cathepsin B

Keratolytic winter erythema (KWE) is a rare autosomal-dominant skin disorder characterized by recurrent episodes of palmoplantar erythema and epidermal peeling. KWE was previously mapped to 8p23.1-p22 (KWE critical region) in South African families. Using targeted resequencing of the KWE critical region in five South African families and SNP array and whole-genome sequencing in two Norwegian families, we identified two overlapping tandem duplications of 7.67 kb (South Africans) and 15.93 kb (Norwegians). The duplications segregated with the disease and were located upstream of CTSB, a gene encoding cathepsin B, a cysteine protease involved in keratinocyte homeostasis. Included in the 2.62 kb overlapping region of these duplications is an enhancer element that is active in epidermal keratinocytes. The activity of this enhancer correlated with CTSB expression in normal differentiating keratinocytes and other cell lines, but not with FDFT1 or NEIL2 expression. Gene expression (qPCR) an...

The ability of Entamoeba histolytica trophozoites to destroy monolayers of baby hamster kidney cells is inhibited by allicin, one of the active principles of garlic. Cysteine proteinases, an important contributor to amebic virulence, as well as alcohol dehydrogenase, are strongly inhibited by allicin.

Combined effects of alprazolam (Alp), a member of benzodiazepine group of drugs and caffeine on human cell lines, HeLa and THP1 were investigated in this study. Alp mediated cytotoxicity was enhanced while caffeine was present. The cell death was confirmed by observing ...

Biochemical and genetic analysis of apoptosis has determined that intracellular proteases are key effectors of cell death pathways. In particular, early studies have pointed to the primacy of caspase proteases as mediators of execution. More recently, however, ...

Objective— Phosphatidylcholine hydroxyalkenals (PC-HAs) are a class of oxidized PCs derived from lipid peroxidation of arachidonate or linoleate at the sn -2 position to form terminal γ-hydroxy, α-, and β-unsaturated aldehydes. The aim of this study was to characterize some of their biological properties, ascertain the mechanism of their action, and assess whether they have in vivo relevance. Methods and Results— Combinations of cell biological approaches with radiolabels, mass spectroscopy, and immunochemical as well as immunohistochemical techniques were used to show that PC-HAs reduce the proteolytic degradation by mouse peritoneal macrophages (MPMs) of internalized macromolecules, such as maleylated bovine serum albumin, and that the activity of the lysosomal protease, cathepsin B, in MPMs form Michael adducts with MPM proteins and with N -acetylated cysteine in vitro form pyrrole adducts with MPM proteins and reduce the maturation of Rab5a, thereby impairing phagosome-lysosome ...

Cathepsin B (CtsB) is a lysosomal cysteine proteinase that is specifically translocated to the extracellular milieu during cancer progression. The development of a lipidated CtsB inhibitor incorporated into the envelope of a liposomal nanocarrier (LNC-NS-629) is described. Ex vivo and in vivo studies confirmed selective targeting and internalization of LNC-NS-629 by tumor and stromal cells, thus validating CtsB targeting as a highly promising approach to cancer diagnosis and treatment.

CONTEXT AND OBJECTIVE: Heparanase-1 degrades heparan sulfate and has been correlated with tumor progression. Although the isoform heparanase-2 has no catalytic activity, it seems to be important for modulating heparanase-1 activity. Cathepsin B is a proteinase involved in tumor metastasis. The aim of this study was to analyze heparanase isoform expression and cathepsin B activity in plasma samples from patients with gastrointestinal carcinomas, compared with healthy individuals (control group). DESIGN AND SETTING: This was an analytical cross-sectional study. Peripheral blood samples were collected at a Brazilian public hospital, from 21 patients with histopathological diagnoses of gastrointestinal carcinomas and from 43 healthy individuals. The analyses were performed in two Brazilian medical schools. METHODS: Heparanase isoforms were identified and quantified in plasma samples by means of Western blot. The enzymatic activities of heparanase-1 and cathepsin B were also measured. RE...

