|
|||||||||
|
|
|
|
|
|
|
|
|
|
|
Prepublished online as a Blood First Edition Paper on May 13, 2002; DOI 10.1182/blood-2002-02-0390.
HEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY
From the Departments of Pediatrics and
Immunology/Microbiology, Rush Children's Hospital and Rush University,
Chicago, IL.
Hemophilia is a rare congenital bleeding disorder that is due to
the deficiency of blood coagulation factor VIII or IX. Recurrent musculoskeletal bleeding is common and bleeding into joints results in
a chronic inflammatory condition termed hemophilic synovitis. This
destructive process is characterized by hemosiderin deposition in the
superficial and deeper layers of the synovial membrane as well as a
proliferation of synovial fibroblasts and vascular cells. The
hyperplastic synovium and neovascular changes are reminiscent of the
histopathologic appearance observed in malignant tissues. Indeed, the
benign hyperplastic synovium in patients with hemophilia displays
similar invasive and destructive behaviors suggesting the possibility
of analogous disturbances in growth control and locally invasive
mechanisms. Iron plays a role in malignant cell growth, local invasion,
and tumor progression, possibly due to changes in the expression of the
proto-oncogene, c-myc. We hypothesized that iron
plays a similar role in hemophilic synovitis. To explore this
hypothesis, we investigated the in vitro effects of iron on the
proliferation of a primary, human synovial fibroblast cell (HSFC) line
and the involvement of c-myc in this process. We also examined the role of ceramide, a sphingolipid capable of inducing apoptosis in this model system. HSFC proliferation was increased in a
dose-dependent fashion and c-myc expression was enhanced by
ferric citrate compared to sodium citrate control. Ceramide prevented
both the iron-induced increases in HSFC proliferation and
c-myc expression. These results indicate that iron probably plays a role in the proliferative changes observed in hemophilic joint
disease and that aberrant expression of c-myc may underlie the iron effects. Furthermore, these results suggest that there may be
a therapeutic role for ceramide in reversing these changes.
(Blood. 2002;100:912-916) Recurrent musculoskeletal bleeding is the most
frequent manifestation of severe hemophilia. Bleeding into a joint
results in a complex arthritis known as "hemophilic arthropathy"
that in time evolves into a chronic, persistent inflammatory disorder termed "hemophilic synovitis." It has been speculated that the persistent presence of blood in the joint space is involved in the
pathogenesis of this disorder.1 Iron deposition in
synovial tissues is one of the hallmarks of hemophilic
arthropathy.2-4 In vitro, DNA synthesis by synovial
fibroblast cells exposed to ferric citrate at concentrations up to 1 mM
for 72 hours is increased compared to cells cultured with sodium
citrate.5 Iron, in combination with interleukin-1 The proto-oncogene c-myc plays a pivotal role in cell growth
control, differentiation, and apoptosis.6,7 Aberrant
expression of this oncogene is a feature of many human and experimental
neoplasms.8,9 Hyperplastic synovium has a histopathologic
appearance similar to malignant tissue and displays the same invasive
and destructive behavior, thought to underlie the pathologic process
observed in hemophilic joints10 as well as rheumatoid
joints.11,12 In rheumatoid, reactive, and bacterial
arthritis, oncogene expression, including c-myc expression
has been related to both the extent of synovial hypercellularity and
the intensity of the mononuclear cell infiltration.13 In
hemophilic joint disease, one of the earliest pathologic changes
observed following joint hemorrhage is villous hypertrophy and an
increase in the vascularity of synovial tissue. Villous hypertrophy may
be the result of dysregulated cell growth or abrogation of cell death
or both. As in malignant cells, aberrant expression of one or more
proto-oncogenes may underlie these changes. We examined the hypothesis
that iron increases the proliferation of human synovial fibroblast
cells by inducing aberrant expression of c-myc
proto-oncogene, and that reversal of this process by ceramide leads to
synovial cell apoptosis. These data are the first description of an
association between iron and c-myc playing a role in human
synovial cell proliferation.
