Role of Sp1 and NCX1 in the development of acute pancreatitis induced by caerulein

Abstract

Objective To explore the pathogenic roles of Sp1/NCX1 pathway in acute pancreatitis (AP) induced by caerulein. Methods Pancreatic acinar AR42J cells were stimulated with caerulein to establish a cell model of AP. CCK8 assay was used to evaluate the cell proliferation at 0, 24, 48 and 72 h after caerulein treatment, and the expression of LC3Ⅱ/LC3Ⅰ, the classic autophagy markers, were detected using Western blotting at 3, 6, 12, and 24 h after the treatment. qRT-PCR and Western blotting were used to detect the cellular expression of Sp1 at both the mRNA and protein levels at 1, 3, 6, 12, and 24 h. In a rat model of caerulein-induced AP, immunohistochemistry was used to observe the expression of Sp1 in the pancreas. The effect of Mithramycin A, an inhibitor of Sp1, on the expression of NCX1 protein in AR42J cells was tested using Western blotting. Results Caerulein significantly inhibited the proliferation and promoted the ratio of LC3Ⅱ/LC3Ⅰ in AR42J cells. Caerulein also significantly enhanced the mRNA and protein levels of Sp1 in AR42J cells (P < 0.05). Immunohistochemical staining showed that intraperitoneal injection of cearulein obviously up-regulated the expression level of Sp1 protein in the pancreas of rats. In AR42J cells, inhibition of Sp1 expression with Mithramycin A significantly suppressed the expression of NCX1 protein. Conclusion Sp1 plays a facilitating role in the development of caerulein-induced AP by up-regulating the expression of NCX1.

Keywords

• transcription factor sp1
• sodium-calcium exchanger-1
• acute pancreatitis