• Journal of Life Science
• /
• v.19 no.4
• /
• pp.520-525
• /
• 2009

Early onset of Batten disease (EBD), one of the most lethal neurodegenerative storage disorders of childhood, is caused by inactivating mutations in the Ceroid Lipofuscinosis, Neuronal (CLN1) gene. Neurogranin, a calmodulin-binding protein, is expressed in the brain and participates in the protein kinase C (PKC) signaling pathway. While oxidative stress is the suggested cause of neurodegeneration in EBD, its molecular mechanism(s) remains obscure. In this research, we examined the levels of neurogranin in the brain mRNA of wild-type (WT) mice and EBD knockout (KO) mice, as well as the proteins. We also performed neuronal cultures to measure the expression levels of neurgranin and phosphorylated-neurogranin with or without oxidative stress inducers and anti-oxidants. Results showed that neurogranin in both EBD KO mice brain mRNA and protein extracts decreased in an age dependent manner. However, high amounts of phosphorylated-neurogranin were detected in the 6-month brain. This pattern was also confirmed by cultured neurospheres samples. Moreover, neurospheres treated with $H_2O_2$, an oxidative stress inducer, showed increased phosphorylated-neurogranin patterns. Interestingly, this pattern returned to normal status when treated with N-acetyl-L-cystein, an anti-oxidant, after $H_2O_2$ treatment was performed. Our results suggest that the phosphorylation of neurogranin is affected by oxidative stress status in EBD, and appropriate anti-oxidant treatment will relieve hyper-phosphorylation of neurogranin.

• Journal of Life Science
• /
• v.22 no.2
• /
• pp.142-147
• /
• 2012

The sporulation-specific glucoamylase (SGA) of Saccharomyces diastaticus is known to be produced in the cytoplasm during sporulation. For the purpose of proving that SGA has secretory potential, we constructed a hybrid plasmid, pYESC25, containing the promoter and the putative signal sequence of the SGA fused in frame to the endo-1,4-${\beta}$-D-glucanase (CMCase) gene of Bacillus subtilis without its own signal sequence. The recipient yeast strain of S. diastaticus YIY345 was transformed with the hybrid plasmid. CMCase secretion from S. diastaticus harboring pYESC25 into culture medium was confirmed by the formation of yellowish halos around transformants after staining with Congo red on a CMC agar plate. The transformant culture was fractionated to the extracellular, periplasmic, and intracellular fraction, followed by the measurement of CMCase activity. About 63% and 13% enzyme activity were detected in the culture supernatant (extracellular fraction) and periplasmic fraction, respectively. Furthermore, ConA-Sepharose chromatography, native gel electrophoresis, and activity staining revealed that CMCase produced in yeast was glycosylated and its molecular weight was larger than that of the unglycosylated form from B. subtilis. Taking these findings together, SGA has the potential of secretion to culture medium, and the putative signal sequence of SGA can efficiently direct bacterial CMCase to the yeast secretion pathway.

• BMB Reports
• /
• v.45 no.3
• /
• pp.183-188
• /
• 2012

Participates in actin remodeling through Rac and receptor endocytosis via Rab5. Here, we used yeast two-hybrid system with Eps8 as bait to screen a human brain cDNA library. ITSN2 was identified as the novel binding factor of Eps8. The interaction between ITSN2 and Eps8 was demonstrated by the in vivo co-immunoprecipitation and colocalization assays and the in vitro GST pull-down assays. Furthermore, we mapped the interaction domains to the region between amino acids 260-306 of Eps8 and the coiled-coil domain of ITSN2. In addition, protein stability assays and immunofluorescence analysis showed ITSN2 overexpression induced the degradation of Eps8 proteins, which was markedly alleviated with the lysosome inhibitor NH4Cl treatment. Taken together, our results suggested ITSN2 interacts with Eps8 and stimulates the degradation of Eps8 proteins.

• Journal of Ginseng Research
• /
• v.44 no.3
• /
• pp.435-441
• /
• 2020

Background: As a process of aging, skeletal muscle mass and function gradually decrease. It is reported that ginsenoside Rb1 and Rb2 play a role as AMP-activated protein kinase activator, resulting in regulating glucose homeostasis, and Rb1 reduces oxidative stress in aged skeletal muscles through activating the phosphatidylinositol 3-kinase/Akt/Nrf2 pathway. We examined the effects of Rb1 and Rb2 on differentiation of the muscle stem cells and myotube formation. Methods: C2C12 myoblasts treated with Rb1 and/or Rb2 were differentiated and induced to myotube formation, followed by immunoblotting for myogenic marker proteins, such as myosin heavy chain, MyoD, and myogenin, or immunostaining for myosin heavy chain or immunoprecipitation analysis for heterodimerization of MyoD/E-proteins. Results: Rb1 and Rb2 enhanced myoblast differentiation through accelerating MyoD/E-protein heterodimerization and increased myotube hypertrophy, accompanied by activation of Akt/mammalian target of rapamycin signaling. In addition, Rb1 and Rb2 induced the MyoD-mediated transdifferentiation of the rhabdomyosarcoma cells into myoblasts. Furthermore, co-treatment with Rb1 and Rb2 had synergistically enhanced myoblast differentiation through Akt activation. Conclusion: Rb1 and Rb2 upregulate myotube growth and myogenic differentiation through activating Akt/mammalian target of rapamycin signaling and inducing myogenic conversion of fibroblasts. Thus, our first finding indicates that Rb1 and Rb2 have strong potential as a helpful remedy to prevent and treat muscle atrophy, such as age-related muscular dystrophy.

