Phosphoinositide 3-kinase Akt Research Articles

Food intake in early life and epigenetic modifications of pro-opiomelanocortin expression in arcuate nucleus.

The prevalence of obesity is increasing in nowadays societies and, despite being a multifactorial disease, it has a significant correlation with food intake. The control of food intake is performed by neurons of the arcuate nucleus of the hypothalamus (ARC), which secret orexigenic and anorexigenic neuropeptides, such as proopiomelanocortin (POMC), under stimulation of, e.g., ghrelin, insulin, and leptin. Insulin, uses inositol 1,4,5-trisphosphate/serine-threonine kinase (IP3/Akt) pathways and stimulates the exclusion of (Forkhead box protein O1) FOXO1 from the nucleus and thereby does the inactivation of the inhibition of POMC expression, while Leptin stimulates signal transducer and activator of transcription 3 (STAT3) phosphorylation and POMC expression. Epigenetic modifications of the synthesis of these neuropeptides can lead to an increased caloric intake, which, in turn, is an important risk factor for obesity and its comorbidities. Epigenetic modifications are reversible, so the search for epigenetic targets has significant scientific and therapeutic appeal. In this review, we synthesize the effect of food intake on the epigenetic modifications of Neuropeptide Y and Pro-opiomelanocortin of ARC and its relationships with obesity development and comorbidities. We found that there is no consensus on the methylation of neuropeptides when the evaluations are carried out in different promoters. Based on reports carried on in the early life in laboratory animals, which is the timeline that the vast majority of author used to study this topic, chronic inflammation, defects in insulin and leptin signaling may be linked to changes occurring in the phosphoinositide 3-kinase/Akt (PI3K/Akt) and/or STAT3/SOCS3(cytokine signaling 3) pathways. In its turn, the epigenetic modifications related to increased food intake and reduced energy expenditure may be associated with PI3K/Akt and STAT3/SOCS3 signaling disruption and Pro-opiomelanocortin expression.

The signaling pathway PI3K/Akt/Nrf2/HO-1 plays a role in the mitochondrial protection promoted by astaxanthin in the SH-SY5Y cells exposed to hydrogen peroxide

The mitochondria are the major source of reactive species in the mammalian cells. Hydrogen peroxide (H2O2) is a potent inducer of redox impairment by a mechanism, at least in part, dependent on its ability to impair mitochondrial function. H2O2 plays an important role in several pathological conditions, including neurodegeneration and cardiovascular diseases. Astaxanthin (AST) is a xanthophyll that may be found in microalgae, crustaceans, and salmon and exhibits antioxidant and anti-inflammatory effects in different cell types. Even though there is evidence pointing to a role for AST as mitochondrial protectant agent, it was not clearly demonstrated how this xanthophyll attenuates mitochondrial stress. Therefore, we investigated here whether and how AST would be able to prevent the H2O2-induced mitochondrial dysfunction in the human neuroblastoma SH-SY5Y cells. We found that AST (20 μM) prevented the H2O2-induced loss of mitochondrial membrane potential (MMP) and decrease in the activity of the Complexes I and V. AST pretreatment blocked the mitochondria-related pro-apoptotic effects elicited by H2O2. AST upregulated the enzyme heme oxygenase-1 (HO-1) and the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) by a mechanism dependent on the phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathway. Inhibition of the PI3K/Akt or of the HO-1 enzyme abolished the AST-induced mitochondrial protection in cells challenged with H2O2. Silencing of Nrf2 caused similar effects. Thus, we suggest that AST promotes mitochondrial protection by a mechanism dependent on the PI3K/Akt/Nrf2/HO-1 signaling pathway in SH-SY5Y cells exposed to H2O2.

Pharmacological Effects of Agastache rugosa against Gastritis Using a Network Pharmacology Approach.

Agastache rugosa is used as a Korean traditional medicine to treat gastric diseases. However, the active ingredients and pharmacological targets of A. rugosa are unknown. In this study, we aimed to reveal the pharmacological effects of A. rugosa on gastritis by combining a mice model and a network pharmacology method. The macrophage and gastritis-induced models were used to evaluate the pharmacological effects of A. rugosa. The results show that A. rugosa relieved mucosal damage induced by HCl/EtOH in vivo. Network analysis identified 99 components in A. rugosa; six components were selected through systematic screening, and five components were linked to 45 gastritis-related genes. The main components were acacetin and luteolin, and the identified core genes were AKT serine/threonine kinase 1 (AKT1), nuclear factor kappa B inhibitor alpha (NFKBIA), and mitogen-activated protein kinase-3 (MAPK3) etc. in this network. The network of components, target genes, protein–protein interactions, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway was closely connected with chemokines and with phosphoinositide 3-kinase-Akt (PI3K/AKT), tumor-necrosis-factor alpha (TNFα), mitogen-activated protein kinase, nuclear factor kappa B, and Toll-like receptor (TLR) pathways. In conclusion, A. rugosa exerts gastro-protective effects through a multi-compound and multi-pathway regulatory network and holds potential for treating inflammatory gastric diseases.

