Reversal of Surfactant Protein B Deficiency in Patient Specific Human Induced Pluripotent Stem Cell Derived Lung Organoids by Gene Therapy

Surfactant protein B (SFTPB) deficiency is a fatal disease affecting newborn infants. Surfactant is produced by alveolar type II cells which can be differentiated in vitro from patient specific induced pluripotent stem cell (iPSC)-derived lung organoids. Here we show the differentiation of patient specific iPSCs derived from a patient with SFTPB deficiency into lung organoids with mesenchymal and epithelial cell populations from both the proximal and distal portions of the human lung. We alter the deficiency by infecting the SFTPB deficient iPSCs with a lentivirus carrying the wild type SFTPB gene. After differentiating the mutant and corrected cells into lung organoids, we show expression of SFTPB mRNA during endodermal and organoid differentiation but the protein product only after organoid differentiation. We also show the presence of normal lamellar bodies and the secretion of surfactant into the cell culture medium in the organoids of lentiviral infected cells. These findings suggest that a lethal lung disease can be targeted and corrected in a human lung organoid model in vitro

Hypoxia-inducible factor-1 stimulates postnatal lung development but does not prevent o2-induced alveolar injury

This study investigated whether hypoxia-inducible factor (HIF)-1 influences postnatal vascularization and alveologenesis in mice and whether stable (constitutive-active) HIF could prevent hyperoxia-induced lung injury. We assessed postnatal vessel and alveolar formation in transgenic mice, expressing a stable, constitutive-active, HIF1a-subunit (HIF-1aDODD) in the distal lung epithelium. In addition,we compared lung function, histology, and morphometry of neonatal transgenic and wild-type mice subjected to hyperoxia. We found that postnatal lungs of HIF-1aDODDmice had a greater peripheral vessel density and displayed advanced alveolarization compared with control lungs. Stable HIF-1a expression was associated with increased postnatal expression of angiogenic factors, including vascular endothelial growth factor, angiopoietins 1 and 2, Tie2, and Ephrin B2 and B4. Hyperoxiaexposed neonatal HIF-1aDODD mice exhibited worse lung function but had similar histological and surfactant abnormalities compared with hyperoxia-exposed wild-type controls. In conclusion, expression of constitutive-active HIF-1a in the lung epithelium was associated with increased postnatal vessel growth via up-regulation of angiogenic factors. The increase in postnatal vasculature was accompanied by enhanced alveolar formation. However, stable HIF-1a expression in the distal lung did not prevent hyperoxia-induced lung injury in neonates but instead worsened lung function