AGGF1 is an angiogenic factor with therapeutic potential to treat coronary artery disease (CAD) and myocardial infarction (MI). However, the underlying mechanism for AGGF1-mediated therapeutic angiogenesis is unknown. Here, we show for the first time that AGGF1 activates autophagy, a housekeeping catabolic cellular process, in endothelial cells (ECs), HL1, H9C2, and vascular smooth muscle cells. Studies with Atg5 small interfering RNA (siRNA) and the autophagy inhibitors bafilomycin A1 (Baf) and chloroquine demonstrate that autophagy is required for AGGF1-mediated EC proliferation, migration, capillary tube formation, and aortic ring-based angiogenesis. Aggf1+/- knockout (KO) mice show reduced autophagy, which was associated with inhibition of angiogenesis, larger infarct areas, and contractile dysfunction after MI. Protein therapy with AGGF1 leads to robust recovery of myocardial function and contraction with increased survival, increased ejection fraction, reduction of infarct areas, and inhibition of cardiac apoptosis and fibrosis by promoting therapeutic angiogenesis in mice with MI. Inhibition of autophagy in mice by bafilomycin A1 or in Becn1+/- and Atg5 KO mice eliminates AGGF1-mediated angiogenesis and therapeutic actions, indicating that autophagy acts upstream of and is essential for angiogenesis. Mechanistically, AGGF1 initiates autophagy by activating JNK, which leads to activation of Vps34 lipid kinase and the assembly of Becn1-Vps34-Atg14 complex involved in the initiation of autophagy. Our data demonstrate that (1) autophagy is essential for effective therapeutic angiogenesis to treat CAD and MI; (2) AGGF1 is critical to induction of autophagy; and (3) AGGF1 is a novel agent for treatment of CAD and MI. Our data suggest that maintaining or increasing autophagy is a highly innovative strategy to robustly boost the efficacy of therapeutic angiogenesis.

SummaryRecent genome-wide single nucleotide polymorphism (SNP) association studies (GWAS) have identified a number of SNPs that were significantly associated with coronary artery disease and myocardial infarction (MI). However, many independent replication studies in other populations are needed to unequivocally confirm the GWAS association. To assess GWAS association, we have established a case-control cohort consisting of 1231 well-characterised MI patients and 560 controls without detectable coronary stenosis, all selected from the Cleveland Genebank population. The Genebank cohort has sufficient power to detect the association between MI and four GWAS SNPs, including rs17465637 within the MIA3 gene, rs2943634 (intergenic), rs6922269 in MTHFD1L, and rs599839 near SORT1. SNPs were genotyped by TaqMan assays and follow-up multivariate logistic regression analysis with incorporation of significant covariates showed significant association with MI for MIA3 SNP rs17465637 (P-adj = 0.0034) and SORT1 SNP rs599839 (P-adj = 0.009). The minor allele G of rs599839 was also associated with a decreased LDL-C level of 5-9 mg/dL per allele, but not with HDL-C or triglyceride levels. No association for MI or lipid levels was found for SNPs rs2943634 and rs6922269 (P-adj > 0.05). Our results establish two SNPs, rs17465637 in MIA3 and rs599839 near SORT1 as significant risk factors for MI in the American Genebank Caucasian population.

Background:Certain nonmammalian species such as zebrafish have an elevated capacity for innate heart regeneration. Understanding how heart regeneration occurs in these contexts can help illuminate cellular and molecular events that can be targets for heart failure prevention or treatment. The epicardium, a mesothelial tissue layer that encompasses the heart, is a dynamic structure that is essential for cardiac regeneration in zebrafish. The extent to which different cell subpopulations or states facilitate heart regeneration requires research attention.Methods:To dissect epicardial cell states and associated proregenerative functions, we performed single-cell RNA sequencing and identified 7 epicardial cell clusters in adult zebrafish, 3 of which displayed enhanced cell numbers during regeneration. We identified paralogs ofhapln1as factors associated with the extracellular matrix and largely expressed in cluster 1. We assessedHAPLN1expression in published single-cell RNA sequencing data sets from different stages and injury states of murine and human hearts, and we performed molecular genetics to determine the requirements forhapln1-expressing cells and functions of eachhapln1paralog.Results:A particular cluster of epicardial cells had the strongest association with regeneration and was marked by expression ofhapln1aandhapln1b. Thehapln1paralogs are expressed in epicardial cells that enclose dedifferentiated and proliferating cardiomyocytes during regeneration. Induced genetic depletion ofhapln1-expressing cells or genetic inactivation ofhapln1baltered deposition of the key extracellular matrix component hyaluronic acid, disrupted cardiomyocyte proliferation, and inhibited heart regeneration. We also found thathapln1-expressing epicardial cells first emerge at the juvenile stage, when they associate with and are required for focused cardiomyocyte expansion events that direct maturation of the ventricular wall.Conclusions:Our findings identify a subset of epicardial cells that emerge in postembryonic zebrafish and sponsor regions of active cardiomyogenesis during cardiac growth and regeneration. We provide evidence that, as the heart achieves its mature structure, these cells facilitate hyaluronic acid deposition to support formation of the compact muscle layer of the ventricle. They are also required, along with the function ofhapln1bparalog, in the production and organization of hyaluronic acid–containing matrix in cardiac injury sites, enabling normal cardiomyocyte proliferation and muscle regeneration.

Background Many health policy experts have endorsed insurance competition as a way to reduce the cost and improve the quality of medical care. In line with this approach, health insurance exchanges, such as HealthCare.gov, allow consumers to compare insurance plans online. Since the 2013 rollout of HealthCare.gov, administrators have added features intended to help consumers better understand and compare insurance plans. Although well-intentioned, changes to exchange websites affect the context in which consumers view plans, or choice architecture, which may impede their ability to choose plans that best fit their needs at the lowest cost. Methods By simulating the 2016 HealthCare.gov enrollment experience in an online sample of 374 American adults, we examined comprehension and choice of HealthCare.gov plans under its choice architecture. Results We found room for improvement in plan comprehension, with higher rates of misunderstanding among participants with poor math skills (P < 0.05). We observed substantial variations in plan choice when identical plan sets were displayed in different orders (P < 0.001). However, regardless of order in which they viewed the plans, participants cited the same factors as most important to their choices (P > 0.9). Limitations Participants were drawn from a general population sample. The study does not assess for all possible plan choice influencers, such as provider networks, brand recognition, or help from others. Conclusions Our findings suggest two areas of improvement for exchanges: first, the remaining gap in consumer plan comprehension and second, the apparent influence of sorting order – and likely other choice architecture elements – on plan choice. Our findings inform strategies for exchange administrators to help consumers better understand and select plans that better fit their needs.