Microglia induce the transformation of A1/A2 reactive astrocytes via the CXCR7/PI3K/Akt pathway in chronic post-surgical pain

BackgroundActivated astrocytes play important roles in chronic post-surgical pain (CPSP). Recent studies have shown reactive astrocytes are classified into A1 and A2 phenotypes, but their precise roles in CPSP remain unknown. In this study, we investigated the roles of spinal cord A1 and A2 astrocytes and related mechanisms in CPSP.MethodsWe used a skin/muscle incision and retraction (SMIR) model to establish a rat CPSP model. Microglia, CXCR7, and the phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathways were regulated by intrathecal injections of minocycline (a non-specific microglial inhibitor), AMD3100 (a CXCR7 agonist), and LY294002 (a specific PI3K inhibitor), respectively. Mechanical allodynia was detected with von Frey filaments. The changes in microglia, A1 astrocytes, A2 astrocytes, CXCR7, and PI3K/Akt signaling pathways were examined by enzyme-linked immunosorbent assay (ELISA), western blot, and immunofluorescence.ResultsMicroglia were found to be activated, with an increase in interleukin-1 alpha (IL-1α), tumor necrosis factor alpha (TNFα), and complement component 1q (C1q) in the spinal cord at an early stage after SMIR. On day 14 after SMIR, spinal cord astrocytes were also activated; these were mainly of the A1 phenotype and less of the A2 phenotype. Intrathecal injection of minocycline relieved SMIR-induced mechanical allodynia and reverted the ratio of A1/A2 reactive astrocytes. The expression of CXCR7 and PI3K/Akt signaling was decreased after SMIR, while they were increased after treatment with minocycline. Furthermore, intrathecal injection of AMD3100 also relieved SMIR-induced mechanical allodynia, reverted the ratio of A1/A2 reactive astrocytes, and activated the PI3K/Akt signaling pathway, similar to the effects produced by minocycline. However, intrathecal injection of AMD3100 did not increase the analgesic effect of minocycline. Last, LY294002 inhibited the analgesic effect and A1/A2 transformation induced by minocycline and AMD3100 after SMIR.ConclusionOur results indicated that microglia induce the transformation of astrocytes to the A1 phenotype in the spinal cord via downregulation of the CXCR7/PI3K/Akt signaling pathway during CPSP. Reverting A1 reactive astrocytes to A2 may represent a new strategy for preventing CPSP.

Role of 2-Arachidonoyl-Glycerol and CB1 Receptors in Orexin-A-Mediated Prevention of Oxygen-Glucose Deprivation-Induced Neuronal Injury.

Orexin-A (OX-A) protects the brain against oxidative stress-mediated ischemic injury. Since the endocannabinoid 2-arachidonoylglycerol (2-AG) and cannabinoid type-1 (CB1) receptors were previously shown to mediate some of the effects of OX-A exerted through the orexin-1 receptor (OX-1R), we investigated the involvement of 2-AG in OX-A-induced neuroprotection following oxygen and glucose deprivation (OGD) in mouse cortical neurons. OGD-induced reactive oxygen species (ROS) accumulation and neuronal death were prevented by both OX-A and arachidonyl-2′-chloroethylamide (ACEA), a synthetic CB1 receptor agonist, in a manner sensitive to OX-1R and CB1 receptor antagonists, SB334867 and AM251. OX-A stimulated 2-AG biosynthesis in cortical neurons. In neurons isolated from monoacylglycerol lipase (MAGL, a 2-AG hydrolyzing enzyme) null mice, 10-fold higher 2-AG concentrations were found and OGD failed to induce ROS production and cell death, whereas AM251 restored these noxious effects. OX-A-induced neuroprotection was mediated by the phosphoinositide-3-kinase/Akt (PI3K/Akt) survival pathway since both OX-A and ACEA induced phosphorylation of Akt and prevented OGD-induced cytochrome c release from the mitochondria, in a manner counteracted by SB334867 or AM251. Administration of OX-A reduced infarct volume and elevated brain 2-AG levels in a mouse model of transient ischemia. These results suggest that 2-AG and CB1 receptor mediate OX-A prevention of ischemia-induced neuronal apoptosis.

