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Hepcidin is an antibacterial, stress-inducible peptide of the biliary system.

Strnad P, Schwarz P, Rasenack MC, Kucukoglu O, Habib RI, Heuberger D, Ehehalt R, Müller MW, Stiehl A, Adler G, Kulaksiz H - PLoS ONE (2011)

Bottom Line: Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid.Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis.In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively).

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine I, University Hospital Ulm, Ulm, Germany.

ABSTRACT

Background/aims: Hepcidin (gene name HAMP), an IL-6-inducible acute phase peptide with antimicrobial properties, is the key negative regulator of iron metabolism. Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid. While the role of hepcidin in biliary system is unknown, a recent study demonstrated that conditional gp130-knockout mice display diminished hepcidin levels and increased rate of biliary infections.

Methods: Expression and localization of HAMP in biliary system was analyzed by real time RT-PCR, in-situ hybridization, immunostaining and -blotting, while prohepcidin levels in human bile were determined by ELISA.

Results: Hepcidin was detected in mouse/human gallbladder and bile duct epithelia. Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis. Hepcidin is also present in the bile and elevated prohepcidin levels were observed in bile of primary sclerosing cholangitis (PSC) patients with concurrent bacterial cholangitis compared to PSC subjects without bacterial infection (median values 22.3 vs. 8.9; p = 0.03). In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively). In vitro, hepcidin enhanced the antimicrobial capacity of human bile (p<0.05).

Conclusion: Hepcidin is a stress-inducible peptide of the biliary epithelia and a potential marker of biliary stress. In the bile, hepcidin may serve local functions such as protection from bacterial infections.

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Related in: MedlinePlus

Biliary hepcidin expression is stress-inducible.(A and B) Quantitative real-time RT-PCR analyses confirmed elevated hepcidin expression in the biliary cell lines Mz-Cha-1 (A) and RPMI-7451 (B) four hours after IL-6 stimulation (right bar; 13 ng/ml) compared to basal conditions (left bar). The graphs indicate the average values plus standard deviation of four independent experiments. (C) Quantitative real time RT-PCR analysis of hepcidin expression in normal gallbladder mucosa (used as a control) and in gallbladder mucosa from patients with acute cholecystitis (average of four samples each). Gallbladder inflammation resulted in ∼7 fold up-regulation of hepcidin mRNA levels. The hepcidin expression was compared to housekeeping gene beta-actin, which was used as an internal control and the expression in non-treated cells/gallbladders was arbitrarily set as 1.
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pone-0016454-g005: Biliary hepcidin expression is stress-inducible.(A and B) Quantitative real-time RT-PCR analyses confirmed elevated hepcidin expression in the biliary cell lines Mz-Cha-1 (A) and RPMI-7451 (B) four hours after IL-6 stimulation (right bar; 13 ng/ml) compared to basal conditions (left bar). The graphs indicate the average values plus standard deviation of four independent experiments. (C) Quantitative real time RT-PCR analysis of hepcidin expression in normal gallbladder mucosa (used as a control) and in gallbladder mucosa from patients with acute cholecystitis (average of four samples each). Gallbladder inflammation resulted in ∼7 fold up-regulation of hepcidin mRNA levels. The hepcidin expression was compared to housekeeping gene beta-actin, which was used as an internal control and the expression in non-treated cells/gallbladders was arbitrarily set as 1.

Mentions: Given that hepcidin is known as an acute phase protein [24], we wondered whether this inflammation-inducible regulation also applies to biliary epithelia. To test that, we stimulated two commonly used cholangiocarcinoma cell lines RPMI-7451 [20] and Mz-ChA-1 [21] with IL-6, an established hepcidin inducer [24]. IL-6 resulted in significantly higher hepcidin mRNA levels in both cell lines although the extent of hepcidin induction differed (80% in RPMI-7451 vs. 700% in Mz-CHA-1 cells, respectively; p = 0.01 and p = 0.002; Fig. 5A,B). To study the hepcidin expression in the whole tissue context, we examined tissue samples from patients with and without acute cholecystitis. Of note, biliary hepcidin expression was elevated ∼7-times in patients with acute cholecystitis (Fig. 5C), in whom the presence of inflammation was confirmed histologically (not shown) when compared to the non-inflamed controls (p = 0.01).


