Comprehensive analysis of M2 macrophage-derived exosomes facilitating osteogenic differentiation of human periodontal ligament stem cells

Exosomes secreted from M2-polarized macrophages inhibit osteoclast differentiation via CYLD

OBJECTIVE

Bone resorption mediated by osteoclast differentiation induces the occurrence of bone-related diseases. Macrophages, an origin of osteoclasts, whose M2 type can reduce inflammation-induced bone damage. We aimed to investigate the effect of M2 macrophage-derived exosomes on osteoclast formation and elucidate its underlying mechanism.

MATERIALS AND METHODS

Exosomes were isolated from M2 macrophages (M2-exo) and were used to treat osteoclast-like cells. Osteoclast formation was evaluated using tartrate-resistant acid phosphatase, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. The molecular mechanism of M2-exo function was analyzed by qRT-PCR, phosphor-kinase array analysis, and Western blotting.

RESULTS

M2-exo was internalized by osteoclasts and inhibited osteoclast differentiation in vitro. Moreover, CYLD was highly expressed in M2 macrophages and M2-exo-treated osteoclasts, and knockdown of it abrogated the inhibition of osteoclast differentiation caused by M2-exo. Additionally, CYLD suppressed the phosphorylation of STAT3, and STAT3 activator colivelin reversed the inhibition of osteoclast differentiation induced by CYLD overexpression.

CONCLUSION

M2-exo inhibits osteoclast differentiation via delivering CYLD, which inactivates STAT3 signaling. These findings may provide a novel therapeutic option for bone diseases including periodontitis.

Ginsenoside RB1 Influences Macrophage-DPSC Interactions in Inflammatory Conditions

INTRODUCTION AND AIMS

Unresolved inflammation and tissue destruction are supposed to underlie the failure of dental pulp repair. As crucial regulators of the injury response, dental pulp stem cells (DPSCs) play a key role in pulp tissue repair and regeneration. M2 macrophages have been demonstrated to induce osteogenic/odontogenic differentiation of DPSCs. Ginsenoside Rb1 (GRb1) is the major component of ginseng and manifested an anti-inflammatory role by promoting M1 macrophage polarised into M2 macrophage in inflammatory disease. However, whether GRb1 facilitates odontogenic differentiation of DPSCs via promoting M2 macrophage polarisation under inflammatory conditions has yet to be established.

METHODS

Human monocyte leukemic cells (THP-1) differentiated macrophages were induced into M1 subsets and then treated with GRb1. After that, the conditioned medium was added to DPSCs. The cell co-cultured system was then subjected to odontogenic differentiation in osteogenic media. Effects of GRb1 on human dental pulp stem cells' (hDPSCs') osteogenic/odontogenic differentiation under inflammatory conditions were assessed by alkaline phosphatase (ALP) staining, Alizarin Red S (ARS) staining, and quantitative polymerase chain reaction testing.

RESULTS

Results demonstrated that GRb1 could facilitate the polarisation of macrophages from the M1 subtype to the M2 subtype. Conditioned medium from GRb1 + M1 macrophages, in comparison with M1 macrophages, may markedly increase the gene expression of ALP, DSPP, and DMP1. Moreover, ALP and ARS staining uncovered that the osteogenic/odontogenic differentiation ability of hDPSCs was strengthened in the M1 + GRb1 co-culture group.

CONCLUSIONS

GRb1 plays a crucial role in the inflammatory response and reparative dentine formation after dental pulp injury. Findings show that GRb1 modulates the interaction between macrophages and DPSCs during inflammation. The current study discusses modifications of deep caries therapy.

Enhanced osteogenic differentiation of human periodontal ligament cells by mature osteoclasts

OBJECTIVE

Several in vitro studies have shown that reverse signaling from osteoclasts regulates osteoblast differentiation and mineralization. However, none of these studies have reported the effects of this signaling pathway on periodontal ligament (PDL) cells. Therefore, in this study, we aimed to investigate the interaction between receptor activators of nuclear factor kappa B (RANK) released from mature human osteoclasts and the membranous RANK ligand (RANKL) in human PDL cells.

