Exosomes from miRNA-378-modified adipose-derived stem cells prevent glucocorticoid-induced osteonecrosis of the femoral head by enhancing angiogenesis and osteogenesis via targeting miR-378 negatively regulated suppressor of fused (Sufu)

Mesenchymal stem cell-derived extracellular vesicles in joint diseases: Therapeutic effects and underlying mechanisms

Joint diseases greatly impact the daily lives and occupational functioning of patients globally. However, conventional treatments for joint diseases have several limitations, such as unsatisfatory efficacy and side effects, necessitating the exploration of more efficacious therapeutic strategies. Mesenchymal stem cell (MSC)-derived EVs (MSC-EVs) have demonstrated high therapeutic efficacyin tissue repair and regeneration, with low immunogenicity and tumorigenicity. Recent studies have reported that EVs-based therapy has considerable therapeutic effects against joint diseases, including osteoarthritis, tendon and ligament injuries, femoral head osteonecrosis, and rheumatoid arthritis. Herein, we review the therapeutic potential of various types of MSC-EVs in the aforementioned joint diseases, summarise the mechanisms underlying specific biological effects of MSC-EVs, and discuss future prospects for basic research on MSC-EV-based therapeutic modalities and their clinical translation. In general, this review provides an in-depth understanding of the therapeutic effects of MSC-EVs in joint diseases, as well as the underlying mechanisms, which may be beneficial to the clinical translation of MSC-EV-based treatment. The translational potential of this article: MSC-EV-based cell-free therapy can effectively promote regeneration and tissue repair. When used to treat joint diseases, MSC-EVs have demonstrated desirable therapeutic effects in preclinical research. This review may supplement further research on MSC-EV-based treatment of joint diseases and its clinical translation.

Global scientific trends on exosomes therapy for osteoporosis from 2004 to 2023: A bibliometric and visualized analysis

BACKGROUND

Exosomes have emerged as pivotal mediators in modulating physiological and pathological processes implicated in osteoporosis (OP) through their distinctive mode of intracellular communication. The use of exosomes has evoked considerable interest, catalyzing a surge in research endeavors on a global scale. This study endeavors to scrutinize contemporary landscapes and burgeoning trends in this realm.

METHODS

The Web of Science Core Collection was used to retrieve publications on exosomes therapy for OP within the time frame of January 1, 2004 to December 31, 2023. The bibliometric methodology was applied to study and index the collected data. VOSviewer and citespace software were used to conduct visualization, co-authorship, co-occurrence, and publication trend analyses of exosome therapy in OP.

RESULTS

A total of 610 publications (443 articles and 167 reviews) from 51 countries and 911 institutions were included in this study. Shanghai Jiao Tong University, Central South University, Sichuan University, and Zhejiang University are leading research institutions in this field. Stem Cell Research Therapy published the highest number of articles and has emerged as the most cited journal. Of the 4077 scholars who participated in the study, Xie, Hui, Zhang, Yan, Tan, and Yi-Juan had the largest number of articles. Furthermore, according to the cluster analysis of external keywords, future research hotspots can be categorized into 3 directions: research status of exosomes for the treatment of OP, treatment of OP through exosome-regulated signaling pathways, and exosomes as targeted drug delivery systems.

CONCLUSION

This study suggests that the number of future publications on exosome therapy for OP will increase, with a focus on fundamental investigations into drug-loading capacities and molecular mechanisms. In summary, this study presents the first systematic bibliometric analysis of exosome therapy publications in OP, providing an objective and comprehensive overview of the field and a valuable reference for researchers in this domain.

The Exosome-Mediated Bone Regeneration: An Advanced Horizon Toward the Isolation, Engineering, Carrying Modalities, and Mechanisms

Exosomes, nanoparticles secreted by various cells, composed of a bilayer lipid membrane, and containing bioactive substances such as proteins, nucleic acids, metabolites, etc., have been intensively investigated in tissue engineering owing to their high biocompatibility and versatile biofunction. However, there is still a lack of a high-quality review on bone defect regeneration potentiated by exosomes. In this review, the biogenesis and isolation methods of exosomes are first introduced. More importantly, the engineered exosomes of the current state of knowledge are discussed intensively in this review. Afterward, the biomaterial carriers of exosomes and the mechanisms of bone repair elucidated by compelling evidence are presented. Thus, future perspectives and concerns are revealed to help devise advanced modalities based on exosomes to overcome the challenges of bone regeneration. It is totally believed this review will attract special attention from clinicians and provide promising ideas for their future works.

Advances in the Pathogenesis of Steroid-Associated Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a refractory orthopedic condition characterized by bone cell ischemia, necrosis, bone trabecular fracture, and clinical symptoms such as pain, femoral head collapse, and joint dysfunction that can lead to disability. The disability rate of ONFH is very high, which imposes a significant economic burden on both families and society. Steroid-associated osteonecrosis of the femoral head (SANFH) is the most common type of ONFH. However, the pathogenesis of SANFH remains unclear, and it is an urgent challenge for orthopedic surgeons to explore it. In this paper, the pathogenesis of SANFH and its related signaling pathways were briefly reviewed to enhance comprehension of the pathogenesis and prevention of SANFH.

Recent advances in the use of extracellular vesicles from adipose-derived stem cells for regenerative medical therapeutics

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) isolated from adipose tissue. They possess remarkable properties, including multipotency, self-renewal, and easy clinical availability. ADSCs are also capable of promoting tissue regeneration through the secretion of various cytokines, factors, and extracellular vesicles (EVs). ADSC-derived EVs (ADSC-EVs) act as intercellular signaling mediators that encapsulate a range of biomolecules. These EVs have been found to mediate the therapeutic activities of donor cells by promoting the proliferation and migration of effector cells, facilitating angiogenesis, modulating immunity, and performing other specific functions in different tissues. Compared to the donor cells themselves, ADSC-EVs offer advantages such as fewer safety concerns and more convenient transportation and storage for clinical application. As a result, these EVs have received significant attention as cell-free therapeutic agents with potential future application in regenerative medicine. In this review, we focus on recent research progress regarding regenerative medical use of ADSC-EVs across various medical conditions, including wound healing, chronic limb ischemia, angiogenesis, myocardial infarction, diabetic nephropathy, fat graft survival, bone regeneration, cartilage regeneration, tendinopathy and tendon healing, peripheral nerve regeneration, and acute lung injury, among others. We also discuss the underlying mechanisms responsible for inducing these therapeutic effects. We believe that deciphering the biological properties, therapeutic effects, and underlying mechanisms associated with ADSC-EVs will provide a foundation for developing a novel therapeutic approach in regenerative medicine.

