Silencing of miR-483-5p alleviates postmenopausal osteoporosis by targeting SATB2 and PI3K/AKT pathway

Eupatilin ameliorates postmenopausal osteoporosis via elevating microRNA-211-5p and repressing Janus kinase 2/Signal transducer and activator of transcription 3 pathway

This study explored the effect of Eupatilin on postmenopausal osteoporosis and explored the mechanisms associated with miR-211-5p. First, the rats were given intragastric administration of Eupatilin every day and subcutaneously injected once a week with oligonucleotides or plasmids that interfered with the expression of miR-211-5p or Janus kinase 2 (JAK2). After 4 weeks, a rat model of osteoporosis was established. Then, serum alkaline phosphatase, calcium and phosphorus levels were detected, as well as femur bone mineral density and biomechanical parameters. HE staining and Masson staining were applied for detecting the pathological condition of femur while immunohistochemical staining was for detecting the positive expression of osteocalcin. In addition, MC3T3-E1 cells were transfected with plasmid vectors interfering with miR-211-5p or JAK2, and cell viability, lactate dehydrogenase cytotoxicity, and cell mineralization were subsequently examined. The relationship between miR-211-5p and JAK2/Signal transducer and activator of transcription 3 (STAT3) pathway was analyzed, and the targeting of miR-211-5p and JAK2 was also verified. The experimental results found that Eupatilin improved the pathological conditions of osteoporotic rats by promoting the proliferation and mineralization of osteoblasts. miR-211-5p was down-regulated and JAK2/STAT3 were up-regulated in osteoporotic rats. Upregulation of miR-211-5p further improved the pathological conditions of osteoporotic rats based on Eupatilin treatment. MiR-211-5p inhibited the JAK2/STAT3 pathway. Upregulation of JAK2 reversed the effects of elevated miR-211-5p on osteoporotic rats. Overall, Eupatilin attenuates postmenopausal osteoporosis through elevating miR-211-5p and repressing JAK2/STAT3 pathway.

Luteolin rescues postmenopausal osteoporosis elicited by OVX through alleviating osteoblast pyroptosis via activating PI3K-AKT signaling

BACKGROUND

Recently, osteoblast pyroptosis has been proposed as a potential pathogenic mechanism underlying osteoporosis, although this remains to be confirmed. Luteolin (Lut), a flavonoid phytochemical, plays a critical role in the anti-osteoporosis effects of many traditional Chinese medicine prescriptions. However, its protective impact on osteoblasts in postmenopausal osteoporosis (PMOP) has not been elucidated.

PURPOSE

This research aimed to determine the effect of Lut in ameliorating PMOP by alleviating osteoblast pyroptosis and sustaining osteogenesis.

STUDY DESIGN

This research was designed to investigate the novel mechanism of Lut in alleviating PMOP both in cell and animal models.

METHODS

Ovariectomy-induced PMOP models were established in mice with/without daily gavaged of 10 or 20 mg/kg body weight Lut. The impact of Lut on bone microstructure, metabolism and oxidative stress was evaluated with 0.104 mg/kg body weight Estradiol Valerate Tablets daily gavaged as positive control. Network pharmacological analysis and molecular docking were employed to investigate the mechanisms of Lut in PMOP treatment. Subsequently, the impacts of Lut on the PI3K/AKT axis, oxidative stress, mitochondria, and osteoblast pyroptosis were assessed. In vitro, cultured MC3T3-E1(14) cells were exposed to H2O2 with/without Lut to examine its effects on the PI3K/AKT signaling pathway, osteogenic differentiation, mitochondrial function, and osteoblast pyroptosis.

RESULTS

Our findings demonstrated that 20 mg/kg Lut, similar to the positive control drug, effectively reduced systemic bone loss and oxidative stress, and enhanced bone metabolism induced by ovariectomy. Network pharmacological analysis and molecular docking indicated that the PI3K/AKT axis was a potential target, with oxidative stress response and nuclear membrane function being key mechanisms. Consequently, the effects of Lut on the PI3K/AKT axis and pyroptosis were investigated. In vivo data revealed that the PI3K/AKT axis was deactivated following ovariectomy, and Lut restored the phosphorylation of key proteins, thereby reactivating the axis. Additionally, Lut alleviated osteoblast pyroptosis and mitochondrial abnormalities induced by ovariectomy. In vitro, Lut intervention mitigated the inhibition of the PI3K/AKT axis and osteogenesis, as well as H2O2-induced pyroptosis. Furthermore, Lut attenuated ROS accumulation and mitochondrial dysfunction. The effects of Lut, including osteogenesis restoration, anti-pyroptosis, and mitochondrial maintenance, were all reversed with LY294002 (a PI3K/AKT pathway inhibitor).

