[Associations of serum neuromarkers with clinical features of Parkinson's disease]

OBJECTIVE

To evaluate the clinical and laboratory correlation of biomarkers with anti- and pro-apoptotic activity with the severity of motor and non-motor symptoms depending on the progression rate of Parkinson's disease (PD).

MATERIAL AND METHODS

A wide range of non-motor symptoms (emotional-affective, cognitive, psychotic and behavioral disorders, fatigue, sleep disorders and autonomic disorders) was evaluated using validated scales and a number of serum neuromarkers responsible for neuroplasticity and neuronal survival processes (BDNF, PDGF, cathepsin D) in 71 patients with PD (mean age 65 (55; 70) years, disease duration 7 (4; 9) years, age of onset 57 (49; 62) years).

RESULTS

The concentration of biomarkers (BDNF, PDGF and cathepsin D) was the lowest in the group of patients with a rapid PD progression rate (p<0.001, p=0.001 and p=0.031, respectively), the severity of motor and most non-motor symptoms was higher (p=0.023 and p=0.001, respectively) compared to middle and slow progression rate. There were correlations between BDNF concentration and the severity of depression (r=-0.63, p<0.001), apathy (r=-0.48, p<0.001), impulsive behavioral disorders (r=0.500, p<0.001), level of cognitive functions (r=0.54, p<0.001), motor symptoms (r=-0.43, p<0.001); between PDGF level and the severity of motor manifestations of PD (r=-0.30, p=0.011), depression (r=-0.70, p<0.001), apathy (r=-0.460, p<0.001), the degree of severity of behavioral disorders (r=0.742, p<0.001). No significant correlations were observed between the level of cathepsin D and the severity of clinical manifestations of PD, which indicates the connection of cathepsin D with the general pathogenesis of PD.

CONCLUSION

The possibility of using serum proteins of the neurotrophin subfamily and the protein associated with autophagy, cathepsin D, as biomarkers that determine the prognosis of PD, is considered.

Redox State and Lysosomal Activity in Women with Ovarian Cancer with Tumor Recurrence and Multiorgan Metastasis

The aim of the study is to evaluate oxidant-antioxidant balance as well as lysosomal and anti-protease activities in ovarian cancer since it has been emphasized that the crucial inducing factor of carcinogenesis may be reactive oxygen/nitrogen species or, more precisely, oxidative stress-induced inflammation. The study involved 15 women with ovarian cancer, aged 59.9 ± 7.8 years, and 9 healthy women aged 56.3 ± 4.3 years (controls). The study material was venous blood collected from fasting subjects. In erythrocytes, the activities of superoxide dismutase, glutathione peroxidase, and catalase, as well as concentrations of conjugated dienes (CDs) and thiobarbituric acid reactive substances (TBARS), were investigated. CD, TBARS, and vitamins A and E plasma concentrations were also determined. Moreover, total antioxidant capacity and concentrations of 4-hydroxynonenal adducts and 8-iso-prostaglandin F2α, as well as activities of acid phosphatase, arylsulfatase, cathepsin D, and α₁-antitrypsin, were studied in serum. The vitamin E and 8-iso-prostaglandin F2α concentrations as well as arylsulfatase activity were lower in the women with cancer compared to the controls (p = 0.006, p = 0.03, p = 0.001, respectively). In contrast, cathepsin D activity was lower in the controls (p = 0.04). In the peripheral blood of the women with cancer, oxidant-antioxidant and lysosomal disturbances were observed.

Identification of Novel Genomic-Variant Patterns of OR56A5, OR52L1, and CTSD in Retinitis Pigmentosa Patients by Whole-Exome Sequencing

Inherited retinal dystrophies (IRDs) are rare but highly heterogeneous genetic disorders that affect individuals and families worldwide. However, given its wide variability, its analysis of the driver genes for over 50% of the cases remains unexplored. The present study aims to identify novel driver genes, disease-causing variants, and retinitis pigmentosa (RP)-associated pathways. Using family-based whole-exome sequencing (WES) to identify putative RP-causing rare variants, we identified a total of five potentially pathogenic variants located in genes OR56A5, OR52L1, CTSD, PRF1, KBTBD13, and ATP2B4. Of the variants present in all affected individuals, genes OR56A5, OR52L1, CTSD, KBTBD13, and ATP2B4 present as missense mutations, while PRF1 and CTSD present as frameshift variants. Sanger sequencing confirmed the presence of the novel pathogenic variant PRF1 (c.124_128del) that has not been reported previously. More causal-effect or evidence-based studies will be required to elucidate the precise roles of these SNPs in the RP pathogenesis. Taken together, our findings may allow us to explore the risk variants based on the sequencing data and upgrade the existing variant annotation database in Taiwan. It may help detect specific eye diseases such as retinitis pigmentosa in East Asia.

Cardiovascular-related proteins and the abdominal visceral to subcutaneous adipose tissue ratio

BACKGROUND AND AIMS

An increased amount of visceral adipose tissues has been related to atherosclerosis and future cardiovascular events. The present study aims to investigate how the abdominal fat distribution links to plasma levels of cardiovascular-related proteins.

METHOD AND RESULTS

In the Prospective investigation of Obesity, Energy and Metabolism (POEM) study (n = 326, all aged 50 years), abdominal visceral (VAT) and subcutaneous (SAT) adipose tissue volumes were quantified by MRI. Eighty-six cardiovascular-related proteins were measured by the proximity extension assay (PEA). Similar investigations were carried out in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (n = 400, all aged 75 years). In the discovery dataset (POEM), 10 proteins were related to the VAT/SAT-ratio using false discovery rate <.05. Of those, Cathepsin D (CTSD), Interleukin-1 receptor antagonist protein (IL-1RA) and Growth hormone (GH) (inversely) were related to the VAT/SAT-ratio in the validation in PIVUS following adjustment for sex, BMI, smoking, education level and exercise habits (p < 0.05). In a secondary analysis, a meta-analysis of the two samples suggested that 15 proteins could be linked to the VAT/SAT-ratio following adjustment as above and Bonferroni-correction of the p-value.

CONCLUSION

Three cardiovascular-related proteins, cathepsin D, IL-1RA and growth hormone, were being associated with the distribution of abdominal adipose tissue using a discovery/validation approach. A meta-analysis of the two samples suggested that also a number of other cardiovascular-related proteins could be associated with an unfavorable abdominal fat distribution.

Matrix Metalloproteases and Cathepsin D in Human Serum do not Cleave Prolactin to Generate Vasoinhibin

BACKGROUND

Vasoinhibin is generated in the pituitary gland and in multiple target tissues by proteolytic cleavage of prolactin by matrix metalloproteinases and cathepsin D. A dysregulation of vasoinhibin generation appears to contribute to diabetic retinopathy and diabetic macular edema, retinopathy of prematurity, peripartum cardiomyopathy, and preeclampsia. Here, we investigate whether vasoinhibin is generated by matrix metalloproteinases and cathepsin D in human serum.

METHODS

The abundance of matrix metalloproteinases 1, 2, 3, 8, 9, 10, 13, tissue inhibitors of metalloproteinases 1, 2, 4, and the activity of cathepsin D in serum samples were determined. Samples from healthy male (n = 3) and female (n = 2) subjects, pregnant subjects (n = 2), and patients with type 2 diabetes mellitus (n = 2) were investigated. The samples were incubated with recombinant prolactin at 37°C, under different pH, time, and buffer conditions. Prolactin and cleaved prolactin products were investigated by SDS-PAGE and western blotting.

RESULTS

Matrix metalloproteases-1, -2, -3, -8, -9, -10, -13, TIMP-1, -2, and -4, and the activity of cathepsin D were detected in all sera. Full-length prolactin incubated with human sera, containing endogenous matrix metalloproteinases and cathepsin D, remained intact at neutral pH during a time frame from 1 to 24 hours. Partial enzymatic cleavage of prolactin resulting in the generation of a vasoinhibin-like 17 kDa peptide was observed in samples incubated at pH 3.4. Heat inactivation of the serum and the addition of an MMP inhibitor suppressed the generation of the 17 kDa peptide, indicating that its generation was MMP-mediated.

CONCLUSIONS

Vasoinhibin generation by enzymatic cleavage of prolactin by matrix metalloproteases or cathepsin D does not occur in human serum at physiological pH. A limited proteolysis of prolactin, resulting in the generation of a vasoinhibin-like peptide with an apparent molecular weight of 17 kDa occurs in serum at acidic pH. The generation of vasoinhibin may require the cellular and tissue microenvironments.

