| Congenital heart disease(CHD) is a kind of disease that brings serious damage to human health,and it’s mainly caused by genetic factors and environmental factors. Despite great progress has been made in the past few decades,people can still hardly understand its pathogenesis enough, particularly on environmental factors’ affects on the development of heart.It has been proved by some research that early intrauterine pregnancy viral infection is one of the most important environmental factors.Clinical epidemiology survey reveals that 15 species of early intrauterine viral infections can cause cardiac abnormalities, but there is no experiment proves that the relationship between them.Therefore it is very important to study influenza virus’ s affects on heart development-related genes.In this study, Purebred KM mice of SPF level were chosen as experimental animals, by way of the establishment of a stable H1N1 influenza virus infection mice model, by means of morphological observation and in situ hybridization, and by treating BMP signaling pathway as the research object, members of BMP signaling pathway and changes of the expression of part cardiac marker genes were verified and analyzed from the level of gene expression. The main results and conclusions obtained in this study are as follows:(1)According to the development time of mouse embryonic heart, infection was carried out on the 7.5th day of pregnancy, building the model of mouse infected by H1N1 flu virus. Then the morphological observation and analysis of embryos of pregnant mice infected by virus and controls were made, unveiling that the development of embryos infected by virus were delayed and hearts development were abnormal.(2) During the detection of whole-mount embryo in situ hybridization, it was found that BMP signal members BMP4/5/7 and BAMBI all were significantly reduced expression in the early stage of heart development.(3) During detection by situ hybridization at 9.5 and 10.5 days post coitum,it was found that in virus infected embryos,the expression of Nkx2.5,which is the key regulatory factor to heart development,were significantly reduced in both 2 periods, indicating that heart development was affected by flu virus infection.(4) During detection by situ hybridization,it was found that at 10.5 and 11.5 days post coitum in virus infected embryos,the expression of the second heart field(SHF) marker factors Isl1,were significantly reduced in Right Ventricular and Outflow Tract,and it was the same to Fgf10 at 10.5 or 11.5 days post coitum,indicating that second heart field(SHF) development was affected by flu virus infection.(5) During further detection of the expression of the chamber specialized factors MLC2 a and ehand,it was found that MCL2 a was reduced in virus infected embryos at 9.5 days post coitum,ehand was significantly reduced in Left Ventricular field of virus infected embryos at 10.5 and 11.5 days post coitum,indicating influenza virus would affect development of heart chambers.In summary, preliminary affirmative conclusion can be made that the influenza virus can truly affect heart development by disturbing BMP signal and the expression of significant heart development factors like Nkx2.5, Isl1, Fgf10, MLC2 a and ehand in the early stage of heart development. |
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