A nomogram prediction of gingival recession in mandibular incisors of orthodontic-orthognathic treated skeletal class III malocclusion with or without PAOO: A retrospective cohort study.

Background: To assess the alterations in gingival thickness and the occurrence gingival recession subsequent to orthodontic-orthognathic treatment of mandibular incisors in skeletal Class III and identify risk factors associated with gingival recession. Methods: In this retrospective cohort study, we enrolled 33 patients exhibiting skeletal Class III malocclusion, totaling 131 mandibular incisors, who were undergoing orthodontic- orthognathic treatment that did not involve extraction of mandibular teeth. The subjects were categorized into surgery group (S; n = 17; ANB = -5.55 ± 3.26; IOFTN = 4.60 ± 0.51, scores ranging: 4.3-5.3) and non-surgery group (NS; n = 16; ANB = -3.00 ± 4.08; IOFTN = 4.63 ± 0.50, scores ranging: 4.3-5.4), based on if they had history of Periodontally Accelerated Osteogenic Orthodontics surgery (S) or not (NS). Patients in S group received orthognathic surgery about 1-1.5 years after Periodontally Accelerated Osteogenic Orthodontics surgery. Alterations in gingival thickness, gingival recession, and keratinized gingival width were compared before and after orthodontic-orthognathic treatment. Logistic regression analysis was used to construct a gingival recession prediction model and draw nomograms. Results: After orthodontic-orthognathic treatment, the gingival thickness and keratinized gingival width in NS group decreased by 0.15 ± 0.21 mm and 0.74 ± 0.91 mm, whereas those in the S group increased by 0.32 ± 0.28 mm and 2.09 ± 1.51 mm (P < 0.05). After orthodontic-orthognathic, the percentage of gingival recession increased by 47.62 % in NS group, which was 14.77 times that of S group (P < 0.05). Multivariate regression analysis indicated that skeletal Class III patients with a gingival thickness below 0.72 mm, an alveolar bone height exceeding 2.36 mm, and an alveolar bone thickness under 0.45 mm might be at elevated risk for developing gingival recession following orthodontic - orthognathic therapy. Conclusions: Drawing on the findings of our investigation, we concluded the risk of gingival recession of mandibular anterior teeth increased after orthodontic-orthognathic treatment in skeletal Class III, whereas Periodontally Accelerated Osteogenic Orthodontics surgery could significantly improve the periodontal phenotype and prevent gingival recession.

Dual External Field Strategy in Regulating the Superhalogen Characteristics of the Non-Noble Metal Constituted Tantalum Oxide Clusters.

The identification of the non-noble metal constituted TaO cluster as a potential analogue to the noble metal Au is significant for the development of tailored materials. It leverages the superatom concept to engineer properties with precision. However, the impact of incrementally integrating TaO units on the electronic configurations and properties within larger TaO-based clusters remains to be elucidated. By employing the density functional theory calculations, the global minima and low-lying isomers of the TanOn (n = 2-5) clusters were determined, and their structural evolution was disclosed. In the cluster series, Ta5O5 was found to possess the highest electron affinity (EA) with a value of 2.14 eV, based on which a dual external field (DEF) strategy was applied to regulate the electronic property of the cluster. Initially, the electron-withdrawing CO ligand was affixed to Ta5O5, followed by the application of an oriented external electric field (OEEF). The CO ligation was found to be able to enhance the Ta5O5 cluster's electron capture capability by adjusting its electron energy levels, with the EA of Ta5O5(CO)4 peaking at 2.58 eV. Subsequently, the introduction of OEEF further elevated the EA of the CO-ligated cluster. Notably, OEEF, when applied along the +x axis, was observed to sharply increase the EA to 3.26 eV, meeting the criteria for superhalogens. The enhancement of EA in response to OEEF intensity can be quantified as a functional relationship. This finding highlights the advantage of OEEF over conventional methods, demonstrating its capacity for precise and continuous modulation of cluster EAs. Consequently, this research has adeptly transformed tantalum oxide clusters into superhalogen structures, underscoring the effectiveness of the DEF strategy in augmenting cluster EAs and its promise as a viable tool for the creation of superhalogens.

