The Roles of Two hfq Genes in the Virulence and Stress Resistance of Burkholderia glumae

Kim, Jieun,Mannaa, Mohamed,Kim, Namgyu,Lee, Chaeyeong,Kim, Juyun,Park, Jungwook,Lee, Hyun-Hee,Seo, Young-Su The Korean Society of Plant Pathology 2018 Plant Pathology Journal Vol.34 No.5

The Hfq protein is a global small RNA chaperone that interacts with regulatory bacterial small RNAs (sRNA) and plays a role in the post-transcriptional regulation of gene expression. The roles of Hfq in the virulence and pathogenicity of several infectious bacteria have been reported. This study was conducted to elucidate the functions of two hfq genes in Burkholderia glumae, a causal agent of rice grain rot. Therefore, mutant strains of the rice-pathogenic B. glumae BGR1, targeting each of the two hfq genes, as well as the double defective mutant were constructed and tested for several phenotypic characteristics. Bacterial swarming motility, toxoflavin production, virulence in rice, siderophore production, sensitivity to $H_2O_2$, and lipase production assays were conducted to compare the mutant strains with the wild-type B. glumae BGR1 and complementation strains. The hfq1 gene showed more influence on bacterial motility and toxoflavin production than the hfq2 gene. Both genes were involved in the full virulence of B. glumae in rice plants. Other biochemical characteristics such as siderophore production and sensitivity to $H_2O_2$ induced oxidative stress were also found to be regulated by the hfq1 gene. However, lipase activity was shown to be unassociated with both tested genes. To the best of our knowledge, this is the first study to elucidate the functions of two hfq genes in B. glumae. Identification of virulence-related factors in B. glumae will facilitate the development of efficient control measures.

Stress Tolerance and Virulence-Related Roles of Lipopolysaccharide in Burkholderia glumae

Chaeyeong Lee,Mohamed Mannaa,Namgyu Kim,Juyun Kim,Yeounju Choi,Soo Hyun Kim,Boknam Jung,Hyun-Hee Lee,Jungkwan Lee,Young-Su Seo 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.5

The lipopolysaccharide (LPS) composed of lipid A, core, and O-antigen is the fundamental constituent of the outer membrane in gram-negative bacteria. This study was conducted to investigate the roles of LPS in Burkholderia glumae, the phytopathogen causing bacterial panicle blight and seedling rot in rice. To study the roles of the core oligosaccharide (OS) and the Oantigen region, mutant strains targeting the waaC and the wbiFGHI genes were generated. The LPS profile was greatly affected by disruption of the waaC gene and slight reductions were observed in the O-antigen region following wbiFGHI deletions. The results indicated that disruption in the core OS biosynthesis-related gene, waaC, was associated with increased sensitivity to environmental stress conditions including acidic, osmotic, saline, and detergent stress, and to polymyxin B. Moreover, significant impairment in the swimming and swarming motility and attenuation of bacterial virulence to rice were also observed in the waaC-defective mutant. The motility and virulence of O-antigen mutants defective in any gene of the wbiFGHI operon, were not significantly different from the wild-type except in slight decrease in swimming and swarming motility with wbiH deletion. Altogether, the results of present study indicated that the LPS, particularly the core OS region, is required for tolerance to environmental stress and full virulence in B. glumae. To our knowledge, this is the first functional study of LPS in a plant pathogenic Burkholderia sp. and presents a step forward toward full understanding of B. glumae pathogenesis.

Scavenger receptor class F member 2 (SCARF2) as a novel therapeutic target in glioblastoma

Kim Chaeyeong,Kong Gyeyeong,Lee Hyunji,Tran Quangdon,Vo Thuy-Trang T.,Kwon So Hee,Park Jisoo,Kim Seon-Hwan,Park Jongsun 한국독성학회 2022 Toxicological Research Vol.38 No.2

Scavenger receptor class F member 2 (SCARF2) is expressed by endothelial cells with very large cytoplasmic domains and is the second isotype, also known as scavenger receptor expressed by endothelial cells 2 (SREC-2). SREC-1 plays an important role in the binding and endocytosis of various endogenous and exogenous ligands. Many studies have been carried out on modified low-density lipoprotein internalization activity, but there have been few studies on SCARF2. Higher expression of SCARF2 has been found in glioblastoma (GBM) than normal brain tissue. Through analysis of The Cancer Genome Atlas database, it was confirmed that SCARF2 is widely expressed in GBM, and increased SCARF2 expression correlated with a poor prognosis in patients with glioma. The results of this study showed that the expression of SCARF2 is increased in GBM cell lines and patients, suggesting that SCARF2 may be a potential diagnostic marker and therapeutic molecule for cancers including glioma.

