To evaluate differences in the lipidomics profile of a model of Duchenne cardiac organoids.

The absence of functional dystrophin in the muscle of patients with Duchenne muscular dystrophy (DMD) increases membrane fragility and alters lipid composition. However, the impact of dystrophin deficiency on lipid composition in human cardiac cells remains poorly understood.

Cardiac organoids were generated from a DMD cell line carrying a nonsense mutation (DMD c.4375_4379del, exon 45) using an established differentiation protocol and compared with organoids derived from a control line. Lipids were extracted from organoid samples using the Folch method. Six biological replicates were obtained for each condition. Lipid extracts were analyzed by HPLC-MRM analysis using  mass spectrometry (5500QTRAP-SCIEX), and statistical significance was determined using a false discovery rate threshold of <0.05.

We found significant upregulation in DMD compared to controls for several phosphatidylcholines (PC): PC(28:1), PC(32:0), PC(32:1), PC(34:0), PC(34:1), PC(34:2), PC(36:1), PC(36:2), and PC(36:3), as well as sphingomyelins (SM), including SM(34:1), SM(40:1), SM(40:2), SM(42:1), SM(42:2), and SM(42:3). Conversely, SM(38:1) and bis(monoacylglycero)phosphates (BMP), specifically BMP(16:1–18:1) and BMP(18:1–18:1), were significantly downregulated in DMD compared to controls. Moreover triglycerides and the ratio between saturated, monounsaturated and polyunsaturated fatty acid in phospholipids was is significantly altered.

Cardiac organoids replicate key in vivo features of DMD, such as increased levels of PC(34:1). The observed alterations in phosphatidylcholine species are consistent with enhanced membrane permeability and the altered saturated/unsaturated and monounsaturated/polyunsaturated ratio reflects sensitivity to oxidation and membrane order, while the reduction in BMP levels may indicate lysosomal dysfunction. Lowering of triglycerides level might suggest alterations in cell metabolism, with lower energetic efficiency. Together, these findings suggest that cardiac organoids not only recapitulate the lipid alterations characteristic of DMD but also provide a valuable human-based platform for investigating disease mechanisms and screening therapeutic compounds aimed at restoring membrane stability and lipid homeostasis.