Cells and culture
Iron salts and ceramide
Cell proliferation assay Cells (2 × 103) were placed into each well of a flat-bottom 96-well plate (Falcon 3072) and incubated for 9 days. Cell number was determined on days 1, 3, 5, 7, and 9 using the CellTiter 96 Aqueous nonradioactive cell proliferation assay kit according to the manufacturer's instructions (Promega, Madison, WI). A solution of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium and phenazine methosulfate (MTS/PMS; 20 µL) was added to each well and incubated for 3 hours at 37°C in a humidified 5% CO2 atmosphere; then absorbance at 450 nm was determined using an enzyme-linked immunosorbent assay (ELISA) plate reader (Ceres UV 900 H D; Biotek Instruments, Winooski, VT). Quadruplicate wells were used for all proliferation experiments.Preparation of RNA, complementary DNA, and polymerase chain reaction amplification of complementary DNA Total cellular RNA was extracted from cultured cell lines using RNAzol (Cinna/Biotecx Laboratories International, Friendswood, TX), according to the manufacturer's instructions. For polymerase chain reaction (PCR) analysis, complementary DNA (cDNA) was made by reverse transcription (RT) of each RNA sample, using the Universal RiboClone cDNA synthesis system (Promega). PCR reactions were performed with 5 µL of each cDNA, 20 µM of each sense and antisense primers, and 1.25 U Taq polymerase (Fisher Biotech, Pittsburgh, PA). Thirty-two cycles of denaturation, annealing, and extension (94°C for 50 seconds, 60°C for 45 seconds, and 72°C for 45 seconds, respectively) were performed on a GeneAmp PCR System 2400 thermal cycler (Perkin-Elmer, Branchburg, NJ). The primers used were as follows: (1) human c-myc sense: 5'-TCGCAAGACTCCAGCGCCTTCTCTC-3', (2) human c-myc antisense 5'-TGACACTGTCCAACTTGACCCTCTT-3', (3) human -actin sense
5'-GGGTCAGAAGGATTCCTATC-3', and (4) human -actin antisense
5'-TCTCAAACATGATCTGGGTC-3'. The amplified samples were resolved on
1.5% agarose gels and photographed.
Fluorescent microscopic apoptosis assay The ApoAlert DNA fragmentation assay kit (Clontech, Palo Alto, CA) was used to detect apoptosis. HSFCs were isolated following exposure to cell dissociation solution, washed with phosphate-buffered saline (PBS), and resuspended in PBS at 2 × 107 cells/mL. The cell suspension (50 µL) was transferred onto a slide coated with poly-L-lysine and fixed with 4% paraformaldehyde in PBS. The cells were permeablized with 0.2% Triton X-100 in PBS, incubated with terminal deoxynucleotidyl transferase and stained with propidium iodide (PI). The slides were photographed using fluorescence microscopy with a dual-pass fluorescein isothiocyanate/PI filter set through which apoptotic cells appear yellow.
Ferric citrate increases proliferation of synovial cells Because iron is known to increase DNA synthesis,5 we asked if HSFC proliferation would be affected by iron in vitro. HSFCs used in these experiments proliferate slowly with a mean doubling time of approximately 5 days. The proliferation of HSFCs was significantly increased in the presence of iron compared to controls (Figure 1). Exposure to 0.1 or 1 mM ferric citrate for 9 days resulted in a 2-fold increase in cell proliferation compared to control HSFCs: 0.17 ± 0.03 or 0.19 ± 0.01 versus 0.09 ± 0.01, respectively. The increase in cell number was evident after 6 days in the presence of iron citrate. Culturing HSFCs with sodium citrate had no effect on cell proliferation compared with control cells (data not shown). The lowest concentration of ferric citrate tested (0.01 mM) had no effect on cell proliferation over 9 days of observation, similar to sodium citrate and control cells. Maximal stimulation of HSFC proliferation was observed at 1 mM ferric citrate and, therefore, this concentration was used in subsequent experiments.
Effect of C2-ceramide on synovial cell proliferation Ceramide affects a number of cellular processes including cell differentiation, apoptosis, and proliferation. Because ceramide inhibits the proliferation of several cell types,15,16 we asked whether synovial cell proliferation would also be inhibited. To assess the effects of ceramide on HSFC growth, cells were cultured for 9 days with a membrane-permeable ceramide analogue, C2-ceramide, at concentrations up to 50 µM. Cell proliferation was inhibited in a concentration-dependent manner (Figure 2). At 50 µM, C2-ceramide completely abrogated cell proliferation and by 9 days a decrease in cell number was observed (Figure 2). Concentrations of C2-ceramide less than 25 µM did not have a significant effect on HSFC proliferation until the duration of exposure reached 1 week (OD450 0.068 versus 0.1, C2-ceramide versus control, respectively; Figure 2).
