• Journal of Microbiology and Biotechnology
• /
• 제31권4호
• /
• pp.540-549
• /
• 2021

The Wnt/β-catenin signaling pathway is involved in breast cancer and Myxococcus fulvus KYC4048 is a myxobacterial strain that can produce a variety of bioactive secondary metabolites. Although a previous study revealed that KYC4048 metabolites exhibit anti-proliferative effects on breast cancer, the biochemical mechanism involved in their effects remains unclear. In the present study, KYC4048 metabolites were separated into polar and non-polar (ethyl acetate and n-hexane) fractions via liquid-liquid extraction. The effects of these polar and non-polar KYC4048 metabolites on the viability of breast cancer cells were then determined by MTT assay. Expression levels of Wnt/β-catenin pathway proteins were determined by Western blot analysis. Cell cycle and apoptosis were measured via fluorescence-activated cell sorting (FACS). The results revealed that non-polar KYC4048 metabolites induced cell death of breast cancer cells and decreased expression levels of WNT2B, β-catenin, and Wnt target genes (c-Myc and cyclin D1). Moreover, the n-hexane fraction of non-polar KYC4048 metabolites was found most effective in inducing apoptosis, necrosis, and cell cycle arrest, leading us to conclude that it can induce apoptosis of breast cancer cells through the Wnt/β-catenin pathway. These findings provide evidence that the n-hexane fraction of non-polar KYC4048 metabolites can be developed as a potential therapeutic agent for breast cancer via inhibition of the Wnt/β-catenin pathway.

• Journal of Ginseng Research
• /
• 제44권3호
• /
• pp.453-460
• /
• 2020

Background: BIOGF1K, a fraction of Panax ginseng, has desirable antimelanogenic, anti-inflammatory, and antiphotoaging properties that could be useful for treating skin conditions. Because its potential positive effects on allergic reactions in skin have not yet been described in detail, this study's main objective was to determine its efficacy in the treatment of atopic dermatitis (AD). Methods: High-performance liquid chromatography was used to verify the compounds in BIOGF1K, and we used the (3-4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide method to determine its cytotoxicity in RBL-2H3 and HMC-1 cell lines. RBL-2H3 cells were induced using both anti-DNP-IgE/DNP-BSA and calcium ionophore (A2187) treatments, whereas HMC-1 cells were induced using A2187 alone. To measure mast cell degranulation, we performed histamine (enzyme-linked immunosorbent assay) and β-hexosaminidase assays. To quantify interleukin (IL)-4, IL-5, and IL-13 levels in RBL-2H3 cells, we performed quantitative polymerase chain reaction (PCR); to quantify expression levels of IL-4 and IL-13 in HMC-1 cells, we used semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Finally, we detected the total and phosphorylated forms of extracellular signal-regulated kinase, p-38, and c-Jun N-terminal kinase proteins by immunoblotting. Results: BIOGF1K decreased the AD response by reducing both histamine and β-hexosaminidase release as well as reducing the secretion levels of IL-4, IL-5, and IL-13 in RBL-2H3 cells and IL-4 and IL-13 in HMC-1 cells. In addition, BIOGF1K decreased MAPK pathway activation in RBL-2H3 and HMC-1 cells. Conclusions: BIOGF1K attenuated the AD response, hence supporting its use as a promising and natural approach for treating AD.

• 원예과학기술지
• /
• 제29권3호
• /
• pp.165-171
• /
• 2011

식물생장억제물질의 처리는 날개하늘나리의 줄기 신장을 억제시키는데, 여기에 관여하는 식물호르몬을 찾기 위해 diniconazole의 엽면살포 후 내생 GA 및 ABA의 함량 변화를 조사하였다. 그 결과, 날개하늘나리(L. dauricum)는 $GA_1$을 활성형으로 하는 early C-13 hydroxylation($GA_{19}{\rightarrow}GA_{20}{\rightarrow}GA_1$) 경로와 $GA_4$를 활성형으로 하는 non C-13 hydroxylation(NCH, $GA_{12}{\rightarrow}GA_{24}{\rightarrow}GA_9{\rightarrow}GA_4$) 경로 모두를 가지고 있었으나, 주된 경로는 NCH 경로였다. NCH 경로의 GA 생합성은 diniconazole $50mg{\cdot}L^{-1}$ 살포에 의해 초기 단계에서부터 억제되었다. 즉 diniconazole 처리구의 $GA_{12}$ 함량은 대조구에 비해 1/17로 현저히 감소되었으며, 이러한 경향은 $GA_4$까지 계속되었다. 즉 건물 1g당 $GA_{12}$ 함량은 대조구가 213.8ng인 것에 비해, diniconazole 처리구는 12.7ng이었다. ABA의 함량도 GA에서와 같이 diniconazole 살포에 의해 1/3 수준으로 크게 감소되었다. 즉 건물 1g당 ABA 함량은 대조구 37.2ng인 것에 비해, diniconazole 처리구는 14.8ng이었다. 본 연구의 결과, 내생 $GA_4$, $GA_1$, 그리고 ABA의 함량을 고려할 때 diniconazole에 의한 날개하늘나리의 초장감소는 $GA_4$의 생합성 억제에 기인한 것으로 생각된다.

