Limits...
Effects of soluble epoxide hydrolase deficiency on acute pancreatitis in mice.

Bettaieb A, Chahed S, Tabet G, Yang J, Morisseau C, Griffey S, Hammock BD, Haj FG - PLoS ONE (2014)

Bottom Line: Acute pancreatitis (AP) is a frequent gastrointestinal disorder that causes significant morbidity, and its incidence has been progressively increasing.Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose inhibition in murine models has beneficial effects in inflammatory diseases, but its significance in AP remains unexplored.Conclusions -These findings demonstrate a novel role for sEH in the progression of cerulein- and arginine-induced AP.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition, University of California Davis, Davis, California, United States of America.

ABSTRACT

Background: Acute pancreatitis (AP) is a frequent gastrointestinal disorder that causes significant morbidity, and its incidence has been progressively increasing. AP starts as a local inflammation in the pancreas that often leads to systemic inflammatory response and complications. Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose inhibition in murine models has beneficial effects in inflammatory diseases, but its significance in AP remains unexplored.

Methodology/principal findings: To investigate whether sEH may have a causal role in AP we utilized Ephx2 knockout (KO) mice to determine the effects of sEH deficiency on cerulein- and arginine-induced AP. sEH expression increased at the protein and messenger RNA levels, as well as enzymatic activity in the early phase of cerulein- and arginine-induced AP in mice. In addition, amylase and lipase levels were lower in cerulein-treated Ephx2 KO mice compared with controls. Moreover, pancreatic mRNA and serum concentrations of the inflammatory cytokines IL-1B and IL-6 were lower in cerulein-treated Ephx2 KO mice compared with controls. Further, Ephx2 KO mice exhibited decreased cerulein- and arginine-induced NF-κB inflammatory response, MAPKs activation and decreased cell death. Conclusions -These findings demonstrate a novel role for sEH in the progression of cerulein- and arginine-induced AP.

Show MeSH

Related in: MedlinePlus

Increased sEH expression in acute pancreatitis.A) Total pancreas lysates of wild type mice without and with cerulein administration (14 h) immunoblotted for sEH, SHP1 and Tubulin as a loading control. Representative immunoblots are shown. Bar graph represents expression of sEH (normalized to Tubulin) and presented as means ± SEM (n = 12 per group) (AU: arbitrary units). B) sEH expression as assessed by quantitative real time PCR in pancreata of wild type mice without (n = 6) and with (n = 6) cerulein. For A and B, (**: P≤0.01) indicates significant difference between mice without and with cerulein administration. C) Total pancreas lysates of wild type mice without and with cerulein administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. Representative immunoblots are shown. D) Total pancreas lysates of wild type mice without and with arginine administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. E) Levels of EET and Diol in wild type and Ephx2 KO mice without (0) and with (48 and 72 h) arginine administration (n = 4 mice per group). (*: P≤0.05; **: P≤0.01) indicate significant difference between mice without and with arginine administration, and (#: P≤0.05; ##: P≤0.01) indicate significant difference between WT and KO mice.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4234494&req=5

pone-0113019-g001: Increased sEH expression in acute pancreatitis.A) Total pancreas lysates of wild type mice without and with cerulein administration (14 h) immunoblotted for sEH, SHP1 and Tubulin as a loading control. Representative immunoblots are shown. Bar graph represents expression of sEH (normalized to Tubulin) and presented as means ± SEM (n = 12 per group) (AU: arbitrary units). B) sEH expression as assessed by quantitative real time PCR in pancreata of wild type mice without (n = 6) and with (n = 6) cerulein. For A and B, (**: P≤0.01) indicates significant difference between mice without and with cerulein administration. C) Total pancreas lysates of wild type mice without and with cerulein administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. Representative immunoblots are shown. D) Total pancreas lysates of wild type mice without and with arginine administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. E) Levels of EET and Diol in wild type and Ephx2 KO mice without (0) and with (48 and 72 h) arginine administration (n = 4 mice per group). (*: P≤0.05; **: P≤0.01) indicate significant difference between mice without and with arginine administration, and (#: P≤0.05; ##: P≤0.01) indicate significant difference between WT and KO mice.