Effects of C2-ceramide on iron-stimulated synovial cell proliferation To test effects of C2-ceramide on HSFC proliferation stimulated by iron, cells were precultured with 1 mM ferric citrate for 7 days then harvested and seeded in 96-well plates in the presence of 1 mM ferric citrate with or without C2-ceramide. The rate of cell proliferation was determined over an additional 9 days. C2-ceramide at a concentration of 25 or 50 µM significantly inhibited iron-induced synovial cell proliferation (Figure 3).
Expression of c-myc is induced by iron and abrogated by ceramide Because iron increases HSFC proliferation (Figure 1) and c-myc has been related to synovial hypercellularity in other forms of arthritis,13 we speculated that iron may increase HSFC proliferation by inducing aberrant expression of c-myc. Using reverse transcription-PCR, cells cultured with 1 mM ferric citrate demonstrated prominent c-myc expression (Figure 4, lane 2) compared to cells exposed to 1 mM sodium citrate (lane 3) or control cells (lane 4) grown in standard medium without salt supplementation. The increase in c-myc expression induced by iron (Figure 5, lane 3) was abrogated by exposure of the cells to 25 µM C2-ceramide (lane 2).
Cell morphology and apoptosis Cell morphology was unaffected by ferric citrate (Figure 6B) or sodium citrate (data not shown) at the concentrations and exposure durations used in these experiments. Cells exposed to 25 µM C2-ceramide for 24 hours (Figure 6C) retracted their processes and the cell body appeared rounded regardless of whether they were precultured with iron or sodium salt. More prolonged exposure to concentrations of C2-ceramide at or below 25 µM did not further alter cell morphology. To determine if the growth inhibition and morphologic changes observed following exposure of HSFC to C2-ceramide were due to apoptosis, we examined cells with a DNA fragmentation assay. HSFCs precultured with iron (or sodium citrate) then exposed to 25 µM (not shown) or 50 µM of C2-ceramide (Figure 7B) for 24 hours exhibited strong nuclear fluorescence indicative of apoptosis. In the absence of C2-ceramide, none of the iron-stimulated cells demonstrated DNA fragmentation (Figure 7A).
Bleeding into a joint produces an acute, transient inflammatory reaction known as hemophilic synovitis. With repeated episodes of bleeding, synovial fibroblasts hypertrophy and proliferate. This proliferative response is accompanied by an intense neovascularization of the synovial membrane.17 These early pathologic features have been described in dogs with spontaneous hemophilia, and changes similar to hemophilic arthritis have been produced in experimental animals following injection of autologous blood.18,19 The component of blood that initiates and perpetuates this proliferative and inflammatory reaction is not known. The hallmark of hemophilic synovitis is deposition of iron in superficial and subsynovial layers of the joint. Morris et al2 studied 5 hemophilic synovial membranes by light microscopy and found that all cases contained intracellular and extracellular granular deposits of iron in the most superficial cells. In the deeper synovial layers there were numerous pleomorphic ovate bodies. Using a computerized electron-probe and x-ray microanalytical techniques, these investigators demonstrated the granular material to be highly iron-saturated ferritin and the ovate bodies to be almost pure iron. Iron participates in a wide range of biochemical reactions that are necessary for cell viability and proliferation. Iron is essential for DNA synthesis.20 Clinical correlations link cellular iron content to the development and progression of human cancer. Iron is necessary for proliferation of cell lines derived from solid tumors21 and is essential for the clonal expansion of the malignant phenotype in neoplastic cells of all origins.20 In vitro, iron increases DNA synthesis in cultured synovial fibroblasts.5 These data led us to speculate that iron may be an important component in the synovitis that follows recurrent joint bleeding in hemophilia. In the present study, we show that iron, in the form of ferric citrate at a concentration more than 0.1 mM, significantly increases HSFC proliferation. We also show that iron increases c-myc expression and C2-ceramide abrogates the increase in cell proliferation and reduces the c-myc expression induced by iron. Furthermore, C2-ceramide induces apoptosis of HSFCs. These results indicate that iron plays