia. Both conditions severely affect patient morbidity and mortality. Lithium chloride has previously been shown to enhance myogenesis and prevent certain forms of muscular dystrophy. However, to our knowledge, the effect of lithium chloride treatment on sepsis-induced muscle atrophy and cancer cachexia has not yet been investigated. In this study, we aimed to examine the effects of lithium chloride using in vitro and in vivo models of cancer cachexia and sepsis. Lithium chloride prevented wasting in myotubes cultured with cancer cell-conditioned media, maintained the expression of the muscle fiber contractile protein, myosin heavy chain 2, and inhibited the upregulation of the E3 ubiquitin ligase, Atrogin-1. In addition, it inhibited the upregulation of inflammation-associated cytokines in macrophages treated with lipopolysaccharide. In the animal model of sepsis, lithium chloride treatment improved body weight, increased muscle mass, preserved the survival of larger fibers, and decreased the expression of muscle-wasting effector genes. In a model of cancer cachexia, lithium chloride increased muscle mass, enhanced muscle strength, and increased fiber cross-sectional area, with no significant effect on tumor mass. These results indicate that lithium chloride exerts therapeutic effects on inflammation-mediated skeletal muscle wasting, such as sepsis-induced muscle atrophy and cancer cachexia.

Effects of Yixintai Pills on Myocardial Cell Apoptosis in Rats With Adriamycin-Induced Heart Failure.

OBJECTIVE: To study the effects of Yixintai pills on myocardial cell apoptosis in rats with adriamycin (ADR)-induced heart failure (HF) and the mechanism of action. METHODS: Sixty healthy male Wistar rats randomly were divided into Control, Model, Captopril, and Yixintai pill groups. A rat model of ADR-induced HF was constructed by intraperitoneal injection of ADR (2.5 mg/kg). The control group was given an equal volume of normal saline; the Yixintai pill and Captopril groups were given corresponding mediations (5 mg/kg) by lavage. After 4 weeks of treatment, fasting blood was collected to detect the contents of plasma rennin activity (PRA), angiotensin II (AngII), and aldosterone (ALD). B ultrasound was used to detect the heart structure, and the heart weight/body weight (HW/BW) ratio was calculated. The pathology of myocardial tissues was observed by HE staining. The apoptosis of myocardial cells was detected by TUNEL assay. The expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in serum were analyzed by ELISA, and the protein expression levels of protein kinase B (Akt), phosphorylated (p)-Akt, glycogen synthase kinase-3ß (GSK-3ß) and p-GSK-3ß in myocardial tissues were measured by Western blotting. RESULTS: Compared with the Control group, the PRA, AngII, ALD, left ventricular posterior wall thickness at end-systole (LVPWs), left ventricular posterior wall thickness at end-diastole (LVPWd), interventricular septal thickness at end-systole (IVSs), interventricular septal thickness at end-diastole (IVSd), HW/BW, TNF-α and IL-6 of model group increased significantly (P < .05). PRA, AngII, ALD, LVPWs, LVPWd, IVSs, IVSd, HW/BW, TNF-α and IL-6 of the Yixintai pill and Captopril groups were significantly lower than those of the Model group (P < .05). There were no significant differences in the indices between the Yixintai pill and Captopril groups (P > .05). In the Model group, lamellar necrosis, vacuolar degeneration, increased myocardial fibers and lamellar dissolution of myocardial cells were found in myocardial tissues. However, the myocardial cells of the Control group were neatly arranged and clearly structured, and only a few ones underwent fibrosis. There were mild myocardial fibrosis and vacuolar degeneration in the Yixintai pill and Captopril groups, and the degeneration and hyperplasia of myocardial fibers were obviously relieved. Compared with the Control group, the apoptosis index (AI) of the Model group increased significantly (P < .05). The AI values of the Yixintai pill and Captopril groups were significantly lower than those of the Model group (P < .05). Compared with the Control group, the expression levels of p-Akt and p-GSK-3ß in the Model group decreased significantly (P < .05). The expression levels of p-Akt and p-GSK-3ß in the Yixintai pill and Captopril groups were significantly higher than those of the Model group (P < .05), whereas the former 2 groups had similar results (P > 0.05). CONCLUSION: Yixintai pills may inhibit myocardial cell apoptosis and ventricular remodeling in rats by up-regulating PI3K/Akt/GSK-3ß signal, thus protecting the heart function.

