Phosphatidylinositol 3-kinase Research Articles

Kuwanon G inhibits growth, migration and invasion of gastric cancer cells by regulating the PI3K/AKT/mTOR pathway

To investigate the effects of kuwanon G (KG) on proliferation, apoptosis, migration and invasion of gastric cancer cells and the molecular mechanisms. The effects of KG on proliferation and growth of gastric cancer cells were assessed with CCK-8 assay and cell clone formation assay, by observing tumor formation on the back of nude mice and using immunohistochemical analysis of Ki-67. The effect of KG on cell apoptosis was analyzed using Annexin V-FITC/PI apoptosis detection kit, Western blotting and TUNEL staining. The effects of KG on cell migration and invasion were detected using Transwell migration and invasion assay and Western blotting for matrix metalloproteinase (MMP). The role of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in KG-mediated regulation of gastric cancer cell proliferation, migration, and invasion was verified by Western blotting and rescue assay. KG significantly inhibited proliferation and reduced clone formation ability of gastric cancer cells in a concentration-dependent manner (P < 0.05). KG treatment also increased apoptosis, enhanced the expressions of cleaved caspase-3 and Bax, down-regulated Bcl-2, lowered migration and invasion capacities and inhibited the expression of MMP2 and MMP9 in gastric cancer cells (P < 0.05). Mechanistic validation showed that KG inhibited the activation of the PI3K/AKT/mTOR pathway, and IGF-1, an activator of the PI3K/AKT/mTOR pathway, reversed the effects of KG on proliferation, migration and invasion of gastric cancer cells (P < 0.05). KG inhibits proliferation, migration and invasion and promotes apoptosis of gastric cancer cells at least in part by inhibiting the activation of the PI3K/AKT/mTOR pathway.

PI3K couples long-term synaptic potentiation with cofilin recruitment and actin polymerization in dendritic spines via its regulatory subunit p85α

Long-term synaptic plasticity is typically associated with morphological changes in synaptic connections. However, the molecular mechanisms coupling functional and structural aspects of synaptic plasticity are still poorly defined. The catalytic activity of type I phosphoinositide-3-kinase (PI3K) is required for specific forms of synaptic plasticity, such as NMDA receptor-dependent long-term potentiation (LTP) and mGluR-dependent long-term depression (LTD). On the other hand, PI3K signaling has been linked to neuronal growth and synapse formation. Consequently, PI3Ks are promising candidates to coordinate changes in synaptic strength with structural remodeling of synapses. To investigate this issue, we targeted individual regulatory subunits of type I PI3Ks in hippocampal neurons and employed a combination of electrophysiological, biochemical and imaging techniques to assess their role in synaptic plasticity. We found that a particular regulatory isoform, p85α, is selectively required for LTP. This specificity is based on its BH domain, which engages the small GTPases Rac1 and Cdc42, critical regulators of the actin cytoskeleton. Moreover, cofilin, a key regulator of actin dynamics that accumulates in dendritic spines after LTP induction, failed to do so in the absence of p85α or when its BH domain was overexpressed as a dominant negative construct. Finally, in agreement with this convergence on actin regulatory mechanisms, the presence of p85α in the PI3K complex determined the extent of actin polymerization in dendritic spines during LTP. Therefore, this study reveals a molecular mechanism linking structural and functional synaptic plasticity through the coordinate action of PI3K catalytic activity and a specific isoform of the regulatory subunits.

US Food and Drug Administration Approval Summary: Capivasertib With Fulvestrant for Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Locally Advanced or Metastatic Breast Cancer With PIK3CA/AKT1/PTEN Alterations.

The US Food and Drug Administration (FDA) approved capivasertib in combination with fulvestrant for adult patients with hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced, or metastatic breast cancer (MBC) who have received at least one previous endocrine therapy and whose tumors harbor one or more phosphatidylinositol 3-kinase (PIK3CA)/AKT Serine/Threonine Kinase 1 (AKT1)/phosphatase and tensin homolog (PTEN) alterations, as detected by an FDA-approved test. Approval was based on CAPItello-291, a randomized, double-blind, multicenter trial of 708 patients with hormone receptor-positive, HER2-negative advanced or MBC, including 289 patients with PIK3CA/AKT1/PTEN tumor alterations. Patients were randomly assigned 1:1 to receive capivasertib 400 mg twice daily for 4 days per week with fulvestrant versus placebo with fulvestrant. Random assignment was stratified by presence of liver metastases, previous treatment with CDK4/6i, cyclin-dependent kinase four and six (CDK4/6) inhibitors, and geographical region. A statistically significant progression-free survival (PFS) benefit was demonstrated in the overall population (hazard ratio [HR], 0.6 [95% CI, 0.51 to 0.71]); this result was driven by 289 patients in the biomarker-positive population (HR, 0.5 [95% CI, 0.37 to 0.68]). An exploratory analysis of investigator-assessed PFS in the 313 (44%) patients in the biomarker-negative population showed uncertain benefit (HR, 0.78 [95% CI, 0.60 to 1.01]). With capivasertib, more patients had Grade ≥3 toxicities. Key concerns included hyperglycemia (18% all-grade, 2.8% Grade ≥3), cutaneous toxicity (58% all-grade, 17% Grade ≥3), and diarrhea (72% all-grade, 9% Grade ≥3). Capivasertib with fulvestrant was approved for patients whose tumors harbored PIK3CA/AKT1/PTEN alterations. Benefit-risk assessment in this subgroup was favorable based on a statistically significant and clinically meaningful improvement in PFS in the context of an acceptable safety profile including no evidence of a potential detriment in overall survival. By contrast, the benefit-risk was unfavorable in the biomarker-negative population.

