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BACKGROUND: Integrins are closely related to mechanical conduction and play a crucial role in the osteogenesis of human mesenchymal stem cells. Here we wondered whether tensile stress could influence cell differentiation through integrin αVß3. METHODS: We inhibited the function of integrin αVß3 of human mesenchymal stem cells by treating with c(RGDyk). Using cytochalasin D and verteporfin to inhibit polymerization of microfilament and function of nuclear Yes-associated protein (YAP), respectively. For each application, mesenchymal stem cells were loaded by cyclic tensile stress of 10% at 0.5 Hz for 2 h daily. Mesenchymal stem cells were harvested on day 7 post-treatment. Western blotting and quantitative RT-PCR were used to detect the expression of alkaline phosphatase (ALP), RUNX2, ß-actin, integrin αVß3, talin-1, vinculin, FAK, and nuclear YAP. Immunofluorescence staining detected vinculin, actin filaments, and YAP nuclear localization. RESULTS: Cyclic tensile stress could increase the expression of ALP and RUNX2. Inhibition of integrin αVß3 activation led to rearrangement of actin filaments and downregulated the expression of ALP, RUNX2 and promoted YAP nuclear localization. When microfilament polymerization was inhibited, ALP, RUNX2, and nuclear YAP nuclear localization decreased. Inhibition of YAP nuclear localization could reduce the expression of ALP and RUNX2. CONCLUSIONS: Cyclic tensile stress promotes early osteogenesis of human mesenchymal stem cells via the integrin αVß3-actin filaments axis. YAP nuclear localization participates in this process of human mesenchymal stem cells. Video Abstract.
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Células Madre Mesenquimatosas , Osteogénesis , Humanos , Citoesqueleto de Actina/metabolismo , Diferenciación Celular , Células Cultivadas , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Integrina alfaVbeta3/metabolismo , Células Madre Mesenquimatosas/metabolismo , Vinculina/metabolismoRESUMEN
Intravesical instillation has been considered an efficient route for detecting bladder cancer. However, only a small fraction of administered dose permeates into tumor tissues, and insufficient retention time limits their application. In this work, a novel intravesical bidirectional perfusion-like administered mode was developed to improve diagnostic accuracy of bladder tumor imaging. Specifically, the ultrasmall AuPd-P-FA Nanoprobe exhibit excellent NIR-II FL imaging performance due to electronic structure perturbation. Benefiting from the size advantage for kidney metabolism and FA targeting specificity, AuPd-P-FA could effectively administration to bladder tumor. When AuPd-P-FA reached maximum enrichment at 1 h post-injection, the localized and mild thermal energy produced upon laser irradiation activated a phase transition. This thermo-sensitive characteristic could prolong the retention time in bladder and the fluorescence signal could be clearly observed at 6 h post-injection with high accuracy. This novel intravesical bidirectional perfusion-like administered mode is expected to achieve a non-invasive diagnosis of early bladder cancer.
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Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/diagnóstico por imagen , Vejiga Urinaria/diagnóstico por imagen , Administración Intravesical , Perfusión , Imagen ÓpticaRESUMEN
Small-scale Solid Waste Thermal Treatment (SSWTT) is prevalent in remote Chinese locations. However, the ecological threats associated with heavy metals in resultant bottom ash remain undefined. This research study scrutinized such ash from eight differing sites, assessing heavy metal content, chemical form, and leaching toxicity. Most bottom ash samples met soil contamination standards for development land (GB36600-2018). However, levels of As, Cd, Cr, Cu, Ni, Pb, and Zn in some samples exceeded agricultural land standards GB15618-2018) by 1591%, 64,478%, 1880%, 3886%, 963%, 1110%, and 2011% respectively. Additionally, the As and Cd contents surpassed the construction land control limit value by 383% and 13% respectively. The mean values of the combined oxidizable and residual fraction (F3 + F4) for each heavy metal in all samples exceeded 65%, with Cr, Cu, Ni, and Pb reaching over 95%. All sample leaching concentrations, obtained via the HJ/T 299 procedure, were less than limits set by the identification standards for hazardous wastes (GB5085.3-2007). However, only the leaching concentrations of three samples via the leaching procedure HJ/T 300 met the "Solid Waste Landfill Pollution Control Standard" (GB 16889-2008). The results indicate that the location and type of SSWTT equipment play a crucial role in determining an appropriate solution for bottom ash management.
