• Title/Summary/Keyword: Protein expressions

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The molecular mechanism of propionate-regulating gluconeogenesis in bovine hepatocytes

  • Rui Pang;Xiao Xiao;Tiantian Mao;Jiajia Yu;Li Huang;Wei Xu;Yu Li;Wen Zhu
    • Animal Bioscience
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    • v.36 no.11
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    • pp.1693-1699
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    • 2023
  • Objective: Cows that are nursing get around 80% of their glucose from liver gluconeogenesis. Propionate, a significant precursor of liver gluconeogenesis, can regulate the key genes involved in hepatic gluconeogenesis expression, but its precise effects on the activity of enzymes have not yet been fully elucidated. Therefore, the aim of this study was to investigate the effects of propionate on the activity, gene expression, and protein abundance of the key enzymes involved in the gluconeogenesis of dairy cow hepatocytes. Methods: The hepatocytes were cultured and treated with various concentrations of sodium propionate (0, 1.25, 2.50, 3.75, and 5.00 mM) for 12 h. Glucose content in the culture media was determined by an enzymatic coloring method. The activities of gluconeogenesis related enzymes were determined by enzyme linked immunosorbent assay kits, and the levels of gene expression and protein abundance of the enzymes were detected by real-time quantitative polymerase chain reaction and Western blot, respectively. Results: Propionate supplementation considerably increased the amount of glucose in the culture medium compared to the control (p<0.05); while there was no discernible difference among the various treatment concentrations (p>0.05). The activities of cytoplasmic phosphoenolpyruvate carboxylase (PEPCK1), mitochondrial phosphoenolpyruvate carboxylase (PEPCK2), pyruvate carboxylase (PC), and glucose-6-phosphatase (G6PC) were increased with the addition of 2.50 and 3.75 mM propionate; the gene expressions and protein abundances of PEPCK1, PEPCK2, PC, and G6PC were increased by 3.75 mM propionate addition. Conclusion: Propionate encouraged glucose synthesis in bovine hepatocytes, and 3.75 mM propionate directly increased the activities, gene expressions and protein abundances of PC, PEPCK1, PEPCK2, and G6PC in bovine hepatocytes, providing a theoretical basis of propionate-regulating gluconeogenesis in bovine hepatocytes.

Proteomics-driven Identification of Putative AfsR2-target Proteins Stimulating Antibiotic Biosynthesis in Streptomyces lividans

  • Kim Chang-Young;Park Hyun-Joo;Kim Eung-Soo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.3
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    • pp.248-253
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    • 2005
  • AfsR2, originally identified from Streptomyces lividans, is a global regulatory protein which stimulates antibiotic biosynthesis. Through its stable chromosomal integration, the high level of gene expression of afsR2 significantly induced antibiotic production as well as the sporulation of S. lividans, implying the presence of yet-uncharacterized AfsR2-target proteins. To identify and evaluate the putative AfsR2-target proteins involved in antibiotic regulation, the proteomics-driven approach was applied to the wild-type S. lividans and the afsR2-integrated actinorhodin overproducing strain. The 20 gel-electrophoresis gave approximately 340 protein spots showing different protein expression patterns between these two S. lividans strains. Further MALDI-TOF analysis revealed several AfsR2-target proteins, including glyceraldehyde-3-phosphate dehydrogenase, putative phosphate transport system regulator, guanosine penta phosphate synthetase/polyribonucleotide nucleotidyltransferase, and superoxide dismutase, which suggests that the AfsR2 should be a pleiotropic regulatory protein which controls differential expressions of various kinds of genes in Streptomyces species.

