GSE106224
Exosomal RNA may reflect placenta deficiencies and provide better biomarker in preterm birth.
Preterm birth (PTB) is defined as childbirth occurring at less than 37 completed weeks or 259 days of gestation. Premature babies have higher rates of cerebral palsy, sensory deficits, learning disabilities and respiratory illnesses that extend into adulthood. This lifelong morbidity results in high economic and social costs to families and communities. PTB is a syndrome initiated by multiple mechanisms, including infection or inflammation, uteroplacental ischaemia or haemorrhage, uterine overdistension, stress, and other immunologically mediated processes. Identifying and monitoring molecular signals in easily accessible body fluids that can diagnose or predict the risk of preterm labor in pregnant women will reduce or prevent PTBs. A number of studies reported the identification of putative biomarkers for PTB including protein, miRNA and hormone from different body fluids such as serum/plasma, cervical vaginal fluid, saliva and amniotic fluids. These putative biomarkers identified can largely be grouped into three main functional categories: inflammatory related molecules, placenta or fetal derived molecules and stress related molecules. In the past few years next generation sequencing (NGS) has become the major platform for miRNA analysis especially with body fluids. However, studies have shown significant sequence bias among different small RNA library preparation protocols. We have modified the small RNA library construction protocol which greatly reduces the sequence bias and increase miRNA coverage in sample. We also adapted a newly developed size exclusion chromatography (SEC) based EV purification protocol which can provide cleaner EVs compared to other methods. We are using these improved approaches to gain more reliable profile of circulating RNA in body fluid as well as its associated EVs. With these new approaches, we explore the possibility of using specific circulating miRNAs, specifically those encapsulated in EVs, as a noninvasive biomarker for PTB by comparing the miRNA profiles in maternal plasma, EV and EV-depleted plasma between individuals who had a spontaneous preterm birth and uncomplicated pregnancies. Overall design: Blood samples were collected from women who had spontaneous preterm births between 24-34 weeks (n=20) and matched with respect to gestational age and other variables to pregnant women with normal pregnancy (n=50).