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(Journal of Leukocyte Biology. 2001;70:413-421.)
© 2001 by Society for Leukocyte Biology

Induction of fibroblast-like cells from CD34⁺ progenitor cells of the bone marrow in rheumatoid arthritis

Shunsei Hirohata^*, Tamiko Yanagida^*, Tatsuo Nagai, Tetsuji Sawada, Hiroshi Nakamura, Shin’ichi Yoshino, Tetsuya Tomita^|| and Takahiro Ochi^||

^* Department of Internal Medicine, Teikyo University School of Medicine,
Department of Allergy and Rheumatology, University of Tokyo School of Medicine, and
Department of Joint Disease and Rheumatism, Nippon Medical School, Tokyo;
Rheumatology and Immunology, Institute of Medical Science, St. Marianna University School of Medicine, Kanagawa; and
^|| Department of Orthopedic Surgery, Osaka University Medical School, Japan

Correspondence: Shunsei Hirohata, MD, Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan. E-mail: shunsei{at}med.teikyo-u.ac.jp

	ABSTRACT

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To assess the role of bone marrow in the pathogenesis of rheumatoid arthritis (RA), we examined the capacity of CD34⁺ cells from bone marrow to generate fibroblast-like type B synoviocytes. CD34⁺ cells from the bone marrow of 22 RA patients differentiated into cells with fibroblast-like morphology, which expressed prolyl 4-hydroxylase, in the presence of stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor (TNF-), much more effectively than CD34⁺ cells from bone marrow of 15 control subjects (10 patients with osteoarthritis and 5 healthy individuals). The generation of fibroblast-like cells was not at all observed in cultures with SCF, GM-CSF, and interleukin 4 (IL-4) with or without TNF-. Generation of fibroblast-like cells was correlated with matrix metalloproteinase (MMP)-1 levels in culture supernatants. Thus, MMP-1 levels were significantly higher in TNF--stimulated cultures of bone marrow CD34⁺ cells from patients with RA than in those from the control group. These results indicate that bone marrow CD34⁺ cells from patients with RA have abnormal capacities to respond to TNF- and to differentiate into fibroblast-like cells producing MMP-1, suggesting that bone marrow CD34⁺ progenitor cells might generate type B synoviocytes and thus could play an important role in the pathogenesis of RA.

Key Words: cytokines • matrix metalloproteinase 1 • prolyl 4-hydroxylase

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by hyperplasia of synovial lining cells [¹ ]. It is well known that synovial-lining cells consist of macrophage-like type A synoviocytes and fibroblast-like type B synoviocytes, and it has been suggested that type A synoviocytes are derived from monocyte precursors in the bone marrow [² ]. The spontaneous generation of CD14⁺ cells from bone marrow CD14^- progenitor cells is accelerated in patients with RA, resulting in facilitated entry of such CD14⁺ cells into the synovium [³ ]. On the other hand, type B synoviocytes have the morphologic appearance of fibroblasts as well as the capacity to produce and secrete a variety of factors, including proteoglycans, cytokines, arachidonic acid metabolites, and matrix metalloproteinases (MMPs), that lead to the destruction of joints [⁴ ]. Unlike type A synoviocytes, the precise origin of type B synoviocytes remains unclear, although they are thought to arise from the sublining tissue or other support structures of a joint [⁴ ].

Recent studies have demonstrated that the wnt5a-fz5 ligand-receptor pair, which has been implicated in bone marrow stem cell development [⁵ ], is overexpressed in both the synovium and fibroblast-like cell lines in patients with RA [⁶ ]. These researchers therefore suggest that the synovial membrane becomes repopulated with immature mesenchymal and bone marrow cells. On the other hand, a number of studies have shown that peripheral blood dendritic cells accumulate in the synovium, where they undergo phenotypic and functional differentiation in situ [⁷ , ⁸ ]. Previous studies have also shown that synovial dendritic cells gradually lose their distinct morphologic appearance and become indistinguishable from fibroblasts in vitro [⁹ ]. Moreover, Kyogoku et al. identified the presence of dendritic cell-like cells that strongly express major histocompatibility complex class II antigens and interact with T lymphocytes, in the sublining layers of the synovium affected by RA [¹⁰ ]. They also showed that the sublining dendritic cell-like cells proliferate and differentiate into type A as well as type B synoviocytes to replace the lining layers [¹⁰ ]. It is therefore possible that type B synoviocytes originate from dendritic cells, which differentiate from their precursors in the bone marrow.

