• Journal of Veterinary Science
• /
• 제23권5호
• /
• pp.74.1-74.16
• /
• 2022

Background: Previous studies have presented evidence to support the significant association between red meat intake and colon cancer, suggesting that heme iron plays a key role in colon carcinogenesis. Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, exhibits anti-oxidative and anti-cancer effects. However, the effect of EGCG on red meat-associated colon carcinogenesis is not well understood. Objectives: We aimed to investigate the regulatory effects of hemin and EGCG on colon carcinogenesis and the underlying mechanism of action. Methods: Hemin and EGCG were treated in Caco2 cells to perform the water-soluble tetrazolium salt-1 assay, lactate dehydrogenase release assay, reactive oxygen species (ROS) detection assay, real-time quantitative polymerase chain reaction and western blot. We investigated the regulatory effects of hemin and EGCG on an azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colon carcinogenesis mouse model. Results: In Caco2 cells, hemin increased cell proliferation and the expression of cell cycle regulatory proteins, and ROS levels. EGCG suppressed hemin-induced cell proliferation and cell cycle regulatory protein expression as well as mitochondrial ROS accumulation. Hemin increased nuclear factor erythroid-2-related factor 2 (Nrf2) expression, but decreased Keap1 expression. EGCG enhanced hemin-induced Nrf2 and antioxidant gene expression. Nrf2 inhibitor reversed EGCG reduced cell proliferation and cell cycle regulatory protein expression. In AOM/DSS mice, hemin treatment induced hyperplastic changes in colon tissues, inhibited by EGCG supplementation. EGCG reduced the hemin-induced numbers of total aberrant crypts and malondialdehyde concentration in the AOM/DSS model. Conclusions: We demonstrated that EGCG reduced hemin-induced proliferation and colon carcinogenesis through Nrf2-inhibited mitochondrial ROS accumulation.

• 한국어병학회지
• /
• 제26권3호
• /
• pp.295-301
• /
• 2013

Ferritin is an evolutionarily conserved protein that plays an important role in iron storage and detoxification. In this study, the gene encoding a ferritin H subunit homologue (RbFH) was cloned from rock bream (Oplegnathus fasciatus) and analyzed at the expression. The full-length ferritin H cDNA was 1162 bp long and contained an open reading frame (ORF) of 531 bp that encoded 177 amino acid residues with a predicted molecular mass of 20.8 kDa. The 5' UTR was 297 bp in length, and the 3' UTR 298 bp, and preceded by a 5'-untranslated region that contains a putative Iron Regulatory Element (IRE). The deduced amino acid sequence of RbFH shares extensive sequence identities with the H ferritins of a number of fish species and contains the ferroxidase center that is preserved in ferritin H subunits. Examination of tissue specific expression indicated that RbFH expression was most abundant in PBLs, RBC, liver and muscle.

• BMB Reports
• /
• 제39권5호
• /
• pp.479-491
• /
• 2006

Heme oxygenase (HO), the rate limiting enzyme in the breakdown of heme into carbon monoxide (CO), iron and bilirubin, has recently received overwhelming research attention. To date three mammalian HO isozymes have been identified, and the only inducible form is HO-1 while HO-2 and HO-3 are constitutively expressed. Advances in unveiling signal transduction network indicate that a battery of redox-sensitive transcription factors, such as activator protein-1 (AP-1), nuclear factor-kappa B (NF-${\kappa}B$) and nuclear factor E2-related factor-2 (Nrf2), and their upstream kinases including mitogen-activated protein kinases play an important regulatory role in HO-1 gene induction. The products of the HO-catalyzed reaction, particularly CO and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression contributes to protection against liver damage induced by several chemical compounds such as acetaminophen, carbon tetrachloride and heavy metals, suggesting HO-1 induction as an important cellular endeavor for hepatoprotection. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect against chemically-induced liver injury as well as hepatocarcinogenesis.

• 한국환경성돌연변이발암원학회지
• /
• 제25권4호
• /
• pp.134-142
• /
• 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 Microbiology and Biotechnology
• /
• 제10권5호
• /
• pp.700-706
• /
• 2000

Iron- and zinc-containing superoxide dismutase (FeZnSOD) and nickel-containing superoxide dismutase (NiSOD) are cytoplamic enzymes in Streptomyces griseus. The sodF gene coding for FeZnSOD was cloned from genomic Southern hybridization analysis with a 0.5-kb DNA probe, which was PCR-amplified with facing primers corresponding to the N-terminal amino acid of the purified FeZnSOD of S. griseus and a C-terminal region which is conserved among bacterial FeSODs and MnSODs. The sodF open reading frame (ORF) was comprised of 213 amino acid (22,430 Da), and the deduced sequence of the protein was highly homologous (86% identity) to that of FeZnSOD of Streptomyces coelicolor. The FeZnSOD expression of exponentially growing S. griseus cell was approximately doubled as the cell growth reached the early stationary phase. The growth-associated expression of FeZnSOD was mainly controlled at the transcriptional level, and the regulation was exerted through the 110 bp regulatory DNA upstream from the ATG initiation codon of the sodF gene.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.36-36
• /
• 2017

