Serum prolidase activity in patients with pulmonary tuberculosis

Prolidase could be considered a sign of inflammation associated with cigarette smoking

Objectives

Smoking causes inflammation, thickening, and narrowing of the airways. This inflammatory process is a reaction to free radicals and oxidants. Smoking affects collagen metabolism and tissue remodeling. Prolidase enzyme hydrolyzes iminodipeptides with hydroxyproline and C terminal proline. It plays a crucial role in the metabolism of collagen and the remodeling of the matrix. The present study aims to reveal the association of prolidase with inflammation caused by smoking and to compare serum prolidase levels with oxidative-antioxidative status in healthy individuals.

Methods

A total of 76 participants (38 smokers and 38 nonsmokers) were involved in the present study. Serum cotinine levels were measured to show the exposure to nicotine in tobacco smoke by using the competitive inhibition enzyme immunoassay method. Serum prolidase, total oxidant status (TOS), and total antioxidant status (TAS) were determined by the enzyme-linked immunosorbent (ELISA) method, respectively. The correlation between smoking, serum prolidase levels, TOS, and TAS was investigated.

Results

TAS and serum prolidase levels of smokers were considerably lower than those in non-smokers (p < 0.001, p = 0.012 respectively). However, no differences were observed in TOS between the two groups. There was no statistically significant correlation between serum prolidase levels, TAS, and TOS. Moreover, no relationship was observed between respiratory function parameters and serum prolidase levels.

Conclusion

To the best of our knowledge, the present study is the first study to demonstrate the role of prolidase in smoking-related inflammation. The results achieved in the present study suggest that smoking creates an imbalance in the oxidant-antioxidant activity. Smoking decreases prolidase levels, leading to decreased collagen turnover. Chronic pulmonary disease might be related to this decrease in collagen turnover.

PROLIDASE: A Review from Discovery to its Role in Health and Disease

Prolidase (peptidase D), encoded by the PEPD gene, is a ubiquitously expressed cytosolic metalloproteinase, the only enzyme capable of cleaving imidodipeptides containing C-terminal proline or hydroxyproline. Prolidase catalyzes the rate-limiting step during collagen recycling and is essential in protein metabolism, collagen turnover, and matrix remodeling. Prolidase, therefore plays a crucial role in several physiological processes such as wound healing, inflammation, angiogenesis, cell proliferation, and carcinogenesis. Accordingly, mutations leading to loss of prolidase catalytic activity result in prolidase deficiency a rare autosomal recessive metabolic disorder characterized by defective wound healing. In addition, alterations in prolidase enzyme activity have been documented in numerous pathological conditions, making prolidase a useful biochemical marker to measure disease severity. Furthermore, recent studies underscore the importance of a non-enzymatic role of prolidase in cell regulation and infectious disease. This review aims to provide comprehensive information on prolidase, from its discovery to its role in health and disease, while addressing the current knowledge gaps.

Role of prolidase activity and oxidative stress biomarkers in unexplained infertility

OBJECTIVE

Our aim was to explore the significance of serum prolidase enzyme activity and oxidative stress in women with unexplained infertility (UEI).

METHODS

In this case-control study (n = 160; 86 cases; 74 controls) prolidase enzyme activity and total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and vitamin E were measured in plasma using enzyme-linked immunosorbent assays.

RESULTS

Prolidase enzyme activity and TAS levels were particularly higher in the patient group (P = 0.013, P = 0.001, respectively). Decreased OSI levels were detected in the patient group (P = 0.001). There was a positive relationship of prolidase with vitamin E in both patient and control groups (r = 0.892, P = 0.001, and r = 0.659, P = 0.001, respectively). A positive, but weak, relationship was identified between prolidase activity and TOS levels and also between vitamin E and TOS levels in the UEI group (r = 0.265, P = 0.049, and r = 0.288, P = 0.014, respectively). No association was found between prolidase and TOS levels or between vitamin E and TOS levels in the control group (r = 0.0097, P = 0.527, and r = 0.085, P = 0.610, respectively).

