echocardiographic analysis

Transaortic constriction (TAC) was done in 12-weeks-old mice. Pre-anesthetic and anesthetic agents are listed in Supplemental Table S2. The intervention was performed by tying a braided 5–0 polyviolene suture (Hugo Sachs Electronik) ligature around the aorta and a blunted 26-gauge needle and subsequent removal of the needle. For sham controls, the suture was not tied. To determine the level of pressure overload by aortic ligation, a high frequency Doppler probe was used to measure the ratio between blood flow velocities in right and left carotid arteries. TAC mice with blood flow gradient <60% were excluded. For echocardiography, mice were anesthetized by 2.4% isoflurane inhalation and ventricularmeasurementswere done with aVisual-Sonics Vevo 2100 Imaging System equipped with a MS400, 30 MHz MicroScan transducer. The observer was unaware of the genotypes and treatments. All these procedures were performed by the SFB 1002 service unit (S01 Disease Models). All animal experiments were approved by the Niedersachsen (AZ-G 15-1840) animal review board.