ObjectiveTo detect the expression level of phosphate and tension homolog deleted on chromsome ten(PTEN) and its downstream signal molecules phosphorylated protein kinase B (p-AKT) in liver cells of rats during intermittent hypoxia,to investigate the effect of PTEN and p-AKT of liver cells on insulin resistance which intermittent hypoxia is relevant. MethodsA total of 24 healthy male SD rats were selected and divided into 3 groups randomly,ie.CIA (chronic intermittent air) group,CIH4 (chronic intermittent hypoxia for 4 weeks) group,and CIH8 (chronic intermittent hypoxia for 8 weeks) group. The fasting blood glucose,fasting insulin,PTEN and p-AKT expressions in the liver cells were detected. The insulin resistance was evaluated systematically by the insulin sensitive index (ISI) and homeostasis model assessment of insulin resistance (HOMA-IR). Average gray value was used to represent the protein expressions of PTEN and p-AKT. ResultsCompared with CIA group,the decline of ISI in CIH4 group and CIH8 group was significant (P<0.05). Furthermore,the decline in CIH8 group was more significant than that in CIH4 group (P<0.05). Compared with CIA group,the rise of HOMA-IR in CIH4 and CIH8 groups was statistically significant (P<0.05). In addition,the rise in CIH8 group was more significant than that in CIH4 group (P<0.05). Compared with CIA group,there was a significant rise in the protein expressions of PTEN in CIH4 and CIH8 groups (P<0.05). Compared with CIH4 group,the rise of the protein expressions of PTEN in CIH8 group was still statistically significant (P<0.05). Compared with CIA group,there was a significant decline in the protein expressions of p-AKT in CIH4 and CIH8 groups (P<0.05). Compared with CIH4 group,the decline of protein expression of p-AKT in CIH8 group was still of statistical significance (P<0.05). There was a significantly increasing trend for the expression of PTEN in the liver cells of rats with intermittent hypoxia along with the decline of ISI and rise of HOMA-IR. The expression increased significantly with the longer duration of intermittent hypoxia. The expression of p-AKT in liver cells of rats with intermittent hypoxia decreased along with the decline of ISI and rise of HOMA-IR. Furthermore,the decline tendency was more significant with the long duration of intermittent hypoxia. ConclusionThe fasting blood glucose of rats and insulin level increase due to the chronic intermittent hypoxia,resulting in the insulin resistance. The degree of insulin resistance increases with the longer duration of intermittent hypoxia. The expression of PTEN protein increases with intermittent hypoxia,and that of p-AKT protein decreases,which is obviously correlated with ISI and HOMA-IR. It is indicated that the PTEN protein possibly play an important role in the mechanism of insulin resistance for rats with intermittent hypoxia.
Objective To investigate the inhibition effect of silence of a disintegrin and metalloproteinase 17 (ADAM17) gene on proliferation and apoptosis of HT29 colon cancer cells and its possible mechanism. Methods HT29cells were divided into 3 groups: cells of interference group were transfected with recombinant lentivirus vector, cells of negative control group were transfected with negative recombinant lentivirus vector, and cells of blank control group were treated with PBS. The expression of ADAM17 mRNA was detected by real-time PCR, the expressions of ADAM17 protein, caspase3, protein kinase B (Akt), glycogen synthase kinase-3β (GSK3β), phospho-protein kinase B (P-Akt), phospho-glycogen synthase kinase-3β (P-GSK3β) protein were detected by Western blot method, the cell proliferation was detected by MTT assay, and the apoptosis rate was detected by Annexin V-FITC/PI cell death detection kit. Results Compared with the control group and the negative control group, the interference group was related to low expressions of ADAM17 mRNA and its protein, low optical density value at the same time point (24, 48, and 72 h), high apoptosis rate, high expression level of caspase3 protein, but low expression levels of P-Akt and P-GSK3β protein (P<0.05). Conclusion Silent ADAM17 gene could significantly induces apoptosis and inhibits the proliferation of HT29 cells, which maybe via inhibiting Akt/GSK3β signaling pathway.
