Identification and treatment of intestinal malrotation with midgut volvulus in childhood: a multicenter retrospective study.

Background: Intestinal malrotation is a rare condition, and its delayed diagnosis can lead to fatal consequences. This study aimed to investigate the identification and treatment of malrotation in children. Methods: Clinical data, imaging, operative findings, and early postoperative outcomes of 75 children with malrotation were retrospectively analyzed. Results: The mean age was 6.18 ± 4.93 days and 51.26 ± 70.13 months in the neonatal group (56 patients) and non-neonatal group (19 patients), respectively. Sixty-seven patients were under the age of 1 year at the time of diagnosis. The occurrence of bilious vomiting and jaundice was significantly higher in the neonatal group (89.29%) than that in the non-neonatal group (37.5%), p < 0.05 and p < 0.01, respectively. The incidence of abnormal ultrasound (US) findings was 97.30% and 100%, respectively, and the sensitivities of the upper gastrointestinal series were 84.21% and 87.5%, respectively. Sixty-six (88%) patients had midgut volvulus, including in utero volvulus (two patients) and irreversible intestinal ischemia (four patients). Most neonates (89.29%) underwent open Ladd's procedure with a shorter operative time (p < 0.01). Reoperation was performed for postoperative complications (four patients) or missed comorbidities (two patients). Conclusions: Non-bilious vomiting was the initial symptom in >10% of neonates and nearly 40% of non-neonates. This highlights the importance for emergency physicians and surgeons to be cautious about ruling out malrotation in patients with non-bilious vomiting. Utilizing US can obviate the need for contrast examinations owing to its higher diagnostic accuracy and rapid diagnosis and can be recommended as a first-line imaging technique. Additionally, open surgery is still an option for neonatal patients.

Single-cell and spatial transcriptomics reveal metastasis mechanism and microenvironment remodeling of lymph node in osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor and is highly prone to metastasis. OS can metastasize to the lymph node (LN) through the lymphatics, and the metastasis of tumor cells reestablishes the immune landscape of the LN, which is conducive to the growth of tumor cells. However, the mechanism of LN metastasis of osteosarcoma and remodeling of the metastatic lymph node (MLN) microenvironment is not clear. METHODS: Single-cell RNA sequencing of 18 samples from paracancerous, primary tumor, and lymph nodes was performed. Then, new signaling axes closely related to metastasis were identified using bioinformatics, in vitro experiments, and immunohistochemistry. The mechanism of remodeling of the LN microenvironment in tumor cells was investigated by integrating single-cell and spatial transcriptomics. RESULTS: From 18 single-cell sequencing samples, we obtained 117,964 cells. The pseudotime analysis revealed that osteoblast(OB) cells may follow a differentiation path from paracancerous tissue (PC) → primary tumor (PT) → MLN or from PC → PT, during the process of LN metastasis. Next, in combination of bioinformatics, in vitro and in vivo experiments, and immunohistochemistry, we determined that ETS2/IBSP, a new signal axis, might promote LN metastasis. Finally, single-cell and spatial dissection uncovered that OS cells could reshape the microenvironment of LN by interacting with various cell components, such as myeloid, cancer-associated fibroblasts (CAFs), and NK/T cells. CONCLUSIONS: Collectively, our research revealed a new molecular mechanism of LN metastasis and clarified how OS cells influenced the LN microenvironment, which might provide new insight for blocking LN metastasis.

Deep removal of trace arsenic from acidic SbCl3 solution by in-situ galvanically coupled Cu2Sb/Cu particles.

