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The Convolutional Neural Network (CNN) is one of the widely used deep learning models that offers the chance to boost farming productivity through autonomous inference of field conditions. In this paper, CNN is connected to a Support Vector Machine (SVM) to form a new model CNN-SVM; the CNN models chosen are ResNet-50 and VGG16 and the CNN-SVM models formed are ResNet-50-SVM and VGG16-SVM. The method consists of two parts: ResNet-50 and VGG16 for feature extraction and SVM for classification. This paper uses the public multi-class weeds dataset DeepWeeds for training and testing. The proposed ResNet-50-SVM and VGG16-SVM approaches achieved 97.6% and 95.9% recognition accuracies on the DeepWeeds dataset, respectively. The state-of-the-art networks (VGG16, ResNet-50, GoogLeNet, Densenet-121, and PSO-CNN) with the same dataset are accurate at 93.2%, 96.1%, 93.6%, 94.3%, and 96.9%, respectively. In comparison, the accuracy of the proposed methods has been improved by 1.5% and 2.7%, respectively. The proposed ResNet-50-SVM and the VGG16-SVM weed classification approaches are effective and can achieve high recognition accuracy.
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The combined pollution of heavy metals and organic compounds usually occurs simultaneously and induces high toxicity. The technology of simultaneous removal of combined pollution is lacking and the removal mechanism is not clear. Sulfadiazine (SD), a widely used antibiotic, was used as a model contaminant. Urea modified sludge-based biochar (USBC) was prepared and used to catalyze H2O2 to remove the combined pollution of Cu2+ and sulfadiazine (SD) without causing secondary pollution. After 2 h, the removal rates of SD and Cu2+ were 100 and 64.8%, respectively. Cu2+ adsorbed on the surface of USBC accelerated the activation of H2O2 by the USBC catalyzed by CO bond to produce hydroxyl radical (â¢OH) and single oxygen (1O2) to degrade SD. Twenty-three intermediate products were detected, most of which were completely decomposed into CO2 and H2O. The toxicity was significantly reduced in the combined polluted system. This study highlights the potential of the low-cost technology based on sludge reuse and its inherent significance in reducing the toxic risk of combined pollution in the environment.
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Cobre , Peróxido de Hidrogênio , Cobre/química , Peróxido de Hidrogênio/química , Sulfadiazina , Esgotos , Ureia , Carvão Vegetal/química , Oxigênio , Catálise , Estresse OxidativoRESUMO
Aerobic and anaerobic continuous stirred-tank reactor (CSTR), up-flow anaerobic sludge blanket (UASB) were set up and inoculated with newly isolated Candida tropicalis. Reactors were operated at high concentrations of chemical oxygen demand (COD) (8000 mg/L), the modified UASB expressed better COD removal rate simultaneously removal of nitrogen and phosphate than other two reactors. Notably, under both aerobic or anaerobic conditions, large amounts of organic acids and alcohol were generated. Transcriptomic analysis showed that carbon metabolism under anaerobic conditions shared the same pathway with aerobic conditions by regulating and inhibiting some functional genes. Experiments utilizing different carbon sources proved that our strain has excellent performances in utilizing organic materials, which were verified by transcriptomic analysis. Finally, the strain was applied to treat four types of sugar-containing wastewaters. Among them, our strain exerts the best removal capability of COD (90%), nitrogen (89%), and phosphate (82%) for brewery wastewater.
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Nitrogênio , Purificação da Água , Anaerobiose , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Candida tropicalis/genética , Carbono , Fosfatos , Fósforo , Esgotos , Eliminação de Resíduos Líquidos , Águas ResiduáriasRESUMO
Osteoarthritis is the most common degenerative joint disease and causes major pain and disability in adults. It has been reported that mitochondrial dysfunction in chondrocytes is associated with osteoarthritis. Sirtuins are a family of nicotinamide adenine dinucleotide-dependent histone deacetylases that have the ability to deacetylate protein targets and play an important role in the regulation of cell physiological and pathological processes. Among sirtuin family members, sirtuin 3, which is mainly located in mitochondria, can exert its deacetylation activity to regulate mitochondrial function, regeneration, and dynamics; these processes are presently recognized to maintain redox homeostasis to prevent oxidative stress in cell metabolism. In this review, we provide present opinions on the effect of mitochondrial dysfunction in osteoarthritis. Furthermore, the potential protective mechanism of SIRT3-mediated mitochondrial homeostasis in the progression of osteoarthritis is discussed.
