ascorbic-acid has been researched along with Ehlers-Danlos-Syndrome* in 23 studies
5 review(s) available for ascorbic-acid and Ehlers-Danlos-Syndrome
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The Ehlers-Danlos syndrome.
The Ehlers-Danlos Syndromes comprise a heterogeneous group of diseases, which are characterized by fragility of the soft connective tissues and widespread manifestations in skin, ligaments and joints, blood vessels and internal organs. The clinical spectrum varies from mild skin and joint hyperlaxity to severe physical disability and life-threatening vascular complications. The current Villefranche classification recognizes six subtypes, most of which are linked to mutations in one of the genes encoding fibrillar collagen proteins or enzymes involved in post-translational modification of these proteins. Establishing the correct EDS subtype has important implications for genetic counselling and management and is supported by specific biochemical and molecular investigations. Over the last years, the characterisation of several new EDS variants has broadened insights into the molecular pathogenesis of EDS by implicating genetic defects in the biosynthesis of other extracellular matrix molecules, such as proteoglycans and tenascin-X, or genetic defects in molecules involved in intracellular trafficking, secretion and assembly of extracellular matrix proteins. Topics: Ascorbic Acid; Collagen; Deamino Arginine Vasopressin; Ehlers-Danlos Syndrome; Gene Expression Regulation; Genetic Counseling; Hemostatics; Humans; Joints; Mutation; Protein Isoforms; Proteoglycans; Signal Transduction; Skin; Tenascin | 2014 |
[Vascular Ehlers-Danlos syndrome].
The vascular type of Ehlers-Danlos syndrome (EDS) is a rare genetic disease transmitted as an autosomal dominant trait. It is distinguished from other forms of EDS by its unstable acrogeric morphotype and by vascular, gastrointestinal, and obstetrical complications. Diagnosis is based on various clinical signs, noninvasive imaging, and on the identification of a mutation of the COL3A1 gene, which provides diagnostic certainty but has a sensitivity of only 61%. When two major diagnostic criteria are present, a genetic test should be proposed, performed and its result presented in a multidisciplinary group. The precautionary principle requires that preventive measures be implemented when the diagnosis is suspected. All artery puncture, surgery, and gastrointestinal and uterine endoscopy are contraindicated, permissible only in life-threatening emergencies. Straining against a closed glottis and all other situations or drugs likely to raise blood pressure must be avoided. Contraception must be discussed to avoid pregnancy during the diagnostic period. Arterial lesions suggestive of the disease include dissecting aneurysms of the internal carotid and iliac arteries and of the anterior visceral branches of the abdominal aorta, fusiform aneurysms of the splenic artery, and early onset nontraumatic direct carotid-cavernous fistulae. Early-onset varicose veins, spontaneous peritonitis or unusually important perineal lesions after giving birth should also attract the physician's attention. Psychological treatment and support of patients and their families is essential, to help them both to live with their disease and to deal with the information and screening issues. The prognosis of Ehlers-Danlos syndrome, vascular type, is grim but there is wide interindividual variability and life expectancy is best among patients receiving regular follow-up. Management by an experienced multidisciplinary team, implementation of drastic prevention measures and, depending on the results of the BBEST study, the possible prescription of beta-blockers should help to reduce the risk of complications and justify hope for a real improvement in prognosis in the near future. Topics: Adult; Ascorbic Acid; Celiprolol; Child; Clinical Trials as Topic; Collagen Type III; Contraception; Ehlers-Danlos Syndrome; Female; Genetic Counseling; Humans; Male; Mutation; Phenotype; Pregnancy; Pregnancy Complications; Prognosis; Tomography, X-Ray Computed; Ultrasonography, Doppler; Vasodilator Agents | 2006 |
Vitamin C and human wound healing.
