Cathepsins play an important role in protein degradation and processing. Aberrant cathepsin B or L is closely associated with many serious diseases such as cancer, osteoporosis and autoimmune ...disorders. Therefore, development of potent and selective cathepsin B and L inhibitors has aroused much attention in recent years. Although several classes of cathepsin inhibitors are presently available, there are still some problems to solve, such as broad-spectrum inhibition to protease, specially cysteine proteases, which lead to unpredictable side effects in clinical trials. Therefore, it is very necessary to discovery new scaffolds and new application of cathepsin B and L inhibitors for developing therapeutic agents for treating diseases mediated by cathepsin B or L. Areas covered: This updated review summarizes new patents on cathepsin B and L inhibitors from 2010 to present. Expert opinion: The review gives the latest development in the area of inhibitors of cathepsin B and L, which have been considered key therapeutic targets for the development of drugs treating related diseases. This review puts emphasis on the discovery of novel small molecule inhibitors of cathepsin B and L, as well as their new application as new therapeutic agents.
Emerging viruses such as severe fever and thrombocytopenia syndrome virus (SFTSV) and Ebola virus (EBOV) are responsible for significant morbidity and mortality. Host cell proteases that process the ...glycoproteins of these viruses are potential targets for antiviral intervention. The aspartyl protease signal peptide peptidase (SPP) has recently been shown to be required for processing of the glycoprotein precursor, Gn/Gc, of Bunyamwera virus and for viral infectivity. Here, we investigated whether SPP is also required for infectivity of particles bearing SFTSV-Gn/Gc. Entry driven by the EBOV glycoprotein (GP) and the Lassa virus glycoprotein (LASV-GPC) depends on the cysteine proteases cathepsin B and L (CatB/CatL) and the serine protease subtilisin/kexin-isozyme 1 (SKI-1), respectively, and was examined in parallel for control purposes. We found that inhibition of SPP and SKI-1 did not interfere with SFTSV Gn + Gc-driven entry but, unexpectedly, blocked entry mediated by EBOV-GP. The inhibition occurred at the stage of proteolytic activation and the SPP inhibitor was found to block CatL/CatB activity. In contrast, the SKI-1 inhibitor did not interfere with CatB/CatL activity but disrupted CatB localization in endo/lysosomes, the site of EBOV-GP processing. These results underline the potential of protease inhibitors for antiviral therapy but also show that previously characterized compounds might exert broader specificity than initially appreciated and might block viral entry via diverse mechanisms.
Human cathepsin X/Z is a biologically active homodimer Dolenc, Iztok; Štefe, Ivica; Turk, Dušan ...
Biochimica et biophysica acta. Proteins and proteomics,
February 2021, 2021-02-00, 20210201, Volume:
1869, Issue:
2
Journal Article
Peer reviewed
Human cathepsin X belongs to the cathepsin family of 11 lysosomal cysteine proteases. We expressed recombinant procathepsin X in Pichia pastoris in vitro and cleaved it into its active mature form ...using aspartic cathepsin E. We found, using size exclusion chromatography, X-ray crystallography, and small-angle X-ray scattering, that cathepsin X is a biologically active homodimer with a molecular weight of ~53 kDa. The novel finding that cathepsin X is a dimeric protein opens new horizons in the understanding of its function and the underlying pathophysiological mechanisms of various diseases including neurodegenerative disorders in humans.
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•Procathepsin X is activated by cathepsin E into mature form.•Cathepsin X exists as homodimer of Mw of ~53 kDa.•Both cathepsin X molecules exhibit an extensive binding surface.
The coronavirus disease 2019 (COVID-19) pandemics is a challenge without precedent for the modern science. Acute Respiratory Discomfort Syndrome (ARDS) is the most common immunopathological event in ...SARS-CoV-2, SARS-CoV, and MERS-CoV infections. Fast lung deterioration results of cytokine storm determined by a robust immunological response leading to ARDS and multiple organ failure. Here, we show cysteine protease Cathepsin L (CatL) involvement with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 from different points of view. CatL is a lysosomal enzyme that participates in numerous physiological processes, including apoptosis, antigen processing, and extracellular matrix remodeling. CatL is implicated in pathological conditions like invasion and metastasis of tumors, inflammatory status, atherosclerosis, renal disease, diabetes, bone diseases, viral infection, and other diseases. CatL expression is up-regulated during chronic inflammation and is involved in degrading extracellular matrix, an important process for SARS-CoV-2 to enter host cells. In addition, CatL is probably involved in processing SARS-CoV-2 spike protein. As its inhibition is detrimental to SARS-CoV-2 infection and possibly exit from cells during late stages of infection, CatL could have been considered a valuable therapeutic target. Therefore, we describe here some drugs already in the market with potential CatL inhibiting capacity that could be used to treat COVID-19 patients. In addition, we discuss the possible role of host genetics in the etiology and spreading of the disease.
