Search

Proanthocyanidins (PCs) have shown inhibition of oxidative damage by improving Nrf-2 expression in many tissues. However, the cytoprotective effects of PCs on H2O2-induced tendon damage have not been verified. The current study was aimed at assessing the cytoprotection of PCs on the oxidative cellular toxicity of tendon-derived stem cells (TDSCs) induced by H2O2. The TDSCs were isolated from patellar tendons of Sprague Dawley (SD) rats, and the cells after third passage were used for subsequent experiments. The isolated cells were identified by flow cytometry assay and multidifferentiation potential assay. Cell Counting Kit-8 assay was performed to examine cell viability. Real-Time PCR and Western Blot were employed to, respectively, assess the mRNA and protein expressions of Nrf-2, GCLM, NQO-1, and HO-1. PCs significantly improved the cell viability of TDSCs. Furthermore, H2O2 upregulated Nrf-2, GCLM, NQO-1, and HO-1 without significant difference, while the proteins expressions were increased with significant difference in PCs group and PCs + H2O2 cotreated group. All the findings indicated that PCs could protect against the oxidative damage induced by H2O2 in TDSCs, and the cytoprotective effects might be due to the ability of PCs to activate the expressions of GCLM, HO-1, and NQO-1 via upregulating Nrf-2 signaling pathway.

Primary frozen shoulder (PFS) is a common condition of uncertain etiology that is characterized by shoulder pain and restriction of active and passive glenohumeral motions. The pathophysiology involves chronic inflammation and fibrosis of the joint capsule. Single nucleotide polymorphisms (SNPs) at IL-1β, MMP3, TGF-β1, and GDF5 have been associated with risk of a variety of inflammatory diseases; however, no studies have examined these SNPs with susceptibility to PFS. We investigated allele and genotype frequencies of rs1143627 at IL-1β, rs650108 at MMP-3, rs1800469 at TGF-β1, and rs143383 at GDF5 in 42 patients with PFS and 50 healthy controls in a Chinese Han population. Serum samples from both cohorts were evaluated to determine the expression levels of IL-1β. We found that the IL-1β rs1143627 CC genotype was associated with a decreased risk of PFS compared to the TT genotype (P=0.022) and that serum IL-1β was expressed at a significantly higher level in the PFS cohort compared to that found in the control group (P<0.001). Our findings indicated no evidence of an association between rs650108, rs1800469, or rs143383 and PFS. IL-1β is associated with susceptibility to PFS and may have a role in its pathogenesis in a Chinese Han population.