CONCLUSION

In summary, Lut could improve mitochondrial dysfunction, alleviate GSDME-mediated pyroptosis and maintain osteogenesis via activating the PI3K/AKT axis, offering a new therapeutic strategy for PMOP.

[miRNA Is Involved in the Pathogenesis of Multiple Diseases by Targeting Osteoprotegerin]

As a member of the tumor necrosis factor receptor family, osteoprotegerin (OPG) is highly expressed in adults in the lung, heart, kidney, liver, spleen, thymus, prostate, ovary, small intestines, thyroid gland, lymph nodes, trachea, adrenal gland, the testis, and bone marrow. Together with the receptor activator of nuclear factor-κB (RANK) and the receptor activator of nuclear factor-κB ligand (RANKL), it forms the RANK/RANKL/OPG pathway, which plays an important role in the molecular mechanism of the development of various diseases. MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs performing regulatory functions in eukaryotes, with a size of about 20-25 nucleotides. miRNA genes are transcribed into primary transcripts by RNA polymerase, bind to RNA-induced silencing complexes, identify target mRNAs through complementary base pairing, with a single miRNA being capable of targeting hundreds of mRNAs, and influence the expression of many genes through pathways involved in functional interactions. In recent years, a large number of studies have been done to explore the mechanism of action of miRNA in diseases through miRNA isolation, miRNA quantification, miRNA spectrum analysis, miRNA target detection, in vitro and in vivo regulation of miRNA levels, and other technologies. It was found that miRNA can play a key role in the pathogenesis of osteoporosis, rheumatoid arthritis, and other diseases by targeting OPG. The purpose of this review is to explore the interaction between miRNA and OPG in various diseases, and to propose new ideas for studying the mechanism of action of OPG in diseases.

Enhancing postmenopausal osteoporosis: a study of KLF2 transcription factor secretion and PI3K-Akt signaling pathway activation by PIK3CA in bone marrow mesenchymal stem cells

Introduction

Mesenchymal stem cells can develop into osteoblasts, making them a promising cell-based osteoporosis treatment. Despite their therapeutic potential, their molecular processes are little known. Bioinformatics and experimental analysis were used to determine the molecular processes of bone marrow mesenchymal stem cell (BMSC) therapy for postmenopausal osteoporosis (PMO).

Material and methods

We used weighted gene co-expression network analysis (WGCNA) to isolate core gene sets from two GEO microarray datasets (GSE7158 and GSE56815). GeneCards found PMO-related genes. GO, KEGG, Lasso regression, and ROC curve analysis refined our candidate genes. Using the GSE105145 dataset, we evaluated KLF2 expression in BMSCs and examined the link between KLF2 and PIK3CA using Pearson correlation analysis. We created a protein-protein interaction network of essential genes involved in osteoblast differentiation and validated the functional roles of KLF2 and PIK3CA in BMSC osteoblast differentiation in vitro.

Results

We created 6 co-expression modules from 10 419 differentially expressed genes (DEGs). PIK3CA, the key gene in the PI3K-Akt pathway, was among 197 PMO-associated DEGs. KLF2 also induced PIK3CA transcription in PMO. BMSCs also expressed elevated KLF2. BMSC osteoblast differentiation involved the PI3K-Akt pathway. In vitro, KLF2 increased PIK3CA transcription and activated the PI3K-Akt pathway to differentiate BMSCs into osteoblasts.

Conclusions

BMSCs release KLF2, which stimulates the PIK3CA-dependent PI3K-Akt pathway to treat PMO. Our findings illuminates the involvement of KLF2 and the PI3K-Akt pathway in BMSC osteoblast development, which may lead to better PMO treatments.

Eupatilin ameliorates postmenopausal osteoporosis via elevating microRNA-211-5p and repressing JAK2/STAT3 pathway

