Schistosoma japonicum cathepsin B2 (SjCB2) facilitates parasite invasion through the skin

Cercariae invasion of the human skin is the first step in schistosome infection. Proteases play key roles in this process. However, little is known about the related hydrolytic enzymes in Schistosoma japonicum. Here, we investigated the biochemical features, tissue distribution and biological roles of a cathepsin B cysteine protease, SjCB2, in the invasion process of S. japonicum cercariae. Enzyme activity analysis revealed that recombinant SjCB2 is a typical cysteine protease with optimum temperature and pH for activity at 37°C and 4.0, respectively, and can be totally inhibited by the cysteine protease inhibitor E-64. Immunoblotting showed that both the zymogen (50 kDa) and mature enzyme (30.5 kDa) forms of SjCB2 are expressed in the cercariae. It was observed that SjCB2 localized predominantly in the acetabular glands and their ducts of cercariae, suggesting that the protease could be released during the invasion process. The protease degraded collagen, elastin, keratin, fibronectin, immunoglobulin (A, G and M) and complement C3, protein components of the dermis and immune system. In addition, proteomic analysis demonstrated that SjCB2 can degrade the human epidermis. Furthermore, it was showed that anti-rSjCB2 IgG significantly reduced (22.94%) the ability of the cercariae to invade the skin. The cysteine protease, SjCB2, located in the acetabular glands and their ducts of S. japonicum cercariae. We propose that SjCB2 facilitates skin invasion by degrading the major proteins of the epidermis and dermis. However, this cysteine protease may play additional roles in host-parasite interaction by degrading immunoglobins and complement protein.

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In vitro ANTIGIARDIAL ACTIVITY OF THE CYSTEINE PROTEASE INHIBITOR E-64

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652014000100006 ◽

2014 ◽

Vol 56 (1) ◽

pp. 43-47 ◽

Cited By ~ 5

Author(s):

Thais Batista de Carvalho ◽

Teresa Cristina Goulart Oliveira-Sequeira ◽

Semiramis Guimaraes

Keyword(s):

Protease Inhibitor ◽

Cysteine Protease ◽

Cysteine Protease Inhibitor ◽

Parasite Survival ◽

Dye Reduction ◽

Antigiardial Activity ◽

Host Parasite ◽

Druggable Targets ◽

Vitro Effect

The quest for new antiparasitic alternatives has led researchers to base their studies on insights into biology, host-parasite interactions and pathogenesis. In this context, proteases and their inhibitors are focused, respectively, as druggable targets and new therapy alternatives. Herein, we proposed to evaluate the in vitro effect of the cysteine protease inhibitor E-64 on Giardia trophozoites growth, adherence and viability. Trophozoites (105) were exposed to E-64 at different final concentrations, for 24, 48 and 72 h at 37 °C. In the growth and adherence assays, the number of trophozoites was estimated microscopically in a haemocytometer, whereas cell viability was evaluated by a dye-reduction assay using MTT. The E-64 inhibitor showed effect on growth, adherence and viability of trophozoites, however, its better performance was detected in the 100 µM-treated cultures. Although metronidazole was more effective, the E-64 was shown to be able to inhibit growth, adherence and viability rates by ≥ 50%. These results reveal that E-64 can interfere in some crucial processes to the parasite survival and they open perspectives for future investigations in order to confirm the real antigiardial potential of the protease inhibitors.

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Organ-specific expression and epigenetic traits of genes encoding digestive enzymes in the lance-leaf sundew (Drosera adelae)

Journal of Experimental Botany ◽

10.1093/jxb/eraa560 ◽

2020 ◽

Author(s):

Naoki Arai ◽

Yusuke Ohno ◽

Shinya Jumyo ◽

Yusuke Hamaji ◽

Takashi Ohyama

Keyword(s):