Topological Organization of the Brain Network in Patients with Primary Angle-closure Glaucoma Through Graph Theory Analysis.

Primary angle-closure glaucoma (PACG) is a sight-threatening eye condition that leads to irreversible blindness. While past neuroimaging research has identified abnormal brain function in PACG patients, the relationship between PACG and alterations in brain functional networks has yet to be explored. This study seeks to examine the influence of PACG on brain networks, aiming to advance knowledge of its neurobiological processes for better diagnostic and therapeutic approaches utilizing graph theory analysis. A cohort of 44 primary angle-closure glaucoma (PACG) patients and 44 healthy controls participated in this study. Functional brain networks were constructed using fMRI data and the Automated Anatomical Labeling 90 template. Subsequently, graph theory analysis was employed to evaluate global metrics, nodal metrics, modular organization, and network-based statistics (NBS), enabling a comparative analysis between PACG patients and the control group. The analysis of global metrics, including small-worldness and network efficiency, did not exhibit significant differences between the two groups. However, PACG patients displayed elevated nodal metrics, such as centrality and efficiency, in the left frontal superior medial, right frontal superior medial, and right posterior central brain regions, along with reduced values in the right temporal superior gyrus region compared to healthy controls. Furthermore, Module 5 showed notable disparities in intra-module connectivity, while Module 1 demonstrated substantial differences in inter-module connectivity with both Module 7 and Module 8. Noteworthy, the NBS analysis unveiled a significantly altered network when comparing the PACG and healthy control groups. The study proposes that PACG patients demonstrate variations in nodal metrics and modularity within functional brain networks, particularly affecting the prefrontal, occipital, and temporal lobes, along with cerebellar regions. However, an analysis of global metrics suggests that the overall connectivity patterns of the entire brain network remain unaltered in PACG patients. These results have the potential to serve as early diagnostic and differential markers for PACG, and interventions focusing on brain regions with high degree centrality and nodal efficiency could aid in optimizing therapeutic approaches.

New G-Triplex DNA Dramatically Activates the Fluorescence of Thioflavin T and Acts as a Turn-On Fluorescent Sensor for Uracil-DNA Glycosylase Activity Detection.

G-triplexes are G-rich oligonucleotides composed of three G-tracts and have absorbed much attention due to their potential biological functions and attractive performance in biosensing. Through the optimization of loop compositions, DNA lengths, and 5'-flanking bases of G-rich sequences, a new stable G-triplex sequence with 14 bases (G3-F15) was discovered to dramatically activate the fluorescence of Thioflavin T (ThT), a water-soluble fluorogenic dye. The fluorescence enhancement of ThT after binding with G3-F15 reached 3200 times, which was the strongest one by far among all of the G-rich sequences. The conformations of G3-F15 and G3-F15/ThT were studied by circular dichroism. The thermal stability measurements indicated that G3-F15 was a highly stable G-triplex structure. The conformations of G3-F15 and G3-F15/ThT in the presence of different metal cations were studied thoroughly by fluorescent spectroscopy, circular dichroism, and nuclear magnetic resonance. Furthermore, using the G3-F15/ThT complex as a fluorescent probe, a robust and simple turn-on fluorescent sensor for uracil-DNA glycosylase activity was developed. This study proposes a new systematic strategy to explore new functional G-rich sequences and their ligands, which will promote their applications in diagnosis, therapy, and biosensing.

[Establishment and Evaluation Strategy of an in vitro Cell Model of Bone Marrow Microenvironment Injury in Mouse Acute Graft-Versus-Host Disease].

