101
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Abstract
The exocrine pancreatic function was investigated in 16 patients with progressive systemic sclerosis by means of a meal test (Lundh test) and in 9 of the patients by the secretin-cholecystokinin test as well. Gastrointestinal involvement with progressive systemic sclerosis was evaluated by esophageal manometry and by routine roentgenographic series of the small bowel. Fecal fat excretion measurement, the D-xylose absorption test, and a small-intestinal biopsy procedure were carried out. Duodenal juice was cultured and bacterial counts were estimated. One-third of the patients had reduced exocrine pancreatic function, but only four patients had unequivocally a reduction that could be of clinical importance. The results obtained with the meal test were in accordance with the secretin-cholecystokinin test, indicating a preserved capacity for endogenous stimulation.
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102
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García Díaz JD, Praga Terente M, Colina Ruizdelgado F, Lizasoaín Hernández M, Mesa Latorre J. [Nodular regenerative hyperplasia of the liver associated with a CREST syndrome with multiorgan involvement]. ANALES DE MEDICINA INTERNA (MADRID, SPAIN : 1984) 1989; 6:203-6. [PMID: 2577486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A 52 year old woman with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal hypomotility and telangiectasia) and visceral involvement of the kidneys, lungs and liver is presented. The hepatic implication was a focal nodular hyperplasia of the liver which is a component not frequently recognized. Another 4 cases of this syndrome, associated to different forms of scleroderma, were described previously. Because of the way in which this case developed, this disease should be suspected when alkaline phosphatase and gamma-glutamyltranspeptidase levels are elevated. We comment on the utility of the laparoscopy and liver biopsy in diagnosing the diseased and the situation found. Finally, we discuss the pathogenic implications of the disease with scleroderma, owing to the vascular mechanism.
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103
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Abstract
Sc1-70, an autoantigen in systemic sclerosis, may accelerate collagen gene transcription by virtue of its activity as a topoisomerase I (topo I), a DNA template-modifying enzyme. A survey of sequences corresponding to all or part of the known topo I binding sequence AGAACTTAGAGAAAATTTAAA in four fibrillar collagen genes (three of them dermal) and sixteen non-collagen genes showed a striking preponderance of the tetramer 5'-CTTA-3', comprising the core of this binding sequence, at the exon-intron junctions of the fibrillar collagen genes (59% compared with 16% in the control group). In addition, a non-random clustering of three potential topo I binding sites was seen within 350 base-pairs of 5' flanking DNA in the dermal collagen gene alpha 2(I), and a fourth site occurred in the promoter region of the alpha 1(III) gene. The findings suggest that a selective vulnerability to the action of Sc1-70/topo I is built into the structure of the dermal collagen genes.
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104
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Herrmann K, Schulze E, Haustein UF, Böhme HJ, Ziegler V. Origin of the enhanced activity of lysosomal beta-galactosidase in serum and skin in progressive systemic sclerosis. Arch Dermatol Res 1987; 279:299-302. [PMID: 3115193 DOI: 10.1007/bf00431221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In 14 patients with progressive systemic sclerosis (PSS) the activities of acid lysosomal glycosidases (alpha-, beta-galactosidase, beta-glucosidase, beta-glucuronidase, and beta-N-acetyl-glucosaminidase) were determined fluorometrically in serum, leukocytes, and skin tissue. The beta-galactosidase was the only enzyme which exhibited a significantly elevated activity in PSS serum and skin but not leukocytes, as compared to the control. The activity patterns of the studied glycosidases in serum were similar to those found in skin, but differ from the distribution of glycosidase activities in leukocytes. In cultured dermal fibroblasts derived from PSS patients, an elevated intracellular activity of beta-galactosidase was detected. These results suggest that the increased beta-galactosidase activity in the serum originates from the skin fibroblasts.
