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The key biological "drivers" that are responsible for reverse left ventricle (LV) remodeling are not well understood. To gain an understanding of the role of the autophagy-lysosome pathway in reverse LV remodeling, we used a pathophysiologically relevant murine model of reversible heart failure, wherein pressure overload by transaortic constriction superimposed on acute coronary artery (myocardial infarction) ligation leads to a heart failure phenotype that is reversible by hemodynamic unloading. Here we show transaortic constriction + myocardial infarction leads to decreased flux through the autophagy-lysosome pathway with the accumulation of damaged proteins and organelles in cardiac myocytes, whereas hemodynamic unloading is associated with restoration of autophagic flux to normal levels with incomplete removal of damaged proteins and organelles in myocytes and reverse LV remodeling, suggesting that restoration of flux is insufficient to completely restore myocardial proteostasis. Enhancing autophagic flux with adeno-associated virus 9-transcription factor EB resulted in more favorable reverse LV remodeling in mice that had undergone hemodynamic unloading, whereas overexpressing transcription factor EB in mice that have not undergone hemodynamic unloading leads to increased mortality, suggesting that the therapeutic outcomes of enhancing autophagic flux will depend on the conditions in which flux is being studied., Competing Interests: This study was supported by research funds from the National Institutes of Health (R01HL147968, R01 HL155344), the Veterans Administration (AN # 4345132), and the Wilkinson Foundation to Dr Mann. Dr Diwan was supported by grants from the National Institutes of Health (HL107594, HL143431, and NS094692) and the Department of Veterans Affairs (I01BX004235). Dr Finck was supported by grants from the National Institutes of Health (R01 HL119225, P30 DK05634). Dr Kovacs was supported by grants from the National Institutes of Health (S10 OD028597). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Relaxin is a pleiotropic hormone shown to confer cardioprotection in several preclinical models of cardiac ischemia-reperfusion injury. In the present study, the effects of up-regulating relaxin family peptide receptor 1 (RXFP1) via adeno-associated virus serotype 9 (AAV9) vectors were investigated in a mouse model of myocardial infarction. AAV9-RXFP1 vectors were generated and injected in adult male CD1 mice. Up-regulation of Rxfp1 was confirmed via quantitative polymerase chain reaction, and overexpressing animals showed increased sensitivity to relaxin-induced ventricular inotropic response. Overexpressing animals also demonstrated reduced infarct size and preserved cardiac function 24 hours after ischemia-reperfusion. Up-regulation of RXFP1 via AAV9 vectors has potential therapeutic utility in preventing adverse remodeling after myocardial infarction., Competing Interests: This study was supported by the American Heart Association (grant 18PRE33990001 to Mr Devarakonda), the Wright Center for Clinical and Translational Research Center (Wright Scholarship to Mr Devarakonda), and the National Institutes of Health (grants R01HL142281, R21AG053654, R01HL133167, and R35HL155651 to Dr Salloum). The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2022 The Authors.)

Heart failure is an important, and growing, cause of morbidity and mortality. Half of patients with heart failure have preserved ejection fraction, for whom therapeutic options are limited. Here we report that cardiac bridging integrator 1 gene therapy to maintain subcellular membrane compartments within cardiomyocytes can stabilize intracellular distribution of calcium-handling machinery, preserving diastolic function in hearts stressed by chronic beta agonist stimulation and pressure overload. This study identifies that maintenance of intracellular architecture and, in particular, membrane microdomains at t-tubules, is important in the setting of sympathetic stress. Stabilization of membrane microdomains may be a pathway for future therapeutic development., (© 2020 The Authors.)

Mutations in the gene encoding for dystrophin leads to structural and functional deterioration of cardiomyocytes and is a hallmark of cardiomyopathy in Duchenne muscular dystrophy (DMD) patients. Administration of recombinant adeno-associated viral vectors delivering microdystrophin or ribonucleotide reductase (RNR), under muscle-specific regulatory control, rescues both baseline and high workload-challenged hearts in an aged, DMD mouse model. However, only RNR treatments improved both systolic and diastolic function under those conditions. Cardiac-specific recombinant adeno-associated viral treatment of RNR holds therapeutic promise for improvement of cardiomyopathy in DMD patients., (© 2019 The Authors.)

Individual patients with life-threatening or severely debilitating diseases can petition the U.S. Food and Drug Administration (FDA) through their physicians to have expanded access (EA) to drugs that are in clinical trials but have not reached full FDA approval (the "single-patient" investigational new drug [IND] application). Additionally, recent state and federal laws-so-called "right to try legislation"-allow patients to approach drug companies directly for access prior to FDA approval. While these pathways provide potential access for individual patients to investigational drugs, different EA pathways permit entire groups of certain patients to access investigational drugs prior to FDA approval. This review focuses on special categories of EA INDs intended for multiple patients-the intermediate-group IND and the widespread-treatment IND-as well as emergency authorization for use of investigational drugs and biological products (e.g., vaccines) in public health emergencies.