Gene Expression Changes in Human Dermal Fibroblasts Exposed to Fluid Flow

Introduction. Fibroblasts are an attractive target for drug testing and personalized medicine due to ease of harvest and expansion. Fibroblasts are known to change phenotype upon exposure to interstitial and vascular fluid... [ view full abstract ]

Introduction. Fibroblasts are an attractive target for drug testing and personalized medicine due to ease of harvest and expansion. Fibroblasts are known to change phenotype upon exposure to interstitial and vascular fluid flow levels. This study sought to more fully investigate the effect of fluid flow on dermal fibroblasts to assess the feasibility of their differentiation into cells of vascular relevance for drug-screening platforms.

Methods. Human dermal fibroblasts (HDFs) were maintained in static culture or exposed to fluid flow in a parallel plate flow chamber (10dyn/cm2 for 20hrs and 40hrs). RNA was isolated using mirVana Kit and analyzed on a GeneChip® Human Transcriptome Array 2.0. Microarray analysis was performed with RMA normalization, fold change >2 or <-2, p-value <0.01. The expression of genes of interest were confirmed with qPCR. Viability tests were done with live/dead staining.

Results. Live/dead staining revealed that over 90% of cells remained alive and adherent after 40hrs of fluid flow exposure. Gene expression changed with time of shear exposure. Fluid flow affected more than 600 genes in Static vs 20hrs Flow and over 300 genes in Static vs 40hrs Flow. Genes involved in vascular development, migration, and inflammation were modulated.

Conclusions. Fluid shear stress modulated many fibroblast genes in a time-dependent manner, including genes involved in differentiation into vascular cells, migration and inflammation. Studies are ongoing to assess phenotypic changes these cells are undergoing upon exposure to fluid flow and further assess feasibility of differentiation into cardiac and vascular cells relevant for drug-screening platforms.