Salidroside inhibits platelet function and thrombus formation through AKT/GSK3ß signaling pathway.

Salidroside is the main bioactive component in Rhodiola rosea and possesses multiple biological and pharmacological properties. However, whether salidroside affects platelet function remains unclear. Our study aims to investigate salidroside's effect on platelet function. Human or mouse platelets were treated with salidroside (0-20 µM) for 1 hour at 37°C. Platelet aggregation, granule secretion, and receptors expression were measured together with detection of platelet spreading and clot retraction. In addition, salidroside (20 mg/kg) was intraperitoneally injected into mice followed by measuring tail bleeding time, arterial and venous thrombosis. Salidroside inhibited thrombin- or CRP-induced platelet aggregation and ATP release and did not affect the expression of P-selectin, glycoprotein (GP) Ibα, GPVI and αIIbß3. Salidroside-treated platelets presented decreased spreading on fibrinogen or collagen and reduced clot retraction with decreased phosphorylation of c-Src, Syk and PLCγ2. Additionally, salidroside significantly impaired hemostasis, arterial and venous thrombus formation in mice. Moreover, in thrombin-stimulated platelets, salidroside inhibited phosphorylation of AKT (T308/S473) and GSK3ß (Ser9). Further, addition of GSK3ß inhibitor reversed the inhibitory effect of salidroside on platelet aggregation and clot retraction. In conclusion, salidroside inhibits platelet function and thrombosis via AKT/GSK3ß signaling, suggesting that salidroside may be a novel therapeutic drug for treating thrombotic or cardiovascular diseases.

Phytic acid attenuates upregulation of GSK-3ß and disturbance of synaptic vesicle recycling in MPTP-induced Parkinson's disease models.

Heightened activity of glycogen synthase kinase-3ß (GSK-3ß) is linked to the degeneration of dopaminergic neurons in Parkinson's disease (PD). Phytic acid (PA), a naturally occurring compound with potent antioxidant property, has been shown to confer neuroprotection on dopaminergic neurons in PD. However, the underlying mechanism remains unclear. In the present study, MPTP and MPP+ treatments were used to model PD in mice and SH-SY5Y cells, respectively. We observed reduced tissue dopamine, disrupted synaptic vesicle recycling, and defective neurotransmitter exocytosis. Furthermore, expression of GSK-3ß was upregulated while that of ß-catenin was downregulated, concentration of cytosolic calcium was increased, and expressions of two dopamine carriers, dopamine transporter (DAT) and vesicular monoamine transporter 2 (VMAT2) were decreased. PA treatment attenuated the MPTP-induced upregulation of GSK-3ß, increase in cytosolic calcium concentration, decreases in the levels of DAT, VMAT2, tissue dopamine, and synaptic vesicle recycling. Importantly, disturbances in synaptic vesicle recycling are thought to be early events in PD pathology. These findings suggest that PA is a promising therapeutic agent to treat early events in PD.

LncRNA BDNF-AS suppresses colorectal cancer cell proliferation and migration by epigenetically repressing GSK-3ß expression.