Enzymatic diagnosis of neuronal lipofuscinoses in dried blood spots using substrates for concomitant tandem mass spectrometry and fluorimetry

Neuronal ceroid lipofuscinoses (NCLs) are a group of neurodegenerative diseases predominantly in childhood that are characterized by psychomotor deterioration, epilepsy, and early death of patients. The NCLs analyzed in the present study are caused by defects of the specific enzymes, CLN1 (palmitoyl protein thioesterase 1; PPT1), CLN2 (tripeptidyl peptidase 1; TPP1), and CLN10 (cathepsin D). Specific and sensitive diagnostic assays of NCLs were the main goal of this study. They are of increasing importance, particularly since enzyme replacement therapy (ERT) for NCL2 has recently become available for clinical treatment, and ERTs for further NCLs are under development. Here, we report specific and sensitive determinations for CLN1, CLN2, and CLN10 on dried blood spots by tandem mass spectrometry using multiple reaction monitoring mass spectrometry (MRM-MS). Identical substrates suitable for (i) fluorimetric determination of single enzymes and (ii) for MRM-MS determination of multiple enzymes were synthesized by chemical coupling of alkyl-umbelliferone building blocks with the corresponding peptidyl-substrate groups recognized by the target enzyme. Enzymatic determinations were performed both by fluorimetry and MRM-MS in patients with NCL1, NCL2, and NCL10 and showed good agreement in single assays. Moreover, duplex and triplex determinations were successfully performed for NCL1, NCL2, and NCL10. Specific peptidyl-(4-alkyl-umbelliferone) substrates were also synthesized for mass spectrometric determinations of different cathepsins (cathepsins-D, -F, and -B), to provide a differentiation of proteolytic specificities.

Effect of metformin and insulin combination on monocyte chemoattractant protein-1 and cathepsin-D in type 2 diabetes mellitus

BACKGROUND AND AIMS

Monocyte chemoattractant protein-1 (MCP-1) and cathepsin-D are progressively raised in type 2 diabetes mellitus (T2DM) with both non proliferative and proliferative retinal disease. This study aimed to evaluate the effect of antidiabetic medications on MCP-1 and cathepsin-D.

METHODS

60 patients of T2DM without retinopathy and 60 of diabetic retinopathy were enrolled to receive metformin (500 mg-1000 mg) combined with either glimepiride (1 mg-2 mg) or insulin. The effect of antidiabetic medications on serum MCP-1 and cathepsin-D was assessed.

RESULTS

Mean MCP-1 (pg/ml) and cathepsin-D (ng/ml) levels were significantly lower in patients of T2DM with and without retinopathy treated with metformin + insulin (468.52 ± 272.84 vs 234.30 ± 180.58; p < 0.01 and 460.15 ± 128.52 vs 517.33 ± 213.49; p = 0.214) as compared to patients treated with metformin + glimepiride (1434.02 ± 105.27 vs 1256.27 ± 76.76; p < 0.01 and 1689.36 ± 752.57 vs 919.69 ± 675.05; p = < 0.01). No significant correlation of MCP-1 and cathepsin-D with HbA1c, fasting and post prandial blood glucose were found.

CONCLUSION

Patients treated with metformin and insulin combination had lower serum MCP-1 and cathepsin-D levels which suggests that this combination may be more effective in reducing the progression of diabetic retinopathy. (CTRI/2018/05/013601).

Plasma Cathepsin D Activity Rather Than Levels Correlates With Metabolic Parameters of Type 2 Diabetes in Male Individuals

Objective

Type 2 diabetes mellitus is a metabolic disorder characterized by insulin resistance. Previous studies in patients demonstrated that plasma levels of cathepsin D (CTSD), which is optimally active in the acidic environment of lysosomes, correlate with insulin resistance. As plasma pH is slightly reduced in type 2 diabetic patients and we have previously shown that plasma CTSD activity is causally linked to insulin levels in vivo, it is likely that the activity of CTSD in plasma will be increased in type 2 diabetes compared to healthy individuals. However, so far the interaction between CTSD activity and levels to postprandial metabolic derangements in type 2 diabetes is not known.

Methods

Eighteen type 2 diabetes and 16 age-matched healthy males were given 2 consecutive standardized mixed meals, after which blood samples were collected. Plasma metabolic parameters as well as CTSD levels and activity were measured, and changes in plasma pH was assessed.

Results

In line with the elevation of plasma free fatty acids (FFA) levels in male type 2 diabetics patients, plasma pH in type 2 diabetic individuals was decreased compared to male healthy individuals. While plasma CTSD levels were similar, plasma CTSD activity was increased in male type 2 diabetic compared to male healthy individuals. Besides, plasma CTSD activity rather than levels significantly correlated with indicators of type 2 diabetes (HbA1c, HOMA-IR and glucose). Furthermore, FFA was also independently associated with plasma CTSD activity (standardized β = 0.493, p = 0.007).

Conclusions

Despite similar plasma CTSD levels, type 2 diabetic male individuals showed increased plasma CTSD activity compared to healthy males, which was independently linked to plasma FFA levels. Our data therefore point toward plasma CTSD as a metabolic regulator in male type 2 diabetes.

Analytical performance of thrombospondin-1 and cathepsin D immunoassays part of a novel CE-IVD marked test as an aid in the diagnosis of prostate cancer

The Prostate Specific Antigen (PSA) test suffers from low specificity for the diagnosis of Prostate Cancer (PCa). We originally discovered two cancer-related proteins thrombospondin-1 (THBS1) and cathepsin D (CTSD) using a mass-spectrometry-based proteomics approach. The two serum proteins were shown to improve the diagnosis of high-grade PCa. Thus, we developed quantitative ELISAs for the determination of their concentration in human serum. Here we report their analytical performance in terms of limit of detection, specificity, precision, linearity and interferences, which were determined based on CLSI guidelines. Further, we investigated the influence of pre-analytical factors on concentration measurements. For this, blood from 4-6 donors was collected in different tubes and stored at room temperature for different times prior to centrifugation at different centrifugal forces and temperatures. Stability of THBS1 and CTSD under different storage temperatures was also evaluated. Our results show that the assays are specific, linear and sensitive enough to allow measurement of clinical samples. Precision in terms of repeatability and total within-laboratory coefficient of variation (CV) are 5.5% and 8.1% for THBS1 and 4.3% and 7.2% for CTSD, respectively. Relative laboratory-to-laboratory differences were -6.3% for THBS1 and -3% for CTSD. Both THBS1 and CTSD were stable in serum samples, with 80-120% recoveries of concentrations across donors, sample preparation and storage. In conclusion, the ELISAs as part of the novel commercial in vitro diagnostic test Proclarix are suitable for the use in clinical practice. THBS1 and CTSD can be accurately measured for their intended use independent of the lot and laboratory when conditions consistent with routine practice for PSA sampling and storage are used.

Plasma cathepsin D activity is negatively associated with hepatic insulin sensitivity in overweight and obese humans

AIMS/HYPOTHESIS

Insulin resistance in skeletal muscle and liver plays a major role in the pathophysiology of type 2 diabetes. The hyperinsulinaemic-euglycaemic clamp is considered the gold standard for assessing peripheral and hepatic insulin sensitivity, yet it is a costly and labour-intensive procedure. Therefore, easy-to-measure, cost-effective approaches to determine insulin sensitivity are needed to enable organ-specific interventions. Recently, evidence emerged that plasma cathepsin D (CTSD) is associated with insulin sensitivity and hepatic inflammation. Here, we aimed to investigate whether plasma CTSD is associated with hepatic and/or peripheral insulin sensitivity in humans.

METHODS

As part of two large clinical trials (one designed to investigate the effects of antibiotics, and the other to investigate polyphenol supplementation, on insulin sensitivity), 94 overweight and obese adults (BMI 25-35 kg/m²) previously underwent a two-step hyperinsulinaemic-euglycaemic clamp (using [6,6-²H₂]glucose) to assess hepatic and peripheral insulin sensitivity (per cent suppression of endogenous glucose output during the low-insulin-infusion step, and the rate of glucose disappearance during high-insulin infusion [40 mU/(m² × min)], respectively). In this secondary analysis, plasma CTSD levels, CTSD activity and plasma inflammatory cytokines were measured.

RESULTS

Plasma CTSD levels were positively associated with the proinflammatory cytokines IL-8 and TNF-α (IL-8: standardised β = 0.495, p < 0.001; TNF-α: standardised β = 0.264, p = 0.012). Plasma CTSD activity was negatively associated with hepatic insulin sensitivity (standardised β = -0.206, p = 0.043), independent of age, sex, BMI and waist circumference, but it was not associated with peripheral insulin sensitivity. However, plasma IL-8 and TNF-α were not significantly correlated with hepatic insulin sensitivity.

CONCLUSIONS/INTERPRETATION

We demonstrate that plasma CTSD activity, but not systemic inflammation, is inversely related to hepatic insulin sensitivity, suggesting that plasma CTSD activity may be used as a non-invasive marker for hepatic insulin sensitivity in humans.

