Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.11.2 (prolyl hydroxylase)
 1,814 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 160 1-2 day old chickens were fed a 2% cholesterol diet for a period of 8 to 42 days and compared with an equal number of controls. Aortas were analyzed for various indexes of reactivity of connective tissue, cholesterol content and scanning electron microscopy (SEM) characteristics of the endothelial lining. Cholesterol feeding for a period up to 6 weeks resulted in doubling the level of serum cholesterol. It was, however, without effect on the activity of prolyl hydroxylase, lysyl oxidase, collagenase and collagen content in the aortic wall. As early as 3 weeks of feeding significant changes occurred in total and esterified cholesterol content. At the same time endothelial cells were characteristically contracted with several long cytoplasmic elongations and protrusions. A significant decrease of activity of the above enzymes was found in aortic tissue with increased age of the chicken. Collagen content in aortas increased with age of chickens. It is concluded that cholesterol as an atherogenic agent induces marked changes in endothelial cells and lipids of chicken aorta at earlier periods, prior to the activation of connective tissue.
 ...
PMID:Early changes in the arterial wall of chickens fed a cholesterol diet. 0 48

Two metabolically distinct types of bone cell populations were isolated from mouse calvaria by a repetitive digestive procedure with a mixture of collagenase and trypsin. Cells released early in the digestion showed approximately two-fold increases in cAMP when treated with either parathormone or calcitonin. These populations were denoted CT type. Later eluting cells showed larger parathormone-induced increases in cAMP but did not respond to calcitonin. These populations were denoted PT type. Six metabolic and enzymatic activites were measured in the two types of populations: acid and alkaline phosphatases, hyaluronate synthesis, citrate decarboxylation, prolyl hydroxylase, and general protein synthesis. Although each of these activites was present in both cell types, the basal levels of acid phosphatase and hyaluronate synthesis were higher in the CT cells, whereas alkaline phosphatase, citrate decarboxylation, and prolyl hydroxylase were higher in te PT cells. Parathormone stimulated acid phosphatase and hyaluronate synthesis by 100-200% only in the CT cells; in inhibited alkaline phosphatase, citrate decarboxylation, and prolyl hydroxylase by 75-90% only in the PT cells. Calcitonin alone had no effect on any of these activities other than cAMP production, but in inhibited the action of parathormone in the CT cells. The sensitivities, time courses of development,and magnitudes of these hormonal effects were similar to those observed previously in intact calvaria, indicating that the isolated cell system is a reliable model for the study of bone metabolism. Based on the metabolic responses of the cells, we postulate that the CT type of populations is enriched in osteoclasts and, possibly, osteocytes, and the PT type of population is enriched in osteoblasts.
 ...
PMID:Biochemical characterization with parathormone and calcitonin of isolated bone cells: provisional identification of osteoclasts and osteoblasts. 18 58

Increased aortic and liver prolyl hydroxylase activity has been suggested as an early biochemical indicator of the fibrotic changes which occur in rabbits with injury induced arteriosclerosis. Daily administration of epinephrine (0.025-0.050 mg/kg, i.v.) and thyroxine (0.050 mg/kg, i.p.) to rabbits for 3 weeks produced aortic fibrous plaques with a 4-fold increase in aortic prolyl hydroxylase and also a 5-fold increase in liver prolyl hydroxylase. Histopathologically, the livers of these rabbits show subcapsular areas of necrosis. When total prolyl hydroxylase related antigen was measured. the increase in liver prolyl hydroxylase activity accounted for only a small portion of the total prolyl hydroxylase antigen. However, in the aorta a majority of the increase in antigen is due to the increased amount of enzyme. DNA content per aorta was unchanged and RNA content increased in the aortic tissue of the arteriosclerotic rabbits. However DNA and RNA levels increased 60% in the livers of arteriosclerotic rabbits. In vitro incorporation of radioactively labeled proline into collagenase digestable protein was at least 2-fold greater in aorta and liver minces from arteriosclerotic rabbits. Michaelis--Menten kinetic parameters were obtained for the liver prolyl hydroxylase purified by affinity chromatography from arteriosclerotic rabbits. The Km for the enzyme from treated animals was not significantly different from control. However, the Vmax of the enzyme purified from diseased liver was 4-fold greater when compared to controls.
 ...
PMID:Increased collagen synthesis and the kinetic characteristics of prolyl hydroxylase in tissues of rabbits with experimental arteriosclerosis. 18