• Archives of Pharmacal Research
• /
• 제27권5호
• /
• pp.570-575
• /
• 2004

2-Hydroxymuconic semialdehyde (2-HMS) dehydrogenase catalyzes the conversion of 2-HMS to 4-oxalocrotonate, which is a step in the meta cleavage pathway of aromatic hydrocarbons in bacteria. A tomC gene that encodes 2-HMS dehydrogenase of Burkholderia cepacia G4, a soil bacterium that can grow on toluene, cresol, phenol, or benzene, was overexpressed into E. coli HB 101, and its gene product was characterized in this study. 2-HMS dehydrogenase from B. cepacia G4 has a high catalytic efficiency in terms of V$_{max}$K$_{max}$ towards 2-hydroxy-5-methyl-muconic semialdehyde followed by 2-HMS but has a very low efficiency for 5-chloro-2-hydroxymuconic semialdehyde. However, the enzyme did not utilize 2-hydroxy-6-oxo-hepta 2,4-dienoic acid and 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid as substrates. The molecular weight of 2-HMS dehydrogenase from B. cepacia G4 was predicted to be 52 kDa containing 485 amino acid residues from the nucleotide sequence of the tomC gene, and it exhibited the highest identity of 78% with the amino acid sequence of 2-HMS dehydrogenase that is encoded in the aphC gene of Comamonas testosteroni TA441. 2-HMS dehydrogenase from B. cepacia G4 showed a significant phylogenetic relationship not only with other 2-HMS dehydrogenases, but also with different dehydrogenases from evolutionarily distant organisms.sms.

• The Korean Journal of Physiology and Pharmacology
• /
• 제2권3호
• /
• pp.297-305
• /
• 1998

This study used in vivo intracellular recording in rat hippocampus to evaluate the effect of lidocaine and MK-801 on the membrane properties and the synaptic responses of individual neurons to electrical stimulation of the commissural pathway. Cells in control group typically fired in a tonic discharge mode with an average firing frequency of $2.4{\pm}0.9$ Hz. Neuron in MK-801 treated group (0.2 mg/kg, i.p.) had an average input resistance of $3.28{\pm}5.7\;M{\Omega}$ and a membrane time constant of $7.4{\pm}1.8$ ms. These neurons exhibited $2.4{\pm}0.2$ ms spike durations, which were similar to the average spike duration recorded in the neurons of the control group. Slightly less than half of these neurons were firing spontaneously with an average discharge rate of $2.4{\pm}1.1$ Hz. The average peak amplitude of the AHP following the spikes in these groups was $7.4{\pm}0.6$ mV with respect to the resting membrane potential. Cells in MK-801 and lidocaine treated group (5 mg/kg, i.c.v.) had an average input resistance of $3.45{\pm}6.0\;M{\Omega}$ and an average time constant of $8.0{\pm}1.4$ ms. The cells were firing spontaneously at an average discharge rate of $0.6{\pm}0.4$ Hz. Upon depolarization of the membrane by 0.8 nA for 400 ms, all of the tested cells exhibited accommodation of spike discharge. The most common synaptic response contained an EPSP followed by early-IPSP and late-IPSP. Analysis of the voltage dependence revealed that the early-IPSP and late-IPSP were putative $Cl^--and\;K^+-dependent$, respectively. Systemic injection of the NMDA receptor blocker, MK-801, did not block synaptic responses to the stimulation of the commissural pathway. No significant modifications of EPSP, early-IPSP, or late-IPSP components were detected in the MK-801 and/or lidocaine treated group. These results suggest that MK-801 and lidocaine manifest their CNS effects through firing pattern of hippocampal pyramidal cells and neural network pattern by changing the synaptic efficacy and cellular membrane properties.

