• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.238-246
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• 2001

Bone morphogenetic proteins(BMPs), members of the transforming growth factor $\beta$(TGF-$\beta$) superfamily were first identified as the factors that induce ectopic bone formation in vivo, when implanted into muscular tissue. Especially BMP-2 inhibits terminal differentiation of C2C12 myoblasts and converts them into osteoblast lineage cells. In the molecular mechanism of the signal transduction of TGF-$\beta$ and related factors, intracellular signaling proteins were identified as Smad. In previous study, it has been reported that Smad 1 and Smad 5, which belong to the R-Smad family mediate BMP signaling, were involved in the induction of osteoblast differentiation in C2C12 cells. To understnad the role of Smads involved in osteogenic transdifferentiation in C2C12 cell, in present study, after we stably transfected C2C12 cells with each. Smad(Smad 1,Smad 5) expression vector, cultured for 3 days and stained for alkaline phophatase activity. ALP activity positive cells appeared in the Smad 1, Smad 5 stably transfected cell even in the abscence of BMP. After transiently co-transfected C2C12 cells with each Smad expression vector and ALP promoter, it was examined that Smad 1 and Smad 5 expression vector had increased about 2 fold ALP promoter activity in the abscence of BMP. These result suggested that both Smad 1 and Smad 5 were involved in the intracellular BMP signals which induce osteoblast differentiation in C2C12 cells. The effect of BMP on C2C12 cells with Smad 1, Smad 5 transfected were studied by using northern blot analysis. the treatment of BMP upregulated ALP mRNA level in three groups, especially upregulation of ALP was larger in Smad 1, Smad 5 transfected cell than control group. Pretreatment with cycloheximide($10{\mu}g/ml$), a protein synthesis inhibitor resulted in blocking the ALP gene expression even in BMP(100ng/ml) treated cell. These results suggested that Smad increased the level of ALP mRNA via the synthesis of a certain transcriptional regulatory protein.