Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 106
Filter
1.
Journal of Integrative Medicine ; (12): 418-427, 2021.
Article in English | WPRIM | ID: wpr-888773

ABSTRACT

OBJECTIVE@#Exercise, as a common non-drug intervention, is one of several lifestyle choices known to reduce the risk of cancer. Mitochondrial division has been reported to play a key role in the occurrence and transformation of hepatocellular carcinoma (HCC). This study investigated whether exercise could regulate the occurrence and development of HCC through mitosis.@*METHODS@#Bioinformatics technology was used to analyze the expression level of dynamin-related protein 1 (DRP1), a key protein of mitochondrial division. The effects of DRP1 and DRP1 inhibitor (mdivi-1) on the proliferation and migration of liver cancer cells BEL-7402 were observed using cell counting kit-8, plate colony formation, transwell cell migration, and scratch experiments. Enzyme-linked immunosorbent assay, Western blot and real-time polymerase chain reaction were used to detect the expression of DRP1 and its downstream phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway. A treadmill exercise intervention was tested in a nude mouse human liver cancer subcutaneous tumor model expressing different levels of DRP1. The size and weight of subcutaneous tumors in mice were detected before and after exercise.@*RESULTS@#The expression of DRP1 in liver cancer tissues was significantly upregulated compared with normal liver tissues (P < 0.001). The proliferation rate and the migration of BEL-7402 cells in the DRP1 over-expression group were higher than that in the control group. The mdivi-1 group showed an inhibitory effect on the proliferation and migration of BEL-7402 cells at 50 μmol/L. Aerobic exercise was able to inhibit the expression of DRP1 and decrease the size and weight of subcutaneous tumors. Moreover, the expression of phosphorylated PI3K (p-PI3K) and phosphorylated AKT (p-AKT) decreased in the exercise group. However, exercise could not change p-PI3K and p-AKT levels after knocking down DRP1 or using mdivi-1 on subcutaneous tumor.@*CONCLUSION@#Aerobic exercise can suppress the development of tumors partially by regulating DRP1 through PI3K/AKT pathway.


Subject(s)
Animals , Apoptosis , Carcinoma, Hepatocellular/therapy , Cell Line, Tumor , Cell Proliferation , Down-Regulation , Dynamins , Liver Neoplasms/therapy , Mice , Phosphatidylinositol 3-Kinase/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction
2.
Chinese Medical Journal ; (24): 699-707, 2021.
Article in English | WPRIM | ID: wpr-878065

ABSTRACT

BACKGROUND@#Autophagy of alveolar macrophages is a crucial process in ischemia/reperfusion injury-induced acute lung injury (ALI). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent cells with the potential for repairing injured sites and regulating autophagy. This study was to investigate the influence of BM-MSCs on autophagy of macrophages in the oxygen-glucose deprivation/restoration (OGD/R) microenvironment and to explore the potential mechanism.@*METHODS@#We established a co-culture system of macrophages (RAW264.7) with BM-MSCs under OGD/R conditions in vitro. RAW264.7 cells were transfected with recombinant adenovirus (Ad-mCherry-GFP-LC3B) and autophagic status of RAW264.7 cells was observed under a fluorescence microscope. Autophagy-related proteins light chain 3 (LC3)-I, LC3-II, and p62 in RAW264.7 cells were detected by Western blotting. We used microarray expression analysis to identify the differently expressed genes between OGD/R treated macrophages and macrophages co-culture with BM-MSCs. We investigated the gene heme oxygenase-1 (HO-1), which is downstream of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway.@*RESULTS@#The ratio of LC3-II/LC3-I of OGD/R treated RAW264.7 cells was increased (1.27 ± 0.20 vs. 0.44 ± 0.08, t = 6.67, P  < 0.05), while the expression of p62 was decreased (0.77 ± 0.04 vs. 0.95 ± 0.10, t = 2.90, P  < 0.05), and PI3K (0.40 ± 0.06 vs. 0.63 ± 0.10, t = 3.42, P  < 0.05) and p-Akt/Akt ratio was also decreased (0.39 ± 0.02 vs. 0.58 ± 0.03, t = 9.13, P  < 0.05). BM-MSCs reduced the LC3-II/LC3-I ratio of OGD/R treated RAW264.7 cells (0.68 ± 0.14 vs. 1.27 ± 0.20, t = 4.12, P  < 0.05), up-regulated p62 expression (1.10 ± 0.20 vs. 0.77 ± 0.04, t = 2.80, P  < 0.05), and up-regulated PI3K (0.54 ± 0.05 vs. 0.40 ± 0.06, t = 3.11, P  < 0.05) and p-Akt/Akt ratios (0.52 ± 0.05 vs. 0.39 ± 0.02, t = 9.13, P  < 0.05). A whole-genome microarray assay screened the differentially expressed gene HO-1, which is downstream of the PI3K/Akt signaling pathway, and the alteration of HO-1 mRNA and protein expression was consistent with the data on PI3K/Akt pathway.@*CONCLUSIONS@#Our results suggest the existence of the PI3K/Akt/HO-1 signaling pathway in RAW264.7 cells under OGD/R circumstances in vitro, revealing the mechanism underlying BM-MSC-mediated regulation of autophagy and enriching the understanding of potential therapeutic targets for the treatment of ALI.