Clinical studies provide evidence that wound healing in subjects judged not deficient in vitamin C can be significantly accelerated with supplements of this nutrient above the recommended daily allowance (RDA). The authors administered daily dosages of 500 to 3,000 mg., which is roughly 8 to 50 times the RDA of 60 mg., to subjects recovering from surgery, other injuries, decubital ulcers, and leg ulcers induced by hemolytic anemia. Genetic impairment of collagen synthesis has also been observed to be responsive to ascorbic acid supplementation in an 8-year-old boy with Type VI Ehlers-Danlos syndrome. Four grams of ascorbic acid daily produced a significant improvement in the quality of newly synthesized collagen but did not alter that formed prior to the supplementation of C. The combined evidence in this review provides a substantial base for further research, both clinical and experimental trials, concerning the interrelationships between vitamin C and the body's healing potential. Topics: Adult; Animals; Ascorbic Acid; Child; Collagen; Ehlers-Danlos Syndrome; Female; Guinea Pigs; Humans; Male; Middle Aged; Pressure Ulcer; Rabbits; Surgical Procedures, Operative; Time Factors; Wound Healing; Wounds and Injuries | 1982 |
Posttranslational protein modifications, with special attention to collagen and elastin.
It is apparent that significant progress has been made in our understanding of the biosynthesis, modifications, and maturation of collagen and elastin. We now recognize and partially understand special reactions involved in hydroxylations within the cell and complex cross-linking processes occurring outside the cell. Recent experiments (191) have shown that in human diploid fibroblast cultures of limited doubling potential (191) the hydroxylation of collagen prolyl residues appears to be "age" or passage-level dependent. With increasing passage level of these cultures, both the ascorbate requirements and the extent of collagen hydroxylation decrease. "Young" cell cultures have a strong requirement for complete hydroxylation and without ascorbate there is only about 50% of the normal level. "Middle-aged" cultures show higher hydroxylation without and full hydroxylation with ascorbate, whereas "old" (or cultures close to "senescence") are incapable of full hydroxylation with or without ascorbic acid. Although the overall system may show some deterioration with increasing passage levels, it appears that with increasing passage levels other components in the cell replace the ascorbate dependence of the hydroxylase system to a greater exten. In some ways, aging WI-38 cultures begin to resemble some transformed cells in their biochemical reactions, although they continue to remain diploid and eventually lose the ability to replicate. It is not yet known whether old animals can produce collagen, which may now be underhydroxylated, perhaps contributing to certain senescent changes. Careful examination of the hydroxylation index of collagen produced in organoid cultures of tissue biopsies as a function of donor age might be informative, particularly if one looks at the quality of collagen by employing collagenase and other proteolytic digests with collagen (191). One could comare the levels of frequent and characteristic peptide triplet sequences such as Gly-Pro-Hyp to Gly-Pro-Pro, Gly-Ala-Hyp to Gly-Ala-Pro, or Gly-Pro-Hyl to Gly-Pro-Lys and others for evaluation of hydroxylation throughout the entire molecule or at selected sequences. Topics: Amino Acid Sequence; Animals; Antibody Specificity; Ascorbic Acid; Collagen; Connective Tissue; Copper; Ehlers-Danlos Syndrome; Elastin; Epitopes; Homocystinuria; Humans; Hydralazine; Lathyrism; Marfan Syndrome; Molecular Conformation; Platelet Aggregation; Procollagen-Proline Dioxygenase; Skin Diseases; Syndrome | 1975 |
[Vascular hemorrhagic factors].
Topics: Ascorbic Acid; Avitaminosis; Blood Vessels; Cushing Syndrome; Diagnosis, Differential; Ehlers-Danlos Syndrome; Hemophilia A; Hemorrhagic Disorders; Humans; Purpura; Telangiectasia, Hereditary Hemorrhagic; Thrombocytopenia; Vascular Diseases | 1970 |
18 other study(ies) available for ascorbic-acid and Ehlers-Danlos-Syndrome
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Collagen remodelling and plasma ascorbic acid levels in patients suspected of inherited bleeding disorders harbouring germline variants in collagen-related genes.
