Relation of serum elastin peptide concentration to age, FEV1, smoking habits, alcohol consumption, and protease inhibitor phenotype: an epidemiological study in working men

Tumour cell blebbing and extracellular vesicle shedding: key role of matrikines and ribosomal protein SA

BACKGROUND

Carcinogenesis occurs in elastin-rich tissues and leads to local inflammation and elastolytic proteinase release. This contributes to bioactive matrix fragment (Matrikine) accumulation like elastin degradation products (EDP) stimulating tumour cell invasive and metastatic properties. We previously demonstrate that EDPs exert protumoural activities through Hsp90 secretion to stabilised extracellular proteinases.

METHODS

EDP influence on cancer cell blebbing and extracellular vesicle shedding were examined with a videomicroscope coupled with confocal Yokogawa spinning disk, by transmission electron microscopy, scanning electron microscopy and confocal microscopy. The ribosomal protein SA (RPSA) elastin receptor was identified after affinity chromatography by western blotting and cell immunolocalisation. mRNA expression was studied using real-time PCR. SiRNA were used to confirm the essential role of RPSA.

RESULTS

We demonstrate that extracellular matrix degradation products like EDPs induce tumour amoeboid phenotype with cell membrane blebbing and shedding of extracellular vesicle containing Hsp90 and proteinases in the extracellular space. EDPs influence intracellular calcium influx and cytoskeleton reorganisation. Among matrikines, VGVAPG and AGVPGLGVG peptides reproduced EDP effects through RPSA binding.

CONCLUSIONS

Our data suggests that matrikines induce cancer cell blebbing and extracellular vesicle release through RPSA binding, favouring dissemination, cell-to-cell communication and growth of cancer cells in metastatic sites.

Abnormal levels of age-elastin derived peptides in sera of diabetic patients with arterial hypertension

Introduction

An important factor in vascular wall alterations is degradation of elastic fiber major protein – elastin. As a result, elastin derived peptides (EDP) are found in circulation. Advanced glycation might also involve elastin, because it is a protein with slow metabolism. The aim of our study was to measure serum levels of glycated elastin derived peptides (AGE-EDP) of elastin in patients with type 2 diabetes mellitus (T2DM) and arterial hypertension (AH).

Material and methods

We adapted an ELISA technique for the determination of AGE-EDP. Sera of 93 patients with T2DM and AH (mean age 61.4 ±11.3 years, diabetes duration 9.88 ±3.12 years; hypertension duration 9.28 ±4.98) were tested. These values were compared to 42 age- and sex-matched controls. Diabetics were divided in two groups according to presence – Group 1 (n = 67) or absence – Group 2 (n = 26) of microangiopathy.

Results

Patients with T2DM and AH showed statistically significantly higher levels of AGEEDP in comparison with healthy controls 0.060 (0.053÷0.065) vs. 0.039 (0.031÷0.044) (KW = 35.2; p < 0.0001). Group 1 showed significantly higher levels of AGE-EDP than the control group 0.069 (0.051÷0.070) vs. 0.039 (0.031÷0.044) (KW = 33.0; p < 0.0001). Group 2 also showed significantly higher levels of AGE-EDP than controls 0.058 (0.049÷0.064) vs. 0.039 (0.031÷0.044) (KW = 22.1; p < 0.0001). AGE-EDP showed a correlation with an insulin dose (r = –0.28; p = 0.05), systolic blood pressure (r = 0.25; p = 0.01), BMI (r = 0.39; p = 0.01) and retinopathy (r = 0.18; p = 0.05).

Conclusions

The measurement of non-invasive markers of elastin glycation may be useful in monitoring development of vascular wall alterations and therapeutic interventions.

Decreased circulating elastin peptide levels in humans with sepsis

OBJECTIVE

Sepsis is a potentially life-threatening medical condition induced by viral, bacterial or fungal infection, which is characterized by systemic inflammation, hypotension and vasodilation that can lead to cardiovascular collapse. Increased activity of elastases, enzymes which degrade the extracellular matrix components including elastin, has been demonstrated in plasma of septic patients. Since elastin peptides (EP), by binding to an elastin-laminin receptor on vascular endothelial and smooth muscle cells, induce dose-dependent vasodilation, we hypothesized that elevated circulating EP could contribute to the vasodilation that occurs in septic patients.

MATERIALS AND METHODS

Blood for measurement of EP was collected from not-septic and septic patients admitted to the intensive care unit (ICU), as well as from healthy subjects. Plasma EP concentrations were measured using a competitive ELISA technique.

RESULTS

The plasma EP level in the septic patients was approximately half that of the not-septic patients and the healthy controls, with similar EP levels in the latter two groups. There was no apparent association between EP levels and age or gender in any of the groups.

