Small interfering RNAs in the management of human rheumatoid arthritis

Clinical significance of microRNA-328-3p and bone metabolism biomarkers in gout patients with different musculoskeletal ultrasonography imaging

AIMS

MicroRNA (miRNA) participates in the pathophysiological processes of multiple metabolic diseases, including gout. In gout patients, there is concomitant derangement of bone metabolism. The study aimed to explore the correlation of different ultrasonic manifestations and miR-328-3p levels with bone metabolic markers in gout patients.

METHODS

A total of 320 gout patients were grouped according to musculoskeletal ultrasound (MSUS) imaging. Serum osteocalcin (BGP), C-terminal telopeptide of type I collagen (CTX-I) and osteopotin (OPN) levels were detected to evaluate bone metabolism. Serum miR-328-3p levels were detected via qRT-PCR. Pearson's correlation analysis was performed to explore the relationships between the variables.

RESULTS

Patients with tophi accompanied by bone erosion demonstrated significantly elevated levels of BGP and OPN compared to those with tophi or aggregate of MSU crystals in the absence of bone erosions. Cases with long course of disease exhibited more severe bone destruction. Cases without specific clinical manifestations presented the highest levels of serum miR-328-3p, whereas those with bone erosions demonstrated the lowest values. Significantly negative correlations were also detected for serum miR-328-3p levels with BGP and OPN values in all gout patients.

CONCLUSION

Serum miR-328-3p levels were associated with diverse MSUS manifestations in gout patients. MSUS imaging and miR-328-3p levels are capable of reflecting the joint impairment in gout patients.

MiR-103-3p regulates chondrocyte autophagy, apoptosis, and ECM degradation through the PI3K/Akt/mTOR pathway by targeting CPEB3

BACKGROUND

Chondrocyte apoptosis is associated with the severity of cartilage destruction and matrix degeneration in the progression of osteoarthritis. Increasing evidence indicates that autophagy has a significant cytoprotective effect against chondrocyte apoptosis. Here, we investigated the role of microRNA-103-3p (miR-103-3p) in regulating chondrocyte function and elucidated the underlying mechanism.

METHODS

MiR-103-3p expression in interleukin-1β (IL-1β)-stimulated chondrocytes was evaluated using RT-qPCR. The targets of miR-103-3p predicted by online databases were verified using biotin-based pulldown assay and luciferase reporter assay. IL-1β stimulated-chondrocytes were transfected with miR-103-3p inhibitor along with siRNA targeting cytoplasmic polyadenylation element-binding protein3 (siCPEB3), the autophagy inhibitor 3-MA, or the PI3K agonist 740 Y-P. Chondrocyte proliferation was evaluated using cell counting kit-8. Apoptosis was detected by flow cytometry. The levels of apoptosis-, extracellular matrix (ECM)-, autophagy-, and the PI3K/Akt/mTOR pathway-related proteins in chondrocytes were detected using immunoblotting or immunofluorescence.

RESULTS

We found that IL-1β stimulation upregulated miR-103-3p and downregulated CPEB3 in mouse chondrocytes. Inhibiting miR-103-3p reduced IL-1β-induced apoptosis and ECM macromolecule degradation while enhancing autophagy in chondrocytes. MiR-103-3p targeted CPEB3, and its downregulation rescued the expression of level in IL-1β stimulated-chondrocytes. MiR-103-3p downregulation inhibited the PI3K/Akt/mTOR pathway in IL-1β stimulated-chondrocytes by upregulating CPEB3. 3-MA, 740 Y-P, or CPEB3 knockdown counteracted the effect of miR-103-3p downregulation on chondrocyte apoptosis, ECM macromolecule degradation, and autophagy.

CONCLUSION

Overall, inhibition of miR-103-3p reduces IL-1β-induced apoptosis and ECM macromolecule degradation in chondrocytes by enhancing autophagy through the CPEB3/PI3K/Akt/mTOR pathway.

Effect of miR-654-3p targeting EMP1 on osteoblast activity and differentiation in delayed fracture healing

BACKGROUND

Delayed fracture healing (DFH) is a common postoperative complication in fracture patients, and a validated serum marker may aid in the clinical management and improve the prognosis of fracture patients. In this study, we investigated the diagnostic role and potential regulatory mechanisms of miR-654-3p in DFH.

METHODS

73 patients with DFH and 75 patients with normal fracture healing (NFH) were included. Expression of miR-654-3p and EMP1 and several mRNA markers of osteogenic differentiation were evaluated by RT-qPCR. The diagnostic value of miR-654-3p and EMP1 alone and in combination was assessed using ROC curves. Cell proliferation capacity was assessed by CCK-8 and apoptosis rate by flow cytometry. DLR experiments demonstrated the targeting relationship between miR-654-3p and EMP1.

RESULTS

Levels of miR-654-3p were found to be significantly lower in DFH compared to NFH. Following cell differentiation treatment, miR-654-3p levels increased and EMP1 levels decreased. Furthermore, a negative correlation was identified between miR-654-3p and EMP1 target binding and expression levels. The combination of miR-654-3p and EMP1 holds significant diagnostic value for DFH. miR-654-3p high expression can inhibit EMP1 levels, which promotes cell proliferation, increases osteoblast activity and levels of differentiation markers, and decreases the rate of apoptosis.

CONCLUSION

miR-654-3p and EMP1 are aberrantly expressed in DFH, and both have high diagnostic value for DFH. miR-654-3p is involved in the proliferation, differentiation, and apoptotic activities of osteoblasts by regulating the level of EMP1, thus affecting the progression of DFH.

METTL3-mediated m6A modification of circSTAT6 modulates miR-188-3p/Beclin1 axis to promote osteogenic differentiation of mesenchymal stem cells

BACKGROUND

The role of N6-methyladenosine (m6A)-modified circRNAs in disease progression is of great significance. However, the specific impact of m6A modification of circSTAT6 on osteoporosis (OP) is still uncertain.

METHODS

The qRT-PCR was employed to assess the levels of METTL3, circSTAT6, miR-188-3p, and Beclin1. To investigate the interaction between miR-188-3p and circSTAT6 or Beclin, a dual-luciferase reporter assay was performed. To evaluate osteogenic differentiation in bone marrow mesenchymal stem cell (BMSC), western blot analysis was conducted to evaluate the protein expression of osteogenic markers, including ALP, OPN, and Runx2. In addition, alizarin red and alkaline phosphatase (ALP) staining assays were employed to assess osteogenesis.

RESULTS

The findings revealed that the downregulation of circSTAT6 was observed in OP. On the other hand, the overexpression of circSTAT6 was found to enhance the osteogenic differentiation of BMSC. In addition, the involvement of METTL3 in mediating m6A methylation of circSTAT6 was identified, which ultimately promoted osteogenesis. Furthermore, circSTAT6 functioned as an miR-188-3p sponge to regulate the expression of Beclin1. Further study revealed that the osteogenic-enhancing effect caused by circSTAT6 overexpression was counteracted by introducing a miR-188-3p mimic. Similarly, the osteogenic-promoting impact of the miR-188-3p inhibitor was reversed by suppressing Beclin1 expression.

CONCLUSIONS

The present study revealed, for the first time, that METTL3-mediated m6A modification of circSTAT6 regulated the miR-188-3p/Beclin1 axis to promote the osteogenic differentiation of BMSC. These findings offer a potential therapeutic target for the treatment of OP.

Serum miR-519d-3p and BMP2: potential early diagnostic markers and their mechanism in delayed fracture healing

BACKGROUND

Delayed fracture healing (DFH) affects patients' quality of life, and there are limitations in diagnosis by CT scan. The purpose of the study is to evaluate the potential and mechanism of clinical application of miRNAs in DFH for early diagnosis and intervention.

METHODS

Serum samples were obtained from delayed and normal fracture healing patients and the levels of miR-519d-3p and BMP2 were measured by RT-qPCR, and the value of both in the diagnosis of DFH was assessed by ROC curve. Cell viability and apoptosis were monitored using CCK8 kit and flow cytometry, respectively, and mRNA expression of osteogenesis and apoptosis-related genes were detected by RT-qPCR. The molecular interactions were verified using luciferase reporter gene system and RIP technique.

RESULTS

Up-regulation of miR-519d-3p expression and down-regulation of BMP2 in the serum of fracture patients four weeks after surgery can be used as an early warning marker of DFH and a risk factor for poor fracture healing. Further studies showed that overexpression of miR-519d-3p markedly inhibited the expression of RUNX2, OCN and ALP and prevented osteoblast differentiation. Meanwhile, it inhibited cell viability, promoted apoptosis, upregulated Bax and Cleaved-caspase-3 mRNA expression, and downregulated Bcl-2 expression. BMP2, targeted by miR-519d-3p, enhanced osteogenesis and reversed the inhibitory of action miR-519d-3p.

CONCLUSIONS

Serum miR-519d-3p and BMP2 can be used as early diagnostic markers for DFH. miR-519d-3p inhibited osteogenesis by targeting BMP2, which may slow down fracture healing.

MYLK-AS1 improves fracture by targeting miR-146a-5p to regulate cell viability and apoptosis in osteoblasts

BACKGROUND

Delayed fracture healing (DFH) is a significant burden for patients. Therefore, early diagnosis and detection are important for the treatment of DFH. The long non-coding RNA (LncRNA) MYLK-AS1 is abnormally expressed in patients with DFH and has the potential to be used as a diagnostic marker.

METHODS

40 patients with DFH and 87 patients with normal fracture healing were included. The levels of MYLK-AS1, miR-146a-5p and several mRNA markers of osteogenic differentiation were assessed by RT-qPCR. The diagnostic value of MYLK-AS1, miR-146a-5p was assessed using ROC curves. Cell proliferation ability was assessed by CCK-8, and apoptosis rate was detected by flow cytometry. DLR, RIP and RNA pull down assays demonstrated the targeting relationship between MYLK-AS1 and miR-146a-5p.

RESULTS

MYLK-AS1 levels were significantly lower and miR-146a-5p levels were significantly up-regulated in DFH compared to normal healing patients. MYLK-AS1 was found to target miR-146a-5p, and the levels were negatively correlated with each other. MYLK-AS1 with miR-146a-5p is of high value for the diagnosis of DFH. High expression of MYLK-AS1 could inhibit miR-146a-5p levels, support cell proliferation, reduce apoptosis, and increase the levels of osteogenesis-specific matrix proteins and osteogenesis-related regulatory factors.

CONCLUSION

MYLK-AS1 has potential as a diagnostic marker for DFH. By increasing the expression level of MYLK-AS1 in cells can reduce the level of miR-146a-5p, increase the activity of osteoblasts and reduce their apoptosis rate, thus affecting the process of fracture healing.

miR-374-5p inhibits osteogenesis by targeting PTEN/PI3K/AKT signaling pathway

PURPOSE

This study aims to evaluate the effects of miR-374-5p on osteogenesis in rat osteoblasts, validate its target on PTEN, and explore its role in the PTEN/PI3K/AKT signaling pathway during osteoblast differentiation.