YTHDF2-Mediated m6A methylation inhibition by miR27a as a protective mechanism against hormonal osteonecrosis in BMSCs

BACKGROUND

With the increasing incidence of steroid-induced necrosis of the femoral head (SNFH), numerous scholars have investigated its pathogenesis. Current evidence suggests that the imbalance between lipogenesis and osteoblast differentiation in bone marrow mesenchymal stem cells (BMSCs) is a key pathological feature of SNFH. MicroRNAs (miRNAs) have strong gene regulatory effects and can influence the direction of cell differentiation. N6-methyladenosine (m6A) is a prevalent epigenetic modification involved in diverse pathophysiological processes. However, knowledge of how miRNAs regulate m6A-related factors that affect BMSC differentiation is limited.

OBJECTIVE

We aimed to investigate the role of miR27a in regulating the expression of YTHDF2 in BMSCs.

METHODS

We compared miR27a, YTHDF2, and total m6A mRNA levels in SNFH-affected and control BMSCs. CCK-8 and TUNEL assays were used to assess BMSC proliferation and apoptosis. Western blotting and qRT‒PCR were used to measure the expression of osteogenic (ALP, RUNX2, and OCN) and lipogenic (PPARγ and C/EBPα) markers. Alizarin Red and Oil Red O staining were used to quantify osteogenic and lipogenic differentiation, respectively. miR27a was knocked down or overexpressed to evaluate its impact on BMSC differentiation and its relationship with YTHDF2. Bioinformatics analyses identified YTHDF2 as a differentially expressed gene in SNFH (ROC analysis) and revealed potential signaling pathways through GSEA. The effects of YTHDF2 silencing on the lipogenic and osteogenic functions of BMSCs were assessed.

RESULTS

miR27a downregulation and YTHDF2 upregulation were observed in the SNFH BMSCs. miR27a knockdown/overexpression modulated YTHDF2 expression, impacting BMSC differentiation. miR27a silencing decreased m6A methylation and promoted osteogenic differentiation, while YTHDF2 silencing exerted similar effects. GSEA suggested potential signaling pathways associated with YTHDF2 in SNFH.

CONCLUSION

miR27a regulates BMSC differentiation through YTHDF2, affecting m6A methylation and promoting osteogenesis. This finding suggests a potential therapeutic target for SNFH.

Exosomes derived from M2 macrophages prevent steroid-induced osteonecrosis of the femoral head by modulating inflammation, promoting bone formation and inhibiting bone resorption

Inflammatory reactions are involved in the development of steroid-induced osteonecrosis of the femoral head(ONFH). Studies have explored the therapeutic efficacy of inhibiting inflammatory reactions in steroid-induced ONFH and revealed that inhibiting inflammation may be a new strategy for preventing the development of steroid-induced ONFH. Exosomes derived from M2 macrophages(M2-Exos) display anti-inflammatory properties. This study aimed to examine the preventive effect of M2-Exos on early-stage steroid-induced ONFH and explore the underlying mechanisms involved. In vitro, we explored the effect of M2-Exos on the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells(BMMSCs). In vivo, we investigated the role of M2-Exos on inflammation, osteoclastogenesis, osteogenesis and angiogenesis in an early-stage rat model of steroid-induced ONFH. We found that M2-Exos promoted the proliferation and osteogenic differentiation of BMMSCs. Additionally, M2-Exos effectively attenuated the osteonecrotic changes, inhibited the expression of proinflammatory mediators, promoted osteogenesis and angiogenesis, reduced osteoclastogenesis, and regulated the polarization of M1/M2 macrophages in steroid-induced ONFH. Taken together, our data suggest that M2-Exos are effective at preventing steroid-induced ONFH. These findings may be helpful for providing a potential strategy to prevent the development of steroid-induced ONFH.

ADSC-Exos enhance functional recovery after spinal cord injury by inhibiting ferroptosis and promoting the survival and function of endothelial cells through the NRF2/SLC7A11/GPX4 pathway

BACKGROUND

Spinal cord injury (SCI) is a devastating disease that causes major motor, sensory and autonomic dysfunctions. Currently, there is a lack of effective treatment. In this study, we aimed to investigate the potential mechanisms of Exosomes from adipose-derived stem cells (ADSC-Exos) in reducing ferroptosis and promoting angiogenesis after spinal cord injury.

METHODS

We isolated ADSC-Exos, the characteristics of which were confirmed. In vitro, we tested the potential of ADSC-Exos to promote the survival and function of human brain microvascular endothelial cells (HBMECs) and analyzed the ferroptosis of HBMECs. In vivo, we established rat models of SCI and locally injected ADSC-Exos to verify their efficacy.

RESULTS

ADSC-Exos can reduce reactive oxygen species (ROS) accumulation and cell damage induced by an excessive inflammatory response in HBMECs. ADSC-Exos inhibit ferroptosis induced by excessive inflammation and upregulate the expression of glutathione peroxidase 4(GPX4) in HBMECs. It can also effectively promote proliferation, migration, and vessel-like structure formation. In vitro, ADSC-Exos improved behavioral function after SCI and increased the number and density of blood vessels around the damaged spinal cord. Moreover, we found that ADSC-Exos could increase nuclear factor erythroid-2-related factor 2(NRF2) expression and nuclear translocation, thereby affecting the expression of solute carrier family 7 member 11(SLC7A11) and GPX4, and the NRF2 inhibitor ML385 could reverse the above changes.

CONCLUSION

Our results suggest that ADSC-Exos may inhibit ferroptosis and promote the recovery of vascular and neural functions after SCI through the NRF2/SLC7A11/GPX4 pathway. This may be a potential therapeutic mechanism for spinal cord injury.

