• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.3
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• pp.295-305
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• 2021

Purpose: Hepcidin levels have previously been reported to be correlated with liver damage. However, the association between hepcidin levels and liver fibrosis in children with fatty liver disease remains unclear. This study therefore aimed to investigate the pathophysiology of fibrosis in children with fatty liver disease and its association with hepcidin levels. Methods: This retrospective case series included 12 boys aged 6-17 years who were diagnosed with nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH) at the Tokyo Medical University Hospital. Sixteen liver biopsy samples from 12 subjects were analyzed. Serum hepcidin levels were assayed using enzyme-linked immunosorbent assay. Immunostaining for hepcidin was performed, and the samples were stratified by staining intensity. Results: Serum hepcidin levels were higher in pediatric NAFLD/NASH patients than in controls. Conversely, a significant inverse correlation was observed between hepcidin immunostaining and Brunt grade scores and between hepcidin scores and gamma-glutamyltranspeptidase, hyaluronic acid, and leukocyte levels. We observed inverse correlations with a high correlation coefficient of >0.4 between hepcidin immunostaining and aspartate aminotransferase, alanine aminotransferase, total bile acid, and platelet count. Conclusion: There was a significant inverse correlation between hepcidin immunoreactivity and fibrosis in pediatric NAFLD patients; however, serum hepcidin levels were significantly higher, suggesting that these patients experienced a reduction in the hepcidin-producing ability of the liver in response to iron levels, leading to subsequent fibrosis. Therefore, hepcidin levels can be used as markers to identify the progression of fibrosis in patients with NAFLD.

• Journal of Nutrition and Health
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• v.38 no.9
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• pp.750-755
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• 2005

Hepcidin, a peptide hormone synthesized mainly by the liver, has been implicated as a key regulator of iron homeostasis. Results from studies with experimental animal models suggested that hepcidin levels are related with body iron status, but little data is available in human subjects. This study was conducted to determine the relationship between serum pro-hepcidin levels, blood indexes of anemia, and dietary iron intake in female college students. Serum pro-hepcidin concentrations were measured by enzyme-linked immunosorbent assay in eighty-two women with $22.1\pm0.2$ years old. Dietary intake data were collected by using the 24-hour recall method for 3 days. Mean concentrations of serum pro-hepcidin were 85.1 ng/ml$\pm$6.1(s.d.) with the range of 13.6-295.7 ng/ml. The median value of serum pro-hepcidin in the study subjects was 70.3 ng/ml. Serum pro-hepcidin concentrations were positively correlated with hemoglobin concentrations (r=0.273, p=0.013), and also with hematocrit (r=0.291, p=0.008). To examine whether the level of dietary iron intake affects serum pro-hepcidin levels, study subjects were divided into two groups according to the amounts of daily iron intake. Serum pro-hepcidin concentrations were $22\%$ lower in groups with low iron intake (${\leq}10.1$ mg/day), compared to high-iron intake group (>10.1 mg/day) . In conclusion, these data, as in agreement with findings in mice, suggest that hepcidin plays an important role in regulating iron metabolism in the human body.

• Journal of fish pathology
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• v.24 no.3
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• pp.279-287
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• 2011

Transcriptional response patterns of mud loach (Misgurnus mizolepis; Cypriniformes) hepcidin, a potential ortholog to human hamp1, in response to experimental challenges with non-pathogenic and pathogenic bacterial species were analyzed based on the semi-quantitative reverse transcription-PCR assay. Mud loach hepcidin transcripts were much more preferentially induced by pathogenic bacterial species (Edwardsiella tarda and Vibrio anguillarum) causing apparent pathological symptoms than by non-pathogenic species (Escherichia coli and Bacillus thuringiensis) displaying neither clinical signs nor mortality. However in overall, the induced amounts of hepcidin transcripts were positively related with the number of bacterial cells delivered in both pathogenic and non-pathogenic bacterial species. Inducibility of hepcidin transcripts were variable among three tissues examined (liver, kidney and spleen) in which kidney and spleen were more responsive to the bacterial challenge than liver. Time course expression patterns of hepcidin mRNAs after challenge were different between groups challenged with pathogenic and non-pathogenic species, although the overall pattern of hepcidin expression was in accordance with that generally observed in battery genes appeared during early phase of inflammation. Fish challenged with E. coli (non-pathogenic) showed the significant induction of hepcidin transcripts within 24 hr post injection (hpi) but the level was rapidly declined to the basal level either at 48 or 96 hpi. On the other hand, hepcidin transcript levels in E. tarda (pathogenic)-challenged fish were continuously elevated until 48 hpi, then downregulated at 96 hpi, although the level at 96 hpi was still significantly higher than control level observed in non-challenged fish. This expression pattern was consistent in all the three tissues examined. Taken together, our data indicate that hepcidin is tightly in relation with pathological and/or inflammation status during bacterial challenge, consequently providing useful basis to extend knowledge on the host defensive roles of hepcidin under infectious conditions in bony fish.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.721-728
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• 2008

