• Biomolecules & Therapeutics
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• v.27 no.6
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• pp.530-539
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• 2019

Brain aging is an inevitable process characterized by structural and functional changes and is a major risk factor for neurodegenerative diseases. Most brain aging studies are focused on neurons and less on astrocytes which are the most abundant cells in the brain known to be in charge of various functions including the maintenance of brain physical formation, ion homeostasis, and secretion of various extracellular matrix proteins. Altered mitochondrial dynamics, defective mitophagy or mitochondrial damages are causative factors of mitochondrial dysfunction, which is linked to age-related disorders. Etoposide is an anti-cancer reagent which can induce DNA stress and cellular senescence of cancer cell lines. In this study, we investigated whether etoposide induces senescence and functional alterations in cultured rat astrocytes. Senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity was used as a cellular senescence marker. The results indicated that etoposide-treated astrocytes showed cellular senescence phenotypes including increased SA-${\beta}$-gal-positive cells number, increased nuclear size and increased senescence-associated secretory phenotypes (SASP) such as IL-6. We also observed a decreased expression of cell cycle markers, including PhosphoHistone H3/Histone H3 and CDK2, and dysregulation of cellular functions based on wound-healing, neuronal protection, and phagocytosis assays. Finally, mitochondrial dysfunction was noted through the determination of mitochondrial membrane potential using tetramethylrhodamine methyl ester (TMRM) and the measurement of mitochondrial oxygen consumption rate (OCR). These data suggest that etoposide can induce cellular senescence and mitochondrial dysfunction in astrocytes which may have implications in brain aging and neurodegenerative conditions.

• Childhood Kidney Diseases
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• v.23 no.2
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• pp.59-66
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• 2019

Background: Primary hyperoxaluria (PH), a rare inborn error of glyoxylate meta bolism causing overproduction of oxalate, is classified into three genetic subgroups: type 1-3 (PH1-PH3) caused by AGXT, GRHPR, and HOGA1 gene mutations, respectively. We performed a retrospective case series study of Korean pediatric patients with PH. Methods: In total, 11 unrelated pediatric patients were recruited and their phenotypes and genotypes were analyzed by a retrospective review of their medical records. Results: Mutational analyses revealed biallelic AGXT mutations (PH1) in nine patients and a single heterozygous GRHPR and HOGA1 mutation in one patient each. The c.33dupC was the most common AGXT mutation with an allelic frequency of 44%. The median age of onset was 3 months (range, 2 months-3 years), and eight patients with PH1 presented with end stage renal disease (ESRD). Patients with two truncating mutations showed an earlier age of onset and more frequent retinal involvement than patients with one truncating mutation. Among eight PH1 patients presenting with ESRD, five patients were treated with intensive dialysis followed by liver transplantation (n=5) with/without subsequent kidney transplantation (n=3). Conclusion: Most patients presented with severe infantile forms of PH. Patients with two truncating mutations displayed more severe phenotypes than those of patients with one truncating mutation. Sequential liver and kidney transplantation was adopted for PH1 patients presenting with ESRD. A larger nation-wide multicenter study is needed to confirm the genotype-phenotype correlations and outcomes of organ transplantation.

• Development and Reproduction
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• v.23 no.1
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• pp.63-72
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• 2019

The head gap gene buttonhead (btd) is required for the patterning of head segments in the early Drosophila embryo. Mutant phenotypes of btd display a gap-like phenotype in which antennal, intercalary, mandibular and the anterior portion of the maxillary segments are eliminated. In agreement with the phenotypes, btd is expressed in a stripe covering the head segments at the blastoderm stage. During the early phase of the germband extension, btd is expressed in stripes with single segmental periodicity, which is required for the formation of the peripheral nervous system. In contrast to the key role of btd in Drosophila embryonic development, it has been suggested that Tribolium ortholog of btd (Tc-btd) is dispensable for embryonic head development. In order for better understanding of the requirement of Tc-btd in the early Tribolium embryo, we re-analyzed the expression patterns and functions of Tc-btd during embryonic segmentation. Tc-btd is expressed in segmental stripes at the stages of blastoderm and germband elongation. Up to 28.3% of embryos in which Tc-btd is knocked down displays the loss of antennal, mandibular and the pregnathal regions in the head, with abdominal segments being disrupted in the trunk. Our findings suggest that Tc-btd is required for the head and trunk development in the early Tribolium embryo.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.31-31
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• 1999

