409-P: Engineered Cardiac Tissues: A Novel In Vitro Model to Investigate the Pathophysiology of Diabetic Cardiomyopathy

Abstract

Rodent diabetic models have advanced our understanding of the pathophysiology of diabetic cardiomyopathy (DCM), however these models require long timelines to display DCM, and also display confounding influences inherent to in vivo models, but in vitro cardiomyocyte cultures could not reflect the structure-function relationship specific to the heart. Over the past 2 decades, engineered cardiac tissues (ECTs) have emerged as robust 3D in vitro models to investigate cardiac tissue maturation, structure-function relationships, cardiac injury response and repair. Advanced glycation end-products (AGEs), the proteins or lipids that become glycated in response to hyperglycemia, produce diabetes-associated tissue injury via receptor (RAGE) activating reactive oxygen or nitrogen species (ROS/RNS). Therefore, we developed a ECT model to investigate cardiac injury produced by AGEs. We used ECTs composed of neonatal murine cardiac cells and found: (1) AGEs at 150 µg/ml did not cause significant cytotoxicity (necrosis, detected by medium LDH or apoptosis, detected by c-caspase 3), but negatively impacted ECT function by 9-day treatment; (2) AGEs triggered fibrotic (Collagen I-α1, Collagen III-α1, FN1) and hypertrophic (ANP and β-MHC) responses on day 3 - 9 after treatment; (3) AGE also increased ECT’s oxidative stress (3-NT, 4-HNE, HO-1, CAT, SOD2) and inflammation (PAI-1, TNF-α, NF-κB, ICAM); (4) All AGE-induced oxidative stress, inflammation, fibrotic response and hypertrophy and ECT dysfunction were prevented by the RAGE inhibitor FPS-ZM1 or by inhibiting ROS/RNS production via NAC. Thus, AGEs-treated neonatal murine ECTs recapitulate key cellular and molecular pathophysiological features of DCM and can serve as a robust ex vivo model to investigate cell-cell specific pathways relevant to DCM along with cardioprotective strategies. This model even has a great potential to directly investigate the effect of diabetes on human ECTs if human iPSC can be introduced. Disclosure X. Wang: None. Y. Zheng: None. B.B. Keller: None. L. Cai: None.