• Title/Summary/Keyword: P-Glycoprotein

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Toxic Components of Auricularia polytricha

  • Kim, Ha-Won
    • Archives of Pharmacal Research
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    • v.16 no.1
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    • pp.36-42
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    • 1993
  • To find biologically active components of the higher fungi of Korea, the carpophores of Auricularia polytricha, a well-known edible mushroom, were extracted with 0.14 M NaCl solution. The extract was successively fractionated by adding ammonium sulfate at various concentrations, and the respective precipitates were separated by centrifugation, then dialyzed and freeze-dried. When a does of 60 mg/kg of each was injected i.p. into ICR mice, the fraction which precipitated at 20% ammonium sulfate showed the highest toxicity, killing seven out of seven mice within two days. The fraction obtained at 40% ammonium sulfate showed the second highest toxicity. The two fractions were named auritoxin I and II after the genus name. However, they Nere shown to have nearly identical composition by physicochemical and 6.8% protein. The polysaccharide moiety was found to have 12.3% $\alpha$-linkage and 87.7% $\beta$-linkage and to be a heteromannoglucan consisting of 45.1% glucose, 435 mannose and 11.0% xylose. The protein moiety contained ten amino adids. The molecular weight of the toxin was $1.5\times10^6$ dalton by Sepharose CL-4B gel filtration. The modian lethal doses of auritoxin in mice were 56.4, 157.2 and 454.6 mg/kg by i.p., s.c. and p.o.administrations, respectively. The signs of intrxication were convulsion during the first 30 minutes after the injection, coma or sleeping within an hour, termor, lacrimation, nasal bleeding congestion, and death in 24 hours. Smong the various organs, the spleen was found to be enlarged remarkably. Human platelet aggregation was inhibited by the addition of auritoxin. The activity of malic dehydrogenase in vitro was inhibited by the toxin.

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Amphiregulin (AREG) Genotypes, Allele Frequencies and the First Parity Litter Size in the Pig

  • Kim, Du-Wan;Nam, Yoon Seok;Park, Hee-Bok;Kim, Jong Gug
    • Journal of Embryo Transfer
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    • v.30 no.2
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    • pp.91-97
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    • 2015
  • Amphiregulin (AREG), a glycoprotein that is a member of the epidermal growth factor (EGF) family, is expressed by the porcine conceptus and endometrium. AREG genotypes were determined based on an SNP in the intron 3 of the gene. Contradictory effects of AREG genotypes on reproductive traits in different pig breeds were reported previously. G allele had undesirable effect on reproductive trait in Meishan breed, while it had favorable effects in Polish Landrace and Large White. We determined AREG genotypes of 179 pigs including the Duroc, Landrace, Yorkshire, Korean native pig (KNP), and Meishan breeds. Two new SNPs were identified near the previously reported SNP in the intron 3 of AREG. Frequencies of AREG alleles among the Duroc, Landrace, Yorkshire, and KNP sows were significantly different (p<0.001), indicating association between AREG genotypes and pig breeds. The first parity litter size was significantly affected by the breeds (p=0.014), but not by AREG genotypes (p=0.148). However, there were breed and AREG genotype associated trends in the first parity litter size. The first parity litter size appeared to be higher in Duroc and KNP sows with G allele, while it appeared to be lower in Landrace sows with G allele. Significant variability of AREG alleles among pig breeds, for the first time in Duroc and KNP sows, was identified. AREG genotypes may influence reproductive traits differentially for each breed and thus, AREG genotypes may need to be considered when sows are bred to increase litter size.

Effects of heat stress on growth performance, selected physiological and immunological parameters, caecal microflora, and meat quality in two broiler strains

