Growth and differentiation of keratinocytes : Molecular and histological study

角质形成细胞的生长和分化：分子和组织学研究

• 批准号: 07807168
• 负责人: HARADA Hidemitsu
• 金额: $ 1.34万
• 依托单位: Kyushu Dental College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07807168/
• 关键词: Keratinocytes; bcl-2; bcl-XL; BAX; apoptosis; differentiation; 最終分化; differential display; テロメレース; 細胞分化; NGF-R

Oral keratinocytes originate from basal cells, differentiate during migration to the surface, and finally are shed. Apoptosis occurs at the end of differentiation, but the precise relationship between terminal differentiation and apoptosis is not clear. In the present study, The bcl-2 proto-oncogene is a known inhibitor of apoptosis ; in normal human stratified squamous epithelium its expression is restricted to the basal cell layr. Bcl-xL was expressed in the basal cell and spinous cell layrs, and Bax was expressed in the spinous cell and granular cell layrs. In cultured keratinocytes, Bcl-xL was expressed under conditions of 0.1 mM calcium (low Ca2+) but disappeared under conditions of 1.0 mM calcium (high Ca2+) ; the latter induces keratinocyte differentiation. Bax was not expressed in keratinocytes with low Ca2+ but was expressed in cells with high Ca2+. And finally keratinocytes with high Ca2+ underwent apoptosis, which was detected by the TUNEL method and by 180-bp DNA fragmentation. To investigate the functional role of bcl-2 protein in the process of differentiation of oral keratinocytes, bcl-2 expression vector was transfected into SCC-25 cells, which normally undergo squamous cell differentiation in vitro while expressing specific differentiation markers, e.g., keratin10/11 and involucrin. In bcl-2 transfected SCC-25 cells, the expression of these differentiation markers was markedly suppressed.The bcl-2 proto-oncogene may play a critical role in opposing the commitment to terminal differentiation and apoptosis of oral keratinocytes. These results suggest that the process of terminal differentiation in gingival epithelium is a pathway to apoptosis.

口腔角质形成细胞起源于基底细胞，在迁移到表面的过程中分化，最后脱落。细胞凋亡发生在分化末期，但终末分化和细胞凋亡之间的确切关系尚不清楚。在本研究中，bcl-2原癌基因是一种已知的凋亡抑制因子，在正常人复层鳞状上皮中，其表达仅限于基底细胞层。Bcl-xL表达于基底细胞层和棘细胞层，Bax表达于棘细胞层和颗粒细胞层。在培养的角质形成细胞中，Bcl-xL在0.1 mM钙（低Ca 2+）的条件下表达，但在1.0 mM钙（高Ca 2+）的条件下消失;后者诱导角质形成细胞分化。Bax在低钙角质形成细胞中不表达，但在高钙角质形成细胞中表达。用TUNEL法和180-bp DNA片段化法检测高Ca ~（2+）角质形成细胞凋亡。为了研究bcl-2蛋白在口腔角质形成细胞分化过程中的功能作用，将bcl-2表达载体转染到SCC-25细胞中，SCC-25细胞通常在体外经历鳞状细胞分化，同时表达特异性分化标志物，角蛋白10/11和外皮蛋白。在转染bcl-2基因的SCC-25细胞中，这些分化标志物的表达均受到明显抑制，bcl-2原癌基因可能在对抗口腔角朊细胞向终末分化和凋亡的过程中起重要作用。提示牙龈上皮细胞的终末分化过程是细胞凋亡的一条途径。

项目成果

Hidemitsu Harada, et al.: "Overexpression of bcl-2 protein inhibits terminal differentiation of oral keratinocytes in vitro." Journal of oral pathology & Medicine. 27. 11-18 (1998)

Hidemitsu Harada 等人：“bcl-2 蛋白的过度表达可抑制体外口腔角质形成细胞的终末分化。”

Hidemitsu Harada, Takeshi Mitsuyasu, Yuji Seta, Yuka Maruoka, Kuniaki Toyoshima, Shigeru Yasumoto: "Overexpression of bcl-2 protein inhibits terminal differentiation of oral keratinocytes in vitro." J.Oral Pathol.Med.27. 11-17 (1998)

Hidemitsu Harada、Takeshi Mitsuyasu、Yuji Seta、Yuka Maruoka、Kuniaki Toyoshima、Shigeru Yasumoto：“bcl-2 蛋白的过度表达在体外抑制口腔角质形成细胞的终末分化。”

Yuka Maruoka, Hidemitsu Harada et al.: "Keratinocytes become terminally differentiated in a process involving programmed cell death" Biochemical and Biophysical Research Communications. 238. 886-890 (1997)

Yuka Maruoka、Hidemitsu Harada 等人：“角质形成细胞在涉及程序性细胞死亡的过程中最终分化”生物化学和生物物理研究通讯。

Yuka Maruoka, Hidemitsu Harada, Takeshi Mitsuyasu, Yuji Seta, Hideo Kurokawa, Minoru Kajiyama, Kuniaki Toyoshima: "Keratinocytes become terminally differentiated in a process involving programd cell death." Biochem.Biophys.Res.Commun.238. 886-890 (1997)

Yuka Maruoka、Hidemitsu Harada、Takeshi Mitsuyasu、Yuji Seta、Hideo Kurokawa、Minoru Kajiyama、Kuniaki Toyoshima：“角质形成细胞在涉及程序性细胞死亡的过程中发生终末分化。”