a critical role in synovial fibroblast proliferation and that ceramide may represent a novel therapeutic agent to treat iron-induced synovial hypertrophy. Similarities between hemophilic synovitis and rheumatoid arthritis are well documented. In both it has been suggested that iron mediates the inflammatory and proliferative responses as well as the tissue damage.18,22,23 In both processes, microbleeding is well described and iron deposition correlates closely with the extent of erosive disease and is associated with a poor prognosis.23,24 Aberrantly activated gene sequences, proto-oncogenes, have been suggested to play a role in the invasive behavior of rheumatoid synovial fibroblasts.12 Increased expression of oncogenes and their gene products have been detected in human synovial tissues from patients with rheumatoid arthritis.25 The proto-oncogene c-myc plays a pivotal role in growth control, differentiation, and apoptosis,6,7 and its abnormal expression has been associated with many naturally occurring neoplasms.8,9 Expression of c-myc in human synovial tissue was significantly correlated both to the degree of synovial hypercellularity and the synovial lymphocytic infiltration in rheumatoid, reactive, bacterial, and osteoarthritis.13 Interestingly, c-myc antisense oligonucleotides induce apoptosis and down-regulate fas expression in rheumatoid synovial cells.26 Here we show that iron increases c-myc expression in HSFCs. Kyriakou et al27 showed that desferrioxamine (DFX), an iron chelating agent, decreased expression of c-myc in peripheral blood mononuclear cells from patients with thalassemia. A rapid decrease in c-myc messenger RNA and protein levels followed by apoptosis and inhibition of DNA synthesis followed exposure of HL-60 or K562 leukemic cells to DFX.28 These effects were blocked by simultaneous addition of ferric chloride. These studies support our data suggesting that iron-stimulated synovial cell proliferation is associated with up-regulation of c-myc. Furthermore, c-myc was shown to suppress expression of H-ferritin, an iron-binding protein, and up-regulate iron regulatory protein-2 with a net effect of increasing the intracellular iron pool.29 The result of increased cellular iron is increased activity of ribonucleotide reductase, the rate-limiting enzyme in DNA synthesis.30 Ceramide is a recently identified intracellular messenger, which is generated in the sphingomyelin cycle in response to various stimuli. It regulates a variety of cellular processes such as cell differentiation, induction of apoptosis, and inhibition of cell growth.13,14 The addition of a cell-permeable ceramide to the culture medium increases the intracellular ceramide concentration of the cells and mimics the activation of cellular sphingomyelinases.31 Ceramide has been shown to induce apoptosis of rheumatoid arthritis synovial cells.32 In the present study, we show that C2-ceramide induces a dose-dependent inhibition of normal or iron-stimulated HSFC proliferation. Iron-stimulated c-myc expression by HSFCs is abrogated by ceramide, which also induces the morphologic changes characteristic of apoptosis and results in DNA fragmentation (Figure 6). Development of therapeutic strategies designed to inhibit synovial fibroblast cell proliferation or induce apoptosis may be useful to treat hemophilic joint disease thereby avoiding surgical or radioactive interventions.
The authors wish to thank Samuel P. Gotoff, MD, for his support of this research project and his thoughtful review of the manuscript; Martha Cook for her scientific contributions and editorial assistance in the preparation of the manuscript. Finally, the authors wish to thank all of the patients with hemophilia who engendered enthusiasm for these investigations.
Submitted February 8, 2002; accepted March 28, 2002.
Prepublished online as Blood First Edition Paper, May 13, 2002; DOI 10.1182/blood-2002-02-0390.
Supported by the Women's Board Pediatric Oncology Research Fund. This work has been presented in abstract form at the 1999 Annual Meeting of the National Hemophilia Foundation and at the 2001 Annual Meeting of the American Society of Hematology.
The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734.
Reprints: Leonard A. Valentino, Rush Children's Hospital, 1653 W Congress Pkwy, Chicago, IL 60612; e-mail: lvalentino{at}rush.edu.
1.
Hoaglund FT.
Experimental hemarthrosis. The response of canine knees to injections of autologous blood.
J Bone Joint Surg Am.