Network pharmacology-based strategy to investigate pharmacological mechanisms of Tinospora sinensis for treatment of Alzheimer's disease

Ethnopharmacological relevanceTinospora sinensis (Lour.) Merr. belongs to the family Menispermaceae. It is called LeZhe and is widely used as a kind of folk medicine especially in the Tibetan Plateau of China. T. sinensis has the functions of clearing away heat and detoxification, dispelling wind and dredging collaterals, calming and soothing the nerves. T. sinensis is an effective medicine for the prevention and treatment of aging diseases such as Alzheimer's disease (AD) in the Tibetan Plateau of China, whereas its material basis and underlying mechanisms are not clear. The aim of this study was to investigate the material basis and potential mechanisms of T. sinensis in the treatment of AD by using network pharmacology and molecular docking. Materials and methodsIn this study, targets were collected from DrugBank database, Therapeutic Target Database (TTD) and literatures reports for the treatment of AD. Compounds were searched by literatures and systematic separation from T. sinensis. The molecular docking experiment was carried out by using Autodock Vina software to screen the bioactive compounds in T. sinensis and target proteins for AD. Then, the “compound-target network” was constructed by Cytoscape software. The drug-like properties of the active compounds were analyzed by pKCSM performs, and the protein-protein interaction (PPI) network was constructed by Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). The Kyoto Encyclopedia of Genes and Genomes (KEGG) target pathway enrichment analysis was carried out by Database for Annotation, Visualization and Integrated Discovery (DAVID). Furthermore, the protective effect of neurons of two active compounds were verified with the injury cell model of PC12 and primary hippocampus neurons induced by Aβ25-35. Finally, the key proteins of related pathways were quantitatively analyzed with Western blot method. ResultsIn total, 105 compounds and 38 targets have been screened. The main active compounds contained berberine, which belongs to alkaloids, Aurantiamide acetate, N–P-coumaroyltyramine, which belongs to amides, Trans-syringin and 3-demethyl-phillyrin, which belongs to phenylpropanoids. The targets covered inflammation-related proteins, including Protein kinase B (AKT), Phosphoinositide 3-kinase (PI3K), Tyrosine-protein kinase JAK1 (JAK1), mammalian target of rapamycin (mTOR), tumor necrosis factor alpha (TNF-α), Neuronal NOS (NOS1), and cholinergic function-related proteins, including α4-Nicotinic acetylcholine receptor (α4 nAChR), Muscarinic acetylcholine receptor M1 (Muscarnic M1). Inflammation and cholinergic dysfunction were the center of the network and occupy a dominant position. And the results of enrichment analysis shown the pathways mainly contained phosphoinositide-3-kinase/Akt (PI3K/Akt) signal pathway, neurotrophic factors (NTFs) signal pathway, Hypoxia-inducible factor 1 (HIF-1) signal pathway, mechanistic Target of Rapamycin (mTOR) signal pathway, Tumor necrosis factor (TNF) signal pathway, insulin resistance (IR). The results of in vitro assays showed that the tested compounds could significantly improve the survival rate and inhibit the apoptosis of PC12 cells and primary hippocampal neurons injured by Aβ25-35. Western blot results showed that T. sinensis had a significant effect on the expression of protein PI3K and Akt. Conclusion: Our results revealed that T. sinensis could prevent and treat AD through a multi-compound-multi-target-multi-pathway regulatory network. Our work also expected to provide new ideas and theoretical bases for searching for the active compounds in T. sinensis and potential mechanism in the prevention and treatment of AD by the network pharmacology and molecular docking. The results of in vitro assay and in vivo assay supported the results of molecular docking.

Effect of X-rays on transcript expression of rat brain microvascular endothelial cells: role of calcium signaling in X-ray-induced endothelium damage.

Radiation-induced brain edema is a serious adverse effect of radiotherapy. Although there are many causes of radiation-induced brain edema, the pathogenesis is not clear and clinical treatment is not ideal. Therefore, knowing the differential expression of the brain microvascular endothelial cell (BMEC) transcriptome after brain radiotherapy may shed light on the pathogenesis of radiation-induced brain edema. The present study used RNA-Seq technique to identify 383 BMEC transcripts differentially expressed (many 2-fold or higher; P < 0.05) between control and X-ray–treated primary cultured rat BMECs. Compared with controls, X-ray–treated BMECs had 183 significantly up-regulated transcripts and 200 significantly down-regulated transcripts. The differentially expressed genes were associated with the biological processes of the cell cycle, apoptosis, vascular permeability, and extracellular junctions. The functional changes identified in the X-ray–treated BMECs included Ca2+ signaling, phosphoinositide 3-kinase–Akt signaling, and methionine degradation. These results indicated that transcript expression was substantially affected by radiation exposure and the proteins encoded by these differentially expressed genes may play a significant role in radiotherapy-induced brain edema. Our findings provide additional insight into the molecular mechanisms of radiation-induced brain edema and may be helpful in the development of clinical treatment of this adverse reaction to radiotherapy.

