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).

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 β-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.

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.

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.

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 ± 6.4 ng/ml vs. 46.4 ± 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 ± 4.3 ng/ml vs. 48.1 ± 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.

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.

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.

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.

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.

Serum Cathepsin H as a Potential Prognostic Marker in Patients with Colorectal Cancer

Cathepsin H is a lysosomal cysteine protease that may participate in tumor progression. In order to evaluate its potential as a prognostic marker, its protein levels were measured by ELISA in preoperative sera from 324 patients with colorectal cancer. The level of cathepsin H was significantly increased in patient sera, the median level was 8.4 ng/mL versus 2.1 ng/mL in 90 healthy blood donors (p<0.0001). A weak association of cathepsin H levels was found with patient age (p=0.02) but not with Dukes’ stage, sex, or the level of carcinoembryonic antigen (CEA). In survival analysis a significant difference was found between the group of patients with low cathepsin H (first tertile) who had a poor prognosis and the remaining patients (p=0.03). The risk of patients was further stratified when cathepsin H levels were combined with CEA. Patients with high CEA and low cathepsin H had the highest risk of death with a hazard ratio of 2.72 (95% CI 1.73–4.28), p<.0001. Our results show that the prognostic information of cathepsin H differs from that of the related cathepsins B and L and suggest different roles during the progression of malignant disease.

Cathepsin S increases tau oligomer formation through limited cleavage, but only IL-6, not cathespin S serum levels correlate with disease severity in the neurodegenerative tauopathy progressive supranuclear palsy

Limited cleavage promotes the aggregation propensity of protein tau in neurodegenerative tauopathies. Cathepsin S (CatS) is overexpressed in brains of patients suffering from tauopathies such as Alzheimer's disease (AD). Furthermore, CatS serum levels correlate with survival in the elderly. The current study investigates whether limited cleavage by CatS promotes tau aggregation, and whether CatS serum levels may correlate with disease severity in tauopathies. Oligomer formation of fluorescently labeled protein tau was monitored by single particle fluorescence spectroscopy after coincubation with CatS. Tau cleavage patterns were investigated by SDS-PAGE. For serum analyses, samples were collected from 42 patients with probable progressive supranuclear palsy (PSP) according to NINDS-PSP criteria. Disease severity was assessed by PSP rating scale (PSP-RS), PSP staging system (PSP-S) and Schwab and England Activities of Daily Living (SEADL). CatS, cystatin C (CysC) and interleukin 6 (IL-6) serum levels were determined by ELISA, ECLIA and turbidimetry, respectively. SDS-PAGE demonstrated a distinct cleavage pattern of protein tau after coincubation with CatS. Furthermore, tau oligomer formation was increased 2.4-fold (p < 0.05) after limited cleavage. Serum CatS and CysC levels did not correlate with disease severity in PSP. Of note, IL-6 correlated with PSP-S (r = 0.41; 95% CI 0.11-0.65; p = 0.008), SEADL (r = -0.37; 95% CI -0.61 to -0.06; p = 0.017) and the history and gait/midline subdomains of the PSP-RS. While CatS facilitates tau aggregation in vitro, serum levels of CatS appear not to correlate with disease severity. The observed correlation of IL-6 with disease severity warrants further investigation of inflammatory markers in PSP.

[Oxidative carbonylation of proteins in experimental hind-limb ischaemia-reperfusion injury]

Formation of carbonylated protein derivatives is one of the key signalling pathways in cellular damage and may be regarded as a reliable marker in cellular injury. It allows evaluating both direct effects of reactive oxygen species and indirect interrelations with the secondary by-products of oxidation. The present study was undertaken to investigate the activity of lysosomal cysteine proteinases (cathepsins B and L) in blood serum and the arterial wall in an experimental model of ischaemia and ischaemia-reperfusion injury. To this was added comprehensive assessment of oxidative modification of proteins derived from blood serum and the arterial wall, namely, calculating the area under the curve of the absorption spectrum of the products of protein carbonylation, the proportion of the primary and secondary markers of oxidative stress, as well as the reserve and adaptation potential. The obtained findings were indicative of the development of oxidative stress in the model of ischaemia-reperfusion injury from day 1 to day 7, and in the ischaemia model on day 3 and day 5 in both the vascular wall and blood serum, which was accompanied by activation of cathepsins B and L. Reversible oxidation of proteins was observed on days 3 and 5 in the experimental ischaemia model and on days 1 and 7 in the ischaemia-reperfusion injury model, which was confirmed by the predominance of the primary markers of oxidative stress. Irreversible oxidation of proteins, i. e., the predominance of the secondary markers, was suggestive of the enhancement of oxidative stress, its transition to the late stage, leading to the loss of biological properties of proteins and eventually followed by their aggregation and degradation as seen in the ischaemia-reperfusion injury model on days 3 and 5. Analysing the obtained findings revealed direct correlation between the total area under the curve of oxidative modification of proteins and overall activity of cathepsin L in the ischaemia model: in blood serum on days 3 and 5, in the vascular wall for cathepsins B and L on day 5; in the ischaemia-reperfusion injury model: the activity of cathepsin L in blood serum on day 3, in the vascular wall on day 5 for cathepsins B and L.

Serum cathepsin S and cystatin C: relationship to subclinical carotid atherosclerosis in rheumatoid arthritis

OBJECTIVES

To assess whether serum cathepsin S and cystatin C, two novel markers of cardiovascular disease risk, are associated with subclinical carotid atherosclerosis in patients with rheumatoid arthritis (RA).

METHODS

Serum cystatin C and cathepsin S levels, carotid intima-media thickness (cIMT) and carotid plaques were assessed in a cross-sectional study involving 178 RA patients.

RESULTS

An association between disease activity scores with higher levels of cystatin C, but not with cathepsin S, was found. Cystatin C levels were also associated with cIMT in the patient subgroup included in the higher quartile of Cimt (OR 1.31, 95%CI [1.00-1.72], p=0.04) after adjusting for traditional cardiovascular risk factors, age and sex. An association between serum cystatin C levels and carotid plaques was also found in the univariate analysis (OR 1.37, 95%CI [1.06-1.76], p=0.02). However, this significant association was lost after adjusting for traditional cardiovascular risk factors and age. Cathepsin S was not associated with cIMT or carotid plaques.

CONCLUSIONS

High cystatin C serum levels identify a subgroup of RA patients with a high risk of subclinical atherosclerotic disease.

Immunodiagnosis of Fasciola gigantica Infection Using Monoclonal Antibody-Based Sandwich ELISA and Immunochromatographic Assay for Detection of Circulating Cathepsin L1 Protease

BACKGROUND

Tropical fasciolosis caused by Fasciola gigantica infection is one of the major diseases infecting ruminants in the tropical regions of Africa and Asia including Thailand. Parasitological diagnosis of fasciolosis is often unreliable and possesses low sensitivity. Therefore, the detection of circulating parasite antigens is thought to be a better alternative for diagnosis of fasciolosis, as it reflects the real parasite burden.

METHODS

In this study, we have produced a monoclonal antibody (MoAb) against recombinant F. gigantica cathepsin L1 (rFgCatL1), and developed both sandwich enzyme-linked immunosorbent assay (sandwich ELISA) and immunochromatographic (IC) test for rapid detection of circulating cathepsin L1 protease (CatL1) in the sera from mice experimentally and cattle naturally infected with Fasciola gigantica. MoAb 4E3 and biotinylated rabbit anti-recombinant CatL1 antibody were selected due to their high reactivities and specificities.