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Mitocôndrias/metabolismo , Osteoartrite/patologia , Sirtuína 3/metabolismo , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Matriz Extracelular/metabolismo , Humanos , Mitocôndrias/genética , Mitofagia , Osteoartrite/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Dihydroartemisinin (DHA) is a semi-synthetic derivative and the main active metabolite of artemisinin. The purpose of this study was to investigate the effect of DHA on the ulcerative colitis (UC) in both in vivo and in vitro models. Weight, survival rate, colon length, and Disease Activity Index score were used to evaluate the severity of colitis. Reverse transcription quantitative polymerase chain reaction and enzyme-linked immunosorbent assay were used to detect the expressions of cytokines interleukin (IL)-1, IL-1ß, IL-4, IL-6, IL-10, IL-12, and tumor necrosis factor-α (TNF-α). The expressions of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), and the phosphorylation of JAK2 (p-JAK2) and STAT3 (p-STAT3), were measured by western blot analysis. Western blot analysis and immunohistochemistry were used to detect the expressions of tight junction proteins. We found that the weights and colon lengths of mice in dextran sodium sulfate (DSS)+DHA group were significantly lower and longer than those in the DSS group, respectively. Compared with those in the DSS group, the expressions of IL-1ß, IL-6, IL-17, and TNF-α in the DSS+DHA and DSS+5-aminosalicylic acid (5-ASA) groups were decreased, while the expressions of IL-4 and IL-10 were significantly upregulated. DHA largely increased the expressions of zonula occludens-1 and occludin. Western blot analysis and/or immunohistochemical staining analysis showed that the expressions of JAK2, STAT3, p-JAK2, and p-STAT3 in DSS+DHA and DSS+5-ASA groups were significantly lower than those in DSS group. DHA has a specific therapeutic effect on UC. The anti-inflammatory mechanism of DHA is related to the blockage of the JAK2/STAT3 signaling pathway. These findings provide evidence that DHA may be a useful drug and is expected to become a promising new treatment for human UC.
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Anti-Inflamatórios/farmacologia , Artemisininas/farmacologia , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Janus Quinase 2/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Apoptose/efeitos dos fármacos , Artemisininas/uso terapêutico , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Humanos , Interleucinas/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Ocludina/metabolismo , Células THP-1 , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
NR4A3 is a member of nuclear receptor subfamily 4, which is an important regulator of cellular function and inflammation. In this study, high expression of NR4A3 in human osteoarthritis (OA) cartilage was firstly observed. To explore the relationship between NR4A3 and OA, we used a lentivirus overexpression system to simulate its high expression and study its role in OA. Additionally, siRNA-mediated knockdown of NR4A3 was used to confirm the findings of overexpression experiments. The results showed the stimulatory effect of IL-1ß on cartilage matrix-degrading enzyme expression such as MMP-3, 9, INOS and COX-2 was enhanced in NR4A3-overexpressed chondrocytes and decreased in NR4A3-knockdown chondrocytes at both mRNA and protein levels, while IL-1ß-induced chondrocyte-specific gene (collagen 2 and SOX-9) degradation was only regulated by NR4A3 at protein level. Furthermore, overexpression of NR4A3 would also enhance EBSS-induced chondrocytes apoptosis, while knockdown of NR4A3 decreased apoptotic level after EBSS treatment. A pathway study indicated that IL-1ß-induced NF-κB activation was enhanced by NR4A3 overexpression and reduced by NR4A3 knockdown. We suggest that NR4A3 plays a pro-inflammatory role in the development of OA, and we also speculate that NR4A3 mainly regulates cartilage matrix-degrading gene expression under inflammatory conditions via the NF-κB pathway.
