Human amnion-derived mesenchymal stem cells promote osteogenic differentiation of human bone marrow mesenchymal stem cells via H19/miR-675/APC axis

N6-Methyladenosine in Cell-Fate Determination of BMSCs: From Mechanism to Applications

The methylation of adenosine base at the nitrogen-6 position is referred to as "N6-methyladenosine (m6A)" and is one of the most prevalent epigenetic modifications in eukaryotic mRNA and noncoding RNA (ncRNA). Various m6A complex components known as "writers," "erasers," and "readers" are involved in the function of m6A. Numerous studies have demonstrated that m6A plays a crucial role in facilitating communication between different cell types, hence influencing the progression of diverse physiological and pathological phenomena. In recent years, a multitude of functions and molecular pathways linked to m6A have been identified in the osteogenic, adipogenic, and chondrogenic differentiation of bone mesenchymal stem cells (BMSCs). Nevertheless, a comprehensive summary of these findings has yet to be provided. In this review, we primarily examined the m6A alteration of transcripts associated with transcription factors (TFs), as well as other crucial genes and pathways that are involved in the differentiation of BMSCs. Meanwhile, the mutual interactive network between m6A modification, miRNAs, and lncRNAs was intensively elucidated. In the last section, given the beneficial effect of m6A modification in osteogenesis and chondrogenesis of BMSCs, we expounded upon the potential utility of m6A-related therapeutic interventions in the identification and management of human musculoskeletal disorders manifesting bone and cartilage destruction, such as osteoporosis, osteomyelitis, osteoarthritis, and bone defect.

Regulatory mechanisms of circular RNAs during human mesenchymal stem cell osteogenic differentiation

Human osteogenic differentiation is a complex and well-orchestrated process which involves a plethora of molecular players and cellular processes. A growing number of studies have underlined that circular RNAs (circRNAs) play an important regulatory role during human osteogenic differentiation. CircRNAs are single-stranded, covalently closed non-coding RNA molecules that are acquiring increased attention as epigenetic regulators of gene expression. Given their intrinsic high conformational stability, abundance, and specificity, circRNAs can undertake various biological activities in order to regulate multiple cellular processes, including osteogenic differentiation. The most recent evidence indicates that circRNAs control human osteogenesis by preventing the inhibitory activity of miRNAs on their downstream target genes, using a competitive endogenous RNA mechanism. The aim of this review is to draw attention to the currently known regulatory mechanisms of circRNAs during human osteogenic differentiation. Specifically, we provide an understanding of recent advances in research conducted on various human mesenchymal stem cell types that underlined the importance of circRNAs in regulating osteogenesis. A comprehensive understanding of the underlying regulatory mechanisms of circRNA in osteogenesis will improve knowledge on the molecular processes of bone growth, resulting in the potential development of novel preclinical and clinical studies and the discovery of novel diagnostic and therapeutic tools for bone disorders.

Long noncoding RNA (lncRNA) H19: An essential developmental regulator with expanding roles in cancer, stem cell differentiation, and metabolic diseases

Recent advances in deep sequencing technologies have revealed that, while less than 2% of the human genome is transcribed into mRNA for protein synthesis, over 80% of the genome is transcribed, leading to the production of large amounts of noncoding RNAs (ncRNAs). It has been shown that ncRNAs, especially long non-coding RNAs (lncRNAs), may play crucial regulatory roles in gene expression. As one of the first isolated and reported lncRNAs, H19 has gained much attention due to its essential roles in regulating many physiological and/or pathological processes including embryogenesis, development, tumorigenesis, osteogenesis, and metabolism. Mechanistically, H19 mediates diverse regulatory functions by serving as competing endogenous RNAs (CeRNAs), Igf2/H19 imprinted tandem gene, modular scaffold, cooperating with H19 antisense, and acting directly with other mRNAs or lncRNAs. Here, we summarized the current understanding of H19 in embryogenesis and development, cancer development and progression, mesenchymal stem cell lineage-specific differentiation, and metabolic diseases. We discussed the potential regulatory mechanisms underlying H19's functions in those processes although more in-depth studies are warranted to delineate the exact molecular, cellular, epigenetic, and genomic regulatory mechanisms underlying the physiological and pathological roles of H19. Ultimately, these lines of investigation may lead to the development of novel therapeutics for human diseases by exploiting H19 functions.