Postmenopausal osteoporosis (PMOP) poses a significant threat to women's health worldwide. Eupatilin is a key bioactive component of the Chinese herbal medicine Artemisia asiatica Nakai. Recent research reports have proved the inhibitory function of Eupatilin in many diseases. MicroRNAs (miRNAs) are 21-23 nucleotide-long, single-stranded, noncoding RNA molecules generated endogenously, and many studies have indicated that miRNAs are involved in the development of osteoporosis. This study explored the role and potential mechanism of Eupatilin underlying PMOP. First, rats were given intragastric administration of Eupatilin every day and subcutaneous injections of oligonucleotides or plasmids that interfered with miR-211-5p or janus kinase 2 (JAK2) once a week. After 4 weeks, the PMOP rat model was established. Then, serum alkaline phosphatase, calcium, and phosphorus levels, as well as femur bone mineral density and biomechanical parameters, were detected. Hematoxylin-eosin staining and Masson staining were applied for detecting the pathological condition of femur, and immunohistochemical staining was for detecting osteocalcin. MC3T3-E1 cells were transfected with plasmid vectors interfering with miR-211-5p or JAK2; and cell viability, lactate dehydrogenase cytotoxicity, and cell mineralization were subsequently examined. The relationship between miR-211-5p and JAK2/signal transducer and activator of transcription 3 (STAT3) pathway was analyzed. The targeting relation between miR-211-5p and JAK2 was also verified. The experimental results revealed that Eupatilin improved the pathological conditions of PMOP rats by promoting the proliferation and mineralization of osteoblasts. MiR-211-5p was down-regulated and JAK2/STAT3 was upregulated in PMOP rats. Upregulation of miR-211-5p further improved the pathological conditions of PMOP rats based on Eupatilin treatment. MiR-211-5p inhibited the JAK2/STAT3 pathway. JAK2 offset the effects of elevated miR-211-5p on PMOP rats. Overall, Eupatilin attenuates PMOP through elevating miR-211-5p and repressing JAK2/STAT3 pathway, which suggests the utility of Eupatilin as a potential drug for POMP treatment.

Identification of a potential signature to predict the risk of postmenopausal osteoporosis

BACKGROUND

Postmenopausal osteoporosis (PMOP) is related to the elevated risk of fracture in postmenopausal women. Thus, to effectively predict the occurrence of PMOP, we explored a novel gene signature for the prediction of PMOP risk.

METHODS

The WGCNA analysis was conducted to identify the PMOP-related gene modules based on the data from GEO database (GSE56116 and GSE100609). The "limma" R package was applied for screening differentially expressed genes (DEGs) based on the data from GSE100609 dataset. Next, LASSO Cox algorithm were applied to identify valuable PMOP-related risk genes and construct a risk score model. GSEA was then conducted to analyze potential signaling pathways between high-risk (HR) score and low-risk (LR) score groups.

RESULTS

A novel risk model with five PMOP-related risk genes (SCUBE3, TNNC1, SPON1, SEPT12 and ULBP1) was developed for predicting PMOP risk status. RT-qPCR and western blot assays validated that compared to postmenopausal non-osteoporosis (non-PMOP) patients, SCUBE3, ULBP1, SEPT12 levels were obviously elevated, and TNNC1 and SPON1 levels were reduced in blood samples from PMOP patients. Additionally, PMOP-related pathways such as MAPK signaling pathway, PI3K-Akt signaling pathway and HIF-1 signaling pathway were significantly activated in the HR-score group compared to the LR-score group. The circRNA-gene-miRNA and gene-transcription factor networks showed that 533 miRNAs, 13 circRNAs and 40 TFs might be involved in regulating the expression level of these five PMOP-related genes.

CONCLUSION

Collectively, we developed a PMOP-related gene signature based on SCUBE3, TNNC1, SPON1, SEPT12 and ULBP1 genes, and higher risk score indicated higher risk suffering from PMOP.

Progress of epigenetic modification of SATB2 gene in the pathogenesis of non-syndromic cleft lip and palate

Non-syndromic Cleft Lip and Palate (NSCLP) is one of the most common congenital craniofacial malformations. However, there is no enough knowledge about its mechanism, even through many relevant studies verify that cleft lip and palate is caused by interactions between environmental and genetic factors. SATB2 gene is one of the most common candidate genes of NSCLP, and the development of epigenetics provides a new direction on pathogenesis of cleft lip and palate. This review summarizes SATB2 gene in the pathogenesis of non-syndromic cleft lip and palate, expecting to provide strategies to prevent and treat cleft and palate in the future.