Alpha-linolenic acid/linoleic acid ratio can effectively promote muscle growth and protein deposition in grass carp (Ctenopharyngodon idella)

Polyunsaturated fatty acids (PUFAs) promoted the muscle structure (muscle fiber cross-sectional area and diameter, as well as thickness of the connective tissue surrounding muscle fibers-endomysium) and taste (fishy) of fillets. As members of the omega-3 and omega-6 PUFA family, alpha-linolenic acid (ALA) and linoleic acid (LNA) have important functions. This study explores influences of ALA/LNA ratio on muscle growth and protein deposition and its mechanisms. Six different diets containing ALA/LNA ratios (0.03, 0.47, 0.92, 1.33, 1.69, and 2.15) were fed to grass carp (Ctenopharyngodon idella) for 9 weeks. Results showed that according to the quadratic regression model, the optimal ALA/LNA ratios of grass carp were 1.12 and 1.22 using malondialdehyde content and muscle fiber diameter as indicators, respectively. Optimum ALA/LNA ratio promoted hypertrophy of myofibers, which might be attributed to genes related to myofiber development (myogenic determinant, myogenin, myosin heavy chain, myogenic regulatory factor 4 and myogenic factor 5). Optimum ALA/LNA ratio enhanced protein deposition, which might be associated with the promotion of protein synthesis (insulin-like growth factors-1, phosphoinositide 3-kinase, target of rapamycin), and inhibition of the ubiquitin-proteasome system and autophagy-lysosome system to inhibit protein degradation. In addition, optimum ALA/LNA ratio enhanced muscle amino acid composition and antioxidant capacity of fish.

Splicing Factor PTBP1 Silencing Induces Apoptosis of Human Cervical Cancer Cells via PI3K/AKT Pathway and Autophagy.

Cervical cancer is the most common gynecological malignancy in the world and seriously threatens to women's lives and health. Polypyrimidine tract binding protein 1 (PTBP1), as an important splicing factor, has been identified as a proto-oncogene in several cancers, but its role and mechanism in cervical cancer remain poorly understood. Thus, our aim is to explore the impact of PTBP1 on proliferation, migration, apoptosis of cervical cancer cells, and its underlying mechanisms. The biological functions in cervical cancer cells were determined using small interfering RNA (siRNA), agonist, Cell Counting Kit-8 (CCK-8), transwell, migration test, western blot, real-time-PCR, immunohistochemistry and immunofluorescence, respectively. The results indicated that PTBP1 was highly expressed in cervical cancer patients and cervical cancer cell lines compared to the normal group. Moreover, PTBP1 silencing significantly inhibited cell proliferation, and migration in both HeLa and SiHa cells. The PTBP1 silencing also induced mitochondrial apoptosis through upregulating Bax and mitochondrial apoptotic protein Cytochrome C, and downregulating B-Cell Leukemia/Lymphoma 2 (Bcl2) protein. Additionally, PTBP1 silencing induced autophagy by downregulating Sequestosome I (p62) and upregulating the ratio of Light chain 3-Ⅱ/Light chain 3-Ⅰ (LC3-Ⅱ/LC3-Ⅰ). Mechanistically, we found that the Phosphoinositide 3-kinase (PI3K) agonist reversed the changes induced by PTBP1 silencing. Overall, PTBP1 silencing can induce cervical cancer cells apoptosis mainly through PI3K/AKT pathway and protective autophagy. This study provides preliminary evidence for PTBP1 as a therapeutic target or prognostic marker for cervical cancer.