Apelin-13, a regulator of autophagy, apoptosis and inflammation in multifaceted bone protection

Apelin/APJ is widely distributed in various tissues in the body and participates in the regulation of physiological and pathological mechanisms such as autophagy, apoptosis, inflammation, and oxidative stress. Apelin-13 is an adipokine family member with multiple biological roles and has been shown to be involved in the development and progression of bone diseases. In the process of osteoporosis and fracture healing, Apelin-13 plays an osteoprotective role by regulating the autophagy and apoptosis of BMSCs, and promotes the osteogenic differentiation of BMSCs. In addition, Apelin-13 also attenuates the progression of arthritis by regulating the inflammatory response of macrophages. In conclusion, Apelin-13 has an important connection with bone protection, which provides a new strategy for the clinical treatment of bone-related diseases.

The Common LncRNAs of Neuroinflammation-Related Diseases

Spatio-temporal specific long noncoding RNAs (lncRNAs) play important regulatory roles not only in the growth and development of the brain but also in the occurrence and development of neurologic diseases. Generally, the occurrence of neurologic diseases is accompanied by neuroinflammation. Elucidation of the regulatory mechanisms of lncRNAs on neuroinflammation is helpful for the clinical treatment of neurologic diseases. This paper focuses on recent findings on the regulatory effect of lncRNAs on neuroinflammatory diseases and selects 10 lncRNAs that have been intensively studied to analyze their mechanism action. The clinical treatment status of lncRNAs as drug targets is also reviewed. SIGNIFICANCE STATEMENT: Gene therapies such as clustered regularly interspaced short palindrome repeats technology, antisense RNA technology, and RNAi technology are gradually applied in clinical treatment, and the development of technology is based on a large number of basic research investigations. This paper focuses on the mechanisms of lncRNAs regulation of neuroinflammation, elucidates the beneficial or harmful effects of lncRNAs in neurosystemic diseases, and provides theoretical bases for lncRNAs as drug targets.

Role of mechano-sensitive non-coding RNAs in bone remodeling of orthodontic tooth movement: recent advances

Orthodontic tooth movement relies on bone remodeling and periodontal tissue regeneration in response to the complicated mechanical cues on the compressive and tensive side. In general, mechanical stimulus regulates the expression of mechano-sensitive coding and non-coding genes, which in turn affects how cells are involved in bone remodeling. Growing numbers of non-coding RNAs, particularly mechano-sensitive non-coding RNA, have been verified to be essential for the regulation of osteogenesis and osteoclastogenesis and have revealed how they interact with signaling molecules to do so. This review summarizes recent findings of non-coding RNAs, including microRNAs and long non-coding RNAs, as crucial regulators of gene expression responding to mechanical stimulation, and outlines their roles in bone deposition and resorption. We focused on multiple mechano-sensitive miRNAs such as miR-21, - 29, -34, -103, -494-3p, -1246, -138-5p, -503-5p, and -3198 that play a critical role in osteogenesis function and bone resorption. The emerging roles of force-dependent regulation of lncRNAs in bone remodeling are also discussed extensively. We summarized mechano-sensitive lncRNA XIST, H19, and MALAT1 along with other lncRNAs involved in osteogenesis and osteoclastogenesis. Ultimately, we look forward to the prospects of the novel application of non-coding RNAs as potential therapeutics for tooth movement and periodontal tissue regeneration.

