1.Influence of presenilin 1 overexpression on endogenous tau phosphorylation in neuroblastoma cells
Bo CHEN ; Min CHENG ; Yin WANG ; Fengyan SUN ; Cuiqing ZHU
Fudan University Journal of Medical Sciences 2006;33(5):651-656
Purpose To study the effect of overexpressing either wild type or a familial Alzheimer disease mutant presenilin 1 (mPS1) on tau phosphorylation in neuroblastoma NG-108 cells. Methods Three different plasmids transfected NG-108 cells respectively. Immunostaining and confocal microscopic technique were used to study the distribution of presenilin 1 and phosphorylated tau. Immunoblot test was applied to investigate the change of tau phosphorylation. Results Immunostaining showed that in brain of sporadic Alzheimer disease, PS1 mainly distributed in neuron and partially colocalized with the phosphorylated tau. Immunoblot tests showed that the cells transected either wild type PS1 or mPS1 contained more phorphorylated tau than the control cells. However, MTT test showed no significant difference between mock transfected cells and the wPS1 or mPS1 transfected cells. In addition, after transfection of the constructed PS1-EGFP vector, overexpressed EGFP-PS1 was located at cell surface membrane and subcellular organelles at earlier time at 12 hr, then EGFP-PS1 diffused in cytosol. Immunocytochemical observations demonstrated that some of the PS1-EGFP transfected cells contained more phosphorylated tau protein, which formed aggresome with PS-1-EGFP. When treated with phosphotase inhibitor okadaic acid, in the PS1-EGFP transfected cells accumulated more phosphorylated tau than the un-transfected cells. Conclusions Wild type PS1 is possibly involved in tauopathy in sporadic Alzheimer's disease.
2.The effects of SST for predicting the differentiation of endometrial carcinoma and on cell biological behavior
Qian ZHAO ; Jingyi ZHOU ; Yuan CHENG ; Lijun ZHAO ; Jiaqi WANG ; Fengyan XIA ; Jianliu WANG
Tianjin Medical Journal 2017;45(7):685-690
Objective To investigate the expression levels of somatostatin (SST) gene in endometrial adenocarcinoma tissues and cell lines,and the effects of over-expression of SST gene on the proliferation and invasion of endometrial cancer cell line Ishikawa in vitro.Methods Tissue sections of normal endometrium,endometrioid adenocarcinoma and uterine papillary serous carcinoma were selected to detect the expressions of SST by immunohistochemical method.The total RNA was extracted from fresh specimens that were confirmed as endometrioid adenocarcinoma.According to FIGO staging,samples included G1 (7 cases),G2 (6 cases) and G3 (5 cases) of endometrioid adenocarcinoma.The SST expression levels were detected by real-time PCR.Three endometrial cancer cell lines,Ishikawa,HEC-1A and KLE,were selected and the expression levels of SST were detected by real-time PCR and Western blot assay.Transfection was performed with pLVX-SST and pLVX.The transfection efficiency was observed by fluorescence confocal microscopy.The protein levels of SST were detected by Western blot assay.The assays of CCK-8 and transwell were applied to examine variations in cell proliferation and invasion.Results Immunohistochemical results showed that SST expression was increased in endometrioid adenocarcinoma and uterine papillary serous carcinoma compared with that of normal endometrium.Real-time PCR showed that SST expression was significantly increased in G3 compared with that of G1 and G2 in endometrioid adenocarcinoma (P < 0.05).No matter mRNA or protein,SST levels were significantly increased in endometrial cancer cell line KLE compared with those of Ishikawa and HEC-1A,and the expression levels of SST mRNA and protein were significantly increased in HEC-1A group than those of Ishikawa group (P<0.05).The expression of SST protein was significantly higher in the group of Ish-SST after 2 generations compared with that of Ish-ctr group.There were no significant differences in cell proliferation and invasive ability after over-expression of SST between Ishikawa cell group and control group (P > 0.05).Conclusion SST is highly expressed in poorly differentiated endometrial cancer cells.The proliferation and invasion are not increased after the over-expression of SST in Ishikawa cell line of endometrial cancer.
