• Title/Summary/Keyword: Degradation pathway

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The Association of Neonatal Hyperbilirubinemia with UGT1A1 and CYP1A2 Gene Polymorphism in Korean Neonates (한국인의 신생아 황달과 UGT1A1 및 CYP1A2 유전자 다형성과의 연관성)

  • Kang, Hoon;Lim, Jun Ho;Kim, Ji Sook;Kim, Eun Ryoung;Kim, Sung Do;Lee, Hee Jae;Chung, Joo Ho
    • Clinical and Experimental Pediatrics
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    • v.48 no.4
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    • pp.380-386
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    • 2005
  • Purpose : The incidence of nonphysiologic neonatal hyperbilirubinemia is twice as high in East Asians as in whites. Recently, UGT1A1 mutation was found to be a risk factor for neonatal hyperbilirubinemia. In congenitally-jaundiced Gunn rats, which lack expression of UDP-glucuronosyltransferase, alternative pathways can be stimulated by inducers of CYP1A1 and CYP1A2 enzymes. CYP1A2 plays a major role in bilirubin degradation of the alternate pathway. We studied the relationship between UGT1A1 and CYP1A2 gene polymorphism of neonatal hyperbilirubinemia in Koreans. Methods : Seventy-nine Korean full term neonates who had hyperbilirubinemia(serum bilirubin >12 mg/dL) without obvious causes of jaundice, were analyzed for UGT1A1 and CYP1A2 gene polymorphism; the control group was sixty-eight. We detected the polymorphism of Gly71Arg of UGT1A1 gene by direct sequencing and T2698G of CYP1A2 by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) using MboII and direct sequencing. Results : Allele frequency of Gly71Arg mutation in the hyperbilirubinemia group was 32 percent, which was significantly higher than 11 percent in the control group(P<0.0001). Mutant gene frequency of T2698G was 41.8 percent in patients and 32.3 percent in the control group(P=0.015), but allele frequency was 21 percent in patients and 19 percent in the control group, which was not significantly higher(P=0.706). There was no relationship between mutations of two genes(P=0.635). Conclusion : The polymorphism of UGT1A1 gene(Gly71Arg) and CYP1A2 gene(T2698G) was detected in Korean neonatal hyperbilirubinemia. Only polymorphisms of Gly71Arg in UGT1A1 were significantly higher than control group.

Ethanol Extract of Mori Folium Inhibits AICAR-induced Muscle Atrophy Through Inactivation of AMPK in C2C12 Myotubes (C2C12 근관세포에서 상엽에 의한 AMPK의 불활성화와 AICAR로 유도된 근위축 억제의 연관성에 관한 연구)

  • Lee, Yu Sung;Kim, Hong Jae;Jeong, Jin-Woo;Han, Min-Ho;Hong, Su Hyun;Choi, Yung Hyun;Park, Cheol
    • Journal of Life Science
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    • v.28 no.4
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    • pp.435-443
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    • 2018
  • AMP-activated protein kinase (AMPK) functions as a metabolic master through regulating and restoring cellular energy balance. In skeletal muscle, AMPK increases myofibril protein degradation through the expression of muscle-specific ubiquitin ligases. Mori Folium, the leaf of Morus alba, is a traditional medicinal herb with various pharmacological functions; however, the effects associated with muscle atrophy have not been fully identified. In this study, we confirmed the effects of AMPK activation by examining the effects of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an activator of AMPK, on the induction of atrophy and expression of atrophy-related genes in C2C12 myotubes. We also investigated the effects of the ethanol extract of Mori Folium (EEMF) on the recovery of AICAR-induced muscle atrophy in C2C12 myotubes. It was found that exposure to AICAR resulted in the stimulation of Forkhead box O3a (FOXO3a); an up-regulation of muscle-specific ubiquitin ligases such as Muscle Atrophy F-box (MAFbx)/atrogin-1 and muscle RING finger-1 (MuRF1), and a down-regulation of muscle-specific transcription factors, such as MyoD and myogenin; with the activation of AMPK. In addition, AICAR without cytotoxicity indicated a decrease in diameter of C2C12 myotubes. However, treatment with EEMF significantly suppressed AICAR-induced muscle atrophy of C2C12 myotubes in a dose-dependent manner as confirmed by a decrease in myotube diameter, which is associated with a reversed stimulation of FOXO3a by the inhibition of AMPK activation. These results indicate that the activation of AMPK by AICAR induces muscle atrophy, and EEMF has preeminent effects on the inhibition of AICAR-induced muscle atrophy through the AMPK signaling pathway.