METHODS

We transfected 293T cells with miR-374-5p mimics and inhibitors, followed by Western blot and qRT-PCR analyses to assess protein and mRNA expression levels. A dual-luciferase assay was performed to confirm direct targeting. Markers of osteoblast function, such as Runx2, OSX, and OCN, were examined in osteoblasts from rats by qRT-PCR and Western blot. Additionally, we developed a lentiviral vector to overexpress miR-374-5p, which successfully infected rat osteoblast progenitors. Bone formation was subsequently assessed using Alizarin Red staining and ALP activity assays. Finally, rescue experiments were conducted to validate the involvement of the miR-374-5p/PTEN/PI3K/AKT signaling pathway.

RESULTS

Our results demonstrate that miR-374-5p significantly downregulates both the protein and mRNA levels of its target gene PTEN, as confirmed by dual luciferase assays. qRT-PCR and Western blot analyses revealed that osteoblastic markers-including Runx2, OSX, and OCN-were markedly reduced in the miR-374-5p mimic group, whereas an opposite trend was observed in the inhibitor group. In vitro, overexpression of miR-374-5p suppressed osteoblast differentiation, as evidenced by decreased calcium nodule formation and reduced ALP activity compared to controls. Furthermore, co-transfection of miR-374-5p mimics with the PI3K/AKT pathway inhibitor LY294002 in osteoblasts led to significantly lower expression of PI3K/AKT pathway-related genes, and notably, the inhibitory effect of miR-374-5p on osteoblast differentiation was reversed by LY294002 treatment.

CONCLUSION

Our findings indicate that miR-374-5p inhibits osteogenesis in rat osteoblasts by targeting PTEN and modulating the PI3K/AKT signaling pathway.

miR-138-5p inhibits healing of femoral fracture osteogenesis in rats by modulating osteoblast differentiation via SIRT1/FOXO1 axis

BACKGROUND

MicroRNAs have a crucial part to play in maintaining bone formation, signaling, and repair. This research explored the involvement miR-138-5p in modulating osteoblast differentiation in femoral fractures model.

METHODS

The role of mir-138-5p in the healing process of femoral fractures in rats was assessed through micro computed tomography (CT) imaging. After that, qPCR was employed to identify the cellular mRNA expression levels of miR-138-5p, SIRT1, and FoxO1 in either the callus or MC3T3-E1. Next, the protein expression level of Runx2, OPN, OCN and ALP was determined by western blot or ELISA. A dual-luciferase reporter gene assay was implemented to examine the target of miR-138-5p. The quantity of mineralized nodules was measured by means of alizarin red staining.

RESULTS

The miR-138-5p inhibitor promotes the mending of femoral fractures. When it is knocked down, the osteogenic differentiation is promoted, which may be caused by the enhanced activity of ALP and the elevation of the expression of Runx2, OPN and OCN. Meanwhile, an increase in the expression of mir-138-5p impairs the biosynthesis of SIRT1 and FoxO1. When SIRT1 and FoxO1 were downregulated with shRNA, the effect caused by the mir-138-5p inhibitor could be reversed.

CONCLUSION

Our studies uncovered that the overexpressed miR-138-5p might have an inhibitory role in femoral fractures healing by inactivating SIRT1/FOXO1 axis.

LINC00968 accelerates osteogenic differentiation of bone marrow mesenchymal stem cells via the miR-17-5p/STAT3 axis

BACKGROUND

BMSCs with robust osteogenic differentiation capacity can participate in the repair of osteoporotic (OP) bone. Long non-coding RNAs (LncRNAs) serve as crucial regulators of osteogenic differentiation. This study aims to investigate the clinical implications of LINC00968 in OP and elucidate its molecular mechanisms.

METHODS

Patients with OP and controls without OP were enrolled. RT-qPCR was utilized the quantify the levels of LINC00968, miR-17-5p, STAT3, and osteogenic differentiation markers. ROC curve was conducted to evaluate the diagnostic significance. Osteogenic differentiation medium (OM) induced hBMSCs. Flow cytometry was used to examine apoptosis. DLR and RIP assay were performed to validate target binding.

RESULTS

LINC00968 was notably decreased in the serum and bone tissue of patients with OP, whereas it was markedly elevated during osteogenic differentiation of hBMSCs. LINC00968 has 78.65% sensitivity and 71.95% specificity in identifying OP patients from controls. Silencing of LINC00968 sharply diminished ALP activity and osteogenic differentiation markers levels while promoting apoptosis in hBMSCs under OM induction. However, this reduction was notably reversed by the administration of a miR-17-5p inhibitor. Molecularly, miR-17-5p directly targets LINC00968 and STAT3.

CONCLUSIONS

Our results indicate that LINC00968 downregulation is a diagnostic biomarker for OP, facilitating osteogenic differentiation and inhibiting apoptosis via miR-17-5p/STAT3 axis, suggesting a new therapeutic target for OP progression.

MiR-147b-3p promotes osteogenesis by targeting NDUFA4 and PI3K/AKT pathway

BACKGROUND

Osteoporosis (OP) is a progressive metabolic bone disease characterized by impaired bone microarchitecture, decreased bone strength, and dysregulated bone remodeling, leading to an increased risk of fractures. Among osteoporotic fractures, osteoporotic vertebral compression fractures (OVCF) are the most common and can significantly impact patients' quality of life. Growing evidence suggests that microRNAs (miRNAs) play a crucial role in bone homeostasis by regulating osteoblast differentiation, bone metabolism, and remodeling processes. Notably, miR-147b-3p has been found to be downregulated in OVCF; however, its specific role in osteogenic regulation remains largely unknown. Therefore, further investigation is warranted to elucidate the function and underlying mechanism of miR-147b-3p in osteogenic differentiation.

METHODS

The GSE93883 and GSE74209 datasets were retrieved from the Gene Expression Omnibus (GEO) database to investigate specific microRNAs involved in the regulation of osteogenesis. Differential expression of miR-147b-3p and NDUFA4 was assessed between healthy controls and patients with osteoporotic vertebral compression fractures (OVCF) using real-time quantitative PCR.To modulate the expression levels of miR-147b-3p in MC3T3-E1 cells, both the miR-147b-3p mimic and inhibitor were utilized. Cell viability was evaluated via the CCK-8 assay to assess the impact of miR-147b-3p on MC3T3-E1 cell proliferation. Real-time PCR and Western blot analysis were conducted to quantify the expression levels of osteogenic markers across different experimental groups. Alizarin red staining (ARS) was employed to examine the effect of miR-147b-3p on the mineralization capacity of MC3T3-E1 cells. In vivo experiments were performed to evaluate the functional role of miR-147b-3p. Bioinformatics databases were used to predict the potential target gene of miR-147b-3p (NDUFA4), and the predictions were validated by a dual luciferase reporter gene assay.To investigate the regulatory role of the miR-147b-3p/NDUFA4 axis in osteogenic differentiation, MC3T3-E1 cells were transfected with the NDUFA4 overexpression plasmid and miR-147b-3p mimic. Western blot analysis was performed to assess the phosphorylation levels of PI3K and AKT, in order to explore whether the miR-147b-3p/NDUFA4 axis regulates osteogenic differentiation through the PI3K/AKT signaling pathway.

RESULTS

Our results indicated a significant downregulation of miR-147b-3p and a concurrent upregulation of NDUFA4 in patients with osteoporotic vertebral compression fractures (OVCF). A luciferase reporter assay confirmed that NDUFA4 is a direct target gene of miR-147b-3p.To examine the functional role of miR-147b-3p, both in vitro and in vivo experiments were conducted.The experimental findings revealed that the miR-147b-3p mimic significantly enhanced cell viability, increased protein expressions of Alkaline Phosphatase (ALP) and Runt-related Transcription Factor 2 (RUNX2), and promoted mineralization as evidenced by Alizarin Red S staining. Conversely, treatment with the miR-147b-3p inhibitor or overexpression plasmid for NDUFA4 (pNDUFA4) produced opposite effects.Furthermore, the miR-147b-3p/NDUFA4 axis was found to regulate the PI3K/AKT signaling pathway.The miR-147b-3p mimic significantly increased the phosphorylation levels of PI3K (p-PI3K) and AKT (p-AKT), whereas pNDUFA4 led to their reduction.

CONCLUSIONS

This study demonstrated that miR-147b-3p plays a crucial role in promoting osteogenic differentiation in osteoporotic vertebral compression fractures (OVCF) by targeting NDUFA4 and modulating the PI3K/AKT signaling pathway. These findings provide new insights into the molecular mechanisms underlying the progression of osteoporotic vertebral fractures.

Mechanism of lncRNA ZFAS1 mediating nucleus pulposus cell pyroptosis in intervertebral disc degeneration

BACKGROUND

This study investigates the mechanism of lncRNA ZFAS1 in pyroptosis of TNF-α-induced nucleus pulposus cells (NPCs) in intervertebral disc degeneration (IDD).

METHODS

Mouse NPCs were isolated and induced by TNF-α to establish a cell model of IDD. The cell viability was evaluated by MTT assay. NLRP3, GSDMD-N, and cleaved-Caspase1 expressions were detected by Western blot. IL-1β and IL-18 contents were detected by ELISA. RT-qPCR was performed to determine ZFAS1, miR-155-3p, and METTL14 expressions. After intervening in ZFAS1 expression, the effect of ZFAS1 on pyroptosis was verified by Western blot and ELISA assays. RNA pull down or dual luciferase assay verified the binding between ZFAS1, miR-155-3p, and METTL14.

RESULTS

TNF-α induced pyroptosis of NPCs and promoted ZFAS1 expression. Silence of ZFAS1 repressed pyroptosis of TNF-α-induced NPCs. Mechanistically, ZFAS1 upregulated the transcription of METTL14 by competitively binding to miR-155-3p, thus enhancing NLRP3/Caspase-1-mediated NPC pyroptosis. Inhibition of miR-155-3p or overexpression of METTL14 alleviated the inhibitory effect of ZFAS1 silencing on TNF-α-treated NPC pyroptosis.

CONCLUSION

ZFAS1 facilitates NLRP3/Caspase-1-mediated pyroptosis of NPCs in IDD via miR-155-3p/METTL14 axis.

Involvement of icaritin in the regulation of osteocyte exosomal microRNAs

OBJECTIVE

To explore the effects of Icaritin (ICA) on the regulation of osteocyte exosomal miRNAs and to promote the understanding of the potential molecular mechanisms involved in bone repair by ICA.

