Prolidase activity dysregulation and its correlation with oxidative-antioxidative status in chronic obstructive pulmonary disease

Lipid metabolism reprogramming in chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is a complex and diverse respiratory disorder, characterized by ongoing respiratory symptoms and restricted airflow. The major clinical manifestations typically encompass chronic cough, sputum production, and wheezing. The main pathological characteristics involve infiltration of inflammatory cells, overproduction of mucus, and damage to the alveolar walls. The underlying causes of COPD are complex and remain incompletely elucidated, thought to originate from the combined effect of various factors. Lipids, as hydrophobic molecules, fulfill three fundamental functions: energy storage, membrane biosynthesis, and signal transduction. Lipid metabolism is intricately intertwined with various metabolic pathways and plays a pivotal role in the complex pathogenesis of COPD. Delving into lipid metabolism, as well as the particular modifications and roles of lipid molecules in cells, is of paramount importance in the context of COPD. This review primarily aims to elucidate the role of fatty acid metabolism in the onset and progression of COPD. Additionally, it examines the potential of lipid metabolism reprogramming as a promising therapeutic approach, illuminating new paths for the management and treatment of this disabling respiratory condition.

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.

Stabil Kronik Obtrüktif Akciğer Hastalığı Hastalarında Serum Prolidaz ve Karbonik Anhidraz III Düzeylerinin Klinik Önemi

GİRİŞ: Kronik obstrüktif akciğer hastalığı (KOAH), geri dönüşümsüz hava yolu akış kısıtlaması ve kronik hava yolu iltihabı ile karakterize bir hastalıktır. Kollajen yıkımının bir göstergesi olan serum prolidaz enzimi ile asit-baz regülasyonunda önemli işlevi olan karbonik anhidraz (CA) III enziminin KOAH'lı hastalarda klinik önemini araştırmayı amaçladık. GEREÇ VE YÖNTEM: Bu çalışmaya 56 stabil KOAH'lı hasta ile sigara öyküsü ve ek hastalığı olmayan 32 sağlıklı olgu dahil edildi. Her iki grup arasında serum CA III ve prolidaz enzim düzeyleri karşılaştırıldı. BULGULAR: Prolidaz enzim düzeyleri açısından iki grup arasında istatistiksel fark bulunmadı (p=0.831). KOAH grubunda CA III düzeylerinde istatistiksel olarak anlamlı bir artış vardı (p=0.001). KOAH hastalarında CA III enzimi düzeyi ile kanda kısmi karbondioksit basıcı (pCO2) arasında orta derecede pozitif, kanda kısmi oksijen basıncı (pO2) arasında ise negatif korelasyon vardı (r:0.302, p&lt;0.025; r:-0.314, p:0.02). SONUÇLAR: CA III ile KOAH arasında önemli bir klinik ilişki olduğunu ve bu nedenle CA III'ün KOAH takibinde aday bir biyobelirteç olabileceğini düşünüyoruz.

Relationship between serum sialic acid levels and prolidase activity with airflow obstruction in patients with COPD

ABSTRACT

Our aim in this study was to evaluate the prognostic significance of sialic acid (SA) and prolidase activity and to evaluate the association between airflow obstruction severity and these parameters in chronic obstructive pulmonary disease (COPD) patients.Ninety-four patients (84 M, 10 F) and 34 healthy subjects (19 M, 15 F) were included into the study. COPD staging was performed to COPD patients according to new global initiative for chronic obstructive lung disease criteria which includes pulmonary function tests, symptoms and hospitalization; COPD patients were divided into 4 subgroups as group A (n = 25), group B (n = 19), group C (n = 20), and group D (n = 28).SA and C-reactive protein levels were significantly higher than the control group in all COPD groups. SA levels were significantly higher in group B patients than the control and group A. Prolidase activity was significantly lower than control group in total COPD groups (P < .05). There was a weak negative correlation between SA and forced vital capacity (r = -0.217, P = .038) and forced expiratory volume in 1 second (FEV1) (r = -0.210, P = .045), whereas weak positive correlation was present between SA and Creactive protein (r = 0.247, P = .018) in all patient groups. There was weak positive correlation between prolidase and FEV1 (r = 0.222, P = .033) and FEV1/forced vital capacity (r = 0.230, P = .027).Our study shows that systemic inflammation, prolidase activity, and SA levels in stable COPD patients are associated with airflow obstruction severity. In addition to the prolidase activity; SA levels might be associated with inflammation.