We undertook this study to explore whether CD34⁺ progenitor cells in bone marrow from RA patients can differentiate into type B synoviocyte-like cells. The results clearly indicate that bone marrow CD34⁺ progenitor cells from RA patients, compared with those from osteoarthritis (OA) patients or healthy individuals, differentiate prominently into fibroblast-like cells on stimulation with stem cell factor (SCF), granulocyte-macrophage colony stimulating factor (GM-CSF), and tumor necrosis factor (TNF-). The data therefore suggest that synovial hyperplasia in RA might be a sequela of bone marrow abnormalities.

	MATERIALS AND METHODS

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Patients and samples
Bone marrow samples were obtained from 22 patients with RA (1 male and 21 females; mean age, 57.6 years; age range, 43–72 years) who satisfied the American College of Rheumatology 1987 revised criteria for RA [¹¹ ] and gave informed consent. The samples were taken during joint operations by intramedullary reaming via aspiration from a distal femoral canal prepared for implantation of an artificial femoral head or via aspiration from the iliac crest. As a control, bone marrow samples were similarly obtained during joint operations from 10 patients with OA (1 male and 9 females; mean age, 67.9 years; age range, 57–73 years) who gave informed consent. In addition, CD34⁺ cells derived from bone marrow aspirated from the iliac crests of 5 healthy individuals (3 males and 2 females; mean age, 29.0 years; age range, 19–43 years) and purified through positive selection with magnetic beads (purity >95%, as stated in manufacturer’s description) were purchased from BioWhittaker (Walkersville, MD). Cord blood samples were obtained for research use after normal deliveries with informed consent from parents.

Culture medium and reagents
RPMI 1640 medium (Life Technologies, Grand Island, NY) supplemented with penicillin G (100 U/mL), streptomycin (100 µg/mL), L-glutamine (0.3 mg/mL), and 10% fetal bovine serum (Life Technologies) was used for all cultures. Recombinant human GM-CSF, SCF, TNF-, and IL-4 were purchased from Pepro Tech EC (London, England).

Preparation and culture of bone marrow CD34⁺ cells
Mononuclear cells were isolated by centrifugation of heparinized bone marrow aspirates or cord blood over sodium diatrizoate-Ficoll gradients (Histopaque; Sigma Chemical Co., St Louis, MO). CD34⁺ cells were purified from the mononuclear cells by positive selection with magnetic beads (CD34 progenitor cell selection system; Dynal, Oslo, Norway). The cells thus prepared were >95% CD34⁺ cells and <0.5% CD19⁺ B cells, as previously described [¹² ]. CD34⁺ cells were incubated in a 24-well microtiter plate with flat-bottomed wells (No. 3524; Costar, Cambridge, MA) (10⁵/well) with the presence of SCF (10 ng/mL) and GM-CSF (1 ng/mL) but with or without TNF- (10 ng/mL) and IL-4 (10 ng/mL). After various periods of incubation, the cells were observed under phase-contrast microscopy, stained with various monoclonal antibodies (mAbs) and then analyzed with a flow cytometer. The culture supernatants were assayed for matrix metalloproteinase-1 (MMP-1) with the Biotrak human MMP-1 enzyme-linked immunosorbent assay system (Amersham Pharmacia Biotech, Buckinghamshire, United Kingdom).

