1.Inhibitory effect of kringle 4-5 on experimental choroidal neovascularization
Hao WANG ; Wenji WANG ; Houyan SONG
Chinese Journal of Ocular Fundus Diseases 2000;0(04):-
Objective To determine whether kringle 4-5 could inhibit choroidal neovascularization (CNV) in mice induced by argon laser photocoagulation. Methods Fundus laser photocoagulation was performed on C57BL/6J mice to induce CNV. In treatment group, 20 ?g (low dosage group) and 50 ?g (high dosage group) kringle 4-5 were injected retrobulbarly after photocoagulation. In control group, equilibrium liquid was injected retrobulbarly. Choroidal neovascularization was evaluated on the 7th and 14th day after photocoagulation by fundus fluorescein angiography. The mice were killed on the 14th day after photocoagulation, the lesions were evaluated histologically and immunohistochemically, and the expression of CD105 was detected. The Expression of VEGF and bFGF was detected by immunohistochemistry on the 4th day after photocoagulation. Results The incidence of CNV was 64.3% in control group, 51.2%(P
2.Effect of retinal dehydrogenase type 2 inhibitor on embryonic cardiac development of zebrafish
Jia HOU ; Yonghao GUI ; Yuexiang WANG ; Lifeng ZHANG ; Houyan SONG
Chinese Journal of Perinatal Medicine 2010;13(2):117-122
Objective To study the effect of retinal dehydrogenase type 2 inhibitor (4-diethylaminobenzaldehyde,DEAB) on embryonic CSrdiac develclpment of zebrafish model with retinoic acid(RA)deficiency. Methods Zebrafish embryos were treated with DEAB at various concentrations including 1×10~(-6),5×10~(-6),10×10~(-6),25×10~(-6)mol/L at 5,8 and 10.3 hours post fertilization,respectively.The effects of DEAB on the embryonic development were assessed under microscope.1×10~(-9)mol/L exogenous RA was then added to detect the antagonistic effect against DEAB.The abnormal cardiac phenotype,heart rate and ventricular systolic fraction were observed and analyzed between wild type and DEAB treated groups.The expression of specific cardiac gene, natriuretic peptide precursor A,was monitored by whole-mount in situ hybridization to demonstrate the effect of RA signaling on early cardiac development. Results The survival rate of zebrafish embryos declined with the increase of DEAB concentration at different developmental stage.The percentage of abnormal embryos reached 100% when DEAB over 5×10~(-6)mol/L.1×10~(-9) mol/L exogenous RA could eliminate the teratogenic effect of DEAB(≥5×10~(-6)mol/L).DEAB treated embryos presented abnormal cardiac phenotype,including tubular heart,incomplete D-loop,abnormal atrioventricular development,regurgitation,slow blood flow and weak heart beat.The difference of heart rate and ventrieular systolic fraction between wild type and RA deficiency embryos was of statistical significance(P<0.05).The natriuretic peptide precursor A expression remained in the ventricle,but reduced obviously in the atrium with RA signaling deficiency. Conclusions The effects of DEAB on the embryonic development are dose-dependent and time-dependent,and could be rescued by exogenous RA.RA signaling plays a critical role in several key stages of early cardiac development and natriuretie peptide precursor A expression.
3.The Effects of BHC80 Down Regulation on Embryonic Erythropoiesis in Zebrafish
Jiayun HOU ; Qiu JIANG ; Jie ZHANG ; Li TAN ; Houyan SONG
Progress in Biochemistry and Biophysics 2009;36(11):1469-1474
Whole mount in situ hybridization with BHC80 RNA probe showed that BHC80 was expressed in zebrafish central nervous system. Morpholino-modified antisense oligonucleotide was injected into zebrafish zygotes to knock down BHC80 expression. BHC80 knockdown resulted in striking decrease of erythrocytes and accumulation of erythrocytes at PBI. Further investigation of embryonic erythrocytes marker βe3 globin and hematopoiesis transcription factors gata1, c-myb and lmo2 by in situ hybridization showed that the erythroid progenitors marked with gata1 in BHC80 knockdown embryos were high proliferation and their differentiation were delayed, which led to decrease of erythrocytes and accumulation of erythrocytes at PBI. Both in situ hybridization and microangiography indicated that vasculature pattern of BHC80 knockdown embryos were almost normal.
