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1.
Soft Matter ; 20(27): 5343-5350, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38904343

ABSTRACT

The fabrication of stimulus-responsive supramolecular hydrogels as smart materials has attracted much attention in recent years. However, the multi-stimuli responsiveness often requires complicated chemical synthesis and rational molecular design. Herein, a quadruple-stimuli responsive supramolecular hydrogel was designed through the host-guest interaction between a ß-CD dimer and a methoxy-azobenzene (mAzo) and ferrocene (Fc) grafted poly(acrylic acid) derivative, as well as through the electrostatic interaction of negatively charged carboxyl side groups. Owing to the dynamic properties of the host-guest and electrostatic interactions, reversible sol-gel transition can be triggered by various stimuli, including temperature, light irradiations, pH changes and chemical redox reagents. As a result, the release of rhodamine B loaded in the hydrogel can be accelerated by green light irradiation, oxidizing agents and low pH, demonstrating potential applications in biomedical materials.

2.
J Nanobiotechnology ; 22(1): 265, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38760763

ABSTRACT

BACKGROUND: Pulp regeneration is a novel approach for the treatment of immature permanent teeth with pulp necrosis. This technique includes the combination of stem cells, scaffolds, and growth factors. Recently, stem cell-derived extracellular vesicles (EVs) have emerged as a new methodology for pulp regeneration. Emerging evidence has proven that preconditioning is an effective scheme to modify EVs for better therapeutic potency. Meanwhile, proper scaffolding is of great significance to protect EVs from rapid clearance and destruction. This investigation aims to fabricate an injectable hydrogel loaded with EVs from pre-differentiated stem cells from human exfoliated deciduous teeth (SHEDs) and examine their effects on pulp regeneration. RESULTS: We successfully employed the odontogenic induction medium (OM) of SHEDs to generate functional EV (OM-EV). The OM-EV at a concentration of 20 µg/mL was demonstrated to promote the proliferation and migration of dental pulp stem cells (DPSCs). The results revealed that OM-EV has a better potential to promote odontogenic differentiation of DPSCs than common EVs (CM-EV) in vitro through Alizarin red phalloidin, alkaline phosphatase staining, and assessment of the expression of odontogenic-related markers. High-throughput sequencing suggests that the superior effects of OM-EV may be attributed to activation of the AMPK/mTOR pathway. Simultaneously, we prepared a photocrosslinkable gelatin methacryloyl (GelMA) to construct an OM-EV-encapsulated hydrogel. The hydrogel exhibited sustained release of OM-EV and good biocompatibility for DPSCs. The released OM-EV from the hydrogel could be internalized by DPSCs, thereby enhancing their survival and migration. In tooth root slices that were subcutaneously transplanted in nude mice, the OM-EV-encapsulated hydrogel was found to facilitate dentinogenesis. After 8 weeks, there was more formation of mineralized tissue, as well as higher levels of dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1). CONCLUSIONS: The effects of EV can be substantially enhanced by preconditioning of SHEDs. The functional EVs from SHEDs combined with GelMA are capable of effectively promoting dentinogenesis through upregulating the odontogenic differentiation of DPSCs, which provides a promising therapeutic approach for pulp regeneration.


Subject(s)
Cell Differentiation , Dental Pulp , Extracellular Vesicles , Gelatin , Methacrylates , Odontogenesis , Regeneration , Stem Cells , Tooth, Deciduous , Dental Pulp/cytology , Humans , Extracellular Vesicles/chemistry , Gelatin/chemistry , Gelatin/pharmacology , Cell Differentiation/drug effects , Odontogenesis/drug effects , Animals , Stem Cells/drug effects , Stem Cells/cytology , Stem Cells/metabolism , Regeneration/drug effects , Tooth, Deciduous/cytology , Methacrylates/chemistry , Methacrylates/pharmacology , Mice , Cell Proliferation/drug effects , Mice, Nude , Cells, Cultured , Hydrogels/chemistry , Hydrogels/pharmacology , Cell Movement/drug effects
3.
J Nanobiotechnology ; 22(1): 205, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38658965