Autophagy is a lysosomal degradative pathway that plays an important role in maintaining cellular homeostasis. We previously showed that the inhibition of autophagy causes pancreatic β-cell ...apoptosis, suggesting that autophagy is a protective mechanism for the survival of pancreatic β-cells. The current study demonstrates that treatment with inhibitors and knockdown of the lysosomal cysteine proteases such as cathepsins B and L impair autophagy, enhancing the caspase-dependent apoptosis of INS-1 cells and islets upon exposure to high concentration of glucose. Interestingly, treatment with cathepsin B and L inhibitors prevented the proteolytic processing of cathepsins B, D and L, as evidenced by gradual accumulation of the respective pro-forms. Of note, inhibition of aspartic cathepsins had no effect on autophagy and cell viability, suggesting the selective role of cathepsins B and L in the regulation of β-cell autophagy and apoptosis. Lysosomal localization of accumulated pro-cathepsins in the presence of cathepsin B and L inhibitors was verified via immunocytochemistry and lysosomal fractionation. Lysotracker staining indicated that cathepsin B and L inhibitors led to the formation of severely enlarged lysosomes in a time-dependent manner. The abnormal accumulation of pro-cathepsins following treatment with inhibitors of cathepsins B and L suppressed normal lysosomal degradation and the processing of lysosomal enzymes, leading to lysosomal dysfunction. Collectively, our findings suggest that cathepsin defects following the inhibition of cathepsin B and L result in lysosomal dysfunction and consequent cell death in pancreatic β-cells.
N-subsitutedbenzylidenebenzohydrazides and their cyclized derivatives i.e., 2,5-diaryl-1,3,4-oxadiazole are reported as novel inhibitors of cathepsin B, cathepsin H and cathepsin L with potency in ...nanomolar range. Display omitted
•The present work details about some non-peptidyl inhibitors of cathepsins B, H and L.•Differential inhibitory effect of compounds on cathepsins B, H and L was observed.•Precursors and derivatives were found to inhibit differentially.
High levels of cathepsins indicated in various pathological conditions like arthritis, cancer progressions, and atherosclerosis explains the need to explore potential inhibitors of these proteases which can be of great therapeutic significance. We, in the present work, report the synthesis of some 2,5-diaryloxadiazoles from N-subsitutedbenzylidenebenzohydrazides. The synthesized compounds were screened for their inhibitory potential on cathepsins B, H and L. Structure Activity Relationship studies show that 2,5-diaryloxadiazoles were less inhibitory than their precursors. 1i and 2k have been found to be most inhibitory to cathepsins B and L. Their Ki values have been calculated as 11.38×10−8M and 66.4×10−8M for cathepsin B and 4.2×10−9M and 47.31×10−9M for cathepsin L, respectively. However, cathepsin H activity was maximally inhibited by compounds, 1e and 2c with Ki values of 4.4×10−7M and 5.6×10−7M, respectively. Enzyme kinetic studies suggest that these compounds are competitive inhibitors to the enzymes. The results have been compared with docking results obtained using iGemDock.
Cysteine cathepsins (CTSs) are involved in the degradation and remodeling of the extracellular matrix and are associated with cellular transformation, differentiation, motility and adhesion in cancer ...development. Previous studies indicate that CTSs may be involved in ovarian cancer invasion and metastasis. However, due to the lack of large sample clinical studies and direct experimental evidence for the relationship between the expression of CTSs and invasion and metastasis, the diagnostic and prognostic value of CTSs in ovarian cancer progression has not been elucidated. In the present study, we observed that expression levels of CTSB, CTSL and CC in malignant ovarian tumors were significantly higher than the expression levels in benign tumors and normal ovarian tissues, yet their associations with clinicopathological features varied. In particular, CTSL was related to lymph node metastasis, CC was related to liver metastasis and omental metastasis, and CTSB and CTSL expression levels were found to be independent prognostic factors in ovarian cancer. Further study indicated that the serum level of CTSL was significantly higher in patients with ovarian malignant tumors than the levels in benign tumors and healthy controls, and the levels were elevated in low grade and advanced stage compared to the levels in high grade and early stage disease, suggesting that the serum level of CTSL may be a useful serum marker for the diagnosis of ovarian cancer. Furthermore, the expression of CTSL in ovarian cancer cells can greatly enhance the ability of cell invasion and metastasis, although no change was observed for cell adhesion. Taken together, we demonstrated that the overexpression of CTSL is involved in tumor invasion and metastasis, and the CTSL level in serum may be a marker for invasion and metastasis in ovarian cancer.