This study was designed to investigate the molecular mechanism and biological roles of long non-coding RNA (lncRNA) brain-derived neurotrophic factor antisense (BDNF-AS) in colorectal cancer (CRC). The quantitative real-time PCR (qRT-PCR) and western blotting were performed to detect the expressions of lncRNA BDNF-AS and glycogen synthase kinase-3ß (GSK-3ß) in human CRC tissues and cell lines. The cell proliferation, transwell migration, and invasion assays were carried out to evaluate the effect of lncRNA BDNF-AS on the growth of CRC cells. RNA pull-down and RNA immunoprecipitation (RIP) assays were conducted to confirm the interaction between lncRNA BDNF-AS and enhancer of Zeste Homologue 2 (EZH2). Chromatin immunoprecipitation (ChIP) assay was used to verify the enrichment of EZH2 and histone H3 lysine 27 trimethylation (H3K27me3) in the promoter region of GSK-3ß in CRC cells. LncRNA BDNF-AS expression was significantly decreased, while GSK-3ß was highly expressed in human CRC tissues and cell lines. Moreover, lncRNA BDNF-AS induced inhibition of proliferation, migration, and invasion of CRC cells via inhibiting GSK-3ß expression. Mechanistically, BDNF-AS led to GSK-3ß promoter silencing in CRC cells through recruitment of EZH2. In conclusion, lncRNA BDNF-AS functioned as an oncogene in CRC and shed new light on lncRNA-directed therapeutics in CRC. SIGNIFICANCE OF THE STUDY: LncRNA BDNF-AS is recently reported to be remarkably downregulated in a variety of tumours and served as a tumour suppressor. However, the functions and underlying mechanism of lncRNA BDNF-AS in CRC pathogenesis have not been reported yet. Our study is the first to demonstrate the effect of lncRNA BDNF-AS in CRC and revealed that lncRNA BDNF-AS expression is negatively correlated with the aggressive biological behaviour of CRC. Further investigation demonstrated that lncRNA BDNF-AS functioned as a tumour suppressor in CRC progression by suppressing GSK-3ß expression through binding to EZH2 and H3K27me3 with the GSK-3ß promoter, shedding light on the diagnosis and therapy for CRC.

Modulation by chronic antipsychotic administration of PKA- and GSK3ß-mediated pathways and the NMDA receptor in rat ventral midbrain.

RATIONALE: Antipsychotics exert therapeutic effects by modulating various cellular signalling pathways and several types of receptors, including PKA- and GSK3ß-mediated signalling pathways, and NMDA receptors. The ventral midbrain, mainly containing the ventral tegmental area (VTA) and substantia nigra (SN), are the nuclei with dopamine origins in the brain, which are also involved in the actions of antipsychotics. Whether antipsychotics can modulate these cellular pathways in the ventral midbrain is unknown. OBJECTIVE: This study aims to investigate the effects of antipsychotics, including aripiprazole (a dopamine D2 receptor (D2R) partial agonist), bifeprunox (a D2R partial agonist), and haloperidol (a D2R antagonist) on the PKA- and GSK3ß-mediated pathways and NMDA receptors in the ventral midbrain. METHODS: Male rats were orally administered aripiprazole (0.75 mg/kg, t.i.d. (ter in die)), bifeprunox (0.8 mg/kg, t.i.d.), haloperidol (0.1 mg/kg, t.i.d.) or vehicle for either 1 week or 10 weeks. The levels of PKA, p-PKA, Akt, p-Akt, GSK3ß, p-GSK3ß, Dvl-3, ß-catenin, and NMDA receptor subunits in the ventral midbrain were assessed by Western Blots. RESULTS: The results showed that chronic antipsychotic treatment with aripiprazole selectively increased PKA activity in the VTA. Additionally, all three drugs elevated the activity of the Akt-GSK3ß signalling pathway in a time-dependent manner, while only aripiprazole stimulated the Dvl-3-GSK3ß-ß-catenin signalling pathway in the SN. Furthermore, chronic administration with both aripiprazole and haloperidol decreased the expression of NMDA receptors. CONCLUSION: This study suggests that activating PKA- and GSK3ß-mediated pathways and downregulating NMDA receptor expression in the ventral midbrain might contribute to the clinical effects of antipsychotics.

OCT4B-190 protects against ischemic stroke by modulating GSK-3ß/HDAC6.

