Showing papers on "Tartrate-resistant acid phosphatase published in 1992"

Phorbol ester induced osteoclast-like differentiation of a novel human leukemic cell line (FLG 29.1).

Abstract: Studies on human osteoclast formation have been hampered by lack of a defined isolated progenitor cell population. We describe here the establishment of a human leukemic cell line (designated FLG 29.1) from bone marrow of a patient with acute monoblastic leukemia. The cultured cells are predominantly undifferentiated leukemic blasts, but addition of 12-o-tetradecanoylphorbol 13-acetate (TPA; 0.1 microM) induces irreversible differentiation into adherent, non-dividing, multinucleated cells. TPA-treated cells bear surface antigens typical of fetal osteoclasts, degrade 45Ca-labeled devitalized bone particles, display tartrate-resistant acid phosphatase in both mononuclear and multinuclear cells and receptors for calcitonin. Calcitonin increases intracellular cAMP accumulation in TPA-treated cells. TPA-treated cells show some ultrastructural features of osteoclasts as evidenced by transmission EM. These results indicate that FLG 29.1 cells may represent an osteoclast committed cell population, which upon induction with TPA acquire some morphological, phenotypical, and functional features of differentiated osteoclasts.

Increased osteoclast activity is associated with aggressiveness of osteosarcoma.

Abstract: Osteosarcoma (OS) is a highly malignant primary skeletal tumor with a striking tendency to rapidly destroy the surrounding bone and metastasize, since metastases are frequently present at clinical onset The basis for the aggressiveness of this tumor is largely unknown However, recent studies in in vivo models indicate that the anti-osteolytic drugs, bisphosphonates, can inhibit the tumor local expansion and the formation of metastases We further investigated the association between the presence of active osteoclasts and the aggressiveness of OS We evaluated the presence of osteoclasts and the mRNA of different osteoclast-related genes in tumor biopsies from 16 OS patients and in three OS cell lines and the serum levels of bone resorption markers in the same series and in 28 other patients Tumor-associated osteoclasts were found in 63 and 75% of cases by histological and mRNA analysis Among different serum markers, only MMP-9 was significantly higher in OS cases (p=00001), whereas TRACP 5b was significantly higher in metastatic patients compared to nonmetastatic patients (p=00509) Serum TRACP 5b was significantly correlated to serum NTX (p<00001) and cathepsin K mRNA in tumor tissues (p=00153) In 8 patients we also analyzed TRACP 5b serum level at follow-up and we verified a significant decrease of TRACP 5b after primary tumor removal (p=00117) In conclusion, tumor-infiltrating osteoclasts are frequently found in OS and increased serum TRACP 5b levels and the presence of active osteoclast at primary sites were positively associated with tumor aggressiveness

Protein-tyrosine phosphatase activity of hairy cell tartrate-resistant acid phosphatase.

Abstract: Tartrate-resistant acid phosphatase (TRAcP) is a reliable cytochemical marker for the diagnosis of hairy cell leukemia (HCL). The enzyme has been the subject of much biochemical investigation yet its function in the hairy cells (HC) is still unknown. Two TRAcPs have been purified from HCL spleen tissues by a series of chromatographic separations. The two enzymes, provisionally called peak 1 and peak 2, had specific activities of greater than 600 U/mg and 800 U/mg respectively when p-nitrophenyl phosphate (p-NPP) was used as substrate and had Km values in the range of 1 to 5 mM p-NPP. The two TRAcPs had the same substrate specificities and inhibitor sensitivities, therefore could be isoforms of the same enzyme. Their pH optima were between 5 and 6 for all substrates tested including the phosphotyrosine-containing peptide, Raytide, which was still hydrolyzed efficiently at neutral pH. Neither phosphoserine nor phosphoserine-containing casein were hydrolyzed by either enzyme. The TRAcPs of HC may thus be capable of functioning as protein-tyrosine phosphatases (PTP). High activity of a PTP could regulate the activities of protein-tyrosine kinases and thereby influence the growth and differentiation of the hairy cells.

Differential effects of glucocorticoid on recruitment and activity of osteoclasts induced by normal and osteocalcin-deficient bone implanted in rats.

Abstract: Prolonged glucocorticoid excess is associated with bone loss. Among the contributory factors are glucocorticoids' suppression of bone formation and stimulation of bone resorption. In this study, the effects of glucocorticoids on bone resorption were evaluated in a rodent model. Subcutaneous implants of devitalized mineralized bone particles (BPs) elicit the recruitment of progenitor cells and their differentiation to osteoclasts which resorb the BPs. The effects of glucocorticoids on both the recruitment and the activity of cells induced by normal BPs were distinguished based upon when treatment was initiated. When treatment with hydrocortisone or dexamethasone was initiated at the time of BP implantation, the recruitment of bone-resorbing cells was impaired and a subsequent decrease in BP resorption was found. On the other hand, when treatment was initiated on day 7, glucocorticoids increased osteoclastic resorption and tartrate-resistant acid phosphatase activity. We also tested hydrocortisone's effect ...

Human tumour-associated macrophages are capable of bone resorption.