Characterization of mutant mice has been utilized as an animal model for the study of human inherited diseases. In addition to the pathogenesis stduy using the mutant mice, the mice have been used for the identification of the genes causing the phenotypes. Functional cloning and positional cloning are two approaches, depending on the phenotypes of the mutant mice. Though it takes a long time positional cloning has been well used to identify the gene of which function can not be presumed from the mouse phenotype. Recently by the advance of the molecular tools and the human genome project close to 10,000 genetic markers are developed to make the procedure faster. We obtained a new mutant mouse, sims, spontaneously arose and the affected mouse has a mild tremor and seizure was observed. Homozygote in either sex is sterile since uterus growth in female and seminal vesicle in male are not induced for the growth in puberty, implying the abnormal hormonal regulation during puberty. Supporting this, there is no detectable testosterone in the serum of the mutant male and the brain of the mutant is 30% heavier than littermate. To identify the location of the mutated gene, intraspecies cross to CAST/Ei was carried out and the 37 affected mice was analyzed for the linkage. The gene was mapped on chromosome 18, 20 cM from the centromere. More than 500 F2 progenies have been analyzed for the linkage and the locus becomes narrow within 3cM between Egrl and Fgf gene.f gene.

• Genes and Genomics
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• v.40 no.12
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• pp.1269-1277
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• 2018

Bcl2-associated athanogene 3 (BAG3) mutations have been reported to cause the myofibrillar myopathy (MFM) which shows progressive limb muscle weakness, respiratory failure, and cardiomyopathy. Myopathy patients with BAG3 mutation are very rare. We described a patient showing atypical phenotypes. We aimed to find the genetic cause of Korean patients with sensory motor polyneuropathy, myopathy and rigid spine. We performed whole exome sequencing (WES) with 423 patients with sensory motor polyneuropathy. We found BAG3 mutation in one patient with neuropathy, myopathy and rigid spine syndrome, and performed electrophysiological study, whole body MRI and muscle biopsy on the patient. A de novo heterozygous p.Pro209Leu (c.626C>T) mutation in BAG3 was identified in a female myopathy. She first noticed a gait disturbance and spinal rigidity at the age of 11, and serum creatine kinase levels were elevated ninefolds than normal. She showed an axonal sensory-motor polyneuropathy like Charcot-Marie-Tooth disease (CMT), myopathy, rigid spine and respiratory dysfunction; however, she did not show any cardiomyopathy, which is a common symptom in BAG3 mutation. Lower limb MRI and whole spine MRI showed bilateral symmetric fatty atrophy of muscles at the lower limb and paraspinal muscles. When we track traceable MRI 1 year later, the muscle damage progressed slowly. As far as our knowledge, this is the first Korean patient with BAG3 mutation. We described a BAG3 mutation patient with atypical phenotype of CMT and myopathy, and those are expected to broaden the clinical spectrum of the disease and help to diagnose it.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.1-10
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• 2010