Based on network pharmacology and molecular docking to explore the molecular mechanism of Ginseng and Astragalus decoction against postmenopausal osteoporosis

Traditional Chinese medicine suggests that Ginseng and Astragalus Decoction (GAD) may effectively treat postmenopausal osteoporosis (PMO). However, the exact mechanism of action for GAD remains unclear. This study aims to utilize network pharmacology and molecular docking technology to explore the potential mechanism of GAD in treating PMO. The main chemical components of GAD were identified by consulting literature and traditional Chinese medicine systems pharmacology database. GeneCards and online mendelian inheritance in man were used to identify PMO disease targets, and Cytoscape 3.8.2 software was used to construct a herb-disease-gene-target network. The intersection of drug targets and disease targets was introduced into the search tool for the retrieval of interacting genes platform to construct a protein-protein interaction network. Additionally, we further conducted gene ontology and Kyoto encyclopedia of genes and genomes enrichment analyses, followed by molecular docking between active ingredients and core protein targets. We have identified 59 potential targets related to the treatment of PMO by GAD, along with 33 effective components. Quercetin and kaempferol are the compounds with higher degree. In the protein-protein interaction network, IL6, AKT1, and IL1B are proteins with high degree. The enrichment analysis of gene ontology and KEEG revealed that biological processes involved in treating PMO with GAD mainly include response to hormones, positive regulation of phosphorylation, and regulation of protein homodimerization activity. The signal pathways primarily include Pathways in cancer, PI3K-Akt signaling pathway, and AGE-RAGE signaling pathway. Molecular docking results indicate that kaempferol and quercetin have a high affinity for IL6, AKT1, and IL1B. Our research predicts that IL6, AKT1, and IL1B are highly likely to be potential targets for treating PMO with GAD. PI3K/AKT pathway and AGE-ARGE pathway may play an important role in PMO.

Long non-coding RNA Homeobox D gene cluster antisense growth-associated long noncoding RNA/microRNA-182-5p/Homeobox protein A10 alleviates postmenopausal osteoporosis via accelerating osteoblast differentiation of bone marrow mesenchymal stem cells

BACKGROUND

Studies have illuminated that long non-coding RNA (lncRNA) influences bone cell differentiation and formation. Nevertheless, whether lncRNA Homeobox D gene cluster antisense growth-associated long noncoding RNA (HAGLR) was implicated in postmenopausal osteoporosis (PMOP) was yet uncertain.

PURPOSE

The research was to explore HAGLR's role in the osteogenic differentiation (OD) process of bone marrow mesenchymal stem cells (BMSCs).

METHODS

BMSCs were isolated from mouse bone marrow tissues and identified by electron microscope and flow cytometry. HAGLR, microRNA (miR)-182-5p, and homeobox protein A10 (Hoxa10) levels in BMSCs were detected. Mouse BMSC OD process was induced, and calcium deposition and alkaline phosphatase content were analyzed, as well as expressions of runt-related transcription factor 2, osteopontin, and osteocalcin, and cell apoptosis. Bilateral ovaries were resected from mice to construct the ovariectomized model and bone mineral density, maximum bending stress, maximum load, and elastic modulus of the femur were tested, and the femur was histopathologically evaluated. Chondrocyte apoptosis in the articular cartilage of mice was analyzed. Analysis of the interaction of HAGLR, miR-182-5p with Hoxa10 was conducted.

RESULTS

HAGLR and Hoxa10 were down-regulated and miR-182-5p was elevated in PMOP patients. During the BMSC OD process, HAGLR and Hoxa10 levels were suppressed, while miR-182-5p was elevated. Promotion of HAGLR or suppression of miR-182-5p accelerated OD of BMSCs. Inhibition of miR-182-5p reversed the inhibitory effect of HAGLR on BMSC OD. In in vivo experiments, up-regulating HAGLR alleviated PMOP, while silencing Hoxa10 reversed the effects of upregulating HAGLR. HAGLR performed as a sponge for miR-182-5p, while miR-182-5p targeted Hoxa10.

CONCLUSION

In general, HAGLR boosted the OD process of BMSCs and relieved PMOP via the miR-182-5p/Hoxa10 axis. These data preliminarily reveal the key role of HAGLR in PMOP, and the research results have a certain reference for the treatment of PMOP.

Mechanism of miRNA-31 Regulating Wnt/β-catenin Signaling Pathway by Targeting Satb2 in the Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells

OBJECTIVE

To explore the expression of miR-31 and Satb2 gene in the serum of postmenopausal women with osteoporosis (OP).

METHODS

97 postmenopausal women with OP and 100 healthy women were selected as research subjects. MSCs were purchased from Shanghai Zhong Qiao Xin Zhou Biotechnology Co., Ltd. Bone marrow-derived mesenchymal stem cells (BMSCs) were isolated, identified and transfected, and then quantified by alkaline phosphatase (ALP) levels. The expression levels of miR-31 and Satb2 gene mRNA were determined by qRT-PCR. The proteins of RUNX2, OCN and BMP and Wnt/β-catenin pathway-related proteins (GSK-3, Frizzled 1, Lrp5, Lrp6 and β-catenin) were tested by Western blotting.