Anti-inflammatory Effect of d-(+)-Cycloserine Through Inhibition of NF-κB and MAPK Signaling Pathways in LPS-Induced RAW 264.7 Macrophages

Recently, additional therapeutic potentials of classical antibiotics are gaining considerable attention. The discovery of penicillin in the 1920s had a major impact on the history of human health. Penicillin has been used for the treatment for fatal microbial infections in humans and has led to the discovery of several new antibiotics. d-(+)-Cycloserine (DCS) is an antibiotic isolated from Streptomyces orchidaceous and is used in conjunction with other drugs in the treatment of tuberculosis. However, there have been no studies on the anti-inflammatory effects of DCS in RAW 264.7 macrophage cell line. To investigate the anti-inflammatory effects of DCS, we examined the ability of DCS to inhibit the inflammatory responses in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages in this study. Cell viability was analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cells were pretreated with various concentrations (2, 4, and 6 mM) of DCS, then treated with 1 μg/mL LPS to detect its anti-inflammatory effects. d-(+)-Cycloserine inhibited the production of nitric oxide (NO) in a concentration-dependent manner, and to some extent, inhibited the production of prostaglandin E2. Consistent with these findings, DCS suppressed the expression of pro-inflammatory cytokines such as interleukin (IL)-1β and IL-6. However, it had no effect on the expression of tumor necrosis factor-α. Western blot analysis demonstrated that DCS inhibited inducible nitric oxide synthase and suppressed cyclooxygenase type-2 (COX-2) expression. In addition, investigation of its effects on nuclear factor kappa B signaling showed that DCS inhibited phosphorylation of inhibitory kappa B-α (IκB-α) and increased intracellular IκB-α in a concentration-dependent manner. Furthermore, DCS inhibited the phosphorylation of LPS-induced extracellular signal-regulated kinase, however it did not affect phosphorylation of c-jun N-terminal kinase and p38. Further studies confirmed that the inhibition of phosphorylation of IκB-α was mediated through the inhibition of phosphoinositide 3-kinase/Akt (PI3K/Akt) pathway. To determine the applicability of DCS to the skin, cytotoxicity on HaCaT keratinocytes was measured following treatment with various concentrations (2, 4, 6, 8, and 10 mM) of DCS using MTT assay. These results suggest that DCS may be used as a potential drug for the treatment of inflammatory diseases.

Role of fucosyltransferase IV in the migration and invasion of human melanoma cells.

Malignant melanoma is one of the most aggressive human tumor types, mainly due to its high invasion capability, metastatic properties, and the absence of effective treatments. Glycosylation serves a pivotal role in the migration and invasion of melanoma. However, differences in glycosylation between high and low metastatic melanoma cells and how these regulate migration and invasion by altering the expression of fucosyltransferases (FUTs) remain unclear. In the present study, matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) analysis revealed that the composition profiling of fucosylated N-glycans differed between high metastatic C8161 and low metastatic A375P cells. Further analysis revealed that FUT4 expression was significantly increased in C8161 cells. Melanoma tissue arrays further demonstrated that FUT4 was overexpressed in metastatic samples. Altered FUT4 expression was accompanied by a change in the migration and invasion capacity of the cells. In addition, the migration and invasion potential of melanoma cells were decreased in C8161 and increased in A375P cells upon altering FUT4 expression levels by small interfering RNA or complementary DNA transfection. Furthermore, regulating FUT4 expression markedly modulated the activity of the phosphoinositide-3-kinase/Akt (PI3K/Akt) signaling pathway, which affected melanoma cell migration and invasion. In conclusion, FUT4 is a novel biomarker and regulator of the migration and invasion of melanoma cells and may serve as a therapeutic target for melanoma.

A Radiosensitivity Gene Signature and PD-L1 Status Predict Clinical Outcome of Patients with Glioblastoma Multiforme in The Cancer Genome Atlas Dataset.

