OBJECTIVE: To investigate the effect of Akt2 inhibitor on macrophage polarization in the periapical tissue in a rat model of periapical inflammation. METHODS: Rat models of periapical inflammation were established in 28 normal SD rats by opening the pulp cavity of the mandibular first molars, followed by injection of normal saline and Akt2 inhibitor into the left and right medullary cavities, respectively. Four rats without any treatment served as the healthy control group. At 7, 14, 21 and 28 days after modeling, 7 rat models and 1 control rat were randomly selected for observation of inflammatory infiltration in the periapical tissues by X-ray and HE staining. Immunohistochemistry was used to detect the expression and localization of Akt2, macrophages and the inflammatory mediators. RT-PCR was performed to detect the mRNA expressions of Akt2, CD86, CD163, inflammatory mediators, miR-155-5p and C/EBPβ to analyze the changes in macrophage polarization. RESULTS: X-ray and HE staining showed that periapical inflammation was the most obvious at 21 days after modeling in the rats. Immunohistochemistry and RT-PCR showed that compared with those in the control rats, the expressions of Akt2, CD86, CD163, miR-155-5p, C/EBPβ, and IL-10 increased significantly in the rat models at 21 days (P < 0.05). Compared with saline treatment, treatment with the Akt2 inhibitor significantly decreased the expression levels of Akt2, CD86, miR-155-5p and IL-6 and the ratio of CD86⁺M1/CD163⁺M2 macrophages (P < 0.05) and increased the expression levels of CD163, C/EBPβ and IL-10 in the rat models (P < 0.05). CONCLUSION Inhibition of Akt2 can delay the progression of periapical inflammation in rats and promote M2 macrophage polarization in the periapical inflammatory microenvironment possibly by reducing miR-155-5p expression and activating the expression of C/EBPβ in the Akt signaling pathway.
Rats ; Animals ; Proto-Oncogene Proteins c-akt/metabolism* ; MicroRNAs/genetics* ; Interleukin-10 ; Rats, Sprague-Dawley ; Macrophages/metabolism* ; Inflammation/metabolism*

BACKGROUNDTransient sublethal ischemia is known as ischemic preconditioning, which enables cells and tissues to survive subsequent prolonged lethal ischemic injury. Ischemic preconditioning exerts neuroprotection through phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Cbl-b belongs to the Casitas B-lineage lymphoma (Cbl) family, and it can regulate the cell signal transduction.The roles of ubiquitin ligase Cbl-b and PI3K/Akt pathway and the relationship between them in oxygen-glucose deprivation preconditioning (OGDPC) in PC12 cells were investigated in the present study.

METHODSOxygen and glucose deprivation (OGD) model in PC12 cells was used in the present study. The 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, nuclear staining with Hoechst 33258, and Western blotting were applied to explore the roles of Cbl-b and PI3K/Akt pathway and the relationship between them in OGDPC in PC12 cells.

RESULTSCell viability was significantly changed by OGD and OGDPC. OGD significantly decreased cell viability compared with the control group (P < 0.05), and preconditioning could rescue this damage was demonstrated by the increase of cell viability (P < 0.05). The expression of Cbl-b was significantly increased after OGD treatment. However, the activation of Akt and GSK3β was greatly inhibited. Preconditioning could inhibit the increase of Cbl-b caused by OGD and increase the activation of Akt and GSK3β. LY294002, a specific inhibitor of PI3K, could effectively inhibit the increase of Akt and GSK3β after preconditioning treatment. It partly inhibited the decrease of Cbl-b expression after preconditioning treatment.

CONCLUSIONUbiquitin ligase Cbl-b and PI3K/Akt pathway are differently involved in OGDPC in PC12 cells.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Animals ; Cell Survival ; Glucose ; deficiency ; Ischemic Preconditioning ; Oxygen ; metabolism ; PC12 Cells ; Phosphatidylinositol 3-Kinase ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Proto-Oncogene Proteins c-cbl ; genetics ; metabolism ; Rats ; Signal Transduction ; physiology

