Cathepsin S Levels and Survival Among Patients With Non-ST-Segment Elevation Acute Coronary Syndromes.

BACKGROUND: Patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) are at high residual risk for long-term cardiovascular (CV) mortality. Cathepsin S (CTSS) is a lysosomal cysteine protease with elastolytic and collagenolytic activity that has been involved in atherosclerotic plaque rupture. OBJECTIVES: The purpose of this study was to determine the following: 1) the prognostic value of circulating CTSS measured at patient admission for long-term mortality in NSTE-ACS; and 2) its additive value over the GRACE (Global Registry of Acute Coronary Events) risk score. METHODS: This was a single-center cohort study, consecutively recruiting patients with adjudicated NSTE-ACS (n = 1,112) from the emergency department of an academic hospital. CTSS was measured in serum using enzyme-linked immunosorbent assay. All-cause mortality at 8 years was the primary endpoint. CV death was the secondary endpoint. RESULTS: In total, 367 (33.0%) deaths were recorded. CTSS was associated with increased risk of all-cause mortality (HR for highest vs lowest quarter of CTSS: 1.89; 95% CI: 1.34-2.66; P < 0.001) and CV death (HR: 2.58; 95% CI: 1.15-5.77; P = 0.021) after adjusting for traditional CV risk factors, high-sensitivity C-reactive protein, left ventricular ejection fraction, high-sensitivity troponin-T, revascularization and index diagnosis (unstable angina/ non-ST-segment elevation myocardial infarction). When CTSS was added to the GRACE score, it conferred significant discrimination and reclassification value for all-cause mortality (Delta Harrell's C: 0.03; 95% CI: 0.012-0.047; P = 0.001; and net reclassification improvement = 0.202; P = 0.003) and CV death (AUC: 0.056; 95% CI: 0.017-0.095; P = 0.005; and net reclassification improvement = 0.390; P = 0.001) even after additionally considering high-sensitivity troponin-T and left ventricular ejection fraction. CONCLUSIONS: Circulating CTSS is a predictor of long-term mortality and improves risk stratification of patients with NSTE-ACS over the GRACE score.

An Immunosensor for the Determination of Cathepsin S in Blood Plasma by Array SPRi-A Comparison of Analytical Properties of Silver-Gold and Pure Gold Chips.

The array SPR imaging (SPRi) technique is well suited to the determination of biomarkers in body fluids, called liquid biopsy. No signal enhancement or analyte preconcentration is required. With the aim of achieving signal enhancement and lowering the cost of a single determination, the replacement of gold-covered chips by silver-gold chips was investigated. The aim of this work was to investigate the analytical characteristics of a biosensor formed on a Ag/Au chip and to compare them with those of a biosensor formed on a gold chip. A biosensor for the determination of cathepsin S (Cath S) was chosen as an example. The biosensor consisted of the linker cysteamine and an immobilized rat monoclonal antibody specific for cathepsin S. Both biosensors exhibited a Langmuirian response to Cath S concentration, with linear response ranging from LOQ to 1.5 ng mL-1. The LOQ is 0.1 ng mL-1 for the biosensor formed on the Ag/Au chip, and 0.22 ng mL-1 for that formed on the gold chip. Recoveries and precision for medium and high Cath S concentrations were acceptable for both biosensors, i.e., precision better than 10% and recoveries within the range 102-105%. However, the results for the lowest Cath S concentration were better for the biosensor formed on the Ag/Au chip (9.4 and 106% for precision and recovery, respectively). Generally, no significant differences in analytical characteristics were observed between the Ag/Au and Au chips. The two biosensors were also compared in the determination of Cath S in real samples. Nine plasma samples from healthy donors and nine from patients with ovarian cancer were analyzed for Cath S concentration with the biosensors formed on Ag/Au and Au chips. The results obtained with the two biosensors were very similar and show no significant differences on the Bland-Altman plot. The Cath S concentration in the blood plasma of ovarian cancer patients was elevated by one order of magnitude as compared with the control (12.6 ± 3.6 vs. 1.6 ± 1.2 ng mL-1).

Association of Circulating Cathepsin S and Cardiovascular Disease Among Patients With Type 2 Diabetes: A Cross-Sectional Community-Based Study.