Magnesium-containing bioceramics stimulate exosomal miR-196a-5p secretion to promote senescent osteogenesis through targeting Hoxa7/MAPK signaling axis

Stem cell senescence is characterized by progressive functional dysfunction and secretory phenotypic changes including decreased proliferation, dysfunction of osteogenic and angiogenic differentiation, increased secretion of the senescence-associated secretory phenotype (SASP), which bring difficulties for bone repair. Rescuing or delaying senescence of aged bone marrow mesenchymal stem cells (O-BMSCs) was considered as effective strategy for bone regeneration in aging microenvironment. Magnesium (Mg) ion released from bioceramics was reported to facilitate bone regeneration via enhancing osteogenesis and alleviating senescence. In this study, Akermanite biocreamics (Akt) containing Mg ion as a model was demonstrated to promote osteogenesis and angiogenesis effects of O-BMSCs by activating the MAPK signaling pathway in vitro. Moreover, the enhanced osteogenesis effects might be attributed to enhanced Mg-containing Akt-mediated exosomal miR-196a-5p cargo targeting Hoxa7 and activation of MAPK signaling pathway. Furthermore, the in vivo study confirmed that 3D-printed porous Mg-containing Akt scaffolds effectively increased bone regeneration in cranial defects of aged rats. The current results indicated that the exosomal-miR-196a-5p/Hoxa7/MAPK signaling axis might be the potential mechanism underlying Akt-mediated osteogenesis. The exosome-meditaed therapy stimulated by the released Mg ion contained in Akt biocreamics or other biomaterials might serve as a candidate strategy for bone repair in aged individuals.

Cortistatin prevents glucocorticoid-associated osteonecrosis of the femoral head via the GHSR1a/Akt pathway

Long-term use of glucocorticoids (GCs) is known to be a predominant cause of osteonecrosis of the femoral head (ONFH). Moreover, GCs can mediate apoptosis of various cell types by exaggerating oxidative stress. We have previously found that Cortistatin (CST) antagonizes oxidative stress and improves cell apoptosis in several conditions. In this study, we detected that the CST expression levels were diminished in patients with ONFH compared with femoral neck fracture (FNF). In addition, a GC-induced rat ONFH model was established, which impaired bone quality in the femoral head. Then, administration of CST attenuated these ONFH phenotypes. Furthermore, osteoblast and endothelial cells were cultured and stimulated with dexamethasone (Dex) in the presence or absence of recombinant CST. As a result, Dex induced impaired anabolic metabolism of osteoblasts and suppressed tube formation in endothelial cells, while additional treatment with CST reversed this damage to the cells. Moreover, blocking GHSR1a, a well-accepted receptor of CST, or blocking the AKT signaling pathway largely abolished the protective function of CST in Dex-induced disorder of the cells. Taken together, we indicate that CST has the capability to prevent GC-induced apoptosis and metabolic disorder of osteoblasts in the pathogenesis of ONFH via the GHSR1a/AKT signaling pathway.

Morroniside-mediated mitigation of stem cell and endothelial cell dysfunction for the therapy of glucocorticoid-induced osteonecrosis of the femoral head

BACKGROUND

Prolonged use of glucocorticoids (GCs) potentially lead to a condition known as GCs-induced osteonecrosis of the femoral head (GIONFH). The primary mechanisms underlying this phenomenon lies in stem cells and endothelial cells dysfunctions. Morroniside, an iridoid glycoside sourced from Cornus officinalis, possesses numerous biological capabilities, including combating oxidative stress, preventing apoptosis, opposing ischemic effects, and promoting the regeneration of bone tissue.

PURPOSE

This study aimed to analyze the impact of Morroniside on Dexamethasone (DEX)-induced dysfunction in stem cells and endothelial cells, and its potential as a therapeutic agent for GIONFH in rat models.

METHODS

ROS assay, JC-1 assay, and TUNEL assay were used to detect oxidative stress and apoptosis levels in vitro. For the evaluation of the osteogenic capability of bone marrow-derived mesenchymal stem cells, we employed ALP and ARS staining. Additionally, the angiogenic ability of endothelial cells was assessed using tube formation assay and migration assay. Microcomputed tomography analysis, hematoxylin-eosin staining, and immunohistochemical staining were utilized to evaluate the in vivo therapeutic efficacy of Morroniside.

RESULTS

Morroniside mitigates DEX-induced excessive ROS expression and cell apoptosis, effectively reducing oxidative stress and alleviating cell death. In terms of osteogenesis, Morroniside reverses DEX-induced osteogenic impairment, as evidenced by enhanced ALP and ARS staining, as well as increased osteogenic protein expression. In angiogenesis, Morroniside counteracts DEX-induced vascular dysfunction, demonstrated by an increase in tube-like structures in tube formation assays, a rise in the number of migrating cells, and elevated levels of angiogenic proteins. In vivo, our results further indicate that Morroniside alleviates the progression of GIONFH.

CONCLUSION

The experimental findings suggest that Morroniside concurrently mitigates stem cell and endothelial cell dysfunction through the PI3K/AKT signaling pathway both in vitro and in vivo. These outcomes suggest that Morroniside serves as a potential therapeutic agent for GIONFH.

Preparation of genetically or chemically engineered exosomes and their therapeutic effects in bone regeneration and anti-inflammation

The treatment of bone or cartilage damage and inflammation-related diseases has been a long-standing research hotspot. Traditional treatments such as surgery and cell therapy have only displayed limited efficacy because they can't avoid potential deterioration and ensure cell activity. Recently, exosomes have become a favorable tool for various tissue reconstruction due to their abundant content of proteins, lipids, DNA, RNA and other substances, which can promote bone regeneration through osteogenesis, angiogenesis and inflammation modulation. Besides, exosomes are also promising delivery systems because of stability in the bloodstream, immune stealth capacity, intrinsic cell-targeting property and outstanding intracellular communication. Despite having great potential in therapeutic delivery, exosomes still show some limitations in clinical studies, such as inefficient targeting ability, low yield and unsatisfactory therapeutic effects. In order to overcome the shortcomings, increasing studies have prepared genetically or chemically engineered exosomes to improve their properties. This review focuses on different methods of preparing genetically or chemically engineered exosomes and the therapeutic effects of engineering exosomes in bone regeneration and anti-inflammation, thereby providing some references for future applications of engineering exosomes.