RESULTS

The lower detection limits of sandwich ELISA and IC test were 3 pg/ml and 0.256 ng/ml, respectively. Sandwich ELISA and IC test could detect F. gigantica infection from day 1 to 35 post infection. In experimental mice, the sensitivity, specificity and accuracy were 95%, 100% and 98.6% (for sandwich ELISA), and 93%, 100% and 98.2% (for IC test), while in natural cattle they were 98.3%, 100% and 99.5% (for sandwich ELISA), and 96.7%, 100% and 99.1% (for IC test).

CONCLUSIONS

These two assay methods showed high efficiencies and precisions for diagnosis of fasciolosis by F. gigantica.

Serum lipocalin-2, cathepsin S and chemerin levels and nonalcoholic fatty liver disease

Several novel circulating adipokines are associated with insulin resistance and inflammation. Little information exists in NAFLD about three recently recognized adipokines lipocalin-2, cathepsin S and chemerin. To assess the relationship between serum lipocalin-2, cathepsin S and chemerin levels and the development of non-alcoholic fatty liver in Chinese subjects, we measured serum lipocalin-2, cathepsin S and chemerin levels in 903 Chinese subjects by ELISA. Among the study population, 436 patients are with B-mode ultrasound-proven NAFLD and 467 controls. Levels of lipocalin-2, but not cathepsin S and chemerin, were significantly elevated in NAFLD versus control [lipocalin-2, 89.67 ± 4.47 vs. 68.70 ± 3.65 ng/mL (p < 0.001)]. After stepwise linear regression analysis adjusting for potential cofounders, further revealed that serum lipocalcin-2 was an independent predictor of NAFLD in whole cohort (standardized β = 0.114, t = 2.347, p = 0.02). Lipocalin-2 levels correlated with insulin resistance (homeostasis model assessment of insulin resistance) and inflammation (CRP) in whole cohorts and NAFLD, whereas cathepsin S and chemerin only correlated positively with insulin resistance and inflammation in whole cohorts. Our results indicated that circulating lipocalin-2, produced by adipocytes, are elevated and may contribute to the development of NAFLD. Serum lipocalin-2, which correlates with inflammation and insulin resistance, may have a direct pathogenic link to disease progression.

Life style intervention in moderately overweight individuals is associated with decreased levels of cathepsins L and S in plasma

BACKGROUND

Adipose tissue cells produce cathepsins L and S, which have proatherogenic effects. Obesity is strongly linked to atherogenesis, cardiovascular morbidity, and mortality.

OBJECTIVE

The aim of the present study was to see if life style interventions/weight reduction could decrease cathepsin L and S levels in blood plasma.

METHOD

Study subjects (n=31) were recruited to a life style intervention program aiming at increased physical activity, more healthy eating habits, and weight reduction for most of the participants. Blood samples were collected at inclusion and after 4 and 8 weeks.

RESULTS

Cathepsin L was significantly reduced at 4 weeks (p<0.0001) and 8 weeks (p=0.0004). A similar reduction was also seen for cathepsin S at 4 weeks (p=0.03) and 8 weeks (p=0.008). No significant change in fractalkine values was observed at 4 weeks (p=0.58), but a significant increase was apparent at 8 weeks (p=0.0002).

CONCLUSION

The intervention program resulted in significant reductions of cathepsin L and S levels in plasma after 4 and 8 weeks of intervention.

Plasma cathepsin S and cystatin C levels and risk of abdominal aortic aneurysm: a randomized population-based study

BACKGROUND

Human abdominal aortic aneurysm (AAA) lesions contain high levels of cathepsin S (CatS), but are deficient in its inhibitor, cystatin C. Whether plasma CatS and cystatin C levels are also altered in AAA patients remains unknown.

METHODS AND RESULTS

Plasma samples were collected from 476 male AAA patients and 200 age-matched male controls to determine CatS and cystatin C levels by ELISA. Student's t test demonstrated higher plasma levels of total, active, and pro-CatS in AAA patients than in controls (P<0.001). ROC curve analysis confirmed higher plasma total, active, and pro-CatS levels in AAA patients than in controls (P<0.001). Logistic regression suggested that plasma total (odds ratio [OR] = 1.332), active (OR = 1.21), and pro-CatS (OR = 1.25) levels were independent AAA risk factors that associated positively with AAA (P<0.001). Plasma cystatin C levels associated significantly, but negatively, with AAA (OR = 0.356, P<0.001). Univariate correlation demonstrated that plasma total and active CatS levels correlated positively with body-mass index, diastolic blood pressure, and aortic diameter, but negatively with the lowest ankle-brachial index (ABI). Plasma cystatin C levels also correlated negatively with the lowest ABI. Multivariate linear regression showed that plasma total, active, and pro-CatS levels correlated positively with aortic diameter and negatively with the lowest ABI, whereas plasma cystatin C levels correlated negatively with aortic diameter and the lowest ABI, after adjusting for common AAA risk factors.

CONCLUSIONS

Correlation of plasma CatS and cystatin C with aortic diameter and the lowest ABI suggest these serological parameters as biomarkers for human peripheral arterial diseases and AAA.

Investigation of two novel biochemical markers of inflammation, matrix metalloproteinase and cathepsin generated fragments of C-reactive protein, in patients with ankylosing spondylitis

OBJECTIVES

Ankylosing spondylitis (AS) is a chronic inflammation of the spine and the sacroiliac joints. Current markers of inflammation, such as C-reactive protein (CRP), are reflecting the production of an acute phase reactant rather than tissue specific inflammation, but the use of CRP as a diagnostic and prognostic marker for AS has not provided the sought accuracy and specificity. We hypothesized that local enzymatic activity in the disease-affected tissue, which is associated with extensive tissue turnover may, by cleavage, modify the CRP produced in the liver. These cleavage products may provide additional information on systemic inflammation as compared to that of full-length CRP. We investigated whether these CRP degradation products would provide additional diagnostic value in AS patients compared to full-length CRP.

METHODS

CRP fragments were identified by mass-spectrometry. Two fragments were selected for ELISA development. One assay exclusively identified a matrix metalloproteinase (MMP) generated fragment, CRP-MMP, whereas the other assay identified a cathepsin generated fragment, CRP-CAT. Full-length CRP, CRP-MMP and CRP-CAT were measured in serum samples from 40 AS patients and 40 sex- and age-matched controls.

RESULTS

Full-length CRP was not elevated in AS patients compared to controls, whereas CRP-MMP was elevated by 25% (p<0.001) and CRP-CAT by 50% (p<0.0001). The Area Under Curve of the Receiver-Operator Characteristic curve of CRP-CAT was the highest with 77%.

CONCLUSIONS

MMP and cathepsin degraded CRP provided more discriminative diagnostic potential compared to that of full-length CRP in this current study. These data suggest that different pools of CRP may provide insight into the inflammation processes in AS.

Association between serum cathepsin S and mortality in older adults

CONTEXT

Experimental data suggest that cathepsin S, a cysteine protease, is involved in the complex pathways leading to cardiovascular disease and cancer. However, prospective data concerning a potential association between circulating cathepsin S levels and mortality are lacking.

