IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
- hCG regulates IP-10 expression through histone methylation on in human endometrial stromal cells.
Autor/es:
Y. YANG-HARTWICH, R. RAMHORST, E. GRASSO,S. DUROSIER, P ALDO, G. MOR
Lugar:
Maryland
Reunión:
Congreso; 36th Meeting of the American Society for Reproductive Immunology; 2016
Institución organizadora:
The American Society for Reproductive Immunology
Resumen:
Problem : Human chorionic gonadotropin (hCG) is an immune regulatorpreven􀦞ng T- cell migra􀦞on and ac􀦞va􀦞on. The decidua plays amajor role in immune cell migra􀦞on, especially T- cell migra􀦞on. IP- 10is a major T- cell chemoa􀂂ractant, and elevated levels due to infec-􀦞on are associated with adverse pregnancy outcomes. However, themechanism that regulates chemokines and immune cell migra􀦞on inthe decidua is unknown. Studies suggest that epigene􀦞c regula􀦞on isan important immune mechanism. The PRC2 complex (of which EZH2is the func􀦞onal enzyme) is the main protein complex regula􀦞ng histonemethyla􀦞on, which silences target genes by binding to DNA. Wehypothesize that hCG immune regula􀦞on occurs by chemokine repressionin the decidua. In this study we demonstrate that hCG, through thePRC2 complex, enhances histone methyla􀦞on (resul􀦞ng in H3K27me3),which then binds to a specific loca􀦞on in the promoter of IP- 10, repressingIP- 10 expression. Modifica􀦞ons in histone methyla􀦞on can decreasehistone binding, leading to IP- 10 expression and pregnancy loss.Method of Study : In vitro studies were done using the human endometrialstromal cell line (hESC). IP- 10 and EZH2 expression were determinedby quan􀦞ta􀦞ve PCR and WB analysis. T- cell migra􀦞on assayswere performed using the two- chamber migra􀦞on assay comparingcondi􀦞oned media from stromal cells and decidualized stromal cells.Chroma􀦞n immunoprecipita􀦞on was performed to determine thebinding region of H3K27me3 by PCR. Organ cultures were preparedfrom freshly isolated human decidua 􀦞ssue (non labor). Expressionand secre􀦞on of IP- 10 in decidua 􀦞ssue was determined by quan􀦞ta-􀦞ve PCR and ELISA.Results : hCG- inhibits IP- 10 expression by inducing H3K27me3 histonemethyla􀦞on, which binds to Region 4 (505?601 bp upstream)of the IP- 10 promoter, thereby suppressing IP- 10 expression. hCGinducedhistone methyla􀦞on is through EZH2, the major func􀦞onalmember of the PRC2 complex. T- cell migra􀦞on is decreased towardscondi􀦞oned media from decidualized stromal cells compared to nondecidualizedstromal cells. LPS treatment reverses the hCG inhibitoryeffect increasing IP- 10 expression/secre􀦞on and enhancing therecruitment of CD8+ cells. These findings were validated using anorgan culture of freshly isolated human decidua 􀦞ssue.