1.Effect of erythropoietin on Caspase-3 expression in light-injured retinal pigment epithelial cells
Chinese Journal of Tissue Engineering Research 2008;12(2):373-376
BACKGROUND: Recent studies demonstrate that erythropoietin (EPO) can protect retina from light injury, and is the mechanism related to the expression of Caspase-3 in the light-injured retinal pigment epithelium (RPE) cells. OBJECTIVE: To study the effects of EPO at different dosages on the expression of Caspase-3 in light-injured human RPE cells. DESIGN: Control observation.SETTING: Qingdao University Medical College. MATERIALS: Adult ARPE-19 cells (American Cell Culture Collection Company); DMEM/F12 mixed medium, fetal bovine serum and trypase (GIBCO Biotechnique Company); recombinant human EPO (rhEPO, Sigma Biotechnique Company); human Caspase-3 quantitative kit (Shanghai Xitang Biotechnique Co.,Ltd); Caspase-3 monoclonal antibody (American Santa Cruz Company); PV6001 immunohistochemistry kit and DAB color reagent kit (Zhongshan Biotechnology Company, Beijing).METHODS: The experiment was carried out in the Department of Pathophysiology at Qingdao University Medical College between May 2006 and January 2007. Human RPE-19 cell strain at passages 2-5 were harvested for light injury models, and the passage cells were divided into 7 groups randomly, with 4 apertures in each group:①normal control group: no light or EPO intervention;②light-injured model group: 12-hour illumination, no EPO intervention;③light-injury and EPO groups: 12-hour illumination with 10 000, 20 000 and 40 000 U/L EPO;④light-injury and 40 000 U/L EPO and AG490 group: 12-hour illumination with 40 000 U/L EPO and inhibitor of Jak2 enzyme 50 000 U/L;⑤light-injury and 40 000 U/L EPO and carbxyl-terminal modulator protein (CTMP) group: 12-hour illumination with 40 000 U/L EPO and specific inhibitor of protein kinase B enzyme 100 μmol/L.MAIN OUTCOME MEASURES: The enzyme linked immunosorbant assay (ELISA) and immunohistochemistry were used to assess the effects of rhEPO at the different doses on the expression of Caspase-3 in light-injured human RPE cells. RESULTS: Caspases-3 was not expressed in RPE cells of the normal control group and was positively expressed in the nucleus of RPE cells of the light-injured model group, showing a specific brown-yellow staining. Expression of Caspase-3 was gradually decreased in every rhEPO group with increase of EPO concentration, with the weakest expression in 40 000 U/L rhEPO group. The effects of EPO on Caspase-3 expression were strongly inhibited in light-injury+ 40 000 U/L EPO +AG490 group and the expression was positive in light-injury +40 000 U/L EPO+CTMP group, which was slightly weaker than light-injured model group. CONCLUSION: The rhEPO can reduce the expression of Caspase-3 in the light-injured human RPE cells, and one of the possible mechanisms is the inhibition of light-injured RPE cell apoptosis by the rhEPO.
2.The expression of hypoxia inducible factor 1α in embryonic and postnatal rats' retinae
Xuxia MENG ; Yingjun NIU ; Ying YANG
Chinese Journal of Ocular Fundus Diseases 2009;25(1):43-46
ObjectiveTo investigate the expression of hypoxia inducible factor 1 (HIF-1α) in rats' retinae during the embryonic and earlier postnatal period.MethodsThe retinal expression patterns of HIF-1α protein and mRNA of embryonic day 12 (E12), E16, E20, and postnatal day 1(P1) and P5 rats were determined by immunohistochemical staining and reverse transcription polymerase chain reaction (RT-PCR).ResultsHIF-1α protein was detected in the neural epithelial layer and the pigment epithelial layer at all those 5 timepoints, with higher expression in the ganglion cell layer and the inner plexiform layer, and seems limited to the ganglion cell layer when retina became more mature. Embryonic rat retina had higher expression of HIF-1α protein and mRNA than postnatal retina, the difference was significant (P<0. 01). ConclusionThe expression of HIF-1α in rats' retinae differs from embryonic to earlier postnatal stages.