Methylprednisolone up-regulates annexin A1 (ANXA1) to inhibit the inflammation, apoptosis and oxidative stress of cigarette smoke extract (CSE)-induced bronchial epithelial cells, a chronic obstructive pulmonary disease in vitro model, through the formyl peptide receptor 2 (FPR2) receptors and the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway

Chronic obstructive pulmonary disease (COPD) is a progressive degenerative disease, of which smoking is the main causer. We carried out this study with the aim of exploring the underlying mechanism of methylprednisolone (MP) treating the COPD. To stimulate COPD in vitro, cigarette smoke extract (CSE)was employed to induce human bronchial epithelial cells BEAS-2B. With the help of MTT and Tunel assays, the viability and apoptosis of BEAS-2B cells after indicated treatment were assessed. The levels of inflammatory response and oxidative stress were determined by the changes of markers basing on their commercial kits. Additionally, annexin A1 (ANXA1) expressions at both protein and mRNA levels were assessed with Western blot and Reverse transcription‑quantitative PCR (RT-qPCR). Moreover, the expressions of apoptosis- and formyl peptide receptor 2 (FPR2) receptors and the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway-related proteins were determined with Western blot., related proteins and proteins. As a result, MP up-regulated the ANXA1 expression in CSE-induced BEAS-2B cells. MP enhanced the viability but suppressed the apoptosis, inflammatory response and oxidative stress of CSE-induced BEAS-2B cells via regulating FPR2/AMPK pathway, while ANXA1 knockdown exhibited oppositive effects on them. In conclusion, MP up-regulated ANXA1 to inhibit the inflammation, apoptosis and oxidative stress of BEAS-2B cells induced by CSE, alleviating COPD through suppressing the FPR2/AMPK pathway.

Comparison of Oxidative Effects of Electronic Cigarette and Tobacco Smoke Exposure Performed Experimentally

OBJECTIVE

Cigarette smoking is a life-threatening habit that has rapidly spread in every socioeconomic part of the public worldwide. There exist mechanisms of nicotine delivery available to use in the hope of halting cigarette smoking, and the electronic cigarette (EC) is one of the common methods used for tobacco smoking replacement. This study aimed to investigate experimentally the oxidative effects of tobacco smoke and EC smoke which contain nicotine.

METHOD

We constructed smoke circuit rooms for exposing the rats to EC or tobacco smoke. Three groups were created, the control group (N = 8); the electronic cigarette group (N = 8), exposure to electronic cigarette smoke for 2 h per day; and the tobacco group (N = 8), exposure to traditional cigarette smoke for 2 h per day. After the first and second week of exposure, blood samples were obtained, and serum oxidative stress index (OSI), paraoxonase 1 (PON1) activity, and prolidase levels were evaluated.

RESULTS

Higher values of OSI and prolidase levels were detected in the first week of EC or tobacco smoke exposure in both study groups (p < 0.001) when compared with the control group, and partial decrements were observed in the second week. By contrast, elevated PON1 levels were observed in the second week after EC or tobacco smoke exposure. The highest OSI levels were observed in the tobacco smoke group (p < 0.001). The lowest values of PON1 levels were detected in the first week of the electronic cigarette smoke group, and this decremental value was statistically different than normal, the second week of the electronic cigarette smoke group, the first week of the traditional cigarette smoke exposure group, and the second week of the traditional cigarette smoke exposure group values (p < 0.000).

CONCLUSION

Our results indicate that EC smoke induced oxidative stress. Therefore, ECs are potentially risky for human health and can lead to important health problems.

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.

