• Molecules and Cells
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• 제42권11호
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• pp.794-803
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• 2019

Ultraviolet light (UV)-induced cellular response has been studied by numerous investigators for many years. Long noncoding RNAs (lncRNAs) are emerging as new regulators of diverse cellular process; however, little is known about the role of lncRNAs in the cellular response to UV treatment. Here, we demonstrate that levels of lncRNA-HOTTIP significantly increases after UV stimulation and regulates the UV-mediated cellular response to UV through the coordinate activation of its neighboring gene Hoxa13 in GC-1 cells (spermatogonia germ cell line). UV-induced, G2/M-phase arrest and early apoptosis can be regulated by lncRNA-HOTTIP and Hoxa13. Furthermore, lncRNA-HOTTIP can up-regulate ${\gamma}-H_2AX$ and p53 expression via Hoxa13 in UV-irradiated GC-1 cells. In addition, p53 has the ability to regulate the expression of both lncRNA-HOTTIP and Hoxa13 in vitro and in vivo. Our results provide new data regarding the role lncRNAs play in the UV response in spermatogenic cells.

• International Journal of Oral Biology
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• 제36권1호
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• pp.31-35
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• 2011

Teeth develop via a reciprocal induction between the ectomesenchyme originating from the neural crest and the ectodermal epithelium. During complete formation of the tooth morphology and structure, many cells proliferate, differentiate, and can be replaced with other structures. Apoptosis is a type of genetically-controlled cell death and a biological process arising at the cellular level during development. To determine if apoptosis is an effective mechanism for eliminating cells during tooth development, this process was examined in the rat mandible including the developing molar teeth using the transferase-mediated dUTP-biotin nick labeling (TUNEL) method. The tooth germ of the mandibular first molar in the postnatal rat showed a variety of morphological appearances from the bell stage to the crown stage. Strong TUNEL-positive reactivity was observed in the ameloblasts and cells of the stellate reticulum. Odontoblasts near the prospective cusp area also showed a TUNEL positive reaction and several cells in the dental papilla, which are the forming pulp, were also stained intensively in this assay. Our results thus show that apoptosis may take place not only in epithelial-derived dental organs but also in the mesenchyme-derived dental papilla. Hence, apoptosis may be an essential biological process in tooth development.

• 한국발생생물학회지:발생과생식
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• 제1권2호
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• pp.189-202
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• 1997

The hypothalamic peptide GnRH plays a central role in the regulation of the mammalian reproductive axis. Recent studies suggested that GnRH stimulates or inhibits the ovarian steroidogenesis and gametogenesis directly. Our previous report indicated that GnRH gene is expressed in adult rat ovary as well as in hypothalamus and that the expressed GnRH may induce the follicular atresia and apoptosis of ovarian granulosa cells in rat. Therfore, we studied whether GnRH gene is expressed in the mouse fetal ovary, when the germ cells are degenerating by apoptosis during gonad diffeerentiation. Mouse fetal gonads were obtained on the 12, 15,18 and 20th day of gestation from the mother mice superovulated (10 IU PMSG and 10 IU hCG) and mated. The morphological changes of fetal ovaries were examined histochemically by hematoxylin-eosin staining. The fetal sex was confirmed by PCR methods for sexing. RT-PCR methods were used to examine the expression of GnRH gene and the sex steroid hormones were determined by conventional radioimmunoassays. The levels of estradiol (E) and progesterone (P) were increaseduntil 18th day of gestation and then E was decreased just before parturition. The morphological changes of fetal gonadal tissue sections showed the ovarian development and coincided with the result of PCR analysis for sexing using ovary- or testis- specific oligonucleotide primers. Immunoreactive GnRH in placenta was decreased gradually until the end of gestation but fetal brain and ovarian GnRH were increased. The level of GnRH gene expression was increased during fetal ovarian development from 12 till 18th day and decreased suddenly on 20th day just before birth. From these results, it is suggested that ovarian GnRh may play a regulatory role on the germ cell differentiation of fetal ovary.

