AtacAnnoR: a reference-based annotation tool for single cell ATAC-seq data.

Here, we present AtacAnnoR, a two-round annotation method for scATAC-seq data using well-annotated scRNA-seq data as reference. We evaluate AtacAnnoR's performance against six competing methods on 11 benchmark datasets. Our results show that AtacAnnoR achieves the highest mean accuracy and the highest mean balanced accuracy and performs particularly well when unpaired scRNA-seq data are used as the reference. Furthermore, AtacAnnoR implements a 'Combine and Discard' strategy to further improve annotation accuracy when annotations of multiple references are available. AtacAnnoR has been implemented in an R package and can be directly integrated into currently popular scATAC-seq analysis pipelines.

Scramblases and virus infection.

The asymmetric distribution of lipids, maintained by flippases/floppases and scramblases, plays a pivotal role in various physiologic processes. Scramblases are proteins that move phospholipids between the leaflets of the lipid bilayer of the cellular membrane in an energy-independent manner. Recent studies have indicated that viral infection is closely related to cellular lipid distribution. The level and distribution of phosphatidylserine (PtdSer) in cells have been demonstrated to be critical regulators of viral infections. Previous studies have supported that the infection of human immunodeficiency virus (HIV), Zika virus, Ebola virus (EBOV), influenza virus, and dengue fever virus require the externalization of phospholipids mediated by scramblases, which are also involved in the pathogenicity of the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we review the relationship of scramblases with viruses and the potential viral effector proteins that might utilize host scramblases.

scMAGIC: accurately annotating single cells using two rounds of reference-based classification.

Here, we introduce scMAGIC (Single Cell annotation using MArker Genes Identification and two rounds of reference-based Classification [RBC]), a novel method that uses well-annotated single-cell RNA sequencing (scRNA-seq) data as the reference to assist in the classification of query scRNA-seq data. A key innovation in scMAGIC is the introduction of a second-round RBC in which those query cells whose cell identities are confidently validated in the first round are used as a new reference to again classify query cells, therefore eliminating the batch effects between the reference and the query data. scMAGIC significantly outperforms 13 competing RBC methods with their optimal parameter settings across 86 benchmark tests, especially when the cell types in the query dataset are not completely covered by the reference dataset and when there exist significant batch effects between the reference and the query datasets. Moreover, when no reference dataset is available, scMAGIC can annotate query cells with reasonably high accuracy by using an atlas dataset as the reference.

Adaptive responses to mTOR gene targeting in hematopoietic stem cells reveal a proliferative mechanism evasive to mTOR inhibition.

The mechanistic target of rapamycin (mTOR) is a central regulator of cell growth and an attractive anticancer target that integrates diverse signals to control cell proliferation. Previous studies using mTOR inhibitors have shown that mTOR targeting suppresses gene expression and cell proliferation. To date, however, mTOR-targeted therapies in cancer have seen limited efficacy, and one key issue is related to the development of evasive resistance. In this manuscript, through the use of a gene targeting mouse model, we have found that inducible deletion of mTOR in hematopoietic stem cells (HSCs) results in a loss of quiescence and increased proliferation. Adaptive to the mTOR loss, mTOR-/- HSCs increase chromatin accessibility and activate global gene expression, contrary to the effects of short-term inhibition by mTOR inhibitors. Mechanistically, such genomic changes are due to a rewiring and adaptive activation of the ERK/MNK/eIF4E signaling pathway that enhances the protein translation of RNA polymerase II, which in turn leads to increased c-Myc gene expression, allowing the HSCs to thrive despite the loss of a functional mTOR pathway. This adaptive mechanism can also be utilized by leukemia cells undergoing long-term mTOR inhibitor treatment to confer resistance to mTOR drug targeting. The resistance can be counteracted by MNK, CDK9, or c-Myc inhibition. These results provide insights into the physiological role of mTOR in mammalian stem cell regulation and implicate a mechanism of evasive resistance in the context of mTOR targeting.

Exosomes derived from hypoxia-preconditioned mesenchymal stem cells (hypoMSCs-Exo): advantages in disease treatment.