Vesicles shed by cancer cells are known to mediate several tumor-host interactions. Tumor microenvironment may, in turn, influence the release and the activity of tumor-shed microvesicles. In this study, we investigated the molecular mediators of the pH-dependent proinvasive activity of tumor-shed vesicles. Gelatinase zymography showed increased microvesicle activity of matrix metalloproteinases 9 and 2 as a result of acid exposure (pH 5.6) compared to pH 7.4. Thus, we reasoned that the cysteine protease cathepsin B might play a role in mediating the pH-dependent activation of gelatinases. Cathepsin B expression in tumor-shed microvesicles was confirmed by Western blot analysis and zymography. The activity of vesicle-associated cathepsin B measured using Z-Arg-Arg-pNA as substrate was significantly increased at acidic pH values. Inhibition of protease activity by the cysteine protease inhibitor, E-64, and treatment of ovarian cancer cells with small interfering RNA against cathepsin...

Cathepsin B was purified from normal human liver and several human tumour tissues and partially characterized. Three forms of cathepsin B, with molecular masses of 25 kDa, 26 kDa (the two appearing as a doublet) and 30 kDa, were detected in SDS/polyacrylamide gels. The 25-26 kDa doublet was associated with the fractions from tumours and normal liver containing the highest cathepsin B activity. Cathepsin B from both sources showed similar pH optima. Both normal liver and tumour cathepsin B exhibited similar kinetics against selected synthetic substrates. At neutral pH and 24 degrees C, cathepsin B from both normal liver and tumour exhibited a lower Km and a higher kcat./Km than at pH 6.0. Their inhibitory profiles against synthetic inhibitors were also similar. Immunological studies with a monospecific antibody against the mature double-chain form of human liver cathepsin B and an antibody against a cathepsin B-derived synthetic peptide established the immunological similarity of liv...

Schistosomiasis affects million people and its control is widely dependent on a single drug, praziquantel. Computational chemistry has led to the development of new tools that predict molecular properties related to pharmacological potential. We conducted a theoretical study of the imizadole alkaloids of Pilocarpus microphyllus (Rutaceae) with schistosomicidal properties. The molecules of epiisopiloturine, epiisopilosine, isopilosine, pilosine, and macaubine were evaluated using theory models (B3lyp/SDD, B3lyp/6-31+G(d,p), B3lyp/6-311++G(d,p)). Absorption, distribution, metabolization, excretion, and toxicity (ADMET) predictions were used to determine the pharmacokinetic and pharmacodynamic properties of the alkaloids. After optimization, the molecules were submitted to molecular docking calculations with the purine nucleoside phosphorylase, thioredoxin glutathione reductase, methylthioadenosine phosphorylase, arginase, uridine phosphorylase, Cathepsin B1 and histone deacetylase 8 e...

The growth of LS-lymphosarcoma in CBA mice was accompanied by a decrease in the content of the major extracellular inhibitor cystatin C in the tumor, plasma and, to a lesser extent, in tissues not involved in tumor process (liver and spleen). Cyclophosphamide in a dose of 50 mg/kg prolonged the life-span of animals and decreased tumor size by 80%. Cathepsin B and L activities in the tumor tissue increased by 3 and 7 times, respectively. Cystatin C content in the tumor tissue, spleen, and plasma also increased. Cystatin C assay in tumor tissue and plasma helps to predict the rate of tumor growth and to evaluate the efficiency of antitumor therapy.

The crystallographically determined structure of biologically active 4, 4-dichloro-1, 3-diphenyl-4-telluraoct-2-en-1-one, 3, shows the coordination geometry for Te to be distorted ��-pentagonal bipyramidal based on a C2OCl3 (lone pair) donor set. Notable is the presence of an intramolecular axial Te��� O (carbonyl) interaction, a design element included to reduce hydrolysis. Raman and molecular modelling studies indicate the persistence of the Te��� O (carbonyl) interaction in the solution (CHCl3) and gas-phases, respectively. ...

A premature and intracellular activation of digestive zymogens is thought to be responsible for the onset of pancreatitis. Because trypsin has a critical role in initiating the activation cascade of digestive enzymes in the gut, it has been assumed that trypsin also initiates intracellular zymogen activation in the pancreas. We have tested this hypothesis in isolated acini and lobules from rat pancreas. Intracellular trypsinogen activation was induced by supramaximal secretagogue stimulation and measured using either specific trypsin substrates or immunoreactivity of the trypsinogen activation peptide (TAP). To prevent a trypsin-induced trypsinogen activation, we used the cell-permeant, highly specific, and reversible inhibitor Nalpha-(2-naphthylsulfonyl)-3-amidinophenylalanine-carboxymethylpiperazide (S124), and to prevent cathepsin-induced trypsinogen activation, we used the cysteine protease inhibitor E-64d. Incubation of acini or lobules in the presence of S124 completely preven...