CONCLUSION

Our results showed an association between serum prolidase activity and oxidative stress in UEI patients. Further studies including greater groups are required to show the role of reactive oxygen species in UEI.

High prolidase levels in patients with Familial Mediterranean Fever (FMF)

Introduction. Familial Mediterranean Fever (FMF) is an autoinflammatory disease. Prolidase is a specific imidodipeptidase that plays a role in collagen degradation, and an important role in inflammation and wound healing. Hypoxia-inducible factor-1α (HIF-1) is an important protein in the regulation of immunological response, hemostasis, vascularization. The aim of the study was to compare serum prolidase and HIF-1α levels in patients with FMF in attack-free period and healthy control group.

Methods. Between August 2017 and December 2017, sixty patients diagnosed with FMF according to the criteria of the Tel-hashomer and admitted to Sivas Cumhuriyet University Medical Faculty, Internal Medicine Rheumatology Department and sixty healthy volunteers were enrolled in the study.

Results. Median serum prolidase levels were 72.1 (25.1–114.9) ng/ml in FMF group and 30.7 (21.3–86.2) ng/mL in healthy control (HC) group (p = 0.018). ROC analysis showed that the sensitivity was 65% and the specificity was 68.3% at serum prolidase levels 54.03 ng/mL (p < 0.05). The median serum levels of HIF-1α in the FMF group was 482.0 (292.0–3967.0) pg/mL and 632.0 (362.0–927.0) pg/mL in the HC group (p > 0.05). There was no significant correlation between laboratory findings, sex, age, and prolidase (p > 0.05).

Conclusion. Serum prolidase enzyme levels in FMF patients with attack-free period were significantly higher than in the HC group. However, the role of prolidase and HIF1-α in the FMF disease needs to be clarified with more extensive and comprehensive studies.

Serum prolidase level in patients with brucellosis and its possible relationship with pathogenesis of the disease: a prospective observational study

Background/aim

Changes in collagen metabolism and fibroblastic activity may play a role in the pathogenesis of brucellosis. The prolidase enzyme plays an important role in collagen synthesis. We aimed to investigate the association of prolidase levels with brucellosis.

Materials and methods

Serum prolidase levels in 20 patients newly diagnosed with brucellosis were compared with levels in 30 healthy control subjects. Patients with brucellosis were reassessed 3 months later for prolidase, other laboratory measurements, and response to treatment.

Results

The levels of serum prolidase were significantly higher in brucellosis patients compared with those of healthy controls. Prolidase, sedimentation, and C-reactive protein levels were significantly lower after antibrucellosis treatment than before treatment.

Conclusion

The current study is the first to demonstrate significantly increased serum prolidase levels in patients with brucellosis compared with healthy controls. Prolidase levels also significantly decreased with antibrucellosis treatment. This finding provides a new experimental basis to understand the pathogenesis of brucellosis in relation to collagen metabolism. The increase in serum prolidase levels might be related to several factors such as tissue destruction, increased fibroblastic activity, and granuloma formation, all of which are involved in the natural history of brucellosis.

Serum complement C4b, fibronectin, and prolidase are associated with the pathological changes of pulmonary tuberculosis

Background

Mycobacterium tuberculosis infection can activate the immune system, leading to characteristic pathological changes such as inflammatory granuloma, caseous necrosis, and cavity formation.

Methods

Clinical data of 187 cases of pulmonary tuberculosis (PTB) were analyzed using statistical methods, while serum levels of complement C4b (C4b), fibronectin (FN), and prolidase (PEPD) were detected using the ELISA method among the control, minimal PTB, moderate PTB, and advanced PTB groups.

Results

We found significantly higher levels of serum C4b and PEPD (P = 0.018, P = 0.003), and significantly lower levels of serum FN (P < 0.001) in PTB patients. Furthermore, the serum levels of 3 proteins were significantly different among 3 PTB groups. FN level was significantly higher in the moderate PTB group, compared with patients in the minimal and advanced PTB groups (P < 0.05, P < 0.01). PEPD level was significantly higher in the moderate PTB group, compared with the minimal PTB group (P < 0.05). Analysis of clinical data showed that serum albumin, C-reactive protein (CRP), prealbumin, and C4 were significantly higher (P < 0.05), while serum globulin was significantly lower in patients with PTB (P < 0.001). A significant negative correlation was found between C4b and albumin, prealbumin. On the other hand, a significant positive correlation was found between C4b and globulin, CRP, PEPD, as well as between PEPD and CRP (P < 0.05).