OBJECTIVE

To investigate associations between circulating cathepsin S levels and mortality in 2 independent cohorts of elderly men and women.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study using 2 community-based cohorts, the Uppsala Longitudinal Study of Adult Men (ULSAM; n = 1009; mean age: 71 years; baseline period: 1991-1995; median follow-up: 12.6 years; end of follow-up: 2006) and the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS; n = 987; 50% women; mean age: 70 years; baseline period: 2001-2004; median follow-up: 7.9 years; end of follow-up: 2010). Serum samples were used to measure cathepsin S.

MAIN OUTCOME MEASURE

Total mortality.

RESULTS

During follow-up, 413 participants died in the ULSAM cohort (incidence rate: 3.59/100 person-years at risk) and 100 participants died in the PIVUS cohort (incidence rate: 1.32/100 person-years at risk). In multivariable Cox regression models adjusted for age, systolic blood pressure, diabetes, smoking status, body mass index, total cholesterol, high-density lipoprotein cholesterol, antihypertensive treatment, lipid-lowering treatment, and history of cardiovascular disease, higher serum cathepsin S was associated with an increased risk for mortality (ULSAM cohort: hazard ratio [HR] for 1-unit increase of cathepsin S, 1.04 [95% CI, 1.01-1.06], P = .009; PIVUS cohort: HR for 1-unit increase of cathepsin S, 1.03 [95% CI, 1.00-1.07], P = .04). In the ULSAM cohort, serum cathepsin S also was associated with cardiovascular mortality (131 deaths; HR for quintile 5 vs quintiles 1-4, 1.62 [95% CI, 1.11-2.37]; P = .01) and cancer mortality (148 deaths; HR for 1-unit increase of cathepsin S, 1.05 [95% CI, 1.01-1.10]; P = .01).

CONCLUSIONS

Among elderly individuals in 2 independent cohorts, higher serum cathepsin S levels were associated with increased mortality risk. Additional research is needed to delineate the role of cathepsin S and whether its measurement might have clinical utility.

Serum cathepsin S is associated with serum C-reactive protein and interleukin-6 independently of obesity in elderly men

OBJECTIVE

Cathepsin S has been suggested provide a mechanistic link between obesity and atherosclerosis, possibly mediated via adipose tissue-derived inflammation. Previous data have shown an association between circulating cathepsin S and inflammatory markers in the obese, but to date, community-based reports are lacking. Accordingly, we aimed to investigate the association between serum levels of cathepsin S and markers of cytokine-mediated inflammation in a community-based sample, with prespecified subgroup analyses in nonobese participants.

METHODS

Serum cathepsin S, C-reactive protein (CRP), and IL-6 were measured in a community-based cohort of elderly men (Uppsala Longitudinal Study of Adult Men; mean age 71 years, n = 991). CRP and IL-6 were also measured at a reexamination after 7 yr.

RESULTS

After adjustment for age, body mass index, fasting plasma glucose, diabetes treatment, systolic blood pressure, diastolic blood pressure, hypertension treatment, serum cholesterol, serum high-density lipoprotein cholesterol, prior cardiovascular disease, smoking, and leisure time physical activity, higher cathepsin S was associated with higher CRP (regression coefficient for 1 sd increase, 0.13; 95% confidence interval 0.07-0.19; P < 0.001) and higher serum IL-6 (regression coefficient for 1 sd increase, 0.08; 95% confidence interval 0.01-0.14; P = 0.02). These associations remained similar in normal-weight participants (body mass index <25 kg/m(2), n = 375). In longitudinal analyses, higher cathepsin S at baseline was associated with higher serum CRP and IL-6 after 7 yr.

CONCLUSIONS

These results provide additional evidence for the interplay between cathepsin S and inflammatory activity and suggest that this association is present also in normal-weight individuals in the community.

Candidate serological biomarkers for cancer identified from the secretomes of 23 cancer cell lines and the human protein atlas

Although cancer cell secretome profiling is a promising strategy used to identify potential body fluid-accessible cancer biomarkers, questions remain regarding the depth to which the cancer cell secretome can be mined and the efficiency with which researchers can select useful candidates from the growing list of identified proteins. Therefore, we analyzed the secretomes of 23 human cancer cell lines derived from 11 cancer types using one-dimensional SDS-PAGE and nano-LC-MS/MS performed on an LTQ-Orbitrap mass spectrometer to generate a more comprehensive cancer cell secretome. A total of 31,180 proteins was detected, accounting for 4,584 non-redundant proteins, with an average of 1,300 proteins identified per cell line. Using protein secretion-predictive algorithms, 55.8% of the proteins appeared to be released or shed from cells. The identified proteins were selected as potential marker candidates according to three strategies: (i) proteins apparently secreted by one cancer type but not by others (cancer type-specific marker candidates), (ii) proteins released by most cancer cell lines (pan-cancer marker candidates), and (iii) proteins putatively linked to cancer-relevant pathways. We then examined protein expression profiles in the Human Protein Atlas to identify biomarker candidates that were simultaneously detected in the secretomes and highly expressed in cancer tissues. This analysis yielded 6-137 marker candidates selective for each tumor type and 94 potential pan-cancer markers. Among these, we selectively validated monocyte differentiation antigen CD14 (for liver cancer), stromal cell-derived factor 1 (for lung cancer), and cathepsin L1 and interferon-induced 17-kDa protein (for nasopharyngeal carcinoma) as potential serological cancer markers. In summary, the proteins identified from the secretomes of 23 cancer cell lines and the Human Protein Atlas represent a focused reservoir of potential cancer biomarkers.

[Cathepsin-like activity in blood plasma of patients with papillary thyroid carcinoma]

The peculiarities of the thyroid changes depending on clinical characteristics of disease and histological structure of tumor were fixed by the studies of cathepsin-like activity in blood plasma of patients with papillary thyroid carcinoma. H-cathepsin-like activity had a tendence to more significant increase especially in patients with concomitant benign thyroid disease with increasing the tumor category. In a case of metastatic tumor without other concomitant thyroid pathology, the degree of an increase in enzymatic activity was significantly higher comparing to the blood of patients without tumor metastases. B-cathepsin-like activity in blood plasma of patients only with tumor carcinoma was at the level of that of healthy subjects. B-cathepsin-like activity in blood plasma had especially significant increased under tumor T1 category that was connected with nodular goiter or adenoma in a case concominant carcinoma by other thyroid pathology. In patients with carcinoma that was diagnosed against a background of concomitant pathology, the insignificant increase in L-cathepsin-like activity was not dependent on clinical features of disease, while in a case of carcinoma without concomitant pathology a degree of its increase was certainly dependent on a category of tumor T, its histological structure and the presence of oxyphilic cell metaplasia. We failed to get an evidence linking the changes in cathepsin-like activity in blood with the processes of intra- or extrathyroid invasion and invasion into the lymphatic or blood vessels. The results of the studies do not provide a rationale to consider that the cathepsin-like activity in blood of patients with papillary thyroid carcinoma can be the valuable additional biochemical criterion for differential diagnosis, estimation of the severity, and other characteristics of the disease.

Relationship between plasma cathepsin S and cystatin C levels and coronary plaque morphology of mild to moderate lesions: an in vivo study using intravascular ultrasound

BACKGROUND

Cathepsin S and its endogenous inhibitor cystatin C are implicated in the pathogenesis of atherosclerosis, especially in the plaque destabilization and rupture leading to acute coronary syndrome. However, whether circulating cathepsin S and cystatin C also change in association with coronary plaque morphology is unknown yet.