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105
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Matucci Cerinic M, Borsotti M, Barbieri R, Lombardi A. Angiotensin converting enzyme (ACE) in scleroderma. Clin Rheumatol 1987; 6:300-1. [PMID: 3040325 DOI: 10.1007/bf02201047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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106
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Stetler DA, Reichlin M, Berlin CM, Jacob ST. Autoantibodies against RNA polymerase I in scleroderma and Sjögren's syndrome sera. Biochem Biophys Res Commun 1987; 144:1296-302. [PMID: 3579959 DOI: 10.1016/0006-291x(87)91451-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Anti-RNA polymerase I antibodies were detected by radioimmunoassay in the sera of 8 out of 9 Sjögren's syndrome patients, 11 out of 19 individuals with scleroderma, and 19 out of 19 systemic lupus erythematosus patients. The results of the radioimmunoassay were confirmed by demonstrating the ability of the patients' IgG to inhibit RNA polymerase I activity in vitro. Sera from four patients in each category were also tested for reaction with individual subunits of RNA polymerase I. All 4 SLE sera, 3 out of 4 scleroderma sera and 1 out of 4 Sjögren's syndrome sera contained antibodies against the 65 kDa (S3) subunit of RNA polymerase I in addition to antibodies against one other subunit. Sera from the remaining scleroderma and Sjögren's syndrome patients tested in this assay contained only anti-S3 antibodies. These results demonstrate that anti-RNA polymerase I antibodies are characteristic of a variety of rheumatic autoimmune sera.
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107
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Kitabatake M, Ishikawa H, Uchiyama Y. Significant increase of urinary low-sulfated heparan-sulfate-related protein in patients with severe systemic scleroderma. DERMATOLOGICA 1987; 174:166-72. [PMID: 3108042 DOI: 10.1159/000249167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Radioimmunoassay with an antibody produced against urinary low-sulfated heparan-sulfate-related protein was devised and used to screen the heparan sulfate level in the urine of patients with systemic scleroderma. Patients with diffuse scleroderma, and patients also showing polymyositis/dermatomyositis had elevated values, whereas the value in patients with acrosclerotic scleroderma did not differ from that of the control population. In addition, an increase in this protein was associated with the positivity of anti-Scl-70 antibody. These findings suggest an important role for low-sulfated heparan sulfate in the pathobiology of severe systemic scleroderma.
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108
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Guldner HH, Szostecki C, Vosberg HP, Lakomek HJ, Penner E, Bautz FA. Scl 70 autoantibodies from scleroderma patients recognize a 95 kDa protein identified as DNA topoisomerase I. Chromosoma 1986; 94:132-8. [PMID: 2428564 DOI: 10.1007/bf00286991] [Citation(s) in RCA: 103] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sera of patients suffering from the autoimmune disease progressive systemic sclerosis (PSS) are known to contain autoantibodies which have been reported to recognize a 70 kDa antigenic protein, designated the Scl 70 antigen. By immunoblotting of nuclear extracts from HeLa cells with sera from scleroderma patients we observed that the size of the antigen present in such cells depends on the conditions of antigen isolation. When protease inhibitors were included in the extraction buffer, a 95 kDa protein was identified instead of a 70 kDa protein. When protease inhibitors were omitted, a number of polypeptides in the size range 66 to 95 kDa was found. Furthermore, antibodies which had been affinity purified on the 95 kDa antigen, crossreacted with the 66 to 95 kDa polypeptides. These results suggest that the smaller proteins were degradation products of the 95 kDa antigen. Immunofluorescence studies on PtK-2 cells with the antibody specific for the 95 kDa protein gave staining of nuclei, nucleoli and of chromosomes and the nucleolar organizer region in mitotic cells. Since this distribution of antigens within the nucleus was reminiscent of the intranuclear distribution of DNA topoisomerase I found by others we probed purified DNA topoisomerase I from calf thymus directly with the autoantibodies from PSS patients, and also the 95 kDa antigens of HeLa cell nuclei with antibodies raised against the bovine DNA topoisomerase I. From the crossreaction pattern observed with the different antigens and antibodies we conclude that DNA topoisomerase I is one of the antigenic components against which autoantibodies are formed in scleroderma patients.
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109
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Scagliusi P, Anelli P, Fasiello V, De Lucia M, Pipitone V. [Connective tissue diseases and HEp-2 antinuclear antibodies]. Minerva Med 1985; 76:999-1003. [PMID: 3873632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Some characteristics of antinuclear antibodies that might be of use for diagnostic and/or prognostic purposed were studied using indirect immunofluorescence on HEp-2 cells in 55 cases of various types of connective tissue disease. For each nuclear (homogeneous, speckled, granular, dotted, pulverulent and centromeric) and nucleolar fluorescence pattern (homogeneous, conglutinated and dotted), the following parameters were observed; C3 fixing capacity, degree of antibody affinity and sensitivity to RNAse, DNAse and trypsin. The results were very interesting, especially in relation to the diagnosis of progressive systemic sclerosis and of the related subsets, but were insufficient for reliable, conclusive prognostic evaluation.
