• 한국미생물·생명공학회지
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• 제50권1호
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• pp.126-134
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• 2022

Norovirus (NoV) is an important pathogen causing acute gastroenteritis worldwide. The purpose of the present study was the molecular characterization of NoV. A total of 408 stool specimens collected from hospitalized children associated with acute gastroenteritis in Chiang Rai, Thailand, 2015-2017 were investigated for the presence of NoVs by RT-PCR. NoV GII was detected in 32 samples (7.8%). Five distinct genotypes were identified, including GII.4 (13/32, 40.6%), GII.3 (11/32, 34.3%), GII.17 (4/32, 12.5%), GII.2 (2/32, 6.3%), and GII.14 (2/32, 6.3%). NoV infection occurred mostly in young children under 3 years of age (31/32, 96.9%) and showed the main peak in summer months from March to April (18/32, 56.3%). Phylogenetic analysis revealed that all 13 GII.4 strains clustered with GII.4 Sydney 2012 variant. Representative GII.3 strains were analyzed as a recombinant GII.3P[12] strain. Several amino acid differences were found in the antigenic epitopes and antibody binding sites of the VP1 capsid of the GII.3P[12]. Homology modeling of the P domain of the GII.3P[12] strain demonstrated that 10/13 amino acid differences were predicted to be located on the surface-exposed area of the capsid structure. These amino acid changes might affect the infectivity and the antigenicity of the recombinant GII.3P[12]. The prevalence of GII.4 Sydney 2012 and recombinant GII.3P[12] strains indicates the genetic diversity of circulating NoVs in Thailand, emphazing the importance of continuous surveillance to mornitor newly emerging NoV strains in the future.

• BMB Reports
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• 제55권3호
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• pp.142-147
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• 2022

Human pluripotent stem cells (PSCs) have been utilized as a promising source in regenerative medicine. However, the risk of teratoma formation that comes with residual undifferentiated PSCs in differentiated cell populations is most concerning in the clinical use of PSC derivatives. Here, we report that a monoclonal antibody (mAb) targeting PSCs could distinguish undifferentiated PSCs, with potential teratoma-forming activity, from differentiated PSC progeny. A panel of hybridomas generated from mouse immunization with H9 human embryonic stem cells (hESCs) was screened for ESC-specific binding using flow cytometry. A novel mAb, K312, was selected considering its high stem cell-binding activity, and this mAb could bind to several human induced pluripotent stem cells and PSC lines. Cell-binding activity of K312 was markedly decreased as hESCs were differentiated into embryoid bodies or by retinoic acid treatment. In addition, a cell population negatively isolated from undifferentiated or differentiated H9 hESCs via K312 targeting showed a significantly reduced expression of pluripotency markers, including Oct4 and Nanog. Furthermore, K312-based depletion of pluripotent cells from differentiated PSC progeny completely prevented teratoma formation. Therefore, our findings suggest that K312 is utilizable in improving stem cell transplantation safety by specifically distinguishing residual undifferentiated PSCs.

• Molecules and Cells
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• 제45권7호
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• pp.479-494
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• 2022

Human mesenchymal stem cells (MSCs) are multipotent stem cells that have been intensively studied as therapeutic tools for a variety of disorders. To enhance the efficacy of MSCs, therapeutic genes are introduced using retroviral and lentiviral vectors. However, serious adverse events (SAEs) such as tumorigenesis can be induced by insertional mutagenesis. We generated lentiviral vectors encoding the wild-type herpes simplex virus thymidine kinase (HSV-TK) gene and a gene containing a point mutation that results in an alanine to histidine substitution at residue 168 (TK(A168H)) and transduced expression in MSCs (MSC-TK and MSC-TK(A168H)). Transduction of lentiviral vectors encoding the TK(A168H) mutant did not alter the proliferation capacity, mesodermal differentiation potential, or surface antigenicity of MSCs. The MSC-TK(A168H) cells were genetically stable, as shown by karyotyping. MSC-TK(A168H) responded to ganciclovir (GCV) with an half maximal inhibitory concentration (IC₅₀) value 10-fold less than that of MSC-TK. Because MSC-TK(A168H) cells were found to be non-tumorigenic, a U87-TK(A168H) subcutaneous tumor was used as a SAE-like condition and we evaluated the effect of valganciclovir (vGCV), an oral prodrug for GCV. U87-TK(A168H) tumors were more efficiently ablated by 200 mg/kg vGCV than U87-TK tumors. These results indicate that MSC-TK(A168H) cells appear to be pre-clinically safe for therapeutic use. We propose that genetic modification with HSV-TK(A168H) makes allogeneic MSC-based ex vivo therapy safer by eliminating transplanted cells during SAEs such as uncontrolled cell proliferation.

