HAMP predicts a pivotal role in modulating the malignant behaviors of non-small cell lung cancer cells.

BACKGROUND: Hepcidin antimicrobial peptide (HAMP) is a small peptide hormone recognized for its role in iron metabolism and cancer treatment. The purpose of this study was to examine the influence of HAMP in NSCLC. METHODS: The profile of NSCLC cells and tissues was characterized via HAMP. Gain- or loss-of-function cell models of HAMP were constructed, and CCK8, colony formation, and Transwell analyses were used to confirm the influence of HAMP on NSCLC cells. Upstream and downstream HAMP mechanisms in NSCLC were also analysed. Dual-luciferase reporter and pull-down assays confirmed the associations of miR-873-5p with HAMP, miR-873-5p, and the lncRNA KCNQ1OT1/SNHG14/XIST. Moreover, a xenograft model was established in nude mice for confirming the role of HAMP in NSCLC cell growth. RESULTS: In addition, HAMP expression increased in NSCLC cells and tissues. In terms of cellular functions, the HAMP-overexpressing group exhibited elevated NSCLC cell proliferation, invasion, and migration. HAMP knockdown reversed these changes. Bioinformatics analysis indicated that miR-873-5p targeted HAMP, which affected the nuclear factor kappa B (NF-κB) pathway in NSCLC. HAMP activated the NF-κB pathway, which was negatively modulated by miR-873-5p. NF-κB inhibitor JSH-23 can partly suppress the proliferation, invasion, and migration in HAMP-overexpressed cells. Moreover, miR-873-5p was the target miRNA of long noncoding RNAs (lncRNAs), which included KCNQ1OT1, SNHG14, and XIST, and these three lncRNAs promoted HAMP. CONCLUSION: Noncoding RNA-mediated HAMP promotes NSCLC cell proliferation, migration, and invasion by initiating the NF-κB pathway.

Proteomic study of vitreous in proliferative diabetic retinopathy patients after treatment with aflibercept: a quantitative analysis based on 4D label-free technique.

AIM: To identify different metabolites, proteins and related pathways to elucidate the causes of proliferative diabetic retinopathy (PDR) and resistance to anti-vascular endothelial growth factor (VEGF) drugs, and to provide biomarkers for the diagnosis and treatment of PDR. METHODS: Vitreous specimens from patients with diabetic retinopathy were collected and analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analyses based on 4D label-free technology. Statistically differentially expressed proteins (DEPs), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway representation and protein interactions were analyzed. RESULTS: A total of 12 samples were analyzed. The proteomics results showed that a total of 58 proteins were identified as DEPs, of which 47 proteins were up-regulated and 11 proteins were down-regulated. We found that C1q and tumor necrosis factor related protein 5 (C1QTNF5), Clusterin (CLU), tissue inhibitor of metal protease 1 (TIMP1) and signal regulatory protein alpha (SIRPα) can all be specifically regulated after aflibercept treatment. GO functional analysis showed that some DEPs are related to changes in inflammatory regulatory pathways caused by PDR. In addition, protein-protein interaction (PPI) network evaluation revealed that TIMP1 plays a central role in neural regulation. In addition, CD47/SIRPα may become a key target to resolve anti-VEGF drug resistance in PDR. CONCLUSION: Proteomic analysis is an approach of choice to explore the molecular mechanisms of PDR. Our data show that multiple proteins are differentially changed in PDR patients after intravitreal injection of aflibercept, among which C1QTNF5, CLU, TIMP1 and SIRPα may become targets for future treatment of PDR and resolution of anti-VEGF resistance.

Research on distributed strain monitoring of a bridge based on a strained optical cable with weak fiber Bragg grating array.

The foundation of an intelligent highway network is the construction of a high-density distributed strain monitoring system, which is based on sensing elements that can sensitively capture external information. In this research, the development and application for the structure of a novel strained optical fiber cable based on the weak fiber Bragg grating (wFBG) arrays are discussed. A modulation and demodulation solution of wavelength division multiplexing combined with time division multiplexing is developed by utilizing the property by which the wavelength of the strained optical fiber cable is periodically switched. Further, the strain transfer model of the optical cable is analyzed hierarchically using the theory of elasticity. The strain transfer coefficients of the overhanging region and the gluing region are combined to deduce the sensitivity model of the strained optical fiber cable. Moreover, the finite element technique is integrated to optimize the structural parameters of the optical cable for high-sensitivity or large-scale range. The strained optical fiber cable based on wFBG arrays is applied to a steel-concrete composite bridge. The static and dynamic loading tests show that the sensing optical cable can be monitored for strain variation in order to realize the functions of lane identification, weighing vehicle tonnage as well as velocity discrimination.