Cysteine Protease ◽

Methylation Status ◽

Hydrolytic Enzymes ◽

Protein S ◽

Carnivorous Plants ◽

Specific Gene ◽

Specific Expression ◽

Genes Encoding ◽

Organ Specific ◽

Protein Components

Abstract Over the last two decades, extensive studies have been performed at the molecular level to understand the evolution of carnivorous plants. As fruits, the repertoire of protein components in the digestive fluids of several carnivorous plants have gradually become clear. However, the quantitative aspects of these proteins and the expression mechanisms of the genes that encode them are still poorly understood. In this study, using the Australian sundew Drosera adelae, we identified and quantified the digestive fluid proteins. We examined the expression and methylation status of the genes corresponding to major hydrolytic enzymes in various organs; these included thaumatin-like protein, S-like RNase, cysteine protease, class I chitinase, β-1, 3-glucanase, and hevein-like protein. The genes encoding these proteins were exclusively expressed in the glandular tentacles. Furthermore, the promoters of the β-1, 3-glucanase and cysteine protease genes were demethylated only in the glandular tentacles, similar to the previously reported case of the S-like RNase gene da-I. This phenomenon correlated with high expression of the DNA demethylase DEMETER in the glandular tentacles, strongly suggesting that it performs glandular tentacle-specific demethylation of the genes. The current study strengthens and generalizes the relevance of epigenetics to trap organ-specific gene expression in D. adelae. We also suggest similarities between the trap organs of carnivorous plants and the roots of non-carnivorous plants.

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Cysteine protease inhibitor of Schistosoma japonicum - A parasite-derived negative immunoregulatory factor

Parasitology Research ◽

10.1007/s00436-016-5363-0 ◽

2017 ◽

Vol 116 (3) ◽

pp. 901-908 ◽

Cited By ~ 6

Author(s):

Lin Chen ◽

Baohua He ◽

Wei Hou ◽

Li He

Keyword(s):

Protease Inhibitor ◽

Schistosoma Japonicum ◽

Cysteine Protease ◽

Cysteine Protease Inhibitor

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Faculty Opinions recommendation of VEGF-A induces angiogenesis by perturbing the cathepsin-cysteine protease inhibitor balance in venules, causing basement membrane degradation and mother vessel formation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1162504.624035 ◽

2009 ◽

Author(s):

Andrius Kazlauskas

Keyword(s):

Basement Membrane ◽

Protease Inhibitor ◽

Cysteine Protease ◽

Cysteine Protease Inhibitor ◽

Membrane Degradation ◽

Vessel Formation ◽

Basement Membrane Degradation

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A Novel Cysteine Protease Inhibitor of Naegleria fowleri That Is Specifically Expressed during Encystation and at Mature Cysts

Pathogens ◽

10.3390/pathogens10040388 ◽

2021 ◽

Vol 10 (4) ◽

pp. 388

Author(s):

Hương Giang Lê ◽

A-Jeong Ham ◽

Jung-Mi Kang ◽

Tuấn Cường Võ ◽

Haung Naw ◽

...

Keyword(s):

Protease Inhibitor ◽

Cysteine Protease ◽

Expression Profiles ◽

Critical Role ◽

Cyst Formation ◽

Cysteine Proteases ◽

Cysteine Protease Inhibitor ◽

Naegleria Fowleri ◽

Nægleria Fowleri ◽

Cystatin Family

Naegleria fowleri is a free-living amoeba that is ubiquitous in diverse natural environments. It causes a fatal brain infection in humans known as primary amoebic meningoencephalitis. Despite the medical importance of the parasitic disease, there is a great lack of knowledge about the biology and pathogenicity of N. fowleri. In this study, we identified and characterized a novel cysteine protease inhibitor of N. fowleri (NfCPI). NfCPI is a typical cysteine protease inhibitor belonging to the cystatin family with a Gln-Val-Val-Ala-Gly (QVVAG) motif, a characteristic motif conserved in the cystatin family of proteins. Bacterially expressed recombinant NfCPI has a dimeric structure and exhibits inhibitory activity against several cysteine proteases including cathespin Bs of N. fowleri at a broad range of pH values. Expression profiles of nfcpi revealed that the gene was highly expressed during encystation and cyst of the amoeba. Western blot and immunofluorescence assays also support its high level of expression in cysts. These findings collectively suggest that NfCPI may play a critical role in encystation or cyst formation of N. fowleri by regulating cysteine proteases that may mediate encystation or mature cyst formation of the amoeba. More comprehensive studies to investigate the roles of NfCPI in encystation and its target proteases are necessary to elucidate the regulatory mechanism and the biological significance of NfCPI.

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