Arsenic is a harmful associated element in antimony ore, which might bring out the risk of leakage during complex industrial production of high-purity antimony. Herein, we reported a novel and efficient way to remove the trace arsenic impurity from acidic SbCl3 solution by utilizing copper-system bimetallic particles. Specifically, galvanically coupled Cu2Sb/Cu was in-situ synthesized by introducing precursor copper powder to the specific SbCl3 solution. DFT studies revealed that Sb(III) was easily reduced by Cu to form Cu2Sb due to the strong adsorption of Sb(III) on Cu (111) crystal plane. The Cu2Sb/Cu coupling exhibited excellent activity for As(III) reduction, over 99.4% arsenic were removed under optimal conditions and residual arsenic concentration dropped to only 2.7 mg L-1. Crucially, Sb(III) concentration changes could be neglected. Besides, the dearsenization residues were extensively characterized to analyze the evolvement and cause in the reaction process. The results confirmed that the arsenic removal mechanisms by Cu2Sb/Cu particles were multi-affected, including adsorption, displacement, and precipitation. And the strong electrostatic attraction of AsO+ under high HCl conditions was identified as a key step to achieving dearsenization. This research will provide a theoretical guidance for the green synthesis of high-purity antimony and related products.

Single-cell RNA sequencing reveals the immune microenvironment landscape of osteosarcoma before and after chemotherapy.

Chemotherapy, a primary treatment for osteosarcoma (OS), has limited knowledge regarding its impact on tumor immune microenvironment (TIME). Here, tissues from 6 chemotherapy-naive OS patients underwent single-cell RNA sequencing (scRNA-seq) and were analyzed alongside public dataset (GSE152048) containing 7 post-chemotherapy OS tissues. CD45+ (PTPRC+) cells were used for cell clustering and annotation. Changes in immune cell composition pre- and post-chemotherapy were characterized. Totally, 28,636 high-quality CD45+ (PTPRC+) cells were extracted. Following chemotherapy, the proportions of regulatory T cells (Tregs) and activated CD8 T cells decreased, while CD8 effector T cells increased. GO analysis indicated that differentially expressed genes (DEGs) in T cells were associated with cell activation, adaptive immune response, and immune response to tumor cells. Furthermore, the proportions of plasma cells increased, while naive B cells decreased. B cell surface receptors expression was upregulated, and GO analysis revealed DEGs of B cells were mainly enriched in B cell-mediated immunity and B cell activation. Moreover, M2 polarization of macrophages was suppressed post-chemotherapy. Overall, this study elucidates chemotherapy remodels the OS TIME landscape, triggering immune heterogeneity and enhancing anti-tumor properties.

Ketogenic diet attenuates cognitive dysfunctions induced by hypoglycemia via inhibiting endoplasmic reticulum stress-dependent pathways.

Hypoglycemia can potentially cause severe damage to the central nervous system. The ketogenic diet (KD), characterized by high-fat and extremely low-carbohydrate content, can modulate homeostasis and nutrient metabolism, thereby influencing body health. However, the effects and underlying mechanisms of KD on hypoglycemia-induced brain injury have not been thoroughly investigated. We aimed to explore the modulating effects of KD on cognitive functions and elucidate the underlying mechanisms. In this study, one-month-old mice were fed with KD for 2 weeks, and the changes in the gut microbiota were detected using the 16S rRNA gene amplicon sequencing method. The hypoglycemic model of mice was established using insulin, and the potential protective effect of KD on hypoglycemia-induced brain injury in mice was evaluated through immunofluorescence staining, western blotting, transmission electron microscopy, and Golgi staining. Our results showed that the intestinal flora of Dorea increased and Rikenella decreased in KD-fed mice. KD can not only alleviate anxiety-like behavior induced by hypoglycemia, but also increase the proportion of mushroom dendritic spines in the hippocampus by modulating changes in the gut microbiota. KD regulated synaptic plasticity by increasing the levels of SPN, PSD95, and SYP, which relieve cognitive impairment caused by hypoglycemia. Moreover, KD can promote the proliferation and survival of adult neural stem cells in the hippocampus, while reducing apoptosis by suppressing the activation of the IRE1-XBP1 and ATF6 endoplasmic reticulum stress pathways in mice with hypoglycemia. This study provides new evidence for demonstrating that KD may alleviate cognitive dysfunctions caused by hypoglycemia by modulating the gut microbiota.

Development and validation of neutrophil extracellular traps-derived signature to predict the prognosis for osteosarcoma patients.