  • Awad, Elmutaz Atta;Najaa, Muhamad;Zulaikha, Zainool Abidin;Zulkifli, Idrus;Soleimani, Abdoreza Farjam
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.5
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    • pp.778-787
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    • 2020
  • Objective: This study was conducted to investigate the effects of normal and heat stress environments on growth performance and, selected physiological and immunological parameters, caecal microflora and meat quality in Cobb 500 and Ross 308 broilers. Methods: One-hundred-and-twenty male broiler chicks from each strain (one-day-old) were randomly assigned in groups of 10 to 24 battery cages. Ambient temperature on day (d) 1 was set at 32℃ and gradually reduced to 23℃ on d 21. From d 22 to 35, equal numbers of birds from each strain were exposed to a temperature of either 23℃ throughout (normal) or 34℃ for 6 h (heat stress). Results: From d 1 to 21, strain had no effect (p>0.05) on feed intake (FI), body weight gain (BWG), or the feed conversion ratio (FCR). Except for creatine kinase, no strain×temperature interactions were observed for all the parameters measured. Regardless of strain, heat exposure significantly (p<0.05) reduced FI and BWG (d 22 to 35 and 1 to 35), immunoglobulin Y (IgY) and IgM, while increased FCR (d 22 to 35 and 1 to 35) and serum levels of glucose and acute phase proteins (APPs). Regardless of temperature, the Ross 308 birds had significantly (p<0.05) lower IgA and higher finisher and overall BWG compared to Cobb 500. Conclusion: The present study suggests that the detrimental effects of heat stress are consistent across commercial broiler strains because there were no significant strain×temperature interactions for growth performance, serum APPs and immunoglobulin responses, meat quality, and ceacal microflora population.

Purification and Characterization of ${\beta}-Glucosidase$ from Penicillium verruculosum

  • Chun, Soon-Bai;Kim, Dong-Ho;Kim, Kang-Hwa;Chung, Ki-Chul
    • Journal of Microbiology and Biotechnology
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    • v.1 no.3
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    • pp.188-196
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    • 1991
  • The ${\beta}-glucosidase$ was purified to homogeneity from the culture filtrate of P. verruculosum by column chromatography. The enzyme was a glycoprotein with a relative size of approximately 220 kDa with an isoelectric point of 4.8, which was composed of dimeric protein of 105 kDa. The enzyme was stable up to $60^{\circ}C$ and the presence of glycerol significantly increased its thermostability. The enzyme was found to hydrolyze both ${\beta}-aryl$ and ${\beta}-alkyl-glucosides$ in addition to ${\beta}-glucosyl$ glucose and catalyzed glucosyl transfer to cellobiose. The enzyme attacked laminarin in an exotype-like fashion. The apparent Km's of the enzyme toward cellobiose, laminaribiose, laminarin were 0.53 mM, 0.35 mM and 1.11 mM, respectively. Glucose and glucono-${\delta}-lactone$ were competitive inhibitors for the enzyme. Copper ($Cu^{2+}$), mercury ($Hg^{2+}$) and p-chloromercuribenzoate were strong inhibitors of the enzyme. The immunoblotting result revealed that one form of ${\beta}-glucosidase$ was biosynthesized, irrespective of carbon sources used. Polyacrylamide gel electrophoresis analysis of the in vitro translated product of total RNA from avicel grown mycelium established that the P. verruculosum ${\beta}-glucosidase$ precursor was approximately 95 kDa in size. The amino acid composition and N-terminal amino acid sequence are given.

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Association of Adiponectin Receptor (Adipo-R1/-R2) Expression and Colorectal Cancer

  • Ayyildiz, Talat;Dolar, Enver;Ugras, Nesrin;Adim, Saduman Balaban;Yerci, Omer
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9385-9390
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    • 2014
  • Introduction: Human adiponectin (ApN) is a 30 kDa glycoprotein of 244-amino acids which is extensively produced by adipocytes. ApN acts via two receptors, namely adiponectin receptor-1 (Adipo-R1) and adiponectin receptor-2 (Adipo-R2). Studies have shown the presence of Adipo-R1 and Adipo-R2 expression immunohistochemically in human colorectal cancers (CRCs). However, only a few studies exist which investigated effects of adiponectin receptor expression on CRC characteristics. Objectives: In the present study, we aimed to explore Adipo-R1/-R2 expression in human colorectal cancers and any association with clinicopathological characteristics and survival. Materials and Methods: The study enrolled 58 colorectal cancer patients with tumor resection and a control group of 30 subjects with normal colon mucosa. Results: Positivity for Adipo-R1/-R2 expression was significantly more common in the control group in comparison to the patient group (both p<0.001). There was no significant association between Adipo-R1/-R2 expression and clinicopathological characteristics including age, sex tumor location, pTNM stage, Duke's stage, metastasis, histological differentiation, perineural invasion, venous invasion sex, lymphatic invasion, cancer-related mortality, tumor size and recurrence. Adipo- R1/-R2 positivity was also not significantly linked to progression-free or overall survival [p values (0.871, 0.758) and (0.274, 0.232), respectively]. Conclusions: Although significantly reduced Adipo-R1/-R2 expression was found in colorectal cancer patients, it had no influence on survival.