Sagantang-induced Apoptotic Cell Death is Associated with the Activation of Caspases in AGS Human Gastric Carcinoma Cells (사간탕 처리에 의한 AGS 인체 위암세포의 caspase 활성 의존적 apoptosis 유발)

  • Park, Cheol;Hong, Su Hyun;Choi, Sung Hyun;Lee, Se-Ra;Leem, Sun-Hee;Choi, Yung Hyun
    • Journal of Life Science
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    • v.25 no.12
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    • pp.1384-1392
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    • 2015
  • Sagantang (SGT), a Korean multiherb formula comprising six medicinal herbs, Paeonia lactiflora Pall., Belamcanda chinensis (L.) DC, Gardenia jasminoides Ellis, Poria cocos Wolf, Cimicifuga heracleifolia Komarov, and Artractylodes japonica Koidzumi, was recorded in “Dongeuibogam.” The present study investigated the anticancer potential of SGT in AGS human gastric carcinoma cells. The results indicated that SGT treatment significantly inhibited the growth and viability of AGS cells in a dose-dependent manner, which was associated with the induction of apoptotic cell death, as evidenced by the formation of apoptotic bodies, in addition to chromatin condensation and DNA fragmentation, and the accumulation of annexin-V positive cells. The induction of apoptotic cell death by the SGT treatment was associated with up-regulation of Fas protein expression, truncation of Bid, and down-regulation of the anti-apoptotic Bcl-2 protein. The SGT treatment also effectively induced the loss of mitochondrial membrane potential, which was associated with the activation of caspases (caspase-3, -8, and -9) and degradation of poly (ADP-ribose) polymerase. However, a pan-caspase inhibitor significantly blocked the SGT-induced apoptosis and growth suppression in AGS cells. This study suggests that SGT induces caspase-dependent apoptosis through an extrinsic pathway by upregulating Fas, as well as through an intrinsic pathway by modulating Bcl-2 family members in AGS cells. The results suggest that SGT may be a potential chemotherapeutic agent for the control of human gastric cancer cells. However, further studies will be needed to confirm the potential of SGT in cancer prevention and therapy in an in vivo model and to identify biological active compounds of SGT.

Induction of Apoptosis by Water Extract of Glycyrrhizae radix in Human Bladder T24 Cancer Cells (인체 방광암 T24 세포에서 감초(Glycyrrhizae radix) 열수추출물에 의한 apoptosis 유도)

  • Lee, Ki Won;Kim, Jeong Il;Lee, Seung Young;Choi, Kyung-Min;Oh, Young Taek;Jeong, Jin-Woo
    • Korean Journal of Plant Resources
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    • v.32 no.4
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    • pp.255-263
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    • 2019
  • Glycyrrhizae radix is one of the most frequently prescribed ingredients in Oriental medicine, and Glycyrrhizae radix extract has been shown to exert anti-cancer effects. However, the cellular and molecular mechanisms of programed cell death (apoptosis) by Glycyrrhizae radix are poorly defined. In the present study, it was examined the molecular mechanisms of apoptosis by water extracts of Glycyrrhizae radix (GRW) in human bladder T24 cancer cells. It was found that GRW could inhibit the cell growth of T24 cells in a concentration-dependent manner, which was associated with the induction of apoptotic cell death, as evidenced by the formation of apoptotic bodies, DNA fragmentation and increased populations of annexin-V positive cells. The induction of apoptotic cell death by GRW was connected with an up-regulation of pro-apoptotic Bax protein expression and down-regulation of anti-apoptotic proteins (Bcl-2 and Bcl-xL), and inhibition of apoptosis family proteins (XIAP, cIAP-1 and cIAP-2). In addition, apoptosis-inducing concentrations of GRW induced the activation of caspase-9, an initiator caspase of the mitochondrial-mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of PARP. GRW also induced apoptosis via a death receptor-mediated extrinsic pathway by caspase-8 activation, resulting in the down-regulation of total Bid and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. Taken together, the present results suggest that GRW may be a potential chemotherapeutic agent for the control of human bladder cancer cells.