Subject(s)
Apoptosis , Autophagy , Bone Marrow , Glucose , Heme Oxygenase-1/metabolism , Macrophages/metabolism , Mesenchymal Stem Cells/metabolism , Oxygen , Phosphatidylinositol 3-Kinase , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction
3.
Braz. j. med. biol. res ; 53(9): e9693, 2020. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS | ID: biblio-1132556

ABSTRACT

Ischemic heart disease (IHD) is one of the leading causes of death worldwide. C-type lectin domain family 3 member B (CLEC3B) is a C-type lectin superfamily member and is reported to promote tissue remodeling. The serum levels of CLEC3B are downregulated in patients with cardiovascular disease. However, the molecular mechanisms of CLEC3B in IHD is not well-characterized. Therefore, we overexpressed CLEC3B and silenced CLEC3B in H9c2 rat cardiomyocytes for the first time. We then constructed a model of IHD in vitro through culturing H9c2 cardiomyocytes in serum-free medium under oxygen-deficit conditions. Then, Cell Counting Kit-8 (CCK-8), flow cytometry, qRT-PCR, and western blot assays were performed to investigate cell viability, apoptosis, and expression levels of CLEC3B, phosphatidylinositol 3-kinase (PI3K), phosphorylated PI3K (p-PI3K), protein kinase B (Akt), phosphorylated Akt (p-Akt), and cleaved-caspase 3. We observed that the mRNA expression of CLEC3B was decreased in hypoxic H9c2 cardiomyocytes (P<0.05). Overexpression of CLEC3B increased cell viability (P<0.01), inhibited cell apoptosis (P<0.05), upregulated the levels of p-PI3K/PI3K and p-Akt/Akt (P<0.01 or P<0.05), and downregulated expression of cleaved-caspase 3 (P<0.001) in hypoxic H9c2 cardiomyocytes while silencing of CLEC3B caused the opposite results. Inhibition of the PI3K/Akt pathway reversed the protective effect of CLEC3B on hypoxic H9c2 cardiomyocytes. Our study demonstrated that CLEC3B alleviated the injury of hypoxic H9c2 cardiomyocytes via the PI3K/Akt pathway.


Subject(s)
Humans , Animals , Rats , Apoptosis/physiology , Lectins, C-Type/metabolism , Signal Transduction , Phosphatidylinositol 3-Kinases , Myocytes, Cardiac/physiology , Proto-Oncogene Proteins c-akt/metabolism , Phosphatidylinositol 3-Kinase , Hypoxia
4.
Neuroscience Bulletin ; (6): 471-485, 2019.
Article in English | WPRIM | ID: wpr-775426

ABSTRACT

Epilepsy is a chronic and severe neurological disorder that has negative effects on the autonomous activities of patients. Functionally, Trem2 (triggering receptor expressed on myeloid cells-2) is an immunoglobulin receptor that affects neurological and psychiatric genetic diseases. Based on this rationale, we aimed to assess the potential role of Trem2 integration with the PI3K/Akt pathway in epilepsy. We used microarray-based gene expression profiling to identify epilepsy-related differentially-expressed genes. In a mouse hippocampal neuron model of epilepsy, neurons were treated with low-Mg extracellular fluid, and the protein and mRNA expression of Trem2 were determined. Using a gain-of-function approach with Trem2, neuronal apoptosis and its related factors were assessed by flow cytometry, RT-qPCR, and Western blot analysis. In a pilocarpine-induced epileptic mouse model, the malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) content and superoxide dismutase (SOD) and glutathione-peroxidase (GSH-Px) activity in the hippocampus were determined, and the protein expression of Trem2 was measured. In addition, the regulatory effect of Trem2 on the PI3K/Akt pathway was analyzed by inhibiting this pathway in both the cell and mouse models of epilepsy. Trem2 was found to occupy a core position and was correlated with epilepsy. Trem2 was decreased in the hippocampus of epileptic mice and epileptic hippocampal neurons. Of crucial importance, overexpression of Trem2 activated the PI3K/Akt pathway to inhibit neuronal apoptosis. Moreover, activation of the PI3K/Akt pathway through over-expression of Trem2 alleviated oxidative stress, as shown by the increased expression of SOD and GSH-Px and the decreased expression of MDA and 8-OHdG. The current study defines the potential role of Trem2 in inhibiting the development of epilepsy, indicating that Trem2 up-regulation alleviates hippocampal neuronal injury and oxidative stress, and inhibits neuronal apoptosis in epilepsy by activating the PI3K/Akt pathway.


Subject(s)
Animals , Apoptosis , Cells, Cultured , Epilepsy , Metabolism , Gene Expression Profiling , Hippocampus , Metabolism , Male , Membrane Glycoproteins , Metabolism , Mice, Inbred ICR , Neurons , Metabolism , Oxidative Stress , Phosphatidylinositol 3-Kinase , Metabolism , Proto-Oncogene Proteins c-akt , Metabolism , Receptors, Immunologic , Metabolism , Signal Transduction , Up-Regulation
5.
Article in English | WPRIM | ID: wpr-764076

ABSTRACT

Bone marrow mesenchymal stem cells (BM MSCs) can differentiate into multi-lineage tissues. However, obtaining BM MSCs by aspiration is difficult and can be painful; therefore peripheral blood (PB) MSCs might provide an easier alternative for clinical applications. Here, we show that circulating PB MSCs proliferate as efficiently as BM MSCs in the presence of extracellular matrix (ECM) and that differentiation potential into osteoblast in vitro and in vivo. Both BM MSCs and PB MSCs developed into new bone when subcutaneously transplanted into immune-compromised mice using hydroxyapatite/tricalcium phosphate as a carrier. Furthermore, LY294002 and Wortmannin blocked mesenchymal stem cell attachment in a dose-dependent manner, suggesting a role of phosphatidylinositol 3-kinase in MSC attachment. Our data showed that the growth of PB MSCs could be regulated by interaction with the ECM and that these cells could differentiate into osteoblasts, suggesting their potential for clinical applications.