Mentions: Expression of pancreatic sEH was determined in wild type mice without and with cerulein-induced pancreatitis. AP was induced in mice with repetitive intraperitoneal injections of cerulein as detailed in Methods. Immunoblots of pancreatic lysates revealed significant increase in sEH expression upon cerulein administration (Fig. 1A). As control, expression of the SH2 domain-containing phosphatase SHP1 was determined since it is increased after cerulein administration [37], [38]. Indeed, pancreatic SHP1 expression increased in mice with cerulein administration (Fig. 1A). In addition, mRNA of the gene encoding sEH, as determined by real time RT-PCR, was increased in the pancreas upon cerulein administration (Fig. 1B). To evaluate the dynamic regulation of pancreatic sEH expression, sEH protein was determined at 3, 6, 9, 12 and 15 h after the initial injection of cerulein. sEH expression increased by 3 h of cerulein administration with progressive increase at later times (Fig. 1C). To ensure that these observations were not limited to a particular model of AP, pancreatic sEH protein expression was also determined in arginine-induced AP model. Similarly, pancreatic sEH expression significantly increased at 48 and 72 h after arginine injection (Fig. 1D). Further, to determine whether the observed increase in sEH expression is mirrored by an increase in enzyme activity, levels of EETs and DHETs were evaluated in pancreata of arginine-treated and untreated mice as detailed in Methods. As expected, KO mice exhibited elevated levels of EETs and decreased levels of DHETs (Fig. 1E). In addition, and consistent with elevated sEH expression during AP, levels of DHETs progressively increased with arginine administration in control mice. Together, these findings reveal increased sEH expression in two rodent models of AP and this was associated with increased sEH activity.


Effects of soluble epoxide hydrolase deficiency on acute pancreatitis in mice.

Bettaieb A, Chahed S, Tabet G, Yang J, Morisseau C, Griffey S, Hammock BD, Haj FG - PLoS ONE (2014)

Increased sEH expression in acute pancreatitis.A) Total pancreas lysates of wild type mice without and with cerulein administration (14 h) immunoblotted for sEH, SHP1 and Tubulin as a loading control. Representative immunoblots are shown. Bar graph represents expression of sEH (normalized to Tubulin) and presented as means ± SEM (n = 12 per group) (AU: arbitrary units). B) sEH expression as assessed by quantitative real time PCR in pancreata of wild type mice without (n = 6) and with (n = 6) cerulein. For A and B, (**: P≤0.01) indicates significant difference between mice without and with cerulein administration. C) Total pancreas lysates of wild type mice without and with cerulein administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. Representative immunoblots are shown. D) Total pancreas lysates of wild type mice without and with arginine administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. E) Levels of EET and Diol in wild type and Ephx2 KO mice without (0) and with (48 and 72 h) arginine administration (n = 4 mice per group). (*: P≤0.05; **: P≤0.01) indicate significant difference between mice without and with arginine administration, and (#: P≤0.05; ##: P≤0.01) indicate significant difference between WT and KO mice.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4234494&req=5