Immunofluorescence staining and analysis
Cultured CD34⁺ cells (obtained from six RA patients, three OA patients, and two normal individuals) were harvested gently with a rubber policeman and stained with saturating concentrations of fluorescein isothiocyanate (FITC)-conjugated anti-human leukocyte antigen DR (HLA-DR) mAb (mouse immunoglobulin (Ig) G2b; Immunotech, Marseilles, France), phycoerythrin (PE)-conjugated anti-CD14 mAb (mouse IgG2a; Immunotech), or PE- or FITC-conjugated isotype-matched control mAbs (Dako, Glostrup, Denmark). Briefly, the cells were washed with 2% normal human AB serum in phosphate-buffered saline (PBS) (pH 7.2) and 0.1% sodium azide (staining buffer), and then the cells were stained with saturating concentrations of a variety of mAbs at 4°C for 30 min. Then the cells were washed three times with staining buffer and fixed with 1% paraformaldehyde in PBS for at least 5 min at room temperature. In some experiments, cultured bone marrow CD34⁺ cells that had been permeabilized in PBS (pH 7.2) containing 2% normal human AB serum, 0.1% sodium azide, and 0.1% saponin (Sigma) were stained with anti-prolyl 4-hydroxylase mAb (mouse IgG1; Dako) or control IgG1 (MOPC 21; Cappel Laboratories, West Chester, PA) and then counterstained with FITC-conjugated goat anti-mouse Ig (Cappel). The cells were analyzed using an EPICS XL flow cytometer (Coulter, Hialeah, FL) equipped with an argon-ion laser at 488 nm. A combination of low-angle and 90° light scatter measurements (forward scatter vs. side scatter) was used to generate a bit map gating to identify bone marrow cells using CYTO-TROL^TM Control Cells (Coulter) and Immuno-Trol^TM Cells (Coulter) as standards. The percentage of cells stained positively for each mAb was determined by integration of cells above a specified fluorescence channel that was calculated in relation to the isotype-matched control mAbs.

RNA isolation and reverse transcriptase-PCR of prolyl 4-hydroxylase gene
Total RNA was isolated from cultured cells using the RNeasy mini kit (QIAGEN, Tokyo Japan) according to the manufacturer’s instructions. Total RNA was then reverse transcribed using 200 U of Moloney murine leukemia virus reverse transcriptase (GIBCO BRL, Life Technologies, Grand Island, NY) and 40 pmol of oligo(dT) primer in a total volume of 50 µL. Reactions were carried out at 42°C for 1 h and then mixtures were heated to 95°C for 3 min to stop the reactions. To amplify the prolyl 4-hydroxylase gene expressed by the cells, 2 µL of cDNA were amplified using the sense primer (5'-GTGGAGTGAGTTGGAGAATC-3') in conjunction with the antisense primer (5'-GATGTTCAGGATCTAGTTCAAG-3'). The reactions were carried out in 20-µL solutions using 10 pmol of each primer and cycled with a 9700 GeneAmp System (Perkin-Elmer Cetus, Emeryville, CA) with the following conditions: denaturing at 94°C for 30 s, annealing at 55°C for 30 s, and extension at 72°C for 45 s. After 35 cycles, the extension was continued for an additional 10 min at 72°C. The first PCR reaction products were reamplified using the nested sense primer (5'-CCATCTCAAAGGGTAATCTTCCAGG-3') and antisense primer (5'-GCTTGTTCCATCCACAGTTCCG-3') under the same conditions, but the number of cycles was reduced to 15. As an internal control, ß-actin cDNA was also amplified using the sense primer (5'-ATGGCCACGGCTGCTTCCAGC-3') and the antisense primer (5'-CAGGAGGAGCAATGATCTTGAT-3') under the following conditions: denaturing at 94°C for 30 s, annealing at 55°C for 30 s, and extension at 72°C for 45 s. There was an additional extension for 10 min after 40 cycles. The PCR products were electrophoresed on a 1% agarose gel and stained with ethidium bromide. To confirm the correct amplification, the PCR product detected at the predicted position in an agarose gel was processed using a QIAquick PCR purification kit (QIAGEN), and then it was directly sequenced with an automated sequencer (Applied Biosystems, Foster City, CA).

