Comprehensive analysis of lncRNA expression profiles in postmenopausal osteoporosis

RUNX2 regulation in osteoblast differentiation: A possible therapeutic function of the lncRNA and miRNA-mediated network

Osteogenic differentiation is a crucial process in the formation of the skeleton and the remodeling of bones. It relies on a complex system of signaling pathways and transcription factors, including Runt-related transcription factor 2 (RUNX2). Non-coding RNAs (ncRNAs) control the bone-specific transcription factor RUNX2 through post-transcriptional mechanisms to regulate osteogenic differentiation. The most research has focused on microRNAs (miRNAs) and long ncRNAs (lncRNAs) in studying how they regulate RUNX2 for osteogenesis in both normal and pathological situations. This article provides a concise overview of the recent advancements in understanding the critical roles of lncRNA/miRNA/axes in controlling the expression of RUNX2 during bone formation. The possible application of miRNAs and lncRNAs as therapeutic agents for the treatment of disorders involving the bones and bones itself is also covered.

From Genomics to Metabolomics: Molecular Insights into Osteoporosis for Enhanced Diagnostic and Therapeutic Approaches

Osteoporosis (OP) is a prevalent skeletal disorder characterized by decreased bone mineral density (BMD) and increased fracture risk. The advancements in omics technologies-genomics, transcriptomics, proteomics, and metabolomics-have provided significant insights into the molecular mechanisms driving OP. These technologies offer critical perspectives on genetic predispositions, gene expression regulation, protein signatures, and metabolic alterations, enabling the identification of novel biomarkers for diagnosis and therapeutic targets. This review underscores the potential of these multi-omics approaches to bridge the gap between basic research and clinical applications, paving the way for precision medicine in OP management. By integrating these technologies, researchers can contribute to improved diagnostics, preventative strategies, and treatments for patients suffering from OP and related conditions.

Harnessing GMNP-loaded BMSC-derived EVs to target miR-3064-5p via MEG3 overexpression: Implications for diabetic osteoporosis therapy in rats

Diabetic osteoporosis (DO) is a significant complication of diabetes, characterized by a decrease in bone mineral density and an increase in fracture risk. Magnetic nanoparticles (GMNPs) have emerged as potential drug carriers for various therapeutic applications. This study investigated the molecular mechanism of GMNPs loaded with bone marrow mesenchymal stem cell (BMSC) derived extracellular vesicles (EVs) overexpressing MEG3 target miR-3064-5p to induce NR4A3 for treating DO in rats. Initial analysis was carried out on GEO datasets GSE7158 and GSE62589, revealing a notable downregulation of NR4A3 in osteoporotic samples. Subsequent in vitro studies demonstrated the effective uptake of BMSC-EVs-MEG3 by osteoblasts and its potential to inhibit miR-3064-5p, activating the PINK1/Parkin signaling pathway and thus promoting mitochondrial autophagy, osteoblast proliferation, and differentiation. In vivo, experiments using DO rat models further substantiated the therapeutic efficacy of GMNPE-EVs-MEG3 in alleviating osteoporosis symptoms. In conclusion, GMNPs loaded with BMSC-EVs, through the delivery of MEG3 targeting miR-3064-5p, can effectively promote NR4A3 expression, activate the PINK1/Parkin pathway, and thereby enhance osteoblast proliferation and differentiation, offering a promising treatment for DO.

LncRNA MALAT1 promotes osteogenic differentiation through the miR-93-5p/SMAD5 axis

OBJECTIVES

Promoting the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) is a way to regenerate periodontal bone. This study aimed to determine whether lncRNA MALAT1 promotes the osteogenic differentiation of human PDLSCs in vitro.

MATERIALS AND METHODS

Human PDLSCs were extracted from the human periodontal ligament, and after osteogenic differentiation was induced using osteogenic medium, the human PDLSCs were transfected with siRNA-MALAT1, miR-93-5p mimics, and miR-93-5p inhibitors. The expression of osteogenesis-related genes was assessed by RT-qPCR and western blotting, alkaline phosphatase (ALP) activity was assessed by ALP activity assay, and the formation of mineralized nodules was assessed by alizarin red S (ARS) staining. RNA immunoprecipitation (RIP) and luciferase assays were performed to assess the binding of MALAT1, miR-93-5p, and SMAD5.

RESULTS

The expression of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was upregulated, while that of miR-93-5p was downregulated after PDLSC osteogenic differentiation. Knockdown of MALAT1 inhibited the osteogenic differentiation of PDLSCs, and MALAT1 expression negatively correlated with miR-93-5p expression. miR-93-5p inhibited the osteogenic differentiation of human PDLSCs by specifically binding to SMAD5.

