Evaluation of the utility of serum prolidase as a marker for liver fibrosis

The Serum Prolidase Enzyme Activity as a Biomarker for Evaluation of the Subclinical Vascular Damage in Children with Epilepsy

Backgroud:

Epilepsy is a chronic medical condition requiring long term or even lifelong therapy. Various researches have shown that epilepsy patients have vascular risk factors such as abnormal lipids, insulin, elevated oxidative stress, chronic inflammation, and subclinical atherosclerosis.

Objectives:

The purpose of the present study was to determine serum prolidase enzyme activity as a biomarker in children taking antiepileptic drug treatment through comparison with control cases.

Materials and Methods:

The present study group consists of 61 children (20 females, 41 males) with epilepsy and a control group was formed of 32 healthy individuals (14 females, 18 males). Aspectrophotometric method was used to measure serum prolidase enzyme activity.

Results:

The epilepsy group demonstrated statistically significantly higher prolidase enzyme activity values when compared with the control group (P = 0.003). It was measured that the serum TOS and OSI values were significantly elevated in patients with epilepsy compared to controls (P < 0.001). However, serum TAS values were significantly lower in the epilepsy group than in the control group (P = 0.032).

Conclusions:

These results supported that epileptic patients taking the antiepileptic treatment had increased serum prolidase enzyme activity, suggesting that it may show an increased risk of subclinical vascular damage related to both chronic inflammation and fibrotic process associated with degenerated collagen turnover. Therefore, serum prolidase enzyme activity could be considered a useful biomarker for evaluation of the subclinical vascular damage in children with epilepsy on some antiepileptic drugs.

Relationship between renal tubulointerstitial fibrosis and serum prolidase enzyme activity

Objectives

The severity of interstitial fibrosis/tubular atrophy (IFTA) is the most important determinant of the irreversible progression of chronic kidney disease (CKD). Prolidase is the key enzyme in collagen turnover and is associated with an extracellular matrix increase. We aimed to evaluate the relationship between the presence and degree of IFTA and serum prolidase enzyme activity (SPEA) in patients undergoing a renal biopsy.

Methods

This cross-sectional study included 56 patients who underwent a renal biopsy (30 males; mean age 45.3 ± 16.8 years) and also 54 healthy volunteers (21 males; mean age 42.7 ± 8.2 years). IFTA scoring was performed on the basis of percentage of IFTA presence in renal biopsy tissues (1=<10%; 2=10–24%; 3=25–50%; 4=>50%). SPEA was measured by spectrophotometric method.

Results

The proteinuria and SPEA levels of the patients were significantly higher than the controls (p<0.001 and p<0.001, respectively). SPEA decreased significantly when the IFTA score increased (p<0.002). In the correlation analysis, the IFTA score was negatively correlated with SPEA (rs=−0.461, p<0.001), and positively correlated with proteinuria (rs=0.274, p=0.041).

Conclusion

These findings suggest that increased collagen turnover decreases over time concerning the progression of renal fibrosis. Monitoring of SPEA level may useful as a biomarker for early determination of CKD progression and severity.

Deiminated proteins and extracellular vesicles - Novel serum biomarkers in whales and orca

Peptidylarginine deiminases (PADs) are a family of phylogenetically conserved calcium-dependent enzymes which cause post-translational protein deimination. This can result in neoepitope generation, affect gene regulation and allow for protein moonlighting via functional and structural changes in target proteins. Extracellular vesicles (EVs) carry cargo proteins and genetic material and are released from cells as part of cellular communication. EVs are found in most body fluids where they can be useful biomarkers for assessment of health status. Here, serum-derived EVs were profiled, and post-translationally deiminated proteins and EV-related microRNAs are described in 5 ceataceans: minke whale, fin whale, humpback whale, Cuvier's beaked whale and orca. EV-serum profiles were assessed by transmission electron microscopy and nanoparticle tracking analysis. EV profiles varied between the 5 species and were identified to contain deiminated proteins and selected key inflammatory and metabolic microRNAs. A range of proteins, critical for immune responses and metabolism were identified to be deiminated in cetacean sera, with some shared KEGG pathways of deiminated proteins relating to immunity and physiology, while some KEGG pathways were species-specific. This is the first study to characterise and profile EVs and to report deiminated proteins and putative effects of protein-protein interaction networks via such post-translationald deimination in cetaceans, revealing key immune and metabolic factors to undergo this post-translational modification. Deiminated proteins and EVs profiles may possibly be developed as new biomarkers for assessing health status of sea mammals.

Deiminated proteins in extracellular vesicles and serum of llama (Lama glama)-Novel insights into camelid immunity

Peptidylarginine deiminases (PADs) are phylogenetically conserved calcium-dependent enzymes which post-translationally convert arginine into citrulline in target proteins in an irreversible manner, causing functional and structural changes in target proteins. Protein deimination causes generation of neo-epitopes, affects gene regulation and also allows for protein moonlighting. Furthermore, PADs have been found to be a phylogenetically conserved regulator for extracellular vesicle (EVs) release. EVs are found in most body fluids and participate in cellular communication via transfer of cargo proteins and genetic material. In this study, post-translationally deiminated proteins in serum and serum-EVs are described for the first time in camelids, using the llama (Lama glama L. 1758) as a model animal. We report a poly-dispersed population of llama serum EVs, positive for phylogenetically conserved EV-specific markers and characterised by TEM. In serum, 103 deiminated proteins were overall identified, including key immune and metabolic mediators including complement components, immunoglobulin-based nanobodies, adiponectin and heat shock proteins. In serum, 60 deiminated proteins were identified that were not in EVs, and 25 deiminated proteins were found to be unique to EVs, with 43 shared deiminated protein hits between both serum and EVs. Deiminated histone H3, a marker of neutrophil extracellular trap formation, was also detected in llama serum. PAD homologues were identified in llama serum by Western blotting, via cross reaction with human PAD antibodies, and detected at an expected 70 kDa size. This is the first report of deiminated proteins in serum and EVs of a camelid species, highlighting a hitherto unrecognized post-translational modification in key immune and metabolic proteins in camelids, which may be translatable to and inform a range of human metabolic and inflammatory pathologies.

Plasma prolidase levels as a biomarker for polycystic ovary syndrome

Aim: Assessment of plasma prolidase levels in polycystic ovary syndrome (PCOS). Patients & methods: PCOS patients were screened according to Rotterdam Criterion and prolidase levels were measured. Results: A total of 170 patients and 160 controls were recruited for the study and it was found that prolidase levels were significantly higher in PCOS group (991.10 ± 39.52) than control (621.89 ± 23.94). Furthermore it has been found that prolidase levels increase with the number of cysts in ovaries. Conclusion: Significant difference between prolidase levels in PCOS and control shows that it may be used as a diagnostic marker for disease. In addition to this, there is a positive correlation found between prolidase levels and number of cysts, hence may be used as a prognostic marker to monitor disease status.