	RESULTS

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Induction of fibroblast-like cells from bone marrow CD34⁺ cells
Figure 1 depicts the representative microscopic features of the CD34⁺ cells cultured for 4 weeks in the presence of SCF and GM-CSF with or without TNF- and IL-4. In cultures of CD34⁺ cells from bone marrow of healthy donors (data not shown) or OA patients or from cord blood (data not shown) that had been stimulated with SCF and GM-CSF for 4 weeks, most cells had the appearance of monocytes or dendritic cells, whereas very few cells with fibroblast-like morphology were induced (8%) (Fig. 1A) . In cultures of CD34⁺ cells from bone marrow of RA patients stimulated with SCF and GM-CSF for 4 weeks, a relatively high number of fibroblast-like cells was observed (15%) (Fig. 1B) . When TNF- was added to the cultures of CD34⁺ cells from bone marrow of OA patients that had been stimulated with SCF and GM-CSF, the formation of fibroblast-like cells was enhanced (20%) (Fig. 1C) . It is noteworthy that CD34⁺ cells from bone marrow of RA patients generated the fibroblast-like cells much more effectively than CD34⁺ cells from bone marrow of OA patients (55%) in the presence of SCF, GM-CSF, and TNF- (Fig. 1D) . When IL-4 was added to the cultures of CD34⁺ cells from bone marrow of OA patients stimulated with SCF and GM-CSF, almost all the cells developed round monocyte/immature dendritic-like cells in a cluster formation (Fig. 1E) . CD34⁺ cells from bone marrow of RA patients similarly generated clusters of monocyte/immature dendritic-like cells in the presence of SCF, GM-CSF, and IL-4 (Fig. 1F) . When both IL-4 and TNF- were added to the cultures stimulated with SCF and GM-CSF, the number of cells was markedly decreased, and the remaining cells showed large round shapes with some cluster formation irrespective of the origin of the CD34⁺ cells initially cultured (Fig. 1G and 1H) . It is noteworthy that CD34⁺ cells from >50% of the 22 RA patients piled onto each other to form clusters of fibroblast-like cells after stimulation with SCF, GM-CSF, and TNF- (Fig. 2 ).

View larger version (146K): [in this window] [in a new window]   Figure 1. Morphological changes of CD34+ cells cultured in the presence of SCF and GM-CSF with or without TNF- and IL-4. CD34+ cells from bone marrow of an RA patient or an OA patient (104/well) were cultured in the presence of SCF (10 ng/mL) and GM-CSF (1 ng/mL) with or without TNF- (10 ng/mL) and IL-4 (10 ng/mL) as described in Materials and Methods. After 4 weeks, the morphological changes were determined by phase-contrast microscopy. Original magnification, x50. CD34+ cells from bone marrow of an OA patient were cultured in the presence of no additive (A), TNF- (C) , IL-4 (E), and TNF- and IL- 4 (G). CD34+ cells from bone marrow of an RA patient were incubated with no additive (B), TNF- (D), IL-4 (F), and TNF- and IL-4 (H).

View larger version (117K): [in this window] [in a new window]   Figure 2. Morphological changes of CD34+ cells cultured in the presence of SCF, GM-CSF, and TNF-. CD34+ cells from bone marrow of RA patients (104 cells/well) were cultured in the presence of SCF (10 ng/mL), GM-CSF (1 ng/mL), and TNF- (10 ng/mL). After 4 weeks, the morphological changes were determined by phase-contrast microscopy. Original magnification, x50.

View larger version (44K): [in this window] [in a new window]   Figure 3. Representative two-color flow-cytometric analysis of the phenotypes of CD34+ cells cultured in the presence of SCF and GM-CSF with or without TNF- and IL-4. CD34+ cells from bone marrow of RA patients, of an OA patient, or of a healthy individual (104 cells/well) were cultured in the presence of SCF (10 ng/mL) and GM-CSF (1 ng/mL) with or without TNF- (10 ng/mL) and IL-4 (10 ng/mL). After 4 weeks, the cells were harvested and stained with PE-conjugated anti-CD14 and FITC-conjugated anti-HLA-DR and analyzed by flow cytometry. Controls include isotype control stained cells as shown in experiment 1 to determine the quadrant boundaries. The percentages of cells stained in the respective quadrants are indicated. Representative experiments of those with CD34+ cells from bone marrow of six RA patients, three OA patients, and two normal individuals are shown.