Neutrophil extracellular traps (NETs) have been reported to be crucial in tumorigenesis and malignant progression. However, their prognostic significance, association with tumor immune microenvironment (TIME), and therapeutic response in osteosarcoma (OS) stills remain unclear. Hence, TARGET and GSE21257 cohorts were included for analysis. Single-sample gene set enrichment analysis (ssGSEA) and weighted gene co-expression network analysis (WGCNA) were conducted to extract NETs-derived genes. Subsequently, the NETs score (NETScore) model, consisting of 4 signature genes, was established and validated with the least absolute shrinkage and selection operator (LASSO) and Cox regression analysis. Our results indicated that NETScore has satisfactory predictability of the patient's overall survival, with AUC values at 1-, 3- and 5-year in the training cohort of 0.798, 0.792 and 0.804, respectively; similar prominent prediction performance was obtained in three validation cohorts. Further, real-time quantitative PCR (RT-qPCR) assay was conducted to determine the expression of signature genes in human osteoblasts and OS cells. Besides, NETScore and clinical factors (age, gender, metastatic status) were integrated to construct a nomogram. C-index and AUC values at 1-, 3-, and 5-year were above 0.800, displaying robust predictive performance. Patients with high and low NETScore had different immune statuses and drug sensitivity. Meanwhile, several positive regulatory immune function pathways, including T cell proliferation, activation and migration, were significantly suppressed among patients with high NETScore. Summarily, we established a novel NETScore that can accurately predict OS patients' prognosis, which correlated closely with the immune landscape and therapeutic response and might help to guide clinical decision-making.

Association of survivin positive circulating tumor cell levels with immune escape and prognosis of osteosarcoma.

PURPOSE: Function of survivin protein (encoded by BIRC5) in circulating tumor cells (CTCs) of osteosarcoma (OS) has not been investigated. The goal of this study is to determine whether the expression of survivin protein of CTCs is associated with circulating immune cell infiltration and disease prognosis of OS. METHODS: Blood samples of 20 patients with OS were collected. CanPatrol™ CTC enrichment technology combined with in situ hybridization (ISH) was applied to enrich and test CTCs and survivin protein. Bioinformation analysis combined with data of routine blood test was used to verify the association between survivin and immune cell infiltration in circulatory system. To screen independent prognostic factors, Kaplan-Meier survival curve, univariate and multivariable Cox regression analyses were performed. RESULTS: Bioinformatics analysis showed that BIRC5 was strongly negatively related to lymphocyte, including T cell, NK cell and B cell, which released that BIRC5 played a key role in immune escape via reducing immune cell infiltration in circulatory system. Meanwhile, the number of survivin+ CTCs was significantly negatively connection with lymphocyte count (R = -0.56, p = 0.011), which was consistent with bioinformatics analysis. Kaplan-Meier curve showed that the overall survival rate in high survivin+ CTCs group was significantly lower than low group (88.9% vs 36.4%, p = 0.04). Multivariable Cox regression analyses showed that survivin+ CTCs were an independent prognostic factor (p = 0.019). CONCLUSION: These findings suggested that survivin protein played a key role in immune escape of CTCs and the presence of survivin+ CTCs might be a promising prognostic factor in OS patients.

A new insight of immunosuppressive microenvironment in osteosarcoma lung metastasis.