In search of causal pathways in diabetes: a study using proteomics and genotyping data from a cross-sectional study

AIMS/HYPOTHESIS

The pathogenesis of type 2 diabetes is not fully understood. We investigated whether circulating levels of preselected proteins were associated with the outcome 'diabetes' and whether these associations were causal.

METHODS

In 2467 individuals of the population-based, cross-sectional EpiHealth study (45-75 years, 50% women), 249 plasma proteins were analysed by the proximity extension assay technique. DNA was genotyped using the Illumina HumanCoreExome-12 v1.0 BeadChip. Diabetes was defined as taking glucose-lowering treatment or having a fasting plasma glucose of ≥7.0 mmol/l. The associations between proteins and diabetes were assessed using logistic regression. To investigate causal relationships between proteins and diabetes, a bidirectional two-sample Mendelian randomisation was performed based on large, genome-wide association studies belonging to the DIAGRAM and MAGIC consortia, and a genome-wide association study in the EpiHealth study.

RESULTS

Twenty-six proteins were positively associated with diabetes, including cathepsin D, retinal dehydrogenase 1, α-L-iduronidase, hydroxyacid oxidase 1 and galectin-4 (top five findings). Three proteins, lipoprotein lipase, IGF-binding protein 2 and paraoxonase 3 (PON-3), were inversely associated with diabetes. Fourteen of the proteins are novel discoveries. The Mendelian randomisation study did not disclose any significant causal effects between the proteins and diabetes in either direction that were consistent with the relationships found between the protein levels and diabetes.

CONCLUSIONS/INTERPRETATION

The 29 proteins associated with diabetes are involved in several physiological pathways, but given the power of the study no causal link was identified for those proteins tested in Mendelian randomisation. Therefore, the identified proteins are likely to be biomarkers for type 2 diabetes, rather than representing causal pathways.

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.

Cathepsin D improves the prediction of undetected diabetes in patients with myocardial infarction

Background: Newer therapeutic agents for type 2 diabetes mellitus can improve cardiovascular outcomes, but diabetes remains underdiagnosed in patients with myocardial infarction (MI). We sought to identify proteomic markers of undetected dysglycaemia (impaired fasting glucose, impaired glucose tolerance, or diabetes mellitus) to improve the identification of patients at highest risk for diabetes. Materials and methods: In this prospective cohort, 626 patients without known diabetes underwent oral glucose tolerance testing (OGTT) during admission for MI. Proximity extension assay was used to measure 81 biomarkers. Multivariable logistic regression, adjusting for risk factors, was used to evaluate the association of biomarkers with dysglycaemia. Subsequently, lasso regression was performed in a 2/3 training set to identify proteomic biomarkers with prognostic value for dysglycaemia, when added to risk factors, fasting plasma glucose, and glycated haemoglobin A1c. Determination of discriminatory ability was performed in a 1/3 test set. Results: In total, 401/626 patients (64.1%) met the criteria for dysglycaemia. Using multivariable logistic regression, cathepsin D had the strongest association with dysglycaemia. Lasso regression selected seven markers, including cathepsin D, that improved prediction of dysglycaemia (area under the receiver operator curve [AUC] 0.848 increased to 0.863). In patients with normal fasting plasma glucose, only cathepsin D was selected (AUC 0.699 increased to 0.704). Conclusions: Newly detected dysglycaemia, including manifest diabetes, is common in patients with acute MI. Cathepsin D improved the prediction of dysglycaemia, which may be helpful in the a priori risk determination of diabetes as a motivation for confirmatory OGTT.

Meta-analysis for assessing the healing process of ulcers among diabetic patients: Cases of HbA1c, lipid, S. Creatinine, Adiponectin, Cat D, HSP70, HSP47, 25-hydroxy vitamin D

BACKGROUND

The study aims to investigate the significance of predictors including HbA1c, Lipid, S. Creatinine, Adiponectin, Cat D, HSP70, HSP47, and 25-hydroxy vitamin D and to evaluate the rate of healing of ulcers among the diabetic foot patients.

METHODS

A retrospective method is used to quantitatively assess the role of HbA1c, Lipid, S. Creatinine, Adiponectin, Cat D, HSP70, HSP47, and 25-hydroxy vitamin D in the healing process of ulcer among diabetic patients. A total of 192 diabetic patients were included, who underwent ulcer healing diagnosis.

RESULTS

The results have shown a positive and significant correlation between Adiponectin and Cat D with group 2. The findings have shown higher prevalence of Cad D among patients with group 1, HSP70 among patients with group 2, HSP47 among patients with group 2, and 25-hydroxy vitamin D among patients with group 1.

CONCLUSION

The study concluded that insignificant predictors should be assessed more comprehensively to reveal its efficacy on healing of ulcers with different grades.

Development and clinical testing of individual immunoassays for the quantification of serum glycoproteins to diagnose prostate cancer

Prostate Cancer (PCa) diagnosis is currently hampered by the high false-positive rate of PSA evaluations, which consequently may lead to overtreatment. Non-invasive methods with increased specificity and sensitivity are needed to improve diagnosis of significant PCa. We developed and technically validated four individual immunoassays for cathepsin D (CTSD), intercellular adhesion molecule 1 (ICAM1), olfactomedin 4 (OLFM4), and thrombospondin 1 (THBS1). These glycoproteins, previously identified by mass spectrometry using a Pten mouse model, were measured in clinical serum samples for testing the capability of discriminating PCa positive and negative samples. The development yielded 4 individual immunoassays with inter and intra-variability (CV) <15% and linearity on dilution of the analytes. In serum, ex vivo protein stability (<15% loss of analyte) was achieved for a duration of at least 24 hours at room temperature and 2 days at 4°C. The measurement of 359 serum samples from PCa positive (n = 167) and negative (n = 192) patients with elevated PSA (2–10 ng/ml) revealed a significantly improved accuracy (P <0.001) when two of the glycoproteins (CTSD and THBS1) were combined with %fPSA and age (AUC = 0.8109; P <0.0001; 95% CI = 0.7673–0.8545). Conclusively, the use of CTSD and THBS1 together with commonly used parameters for PCa diagnosis such as %fPSA and age has the potential to improve the diagnosis of PCa.

Association of increased levels of MCP-1 and cathepsin-D in young onset type 2 diabetes patients (T2DM-Y) with severity of diabetic retinopathy

AIM

Young onset type 2 diabetes patients (T2DM-Y) have been shown to possess an increased risk of developing microvascular complications particularly diabetic retinopathy. However, the molecular mechanisms are not clearly understood. In this study, we investigated the serum levels of monocyte chemotactic protein 1 (MCP-1) and cathepsin-D in patients with T2DM-Y without and with diabetic retinopathy.

METHODS

In this case-control study, participants comprised individuals with normal glucose tolerance (NGT=40), patients with type 2 diabetes mellitus (T2DM=35), non-proliferative diabetic retinopathy (NPDR=35) and proliferative diabetic retinopathy (PDR=35). Clinical characterization of the study subjects was done by standard procedures and MCP-1 and cathepsin-D were measured by ELISA.

RESULTS

Compared to control individuals, patients with T2DM-Y, NPDR and PDR exhibited significantly (p<0.001) higher levels of MCP-1. Cathepsin-D levels were also significantly (p<0.001) higher in patients with T2DM-Y without and with diabetic retinopathy. Correlation analysis revealed a positive association (p<0.001) between MCP-1 and cathepsin-D levels. There was also a significant negative correlation of MCP1/cathepsin-D with C-peptide levels. The association of increased levels of MCP-1/cathepsin-D in patients with DR persisted even after adjusting for all the confounding factors.

CONCLUSION

As both MCP-1 and cathepsin-D are molecular signatures of cellular senescence, we suggest that these biomarkers might be useful to predict the development of retinopathy in T2DM-Y patients.

Serum levels of cathepsin D, sirtuin1, and endothelial nitric oxide synthase are correlatively reduced in elderly healthy people

AIM

Nowadays, cathepsins have been reported to be related to aging. The aim of this study is to evaluate the association between serum levels of cathepsin D (CTSD) and human aging.

METHODS

In the present study, we analyzed the serum levels of CTSD and its relation with levels of sirtuin1 (SIRT1) and endothelial nitric oxide synthase (eNOS) activity, which were known having an important role in aging. This study recruited 90 healthy subjects (62 men and 28 women), which were subdivided into three groups with respect to age: young (about 19 years old, n = 30), middle-age (about 40 years old, n = 30), and aged (above 65 years old, n = 30). Altered serum levels of CTSD and SIRT1 were measured by enzyme-linked immunosorbent assay, and eNOS activity was assessed by the conversion of 14(C)-L-arginine to 14(C)-L-citrulline.

RESULTS

Elderly subjects had significantly lower CTSD, SIRT1, and eNOS than younger ones. Serum levels of CTSD were negatively correlated with age. There was a statistically significant positive correlation between serum levels of CTSD, eNOS, and SIRT1.