• Molecules and Cells
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• 제24권3호
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• pp.409-415
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• 2007

The retinoblastoma (Rb) gene is one of the most important genes in cell cycle regulation and tumorigenesis. Homozygosity for a germ-line Rb mutation results in embryonic lethality and evokes developmental defects associated with inappropriate S-phase entry and high levels of apoptosis. Although Rb has been extensively studied, more target genes need to be identified and characterized to unravel the precise mechanism of Rb function. In order to identify Rb-regulated genes, we analyzed the gene expression profile of Rb-deficient mouse embryo fibroblasts (MEFs), and identified an unknown gene, RbEST47, that is transcriptionally upregulated in Rb-deficient MEFs. This gene is conserved from fruitfly to human. It is expressed in brain, lung, kidney, and testis, and is located on mouse chromosome 2. This region is syntenic to human chromosome 9q34.3, which frequently exhibits loss of heterozygosity in neoplastic diseases. RbEST47 was considerably down-regulated in immortalized cells, and showed cell cycle-dependent expression, suggesting important roles in S and/or G2.

• Journal of Ginseng Research
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• 제35권3호
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• pp.294-300
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• 2011

Zearalenone (ZEA) is a phenolic resorcylic acid lactone compound produced by several species of Fusarium. ZEA has toxic effects in the testes of domestic and laboratory animals. Korean red ginseng (KRG), the steamed root of Panax ginseng Meyer, has multiple pharmacological effects such as vasorelaxation, anti-thrombosis, anti-hypertension, etc. In this study, we investigated the effects of KRG extract on testicular toxicity induced by ZEA. Rats were treated with 300 mg/kg oral doses of KRG for 4 weeks every other day. The rats were then treated with a single dose of 5 mg/kg ZEA delivered intraperitoneally, whereas control rats received only doses of the vehicle. As a result, germ cell apoptosis induced by ZEA was decreased by KRG pre-treatment. In addition, Fas and Fas-L expression was reduced in rats that received KRG pre-treatment compared to ones treated with ZEA alone. In conclusion, impaired spermatogenesis resulting from ZEA treatment was prevented by KRG through Fas-Fas L modulating.

• Molecular & Cellular Toxicology
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• 제5권4호
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• pp.310-316
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• 2009

Some environmental chemicals have been shown to cause liver-toxicity as the result of bioaccumulation. Particularly, fungicides have been shown to cause varying degrees of hepatictoxicity and to disrupt steroid hormone homeostasis in in vivo models. The principal objective of this study was to evaluate the liver-toxic responses of environmental chemicals-in this case selected fungicides and parasiticides-in order to determine whether or not this agent differentially affected its toxicogenomic activities in hepatic tumor cell lines. To determine the gene expression profiles of 3 fungicides (triadimefon, myclobutanil, vinclozolin) and 1 parasiticide (dibutyl phthalate), we utilized a modified HazChem human array V2. Additionally, in order to observe the differential alterations in its time-dependent activities, we conducted two time (3 hr, 48 hr) exposures to the respective IC20 values of four chemicals. As a result, we analyzed the expression profiles of a total of 1638 genes, and we identified 70 positive significant genes and 144 negative significant genes using four fungicidic and parasiticidic chemicals, using SAM (Significant Analysis of Microarray) methods (q-value<0.5%). These genes were analyzed and identified as being related to apoptosis, stress responses, germ cell development, cofactor metabolism, and lipid metabolism in GO functions and pathways. Additionally, we found 120 genes among those time-dependently differentially expressed genes, using 1-way ANOVA (P-value<0.05). These genes were related to protein metabolism, stress responses, and positive regulation of apoptosis. These data support the conclusion that the four tested chemicals have common toxicogenomic effects and evidence respectively differential expression profiles according to exposure time.

