Calabrò A, Orsini B, Renzi D, Papi L, Surrenti E, Amorosi A, Herbst H, Milani S, Surrenti C
Department of Clinical Pathophysiology, University of Florence, Italy.
Histochem J. 1997 Oct;29(10):745-58. doi: 10.1023/a:1026469219190.
Increasing evidence indicates that epidermal growth factor and transforming growth factor-alpha are involved in the maintenance of oesophageal mucosal integrity. However, their cellular origin and the exact localization of their receptor in the oesophagus are still unclear. Therefore, we examined the expression of the two growth factors and their shared receptor in the normal human oesophagus at both mRNA and protein level, by immunohistochemistry, in situ hybridization and reverse transcription-polymerase chain reaction. In addition to being expressed in the proliferative compartment of the oesophageal epithelium, the receptor was found in a variety of cells, including smooth muscle cells, submucosal gland cells and the epithelium lining their ducts. Immunohistochemically, the pattern of distribution of epidermal growth factor paralleled that of its receptor. In situ hybridization demonstrated epidermal growth factor mRNA expression in the oesophageal epithelium and submucosal glands. Additionally, amplified transcripts of predicted size were detected by reverse transcription-polymerase chain reaction, thus confirming that authentic transcripts of the growth factor exist in the normal human oesophagus. Transforming growth factor-alpha mRNA and protein expression, while similar to that of epidermal growth factor, predominated in the more differentiated cell layers of the stratified squamous epithelium. These results demonstrate that the normal oesophagus can synthesize both growth factors. Moreover, the peculiar distribution of these peptides and the concomitant expression of their receptor in multiple cell types suggest that the two growth factors may exert diverse physiological functions in the oesophagus and participate in defence and reparative events following mucosal injury.
越来越多的证据表明，表皮生长因子和转化生长因子-α参与维持食管黏膜的完整性。然而，它们的细胞来源及其受体在食管中的具体定位仍不清楚。因此，我们通过免疫组织化学、原位杂交和逆转录-聚合酶链反应，在mRNA和蛋白质水平上检测了这两种生长因子及其共同受体在正常人类食管中的表达。除了在食管上皮的增殖区表达外，还在多种细胞中发现了该受体，包括平滑肌细胞、黏膜下腺细胞及其导管内衬的上皮细胞。免疫组织化学显示，表皮生长因子的分布模式与其受体的分布模式相似。原位杂交显示食管上皮和黏膜下腺中有表皮生长因子mRNA表达。此外，通过逆转录-聚合酶链反应检测到了预测大小的扩增转录本，从而证实了正常人类食管中存在该生长因子的真实转录本。转化生长因子-α的mRNA和蛋白质表达虽然与表皮生长因子相似，但在复层鳞状上皮的分化程度较高的细胞层中占主导地位。这些结果表明，正常食管能够合成这两种生长因子。此外，这些肽的特殊分布及其受体在多种细胞类型中的伴随表达表明，这两种生长因子可能在食管中发挥多种生理功能，并参与黏膜损伤后的防御和修复过程。