CONCLUSIONS

Plasma EP levels were actually decreased in septic patients, possibly indicating that the balance between EP production vs. elimination favors elimination. This result further suggests that circulating EP may not be important in the development of the vasodilation and hypotension that occurs in septic shock. Alternatively, however, increased degradation of EP by elastase or other enzymes could lead to the appearance of biologically active EP, which may not be recognized by the ELISA assay.

An association of anti-elastin IgA antibodies with development of retinopathy in diabetic children

An important factor in the development of vascular wall alterations is degradation of the elastic fiber major protein-elastin. Elastin peptides derived from this degradation are present in the circulating blood and they are a stimulus for increased production of anti-elastin antibodies (AEAb). The aim of the present study was to examine the possible association between serum elastin AEAb and the development of diabetic vascular complications. Levels of AEAb (IgG, IgM and IgA) were determined by ELISA in sera of 28 children with Type 1 (insulin-dependent) diabetes mellitus (mean age 11.6+/-2.8 years, diabetes duration 5.1+/-2.5 years). None of the children had clinical or laboratory evidence of vascular complications. The children were followed over a period of 7 years, and 24 healthy children of similar age and sex served as a control group. During the study, four diabetics developed retinopathy, six microalbuminuria and two both retinopathy and microalbuminuria. Anti-elastin IgG showed correlation with diabetes duration (r=.48, P=.0007), HbA1c (r=.28, P=.05), triglycerides (r=.28, P=.05) and antibodies to advanced glycation endproducts (AGE) (r=.41, P=.005). Anti-elastin IgM correlated with HbA1c (r=.26, P=.038) and IgA with retinopathy (r=.32, P=.017). Our results suggest an association between the level of anti-elastin IgA antibodies and the development of diabetic retinopathy.

Alcohol, smoking and lung disease

Alcohol and smoking are two well-known health hazards. Alcohol and tobacco consumption are strongly correlated and heavy drinkers have more trouble quitting smoking than do light drinkers. Death from tobacco-related causes was more common than alcohol-related death in a follow-up study on patients admitted to an addiction programme for treatment of alcoholism and non-nicotine drug dependence. In British male doctors in the middle and elderly age group, a protective effect of light and moderate alcohol consumption (1-3 British units of alcohol per day) compared with abstinence has been shown in one large survey. This protective effect was shown in overall mortality as well as in mortality from respiratory disease. Higher alcohol intakes were associated with an increase in mortality. This characteristic U-formed, or J-formed, dose-response curve has been found in most studies with an apparent beneficial effect of modest alcohol intake and a harmful effect of high intakes. The anti-inflammatory effect of alcohol has been considered to be responsible for its limited protective effect on smoking-related lung function decline. Recently, a hitherto unconfirmed report suggests that the beneficial effect of alcohol on lung function in men is restricted to subjects with Lewis-negative blood group (10% of the Caucasian population). On the other hand, the protective effect in those individuals is large enough to be clinically relevant. Prospective investigations including both men and women are needed to elucidate which individuals have a protective effect of light and moderate alcohol intake. The major deleterious effect of smoking, including passive smoking, must be kept in mind-drinking alcohol surrounded by cigarette smoke might not be beneficial for respiratory health.

Relationship of serum elastin peptide level to single breath transfer factor for carbon monoxide in French coal miners

BACKGROUND

Clinical and epidemiological studies have given discordant results on the usefulness of the level of circulating elastin peptide (EP), a potential marker of both elastin destruction (a key phenomenon in pulmonary emphysema) and neosynthesis, for assessing structural changes in the lung extracellular matrix. The aim of the present study was to explore the relationship between levels of EP and forced expiratory volume in one second (FEV1) and single breath transfer factor for carbon monoxide (TLCO and KCO) in coal miners.

METHODS

The study population comprised 227 working coal miners aged 34-50 years consisting of 75 miners heavily exposed to underground coal dust with pulmonary radiographs classified as 0/1 or 1/0 by the International Labour Office classification, 75 exposed miners with radiographs classified as normal (0/0), and 77 miners slightly exposed to coal dust with normal radiographs. The subjects answered a standardised questionnaire and performed spirometric tests and a carbon monoxide (CO) transfer test.

RESULTS

No association was observed between EP levels and % predicted FEV1 (or FEV1/FVC). The level of EP increased significantly with decreased % predicted TLCO (r = -0.20). Miners in the lowest % predicted KCO quintile had higher EP levels than the rest (3.28 (1.37) vs 2.47 (1.16)). A significantly lower EP level was observed in miners with radiographs classified as 1/0 or 0/1, especially in those with round opacities, compared with miners with a normal radiograph, and in current smokers compared with the rest.

CONCLUSIONS

The results of this study suggest that the level of EP may reflect some remodelling activity in emphysema and lung fibrosis.