METHODS

Multinucleated mature human osteoclasts were differentiated from peripheral blood mononuclear cells upon incubation with recombinant macrophage colony-stimulating factor and RANKL. Mature osteoclasts and human PDL cells were characterized. A mature osteoclast-conditioned medium (OC-CM) was used to induce osteogenic differentiation of PDL cells. Mechanistic analysis of RANK-RANKL reverse signaling were conducted to determine the regulation of osteogenic induction using conditioned medium from mature osteoclasts treated with GW4869 (GW-OC-CM) or PDL cells pretreated with recombinant human osteoprotegerin (OPG).

RESULTS

OC-CM significantly upregulated the mRNA expression of osteogenic genes and enhanced the osteogenic differentiation and biomineralization of PDL cells (p < 0.05). GW-OC-CM significantly reduced the expression of osteogenic genes, osteogenic differentiation, and biomineralization in PDL cells (p < 0.05). Similarly, the pretreatment of PDL cells with OPG before OC-CM treatment significantly reduced the osteogenic induction of PDL cells (p < 0.05).

CONCLUSION

Mature osteoclasts can induce osteogenesis in human PDL cells via RANK-RANKL reverse signaling.

Macrophage-derived extracellular vesicles as new players in chronic non-communicable diseases

Macrophages are innate immune cells present in all tissues and play an important role in almost all aspects of the biology of living organisms. Extracellular vesicles (EVs) are released by cells and transport their contents (micro RNAs, mRNA, proteins, and long noncoding RNAs) to nearby or distant cells for cell-to-cell communication. Numerous studies have shown that macrophage-derived extracellular vesicles (M-EVs) and their contents play an important role in a variety of diseases and show great potential as biomarkers, therapeutics, and drug delivery vehicles for diseases. This article reviews the biological functions and mechanisms of M-EVs and their contents in chronic non-communicable diseases such as cardiovascular diseases, metabolic diseases, cancer, inflammatory diseases and bone-related diseases. In addition, the potential application of M-EVs as drug delivery systems for various diseases have been summarized.

Microbial- and host immune cell-derived extracellular vesicles in the pathogenesis and therapy of periodontitis: A narrative review

Periodontitis is a chronic inflammatory disease caused by dysbiotic biofilms and destructive host immune responses. Extracellular vesicles (EVs) are circulating nanoparticles released by microbes and host cells involved in cell-to-cell communication, found in body biofluids, such as saliva and gingival crevicular fluid (GCF). EVs are mainly involved in cell-to-cell communication, and may hold promise for diagnostic and therapeutic purposes. Periodontal research has examined the potential involvement of bacterial- and host-cell-derived EVs in disease pathogenesis, diagnosis, and therapy, but data remains scarce on immune cell- or microbial-derived EVs. In this narrative review, we first provide an overview of the role of microbial and host-derived EVs on disease pathogenesis. Recent studies reveal that Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans-derived outer membrane vesicles (OMVs) can activate inflammatory cytokine release in host cells, while M1 macrophage EVs may contribute to bone loss. Additionally, we summarised current in vitro and pre-clinical research on the utilisation of immune cell and microbial-derived EVs as potential therapeutic tools in the context of periodontal treatment. Studies indicate that EVs from M2 macrophages and dendritic cells promote bone regeneration in animal models. While bacterial EVs remain underexplored for periodontal therapy, preliminary research suggests that P. gingivalis OMVs hold promise as vaccine candidates. Finally, we acknowledge the current limitations present in the field of translating immune cell derived EVs and microbial derived EVs in periodontology. It is concluded that microbial and host immune cell-derived EVs have a role in periodontitis pathogenesis and hence may be useful for studying disease pathophysiology, and as diagnostic and treatment monitoring biomarkers.

M2 macrophage-derived exosomes for bone regeneration: A systematic review

OBJECTIVE

This systematic review aims to evaluate existing evidence to investigate the therapeutic efficacy of M2 macrophage-derived exosomes in bone regeneration.

DESIGN

A comprehensive search between 2020 and 2024 across PubMed, Web of Science, and Scopus was conducted using a defined search strategy to identify relevant studies regarding the following question: "What is the impact of M2 macrophage-derived exosomes on bone regeneration?". Controlled in vitro and in vivo studies were included in this study. The SYRCLE tool was used to evaluate the risk of bias in the included animal studies.