METHODS

We recruited 98 patients with unstable angina (UA, n = 6) or stable angina (SA, n = 2) who had a segmental stenosis resulting in > 20% and < 70% diameter reduction in one major coronary artery on coronary angiography. Thirty-one healthy subjects served as controls. Intravascular ultrasound (IVUS) was used to evaluate plaque morphology. Plasma cathepsin S and cystatin C were measured as well.

RESULTS

At the culprit lesion site, plaque area ((7.85 +/- 2.83) mm(2) vs (6.53 +/- 2.92) mm(2), P = 0.027), plaque burden ((60.92 +/- 11.04)% vs (53.87 +/- 17.52)%, P = 0.025), remodeling index (0.93 +/- 0.16 vs 0.86 +/- 0.10, P = 0.004) and eccentricity index (0.74 +/- 0.17 vs 0.66 +/- 0.21, P = 0.038) were bigger in UA group than in SA group. Plasma cathepsin S and cystatin C were significantly higher in patients than in controls (P < 0.01). Plasma cathepsin S was higher in UA group ((0.411 +/- 0.121) nmol/L) than in SA group ((0.355 +/- 0.099) nmol/L, P = 0.007), so did the plasma cystatin C ((0.95 +/- 0.23) mg/L in UA group, (0.84 +/- 0.22) mg/L in SA group; P = 0.009). Plasma cathepsin S positively correlated with remodeling index (r = 0.402, P = 0.002) and eccentricity index (r = 0.441, P = 0.001), and plasma cystatin C positively correlated with plaque area (r = 0.467, P < 0.001) and plaque burden (r = 0.395, P = 0.003) in UA group but not in SA group.

CONCLUSIONS

Plasma cathepsin S and cystatin C increased significantly in UA patients. In angina patients, higher plasma cathepsin S may suggest the presence of vulnerable plaque, and higher plasma cystatin C may be a clue for larger atherosclerotic coronary plaque.

[Serum activity of chitotriosidase, lysozyme and cathepsin H in patients with lung cancer and patients with inflammatory exudate (preliminary report)]

Lung cancer remains the leading cause of cancer death over the world. Although new diagnostic methods have been discovered, new biomarkers of the cancer are still under studying. A human chitinolytic enzyme called chitotriosidase hydrolyzes chitin and chitotrioside substrates. It is specifically expressed by activating macrophages and seems to play a role in the defense against chitinous human pathogens. Recently it has been shown that chitotriosidase may also attend to the inflammatory process. The aim of the study was to determine chitotriosidase activity in serum of patients with lung cancer and patients with inflammatory exudate. We studied the usefulness of the above parameter determination in differentiation between lung cancer and inflammation. In addition, serum activity of lysozyme and cathepsin H was determined.

MATERIALS AND METHODS

The study included 17 patients with inflammatory pleural exudate--group 1., 40 lung cancer patients with malignant pleural effusion--group 2. and 37 healthy subjects. All the patients of group 2. were divided into 2 subgroups: 2A without metastases (n = 23) and 2B with metastases (n = 17). Chitotriosidase and cathepsin H activity was determined in serum by a fluorometric methods. Serum lysozyme activity was measured by turbidimetric method with Micrococcus luteus as substrate.

RESULTS

We observed an increase of the chitotriosidase activity in serum patients of both studied group in comparison with the control. The activity of the chitotriosidase in lung cancer patients was significantly higher than in the control (36.7 vs 68.1 nmol/ml/h; p < 0.01). There were no significant differences in serum lysozyme and cathepsin H activity in patients in comparison to healthy subjects.

CONCLUSION

The results suggest that activity of the chitotriosidase can not be used to differentiation between inflammation and cancer in lung.

[Prognostic significance of lysosomal cysteine proteases in the estimation of the effectiveness of the antitumorigenic therapy]

The influence of the untitumor drugs, cyclophosphamide (CPA) and nitrosomethylurea (NMM) on the activity of lysosomal cysteine proteases cathepsin B and L in the tumor tissue was studied. Regression or reduction in the rate of growth of LS and RLS (drug sensitive and resistant sarcomas, respectively) during injection of CPA or NMM was accompanied by the increase in the activity of cysteine proteases cathepsin B and L in the tumor tissue. The increase of cathepsin B and L activity in the tumor tissue was correlated with the therapeutic effect of the used drugs. Data obtained suggest that cathepsin B and L activity in the tumor tissue have a prognostic significance for the effectiveness of antitumor therapy.

Cathepsin K predicts femoral neck bone mineral density change in nonosteoporotic peri- and early postmenopausal women

OBJECTIVE

Cathepsin K is a cysteine protease that plays an essential role in organic bone matrix degradation. The aim of our study was to seek correlation of serum cathepsin K levels and a change in bone mineral density (BMD) over a 3-year period in a population of healthy nonosteoporotic women. The secondary end points were the correlations of serum cathepsin K with cross-sectional BMD and with other serum bone turnover markers and age.

DESIGN

In 43 healthy women aged 42 to 57 years, blood samples for determination of cathepsin K, osteocalcin, bone alkaline phosphatase, C-terminal cross-linking telopeptide of type I collagen, osteoprotegerin, and nuclear factor kappaB ligand were collected at the time of the first BMD measurement. BMD measurements were repeated after 3 years.

RESULTS

We found a moderate negative correlation of serum cathepsin K levels with change in femoral neck BMD, but none with change in spinal BMD. There were no significant correlations between cross-sectional BMD of the spine or femoral neck and serum levels of cathepsin K. Serum levels of cathepsin K were not significantly correlated with any bone turnover markers studied or with age.

CONCLUSIONS

Serum cathepsin K does not seem to represent a surrogate for bone turnover markers used at present, but it might be useful as a predictor of cortical bone loss.

High cathepsin K levels in men with differentiated thyroid cancer on suppressive L-thyroxine therapy

BACKGROUND

Thyroid hormone administration is associated with low bone density in some studies. The aim of the present study was to evaluate the influence L-thyroxine, in doses used to treat patients with a history of thyroid carcinoma, on serum cathepsin K and other markers of bone metabolism. Cathepsin K is thought to have a role in osteoclast mediated bone resorption.

METHODS

A group of male patients with differentiated thyroid cancer (DTC) on suppressive L-thyroxine therapy (DTC-group; n = 51; mean age 57 years; TSH < 0.1 mU/L) was selected as a model for hyperthyroidism. The results were compared to a group of healthy euthyroid men (control-group; n = 50; mean age 58 years; TSH 1.5 +/- 0.9 mU/L).

RESULTS

In the DTC-group the median value of cathepsin K was 6.9 pmol/L, in the control group 4.8 pmol/L (p = 0.0052; highly significant [h.s.]). There was a significant negative correlation of cathepsin K with age (r = -0.279, p = 0.028). The analysis of various bone associated parameters revealed an increase of serum crosslaps in the DTC-group versus euthyroid controls (p = 0.03). A significant correlation could be found for cathepsin K and osteoprotegerin (p = 0.002).

CONCLUSION

Cathepsin K is increased by a suppressive L-thyroxine therapy and decreases with increasing age. The increased cathepsin K levels seen in DTC-patients on suppressive L-thyroxine therapy are likely to contribute to accelerated bone degradation in these patients.