METHODS

MLO-Y4 cells were treat with PBS or 10 µM ICA for 24 h and the supernatant was collected. Exosomes were isolated and purified according to standard methods, and identified by transmission electron microscopy, nanoparticle tracking analysis and protein blotting. Exosomal miRNAs were analysed by RNA sequencing.

RESULTS

Osteocyte exosomes were successfully isolated and characterised. MiRNA sequencing showed that two known exosomal miRNAs (miR-128-3p, miR-30a-5p) were significantly up-regulated and two were significantly down-regulated (miR-5112, miR-1285) after ICA intervention.

CONCLUSION

Based on the findings, ICA regulates several miRNAs of osteocytes, which deepen our understanding of the therapeutic effects and mechanisms of ICA on skeletal diseases.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Osteocytes are the most abundant cell type in bone tissue, of which the impact on bone homeostasis is still not clear. This study explored the impact of icaritin on osteocytes and their derived exosomes. By doing so, we hope to contribute to the understanding the therapeutic potential of ICA and osteocytes in maintaining bone health and treating conditions such as osteoporosis.

Unveiling new therapeutic horizons in rheumatoid arthritis: an In-depth exploration of circular RNAs derived from plasma exosomes

Rheumatoid arthritis (RA), a chronic inflammatory joint disease causing permanent disability, involves exosomes, nanosized mammalian extracellular particles. Circular RNA (circRNA) serves as a biomarker in RA blood samples. This research screened differentially expressed circRNAs in RA patient plasma exosomes for novel diagnostic biomarkers. In this study, samples of RA patients with insufficient response to methotrexate (MTX-IR), combined use of tumor necrosis factor inhibitors (TNFi) were followed up for half a year, and 56 circRNA samples of self-test data were stratified into training, testing, and external validation cohorts according to whether American College of Rheumatology 20% improvement criteria (ACR20) was achieved. A diagnostic xgboost model was developed using common hub genes identified by random forest and least absolute shrinkage and selection operator (LASSO), with intersection genes derived from overlapping machine learning-selected genes. Diagnostic performance evaluated via receiver operating characteristic (ROC) curves using pROC for area under the curve (AUC). Optimal LASSO model with 4 circRNAs determined, with AUC > 0.6 for key genes. The model validation performed well on the test set, but not significantly on the validation set. Then, circRNA screening was performed in combination with clinical data, and cross-validation identified hsa-circ0002715, hsa-circ0001946, hsa-circ0000836, and rheumatoid factor (RF) as key genes, among which hsa-circ0002715 and hsa-circ0001946 were emphasized as key markers on the training set. In addition, the morphology and size of exosomes and the expression of CD9 and CD81 verified the successful extraction of exosomes. The qPCR analysis of plasma exosomes in TNFi patients found that the expression of hsa-circ0002715 was higher than that in patients who didn't reach ACR20, and the expression of hsa-circ0001946 was lower than that in patients who didn't reach ACR20. The above studies suggested that hsa-circ0002715 and hsa-circ0001946 may become markers for predicting MTX-IR RA patients and TNFi precision treatment.

miR-208a-3p discriminates osteoporosis, predicts fracture, and regulates osteoclast activation through targeting STC1

BACKGROUND

Osteoporosis (OP) frequently occurs in post-menopausal women, increasing the risk of fracture. Early screening OP could improve the prevention of fractures.This study focused on the significance of miR-208a-3p in diagnosing OP and development regulation, aiming to explore a novel biomarker and therapeutic target for OP.

METHODS

The study enrolled a total of 154 post-menopausal women and grouping was performed based on the incidence of OP and fracture. The significance of miR-208a-3p was evaluated from the perspectives of menopausal correlation, OP diagnosis, and fracture prediction. In mechanism, the regulatory effect and mechanism of miR-208a-3p on osteoclast activation was investigated.

RESULTS

miR-208a-3p was menopause-related showing a negative correlation with E2 and positive correlations with FSH and LH. Significant upregulation of miR-208a-3p was observed in post-menopausal women with OP and showed significant diagnostic potential. Increasing miR-208a-3p was positively correlated with bone metabolism markers and negatively correlated with BMD of post-menopausal women with OP. Moreover, miR-208a-3p was also identified as a risk factor for fracture. STC1 was identified as a direct target of miR-208a-3p and was negatively regulated by miR-208a-3p. Silencing miR-208a-3p significantly alleviated macrophage inflammation and osteoblast activation, which was reversed by the knockdown of STC1.

CONCLUSION

Serum miR-208a-3p served as a diagnostic biomarker for OP and a risk factor for fracture in post-menopausal women. miR-208a-3p regulated macrophage inflammation and further mediated osteoclast activation via targeting STC1.

Autophagy activation alleviates annulus fibrosus degeneration via the miR-2355-5p/mTOR pathway

BACKGROUND

Intervertebral disc degeneration disease (IVDD) is a major cause of disability and reduced work productivity worldwide. Annulus fibrosus degeneration is a key contributor to IVDD, yet its mechanisms remain poorly understood. Autophagy, a vital process for cellular homeostasis, involves the lysosomal degradation of cytoplasmic proteins and organelles. This study aimed to investigate the role of autophagy in IVDD using a hydrogen peroxide (H2O2)-induced model of rat annulus fibrosus cells (AFCs).

METHODS

AFCs were exposed to H2O2 to model oxidative stress-induced degeneration. Protein expression levels of collagen I, collagen II, MMP3, and MMP13 were quantified. GEO database analysis identified alterations in miR-2355-5p expression, and its regulatory role on the mTOR pathway and autophagy was assessed. Statistical tests were used to evaluate changes in protein expression and pathway activation.

RESULTS

H2O2 exposure reduced collagen I and collagen II expression to approximately 50% of baseline levels, while MMP3 and MMP13 expression increased twofold. Activation of autophagy restored collagen I and II expression and decreased MMP3 and MMP13 levels. GEO analysis revealed significant alterations in miR-2355-5p expression, confirming its role in regulating the mTOR pathway and autophagy.

CONCLUSIONS

Autophagy, mediated by the miR-2355-5p/mTOR pathway, plays a protective role in AFCs degeneration. These findings suggest a potential therapeutic target for mitigating IVDD progression.

LINC00941 affects the proliferation, apoptosis and differentiation of osteoblasts by regulating the miR-335-5p/KAT7 axis

BACKGROUND

Fractures are the prevalent traumatic conditions encountered in orthopedic practices. The rising incidence of fractures has emerged as a pressing global health concern. Although the majority of individuals with fractures experience complete recovery of bone structure and function, approximately 10% of those with fractures exhibit delayed fracture healing (DFH). The objective of this investigation was to explore the function and underlying mechanisms of LINC00941 in the advancement of DFH, as well as its involvement in the regulation of osteoblastic differentiation by regulating the miR-335-5p/KAT7 axis.

METHODS

The expression levels of LINC00941, miR-335-5p, KAT7 and osteoblast differentiation-related markers were assessed using RT-qPCR. The proliferation of MC3T3-E1 cells was evaluated through the CCK-8 assay, and cell apoptosis was analyzed via flow cytometry. The targeted regulatory relationships between LINC00941 and miR-335-5p, as well as between miR-335-5p and KAT7 were verified by a dual-luciferase reporter gene assay.

RESULT

The expression of LINC00941 was significantly up regulated, while miR-335-5p exhibited a notable downregulation in DFH patients, both of LINC00941 and miR-335-5p have been identified as potential predicted markers for DFH. Furthermore, LINC00941 has been demonstrated to inhibit osteoblast proliferation, promote apoptosis, and suppress osteoblast differentiation through the regulation of the miR-335-5p/KAT7 axis.

CONCLUSION

LINC00941/ miR-335-5p/KAT7 axis may be a therapeutic target for DFH.

Circular RNAs in the management of human osteoporosis

BACKGROUND

Osteoporosis (OP) is a metabolic bone disease producing reduction in bone mass with consequent bone fragility. Circular ribonucleic acid (CircRNA) is a form of RNA that forms a loop structure rather than a linear one. CircRNA can be used for therapeutic purposes, including molecular targets or to test new therapies.

SOURCES OF DATA

A systematic search of different databases to July 2024 was performed to define the role of circRNA in OP therapy. Seventeen suitable studies were identified.

AREAS OF AGREEMENT

CircRNAs may be useful in studying metabolic processes in OP and identify possible therapeutic targets and new drug therapies.

AREAS OF CONTROVERSY

The metabolic processes involved in OP are regulated by many genes and cytokines that can be targeted by CircRNAs. However, it is not easy to predict whether the in vitro responses of the studied CircRNAs and their interaction with drugs are also applicable in vivo.

GROWING POINTS

Metabolic processes can be affected by gene dysregulation of CircRNAs on various growth factors. Areas timely for developing research: Despite the predictability of CircRNA pharmacological response in vitro, such pharmacological response cannot be expected to be replicated in vivo.

DATA AVAILABILITY

The data that support the findings of this study are available from the corresponding author.

LINC01271 promotes fracture healing via regulating miR-19a-3p/PIK3CA axis

OBJECTIVE

Osteoporosis increases the risk of fragility fractures, impacting patients' lives. This study aimed to investigate whether LINC01271 was involved in the process of fragility fractures and healing, providing a new perspective for its diagnosis and treatment.

METHODS

This study included 94 healthy individuals, 82 patients with osteoporosis, and 85 patients with fragility fractures as subjects. RT-qPCR was used to measure the levels of LINC01271, miR-19a-3p, PIK3CA, and osteogenic differentiation markers in osteoblasts and subjects' serum. Luciferase reporter assays, RIP experiments, and RNA pull-down assays were utilized to verify the target relationships between LINC01271 and miR-19a-3p, as well as between miR-19a-3p and PIK3CA. Cell proliferation and apoptosis were assessed using CCK-8 assays and flow cytometry.

RESULTS

Compared to the healthy control group, the serum levels of LINC01271 were significantly reduced in patients with osteoporosis and fragility fractures. Furthermore, LINC01271 levels increased with time-dependent fracture healing. In vitro studies indicated that LINC01271 boosted osteoblast proliferation, inhibited apoptosis, and augmented osteogenic differences, whereas its inhibition reverses their effects. LINC01271 and PIK3CA were identified as targets of miR-19a-3p, and overexpression of miR-19a-3p could antagonize the effect of LINC01271 in promoting fracture healing.

CONCLUSION

The results indicated that LINC01271 may play a key role in osteoblast function and fracture healing through its interaction with miR-19a-3p and regulation of PIK3CA.

circ_0075048 silencing regulates LCP1 to improve IL-1β-induced chondrocyte injury by binding with miR-663b

BACKGROUND

Osteoarthritis (OA) is a common type of degenerative arthropathy. Previous studies have demonstrated that circular RNAs (circRNAs) are involved in the progression of OA. This study aimed to investigate the role and associated mechanism of circ_0075048 in OA.