pone-0113019-g001: Increased sEH expression in acute pancreatitis.A) Total pancreas lysates of wild type mice without and with cerulein administration (14 h) immunoblotted for sEH, SHP1 and Tubulin as a loading control. Representative immunoblots are shown. Bar graph represents expression of sEH (normalized to Tubulin) and presented as means ± SEM (n = 12 per group) (AU: arbitrary units). B) sEH expression as assessed by quantitative real time PCR in pancreata of wild type mice without (n = 6) and with (n = 6) cerulein. For A and B, (**: P≤0.01) indicates significant difference between mice without and with cerulein administration. C) Total pancreas lysates of wild type mice without and with cerulein administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. Representative immunoblots are shown. D) Total pancreas lysates of wild type mice without and with arginine administration for the indicated times immunoblotted for sEH, SHP1 and Tubulin. E) Levels of EET and Diol in wild type and Ephx2 KO mice without (0) and with (48 and 72 h) arginine administration (n = 4 mice per group). (*: P≤0.05; **: P≤0.01) indicate significant difference between mice without and with arginine administration, and (#: P≤0.05; ##: P≤0.01) indicate significant difference between WT and KO mice.
Mentions: Expression of pancreatic sEH was determined in wild type mice without and with cerulein-induced pancreatitis. AP was induced in mice with repetitive intraperitoneal injections of cerulein as detailed in Methods. Immunoblots of pancreatic lysates revealed significant increase in sEH expression upon cerulein administration (Fig. 1A). As control, expression of the SH2 domain-containing phosphatase SHP1 was determined since it is increased after cerulein administration [37], [38]. Indeed, pancreatic SHP1 expression increased in mice with cerulein administration (Fig. 1A). In addition, mRNA of the gene encoding sEH, as determined by real time RT-PCR, was increased in the pancreas upon cerulein administration (Fig. 1B). To evaluate the dynamic regulation of pancreatic sEH expression, sEH protein was determined at 3, 6, 9, 12 and 15 h after the initial injection of cerulein. sEH expression increased by 3 h of cerulein administration with progressive increase at later times (Fig. 1C). To ensure that these observations were not limited to a particular model of AP, pancreatic sEH protein expression was also determined in arginine-induced AP model. Similarly, pancreatic sEH expression significantly increased at 48 and 72 h after arginine injection (Fig. 1D). Further, to determine whether the observed increase in sEH expression is mirrored by an increase in enzyme activity, levels of EETs and DHETs were evaluated in pancreata of arginine-treated and untreated mice as detailed in Methods. As expected, KO mice exhibited elevated levels of EETs and decreased levels of DHETs (Fig. 1E). In addition, and consistent with elevated sEH expression during AP, levels of DHETs progressively increased with arginine administration in control mice. Together, these findings reveal increased sEH expression in two rodent models of AP and this was associated with increased sEH activity.

Bottom Line: Acute pancreatitis (AP) is a frequent gastrointestinal disorder that causes significant morbidity, and its incidence has been progressively increasing.Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose inhibition in murine models has beneficial effects in inflammatory diseases, but its significance in AP remains unexplored.Conclusions -These findings demonstrate a novel role for sEH in the progression of cerulein- and arginine-induced AP.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition, University of California Davis, Davis, California, United States of America.

ABSTRACT

Background: Acute pancreatitis (AP) is a frequent gastrointestinal disorder that causes significant morbidity, and its incidence has been progressively increasing. AP starts as a local inflammation in the pancreas that often leads to systemic inflammatory response and complications. Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose inhibition in murine models has beneficial effects in inflammatory diseases, but its significance in AP remains unexplored.

Methodology/principal findings: To investigate whether sEH may have a causal role in AP we utilized Ephx2 knockout (KO) mice to determine the effects of sEH deficiency on cerulein- and arginine-induced AP. sEH expression increased at the protein and messenger RNA levels, as well as enzymatic activity in the early phase of cerulein- and arginine-induced AP in mice. In addition, amylase and lipase levels were lower in cerulein-treated Ephx2 KO mice compared with controls. Moreover, pancreatic mRNA and serum concentrations of the inflammatory cytokines IL-1B and IL-6 were lower in cerulein-treated Ephx2 KO mice compared with controls. Further, Ephx2 KO mice exhibited decreased cerulein- and arginine-induced NF-κB inflammatory response, MAPKs activation and decreased cell death. Conclusions -These findings demonstrate a novel role for sEH in the progression of cerulein- and arginine-induced AP.

Show MeSH
Related in: MedlinePlus