thus, resembles scar tissue. TGF-β1, MMP and TIMP play an essential role in remodeling extracellular matrix during scar formation. This study investigates the pathogenesis of IF with respect to the coordinated expression of factors involved in wound healing. Proliferative activity and expression of TGF-β1, MMP-1 and TIMP-1 were observed using immunohistochemistry in 88 cases of IF and 9 cases of normal oral mucosa(NOM). Proliferative activity and expression of TGF-β1 and TIMP-1 were increased in IF compared to NOM. MMP-1 expression was not significantly increased in IF. We propose that IF is caused by increased expression of TGF-β1 and an imbalance in expression of MMP-1 and TIMP-1.

본 연구는 체세포 복제란 이식우의 분만에 있어서 혈중 스테로이드호르몬, TGF-β1 농도와 분만지연의 상관 관계를 살펴보고자 실시하였다. 대조군으로는 인공수정(AI)을 통하여 임신한 암소(cow)들을 사용하였다(AI-R). 모든 AI-R들은 자연분만(n=5, 임신 284+-0.71일)을 하였다. 분만징후를 보이지 않는 체세포 복제란 이식우(n=5, SCNT-R)들은 분만 예정일보다 10일 정도 지난 임신 292일째에 제왕절개(Caesarean section, C-sec)를 실시하여 분만하였다. 혈액 및 태반 샘플을 분만 전.후에 채취하여 형태 및 중량 등을 측정하였다. 혈장호르몬인 Progesterone(P4)와 Estradiol-17β (E2) 농도는 방사선동위원소 면역 분석 시험(RIA) 방법을 이용하여 측정하였다. 혈장 및 태반분엽의 TGF-β1 농도는 ELISA 방법으로 측정하였다. SCNT-R에서 회수한 태반의 무게는 AI-R의 것과 비교하여 유의적으로 무거웠다(p<0.05). 분만 직전 SCNT-R들의 혈장 내 P4 농도는 AI-R들의 그것과 비교하여 유의하게 높았다(p<0.01). 하지만 SCNT-R들의 혈장 내 E2 농도는 AI-R과 비교하여 상대적으로 낮게 나타났다(p<0.01). 한편, 분만 전.후 SCNT-R들에서 혈장 또는 태반분엽의 TGF-β1 단백질 발현 수준은 AI-R들과 비교하여 각각 유의적으로 높은 수준을 유지하였다(p<0.01). 이상의 결과를 종합하여 보면, 분만 시 P4 및 E2의 이상 발현과 높은 수준의 혈장 및 태반 내 TGF-β1 단백질은 체세포 복제태아의 분만지연을 야기하는 중요한 요인들 중의 하나일 것이라 사료된다.

Extensive oral mucosa loss from a variety of conditions is associated with significant functional morbidity and mortality. Although it is known that keratinocytes are a rich source of wound healing promoting factors such as transforming growth factor-β1(TGF-β1), it is not clear whether differentiated keratinocytes in a multi-layer form release this multi-functional growth factor. This study examined the hypothesis that keratinocytes in mono- and multi-layer forms expressed different levels of TGF-β1. When NHOK reached confluency in serum free medium(KBM), in test medium containing 1.2 mM Ca++ KBM NHOK were allowed to form multi-layers and differentiate. The purpose of this study were to investigate the mRNA level of TGF-β1, FGF-2, and TIMP-1 by RT-PCR analysis and also to evaluate the expression of TGF-β1 and involucrin in keratinocytes at different times of the onset of differentiation. The numbers and sizes of these nodules were increased as the process of keratinocyte differentiation proceed. Cultured NHOK in preconfluency under KBM medium expressed a significantly higher level of TGF-β1 relative to those grown in multi-layer forms, while the level of TGF-β1 mRNA gradually reduced to its lowest level at 7 days of growing cells in test medium. Cultured NHOK in preconfluency of KBM medium expressed a lower level of FGF-2 and TIMP-1 relative to those grown in multi-layer forms, while the level of FGF-2 and TIMP-1 mRNA showed the highest level at 3 days at gradually reduced to its lowest level at 7 days of growing cells in test medium. As a differentiation marker for keratinocytes at different time points, the highest level of involucrin mRNA expression was found at the later stage of cell differentiation. It suggested that the expression of TGF-β1 mRNA be consistent with the expression of FGF-2 and TIMP-1 mRNA in NHOK grown in high calcium medium during the terminal differentiation. But differentiated NHOK expressing higher involucrin mRNA could show constant espression of TGF-β1, FGF-2 and TIMP-1.

