The genetic background determines material-induced bone formation through the macrophage-osteoclast axis.

Osteoinductive materials are characterized by their ability to induce bone formation in ectopic sites. Thus, osteoinductive materials hold promising potential for repairing bone defects. However, the mechanism of material-induced bone formation remains unknown, which limits the design of highly potent osteoinductive materials. Here, we demonstrated a genetic background link among macrophage polarization, osteoclastogenesis and material-induced bone formation. The intramuscular implantation of an osteoinductive material in FVB/NCrl (FVB) mice resulted in more M2 macrophages at week 1, more osteoclasts at week 2 and increased bone formation after week 4 compared with the results obtained in C57BL/6JOlaHsd (C57) mice. Similarly, in vitro, with a greater potential to form M2 macrophages, monocytes derived from FVB mice formed more osteoclasts than those derived from C57 mice. A transcriptomic analysis identified Csf1, Cxcr4 and Tgfbr2 as the main genes controlling macrophage-osteoclast coupling, which were further confirmed by related inhibitors. With such coupling, macrophage polarization and osteoclast formation of monocytes in vitro successfully predicted in vivo bone formation in four other mouse strains. Considering material-induced bone formation as an example of acquired heterotopic bone formation, the current findings shed a light on precision medicine for both bone regeneration and the treatment of pathological heterotopic bone formation.

Estimation of ground-level O3 concentration in the Yangtze River Delta region based on a high-performance spatiotemporal model MixNet.

In recent years, the escalating ozone (O3) concentration has significantly damaged human health. The machine learning models are widely used to estimate ground-level O3 concentrations, but the spatial and temporal features in the data are less considered. To address the issue, this study proposed a novel framework named MixNet to estimate daily O3 concentration from 2020 to 2021 over the Yangtze River Delta. The MixNet utilized image convolution to extract the potential spatial information related to O3 fully. The temporal features were extracted by a Long Short-Term Memory (LSTM). A U-Net, a new jump connection method with an attention mechanism and residual blocks, facilitated a more comprehensive extraction of spatial features in the data. The extracted temporal and spatial features were fused to estimate ground-level O3. Meanwhile, a novel training method was proposed to enhance the accuracy of MixNet. The daily mean O3 maps have high validation results in comparison with ground-level O3 measurement, with R2 (RMSE) of 0.903 (14.511 µg/m3) for sample-based validation, 0.831 (19.036 µg/m3) for site-based validation, and 0.712 (25.108 µg/m3) for time-based validation. The season-average maps indicate that O3 concentration is summer > autumn > spring > winter. The highest value was 137.41 µg/m3 in the summer of 2021 over the Yangtze River Delta urban agglomeration, and the lowest value was 52.73 µg/m3 in winter 2020. The MixNet showed better performance compared with other models, and thus the "point-plane image thinking" will contribute to future studies in developing better methods to estimate atmospheric pollutants.

Hypoxia Drives Material-Induced Heterotopic Bone Formation by Enhancing Osteoclastogenesis via M2/Lipid-Loaded Macrophage Axis.

Heterotopic ossification (HO) is a double-edged sword. Pathological HO presents as an undesired clinical complication, whereas controlled heterotopic bone formation by synthetic osteoinductive materials shows promising therapeutic potentials for bone regeneration. However, the mechanism of material-induced heterotopic bone formation remains largely unknown. Early acquired HO being usually accompanied by severe tissue hypoxia prompts the hypothesis that hypoxia caused by the implantation coordinates serial cellular events and ultimately induces heterotopic bone formation in osteoinductive materials. The data presented herein shows a link between hypoxia, macrophage polarization to M2, osteoclastogenesis, and material-induced bone formation. Hypoxia inducible factor-1α (HIF-1α), a crucial mediator of cellular responses to hypoxia, is highly expressed in an osteoinductive calcium phosphate ceramic (CaP) during the early phase of implantation, while pharmacological inhibition of HIF-1α significantly inhibits M2 macrophage, subsequent osteoclast, and material-induced bone formation. Similarly, in vitro, hypoxia enhances M2 macrophage and osteoclast formation. Osteoclast-conditioned medium enhances osteogenic differentiation of mesenchymal stem cells, such enhancement disappears with the presence of HIF-1α inhibitor. Furthermore, metabolomics analysis reveals that hypoxia enhances osteoclastogenesis via the axis of M2/lipid-loaded macrophages. The current findings shed new light on the mechanism of HO and favor the design of more potent osteoinductive materials for bone regeneration.