ABSTRACT

The elevated level of hydrogen sulfide (H2S) in colon cancer hinders complete cure with a single therapy. However, excessive H2S also offers a treatment target. A multifunctional cascade bioreactor based on the H2S-responsive mesoporous Cu2Cl(OH)3-loaded hypoxic prodrug tirapazamine (TPZ), in which the outer layer was coated with hyaluronic acid (HA) to form TPZ@Cu2Cl(OH)3-HA (TCuH) nanoparticles (NPs), demonstrated a synergistic antitumor effect through combining the H2S-driven cuproptosis and mild photothermal therapy. The HA coating endowed the NPs with targeting delivery to enhance drug accumulation in the tumor tissue. The presence of both the high level of H2S and the near-infrared II (NIR II) irradiation achieved the in situ generation of photothermic agent copper sulfide (Cu9S8) from the TCuH, followed with the release of TPZ. The depletion of H2S stimulated consumption of oxygen, resulting in hypoxic state and mitochondrial reprogramming. The hypoxic state activated prodrug TPZ to activated TPZ (TPZ-ed) for chemotherapy in turn. Furthermore, the exacerbated hypoxia inhibited the synthesis of adenosine triphosphate, decreasing expression of heat shock proteins and subsequently improving the photothermal therapy. The enriched Cu2+ induced not only cuproptosis by promoting lipoacylated dihydrolipoamide S-acetyltransferase (DLAT) heteromerization but also performed chemodynamic therapy though catalyzing H2O2 to produce highly toxic hydroxyl radicals ·OH. Therefore, the nanoparticles TCuH offer a versatile platform to exert copper-related synergistic antitumor therapy.


Subject(s)
Copper , Hyaluronic Acid , Hydrogen Sulfide , Mitochondria , Nanoparticles , Photothermal Therapy , Prodrugs , Tirapazamine , Photothermal Therapy/methods , Hydrogen Sulfide/metabolism , Hydrogen Sulfide/pharmacology , Animals , Copper/chemistry , Copper/pharmacology , Mice , Humans , Mitochondria/metabolism , Mitochondria/drug effects , Prodrugs/pharmacology , Prodrugs/chemistry , Tirapazamine/pharmacology , Tirapazamine/chemistry , Nanoparticles/chemistry , Hyaluronic Acid/chemistry , Cell Line, Tumor , Colonic Neoplasms/therapy , Colonic Neoplasms/metabolism , Colonic Neoplasms/drug therapy , Mice, Inbred BALB C , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Mice, Nude
4.
Ecotoxicol Environ Saf ; 269: 115745, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38029583

ABSTRACT

Magnetic graphene oxide nanocomposites (MGO NPs) have been widely studied in biomedical applications. However, their cytotoxicity and underlying mechanisms remain unclear. In this study, the biosafety of MGO NPs was investigated, and the mechanism involved in ferroptosis was further explored. MGO can produce cytotoxicity in ADSCs, which is dependent on their concentration. Ferroptosis was involved in MGO NP-induced ADSC survival inhibition by increasing total ROS and lipid ROS accumulation as well as regulating the expression levels of ferroptosis-related genes and proteins. GPX4 played a critical role in the MGO NP-induced ADSC ferroptosis process, and overexpressing GPX4 suppressed ferroptosis to increase cell survival. This study provides a theoretical basis for the biosafety management of MGO NPs used in the field of biomedical treatment.


Subject(s)
Ferroptosis , Graphite , Nanocomposites , Phospholipid Hydroperoxide Glutathione Peroxidase , Ferroptosis/genetics , Graphite/toxicity , Magnesium Oxide , Magnetic Phenomena , Nanocomposites/toxicity , Reactive Oxygen Species , Animals , Rats , Mesenchymal Stem Cells/metabolism , Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism
5.
Clin Sci (Lond) ; 137(17): 1373-1389, 2023 09 13.
Article in English | MEDLINE | ID: mdl-37615536

ABSTRACT

N6-methyladenosine (m6A) plays crucial roles in tumorigenesis and autophagy. However, the underlying mechanisms mediated by m6A and autophagy in the malignant progression of oral squamous cell carcinoma (OSCC) remain unclear. In the present study, we revealed that down-regulated expression of METTL14 was correlated with advanced clinicopathological characteristics and poor prognosis in OSCC. METTL14 knockdown significantly inhibited autophagy and facilitated malignant progression in vitro, and promoted tumor growth and metastasis in vivo. A cell model of rapamycin-induced autophagy was established to identify RB1CC1 as a potential target gene involved in m6A-regulated autophagy in OSCC, through RNA sequencing and methylated RNA immunoprecipitation sequencing (meRIP-seq) analysis. Mechanistically, we confirmed that METTL14 posttranscriptionally enhanced RB1CC1 expression in an m6A-IGF2BP2-dependent manner, thereby affecting autophagy and progression in OSCC, through methylated RNA immunoprecipitation qRT-PCR (meRIP-qPCR), RNA stability assays, mutagenesis assays and dual-luciferase reporter. Collectively, our findings demonstrated that METTL14 serves as an OSCC suppressor by regulating the autophagy-related gene RB1CC1 through m6A modification, which may provide a new insight for the diagnosis and therapy of OSCC.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Humans , Carcinoma, Squamous Cell/genetics , Squamous Cell Carcinoma of Head and Neck/genetics , Mouth Neoplasms/genetics , Autophagy/genetics , Autophagy-Related Proteins/genetics , RNA-Binding Proteins/genetics , Methyltransferases/genetics
6.
BMC Musculoskelet Disord ; 24(1): 243, 2023 Mar 30.
Article in English | MEDLINE | ID: mdl-36997961

