Histone methyltransferase SETDB1 promotes osteogenic differentiation in osteoporosis by activating OTX2-mediated BMP-Smad and Wnt/ß-catenin pathways.

Osteogenic differentiation plays important roles in the pathogenesis of osteoporosis. In this study, we explored the regulatory mechanism of histone methyltransferase SET domain bifurcated 1 (SETDB1) underlying the osteogenic differentiation in osteoporosis. The common osteoporosis-related genes were retrieved from the GeneCards, CTD, and Phenolyzer databases. The enrichment analysis was conducted on the candidate osteoporosis-related genes using the PANTHER software, and the binding site between transcription factors and target genes predicted by hTFtarget. The bioinformatics analyses suggested 6 osteoporosis-related chromatin/chromatin binding protein or regulatory proteins (HDAC4, SIRT1, SETDB1, MECP2, CHD7, and DKC1). Normal and osteoporosis tissues were collected from osteoporosis patients to examine the expression of SETDB1. It was found that SETDB1 was poorly expressed in osteoporotic femoral tissues, indicating that SETDB1 might be involved in the development of osteoporosis. We induced SETDB1 overexpression/knockdown, orthodenticle homeobox 2 (OTX2) overexpression, activation of Wnt/ß-catenin or BMP-Smad pathways alone or in combination in osteoblasts or ovariectomized mice. The data indicated that SETDB1 methylation regulated H3K9me3 in the OTX2 promoter region and inhibited the expression of OTX2. Besides, the BMP-Smad and Wnt/ß-catenin pathways were inhibited by OTX2, thereby resulting in inhibited osteogenic differentiation. Animal experiments showed that overexpressed SETDB1 could promote the increase of calcium level and differentiation of femoral tissues. In conclusion, upregulation of SETDB1 promotes osteogenic differentiation by inhibiting OTX2 and activating the BMP-Smad and Wnt/ß-catenin pathways in osteoporosis.

Comparison of the supraglottic airway device BlockBusterTM and laryngeal mask airway Supreme in anaesthetised, paralyzed adult patients: a multicenter randomized controlled trial.

BACKGROUND: This multicenter prospective, randomized controlled clinical trial compared the clinical performance of supraglottic airway device (SAD) BlockBusterTM and laryngeal mask airway (LMA) Supreme for airway maintenance in anesthetized, paralyzed adult patients. METHODS: A total of 651 adult patients scheduled for elective surgery in 13 hospitals were randomly allocated into BlockBuster group (n = 351) or Supreme group (n = 300). The primary outcome was oropharyngeal leak pressure (OLP). Duration and ease of insertion, fiberscopic view of positioning, airway manipulations, and complications were also assessed. RESULTS: The OLP was significantly higher in BlockBuster group compared with Supreme group (29.9 ± 4.2 cmH2O vs 27.4 ± 4.3 cmH2O, p < 0.001). Success rate of insertion at the first attempt (90.2% vs 85.1%, p = 0.027), rate of optimal fiberscopic view (p = 0.002) and satisfactory positioning of SAD (p < 0.001) were significantly increased in BlockBuster group. CONCLUSIONS: Both SAD BlockBusterTM and LMA Supreme are safe, effective, and easy-to-use devices for airway maintenance in anesthetized, paralyzed adult patients, but the SAD BlockBusterTM is superior to LMA Supreme in terms of OLP, success rate at the first attempt, and fiber-optic view of positioning. TRIAL REGISTRATION: The trial is registered at www.chictr.org.cn (ChiCTR-ONC-16009105).