PurposeCombination of radiotherapy and immune checkpoint blockade such as programmed death-1 (PD-1) or programmed death-ligand 1 (PD-L1) blockade is being actively tested in clinical trial. We aimed to identify a subset of patients that could potentially benefit from this strategy using The Cancer Genome Atlas (TCGA) dataset for glioblastoma (GBM).Materials and MethodsA total of 399 cases were clustered into radiosensitive versus radioresistant (RR) groups based on a radiosensitivity gene signature and were also stratified as PD-L1 high versus PD-L1 low groups by expression of CD274 mRNA. Differential and integrated analyses with expression and methylation data were performed. CIBERSORT was used to enumerate the immune repertoire that resulted from transcriptome profiles.ResultsWe identified a subset of GBM, PD-L1-high-RR group which showed worse survival compared to others. In PD-L1-high-RR, differentially expressed genes (DEG) were highly enriched for immune response and mapped into activation of phosphoinositide 3-kinase–AKT and mitogen-activated protein kinase (MAPK) signaling pathways. Integration of DEG and differentially methylated region identified that the kinase MAP3K8-involved in T-cell receptor signaling was upregulated and BAI1, a factor which inhibits angiogenesis, was silenced. CIBERSORT showed that a higher infiltration of the immune repertoire, which included M2 macrophages and regulatory T cells.ConclusionTaken together, PD-L1-high-RR group could potentially benefit from radiotherapy combined with PD-1/PD-L1 blockade and angiogenesis inhibition.

The PI3K-AKT network at the interface of oncogenic signalling and cancer metabolism.

The altered metabolic programme of cancer cells facilitates their cell-autonomous proliferation and survival. In normal cells, signal transduction pathways control core cellular functions, including metabolism, to couple the signals from exogenous growth factors, cytokines or hormones to adaptive changes in cell physiology. The ubiquitous, growth factor-regulated phosphoinositide 3-kinase (PI3K)-AKT signalling network has diverse downstream effects on cellular metabolism, through either direct regulation of nutrient transporters and metabolic enzymes or the control of transcription factors that regulate the expression of key components of metabolic pathways. Aberrant activation of this signalling network is one of the most frequent events in human cancer and serves to disconnect the control of cell growth, survival and metabolism from exogenous growth stimuli. Here we discuss our current understanding of the molecular events controlling cellular metabolism downstream of PI3K and AKT and of how these events couple two major hallmarks of cancer: growth factor independence through oncogenic signalling and metabolic reprogramming to support cell survival and proliferation.

Effect of landiolol on sex-related transcriptomic changes in the myocardium during sepsis

ObjectivesThe aims of this study are to better understand phenotypic differences between male and female rats during sepsis, to characterise the contribution of the beta1-adrenergic blocker landiolol to septic cardiomyopathy and to determine why landiolol induces divergent effects in males and females.MethodsThe myocardial transcriptional profiles in male and female Wistar rats were assessed after the induction of sepsis by cecal ligation and puncture and addition of landiolol.ResultsOur results showed major differences in the biological processes activated during sepsis in male and female rats. In particular, a significant decrease in processes related to cell organisation, contractile function, ionic transport and phosphoinositide-3-kinase/AKT (PI3K/AKT) signalling was observed only in males. The transcript of ATPase sarcoplasmic/endoplasmic reticulum Ca2+ transporting 3 (SERCA3) was sex-differently regulated. In males, landiolol reversed several signalling pathways dysregulated during sepsis. The expression level of genes encoding tubulin alpha 8 (TUBA8) and myosin heavy chain 7B (MYH7) contractile proteins, phosphatase 2 catalytic subunit alpha (PPP2CA), G protein-coupled receptor kinase 5 (GRK5) and A-kinase anchoring protein 6 (AKAP6) returned to their basal levels. In contrast, in females, landiolol had limited effects.ConclusionIn males, landiolol reversed the expression of many genes that were deregulated in sepsis. Conversely, sepsis-induced deregulation of gene expression was less pronounced in females than in males, and was maintained in the landiolol-treated females. These findings highlight important sex-related differences and confirm previous observations on the important benefit of landiolol intake on cardiac function in male rats.