Background: Cathepsin S, as an adipokine, was reported to play a critical role in various disease, including atherosclerosis and diabetes. The present study aims to elucidate the relationship between circulating cathepsin S and cardiovascular disease (CVD) in patients with type 2 diabetes. Methods: A total of 339 type 2 diabetes individuals were enrolled in this cross-sectional community-based study. Basic information, medical and laboratory data were collected. Serum cathepsin S levels were assessed by ELISA. Results: Compared to the CVD (-) group, levels of serum cathepsin S were significantly higher in the CVD (+) group, with the median 23.68 ng/ml (18.54-28.02) and 26.81 ng/ml (21.19-37.69) respectively (P < 0.001). Moreover, patients with acute coronary syndrome (ACS) had substantially higher levels of serum cathepsin S than those with stable angina pectoris (SAP), with the median 34.65 ng/ml (24.33-42.83) and 25.52 ng/ml (20.53-31.47) respectively (P < 0.01). The spearman correlation analysis showed that circulating cathepsin S was correlated with several cardiovascular risk factors. The univariate and multivariate logistic regression analysis revealed that circulating cathepsin S was an independent risk factor for CVD (all P < 0.001) after adjustment for potential confounders. Restricted cubic spline analysis showed circulating cathepsin S had a linearity association with CVD. In addition, receiver operating characteristic (ROC) curve analysis demonstrated that the area under curve (AUC) values of cathepsin S was 0.80 (95% CI: 0.75-0.84, P < 0.001), with the optimal cutoff value of cathepsin 26.28 ng/ml. Conclusion: Circulating cathepsin S was significantly higher in the CVD (+) group than that in the CVD (-) one among type 2 diabetes. The increased serum cathepsin S levels were associated with increased risks of CVD, even after adjusting for potential confounders. Thus, cathepsin S might be a potential diagnostic biomarker for CVD.

Circulating cathepsin S improves glycaemic control in mice.

Cathepsin S (CTSS) is a cysteine protease that regulates many physiological processes and is increased in obesity and type 2 diabetes. While previous studies show that deletion of CTSS improves glycaemic control through suppression of hepatic glucose output, little is known about the role of circulating CTSS in regulating glucose and energy metabolism. We assessed the effects of recombinant CTSS on metabolism in cultured hepatocytes, myotubes and adipocytes, and in mice following acute CTSS administration. CTSS improved glucose tolerance in lean mice and this coincided with increased plasma insulin. CTSS reduced G6pc and Pck1 mRNA expression and glucose output from hepatocytes but did not affect glucose metabolism in myotubes or adipocytes. CTSS did not affect insulin secretion from pancreatic ß-cells, rather CTSS stimulated glucagon-like peptide (GLP)-1 secretion from intestinal mucosal tissues. CTSS retained its positive effects on glycaemic control in mice injected with the GLP1 receptor antagonist Exendin (9-39) amide. The effects of CTSS on glycaemic control were not retained in high-fat-fed mice or db/db mice, despite the preservation of CTSS' inhibitory actions on hepatic glucose output in isolated primary hepatocytes. In conclusion, we unveil a role for CTSS in the regulation of glycaemic control via direct effects on hepatocytes, and that these effects on glycaemic control are abrogated in insulin resistant states.

Usefulness of Cathepsin S to Predict Risk for Obstructive Sleep Apnea among Patients with Type 2 Diabetes.

BACKGROUND: Obstructive sleep apnea (OSA) was highly prevalent in patients with type 2 diabetes (T2D). Cathepsin S (CTSS), a cysteine protease, is involved in the inflammatory activity in T2D and hypoxia conditions. The aim of the study was to evaluate whether CTSS could be involved in the inflammatory reaction of OSA in patients with T2D. METHODS: We included 158 participants in this study matched for age, gender, and body mass index in 4 groups (control, non-OSA&T2D, OSA&non-T2D, and OSA&T2D). After overnight polysomnography, we collected the clinical data including anthropometrical characteristics, blood pressure, and fasting blood samples in the morning. Plasma CTSS concentration was evaluated using the human Magnetic Luminex Assay. RESULTS: Compared with the control group, both the non-OSA&T2D group and the OSA&non-T2D group showed higher CTSS levels. Plasma CTSS expression was significantly increased in subjects with OSA&T2D compared to subjects with non-OSA&T2D. The OSA&T2D group had higher CTSS levels than the OSA&non-T2D group, but there were no statistically significant differences. Plasma CTSS levels showed significant correlation with the apnea-hypopnea index (AHI) (r = 0.559, P < 0.001) and plasma fasting blood glucose (r = 0.427, P < 0.001). After adjusting confounding factors, plasma CTSS levels were independently associated with the AHI (Beta: 0.386, 95% confidence intervals (CI): 21.988 to 57.781; P < 0.001). Furthermore, we confirmed the higher pinpoint accuracy of plasma CTSS in the diagnosis of OSA (area under the curve: 0.868). CONCLUSIONS: Plasma CTSS expression was significantly elevated in the OSA&T2D group and was independently associated with the AHI; it could be a biomarker with a positive diagnostic value on diagnosing OSA among patients with T2D.

