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.

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.

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.

α-Defensins Induce a Post-translational Modification of Low Density Lipoprotein (LDL) That Promotes Atherosclerosis at Normal Levels of Plasma Cholesterol.

Approximately one-half of the patients who develop clinical atherosclerosis have normal or only modest elevations in plasma lipids, indicating that additional mechanisms contribute to pathogenesis. In view of increasing evidence that inflammation contributes to atherogenesis, we studied the effect of human neutrophil α-defensins on low density lipoprotein (LDL) trafficking, metabolism, vascular deposition, and atherogenesis using transgenic mice expressing human α-defensins in their polymorphonuclear leukocytes (Def(+/+)). Accelerated Def(+/+) mice developed α-defensin·LDL complexes that accelerate the clearance of LDL from the circulation accompanied by enhanced vascular deposition and retention of LDL, induction of endothelial cathepsins, increased endothelial permeability to LDL, and the development of lipid streaks in the aortic roots when fed a regular diet and at normal plasma levels of LDL. Transplantation of bone marrow from Def(+/+) to WT mice increased LDL clearance, increased vascular permeability, and increased vascular deposition of LDL, whereas transplantation of WT bone marrow to Def(+/+) mice prevented these outcomes. The same outcome was obtained by treating Def(+/+) mice with colchicine to inhibit the release of α-defensins. These studies identify a potential new link between inflammation and the development of atherosclerosis.

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.

Long-term endurance training increases serum cathepsin S and decreases IL-6 and hsCRP levels.

Cathepsin S (CS) was shown to play a key role in cancer progression, atherosclerosis, heart valve disease, insulin resistance and diabetes mellitus. The present prospective study aimed to investigate the influence of sports on CS, interleukin-6 (Il-6) and high-sensitivity C-reactive protein (hsCRP) levels. Ninety-eight of 109 participants completed the study. Ergometries were performed at baseline and after 8 months to evaluate/quantify the performance gain. Blood samples were taken at baseline and every 2 months. CS was measured by ELISA (enzyme-linked immunosorbent assay). Compared to the control group (mean performance gain -3.41 ± 4.62%) we observed a significant physical-activity-induced increase of CS levels (3.45-3.73 ng · ml-1; P = 0.027) and a significant decrease of Il-6 (2.43-1.91 pg · ml-1; P = 0.031) and hsCRP-levels (0.11-0.09 mg · dl-1; P = 0.001) in the intervention group (mean performance gain: 12.13 ± 6.32%). Furthermore, the tendency of the progression was significant for CS and Il-6 (P = 0.002/0.033). We could show a significant sports-induced decrease of the classic inflammation parameters hsCRP/Il-6, probably expressing a downregulation of permanently prevalent inflammation processes. Simultaneously CS levels increased significantly. Our results show that increasing CS amounts are not simply to equal with an enhanced inflammation status and might even have beneficial effects on inflammation and angiogenesis.

[Oxidative carbonylation of proteins in experimental hind-limb ischaemia-reperfusion injury]. / Okislitel'noe karbonilirovanie belkov pri éksperimental'noi ishemii i reperfuzii nizhnikh konechnostei.

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.

Plasma levels of adipokines in systemic lupus erythematosus patients.

OBJECTIVE: To evaluate the plasma levels of six adipokines, including chemerin, omentin-1, lipocalin-2, cathepsin-S, cathepsin-L and adipsin, in patients with SLE. METHODS: Ninety SLE patients and ninety control subjects were recruited, plasma adipokines levels were measured by enzyme-linked immunosorbent assay, and their associations with major clinical and laboratory indexes were analyzed. RESULTS: There were no significant differences in plasma chemerin, omentin-1, lipocalin-2, cathepsin-S, cathepsin-L and adipsin levels between SLE patients and controls. Further subgroup analyses by major clinical and laboratory indexes showed that plasma omentin-1 level was significantly lower in SLE patients without nephritis when compared with those patients with nephritis (P=0.002). Plasma chemerin, cathepsin-S levels in SLE patients without nervous system disorder were significantly lower in comparison with SLE patients with nervous system disorder (P=0.035, P=0.029). No significant associations of other adipokines with any major clinical and laboratory indexes were observed. CONCLUSIONS: Plasma levels of chemerin, omentin-1, lipocalin-2, cathepsin-S, cathepsin-L and adipsin in SLE patients were not markedly different from the normal controls. The presence of nephritis was connected with higher plasma omentin-1 levels in SLE patients, and the presence of nervous system disorder was associated with higher plasma chemerin, cathepsin-S levels in SLE patients. However, functional studies are awaited to further explore the potential roles of these cytokines in SLE.