Hepcidin is a peptide hormone produced by the liver, of which secretion is closely related to iron status in the body. However, little is known about the molecular mechanism(s) by which this peptide regulates body iron homeostasis. The purpose of this study was to determine the effects of hepcidin treatment within the physiological concentration range on the expressions of two different iron transporter proteins-ferroportin (FPN) and divalent metal transporter 1 (DMT1). Differentiated Caco-2 intestinal cells and macrophage J774 cells were treated with either synthetic hepcidin or hepcidin-rich fraction separated from human urine at the concentration of 10 nM and 100 nM for 24 hours. Results show that hepcidin treatment in differentiated Caco-2 cells or in J774 cells did not change the level of either FPN mRNA or DMT1 mRNA. On the other hand, hepcidin treatment at the dose of 100 nM significantly decreased the FPN protein levels and DMT1 protein levels in differentiated Caco-2 cells. Similarly, urinary hepcidin treatment (10 nM & 100 nM) also significantly decreased the levels of FPN and DMT1 proteins in J774 macrophage cells. These results showed that hepcidin might play an important role in the regulation of iron homeostasis by lowering the protein levels of iron transporter FPN and DMT1 both in enterocytes and in macrophage cells.

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.31-42
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• 2011

Three novel hepcidin isoforms were isolated and characterized from the perciform fish species Oplegnathus fasciatus. These hepcidin isoforms (designated rbhepc5, rbhepc6 and rbhepc7) were found to share a conserved, tripartite gene structure and a considerable sequence homology one another. A comparison of their mature peptide sequences with those of other perciform hepcidin orthologs indicated that these three hepcidin isoforms as well as four other isoforms previously identified in this species, appear to belong to the HAMP2 group of hepcidin genes. Analysis of the 5'-upstream sequences showed that the proximal non-coding regions of rbhepc5~7 do not possess canonical TATA signals; instead, they harbor several binding motifs for transcription factors involved in immune modulation. Reverse transcriptase-PCR analysis demonstrated that the rbhepc5~7 are expressed predominantly in the liver, and that the transcription of rbhepc5~7 is rapidly induced in the liver, but not in other tissues, by experimental challenge with any of three different bacterial species. However, transcription of rbhepc6 appeared to be negligible under both basal and stimulated conditions, as judged by the redundancy count of randomly chosen reverse transcriptase-PCR clones.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.1
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• pp.42-49
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• 2019

Objective: Chronic obstructive pulmonary disease(COPD) is characterized by persistent airflow limitations associated with chronic inflammatory response due to noxious particles or gases in the lung. Iron deficiency is associated with chronic inflammation, such as COPD. The aim of this study was to evaluate the relationship among iron deficiency, iron homeostasis, and inflammation in retired miners with COPD. Methods: The serum levels of ferritin, soluble transferrin receptor(sTfR), and transferrin saturation(TSat) as biomarkers for iron deficiency and high-sensitivity C-reactive protein(hsCRP) as a biomarker for inflammation and hepcidin as a biomarker for iron homeostasis were measured in 93 male subjects. Iron deficiency was defined as any one or more of (1) sTfR>28.1 nmol/L, (2) TSat<16%, and (3) ferritin< $12{\mu}g/L$. Results: Iron deficiency was found 28% of the study subjects. Median levels of serum hsCRP was significantly increased related to airflow limitation of COPD(GOLD 1, $0.09{\mu}g/dL$ vs. GOLD 2, $0.17{\mu}g/dL$ vs. GOLD $3{\leq}$, $0.30{\mu}g/dL$, p=0.010), and was positively correlated with hepcidin(p=0.009). Mean level of serum hepcidin was lower in COPD subjects with iron deficiency(p=0.004) and serum levels of hepcidin was negatively correlated with %$FEV_1$ predicted(p=0.030). Conclusions: These results suggest that high serum levels of hepcidin are related to severe airflow limitation or inflammation and can decrease iron availability, regardless of iron status.

• IMMUNE NETWORK
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• v.11 no.5
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• pp.245-252
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• 2011

Antimicrobial peptides/proteins are ancient and naturally-occurring antibiotics in innate immune responses in a variety of organisms. Additionally, these peptides have been recognized as important signaling molecules in regulation of both innate and adaptive immunity. During mycobacterial infection, antimicrobial peptides including cathelicidin, defensin, and hepcidin have antimicrobial activities against mycobacteria, making them promising candidates for future drug development. Additionally, antimicrobial peptides act as immunomodulators in infectious and inflammatory conditions. Multiple crucial functions of cathelicidins in antimycobacterial immune defense have been characterized not only in terms of direct killing of mycobacteria but also as innate immune regulators, i.e., in secretion of cytokines and chemokines, and mediating autophagy activation. Defensin families are also important during mycobacterial infection and contribute to antimycobacterial defense and inhibition of mycobacterial growth both in vitro and in vivo. Hepcidin, although its role in mycobacterial infection has not yet been characterized, exerts antimycobacterial effects in activated macrophages. The present review focuses on recent efforts to elucidate the roles of host defense peptides in innate immunity to mycobacteria.

• Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.93-104
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• 2011

Two hepcidin paralogs (ojhamp1 and ojhamp2) were isolated and characterized from a euryhaline Javanese ricefish (Oryzias javanicus: Beloniformes). The ojhamp1 cDNA encoded 90 or 91 amino acids (aa) of a typical HAMP1 preproprotein. This preproprotein is believed to cleave and yield the 66 or 67 aa-proprotein, followed by the 26 aa-mature peptide, composed of 8 conserved cysteine residues and the QSHL amino terminal motif. The ojhamp2 cDNA encoded 89 aa of HAMP2 preproprotein, cleaved to yield a 65 aa proprotein, and subsequently the 25 aa-mature peptide. The mature OJHAMP1 possessed a cationic isoelectric point (pI), whereas OJHAMP2 had an anionic charge. At the genomic level, both ojhamp1 and ojhamp2 share a conserved tripartite structure (three exons interrupted by two introns) with other vertebrate hepcidin genes. However, the ojhamp1 was shown to exist as two distinct mRNA species, encoding 90 or 91 aa, due to alternative splicing at the junction site between intron I and exon II. Both ojhamp1 and ojhamp2 transcripts were detected in a wide range of tissue types with varying levels of basal expression, although the highest expression was observed in the liver for both isoforms. Transcriptional response to bacterial challenge using Edwardsiella tarda showed that ojhamp1 was moderately upregulated in the liver but remained unchanged in the kidney. However, the ojhamp2 was significantly suppressed in both the kidney and liver, suggesting a potential diversification between the two paralogs.

• Molecules and Cells
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• v.26 no.2
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• pp.140-145
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• 2008

Expression of olive flounder hepcidin I (HepI) fused with truncated OmpA signal peptides ($OmpASP_{tr}$) as directional signals does not produce soluble fusion proteins. However, by inserting amino acid segments (xxx) varying in pI and hydrophobicity/hydrophilicity into a leader sequence containing a truncated OmpASP ($OmpASP_{tr}$) and a factor Xa cleavage site (Xa) [$OmpASP_{tr}{\mid}(xxx){\mid}Xa$], we were able in some cases to express soluble recombinant HepI. Soluble expression of the recombinant protein strongly correlated with (xxx) insertions of high pI and hydrophilicity. Therefore, we modified the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ sequence by inserting Arg and Lys into (xxx) to increase the hydrophilicity of the signal peptide region. These modifications enhanced the expression of soluble recombinant HepI. Hydropathic profile analysis of the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ HepI fusion proteins revealed that the transmembrane-like domains derived from the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ sequence were larger than the internal positively charged domain native to HepI. It should therefore be possible to overcome the obstacle of internal positively charged domains to obtain soluble expression of recombinant proteins by monitoring the hydrophilicity and hydropathic profile of the signal peptide region using a computer program.

• Nutrition Research and Practice
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• v.9 no.6
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• pp.613-618
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• 2015

BACKGROUND/OBJECTIVES: Iron deficiency in early life is associated with developmental problems, which may persist until later in life. The question of whether iron repletion after developmental iron deficiency could restore iron homeostasis is not well characterized. In the present study, we investigated the changes of iron transporters after iron depletion during the gestational-neonatal period and iron repletion during the post-weaning period. MATERIALS/METHODS: Pregnant rats were provided iron-deficient (< 6 ppm Fe) or control (36 ppm Fe) diets from gestational day 2. At weaning, pups from iron-deficient dams were fed either iron-deficient (ID group) or control (IDR group) diets for 4 week. Pups from control dams were continued to be fed with the control diet throughout the study period (CON). RESULTS: Compared to the CON, ID rats had significantly lower hemoglobin and hematocrits in the blood and significantly lower tissue iron in the liver and spleen. Hepatic hepcidin and BMP6 mRNA levels were also strongly down-regulated in the ID group. Developmental iron deficiency significantly increased iron transporters divalent metal transporter 1 (DMT1) and ferroportin (FPN) in the duodenum, but decreased DMT1 in the liver. Dietary iron repletion restored the levels of hemoglobin and hematocrit to a normal range, but the tissue iron levels and hepatic hepcidin mRNA levels were significantly lower than those in the CON group. Both FPN and DMT1 protein levels in the liver and in the duodenum were not different between the IDR and the CON. By contrast, DMT1 in the spleen was significantly lower in the IDR, compared to the CON. The splenic FPN was also decreased in the IDR more than in the CON, although the difference did not reach statistical significance. CONCLUSIONS: Our findings demonstrate that iron transporter proteins in the duodenum, liver and spleen are differentially regulated during developmental iron deficiency. Also, post-weaning iron repletion efficiently restores iron transporters in the duodenum and the liver but not in the spleen, which suggests that early-life iron deficiency may cause long term abnormalities in iron recycling from the spleen.