High levels of cathepsin S and cystatin C in patients with fibromyalgia syndrome.

OBJECTIVES: Although the etiopathogenesis of fibromyalgia syndrome (FM) is not yet clear, central sensitization is thought to be responsible for the pathogenesis of FM. The aim of this study was to compare the serum cathepsin S (CatS) and cystatin C (CysC) levels between patients with FM and healthy control subjects. METHODS: This study was conducted in the Physical Medicine and Rehabilitation Clinic between January 2019 and October 2019. The study included 145 FM patients newly diagnosed with primary FM according to the 2010 American College of Rheumatology criteria and 129 healthy volunteers. The age, gender, and body mass index (BMI) of the participants were recorded. Venous blood samples were collected from both groups for the measurement of the levels of serum CatS and CysC. The functional status of FM patients was evaluated using the Fibromyalgia Impact Questionnaire (FIQ). RESULTS: No statistically significant difference was determined between the patient and control groups in terms of age, gender, and BMI (P > .05). A comparison of the serum CatS and CysC levels of the FM and control groups revealed a statistically significant difference (P = .001). No correlation was determined between FIQ and serum CatS and CysC levels (P > .05). CONCLUSION: Serum CatS and CysC levels were found to be higher in FM patients. However, there was no correlation between the functional status of FM patients and serum CatS and CysC levels. These results can be of guidance for further clinical studies of the etiopathogenesis and treatment of FM.

Plasma proteomic signature of the risk of developing mobility disability: A 9-year follow-up.

INTRODUCTION: Mobility disability is a powerful indicator of poor health in older adults. The biological and pathophysiological mechanism underlying the development of mobility disability remains unknown. This study conducted a data-driven discovery phase investigation to identify plasma proteins that predict the incidence of mobility disability in community-dwelling older adults without mobility disability at baseline. METHODS: We investigated 660 women and men, aged 71.9 ± 6.0 (60-94) years, who participated in the Invecchiare in Chianti, "Aging in the Chianti Area" study and completed the 400-m walk at fast pace (400-m walk) at enrollment. Median follow-up time was 8.57 [interquartile, 3.20-9.08] years. SOMAscan technology was used to measure 1,301 plasma proteins at enrollment. The incident of mobility disability was defined as inability to complete the 400-m walk. Protein-specific Cox proportional hazard model was adjusted for sex, age, and other important covariates. RESULTS: Plasma levels of 75 proteins predicted mobility disability (p < .05). Significant proteins were enriched for the KEGG "PI3K-Akt signaling," "phagosomes," and "cytokine-cytokine receptor interaction" pathways. After multiple comparison adjustment, plasma cathepsin S (CTSS; hazard ratio [HR] 1.33, 95% CI: 1.17, 1.51, q = 0.007), growth/differentiation factor 15 (GDF15; HR: 1.45, 95% CI: 1.23, 1.72, q = 0.007), and thrombospondin-2 (THBS2; HR: 1.44, 95% CI: 1.22, 1.69, q = 0.007) remained significantly associated with high risk of losing mobility. CONCLUSION: CTSS, GDF15, and THBS2 are novel blood biomarkers associated with new mobility disability in community-dwelling individuals. Overall, our analysis suggests that cellular senescence and inflammation should be targeted for prevention of mobility disability.

Proportional correlates of adipolin and cathepsin S in metabolic syndrome patients with and without prediabetes.