RESULTS

In the OP group, the relative expression of miR-31 was 3.61±0.54, significantly higher than that (1.75±0.27) in the healthy control group (t=9.422, P<0.001). The relative expression of mRNA of Satb2 gene was 0.86±0.12, significantly lower than that (1.35±0.21) in the healthy control group (t=5.897, P<0.001).

CONCLUSIONS

The increase in miR-31 expression can down-regulate the Wnt/β-catenin pathway by targeting the expression of Satb2 gene, thereby inhibiting the osteogenic differentiation of BMSCs. This provides an important reference for further understanding the mechanism of OP and identifying targets for early diagnosis and treatment.

Common miRNAs of Osteoporosis and Fibromyalgia: A Review

A significant clinical association between osteoporosis (OP) and fibromyalgia (FM) has been shown in the literature. Given the need for specific biomarkers to improve OP and FM management, common miRNAs might provide promising tracks for future prevention and treatment. The aim of this review is to identify miRNAs described in OP and FM, and dysregulated in the same direction in both pathologies. The PubMed database was searched until June 2023, with a clear mention of OP, FM, and miRNA expression. Clinical trials, case-control, and cross-sectional studies were included. Gray literature was not searched. Out of the 184 miRNAs found in our research, 23 are shared by OP and FM: 7 common miRNAs are dysregulated in the same direction for both pathologies (3 up-, 4 downregulated). The majority of these common miRNAs are involved in the Wnt pathway and the cholinergic system and a possible link has been highlighted. Further studies are needed to explore this relationship. Moreover, the harmonization of technical methods is necessary to confirm miRNAs shared between OP and FM.

Aberrant expression of miR-33a-3p/IGF2 in postmenopausal osteoporosis patients and its role and mechanism in osteoporosis

BACKGROUND

Postmenopausal osteoporosis (PMOP), the most frequent bone-related disease, is characterized by bone loss and fragile fractures, which is related to low bone density (BMD). This study aimed to illustrate the expression and mechanism of miR-33a-3p in osteoporosis.

METHODS

TargetScan and luciferase reporter assay were applied for verifying the relevance between miR-33a-3p and IGF2. Levels of miR-33a-3p, IGF2, Runx2, ALP and Osterix were checked using RT-qPCR and western blotting. hBMSCs proliferation, apoptosis and ALP activity were analyzed by MTT, flow cytometry (FCM) analysis and ALP detection kit, respectively. Moreover, the calcification of cells was assessed using Alizarin Red S staining. The average BMD was evaluated by dual-energy X-ray absorptiometry (DEXA) assay.

RESULTS

IGF2 was a target of miR-33a-3p. The level of miR-33a-3p was substantially higher and IGF2 expression was memorably lower in the serum of osteoporosis patients than that in healthy volunteers. Our results also pointed out that miR-33a-3p was reduced and IGF2 expression was enhanced during osteogenic differentiation. We concluded that miR-33a-3p negatively regulated the level of IGF2 in hBMSCs. Besides, miR-33a-3p mimic inhibited the osteogenic differentiation of hBMSCs via inhibiting the level of Runx2, ALP and Osterix and decreasing ALP activity. IGF2 plasmid dramatically reversed the influence of miR-33a-3p mimic on IGF2 expression, hBMSCs proliferation and apoptosis, and osteogenic differentiation of hBMSCs.

CONCLUSION

miR-33a-3p affected osteogenic differentiation of hBMSCs by targeting IGF2, indicating a potential use of miR-33a-3p as plasma biomarker and therapeutic target for postmenopausal osteoporosis.

Adenovirus-associated anti-miRNA-214 regulates bone metabolism and prevents local osteoporosis in rats