Research Progress of Metabolomics Techniques Combined with Machine Learning Algorithm in Wound Age Estimation.

Wound age estimation is the core content in the practice of forensic medicine. Accurate estimation of wound age is a scientific question that needs to be urgently solved by forensic scientists at home and abroad. Metabolomics techniques can effectively detect endogenous metabolites produced by internal or external stimulating factors and describe the dynamic changes of metabolites in vivo. It has the advantages of strong operability, high detection efficiency and accurate quantitative results. Machine learning algorithm has special advantages in processing high-dimensional data sets, which can effectively mine biological information and truly reflect the physiological, disease or injury state of the body. It is a new technical means for efficiently processing high-throughput big data. This paper reviews the status and advantages of metabolomic techniques combined with machine learning algorithm in the research of wound age estimation, and provides new ideas for this research.

Efficient bone regeneration of BMP9-stimulated human periodontal ligament stem cells (hPDLSCs) in decellularized bone matrix (DBM) constructs to model maxillofacial intrabony defect repair.

BACKGROUND: BMP9-stimulated DPSCs, SCAPs and PDLSCs are effective candidates for repairing maxillofacial bone defects in tissue engineering, while the most suitable seed cell source among these three hDMSCs and the optimal combination of most suitable type of hDMSCs and BMP9 have rarely been explored. Moreover, the orthotopic maxillofacial bone defect model should be valuable but laborious and time-consuming to evaluate various candidates for bone regeneration. Thus, inspired from the maxillofacial bone defects and the traditional in vivo ectopic systems, we developed an intrabony defect repair model to recapitulate the healing events of orthotopic maxillofacial bone defect repair and further explore the optimized combinations of most suitable hDMSCs and BMP9 for bone defect repair based on this modified ectopic system. METHODS: Intrabony defect repair model was developed by using decellularized bone matrix (DBM) constructs prepared from the cancellous part of porcine lumbar vertebral body. We implanted DBM constructs subcutaneously on the flank of each male NU/NU athymic nude mouse, followed by directly injecting the cell suspension of different combinations of hDMSCs and BMP9 into the central hollow area of the constructs 7 days later. Then, the quality of the bony mass, including bone volume fraction (BV/TV), radiographic density (in Hounsfield units (HU)) and the height of newly formed bone, was measured by micro-CT. Furthermore, the H&E staining and immunohistochemical staining were performed to exam new bone and new blood vessel formation in DBM constructs. RESULTS: BMP9-stimulated periodontal ligament stem cells (PDLSCs) exhibited the most effective bone regeneration among the three types of hDMSCs in DBM constructs. Furthermore, an optimal dose of PDLSCs with a specific extent of BMP9 stimulation was confirmed for efficacious new bone and new blood vessel formation in DBM constructs. CONCLUSIONS: The reported intrabony defect repair model can be used to identify optimized combinations of suitable seed cells and biological factors for bone defect repair and subsequent development of efficacious bone tissue engineering therapies.

Estimating bloodstain formation time by quantitative analysis of mtDNA degradation.

