• 생명과학회지
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• 제26권12호
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• pp.1487-1497
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• 2016

정족수 인식 체계라 불리는 세균들의 세포간 의사교환 전략은 다양한 유전자의 발현조절을 통해, 생물막 성숙, 세포 외 고분자물질의 생산, 병원성 발현 및 항생제 생산 등과 같은 다양한 표현형을 조절하는 세균의 다세포성 행동 양식을 제어한다. 다수의 연구에 의하면 많은 종류의 그람 (Gram)음성 세균들이 정족수 인식체계에 필요한 신호전달 물질로 acyl-homoserine lactones (AHLs)를 사용하고 있으며, 이들은 생물막 형성에 중요한 인자로 작용함을 시사하였다. 이러한 정족수 인식체계에 의한 생물막의 형성은 물이 존재하는 모든 표면환경에서 불필요한 바오매스 축적이라는 심각한 기술적, 경제적 문제를 초래하고 있다. 최근 정족수 인체 체계를 교란하는 다수의 물질들이 다양한 미생물로부터 발견되어, 그들의 정족수 인식 체계와 관련된 주요 기능과 기작들이 밝혀지고 있다. 이러한 정족수 제어 물질들은 최근 다양한 산업에서 발생하는 생물 부착현상들을 제어할 수 있는, 환경 친화적이며 세균의 항생제 다재 내성을 완화 시킬 수 있는 새로운 방법으로 대두되고 있다. 따라서 본 논문은 세균의 정족수 인식 체계와 관련된 최근 정보, 정족수 인식 신호를 제어할 수 있는 정족수 제어 효소와 이러한 기술을 이용한 생물 부착 저해 방법 등을 논의하고자 한다.

• Parasites, Hosts and Diseases
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• 제48권4호
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• pp.291-295
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• 2010

The onset, severity, and ultimate outcome of malaria infection are influenced by parasite-expressed virulence factors and individual host responses to these determinants, In both humans and mice, liver injury is involved after parasite entry, which persists until the erythrocyte stage after infection with the fatal strain Plasmodium falciparum (Pf), Hepatocyte growth factor (HGF) has strong anti-apoptotic effects in various kinds of cells, and also has diverse metabolic functions. In this work, Pf-subtilisin-like protease 2 (Pf-Sub2) 5' untranslated region (UTR) was analyzed and its transcriptional activity was estimated by luciferase expression. Fourteen TATA boxes were observed but only one Oct-1 and c-Myb were done. In addition, host HGF interaction with Pf-Sub2 was evaluated by co-transfection of HGF- and Pf-Sub2-cloned vector. Interestingly, -1,422/+12 UTR exhibited the strongest luciferase activity but -329 to + 12 UTR did not exhibit luciferase activity. Moreover, as compared with the control of unexpressed HGF, the HGF protein suppressed luciferase expression driven by the 5' untranslated region of the Pf-Sub2 promoter. Taken together, it is suggested that HGF controls and interacts with the promoter region of the Pf-Sub2 gene.

• 대한수의학회지
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• 제51권3호
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• pp.193-201
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• 2011

An attenuated vaccine strain AVR1/08 of Korean respiratory type of infectious bronchitis virus (IBV) was developed by 89th passages of IBV D85/06 strain in chicken eggs. The AVR1/08 strain had higher virus titer at least 20 times ($10^{1.3}$) than the parent virus D85/06 by egg inoculation method. The AVR1/08 strain had a single point mutation (S to Y) at position 56 of spike protein of IBV compared to parent virus IBV D85/06 strain. The mutation was observed consistently at viruses after 47th passage in chicken eggs. The AVR1/08 strain showed no virulence even after 6 passages in chickens and all chickens inoculated induced anti-IBV antibody 14 days after vaccination. The AVR1/08 strain had broad protective efficacy against QX type Korean nephropathogenic virus (Q43/06 strain), KM91 type Korean nephropathogenic virus (KM91 strain) and Korean respiratory virus (D85/06 strain). In contrast, Massachusetts (Mass) type attenuated vaccine strain H120 showed protection of 37.5 to 50% against these three viruses. Our results indicate that the AVR1/08 strain has potential as an attenuated vaccine effective in controlling IBVs circulating in Korea.

• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.79-83
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• 2011

Trichomoniasis is a sexually transmitted disease due to infection with Trichomonas vaginalis, and it can cause serious consequences for women's health. To study the virulence factors of this pathogen, T. vaginalis surface proteins were investigated using polyclonal antibodies specific to the membrane fractions of T. vaginalis. The T. vaginalis expression library was constructed by cloning the cDNA derived from mRNA of T. vaginalis into a phage ${\lambda}$ Uni-ZAP XR vector, and then used for immunoscreening with the anti-membrane proteins of T. vaginalis antibodies. The immunoreactive proteins identified included adhesion protein AP65-1, ${\alpha$-actinin, kinesin-associated protein, teneurin, and 2 independent hypothetical proteins. Immunofluorescence assays showed that AP65-1, one of the identified immunogenic clones, is prevalent in the whole body of T. vaginalis. This study led us to identify T. vaginalis proteins which may stimulate immune responses by human cells.

• 생명과학회지
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• 제26권10호
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• pp.1214-1217
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• 2016

Rebamipoide는 위궤양과 위염치료에 쓰이는 위보호제로 임상에서 사용되고 있지만 위암에서의 역할에 대해서는 알려지바가 거의 없다. 헬리코박토 파일로리(Helicobacter pylori)의 주요독성인자인 CagA는 위암의 발생과 관련이 있다. CagA는 위암세포에서 NFκB의 활성을 증가시켜 PLD1 단백질의 발현을 증가시킴으로써 위암세포의 증식과 침윤을 유도한다. Rebamipide는 NFκB의 활성을 억제함으로써 H. pylori의 CagA에 의해 유도되는 PLD1의 발현을 저해하는것으로 규명되었다. 게다가, rebamipide는 H. pylori의 CagA에 의해 유도되는 β-catenin과 그 표적 유전자로서 인 암줄기세포 마커 단백질의 발현을 증가시킴으로써 위암줄기세포의 자가재생능력을 감소시킨다. 또한 rebamipide는 항암제 내성을 극복하는 화학감수성을 증가시켜서 위암생성을 감소시키는 것으로 나타났다. 그래서 rebamipide는 위암치료제로서의 잠재적 효능을 가지고 있는 약물로서의 가능성이 제시되고 있다.

• 한국축산식품학회지
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• 제39권1호
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• pp.84-92
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• 2019

Listeria monocytogenes is a major cause of serious foodborne illness in the dairy foods. Although Caenorhabditis elegans model is well established as a virulence model of pathogenic bacteria, its application on L. monocytogenes is critically unclear. The objective of this study was to carry out an evaluation of L. monocytogenes toxicity using C. elegans nematode as a simple host model. We found that C. elegans nematodes have high susceptibility to L. monocytogenes infection, as a consequence of accumulation of bacteria in the worms' intestine. However, L. innocua, which is known to be non-toxic, is not accumulate in the intestine of worms and is not toxic similarly to Escherichia coli OP50 known as the normal feed source of C. elegans. Importantly, immune-associated genes of C. elegans were intensely upregulated more than 3.0-fold when they exposed to L. monocytogenes. In conclusion, we established that C. elegans is an effective model for studying the toxicity of L. monocytogenes and we anticipate that this system will result in the discovery of many potential anti-listeria agents for dairy foods.

• Parasites, Hosts and Diseases
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• 제59권6호
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• pp.573-583
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• 2021

Toxoplasma gondii, an intracellular protozoan parasite that infects one-third of the world's population, has been reported to hijack host cell apoptotic machinery and promote either an anti- or proapoptotic program depending on the parasite virulence and load and the host cell type. However, little is known about the regulation of human FHs 74 small intestinal epithelial cell viability in response to T. gondii infection. Here we show that T. gondii RH strain tachyzoite infection or ESP treatment of FHs 74 Int cells induced apoptosis, mitochondrial dysfunction and ER stress in host cells. Pretreatment with 4-PBA inhibited the expression or activation of key molecules involved in ER stress. In addition, both T. gondii and ESP challenge-induced mitochondrial dysfunction and cell death were dramatically suppressed in 4-PBA pretreated cells. Our study indicates that T. gondii infection induced ER stress in FHs 74 Int cells, which induced mitochondrial dysfunction followed by apoptosis. This may constitute a potential molecular mechanism responsible for the foodborne parasitic disease caused by T. gondii.