ABSTRACT

PURPOSE: Proximal humerus fractures (PHFs) are common. With the development of locking plates, open reduction and internal fixation (ORIF) of the proximal humerus can provide excellent clinical outcomes. The quality of fracture reduction is crucial in the locking plate fixation of proximal humeral fractures. The purpose of this study was to determine the impact of 3-dimensional (3D) printing technology and computer virtual technology assisted preoperative simulation on the reduction quality and clinical outcomes of 3-part and 4-part proximal humeral fractures. METHOD: A retrospective comparative analysis of 3-part and 4-part PHFs undergoing open reduction internal fixation was performed. Patients were divided into 2 groups according to whether computer virtual technology and 3D printed technology were used for preoperative simulation: the simulation group and the conventional group. Operative time, intraoperative bleeding, hospital stay, quality of fracture reduction, Constant scores, American Society for Shoulder and Elbow Surgery (ASES) scores, shoulder range of motion, complications, and revision surgeries were assessed. RESULTS: This study included 67 patients (58.3%) in the conventional group and 48 patients (41.7%) in the simulation group. The patient demographics and fracture characteristics were comparable in these groups. Compared with the conventional group, the simulation group had shorter operation time and less intraoperative bleeding (P < 0.001, both). Immediate postoperative assessment of fracture reduction showed a higher incidence of greater tuberosity cranialization of < 5 mm, neck-shaft angle of 120° to 150°, and head shaft displacement of < 5 mm in the simulation group. The incidence of good reduction was 2.6 times higher in the simulation group than in the conventional group (95% CI, 1.2-5.8). At the final follow-up, the chance of forward flexion > 120° (OR 5.8, 95% CI 1.8-18.0) and mean constant score of > 65 (OR 3.4, 95% CI 1.5-7.4) was higher in the simulation group than the conventional group, as well as a lower incidence of complications in the simulation group was obtained (OR 0.2, 95% CI 0.1-0.6). CONCLUSIONS: This study identified that preoperative simulation assisted by computer virtual technology and 3D printed technology can improve reduction quality and clinical outcomes in treatment of 3-part and 4-part PHFs.


Subject(s)
Humeral Fractures , Shoulder Fractures , Humans , Retrospective Studies , Treatment Outcome , Fracture Fixation, Internal/adverse effects , Fracture Fixation, Internal/methods , Humerus , Bone Plates , Shoulder Fractures/diagnostic imaging , Shoulder Fractures/surgery , Humeral Fractures/surgery
7.
Chaos ; 33(1): 013141, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36725623

ABSTRACT

Fractional-order systems generalize classical differential systems and have empirically shown to achieve fine-grain modeling of the temporal dynamics and frequency responses of certain real-world phenomena. Although the study of integer-order memory element (mem-element) emulators has persisted for several years, the study of fractional-order mem-elements has received little attention. To promote the study of the characteristics and applications of mem-element systems in fractional calculus and memory systems, a novel universal fractional-order mem-elements interface for constructing three types of fractional-order mem-element emulators is proposed in this paper. With the same circuit topology, the floating fractional-order memristor, the fractional-order memcapacitor, and fractional-order meminductor emulators can be implemented by simply combining the impedances of different passive elements. PSPICE circuit simulation and printed circuit board hardware experiments validate the dynamical behaviors and effectiveness of our proposed emulators. In addition, the dynamic relationship between fractional-order parameters and values of fractional-order impedance is explored in MATLAB simulation. The proposed fractional-order mem-element emulators built based on the universal interface are constructed with a small number of active and passive elements, which not only reduces the cost but also promotes the development of fractional-order mem-element emulators and application research for the future.