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Condrócitos/patologia , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Inflamação/patologia , Osteoartrite/patologia , Receptores de Esteroides/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Animais , Apoptose , Estudos de Casos e Controles , Células Cultivadas , Condrócitos/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Inflamação/genética , Inflamação/metabolismo , Masculino , Osteoartrite/genética , Osteoartrite/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Esteroides/genética , Receptores dos Hormônios Tireóideos/genética , Transdução de SinaisRESUMO
Diabetes mellitus (DM) is one of the prominent risk factors for pathological development and progression of tendinopathy. One feature of DM-related changes in tendinopathy is accumulation of advanced glycation end products (AGEs) in affected tendons. Pioglitazone (Pio), a peroxisome proliferator-activated receptor γ agonist, performs a protective effect against AGEs. The present study aimed to investigate the pathogenetic role of AGEs on tendon-derived stem cells (TDSCs) and to determine the effect of Pio on AGEs-induced TDSC dysfunctions. Results indicated that AGEs induced TDSC apoptosis as well as compensatory activation of autophagy. Pharmacologic activation/inhibition of autophagy leaded to alleviate/exacerbate apoptosis induced by AGEs. We further confirmed the effect of Pio on autophagy, which ameliorated apoptosis and abnormal calcification caused by AGEs both in vitro and in vivo. Thus, we suggest that Pio ameliorates the dysfunctions of TDSCs against AGEs by promoting autophagy, and we also reveal that Pio is a potential pharmacological choice for tendinopathy.
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Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Calcificação Fisiológica/efeitos dos fármacos , Produtos Finais de Glicação Avançada/metabolismo , Pioglitazona/farmacologia , Células-Tronco/efeitos dos fármacos , Tendões/efeitos dos fármacos , Animais , Masculino , PPAR gama/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Células-Tronco/metabolismo , Tendões/metabolismoRESUMO
Sulfamethoxazole (SMX) is widely employed as an antibiotic, while its residue in environment has become a common public concern. Using 100 mg/L SMX as the sole nutrient source, the acclimated sludge obtained by this study displayed an excellent SMX degradation performance. The addition of SMX resulted in significant microbiological differentiation within the acclimated sludge. Microbacterium (6.6%) was identified as the relatively dominant genera in metabolism group that used SMX as sole carbon source. Highly expressed proteins from this strain strongly suggested its essential role in SMX degradation, while the degradation of SMX by other strains (Thaurea 78%) in co-metabolism group appeared to also rely on this strain. The interactions of differentially expressed proteins were primarily involved in metabolic pathways including TCA cycle and nitrogen metabolism. It is concluded that the sulfonamides might serve not only as the carbon source but also as the nitrogen source in the reactor. A total of 24 intermediates were identified, 13 intermediates were newly reported. The constructed pathway suggested the mineralizing and nitrogen conversion ability towards SMX. Batch experiments also proved that the acclimated sludge displayed ability to biodegrade other sulfonamides, including SM2 and SDZ and SMX-N could be removed completely.
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Esgotos , Sulfametoxazol , Sulfametoxazol/metabolismo , Esgotos/microbiologia , Desnitrificação , Nitrogênio , Consórcios Microbianos , Proteômica , Antibacterianos/metabolismo , Sulfonamidas , Sulfanilamida , Carbono/metabolismoRESUMO
Candida tropicalis PNY, a novel dimorphic strain with the capacity of simultaneous carbon, nitrogen and phosphorus removal in anaerobic and aerobic conditions, was isolated from activated sludge. Dimorphism of C. tropicalis PNY had effect on removing nitrogen and phosphorous and slightly affected COD removal under aerobic condition. Sample with high hypha formation rate (40 ± 5%) had more removal efficiencies of NH4+-N (50 mg/L) and PO43--P (10 mg/L), which could achieve 82.19% and 97.53%, respectively. High hypha cells dosage exhibited good settleability and filamentous overgrowth was not observed. According to label-free quantitative proteomics assays. Up-regulated proteins involved in the mitogen-activated protein kinase (MAPK) pathway indicated the active growth and metabolism process of sample with high hypha formation rate (40 ± 5%). And proteins concerning about glutamate synthetase and SPX domain-contain protein explain for the nutrient removal mechanism including assimilation of ammonia and polyphosphates synthesis.
