• Title/Summary/Keyword: Protein phosphatase 2A

Search Result 525, Processing Time 0.024 seconds

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
    • /
    • v.36 no.11
    • /
    • pp.1693-1699
    • /
    • 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.

Effects of Angiopoietin-2 on the Proliferation and Activity of Ostoeblasts and Osteoclasts (Angiopoietin-2가 조골세포와 파골세포의 성장과 활성에 미치는 영향)

  • Ko, Seon-Yle
    • Journal of Oral Medicine and Pain
    • /
    • v.31 no.1
    • /
    • pp.17-25
    • /
    • 2006
  • The present study was undertaken to determine the possible cellular mechanism of action of angiopoietin-2 in bone metabolism. The effects on the osteoblasts were determined by measuring 1) cell viability, 2) alkaline phosphatase (ALP) activity, 3) gelatinase activity, and 4) nitric oxide production. The effects on the osteoclasts were investigated by measuring 1) tartrate-resistant acid phosphatase (TRAP)(+) multinucleated cells (MNCs) formation, and 2) resorption areas after culturing osteoclast precursors. Angiopoietin-2 treatment showed a significant increase in both the viability and ALP activity of osteoblasts. Angiopoietin-2 increased the activity of gelatinase and nitric oxide production. In addition, angiopoietin-2 decreased the osteoclast generation induced by macrophage-colony stimulating factor (M-CSF) and receptor activator of NF-kB ligand (RANKL), and inhibited osteoclastic activity in (M-CSF)-dependent bone marrow macrophage (MDBM) cell cultures. Taken these results, angiopoietin-2 may be a regulatory protein within the bone marrow microenvironment.

Effects of Liquid Culture of Agaricus blazei Murill on Protein, Mineral Levels and Enzyme Activities in Rats

  • Koh, Jin-Bog;Kim, Jai-Young
    • Biomedical Science Letters
    • /
    • v.10 no.2
    • /
    • pp.171-177
    • /
    • 2004
  • This study was performed to investigate the effects of liquid culture of Agaricus blazei Murill on the weight gains, food efficiency ratios, serum protein and mineral levels, and serum enzyme activities in growing male rats. Sprague-Dawley rats (7 weeks old) were given four different types of diets for a succeeding period of 6 weeks, respectively: a normal diet group, a control diet group (normal diet + 15% lard + 0.5% cholesterol), a 30% or 40% A. blazei diet groups (control diet + 30% or 40% A. blazei in water) according to the levels of A. blazei supplementation. The body weight gains, food efficiency ratios, and the liver of the rats fed control diet, 30% or 40% A. blazei diets were significantly increased compared to rats fed the normal diet, but those of rats fed the 30% and 40% A. blazei diets were similar to those of rats fed the control diet. The concentrations of total protein, albumin, glucose, and hematocrit value in serum of rats fed the control diet, 30% or 40% A. blazei diets were similar to those of rats fed the normal diet. The concentrations of urea and creatinine in serum of rats fed the 30% or 40% A. blazei diets were similar to those of rats fed the control diet. but the urea of rats fed the 30% and 40% A. blazei diets were significantly decreased compared to rats fed the normal diet. The concentrations of Ca, P, Fe and Mg, and $Ca^{++}$, $K^+$, $Na^+$ and $Cl^-$ of rats fed the control diet, 30% or 40% A. blazei diets were similar to those of rats fed the normal diet. There were no differences in the activities of aspartate aminotransferase, alanine aminotransferase, $\gamma$-glutamyltranspeptidase and alkaline phosphatase in the serum among the experimental groups. In conclusion, the rats fed the A. blazei maintained normal protein and mineral levels, and enzyme activities of serum. But the A. blazei feeding could not decrease the body and liver weights in the rats fed high cholesterol diets.

