Evolutionary processes of melanomas from giant congenital melanocytic nevi

Melanoma can develop in a congenital melanocytic nevus (CMN). In fact, a large CMN is associated with a high risk of developing melanoma. Although melanomas arising from CMNs are thought to have a pathogenesis distinct from conventional melanomas, no studies have been conducted on the evolution or tumor heterogeneity of CMN melanomas. We applied multi‐region whole‐exome sequencing to investigate the clonal nature of driver events and evolutionary processes in CMNs and melanomas arising from CMNs. In two patients, we observed an independent subclonal evolution in cancerized fields of CMNs and chromosome 8q amplification in both melanomas arising from CMNs. The amplification of MYC, located in chromosome 8q, was correlated with the percentage of tumor cells expressing high levels of MYC protein detected in melanoma cells by immunohistochemistry. Our analysis suggests that each CMN cell may evolve sporadically and that amplification of MYC might be a key event for melanoma development in CMNs.     

Bacillus subtilis strain L1 promotes nitrate reductase activity in Arabidopsis and elicits enhanced growth performance in Arabidopsis,lettuce, and wheat

Journal of Plant Research - Plant growth promoting rhizobacteria (PGPR) are a group of bacteria that promote plants growth in the rhizosphere. PGPRs are involved in various mechanisms that...     

Insecticidal and insect growth regulatory activities of secondary metabolites from entomopathogenic fungi,Lecanicillium attenuatum

Insect growth regulators (IGRs) are effective alternatives to chemical insecticides because of their specificity and low environmental toxicity. Entomopathogenic fungi are an important natural pathogen of insects and have been developed as biological control agents. They produce a wide range of secondary metabolites such as antibiotics, pesticides, growth-promoting or inhibiting compounds and insect attracting agents. In this study, to explore novel IGR substances from entomopathogenic fungi, culture extracts of 189 entomopathogenic fungi isolated from Korean soil samples were investigated for their juvenile hormone (JH)-based IGR activities. Whereas none of the culture extracts exhibited JH agonist (JHA) activity, 14 extracts showed high levels of JH antagonist (JHAN) activity. Among them, culture extract of JEF-145 strain, which was identified as Lecanicillium attenuatum, showed the highest insecticidal against Aedes albopictus and Plutella xylostella. At liquid culture condition, JHAN activity was observed in culture soup rather than mycelial cake, indicating that substances with JHAN activity are released from the JEF-145 strain during culture. Furthermore, while extract from solid cultured JEF-145 strain showed insecticidal activities against both A. albopictus and P. xylostella, that from liquid cultured fungi showed insecticidal activity only against A. albopictus, indicating that L. attenuatum JEF-145 strain produces different kinds of secondary metabolites with JHAN activity depending on culture conditions. These results suggested that JHAN substances derived from entomopathogenic fungi could be usefully exploited to develop novel eco-friendly IGR insecticides.     

Arabidopsis RING E3 ubiquitin ligase JUL1 participates in ABA‐mediated microtubule depolymerization,stomatal closure,and tolerance response to drought stress

Ubiquitination is a critical post‐translational protein modification that has been implicated in diverse cellular processes, including abiotic stress responses, in plants. In the present study, we identified and characterized a T‐DNA insertion mutant in the At5g10650 locus. Compared to wild‐type Arabidopsis plants, at5g10650 progeny were hyposensitive to ABA at the germination stage. At5g10650 possessed a single C‐terminal C3HC4‐type Really Interesting New Gene (RING) motif, which was essential for ABA‐mediated germination and E3 ligase activity in vitro. At5g10650 was closely associated with microtubules and microtubule‐associated proteins in Arabidopsis and tobacco leaf cells. Localization of At5g10650 to the nucleus was frequently observed. Unexpectedly, At5g10650 was identified as JAV1‐ASSOCIATED UBIQUITIN LIGASE1 (JUL1), which was recently reported to participate in the jasmonate signaling pathway. The jul1 knockout plants exhibited impaired ABA‐promoted stomatal closure. In addition, stomatal closure could not be induced by hydrogen peroxide and calcium in jul1 plants. jul1 guard cells accumulated wild‐type levels of H₂O₂ after ABA treatment. These findings indicated that JUL1 acts downstream of H₂O₂ and calcium in the ABA‐mediated stomatal closure pathway. Typical radial arrays of microtubules were maintained in jul1 guard cells after exposure to ABA, H₂O₂, and calcium, which in turn resulted in ABA‐hyposensitive stomatal movements. Finally, jul1 plants were markedly more susceptible to drought stress than wild‐type plants. Overall, our results suggest that the Arabidopsis RING E3 ligase JUL1 plays a critical role in ABA‐mediated microtubule disorganization, stomatal closure, and tolerance to drought stress.     