Subject(s)
Animals , Bone Marrow , Extracellular Matrix , In Vitro Techniques , Mesenchymal Stem Cells , Mice , Osteoblasts , Phosphatidylinositol 3-Kinase , Phosphatidylinositols
6.
J. coloproctol. (Rio J., Impr.) ; 38(1): 1-8, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-894029

ABSTRACT

ABSTRACT Objectives: Determine immunohistochemical expression of Phosphatase and tensin homolog (PTEN), Phosphatidylinositol 3 kinase (PI3K), Cycloxygenase-2 (COX2) and one proliferation marker (Ki67) in colorectal polyps and correlate with clinical and pathological data in search of carcinogenic pathways. Methods: The reports of 297 polyps diagnosed through endoscopy were reviewed for parameters including age, gender, prior colorectal cancer, the presence of multiple polyps, and polyps' location, appearance and size. Was conducted a microscopic morphometric computerized analysis of immunohistochemical expression using, the selected antibodies and correlated with clinical and pathological variables. Results: The tissue immunohistochemical expression was higher in right colon polyps for the proliferation marker and Phosphatidylinositol 3 kinase (p ≤ 0.0001 and 0.057 respectively). Cycloxygenase-2 and Phosphatase and tensin homolog demonstrated higher tissue immunoexpression in pedunculated polyps (p = 0.009 and 0.002 respectively). Cycloxygenase-2 exhibited higher immunoexpression in larger polyps (p = 0.005). Phosphatidylinositol 3 kinase, Cycloxygenase-2, Phosphatase and tensin homolog and the proliferation marker exhibited higher immunoexpression in high-grade dysplastic polyps (p = 0.031, 0.013, 0.044 and <0.001 respectively). Phosphatase and tensin homolog labeling was higher in polyps with high-grade dysplasia and lower in some of serrated lesions (p = 0.044). Conclusions: The greater expression of the proliferation marker and Phosphatidylinositol 3 kinase in the right colon may be related to right-sided colorectal carcinogenesis. The proliferation marker, Cycloxygenase-2 and Phosphatidylinositol 3 kinase results can be associated with progression of polyps to colorectal cancer. The higher Phosphatase and tensin homolog expression suggests its attempt to control the cell cycle.


RESUMO Objetivos: Determinar a expressão imuno-histoquímica de Fosfatase homóloga a tensina (PTEN), Fosfatidilinositol-3-cinase (PI3K), Ciclooxigenase-2 (COX2) e um marcador de proliferação (Ki67) em pólipos colorretais e correlacionar com dados clínicos e patológicos buscando sua correspondência na carcinogênese. Métodos: Revisados 297 pólipos diagnosticados através de endoscopia quanto a idade, gênero, história de câncer colorretal, número, localização, aparência e tamanho dos pólipos. Realizadas as avaliações morfométricas computadorizadas das expressões imuno-histoquímicas dos marcadores selecionados, que foram correlacionadas com variáveis clínicas e patológicas. Resultados: A expressão do marcador de proliferação e da Fosfatidilinositol-3-cinase foi maior nos pólipos do cólon direito (p = <0,0001 e 0.057 respectivamente). Ciclooxigenase-2 e Fosfatase homóloga a tensina demonstraram maior imunoexpressão em pólipos pediculados (p = 0,009 e 0,002, respectivamente). Ciclooxigenase-2 expressou mais em pólipos maiores (p = 0,005). Fosfatidilinositol-3-cinase, Ciclooxigenase-2, Fosfatase homóloga a tensina e o marcador de proliferação expressaram mais em pólipos com displasia de alto grau (p = 0,031, 0,013, 0,044 e <0,001, respectivamente). Fosfatase homóloga a tensina marcou mais pólipos com displasia de alto grau que lesões serrilhadas (p = 0,044). Conclusões: A maior expressão do marcador de proliferação e Fosfatidilinositol-3-cinase à direita pode estar relacionada à carcinogênese do lado direito do cólon. Os resultados do marcador de proliferação, Ciclooxigenase-2 e Fosfatidilinositol-3-cinase podem ser associados à progressão dos pólipos para câncer. A expressão aumentada de Fosfatase homóloga a tensina sugere tentativa de controle do ciclo celular.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Colorectal Neoplasms/diagnosis , Colonic Polyps/pathology , Ki-67 Antigen/immunology , PTEN Phosphohydrolase/immunology , Cyclooxygenase 2/immunology , Phosphatidylinositol 3-Kinase/immunology
7.
Article in English | WPRIM | ID: wpr-717675

ABSTRACT

PURPOSE: Maternal lipopolysaccharide (LPS) injection induces neurodevelopmental disorders, such as cerebral palsy. Exercise activates phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway that enhances neurogenesis. Wnt ligands are also implicated in the hippocampal neurogenesis and synaptic plasticity. Glycogen synthase kinase-3β (GSK-3β) is a downstream molecule of Akt, and GSK-3β is known to modulate hippocampal neurogenesis negatively. METHODS: Cerebral palsy was made by maternal LPS-injection. On the 5 weeks after birth, treadmill running was applied to the rat pups of the exercise groups, for 30 minutes, 5 times a week during 6 weeks. RESULTS: Treadmill running alleviated short-term memory impairments of the cerebral palsy rat pups. Hippocampal cell proliferation was increased and hippocampal apoptosis was suppressed by treadmill running in the cerebral palsy rat pups. Hippocampal phosphorylated-PI3K/PI3K ratio, phosphorylated-Akt/Akt ratio, and Wnt expression were enhanced by treadmill running in the cerebral palsy rat pups. In contrast, hippocampal phosphorylated-GSK-3β/GSK-3β ratio and β-catenin expression were suppressed by treadmill running in the cerebral palsy rat pups. CONCLUSIONS: The results of this study showed that short-term memory improvement due to treadmill running in cerebral palsy occurs via activation of the PI3K-Akt-Wnt pathway.