CONCLUSIONS

This study shows lower serum CTSD values in elderly subjects than in younger subjects. This is the first to demonstrate age-related changes in cathepsin D levels in humans and the association between SIRT1 and eNOS.

Protein Biomarkers for Insulin Resistance and Type 2 Diabetes Risk in Two Large Community Cohorts

Insulin resistance (IR) is a precursor of type 2 diabetes (T2D), and improved risk prediction and understanding of the pathogenesis are needed. We used a novel high-throughput 92-protein assay to identify circulating biomarkers for HOMA of IR in two cohorts of community residents without diabetes (n = 1,367) (mean age 73 ± 3.6 years). Adjusted linear regression identified cathepsin D and confirmed six proteins (leptin, renin, interleukin-1 receptor antagonist [IL-1ra], hepatocyte growth factor, fatty acid-binding protein 4, and tissue plasminogen activator [t-PA]) as IR biomarkers. Mendelian randomization analysis indicated a positive causal effect of IR on t-PA concentrations. Two biomarkers, IL-1ra (hazard ratio [HR] 1.28, 95% CI 1.03-1.59) and t-PA (HR 1.30, 1.02-1.65) were associated with incident T2D, and t-PA predicted 5-year transition to hyperglycemia (odds ratio 1.30, 95% CI 1.02-1.65). Additional adjustment for fasting glucose rendered both coefficients insignificant and revealed an association between renin and T2D (HR 0.79, 0.62-0.99). LASSO regression suggested a risk model including IL-1ra, t-PA, and the Framingham Offspring Study T2D score, but prediction improvement was nonsignificant (difference in C-index 0.02, 95% CI -0.08 to 0.12) over the T2D score only. In conclusion, proteomic blood profiling indicated cathepsin D as a new IR biomarker and suggested a causal effect of IR on t-PA.

Altered lysosomal proteins in neural-derived plasma exosomes in preclinical Alzheimer disease

OBJECTIVE

Diverse autolysosomal proteins were quantified in neurally derived blood exosomes from patients with Alzheimer disease (AD) and controls to investigate disordered neuronal autophagy.

METHODS

Blood exosomes obtained once from patients with AD (n = 26) or frontotemporal dementia (n = 16), other patients with AD (n = 20) both when cognitively normal and 1 to 10 years later when diagnosed, and case controls were enriched for neural sources by anti-human L1CAM antibody immunoabsorption. Extracted exosomal proteins were quantified by ELISAs and normalized with the CD81 exosomal marker.

RESULTS

Mean exosomal levels of cathepsin D, lysosome-associated membrane protein 1 (LAMP-1), and ubiquitinylated proteins were significantly higher and of heat-shock protein 70 significantly lower for AD than controls in cross-sectional studies (p ≤ 0.0005). Levels of cathepsin D, LAMP-1, and ubiquitinylated protein also were significantly higher for patients with AD than for patients with frontotemporal dementia (p ≤ 0.006). Step-wise discriminant modeling of the protein levels correctly classified 100% of patients with AD. Exosomal levels of all proteins were similarly significantly different from those of matched controls in 20 patients 1 to 10 years before and at diagnosis of AD (p ≤ 0.0003).

CONCLUSIONS

Levels of autolysosomal proteins in neurally derived blood exosomes distinguish patients with AD from case controls and appear to reflect the pathology of AD up to 10 years before clinical onset. These preliminary results confirm in living patients with AD the early appearance of neuronal lysosomal dysfunction and suggest that these proteins may be useful biomarkers in large prospective studies.

[Cathepsin D and B activity in the serum of patients with urothelial bladder cancer]

The key role of cathepsin D and B is intralysosomal digestion of used cellular proteins and other proteins that enter cells through endocytosis. Under pathological conditions like cancer formation and growth, cathepsins from lysosomes are released. The aim of the study was to determin of cathepsin D and B activities in serum of patients with urothelial bladder cancer depending on disease severity and determination of its' changes after transurethral resection of tumor.

MATERIAL AND METHODS

Experiment involved 50 patients. Blood samples were obtained from 18 healthy volunteers and 32 urothelial bladder cancer patients. Samples from people with suspected urothelial bladder cancer were collected three times: before the surgery, 2 weeks and 6 weeks after the surgical treatment.

RESULTS

Our research showed that cathepsin D activity, measured as the level increment of acid soluble tyrosine, is the highest before the surgery in muscle invasive bladder tumor (pT2) (57,9 nmol/ml). 2 weeks and 6 weeks after the surgical treatment, cathepsin D activity is decreased. In case of cathepsin B activity, measured as the level of released p-nitroaniline, decreased, 2 weeks and 6 weeks after the surgical treatment in both cases of disease severity.

CONCLUSION

Cathepsin D and B activities in the serum of patients with urothelial bladder cancer are directly proportional to disease severity and significantly higher compared with control group. Transuretral resection of the tumor leads to diminution of their activities in second and 6th week after the procedure.

The activity of cathepsin D and alpha-1 antitrypsin in hip and knee osteoarthritis

The progress of cartilage decay during joint degeneration is not well monitored with biochemical methods. The role of cathepsin D (CAT-D) in articular cartilage deterioration remains unclear. The aim of this study is to assess the activity of CAT-D and alpha-1 antitrypsin (AAT) in blood in patients with hip or knee osteoarthritis. The activity of CAT-D and AAT in blood serum of 40 women and 21 men with hip or knee osteoarthritis was determined before total joint replacement, on the tenth day after surgery, and once in 54 healthy patients. The preoperative activity of CAT-D in patients with osteoarthritis was lower by 53.6% (11.00 ± 4.54 10(-2) nM released tyrosine/mg protein/min, P < 0.001) and after surgery by 55.0% (10.67 ± 4.64 10(-2) nM released tyrosine/mg protein/min, P < 0.001) when compared to its activity in healthy patients. There was no significant statistical difference between CAT-D activity before the surgery and its activity on the tenth day after it in the analyzed group (P< 0.496). Simultaneously, the preoperative activity of AAT in the OA (osteoarthritis) patients was by 25.5% (0.93 ± 0.32 mg inhibited trypsin/ml blood serum, P < 0.001) and postoperative was by 44.9% higher (1.26 ± 0.36 mg inhibited trypsin/ml blood serum, P < 0.001) than in healthy patients. The low CAT-D activity in osteoarthritis of big joints is associated with a decrease of cartilage cells during the degenerative process. The higher activity of acute phase protein AAT in OA patients' blood serum confirms the inflammatory component in the osteoarthritis process.

Plasma adenosine triphosphate and heat shock protein 72 concentrations after aerobic and eccentric exercise

The endolysosome pathway has been proposed for secretion of heat shock protein (Hsp)72 with a regulatory role for extracellular adenosine triphosphate (ATP). Here, we tested the hypothesis that extracellular ATP mediates the increase in plasma Hsp72 after exercise. We measured plasma ATP Hsp72, cathepsin D, norepinephrine, free fatty acid, glucose, and myoglobin in 8 healthy young males (mean +/- SE: age, 22.3 +/- 0.3 years; height, 171.4 +/- 0.8 cm; weight, 68.8 +/- 3.1 kg; body mass index, 23.5 +/- 1.1 kg/cm2; VO2 max, 44.1 +/- 3.8 mL/kg/min) before and at 0, 10, 30, and 60 min after aerobic exercise (cycling) and elbow flexor eccentric exercise. Subjects cycled for 60 min at 70-75% VO2 max (mean +/- SE; 157.4 +/- 6.9 W). Eccentric strength exercise consisted of flexing the elbow joint to 90 degrees with motion speed set at 30 degrees/sec at extension and 10 degrees/sec at flexion. Subjects performed 7 sets of 10 eccentric actions with a set interval of 60 sec. The motion range of the elbow joint was 90 degrees-180 degrees. Compared with the levels of Hsp72 and ATP in plasma after bicycle exercise, those after eccentric exercise did not change. A significant group x time interaction was not observed for Hsp72 or ATP in plasma. A significant correlation was found between Hsp72 and ATP in plasma (r=0.79, P<0.05), but not between Hsp72 and norepinephrine (r=0.64, P=0.09) after bicycle exercise. A significant correlation between ATP and norepinephrine in plasma was found (r=0.89 P<0.01). We used stepwise multiple-regression analysis to determine independent predictors of exercise-induced elevation of eHsp72. Candidate predictor variables for the stepwise multiple-regression analysis were time (Pre, Post, Post10, Post30, Post60), exercise type (aerobic, eccentric), ATP, cathepsin D, norepinephrine, epinephrine, glucose, and FFA. In the regression model for Hsp72 in plasma, increased ATP and glucose were the strongest predictors of increased Hsp72 (ATP: R2=0.213, beta=0.473, P=0.000; ATP and glucose: R2=0.263, beta=0.534, P=0.000). Collectively, these results imply that ATP in plasma is a trigger of Hsp72 release after exercise.

