Transcriptional regulation of CXC-ELR chemokines KC and MIP-2 in mouse pancreatic acini.
Neutrophils and their chemoattractants, the CXC-ELR chemokines keratinocyte cytokine (KC) and macrophage inflammatory protein-2 (MIP-2), play a critical role in pancreatitis. While acute pancreatitis is initiated in acinar cells, it is unclear if these are a source of CXC-ELR chemokines. KC and MIP-2 have NF-κB, activator protein-1 (AP-1) sites in their promoter regions. However, previous studies have shown increased basal and reduced caerulein-induced AP-1 activation in harvested pancreatic tissue in vitro, which limits interpreting the caerulein-induced response. Moreover, recent studies suggest that NF-κB silencing in acinar cells alone may not be sufficient to reduce inflammation in acute pancreatitis. Thus the aim of this study was to determine whether acinar cells are a source of KC and MIP-2 and to understand their transcriptional regulation. Primary overnight-cultured murine pancreatic acini were used after confirming their ability to replicate physiological and pathological acinar cell responses. Upstream signaling resulting in KC, MIP-2 upregulation was studied along with activation of the transcription factors NF-κB and AP-1. Cultured acini replicated critical responses to physiological and pathological caerulein concentrations. KC and MIP-2 mRNA levels increased in response to supramaximal but not to physiological caerulein doses. This upregulation was calcium and protein kinase C (PKC), but not cAMP, dependent. NF-κB inhibition completely prevented upregulation of KC but not MIP-2. Complete suppression of MIP-2 upregulation required dual inhibition of NF-κB and AP-1. Acinar cells are a likely source of KC and MIP-2 upregulation during pancreatitis. This upregulation is dependent on calcium and PKC. MIP-2 upregulation requires both NF-κB and AP-1 in these cells. Thus dual inhibition of NF-κB and AP-1 may be a more successful strategy to reduce inflammation in pancreatitis than targeting NF-κB alone.
Orlichenko
Lidiya S
LS
Dept. of Medicine, Univ. of Pittsburgh, PA 15213, USA. Singhv2@upmc.edu
Behari
Jaideep
J
Yeh
Tzu-Hsuan
TH
Liu
Shiguang
S
Stolz
Donna B
DB
Saluja
Ashok K
AK
Singh
Vijay P
VP
D000818:Animals; D002118:Calcium; D002108:Ceruletide / Q000378:metabolism / Q000494:pharmacology; D054360:Chemokine CXCL1 / Q000235:genetics / Q000378:metabolism*; D054426:Chemokine CXCL2 / Q000235:genetics / Q000378:metabolism*; D007249:Inflammation / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D015230:Prostaglandin D2 / Q000031:analogs & derivatives / Q000494:pharmacology; D011493:Protein Kinase C; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D046509:Tissue Culture Techniques; D018808:Transcription Factor AP-1 / Q000037:antagonists & inhibitors; D014158:Transcription, Genetic / Q000502:physiology*; D015854:Up-Regulation
D054360:Chemokine CXCL1; D054426:Chemokine CXCL2; C475895:Cxcl1 protein, mouse; C404915:Cxcl2 protein, mouse; D016328:NF-kappa B; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; C037112:9-deoxy-delta-9-prostaglandin D2; D002108:Ceruletide; D011493:Protein Kinase C; D015230:Prostaglandin D2; D002118:Calcium