Vitexin Induces Apoptosis and Ferroptosis and Suppresses Malignant Proliferation and Invasion of Bladder Urothelial Carcinoma through PI3K/AKT-Nrf2 Axis

Background: Bladder urothelial carcinoma (BUC) is a type of malignant urinary system. Although several strategies have been applied in the treatment of BUC, its survival remains unsatisfactory, especially in the patients with advanced BUC. Vitexin, a natural flavonoid has exhibited the inhibitory effect on various tumors, however, its effect on BUC is still unclear. Objective: This study aimed to explore the effect of vitexin on the progression of BUC. Methods: The toxicity of vitexin on T24 and 5637 cells was detected by cell counting kit-8 (CCK-8). The effects of vitexin on proliferation, apoptosis, invasion, epithelial-mesenchymal transition (EMT) and ferroptosis in BUC cells were determined by CCK-8, flow cytometry, western blot, transwell and immunofluorescence assays. Additionally, the related mechanism was explored by examining the expression of the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT)-nuclear factor-erythroid 2 related factor 2 (Nrf2) pathway. Besides, in vivo validation was performed in the xenografted mice. Results: Vitexin reduced the BUC cell viability and enhanced the apoptosis rate and the relative protein expression of p53 and cleaved-caspase3. Also, vitexin decreased the invasion number, and increased the relative protein expression of E-cadherin with the decreased N-cadherin protein level in T24 and 5637 cells. Besides, vitexin promoted the levels of ROS and MDA, while reduced the GSH level. Vitexin also increased the level of iron, but decreased the relative protein expression of xCT and GPX4. Erastin further increased the vitexin-induced iron levels, whereas inverse outcomes were observed in the application of ferrostatin-1. Additionally, vitexin decreased the relative protein levels of PI3K, p-AKT/AKT, and nuclear Nrf2, while increased the relative protein level of cytoplasmic Nrf2. Overexpression of PI3K notably inverted the effect of vitexin on cell viability, apoptosis, invasion, level of ROS and iron. Furthermore, vitexin reduced the tumor volume and weight of xenografted mice. Vitexin decreased the protein level of N-cadherin, while increased apoptosis rate of xenografted mice. In addition, vitexin reduced the relative protein levels of PI3K, p-AKT/AKT, and nuclear Nrf2 with the enhanced relative protein expression of cytoplasmic Nrf2 in xenografted mice. Moreover, vitexin decreased the relative protein expression of xCT and GPX4 and the GSH level, whereas increased the MDA level in xenografted mice. Conclusion: Vitexin suppressed malignant proliferation and invasion and induced apoptosis and ferroptosis of BUC involving in PI3K/AKT-Nrf2 pathway.

Therapeutic Potential of Rosa davurica Pall. Root Extract as an Antidiabetic Agent: A Comprehensive Analysis from Molecular Mechanisms to In Vivo Efficacy.

Rosa davurica Pall. is widely used in traditional oriental herbal therapy, but its components and molecular mechanisms of action remain unclear. This study investigates the antidiabetic potential of Rosa davurica Pall. root extract (RDR) and elucidates its underlying molecular mechanisms with in vitro and in vivo models. Data from the current study show that RDR exhibits strong antioxidant activity and glucose homeostasis regulatory effects. It significantly impacts glucose homeostasis in C2C12 skeletal muscle cells by inhibiting α-glucosidase activity. Further molecular mechanistic studies revealed that RDR promoted glucose uptake by phosphorylation of AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC), but not Phosphatidylinositol 3-kinase (PI 3-kinase)/Akt in C2C12 skeletal muscle cells. These actions increased the expression and translocation of glucose transporter type 4 (GLUT4) to the plasma membrane. In addition, RDR treatment in the STZ-induced diabetic rats remarkably improved the low body weight, polydipsia, polyphagia, hyperglycemia, and islet architecture and increased the insulin/glucose ratio. The liver (ALT and AST) and kidney marker enzyme (BUN and creatinine) levels were restored by RDR treatment as well. Phytochemical analysis identified eight major constituents in RDR, crucial for its antioxidant and antidiabetic activity. Through the molecular docking of representative glucose transporter GLUT4 with these compounds, it was confirmed that the components of RDR had a significantly high binding score in terms of structural binding. These findings from the current study highlight the antidiabetic effects of RDR. Collectively, our data suggest that RDR might be a potential pharmaceutical natural product for diabetic patients.