View larger version (9K): [in this window] [in a new window]   Figure 4. Concentrations of MMP-1 in the culture supernatants of CD34+ cells stimulated with SCF, GM-CSF, and TNF-. CD34+ cells from bone marrow of 16 RA patients or from 10 control subjects (6 OA patients and 4 healthy individuals) (104 cells/well) were cultured in the presence of SCF (10 ng/mL) and GM-CSF (1 ng/mL) with TNF- (10 ng/mL). After 4 weeks, the culture supernatants were harvested and analyzed for MMP-1 content by enzyme-linked immunosorbent assay. Statistical significance was determined with the Mann-Whitney U test.

View larger version (148K): [in this window] [in a new window]   Figure 5. Kinetic studies over time of the morphological changes of cells and the levels of MMP-1 in culture supernatants from cultures of CD34+ cells extracted from bone marrow of an RA patient. CD34+ cells from bone marrow of an RA patient were cultured in the presence of SCF (10 ng/mL), GM-CSF (1 ng/mL), and TNF- (10 ng/mL). After various times of incubation [1 week (1 W), 2 weeks (2 W), 3 weeks (3 W), and 4 weeks (4 W)], the morphological changes of the cells were determined by phase-contrast microscopy (original magnification, x100) (A) and the MMP-1 contents in the culture supernatants were analyzed with an enzyme-linked immunosorbent assay (B). Representative data of the three different experiments are shown.

View larger version (103K): [in this window] [in a new window]   Figure 6. Expression of prolyl 4-hydroxylase in CD34+ cells cultured in the presence of SCF, GM-CSF, and TNF-. CD34+ cells from bone marrow of a patient with RA and a healthy individual were cultured in the presence of SCF (10 ng/mL), GM-CSF (1 ng/mL), and TNF- (10 ng/mL). After 4 weeks of incubation, the cells were harvested and subjected to reverse transcriptase-PCR for detection of prolyl 4-hydroxylase gene expression (A). Alternatively, the stimulated bone marrow CD34+ cells were permeabilized, stained with anti-prolyl 4-hydroxylase mAb (open area) or isotype-matched control mAb (shaded area) and then counterstained with FITC-conjugated goat anti-mouse Ig. The cells were then analyzed by flow cytometry (C). Representative data of three different experiments are shown. (A) M, marker (x174); lane 1, CD34+ cells from bone marrow of a healthy individual (fresh); lane 2, CD34+ cells from bone marrow of healthy individuals (stimulated); lane 3, CD34+ cells from RA patients (fresh); lane 4, positive control (synovial fibroblast). The arrow indicates the position of specific prolyl 4-hydroxylase PCR product. (B) Photomicroscopy (original magnification, x50) shows the appearance of the cells induced by stimulation of fresh CD34+ cells from bone marrow of healthy individuals (i.e., panel A, lane 1) and from patients with RA (i.e., panel A, lane 3) with SCF, GM-CSF, and TNF- for 4 weeks. (C) RA, Cells induced by stimulation of fresh RA bone marrow CD34+ cells as shown in lane 3 of panel A; Control, cells induced by stimulation of fresh CD34+ cells from bone marrow of normal individuals, the same as shown in lane 2 of panel A.

	DISCUSSION

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The purity of the CD34⁺ cell population was between 95 and 100% in the present study. Thus, it is possible that a small number of fibroblast cells were contaminated in the CD34⁺ cell population, which might give rise to development of fibroblast-like cells after stimulation with SCF, GM-CSF, and TNF-. However, reverse transcriptase-PCR analysis failed to detect expression of the prolyl 4-hydroxylase gene in purified bone marrow CD34⁺ cells, obviating the possibility that the CD34⁺ cells might have been contaminated with fibroblasts. It is most likely therefore that CD34⁺ progenitor cells from bone marrow of RA patients carry precursors for fibroblast-like cells. The data in the present study indicate at least that there are considerably more precursors for fibroblast-like cells in the bone marrow of RA patients than in the bone marrow of OA patients or healthy individuals, thus underscoring the importance of bone marrow in the pathogenesis of RA.