OBJECTIVE: To observe the effects of down-regulation of long non-coding RNA HOX antisense intergenic RNA myeloid 1 (LncRNA-HOTAIRM1) to the proliferation and apoptosis of Jurkat in human leukemia T lymphocytes, and explore its mechanism. METHODS: Jurkat cells were cultured in vitro and randomly divided into control group, HOTAIRM1 siRNA-NC group and HOTAIRM1 siRNA group; the expressions of LncRNA-HOTAIRM1 mRNA, KIT receptor tyrosine kinase (KIT) mRNA and serine threonine kinase (AKT) mRNA in Jurkat cells were detected by real-time fluorescence quantification (RT-qPCR); the proliferation of Jurkat cells in each groups was detected by CCK-8 method; the apoptosis of Jurkat cells in each groups was detected by Annexin V-FITC/PI double staining; the expressions of KIT, AKT, p-KIT, p-AKT, B-lymphoma-2 gene (BCL-2) and Caspase-3 were detected by Western blot. RESULTS: Compared with the cells in the control group and HOTAIRM1 siRNA-NC group, the expression level of LncRNA-HOTAIRM1 mRNA, cell survival rate, expression levels of KIT mRNA, AKT mRNA, p-KIT, p-AKT and BCL-2 proteins in Jurkat cells in HOTAIRM1 siRNA group were significantly lower (P<0.05), while the expression level of Cleared Caspase-3 protein and Jurkat cell apoptosis rate were significantly higher (P<0.05). CONCLUSION LncRNA-HOTAIRM1 may inhibit Jurkat cell proliferation and induce apoptosis through KIT/AKT signaling pathway.
Apoptosis ; Cell Proliferation ; Down-Regulation ; Humans ; Jurkat Cells ; Proto-Oncogene Proteins c-akt/metabolism* ; RNA, Long Noncoding/genetics*

This study was aimed to investigate the effect of SU11248 on proliferation and apoptosis of leukemia cell line K562 in vitro and its mechanism. The inhibitory effect of 3.2 µg/ml SU11248 on K562 proliferation was tested by MTT assay. The ability of SU11248 to induce apoptosis of K562 cells was examined by TUNEL and DNA ladder. The expression of C-MYC, hTERT and BCR-ABL mRNA in K562 cells was detected by RT-PCR. The protein expression of Akt and p-Akt in K562 cells was detected by Western blot. The results showed that the proliferation of K562 cells was obviously inhibited by 3.2 µg/ml SU11248 in a time-dependent manner. SU11248 could induce K562 cells apoptosis in dose-and time-dependent manner. The mRNA expression of C-MYC, hTERT and BCR-ABL was reduced significantly by SU11248 in a time-dependent manner (P < 0.05). Western blot detection showed that the expression of p-Akt protein in K562 cells decreased in dose-and time-dependent manner after SU11248 treatment, but the expression of Akt was not significantly changed. It is concluded that SU11248 can inhibit the growth of K562 cells efficiently through inducing apoptosis, its mechanism may be closely relate with the expression down-regulation of C-MYC, hTERT, BCR-ABL and the inhibition of Akt phosphorylation.
Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Fusion Proteins, bcr-abl ; metabolism ; Humans ; Indoles ; pharmacology ; K562 Cells ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; Pyrroles ; pharmacology ; RNA, Messenger ; genetics ; Telomerase ; metabolism

The aim of this study was to investigate apoptotic effect of 2-methoxyestradiol (2-ME2) on K562 cells and its mechanism. K562 cells were treated with different concentrations of 2-ME2. MTT assay was used to examine the effect inducing growth inhibition. DNA fragmentation assay and Annexin V-FITC/PI staining were used to detect the effect of apoptosis. The change of mitochondrial transmembrane potential was analyzed by flow cytometry. The expressions of related gene mRNA and/or proteins were detected by RT-PCR and Western blot respectively. The results indicated that the 2-ME2 inhibited proliferation of K562 cells in a time- and dose-dependent manners and the concentration of 50% growth inhibition (IC(50)) was 2 micromol/L at 48 hours. 2-ME2 induced DNA ladder and significantly increased apoptosis in K562 cells when exposed to 2 micromol/L of 2-ME2 for 24, 48 and 72 hours, the result of Annexin-V/PI staining showed that rates of the apoptotic cells were 13.78%, 22.32% and 29.43% respectively, which was remarkably higher than that of control (1.78%) (p < 0.05). The FCM analysis showed that the mitochondrial transmembrane potential in K562 cells lowered after exposed to 1, 2 and 4 micromol/L of 2-ME2 for 24 hours. 2-ME2 down-regulated the expression of bcr/abl and bcl-2, up-regulated the expression of bax mRNA, and down-regulated protein expressions of bcl-2, procaspase-3, procaspase-9, PARP (116 kD) and p-Akt, and up-regulated expression of cytoplasmic Cyto-C and PARP 85 kD apoptosis-related cleavage fragment protein, but had no effect on total Akt protein in K562 cells after treated with 2 micromol/L of 2-ME2 for 24, 48 and 72 hours. It is concluded that the 2-ME2 can induce the apoptosis and inhibit the proliferation of K562 cells by increasing the ratio of bax/bcl-2, reducing the mitochondrial transmembrane potential, releasing cytochrome C to cytoplasm, initiating the mitochondrial apoptosis pathway and leading in turn to caspase-3 activation. These findings suggest that interfere PI3K/Akt signal pathway via down-regulating the expression of bcr/abl mRNA is implicated in the effect of 2-ME2 on K562 cells.
Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Cytochromes c ; metabolism ; Down-Regulation ; Estradiol ; analogs & derivatives ; pharmacology ; Humans ; K562 Cells ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA, Messenger ; genetics

