• BMB Reports
• /
• 제38권5호
• /
• pp.624-631
• /
• 2005

Tuberculosis, caused by Mycobacterium tuberculosis, continues to be one of the main diseases to mankind. It is urgent to discover novel drug targets for appropriate antimicrobial agents against this human pathogen. The shikimate pathway is onsidered as an attractive target for the discovery of novel antibiotics for its essentiality in bacteria and absence in mammalian cells. The Mycobacterium tuberculosis aroE-encoded shikimate dehydrogenase was cloned, expressed and purified. Sequence alignment analysis shows that shikimate dehydrogenase of Mycobacterium tuberculosis exhibit the pattern of G-X-(N/S)-V-(T/S)-X-PX-K, which is highly conserved within the shikimate dehydrogenase family. The recombinant shikimate dehydrogenase spectrum determined by CD spectroscopy showed that the percentages for $\alpha$-helix, $\beta$-sheet, $\beta$-turn, and random coil were 29.2%, 9.3%, 32.7%, and 28.8%, respectively. The enzymatic characterization demonstrates that it appears to be fully active at pH from 9.0 to 12, and temperature $63^{\circ}C$. The apparent Michaelis constant for shikimic acid and $NADP^+$ were calculated to be about $29.5\;{\mu}M$ and $63\;{\mu}M$. The recombinant shikimate dehydrogenase catalyzes the substrate in the presence of $NADP^+$ with an enzyme turnover number of $399\;s^{-1}$. Zymological studies suggest that the cloned shikimate dehydrogenase from M. tuberculosis has a pretty activity, and the work should help in the discovery of enzyme inhibitors and further of possible antimicrobial agents against Mycobacterium tuberculosis.

• Journal of Yeungnam Medical Science
• /
• 제41권2호
• /
• pp.103-112
• /
• 2024

Background: Nonalcoholic fatty liver disease (NAFLD) is characterized by an increase in hepatic triglyceride content and increased inflammatory macrophage infiltration through the C-C motif chemokine receptor (CCR) 5 pathway in the liver. DA-6034 (7-carboxymethyloxy-3',4',5-trimethoxy flavone), is a synthetic derivative of eupatilin that exhibits anti-inflammatory activity in inflammatory bowel disease. However, the effect of DA-6034 on the inflammatory response in NAFLD is not well elucidated. Therefore, we aimed to determine the effect of DA-6034 on hepatic steatosis and inflammation. Methods: Forty male C57BL/6J mice were divided into the following four groups: (1) regular diet (RD), (2) RD with DA-6034, (3) high fat diet (HFD), and (4) HFD with DA-6034. All mice were sacrificed 12 weeks after the start of the experiment. The effects of DA-6034 on macrophages were assessed using RAW 264.7 cells. Results: DA-6034 not only reduced hepatic triglyceride levels and lipid accumulation but also macrophage infiltration and proinflammatory cytokines in HFD-fed mice. According to fluorescence-activated cell sorter analysis, DA-6034 reduced the CD8⁺ T cell fraction in the liver of HFD-fed mice. DA-6034 also reduced CCR5 expression and the migration of liver macrophages in HFD-fed mice and inhibited CCR2 ligand and CCR4 ligand, which stimulated the migration of macrophages. Conclusion: Overall, DA-6034 attenuates hepatic steatosis and inflammation in obesity by regulating CCR5 expression in macrophages.

