ABSTRACT
BACKGROUND:There is lack of effective diagnostic methods for early knee osteoarthritis. Proteomics refers to the large-scale experimental analysis of proteomes from the overal level of intracel ular protein compositioon, expression and modification, based on which, we can understand protein-protein interaction and relationship, thereby revealing protein functions and cel activity patterns. OBJECTIVE:To apply the isobaric tags for relative and absolute quantitation (iTRAQ) to identify proteins differential y in serums of osteoarthritis Kel gren-Lawrence classification at each stage, and to find out potential molecular markers at each stage of osteoarthritis. METHODS:Sixty patients with knee osteoarthritis were enrol ed, and according to Kel gren-Lawrence (K-L) grading, they were subdivided into K-L 0, II and IV groups. There were 10 males and 10 females randomly selected in each group. Proteins differential y regulated in serums were identified by the stable isotopes 116, 117, 118 of the iTRAQ labeled, reversed-phase column separation, mass spectrometry and Swissport database search, after the serums were subjected to high abundance proteins depletion. Final y, we analyzed the proteins identified by using bioinformatics software. RESULTS AND CONCLUSION:Total y 169 proteins were identified through iTRAQ peptides experiments of different sample tags, Q-star mass spectrum identification and MASCOT library search. 153 proteins were identified as K-L 0 to K-L IV, 153 proteins were identified as K-L 0 to K-L II, and 145 proteins were identified as K-L II to K-L IV. iTRAQ technology may help to identify novel serum markers for early diagnosis of knee osteoarthritis, indicating iTRAQ technology for proteomics serum biomarkers of osteoarthritis study has good application prospect.
ABSTRACT
BACKGROUND:The pathogenesis of knee osteoarthritis is stil not very clear, and there is a lack of early diagnosis methods. Because it is more common in middle-aged women, it is suggested that the pathogenesis of knee osteoarthritis may be closely related to serum estradiol levels in the human body. OBJECTIVE:To explore the correlation between the level of serum estradiol and the severity of osteoarthritis in female patients with knee osteoarthritis. METHODS:Seventy-six female patients with knee osteoarthritis admitted in the First Affiliated Hospital of Guangxi Medical University from February 2012 to December 2013 were enroled, and divided into premenopause group (n=42) and postmenopause group (n=34). According to Kelgren-Lawrence (K-L) grading, both two groups were subdivided into K-L 0, II and IV groups. The knee function was evaluated with Hospital for Special Surgery (HSS) Knee Score Standard in USA, the serum estradiol levels were detected with electrochemiluminescence immunoassay. Then, the correlation analysis was performed. RESULTS AND CONCLUSION: The serum estradiol levels of the premenopause group and postmenopause group were decreased significantly with the increase of K-L grade and age (P < 0.05). Under the same K-L grade, the serum estradiol levels in the postmenopausal patients were significantly lower than those in the premenopausal patients. Linear regression analysis showed that there was a negative relationship between age and serum estradiol level (R2=0.222,P < 0.05), and there was a positive correlation between HSS scores and serum estradiol levels (R2=0.415,P < 0.05). The severity of knee osteoarthritis in female patients shows a negative correlation with the level of serum estradiol but a positive correlation with age.