OBJECTIVE: To establish a mesenchymal stem cell（MSC）-based in vitro cell model for the evaluation of mouse bone marrow acute graft-versus-host disease (aGVHD). METHODS: Female C57BL/6N mice aged 6-8 weeks were used as bone marrow and lymphocyte donors, and female BALB/c mice aged 6-8 weeks were used as aGVHD recipients. The recipient mouse received a lethal dose (8.0 Gy,72.76 cGy/min) of total body γ irradiation, and injected with donor mouse derived bone marrow cells (1×107/mouse) in 6-8 hours post irradiation to establish a bone marrow transplantation (BMT) mouse model (n=20). In addition, the recipient mice received a lethal dose (8.0 Gy,72.76 cGy/min) of total body γ irradiation, and injected with donor mouse derived bone marrow cells (1×107/mouse) and spleen lymphocytes (2×106/mouse) in 6-8 hours post irradiation to establish a mouse aGVHD model (n=20). On the day 7 after modeling, the recipient mice were anesthetized and the blood was harvested post eyeball enucleation. The serum was collected by centrifugation. Mouse MSCs were isolated and cultured with the addition of 2%, 5%, and 10% recipient serum from BMT group or aGVHD group respectively. The colony-forming unit-fibroblast（CFU-F) experiment was performed to evaluate the potential effects of serums on the self-renewal ability of MSC. The expression of CD29 and CD105 of MSC was evaluated by immunofluorescence staining. In addition, the expression of self-renewal-related genes including Oct-4, Sox-2, and Nanog in MSC was detected by real-time fluorescence quantitative PCR（RT-qPCR). RESULTS: We successfully established an in vitro cell model that could mimic the bone marrow microenvironment damage of the mouse with aGVHD. CFU-F assay showed that, on day 7 after the culture, compared with the BMT group, MSC colony formation ability of aGVHD serum concentrations groups of 2% and 5% was significantly reduced （P < 0．05）; after the culture, at day 14, compared with the BMT group, MSC colony formation ability in different aGVHD serum concentration was significantly reduced （P < 0．05）. The immunofluorescence staining showed that, compared with the BMT group, the proportion of MSC surface molecules CD29+ and CD105+ cells was significantly dereased in the aGVHD serum concentration group (P < 0.05), the most significant difference was at a serum concentration of 10% （P < 0．001, P < 0.01）. The results of RT-qPCR detection showed that the expression of the MSC self-renewal-related genes Oct-4, Sox-2, and Nanog was decreased, the most significant difference was observed at an aGVHD serum concentration of 10% （P < 0.01,P < 0．001,P < 0．001）. CONCLUSION: By co-culturing different concentrations of mouse aGVHD serum and mouse MSC, we found that the addition of mouse aGVHD serum at different concentrations impaired the MSC self-renewal ability, which providing a new tool for the field of aGVHD bone marrow microenvironment damage.

Microgel-based carriers enhance skeletal stem cell reprogramming towards immunomodulatory phenotype in osteoarthritic therapy.

Skeletal stem cells (SSC) have gained attentions as candidates for the treatment of osteoarthritis due to their osteochondrogenic capacity. However, the immunomodulatory properties of SSC, especially under delivery operations, have been largely ignored. In the study, we found that Pdpn+ and Grem1+ SSC subpopulations owned immunoregulatory potential, and the single-cell RNA sequencing (scRNA-seq) data suggested that the mechanical activation of microgel carriers on SSC induced the generation of Pdpn+Grem1+Ptgs2+ SSC subpopulation, which was potent at suppressing macrophage inflammation. The microgel carriers promoted the YAP nuclear translocation, and the activated YAP protein was necessary for the increased expression of Ptgs2 and PGE2 in microgels-delivered SSC, which further suppressed the expression of TNF-ɑ, IL-1ß and promoted the expression of IL-10 in macrophages. SSC delivered with microgels yielded better preventive effects on articular lesions and macrophage activation in osteoarthritic rats than SSC without microgels. Chemically blocking the YAP and Ptgs2 in microgels-delivered SSC partially abolished the enhanced protection on articular tissues and suppression on osteoarthritic macrophages. Moreover, microgel carriers significantly prolonged SSC retention time in vivo without increasing SSC implanting into osteoarthritic joints. Together, our study demonstrated that microgel carriers enhanced SSC reprogramming towards immunomodulatory phenotype to regulate macrophage phenotype transformation for effectively osteoarthritic therapy by promoting YAP protein translocation into nucleus. The study not only complement and perfect the immunological mechanisms of SSC-based therapy at the single-cell level, but also provide new insight for microgel carriers in stem cell-based therapy.