Objective: We investigated the expression of miRNA-214 in human osteoporotic bone tissue and tested the utility of adeno-associated virus (AAV) expressing a miRNA-214 inhibitor in terms of preventing local osteoporosis of the femoral condyle in a rat model of osteoporosis. Methods: (1) Femoral heads of patients who underwent hip replacements at our hospital because of femoral neck fractures were collected and divided into osteoporosis and non-osteoporosis groups based on preoperative bone mineral density data. MiRNA-214 expression was detected in bone tissues exhibiting obvious bone microstructural changes in the two groups. (2) A total of 144 SD female rats were divided into four groups: the Control, Model, Negative control (Model + AAV), and Experimental (Model + anti-miRNA-214) groups. AAV-anti-miRNA-214 was injected locally into the rat femoral condyles; we explored whether this prevented or treated local osteoporosis. Results: (1) MiRNA-214 expression in the human femoral head was significantly increased in the osteoporosis group. (2) Compared to the Model and Model + AAV groups, the bone mineral density (BMD) and femoral condyle bone volume/tissue volume (BV/TV) ratio in the Model + anti-miRNA-214 group were significantly higher; in addition, the number (TB.N) and thickness (TB.Th) of the trabecular bones were increased (all p < 0.05). MiRNA-214 expression in the femoral condyles of the Model + anti-miRNA-214 group was significantly higher than that in the other groups. The expression levels of the osteogenesis-related genes Alp, Bglap, and Col1α1 increased, while those of the osteoclast-related genes NFATc1, Acp5, Ctsk, Mmp9, and Clcn7 decreased. Conclusion: AAV-anti-miRNA-214 promoted osteoblast activity and inhibited osteoclast activity in the femoral condyles of osteoporotic rats, improving bone metabolism and slowing osteoporosis progression.

Brain-derived extracellular vesicles promote bone-fat imbalance in Alzheimer's disease

Inadequate osteogenesis and excessive adipogenesis of bone marrow mesenchymal stem cells (BMSCs) are key factors in the pathogenesis of osteoporosis. Patients with Alzheimer's disease (AD) have a higher incidence of osteoporosis than healthy adults, but the underlying mechanism is not clear. Here, we show that brain-derived extracellular vesicles (EVs) from adult AD or wild-type mice can cross the blood-brain barrier to reach the distal bone tissue, while only AD brain-derived EVs (AD-B-EVs) significantly promote the shift of the BMSC differentiation fate from osteogenesis to adipogenesis and induce a bone-fat imbalance. MiR-483-5p is highly enriched in AD-B-EVs, brain tissues from AD mice, and plasma-derived EVs from AD patients. This miRNA mediates the anti-osteogenic, pro-adipogenic, and pro-osteoporotic effects of AD-B-EVs by inhibiting Igf2. This study identifies the role of B-EVs as a promoter of osteoporosis in AD by transferring miR-483-5p.

Application and Molecular Mechanisms of Extracellular Vesicles Derived from Mesenchymal Stem Cells in Osteoporosis

Osteoporosis (OP) is a chronic bone disease characterized by decreased bone mass, destroyed bone microstructure, and increased bone fragility. Accumulative evidence shows that extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) (MSC-EVs), especially exosomes (Exos), exhibit great potential in the treatment of OP. However, the research on MSC-EVs in the treatment of OP is still in the initial stage. The potential mechanism has not been fully clarified. Therefore, by reviewing the relevant literature of MSC-EVs and OP in recent years, we summarized the latest application of bone targeted MSC-EVs in the treatment of OP and further elaborated the potential mechanism of MSC-EVs in regulating bone formation, bone resorption, bone angiogenesis, and immune regulation through internal bioactive molecules to alleviate OP, providing a theoretical basis for the related research of MSC-EVs in the treatment of OP.

S-Equol enhances osteoblastic bone formation and prevents bone loss through OPG/RANKL via the PI3K/Akt pathway in streptozotocin-induced diabetic rats

Background

This study aimed to explore whether S-Equol delays diabetes-induced osteoporosis and the molecular mechanisms underlying its therapeutic effects.

Materials and methods

Thirty-five male Sprague–Dawley rats were randomized into five groups. The diabetic osteoporosis (DOP) group and three S-Equol treatment groups were intraperitoneally injected with streptozotocin (STZ) to develop a DOP model. After the 12-week intervention, bone transformation indicators were detected using an enzyme-linked immunosorbent assay kit; bone mineral density (BMD) and bone microstructure were obtained using dual-energy X-ray absorptiometry and microCT; morphological changes in the bone tissue were investigated using HE staining; bone morphogenetic proteins were detected using immunohistochemical staining. ROS17/2.8 cells were cultured in vitro, and Cell Counting Kit-8 was used to test the protective effects of S-Equol in osteoblastic cells in a high-fat and high-glucose environment. Furthermore, the expression of osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), estrogen receptor β(ERβ), phosphorylated Akt (pAKT)/protein kinase B (AKT), and osteocalcin (OC) in bone tissue and ROS17/2.8 cells was assessed using reverse transcription polymerase chain reaction (RT-PCR) and western blotting. To determine whether ERβ and phosphatidylinositol 3’ -kinase (PI3K)/AKT signaling pathways are involved in the process, LY294002 (PI3K signaling pathway inhibitor) and small interfering RNA targeting ERβ mRNA (si-ERβ) were used to verify the function of the ERβ-mediated PI3K/AKT pathway in this process.