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Ceniza del Carbón , Metales Pesados , Ceniza del Carbón/análisis , Residuos Sólidos , Ciudades , Cadmio , Plomo , Metales Pesados/análisis , Medición de Riesgo , China , IncineraciónRESUMEN
Activatable fluorescence imaging in the second near-infrared window (NIR-II FL, 1000-1700 nm) is of great significance for accurate tumor diagnosis and targeting therapy. However, the clinical translation of most stimulus-activated nanoprobes is severely restricted by insufficient tumor response and out-of-synchronization theranostic process. Herein, an intelligent nanofactory AUC-GOx/Cel that possesses the "external supply, internal promotion" dual H2 O2 -amplification strategy for homologous activated tumor theranostic is designed. This nanofactory is constructed via a two-step biomineralization method using Au-doped Ag2 S as a carrier for glucose oxidase (GOx) and celastrol, followed by the growing of CuS to "turn off" the NIR-II FL signal. In the overexpressed H2 O2 tumor-microenvironment, the CuS featuring a responsive-degradability behavior can effectively release Cu ions, resulting in the "ON" state of NIR-II FL and Fenton-like activity. The exposed GOx can realize the intratumoral H2 O2 supply (external supply) via the effective conversion of glucose, and mediating tumor-starvation therapy; the interaction of celastrol and mitochondria can offer a substantial increase in the endogenous H2 O2 level (internal promotion), thereby significantly promoting the chemodynamic therapy (CDT) efficacy. Meanwhile, the dual H2 O2 -enhancement performance will in turn accelerate the degradation of AUC-GOx/Cel, and achieve a positive feedback mechanism for self-reinforcing CDT.
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Nanopartículas , Neoplasias , Línea Celular Tumoral , Cobre , Glucosa Oxidasa/metabolismo , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/terapia , Triterpenos Pentacíclicos/uso terapéutico , Nanomedicina Teranóstica/métodos , Microambiente TumoralRESUMEN
Helicity-resolved Raman spectra can provide an intricate view into lattice structural details. Through the analysis of peak positions, intensities, and circular polarized Raman signals, a wealth of information about chiral structure arrangement within the moiré superlattice, interlayer interaction strength, polarizability change in chemical bond, and beyond can be unveiled. However, the relationship between the circular polarization of high-frequency Raman and twist angle is still not clear. Here, we utilize helicity-resolved Raman spectroscopy to explore the interlayer interactions and the effect of the moiré superlattice in WS2/WSe2 heterostructures. For the out-of-plane Raman mode A1g of WS2 (A1g and 1E2g of WSe2), its intensity is significantly enhanced (suppressed) in WS2/WSe2 heterostructures when θ is less than 10° or greater than 50°. This observation could be attributed to the large polarizability changes in both W-S and W-Se covalent bonds. The circular polarization of 2LA(M) in WSe2 of the WS2/WSe2 heterostructure (θ < 10° or θ > 50°) is significantly enhanced compared to that of 2LA(M) in the monolayer WSe2. We deduce that the circular polarization of the Raman mode correlates with the proportion of high-symmetry area within a supercell of the moiré lattice. Our findings improve the understanding of twist-angle-modulated Raman modes in TMD heterostructures.
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Serine protease inhibitors (serpins) are the most numerous and widespread multifunctional protease inhibitor superfamily and are expressed by all eukaryotes. Serpin E2 (serpin peptidase inhibitor, clade E, member 2), a member of the serine protease inhibitor superfamily is a potent endogenous thrombin inhibitor, mainly found in the extracellular matrix and platelets, and expressed in numerous organs and secreted by many cell types. The multiple functions of serpin E2 are mainly mediated through regulating urokinase-type plasminogen activator (uPA, also known as PLAU), tissue-type plasminogen activator (tPA, also known as PLAT), and matrix metalloproteinase activity, and include hemostasis, cell adhesion, and promotion of tumor metastasis. The importance serpin E2 is clear from its involvement in numerous physiological and pathological processes. In this review, we summarize the structural characteristics of the Serpin E2 gene and protein, as well as its roles physiology and disease.