Recent Progress in Phage-Based Nanoplatforms for Tumor Therapy.

Nanodrug delivery systems have demonstrated a great potential for tumor therapy with the development of nanotechnology. Nonetheless, traditional drug delivery systems are faced with issues such as complex synthetic procedures, low reproducibility, nonspecific distribution, impenetrability of biological barrier, systemic toxicity, etc. In recent years, phage-based nanoplatforms have attracted increasing attention in tumor treatment for their regular structure, fantastic carrying property, high transduction efficiency and biosafety. Notably, therapeutic or targeting peptides can be expressed on the surface of the phages through phage display technology, enabling the phage vectors to possess multifunctions. As a result, the drug delivery efficiency on tumor will be vastly improved, thereby enhancing the therapeutic efficacy while reducing the side effects on normal tissues. Moreover, phages can overcome the hindrance of biofilm barrier to elicit antitumor effects, which exhibit great advantages compared with traditional synthetic drug delivery systems. Herein, this review not only summarizes the structure and biology of the phages, but also presents their potential as prominent nanoplatforms against tumor in different pathways to inspire the development of effective nanomedicine.

DNA N6-methyladenine methylase N6AMT1 controls neuropathic pain through epigenetically modifying Kcnj16 in dorsal horn neurons.

ABSTRACT: Nerve injury-induced aberrant changes in gene expression in spinal dorsal horn neurons are critical for the genesis of neuropathic pain. N6-methyladenine (m 6 A) modification of DNA represents an additional layer of gene regulation. Here, we report that peripheral nerve injury significantly decreased the level of m 6 A-specific DNA methyltransferase 1 ( N6amt1 ) in dorsal horn neurons. This decrease was attributed, at least partly, to a reduction in transcription factor Nr2f6 . Rescuing the decrease in N6amt1 reversed the loss of m 6 A at the promoter for inwardly rectifying potassium channel subfamily J member 16 ( Kcnj16 ), mitigating the nerve injury-induced upregulation of Kcnj16 expression in the dorsal horn and alleviating neuropathic pain hypersensitivities. Conversely, mimicking the downregulation of N6amt1 in naive mice erased DNA m 6 A at the Kcnj16 promoter, elevated Kcnj16 expression, and led to neuropathic pain-like behaviors. Therefore, decreased N6amt1 caused by NR2F6 is required for neuropathic pain, likely through its regulation of m 6 A-controlled KCNJ16 in dorsal horn neurons, suggesting that DNA m 6 A modification may be a potential new target for analgesic and treatment strategies.

TNFAIP3 Derived from Skeletal Stem Cells Alleviated Rat Osteoarthritis by Inhibiting the Necroptosis of Subchondral Osteoblasts.

Recent investigations have shown that the necroptosis of tissue cells in joints is important in the development of osteoarthritis (OA). This study aimed to investigate the potential effects of exogenous skeletal stem cells (SSCs) on the necroptosis of subchondral osteoblasts in OA. Human SSCs and subchondral osteoblasts isolated from human tibia plateaus were used for Western blotting, real-time PCR, RNA sequencing, gene editing, and necroptosis detection assays. In addition, the rat anterior cruciate ligament transection OA model was used to evaluate the effects of SSCs on osteoblast necroptosis in vivo. The micro-CT and pathological data showed that intra-articular injections of SSCs significantly improved the microarchitecture of subchondral trabecular bones in OA rats. Additionally, SSCs inhibited the necroptosis of subchondral osteoblasts in OA rats and necroptotic cell models. The results of bulk RNA sequencing of SSCs stimulated or not by tumor necrosis factor α suggested a correlation of SSCs-derived tumor necrosis factor α-induced protein 3 (TNFAIP3) and cell necroptosis. Furthermore, TNFAIP3-derived from SSCs contributed to the inhibition of the subchondral osteoblast necroptosis in vivo and in vitro. Moreover, the intra-articular injections of TNFAIP3-overexpressing SSCs further improved the subchondral trabecular bone remodeling of OA rats. Thus, we report that TNFAIP3 from SSCs contributed to the suppression of the subchondral osteoblast necroptosis, which suggests that necroptotic subchondral osteoblasts in joints may be possible targets to treat OA by stem cell therapy.

