scholarly journals Uridine diphosphoglucose dehydrogenase activity in synovial lining cells in the experimental antigen induced model of rheumatoid arthritis: an indication of synovial lining cell function.

1992 ◽  
Vol 51 (8) ◽  
pp. 992-995 ◽  
Author(s):  
A A Pitsillides ◽  
S M Blake
Keyword(s):  
Rheumatoid Arthritis ◽  
Dehydrogenase Activity ◽  
Cell Function ◽  
Synovial Lining ◽  
Synovial Lining Cells ◽  
Synovial Lining Cell

scholarly journals Possible Origin of Synovial Lining Cell Hyperplasia in Rheumatoid Arthritis

1987 ◽  
Vol 80 (8) ◽  
pp. 477-478
Author(s):  
D W Howat
Keyword(s):  
Rheumatoid Arthritis ◽  
Mitotic Activity ◽  
Tritiated Thymidine ◽  
Rabbit Model ◽  
Synovial Lining ◽  
Cell Hyperplasia ◽  
Synovial Lining Cells ◽  
Synovial Lining Cell

A perplexing feature of rheumatoid arthritis is the increase in the number of synovial lining cells with no mitotic activity. This feature has been investigated in the rabbit model. Rabbits with the established condition were injected into the affected joint with tritiated thymidine and killed either up to 24 hours later, or at 3 or 7 days. The location of labelled cells, detected by autoradiography, showed the label predominantly in the stroma in the former, and mainly in the lining cells in the latter, indicating that the lining cells were derived by recruitment from active cells deep in the stroma.

scholarly journals Biologically active thrombomodulin is synthesized by adherent synovial fluid cells and is elevated in synovial fluid of patients with rheumatoid arthritis

Blood ◽  
1993 ◽  
Vol 81 (3) ◽  
pp. 726-733 ◽  
Author(s):  
EM Conway ◽  
B Nowakowski
Keyword(s):  
Rheumatoid Arthritis ◽  
Synovial Fluid ◽  
Protein C ◽  
Inflammatory Process ◽  
Biologically Active ◽  
Northern Analysis ◽  
Synovial Lining ◽  
Local Synthesis ◽  
Synovial Lining Cells ◽  
Synovial Fluid Cells

Abstract Thrombomodulin (TM) is a transmembrane glycoprotein that interacts with thrombin, thereby serving as a cofactor in the activation of protein C, a major physiologically relevant natural anticoagulant. Although initially described as a vascular endothelial cell receptor, TM has also been reported to be synthesized by several cells, including megakaryocytes, platelets, monocytes, neutrophils (PMN), mesothelial cells, and synovial lining cells. A prominent feature of rheumatoid arthritis (RA) is infiltration of PMN into the joint space. To determine whether TM might play a role in the inflammatory process, we examined synovial fluid for the presence of TM in 10 patients with RA and five patients with osteoarthritis (OA). We determined that the mean synovial fluid and plasma TM levels in the OA group were 23.5 ng/mL and 24.2 ng/mL, respectively, whereas those with RA had a significantly elevated mean synovial fluid TM level of 136.2 ng/mL as compared with the plasma TM concentration of 43.9 ng/mL (P < .05). Synovial fluid TM levels did not correlate with PMN counts (r = .261). Purified TM from synovial fluid was identical in molecular weight to plasma-derived TM and was biologically functional with respect to protein C cofactor activity. Using direct immunofluorescence, we determined that adherent cultured synovial fluid cells that are not monocytoid in origin express surface and cytoplasmic TM, thereby providing an alternative source of the protein. Biologic activity of the cell-surface TM was confirmed by acceleration of thrombin-dependent protein C activation. Northern analysis of RNA extracted from the cultured cells indicated that TM messenger RNA was present, suggesting local synthesis. Our results indicate that in RA-associated synovial effusions, biologically active TM is increased, the source of which may be from plasma, PMN, and/or synovial lining cells. TM may play a regulatory role either in fibrin deposition in the inflamed joint and/or in the progression of the inflammatory process.

The Third Dimension of Rheumatoid Arthritis

1970 ◽  
Vol 28 ◽  
pp. 338-339
Author(s):  
Jeanne M. Riddle ◽  
Gilbert B. Bluhm
Keyword(s):  
Rheumatoid Arthritis ◽  
Electron Microscopy ◽  
Membrane Surface ◽  
Three Dimensional ◽  
Joint Space ◽  
Cell Contact ◽  
Synovial Lining ◽  
Synovial Lining Cells ◽  
Third Dimension ◽  
Dynamic Quality