OBJECTIVE: To investigate the regulatory role of α-1, 6-fucosyltransferase (FUT8) in TGF-β1-induced proliferation, migration and fibrosis of human embryonic lung fibroblasts (MRC-5 cells) and explore the underlying molecular mechanism. METHODS: C57/BL6 mice were randomized into 4 groups for treatment with saline (control group), bleomycin, bleomycin+sh-NC or bleomycin+sh-FUT8, and pulmonary fibrosis was observed using Masson staining.MRC-5 cells were transfected with si-NC, FUT8 siRNA (si-FUT8), or both si-FUT8 and a galectin-3(Gal-3) overexpression plasmid (pcDNA3.1-Gal) prior to TGF-β1 treatment, and the changes in cell proliferation and migration were assessed using CCK-8 assay, BrdU assay, and wound healing assay; the changes in the expression levels of α-SMA, collagen I (COLIA1) and extracellular matrix fibronectin (FN) were detected with real-time quantitative PCR (RT-qPCR) and Western blotting.The interaction of FUT8 and Gal-3 was tested using coimmunoprecipitation (Co-IP) assay, and the effect of FUT8 silencing on Gal-3 and FAK/Akt signaling pathways was analyzed. RESULTS: FUT8 knockdown significantly reduced bleomycin-induced extracellular collagen deposition in the lung tissues of the mice.Silencing FUT8 obviously inhibited cell proliferation (P < 0.05) and migration mediated by TGF-β1.FUT8 knockdown down-regulated the mRNA and protein levels of α-SMA, COLIA1 and FN (P < 0.05) in the cells.Coimmunoprecipitation analysis showed that FUT8 interacted with Gal-3.Silencing FUT8 significantly down-regulated Gal-3 expression and inhibited the activation of the FAK/Akt signaling pathway (P < 0.05).Overexpression of Gal-3 obviously reversed the effects of FUT8 silencing on cell proliferation, migration and fibrosis (P < 0.05). CONCLUSION FUT8 regulates TGF-β1-induced proliferation, migration and fibrosis of MRC-5 cells by modulating Gal-3 expression, in which the FAK/Akt pathway may play a role.
Animals ; Bleomycin/metabolism* ; Fibroblasts/metabolism* ; Fibrosis ; Fucosyltransferases/metabolism* ; Galectin 3/genetics* ; Humans ; Lung/metabolism* ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Transforming Growth Factor beta1/metabolism*

Retinol-binding protein 4 (RBP4) is adipocyte-derived secreted adipokines and elevated RBP4 expression level was closely related to insulin resistance and type II diabetes mellitus. However, the exact mechanisms are unknown. To clarify the mechanism, RBP4 lentivirus particles were packaged to infect porcine preadipocytes. Then porcine preadipocytes were activated by insulin or induced model of insulin resistance. RBP4 interference efficiency and the gene expression of each treatment groups in PI3K/Akt pathways were examined by QRT-PCR and Western blotting. The result shows that RBP4 mRNA and protein expressions were suppressed more than 60% (P < 0.01). Furthermore, no matter under insulin stimulation or insulin resistance, RBP4 knockdown significantly increased the mRNA expressions of AKT2, PI3K, GLUT4 and IRS1 compared with the control. The protein phosphorylate levels of AKT2, PI3K, IRS1 arised, meanwhile enhanced the AKT2, PI3K, GLUT4 total protein expressions. Collectively, knockdown of RBP4 increased the insulin sensitivity through upregulated PI3K/Akt pathways related factors' expression and phosphorylation in porcine adipocytes. This research will provide a new idea to treat insulin resistance related diseases.
Adipocytes ; metabolism ; Animals ; Gene Knockdown Techniques ; Insulin Resistance ; physiology ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Retinol-Binding Proteins, Plasma ; genetics ; pharmacology ; Signal Transduction ; Swine

OBJECTIVETo study the expressions of Erk1/2 and PKB/Akt in the corpus cavernosum of castrated rats and investigate their action mechanism in the development of erectile dysfunction (ED) after castration.

METHODSWe randomly divided 20 eight-week-old SD rats into Groups A (sham-operation) and B (castration), and, 4 weeks after the operation, determined the level of serum testosterone (T) and the expressions of P-Erk1/2 and P-PKB/Akt proteins (integrated optical density/area, IA/area) and those of Erk1/2 and PKB/Akt mRNA (Marker: GAPDH) in the corpus cavernosum of the rats by immunohistochemical staining and RT-PCR.