ObjectiveThis study aims to study the effects and mechanism of resveratrol on hepatocellular carcinoma (HCC) cells through phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) axis.MethodsHepG2 cells at logarithmic growth stage were treated with different concentrations (0, 12.5, 25.0, and 50.0 μmol/L) of resveratrol, respectively. Then the proliferation of HepG2 cells was detected by the CCK8 method and real time cell anaIysis (RTCA) system, the expressions of signal molecules associated with PI3K/Akt axis was detected by the Western blot method, including PI3K p58, phosphorylation protein kinase B (p-Akt), total protein kinase B (t-Akt), and CyclinA2 protein.ResultsResveratrol had a significant inhibitory effect on the growth of HepG2 cells in a time and dosage dependent manner. After 48 h treatment of resveratrol to HepG2 cells, 50.0 μmol/L resveratrol inhibited the growth of HepG2 cells most significantly. Further, the RTCA system studies also found that resveratrol had a time and concentration dependent effect on the reduction of normalized cell index (NCI) in HepG2 cells. Flow cytometry results showed that, apoptosis rates of 12.5, 25.0, and 50.0 μmol/L group were higher than that of 0 μmol/L group. Compard with 0 μmol/L group, the expressions of PI3K p85, p-Akt, and CyclinA2 protein in HepG2 cells of 12.5, 25.0, and 50.0 μmol/L resveratrol group was significantly higher (P<0.05), although there was no significant effect of resveratrol on the expression of t-Akt in HepG2 cells (P>0.05).ConclusionsResveratrol might have anti-proliferation effects on HepG2 cells through PI3K p85/Akt signaling axis. This study could provide a novel idea for the treatment to HCC.
Objective To investigate the effect of microRNA-27a (miR-27a) on the apoptosis of human lung adenocarcinoma cells A549 induced by lipopolysaccharide (LPS) by regulating the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) pathway, and its mechanism is discussed preliminarily. Methods The complementary binding sites of miR-27a and phosphatidylinositol-3 kinase catalytic subunit delta (PIK3CD) were analyzed by Starbase and verified by double luciferase. The A549 cells were divided into normal group, LPS group, LPS+miR-27a mimic negative control group, LPS+miR-27a mimic group, LPS+miR-27a mimic+PI3K activator group. In the LPS+miR-27a mimic negative control group, LPS+miR-27a mimic group and LPS+miR-27a mimic+PI3K activator group, the cells were transfected with miR-27a mimic negative control, miR-27a mimic and miR-27a mimic, respectively, and were cultured for 6 h. After that, the cells were cultured in complete medium for 24 h, and then, except for the normal group, the cells in the other groups were stimulated with 10 mg/L LPS for 24 h, and the PI3K activator 740 Y-P was added to the LPS+miR-27a mimic+PI3K activator group, and cells in normal group were cultured in complete medium for the same time. Real-time quantitative polymerase chain reaction was used to detect the expression level of miR-27a in cells; cell counting kit 8 was used to detect cell proliferation; Hoechst33342 staining and flow cytometry was used to detect apoptosis; autophagy of A549 cells was observed by transmission electron microscope; Western blot was used to detect the expression of PIK3CD, phosphorylated-AKT (p-AKT), B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), cleaved caspase-3 and microtubule-associated protein 1 light chain 3 II (LC3II) protein. Results There was a binding site between miR-27a and PIK3CD, which was verified by double luciferase. Compared with those in normal group, the expression level of miR-27a, proliferation rate and protein expression level of Bcl-2 in LPS group and LPS+miR-27a mimic negative control group were lower (P<0.05), the apoptosis rate, protein expression levels of PIK3CD, p-AKT, Bax, cleaved caspase-3, LC3Ⅱ were higher (P<0.05); compared with those in LPS group and LPS+miR-27a mimic negative control group, the expression level of miR-27a, proliferation rate and protein expression level of Bcl-2 in LPS+miR-27a mimic group were higher (P<0.05), the apoptosis rate, protein expression levels of PIK3CD, p-AKT, Bax, cleaved caspase-3, LC3Ⅱ were lower (P<0.05); compared with those in LPS+miR-27a mimic group, the expression level of miR-27a and proliferation rate in LPS+miR-27a mimic+PI3K activator group were lower (P<0.05), the apoptosis rate, protein expression levels of PIK3CD, p-AKT, cleaved caspase-3, LC3Ⅱ were higher (P<0.05). The number of cells in the normal group was more, the cells were closely arranged, the nucleus size was uniform, and the organelle structure was normal; in LPS group and LPS+miR-27a mimic negative control group, cells became round, nuclei pyknosis, formed clumps, and showed multiple round autophagic vesicles of different sizes; the number of nuclear pyknotic cells in LPS+miR-27a mimic group decreased, and the number of nuclear pyknotic cells in LPS+miR-27a mimic+PI3K activator group increased compared with LPS+miR-27a mimic group, a small number of circular autophagic vesicles were observed, but the number was different. Conclusion Overexpression of miR-27a can inhibit PI3K/Akt pathway and reduce LPS induced apoptosis of human lung adenocarcinoma cells A549, which may be related to the reduction of autophagy.