A Novel Chenodeoxycholic Derivative HS-1200 Induces Apoptosis in Human HT-29 Colon Cancer Cells (인체 대장암 세포주(HT-29)에서 담즙산 합성유도체(HS-1200)의 세포 사망 기전)

  • Oh Sin Geun;Yang Kwang Mo;Hur Won Joo;Yoo Young Hyun;Suh Hong Suk;Lee Hyung Sik
    • Radiation Oncology Journal
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    • v.20 no.4
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    • pp.367-374
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    • 2002
  • Purpose : To investigate the growth inhibitory effects, and the underlying mechanism of human colon cancer cell (HT-29) death, induced by a new synthetic bile acid derivative (HS-1200). Materials and Methods : Human colon cancer cells (HT-29), in exponential growth phase, were treated with various concentrations of a new synthetic bile acid derivative (HS-1200). The growth inhibitory effects on HT-29 cells were examined using a frypan blue exclusion assay. The extent of apoptosis was determined using agarose gel electrophoresis, TUNEL assays and Hoechst staining. The apoptotic cell death was also confirmed by Western blotting of PARP, caspase-3 and DNA fragmentation factor (DFF) analysis. To investigate the involvement of mitochondria, we employed immunofluorescent staining of cytochrome c and mitochondrial membrane potential analyses. Results : The dose required for the half maximal inhibition $(IC_{50})$ of the HT-29 cell growth was $100\~150\;{\mu}M$ of HS-1200. Several changes, associated with the apoptosis of the HT-29 cells, were reveal by the agarose gel eletrophoresis, TUNEL assays and Hoechst staining, following their treatment with $100\;{\mu}M$ of HS-1200. HS-1200 treatment also induced caspase-3, PARP and DFF degradations, and the western blotting showed the processed caspase-3 p20, PARP p85 and DFF p30 and p11 cleaved products. Mitochondrial events were also demonstrated. The cytochrome c staining indicated that cytochrome c had been released from the mitochondria in the HS-1200 treated cells. The mitochondrial membrane potential $(\Delta\Psi_m)$ was also prominently decreased in the HS-1200 treated cells. Conclusion : These findings suggest that the HS-1200 - induced apoptosis of human colon cancer cells (HT-29) is mediated via caspase and mitochondrial pathways.

Tumor-suppressor Protein p53 Sensitizes Human Colorectal Carcinoma HCT116 Cells to 17α-estradiol-induced Apoptosis via Augmentation of Bak/Bax Activation (17α-Estradiol에 의한 인체 대장암 세포주 HCT116의 에폽토시스에 수반되는 Bak/Bax의 활성화에 미치는 종양억제단백질 p53의 강화효과)

  • Han, Cho Rong;Lee, Ji Young;Kim, Dongki;Kim, Hyo Young;Kim, Se Jin;Jang, Seokjoon;Kim, Yoon Hee;Jun, Do Youn;Kim, Young Ho
    • Journal of Life Science
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    • v.23 no.10
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    • pp.1230-1238
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    • 2013
  • The regulatory effect of the tumor-suppressor protein p53 on the apoptogenic activity of $17{\alpha}$-estradiol ($17{\alpha}-E_2$) was compared between HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells. When the HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$) cells were treated with $2.5{\sim}10{\mu}M$ $17{\alpha}-E_2$ for 48 h or with $10{\mu}M$for various time periods, cytotoxicity and an apoptotic sub-$G_1$ peak were induced in the HCT116 ($p53^{+/+}$) cells in a dose- and time-dependent manner. However, the HCT116 ($p53^{-/-}$) cells were much less sensitive to the apoptotic effect of $17{\alpha}-E_2$. Although $17{\alpha}-E_2$ induced aberrant mitotic spindle organization and incomplete chromosome congregation at the equatorial plate, $G_2/M$ arrest was induced to a similar extent in both cell types. In addition, $17{\alpha}-E_2$-induced activation of Bak and Bax, ${\Delta}{\Psi}m$ loss, and PARP degradation were more dominant in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells. In accordance with enhancement of p53 phosphorylation (Ser-15) and p53 levels, p21 and Bax levels were elevated in the HCT116 ($p53^{+/+}$) cells treated with $17{\alpha}-E_2$. The HCT116 ($p53^{-/-}$) cells exhibited barely or undetectable levels of p21 and Bax, regardless of $17{\alpha}-E_2$ treatment. On the other hand, although the level of Bcl-2 was slightly lower in the HCT116 ($p53^{+/+}$) than in the HCT116 ($p53^{-/-}$) cells, it remained relatively constant after the $17{\alpha}-E_2$ treatment. Together, these results show that among the components of the $17{\alpha}-E_2$-induced apoptotic-signaling pathway, which proceeds through mitotic spindle defects causing mitotic arrest, subsequent activation of Bak and Bax and the mitochondria-dependent caspase cascade, leading to PARP degradation, $17{\alpha}-E_2$-induced activation of Bak and Bax is the upstream target of proapoptotic action of p53.

