Long noncoding RNAs (lncRNAs) are emerging as important regulatory molecules at the transcriptional and post-transcriptional levels and may play essential roles in the differentiation of human bone marrow mesenchymal stem cell (hMSC). However, their roles and functions remain unclear. Here, we showed that lncRNA H19 was significantly upregulated after the induction of osteoblast differentiation. Overexpression of H19 promoted osteogenic differentiation of hMSCs in vitro and enhanced heterotopic bone formation in vivo, whereas knockdown of H19 inhibited these effects. Subsequently, we found that miR-675, encoded by exon1 of H19, promoted osteoblast differentiation of hMSCs and was partially responsible for the pro-osteogenic effect of H19. Investigating the underlying mechanism, we demonstrated that H19/miR-675 inhibited mRNA and protein expression of transforming growth factor-b1 (TGF-b1). The downregulation of TGF-b1 subsequently inhibited phosphorylation of Smad3. Meanwhile, H19/miR-675 downregulated the mRNA and protein levels of histone deacetylase (HDAC) 4/5, and thus increased osteoblast marker gene expression. Taken together, our results demonstrated that the novel pathway H19/miR-675/TGF-b1/Smad3/HDAC regulates osteogenic differentiation of hMSCs and may serve as a potential target for enhancing bone formation in vivo. STEM CELLS 2015;33:3481-3492 SIGNIFICANCE STATEMENTLong noncoding RNAs (lncRNAs) are emerging as important regulatory molecules in biology control and pathology. However, their roles and functions in osteogenic differentiation of mesenchymal stem cell (MSC) remain unclear. Our studies provide important insights into the prodifferentiation effect of lncRNA H19 in osteogenesis both in vitro and in vivo. miR-675 is partially responsible for this pro-osteogenic effect of H19 via the transforming growth factor-b1 (TGF-b1)/Smad3/histone deacetylase (HDAC) pathway. These findings provide important clues for understanding the role of lncRNA-miRNA-mRNA functional network in osteogenic differentiation, and would be helpful in developing stem cell-based therapy for bone defect.

Background: In March 2020, the World Health Organization declared coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a pandemic. Currently, data on changes in sexual behavior during the COVID-19 outbreak are limited. Aim: The present study aimed to obtain a preliminary understanding of the changes in people's sexual behavior, as a result of the pandemic, and explore the context in which they manifest. Methods: A convenience sample of 270 men and 189 women who completed an online survey consisting of 12 items plus an additional question were included in the study. Outcomes: The study outcomes were obtained using a study-specific questionnaire to assess the changes in people's sexual behavior. Results: While there was a wide range of individual responses, our results showed that 44% of participants reported a decrease in the number of sexual partners and about 37% of participants reported a decrease in sexual frequency. Multiple regression analysis showed that age, partner relationship, and sexual desire were closely related to sexual frequency. In addition, we found that most individuals with risky sexual experiences had a rapid reduction in risky sexual behavior. Clinical Implications: The current findings contribute to identifying another potential health implication associated with the COVID-19 pandemic and report preliminary evidence of the need to provide potential interventions for the population. Strength & Limitations: This study is the first to perform a preliminary exploration of sexual behavior during the COVID-19 outbreak. The generalizability of the results is limited, given that only a small convenience sample was used. Conclusion: During the height of the COVID-19 outbreak, overall sexual activity, frequency, and risky behaviors declined significantly among young men and women in China.

BackgroundPeriodontal ligament stem cells (PDLSCs) are considered as candidate cells for the regeneration of periodontal and alveolar bone tissues. Antisense to the cerebellar degeneration-related protein 1 transcript (CDR1as), which is a newly discovered circular RNA (circRNA), has been reported to act as an miR-7 sponge and to be involved in many biological processes. Here, we investigated the potential roles of CDR1as and miR-7 in the osteogenic differentiation of PDLSCs.MethodsThe expression pattern of CDR1as and miR-7 in PDLSCs during osteogenesis was detected by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Then we overexpressed or knocked down CDR1as or miR-7 to confirm whether they were involved in the regulation of osteoblast differentiation in PDLSCs. Alkaline phosphatase (ALP) and alizarin red S (ARS) staining were used to detect the activity of osteoblasts and mineral deposition. Furthermore, a dual luciferase reporter assay was conducted to analyze the binding of miR-7 to growth differentiation factor (GDF)5. To further verify the role of CDR1as in osteoblast differentiation, we conducted animal experiments in vivo. New bone formation in specimens was analyzed by microcomputed tomography (micro-CT), hematoxylin and eosin staining, and immunofluorescence staining.ResultsWe observed that CDR1as was significantly upregulated during the osteogenic differentiation, whereas miR-7 was significantly downregulated. Moreover, knockdown of CDR1as and overexpression of miR-7 inhibited the ALP activity, ARS staining, and expression of osteogenic genes. Overexpression of miR-7 significantly reduced the activity of luciferase reporter vectors containing the wild-type, but not the mutant, 3’ untranslated region (UTR) sequence of GDF5. Furthermore, knockdown of GDF5 partially reversed the effects of miR-7 inhibitor on osteoblast differentiation. Downregulation of CDR1as or GDF5 subsequently inhibited phosphorylation of Smad1/5/8 and p38 mitogen-activated protein kinases (MAPK), while upregulation of miR-7 decreased the level of phosphorylated Smad1/5/8 and p38 MAPK. In vivo, CDR1as knockdown lead to less bone formation compared with the control group as revealed by micro-CT and the histological analysis.ConclusionsOur results demonstrated that CDR1as acts as a miR-7 inhibitor, triggering the upregulation of GDF5 and subsequent Smad1/5/8 and p38 MAPK phosphorylation to promote osteogenic differentiation of PDLSCs. This study provides a novel understanding of the mechanisms of osteogenic differentiation, and suggests a potential method for promoting bone formation.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0976-0) contains supplementary material, which is available to authorized users.