• The Korean Journal of Physiology and Pharmacology
• /
• 제4권5호
• /
• pp.369-378
• /
• 2000

This study was undertaken to investigate an involvement of nitroxergic innervation in gastric smooth muscle of rat. Isometric tension study, the measurement of single cell length, NADPH diaphorase stain of smooth muscle layers and neuronal nitric oxide synthase (nNOS) western blotting were performed. Sodium nitroprusside (SNP), a nitric oxide donor, relaxed the muscle strips precontracted by acetylcholine (ACh) in a concentration-dependent manner. Pretreatment of L-arginine decreased the contraction induced by electric field stimulation (EFS). Pretreatment of $N^G-nitro-L-arginine$ methyl ester (L-NAME), a NOS inhibitor, increased the EFS-induced contractions. LY 83583, a guanylate cyclase (GC) inhibitor, reversed the inhibitory actions of L-arginine on the muscle contractions. The effects of L-Arginine, L-NAME and LY 83583 on ACh-induced contractions were not significant. L-arginine reduced the EFS-induced contraction in circular muscle, whereas L-NAME enhanced the EFS-induced contraction in longitudinal strips. By EFS, the phasic contractions appeared approximately $20{\sim}25$ seconds later. L-NAME significantly shortened the delay time to about $2{\sim}3$ seconds. In single cell study, ACh contracted gastric smooth muscle cells, SNP relaxed the cells, and the latter also inhibited the ACh-induced contraction. LY 83583 enhanced the ACh-induced contraction and antagonized SNP-induced relaxation. NADPH diaphorase activity was assessed by a histochemistry, nitroblue tetrazolium (NTB) staining. Positive staining was observed in both circular and longitudinal muscle layers. L-arginine increased the staining, while L-NAME decreased the staining. Western blotting for nNOS proved the presence of nNOS in rat gastric smooth muscle. EFS and additional $Ca^{2+}$ increased nNOS protein expression. These results suggest that in rat stomach, both circular and longitudinal muscle layers are innervated with nitroxergic nerves which relax the gastric smooth muscle via NO-cGMP pathway.

• 한국미생물학회:학술대회논문집
• /
• 한국미생물학회 2007년도 International Meeting of the Microbiological Society of Korea
• /
• pp.120-122
• /
• 2007

All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.

• 대한기계학회논문집 C: 기술과 교육
• /
• 제3권4호
• /
• pp.307-312
• /
• 2015

탑승교는 여객터미널청사에서 항공기 출입구 사이를 이어주는 이동통로를 탑승객에게 제공하는 공항 편의시설 중 하나다. 본 연구에서는 유한요소 해석법을 이용하여 탑승교 설계시 리프트 컬럼의 배치설계가 탑승교 구조물의 처짐 및 응력상태에 미치는 영향 비교 검토하였다. 그 결과 탑승교 터널 프레임의 중첩구간에서 최대응력이 발생함을 확인하였고, 리프트 컬럼 배치설계와 그 값의 크기가 매우 밀접한 관계를 갖고 있음을 확인하였다.

• 동의생리병리학회지
• /
• 제19권3호
• /
• pp.797-801
• /
• 2005

While conducting an in vitro screening of various medicinal plant extracts, an aqueous extract of Rosa rugosa Radix (ARR) was found to exhibit a distinct vasorelaxant activity. ARR induced a concentration-dependent relaxation of the phenylephrine-precontracted aorta. This effect disappeared with the removal of functional endothelium. Pretreatment of the aortic tissues with NG-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]-oxadiazole-[4,3-]-quinoxalin-1-one (ODQ) completely inhibited the relaxation induced by ARR. ARR-induced vascular relaxations were also markedly attenuated by addition of diltiazem or verapamil. However, the relaxant effect of ARR was not blocked by pretreatment with indomethacine, tetraethylammonium (TEA), glibenclamide, atropine, or propranolol. Taken together, the present study suggests that ARR dilates vascular smooth muscle via endothelium-dependent NO/cGMP signaling.

• The Korean Journal of Ecology
• /
• 제8권3호
• /
• pp.127-132
• /
• 1985

In this study, the competitive development of leaf in Amaranthus and Chenopodium were invesitgated by the complemented plastochron index. The value of PI for Amaranthus was not varied with competional ratios, while for Chenopodium it was varied. Namely in Chenopodium, the plastochron 1 was increased as competitional combinations, the plastochron 2 was decreased. These results indicated Amaranthus had advantage in competition over Chenopodium. It is surmised that these results were exhibited differences in photosynthetic pathway between Amaranthus (C4 plant) and Chenopodium (C3 plant). The linear patterns were clearly demonstrated by the differences in leaf arrangement between Amaranthus (alternate type) and Chenopodium (opposite type). From these resultss, use of plastochron seems to a useful means of evaluating plat response to various environments.