Abstract: Cellular mechanisms of bone resorption associated with skeletal metastasis are poorly understood. Human tumour-associated macrophages (TAMs) isolated from primary lung carcinomas were incubated on bone slices where they formed resorption lacunae after 14 days co-culture with a mouse marrow-derived stromal cell line (ST2) with added 1 alpha, 25-dihydroxy Vitamin D3 and dexamethasone. These co-cultures were associated with the formation of increased numbers of tartrate resistant acid phosphatase positive mononuclear and multinucleated cells. Similar cocultures of ST2 cells with normal alveolar macrophages did not result in lacunar resorption. Both in the presence and absence of ST2 cells, TAMs and normal alveolar macrophages produced roughening of the bone surface with exposure of mineralised collagen fibres. TAMs are capable of both low-grade surface resorption and high-grade lacunar resorption of bone, and a specific interaction with stromal cells is necessary for the latter to occur. TAMs may thus directly contribute to the bone resorption associated with skeletal metastasis.

Histochemical and fine structural study of bone of ipriflavone-treated rats.

Abstract: Bone labeling, histochemical, and fine structural studies were performed in order to clarify the effects of ipriflavone (IP) on rat bone tissue in vivo and in vitro. Labeling experiments showed a slight increase in bone formation during 3 days' administration. It was also noted that many osteoclasts detached from the bone surface at 1, 2, and 6 hours after administration in vivo. In addition, irregular localization of tartrate-resistant acid phosphatase (TRACPase) activity was observed in osteoclasts. Fine structurally, IP-treated osteoclasts exhibited irregularity in their ruffled borders, as reported in calcitonin administration, and many enlarged rough endoplasmic reticuli and vacuoles were observed. However, osteoclasts at 12 hours after administration, as well as the control, indicated recovery features from the effect of IP. Osteoblast proliferation and differentiation led to increasing alkaline phosphatase activity (ALPase) with time as well as the development of rough endoplasmic reticuli and Golgi apparatus with well-developed fine structure. These findings imply active synthesis of bone matrix. In our in vitro experiment, osteoclasts and osteoblasts displayed histochemical and fine structural characteristics similar to those observed in our in vivo experiment. Moreover, fewer TRACP-positive mononuclear cells were observed after 24-hour culture with IP than with the control. These results suggest that IP inhibits directly and/or indirectly differentiation and activity of osteoclasts and also promotes differentiation of osteoblast-lineage cells and their bone-forming activity.

Tartrate-resistant acid phosphatase as a biological marker of bone modelling and turnover in women in relation to their gonadal state

Abstract: SummarySerum tartrate-resistant acid phosphatase (TRAP) is considered a biological marker of bone resorption as it is synthesised by osteoclasts. Oestrogens inhibit bone resorption, and this may justify the influence of this hormone on osteoclastic activity. Thus, we have quantified serum TRAP levels in women to define their biological profile and observe any changes in relation to their hormone status.The TRAP level of 18 girls under 5 years of age was 8–1 ± 1–7 u/1. This value decreased (P< 0–001) in girls aged 5 to 12 years (n = 20, mean 6–3 ± 1–3 u/1). Following the menarche, another decrease was observed in 12 to 15 year old girls (n = 25, mean 5.5 ± 0–6u/l, P < 0–01). The mean TRAP value continued to decrease during the childbearing years, 16 to 48 (n = 40, 3.8 ± 0–3 u/1, P < 0–001). Finally, the mean level increased again at the menopause (n = 26, 4–5 ±0–4 u/1, P < 0–001). In women, serum TRAP changes reflect the dependence of bone modelling and turnover on hormone status.

Circulating levels of tartrate-resistant acid phosphatase in macrophage-activated lung disease.

Abstract: Tartrate-resistant acid phosphatase (TrACP) is abundant in alveolar macrophages, suggesting that these cells might contribute to the activity of this isoenzyme in sera of patients with conditions characterized by activation of alveolar macrophages. TrACP was therefore measured in patients with pulmonary sarcoidosis and cryptogenic fibrosing alveolitis and compared with values in controls. Since osteoclasts are known to be the main source of TrACP in serum several indices of bone-turnover were also measured: serum bone-specific alkaline phosphatase and urine hydroxyproline:creatinine ratios. Patients with Paget's disease of bone constituted a reference group presenting increased bone turnover. TrACP was not significantly higher in the lung-disease groups than in controls, although there was a strong positive correlation with angiotensin-converting enzyme in pulmonary sarcoidosis. As expected, TrACP activity was elevated together with the other indices of bone turnover in Paget's disease. It is unlikely that TrACP from alveolar macrophages contributes significantly to serum acid phosphatase activity in lung disease.

Functional and biochemical characterization of osteoclast-like cells derived from giant cell tumours of bone.

Abstract: Cells harvested from human giant cell tumours of bone were characterized on the basis of morphological features, proliferative capacity, total(AP) and tartrate resistant acid phosphatase (TRAP) activity, and hormonal response. Culture were formed by mononucleated and multinucleated cells. Mononucleated cells showed fibroblastic morphology, whereas multinucleated cells showed osteoclastic phenotype. We conclude that in these cultures mature osteoclasts and their mononuclear precursors are present.