Transforming growth factor-β (TGF-β) has been shown to have a positive effect on in vitro fertilization (IVF) and has been reported to stimulate meiosis at follicular level in variety of species. The study was designed to determine the expression patterns of TGF-β1, TGF-β receptors type Ⅰ, Ⅱ and Smads gene in bovine oocytes and embryos. TGF-β1 and their receptors were observed in the unfertilized oocytes. TGF-β1 and type Ⅱ receptor were not expressed at the blastocyst stage, however, only type I receptor was exclusively observed at the same stage. The blastocyst stage, in particular, showed high levels of mRNA expression patterns containing a TGF-β type Ⅰ receptor. The mRNA expression pattern of Smad 2 at all stages of embryonic development was similar in all respect with TGF-β1 type I receptor. On the contrary, Smad 3 and 4 were expressed with high and low level mRNA at the blastocyst stage. In conclusion, it is suggested that TGF-β signaling may be regarded as an important entity during the preimplantation embryo development.

Epithelium maintains homeostasis by the signaling balance of growth stimulation and inhibition. Recently, loss of growth inhibitory effects of transforming growth factor-β(TGF-β) on epithelial cells is regarded as a possible mechanism of cancer. Although the genomic mutation in type I and type Ⅱ receptors of TGF-β is considered one of important mechanism of these inactivation, there might be another inactivation mechanism because the mutation rate is relatively low and inhibitory effect is not associated with the mutation. The purpose of this study is evaluating controlling mechanism type Ⅱ receptor of TGF-β by detecting effects of TGF-β on growth inhibition and on expression of cell cycle regulatory protein p21CIP1. Eight cancer cell lines derived from oral squamous cell carcinoma(OSCC) were examined. There was no growth inhibition effects by TGF-β except YD-8 cells. YD-8 cells which showed growth inhibition expresses p21CIP1 by TGF-β whether refractory cell lines, YD-9, did not. All of the tumor cells express mRNA of type Ⅱ receptor by RT-PCR and northern blot analysis, especially on YD-8 and YD-17M. From these results, most of oral cancer cell lines might loose the growth inhibitory effects by TGF-β, and the growth inhibition on YD-8 cells was mediated by expression of p21CIP1.

Although it has been known that TGF-β1 acts as a crucial cofactor in osteoclast differentiation, its mode of action is still unclear. In the present study, we studied the effect of TGF-β1 on the differentiation of osteoclast depending on the developmental stages. Murine bone marrow cells were induced to differentiate into mature osteoclasts in the presence of receptor activator of NF-xβ ligand (RANKL) and macrophage colony stimulating factor (M-CSF). In the early stage of the differentiation TRAP(-) mononuclear precursor cells were obtained from nonadherent M-CSF dependent bone marrow cells, which further differentiated into mature osteoclasts. TGF-β1 stimulated osteoclast differentiation, which was stronger when cells were stimulated by TGF-β1 in the early stage than the later differentiation. TGF-β1 increased the expression of RANK and synergistically stimulated RANKL-induced activation of NF-xβ MAP kinase in TRAP(-) mononuclear precursor cells. These results suggest that activation of osteoclast differentiation by TGF-β1 may be ascribed to the both increased expression and activation of RANK in the osteoclast differentiation, especially in the early stage of differentiation.

The imbalance between epithelial cell growth and inhibitory factors may cause human epithelial cancer. The dysregulation of growth inhibitory effect of TGF-β1 has been recognized in a variety of carcinomas. This study aimed to investigate the expression of TGF-β1 type II receptors(TβR-II) in the carcinogenesis of oral squamous cell carcinoma(OSCC). Six cell lines established from OSCC in the department of Oral Pathology, Yonsei University College of Dentistry were used. DNA was extracted from harvested cells by phenol-chloroform method. Polymerase chain reaction (PCR) was done with each primer of exon 3, 4, 5, 6 of TβR-II gene. PCR products were inserted to cloning vector (pGEM-T easy vector) and then analyzed to automatic DNA sequencing analyzer. Reverse transcriptase-PCR (RT-PCR) was performed to confirm the mRNA expression of TβR-II gene. Western blotting was performed to detect the expression of the TβR-II protein. As results, a frameshift within a polyadenine region of exon 3 was found in YD-8 cell line. In YD-17 cell line, a missense mutation at codon 238 of exon 4 was found, suggesting the alteration of amino acid from asparagine to aspartic acid. TβR-II mRNA was detected in all cancer cell lines, but it was slightly decreased as compared to that of normal oral mucosal cells. In Western blotting, no TβR-Ⅱ protein was detected in all OSCC cell lines. These results suggested that the altered regulation of TGF-β1 function might play a role in the development of OSCC.