The effects of kahweol, a diterpene present in coffee, on the mitochondria of the human neuroblastoma SH-SY5Y cells exposed to hydrogen peroxide

The oxidative phosphorylation (OXPHOS) system located in the mitochondria is the main source of adenosine triphosphate (ATP) in mammals. The mitochondria are also the main site of reactive oxygen species (ROS) production in those cells. Disruption of the mitochondrial redox biology has been seen in the onset and progression of neurodegenerative diseases. In this regard, we have tested here whether kahweol (KW; C20H26O3), a diterpene present in coffee, would be able to promote mitochondrial protection in the human neuroblastoma SH-SY5Y cells exposed to hydrogen peroxide (H2O2). A pretreatment (for 12 h) with KW (at 10 μM) decreased the impact of H2O2 (at 300 μM) on the levels of oxidative stress markers in the mitochondrial membranes, as well as reduced the production of ROS by the organelles. KW pretreatment also suppressed the effects of H2O2 on the activity of components of the OXPHOS. The KW-induced mitochondria-related effects were blocked by inhibition of the phosphoinositide 3-kinase/Akt (PI3K/Akt) and p38 mitogen-activated protein kinase (MAPK) signaling pathways. Furthermore, silencing of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and inhibition of the heme oxygenase-1 (HO-1) enzyme abrogated the KW-induced protective effects on the mitochondria. Therefore, KW promoted mitochondrial protection by the PI3K/Akt and p38 MAPK/Nrf2/HO-1 axis in H2O2-challenged SH-SY5Y cells.

Effect of Furostanol Saponins from Allium Macrostemon Bunge Bulbs on Platelet Aggregation Rate and PI3K/Akt Pathway in the Rat Model of Coronary Heart Disease.

Aim. To investigate the effect of Furostanol Saponins from Allium Macrostemon Bunge Bulbs (FSAMB) on platelet aggregation rate of rats with coronary heart disease and discuss the mechanism of FSAMB affecting the platelet aggregation rate through PI3K/Akt pathway. We established the rat models with coronary heart disease (CHD) and prepared the platelet-rich plasma. The effect of different concentrations of FSAMB on platelet aggregation in SD rats induced by ADP was observed in vitro and in vivo. And Lactate Dehydrogenase (LDH), Creatine Kinase-MB Form (CK-MB), and Cardiac Troponin I (cTnI) are detected in the blood to know the level of damage to heart cells. The expansion of platelets in the immobilized fibrinogen in different concentrations of FSAMB was observed. Western blot was conducted to detect the phosphorylation level of protein kinase B (also known as Akt) and the expression level of phosphoinositide 3-kinase (PI3K). We found that FSAMB had a significant inhibitory effect on the ADP-induced platelet aggregation in vitro. Intragastric administration of FSAMB also inhibited platelet aggregation induced by ADP in rats. LDH, CK-MB, and cTnI levels in serum of rats in FSAMB (672 mg/kg) group were lower than those in the model control group after the intervention (P<0.01 or P<0.05). FSAMB inhibited the expansion of platelets on immobilized fibrinogen. Also, FSAMB inhibited ADP-induced platelet PI3K expression and Akt phosphorylation. The inhibition of Akt phosphorylation by FSAMB was more obvious after the inhibition of the expression of PI3K. This study demonstrated that FSAMB can reduce the degree of myocardial cell damage and inhibit ADP-induced platelet aggregation in SD rats, possibly by inhibiting platelet PI3K/Akt signaling pathway in vitro and in vivo.

Tamibarotene Improves Hippocampus Injury Induced by Focal Cerebral Ischemia-Reperfusion via Modulating PI3K/Akt Pathway in Rats

Goal: The present study aimed to examine whether Am80 (tamibarotene) protects the hippocampus against cerebral ischemia-reperfusion (I/R) injury and whether phosphoinositide-3-kinase/Akt (PI3K/Akt) pathway mediates this effect. Materials and methods: Rats were subjected to 90 minutes of middle cerebral artery occlusion followed by 24 hours of reperfusion. The animals were randomly divided into 7 groups: sham-operated group; I/R group; groups pretreated with 2 mg/kg, 6 mg/kg, and 10 mg/kg of Am80; Am80 (6 mg/kg) combined with the selective PI3K inhibitor wortmannin (0.6 mg/kg), and wortmannin (0.6 mg/kg) only group. After 24 hours of reperfusion, neurological deficits and infarct volume were measured. Pathological changes in hippocampal neurons were analyzed by transmission electron microscopy. Neuronal survival was examined by TUNEL staining. The expression of Bcl-2, Bax, and Akt, and Akt phosphorylation (p-Akt) were measured by Western blotting and quantitative real-time polymerase chain reaction. Findings: The pretreatment with Am80 improved the neurologic deficit score, reduced infarct volume, and decreased the number of TUNEL-positive cells in the hippocampus. Moreover, Am80 pretreatment downregulated the expression of Bax, upregulated the expression of Bcl-2, and increased the level of p-Akt. Wortmannin abolished in part the increase in p-Act and the neuroprotective effect exerted on the ischemic by Am80 pretreatment. Conclusions: Our results documented that Am80 pretreatment protects ischemic hippocampus after cerebral I/R by regulating the expression of apoptosis-related proteins through the activation of the PI3K/Akt signaling pathway.

