Transcriptional Impact of Pro-Inflammatory Cytokines in hiPSC-Derived Endothelial Cells and Cardiomyocytes: Insights into ICI-Induced Myocarditis

Introduction: Inflammatory cytokines, particularly IFN-γ, are highly elevated in biopsies and the peripheral blood of patients with ICI-induced myocarditis (ICI-M). While the NLRP3 inflammasome has been implicated in ICI-M pathophysiology, its underlying mechanisms remain poorly understood.

Objective: This study investigates the transcriptional effects of inflammatory cytokines associated with ICI-M on endothelial cells (hiPSC-EC) and cardiomyocytes (hiPSC-CM) derived from a healthy individual’s hiPSC clone.

Method: The transcriptional profiles of both the hiPSC-derived endothelial cells (hiPSC-EC) and cardiomyocytes (hiPSC-CM) were analyzed following the IFN-γ treatment. Inflammatory responses, cell mortality, and apoptosis were assessed after stimulation with pro-inflammatory molecules, either through individual IFN-γ exposure or a combined cytokine cocktail (CCL5, GZMB, IL-1β, IL-2, IL-6, IFN-γ, and TNF-α), to characterize their effects on cellular function and viability better.

Results: Our findings reveal that hiPSC-ECs are highly sensitive to cytokine treatment, exhibiting significant mortality and marked transcriptomic changes in immunity- and inflammation-related pathways. In contrast, hiPSC-CMs show lower transcriptomic alterations, reduced mortality, and less apoptosis. In both cell types, cytokine treatment upregulates key components of the NLRP3 inflammasome pathway, including regulators (GBP5, GBP6, P2X7, NLRC5), a core component (AIM2), and an effector (GSDMD). Notably, cytokine treatment increases the GBP5 protein expression and CASP-1 cleavage in hiPSC-CMs, mirroring observations in endomyocardial biopsies from ICI-M patients.

Conclusion: This cellular model provides valuable insights into endocardial and microvascular dysfunctions in inflammatory conditions and their impact on cardiomyocytes. These findings establish a robust experimental model for investigating the response of hiPSC-derived cardiac cells to inflammatory cytokines implicated in immuno-mediated myocarditis. Moreover, they provide essential reference values for comparative studies using hiPSC clones derived from affected patients, thereby facilitating a deeper understanding of the disease mechanisms.