METHODS

The expression of circ_0075048 was analyzed based on the Gene Expression Omnibus dataset GSE178724. Human chondrocytes were stimulated with IL-1β to establish an in vitro OA model. Bioinformatic analysis was performed to identify target genes of circ_0075048. The expression of circ_0075048, miR-663b, and LCP1 was detected by quantitative reverse transcription-polymerase chain reaction. The cell viability and apoptosis of C28/I2 cells were determined using Cell Counting Kit-8 assay and flow cytometry. Protein expression was detected using western blotting.

RESULTS

The expression of circ_0075048 was up-regulated in IL-1β-induced chondrocytes. circ_0075048 silencing promoted the viability of and inhibited the apoptosis of and extracellular matrix (ECM) production of chondrocytes. circ_0075048 was found to be a sponge of miR-663b and LCP1 was found to be a target of miR-663b. circ_0075048 silencing increased miR-663b expression but decreased LCP1 expression levels in chondrocytes. An miR-663b inhibitor eliminated the protective effect of a circ_0075048 small interfering RNA (siRNA) on chondrocytes. However, an LCP1 siRNA abolished the effect of the miR-663b inhibitor on chondrocytes.

CONCLUSION

circ_0075048 silencing inhibited the apoptosis of and ECM degradation in IL-1β-induced chondrocytes by regulating miR-663b/LCP1 axis.

miR-468-3p suppresses osteogenic differentiation of BMSCs by targeting Runx2 and inhibits bone formation

An improved understanding of the molecular actions underpinning bone marrow mesenchymal stem cell (BMSC) differentiation could highlight new therapeutics for osteoporosis (OP). Current evidence indicates that microRNAs (miRNAs) exert critical roles in many biological systems, including osteoblast differentiation. In this study, we examined miR-468-3p effects on osteogenic differentiation (OD). Distinct miR-468-3p reductions were identified during OD. MiR-468-3p also suppressed BMSC OD in gain- and loss-of-function assays, while it negatively regulated Runx2 as shown by molecular, protein, and bioinformatics approaches. When Runx2 was inhibited by small-interfering RNA (siRNA), the inhibitory effects of miR-468-3p toward BMSC osteogenesis were considerably reversed. Also, silenced miR-468-3p in ovariectomized (OVX) and sham mice augmented bone mass (BM) and bone formation (BF) and improved trabecular (Tb) microarchitecture. Therefore, miR-468-3p is a novel Runx2 regulator with key physiological action in BF and OD.

CRNDE alleviates IL-1β-induced chondrocyte damage by modulating miR-31/NF-κB pathway

BACKGROUND

The long non-coding RNA CRNDE (CRNDE) has been identified as a lncRNA associated with osteoarthritis (OA), playing a role the age-related degeneration of articular cartilage. However, the precise mechanism by which CRNDE affects the physiological functions of OA chondrocytes remains unclear.

METHODS

To simulate the inflammatory conditions observed in OA, interleukin (IL)-1β-stimulated chondrocyte C-28/I2 cells were utilized. The expression levels of CRNDE and miR-31 were assessed using reverse transcription-polymerase chain reaction (RT-PCR). Chondrocyte viability and apoptosis were evaluated through CCK-8 assay and flow cytometry, respectively. The levels of IL-6, IL-1β and Tumor necrosis factor (TNF-α) were determined using enzyme-linked immunosorbent assay (ELISA). mRNA expression levels of MMP-13, Aggrecan and COL2A1 were detected by quantitative RT-PCR. Western blot analysis was performed to evaluate the protein levels of factors related to cartilage matrix degradation, including p-p65, p65 and p-IκBα of the NF-κB pathway.

RESULTS

CRNDE expression was downregulated in both OA cartilage tissues and IL-1β-stimulated chondrocytes. Overexpression of CRNDE mitigated IL-1β-stimulated chondrocytes apoptosis, inflammatory responses, and cartilage matrix degradation. Compared with healthy controls, OA tissues exhibited reduced expression of miR-31, which was negatively correlated with the expression of CRNDE. Additionally, overexpression of miR-31 partially reversed the inhibitory effects of CRNDE on apoptosis, inflammation, cartilage matrix degradation, and the inactivation of Nuclear factor (NF)-κB pathway induced by IL-1β stimulation. Moreover, silencing of CRNDE exacerbated IL-1β-induced chondrocytes damage, which was aliviated by the NF-κB pathway inhibitor, Bay 11-7082.

CONCLUSION

CRNDE alleviated IL-1β-induced injuries in OA chondrocytes by suppressing the miR-31-mediated NF-κB signaling pathway.

Functional mechanism and clinical implications of mir-1271-5p in pilon fracture healing processes

BACKGROUND

Pilon fractures are challenging to treat and carry a risk of delayed healing. MicroRNA (miRNA) is closely associated with various diseases due to its ability to regulate gene expression. Consequently, this study aimed to examine the connection between miR-1271-5p expression levels and pilon fracture healing processes, while also exploring the underlying mechanisms. The objective of this research was to provide valuable insights for the future clinical treatment of pilon fractures.

MATERIALS

Venous blood samples were obtained for RNA extraction from patients with normal healing (n = 107) or delayed healing (n = 45) of pilon fractures. The expression levels of miR-1271-5p were measured using qRT-PCR. MiR-1271-5p and ZBTB7A biological functions in MC3T3-E1 cells were examined using the Cell Counting Kit-8 (CCK-8), flow cytometry, and qRT-PCR. Finally, an investigation into the underlying mechanisms was carried out using a dual luciferase reporter assay.

RESULTS

This study found that, compared to those who healed normally, patients who experienced delayed healing of pilon fractures had significantly higher expression of miR-1271-5p. This suggests that miR-1271-5p may be an indicator for delayed healing in pilon fractures. Moreover, the upregulation of miR-1271-5p may result in a reduction of ZBTB7A expression, which is thought to mediate the effects of miR-1271-5p on MC3T3-E1 cell activities.

CONCLUSIONS

MiR-1271-5p was involved in the healing processes of pilon fractures via targeting ZBTB7A. MiR-1271-5p was a possible target for the therapy of pilon fractures.

lncRNA CASC11 regulates the progress of delayed fracture healing via sponging miR-150-3p

BACKGROUND

Long non-coding RNA (lncRNA) plays a pivotal role in bone regeneration by interaction with microRNAs (miRNAs) and constructing a lncRNA-miRNA regulatory network.

OBJECTIVES

This research aimed to elucidate the role of lncRNA CASC11 in the delayed healing process of tibial fractures and to explore its potential regulatory mechanisms.

MATERIALS AND METHODS

The expression levels of CASC11 and miR-150-3p in serum samples were detected and the predictive capability of CASC11 regarding delayed healing in fracture patients. Furthermore, the study confirmed the accuracy of the binding sites between CASC11 and miR-150-3p. Subsequently, overexpression/interference plasmids of CASC11, along with overexpression plasmids co-transfected with both CASC11 and miR-150-3p, were systematically introduced into MC3T3-E1 cells to investigate their effects on the expression of osteogenic marker genes, as well as their influence on cellular proliferation and apoptosis.

RESULTS

The expression levels of CASC11 were significantly elevated, while miR-150-3p levels were markedly decreased in individuals exhibiting delayed fracture healing (P < 0.001). CASC11 was observed to suppress the expression of osteogenic marker genes, inhibit the proliferation of MC3T3-E1 cells, and promote cell apoptosis (P < 0.05). Furthermore, the overexpression of miR-150-3p effectively countered the inhibitory impact of CASC11 on osteogenic differentiation and the promoting effect on cell apoptosis (P < 0.05).

CONCLUSION

The sponging effect of CASC11 on miR-150-3p led to delayed fracture healing. CASC11 emerges as a potential target for treating delayed fracture healing.

MiR203a-3p as a potential biomarker for synovial pathology associated with osteoarthritis: a pilot study

BACKGROUND

Osteoarthritis (OA) is a degenerative musculoskeletal disease that significantly impacts the quality of life. Currently, no validated biomarkers for early detection of OA are defined. The possibility of discovering OA biomarkers is the focus of this study.

METHODS

Human primary OA synovial cells (SVs), isolated from discarded joint tissue of patients with Kellgren & Lawrence score (KL) < 3, (mild/moderate) and KL ≥ 3 (severe), were characterized by FACS analysis. Through qRT-PCR and ELISA assays the inflammation, fibrosis status and the different miRNAs expression has been investigated. The role of miR-203a-3p and its precursors were evaluated through gain and loss of function study, IL-1β synoviocytes treatments and methylation analysis of miR203a promoter. The qRT-PCR analysis of miR203a-3p and pre-miR203a on plasma (isolated 24 h before surgery, 3 days and 1 month after surgery) and synovial fluid (recovered during the surgery) were done to support our in vitro data.

RESULTS

MiR203a-3p expression is inversely correlated with the aggressiveness of OA, modulating the expression of epithelial to mesenchymal transition (EMT) and pro-inflammatory factors, as well as regulating the expression of secreted protein acidic and rich in cysteine (SPARC) mRNA. Methylation analysis of the miR203a promoter and SVs IL-1β treatment's highlighted the impact of inflammation on miR203a-3p and pre-miR203a expression; as confirmed by both miRNAs detection in biological fluids derived from patients with severe OA.

CONCLUSION

Our preliminary results suggest that miR-203a-3p might be a potential candidate for staging OA progression and a new protective/predictive biomarker for synovial OA degeneration. Further studies are needed to validate its potential impact on OA.

CRISPR activation identifies a novel miR-2861 binding site that facilitates the osteogenesis of human mesenchymal stem cells

We investigated the regulation of histone deacetylases (HDACs) by miR-2861 in the osteoblastic differentiation of human mesenchymal stem cells (MSCs) and miR-2861 binding site by CRISPR activation (CRISPRa). Transfection of miR-2861 into human MSCs was performed and the effect on osteoblast differentiation was analyzed. Using catalytically inactive Cas12a, the CRISPRa system induced targeted overexpression of endogenous miRNA and repressed the luciferase activities of reporters that contained functional miRNA target sites. The delivery of miR-2861 into MSCs enhanced osteoblast differentiation by decreased expressions of the HDAC1, 4 and 5 genes. The mechanism of HDAC5 repression by miR-2861 in humans has not been fully elucidated. To this end, the HDAC5 mRNA sequence was analyzed and a putative primate-specific miR-2861 binding site was identified in the 3' untranslated region (3'-UTR). CRISPRa was applied to validate the putative binding site and an increase in endogenous miR-2861 was found to repress the expression of a reporter that contained the novel miR-2861 binding site. The delivery of miR-2861 to human MSCs enhanced osteoblast differentiation. In the 3'-UTR, the HDAC5 repression was mediated by the miR-2861 binding site, and miR-2861 promoted osteoblast differentiation via the inhibition of HDAC5 through a primate-specific miRNA binding site. Therefore, miRNAmiR-2861 with the CRISPRa methods might be a good biomaterial for osteogenesis augmentation.