Variants in collagen-related genes COL1A1, COL3A1, COL5A1 and COL5A2 are associated with Ehlers-Danlos syndrome (EDS), a heterogeneous group of connective tissue disorders strongly associated with increased bleeding. Of patients with incompletely explained bleeding diathesis, a relatively high proportion were shown to harbour at least one heterozygous variant of unknown significance (VUS) in one of these genes, the vast majority without meeting the clinical criteria for EDS.. To investigate the functional consequences of the identified variants by assessing the formation and degradation of types I, III and V collagen, in addition to plasma levels of ascorbic acid (AA).. A total of 31 patients harbouring at least one heterozygous VUS in COL1A1, COL3A1, COL5A1 or COL5A2 and 20 healthy controls were assessed using monoclonal antibodies targeting neo-epitopes specific for collagen formation and degradation. Plasma AA levels were measured in patients using high-performance liquid chromatography.. Functional investigations of collagen remodelling were not able to identify any clear associations between the identified variants and increased bleeding. The negative correlation between plasma AA levels and ISTH-BAT score motivates further investigations. Topics: Ascorbic Acid; Collagen; Collagen Type V; Ehlers-Danlos Syndrome; Germ Cells; Humans; Mutation | 2021 |
Vascular Ehlers-Danlos Syndrome: Treatment of a Complex Abdominal Wound with Vitamin C and Mesenchymal Stromal Cells.
Vascular Ehlers-Danlos syndrome (EDSv) can present with life-threatening surgical complications. The article describes the case of a patient with EDSv who developed total abdominal wound dehiscence and multiple enterocutaneous fistulas. Treatment with IV allogeneic mesenchymal stromal cells (MSCs) and high-dose vitamin C was trialed with success. Near-complete wound healing of the abdominal dehiscence with a 94% reduction in the size of the wound bed occurred. Maturation of the enterocutaneous fistulas also ensued.There is no current consensus on the management of large cutaneous wounds in EDSv. This article discusses the pathophysiology of wound healing with regard to nutrition requirements and growth factors with special reference to collagen deficits in EDSv. A potential therapy with IV vitamin C supplementation and MSCs is proposed following the patient's positive outcome. Medium-dose MSCs and high-dose IV vitamin C may offer significant benefits to complex and problematic wounds. Topics: Abdomen; Adult; Ascorbic Acid; Collagen; Ehlers-Danlos Syndrome; Humans; Male; Mesenchymal Stem Cells; Wound Healing | 2021 |
[Severe Mast Cell Activation Syndrome in a 15-year-old patient with an hypermobile Ehlers-Danlos syndrome].
We report the history of a 15-year old patient with a hypermobile Ehlers-Danlos syndrome (hEDS) (his mother, his two brothers and his sister have the same phenotype as him). He suffers mainly from a severe mast cell activation syndrome (MCAS) with an overreaction of the skin to any kind of contact (water of the shower, clothes, bed sheets) but he has also fatigue, headaches, and rash. This impressive rash is exacerbated after the shower and he has the urge to rest («shower's sign»). We describe the MCAS and its easy, fast and very effective medication management, without any significant side effects as well as its frequent association with the hEDS. We finally introduce the original term of «MASED» to this MCAS, associated, linked or entangled to hEDS.. Nous présentons le cas d’un jeune patient âgé de 15 ans atteint d’un syndrome d’Ehlers-Danlos (SED) de type hypermobile (sa mère, ses deux frères et sa soeur présentent le même phénotype que lui). Il présente principalement un syndrome d’activation mastocytaire (SAMA) sévère avec une atteinte démesurée au niveau de la peau exposée au simple contact (avec l’eau, les draps, les vêtements), mais également de la fatigue, des céphalées ainsi que des éruptions qui sont exacerbées après la douche avec l’envie impérieuse de se reposer (le «signe de la douche»). Nous décrivons le SAMA, sa prise en charge médicamenteuse simple, rapide et efficace et dépourvue d’effets secondaires notables ainsi que son association fréquente au SED. Nous introduisons finalement le terme original de «SAMED» à ce SAMA associé, lié ou intriqué au SED. Topics: Acetates; Adolescent; Antioxidants; Ascorbic Acid; Cetirizine; Cyclopropanes; Ehlers-Danlos Syndrome; Histamine H1 Antagonists, Non-Sedating; Histamine H2 Antagonists; Humans; Male; Mastocytosis; Quinolines; Ranitidine; Sulfides | 2018 |
A novel therapeutic strategy for Ehlers-Danlos syndrome based on nutritional supplements.