BACKGROUND: Adipolin and cathepsin S are intricately involved in pathophysiology of metabolic syndrome (MetS) and prediabetes (PreDM). AIMS & METHODS: This cross-sectional study aimed to compare and correlate between these metabolic biomarkers as well as between them and adiposity, atherogenicity and hematological indices in MetS patients. Our cross-sectional study involved recruiting 29 normoglycemic MetS, 30 newly diagnosed drug naïve PreDM-MetS patients versus 29 lean, healthy and normoglycemic controls. RESULTS: Adipolin and cathepsin S plasma levels were significantly higher in both MetS (normoglycemic and PreDM) groups vs. healthy controls. Evidently proportional adipolin-cathepsin S association was markedly signified in 59 MetS participants (normoglycemic and PreDM). Distinctively unlike adipolin, inverse cathepsin S-diastolic blood pressure (DBP) but direct cathepsin S-monocyte count and its monocyte -to- lymphocyte ratio cross-correlated were marked. Notably unlike cathepsin S, adipolin was positively associated with each of FPG, A1C and TG, visceral adiposity index, lipid accumulation product and atherogenic index of plsama in the MetS pool of participants (N = 59). CONCLUSIONS: Given the intergroup discrepancies in adiposity, atherogenicity indices and their correlations (as well as hematological indices) with biomarkers; this cross-sectional study cannot rule out either biomarker as an associative predictor or as a surrogate indicator and putative prognostic tool for the prediction/prevention and treatment of metabolism dysregularities.

Aberrant progranulin, YKL-40, cathepsin D and cathepsin S in Gaucher disease.

In Gaucher disease, several macrophage-specific biomarkers have been validated for use in the clinic. However, Gaucher disease is more complex involving system-wide pathophysiology beyond the macrophage, and based on gene array analysis in our Gaucher disease mouse model and other emerging pathophysiologic insights, we evaluated serum levels of cathepsins D and S, YKL-40 and progranulin in Gaucher disease patients. We assessed their biomarker potential in Gaucher disease and compared them to established Gaucher disease biomarkers, chitotriosidase, chemokine ligand 18 (CCL18), and other indicators of disease severity and response to therapy. Mean YKL-40 and cathepsin D and S levels were significantly higher in Gaucher disease patients compared to healthy controls; in contrast, mean progranulin levels were lower in Gaucher disease patients compared to healthy controls. Enzyme replacement therapy resulted in a significant reversal of elevated cathepsin D and S but there was no change in progranulin and YKL-40 levels. Patients with persistent splenomegaly after long-term enzyme replacement therapy had significantly higher serum YKL-40 than patients with smaller spleens (63.0 ±â€¯6.4 ng/ml vs. 46.4 ±â€¯4.3 ng/ml, p = .03). Serum YKL-40 levels were higher in subjects with severe bone involvement (Hermann Score 3 to 5) compared to those with milder bone involvement (Hermann Score 1 to 2) (70.1 ±â€¯4.3 ng/ml vs. 48.1 ±â€¯3.7 ng/ml, p = .0002). YKL-40 was only weakly associated with chitotriosidase (r = 0.2, p = .008) and CCL18 (r = 0.3, p = .0004), and cathepsin S was moderately associated with chitotriosidase (r = 0.4, p = .01) and CCL18 (r = 0.6, p < .0001). Receiver operating curves for progranulin and YKL-40 demonstrated areas under the curves of 0.80 and 0.70, respectively. In conclusion, while these biomarkers do not meet robust properties of established macrophage-specific biomarkers, they may inform severity of skeletal disease, contribution of fibrosis to residual splenomegaly, and other disease manifestations. These findings, including markedly low progranulin levels that do not change upon enzyme replacement therapy, are intriguing to prompt further investigations to decipher their role in pathophysiology and relevance to diverse phenotypes of Gaucher disease.

Nordic Diet and Inflammation-A Review of Observational and Intervention Studies.

Low-grade inflammation (LGI) has been suggested to be involved in the development of chronic diseases. Healthy dietary patterns, such as the Mediterranean diet (MD), may decrease the markers of LGI. Healthy Nordic diet (HND) has many similarities with MD, but its effects on LGI are less well known. Both of these dietary patterns emphasize the abundant use of fruits and vegetables (and berries in HND), whole grain products, fish, and vegetable oil (canola oil in HND and olive oil in MD), but restrict the use of saturated fat and red and processed meat. The aim of this narrative review is to summarize the results of studies, which have investigated the associations or effects of HND on the markers of LGI. Altogether, only two publications of observational studies and eight publications of intervention trials were found through the literature search. Both observational studies reported an inverse association between the adherence to HND and concentration of high sensitivity C-reactive protein (hsCRP). A significant decrease in the concentration of hsCRP was reported in two out of four intervention studies measuring hsCRP. Single intervention studies reported the beneficial effects on interleukin 1Ra and Cathepsin S. Current evidence suggests the beneficial effects on LGI with HND, but more carefully controlled studies are needed to confirm the anti-inflammatory effects of the HND.