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Candida tropicalis , Esgotos , Candida tropicalis/metabolismo , Eliminação de Resíduos Líquidos , Nitrogênio/metabolismo , Fósforo/metabolismo , Caracteres Sexuais , Reatores BiológicosRESUMO
The coupling of modified nanoscale zero-valent iron (nZVI) with organohalide-degrading bacteria provides a promising solution for the remediation of hexabromocyclododecane (HBCD)-contaminated environments. However, the interactions between modified nZVI and dehalogenase bacteria are intricate, and the mechanisms of synergistic action and electron transfer are not clear, and requires further specific investigation. In this study, HBCD was used as a model pollutant, and stable isotope analysis revealed that organic montmorillonite (OMt)-supported nZVI coupled with the degrading bacterial strain Citrobacter sp. Y3 (nZVI/OMt-Y3) can use [13C]HBCD as the sole carbon source and degrade or even mineralise it into 13CO2 with a maximum conversion rate of 100% within approximately 5 days. Analysis of the intermediates showed that the degradation of HBCD mainly involves three different pathways: dehydrobromination, hydroxylation, and debromination. The proteomics results showed that nZVI introduction promoted the transport of electrons and debromination. Combining the results from XPS, FTIR, and Raman spectroscopy with the analysis results of proteinomics and biodegradation products, we verified the process of electron transport and proposed a metabolic mechanism of HBCD degradation by the nZVI/OMt-Y3. Moreover, this study provides insightful avenues and models for the further remediation of HBCD and other similar pollutants in the environment.
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Poluentes Ambientais , Hidrocarbonetos Bromados , Poluentes Químicos da Água , Ferro/química , Bentonita , Biodegradação Ambiental , Bactérias , Poluentes Químicos da Água/químicaRESUMO
Hexabromocyclododecane (HBCD) is a typical persistent organic pollutant that is widely detected in the environment. Despite the significant efforts put into its mineralisation, there is still a lack of microorganism resources that can completely mineralise HBCD. Stable isotope analysis revealed that the Citrobacter sp. Y3 can use [13C]HBCD as its sole carbon source and degrade or even mineralise it into 13CO2, with a maximum conversion rate of 100% in approximately 14 days. Strain Y3 could completely mineralise HBCD, which it used as its only carbon source, and six debromination enzymes related to HBCD degradation were found in Y3, including haloalkane dehalogenase (DhaA), haloacid dehalogenase (HAD), etc. A functional gene named HBCD-hd-1, encoding a HAD, was found to be upregulated during HBCD degradation and heterologously expressed in Escherichia coli. Recombinant E. coli with the HBCD-hd-1 gene transformed the typical intermediate 4-bromobutyric acid to 4-hydroxybutanoic acid and showed excellent degradation performance on HBCD, accompanied by nearly 100% bromine (Br) ion generation. The expression of HBCD-hd-1 in Y3 rapidly accelerated the biodegradation of HBCD. With HBCD as its sole carbon source, strain Y3 could potentially degrade HBCD, especially in a low-nutrient environment.
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Bromo , Hidrocarbonetos Bromados , Citrobacter/genética , Poluentes Orgânicos Persistentes , Escherichia coli/genética , Dióxido de Carbono , Hidrocarbonetos Bromados/análise , Redes e Vias Metabólicas , CarbonoRESUMO
Candida tropicalis sp. was isolated with predominant biodegradation capability to phenol compounds, even with high concentration or in acid environment. The biodegradation of phenol was evaluated at the following concentrations 10-1750 mg L-1, the strain exhibited well biodegradation efficiency. The maximum specific growth rate was 0.660 h-1 and the specific biodegradation rates was 0.47 mg (phenol) [(mg (VSS) h]-1. Differentially expressed genes were screened out, and results revealed a complete process of energy and carbon metabolism. The genes' arrangements and phylogenetic information showed the unique genetic characteristics of the strain. Catabolic pathways were reconstructed and some key phenol-degrading genes were obviously upregulated, including pheA, catA, OXCT and fadA. A notable detail that CMBL encoding carboxymethylenebutenolidase was speculated to be involved in a shortened pathway of phenol biodegradation, thereby contributing to the reconstruction of the novel phenol catabolic pathway through the hydrolases of dienelactone. Finally, key enzymes were verified by the analysis of specific activity.
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Candida tropicalis , Fenol , Biodegradação Ambiental , Candida tropicalis/genética , Candida tropicalis/metabolismo , Carbono/metabolismo , Genômica , Hidrolases/metabolismo , Cinética , Fenol/análise , Fenóis/análise , Filogenia , TranscriptomaRESUMO
The osteoarthritis (OA) symptoms cannot be fully remedied by using only a single functional component because of its complex pathogenesis. Herein, a MnO2 nanozyme-encapsulated hydrogel was fabricated via dispersing bovine serum albumin (BSA)-MnO2 (BM) nanoparticles (NPs) into a hyaluronic acid (HA)/platelet-rich plasma (PRP) gel network crosslinked by Schiff base reaction. Due to the self-healing and pH-responsive properties of Schiff base bonds, the hydrogel not only functioned as viscosupplementation but also exhibited pH-responsive release of BM NPs and growth factors in PRP. The BM NPs could attenuate the severe oxidative stress, and the PRP could promote chondrocyte proliferation. In a rat OA model, the HA/PRP/BM hydrogel markedly suppressed cartilage matrix degradation. Both the in vitro and in vivo studies showed that this novel hydrogel platform could inhibit the development of osteoarthritis through a synergetic effect of mechanical dissipation, depressing inflammation, facilitating cartilage repair, and thus has essential application prospects in OA treatment.