Mesenchymal stem cells (MSCs)-based therapy has been reported to be a potential approach to treat various diseases and the paracrine role might be the underlying mechanism. Exosomes were considered an important part of this paracrine role. It was reported that maintenance of MSCs in hypoxia conditions for a short time has shown to be beneficial for the therapeutic effect of MSCs and MSCs-derived exosomes. In this review, we summarized the recent developments on exosomes derived from hypoxia-preconditioned mesenchymal stem cells (hypoMSCs-Exo), including the characteristics of hypoMSCs-Exo in morphology and contents, diseases in which hypoMSCs-Exo showed more effective, and the cellular and molecular mechanisms that hypoMSCs-Exo showed more effective in disease treatment. Besides, we also discussed the limitations of current studies and the issues that needed to be improved in the application of hypoMSCs-Exo. This review aimed to promote a comprehensive and systematic understanding of this type of exosome with great therapeutic potential.

Efficacy of a 1% malic acid spray for xerostomia treatment: A systematic review and meta-analysis.

OBJECTIVES: To assess the efficacy of topical sialogogue spray containing malic acid 1% for treating xerostomia. METHODS: We searched PubMed, Cochrane Library, Embase, ClinicalTrials.gov and Web of Science databases. Literature search, screening, study selection, data collection, data extraction and assessment of bias risk were independently conducted by two reviewers. The study appraisal was performed by Cochrane Collaboration's tool for assessing bias risk. The systematic review registration number was PROSPERO-CRD42021241322. All statistical analyses were performed using Review Manager version 5.4. RESULTS: Five original articles involving 244 patients with xerostomia who received topical sialogogue spray (malic acid 1%) or placebo for two weeks were included in this review. Based on the questionnaire survey, the topical sialogogue spray (malic acid 1%) improved the symptoms of dry mouth significantly better than the placebo, which was reflected in the Dry Mouth Questionnaire (DMQ), Xerostomia Inventory (XI) and Visual Analogue Scale (VAS) scores. Regarding the increase in unstimulated and stimulated saliva flow rates, the intervention group was also better than the placebo group after a two-week course of treatment. CONCLUSIONS: Although the included studies are limited, our results show that topical sialogogue spray (malic acid 1%) is an effective method for the treatment of xerostomia. Additional randomised controlled trials in the future are needed to provide high-quality evidence of this therapy and to improve clinical practice guidelines.

Dental follicle cells-derived small extracellular vesicles inhibit pathogenicity of Porphyromonas gingivalis.

OBJECTIVE: It aims to explore the effect of dental follicle cells-derived small extracellular vesicles (D-sEVs) with or without lipopolysaccharides (LPS) pretreating on the pathogenicity of Porphyromonas gingivalis (P. gingivalis). METHODS: The antibacterial effects of D-sEV were evaluated by measuring the growth, biofilm formation, gingipains, and type IX secretion system (T9SS) expression of P. gingivalis. And the influence of D-sEV on P. gingivalis adhesion, invasion, cytotoxicity, and host immune response was examined in gingival epithelial cells (GECs). Then P. gingivalis treated with D-sEV was applied to investigate the pathogenicity in experimental periodontitis of mice. RESULTS: It showed that both D-sEV and P. gingivalis LPS-pretreated D-sEV (L-D-sEV) could target P. gingivalis, inhibit their growth and biofilm formation, and hinder the attachment and invasion in GECs, therefore remarkably decreasing P. gingivalis cytotoxicity and the expression of IL-1ß and IL-6 in GECs. In addition, they significantly reduced the expression of P. gingivalis virulence factors (gingipains and T9SS). In vivo, it showed that the bacteria in the gingiva were significantly decreased after sEV treatment. Meanwhile, less bone loss and fewer inflammatory cells infiltration and osteoclast formation in D-sEV and L-D-sEV groups. CONCLUSION: Both D-sEV and L-D-sEV were proven to inhibit the pathogenicity of P. gingivalis and thus prevented the development of periodontitis.

Injectable Xenogeneic Dental Pulp Decellularized Extracellular Matrix Hydrogel Promotes Functional Dental Pulp Regeneration.