METTL3 accelerates staphylococcal protein A (SpA)-induced osteomyelitis progression by regulating m6A methylation-modified miR-320a

Osteomyelitis (OM) is an inflammatory disease of bone infection and destruction characterized by dysregulation of bone homeostasis. Staphylococcus aureus (SA) has been reported to be the most common pathogen causing infectious OM. Recent studies have demonstrated that N6-methyladenosine (m6A) regulators are associated with the development of OM. However, the molecular mechanism of m6A modifications in OM remains unclear. Here, we investigated the function of methyltransferase-like 3 (METTL3)-mediated m6A modification in OM development. In this study, human bone mesenchymal stem cells (hBMSCs) were treated with staphylococcal protein A (SpA), a vital virulence factor of SA, to construct cell models of OM. Firstly, we found that METTL3 was upregulated in OM patients and SpA-induced hBMSCs, and SpA treatment suppressed osteogenic differentiation and induced oxidative stress and inflammatory injury in hBMSCs. Functional experiments showed that METTL3 knockdown alleviated the inhibition of osteogenic differentiation and the promotion of oxidative stress and inflammation in SpA-treated hBMSCs. Furthermore, METTL3-mediated m6A modification upregulated miR-320a expression by promoting pri-miR-320a maturation, and the mitigating effects of METTL3 knockdown on SpA-mediated osteogenic differentiation, oxidative stress and inflammatory responses can be reversed by miR-320 mimic. In addition, we demonstrated that phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) was a downstream target of miR-320a, upregulation of PIK3CA alleviated miR-320a-induced inhibition of osteogenic differentiation, and upregulation of oxidative stress and inflammatory responses during SpA infection. Finally, we found that silencing METTL3 alleviated OM development by regulating the miR-320a/PIK3CA axis. Taken together, our data demonstrated that the METTL3/m6A/miR-320a/PIK3CA axis regulated SpA-mediated osteogenic differentiation, oxidative stress, and inflammatory responses in OM, which may provide a new therapeutic strategy for OM patients.

The role of lncRNA TSIX in osteoarthritis pathogenesis: mechanistic insights and clinical biomarker potential

BACKGROUND

This study seeks to elucidate the expressions of lncRNA TSIX in Osteoarthritis (OA) and to explore its mechanisms in regulating OA progression.

METHODS

RT-qPCR was employed to analyze the expression of TSIX in OA patients classified by Kellgren-Lawrence (K-L) grades. Receiver operator characteristic (ROC) was conducted to evaluate the diagnostic value of TSIX. Correlation between TSIX levels and clinical scores such as Lysholm and visual analogue scale (VAS) score was evaluated using Pearson method. IL-1β-induced SW1353 cells served as an in vitro model. The cell function were assessed by flow cytometry and cell counting kit-8 (CCK-8) assay. The relationship between TSIX and miR-320a was verified by luciferase reporting system, while bioinformatics approaches were utilized to predict the downstream target genes of miR-320a.

RESULTS

The findings revealed that TSIX level in OA patients was elevated compared to that of the control group, with a notable progressive increase in TSIX expression correlated with higher K-L grades. In OA patients, the Lysholm score showed a negative correlation with TSIX expression, while the VAS score displayed a positive correlation with TSIX levels. Cell studies demonstrated that inhibition of TSIX enhanced cell viability and mitigated IL-1β-induced apoptosis by targeting miR-320a, in addition to promoting Aggrecan and Collagen II secretion. Luciferase reporter assay further validated the targeting interaction among TSIX, miR-320a, and PTEN.

CONCLUSIONS

This study demonstrated an increased expression of TSIX in OA patients. It suggests that TSIX may play a role in chondrocyte dysfunction during OA by modulating the miR-320a/PTEN axis.

Identification of circRNA CDR1as/miR-214-3p regulatory axis in Legg-Calvé-Perthes disease

BACKGROUND

Legg-Calvé-Perthes disease (LCPD) commonly occurs among adolescents, threatening their health. However, the potential mechanism underlying LCPD remains unclear. miR-214-3p is shown as a critical role in LCPD development with unspecified upstream regulators.

METHODS

Levels of miR-214-3p and circCDR1as in healthy controls and LCPD patients were determined by qRT-PCR. The role of circCDR1as/miR-214-3p axis in LCPD was determined by testing the cell viability and apoptosis in TC28 cells and primary chondrocytes. Regulation between circCDR1as and miR-214-3p was examined by RIP and ChIP assays. The inflammatory response and angiogenesis were evaluated by M2 macrophage polarization and HUVECs tumor formation.

RESULTS

circCDR1as was overexpressed in LCPD patients with a negative correlation with miR-214-3p. Inhibition of circCDR1as alleviated the cell viability and apoptosis of DEX-treated chondrocytes, stimulated M2 macrophage polarization and angiogenesis. miR-214-3p was proved as a downstream effector to participate in circCDR1as mediated actions. circCDR1as recruited PRC2 complex to epigenetically suppress miR-214-3p.

CONCLUSION

Our study illustrated the role and mechanism of circCDR1as in LCPD development by targeting miR-214-3p, highlighting its potential in the therapy for LCPD.

Low shear stress protects chondrocytes from IL-1β-induced apoptosis by activating ERK5/KLF4 signaling and negatively regulating miR-143-3p

OBJECTIVE

This study investigated the protective effects of low fluid shear stress (FSS ≤ 2 dyn/cm²) against interleukin-1β (IL-1β)-induced chondrocyte apoptosis and explored the underlying molecular mechanisms.

METHODS

Chondrocytes were cultured under four conditions: control, IL-1β stimulation, low FSS, and combined low FSS + IL-1β stimulation. Apoptosis was assessed using Hoechst staining and flow cytometry. Western blotting determined the expression of caspase-3 (CASP3), caspase-8 (CASP8), and NF-κB p65. Quantitative real-time PCR measured miR-143-3p expression. The roles of miR-143-3p and the extracellular signal-regulated kinase 5 (ERK5)/Krüppel-like factor 4 (KLF4) signaling pathway were further investigated using miR-143-3p mimics and inhibitors, an ERK5 inhibitor, and a KLF4 overexpression vector.

RESULTS

IL-1β induced significant chondrocyte apoptosis, which was markedly inhibited by low FSS. Mechanistically, low FSS suppressed miR-143-3p expression, thereby enhancing ERK5 signaling. This activated ERK5 subsequently upregulated KLF4 expression, further mitigating IL-1β-induced damage. Importantly, miR-143-3p overexpression under low FSS conditions exacerbated IL-1β-induced apoptosis, while miR-143-3p inhibition attenuated it. Consistent with this, ERK5 inhibition augmented IL-1β-induced apoptosis, whereas KLF4 overexpression suppressed it.

CONCLUSION

Low FSS protects chondrocytes from IL-1β-induced apoptosis by suppressing miR-143-3p and activating the ERK5/KLF4 signaling pathway. This study reveals a novel mechanism by which mechanical stimulation protects cartilage.

Shuanglongjiegu pill promoted bone marrow mesenchymal stem cell osteogenic differentiation by regulating the miR-217/RUNX2 axis to activate Wnt/β-catenin pathway

This study aimed to investigate the effects of Shuanglongjiegu pill (SLJGP) on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and explore its mechanism based on miR-217/RUNX2 axis. Results found that drug-containing serum of SLJGP promoted BMSCs viability with a dose-dependent effect. Under osteogenic differentiation conditions, SLJGP promoted the expression of ALP, OPN, BMP2, RUNX2, and the osteogenic differentiation ability of BMSCs. In addition, SLJGP significantly reduced miR-217 expression, and miR-217 directly targeted RUNX2. After treatment with miR-217 mimic, the promoting effects of SLJGP on proliferation and osteogenic differentiation of BMSCs were significantly inhibited. MiR-217 mimic co-treated with pcDNA-RUNX2 further confirmed that the miR-217/RUNX2 axis was involved in SLJGP to promote osteogenic differentiation of BMSCs. In addition, analysis of Wnt/β-catenin pathway protein expression showed that SLJGP activated the Wnt/β-catenin pathway through miR-217/RUNX2. In conclusion, SLJGP promoted osteogenic differentiation of BMSCs by regulating miR-217/RUNX2 axis and activating Wnt/β-catenin pathway.

LINC01133 promotes the osteogenic differentiation of bone marrow mesenchymal stem cells by upregulating CTNNB1 by acting as a sponge for miR-214-3p

BACKGROUND

Osteoporosis results from decreased bone mass and disturbed bone structure. Human bone marrow mesenchymal stem cells (hBMSCs) demonstrate robust osteogenic differentiation, a critical process for bone formation. This research was designed to examine the functions of LINC01133 in osteogenic differentiation.

METHODS

Differentially expressed lncRNAs affecting osteogenic differentiation in hBMSCs were identified from the GEO database. A total of 74 osteoporosis patients and 70 controls were enrolled. hBMSCs were stimulated to undergo osteogenic differentiation using an osteogenic differentiation medium (OM). RT-qPCR was performed to evaluate LINC01133 levels and osteogenesis-related genes such as osteocalcin, osteopontin, and RUNX2. An alkaline phosphates (ALP) activity assay was conducted to assess osteogenic differentiation. Cell apoptosis was detected using flow cytometry. Dual luciferase reporter assay and RIP assay were employed to investigate the association between miR-214-3p and LINC01133 or CTNNB1. Loss or gain of function assays were conducted to elucidate the impact of LINC01133 and miR-214-3p on osteogenic differentiation of hBMSCs.

RESULTS

LINC01133 and CTNNB1 expression decreased in osteoporotic patients but increased in OM-cultured hBMSCs, whereas miR-214-3p showed an opposite trend. Depletion of LINC01133 suppressed the expression of genes associated with bone formation and ALP activity triggered by OM in hBMSCs, leading to increased cell apoptosis. Nevertheless, this suppression was partially counteracted by the reduced miR-214-3p levels. Mechanistically, LINC01133 and CTNNB1 were identified as direct targets of miR-214-3p.

CONCLUSIONS

Our study highlights the role of LINC01133 in positively regulating CTNNB1 expression by inhibiting miR-214-3p, thereby promoting osteogenic differentiation of BMSCs. These findings may provide valuable insights into bone regeneration in osteoporosis.