Taxifolin-mediated Nrf2 activation ameliorates oxidative stress and apoptosis for the treatment of glucocorticoid-induced osteonecrosis of the femoral head

Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is the main complication secondary to long-term or excessive use of glucocorticoids (GCs). Taxifolin (TAX) is a natural antioxidant with various pharmacological effects, such as antioxidative stress and antiapoptotic properties. The purpose of this study was to explore whether TAX could regulate oxidative stress and apoptosis in GIONFH by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. We conducted qRT-PCR, Western blotting, TUNEL assays, flow cytometry, and other experiments in vitro. Microcomputed tomography analysis, hematoxylin-eosin staining, and immunohistochemical staining were performed to determine the therapeutic effect of TAX in vivo. TAX mitigated the overexpression of ROS and NOX gene expression induced by DEX, effectively reducing oxidative stress. Additionally, TAX could alleviate DEX-induced osteoblast apoptosis, as evidenced by qRT-PCR, Western blotting, and other experimental techniques. Our in vivo studies further demonstrated that TAX mitigates the progression of GIONFH in rats by combating oxidative stress and apoptosis. Mechanistic exploration revealed that TAX thwarts the progression of GIONFH through the activation of the Nrf2 pathway. Overall, our research herein reports that TAX-mediated Nrf2 activation ameliorates oxidative stress and apoptosis for the treatment of GIONFH.

Insight into Steroid-Induced ONFH: The Molecular Mechanism and Function of Epigenetic Modification in Mesenchymal Stem Cells

Osteonecrosis of the femoral head (ONFH) is a common refractory orthopedic disease, which is one of the common causes of hip pain and dysfunction. ONFH has a very high disability rate, which is associated with a heavy burden to patients, families, and society. The pathogenesis of ONFH is not completely clear. At present, it is believed that it mainly includes coagulation dysfunction, abnormal lipid metabolism, an imbalance of osteogenic/adipogenic differentiation, and poor vascularization repair. The prevention and treatment of ONFH has always been a great challenge for clinical orthopedic surgeons. However, recent studies have emphasized that the use of mesenchymal stem cells (MSCs) to treat steroid-induced ONFH (SONFH) is a promising therapy. This review focuses on the role and molecular mechanism of epigenetic regulation in the progress of MSCs in the treatment of SONFH, and discusses the significance of the latest research in the treatment of SONFH from the perspective of epigenetics.

Effects of Puerarin-Loaded Tetrahedral Framework Nucleic Acids on Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is recognized as a common refractory orthopedic disease that causes severe pain and poor quality of life in patients. Puerarin (Pue), a natural isoflavone glycoside, can promote osteogenesis and inhibit apoptosis of bone mesenchymal stem cells (BMSCs), demonstrating its great potential in the treatment of osteonecrosis. However, its low aqueous solubility, fast degradation in vivo, and inadequate bioavailability, limit its clinical application and therapeutic efficacy. Tetrahedral framework nucleic acids (tFNAs) are promising novel DNA nanomaterials in drug delivery. In this study, tFNAs as Pue carriers is used and synthesized a tFNA/Pue complex (TPC) that exhibited better stability, biocompatibility, and tissue utilization than free Pue. A dexamethasone (DEX)-treated BMSC model in vitro and a methylprednisolone (MPS)-induced ONFH model in vivo is also established, to explore the regulatory effects of TPC on osteogenesis and apoptosis of BMSCs. This findings showed that TPC can restore osteogenesis dysfunction and attenuated BMSC apoptosis induced by high-dose glucocorticoids (GCs) through the hedgehog and Akt/Bcl-2 pathways, contributing to the prevention of GC-induced ONFH in rats. Thus, TPC is a promising drug for the treatment of ONFH and other osteogenesis-related diseases.

microRNAs delivered by small extracellular vesicles in MSCs as an emerging tool for bone regeneration

Bone regeneration is a dynamic process that involves angiogenesis and the balance of osteogenesis and osteoclastogenesis. In bone tissue engineering, the transplantation of mesenchymal stem cells (MSCs) is a promising approach to restore bone homeostasis. MSCs, particularly their small extracellular vesicles (sEVs), exert therapeutic effects due to their paracrine capability. Increasing evidence indicates that microRNAs (miRNAs) delivered by sEVs from MSCs (MSCs-sEVs) can alter gene expression in recipient cells and enhance bone regeneration. As an ideal delivery vehicle of miRNAs, MSCs-sEVs combine the high bioavailability and stability of sEVs with osteogenic ability of miRNAs, which can effectively overcome the challenge of low delivery efficiency in miRNA therapy. In this review, we focus on the recent advancements in the use of miRNAs delivered by MSCs-sEVs for bone regeneration and disorders. Additionally, we summarize the changes in miRNA expression in osteogenic-related MSCs-sEVs under different microenvironments.

The functions and clinical application potential of exosomes derived from mesenchymal stem cells on wound repair: a review of recent research advances

Wound repair is a complex problem for both clinical practitioners and scientific investigators. Conventional approaches to wound repair have been associated with several limitations, including prolonged treatment duration, high treatment expenses, and significant economic and psychological strain on patients. Consequently, there is a pressing demand for more efficacious and secure treatment modalities to enhance the existing treatment landscapes. In the field of wound repair, cell-free therapy, particularly the use of mesenchymal stem cell-derived exosomes (MSC-Exos), has made notable advancements in recent years. Exosomes, which are small lipid bilayer vesicles discharged by MSCs, harbor bioactive constituents such as proteins, lipids, microRNA (miRNA), and messenger RNA (mRNA). These constituents facilitate material transfer and information exchange between the cells, thereby regulating their biological functions. This article presents a comprehensive survey of the function and mechanisms of MSC-Exos in the context of wound healing, emphasizing their beneficial impact on each phase of the process, including the regulation of the immune response, inhibition of inflammation, promotion of angiogenesis, advancement of cell proliferation and migration, and reduction of scar formation.