[The Advance of the HSCT Evaluation at Single-Cell Scale --Review].

Hematopoietic stem cell transplantation (HSCT) is one of the effective options for the treatment of irradiation-induced injury on hematopoiesis, malignant hematological diseases, and numerous benign severe hematopathy. However, the cellular composition of the graft for HSCT, as well as the significant events of transplanted HSCs in receipients including HSC homing, engraftment, differentiation, remains to be further elucidated. In recent years, with advances in single-cell techniques, the hematopoiesis has been decoding at single cell scale. In addition, single-cell RNA sequencing (scRNA-seq) has been used in the evaluation of hematopoietic dynamics post HSCT, which may be helpful to improve HSCT protocols and clinical outcomes. Hence, the recent advances of evaluating HSCT at single cell scale and the directions worthy paying attention to in the field have been reviewed briefly.

Spinal-Specific Super Enhancer in Neuropathic Pain.

Dysfunctional gene expression in nociceptive pathways plays a critical role in the development and maintenance of neuropathic pain. Super enhancers (SEs), composed of a large cluster of transcriptional enhancers, are emerging as new players in the regulation of gene expression. However, whether SEs participate in nociceptive responses remains unknown. Here, we report a spinal-specific SE (SS-SE) that regulates chronic constriction injury (CCI)-induced neuropathic pain by driving Ntmt1 and Prrx2 transcription in dorsal horn neurons. Peripheral nerve injury significantly enhanced the activity of SS-SE and increased the expression of NTMT1 and PRRX2 in the dorsal horn of male mice in a bromodomain-containing protein 4 (BRD4)-dependent manner. Both intrathecal administration of a pharmacological BRD4 inhibitor JQ1 and CRISPR-Cas9-mediated SE deletion abolished the increased NTMT1 and PRRX2 in CCI mice and attenuated their nociceptive hypersensitivities. Furthermore, knocking down Ntmt1 or Prrx2 with siRNA suppressed the injury-induced elevation of phosphorylated extracellular-signal-regulated kinase (p-ERK) and glial fibrillary acidic protein (GFAP) expression in the dorsal horn and alleviated neuropathic pain behaviors. Mimicking the increase in spinal Ntmt1 or Prrx2 in naive mice increased p-ERK and GFAP expression and led to the genesis of neuropathic pain-like behavior. These results redefine our understanding of the regulation of pain-related genes and demonstrate that BRD4-driven increases in SS-SE activity is responsible for the genesis of neuropathic pain through the governance of NTMT1 and PRRX2 expression in dorsal horn neurons. Our findings highlight the therapeutic potential of BRD4 inhibitors for the treatment of neuropathic pain.SIGNIFICANCE STATEMENT SEs drive gene expression by recruiting master transcription factors, cofactors, and RNA polymerase, but their role in the development of neuropathic pain remains unknown. Here, we report that the activity of an SS-SE, located upstream of the genes Ntmt1 and Prrx2, was elevated in the dorsal horn of mice with neuropathic pain. SS-SE contributes to the genesis of neuropathic pain by driving expression of Ntmt1 and Prrx2 Both inhibition of SS-SE with a pharmacological BRD4 inhibitor and genetic deletion of SS-SE attenuated pain hypersensitivities. This study suggests an effective and novel therapeutic strategy for neuropathic pain.

Human osteoarthritic articular cartilage stem cells suppress osteoclasts and improve subchondral bone remodeling in experimental knee osteoarthritis partially by releasing TNFAIP3.

