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.

Tartrate-resistant acid phosphate activity as osteoclastic marker: Sensitivity of cytochemical assessment and serum assay in comparison with standardized osteoclast histomorphometry

Abstract: Tartrate-resistant acid phosphatase (TRAP) activity is regarded as an important cytochemical marker of osteoclasts; its concentration in serum is utilized as a biochemical marker of osteoclast function and degree of bone resorption. This study was carried out to assess the sensitivity of TRAP activity both as a cytochemical marker in histological sections and as a biochemical marker in serum in comparison with the standardized histomorphometric variables of osteoclasts. To this end we investigated 24 patients (21 women, 3 men; 60 +/- 17 years of age) affected with various metabolic bone diseases. Osteoclast surface (OcS/BS) and osteoclast number (OcN/BS) were evaluated by standardized histomorphometry in iliac crest biopsies. On the basis of TRAP cytochemical activity, TRAP-positive osteoclast surface (TRAP + OcS/BS) and number (TRAP + OcN/BS) were measured. TRAP-positive cells adjacent to bone and showing one nucleus or no nuclei at all in the plane of section were included in the counts as osteoclasts. Serum TRAP activity was determined by spectrophotometric assay. Values of OcS/BS and OcN/BS were much lower than those of TRAP + OcS/BS (-50%) and TRAP + OcN/BS (-60%), respectively. Correlations between OcS/BS and TRAP + OcS/BS, and between OcN/BS and TRAP + OcN/BS, were highly significant. Serum TRAP was significantly correlated with OcS/BS, OcN/BS, and TRAP + OcN/BS. These correlations, however, were rather low. Moreover, serum TRAP did not correlate with TRAP + OcS/BS. From these results, the conclusion can be drawn that while TRAP activity is confirmed as a valid cytochemical marker for identification of osteoclasts, serum TRAP activity is an osteoclastic marker of weak sensitivity. This may be due to known factors, such as synthesis of the enzyme not being unique to osteoclasts, enzyme instability, and the presence of inhibitors in serum. Mononucleated osteoclasts do not significantly influence the serum enzyme levels.

Markers of bone turnover: biochemical and clinical perspectives.

Abstract: Bone remodelling is a process by which bone grows and turns over. This process involves a series of highly regulated steps that depend on the interaction of two cell lineages, the osteoclasts and the osteoblasts. Information on metabolic activity of bone tissue are achieved with the determination, in blood and in urine, of biochemical products derived from the activity of this cells. The ability to determine bone turnover with biochemical markers has been enhanced considerably in recent years with the development of new assays for more sensitive and specific markers. These new markers can now replace the outdated and non-specific markers of bone remodeling such as serum total alkaline phosphatase (ALP) and urinary hydroxyproline (Hyp) determination. Biochemical markers of bone turnover can be classified according to the process that underlie in markers of bone formation, products of the osteoblast activity [bone ALP, osteocalcin (OC), procollagene I C- and N-terminal propeptides] and markers of bone resorption, products of the osteocalst activity [pyridinuim crosslinks, collagen I C- and N-terminal telopeptides (CTX-I and NTX-I), tartrate resistent acid phosphatase (TRACP) isoform 5b]. The interpretation of laboratory results should always include the consideration of potential sources of variability. Variation in the results of biochemical markers of bone metabolism can compromise their ability to characterize disorders of bone metabolism. Variation can be categorized into pre-analytical, analytical and biological sources. However, the determination of biochemical markers of bone turnover offers many advantages in clinical practice, since they are non-invasive, can be repeated often, and major changes occur in a short time.

Expression of the calcitonin receptor in bone marrow cell cultures and in bone: a specific marker of the differentiated osteoclast that is regulated by calcitonin

Abstract: We studied the temporal sequence of osteoclast (OC) differentiation from precursor cells in murine marrow cultures. Two markers of the OC phenotype, calcitonin (CT) receptor (CTR) and tartrate resistant acid phosphatase (TRAP), were assessed. Marrow cells from C57BL/6 mice were cultured for 3, 5, 7, and 9 days with or without 1,25-(OH)2vitamin D3 (10(-8) M). In controls only small numbers of osteoclastic multinucleated cells 9MNCs) formed per well ( 80 per well on day 7). Messenger RNA (mRNA) for TRAP was detectable by reverse transcription-polymerase chain reaction amplification in both control and 1,25-(OH)2D3 treated groups at all times. However, TRAP mRNA was detectable in MNCs by the less sensitive in situ hybridization only on days 5, 7, and 9 and only in 1,25-(OH)2D3 treated cells. In control cultures, CTR mRNA was present on day 3 only in nonadherent cells and was not present in adherent cells (where MNCs formed) at any ...

Generation of osteoclastic function in mouse bone marrow cultures: multinuclearity and tartrate-resistant acid phosphatase are unreliable markers for osteoclastic differentiation.

Abstract: The osteoclast is the cell that resorbs bone. It is known to derive from hemopoietic precursors, and a series of recent experiments has used enumeration of the tartrate-resistant acid phosphatase (TRAP)-positive multinucleate cells that develop in cultures of hemopoietic tissue as a means to analyze the regulation of osteoclast generation. These multinucleate cells have never been definitively characterized as osteoclasts, however, and we elected to assess the relationship among bone resorption (the primary function of the osteoclast), TRAP, and multinuclearity in mouse bone marrow cultures. Mouse bone marrow cells and peritoneal macrophages were incubated on plastic coverslips or bone slices for up to 14 days in the presence or absence of 1 alpha, 25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3]. Osteoclast generation, as judged by bone resorption, occurred in marrow cell cultures only in the presence of 1 alpha,25-(OH)2D3. However, TRAP-positive multinuclear cells developed both with and without the hormone. The multinuclear cells bound F4/80, a marker for macrophages that does not bind to osteoclasts. Peritoneal macrophages became multinucleate and developed TRAP positivity in culture to levels similar to those in freshly isolated osteoclasts, especially with 1 alpha,25-(OH)2D3, but remained nonresorptive. In cultures of marrow cells incubated with 1 alpha,25-(OH)2D3 bone resorption was more extensive than could readily be accounted for by the number of multinucleate cells present, and the size of excavations and extent of resorption suggested a major contribution by mononuclear cells with osteoclastic function. Thus, while TRAP and multinuclearity are reliable markers for osteoclastic phenotype in bone, they are unreliable markers in culture. Experiments designed to evaluate the regulation of osteoclast generation through enumeration of TRAP-positive multinucleate cells formed in bone marrow cultures will not only overstate, to an unknown and probably variable degree, the number of multinucleate osteoclasts that develop, but will also fail to even identify what may be a considerable and more substantial population of mononuclear cells that possess osteoclastic characteristics.