Food Function Division, National Food Research Institute, National Agriculture and Food Research Organization, Kannondai 2-1-12, Tsukuba, Ibaraki 305-8642, Japan.
In Vitro Cell Dev Biol Anim. 2010 Jan;46(1):36-44. doi: 10.1007/s11626-009-9239-9. Epub 2009 Sep 29.
Transforming growth factor-betas (TGF-betas), expressed in various tissues, play important roles in embryonic development and adult tissue homeostasis through their effects on cell proliferation, cell differentiation, cell death, and cell motility. However, expression of TGF-beta signaling components and their biological effect on taste epithelia has not been elucidated. We performed expression analysis of TGF-beta signaling components in taste epithelia and found that the TGF-beta3 mRNA was specifically expressed in taste buds. Type II TGF-betas receptor (TbetaR-II) mRNA was specifically expressed in the tongue epithelia including the taste epithelia. To elucidate the biological function of TGF-beta3 in taste epithelia, we performed proliferation assay with primary cultured taste epithelial cells. In the presence of TGF-beta3, percentage of BrdU-labeled cells decreased significantly, suggesting that the TGF-beta3 inhibited the proliferation of cultured taste epithelial cells through inhibiting cell-cycle entry into S phase. By quantitative reverse transcription-polymerase chain reaction assay, we found that the TGF-beta3 resulted in an increased level of expression of p15Ink4b and p21Cip1, suggesting that the TGF-beta3 inhibited the taste epithelial cell proliferation through inhibiting G1cyclin-Cdk complexes. Taken together, these results suggested that the TGF-beta3 may regulate taste epithelial cell homeostasis through controlling cell proliferation.
转化生长因子-β（TGF-βs）在各种组织中表达，通过对细胞增殖、细胞分化、细胞死亡和细胞迁移的影响，在胚胎发育和成人组织稳态中发挥重要作用。然而，TGF-β信号成分的表达及其对味觉上皮的生物学效应尚未阐明。我们对味觉上皮中的 TGF-β信号成分进行了表达分析，发现 TGF-β3 mRNA 特异性表达于味蕾。TGF-β 型受体 II（TbetaR-II）mRNA 特异性表达于包括味觉上皮在内的舌上皮中。为了阐明 TGF-β3 在味觉上皮中的生物学功能，我们用原代培养的味觉上皮细胞进行了增殖试验。在 TGF-β3 的存在下，BrdU 标记细胞的百分比显著降低，表明 TGF-β3 通过抑制细胞周期进入 S 期来抑制培养的味觉上皮细胞的增殖。通过定量逆转录聚合酶链反应试验，我们发现 TGF-β3 导致 p15Ink4b 和 p21Cip1 的表达水平升高，表明 TGF-β3 通过抑制 G1 周期蛋白-Cdk 复合物来抑制味觉上皮细胞的增殖。综上所述，这些结果表明 TGF-β3 可能通过控制细胞增殖来调节味觉上皮细胞的稳态。
