• Title/Summary/Keyword: Enzyme regulation

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Fermented Saccharina japonica (Phaeophyta) improves neuritogenic activity and TMT-induced cognitive deficits in rats

  • Park, Hyun-Jung;Lee, Mi-Sook;Shim, Hyun Soo;Lee, Gyeong-Ran;Chung, Sun Yong;Kang, Young Mi;Lee, Bae-Jin;Seo, Yong Bae;Kim, Kyung Soo;Shim, Insop
    • ALGAE
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    • v.31 no.1
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    • pp.73-84
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    • 2016
  • Marine organisms are frequently used to be harmful and have lower side effects than synthetic drugs. The cognitive improving efficacy of gamma aminobutyric acid-enriched fermented Saccharina japonica (FSJ) on the memory deficient rats, which were induced by trimethyltin chloride (TMT), was investigated by assessing the Morris water maze test and by performing choline acetyltransferase (ChAT), cAMP response element binding protein (CREB), and brain derived neurotrophic factor (BDNF) immunohistochemistry. The neurite outgrowth of Neuro2a cells was assessed in order to examine the underlying mechanisms of the memory enhancing effects of FSJ. Treatment with FSJ tended to shorten the latency to find the platform in the acquisition test of the Morris water maze at the second and fourth day compared to the control group. In the probe trial, the FSJ treated group increased time spent in the target quadrant, compared to that of the control group. Consistent with the behavioral data, these treatments recovered the loss of ChAT, CREB, and BDNF immunepositive neurons in the hippocampus produced by TMT. Treatment with FSJ markedly stimulated neurite outgrowth of the Neuro2a cells as compared to that of the controls. These findings demonstrate that FSJ may be useful for improving the cognitive function via regulation of neurotrophic marker enzyme activity.

Effects of a Caragana sinica Water Extract on Lipid and Glucose Metabolism in Ovariectomized Rats (골담초 열수 추출물의 갱년기 이후 지질 및 당질 대사 개선 효능)

  • Lee, Sang Chul;Chung, Soo Im;Kang, Mi Young
    • Korean Journal of Plant Resources
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    • v.29 no.5
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    • pp.532-538
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    • 2016
  • Menopause is characterized by a decrease in estrogen production by the ovaries. Furthermore, the risk of developing chronic diseases including cardiovascular disease, obesity, and diabetes increases in menopausal women. In this study, we evaluated the ability of Caragana sinica (CS) to affect lipid and glucose metabolism in an ovariectomized Sprague-Dawley rat model of induced menopause. The animals were divwided randomly into three groups: sham-operated rats (SHAM), ovariectomized rats (OVX), and ovariectomized rats treated with 1% water extract of CS (OVX-CS). The OVX-CS treated mice showed a significant decrease in body weight, adipose tissue, triglyceride, and total cholesterol. Improved lipid and glucose profiles were also observed, and were attributed to suppression of hepatic lipogenesis and adipokine production and regulation of glucose-regulating enzyme activity. Therefore, these findings indicate a potential use for CS as a functional food for menopause-induced hyperlipidemia and hyperglycemia.

MiR-26a promotes apoptosis of porcine granulosa cells by targeting the 3β-hydroxysteroid-Δ24-reductase gene

  • Zhang, Xiaodong;Tao, Qiangqiang;Shang, Jinnan;Xu, Yiliang;Zhang, Liang;Ma, Yingchun;Zhu, Weihua;Yang, Min;Ding, Yueyun;Yin, Zongjun
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.4
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    • pp.547-555
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    • 2020
  • Objective: Apoptosis of ovarian granulosa cells (GCs) affects mammalian follicular development and fecundity. This study aimed to explore the regulatory relationship between microRNA-26a (miR-26a) and the 3β-hydroxysteroid-Δ24-reductase gene (DHCR24) gene in porcine follicular granular cells (pGCs), and to provide empirical data for the development of methods to improve the reproductive capacity of pigs. Methods: The pGCs were transfected with miR-26a mimic, miR-26a inhibitor and DHCR24-siRNA in vitro. The cell apoptosis rate of pGCs was detected by the flow cytometry. The secretion levels of estradiol (E2) and progesterone (P) in pGCs were detected by enzyme-linked immunosorbent assay. Double luciferase validation system was used to detect the binding sites between miR-26a and DHCR24 3'-UTR region. Qualitative real-time polymerase chain reaction and Western blotting were used to verify the DHCR24 mRNA and protein expression in pGCs, respectively, after transfecting with miR-26a mimic and miR-26a inhibitor. Results: Results showed that enhancement of miR-26a promoted apoptosis, and inhibited E2 and P secretion in pGCs. Meanwhile, inhibition of DHCR24 also upregulated the Caspase-3 expression, reduced the BCL-2 expression, promoted pGCs apoptosis, and inhibited E2 and P secretion in pGCs. There were the binding sites of miR-26a located within DHCR24 3'-UTR. Up-regulation of miR-26a inhibited DHCR24 mRNA and protein expression in pGCs. Conclusion: This study demonstrates that miR-26a can promote cell apoptosis and inhibit E2 and P secretion by inhibiting the expression of DHCR24 in pGCs.