8.
Drug Dev Res ; 84(2): 211-225, 2023 04.
Article in English | MEDLINE | ID: mdl-36567664

ABSTRACT

Acetaminophen (APAP) overdose-induced acute liver injury (ALI) causes hepatocyte cell death, oxidative stress, and inflammation. Oridonin (Ori), a covalent NLRP3-inflammasome inhibitor, ameliorates APAP-induced ALI through an unclear molecular mechanism. This study found that Ori decreased hepatic cytochrome P450 2E1 level and increased glutathione content to prevent APAP metabolism, and then reduced the necrotic area, improved liver function, and inhibited APAP-induced proinflammatory cytokines and oxidative stress. Ori also decreased activating transcription factor 4 (ATF4) protein levels and increased peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) to reduce APAP-induced endoplasmic reticulum stress activation and mitochondrial dysfunction. Furthermore, western blot and luciferase assay found that ATF4 inhibited transcription in the PGC-1α promoter -507 to -495 region to reduce PGC-1α levels, while ATF4 knockdown neutralized the hepatoprotective effect of Ori. Molecular docking showed that Ori bound to ATF4's amino acid residue glutamate 302 through 6, 7, and 18 hydroxyl bands. Our findings demonstrated that Ori prevented metabolic activation of APAP and further inhibited the ATF4/PGC-1α pathway to alleviate APAP overdose-induced hepatic toxicity, which illuminated its potential therapeutic effects on ALI.


Subject(s)
Acetaminophen , Chemical and Drug Induced Liver Injury , Humans , Acetaminophen/adverse effects , Activating Transcription Factor 4/metabolism , Activating Transcription Factor 4/pharmacology , Chemical and Drug Induced Liver Injury/drug therapy , Chemical and Drug Induced Liver Injury/metabolism , Liver , Molecular Docking Simulation , Oxidative Stress , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism
9.
BMC Oral Health ; 23(1): 395, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37322508

ABSTRACT

BACKGROUND: Curved root canals lead to difficulties in cleaning, shaping and filling the root canal system. Apical extrusion of debris and root canal transportation are important factors causing postoperative complications. In clinical practice, commonly selected instruments include multifile NiTi systems, such as M3-Pro PLUS (M3-PRO), Orodeka Plex 2.0 (ODP), Rotate (ROT), and Protaper Gold (PTG), as well as single-file NiTi systems, such as M3-L Platinum 2019 (M3L), Waveone Gold (WOG), and Reciproc Blue (RCB). This study aimed to comprehensively evaluate the differences in the apical extrusion of debris and centering ability of the above NiTi files. METHODS: Seventy 3D-printed resin teeth were used (n = 10). The apically extruded debris was collected in a preweighed centrifuge tube. The resin teeth with or without root canal preparation were cut into separate cross sections at 1 mm, 3 mm, 5 mm, and 7 mm away from the root apex, and then the root canal transportation and centering ratio of each cross section were calculated. RESULTS: Apical extrusion of debris was highest in RCB but lowest in OD-P (P < 0.05). Root call deviation was lowest in ROT at the 3 mm level, in PTG at the 5 mm level, and in PTG and ROT at the 7 mm level (P < 0.05). The centering ratio of NiTi files was highest in the RCB group at the 3 mm level, in the PTG group at the 5 mm level, in the ROT group at the 7 mm level (P < 0.05). CONCLUSIONS: For NiTi files with the same system, the cross-sectional design is the greatest factor affecting the extrusion of debris, and motion mode is the second. In addition, the multifile system could reduce the degree of root canal transportation.


Subject(s)
Nickel , Root Canal Preparation , Humans , Titanium , Cross-Sectional Studies , Gold , Dental Pulp Cavity/surgery , Equipment Design
10.
Exp Cell Res ; 408(2): 112864, 2021 11 15.
Article in English | MEDLINE | ID: mdl-34626586

ABSTRACT

Dental implant surgery is currently a routine therapy for the repair of missing dentition or dentition defects. Both clinical and basic research have elucidated that oxidative stress caused by the accumulation of reactive oxygen species (ROS) for various reasons impairs the process of osteointegration after dental implantation. Therefore, the osteogenic micro-environment must be ameliorated to decrease the damage caused by oxidative stress. Selenomethionine (SEMET) has been reported to play an important role in alleviating oxidative stress and accelerating cell viability and growth. However, it remains unclear whether it exerts protective effects on bone-marrow-derived mesenchymal stem cells (BMSCs) under oxidative stress. In this study, we explored the influence of selenomethionine on the viability and osteogenic differentiation of BMSCs under oxidative stress and the underlying mechanisms. Results showed that 1 µM selenomethionine was the optimum concentration for BMSCs under H2O2 stimulation. H2O2-induced oxidative stress suppressed the viability and osteogenic differentiation of BMSCs, manifested by the increases in ROS production and cell apoptosis rates, and by the decrease of osteogenic differentiation-related markers. Notably, the aforementioned oxidative damage and osteogenic dysfunction induced by H2O2 were rescued by selenomethionine. Furthermore, we found that the PTEN expression level was suppressed and its downstream PI3K/AKT pathway was activated by selenomethionine. However, when PTEN was stimulated, the PI3K/AKT pathway was down-regulated, and the protective effects of selenomethionine on BMSC osteogenic differentiation diminished, while the inhibition of PTEN up-regulated the protective effects of selenomethionine. Together, these results revealed that selenomethionine could attenuate H2O2-induced BMSC dysfunction through an antioxidant effect, modulated via the PTEN/PI3K/AKT pathway, suggesting that selenomethionine is a promising antioxidant candidate for reducing oxidative stress during the process of dental implant osteointegration.


