• Development and Reproduction
• /
• v.13 no.4
• /
• pp.207-215
• /
• 2009

Numerous factors can affect the activities of hypothalamus-pituitary-gonad (HPG) hormonal axis, resulting in alteration of reproductive capacity or status such as onset of puberty and menopause. Soon after the finding of leptin, a multifunctional hormone secreted from adipocytes, a close relationship between reproduction and body energy balance have been manifested. Ghrelin, another multifunctional hormone from gastrointestinal tract, is an endogenous ligand of growth hormone secretagogue receptor (GHSR), and is thought to be a counterpart of leptin in the regulation of energy homeostasis. As expected, ghrelin can also modulate the reproductive capacity through the modulation of activities of HPG axis. This paper summarizes the current knowledge on the discovery, gene structures, tissue distribution and roles of ghrelin and GHSRs in mammalian reproduction in particular modulation of reproductive hormone secretion in HPG axis. Like POMC gene expression in pituitary gland, preproghrelin gene can generate a complex repertoire of transcripts which further undergo alternative splicing and posttranslational modifications. Concerning the roles of preproghrelin gene products in the control of body physiology except energy homeostasis, limited knowledge is available so far. Several lines of evidence, however, show the interplay of ghrelin between metabolism and reproduction. In rat and human, the distribution of ghrelin receptor GHSRs (GHSR1a and GHSR1b) has been confirmed not only in the hypothalamus and pituitary which were originally postulated as target of ghrelin but also in the testis and ovary. Expression of the preproghrelin gene in the brain and gonads was also verified, suggesting the local role (s) of ghrelin in HPG axis. Ghrelin might play a negative modulator in the secretions of hypothalamic GnRH, pituitary gonadotropins and gonadal steroids though the action on pituitary is still questionable. Recent studies suggest the involvement of ghrelin in regulation of puberty onset and possibly of menopause entry. It is now evident that ghrelin is a crucial hormomal component in 'brain-gut' axis, and is a strong candidate links between metabolism and reproduction. Opposite to that for leptin, ghrelin signaling is likely representing the 'hunger' state of body energy balance and is necessary to avoid the energy investment into reproduction which has not a top priority in maintaining homeostasis. Further researches are needed to gain a deep insight into the more precise action mechanism and role of ghrelin in reproduction, and to guarantee the successful biomedical applications.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.4 no.2
• /
• pp.213-217
• /
• 2001

Purpose: Glycogen storage disease type Ia (GSD Ia) is an autosomal recessive disorder of glycogen metabolism caused by glucose-6-phosphatase (G6Pase) deficiency. The clinical manifestations of G6Pase deficiency include growth retardation, hepatomegaly, hypoglycemia, lactic acidemia, hyperlipidemia and hyperuricemia. Many mutations of this gene have been found worldwide in various ethnic groups, establishing the molecular basis of GSD Ia. To elucidate a spectrum of the G6Pase gene mutations in Korean, we analyzed mutations in Korean patients with GSD Ia. Methods: Both alleles of 9 unrelated GSD 1a patients were studied by PCR and direct DNA sequencing methods. In all patients, GSD 1a was diagnosed by the enzyme assay for the liver biopsy specimen. Results: In Korean, the most prevalent mutation was g727t substitution in exon 5, which has been reported to cause abnormal mRNA splicing: Sixteen out of 18 alleles were found to have this mutation. In addition, we identified one novel mutation, a c611g, converting a proline to an alanine at codon 178. Conclusion: Our findings suggest that a screening for the g727t mutation by noninvasive molecular method can detect most cases of GSD Ia in Korean patients.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.16 no.2
• /
• pp.109-114
• /
• 2016