1967;49:285-298 2. Morris CJ, Wainwright AC, Steven MM, Blake DR. The nature of iron deposits in haemophilic synovitis. An immunohistochemical, ultrastructural and X-ray microanalytical study. Virchows Arch A Pathol Anat Histopathol. 1984;404:75-85[CrossRef][Medline] [Order article via Infotrieve]. 3. Stein H, Duthie RB. The pathogenesis of chronic haemophilic arthropathy. J Bone Joint Surg Br. 1981;4:601-609. 4. Roosendaal G, Vianen ME, Wenting MJ, et al. Iron deposits and catabolic properties of synovial tissue from patients with haemophilia. J Bone Joint Surg Br. 1998;80:540-545[Medline] [Order article via Infotrieve]. 5. Nishiya K. Stimulation of human synovial cell DNA synthesis by iron. J Rheumatol. 1994;21:1802-1807[Medline] [Order article via Infotrieve]. 6. Aizawa T, Kokubun S, Kawamata T, Tanaka Y, Roach HI. c-Myc protein in the rabbit growth plate. Changes in immunolocalisation with age and possible roles from proliferation to apoptosis. J Bone Joint Surg Br. 1999;81:921-925[Medline] [Order article via Infotrieve]. 7. Landay M, Oster SK, Khosravi F, et al. Promotion of growth and apoptosis in c-myc nullizygous fibroblasts by other members of the myc oncoprotein family. Cell Death Differ. 2000;7:697-705[CrossRef][Medline] [Order article via Infotrieve]. 8. Askew DS, Ashmun RA, Simmons BC, Cleveland JL. Constitutive c-myc expression in an IL-3-dependent myeloid cell line suppresses cell cycle arrest and accelerates apoptosis. Oncogene. 1991;6:1915-1922[Medline] [Order article via Infotrieve]. 9. Evan GI, Wyllie AH, Gilbert CS, et al. Induction of apoptosis in fibroblasts by c-myc protein. Cell. 1992;69:119-128[CrossRef][Medline] [Order article via Infotrieve]. 10. Swanton MC. Hemophilic arthropathy in dogs. Lab Invest. 1959;8:1269-1277[Medline] [Order article via Infotrieve]. 11. Harris ED Jr. Recent insights into the pathogenesis of the proliferative lesion in rheumatoid arthritis. Arthritis Rheum. 1976;19:68-72[Medline] [Order article via Infotrieve]. 12. Hamilton JA. Hypothesis: in vitro evidence for the invasive and tumor-like properties of the rheumatoid pannus. J Rheumatol. 1983;10:845-851[Medline] [Order article via Infotrieve].
13.
Roivainen A, Soderstrom KO, Pirila L, et al.
Oncoprotein expression in human synovial tissue: an immunohistochemical study of different types of arthritis.
Br J Rheumatol.
1996;35:933-942 14. Nishiya K, de Sousa M, Tsoi E, Bognacki JJ, de Harven E. Regulation of expression of a human lymphoid cell surface marker by iron. Cell Immunol. 1980;53:71-83[CrossRef][Medline] [Order article via Infotrieve].
15.
Okazaki T, Bielawska A, Bell RM, Hannun YA.
Role of ceramide as a lipid mediator of 1 alpha,25-dihydroxyvitamin D3-induced HL-60 cell differentiation.
J Biol Chem.
1990;265:15823-15831
16.
Obeid LM, Linardic CM, Karolak LA, Hannun YA.
Programmed cell death induced by ceramide.
Science.
1993;259:1769-1771
17.
Madhok R, York J, Sturrock RD.
Haemophilic arthritis.
Ann Rheum Dis.
1991;50:588-591 18. Madhok R, Bennett D, Sturrock RD, Forbes CD. Mechanisms of joint damage in an experimental model of hemophilic arthritis. Arthritis Rheum. 1988;31:1148-1155[Medline] [Order article via Infotrieve]. 19. Convery FR, Woo SL, Akeson WH, Amiel D, Malcom LL. Experimental hemarthrosis in the knee of the mature canine. Arthritis Rheum. 1976;19:59-67[Medline] [Order article via Infotrieve]. 20. Sussman HH. Iron in cancer. Pathobiology. 1992;60:2-9[CrossRef][Medline] [Order article via Infotrieve].
21.
Rizzino A, Sato G.
Growth of embryonal carcinoma cells in serum-free medium.
Proc Natl Acad Sci U S A.