OCT4 is a key regulator in maintaining the pluripotency and self-renewal of embryonic stem cells (ESCs). Human OCT4 gene has three mRNA isoforms, termed OCT4A, OCT4B and OCT4B1. The 190-amino-acid protein isoform (OCT4B-190) is one of the major products of OCT4B mRNA, the biological function of which is still not well defined. Recent evidence suggests that OCT4B-190 may function in the cellular stress response. The glycogen synthase kinase-3ß (GSK-3ß) and histone deacetylase 6 (HDAC6) are also key stress modulators that play critical roles in the ischemic cascades of stroke. Hence, we here further investigated the effects of OCT4B-190 in the experimental stroke, and explored the underlying roles of GSK-3ß and HDAC6. We found that OCT4B-190 overexpression enhanced neuronal viability at 24 h after oxygen-glucose deprivation (OGD) treatment. Moreover, in male C57BL/6 mice subjected to transit middle cerebral artery occlusion (MCAO), OCT4B-190 overexpression reduced infarct volume and improved neurological function after stroke. Notably, we found spatio-temporal alterations of GSK-3ß and HDAC6 in the ischemic cortex and striatum, which were affected by adenovirus-mediated OCT4B-190 overexpression. OCT4B-190 demonstrated similar impacts on neuronal cultures in vitro, downregulating OGD-induced GSK-3ß activity and HDAC6 expression. In addition, we found that GSK-3ß and HDAC6 were co-expressed in the cytoplasm of neurons, and OCT4B-190 had an effect on interactions between GSK-3ß and HDAC6 in neuronal cultures subjected to OGD treatment. These findings suggest that OCT4B-190 exerts neuroprotection in the experimental stroke potentially by regulating actions of GSK-3ß and HDAC6 simultaneously, which may be an attractive therapeutic strategy for ischemic stroke.

Igalan induces detoxifying enzymes mediated by the Nrf2 pathway in HepG2 cells.

Igalan is one of the sesquiterpene lactones found in Inula helenium L., which is used as the traditional medicine to treat inflammatory diseases. However, the pharmacological effects of igalan have not been characterized. In this study, we isolated igalan from I. helenium L. and evaluated the effects of igalan on signaling pathways and expression of target genes in HepG2 cells. Igalan activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway by increasing the inactive form of GSK3ß, the phosphorylated form of AKT, and the nuclear accumulation of Nrf2. Thus, target genes of Nrf2 such as HO-1 and NQO1 increased in HepG2 cells. Moreover, igalan inhibited the tumor necrosis factor-α (TNF-α)-induced nuclear factor-κB activation and suppressed the expression of its target genes, including TNF-α, interleukin (IL)-6, and IL-8 in HepG2 cells. Our results indicate the potential of igalan as an activator of cellular defense mechanisms and a detoxifying agent.

miR-219-5p inhibits tau phosphorylation by targeting TTBK1 and GSK-3ß in Alzheimer's disease.

As the most common neurodegenerative disease, Alzheimer's disease (AD) is characterized by memory, perception, and behavioral damage, which may ultimately lead to emotional fluctuation and even lethal delirium. Increasing studies indicate that microRNAs (miRNAs) are associated with pathological features of AD. However, the role of miR-219-5p in AD progression is still unclear. In this study, the functions of miR-219-5p were analyzed in vitro and in vivo. miR-219-5p was notably overexpressed in brain tissues of patients with AD. The overexpression of miR-219-5p activated the phosphorylation of Tau-Ser198, Tau-Ser199, Tau-Ser201, and Tau-Ser422. We further showed that miR-219-5p could mediate a decrease in the protein levels of tau-tubulin kinase 1 (TTBK1) and glycogen synthase kinase 3ß (GSK-3ß) by directly binding to their 3'-untranslated region, thereby promoting the phosphorylation of tau in SH-SY5Y Cells. Rescue experiments further revealed that the phosphorylation of tau-mediated by miR-219-5p was dependent on the inhibition of TTBK1 and GSK-3ß. Moreover, suppressing the expression of both TTBK1 and GSK-3ß using miR-219-5p remarkably rescued AD-like symptoms in amyloid precursor protein/presenilin 1 mice. Our findings indicate that the upregulation of TTBK1 and GSK-3ß mediated by the loss of miR-219-5p is a possible mechanism that contributes to tau phosphorylation and AD progression.

Effects and mechanism of epigallocatechin-3-gallate on apoptosis and mTOR/AKT/GSK-3ß pathway in substantia nigra neurons in Parkinson rats.

