Association of PAR-2 Gene Polymorphisms with the Inflammatory Response and Susceptibility to Knee Osteoarthritis in the Chinese Han Population

Association of single nucleotide polymorphisms in the F2RL1 gene with clinical and inflammatory characteristics of patients with asthma

BACKGROUND

Proteinase-activated receptor 2 (PAR-2) is a G-protein coupled receptor associated with many inflammatory diseases, including asthma. We have shown an association between PAR-2 expression in peripheral blood monocytes and asthma severity as well as blood PAR-2 mRNA level and lung function. Since F2RL1 (the gene encoding PAR-2) polymorphisms affect PAR-2 expression, we hypothesize they may affect asthma severity.

METHODS

We recruited 76 subjects with asthma of varying severity and collected clinical (FEV1 [% predicted], FEV1/FVC, IgE) and immunological (PAR-2 mRNA, blood eosinophils) disease parameters. We also genotyped these individuals for 3 F2RL1 SNPs (-45C/T, -149C/G, c.621C/T).

RESULTS

We found that the F2RL1 SNP "C" allele of -45C/T (rs1529505) was associated with PAR-2 mRNA and blood eosinophils. F2RL1 SNP c.621C/T (rs631465) was associated with PAR-2 mRNA. The F2RL1 SNP -149C/G (rs2242991) had no association with any of the parameters studied. This study identified one F2RL1 SNP rs1529505 is associated with parameters of asthma, but not asthma severity.

CONCLUSION

Larger studies are needed to further elucidate the role of PAR-2 in the pathophysiology of asthma and the influence of genetic variation.

Protease-activated receptor-2: Role in asthma pathogenesis and utility as a biomarker of disease severity

PAR₂, a receptor activated by serine proteases, has primarily pro-inflammatory roles in the airways and may play a role in asthma pathogenesis. PAR₂ exerts its effects in the lungs through activation of a variety of airway cells, but also activation of circulating immune cells. There is evidence that PAR₂ expression increases in asthma and other inflammatory diseases, although the regulation of PAR₂ expression is not fully understood. Here we review the available literature on the potential role of PAR₂ in asthma pathogenesis and propose a model of PAR₂-mediated development of allergic sensitization. We also propose, based on our previous work, that PAR₂ expression on peripheral blood monocyte subsets has the potential to serve as a biomarker of asthma severity and/or control.

Enhancement of the functionality of women with knee osteoarthritis by a gel formulation with Caryocar coriaceum Wittm ("Pequi") nanoencapsulated pulp fixed oil

Osteoarthritis (OA) is a degenerative joint disease that occurs when there is a change in the mechanical and biological properties of the articular cartilage and the subchondral bone; The condition is more prevalent in women than in men. Pequi oil (PO), which is extracted from the fruits of the pequi tree (Caryocar coriaceum Wittm), is widely used in traditional medicine in the Brazilian northeast for the management of inflammation and joint pain. The aim of this study was to develop a pharmaceutical formulation containing Carbopol® hydrogel nanoencapsulated with pequi pulp fixed oil (PeONC) and evaluate its therapeutic effect on functionality and pain in women with knee osteoarthritis. The study was divided into two stages: Stage 1 - preparation and physico-chemical characterization of the pharmaceutical formulation containing PeONC, cell viability assays and skin irritability testing. Step 2 - A double-blind randomized clinical trial evaluating knee symptoms, quality of life, pressure pain, function, muscle strength and range of motion. The nanoformulation was in a gel form, with a particle size of 209.5 ± 1.06 nm, a pH of 6.23 ± 0.45, a zeta potential of - 23.1 ± 0.4 mV, a polydispersity index of 0.137 ± 0.52, and containing nanocapsules with a spherical shape a polymeric wall and an oily nucleus. The gel showed no cytotoxicity and was not irritating to human skin. The treatment with PeONC increased the strength of the knee flexor and extensor muscles and the total motion range of the knee. In addition, the treatment reduced knee instability, pain, swelling, and locking; There was also an improvement in some items of the SF-36 quality of life questionnaire such as in respect of functional capacity and social aspects. In conclusion, PeONC was found to be a stable, safe formulation with no toxicity in respect of topical use in humans. Additionally, the treatment produced an increase in muscle strength and functionality that was associated with reduced knee symptoms and improved quality of life. Our findings showed that in a group of women treated with PeONC mitigated the symptoms of knee osteoarthritis.

Association between the MMP-1-1607 1G/2G Polymorphism and Osteoarthritis Risk: A Systematic Review and Meta-Analysis

Background

Osteoarthritis (OA) is a common disease characterized by articular cartilage degeneration and secondary hyperosteogenesis. Genetic factors are associated with the occurrence of OA. While several studies have shown that the matrix metalloproteinase-1- (MMP-1-) 1607 1G/2G (rs1799750) polymorphism may be related to the occurrence and development of OA, there is inconsistency in the literature. To better estimate the relationship between the MMP-1 gene polymorphism and OA, a comprehensive meta-analysis of relevant literature was carried out.

Results

In total, seven studies comprising 1245 OA patients and 1230 controls were included in this meta-analysis. The combined results revealed no significant association between the MMP-1-1607 1G/2G polymorphism and risk of OA in the five genetic models. However, after Bonferroni correction, the results of subgroup analysis revealed a significant correlation between the MMP-1-1607 1G/2G polymorphism and OA susceptibility in the temporomandibular joint (TMJ) OA subgroup (allelic: 2G vs. 1G: OR = 1.575, 95%CI = 1.259–1.972, P < 0.01; recessive: 2G2G vs. 1G1G+1G2G: OR = 2.411, 95%CI = 1.658–3.504, P < 0.01; and homozygote: 2G2G vs. 1G1G: OR = 2.313, 95%CI = 1.341, 3.991, P = 0.003), the younger subgroup (aged less than 60 years; allelic: 2G vs. 1G: OR = 1.635, 95%CI = 1.354, 1.974, P < 0.01; dominant: 2G1G+2G2G vs. 1G1G: OR = 1.622, 95%CI = 1.158, 2.271, P = 0.005; recessive: 2G2G vs. 1G1G+1G2G: OR = 2.209, 95%CI = 1.718, 2.840, P < 0.01; and homozygote: 2G2G vs. 1G1G: OR = 2.578, 95%CI = 1.798, 3.696, P < 0.01), the larger subgroup (N > 300), and the hospital-based case-control study (HCC) subgroup. The sensitivity analysis suggested that the results of the meta-analysis were stable and reliable. Begg's funnel plot and Egger's test indicated that there was no publication bias in this study.

Conclusion

Our meta-analysis indicated that although the MMP-1-1607 1G/2G polymorphism was not significantly associated with OA susceptibility among the whole sample, it played a key role in the etiology and development of TMJ OA and OA in people aged less than 60 years.