Circulating cathepsin K and cystatin C in patients with cancer related bone disease: clinical and therapeutic implications

The clinical significance of serum cathepsin K and cystatin C was assessed in patients with breast cancer (BCa) or prostate cancer (PCa) with confined disease (M0) or bone metastasis (BM). Cathepsin K and cystatin C circulating levels were determined by ELISAs in 63 cancer patients, in 35 patients with nonmalignant diseases and in 42 healthy blood donors (control group). In BCa patients, cathepsin K serum levels were significantly lower than in sex matched control group (HS; p=0.0008) or in patients with primary osteoporosis (OP; p=0.0009). On the contrary, cystatin C levels were significantly higher in BCa patients than in HS (p=0.0001) or OP (p=0.017). In PCa patients, cathepsin K concentrations did not significantly differ from those measured in sex matched HS or in patients with benign prostatic hyperplasia (BPH). Conversely, cystatin C was more elevated in cancer patients than in controls (p=0.0001) or BPH patients (p=0.0078). Furthermore, in PCa patients, a positive correlation was observed between cystatin C and cathepsin K (r(S)=0.34; p=0.047). No further relationship was highlighted between these molecules and the clinicobiological parameters of BCa or PCa progression including the number of bone lesions. Moreover, ROC curve analysis showed a poor diagnostic performance of cathepsin K and cystatin C in the detection of BM patients. Interestingly, the administration of zoledronic acid (ZA), a bisphosphonate derivative endowed with a potent antiosteoclastic activity, induced in BM patients a marked increase of cathepsin K and cystatin C serum levels compared to baseline values. However, this phenomenon was statistically significant only in the PCa group. In conclusion Cystatin C and cathepsin K may be regarded as possible markers to monitor the therapeutic response to bisphosphonate treatments. Nevertheless, their clinical value as specific gauges of skeletal metastasis remains questionable.

Study of leukocytic hydrolytic enzymes in patients with acute stage of coronary heart disease

BACKGROUND

Coronary heart disease (CHD) is a major killer worldwide. Atherosclerosis, which is the basis of CHD, is believed to be an inflammatory disorder. Though various aspects of atherosclerosis are extensively studied, leukocytic hydrolytic enzymes are not studied very well with respect to CHD.

AIM

This study was planned to assess changes associated with leukocytic hydrolases in CHD patients.

SETTING AND DESIGN

A tertiary care hospital; case-control study.

MATERIALS AND METHODS

106 patients with acute myocardial infarction, 60 patients with unstable angina and 45 healthy controls were included in the study. Acid phosphatase, lysozyme, adenosine deaminase (ADA) and cathepsin-G levels were estimated from leukocytes. Reduced glutathione (GSH) and malondialdehyde (MDA) levels were measured.

STATISTICAL ANALYSIS

Statistical comparison of data was done using student's t-test (unpaired). Correlation difference was calculated by using Pearson correlation coefficient.

RESULTS

Significantly higher levels of acid phosphatase, lysozyme, ADA with lower levels of cathepsin G in leukocytes were observed in CHD group. We also found significantly higher levels of serum MDA with lower concentrations of blood GSH in CHD group. In diabetic CHD group, significantly higher levels of leukocytic acid phosphatase, lysozyme, ADA and serum MDA with lower levels of cathepsin G and blood GSH were observed.

CONCLUSIONS

Our study indicates that leukocyte hydrolytic enzymes, mainly acid phosphatase, lysozyme and ADA were more active in CHD patients and may contribute to inflammation related with CHD. Its also indicates that leukocyte cathepsin-G may have antiinflammatory role.

Modulation of hypotensive effects of kinins by cathepsin K

Kinins are pro-inflammatory peptides, which participate in the maintenance of cardiovascular homeostasis, and play a key role in numerous diseases, including lung fibrosis and hypertension. Evidence has been provided recently for the presence of alternative mechanisms of bradykinin generation and/or degradation. Here we showed that cathepsin K may act as a potent kinin-degrading enzyme in bloodstream. Contrary to cathepsin L, cathepsin K attenuates kallikrein-induced decrease of rat blood pressure, and reduces the hypotensive effect of bradykinin in a dose-dependent manner. Moreover, we identified, by engineering the S2 subsite of both recombinant enzymes, two critical residues involved respectively in the kininase activity of cathepsin K, i.e. Tyr67/Leu205, versus kininogenase activity of cathepsin L, i.e. Leu67/Ala205. In conclusion, according to its ability to modulate hypotensive effects of kinins, we propose that cathepsin K is a kininase of biological relevance, in complement of well-documented neutral endopeptidase or angiotensin-converting enzyme.

Stress-induced enhancement of activity of lymphocyte lysosomal enzymes in pigs of different stress-susceptibility

To evaluate a possible mechanism of stress-induced lymphopenic effect we assessed the activity of lymphocyte lysosomal enzymes (LE) under immobilization. The effects of immobilization stress on LE (AP, acid phosphatase, cathepsin D and L, beta-N-acetyl-glucosamidase) activity in lymphocytes, number of lymphocytes and plasma cortisol (COR) level in the peripheral blood were examined in the cross-bred Pietrain pigs showing genotypic (presence or lack of RyR1 gene mutation) and phenotypic (reactivity to halothane) differences. It was found that immobilization stress evoked an increase in LE which was concomitant with lymphopenia and a rise of COR level. The most pronounced enhancement of LE, which may reflect a tendency to lymphocyte cytolysis, was found in the recessive homozygotes RyR1 (nn) phenotypically defined as stress/halothane susceptible as well as in the heterozygotes RyR1 (Nn) included in the group of stress/halothane resistant. Despite this individual variability the stress-induced increase in LE activity was present in all the animals. It seems that a possibility of destruction (lysis) of lymphocyte cells should not be excluded as one of the causes of stress lymphopenia.

[Current and future biochemical markers for Gaucher disease]

The biochemical markers secreted by Gaucher's cells are numerous, but none of those identified to date has offered all the expected qualities of a biomarker. Chitotriosidase and chemokine CCL18 are the most useful markers to follow enzyme replacement therapy. The identification of new biomarkers in the near future should enable a clearer understanding of the pathophysiology of this complex disease, which involves numerous cell processes.

Weight loss reduces adipose tissue cathepsin S and its circulating levels in morbidly obese women

CONTEXT

Human adipose tissue produces several adipokines, including the newly identified protein cathepsin S (CTSS), a cysteine protease involved in the pathogenesis of atherosclerosis. Obesity is characterized by high levels of CTSS in the circulation and in sc white adipose tissue (scWAT).

OBJECTIVE

We investigated the effect of surgery-induced weight loss on circulating CTSS and its protein expression in scWAT.

DESIGN

Fifty morbidly obese women before and 3 months after surgery and 10 healthy lean women were studied. We analyzed the relationships between circulating CTSS and clinical and biological parameters. Immunohistochemistry of the CTSS protein variations in scWAT was performed.

RESULTS

Weight loss decreased by 42% (P < 0.0001) the circulating CTSS levels, which correlated with changes in body weight (P = 0.03). We observed a significant decrease in CTSS enzymatic activity by 25% after weight loss (P = 0.001). Adipose tissue CTSS content was reduced by 30% (P = 0.002) after surgery. The variations in CTSS expression in scWAT after surgery correlated with changes in circulating CTSS serum levels (P = 0.03). Most of the correlations between CTSS and clinical and biological parameters disappeared after adjustment for body mass index, emphasizing the strong link between CTSS and corpulence in humans.