Targeting colorectal cancer with Herba Patriniae and Coix seed: Network pharmacology, molecular docking, and in vitro validation

BACKGROUND Herba Patriniae and Coix seed (HC) constitute a widely utilized drug combination in the clinical management of colorectal cancer (CRC) that is known for its diuretic, anti-inflammatory, and swelling-reducing properties. Although its efficacy has been demonstrated in a clinical setting, the active compounds and their mechanisms of action in CRC treatment remain to be fully elucidated. AIM To identify the active, CRC-targeting components of HC and to elucidate the mechanisms of action involved. METHODS Active HC components were identified and screened using databases. Targets for each component were predicted. CRC-related targets were obtained from human gene databases. Interaction targets between HC and CRC were identified. A “drug-ingredient-target” network was created to identify the core components and targets involved. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to elucidate the key pathways involved. Molecular docking between core targets and key components was executed. In vitro experiments validated core monomers. RESULTS Nineteen active components of HC were identified, with acacetin as the primary active compound. The predictive analysis identified 454 targets of the active compounds in HC. Intersection mapping with 2685 CRC-related targets yielded 171 intervention targets, including 30 core targets. GO and KEGG analyses indicated that HC may influence the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. Molecular docking showed that acacetin exhibited an optimal interaction with AKT1 , identifying PI3K , AKT , and P53 as key genes likely targeted by HC during CRC treatment. Acacetin inhibited HT-29 cell proliferation and migration, as well as promoted apoptosis, in vitro . Western blotting analysis revealed increased p53 and cleaved caspase-3 expression and decreased levels of p-PI3K , p-Akt , and survivin, which likely contributed to CRC apoptosis. CONCLUSION Acacetin, the principal active compound in the HC pair, inhibited the proliferation and migration of HT-29 cells and promoted apoptosis through the PI3K/Akt/p53 signaling pathway.

Cascade STING activation of a ternary immunostimulant for colorectal cancer eradication via photodynamic DNA damage and T regulatory cell inhibition

Stimulator of interferon genes (STING) plays an essential role in initiating the innate anti-tumor immunity, which could be activated by the cytosolic DNA but suppressed by the immunosuppressive cells. In this work, a self-delivery ternary immunostimulant (designated as ImmSt) is fabricated for colorectal cancer therapy with the immunological cascades of photodynamic DNA damage and T regulatory cell inhibition. Among which, the photosensitizer of Chlorin e6 (Ce6), the STING agonist of 5,6-dimethylxanthine-4-acetic acid (DMXAA) and the phosphatidylinositol 3-kinases (PI3Ks) inhibitor of ZSTK474 could self-assemble into uniform nanomedicine without drug excipient, which enhances the drug stability, bioavailability and pharmacological activities. Importantly, the photodynamic therapy (PDT) effect of ImmSt produces enormous reactive oxygen species to ablate tumor cells, and also triggers the release of cytosolic DNA to amplify the STING signal in combination with the STING agonist. Moreover, ImmSt is able to induce a systemic anti-tumor immunity by the cascade activation of T cells and the decrease of T regulatory cells. In vitro and in vivo results confirm that ImmSt can efficiently eradicate colorectal cancer without severe side effects, which may provide a sophisticated mechanism for immunotherapy in consideration of the immune activation and immunosuppressive factors.

A comprehensive view on the fisetin impact on colorectal cancer in animal models: Focusing on cellular and molecular mechanisms.

Flavonoids, including fisetin, have been linked to a reduced risk of colorectal cancer (CRC) and have potential therapeutic applications for the condition. Fisetin, a natural flavonoid found in various fruits and vegetables, has shown promise in managing CRC due to its diverse biological activities. It has been found to influence key cell signaling pathways related to inflammation, angiogenesis, apoptosis, and transcription factors. The results of this study demonstrate that fisetin induces colon cancer cell apoptosis through multiple mechanisms. It impacts the p53 pathway, leading to increased levels of p53 and decreased levels of murine double minute 2, contributing to apoptosis induction. Fisetin also triggers the release of important components in the apoptotic process, such as second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI and cytochrome c. Furthermore, fisetin inhibits the cyclooxygenase-2 and wingless-related integration site (Wnt)/epidermal growth factor receptor/nuclear factor kappa B signaling pathways, reducing Wnt target gene expression and hindering colony formation. It achieves this by regulating the activities of cyclin-dependent kinase 2 and cyclin-dependent kinase 4, reducing retinoblastoma protein phosphorylation, decreasing cyclin E levels, and increasing p21 levels, ultimately influencing E2 promoter binding factor 1 and cell division cycle 2 (CDC2) protein levels. Additionally, fisetin exhibits various effects on CRC cells, including inhibiting the phosphorylation of Y-box binding protein 1 and ribosomal S6 kinase, promoting the phosphorylation of extracellular signal-regulated kinase 1/2, and disrupting the repair process of DNA double-strand breaks. Moreover, fisetin serves as an adjunct therapy for the prevention and treatment of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA)-mutant CRC, resulting in a reduction in phosphatidylinositol-3 kinase (PI3K) expression, Ak strain transforming phosphorylation, mTOR activity, and downstream target proteins in CRC cells with a PIK3CA mutation. These findings highlight the multifaceted potential of fisetin in managing CRC and position it as a promising candidate for future therapy development.