RESULTS

This review included 20 studies published. Seven studies were selected for only in vitro analysis, whereas 13 studies underwent both in vitro and in vivo analyses. The in vivo studies employed animal models, including 163 C57BL6 mice and 73 Sprague-Dawley rats. Exosomes derived from M2 macrophages were discovered to be efficacious in promoting bone regeneration and vascularization in animal models of bone defects. These effects were primarily confirmed through morphological and histological assessments. This remarkable outcome is attributed to the regulation of multiple signaling pathways, as evidenced by the findings of 11 studies investigating the involvement of miRNAs in this intricate process. In addition, in vitro studies observed positive effects on cell proliferation, migration, osteogenesis, and angiogenesis. Heterogeneity in study methods hinders direct comparison of results across studies.

CONCLUSION

M2 macrophage-derived exosomes demonstrate remarkable potential for promoting bone regeneration. Further research optimizing their application and elucidating the underlying mechanisms can pave the way for clinical translation.

Integrated bioinformatic analysis of protein landscape in gingival crevicular fluid unveils sequential bioprocess in orthodontic tooth movement

BACKGROUND

The biological mechanisms driving orthodontic tooth movement (OTM) remain incompletely understood. Gingival crevicular fluid (GCF) is an important indicator of the periodontal bioprocess, providing valuable cues for probing the molecular mechanisms of OTM.

METHODS

A rigorous review of the clinical studies over the past decade was conducted after registering the protocol with PROSPERO and adhering to inclusion criteria comprising human subjects, specified force magnitudes and force application modes. The thorough screening investigated differentially expressed proteins (DEPs) in GCF associated with OTM. Protein-protein interaction (PPI) analysis was carried out using the STRING database, followed by further refinement through Cytoscape to isolate top hub proteins.

RESULTS

A comprehensive summarization of the OTM-related GCF studies was conducted, followed by an in-depth exploration of biomarkers within the GCF. We identified 13 DEPs, including ALP, IL-1β, IL-6, Leptin, MMP-1, MMP-3, MMP-8, MMP-9, PGE2, TGF-β1, TNF-α, OPG, RANKL. Bioinformatic analysis spotlighted the top 10 hub proteins and their interactions involved in OTM. Based on these findings, we have proposed a hypothetic diagram for the time-course bioprocess in OTM, which involves three phases containing sequential cellular and molecular components and their interplay network.

CONCLUSIONS

This work has further improved our understanding to the bioprocess of OTM, suggesting biomarkers as potential modulating targets to enhance OTM, mitigate adverse effects and support real-time monitoring and personalized orthodontic cycles.

M2 macrophage-derived exosomes enable osteogenic differentiation and inhibit inflammation in human periodontal ligament stem cells through promotion of CXCL12 expression

BACKGROUND

Periodontitis is a dental disease characterized by inflammation of periodontal tissues and loss of the periodontal ligaments and alveolar bone. Exosomes are a class of extracellular vesicles that are involved in a variety of diseases by releasing active substances. In this study, we aimed to investigate the effect and mechanism of exosomes from M2 polarized macrophages (M2-exos) on osteogenic differentiation in human periodontal ligament stem cells (hPDLSCs).

METHODS

M2-exos were isolated from IL-4-induced RAW264.7 cells (M2 macrophages) and then treated on hPDLSCs. Osteogenic differentiation was assessed by alkaline phosphatase (ALP) staining, alizarin red S (ARS) staining, measurement of osteogenic differentiation-related genes and proteins, and inflammation was evaluated by measuring the levels of inflammatory factors. The mechanism of M2-exo was confirmed through qPCR, western blot, ALP and ARS staining.

RESULTS

Results suggested that M2-exo improved osteogenic differentiation and inhibited inflammation in LPS-induced hPDLSCs. CXCL12 expression was elevated in M2 macrophages, but decreased in LPS-induced hPDLSCs. Moreover, the effect of M2-exo on osteogenic differentiation and inflammation in LPS-induced hPDLSCs was reversed by CXCL12 knockdown.