In the past decade, the importance of TNF- in the pathogenesis of RA has been increasingly appreciated [²³ ]. Thus, anti-TNF- mAbs and soluble TNF receptors have been demonstrated to have beneficial effects in the treatment of RA [²⁴ ]. The results in this study also revealed that CD34⁺ cells from bone marrow of RA patients have abnormal responsiveness to TNF-, resulting in their differentiation into fibroblast-like cells and producing MMP-1, although the precise sequelae of abnormal responses of CD34⁺ cells from bone marrow of RA patients to TNF- remain unclear. Further studies that explore in detail the mechanism of these abnormalities in response to TNF- of CD34⁺ cells from bone marrow of RA patients would be helpful in gaining a complete understanding of the mechanism of action of anti-TNF- treatment as well as the etiology and pathogenesis of RA.

It has been suggested on the basis of animal models of inflammatory arthritis that there might be channels between the bone marrow and the synovium that allow migration of bone marrow stem cells with different properties into the synovium [⁶ , ²⁵ ]. However, the presence of such channels has not been detected in all the joints, nor has their presence been demonstrated in humans with RA. On the other hand, it also has been shown that peripheral blood CD14⁺ CD34⁺ cells themselves, which might be derived from bone marrow CD34⁺ progenitor cells, can be recruited across endothelial cells to give rise to immunostimulatory dendritic cells [²⁶ ]. It also has been demonstrated that SCF, GM-CSF, and TNF- are all produced in the synovia of patients with RA [²³ , ²⁷ , ²⁸ ]. It is therefore likely that precursors for type B synoviocytes derived from bone marrow are recruited into the synovium, where they undergo terminal differentiation into type B synoviocytes under the influences of various cytokines, including TNF-. Alternatively, it is also possible that bone marrow-derived dendritic cells that are recruited into the synovium [⁸ ] differentiate into type B synoviocytes under the influence of TNF-. In fact, previous studies have shown that synovial dendritic cells become indistinguishable from fibroblasts [⁹ ]. Taken together, these results support the hypothesis that the bone marrow, but not the synovium, is the primary-lesion site of RA. In fact, there is accumulating evidence that bone marrow transplantation results in prolonged remission in human RA patients [²⁹ , ³⁰ ]. Of course, further studies are required to identify the routes by which bone marrow derived cells might be recruited to the synovium.

	ACKNOWLEDGEMENTS

 
This study was supported by the Program for Promotion of Fundamental Studies in Health Sciences of the Organization for Drug ADR Relief, R&D Promotion and Productive Review of Japan, and by a grant from Manabe Medical Foundation, Tokyo, Japan. The authors thank Chise Kawashima for preparing the manuscript and illustrations.

Received January 2, 2001; revised April 4, 2001; accepted April 5, 2001.

	REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 

1. Firestein, G. S., Zvaifler, N. J. (1990) How important are T cells in chronic rheumatoid synovitis? Arthritis Rheum 33,768-773[Medline]
2. Burmester, G. R., Stuhlmüller, B., Keyszer, G., Kinne, R. W. (1997) Mononuclear phagocytes and rheumatoid synovitis Arthritis Rheum 40,5-18[Medline]
3. Hirohata, S., Yanagida, T., Itoh, K., Nakamura, H., Yoshino, S., Tomita, T., Ochi, T. (1996) Accelerated generation of CD14⁺ monocyte-lineage cells from the bone marrow of rheumatoid arthritis patients Arthritis Rheum 39,836-843[Medline]
4. Firestein, G. S. (1996) Invasive fibroblast-like synoviocytes in rheumatoid arthritis Arthritis Rheum 39,1781-1790[Medline]
5. van den Berg, D. J., Sharma, A. K., Bruno, E., Hoffman, R. (1998) Role of members of the wnt gene family in human hematopoiesis Blood 92,3189-3202[Abstract/Free Full Text]
6. Sen, M., Lauterbach, K., El-Gabalawy, H., Firestein, G. S., Corr, M., Carson, D. A. (2000) Expression and function of wingless and frizzled homologs in rheumatoid arthritis Proc. Natl. Acad. Sci. USA 97,2791-2796[Abstract/Free Full Text]
7. Zvaifler, N. J., Steinman, R. M., Kaplan, G., Lau, L. L., Rivelis, M. (1985) Identification of immunostimulatory dendritic cells in synovial effusions of patients with rheumatoid arthritis J. Clin. Invest 76,789-800
8. Thomas, R., Davis, L. S., Lipsky, P. E. (1994) Rheumatoid synovium is enriched in mature antigen-presenting dendritic cells J. Immunol 152,2613-2623[Abstract]
9. Hendler, P. L., Lavoie, P. E., Werb, Z., Chan, J., Seaman, W. E. (1985) Human synovial dendritic cells: direct observation of transition to fibroblasts J. Rheumatol 12,660-664[Medline]
10. Kyogoku, M., Sawai, T., Murakami, K., Ito, J. (1992) Histopathological characteristics of rheumatoid arthritis—as a clue to elucidate its pathogenesis Nippon Rinsho 50,483-489
11. Arnett, F. C., Edworthy, S. M., Bloch, D. A., McShane, D. J., Fries, J. F., Cooper, N. S., Healey, L. A., Kaplan, S. R., Liang, M. H., Luthra, H. S., Medsger, T. A., Jr, Mitchell, D. M., Neustadt, D. H., Pinals, R. S., Schaller, J. G., Sharp, J. T., Wilder, R. L., Hunder, G. G. (1988) The American Rheumatism Association 1987 revised criteria for the classification of rheumatoid arthritis Arthritis Rheum 31,315-324[Medline]
12. Ueda, T., Tsuji, K., Yoshio, H., Ebihara, Y., Yagasaki, H., Hisakawa, H., Mitsui, T., Manabe, A., Tanaka, R., Kobayashi, K., Ito, M., Yasukawa, K., Nakahata, T. (2000) Expansion of human NOD/SCID-repopulating cells by stem cell factor, Flk2/Flt3 ligand, thrombopoietin, IL-6, and soluble IL-6 receptor J. Clin. Invest 105,1013-1021[Medline]
13. Shinohara, S., Hirohata, S., Inoue, T., Ito, K. (1992) Phenotypic analysis of peripheral blood monocytes isolated from patients with rheumatoid arthritis J. Rheumatol 19,211-215[Medline]
14. Dechanet, J., Briolay, J., Rissoan, M.-C., Chomarat, P., Galizzi, J.-P., Banchereau, J., Miossec, P. (1993) IL-4 inhibits growth factor-stimulated rheumatoid synoviocyte proliferation by blocking the early phases of the cell cycle J. Immunol 151,4908-4917[Abstract]
15. Goto, M., Sasano, M., Yamanaka, H., Miyasaka, N., Kamatani, N., Inoue, K., Nishioka, K., Miyamoto, T. (1987) Spontaneous production of an interleukin-1-like factor by cloned rheumatoid synovial cells in long-term culture J. Clin. Invest 80,786-796
16. Lindhout, E., van Eijk, M., van Pel, M., Lindeman, J., Dinant, H. J., de Groot, C. (1999) Fibroblast-like synoviocytes from rheumatoid arthritis patients have intrinsic properties of follicular dendritic cells J. Immunol 162,5949-5956[Abstract/Free Full Text]