The lung is the primary organ for the metastasis of osteosarcoma. Although the application of neoadjuvant chemotherapy and surgery has remarkably improved the survival rate of patients with osteosarcoma, prognosis is still poor for those patients with metastasis. In this study, we performed further bioinformatics analysis on single-cell RNA sequencing (scRNA-seq) data published before, containing 75,317 cells from two osteosarcoma lung metastasis and five normal lung tissues. First, we classified 17 clusters, including macrophages, T cells, endothelial cells, and so on, indicating highly intratumoral heterogeneity in osteosarcoma lung metastasis. Next, we found macrophages in osteosarcoma lung metastasis did not have significant M1 or M2 polarizations. Then, we identified that T cells occupied the most abundant among all cell clusters, and found CD8+ T cells exhibited a low expression level of immune checkpoints in osteosarcoma lung metastasis. What is more, we identified C2_Malignant cells, and found CD63 might play vital roles in determining the infiltration of T cells and malignant cells in conventional-type osteosarcoma lung metastasis. Finally, we unveiled C1_Therapeutic cluster, a subcluster of malignant cells, was sensitive to oxfendazole and mevastatin, and the potential hydrogen-bond position and binding energy of oxfendazole-KIAA0907 and mevastatin-KIAA0907 were unveiled, respectively. Our results highlighted the power of scRNA-seq technique in identifying the complex tumor microenvironment of osteosarcoma lung metastasis, making it possible to devise precision therapeutic approaches.

Long non-coding RNA and circular RNA and coding RNA profiling of plasma exosomes of osteosarcoma by RNA seq.

Osteosarcoma (OS) is a primary bone tumor with high malignancy and the mechanism of hematogenous metastasis in OS is still not clear. The plasma exosomes derived from osteosarcoma play a key role in the process of tumor metastasis. Here, we established RNA-seq dataset for lncRNAs, circRNAs and mRNAs in plasma exosomes from 10 OS patients and 5 healthy donors. A total of 329.52 Gb of clean data was obtained. Besides, 1754 lincRNAs, 7096 known and 1935 new circRNA was identified. Finally, gene expression profiles and differentially expressed genes (DEGs) were analyzed among these 15 samples. There were 331 DEGs of mRNA, 132 of lincRNA and 489 of circRNA was obtained, respectively. This data set provides a significant resource for relevant researchers to excavate potential dysregulated lncRNAs, circRNAs and mRNAs of plasma exosomes in OS versus normal conditions.

A minimally invasive technique for residual zigzag deformities of the thumb.

OBJECTIVE: This study aimed to introduce a minimally invasive technique in correcting residual zigzag deformities after early treatment of thumb duplication followed by fixation with a cemented frame. METHODS: Nineteen patients (14 males, 5 females; mean age, 12 years; age range, 8-14 years) with residual zigzag thumb deformities were treated with the minimally invasive technique from 2017 to 2019. The function and cosmesis of the thumbs were assessed using the Japanese Society for Surgery of the Hand. RESULTS: The mean period between the first and the second operations was 35 months (range, 12-84 months). There were Wassel types III (n=4), IV (n=13), and V (n=2) residual zigzag thumb deformities. Preoperatively, the mean alignment deformities of the interphalangeal and metacarpophalangeal joints were 23° (12-42°) and 18° (11-33°), respectively. The mean function and cosmesis of the thumbs were 12 points (range, 8-14 points). There were 1 fair and 18 poor scores. At the final follow-up (mean, 28 months; range, 24-33 months), the mean alignment deformities of the interphalangeal and metacarpophalangeal joints were 1° (0-4°) and 18° (0-4°), respectively. The mean function and cosmesis of the thumbs were 18 points (range, 16-20 points). There were 5 excellent results, 13 good results, and 1 fair result. CONCLUSION: Residual zigzag thumb deformities can be successfully corrected with the minimally invasive technique, resulting in good functional and cosmetic outcomes. The technique can be used as an alternative in selected cases. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

Interaction gene set between osteoclasts and regulatory CD4+ T cells can accurately predict the prognosis of patients with osteosarcoma.

Osteoclasts (OCs) and regulatory CD4+ T cells (CD4+ Tregs) are important components in the tumor microenvironment (TME) of osteosarcoma. In this study, we collected six osteosarcoma samples from our previous study (GSE162454). We also integrated a public database (GSE152048), which included single cell sequencing data of 11 osteosarcoma patients. We obtained 138,192 cells and then successfully identified OCs and CD4+ Tregs. Based on the interaction gene set between OCs and CD4+ Tregs, patients from GSE21257 were distinguished into two clusters by consensus clustering analysis. Both the tumor immune microenvironment and survival prognosis between the two clusters were significantly different. Subsequently, five model genes were identified by protein-protein interaction network based on differentially upregulated genes of cluster 2. Quantitative RT-PCR was used to detect their expression in human osteoblast and osteosarcoma cells. A prognostic model was successfully established using these five genes. Kaplan-Meier survival analysis found that patients in the high-risk group had worse survival (p = 0.029). Therefore, our study first found that cell-cell communication between OCs and CD4+ Tregs significantly alters TME and is connected to poor prognosis of OS. The model we constructed can accurately predict prognosis for osteosarcoma patients.

