排序方式: 共有3条查询结果,搜索用时 0 毫秒
1
1.
Räikkönen J Taskinen M Dunford JE Mönkkönen H Auriola S Mönkkönen J 《Biochemical and biophysical research communications》2011,407(4):6647-667
A class of drugs successfully used for treatment of metabolic bone diseases is the nitrogen-containing bisphosphonates (N-BPs), which act by inhibiting the vital enzyme, farnesyl pyrophosphate synthase (FPPS), of the mevalonate pathway. Inhibition of FPPS by N-BPs results in the intracellular accumulation of isopentenyl pyrophosphate (IPP) and consequently induces the biosynthesis of a cytotoxic ATP analog (ApppI). Previous cell-free data has reported that N-BPs inhibit FPPS by time-dependent manner as a result of the conformational change. This associated conformational change can be measured as an isomerization constant (Kisom) and reflects the binding differences of the N-BPs to FPPS. In the present study, we tested the biological relevance of the calculated Kisom values of zoledronic acid, risedronate and five experimental N-BP analogs in the cell culture model. We used IPP/ApppI formation as a surrogate marker for blocking of FPPS in the mevalonate pathway.As a result, a correlation between the time-dependent inhibition of FPPS and IPP/ApppI formation by N-BPs was observed. This outcome indicates that the time-dependent inhibition of FPPS enzyme is a biologically significant mechanism and further supports the use of the Kisom calculations for evaluation of the overall potency of the novel FPPS inhibitors. Additionally, data illustrates that IPP/ApppI analysis is a useful method to monitor the intracellular action of drugs and drug candidates based on FPPS inhibition. 相似文献
2.
Subhajit Das Peter A. Edwards Julie C. Crockett Michael J. Rogers 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2014,1841(4):569-573
Nitrogen-containing bisphosphonates (N-BPs) such as zoledronic acid (ZOL) are the gold standard treatment for diseases of excessive bone resorption. N-BPs inactivate osteoclasts via inhibition of farnesyl diphosphate synthase (FPPS), thereby preventing the prenylation of essential small GTPases. Not all patients respond to N-BP therapy to the same extent, and some patients, for example with tumour-associated bone disease or Paget's disease, appear to develop resistance to N-BPs. The extent to which upregulation of FPPS might contribute to these phenomena is not clear. Using quantitative PCR and western blot analysis we show that levels of FPPS mRNA and protein can be upregulated in HeLa cells by culturing in lipoprotein deficient serum (LDS) or by over-expression of SREBP-1a. Upregulated, endogenous FPPS was predominantly localised to the cytosol and did not co-localise with peroxisomal or mitochondrial markers. Upregulation of endogenous FPPS conferred resistance to the inhibitory effect of low concentrations of ZOL on the prenylation of the small GTPase Rap1a. These observations suggest that an increase in the expression of endogenous FPPS could confer at least partial resistance to the pharmacological effect of N-BP drugs such as ZOL in vivo. 相似文献
3.
P.G. Dedes I. Kanakis Ch. Gialeli A.D. Theocharis T. Tsegenidis D. Kletsas G.N. Tzanakakis N.K. Karamanos 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Background
The interactions between metastatic breast cancer cells and host cells of osteoclastic lineage in bone microenvironment are essential for osteolysis. In vitro studies to evaluate pharmacological agents are mainly limited to their direct effects on cell lines. To mimic the communication between breast cancer cells and human osteoclasts, a simple and reproducible cellular model was established to evaluate the effects of zoledronate (zoledronic acid, ZOL), a bisphosphonate which exerts antiresorptive properties.Methods
Human precursor osteoclasts were cultured on bone-like surfaces in the presence of stimuli (sRANKL, M-CSF) to ensure their activation. Furthermore, immature as well as activated osteoclasts were co-cultured with MDA-MB-231 breast cancer cells. TRAP5b and type I collagen N-terminal telopeptide (NTx) were used as markers. Osteoclasts’ adhesion to bone surface and subsequent bone breakdown were evaluated by studying the expression of cell surface receptors and certain functional matrix macromolecules in the presence of ZOL.Results
ZOL significantly suppresses the precursor osteoclast maturation, even when the activation stimuli (sRANKL and M-SCF) are present. Moreover, it significantly decreases bone osteolysis and activity of MMPs as well as precursor osteoclast maturation by breast cancer cells. Additionally, ZOL inhibits the osteolytic activity of mature osteoclasts and the expression of integrin β3, matrix metalloproteinases and cathepsin K, all implicated in adhesion and bone resorption.Conclusions
ZOL exhibits a beneficial inhibitory effect by restricting activation of osteoclasts, bone particle decomposition and the MMP-related breast cancer osteolysis.General significance
The proposed cellular model can be reliably used for enhancing preclinical evaluation of pharmacological agents in metastatic bone disease. 相似文献
1