Subject(s)
Antioxidants/pharmacology , Cell Differentiation/drug effects , Osteogenesis/drug effects , Oxidative Stress/drug effects , Selenomethionine/pharmacology , Apoptosis/drug effects , Cell Survival/drug effects , Cells, Cultured , Dental Implants/adverse effects , Humans , Hydrogen Peroxide/toxicity , Mesenchymal Stem Cells/drug effects , PTEN Phosphohydrolase/genetics , Phosphatidylinositol 3-Kinases/genetics , Proto-Oncogene Proteins c-akt , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects
11.
BMC Cancer ; 21(1): 835, 2021 Jul 20.
Article in English | MEDLINE | ID: mdl-34284753

ABSTRACT

BACKGROUND: The prognosis of oral squamous cell carcinoma (OSCC) patients is difficult to predict or describe due to its high-level heterogeneity and complex aetiologic factors. Ferroptosis is a novel form of iron-dependent cell death that is closely related to tumour growth and progression. This study aims to clarify the predictive value of ferroptosis-related genes (FRGs) on the overall survival(OS) of OSCC patients. METHODS: The mRNA expression profile of FRGs and clinical information of patients with OSCC were collected from the TCGA database. Candidate differentially expressed ferroptosis-related genes (DE-FRGs) were identified by analysing differences between OSCC and adjacent normal tissues. A gene signature of prognosis-related DE-FRGs was established by univariate Cox analysis and LASSO analysis in the training set. Patients were then divided into high- and low-risk groups according to the cut-off value of risk scores, A nomogram was constructed to quantify the contributions of gene signature and clinical parameters to OS. Then several bioinformatics analyses were used to verify the reliability and accuracy of the model in the validation set. Finally, single-sample gene set enrichment analysis (ssGSEA) was also performed to reveal the underlying differences in immune status between different risk groups. RESULTS: A prognostic model was constructed based on 10 ferroptosis-related genes. Patients in high-risk group had a significantly worse OS (p < 0.001). The gene signature was verified as an independent predictor for the OS of OSCC patients (HR > 1, p < 0.001). The receiver operating characteristic curve displayed the favour predictive performance of the risk model. The prediction nomogram successfully quantified each indicator's contribution to survival and the concordance index and calibration plots showed its superior predictive capacity. Finally, ssGSEA preliminarily indicated that the poor prognosis in the high-risk group might result from the dysregulation of immune status. CONCLUSION: This study established a 10-ferroptosis-releated gene signature and nomogram that can be used to predict the prognosis of OSCC patients, which provides new insight for future anticancer therapies based on potential FRG targets.


Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/genetics , Ferroptosis/genetics , Gene Expression Profiling/methods , Gene Expression Regulation, Neoplastic/genetics , Mouth Neoplasms/genetics , Carcinoma, Squamous Cell/pathology , Humans , Middle Aged , Mouth Neoplasms/pathology , Prognosis
12.
Nanotechnology ; 33(6)2021 Nov 18.
Article in English | MEDLINE | ID: mdl-34724655

ABSTRACT

Lithium-rich layered manganese-based cathodes (LRLMOs) with first-class energy density (∼1000 W h kg-1) have attracted wide attention. Nevertheless, the weak cycle stability and bad rate capability obstruct their large-scale commercial application. Here, single crystal Li1.2-xNaxNi0.2Mn0.6O2(x = 0, 0.05, 0.1, 0.15) nanoparticles are designed and successfully synthesized due to the single crystal structure with smaller internal stress and larger ionic radius of Na. The synergistic advantages of single crystal structure and Na doping are authenticated as cathodes for Li ion batteries (LIBs), which can consolidate the crystallographic structure and be benefit for migration of lithium ion. Among all the Na doping single crystals, Li1.1Na0.1Ni0.2Mn0.6O2cathode possesses supreme cycling life and discharge capacity at large current density. To be more specific, it exhibits a discharge capacity of 264.2 mAh g-1after 50 charge and discharge cycles, higher than that of undoped material (214.9 mAh g-1). The discharge capacity of Li1.1Na0.1Ni0.2Mn0.6O2cathode at 10 C (1 C = 200 mA g-1) is enhanced to 160.4 mAh g-1(106.7 mAh g-1forx = 0 sample). The creative strategy of Na doping single crystal LRLMOs might furnish an idea to create cathode materials with high energy and power density for next generation LIBs.