Carbamoyl phosphate synthetase 1 (CPS1) deficiency is an autosomal recessive urea cycle disorder which causes hyperammonemia. CPS1 is the first enzyme step in the urea cycle and almost patients present their symptoms during neonatal period. We report a case of CPS1 deficiency in a boy who developed symptoms including lethargy and seizure at 3 days of age. The ammonia level was up to $2,325{\mu}mol/L$, sodium benzoate (250 mg/kg/d) and high calories of both dextrose and lipid was promptly administered. Central access by experienced pediatric surgeon and emergent continuous hemodialysis by pediatric nephrologist was performed within 3 hours and ammonia was less than $100{\mu}mol/L$ at 5 days of age. Currently, he has showed excellent response to treatments including scavenging drugs and a low-protein diet. Despite of diffuse increasing signal intensity on cerebral white matters and basal ganglia on brain MRI, his development and weight gain were good at the last follow-up at 11 months of age. Molecular assay of the CPS1 gene demonstrated that patient had compound heterozygous for c.1529del ($p.Gly510Alafs^*5$) in exon 14 and c.3142-1G>C (IVS25(-1)G>C) in intron 25 and exon 26 boundary. The splicing mutation was novel mutation and inherited from patient's mother. Here, we report a neonatal lethal type CPS1 deficiency patient having novel mutation.

• Korean Journal of Animal Reproduction
• /
• v.20 no.4
• /
• pp.371-378
• /
• 1997

Human lactoferrin (hLF) was expressed in the mammary gland of transgenic mice. Expresion of hLF was achieved by palcing its cDNA under the control of bovine $\beta$-casein gene. To improve the hLF expression level, two artificial introns were introduced into the expression vector. One intron is a hybrid-splice consisting of bovine $\beta$ casein intron 1 and rabbit $\beta$-casem intron II. The other intron is a DNA fragment spanning intron 8 of bovine $\beta$ casein gene. Trans sgenic mice were developed which expressed hLF in their milk. Twenty lines of transgenic mice were produced. hLF was present in the milk at concentrations of 1 ~ 200 ${\mu}\textrm{g}$ / ml. hLF RNA was only detected in the mammary gland of transgenic mice. The expressed RNA was cor r rectly spliced at the exon /intron junctions. To generate transgenic cows secreting active hLF in their milk, we transferred the DNA-injected bovine embryos to recipient heifers by surgical a and non-surgical methods out of 68 embryos transferred to 51 recipients by surgical or non-surgical method, 7 calves were normally born. Effect of embryo quality of DNA-injected blastocysts on pregnancy rate after transfer was investig a ated. Higher pregnancy rate of (38.9%) DNA-injected embryos was shown in excellent embryos. Pregnancy rates in the groups of good a and fair embryos were 15.4 and 14.3%, respectively. Effect of culture period of DNA-injected b bovine embryos on pregnancy rate after transfer was investigated. When Day-6 blastocysts of cuI ture were transferred, there was no pregnancy. Pregnancy rates of Day-7 and -8 blastocysts were 28.6 and 33.3%, respectively. There was no difference on pregnancy rate between Day-7 a and -8 bovine blastocysts after DNA injection. Thus, we established the techniques for transfer a and culture of DNA-injected bovine embryos. In a addition, factors affecting the pregnancy rate of DNA-injected embryos after transfer were investigated .

• Journal of the Korea Concrete Institute
• /
• v.16 no.5 s.83
• /
• pp.687-696
• /
• 2004

It has been known that practically unavoidable lap splices of longitudinal reinforcement in the plastic hinge region have a bad effect on the seismic performance of reinforced concrete bridge columns. Lap splices were usually located in the plastic hinge region of most bridge columns designed before the implementation of the new seismic design provisions of 1992 Korea Bridge Design specification. The objective of this research is to evaluate the seismic performance of full-sized reinforced concrete bridge piers with lap splice of longitudinal reinforcement in the plastic hinge region, and to develop an appropriate lateral confinement concept of RC bridge columns with lap-spliced longitudinal steels in low or moderate seismicity region. Eight test specimens in the aspect ratio of 4.0 were made with three types of lap splicing, two levels of confinement steel ratios and two types of tie configurations. It was confirmed from the Quasi-Static test that displacement ductility ratios were significantly reduced for nonseismic test columns with lap spliced longitudinal steels but were satisfied the seismic requirement for limited ductile design specimens. As a conclusion, pertinent lateral confinement content was proposed for the seismic. performance of RC bridge piers with $50\%$ lap-spliced longitudinal reinforcing steels in low or moderate seismicity region.

