• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4949-4954
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• 2015

The present study was planned to investigate the role of sex hormone receptor gene expression in the pathogenesis of hepatocellular carcinoma (HCC). Adult male Wistar rats were divided into seven groups. Group (1) was negative control. Groups (2), (5), (6), and (7) were orally administered with N-nitrosodiethylamine for the induction of HCC, then group (2) was left untreated, group (5) was orally treated with curcumin, group (6) was orally treated with carvacrol, and group (7) was intraperitoneally injected with doxorubicin, whereas groups (3) and (4) were orally administered only curcumin and carvacrol, respectively. The HCC group showed significant upregulation in the androgen receptor (AR) and the estrogen receptor-alpha ($ER{\alpha}$) gene expression levels in the liver tissue. On the contrary, HCC groups treated with either curcumin or carvacrol showed significant downregulation in AR and $ER{\alpha}$ gene expression levels in the liver tissue. In conclusion, the obtained data highlight that both AR and $ER{\alpha}$ but not estrogen receptor-beta ($ER{\beta}$) gene expression may contribute to the male prevalence of HCC induced in male rats. Interestingly, both curcumin and carvacrol were found to have a promising potency in alleviating the male predominating HCC.

• BMB Reports
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• 제31권2호
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• pp.123-129
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• 1998

Foreign proteins, $endo-{\beta}-1,4-glucanase$ of Bacillus subtilis, preS1+S2 region of hepatitis B virus large surface antigen, human ${\beta}_2-adrenergic$ receptor ($h{\beta}_{2}AR$), and bovine growth hormone (bGH) were expressed in Saccharomyces cerevisiae and secreted into the medium. These proteins were expressed using the alcohol dehydrogenase I (ADH1) promoter of Saccharomyces cerevisiae and secreted by signal sequence of the 97 K killer toxin gene of doublestranded linear DNA plasmid (pGKL1) of S. cerevisiae. All these proteins underwent severe modifications; in particular, N-glycosylation in the case of $endo-{\beta}-1,4-glucanase$, $h{\beta}_2AR$, and preS1+S2. Seventy four percent of the expressed $endo-{\beta}-1,4-glucanase$ was secreted into the culture medium. Highly modified proteins were detected in the culture medium and in the cell. Expressed $h{\beta}_2AR$, which has seven transmembrane domains, remained in the cell. The degrees of secretion and modification and the states of proteins in the culture medium and in the cell were quite different. These results indicated that the nature of the protein has a critical role in its secretion and modifications.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.251-259
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• 2013

An endoxylanase gene (PoxynA) that belongs to the glycoside hydrolase (GH) family 11 was cloned from a xylanolytic strain, Penicillium oxalicum B3-11(2). PoxynA was overexpressed in Trichoderma reesei QM9414 by using a constitutive strong promoter of the encoding pyruvate decarboxylase (pdc). The high extracellular xylanase activities in the fermentation liquid of the transformants were maintained 29~35-fold higher compared with the wild strain. The recombinant POXYNA was purified to homogeneity, and its characters were analyzed. Its optimal temperature and pH value were $50^{\circ}C$ and 5.0, respectively. The enzyme was stable at a pH range of 2.0 to 7.0. Using beechwood as the substrate, POXYNA had a high specific activity of $1,856{\pm}53.5$ IU/mg. In the presence of metal ions, such as $Cu^{2+}$, and $Mg^{2+}$, the activity of the enzyme increased. However, strong inhibition of the enzyme activity was observed in the presence of $Mn^{2+}$ and $Fe^{2+}$. The recombinant POXYNA hydrolyzed birchwood xylan, beechwood xylan, and oat spelt xylan to produce short-chain xylooligosaccharides, xylopentaose, xylotriose, and xylobiose as the main products. This is the first report on the expression properties of a recombinant endoxylanase gene from Penicillium oxalicum. The properties of this endoxylanase make it promising for applications in the food and feed industries.

• BMB Reports
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• 제53권2호
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• pp.100-105
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• 2020

While liver histopathology is heterogeneous in diabetes, the underlying mechanisms remain unclear. We investigated whether glycemic variation resulting from differential diets can induce heterogeneity in diabetic liver and the underlying molecular mechanisms. We generated end-stage non-obese diabetic model rats by subtotal-pancreatectomy in male Sprague-Dawley rats and ad libitum diet for 7 weeks (n = 33). The rats were then divided into three groups, and fed a standard- or a low-protein diet (18 or 6 kcal%, respectively), for another 7 weeks: to maintain hyperglycemia, 11 rats were fed ad libitum (18AL group); to achieve euglycemia, 11 were calorie-restricted (18R group), and 11 were both calorie- and protein-restricted with the low-protein diet (6R group). Overnight-fasted liver samples were collected after the differential diets together with sham-control (18S group), and histology and molecular changes were compared. Hyperglycemic-18AL showed glycogenic hepatopathy (GH) without steatosis, with the highest GSK-3β inactivation because of Akt activation during hyperglycemia; mitochondrial function was not impaired, compared to the 18S group. Euglycemic-18R showed neither GH nor steatosis, with intermediate GSK-3β activation and mitochondrial dysfunction. However, euglycemic-6R showed both GH and steatosis despite the highest GSK-3β activity and no molecular evidence of increased lipogenesis or decreased ApoB expression, where mitochondrial dysfunction was highest among the groups. In conclusion, heterogeneous liver histopathology developed in end-stage non-obese diabetic rats as the glycemic levels varied with differential diets, in which protein content in the diets as well as glycemic levels differentially influenced GSK-3β activity and mitochondrial function in insulin-deficient state.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.160-166
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• 2008