CONCLUSION

We demonstrated that M2-exo facilitated osteogenic differentiation and suppressed inflammation in LPS-induced hPDLSCs through promotion of CXCL12 expression. These results suggested the potential of M2-exo in the treatment of periodontitis, which may provide a new theoretical basis for M2-exo treatment of periodontitis.

Non-coding RNAs Function in Periodontal Ligament Stem Cells

Non-coding RNA has many types which has rich functions and plays an important role in the study of basic molecular mechanisms. Many non-coding RNA have important implications for pluripotent stem cells and embryonic stem cells. It has been found to affect the self-renewal and osteogenesis of many types of stem cells. They have also been found to regulate stem cell proliferation and induct bone differentiation. Periodontal ligament stem cells are essential for the regeneration of periodontal tissue. In recent years, in the field of stomatology, studies have found that many non-coding RNA also have significant regulatory effects on the proliferation and differentiation of periodontal stem cells and may become potential therapeutic targets for many common periodontal diseases such as periodontitis, bone/tooth/soft tissue loss and orthodontic treatment. Therefore, we summarized the current research status of non-coding RNA in the field of molecular mechanism of periodontal ligament stem cells and prospected its future progress.

A new direction in periodontitis treatment: biomaterial-mediated macrophage immunotherapy

Periodontitis is a chronic inflammation caused by a bacterial infection and is intimately associated with an overactive immune response. Biomaterials are being utilized more frequently in periodontal therapy due to their designability and unique drug delivery system. However, local and systemic immune response reactions driven by the implantation of biomaterials could result in inflammation, tissue damage, and fibrosis, which could end up with the failure of the implantation. Therefore, immunological adjustment of biomaterials through precise design can reduce the host reaction while eliminating the periodontal tissue's long-term chronic inflammation response. It is important to note that macrophages are an active immune system component that can participate in the progression of periodontal disease through intricate polarization mechanisms. And modulating macrophage polarization by designing biomaterials has emerged as a new periodontal therapy technique. In this review, we discuss the role of macrophages in periodontitis and typical strategies for polarizing macrophages with biomaterials. Subsequently, we discuss the challenges and potential opportunities of using biomaterials to manipulate periodontal macrophages to facilitate periodontal regeneration.

Osteo-immunomodulatory effects of macrophage-derived extracellular vesicles treated with biphasic calcium phosphate ceramics on bone regeneration

Literature on osteoimmunology has demonstrated that macrophages have a great influence on biomaterial-induced bone formation. However, there are almost no reports clarifying the osteo-immunomodulatory capacity of macrophage-derived extracellular vesicles (EVs). This study comprehensively investigated the effects of EVs derived from macrophages treated with biphasic calcium phosphate (BCP) ceramics (BEVs) on vital events associated with BCP-induced bone formation such as immune response, angiogenesis, and osteogenesis. It was found that compared with EVs derived from macrophages alone (control, CEVs), BEVs preferentially promoted macrophage polarization towards a wound-healing M2 phenotype, enhanced migration, angiogenic differentiation, and tube formation of human umbilical vein endothelial cells, and induced osteogenic differentiation of mesenchymal stem cells. Analysis of 15 differentially expressed microRNAs (DEMs) related to immune, angiogenesis, and osteogenesis suggested that BEVs exhibited good immunomodulatory, pro-angiogenic, and pro-osteogenic abilities, which might be attributed to their specific miRNA cargos. These findings not only deepen our understanding of biomaterial-mediated osteoinduction, but also suggest that EVs derived from biomaterial-treated macrophages hold great promise as therapeutic agents with desired immunomodulatory capacity for bone regeneration.

Age-different BMSCs-derived exosomes accelerate tendon-bone interface healing in rotator cuff tears model

BACKGROUND

Rotator cuff tears (RCTs) are culprit of shoulder pain and dysfunction. Tendon-bone interface (TBI) mal-healing is an essential contributor to retear after RCTs. Consequently, present project was conducted to investigate the role of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes on TBI healing.

