Anaerolentibacter hominis gen. nov. sp. nov., Diplocloster hominis sp. nov. and Pilosibacter fragilis gen. nov. sp. nov., isolated from human faeces.

Three Gram-positive, obligately anaerobic bacterial strains, namely CSJ-1T, CSJ-3T, and CSJ-4T, were isolated from faeces of healthy persons. They were characterized through a combination of whole-genome sequencing, phenotypic traits, and metabolomic analysis. The genome sizes of CSJ-1T, CSJ-4T, and CSJ-3T were 3.3, 3.8, and 6.1 Mbp, with DNA G+C contents of 47.2, 48.3, and 48.8 mol%, respectively. Strain CSJ-3T was identified as representing a novel species, Diplocloster hominis (type strain CSJ-3T=CGMCC 1.18033T=JCM 36512T) of the genus Diplocloster. The 16S rRNA gene sequence similarity and whole genome average nucleotide identity (gANI) of CSJ-4T to its closest related species, Diplocloster modestus ASD 4241T, were 98.3 and 91.4 %, respectively. Comparative analysis of 16S rRNA gene sequences showed 91.6 % similarity between CSJ-1T and its closest phylogenetic neighbour, Catenibacillus scindens DSM 106146T, and 93.3 % similarity between CSJ-4T and its closest relative strain, Clostridium fessum SNUG30386T. Based on the polyphasic taxonomic results, we proposed two novel genera and three novel species. Strain CSJ-1T was identified as representing a novel species of novel genus, Anaerolentibacter hominis gen. nov. sp. nov. (type strain CSJ-1T=CGMCC 1.18046T=JCM 36511T) of the family Lachnospiraceae, and strain CSJ-4T was identified as representing a novel species of novel genus Pilosibacter fragilis gen. nov. sp. nov. (type strain CSJ-4T=CGMCC 1.18026T= JCM 36513T) of the family Clostridiaceae.

Interleukin-19 in Bone Marrow Contributes to Bone Loss Via Suppressing Osteogenic Differentiation Potential of BMSCs in Old Mice.

BACKGROUND: Cellular senescence is an important process related to the pathogenic mechanism of different disorders, especially bone loss. During senescence, bone marrow stromal cells (BMSCs) lose their self-renewal and functional differentiation abilities. Therefore, finding signals opposing the osteogenic differentiation of BMSCs within bone marrow microenvironment is the important for elucidating these above-mentioned mechanisms. Inflammatory cytokines affect bone physiology and remodeling. However, the function of interleukin-19 (IL-19) in skeletal system remains unclear. METHODS: The mouse model of IL-19 knockout was established through embryonic stem cell injection for analyzing how IL-19 affected bone formation. Micro-CT examinations were performed to evaluate bone microstructures. We performed a three-point bending test to measure bone stiffness and the ultimate force. Antibody arrays were performed to detect interleukin family members in bone marrow aspirates. BMSCs were cultured and induced for osteogenic differentiation. RESULTS: According to our findings, there was increased IL-19 accumulation within bone marrow in old mice relative to that in their young counterparts, resulting in bone loss via the inhibition of BMSCs osteogenic differentiation. Among Wnt/ß-catenin pathway members, IL-19 strongly upregulated sFRP1 via STAT3 phosphorylation. The inhibition of STAT3 and sFRP1 abolished IL-19's inhibition against the BMSCs osteogenic differentiation. CONCLUSION: To sum up, IL-19 inhibited BMSCs osteogenic differentiation in old mice. Our findings shed novel lights on pathogenic mechanism underlying age-related bone loss and laid a foundation for further research on identifying novel targets to treat senile osteoporosis.

Rare Trichilemmal Cyst Localized in the Pulp of the Middle Finger.

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N-Halamine-Based Polypropylene Melt-Blown Nonwoven Fabric with Superhydrophilicity and Antibacterial Properties for Face Masks.