Ehlers-Danlos syndrome is a rare disorder, comprising a group of related inherited disorders of connective tissue, resulting from underlying abnormalities in the synthesis and metabolism of collagen. This proposal is specifically concerned with Ehlers-Danlos syndrome classic type (formerly Types I-III), which is characterized by joint hypermobility and susceptibility to injury/arthritis, skin and vascular problems (including easy bruising, bleeding, varicose veins and poor tissue healing), cardiac mitral valve prolapse, musculo-skeletal problems (myopathy, myalgia, spinal scoliosis, osteoporosis), and susceptibility to periodontitis. No treatment is currently available for this disorder. The novel aspect of this proposal is based on: (i) increasing scientific evidence that nutrition may be a major factor in the pathogenesis of many disorders once thought to result from defective genes alone; (ii) the recognition that many of the symptoms associated with Ehlers-Danlos syndrome are also characteristic of nutritional deficiencies; (iii) the synergistic action within the body of appropriate combinations of nutritional supplements in promoting normal tissue function. We therefore hypothesize that the symptoms associated with Ehlers-Danlos syndrome may be successfully alleviated using a specific (and potentially synergistic) combination of nutritional supplements, comprising calcium, carnitine, coenzyme Q(10), glucosamine, magnesium, methyl sulphonyl methane, pycnogenol, silica, vitamin C, and vitamin K, at dosages which have previously been demonstrated to be effective against the above symptoms in other disorders. Topics: Ascorbic Acid; Calcium; Carnitine; Coenzymes; Dietary Supplements; Ehlers-Danlos Syndrome; Flavonoids; Glucosamine; Humans; Magnesium; Plant Extracts; Silicon Dioxide; Ubiquinone; Vitamin K | 2005 |
Ehler-Danlos syndrome type VI variant presenting with recurrent respiratory infections and responding to high dose vitamin C.
Topics: Adolescent; Ascorbic Acid; Ehlers-Danlos Syndrome; Female; Humans; Recurrence; Respiratory Tract Infections | 1999 |
Abnormal formation of collagen cross-links in skin fibroblasts cultured from patients with Ehlers-Danlos syndrome type VI.
Ehlers-Danlos syndrome type VI (EDS VI) is an autosomal recessive disorder of connective tissue characterized by hyperextensible, friable skin and joint hypermobility. Severe scoliosis and ocular fragility are present in some patients. This disease is caused by defective collagen lsyl hydroxylase, a vitamin C-dependent enzyme that converts lysyl residues to hydroxylysine on procollagen peptides. Hydroxylysine is essential for the formation of the covalent pyridinium cross-links pyridinoline (Pyr) and deoxypyridinoline (Dpyr), among mature collagen molecules. Pyr derives from three hydroxylysyl residues, whereas Dpyr derives from one lysyl and two hydroxylysyl residues. Patients with EDS VI have high urinary excretion of Dpyr, resulting in a high ratio of Dpyr-Pyr. In this study, we evaluate content and production of pyridinium cross-links in the skin and cultured fibroblasts from patients with EDS VI. The skin of normal controls contained both Pyr and Dpyr, with a marked predominance of Pyr as observed in normal urine. The skin of patients with EDS VI had reduced total content of pyridinium cross-links, with the presence of Dpyr but not Pyr. Long-term cultures of control fibroblasts produced both Pyr and Dpyr, with a pattern resembling that of normal skin. By contrast, cross-links were not detected in dermal fibroblasts cultured from patients with EDS VI. Vitamin C, which improves the clinical manifestations of some patients with EDS VI, decreased Dpyr accumulation though only minimally affecting Pyr content in control cells. By contrast, addition of vitamin C to fibroblasts from patients with EDS VI stimulated the formation of Dpyr more than that of Pyr and greatly increased total pyridinium cross-link formation. These results indicate that qualitative and quantitative alterations of pyridinium cross-links occur in skin and in cultured dermal fibroblasts of patients with EDS VI and may be responsible for their abnormal skin findings. The vitamin C-stimulated production of Dpyr and Pyr in fibroblasts from patients with EDS VI may explain at least in part the therapeutic effects of this vitamin in EDS VI. Topics: Adolescent; Amino Acids; Ascorbic Acid; Cells, Cultured; Child; Collagen; Cross-Linking Reagents; Ehlers-Danlos Syndrome; Female; Fibroblasts; Humans; Hydroxylysine; Lysine; Pyridinium Compounds; Skin | 1997 |
A common duplication in the lysyl hydroxylase gene of patients with Ehlers Danlos syndrome type VI results in preferential stimulation of lysyl hydroxylase activity and mRNA by hydralazine.