3.Inhibitory effect of siRNA-KCNQ1OT1 on human lens epithelial cell apoptosis by targeting miR-199a-5p
Cheng LU ; Fengyan ZHANG ; Yuhang ZHANG ; Jiajuan ZHANG
Chinese Journal of Experimental Ophthalmology 2022;40(6):514-523
Objective:To explore the inhibitory effect of long non-coding RNA (lncRNA) KCNQ1 overlapping transcript 1 (KCNQ1OT1) by targeting microRNA-199a-5p (miR-199a-5p) on the apoptosis of human lens epithelial cells (LECs).Methods:The anterior lens capsule tissue of 23 age-related cataract patients who underwent cataract surgery in Xinxiang First People's Hospital from December 2018 to August 2019 was collected.At the same time, anterior lens capsules from 20 healthy donor were collected.The expressions of KCNQ1OT1 and miR-199a-5p in the tissues were detected by real-time fluorescence PCR.Human LECs SRA01/04 cultured in vitro were divided into blank control group, model control group, small interfering RNA-negative control (siR-NC) group, siR-KCNQ1OT1 group, miR-NC group, miR-199a-5p group, siR-KCNQ1OT1+ anti-miR-NC group and siR-KCNQ1OT1+ anti-miR-199a-5p group.No intervention was administered to blank control group.Cells in model control group were cultured with 100 μmol/L H 2O 2 for 24 hours to establish oxidative stress injured model, and cells in the other six groups were transfected with corresponding transfection reagents for 6 hours by liposome method according to grouping, and then treated with 100 μmol/L H 2O 2 for 24 hours.The expressions of KCNQ1OT1 and miR-199a-5p in lens anterior capsule tissue and LECs cells were determined by real-time fluorescent quantitative PCR.Cell viability was detected with thiazolyl blue (MTT). Cell apoptosis was analyzed by flow cytometry.The expressions of B-cell lymphoma/leukemia-2 (bcl-2) and bcl-2 related X protein (Bax) proteins were assayed by Western blot.The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured by enzyme-linked immunosorbent assay (ELISA). The targeting relationship between KCNQ1OT1 and miR-199a-5p was verified by dual luciferase reporter experiment.The study protocol was approved by an Ethics Committee of Xinxiang First People's Hospital (No.2019-001). Written informed consent was obtained from relatives of patient. Results:The relative expression of KCNQ1OT1 in the anterior capsule of patients with age-related cataract was 2.41±0.42, which was significantly higher than 0.97±0.19 of normal people, and the relative expression of miR-199a-5p in the capsule of patients with age-related cataract was 0.36±0.12, which was lower than 1.04±0.15 of normal people, and the differences were statistically significant ( t=14.112, 16.507; both at P<0.001). Compared with blank control group, the relative expressions of KCNQ1OT1 and bax protein, cell apoptosis rate and MDA content were significantly increased, and the relative expressions of miR-199a-5p and bcl-2 protein, cell viability and SOD activity were significantly reduced in model control group, showing statistically significant differences (all at P<0.001). Compared with siR-NC group, the relative expressions of KCNQ1OT1 and bax protein, cell apoptosis rate and MDA content in cells of siR-KCNQ1OT1 group were decreased, while the relative expression of bcl-2 protein, cell survival rate and SOD activity were increased, and the differences were statistically significant (all at P<0.05). Compared with miR-NC group, the KCNQ1OT1-wild type (WT) luciferase activity in miR-199a-5p group was significantly decreased, with a statistically significant difference ( t=21.131, P<0.001). The relative expression levels of miR-199a-5p and bcl-2 proteins, cell survival rate and SOD activity were significantly increased, and the relative expression of bax protein, cell apoptosis rate and MDA content were significantly decreased in miR-199a-5p group than those in miR-NC group, and the differences were statistically significant (all at P<0.05). The relative expression levels of miR-199a-5p and bcl-2 proteins, cell survival rate and SOD activity were significantly lower, and the cell apoptosis rate, relative expression of bax protein and MDA content were significantly higher in siR-KCNQ1OT1+ anti-miR-199a-5p group than those in siR-KCNQ1OT1+ anti-miR-NC group, and the differences were statistically significant (all at P<0.05). Conclusions:The inhibition of KCNQ1OT1 can promote the cell viability of human LECs, inhibit H 2O 2-induced cell apoptosis and oxidative stress, and the mechanism may be related to the up-regulation of miR-199a-5p.