13.
Nanomedicine ; 37: 102435, 2021 10.
Article in English | MEDLINE | ID: mdl-34186257

ABSTRACT

The biological behaviors of magnetic graphene oxide (MGO) in a static magnetic field (SMF) are unknown. The current study is to investigate the cellular behaviors, osteogenesis and the mechanism in BMSCs treated with MGO combined with an SMF. Results showed that the synthetic MGO particles were bio-compatible and could significantly improve the osteogenesis of BMSCs under SMFs, as verified by elevated alkaline phosphatase activity, mineralized nodule formation, and expressions of mRNA and protein levels. Under SMF at the same intensity, the addition of graphene oxide to Fe3O4 could increase the osteogenic ability of BMSCs. The Wnt/ß-catenin pathway was indicated to be related to the MGO-driven osteogenic behavior of the BMSCs under SMF. Taken together, our findings suggested that MGO under an SMF could promote osteogenesis in BMSCs through the Wnt/ß-catenin pathway and hence should attract more attention for practical applications in bone tissue regeneration.


Subject(s)
Graphite/pharmacology , Magnetic Fields , Magnetite Nanoparticles/chemistry , Osteogenesis/genetics , Animals , Cell Differentiation/drug effects , Cell Differentiation/radiation effects , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Developmental/radiation effects , Graphite/chemistry , Humans , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/radiation effects , Osteogenesis/drug effects , Osteogenesis/radiation effects , Rats , Wnt Signaling Pathway/drug effects , Wnt Signaling Pathway/radiation effects
14.
Proc Natl Acad Sci U S A ; 115(16): 4045-4050, 2018 04 17.
Article in English | MEDLINE | ID: mdl-29666318

ABSTRACT

China's croplands have experienced drastic changes in management practices, such as fertilization, tillage, and residue treatments, since the 1980s. There is an ongoing debate about the impact of these changes on soil organic carbon (SOC) and its implications. Here we report results from an extensive study that provided direct evidence of cropland SOC sequestration in China. Based on the soil sampling locations recorded by the Second National Soil Survey of China in 1980, we collected 4,060 soil samples in 2011 from 58 counties that represent the typical cropping systems across China. Our results showed that across the country, the average SOC stock in the topsoil (0-20 cm) increased from 28.6 Mg C ha-1 in 1980 to 32.9 Mg C ha-1 in 2011, representing a net increase of 140 kg C ha-1 year-1 However, the SOC change differed among the major agricultural regions: SOC increased in all major agronomic regions except in Northeast China. The SOC sequestration was largely attributed to increased organic inputs driven by economics and policy: while higher root biomass resulting from enhanced crop productivity by chemical fertilizers predominated before 2000, higher residue inputs following the large-scale implementation of crop straw/stover return policy took over thereafter. The SOC change was negatively related to N inputs in East China, suggesting that the excessive N inputs, plus the shallowness of plow layers, may constrain the future C sequestration in Chinese croplands. Our results indicate that cropland SOC sequestration can be achieved through effectively manipulating economic and policy incentives to farmers.


Subject(s)
Agriculture/methods , Carbon Sequestration , Carbon/analysis , Conservation of Natural Resources/legislation & jurisprudence , Organic Chemicals/analysis , Policy , Soil/chemistry , Agriculture/economics , Agrochemicals/chemistry , China , Composting , Conservation of Natural Resources/economics , Conservation of Natural Resources/statistics & numerical data , Crops, Agricultural/chemistry , Farms , Human Activities , Humans , Plant Dispersal , Plant Roots/chemistry , Plant Stems/chemistry , Plants/chemistry , Social Change , Soil Microbiology
15.
J Environ Manage ; 290: 112666, 2021 Jul 15.
Article in English | MEDLINE | ID: mdl-33910073

ABSTRACT

Based on data of 285 Chinese cities from 2003 to 2017, this paper mainly studies the impact of the spatial agglomeration of Foreign direct investment (FDI) on the green total factor productivity(TFP) of Chinese cities by SDM model. It is measured that China's urban green TFP generally has been developing well from 2003 to 2017, and progress in green technology plays an important role in improving urban green TFP. Both global Moran index and local Moran scatter plots show that FDI and green TFP are characterized by strong spatial agglomeration. This suggests green TFP is closely related to the spatial agglomeration of FDI in a region. The paper finds that FDI plays a positive role in promoting green TFP in high-high and high-low cluster cities, and the technology spillover effect of highly agglomerated FDI is more significant than that of decentralized FDI, thus promoting the upgrading and agglomeration of green TFP in itself and surrounding cities. The positive benefits of low-high and low-low cluster cities are not significant. Therefore, it is necessary to go beyond its policy of administrative regions and give full play to radiation effect of High-high FDI agglomeration cities and promote the green TFP of their surrounding cities.