The Roles of Two hfq Genes in the Virulence and Stress Resistance of Burkholderia glumae

Jieun Kim,Mohamed Mannaa,Namgyu Kim,Chaeyeong Lee,Juyun Kim,Jungwook Park,Hyun-Hee Lee,Young-Su Seo 한국식물병리학회 2018 Plant Pathology Journal Vol.34 No.5

The Hfq protein is a global small RNA chaperone that interacts with regulatory bacterial small RNAs (sRNA) and plays a role in the post-transcriptional regulation of gene expression. The roles of Hfq in the virulence and pathogenicity of several infectious bacteria have been reported. This study was conducted to elucidate the functions of two hfq genes in Burkholderia glumae, a causal agent of rice grain rot. Therefore, mutant strains of the rice-pathogenic B. glumae BGR1, targeting each of the two hfq genes, as well as the double defective mutant were constructed and tested for several phenotypic characteristics. Bacterial swarming motility, toxoflavin production, virulence in rice, siderophore production, sensitivity to H2O2, and lipase production assays were conducted to compare the mutant strains with the wildtype B. glumae BGR1 and complementation strains. The hfq1 gene showed more influence on bacterial motility and toxoflavin production than the hfq2 gene. Both genes were involved in the full virulence of B. glumae in rice plants. Other biochemical characteristics such as siderophore production and sensitivity to H2O2 induced oxidative stress were also found to be regulated by the hfq1 gene. However, lipase activity was shown to be unassociated with both tested genes. To the best of our knowledge, this is the first study to elucidate the functions of two hfq genes in B. glumae. Identification of virulence-related factors in B. glumae will facilitate the development of efficient control measures.

Stress Tolerance and Virulence-Related Roles of Lipopolysaccharide in Burkholderia glumae

Lee, Chaeyeong,Mannaa, Mohamed,Kim, Namgyu,Kim, Juyun,Choi, Yeounju,Kim, Soo Hyun,Jung, Boknam,Lee, Hyun-Hee,Lee, Jungkwan,Seo, Young-Su The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.5

The lipopolysaccharide (LPS) composed of lipid A, core, and O-antigen is the fundamental constituent of the outer membrane in gram-negative bacteria. This study was conducted to investigate the roles of LPS in Burkholderia glumae, the phytopathogen causing bacterial panicle blight and seedling rot in rice. To study the roles of the core oligosaccharide (OS) and the O-antigen region, mutant strains targeting the waaC and the wbiFGHI genes were generated. The LPS profile was greatly affected by disruption of the waaC gene and slight reductions were observed in the O-antigen region following wbiFGHI deletions. The results indicated that disruption in the core OS biosynthesis-related gene, waaC, was associated with increased sensitivity to environmental stress conditions including acidic, osmotic, saline, and detergent stress, and to polymyxin B. Moreover, significant impairment in the swimming and swarming motility and attenuation of bacterial virulence to rice were also observed in the waaC-defective mutant. The motility and virulence of O-antigen mutants defective in any gene of the wbiFGHI operon, were not significantly different from the wild-type except in slight decrease in swimming and swarming motility with wbiH deletion. Altogether, the results of present study indicated that the LPS, particularly the core OS region, is required for tolerance to environmental stress and full virulence in B. glumae. To our knowledge, this is the first functional study of LPS in a plant pathogenic Burkholderia sp. and presents a step forward toward full understanding of B. glumae pathogenesis.

수축 및 확장 변위증폭기구가 적용된 새로운 형태의 선형 액추에이터의 설계 및 성능 평가

김재진(Jaejin Kim),조예린(Yehrin Jo),박채영(Chaeyeong Bak),김용대(Yongdae Kim) 항공우주시스템공학회 2018 항공우주시스템공학회 학술대회 발표집 Vol.2018 No.11

본 논문에서는 박막히터를 이용하여 내부 구조물을 가열함으로써 길이 방향 변위가 증폭되는 새로운 형태의 수축 및 확장형 액추에이터 설계안을 제안하였다. 바 형태의 내부 구조물을 가열하여 외부의 다이아몬드 구조물의 변형량을 증폭시키는 수축형 액추에이터와 다이아몬드 모양의 내부 구조물을 직접 가열함으로써 변위를 증폭시킬 있는 확장형 액추에이터를 고안하였으며, 각 액추에이터에 대해 FEM 해석툴을 이용하여 세부설계를 수행하였다. 이후 복잡한 구조물도 쉽게 구현이 가능한 3D 프린터를 이용해 제작하였다. 액추에이터 소재는 열팽률이 크고 연속 사용 온도가 높은 폴리아미드 (polyamide)를 사용하였다. 각 액추에이터에 대해 입력 전력량 별 작동 변위를 측정하고 FEM 해설결과와 비교를 하였다.