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.

Soluble Glycoprotein 130 and Heat Shock Protein 27 as Novel Candidate Biomarkers of Chronic Heart Failure with Preserved Ejection Fraction.

BACKGROUND: Despite their importance, the current clinical biomarkers of chronic heart failure have limitations. In this study, soluble glycoprotein 130 (sgp130), heat shock protein 27 (hsp27), dipeptidyl peptidase IV (dpp4) and cathepsin S (CTSS) were tested for their potential as novel biomarkers for diagnosing chronic heart failure (CHF) with preserved ejection fraction. METHODS: We compared the circulating levels of sgp130, hsp27, dpp4, and cathepsin S in patients with CHF with preserved ejection fraction (n=50) and in controls (n=50), determined how well these candidate biomarkers distinguish patients with CHF from controls, and assessed whether these candidates are superior to N-terminal pro brain natriuretic peptide (NT-pro-BNP) as diagnostic tools. RESULTS: After adjusting for clinical covariates, patients with CHF showed significantly higher mean concentrations of sgp130 (317.38pg/ml vs. 215.90 pg/ml), hsp27 (2601.02 pg/ml vs. 923.61 pg/ml) and NT-pro-BNP (982.35 pg/ml vs. 331.99 pg/ml), but not dpp4 (6930.9 4pg/ml vs. 7081.37 pg/ml) or CTSS (1050.46 pg/ml vs. 984.96 pg/ml), than did controls. In the receiver operating characteristic curve analysis, hsp27 showed the most notable difference between CHF patients and controls, with the largest area under the curve (AUC) (0.920); the AUC values for sgp130 and NT-pro-BNP were 0.877 and 0.882, respectively. CONCLUSIONS: Soluble glycoprotein 130 and hsp27 are novel candidate biomarkers for diagnosing CHF with preserved ejection fraction and thus warrant further investigation; neither dpp4 nor CTSS showed promise as biomarkers of CHF.

Risk Factors of Acute Pancreatitis in Oral Double Balloon Enteroscopy.

Double balloon enteroscopy (DBE) was introduced 15 years ago. The complications of diagnostic DBE are rare, acute pancreatitis is most redoubtable one (incidence about 0.3%). Hyperamylasemia after DBE seems to be a rather common condition respectively. The most probable cause seems to be a mechanical straining of the pancreas. We tried to identify patients in a higher risk of acute pancreatitis after DBE. We investigated several laboratory markers before and after DBE (serum cathepsin B, lactoferrin, E-selectin, SPINK 1, procalcitonin, S100 proteins, alfa-1-antitrypsin, hs-CRP, malondialdehyde, serum and urine amylase and serum lipase). Serum amylase and lipase rose significantly with the maximum 4 hours after DBE. Serum cathepsin and procalcitonin decreased significantly 4 hours after DBE compared to healthy controls and patients values before DBE. Either serum amylase or lipase 4 hours after DBE did not correlate with any markers before DBE. There was a trend for an association between the number of push-and-pull cycles and procalcitonin and urine amylase 4 hours after DBE; between procalcitonin and alfa-1-antitrypsin, cathepsin and hs-CRP; and between E-selectin and malondialdehyde 4 hours after DBE. We found no laboratory markers determinative in advance those patients in a higher risk of acute pancreatitis after DBE.

