Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Osteosarcoma is the most frequent malignant bone tumor with a poor survival rate for patients with metastasis. Previous studies have shown that beside other proteases, distinct sets of cathepsins are involved in the process of metastasis of different tumors. In this study we investigated the expression of cathepsin proteases in human osteosarcoma metastasis. First, the mRNA expression of 14 human cathepsins was studied in SAOS-2 osteosarcoma cells and the highly metastatic LM5 and LM7 sublines by reverse transcriptase (RT)-polymerase chain reaction (PCR). The expression of cathepsin D, K, and L mRNA was found upregulated and that of cathepsin F, H, and V downregulated in the highly metastatic LM5 and LM7 cells. A subgroup of the cathepsin proteases was further studied at the protein level by Western blot analysis of cell extracts. The expression of cathepsin B and H was decreased and that of cathepsin D, K, and L was increased in the highly metastatic cell lines as compared to the SAOS-2 cell line. Diagnostic relevance of cathepsin K expression in osteosarcoma was revealed upon correlation of survival and metastasis with immunohistochemical cathepsin K staining of biopsies collected from 92 patients prior to chemotherapy. Patients with metastatic high-grade osteosarcoma and low cathepsin K expression at diagnosis had a better prognosis than those with high expression. Thus, it appears that cathepsin K expression is of predictive prognostic value for patients with high-grade tumors and metastasis at diagnosis.
Mol Carcinog 2008 Jan
PMID:Cathepsins and osteosarcoma: Expression analysis identifies cathepsin K as an indicator of metastasis. 1768 65

Cathepsin K is a lysosomal cysteine protease that is a pharmacological target for the treatment of osteoporosis. Previous studies showed that basic, lipophilic cathepsin K inhibitors are lysosomotropic and have greater activities in cell-based assays against cathepsin K, as well as the physiologically important lysosomal cysteine cathepsins B, L, and S, than expected based on their potencies against these isolated enzymes. Long-term administration of the basic cathepsin K inhibitors N-(1-(((cyanomethyl)amino)carbonyl)cyclohexyl)-4-(2-(4-methyl-piperazin-1-yl)-1,3-thiazol-4-yl)benzamide (L-006235) and balicatib to rats at a supratherapeutic dose of 500 mg/kg/day for 4 weeks resulted in increased tissue protein levels of cathepsin B and L but had no effect on cathepsin B and L message. This is attributed to the inhibitor engagement of these off-target enzymes and their stabilization to proteolytic degradation. No such increase in these tissue cathepsins was detected at the same dose of N-(cyanomethyl)-N(2)-{(1S)-2,2,2-trifluoro-1-[4'-methylsulfonyl)biphenyl-4-yl]ethyl}-l-leucinamide (L-873724), a potent nonbasic cathepsin K inhibitor with a similar off-target profile, although all three inhibitors provided similar plasma exposures. Using an activity-based probe, (125)I-BIL-DMK, in vivo inhibition of cathepsins B, L, and S was detected in tissues of mice given a single oral dose of L-006235 and balicatib, but not in mice given L-873724. In each case, similar tissue levels were achieved by all three compounds, thereby demonstrating the in vivo cathepsin selectivity of L-873724. In conclusion, basic cathepsin K inhibitors demonstrate increased off-target cysteine cathepsin activities than their nonbasic analogs and potentially have a greater risk of adverse effects associated with inhibition of these cathepsins.
Mol Pharmacol 2008 Jan
PMID:Effect of cathepsin k inhibitor basicity on in vivo off-target activities. 1794 Jan 94