4.The effects of folic acid deficiency on the axial development of zebrafish
Shuna SUN ; Yonghao GUI ; Qiu JIANG ; Linxi QIAN ; Houyan SONG
Fudan University Journal of Medical Sciences 2009;36(6):663-669
Objective To construct a folic acid deficient model in zebrafish and to observe the axial development in folic acid deficient embryos, so as to probe the mechanism by which folic acid deficiency induces abnormal development of axis. Methods We constructed the folic acid deficient zebrafish model by both using the antagonism of dihydrofolate reductase (MTX) and knocking-down dihydrofolate reductase gene. Then we observed the axial excursion of folic acid deficient embryos at 17 hpf under microscope. We labeled and observed the positions of liver, spleen and heart by using whole-mount in situ hybridization with specific antisense RNA probes. The expressions of some genes, which are down stream factors of Nodal signal pathway and important for axial development, were detected by whole-mount in situ hybridization and Real-time PCR. Results Parts of folic acid deficient embryos had axial excursion and abnormal positions of liver, spleen and heart. The expressing intensities of ntl and gsc appeared normal in folic acid deficient embryos, but the expressing spatial patterns were abnormal, which revealed the malformation of axial mesoderm. Conclusions Folic acid deficiency induced the abnormal development of axis and the malformation of axial mesoderm. Folic acid deficiency had no obviouse effect on Nodal pathway.
5.EFFECT OF FOLIC ACID DEFICIENCY ON ZEBRAFISH HEMATOPOIESIS
Shuna SUN ; Yonghao GUI ; Qiu JIANG ; Houyan SONG ; Tao ZHONG
Acta Nutrimenta Sinica 1956;0(01):-
Objective To observe the development of hematopoietic stem cell and the apoptosis of ICM(intermediate cell mass) in folic acid deficient zebrafish embryos and investigate the mechanism by which folic acid deficiency induces abnormal hematopoiesis.Method The folic acid deficient zebrafish model was induced by both using the dihydrofolate reductase antagonism methotrexate(MTX) and knock-down dihydrofolate reductase gene.The development of embryos was observed under microscope.The blood cells were detected by O-dianisidine staining.Whole-mount in situ hybridization and real-time PCR were performed to examine the expression of FLK-1,GATA1and GATA2.Apoptosis in intermediate cell mass(ICM) was examined by TUNEL(terminal-deoxynucleotidyl transferase mediated nick end labeling) method.Results The abnormal developments of ICMs were observed both in MTX treated embryos and DHFR knock-down embryos.O-dianisidine staining revealed that folic acid deficiency resulted in the decreasing number of blood cells.In folic acid deficient embryos,the expression of FLK-1、GATA1and GATA2 was reduced and the apoptosis in ICMs was increased.Conclusion The abnormal hematopoiesis in zebrafish induced by folic acid deficiency is related with the increasing apoptosis in ICMs and decreasing expressions of FLK-1,GATA1and GATA2.
