Regulation of HSP60 and the role of MK2 in a new model of severe experimental pancreatitis.
The objective of this study was to investigate the role of MAPKAP kinase 2 (MK2) and heat shock protein (HSP) HSP60 in the pathogenesis of a new model of severe acute pancreatitis (AP). MK2 plays a significant role in the regulation of cytokines. It has been shown that induction and expression of several HSPs can protect against experimental pancreatitis. Interplay between both systems seems of high interest. Mice with a homozygous deletion of the MK2 gene were used. Severe AP was induced by combined intraperitoneal injections of cerulein with lipopolysaccharide (LPS). Severity of AP was assessed by biochemical markers and histology. The serum IL-6 and lung myeloperoxidase (MPO) levels were determined for assessing the extent of systemic inflammatory response. Expression of HSP25, HSP60, HSP70, and HSP90 was analyzed by Western blotting. Repeated injections of cerulein alone or cerulein plus LPS (Cer+LPS) resulted in local inflammatory responses in the pancreas and corresponding systemic inflammatory changes with pronounced severity in the Cer+LPS group. Compared with the C57Bl wild-type mice, the MK2-/- mice presented with significant milder pancreatitis and attenuated responses of serum amylase and trypsinogen activity. Furthermore, serum IL-6 was decreased as well as lung MPO activity. Injection of LPS alone displayed neither pancreatic inflammatory responses nor alterations of pancreatic enzyme activities but evidently elevated serum IL-6 levels and increased lung MPO activity. In contrast hereto, in the MK2-/- mice, these changes were much milder. Increased expression of HSP25 and HSP60 occurred after induction of AP. Especially, HSP60 was robustly elevated after Cer+LPS treatment, in both MK2-/- and wild-type mice. Thus the homozygous deletion of the MK2 gene ameliorates the severity of acute pancreatitis and accompanying systemic inflammatory reactions in a new model of severe acute pancreatitis. Our data support the hypothesis that MK2 participates in the multifactorial regulation of early inflammatory responses in AP, independently of the regulation of stress proteins like HSP25 and HSP60 and most likely due to its effect on cytokine regulation.
Li
Yong-Yu
YY
Department of Pathophysiology, School of Medicine, Tongji University, Shanghai, China.
Ochs
Stephanie
S
Gao
Zhi-Rong
ZR
Malo
Antje
A
Chen
Chang-Jie
CJ
Lv
Shuai
S
Gallmeier
Eike
E
Göke
Burkhard
B
Schäfer
Claus
C
D000818:Animals; D002108:Ceruletide / Q000008:administration & dosage / Q000494:pharmacology; D018834:Chaperonin 60 / Q000378:metabolism*; D017353:Gene Deletion; D006360:Heat-Shock Proteins / Q000378:metabolism; D015850:Interleukin-6 / Q000097:blood; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000494:pharmacology; D008168:Lung / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000378:metabolism; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D055292:Pancreatic alpha-Amylases / Q000378:metabolism; D010195:Pancreatitis / Q000139:chemically induced* / Q000378:metabolism* / Q000473:pathology; D009195:Peroxidase / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D014362:Trypsinogen / Q000378:metabolism; D000099190:MAP-Kinase-Activated Kinase 2
D002108:Ceruletide; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D015850:Interleukin-6; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D055292:Pancreatic alpha-Amylases; D009195:Peroxidase; D017346:Protein Serine-Threonine Kinases; D014362:Trypsinogen; D000099190:MAP-Kinase-Activated Kinase 2; C486113:Hsbp1 protein, mouse