A behind-the-scenes role of BDNF in the survival and differentiation of spermatogonia.

Mouse spermatogenesis entails the maintenance and self-renewal of spermatogonial stem cells (SSCs), which require a complex web-like signaling network transduced by various cytokines. Although brain-derived neurotrophic factor (BDNF) is expressed in Sertoli cells in the testis, and its receptor tropomyosin receptor kinase B (TrkB) is expressed in the spermatogonial population containing SSCs, potential functions of BDNF for spermatogenesis have not been uncovered. Here, we generate BDNF conditional knockout mice and find that BDNF is dispensable for in vivo spermatogenesis and fertility. However, in vitro, we reveal that BDNF-deficient germline stem cells (GSCs) exhibit growth potential not only in the absence of glial cell line-derived neurotrophic factor (GDNF), a master regulator for GSC proliferation, but also in the absence of other factors, including epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and insulin. GSCs grown without these factors are prone to differentiation, yet they maintain expression of promyelocytic leukemia zinc finger (Plzf), an undifferentiated spermatogonial marker. Inhibition of phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), and Src pathways all interfere with the growth of BDNF-deficient GSCs. Thus, our findings suggest a role for BDNF in maintaining the undifferentiated state of spermatogonia, particularly in situations where there is a shortage of growth factors.

Study of the uptake mechanism of two small extracellular vesicle subtypes by granulosa cells

As a new mechanism of intercellular communication, the uptake of extracellular vesicles (EVs) by receptor cells has become a hot topic in the field. Previously, research on the uptake of EVs has focused on the mechanism of small EVs (sEVs, also known as exosomes). As sEVs represent a mixed heterogeneous population, the issue of whether there are different uptake mechanisms for different subsets of sEVs by recipient cells urgently need to be addressed. There are EVs in follicular fluid, which play an important role in the communication between follicular cells and the development of oocytes. Previously, we isolated two subtypes of sEVs in follicular fluid: low density-sEVs (LD-sEVs) and high density-sEVs (HD-sEVs). The current study aimed to explore the uptake characteristics of these two subtypes of sEVs by granulosa cells. First, PKH67 was used to label the two sEVs subtypes, and we observed their uptake by granulosa cells using confocal microscopy and flow cytometry. We then explored the specific mechanisms underlying uptake of these two sEV subtypes by granulosa cells using specific inhibitors and RNA interference. The results showed that granulosa cells took up both kinds of sEVs through a clathrin-independent pathway. In addition to requiring caveolin, cholesterol, and Na+/H+ exchange, the uptake of HD-sEVs also depended on the activity of tyrosine kinase and phosphoinositide 3-kinase. A better understanding of the mechanism of granulosa cell uptake of different subtypes of sEVs in follicular fluid is of considerable significance leading to more accurate use of EVs for targeted treatment of infertility and other related diseases.

Effect of Mifepristone on Migration and Proliferation of Oral Cancer Cells.

Glucocorticoid receptor (GR) overexpression has been linked to increased tumour aggressiveness and treatment resistance. GR antagonists have been shown to enhance treatment effectiveness. Emerging research has investigated mifepristone, a GR antagonist, as an anticancer agent with limited research in the context of oral cancer. This study investigated the effect of mifepristone at micromolar (µM) concentrations of 1, 5, 10 and 20 on the proliferation and migration of oral cancer cells, at 24 and 48 h. Scratch and scatter assays were utilised to assess cell migration, MTT assays were used to measure cell proliferation, Western blotting was used to investigate the expression of GR and the activation of underlying Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signalling pathways, and immunofluorescence (IF) was used to determine the localisation of proteins in HaCaT (immortalised human skin keratinocytes), TYS (oral adeno squamous cell carcinoma), and SAS-H1 cells (squamous cell carcinoma of human tongue). Mifepristone resulted in a dose-dependent reduction in the proliferation of HaCaT, TYS, and SAS-H1 cells. Mifepristone at a concentration of 20 µM effectively reduced collective migration and scattering of oral cancer cells, consistent with the suppression of the PI3K-Akt and MAPK signalling pathways, and reduced expression of N-Cadherin. An elongated cell morphology was, however, observed, which may be linked to the localisation pattern of E-Cadherin in response to mifepristone. Overall, this study found that a high concentration of mifepristone was effective in the suppression of migration and proliferation of oral cancer cells via the inhibition of PI3K-Akt and MAPK signalling pathways. Further investigation is needed to define its impact on epithelial-mesenchymal transition (EMT) markers.

