• 한국미생물·생명공학회지
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• 제49권4호
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• pp.467-477
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• 2021

Staphylococcus aureus is a well-known pathogen that can cause diseases in humans. It can cause both mild superficial skin infections and serious deep tissue infections, including pneumonia, osteomyelitis, and infective endocarditis. To establish host infection, S. aureus manages a complex regulatory network to control virulence factor production in both temporal and host locations. Among these virulence factors, staphyloxanthin, a carotenoid pigment, has been shown to play a leading role in S. aureus pathogenesis. In addition, staphyloxanthin provides integrity to the bacterial cell membrane and limits host oxidative defense mechanisms. The overwhelming rise of Staphylococcus resistance to routinely used antibiotics has necessitated the development of novel anti-virulence agents to overcome this resistance. This review presents an overview of the chief virulence determinants in S. aureus. More attention will be paid to staphyloxanthin, which could be a possible target for anti-virulence agents.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.1-10
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• 2004

Many bacteria monitor their population density and control the expression of specialized gene sets in response to bacterial cell density based on a mechanism referred to as quorum sensing. In all cases, quorum sensing involves the production and detection of extracellular signaling molecules, auto inducers, as which Gram-negative and Gram-positive bacteria use most prevalently acylated homoserine lactones and processed oligo-peptides, respectively. Through quorum-sensing communication circuits, bacteria regulate a diverse array of physiological functions, including virulence, symbiosis, competence, conjugation, antibiotic production, motility, sporulation, and biofilm formation. Many pathogens have evolved quorum-sensing mechanisms to mount population-density-dependent attacks to over-whelm the defense responses of plants, animals, and humans. Since these AHL-mediated signaling mechanisms are widespread and highly conserved in many pathogenic bacteria, the disruption of quorum-sensing system might be an attractive target for novel anti-infective therapy. To control AHL-mediated pathogenicity, several promising strategies to disrupt bacterial quorum sensing have been reported, and several chemicals and enzymes have been also investigated for years. These studies indicate that anti-quorum sensing strategies could be developed as possible alternatives of antibiotics.

• IMMUNE NETWORK
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• 제20권5호
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• pp.37.1-37.15
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• 2020

Mycobacterium tuberculosis (Mtb) is an etiologic pathogen of human tuberculosis (TB), a serious infectious disease with high morbidity and mortality. In addition, the threat of drug resistance in anti-TB therapy is of global concern. Despite this, it remains urgent to research for understanding the molecular nature of dynamic interactions between host and pathogens during TB infection. While Mtb evasion from phagolysosomal acidification is a well-known virulence mechanism, the molecular events to promote intracellular parasitism remains elusive. To combat intracellular Mtb infection, several defensive processes, including autophagy and apoptosis, are activated. In addition, Mtb-ingested phagocytes trigger inflammation, and undergo necrotic cell death, potentially harmful responses in case of uncontrolled pathological condition. In this review, we focus on Mtb evasion from phagosomal acidification, and Mtb interaction with host autophagy, apoptosis, and necrosis. Elucidation of the molecular dialogue will shed light on Mtb pathogenesis, host defense, and development of new paradigms of therapeutics.

• 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.

• 대한한의학회지
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• 제16권2호
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• pp.149-176
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• 1995

The results were as follow: 1. In classification of the virulence of medicines, it is the virulent animal that have a deadly poison and the rest is the animal of weak nor non-toxic. 2. In classification of the channel distribution, the most is the medicine that belongs to liver channel, the next are the stomach, lung, kidney and spleen channel. 3. In classification of four characters, the most parts are cool, common and warm medicine and there is a few that is hot and cooling. 4. In classification of five tastes, the most numerous tastes are sweet and salty and the next are acrid, bitter and sour tastes. 5. In classification of the medical action, there are few medicine of invigorating vital energy, tonic therapy and astringent and a great part of the medicine are regulating vital energy and blood, removing blood stasis and mass, clearing away heat-evil and eliminating sputum, calming the river to inhibit the wind-evil and pain control. 6. In classification of the application of cancer, the most numerous disease is the liver cancer and the next are stomach cancer, esophageal cancer, lung cancer, leukemia, uterine cancer,mastitis, brain tumor.

• 한국콘텐츠학회논문지
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• 제12권2호
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• pp.339-348
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• 2012

급성 전골수구성 백혈병(acute promyelocytic leukemia, APL)은 치료제가 한정적이고 그 또한 다양한 부작용을 초래한다. 최근 암세포 형성 억제에 세균 추출물을 사용하는 경우가 증가하는데 이를 이용하여 기존의 약제보다 효과적이면서 부작용이 적은 치료제 개발이 필요하다. 본 연구에서는 L. monocytogenes에서 분비되는 물질(LmSup)과 세균 자체가 함유하고 있는 물질(LmE)을 추출하여 HL-60 세포에 처리한 다음 세포증식 억제 효과를 보고자 하였다. 세포 생존율 및 세포고사를 확인하여 세포를 죽음으로 유도하는 지 파악한 다음 작용기전을 규명하고자 세포주기의 변화 및 ROS 생성을 관찰하였다. 그 결과, LmSup와 LmE가 급성 전골수구성 백혈병(APL) 세포인 HL-60의 세포고사를 유도하고, sub G0/G1기 증가로 세포주기를 비정상적으로 차단함으로써 세포고사를 유도함을 확인하였다. 이때, ROS가 관여함을 관찰하였다. 이를 통해, LmSup 또는 LmE의 구체적인 항암효과 및 기전 분석을 통해 난치병인 APL의 치료 방법 및 치료제 개발에 기여하고자 한다.