Patients with Ehlers Danlos Syndrome type VI (EDS VI) are biochemically characterized by a deficiency of lysyl hydroxylase (LH), an enzyme that hydroxylates lysine residues required in the formation of stable crosslinks in collagen biosynthesis. Recently, in 19% of 35 EDS VI families, a duplication of seven exons in the LH gene has been identified as a common cause of EDS VI. We have observed that in fibroblasts from patients with this duplication mutation, administration of hydralazine, an iron-chelating agent, and ascorbate, a cofactor for LH activity, stimulates LH activity and its mRNA significantly more than in other EDS VI patients who do not have this duplication. Administration of these reagents, either singly or in combination, to fibroblasts from five patients homozygous for the duplication stimulated the low basal level of LH activity (<20% of normal) by five- to sixfold (hydralazine +/- ascorbate) and by twofold (ascorbate alone) at 72 h. This paralleled the increase in the steady-state level of mRNA for LH measured in similarly treated fibroblasts from four of these patients. In contrast, the activity of LH in fibroblasts from six other EDS VI patients and the mRNA from four of these patients who did not have the duplication were increased only three- to fourfold by hydralazine +/- ascorbate. The mechanism for the preferential stimulation of LH activity and mRNA by hydralazine in the EDS VI cells carrying the duplication is unknown, but it could be attributed to the presence of, for example, an enhancer sequence within the duplicated region of the LH gene. Topics: 2,2'-Dipyridyl; Ascorbic Acid; Blotting, Northern; Ehlers-Danlos Syndrome; Enzyme Activation; Fibroblasts; Humans; Hydralazine; Iron Chelating Agents; Multigene Family; Mutation; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; RNA, Messenger | 1997 |
The mRNA and the activity of lysyl hydroxylase are up-regulated by the administration of ascorbate and hydralazine to human skin fibroblasts from a patient with Ehlers-Danlos syndrome type VI.
Lysyl hydroxylase (LH) catalyzes the formation of hydroxylysine required for the intermolecular cross-linking of collagen, which is an essential step in collagen biosynthesis. Dermal fibroblasts from patients with Ehlers-Danlos Syndrome type VI (EDS VI), an inherited connective tissue disorder, express decreased levels of LH activity. In the present study we have shown that both the mRNA and the enzyme activity of LH in skin fibroblasts from one EDS VI patient (AT750), a compound heterozygote for the LH gene, are increased by administration of ascorbate and hydralazine, either individually or in combination. Although the AT750 cells express only 24% of the LH activity found in normal cells, a similar fold increase in activities in both EDS VI and normal cells was observed following treatment with ascorbate (1.5- to 2-fold) and hydralazine (2- to 4-fold), which paralleled the increase in their steady state LH mRNAs. Ascorbate increased total collagen production by 2-fold from a similar basal level of collagen synthesis in each cell type. This was confirmed by protein gel analysis which showed increases in pro alpha 1(I), pro alpha 2(I), and pro alpha 1(III) collagen chains in both normal and EDS VI cells. This ascorbate-mediated increase of alpha 1(I) collagen resulted from increased mRNAs for alpha 1(I) collagen in both cell types. Hydralazine treatment, with or without ascorbate, severely decreased the alpha 1(I) collagen mRNAs in fibroblasts from both AT750 and the normal donor; total collagen synthesis was similarly reduced. This study shows that LH activity, which is severely deficient in fibroblasts from an EDS VI patient, can be upregulated by administration of ascorbate and hydralazine as a result of the increased mRNA for LH, suggesting that the mechanism for the regulation of the LH gene is functioning normally in this patient. Topics: Ascorbic Acid; Blotting, Northern; Cell Line; Cells, Cultured; Collagen; Ehlers-Danlos Syndrome; Fibroblasts; Gene Expression; Gene Expression Regulation, Enzymologic; Humans; Hydralazine; Procollagen; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; Reference Values; RNA, Messenger; Skin | 1995 |
Transcriptional activation of type I collagen genes by ascorbic acid 2-phosphate in human skin fibroblasts and its failure in cells from a patient with alpha 2(I)-chain-defective Ehlers-Danlos syndrome.