4.Mechanism of oxidative stress injury in the hippocampus of glutaryl CoA dehydrogenase -/- rats
Fengyan TIAN ; Yanyun LI ; Cheng ZHEN ; Chaohui GU
Chinese Journal of Neuromedicine 2021;20(1):49-55
Objective:To investigate the mechanism of oxidative stress injury and possible pathways in glutaryl CoA dehydrogenase deficient (GCDH -/-) rats with high lysine diet (Lys). Methods:Four-week-old rats were randomly divided into 6 groups: wild type+standard diet group (WT, n=6), GCDH -/-+standard diet group (GCDH -/-, n=11), WT+Lys group ( n=8), GCDH -/-+Lys group ( n=13), WT+Lys+vitamin (V) E group ( n=7), and GCDH -/-+Lys+VE group ( n=12); rats in the WT group and GCDH -/- group were given standard diet, and rats in the WT+Lys group, GCDH -/-+Lys group, WT+Lys+VE group and GCDH -/-+Lys+VE group were given high lysine diet (4.7% Lys); rats in the WT+Lys+VE and GCDH -/-+Lys+VE group were given VE (100 mg/[kg·d]) by intragastric administration once per d, and rats in other groups were given normal saline by intragastric administration once per d. The body mass and survival of rats in each group were observed. Twenty-eight d after intervention, rats were injected intraperitoneally with 10% chloral hydrate and anesthetized; their brains were severed to obtain hippocampal tissues; and pathomorphological changes were observed by HE staining; the content/activity of glutathione peroxidase (GPx), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) in the hippocampus were detected by ELISA; the protein expressions of P38, c-Jun N-terminal kinase (JNK) and extra-celluar regulated protein kinase (ERK) in the hippocampus were detected by Western blotting. Results:(1) The survival ratio of rats in the GCDH -/-+Lys group was 9/13, and that in the GCDH -/-+Lys+VE group was 11/12. From the 7 th d of intervention, the body mass of rats in the GCDH -/-+Lys group and GCDH -/-+Lys+VE group was significantly lower than that in the WT group ( P<0.05). (2) As compared with that in the WT group, MDA content in hippocampal tissues of rats in the GCDH -/-+Lys+VE group and GCDH -/-+Lys+VE group was significantly increased ( P<0.05). As compared with WT group, GCDH -/-+Lys group had significantly decreased GPx activity, CAT activity and SOD activity, and statistically decreased GSH content ( P<0.05). As compared with those in the GCDH -/-+Lys+VE group, the GPx activity, CAT activity, SOD activity, and GSH content in the GCDH -/-+Lys+VE group were significantly increased ( P<0.05). (3) Western blotting showed that as compared with that in the WT group, the P38 protein expression in the hippocampus of rats in GCDH -/-+Lys group and GCDH -/-+Lys+VE group was significantly increased ( P<0.05); as compared with GCDH -/-+Lys+VE group, the P38 protein expression in the GCDH -/-+Lys+VE group was statistically decreased ( P<0.05). Conclusion:There is oxidative stress injury in the hippocampus of GCDH -/- rats with Lys, whose possible mechanism is to activate P38 and initiate MAPK signaling pathway; VE protects GCDH -/- hippocampal cells from oxidative stress by decreasing P38 expression.
5.Comparative analysis of CT features of gastrointestinal stromal tumors,neurogenic tumors and leiomyomas in stomach
Yue LI ; Guihan YANG ; Weichao YANG ; Fengyan CHENG ; Yulin LIN ; Chun YAO ; Xiaofeng CHEN ; Zhiqi YANG
Journal of Practical Radiology 2024;40(8):1296-1299,1333
Objective To investigate the difference of CT features of gastrointestinal stromal tumors(GIST),neurogenic tumors,and leiomyomas in stomach.Methods A retrospective analysis was performed on clinical and CT features from 312 cases of GIST,21 cases of neurogenic tumors,and 35 cases of leiomyomas in stomach.Results GIST were most commonly found in the body of stomach and exhibited large tumor sizes and late onset.CT showed GIST predominantly showed intraluminal and mixed growth pattern with irregular or round shapes and uneven density,and cystic degeneration and calcification were frequently observed.The CT values of GIST in the arterial phase and the degree of arterial enhancement were higher,with light to moderate arterial phase enhancement and moderate to marked venous phase enhancement.Gastric leiomyomas had smaller tumor sizes and presented mainly in the cardia,gastric fundus,and lesser curvature of gastric body.CT showed the intraluminal growth pattern,primarily in round shapes with uniform density,lower incidence of cystic degeneration and calcification,both the arterial and venous phase CT values and the extent of enhancement in these phases were lower,showed no or slight enhancement during the arterial phase and light to moderate enhancement during the venous phase.Gastric neurogenic tumors were predominantly located in the gastric body and antrum.CT showed the tumors demonstrated extraluminal and mixed growth patterns,most with oval-shaped appearace,uniform density and the venous phase CT values and the degree of enhancement were higher,with light to moderate arterial enhancement and moderate to marked venous enhancement.Conclusion GIST,neurogenic tumors,and leiomyomas in stomach can be differentiated based on their distinct CT features.Accurate recognition of these features aids in the differential diagnosis of these kinds of tumors.