Ov-APR-1, an aspartic protease from the carcinogenic liver fluke, Opisthorchis viverrini: functional expression, immunolocalization and subsite specificity

The human liver fluke Opisthorchis viverrini is endemic in Thailand, Laos and Cambodia where long standing infection is associated with cancer of the bile ducts, cholangiocarcinoma. Here we describe a cathepsin D-like aspartic protease from the gut and other tissues in O. viverrini. Phylogenetic analysis indicated that Ov-APR-1 is cathepsin D-like, conforming with Clan AA, Family A1 of the MEROPS classification. Ov-APR-1 is expressed in the gut of the mature hermaphroditic parasite, in the reproductive tissues including the testis and immature spermatids, and the developing miracidium within the eggshell. The enzyme was also detected in the excretory/secretory products of cultured adult flukes, indicating a role in host-parasite relationships. A recombinant form of the enzyme expressed in Escherichia coli and refolded from denatured inclusion bodies underwent autocatalytic activation and demonstrated hydrolytic activity against the peptide substrate 7-methoxycoumarin-4-acetyl-GKPILFFRLK(DNP)-D-Arg-amide with a k(cat)/K(m)=1.7 x 10(4)M(-1)s(-1) and a pH optimum around pH 2.5-3.0. The recombinant enzyme digested hemoglobin and bovine serum albumin. Forty-six serum albumin peptides were detected after digestion with recombinant Ov-APR-1 and sequenced. Like many other aspartic proteases, Ov-APR-1 displayed promiscuous preferences for residues accommodated at the key subsites of the binding pocket although hydrophobic (Leu, Ala, Ile), positively charged (Lys) and bulky aromatic (Phe) residues, in that order, were preferred at P1. Similar residues were accommodated at P1' although even less selectivity was exerted at this position.

Vitellogenin, zona radiata protein, cathepsin D and heat shock protein 70 as biomarkers of exposure to xenobiotics

The antagonistic and/or synergistic effects of different chemical compounds were examined in the marine teleost, Gobius niger, by testing a series of biomarkers involved in fish reproduction. Among the biomarkers analysed, vitellogenin (VTG) and zona radiata proteins (ZRP) are key molecules involved in reproduction, widely used to detect the presence of pollutants in the marine environment, while heat shock protein 70 (HSP70) and cathepsin D (CATD) have recently been introduced as bioindicators of endocrine disruption. The detection of VTG and ZRP in the plasma of wild male specimens is universally accepted as an early warning signal of environmental pollution. The evaluation of VTG, ZRP and CATD expression demonstrated the oestrogenic effect of nonylphenol on both male and female fish; on the contrary beta-naphthoflavone behaves mainly as an anti-oestrogen although, when co-injected with compounds with oestrogenic activity, it enhances ZRP gene expression. Regarding the chaperone, all treatments stressed the fish, inducing an increase in HSP70 gene transcription. The results obtained underlined the importance of testing the effects of compound mixtures: fish in the wild are subjected to a blend of chemicals and the effects observed derive from the synergic or antagonistic interactions of these compounds.

Cathepsin D and carcino-embryonic antigen in serum, urine and tissues of colon adenocarcinoma patients

BACKGROUND/AIMS

Application of neoplastic markers in early diagnosis of colorectal carcinoma has brought fresh hope to millions of sufferers. However such a marker, distinctive for this particular carcinoma and allowing its detection at a sufficiently early stage of development has not yet been found. Cathepsin D (CD) is lysosomal aspartyl proteinase. It is a component of a proteolytic cascade participating actively in neoplastic invasion as well as in metastasis formation. Carcino-embryonic antigen (CEA) is a useful marker in oncological diagnostics of colorectal cancer. CEA undergoes expression in all kinds of adenocarcinoma and is found both intercellularly and extracellularly. High concentrations of CEA in the blood serum confirm neoplastic changes in the digestive tract with high probability. The objective of this study has been to evaluate CD activity in the blood serum, urine and tumor tissues as well as in the colon biopsies which were not changed macroscopically and CEA concentration in the serum of colon adenocarcinoma, considering the extent of spread of cancer (TNM), the grade of the differentiation of cancer cell (G) as well as the tumor size. The possibility of application of CD along with CEA as markers of colon adenocarcinoma has also been examined.

METHODOLOGY

The examination included the serum and urine of 21 patients as well as 12 tissues biopsies with histopathologically confirmed colon adenocarcinoma. The reference group for the blood and urine comprised of 17 healthy controls, and for the colon adenocarcinoma tissues- samples collected from 14 people from the sites most distant from the resected tumor on the boundaries which were free of cancer cells. Activity of CD in the blood serum, urine as well as tissues was determined with a modified Greczaniuk et al. method and expressed by the amount of released tyrosine as the concentration of the activity in nmolTyr/mL/6h, whereas the specific activity was expressed in nmol Tyr/mg of protein /6h. The specific activity of CD in the urine was expressed in nmol Tyr/mg of creatinine/6h. CEA concentration in the blood serum was determined by the immunoenzymatic method (MEIA) on Axym Abbot Analyzer and was expressed in ng/mL. The protein concentration was determined by the Lowry method, and the results were expressed in mg/mL. The creatinine concentration in the urine was determined by the Jaffe method (without deproteinization) and was expressed in mg/100mL.

RESULTS

CD activity was increased in the blood serum (p < 0.0001) and tissues (p = 0.022) of colon adenocarcinoma patients in comparison to the reference group. CD specific activity (Tyr/mg of protein/6h) was significantly increased in serum but decreased in the urine (p < 0.0001) whereas the specific activity of CD (nmol Tyr/mg of creatinine/6h) was increased in the urine (p = 0.0001). CD specific activity has tendency to increase in colon adenocarcinoma tissues (p = 0.441) as compared to the reference group. By examining data in regard to TNM clinical-histopathological classification, G and the tumor size, it could be concluded that CD activity in serum and urine in colon adenocarcinoma patients depends on progress of cancer in which CD activity increases with TNM. A statistically significant increase in CEA concentration was found in the serum of colon adenocarcinoma patients, which was almost threefold higher than the in reference group. No significant differences in CEA concentration were found depending on TNM, G and tumor size.

CONCLUSIONS

The results of this study suggest that examination of CD activity and CEA concentration in serum, as well as CD activity in the urine, might be used in oncological diagnostics of colon adenocarcinoma.

The effect of combined therapy on activity of cathepsin D and alpha-1-antitrypsin in the blood serum of women with cervical cancer

PURPOSE OF INVESTIGATION

The aim of the study was to determine the activity of cathepsin D (CTSD) and alpha-1-antitrypsin (AAT) in the blood serum of women with cervical carcinoma treated with different modes of therapy.

METHODS

The study was conducted on 68 women suffering from carcinoma of the uterine cervix, that were irradiated intracavitarily by a Selectron LDR brachytherapy unit. Additionally, all patients were treated with different therapy methods according to clinical stage.

RESULTS

In women with cervical cancer, CTSD activity was higher while AAT activity was lower both before and after brachytherapy sessions as compared to controls. Six months after the end of therapy, the activity of CTSD and AAT reverted back to the values characteristic for healthy women.

CONCLUSION

The estimation of cathepsin D and alpha-1-antitrypsin activity during the course of cervical cancer management may be useful in early detection of potential recurrence and/or widespread metastasis formation.

Cathepsin D serum levels are not a valid serum marker in renal cell carcinoma

BACKGROUND

It was the aim of this study to evaluate the serum levels of cathepsin D (Cath D) as a diagnostic tool in patients with renal cell carcinoma (RCC) in comparison with healthy volunteers.

METHODS

Cath D serum levels were measured in serum samples obtained preoperatively from 32 patients with histologically confirmed RCC versus 30 healthy individuals using an enzyme immunoassay. Additionally, for the tumor group, Cath D serum levels were correlated with tumor stage and grade as determined according to the 2002 TNM classification.

RESULTS

The serum Cath D concentration was not significantly different in patients with RCC compared with healthy individuals (mean 16.58 vs. 16.64 ng/ml; p = 0.43). Furthermore, there was no significant association between Cath D serum levels and several patient or tumor characteristics such as tumor stage, tumor grade, lymph node status, presence of metastasis, gender or age.

CONCLUSIONS

In contrast to overexpression of Cath D in primary RCC tissue, serum Cath D is not altered in RCC patients when compared with healthy volunteers. In this small cohort, Cath D serum levels did not reveal additional clinical information in patients diagnosed with a small renal mass. Further prospective multicenter studies might shed more light on the value of Cath D in the diagnostics of RCC.

