Functional role of bone morphogenetic protein-4 in isolated canine parietal cells
Functional role of bone morphogenetic protein-4 in isolated canine parietal cells
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DOI：
10.1152/ajpgi.00194.2006
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发表时间：
2007-09-01
影响因子：
4.5
通讯作者：
Todisco, Andrea
中科院分区：
文献类型：
--
作者：
Nitsche, Hildegard;Ramamoorthy, Saravanan;Todisco, Andrea
骨形态发生蛋白(BMP)-4是细胞生长和分化的重要调节因子。BMP-4在胃粘膜的表达已被证实。我们报道了用EGF孵育犬顶壁细胞72小时，通过mapk依赖机制诱导顶壁细胞形态转化和抑制h +/K+- atp酶基因表达。我们探讨了BMP-4在壁细胞成熟和分化中的作用。此外，我们还研究了BMP-4是否调节上皮细胞中EGF的作用。采用Northern blots和定量RT-PCR检测H+/K+- atp酶基因表达。通过测定[C-14]氨基吡啶的吸收来评估产酸。采用抗叶caspase 3抗体的Western blots和碘化丙啶染色的碎片细胞核数量来定量壁细胞凋亡。用抗磷酸化MAPK抗体和抗磷酸化Smad1抗体进行Western blots检测MAPK活化和Smad1磷酸化。用抗h +/K+- atp酶α -亚单位抗体对细胞进行免疫组化染色，观察细胞壁细胞形态。BMP-4刺激Smad1磷酸化，诱导H+/K+- atp酶基因表达。BMP-4减弱了EGF介导的H+/K+- atp酶基因表达抑制，阻断了EGF诱导的壁细胞形态转化和MAPK激活。BMP-4增强组胺刺激[14C]氨基吡啶摄取的细胞孵育。BMP-4对壁细胞凋亡无影响，而tgf - β刺激caspase-3活化和核断裂。总之，BMP-4促进了分化的壁细胞表型的诱导和维持。这些发现可能为更好地理解胃上皮细胞生长和分化的调控机制提供新的线索。
Bone morphogenetic protein ( BMP)-4 is an important regulator of cellular growth and differentiation. Expression of BMP-4 has been documented in the gastric mucosa. We reported that incubation of canine parietal cells with EGF for 72 h induced both parietal cell morphological transformation and inhibition of H+/K+-ATPase gene expression through MAPK-dependent mechanisms. We explored the role of BMP-4 in parietal cell maturation and differentiation. Moreover, we investigated if BMP-4 modulates the actions of EGF in parietal cells. H+/K+-ATPase gene expression was examined by Northern blots and quantitative RT-PCR. Acid production was assessed by measuring the uptake of [ C-14] aminopyrine. Parietal cell apoptosis was quantitated by Western blots with anticleaved caspase 3 antibodies and by counting the numbers of fragmented, propidium iodide-stained nuclei. MAPK activation and Smad1 phosphorylation were measured by Western blots with antiphospho-MAPK and anti-phospho-Smad1 antibodies. Parietal cell morphology was examined by immunohistochemical staining of cells with anti-H+/K+-ATPase alpha-subunit antibodies. BMP-4 stimulated Smad1 phosphorylation and induced H+/K+-ATPase gene expression. BMP-4 attenuated EGF-mediated inhibition of H+/K+-ATPase gene expression and blocked EGF induction of both parietal cell morphological transformation and MAPK activation. Incubation of cells with BMP-4 enhanced histamine-stimulated [ 14C] aminopyrine uptake. BMP-4 had no effect on parietal cell apoptosis, whereas TGF-beta stimulated caspase-3 activation and nuclear fragmentation. In conclusion, BMP-4 promotes the induction and maintenance of a differentiated parietal cell phenotype. These findings may provide new clues for a better understanding of the mechanisms that regulate gastric epithelial cell growth and differentiation.