L-Ascorbic acid 2-phosphate (Asc 2-P), a long-acting vitamin C derivative, stimulated transcription of genes for pro alpha 1(I) and pro alpha 2(I) collagen in normal human skin fibroblasts after 8 h of treatment in the absence or in the presence of cycloheximide, indicating Asc 2-P stimulates transcription of type I collagen genes in the absence of protein synthesis. The transcriptional rate in these cells reached the maximum value after 40 h of treatment, and at that time it was three to four times higher than that of the control cells cultured in the absence of Asc 2-P. Steady-state levels of mRNAs for pro alpha 1(I) and pro alpha 2(I) chains were also increased to be three to four times higher than the control levels by treatment of the cells with Asc 2-P for 72 h. When the fibroblasts obtained from a patient with Ehlers-Danlos syndrome were treated with Asc 2-P, the derivative also stimulated transcription of the gene for pro alpha 1(I) chain and accumulation of mRNA for pro alpha 1(I) chain. On the other hand, Asc 2-P failed to stimulate transcription of the pro alpha 2(I) gene or an increase in mRNA for pro alpha 2(I) chain. Sodium ascorbate showed effects quite similar to those of Asc 2-P, when fibroblasts obtained from a normal control or the patient were cultured for 16 h with it. These results indicate the existence of cis-regulatory elements responsible for transcriptional activation by Asc 2-P or ascorbic acid in pro alpha 1(I) and pro alpha 2(I) genes of normal fibroblasts. These data also suggest some defect(s) of these elements in the pro alpha 2(I) gene of the patient with Ehlers-Danlos syndrome. Topics: Ascorbic Acid; Blotting, Southern; Cell Division; Cells, Cultured; Collagen; Cycloheximide; DNA; Ehlers-Danlos Syndrome; Fibroblasts; Humans; RNA, Messenger; Skin; Time Factors; Transcription, Genetic | 1993 |
Ehlers-Danlos syndrome type VI with normal lysyl hydroxylase activity cannot be explained by a defect in cellular uptake of ascorbic acid.
The uptake of ascorbic acid by cultured skin fibroblasts from two siblings with Ehlers-Danlos syndrome type VI, in extracts of which there is no deficit in lysyl hydroxylase activity, was found to be normal. Decreased availability of ascorbic acid to lysyl hydroxylase in cellula cannot, therefore, provide an explanation for the disorder in these patients, the cause of which remains obscure. Topics: Adolescent; Adult; Ascorbic Acid; Ehlers-Danlos Syndrome; Female; Fibroblasts; Humans; Male; Mixed Function Oxygenases; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase | 1989 |
Ascorbate regulation of collagen biosynthesis in Ehlers-Danlos syndrome, type VI.
We studied two unrelated individuals with Ehlers-Danlos syndrome type VI, which is characterized by congenital hypotonia, lax joints, severe kyphoscoliosis, friable skin, and hemorrhagic hypotrophic scars. The diagnosis was confirmed by decreased hydroxylysine residues in dermal collagen and decreased collagen lysyl hydroxylase activities in their cultured skin fibroblasts. Despite the diminished hydroxylysine residues in dermal collagen from the probands, we found no differences in hydroxylysyl residues of collagen synthesized by fibroblasts in culture. When patient 1 was given oral sodium ascorbate (5 g/d) for 3 weeks, ascorbate concentrations increased two-fold in plasma and 300-fold in urine. Urinary excretion of hydroxylysine and hydroxyproline increased during ascorbate administration. After a 1-year interval, bleeding time, wound healing, and muscle strength improved. Ascorbate supplementation (50 micrograms/mL) to confluent fibroblasts cultured from the two patients and controls increased hydroxyprolyl and hydroxylysyl residues of fibroblasts four to seven and three to four-fold respectively. Total protein associated with the cell layer increased 14% to 32% without concomitant change in cellular DNA. Total soluble collagenous material recovered from culture media increased 61% to 103% with ascorbate supplementation. These studies demonstrate that ascorbate improves the clinical status of patients with impaired collagen lysyl hydroxylase activity by enhancing lysyl and prolyl hydroxylation and total collagen production. Topics: Amino Acids; Ascorbic Acid; Child; Child, Preschool; Collagen; DNA; Ehlers-Danlos Syndrome; Female; Fibroblasts; Humans; Male; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; Skin | 1987 |
Differences between proline and lysine hydroxylations in their inhibition by zinc or by ascorbate deficiency during collagen synthesis in various cell types.