Hepcidin is an antibacterial, stress-inducible peptide of the biliary system.

Strnad P, Schwarz P, Rasenack MC, Kucukoglu O, Habib RI, Heuberger D, Ehehalt R, Müller MW, Stiehl A, Adler G, Kulaksiz H - PLoS ONE (2011)

Biliary hepcidin expression is stress-inducible.(A and B) Quantitative real-time RT-PCR analyses confirmed elevated hepcidin expression in the biliary cell lines Mz-Cha-1 (A) and RPMI-7451 (B) four hours after IL-6 stimulation (right bar; 13 ng/ml) compared to basal conditions (left bar). The graphs indicate the average values plus standard deviation of four independent experiments. (C) Quantitative real time RT-PCR analysis of hepcidin expression in normal gallbladder mucosa (used as a control) and in gallbladder mucosa from patients with acute cholecystitis (average of four samples each). Gallbladder inflammation resulted in ∼7 fold up-regulation of hepcidin mRNA levels. The hepcidin expression was compared to housekeeping gene beta-actin, which was used as an internal control and the expression in non-treated cells/gallbladders was arbitrarily set as 1.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3025980&req=5

pone-0016454-g005: Biliary hepcidin expression is stress-inducible.(A and B) Quantitative real-time RT-PCR analyses confirmed elevated hepcidin expression in the biliary cell lines Mz-Cha-1 (A) and RPMI-7451 (B) four hours after IL-6 stimulation (right bar; 13 ng/ml) compared to basal conditions (left bar). The graphs indicate the average values plus standard deviation of four independent experiments. (C) Quantitative real time RT-PCR analysis of hepcidin expression in normal gallbladder mucosa (used as a control) and in gallbladder mucosa from patients with acute cholecystitis (average of four samples each). Gallbladder inflammation resulted in ∼7 fold up-regulation of hepcidin mRNA levels. The hepcidin expression was compared to housekeeping gene beta-actin, which was used as an internal control and the expression in non-treated cells/gallbladders was arbitrarily set as 1.
Mentions: Given that hepcidin is known as an acute phase protein [24], we wondered whether this inflammation-inducible regulation also applies to biliary epithelia. To test that, we stimulated two commonly used cholangiocarcinoma cell lines RPMI-7451 [20] and Mz-ChA-1 [21] with IL-6, an established hepcidin inducer [24]. IL-6 resulted in significantly higher hepcidin mRNA levels in both cell lines although the extent of hepcidin induction differed (80% in RPMI-7451 vs. 700% in Mz-CHA-1 cells, respectively; p = 0.01 and p = 0.002; Fig. 5A,B). To study the hepcidin expression in the whole tissue context, we examined tissue samples from patients with and without acute cholecystitis. Of note, biliary hepcidin expression was elevated ∼7-times in patients with acute cholecystitis (Fig. 5C), in whom the presence of inflammation was confirmed histologically (not shown) when compared to the non-inflamed controls (p = 0.01).

Bottom Line: Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid.Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis.In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively).

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine I, University Hospital Ulm, Ulm, Germany.

ABSTRACT

Background/aims: Hepcidin (gene name HAMP), an IL-6-inducible acute phase peptide with antimicrobial properties, is the key negative regulator of iron metabolism. Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid. While the role of hepcidin in biliary system is unknown, a recent study demonstrated that conditional gp130-knockout mice display diminished hepcidin levels and increased rate of biliary infections.

Methods: Expression and localization of HAMP in biliary system was analyzed by real time RT-PCR, in-situ hybridization, immunostaining and -blotting, while prohepcidin levels in human bile were determined by ELISA.

Results: Hepcidin was detected in mouse/human gallbladder and bile duct epithelia. Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis. Hepcidin is also present in the bile and elevated prohepcidin levels were observed in bile of primary sclerosing cholangitis (PSC) patients with concurrent bacterial cholangitis compared to PSC subjects without bacterial infection (median values 22.3 vs. 8.9; p = 0.03). In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively). In vitro, hepcidin enhanced the antimicrobial capacity of human bile (p<0.05).

Conclusion: Hepcidin is a stress-inducible peptide of the biliary epithelia and a potential marker of biliary stress. In the bile, hepcidin may serve local functions such as protection from bacterial infections.

Show MeSH
Related in: MedlinePlus