Cysteine protease activity is up-regulated in inflamed ankle joints of rats with adjuvant-induced arthritis and decreases with in vivo administration of a vinyl sulfone cysteine protease inhibitor

ABSTRACTThe encystation ofAcanthamoebaleads to the formation of resilient cysts from vegetative trophozoites. This process is essential for parasite survival under unfavorable conditions, such as those associated with starvation, low temperatures, and biocides. Furthermore, cysteine proteases have been implicated in the massive turnover of intracellular components required for encystation. Thus, strict modulation of the activities of cysteine proteases is required to protectAcanthamoebafrom intracellular damage. However, mechanisms underlying the control of protease activity during encystation have not been established inAcanthamoeba. In the present study, we identified and characterizedAcanthamoebacysteine protease inhibitor (AcStefin), which was found to be highly expressed during encystation and to be associated with lysosomes by fluorescence microscopy. Recombinant AcStefin inhibited various cysteine proteases, including human cathepsin B, human cathepsin L, and papain. Transfection with small interfering RNA against AcStefin increased cysteine protease activity during encystation and resulted in incomplete cyst formation, reduced excystation efficiency, and a significant reduction in cytoplasmic area. Taken together, these results indicate that AcStefin is involved in the modulation of cysteine proteases and that it plays an essential role during the encystation ofAcanthamoeba.

Download Full-text

STEM-15. SerpinB3 DRIVES CANCER STEM CELL SURVIVAL IN GLIOBLASTOMA

Neuro-Oncology ◽

10.1093/neuonc/noab196.089 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi24-vi24

Author(s):

Adam Lauko ◽

Soumya M Turaga ◽

Josephine Volovetz ◽

Defne Bayik ◽

Shideng Bao ◽

...

Keyword(s):

Cell Death ◽

Protease Inhibitor ◽

Cysteine Protease ◽

Xenograft Model ◽

Standard Of Care ◽

Therapeutic Interventions ◽

Cysteine Protease Inhibitor ◽

Orthotopic Xenograft Model

Abstract Despite therapeutic interventions for glioblastoma (GBM), self-renewing, therapy-resistant populations of cells referred to as cancer stem cells (CSCs) drive recurrence. Previously, we identified the unique expression of junctional adhesion molecule-A (JAM-A) on CSCs and demonstrated that JAM-A is both necessary and sufficient for self-renewal and tumor growth. Moreover, we determined that JAM-A signals via Akt in GBM CSCs to sustain pluripotency transcription factor activity; however, the entire signaling network has yet to be fully elucidated. To further delineate this pathway, we immunoprecipitated JAM-A from patient-derived GBM CSCs and performed mass spectrometry to determine JAM-A binding proteins. This led to the identification of the cysteine protease inhibitor SerpinB3 as a putative JAM-A binding partner. Using in vitro CSC functional assays, we show that SerpinB3 is necessary for CSC maintenance and survival. In an in vivo orthotopic xenograft model, knockdown of SerpinB3 extended survival. Mechanistically, knockdown of SerpinB3 led to decreased expression of TGF-β, Myc, WNT, and Notch signaling, known regulators of the CSC state. Additionally, knockdown of SerpinB3 increases susceptibility to radiation therapy. SerpinB3 is essential for buffering cells against cathepsin-mediated cell death, and we found that elevated lysosomal membrane permeability after radiation leads to cathepsin release into the cytoplasm. As a result, SerpinB3 knockdown cells have a diminished capacity to inhibit cathepsin-driven cell death after radiation. The addition of the cathepsin inhibitor E64D partially rescues the SerpinB3 knockdown, however, SerpinB3 mutants that are unable to inhibit cathepsins fail to do the same. Taken together, our findings, identify a novel GBM CSC-specific survival mechanism involving a previously uninvestigated cysteine protease inhibitor, SerpinB3, and provide a potential target to increase the efficacy of standard of care GBM therapies against therapy-resistant CSCs.

Download Full-text

The Cysteine Protease Activity of the Major Dust Mite Allergen Der P 1 Selectively Enhances the Immunoglobulin E Antibody Response

Journal of Experimental Medicine ◽

10.1084/jem.190.12.1897 ◽

1999 ◽

Vol 190 (12) ◽

pp. 1897-1902 ◽

Cited By ~ 149

Author(s):

Lucy Gough ◽

Oliver Schulz ◽

Herb F. Sewell ◽

Farouk Shakib

Keyword(s):

Cysteine Protease ◽

Protease Activity ◽

Immunoglobulin E ◽

Specific Ige ◽

Cysteine Protease Inhibitor ◽

Cysteine Protease Activity ◽

Dust Mite ◽

Ige Synthesis ◽

Der P 1

The house dust mite Dermatophagoides pteronyssinus allergen Der p 1 is the most immunodominant allergen involved in the expression of dust mite–specific immunoglobulin (Ig)E–mediated hypersensitivity. The reason for this potent IgE-eliciting property of Der p 1 remains unknown, but there is mounting in vitro evidence linking the allergenicity of Der p 1 to its cysteine protease activity. Here we demonstrate for the first time that immunization of mice with proteolytically active Der p 1 results in a significant enhancement in total IgE and Der p 1–specific IgE synthesis compared with animals immunized with Der p 1 that was irreversibly blocked with the cysteine protease inhibitor E-64. We conclude that the proteolytic activity of Der p 1 is a major contributor to its allergenicity.

