The micro-RNAome in cord blood of babies born small-for-gestational age

Children born after fetal growth restriction (FGR) have an increased risk of neonatal morbidity and mortality as well as an increased risk of morbidity later in life, especially in the spectrum of the metabolic syndrome. FGR can be caused of many different things. There are both genetic causes and causes from the environment, which makes FGR a heterogenic condition. FGR most often results in the birth of a child that is small for gestational age (SGA).

The growth and the development of the fetus are governed by which genes are expressed in different tissues. The environment can influence gene expressions by epigenetic mechanisms. One epigenetic mechanism is the production of microRNAs (miRNAs), who mainly act by inhibiting mRNAs to produce proteins. In that way, miRNAs regulate almost 30 % of all human genes and they influence all fundamental cell processes.

Animal studies have shown changes in the miRNA expression in different fetal tissues including cord blood, after induced, experimental FGR. But, as far as we know, there is no study reporting miRNA expressions in human cord blood of children born SGA. However, miRNAs can be found in the blood circulation and are found to be stable there. Analyzing miRNA expressions in cord blood will give a picture of fetal miRNA expressions.

In this research project, the total miRNA expression (the miRNAome) in cord blood will be examined for the first time in children born SGA in comparison with control groups.

The overall propose of this project is to increase our knowledge on molecular biological mechanisms behind pathological SGA births, in order to increase the possibility of introducing new and better treatments for these patients.

From a collection of about 10,000 cord blood samples at the University Hospital in Örebro we have identified samples fulfilling stringent inclusion but no exclusion criteria. These samples will be analyzed for all miRNAs using Next Generation Sequencing. The data gathered will be processed using bioinformatic technics and then reported in a scientific article.