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Mild photothermal therapy (PTT) is a spatiotemporally controllable method that utilizes the photothermal effect at relatively low temperatures (40-45 °C) to especially eliminate tumor tissues with negligible side effects on the surrounding normal tissues. However, the overexpression of heat shock protein 70 (HSP70) and limited effect of single treatment drastically impede the therapeutic efficacy. Herein, the constructed multifunctional core-shell structured Ag-Cu@SiO2-PDA/GOx nanoreactors (APG NRs) that provide a dual inhibition of HSP70 strategy for the second near-infrared photoacoustic (NIR-II PA) imaging-guided combined mild PTT/chemodynamic therapy (CDT). The Ag-Cu cores can convert endogenous H2O2 to hydroxyl radical (â¢OH), which can induce lipid peroxidation (LPO) and further degrade HSP70. The polydopamine (PDA)/glucose oxidase (GOx) shells are utilized as the NIR-II photothermal agent to generate low temperature, and the GOx can reduce the energy supplies and inhibit energy-dependent HSP70 expression. Furthermore, both the generation of â¢OH and GOx-mediated energy shortage can reduce HSP70 expression to sensitize mild PTT under 1064 nm laser, and in turn, GOx and laser self-amplify the catalytic reactions of APG NRs for more production of â¢OH. The multifunctional nanoreactors will provide more potential possibilities for the clinical employment of mild PTT and the advancement of tumor combination therapies.
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The precise theranostics of rheumatoid arthritis (RA) remains a formidable challenge in clinical practice. Exploring novel applications of contemporary therapeutic approaches like chemo-radiotherapy is promising as a highly effective strategy for RA. Herein, a novel activatable nanoradiosensitizer-40 (denoted as IRnR-40) is developed, based on encapsulating the clinically approved drugs cisplatin (DDP) and indocyanine green (ICG) within a gelatin shell to achieve second near-infrared fluorescence (NIR-II FL) imaging-guided safe-dose synergetic chemo-radiotherapy. The high concentration of matrix metalloproteinase-9 (MMP-9) in the RA microenvironment plays a pivotal role in triggering the responsive degradation of IRnR-40, leading to the rapid release of functional molecules DDP and ICG. The released ICG serves the dual purpose of illuminating the inflamed joints to facilitate accurate target volume delineation for guiding radiotherapy, as well as acting as a real-time reporter for quantifying the release of DDP to monitor efficacy. Meanwhile, the released DDP achieves highly effective synergistic chemotherapy and radiosensitization for RA via the dual reactive oxygen species (ROS)-mediated mitochondrial apoptotic pathway. To sum up, this activatable nanoradiosensitizer IRnR-40 is believed to be the first attempt to achieve efficient NIR-II FL imaging-guided safe-dose chemo-radiotherapy for RA, which provides a new paradigm for precise theranostics of refractory benign diseases.
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Artritis Reumatoide , Cisplatino , Verde de Indocianina , Imagen Óptica , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/tratamiento farmacológico , Animales , Verde de Indocianina/administración & dosificación , Ratones , Imagen Óptica/métodos , Cisplatino/administración & dosificación , Cisplatino/uso terapéutico , Modelos Animales de Enfermedad , Fármacos Sensibilizantes a Radiaciones/administración & dosificación , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Humanos , Quimioradioterapia/métodosRESUMEN
The fast development of the waste incineration industry requires deeper insights into heating surface corrosion behavior at higher operating parameters with complex corrosion sources. This research investigates the corrosion behaviors of three types of plates, namely SA210-C, TP310, and 12CrMoV, when subjected to simulated flue gas and fly ash deposition simultaneously at temperatures ranging from 500â to 620â. The results indicate that the weight loss due to coupling corrosion was 2.5 to 84.5 times higher than that of gas-phase corrosion under the same operating conditions. Among the three stainless-steels, TP310 demonstrates superior corrosion resistance. It is worth noting that, under the gas-solid coupling corrosion conditions, we observed a distinct two-layer structure of corrosion products. Despite the fly ash simulants detaching over time, the two-layer structure remained unchanged. Based on the theory of eutectic molten salt formation, we propose that alkali metal chlorides only initiate the formation of the molten layer in the initial stage of corrosion. Furthermore, we offer additional suggestions for the mechanism of sustaining the molten layer in the absence of alkali metal chlorides.
