Co-development of mesoderm and endoderm enables organotypic vascularization in lung and gut organoids.

The vasculature and mesenchyme exhibit distinct organ-specific characteristics adapted to local physiological needs, shaped by microenvironmental and cell-cell interactions from early development. To recapitulate this entire process, we co-differentiated mesoderm and endoderm within the same spheroid to vascularize lung and intestinal organoids from induced pluripotent stem cells (iPSCs). Bone morphogenetic protein (BMP) signaling fine-tuned the endoderm-to-mesoderm ratio, a critical step in generating appropriate proportions of endothelial and epithelial progenitors with tissue specificity. Single-cell RNA sequencing (scRNA-seq) revealed organ-specific gene signatures of endothelium and mesenchyme and identified key ligands driving endothelial specification. The endothelium exhibited tissue-specific barrier function, enhanced organoid maturation, cellular diversity, and alveolar formation on the engineered lung scaffold. Upon transplantation into mice, the organoid vasculature integrated with the host circulation while preserving organ specificity, further promoting organoid maturation. Leveraging these vascularized organoids, we uncovered abnormal endothelial-epithelial crosstalk in patients with forkhead box F1 (FOXF1) mutations. Multilineage organoids provide an advanced platform to study intricate cell-to-cell communications in human organogenesis and disease.