Clinicopathological Significance of Reduced SPARCL1 Expression in Human Breast Cancer

  • Cao, Fang;Wang, Kuo;Zhu, Rong;Hu, Yong-Wei;Fang, Wen-Zheng;Ding, Hou-Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.195-200
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    • 2013
  • Secreted protein acidic and rich in cysteines-like protein 1 (SPARCL1), an extracellular matrix glycoprotein, has been implicated in the pathogenesis of several disorders including cancer. However, little is known about the expression and significance of SPARCL1 in human breast cancer. The aim of this study was to determine the expression pattern and clinicopathological significance of SPARCL1 in a Chinese breast cancer cohort. mRNA and protein expression of SPARCL1 in human breast cancer cell lines and breast cancer tissues was detected using the reverse transcription-polymerase chain reaction, real-time quantitative PCR, and Western blotting, respectively. Immunostaining of SPARCL1 in 282 Chinese breast cancer samples was examined and associations with clinicopathological parameters were analyzed. Compared to the positive expression in immortalized human breast epithelial cells, SPARCL1 was nearly absent in human breast cancer cell lines. Similarly, a significantly reduced expression of SPARCL1 was observed in human breast cancer tissues compared to that in normal breast epithelial tissues, for both mRNA and protein levels (P < 0.001). Immunohistochemical analysis showed that strong cytoplasmic immunostaining of SPARCL1 was observed in almost all normal breast samples (43/45) while moderate and strong immunostaining of SPARCL1 was only detected in 191 of 282 (67.7%) breast cancer cases. Moreover, down-regulation of SPARCL1 was significantly correlated with lymphatic metastasis (P = 0.020) and poor grade (P = 0.044). In conclusion, SPARCL1 may be involved in the breast tumorigenesis and serve as a promising target for therapy of breast cancer.

Possible Roles of the Xenobiotic Transporter P-glycoproteins Encoded by the MDR1 3435 C>T Gene Polymorphism in Differentiated Thyroid Cancers

  • Ozdemir, Semra;Uludag, Ahmet;Silan, Fatma;Atik, Sinem Yalcintepe;Turgut, Bulent;Ozdemir, Ozturk
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3213-3217
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    • 2013
  • Background: P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter which plays an important role in pharmacokinetics. The current preliminary study was designed to determine associations between a germ-line polymorphism in the MDR1 gene with differentiated thyroid carcinoma (DTC). Materials and Methods: In the current case-control study, 60 differentiated thyroid cancers (DTC)- 45 papillary TC (PTC), 9 follicular TC(FTC) and 6 well-differentiated tumors of uncertain malignant potential (WDT-UMP) were examined. Results were compared to a healthy control group (n=58) from the same population. Genomic DNA was extracted from peripheral blood with EDTA and the target gene was genotyped by real-time PCR. Results: Carriers of the variant allele of MDR1 exon 26 polymorphism were at 2.8-fold higher risk of DTC than the control group (odds ratio [OR]: 0.3805, 95% confidence interval [Cl]: 0.1597-0.9065 (p> 0.046). Conclusions: Presented results suggest that the MDR1 3435TT genotype might influence risk of development of DTC and that the CC genotype might be linked to a poor prognosis. Large-scale studies are now needed to validate this association.

Effects of Diabetes Mellitus on the Disposition of Tofacitinib, a Janus Kinase Inhibitor, in Rats