Polypropylene melt-blown nonwoven fabric (PP MNF) masks can effectively block pathogens in the environment from entering the human body. However, the adhesion of surviving pathogens to masks poses a risk of human infection. Thus, embedding safe and efficient antibacterial materials is the key to solving pathogen infection. In this study, stable chlorinated poly(methacrylamide-N,N'-methylenebisacrylamide) polypropylene melt-blown nonwoven fabrics (PP-P(MAA-MBAA)-Cl MNFs) have been fabricated by a simple UV cross-link and chlorination process, and the active chlorine content can reach 3500 ppm. The PP-P(MAA-MBAA)-Cl MNFs show excellent hydrophilic and antibacterial properties. The PP-P(MAA-MBAA)-Cl MNFs could kill all bacteria (both Escherichia coli and Staphylococcus aureus) with only 5 min of contact. Therefore, incorporating PP-P(MAA-MBAA)-Cl MNF as a hydrophilic antimicrobial layer into a four-layer PP-based mask holds great potential for enhancing protection and comfort.

Overexpression of lncRNA-MEG3 inhibits endometrial cell proliferation and invasion via miR-21-5p/DNMT3B/Twist.

Recent studies have found that lncRNA-MEG3(MEG3) plays an important role in the development of EMs (Endometriosis), but the specific mechanism needs to be further explored. This study aimed to investigate the effect of MEG3 on the proliferation, invasion of EMs cells. The authors used RT-qPCR to detect the expression of MEG3 and miR-21-5p in EMs tissues and hESCs cells, MTT and Transwell to detect cell proliferation and invasion, western blotting assay to detect the expression of DNMT3B and Twist, MSP to detect the methylation of Twist. The present study's detection results showed that MEG3 was lowly expressed in EMs tissues and hESCs cells, and overexpression of MEG3 could down-regulate miR-21-5p and inhibit endometrial cell proliferation and invasion. In addition, overexpression of MEG3 upregulated the expression of DNMT3B and promoted the methylation of TWIST. In conclusion, the present findings suggest that MEG3 is downregulated in EMs tissues, and overexpression of MEG3 can promote the activity of DNA methyltransferase DNMT3B by downregulating miR-21-5p, thereby promoting the methylation of Twist, downregulating Twist level to inhibits hESCs cells proliferation and invasion.

Knowledge, attitude, and practice toward disease prevention among a high-risk population for chronic obstructive pulmonary disease: A cross-sectional study.

Objective: This study aimed to describe the current situation of knowledge, attitude, and practice (KAP) of chronic obstructive pulmonary disease (COPD) prevention among a high-risk population for COPD. Methods: A cross-sectional survey was conducted. A total of 241 participants at risk of COPD were selected who visited the respiratory outpatient department of a Class A tertiary hospital in Chongqing, China from January to December 2021. A self-developed COPD prevention KAP assessment was used for evaluation which included knowledge (21 items), attitude (9 items), and practice (9 items) three dimension, 39 items. Results: The average overall KAP score was 68.29 ± 12.91, with scores for the knowledge, attitude, and practice dimension was 68.75 ± 18.07, 71.13 ± 15.09 and 65.00 ± 20.93, respectively. Among the people at risk of COPD, 76.8% experienced a moderate level of KAP toward COPD prevention, while 22.0% were at a poor level. Significant differences in the KAP scores were based on gender, educational level, occupation, type of medical insurance, smoking, and passive smoking status (P < 0.05). The male COPD high-risk group has better KAP toward COPD prevention than the female group (P < 0.05). The knowledge and attitude of COPD prevention present worse in people with a high risk of COPD aged 70 or above, primary school and below educational level, and farmers (P < 0.05). Smoking and passive smoking groups have higher recognition of the knowledge but the lower practice of COPD prevention (P < 0.05). Conclusion: The participants with a high risk of COPD had a moderate level of KAP for COPD prevention, in which the understanding and action on vaccination and lung function test was weak, but an active attitude for health. It is necessary to implement tailored health education interventions to their characteristics to reduce the incidence and development of COPD.

Failure to achieve reduction on developmental dysplasia of hip: an ultrasound evaluation.