Acute phase serum cathepsin S level and cathepsin S/cystatin C ratio are the associated factors with cerebral infarction and their diagnostic value for cerebral infarction.

Cathepsin S plays an important role in the pathogenesis of several cardiovascular diseases; however, the relationship between serum cathepsin S and cerebral infarction (CI) is still unknown. This study aimed to investigate the relationship between acute phase serum cathepsin S level and cerebral infarction. A total of 202 stroke patients were enrolled into this study, and were divided into cerebral infarction (n = 140) group and non-cerebral infarction group (non-CI, n = 62). Fifty healthy individuals were recruited as the control group. Serum levels of cathepsin S and cystatin C were measured at days 1, 7, and 14 posthospitalization. Compared to the non-CI group, the CI group had significantly higher rates of hypertension, dyslipidemia, and smoking (all P < 0.05). The CI group had significantly higher cathepsin S levels and cathepsin S to cystatin C ratio (CatS/CysC) at both days 1 and 7 posthospitalization (both P < 0.05). Multivariate logistic regression analysis demonstrated that cathepsin S level (day 7) and CatS/CysC (days 1 and 7) were the associated factors with CI (all P < 0.05). Receiver operating characteristic (ROC) curve analysis revealed that the Area Under Curve (AUC) value of CatS-day7, CatS/CysC-day1, and CatS/CysC-day7 were 0.726 (95% CI: 0.652-0.800, P < 0.001), 0.641 (95% CI: 0.559-0.723, P = 0.001), and 0.721 (95% CI: 0.645-0.797, P = 0.039), respectively. Cathepsin S and CatS/CysC were associated with acute CI, and may have the potential to be the diagnostic biomarkers for CI. Our findings help to better understand the role of serum cathepsin S level in CI.

Blood inflammatory and endothelial markers in women with von Willebrand disease.

INTRODUCTION: VWD-affected females often experience menorrhagia. Periodical fluctuations of the sex steroids during the menstrual cycle cause changes both in the coagulation and immune system. The aim of the current study was to assess the changes in selected inflammatory and endothelial markers in women with VWD during two phases of the menstrual cycle (follicular and luteal) and to compare it with corresponding data from healthy controls. MATERIALS AND METHODS: The study group included 12 VWD-affected females with regular menstrual cycle, with none of them being prescribed hormone treatment. They were not pregnant or breastfeeding. The control group consisted of 102 healthy females, matched for age and BMI. RESULTS: Within the VWD group, endostatin was higher during the follicular phase, compared to the luteal phase, although the difference was not significant (p = 0.062). sICAM-1 and IL-6 were higher in VWD-affected females, compared to the controls, sVCAM-1, cathepsin S and sP-selectin were lower (p<0.003 for all cases). The pattern was constant throughout the menstrual cycle. CONCLUSIONS: Higher levels of endostatin during early follicular phase could potentially predispose women with VWD to the development of heavy menstrual bleeding, due to antiangiogenic properties and ability to suppress several coagulation factors. Lower p-selectin levels in VWD group, compared to controls, may also contribute to the bleeding tendency. Changes in other proteins, involved in angiogenesis are hypothetically related to the formation of angiodysplasia-common complication of VWF deficiency. The latter statement requires confirmation in larger studies.

Increased plasma cathepsin S and trombospondin-1 in patients with acute ST-segment elevation myocardial infarction.

