• Molecules and Cells
• /
• v.39 no.4
• /
• pp.286-291
• /
• 2016

Epstein-Barr virus (EBV) is the prototypical ${\gamma}$-herpesvirus and an obligate human pathogen that infects mainly epithelial cells and B cells, which can result in malignancies. EBV infects these target cells by fusing with the viral and cellular lipid bilayer membranes using multiple viral factors and host receptor(s) thus exhibiting a unique complexity in its entry machinery. To enter epithelial cells, EBV requires minimally the conserved core fusion machinery comprised of the glycoproteins gH/gL acting as the receptor-binding complex and gB as the fusogen. EBV can enter B cells using gp42, which binds tightly to gH/gL and interacts with host HLA class II, activating fusion. Previously, we published the individual crystal structures of EBV entry factors, such as gH/gL and gp42, the EBV/host receptor complex, gp42/HLA-DR1, and the fusion protein EBV gB in a postfusion conformation, which allowed us to identify structural determinants and regions critical for receptor-binding and membrane fusion. Recently, we reported different low resolution models of the EBV B cell entry triggering complex (gHgL/gp42/HLA class II) in "open" and "closed" states based on negative-stain single particle electron microscopy, which provide further mechanistic insights. This review summarizes the current knowledge of these key players in EBV entry and how their structures impact receptor-binding and the triggering of gB-mediated fusion.

• Journal of Gastric Cancer
• /
• v.10 no.3
• /
• pp.91-98
• /
• 2010

Purpose: Silent mating-type information regulation 2 homologue 1 (SIRT1) is a nicotinamide adenine dinucleotide-dependent deacetylase. SIRT1 plays an important role in the regulation of cell death/survival and stress response in mammals. The aim of this study was to investigate whether the SIRT1 gene is involved in the development or progression of gastric cancers. Materials and Methods: SIRT1 and p53 genes in 86 gastric cancers were examined for genetic alterations by PCR-single strand conformation polymorphism sequencing, as well as SIRT1 protein expression in 170 gastric cancers by immunohistochemistry. Results: In the genetic analysis, we found SIRT1 and p53 mutations in two and 12 cases, respectively. Two missense mutations, c.599 C>T (T200I) and c.1258 G>A (E420K), were detected in the SIRT1 gene coding region. The SIRT1 and p53 mutation were found in mutually exclusive gastric cancers. The immunohistochemistry revealed that SIRT1 overexpression was found in 95 (55.9%) of 170 gastric cancers. Altered SIRT1 expression was not statistically associated with clinicopathological parameters, including tumor differentiation, location, lymph node metastasis, or p53 expression. Two cases with an SIRT1 mutation showed increased SIRT1 expression. Conclusions: These results suggest that genetic alterations and overexpression of the SIRT1 gene may contribute to gastric cancer development.

• Genomics & Informatics
• /
• v.7 no.4
• /
• pp.195-202
• /
• 2009

BIRC5 (Survivin) belongs to the inhibitor of apoptosis gene family. The BIRC5 protein inhibits caspases and consequently blocks apoptosis. Thus, BIRC5 contributes to the progression of cancer allowing for continued cell proliferation and survival. In this study, we identified eight sequence variants of BIRC5 through direct DNA sequencing. Among the eight single nucleotide polymorphisms (SNPs), six common variants with frequencies higher than 0.05 were selected for larger-scale genotyping (n=1,066). Results of the study did not show any association between the promoter region polymorphisms and the clearance of hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) occurrence. This is in line with a previous study in which polymorphisms in the promoter region does not influence the function of BIRC5. Initially, we were able to detect a signal with the ＋9194A>G, which disappeared after multiple corrections but led to a change in amino acid. Similarly, we were also able to detect an association signal between two haplotypes (haplotype-2 and haplotype-5) on the onset age of HCC and/or HCC occurrence, but the signals also disappeared after multiple corrections. As a result, we concluded that there was no association between BIRC5 polymorphisms and the clearance HBV infection and/or HCC occurrence. However, our results might useful to future studies.

• Journal of Embryo Transfer
• /
• v.29 no.4
• /
• pp.375-383
• /
• 2014

Klotho (KL) is a single transmembrane protein composed of KL1 and KL2 repeats possessing ${\beta}$-glucuronidase activity and maintains calcium homeostasis in physiological state. It has been implicated in pigs that calcium is important for the establishment and maintenance of pregnancy, and our previous study has shown that transient receptor potential vanilloid type 6 (TRPV6), a calcium ion transporter, is predominantly expressed in the uterine endometrium during pregnancy in pigs. However, expression and function of KL in the uterine endometrium has not been determined in pigs. Thus, the present study determined expression and regulation of KL in the uterine endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that levels of KL mRNA decreased between Days 12 to 15 of the estrous cycle, and its expression showed a biphasic manner during pregnancy. KL mRNA was expressed in conceptuses and in chorioallantoic tissues during pregnancy. Explant culture study showed that expression levels of KL were not affected by treatment of steroid hormones or interleukin-1beta during the implantation period. Furthermore, levels of KL mRNA in the uterine endometrium from gilts carrying somatic cell nuclear transfer (SCNT)-derived embryos were significantly lower than those from gilts carrying natural mating-derived embryos on Day 12 of pregnancy. These results exhibited that KL was expressed at the maternal-conceptus interface in a pregnancy status- and stage-specific manner, and its expression was affected by SCNT procedure, suggesting that KL may play an important role in the establishment and maintenance of pregnancy in pigs.