  • PDF

Gene Cloning and Nucleotide Sequence of Human Dihydrolipoamide Dehydrogenase-Binding Protein

  • Lee, Jeongmin;Ryou, Chongsuk;Jeon, Bong Kyun;Lee, Poongyeon;Woo, Hee-Jong;Kwon, Moosik
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.15 no.3
    • /
    • pp.421-426
    • /
    • 2002
  • The pyruvate dehydrogenase complex (PDC), a member of $\alpha$-keto acid dehydrogenase complex, catalyzes the oxidative decarboxylation of pyruvate with the formation of $CO_2$, acetyl-CoA, NADH, and $H^+$. This complex contains multiple copies of three catalytic components including pyruvate dehydrogenase (E1), dihydrolipoamide acetyltransferase (E2), and dihydrolipoamide dehydrogenase (E3). Two regulatory components (E1-kinase and phospho-E1 phosphatase) and functionally less-understood protein (protein X, E3BP) are also involved in the formation of the complex. In this study, we have partially cloned the gene for E3BP in human. Nine putative clones were isolated by human genomic library screening with 1.35 kb fragment of E3BP cDNA as a probe. For investigation of cloned genes, Southern blot analysis and the construction of the restriction map were performed. One of the isolated clones, E3BP741, has a 3 kb-SacI fragment, which contains 200 bp region matched with E3BP cDNA sequences. The matched DNA sequence encodes the carboxyl-terminal portion of lipoyl-bearing domain and hinge region of human E3BP. Differences between yeast E3BP and mammalian E3BP coupled with the remarkable similarity between mammalian E2 and mammalian E3BP were confirmed from the comparison of the nucleotide sequence and the deduced amino acid sequence in the cloned E3BP. Cloning of human E3BP gene and analysis of the gene structure will facilitate the understanding of the role(s) of E3BP in mammalian PDC.

Hematological and Serum Biochemical Analyses in Experimental Caprine Besnoitiosis

  • Nazifi, Saeed;Oryan, Ahmad;Namazi, Fatemeh
    • Parasites, Hosts and Diseases
    • /
    • v.49 no.2
    • /
    • pp.133-138
    • /
    • 2011
  • This study was undertaken to investigate the hematological and biochemical changes in experimentally infected goats with Besnoitia caprae from the time of infection till 360 days post-infection (PI). Six male goats were inoculated subcutaneously with $13{\times}10^7$ bradyzoites of B. caprae, and blood samples were collected from the jugular vein. The total erythrocyte and total leukocyte counts, hematocrit value, and differential leukocyte counts were determined. Serum biochemical analysis, including the total protein, albumin, total globulin, cholesterol, triglyceride, chloride, testosterone, calcium ($Ca^{2+}$), inorganic phosphorus, sodium ($Na^+$), potassium ($K^+$), iron ($Fe^{2+}$), glucose, serum amyloid A (SAA), haptoglobin (Hp), fibrinogen, ceruloplasmin, aspartate aminotransferase, alanine aminotransferase, creatine kinase, lactate dehydrogenase, and alkaline phosphatase, was undertaken. Skin biopsy from the limbs were collected at weekly intervals and histologically examined for Besnoitia cysts. Cysts were present in the skin biopsies of the leg of the infected goats from day 28 PI. There were variations in hematological analyses, but no significant difference was seen. From day 30 to 360 PI, results showed that SAA, Hp, fibrinogen, and ceruloplasmin concentrations increased, whereas testosterone concentrations decreased. Infected goats exhibited decrease of albumin and increase of serum total protein and globulin concentrations. By contrast, there were no significant differences in the remained analyses concentrations.

8-60hIPP5m-Induced G2/M Cell Cycle Arrest Involves Activation of ATM/p53/p21cip1/waf1 Pathways and Delayed Cyclin B1 Nuclear Translocation

  • Zeng, Qi-Yan;Zeng, Lin-Jie;Huang, Yu;Huang, Yong-Qi;Zhu, Qi-Fang;Liao, Zhi-Hong
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.9
    • /
    • pp.4101-4107
    • /
    • 2014
  • Protein phosphatase 1 (PP1) is a major serine/threonine phosphatase that controls gene expression and cell cycle progression. The active mutant IPP5 ($8-60hIPP5^m$), the latest member of the inhibitory molecules for PP1, has been shown to inhibit the growth of human cervix carcinoma cells (HeLa). In order to elucidate the underlying mechanisms, the present study assessed overexpression of $8-60hIPP5^m$ in HeLa cells. Flow cytometric and biochemical analyses showed that overexpression of $8-60hIPP5^m$ induced G2/M-phase arrest, which was accompanied by the upregulation of cyclin B1 and phosphorylation of G2/M-phase proteins ATM, p53, $p21^{cip1/waf1}$ and Cdc2, suggesting that $8-60hIPP5^m$ induces G2/M arrest through activation of the ATM/p53/$p21^{cip1/waf1}$/Cdc2/cyclin B1 pathways. We further showed that overexpression of $8-60hIPP5^m$ led to delayed nuclear translocation of cyclin B1. $8-60hIPP5^m$ also could translocate to the nucleus in G2/M phase and interact with $pp1{\alpha}$ and Cdc2 as demonstrated by co-precipitation assay. Taken together, our data demonstrate a novel role for $8-60hIPP5^m$ in regulation of cell cycle in HeLa cells, possibly contributing to the development of new therapeutic strategies for cervix carcinoma.