BACKGROUND: Ultrasound examination of the medial side of the hip joint has been rarely used to evaluate the status of developmental dysplasia of the hip (DDH) in Pavlik harness treatment according to the literature. PURPOSE: To analyze the effects of cartilaginous acetabulum, hip joint labrum, and acetabular tissue on the reduction of DDH. MATERIAL AND METHODS: A total of 50 cases (100 hips) were detected by the Graf method with a high-frequency linear transducer (L 5-12), and there were 59 dislocated hips and 41 non-dislocated hips. Patients were treated with a Pavlik harness. Ultrasound examination of the medial side of the hip joint was performed for follow-up. The hip joints were divided into three groups: the non-dislocated group; the reducible group; and the non-reducible group. RESULTS: The success rate of reduction was significantly higher when the acetabulum cartilage was located on the cephalic side (chi-square = 28.12, P < 0.001). The success rate was also significantly higher when the hip joint labrum was located on the cephalic side (chi-square = 17.21, P < 0.001). Type III and D had a higher success rate of reduction than type IV (P < 0.001). The pairwise comparison of the measurements of acetabular tissue between the non-dislocated group, the reducible group, and the non-reducible group showed statistical differences (P < 0.001). CONCLUSION: The present study confirmed that the location of acetabulum cartilage and hip joint labrum affected the outcome of treatment. The degree of dislocation and the amount of acetabular tissue were correlated with the success rate of treatment.

Overexpression of lncRNA-MEG3 inhibits endometrial cell proliferation and invasion via miR-21-5p/DNMT3B/Twist

Abstract Recent studies have found that lncRNA-MEG3(MEG3) plays an important role in the development of EMs (Endometriosis), but the specific mechanism needs to be further explored. This study aimed to investigate the effect of MEG3 on the proliferation, invasion of EMs cells. The authors used RT-qPCR to detect the expression of MEG3 and miR-21-5p in EMs tissues and hESCs cells, MTT and Transwell to detect cell proliferation and invasion, western blotting assay to detect the expression of DNMT3B and Twist, MSP to detect the methylation of Twist. The present study's detection results showed that MEG3 was lowly expressed in EMs tissues and hESCs cells, and overexpression of MEG3 could down-regulate miR-21-5p and inhibit endometrial cell proliferation and invasion. In addition, overexpression of MEG3 upregulated the expression of DNMT3B and promoted the methylation of TWIST. In conclusion, the present findings suggest that MEG3 is downregulated in EMs tissues, and overexpression of MEG3 can promote the activity of DNA methyltransferase DNMT3B by downregulating miR-21-5p, thereby promoting the methylation of Twist, downregulating Twist level to inhibits hESCs cells proliferation and invasion.

Determination of pesticides and their degradation products in sediment samples by accelerated solvent extraction and solid-phase extraction with high-performance liquid chromatography-high-resolution mass spectrometry.

A new sensitive and selective methods was developed to quantify different types of pesticides and their degradation products in sediment. The method developed was optimized and modified based on the accelerated solvent extraction, followed by the solid-phase extraction clean-up technique. High-performance liquid chromatography coupled with mass spectrometry was used for analysis. The influence of various parameters on the extraction process was investigated, including the extraction temperature, extraction solvent, purification column and purification solvent, etc. Under the optimal conditions, the relative recoveries of the pesticides and their degradation products ranged from 80 to 106% for spiked blank sediment and environmental sediment samples with relative standard deviations of 1-9%. The method displayed low method detection limits for both sediment matrices and achieved good linearity over the tested range of concentrations. The physical and chemical properties of sediment showed that high content of sediment water content and humic acid would affect the extraction efficiency of sample pretreatment. The method was applied to environmental sediment to quantify pesticide residues in the samples. Based on the instrument and method performance validation results, the developed methods can be applied in environmental pesticide residue analysis, thus providing a scientific method for the detection of sediment samples.

Intravenous Transplantation of Human Hair Follicle-Derived Mesenchymal Stem Cells Ameliorates Trabecular Bone Loss in Osteoporotic Mice.

Background: Hair follicles harbor a rich autologous stem cell pool and human hair follicle-derived mesenchymal stem cells (hHF-MSCs) have multi-lineage differentiation potential. Many sources of MSCs include hHF-MSCs have been attractive candidates for cell therapy, regenerative medicine and tissue engineering. The present study is to explore the effect of intravenous transplantation of hHF-MSCs on bone mass in osteoporotic mice and its mechanism, and provides prospects for clinical applications for the treatment of osteoporosis with hHF-MSCs. Methods: Physically pull out about 20 hairs with intact hair follicles from the occipital area of the scalp of healthy volunteers, and extract hair follicle-derived fibroblast-like cells. These cells were cultured and characterized in vitro. Intravenous injection of hHF-MSCs was performed on ovariectomy-induced and age-related osteoporotic SCID mice for osteoporosis treatment. The mice were sacrificed 7 weeks after the second injection and samples were collected. The long bones and L1 vertebrae were collected for micro-CT scan, histomorphometry and immunohistochemical analysis. Peripheral serum were collected for ELISA analysis and antibody array. Results: Hair follicle-derived fibroblast-like cells were defined as hHF-MSCs. Intravenous transplantation of hHF-MSCs can better restores trabecular bone mass in osteoporotic mice. The double calcein labeling assay, trap staining of bones and ELISA analysis in peripheral serum showed enhanced bone formation and weakened bone resorption after transplantation. Antibody array and immunohistochemical analysis showed that several cytokines including OPG, Wnt2b, Noggin, VCAM-1 and RANKL might be involved in this process. Conclusion: Human HF-MSCs transplantation can combat trabecular bone loss induced by menopause and aging in mice. And the above mechanism that hHF-MSCs transplantation inhibits bone resorption and promote bone formation is related to OPG, Wnt2b, VCAM-1, Noggin and RANKL.