• Laboraroty Animal Research
• /
• v.34 no.4
• /
• pp.279-287
• /
• 2018

Placenta specific 8 (PLAC8, also known as ONZIN) is a multi-functional protein that is highly expressed in the intestine, lung, spleen, and innate immune cells, and is involved in various diseases, including cancers, obesity, and innate immune deficiency. Here, we generated a Plac8 knockout mouse using the CRISPR/Cas9 system. The Cas9 mRNA and two single guide RNAs targeting a region near the translation start codon at Plac8 exon 2 were microinjected into mouse zygotes. This successfully eliminated the conventional translation start site, as confirmed by Sanger sequencing and PCR genotyping analysis. Unlike the previous Plac8 deficient models displaying increased adipose tissue and body weights, our male Plac8 knockout mice showed rather lower body weight than sex-matched littermate controls, though the only difference between these two mouse models is genetic context. Differently from the previously constructed embryonic stem cell-derived Plac8 knockout mouse that contains a neomycin resistance cassette, this knockout mouse model is free from a negative selection marker or other external insertions, which will be useful in future studies aimed at elucidating the multi-functional and physiological roles of PLAC8 in various diseases, without interference from exogenous foreign DNA.

• Journal of Animal Science and Technology
• /
• v.62 no.6
• /
• pp.765-776
• /
• 2020

The retinal degenerative disease, progressive retinal atrophy (PRA) is a major reason of vision impairment in canine population. Canine PRA signifies an inherently dissimilar category of retinal dystrophies which has solid resemblances to human retinis pigmentosa. Even though much is known about the biology of PRA, the knowledge about the intricate connection among genetic loci, genes and pathways associated to this disease in dogs are still remain unknown. Therefore, we have performed a genome wide association study (GWAS) to identify susceptibility single nucleotide polymorphisms (SNPs) of PRA. The GWAS was performed using a case-control based association analysis method on PRA dataset of 129 dogs and 135,553 markers. Further, the gene-set and pathway analysis were conducted in this study. A total of 1,114 markers associations with PRA trait at p < 0.01 were extracted and mapped to 640 unique genes, and then selected significant (p < 0.05) enriched 35 gene ontology (GO) terms and 5 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways contain these genes. In particular, apoptosis process, homophilic cell adhesion, calcium ion binding, and endoplasmic reticulum GO terms as well as pathways related to focal adhesion, cyclic guanosine monophosphate)-protein kinase G signaling, and axon guidance were more likely associated to the PRA disease in dogs. These data could provide new insight for further research on identification of potential genes and causative pathways for PRA in dogs.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.9
• /
• pp.1110-1119
• /
• 2022

Fe-S clusters are versatile and essential cofactors that participate in multiple and fundamental biological processes. In Escherichia coli, the biogenesis of these cofactors requires either the housekeeping Isc pathway, or the stress-induced Suf pathway which plays a general role under conditions of oxidative stress or iron limitation. In the present work, the Fe-S cluster assembly Isc and Suf systems of acidophilic Bacteria and Archaea, which thrive in highly oxidative environments, were studied. This analysis revealed that acidophilic microorganisms have a complete set of genes encoding for a single system (either Suf or Isc). In acidophilic Proteobacteria and Nitrospirae, a complete set of isc genes (iscRSUAX-hscBA-fdx), but not genes coding for the Suf system, was detected. The activity of the Isc system was studied in Leptospirillum sp. CF-1 (Nitrospirae). RT-PCR experiments showed that eight candidate genes were co-transcribed and conform the isc operon in this strain. Additionally, RT-qPCR assays showed that the expression of the iscS gene was significantly up-regulated in cells exposed to oxidative stress imposed by 260 mM Fe₂(SO₄)₃ for 1 h or iron starvation for 3 h. The activity of cysteine desulfurase (IscS) in CF-1 cell extracts was also upregulated under such conditions. Thus, the Isc system from Leptospirillum sp. CF-1 seems to play an active role in stressful environments. These results contribute to a better understanding of the distribution and role of Fe-S cluster protein biogenesis systems in organisms that thrive in extreme environmental conditions.