The biodistribution and pharmacokinetics of bone-targeting N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-alendronate conjugates were evaluated following intravenous administration of radioiodinated conjugates to young healthy BALB/c mice. The synthesis of a polymerizable and cathepsin K cleavable alendronate derivative, N-methacryloylglycylglycylprolylnorleucylalendronate, enabled the preparation of HPMA copolymer-alendronate conjugates with varying composition. Using the RAFT (reversible addition-fragmentation chain transfer) polymerization technique, four conjugates with different molecular weight and alendronate content and two control HPMA copolymers (without alendronate) with different molecular weight were prepared. The results of biodistribution studies in mice demonstrated a strong binding capacity of alendronate-targeted HPMA copolymer conjugates to bone. Conjugates with low (1.5 mol%) alendronate content exhibited a similar bone deposition capacity as conjugates containing 8.5 mol % of alendronate. The molecular weight was an important factor in the biodistribution of the HPMA copolymer conjugates. More conjugate structures need to be evaluated, but the data suggest that medium molecular weights (50-100 kDa) might be effective drug carriers for bone delivery.
Mol Pharm
PMID:Biodistribution and pharmacokinetic studies of bone-targeting N-(2-hydroxypropyl)methacrylamide copolymer-alendronate conjugates. 1850 66

The degradation of bone is a serious consequence of persistent bacterial infection, including periodontitis, infection-associated non-unions or osteomyelitis. To test the hypothesis that infection and inflammatory conditions promote the differentiation of monocytes to bone-resorbing osteoclasts, highly purified monocytes, or alternatively, cells of the promyeloid cell line U937, differentiated to monocyte-like cells, were cultivated in the presence of lipopolysaccharides (LPS) for up to 30 days. After 2-4 days, a massive aggregation of the cells was observed, after 15-20 days multinuclear cells with the morphological characteristics of osteoclasts became apparent. These cells expressed the osteoclast-typical proteins tartrate-resistant acid phosphate (TRAcP) and cathepsin K. Moreover, these cells formed resorption pits on calcium phosphate coated cover slips or ivory slices. To test whether the differentiation of the monocytes to osteoclast-like cells was mediated by tumour necrosis factor alpha (TNFalpha) secreted by the cells in culture, an antibody directed against TNFalpha was added together with LPS. Differentiation to osteoclast-like cells was inhibited, suggesting a paracrine effect of locally produced TNFalpha. In conclusion, we propose that local bacterial infections could create a microenvironment that promotes the generation of bone resorbing cells, which, in turn, could contribute to the infection-associated osteolysis.
Mol Immunol 2008 Jul
PMID:Lipopolysaccharides (LPS) induce the differentiation of human monocytes to osteoclasts in a tumour necrosis factor (TNF) alpha-dependent manner: a link between infection and pathological bone resorption. 1853 47

We investigated whether the effect of beta-cryptoxanthin (CRP) on osteoclastic cells formed in the mouse marrow culture system in vitro is enhanced by culture with zinc. Bone marrow cells were isolated from mice. The macrophage colony-stimulating factor (M-CSF)-dependent bone marrow macrophages were cultured in the presence of M-CSF (10 ng/ml) and receptor activator of nuclear factor-kappaB (NF-kappaB) ligand (RANKL; 50 ng/ml) for 96 h. The osteoclastic cells formed were further cultured for 24 or 72 h in a medium containing either vehicle, CRP, zinc sulfate (zinc), or CRP plus zinc with or without M-CSF (10 ng/ml) and RANKL (50 ng/ml). The number of osteoclastic cells was significantly decreased after culture with the combination of CRP (10(-7) M) and zinc (10(-5) M) in the presence or absence of M-CSF and RANKL for 24 or 72 h as compared with the value for CRP or zinc alone. Agarose gel electrophoresis showed the presence of low-molecular weight deoxyribonucleic acid (DNA) fragments of adherent cells cultured with CRP (10(-7) M) plus zinc (10(-5) M) for 24 or 72 h in the presence of M-CSF and RANKL, indicating that the combination of the two chemicals induces apoptotic cell death. CRP plus zinc-induced decrease in osteoclastic cells was significantly inhibited in the presence of caspase-3 inhibitor (10(-8) or 10(-7) M). Culture with CRP (10(-7) M) plus zinc ((10(-5) M) for 24 or 72 h caused a significant increase in caspase-3 mRNA expression in the presence or absence of M-CSF and RANKL as compared with the value for each chemical alone. CRP plus zinc-induced increase in caspase-3 mRNA expression was completely inhibited in the presence of cycloheximide (10(-7) M), an inhibitor of protein synthesis, or 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DBR; 10(-6) M), an inhibitor of transcription activity. The mRNA expression of tartrate-resistant acid phosphatase (TRACP) and cathepsin K was significantly decreased after culture with CRP plus zinc in the presence or absence of M-CSF and RANKL for 72 h as compared with CRP or zinc alone. Nuclear factor of activated T cells c1 (NFATc1) mRNA expression was significantly decreased after culture with CRP plus zinc in the presence or absence of M-CSF and RANKL for 72 h as compared with each chemical alone, while NF-kappaB mRNA expression was not significantly changed. This study demonstrated that the combination of CRP and zinc has potent suppressive effects on osteoclastic cells in vitro.
Int J Mol Med 2008 Aug
PMID:Combination of beta-cryptoxanthin and zinc has potent effects on apoptotic cell death and suppression of bone resorption-related gene expression in osteoclastic cells. 1863 77