• Journal of Life Science
• /
• v.14 no.6 s.67
• /
• pp.1009-1017
• /
• 2004

Sialyltransferases cloned so far show the remarkable tissue-specific expression, which is correlated with the existence of cell type-specific sialylated sugar structure in glycoconjugates. In the previous studies, we found various mRNA isoforms of human sialyltransferases generated by alternative splicing and alternative promoter utilization. To understand the regulatory mechanisms for specific expression of human sialyltransferase genes and for production of their mRNA isoforms, in this study, we have isolated and characterized five kinds of human sialyltransferase genes: hST3Gal II, hST8Sia II, hST8Sia III, hST8Sia IV, and hST8Sia V. The hST3Gal II gene is composed of six exons, which span over 17kb, with exons ranging in size from 46 to over 1017 bp. The hST8Sia III gene comprises over 10 kb, and consists of only four exons, which is much smaller and simpler than other human sialyltransferase genes. In contrast, three genes (hST8Sia II, hST8Sia IV and hST8Sia V) span more than 70 kb, and comprise five or more exons. All exon-intron boundaries follow the GT-AG rule. In particular, the sialylmotif L, which is a highly conserved region in all cloned sialyltransferases, was found in one exon of hST8Sia III, whereas this motif is encoded by discrete exons in the other human sialyltransferases. Exon structures of these sialyltransferase genes show the structural diversity, as found in other human sialyltransferase genes reported so far. We determined the transcription start site of hST3Gal II gene by the 5'-RACE and cap site hunting experiments.

• Journal of Life Science
• /
• v.20 no.12
• /
• pp.1820-1828
• /
• 2010

Cobalt(II) chloride, a chemical compound with the formula$CoCl_2$, has been widely used in the treatment of anemia, as a chemical agent for the induction of hypoxia in cell cultures, and is known to activate hypoxic signaling. However, excessive exposure to cobalt is associated with several clinical conditions, including asthma, pneumonia, and hematological abnormalities, and can lead to tissue and cellular toxicity. It is also known to induce apoptosis. One of the questions was that of whether $CoCl_2$ might induce apoptosis via endoplasmic reticulum (ER) stress in neurons. To address this question, first, the level of DNA fragmentation was measured for assay of apoptotic rates using $CoCl_2$ with neuron PC12 cells. After confirmation of apoptosis inductions, under the same conditions, the expression levels of ER stress associated factors [ER chaperones Bip, calnexin, ERp72, ERp29, PDI, and ER membrane kinases (IRE1, ATF6, PERK)] were examined by RT-PCR and Western blotting. These results indicated that apoptosis is induced through activation of ER membrane kinases via ER stress. In conclusion, during induction of apoptosis through $CoCl_2$-induced hypoxia in neuron PC12 cells, ER membrane kinase of IRE1 was dominantly up-expressed, and, consecutively, TRAF2, which has been suggested to be one of the links connecting apoptosis and ER stress, was strongly up-expressed.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.3
• /
• pp.56-63
• /
• 2006