Human brain pyridoxal-5'-phosphate phosphatase (PLPP): protein transduction of PEP-1-PLPP into PC12 cells

  • Lee, Yeom-Pyo;Kim, Dae-Won;Lee, Min-Jung;Jeong, Min-Seop;Kim, So-Young;Lee, Sun-Hwa;Jang, Sang-Ho;Park, Jin-Seu;Kang, Tae-Cheon;Won, Moo-Ho;Cho, Sung-Woo;Kwon, Oh-Shin;Eum, Won-Sik;Choi, Soo-Young
    • BMB Reports
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    • v.41 no.5
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    • pp.408-413
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    • 2008
  • Pyridoxal-5'-phosphate phosphatase (PLPP) catalyzes the dephosphorylation of pyridoxal-5'-phosphate (PLP). A human brain PLPP gene was fused with a PEP-1 peptide and produced a genetic in-frame PEP-1-PLPP fusion protein. The purified PEP-1-PLPP fusion protein was efficiently transduced into PC12 cells in a time- and dose-dependent manner when added exogenously to culture media. Once inside the cells, the transduced PEP-1-PLPP fusion protein was stable for 36 h. The concentration of PLP was markedly decreased by the addition of exogenous PEP-1-PLPP to media pretreated with the vitamin $B_6$ precursors; pyridoxine, pyridoxal kinase and pyridoxine-5'-phosphate oxidase into cells. The results suggest that the transduction of the PEP-1-PLPP fusion protein can be one mode of PLP level regulation, and to replenish this enzyme in the various neurological disorders related to vitamin $B_6$.

Synthesis of Alcohol-oxidase in Pichia pastoris on Various Carbon Sources (여러가지 탄소원에 의한 Pichia pastoris의 Alcohol-oxidase 생성)

  • Lee, Myung-Suk;Hur, Sung-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.18 no.4
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    • pp.435-443
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    • 1989
  • The regulation of the synthesis of alcohol-oxidase(E. C. 1. 1. 3. 13) was investigated in the methanol-utilizing yeasts during growth on different carbon sources. For this experiment, Pichia pastoris CBS 2612 and Pichia pastoris CBM 10 were cultured in mineral salt medium by changing its carbon sources. The production of alcohol-oxidase was varied by the carbon sources. For example, alcohol-oxidase was undetectable in all strains submitted to the test in the medium with glucose, but its production was rapidely increased when the carbon source was changed from glucose to methanol after 48hrs of incubation. Moreover, this enzyme was not synthesized during growth on the primary aliphatic alcohols alone(ethanol, propanol, butanol or pentanol) or on the mixed substrates(0.5% methanol+0.5% primary aliphatic alcohols). When cells were grown on the various carbon sources(glucose, xylose, lactose, glycerol, galactose, saccharose, sorbose, lactic acid or acetic acid), The alcohol-oxidase activity was detected a very little amounts. These carbon sources together with methnol yieled far better synthesis of alcohol-oxidase than in case of carbon sources alone. Especially, the alcohol-oxidase activity of the cells grown on sorbose, lactose or lactic acid together with methanol was far better or similar than that of cells grown on methanol alone. The apparent Km values for the methanol of Pichia pastoris CBS 2612 and Pichia pastoris CBM 10 enzymes were 1.92 and 210 mM, respectively. It is also active towards alcohols of shorter alkyl-chain length than $C_7$, insaturated alcohols(allylalcohol, crotyl-alcohol) and secondary alcohols (iso-amylacohol, iso-butylalcohol). The affinity of alcohol-oxidase for this alcohols decreased with the increasing length of the alkyl-chain.