Cathepsin K is the major collagenolytic enzyme produced by bone-resorbing osteoclasts. We showed earlier that the unique triple-helical collagen-degrading activity of cathepsin K depends on the formation of complexes with bone-or cartilage-resident glycosaminoglycans, such as chondroitin 4-sulfate (C4-S). Here, we describe the crystal structure of a 1:n complex of cathepsin K:C4-S inhibited by E64 at a resolution of 1.8 A. The overall structure reveals an unusual "beads-on-a-string"-like organization. Multiple cathepsin K molecules bind specifically to a single cosine curve-shaped strand of C4-S with each cathepsin K molecule interacting with three disaccharide residues of C4-S. One of the more important sets of interactions comes from a single turn of helix close to the N terminus of the proteinase containing a basic amino acid triplet (Arg8-Lys9-Lys10) that forms multiple hydrogen bonds either to the caboxylate or to the 4-sulfate groups of C4-S. Altogether, the binding sites with C4-S are located in the R-domain of cathepsin K and are distant from its active site. This explains why the general proteolytic activity of cathepsin K is not affected by the binding of chondroitin sulfate. Biochemical analyses of cathepsin K and C4-S mixtures support the presence of a 1:n complex in solution; a dissociation constant, K(d), of about 10 nM was determined for the interaction between cathepsin K and C4-S.
J Mol Biol 2008 Oct 31
PMID:The crystal and molecular structures of a cathepsin K:chondroitin sulfate complex. 1869 71

In a mouse model of mycobacteria-induced immunopathology, wild-type C57BL/6 (WT), IL-18-knockout (KO) and IFN-alphabeta receptor-KO mice developed circumscript, centrally necrotizing granulomatous lesions in response to aerosol infection with M. avium, whereas mice deficient in the IFN-gamma receptor, STAT-1 or IRF-1 did not exhibit granuloma necrosis. Comparative, microarray-based gene expression analysis in the lungs of infected WT and IRF-1-KO mice identified a set of genes whose differential regulation was closely associated with granuloma necrosis, among them cathepsin K, cystatin F and matrix metalloprotease 10. Further microarray-based comparison of gene expression in the lungs of infected WT, IFN-gamma-KO and IRF-1-KO mice revealed four distinct clusters of genes with variable dependence on the presence of IFN-gamma, IRF-1 or both. In particular, IRF-1 appeared to be directly involved in the differentiation of a type I immune response to mycobacterial infection. In summary, IRF-1, rather than being a mere transcription factor downstream of IFN-gamma, may be a master regulator of mycobacteria-induced immunopathology.
J Cell Mol Med 2009 Aug
PMID:Mycobacteria-induced granuloma necrosis depends on IRF-1. 1870 99