Human recombinant IL-10 reduces xenogenic cytotoxicity via macrophage M2 polarization

Xenotransplantation has been considered an alternative to the moderate shortage of donor organs for transplantation. To achieve successful xenotransplatation, there is the need to overcome immune rejection. Although, hyperacute rejection has been overcome by α1,3-galactosyltransferase knockout pig, cellular immune rejection remains as a subsequent barrier. Interleukin-10 (IL-10) is known as an anti-inflammatory and immunomodulatory cytokine which has been shown to limit inflammatory responses by inhibiting macrophage activation in several animal experiments. To study the effect of human IL-10 (hIL-10) on pig-to-human xenotransplantation, porcine kidney epithelial cell line (PK(15)) expressing hIL-10 was established. The cytotoxicity of macrophages decreased by hIL-10 from transgenic cells. Furthermore, there is a decreased production of pro-inflammatory cytokines, tumor necrosis factor-α and interleukin-23, and increased anti-inflammatory cytokines like IL-10, but not transforming growth factor beta, in the presence of hIL-10. Also, macrophage polarization toward M2-like phenotype were induced by hIL-10 from transgenic PK(15) cells. Finally, we suggest that the cytotoxicity of human macrophages was reduced by hIL-10 from transgenic cells, inducing M2-like macrophage polarization. Therefore, these results show that hIL-10 transgenic pig can be used as a model to overcome acute immune rejection in pig-to-human xenotransplantation.     

Study of the independent gametophytes found on Jeju Island in South Korea and the first record of the obligate independent gametophyte of Antrophyum obovatum Baker

Fern gametophytes have often been neglected in research; however, studies on gametophytes are crucial for a better understanding of the evolution of ferns. During their life cycle, some gametophytes produce large and long‐lived populations without producing sporophytes and reproduce independently through asexual means, such as through the formation of gemmae. In this study, we investigated independent gametophytes on the Jeju Island of Korea, which was located on the land bridge between East China and Japan during the glacial periods. Fourteen gametophyte populations were collected from seven sites, of which 13 populations were clearly identified as belonging to four fern species known to occur in Jeju Island with BLAST searches using rbcL and trnL‐F sequences. Surprisingly, the last remaining population constituted undescribed taxa in Korea. We presented the first report of the independent gametophytes of Antrophyum obovatum Baker which has not been previously recorded in Korea. It has been supposed that many ferns sought suitable habitat throughout the land bridge between China and Japan. However, Jeju Island might be unsuitable for vittarioid ferns that prefer a tropical or subtropical environment. Consequently, only two species of vittariod ferns (A. obovatum and Haplopteris flexuosa (Fée) E.H. Crane) in the form of a gametophyte and sporophyte, respectively, exist on Jeju Island. Therefore, this gametophyte population must be protected and managed from a conservation perspective. In the case of the independent gametophyte of Hymenophyllum wrightii Bosch, haplotype analysis was conducted based on the rbcL sequences and the result supported that the North American populations were migrated from Japan through land bridge during the glacial periods and Jeju populations were recently established by long‐distance dispersal of the Japanese populations.     

Serum biomarker discovery related to pathogenesis in acute coronary syndrome by proteomic approach

Acute coronary syndrome (ACS) results from inadequate supply of blood flow from the coronary arteries to the heart or ischemia. ACS has an extremely high morbidity and mortality. The levels of biomarkers currently used for detection of ACS also increase in response to myocardial necrosis and other diseases and are not elevated immediately after symptoms appear, thus limiting their diagnostic capacity. Therefore, we aimed to discover new ACS diagnostic biomarkers with high sensitivity and specificity that are specifically related to ACS pathogenesis. Sera from 50 patients with ACS and healthy controls (discovery cohort) each were analyzed using mass spectrometry (MS) to identify differentially expressed proteins, and protein candidates were evaluated as ACS biomarkers in 120 people in each group (validation cohort). α-1-acid glycoprotein 1 (AGP1), complement C5 (C5), leucine-rich α-2-glycoprotein (LRG), and vitronectin (VN) were identified as biomarkers whose levels increase and gelsolin (GSN) as a biomarker whose levels decrease in patients with ACS. We concluded that these biomarkers are associated with the pathogenesis of ACS and can predict the onset of ACS prior to the appearance of necrotic biomarkers.     

Adhaeribacter soli sp. nov., a bacterium isolated from soil in Korea

Archives of Microbiology - Strain MA2T was isolated from a soil sample from Gijang-gun, Busan in Korea. The strain, a Gram-stain-negative aerobic bacterium, is non-motile, ovoid- or rod-shaped,...