Biomarker Discovery from Uveal Melanoma Secretomes: Identification of gp100 and Cathepsin D in Patient Serum

There is a necessity to better characterize uveal melanoma (UM) tumors according to their metastasis potential at an early stage. In this study we report the identification of potential biomarkers by a combination of proteomics-related approaches: the characterization of UM cell secretomes, the analysis of UM autoantibodies, and the differential depleted serum proteome analysis. We describe a possible role of cathepsin D, syntenin, and gp100 in UM as potential biomarkers.

A cathepsin D-cleaved 16 kDa form of prolactin mediates postpartum cardiomyopathy

Postpartum cardiomyopathy (PPCM) is a disease of unknown etiology and exposes women to high risk of mortality after delivery. Here, we show that female mice with a cardiomyocyte-specific deletion of stat3 develop PPCM. In these mice, cardiac cathepsin D (CD) expression and activity is enhanced and associated with the generation of a cleaved antiangiogenic and proapoptotic 16 kDa form of the nursing hormone prolactin. Treatment with bromocriptine, an inhibitor of prolactin secretion, prevents the development of PPCM, whereas forced myocardial generation of 16 kDa prolactin impairs the cardiac capillary network and function, thereby recapitulating the cardiac phenotype of PPCM. Myocardial STAT3 protein levels are reduced and serum levels of activated CD and 16 kDa prolactin are elevated in PPCM patients. Thus, a biologically active derivative of the pregnancy hormone prolactin mediates PPCM, implying that inhibition of prolactin release may represent a novel therapeutic strategy for PPCM.

Cathepsin D Is Secreted from M-BE Cells: Its Potential Role as a Biomarker of Lung Cancer

The early diagnosis of lung cancer is an effective approach to reduce the mortality caused by malignancy. To explore serum biomarkers of lung cancer at early stage, M-BE, a SV40T-transformed human bronchial epithelial cell line with the phenotypic features of early tumorigenesis at high passage, was cultured in the conditioned media to collect its secretory proteins. The proteins secreted from different passage M-BE cells were extracted and then separated by two-dimensional electrophoresis (2-DE). MALDI-TOF/TOF mass spectrometry was adopted to identify the passage-dependent 2-DE spots. Totally, 47 proteins were identified, including 23 that were up-regulated and 24 that were down-regulated. Of these proteins, cathepsin D was a typical secretory protein that exhibited the increased abundance either in culture media or in cells during passaging. Furthermore, the proteomic conclusions were validated in the clinical samples of lung cancer patients. When sandwich ELISA was used, the concentrations of cathepsin D in plasma showed significant differences between lung squamous cell carcinomas (SCC, 104 cases) and normal donors (36 cases, p <or= 0.015). When tissue microarray (TMA) was used, cathepsin D expression levels in SCC tissues (178 cases) were significantly higher than those in normal donors (40 cases, p < 0.001). The present study has revealed that M-BE cells at different passages could secrete or release some proteins into the living environment, which might serve as the potential resource for exploring the biomarkers of lung cancer.

[Activity of cathepsin D in the blood serum and urine of patients with cancer of the stomach, pancreas and liver]

Cathepsin D is a protease involved in invasion of the cancer and metastasis formation. The purpose of the study was to evaluate a prognostic value of cathepsin D activity in blood serum and urine of patients with cancer of the stomach, pancreas and liver. The study was carried out on the samples of blood serum and urine obtained from patients with cancer of the stomach, pancreas and liver treated surgically at the First Department of General Surgery and Endocrinology of the Medical University of Białystok. The control group consisted of healthy individuals. Activity of cathepsin D was determined in serum and urine by the Folin-Ciocaltau method with the cupric modification and was expressed in nmol Tyr/ml/6h. Specific activity of cathepsin D was determined in the urine, and was expressed in nmol Tyr/mg of protein/6h. Protein concentration in serum was assessed with Lowry et al. method and results were expressed in mg/ml. A significant increase in activity of cathepsin D in serum (p = 0.0169) and urine (p = 0.0008) and an enhanced specific activity in the urine (p = 0.0085) was found in patients with cancer of the pancreas as compared with the controls. A significantly increased activity of cathepsin was revealed in serum (p = 0.0233) of patients with cancer of the stomach. No significant differences of cathepsin D activity were found in urine of the patients with cancer of the stomach when compared to the controls. Additionally, an upward tendency (almost two-fold increase) of cathepsin D activity was shown in blood serum and an increase in the activity and in specific activity was observed in urine of both patients with cancer of the liver in comparison with the healthy individuals. There were no significant differences in the activity of cathepsin D in serum of the patients with cancer of the pancreas and stomach (p = 0.4156). A statistically significantly higher activity (p = 0.0004) and specific (0.0048) cathepsin D activity was demonstrated in urine of the patients with cancer of the pancreas in comparison with the patients with cancer of the stomach. Determination of protein level in urine proved a downward tendency in the patients with cancer of the stomach (p = 0.11109), as compared to the controls, and a statistically significant increase found in the patients with cancer of the pancreas (p = 0.0238), in comparison with the patients with cancer of the stomach. In conclusion, investigation of cathepsin D activity in the blood serum of patients with cancer of the stomach and pancreas and in the urine of the patients with cancer of the pancreas may be usefull in clinical oncological diagnostics. However, further studies of the enzyme are necessary to establish the clinical value of cathepsin D measurement.

Preventive effect of naringin on cardiac markers, electrocardiographic patterns and lysosomal hydrolases in normal and isoproterenol-induced myocardial infarction in Wistar rats

Diets rich in natural antioxidants are associated with reduced risk of heart diseases. This study was aimed to evaluate the preventive role of naringin on cardiac troponin T (cTnT), lactate dehydrogenase (LDH)-isoenzyme, cardiac marker enzymes, electrocardiographic (ECG)-patterns and lysosomal enzymes in isoproterenol (ISO)-induced myocardial infarction (MI) in male Wistar rats. Rats subcutaneously injected with ISO (85mg/kg) at an interval of 24h for 2 days showed a significant increase in the levels of cTnT, intensity of the bands of LDH-isoenzyme (LDH1 and LDH2) and the activities of cardiac marker enzymes such as creatine kinase-MB (CK-MB), creatine kinase (CK), LDH, aspartate transaminase (AST) and alanine transaminase (ALT) in serum with subsequent decrease in the activities of CK, LDH, AST and ALT in the heart and alterations in ECG-patterns. The activities of lysosomal enzymes (beta-glucuronidase, beta-N-acetyl glucosaminidase, beta-galactosidase, cathepsin-B and cathepsin-D) were increased significantly in serum and the heart of ISO-induced rats, but the activities of beta-glucuronidase and cathepsin-D were decreased significantly in the lysosomal fraction of the heart. Pretreatment with naringin (10, 20 or 40mg/kg) daily for a period of 56 days positively altered the levels of cTnT, intensity of the bands of the LDH1 and LDH2-isoenzyme and the activities of cardiac marker enzymes, ECG-patterns and lysosomal hydrolases in ISO-induced rats. Thus, naringin possess cardioprotective effect in ISO-induced MI in rats.

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.

Suppression of tumor growth and invasion in 9,10 dimethyl benz(a) anthracene induced mammary carcinoma by the plant bioflavonoid quercetin

Administration of quercetin, a common polyphenolic component of many vascular and edible plants including vegetables, fruits and tea significantly reduced the tumor volume in rats induced for mammary carcinoma using dimethyl benz (a) anthracene (DMBA). Dose response was assessed, by treating the animals with different doses (15-45 mg/kgbw) of quercetin and 25 mg/kgbw was taken as effective dose. Quercetin was administered as an intra tumoral injection once a week for 4 weeks. Serum levels of carcino embryonic antigen (CEA), a potent marker for tumor growth and invasion was significantly decreased on quercetin treatment. Quercetin caused a significant decrease in the activities of acid phosphatase and Cathepsin D in serum of experimental animals. Activities of lysosomal enzymes- (beta-D galactosidase, beta-D glucuronidase, beta-D glucosidase and sialidase), in serum and tissue were significantly altered in DMBA animals compared to control animals. However, quercetin treatment caused no significant change in lysosomal enzyme activities in tissues, whereas the activities were significantly lowered in serum. Partial purification of tissue type plasminogen activator (t-PA) from the tumor and kidney showed increased activity in the DMBA induced animals. Serum urokinase, -like plasminogen activator (u-PA) was also increased in animals with tumor, indicating tumor invasion. Administration of quercetin caused a significant decrease of both t-PA and u-PA. In conclusion, the present study suggests the possible role of quercetin in primary and invasive mammary tumor treatment. The above observations in vivo warrant further studies, due to the easy availability, common occurrence and low toxicity of this dietary bioflavonoid.

