DNA methylation in osteoarthritic chondrocytes: a new molecular target

OBJECTIVE: To review the current knowledge of the mechanism of DNA methylation, its association with transcriptional silencing, possible mechanisms of hyper- and hypomethylation and how epigenetic changes may relate to the pathogenesis of osteoarthritis (OA). METHODS: Journal literature was searched using Pubmed. Since there are very few publications directly on epigenetic phenomena in OA, the search was extended to give an overview of epigenetic mechanisms as they relate to the molecular mechanisms of the disease. RESULTS: While the epigenetics of cancer cells have been intensively investigated, little attention has so far been paid as to whether epigenetic changes contribute to the pathology of non-neoplastic diseases such as OA. This review explains the mechanisms of DNA methylation, its role in transcriptional regulation, and possible demethylation mechanisms that may be applicable to OA. Preliminary evidence suggests that changes in DNA methylation, together with cytokines, growth factors and changes in matrix composition, are likely to be important in determining the complex gene expression patterns that are observed in osteoarthritic chondrocytes. CONCLUSION: Early evidence points to a role of epigenetics in the pathogenesis of OA. Since epigenetic changes, although heritable at the cellular level, are potentially reversible, epigenetics could be a new molecular target for therapeutic intervention, especially early in the disease

Efficacy and safety of tregalizumab in patients with rheumatoid arthritis and an inadequate response to methotrexate: results of a phase IIb, randomised, placebo-controlled trial

To evaluate the efficacy, biological activity and safety of tregalizumab in patients with active rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX). 321 patients were randomised (1:1:1:1) to placebo or tregalizumab 25, 100 or 200 mg once-weekly subcutaneously in addition to MTX treatment. Responders at week 12 continued the same treatment, and non-responders at week 12 were escalated to the next higher tregalizumab dose level or re-randomised from placebo to active treatment. After 24 weeks, patients could continue treatment with tregalizumab for 24 weeks (extension phase). The primary endpoint was the American College of Rheumatology 20% improvement criteria (ACR20) response rate at week 12. Safety and biological activity were monitored through week 48. At week 12, ACR20 response rates were not statistically significantly different between placebo and any of the tregalizumab doses. Tregalizumab injections were well tolerated; most adverse events were mild to moderate and comparable among treatment and placebo groups. Biological activity was shown by dose-dependent CD4 downmodulation. Treatment with tregalizumab did not show significant clinical efficacy in patients with active RA compared with placebo but resulted in the expected biological effect on CD4 modulation. Tregalizumab was generally well tolerated, and no new safety findings were identified. NCT01999192; Result

Heterozygous carriage of the alpha1-antitrypsin Pi*Z variant increases the risk to develop liver cirrhosis

Objective Homozygous alpha1-antitrypsin (AAT) deficiency increases the risk for developing cirrhosis, whereas the relevance of heterozygous carriage remains unclear. Hence, we evaluated the impact of the two most relevant AAT variants (' Pi* Z' and ' Pi* S'), present in up to 10% of Caucasians, on subjects with non-alcoholic fatty liver disease (NAFLD) or alcohol misuse. Design We analysed multicentric case-control cohorts consisting of 1184 people with biopsy-proven NAFLD and of 2462 people with chronic alcohol misuse, both cohorts comprising cases with cirrhosis and controls without cirrhosis. Genotyping for the Pi* Z and Pi* S variants was performed. Results T he Pi* Z variant presented in 13.8% of patients with cirrhotic NAFLD but only in 2.4% of counterparts without liver fibrosis (p< 0.0001). Accordingly, the Pi* Z variant increased the risk of NAFLD subjects to develop cirrhosis (adjusted OR=7.3 (95% CI 2.2 to 24.8)). Likewise, the Pi* Z variant presented in 6.2% of alcohol misusers with cirrhosis but only in 2.2% of alcohol misusers without significant liver injury (p< 0.0001). Correspondingly, alcohol misusers carrying the Pi* Z variant were prone to develop cirrhosis (adjusted OR=5.8 (95% CI 2.9 to 11.7)). In contrast, the Pi* S variant was not associated with NAFLDrelated cirrhosis and only borderline with alcohol-related cirrhosis (adjusted OR=1.47 (95% CI 0.99 to 2.19)). Conclusion T he Pi* Z variant is the hitherto strongest single nucleotide polymorphism-based risk factor for cirrhosis in NAFLD and alcohol misuse, whereas the Pi* S variant confers only a weak risk in alcohol misusers. As 2%-4% of Caucasians are Pi* Z carriers, this finding should be considered in genetic counselling of affected individuals