The estimation of bloodstain formation time is still an unsolved problem in forensic science and lacks accurate quantitative methods. Whether DNA can be adopted to estimate bloodstain formation time is still controversial, and there is no study to confirm the potential of mtDNA markers. To address these issues, a triple quantification method based on the ratio of mtDNA fragments of different lengths of COⅠ (mitochondrially encoded cytochrome c oxidase Ⅰ) for estimating bloodstain formation time was established. A total of 152 samples (140 old samples, 12 fresh samples) were collected and tested, and the absolute copies of different-sized fragments of COⅠ (304 bp, 120 bp, 41 bp) in all samples were quantified by SYBR Green real-time qPCR. The natural logarithms of two copy number ratios (304 bp/41 bp, 120 bp/41 bp) of COⅠ in old samples were calculated, which were used as degradation indexes to evaluate the degradation degree of mtDNA. The 140 old human blood samples from 1 to 14 years of storage were accumulated from casework of forensic practice to establish the method of estimating bloodstain formation time and used to analyze the impact of gender factors on the two degradation indexes, and 10 animal samples and 2 fresh human samples were collected to verify the human specificity of the method. There was a high correlation between degradation indexes and bloodstain formation time (the absolute values of correlation coefficients of these two degradation indexes were 0.901 and 0.758 respectively). A method with triple quantification and dual indexes estimating bloodstain formation timewas successfully established, which was highly human-specific. There was no statistically significant difference in degradation indexes between different gender samples (P > 0.05). This study confirmed that mtDNA can be utilized to estimate bloodstain formation time, which provides a new solution to the forensic problem of estimating the time of bloodstain formation.

PDIA4 promotes glioblastoma progression via the PI3K/AKT/m-TOR pathway.

Protein disulfide isomerase A4 (PDIA4) is highly expressed in clear cell ovarian carcinoma and lung cancer. Through analysis of TCGA database and CGGA database, we noted that PDIA4 is a key promotor of glioblastoma (GBM). However, the detailed role and molecular mechanism of PDIA4 in GBM remain unclear. In this study, the expression pattern and biological role of PDIA4 in GBM was investigated. PDIA4 was overexpressed in GBM tumor samples and cell lines and positively correlated with pathological grades in glioma patients. In addition, downregulation of PDIA4 promoted apoptosis and inhibited proliferation of GBM. Meanwhile, there was a concurrent decrease in aerobic glycolysis metabolites. Mechanistically, PDIA4 downregulation promoted the apoptosis of GBM cells by increased the expression of apoptosis pathway proteins (caspase 3, caspase 9 and Bax). Downregulation of PDIA4 decreased energy demand and inhibited GBM growth in vitro and in vivo. Besides, such effect also inhibited the PI3K/AKT/m-TOR pathway by inhibiting protein phosphorylation levels of PI3K, AKT and m-TOR. After addition of PI3K/AKT/mTOR pathway activator 740Y-P, the effect of PDIA4 knockdown on GBM was reversed. Therefore, we believe that PDIA4 regulates the proliferation via activating the PI3K/AKT/m-TOR pathway and suppression of apoptosis in glioblastoma. It could be used as a potential target for the treatment of GBM.

Perfusion CT detects alterations in local cerebral flow of glioma related to IDH, MGMT and TERT status.

BACKGROUND: The aim of this study was to investigate the relationship between tumor biology and values of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), time to peak (TTP), permeability surface (PS) of tumor in patients with glioma. METHODS: Forty-six patients with glioma were involved in the study. Histopathologic and molecular pathology diagnoses were obtained by tumor resection, and all patients accepted perfusion computed tomography (PCT) before operation. Regions of interests were placed manually at tumor and contralateral normal-appearing thalamus. The parameters of tumor were divided by those of contralateral normal-appearing thalamus to normalize at tumor (relative [r] CBV, rCBF, rMTT, rTTP, rPS). The relationships of the parameters, world health organization (WHO) grade, molecular pathological findings were analysed. RESULTS: The rCBV, rMTT and rPS of patients are positively related to the pathological classification (P < 0.05). The values of rCBV and rPS in IDH mutated patients were lower than those IDH wild-type. The values of rCBF in patients with MGMT methylation were lower than those MGMT unmethylation (P < 0.05). The MVD of TERT wild-type group was lower than TERT mutated group (P < 0.05). The values of rCBV were significant difference in the four molecular groups divided by the combined IDH/TERT classification (P < 0.05). The progression free survival (PFS) and overall survival (OS) were significant difference in the four molecular groups divided by the combined IDH/TERT classification (P < 0.05). CONCLUSIONS: Our study introduces and supports the changes of glioma flow perfusion may be closely related to its biological characteristics.