• 동의생리병리학회지
• /
• 제20권6호
• /
• pp.1636-1648
• /
• 2006

There are detailed descriptions of the clinical experiences and prescriptions of asthma in traditional Korean medicine. Zedoariae rhizoma is one of the Korean herbal medicines used to treat bronchial asthma and allergic rhinitis for centuries. However, the therapeutic mechanisms of this medication are still far from clear, In this study, a house-dust-mite (Dermatophagoides pteronyssinus [Der p])-sensitized murine model of asthma was used to evaluate the immunomodulatory effect of Zedoariae rhizoma on the allergen-induced airway inflammation in asthma. Three different protocols were designed to evaluate the treatment and/or long-term prophylacitic effect of Zedoariae rhizoma in Der p-sensitized mice. Cellular infiltration and T-cell subsets in the bronchoalveolar lavage fluid (BALF)of allergen-challenged mice were analyzed. Intrapulmonary lymphocytes were also isolated to evaluate their response to allergen stimulation. When Zedoariae rhizoma was administered to the sensitized mice before AC (groups A and C), it suppressed airway inflammation by decreasing the number of total cells and eosinophil infiltration in the BALF, and downregulated the allergen- or mitogen-induced intrapulmonary lymphocyte response of sensitized mice as compared to those of controls. This immunomodulatory effect of Zedoariae rhizoma may be exerted through the regulation of T-cell subsets by elevation or activation of the CD8+ and double-negative T-cell population in the lung. However, the administration of Zedoariae rhizoma to sensitized mice 24 h after AC (group B) did not have the same inhibitory effect on the airway inflammation as Zedoariae rhizoma given before AC. Thus, the administration of Zedoariae rhizoma before AC has the immunomodulatory effect of reducing bronchial inflammation in the allergen-sensitized mice. On the other hand, to determine the potentiality of prophylactic and/or therapeutic approaches using a traditional herbal medicine, Zedoariae rhizoma, for the control of allergic disease, we examined the effects of oral administration of Zedoariae rhizoma on a murine model of asthma allergic responses. When oral administration of Zedoariae rhizoma was begun at the induction phase immediately after OVA sensitization, eosinophilia and Th2-type cytokine production in the airway were reduced in OVA-sensitized mice following OVA inhalation. These results suggest that the oral administration of Zedoariae rhizoma dichotomously modulates allergic inflammation in murine model for asthma, thus offering a different approach for the treatment of allergic disorders.

• Clinical and Experimental Reproductive Medicine
• /
• 제44권3호
• /
• pp.152-158
• /
• 2017

Objective: To identify the associations between polymorphisms of the 3'-untranslated region (UTR) of methylenetetrahydrofolate reductase (MTHFR) gene, which codes for an important regulatory enzyme primarily involved in folate metabolism, and idiopathic recurrent pregnancy loss (RPL) in Korean women. Methods: The study population comprised 369 RPL patients and 228 controls. MTHFR 2572C > A, 4869C > G, 5488C > T, and 6685T > C 3'-UTR polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis or by TaqMan allelic discrimination assays. Natural killer cell proportions were determined by flow cytometry. Results: The MTHFR 2572-5488-6685 (A-C-T) haplotype had an adjusted odds ratio of 0.420 (95% confidence interval, 0.178-0.994; p= 0.048) for RPL. Analysis of variance revealed that MTHFR 4869C > G was associated with altered $CD56^+$ natural killer cell percentages (CC, $17.91%{\pm}8.04%$; CG, $12.67%{\pm}4.64%$; p= 0.024) and folate levels (CC, $12.01{\pm}7.18mg/mL$; CG, $22.15{\pm}26.25mg/mL$; p= 0.006). Conclusion: Variants in the 3'-UTR of MTHFR are potential biomarkers for RPL. However, these results should be validated in additional studies of ethnically diverse groups of patients.