• Journal of Chest Surgery
• /
• v.56 no.1
• /
• pp.35-41
• /
• 2023

Background: We analyzed our experience with descending necrotizing mediastinitis (DNM) treatment and investigated the efficacy of video-assisted thoracoscopic surgery (VATS) for mediastinal drainage. Methods: This retrospective analysis included patients who underwent surgical drainage for DNM at our hospital from 2005 to 2020. We analyzed patients' baseline characteristics, surgical data, and perioperative outcomes and compared them according to the mediastinal drainage approach among patients with type II DNM. Results: Twenty-five patients (male-to-female ratio, 18:7) with a mean age of 54.0±12.9 years were enrolled in this study. The most common infection sources were pharyngeal infections (60%). Most patients had significantly increased white blood cell counts, elevated C-reactive protein levels, and decreased albumin levels on admission. The most common DNM type was type IIB (n=16, 64%), while 5 and 4 patients had types I and IIA, respectively. For mediastinal drainage, the transcervical approach was used in 15 patients and the transthoracic approach (VATS) in 10 patients. The mean length of hospital stay was 26.5±23.8 days, and the postoperative morbidity and in-hospital mortality rates were 24% and 12%, respectively. No statistically significant differences were found among patients with type II DNM between the transcervical and VATS groups. However, the VATS group showed shorter mean antibiotic therapy duration, drainage duration, and hospital stay length than the transcervical group. Conclusion: DNM manifested as severe infection requiring long-term inpatient treatment, with a mortality rate of 12%. Thus, active treatment with a multidisciplinary approach is crucial, and mediastinal drainage using VATS is considered relatively safe and effective.

• Journal of Animal Reproduction and Biotechnology
• /
• v.37 no.4
• /
• pp.246-254
• /
• 2022

Current studies have revealed the capacity of mesenchymal stem cells (MSCs) in term of immunomodulatory properties, and this distinct potential is downgraded according to the disease duration of patients-derived MSCs. In order to enhance the immunomodulatory and anti-tumorigenic properties of the rheumatoid arthritis (RA) joints-derived MSCs, we aggregate synovial fluid-derived MSCs from RA joints (RA-hMSCs) into 3D-spheroids by the use of hanging drop culture method. Cells were isolated from synovial fluids of RA joints with longstanding active status over 13 years. For aggregation of RA-hMSCs into 3D-spheroids, cells were plated in hanging drops in 30 μL of advanced DMEM (ADMEM) containing 25,000-30,000 cells/drop and cultured for 48 h. To analyze the comparative immunomodulatory effects of 3D-spheroid and 2D monolayer cultured RA-hMSCs and then cells were cultured in ADMEM supplemented with 20% of synovial fluids of RA patients for 48 h and were evaluated by qRT-PCR for their expression of mRNA levels of inflammatory and anti-inflammatory markers. Cellular aggregation of RA-hMSCs was observed and cells were aggregate into a single sphere. Following treatment of RA patient's synovial fluids into the RA-hMSCs, spheroids formed RA-hMSCs showed significantly (p < 0.05) higher expression of TNFα stimulated gene/protein 6 (TSG-6) than the monolayer cultured RA-hMSCs. Therefore, the 3D-spheroid culture methods of RA-hMSCs were more effective than 2D monolayer cultures in suppressing inflammatory response treated with 20% of RA-synovial fluids by expression of TNFα (TSG-6) according to the immune response and enhanced secretion of inflammatory factors.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.3
• /
• pp.710-724
• /
• 2024

Flavobacterium can synthesize xanthophyll, particularly the pigment zeaxanthin, which has significant economic value in nutrition and pharmaceuticals. Recently, the use of carotenoid biosynthesis by bacteria and yeast fermentation technology has shown to be very efficient and offers significant advantages in large-scale production, cost-effectiveness, and safety. In the present study, JSWR-1 strain capable of producing xanthophyll pigment was isolated from a freshwater reservoir in Wanju-gun, Republic of Korea. Based on the morphological, physiological, and molecular characteristics, JSWR-1 classified as belonging to the Flavobacterium species. The bacterium is strictly aerobic, Gram-negative, rod-shaped, and psychrophilic. The completed genome sequence of the strain Flavobacterium sp. JSWR-1 is predicted to be a single circular 3,425,829-bp chromosome with a G+C content of 35.2% and 2,941 protein-coding genes. The optimization of carotenoid production was achieved by small-scale cultivation, resulting in zeaxanthin being identified as the predominant carotenoid pigment. The enhancement of zeaxanthin biosynthesis by applying different light-irradiation, variations in pH and temperature, and adding carbon and nitrogen supplies to the growth medium. A significant increase in intracellular zeaxanthin concentrations was also recorded during fed-batch fermentation achieving a maximum of 16.69 ± 0.71 mg/l, corresponding to a product yield of 4.05 ± 0.15 mg zeaxanthin per gram cell dry weight. Batch and fed-batch culture extracts exhibit significant antioxidant activity. The results demonstrated that the JSWR-1 strain can potentially serve as a source for zeaxanthin biosynthesis.