Serum prolidase activity in ankylosing spondylitis and rheumatoid arthritis

Prolidase as a marker of fibrogenesis in idiopathic primary ovarian insufficiency

OBJECTIVES

To evaluate the serumlevel of prolidase,which isa marker of fibrogenic activity, in women with idiopathic primary ovarian insufficiency (POI).

STUDY DESIGN

This is a prospective case-control study. Serum prolidase level was compared between the study group including 68 women with POI and control group including 65 normally menstruating women. Serum proline and hydroxyproline levels were also compared. Correlation analyses were performed between the prolidase level and POI related parameters including estradiol (E), follicle stimulating hormone (FSH), anti-mullerian hormone (AMH) levels, and presence of POI family history.

RESULTS

Serum prolidase and proline level were significantly increased in women with the diagnosis of POI compared to the control group (1082.57 (147.53) vs 981.13 (223.26) U/L, 233.30 (83.16) vs 218.94 (82.59) µmol/L, respectively). Prolidase level found to have significant correlations with AMH, E, FSH levels, and presence of POI family history (r = -0.49, p = 0.001; r = -0.39, p = 0.001; r = 0.42, p = 0.001; r = 0.22, p = 0.01; respectively). In receiver operating characteristics analysis, prolidase was shown to be a discriminative factor for POI at 1031.14 U/L cut-off value with 75 % sensitivity and 65 % specificity. Thearea under curve was 0.71 [(95 % CI: 0.62-0.79), p = 0.001].

CONCLUSION

The current study revealed increased prolidase level in women withPOI. Serum prolidase level was also negatively correlated with the serum AMH level. Considering the present findings,prolidase may be a candidate molecule in assessment of POI cases.

Oxidative Stress and Musculoskeletal Pain in University Students with Generalized Joint Hypermobility: A Case-Control Study

Objective

The current case–control study aimed to evaluate generalized joint hypermobility (GJH) and its association with pain intensity, cellular oxidative stress, and collagen-associated disorders in university students aged 18–25 years old.

Background

Joint hypermobility has been recognized in healthy subjects and people who are carriers of cellular disorders in connective tissues. Cellular tissue oxidative stress and collagen-associated disorders were shown to be associated with joint hypermobility (JH).

Materials and Methods

A total of 300 university students aged 18–25 years were randomly invited from different medical and science faculties in Mansoura university, Mansoura, Egypt to participate in this case–control study. Only 280 university students who had no exclusion criteria like chronic health problems, physical disability, musculoskeletal disorders, and body mass index (BMI) of ≥25 underwent an initial clinical interview and Beighton scoring as measures of GJH. Pain intensity, physical activity, oxidative stress parameters; TAC, TOC, OSI, and collagen-associated parameters; cellular prolidase activity and hydroxyproline were evaluated by using a prevalidated questionnaire, colorimetric, and immunoassay techniques.

Results

GJH was significantly reported in 57.1% of the study population, and most of them are females. Compared to men, females with GJH showed poor physical activity, lower TAC, and significantly higher levels of TOC, OSI, cellular prolidase activity, and hydroxyproline. Based on our findings, a high Beighton score is closely related to the tissue levels of prolidase, hydroxyproline, antioxidant activity, pain intensity, and poor physical activity in the female with GJH compared to men.

Conclusion

GJH was significantly reported in 57.1% of the study population, and most of them are females. The incidence of GJH showed to be associated with poor physical activity, abnormal cellular oxidative stress, and collagen abnormalities measured by significant increase in change in cellular prolidase activity and hydroxyproline.

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.

Prolidase - A protein with many faces

Prolidase is a metal-dependent peptidase specialized in the cleavage of dipeptides containing proline or hydroxyproline on their C-termini. Prolidase homologues are found in all kingdoms of life. The importance of prolidase in human health is underlined by a rare hereditary syndrome referred to as Prolidase Deficiency. A growing number of studies highlight the importance of prolidase in various other human conditions, including cancer. Some recent studies link prolidase's activity-independent regulatory role to tumorigenesis. Furthermore, the enzyme or engineered variants have some applications in biotechnology. In this short review, we aim to highlight different aspects of the protein the importance of which is increasingly recognized over the last years.

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.

Evaluation of serum prolidase activity and oxidative stress in patients with temporomandibular joint internal derangement

Objective: To investigate serum prolidase activity and oxidative stress in patients with temporomandibular joint internal derangement (TMJ-ID).Methods: Seventy patients with Wilkes stage III, IV, and V joints and 70 healthy controls were included. Serum prolidase activity and oxidative stress parameters, including total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), advanced oxidation protein products (AOPP), glutathione (GSH), ferric reducing antioxidant power (FRAP), and lipid hydroperoxide (LOOH) were measured.Results: The levels of prolidase, TOS, OSI, AOPP, and LOOH were significantly higher in the TMJ-ID group than in the control (p = .0001). TAS and FRAP level was significantly lower in the TMJ-ID group than in the control (p = .0001). There was no significant difference in GSH between groups.Conclusion: Significantly increased prolidase activity and oxidative stress in patients with TMJ-ID may be related to long-term collagen tissue damage, and inflammation and can be effective in the etiology of TMJ-ID.