Conclusions

Our study showed that C4b, FN, and PEPD are associated with tissue damage, granuloma formation, and cavity formation, respectively, in patients with PTB. The present study provides a new experimental basis to understand the pathogenesis and pathological changes of PTB.

Serum prolidase activity in diabetic foot ulcers

Impaired wound healing is an important problem in diabetes mellitus; however, its pathogenesis remains unclear. We aimed to evaluate serum prolidase activity (SPA), an important marker of collagen turnover, in subjects with and without diabetic foot ulcers as compared with healthy controls. Twenty-seven patients with diabetic foot ulcers (foot ulcer group), 27 patients without diabetic foot ulcers (diabetic control group) and 27 healthy controls were enrolled. The study groups had similar age, sex distribution and body mass index. Metabolic and inflammatory parameters as well as SPA were determined. The diabetic foot ulcer group had significantly higher SPA (both p < 0.001) when compared with the diabetic and the healthy control groups. SPA showed a positive correlation with high-sensitive C-reactive protein and a negative correlation with high-density lipoprotein cholesterol levels (r = 0.313, p = 0.021 and r = -0.233, p = 0.036, respectively). No correlation was detected between SPA and glycaemic parameters. SPA appears to be higher in patients with diabetic foot ulcers when compared with patients without diabetic foot ulcers and healthy controls. The underlying mechanisms of elevated SPA and its clinical significance in predicting the natural course of wound healing in diabetic foot ulcers needs to be further evaluation.

Prolidase, matrix metalloproteinases 1 and 13 activity, oxidative-antioxidative status as a marker of preterm premature rupture of membranes and chorioamnionitis in maternal vaginal washing fluids

OBJECTIVE

Etiology of premature preterm rupture of membranes (PPROM) is not yet completely known and chorioamnionitis is one of the most important complications of its. We aimed to evaluate whether prolidase, matrix metalloproteinases, oxidative-antioxidative status, and inflammation markers in vaginal washing fluid (VWF) were associated with etiology of PPROM and whether these markers could be used to predict chorioamnionitis in PPROM.

STUDY DESIGN

This prospective case control study enrolled fifty pregnant women with PPROM and 50 healthy pregnant women. The VWF samples were taken at the time of admission in the PPROM group and patients were followed for chorioamnionitis. Prolidase, matrix metalloproteinases, oxidative-antioxidative status, and inflammation markers in VWF were assayed.

RESULTS

VWF levels of prolidase, matrix metalloproteinases 1-13 (p< 0.001), oxidative stress parameters, total oxidative stress (TOS) (p < 0.001) and oxidative stress index (OSI) (p = 0.002), and hs-CRP (p = 0.045) were significantly higher in the PPROM group than in the controls. Antioxidative status parameters, levels of paroxanase (PON-1) (p < 0.001) and total antioxidant capacity (TAC) (p < 0.001), were significantly lower in the PPROM group than in the controls. Mean VWF levels of prolidase (p < 0.001), metalloproteinases (p<0.05), and oxidative-antioxidative status parameters (p<0.05) were significantly different in women with versus women without chorioamnionitis in the PPROM group. Prolidase, MMP-13, TOS, TAC, and PON-1 were found as important predictors for chorioamnionitis in the PPROM group by the multivariate logistic regression analysis. When the ROC curve analysis for prolidase, MMP-13, TOS, TAC, and PON-1 were performed, all of them were statistically significant for area under the curve (areas under the curve were 0.94, 0.90, 0.80, 0.25, and 0.19, respectively).

CONCLUSIONS

This study showed that collagen turnover mediators, especially prolidase, and increased oxidative stress are significantly associated with PPROM. Also, chorioamnionitis can be predicted with prolidase, MMP-13, TOS, TAC, and PON-1 in PPROM patients.