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Cloro , Ceniza del Carbón , Incineración , Acero Inoxidable , Incineración/métodos , Corrosión , Ceniza del Carbón/química , Cloro/química , Acero Inoxidable/química , Vapor/análisis , Gases/químicaRESUMEN
INTRODUCTION: Non-alcohol fatty liver disease (NAFLD) has emerged as a public health issue, while no drugs have been specifically approved for treatment. This study aimed to examine the association between statin use and NAFLD occurrence, progression, and regression. METHODS: A cohort study was designed based on the Kailuan Study and electronic medical records (EMRs) from the Kailuan General Hospital. Participants aged 18 years with statin indication, including statin and non-statin users, were enrolled in 2010-2017. Propensity score-matched cohorts were also used. RESULTS: In the entire cohort, 21 229 non-NAFLD and 22 419 NAFLD patients (including 12 818 mild NAFLD) were included in the final analysis. After a median follow-up of about four years, the incidence of NAFLD occurrence and progression for statin users were lower than those for non-statin users (occurrence: 84.7 vs. 106.5/1000 person-years; progression: 60.7 vs. 75.5/1000 person-years). Compared with non-statin users, the risk of NAFLD occurrence (hazard ratio [HR]: 0.78, 95% confidence interval [CI]: 0.70-0.87) and regression (HR [95%CI], 0.71[0.60-0.84]) was decreased in statin users. The significantly negative association was only observed in those with cumulative statin duration ≥ 2 years (HR [95%CI] for occurrence 0.56 [0.46-0.69] vs. 0.52 [0.30-0.90] for progression) and those with low or moderate ASCVD-risk (HR [95%CI] for occurrence 0.74 [0.66-0.82] vs. 0.68 [0.57-0.80] for progression). No significant correlation was observed between statin use, statin use duration, and NAFLD regression. The PS-matched cohort had similar results. CONCLUSION: Taking statin may decrease the risk of NAFLD occurrence and progression in the population with statin indication, suggesting the potential role of statin in both primary and secondary prevention strategies for NAFLD, especially among those with low or moderate ASCVD risk.
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Rheumatoid arthritis (RA) is a systemic autoimmune disorder characterized by excessive proliferation of rheumatoid arthritis synovial fibroblasts (RASFs) and accumulation of inflammatory cytokines. Exploring the suppression of RASFs and modulation of the RA microenvironment is considered a comprehensive strategy for RA. In this work, specifically activated nanoagents (MAHI NGs) based on the hypoxic and weakly acidic RA microenvironment are developed to achieve a second near-infrared fluorescence (NIR-II FL)/photoacoustic (PA) dual-model imaging-guided multi-treatment. Due to optimal size, the MAHI NGs passively accumulate in the diseased joint region and undergo rapid responsive degradation, precisely releasing functionalized components: endogenous melanin-nanoparticles (MNPs), hydrogen gas (H2), and indocyanine green (ICG). The released MNPs play a crucial role in ablating RASFs within the RA microenvironment through photothermal therapy (PTT) guided by accurate PA imaging. However, the regional hyperthermia generated by PTT may exacerbate reactive oxygen species (ROS) production and inflammatory response following cell lysis. Remarkably, under the acidic microenvironment, the controlled release of H2 exhibits precise synergistic antioxidant and anti-inflammatory effects with MNPs. Moreover, the ICG, the second near-infrared dye currently approved for clinical use, possesses excellent NIR-II FL imaging properties that facilitate the diagnosis of deep tissue diseases and provide the right time-point for PTT.
