Limits...
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.

Show MeSH

Related in: MedlinePlus

Hepcidin is preferentially found in the apical membrane domain of the gallbladder epithelial cells.Cellular localization of hepcidin in human gallbladder was visualized by immunohistochemical staining of paraffin sections with diaminobenzidine with (e–f) or without (a–d) ammonium-nickel sulphate enhancement. The staining revealed that, in some cells, immunoreactivity for hepcidin is evenly distributed throughout the cytoplasm of epithelial cells (e,f), while in different gallbladder cholangiocytes, the epitope is enriched at the apical domain of gallbladder epithelia (c). Similar results were observed with two different C-terminal (a,c) and one N-terminal prohepcidin antibody (e,f). Of note, the presented staining is specific, since it is completely blocked by pre-incubation of the antibodies with their respective immunogenic peptides (b,d). Scale bars 50 µm (a,b,d); 30 µm (c); 100 µm (e); 50 µm (f).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3025980&req=5

pone-0016454-g004: Hepcidin is preferentially found in the apical membrane domain of the gallbladder epithelial cells.Cellular localization of hepcidin in human gallbladder was visualized by immunohistochemical staining of paraffin sections with diaminobenzidine with (e–f) or without (a–d) ammonium-nickel sulphate enhancement. The staining revealed that, in some cells, immunoreactivity for hepcidin is evenly distributed throughout the cytoplasm of epithelial cells (e,f), while in different gallbladder cholangiocytes, the epitope is enriched at the apical domain of gallbladder epithelia (c). Similar results were observed with two different C-terminal (a,c) and one N-terminal prohepcidin antibody (e,f). Of note, the presented staining is specific, since it is completely blocked by pre-incubation of the antibodies with their respective immunogenic peptides (b,d). Scale bars 50 µm (a,b,d); 30 µm (c); 100 µm (e); 50 µm (f).

Mentions: To determine the site of hepcidin expression, we used in-situ hybridization, which located hepcidin mRNA to gallbladder epithelial cells in humans (Fig. 2a,c), whereas no immunoreactivity was seen in the subepithelial or muscular layers. No signal was obtained with the sense probes (Fig. 2b,d) thereby confirming the specificity of the staining. Immunofluorescence and immunohistochemistry confirmed the data, both showing a strong hepcidin fluorescence in the cytoplasm of non-diseased human gallbladder epithelial cells (Fig. 3,4) as well as in guinea pig gallbladder epithelia (Fig. S1,S2). In some gallbladder cholangiocytes, hepcidin was evenly distributed throughout the cytoplasm whereas it was concentrated to the apical domain in others (Fig. 4). The presented staining was specific since it was completely blocked by pre-incubation of the antibodies with their respective peptide used for the immunization (Fig. 4b,d).


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)

Hepcidin is preferentially found in the apical membrane domain of the gallbladder epithelial cells.Cellular localization of hepcidin in human gallbladder was visualized by immunohistochemical staining of paraffin sections with diaminobenzidine with (e–f) or without (a–d) ammonium-nickel sulphate enhancement. The staining revealed that, in some cells, immunoreactivity for hepcidin is evenly distributed throughout the cytoplasm of epithelial cells (e,f), while in different gallbladder cholangiocytes, the epitope is enriched at the apical domain of gallbladder epithelia (c). Similar results were observed with two different C-terminal (a,c) and one N-terminal prohepcidin antibody (e,f). Of note, the presented staining is specific, since it is completely blocked by pre-incubation of the antibodies with their respective immunogenic peptides (b,d). Scale bars 50 µm (a,b,d); 30 µm (c); 100 µm (e); 50 µm (f).
© Copyright Policy
Related In: Results  -  Collection

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

pone-0016454-g004: Hepcidin is preferentially found in the apical membrane domain of the gallbladder epithelial cells.Cellular localization of hepcidin in human gallbladder was visualized by immunohistochemical staining of paraffin sections with diaminobenzidine with (e–f) or without (a–d) ammonium-nickel sulphate enhancement. The staining revealed that, in some cells, immunoreactivity for hepcidin is evenly distributed throughout the cytoplasm of epithelial cells (e,f), while in different gallbladder cholangiocytes, the epitope is enriched at the apical domain of gallbladder epithelia (c). Similar results were observed with two different C-terminal (a,c) and one N-terminal prohepcidin antibody (e,f). Of note, the presented staining is specific, since it is completely blocked by pre-incubation of the antibodies with their respective immunogenic peptides (b,d). Scale bars 50 µm (a,b,d); 30 µm (c); 100 µm (e); 50 µm (f).
Mentions: To determine the site of hepcidin expression, we used in-situ hybridization, which located hepcidin mRNA to gallbladder epithelial cells in humans (Fig. 2a,c), whereas no immunoreactivity was seen in the subepithelial or muscular layers. No signal was obtained with the sense probes (Fig. 2b,d) thereby confirming the specificity of the staining. Immunofluorescence and immunohistochemistry confirmed the data, both showing a strong hepcidin fluorescence in the cytoplasm of non-diseased human gallbladder epithelial cells (Fig. 3,4) as well as in guinea pig gallbladder epithelia (Fig. S1,S2). In some gallbladder cholangiocytes, hepcidin was evenly distributed throughout the cytoplasm whereas it was concentrated to the apical domain in others (Fig. 4). The presented staining was specific since it was completely blocked by pre-incubation of the antibodies with their respective peptide used for the immunization (Fig. 4b,d).

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