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110
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Rothschild B, Thompson LD, Chesney M, Pifer D. Perturbation of fibrinolysis inhibitors in progressive systemic sclerosis. Med Hypotheses 1985; 16:253-60. [PMID: 2582228 DOI: 10.1016/0306-9877(85)90007-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Significance of fibrinolysis in pathophysiology of progressive systemic sclerosis (PSS) has been the subject of much speculation. Renal disease in PSS was associated with significant depression of an inhibitor of fibrinolysis, antithrombin III (ATIII), independent of general disease activity. Association of ATIII depression with plasminogen consumption supports an active role for plasmin or another ATIII-inhibitable enzyme in the pathophysiology of renal disease in PSS, and may explain the thrombotic tendency and propensity for fibrin deposition.
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111
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Elwany S, Talaat M, Kamel N, Stephanos W. Further observations on nasal mucosal changes in scleroderma. A histochemical and electron microscopic study. J Laryngol Otol 1984; 98:879-86. [PMID: 6481226 DOI: 10.1017/s0022215100147644] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The respiratory nasal mucosa of patients with scleroderma showed several ultrastructural and histochemical changes. These included initial goblet cell hyperplasia, loss of cilia and microvilli, exfoliation of the superficial epithelial layers, increased glandular activity in cases with squamous metaplasia and fibrous tissue deposition in the lamina propria. These changes seem to be related to the duration of the disease, whose nature and pathogenesis are still uncertain.
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112
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Dupont M, Jover B, Mialanes N, Mimran A. [Clinical value of the estimation of plasma converting enzyme activity]. PATHOLOGIE-BIOLOGIE 1984; 32:698-701. [PMID: 6087253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Plasma angiotensin I-converting enzyme "activity" (CEA) was estimated as its enzymatic effect on the synthetic substrate HHL in normal subjects and patients with untreated sarcoidosis, alcoholic decompensated liver cirrhosis and scleroderma. CEA was above the upper limit of normal in 60% of sarcoidosis cases and 30% of cirrhotics; it was within normal in scleroderma. The assessment of the influence of chloride concentration on CEA showed that maximum was obtained for a concentration of 300 mM. In addition the inhibitory effect of angiotensin I and the converting enzyme inhibitors SQ 14225 and MK 422 was demonstrated together with the action of high concentrations of penicillamine. The inhibitory influence of these substances was similar when added to the plasma of normal or sarcoidosis subjects.
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113
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Gertler PA, Jacobs RP. Myoadenylate deaminase deficiency in a patient with progressive systemic sclerosis. ARTHRITIS AND RHEUMATISM 1984; 27:586-90. [PMID: 6721890 DOI: 10.1002/art.1780270518] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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114
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König G, Luderschmidt C, Hammer C, Adelmann-Grill BC, Braun-Falco O, Fruhmann G. Lung involvement in scleroderma. Chest 1984; 85:318-24. [PMID: 6321113 DOI: 10.1378/chest.85.3.318] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Lung involvement (LI) was studied by lung function (LF) in 101 scleroderma patients (circumscribed scleroderma, n = 17; progressive systemic scleroderma [PSS], n = 84; with the subtypes I, acroscleroderma [n = 19]; 2, proximal ascending scleroderma [n = 61]; 3, trunk scleroderma [n = 4]). Eighteen percent of morphea, 32 percent of type 1, 56 percent of type 2, and 75 percent of type 3 patients had impaired LF. The LI was more frequent (57 percent vs 45 percent) and more severe (20 percent vs 3 percent) in PSS with systemic inflammation (form A) compared to those without (form B). Elevated lymphocytes/neutrophils in bronchoalveolar lavage (BAL) were found associated with form A and severe LI. The LF of patients showing an inflammatory cell pattern in initial BAL (n = 3) worsened, whereas those with normal BAL findings (n = 4) did not. Collagenase activity in BAL was significantly elevated in those with elevated lymphocytes/neutrophils in lavage. Patients with type 2 or 3 of PSS, especially form A, carry a higher risk of developing severe LI than circumscribed scleroderma, type 1, or form B patients. Differential cell count and collagenase activity in BAL is correlated with active disease and provides prognostic information.
