Dysfunctional Insulin Resistant/mTOR Activation Is Involved In The Formation of Pulmonary Hypertension In Pressure Overload-Induced Heart Failure
Abstract Background: Heart failure (HF) usually presents with abnormal changes of metabolisms. Pulmonary hypertension (PH) is a frequent complication of left heart dysfunction. However, the association of serum metabolic changes with PH formation remains unknown. This study analyzed changes of serum metabolomic during the development of PH in a left heart pressure overload model. Methods: Male Sprague-Dawley rats were subjected to transverse aortic constriction (TAC) or sham surgery. Metabolomic analysis was performed on plasma samples of rats at 0 week, 3 weeks and 9 weeks after the surgery. Cardiac remodeling and heart function were determined by echocardiography. Right heart catheterization was performed to assay the mean pulmonary arterial pressure (mPAP). HE staining was performed to observe the remodeling of the myocardium and small pulmonary arteries.Results: The rats developed compensated cardiac hypertrophy with normal mPAP at 3 weeks and PH due to HF (PH-HF) at 9 weeks with distinct metabolic pattern after TAC. Twenty-five metabolites changed in the 9-week group compared with the 3-week group. KEGG analysis suggested abnormal insulin resistance and mTOR activation during the development of PH-HF. Acetylcarnitines related to insulin resistance increased about 3 folds from 4.14 ug/ml at 3 W group to 12.04μg/ml at 9-week group. L-leucine related to mTOR activation increased 1.6-fold with a VIP of 4.08 at 9 W when compared with that of the 3 W group.Conclusions: These results revealed distinct metabolic changes during the development of PH-HF. Dysfunctional insulin resistance and mTOR activation might be involved in the transition from compensated cardiac hypertrophy to PH-HF.