The addition of Zn2+ inhibited lysine hydroxylation markedly less effectively than it did proline hydroxylation in chick embryo tendon cells, 3T6 fibroblasts and lysyl hydroxylase-deficient Ehlers-Danlos Syndrome Type VI fibroblasts. With low Zn2+ concentrations, a similar difference was also seen in chick embryo cartilage cells, whereas with high concentrations both hydroxylations were affected to the same extent in this cell type. Ascorbate deficiency likewise had a much less effect on lysine than proline hydroxylation when studied with 3T6 fibroblasts. As these two effectors involve quite different mechanisms, it is suggested that relative insensitivity to inhibition may be a property of lysine hydroxylation seen in many cell types with a number of agents. Studies on the mechanism of the difference in the inhibition indicates that the phenomenon is probably not due to differences in the kinetic constants of Zn2+ and ascorbate for the two enzymes. Neither is it probably to any major extent due to delayed procollagen triple helix formation nor a difference in the location of the two hydroxylases within the cisternae of the rough endoplasmic reticulum. The difference similarly cannot be explained solely by an excess of lysyl hydroxylase in the cell. It may thus be due either to some other intracellular property or to the combined effect of several factors. Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Cartilage; Cells, Cultured; Chick Embryo; Chickens; Collagen; Ehlers-Danlos Syndrome; Fibroblasts; Kinetics; Mice; Mixed Function Oxygenases; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; Procollagen-Proline Dioxygenase; Skin; Tendons; Zinc | 1981 |
Ascorbate action on normal and mutant human lysyl hydroxylases from cultured dermal fibroblasts.
Topics: Ascorbic Acid; Cells, Cultured; Ehlers-Danlos Syndrome; Female; Fibroblasts; Humans; Male; Mixed Function Oxygenases; Mutation; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; Procollagen-Proline Dioxygenase; Skin | 1979 |
Collagen synthesis by cultured skin fibroblasts from siblings with hydroxylysine-deficient collagen.
It has been previously shown that dermis from subjects with hydroxylysine-deficient collagen contains approximately 5% of normal levels of hydroxylysine and sonicates of skin fibroblasts contain less than 15% of normal levels of collagen lysyl hydroxylase activity. However, cultures of dermal fibroblasts from two siblings with hydroxylysine-deficient collagen (Ehlers-Danlos Syndrome Type VI) compared to fibroblasts from normal subjects synthesize collagen containing approximately 50% of normal amounts of hydroxylysine. The lysyl hydroxylase deficient cultures synthesize both Type I and Type III collagen in the same proportion as control cultures. Both alpha 1(I) and alpha 2 chains are similarly reduced in hydroxylysine content. Collagen prolyl hydroxylation by normal collagen lysyl hydroxylation is the same with or without ascorbate supplementation. In mutant cells the rate of prolyl hydroxylation measured after release of inhibition by alpha, alpha'-dipyridyl is the same as in control cells. The rate of lysyl hydroxylation is reduced in mutant cells but only to approximately 50% of normal. Topics: Ascorbic Acid; Collagen; Ehlers-Danlos Syndrome; Fibroblasts; Humans; Hydroxylation; Hydroxylysine; Hydroxyproline; Lysine; Proline; Skin | 1979 |
Inherited human collagen lysyl hydroxylase deficiency: ascorbic acid response.