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115
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Altmann H. [Poly-(ADP ribose) synthesis and regulation disorders in disease]. Wien Klin Wochenschr 1983; 95:861-4. [PMID: 6422646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Poly(ADP-ribose) is a polyanion involved in the regulation of the DNA metabolism of cells. DNA repair, semiconservative DNA-synthesis, differentiation- and trans-formation functions are connected to changes in the activity of the poly(ADP-ribose)-polymerase. The incidence of most cancers shows a steady increase with age while the PAR-synthesis decreases linear in certain cells with age. In some diseases abnormalities could be detected in PAR-synthesis and binding to nuclear proteins.
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116
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Ermakova TM, Kovaleva VL, Brezhneva EG, Evstaf'eva OL, Alekseev IV. [Clinical evaluation of N-acetyltransferase activity in children with various forms of diffuse connective tissue diseases]. PEDIATRIIA 1983:10-3. [PMID: 6669424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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117
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Sosnovskiĭ AT, Soroka NF. [Isoenzyme spectra of lactate and malate dehydrogenases in focal and systemic scleroderma]. VESTNIK DERMATOLOGII I VENEROLOGII 1983:8-11. [PMID: 6868822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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118
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Rimbau E, Aubía J, Llorach I, Lloveras J, Masramón J, Orfila MA, Llorach M. [Effectiveness of the angiotensin converting enzyme inhibitor in sclerodermic crisis]. Med Clin (Barc) 1983; 80:89. [PMID: 6302410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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119
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Herrmann K, Haustein UF, Böhme HJ, Lohrisch I. Acid lysosomal hydrolases in systemic sclerosis and other connective tissue diseases. Br J Dermatol 1982; 106:523-8. [PMID: 7073977 DOI: 10.1111/j.1365-2133.1982.tb04554.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The activities of five lysosomal hydrolases were determined fluorometrically in the serum of patients with systemic sclerosis (PSS), systemic lupus erythematosus (SLE), dermatomyositis (DM), rheumatoid arthritis (RA), or Raynaud's disease (RD). In PSS the beta-galactosidase activity was significantly increased compared with controls and the other connective tissue diseases. The beta-N-acetyl-glucosaminidase was significantly increased in PSS, SLE and DM. In PSS both enzymes were more active in the early stage of the disease than later. These changes of enzyme pattern seem to be a relatively reliable marker for the differential diagnosis of PSS compared to other connective tissue diseases, especially for RD, in which the beta-galactosidase activity was significantly decreased. Further work is required to determine whether these polysaccharide-degrading acid hydrolases play a role in the pathogenesis of PSS.
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120
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Bernstein RM, Steigerwald JC, Tan EM. Association of antinuclear and antinucleolar antibodies in progressive systemic sclerosis. Clin Exp Immunol 1982; 48:43-51. [PMID: 7044633 PMCID: PMC1536562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Antinuclear and/or antinucleolar antibodies were demonstrated in the sera of 74 of 76 patients (97%) with progressive systemic sclerosis, using tissue culture cells (HEp-2) as substrate in the indirect immunofluorescent method. Six patterns of nuclear staining and three nucleolar patterns were recognized. The nuclear patterns were centromere, fine speckles, coarse speckles, diffusely grainy, homogeneous and nuclear dots. The nucleolar patterns were speckled, homogeneous and clumpy. The results of digestion studies with ribonuclease, deoxyribonuclease and trypsin suggested that the nuclear antigens are proteins, some of which may be associated with chromatin. The nucleolar antigens appeared to be nucleic acid in nature. Certain characteristic serologic and clinical features associated with staining patterns were observed. The diffusely grainy pattern was seen only in sera containing antibody to Scl-70 antigen. Centromere staining was confirmed to be highly selective for the CREST (Calcinosis, Raynaud's phenomenon, esophageal involvement, sclerodactyly and telangiectasis) variant of progressive systemic sclerosis with rheumatoid factor titres higher in these patients with anti-centromere antibodies.
