The effect on dentin-pulp complex by FIP-2 isolated from rat wounded pulp

牙髓伤口愈合后的空腔准备可能涉及与空腔位置相关的反应性或修复性牙本质形成；然而，对分子反应知之甚少。我们的目的是分离和分析受损牙髓中诱导或抑制的基因，以确定参与牙髓损伤反应的分子过程。用cDNA减法从健康大鼠和损伤大鼠牙髓中分离出23个cDNA。通过文库筛选，我们鉴定出与人rFIP -2同源的大鼠14.7 k -相互作用蛋白(rFIP)-2A和B基因，参与调控细胞膜运输和细胞形态发生。RT-PCR分析显示损伤牙髓仅诱导rFIP-2B。原位杂交分析显示rFIP-2s在大鼠成年和胚胎组织中有独特的表达。rFIP-2A和B的转录是通过rFIP-2位点启动子的替代使用来调节的。将rFIP-2A或b - pacgfp1 -高尔基构建体转染正常大鼠肾细胞（NRK-52E）后，rFIP-2B定位于高尔基体中，而rFIP-2A则普遍存在于细胞质中，是一种缺失rFIP-2B n端250个氨基酸的截断蛋白。在大鼠髓质成纤维细胞（RPC-C2A）中，肿瘤坏死因子(TNF)-α显著诱导rFIP-2B，其诱导依赖于c-jun n -末端激酶（JNK）通路。rFIP-2B定位于细胞质中，并在细胞死亡刺激下转移到细胞核中。结果表明，rFIP-2的表达受替代启动子位点的调控，而rFIP-2B是TNF-a介导的关键分子，可能参与了牙髓炎症过程中细胞死亡的通路。

Pulpal wound healing followed by cavity preparation may involve reactionary or reparative dentinogenesis in relation to the cavity position; however, little is known about the molecular responses. We aimed to isolate and analyze genes induced or suppressed in the wounded pulp to identify molecular processes involved in the pulp responses to injury. Twenty-three cDNAs were isolated by cDNA subtraction between healthy and wounded pulp of rats. By library screening, we identified rat 14.7K-interacting protein (rFIP)-2A and B genes homologous to human FIP-2, being involved in regulating membrane trafficking and cellular morphogenesis. RT-PCR analysis showed induction for only rFIP-2B in the wounded pulp. In situ hybridization analysis revealed unique expression of rFIP-2s in adult and embryonic tissues of rats. Transcription of rFIP-2A and B was regulated by alternative use of promoters at rFIP-2 locus. When the rFIP-2A or B-pAcGFP1-Golgi construct was transfected into normal rat kidney (NRK-52E) cells, rFIP-2B was localized in Golgi of whereas rFIP-2A, which is a truncated protein lacking the N-terminal 250 amino acids of rFIP-2B, existed ubiquitously in the cytoplasm. In rat pulp fibroblasts (RPC-C2A) cells, rFIP-2B was significantly induced by tumor necrosis factor (TNF)-α, and the induction was dependent on c-jun N-terminal kinase (JNK) pathway. rFIP-2B was localized in the cytoplasm, and translocated into the nucleus by cell death stimuli. The results suggest that rFIP-2 expression is regulated by the alternative promoter site, and rFIP-2B is a crucial molecule mediated by TNF-a, may be involved in cell death pathway during pulp inflammation.