Fermented sea tangle (Laminaria japonica Aresch) Accelerates Osteoblast Differentiation in murine osteoblastic MC3T3-E1 Cells (MC3T3-E1 골아세포에서 발효 다시마 추출물에 의한 조골세포 분화의 촉진)

  • Nara Jeong;Yung Hyun Choi
    • Journal of Marine Bioscience and Biotechnology
    • /
    • v.15 no.1
    • /
    • pp.24-32
    • /
    • 2023
  • The Laminaria japonica Aresch (Sea tangle) belongs to the brown algae and has a long history as a food material in Asia, including Korea. Recent studies have found that the fermented Sea tangle extract (FST) inhibited the differentiation of osteoclasts and protected osteoblasts from oxidative damage. This study aims to explore the possibility that FST can induce the differentiation of osteoblasts and identify the responsible mechanism. According to our results, FST induced differentiation into osteogenic cells in the presence of osteoblastic MC3T3-E1 cells under non-toxic conditions.. This finding was confirmed by phalloidin staining, increased alkaline phosphatase activity, and calcium deposition. Additionally, it was found that this process was achieved by increasing the expression of key factors involved in osteoblast differentiation, such as runt-related transcription factor-2, osterix, β-catenin, and bone morphogenetic protein-2. Moreover, FST increased autophagy, which may contribute to the maintenance of the bone formation homeostasis, and is associated with the activation of the phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase signaling pathways. Although further research about the bioactive substances contained in FST and the tests of their efficacy are required, the results of this study indicate that FST has incredible applicability as a functional material for maintaining the bone homeostasis.

Phosphorylation of AQP4 Water Channel Regulates Water Permeability (Aquaporin 4 water channel 인산화에 의한 수분 투과도의 조절)

  • 박권희;정동근;정진섭;이재숙;예운해;서덕준;배혜란
    • Journal of Life Science
    • /
    • v.10 no.5
    • /
    • pp.456-466
    • /
    • 2000
  • Aquaperin 4 (AQP4) is the mercurial water channel expressed abundantly in brain, especially the region related with cerebrospinal fluid reabsorption and osmoregulation. The primary structure of AQP4 water channel was elucidated but the molecular mechanism of AQP4 channel regulation is still unknown. To investigate the possible regulation of AQP4 water channel by phosphorylation via various protein kinases, osmotic water permeability of AQP4 expressed in Xenopus oocytes was measured by videomicroscopy technique. Forskolin (10 $\mu$M) did not affect osmotic water permeability of oocytes injected with AQP4 cRNA, excluding the regulation of AQP4 water cnannel by protein kinase A. Osmotic water permeability (P아래첨자) of AQP4-expressed oocytes was ingibited by the pretreatmeat of BAPTA/AM (up to 500$\mu$M), an intracellular Ca윗첨자 chelator, and calmidazolium (100$\mu$M), a specific Ca윗첨자/calmodulin antagonist, in a dose-dependent manner. The inhibition of osmotic water permeability (P아래첨자) by the calmidazolium treatment was completely reversed by the addition of calyculin A (0.1$\mu$M), a nonspecific phosphatase inhibitor. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, had biphasic effects on osmotic water permeability in AQP4 cRNA injected oocytes depending on its concentration; 21% increase by 100 nM PMA, 35% decrease by 1$\mu$M PMA. These effects were reversed with 2$\mu$M staurosporine, a nonspecific PKC inhibitor. These results suggest that phosphorylation of AQP4 water channel by Ca윗첨자/calmodulin kinase and protein kinase C might regulate the osmotic water permeability.