• Molecules and Cells
• /
• v.38 no.6
• /
• pp.528-534
• /
• 2015

Hypoxia-inducible factor (HIF) is a key regulator of tumor growth and angiogenesis. Recent studies have shown that, BIX01294, a G9a histone methyltransferase (HMT)-specific inhibitor, induces apoptosis and inhibits the proliferation, migration, and invasion of cancer cells. However, not many studies have investigated whether inhibition of G9a HMT can modulate HIF-$1{\alpha}$ stability and angiogenesis. Here, we show that BIX01294 dose-dependently decreases levels of HIF-$1{\alpha}$ in HepG2 human hepatocellular carcinoma cells. The half-life of HIF-$1{\alpha}$, expression of proline hydroxylase 2 (PHD2), hydroxylated HIF-$1{\alpha}$ and von Hippel-Lindau protein (pVHL) under hypoxic conditions were decreased by BIX01294. The mRNA expression and secretion of vascular endothelial growth factor (VEGF) were also significantly reduced by BIX01294 under hypoxic conditions in HepG2 cells. BIX01294 remarkably decreased angiogenic activity induced by VEGF in vitro, ex vivo, and in vivo, as demonstrated by assays using human umbilical vein endothelial cells (HUVECs), mouse aortic rings, and chick chorioallantoic membranes (CAMs), respectively. Furthermore, BIX01294 suppressed VEGF-induced matrix metalloproteinase 2 (MMP2) activity and inhibited VEGF-induced phosphorylation of VEGF receptor 2 (VEGFR-2), focal adhesion kinase (FAK), and paxillin in HUVECs. In addition, BIX01294 inhibited VEGF-induced formation of actin cytoskeletal stress fibers. In conclusion, we demonstrated that BIX01294 inhibits HIF-$1{\alpha}$ stability and VEGF-induced angiogenesis through the VEGFR-2 signaling pathway and actin cytoskeletal remodeling, indicating a promising approach for developing novel therapeutics to stop tumor progression.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.16 no.2
• /
• pp.57-61
• /
• 2016

Isovaleric acidemia (IVA) is an autosomal recessively inherited organic acid disorder due to a defect of the enzyme isovaleryl-CoA dehydrogenase in the leucine metabolic pathway. Deficiency of this enzyme results in the accumulation of derivatives of isovaleryl-CoA. In acute illness in IVA, isovaleric acid and its derivatives accumulate and profound metabolic acidosis with ketosis, characteristic pungent body odor, hypoglycemia, and hyperammonemia can be developed. Additionally, recurrent vomiting, failure to thrive, developmental delay, epilepsy and mental retardation are chronic presenting symptoms and signs for IVA. On the result of newborn screening for inherited metabolic disorders, increased levels of isovalerylcarnitine (C5) are shown. However, C5 elevation can be accompanied with short/branched-chain acyl-CoA dehydrogenase (SBCAD) and therapy with certain antibiotics containing pivalic acid. Quantitative measurement of organic acids in urine and acylcarnitine profiles in plasma are necessary to differential diagnosis. Molecular genetic analysis of the IVD gene for IVA and ACADSB is also helpful to confirm IVA and SBCAD deficiency, respectively. Considering that IVA can be associated with significant morbidity and mortality at acute presentation of metabolic crisis, early diagnosis prior to the onset of symptoms by newborn screening enable to introduction of early treatment and prevention of acute and chronic complications.

• Journal of Life Science
• /
• v.28 no.7
• /
• pp.778-785
• /
• 2018

Autophagy is a complex signaling process and has been implicated in tumor suppression and anticancer therapy resistance. Autophagy can produce tumor-suppressive effect by inducing autophagic cell death, either in collaboration with apoptosis. In this current study, we found that celecoxib (CCB), a nonsteroidal anti-inflammatory drug (NSAID) with multifaceted effects, induced autophagy including enhanced LC3 conversion (LC3-I to LC3-II) and reduced autophagy substrate protein p62 level in multidrug-resistant (MDR) cancer cells. CCB sensitized human multidrug resistant (MDR) cancer cells to the ansamycin-based HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG), a benzoquinoid ansamycin, which causes the degradation of several oncogenic and signaling proteins, by inducing autophagic cell death and apoptosis. CCB significantly augmented 17-AAG-mediated level of LC3-II/LC-I, indicating the combined effect of 17-AAG and CCB on the induction of autophagy. Autophagic degradation of mutant p53 (mutp53) and activation of caspase-3 in 17-AAG-treated MDR cells were accelerated by CCB. Inhibition of caspase-3-mediated apoptotic pathway by Z-DEVD-FMK, a caspase-3 inhibitor, did not completely block CCB-induced cell death in MCF7-MDR cells. In addition, treatment of MDR cells with Z-DEVD-FMK failed to prevent activation of autophagy by combined treatment with 17-AAG and CCB. Based on our findings, the ability of clinically used drug CCB to induce autophagy has important implications for its development as a sensitizing agent in combination with Hsp90 inhibitor of MDR cancer.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.22 no.6
• /
• pp.1431-1438
• /
• 2008