Intracellular signals involved in the maturation and function of osteoclasts are poorly understood. Here, we demonstrate that osteoclasts express multiple regulatory subunits of class I(A) phosphatidylinositol 3-kinase (PI3-K) although the expression of the full-length form of p85alpha is most abundant. In vivo, deficiency of p85alpha results in a significantly greater number of trabeculae and significantly lower spacing between trabeculae as well as increased bone mass in both males and females compared to their sex-matched wild-type controls. Consistently, p85alpha(-/-) osteoclast progenitors show impaired growth and differentiation, which is associated with reduced activation of Akt and mitogen-activated protein kinase extracellular signal-regulated kinase 1 (Erk1)/Erk2 in vitro. Furthermore, a significant reduction in the ability of p85alpha(-/-) osteoclasts to adhere to as well as to migrate via integrin alphavbeta3 was observed, which was associated with reduced bone resorption. Microarray as well as quantitative real-time PCR analysis of p85alpha(-/-) osteoclasts revealed a significant reduction in the expression of several genes associated with the maturation and migration of osteoclasts, including microphathalmia-associated transcription factor, tartrate-resistant acid phosphatase, cathepsin K, and beta3 integrin. Restoring the expression of the full-length form of p85alpha but not the version with a deletion of the Src homology-3 domain restored the maturation of p85alpha(-/-) osteoclasts to wild-type levels. These results highlight the importance of the full-length version of the p85alpha subunit of class I(A) PI3-K in controlling multiple aspects of osteoclast functions.
Mol Cell Biol 2008 Dec
PMID:The p85alpha subunit of class IA phosphatidylinositol 3-kinase regulates the expression of multiple genes involved in osteoclast maturation and migration. 1880 81

Secreted cysteine proteases are major players in host-parasite interactions; in Fasciola hepatica, a distinct group of cathepsins L was found to be predominantly expressed in the juvenile stages, but their enzymatic properties were unknown. Cathepsin L3 (FhCL3) is a main component of the juvenile secretory products and may participate in invasion. To characterize the biochemical properties, the proenzyme was expressed in the methylotrophic yeast Hansenula polymorpha and the mature enzyme was obtained from the culture medium. FhCL3 exhibited optimal activity and stability at neutral pH and a noticeable restricted substrate specificity with 70-fold preference for Tos-Gly-Pro-Arg-AMC over typical cathepsin substrates with hydrophobic or aliphatic residues in the S2 position. Accordingly, FhCL3 efficiently cleaved type I collagen over different pH and temperature conditions, but it did not cleave immunoglobulin. While most cathepsin cysteine proteinases are unable to digest collagen, mammalian cathepsin K, adult F. hepatica FhCL2 and the plant zingipain can also cleave collagen and substrates with Pro in P2 position, but only FhCL3 and zingipain hydrolyze these substrates with the highest efficiency. Molecular modeling and structural comparisons of the collagen cleaving cathepsins indicated that the strong substrate selectivity observed might be due to steric restrictions imposed by bulky aromatic residues at the S2-S3 subsites. The remarkable similarities of the active site clefts highlight the evolutive constrains acting on enzyme function. The presence of a collagen cleaving enzyme in F. hepatica juvenile stages is suggestive of a role in tissue invasion, an essential feature for the establishment of the parasites in their host.
Mol Biochem Parasitol 2009 Sep
PMID:The major cathepsin L secreted by the invasive juvenile Fasciola hepatica prefers proline in the S2 subsite and can cleave collagen. 1938 16

Cathepsin K (CTSK) was selected as a candidate gene for fat deposition in pigs because recently, in human and mouse, it was shown that this lysosomal proteinase is an obesity marker. A single nucleotide polymorphism (SNP) was identified in intron 4 of the porcine CTSK gene (g.15G>A; FM209043). Allele frequencies of this polymorphism were analysed in seven pig breeds. Radiation hybrid mapping confirmed the localization of CTSK to porcine chromosome 4, close to the FAT1 QTL region. Three populations of pigs (one Italian Large White and two Italian Duroc groups of pigs) were selected for association analysis. In the Italian Large White breed the g.15G>A SNP was not informative. Association analysis including all Italian Duroc pigs showed that the CTSK marker was associated with back fat thickness and lean cuts (P < 0.01), and average daily gain and feed:gain ratio (P < 0.05) estimated breeding values.
Mol Biol Rep 2010 Jan
PMID:A single nucleotide polymorphism in the porcine cathepsin K (CTSK) gene is associated with back fat thickness and production traits in Italian Duroc pigs. 1966 13


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