Millions worldwide suffer from incurable lung diseases, and organ transplantation remains their only hope. However, there has been an absolute shortage of donor lungs and unmet needs for transplantable lung generation composed of tissue-specific mesenchyme, epithelium, and endothelium. Elucidation of lung precursor traits during development can lead to solving this issue. Using lineage-tracing mice, we discovered that gastrulating Foxa2 lineage+ Pdgfrα+ mesendoderm forms the competitive mesenchymal lung niche. We further evidenced that Foxa2+Pdgfrα+ mesendoderm is an evolutionarily-conserved niche during human iPSC-derived lung differentiation. The Fgfr2 gene depletion, specifically in the Foxa2 lineage, showed lung agenesis phenotype. Strikingly, donor iPSCs injection into those blastocysts complemented endodermal and mesodermal defective lung organ niches that efficiently led to the entire lung generation. Together, targeting Foxa2 lineage for lung generation is a novel paradigm, holding a grand promise for future human whole lung generation in large animals using human iPSCs.

Millions of people suffer from end-stage refractory diseases. The ideal treatment option for terminally ill patients is organ transplantation. However, donor organs are in absolute shortage, and sadly, most patients die while waiting for a donor organ. To date, no technology has achieved long-term sustainable patient-derived organ generation. In this regard, emerging technologies of chimeric human organ production via blastocyst complementation (BC) holds great promise. To take human organ generation via BC and transplantation to the next step, we reviewed current emerging organ generation technologies and the associated efficiency of chimera formation in human cells from the standpoint of developmental biology.

Pigs are evolutionarily more distant from humans than mice, but their physiological organs are closest to humans. The molecular program leading to a more than 1,000-fold increase in organ size in pigs and humans over that of mice across evolution has not been elucidated. We generated large-scale transcriptional landscapes throughout swine lung development. Our cross-species single-cell molecular atlas let us discover swine progenitor identities, stage-specific markers, and a core organ-size regulation program (COSRP), well-conserved in swine and humans but less so in mice. Across eight mammalian species, human COSRP promoters showed higher homologies to evolutionary-distant large animals, including pigs, than evolutionary-close small animals. Our study provides a molecular foundation during swine lung development that unveils animal size regulation conserved in the COSRP promoter, independent of genome-wide evolution. COSRP is a critical paradigm for studying thousands-fold changes in biological sizes in evolution, development, cancer, zoology, respirology, organoids, and biotechnology, particularly human-compatible organ generation.One Sentence SummaryA cross-species developmental molecular atlas identified the indicator of lung and animal size beyond evolution

Primary fibroblasts are a precious resource in the field of translational regenerative medicine. Dermal fibroblasts derived from human subject biopsies are being used as donor tissues for the derivation of patient-specific iPSC lines, which in turn are used for disease modeling, drug screening, tissue engineering, and cell transplantation. We developed a fast and simple protocol to grow dermal fibroblasts from skin biopsies. Using this protocol, we simply and firmly fix the biopsy piece on the surface of a tissue culture-treated plate and allow the fibroblasts to grow. This novel method eliminates any need for enzymatic digestion or mechanical dissociation of the biopsy piece. By using this newly developed protocol, we have successfully established around 100 fibroblast lines characterized by the expression of specific markers [Serpin H1 (Hsp-47), F-actin, and Vimentin]. Finally, we have used many of these fibroblast lines as donor tissues to successfully derive iPSC lines. We have developed a method that is simple, fast, convenient, efficient, and gentle on the cells to derive dermal fibroblasts from human skin biopsies.