Association Between Oral Microbiota and Human Brain Glioma Grade: A Case-Control Study.

Gliomas are the most prevalent form of primary malignant brain tumor, which currently have no effective treatments. Evidence from human studies has indicated that oral microbiota is closely related to cancers; however, whether oral microbiota plays a role in glioma malignancy remains unclear. The present study aimed to investigate the association between oral microbiota and grade of glioma and examine the relationship between malignancy-related oral microbial features and the isocitrate dehydrogenase 1 (IDH1) mutation in glioma. High-grade glioma (HGG; n=23) patients, low-grade glioma (LGG; n=12) patients, and healthy control (HCs; n=24) participants were recruited for this case-control study. Saliva samples were collected and analyzed for 16S ribosomal RNA (rRNA) sequencing. We found that the shift in oral microbiota ß-diversity was associated with high-grade glioma (p=0.01). The phylum Patescibacteria was inversely associated with glioma grade (LGG and HC: p=0.035; HGG and HC: p<0.01). The genera Capnocytophaga (LGG and HC: p=0.043; HGG and HC: p<0.01) and Leptotrichia (LGG and HC: p=0.044; HGG and HC: p<0.01) were inversely associated with glioma grades. The genera Bergeyella and Capnocytophaga were significantly more positively correlated with the IDH1 mutation in gliomas when compared with the IDH1-wild-type group. We further identified five oral microbial features (Capnocytophaga Porphyromonas, Haemophilus, Leptotrichia, and TM7x) that accurately discriminated HGG from LGG (area under the curve [AUC]: 0.63, 95% confidence interval [CI]: 0.44-0.83) and HCs (AUC: 0.79, 95% CI: 0.68-0.92). The functional prediction analysis of oral bacterial communities showed that genes involved in cell adhesion molecules (p<0.001), extracellular matrix molecule-receptor interaction (p<0.001), focal adhesion (p<0.001), and regulation of actin cytoskeleton (p<0.001) were associated with glioma grades, and some microbial gene functions involving lipid metabolism and the adenosine 5'-monophosphate-activated protein kinase signaling pathway were significantly more enriched in IDH1 mutant gliomas than compared with the IDH1-wild-type gliomas. In conclusion, our work revealed oral microbiota features and gene functions that were associated with glioma malignancy and the IDH1 mutation in glioma.

Special AT-rich sequence-binding protein 2 (Satb2) synergizes with Bmp9 and is essential for osteo/odontogenic differentiation of mouse incisor mesenchymal stem cells.

OBJECTIVES: Mouse incisor mesenchymal stem cells (MSCs) have self-renewal ability and osteo/odontogenic differentiation potential. However, the mechanism controlling the continuous self-renewal and osteo/odontogenic differentiation of mouse incisor MSCs remains unclear. Special AT-rich sequence-binding protein 2 (SATB2) positively regulates craniofacial patterning, bone development and regeneration, whereas SATB2 deletion or mutation leads to craniomaxillofacial dysplasia and delayed tooth and root development, similar to bone morphogenetic protein (BMP) loss-of-function phenotypes. However, the detailed mechanism underlying the SATB2 role in odontogenic MSCs is poorly understood. The aim of this study was to investigate whether SATB2 can regulate self-renewal and osteo/odontogenic differentiation of odontogenic MSCs. MATERIALS AND METHODS: Satb2 expression was detected in the rapidly renewing mouse incisor mesenchyme by immunofluorescence staining, quantitative RT-PCR and Western blot analysis. Ad-Satb2 and Ad-siSatb2 were constructed to evaluate the effect of Satb2 on odontogenic MSCs self-renewal and osteo/odontogenic differentiation properties and the potential role of Satb2 with the osteogenic factor bone morphogenetic protein 9 (Bmp9) in vitro and in vivo. RESULTS: Satb2 was found to be expressed in mesenchymal cells and pre-odontoblasts/odontoblasts. We further discovered that Satb2 effectively enhances mouse incisor MSCs self-renewal. Satb2 acted synergistically with the potent osteogenic factor Bmp9 in inducing osteo/odontogenic differentiation of mouse incisor MSCs in vitro and in vivo. CONCLUSIONS: Satb2 promotes self-renewal and osteo/odontogenic differentiation of mouse incisor MSCs. Thus, Satb2 can cooperate with Bmp9 as a new efficacious bio-factor for osteogenic regeneration and tooth engineering.