Five mutants were investigated at the molecular level to determine the factors responsible for mutated endosperm types. They were classified as high (HA) or low amylose (LA) phenotypes based on the amylose content in endosperm. The five were previously produced from Ilpum and Shindongjin cultivar treated with N-methyl-N-nitrosourea and gamma-ray irradiation, respectively. Analysis of the genomic structure and expression of Granule-bounded Starch Synthase I (GBSSI) genes revealed that mutants generally showed a higher incidence of nucleotide transition than transversion, and the $A:T{\rightarrow}G:C$ transition was particularly prevalent. The rates of nucleotide substitution in HA mutants were generally higher than those in the LA mutants, leading to higher substitutions of amino acid in the HA mutants. Neither nucleotide substitutions interfering with intron splicing or causing early termination of protein translation were found, nor any large-sized deletions or additions were found in all the mutants. In principle, amylose content can be regulated by three factors: internal alterations of GBSSI protein, the strength of gene expression, and other unknown external factors. Our results indicate that the endosperm mutants from Shindongjin arose from internal alterations of GBSSI proteins, which may be the result of amino acid substitutions. On the other hand, the Ilpum mutants might be principally caused by the alteration of gene expression level. Analysis of another three glutinous cultivars revealed that the major factor leading to glutinous phenotypes is the 23-bp duplicative motif (5'-ACGGGTTCCAGGGCCTCAAGCCC-3') commonly found in exon 2, which results in the premature termination of protein translation leading to the production of a non-functional GBSSI enzyme.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.157-165
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• 2019

Di- and tri-methylation of lysine 4 on histone H3 (H3K4me2 and H3K4me3, respectively) are epigenetic markers of active genes. Complex associated with Set1 (COMPASS) mediates these H3K4 methylations. The involvement of COMPASS activity in secondary metabolite (SM) biosynthesis was first demonstrated with an Aspergillus nidulans cclA knockout mutant. The cclA knockout induced the transcription of two cryptic SM biosynthetic gene clusters, leading to the production of the cognate SM. Monascus spp. are filamentous fungi that have been used for food fermentation in eastern Asia, and the pigment Monascus azaphione (MAz) is their main SM. Monascus highly produces MAz, implying that the cognate biosynthetic genes are highly active in transcription. In the present study, we examined how COMPASS activity modulates MAz biosynthesis by inactivating Monascus purpureus cclA (Mp-cclA) and swd1 (Mp-swd1). For both ${\Delta}Mp-cclA$ and ${\Delta}Mp-swd1$, a reduction in MAz production, accompanied by an abated cell growth, was observed. Suppression of MAz production was more effective in an agar culture than in the submerged liquid culture. The fidelity of the ${\Delta}Mp-swd1$ phenotypes was verified by restoring the WT-like phenotypes in a reversion recombinant mutant, namely, trpCp: Mp-swd1, that was generated from the ${\Delta}Mp-swd1$ mutant. Real-time quantitative Polymerase chain reaction analysis indicated that the transcription of MAz biosynthetic genes was repressed in the ${\Delta}Mp-swd1$ mutant. This study demonstrated that MAz biosynthesis is under the control of COMPASS activity and that the extent of this regulation is dependent on growth conditions.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.68-76
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• 2019

Background: In colorectal cancer (CRC), 40-60% of patients develop metastasis. The epithelial-mesenchymal transition (EMT) is a pivotal and intricate process that increases the metastatic potential of CRC. The aim of this study was to investigate the effect of Korean Red Ginseng extract (RGE) on colorectal metastasis through inhibition of EMT and the metastatic abilities of CRC cells. Methods: To investigate the effect of RGE on the metastatic phenotypes of CRC cells, CT26 and HT29 cells were evaluated by using an adhesion assay, a wound-healing assay, an invasion assay, zymography, and real-time reverse transcription-polymerase chain reaction. Western-blot analysis was conducted to elucidate the molecular mechanisms of RGE, which showed an inhibitory effect on the transforming growth factor-${\beta}1$ ($TGF-{\beta}1$)-induced EMT in HT29 cells. Additionally, the antimetastatic effect of RGE was evaluated in a mouse model of lung metastasis injected with CT26 cells. Results: RGE decreased the adhesion and migration ability of the CT26 cells and TGF-${\beta}1$-treated HT29 cells. The invasion ability was also reduced by RGE treatment through the inhibition of matrix metalloproteinase-9 expression and activity. Moreover, RGE suppressed the TGF-${\beta}1$-induced EMT via TGF-${\beta}1$/Smad-signaling-mediated Snail/E-cadherin expression in HT29 cells and lung tissue in CT26 tumor-bearing mice. Conclusion: Our results demonstrated that RGE inhibited colorectal lung metastasis through a reduction in metastatic phenotypes, such as migration, invasion, and the EMT of CRC cells.