Serum prolidase activity in systemic sclerosis

Systemic sclerosis, also known as scleroderma, is a complex systemic inflammatory autoimmune disease that targets the vasculature and connective tissue-producing cells and components of the innate and adaptive immune systems. The disease is characterized by a hardening of the skin and an increased synthesis of collagen . Prolidase is a specific imidodipeptidase involved in collagen degradation. The aim of this study was to search the serum prolidase activity (SPA) in the two subtypes of systemic sclerosis: diffuse and limited cutaneous systemic sclerosis. For this purpose, 35 patients diagnosed with systemic sclerosis (24 diffuse and 11 limited) and 41 healthy control subjects were included in the study. SPA was determined using Myara's method, which is a modification of Chinard's method. SPA did not differ between the scleroderma patients and controls (p = 0.467). However, SPA was significantly lower in diffuse form than in both limited form and control subjects (p = 0.021 and p = 0.024, respectively). SPA also did not differ between the limited form and control subjects (p = 0.145). Scleroderma is characterized by excessive deposition of collagen and tissue fibrosis due to the reduced collagen degradation. SPA is reduced in scleroderma patients, especially in diffuse form. Circulating autoantibodies, oxidative stress, and decreased physical activity may contribute to this process.

Serum prolidase level in ankylosing spondylitis: low serum levels as a new potential gold standard biomarker for disease activity

Ankylosing spondylitis (AS) is a chronic inflammatory disorder that mainly affects the sacroiliac joints and axial skeleton. The aim of this study was to assess serum prolidase level (SPL) and its association with disease activity in patients with AS. This prospective study included 75 AS patients. Thirty age- and gender-matched healthy controls were enrolled. AS patients were considered as active if BASDAI score was ≥4 or inactive if BASDAI score was <4. There were 34 AS patients in the active group and 41 AS patients in the inactive group. Anti-TNF-monoclonal antibody treatment was started in patients in the active group. These active patients were reassessed 6 months later. BASDAI, ASDAS, visual analogue scale, short-form-general health survey questionnaire, C-reactive protein, erythrocyte sedimentation rate and SPL were measured in all AS patients before and after treatment. The SPL was significantly lower in inactive AS patients than in control group, and also, SPL was significantly lower in active AS patients than in inactive patients. All activity parameters were successful in separating active and inactive AS patients. However, the only parameter that could distinguish active patients from inactive patients was prolidase. The optimum cutoff point of SPL to identify patients with active AS was 23.13 ng/mL with sensitivity, specificity, positive predictive value and negative predictive value of 100 %. Serum prolidase level was successful in measuring disease activity and had as high sensitivity and specificity as BASDAI and was superior to other activity parameters.

Systemic Prolidase Activity and Oxidative Stress in Keratoconus

AIM

Our aim was to evaluate the serum prolidase activity, total antioxidant capacity (TAC) and total oxidant status (TOS) in patients with keratoconus.

MATERIAL AND METHOD

A total 69 keratoconus patients and 72 control subjects with similar age and gender were evaluated within the scope of this study. The keratoconus group was divided into four stages with the modified Krumeich classification. Serum prolidase activity, TAC and TOS were measured and compared between the patient and control groups.

RESULTS

The median serum prolidase enzyme activity value was 528.3 (684.1-416.7) U/L in the keratoconus group and 606.2 (812.9-482.3) U/L in the control group. The difference between the groups was statistically significant (p = 0.027). The median TAC value was 1.24 (1.37-1.05) mmol/L in the keratoconus group and 1.29 (1.38-1.18) mmol/L in the control group. The median TOS value was 2 (4-1) μmol/L in the keratoconus group and 3 (4-2) μmol/L in the control group. There was no statistically significant difference between the two groups in terms of TAC or TOS (p = 0.113 and p = 0.366, respectively). There was a positive correlation between TAC and TOS in keratoconus group but not in the control group (r = 0.670, p = 0.001 and r = 0.141, p = 0.241, respectively). No significant relationship was seen between the keratoconus group stages and serum prolidase activity, TAS or TOS (p = 0.894, p = 0.155 and p = 0.381, respectively).

CONCLUSION

In conclusion, a significant relationship was found between decreased serum prolidase activity and keratoconus but there was no significant relationship between keratoconus and serum TAC or TOS.

Serum prolidase activity and oxidant-antioxidant status in children with chronic hepatitis B virus infection

BACKGROUND

Chronic hepatitis B (CHB) is a global health problem that can result in serious complications associated with collagen degradation. Prolidase is a specific imidodipeptidase that plays an important role in the breakdown of collagen. The aim of this study was to investigate prolidase activity and oxidant-antioxidant status in children with CHB.

METHODS

This prospective case control study includes 38 patients with CHB, 31 patients with inactive hepatitis B (IHB), and 29 healthy matched control subjects. Serum prolidase enzyme activity (SPEA), total antioxidant capacity (TAC), total oxidative activity (TOA), and malondialdehyde (MDA) level were measured and oxidative stress index (OSI) was calculated for each group.

RESULTS

Patients with CHB had significantly higher SPEA levels (207.82 ± 186.80 IU/L) than did the controls (58.6 ± 38.1 IU/L) and IHB patients (67.1 ± 39.9) (p < 0.001). CHB patients also had significantly higher TOA (45.0 ± 19.9 vs. 29.4 ± 11.7 (μmolH2O2 Eq./L), p = 0.005), OSI (33.1 ± 21.4 vs. 17.5 ± 10.2, p = 0.002) and MDA (13.4 ± 4.0 vs. 7.8 ± 2.6 μm/L, p < 0.001) values compared with the controls. TOA (32.0 ± 10.0) and OSI (15.4 ± 11.0) values of IHB patients were significantly lower than those of CHB patients (p < 0.05). SPEA had significant correlations with HBV- DNA and ALT values (r =0.514 and r =0.454, p < 0.001).

CONCLUSION

Our results suggest that prolidase activity can be considered as a reliable marker for CHB and increased oxidative stress appears to be related to chronicity of the disease.