17. Bringuier, A. F., Seebold-Choqueux, C., Morlcard, Y., Simmons, D. J., Milhaud, G., Labat, M. L. (1992) T lymphocyte control of HLA-DR blood monocyte differentiation into neo-fibroblasts. Further evidence of pluripotential secreting functions of HLA-DR monocytes, involving not only collagen but also uromodulin, amyloid-beta peptide, alpha-fetoprotein and carcinoembryonic antigen Biomed. Phamacother 46,91-108[Medline]
18. Bucala, R., Spiegel, L. A., Chesney, J., Hogan, M., Cerami, A. (1994) Circulating fibrocytes define a new leukocyte subpopulation that mediates tissue repair Mol. Med 1,71-81[Medline]
19. Chesney, J., Metz, C., Stavitsky, A. B., Bacher, M., Bucala, R. (1998) Regulated production of type I collagen and inflammatory cytokines by peripheral blood fibrocytes J. Immunol 160,419-425[Abstract/Free Full Text]
20. Labat, M. L., Bringuier, A. F., Seebold, C., Morlcard, Y., Meyer-Mula, C., Laporte, P., Talmage, R. V., Grubb, S. A., Simmons, D. J., Milhaud, G. (1991) Monocytic origin of fibroblasts: spontaneous transformation of blood monocytes into neo-fibroblastic structures in osteomyelosclerosis and Engelmann’s disease Biomed. Pharmacother 45,289-299[Medline]
21. Labat, M. L., Bringuier, A. F., Arys-Philippart, C., Arys, A., Wellens, F. (1994) Monocytic origin of fibrosis: in vitro transformation of HLA-DR monocytes into neo-fibroblasts: inhibitory effect of all-trans-retinoic acid on this process Biomed. Pharmacother 48,103-111[Medline]
22. Petrakis, N. L., Davis, M., Lucia, S. P. (1961) The in vivo differentiation of human leukocytes into histiocytes, fibroblasts and fat cells in subcutaneous diffusion chambers Blood 17,109-118[Abstract/Free Full Text]
23. Feldmann, M., Brennan, F. M., Maini, R. N. (1996) Role of cytokines in rheumatoid arthritis Annu. Rev. Immunol 14,397-440[Medline]
24. Moreland, L. W., Heck, L. W., Jr, Koopman, W. J. (1997) Biologic agents for treating rheumatoid arthritis Arthritis Rheum 40,397-409[Medline]
25. Suzuki, Y., Nishikaku, F., Nakatuka, M., Koga, Y. (1998) Osteoclast-like cells in murine collagen induced arthritis J. Rheumatol 25,1154-1160[Medline]
26. Ferrero, E., Bondanza, A., Leone, B. E., Manici, S., Poggi, A., Zocchi, M. R. (1998) CD14⁺ CD34⁺ peripheral blood mononuclear cells migrate across endothelium and give rise to immunostimulatory dendritic cells J. Immunol 160,2675-2683[Abstract/Free Full Text]
27. Kiener, H. P., Hofbauer, R., Tohidast-Akrad, M., Walchshofer, S., Redlich, K., Bitzan, P., Kapiotis, S., Steiner, G., Smolen, J. S., Valent, P. (2000) Tumor necrosis factor- promotes the expression of stem cell factor in synovial fibroblasts and their capacity to induce mast cell chemotaxis Arthritis Rheum 43,164-174[Medline]
28. Ceponis, A., Konttinen, Y. T., Takagi, M., Xu, J.-W., Sorsa, T., Matucci-Cerinic, M., Santavirta, S., Bankl, H.-C., Valent, P. (1998) Expression of stem cell factor (SCF) and SCF receptor (c-kit) in synovial membrane in arthritis: correlation with synovial mast cell hyperplasia and inflammation J. Rheumatol 25,2304-2314[Medline]
29. Lowenthal, R. M., Cohen, M. L., Atkinson, K., Biggs, J. C. (1993) Apparent cure of rheumatoid arthritis by bone marrow transplantation J. Rheumatol 20,137-140[Medline]
30. Hamilton, J. A., Biggs, J. C., Atkinson, K., Brooks, P. M. (1995) Bone marrow transplantation in autoimmune disease Baillieres. Clin. Rheumatol 9,673-687[Medline]

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