A DNA fragment containing 2,079 base pairs from Bacillus circulans CGMCC 1416 was cloned using degenerate PCR and inverse PCR. An open reading frame containing 981 bp was identified that encoding 326 amino acids residues, including a putative signal peptide of 31 residues. The deduced amino acid sequence showed the highest identity (68.1%) with $endo-{\beta}-1,4-D-mannanase$ from Bacillus circulans strain K-1 of the glycoside hydrolase family 5 (GH5). The sequence encoding the mature protein was cloned into the pET-22b(+) vector and expressed in Escherichia coli as a recombinant fusion protein containing an N-terminal hexahistidine sequence. The fusion protein was purified by $Ni^{2+}$ affinity chromatography and its hexahistidine tag cleaved to yield a 31-kDa ${\beta}$-mannanase having a specific activity of 481.55U/mg. The optimal activity of the purified protein, MANB48, was at $58^{\circ}C$ and pH 7.6. The hydrolysis product on substrate locust bean gum included a monosaccharide and mainly oligosaccharides. The recombinant MANB48 may be of potential use in the feed industry.

• 한국발생생물학회지:발생과생식
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• 제13권4호
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• pp.207-215
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• 2009

시상하부-뇌하수체-생식소(hypothalamus-pituitary-gonad, HPG) 호르몬 축의 활성에 영향을 미치는 수많은 인자들은 생식 기능을 조절하고, 사춘기 개시와 폐경기 진입과 같은 뚜렷한 생식 능력의 단계 전이를 초래한다. 지방세포로부터 분비되는 다기능적 호르몬인 leptin의 발견 이후, 곧 이어 생식과 신체의 에너지 균형 사이의 긴밀한 관계에 대한 증거들이 밝혀졌다. 위장관으로부터 분비되는 또 다른 다기능 호르몬인 ghrelin은 이미 알려져 있던 growth hormone secretagogue receptor(GHSR)의 내인성 리간드이며, 에너지 항상성의 조절에서 leptin에 상응하는 물질로 알려졌다. 예상대로, ghrelin 또한 HPG 축의 활성의 조절을 통해 생식 능력을 조절함이 증명되었다. 이 논문은 ghrelin의 발견과 유전자 구조, 조직 내의 분포, 그리고 역할과 HPG 축에서의 생식 호르몬 분비 조절에 대한 포유동물의 생식에서의 ghrelin-GHSR 신호에 관한 최신 정보를 요약한 것이다. 뇌하수체에서의 POMC 유전자 발현과 유사하게, preproghrelin 유전자는 alternative splicing과 번역 후 변형(posttranslational modification)을 거치는 복잡한 레퍼토리의 전사체들과 펩티드 산물을 만들어 낸다. 에너지 항상성을 제외한 신체 생리 기능의 조절에서의 preproghrelin 유전자 산물의 역할에 관한 정보는 제한적이지만, 신진 대사와 생식 사이에서의 ghrelin의 상호작용에 관해서는 충분한 증거들이 있다. 흰쥐와 인간에서, ghrelin 수용체인 GHSRs(GHSR1a와 GHSR1b)의 분포는 본래 ghrelin의 표적으로 여겨진 시상하부와 뇌하수체뿐만 아니라 정소와 난소에서도 확인되었다. 뇌와 생식소에서도 preproghrelin 유전자 발현이 확인되었는데, 이것은 HPG 축에서 ghrelin이 국부적인 역할을 담당할 가능성을 시사한다. 비록 뇌하수체에서의 기능은 아직 확실치 않지만, ghrelin은 시상하부의 GnRH, 뇌하수체의 생식소자극호르몬과 생식소의 성 스테로이드 호르몬 분비에 대한 음성적인 조절자로서의 역할을 수행하는 것으로 보인다. 최근의 연구들은 사춘기 개시, 그리고 아마도 폐경기 진입의 조절에서 ghrelin의 관여를 시사한다. 이제 ghrelin이 '뇌-위장관' 축의 필수적인 호르몬 요인이며, 신 진 대사와 생식 사이를 연결하는 조절 물질이라는 가능성은 매우 높다. '배부름'을 반영하는 leptin 신호와는 정반대인 ghrelin 신호는 신체 에너지 균형 상태로 볼 때 '배고픔'을 표현하는 것으로 생각되며, 항상성의 유지에서 최우선 사항으로 고려되지 않는 생식으로의 에너지 투자가 이루어지지 않도록 하는데 필수적일 것으로 사료된다. 생식능력 조절에 있어서 ghrelin의 보다 명확한 작용 메커니즘과 역할에 대한 깊은 통찰력을 얻고 성공적인 생의학적 적용을 위해서는 향후 더 많은 연구들이 필요하다.