BACKGROUND: The role of cathepsins in the pathological progression of atherosclerotic lesions in ischem-ic heart disease have been defined in detail more than numerous times. This investigation examined the platelet-specific biomarker trombospondin-1 (TSP-1) and platelet function ex vivo, and compared this with cathepsin S (Cat-S; a biomarker unrelated to platelet activation but also associated this with increased mortality risk) in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: The STEMI patients were divided into two groups depending on the degree of coronary vessel occlusion: those with closed (n = 90) and open culprit vessel (n = 40). Cat-S and TSP-1 were analyzed before, 1-3 days after and 3 months after percutanous coronary intervention (PCI). RESULTS: During acute STEMI, plasma TSP-1 was significantly elevated in patients with closed cul-prit lesions, but rapidly declined after PCI. In fact, TSP-1 after PCI was significantly lower inpatient samples compared to healthy individuals. In comparison, plasma Cat-S was significantly elevated both before and after PCI. In patients with closed culprit lesions, Cat-S was significantly higher compared to patients with open culprit lesions 3 months after PCI. Although troponin-I were higher (p < 0.01) in patients with closed culprit lesion, there was no correlation with Cat-S and TSP-1. CONCLUSIONS: Cat-S but not TSP-1 may be a useful risk biomarker in relation to the severity of STEMI. However, the causality of Cat-S as a predictor for long-term mortality in STEMI remains to be ascertained in future studies.

Elevated circulating cathepsin S levels are associated with metabolic syndrome in overweight and obese individuals.

OBJECTIVE: Cathepsin S is highly expressed in subcutaneous and visceral adipose tissue. Cathepsin S correlates with central obesity and contributes to the formation and progression of atherosclerosis. Here, we sought to evaluate the association of serum cathepsin S with metabolic syndrome (MS) in overweight and obese Chinese adults. METHODS: We evaluated serum cathepsin S levels in a cross-sectional sample of 781 overweight and obese Chinese adults by ELISA. Glucose, insulin, lipid profile, inflammatory markers, and adipokines were also measured. RESULTS: Cathepsin S was significantly associated with BMI, waist circumference, waist-to-hip ratio, fasting glucose, fasting insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), systolic blood pressure, C-reactive protein (CRP), triglycerides, and HDL cholesterol (all P < 0.05). Plasma cathepsin S levels increased significantly (P = 0.045 for trend) with increasing numbers of MS components after adjustment for potential confounders. In the highest cathepsin S quartile, the MS risk was significantly higher (odds ratio 2.30; 95% confidence interval, 1.89-2.78) than in the lowest quartile after adjustment for age, gender, alcohol consumption, smoking, education, physical activity, self-reported CVD, and family history of diabetes. This association remained strong (odds ratio 1.97; 95% confidence interval, 1.72-2.48) after controlling further for CRP, adiponectin, HOMA-IR, and BMI. CONCLUSIONS: Elevated circulating cathepsin S concentrations are strongly and independently associated with MS in overweight and obese Chinese adults. Prospective studies are needed to establish the role of cathepsin S in the development of MS.

Cathepsin S, a new serum biomarker of sarcoidosis discovered by transcriptome analysis of alveolar macrophages.

BACKGROUND: Development of reliable new biomarkers remains crucial to improve diagnosis and assessing disease activity in sarcoidosis. The objective of this study was to seek such markers from the gene expression signature of alveolar macrophages by transcriptome analysis. METHODS: Pooled RNA extracted from alveolar macrophages from patients with active sarcoidosis and control patients was subjected to transcriptome analysis using microarrays. Expressed gene intensity in sarcoidosis relative to that in control was calculated. We measured serum cathepsin S (CTSS) concentrations in 89 healthy volunteers, 107 patients with sarcoidosis, 26 with interstitial pneumonia, 150 with pneumoconiosis, and 76 with pulmonary mycobacteriosis by the enzyme-linked immunosorbent assay. RESULTS: Among 12 genes with ratios higher than that of a housekeeping gene, we selected CTSS for scrutinizing protein expression in serum because of the feasibility of the protein assay. CTSS concentrations were significantly increased in sarcoidosis compared with not only controls but also all the other lung diseases. Receiver operating characteristics curve for sarcoidosis and parenchymal lung diseases revealed an area under the curve of 0.800 (95% confidence interval, 0.751-0.850; p=1.4 x 10-18) with 70% sensitivity and 78% specificity at a CTSS concentration of 15.5 ng/ml. A significant trend was identified between CTSS concentrations and the number of affected organs. Serum CTSS concentrations varied in parallel with clinical courses both spontaneously and in response to corticosteroid therapy. Epithelioid cells in granulomas were positive for immunohistochemical staining with CTSS. CONCLUSIONS: CTSS has the potential to be a useful biomarker in sarcoidosis.