The effects of edaravone, a free-radical scavenger in lung injury induced by valproic acid demonstrated via different biochemical parameters

In this study, we aimed to evaluate whether edaravone (EDA) has a protective role against valproic acid (VPA)-induced lung damage via its antioxidative activity. Male Sprague-Dawley rats were split into four groups. Control (n = 8) rats; rats given EDA (30 mg kg^-1  day^-1 ; n = 10); rats given only (VPA, 500 mg kg^-1  day^-1 ; n = 10); rats given VPA + EDA (in the same dose and time) for 7 days. EDA and VPA were applied intraperitoneally. After 8 days, lung tissues were immediately taken from the rats. In lung homogenates, reduced glutathione, total antioxidant status levels, and superoxide dismutase, glutathione peroxidase, sodium/potassium ATPase, paraoxonase1, and carbonic anhydrase activities significantly abated, whereas catalase, glutathione reductase, glutathione-S-transferase activities insignificantly decreased in the VPA-treated group. In contrast, lipid peroxidation, reactive oxygen species, and total oxidant status levels, glycoprotein and protein carbonyl contents, nitric oxide, hydroxyproline levels, and xanthine oxidase, lactate dehydrogenase, arginase, and prolidase activities significantly increased in the VPA-given group. Administration of EDA caused the reverse effects. As a consequence, EDA prevented oxidative stress-mediated lung injury via its robust antioxidant effects.

Plasma prolidase levels are high in schizophrenia but not in first-episode psychosis

An increasing number of studies have focussed on the neurobiology of schizophrenia (SCH), contributing to a better understanding of this disorder. Prolidase is a metalloprotease found in various tissues, which has been associated with the concentrations of proline, a neurotransmitter, in the brain. There is evidence to suggest that elevated proline levels play a role in SCH. The aim of the present study was to compare plasma proline levels in patients with drug-naive first-episode psychosis (FEP) and in those with SCH. Patients diagnosed with FEP (n = 26) and SCH (n = 26) were recruited for this study, in addition to healthy control volunteers (n = 26). Plasma prolidase levels were found to be elevated in the SCH group compared to drug-naive FEP and healthy control groups. This finding indicates that prolidase levels are higher in SCH patients, while levels in patients with drug-naive FEP are similar to those of healthy control. Follow-up studies are needed to provide a better understanding of prolidase in the etiopathogenesis of SCH.

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.

Reliability and Usefulness of Different Biomarkers of Oxidative Stress in Chronic Obstructive Pulmonary Disease

Introduction

Chronic obstructive pulmonary disease (COPD) is a progressive disease characterized by airflow limitation that is not fully reversible after inhaled bronchodilator use associated with an abnormal inflammatory condition. The biggest risk factor for COPD is cigarette smoking. The exposure to noxious chemicals contained within tobacco smoke is known to cause airway epithelial injury through oxidative stress, which in turn has the ability to elicit an inflammatory response. In fact, the disruption of the delicate balance between oxidant and antioxidant defenses leads to an oxidative burden that has long been held responsible to play a pivotal role in the pathogenesis of COPD. There are currently several biomarkers of oxidative stress in COPD that have been evaluated in a variety of biological samples. The aim of this review is to identify the best studied molecules by summarizing the key literature findings, thus shedding some light on the subject.

Methods

We searched for relevant case-control studies examining oxidative stress biomarkers in stable COPD, taking into account the analytical method of detection as an influence factor.

Results

Many oxidative stress biomarkers have been evaluated in several biological matrices, mostly in the blood. Some of them consistently differ between the cases and controls even when allowing different analytical methods of detection.

Conclusions

The present review provides an overview of the oxidative stress biomarkers that have been evaluated in patients with COPD, bringing focus on those molecules whose reliability has been confirmed by the use of different analytical methods.

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.

Comprehensive in-silico prediction of damage associated SNPs in Human Prolidase gene

Prolidase is cytosolic manganese dependent exopeptidase responsible for the catabolism of imido di and tripeptides. Prolidase levels have been associated with a number of diseases such as bipolar disorder, erectile dysfunction and varied cancers. Single nucleotide polymorphism present in coding region of proteins (nsSNPs) has the potential to alter the primary structure as well as function of the protein. Hence, it becomes necessary to differentiate the potential harmful nsSNPs from the neutral ones. 19 nsSNPs were predicted as damaging by in-silico analysis of 298 nsSNPs retrieved from dbSNP database. Consurf analysis showed 18 out of 19 substitutions were present in the conserved regions. 4 substitutions (D276N, D287N, E412K, and G448R) that observed to have damaging effect are present in catalytic pocket. Four SNPs listed in splice site region were found to affect splicing of mRNA by altering acceptor site. On 3′UTR scan of 77 SNPs listed in SNP database, 9 SNPs were lead to alter miRNA target sites. These results provide a filtered data to explore the effect of uncharacterized nsSNP and SNP related to UTRs and splice site of prolidase to find their association with the disease susceptibility and to design the target dependent drugs for therapeutics.