Stereotactic ablative brachytherapy versus percutaneous microwave ablation for early-stage non-small cell lung cancer: a multicenter retrospective study.

BACKGROUND: To analyze the efficacy of stereotactic ablative brachytherapy (SABT) and percutaneous microwave ablation (MWA) for the treatment of early-stage non-small cell lung cancer (NSCLC). METHODS: Patients with early-stage (T1-T2aN0M0) NSCLC who underwent CT-guided SABT or MWA between October 2014 and March 2017 at four medical centers were retrospectively analyzed. Survival, treatment response, and procedure-related complications were assessed. RESULTS: A total of 83 patients were included in this study. The median follow-up time was 55.2 months (range 7.2-76.8 months). The 1-, 3-, and 5-year overall survival (OS) rates were 96.4%, 82.3%, and 68.4% for the SABT group (n = 28), and 96.4%, 79.7%, and 63.2% for MWA group (n = 55), respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 92.9%, 74.6%, and 54.1% for SABT, and 92.7%, 70.5%, and 50.5% for MWA, respectively. There were no significant differences between SABT and MWA in terms of OS (p = 0.631) or DFS (p = 0.836). The recurrence rate was also similar between the two groups (p = 0.809). No procedure-related deaths occurred. Pneumothorax was the most common adverse event in the two groups, with no significant difference. No radiation pneumonia was found in the SABT group. CONCLUSIONS: SABT provided similar efficacy to MWA for the treatment of stage I NSCLC. SABT may be a treatment option for unresectable early-stage NSCLC. However, future prospective randomized studies are required to verify these results.

The novel miR-873-5p-YWHAE-PI3K/AKT axis is involved in non-small cell lung cancer progression and chemoresistance by mediating autophagy.

Non-small cell lung cancer (NSCLC) encompasses approximately 85% of all lung cancer cases and is the foremost cancer type worldwide; it is prevalent in both sexes and known for its high fatality rate. Expanding scientific inquiry underscores the indispensability of microRNAs in NSCLC. Here, we probed the impact of miR-873-5p on NSCLC development and chemoresistance. qRT‒PCR was used to measure the miR-873-5p level in NSCLC cells with or without chemoresistance. A model of miR-873-5p overexpression was constructed. The proliferation and viability of NSCLC cells were evaluated through CCK8 and colony formation experiments. Cell migration and invasion were monitored via Transwell assays. Western blotting was used to determine the levels of YWHAE, PI3K, AKT, EMT, apoptosis, and autophagy-related proteins. The sensitivity of NSCLC cells to the chemotherapeutic agent gefitinib was assessed. Additionally, the correlation of YWHAE with miR-873-5p was validated via a dual-luciferase reporter assay and RNA immunoprecipitation (RIP). Overexpressed miR-873-5p suppressed migration, proliferation, invasion, and EMT while concurrently stimulating apoptotic processes. miR-873-5p was downregulated in NSCLC cells resistant to gefitinib. Upregulating miR-873-5p reversed gefitinib resistance by inducing autophagy. YWHAE was confirmed to be a downstream target of miR-873-5p. YWHAE overexpression promoted the malignant behaviors of NSCLC cells and boosted tumor growth, while these effects were reversed following miR-873-5p overexpression. Subsequent investigations revealed that overexpressing YWHAE promoted PI3K/AKT pathway activation, with miR-873-5p displaying inhibitory effects on the YWHAE-mediated PI3K/AKT signaling cascade. miR-873-5p affects proliferation, invasion, migration, EMT, autophagy, and chemoresistance in NSCLC by controlling the YWHAE/PI3K/AKT axis.

Isotope engineering for spin defects in van der Waals materials.