Analysis of the predictive value of microRNA-199b-5p combined with nitric oxide for venous thrombosis in patients undergoing total knee arthroplasty

BACKGROUND

Deep vein thrombosis (DVT) of lower extremity is a common complications after total knee arthroplasty (TKA). The purpose of this study was to evaluate the risk factors for DVT after TKA and analyze the expression of miR-199b-5p and nitric oxide (NO) before and after TKA, as well as their predictive value for DVT.

METHODS

Basic clinical information of 121 patients with TKA was analyzed retrospectively. RT-qPCR was used to detect the relative expression level of miR-199b-5p in patients before and after TKA treatment. Based on the occurrence of DVT, patients were divided into DVT and non-DVT groups. Logistic regression analysis evaluated the risk factors of DVT. The receiver operating characteristic (ROC) curve assessed the predictive value of postoperative miR-199b-5p level, preoperative NO level, and their combination in DVT. The target genes of miR-199b-5p and their functions were predicted and annotated using bioinformatics analysis.

RESULTS

The level of miR-199b-5p after TKA was upregulated compared with that before TKA (P < 0.001). DVT occurred in 20 of 121 patients after TKA, with an incidence of 16.53%. Multivariate analysis showed that age, family history of DVT, decrease of NO and increase of miR-199b-5p were risk factors for DVT after TKA (P < 0.05). The ROC curve showed that both miR-199b-5p and NO had certain diagnostic value for DVT, but the combination of miR-199b-5p and NO had the highest diagnostic accuracy (P < 0.001).

CONCLUSION

This study showed that the expression of miR-199b-5p was up-regulated after TKA, and miR-199b-5p levels were higher in DVT patients than in non-DVT patients. miR-199b-5p combined with NO is of great value in the diagnosis of DVT after TKA.

MiR-331-3p facilitates osteoporosis and may promote osteoporotic fractures by modulating NRP2 expression

BACKGROUND

Osteoporosis (OP) is a high-incidence bone disease that is prone to osteoporotic fractures (OF), so it has attracted widespread attention.

AIM

This study investigated the specific expression and role of miR-331 in patients with OP and OF. The findings have profound implications for the clinical prevention and treatment of these conditions.

METHODS

The study included 60 OP patients, 46 OF patients, and 40 healthy controls. The expression level of miR-331-3p was detected using RT-qPCR. BMP2 was used to stimulate differentiation in MC3T3-E1 cells. After induction, the expression activity of osteogenic differentiation-related gene markers was detected using RT-qPCR. The target gene analysis was conducted using a luciferase reporter assay.

RESULTS

The levels of miR-331-3p were significantly elevated, while NRP2 levels were significantly reduced in OF patients. Post-surgery, miR-331-3p levels decreased over time. MiR-331-3p was found to negatively regulate the luciferase activity of NPR2 in MC3T3-E1 cells. Furthermore, overexpression of miR-331-3p inhibited cell proliferation and decreased the levels of osteoblast differentiation markers.

CONCLUSION

The up-regulation of miR-331-3p can promote OP and might also encourage the occurrence of OF by regulating NRP2. However, this needs further verification.

mir-744-5p inhibits cell growth and angiogenesis in osteosarcoma by targeting NFIX

BACKGROUND

Osteosarcoma (OS) is a malignant bone tumor that commonly occurs in children and adolescents under the age of 20. Dysregulation of microRNAs (miRNAs) is an important factor in the occurrence and progression of OS. MicroRNA miR-744-5p is aberrantly expressed in various tumors. However, its roles and molecular targets in OS remain unclear.

METHODS

Differentially expressed miRNAs in OS were analyzed using the Gene Expression Omnibus dataset GSE65071, and the potential hub miRNA was identified through weighted gene co-expression network analysis. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-744-5p in OS cell lines. In vitro experiments, including CCK-8 assays, colony formation assays, flow cytometry apoptosis assays, and tube formation assays, were performed to explore the effects of miR-744-5p on OS cell biological behaviors. The downstream target genes of miR-744-5p were predicted through bioinformatics, and the binding sites were validated by a dual-luciferase reporter assay.

RESULTS

The lowly expressed miRNA, miR-744-5p, was identified as a hub miRNA involved in OS progression through bioinformatic analysis. Nuclear factor I X (NFIX) was confirmed as a direct target for miR-744-5p in OS. In vitro studies revealed that overexpression of miR-744-5p could restrain the growth of OS cells, whereas miR-744-5p inhibition showed the opposite effect. It was also observed that treatment with the conditioned medium from miR-744-5p-overexpressed OS cells led to poorer proliferation and angiogenesis in human umbilical vein endothelial cells (HUVECs). Furthermore, NFIX overexpression restored the suppression effects of miR-744-5p overexpression on OS cell growth and HUVECs angiogenesis.

CONCLUSION

Our results indicated that miR-744-5p is a potential tumor-suppressive miRNA in OS progression by targeting NFIX to restrain the growth of OS cells and angiogenesis in HUVECs.

Long non-coding TRPM2-AS regulates fracture healing by targeting miR-545-3p/Bmp2

OBJECTIVE

Delayed fracture healing increases the suffering of patients. An in-depth investigation of the pathogenesis of delayed fracture healing may offer new direction for the prevention and treatment.

METHODS

The study included 63 normal healing tibial fractures and 58 delayed healing tibial fractures patients. Long non-coding RNA (lncRNA)TRPM2-AS, microRNA-545-3p (miR-545-3p), bone morphogenetic protein 2 (Bmp2) mRNA and osteogenic differentiation markers, including runt-related transcription factor 2 (Runx2), osteocalcin (Ocn), and alkaline phosphatase (Alp) mRNA expression were determined by Real-time quantitative reverse transcription-polymerase chain reaction in serum and MC3T3-E1 cells. The prediction potential of TRPM2-AS in delayed healing fracture patients was verified by receiver operating characteristic curves. The binding relationship of TRPM2-AS/miR-545-3p/Bmp2 was evaluated by dual luciferase reporter gene assay. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry.

RESULTS

TRPM2-AS was remarkably down-regulated in patients with delayed fracture healing and could better predict the fracture healing status. TRPM2-AS downregulation inhibited osteogenic markers mRNA expression, restrained proliferation, and promoted apoptosis of MC3T3-E1 cells (p < 0.05). In delayed fracture healing, miR-545-3p was dramatically up-regulated and was negatively regulated by TRPM2-AS. Reducing miR-545-3p eliminate the negative effect of TRPM2-AS down-regulation on osteoblast proliferation and differentiation (p < 0.05). miR-545-3p targets Bmp2, which plays a positive role in osteoblast differentiation (p < 0.05).

CONCLUSION

This study found that TRPM2-AS has the potential to be a diagnostic marker for delayed fracture healing and revealed that the TRPM2-AS/miR-545-3p/Bmp2 axis affects fracture healing by regulating osteoblast.

SP1 regulates BMSC osteogenic differentiation through the miR-133a-3p/MAPK3 axis : SP1 regulates osteogenic differentiation of BMSCs

BACKGROUND

The progression of osteoporosis (OP) can dramatically increase the risk of fractures, which seriously disturb the life of elderly individuals. Specific protein 1 (SP1) is involved in OP progression. However, the mechanism by which SP1 regulates OP progression remains unclear.

OBJECTIVE

This study investigated the mechanism underlying the function of SP1 in OP.

METHODS

SAMP6 mice were used to establish an in vivo model of age-dependent OP, and BALB/c mice were used as controls. BMSCs were extracted from two subtypes of mice. Hematoxylin and eosin staining were performed to mark the intramedullary trabecular bone structure to evaluate histological changes. ChIP assay was used to assess the targeted regulation between SP1 and miR-133a-3p. The binding sites between MAPK3 and miR-133a-3p were verified using a dual-luciferase reporter assay. The mRNA levels of miR-133a-3p and MAPK3 were detected using quantitative reverse transcription polymerase chain reaction (RT-qPCR). The protein expression of SP1, MAPK3, Colla1, OCN, and Runx2 was examined using Western blotting. Alkaline phosphatase (ALP) kit and Alizarin Red S staining were used to investigate ALP activity and mineralized nodules, respectively.

RESULTS

The levels of SP1 and miR-133a-3p were upregulated, whereas the expression of MAPK3 was downregulated in BMSCs from SAMP6 mice, and miR-133a-3p inhibitor accelerated osteogenic differentiation in BMSCs. SP1 directly targeted miR-133a-3p, and MAPK3 was the downstream mRNA of miR-133a-3p. Mechanically, SP1 accelerated osteogenic differentiation in BMSCs via transcriptional mediation of the miR-133a-3p/MAPK3 axis.

CONCLUSION

SP1 regulates osteogenic differentiation by mediating the miR-133a-3p/MAPK3 axis, which would shed new light on strategies for treating senile OP.

LncRNA MAGI2-AS3 promotes fracture healing through downregulation of miR-223-3p

BACKGROUND

Long non-coding RNAs (LncRNAs) are recognized as a pivotal element in the processes of fracture healing and the osteogenic differentiation of stem cells. This study investigated the molecular mechanism and regulatory significance of lncRNA MAGI2-AS3 (MAGI2-AS3) in fracture healing.

METHODS

Serum levels of MAGI2-AS3 in patients with normal and delayed fracture healing were verified by RT-qPCR assays. The predictive efficacy of MAGI2-AS3 for delayed fracture healing was analyzed by ROC curve. Osteogenic markers were quantified by RT-qPCR assays. MC3T3-E1 cell viability was detected using CCK-8 assay, and flow cytometry was utilized to measure cell apoptosis. The dual-luciferase reporter gene assay was used to determine the targeted binding between MAGI2-AS3 and miR-223-3p.

RESULTS

Serum MAGI2-AS3 expression was decreased in patients with delayed fracture healing compared with patients with normal healing. Elevated MAGI2-AS3 resulted in an upregulation of the proliferative capacity of MC3T3-E1 cells and a decrease in mortality, along with increased levels of both osteogenic markers. However, after transfection silencing MAGI2-AS3, the trend was reversed. Additionally, miR-223-3p was the downstream target of MAGI2-AS3 and was controlled by MAGI2-AS3. miR-223-3p mimic reversed the promoting effects of MAGI2-AS3 overexpression on osteogenic marker levels and cell growth, and induced cell apoptosis.

CONCLUSION

The upregulation of MAGI2-AS3 may expedite the healing of fracture patients by targeting miR-223-3p, offering a novel biomarker for diagnosing patients with delayed healing.

Long non-coding RNA MIAT serves as a biomarker of fragility fracture and promotes fracture healing

BACKGROUND

Fragility fracture is common in the elderly. Osteoblast differentiation is essential for bone healing and regeneration. Expression pattern of long non-coding RNA MIAT during fracture healing was examined, and its role in osteoblast differentiation was investigated.