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Studies on Steroid Hormone Concentration during the Estrous Cycle in the MediKinetics Micropig®

  • Seong, Hun-Ki;Seo, Kyeong-Seok;Kim, Jeong-Su;Her, Chang-Gi;Kang, Myung-Hwa;Sim, Bo-Woong;Yoon, Jong-Taek;Min, Kwan-Sik
    • Reproductive and Developmental Biology
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    • v.41 no.1
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    • pp.1-6
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    • 2017
  • In all mammalian species, progesterone is essential to both the preparation for, and maintenance of, pregnancy. The $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) enzyme predominantly converts progesterone into its biologically inactive form $20{\alpha}$-hydroxyprogesterone, thereby regulating its activity. Thus, to directly assess sexual maturation in the MediKinetics $micropig^{(R)}$, we analyzed the concentration of the steroid hormones progesterone and estradiol during the estrous cycle. Our results show that the progesterone level exhibited by the analyzed $micorpig^{(R)}$ was low at the beginning of the estrous cycle, and then abruptly increased to $30.32{\pm}10.0ng/mL$ and $46.37{\pm}11.0ng/mL$ by days 9 and 11 of the cycle, respectively. It reached the highest level $55.87{\pm}3.5ng/mL$ on day 13 of the estrous cycle, before decreasing to $46.58{\pm}13.1ng/mL$ and $10.0{\pm}7.6ng/mL$ by days 15 and 17 of the cycle, respectively. In contrast, the estradiol level was shown to be highest ($27.13{\pm}11.2ng/mL$) at the initiation of the estrous cycle, after which point it decreased to $13.29{\pm}6.5ng/mL$ and $10.94{\pm}5.9ng/mL$ by days 4 and 5 of the estrous cycle, respectively. By day 17 of the estrous cycle, the estradiol level decreased to $4.13{\pm}7.6ng/mL$. We anticipate that these results will provide useful information to enable the study of human ovulation and reproductive physiology using the MediKinetics $micoripig^{(R)}$ as a model system. We recommend further investigation to elucidate the functional mechanisms underlying the regulation of sexual maturation in the MediKinetics $micropig^{(R)}$.

Gene Silencing Induced by Cytosine Methylation in Transgenic Tomato (형질전환 토마토에서 Cytosine Methylation에 의한 유전자발현 억제)

  • Jung, Seo-Hee;Min, Sung-Ran;Lee, Soo-Young;Park, Ji-Young;Davarpanah, S Javad;Chung, Hwa-Jee;Jeon, Jae-Heung;Liu, Jang-Ryol;Jeong, Won-Joong
    • Journal of Plant Biotechnology
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    • v.34 no.4
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    • pp.323-329
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    • 2007
  • Transgene expression was analyzed in tomato plants. Four lines of neomycin phosphotransferase II gene (NPTII) and the trehalose biosynthetic fusion gene (TPSP) transformed $T_0$ plants showed kanamycin resistance on selection medium. However, the analysis of phenotype (kanamycin resistance) and mRNA expression in $T_1$ plants indicated that the expression of the NPTII and TPSP transgenes was down-regulated to an undetectable level in two independent lines 1 and 11. Southern analysis demonstrated that the lines 1 and 11 had multicopies of the transgenes, whereas the typical transgenic lines 2 and 10 had 1 or 2 copies. DNA methylation analysis using methylation sensitive enzyme detected accumulated CpG DNA methylation on TPSP coding region and CaMV35S promoter region in the line 11, but not the typical transgenic line 2. These results suggest that multicopy transgene in plants is attributed to down-regulation of the transgene expression via transcriptional gene silencing.

Protective Effect of Ferments of Hot-water Extract Mixture from Rhodiola sachalinensis and Red Ginseng on Oxidative Stress-induced C2C12 Myoblast (C2C12 근육세포의 산화적 손상에 대한 홍경천-홍삼 추출물 혼합액 발효물의 보호효과)

  • Yoon, Bo-Ra;Kim, Young-Hyun;Lee, Jong-Seok;Hong, Hee-Do;Rhee, Young-Kyoung;Cho, Chang-Won;Kim, Young-Chan;Lee, Ok-Hwan
    • The Korean Journal of Food And Nutrition
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    • v.26 no.3
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    • pp.485-491
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    • 2013
  • Rhodiola spp. and red ginseng have been used for food and medicinal applications in disease chemoprevention in many Asian countries. Increased oxidative stress by reactive oxygen species (ROS) has been proposed to be a major cause of muscle fatigue. The present study was designed to investigate the protective effects of a fermented hot-water extract mixture from Rhodiola sachalinensis and red ginseng (MFR) on cell damage and the antioxidant enzyme system in $H_2O_2$-induced oxidative stress in skeletal muscle cells. C2C12 myoblasts were treated with various concentrations of NFR (non-fermented Rhodiola sachalinensis extract), FR (fermented hot-water extract from Rhodiola sachalinensis) and MFR for up to 5 days after the standard induction of differentiation, followed by semi-quantitative RT-PCR. MFR treatment dose-dependently protected oxidative damage of C2C12 cells. The treatment with MFR also enhanced mRNA expressions of MyoD, Cu/Zn SOD, Mn-SOD and GPX up to 16%. These results indicate that MFR exerts an anti-oxidative effect through a mechanism (s) that may involve the up-regulation of antioxidant enzymes, which may be important for the cellular redox environment in muscle cells.