Subject(s)
Economic Development , Investments , China , Cities , Internationality
16.
Biochem Biophys Res Commun ; 532(3): 433-439, 2020 11 12.
Article in English | MEDLINE | ID: mdl-32891432

ABSTRACT

Mesenchymal stem cells (MSCs) are an important cell source for tissue homeostasis and repair due to their stemness characteristic. Lots of intrinsic signaling pathways have been reported to regulate MSC stemness, but the extrinsic signals such as sodium lactate, particularly in physiological conditions, are poorly understood. Herein, we evaluated the effect of sodium lactate on human MSC stemness regulation by examining colony-forming ability, energy metabolism, multi-lineage differentiation ability, and pluripotent gene and protein expression. The underlying mechanism was further investigated with gene knockdown as well as small molecule interference and rescue experiments. We found that: (1) low concentration (1 mM) of sodium lactate promoted the stemness of human MSCs; (2) the upregulation of glycolysis was responsible for the MSC stemness promotion; (3) lysine demethylase 6B (KDM6B) was the key regulator which mediated sodium lactate-induced glycolysis and human MSC stemness enhancement. This study indicated that sodium lactate played an important role in human MSC stemness maintenance in physiological conditions, which could be related to KDM6B mediated metabolic regulation. It would provide new insight into stem cell biology, and contribute to cell transplantation and tissue regeneration strategies.


Subject(s)
Glycolysis/drug effects , Jumonji Domain-Containing Histone Demethylases/metabolism , Mesenchymal Stem Cells/drug effects , Sodium Lactate/pharmacology , Cell Differentiation/drug effects , Cell Differentiation/genetics , Cell Self Renewal/drug effects , Cell Self Renewal/genetics , Cells, Cultured , Colony-Forming Units Assay , Energy Metabolism/drug effects , Gene Expression/drug effects , Gene Knockdown Techniques , Glycolysis/genetics , Humans , Jumonji Domain-Containing Histone Demethylases/antagonists & inhibitors , Jumonji Domain-Containing Histone Demethylases/genetics , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Up-Regulation/drug effects
17.
Cancer Cell Int ; 20(1): 523, 2020 Oct 29.
Article in English | MEDLINE | ID: mdl-33292198

ABSTRACT

Pyruvate kinase is a terminal enzyme in the glycolytic pathway, where it catalyzes the conversion of phosphoenolpyruvate to pyruvate and production of ATP via substrate level phosphorylation. PKM2 is one of four isoforms of pyruvate kinase and is widely expressed in many types of tumors and associated with tumorigenesis. In addition to pyruvate kinase activity involving the metabolic pathway, increasing evidence demonstrates that PKM2 exerts a non-metabolic function in cancers. PKM2 has been shown to be translocated into nucleus, where it serves as a protein kinase to phosphorylate various protein targets and contribute to multiple physiopathological processes. We discuss the nuclear localization of PKM2, its protein kinase function and association with cancers, and regulation of PKM2 activity.

18.
FASEB J ; 33(9): 10425-10442, 2019 09.
Article in English | MEDLINE | ID: mdl-31219699

ABSTRACT

Triggering receptor expressed in myeloid cells (TREM)2 is a genetic high-risk factor for sporadic Alzheimer's disease (AD) and is considered a potential target for AD diagnosis and therapy, although its role in the different stages of AD remains controversial. We generated an embryonic deletion of Trem2 (whole body deletion) and induced hippocampal- and cortical-specific knockdown of microglial Trem2 at different stages of the AD process in amyloid precursor protein/Psen1 mice by adeno-associated virus (AAV) infection. AAV infection induced microglial Trem2 overexpression in the hippocampus of wild-type (WT) and thymus cell antigen 1-enhanced green fluorescent protein mice. Mice were subjected to ethological and pathologic tests. Whole body genetic deletion of Trem2 exerted different electrophysiological outcomes between different AD pathologic stages, which results from a complex integration of synaptic loss and amyloid aggregation. Interestingly, knockdown of Trem2 at the early-middle stage of AD (2-6 mo) prevents synaptic loss through directly inhibiting microglial phagocytosis, whereas knockdown of Trem2 at the middle-late stage of AD (6-10 mo) accelerates synaptic dysfunction because of more severe amyloid deposition caused by the depression of microglial phagocytosis. Additionally, hippocampal overexpression of Trem2 in WT mice results in significant synaptic impairment. Here, with transgenic technology and electrophysiological assay, we revealed that TREM2 up-regulation promotes microglial phagocytosis equally against synapse and amyloid plaques and eventually results in different outcomes. During the early-middle pathologic stage, TREM2 enhancing microglial phagocytosis mainly causes synaptic loss. However, TREM2 up-regulating microglial phagocytosis gradually supports a positive role when amyloid deposition occupies the leading position at the middle-late pathologic stage. In this study, we highlighted that TREM2 triggers synaptic loss during AD pathology development.-Sheng, L., Chen, M., Cai, K., Song, Y., Yu, D., Zhang, H., Xu, G. Microglial Trem2 induces synaptic impairment at early stage and prevents amyloidosis at late stage in APP/PS1 mice.