RESULTSFour weeks after the operation, the serum T level was significantly decreased in Group B in comparison with A ([10.090 +/- 3. 026] nmol/L versus [1.339 +/- 0.642] nmol/L, P < 0.05). Erk1/2 and PKB/Akt expressed in the corpus cavernosum of both groups of rats. The expressions of Erk1 and Erk2 mRNA and P-Erk1/2 were significantly higher in Group B (0. 840 +/- 0.062, 0.876 +/- 0.141 and 0.142 +/- 0.020) than in A (0.479 +/- 0.090, 0.599 +/- 0.100 and 0.119 +/- 0.029) (P < 0.05). But no statistically significant differences were found in the expressions of PKB/Akt mRNA and P-PKB/Akt between Groups B (0.974 +/- 0.040 and 0.164 +/- 0.036) and A (0.942 +/- 0.054 and 0.162 +/- 0.025) (P < 0.05).

CONCLUSIONErk1/2 and PKB/Akt expressed in the penile tissues of both castrated and sham-operation rats. The increased expression of P-Erk1/2 in the corpus cavernosum may be involved in the development of ED in castrated rats.

Animals ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Male ; Orchiectomy ; Penis ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

The study was aimed to explore the correlation of expression of pten mRNA and PTEN protein with AKT phosphorylation levels in various types of leukemia and to elucidate its role in the pathogenesis of leukemia so as to provide some evidence for using PI3K/AKT pathway inhibitors in future. 128 de novo leukemia patients were enrolled in this study, including 61 AML cases, 27 ALL cases, 24 CML cases, and 16 CLL cases. 21 volunteers were selected as normal control. The RT-PCR and Western blot were used to assay the expressions of pten mRNA, PTEN protein, and P-AKT protein in Jurkat cells, bone marrow mononuclear cells of patients respectively. The results showed that the expressions of pten mRNA and PTEN protein in Jurkat cells were lower than that in normal control group; the expression of pten mRNA in AML group was lower than that in normal control group, but the difference was not significant (p=0.274); the expressions of pten mRNA in ALL, CML, CLL each group were lower than that in normal control group, and the difference was significant (p<0.05). Compared with normal control group, the expression of PTEN protein was lower and the expression of P-AKT protein was higher in AML, ALL, CML, CLL each group, the difference were significant (p<0.05). It is concluded that the a lower expression of PTEN protein and higher expression of P-AKT protein may play an important role on leukemia pathogenesis, and inactivation of PTEN protein mainly occurs in the level of protein translation.
Bone Marrow Cells ; metabolism ; Case-Control Studies ; Humans ; Jurkat Cells ; Leukemia ; metabolism ; pathology ; PTEN Phosphohydrolase ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA, Messenger ; genetics

OBJECTIVETo investigate the effect of SHIP gene mutation on the cell cycle and its related gene expression in K562 cells.

METHODSThe recombined green fluorescent protein (GFP) containing FIV-SHIP gene was transfected into K562 cells. The transfection efficiency and cell cycle of K562/SHIP were assessed by flow cytometry (FCM). The proliferation of K562 cells was detected by MTT assay, the mRNA levels of SHIP by real-time fluorescent relative-quantification reverse transcriptional PCR (FQ-PCR), and the protein levels of SHIP, Cyclin D1, p21(WAF1/CIPI) and p27(KIP1) by Western blot.

RESULTSWild type SHIP inhibited K562 cell proliferation and caused a G(0)/G(1) arrest \[(34.2 +/- 7.8)% vs (0.7 +/- 8.3)% (P < 0.01)\]; while the point mutation of SHIP gene did not show such effect. Western blot results showed that the Akt phosphorylation and cyclin D1 expression was significantly decreased (P < 0.01), and the expression of p27(KIP1) and p21(WAF1/CIPI) increased. Site-directed mutation of SHIP gene SH2 domain (TTC-->CTC, Phe-->Leu) did not influence the Akt phosphorylation and cyclins (P > 0.05).

CONCLUSION(1) wtSHIP gene can down-regulate Akt phosphorylation and result in inhibition of cyclin D1 expression, up-regulating p27(KIP1) and p21(WAF1/CIPI) expression, finally leading to the reduction of K562 cell proliferation, and inducing G(0)/G(1) phase arrest. (2) SHIP gene suppresses the proliferation of K562, being dependent on its intact structure and function.

Cell Cycle Proteins ; metabolism ; Humans ; Inositol Polyphosphate 5-Phosphatases ; K562 Cells ; Mutation ; Phosphoric Monoester Hydrolases ; genetics ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Transfection