BACKGROUND: Though articular cartilage stem cell (ACSC)-based therapies have been demonstrated to be a promising option in the treatment of diseased joints, the wide variety of cell isolation, the unknown therapeutic targets, and the incomplete understanding of the interactions of ACSCs with diseased microenvironments have limited the applications of ACSCs. METHODS: In this study, the human ACSCs have been isolated from osteoarthritic articular cartilage by advantage of selection of anatomical location, the migratory property of the cells, and the combination of traumatic injury, mechanical stimuli and enzymatic digestion. The protective effects of ACSC infusion into osteoarthritis (OA) rat knees on osteochondral tissues were evaluated using micro-CT and pathological analyses. Moreover, the regulation of ACSCs on osteoarthritic osteoclasts and the underlying mechanisms in vivo and in vitro were explored by RNA-sequencing, pathological analyses and functional gain and loss experiments. The one-way ANOVA was used in multiple group data analysis. RESULTS: The ACSCs showed typical stem cell-like characteristics including colony formation and committed osteo-chondrogenic capacity. In addition, intra-articular injection into knee joints yielded significant improvement on the abnormal subchondral bone remodeling of osteoarthritic rats. Bioinformatic and functional analysis showed that ACSCs suppressed osteoarthritic osteoclasts formation, and inflammatory joint microenvironment augmented the inhibitory effects. Further explorations demonstrated that ACSC-derived tumor necrosis factor alpha-induced protein 3 (TNFAIP3) remarkably contributed to the inhibition on osteoarhtritic osteoclasts and the improvement of abnormal subchondral bone remodeling. CONCLUSION: In summary, we have reported an easy and reproducible human ACSC isolation strategy and revealed their effects on subchondral bone remodeling in OA rats by releasing TNFAIP3 and suppressing osteoclasts in a diseased microenvironment responsive manner.

Positive responses and mechanisms of nitrifying sludge to carbon quantum dots: reactor performance, microbial behavior, and antioxidant defense.

Extensive application of carbon quantum dots (CQDs) enlarges its concentration in sewage treatment system. The response of nitrifying sludge to CQDs after long-term exposure was investigated. Results showed that CQD concentrations of 0-100 mg/L presented positive effect to enzymes involved in nitrification, accelerating NH4+-N degradation and NO2--N transformation. The oxidation rate of NO2--N was significantly improved from 3.14 to 7.91 mg/(L h) under the stress of 100 mg/L CQDs. Besides, CQDs stimulated the production of sludge biomass and kept the stability of sludge settleability. Additionally, CQDs were mainly captured by loosely bound extracellular polymeric substances, reducing aromatic-like protein. Microbes alleviated CQD stress by secreting tryptophan-like protein and polysaccharides. After few CQDs entered cells, intracellular antioxidant defense was activated. Total antioxidant capacity level was heightened at least 31%. The activities of superoxide dismutase and catalase were enhanced at relatively low and high CQD concentration levels. Hence, microbial metabolic pathways, microbial community, and nitrifying bacteria were not significantly affected by CQDs. The findings of this work provide new insight for understanding the environmental implication of CQDs in the biological treatment system.

Effect of augmented corticotomy-assisted presurgical orthodontic treatment on alveolar bone fenestration and dehiscence in skeletal class III patients.

Background/purpose: Alveolar bone fenestration and dehiscence is common in untreated patients and potentially harmful. This study was to evaluate the effect of augmented corticotomy (AC) on the prevention and treatment of alveolar bone defects in skeletal class III high-angle patients during presurgical orthodontic treatment (POT). Materials and methods: Fifty patients with skeletal Class III high-angle malocclusion were enrolled, of whom 25 patients (G1) underwent traditional POT and 25 patients (G2) received AC during POT. The alveolar bone fenestration and dehiscence around the upper and lower anterior teeth were measured by CBCT. The incidence and transition of fenestration and dehiscence in the two groups were compared by the chisquare and Mann‒Whitney rank-sum tests. Results: Before treatment (T0), the incidence of fenestration and dehiscence around the anterior teeth of all patients was 39.24% and 24.10%, respectively. After POT (T1), the incidence of fenestration in G1 and G2 was 49.83% and 25.86%, respectively, and the incidence of dehiscence in G1 and G2 was 58.08% and 32.07%, respectively. For teeth without fenestration and dehiscence at T0, more anterior teeth in G1 exhibited fenestration and dehiscence at T1 than in G2. For teeth with fenestration and dehiscence at T0, most transitions in G1 were maintained or worsened, but "cure" cases were observed in G2. After POT, the cure rates of fenestration and dehiscence in G2 were 80.95% and 91.07%, respectively. Conclusion: During the POT of skeletal Class III high-angle patients, augmented corticotomy can significantly treat and prevent alveolar bone fenestration and dehiscence around anterior teeth.