The aim of this study is to investigate the protective effect of epigallocatechin-3-gallate (EGCG) on apoptosis and mTOR/AKT/GSK-3ß pathway in substantia nigra neurons in 6-dopamine-induced Parkinson rats. A total of 30 healthy male SD rats were randomly divided into control group, the Parkinson model group, and Parkinson model+EGCG treatment group. The model and EGCG groups were injected into the right striatum with 6-OHDA to establish the Parkinson model, and the control group was injected with saline only. The EGCG group was intragastrically administered with EGCG 50 mg/kg daily for 4 weeks. The rats' turns, speed, and left forelimb usage; neuron apoptosis by TUNEL; and the α-synuclein protein expression in substantia nigra by immunohistochemical staining were studied. Western blotting was used to detect the relative protein (mTOR, AKT and GSK-3ß) expressions. Compared with the model group, the EGCG group significantly reduced the rotation speed; increased the left forelimb usage (P<0.01); reduced the neuron apoptosis (P<0.01); decreased α-synuclein expression (P<0.01); and decreased the mTOR, AKT, and GSK-3ß protein expressions (P<0.01). EGCG can reduce neuron cell apoptosis in substantia nigra neurons in 6-OHDA-induced Parkinson rats. The mechanism might be related to mTOR/AKT/GSK-3ß activation.

SN56 neuronal cell death after 24 h and 14 days chlorpyrifos exposure through glutamate transmission dysfunction, increase of GSK-3ß enzyme, ß-amyloid and tau protein levels.

Chlorpyrifos (CPF) is an organophosphate insecticide described to induce cognitive disorders, both after acute and repeated administration. However, the mechanisms through which it induces these effects are unknown. CPF has been reported to produce basal forebrain cholinergic neuronal cell death, involved on learning and memory regulation, which could be the cause of such cognitive disorders. Neuronal cell death was partially mediated by oxidative stress generation, P75NTR and α7-nAChRs gene expression alteration triggered through acetylcholinesterase (AChE) variants disruption, suggesting other mechanisms are involved. In this regard, CPF induces Aß and tau proteins production and activation of GSK3ß enzyme and alters glutamatergic transmission, which have been related with basal forebrain cholinergic neuronal cell death and development of cognitive disorders. According to these data, we hypothesized that CPF induces basal forebrain cholinergic neuronal cell death through induction of Aß and tau proteins production, activation of GSK-3ß enzyme and disruption of glutamatergic transmission. We evaluated this hypothesis in septal SN56 basal forebrain cholinergic neurons, after 24 h and 14 days CPF exposure. This study shows that CPF increases glutamate levels, upregulates GSK-3ß gene expression, and increases the production of Aß and phosphorylated tau proteins and all these effects reduced cell viability. CPF increases glutaminase activity and upregulates the VGLUT1 gene expression, which could mediate the disruption of glutamatergic transmission. Our present results provide new understanding of the mechanisms contributing to the harmful effects of CPF, and its possible relevance in the pathogenesis of neurodegenerative diseases.

Glycogen synthase kinase 3ß promotes liver innate immune activation by restraining AMP-activated protein kinase activation.