4.Identification of novel inhibitors of the streptogramin group A acetyltransferase via virtual screening
Guangfeng WANG ; Niu HUANG ; Zhihong MENG ; Quanhai LIU
Acta Pharmaceutica Sinica 2007;42(1):47-53
Virginiamycin acetyltransferase D (VatD) plays a vital rule in streptogramins resistance by chemically inactivating streptogramin A. Therefore, it is desirable to discover novel small molecular weight inhibitors of VatD via state-of-the-art virtual screening techniques. This "cocktail" strategy by combining VatD inhibitor with streptogramins may provide new therapeutic opportunity for resistant bacteria infections. Structure-based virtual screening method (molecular docking) was applied to rank and score a chemical database containing 300 000 commercially available compounds against the VatD substrate binding site. Twenty six out of the 200 top scored compounds from the docking calculation were selected and submitted to the VatD enzymatic inhibition assay. The plasmid pRSET B/vatD was constructed and transformed into E.coli (trxB) host cells for over-expression, and VatD enzyme was purified and validated by showing acetyltransferase activity to Virginiamycin M1. Three out of these 26 tested compounds showed enzymatic inhibition on VatD with IC50 168.6, 91.0 and 55.2 μmol·L-1, separately. Other compounds could not be dissolved in the system and/or had little effect on the enzyme (IC50>200 μmol·L-1). To our knowledge, it is first time that small molecular weight organic compounds were identified as VatD inhibitors. It is expected that the VatD inhibitors identified at present study could serve as lead compounds for the further development of the novel therapeutic agents to overcome streptogramins resistance.
5.Intervention of basic fibroblast growth factor on apoptosis of retinal nerve cells and expression of regulatory genes in rats after retinal ischemic reperfusion
Ying ZHAO ; Yingjun NIU ; Zhanyu ZHOU ; Chunyan YUAN ; Yan MENG
Chinese Journal of Tissue Engineering Research 2006;10(13):181-183
BACKGROUND: Basic fibroblast growth factor (bFGF), a kind of polypeptide growth factor possessing multifunctional biological activities,can protect neurons and promote the growth of nerves. It has been corfirmed that bFGF has therapeutic effects on retina ischemia/reperfusion injury (RIRI).OBJECTIVE: To establish RIRI model and analyze the effects of bFGF on cellular apoptosis of retina and the expression of regulatory gene protein.DESIGN: Randomized grouping and validating trial.SETTING: Department of Ophthalmology, the Affiliated Hospital of Medical College of Qingdao University.MATERIALS: The experiment was conducted at the Research Laboratory of Pathology, Department of Ophthalmology, Medical College of Qingdao University, from April 2002 to December 2003. Twenty-eight healthy Wistar rats were enrolled in this experiment. Four rats were randomly chosen for normal control group, the left eyes of the other 24 rats were set as normal saline control group, and the right eyes were set as bFGF group.METHODS: Normal saline control group and bFGF group adopted the rat RIRI models established by transiently elevating intraocular pressure. Normal saline of 12 μL was injected into the vitreous cavity of the left eyes of the rats in normal control group. 