Single-cell transcriptomic analysis identifies a highly replicating Cd168+ skeletal stem/progenitor cell population in mouse long bones.

Skeletal stem/progenitor cells (SSPCs) are tissue-specific stem/progenitor cells localized within skeletons and contribute to bone development, homeostasis, and regeneration. However, the heterogeneity of SSPC populations in mouse long bones and their respective regenerative capacity remain to be further clarified. In this study, we perform integrated analysis using single-cell RNA sequencing (scRNA-seq) datasets of mouse hindlimb buds, postnatal long bones, and fractured long bones. Our analyses reveal the heterogeneity of osteochondrogenic lineage cells and recapitulate the developmental trajectories during mouse long bone growth. In addition, we identify a novel Cd168+ SSPC population with highly replicating capacity and osteochondrogenic potential in embryonic and postnatal long bones. Moreover, the Cd168+ SSPCs can contribute to newly formed skeletal tissues during fracture healing. Furthermore, the results of multicolor immunofluorescence show that Cd168+ SSPCs reside in the superficial zone of articular cartilage as well as in growth plates of postnatal mouse long bones. In summary, we identify a novel Cd168+ SSPC population with regenerative potential in mouse long bones, which adds to the knowledge of the tissue-specific stem cells in skeletons.

The ecotoxicological effects of chromium (III) oxide nanoparticles to Chlorella sp.: perspective from the physiological and transcriptional responses.

Extensive application of nanomaterials enlarges its concentrations in the aquatic environments and poses a threat to algae. This study comprehensively analyzed the physiological and transcriptional responses of Chlorella sp. after being exposed to chromium (III) oxide nanoparticles (nCr2O3). The nCr2O3 at 0-100 mg/L presented adverse effects on cell growth (96 h EC50 = 16.3 mg/L), decreasing the photosynthetic pigment concentrations and photosynthetic activity. Moreover, more extracellular polymeric substances (EPS), especially polysaccharides in soluble EPS, were produced in algae cell, which mitigated the damage of nCr2O3 to cells. However, with the increase of nCr2O3 doses, the EPS protective responses were exhausted, accompanied by toxicity in the form of organelle damage and metabolic disturbance. The enhanced acute toxicity was closely related to the physical contact of nCr2O3 with cells, oxidative stress, and genotoxicity. Firstly, large amounts of nCr2O3 aggregated around and were attached to cells, causing physical damage. Then, the intracellular reactive oxygen species and malondialdehyde levels were significantly increased that led to lipid peroxidation, especially at 50-100 mg/L nCr2O3. Finally, the transcriptomic analysis further revealed that the transcription of ribosome, glutamine, and thiamine metabolism-related genes were impaired under 20 mg/L nCr2O3, suggesting nCr2O3 inhibited algal cell growth through metabolism, cell defense, and repair, etc.

[Establishment and Evaluation of Intestinal Injury Model of Mouse Acute Graft Versus Host Disease Based on An Organoid Technology].