RNA-seq and Single-Cell Transcriptome Analyses of TRAIL Receptors Gene Expression in Human Osteosarcoma Cells and Tissues.

Osteosarcoma (OS) is the most common primary cancer in the skeletal system, characterized by a high incidence of lung metastasis, local recurrence and death. Systemic treatment of this aggressive cancer has not improved significantly since the introduction of chemotherapy regimens, underscoring a critical need for new treatment strategies. TRAIL receptors have long been proposed to be therapeutic targets for cancer treatment, but their role in osteosarcoma remains unclear. In this study, we investigated the expression profile of four TRAIL receptors in human OS cells using total RNA-seq and single-cell RNA-seq (scRNA-seq). The results revealed that TNFRSF10B and TNFRSF10D but not TNFRSF10A and TNFRSF10C are differentially expressed in human OS cells as compared to normal cells. At the single cell level by scRNA-seq analyses, TNFRSF10B, TNFRSF10D, TNFRSF10A and TNFRSF10C are most abundantly expressed in endothelial cells of OS tissues among nine distinct cell clusters. Notably, in osteoblastic OS cells, TNFRSF10B is most abundantly expressed, followed by TNFRSF10D, TNFRSF10A and TNFRSF10C. Similarly, in an OS cell line U2-OS using RNA-seq, TNFRSF10B is most abundantly expressed, followed by TNFRSF10D, TNFRSF10A and TNFRSF10C. According to the TARGET online database, poor patient outcomes were associated with low expression of TNFRSF10C. These results could provide a new perspective to design novel therapeutic targets of TRAIL receptors for the diagnosis, prognosis and treatment of OS and other cancers.

Ketogenic Diet Alleviates Hypoglycemia-Induced Neuroinflammation via Modulation the Gut Microbiota in Mice.

SCOPE: This study aims to investigate the role of gut microbiota regulation with ketogenic diet (KD) in hypoglycemia-induced neuroinflammation. METHODS AND RESULTS: Immunofluorescence staining and western blotting show that KD alleviates blood-brain barrier injury induced by hypoglycemia by increasing Podxl and zonula occludens-1 (ZO-1) levels. KD-fed mice show reduced brain edema by decreasing aquaporin-4 (AQP4) content and maintaining its polarized expression. 16S rRNA gene amplicon sequencing results show that KD reduces the Chao 1 index of gut microbiota α-diversity, and significant separation is detected in the ß-diversity analysis between the control and KD-fed mice. KD increases the relative abundance of Firmicutes and Proteobacteria and decreases that of Bacteroidetes. Hypoglycemia can reduce SOD and GSH-PX levels while increasing TNF-α, IL-1ß, and IL-6 mRNA levels in the brain tissues of mice. KD alleviates hypoglycemia-induced neuroinflammation by inhibiting microglia activation and TLR4/p38MAPK/NF-κB signaling pathway. Importantly, antibiotic cocktail depletion of the gut microbiota weakens anti-inflammatory and antioxidation responses in KD-fed mice. CONCLUSION: Collectively, these findings suggest that KD alleviates hypoglycemia-induced brain injury via gut microbiota modulation, which may provide novel insights into the therapy for hypoglycemia.