12 μL bFGF was injected into the vitreous cavity of the right eyes of the rats in bFGF group, 4 rats once. No administration was given in normal control group. The expression of apoptotic cells was detected and apoptosis indexes were calculated with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method and immunohistochemical staining method at the 1st, 6th,12th, 24th,48th and 72nd hours after reperfusion and ischemia for 1 hour.MAIN OUTCOME MEASURES: ① The detection results of apoptotic cells in situ of retina tissuesat different time points after reperfusion. ②The expression of Fas and caspases-2 in retina tissues at different time points after reperfusion.RESULTS ① Comparison of apoptosis indexes of retina tissues at different time points after ischemia reperfusion: There were no apoptotic cells in the retina tissues of the rats in normal control group. As compared with those in normal saline control group, apoptosis indexes in bFGF group were significantly decreased at ischemia 1 hour and reperfusion 1, 6, 12, 24, 48and 72 hours, especially at the 12th, 24th and 48th hours after reperfusion (t =5.362-5.595, P < 0.05). ② The change of Fas expression at different time points after ischemia reperfusion: There was hardly any Fas expression in normal control group. As compared with that in normal saline control group, Fas expression in bFGF group was significantlydecreased at ischemia 1 hour and reperfusion 1, 6, 12, 24, 48 and 72 hours, especially at the 6th, 12th and 24th hours after reperfusion (t=3.954-9.327, P < 0.05). ③The changes of caspase-2 expression at different time points after ischemia reperfusion: There was no caspase-2 expression in normal control group.Compared with that in normal saline control group, the number of caspase2 positive cells in bFGF group was significantly decreased at the 6th,12th,24th, 48th and 72nd hours after ischemia for 1 hour and reperfusion (t=4.125-15.641, P < 0.05).CONCLUSION: bFGF can significantly inhibit the expression of apoptosis gene Fas and caspase-2 in the ischemia and reperfusion of retina, thus reducing cellular apoptosis of ganglion cells and exerting therapeutic effects on the ischemia and reperfusion of retina.
6.Research on anti T47 D breast cancer activity and its G protein-coupled estrogen receptor pathway of tanshinone IIA
Piwen ZHAO ; Jinfeng ZANG ; Shiying TAO ; Meng CHEN ; Jianzhao NIU
Chinese Pharmacological Bulletin 2015;(10):1458-1462
Aim To explore the effects of tanshinone IIA on cell proliferation via G protein-coupled estrogen receptor inductive and regulative pathway in typical es-trogen receptor and G protein-coupled estrogen receptor positive T47D breast cancer cells. Methods The pro-liferation rate of T47 D cells influenced by tanshinone IIA was analyzed by MTT assay. G protein-coupled es-trogen receptor agonist G1 and GPER antagonist G15 were employed as tools. GPER SiRNA was applied to build GPER gene silence T47D cells. GPER expres-sion influenced by tanshinone IIA was measured by Western blot. Results The proliferation rates of T47D cells treated with 1 × 10 -5 mol·L-1 - 1 × 10 -7 mol· L-1 of tanshinone IIA were decreased significantly. Such effects could be attenuated by G1 or enhanced by G15 . Growth of GPER SiRNA transfected T47 D cells were significantly inhibited by 1 × 10 -5 mol·L-1 - 1 × 10 -7 mol·L-1 of tanshinone IIA treating. Result of Western blot showed that tanshinone IIA at 1 × 10 -5 mol· L-1 and 1 × 10 -6 mol · L-1 could induce de-crease of GPER protein expression in T47D cells. Conclusions Tanshinone IIA shows inhibitory effects on proliferation rate of T47 D breast cancer cells via GPER pathway. Tanshinone IIA could perform regula-tive function on GPER expression level in target cells.
