Abstract
Cardiovascular disease (CVD) is a major contributor to both mortality and disability worldwide, with numbers of cases continuously rising. While CVD is commonly thought to primarily affect men, it is a main killer amongst women as well. Despite this, women are strikingly underrepresented in research on cardiovascular health, likely leading to reduced quality in the treatment, diagnosis and prevention of female CVD. This poses an urgent need for the acknowledgement and investigation of female-specific risk factors. Preeclampsia is correlated with an increased risk for later developing cardiovascular disease, even after adjusting for common risk factors, such as obesity and high blood pressure. Preeclampsia is also associated with increased levels of fetal cells in maternal circulation during pregnancy, known as fetal microchimerism. These cells can harbor in maternal tissue, and we postulate that the fetal cells contribute to the increased CVD risk of women with a history of preeclampsia. In the present work, methods for detecting the presence of fetal cells within maternal tissue through targeting the male-specific Y-chromosome, were developed. Digital droplet PCR (ddPCR), for the detection of male DNA, was performed on atherosclerotic tissue from 15 women and 1 man, used as a positive control. Fluorescent in situ hybridization (FISH), for spatial detection of male cells within tissue, was developed using placental and decidua basalis samples, and implemented on atherosclerotic tissue from 4 postmenopausal women and 1 man. Both ddPCR and FISH successfully demonstrated XY-positive cells in male atherosclerotic tissue. No male DNA was detected within female atherosclerotic tissue using ddPCR. Using FISH, a single XY-positive cell was detected in plaque from one female. Further validation of the present fetal microchimerism detection in atherosclerotic tissue is needed through excluding the possibility of false positives, investigating larger areas of tissue and increasing sample size. For ddPCR, sufficient DNA yield is necessary for fetal cell detection and thus a step that needs to be optimized. Further optimization of the FISH protocol may be carried out to yield improved and consistent fluorescent signals. Improvement of these methods as well as studying other cellular markers may elucidate the role of the ever-enigmatic fetal microchimerism in atherosclerosis and cardiovascular disease.