Subject(s)
Animals , Apoptosis , Cell Proliferation , Cerebral Palsy , Glycogen Synthase , Ligands , Memory, Short-Term , Neurodevelopmental Disorders , Neurogenesis , Neuronal Plasticity , Parturition , Phosphatidylinositol 3-Kinase , Phosphotransferases , Proto-Oncogene Proteins c-akt , Rats , Running
8.
Chinese Medical Journal ; (24): 1849-1856, 2018.
Article in English | WPRIM | ID: wpr-773966

ABSTRACT

Background@#Nucleoside reverse transcriptase inhibitors (NRTIs) are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. However, NRTI drug therapy can cause peripheral neuropathic pain. In this study, we aimed to investigate the mechanisms of rapamycin on the pain sensitization of model mice by in vivo experiments to explore the effect of mammalian target of rapamycin (mTOR) in the pathogenesis of neuropathic pain caused by NRTIs.@*Methods@#Male Kun Ming (KM) mice weighing 20-22 g were divided into control, 2 mg/kg rapamycin, 12 mg/kg stavudine, and CMC-Na groups. Drugs were orally administered to mice for 42 consecutive days. The von Frey filament detection and thermal pain tests were conducted on day 7, 14, 21, 28, 35, and 42 after drug administration. After the last behavioral tests, immunohistochemistry and western blotting assay were used for the measurement of mTOR and other biomarkers. Multivariate analysis of variance was used.@*Results@#The beneficial effects of rapamycin on neuropathic pain were attributed to a reduction in mammalian target of rapamycin sensitive complex 1 (mTORC1)-positive cells (70.80 ± 2.41 vs. 112.30 ± 5.66, F = 34.36, P < 0.01) and mTORC1 activity in the mouse spinal cord. Mechanistic studies revealed that Protein Kinase B (Akt)/mTOR signaling pathway blockade with rapamycin prevented the phosphorylation of mTORC1 in stavudine-intoxicated mice (0.72 ± 0.04 vs. 0.86 ± 0.03, F = 4.24, P = 0.045), as well as decreased the expression of phospho-p70S6K (0.47 ± 0.01 vs. 0.68 ± 0.03, F = 6.01, P = 0.022) and phospho-4EBP1 (0.90 ± 0.04 vs. 0.94 ± 0.06, F = 0.28, P = 0.646).@*Conclusions@#Taken together, these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway. The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic pain.


Subject(s)
Animals , HIV Infections , Drug Therapy , Humans , Male , Mice , Neuralgia , Phosphatidylinositol 3-Kinase , Phosphatidylinositols , Proto-Oncogene Proteins c-akt , Reverse Transcriptase Inhibitors , Pharmacology , Sirolimus , TOR Serine-Threonine Kinases
9.
Article in English | WPRIM | ID: wpr-739494

ABSTRACT

Phosphatidylinositol 3-kinase (PI3K) signaling plays an important role in the regulation of cellular lipid metabolism and non-alcoholic fatty liver disease (NAFLD). However, little is known about the role of the regulatory subunits of PI3K in lipid metabolism and NAFLD. In this study, we characterized the functional role of PIK3R3 in fasting-induced hepatic lipid metabolism. In this study, we showed that the overexpression of PIK3R3 promoted hepatic fatty acid oxidation via PIK3R3-induced expression of PPARα, thus improving the fatty liver phenotype in high-fat diet (HFD)-induced mice. By contrast, hepatic PIK3R3 knockout in normal mice led to increased hepatic TG levels. Our study also showed that PIK3R3-induced expression of PPARα was dependent on HNF4α. The novel PIK3R3-HNF4α-PPARα signaling axis plays a significant role in hepatic lipid metabolism. As the activation of PIK3R3 decreased hepatosteatosis, PIK3R3 can be considered a promising novel target for developing NAFLD and metabolic syndrome therapies.


Subject(s)
Animals , Diet, High-Fat , Fatty Liver , Lipid Metabolism , Mice , Non-alcoholic Fatty Liver Disease , Phenotype , Phosphatidylinositol 3-Kinase
10.
Article in English | WPRIM | ID: wpr-812052

ABSTRACT

The aim of the present study was to investigate the protective effects and underlying mechanisms of Garcinia xanthochymus, a perennial medicinal plant native to Yunnan, China, against HO-induced oxidative damage in rat pheochromacytoma PC12 cells. Preincubation of PC12 cells with fruit EtOAc fraction (fruit-EFr., 12.5-50 µmol·L) of G. xanthochymus for 24 h prior to HO exposure markedly improved cell viability and increased the activities of antioxidant enzymes (superoxide dismutase, catalase, and heme oxygenase-1 [HO-1]), prevented lactate dehydrogenase release and lipid peroxidation malondialdehyde production, attenuated the decrease of matrix metalloproteinases (MMP), and scavenged reactive oxygen species (ROS). Fruit-EFr. also reduced BAX and cytochrome C expression and improved BCL-2 expression, thereby decreasing the ratio of BAX to BCL-2. Fruit-EFr. activated the nuclear translocation of NRF2 to increase HO-1 and induced the phosphorylation of AKT. Its cytoprotective effect was abolished by LY294002, a specific inhibitor of PI3K. Taken together, the above findings suggested that fruit-EFr.of G. xanthochymus could enhance cellular antioxidant defense capacity, at least in part, through upregulating HO-1 expression and activating the PI3K/AKT pathway and that it could suppress HO-induced oxidative damage via PI3K/AKT and NRF2/HO-1 signaling pathways.