Panax notoginseng saponins alleviate skeletal muscle insulin resistance by regulating the IRS1-PI3K-AKT signaling pathway and GLUT4 expression.

Panax notoginseng saponins (PNS) are a commonly used traditional medicine to treat diabetes in China. Recent studies have confirmed their anti‐diabetic effects, but the underlying mechanisms have remained unclear. The present study was designed to explore whether PNS decrease hyperglycemia by improving insulin sensitivity in skeletal muscle and to elucidate the molecular mechanisms. The anti‐diabetic effects of PNS were analyzed in a skeletal myoblast cell line, C2C12, and in high fat diet‐induced diabetic KKAy mice. C2C12 cells were treated with PNS (50, 100, and 200 μg·L−1) and examined for glucose uptake, cell viability and expression of components of the phosphoinositide 3‐kinase (PI3K)–protein kinase B (AKT) signaling pathway. KKAy mice were intraperitoneally injected with PNS (200 mg·kg−1) for 6 weeks. Body weight, blood glucose, serum insulin, serum lipid, glucose and insulin tolerance were measured to evaluate the anti‐diabetic effects of PNS. Pathological changes, apoptosis and the PI3K–AKT signaling pathway were analyzed in KKAy skeletal muscle. PNS significantly increased insulin‐induced glucose uptake, but did not affect the cell viability of C2C12 cells. In addition, PNS reduced blood glucose and serum insulin levels and improved glucose tolerance and insulin tolerance of KKAy mice. Pathological changes and apoptosis of skeletal muscle were relieved by PNS treatment. Moreover, PNS treatment enhanced expression of mRNA encoding IRS1 and GLUT4, as well as the protein expression of phosphorylated (p) ‐insulin receptor substrate 1 (IRS1), p‐PI3K, p‐AKT and glucose transporter type 4 (GLUT4) in C2C12 and KKAy mouse muscle. Collectively, these data indicate that PNS reduces hyperglycemia and insulin resistance through up‐regulating GLUT4 expression and the IRS1–PI3K–AKT signaling pathway. Furthermore, PNS alleviated diabetes skeletal muscle pathological damage. Thus, our data suggest that PNS may be promising anti‐diabetic compounds.

Acetylsalicylic Acid Treatment and Suppressive Regulation of AKT Accelerate Odontogenic Differentiation of Stem Cells from the Apical Papilla

IntroductionStem cells isolated from the root apical papilla of human teeth (stem cells from the apical papilla [SCAPs]) are capable of forming tooth root dentin and are a feasible source for bioengineered tooth root regeneration. In this study, we examined the effect of acetylsalicylic acid (ASA) on odontogenic differentiation of SCAPs in vitro and in vivo. MethodsSCAPs were cultured under odontogenic conditions supplemented with or without ASA. ASA-treated SCAPs were also subcutaneously transplanted into immunocompromised mice. ResultsASA accelerates in vitro and in vivo odontogenic differentiation of SCAPs associated with down-regulation of runt-related nuclear factor 2 and up-regulation of specificity protein 7, nuclear factor I C, and dentin phosphoprotein. ASA up-regulated the phosphorylation of AKT in the odontogenic SCAPs. Of interest, pretreatments with phosphoinositide 3-kinase inhibitor LY294402 and small interfering RNA for AKT promoted ASA-induced in vitro and in vivo odontogenic differentiation of SCAPs. LY294402 and small interfering RNA for AKT also suppressed the ASA-induced expression of runt-related nuclear factor 2 and enhanced ASA-induced expression of specificity protein 7, nuclear factor I C, and dentin phosphoprotein in SCAPs. ConclusionsThese findings suggest that a combination of ASA treatment and suppressive regulation of the phosphoinositide 3-kinase–AKT signaling pathway is a novel approach for SCAP-based tooth root regeneration.

Identification of key candidate genes and pathways in oral squamous cell carcinoma by integrated Bioinformatics analysis.