METHOD

Young BMSCs (Y-BMSCs) and Aged BMSCs (A-BMSCs) were isolated from Young (3-month-old) and old (24-month-old) SD rats, and their-derived exosomes (A-BMSCs-exo and Y-BMSCs-exo) were identified. RCTs model was established, and A-BMSCs-exo and Y-BMSCs-exo were injected at the rotator cuff using hydrogel as a vehicle. Pathological changes of TBI were observed by HE, Sirius Red and Oil Red O staining. Western blotting and RT-qPCR were applied to assess the expression of extracellular matrix (ECM)-, tendon cell (TCs)-, osteogenic-, tendon-derived stem cell (TDSCs)- and angiogenic-associated proteins and mRNAs in TBI.

RESULT

Y-BMSCs exhibited increased activity, osteogenic and lipogenic abilities than A-BMSCs. After A-BMSCs-exo and Y-BMSCs-exo treatment, TBI displayed massive sharpey's fibers growing along the tendon longitudinally, and a collagen fiber-chondrocyte migration zone forming a typical tendon-noncalcified fibrocartilage-calcified fibrocartilage-bone structure. A-BMSCs-exo and Y-BMSCs-exo significantly upregulated the expression of collagen Col I/II/III, Aggrecan, TNMD, SCX, Runx2, OPN, CD45, Sox2, CD31 and VEGFR2 in TBI. In vitro, A-BMSCs-exo and Y-BMSCs-exo significantly enhanced the activity of TCs and TDSCs, TDSCs stemness, and reduced the osteogenic and lipogenic capacity of TDSCs. The effect of Y-BMSCs-exo was significantly stronger than that of A-BMSCs-exo.

CONCLUSION

BMSCs-derived exosomes facilitate ECM remodeling, osteogenic differentiation, angiogenesis, and stemness of TDSCs, thereby accelerating TBI healing in RCTs, with better outcomes using young individual-derived BMSCs.

Genetically engineered M2-like macrophage-derived exosomes for P. gingivalis-suppressed cementum regeneration: From mechanism to therapy

Cementum, a thin layer of mineralized tissue covering tooth root surface, is recognized as the golden standard in periodontal regeneration. However, current efforts mainly focus on alveolar bone regeneration rather than cementum regeneration, and rarely take Porphyromonas gingivalis (Pg), the keystone pathogen responsible for periodontal tissue destruction, into consideration. Though M2 macrophage-derived exosomes (M2-EXO) show promise in tissue regeneration, the exosome-producing M2 macrophages are induced by exogenous cytokines with transitory and unstable effects, restricting the regeneration potential of M2-EXO. Here, exosomes derived from genetically engineered M2-like macrophages are constructed by silencing of casein kinase 2 interacting protein-1 (Ckip-1), a versatile player involved in various biological processes. Ckip-1 silencing is proved to be an effective gene regulation strategy to obtain permanent M2-like macrophages with mineralization-promoting effect. Further, exosomes derived from Ckip-1-silenced macrophages (sh-Ckip-1-EXO) rescue Pg-suppressed cementoblast mineralization and cementogenesis. Mechanismly, sh-Ckip-1-EXO delivers Let-7f-5p targeting and silencing Ckip-1, a negative regulator also for cementum formation and cementoblast mineralization. More deeply, downregulation of Ckip-1 in cementoblasts by exosomal Let-7f-5p activates PGC-1α-dependent mitochondrial biogenesis. In all, this study provides a new strategy of genetically engineered M2-like macrophage-derived exosomes for cementum regeneration under Pg-dominated inflammation.