Bone-Targeted Exosomes: Strategies and Applications

As the global population ages, bone-related diseases have increasingly become a major social problem threatening human health. Exosomes, as natural cell products, have been used to treat bone-related diseases due to their superior biocompatibility, biological barrier penetration, and therapeutic effects. Moreover, the modified exosomes exhibit strong bone-targeting capabilities that may improve efficacy and avoid systemic side effects, demonstrating promising translational potential. However, a review of bone-targeted exosomes is still lacking. Thus, the recently developed exosomes for bone-targeting applications in this review are focused. The biogenesis and bone-targeting regulatory functions of exosomes, the constructive strategies of modified exosomes to improve bone-targeting, and their therapeutic effects for bone-related diseases are introduced. By summarizing developments and challenges in bone-targeted exosomes, It is striven to shed light on the selection of exosome constructive strategies for different bone diseases and highlight their translational potential for future clinical orthopedics.

The multiple regulatory effects of white adipose tissue on bone homeostasis

White adipose tissue (WAT) is not only an energy storage reservoir that is critical in energy homeostasis but is also a highly metabolically active endocrine organ. WAT can secrete a variety of adipocytokines, including leptin (LEP), adiponectin (APN), resistin, visfatin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and osteopontin (OPN). It can also synthesize and secrete exosomes, which enhance intercellular communication and participate in various physiological processes in the body. It can also synthesize and secrete exosomes to enhance intercellular communication and participate in a variety of physiological processes in the body. The skeleton is an important organ for protecting internal organs. It forms the scaffolding of the body and gives the body its basic form. It drives muscle contraction to produce movement under the regulation of the nervous system. It is also an important hematopoietic organ; and it is regulated by the cytokines secreted by WAT. As research related to the release of adipocytokines from WAT to affect the skeleton continues to progress, an inextricable link between bone lipid regulation has been identified. In this paper, we review the literature to summarize the structure, function and metabolism of WAT, elaborate the specific molecular mechanisms by which WAT-secreted hormones, cytokines and exosomes regulate skeletal cells, provide a theoretical basis for the in-depth study of WAT cross-organ regulation of bone, and provide new ideas for finding new adipose-secreted targeting factors for the treatment of skeletal diseases.

Current concepts of microRNA-mediated regulatory mechanisms in human pulp tissue-derived stem cells: a snapshot in the regenerative dentistry

One of the most studied class of non-coding RNAs is microRNAs (miRNAs) which regulate more than 60% of human genes. A network of miRNA gene interactions participates in stem cell self-renewal, proliferation, migration, apoptosis, immunomodulation, and differentiation. Human pulp tissue-derived stem cells (PSCs) are an attractive source of dental mesenchymal stem cells (MSCs) which comprise human dental pulp stem cells (hDPSCs) obtained from the dental pulp of permanent teeth and stem cells isolated from exfoliated deciduous teeth (SHEDs) that would be a therapeutic opportunity in stomatognathic system reconstruction and repair of other damaged tissues. The regenerative capacity of hDPSCs and SHEDs is mediated by osteogenic, odontogenic, myogenic, neurogenic, angiogenic differentiation, and immunomodulatory function. Multi-lineage differentiation of PSCs can be induced or inhibited by the interaction of miRNAs with their target genes. Manipulating the expression of functional miRNAs in PSCs by mimicking miRNAs or inhibiting miRNAs emerged as a therapeutic tool in the clinical translation. However, the effectiveness and safety of miRNA-based therapeutics, besides higher stability, biocompatibility, less off-target effects, and immunologic reactions, have received particular attention. This review aimed to comprehensively overview the molecular mechanisms underlying miRNA-modified PSCs as a futuristic therapeutic option in regenerative dentistry.

Angiogenesis coupled with osteogenesis in a bone tissue engineering scaffold enhances bone repair in osteoporotic bone defects

Increased life expectancy has resulted in an increase in osteoporosis incidence worldwide. The coupling of angiogenesis and osteogenesis is indispensable for bone repair. Although traditional Chinese medicine (TCM) exerts therapeutic effects on osteoporosis, TCM-related scaffolds, which focus on the coupling of angiogenesis and osteogenesis, have not yet been used for the treatment of osteoporotic bone defects.Panax notoginsengsaponin (PNS), the active ingredient ofPanax notoginseng, was added to a poly (_L-lactic acid) (PLLA) matrix. Osteopractic total flavone (OTF), the active ingredient ofRhizoma Drynariae, was encapsulated in nano-hydroxyapatite/collagen (nHAC) and added to the PLLA matrix. Magnesium (Mg) particles were added to the PLLA matrix to overcome the bioinert character of PLLA and neutralize the acidic byproducts generated by PLLA. In this OTF-PNS/nHAC/Mg/PLLA scaffold, PNS was released faster than OTF. The control group had an empty bone tunnel; scaffolds containing OTF:PNS = 100:0, 50:50, and 0:100 were used as the treatment groups. Scaffold groups promoted new vessel and bone formation, increased the osteoid tissue, and suppressed the osteoclast activity around osteoporotic bone defects. Scaffold groups upregulated the expression levels of angiogenic and osteogenic proteins. Among these scaffolds, the OTF-PNS (50:50) scaffold exhibited a better capacity for osteogenesis than the OTF-PNS (100:0 and 0:100) scaffolds. Activation of the bone morphogenic protein (BMP)-2/BMP receptor (BMPR)-1A/runt-related transcription factor (RUNX)-2signaling pathway may be a possible mechanism for the promotion of osteogenesis. Our study demonstrated that the OTF-PNS/nHAC/Mg/PLLA scaffold could promote osteogenesis via the coupling of angiogenesis and osteogenesis in osteoporotic rats with bone defects, and activating theBMP-2/BMPR1A/RUNX2signaling pathway may be an osteogenesis-related mechanism. However, further experiments are necessary to facilitate its practical application in the treatment of osteoporotic bone defects.

Adipose-derived stromal vascular fraction injection following core decompression and biochemistry artificial bone graft implantation in osteonecrosis of the femoral head

PURPOSE

To determine how adipose-derived stromal vascular fraction (SVF) injection following core decompression (CD) and biochemistry artificial bone graft implantation affects outcomes in patients with osteonecrosis of the femoral head (ONFH).