Comparison of comorbidities among severe and non-severe COVID-19 patients in Asian versus non-Asian populations: A systematic review and meta-analysis.

OBJECTIVES: This study aimed to evaluate the comorbidities among severe and non-severe COVID-19 patients in Asian versus non-Asian populations. DESIGN: Systemic review and Meta-analysis. METHODS: A systematic literature search was conducted using PubMed, Embase, Scopus and the web of science Database up to 24 March 2021. Odds ratios were calculated using a random-effects model. RESULTS: We identified 66 studies including 39 Asian and 27 non-Asian studies. This study demonstrated that the proportion of hypertension was significantly higher in severe group than in non-severe group for Asian (OR = 2.46) and non-Asian (OR = 1.60, 95% CI: 1.37-1.86, I2  = 84%; p < .00001) patients. Similarly, the proportion of diabetes, cardiovascular disease and chronic kidney disease was significantly higher in severe group than in non-severe group for both Asian and non-Asian studies. We found no statistically significant difference between the severe versus non-severe group for cancer (OR = 1.26) and chronic obstructive pulmonary disease (OR = 1.32) among non-Asian patients.

The pulmonary infection risk factors in long-term bedridden patients: a meta-analysis.

This study aimed to review the pulmonary infection risk factors in long-term bedridden patients. The Cochrane Library, PubMed, EMBASE, Web of Science, CNKI, Wanfang, and the China Biomedical Literature Service System databases were searched to retrieve articles on the clinical risk factors, from database establishment to July 31, 2020. Two researchers independently screened the search results, evaluated the quality of the studies using NOS criteria, and extracted the data. The meta-analysis was performed using RevMan 5.3. A total of 13 articles including 10,182 patients were included. The statistically significant risk factors included age (OR=1.82), diabetes (OR=2.15), hormones (OR=3.14), consciousness disorders (OR=3.83), BMI<18.5 kg/m2 (OR=1.57), antibiotics (OR=2.21), smoking history (OR=1.68), nasal-feeding (OR=4.64), ventilator use (OR=5.95), invasive operations (OR=5.04), hospitalization times (OR=3.16), and stay-in-bed times (OR=2.69). Therefore, according to the OR values, age, a BMI<18.5 kg/m2, and smoking history were low risk-factors (2≥OR>1). Diabetes, antibiotics, and stay-in-bed times were medium risk-factors (3≥OR>2). Hormone levels, consciousness disorders, nasal-feeding, ventilator use, invasive operations, and hospitalization times were high risk-factors (OR>3). In conclusion, the low risk-factors (age, BMI, smoking history), the medium risk-factors (diabetes, antibiotics, stay-in-bed length), and especially the high risk-factors (hormones, consciousness disorders, nasal-feeding, ventilator use, invasive operations, hospitalization times) deserve more attention for preventing pulmonary infections in long-term bedridden patients.

Rare hand mass: malignant peripheral nerve sheath tumor.

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Effect of Activated Platelet-Rich Plasma on Chondrogenic Differentiation of Rabbit Bone Marrow-Derived Mesenchymal Stem Cells.