Until recently, chemiluminescence cell images could only be obtained using luciferase‐activated probes. Moreover, chemiluminescence microscopy cell‐imaging has not been demonstrated for natively ...expressed enzymes like cathepsin B. Herein, we describe the design, synthesis, and evaluation of the first chemiluminescence probe for the detection and imaging of cathepsin B. The probe activation mechanism relies on the release of a dioxetane intermediate, which undergoes chemiexcitation to emit green light with high efficiency under physiological conditions. Using the probe, we obtained clear images of cancerous leukemia and colon cells. This is the first demonstration of chemiluminescence cell images obtained by a probe for a natively expressed endogenous enzyme. We anticipate that the concept presented in this study will be broadly used to develop analogous probes for other important proteases relevant to biomolecular processes.
Chemiluminescence cell‐imaging: The first chemiluminescence probe for the detection of cathepsin B is described. The probe showed unprecedented sensitivity compared to that of a classic fluorescent probe for cathepsin B and provided the first chemiluminescence microscopy cell images of a natively expressed enzyme, thereby enabling differentiation between cancerous cells and normal tissue.
Tumorigenesis is associated with several changes that alter the cellular susceptibility to programmed cell death. Here, we show that immortalization and transformation sensitize cells in particular ...to the cysteine cathepsin-mediated lysosomal death pathway. Spontaneous immortalization increased the susceptibility of wild-type murine embryonic fibroblasts (MEFs) to tumor necrosis factor (TNF)-mediated cytotoxicity >1000-fold, whereas immortalized MEFs deficient for lysosomal cysteine protease cathepsin B (CathB) retained the resistant phenotype of primary cells. This effect was specific for cysteine cathepsins, because also lack of cathepsin L (a lysosomal cysteine protease), but not that of cathepsin D (a lysosomal aspartyl protease) or caspase-3 (the major executioner protease in classic apoptosis) inhibited the immortalization-associated sensitization of MEFs to TNF. Oncogene-driven transformation of immortalized MEFs was associated with a dramatic increase in cathepsin expression and additional sensitization to the cysteine cathepsin-mediated death pathway. Importantly, exogenous expression of CathB partially reversed the resistant phenotype of immortalized CathB-deficient MEFs, and the inhibition of CathB activity by pharmacological inhibitors or RNA interference attenuated TNF-induced cytotoxicity in immortalized and transformed wild-type cells. Thus, tumorigenesis-associated changes in lysosomes may counteract cancer progression and enhance therapeutic responses by sensitizing cells to programmed cell death.
Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers largely due to disseminated disease at the time of presentation. Here, we investigated the role and mechanism of action ...of the metastasis-associated protein anterior gradient 2 (AGR2) in the pathogenesis of pancreatic cancer. AGR2 was induced in all sporadic and familial pancreatic intraepithelial precursor lesions (PanIN), PDACs, circulating tumor cells, and metastases studied. Confocal microscopy and flow cytometric analyses indicated that AGR2 localized to the endoplasmic reticulum (ER) and the external surface of tumor cells. Furthermore, induction of AGR2 in tumor cells regulated the expression of several ER chaperones (PDI, CALU, RCN1), proteins of the ubiquitin-proteasome degradation pathway (HIP2, PSMB2, PSMA3, PSMC3, and PSMB4), and lysosomal proteases cathepsin B (CTSB) and cathepsin D (CTSD), in addition to promoting the secretion of the precursor form pro-CTSD. Importantly, the invasiveness of pancreatic cancer cells was proportional to the level of AGR2 expression. Functional downstream targets of the proinvasive activity of AGR2 included CTSB and CTSD in vitro, and AGR2, CTSB, and CTSD were essential for the dissemination of pancreatic cancer cells in vivo. Taken together, the results suggest that AGR2 promotes dissemination of pancreatic cancer and that its cell surface targeting may permit new strategies for early detection as well as therapeutic management.
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