title: Cardiomyocyte loss is not required for the progression of left ventricular hypertrophy induced by pressure overload in female mice.
abstract: Left ventricular (LV) hypertrophy in response to hypertension and increased afterload frequently progresses to heart failure. It is under debate whether the loss of cardiomyocytes contributes to this transition. To address this question, female C57BL/6 wild-type mice were subjected to transverse aortic constriction (TAC) and developed compensated LV hypertrophy after 1 week, which progressed to heart failure characterized by reduced ejection fraction and pulmonary congestion 4 weeks post-TAC. Quantitative, design-based stereology methods were used to estimate number and mean volume of LV cardiomyocytes. DNA strand breaks were visualized using the TUNEL method 6 weeks post-TAC to quantify the number of apoptotic cell nuclei. The volume of the LV myocardium as well as the cardiomyocyte mean volume increased progressively after TAC. In contrast, the number of LV cardiomyocytes remained constant 1 and 4 weeks post-TAC in comparison to sham-operated mice. Moreover, there was no significant difference in the number of cardiomyocyte nuclei stained for DNA strand breaks at 6 weeks post-TAC. It was concluded that the loss of cardiomyocytes is not required for the transition from compensated hypertrophy to heart failure induced by TAC in the female murine heart.
authors.affiliation: Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Schipke
authors.affiliation: Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.
authors.forename: Clara
authors.initials: C
authors.lastname: Grimm
authors.affiliation: Division of Cardiology, Medical University of Graz, Graz, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Arnstein
authors.affiliation: Institute of Pharmacology and Clinical Pharmacy, Philipps-University of Marburg, Marburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Kockskämper
authors.affiliation: Division of Cardiology, Medical University of Graz, Graz, Austria.
authors.forename: Simon
authors.initials: S
authors.lastname: Sedej
authors.affiliation: Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.|Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany.|Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Mühlfeld
mesh_terms: D000818:Animals; D017209:Apoptosis; D002452:Cell Count; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D017379:Hypertrophy, Left Ventricular / Q000473:pathology*; D008810:Mice, Inbred C57BL; D032383:Myocytes, Cardiac / Q000473:pathology*; D011312:Pressure
keywords: apoptosis; cardiomyocyte number; design-based stereology; hypertrophy; transverse aortic constriction