Phenanthroline treatment of growing cultures of the free-living nematode Panagrellus silusiae was used to lower the degree of hydroxylation of nascent collagen chains at the polysomal level. Under these conditions, the bound pentasome-hexasome fraction provided substrate for prolyl hydroxylase. When this polysomal fraction was subsequently tested in a cell-free wheat germ system, collagenase-susceptible translation products were observed after sodium dodecyl sulfate-acrylamide gel electrophoresis. The electrophoretic mobilities of each of these four major collagen products were similar to four collagens that are isolated from intact cuticles. In addition, purified polysomal RNA that adhered to unmodified cellulose directed the synthesis of four pepsin-resistant polypeptides that had molecular weights that coincided with four pepsin-resistant collagens that can be purified from the cuticle of this species. Thus, the polysomal site of the messenger RNAs for the cuticular collagens of P. silusiae was located. Although precursor forms of the cuticular collagens were not produced in the cell-free system, the question whether additional amino acid segments occur on the primary translational products of the cuticular collagens in vivo remains open.
 ...
PMID:In vitro translation of nematode cuticular collagens. 21 7

The effect of the potent tumor promoter phorbol 12-myristate 13-acetate (PMA) on collagen synthesis, a differentiated property of chick embryo fibroblasts, was examined. Collagen synthesis, as measured by the rate of formation of [3H]hydroxyproline from [3H]proline, was found to be decreased in cells treated with PMA but not in cells treated with the parent alcohol phorbol. The decrease in collagenase-sensitive proteins was confirmed by polyacrylamide gel electrophoresis of cell lysates, indicating that the decrease could not be ascribed simply to an effect on prolyl hydroxylase. Although a decrease in collagen synthesis was observed after one day, five days were required for a maximal reduction to 20% of that of dimethyl sulfoxide-treated controls. The effect of PMA on collagen synthesis was reversible. It was therefore not the result of a permanent transformation of the cells or of the selection of a population of cells with a reduced capacity for collagen synthesis. Collagen synthesis was decreased in chick embryo fibroblasts transformed by Rous sarcoma virus. Treatment of these cells with PMA for 5 days brought about a further decrease to 50% of the level in dimethyl sulfoxide-treated transformed controls.
 ...
PMID:Decrease in collagen production in normal and Rous sarcoma virus-transformed chick embryo fibroblasts induced by phorbol myristate acetate. 21 32

Embryonic-chick tendon poly(A)-containing RNA was translated in the wheat-germ and mRNA-dependent rabbit reticulocyte-lysate systems. The ability of each system to synthesize polypeptides similar to pro-alpha chains of collagen was tested on the bases of electrophoretic mobility and susceptibility to highly purified bacterial collagenase. Very small amounts of polypeptides in the size range of pro-alpha chains were synthesized in the wheat-germ system, whereas efficient synthesis of two polypeptides similar to pro-alpha1 and pro-alpha2 chains was achieved in the reticulocyte lysate. The collagenous nature of the major high-molecular-weight products synthesized was demonstrated by their susceptibility to collagenase and ability to act as a substrate for purified collagen proline hydroxylase. Determinations of the relative amounts of these translation products suggest that the 2:1 ratio of pro-alpha1 and pro-alpha2 chains found in type I procollagen is reflected in proportional amounts of translatable mRNA for pro-alpha1 and pro-alpha2 chains. Comparisons of the electrophoretic mobilities of hydroxylated and unhydroxylated reticulocyte-lysate translation products were made with appropriate standards of hydroxylated and unhydroxylated procollagen polypeptides. The results suggest that, in common with a number of secreted proteins, procollagen is synthesized as pre-pro molecules consistent with the ;Signal Hypothesis'.
 ...
PMID:Translation of embryonic-chick tendon procollagen messenger ribonucleic acid in two cell-free protein-synthesizing systems. 22 70