• 한국발생생물학회지:발생과생식
• /
• 제15권4호
• /
• pp.373-383
• /
• 2011

성 호르몬과 유사한 기능을 하는 것으로 알려진 내분비교란물질은 흰쥐 흉선세포에 세포자연사를 일으켜 흉선의 기능을 감소시키는 것으로 보고되고 있으나, 그 작용 기전에 대해서는 잘 알려져 있지 않다. 따라서 본 연구에서는 내분비 교란물질 중 하나인 Tributyltin(TBT)를 흰쥐에 투여한 후 흉선의 상피세포가 지방세포로 분화되는지를 조사하고, 이로 인한 T 세포의 세포자연사와 연관성을 조사함으로써 TBT가 흉선기능에 미치는 영향을 알아보고자 하였다. 3주령 된 암컷 흰쥐에 각각 TBT 1, 10, 25 mg/kg/day를 1주일 동안 경구 투여한 후, 흉선을 획득하여 무게와 세포 수를 측정하였고, 파라핀 절편으로 H&E 염색, TUNEL 분석을 수행하였다. 또한 real-time PCR 방법으로 상피세포 표지 유전자들, 지방세포유도 유전자들과 세포자연사 관련 유전자들을 비교 분석하였으며, 유세포 분석기를 통해 세포자연사 정도를 조사하였다. 흉선의 무게와 세포 수는 대조군과 비교하여 TBT의 농도가 높을수록 유의하게 감소하였다. H&E 염색 결과, TBT의 농도가 증가할수록 흉선의 크기가 감소하고 피질과 수질의 경계가 흐려짐을 관찰하였다. TUNEL 염색 결과에서는 대조군에 비해 TBT를 투여한 군에서 세포자연사가 증가하였으며, 유세포 분석결과에서도 TBT 농도 의존적으로 세포자연사가 증가하였다. Real-time PCR 결과, 상피세포 표지 유전자인 EVA, IL-7, AIRE, KGF는 TBT의 농도가 증가할수록 발현양이 유의하게 감소한 반면, 지방세포 유도와 관련된 유전자인 $PPAR{\gamma}$, aP2, PEPCK, CD36은 TBT의 농도가 증가할수록 발현양이 유의하게 증가하였다. 세포자연사와 관련된 유전자인 $TNF{\alpha}$, TNFR1도 TBT의 농도가 증가할수록 발현양이 유의하게 증가하였다. 위의 결과를 종합하여 볼 때, 내분비교란물질인 TBT는 흉선 상피세포에 직접적으로 작용하여 지방세포로 분화 유도시킴으로써 흉선의 기능을 상실케 만들면서 T 세포의 발달에 영향을 미치는 것으로 보인다. 이러한 결과는 지속적으로 노출되는 TBT가 흉선의 기능을 떨어뜨림으로써 면역력 저하를 유발시킬 수 있음을 제시하고 있다.

• Tuberculosis and Respiratory Diseases
• /
• 제46권1호
• /
• pp.44-52
• /
• 1999

연구배경: 기관지천식은 호산구성 기도내 염증반응을 특징으로 하는데 호산구의 침윤에 관여하는 cytokine으로 T 림프구에서 분비되는 IL-3, IL-5, GM-CSF 등이 잘 알려져 있다. 한편 IL-10은 항염증성 cytokine으로 이러한 cytokine 분비를 억제할뿐만아니라, 호산구에 대해서는 직접적으로 자사(apoptosis)를 유도하고 조직내 첨착을 억제하는 기능을 갖고 있다. 본 연구에서는 기관지천식 환자에서의 기관지폐포세척액과 말초 혈액단핵세포에서 분비되는 IL-10을 정상대조군과 비교하고 기도내 염증반응정도와의 연관성을 분석하여 기관지천식에서의 IL-10 역할을 알아보고자 하였다. 방 법: 기관지천식환자 23명, 정상대조군 11명을 대상으로 기관지폐포세척액내와 말초혈액단핵구에서 분비되는 IL-10을 ELISA 방법으로 측정하고, 기도의 염증반응정도는 기관지세포세척액내 총세포수 및 호산구분율과 기관지 생검조직내 호산구 침윤정도, methacholine 기관지유발 검사에서 $PC_{20}$값으로 평가하였다. 결 과: 기관지폐포세척액내 IL-10과 말초혈액단핵구에서 분비되는 IL-10은 기관지천식 환자군과 정상대조군 사이에 통계적으로 유의한 차이는 없었다. 기관지천식환자군에서 기관지폐포세척액내 IL-10은 기관지폐포세척액내 호산구분율 및 기관지 조직내 침윤된 호산구수와는 유의한 역상관관계를 보였고, 메타콜린에 대한 PC20에 따른 차이는 없었다. 말초혈액단핵구에서 분비되는 IL-10은 기관지폐포세척액내 IL-10과 상관 관계가 없었으며, 말초혈액내 호산구수나 eosinophilic cationic protein과도 유의한 상관관계가 없었다. 결 론: 기관지천식 환자군의 기관지폐포세척액내 IL-10은 기관지폐포세척액이나 기관지 조직내 호산구 침윤과 역상관관계를 보였지만, 정상대조군과 비교해서 IL-10 감소가 관찰되지 않았기 때문에 기관지천식에서는 항염증 효과가 있는 IL-10이 중요하게 작용하지 않을 것으로 생각된다.

• IMMUNE NETWORK
• /
• 제24권2호
• /
• pp.7.1-7.19
• /
• 2024

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×10⁵ plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×10² PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×10² PFU-virus-infected lungs from 2 dpi, but not in 1×10⁵ PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×10⁵ PFU; however, 1×1² PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.