CONCLUSIONS

Changes in CTSS scWAT might contribute to serum variations in CTSS during weight loss. The decrease in CTSS concentrations in the circulation may contribute to vascular improvement in obese subjects after weight loss.

An enzyme-linked immunosorbent assay for human cathepsin X, a potential new inflammatory marker

The human lysosomal cysteine-type carboxypeptidase cathepsin X is mainly present in monocytes and macrophages and may be released into the circulation due to constitutive and/or regulated secretion by (activated) immune cells. To define its potential diagnostic value as an inflammatory marker, we have developed a highly sensitive and specific sandwich-type immunoassay (ELISA) for cathepsin X permitting both intra- and extracellular detection and quantification. The dynamic range of the cathepsin X ELISA was determined to be 100 (detection limit) to 8000 pg/ml. Reproducibility of both within and between runs yielded coefficients of variation (CVs) of 2.7-3.5% and 6.3-7.3%, respectively. Cross-reactivity with other members (cathepsin B, L) of the thiol-dependent cathepsin family was not observed. The ELISA was used to quantify cathepsin X in leukocytes as well as in plasma of healthy volunteers and patients with multiple trauma. During the first 72 h after trauma, plasma levels of cathepsin X increased significantly, particularly in patients who died during the posttraumatic period. In comparison to the well-known inflammation marker neutrophil elastase, cathepsin X levels predicted survival with a higher significance in the later posttraumatic phase. In conclusion, this report provides the first evidence of cathepsin X immunoreactivity not only in cell lysates but also in plasma samples. We suggest that the newly developed highly reproducible ELISA will be of great value for further evaluation of this protease as a diagnostic and/or prognostic marker in inflammatory diseases.

Serum cathepsin K concentrations reflect osteoclastic activity in women with postmenopausal osteoporosis and patients with Paget's disease

INTRODUCTION

Cathepsin K, a cysteine protease, plays an essential role in osteoclast-mediated collagen degradation. Recently, an immunoassay to quantify cathepsin K in serum has been developed. We assessed the usefulness of serum cathepsin K as a marker of bone turnover in cross-sectional and longitudinal studies of patients with metabolic bone disease.

METHODS

The study cohort consisted of 40 healthy subjects, 21 women with postmenopausal osteoporosis [66.1 +/- 7.9 yrs] and 10 patients with Paget's disease of bone [67.1 +/- 11.6 yrs]. All patients were started on oral or intravenous bisphosphonate treatment and were followed prospectively over 6 months. Circulating cathepsin K levels were determined by a specific sandwich enzyme immunoassay (Biomedica, Vienna, Austria). In addition, serum carboxyterminal cross-linked telopeptide of type I collagen (betaCTX-I) and bone-specific alkaline phosphatase (BALP) were measured for comparison.

RESULTS

When compared to healthy subjects, mean serum cathepsin K levels were significantly elevated in women with postmenopausal osteoporosis (3.1 +/- 1.9 vs. 11.3 +/- 13.1 pmol/L, p = 0.01) and in patients with Paget's disease of bone (6.2 +/- 4.4 pmol/L, p = 0.04). In postmenopausal osteoporotic women, both oral and intravenous bisphosphonate treatment resulted in a significant reduction in serum cathepsin K levels (p = 0.03) with most of the effect occurring after one month (mean% change: -33%). In patients with mild Paget's disease, serum cathepsin K levels decreased during bisphosphonate treatment.

CONCLUSIONS

Serum concentrations of cathepsin K appear to reflect osteoclastic activity in patients with postmenopausal osteoporosis and Paget's disease of bone and may hold promise as a marker of osteoclast activity.

Evaluation of immunoglobulin G subclass antibodies against recombinant Fasciola gigantica cathepsin L1 in an enzyme-linked immunosorbent assay for serodiagnosis of human fasciolosis

A cystatin capture enzyme-linked immunosorbent assay (ELISA) using recombinant Fasciola gigantica cathepsin L1 antigen was developed to detect specific immunoglobulin G (IgG) subclass antibodies (IgG1, IgG2, IgG3, and IgG4) and was evaluated for its diagnostic potential for human fasciolosis. In an analysis of the sera of 13 patients infected with F. gigantica, 209 patients with other parasitic infections, 32 cholangiocarcinoma patients, and 42 healthy controls, the IgG4-ELISA gave the highest diagnostic values. The sensitivity, specificity, accuracy, and positive and negative predictive values of this method based on the detection of IgG4 antibody were 100%, 99.3%, 99.3%, 86.7%, and 100%, respectively. The results revealed that restricting the ELISA to the detection of specific IgG4 antibody enhanced the specificity and accuracy for the serodiagnosis of human fasciolosis.

Quantum proteolytic activation of chemokine CCL15 by neutrophil granulocytes modulates mononuclear cell adhesiveness

Monocyte infiltration into inflammatory sites is generally preceded by neutrophils. We show here that neutrophils may support this process by activation of CCL15, a human chemokine circulating in blood plasma. Neutrophils were found to release CCL15 proteolytic activity in the course of hemofiltration of blood from renal insufficiency patients. Processing of CCL15 immunoreactivity (IR) in the pericellular space is suggested by a lack of proteolytic activity in blood and blood filtrate, but a shift of the retention time (t(R)) of CCL15-IR, detected by chromatographic separation of CCL15-IR in blood and hemofiltrate. CCL15 molecules with N-terminal deletions of 23 (delta23) and 26 (delta26) aa were identified as main proteolytic products in hemofiltrate. Neutrophil cathepsin G was identified as the principal protease to produce delta23 and delta26 CCL15. Also, elastase displays CCL15 proteolytic activity and produces a delta21 isoform. Compared with full-length CCL15, delta23 and delta26 isoforms displayed a significantly increased potency to induce calcium fluxes and chemotactic activity on monocytes and to induce adhesiveness of mononuclear cells to fibronectin. Thus, our findings indicate that activation of monocytes by neutrophils is at least in part induced by quantum proteolytic processing of circulating or endothelium-bound CCL15 by neutrophil cathepsin G.

Potent epitopes derived from Fasciola gigantica cathepsin L1 in peptide-based immunoassay for the serodiagnosis of human fascioliasis

A peptide-based enzyme-linked immunosorbent assay (ELISA) was developed and evaluated for its diagnostic ability to detect human IgG antibodies against Fasciola gigantica cathepsin L1. Two previously identified B-cell epitopes of cathepsin L1 were synthesized as single synthetic peptides (acetyl-DKIDWRESGYVTEVKDQGNC-carboxamide and acetyl-DKIDWRESGYVTELKDQGNC-carboxamide) and their diagnostic potential was evaluated. The peptide-based ELISA was compared with an indirect ELISA with crude excretory-secretory products or with partially purified specific 27-kDa (FG27) antigen from adult F. gigantica. In an analysis of the sera of 13 patients infected with F. gigantica, 212 patients with other parasitic infections, 32 patients with cholangiocarcinoma, and 57 healthy controls, the sensitivity, specificity, accuracy, and positive and negative predictive values of this peptide-based ELISA with both peptides had the same performance and were shown to be 100%, 97.3%, 97.5%, 61.9%, and 100%, respectively. When 4 different ELISAs were compared, the results revealed that the specificity, sensitivity, accuracy, and negative predictive values of all antigens were similar except for the positive predictive value that was highest in the ELISA with the FG27 antigen. These results demonstrated that peptide antigens can be used in the serodiagnosis of human fascioliasis with the additional advantage that they are relatively cheap and easy to produce. This rapid, highly sensitive and specific peptide-ELISA has the potential to be used in future large-scale prevalence surveys throughout Southeast Asia.