A patient is described with congenital hypotonia, lax joints, friable skin, hemorrhagic scars, high-arched palate, and borderline microcornea. Acid hydrolyzed whole skin collagen had a reduced hydroxylysine content of 0.5 residues per 1,000 as compared to 5.1 +/- 0.7 in control skin. Collagen lysyl hydroxylase in dialyzed subcellular fractions of cultured skin fibroblasts required L-ascorbate as a principal cofactor. Activity of this enzyme in cultured skin fibroblasts derived from this patient, his father, and mother were 17%, 66%, and 39% of control values, respectively. Collagen prolyl hydroxylase activity was normal. Pharmacologic amounts of oral vitamin C (4 gm/day) produced an increase and withdrawal resulted in abrupt diminution of urinary excretion of hydroxylysine. Over a two-year period the patient's wound healing and muscle strength improved and corneal diameter increased. Hydroxylysine content of the skin did not increase. Topics: Ascorbic Acid; Child; Clinical Enzyme Tests; Ehlers-Danlos Syndrome; Female; Fibroblasts; Humans; Hydroxylysine; Male; Mixed Function Oxygenases; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; Skin | 1978 |
Abnormal properties of collagen lysyl hydroxylase from skin fibroblasts of siblings with hydroxylysine-deficient collagen.
Skin fibroblasts from two siblings with hydroxylysine-deficient collagen collagen (Ehlers-Danlos syndrome, type VI) contained normal levels of collagen prolyl hydroxylase activity but were markedly deficient in collagen lysyl hydroxylase activity. The deficiency was evident in all fractions of cell lysates, in low and high ionic strength buffers, and in detergent. Assays of mixtures of wild-type and mutant cell lysates indicated no activation of mutant enzyme by factors in wild-type cells or inhibition of normal enzyme by material in mutant cells. Wild type or mutant cells cultured with ascorbic acid (50 mug/ml of culture medium, added daily) contained approximately the same level of lysyl hydroxylase activity as cells cultured without ascorbate, but prolyl hydroxylase activity without ascorbate was depressed in both an average of 41%. The mutant lysyl hydroxylase was less stable at 37 degrees C than the wild type and did not form high molecular weight aggregates in low ionic strength buffers, as did the control enzyme. The activity of the mutant enzyme was maximally stimulated after dialysis against buffer solutions containing 10 mM dithiothreitol. When assayed in 100 muM dithiothreitol, the mutant enzyme exhibited a higher apparent Km for ascorbate (20 muM) than the wild type (4 muM). In 1.0 mM dithiothreitol the mutant enzyme's apparent Km for ascorbate was reduced to 5 muM. Wild type and mutant enzymes had the same apparent Km for alpha-keto-glutarate (20 muM). The properties of prolyl hydroxylase in wild type and mutant cells were identical: apparent Km's for ascorbate and alpha-ketoglutarate were 100 muM and 20 muM, respectively. If mutant enzyme protein with altered kinetic properties is the only enzyme functioning to hydroxylate lysyl residues in collagen, the variations in hydroxylysine content observed in collagen from different tissues in the subjects reported here could be in part due to differences in cofactor concentrations and in rate and sequence of events in collagen synthesis in different tissues. Topics: Ascorbic Acid; Chloromercuribenzoates; Collagen; Dithiothreitol; Ehlers-Danlos Syndrome; Fibroblasts; Humans; Hydroxylysine; In Vitro Techniques; Kinetics; Mercaptoethanol; Mixed Function Oxygenases; Mutation; Procollagen-Proline Dioxygenase | 1976 |
Simultaneous synthesis of types I and III collagen by fibroblasts in culture.
Specific antibodies against types I and III collagens and procollagens were used to localize these proteins in cultured human cells. These studies indicate that the same cell makes both proteins. No type III procollagen synthesis was observed in cells from two patients with two patients with the Ehlers-Danlos type IV syndrome. Topics: Ascorbic Acid; Cell Line; Collagen; Ehlers-Danlos Syndrome; Fibroblasts; Humans; Procollagen; Skin | 1976 |
[Efficacy of prolonged therapy with vitamins C and A and radiologic changes in the Ehlers-Danlos syndrome].
Two children of the same sex, almost of equal age, and suffering from the Ehlers-Danlos syndrome were followed up for a period of seven years. One of the children was subjected to a systematic treatment with vitamins C and A, Lipovitan, sulphuric mineral waters, and kinesitherapy. The non-treated child is serving as control person for the treated one. Thus it has been possible to evaluate the efficacy of the therapy administered to the first child and also to state the osseous progressive changes in the non-treated child. Topics: Arthrography; Ascorbic Acid; Bone and Bones; Child, Preschool; Ehlers-Danlos Syndrome; Female; Humans; Infant; Vitamin A | 1976 |