Subject(s)
Alzheimer Disease/complications , Amyloid beta-Protein Precursor/physiology , Amyloidosis/prevention & control , Membrane Glycoproteins/physiology , Plaque, Amyloid/pathology , Presenilin-1/physiology , Receptors, Immunologic/physiology , Synapses/pathology , Amyloidosis/etiology , Amyloidosis/pathology , Animals , Brain/metabolism , Brain/pathology , Disease Models, Animal , Male , Mice , Mice, Knockout , Mice, Transgenic , Microglia/metabolism , Phagocytosis , Plaque, Amyloid/metabolism , Synapses/metabolism , Synaptic Transmission
19.
Exp Cell Res ; 374(2): 365-373, 2019 01 15.
Article in English | MEDLINE | ID: mdl-30576678

ABSTRACT

Growth-arrest-specific transcript 5 (GAS5) functions as a tumor suppressor in a variety of cancers. GAS5 has been reported to be down-regulated in oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the mechanisms of how GAS5 acts as a tumor suppressor in OSCC. qRT-PCR, cell viability, wound-healing, and transwell assays showed that knockdown of GAS5 increased miR-21 expression and promoted proliferation, migration, invasion, and epithelial-mesenchymal transition of OSCC cells. In contrast, overexpression of GAS5 showed the opposite effects. Furthermore, miR-21 overexpression reversed the effect of GAS5. Western blot showed that knockdown of GAS5 suppressed PTEN, while phosphorylation of Akt was promoted. PCNA, cyclinD1, and Ki-67 were up-regulated, indicating enhanced proliferation. E-cadherin was down-regulated, while N-cadherin, vimentin, and snail1 were increased, indicating augmented epithelial-mesenchymal transition. Overexpression of GAS5 regulated these proteins inversely. Overexpression of miR-21 reversed the effect of GAS5 on these proteins. Taken together, GAS5 suppresses proliferation, migration, invasion, and epithelial-mesenchymal transition in OSCC through the miR-21/PTEN axis and might be a novel therapeutic target for OSCC.


Subject(s)
Carcinoma, Squamous Cell/genetics , Cell Movement/genetics , Cell Proliferation/genetics , Epithelial-Mesenchymal Transition/genetics , MicroRNAs/genetics , Mouth Neoplasms/genetics , PTEN Phosphohydrolase/genetics , RNA, Long Noncoding/genetics , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Down-Regulation/genetics , Gene Expression Regulation, Neoplastic/genetics , Genes, Tumor Suppressor/physiology , Humans , Mouth Neoplasms/pathology , Proto-Oncogene Proteins c-akt/genetics , Signal Transduction/genetics , Up-Regulation/genetics
20.
Chaos ; 30(3): 033108, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32237757

ABSTRACT

Crosstalk phenomena taking place between synapses can influence signal transmission and, in some cases, brain functions. It is thus important to discover the dynamic behaviors of the neural network infected by synaptic crosstalk. To achieve this, in this paper, a new circuit is structured to emulate the Coupled Hyperbolic Memristors, which is then utilized to simulate the synaptic crosstalk of a Hopfield Neural Network (HNN). Thereafter, the HNN's multi-stability, asymmetry attractors, and anti-monotonicity are observed with various crosstalk strengths. The dynamic behaviors of the HNN are presented using bifurcation diagrams, dynamic maps, and Lyapunov exponent spectrums, considering different levels of crosstalk strengths. Simulation results also reveal that different crosstalk strengths can lead to wide-ranging nonlinear behaviors in the HNN systems.


Subject(s)
Models, Neurological , Neural Networks, Computer , Synapses/physiology , Humans , Nonlinear Dynamics
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