We aimed to evaluate the effect of activated platelet-rich plasma (PRP) on proliferation and chondrogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Six mature male rabbits were included in this study. PRP was obtained by two-step centrifugation from whole blood, and it was activated using CaCl2 solution. BMSCs were isolated and proliferated from bone marrow of rabbits and characterized by flow cytometry. Passage 3 BMSCs were cultured in high-glucose Dulbecco's modified Eagle's medium (HG-DMEM) with the four different compositions for consecutive 7 days, including 10% fetal bovine serum, 5% PRP, 10% PRP, and 15% PRP. Cell counting assays were performed to evaluate the cell proliferation of BMSCs. BMSCs (5 × 105 cells/well in 6-well plates) were induced in four conditions for 21 days to chondrogenic differentiation evaluation, including commercial chondrogenic medium (control), 5% PRP (HG-DMEM+5% PRP), 10% PRP (HG-DMEM+10% PRP), and 15% PRP (HG-DMEM+15% PRP). The gene expression levels of ACAN, COL2A1, and SOX9 in pellets were detected. Morphological and pathological assessments were performed by the blind observer. After purifying, the percentages of cells with CD105(+)/CD34(-) and CD44(+)/CD45(-) were 96.5% and 92.9%, respectively. The proliferation of BMSCs was enhanced in all groups, and 10% PRP revealed more significant outcome than the others from day 5. The levels of ACAN, COL2A1, and SOX9 were lower in the three PRP groups than control group, but the levels of ACAN and SOX9 were higher in 10% PRP group than 5% and 15% PRP groups. Histological examinations showed that 10% PRP-treated pellets had more regular appearance, larger size, and abundant extracellular matrix than 5% or 10% PRP groups, but still inferior to commercial chondrogenic medium. In conclusion, our results show that PRP may enhance the proliferation of rabbit BMSCs. However, PRP have limited effect on chondrogenic differentiation in comparison with commercial chondrogenic medium in pellets culture.

Research on the factors that influence patients with colorectal cancer participating in the prevention and control of surgical site infection: Based on the extended theory of planned behaviour.

BACKGROUND: The most common and severe type of nosocomial infection in patients with colorectal cancer is surgical site infection (SSI). Patient-related factors are an important components of SSI. So it is necessary to participate in SSI prevention and control. It is important to identify the factors that influence patients' participation behaviour and to explore the mechanism of these effects. METHODS: A total of 580 patients with colorectal cancer completed relevant measures. Based on the extended theory of planned behaviour, a structural equation model was used to analyse the relationship among the influencing factors. RESULTS: The factors influencing participation of patients with colorectal cancer in SSI prevention and control were participation intention, participation ability, self-efficacy, participation attitude, perceived medical staff support, trust in physicians and social support. The direct effect coefficients of participation intention, participation ability and physician trust on SSI prevention and control behaviour were 0.67, 0.21 and 0.11, respectively. Self-efficacy, participation attitude, perceived medical staff support and social support indirectly affect participation behaviour through participation intention, and their effect values are 0.21, 0.11, 0.11 and 0.08, respectively. CONCLUSIONS: Based on the structural equation model developed in this study, targeted intervention measures should be implemented to mobilize the intention and enthusiasm of patients with colorectal cancer to participate in the prevention and control of SSI. PATIENT OR PUBLIC CONTRIBUTION: Patients or public contribute to spreading research findings, and promote broad participation in the implementation of policies or strategies.

lncRNA NEAT1 aggravates sepsis-induced lung injury by regulating the miR-27a/PTEN axis.

Sepsis is an acute inflammatory reaction and a cause of acute respiratory distress syndrome (ARDS). In the present study, we explored the roles and underlying mechanism of the lncRNA Nuclear enriched abundant transcript 1 (NEAT1) in ARDS. The expression levels of genes, proteins and pro-inflammatory cytokines in patients with ARDS, LPS-stimulated cells and septic mouse models were quantified using qPCR, western blotting and ELISA assays, respectively. The molecular targeting relationship was validated by conducting a dual-luciferase reporter assay. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay. The cell cycle phase was determined by flow cytometry assay. The expression levels of NEAT1 and pro-inflammatory cytokines were higher in patients with ARDS and septic models than in controls. Knockdown of NEAT1 significantly increased cell proliferation and cycle progression and prolonged mouse survival in vitro and in vivo. Mechanistically, miR-27a was identified as a downstream target of NEAT1 and directly inhibited PTEN expression. Further rescue experiments revealed that inhibition of miR-27a impeded the promoting effects of NEAT1 silence on cell proliferation and cycle progression, whereas inhibition of PTEN markedly weakened the inhibitory effects of NEAT1 overexpression on cell proliferation and cycle progression. Altogether, our study revealed that NEAT1 plays a promoting role in the progression of ARDS via the NEAT1/miR-27a/PTEN regulatory network, providing new insight into the pathologic mechanism behind ARDS.