• Journal of Ginseng Research
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• 제46권5호
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• pp.700-709
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• 2022

Background: Ginsenoside Rd is a natural compound with promising neuroprotective effects. However, the underlying mechanisms are still not well-understood. In this study, we explored whether ginsenoside Rd exerts protective effects on cerebral endothelial cells after oxygen-glucose deprivation/reoxygenation (OGD/R) treatment and its potential docking proteins related to the underlying regulations. Method: Commercially available primary human brain microvessel endothelial cells (HBMECs) were used for in vitro OGD/R studies. Cell viability, pyroptosis-associated protein expression and tight junction protein degradation were evaluated. Molecular docking proteins were predicted. Subsequent surface plasmon resonance (SPR) technology was utilized for validation. Flow cytometry was performed to quantify caspase-1 positive and PI positive (caspase-1+/PI+) pyroptotic cells. Results: Ginsenoside Rd treatment attenuated OGD/R-induced damage of blood-brain barrier (BBB) integrity in vitro. It suppressed NLRP3 inflammasome activation (increased expression of NLRP3, cleaved caspase-1, IL-1β and GSDMD-N terminal (NT)) and subsequent cellular pyroptosis (caspase-1+/PI + cells). Ginsenoside Rd interacted with SLC5A1 with a high affinity and reduced OGD/R-induced sodium influx and potassium efflux in HBMECs. Inhibiting SLC5A1 using phlorizin suppressed OGD/R-activated NLRP3 inflammasome and pyroptosis in HBMECs. Conclusion: Ginsenoside Rd protects HBMECs from OGD/R-induced injury partially via binding to SLC5A1, reducing OGD/R-induced sodium influx and potassium efflux, thereby alleviating NLRP3 inflammasome activation and pyroptosis.

• Parasites, Hosts and Diseases
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• 제60권2호
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• pp.127-131
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• 2022

Feline hemotropic mycoplasmosis (hemoplasmosis) is an infection of the red blood cells caused by the Mycoplasma haemofelis (Mhf), Candidatus Mycoplasma haemominutum (CMhm), and Candidatus Mycoplasma turicensis (CMt). The existence of Mhf, CMhm, and CMt has been demonstrated in feral cats in Korea using molecular methods, but no clinical cases have yet been reported. This study reports 2 clinical cases of hemotropic mycoplasmosis caused by CMhm and CMt in 2 anemic cats. The first case was a client-owned intact female domestic shorthair cat that presented with fever, pale mucous membranes, and normocytic normochromic non-regenerative anemia. Prior to referral, an immunosuppressive prednisolone dose was administered at the local veterinary clinic for 1 month. The cat was diagnosed with high-grade alimentary lymphoma. Organisms were found on the surface of the red blood cells on blood smear examination. The second case was of a rescued cat that presented with dehydration and fever. The cat had normocytic normochromic non-regenerative anemia. Necropsy revealed concurrent feline infectious peritonitis. Polymerase chain reaction assay targeting 16S rRNA revealed CMhm infection in case 1 and dual infection of CMhm and CMt in case 2. Normocytic normochromic non-regenerative anemia was observed in both cats before and during the management of the systemic inflammation. This is the first clinical case report in Korea to demonstrate CMhm and CMt infections in symptomatic cats.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.226-237
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• 2022

Arcuospathidium is a haptorian ciliate genus composed of 18 species, and only one species has been reported in Korea. Here, we identify two unrecorded Arcuospathidium subspecies by morphological observation of both living and protargol-impregnated specimens with the small subunit ribosomal RNA (18S rRNA) gene sequence. These subspecies, Arcuospathidium cultriforme cultriforme (Penard, 1922) Foissner, 1984 and A. cultriforme scalpriforme (Kahl, 1930) Foissner, 2003, were isolated from various terrestrial habitats in July and August 2013, respectivley. Arcuospathidium cultriforme cultriforme is similar to A. cultriforme scalpriforme by a knife-shaped body, a twisted-shaped macronucleus, number of dorsal brushes, position of dorsal brushes, and shape of macronucleus but former mainly differs from the body length to oral bulge length ratio (27-38% vs. 41-53%), extrusome (one types vs. three types), cyst shape (roughly faceted wall vs. smooth surface and thin wall) and number of somatic kinety rows(18-30 vs. 30-44). Additionally, we analyzed the 18S rRNA gene sequences of two A. cultriforme subspecies and compared them with the sequences from GenBank to confirm their identification at the molecular level. As the results of genetic analysis, the 18S rRNA gene sequence of the Korean A. cultriforme cultriforme population is most similar to that of Austrian population. Also, the sequence of the Korean A. cultriforme scalpriforme population is most similar to that of another population with some nucleotide differences.

