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 expressed in the biliary system and found in the bile.(A) Qualitative RT-PCR analysis reveals hepcidin mRNA expression in human hepatocellular carcinoma cell line (HepG2) as well as in human liver, gallbladder (GB) and common bile duct (CBD). The size of the amplified fragment was determined using a 100 bp DNA ladder (lane 1). Tissues from at least 15 individuals were examined to confirm the presented expression levels. (B) Real time RT-PCR was employed to quantify the mouse hepcidin mRNA levels. Results were compared to β-actin, which was used as an internal control and liver expression level was arbitrarily set as 1. Samples from at least five individual mice were examined. (C and D) Western blotting with two independent N-terminal antibodies (C,D) confirmed the presence of hepcidin peptide in HepG2 cell extracts (used as a positive control) as well as in human/mouse bile and mouse common bile duct (CBD).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3025980&req=5

pone-0016454-g001: Hepcidin is expressed in the biliary system and found in the bile.(A) Qualitative RT-PCR analysis reveals hepcidin mRNA expression in human hepatocellular carcinoma cell line (HepG2) as well as in human liver, gallbladder (GB) and common bile duct (CBD). The size of the amplified fragment was determined using a 100 bp DNA ladder (lane 1). Tissues from at least 15 individuals were examined to confirm the presented expression levels. (B) Real time RT-PCR was employed to quantify the mouse hepcidin mRNA levels. Results were compared to β-actin, which was used as an internal control and liver expression level was arbitrarily set as 1. Samples from at least five individual mice were examined. (C and D) Western blotting with two independent N-terminal antibodies (C,D) confirmed the presence of hepcidin peptide in HepG2 cell extracts (used as a positive control) as well as in human/mouse bile and mouse common bile duct (CBD).

Mentions: To test, whether hepcidin is present in the biliary system, total RNA was isolated from 15 individual patients. RT-PCR demonstrated hepcidin mRNA presence in both gallbladder and common bile duct (CBD). Liver tissues and HepG2 cell extracts were used as positive control and resulted in strong hepcidin amplification (Fig. 1A), while non-transcribed total mRNA did not reveal any signal thereby confirming the PCR specificity (not shown). Hepcidin 1 mRNA was also present in both mouse gallbladder and CBD with expression levels being liver>CBD>gallbladder (normalized values 1±0.32 vs. 0.26±0.12 vs. 0.02±0.02; Fig. 1B). Hepcidin peptide was observed in both the human and mouse bile as well as mouse CBD and gallbladder as shown by western blotting with three independent antibodies directed against N- and C-terminal part of hepcidin (Fig. 1C,D and not shown). The peptide levels were comparable to levels seen in total cell lysate from HepG2 cells.


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 expressed in the biliary system and found in the bile.(A) Qualitative RT-PCR analysis reveals hepcidin mRNA expression in human hepatocellular carcinoma cell line (HepG2) as well as in human liver, gallbladder (GB) and common bile duct (CBD). The size of the amplified fragment was determined using a 100 bp DNA ladder (lane 1). Tissues from at least 15 individuals were examined to confirm the presented expression levels. (B) Real time RT-PCR was employed to quantify the mouse hepcidin mRNA levels. Results were compared to β-actin, which was used as an internal control and liver expression level was arbitrarily set as 1. Samples from at least five individual mice were examined. (C and D) Western blotting with two independent N-terminal antibodies (C,D) confirmed the presence of hepcidin peptide in HepG2 cell extracts (used as a positive control) as well as in human/mouse bile and mouse common bile duct (CBD).
© Copyright Policy
Related In: Results  -  Collection

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

pone-0016454-g001: Hepcidin is expressed in the biliary system and found in the bile.(A) Qualitative RT-PCR analysis reveals hepcidin mRNA expression in human hepatocellular carcinoma cell line (HepG2) as well as in human liver, gallbladder (GB) and common bile duct (CBD). The size of the amplified fragment was determined using a 100 bp DNA ladder (lane 1). Tissues from at least 15 individuals were examined to confirm the presented expression levels. (B) Real time RT-PCR was employed to quantify the mouse hepcidin mRNA levels. Results were compared to β-actin, which was used as an internal control and liver expression level was arbitrarily set as 1. Samples from at least five individual mice were examined. (C and D) Western blotting with two independent N-terminal antibodies (C,D) confirmed the presence of hepcidin peptide in HepG2 cell extracts (used as a positive control) as well as in human/mouse bile and mouse common bile duct (CBD).
Mentions: To test, whether hepcidin is present in the biliary system, total RNA was isolated from 15 individual patients. RT-PCR demonstrated hepcidin mRNA presence in both gallbladder and common bile duct (CBD). Liver tissues and HepG2 cell extracts were used as positive control and resulted in strong hepcidin amplification (Fig. 1A), while non-transcribed total mRNA did not reveal any signal thereby confirming the PCR specificity (not shown). Hepcidin 1 mRNA was also present in both mouse gallbladder and CBD with expression levels being liver>CBD>gallbladder (normalized values 1±0.32 vs. 0.26±0.12 vs. 0.02±0.02; Fig. 1B). Hepcidin peptide was observed in both the human and mouse bile as well as mouse CBD and gallbladder as shown by western blotting with three independent antibodies directed against N- and C-terminal part of hepcidin (Fig. 1C,D and not shown). The peptide levels were comparable to levels seen in total cell lysate from HepG2 cells.

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