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Artritis Reumatoide , Hidrógeno , Melaninas , Nanomedicina Teranóstica , Artritis Reumatoide/terapia , Artritis Reumatoide/metabolismo , Artritis Reumatoide/tratamiento farmacológico , Melaninas/metabolismo , Hidrógeno/farmacología , Nanomedicina Teranóstica/métodos , Animales , Nanopartículas/química , Humanos , Técnicas Fotoacústicas/métodos , Ratones , Verde de Indocianina , Modelos Animales de Enfermedad , Terapia Fototérmica/métodos , Fibroblastos/metabolismo , Fibroblastos/efectos de los fármacosRESUMEN
Neuropathic pain is a severe and debilitating condition caused by damage to the peripheral nerve or central nervous system. Although several mechanisms have been identified, the underlying pathophysiology of neuropathic pain is still not fully understood. Unfortunately, few effective therapies are available for this condition. Therefore, there is an urgent need to investigate the underlying mechanisms of neuropathic pain to develop more effective treatments. Long non-coding RNAs (lncRNAs) have recently gained attention due to their potential to modulate protein expression through various mechanisms. LncRNAs have been implicated in many diseases, including neuropathic pain. This study aimed to identify a novel lncRNA involved in neuropathic pain progression. The lncRNA microarray analysis showed that lncRNA Upregulated in Liver Cancer (HULC) was significantly upregulated in spinal cord tissue of sciatic nerve injury (SNI) rats. Further experiments confirmed that HULC promoted neuropathic pain progression and aggravated H2O2-induced Schwann cell injury. Mechanistically, Sine Oculis Homeobox 1 (SIX1) regulated the transcriptional expression of HULC, and both SIX1 and HULC were involved in neuropathic pain and Schwann cell injury. The results of our research indicate the existence of a previously unknown SIX1/HULC axis that plays a significant role in the development and progression of neuropathic pain, shedding light on the complex mechanisms that underlie this debilitating condition. These findings offer novel insights into the molecular pathways involved in neuropathic pain. This study underscores the potential of targeting lncRNAs as a viable approach to alleviate the suffering of patients with neuropathic pain.
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Neuralgia , Traumatismos de los Nervios Periféricos , ARN Largo no Codificante , Ratas , Animales , ARN Largo no Codificante/metabolismo , Peróxido de Hidrógeno/metabolismo , Células de Schwann , Traumatismos de los Nervios Periféricos/genética , Neuralgia/genética , Neuralgia/metabolismo , Estrés Oxidativo , Nervio CiáticoRESUMEN
Photodynamic therapy (PDT) has emerged as a promising strategy with higher selectivity and spatiotemporal control than conventional therapies. However, deep hypoxia in tumours has hampered the clinical use of PDT. In this study, a novel multifunctional cluster nanotheranostic agent (AuPd-BSA CN) was fabricated to generate a high amount of reactive oxygen species, regardless of oxygen dependence under 660 nm laser irradiation. The structure and properties of the AuPd-BSA CN were characterised using various technologies. The synthesised AuPd-BSA CN with high biocompatibility served as a superior photodynamic agent, showing prominent antitumour properties under laser irradiation. Additionally, the glucose oxidase-like activity of the AuPd-BSA CN synergistically enhanced the therapeutic performance. Notably, the intrinsic characteristics of the AuPd-BSA CN include dual-modal second near-infrared window fluorescence/photoacoustic imaging capabilities for monitoring and tracking the in vivo tumour therapeutic process. This work provides innovative insights into the AuPd-BSA CN as an "all-in-one" nanoplatform for cancer therapy.