• Genes and Genomics
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• v.40 no.12
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• pp.1331-1338
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• 2018

Although there have been plenty of dominance deviation analysis, few studies have dealt with multiple phenotypes. Because researchers focused on multiple phenotypes (final weight and backfat thickness) of Landrace pigs, the classification of the genes was possible. With genome-wide association studies (GWASs), we analyzed the additive and dominance effects of the single nucleotide polymorphisms (SNPs). The classification of the pig genes into four categories (overdominance in final weight, overdominance in backfat thickness and overdominance in final weight, underdominance in backfat thickness, etc.) can enable us not only to analyze each phenotype's dominant effects, but also to illustrate the gene ontology (GO) analysis with different aspects. We aimed to determine the additive and dominant effect in backfat thickness and final weight and performed GO analysis. Using additive model and dominance deviation analysis in GWASs, Landrace pigs' overdominant and underdominant SNP effects in final weight and backfat thickness were surveyed. Then through GO analysis, we investigated the genes that were classified in the GWASs. The major GO terms of the underdominant effects in final weight and overdominant effects in backfat thickness were ion transport with the SLC8A3, KCNJ16, P2RX7 and TRPC3 genes. Interestingly, the major GO terms in the underdominant effects in the final weight and the underdominant effects in the backfat thickness were the regulation of ion transport with the STAC, GCK, TRPC6, UBASH3B, CAMK2D, CACNG4 and SCN4B genes. These results demonstrate that ion transport and ion transport regulation genes have distinct dominant effects. Through GWASs using the mode of linear additive model and dominance deviation, overdominant effects and underdominant effects in backfat thickness was contrary to each other in GO terms (ion transport and ion transport regulation, respectively). Additionally, because ion transport and ion transport regulation genes are associative with adipose tissue accumulation, we could infer that these two groups of genes had to do with unique fat accumulation mechanisms in Landrace pigs.

• BMB Reports
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• v.52 no.8
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• pp.520-525
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• 2019

Dihydroartemisinin (DHA) has been reported to possess anti-cancer activity against many cancers. However, the pharmacologic effect of DHA on HBV-positive hepatocellular carcinoma (HCC) remains unknown. Thus, the objective of the present study was to determine whether DHA could inhibit the proliferation of HepG2.2.15 cells and uncover the underlying mechanisms involved in the effect of DHA on HepG2.2.15 cells. We found that DHA effectively inhibited HepG2.2.15 HCC cell proliferation both in vivo and in vitro. DHA also reduced the migration and tumorigenicity capacity of HepG2.2.15 cells. Regarding the underlying mechanisms, results showed that DHA induced cellular senescence by up-regulating expression levels of proteins such as p-ATM, p-ATR, ${\gamma}-H_2AX$, P53, and P21 involved in DNA damage response. DHA also induced autophagy (green LC3 puncta gathered together and LC3II/LC3I ratio increased through AKT-mTOR pathway suppression). Results also revealed that DHA-induced autophagy was not linked to senescence or cell death. TPP1 (telomere shelterin) overexpression could not rescue DHA-induced anticancer activity (cell proliferation). Moreover, DHA down-regulated TPP1 expression. Gene knockdown of TPP1 caused similar phenotypes and mechanisms as DHA induced phenotypes and mechanisms in HepG2.2.15 cells. These results demonstrate that DHA might inhibit HepG2.2.15 cells proliferation through inducing cellular senescence and autophagy.