  • Gwak, Eun Hye;Yoo, Hee Young;Kim, So Hee
    • Biomolecules & Therapeutics
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    • v.28 no.4
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    • pp.361-369
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    • 2020
  • Tofacitinib, a Janus kinase inhibitor, was developed for the treatment of rheumatoid arthritis. Recently, it has been associated with an increased change in arthritis development in patients with diabetes. Herein, we evaluated the pharmacokinetics of tofacitinib after intravenous (10 mg/kg) and oral (20 mg/kg) administration to rats with streptozotocin-induced diabetes mellitus and control rats. Following intravenous administration of tofacitinib to rats with streptozotocin-induced diabetes mellitus, area under the plasma concentration-time curve from time zero to infinity of tofacitinib was significantly smaller (33.6%) than that of control rats. This might be due to the faster hepatic intrinsic clearance (112%) caused by an increase in the hepatic cytochrome P450 (CYP) 3A1(23) and the faster hepatic blood flow rate in rats with streptozotocin-induced diabetes mellitus than in control rats. Following oral administration, area under the plasma concentration-time curve from time zero to infinity of tofacitinib was also significantly smaller (55.5%) in rats with streptozotocin-induced diabetes mellitus than that in control rats. This might be due to decreased absorption caused by the higher expression of P-glycoprotein and the faster intestinal metabolism caused by the higher expression of intestinal CYP3A1(23), which resulted in the decreased bioavailability of tofacitinib (33.0%) in rats with streptozotocin-induced diabetes mellitus. In summary, our findings indicate that diabetes mellitus affects the absorption and metabolism of tofacitinib, causing faster metabolism and decreased intestinal absorption in rats with streptozotocin-induced diabetes mellitus.

Defining the N-Linked Glycosylation Site of Hantaan Virus Envelope Glycoproteins Essential for Cell Fusion

  • Zheng, Feng;Ma, Lixian;Shao, Lihua;Wang, Gang;Chen, Fengzhe;Zhang, Ying;Yang, Song
    • Journal of Microbiology
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    • v.45 no.1
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    • pp.41-47
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    • 2007
  • The Hantaan virus (HTNV) is an enveloped virus that is capable of inducing low pH-dependent cell fusion. We molecularly cloned the viral glycoprotein (GP) and nucleocapsid (NP) cDNA of HTNV and expressed them in Vero E6 cells under the control of a CMV promoter. The viral gene expression was assessed using an indirect immunofluorescence assay and immunoprecipitation. The transfected Vero E6 cells expressing GPs, but not those expressing NP, fused and formed a syncytium following exposure to a low pH. Monoclonal antibodies (MAbs) against envelope GPs inhibited cell fusion, whereas MAbs against NP did not. We also investigated the N-linked glycosylation of HTNV GPs and its role in cell fusion. The envelope GPs of HTNV are modified by N-linked glycosylation at five sites: four sites on G1 (N134, N235, N347, and N399) and one site on G2 (N928). Site-directed mutagenesis was used to construct eight GP gene mutants, including five single N-glycosylation site mutants and three double-site mutants, which were then expressed in Vero E6 cells. The oligosaccharide chain on residue N928 of G2 was found to be crucial for cell fusion after exposure to a low pH. These results suggest that G2 is likely to be the fusion protein of HTNV.

Effect of Korean Red Ginseng extracts on drug-drug interactions

  • Kim, Se-Jin;Choi, Seungmok;Kim, Minsoo;Park, Changmin;Kim, Gyu-Lee;Lee, Si-On;Kang, Wonku;Rhee, Dong-Kwon
    • Journal of Ginseng Research
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    • v.42 no.3
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    • pp.370-378
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    • 2018
  • Background: Ginseng has been the subject of many experimental and clinical studies to uncover the diverse biological activities of its constituent compounds. It is a traditional medicine that has been used for its immunostimulatory, antithrombotic, antioxidative, anti-inflammatory, and anticancer effects. Ginseng may interact with concomitant medications and alter metabolism and/or drug transport, which may alter the known efficacy and safety of a drug; thus, the role of ginseng may be controversial when taken with other medications. Methods: We extensively assessed the effects of Korean Red Ginseng (KRG) in rats on the expression of enzymes responsible for drug metabolism [cytochrome p450 (CYP)] and transporters [multiple drug resistance (MDR) and organic anion transporter (OAT)] in vitro and on the pharmacokinetics of two probe drugs, midazolam and fexofenadine, after a 2-wk repeated administration of KRG at different doses. Results: The results showed that 30 mg/kg KRG significantly increased the expression level of CYP3A11 protein in the liver and 100 mg/kg KRG increased both the mRNA and protein expression of OAT1 in the kidney. Additionally, KRG significantly increased the mRNA and protein expression of OAT1, OAT3, and MDR1 in the liver. Although there were no significant changes in the metabolism of midazolam to its major metabolite, 1'-hydroxymidazolam, KRG significantly decreased the systemic exposure of fexofenadine in a dose-dependent manner. Conclusion: Because KRG is used as a health supplement, there is a risk of KRG overdose; thus, a clinical trial of high doses would be useful. The use of KRG in combination with P-glycoprotein substrate drugs should also be carefully monitored.