microRNA-148a-3p-targeting p300 protects against osteoblast differentiation and osteoporotic bone reconstruction

Mechanosensitive lncRNA H19 promotes chondrocyte autophagy, but not pyroptosis, by targeting miR-148a in post-traumatic osteoarthritis

OBJECTIVE

Investigating whether mechanosensitive lncRNA H19 can directly target miR-148a to alleviate cartilage damage in post-traumatic osteoarthritis (PTOA).

METHODS

Thirty-two female rats were randomly divided into four groups: Sham-operated group (Sham group, n = 8), treadmill running group (R group, n = 8), anterior cruciate ligament transection (ACLT) group (ACLT group, n = 8), and ACLT + treadmill running group (ACLT + R group, n = 8). Histological evaluation was performed to observe the pathological changes in the cartilage of the rat knee. Micro-CT was performed to detect the bone morphological changes in the subchondral bone. RT-qPCR and Western-Blot were performed to detect changes in mRNA and protein levels of metabolic and inflammatory factors as well as changes in the expression of lncRNA H19 and miR-148a in cartilage. The Flexcell 5000™ Tension System was used to further validate that lncRNA H19 has mechanosensitivity in vitro. Finally, cell transfection techniques were used to knock down the expression of lncRNA H19 in chondrocytes to validate the regulatory role of lncRNA H19/miR-148a in cartilage metabolism.

RESULTS

ACLT combined with treadmill running aggravated the abnormal hyperplasia of subchondral bone in the lateral tibial plateau of the rat knee joint, disturbed the balance of cartilage metabolism, induced cartilage inflammatory response and chondrocyte pyroptosis, which eventually led to cartilage damage and PTOA. Importantly, we found that the expression of lncRNA H19 was significantly downregulated in the cartilage of the ACLT + R group. Bioinformatics analysis revealed that miR-148a may be a direct target of lncRNA H19. Subsequently, we focused on the mechanosensitive of lncRNA H19. Subsequently, moderate-intensity mechanical tension stress reversed the expression of lncRNA H19 and autophagy-related factors in inflammatory chondrocytes, while miR-148a showed an opposite expression trend, demonstrating that mechanosensitive lncRNA H19 may be involved in regulating the chondrocyte inflammatory response by targeting miR-148a and activating autophagy. Cell transfection experiments revealed that lncRNA H19 knockdown upregulated miR-148a expression and significantly inhibited the autophagy level of chondrocytes without significant alteration of chondrocyte pyroptosis, which in turn exacerbated the inflammatory response of chondrocytes.

CONCLUSIONS

Mechanosensitive lncRNA H19 can promote chondrocyte autophagy rather than pyroptosis by targeting miR-148a, thus alleviating cartilage damage in PTOA. LncRNA H19 may be a potential therapeutic target for PTOA.

The characteristic expression of circulating MicroRNAs in osteoporosis: a systematic review and meta-analysis

Objective

To evaluate the characteristics of the circulating microRNA expression profiles in patients with osteoporosis.

Methods

A systematic literature search was performed using the Web of Science, PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP, and WANFANG databases from inception until 1 March 2024. The search strategy employed keywords, encompassing "osteoporosis", "bone loss", or "osteopenia" and "miRNA" or "microRNA". The Newcastle-Ottawa Scale (NOS) quality assessment scale was used to evaluate the methodological quality. Heterogeneity tests and statistical analyses of all data were performed by Stata 16.0. The differences in microRNA levels between groups were illustrated by the weighted mean difference (WMD) and 95% confidence interval (95% CI).

Results

A total of 27 studies were included and analyzed in the meta-analysis, with 2,263 participants. The results showed that miR-21-5p (WMD 0.88, 95% CI: 0.22 to 1.55), miR-125b-5p (WMD 6.63, 95% CI: 0.19 to 13.08), miR-483-5p(WMD 6.43, 95% CI: 3.26 to 9.61), miR-133a (WMD 1.43, 95% CI: 1.39 to 1.47), miR-422a (WMD 1, 95% CI: 0.28 to 1.72), and miR-214-3p (WMD 2.03, 95% CI: 0.14 to 3.92) were significantly upregulated, and miR-497-5p (WMD -0.57, 95% CI: -0.98 to -0.17) was significantly downregulated.

Conclusion

miR-21-5p, miR-125b-5p, miR-483-5p, miR-133a, miR-497-5p, miR-422a, and miR-214-3p might serve as potential diagnostic biomarkers for osteoporosis. In the future, integrating these miRNAs to build a diagnostic model might be a promising diagnosis strategy for osteoporosis.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/ , identifier CRD42023481209.