[Concentration and activity of cathepsin D in the blood plasma and serum of patients with abdominal aortic aneurysm]

Concentration and activity of cathepsin D are markedly higher in the blood plasma of patients with abdominal aortic aneurysm than in the blood plasma of healthy subjects. The difference results from release of big amounts of procathepsin D and increased release of the active enzyme into circulating blood of patients with aortic aneurysm. Concentration and activity of cathepsin D in the blood serum of patients with aortic aneurysm are also higher than in the serum of healthy subjects. Concentration and activity of cathepsin D are markedly higher in the blood serum of patients with aortic aneurysm and in healthy subjects as compared to the blood plasma. The difference is due to the release of marked amounts of procathepsin D and cathepsin D from morphotic elements in vitro during blood coagulation and clot retraction.

Activity of cathepsin D and alpha(1)-antitrypsin in the blood serum of patients with mammary carcinoma

THE AIM of this study was to determine the activity of cathepsin D and alpha(1)-antitrypsin in the blood serum of patients with mammary carcinoma.

PATIENTS AND METHODS

The study was conducted on 52 women operated for a unilateral breast tumor, divided into two groups, according to the number of metastases and tumor size. Cathepsin D activity was determined using the method of Anson, while alpha(1)-antitrypsin activity was determined according to the Eriksson method.

RESULTS

Both groups of patients with mammary carcinoma were found to have higher activity of cathepsin D before the treatment compared to healthy females. After the surgery the enzyme activity increased significantly, whereas 6 months after the surgery it generally decreased. The activity of alpha(1)-antitrypsin was significantly lower in patients before the treatment than in the controls, while after 6 months an increase in alpha(1)-antitrypsin activity was observed. The correlation between activity of cathepsin D and alpha(1)-antitrypsin was revealed. High enzyme activity and low alpha(1)-antitrypsin activity may result from the stage of neoplastic transformation.

CONCLUSION

The determination of cathepsin D activity together with alpha(1)-antitrypsin activity may serve as useful biochemical marker in monitoring of malignant changes in breast tumor.

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.

Evaluation of serum cathepsin B and D in relation to clinicopathological staging of colorectal cancer

AIM: Proteolytic degradation of the extracellular matrix facilitates cancer invasion and promotes metastasis. The study aims at evaluation of preoperative and postoperative serum cathepsins B and D levels in correlation with selected anatomoclinical features of colorectal cancer.

METHODS: Blood samples were collected from 63 colorectal cancer patients before curative operation of the tumor 10 d later. Blood that was obtained from 20 healthy volunteers, served as a control. The activity of cathepsin B was measured with Bz-DL-arginine-pNA as a substrate at pH 6.0, while cathepsin D activity was determined with urea-denatured hemoglobin (pH 4.0).

RESULTS: The preoperative and postoperative activities of cathepsin B were significantly (P < 0.00001) lower in serum of colorectal cancer patients than in control group. However, postoperative values of this protease were significantly increased in comparison with preoperative ones (P = 0.031). Activity of cathepsin D appeared to be significantly higher in colorectal cancer sera (P < 0.00001) compared with controls. No statistically significant differences between preoperative and postoperative activity of cathepsin D were noted (P = 0.09). We revealed a strong linkage of cathepsins’ levels with lymph node status and pT stage of colorectal cancer.

CONCLUSION: Blood serum activities of cathepsin B and D depend on the time of sampling, tumor size and lymph node involvement. Significantly, increased activity of cathepsin D could indicate a malignant condition of the large intestine. In our work, the serum postoperative decrease of cathepsin B activity appears as an obvious concomitant of local lymph node metastasis-the well-known clinicopathological feature of poor prognosis.

Cathepsin D is a potential serum marker for poor prognosis in glioma patients

Cathepsin D is an aspartyl protease involved in protein catabolism and tissue remodeling which can be secreted from cancer cells. To identify a potential serum marker for gliomas, we investigated the gene expression levels of cathepsin D in 87 tissue samples and measured the protein concentrations in sera of glioma patients. The tissue samples consisted of 43 glioblastomas, 13 anaplastic astrocytomas, 22 astrocytomas, and 9 normal brain tissues. The results of real-time quantitative reverse transcription-PCR analysis showed that cathepsin D transcript levels became significantly higher as the glioma grade advanced (P = 0.0466, glioblastoma and anaplastic astrocytoma; P = 0.0008, glioblastoma and astrocytoma; P = 0.0271, glioblastoma and normal brain tissue; unpaired t test). Immunohistochemical analysis with anti-cathepsin D antibody revealed dense and spotty staining in the tumor cells with high transcript levels. The low expression of cathepsin D significantly correlated with long survival of the glioma patients. Furthermore, the glioblastoma patients with high gene expression of cathepsin D lived significantly shorter than those with low expression (P = 0.0104, Cox-Mantel log-rank test) and frequently had leptomeningeal dissemination (P = 0.0016, chi2 test). The multivariate analysis confirmed that the cathepsin D expression level was an independent predictor for short survival (P = 0.0102, Cox proportional hazard regression model). Measurement of the serum cathepsin D concentrations by ELISA showed a significant increase in the patients with high-grade gliomas as compared with the low-grade tumors (P = 0.0081, chi2 test). These results collectively suggest that cathepsin D could be a potential serum marker for the prediction of aggressive nature of human gliomas.

[Cancer procoagulant and cathepsin D activity in blood serum in patients with bladder cancer]

The increasing morbidity and mortality rates of bladder cancer forced the scientists to search for new unfailing diagnostic and therapeutic methods that will improve treatment effects. There are biochemical cancer markers as cancer procoagulant (CP) and cathepsin D which may be used to this end. The aim of the study was to evaluate the activity of the cancer procoagulant and cathepsin D in the blood serum in patients with superficial bladder cancer. The venous blood samples were from 15 patients with microscopically proved superficial bladder carcinoma (i.e. study group) and 15 normal volunteers as a control group. The serum blood CP activity was determined by the Gordon-Benson's coagulation method and expressed by the clotting time in seconds (s) while the cathepsin D activity was determined by the Folin-Ciocalteau's method and expressed by a quantity of released tyrosine in nmol/ml per 4 hours. The CP activity in serum of patients with superficial bladder cancer was increased in statistically way as compared to the non-cancer controls (p<0.0001). The cathepsin D activity in blood serum of the study group was also enhanced as compared to the control group and the said values differed statistically (p<0.0351). It appears to be justifiable to apply the determination of the CP and cathepsin D activity in blood serum for the diagnostics of superficial bladder cancer.

Oxidative imbalance and cathepsin D changes as peripheral blood biomarkers of Alzheimer disease: A pilot study

Markers of oxidative stress in peripheral blood from patients with Alzheimer disease (AD) were analyzed. Thirty-three AD patients were recruited. Plasma antioxidant power (AOP), plasma Cystatin C as well as Cathepsin D in PBL were evaluated. We found that the AOP levels were significantly decreased in AD patients if compared to healthy donors, while the plasma level of Cystatin C was significantly higher. Importantly, a significantly decreased expression of Cathepsin D in PBL was also observed. These results suggest that oxidative imbalance in the peripheral blood of AD patients could mirror oxidative changes previously described in the central nervous system.

Characterization and enumeration of cells secreting tumor markers in the peripheral blood of breast cancer patients

In the process of metastasis, malignant cells are released from the primary tumor and migrate to specific organs via the lymphatic and blood circulation systems. These circulating tumor cells have been characterized by immunochemistry, the reverse transcription-polymerase chain reaction, and flow cytometry. Using the MCF-7 breast cancer cell line, we have developed a two-color ELISPOT assay to detect cells secreting cathepsin D protease and MUC1 glycoprotein, markers associated with the risk of metastases in breast cancer. The threshold of detection of this ELISPOT assay was one cathepsin D- or MUC1-secreting MCF7 cell per 5 ml of control blood. In 16 patients with breast carcinoma metastases, 1 to 1940 cathepsin D- or MUC1-secreting cells per 2x10(7) PBMC were enumerated, whereas none were found in 11 controls. Moreover, in six patients 6-60% of MUC1-secreting cells also expressed the CXCR4 chemokine receptor, which is involved in the homing of metastatic breast cancer cells. The ELISPOT assay described here allowed us to enumerate cathepsin D- and/or MUC1-secreting cells in the MCF-7 cell line and in the peripheral blood of patients with disseminated breast cancer. The combination of the ELISPOT assay and CXCR4-positive cell sorting identified subsets of MUC1-secreting cells in the peripheral blood of these patients.

Preeclampsia-associated reduction of cathepsin D activity in the umbilical cord

BACKGROUND

Preeclampsia is accompanied by an increase of collagen contents in the umbilical cord (UC) arteries and in Wharton's jelly. Cathepsin D is one of the enzymes which participates in collagen degradation and activates precursor forms of collagenolytic metalloproteinases. It was decided to evaluate the activity of cathepsin D within umbilical cord arteries, veins and Wharton's jelly and its alterations in preeclampsia.

