Endothelial progenitor cells in active rheumatoid arthritis: effects of tumour necrosis factor and glucocorticoid therapy

Defective proliferative capacity and accelerated telomeric loss of hematopoietic progenitor cells in rheumatoid arthritis

“…Support for a reduction of the HPC pool in RA comes from studies describing reduced numbers of BM CD34ϩ cells and reduced recovery of CD34ϩ populations in RA patients undergoing BM transplantation (22,23). Finally, endothelial precursor cells are markedly reduced in RA patients, suggesting an age-inappropriate demise affecting several CD34ϩ subpopulations (19).…”

“…Within the CD34ϩ population of circulating HSCs, a subpopulation expresses the vascular endothelial growth factor receptor 2 (VEGFR-2) and likely represents endothelial precursor cells that give rise to new blood vessels (16,17). VEGFR-2ϩ CD34ϩ cells have been localized in synovial tissue from RA as well as osteoarthritis patients (18), and a decreased number of endothelial precursor cells has been found in RA patients (19), suggesting that circulating progenitor cells accumulate in and feed the inflammatory lesions. In contrast, RA CD34ϩ BM cells generate more endothelial cells, with a positive correlation between endothelial cell generation and microvessel density in synovitic tissue (20).…”

Endothelial progenitor cells: Are they displaying a function in autoimmune disorders?

“…Finally corticosteroids and tumor necrosis factor-alpha (TNF-␣) blockers were described to stimulate EPCs number and function and to restore defective vasculogenesis (Grisar et al, 2007;Ablin et al, 2006). Further details, however, on the effects of these agents, specifically on the function of late-outgrowth EPCs in long-term controlled studies, are needed, in order to evaluate the effect of this class of drugs on atherosclerotic process progression.…”

Endothelial Progenitor Cells: New Targets to Control Autoimmune Disorders

“…Several lines of evidence indicate that RA is associated with aberrant and severe vasculogenesis (i.e. the de novo formation of blood vessels) within the inflamed joints (Paleolog, 2009, Grisar et al, 2007, Grisar et al, 2005, Herbrig et al, 2006, Hirohata et al, 2004, Jodon de Villeroche et al, 2010, Ruger et al, 2004, Silverman et al, 2007. One of the first observations of vasculogenesis in RA was the discovery that the synovial fluids from patients with RA contained a low molecular weight vasculogenesis factor apparently identical to that derived from tumours (Brown et al, 1980).…”