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Osteoartrite , Plasma Rico em Plaquetas , Animais , Ácido Hialurônico/farmacologia , Hidrogéis/química , Injeções Intra-Articulares , Compostos de Manganês , Osteoartrite/metabolismo , Óxidos , Plasma Rico em Plaquetas/química , Plasma Rico em Plaquetas/metabolismo , Ratos , Bases de Schiff , Resultado do TratamentoRESUMO
A new Candida tropicalis that simultaneously remove nitrogen and phosphorus, and degrade organic matters was isolated. Three continuous stirred tank reactors inoculated with C. tropicalis, activated sludge, and their co-existing system in aerobic condition were operated for 150 days. Results demonstrated that the inoculation of C. tropicalis in the co-existing system remarkably improved the carbon, nitrogen, and phosphorus removal efficiencies. The co-existing system had increased carbon, nitrogen, and phosphorus removal efficiencies (92%, 73%, and 63%, respectively); decreased biomass (reduced from 1200 mg/L to 500 mg/L); and C. tropicalis as the dominant strain. The relative abundance of traditional nitrogen- and phosphorus-removing microorganisms, such as Mycobacterium, Flavonifactor, and Devsia, increased in the co-existing system. Metagenomic analysis showed that the presence of the PCYT2, EPT1, and phnPP genes and more complexed metabolism pathways in the co-existing system might be responsible for the more activated metabolism process.
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Microbiota , Esgotos , Reatores Biológicos , Candida tropicalis/metabolismo , Carbono , Nitrogênio/metabolismo , Fósforo/metabolismo , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodosRESUMO
T2, a gram-positive bacterium capable of rapidly degrading tetrabromobisphenol A (TBBPA), and affiliated with the genus Enterobacter, was isolated for the first time from sludge that had been contaminated for several years. The TBBPA degradation data fitted the first-order model well. Under optimal conditions (pH of 7, temperature of 31 °C, TBBPA concentration of 5 mg L-1, and inoculum size of 5%), 99.4% of the initially added TBBPA was degraded after 48 h. TBBPA degradation fitted the first-order model with the half-life of 3.3 h. These results illustrated that the TBBPA degradation capability of strain T2 was significantly better than that of previously reported bacteria. A total of 17 intermediates were detected, among which five were reported for the first time. Whole-genome sequencing revealed that strain T2 had a chromosome with the total length of 4 854 376 bp and a plasmid with the total length of 21 444 bp. It harbored essential genes responsible for debromination, such as cyp450, gstB, gstA, and HADH, and genes responsible for subsequent complete mineralization, such as bioC, yrrM, Tam, and Ubil. A key protein of haloacid dehalogenases responsible for the biodegradation of TBBPA may also be involved in the regulation of TBBPA degradation in natural environment. In soil bioremediation experiments, strain T2 showed excellent environmental adaptation. It was able to biodegrade TBBPA and its typical intermediate bisphenol A efficiently. Therefore, it could potentially be applied to treat TBBPA-contaminated sites.
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Enterobacter , Bifenil Polibromatos , Biodegradação Ambiental , Enterobacter/genética , Enterobacter/metabolismo , Genômica , Cinética , Bifenil Polibromatos/metabolismoRESUMO
Micro/nanoplastic pollution is an emerging concern all over the world as it has a certain impact on the eco-environment and human health. In this study, cellulose/MgAl layered double hydroxides (LDHs) composite beads were prepared for the removal of polystyrene nanoparticles by utilizing the porous properties of cellulose and the unique positive charge of LDHs. The effects of pH, contact time, initial concentration, temperature, humic acid, and ionic strength on the attachment of nanoplastics were studied. The microstructure characteristics of the beads were also analyzed before and after the attachment of nanoplastics. The results indicate that nanoplastic attachment probably involves pore diffusion, hydrogen bonding, and electrostatic interactions. The attachment behavior can be successfully explained using the pseudo-second-order kinetic model (R2 = 0.964), Webber-Morris (intra-particle diffusion) model, and Langmuir isotherm model (R2 = 0.978). The maximum attachment capacity can reach 6.08 mg/g. Therefore, the cellulose/LDHs composite beads can be a promising adsorbent for removing micro/nanoplastics.