6.Study of microsatellite instability in epithelial ovarian tumors
Yuan LU ; Xishi LIU ; Yuexiang WANG ; Houyan SONG ; Nanbert ZHONG
Journal of Peking University(Health Sciences) 2006;38(1):62-65
Objective: To evaluate the frequency of MSI in epithelial ovarian tumors and its relationship with clinicopathologic features. Methods: Ninety fresh specimens of epithelial ovarian tumors, including 74 primary and 16 secondary tumors, were collected. Microsatellite analysis was carried out using 5 mono- and dinucleotide markers from the National Cancer Institute Consensus Panel by fluorescence-labeled polymerase chain reaction. Results: Of 90 epithelial ovarian tumors analyzed, 18 demonstrated a high level of microsatellite instability (MSI-H), 30 demonstrated a low level of microsatellite instability (MSI-L), and the remaining 42 exhibited microsatellite stability (MSS). Frequency of microsatellite instability (MSI) at loci BAT-25 was higher than that at any other loci. No correlation was found between MSI level and patient age, tumor type, tumor differentiation (P>0.05). But the microsatellite instability-high phenotype correlates with clinical stage.It tended to occur more frequently in early-stage tumors (P=0.03). Conclusion: The frequent MSI in epithelial ovarian tumors suggests that it is an early event to involve in the development of epithelial ovarian tumors.
7.Preparation and characterization of PLGA microspheres containing a staphylokinase variant (K35R)
Jintian HE ; Xianmei TAO ; Wei MO ; Houyan SONG
Acta Pharmaceutica Sinica 2006;41(1):12-18
Aim To produce poly (lactic-co-glycolic acid) (PLGA) microspheres, containing a staphylokinase variant (K35R, DGR) with reduced immunogenecity and antiplatclet aggregation activities,which allowed the preservation of protein stability during both particle processing and drug release.Methods DGR-loaded microspheres were fabricated using a double emulsion-solvent evaporation technique. The effects of preparative parameters, such as stirring rate, polymer concentration, and the excipients of both internal and external aqueous phase (W2 ), on DGR encapsulation efficiency and microsphere characteristics were investigated. In vitro and in vivo release of DGR were conducted and the cause for instability of DGR during release was also investigated. Results Moderate ultrasonic treatment of aqueous DGR/dichloromethane mixtures caused approximately. Eighty four per cent DGR denaturation.However, the activity recovery of DGR almost amounted to 100% when 2% polyvinyl alcohol (PVA) was added into the aqueous phase. It was found that NaCl in the external water phase significantly increased DGR encapsulation efficiency. Furthermore, NaCl in the external water phase played a role in determining size and surface morphology of microsphere. In vitro release test showed a burst release of DGR from microspheres, followed by sustained release of 50% total activity over 15 days. In vivo experiments showed that DGR released from microspheres sustained 5 days. Denaturation of DGR within microspheres might be resulted from acidic microclimate. Conclusion The stability of DGR was effectively protected during microencapsulation and a relatively high encapsulation efficiency of DGR was obtained. PLGA microspheres could be an effective carrier for DGR.
8.Purification and Characterization of Recombinant Angiogenesis Inhibitor r-K4K5
Xiaoqun GUAN ; Yuexiang WANG ; Wei MO ; Liangcheng WU ; Houyan SONG
Fudan University Journal of Medical Sciences 2001;28(1):1-4
Purpose To purify recombinant angiogenesis inhibitor r-K4K5 and investigate its inhibitoryeffects on bovine capillary endothelial (BCE) cell proliferation, chick embryo chorioallantoic membrane(CAM) angiogenesis and growth of experimental human non-small cell lung cancer (adeno). Methodsr-K4K5 was obtained by salting out and gel filtration with the purity of 95% determined by SDS-PAGE.BCE cells were cultured with DMEM media containing r-K4K5. The cells were counted in 24,48,72 hrespectively. r-K4K5 was injected daily into all 7-day chick embryo CAMs and CAM angiogenesis wasobserved at 72 h after incubation. The Balb/c (nu/nu) mice implanted with human SPC-Al tumor pieceswere grown for 10 days and then randomly divided into three groups. One group was treated with PBS, theother two groups were treated with local subcutaneous injection of purified r-K4K5 at 8 μg and 80 μg lpermouse every other day. They were daily observed and sacrificed in 14 days. Each tumor was weighed.Results The number of BCE cells, blood vessels diameter less than 50 μn of chick embryo CAM and theaverage weight of experimental tumor were decreased markedly in all the groups treated with r-K4K5.Conclusions r-K4K5 inhibits proliferation of BCE cells, angiogenesis of chick embryo CAMs and thegrowth of experimental human SPC-A1 non small lung cancer (adeno).
