• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.9-15
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• 2011

The functional cardiovascular system is comprised of distinct mesoderm-derived lineages including endothelial cells, vascular smooth muscle cells and other mesenchymal cells. Recent studies in the human embryonic stem cell differentiation model have provided evidence indicating that these cell lineages are developed from the common progenitors such as hemangioblasts and cardiovascular progenitor cells. Also, the studies have suggested that these progenitors have a common primordial progenitor, which expresses KDR (human Flk-1, also known as VEGFR2, CD309). We demonstrate here that sustained activation of BMP4 (bone morphogenetic protein 4) in hESC line, CHA15 hESC results in $KDR^+$ mesoderm specific differentiation. To determine whether the $KDR^+$ population derived from hESCs enhances potential to differentiate along multipotential mesodermal lineages than undifferentiated hESCs, we analyzed the development of the mesodermal cell types in human embryonic stem cell differentiation cultures. In embryoid body (EB) differentiation culture conditions, we identified an increased expression of $KDR^+$ population from BMP4-stimulated hESC-derived EBs. After induction with additional growth factors, the $KDR^+$ population sorted from hESCs-derived EBs displays mesenchymal, endothelial and vascular smooth muscle potential in matrix-coated monolayer culture systems. The populations plated in monolayer cultures expressed increased levels of related markers and exhibit a stable/homologous phenotype in culture terms. In conclusion, we demonstrate that the $KDR^+$ population is stably isolated from CHA15 hESC-derived EBs using BMP4 and growth factors, and sorted $KDR^+$ population can be utilized to generate multipotential mesodermal progenitors in vitro, which can be further differentiated into cardiovascular specific cells.

• Journal of Chest Surgery
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• v.36 no.2
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• pp.86-90
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• 2003

Bulla is an air-filled space within the lung parenchyma resulting from deterioration of the alveolar tissue. Molecular mechanism of the formation of the bulla is not well described. Fibroblast growth factor(FGF)-7, bone morphogenetic protein(BMP) receptor, and transforming growth factor(TGF)-$\beta$ receptor are known to have a stimulatory or inhibitory role in the lung formation. We investigated to see if these growth factor or cytokine receptors are involved in the bulla formation by immunohistochemical staining of bullous lung tissues from patients with primary spontaneous pneumothorax. Material and Method: Bullous lung tissues were obtained from 31 patients with primary spontaneous pneumothorax, including 30 males and 1 female from 15 to 39 years old. The bullous tissues were obtained by video-thoracoscopic surgery and/or mini-thoracotomy and fixed in formalin. Blocks of the specimens were embedded with paraffin and cut into 5-6 ${\mu}{\textrm}{m}$ thick slices. The sections were deparaffinized and hydrated and then incubated with primary antibodies against FGF-7, BMP-RII, or TGF-RII. Result: Of the 31 patients, 24 were TGF-RII positive including 18 strong and 6 weak positives. Observation with high magnification showed that strong immunostaining was detected in the boundary region between bullous and normal lung tissues. In contrast, all of the sections were negative with FGF-7 or BMP-RII antibodies. Conclusion: These results suggest that overexpression of TGF- P RII may be involved in the formation of bulla, although further molecular studies are needed to find out more detailed molecular mechanisms.