CONCLUSION

MALAT1 regulates human PDLSC differentiation by regulating the miR-93-5p/SMAD5 axis.

Effect of runx2b deficiency in intermuscular bones on the regulatory network of lncRNA-miRNA-mRNA

Intermuscular bones (IBs) are mineralized spicules that negatively impact the quality and value of fish products. Runx2b is a crucial modulator in promoting bone formation through regulating osteoblast differentiation. Previous studies suggested that loss of runx2b gene completely inhibited IBs formation in zebrafish. However, how the whole transcriptome, including mRNA and non-coding RNA (ncRNA), affects the IBs development in runx2b-/- zebrafish are not known. The aim of this study was to identify the regulatory networks of differentially expressed (DE) lncRNAs, miRNAs, and mRNAs in zebrafish with and without IBs (runx2b+/+ fish and runx2b-/- fish) utilizing high-throughput sequencing techniques. All together there are 1051 mRNAs, 456 lncRNAs, and 18 miRNAs differentially expressed were found between these two strains. The analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) has highlighted significant pathways linked to the development of IBs, specifically the TGF-beta and Wnt signaling pathways, and a number of genes concentrated on these two signaling pathways related to the formation of IBs. Further, 1989 competing endogenous RNA (ceRNA) networks were created according to the correlation among mRNAs, miRNAs and lncRNAs. The ceRNA networks results revealed 52 ceRNA pairs related to the IBs formation, consisting of 52 mRNAs, 37 lncRNAs, and 6 miRNAs. Of these, we found that dre-miR-2189 was the key element of ceRNA pairs, interacting with 19 mRNAs and 11 lncRNAs, and MSTRG.13175.1 could regulate sp7 expression by interacting with dre-miR-2189 to function in osteogenic differentiation. Subsequent experiments at the cellular level also revealed the interaction mechanism. The outcomes indicated a crucial role of miRNAs and lncRNAs in the development of fish IBs, which offer new views into the functions of ncRNAs involved in IBs formation.

Competing endogenous RNAs in human astrocytes: crosstalk and interacting networks in response to lipotoxicity

Neurodegenerative diseases (NDs) are characterized by a progressive deterioration of neuronal function, leading to motor and cognitive damage in patients. Astrocytes are essential for maintaining brain homeostasis, and their functional impairment is increasingly recognized as central to the etiology of various NDs. Such impairment can be induced by toxic insults with palmitic acid (PA), a common fatty acid, that disrupts autophagy, increases reactive oxygen species, and triggers inflammation. Although the effects of PA on astrocytes have been addressed, most aspects of the dynamics of this fatty acid remain unknown. Additionally, there is still no model that satisfactorily explains how astroglia goes from being neuroprotective to neurotoxic. Current incomplete knowledge needs to be improved by the growing field of non-coding RNAs (ncRNAs), which is proven to be related to NDs, where the complexity of the interactions among these molecules and how they control other RNA expressions need to be addressed. In the present study, we present an extensive competing endogenous RNA (ceRNA) network using transcriptomic data from normal human astrocyte (NHA) cells exposed to PA lipotoxic conditions and experimentally validated data on ncRNA interaction. The obtained network contains 7 lncRNA transcripts, 38 miRNAs, and 239 mRNAs that showed enrichment in ND-related processes, such as fatty acid metabolism and biosynthesis, FoxO and TGF-β signaling pathways, prion diseases, apoptosis, and immune-related pathways. In addition, the transcriptomic profile was used to propose 22 potential key controllers lncRNA/miRNA/mRNA axes in ND mechanisms. The relevance of five of these axes was corroborated by the miRNA expression data obtained in other studies. MEG3 (ENST00000398461)/hsa-let-7d-5p/ATF6B axis showed importance in Parkinson's and late Alzheimer's diseases, while AC092687.3/hsa-let-7e-5p/[SREBF2, FNIP1, PMAIP1] and SDCBP2-AS1 (ENST00000446423)/hsa-miR-101-3p/MAPK6 axes are probably related to Alzheimer's disease development and pathology. The presented network and axes will help to understand the PA-induced mechanisms in astrocytes, leading to protection or injury in the CNS under lipotoxic conditions as part of the intricated cellular regulation influencing the pathology of different NDs. Furthermore, the five corroborated axes could be considered study targets for new pharmacologic treatments or as possible diagnostic molecules, contributing to improving the quality of life of millions worldwide.