BACKGROUND & AIMS: Glycogen synthase kinase 3ß (Gsk3ß [Gsk3b]) is a ubiquitously expressed kinase with distinctive functions in different types of cells. Although its roles in regulating innate immune activation and ischaemia and reperfusion injuries (IRIs) have been well documented, the underlying mechanisms remain ambiguous, in part because of the lack of cell-specific tools in vivo. METHODS: We created a myeloid-specific Gsk3b knockout (KO) strain to study the function of Gsk3ß in macrophages in a murine liver partial warm ischaemia model. RESULTS: Compared with controls, myeloid Gsk3b KO mice were protected from IRI, with diminished proinflammatory but enhanced anti-inflammatory immune responses in livers. In bone marrow-derived macrophages, Gsk3ß deficiency resulted in an early reduction of Tnf gene transcription but sustained increase of Il10 gene transcription on Toll-like receptor 4 stimulation in vitro. These effects were associated with enhanced AMP-activated protein kinase (AMPK) activation, which led to an accelerated and higher level of induction of the novel innate immune negative regulator small heterodimer partner (SHP [Nr0b2]). The regulatory function of Gsk3ß on AMPK activation and SHP induction was confirmed in wild-type bone marrow-derived macrophages with a Gsk3 inhibitor. Furthermore, we found that this immune regulatory mechanism was independent of Gsk3ß Ser9 phosphorylation and the phosphoinositide 3-kinase-Akt signalling pathway. In vivo, myeloid Gsk3ß deficiency facilitated SHP upregulation by ischaemia-reperfusion in liver macrophages. Treatment of Gsk3b KO mice with either AMPK inhibitor or SHP small interfering RNA before the onset of liver ischaemia restored liver proinflammatory immune activation and IRI in these otherwise protected hosts. Additionally, pharmacological activation of AMPK protected wild-type mice from liver IRI, with reduced proinflammatory immune activation. Inhibition of the AMPK-SHP pathway by liver ischaemia was demonstrated in tumour resection patients. CONCLUSIONS: Gsk3ß promotes innate proinflammatory immune activation by restraining AMPK activation. LAY SUMMARY: Glycogen synthase kinase 3ß promotes macrophage inflammatory activation by inhibiting the immune regulatory signalling of AMP-activated protein kinase and the induction of small heterodimer partner. Therefore, therapeutic targeting of glycogen synthase kinase 3ß enhances innate immune regulation and protects liver from ischaemia and reperfusion injury.

Rifampicin Prevents SH-SY5Y Cells from Rotenone-Induced Apoptosis via the PI3K/Akt/GSK-3ß/CREB Signaling Pathway.

In addition to its original application for treating tuberculosis, rifampicin has multiple potential neuroprotective effects in chronic neurodegenerative diseases including Parkinson's disease (PD) and Alzheimer's disease. Inflammatory reactions and the PI3K/Akt pathway are strongly implicated in dopaminergic neuronal death in PD. This study aims to investigate whether rifampicin protects rotenone-lesioned SH-SY5Y cells via regulating PI3K/Akt/GSK-3ß/CREB pathway. Rotenone-treated SH-SY5Y cells were used as the cell model to investigate the neuroprotective effects of rifampicin. Cell viability and apoptosis of SH-SY5Y cells were determined by CCK-8 assay and flow cytometry, respectively. The expression of Akt, p-Akt, GSK-3ß, p-GSK-3ß, CREB and p-CREB were measured by Western blot. Our results showed that the cell viability and level of phospho-CREB significantly decreased in SH-SY5Y cells exposed to rotenone when compared to the control group. Both the cell viability and the expression of phospho-CREB in cells pretreated with rifampicin were higher than those of cells exposed to rotenone alone. Moreover, pretreatment of SH-SY5Y cells with rifampicin enhanced phosphorylation of Akt and suppressed activity of GSK-3ß. The addition of LY294002, a PI3K inhibitor, could suppress phosphorylation of Akt and CREB and activate GSK-3ß, resulting in abolishment of neuroprotective effects of rifampicin on cells exposed to rotenone. Rifampicin provides neuroprotection against dopaminergic degeneration, partially via the PI3K/Akt/GSK-3ß/CREB signaling pathway. These findings suggest that rifampicin could be an effective and promising neuroprotective candidate for treating PD.

MicroRNA-940 Targets INPP4A or GSK3ß and Activates the Wnt/ß-Catenin Pathway to Regulate the Malignant Behavior of Bladder Cancer Cells.