The Effects of Astragali Radix Extracts on Mitochondrial Function in C2C12 Myotubes (C2C12 골격근세포에서 황기의 미토콘드리아 조절 작용)

  • Song, Miyoung
    • Journal of Korean Medicine for Obesity Research
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    • v.14 no.2
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    • pp.55-62
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    • 2014
  • Objective: The prevalence of metabolic syndrome and type 2 diabetes is increasing worldwide. Mitochondrial dysfunction is known to be involved in insulin resistance and obesity, researches have been increasing highly. Astragali Radix extract (ARE) or its main components have been shown to perform comparably to insulin by significantly reducing blood glucose levels in animal models however, the influence on mitochondrial dysfunction are not well understood. Methods: ARE (0.2, 0.5 and 1.0 mg/ml) or metformin (2.5 mM) were treated in C2C12 after 6 day-differentiation. The expressions of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and phosphorylation AMPK, peroxisome proliferators-activated receptror ${\gamma}$ coactivator $1{\alpha}$ ($PGC1{\alpha}$), nuclear respiratory factors 1 (NRF1), mitochondrial transcription factor (Tfam) and myosin heavy chain were detected with western blotting or polymerase chain reaction analysis. The morphological changes were also investigated. Results: ARE dose dependently increased phosphorylation of AMPK and respectively activated mRNA expressions of $PGC1{\alpha}$, NRF1 and Tfam which are mitochondrial biogenesis regulators. Furthermore, there were some morphologic differences of differentiated cells between ARE treatment and control. Conclusions: This study suggests that ARE has the potential to increase muscle mitochondrial function by activating AMPK and $PGC1{\alpha}$.

Modulation of L-Arginine-Arginase Metabolic Pathway Enzymes: Immunocytochemistry and mRNA Expression in Peripheral Blood and Tissue Levels in Head and Neck Squamous Cell Carcinomas in North East India

  • Srivastava, Shilpee;Ghosh, Sankar Kumar
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.16
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    • pp.7031-7038
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    • 2015
  • Background: Arginine may play important roles in tumor progression by providing ornithine for polyamine biosynthesis, required for cell growth. The aim of this work was to determine the expression of arginine metabolic pathway enzymes in head and neck squamous cell carcinoma (HNSCC) in northeast India. Materials and Methods: The expressions of arginase isoforms (ARG1 and ARG2), ornithine aminotransferase (OAT) and ornithine decarboxylase (ODC) were examined in fifty paired HNSCC and adjacent non-tumor tissues by immunohistochemistry. Immunocytochemistry, semiquantitative reverse transcription sq-PCR and quantitative real-time qPCR were used to assess protein and mRNA expressions in peripheral blood of fifty HNSCC patients and hundred controls. Results: ARG1 and ODC protein and mRNA were strongly expressed in peripheral blood from HNSCC patients. No ARG2 expression was observed. In vivo, expression of ARG1, ARG2 and ODC was significantly higher in tumor than in non-tumor tissues. Most tumors expressed low levels of OAT, with no difference in tissues or blood, compared to controls. The absolute extent of maximal ARG1 upregulation with qPCR showed 6.23 fold increase in HNSCC. Conclusions: These findings strongly suggest that in HNSCCs, the ARG1 pathway is stimulated leading to the formation of polyamines as indicated by higher ODC expression, which promote tumor growth.

Effects of Citrus Reticulata on the Cell Detachment and Apoptosis in Human Gastric Cancer SNU-668 Cells

  • Kim, Jeung-Beum;Kim, Min-Su;Kim, Ee-Hwa;Kim, Sung-Hoon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.1
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    • pp.212-217
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    • 2005
  • The purpose of this study was to examine the effects of Citrus Reticulata(CR) on the Cell Detachment and Apoptosis in Human Gastric Cancer SNU-668 Cells. The effect of CR on apoptosis was investigated through MTT assay, DAPI staining, and TUNEL assay. We also performed RT-PCR for apoptotic genes including BCL-2, BAX, and caspase-3, the caspase-3 activity assay, and western blotting for pro-CASP-3. Then, to detect that adhesion of cell to ECM was reduced by CR, we investigated mRNA expression of CDH1 and PTK2 using RT-PCR, and their protein expressions using western blotting, and immunocytochemistry in SNU-668 cells. In this study, the results showed that treatment of CR induced time and dose-dependent cell death in SNU-668 cells. Downregulated mRNA expression of BCL-2, and upregulated mRNA expressions of BAX and CASP-3 indicated that the cell death was due to apoptosis. Protein expression of inactivated CASP-3, and caspase-3 activity assay also showed that apoptosis was induced in CR-treated cells.