The present challenge in dental pulp tissue engineering scaffold materials lies in the development of tissue-specific scaffolds that are conducive to an optimal regenerative microenvironment and capable of accommodating intricate root canal systems. This study utilized porcine dental pulp to derive the decellularized extracellular matrix (dECM) via appropriate decellularization protocols. The resultant dECM was dissolved in an acid pepsin solution to form dECM hydrogels. The analysis encompassed evaluating the microstructure and rheological properties of dECM hydrogels and evaluated their biological properties, including in vitro cell viability, proliferation, migration, tube formation, odontogenic, and neurogenic differentiation. Gelatin methacrylate (GelMA) hydrogel served as the control. Subsequently, hydrogels were injected into treated dentin matrix tubes and transplanted subcutaneously into nude mice to regenerate dental pulp tissue in vivo. The results showed that dECM hydrogels exhibited exceptional injectability and responsiveness to physiological temperature. It supported the survival, odontogenic, and neurogenic differentiation of dental pulp stem cells in a 3D culture setting. Moreover, it exhibited a superior ability to promote cell migration and angiogenesis compared to GelMA hydrogel in vitro. Additionally, the dECM hydrogel demonstrated the capability to regenerate pulp-like tissue with abundant blood vessels and a fully formed odontoblast-like cell layer in vivo. These findings highlight the potential of porcine dental pulp dECM hydrogel as a specialized scaffold material for dental pulp regeneration.

Dental Follicle Stem Cells Promote Periodontal Regeneration through Periostin-Mediated Macrophage Infiltration and Reprogramming in an Inflammatory Microenvironment.

Dental follicle stem cells (DFSCs) have been verified to promote periodontal regeneration in an inflammatory microenvironment. When coping with inflammatory stimulation, DFSCs highly express periostin, a bioactive molecule closely related to periodontal homeostasis. It is worth exploring whether and how periostin plays a role in the promotion of periodontal regeneration by DFSCs. By tracking the fate of DFSCs, it was found that DFSCs significantly contributed to periodontal regeneration in rat periodontal defects while they had a low survival rate. They highly expressed periostin and improved the immune microenvironment in the defect area, especially via the recruitment and reprogramming of macrophages. Silencing periostin attenuated the effects of DFSCs in promoting periodontal regeneration and regulating macrophages. Recombinant human periostin (rhPeriostin) could not only directly promote macrophage reprogramming through the integrin αM/phosphorylated extracellular signal-regulated kinase (p-Erk)/Erk signaling pathway, but it also exhibited the potential to promote periodontal regeneration in rats when loaded in a collagen matrix. These results indicated that periostin is actively involved in the process by which DFSCs promote periodontal regeneration through the regulation of macrophages and is a promising molecular agent to promote periodontal regeneration. This study provides new insight into the mechanism by which DFSCs promote periodontal regeneration and suggests a new approach for periodontal regeneration therapy.

Identification of thermogenesis-related lncRNAs in small extracellular vesicles derived from adipose tissue.

BACKGROUND: Brown adipose tissue (BAT) is considered as a primary location of adaptive thermogenesis and the thermogenic activities of brown adipocytes are also connected to generating heat and counteracting obesity. Recent studies revealed that BAT could secrete certain batokines-like factors especially small extracellular vesicles (sEVs), which contributed to the systemic consequences of BAT activities. As a newly emerging class of mediators, some long non-coding RNAs (lncRNAs) have exhibited metabolic regulatory effects in adipocyte development. However, besides the well-studied lncRNAs, the lncRNAs carried by sEVs derived from brown adipose tissue (sEV-BAT) have not been identified yet.  RESULTS: In this study, we demonstrated that sEV-BAT could induce beige adipocyte differentiation both in ASCs and 3T3-L1 cells, while sEV-WAT had no corresponding effects. The lncRNA microarray assay on sEV-WAT and sEV-BAT revealed a total of 563 types of known lncRNAs were identified to be differentially expressed, among which 232 lncRNAs were upregulated and 331 lncRNAs were downregulated in sEV-BAT. Three novel candidates (AK029592, humanlincRNA1030 and ENSMUST00000152284) were selected for further validation. LncRNA-mRNA network analysis revealed candidate lncRNAs were largely embedded in cellular metabolic pathways. During adipogenic and thermogenic phenotype differentiation in ASCs and 3T3-L1 cells, only the expressions of AK029592 were upregulated. The three lncRNAs were all relatively enriched in brown adipose tissues and brown adipocytes. In different adipocytes, sEV and adipose tissue, the expression of AK029592 and ENSMUST00000152284 were remarkably decreased in obese mice compared to lean mice, while obesity state could not change the expression of humanlincRNA1030. CONCLUSION: Collectively, our profiling study provided a comprehensive catalog for the study of lncRNAs specifically carried by sEV-BAT and indicated the potential regulatory role of certain sEV-BAT lncRNAs in thermogenesis.

Nucleophosmin3 carried by small extracellular vesicles contribute to white adipose tissue browning.