Cathepsin B is a ubiquitously expressed lysosomal cysteine protease that participates in protein turnover within lysosomes. However, its protein and activity levels have been shown to be increased in cancer. Cathepsin B endopeptidase activity is involved in the degradation of extracellular matrix, a process that promotes tumor invasion, metastasis and angiogenesis. Previously, we reported an established antibiotic nitroxoline as a potent and selective inhibitor of cathepsin B. In the present study, we elucidated its anti-tumor properties in in vitro and in vivo tumor models.Tumor and endothelial cell lines with high levels of active cathepsin B were selected for functional analysis of nitroxoline in vitro. Nitroxoline significantly reduced extracellular DQ-collagen IV degradation by all evaluated cancer cell lines using spectrofluorimetry. Nitroxoline also markedly decreased tumor cell invasion monitored in real time and reduced the invasive growth of multicellular tumor spheroids, ...

Objective: Isoproterenol (iso)-induced myocardial infarction is a widely used experimental model to study the beneficial effects of many drugs. Morinda citrifolia (noni) has traditionally been used for treating many diseases. Low-dose aspirin may have been protected heart tissueThis study aimed to investigate the possible protective effects of noni (20%) and low-dose aspirin (30 mg/kg) against iso-induced acute myocardial infarction in male Wistar rats. Materials and Methods: Rats were divided into control, iso, iso+noni, iso+aspirin, and iso+aspirin+noni groups (n=8). Myocardial infarction was induced by subcutaneous injection of iso (100 mg/kg) for two consecutive days. Iso-induced rats showed increased serum Creatine kinase-muscle brain CK-MB activity. The effects of noni (20%) and low-dose aspirin (30 mg/kg) were evaluated in response to iso-induced changes, Malondialdehyde (MDA), Superoxide Dismutase (SOD), Catalase (CAT), DNA fragmentation, caspase-3, and cathepsins B and L. Results: Oral treatment with 20% noni juice and low-dose aspirin (30 mg/kg) for 7 days significantly decreased apoptotic markers such as DNA fragmentation, caspase-3, and cathepsins B and L; increased antioxidant enzymes such as SOD and catalase activities; and decreased MDA levels. Conclusion: We propose that the protective effect, antiapoptotic and antioxidant mechanisms of noni and low dose aspirin may be on iso-induced myocardial infarction.

Sjögren's syndrome is a chronic autoimmune disease affecting the lacrimal glands and other epithelia. It has been suggested that acinar cells of the lacrimal glands provoke local autoimmune responses, leading to Sjögren's syndrome when they begin expressing major histocompatibility complex (MHC) class II molecules. We used isopycnic centrifugation and phase partitioning to resolve compartments that participate in traffic between the basolateral membranes and the endomembrane system to test the hypothesis that MHC class II molecules enter compartments that contain potential autoantigens, i.e., La/SSB, and enzymes capable of proteolytically processing autoantigen, i.e., cathepsins B and D. A series of compartments identified as secretory vesicle membranes, prelysosomes, and microdomains of the trans-Golgi network involved in traffic to the basolateral membrane, to the secretory vesicles, and to the prelysosomes were all prominent loci of MHC class II molecules, La/SSB, and cat...

Development of murine HA-1 hepatoma was accompanied by increased activity of cathepsin B (in ascitic cells), cathepsin D (in ascitic fluid) and increased activity of procathepsin B. There were some changes of cysteine proteinases in liver and spleen, not involved directly into tumor growth. The most prominent changes included the decreased level of cysteine proteinase inhibitors cystatin C and stefin A in ascitic cells (and to a lesser degree in liver tissue). During tumor development serum cystatin C concentration decreased by 3-times compared to intact mice. Treatment by antitumor drug Ukraine increased life span of mice with HA-1 hepatoma (transplanted intravenously), decreased the increment of tumor weight. In ascite such treatment caused a decrease of number of tumor cells and an increase of number of macrophages. Ukraie (administered once or 5-times in a dose of 0.5 mg per mice) increased cystatin C level, revealing protective mechanism of action.