Rehmannia Radix(RR) Extracts Inhibit IGF-II Induced VEGF and HIF-1 ${\alpha}$ Expressions in HaCaT Keratinocyte Cells (Rehmannia Radix의 IGF-II로 유도된 HIF-1 ${\alpha}$와 VEGF 발현 억제)

  • Park, Ung;Shin, Yong-Cheol;Ko, Seong-Gyu
    • Journal of Society of Preventive Korean Medicine
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    • v.10 no.2
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    • pp.51-62
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    • 2006
  • Psoriasis is a chronic skin disease characterized by angiogenesis. It has been reported that growth factor as vascular endothelial growth factor(VEGF) and insulin like growth factor(IGF) II are overexpressed in psoriatic epidermis. To investigate the inhibitory effects of IGF-II induced VEGF and HIF-1${\alpha}$ expression by RR extracts, we performed MTS assay, western blots using HaCaT cells. RR extracts significantly reduced IGF-II induced HIF 1${\alpha}$ protein level via MAPK pathway in HaCaT cells. Also, RR extracts inhibited IGF-II induced VEGF mRNA and protein expression levels in the HaCaT keratinocytes. These results suggest that inhibition of HIF-1${\alpha}$ and VEGF expressions by RR extracts contributes to the anti angiogenic effects.

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Olfactory receptors in non-chemosensory tissues

  • Kang, NaNa;Koo, JaeHyung
    • BMB Reports
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    • v.45 no.11
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    • pp.612-622
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    • 2012
  • Olfactory receptors (ORs) detect volatile chemicals that lead to the initial perception of smell in the brain. The olfactory receptor (OR) is the first protein that recognizes odorants in the olfactory signal pathway and it is present in over 1,000 genes in mice. It is also the largest member of the G protein-coupled receptors (GPCRs). Most ORs are extensively expressed in the nasal olfactory epithelium where they perform the appropriate physiological functions that fit their location. However, recent whole-genome sequencing shows that ORs have been found outside of the olfactory system, suggesting that ORs may play an important role in the ectopic expression of non-chemosensory tissues. The ectopic expressions of ORs and their physiological functions have attracted more attention recently since MOR23 and testicular hOR17-4 have been found to be involved in skeletal muscle development, regeneration, and human sperm chemotaxis, respectively. When identifying additional expression profiles and functions of ORs in non-olfactory tissues, there are limitations posed by the small number of antibodies available for similar OR genes. This review presents the results of a research series that identifies ectopic expressions and functions of ORs in non-chemosensory tissues to provide insight into future research directions.

Attenuation of insulin resistance using steamed Polygonatum odoratum var pluriflorum extract in rat skeletal muscle cells L6 myoblast (렛 근육세포 L6에서 둥굴레 추출물의 인슐린저항성 개선)