Our application of scanning electron microscopy to the investigation of synovial membrane surface topography in humans has yielded new morphologic information. Samples of synovium removed from patients with advanced rheumatoid arthritis exhibited projecting villi such as those depicted in Fig. 1 as a prominent feature of their three-dimensional microarchi-tecture. In addition, localized areas of fibrin deposition, large parallel folds and focal irregular cavities were observed. Synovial lining cells were protuberant, increased in number and variable in size with many larger synoviocytes evident. Individual synoviocytes or small clusters were separated by only narrow areas of intercellular matrix. Membrane activities such as erythrophagocytosis and pinocytosis, the latter illustrated in Fig. 2, attested to the dynamic quality of the synovial lining cells as they participated in this inflammatory disease state. Frequently individual synovial lining cells were connected by slender, intercellular cytoplasmic spans. This form of cellular linkage illustrated in Fig. 2-was heretofore undiscovered by studies utilizing either light or transmission electron microscopy. Large finger-like structures depicted in Fig. 2 also jutted from some synoviocytes and either extended into the joint space or bridged gaps between adjacent synovial lining cells. In the latter situation, these filopodia perhaps served as a second type of adhesive cell contact as the layers of synoviocytes increased in depth.

scholarly journals Biologically active thrombomodulin is synthesized by adherent synovial fluid cells and is elevated in synovial fluid of patients with rheumatoid arthritis

Blood ◽  
1993 ◽  
Vol 81 (3) ◽  
pp. 726-733 ◽  
Author(s):  
EM Conway ◽  
B Nowakowski
Keyword(s):  
Rheumatoid Arthritis ◽  
Synovial Fluid ◽  
Protein C ◽  
Inflammatory Process ◽  
Biologically Active ◽  
Northern Analysis ◽  
Synovial Lining ◽  
Local Synthesis ◽  
Synovial Lining Cells ◽  
Synovial Fluid Cells

Thrombomodulin (TM) is a transmembrane glycoprotein that interacts with thrombin, thereby serving as a cofactor in the activation of protein C, a major physiologically relevant natural anticoagulant. Although initially described as a vascular endothelial cell receptor, TM has also been reported to be synthesized by several cells, including megakaryocytes, platelets, monocytes, neutrophils (PMN), mesothelial cells, and synovial lining cells. A prominent feature of rheumatoid arthritis (RA) is infiltration of PMN into the joint space. To determine whether TM might play a role in the inflammatory process, we examined synovial fluid for the presence of TM in 10 patients with RA and five patients with osteoarthritis (OA). We determined that the mean synovial fluid and plasma TM levels in the OA group were 23.5 ng/mL and 24.2 ng/mL, respectively, whereas those with RA had a significantly elevated mean synovial fluid TM level of 136.2 ng/mL as compared with the plasma TM concentration of 43.9 ng/mL (P < .05). Synovial fluid TM levels did not correlate with PMN counts (r = .261). Purified TM from synovial fluid was identical in molecular weight to plasma-derived TM and was biologically functional with respect to protein C cofactor activity. Using direct immunofluorescence, we determined that adherent cultured synovial fluid cells that are not monocytoid in origin express surface and cytoplasmic TM, thereby providing an alternative source of the protein. Biologic activity of the cell-surface TM was confirmed by acceleration of thrombin-dependent protein C activation. Northern analysis of RNA extracted from the cultured cells indicated that TM messenger RNA was present, suggesting local synthesis. Our results indicate that in RA-associated synovial effusions, biologically active TM is increased, the source of which may be from plasma, PMN, and/or synovial lining cells. TM may play a regulatory role either in fibrin deposition in the inflamed joint and/or in the progression of the inflammatory process.

PROPERTIES OF SYNOVIAL CELLS IN CULTURE

1971 ◽  
Vol 134 (3) ◽  
pp. 306-312 ◽  
Author(s):  
Carol A. Smith
Keyword(s):  
Rheumatoid Arthritis ◽  
Human Fibroblasts ◽  
Viral Persistence ◽  
Synovial Cells ◽  
Synovial Lining ◽  
Cellular Changes ◽  
Synovial Lining Cells ◽  
Synovial Membranes ◽  
And Cartilage

Derangements of synovial membranes and cartilage occur early in the course of rheumatoid arthritis. These important alterations of the joint tissues are probably the in vivo reflections of complicated inflammatory and immunological events. In our laboratory we have been interested in studying alterations of synovial lining cells in rheumatoid arthritis, most recently by the use of serially propagated cultures of these cells. The cellular traits described in such cultures serve to distinguish these synovial cells from other types of human fibroblasts, and several cellular alterations have been found in cultures derived from membranes of rheumatoid arthritic patients. One important finding is increased resistance of cultured rheumatoid cells to infection with rubella and NDV; this and other cellular changes suggest the possibility of an occult virus infection in the rheumatoid cells. Such viral persistence could be theoretically linked with the immunologic aberrations in rheumatoid arthritis, discussed in this symposium.

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