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Neoplasias , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Nanomedicina Teranóstica/métodos , Fototerapia/métodos , Neoplasias/tratamiento farmacológico , Oxidación-Reducción , Microambiente TumoralRESUMEN
Tumor microenvironment (TME)-activated theranostics is a promising strategy to effectively identify small lesions, improve antitumor efficacy, and reduce the risk of undesired side effects. Hypoxia, as a common characteristic of TME, can serve as a preferred site for stimulus-dependent activation; however, tumor-hypoxia levels in various developmental stages exhibit different characteristics, severely limiting the response sensitivity. Herein, a circulating self-reinforcing hypoxic nanoamplifier (CGH NAs) is developed that utilizes a dual-chain reaction process (internal regulation, internal regulation) to achieve precise activation of NIR-II FL/photoacoustic (PA) imaging-guided synergistic therapy. Inspired by the positive correlation of nitroreductase (NTR) with hypoxia, the CGH NAs encapsulate CQ4T and GOx into NTR-sensitive hyaluronic acid-nitroimidazole (HA-NI) shell via a self-assembly approach, enabling aggregation-caused NIR-II FL quenching and tumor-accurate delivery. When CGH NAs efficiently accumulated in the tumor region, the intensive local NTR reduced hydrophobic -NO2 to hydrophilic -NH2, which lead to disassembly of CGH NAs. The released GOx could consume O2 (internal regulation) and glucose to cut off the energy supply, inducing tumor-starvation therapy; generate gluconic acid and H2O2 (oxidative stress). Meanwhile, the released CQ4T promoted rapid recovery of NIR-II FL signals for imaging-guided PDT, which could simultaneously deplete intratumoral O2 (external stimulation). Remarkably, the strengthened tumor-hypoxia levels in turn accelerated the NTR-responsive degradation of the CGH NAs, thereby achieving high-efficiency theranostic.
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INTRODUCTION: Use of polluting cooking fuels generates household air pollution (HAP) containing health-damaging levels of fine particulate matter (PM2.5). Many global epidemiological studies rely on categorical HAP exposure indicators, which are poor surrogates of measured PM2.5 levels. To quantitatively characterize HAP levels on a large scale, a multinational measurement campaign was leveraged to develop household and personal PM2.5 exposure models. METHODS: The Prospective Urban and Rural Epidemiology (PURE)-AIR study included 48-hour monitoring of PM2.5 kitchen concentrations (n = 2,365) and male and/or female PM2.5 exposure monitoring (n = 910) in a subset of households in Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania and Zimbabwe. PURE-AIR measurements were combined with survey data on cooking environment characteristics in hierarchical Bayesian log-linear regression models. Model performance was evaluated using leave-one-out cross validation. Predictive models were applied to survey data from the larger PURE cohort (22,480 households; 33,554 individuals) to quantitatively estimate PM2.5 exposures. RESULTS: The final models explained half (R2 = 54%) of the variation in kitchen PM2.5 measurements (root mean square error (RMSE) (log scale):2.22) and personal measurements (R2 = 48%; RMSE (log scale):2.08). Primary cooking fuel type, heating fuel type, country and season were highly predictive of PM2.5 kitchen concentrations. Average national PM2.5 kitchen concentrations varied nearly 3-fold among households primarily cooking with gas (20 µg/m3 (Chile); 55 µg/m3 (China)) and 12-fold among households primarily cooking with wood (36 µg/m3 (Chile)); 427 µg/m3 (Pakistan)). Average PM2.5 kitchen concentration, heating fuel type, season and secondhand smoke exposure were significant predictors of personal exposures. Modeled average PM2.5 female exposures were lower than male exposures in upper-middle/high-income countries (India, China, Colombia, Chile). CONCLUSION: Using survey data to estimate PM2.5 exposures on a multinational scale can cost-effectively scale up quantitative HAP measurements for disease burden assessments. The modeled PM2.5 exposures can be used in future epidemiological studies and inform policies targeting HAP reduction.
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Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Teorema de Bayes , Estudios de Cohortes , Culinaria , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Material Particulado/análisis , Estudios Prospectivos , Población RuralRESUMEN
Human skin fibroblasts (HSFs) approximate the multidirectional differentiation potential of mesenchymal stem cells, so they are often used in differentiation, cell cultures, and injury repair. They are an important seed source in the field of bone tissue engineering. However, there are a few studies describing the mechanism of osteogenic differentiation of HSFs. Here, osteogenic induction medium was used to induce fibroblasts to differentiate into osteoblasts, and the role of the mechanical sensitive element PDLIM5 in microfilament-mediated osteogenic differentiation of human fibroblasts was evaluated. The depolymerization of microfilaments inhibited the expression of osteogenesis-related proteins and alkaline phosphatase activity of HSFs, while the polymerization of microfilaments enhanced the osteogenic differentiation of HSFs. The evaluation of potential protein molecules affecting changes in microfilaments showed that during the osteogenic differentiation of HSFs, the expression of PDLIM5 increased with increasing induction time, and decreased under the state of microfilament depolymerization. Lentivirus-mediated PDLIM5 knockdown by shRNA weakened the osteogenic differentiation ability of HSFs and inhibited the expression and morphological changes of microfilament protein. The inhibitory effect of knocking down PDLIM5 on HSF osteogenic differentiation was reversed by a microfilament stabilizer. Taken together, these data suggest that PDLIM5 can mediate the osteogenic differentiation of fibroblasts by affecting the formation and polymerization of microfilaments.