Subject(s)
Animals , Antioxidants , Metabolism , Pharmacology , Apoptosis , Biological Transport , Cell Survival , Cytochromes c , Metabolism , Fruit , Garcinia , Heme Oxygenase-1 , Metabolism , Hydrogen Peroxide , NF-E2-Related Factor 2 , Metabolism , Oxidative Stress , PC12 Cells , Phosphatidylinositol 3-Kinase , Metabolism , Phosphatidylinositol 3-Kinases , Phosphorylation , Plant Extracts , Pharmacology , Protective Agents , Pharmacology , Proto-Oncogene Proteins c-akt , Metabolism , Proto-Oncogene Proteins c-bcl-2 , Metabolism , Rats , Signal Transduction , bcl-2-Associated X Protein , Metabolism
11.
Article in English | WPRIM | ID: wpr-728754

ABSTRACT

Anesthetics are used extensively in surgeries and related procedures to prevent pain. However, there is some concern regarding neuronal degeneration and cognitive deficits arising from regular anesthetic exposure. Recent studies have indicated that brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are involved in learning and memory processes. Genistein, a plant-derived isoflavone, has been shown to exhibit neuroprotective effects. The present study was performed to examine the protective effect of genistein against isoflurane-induced neurotoxicity in rats. Neonatal rats were exposed to isoflurane (0.75%, 6 hours) on postnatal day 7 (P7). Separate groups of rat pups were orally administered genistein at doses of 20, 40, or 80 mg/kg body weight from P3 to P15 and then exposed to isoflurane anesthesia on P7. Neuronal apoptosis was detected by TUNEL assay and FluoroJade B staining following isoflurane exposure. Genistein significantly reduced apoptosis in the hippocampus, reduced the expression of proapoptotic factors (Bad, Bax, and cleaved caspase-3), and increased the expression of Bcl-2 and Bcl-xL. RT-PCR analysis revealed enhanced BDNF and TrkB mRNA levels. Genistein effectively upregulated cAMP levels and phosphorylation of CREB and TrkB, leading to activation of cAMP/CREB-BDNF-TrkB signaling. PI3K/Akt signaling was also significantly activated. Genistein administration improved general behavior and enhanced learning and memory in the rats. These observations suggest that genistein exerts neuroprotective effects by suppressing isoflurane-induced neuronal apoptosis and by activating cAMP/CREB-BDNF-TrkB-PI3/Akt signaling.


Subject(s)
Anesthesia , Anesthetics , Animals , Apoptosis , Body Weight , Brain-Derived Neurotrophic Factor , Cognition Disorders , Cyclic AMP Response Element-Binding Protein , Genistein , Hippocampus , In Situ Nick-End Labeling , Isoflurane , Learning , Memory , Neurons , Neuroprotective Agents , Phosphatidylinositol 3-Kinase , Phosphorylation , Rats , RNA, Messenger , Spatial Learning
12.
Chinese Medical Journal ; (24): 854-858, 2017.
Article in English | WPRIM | ID: wpr-266898

ABSTRACT

<p><b>BACKGROUND</b>Recombinant human-erythropoietin (rh-EPO) has therapeutic efficacy for premature infants with brain damage during the active rehabilitation and anti-inflammation. In the present study, we found that the rh-EPO was related to the promotion of neovascularization. Our aim was to investigate whether rh-EPO augments neovascularization in the neonatal rat model of premature brain damage through the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway.</p><p><b>METHODS</b>Postnatal day 5 (PD5), rats underwent permanent ligation of the right common carotid artery and were exposed to hypoxia for 2 h. All the rat pups were randomized into five groups as follows: (1) control group; (2) hypoxia-ischemic (HI) group; (3) HI + LY294002 group; (4) HI + rh-EPO group; and (5) HI + rh-EPO + LY294002 group. The phospho-Akt protein was tested 90 min after the whole operation, and CD34, vascular endothelial growth factor receptor 2 (VEGFR2), and vascular endothelial growth factor (VEGF) were also tested 2 days after the whole operation.</p><p><b>RESULTS</b>In the hypoxic and ischemic zone of the premature rat brain, the rh-EPO induced CD34+ cells to immigrate to the HI brain zone (P < 0.05) and also upregulated the VEGFR2 protein expression (P < 0.05) and VEGF mRNA level (P < 0.05) through the PI3K/Akt (P < 0.05) signaling pathway when compared with other groups.</p><p><b>CONCLUSIONS</b>The rh-EPO treatment augments neovascularization responses in the neonatal rat model of premature brain damage through the PI3K/Akt signaling pathway. Besides, the endogenous EPO may exist in the HI zone of rat brain and also has neovascularization function through the PI3K/Akt signaling pathway.</p>


