• 한국어병학회지
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• 제24권3호
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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.

• Fisheries and Aquatic Sciences
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• 제14권1호
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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.

• 한국식품영양과학회지
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• 제37권6호
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• pp.721-728
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• 2008

본 연구에서는 소장세포(Caco-2)와 대식세포(J774)를 이용하여 FPN과 DMT1의 유전자 발현에 hepcidin 펩타이드 호르몬이 미치는 영향을 알아보기 위하여 수행되었으며 그 결과를 요약하면 다음과 같다. Caco-2 세포에서 FPN과 DMT1의 mRNA 및 단백질 수준은 분화 진행에 따라 비례하여 증가하였으며, 특히 DMT1 단백질은 분화 초기에는 거의 발현되지 않다가 분화 7일째에 비로소 발현되기 시작한 후 급격히 증가하여 분화 17일째에는 7일째에 비해 단백질 수준이 10배 이상 크게 증가되었다. 분화된 Caco-2 세포에서 소변 hepcidin과 합성 hepcidin을 100 nM 농도로 24시간 동안 처리하였을 때, FPN 단백질 수준이 대조군에 비해 각각 60%와 70% 수준으로 유의하게 감소하였다. DMT1 단백질의 경우, 소변 hepcidin 100 nM 농도에서만 대조군의 55% 수준으로 유의하게 감소되었다. J774 세포에 소변 hepcidin 혹은 합성 hepcidin을 24시간 처리한 결과, 10 nM과 100 nM 농도에서 모두 대조군에 비해 FPN 단백질 수준이 유의적으로 감소하는 것으로 나타났으며, DMT1 단백질 수준도 소변 hepcidin 10 nM과 100 nM 처리에 의해 각각 대조군의 40%와 37% 수준으로 유의하게 감소하였다. 분화된 Caco-2 세포와 J774 세포에서 10 nM 혹은 100 nM 농도의 hepcidin 처리 시 DMT1 mRNA와 FPN mRNA 수준에는 영향을 미치지 않는 것으로 나타났으며, 이로 볼 때 hepcidin은 전사과정의 조절보다는 DMT1과 FPN 단백질로의 번역과정을 억제하거나 분해 속도를 촉진함으로써 이들 단백질의 수준을 낮추는 것으로 보인다. 이상의 결과는, hepcidin 펩타이드 호르몬이 DMT1 단백질과 FPN 단백질의 수준을 억제함으로써 체내 철분 대사 조절에 중요하게 관여함을 나타낸다. 특히 소장세포와 대식세포에 동시에 작용함으로써, 소장에서의 철분 흡수와 대식세포에서의 철분 방출을 효율적으로 억제하는 조절 인자로 작용할 수 있음을 제시한다. 앞으로 hepcidin의 생성 및 분비를 조절하는 요인에 대한 연구와 hepcidin이 실제 세포 내외로의 철분의 수송이 미치는 영향에 대한 기능적 연구가 계속적으로 이루어져야 할 것으로 사료된다.

• Fisheries and Aquatic Sciences
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• 제14권2호
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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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• 제26권2호
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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.

• 한국환경성돌연변이발암원학회지
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• 제25권4호
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• pp.134-142
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• 2005

Liver cancer is a leading cause of tumor-related mortality, Diethylnitrosamine (DEN) is one of the most extensively studied hepatic carcinogens to date. In this study, the mRNA expression profile in DEN-induced liver tumors in mice was analyzed using DNA microarrays. We report increased expression of genes that participate in hypoxia response, including metallothionein 1 (Mt1), metallothionein 2 (Mt2), fatty acid synthase (Fasn), transferrin (Trf), adipose differentiation-related Protein (AdfP) and ceruloplasmin (CP), as well as those involved in predisposition and development of cancers, such as cytochrome P450 2A5 (Cyp2a5), alpha 2-HS-glycoprotein (Ahsg) and Jun-B oncogene (Junb). The hepatic iron regulatory peptide, hepcidin (Hampl), was downregulated in DEN-stimulated liver tumors. Expression of tumor suppressor genes, such as tripartite motif protein 13 (Trim13), was decreased under these conditions. The data collectively indicate that DEN-induced tumor development can be exploited as a possible model for liver cancer, since this process involves various genes with important functions in hepatic carcinogenesis.

• Journal of Sport and Applied Science
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• 제6권4호
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• pp.11-23
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• 2022

New insights into the aetiology of anaemia in athletes have been discovered in recent years. From hemodilution and redistribution, which are thought to commit to so-called "sports anaemia," to iron deficiency triggered by higher requirements, dietary requirements, decreased uptake, enhanced losses, hemolysis, and sequester, to genetic factors of different types of anaemia (some related to sport), anaemia in athletes necessitates a careful and multisystem methodology. Dietary factors that hinder iron absorption and enhance iron bioavailability (e.g., phytate, polyphenols) should be considered. Celiac disease, which is more common in female athletes, may be the consequence of an iron deficiency anaemia that is unidentified. Sweating, hematuria, gastrointestinal bleeding, inflammation, and intravascular and extravascular hemolysis are all ways iron is lost during strength training. In training, evaluating the iron status, particularly in athletes at risk of iron deficiency, may work on improving iron balance and possibly effectiveness. Iron status is influenced by a healthy gut microbiome. To eliminate hemolysis, athletes at risk of iron deficiency should engage in non-weight-bearing, low-intensity sporting activities.