Results

After the 12-week intervention, S-Equol enhanced BMD, improved bone microarchitecture in DOP rats (P < 0.05), and improved markers of bone metabolism (P < 0.05). In vitro, 10^–6 mmol/L S-Equol was selected to significantly protect osteoblasts from high- and high-glucose environments (P < 0.05). Gene expression of OPG, ERβ, pAKT/AKT, and OC was upregulated compared to the DOP group, and RANKL was downregulated compared to the DOP group (P < 0.05) both in bone tissue and osteoblastic cells. The promotion of OPG and pAKT/AKT is mediated by LY294002 and siERβ.

Conclusion

S-Equol binds to ERβ to regulate OPG/RANKL via the PI3K/AKT pathway and improve DOP. Our results demonstrate the potential role of S-Equol in the treatment of DOP by targeting ERβ. Thus, S-Equol may have the potential to be an adjuvant drug for treating DOP.

Qing`e Pill Inhibits Osteoblast Ferroptosis via ATM Serine/Threonine Kinase (ATM) and the PI3K/AKT Pathway in Primary Osteoporosis

Osteoporosis (OP) is an aging-related disease that is the main etiology of fragility fracture. Qing’e Pill (QEP) is a mixture of traditional Chinese medicine (TCM) consisting of Eucommia ulmoides Oliv., Psoralea corylifolia L., Juglans regia L., and Allium sativum L. QEP has an anti-osteoporosis function, but the underlying mechanism remains unclear. In this study, online databases were employed to determine the chemical compounds of QEP and potential target genes in osteoporosis. Potential pathways associated with genes were defined by Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) databases. A compound–target–disease network was constructed. Hub genes screened through Cytoscape were intersected with the FerrDB database. The potential key genes were validated in HFOB 1.19 cells, and rat models were ovariectomized through Western blot, RT-qPCR, ELISA, HE staining, immunohistochemistry, and immunofluorescence analyses. The intersection targets of QEP and osteoporosis contained 121 proteins, whereas the target–pathway network included 156 pathways. We filtered five genes that stood out in the network analysis for experimental verification. The experiments validated that QEP exerted therapeutic effects on osteoporosis by inhibiting ferroptosis and promoting cell survival via the PI3K/AKT pathway and ATM. In conclusion, combining the application of network analysis and experimental verification may provide an efficient method to validate the molecular mechanism of QEP on osteoporosis.

miRNA-Gene Interaction Network Construction Strategy to Discern Promising Traditional Chinese Medicine against Osteoporosis

Osteoporosis is a widespread bone disease that affects million cases annually. The underlying mechanisms behind the progress of osteoporosis remain enigmatic, which limits detections of biomarkers and therapeutic targets. Hence, this study was aimed at exploring hub molecules to better understand the mechanism of osteoporosis development and discover the traditional Chinese medicine potential drugs for osteoporosis. miRNA and gene expression profiles were downloaded from Gene Expression Omnibus (GEO). Weighted correlation network analysis (WGCNA) was used to identify the key modules for osteoporosis. DIANA Tools was applied to perform pathway enrichment. A miRNA-gene interaction network was constructed, and hub miRNAs and genes were distinguished using Cytoscape software. Receiver operating characteristic (ROC) curves of hub miRNAs and genes were plotted, and correlations with hub genes and osteoporosis-associated factors were evaluated. Potential drugs for osteoporosis in Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) were screened, and molecular docking models between these drugs and target genes were showed by AutoDock tools. Two hub modules, 1 miRNA module and 1 gene module, were identified to be the most strongly correlated with osteoporosis by using WGCNA. Then, 3 KEGG pathways including focal adhesion, PI3K-Akt signaling pathway, and gap junction were shared pathways enriched with the miRNAs and genes screened out by WGCNA and differential expression analyses. Finally, after constructing a miRNA-gene interaction network, 6 hub miRNAs (hsa-miR-18b-3p, hsa-miR-361-3p, hsa-miR-484, hsa-miR-519e-5p, hsa-miR-940, and hsa-miR-1275) and 6 hub genes (THBS1, IFNAR2, ARHGAP5, TUBB2B, FLNC, and NTF3) were detected. ROC curves showed good performances of miRNAs and genes for osteoporosis. Correlations with hub genes and osteoporosis-associated factors suggested implicational roles of them for osteoporosis. Based on these hub genes, 3 natural compounds (kainic acid, uridine, and quercetin), which were the active ingredients of 192 herbs, were screened out, and a target-compound-herb network was extracted using TCMSP. Molecular docking models of kainic acid-NTF3, uridine-IFNAR2, and quercetin-THBS1 were exhibited with AutoDock tools. Our study sheds light on the pathogenesis of osteoporosis and provides promising therapeutic targets and traditional Chinese medicine drugs for osteoporosis.