Cathepsin B and S as markers for cardiovascular risk and all-cause mortality in patients with stable coronary heart disease during 10 years: a CLARICOR trial sub-study.

BACKGROUND AND AIMS: The lysosomal cysteine proteases cathepsin B and S have been implicated in the atherosclerotic process. The present paper investigates the association between serum levels of cathepsin B and S and cardiovascular events and mortality in patients with stable coronary heart disease. METHODS: The CLARICOR trial is a randomised, placebo-controlled trial investigating the effect of clarithromycin versus placebo in patients with stable coronary heart disease. The outcome was time to either a cardiovascular event or all-cause mortality. The placebo group was used as discovery sample and the clarithromycin group as replication sample: n = 1998, n = 1979; mean age (years) 65, 65; 31%, 30% women; follow-up for 10 years; number of composite outcomes n = 1204, n = 1220; respectively. We used a pre-defined multivariable Cox regression model adjusting for inflammation, established cardiovascular risk factors, kidney function, and use of cardiovascular drugs. RESULTS: Cathepsin B was associated with an increased risk of the composite outcome in both samples after multivariable adjustment (discovery: multivariable ratio (HR) per standard deviation increase 1.12, 95% confidence interval (CI) 1.05-1.19, p < 0.001, replication; HR 1.14, 95% CI 1.07-1.21, p < 0.001). There was no significant association between cathepsin S and the composite outcome in either the discovery or replication sample after multivariable adjustment (p>0.45). Secondary analyses suggest that cathepsin B was predominantly associated with mortality rather than specific cardiovascular events. CONCLUSIONS: Cathepsin B, but not serum cathepsin S, was associated with an increased risk of cardiovascular events in patients with stable coronary heart disease. The clinical implications of our findings remain to be established.

Apolipoprotein A-I proteolysis in aortic valve stenosis: role of cathepsin S.

Aortic valve stenosis (AVS) is the most common valvular heart disease in the Western world. Therapy based on apolipoprotein A-I (apoA-I), the major protein component of high-density lipoproteins, results in AVS regression in experimental models. Nevertheless, apoA-I degradation by proteases might lead to suboptimal efficacy of such therapy. An activatable probe using a quenched fluorescently labeled full-length apoA-I protein was generated to assess apoA-I-degrading protease activity in plasma derived from 44 men and 20 women with severe AVS (age 65.0 ± 10.4 years) as well as from a rabbit model of AVS. In human and rabbit AVS plasma, apoA-I-degrading protease activity was significantly higher than in controls (humans: 0.038 ± 0.009 vs 0.022 ± 0.005 RFU/s, p < 0.0001; rabbits: 0.033 ± 0.016 vs 0.017 ± 0.005 RFU/s, p = 0.041). Through the use of protease inhibitors, we identified metalloproteinases (MMP) as exerting the most potent proteolytic effect on apoA-I in AVS rabbits (67%, p < 0.05 vs control), while the cysteine protease cathepsin S accounted for 54.2% of apoA-I degradation in human plasma (p < 0.05 vs control) with the maximum effect seen in women (68.8%, p < 0.05 vs men). Accordingly, cathepsin S activity correlated significantly with mean transaortic pressure gradient in women (r = 0.5, p = 0.04) but not in men (r = - 0.09, p = 0.60), and was a significant independent predictor of disease severity in women (standardized beta coefficient 0.832, p < 0.001) when tested in a linear regression analysis. ApoA-I proteolysis is increased in AVS. Targeting circulating cathepsin S may lead to new therapies for human aortic valve disease.

Quantitative proteomics of plasma vesicles identify novel biomarkers for hemoglobin E/ß-thalassemic patients.