7.Alteration of hypoxia inducible factor-1 alpha in retina during rat development
Xuxia MENG ; Yingjun NIU ; Ying YANG ; Wenhua XU
Chinese Journal of Tissue Engineering Research 2008;12(42):8388-8392
BACKGROUND: Hypoxia inducible factor-1 α(HIF-1 α) is not only related to physiological reaction of hypoxia,but also takes part in normal embryonic development.OBJECTIVE: To study the alteration of HIF- 1 α in retina during rat development.DESIGN,TIME AND SETTING: Randomized contrast animal study,which was performed in the Shandong Provincial Molecular Virus Key Laboratory,Medical College of Qingdao University between January and September 2007.MATERIALS: Adult Wistar rats,nulliparity,clean grade,and weighing 200 250 g were used in this study.METHODS: Male and female rats were caged as the ratio of 1 : 1.Embryos were obtained at 12-day,16-day,and 20-day pregnancy.Eyeballs were obtained from newborn rats by anesthesia at 1-day,5-day,10-day,and 12-month birth.Retina was separated and made into paraffin section.MAIN OUTCOME MEASURES: Expressions of HIF 1 α protein and HIF-1 α mRNA in retina were measured by immunohistochemistry and semiquantitative reverse transcription-polymerase chain reaction at various dine points of embryonic development.RESULTS: HIF-1 α positively expressed at stratum neuroepitheliale retinae and purpurogenous membrane in the embryonic phase.Additionally,HIF-1 α still positively expressed at stratum neuroepitheliale retinae and purpurogenous membrane,especially in ganglionic cells and inner plexiform layer,in early development.With the gradual development,the positive expression was mainly located at stratum ganglionare retinae.HIF-1 α protein and mRNA expressions were the highest in the embryonic phase,lower in the development,and the lowest in the adult period.There were significantly differences among these three phases (P < 0.01).CONCLUSION: HIF-1 α decreases gradually in retina and its expression is mainly located at stratum ganglionare retinae.
8.Changes of erythropoietin expression during the embryonic deveiopment period of rat retina
Chun-yan, YUAN ; Xu-xia, MENG ; Ying-jun, NIU
Chinese Journal of Experimental Ophthalmology 2011;29(11):998-1001
Background Erythropoietin (EPO) was proved to be express in hematopoietic tissue and nervous system and play the effects of stimulating blood cell production and protecting nervous tissue.Researches showed that EPO is expressed in the embryon brain of animal.However,whether EPO exist in nervous-derived retina and its action on retina with the development is concerned. Objective This research was to investigate the expression of EPO during the embryonic development period of rat retina and explore the role of EPO in retina development process.Methods Clean Wistar rats with pregnancy for 12 days,16 days and 20 days were collected,and the embryonic 12-day rats (E12 d,5 rats),embryonic 16-day rats (E16 d,5 rats) and embryonic 20-day rats ( E20 d,5 rats) were obtained by caesarean operation,and 5 12-month W istar rats were used as controls.The rats were sacrificed by cervical dislocation and the retinal sections were prepared in the different-embryo-phase (12 d,16 d,20d) and growth phase.The expression of EPO protein and mRNA in rat retina was detected by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR),respectively.The feed and use of the animals followed the Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results EPO was positively expressed in the cytoplasm and nuclei in the neuroepithelial layer and pigment epithelium of every-embryo-phase rats but only in retinal ganglion cell layer in 12-month-old rats.The gray scale values of EPO expression in retina were 105.55±10.35,99.35± 8.71,83.27± 7.84and 30.30± 3.80 in E12 d rats,E16 d rats,E20 d rats and 12-month-old rats respectively with a statistically significant difference (F=76.13,P<0.01 ).RT-PCR revealed that the relative values of EPO mRNA expression in retina were 0.876±0.10,0.861 ±0.09 and 0.256±0.03 in E16 d rats,E20 d rats and 12-month-old rats respectively,presenting a elevated value in embryonic rats compared with adult rats ( P =0.00).Gel imaging deletion showed that the A value of EPO amplification products was highest in E16 d rats and lowest in adult rats.Conclusions The expression of EPO appears a high to low fashion during the embryonic development of Wistar rats,which is closely associated with the developing procedure of retina.