Spin defects in van der Waals materials offer a promising platform for advancing quantum technologies. Here, we propose and demonstrate a powerful technique based on isotope engineering of host materials to significantly enhance the coherence properties of embedded spin defects. Focusing on the recently-discovered negatively charged boron vacancy center ([Formula: see text]) in hexagonal boron nitride (hBN), we grow isotopically purified h10B15N crystals. Compared to [Formula: see text] in hBN with the natural distribution of isotopes, we observe substantially narrower and less crowded [Formula: see text] spin transitions as well as extended coherence time T2 and relaxation time T1. For quantum sensing, [Formula: see text] centers in our h10B15N samples exhibit a factor of 4 (2) enhancement in DC (AC) magnetic field sensitivity. For additional quantum resources, the individual addressability of the [Formula: see text] hyperfine levels enables the dynamical polarization and coherent control of the three nearest-neighbor 15N nuclear spins. Our results demonstrate the power of isotope engineering for enhancing the properties of quantum spin defects in hBN, and can be readily extended to improving spin qubits in a broad family of van der Waals materials.

Quasi-Floquet Prethermalization in a Disordered Dipolar Spin Ensemble in Diamond.

Floquet (periodic) driving has recently emerged as a powerful technique for engineering quantum systems and realizing nonequilibrium phases of matter. A central challenge to stabilizing quantum phenomena in such systems is the need to prevent energy absorption from the driving field. Fortunately, when the frequency of the drive is significantly larger than the local energy scales of the many-body system, energy absorption is suppressed. The existence of this so-called prethermal regime depends sensitively on the range of interactions and the presence of multiple driving frequencies. Here, we report the observation of Floquet prethermalization in a strongly interacting dipolar spin ensemble in diamond, where the angular dependence of the dipolar coupling helps to mitigate the long-ranged nature of the interaction. Moreover, we extend our experimental observation to quasi-Floquet drives with multiple incommensurate frequencies. In contrast to a single-frequency drive, we find that the existence of prethermalization is extremely sensitive to the smoothness of the applied field. Our results open the door to stabilizing and characterizing nonequilibrium phenomena in quasiperiodically driven systems.

Characterization of circSEC11A as a novel regulator of Iodine-125 radioactive seed-induced anticancer effects in hepatocellular carcinoma via targeting ZHX2/GADD34 axis.

Iodine-125 (I-125) radioactive seed implantation is used for the local treatment of hepatocellular carcinoma (HCC), but the molecular mechanisms regulating its anticancer effects remain incompletely understood. In this study, we report that hsa_circ_0000647 (circSEC11A) is highly expressed after I-125 treatment in HCC cell lines and tissues and is a key regulator of I-125-induced anticancer effects. CircSEC11A acts as a competing endogenous RNA (ceRNA) to sponge miR-3529-3p, promoting the expression of zinc fingers and homeoboxes 2 (ZHX2) and enhancing I-125-induced anticancer effects. Dual-luciferase reporter assay, RNA pull-down, RNA immunoprecipitation, and fluorescence in situ hybridization were thereafter performed to verify the interaction among the molecules. Anticancer effects were detected using CCK-8, flow cytometry, TUNEL, EdU, transwell, and wound healing assays. Furthermore, ZHX2 transcriptionally inhibits GADD34, a negative regulator of endoplasmic reticulum stress (ERS), to enhance I-125- induced anticancer effects in vivo and in vitro. In conclusion, we characterized circSEC11A as a novel regulator of I-125-induced anticancer effects in HCC via miR-3529-3p/ZHX2/GADD34 axis-mediated ERS. Thus, circSEC11A may act as a potential therapeutic target for I-125 implantation in the clinic.

Lightweight image super-resolution based multi-order gated aggregation network.

Recently, Transformer-based models are taken much focus on solving the task of image super-resolution (SR) due to their ability to achieve better performance. However, these models combined huge computational cost during the computing self-attention mechanism. To solve this problem, we proposed a multi-order gated aggregation super-resolution network (MogaSRN) for low-level vision based on the concept of the MogaNet that is developed for high-level vision. The concept of the MogaSRN model is based on spatial multi-order context aggregation and adaptive channel-wise reallocation with the aid of the multi-layer perceptron (MLP). In contrast to the MogaNet model, in which the resolution of each stage decreased by a factor of 2, the resolution of the MogaSRN is stayed fixed during the deep features extraction. Moreover, the structure of the MogaSRN model is built based on balancing the performance and the model complexity. We evaluated our model based on five benchmark datasets concluding that the MogaSRN model can achieve significant improvements compared to the state-of-the-art. Moreover, our model shows the good visual quality and accuracy of the reconstruction. Finally, our model has 3.7 × faster runtime at the scale of × 4 compared to LWSwinIR with better performance.