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Poluentes Químicos da Água , Purificação da Água , Humanos , Adsorção , Celulose , Substâncias Húmicas , Hidróxidos/química , Cinética , Microplásticos , Poliestirenos , Água , Poluentes Químicos da Água/química , Purificação da Água/métodos , Magnésio , AlumínioRESUMO
Osteoarthritis (OA) is one of the most common chronic musculoskeletal disorder worldwide, representing a major source of disability, pain and socioeconomic burden. Yet the effective pharmaceutical treatments applied in the clinical works are merely symptomatic management with uncertainty around their long-term safety and efficacy, namely no drugs currently are capable of modulating the biological progression of OA. Here, we identified the potent anti-inflammatory as well as anti-oxidative properties of Nitidine Chloride (NitC), a bioactive phytochemical alkaloid extracted from natural herbs, in IL-1ß-treated rat articular chondrocytes (RACs), LPS-stimulated RAW 264.7 and rat osteoarthritic models in vivo. We demonstrated NitC remarkably inhibited the production of inflammatory mediators including COX2 and iNOS, suppressed the activation of MAPK and NF-κB cell signaling pathway and reduced the expression of extracellular matrix (ECM) degrading enzymes including MMP3, MMP9 and MMP13 in IL-1ß-treated RACs. Several emerging bioinformatics tools were performed to predict the underlying mechanism, the result of which indicated the potential reactive oxygen species (ROS) clearance potential of NitC. Further, NitC exhibited its anti-oxidative potential through ameliorating cellular senescence in IL-1ß-treated RACs and decreasing NLRP3 inflammasomes activation in LPS-stimulated RAW 264.7 via scavenging ROS. Additionally, X-ray, micro-CT and other experiments in vivo demonstrated that intra-articular injection of NitC significantly alleviated the cartilage erosion, ECM degradation and subchondral alterations in OA progression. In conclusion, the present study reported the potent anti-inflammatory and anti-oxidative potential of NitC in OA biological process, providing a promising therapeutic agent for OA management.
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Reactive oxygen species (ROS) play a critical role in the pathogenesis of osteoarthritis. The injection of a single antioxidant drug is characterized by low drug utilization and short residence time in the articular cavity, limiting the therapeutic effect of antioxidant drugs on osteoarthritis. Currently, the drug circulation half-life can be extended using delivery vehicles such as liposomes and microspheres, which are widely used to treat diseases. In addition, the composite carriers of liposomes and hydrogel microspheres can combine the advantages of different material forms and show stronger plasticity and flexibility than traditional single carriers, which are expected to become new local drug delivery systems. Chondroitin sulfate, a sulfated glycosaminoglycan commonly found in native cartilage, has good antioxidant properties and degradability and is used to develop an injectable chondroitin sulfate hydrogel by covalent modification with photo-cross-linkable methacryloyl groups (ChsMA). Herein, ChsMA microgels anchored with liquiritin (LQ)-loaded liposomes (ChsMA@Lipo) were developed to delay the progression of osteoarthritis by dual antioxidation. On the one hand, the antioxidant drug LQ wrapped in ChsMA@Lipo microgels exhibits significant sustained-release kinetics due to the double obstruction of the lipid membrane and the hydrogel matrix network. On the other hand, ChsMA can eliminate ROS through degradation into chondroitin sulfate monomers by enzymes in vivo. Therefore, ChsMA@Lipo, as a degradable and dual antioxidant drug delivery platform, is a promising option for osteoarthritis treatment. STATEMENT OF SIGNIFICANCE: Compared with the traditional single carrier, the composite carriers of hydrogel microspheres and liposome can complement the advantages of different materials, which shows stronger plasticity and flexibility, and is expected to become a new and efficient drug delivery system. ChsMA@Lipo not only attenuates IL-1ß-induced ECM degradation in chondrocytes but also inhibits the M1 macrophages polarization and the inflammasome activation. The obtained ChsMA@Lipo alleviates the progression of osteoarthritis in vivo, which is promising for osteoarthritis treatment.
