Gene expression in rod shaped cardiac myocytes, sorted by flow cytometry

Objective: Primary cardiac myocyte cultures are usually contaminated with v ariable parts or different cell types, such as fibroblasts, endothelial cel ls and smooth muscle cells. Thus, the objective of our study was to analyse the gene expression in a pure population. Methods: To obtain an homogeneou s population, cardiac myocytes from adult rats were fixed with ethanol and sorted by flow cytometry. This approach is suitable for isolating either si ngle cells or up to several thousand cells. To measure the messenger ribonu cleic acid (mRNA) expression of different genes at the level of a few rod-s haped myocytes, a cDNA library was created by polymerase chain reaction (PC R). Results: Sorting by 3 fluorescence-activated cell sorter (FACS) resulte d in pure rod-shaped cardiac myocytes and isolated RNA from these cells is undegraded, as shown by Northern blotting. We demonstrated both the express ion of housekeeping genes, such as beta-actin and glyceraldehyde-3-phosphat e dehydrogenase (GAPDH) as well as the myocyte-specific transcripts, alpha- cardiac myosin heavy chain (alpha-MHC) and beta-MHC. Furthermore, we showed the induction of the immediately early gene c-fos at the level of ten sort ed cells. Conclusions: This method allows one to study gene expression in d ifferent cell types within the heart, in tissue samples or to tackle the pr oblem of heterogeneity within a cell population. (C) 1998 Elsevier Science B.V. All rights reserved.