Differential Effects of Acute and Chronic Exercise on Autophagy-related Gene Expression in Drosophila melanogaster (일회성 및 만성적 유산소운동이 초파리의 자가포식 관련 유전자 발현에 미치는 영향)

  • Kim, Hee Yeon;Kim, Hye Jin;Hwang, Ji Sun;Lee, Won Jun
    • Journal of Life Science
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    • v.24 no.11
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    • pp.1180-1186
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    • 2014
  • Autophagy, the lysosomal degradation pathway, is an intracellular recycling system that is necessary for the metabolic benefits of exercise and for producing lasting beneficial effects of exercise in various diseases. However, the most recent studies have only examined the effect of a single bout of exercise or resistance exercise on autophagic responses. To determine the differential effects of acute and chronic exercise on the expression of autophagy-related genes in D. melanogaster, white-eyed mutant D. melanogaster were assigned randomly to four groups: control, acute exercise, 2 hr chronic exercise, and 3 hr chronic exercise. The flies were exercised using a mechanized platform known as the Power Tower. Our results revealed that a single bout of exercise resulted in increased mRNA levels of the Atg8a gene (~20%, p<0.05). However, Atg1 and Atg6 mRNA expression were not induced by acute exercise. Transcript levels of Atg6 (~29%, p<0.05) related to the nucleation of autophagosomes were significantly induced by 2 hr of chronic exercise. However, this chronic exercise was not enough to increase Atg1 and Atg8a mRNA expression. On the other hand, 3 hr of exercise for 7 days significantly increased Atg1, Atg6, and Atg8a gene expression-about 57%, 37%, and 71%, respectively (p<0.05). These results suggest that a single bout of exercise is not enough to induce full activation of selected autophagy-related genes in D. melanogaster. Our results demonstrated that chronic regular exercise induced autophagy-related gene expression, suggesting that chronic regular exercise training might be required to activate autophagic responses important for producing beneficial effects of exercise in various diseases.

Anti-Inflammmatiry Effects of Nerium indicum Ethanol Extracts through Suppression of NF-kappaB Activation (NF-κB 활성 저해를 통한 협죽도 에탄올 추출물의 항염증 효능)

  • Kim, Tae-Hwan;Ko, Seog-Soon;Park, Cheol;Park, Sang-Eun;Hong, Sang-Hoon;Kim, Byung-Woo;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.20 no.8
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    • pp.1221-1229
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    • 2010
  • Nerium indicum, an India-Pakistan-originated shrub belonging to the oleander family, is reported to possess many pharmacological activities including cardiac muscle stimulation, and anti-diabetes, anti-angiogenesis, anti-cancer and neuro-protective activities. However, the anti-inflammatory properties of N. indicum were unclear. In this study, we investigated the effects of ethanol extract of the N. indicum leaf and stem (ENIL and ENIS) on the expression of anti-inflammatory mediators in U937 human pre-monocytic cell models. In U937 cells stimulated with phorbol 12-myristate-13-acetate (PMA), pre-treatment with ENIS significantly inhibited the expression of both cyclooxygenase-2 (COX-2) mRNA and protein, which are associated with inhibition of the release of prostaglandin $E_2\;(PGE_2)$, whereas the inhibitory effects appeared weakly in ENIL. Moreover, ENIS significantly attenuated PMA-induced IkappaB ($I{\kappa}B$) degradation and suppressed elevated nuclear factor kappa B (NF-${\kappa}B$) nuclear translocation. Taken together, these findings provide important new insights that N. indicum exhibits anti-inflammatory properties by suppressing the transcription of pro-inflammatory cytokine genes through the NF-kB signaling pathway.