The disulfiram/copper complex induces apoptosis and inhibits tumour growth in human osteosarcoma by activating the ROS/JNK signalling pathway.

Given the huge cost, long research and development (R&D) time and uncertain side effects of discovering new drugs, drug repositioning of those approved to treat diseases clinically as new drugs for other pathological conditions, especially cancers, is a potential alternative strategy. Disulfiram (DSF), an old drug used to treat alcoholism, has been found to exhibit anticancer activity and improve chemotherapeutic efficacy in cancers by an increasing number of studies. In addition, the combination of DSF and copper may be a more effective therapeutic strategy. In this study, we report the toxicity of the disulfiram/copper (DSF/Cu) complex to human osteosarcoma (OS) both in vitro and in vivo. DSF/Cu significantly inhibited the proliferation and clonogenicity of OS cell lines. Furthermore, the generation of reactive oxygen species (ROS) was triggered by DSF/Cu, and cell arrest, autophagy and apoptosis were induced in an ROS-dependent manner. The underlying mechanism of this process was explored, and DSF/Cu may mainly inhibit OS by inducing apoptosis by activating the ROS/JNK pathway. DSF/Cu also inhibited OS growth in a xenograft model with low levels of organ-related toxicities. These results suggest that the DSF/Cu complex could be an efficient and safe option for the treatment of OS in the clinic.

N-Halamine Polypropylene Nonwoven Fabrics with Rechargeable Antibacterial and Antiviral Functions for Medical Applications.

Embedding medical and hygiene products with regenerable antimicrobial functions would have significant implications for limiting pathogen contaminations and reducing healthcare-associated infections. Herein, we demonstrate a scalable and industrially feasible methodology to fabricate chlorine rechargeable melt-blown polypropylene (PP) nonwoven fabrics, which have been widely used in hygienic and personal protective products, via a combination of a melt reactive extrusion process and melt-blown technique. Methacrylamide (MAM) was employed as a precursor of halamine monomers and covalently grafted onto the PP backbone to form polypropylene-grafted methacrylamide (PP-g-MAM), which could be chlorinated, yielding biocidal acyclic halamines. Subsequently, the resultant PP-g-MAM was manufactured into nonwoven fabrics with varying fiber diameters by adjusting the hot air flowing speed during the melt-blowing process. The chlorinated nonwoven fabrics (PP-g-MAM-Cl) exhibited integrated properties such as a robust mechanical property, good thermal stability, high chlorination capability (>850 ppm), and desirable chlorine rechargeability. More importantly, such chlorinated nonwoven fabrics showed a promising antibacterial and antiviral efficiency, achieving 6 log CFU reduction of bacteria (both Escherichia coliO157: H7 and Listeria innocua) and 7 log PFU reductions of a virus (T7 bacteriophages) within 15 and 5 min of contact, respectively, revealing great potential to serve as a reusable antimicrobial material for medical protection applications.

Osteosarcoma-derived exosomal miR-501-3p promotes osteoclastogenesis and aggravates bone loss.

Emerging evidence indicates that osteoclasts from osteosarcoma patients have higher tartrate resistant acid phosphatase (TRAP) activity. Exosomes are important mediators of the cell-to-cell communication. However, whether osteosarcoma cell-derived exosomes mediate the osteoclastogenesis of bone marrow-derived monocytes (BMDMs) and its mechanisms are largely unknown. In this research, we validated the communication between osteosarcoma cells and BMDMs. Here, we found that osteosarcoma cell-derived exosomes can be transfered to BMDMs to promote osteoclast differentiation. The miR-501-3p is highly expressed in exosomes derived from osteosarcoma and could be transferred to BMDMs through the exosomes. Moreover, osteosarcoma-derived exosomal miR-501-3p mediate its role in promoting osteoclast differentiation and aggravates bone loss in vitro and in vivo. Mechanistically, osteosarcoma cell-derived exosomal miR-501-3p could promote osteoclast differentiation via PTEN/PI3K/Akt signaling pathway. Collectively, our results suggest that osteosarcoma-derived exosomal miR-501-3p promotes osteoclastogenesis and aggravates bone loss. Therefore, our study reveals a novel mechanism of osteoclastogenesis in osteosarcoma patients and provides a novel target for diagnosis or treatment.