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Osteoporosis is a widespread bone metabolic disease characterized by reduced bone mass and bone microstructure deterioration. Ribonucleotide reductase M2 (RRM2) is a key enzyme in DNA synthesis and repair. The present study investigated the effect of RRM2 on osteogenesis of mouse embryo fibroblasts (MEFs) and its molecular mechanism. Bioinformatics analysis revealed that RRM2 expression was increased during osteogenesis of MEFs triggered by bone morphogenetic protein 9. Subsequently, MEFs were used as a mesenchymal stem cell model and osteogenic inducing medium was used to induce osteogenic differentiation. RRM2 protein expression was measured by western blotting during osteogenic differentiation induction of MEFs. RRM2 levels in MEFs were upregulated and downregulated by RRM2-overexpressing recombinant adenovirus and small interfering RNA-RRM2, respectively. Bone formation markers (RUNX family transcription factor 2, osterix, distal-less homeobox 5, collagen type I α1 chain, osteopontin and osteocalcin) were detected by reverse transcription-quantitative (RT-q) PCR and alkaline phosphatase (ALP) and Alizarin Red S staining were examined. The protein expression levels of β-catenin and the ratio of phosphorylated (p-) GSK-3β to GSK-3β were detected by western blotting and the RNA expression of downstream related target genes (β-catenin, axis inhibition protein 2 (AXIN2), transcription factor 7 like 2, lymphoid enhancer binding factor 1, c-MYC and Cyclin D1) in the Wnt/β-catenin signaling pathway was measured by RT-qPCR. RRM2 protein expression increased as the osteogenic differentiation induction period was extended. RRM2 overexpression increased osteogenic marker RNA expression, ALP activity, bone mineralization, the protein expression levels of β-catenin, the ratio of p-GSK-3β to GSK-3β and the RNA expression of downstream related target genes in the Wnt/β-catenin signaling pathway, whereas RRM2 knockdown had the opposite effect. The findings of the present study revealed that RRM2 overexpression enhanced osteogenic differentiation, while RRM2 knockdown reduced osteogenic differentiation. RRM2 may regulate osteogenic differentiation of MEFs via the canonical Wnt/β-catenin signaling pathway, providing a possible therapeutic target for osteoporosis.

<b><i>Background:</i></b> Associations of polymorphisms in interferon-gamma (IFNG), interleukin-10 (IL-10), and interleukin-18 (IL-18) with coronary artery disease (CAD) have already been investigated by many studies, yet the findings of these studies have been somewhat inconsistent. <b><i>Objectives:</i></b> The aim of this meta-analysis was to better clarify associations between polymorphisms in <i>IFNG/IL-10/IL-18</i> and CAD by combing the results of all relevant articles. <b><i>Methods:</i></b> Eligible articles were searched from PubMed, EMBASE, WOS, and CNKI. We used Review Manager to combine the results of indi­vidual studies. <b><i>Results:</i></b> Fifty-one studies were included in this meta-analysis. Combined results revealed that <i>IFNG</i> rs243056, <i>IL-10</i>rs1800871, <i>IL-18</i>rs187238, <i>IL-18</i>rs1946518, and <i>IL-18</i>rs1946519 polymorphisms were all significantly associated with CAD in the general population. We also obtained similar significant results for <i>IFNG</i> rs243056, <i>IL-10</i>rs1800871, <i>IL-10</i> rs1800896, <i>IL-18</i>rs187238, <i>IL-18</i>rs1946518, and <i>IL-18</i>rs1946519 polymorphisms in Asians in further subgroup analyses. <b><i>Conclusions:</i></b> Collectively, this meta-analysis proved that <i>IFNG</i> rs243056, <i>IL-10</i>rs1800871, <i>IL-10</i> rs1800896, <i>IL-18</i>rs187238, <i>IL-18</i>rs1946518, and <i>IL-18</i>rs1946519 polymorphisms may confer susceptibility to CAD for Asians.

Atrial fibrillation (AF)/paroxysmal AF (PAF) is the main cause of cardiogenic embolism. In recent years, the progression from paroxysmal AF to persistent AF has attracted more and more attention. However, the molecular mechanism of the progression of AF is unclear. In this study, we performed RNA sequencing for normal samples, paroxysmal AF and persistent AF samples to identify differentially expressed gene (DEG) and explore the roles of these DEGs in AF. Totally, 272 differently expressed mRNAs (DEmRNAs) and 286 differentially expressed lncRNAs (DElncRNAs) were identified in paroxysmal AF compared to normal samples; 324 DEmRNAs and 258 DElncRNAs were found in persistent atrial fibrillation compared with normal samples; and 520 DEmRNAs and 414 DElncRNAs were identified in persistent AF compared to paroxysmal AF samples. Interestingly, among the DEGs, approximately 50% were coding genes and around 50% were non-coding RNAs, suggesting that lncRNAs may also have a crucial role in the progression of AF. Bioinformatics analysis demonstrated that these DEGs were significantly related to regulating multiple AF associated pathways, such as the regulation of vascular endothelial growth factor production and binding to the CXCR chemokine receptor. Furthermore, weighted gene co-expression network analysis (WGCNA) was conducted to identify key modules and hub RNAs and lncRNAs to determine their potential associations with AF. Five hub modules were identified in the progression of AF, including blue, brown, gray, turquoise and yellow modules. Interestingly, blue module and turquoise module were significantly negatively and positively correlated to the progression of AF respectively, indicating that they may have a more important role in the AF. Moreover, the hub protein-protein interaction (PPI) networks and lncRNA–mRNA regulatory network were constructed. Bioinformatics analysis on the hub PPI network in turquoise was involved in regulating immune response related signaling, such as leukocyte chemotaxis, macrophage activation, and positive regulation of α-β T cell activation. Our findings could clarify the underlying molecular changes associated fibrillation, and provide a useful resource for identifying AF marker.

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