  • PDF

Osteoblastogenesis and osteolysis in the Zucker Diabetic Sprague Dawley rat humerus head

  • Gcwalisile Frances Dlamini;Robert Ndou
    • Anatomy and Cell Biology
    • /
    • v.56 no.4
    • /
    • pp.552-561
    • /
    • 2023
  • The endocrinology of type 2 diabetes (T2D) and its predisposing factors have been studied extensively while its skeletal effects have received negligible research despite this being a global disease. The cellular and molecular association between proximal humeral fractures and T2D has not been fully elucidated. We aimed to study bone cell quantities and immunolabel osteogenic and antiosteogenic cytokines. The study used 12-week-old rats (23 males) consisting of 8 Sprague Dawley (SD) and 15 Zucker Diabetic Sprague Dawley (ZDSD). Weekly mass measurements were taken while fasting blood glucose levels were recorded every 2 weeks with oral glucose tolerance tests conducted once every 4 weeks. Upon termination at the age of 28 weeks, humeri were fixed in 10% buffered formalin, prior to decalcification in ethylenediaminetetraacetic acid. The bone samples were then processed in ascending grades of alcohol using an automatic processor before embedding in paraffin wax. Sections were cut at 5 ㎛ thickness in a series for Haematoxylin and Eosin stain, and immunohistochemistry was performed with the anti-tartrate-resistant acid phosphatase (TRAP), anti-alkaline phosphatase (ALP), anti-bone morphogenetic protein 3 (BMP3), anti-transforming growth factor beta 1 (TGFβ1), anti-aged glycation end product (AGE) antibodies in the sequence. ZDSD rats had more adipocytes, BMP3 and AGEs expression with higher numbers of TRAP positive osteocytes and fewer ALP cells although no differences were found in TGFβ1 immunopositivity. We also found that T2D increases the number of AGEs immuno-positive cells, as well as its extracellular expression, thus providing a conducive environment for the interaction of the osteogenic cytokine and its antagonist to suppress osteoblastogenesis. ZDSD groups had higher adipocyte numbers therefore increased marrow adiposity in T2D.

Studies on the Nutrition under Abnormal Environment(I) -Nutrition under Vibration- (이상환경하(異常環境下)의 영양문제(營養問題) 연구(硏究)(제1보) -진동하(振動下)의 영양문제(營養問題)-)

  • Yu, Jong-Yull
    • Journal of Nutrition and Health
    • /
    • v.4 no.4
    • /
    • pp.15-23
    • /
    • 1971
  • On the assumption that the supplementation of certain nutrients or foods to the rice diet (low protein, low fat, and low vitamins) may decrease, to some extent, the degree of suffering from abnormal environments, such as vibration, noises, gases, dusts, smog etc. a series of experiments were started. As the first report the nutrition under vibration was studied in this experiment. Sixty (60) young growing male rats weighing about 65 grams were used, grouping to five (5) groups, twelve (12) rats each group. They were fed on the following five (5) experimental diets: rice diet (basal diet), rice diet+casein, rice diet+vitamins, rice $diet+{\alpha}-tocopherol$, and rice diet+ginseng powder (see the tables 1 and 2) for the period of 14 weeks experiment. During the experiment period the half number of the rats of each group were exposed to the three (3) hours vibration every day. The protective effect of each diet against the vibration may be summarized as follows. 1. The growth of rice diet group was impaired significantly under vibration, However, those of other groups (protein-supplemented, vitamin-supplemented, ${\alpha}-tocopherol-supplemented$ and ginseng-supplemented groups) were impaired much less compared with rice diet group. 2. The feed efficiency of the rice diet group was decreased significantly under vibration. It is estimated that the biological availability of nutrients was impaired under this environment. On the other hand, the feed efficiencies of protein supplemented, of vitamin supplemented, and of ginseng supplemented groups were not decreased under vibration, statistically. 3. There is tendency that the food spillages of vibration groups are higher than those of non-vibration groups. Especially it seems true in the case of rice diet group. The food spillage may be, to some extent, related with mental nervousness of animals. From the point that the food spillage of ginseng supplemented group is significantly lower than those of other groups it is thought ginseng acts some good role in protecting nervous system from suffering from vibration. 4. In all groups except protein supplemented group, liver fat of vibration group tends to be higher than that of non-vibration group. 5. It shows that, in general, the serum alkaline phosphatase activity of the vibration group is significantly higher than that of the non-vibration group. It seems that there may be, to some extent, corelation between the amount of liver fat and serum alkaline phosphatase activity. 6. There is tendency that, in rice diet group, the organs of vibration group are smaller than those of non-vibration group, especially lung is so. It is thought that this may be due to the poor growth of whole body size in vibration group.

  • PDF