Integrative Single-Cell Analysis Reveals Transcriptional and Epigenetic Regulatory Features of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) frequently features a high level of tumor heterogeneity. Elucidating the chromatin landscape of ccRCC at the single-cell level could provide a deeper understanding of the functional states and regulatory dynamics underlying the disease. Here, we performed single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin using sequencing (scATAC-seq) on 19 ccRCC samples, and whole-exome sequencing was used to understand the heterogeneity between individuals. Single-cell transcriptome and chromatin accessibility maps of ccRCC were constructed to reveal the regulatory characteristics of different tumor cell subtypes in ccRCC. Two long noncoding RNAs (RP11-661C8.2 and CTB-164N12.1) were identified that promoted the invasion and migration of ccRCC, which was validated with in vitro experiments. Taken together, this study comprehensively characterized the gene expression and DNA regulation landscape of ccRCC, which could provide new insights into the biology and treatment of ccRCC. SIGNIFICANCE: A comprehensive analysis of gene expression and DNA regulation in ccRCC using scATAC-seq and scRNA-seq reveals the DNA regulatory programs of ccRCC at the single-cell level.

Trends of denosumab-related publications in web of science.

Denosumab is a human monoclonal antibody that targets nuclear factor-kappa B ligand and is highly effective in blocking bone resorption. Bibliometrics can intuitively show the research development process, research status, research hotspots and development trend of a certain topic for researchers. This study assessed the course of research and development for denosumab in terms of publications over the past 2 decades. Web of Science databases were searched to identify publications related to research on denosumab from January 1, 2005 to December 31, 2022. The VOS Viewer software (version 1.6.17) and Bibliometrix package in R (version 4.1.3) were used in this study. There were 5119 denosumab-related publications during this period. The total number of citations of denosumab-related publications reached 94917. The most articles were published in the field of Endocrinology Metabolism. As an international language, English remains the most popular language for writing papers. Five of the top ten institutions originated in the USA. Through the VOS Viewer analysis, we found that the relationships between Amgen Inc. with its collaborations were grouped into 4 clusters, the USA was the mainland for research and development on denosumab, closely collaborating with many other countries, such as Canada, Japan, England, and China. Wagman RB from USA was the most prolific author with 119 publications. The journal with the most publications was Osteoporosis International (481 publications). The most cited article was "Denosumab for Prevention of Fractures in Postmenopausal Women with Osteoporosis" with 2053 citations. The clinical trial comprised 6 of the 10 most frequently cited publications, and the rest consisted of reviews. The most frequent keywords for publications since January 1, 2014 were "prevention" and "management," indicating that a number of prevention and management measures have been developed to regulate the use of denosumab in treating osteoporosis. Our research provided a comprehensive review of denosumab-related publications, suggesting that the development of denosumab is a long process and numerous clinical trials have been conducted before applications in clinical settings.

Analysis of scRNA-seq and bulk RNA-seq demonstrates the effects of EVI2B or CD361 on CD8+ T cells in osteosarcoma.

Osteosarcoma (OS) is a common primary malignant tumor of the bone in children and adolescents. The five-year survival rate is estimated to be ~70% based on the currently available treatment modalities. It is well known that tumor-infiltrating immune cells (TIICs) that are the most important components in the tumor microenvironment can exert a killing effect on tumor cells. Therefore, in the present study, 85 RNA-sequencing OS samples were categorized into high- and low-immune score groups with ESTIAMATE. Based on the immune score groups, 474 differentially expressed genes (DEGs) were acquired using the LIMMA package of R language. Subsequently, 86 DEGs were taken through univariate COX regression analysis, of which 14 were screened out by least absolute shrinkage and selection operator regression analysis. Furthermore, multivariate COX regression analysis was performed to obtain 4 DEGs. Finally, ecotropic virus integration site 2B (EVI2B) or CD361 gene was screened out via Kaplan-Meier analysis. In addition, CIBERSORT algorithm was used to evaluate the proportion of 22 kinds of TIICs in OS. Correlation analysis revealed that the high expression level of EVI2B can elevate the infiltrated proportion of CD8+ T cells. Moreover, analysis of single cell RNA-sequencing transcriptome datasets and immunohistochemical staining uncovered that EVI2B was mainly expressed on CD8+ T cells and that EVI2B could promote the expression of granzyme A and K of CD8+ T cells to exhibit a potent killing effect on tumor cells. Therefore, EVI2B was identified as a protective immune-related gene and contributed to good prognosis in OS patients.