• Molecules and Cells
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• 제25권1호
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• pp.119-123
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• 2008

Pyrimidine antagonists including 5-Fluorouracil (5-FU) have been used in chemotherapy for cancer patients for over 40 years. 5-FU, especially, is a mainstay treatment for colorectal cancer. It is a pro-drug that is converted to the active drug via the nucleic acid biosynthetic pathway. The metabolites of 5-FU inhibit normal RNA and DNA function, and induce apoptosis of cancer cells. One of the major obstacles to successful chemotherapy is the resistance of cancer cells to anti-cancer drugs. Therefore, it is important to elucidate resistance mechanisms to improve the efficacy of chemotherapy. We have used C. elegans as a model system to investigate the mechanism of resistance to 5-FU, which induces germ cell death and inhibits larval development in C. elegans. We screened 5-FU resistant mutants no longer arrested as larvae by 5-FU. We obtained 18 mutants out of 72,000 F1 individuals screened, and mapped them into three complementation groups. We propose that C. elegans could be a useful model system for studying mechanisms of resistance to anti-cancer drugs.

• 대한수의학회지
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• 제59권2호
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• pp.59-67
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• 2019

We investigated whether ${\beta}$-carotene (${\beta}-CA$) or ellagic acid (EA), originating from various fruits and vegetables, has a preventive effect against male infertility induced by exogenous scrotal hyperthermia. ICR adult mice were intraperitoneally treated with 10 mg/kg of ${\beta}-CA$ or EA daily for 13 days consecutively. During this time, mice were subjected to transient scrotal heat stress in a water bath at $43^{\circ}C$ for 20 min on day 7, and their testes and blood were obtained on day 14 for histopathologic and biochemical analyses. Heat stress induced significant testicular weight reduction, germ cell loss and degeneration, as well as abnormal localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and manganese superoxide dismutase (MnSOD) in spermatogenic and Leydig cells. Heat stress also altered the levels of oxidative stress (lipid peroxidation, SOD activity, and PHGPx, MnSOD, and $HIF-1{\alpha}$ mRNAs), apoptosis (Bax, Bcl-xL, caspase 3, $NF-{\kappa}B$, and $TGF-{\beta}1$ mRNAs), and androgen biosynthesis (serological testosterone concentration and $3{\beta}$-hydroxysteroid dehydrogenase mRNA) in testes. These changes were all improved significantly by ${\beta}-CA$ treatment, but only slightly improved by EA treatment. These findings indicate that ${\beta}-CA$, through modulations of oxidative stress, apoptosis, and androgen biosynthesis, is a potent preventive agent against testicular injuries induced by scrotal hyperthermia.

• BMB Reports
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• 제38권2호
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• pp.206-210
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• 2005

Gonadogenesis is a complicated process which involves multi-gene interactions. A rainbow trout (Oncorhynchus mykiss) gene spermatogenesis associated 4 (SPATA4) was cloned and characterized from adult rainbow trout testis. The cDNA sequence of rainbow trout SPATA4 contains an open reading frame of 1, 081 nucleatides encoding a putative protein of 259 amino acids. The putative protein from rainbow trout shares a 76.8% homology with zebrafish SPATA4. No trans-membrane regions or signal peptide were detected using bioinformatics methods. Subcellular localization analysis revealed that rainbow trout SPATA4 was a nuclear protein with highest possibility (39.1%). Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the distribution of rainbow trout SPATA4 in eleven organs of adult rainbow trout. The result demonstrated that this gene express specifically in testis and slight amount of expression was detected in ovary. Further analysis of SPATA4 characterization and function in rainbow trout may provide insight into the understanding of gonadogenesis process.

• Molecules and Cells
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• 제39권3호
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• pp.204-210
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• 2016

DNA damage responses are important for the maintenance of genome stability and the survival of organisms. Such responses are activated in the presence of DNA damage and lead to cell cycle arrest, apoptosis, and DNA repair. In Caenorhabditis elegans, double-strand breaks induced by DNA damaging agents have been detected indirectly by antibodies against DSB recognizing proteins. In this study we used a comet assay to detect DNA strand breaks and to measure the elimination of DNA strand breaks in mitotic germline nuclei of C. elegans. We found that C. elegans brc-1 mutants were more sensitive to ionizing radiation and camptothecin than the N2 wild-type strain and repaired DNA strand breaks less efficiently than N2. This study is the first demonstration of direct measurement of DNA strand breaks in mitotic germline nuclei of C. elegans. This newly developed assay can be applied to detect DNA strand breaks in different C. elegans mutants that are sensitive to DNA damaging agents.