Inhibitory Effect of Camp Antagonist and Pka Inhibitors, and Stimulatory Effect of Adenylate Cyclase Agonist on Cathepsin K Processing in Cultured Mouse Osteoclasts (cAMP 길항제와 PKA 억제제 및 Adenylate Cyclase 촉진제의 백서 파골세포에서 Cathepsin K 생성에 대한 효과)

  • Shim, Youn-Soo
    • Journal of dental hygiene science
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    • v.6 no.1
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    • pp.1-9
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    • 2006
  • Cathepsin K (cat K) is the major cysteine protease expressed in osteoclasts and was thought to play a key role in matrix degradation during bone resorption. It was shown that the intracellular maturation of cat K was prevented by the cAMP antagonist, Rp-cAMP, and the protein kinase A (PKA) inhibitors of KT5720 and H89. In contrast, forskolin, a adenylate cyclase agonist, rather induced Cat K processing and maturation in osteoclasts. Furthermore, to determine whether cat K processing and maturation signaling involves protein kinase C (PKC), mouse total bone cells were treated with calphostin C, a specific inhibitor of PKC, however, no effect was observed, indicating that calphostin C did not affect to osteoclast-mediated cat K processing and maturation. Thus, it is indicated that the cAMP-PKA signaling pathway regulates cat K maturation in osteoclasts. Since secreted proenzymes have the potential to reenter the cell via M6P receptor, to prevent this possibility, it was tested cAMP antagonist Rp-cAMP and the PKA inhibitors KT5720 and H89 in the absence or presence of M6P. Inhibition of cat K processing by Rp-cAMP, KT5720, or H89 was observed in a dose-dependent manner. Furthermore, the addition of M6P resulted in enhanced potency of Rp-cAMP, KT5720 and H89. These dose-dependently inhibited in vitro bone resorption with a potency similar to that observed for inhibition of cat K processing.

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Effect of Steroid Administration Ex Vivo on the IκB/NF-κB Pathway in Human Peripheral Blood Monocytes (스테로이드의 투여가 말초혈액 단핵구에서 IkB/NF-κB경로에 미치는 영향)

  • Yoon, Ho Il;Lee, Hee-Seok;Lee, Chang-Hoon;Lee, Choon-Taek;Kim, Young Whan;Han, Sung Koo;Shim, Young-Soo;Yoo, Chul-Gyu
    • Tuberculosis and Respiratory Diseases
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    • v.54 no.5
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    • pp.542-550
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    • 2003
  • Background : Synthetic glucocorticoids are widely used in many chronic inflammatory diseases because of their excellent anti-inflammatory activity. Enhancing the transcription of $I{\kappa}B$ and preventing activated NF-${\kappa}B$ from binding to ${\kappa}B$ sites are thought to be the underlying mechanisms. But these data are largely derived from in vitro studies using cell lines. In this study, after administrating a steroid to volunteers, we evaluated the effect on the NF-${\kappa}B$ system. Methods : Prednisolone(0.5mg/kg/d) was orally administered to 5 healthy volunteers for 7 days. Before and after the administration, we sampled their peripheral blood monocytes, and performed western blot analysis both with stimulation, using IL-$1{\beta}$, LPS, TNF, and without stimulation(baseline). We also performed EMSA after stimulation with LPS. Results : After ingestion of the steroid, baseline expressions of $I{\kappa}B{\alpha}$ were increased in two of the subjects, while suppressed degradations of $I{\kappa}B{\alpha}$ to stimulations were observed in all five. In addition, the binding capacity of NF-${\kappa}B$ after the administration was decreased. Conclusion : Steroid plays such roles as enhancing the transcription of $I{\kappa}B{\alpha}$, suppressing the DNA binding capacity of NF-${\kappa}B$, and suppressing the degradation of $I{\kappa}B{\alpha}$.