Chan, STH

Ho, PC

Xu, JS

Yeung, WSB

Hong Kong Medical Journal

HKU Scholars Hub

Title Human oviductal cells produces three glycoprotein fractionsthat stimulate mouse embryo developmentAuthor(s) Xu, JS; Chan, STH; Ho, PC; Yeung, WSBCitationThe 2nd International Huazia Congress of Endocrinology, HongKong, 14-17 December 2001. In Hong Kong Medical Journal,2001, v. 7 suppl. 2, p. 51, abstract no. 032Issued Date 2001URL http://hdl.handle.net/10722/54221Rights Hong Kong Medical Journal. Copyright © Hong Kong MedicalAssociation.HKMJ Vol 7 No 4 December 2001 Supplement 2      51HUMAN CHORIONIC GONADOTROPHIN (HCG) STIMULATESVASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) PRODUCTION BYLEYDIG CELLSAU Chak Leung, SY Chun Choi, CHAN Lai FongDepartment of Physiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong.Objective:  To examine whether the Leydig cell production of a potent angiogenic factor - VEGF, is under thetrophic stimulation of hCG, and if so whether the effect can be mimicked by activators of the second messengerpathways involved in mediating hCG actions.  Methods:  Percoll-purified Leydig cells (LC) and mouse Leydig celllines (TM3 and MLTC-1) were used, and they were studied at different time intervals following the exposure tohCG, 8-bromo-cAMP, forskolin and phorbol-12-myristate-13-acetate (PMA).  The culture medium was collectedfor the measurement of VEGF by ELISA and total RNA was extracted from cells for the quantification of VEGFmRNA levels by Northern blot analysis.  Results:  hCG (0.001-1 U/ml) produced a modest dose-dependent stimulationof VEGF secretion from rat LC and MLTC-1 cells, reaching a maximum of ~50% above the basal levels.  TM3 cellsfailed to respond to hCG (due to the loss of LH receptors) but gave dose-dependent increase in VEGF secretionfollowing 12 h incubation with 8-bromo-cAMP (0.1-3 mM) and PMA (0.01-1 µM).  Similar results were obtainedfrom rat LC and MLTC-1 cells which gave maximum responses of >100% increase above the control.  In line withthe changes in peptide secretion, VEGF mRNA levels in MLTC-1 cells were upregulated ~1.5-fold after 2 h exposureto hCG (0.01-1U/ml).  For TM3 cells, their VEGF mRNA levels showed time- and dose-dependent increases inresponse to forskolin (0.1-10 µM) and PMA (0.01-3 µM), with the later producing a greater stimulation.  Conclusions:VEGF peptide secretion and mRNA expression in Leydig cells are stimulated by hCG which may produce its effectthrough both the protein kinase A and C pathways.  The hCG-induced increase in VEGF production from Leydigcells could account for the increase in endothelial cell proliferation in the testis of adult rats after receiving hCGinjection.  Acknowledgement: Supported by RGC Grant (CUHK 422/95M).Human oviductal cells produces three glycoprotein fractions that stimulate mouseembryo developmentJia-Sen Xu1, Samuel Ting-Hon Chan2, Pak-Chung Ho1, and William Shu-Biu Yeung11Departments of Obstetrics and Gynaecology, and 2 Zoology, University of Hong Kong, Hong Kong SAR, ChinaObjective: The development of preimplantation (PI) mammalian embryos in vitro is inferior to that of  in vivo.Lack of oviductal support is one of the possible reasons for the suboptimal embryo development in vitro. Cocultureof embryos with oviductal cells suggests that paracrine pathway(s) exists between oviduct and PI embryos. Wehave demonstrated that coculture with human oviductal cells improves human and mouse embryo development interms of increase in blastocyst formation, hatching and implantation rate, decrease in the incidence of cytoplasmicfragmentation and apoptosis. This study aims to study the embryotropic effects of three glycoprotein fractions fromhuman oviductal cell conditioned medium on mouse embryo development.Methods: Human oviductal cells were obtained from donated oviducts of hysterectomy patients and were culturedin DMEM/F12.  The oviductal cell conditioned medium was fractionated by various liquid chromatographic systems.The purified fractions were tested on mouse embryos (MF1 x BALB/c) at different stages of development fordifferent duration.   Their effects on blastulation, hatching and allocation of cells to inner cell mass (ICM) andtrophectoderm (TE) in the resulting blastocysts were determined.Results: Three glycoprotein fractions named ETF-1, 2 and 3 with embryotropic effect on mouse embryo developmentwere purified from the conditioned medium after human oviductal cells culture. ETF-1 and 2 affected the embryosat early cleavage stage and increased ICM cell number of the resulting blastocysts. ETF-3 stimulated the developmentof TE and had its maximal effects at around compaction.  The enhanced development of TE after ETF-3 treatmentled to larger expanded blastocysts with higher hatching rate.Conclusion: Our studies showed that human oviductal cells improved mouse embryo development partly by theproduction of high-molecular-weight embryotropic factors. These factors had differential effects on mouse embryodevelopment.Acknowledgement: The Research Grant Council, Hong Kong (HKU241/95M) supports this research.O31O32

Human oviductal cells produces three glycoprotein fractions that stimulate mouse embryo development

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Human oviductal cells produces three glycoprotein fractions that stimulate mouse embryo development

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