1978;75:1844-1848 22. Blake DR, Hall ND, Bacon PA, Dieppe PA, Halliwell B, Gutteridge JM. The importance of iron in rheumatoid disease. Lancet. 1981;2:1142-1144[Medline] [Order article via Infotrieve]. 23. Blake DR, Gallagher PJ, Potter AR, Bell MJ, Bacon PA. The effect of synovial iron on the progression of rheumatoid disease. A histologic assessment of patients with early rheumatoid synovitis. Arthritis Rheum. 1984;27:495-501[Medline] [Order article via Infotrieve]. 24. Bennett RM, Williams ED, Lewis SM, Holt PJ. Synovial iron deposition in rheumatoid arthritis. Arthritis Rheum. 1973;16:298-304[Medline] [Order article via Infotrieve]. 25. Muller-Ladner U, Kriegsmann J, Gay RE, Gay S. Oncogenes in rheumatoid arthritis. Rheum Dis Clin North Am. 1995;21:675-690[Medline] [Order article via Infotrieve]. 26. Hashiramoto A, Sano H, Maekawa T, et al. C-myc antisense oligodeoxynucleotides can induce apoptosis and down- regulate Fas expression in rheumatoid synoviocytes. Arthritis Rheum. 1999;42:954-962[CrossRef][Medline] [Order article via Infotrieve]. 27. Kyriakou D, Eliopoulos AG, Papadakis A, Alexandrakis M, Eliopoulos GD. Decreased expression of c-myc oncoprotein by peripheral blood mononuclear cells in thalassaemia patients receiving desferrioxamine. Eur J Haematol. 1998;60:21-27[Medline] [Order article via Infotrieve]. 28. Tomoyasu S, Fukuchi K, Yajima K, et al. Suppression of HL-60 cell proliferation by deferoxamine: changes in c-myc expression. Anticancer Res. 1993;13:407-410[Medline] [Order article via Infotrieve].
29.
Wu KJ, Polack A, Dalla-Favera R.
Coordinated regulation of iron-controlling genes, H-ferritin and IRP2, by c-MYC.
Science.
1999;283:676-679 30. Thelander L, Reichard P. Reduction of ribonucleotides. Annu Rev Biochem. 1979;48:133-158[CrossRef][Medline] [Order article via Infotrieve].
31.
Bielawska A, Crane HM, Liotta D, Obeid LM, Hannun YA.
Selectivity of ceramide-mediated biology. Lack of activity of erythro-dihydroceramide.
J Biol Chem.
1993;268:26226-26232 32. Ichinose Y, Eguchi K, Migita K, et al. Apoptosis induction in synovial fibroblasts by ceramide: in vitro and in vivo effects. J Lab Clin Med. 1998;131:410-416[CrossRef][Medline] [Order article via Infotrieve].
© 2002 by The American Society of Hematology.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
 |
|
  G. Roosendaal and F. Lafeber Prophylactic Treatment for Prevention of Joint Disease in Hemophilia -- Cost versus Benefit N. Engl. J. Med., August 9, 2007; 357(6): 603 - 605. [Full Text] [PDF]
|
|
|
|
 |
|
 R. McClain, N. Hakobyan, and L. A. Valentino Vascularization of the Synovial Membrane in Hemophilic Synovitis. Blood (ASH Annual Meeting Abstracts), November 16, 2006; 108(11): 4018 - 4018. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Hoffman, A. Harger, A. Lenkowski, U. Hedner, H. R. Roberts, and D. M. Monroe Cutaneous wound healing is impaired in hemophilia B Blood, November 1, 2006; 108(9): 3053 - 3060. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Cruz, G. Porto, S. Morais, M. Campos, and M. de Sousa HFE mutations in the pathobiology of hemophilic arthropathy Blood, April 15, 2005; 105(8): 3381 - 3382. [Full Text] [PDF]
|
|
|
|
|
|
L. A. Valentino, N. Hakobyan, T. Kazarian, A. A. Jabbar, and K. J. Jabbar Pathobiology of Hemophilic Synovitis II: Synovial Cell Proliferation. Blood (ASH Annual Meeting Abstracts), November 16, 2004; 104(11): 3077 - 3077. [Abstract] [Full Text]
|
|
|
|
|
|
T. Abshire Are oncogenes responsible for hemophilic arthropathy? Blood, October 1, 2004; 104(7): 1911 - 1912. [Full Text] [PDF]
|
|
|
|
|
|
N. Hakobyan, T. Kazarian, A. A. Jabbar, K. J. Jabbar, and L. A. Valentino Pathobiology of hemophilic synovitis I: overexpression of mdm2 oncogene Blood, October 1, 2004; 104(7): 2060 - 2064. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||
Top
Abstract
Introduction
(TNF-
(IFN-
