The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform

Josef Seifert - One of the best experts on this subject based on the ideXlab platform.

  • Changes in mouse liver and chicken embryo yolk sac membrane soluble proteins due to an organophosphorous insecticide (OPI) diazinon linked to several noncholinergic OPI effects in mice and chicken embryos.
    Pesticide Biochemistry and Physiology, 2014
    Co-Authors: Josef Seifert
    Abstract:

    Abstract The objective of this study was to identify proteins in mouse livers and chicken embryo yolk sac membranes whose quantities were altered by an organophosphorous insecticide ( OPI) treatment and which might be linked, based on their functionality, to the recognized noncholinergic effects of OPI. Mice and fertile chicken eggs were treated with an OPI representative diazinon. The quantitative changes in mouse liver and chicken embryo yolk sac membrane soluble proteins caused by diazinon were determined by two-dimensional electrophoresis. Proteins whose quantity was affected by diazinon were identified by the mass spectrometry. In mouse livers, the altered levels of several enzymes of glucose metabolism were considered with regards to amelioration of hyperglycemia due to diazinon; the reduced levels of 3-hydroxyanthranilate 3,4-Dioxygenase to the changes in the l -tryptophan to NAD metabolism caused by pyrimidinyl and crotonamide OPI; the reduced levels of catalase, peroxiredoxin and superoxide dismutase to OPI-increased lipid and/or kynurenine oxidation, the latter effect resulting also in increased urinary excretion of xanthurenic and kynurenic acids; and an increase in glutathione S-methyltransferase to OPI detoxification. In chicken embryo yolk sac membranes, the reduced availability of Procollagen-Proline Dioxygenase may be the factor in micromelia caused by OPI in chicken embryos.

Kari I. Kivirikko - One of the best experts on this subject based on the ideXlab platform.

  • The Novel Type II Prolyl 4-Hydroxylase Is the Main Enzyme Form in Chondrocytes and Capillary Endothelial Cells, whereas the Type I Enzyme Predominates in Most Cells
    Journal of Biological Chemistry, 1998
    Co-Authors: Pia Annunen, Helena Autio-harmainen, Kari I. Kivirikko
    Abstract:

    Abstract Procollagen-Proline Dioxygenase (EC 1.14.11.2), an α2β2 tetramer in vertebrates, plays a central role in the synthesis of all collagens. Recently an isoform of the α subunit, the α(II) subunit, was characterized in man and mouse and found to form a tetramer with the same β subunit as the previously known α(I) subunit. We report here that the (α(I))2β2 type I tetramer is the main enzyme form in most cell types and tissues and that its contribution to total prolyl 4-hydroxylase activity in cultured cells increases in confluence. Surprisingly, however, the (α(II))2β2 type II enzyme was found to represent at least about 70% of the total prolyl 4-hydroxylase activity in cultured mouse chondrocytes and about 80% in mouse cartilage, the corresponding percentage in mouse bone being about 45% and that in many other mouse tissues about 10% or less. Immunofluorescence studies on samples from a fetal human foot confirmed these data and additionally indicated that the type II enzyme represents the main or only enzyme form in capillary endothelial cells. Thus the type II prolyl 4-hydroxylase is likely to play a major role in the development of cartilages and cartilaginous bones and also of capillaries.

Pia Annunen - One of the best experts on this subject based on the ideXlab platform.

  • The Novel Type II Prolyl 4-Hydroxylase Is the Main Enzyme Form in Chondrocytes and Capillary Endothelial Cells, whereas the Type I Enzyme Predominates in Most Cells
    Journal of Biological Chemistry, 1998
    Co-Authors: Pia Annunen, Helena Autio-harmainen, Kari I. Kivirikko
    Abstract:

    Abstract Procollagen-Proline Dioxygenase (EC 1.14.11.2), an α2β2 tetramer in vertebrates, plays a central role in the synthesis of all collagens. Recently an isoform of the α subunit, the α(II) subunit, was characterized in man and mouse and found to form a tetramer with the same β subunit as the previously known α(I) subunit. We report here that the (α(I))2β2 type I tetramer is the main enzyme form in most cell types and tissues and that its contribution to total prolyl 4-hydroxylase activity in cultured cells increases in confluence. Surprisingly, however, the (α(II))2β2 type II enzyme was found to represent at least about 70% of the total prolyl 4-hydroxylase activity in cultured mouse chondrocytes and about 80% in mouse cartilage, the corresponding percentage in mouse bone being about 45% and that in many other mouse tissues about 10% or less. Immunofluorescence studies on samples from a fetal human foot confirmed these data and additionally indicated that the type II enzyme represents the main or only enzyme form in capillary endothelial cells. Thus the type II prolyl 4-hydroxylase is likely to play a major role in the development of cartilages and cartilaginous bones and also of capillaries.