MATERIALS AND METHODS

Umbilical cord components were separated and submitted to homogenisation/extraction with 0.05 M Tris-HCl+0.2% Triton X-100, pH 7.5. Proteolytic activities of the extracts were studied with a use of cathepsin D-specific substrate. Western immunoblot technique was employed to detect this enzyme.

RESULTS

It was found that human umbilical cord tissues contain both active and inactive forms of cathepsin D. Preeclampsia is associated with a distinct increase in the amount of this enzyme in the umbilical cord, whereas its activity deeply decreased. Activation with trypsin augments cathepsin D activity in preeclamptic umbilical cord to the values observed in control arteries or even exceeds the control values (veins, Wharton's jelly).

CONCLUSIONS

Preeclampsia is associated with a reduction in the activity of cathepsin D in human umbilical cord. The low activity of cathepsin D may reduce collagen degradation and enhance its accumulation in the umbilical cord, especially in the arteries. Similar changes in other foetal blood vessels may result in an increase of vascular resistance and hypertension, which may persist after birth.

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.

Plasma cathepsin D isoforms and their active metabolites increase after myocardial infarction and contribute to plasma renin activity

Plasma renin activity (PRA) is often found to increase after myocardial infarction (MI). Elevated PRA may contribute to increased myocardial angiotensin II that is responsible for maladaptive remodeling of the myocardium after MI. We hypothesized that MI would also result in cardiac release of cathepsin D, a ubiquitous lysosomal enzyme with high renin sequence homology. Cathepsin D release from damaged myocardial tissue could contribute to angiotensin formation by acting as an enzymatic alternate to renin. We assessed circulating renin and cathepsin D from both control and MI patient plasma (7-20 hours after MI) using shallow gradient focusing that allowed for independent measurement of both enzymes. Cathepsin D was increased significantly in the plasma after MI (P < 0.001). Furthermore, circulating active cathepsin D metabolites were also significantly elevated after MI (P < 0.04), and contained the majority of cathepsin D activity in plasma. Spiking control plasma with cathepsin D resulted in a variable but significant (P = 0.005) increase in PRA using a clinical assay. We conclude that 7-20 hours after MI, plasma cathepsin D is significantly elevated and most of the active enzymatic activity is circulating as plasma metabolites. Circulating cathepsin D can falsely increase clinical PRA determinations, and may also provide an alternative angiotensin formation pathway after MI.

Changes of balance between proteinase and their inhibitors in blood of pigs with high-velocity missile wounds

OBJECTIVE

To study the effect of imbalance between lysosomal enzymes and their inhibitors in blood on disturbance of the local and whole body after trauma.

METHODS

The dynamic changes of lysosomal enzymes and proteinase inhibitors were studied in 12 pigs with femoral comminuted fractures in both hind limbs caused by high velocity missiles. Four normal pigs served as controls.

RESULTS

After injury, the activity of Cathepsin D in arterial plasma increased gradually and reached the highest level at 8 hours, acid phosphatase in serum began to increase at 12 hours and the value of serum elastase did not change significantly. The level of alpha1-antitrypsin, a proteinase inhibitor in plasma, decreased significantly in the early stage after injury [73.5%+/-6.4% and 81.0%+/-5.1% of the baseline value (1.67 micromol x ml(-1) x min(-1)+/- 0.29 micromol x ml(-1) x min(-1)) at l and 2 hours after injury, respectively, P<0.05], then increased gradually and was higher than the baseline value at 12 hours after injury.

CONCLUSIONS

Imbalance between lysosomal enzymes and proteinase inhibitors occurs soon after injury, which might result in continuous tissue damage and play an important role in the disturbance of general reaction after injury.

[Lysosomal enzymes of the liver and kidney in unspecific purulent kidney disease]

Unspecific inflammatory lesions of the urinary tract are known to be a vital question in urology and nephrology of our country and in foreign ones. Used in experiments were rats of mixed population. Lysosomal enzymes were studied in homogenates of the liver and contralateral kidney tissues and in the blood serum as well 1, 3, 6 days after simulation of the pathology experimental model. Activities were measured of such lysosomal enzymes as acid DNA-ase and RNA-ase, cathepsin, and acid phosphatase. Results of the studies made showed that in unspecific purulent affection of the kidneys there occurs an activation of acid blood hydrolases followed by their activation in the liver. The contralateral kidney, because of it being linked in functioning with the liver, remains relatively "inert" with respect to activation of lysosomal enzymes.

Prediction of the extent of prostate cancer by the combined use of systematic biopsy and serum level of cathepsin D

BACKGROUND

The objective of this study was to assess the usefulness of combined systematic prostate biopsy with the serum level of cathepsin D, which has recently been shown to be a useful marker for prostate cancer, to predict the disease extension.

METHODS

Seventy-two patients with clinically organ-confined disease who underwent radical prostatectomy were evaluated for serum prostate-specific antigen (PSA) and cathepsin D levels, systematic biopsy, and pathological stage.

RESULTS

The incidence of extraprostatic disease in patients with more than half the biopsy cores positive or > or = 15 ng/mL cathepsin D was significantly higher than that in patients with less than half the biopsy cores positive or < 15 ng/mL cathepsin D, respectively; whereas cancer in bilateral lobes or > or = 10 ng/mL PSA could not be used as a predictor of extraprostatic disease. Furthermore, in patients with more than half the biopsy cores positive and > or = 15 ng/mL cathepsin D or those with more than half the biopsy cores positive and > or = 10 ng/mL PSA, extraprostatic disease was significantly more common than in those with less than half the biopsy cores positive and < 15 ng/mL cathepsin D or those with less than half the biopsy cores positive and < 10 ng/mL PSA, respectively. Furthermore, the prediction of the incidence of extraprostatic disease using these three variables was significantly more accurate than using two of the variables (percentage positive biopsy cores plus serum cathepsin D or PSA).

CONCLUSION

Systematic biopsy together with serum cathepsin D and/or PSA was a useful predictor of the extent of prostate cancer. Patients with more than half the biopsy cores positive, > or = 15 ng/mL cathepsin D and/or > or = 10 ng/mL PSA could avoid prostatectomy because there is a significantly high probability that they already have extraprostatic disease.

Serum cathepsin D and its density in men with prostate cancer as new predictors of disease progression

We examined whether serum levels of cathepsin D (CatD) and its density (CatD-D), which was determined by dividing the serum levels of CatD by the prostate volume, could be used as predictors of the progression and prognosis in patients with prostate cancer. Serum levels of CatD in 40 healthy controls, 70 patients with benign prostatic hypertrophy (BPH) and 80 patients with prostate cancer were measured by a sandwich enzyme immunoassay, and prostate volume was measured using transrectal ultrasonography. The mean levels of CatD and CatD-D in patients with prostate cancer were significantly higher than those in healthy controls and patients with BPH. Furthermore, the CatD and CatD-D levels in prostate cancer patients with metastasis were significantly elevated compared with those in patients without metastasis. Among patients who underwent radical prostatectomy, the levels of CatD and CatD-D in patients with pathologically organ-confined disease were significantly lower than in those with extraprostatic disease. However, the elevated levels of CatD and CatD-D were not significantly associated with the cause-specific survival in prostate cancer patients. These findings suggest that the elevation of CatD or CatD-D could be used as new predictors of disease progression, but not prognosis, in patients with prostate cancer.

Ozone therapy and the activity of selected lysosomal enzymes in blood serum of patients with lower limb ischaemia associated with obliterative atheromatosis

BACKGROUND

The paper compares the effects of ozone therapy and conventional balneological methods on health condition of patients with obliterative atheromatosis and on serum activity of three lysosomal enzymes.

MATERIAL/METHODS

Sixty-four patients with lower limb ischaemia in the course of obliterative atheromatosis (without diabetes) were enrolled in the study. Thirty-two patients were treated with ozone administered by intravenous infusions and 30-minute aerosol oxygen-ozone baths. A comparative group was formed of 32 patients treated with traditional balneology. There was also a control group made up of 30 healthy subjects. Ozone therapy as well as traditional balneology were administered daily for the period of 10 days, excluding Saturdays and Sundays. Blood for biochemical analysis was collected from elbow vein in the following time intervals: 24 hours before ozone therapy or classical balneology, one hour after therapy and on the 10th day of treatment. The activity of cathepsin D, acid phosphatase and arylsulphatase as well as the levels of a-1-antitrypsin (protease inhibitor) were determined in blood serum of patients with obliterative atheromatosis.

RESULTS

In patients who received ozone therapy the activity of analysed lysosomal hydrolases returned to the values typical for healthy subjects. Patients' general condition also improved. The use of traditional balneological methods did not result in any significant change either in the activity of lysosomal hydrolases, the level of a-1-antitrypsin or general condition of patients.

CONCLUSIONS

Ozone therapy administered by intravenous infusions and aerosol oxygen-ozone baths of lower extremities yields much better therapeutic results in comparison with classical balneology.