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121
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Chitrabamrung S, Rubin RL, Tan EM. Serum deoxyribonuclease I and clinical activity in systemic lupus erythematosus. Rheumatol Int 1981; 1:55-60. [PMID: 6287560 DOI: 10.1007/bf00541153] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Serum deoxyribonuclease I (DNase I) activity in systemic lupus erythematosus (SLE) patients was shown to be lower than that of healthy laboratory personnel, rheumatoid arthritis, and scleroderma patients (P less than 0.001). The decrease in DNase I activity in SLE sera was not due to the effect of various autoantibodies or to heat labile DNase I inhibitor. A relationship between serum DNase I activity and active SLE was demonstrated. Patients with active lupus nephritis had the lowest levels of enzymatic activity.
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122
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Herrmann K, Didt L, Haustein UF. [Beta-Galactosidase activity in serum of systemic sclerosis (author's transl)]. DERMATOLOGISCHE MONATSCHRIFT 1981; 167:91-5. [PMID: 6785118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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123
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Oriente P, Riccio A, Scarpa R, Postiglione L, Spanò A, Pucino A. Evaluation of serum monoamine oxidase in patients with connective tissue diseases. Clin Chem 1980; 26:1514-5. [PMID: 7408185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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124
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Bülow BB, Boström H, Herbai G, Persson B, Wollheim F, Oberg K. Cyclofenil in the treatment of scleroderma - a general view on the results after treating 29 cases. Z Rheumatol 1980; 39:1-8. [PMID: 7424193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Results are presented from an open treatment of 29 patients suffering from progressive systemic sclerosis (PSS) with cyclofenil, an oestrogenlike non-steroid compound with very low oestrogenicity, which was recently claimed to be effective in this disorder. The treatment resulted in significant improvement of the skin condition and regress of ulcerations, Raymaud's phenomenon, joint pain and stiffness. Most of the patients experienced an increased sense of well-being. A slight elevation of ASAT and ALAT was noted in seven patients and weight gain in two. Present data do not permit an assessment of whether the treatment might influence the visceral changes. A multi-centre controlled study is in progress.
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125
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Uitto J, Bauer EA, Eisen AZ. Scleroderma: increased biosynthesis of triple-helical type I and type III procollagens associated with unaltered expression of collagenase by skin fibroblasts in culture. J Clin Invest 1979; 64:921-30. [PMID: 90059 PMCID: PMC372200 DOI: 10.1172/jci109558] [Citation(s) in RCA: 203] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
To assess potential abnormalities in collagen metabolism in systemic scleroderma, skin fibroblast lines from patients with this disease were established and compared to control cell lines derived from healthy subjects. For studies on the biosynthesis of procollagen, the cells were incubated with [(14)C]proline in a medium supplemented with ascorbic acid and beta-aminopropionitrile, and the synthesis of nondialyzable [(14)C]hydroxyproline, in relation to DNA or cell protein, was taken as an index of procollagen formation. Five of eight scleroderma fibroblast cell lines demonstrated procollagen biosynthesis rates significantly higher than the controls, and the mean rate of procollagen synthesis by scleroderma fibroblasts was about twice that of the control cells. Control experiments demonstrated that the specific activity of the intracellular free proline was not different in scleroderma and control fibroblasts, and the mean population doubling times of the scleroderma and the control fibroblast cell lines were the same. The relative synthesis of the genetically distinct procollagens was examined by isolating type I and type III procollagens from the cell culture medium using DEAE-cellulose chromatography. The ratios of type I/III procollagens in scleroderma cell lines did not differ from the controls. The helical stability of the collagenous portion of type I and type III procollagens, estimated by the resistance of (14)C-collagen to limited proteolytic digestion with pepsin under nondenaturing conditions, was the same in both scleroderma and control cultures. The capacity of the cells to synthesize enzymatically active and immunologically reacting collagenase was also studied; no marked differences in these parameters could be observed. The results suggest that cultured skin fibroblasts from patients with scleroderma demonstrate a metabolic abnormality expressed as increased synthesis of type I and type III procollagens in a normal ratio. This abnormality may play a role in the excessive accumulation of collagen in the skin and other organs affected in scleroderma.
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