Bone marrow mesenchymal stem cells (BMSCs) exhibit an increased propensity toward adipocyte differentiation accompanied by a reduction in osteogenesis in osteoporotic bone marrow. However, limited knowledge is available concerning the role of long non-coding RNAs (lncRNAs) in the differentiation of BMSCs into adipocytes. In this study, we demonstrated that lncRNA H19 and microRNA-675 (miR-675) derived from H19 were significantly downregulated in BMSCs that were differentiating into adipocytes. Overexpression of H19 and miR-675 inhibited adipogenesis, while knockdown of their endogenous expression accelerated adipogenic differentiation. Mechanistically, we found that miR-675 targeted the 3′ untranslated regions of the histone deacetylase (HDAC) 4–6 transcripts and resulted in deregulation of HDACs 4–6, essential molecules in adipogenesis. In turn, trichostatin A, an HDAC inhibitor, significantly reduced CCCTC-binding factor (CTCF) occupancy in the imprinting control region upstream of the H19 gene locus and subsequently downregulated the expression of H19. These results show that the CTCF/H19/miR-675/HDAC regulatory pathway plays an important role in the commitment of BMSCs into adipocytes.

Among the various sources of human autologous stem cells, stem cells isolated from dental tissues exhibit excellent properties in tissue engineering and regenerative medicine. However, the distinct potential of these odontogenic cell lines remains unclear. In this study, we analyzed DNA methylation patterns to determine whether specific differences existed among three different odontogenic cell types. Using the HumanMethylation450 Beadchip, the whole genomes of human dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), and dental follicle progenitor cells (DFPCs) were compared. Then, the osteogenic potential of these cells was evaluated both in vitro and in vivo, and the methylation levels of certain genes related to bone formation differed among the three cell lines. P values less than 0.05 were considered to indicate statistical significance. The three cell types showed highly similar DNA methylation patterns, although specific differences were identified. Gene ontology analysis revealed that one of the most significantly different gene categories was related to bone formation. Thus, expression of cell surface epitopes and osteogenic-related transcription factors as well as the bone formation capacity were compared. The results showed that compared with DFPCs and DPSCs, PDLSCs had higher transcription levels of osteogenic-related factors, a higher in vitro osteogenic potential, and an increased new bone formation capacity in vivo. In conclusion, the results of this study suggested that the differential DNA methylation profiles could be related to the osteogenic potential of these human odontogenic cell populations. Additionally, the increased osteogenic potential of PDLSCs might aid researchers or clinicians in making better choices regarding tissue regeneration and clinical therapies.

Genome-wide association studies (GWASs) have reproducibly associated ∼40 susceptibility loci with psoriasis. However, the missing heritability is evident and the contributions of coding variants have not yet been systematically evaluated. Here, we present a large-scale whole-exome array analysis for psoriasis consisting of 42,760 individuals. We discover 16 SNPs within 15 new genes/loci associated with psoriasis, including C1orf141, ZNF683, TMC6, AIM2, IL1RL1, CASR, SON, ZFYVE16, MTHFR, CCDC129, ZNF143, AP5B1, SYNE2, IFNGR2 and 3q26.2-q27 (P<5.00 × 10−08). In addition, we also replicate four known susceptibility loci TNIP1, NFKBIA, IL12B and LCE3D–LCE3E. These susceptibility variants identified in the current study collectively account for 1.9% of the psoriasis heritability. The variant within AIM2 is predicted to impact protein structure. Our findings increase the number of genetic risk factors for psoriasis and highlight new and plausible biological pathways in psoriasis.

Expression profiles of circRNAs were significantly altered during osteogenic differentiation of PDLSCs, providing a clue for future studies on the role of circRNAs in osteoblast differentiation.

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