BIOLOGICALLY-BASED DOSE-RESPONSE MODEL FOR NEUROTOXICITY RISK ASSESSMENT

  • Slikker, William Jr.;Gaylor, David W.
    • Toxicological Research
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    • v.6 no.2
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    • pp.205-213
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    • 1990
  • The regulation of neurotoxicants has usually been based upon setting reference doses by dividing a no observed adverse effect level (NOAEL) by uncertainty factors that theoretically account for interspecies and intraspecies extraploation of experimental results in animals to humans. Recently, we have proposed a four-step alternative procedure which provides quantitative estimates of risk as a function of dose. The first step is to establish a mathematical relationship between a biological effect or biomarker and the dose of chemical administered. The second step is to determine the distribution (variability) of individual measurements of biological effects or their biomarkers about the dose response curve. The third step is to define an adverse or abnormal level of a biological effect or biomarker in an untreated population. The fourth and final step is to combine the information from the first three steps to estimate the risk (proportion of individuals exceeding on adverse or abnormal level of a biological effect or biomarker) as a function of dose. The primary purpose of this report is to enhance the certainty of the first step of this procedure by improving our understanding of the relationship between a biomarker and dose of administered chemical. Several factors which need to be considered include: 1) the pharmacokinetics of the parent chemical, 2) the target tissue concentrations of the parent chemical or its bioactivated proximate toxicant, 3) the uptake kinetics of the parent chemical or metabolite into the target cell(s) and/or membrane interactions, and 4) the interaction of the chemical or metabolite with presumed receptor site(s). Because these theoretical factors each contain a saturable step due to definitive amounts of required enzyme, reuptake or receptor site(s), a nonlinear, saturable dose-response curve would be predicted. In order to exemplify this process, effects of the neurotoxicant, methlenedioxymethamphetamine (MDMA), were reviewed and analyzed. Our results and those of others indicate that: 1) peak concentrations of MDMA and metabolites are ochieved in rat brain by 30 min and are negligible by 24 hr, 2) a metabolite of MDMA is probably responsible for its neurotoxic effects, and 3) pretreatment with monoamine uptake blockers prevents MDMA neurotoxicity. When data generated from rats administerde MDMA were plotted as bilolgical effect (decreases in hippocampal serotonin concentrations) versus dose, a saturation curve best described the observed relationship. These results support the hypothesis that at least one saturable step is involved in MDMA neurotoxicity. We conclude that the mathematical relationship between biological effect and dose of MDMA, the first step of our quantitative neurotoxicity risk assessment procedure, should reflect this biological model information generated from the whole of the dose-response curve.

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Different Regulation of p53 Expression by Cadmium Exposure in Kidney, Liver, Intestine, Vasculature, and Brain Astrocytes

  • Lee, Jin-Yong;Tokumoto, Maki;Hattori, Yuta;Fujiwara, Yasuyuki;Shimada, Akinori;Satoh, Masahiko
    • Toxicological Research
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    • v.32 no.1
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    • pp.73-80
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    • 2016
  • Chronic exposure to cadmium (Cd) is known to adversely affect renal function. Our previous studies indicated that Cd induces p53-dependent apoptosis by inhibiting gene expression of the ubiquitin-conjugating enzyme (Ube) 2d family in both human and rat proximal tubular cells. In this study, the effects of Cd on protein expression of p53 and apoptotic signals in the kidney and liver of mice exposed to Cd for 12 months were examined, as well as the effects of Cd on p53 protein levels and gene expression of the Ube2d family in various cell lines. Results showed that in the kidney of mice exposed to 300 ppm Cd for 12 months, there was overaccumulation of p53 proteins in addition to the induction of apoptosis, which was triggered specifically in the proximal tubules. Interestingly, the site of apoptosis was the same as that of p53 accumulation in the proximal tubules. In the liver of mice chronically exposed to Cd, gene expression of the Ube2d family tended to be slightly decreased, together with slight apoptosis without the accumulation of p53 protein. In rat small intestine epithelial (IEC-6) cells, Cd decreased not only the p53 protein level but also gene expression of Ube2d1, Ube2d2 and Ube2d4. In human brain microvascular endothelial cells (HBMECs), Cd did not suppress gene expression of the Ube2d family, but increased the p53 protein level. In human brain astrocytes (HBASTs), Cd only increased gene expression of UBE2D3. These results suggest that Cd-induced apoptosis through p53 protein is associated with renal toxicity but not hepatic toxicity, and the modification of p53 protein by Cd may vary depending on cell type.