Decreased activity of butyrylcholinesterase in blood plasma of patients with chronic obstructive pulmonary disease

INTRODUCTION

Butyrylcholinesterase (BChE) is involved in the metabolism of endogenous lipids and xenobiotics, such as esters of carboxylic or phosphoric acids. Butyrylcholinesterase activity is associated with both inflammation and oxidative stress. Changes in the activity of this enzyme have been observed in various diseases such as liver cirrhosis, diabetes, neurodegenerative disease and others.

MATERIAL AND METHODS

The study involved 30 patients with chronic obstructive pulmonary disease (COPD) and 18 healthy subjects. The COPD patients were divided according to the severity of the disease by applying the classification of COPD based on GOLD standards for forced expiratory volume in 1 s (FEV₁) and the FEV₁/forced expiratory volume (FVC) ratio. The control group comprised blood samples collected from healthy subjects without concomitant diseases related to the respiratory system. Butyrylcholinesterase activity, lipid peroxidation and total antioxidant capacity (TAC) were determined in the blood plasma.

RESULTS

A significant (p < 0.05) decrease in the activity of BChE, associated with an increase in lipid peroxidation and a decrease in the total antioxidant capacity, was observed in blood plasma of patients with chronic obstructive pulmonary disease.

CONCLUSIONS

The study shows for the first time that activity of BChE in the blood plasma of patients diagnosed with chronic obstructive pulmonary disease is considerably reduced compared with healthy subjects. These changes were accompanied by a decrease of TAC and an increase of lipid peroxidation, which suggests that they may be related to the oxidative stress induced by COPD disease.

The relationships among the levels of oxidative and antioxidative parameters, FEV1 and prolidase activity in COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a progressive condition characterized by poorly reversible airflow limitations associated with an abnormal inflammatory response of the lung.

METHODS

We investigated whether prolidase levels in serum, total antioxidant status, total oxidative status (TOS), and the oxidative stress index (OSI) were associated with the etiopathogenesis of COPD, and whether there is a relationship between prolidase activity and oxidative parameters and carotid artery intima-media thickness (CIMT) in patients with COPD. This study included 91 patients with COPD and 15 control cases. Routine haematological and biochemical parameters were determined in all patients. All subjects were fully informed about the study and provided consent.

RESULTS

The mean age of the patients with COPD was 61.3 ± 10.5 years and that of the control group was 56.2 ± 12.1 years. The control group had a significantly higher plasma prolidase level than that in the COPD group. TOS and OSI levels in the control group were significantly lower than those in the COPD group. However, no significant differences were found in TALs or CIMT levels between the COPD and control groups. A negative correlation was detected between prolidase activity and age; however, no significant difference in age was observed between the two groups.

CONCLUSION

These results indicate that prolidase activity decreases in patients with COPD.

Circulating biomarkers of oxidative stress in chronic obstructive pulmonary disease: a systematic review

Chronic obstructive pulmonary disease (COPD) is a progressive condition characterized by airflow limitation associated with an abnormal inflammatory response of the lungs to noxious particles and gases, caused primarily by cigarette smoking. Increased oxidative burden plays an important role in the pathogenesis of COPD. There is a delicate balance between the toxicity of oxidants and the protective function of the intracellular and extracellular antioxidant defense systems, which is critically important for the maintenance of normal pulmonary functions. Several biomarkers of oxidative stress are available and have been evaluated in COPD. In this review, we summarize the main literature findings about circulating oxidative stress biomarkers, grouped according to their method of detection, measured in COPD subjects.

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.

