The Activation of the LIMK/Cofilin Signaling Pathway via Extracellular Matrix–Integrin Interactions Is Critical for the Generation of Mature and Vascularized Cardiac Organoids

Abstract

The generation of mature and vascularized human pluripotent stem cell-derived cardiac organoids (hPSC-COs) is necessary to ensure the validity of drug screening and disease modeling. This study investigates the effects of cellular aggregate (CA) stemness and self-organization on the generation of mature and vascularized hPSC-COs and elucidates the mechanisms underlying cardiac organoid (CO) maturation and vascularization. COs derived from 2-day-old CAs with high stemness (H-COs) and COs derived from 5-day-old CAs with low stemness (L-COs) were generated in a self-organized microenvironment via Wnt signaling induction. This study finds that H-COs exhibit ventricular, structural, metabolic, and functional cardiomyocyte maturation and vessel networks consisting of endothelial cells, smooth muscle cells, pericytes, and basement membranes compared to L-COs. Transcriptional profiling shows the upregulation of genes associated with cardiac maturation and vessel formation in H-COs compared with the genes in L-COs. Through experiments with LIMK inhibitors, the activation of ROCK-LIMK-pCofilin via ECM–integrin interactions leads to cardiomyocyte maturation and vessel formation in H-COs. Furthermore, the LIMK/Cofilin signaling pathway induces TGFβ/NODAL and PDGF pathway activation for the maturation and vascularization of H-COs. The study demonstrates for the first time that LIMK/Cofilin axis activation plays an important role in the generation of mature and vascularized COs.

Exogenous and Endogenous Molecules Potentially Proficient to Modulate Mitophagy in Cardiac Disorders

“…Pyridoxal phosphatase (PDXP) is known to directly dephosphorylate the cofilin, which may be involved in mitochondrial fission and/or mitophagy [103]. The cofilin signaling pathway induces the activation of TGFβ and/or the PDGF pathway for the vascularization in pluripotent stem cell-derived cardiac organoids [104]. Some researchers have revealed that stem cells can repair damaged myocardium and/or improve heart function [105].…”