METHODS

90 women with simple osteoporosis and 90 women with fragility fractures were included. Another 90 age-matched women were set as the control group. mRNA levels were tested using RT-qPCR. Cell viability was detected via CCK-8, and osteoblastic biomarkers, including ALP, OCN, Collagen I, and RUNX2 were tested via ELISA. The downstream miRNAs and genes targeted by MIAT were predicted by bioinformatics analysis, whose functions and pathways were annotated via GO and KEGG analysis.

RESULTS

Serum MIAT was upregulated in osteoporosis women with high accuracy of diagnostic efficacy. Serum MIAT was even elevated in the fragility fracture group, but decreased in a time manner after operation. MIAT knockdown promoted osteogenic proliferation and differentiation of MC3T3-E1, but the influences were reversed by miR-181a-5p inhibitor. A total of 137 overlapping target genes of miR-181a-5p were predicted based on the miRDB, TargetScan and microT datasets, which were mainly enriched for terms related to signaling pathways regulating pluripotency of stem cells, cellular senescence, and osteoclast differentiation.

CONCLUSIONS

LncRNA MIAT serves as a promising biomarker for osteoporosis, and promotes osteogenic differentiation via targeting miR-181a-5p.

miR-27b-3p reduces muscle fibrosis during chronic skeletal muscle injury by targeting TGF-βR1/Smad pathway

BACKGROUND

Fibrosis is a significant pathological feature of chronic skeletal muscle injury, profoundly affecting muscle regeneration. Fibro-adipogenic progenitors (FAPs) have the ability to differentiate into myofibroblasts, acting as a primary source of extracellular matrix (ECM). the process by which FAPs differentiate into myofibroblasts during chronic skeletal muscle injury remains inadequately explored.

METHOD

mouse model with sciatic nerve denervated was constructed and miRNA expression profiles between the mouse model and uninjured mouse were analyzed. qRT/PCR and immunofluorescence elucidated the effect of miR-27b-3p on fibrosis in vivo and in vitro. Dual-luciferase reporter identified the target gene of miR-27b-3p, and finally knocked down or overexpressed the target gene and phosphorylation inhibition of Smad verified the influence of downstream molecules on the abundance of miR-27b-3p and fibrogenic differentiation of FAPs.

RESULT

FAPs derived from a mouse model with sciatic nerves denervated exhibited a progressively worsening fibrotic phenotype over time. Introducing agomiR-27b-3p effectively suppressed fibrosis both in vitro and in vivo. MiR-27b-3p targeted Transforming Growth Factor Beta Receptor 1 (TGF-βR1) and the abundance of miR-27b-3p was negatively regulated by TGF-βR1/Smad.

CONCLUSION

miR-27b-3p targeting the TGF-βR1/Smad pathway is a novel mechanism for regulating fibrogenic differentiation of FAPs. Increasing abundance of miR-27b-3p, suppressing expression of TGF-βR1 and inhibiting phosphorylation of smad3 presented potential strategies for treating fibrosis in chronic skeletal muscle injury.

Upregulation of circ_0076684 in osteosarcoma facilitates malignant processes by mediating miRNAs/CUX1

Circular RNAs (circRNAs) are a newly appreciated type of endogenous noncoding RNAs that play vital roles in the development of various human cancers, including osteosarcoma (OS). In this study, we investigated three circRNAs (circ_0076684, circ_0003563, circ_0076691) from the RUNX Family Transcription Factor 2 (RUNX2) gene locus in OS. We found that the expression of circ_0076684, circ_0003563, circ_0076691, and RUNX2 mRNA is upregulated in OS, which is a consequence of CBX4-mediated transcriptional activation. Among these three RUNX2-circRNAs, only circ_0076684 is significantly associated with the clinical features and prognosis of OS patients. Functional experiments indicate that circ_0076684 promotes OS progression in vitro and in vivo. Circ_0076684 acts as a sponge for miR-370-3p, miR-140-3p, and miR-193a-5p, raising Cut Like Homeobox 1 (CUX1) expression by sponging these three miRNAs. Furthermore, we presented that circ_0076684 facilitates OS progression via CUX1. In conclusion, this study found that the expression of three circRNAs and RUNX2 mRNA from the RUNX2 gene locus is significantly upregulated in OS, as a result of CBX4-mediated transcriptional activation. Circ_0076684 raises CUX1 expression by sponging miR-370-3p, miR-140-3p, and miR-193a-5p, and facilitates OS progression via CUX1.

Circ_0044235 regulates the development of osteoarthritis by the modulation of miR-375/PIK3R3 axis

BACKGROUND

Circular RNAs (circRNAs) play an important role in osteoarthritis (OA). However, the role of circRNA in OA is still unclear. Here, we explored the role and mechanism of circ_0044235 in OA.

METHODS

CHON-001 cells were treated with IL-1β to establish OA model in vitro. The levels of circ_0044235, miR-375 and phosphoinositide 3-kinase (PI3K) regulatory subunit 3 (PIK3R3) were detected by quantitative real-time PCR. Cell count kit-8 assay and flow cytometry assay were used to detect cell viability and apoptosis. The concentrations of inflammation factors were determined by enzyme-linked immunosorbent assay. Western blot was used to detect protein levels. The interaction between miR-375 and circ_0044235 or PIK3R3 was analyzed by dual-luciferase reporter assay and RNA immunoprecipitation assay.

RESULTS

Circ_0044235 was significantly decreased in OA cartilage tissue and IL-1β-treated CHON-001 cells. Overexpression of circ_0044235 promoted IL-1β-stimulated CHON-001 cell viability and inhibited apoptosis, inflammation, and extracellular matrix (ECM) degradation. In mechanism analysis, circ_0044235 could act as a sponge for miR-375 and positively regulate PIK3R3 expression. In addition, miR-375 ameliorated the effect of circ_0044235 overexpression on IL-1β-mediated CHON-001 cells injury. In addition, miR-375 inhibition mitigated IL-1β-induced CHON-001 cell injury, while PIK3R3 silencing restored the effect.

CONCLUSION

Circ_0044235 knockdown alleviated IL-1β-induced chondrocytes injury by regulating miR-375/PIK3R3 axis, confirming that circ_0044235 might be a potential target for OA treatment.

Perimenopause in women with rheumatologic diseases: a spotlight on an under-addressed transition

Abundant research has been published describing the effects invoked during menopause across different organ systems. Changing levels of estrogen and progesterone result in bidirectional alterations of immune cell pathways. Overall, the net trend dampens immunoregulation and promotes inflammation. In paradigmatic rheumatologic diseases, the combined effect is far from predictable. While some features may abate during menopause, studies have shown a general increased frequency toward disease exacerbation. Similarly, while impossible to isolate the ramifications of menopause in women with fibromyalgia, a tendency toward enhanced symptoms is unquestionably apparent. Furthermore, the comorbidities accrued by increasing age and the consequences of long-term medication use may also confound this picture. Periodic rheumatologic visits are warranted, with clinical assessments directed toward a multi-disciplinary approach. Ultimately, while an arsenal of effective tools is available for caring for these women and their underlying conditions, more studies are needed to better clarify how the different stages surrounding perimenopause affect subpopulations with rheumatic diseases and fibromyalgia-related disorders so that clinical course can be predicted and addressed prior to the emergence of symptomatology.

Saikosaponin D alleviates inflammatory response of osteoarthritis and mediates autophagy via elevating microRNA-199-3p to target transcription Factor-4

OBJECTIVE

This study was to investigate the underlying mechanism by which Saikosaponin D (SSD) mitigates the inflammatory response associated with osteoarthritis (OA) and regulates autophagy through upregulation of microRNA (miR)-199-3p and downregulation of transcription Factor-4 (TCF4).

METHODS

A mouse OA model was established. Mice were intragastrically administered with SSD (0, 5, 10 μmol/L) or injected with miR-199-3p antagomir into the knee. Then, pathological changes in cartilage tissues were observed. Normal chondrocytes and OA chondrocytes were isolated and identified. Chondrocytes were treated with SSD and/or transfected with oligonucleotides or plasmid vectors targeting miR-199-3p and TCF4. Cell viability, apoptosis, inflammation, and autophagy were assessed. miR-199-3p and TCF4 expressions were measured, and their targeting relationship was analyzed.

RESULTS

In in vivo experiments, SSD ameliorated cartilage histopathological damage, decreased inflammatory factor content and promoted autophagy in OA mice. miR-199-3p expression was downregulated and TCF4 expression was upregulated in cartilage tissues of OA mice. miR-199-3p expression was upregulated and TCF4 expression was downregulated after SSD treatment. Downregulation of miR-199-3p attenuated the effect of SSD on OA mice. In in vitro experiments, SSD inhibited the inflammatory response and promoted autophagy in OA chondrocytes. Downregulation of miR-199-3p attenuated the effect of SSD on OA chondrocytes. In addition, upregulation of miR-199-3p alone inhibited inflammatory responses and promoted autophagy in OA chondrocytes. miR-199-3p targeted TCF4. Upregulation of TCF4 attenuated the effects of miR-199-3p upregulation on OA chondrocytes.

CONCLUSIONS

SSD alleviates inflammatory response and mediates autophagy in OA via elevating miR-199-3p to target TCF4.

MicroRNA-877-5p promotes osteoblast differentiation by targeting EIF4G2 expression

Stimulating bone formation potentially suggests therapeutics for orthopedic diseases including osteoporosis and osteoarthritis. Osteoblasts are key to bone remodeling because they act as the only bone-forming cells. miR-877-5p has a chondrocyte-improving function in osteoarthritis, but its effect on osteoblast differentiation is unknown. Here, miR-877-5p-mediated osteoblast differentiation was studied. Real-time reverse transcriptase-polymerase chain reaction was performed to measure miR-877-5p expression during the osteogenic differentiation of MC3T3-E1 cells. Osteoblast markers, including alkaline phosphatase (ALP), collagen type I a1 chain, and osteopontin, were measured and detected by alizarin red staining and ALP staining. Potential targets of miR-877-5p were predicted from three different algorithms: starBase ( http://starbase.sysu.edu.cn/ ), PITA ( http://genie.weizmann.ac.il/pubs/mir07/mir07_data.html ), and miRanda ( http://www.microrna.org/microrna/home.do ). It was further verified by dual luciferase reporter gene assay. The experimental results found that miR-877-5p was upregulated during the osteogenic differentiation of MC3T3-E1 cells. Overexpression of miR-877-5p promoted osteogenic differentiation, which was characterized by increased cell mineralization, ALP activity, and osteogenesis-related gene expression. Knockdown of miR-877-5p produced the opposite result. Dual luciferase reporter gene assay showed that miR-877-5p directly targeted eukaryotic translation initiation factor 4γ2 (EIF4G2). Overexpression of EIF4G2 inhibited osteogenic differentiation and reversed the promoting effect of overexpression of miR-135-5p on osteogenic differentiation. These results indicate that miR-877-5p might have a therapeutic application related to its promotion of bone formation through targeting EIF4G2.

circ_0029463 promotes osteoclast differentiation by mediating miR-134-5p/Rab27a axis

OBJECTIVE

Osteoporosis is the imbalance in bone homeostasis between osteoblasts and osteoclasts. In this study, we investigated the effects of the circ_0029463/miR-134-5p/Rab27a axis on RANKL-induced osteoclast differentiation.

