摘要: Objectives N6-methyladenosine (m6A) is a ubiquitous epigenetic RNA modification that plays a pivotal role in tumour development and metastasis. In this study, we aimed to investigate the expression profiling, clinical significance, biological function and the regulation of m6A-related genes in hepatoblastoma (HB). Materials and Methods The mRNA and protein expression levels of m6A-related genes were analysed using Gene Expression Omnibus (GEO) and tissue microarray (TMA) cohort. Kaplan-Meier analysis was performed to evaluate the prognostic value of m6A-related genes in HB. Knockdown of m6A-related genes was conducted to analyse its function on cell proliferation, migration and invasion. Furthermore, bioinformatics analysis and experimental verification were used to explore the potential molecular mechanism and signalling pathway. Results We found that most m6A-related genes were significantly upregulated in HB tumour tissues. High levels of methyltransferase-like 3 (METTL3, P = .013), YTHDF2 (P = .037) and FTO (P = .032) indicated poor clinical outcomes, and the upregulation of METTL3 was an independent prognostic factor in HB patients. Functional assays showed that knockdown of METTL3 could dramatically suppress the proliferation, migration and invasion of HB cells. In addition, METTL3 was identified to be a direct target of microRNA-186 (miR-186). Consistently, miR-186 was low expressed in HB tumour tissues. Moreover, overexpression of miR-186 significantly inhibited cell aggressive phenotype both in vitro and in vivo, while the inhibitory effect could be reversed by METTL3 overexpression. Mechanism study indicated that miR-186/METTL3 axis contributed to the progression of HB via the Wnt/beta-catenin signalling pathway. Conclusions M6A-related genes were frequently dysregulated in HB. miR-186/METTL3/Wnt/beta-catenin axis might serve as novel therapeutic targets and prognostic biomarkers in HB.

摘要: Objectives Alveolar bone osteoporosis has attracted more and more attention because of its profound impact on stomatognathic function and treatment, but current treatments have not been targeted to alveolar bone and might even cause severe side effects. Thus, identifying the effects of anti-osteoporosis agents on alveolar bone is essential. Icariin ameliorates metabolic dysfunction of long bones, but its effects on alveolar bone remain unclarified. Materials and methods BMSCs were isolated from rat mandibles (mBMSCs). The osteogenic potential of mBMSCs and the signalling pathway involved under icariin treatment were measured by ALP and alizarin red staining, reverse transcription-polymerase chain reaction (RT-PCR), Western blotting and immunofluorescence. Dual-luciferase assay, chromatin immunoprecipitation (ChIP) and co-immunoprecipitation were used to investigate the molecular mechanism. Ovariectomized and sham-operated rats treated with or without icariin were analysed by micro-CT, TRAP staining and calcein double labelling. Results We found that icariin promoted osteoblast differentiation of mBMSCs. Furthermore, STAT3 was critical for icariin-promoted osteoblast differentiation, as indicated by increased phosphorylation levels in icariin-treated mBMSCs, while preventing STAT3 activation blocked icariin-induced osteoblast differentiation. Mechanistically, icariin-promoted transcription of the downstream osteogenic gene osteocalcin (Ocn) through STAT3 and STAT3 bound to the promoter of Ocn. Notably, icariin prevented the alveolar bone osteoporosis induced by oestrogen deficiency through promoting bone formation. Conclusions For the first time, our work provides evidence supporting the potential application of icariin in promoting osteogenesis and treating alveolar bone osteoporosis.

摘要: The abnormalities of early post-implantation embryos can lead to early pregnancy loss and many other syndromes. However, it is hard to study embryos after implantation due to the limited accessibility. The success of embryo culture in vitro can avoid the challenges of embryonic development in vivo and provide a powerful research platform for research in developmental biology. The biophysical and chemical cues of the microenvironments impart significant spatiotemporal effects on embryonic development. Here, we summarize the main strategies which enable researchers to grow embryos outside of the body while overcoming the implantation barrier, highlight the roles of engineered microenvironments in regulating early embryonic development, and finally discuss the future challenges and new insights of early embryo culture.

摘要: Objectives Mesenchymal stem cells (MSCs) based therapy for bone regeneration has been regarded as a promising method in the clinic. However, hBMSCs with invasive harvesting process and undesirable proliferation rate hinder the extensive usage. HUCMSCs of easier access and excellent performances provide an alternative for the fabrication of tissue-engineered bone construct. Evidence suggested the osteogenesis ability of hUCMSCs was weaker than that of hBMSCs. To address this issue, a co-culture strategy of osteogenically and angiogenically induced hUCMSCs has been proposed since thorough vascularization facilitates the blood-borne nutrition and oxygen to transport in the scaffold, synergistically expediting the process of ossification. Materials and methods Herein, we used osteogenic- and angiogenic-differentiated hUCMSCs for co-culture in screened culture medium to elevate the osteogenic capacity with in vitro studies and finally coupled with 3D TCP scaffold to repair rat's critical-sized calvarial bone defect. By dual-directional induction, hUCMSCs could differentiate into osteoblasts and endothelial cells, respectively. To optimize the co-culture condition, gradient ratios of dual-directional differentiated hUCMSCs co-cultured under different medium were studied to determine the appropriate condition. Results It revealed that the osteogenic- and angiogenic-induced hUCMSCs mixed with the ratio of 3:1 co-cultured in the mixed medium of osteogenic induction medium to endothelial cell induction medium of 3:1 possessed more mineralization nodules. Similarly, ALP and osteogenesis/angiogenesis-related genes expressions were relatively higher. Further evidence of bone defect repair with 3D printed TCP of 3:1 group exhibited better restoration outcomes. Conclusions Our work demonstrated a favourable and convenient approach of dual-directional differentiated hUCMSCs co-culture to improve the osteogenesis, establishing a novel way to fabricate tissue-engineered bone graft with 3D TCP for large bone defect augmentation.

摘要: Objective The aim of this study is to investigate the role and potential mechanism of p75NTR in mineralization in vivo using p75NTR-knockout mice and in vitro using ectomesenchymal stem cells (EMSCs). Materials and methods Femur bone mass and daily incisor mineralization speed were assessed in an in vivo p75NTR-knockout mouse model. The molecular signatures alkaline phosphatase (ALP), collagen type 1 (Col1), melanoma-associated antigen (Mage)-D1, bone sialoprotein (BSP), osteocalcin (OCN), osteopontin (OPN), distal-less homeobox 1 (Dlx1) and Msh homeobox 1 (Msx1) were examined in vitro in EMSCs isolated from p75NTR(+/+) and p75NTR(ExIII-/-) mice. Results p75NTR-knockout mice were smaller in body size than heterozygous and wild-type mice. Micro-computed tomography and structural quantification showed that the osteogenic ability of p75NTR(ExIII)-knockout mice was significantly decreased compared with that of wild-type mice (P < .05). Weaker ALP and alizarin red staining and reduced expression of ALP, Col1, Runx2, BSP, OCN and OPN were also observed in p75NTR(ExIII-/-) EMSCs. Moreover, the distance between calcein fluorescence bands in p75NTR(ExIII)-knockout mice was significantly smaller than that in wild type and heterozygous mice (P < .05), indicating the lower daily mineralization speed of incisors in p75NTR(ExIII)-knockout mice. Further investigation revealed a positive correlation between p75NTR and Mage-D1, Dlx1, and Msx1. Conclusion p75NTR not only promotes osteogenic differentiation and tissue mineralization, but also shows a possible relationship with the circadian rhythm of dental hard tissue formation.