Increased serum cathepsin S in patients with atherosclerosis and diabetes

Atherosclerosis and diabetes are closely associated and both involve extensive degradation of the aortic elastin. Increased elastase activity has been detected in diabetic animal aortae. We have demonstrated enhanced elastolytic cathepsin S in human atherosclerotic lesions but insufficient amounts of its endogenous inhibitor cystatin C, suggesting alterations of serum cathepsin S and/or cystatin C in patients with atherosclerosis or diabetes. In this study, we measured levels of both cathepsin S and cystatin C in sera from 240 patients by ELISA. Among these patients, 107 had a diagnosis of atherosclerotic stenosis, 103 were diabetic, and 30 had neither condition. Multiple linear regression analysis demonstrated that significantly higher serum levels of cathepsin S in patients with either atherosclerotic stenosis (p<0.04) or diabetes (p=0.0005) persisted after adjustment for cystatin C level, renal function, smoking, and serum glucose levels (p=0.008, p=0.0005). Furthermore, patients with acute (p=0.009) or previous myocardial infarction (p<0.02) or unstable angina pectoris (p<0.05) had elevated levels of cathepsin S after adjustment for smoking, creatinine, cystatin C, and serum glucose. In contrast, serum cystatin C levels were higher in diabetic patients (p=0.00001), but not in atherosclerotic subjects (p=0.14), than in the non-involved population after adjustment for age, smoking, and renal function. Although the pathophysiology of cathepsin S or cystatin C in atherosclerosis and diabetes requires further investigation, increased serum cathepsin S may serve as a biomarker for both diseases.

Effect of ghrelin on activities of some lysosomal hydrolases in rabbits

OBJECTIVES

Observing the changes of activity of some lysosomal enzymes in blood serum of female rabbits subjected to injection of 10 microg of ghrelin/kg of body weight.

METHODS

In the blood serum the activity of cathepsins D and L, alanine aminopeptidase, acid phosphatase, lysosomal lipase and lysosomal esterase was determined.

RESULTS

As a result of ghrelin injection the activity of all the enzymes examined in blood serum increased markedly.

CONCLUSION

Changes of lysosomal enzymes activities in the blood serum caused by the effects of ghrelin should be regarded as the response of the lysosomal system.

Soluble cathepsin K: A novel marker for the prediction of nontraumatic fractures?

We sought to evaluate serum concentrations of cathepsin K in peripheral blood and to determine whether they correlated with bone-mineral density (BMD) and the incidence of nontraumatic fractures. We took blood samples from 162 patients (101 with osteoporosis, 48 with osteopenia) and 13 healthy controls, then conducted quantitative measurements of cathepsin K using a commercially available enzyme-linked immunosorbent assay. Cathepsin K concentrations were correlated with the incidence of nontraumatic fracture, BMD, markers of bone turnover (alkaline phosphatase, bone-specific alkaline phosphatase, osteocalcin, parathyroid hormone, and C-telopeptide). The correlations between cathepsin K concentrations in subjects without fractures and in those with multiple nontraumatic fractures were statistically significant ( t = -2.1, degrees of freedom = 107, P = .036). The cathepsin K levels of controls and patients with osteoporosis were significantly different ( t = -3.7, degrees of freedom = 58.9, p>0.0001) These results suggest that the serum level of cathepsin K could serve as a marker for fracture prediction and BMD.

Cathepsin S, a novel biomarker of adiposity: relevance to atherogenesis

The molecular mechanisms by which obesity increases the risk of cardiovascular diseases are poorly understood. The purpose of this study was to identify candidate biomarkers overexpressed in adipose tissue of obese subjects that could link expanded fat mass to atherosclerosis. We compared gene expression profile in subcutaneous adipose tissue (scWAT) of 28 obese and 11 lean subjects using microarray technology. This analysis identified 240 genes significantly overexpressed in scWAT of obese subjects. The genes were then ranked according to the correlation between gene expression and body mass index (BMI). In this list, the elastolytic cysteine protease cathepsin S was among the highly correlated genes. RT-PCR and Western blotting confirmed the increase in cathepsin S mRNA (P=0.006) and protein (P<0.05) in obese scWAT. The circulating concentrations of cathepsin S were also significantly higher in obese than in nonobese subjects (P<0.0001). Both cathepsin S mRNA in scWAT and circulating levels were positively correlated with BMI, body fat, and plasma triglyceride levels. In addition, we show that the proinflammatory factors, lipopolysaccharide, interleukin-1beta, and tumor necrosis factor-alpha increase cathepsin S secretion in human scWAT explants. This study identifies cathepsin S as a novel marker of adiposity. Since this enzyme has been implicated in the development of atherosclerotic lesions, we propose that cathepsin S represents a molecular link between obesity and atherosclerosis.

Serum levels of cathepsin K decrease with age in both women and men

Bone turnover increases with age. In a previous study, we reported on bone metabolism in young and elderly women and men. The aim of the present investigation was to evaluate potential age- and gender-related changes in cathepsin K, a cysteine protease that plays an important role in the degradation of the organic matrix of bone. Twenty-five healthy premenopausal women, 24 young healthy men, 26 elderly women, and 25 elderly men participated in the study. Elderly women and men had significantly lower cathepsin K levels than younger ones. In both men and women, serum levels of cathepsin K were negatively correlated with age. In men there was a statistically significant negative correlation between serum levels of cathepsin K and osteoprotegerin, which inhibits osteoclast differentiation and activation. No association was found between serum levels of cathepsin K and bone-specific alkaline phosphatase, osteocalcin, or 25-hydroxy vitamin D. Thus, the age-related increase in OPG, which markedly inhibits the expression of cathepsin K, may also reduce serum levels of cathepsin K. Despite the age-related increase in bone resorption, this study shows lower cathepsin K values in elderly women and men than in younger subjects. It might be speculated that a different enzyme could compensate for the decline in cathepsin K during old age.

Differential turnover of cortical and trabecular bone in transgenic mice overexpressing cathepsin K

Cathepsin K is a major osteoclastic protease. We have recently shown that overexpression of mouse cathepsin K gene in transgenic UTU17 mouse model results in high turnover osteopenia of metaphyseal trabecular bone at the age of 7 months. The present report extends these studies to a systematic analysis of cortical bone in growing and adult mice overexpressing cathepsin K. Mice homozygous for the transgene locus (UTU17+/+) and their control littermates were studied at the age of 1, 3, 7, and 12 months. Bone properties were analyzed using peripheral quantitative computed tomography (pQCT), histomorphometry, histochemistry, radiography, and biomechanical testing. In addition, the levels of biochemical markers of bone turnover were measured in the sera. Unexpectedly, cortical thickness and cortical bone mineral density were increased in the diaphyseal region of growing and adult UTU17+/+ mice. This was associated with an increased number of vascular canals leading to increased cortical porosity in UTU17+/+ mice without changes in the ultimate bending force or stiffness of the bone. In UTU17+/+ mice, osteopenia of metaphyseal trabecular bone was observed already at the age of 1 month. In sera of 1-month-old UTU17+/+ mice, the activity of tartrate-resistant acid phosphatase 5b was decreased and the levels of osteocalcin increased. Our results support the role of cathepsin K as a major proteinase in osteoclastic bone resorption. Excessive production of cathepsin K induced osteopenia of metaphyseal trabecular bone and increased the porosity of diaphyseal cortical bone. The increased cortical thickness and bone mineral density observed in diaphyses of UTU17+/+ mice demonstrate the different nature and reactivity of trabecular and cortical bone in mice. These results suggest that the biomechanical properties of cortical bone are preserved through adaptation as outlined in Wolff's law.