Download Full-text

ALG-097111, a potent and selective SARS-CoV-2 3-chymotrypsin-like cysteine protease inhibitor exhibits in vivo efficacy in a Syrian Hamster model

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2021.03.096 ◽

2021 ◽

Vol 555 ◽

pp. 134-139 ◽

Cited By ~ 1

Author(s):

Koen Vandyck ◽

Rana Abdelnabi ◽

Kusum Gupta ◽

Dirk Jochmans ◽

Andreas Jekle ◽

...

Keyword(s):

Protease Inhibitor ◽

Cysteine Protease ◽

Syrian Hamster ◽

Cysteine Protease Inhibitor ◽

Hamster Model ◽

In Vivo Efficacy

Download Full-text

Nippocystatin, a Cysteine Protease Inhibitor fromNippostrongylus brasiliensis, Inhibits Antigen Processing and Modulates Antigen-Specific Immune Response

Infection and Immunity ◽

10.1128/iai.69.12.7380-7386.2001 ◽

2001 ◽

Vol 69 (12) ◽

pp. 7380-7386 ◽

Cited By ~ 78

Author(s):

Teruki Dainichi ◽

Yoichi Maekawa ◽

Kazunari Ishii ◽

Tianqian Zhang ◽

Baher Fawzy Nashed ◽

...

Keyword(s):

Immune System ◽

Protease Inhibitor ◽

Cysteine Protease ◽

Antigen Processing ◽

Cysteine Proteases ◽

Cysteine Protease Inhibitor ◽

Host Immune System ◽

Nippostrongylus Brasiliensis

ABSTRACT During infection, parasites evade the host immune system by modulating or exploiting the immune system; e.g., they suppress expression of major histocompatibility complex class II molecules or secrete cytokine-like molecules. However, it is not clear whether helminths disturb the immune responses of their hosts by controlling the antigen-processing pathways of the hosts. In this study, we identified a new cysteine protease inhibitor, nippocystatin, derived from excretory-secretory (ES) products of an intestinal nematode,Nippostrongylus brasiliensis. Nippocystatin, which belongs to cystatin family 2, consists of 144 amino acids and is secreted as a 14-kDa mature form. In vivo treatment of ovalbumin (OVA)-immunized mice with recombinant nippocystatin (rNbCys) profoundly suppressed OVA-specific proliferation of splenocytes but not non-antigen-specific proliferation of splenocytes. OVA-specific cytokine production was also greatly suppressed in rNbCys-treated mice. Although the serum levels of both OVA-specific immunoglobulin G1 (IgG1) and IgG2a were not affected by rNbCys treatment, OVA-specific IgE was preferentially downregulated in rNbCys-treated mice. In vitro rNbCys inhibited processing of OVA by lysosomal cysteine proteases from the spleens of mice. Mice with anti-nippocystatin antibodies became partially resistant to infection with N. brasiliensis. Based on these findings, N. brasiliensis appears to skillfully evade host immune systems by secreting nippocystatin, which modulates antigen processing in antigen-presenting cells of hosts.

Download Full-text

Release of Signal Peptide Fragments into the Cytosol Requires Cleavage in the Transmembrane Region by a Protease Activity That Is Specifically Blocked by a Novel Cysteine Protease Inhibitor

Journal of Biological Chemistry ◽

10.1074/jbc.m005980200 ◽

2000 ◽

Vol 275 (40) ◽

pp. 30951-30956 ◽

Cited By ~ 92

Author(s):

Andreas Weihofen ◽

Marius K. Lemberg ◽

Hidde L. Ploegh ◽

Matthew Bogyo ◽

Bruno Martoglio

Keyword(s):

Protease Inhibitor ◽

Signal Peptide ◽

Cysteine Protease ◽

Protease Activity ◽

Cysteine Protease Inhibitor ◽

Peptide Fragments ◽

Transmembrane Region

Download Full-text

Antimalarial Activity of Allicin, a Biologically Active Compound from Garlic Cloves

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.5.1731-1737.2006 ◽

2006 ◽

Vol 50 (5) ◽

pp. 1731-1737 ◽

Cited By ~ 75

Author(s):

Alida Coppi ◽

Melissa Cabinian ◽

David Mirelman ◽

Photini Sinnis

Keyword(s):

Life Cycle ◽

Protease Inhibitor ◽

Cysteine Protease ◽

Malaria Infection ◽

Drug Targets ◽

Host Cells ◽

Cysteine Protease Inhibitor ◽

New Drug

ABSTRACT The incidence of malaria is increasing, and there is an urgent need to identify new drug targets for both prophylaxis and chemotherapy. Potential new drug targets include Plasmodium proteases that play critical roles in the parasite life cycle. We have previously shown that the major surface protein of Plasmodium sporozoites, the circumsporozoite protein (CSP), is proteolytically processed by a parasite-derived cysteine protease, and this processing event is temporally associated with sporozoite invasion of host cells. E-64, a cysteine protease inhibitor, inhibits CSP processing and prevents invasion of host cells in vitro and in vivo. Here we tested allicin, a cysteine protease inhibitor found in garlic extracts, for its ability to inhibit malaria infection. At low concentrations, allicin was not toxic to either sporozoites or mammalian cells. At these concentrations, allicin inhibited CSP processing and prevented sporozoite invasion of host cells in vitro. In vivo, mice injected with allicin had decreased Plasmodium infections compared to controls. When sporozoites were treated with allicin before injection into mice, malaria infection was completely prevented. We also tested allicin on erythrocytic stages and found that a 4-day regimen of allicin administered either orally or intravenously significantly decreased parasitemias and increased the survival of infected mice by 10 days. Together, these experiments demonstrate that the same cysteine protease inhibitor can target two different life cycle stages in the vertebrate host.

Download Full-text