Synovial cells derived from patients with either rheumatoid arthritis, or simple joint-trauma were grown in tissue culture. The rheumatoid osteoarthritic and non-arthritic synovial cells in cultured all had similar levels of prolyl hydroxylase activity. Following a 3 hour incubation with ascorbate (10(-4)M), prolyl hydroxylase activity was elevated to a similar extent in all synovial cell cultures examined. The activation of prolyl hydroxylase by ascorbate (10(-4)M) was accompanied by increased radioactive hydroxyproline formation and secretion into the media. Increased amounts of collagenase degradable radioactive protein were also secreted into the media, but no changes in total collagen synthesis (media plus cell layer) were observed as a result of ascorbate supplementation using this assay system.
 ...
PMID:Effect of ascorbic acid on prolyl hydroxylase activity, collagen hydroxylation and collagen synthesis in human synovial cells in culture. 23 May 53

A series of hydrolytic enzymes were compared with lysolecithin, glycerol monooleate, and inactivated Sendai virus for their ability to bring about the fusion of several human and mouse lymphoid cell lines. The agents were tried alone and in various combinations, and a variety of incubation conditions were tested to determine those optimal for fusion. Sendai virus was found to produce the best results with the mouse lymphoid cells; lysolecithin plus glycerol monooleate was slightly superior with the human lymphoid cells. A mixture of hyaluronidase plus collagenase produced low (2 to 6%), but significant, fusion of the human lymphoid cells; both the human and mouse lymphoid cell lines were found to contain relatively high amounts of prolyl hydroxylase, the enzyme which forms collagen from protocollagen. The maximum fusion obtained with the human cells was 16%; with a mouse plasmacytoma line, the maximum was 7.5%; and with a mouse leukemic line derived from L5178Y, the maximum was 60%.
 ...
PMID:Optimal conditions for the fusion of lymphoid cell lines. 24 Jul 76

The effect of ethanol feeding for a period of 6 months on parameters of hepatic collagen metabolism was studied in the rat. Ethanol feeding resulted in small increases in the fibrous and ground substance components of hepatic collagen as measured by increases in collagen-bound hydroxyproline and hexosamine, respectively. Liver histology revealagen proline hydroxylase and the incorporation of labeled proline into collagen by liver slices, both of which are associated with collagen synthesis, were not changed. Ethanol feeding resulted in increases in the concentration of protein and deoxyribonucleic acid in the Kupffer cells, but in no changes in collagenase activity. An increase in collagen degradation was suggested, however, by the increase in the urinary excretion of hydroxyproline and glycosaminoglycans found after 2 and 6 months of ethanol feeding, respectively. This study demonstrates that fatty infiltration of the liver in the rat, after prolonged ethanol feeding, is associated with increased deposition of chemically detectable collagen and evidence of increased collagen degradation, although no significant changes in parameters associated with hepatic collagen synthesis were found.
 ...
PMID:Changes in hepatic collagen metabolism in rats produced by chronic ethanol feeding. 55 49

The action of hydralazine on collagen prolyl hydroxylation was studied in a cell culture system using WI-38 fibroblasts. The prolyl hydroxylation level was determined by a method involving the digestion of collagen by bacterial collagenase and the examination of specific peptides. The presence of low concentrations of hydralazine (0.2 mM) in both "young" and "old" fibroblast cultures strongly inhibited collagen prolyl hydroxylation. The degree of inhibition was greater in serum-deficient cultures. No significant improvement in the degree of hydroxylation was observed by increasing either ascorbate or iron levels in the hydralazine-containing cultures in which hydroxylation was inhibited. Some of the reported side effects of hydralazine seen in patients might be related to its inhibitory effects on mixed function oxidative (MFO) hydroxylation systems. While the ascorbate dependence of the prolyl hydroxylase system of WI-38 decreased with the "age" of the culture, hydralazine inhibition of hydroxylation was dramatic with cultures of all "ages".
 ...
PMID:Collagen prolyl hydroxylation in WI-38 fibroblast cultures: action of hydralazine. 85 25


1 2 3 4 Next >>