METHODS

A total of 19 patients (28 hips) with stage I-IIIA ONFH received adipose-derived SVF injection and combined core decompression and biochemistry artificial bone graft implantation, followed up for a minimum of two years. Disease progression was evaluated according to the Association Research Circulation Osseous (ARCO) staging system, and the change of the ratio of the necrotic volume to femoral head volume was calculated with MRI before and after operation.

RESULTS

At the last follow-up, 15 hips remained stable, and 13 hips had a progression, according to the ARCO staging system. A total of eight hips (5 with ARCO stage II and 3 with staged IIIA at baseline) progressed to post-collapse stage (stage IIIB-IV). In total, seven of eight hips with post-collapse stage and one with IIIA stage at follow-up converted to THAs in an average of 17.5 months (range, 11-68 months) postoperatively. The mean ratio of the necrotic lesion volume to the femoral head significantly decreased in hips with ARCO stage I (17.9 ± 3.0% to 9.8 ± 1.3%, p = 0.012, Δ necrosis ratio = 8.1 ± 4.2%) and stage II (22.7 ± 6.3% to 17.1 ± 9.4%, p = 0.001, Δ necrosis ratio = 5.7 ± 6.6%) at baseline. For the eight hips that progressed to post-collapse stage, the mean necrosis ratio increased from 27.4 ± 5.4% to 31.1 ± 4.0% (p = 0.146), Δ necrosis ratio =  - 3.7 ± 3.9%. For the other 20 hips radiological survived, the mean necrosis ratio improved from 19.9 ± 4.4% to 11.8 ± 3.3% (p < 0.001), with Δ necrosis ratio = 8.1 ± 4.9%.

CONCLUSION

Adipose-derived SVF injection following core decompression and biochemistry artificial bone graft implantation is safe and could effectively repair the necrosis lesion and delay disease progression in patients with early-stage ONFH.

The Applications and Potentials of Extracellular Vesicles from Different Cell Sources in Periodontal Regeneration

Periodontitis is a chronic infectious disease worldwide that can cause damage to periodontal supporting tissues including gingiva, bone, cementum and periodontal ligament (PDL). The principle for the treatment of periodontitis is to control the inflammatory process. Achieving structural and functional regeneration of periodontal tissues is also essential and remains a major challenge. Though many technologies, products, and ingredients were applied in periodontal regeneration, most of the strategies have limited outcomes. Extracellular vesicles (EVs) are membranous particles with a lipid structure secreted by cells, containing a large number of biomolecules for the communication between cells. Numerous studies have demonstrated the beneficial effects of stem cell-derived EVs (SCEVs) and immune cell-derived EVs (ICEVs) on periodontal regeneration, which may be an alternative strategy for cell-based periodontal regeneration. The production of EVs is highly conserved among humans, bacteria and plants. In addition to eukaryocyte-derived EVs (CEVs), a growing body of literature suggests that bacterial/plant-derived EVs (BEVs/PEVs) also play an important role in periodontal homeostasis and regeneration. The purpose of this review is to introduce and summarize the potential therapeutic values of BEVs, CEVs and PEVs in periodontal regeneration, and discuss the current challenges and prospects for EV-based periodontal regeneration.

Exosomes Derived from Adipose Stem Cells Enhance Bone Fracture Healing via the Activation of the Wnt3a/β-Catenin Signaling Pathway in Rats with Type 2 Diabetes Mellitus

Nonunion and delayed union are common complications of diabetes mellitus that pose a serious health threat to people. There are many approaches that have been used to improve bone fracture healing. Recently, exosomes have been regarded as promising medical biomaterials for improving fracture healing. However, whether exosomes derived from adipose stem cells can promote bone fracture healing in diabetes mellitus remains unclear. In this study, adipose stem cells (ASCs) and exosomes derived from adipose stem cells (ASCs-exos) are isolated and identified. Additionally, we evaluate the in vitro and in vivo effects of ASCs-exos on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and bone repair and the regeneration in a rat model of nonunion via Western blotting, immunofluorescence assay, ALP staining, alizarin red staining, radiographic examination and histological analysis. Compared with controls, ASCs-exos promoted BMSC osteogenic differentiation. Additionally, the results of Western blotting, radiographic examination and histological analysis show that ASCs-exos improve the ability for fracture repair in the rat model of nonunion bone fracture healing. Moreover, our results further proved that ASCs-exos play a role in activating the Wnt3a/β-catenin signaling pathway, which facilitates the osteogenic differentiation of BMSCs. All these results show that ASCs-exos enhance the osteogenic potential of BMSCs by activating the Wnt/β-catenin signaling pathway, and also facilitate the ability for bone repair and regeneration in vivo, which provides a novel direction for fracture nonunion in diabetes mellitus treatment.

Update on the Role of Glucocorticoid Signaling in Osteoblasts and Bone Marrow Adipocytes During Aging

PURPOSE OF REVIEW

Bone marrow adipose tissue (BMAT) in the skeleton likely plays a variety of physiological and pathophysiological roles that are not yet fully understood. In elucidating the complex relationship between bone and BMAT, glucocorticoids (GCs) are positioned to play a key role, as they have been implicated in the differentiation of bone marrow mesenchymal stem cells (BMSCs) between osteogenic and adipogenic lineages. The purpose of this review is to illuminate aspects of both endogenous and exogenous GC signaling, including the influence of GC receptors, in mechanisms of bone aging including relationships to BMAT.

RECENT FINDINGS

Harmful effects of GCs on bone mass involve several cellular pathways and events that can include BMSC differentiation bias toward adipogenesis and the influence of mature BMAT on bone remodeling through crosstalk. Interestingly, BMAT involvement remains poorly explored in GC-induced osteoporosis and warrants further investigation. This review provides an update on the current understanding of the role of glucocorticoids in the biology of osteoblasts and bone marrow adipocytes (BMAds).

Engineering exosomes for bone defect repair

Currently, bone defect repair is still an intractable clinical problem. Numerous treatments have been performed, but their clinical results are unsatisfactory. As a key element of cell-free therapy, exosome is becoming a promising tool of bone regeneration in recent decades, because of its promoting osteogenesis and osteogenic differentiation function in vivo and in vitro. However, low yield, weak activity, inefficient targeting ability, and unpredictable side effects of natural exosomes have limited the clinical application. To overcome the weakness, various approaches have been applied to produce engineering exosomes by regulating their production and function at present. In this review, we will focus on the engineering exosomes for bone defect repair. By summarizing the exosomal cargos affecting osteogenesis, the strategies of engineering exosomes and properties of exosome-integrated biomaterials, this work will provide novel insights into exploring advanced engineering exosome-based cell-free therapy for bone defect repair.