Understanding exosomes: Part 3-therapeutic + diagnostic potential in dentistry

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with the ability to communicate with other tissues and cell types over long distances. Their use in regenerative medicine has gained tremendous momentum recently due to their ability to be utilized as therapeutic options for a wide array of various diseases. Over 5000 publications are currently being published on this topic yearly, many of which in the dental space. This extensive review article is the first scoping review aimed at summarizing all therapeutic uses of exosomes in regenerative dentistry. A total of 944 articles were identified as using exosomes in the dental field for either their regenerative/therapeutic potential or for diagnostic purposes derived from the oral cavity. In total, 113 research articles were selected for their regenerative potential (102 in vitro, 60 in vivo, 50 studies included both). Therapeutic exosomes were most commonly derived from dental pulps, periodontal ligament cells, gingival fibroblasts, stem cells from exfoliated deciduous teeth, and the apical papilla which have all been shown to facilitate the regenerative potential of a number of tissues including bone, cementum, the periodontal ligament, nerves, aid in orthodontic tooth movement, and relieve temporomandibular joint disorders, among others. Results demonstrate that the use of exosomes led to positive outcomes in 100% of studies. In the bone field, exosomes were found to perform equally as well or better than rhBMP2 while significantly reducing inflammation. Periodontitis animal models were treated with simple gingival injections of exosomes and benefits were even observed when the exosomes were administered intravenously. Exosomes are much more stable than growth factors and were shown to be far more resistant against degradation by periodontal pathogens found routinely in a periodontitis environment. Comparative studies in the field of periodontal regeneration found better outcomes for exosomes even when compared to their native parent stem cells. In total 47 diagnostic studies revealed a role for salivary/crevicular fluid exosomes for the diagnosis of birth defects, cardiovascular disease, diabetes, gingival recession detection, gingivitis, irritable bowel syndrome, neurodegenerative disease, oral lichen planus, oral squamous cell carcinoma, oropharyngeal cancer detection, orthodontic root resorption, pancreatic cancer, periodontitis, peri-implantitis, Sjögren syndrome, and various systemic diseases. Hence, we characterize the exosomes as possessing "remarkable" potential, serving as a valuable tool for clinicians with significant advantages.

Non-bone-derived exosomes: a new perspective on regulators of bone homeostasis

Accumulating evidence indicates that exosomes help to regulate bone homeostasis. The roles of bone-derived exosomes have been well-described; however, recent studies have shown that some non-bone-derived exosomes have better bone targeting ability than bone-derived exosomes and that their performance as a drug delivery vehicle for regulating bone homeostasis may be better than that of bone-derived exosomes, and the sources of non-bone-derived exosomes are more extensive and can thus be better for clinical needs. Here, we sort non-bone-derived exosomes and describe their composition and biogenesis. Their roles and specific mechanisms in bone homeostasis and bone-related diseases are also discussed. Furthermore, we reveal obstacles to current research and future challenges in the practical application of exosomes, and we provide potential strategies for more effective application of exosomes for the regulation of bone homeostasis and the treatment of bone-related diseases. Video Abstract.

M2 macrophages-derived exosomes regulate osteoclast differentiation by the CSF2/TNF-α axis

BACKGROUND

Osteoclast-mediated bone resorption cause bone loss in several bone diseases. Exosomes have been reported to regulate osteoclast differentiation. M2-polarized macrophages exhibit anti-inflammatory activity. This study aimed to explore the effect of exosomes from M2 polarized macrophages (M2-exos) on osteoclastogenesis and molecular mechanisms.

METHODS

M2-exos were isolated from IL-4-induced Raw264.7 cells (M2 macrophages) and used to treat osteoclasts (RANKL-induced Raw264.7 cells). Osteoclast differentiation was visualized using tartrate resistant acid phosphatase staining. Quantitative real-time PCR (qPCR) was conducted to measure the levels of osteoclastogenesis-related genes. The underlying mechanisms of M2-exos were evaluated using qPCR and western blotting.

RESULTS

M2-exos suppressed osteoclast differentiation induced by RANKL. Additionally, CSF2 was highly expressed in M2 macrophages, and knockdown of CSF2 further enhanced the effects of M2-exos on osteoclast differentiation. Moreover, CSF2 positively regulated TNF-α signaling, which inhibition promoted differentiation of M2-exo-treated osteoclasts.

CONCLUSION

M2-exos inhibited RANKL-induced osteoclast differentiation by downregulating the CSF2 expression through inactivating the TNF-α signaling, suggesting the potential application of exosomes in bone disease therapy.

The Genetic Aspects of Periodontitis Pathogenesis and the Regenerative Properties of Stem Cells