OBJECTIVE: To establish an intestinal organoid model that mimic acute graft versus host disease (aGVHD) caused intestinal injuries by using aGVHD murine model serum and organoid culture system, and explore the changes of aGVHD intestine in vitro by advantage of organoid technology. METHODS: 20-22 g female C57BL/6 mice and 20-22 g female BALB/c mice were used as donors and recipients for bone marrow transplantation, respectively. Within 4-6 h after receiving a lethal dose (8.0 Gy) of γ ray total body irradiation, a total of 0.25 ml of murine derived bone marrow cells (1×107/mice, n=20) and spleen nucleated cells (5×106/mice, n=20) was infused to establish a mouse model of aGVHD (n=20). The aGVHD mice were anesthetized at the 7th day after transplantation, and the veinal blood was harvested by removing the eyeballs, and the serum was collected by centrifugation. The small intestinal crypts of healthy C57BL/6 mice were harvested and cultivated in 3D culture system that maintaining the growth and proliferation of intestinal stem cells in vitro. In our experiment, 5%, 10%, 20% proportions of aGVHD serum were respectively added into the organoid culture system for 3 days. The formation of small intestinal organoids were observed under an inverted microscope and the morphological characteristics of intestinal organoids in each groups were analyzed. For further evaluation, the aGVHD intestinal organoids were harvested and their pathological changes were observed. Combined with HE staining, intestinal organ morphology evaluation was performed. Combined with Alcian Blue staining, the secretion function of aGVHD intestinal organoids was observed. The distribution and changes of Lgr5+ and Clu+ intestinal stem cells in intestinal organoids were analyzed under the conditions of 5%, 10% and 20% serum concentrations by immunohistochemical stainings. RESULTS: The results of HE staining showed that the integrity of intestinal organoids in the 5% concentration serum group was better than that in the 10% and 20% groups. The 5% concentration serum group showed the highest number of organoids, the highest germination rate and the lowest pathological score among experimental groups, while the 20% group exhibited severe morphological destruction and almost no germination was observed, and the pathological score was the highest among all groups(t=3.668, 4.334,5.309,P<0.05). The results of Alican blue staining showed that the secretion function of intestinal organoids in serum culture of aGVHD in the 20% group was weaker than that of the 5% group and 10% of the organoids, and there was almost no goblet cells, and mucus was stainned in the 20% aGVHD serum group. The immunohistochemical results showed that the number of Lgr5+ cells of intestinal organoids in the 5% group was more than that of the intestinal organoids in the 10% aGVHD serum group and 20% aGVHD serum group. Almost no Clu+ cells were observed in the 5% group. The Lgr5+ cells in the 20% group were seriously injuried and can not be observed. The proportion of Clu+ cells in the 20% group significantly increased. CONCLUSION: The concentration of aGVHD serum in the culture system can affect the number and secretion function of intestinal organoids as well as the number of intestinal stem cells in organoids. The higher the serum concentration, the greater the risk of organoid injury, which reveal the characteristics of the formation and functional change of aGVHD intestinal organoids, and provide a novel tool for the study of intestinal injury in aGVHD.

The nutrient removal and tolerance mechanism of a heterotrophic nitrifying bacterium Pseudomonas putida strain NP5 under metal oxide nanoparticles stress.

The occurrence of metal oxide nanoparticles (NPs) in wastewater treatment plants (WWTPs) has raised great concerns about their adverse impacts on nitrification performance. In this study, a heterotrophic nitrifying bacterium Pseudomonas putida strain NP5 showed strong resistance against TiO2 and NiO NPs. Under 5-50 mg/L NP stress, cell viability was still normal, and the final nutrient removal rates, always higher than 80%, were slightly inhibited. Correspondingly, the PO43--P removal rates were almost the same as those observed in the control test. Although the enzyme assay demonstrated ammonia monooxygenase and hydroxylamine oxidoreductase activities markedly decreased caused by increased reactive oxygen species (ROS) level under 50 mg/L NPs stress. The total antioxidant capability of NP5 could eliminate excess ROS to maintain a balance between oxidants and antioxidants. Besides, in response to the escalating burden of NPs, strain NP5 tended to secrete more extracellular polymeric substances (EPS), which could protect cell from being damaged by binding to ions and coating. Thus, the strong NP resistance of NP5 would help to overcome the vulnerability of the nitrification process in WWTPs.

Organocatalytic Aza-Michael/Mannich Cascade Reaction: Synthesis of Enantioenriched 3,3'-Spirooxindole γ-Lactams.

Highly enantioselective synthesis of 3,3'-spirooxindole γ-lactams with three contiguous stereocenters (two quaternary) was achieved. The aza-Michael/Mannich cascade reaction of α-imine-ß-oxobutanamides and methyleneindolinones catalyzed by a bifunctional diaminocyclohexane-derived thiourea catalyst gave the desired products in moderate to good yields (up to 78%), moderate to good diastereoselectivities (up to 10:1 dr), and good to excellent enantioselectivities (up to >99% ee). A gram-scale synthesis and some transformations of 3,3'-spirooxindole γ-lactams were also carried out.