In order to evaluate the mechanism of cellulose hydrolysis, the complementary DNA encoding Glycoside Hydrolase Family (GHF)74 was cloned from Phanerochaete chrysosporium. Depending on the presence of Cellulose Binding Module (CBM), it can be classified as GHF74A or GHF74B. The GHF74A gene from P. chrysosporium (PcGHF74A) consists of 2163 bp encoding a protein of 721 amino acid residues. The PcGHF74A showed homology of 70~77% compared with the GHF74 from other filamentous fungi. The PcGHF74B, which contains CBM and is a member of family 1, was transcribed to various transcripts depending on the nature of carbon sources and their concentration. To study the possible presence of splice variants in GHF74B transcripts in P. chrysospoium, we carried out RT-PCR analysis using primers that designed based on the annotation data and sequenced data. Our result indicated that PcGHF74B was transcribed to several splicing variants in various culture conditions. Especially in the culture of 2% cellulose, three transcript products were observed. First transcript was presumed to be a full length ORF that contained 11th intron with stop codon at position 2562 bp. The second one consisted of 12 exons and 11 introns with stop codon at position 1187 bp with 7th exon. The shortest transcript consisted of 10 exons and 9 introns with stop codon at 910 bp in the 7th exon. These premature stop codon might prevent the synthesis of fully active GHF74 or contribute for the production of protein with distinct function depending on the ambient carbon sources.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.4
• /
• pp.366-373
• /
• 2011

We characterized the proteomes of murine N2a cells following infection with three rabies virus (RV) strains, characterized by distinct virulence phenotypes (i.e., virulent BD06, fixed CVS-11, and attenuated SRV9 strains), and identified 35 changes to protein expression using two-dimensional gel electrophoresis in whole-cell lysates. The annotated functions of these proteins are involved in various cytoskeletal, signal transduction, stress response, and metabolic processes. Specifically, a-enolase, prx-4, vimentin, cytokine-induced apoptosis inhibitor 1 (CIAPIN1) and prx-6 were significantly up-regulated, whereas Trx like-1 and galectin-1 were down-regulated following infection of N2a cells with all three rabies virus strains. However, comparing expressions of all 35 proteins affected between BD06-, CVS-11-, and SRV9-infected cells, specific changes in expression were also observed. The up-regulation of vimentin, CIAPIN1, prx-4, and 14-3-3 ${\theta}/{\delta}$, and down-regulation of NDPK-B and HSP-1 with CVS and SRV9 infection were ${\geq}2$ times greater than with BD06. Meanwhile, Zfp12 protein, splicing factor, and arginine/serine-rich 1 were unaltered in the cells infected with BD06 and CVS-11, but were up-regulated in the group infected with SRV9. The proteomic alterations described here may suggest that these changes to protein expression correlate with the rabies virus' adaptability and virulence in N2a cells, and hence provides new clues as to the response of N2a host cells to rabies virus infections, and may also aid in uncovering new pathways in these cells that are involved in rabies infections. Further characterization of the functions of the affected proteins may contribute to our understanding of the mechanisms of RV infection and pathogenesis.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.8
• /
• pp.1133-1142
• /
• 2014

Interleukin-32 (IL-32) is a cytokine and inducer of various proinflammatory cytokines such as $TNF{\alpha}$, IL-$1{\beta}$, and IL-6 as well as chemokines. There are five splicing variants (${\alpha}$, ${\beta}$, ${\gamma}$, ${\delta}$, and ${\varepsilon}$) and IL-$32{\gamma}$ is the most active isoform. We generated human IL-$32{\gamma}$ transgenic (IL-$32{\gamma}$ TG) mice to express high level of IL-$32{\gamma}$ in various tissues, including immune cells. The pathology of sepsis is based on the systemic inflammatory response that is characterized by upregulating inflammatory cytokines in whole body, particularly in response to gram-negative bacteria. We investigated the role of IL-$32{\gamma}$ in a mouse model of experimental sepsis by using lipopolysaccharides (LPS). We found that IL-$32{\gamma}TG$ mice resisted LPS-induced lethal endotoxemia. IL-$32{\gamma}$ reduced systemic cytokines release after LPS administration but not the local immune response. IL-$32{\gamma}TG$ increased neutrophil influx into the initial foci of the primary injected site, and prolonged local cytokines and chemokines production. These results suggest that neutrophil recruitment in IL-$32{\gamma}TG$ occurred as a result of the local induction of chemokines but not the systemic inflammatory cytokine circulation. Together, our results suggest that IL-$32{\gamma}$ enhances an innate immune response against local infection but inhibits the spread of immune responses, leading to systemic immune disorder.