MFGE8 promotes adult hippocampal neurogenesis in rats following experimental subarachnoid hemorrhage via modifying the integrin β3/Akt signaling pathway

Subarachnoid hemorrhage (SAH) is one of the most severe type of cerebral strokes, which can cause multiple cellular changes in the brain leading to neuronal injury and neurological deficits. Specifically, SAH can impair adult neurogenesis in the hippocampal dentate gyrus, thus may affecting poststroke neurological and cognitive recovery. Here, we identified a non-canonical role of milk fat globule epidermal growth factor 8 (MFGE8) in rat brain after experimental SAH, involving a stimulation on adult hippocampal neurogenesis(AHN). Experimental SAH was induced in Sprague-Dawley rats via endovascular perforation, with the in vivo effect of MFGE8 evaluated via the application of recombinant human MFGE8 (rhMFGE8) along with pharmacological interventions, as determined by hemorrhagic grading, neurobehavioral test, and histological and biochemical analyses of neurogenesis related markers. Results: Levels of the endogenous hippocampal MFGE8 protein, integrin-β3 and protein kinase B (p-Akt) were elevated in the SAH relative to control groups, while that of hippocalcin (HPCA) and cyclin D1 showed the opposite change. Intraventricular rhMGFE8 infusion reversed the decrease in doublecortin (DCX) immature neurons in the DG after SAH, along with improved the short/long term neurobehavioral scores. rhMGFE8 treatment elevated the levels of phosphatidylinositol 3-kinase (PI3K), p-Akt, mammalian target of rapamycin (mTOR), CyclinD1, HPCA and DCX in hippocampal lysates, but not that of integrin β3 and Akt, at 24 hr after SAH. Treatment of integrin β3 siRNA, the PI3K selective inhibitor ly294002 or Akt selective inhibitor MK2206 abolished the effects of rhMGFE8 after SAH. In conclusion, MFGE8 is upregulated in the hippocampus in adult rats with reduced granule cell genesis. rhMFGE8 administration can rescue this impaired adult neurogenesis and improve neurobehavioral recovery. Mechanistically, the effect of MFGE8 on hippocampal adult neurogenesis is mediated by the activation of integrin β3/Akt pathway. These findings suggest that exogenous MFGE8 may be of potential therapeutic value in SAH management.Graphical abstract and proposed pathway of rhMFGE8 administration attenuate hippocampal injury by improving neurogenesis in SAH models. SAH caused hippocampal injury and neurogenesis interruption. Administered exogenous MFGE8, recombinant human MFGE8(rhMFGE8), could ameliorate hippocampal injury and improve neurological functions after SAH. Mechanistically, MFGE8 bind to the receptor integrin β3, which activated the PI3K/Akt pathway to increase the mTOR expression, and further promote the expression of cyclin D1, HPCA and DCX. rhMFGE8 could attenuated hippocampal injury by improving neurogenesis after SAH, however, know down integrin β3 or pharmacological inhibited PI3K/Akt by ly294002 or MK2206 reversed the neuro-protective effect of rhMFGE8.

Fasting time after feeding affects the evaluation of metabolic response in abalone Haliotis discus hannai to nutrients using dietary methionine as an example

As one of the essential amino acid, methionine (Met) is the initiating amino acid for proteins synthesis, and it can also act as a molecular signal regulating various metabolic processes. Meanwhile, the postprandial metabolic responses varied greatly among different species, nutrients and fasting time. In the present study, postprandial metabolic responses of abalone Haliotis discus hannai fed with different levels of dietary methionine (0.46%, 1.19% and 2.07%, respectively) for 84 days were investigated. Compared with the group with 0.46% of dietary methionine, 2.07% of dietary methionine significantly increased the concentration of glucose in CFH at 0 h, 12 h, 24 h, 36 h, 60 h and 84 h, while the concentrations of ammonia were significantly decreased by 2.07% of dietary methionine at each time point after feeding (P < 0.05). The 1.19% of dietary methionine significantly increased the activity of trypsin at 0 h, 24 h 60 h and 84 h after feeding (P < 0.05). The phosphorylation levels of protein kinase B (AKT), mechanistic target of rapamycin (mTOR) and ribosomal s6 protein (S6) peaked at 12 h and then dropped to base level at 36–84 h. Compared with the group with 0.46% of dietary methionine, 1.19% of dietary methionine significantly increased the phosphorylation levels of AKT at 12 h and 24 h, and extended the phosphorylation time of AKT (P < 0.05). And the phosphorylation level of mTOR was significantly increased by 1.19% of dietary methionine at 12 h, 24 h and 36 h after feeding (P < 0.05). Significant activation or repression of the mRNA levels related to glucose and lipid metabolism were observed at 12–24 h after feeding, and most of which were remain stable at 36–84 h (P < 0.05). The expressions of genes related of insulin signaling pathway (phosphoinositide 3-kinase and protein kinase B), glycolysis (hexokinase) and transport of lipid (fatty acid transport protein) were significantly increased by 1.19% of dietary methionine, while the key gene of gluconeogenesis (glucose-6-phosphatase) were decreased. In summary, 1.19% of dietary methionine could enhance digestive and absorptive capacity, protein synthesis, glucose metabolism and fatty acid transportation of abalone. Take long-term feeding trial with dietary methionine as an example and combine the results of data analysis, it is suggested to analyze the protein level of mTOR signaling pathway within 36 h after feeding, assess the biochemical parameters in CFH and the mRNA levels of nutrient metabolism related genes within 36–84 h, and detect the activities of digestive and absorptive enzymes within 60–84 h.