  • Choi, Mi-Ae
    • The Korea Journal of Herbology
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    • v.31 no.1
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    • pp.1-5
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    • 2016
  • Objectives : The purpose of this study was to investigate inhibitory effects of steamed Polygonatum odoratum extract (POE) on insulin resistance in rat skeletal muscle cells, L6 cells.Methods : Polygonatum odoratum (P. odoratum) extract was extracted with ethyl acetate. Activity of α-glucosidase in POE was measured for blood glucose regulation. MTT assay was examined for cell toxicity. Western blot analysis for measurement of adiponectine, peroxisome proliferator-activated receptorγ (PPARγ), insulin receptor substrate (IRS), glucose transporter 4 (Glut-4) and phosphorylation of serine/threonine-specific protein kinase (Akt) expressions were performed. Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor.Results : The results revealed that POE inhibited α-glucosidase activity. Treatment of POE in L6 cells inhibited the differentiation of L6 cells compared to those of vehicl control. Additionally, protein expressions of adiponectine, PPARγ, IRS and Glut-4 were significantly regulated compared to those of vehicle control (p < 0.05), respectively. Futhermore, phosphorylation of Akt was increased in L6 cells treated with POE compared to that of vehicle control (p < 0.05). pAkt expression was significantly accentuated with Akt inhibitor (LY294002).Conclusions : These results suggest that POE may have potential as a natural agent for prevention/improvement of diabetes, especially, regulation of blood glucose. Therefore, further additional study should be conducted to elucidate in depth the pharmaceutical efficacy of these.

Matrix Metalloproteinase Inhibitors Attenuate Neuroinflammation Following Focal Cerebral Ischemia in Mice

  • Park, Cheol-Hong;Shin, Tae-Kyeong;Lee, Ho-Youn;Kim, So-Jung;Lee, Won-Suk
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.2
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    • pp.115-122
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    • 2011
  • The aim of this study was to investigate whether matrix metalloproteinase (MMP) inhibitors attenuate neuroinflammation in an ischemic brain following photothrombotic cortical ischemia in mice. Male C57BL/6 mice were anesthetized, and Rose Bengal was systemically administered. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold white light. MMP inhibitors, such as doxycycline, minocycline, and batimastat, significantly reduced the cerebral infarct size, and the expressions of monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and indoleamine 2,3-dioxygenase (IDO). However, they had no effect on the expressions of heme oxygenase-1 and neuroglobin in the ischemic cortex. These results suggest that MMP inhibitors attenuate ischemic brain injury by decreasing the expression levels of MCP-1, TNF-${\alpha}$, and IDO, thereby providing a therapeutic benefit against cerebral ischemia.

Delphinidin inhibits cell proliferation and induces apoptosis in MDA-MB-231 human breast cancer cell lines (Delphinidin이 인체 유방암세포 MDA-MB-231의세포증식 억제와 세포사멸 유도에 미치는 영향)

  • Seo, Eun Young
    • Journal of Nutrition and Health
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    • v.46 no.6
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    • pp.503-510
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    • 2013
  • Breast cancer is the most common malignancy in women, both in the developed and developing countries. Anthocyanins are natural coloring of a multitude of foods, such as berries, grapes or cherries. Glycosides of the aglycons delphinidin represent the most abundant anthocyanins in fruits. Delphinidin has recently been reported to inhibit the growth of human tumor cell line. Also, delphinidin is a powerful antioxidant that reportedly exerts beneficial effects in patients with advanced cancer by reducing the level of reactive oxygen species and increasing glutathion peroxidase activity. This study investigates the effects of delphinidin on protein ErbB2, ErbB3 and Akt expressions associated with cell proliferation and Bcl-2, Bax protein associated with cell apoptosis in MDA-MB-231 human breast cancer cell line. MDA-MB-231 cells were cultured with various concentrations (0, 5, 10, and $20{\mu}mol/L$) of delphinidin. Delphinidin inhibited breast cancer cell growth in a dose dependent manner (p < 0.05). ErbB2 and ErbB3 expressions were markdly lower $5{\mu}mol/L$ delphinidin (p < 0.05). In addition, total Akt and phosphorylated Akt levels were decreased dose-dependently in cells treated with delphinidin (p < 0.05). Futher, Bcl-2 levels were dose-dependently decreased and Bax expression was significantly increased in cells treated with delphinidin (p < 0.05). In conclusion, I have shown that delphinidin inhibits cell growth, proliferation and induces apoptosis in MDA-MB-231 human breast cancer cell lines.