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Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas con Dominio LIM/genética , Osteogénesis , Piel/citología , Fosfatasa Alcalina/metabolismo , Diferenciación Celular , Células Cultivadas , Fibroblastos/citología , Fibroblastos/metabolismo , Técnicas de Silenciamiento del Gen , Humanos , Piel/metabolismoRESUMEN
BACKGROUND: Integrins play a prominent role in osteogenic differentiation by transmitting both mechanical and chemical signals. Integrin expression is closely associated with tensile stress, which has a positive effect on osteogenic differentiation. We investigated the relationship between integrin αVß3 and tensile stress. METHODS: Human fibroblasts were treated with c (RGDyk) and lentivirus transduction to inhibit function of integrin αVß3. Y-15, cytochalasin D and verteporfin were used to inhibit phosphorylation of FAK, polymerization of microfilament and function of nuclear YAP, respectively. Fibroblasts were exposed to a cyclic tensile stress of 10% at 0.5 Hz, once a day for 2 h each application. Fibroblasts were harvested on day 4 and 7 post-treatment. The expression of ALP, RUNX2, integrin αVß3, ß-actin, talin-1, FAK, vinculin, and nuclear YAP was detected by Western blot or qRT-PCR. The expression and distribution of integrin αVß3, vinculin, microfilament and nuclear YAP. RESULTS: Cyclic tensile stress was found to promote expression of ALP and RUNX2. Inhibition of integrin αVß3 activation downregulated the rearrangement of microfilament and the expression of ALP, RUNX2 and nuclear YAP. When the polymerization of microfilament was inhibited the expression of ALP, RUNX2 and nuclear YAP were decreased. The phosphorylation of FAK induced by cyclic tensile stress reduced by the inhibition of integrin αVß3. The expression of ALP and RUNX2 was decreased by inhibition of phosphorylation of FAK and inhibition of nuclear YAP. CONCLUSIONS: Cyclic tensile stress promotes osteogenesis of human fibroblasts via integrin αVß3-microfilament axis. Phosphorylation of FAK and nuclear YAP participates in this process.
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Fibroblastos/citología , Integrina alfaVbeta3 , Osteogénesis , Citoesqueleto de Actina , Células Cultivadas , Humanos , Estrés MecánicoRESUMEN
Lamins are intermediate filaments that play a crucial role in sensing mechanical strain in the nucleus of cells. ß-catenin and megakaryoblastic leukemia-1 (MKL1) are critical signaling molecules that need to be translocated to the nucleus for their transcription in response to mechanical strain that induces osteogenesis. However, the exact molecular mechanism behind the translocation of these molecules has not been fully investigated. This study used 10% cyclic strain to induce osteogenesis in the murine osteoblast precursor cell line (MC3T3). The translocation of ß-catenin and MKL1 was studied by performing knockdown and overexpression of lamin A/C (LMNA). Cyclic strain increased the expression of osteogenic markers such as alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and enhanced ALP staining after seven days of incubation. Resultantly, MKL1 and ß-catenin were translocated in the nucleus from the cytoplasm during the stress-induced osteogenic process. Knockdown of LMNA decreased the accumulation of MKL1 and ß-catenin in the nucleus, whereas overexpression of LMNA increased the translocation of these molecules. In conclusion, our study indicates that both MKL1 and ß-catenin molecules are dependent on the expression of LMNA during strain-induced osteogenesis.