Studies On The Role Of E-cadherin In The Implantation Of Human Embryo And The Regulated Mechanism By Nitric Oxide And Interleukin-1

Studies on the Role of E-cadherin in the Implantationof Human Embryo and the Regulated Mechanismby Nitric Oxide and Interleukin-1Postgraduate StudentLiu YunTutorial ProfesserXing FuqiChen ShilingABSTRACTObjectives:(1) To investigate the role of calcium dependent adhesion molecules (cadherin), which establish molecular links between adjacent cells, during the implantation of human embryo by studying the expression of Ecadherin in human endometrium and embryo and comparing the different expression between fertile and infertile women. (2) To Study the influence of nitric oxide (NO) and interleukin- I (IL- 1) on the expression of E-cadherin in human endometrial glandular cells. (3) To investigate the effect of nitric oxide synthase (NO 5) inhibitor and interleukin- 1 receptor antagonist on the intracellular free calcium concentration of cultured human endometrial cells.Methods:(1) Immunohistochemistry were used to detect the expression of E-cadherin in endometrium from 37 fertile women with regular menses and 35 infertile women during different menstrual phases. The expression of E-cadherin in preimplantation embryos (n=24) and blastocysts (n=6) was detected by indirect immunofluorescence assay and quantitated by laserscanning confocal microscopy. (2) Human endometrium glandular cells were obtained from patients (n= 12) in the implantation windo ~v phase during endometrium biopsy, and were cultured in vitro for 24 hours. The cultured cells were incubated with L-NAME (an inhibitor of NO synthase) or IL-Ira (IL-I receptor antagonist) for 24 hours. The expression of E-cadherin wasdetected by using the flow cytometric analysis. (3) Human endometrialcells were obtained from patients (n=8) in the implantation window phase oftheir cycle during endometrium biopsy, and were cultured in vitro' After 24hours of culture, the cells were incubated with Fluo-3-AM, and then werestimulated by L-NAME or IL-lra. The dynamic change of intracellular freecalcium concentration ([Ca'+li ) were determined by the laser scanningconfocal microscopyResults: (l) In fertile women, E-cadherin exPressed in glandularepithelial cells thIough the menstrual cycle and the expression of E-cadherinwas the highe5t in "implantation window" phase. In infertile women, theexpression of E-cadherion in glandular epithelium of "imPlalltation window"phase was significant1y lower than that in fertile women (P<0.05) and nospike was found. There was no mpression of E-cadherin in the stromal cellsthIough menstrual phases of fertile and infertile women. all studiedpreimplantation embryos and blastocyst were found exPessing E-cadherin.The exPression was higher in blastocyst than that in preimPlantation embryos(P<0.05). (2) The exPression of E-cadherin in both the LNAME group andthe ir-lra grOup was significantly lower than that of the control (P<0.05). (3)Aner the addition of L-NAME, [Caz+li was itnrnediately increased, andreached its peak value at 400 second. At 900 second [Ca>]i was slightlydecreased, tf 3n risen again and maintained at a hi8h level within the testingperiod. In addition, it was observed that there were tWo differellt kinds ofcurves. While after the addition of ir-lra, [Ca'+]i was increased slow1y andgradually. The increasing range of [Ca'+]i in this group was lower than that ofL-NAME group.ConcIusions (l) It was suggested that E-cadherin was critical fOr theadhesion and implantation of the blastocySt. The abnormal exPression of E-cadherin would be one of the imPortant factors of implantaion failure. (2)ON and K-l could influence the expression of E-cadherin in endometrium. Itis possible that estrogen and progesterone regUlate the erpression mediatedby NO or R-l. (3) L-NM and In-l could Promote the releasing of- 6 -intracellular calcium from organelle of endometrial cells.