Myristoylated TMEM39AS41, a cell‑permeable peptide, causes lung cancer cell death

Sungjin Park,Minhee Kim,Youngeun Hong,Hyunji Lee,Quangdon Tran,Chaeyeong Kim,So Hee Kwon,Jisoo Park,Jongsun Park,Seon‑Hwan Kim 한국독성학회 2020 Toxicological Research Vol.36 No.2

Lung cancer is the most common cause of cancer-associated death worldwide. Most patients with non-small cell lung cancer die within several years of the initial diagnosis, and new therapies are desperately needed. Transmembrane protein (TMEM) 39AS41, a synthetic peptide, was generated from the protein kinase B substrate motif 34GLRNRNGSAIGLPVP48 found in the human TMEM39A protein. Myristic acid was conjugated to the N-terminus of the peptide to confer cell permeability. In this study, we found that in vitro TMEM39AS41 peptide led to cell death via inhibition of inflammation/autophagy pathways in KRAS-mutated cell and tissues. In addition, TMEM39A, at a dose of 30 mg/kg, significantly suppressed tumor growth in KRASLA1 non-small cell lung cancer mice. These results suggest that the TMEM39AS41 peptide could have therapeutic potential for lung cancer.

지반 거동 변형 예측을 위한 3D 모델링과 계측 데이터의 합성

김정우(Jung Woo Kim),정현주(Hyunju Jeong),박하은(Haeun Park),이다연(Da Yeoun Lee),허채영(Chaeyeong Hur),김태식(Taesik Kim) 대한토목학회 2018 대한토목학회 학술대회 Vol.2018 No.10

AXL is required for hypoxia-mediated hypoxia-inducible factor-1 alpha function in glioblastoma

Vo Thuy-Trang T.,Tran Quangdon,Hong Youngeun,Lee Hyunji,Cho Hyeonjeong,Kim Minhee,Park Sungjin,Kim Chaeyeong,Bayarmunkh Choinyam,Boldbaatar Damdindorj,Kwon So Hee,Park Jisoo,Kim Seon-Hwan,Park Jongsun 한국독성학회 2023 Toxicological Research Vol.39 No.4

Glioblastoma (GBM) is the most aggressive type of central nervous system tumor. Molecular targeting may be important when developing efficient GBM treatment strategies. Sequencing of GBMs revealed that the receptor tyrosine kinase (RTK)/ RAS/phosphatidylinositol-3-kinase pathway was altered in 88% of samples. Interestingly, AXL, a member of RTK, was proposed as a promising target in glioma therapy. However, the molecular mechanism of AXL modulation of GBM genesis and proliferation is still unclear. In this study, we investigated the expression and localization of hypoxia-inducible factor-1 alpha (HIF-1α) by AXL in GBM. Both AXL mRNA and protein are overexpressed in GBM. Short-interfering RNA knockdown of AXL in U251-MG cells reduced viability and migration. However, serum withdrawal reduced AXL expression, abolishing the effect on viability. AXL is also involved in hypoxia regulation. In hypoxic conditions, the reduction of AXL decreased the level and nuclear localization of HIF-1α. The co-expression of HIF-1α and AXL was found in human GBM samples but not normal tissue. This finding suggests a mechanism for GBM proliferation and indicates that targeting AXL may be a potential GBM therapeutic.

개 파보바이러스와 코로나바이러스 진단을 위한 신속진단키트의 임상적 유용성

Chaeyeong MIN,Won-Shik KIM,Chom-Kyu CHONG,Yong LIM 대한임상검사과학회 2023 대한임상검사과학회지(KJCLS) Vol.55 No.1

개 파보바이러스(canine parvovirus type 2, CPV-2)와 코로나바이러스(canine coronavirus, CCoV)는 개에서 위장관염을 일으키는 주요 병원체이다. 두 바이러스는 전염성과 이환율이 높고 특정한 치료법이 없어 신속 정확한 진단이 필요하다. 동물용 신속진단키트 (rapid diagnostic test, RDT)는 빠르고, 간편하여 진료현장에서 널리 활용되고 있다. 이에 본 연구에서는 성능평가를 통해 CPV-2/CCoV RDT의 임상적 유용성을 확인하고자 하였다. 성능평가 항목으로 최소검출한계(limit of detection, LoD), 교차반응, 간섭, 민감도, 특이도, 음성우도비(negative likelihood ratio, NLR), 카파통계량(kappa value, κ) 등을 확인하였다. 성능평가 결과, LoD는 CPV-2 9.7×10 50% tissue culture infections dose (TCID50)/mL, CCoV 2.5×102 TCID50/mL로 나타났다. 병원체 9종에 의한 교차반응과 간섭물질에 대한 간섭은 관찰되지 않았다. RDT는 두 바이러스의 검출에 있어 민감도 90.0%, 특이도 100.0%, NLR=0.1, κ=0.90으로 나타났다. 결론적으로 CPV-2/CCoV RDT는 높은 민감도, 특이도, κ와 낮은 NLR을 보여 선별검사로써 유용할 것으로 생각된다.