| 1. |
- Briggs, Jon J., et al.
(författare)
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Cystatin E/M suppresses legumain activity and invasion of human melanoma
- 2010
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: High activity of cysteine proteases such as legumain and the cathepsins have been shown to facilitate growth and invasion of a variety of tumor types. In breast cancer, several recent studies have indicated that loss of the cysteine protease inhibitor cystatin E/M leads to increased growth and metastasis. Although cystatin E/M is normally expressed in the skin, its role in cysteine protease regulation and progression of malignant melanoma has not been studied. Methods: A panel of various non-melanoma and melanoma cell lines was used. Cystatin E/M and C were analyzed in cell media by immunoblotting and ELISA. Legumain, cathepsin B and L were analyzed in cell lysates by immunoblotting and their enzymatic activities were analyzed by peptide substrates. Two melanoma cell lines lacking detectable secretion of cystatin E/M were transfected with a cystatin E/M expression plasmid (pCST6), and migration and invasiveness were studied by a Matrigel invasion assay. Results: Cystatin E/M was undetectable in media from all established melanoma cell lines examined, whereas strong immunobands were detected in two of five primary melanoma lines and in two of six lines derived from patients with metastatic disease. Among the four melanoma lines secreting cystatin E/M, the glycosylated form (17 kD) was predominant compared to the non-glycosylated form (14 kD). Legumain, cathepsin B and L were expressed and active in most of the cell lines, although at low levels in the melanomas expressing cystatin E/M. In the melanoma lines where cystatin E/M was secreted, cystatin C was generally absent or expressed at a very low level. When melanoma cells lacking secretion of cystatin E/M were transfected with pCST6, their intracellular legumain activity was significantly inhibited. In contrast, cathepsin B activity was not affected. Furthermore, invasion was suppressed in cystatin E/M over-expressing melanoma cell lines as measured by the transwell Matrigel assay. Conclusions: These results suggest that the level of cystatin E/M regulates legumain activity and hence the invasive potential of human melanoma cells.
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| 2. |
- Gregersen, Ida, et al.
(författare)
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Legumain in Acute Coronary Syndromes : A Substudy of the PLATO (Platelet Inhibition and Patient Outcomes) Trial
- 2020
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Ingår i: Journal of the American Heart Association. - : WILEY. - 2047-9980 .- 2047-9980. ; 9:17
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The cysteine protease legumain is increased in patients with atherosclerosis, but its causal role in atherogenesis and cardiovascular disease is still unclear. The aim of the study was to investigate the association of legumain with clinical outcome in a large cohort of patients with acute coronary syndrome. METHODS AND RESULTS : Serum levels of legumain were analyzed in 4883 patients with acute coronary syndrome from a substudy of the PLATO (Platelet Inhibition and Patient Outcomes) trial. Levels were analyzed at admission and after 1 month follow-up. Associations between legumain and a composite of cardiovascular death, spontaneous myocardial infarction or stroke, and its individual components were assessed by multivariable Cox regression analyses. At baseline, a 50% increase in legumain level was associated with a hazard ratio (HR) of 1.13 (95% CI, 1.04-1.21),P=0.0018, for the primary composite end point, adjusted for randomized treatment. The association remained significant after adjustment for important clinical and demographic variables (HR, 1.10; 95% CI, 1.02-1.19;P=0.013) but not in the fully adjusted model. Legumain levels at 1 month were not associated with the composite end point but were negatively associated with stroke (HR, 0.62; 95% CI, 0.44-0.88;P=0.0069), including in the fully adjusted model (HR, 0.57; 95% CI, 0.37-0.88;P=0.0114). CONCLUSIONS: Baseline legumain was associated with the primary outcome in patients with acute coronary syndrome, but not in the fully adjusted model. The association between high levels of legumain at 1 month and decreased occurrence of stroke could be of interest from a mechanistic point of view, illustrating the potential dual role of legumain during atherogenesis and acute coronary syndrome. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00391872.
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| 3. |
- Lunde, Ngoc Nguyen, et al.
(författare)
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Legumain is upregulated in acute cardiovascular events and associated with improved outcome - potentially related to anti-inflammatory effects on macrophages
- 2020
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Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 296, s. 74-82
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: We have previously found increased levels of the cysteine protease legumain in plasma and plaques from patients with carotid atherosclerosis. This study further investigated legumain during acute cardiovascular events.Methods: Circulating levels of legumain from patients and legumain released from platelets were assessed by enzyme-linked-immunosorbent assay. Quantitative PCR and immunoblotting were used to study expression, while localization was visualized by immunohistochemistry.Results: In the SUMMIT Malmo cohort (n = 339 with or without type 2 diabetes and/or cardiovascular disease [CVD], and 64 healthy controls), the levels of circulating legumain were associated with the presence of CVD in non-diabetics, with no relation to outcome. In symptomatic carotid plaques and in samples from both coronary and intracerebral thrombi obtained during acute cardiovascular events, legumain was co-localized with macrophages in the same regions as platelets. In vitro, legumain was shown to be present in and released from platelets upon activation. In addition, THP-1 macrophages exposed to releasate from activated platelets showed increased legumain expression. Interestingly, primary peripheral blood mononuclear cells stimulated with recombinant legumain promoted anti-inflammatory responses. Finally, in a STEMI population (POSTEMI; n = 272), patients had significantly higher circulating legumain before and immediately after percutaneous coronary intervention compared with healthy controls (n = 67), and high levels were associated with improved outcome.Conclusions: Our data demonstrate for the first time that legumain is upregulated during acute cardiovascular events and is associated with improved outcome.
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| 4. |
- Smith, Robert, et al.
(författare)
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Intra- and extracellular regulation of activity and processing of legumain by cystatin E/M
- 2012
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Ingår i: Biochimie. - : Elsevier BV. - 1638-6183 .- 0300-9084. ; 94:12, s. 2590-2599
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Tidskriftsartikel (refereegranskat)abstract
- Legumain, an asparaginyl endopeptidase, is up-regulated in tumour and tumour-associated cells, and is linked to the processing of cathepsin B, L, and proMMP-2. Although legumain is mainly localized to the endosomal/lysosomal compartments, legumain has been reported to be localized extracellularly in the tumour microenvironrnent and associated with extracellular matrix and cell surfaces. The most potent endogenous inhibitor of legumain is cystatin E/M, which is a secreted protein synthesised with an export signal. Therefore, we investigated the cellular interplay between legumain and cystatin E/M. As a cell model. HEK293 cells were transfected with legumain cDNA, cystatin E/M cDNA, or both, and over-expressing monoclonal cell lines were selected (termed M38L, M4C, and M3CL, respectively). Secretion of prolegumain from M38L cells was inhibited by treatment with brefeldin A, whereas bafilomycin A1 enhanced the secretion. Cellular processing of prolegumain to the 46 and 36 kDa enzymatically active forms was reduced by treatment with either substance alone. M38L cells showed increased, but M4C cells decreased, cathepsin L processing suggesting a crucial involvement of legumain activity. Furthermore, we observed internalization of cystatin E/M and subsequently decreased intracellular legumain activity. Also, prolegumain was shown to internalize followed by increased intracellular legumain processing and activation. In addition, in M4C cells incomplete processing of the internalized prolegumain was observed, as well as nuclear localized cystatin E/M. Furthermore, auto-activation of secreted prolegumain was inhibited by cystatin E/M, which for the first time shows a regulatory role of cystatin E/M in controlling both intra- and extracellular legumain activity. (C) 2012 Elsevier Masson SAS. All rights reserved.
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