Subject(s)
Animals , Animals, Newborn , Antigens, CD34 , Metabolism , Brain , Metabolism , Pathology , Disease Models, Animal , Erythropoietin , Genetics , Metabolism , Therapeutic Uses , Female , Humans , Hypoxia-Ischemia, Brain , Drug Therapy , Metabolism , Neovascularization, Physiologic , Phosphatidylinositol 3-Kinase , Metabolism , Pregnancy , Proto-Oncogene Proteins c-akt , Metabolism , Rats , Rats, Sprague-Dawley , Recombinant Proteins , Genetics , Metabolism , Therapeutic Uses , Signal Transduction , Vascular Endothelial Growth Factor A , Genetics , Vascular Endothelial Growth Factor Receptor-2 , Metabolism
13.
Journal of Breast Cancer ; : 321-326, 2017.
Article in English | WPRIM | ID: wpr-194963

ABSTRACT

Activation of the mammalian target of rapamycin (mTOR) signaling pathway is an important mechanism of resistance to endocrine therapy in breast cancer. Everolimus, an mTOR inhibitor, has been shown to increase the efficacy of endocrine therapy and overcome resistance to endocrine therapies. Clinical studies have suggested that everolimus combined with endocrine therapy prolongs progression-free survival in hormone receptor-positive breast cancer patients. However, because breast cancer includes a group of highly heterogeneous tumors, patients may have different responses to everolimus. Therefore, finding biomarkers that can predict a patient's positive response or resistance to everolimus is critical. Numerous preclinical studies have shown that PIK3CA/PTEN mutations are predictive of sensitivity to everolimus; however, clinical trials have not confirmed the correlation between mutation status and clinical response. KRAS or BRAF mutations can bypass the phosphatidylinositol 3-kinase pathway; therefore, mutations in KRAS or BRAF may lead to resistance to mTOR inhibitors, and preclinical studies have shown that PIK3CA mutant cells which also contain KRAS mutations are resistant to everolimus. However, there are no clinical data in breast cancer patients to support this conclusion. Therefore, large-scale clinical studies are needed to identify biomarkers of efficacy and resistance to everolimus.


Subject(s)
Biomarkers , Breast Neoplasms , Breast , Disease-Free Survival , Everolimus , Humans , Phosphatidylinositol 3-Kinase , Sirolimus
14.
Article in English | WPRIM | ID: wpr-201473

ABSTRACT

We have previously shown that the specific phosphatidylinositol 3-kinase inhibitor LY294002 (LY29), and its inactive analog LY303511 (LY30), inhibit a monocyte chemoattractant protein-1 (MCP-1) expression in human umbilical vein endothelial cells; these results suggest the potential of LY30 as an anti-inflammatory drug. In this study, we determined the effects of LY30 on the production of various inflammatory cytokines in human macrophagic THP-1 cells which were stimulated with lipopolysaccharide (LPS). LY30 selectively suppressed the mRNA expression of IL-12 p40, TNF-α, and MCP-1 without affecting the expression of IL-1α, IL-6, and IL-8. Inhibition of the production of IL-12 and TNF-α by LY30 was also demonstrated using ELISA assays. In order to elucidate the mechanisms of the action of LY30, we examined the role played by the mitogen-activated protein kinases and the key transcription factors, AP-1 and NF-κB in LPS-stimulated THP-1 cells. The results revealed that LY30 inhibited LPS-induced activation of ERK, but not p38 or JNK. Furthermore, the AP-1 DNA binding activity was suppressed by LY30 based upon the dosage, whereas NF-κB DNA binding was not affected. These results suggest that LY30 selectively inhibits cytokine production in the LPS-stimulated macrophagic THP-1 cells by downregulating the activation of ERK and AP-1.


Subject(s)
Chemokine CCL2 , Cytokines , DNA , Enzyme-Linked Immunosorbent Assay , Human Umbilical Vein Endothelial Cells , Humans , Interleukin-12 , Interleukin-6 , Interleukin-8 , Mitogen-Activated Protein Kinases , Phosphatidylinositol 3-Kinase , RNA, Messenger , Transcription Factor AP-1 , Transcription Factors
15.
Article in English | WPRIM | ID: wpr-29645

ABSTRACT

BACKGROUND AND PURPOSE: Neurogenesis in the adult brain is important for memory and learning, and the alterations in neural stem cells (NSCs) may be an important aspect of Alzheimer's disease (AD) pathogenesis. The phosphatidylinositol 3-kinase (PI3K) pathway has been suggested to have an important role in neuronal cell survival and is highly involved in adult neurogenesis. Candesartan is an angiotensin II receptor antagonist used for the treatment of hypertension and several studies have reported that it also has some neuroprotective effects. We investigated whether candesartan could restore the amyloid-β(25–35) (Aβ₂₅₋₃₅) oligomer-inhibited proliferation of NSCs by focusing on the PI3K pathway. METHODS: To evaluate the effects of candesartan on the Aβ₂₅₋₃₅ oligomer-inhibited proliferation of NSCs, the NSCs were treated with several concentrations of candesartan and/or Aβ₂₅₋₃₅ oligomers, and MTT assay and trypan blue staining were performed. To evaluate the effect of candesartan on the Aβ-inhibited proliferation of NSCs, we performed a bromodeoxyuridine (BrdU) labeling assay. The levels of p85α PI3K, phosphorylated Akt (pAkt) (Ser473), phosphorylated glycogen sinthase kinase-3β (pGSK-3β) (Ser9), and heat shock transcription factor-1 (HSTF-1) were analyzed by Western blotting. RESULTS: The BrdU assays demonstrated that NSC proliferation decreased with Aβ25-35 oligomer treatment; however, a combined treatment with candesartan restored it. Western blotting displayed that candesartan treatment increased the expression levels of p85α PI3K, pAkt (Ser473), pGSK-3β (Ser9), and HSTF. The NSCs were pretreated with a PI3K inhibitor, LY294002; the effects of candesartan on the proliferation of NSCs inhibited by Aβ₂₅₋₃₅ oligomers were almost completely blocked. CONCLUSIONS: Together, these results suggest that candesartan restores the Aβ₂₅₋₃₅ oligomer-inhibited proliferation of NSCs by activating the PI3K pathway.


