1. |
- Leion, Felicia, et al.
(author)
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Estimating glomerular filtration rate (GFR) in children. The average between a cystatin C- and a creatinine-based equation improves estimation of GFR in both children and adults and enables diagnosing Shrunken Pore Syndrome.
- 2017
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In: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 77:5, s. 338-344
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Journal article (peer-reviewed)abstract
- Estimating glomerular filtration rate (GFR) in adults by using the average of values obtained by a cystatin C- (eGFRcystatin C) and a creatinine-based (eGFRcreatinine) equation shows at least the same diagnostic performance as GFR estimates obtained by equations using only one of these analytes or by complex equations using both analytes. Comparison of eGFRcystatin C and eGFRcreatinine plays a pivotal role in the diagnosis of Shrunken Pore Syndrome, where low eGFRcystatin C compared to eGFRcreatinine has been associated with higher mortality in adults. The present study was undertaken to elucidate if this concept can also be applied in children. Using iohexol and inulin clearance as gold standard in 702 children, we studied the diagnostic performance of 10 creatinine-based, 5 cystatin C-based and 3 combined cystatin C-creatinine eGFR equations and compared them to the result of the average of 9 pairs of a eGFRcystatin C and a eGFRcreatinine estimate. While creatinine-based GFR estimations are unsuitable in children unless calibrated in a pediatric or mixed pediatric-adult population, cystatin C-based estimations in general performed well in children. The average of a suitable creatinine-based and a cystatin C-based equation generally displayed a better diagnostic performance than estimates obtained by equations using only one of these analytes or by complex equations using both analytes. Comparing eGFRcystatin and eGFRcreatinine may help identify pediatric patients with Shrunken Pore Syndrome.
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2. |
- Sällman Almén, Markus, et al.
(author)
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Shrunken Pore Syndrome Is Associated With Increased Levels of Atherosclerosis-Promoting Proteins
- 2019
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In: Kidney International Reports. - : Elsevier BV. - 2468-0249. ; 4:1, s. 67-79
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Journal article (peer-reviewed)abstract
- Introduction: Shrunken pore syndrome (SPS), originally defined by cystatin C-based estimated glomerular filtration rate (eGFRcystatin C) being less than 60% of creatinine-based estimated glomerular filtration rate (eGFRcreatinine) in the absence of extrarenal influences on the plasma levels of cystatin C or creatinine, is associated with a high increase in mortality, even in the absence of reduced glomerular filtration rate (GFR). The objective of the present study was to determine whether the proteome of patients with SPS shows differences from that of patients with normal or reduced measured GFR (mGFR) without SPS.Methods: Four patient cohorts were included: 1 cohort with normal mGFR without SPS, 1 with normal mGFR with SPS, 1 with reduced mGFR without SPS, and 1 with reduced mGFR with SPS. The plasma levels of 177 selected proteins were analyzed.Results: Differences in the levels of 30 proteins were specific for SPS; 31 differences were specific for patients with both SPS and reduced mGFR; and 27 were specific for reduced mGFR. Eighteen of the differences specific for SPS concerned proteins described as promoting, or being associated with, atherosclerosis. Twelve of the differences specific for patients with both SPS and reduced mGFR and 10 of the differences specific for reduced mGFR also concerned proteins described as promoting, or being associated with, atherosclerosis. Almost all (82 of 88) of the concentration differences represented increased levels. For SPS, but not for reduced mGFR, a correlation between protein size and increase in level was observed, with smaller proteins being associated with higher levels.Conclusion: The high mortality in shrunken pore syndrome might be caused by the accumulation of atherosclerosis-promoting proteins in this condition.
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3. |
- Staniec, Dominika, et al.
(author)
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Calcium Regulates the Activity and Structural Stability of Tpr, a Bacterial Calpain-like Peptidase.
- 2015
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In: Journal of Biological Chemistry. - 1083-351X. ; 290:45, s. 27248-27260
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Journal article (peer-reviewed)abstract
- Porphyromonas gingivalis is a peptide-fermenting asaccharolytic periodontal pathogen. Its genome contains several genes encoding cysteine peptidases other than gingipains. One of these genes (PG1055) encodes a protein called Tpr (thiol protease), which has sequence similarity to cysteine peptidases of the papain and calpain families. In this study, we biochemically characterize Tpr. We found that the 55 kDa Tpr inactive zymogen proteolytically processes itself into active forms of 48 kDa, 37 kDa, and 33 kDa via sequential truncations at the N-terminus. These processed molecular forms of Tpr are associated with the bacterial outer membrane, where they are likely responsible for the generation of metabolic peptides required for survival of the pathogen. Both autoprocessing and activity were dependent on calcium concentrations greater than 1 mM, consistent with the protein's activity within the intestinal and inflammatory milieus. Calcium also stabilized the Tpr structure and rendered the protein fully resistant to proteolytic degradation by gingipains. Together, our findings suggest that Tpr is an example of a bacterial calpain, a calcium-responsive peptidase that may generate substrates required for the peptide-fermenting metabolism of P. gingivalis. Aside from nutrient generation, Tpr may also be involved in evasion of host immune response through degradation of the antimicrobial peptide LL-37 and complement proteins C3, C4 and C5. Taken together, these results indicate that Tpr likely represents an important pathogenesis factor for P. gingivalis.