BACKGROUND: Browning of white adipose tissue (WAT) is a particularly appealing target for therapeutics in the treatment of obesity and related metabolic diseases. Although small extracellular vesicles (sEVs) released from adipose tissue (sEVs-AT) have emerged as novel player that regulate systemic metabolism by connecting different organs, the role of specific contents in sEVs-AT played in WAT browning has not been clarified. RESULTS: We revealed Nucleophosmin3 (NPM3), which was mainly transferred by sEVs derived from brown adipose tissue (sEVs-BAT), was served as a batokine that could induce WAT browning by regulating the stability of PRDM16 mRNA. sEVs-BAT enhanced the expressions of browning related genes in 3T3-L1 preadipocytes and WAT while knocking down of NPM3 in BAT impaired sEVs-BAT mediated WAT browning and weight loss in obesity. CONCLUSION: These data provided new insight into the role of NPM3 in regulating the browning of WAT. Our study indicated that a supplement of sEVs-BAT might represent a promising therapeutic strategy to promote thermogenesis and energy expenditure in the future.

Reconstruction of an Extensive Maxillofacial Avulsion Injury Caused by Bear Attack With a Double-Island Anterolateral Thigh Free Flap.

ABSTRACT: Bear attack, a relatively rare cause of maxillofacial trauma, could lead to severe facial deformity as well as functional impairment. A 45-year-old male ranger was attacked by a bear and suffered an extensive maxillofacial avulsion injury, resulting in massive soft tissue loss (17.5 × 10 cm 2 ) on his left temporal-facial region with an intraoral defect (3 × 2 cm 2 ), surrounded by pus and necrotic tissue. Computed tomography revealed a comminuted fracture of the mandible, as well as bone defects in the left zygomatic bone, zygomatic arch, and part of the lateral orbital wall. in contrast with tumor resection, this large defect wound resulting from trauma was an infected wound with extensive loss of soft tissue and bone, which presented many operational challenges. The initial goal was to control local infection and then repair the maxillofacial and intraoral defects simultaneously. The left oral mucosal lining and maxillofacial skin after infection control were repaired by transposition of a double-island anterolateral thigh flap, and the fractured mandible was fixed, achieving primary closure for the reconstruction of large soft and hard tissue injuries in the oral and maxillofacial region. Five months postoperatively, the flap had healed and the patient was satisfied with the profile. This patient demonstrated how a rare severe injury caused by a bear attack was treated by preliminary closure of an extremely large post-traumatic oral and maxillofacial defect. The authors recommend the 1 pedi- cled double-island free anterolateral thigh flap as a worthwhile choice for the reconstruction of complicated oral and maxillofacial tissue defects combined with an intraoral defect. To our knowledge, this is the largest clinical application reported to date of an anterolateral thigh flap (approximately 200 cm 2 ) for a post-traumatic oral and maxillofacial defect.

[Application of Extracellular Vesicles Derived from Vascular Endothelial/Endothelial Progenitor Cells in Tissue Regeneration and Repair].

Extracellular vesicles can be released by almost all types of cells and are important mediators of intercellular signal transmssion. Extracellular vesicles regulate the function and activity of recipient cells by delivering biologically active molecules such as proteins and nucleic acids, which is of great significance in tissue repair and regeneration. According to numerous studies, extracellular vesicles derived from endothelial/endothelial progenitor cells can induce cell proliferation and differentiation, inhibit cell apoptosis, and promote angiogenesis, playing an increasingly important role in regenerative medicine. We reported in this review the latest findings on applying extracellular vesicles derived from endothelial/endothelial progenitor cells in tissue regeneration and repair, and discussed the challenges and future development directions of their application in the field of regenerative medicine.

Vitamin C alleviates the senescence of periodontal ligament stem cells through inhibition of Notch3 during long-term culture.

Periodontal ligament stem cells (PDLSCs), as potential "seed cells" for periodontal tissue repair and regeneration, require to be expanded in vitro for a large scale. Senescence of PDLSCs occurred during long-term culture may compromise the therapeutic effects of PDLSCs. Medium supplements may be useful in antisenescence. However, the effects and mechanisms of vitamin C (Vc) treatment on PDLSCs during long-term culture are still unclear. In this study, we identified that Vc-treated PDLSCs cells maintained a slender morphology, higher growth rate and migration capacity, stemness, and osteogenic differentiation capability during a long-term culture. Moreover, we also identified that Notch3 was significantly upregulated during the cell senescence, and Vc treatment alleviated the senescence of PDLSCs through inhibition of Notch3 during long-term culture. In summary, Vc treatment suppressed PDLSCs senescence by reducing the expression of Notch3 and might be a simple and useful strategy to inhibit cellular senescence during the cell long-term culture.