Hemoglobin E (HbE)/ß-thalassemia has a wide spectrum of clinical manifestations that cannot be explained purely by its genetic background. Circulating extracellular vesicles (EVs) are one factor that likely contributes to disease severity. This study has explored the differences in protein composition and quantity between EVs from HbE/ß-thalassemic patients and healthy individuals. We used tandem mass tag labeling mass spectrometry to analyze the EV proteins isolated from the plasma of 15 patients compared with the controls. To reduce biological variation between individuals, the EV proteins isolated from randomly assigned groups of 5 HbE/ß-thalassemic patients were pooled and compared with 5 pooled age- and sex-matched controls in 3 separate experiments. Alpha hemoglobin-stabilizing protein had the highest fold increase. Catalase, superoxide dismutase, T-complex proteins, heat shock proteins, transferrin receptor, ferritin, and cathepsin S were also upregulated in thalassemic circulating EVs. Importantly, haptoglobin and hemopexin were consistently reduced in patients' EVs across all data sets, in keeping with the existing hemolysis that occurs in thalassemia. The proteomic data analysis of EV samples isolated from 6 individual HbE/ß-thalassemic patients and western blotting results corroborated these findings. In conclusion, we have successfully identified consistent alterations of protein quantity between EVs from HbE/ß-thalassemic and healthy individuals. This work highlights haptoglobin, hemopexin, and cathepsin S as potential clinically relevant biomarkers for levels of hemolysis and inflammation. Monitoring of these plasma proteins could help in the clinical management of thalassemia.

Long-term endurance training increases serum cathepsin S levels in healthy female subjects.

BACKGROUND: Circulating cathepsin S (CS) has been associated with a lower risk for breast cancer in a large Swedish cohort. Long-term physical activity has been shown to have beneficial effects on the development of various cancer subtypes, in particular breast and colorectal cancers. The aim of this study was to investigate the effect of long-term endurance sport on CS levels in females. MATERIAL AND METHODS: Thirty-six of 40 subjects completed the study. Subjects were told to increase their activity pensum for 8 months reaching 150 min/week moderate or 75 min/week intense exercise. Ergometries were performed at the beginning and the end of the study to prove/quantify the performance gain. Blood samples were drawn at baseline and every 2 months. Serum CS levels were measured by ELISA. To analyse the change and the progression of CS, Wilcoxon rank sum and Friedman tests were used. RESULTS: The sportive group (performance gain by > 4.9%) showed a significant increase of CS levels from 3.32/2.73/4.09 to 4.00/3.09/5.04 ng/ml (p = 0.008) corresponding to an increase of 20.5%. CONCLUSIONS: We could show a significant increase of circulating CS levels in healthy female subjects induced by long-term physical activity. CS, occurring in the tumour microenvironment, is well-known to promote tumour growth, e.g. by ameliorating angiogenesis. However, the role of circulating CS in cancer growth is not clear. As physical activity is known as preventive intervention, in particular concerning breast and colorectal cancers, and long-term physical activity leads to an increase of CS levels in female subjects, circulating CS might even be involved in this protective effect. TRIAL REGISTRATION: Clinical trial registration: NCT02097199.

Less fibrosis in elderly subjects supplemented with selenium and coenzyme Q10-A mechanism behind reduced cardiovascular mortality?

BACKGROUND: In an intervention study where 221 healthy elderly persons received selenium and coenzyme Q10 as a dietary supplement, and 222 received placebo for 4 years we observed improved cardiac function and reduced cardiovascular mortality. As fibrosis is central in the aging process, we investigated the effect of the intervention on biomarkers of fibrogenic activity in a subanalysis of this intervention study. MATERIAL AND METHODS: In the present subanalysis 122 actively treated individuals and 101 controls, the effect of the treatment on eight biomarkers of fibrogenic activity were assessed. These biomarkers were: Cathepsin S, Endostatin, Galectin 3, Growth Differentiation Factor-15 (GDF-15), Matrix Metalloproteinases 1 and 9, Tissue Inhibitor of Metalloproteinases 1 (TIMP 1) and Suppression of Tumorigenicity 2 (ST-2). Blood concentrations of these biomarkers after 6 and 42 months were analyzed by the use of T-tests, repeated measures of variance, and factor analyses. RESULTS: Compared with placebo, in those receiving supplementation with selenium and coenzyme Q10, all biomarkers except ST2 showed significant decreased concentrations in blood. The changes in concentrations, that is, effects sizes as given by partial eta2 caused by the intervention were considered small to medium. CONCLUSION: The significantly decreased biomarker concentrations in those on active treatment with selenium and coenzyme Q10 compared with those on placebo after 36 months of intervention presumably reflect less fibrogenic activity as a result of the intervention. These observations might indicate that reduced fibrosis precedes the reported improvement in cardiac function, thereby explaining some of the positive clinical effects caused by the intervention. © 2017 BioFactors, 44(2):137-147, 2018.