MicroRNA-loaded biomaterials for osteogenesis

The large incidence of bone defects in clinical practice increases not only the demand for advanced bone transplantation techniques but also the development of bone substitute materials. A variety of emerging bone tissue engineering materials with osteogenic induction ability are promising strategies for the design of bone substitutes. MicroRNAs (miRNAs) are a class of non-coding RNAs that regulate intracellular protein expression by targeting the non-coding region of mRNA3′-UTR to play an important role in osteogenic differentiation. Several miRNA preparations have been used to promote the osteogenic differentiation of stem cells. Therefore, multiple functional bone tissue engineering materials using miRNA as an osteogenic factor have been developed and confirmed to have critical efficacy in promoting bone repair. In this review, osteogenic intracellular signaling pathways mediated by miRNAs are introduced in detail to provide a clear understanding for future clinical treatment. We summarized the biomaterials loaded with exogenous cells engineered by miRNAs and biomaterials directly carrying miRNAs acting on endogenous stem cells and discussed their advantages and disadvantages, providing a feasible method for promoting bone regeneration. Finally, we summarized the current research deficiencies and future research directions of the miRNA-functionalized scaffold. This review provides a summary of a variety of advanced miRNA delivery system design strategies that enhance bone regeneration.

Effects of Resveratrol, Curcumin and Quercetin Supplementation on Bone Metabolism—A Systematic Review

Phenolic compounds are natural phytochemicals that have recently reported numerous health benefits. Resveratrol, curcumin, and quercetin have recently received the most attention among these molecules due to their documented antioxidant effects. The review aims to investigate the effects of these molecules on bone metabolism and their role in several diseases such as osteopenia and osteoporosis, bone tumours, and periodontitis. The PubMed/Medline, Web of Science, Google Scholar, Scopus, Cochrane Library, and Embase electronic databases were searched for papers in line with the study topic. According to an English language restriction, the screening period was from January 2012 to 3 July 2022, with the following Boolean keywords: (“resveratrol” AND “bone”); (“curcumin” AND “bone”); (“quercetin” AND “bone”). A total of 36 papers were identified as relevant to the purpose of our investigation. The studies reported the positive effects of the investigated phenolic compounds on bone metabolism and their potential application as adjuvant treatments for osteoporosis, bone tumours, and periodontitis. Furthermore, their use on the titanium surfaces of orthopaedic prostheses could represent a possible application to improve the osteogenic processes and osseointegration. According to the study findings, resveratrol, curcumin, and quercetin are reported to have a wide variety of beneficial effects as supplement therapies. The investigated phenolic compounds seem to positively mediate bone metabolism and osteoclast-related pathologies.

Long non-coding RNA SNHG5 promotes the osteogenic differentiation of bone marrow mesenchymal stem cells via the miR-212-3p/GDF5/SMAD pathway

Background

The treatment of bone loss has posed a challenge to clinicians for decades. Thus, it is of great significance to identify more effective methods for bone regeneration. However, the role and mechanisms of long non-coding RNA small nucleolar RNA host gene 5 (SNHG5) during osteogenic differentiation remain unclear.

Methods

We investigated the function of SNHG5, Yin Yang 1 (YY1), miR-212-3p and growth differentiation factor 5 (GDF5) in osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) in vitro and in vivo. Molecular mechanisms were clarified by chromatin immunoprecipitation assay and dual luciferase reporter assay.

Results

We found SNHG5 expression was upregulated during osteogenesis of hBMSCs. Knockdown of SNHG5 in hBMSCs inhibited osteogenic differentiation while overexpression of SNHG5 promoted osteogenesis. Moreover, YY1 transcription factor directly bound to the promoter region of SNHG5 and regulated SNHG5 expression to promote osteogenesis. Dual luciferase reporter assay confirmed that SNHG5 acted as a miR-212-3p sponge and miR-212-3p directly targeted GDF5 and further activated Smad1/5/8 phosphorylation. miR-212-3p inhibited osteogenic differentiation, while GDF5 promoted osteogenic differentiation of hBMSCs. In addition, calvarial defect experiments showed knockdown of SNHG5 and GDF5 inhibited new bone formation in vivo.

