Tartrate-resistant acid phosphatase

About: Tartrate-resistant acid phosphatase is a research topic. Over the lifetime, 1115 publications have been published within this topic receiving 45937 citations. The topic is also known as: HPAP & SPENCDI.

Identification of cell types responsible for bone resorption in rheumatoid arthritis and juvenile rheumatoid arthritis.

Abstract: Focal resorption of bone at the bone-pannus interface is common in rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA) and can result in significant morbidity. However, the specific cellular and hormonal mechanisms involved in this process are not well established. We examined tissue sections from areas of bone erosion in patients with RA and JRA. Multinucleated cells (MNCs) were present in resorption lacunae in areas of calcified cartilage and in subchondral bone immediately adjacent to calcified cartilage, as previously described. mRNA for the calcitonin receptor (CTR) was localized to these MNCs in bone resorption lacunae, a finding that definitively identifies these cells as osteoclasts. These MNCs were also positive for tartrate-resistant acid phosphatase (TRAP) mRNA and TRAP enzymatic activity. Occasional mononuclear cells on the bone surface were also CTR positive. Mononuclear cells and MNCs not on bone surfaces were CTR negative. The restriction of CTR-positive cells to the surface of mineralized tissues suggests that bone and/or calcified cartilage provide signals that are critical for the differentiation of hematopoietic osteoclast precursors to fully differentiated osteoclasts. Some MNCs and mononuclear cells off bone and within invading tissues were TRAP positive. These cells likely represent the precursors of the CTR-TRAP-positive cells on bone. Parathyroid hormone receptor mRNA was present in cells with the phenotypic appearance of osteoblasts, in close proximity to MNCs, and in occasional cells within pannus tissue, but not in the MNCs in bone resorption lacunae. These findings demonstrate that osteoclasts within the rheumatoid lesion do not express parathyroid hormone receptor. In conclusion, the resorbing cells in RA exhibit a definitive osteoclastic phenotype, suggesting that pharmacological agents that inhibit osteoclast recruitment or activity are rational targets for blocking focal bone erosion in patients with RA and JRA.

A combination of osteoclast differentiation factor and macrophage-colony stimulating factor is sufficient for both human and mouse osteoclast formation in vitro.

Abstract: Both human and murine osteoclasts can be derived in vitro from hematopoietic cells or monocytes that are cocultured with osteoblasts or marrow-derived stromal cells. The osteoclastogenic stimulus provided by murine osteoblasts and marrow-derived stromal cells is now known to be mediated by osteoclast differentiation factor (ODF), a membrane-bound tumor necrosis factor-related ligand. This study demonstrates that mouse spleen cells and monocytes form osteoclasts when cultured in the presence of macrophage-colony stimulating factor (M-CSF) and a soluble form of murine ODF (sODF). Numerous multinucleated osteoclasts expressing tartrate resistant acid phosphatase (TRAP) and calcitonin receptor (CTR) formed within 7 days of culture and engaged in extensive lacunar bone resorption. Osteoclast number and bone resorption area was dependent on sODF concentration. Long-term cultured human monocytes also formed bone resorbing osteoclasts in response to co-stimulation by sODF and M-CSF, although this required more th...

Tartrate-resistant acid phosphatase isoenzyme in the reticulum cells of leukemic reticuloendotheliosis.

Abstract: Acid phosphatase activity in the reticulum cells of leukemic reticuloendotheliosis is quantitatively and qualitatively different from that in the lymphosarcoma cells of lymphosarcoma and in lymphocytes of chronic lymphocytic leukemia. Enzyme activity in the reticulum cells is strong and tartrate resistant, whereas that in the lymphoid cells of the other two diseases is very weak and is inhibited by tartrate. A combined cytochemical and electrophoretic study indicates that this tartrate-resistant enzyme activity represents isoenzyme 5. It is present almost exclusively in the reticulum cells and not in other hemic cells in leukemic reticuloendotheliosis. It is not present in the lymphoid cells in lymphosarcoma or chronic lymphocytic leukemia. It may be used as the marker enzyme to diagnose leukemic reticuloendotheliosis and to trace the origin of the "reticulum cells" ("hairy cells") in the reticuloendothelial system.

Tartrate-resistant acid phosphatase 5b: a novel serum marker of bone resorption.

Abstract: Human serum contains two forms of tartrate-resistant acid phosphatase (TRAP), 5a and 5b. Of these, 5a contains sialic acid and 5b does not. We show here that antigenic properties and pH optimum of TRAP purified from human osteoclasts are identical to those of serum TRAP 5b and completely different from those of serum TRAP 5a, suggesting that 5b would be derived from osteoclasts and 5a from some other source. We developed a novel immunoassay specific for 5b using a monoclonal antibody O1A as capture antibody. O1A did not bind acid phosphatase derived from platelets and erythrocytes. Western analysis showed that O1A was specific for TRAP in both human bone and serum. We measured bound TRAP activity at pH 6.1, where 5b is highly active and 5a almost completely inactive. The immunoassay detected more than 90% of the initial TRAP 5b activity after 8-h incubation of serum samples at 25 degrees C and after 3 days incubation at 4 degrees C. Serum TRAP 5b activity decreased significantly after 6 months of hormone replacement therapy (HRT) of postmenopausal women compared with the change observed in postmenopausal women receiving placebo (p < 0.0001). Instead, no significant differences were observed between the changes in the placebo and HRT groups in total serum TRAP amount. These results show that serum TRAP 5b is a specific and sensitive marker for monitoring antiresorptive treatment. Instead, total serum TRAP cannot be used for that purpose. These findings may turn out to be a significant improvement in using serum TRAP as a resorption marker.