Oral squamous cell carcinoma (OSCC) is one of the most common types of malignant head and neck tumor, which poses a serious threat to human health. In recent years, the incidence of OSCC has been increasing, while the prognosis has not significantly improved. Elucidation of the molecular mechanisms underlying the development of OSCC may provide novel therapeutic strategies. In the present study, the gene expression profiles from 4 datasets, including 244 OSCC and 95 normal oral mucosa samples, were subjected to statistical and Bioinformatics analysis. A total of 34 differentially expressed genes (DEGs) were identified, among which 14 were upregulated and 20 were downregulated in OSCC compared with normal oral mucosa tissues. Gene Ontology enrichment analysis indicated that the DEGs were mainly involved in regulation of the immune response, cell adhesion and cell proliferative processes. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the DEGs were mainly associated with the phosphoinositide-3 kinase Akt and Toll-like receptor signaling pathway. The key candidate DEGs were identified from the complex protein-protein interaction network, and secreted phosphoprotein 1 (SPP1), integrin subunit α 3 and plasminogen activator, urokinase (PLAU) were confirmed to be significantly associated with the survival rate. Cell Counting Kit-8 and Transwell assays demonstrated that SPP1 and PLAU regulate cell proliferation, migration and invasion. The candidate genes/pathways identified in the present study may include promising diagnostic biomarkers or therapeutic targets for OSCC.

Membrane-tethered Notch1 exhibits oncogenic property via activation of EGFR-PI3K-AKT pathway in oral squamous cell carcinoma.

Notch proteins are highly conserved cell surface receptors which play essential roles in cellular differentiation, proliferation, and apoptotic events at all stages of development. Recently, NOTCH1 mutations have been extensively observed in oral squamous cell carcinoma (OSCC) and are hinted to be Notch1-inactivating mutations. However, little is known about the biological effect of these reported mutations in OSCC. To mimic the inactivation of Notch1 due to inappropriate mutations and to determine the potential mechanisms, we utilized wild-type Notch1 vectors (Notch1WT ) or mutant Notch1 vectors (Notch1V1754L ) to transfect into OSCC cell lines. Membrane-tethered Notch1 induced by mutation was analyzed by immunofluorescence staining. γ-Secretase inhibitor PF-03084014 was utilized to determine the phenotype in the absence of endogenous Notch1 activation. Here we demonstrated that membrane-tethered Notch1 inactivated the canonical Notch1 signaling and oncogenic phenotypes were identified by promoting cell proliferation and invasion and by inducing epithelial-to-mesenchymal transition in cells. The γ-secretase inhibitor PF-03084014 also showed distinct oncogenic property after treatment. Importantly, both membrane-tethered Notch1 and PF-03084014 inhibitor activated the epidermal growth factor receptor (EGFR)-phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway, which has been confirmed as an overwhelming modulator in OSCC. This was the first time that we clearly simulated the mutated Notch1 activities and determined the oncogenic phenotypes of membrane-tethered Notch1. Compared with wild-type Notch1, membrane-tethered Notch1 was strongly associated with activated EGFR-PI3K-AKT signaling pathway.

Estrogen Improves Insulin Sensitivity and Suppresses Gluconeogenesis via the Transcription Factor Foxo1.

Premenopausal women exhibit enhanced insulin sensitivity and reduced incidence of type 2 diabetes (T2D) compared with age-matched men, but this advantage disappears after menopause with disrupted glucose homeostasis, in part owing to a reduction in circulating 17β-estradiol (E2). Fasting hyperglycemia is a hallmark of T2D derived largely from dysregulation of hepatic glucose production (HGP), in which Foxo1 plays a central role in the regulation of gluconeogenesis. Here, we investigated the action of E2 on glucose homeostasis in male and ovariectomized (OVX) female control and liver-specific Foxo1 knockout (L-F1KO) mice and sought to understand the mechanism by which E2 regulates gluconeogenesis via an interaction with hepatic Foxo1. In both male and OVX female control mice, subcutaneous E2 implant improved insulin sensitivity and suppressed gluconeogenesis; however, these effects of E2 were abolished in L-F1KO mice of both sexes. In our use of mouse primary hepatocytes, E2 suppressed HGP and gluconeogenesis in hepatocytes from control mice but failed in hepatocytes from L-F1KO mice, suggesting that Foxo1 is required for E2 action on the suppression of gluconeogenesis. We further demonstrated that E2 suppresses hepatic gluconeogenesis through activation of estrogen receptor (ER)α-phosphoinositide 3-kinase-Akt-Foxo1 signaling, which can be independent of insulin receptor substrates 1 and 2 (Irs1 and Irs2), revealing an important mechanism for E2 in the regulation of glucose homeostasis. These results may help explain why premenopausal women have lower incidence of T2D than age-matched men and suggest that targeting ERα can be a potential approach to modulate glucose metabolism and prevent diabetes.