Association of the methionine sulfoxide reductase A rs10903323 gene polymorphism with functional activity and oxidative modification of alpha-1-antitrypsin in COPD patients

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is multi-factorial disorder which results from environmental influences and genetic factors. We aimed to investigate whether methionine sulfoxide reductase A (MSRA) rs10903323 gene polymorphism is associated with COPD development and severity in Serbian adult population.

METHODS

The study included 155 patients with COPD and 134 healthy volunteers. Genotyping was determined performing home-made polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The difference between the inhibitory activities of normal and oxidized Alpha-1-Antitrypsin (A1AT) against elastase and trypsin was used for determination of Oxidized Alpha-1-Antitrypsin (OxyA1AT) (expressed as % and g/L). Functional activity of A1AT was presented as a specific inhibitor activity to elastase (SIA-Elastase, kU/g).

RESULTS

Frequencies of the genotypes AA, AG and GG were 80.0%, 20.0%, 0% in COPD patients and 80.5%, 18.5% and 1.5% in the control group, and there was no significant difference in genotype or allele distributions between groups. Serum level of A1AT (g/L) and OxyA1AT was significantly higher in COPD patients than in the control group, but functional activity of A1AT (SIA-Elastase) was significantly lower in COPD patients than in the control group. In COPD group, increased level of OxyA1AT was present in G allele carriers who were smokers relative to G allele carriers who were not smokers. In the smoker group of patients with severe and very severe COPD (GOLD3+4), significant increase in OxyA1AT level was present in G allele carriers compared to AA homozygotes.

CONCLUSION

These findings suggest that MSRA rs10903323 gene polymorphism is probably not a risk for COPD by itself but could represent a COPD modifier, since minor, G allele, is associated with an increased level of oxidized A1AT, indicating impaired ability of MSRA to repair oxidized A1AT in COPD-smokers, and in severe form of COPD.

Oxidized Alpha-1-Antitrypsin as a Potential Biomarker Associated with Onset and Severity of Chronic Obstructive Pulmonary Disease in Adult Population

Oxidative stress could reduce inhibitor activity of the alpha-1-antitrypsin (A1AT). Oxidative-modified A1AT (oxidized alpha-1-antitrypsin, OxyA1AT) significantly loses ability to protect the lungs from neutrophil elastase. We aimed to investigate OxyA1AT as a potential biomarker associated with onset and severity of chronic obstructive pulmonary disease (COPD) in adult population. The study included 65 patients with COPD (33 smokers and 32 no-smokers) and 46 healthy participants (17 smokers and 29 no-smokers). Determination of OxyA1AT in serum was based on the difference between the inhibitory activities of normal and oxidized A1AT against trypsin and elastase. The level of OxyA1AT was significantly increased in the group of COPD smokers compared to healthy no-smokers (p = 0.030) and COPD no-smokers (p = 0.009). The highest level of OxyA1AT was found in group of smokers with severe and very severe COPD in comparison to the following: no-smokers with the same stage of disease (p = 0.038), smokers with moderate COPD (p = 0.022), and the healthy control group, regardless of the smoking status (control no-smokers p = 0.001 and control smokers p = 0.034). In conclusion, serum level of OxyA1AT would be potentially good biomarker for the assessment of harmful effect of smoking to the onset and severity of COPD. Also, clinical significance of OxyA1AT as prognostic biomarker could be useful in assessing the effectiveness of antioxidant therapy for COPD and emphysema. Suitable and inexpensive laboratory method for determination of OxyA1AT is additional benefit for the introduction of OxyA1AT into routine clinical practice for diagnosis and monitoring of COPD.

Histomorphometric evaluation of implant design as a key factor in peri-implant bone response: a preliminary study in a dog model

AIM

Primary implant stability as the establishment of a direct bone-to-implant contact (BIC) plays a major role in long-term successful implant osseointegration. Numerous factors influencing this initial stability have been studied. This preliminary in vivo study on a dog lower jaw aimed to investigate the hypothesis that primary implant stability in low density bone may be influenced by implant design.

METHODS

The authors compared two different implant designs with regard to their immediate quantitative relation to host bone (BIC% and gap area, GA%). The screw-shaped implants, manufactured by Or-Vit (Castelmaggiore-Bologna, Italy), exhibited similar microroughness surface and two different thread pitches: ''narrow-pitch'' implants (NP) and ''wide-pitch'' implants (WP) with a 0.5 mm and 1.5 mm thread pitch respectively. Implants were placed in dog jaw after complete osseous healing of the extractive sockets, according to a delayed implantation procedure. Five hours after surgery the animal was sacrificed. Radiographic, histological, morphometric and ultrastructural analysis were performed.

RESULTS

An inverse relation existed among the two parameters BIC and GA: GA, as a region with high osteogenetic potentiality, appeared wider in WP implants; BIC, as the expression of primary mechanical stability, was higher in NP implants.

CONCLUSION

Based on this results, we could assume that NP implants might be the clinical choice in case of immediate loading.This single case study might be considered a starting point for further long term in vivo investigations aiming to establish the implant design that best favours osseointegration at different bone quality sites.