LncRNA BC083743 Silencing Exacerbated Osteoporosis by Regulating the miR-103-3p/SATB2 Axis to Inhibit Osteogenic Differentiation

Objective

The target of the present paper was to reveal the influence of LncRNA BC083743 on osteogenesis in human bone marrow mesenchymal stem cells (hBMSCs).

Methods

Serum specimens from osteoporotic patients and normal subjects were collected to isolate hBMSCs from femoral head tissue. The levels of BC083743 and miR-103-3p in serum and hBMSCs were measured by QRT-PCR. Alkaline phosphatase (ALP) activity test and alizarin red dyeing were used to identify ALP activity and mineralization forming ability of hBMSCs after transfection with si-BC083743 (siRNA-targeting BC083743). In addition, QRT-PCR and immunoblotting were conducted to identify the expressing levels of Runt-related transcription factor 2(Runx2), osteoprotegerin (OPG), and bone morphogenetic protein 2 (BMP2) in hBMSCs. Dual-luciferase reporter gene and RNA pull-down assays were employed to substantiate the binding of BC083743 to miR-103-3p and miR-103-3p to SATB2.

Results

BC083743 expression was significantly downregulated in sera from patients with osteoporosis, and osteogenic differentiation-related genes and BC083743 expression were obviously upregulated as the time to osteogenic differentiation increased. BC083743 knockdown hindered the osteogenic differentiation of hBMSCs. BC083743 was aimed at miR-103-3p and miR-103-3p inhibitors partially reversed the inhibitory effect of BC083743 downregulation on hBMSCs osteogenesis. BC083743 silencing downregulated SATB2 through uptake of miR-103-3p, thereby inhibiting hBMSCs osteogenesis to exacerbate osteoporosis.

Conclusion

BC083743/miR-103-3p/SATB2 axis inhibited osteogenic differentiation and exacerbated osteoporosis, which may offer brand-new molecular aims for the treatment of clinical osteoporosis.

Exosomal miR-483-5p in Bone Marrow Mesenchymal Stem Cells Promotes Malignant Progression of Multiple Myeloma by Targeting TIMP2

Bone marrow-derived mesenchymal stem cell (BMSC) is one crucial component of the multiple myeloma (MM) microenvironment and supports the malignant progression of MM. Whether BMSCs act on MM cells via exosomes has not been well characterized. Herein, we used microarrays to screen out differentially expressed miRNAs in BMSCs from patients with MM (MM-MSCs) or benign diseases (BD-MSCs). We found that miR-483-5p was highly expressed in MM-MSCs, which may be transported through exosomes from MM-MSCs to MM cells to increase miR-483-5p expression in them. We then investigated the role and mechanism of miR-483-5p in the aggressive progression of MM in vitro. We verified that miR-483-5p promoted MM cell proliferation and reduced apoptosis. Then we predicted and validated that TIMP2, a tumor suppressor gene, is the downstream target of miR-483-5p in MM. In summary, our study indicated that MM-MSCs promote MM malignant progression via the release of exosomes and regulation of miR-483-5p/TIMP2 axis, suggesting an essential role of BMSCs derived exosomal miRNA in MM and a potential marker for MM diagnosis and therapy.

Recent Progresses in the Treatment of Osteoporosis

Osteoporosis (OP) is a chronic bone disease characterized by aberrant microstructure and macrostructure of bone, leading to reduced bone mass and increased risk of fragile fractures. Anti-resorptive drugs, especially, bisphosphonates, are currently the treatment of choice in most developing countries. However, they do have limitations and adverse effects, which, to some extent, helped the development of anabolic drugs such as teriparatide and romosozumab. In patients with high or very high risk for fracture, sequential or combined therapies may be considered with the initial drugs being anabolic agents. Great endeavors have been made to find next generation drugs with maximal efficacy and minimal toxicity, and improved understanding of the role of different signaling pathways and their crosstalk in the pathogenesis of OP may help achieve this goal. Our review focused on recent progress with regards to the drug development by modification of Wnt pathway, while other pathways/molecules were also discussed briefly. In addition, new observations made in recent years in bone biology were summarized and discussed for the treatment of OP.