Significance of phosphoinositide 3-kinase inhibitors in advanced breast cancer: a systematic review and meta-analysis.

The Phosphoinositide 3-kinase (PI3K) inhibitors may be used in cancer progression and mortality along with standard therapy to improve therapeutic efficacy of Advanced Breast Cancer (ABC). This systematic review and meta- analysis were conducted to understand the therapeutic and toxicity profile of PI3K inhibitors in ABC. The electronic databases were searched for suitable trials as per the criteria. The outcomes assessed were Progression- Free Survival, Objective Response Rate and Disease Control Rate. The data were systematically reviewed and meta-analyzed by Mantele- Haenszel method. Seven studies were included in the systematic review and meta- analysis. The co- administration of PI3K inhibitors with standard therapy improved the Progression- Free Survival significantly, while a marginal improvement was observed in Objective Response Rate, no difference in Disease Control Rate and toxicity significantly increased. The addition of PI3K inhibitors decreased the risk of progression but increased the risk of toxicity.

Downregulation of Rad51 Expression and Activity Potentiates the Cytotoxic Effect of Osimertinib in Human Non-Small Cell Lung Cancer Cells.

Osimertinib (AZD9291) is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that has shown significant clinical benefits in patients with EGFR-sensitizing mutations or the EGFR T790M mutation. The homologous recombination (HR) pathway is crucial for repairing DNA double-strand breaks (DSBs). Rad51 plays a central role in HR, facilitating the search for homology and promoting DNA strand exchange between homologous DNA molecules. Rad51 is overexpressed in numerous types of cancer cells. B02, a specific small molecule inhibitor of Rad51, inhibits the DNA strand exchange activity of Rad51. Previous studies have indicated that B02 disrupted Rad51 foci formation in response to DNA damage and inhibited DSBs repair in human cells and sensitized them to chemotherapeutic drugs in vitro and in vivo. However, the potential therapeutic effects of combining osimertinib with a Rad51 inhibitor are not well understood. The aim of this study was to elucidate whether the downregulation of Rad51 expression and activity can enhance the osimertinib-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells. We used the MTS, trypan blue dye exclusion and colony-formation ability assay to determine whether osimertinib alone or in combination with B02 had cytotoxic effects on NSCLC cell lines. Real-time polymerase chain reaction was conducted to measure the amounts of Rad51 mRNA. The protein levels of phosphorylated AKT and Rad51 were determined by Western blot analysis. We found that osimertinib reduced Rad51 expression by inactivating AKT activity. Rad51 knockdown using small interfering RNA or AKT inactivation through the phosphatidylinositol 3-kinase inhibitor LY294002 or si-AKT RNA transfection enhanced the cytotoxic and growth inhibitory effects of osimertinib. In contrast, AKT-CA (a constitutively active form of AKT) vector-enforced expression could mitigate the cytotoxic and cell growth inhibitory effects of osimertinib. Furthermore, B02 significantly enhanced the cytotoxic and cell growth inhibitory effects of osimertinib in NSCLC cells. Compared to parental cells, the activation of AKT and Rad51 expression in osimertinib-resistant cells could not be significantly inhibited by osimertinib treatment. Moreover, the increased expression of Rad51 is associated with the resistance mechanism in osimertinib-resistant H1975 and A549 cells. Collectively, the downregulation of Rad51 expression and activity enhances the cytotoxic effect of osimertinib in human NSCLC cells.