Subject(s)
Adult , Alzheimer Disease , Amyloid , Blotting, Western , Brain , Bromodeoxyuridine , Cell Survival , Glycogen , Hot Temperature , Humans , Hypertension , Learning , Memory , Neural Stem Cells , Neurogenesis , Neurons , Neuroprotective Agents , Phosphatidylinositol 3-Kinase , Phosphatidylinositols , Receptors, Angiotensin , Shock , Trypan Blue
16.
Hanyang Medical Reviews ; : 18-24, 2017.
Article in English | WPRIM | ID: wpr-91139

ABSTRACT

Alzheimer's disease (AD) is the most common form of dementia. Although uncountable clinical trials have been done to develop the treatment of AD, there are a couple of drugs that can be used only for symptomatic treatment. Therefore, many studies based on the amyloid cascade hypothesis and the tauopathy hypothesis are still ongoing. After the failure of numerous huge Phase III clinical trials, arguments on those hypotheses have arisen and efforts to establish other possible therapeutic strategies based on diverse plausible mechanisms associated with AD have been done as well. One of the new therapeutic targets for AD is the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. In this review, questions on the two hypotheses, the definition of the PI3K/AKT pathway, the relationship between the pathway and AD, and the possibility of the modulation of the pathway as a new therapeutic strategy for AD will be discussed briefly.


Subject(s)
Alzheimer Disease , Amyloid , Dementia , Phosphatidylinositol 3-Kinase , Tauopathies
17.
Article in English | WPRIM | ID: wpr-20676

ABSTRACT

BACKGROUND/OBJECTIVES: Recent living condition improvements, changes in dietary habits, and reductions in physical activity are contributing to an increase in metabolic syndrome symptoms including diabetes and obesity. Through such societal developments, humankind is continuously exposed to metabolic diseases such as diabetes, and the number of the victims is increasing. This study investigated Cordyceps militaris water extract (CMW)-induced glucose uptake in HepG2 cells and the effect of CMW treatment on glucose metabolism. MATERIALS/METHODS: Colorimetric assay kits were used to determine the glucokinase (GK) and pyruvate dehydrogenase (PDH) activities, glucose uptake, and glycogen content. Either RT-PCR or western blot analysis was performed for quantitation of glucose transporter 2 (GLUT2), hepatocyte nuclear factor 1 alpha (HNF-1α), phosphatidylinositol 3-kinase (PI3k), protein kinase B (Akt), phosphorylated AMP-activated protein kinase (pAMPK), phosphoenolpyruvate carboxykinase, GK, PDH, and glycogen synthase kinase 3 beta (GSK-3β) expression levels. The α-glucosidase inhibitory activities of acarbose and CMW were evaluated by absorbance measurement. RESULTS: CMW induced glucose uptake in HepG2 cells by increasing GLUT2 through HNF-1α expression stimulation. Glucose in the cells increased the CMW-induced phosphorylation of AMPK. In turn, glycolysis was stimulated, and glyconeogenesis was inhibited. Furthermore, by studying the mechanism of action of PI3k, Akt, and GSK-3β, and measuring glycogen content, the study confirmed that the glucose was stored in the liver as glycogen. Finally, CMW resulted in a higher level of α-glucosidase inhibitory activity than that from acarbose. CONCLUSION: CMW induced the uptake of glucose into HepG2 cells, as well, it induced metabolism of the absorbed glucose. It is concluded that CMW is a candidate or potential use in diabetes prevention and treatment.


Subject(s)
Acarbose , alpha-Glucosidases , AMP-Activated Protein Kinases , Blotting, Western , Cordyceps , Feeding Behavior , Glucokinase , Glucose Transport Proteins, Facilitative , Glucose , Glycogen , Glycogen Synthase Kinase 3 , Glycolysis , Hep G2 Cells , Hepatocyte Nuclear Factor 1-alpha , Hypoglycemic Agents , Liver , Metabolic Diseases , Metabolism , Motor Activity , Obesity , Oxidoreductases , Phosphatidylinositol 3-Kinase , Phosphoenolpyruvate , Phosphorylation , Proto-Oncogene Proteins c-akt , Pyruvic Acid , Social Conditions , Water
18.
Article in English | WPRIM | ID: wpr-25937

