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.

The Ovariectomized Mice and Rats

Abstract: The most common animals that are used for experimental studies are rodents, mainly rats and mice. Osteoporosis-related research is no exception. As early as 1985, ovariectomized (OVX) rats were used to study postmenopausal osteoporosis.

Cathepsin K regulates localization and secretion of Tartrate-Resistant Acid Phosphatase (TRAP) in TRAP-overexpressing MDA-MB-231 breast cancer cells

Abstract: Tartrate–resistant acid phosphatase (TRAP/ ACP5) belongs to the binuclear metallophosphatase family and is present in two isoforms. The primary translation product is an uncleaved TRAP 5a isoform with low phosphatase activity. TRAP 5a can be post-translationally processed to a cleaved TRAP 5b isoform with high phosphatase activity by e.g. cysteine proteinases, such as Cathepsin K (CtsK). The relevance of the phosphatase activity of TRAP 5b has been demonstrated for proliferation, migration and invasion of cancer cells. TRAP-overexpressing MDA-MB-231 breast cancer cells displayed higher levels of TRAP 5a and efficient processing of TRAP 5a to TRAP 5b protein, but no changes in levels of CtsK when compared to mock-transfected cells. In TRAP-overexpressing cells colocalization of TRAP 5a and proCtsK was augmented, providing a plausible mechanism for generation of TRAP 5b. CtsK expression has been associated with cancer progression and has been pharmacologically targeted in several clinical studies. In the current study, CtsK inhibition with MK-0822/Odanacatib did not abrogate the formation of TRAP 5b, but reversibly increased the intracellular levels of a N-terminal fragment of TRAP 5b and reduced secretion of TRAP 5a reversibly. However, MK-0822 treatment neither altered intracellular TRAP activity nor TRAP-dependent cell migration, suggesting involvement of additional proteases in proteolytic processing of TRAP 5a. Notwithstanding, CtsK was shown to be colocalized with TRAP and to be involved in the regulation of secretion of TRAP 5a in a breast cancer cell line, while it still was not essential for processing of TRAP 5a to TRAP 5b isoform. In cancer cells multiple proteases are involved in cleaving TRAP 5a to high-activity phosphatase TRAP 5b. However, CtsK-inhibiting treatment was able to reduce secretion TRAP 5a from TRAP-overexpressing cancer cells.

Ultrastructure, tartrate-resistant acid phosphatase activity and calcitonin responsiveness of osteoclasts at sites of demineralized bone matrix implant-induced osteogenesis.

Abstract: The morphology, ultrastructure, tartrate-resistance acid phosphatase reactivity, and calcitonin responsiveness of osteoclasts induced at sites of demineralized bone matrix (DBM) implant-induced osteogenesis in rats were determined. Osteoclasts at these ectopic sites had a morphologic and ultrastructural appearance similar to osteoclasts normally found in skeletal tissues. When observed by scanning electron microscopy, resorption surfaces on the implants had well-defined resorption pits (Howship's lacunae), indicative of active bone resorption. The osteoclasts stained intensely for tartrate-resistance acid phosphatase, an enzyme that is specific for osteoclasts. In response to human calcitonin, hypocalcemia occurred and osteoclasts lost their ruffled borders, indicating that these cells are responsive to exogenous hormonal stimulation. The osteoclasts induced by subcutaneous implantation of DBM had morphologic and functional characteristics similar to osteoclasts normally found in skeletal tissues.

Amphibian acid phosphatase--I. Biochemical characterization of the lysosomal enzyme, acid phosphatase, in tissues of Rana pipiens.

Abstract: 1. 1. The basic characteristics of acid phosphatase in amphibian skeletal tissues and plasma are similar to those of mammals. 2. 2. The pH optimum of frog bone acid phosphatase is 4.2, while that of plasma is 4.4; at higher pH levels, enzyme activity rapidly declines. 3. 3. Normal kinetic patterns of acid phosphatase activity occur when substrate and enzyme concentrations, and time and temperature of incubation in enzyme assays are varied. 4. 4. Plasma acid phosphatase is thermolabile, losing 22% of its activity at room temperature (1 hr); half-inactivation occurs at 60°C. In contrast, bone acid phosphatase is thermostable, retaining its original activity from 25 to 80°C. 5. 5. Frog bone acid phosphatase is not particle-bound to heavy components of bone mineral or matrix, and is localized within the lysosomes of skeletal cells. 6. 6. Tissue-specific variations of enzyme activity occur: the specific activity of acid phosphatase in the frog femoral diaphysis is 437-, 2-, 3- and 1.2-fold greater than activities in the plasma, coracoid, femoral epiphysis, and femoral metaphysis, respectively.

Biochemical markers of bone turnover. New aspect. Bone metabolic markers available in daily practice

Abstract: Changes of bone remodeling markers reflect bone growth and bone turnover Information on bone metabolism can be attained by blood and urine laboratory tests Recently developed bone specific markers are categorized by bone remodeling process, ie bone formation and resorption The formation markers include bone-specific alkaline phosphatase (BAP), osteocalcin (OC), undercarboxylated osteocalcin (ucOC), procollagene type I C- and N-terminal peptides (P1CP and P1NP) Bone resorption markers include deoxypyridinoline, collagen I C- and N-terminal telopeptides (CTX and NTX) , and tartrate resistent acid phosphatase (TRACP) isoform 5b These laboratory tests offer lots of advantages for the diagnosis of bone metabolic disorders and for the evaluation of clinical states of primary osteoporosis and other metabolic skeletal diseases