MicroRNA-loaded biomaterials for osteogenesis

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

Emerging role of non-coding RNAs in the regulation of Sonic Hedgehog signaling pathway

Sonic Hedgehog (Shh) signaling cascade is one of the complex signaling pathways that control the accurately organized developmental processes in multicellular organisms. This pathway has fundamental roles in the tumor formation and induction of resistance to conventional therapies. Numerous non-coding RNAs (ncRNAs) have been found to interact with Shh pathway to induce several pathogenic processes, including malignant and non-malignant disorders. Many of the Shh-interacting ncRNAs are oncogenes whose expressions have been increased in diverse malignancies. A number of Shh-targeting miRNAs such as miR-26a, miR-1471, miR-129-5p, miR-361-3p, miR-26b-5p and miR-361-3p have been found to be down-regulated in tumor tissues. In addition to malignant conditions, Shh-interacting ncRNAs can affect tissue regeneration and development of neurodegenerative disorders. XIST, LOC101930370, lncRNA-Hh, circBCBM1, SNHG6, LINC‐PINT, TUG1 and LINC01426 are among long non-coding RNAs/circular RNAs that interact with Shh pathway. Moreover, miR-424, miR-26a, miR-1471, miR-125a, miR-210, miR-130a-5p, miR-199b, miR-155, let-7, miR-30c, miR-326, miR-26b-5p, miR-9, miR-132, miR-146a and miR-425-5p are among Shh-interacting miRNAs. The current review summarizes the interactions between ncRNAs and Shh in these contexts.

Therapeutic perspectives of exosomes in glucocorticoid-induced osteoarthrosis

Exosomes are widely involved in a variety of physiological and pathological processes. These important roles are also hidden in the physiological processes related to bone. Chondrocytes, osteoblasts, synovial fibroblasts, and bone marrow mesenchymal stem cells produce and secrete exosomes, thereby affecting the biology process of target cells. Furthermore, in the primary pathogenesis of osteoarthrosis induced by steroid hormones, mainly involve glucocorticoid (GC), the exosomes have also widely participated. Therefore, exosomes may also play an important role in glucocorticoid-induced osteoarthrosis and serve as a promising treatment for early intervention of osteoarthrosis in addition to playing a regulatory role in malignant tumors. This review summarizes the previous results on this direction, systematically combs the role and therapeutic potential of exosomes in GC-induced osteoarthrosis, discusses the potential role of exosomes in the treatment and prevention of GC-induced osteoarthrosis, and reveals the current challenges we confronted.

Infarct-preconditioning exosomes of umbilical cord mesenchymal stem cells promoted vascular remodeling and neurological recovery after stroke in rats

Background

Stroke is the leading cause of disability worldwide, resulting in severe damage to the central nervous system and disrupting neurological functions. There is no effective therapy for promoting neurological recovery. Growing evidence suggests that the composition of exosomes from different microenvironments may benefit stroke. Therefore, it is reasonable to assume that exosomes secreted in response to infarction microenvironment could have further therapeutic effects.

Methods

In our study, cerebral infarct tissue extracts were used to pretreat umbilical cord mesenchymal stem cells (UCMSC). Infarct-preconditioned exosomes were injected into rats via tail vein after middle cerebral artery occlusion (MCAO). The effect of infarct-preconditioned exosomes on the neurological recovery of rats was examined using Tunel assay, 2,3,5-triphenyltetrazolium chloride (TTC) assay, magnetic resonance imaging (MRI) analyses, modified Neurological Severity Score (mNSS), Morris water maze (MWM), and vascular remodeling analysis. Mi-RNA sequencing and functional enrichment analysis were used to validate the signal pathway involved in the effect of infarct-preconditioned exosomes. Human umbilical vein endothelial cells (HUVECs) were co-cultured with the isolated exosomes. Cell Counting Kit-8 (CCK-8) assay, scratch healing, and Western blot analysis were used to detect the biological behavior of HUVECs.

Results

The results showed that compared with normal exosomes, infarct-preconditioned exosomes further promoted vascular remodeling and recovery of neurological function after stroke. The function of upregulated miRNAs and their target genes which is beneficial to vascular smooth muscle cells verified the importance of vascular remodeling in improving stroke. Better resistance to oxygen–glucose deprivation/reoxygenation (OGD/R), reduced apoptosis, and enhanced migration were observed in infarct-preconditioned exosomes-treated umbilical vein endothelial cells.

Conclusions

Our results demonstrated that infarct-preconditioned exosomes promoted neurological recovery after stroke by enhancing vascular endothelial remodeling, suggested that infarct-preconditioned exosomes could be a novel way to alleviate brain damage following a stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03083-9.

Application of exosome-derived noncoding RNAs in bone regeneration: Opportunities and challenges

With advances in the fields of regenerative medicine, cell-free therapy has received increased attention. Exosomes have a variety of endogenous properties that provide stability for molecular transport across biological barriers to cells, as a form of cell-to-cell communication that regulates function and phenotype. In addition, exosomes are an important component of paracrine signaling in stem-cell-based therapy and can be used as a stand-alone therapy or as a drug delivery system. The remarkable potential of exosomes has paved the pathway for cell-free treatment in bone regeneration. Exosomes are enriched in distinct noncoding RNAs (ncRNAs), including microRNAs, long ncRNAs and circular RNAs. Different ncRNAs have multiple functions. Altered expression of ncRNA in exosomes is associated with the regenerative potential and development of various diseases, such as femoral head osteonecrosis, myocardial infarction, and cancer. Although there is increasing evidence that exosome-derived ncRNAs (exo-ncRNAs) have the potential for bone regeneration, the detailed mechanisms are not fully understood. Here, we review the biogenesis of exo-ncRNA and the effects of ncRNAs on angiogenesis and osteoblast- and osteoclast-related pathways in different diseases. However, there are still many unsolved problems and challenges in the clinical application of ncRNA; for instance, production, storage, targeted delivery and therapeutic potency assessment. Advancements in exo-ncRNA methods and design will promote the development of therapeutics, revolutionizing the present landscape.