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4. |
- Strålberg, Fredrik, et al.
(author)
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Inhibition of lipopolysaccharide-induced osteoclast formation and bone resorption in vitro and in vivo by cysteine proteinase inhibitors
- 2017
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In: Journal of Leukocyte Biology. - : FEDERATION AMER SOC EXP BIOL. - 0741-5400 .- 1938-3673. ; 101:5, s. 1233-1243
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Journal article (peer-reviewed)abstract
- Inflammation-induced bone destruction is a major treatment target in many inflammatory skeletal diseases. The aim of this study was to investigate if the cysteine proteinase inhibitors cystatin C, fungal cysteine proteinase inhibitor (E-64), and N-benzyloxycarbonyl-arginylleucyl-valyl-glycyl-diazomethane acetate (Z-RLVG-CHN2) can inhibit LPS-induced osteoclast formation. Mouse bone marrow macrophages (BMMs) were isolated and primed with receptor activator of NF-kappa B ligand (RANKL) for 24 h, followed by stimulation with LPS, with and without inhibitors. Adult mice were injected locally with LPS and then treated with E-64 and osteoclast formation assessed by the number of cathepsin K+ multinucleated cells. Cystatin C inhibited LPS-induced osteoclast formation time and concentration dependently (IC50 = 0.3 mu M). The effect was associated with decreased mRNA and protein expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K and of the osteoclastogenic transcription factors c-Fos and NFATc1. LPS-induced osteoclast formation on bone slices was also inhibited by cystatin C, resulting in decreased pit formation and release of bone matrix proteins. Similar data were obtained with E-64 and Z-RLVG-CHN2. Cystatin C was internalized in BMMs stimulated by LPS but not in unstimulated BMMs. Osteoclast formation induced by LPS was dependent on TNF-alpha, and the 3 inhibitors abolished LPS-induced TNF superfamily 2 (gene encoding TNF-alpha; Tnfsf2) mRNA expression without affecting Il1b, Il6, or oncostatin M (Osm) expression. Formation of osteoclasts in the skull bones after local LPS stimulation was inhibited by E-64. It is concluded that cysteine proteinase inhibitors effectively inhibit LPS-induced osteoclast formation in vivo and in vitro by inhibition of TNF-alpha expression. The targeting of cysteine proteinases might represent a novel treatment modality for prevention of inflammatory bone loss. RAHAMSON M, 1988, FEBS LETTERS, V236, P14 RAHAMSON M, 1990, BIOCHEMICAL JOURNAL, V268, P287
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5. |
- Wallin, Hanna, et al.
(author)
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Low-level internalization of cystatin E/M affects legumain activity and migration of melanoma cells
- 2017
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In: Journal of Biological Chemistry. - 0021-9258. ; 292:35, s. 14413-14424
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Journal article (peer-reviewed)abstract
- The ratio between proteases and their inhibitors is unbalanced in cancer. The cysteine protease inhibitor cystatin C is internalized by some cancer cells, which affects cellular properties. Here we aimed to investigate if uptake of cystatin C and the related inhibitor cystatin E/M occur in melanoma cell lines and to evaluate to what extent the uptake affects the legumain activity that is typically increased in melanoma. First we studied the basic expression, secretion, and intracellular content of all type 2 cystatins as well as expression and activity of their possible target enzymes legumain and cathepsin B in MDA-MB-435S, A375, and C8161 melanoma cells. Legumain activity was mea-sureable in all cell lines, and of the potential legumain inhibitors, cystatin C, E/M, and F, cystatin C was the one mainly produced. All cells internalized cystatin C added to culture media, leading to increased intracellular cystatin C levels by 120 –200%. Cystatin E/M was internalized as well but at a modest rate. The effects on intracellular legumain activity were nevertheless pronounced, probably because the cells lacked this inhibitor, and its affinity for legumain is 100-fold higher than that of cystatin C. Likewise, the low-degree uptake resulted in reduced migration and invasion of A375 cells in Matrigel to an extent comparable with the W106F variant of cystatin C with optimal uptake properties and resulting in much higher intracellular levels. Thus, cystatin E/M appears to be a good candidate to efficiently down-regulate the increased legumain activity, possibly important for the malignant phenotype of melanoma cells.
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