Out of twenty common protein amino acids, there are many kinds of non protein amino acids (NPAAs) that exist as secondary metabolites and exert ecological functions in plants. Mimosine (Mim), one of those NPAAs derived from L. leucocephala acts as an iron chelator and reversely block mammalian cell cycle at G1/S phases. Cysteine (Cys) is decisive for protein and glutathione that acts as an indispensable sulfur grantor for methionine and many other sulfur-containing secondary products. Cys biosynthesis includes consecutive two steps using two enzymes-serine acetyl transferase (SAT) and O-acetylserine (thiol)lyase (OASTL) and appeared in plant cytosol, chloroplast, and mitochondria. In the first step, the acetylation of the ${\beta}$-hydroxyl of L-serine by acetyl-CoA in the existence of SAT and finally, OASTL triggers ${\alpha}$, ${\beta}$-elimination of acetate from OAS and bind $H_2S$ to catalyze the synthesis of Cys. Mimosine synthase, one of the isozymes of the OASTLs, is able to synthesize Mim with 3-hydroxy-4-pyridone (3H4P) instead of $H_2S$ for Cys in the last step. Thus, the aim of this study was to clone and characterize the cytosolic (Cy) OASTL gene from L. leucocephala, express the recombinant OASTL in Escherichia coli, purify it, do enzyme kinetic analysis, perform docking dynamics simulation analysis between the receptor and the ligands and compare its performance between Cys and Mim synthesis. Cy-OASTL was obtained through both directional degenerate primers corresponding to conserved amino acid region among plant Cys synthase family and the purified protein was 34.3KDa. After cleaving the GST-tag, Cy-OASTL was observed to form mimosine with 3H4P and OAS. The optimum Cys and Mim reaction pH and temperature were 7.5 and $40^{\circ}C$, and 8.0 and $35^{\circ}C$ respectively. Michaelis constant (Km) values of OAS from Cys were higher than the OAS from Mim. Inter fragment interaction energy (IFIE) of substrate OAS-Cy-OASTL complex model showed that Lys, Thr81, Thr77 and Gln150 demonstrated higher attraction force for Cys but 3H4P-mimosine synthase-OAS intermediate complex showed that Gly230, Tyr227, Ala231, Gly228 and Gly232 might provide higher attraction energy for the Mim. It may be concluded that Cy-OASTL demonstrates a dual role in biosynthesis both Cys and Mim and extending the knowledge on the biochemical regulatory mechanism of mimosine and cysteine.

• 대한치과교정학회지
• /
• 제31권6호
• /
• pp.589-600
• /
• 2001

이 연구의 목적은 IGF-I의 골모세포에 대한 직접적 작용효과와 IGF-I이 섬유모세포에 작용된 후 섬유모세포에서 유리된 인자를 포함한 조절 배양액이 골모세포에 어떤 영향을 미치는지에 대해 각각 치주인대 섬유모세포와 치은 섬유모세포를 이용하여 알아본 후, 치조골의 반응을 외적자극과의 사이에서 매개하는 치주인대의 주세포군인 섬유모세포를 통한 IGF-I의 골모세포에 대한 영향을 알아보는 것이다. 이를 위해 치주인대 섬유모세포와 치은 섬유모세포를 6-8주된 백서(Sprague-Dawley rat)에서 채집하고, 골모세포는 태생 21일된 동종백서에서 채집하여 기본배양을 한 후, 각 군을 6군으로 분리하여 $1{\times}10^4$/we11, (1ml/well)세포수로 분주한 골모세포 배양접시에 IGF-I을 1,10,100ng/m1로 각각 농도를 달리하여 그 효과를 알아보았다. 각각의 군은 대조군, IGF-I을 직접 투여한 골모세포 배양군, 치주인대 섬유모세포의 조절배양액을 이용한 골모세포 배양군, IGF-I으로 처리한 치주인대 섬유모세포의 조절배양액을 이용한 골모세포 배양군, 치은 섬유모세포의 조절배양액을 이용한 골모세포 배양군, IGF-I으로 처 리한 치은 섬유모세포의 조절배양액을 이용한 골모세포 배양군이다. 조절배양액은 배양 36시간후(IGF-I 처리후 12시 간 배양 포함) 채집하였고, 마지막으로 IGF-I 및 조절배양액으로 처리한 후에 추가 24시간 배양한 후, Alkaline phoaphatase 활성도, Western blot 을 이용한 BMP발현, MTT를 이용한 세포증식, BCA kit을 이용한 총단백질량 측정, Western blot을 이용한 교원질 합성 계측 및 골결절의 생성을 관찰하였다. 본 연구의 결과는 다음과 같다. 1 Alkaline phosphatase활성은 10, 100ng/m1의 IGF-I으로 처리한 군과 치주인대 섬유모세포의 조절배양액을 이용한 군, IGF-I으로 처리한 치주인대 섬유모세포의 조절배양액을 이용한 군에서 대조군보다 더 높게 나타났다. 10, 100ng/ml의 IGF-I으로 처리한 치주인대 섬유모세포의 조절배양액을 이용한 실험군에서 유의성 있게 높게 나타났다. 2. 100ng/m1농도의 IGF-I으로 직접 처리한 군에서 골모세포증식이 유의성 있게 증가하였다. 3. 총단백질량은 IGF-I투여와 상관없이 대조군, 실험군 모두 유사하였다. 4. 모든 실험군에서 BMP2,4가 발현되었고, 대조군과 유의한 차이는 없었다. 이상의 결과에서 IGF-I의 투여여부와는 상관없이 치주인대 섬유모세포가 유리하는 물질이 골모세포의 활성을 증가시키는 것으로 나타났으며, IGF-I은 고농도일때만 유의성있게 골모세포 활성을 촉진함을 알 수 있었다. 따라서 이 연구를 통하여 치주인대 섬유모세포가 골모세포활성을 촉진 시키는 작용을 가지고 있음이 확인되었다.