The neuroprotective effects of alpha lipoic acid in rotenone-induced Parkinson's disease in mice via activating PI3K/AKT pathway and antagonizing related inflammatory cascades

Parkinson's disease (PD) is an idiopathic disease caused by the loss or degeneration of the dopaminergic (dopamine-producing) neurons in the brain and characterized by various inflammatory and apoptotic responses in the neuronal cells. Phosphoinositide 3–kinase (PI3K)/protein kinase B (Akt) axis is responsible for neuronal survival by providing a number of anti-inflammatory and anti-apoptotic milieu that prevent the progression of PD. Alpha-lipoic acid (ALA) is a natural cofactor that has antioxidant capacity and contributes to various metabolic processes. ALA can penetrate the blood-brain barrier and contribute to numerous neuroprotective effects. It can activate PI3K/AKT pathway with consequent reduction of different inflammatory and oxidative biomarkers. Our work aims to unfold the neuroprotective effects of ALA via targeting PI3k/AKT pathway. Forty male mice were divided into four groups: control, ALA (100 mg/kg/day; i.p.), rotenone (ROT) (1.5 mg/kg/2 days, i.p.) and rotenone + ALA for 21 days. ALA showed obvious neuroprotective effects via significant activation of PI3K/AKT pathway with subsequent decreasing level of Caspase-3. ALA resulted in prominent anti-inflammatory actions by decreasing interlukin-1β (IL-1β), tumor necrosis factor (TNF)-α and nuclear factor kabba (NFk)-B. ALA remarkably induced antioxidant activities via increasing reduced glutathione (GSH) and superoxide dismutase (SOD) levels as well as decreasing malondialdehyde (MDA) level. The substantial behavioral improvement reflected in these results was noticed in the ALA-treated mice as a reflection of the neuroprotective activities of ALA. In conclusion, ALA showed promising neuroprotective effects in rotenone-induced PD via activating the PI3K/AKT pathway and consequent inhibition of apoptotic and inflammatory biomarkers.

Effects of arsenic exposure on the PI3K/Akt/NF-κB signaling pathway in the hippocampus of offspring mice at different developmental stages

The primary purpose of present study was to explore the effects of arsenic exposure on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/nuclear transcription factor-κB (NF-κB) signaling pathway in the hippocampus of offspring mice at different developmental stages. Sodium arsenite (NaAsO2) at doses of 0, 15, 30 or 60 mg/L administered to female mice and their pups. The nuclear translocation levels of NF-κB were assessed by EMSA. Real-time RT-PCR was used to measure Akt, NF-κB and PI3K mRNA levels. Protein expressions of PI3K, p-Akt, inhibitor kappa B kinase (IKK), p-NF-κB, protein kinase A (PKA), inhibitor kappa B (IκB), and cAMP response element-binding protein (CREB) were measured by Western blot. Results disclosed that exposure to 60 mg/L NaAsO2 could suppress NF-κB levels of nuclear translocation of postnatal day (PND) 20 and PND 40 mice. Arsenic downregulated the transcriptional and translational levels of PI3K, Akt and NF-κB. Additionally, protein expressions of p-IKK, p-IκB, PKA and p-CREB also reduced. Taken together, results of present study indicated that arsenic could downregulate the PI3K/Akt/NF-κB signaling pathway, particularly on PND 40, which might be involved in the cognitive impairments.

Insulin enhances acid-sensing ion channel currents in rat primary sensory neurons

Insulin has been shown to modulate neuronal processes through insulin receptors. The ion channels located on neurons may be important targets for insulin/insulin receptor signaling. Both insulin receptors and acid-sensing ion channels (ASICs) are expressed in dorsal root ganglia (DRG) neurons. However, it is still unclear whether there is an interaction between them. Therefore, the purpose of this investigation was to determine the effects of insulin on the functional activity of ASICs. A 5 min application of insulin rapidly enhanced acid-evoked ASIC currents in rat DRG neurons in a concentration-dependent manner. Insulin shifted the concentration–response plot for ASIC currents upward, with an increase of 46.2 ± 7.6% in the maximal current response. The insulin-induced increase in ASIC currents was eliminated by the insulin receptor antagonist GSK1838705, the tyrosine kinase inhibitor lavendustin A, and the phosphatidylinositol-3 kinase antagonist wortmannin. Moreover, insulin increased the number of acid-triggered action potentials by activating insulin receptors. Finally, local administration of insulin exacerbated the spontaneous nociceptive behaviors induced by intraplantar acid injection and the mechanical hyperalgesia induced by intramuscular acid injections through peripheral insulin receptors. These results suggested that insulin/insulin receptor signaling enhanced the functional activity of ASICs via tyrosine kinase and phosphatidylinositol-3 kinase pathways. Our findings revealed that ASICs were targets in primary sensory neurons for insulin receptor signaling, which may underlie insulin modulation of pain.