Plasma signature of neurological disease in the monogenetic disorder Niemann-Pick Type C.

Early diagnosis of neurological disorders would greatly improve their management and treatment. A major hurdle is that inflammatory products of cerebral disease are not easily detected in blood. Inflammation in multiple organs and heterogeneity in disease present additional challenges in distinguishing the extent to which a blood-based marker reflects disease in brain or other afflicted organs. Murine models of the monogenetic disorder Niemann-Pick Type C present aggressive forms of cerebral and liver inflammatory disease. Microarray analyses previously revealed age-dependent changes in innate immunity transcripts in the mouse brain. We have now validated four putative secretory inflammatory markers that are also elevated in mouse liver. We include limited, first time analysis of human Niemann-Pick Type C liver and cerebellum. Furthermore, we utilized 2-hydroxypropyl-ß-cyclodextrin (HPßCD, an emerging therapeutic) administered intraperitoneally in mice, which abrogates inflammatory pathology in the liver but has limited effect on the brain. By analyzing the corresponding effects on inflammatory plasma proteins, we identified cathepsin S as a lead indicator of liver disease. In contrast, lysozyme was a marker of both brain and liver disease. 2-Hydroxypropyl-ß-cyclodextrin had no effect on transcripts of neuron-specific 24-hydroxylase, and its product 24(S)-hydroxycholesterol was not a useful indicator in mouse plasma. Our data suggest that dual analysis of levels of the inflammatory markers lysozyme and cathepsin S may enable detection of multiple distinct states of neurodegeneration in plasma.

Cathepsin S and cathepsin L in serum and synovial fluid in rheumatoid arthritis with and without autoantibodies.

OBJECTIVES: Cathepsin S and cathepsin L are endosomal proteolytic enzymes involved in the degradation of extracellular matrixes, angiogenesis and antigen presentation. Cathepsins could thus play several roles in the disease process of RA. The aim of this study was to examine differences in cathepsin S and cathepsin L levels in serum and SF of RA patients with and without ACPA and RF. METHODS: In this study 121 patients with RA and clinical signs of knee synovitis were recruited. Patient characteristics were collected and matched samples of serum and SF were analysed for cathepsin S, cathepsin L, ACPA, IgA and IgM RF, CRP and MMP3. RESULTS: SF levels of cathepsin L, cathepsin S and MMP3 were significantly higher than in serum. Serum levels of both cathepsins were significantly higher in patients with ACPA, IgM-RF and IgA-RF compared with patients without these antibodies. SF levels of both cathepsins correlated with DAS28 and CRP in ACPA- and RF-positive but not in seronegative patients. CONCLUSION: The differences in cathepsin S and cathepsin L between RA patients with and without autoantibodies indicate that these cathepsins have a specific role in the disease process of seropositive RA. In this phenotype, cathepsin serum levels may reflect the autoimmune activity, whereas the levels in SF may reflect the local inflammatory and matrix degrading process in the joint.

Endostatin, Cathepsin S, and Cathepsin L, and Their Association with Inflammatory Markers and Mortality in Patients Undergoing Hemodialysis.

BACKGROUND/AIMS: Although both endostatin and cathepsins S have been associated with higher mortality, data in patients with end-stage renal disease (ESRD) are scarce. METHODS: A longitudinal cohort study of 207 prevalent patients undergoing hemodialysis. RESULTS: Cathepsins S and L were associated with soluble receptors for tumor necrosis factor (sTNFR1 and sTNFR2, rho between 0.28 and 0.43, p < 0.001 for all). Weaker or absent associations between endostatin, cathepsins S and L were seen with other inflammatory biomarkers, that is, CRP, interleukin 6, pentraxin 3, and TNF. In Cox and Laplace regression models adjusted for age, sex, dialysis vintage, and diabetes: standard deviation increments of endostatin was associated with a lower mortality (hazard ratio 0.75, 95% confidence interval (CI) 0.57-0.98), and with 6.8 months longer median survival. CONCLUSIONS: The high levels of endostatin, cathepsins S and L, and their associations with sTNFR1 and sTNFR2 warrant further studies exploring mortality, and the angiogenic and inflammatory pathways in ESRD.