Periodontitis (PD) is a prevalent and chronic inflammatory disease with a complex pathogenesis, and it is associated with the presence of specific pathogens, such as Porphyromonas gingivalis. Dysbiosis and dysregulated immune responses ultimately lead to chronic inflammation as well as tooth and alveolar bone loss. Multiple studies have demonstrated that genetic polymorphisms may increase the susceptibility to PD. Furthermore, gene expression is modulated by various epigenetic mechanisms, such as DNA methylation, histone modifications, or the activity of non-coding RNA. These processes can also be induced by PD-associated pathogens. In this review, we try to summarize the genetic processes that are implicated in the pathogenesis of PD. Furthermore, we discuss the use of these mechanisms in diagnosis and therapeutic purposes. Importantly, novel treatment methods that could promote tissue regeneration are greatly needed in PD. In this paper, we also demonstrate current evidence on the potential use of stem cells and extracellular vesicles to stimulate tissue regeneration and suppress inflammation. The understanding of the molecular mechanisms involved in the pathogenesis of PD, as well as the impact of PD-associated bacteria and stem cells in these processes, may enhance future research and ultimately improve long-term treatment outcomes.

M2 Macrophage-Derived Exosomal lncRNA MIR4435-2HG Promotes Progression of Infantile Hemangiomas by Targeting HNRNPA1

Purpose

Infantile hemangiomas (IHs) are commonly observed benign tumors that can cause serious complications. M2-polarized macrophages in IHs promote disease progression. In this study, we investigated the role of M2 macrophage-derived exosomal lncRNA MIR4435-2HG in IHs.

Patients and Methods

Exosomes derived from M2 polarized macrophages were extracted. Next, using cell co-culture or transfection, we investigated whether M2 polarized macrophage-derived exosomes (M2-exos) can transport MIR4435-2HG to regulate the proliferation, migration, invasion, and angiogenesis of hemangioma-derived endothelial cells (HemECs). RNA-seq and RNA pull-down assays were performed to identify targets and regulatory pathways of MIR4435-2HG. We explored the possible mechanisms through which MIR4435-2HG regulates the biological function of HemECs.

Results

M2-exos significantly enhanced the proliferation, migration, invasion, and angiogenesis of HemECs. Thus, HemECs uptake M2-exos and promote biological functions through the inclusion of MIR4435-2HG. RNA-seq and RNA pull-down experiments confirmed that MIR4435-2HG regulates of HNRNPA1 expression and directly binds to HNRNPA1, consequently affecting the NF-κB signal pathway.

Conclusion

MIR4435-2HG of M2-exos promotes the progression of IHs and enhances the proliferation, migration, invasion, and angiogenesis of HemECs by directly binding to HNRNPA1. This study not only reveals the mechanism of interaction between M2 macrophages and HemECs, but also provides a promising therapeutic target for IHs.

Connection between Radiation-Regulating Functions of Natural Products and miRNAs Targeting Radiomodulation and Exosome Biogenesis

Exosomes are cell-derived membranous structures primarily involved in the delivery of the payload to the recipient cells, and they play central roles in carcinogenesis and metastasis. Radiotherapy is a common cancer treatment that occasionally generates exosomal miRNA-associated modulation to regulate the therapeutic anticancer function and side effects. Combining radiotherapy and natural products may modulate the radioprotective and radiosensitizing responses of non-cancer and cancer cells, but there is a knowledge gap regarding the connection of this combined treatment with exosomal miRNAs and their downstream targets for radiation and exosome biogenesis. This review focuses on radioprotective natural products in terms of their impacts on exosomal miRNAs to target radiation-modulating and exosome biogenesis (secretion and assembly) genes. Several natural products have individually demonstrated radioprotective and miRNA-modulating effects. However, the impact of natural-product-modulated miRNAs on radiation response and exosome biogenesis remains unclear. In this review, by searching through PubMed/Google Scholar, available reports on potential functions that show radioprotection for non-cancer tissues and radiosensitization for cancer among these natural-product-modulated miRNAs were assessed. Next, by accessing the miRNA database (miRDB), the predicted targets of the radiation- and exosome biogenesis-modulating genes from the Gene Ontology database (MGI) were retrieved bioinformatically based on these miRNAs. Moreover, the target-centric analysis showed that several natural products share the same miRNAs and targets to regulate radiation response and exosome biogenesis. As a result, the miRNA-radiomodulation (radioprotection and radiosensitization)-exosome biogenesis axis in regard to natural-product-mediated radiotherapeutic effects is well organized. This review focuses on natural products and their regulating effects on miRNAs to assess the potential impacts of radiomodulation and exosome biogenesis for both the radiosensitization of cancer cells and the radioprotection of non-cancer cells.

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.