Helena Autio-harmainen - One of the best experts on this subject based on the ideXlab platform.

  • The Novel Type II Prolyl 4-Hydroxylase Is the Main Enzyme Form in Chondrocytes and Capillary Endothelial Cells, whereas the Type I Enzyme Predominates in Most Cells
    Journal of Biological Chemistry, 1998
    Co-Authors: Pia Annunen, Helena Autio-harmainen, Kari I. Kivirikko
    Abstract:

    Abstract Procollagen-Proline Dioxygenase (EC 1.14.11.2), an α2β2 tetramer in vertebrates, plays a central role in the synthesis of all collagens. Recently an isoform of the α subunit, the α(II) subunit, was characterized in man and mouse and found to form a tetramer with the same β subunit as the previously known α(I) subunit. We report here that the (α(I))2β2 type I tetramer is the main enzyme form in most cell types and tissues and that its contribution to total prolyl 4-hydroxylase activity in cultured cells increases in confluence. Surprisingly, however, the (α(II))2β2 type II enzyme was found to represent at least about 70% of the total prolyl 4-hydroxylase activity in cultured mouse chondrocytes and about 80% in mouse cartilage, the corresponding percentage in mouse bone being about 45% and that in many other mouse tissues about 10% or less. Immunofluorescence studies on samples from a fetal human foot confirmed these data and additionally indicated that the type II enzyme represents the main or only enzyme form in capillary endothelial cells. Thus the type II prolyl 4-hydroxylase is likely to play a major role in the development of cartilages and cartilaginous bones and also of capillaries.

Huanjiao Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Influence of prolyl hydroxylase 2 expression on endothelial barrier dysfunction induced by high glucose in human retinal vascular endothelial cells
    Chinese Journal of Ocular Fundus Diseases, 2013
    Co-Authors: Xiao-ling Liang, Huanjiao Zhou
    Abstract:

    Objective To observe the influence of prolyl hydroxylase 2 (PHD2) expression on endothelial barrier dysfunction induced by high glucose in human retinal vascular endothelial cells (HRECs).Methods The HRECs were treated by different culture medium with various glucose concentrations (5 mmol/L glucose,5 mmol/L glucose +25 mmol/L mannitol,30 mmol/L glucose) as normal control group,mannitol control group and high glucose group,respectively.After the cells cultured for 24 and 48 hours,the protein levels of PHD2,hypoxia-inducible factor-1α (HIF-1α) and occludin was detected by Western blot; the expression of vascular endothelial growth factor (VEGF) in the supernatant was determined by enzyme-linked immuno sorbent assay (ELISA); the transcription levels of PHD2,HIF-1α,VEGF and occludin were determined by the reverse-transcription polymerase chain reaction (RT-PCR) ; the paracellular permeability between endotheliums was detected by 7 × 104 molecular weight FITC-dextran.Results Compared with normal control group,the protein level of PHD2 in mannitol control group and high glucose group firstly decreased and then increased,the protein level of HIF-1α increased while that of occludin decreased; the secretion of VEGF increased in high glucose group but not in mannitol control group (PHD2:F=7.618,8.627; P＜0.05.HIF-1α:x2=7.692,7.652; P＜0.05.occludin:F=23.23,7.317; P＜0.05.VEGF:F=10.768,4.562; P＜0.05).Compared with normal control group,the mRNA levels of PHD2,HIF-1α,VEGF and occludin in mannitol control group and high glucose group increased (PHD2:F=5.69,14.27; P＜0.05.HIF-1α:F=6.07,10.47; P＜0.05.VEGF:F=12.31,9.14; P＜0.05.occludin:F=8.77,8.00; P＜0.05).Compared with normal control group,the paracellular permeability of mannitol control group and high glucose group increased (x2 =20.57,F=56.09; P＜0.05).Conclusions High glucose induced altered expression of PHD2 which might play an important role in endothelial barrier dysfunction.The mechanism might be associated with HIF-1α and VEGF. Key words: Procollagen-Proline Dioxygenase/antagonists & inhibitors; Vascular endothelial growth factors; Animal experimentation