Autocrine Activity of Extracellular Vesicles Induced by Icariin and Its Effectiveness in Glucocorticoid-Induced Injury of Bone Microvascular Endothelial Cells

Glucocorticoids could induce injury and apoptosis of bone microvascular endothelial cells (BMECs) in the femoral head, which is associated with the development of osteonecrosis and osteoporosis. Icariin is a prenylated flavonol glycoside isolated from Epimedium brevicornum, serving as the main active pharmaceutical constituent to treat bone loss. Currently, the impact of the autocrine activity of extracellular vesicles (EVs) induced by icariin on the glucocorticoid-induced injury of BMECs is still to be confirmed. In this study, EVs were isolated from BMECs treated with and without icariin by super-speed centrifugation. Although icariin treatment would not significantly change the size and total protein content of BMECs-derived EVs, expression of EVs-carried vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1) was enhanced and numerous miRNAs involved in cell proliferation and apoptosis were upregulated (e.g., hsa-miR-1469 and hsa-miR-133a-5p) or downregulated (e.g., hsa-miR-10b-5p) (p < 0.05). A total of 29 differentially expressed inflammatory factors were detected between the EVs secreted by BMECs from the Icariin-treated group and the Model group. The EVs secreted by BMECs could improve cell viability, decrease cell apoptosis, and promote cell migration and angiogenesis under the intervention of glucocorticoids. Meanwhile, icariin intervention could reinforce these protective effects of BMECs-derived EVs. To sum up, the present study indicates that icariin acts as a promising candidate for treating glucocorticoid-induced injury of BMECs and bone diseases, partially through the autocrine activity of EVs. In vivo or animal studies are still required to better understand the function of BMECs-derived EVs.

Caffeic acid dimethyl ether alleviates alcohol-induced hepatic steatosis via microRNA-378b-mediated CaMKK2-AMPK pathway

Alcoholic liver disease (ALD), with its increasing morbidity and mortality, has seriously and extensively affected the health of people worldwide. Caffeic Acid Dimethyl Ether (CADE) significantly inhibits alcohol-induced hepatic steatosis in vivo through AMP-activated protein kinase (AMPK) pathway, but its in-depth mechanism remains unclear. This work aimed to clarify further mechanism of CADE in improving hepatic lipid accumulation in ALD through the microRNA-378b (miR-378b)-mediated Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2)-AMPK signaling pathway. Here, we reported that the hepatic or serum triglyceride (TG), total cholesterol (TC), alanine aminotransferase (ALT), and aspartate transaminase (AST) levels were sharply escalated by ethanol while prominently decreased by CADE. Ethanol sharply up-regulated miR-378b expression while CADE effectively prevented the elevation of miR-378b in vivo. And treatment of CADE surely increased mRNA and protein expression of CaMKK2 as a kinase of AMPK and reduced lipid accumulation in the livers of alcohol-fed C57BL/6 mice. MiR-378b escalation exacerbated hepatic steatosis and inhibited CaMKK2-AMPK signaling, while miR-378b deficiency alleviated lipid accumulation and activated the CaMKK2 cascade. Furthermore, CADE alleviated the lipid deposition and reversed the disorder of CaMKK2-AMPK signaling pathway induced by miR-378b over-expression. However, knockdown of miR-378b eliminated the beneficial effect of CADE on lipid metabolism. In brief, our results showed that CADE ultimately improved hepatic lipid deposition by regulating the CaMKK2-AMPK signaling pathway through miR-378b.

The analysis of Modified Qing' E Formula on the differential expression of exosomal miRNAs in the femoral head bone tissue of mice with steroid-induced ischemic necrosis of femoral head

OBJECTIVE

To investigate the differential expression of exosomal miRNAs in the bone marrow tissue of Modified Qing' E Formula (MQEF) on steroid-induced ischemic necrosis of the femoral head (INFH) model.

METHODS

Steroid hormones were used to establish the INFH model and treated with MQEF. After successful modeling, femoral tissue exosomes were isolated for miRNA sequencing to obtain femoral tissue exosomal differential miRNAs. By GO analysis and KEGG analysis of the differential genes in both groups, the major exosomal miRNAs of MQEF exerting anti-INFH as well as the major signaling pathways were identified. Next, a quantitative metabolomic validation of MQEF with broad targeting was performed to obtain the main active components of MQEF and to perform biological analysis and signaling pathway prediction of the active components by network pharmacology. Finally, the sequencing results were validated by using RT-qPCR. The results of miRNA sequencing were verified by double examination of network pharmacology and RT-qPCR, and the exosomal miRNAs regulated by the anti-INFH effect of MQEF and the specific signaling pathway of the effect were clarified.

RESULTS

A total of 65,389 target genes were predicted in the exosomes of two groups of mice, and 18 significant differentially expressed miRNAs were obtained, of which 14 were up-regulated and 4 down-regulated. GO enrichment analysis showed that these predicted target genes were enriched in 12371 biological processes, 1727 cell components, and 4112 molecular functions. KEGG analysis showed that the predicted miRNA target genes were annotated to 342 signal pathways, in which the highly enriched pathways closely related to bone metabolism were PI3K-Akt signal pathway, MAPK signal pathway, and Wnt signal pathway. The most significantly up-regulated miRNAs were miR-185-3p and miR-1b-5p and the most significantly down-regulated miRNAs were miR-129b-5p and miR-223-5p, of which the targeted genes were closely related to the PI3K-Akt signal pathway. MQEF aqueous decoction extract targeted metabolomics quantitatively combined with network pharmacology predicted targets also closely related to PI3K-Akt signaling pathway. Real-time quantitative PCR validation showed that miR-185-3p was up-regulated 7.2-fold and miR-129b-5p was down-regulated 2.2-fold in the treatment group, and the difference was significant (P < 0.05).

CONCLUSIONS

MQEF can regulate exosomal miRNA expression in steroid-induced INFH models, miR-185-3p or miR-129b-5p/PI3K-Akt signal axis may be part of the mechanism of MQEF against steroid-induced INFH.