Prognostic and predictive value of cathepsin X in serum from colorectal cancer patients.

BACKGROUND: Cathepsin X is a cysteine protease involved in mechanisms of malignant progression. It is secreted from tumour cells as a proenzyme and may serve to predict the disease status and risk of death for cancer patients. In a previous, pilot, study on 77 colorectal patients we demonstrated the correlation of higher serum levels with shorter overall survival. METHODS: 264 patients with colorectal cancer were included in a prospectively accrued multi-centre observational cohort study with the aim of testing novel biomarkers. Blood samples were collected before preoperative large bowel endoscopy and total cathepsin X was measured in sera by ELISA. As a control group we selected at random 77 subjects who had no findings at endoscopy and reported no co-morbidity. RESULTS: The mean level of cathepsin X in cancer patients did not differ from the control levels (23.4 ng/ml ± 6.4 SD vs. 18.8 ng/ml ± 11.4 SD, p > 0.05) and there was no association with age, gender, disease stage, tumour location or CEA. In univariate analysis no association between cathepsin X levels and overall survival was demonstrated for the entire set of patients, however, cathepsin X was associated with survival in a group of patients with local resectable disease (stages I-III) (HR = 1.69, 95% CI: 1.03-2.75, p = 0.03). For this group, multivariate Cox regression analysis showed an association (HR = 3.13, 95% CI: 1.37-7.18, p = 0.003) between high cathepsin X levels and shorter overall survival for patients who did not receive chemotherapy, whereas, for patients who received chemotherapy, there was no association between cathepsin X and survival (HR = 0.51, 95% CI: 0.20-1.33, p = 0.88). CONCLUSIONS: Association of cathepsin X levels with overall survival was not confirmed for an entire set of 264 colorectal patients, but for patients in stages I-III with local resectable disease. The significant association of cathepsin X with survival in a group of patients who received no chemotherapy and the absence of this association in the group who received chemotherapy, suggest the possible predictive value for response to chemotherapy. The results have to be confirmed in a further prospective study.

Hypothermia slows sequential and parallel steps initiated during caerulein pancreatitis.

BACKGROUND AND OBJECTIVES: Multiple deleterious signaling cascades are simultaneously activated in acute pancreatitis (AP), which may limit the success of pharmacologic approaches targeting a single step. We explored whether cooling acinar cells slows distinct steps initiated from a stimulus causing pancreatitis simultaneously, and the temperature range over which inhibition of such deleterious signaling occurs. METHODS: Caerulein (100 nM) induced trypsinogen activation (TGA), CXCL1, CXCL2 mRNA levels, cell injury were studied at 37 °C, 34 °C, 31 °C, 29 °C and 25 °C in acinar cells. Trypsin, cathepsin B activities and cathepsin B mediated TGA were studied at 37 °C, 23 °C and 4 °C. RESULTS: There was >80% reduction in TGA, CXCL1 and CXCL2 mRNA levels at 29 °C, and in cell injury at 34 °C, compared to those at 37 °C. Trypsin activity, cathepsin B activity and cathepsin B mediated TGA at 23 °C were respectively, 53%, 64% and 26% of that at 37 °C. Acinar cooling to 31 °C reduced LDH leakage even when cooling was initiated an hour after caerulein stimulation at 37 °C. CONCLUSIONS: Hypothermia synergistically and simultaneously slows parallel and distinct signaling steps initiated by caerulein, thereby reducing TGA, upregulation of inflammatory mediators and acinar injury.