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Microgéis , Osteoartrite , Antioxidantes/farmacologia , Sulfatos de Condroitina/farmacologia , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/uso terapêutico , Humanos , Hidrogéis/farmacologia , Hidrogéis/uso terapêutico , Inflamassomos , Lipídeos/uso terapêutico , Lipossomos , Microesferas , Osteoartrite/patologia , Espécies Reativas de OxigênioRESUMO
BACKGROUND: Osteoarthritis (OA) is a debilitating disease that inflicts intractable pain, a major problem that humanity faces, especially in aging populations. Stem cells have been used in the treatment of many chronic diseases, including OA. Cartilage progenitor/stem cells (CPSCs) are a type of stem cells with the ability to self- renew and differentiate. They hold a promising future for the understanding of the progression of OA and for its treatment. Previous studies have reported the relationship between mitochondrial dynamics and mesenchymal stem cell (MSC) proliferation, differentiation and aging. Mitochondrial dynamic and morphology change during stem cell differentiation. METHODS: This study was performed to access the relationship between mitochondrial dynamics and chondrogenic differentiation of CPSCs. Mitochondrial fusion and fission levels were measured during the chondrogenic differentiation process of CPSCs. After that, we used mitochondrial fusion promoter to induce fusion in CPSCs and then the chondrogenic markers were measured. Transmission electron microscopy (TEM) and confocal microscopy were used to capture the mass and fusion status of mitochondria. Lentiviruses were used to detect the role of mitofusin 2 (Mfn2) in CPSC chondrogenic differentiation. In vivo, Mfn2 was over-expressed in sheets of rat CPSCs, which were then injected intra-articularly into the knees of rats. RESULTS: Mitochondrial fusion markers were upregulated during the chondrogenic induction process of CPSCs. The mass of mitochondria was higher in differentiated CPSC, and the fusion status was obvious relative to un-differentiated CPSC. Chondrogenesis of CPSCs was upregulated with the induction by mitochondrial fusion promoter. Mfn2 over-expression significantly increased chondrocyte-specific gene expression and reversed OA through NOTCH2 signal pathway. CONCLUSIONS: Our study demonstrated that the mitochondrial fusion promotes chondrogenesis differentiation of CPSCs. Mfn2 accelerates the chondrogenesis differentiation of CPSCs through Notch2. In vivo, Mfn2-OE in sheets of rCPSCs ameliorated OA in the rat model.
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Células-Tronco Mesenquimais , Osteoartrite , Animais , Cartilagem/metabolismo , Diferenciação Celular , Células Cultivadas , Condrócitos/metabolismo , Condrogênese/genética , Células-Tronco Mesenquimais/metabolismo , Dinâmica Mitocondrial/genética , Osteoartrite/metabolismo , Ratos , Receptor Notch2/metabolismo , Transdução de Sinais , Células-Tronco/metabolismoRESUMO
Osteoarthritis (OA) is an age-related disorder and an important cause of disability that is characterized by a senescence-associated secretory phenotype and matrix degradation leading to a gradual loss of articular cartilage integrity. Mitochondria, as widespread organelles, are involved in regulation of complex biological processes such as energy synthesis and cell metabolism, which also have bidirectional communication with the nucleus to help maintain cellular homeostasis and regulate adaptation to a broad range of stressors. In light of the evidence that OA is strongly associated with mitochondrial dysfunction. In addition, mitochondria are considered to be the culprits of cell senescence, and mitochondrial function changes during ageing are considered to have a controlling role in cell fate. Mitochondrial dysfunction is also observed in age-related OA, however, the internal mechanism by which mitochondrial function changes with ageing to lead to the development of OA has not been elucidated. In this study, we found that the expression of Lon protease 1 (LONP1), a mitochondrial protease, was decreased in human OA cartilage and in ageing rat chondrocytes. Furthermore, LONP1 knockdown accelerated the progression and severity of osteoarthritis, which was associated with aspects of mitochondrial dysfunction including oxidative stress, metabolic changes and mitophagy, leading to downstream MAPK pathway activation. Antioxidant therapy with resveratrol suppressed oxidative stress and MAPK pathway activation induced by LONP1 knockdown to mitigate OA progression. Therefore, our findings demonstrate that LONP1 is a central regulator of mitochondrial function in chondrocytes and reveal that downregulation of LONP1 with ageing contributes to osteoarthritis.