The marine algae, Padina arborescens, have been used traditionally for treatment of various brain diseases. However, the molecular studies on the effect of Padina arborescens have not been carried out. In the present study, the protective effect of the water extract of Padina arborescens (PAWE) was researched in $H_2O_2$-treated human vascular endothelial cells, ECV304. ECV304 cells were pre-incubated with PAWE (0, 400, 800, 1,200 and $1,600{\mu}g/m{\ell}$) for 12 h and treated with 500 uM $H_2O_2$ for 12 h, and then the protective effects of PAWE were determined. PAWE recovered the $H_2O_2$-induced cell damage and decreased ROS production in ECV304 cells. Moreover, PAWE increased ERK expression and inhibited p38 and JNK expression. Furthermore, PAWE dosedependently increased the expression of heme oxygenase-1 (HO-1) and the HO-1 expression was reduced by ERK inhibitor treatment in $H_2O_2$-treated EVC304 cells. These results suggested that protective effect of PAWE on $H_2O_2$-induced oxidative stress in ECV304 cells might be associated with the production of HO-1 through the ERK signal pathway.

• Parasites, Hosts and Diseases
• /
• v.47 no.3
• /
• pp.205-212
• /
• 2009

Trichomonas vaginalis commonly causes vaginitis and perhaps cervicitis in women and urethritis in men and women. Macrophages are important immune cells in response to T. vaginalis infection. In this study, we investigated whether human macrophages could be involved in inflammation induced by T. vaginalis. Human monocyte-derived macrophages (HMDM) were co-cultured with T. vaginalis. Live, opsonized-live trichomonads, and T. vaginalis Iysates increased proinflammatory cytokines, such as TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 by HMDM. The involvement of nuclear factor (NF)-${\kappa}B$ signaling pathway in cytokine production induced by T. vaginalis was confirmed by phosphorylation and nuclear translocation of p65 NF-${\kappa}B$. In addition, stimulation with live T. vaginalis induced marked augmentation of nitric oxide (NO) production and expression of inducible NO synthase (iNOS) levels in HMDM. However, trichomonad-induced NF-${\kappa}B$ activation and TNF-${\alpha}$ production in macrophages were significantly inhibited by inhibition of iNOS levels with L-NMMA (NO synthase inhibitor). Moreover, pretreatment with NF-${\kappa}B$ inhibitors (PDTC or Bay11-7082) caused human macrophages to produce less TNF-${\alpha}$. These results suggest that T. vaginalis stimulates human macrophages to produce proinflammatory cytokines, such as IL-1, IL-6, and TNF-${\alpha}$, and NO. In particular, we showed that T. vaginalis induced TNF-${\alpha}$ production in macrophages through NO-dependent activation of NF-${\kappa}B$, which might be closely involved in inflammation caused by T. vaginalis.

• BMB Reports
• /
• v.50 no.8
• /
• pp.429-434
• /
• 2017

Endometriosis is the abnormal growth of endometrial cells outside the uterus, causing pelvic pain and infertility. Furthermore, adhesion of endometrial tissue fragments to pelvic mesothelium is required for the initial step of endometriosis formation outside uterus. $TGF-{\beta}1$ and adhesion molecules importantly function for adhesion of endometrial tissue fragments to mesothelium outside uterus. However, the function of $TGF-{\beta}1$ on the regulation of adhesion molecule expression for adhesion of endometrial tissue fragments to mesothelium has not been fully elucidated. Interestingly, transforming growth factor ${\beta}1$ ($TGF-{\beta}1$) expression was higher in endometriotic epithelial cells than in normal endometrial cells. The adhesion efficiency of endometriotic epithelial cells to mesothelial cells was also higher than that of normal endometrial cells. Moreover, $TGF-{\beta}1$ directly induced the adhesion of endometrial cells to mesothelial cells through the regulation of integrin of ${\alpha}V$, ${\alpha}6$, ${\beta}1$, and ${\beta}4$ via the activation of the $TGF-{\beta}1/TGF-{\beta}RI/Smad2$ signaling pathway. Conversely, the adhesion of $TGF-{\beta}1-stimulated$ endometrial cells to mesothelial cells was clearly reduced following treatment with neutralizing antibodies against specific $TGF-{\beta}1-mediated$ integrins ${\alpha}V$, ${\beta}1$, and ${\beta}4$ on the endometrial cell membrane. Taken together, these results suggest that $TGF-{\beta}1$ may act to promote the initiation of endometriosis by enhancing integrin-mediated cell-cell adhesion.