Role of cathepsins and cystatins in patients with recurrent miscarriage

In the implantation, trophoblasts penetrate maternal decidua by secreting proteases. It has been reported that cathepsins are highly expressed in the mouse villi, and play an important role in normal embryonal growth and decidualization. In this study, we evaluated cathepsins and their endogenous inhibitors, cystatins, in tissue and serum of patients with recurrent miscarriage. Decidua and villi were surgically collected from 22 patients and 12 healthy women. Immunohistochemistry was performed with antibodies against cathepsins, stefin A (cystatin A), stefin B (cystatin B) and cystatin C. The concentrations of cathepsins, stefins and cystatin C were measured by Enzyme-linked immunosorbent assay. In addition, we measured the serum level of cystatin C in 85 Japanese women with recurrent miscarriage. Staining of cathepsin B, D, H, L, stefin B and cystatin C was observed in the cytoplasm of epithelial cells in decidua. Stefin A was expressed on the surface of the trophoblast. The concentration of cathepsin B and H in patients' decidua was significantly higher than in control individuals. The serum level of cystatin C was significantly lower in patients than in control individuals. Our findings suggest that the regulation of the cathepsin-cystatin system may play an important role in patients with recurrent miscarriage.

Activity of enzymes with different subcellular localization in the blood plasma of patients with aortic aneurysm

BACKGROUND

The wall of an abdominal aorta aneurysm shows increased activity of metalloproteinases, aspartyl cathepsins and cystein cathepsins, and decreased activity of inhibitors of these enzymes, as compared to the wall of a normal aorta. Parietal thrombi of the aneurysm also show marked proteolytic activity. The aim of our study was to determine the activity of secretory enzymes, membrane enzymes, cytosol enzymes, mitochondrial enzymes and lysosomal enzymes in the blood plasma of patients with abdominal aortic aneurysm.

MATERIAL/METHODS

Blood for examinations was collected from 15 patients with abdominal aorta aneurysm without coexisting diseases, and from the same number of healthy subjects, to determine the activity of lactic acid dehydrogenase (LDH), 5' nucleotidase (5'NT), gamma-glutamyltranspeptidase (GGTP) and cholinesterase (ChE), alanine aminotransferase (ALT), aspartic aminotransferase (AST), cathepsin B (CB), cathepsin D (CD), and cathepsin L (CL).

RESULTS

The plasma activity of ALT, AST and GGTP in the blood of patients with aortic aneurysm is lower than in the plasma of healthy subjects. The activity of LDH, 5'NT and ChE, CB and CL does not significantly differ in the plasma of patients with aortic aneurysm compared to the plasma of healthy subjects. The activity of CD is increased in the plasma of patients with aortic aneurysm.

CONCLUSIONS

Determination of cathepsin D activity may be helpful in the diagnosis of aortic aneurysm.

Papillon-Lefèvre syndrome: correlating the molecular, cellular, and clinical consequences of cathepsin C/dipeptidyl peptidase I deficiency in humans

A variety of neutral serine proteases are important for the effector functions of immune cells. The neutrophil-derived serine proteases cathepsin G and neutrophil elastase are implicated in the host defense against invading bacterial and fungal pathogens. Likewise, the cytotoxic lymphocyte and NK cell granule-associated granzymes A and B are important for the elimination of virus-infected cells. The activation of many of these serine proteases depends on the N-terminal processing activity of the lysosomal cysteine protease cathepsin C/dipeptidyl peptidase I (DPPI). Although mice deficient in DPPI have defects in serine protease activation in multiple cellular compartments, the role of DPPI for human serine protease activation is largely undefined. Papillon-Lefevre syndrome (PLS) is a rare autosomal recessive disease associated with loss-of-function mutations in the DPPI gene locus. In this study, we established that the loss of DPPI activity is associated with severe reduction in the activity and stability of neutrophil-derived serine proteases. Surprisingly, patients with PLS retain significant granzyme activities in a cytotoxic lymphocyte compartment (lymphokine-activated killer) and have normal lymphokine-activated killer-mediated cytotoxicity against K562 cells. Neutrophils from patients with PLS do not uniformly have a defect in their ability to kill Staphylococcus aureus and Escherichia coli, suggesting that serine proteases do not represent the major mechanism used by human neutrophils for killing common bacteria. Therefore, this study defines the consequences of DPPI deficiency for the activation of several immune cell serine proteases in humans, and provides a molecular explanation for the lack of a generalized T cell immunodeficiency phenotype in patients with PLS.

[The influence of occupational exposure to arsenic and heavy metals on the activity of catepsins and their inhibitors in blood serum of copper smelters]

BACKGROUND

Exposure to arsenic, lead, and cadmium poses the risk of cancer. Cathepsins (CP) and their natural inhibitors (CPI) in blood serum are markers of carcinogensis. The aim of this work was to verify the existence of relationships between the exposure to the airesaid elements and the activity of CP and CPL.

MATERIALS AND METHODS

The levels of Pb and Cd in blood, Mn, Cu, Zn, Ca, Mg, Fe, Se CP as well as free and bound CPI in serum, FEP in erythrocytes, and As in urine were measured in 186 production workers of Legnica Copper Smelter (study group) and 56 administrative employees (control group) and then analyzed.

RESULTS

CF levels were significantly elevated in both groups and CPI levels were elevated in the study group vs. the control group. There were no statistically significant relationships between CF and CPI levels and the remaining parameters in the study group. whereas they were found for CPI in the control group. The results indicate that occupational and environmental exposures to toxic metals (arsenic, lead, cadmium) may lead to the elevated levels of CF and CPI.

CONCLUSIONS

The obtained results support the assumptions of the study.

Prognostic and predictive value of cathepsins D and L in operable breast cancer patients

None of the established prognostic factors in breast cancer (BC) is able to determine the final outcome with certainity. Tumor biological factors involved in tumor invasion and metastasis, such as cathepsins and proteins of u-PA system, have been put forward in the recent literature as strong novel prognostic factors in BC. We therefore evaluated prognostic and predictive value of cathepsin-D (CD) and cathepsin-L (CL) in 715 operable BC patients. CD and CL were determined in tumor extracts using immunoradiometric and ELISA assays, respectively. During follow-up (median 37 months), 151 (21%) patients relapsed. In a multivariate analysis of disease-free survival (DFS), CL (p=0.04), nodal status (p<0.001) and hormone receptor status (p<0.001) were the only independent significant prognostic factors. CL thus provided independent prognostic information on DFS and could also predict a response to adjuvant chemotherapy (ChT), while CD had no significant prognostic and predictive impact.