In this report, we aimed to explore the role and regulatory mechanism of microRNA-940 (miR-940) in bladder cancer development. The expressions of miR-940 in bladder cancer tissues and cells were measured. miR-940 mimics, miR-940 inhibitor small interference RNA against INPP4A (si-INPP4A), and GSK3ß (si-GSK3ß) and their corresponding controls were then transfected into cells. We investigated the effects of miR-940, INPP4A, or GSK3ß on cell proliferation, migration, invasion, and apoptosis. Additionally, target prediction and luciferase reporter assays were performed to investigate the targets of miR-940. The regulatory relationship between miR-940 and the Wnt/ß-catenin pathway was also investigated. miR-940 was upregulated in bladder cancer tissues and cells. Overexpression of miR-940 significantly increased bladder cancer cell proliferation, promoted migration and invasion, and inhibited cell apoptosis. INPP4A and GSK3ß were the direct targets of miR-940, and knockdown of INPP4A or GSK3ß significantly increased cancer cell proliferation, migration, and invasion and inhibited cell apoptosis. After miR-940 overexpression, the protein expression levels of c-Myc, cyclin D1, and ß-catenin were significantly increased, and the expression levels of p27 and p-ß-catenin were markedly decreased. The opposite effects were obtained after suppression of miR-940. XAV939, a tankyrase 1 inhibitor that could inhibit Wnt/ß-catenin signaling, significantly reversed the effects of miR-940 overexpression on cell migration and invasion. Our results indicate that overexpression of miR-940 may promote bladder cancer cell proliferation, migration, and invasion and inhibit cell apoptosis via targeting INPP4A or GSK3ß and activating the Wnt/ß-catenin pathway. Our findings imply the key roles of suppressing miRNA-940 in the therapy of bladder cancer.

Silencing of Glut1 induces chemoresistance via modulation of Akt/GSK-3ß/ß-catenin/survivin signaling pathway in breast cancer cells.

Cancer cells require increased aerobic glycolysis to support rapid cell proliferation. For their increased energy demands, cancer cells express glucose transporter (Glut) proteins at a high level. Glut1 is associated with basal-like breast cancer and is considered a potential therapeutic target. To investigate the possibility of Glut1 as a therapeutic target in breast cancer cells, we downregulated Glut1 in triple-negative breast cancer (TNBC) cell lines using a short hairpin system. We determined whether Glut1 silencing might enhance anti-proliferative effect of chemotherapeutic agents. Contrary to our hypothesis, ablation of Glut1 attenuated apoptosis and increased drug resistance via upregulation of p-Akt/p-GSK-3ß (Ser9)/ß-catenin/survivin. These results indicated that the potential of Glut1 as a therapeutic target should be carefully reevaluated.

The Wnt/ß-catenin and PI3K/Akt signaling pathways promote EMT in gastric cancer by epigenetic regulation via H3 lysine 27 acetylation.

In this study, we investigated the underlying mechanism of the phosphoinositide 3-kinase/Akt- and Wnt/ß-catenin-mediated promotion of epithelial-to-mesenchymal transition by epigenetic regulation of histone acetylation in gastric cancer. First, we used immunohistochemistry to detect the expression of phosphorylated Akt, phosphorylated glycogen synthase kinase 3 beta, and ß-catenin in gastric cancer tissues and adjacent tissues. In addition, we confirmed that the phosphoinositide 3-kinase/Akt and Wnt/ß-catenin signaling pathways were correlated with tumorigenesis, progression, and maintenance of gastric cancer using the phosphoinositide 3-kinase inhibitor LY294002 and an inhibitor of the ß-catenin/TCF4 complex, FH535. Epithelial-to-mesenchymal transition-related gene expression was measured by western blotting and quantitative real-time polymerase chain reaction assays. Furthermore, we detected the acetylation of histone H3 lysine 4 and lysine 27 using the FH535 and LY294002 inhibitors at different concentrations for 24 and 48 h. Finally, chromatin immunoprecipitation-quantitative polymerase chain reaction was performed to detect the specific binding of H3K27ac to the promoter of the epithelial-to-mesenchymal transition-related factor, Twist. Taken together, abnormal activation of the phosphoinositide 3-kinase/Akt and Wnt/ß-catenin signaling pathway was correlated with the gastric cancer progression and contributed to epithelial-to-mesenchymal transition regulation by controlling histone acetylation.

Icariin protects against glucocorticoid induced osteoporosis, increases the expression of the bone enhancer DEC1 and modulates the PI3K/Akt/GSK3ß/ß-catenin integrated signaling pathway.