Roles of NOC3L and DDX17 in acquired immunodeficiency complicated with viral myocarditis and osteoporosis

Acquired immunodeficiency syndrome is a systemic infectious disease caused by human immunodeficiency virus infection, which could attack the bones and heart. However, the relationship between Nuclear Complex Associated 3 Homolog (NOC3L) and DEAD box helicase 17 (DDX17) and acquired immunodeficiency complicated with viral myocarditis and osteoporosis is unclear. The acquired immune deficiency dataset GSE140713, GSE147162 and the osteoporosis dataset (GSE230665), and viral myocarditis dataset (GSE150392) configuration files were generated from gene expression omnibus. The differentially expressed genes (DEGs) were screened and performed weighted gene co-expression network analysis. Construction and analysis of protein-protein interaction network. Functional enrichment analysis, gene set enrichment analysis, immune infiltration analysis, gene expression heatmap, and comparative toxicogenomics database analysis were performed. TargetScan screens miRNAs of DEGs. Thousand three hundred thirty-five DEGs were identified. According to gene ontology, they are mainly concentrated in the regulation of RNA biosynthesis, cytoplasmic ribosome, and the DNA binding transcription factor activity. In Kyoto Encyclopedia of Genes and Genomes analysis, they are mainly concentrated in TGF-β signal pathway, Notch signaling pathway, cAMP signaling pathway, and Apelin signaling pathway. Gene set enrichment analysis shows that DEGs are mainly enriched in cytoplasmic ribosome, transcriptional regulator activity, DNA binding transcription factor activity, TGF-β signal pathway, and Notch signal pathway. In the enrichment project of Metascape, tyrosine kinase receptor signaling, growth regulation, and enzyme-linked receptor protein signaling pathways can be seen in the gene ontology enrichment project. Four core genes (NOC3L, WDR46, SDAD1, and DDX17) were obtained. Core genes (NOC3L, WDR46, SDAD1, and DDX17) were low expressed in both acquired immunodeficiency and osteoporosis samples. Comparative toxicogenomics database analysis showed that core genes (NOC3L, WDR46, SDAD1, and DDX17) were associated with inflammation necrosis. The expressions of NOC3L and DDX17 are low in acquired immunodeficiency combined with viral myocarditis and osteoporosis.

Surgical suction filter-derived bone graft displays osteogenic miRNA and mRNA patterns

PURPOSE

Recently, a surgical suction filter device was introduced which aims at generating a suction filter-derived bone grafting substitute (SF-BGS). The osteogenic capacity of this grafting material, however, is unclear. MicroRNAs (miRNAs) and osteogenic mRNAs may influence these processes. The aim of this study was therefore to investigate the quality of the SF-BGS by determining the expression of miRNAs and osteogenic mRNAs.

METHODS

Samples were collected during non-union surgery. Upon exposure of the intramedullary canal, the surgical vacuum system was fitted with the suction filter device containing collagen complex and synthetic β-TCP: (Ca3(PO4)2, granule size 5-8 mm, total volume 10 mL (Cerasorb Foam®, Curasan AG, Kleinostheim, Germany). As a control, venous blood was used as in current clinical practice. Samples were snap-frozen and mechanically disrupted. MiRNAs and mRNAs were isolated, transcribed, and pooled for qPCR analysis. Lastly, mRNA targets were determined through in silico target analyses.

RESULTS

The study population consisted of seven patients with a posttraumatic long bone non-union (4♀; mean age 54 ± 16 years). From the array data, distinct differences in miRNA expression were found between the SF-BGS and control samples. Osteogenic marker genes were overall upregulated in the SF-BGS. Qiagen IPA software identified 1168 mRNA targets for 43 of the overall deregulated miRNAs.

CONCLUSION

This study revealed distinctly deregulated and exclusively expressed osteogenic miRNAs in SF-BGS, as well as overall enhanced osteogenic marker gene expression, as compared to the venous blood control group. These expression profiles were not seen in control samples, indicating that the derived material displays an osteogenic profile. It may therefore be a promising tool to generate a BGS or graft extender when needed.

Circ_KIAA0922 regulates Saos-2 cell proliferation and osteogenic differentiation by regulating the miR-148a-3p/SMAD5 axis and activating the TGF-β signaling pathway

Circular RNAs (circRNAs) are emerging as important regulators in human disease, but their function in osteoporosis (OP) is not sufficiently known. The aim of this study was to identify the possible molecular mechanism of circ_KIAA0922 in osteogenic differentiation of Saos-2 cells in vitro and the interactions among circ_KIAA0922, miR-148a-3p, and SMAD family member 5 (SMAD5). Circ_ KIAA0922, miR-148a-3p, and SMAD5 were overexpressed by transient transfection. Dual-luciferase reporter assay system was used to analyze the combination among circ_KIAA0922, miR-148a-3p, and SMAD5. In addition, the levels of circ_KIAA0922, miR-148a-3p, SMAD5, osteocalcin (OCN), and runt-related transcription factor 2 (RUNX2) were detected using RT-qPCR or western blot analysis. Alizarin red staining was performed to analyze the degree of osteogenic differentiation under the control of circ_KIAA0922, miR-148a-3p, and SMAD5. We found that circ_KIAA0922 knockdown inhibited the proliferation and osteogenic differentiation of Saos-2 cells. Circ_KIAA0922 directly targeted miR-148a-3p, and miR-148a-3p inhibition reversed the effects of circ_KIAA0922 knockdown on the proliferation and osteogenic differentiation of Saos-2 cells. Overexpression of SMAD5 promoted the proliferation and osteogenic differentiation of Saos-2 cells and attenuated the inhibitory effect of miR-148a-3p on cell proliferation and osteogenic differentiation. In conclusion, circ_ KIAA0922 facilitated Saos-2 cell proliferation and osteogenic differentiation via the circ_KIAA0922/ miR-148a-3p/ SMAD5 axes in vitro, thus providing insights into the mechanism of osteogenic differentiation by circ_ KIAA0922.