ObjectiveTo understand the research status of phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signaling pathway in the thyroid cancer (TC), as well as its role in the occurrence, cell differentiation, invasion, and metastasis of the TC, so as to find potential targets for treatment of TC. MethodThe literature about the research of PI3K/AKT signaling pathway in the TC was searched and summarized. ResultsThe PI3K/AKT signaling pathway was abnormally activated directly or indirectly in the TC, resulting in inhibition of cell apoptosis, malignant proliferation, accelerated cycle progression, invasion, and metastasis, etc., which promoted the occurrence and development of the TC. There were also some tumor suppressor genes, microRNAs, long chain non-coding RNAs, etc., which indirectly inhibited the activation of PI3K/AKT signaling pathway, or directly acted on it inhibiting its activity to inhibit the occurrence and development of the TC. ConclusionsFor the TC, some proteins, genes, microRNAs, and long chain non-coding RNAs directly or indirectly activate the PI3K/AKT signaling pathway through different targets to promote the occurrence and development of TC. At the same time, many targets inhibit the activation of the PI3K/AKT signaling pathway, which inhibits the malignant proliferation, invasion, and metastasis of TC. At present, there have been studies trying to use PI3K/AKT signaling pathway as a breakthrough for the treatment of TC. In-depth exploration of the role of PI3K/AKT signaling pathway in different TC is of great significance to find new targets for the treatment of TC.
ObjectiveTo investigate the in vitro effect of pseudolaric acid B (PAB) on apoptosis of protoscolece cells and its regulatory effects on angiogenesis and cell apoptosis in the the lesion-host microenvironment tissue in vivo, as well as its possible mechanisms, in order to provide a basis for the clinical development of new alternative drugs for Echinococcus multilocularis. MethodsIn vitro experiments: the protoscoleces, vesicles, germinal cells, human foreskin fibroblasts (HFFs) and normal human liver cells were treated with different concentrations of PAB (0, 2.5, 5, 10, 20, 40, 80, 160 and 320 μmol/L) for 7, 5, 5, 5 and 5 days, then evaluated the survival rate of the protoscoleces, the release level of phosphoglucose isomerase (PGI) from the vesicles, the viability of the germinal cells, as well as the viability of HFFs and normal human liver cells. The protoscoleces and vesicles were fixed with 2.5% glutaraldehyde and used for scanning electron microscopy and transmission electron microscopy observation. Animal experiments: the protoscoleces were isolated from the abdominal lesions of the protected gerbils, and then infected 18 C57BL/6J mice by intraperitoneal injection to establish models, dividing into 3 groups with 6 mice in each group. The model group was given 0.3 mL of PBS by gavage daily, the albendazole (ABZ) group was given 0.3 mL ABZ (100 mg/kg) daily by gavage, the PAB group was given 0.3 mL of PAB (40 mg/kg) by gavage daily. After continuous gavage for 6 weeks, the lesion host microenvironment tissue was taken and ELISA was used to detect the expression levels of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and cysteinyl aspartate specific proteinase3 (caspase3), the expression levels of nitric oxide (NO) was detected using a biochemical detection kit, Western blot was used to detect the expression levels of BCL2-associated X protein (Bax), B-cell lymphoma-2 (Bcl2), caspase3, cleaved-caspase3, VEGF, vascular endothelial growth factor receptor 2 (VEGFR2), phosphatidylinositol 3 kinase (PI3K), phosphorylated PI3K (p-PI3K), protein kinase B (AKT) and phosphorylated AKI (p-AKT) protein. ResultsIn vitro experiments: the protoscoleces of Echinococcus multilocularis were cultured with different concentrations of PAB for 7 days in vitro, the protoscoleces of 40, 80, 160 and 320 μmol/L group all died after 6, 4, 2 and 1 day, respectively; PAB exhibited a certain time and concentration dependence on the protoscoleces of Echinococcus multilocularis. After PAB treatment, the release of PGI in culture supernatant of Echinococcus multilocularis gradually increased with the increase of PAB concentration [concentration for 50% of maximal effect value was (24.40±1.42) μmol/L], the vitality of germinal cells was significantly inhibited [half maximal inhibitory concentration value was (15.94±2.55) μmol/L]. PAB had no significant toxicity to mammalian cells. When 20 μmol/L PAB intervention in the protoscoleces for 3 days, the expression levels of Bax and caspase3 proteins were upregulated, while the expression level of Bcl2 protein was downregulated. Animal experiments: compared with the model group, the wet weight of lesions in the PAB and ABZ groups decreased (P<0.01), and the inhibition rates of lesion growth in the PAB and ABZ groups were 91.03% and 74.44%, respectively. The expression of proliferation and angiogenesis indicators (Ki67, CD34, VEGF, VEGFR2, eNOS, NO) were downregulated in the lesion host microenvironment tissues of mice in the ABZ and PAB groups (P<0.05), while the expression of apoptosis related proteins (caspase3, cleaved-caspase3 and Bax) were upregulated and the expression of PI3K/AKT signaling pathway related proteins (p-PI3K and p-AKT) were downregulated (P<0.05). ConclusionPAB has a strong in vitro and in vivo effect against Echinococcus multilocularis, and its mechanism may be related to the inhibition of PI3K/AKT signaling pathway, leading to increased apoptosis and decreased angiogenesis.