CircRNA-23525 regulates osteogenic differentiation of adipose-derived mesenchymal stem cells via miR-30a-3p.

Adipose-derived mesenchymal stem cells (ADSCs) are considered to be seed cells in bone tissue engineering and emerging evidence indicates that circular RNAs (circRNAs) function in the osteogenic differentiation of ADSCs. The mechanisms of osteoblastic differentiation of ADSCs from the perspective of circRNA modulation are examined in this study. First, circRNA-23525 was upregulated during osteoblastic differentiation of ADSCs. Second, overexpression of circRNA-23525 increased Runx2, ALP and OCN at both mRNA and protein levels. Alkaline phosphatase (ALP) and Alizarin Red staining indicated a similar tendency. Silencing circRNA-23525 produced the opposite effect. Bioinformatics analysis with luciferase assays confirmed that circRNA-23525 functioned as a sponge for miR-30a-3p. In the osteoblastic differentiation of ADSCs, the dynamic expression of miR-30a-3p and circRNA-23525 resulted in an opposite trend at 3, 7 and 14 days. Overexpression of circRNA-23525 downregulated miR-30a-3p and knockdown of circRNA-23525 promoted the expression of miR-30a-3p. Bioinformatics methods and luciferase assays suggested that miR-30a-3p modulated Runx2 expression by targeting 3'UTR. Knockdown of miR-30a-3p facilitated osteogenesis in ADSCs and enhancing miR-30a-3p interfered with the osteogenic process. Finally, circRNA-23525 overexpression significantly increased Runx2 expression, while co-transfection of miR-30a-3p mimics reversed it. Runx2 expression was decreased in circRNA-23525-knockdown ADSCs but expression was rescued by including the miR-30a-3p inhibitor in the osteoblastic process. ALP activity and mineralized bone matrix confirmed the function of circRNA-23525/miR-30a-3p in osteogenesis. Taken together, the current study demonstrated that circRNA-23525 regulates Runx2 expression via targeting miR-30a-3p and is thus a positive regulator in the osteoblastic differentiation of ADSCs.

Prognostic significance of ARL9 and its methylation in low-grade glioma.

This study aimed to determine the value of ARL9 expression or methylation as a biomarker for LGG survival. We investigated the expression, methylation, prognosis and immune significance of ARL9 through bioinformatics analysis. ARL9 is negatively regulated by ARL9 methylation, leading to its low expression in LGG tissues. Both low ARL9 expression and hypermethylation predicted favorable OS and PFS in LGG patients, according to the TCGA database. Cox regression demonstrated that low ARL9 expression and ARL9 hypermethylation were independent biomarkers for OS. Moreover, three other glioma databases were utilized to verify the prognostic role of ARL9 in LGG, and the similar results were reached. A meta-analysis revealed that low ARL9 expression was closely relevant to better OS. Finally, ARL9 expression exhibited a close correlation with some immune cells, especially CD8+ T cells. ARL9 could constitute a promising prognostic biomarker, and probably plays an important role in immune cell infiltration in LGG.

Identification of Novel Adipokines through Proteomic Profiling of Small Extracellular Vesicles Derived from Adipose Tissue.

Adipose tissue is regarded as a true endocrine organ that releases adipokines to regulate distant targets. Besides the well-studied secretory adipokines, the adipokines carried by small extracellular vesicles derived from adipose tissue (sEV-AT) have not been completely characterized yet. In this study, we conducted a complementary protein profiling on sEV-AT with label-free quantitative proteomic analysis (project accession: PXD013270). A total of 2607 sEV-AT proteins were identified, among which 328 proteins had been annotated as adipokines. Three undefined adipokine candidates (NPM3, STEAP3, and DAD1) were selected for further validation. These three proteins were expressed in both white and brown adipose tissues and upregulated during adipogenic differentiation in both 3T3-L1 cells and adipose-derived stromal/stem cells (ASCs). Expressions of NPM3 and DAD1 in sEV-AT were significantly decreased in obese subjects compared with lean controls, while obesity could not alter the expression of STEAP3. Our profiling study of the sEV-AT proteins expanded the list of adipokines and highlighted the pivotal role of adipokines specifically carried by sEVs in the regulation of multiple biological processes within adipose tissue.

