Gene Expression Analysis in Cardiac and Adipose Derived Fibroblasts: potential influence of origin and in vitro culture

Cardiac fibroblasts represent one major cell population in the heart, and are responsible for many important cardiac functions. They also arise from different cardiac lineages, suggesting that they are primed to transdifferentiation, and may be directly involved in cardiogenesis. The objective of this study was to achieve a detailed analysis of the transcriptional activity of human cardiac fibroblasts, derived from right and left atrium, assuming a possible contribution of the fibroblast population in cardiac development. Cardiac samples were collected, both from adult patients, suffering from coronary and valvular heart disease, and from infant patients suffering from congenital heart disease. Control fibroblasts from adipose tissue, of the same patient, were cultured as a reference. Gene expression was evaluated by reverse transcriptase quantitative polymerase chain reaction (RTqPCR), and subsequently subjected to data analysis. The gene expression was compared between cardiac, and adipose-derived fibroblasts. In addition, the results were analysed according to age, and different cell passages. Gene expression comparison between atrial cardiac fibroblasts (CF) and their respective adipose tissue fibroblasts (AF), show that certain cardiac transcription factors, such as GATA5, are only expressed in CFs and absent in AFs. Only in children, the same occurs for GATA4 and WT1. However, typical fibroblast markers like CD90 or DDR2, seem to have a higher expression level in AFs. Age-dependent effects are small if any. Passage 0 (P0) fibroblasts, usually show higher gene expression levels than passage 2 (P2) fibroblasts. Interestingly, in vitro cell culture appears to affect gene expression. Therefore, it is important to use unbiased approaches for gene expression analysis such as directly use ex vivo purified cardiac fibroblasts. Further gene expression studies, focused on diagnoses, may contribute togene interference in cell culture differences. The eventual possibility of using fibroblasts in cardiac regeneration strongly encourages further research in this area