Osteoporosis is a serious public health concern worldwide. Herba epimedii has been used for centuries and even thousands of years to treat osteoporotic conditions. Icariin, a flavonol glycoside, is one of the major active ingredients. In this study, we have shown that icariin protected against glucocorticoid-induced osteoporotic changes in SaoS-2 cells and mice. We have also shown that dexamethasone (a glucocorticoid) suppressed and icariin induced DEC1, a structurally distinct helix-loop-helix protein. DEC1 overexpression promoted whereas DEC1 knockdown decreased osteogenic activity. Likewise, DEC1 overexpression and knockdown inversely regulated the expression of ß-catenin and PIK3CA, an essential player in the Wnt/ß-catenin and PI3K/Akt signaling pathways, respectively. Interestingly, DKK1, an inhibitor of Wnt/ß-catenin signaling inhibitor, and LY294002, an inhibitor of PI3K/Akt signaling, abolished the induction of DEC1 by icariin. It is established that these two pathways are interconnected by the phosphorylation status of GSK3ß. Dexamethasone decreased but icariin increased GSK3ß phosphorylation. Finally, DEC1 deficient mice developed osteoporotic phenotypes. Taken together, it is concluded that DEC1 likely supports the action of icariin against glucocorticoid induced osteoporosis with an involvement of the PI3K/Akt/GSK3ß/ß-catenin integrated signaling pathway.

MiR-410 induces stemness by inhibiting Gsk3ß but upregulating ß-catenin in non-small cells lung cancer.

Our previous research indicated miR-410 played a critical role in promoting the tumorigenesis and development of NSCLC (non-small cells lung cancer). MiR-410 has been recently reported to be crucial for development and differentiation of embryonic stem cells. But it remains elusive whether miR-410 stimulates the stemness of cancer until now. Herein, we identify miR-410 induces the stemness and is associated with the progression of NSCLC. We demonstrate miR-410 increases the levels of stem cells marker Sox2, Oct4, Nanog, CXCR4 as well as lung cancer stem cells surface marker CD44 and CD166. MiR-410 promotes stem cells-like properties such as proliferation, sphere formation, metastasis and chemoresistance. Moreover, Gsk3ß is directly targeted and post-transcriptionally downregulated by miR-410. Also, the expression levels of miR-410 and Gsk3ß may be correlated to clinicopathological differentiation in NSCLC tumor specimens. Additionally, we demonstrate miR-410 induces stemness through inhibiting Gsk3ß but increasing Sox2, Oct4, Nanog and CXCR4, which binds to ß-catenin signaling. In conclusion, our findings identify the miR-410/Gsk3ß/ß-catenin signaling axis is a novel molecular circuit in inducing stemness of NSCLC.

Possible role of HIWI2 in modulating tight junction proteins in retinal pigment epithelial cells through Akt signaling pathway.

PIWI subfamily of proteins is shown to be primarily expressed in germline cells. They maintain the genomic integrity by silencing the transposable elements. Although the role of PIWI proteins in germ cells has been documented, their presence and function in somatic cells remains unclear. Intriguingly, we detected all four members of PIWI-like proteins in human ocular tissues and somatic cell lines. When HIWI2 was knocked down in retinal pigment epithelial cells, the typical honeycomb morphology was affected. Further analysis showed that the expression of tight junction (TJ) proteins, CLDN1, and TJP1 were altered in HIWI2 knockdown. Moreover, confocal imaging revealed disrupted TJP1 assembly at the TJ. Previous studies report the role of GSK3ß in regulating TJ proteins. Accordingly, phospho-kinase proteome profiler array indicated increased phosphorylation of Akt and GSK3α/ß in HIWI2 knockdown, suggesting that HIWI2 might affect TJ proteins through Akt-GSK3α/ß signaling axis. Moreover, treating the HIWI2 knockdown cells with wortmannin increased the levels of TJP1 and CLDN1. Taken together, our study demonstrates the presence of PIWI-like proteins in somatic cells and the possible role of HIWI2 in preserving the functional integrity of epithelial cells probably by modulating the phosphorylation status of Akt.