Summary  Cathepsin B, purified from isolated islets of Langerhans, when incubated with proinsulin underin vitro conditions could convert proinsulin to insulin and C-peptide, releasing free arginine and lysine. When C-peptide, prepared from rat pancreas, was added to the incubation system consisting of proinsulin and cathepsin B, it completely inhibited the conversion of proinsulin to insulin.

It is well known that the activities of the lysosomal cysteine proteinases are tightly regulated by their endogenous inhibitors, cystatins. Here we report a new inhibitor of cysteine proteinases isolated from sea anemone Actinia equina. The inhibitor, equistatin, is an acidic protein with pI 4.7 and molecular weight of 14,129. It binds tightly and rapidly to cathepsin L (ka = 5.7 x 10(7) M-1 s-1, Ki = 0.051 nM) and papain (ka = 1.2 x 10(7) M-1 s-1, Ki = 0.57 nM). The lower affinity for cathepsin B (Ki = 1.4 nM) was shown to be due mainly to a lower second order association rate constant (ka = 0.04 x 10(6) M-1 s-1). The inhibitor is composed of 128 amino acids forming two repeated domains with 48% identity. Neither of the domains shows any sequence homology to cystatins, but they do show a significant homology to thyroglobulin type-1 domains. A highly conserved consensus sequence motif of Cys-Trp-Cys-Val together with conserved Cys, Pro, and Gly residues is present in major histocomp...

Gut extracts from cereal aphids (Sitobion avenae) showed significant levels of proteolytic activity, which was inhibited by reagents specific for cysteine proteases and chymotrypsin-like proteases. Gut tissue contained cDNAs encoding cathepsin B-like cysteine proteinases, ...

Experimental and clinical evidence has linked cathepsin B with tumour invasion and metastasis. Cathepsin B expression is increased in many human cancers at the mRNA, protein and activity levels. In addition, cathepsin B is frequently overexpressed in premalignant lesions, an observation that associates this protease with local invasive stages of cancer. Increased expression of cathepsin B in primary cancers, and especially in preneoplastic lesions, suggests that this enzyme might have pro-apoptotic features. Expression of cathepsin B is regulated at many different levels, from gene amplification, use of alternative promoters, increased transcription and alternative splicing, to increased stability and translatability of transcripts. During the transition to malignancy, a change in the localization of cathepsin B occurs, as demonstrated by the presence of cathepsin B-containing vesicles at the cell periphery and at the basal pole of polarized cells. Due to increased expression of cat...

Huanglonbing (HLB) is one of the most destructive disease affecting citrus plants. The causal agent is associated with the phloem-limited bacterium Candidatus Liberibacter asiaticus (CLas) and the psyllid Diaphorina citri, vector of disease, that transmits the bacterium associated with HLB. The control of disease can be achieved by suppressing either the bacterium or the vector. Among the control strategies for HLB disease, one of the widely used consists in controlling the enzymes of the disease vector, Diaphorina citri. The insect Diaphorina citri belongs to the order Hemiptera, which frequently have cysteine peptidases in the gut. The importance of this class of enzymes led us to search for enzymes in the D. citri transcriptome for the establishment of alternatives strategies for HLB control. In this study, we reported the identification and characterization of a cathepsin B-like cysteine peptidase from D. citri (DCcathB). DCcathB was recombinantly expressed in Pichia pastoris, p...

We show that mitochondrial DNA (mtDNA)-depleted 143B cells are hypersensitive to staurosporine-induced cell death as evidenced by a more pronounced DNA fragmentation, a stronger activation of caspase-3, an enhanced poly(ADP-ribose) polymerase-1 (PARP-1) cleavage, and a more dramatic cytosolic release of cytochrome c. We also show that B-cell CLL/lymphoma-2 (Bcl-2), B-cell lymphoma extra large (Bcl-XL), and myeloid cell leukemia-1 (Mcl-1) are constitutively less abundant in mtDNA-depleted cells, that the inhibition of Bcl-2 and Bcl-XL can sensitize the parental cell line to staurosporine-induced apoptosis, and that overexpression of Bcl-2 or Bcl-XL can prevent the activation of caspase-3 in ρ0143B cells treated with staurosporine. Moreover, the inactivation of cathepsin B with CA074-Me significantly reduced cytochrome c release, caspase-3 activation, PARP-1 cleavage, and DNA fragmentation in mtDNA-depleted cells, whereas the pan-caspase inhibitor failed to completely prevent PARP-1 c...