9.The effects of plasmin Kringle domains deficiency mutant on the interface of vitreous and retina in rabbit eyes
Wu, CHEN ; Xin, HUANG ; Wei, MO ; Wenji, WANG ; Houyan, SONG
Chinese Ophthalmic Research 2010;28(3):231-235
Background The vitreoretinal traction plays a critical role in the formation of macular hole and cystoid macular edema.Enzymatic vitreolysis has potential in relieving vitreoretinal traction as a simple and less invasive method in comparison with pars plane vitrectomy.ObjectiveThis study is to investigate the effects of plasmin mutant with kringle domains deficiency(Plm△K)on vitreoretinal interface in new Zealand white rabbits.Methods Plm△K was prepared through activating plasminogen mutant with Kringle domains deficiency (Plg△K) by tissue plasminogen activator (tPA).100μL of Plm△K at the dose of 0.5,1.0 and 1.5μmol/min was injected respectively into the vitreous of 48 New Zealand white rabbits and 16 eyes for each dose.B-scan and optical coherence tomography (OCT) were performed to detect the structure variety at the vitreoretinal interface in 1 day and 7 days after injection.The gross anatomy analysis with triamcinolone acetonide fine particle suspension,as well as histopathological examinations by scanning electron microscopy,was performed in the different time points mentioned above.Results Two peptide chains were determined with the relative molecular weight about 26000 and 5000 by the gel imaging analysis of reduced SDS-PAGE.Separation of the posterior vitreous cortex from retina was found after intravitreous injection under the B-scan and OCT.The ultrastructure change of vitreoretinal interface as well as the examination of fine particle suspension by triamcinolone acetonide demonstrated the same outcome.The degree of remnants of vitreous cortex showed the negative correlation with the dosage of Plm△K (r=-0.9516,P=0.048).No significant correlation was found between the degree of remnants of vitreous cortex and the action time(r=-0.720,P=0.470).There was no obvious morphological difference in outer layer of retina between control eyes and Plm△K-treated eyes.No drug-related adverse event was found after intravitreous injection of Plm△K.Conclusion Intravitreous injection of Plm△K alone can induce complete separation of vitreous from retina.This procedure is safe and effective.
10.Differentiation of mouse embryonic stem cells into endothelial cells through Flk1-expressing mesoderm progenitor cells
Zhe GENG ; Houyan SONG ; Ping LI ; Li TAN
International Journal of Biomedical Engineering 2015;38(2):99-103,后插6
Objective To master the technique of mouse embryonic stem (ES) cells differentiate into endothelial cells,which would be a new therapeutic approach for cardiovascular disease.Methods Expression of selfrenewal marker genes in E 14 cells was assessed.Expression of vascular endothelial growth factor receptor 2 (Flk 1) in monolayer differentiation on day 4 and vascular endothelial cadherin (VE-cadherin) on day 8 were detected.On day 8,differentiation cells were also observed under phase contrast microscopy (PCM) and transmission electron microscope (TEM).ES cells and endothelial-specific molecular markers were assessed by RT-PCR at different time-points.Results As self-renewal marker genes were expressed in E14 cells,E14 cells was identified to maintain their selfrenewal pluripotency.The marker gene of letarl,Flk1 was expressed on differentiation day 4.On differentiation day 8 the marker gene VE-cadherin was expressed and as observed under PCM endothelial cells with spindle shape and TEM with Weibel-Palade body,thus were the major populations generated after VEGF induction,and E14 cells were confirmed differentiated into mature endothelial cells.The expressions of genes octamer binding transcription factor 4 (Oct4),Flk1 and VE-cadherin were detected on differentiation day 2,4,6,8 and 10.Conclusions As VE-cadherin gene was expressed in monolayer on differentiation day 8,E14 cells were confirmed differentiated into endothelial cells,which would be a new therapeutic approach for cardiovascular disease.