Conclusion

Our results demonstrated that the novel pathway YY1/SNHG5/miR-212-3p/GDF5/Smad regulates osteogenic differentiation of hBMSCs and may serve as a potential target for the treatment of bone loss.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02781-8.

Quercetin promotes bone marrow mesenchymal stem cell proliferation and osteogenic differentiation through the H19/miR-625-5p axis to activate the Wnt/β-catenin pathway

Background

Quercetin and H19 can promote osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). However, whether quercetin regulates H19 expression to promote osteogenic differentiation of BMSCs is unclear.

Methods

BMSC proliferation, matrix mineralization, and alkaline phosphatase (ALP) activity were assessed using the Cell Counting Kit-8, ALP assay kit, and alizarin red staining kit, respectively. Expression of H19, miR-625-5p, BMP-2, osteocalcin, and RUNX2 were measured by qRT-PCR; β-catenin protein level was measured by western blotting.

Results

Quercetin promoted BMSC proliferation, enhanced ALP activity, and upregulated the expression of BMP-2, osteocalcin, and RUNX2 mRNAs, suggesting that it promoted osteogenic differentiation of BMSCs. Moreover, quercetin increased H19 expression, while the effect of quercetin on BMSCs was reversed by silencing H19 expression. Additionally, miR-625-5p, interacted with H19, was downregulated during quercetin-induced BMSC osteogenic differentiation, which negatively correlated with H19 expression. Silencing miR-625-5p expression promoted BMSC proliferation and osteogenic differentiation, whereas miR-625-5p overexpression weakened the effect of quercetin on BMSCs. Finally, quercetin treatment or downregulation of miR-625-5p expression increased β-catenin protein level in BMSCs. Upregulation or downregulation of miR-625-5p or H19 expression, respectively, inhibited β-catenin protein level in quercetin treated-BMSCs.

Conclusion

H19 promotes, while miR-625-5p inhibits BMSC osteogenic differentiation. Quercetin activates the Wnt/β-catenin pathway and promotes BMSC osteogenic differentiation via the H19/miR-625-5p axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03418-8.

The role and mechanism of long non-coding RNA H19 in stem cell osteogenic differentiation

Background

In recent years, H19, as one of the most well-known long non-coding RNA, has been reported to play important roles in many biological and physiological processes. H19 has been identified to regulate the osteogenic differentiation of various stem cells in many studies. However, the detailed role and regulation mechanism of H19 was not consistent in the reported studies.

Main body of the manuscript

In this review article we summarized the effect and mechanism of lncRNA H19 on osteogenic differentiation of various stem cells reported in the published literatures. The role and mechanism of H19, H19 expression changes, effect of H19 on cell proliferation in osteogenic differentiation were respectively reviewed.

Conclusions

An increasing number of studies have provided evidence that H19 play its role in the regulation of stem cell osteogenic differentiation by different mechanisms. Most of the studies favored the positive regulatory effect of H19 through lncRNA-miRNA pathway. The function and underlying mechanisms by which H19 contributes to osteogenic differentiation require further investigation.

MicroRNA in Implant Dentistry: From Basic Science to Clinical Application

Specific microRNA (miRNA) expression profiles have been reported to be predictive of specific clinical outcomes of dental implants and might be used as biomarkers in implant dentistry with diagnostic and prognostic purposes. The aim of the present narrative review was to summarize current knowledge regarding the use of miRNAs in implant dentistry. The authors attempted to identify all available evidence on the topic and critically appraise it in order to lay the foundation for the development of further research oriented towards the clinical application of miRNAs in implant dentistry.