ABSTRACT

Nerve growth factor (NGF) is known to regulate both cancer cell survival and death signaling, depending on the cellular circumstances, in various cell types. In this study, we showed that NGF strongly upregulated the protein level of tropomyosin-related kinase A (TrkA) in TrkA-inducible SK-N-MC cancer cells, resulting in increases in various TrkA-dependent cellular processes, including the phosphorylation of c-Jun N-terminal kinase (JNK) and caspase-8 cleavage. In addition, NGF enhanced TrkA-induced morphological changes and cell death, and this effect was significantly suppressed by the JNK inhibitor SP600125, but not by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. To investigate novel targets associated with the enhancement of TrkA-induced SK-N-MC cell death caused by NGF, we performed Coomassie Brilliant Blue staining and two-dimensional (2D) proteomic analysis in TrkA-inducible SK-N-MC cells. We identified 31 protein spots that were either greatly upregulated or downregulated by TrkA during NGF treatment using matrix-associated laser desorption/ionization time of flight/time of flight mass spectrometry, and we analyzed the effects of SP600125 and wortmannin on the spots. Interestingly, 11 protein spots, including heterogeneous nuclear ribonucleoprotein K (hnRNP K), lamin B1 and TAR DNA-binding protein (TDP43), were significantly influenced by SP600125, but not by wortmannin. Moreover, the NGF/TrkA-dependent inhibition of cell viability was significantly enhanced by knockdown of hnRNP K using small interfering RNA, demonstrating that hnRNP K is a novel target associated with the regulation of TrkA-dependent SK-N-MC cancer cell death enhanced by NGF.


Subject(s)
Caspase 8 , Cell Death , Cell Survival , Heterogeneous-Nuclear Ribonucleoprotein K , JNK Mitogen-Activated Protein Kinases , Mass Spectrometry , Nerve Growth Factor , Phosphatidylinositol 3-Kinase , Phosphorylation , Phosphotransferases , RNA, Small Interfering
19.
Article in English | WPRIM | ID: wpr-89894

ABSTRACT

BACKGROUND: Despite recent advances in therapy, colorectal cancer still has a grim prognosis. Although licorice has been used in East Asian traditional medicine, the molecular properties of its constituents including dehydroglyasperin D (DHGA-D) remain unknown. We sought to evaluate the inhibitory effect of DHGA-D on colorectal cancer cell proliferation and identify the primary signaling molecule targeted by DHGA-D. METHODS: We evaluated anchorage-dependent and -independent cell growth in HT-29 human colorectal adenocarcinoma cells. The target protein of DHGA-D was identified by Western blot analysis with a specific antibody, and direct interaction between DHGA-D and the target protein was confirmed by kinase and pull-down assays. Cell cycle analysis by flow cytometry and further Western blot analysis was performed to identify the signaling pathway involved. RESULTS: DHGA-D significantly suppressed anchorage-dependent and -independent HT-29 colorectal cancer cell proliferation. DHGA-D directly suppressed phosphatidylinositol 3-kinase (PI3K) activity and subsequent Akt phosphorylation and bound to the p110 subunit of PI3K. DHGA-D also significantly induced G1 cell cycle arrest, together with the suppression of glycogen synthase kinase 3β and retinoblastoma phosphorylation and cyclin D1 expression. CONCLUSIONS: DHGA-D has potent anticancer activity and targets PI3K in human colorectal adenocarcinoma HT-29 cells. To our knowledge, this is the first report to detail the molecular basis of DHGA-D in suppressing colorectal cancer cell growth.


Subject(s)
Adenocarcinoma , Blotting, Western , Cell Cycle , Cell Proliferation , Colorectal Neoplasms , Cyclin D1 , Flow Cytometry , G1 Phase Cell Cycle Checkpoints , Glycogen Synthase Kinases , Glycyrrhiza , HT29 Cells , Humans , Medicine, East Asian Traditional , Phosphatidylinositol 3-Kinase , Phosphatidylinositols , Phosphorylation , Phosphotransferases , Prognosis , Retinoblastoma
20.
Article in English | WPRIM | ID: wpr-84889

ABSTRACT

BACKGROUND: Cognitive impairment and brain damage in diabetes is suggested to be associated with hypoglycemia. The mechanisms of hypoglycemia-induced neural death and apoptosis are not clear and reperfusion injury may be involved. Recent studies show that glucose deprivation/reperfusion induced more neuronal cell death than glucose deprivation itself. The forkhead box O (FOXO) transcription factors are implicated in the regulation of cell apoptosis and survival, but their role in neuronal cells remains unclear. We examined the role of FOXO transcription factors and the involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt and apoptosis-related signaling pathways in PC-12 cells exposed to repeated glucose deprivation/reperfusion. METHODS: PC-12 cells were exposed to control (Dulbecco's Modified Eagle Medium [DMEM] containing 25 mM glucose) or glucose deprivation/reperfusion (DMEM with 0 mM glucose for 6 hours and then DMEM with 25 mM glucose for 18 hours) for 5 days. MTT assay and Western blot analysis were performed for cell viability, apoptosis, and the expression of survival signaling pathways. FOXO3/4',6-diamidino-2-phenylindole staining was done to ascertain the involvement of FOXO transcription factors in glucose deprivation/reperfusion conditions. RESULTS: Compared to PC-12 cells not exposed to hypoglycemia, cells exposed to glucose deprivation/reperfusion showed a reduction of cell viability, decreased expression of phosphorylated Akt and Bcl-2, and an increase of cleaved caspase-3 expression. Of note, FOXO3 protein was localized in the nuclei of glucose deprivation/reperfusion cells but not in the control cells. CONCLUSION: Repeated glucose deprivation/reperfusion caused the neuronal cell death. Activated FOXO3 via the PI3K/Akt pathway in repeated glucose deprivation/reperfusion was involved in genes related to apoptosis.


Subject(s)
Apoptosis , Blotting, Western , Brain , Caspase 3 , Cell Death , Cell Survival , Cognition Disorders , Eagles , Glucose , Hypoglycemia , Neurons , Phosphatidylinositol 3-Kinase , Reperfusion , Reperfusion Injury , Transcription Factors
SELECTION OF CITATIONS
SEARCH DETAIL