MIP-1α induces inflammatory responses by upregulating chemokine receptor 1/chemokine receptor 5 and activating c-Jun N-terminal kinase and mitogen-activated protein kinase signaling pathways in acute pancreatitis.

Objective We aimed to investigate the association of macrophage inflammatory protein (MIP)-1 alpha (CCL3) expression with the severity of acute pancreatitis (AP). Methods The patients with AP were selected and divided into mild AP (MAP), moderately severe AP (MSAP), and severe AP (SAP) groups according to the severity of AP. The pancreatic acinar cell line Ar42 j was treated with cerulein to induce in vitro cell AP model. The expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) and the activation of the c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (MAPK) signaling pathway in stimulated or transfected Ar42 j cells were detected. Results We detected that the upregulation of MIP-1 alpha was associated with the severity of AP. Patients with SAP showed the highest MIP-1 alpha contents, followed by MSAP, and, lastly, MAP. In cerulein-stimulated Ar42 j cells, the upregulation of MIP-1 alpha, CCR5, TNF-alpha, and IL-6 was time dependent. In addition, in human recombinant MIP-1 alpha treated Ar42 j cells, the upregulation of TNF-alpha and IL-6 was MIP-1 alpha-dose-dependent. In contrast, we detected the inhibition of TNF-alpha and IL-6 in MIP-1 alpha small interfering RNA (siRNA)-treated cells. Also, the activation of the JNK/p38 MAPK signaling pathway was induced and inhibited by human recombinant MIP-1 alpha and MIP-1 alpha siRNA, respectively. Conclusion These results suggested that MIP-1 alpha might be used as a biomarker for the prognosis of AP severity. The MIP-1 alpha-induced inflammatory responses in AP were mediated by TNF-alpha and IL-6, which were associated with the activation of the JNK/p38 MAPK signaling pathway.