Long Non-coding RNAs and MicroRNAs Interplay in Osteogenic Differentiation of Mesenchymal Stem Cells

Long non-coding RNAs (lncRNAs) have gained great attention as epigenetic regulators of gene expression in many tissues. Increasing evidence indicates that lncRNAs, together with microRNAs (miRNAs), play a pivotal role in osteogenesis. While miRNA action mechanism relies mainly on miRNA-mRNA interaction, resulting in suppressed expression, lncRNAs affect mRNA functionality through different activities, including interaction with miRNAs. Recent advances in RNA sequencing technology have improved knowledge into the molecular pathways regulated by the interaction of lncRNAs and miRNAs. This review reports on the recent knowledge of lncRNAs and miRNAs roles as key regulators of osteogenic differentiation. Specifically, we described herein the recent discoveries on lncRNA-miRNA crosstalk during the osteogenic differentiation of mesenchymal stem cells (MSCs) derived from bone marrow (BM), as well as from different other anatomical regions. The deep understanding of the connection between miRNAs and lncRNAs during the osteogenic differentiation will strongly improve knowledge into the molecular mechanisms of bone growth and development, ultimately leading to discover innovative diagnostic and therapeutic tools for osteogenic disorders and bone diseases.

Human amnion-derived mesenchymal stem cells promote osteogenic differentiation of lipopolysaccharide-induced human bone marrow mesenchymal stem cells via ANRIL/miR-125a/APC axis

BACKGROUND AND AIM

Periodontitis is a chronic inflammatory disease inducing the absorption of alveolar bone and leading to tooth loss. Human amnion-derived mesenchymal stem cells (HAMSCs) have been used for studying inflammatory processes. This study aimed to explore the role of long noncoding RNA (lncRNA) antisense noncoding RNA in the INK4 locus (ANRIL) in HAMSC-driven osteogenesis in lipopolysaccharide (LPS)-induced human bone marrow mesenchymal stem cells (HBMSCs).

METHODS

The cells were incubated with a co-culture system. Reactive oxygen species (ROS) level and superoxide dismutase (SOD) activity were used to detect the oxidative stress level. Flow cytometry was performed to determine cell proliferation. The alkaline phosphatase (ALP) activity, Alizarin red assay, cell transfection, and rat mandibular defect model were used to evaluate the osteogenic differentiation. Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, dual-luciferase reporter assay, and immunofluorescence staining were used to evaluate the molecular mechanisms.

RESULTS

This study showed that HAMSCs promoted the osteogenesis of LPS-induced HBMSCs, while the ANRIL level in HBMSCs decreased during co-culture. ANRIL had no significant influence on the proliferation of LPS-induced HBMSCs. However, its overexpression inhibited the HAMSC-driven osteogenesis in vivo and in vitro, whereas its knockdown reversed these effects. Mechanistically, this study found that downregulating ANRIL led to the overexpression of microRNA-125a (miR-125a), and further contributed to the competitive binding of miR-125a and adenomatous polyposis coli (APC), thus significantly activating the Wnt/β-catenin pathway.

CONCLUSION

The study indicated that HAMSCs promoted the osteogenic differentiation of LPS-induced HBMSCs via the ANRIL/miR-125a/APC axis, and offered a novel approach for periodontitis therapy.

Human Amniotic Mesenchymal Stem Cells Promote Endogenous Bone Regeneration

Bone regeneration has become a research hotspot and therapeutic target in the field of bone and joint medicine. Stem cell-based therapy aims to promote endogenous regeneration and improves therapeutic effects and side-effects of traditional reconstruction of significant bone defects and disorders. Human amniotic mesenchymal stem cells (hAMSCs) are seed cells with superior paracrine functions on immune-regulation, anti-inflammation, and vascularized tissue regeneration. The present review summarized the source and characteristics of hAMSCs and analyzed their roles in tissue regeneration. Next, the therapeutic effects and mechanisms of hAMSCs in promoting bone regeneration of joint diseases and bone defects. Finally, the clinical application of hAMSCs from current clinical trials was analyzed. Although more studies are needed to confirm that hAMSC-based therapy to treat bone diseases, the clinical application prospect of the approach is worth investigating.