9.Expression changes of transforming growth factor-β1 and fibronectin in bovine trabecular meshwork cells cultured by iris pigment particles
Chunhuan, NIU ; Qiang, WANG ; Jie, MENG ; Yuzhen, LIU
Chinese Journal of Experimental Ophthalmology 2017;35(4):320-324
Background Pigmentary glaucoma and pseudoexfoliation glaucoma are characterized by pigment dispersion in trabecular meshwork,and the dipersitional pigment probably contributes to the resistance of aqueous outflow pathway,irreversible damage of the trabecular meshwork and the remodeling abnormality of extracellular matrix.Researches determined that contents of transforming growth factor-β (TGF-β) in the aqueous humor are increased in glaucomatous eyes.However,the effects of TGF-β and fibronectin (FN) in the trabecular meshwork cells (TMCs) acted by iris pigmentary particles still are not elucidated.Objective This study was to investigate the effects of iris pigment particles on TGF-β1 and FN expression in bovine TMCs (BTMCs) cultured in vitro.Methods BTMCs were cultured in vitro by explant culture method and identified by morphological evaluation.The third generation of BTMCs were divided into normal control group and pigment group,and 100 μ1 PBS and 100 μl iris pigment suspension (final concentration of 1 × 107 particles/ml) were added into the medium for 24 hours,respectively.The expressions of TGF-β1 mRNA,FN mRNA and their proteins in the BTMCs were assayed by real-time fluorescence quantitative PCR and ELISA,respectively.Results Cultured cells grew well and showed the fusiform,polygon and dendritic like in shape,with pigmented and round nuclei.The relative expression levels of TGF-β1 mRNA and FN mRNA in the cells were 2.98±0.27 and 0.36±0.10 in the iris pigment group,which were significantly higher than 1.00±0.00 and 1.00±0.00 in the normal control group (t =12.68,10.60,both at P =0.00).The concentrations of TGF-β1 protein and FN protein in the cell suspension were (156.60±9.74)ng/L and (59.29±15.79)mg/ml in the iris pigment group,showing significant differences in comparison with (65.46 ± 14.24) ng/L and (102.10 ± 12.14)mg/mlin the normal control group (t=9.15,P=0.00;t=3.72,P=0.02).Conclusions The expression of TGF-β1 is up-regulated and that of FN is down-regulated in BTMCs cultured by iris pigment,inferring that TGF-β1 and FN participate in the pathogenesis and development of pigmentary and pseudoexfoliation glaucoma.
10.The level and clinical significance of serum anti-lysosomal associated membrane protein-2 antibody in patients with anti-neutrophil cytoplasmic antibodies-associated vasculitis
Meng NIU ; Na LI ; Jianping SUN ; Jiaowen HUANG ; Jia ZHAO
Chinese Journal of Rheumatology 2016;20(5):321-324
Objective To explore the clinical.significance of serum anti-lysosomal associated membrane protein-2 (LAMP-2) antibody in the pathogenesis of anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AASV) by investigating the relationship of its levels and AASV.Methods Sera from twenty patients with AASV and twenty healthy controls were collected.Serum anti-LAMP-2 antibody was detected using commercial enzyme linked immunosorbent assay (ELISA) kits.Anti-LAMP-2 antibody levels between the two groups were assessed using the t test,the correlation between anti-LAMP-2 antibody levels and erythrocyte sedimentation rate (ESR),C-reactive protein (CRP) was assessed by Spearman's rank correlation test,the correlation between anti-LAMP-2 antibody levels and the Birmingham vasculitis activity score(BVAS),hemoglobin (Hb),albumin (Alb) was assessed by Pearson's rank correlation test.Results ① The serum level of anti-LAMP-2 antibody in patients with AASV [(3714±1446) pg/ml] was higher than that in the healthy controls [(174±43) pg/ml] (t=10.94,P<0.05).The serum level of Hb [(99±30) g/L] and Alb [(27±5) g/L]in patients with AASV was lower than that in healthy controls [(138±14) g/L,(44±3) g/L] (t=5.27,t=13.04,P>0.05).② The level of anti-LAMP-2 antibody in AASV was positively correlated with BVAS (r=0.669 9,P<0.05),and was not found elevated compared with ESR,CRP,Hb and Alb (P>0.05).Conclusion ① AntiLAMP-2 antibody is involved in the pathogenesis of AASV.② Anti-LAMP-2 antibody is correlated with the activity of AASV,it may be an indicator of AASV disease activity.