• Journal of Ginseng Research
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• 제46권6호
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• pp.790-800
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• 2022

Background: Panax ginseng Meyer is one of the most valuable medicinal plants which is enriched in anti-microbe secondary metabolites and widely used in traditional medicine. Botrytis cinerea is a necrotrophic fungus that causes gray mold disease in a broad range of hosts. B. cinerea could overcome the ginseng defense and cause serious leaf and root diseases with unknown mechanism. Methods: We conducted simultaneous transcriptomic and metabolomic analysis of the host to investigate the defense response of ginseng affected by B. cinerea. The gene deletion and replacement were then performed to study the pathogenic gene in B. cinerea during ginseng - fungi interaction. Results: Upon B. cinerea infection, ginseng defense responses were switched from the activation to repression, thus the expression of many defense genes decreased and the biosynthesis of antifungal metabolites were reduced. Particularly, ginseng metabolites like kaempferol, quercetin and luteolin which could inhibit fungi growth were decreased after B. cinerea infection. B. cinerea quercetin dioxygenase (Qdo) involved in catalyzing flavonoids degradation and ∆BcQdo mutants showed increased substrates accumulation and reduced disease development. Conclusion: This work indicates the flavonoids play a role in ginseng defense and BcQdo involves in B. cinerea virulence towards the P. ginseng. B. cinerea promotes disease development in ginseng by suppressing of defense related genes expression and reduction of antifungal metabolites biosynthesis.

• 치위생과학회지
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• 제23권4호
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• pp.296-301
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• 2023

Background: Periodontal disease is a major cause of tooth loss in adults and is a representative oral disease commonly suffered by most people around the world. Mainly the proliferation of Gram-negative bacteria and secreted virulence factors cause an inflammatory response and destroy periodontal tissue. Gossypetin, isolated from Hibiscus sabdariffa L, is known to have various pharmacological effects, including antibacterial and anticancer activities. We aimed to confirm the anti-inflammatory effect of gossypetin through interleukin-6 (IL-6) regulation in human gingival fibroblasts (HGFs) stimulated with lipopolysaccharide (LPS) of Porphyromonas gingivalis, a major cause of adult periodontitis. Methods: CCK-8 assay was performed to confirm the concentration-dependent cytotoxicity of gossypetin against HGFs. The secretion level and mRNA expression of IL-6, an inflammation-related cytokine, and the effect of gossypetin on these in HGFs stimulated with P. gingivalis LPS were confirmed by ELISA and qRT-PCR analysis, respectively. Results: Up to a concentration of 100 µM gossypetin with or without P. gingivalis LPS, the survival rate for HGFs was maintained at over 95% and showed no toxicity. ELISA and qRT-PCR analysis results showed that P. gingivalis LPS increased IL-6 secretion and mRNA levels in HGFs compared to the control group. However, this increase in IL-6 was significantly down-regulated by gossypetin treatment in a dose-dependent manner. In particular, 80 µM gossypetin inhibited IL-6 production to the level of the control group. Conclusion: These results indicated that gossypetin attenuated IL-6 production in HGFs stimulated by P. gingivalis LPS, which may ultimately suppress the inflammatory response in periodontal tissue. Therefore, gossypetin may have potential as a natural ingredient for the prevention and treatment of periodontal disease.

• Journal of Periodontal and Implant Science
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• 제31권4호
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• pp.661-668
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• 2001

P. gingivalis를 단독면역하거나 또는 Fusobacterium nucleatum 선면역 후 P. gingivalis 항혈청을 각각 얻어냈다. 두 종류의 항혈청이 P. gingivalis biofilm을 침투해 들어가는 능력을 confocal laser scanning microscope를 이용하여 비교 감증하였다. 항혈청의 P. gingivalis에 대한 avidity index도 측정하였다. 결과적으로 F. nucleatum의 선면역은 P. gingivalis 특이 항혈청에 대해 세균성 biofilm의 침투능력을 저하시키고, 동일한 세균에 대한 avidity도 감소시켰다.