• Journal of Ginseng Research
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• 제46권5호
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• pp.621-627
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• 2022

Background: Panax ginseng (ginseng) is a traditional medicine that is reported to have cardioprotective effects; ginsenosides are the major bioactive compounds in the ginseng root. Methods: Magnetic molecularly imprinted polymer (MMIP) nanoparticles might be useful for both the extraction of the targeted (imprinted) molecules, and for the delivery of those molecules to cells. In this work, plant growth regulators were used to enhance the adventitious rooting of ginseng root callus; imprinted polymeric particles were synthesized for the extraction of ginsenoside Rb₁ from root extracts, and then employed for subsequent particle-mediated delivery to cardiomyocytes to mitigate hypoxia/reoxygenation injury. Results: These synthesized composite nanoparticles were first characterized by their specific surface area, adsorption capacity, and magnetization, and then used for the extraction of ginsenoside Rb₁ from a crude extract of ginseng roots. The ginsenoside-loaded MMIPs were then shown to have protective effects on mitochondrial membrane potential and cellular viability for H9c2 cells treated with CoCl₂ to mimic hypoxia injury. The protective effect of the ginsenosides was assessed by staining with JC-1 dye to monitor the mitochondrial membrane potential. Conclusion: MMIPs can play a dual role in both the extraction and cellular delivery of therapeutic ginsenosides.

• 한국수산과학회지
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• 제55권1호
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• pp.30-36
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• 2022

We collected a total of four butterfly ray specimens (Gymnura japonica, 213.4-695.0 mm in total length) in Korea from 2016 to 2021 and investigated their morphological and molecular characteristics in order to clarify their taxonomic status. These features are summarized as follows. Disc lozenge-shaped, 1.8-2.0 times broader than long. Tail very short, post-cloaca length 23.9-28.2% in disc width. Snout short, no rostral cartilage. Clasper short, no hook. Dorsal surface uniform yellow or brownish grey, with or without rounded light yellow spots. An analysis of 434 base-pair sequences of mitochondrial DNA cytochrome c oxidase subunit I showed that all four specimens corresponded to G. japonica from Japan (Kimura-2-parameter distance = 0-0.2%), suggesting that the color patterns found may be due to intraspecific color variation. G. japonica resembles Gymnura poecilura but differs in that it has a shorter tail length to disc width (23.9-28.2% in G. japonica vs. 40.1-48.3% in G. poecilura). This study revealed that G. japonica occurred in areas affected by the Tsushima Warm Current, tentatively suggesting that G. japonica may be an indicator species for monitoring marine ecosystem changes due to climate change.

• Molecules and Cells
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• 제45권8호
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• pp.564-574
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• 2022

Epithin/PRSS14 is a membrane serine protease that plays a key role in tumor progression. The protease exists on the cell surface until its ectodomain shedding, which releases most of the extracellular domain. Previously, we showed that the remaining portion on the membrane undergoes intramembrane proteolysis, which results in the liberation of the intracellular domain and the intracellular domain-mediated gene expression. In this study, we investigated how the intramembrane proteolysis for the nuclear function is initiated. We observed that ectodomain shedding of epithin/PRSS14 in mouse breast cancer 4T1 cells increased depending on environmental conditions and was positively correlated with invasiveness of the cells and their proinvasive cytokine production. We identified selenite as an environmental factor that can induce ectodomain shedding of the protease and increase C-C motif chemokine ligand 2 (CCL2) secretion in an epithin/PRSS14-dependent manner. Additionally, by demonstrating that the expression of the intracellular domain of epithin/PRSS14 is sufficient to induce CCL2 secretion, we established that epithin/PRSS14-dependent shedding and its subsequent intramembrane proteolysis are responsible for the metastatic conversion of 4T1 cells under these conditions. Consequently, we propose that epithin/PRSS14 can act as an environment-sensing receptor that promotes cancer metastasis by liberating the intracellular domain bearing transcriptional activity under conditions promoting ectodomain shedding.

• ALGAE
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• 제36권4호
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• pp.241-261
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• 2021

Amphidinium species are amongst the most abundant benthic dinoflagellates in marine intertidal sandy ecosystems. Some of them produce a variety of bioactive compounds that have both harmful effects and pharmaceutical potential. In this study, Amphidinium cells were isolated from intertidal sand collected from the East China Sea. The two strains established were subjected to detailed examination by light, and scanning and transmission electron microscopy. The vegetative cells had a minute, irregular, and triangular-shaped epicone deflected to the left, thus fitting the description of Amphidinium sensu stricto. These strains are distinguished from other Amphidinium species by combination characteristics: (1) longitudinal flagellum inserted in the lower third of the cell; (2) icicle-shaped scales, 276 ± 17 nm in length, on the cell body surface; (3) asymmetrical hypocone with the left side longer than the right; and (4) presence of immotile cells. Therefore, they are described here as Amphidinium stirisquamtum sp. nov. The molecular tree inferred from small subunit rRNA, large subunit rRNA, and internal transcribed spacer-5.8S sequences revealed that A. stirisquamtum is grouped together with the type species of Amphidinium, A. operculatum, in a fully supported clade, but is distantly related to other Amphidinium species bearing body scale. Live A.stirisquamtum cells greatly affected the survival of rotifers and brine shrimp, their primary grazers, making them more susceptible to predation by the higher tropic level consumers in the food web. This will increase the risk of introducing toxicity, and consequently, the bioaccumulation of toxins through marine food webs.