Gestational diabetes mellitus affects odontoblastic differentiation of dental papilla cells via Toll-like receptor 4 signaling in offspring.

Gestational diabetes mellitus (GDM) is an important factor involved in the pathogenesis of organ development in the offspring. Here, we analyzed the effects of GDM on odontoblastic differentiation of dental papilla cells (DPCs) and dentin formation in offspring and investigated their underlying mechanisms. A GDM rat model was induced by intraperitoneal injection of streptozotocin and offspring were collected. The results showed that GDM significantly affected odontoblast differentiation and dentin formation in offspring tooth. GDM activated the toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-ĸB) signaling pathway and inhibited SMAD1/5/9 signaling to modulate the odontoblastic differentiation of DPCs in offspring. Inhibition of TLR4 signaling by treated with TAK-242 significantly reverses the suppression of odonto-differentiation of DPCs in diabetic offspring. Taken together, these data indicate GDM activated the offspring DPCs TLR4/NF-ĸB signaling, which suppressed the SMAD1/5/9 phosphorylation and then inhibited odontoblasts differentiation and dentin formation.

Immortalized Hertwig's epithelial root sheath cell line works as model for epithelial-mesenchymal interaction during tooth root formation.

Hertwig's epithelial root sheath (HERS) is critical for epithelial-mesenchymal interaction (EMI) during tooth root formation. However, the exact roles of HERS in odontogenic differentiation by EMI have not been well characterized, because primary HERS cells are difficult to obtain. Immortalized cell lines constitute crucial scientific tools, while there are few HERS cell lines available. Our previous study has successfully established immortalized HERS cell lines. Here, we confirmed the phenotype of our HERS-H1 by verifying its characteristics and functions in odontogenic differentiation through EMI. The HERS-H1-conditioned medium (CM-H1) effectively enhanced odontogenic differentiation of dental papilla cells (DPCs) in vitro. Furthermore, Smad4 and p-Smad1/5/8 were significantly activated in DPCs treated with CM-H1, and this activation was attenuated by noggin. In vivo, our implanted recombinants of HERS-H1 and DPCs exhibited mineralized tissue formation and expression of Smad4, p-Smad1/5/8, and odontogenic differentiation markers. Our results indicated that HERS-H1 promoted DPCs odontoblastic differentiation via bone morphogenetic protein/Smad signaling. HERS-H1 exhibits relevant key molecular characteristics and constitutes a new biological model for basic research on HERS and the dental EMI during root development and regeneration.

Astrocyte-derived exosomes enriched with miR-873a-5p inhibit neuroinflammation via microglia phenotype modulation after traumatic brain injury.

BACKGROUND: The interaction between astrocytes and microglia plays a vital role in the damage and repair of brain lesions due to traumatic brain injury (TBI). Recent studies have shown that exosomes act as potent mediators involved in intercellular communication. METHODS: In the current study, the expression of inflammatory factors and miR-873a-5p in the lesion area and oedema area was evaluated in 15 patients with traumatic brain injury. Exosomes secreted by astrocytes were detected by immunofluorescence, Western blot and electron microscopy. A mouse model of TBI and an in vitro model of LPS-induced primary microglia were established to study the protective mechanism of exosomes from miR-873a-5p overexpressing in TBI-induced nerve injury. RESULTS: We discovered that exosomes derived from activated astrocytes promote microglial M2 phenotype transformation following TBI. More than 100 miRNAs were detected in these astrocyte-derived exosomes. miR-873a-5p is a major component that was highly expressed in human traumatic brain tissue. Moreover, miR-873a-5p significantly inhibited LPS-induced microglial M1 phenotype transformation and the subsequent inflammation through decreased phosphorylation of ERK and NF-κB p65. This effect also greatly improved the modified neurological severity score (mNSS) and attenuated brain injury in a strictly controlled cortical impact mouse model. CONCLUSIONS: Taken together, our research indicates that miRNAs in the exosomes derived from activated astrocytes play a key role in the astrocyte-microglia interaction. miR-873a-5p, as one of the main components of these astrocyte-derived exosomes, attenuated microglia-mediated neuroinflammation and improved neurological deficits following TBI by inhibiting the NF-κB signalling pathway. These findings suggest a potential role for miR-873a-5p in treating traumatic brain injury.