Osteoblast-Derived Matrix Vesicles Exhibit Exosomal Traits and a Unique Subset of microRNA: Their Caveolae-Dependent Endocytosis Results in Reduced Osteogenic Differentiation

Matrix vesicles (MVs) are nano-sized extracellular vesicles that are anchored in the extracellular matrix (ECM). In addition to playing a role in biomineralization, osteoblast-derived MVs were recently suggested to have regulatory duties. The aims of this study were to establish the characteristics of osteoblast-derived MVs in the context of extracellular vesicles like exosomes, assess their role in modulating osteoblast differentiation, and examine their mechanism of uptake. MVs were isolated from the ECM of MG63 human osteoblast-like cell cultures and characterized via enzyme activity, transmission electron microscopy, nanoparticle tracking analysis, Western blot, and small RNA sequencing. Osteoblasts were treated with MVs from two different culture conditions (growth media [GM]; osteogenic media [OM]) to evaluate their effects on the differentiation and production of inflammatory markers and on macrophage polarization. MV endocytosis was assessed using a lipophilic, fluorescent dye and confocal microscopy with the role of caveolae determined using methyl-β-cyclodextrin. MVs exhibited a four-fold enrichment in alkaline phosphatase specific activity compared to plasma membranes; were 50-150 nm in diameter; possessed exosomal markers CD63, CD81, and CD9 and endosomal markers ALIX, TSG101, and HSP70; and were selectively enriched in microRNA linked to an anti-osteogenic effect and to M2 macrophage polarization. Treatment with GM or OM MVs decreased osteoblast differentiation. Osteoblasts endocytosed MVs using a mechanism that involves caveolae. These results support the hypothesis that osteoblasts produce MVs that participate in the regulation of osteogenesis.

MiR-148a deletion protects from bone loss in physiological and estrogen-deficient mice by targeting NRP1

Bone metabolic homeostasis is largely dependent on the dynamic balance between osteoblasts and osteoclasts. MicroRNAs (miRNAs) play critical roles in regulating bone metabolism. In this study, we explored the role of a new miRNA (miR-148a) in osteoporosis. We compared the bone phenotype between miR-148a knockout (KO) mice and the wild-type (WT) littermates. We found miR-148a KO mice exhibited an increased bone mass phenotype and decreased osteoclastogenesis compared to the WT group. In vitro, miR-148a overexpression promoted osteoclastogenesis and bone resorption function. Mechanistically, NRP1 was identified as a novel direct target of miR-148a, and NRP1 silencing reversed the effect of miR-148a knockout. In OVX and calvarial osteolysis models, miR-148a KO protects mice against excessive bone resorption, while miR-148a agomiR/AAV-shNRP1 accelerates pathologic bone loss. Finally, the miR-148a level was found to be positively correlated with β-CTX in postmenopausal osteoporosis (PMOP) serum specimens. In summary, our findings revealed that miR-148a genetic deletion ameliorates bone loss under physiological and pathological conditions by targeting NRP1. In osteoclast-related bone metabolic diseases such as PMOP, miR-148a may be an attractive therapeutic target in the future.

Enhancement of Osteoblast Function through Extracellular Vesicles Derived from Adipose-Derived Stem Cells

Adipose-derived stem cells (ADSCs) are a type of mesenchymal stem cell that is investigated in bone tissue engineering (BTE). Osteoblasts are the main cells responsible for bone formation in vivo and directing ADSCs to form osteoblasts through osteogenesis is a research topic in BTE. In addition to the osteogenesis of ADSCs into osteoblasts, the crosstalk of ADSCs with osteoblasts through the secretion of extracellular vesicles (EVs) may also contribute to bone formation in ADSC-based BTE. We investigated the effect of ADSC-secreted EVs (ADSC-EVs) on osteoblast function. ADSC-EVs (size ≤ 1000 nm) were isolated from the culture supernatant of ADSCs through ultracentrifugation. The ADSC-EVs were observed to be spherical under a transmission electron microscope. The ADSC-EVs were positive for CD9, CD81, and Alix, but β-actin was not detected. ADSC-EV treatment did not change survival but did increase osteoblast proliferation and activity. The 48 most abundant known microRNAs (miRNAs) identified within the ADSC-EVs were selected and then subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The GO analysis revealed that these miRNAs are highly relevant to skeletal system morphogenesis and bone development. The KEGG analysis indicated that these miRNAs may regulate osteoblast function through autophagy or the mitogen-activated protein kinase or Ras-related protein 1 signaling pathway. These results suggest that ADSC-EVs enhance osteoblast function and can contribute to bone regeneration in ADSC-based BTE.