title: Increased afterload induces pathological cardiac hypertrophy: a new in vitro model.
abstract: Increased afterload results in 'pathological' cardiac hypertrophy, the most important risk factor for the development of heart failure. Current in vitro models fall short in deciphering the mechanisms of hypertrophy induced by afterload enhancement. The aim of this study was to develop an experimental model that allows investigating the impact of afterload enhancement (AE) on work-performing heart muscles in vitro. Fibrin-based engineered heart tissue (EHT) was cast between two hollow elastic silicone posts in a 24-well cell culture format. After 2 weeks, the posts were reinforced with metal braces, which markedly increased afterload of the spontaneously beating EHTs. Serum-free, triiodothyronine-, and hydrocortisone-supplemented medium conditions were established to prevent undefined serum effects. Control EHTs were handled identically without reinforcement. Endothelin-1 (ET-1)- or phenylephrine (PE)-stimulated EHTs served as positive control for hypertrophy. Cardiomyocytes in EHTs enlarged by 28.4 % under AE and to a similar extent by ET-1- or PE-stimulation (40.6 or 23.6 %), as determined by dystrophin staining. Cardiomyocyte hypertrophy was accompanied by activation of the fetal gene program, increased glucose consumption, and increased mRNA levels and extracellular deposition of collagen-1. Importantly, afterload-enhanced EHTs exhibited reduced contractile force and impaired diastolic relaxation directly after release of the metal braces. These deleterious effects of afterload enhancement were preventable by endothelin-A, but not endothelin-B receptor blockade. Sustained afterload enhancement of EHTs alone is sufficient to induce pathological cardiac remodeling with reduced contractile function and increased glucose consumption. The model will be useful to investigate novel therapeutic approaches in a simple and fast manner.
authors.affiliation: Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf and DZHK, Germany.
authors.forename: Marc N
authors.initials: MN
authors.lastname: Hirt
authors.forename: Nils A
authors.initials: NA
authors.lastname: Sörensen
authors.forename: Lena M
authors.initials: LM
authors.lastname: Bartholdt
authors.forename: Jasper
authors.initials: J
authors.lastname: Boeddinghaus
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schaaf
authors.forename: Alexandra
authors.initials: A
authors.lastname: Eder
authors.forename: Ingra
authors.initials: I
authors.lastname: Vollert
authors.forename: Andrea
authors.initials: A
authors.lastname: Stöhr
authors.forename: Thomas
authors.initials: T
authors.lastname: Schulze
authors.forename: Anika
authors.initials: A
authors.lastname: Witten
authors.forename: Monika
authors.initials: M
authors.lastname: Stoll
authors.forename: Arne
authors.initials: A
authors.lastname: Hansen
authors.forename: Thomas
authors.initials: T
authors.lastname: Eschenhagen
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D006332:Cardiomegaly / Q000209:etiology*; D002478:Cells, Cultured; D065128:Endothelin Receptor Antagonists; D005355:Fibrosis; D015870:Gene Expression; D006019:Glycolysis; D008954:Models, Biological; D032383:Myocytes, Cardiac / Q000502:physiology*; D051381:Rats; D011917:Rats, Inbred Lew; D017208:Rats, Wistar; D023822:Tissue Engineering
chemical_list: D065128:Endothelin Receptor Antagonists