Serum prolidase enzyme activity and oxidative status in patients with fibromyalgia

OBJECTIVE

This study was performed to investigate serum prolidase enzyme activity and oxidative stress in patients diagnosed with fibromyalgia (FM).

METHODS

The study population consisted of 40 patients with a previous diagnosis of FM and 30 healthy subjects. We measured serum prolidase enzyme activity, total antioxidant status (TAS), total oxidative status (TOS), oxidative stress index (OSI), and paraoxonase-1 (PON-1) levels.

RESULTS

On average, FM patients were diagnosed within 3.2 years of symptom onset, and patients had a mean of 14 tender points. There were no significant differences between patients and controls in age, body mass index, serum TAS, or PON-1 levels. However, patients with FM demonstrated higher serum prolidase activity, TOS, and OSI than the control group. Serum prolidase activity was positively correlated with serum TOS, OSI, and visual analog scale pain and fatigue scores. No correlation was found between serum prolidase activity and FM duration or the average number of tender points.

DISCUSSION

Our results demonstrate a previously unreported association between serum prolidase enzyme activity and FM. Increased prolidase activity may contribute to the pathogenesis of FM, and measuring serum prolidase enzyme activity may be a useful FM biomarker.

Development and systematic oxidative stress of a rat model of chronic bronchitis and emphysema induced by biomass smoke

BACKGROUND

Epidemiological research and meta-analyses of published data have shown that biomass smoke (BS) is a risk factor for chronic obstructive pulmonary disease (COPD). However, the link between BS and COPD lacks experimental confirmation.

OBJECTIVES

To verify whether BS can induce pathologic changes and systemic oxidative stress, which may be relevant to the development of emphysema and chronic bronchitis in rats.

METHODS

Rats were exposed to BS, cigarette smoke (CS), or clean air (sham) for 14 weeks. During the exposure, the O2, SO2, and CO levels were monitored. Pathological changes in the lungs, systemic oxidative stress, and inflammation biomarkers, together with GSTM1 and GSTP1 mRNA expression in the lung were measured. The glutamate-cysteine ligase catalytic subunit (GCLC) protein expression in the lung was measured using immunohistochemistry and western blotting.

RESULTS

The O2, CO, and SO2 levels were 20.31 ± 0.03%, 981.72 ± 64.76, and 2.59 ± 0.26 mg/m(3) for the BS group, respectively, while their levels in the CS group were 20.28 ± 0.15%, 745.56 ± 30.83, and 12.64 ± 0.591 mg/m(3) respectively. As with the rats exposed to CS, the BS rats showed an increased number of inflammatory cells in the bronchoalveolar lavage fluid, an increased pulmonary mean linear intercept and a decreased pulmonary mean alveolar number. Characteristics of chronic bronchitis and peribronchial fibrosis were also found in the BS-exposed rat lungs. Reduced body weight, systemic oxidative stress, and increased GCLC protein expression in the lungs were observed in the rats exposed to BS and CS.

CONCLUSIONS

BS can cause emphysema and chronic bronchitis similar to that caused by CS, which is accompanied by systemic oxidative stress and inflammation.

Prolidase function in proline metabolism and its medical and biotechnological applications

Prolidase is a multifunctional enzyme that possesses the unique ability to degrade imidodipeptides in which a proline or hydroxyproline residue is located at the C-terminal end. Prolidases have been isolated from archaea and bacteria, where they are thought to participate in proline recycling. In mammalian species, prolidases are found in the cytoplasm and function primarily to liberate proline in the final stage of protein catabolism, particularly during the biosynthesis and degradation of collagen. Collagen comprises nearly one-third of the total protein in the body, and it is essential in maintaining tissue structure and integrity. Prolidase deficiency (PD), a rare autosomal recessive disorder in which mutations in the PEPD gene affect prolidase functionality, tends to have serious and sometimes life-threatening clinical symptoms. Recombinant prolidases have many applications and have been investigated not only as a possible treatment for PD, but also as a part of anti-cancer strategies, a component of biodecontamination cocktails and in the dairy industry. This review will serve to discuss the many in vivo functions of procaryotic and eucaryotic prolidases, as well as the most recent advances in therapeutic and biotechnological application of prolidases.