Circ_0001060 Upregulates and Encourages Progression in Osteosarcoma.

Circular RNA (circRNA) is involved in the occurrence and development of various cancers. To this day, the expression and mechanism of circRNA in osteosarcoma (OS) remain unclear. We previously found that circ_0001060 was highly expressed in OS tumor tissues. In this work, we identified that high level expression of circ_0001060 was significantly associated with late clinical stage, larger tumor volume, higher frequency of metastasis, and poor prognosis in OS patients. Furthermore, we confirmed that silencing circ_0001060 inhibited the proliferation and migration of OS cell. Using bioinformatics analysis, we built three circRNA-miRNA-mRNA regulatory modules (circ_0001060-miR-203a-5p-TRIM21, circ_0001060-miR-208b-5p-MAP3K5, and circ_0001060-miR-203a-5p-PRKX), suggesting that these signaling axes may be involved in the inhibitory effect of circ_0001060 on OS. To sum up, circ_0001060 is a novel tumor biomarker for OS as well as a potential therapeutic target.

UPLC/Q-TOF-MS-based Metabolomics Study of the Antiosteoporosis Effects of Vaccarin in Ovariectomized Mice.

Osteoporosis is a systemic and metabolic bone disease that usually occurs in postmenopausal women, which mainly manifests as bone loss and increased bone fragility that both facilitate fracture. However, few drugs for osteoporosis have shown good efficacy and limited side effects. Vaccarin has demonstrated its antiosteoporosis effects by inhibiting the formation and osteolytic activities of osteoclasts in our previous investigation. In this study, multivariate statistical analysis and ultrahigh-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry were used to analyze the serum metabolites of ovariectomized mice treated with or without vaccarin. As a result, 9 serum metabolites were identified as biomarkers. The metabolic levels of 3 crucial biomarkers, namely, lysophosphatidylcholine [22 : 6, (4Z, 7Z, 10Z, 13Z, 16Z, 19Z)], 1-linoleoylglycerophosphocholine and 1-palmitoyl-Sn-glycero-3-phosphocholine, that were correlated with glycerophospholipid metabolism increased and then decreased significantly after vaccarin treatment. Molecular docking analysis and osteoclasts differentiation experiment further revealed that vaccarin may bind with phospholipase A2 and downregulated its activity to reduce the osteoclastogenesis. Therefore, the occurrence of osteoporosis is closely related with glycerophospholipid metabolism disorders, and vaccarin exerts antiosteoporosis effects by reducing the levels of glycerophospholipid metabolites.

Corrigendum: Single-cell transcriptomics reveals the complexity of the tumor microenvironment of treatment-naive osteosarcoma.

[This corrects the article DOI: 10.3389/fonc.2021.709210.].

Single-Cell Transcriptome Analysis Reveals Paraspeckles Expression in Osteosarcoma Tissues.

Nuclear paraspeckles are subnuclear bodies contracted by nuclear-enriched abundant transcript 1 (NEAT1) long non-coding RNA, localised in the interchromatin space of mammalian cell nuclei. Paraspeckles have been critically involved in tumour progression, metastasis and chemoresistance. To this date, there are limited findings to suggest that paraspeckles, NEAT1 and heterogeneous nuclear ribonucleoproteins (hnRNPs) directly or indirectly play roles in osteosarcoma progression. Herein, we analysed NEAT1, paraspeckle proteins (SFPQ, PSPC1 and NONO) and hnRNP members (HNRNPK, HNRNPM, HNRNPR and HNRNPD) gene expression in 6 osteosarcoma tumour tissues using the single-cell RNA-sequencing method. The normalised data highlighted that the paraspeckles transcripts were highly abundant in osteoblastic OS cells, except NEAT1, which was highly expressed in myeloid cell 1 and 2 subpopulations.