METHODS

RT-qPCR and western blotting were used to detect the expression of circ_0029463, miR-134-5p, and Rab27a in tissues from patients with osteoporosis and in RANKL-induced osteoclasts. Osteoclast differentiation was verified by TRAP staining. Osteoclast biomarkers, including NFATc1, TRAP, and CTSK, were measured. The target and regulatory relationships between circ_0029463, miR-134-5p, and the Rab27a axis were verified using RIP, dual-luciferase reporter gene, and RNA pull-down assays.

RESULTS

Elevated expression of circ_0029463 and Rab27a and decreased miR-134-5p expression were observed in the tissues of patients with osteoporosis, and a similar expression pattern was observed in RANKL-induced osteoclasts. Suppression of circ_0029463 expression or miR-134-5p overexpression curbed RANKL-induced osteoclast differentiation, whereas such an effect was abolished by Rab27 overexpression. circ_0029463 sponges miR-134-5p to induce Rab27a expression.

CONCLUSION

circ_0029463 sponges miR-134-5p to abolish its suppressive effect of miR-134-5p on Rab27a expression, thereby promoting osteoclast differentiation.

Aseptic loosening around total joint replacement in humans is regulated by miR-1246 and miR-6089 via the Wnt signalling pathway

BACKGROUND

Total joint replacement for osteoarthritis is one of the most successful surgical procedures in modern medicine. However, aseptic loosening continues to be a leading cause of revision arthroplasty. The diagnosis of aseptic loosening remains a challenge as patients are often asymptomatic until the late stages. MicroRNA (miRNA) has been demonstrated to be a useful diagnostic tool and has been successfully used in the diagnosis of other diseases. We aimed to identify differentially expressed miRNA in the plasma of patients with aseptic loosening.

METHODS

Adult patients undergoing revision arthroplasty for aseptic loosening and age- and gender-matched controls were recruited. Samples of bone, tissue and blood were collected, and RNA sequencing was performed in 24 patients with aseptic loosening and 26 controls. Differentially expressed miRNA in plasma was matched to differentially expressed mRNA in periprosthetic bone and tissue. Western blot was used to validate protein expression.

RESULTS

Seven miRNA was differentially expressed in the plasma of patients with osteolysis (logFC >|2|, adj-P < 0.05). Three thousand six hundred and eighty mRNA genes in bone and 427 mRNA genes in tissue samples of osteolysis patients were differentially expressed (logFC >|2|, adj-P < 0.05). Gene enrichment analysis and pathway analysis revealed two miRNA (miR-1246 and miR-6089) had multiple gene targets in the Wnt signalling pathway in the local bone and tissues which regulate bone metabolism.

CONCLUSION

These results suggest that aseptic loosening may be regulated by miR-1246 and miR-6089 via the Wnt signalling pathway.

Mechanistic role of quercetin as inhibitor for adenosine deaminase enzyme in rheumatoid arthritis: systematic review

Rheumatoid arthritis (RA) is an autoimmune disease involving T and B lymphocytes. Autoantibodies contribute to joint deterioration and worsening symptoms. Adenosine deaminase (ADA), an enzyme in purine metabolism, influences adenosine levels and joint inflammation. Inhibiting ADA could impact RA progression. Intracellular ATP breakdown generates adenosine, which increases in hypoxic and inflammatory conditions. Lymphocytes with ADA play a role in RA. Inhibiting lymphocytic ADA activity has an immune-regulatory effect. Synovial fluid levels of ADA are closely associated with the disease's systemic activity, making it a useful parameter for evaluating joint inflammation. Flavonoids, such as quercetin (QUE), are natural substances that can inhibit ADA activity. QUE demonstrates immune-regulatory effects and restores T-cell homeostasis, making it a promising candidate for RA therapy. In this review, we will explore the impact of QUE in suppressing ADA and reducing produced the inflammation in RA, including preclinical investigations and clinical trials.

Inhibition of LINC00958 hinders the progression of osteoarthritis through regulation of the miR-214-3p/FOXM1 axis

OBJECTIVE

We investigated the impact of the long noncoding RNA LINC00958 on cellular activity and oxidative stress in osteoarthritis (OA).

METHODS

We performed bioinformatics analysis via StarBase and luciferase reporter assays to predict and validate the interactions between LINC00958 and miR-214-3p and between miR-214-3p and FOXM1. The expression levels of LINC00958, miR-214-3p, and FOXM1 were measured by qRT-PCR and western blotting. To assess effects on CHON-001 cells, we performed MTT proliferation assays, evaluated cytotoxicity with a lactate dehydrogenase (LDH) assay, and examined apoptosis through flow cytometry. Additionally, we measured the levels of apoptosis-related proteins, including BAX and BCL2, using western blotting. The secretion of inflammatory cytokines (IL-6, IL-8, and TNF-α) was measured using ELISA.

RESULTS

Our findings confirmed that LINC00958 is a direct target of miR-214-3p. LINC00958 expression was upregulated but miR-214-3p expression was downregulated in both OA cells and IL-1β-stimulated CHON-001 cells compared to the corresponding control cells. Remarkably, miR-214-3p expression was further reduced after miR-214-3p inhibitor treatment but increased following LINC00958-siRNA stimulation. Silencing LINC00958 significantly decreased its expression, and this effect was reversed by miR-214-3p inhibitor treatment. Notably, LINC00958-siRNA transfection alleviated the IL-1β-induced inflammatory response, as evidenced by the increased cell viability, reduced LDH release, suppression of apoptosis, downregulated BAX expression, and elevated BCL2 levels. Moreover, LINC00958 silencing led to reduced secretion of inflammatory factors from IL-1β-stimulated CHON-001 cells. The opposite results were observed in the miR-214-3p inhibitor-transfected groups. Furthermore, in CHON-001 cells, miR-214-3p directly targeted FOXM1 and negatively regulated its expression.

CONCLUSION

Our findings suggest that downregulating LINC00958 mitigates IL-1β-induced injury in CHON-001 cells through the miR-214-3p/FOXM1 axis. These results imply that LINC00958 plays a role in OA development and may be a valuable therapeutic target for OA.

Circ_0000376 regulates miR-577/HK2/LDHA signaling pathway to promote the growth, invasion and glycolysis of osteosarcoma

BACKGROUND

Many studies have confirmed that circular RNAs (circRNAs) mediate the malignant progression of various tumors including osteosarcoma (OS). Our study is to uncover novel molecular mechanisms by which circ_0000376 regulates OS progression.

METHODS

The expression of circ_0000376, microRNA (miR)-577, hexokinase 2 (HK2) and lactate dehydrogenase-A (LDHA) was determined by quantitative real-time PCR. OS cell proliferation, apoptosis and invasion were measured using cell counting kit 8 assay, colony formation assay, EdU assay, flow cytometry and transwell assay. Besides, cell glycolysis was assessed by testing glucose consumption, lactate production, and ATP/ADP ratios. Protein expression was examined by western blot analysis. The interaction between miR-577 and circ_0000376 or HK2/LADA was verified by dual-luciferase reporter assay. The role of circ_0000376 on OS tumor growth was explored by constructing mice xenograft models.

RESULTS

Circ_0000376 had been found to be upregulated in OS tissues and cells. Functional experiments revealed that circ_0000376 interference hindered OS cell growth, invasion and glycolysis. Circ_0000376 sponged miR-577 to reduce its expression. In rescue experiments, miR-577 inhibitor abolished the regulation of circ_0000376 knockdown on OS cell functions. MiR-577 could target HK2 and LDHA in OS cells. MiR-577 suppressed OS cell growth, invasion and glycolysis, and these effects were reversed by HK2 and LDHA overexpression. Also, HK2 and LDHA expression could be regulated by circ_0000376. In vivo experiments showed that circ_0000376 knockdown inhibited OS tumorigenesis.

CONCLUSION

Circ_0000376 contributed to OS growth, invasion and glycolysis depending on the regulation of miR-577/HK2/LDHA axis, providing a potential target for OS treatment.

Circ_0006640 transferred by bone marrow-mesenchymal stem cell-exosomes suppresses lipopolysaccharide-induced apoptotic, inflammatory and oxidative injury in spinal cord injury

BACKGROUND

Emerging proofs have shown that differentially expressed circular RNAs (circRNAs) are closely associated with the pathophysiological process of spinal cord injury (SCI). Mesenchymal stem cell (MSC)-exosomes have been demonstrated to possess favorable therapeutic effects in diseases. Herein, this work aimed to investigate the action of circ_0006640 transferred by MSC-exosomes functional recovery after SCI.

METHODS

SCI animal models were established by spinal cord contusion surgery in mice and lipopolysaccharide (LPS)-stimulated mouse microglial cell line BV2. Levels of genes and proteins were detected by qRT-PCR and Western blot. Properties of BV2 cells were characterized using CCK-8 assay, flow cytometry and ELISA analysis. The oxidative stress was evaluated. Dual-luciferase reporter assay was used for verifying the binding between miR-382-5p and circ_0006640 or IGF-1 (Insulin-like Growth Factor 1). Exosome separation was conducted by using the commercial kit.

RESULTS

Circ_0006640 expression was lower in SCI mice and LPS-induced microglial cells. Circ_0006640 overexpression protected microglial cells from LPS-induced apoptotic, inflammatory and oxidative injury. Mechanistically, circ_0006640 directly sponged miR-382-5p, which targeted IGF-1. MiR-382-5p was increased, while IGF-1 was decreased in SCI mice and LPS-induced microglial cells. Knockdown of miR-382-5p suppressed apoptosis, inflammation and oxidative stress in LPS-induced microglial cells, which were reversed by IGF-1 deficiency. Moreover, miR-382-5p up-regulation abolished the protective functions of circ_0006640 in LPS-induced microglial cells. Additionally, circ_0006640 was packaged into MSC-exosomes and could be transferred by exosomes. Exosomal circ_0006640 also had protective effects on microglial cells via miR-382-5p/IGF-1 axis.

CONCLUSION

Circ_0006640 transferred by BMSC-exosomes suppressed LPS-induced apoptotic, inflammatory and oxidative injury via miR-382-5p/IGF-1 axis, indicating a new insight into the clinical application of exosomal circRNA-based therapeutic in the function recovery after SCI.