Circulating plasma levels of cathepsin S and L are not associated with disease severity in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is characterized by chronic synovitis and articular cartilage destruction. Increased activities of cathepsin S and cathepsin L, two potent cysteine proteases, are thought to play a role in the pathogenesis of the irreversible articular cartilage destruction. Nevertheless, data regarding the potential importance of the cathepsins as circulating biomarkers in RA patients are limited. METHOD: Subjects enrolled in this study are part of a larger study where patients from the three northern counties of Sweden diagnosed with early RA are followed in an ongoing prospective study. In total, 71 patients were included, along with 44 age- and sex-matched control subjects. Plasma levels of cathepsin S and L were analysed. Disease severity was assessed using the 28-joint count Disease Activity Score (DAS28). RESULTS: Plasma levels of cathepsin S and L were significantly increased in patients with RA compared to healthy controls (p < 0.05 for both). However, in the patients with RA, no association between the cathepsins and the severity of the disease, as characterized by DAS28, was observed (p > 0.51). CONCLUSIONS: Although circulating levels of cathepsin S and L were significantly increased in patients with recently diagnosed RA, our data do not support the notion that circulating levels of cathepsins are relevant biomarkers for disease severity.

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 ß = 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.

Influence of a prudent diet on circulating cathepsin S in humans.

BACKGROUND: Increased circulating cathepsin S levels have been linked to increased risk of cardiometabolic diseases and cancer. However, whether cathepsin S is a modifiable risk factor is unclear. We aimed to investigate the effects of a prudent diet on plasma cathepsin S levels in healthy individuals. FINDINGS: Explorative analyses of a randomized study were performed in 88 normal to slightly overweight and hyperlipidemic men and women (aged 25 to 65) that were randomly assigned to ad libitum prudent diet, i.e. healthy Nordic diet (ND) or a control group (habitual Western diet) for 6 weeks. Whereas all foods in the ND were provided, the control group was advised to consume their habitual diet throughout the study. The ND was in line with dietary recommendations, e.g. low in saturated fats, sugars and salt, but high in plant-based foods rich in fibre and unsaturated fats.The ND significantly decreased cathepsin S levels (from 20.1 (+/-4.0 SD) to 19.7 µg/L (+/-4.3 SD)) compared with control group (from 18.2 (+/-2.9 SD) to 19.1 µg/L (+/-3.8 SD)). This difference remained after adjusting for sex and change in insulin sensitivity (P = 0.03), and near significant after adjusting for baseline cathepsin S levels (P = 0.06), but not for change in weight or LDL-C. Changes in cathepsin S levels were directly correlated with change in LDL-C. CONCLUSIONS: Compared with a habitual control diet, a provided ad libitum healthy Nordic diet decreased cathepsin S levels in healthy individuals, possibly mediated by weight loss or lowered LDL-C. These differences between groups in cathepsin S were however not robust and therefore need further investigation.

Determination of cathepsin S abundance and activity in human plasma and implications for clinical investigation.

There is strong experimental evidence associating cathepsin S with the pathogenesis of atherosclerosis, with emerging data to support its role in diseases such as abdominal aortic aneurysm, obesity, and type 2 diabetes. To further our understanding of cathepsin S, we have developed a novel sandwich immunoassay to measure the mature form of cathepsin S in plasma (mean values from 12 healthy donors of 53±17ng/ml, range=39-102). We also developed a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay to measure in vitro cathepsin S activity to compare activity levels with the protein mass levels determined by enzyme-linked immunosorbent assay (ELISA). Interestingly, we observed that only 0.4 to 1.1% of circulating cathepsin S was enzymatically active. We subsequently demonstrated that the attenuated activity we observed resulted from binding between cathepsin S and its endogenous inhibitor cystatin C in plasma. These data were obtained through immunoprecipitation coupled with either Western blotting analysis or in-gel tryptic digestion and LC-MS/MS characterization of Coomassie-stained gel bands. Although many laboratories have explored the relationship between cathepsin S and cystatin C, this is the first study to demonstrate their association in human circulation, a finding that could prove to be important in furthering our understanding of cathepsin S biology.