Gene expression profiles in engineered cardiac tissues respond to mechanical loading and inhibition of tyrosine kinases

Abstract

Engineered cardiac tissues (ECTs) are platforms to investigate cardiomyocyte maturation and functional integration, the feasibility of generating tissues for cardiac repair, and as models for pharmacology and toxicology bioassays. ECTs rapidly mature in vitro to acquire the features of functional cardiac muscle and respond to mechanical load with increased proliferation and maturation. ECTs are now being investigated as platforms for in vitro models for human diseases and for pharmacologic screening for drug toxicities. We tested the hypothesis that global ECT gene expression patterns are complex and sensitive to mechanical loading and tyrosine kinase inhibitors similar to the maturing myocardium. We generated ECTs from day 14.5 rat embryo ventricular cells, as previously published, and then conditioned constructs after 5 days in culture for 48 h with mechanical stretch (5%, 0.5 Hz) and/or the p38 MAPK (p38 mitogen-activated protein kinase) inhibitor BIRB796. RNA was isolated from individual ECTs and assayed using a standard Agilent rat 4 × 44k V3 microarray and Pathway Analysis software for transcript expression fold changes and changes in regulatory molecules and networks. Changes in expression were confirmed by quantitative-polymerase chain reaction (q-PCR) for selected regulatory molecules. At the threshold of a 1.5-fold change in expression, stretch altered 1559 transcripts, versus 1411 for BIRB796, and 1846 for stretch plus BIRB796. As anticipated, top pathways altered in response to these stimuli include cellular development, cellular growth and proliferation; tissue development; cell death, cell signaling, and small molecule biochemistry as well as numerous other pathways. Thus, ECTs display a broad spectrum of altered gene expression in response to mechanical load and/or tyrosine kinase inhibition, reflecting a complex regulation of proliferation, differentiation, and architectural alignment of cardiomyocytes and noncardiomyocytes within ECT.

Electrical and mechanical stimulation of cardiac cells and tissue constructs

“…1). The above-mentioned methods have also been used to elucidate the role of mechanical signaling in hypertrophic signaling in both a physiological and pathological context [208,209]. In this section, a review of the relevant literature focuses on efforts to enhance CM function and phenotype via mechanical stimulation as well as studies aimed at utilizing mechanical stimulation as a tool to understand hypertrophic signaling in CMs (Note: for a more complete review, see Zimmermann et al in this issue or Tallawi et al [210]).…”

3D bioprinted functional and contractile cardiac tissue constructs

“…Rhythmic mechanical stretching was also reported to increase cardiomyocyte proliferation and maturation in bioengineered tissues [31]. Thus, the tissue development of bioprinted cardiac tissues implied not only the changes in cells and ECM components, but also in biomechanical properties of bioprinted cardiac tissues.…”

Transcriptome profiling of 3D co-cultured cardiomyocytes and endothelial cells under oxidative stress using a photocrosslinkable hydrogel system

“…FGD5 protein was reported to play a crucial role in vascular pruning processes, and to inhibit neovascularization [45]. AREG protein is a member of epidermal growth factor (EGF) family and was reported to have an increase in its expression when the cardiac tissue was loaded with mechanical stretch [46] and can promote cell proliferation through interaction with the EGF/TGF-α receptor. SFRP2 protein is a Wnt signal modulator and was reported to be a key paracrine factor, which was responsible for CM survival and repair after ischemic injury [47].…”