Bubble Melt Electrospinning for Production of Polymer Microfibers.

In this paper, we report an interesting bubble melt electrospinning (e-spinning) to produce polymer microfibers. Usually, melt e-spinning for fabricating ultrafine fibers needs "Taylor cone", which is formed on the tip of the spinneret. The spinneret is also the bottleneck for mass production in melt e-spinning. In this work, a metal needle-free method was tried in the melt e-spinning process. The "Taylor cone" was formed on the surface of the broken polymer melt bubble, which was produced by an airflow. With the applied voltage ranging from 18 to 25 kV, the heating temperature was about 210⁻250 °C, and polyurethane (TPU) and polylactic acid (PLA) microfibers were successfully fabricated by this new melt e-spinning technique. During the melt e-spinning process, polymer melt jets ejected from the burst bubbles could be observed with a high-speed camera. Then, polymer microfibers could be obtained on the grounded collector. The fiber diameter ranged from 45 down to 5 µm. The results indicate that bubble melt e-spinning may be a promising method for needleless production in melt e-spinning.

Electrospun nanofibers for wound healing.

Electrospinning has been widely used as a nanofiber fabrication technique. Its simple process, cost effectiveness and versatility have appealed to materials scientists globally. Pristine polymeric nanofibers or composite nanofibers with dissimilar morphologies and multidimensional assemblies ranging from one dimension (1D) to three dimensions (3D) can be obtained from electrospinning. Critically, these as-prepared nanofibers possessing high surface area to volume ratio, tunable porosity and facile surface functionalization present numerous possibilities for applications, particularly in biomedical field. This review gives us an overview of some recent advances of electrospinning-based nanomaterials in biomedical applications such as antibacterial mats, patches for rapid hemostasis, wound dressings, drug delivery systems, as well as tissue engineering. We further highlight the current challenges and future perspectives of electrospinning-based nanomaterials in the field of biomedicine.

Multi-boundary cardiac data visualization based on multidimensional transfer function with ray distance.

A crucial role during the implementation of volume visualization is to identify the optimal transfer function, since the vital information and structure can be highlighted and revealed. The boundary of the volume is shared by respective portion of the two materials formed out of it, which causes undesirable thickening and ambiguity of the boundary explored via traditional LH (Low and High) histogram. To address this issue, initially a modified LH histogram construction method is introduced to intuitively and conveniently visualize cardiac volume for user interaction. Subsequently, the f-LH histogram is presented to further identify and visualize each portion of the boundary accurately. An appropriate multidimensional transfer function generation is proposed by using variables in f-LH space and spatial information, for visualizing the multi-boundary cardiac volume data.

Moving posttranslational modifications forward to biosynthesize the glycosylated thiopeptide nocathiacin I in Nocardia sp. ATCC202099.

Characterization of the biosynthetic gene cluster of glycosylated antibiotic nocathiacin I (NOC-I) here adds new insights to thiopeptide biosynthesis, showing the NOC-specific tailoring and unusual sugar formation. NOC-I biosynthesis shares the paradigm for forming a common thiopeptide core and the generality for converting to an e series member, as that of the parent compound nosiheptide (NOS). This may permit the production of NOC-I in the genetically amenable, NOS-producing strain by building NOC-specific genes for pathway engineering.