Coherent dynamics of strongly interacting electronic spin defects in hexagonal boron nitride.

Optically active spin defects in van der Waals materials are promising platforms for modern quantum technologies. Here we investigate the coherent dynamics of strongly interacting ensembles of negatively charged boron-vacancy ([Formula: see text]) centers in hexagonal boron nitride (hBN) with varying defect density. By employing advanced dynamical decoupling sequences to selectively isolate different dephasing sources, we observe more than 5-fold improvement in the measured coherence times across all hBN samples. Crucially, we identify that the many-body interaction within the [Formula: see text] ensemble plays a substantial role in the coherent dynamics, which is then used to directly estimate the concentration of [Formula: see text]. We find that at high ion implantation dosage, only a small portion of the created boron vacancy defects are in the desired negatively charged state. Finally, we investigate the spin response of [Formula: see text] to the local charged defects induced electric field signals, and estimate its ground state transverse electric field susceptibility. Our results provide new insights on the spin and charge properties of [Formula: see text], which are important for future use of defects in hBN as quantum sensors and simulators.

Sequence Control in Asymmetric Terpolymerizations of meso-Epoxides, CO2 , and Phthalic Anhydride: Unprecedented Statistical Ester-Carbonate Distributions.

The statistical terpolymerization of epoxides, CO2 and cyclic anhydrides remains challenging, mainly because epoxide/CO2 and epoxide/anhydride copolymerizations typically proceed at considerably different rates. Herein, we report the syntheses of novel chiral terpolymers with unprecedented statistical distributions of carbonate and ester units (up to 50 % junction units) via the one-pot reaction of cyclohexene oxide, phthalic anhydride, and CO2 under mild conditions using enantiopure bimetallic aluminum-complex-based catalyst systems. Notably, all resulting terpolymers exhibited excellent enantioselectivities (≥96 % ee) that were independent of the carbonate-ester distribution. The statistical compositions of the carbonate and ester units in the resulting terpolymers were determined via 1 H and 13 C NMR spectroscopies. Furthermore, thermal properties were tuned by altering the ester content of the chiral terpolymer without influencing the enantioselective ring-opening step involving the meso-epoxide. This asymmetric terpolymerization methodology is also compatible with a variety of meso-epoxides to afford the corresponding terpolymers with 17 %-25 % junction units and excellent enantioselectivities (94 %-99 % ee). The present study is expected to provide new guidelines for preparing a broad range of biodegradable polymers with excellent enantioselectivities and adjustable properties.

Physical exercise attenuates age-related muscle atrophy and exhibits anti-ageing effects via the adiponectin receptor 1 signalling.

BACKGROUND: Although the adiponectin signalling exerts exercise-mimicking effects, whether this pathway contributes to the anti-ageing benefits of physical exercise has not been established yet. METHODS: Swim exercise training and wheel running were used to measure lifespan in the nematode Caenorhabditis elegans and skeletal muscle quality in mice, respectively. Muscle weight, muscle fibre cross-sectional area (CSA) and myonuclei number were used to evaluate muscle mass. RNA sequencing (RNA-Seq) analysis of skeletal muscle in exercised mice was used to study the underlying mechanisms. Western blot and immunofluorescence were performed to explore autophagy- and senescence-related markers. RESULTS: The C. elegans adiponectin receptor PAQR-1/AdipoR1, but not PAQR-2/AdipoR2, was activated (3.55-fold and 3.48-fold increases in p-AMPK on Days 1 and 6, respectively, P < 0.001), which was involved in lifespan extension in exercised worms. Exercise training increased skeletal muscle mass index (1.29-fold, P < 0.01), muscle weight (1.75-fold, P < 0.001), myonuclei number (1.33-fold, P < 0.05), muscle fibre CSA (1.39-fold, P < 0.05) and capillary abundance (2.19-fold, P < 0.001 for capillary density; 1.58-fold, P < 0.01 for capillary number) in aged mice. Physical exercise reduced protein (2.94-fold, P < 0.001) and mRNA levels (1.70-fold, P < 0.001) of p16INK4a , a marker for cellular senescence, in skeletal muscle of aged mice. These beneficial effects of exercise on skeletal muscle of mice were dependent on AdipoR1. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis for differentially expressed genes in skeletal muscle between exercised mice with and without AdipoR1 knockdown by RNA-Seq analysis revealed that several KEGG pathways, such as 'AMPK signalling pathway' (P < 0.001), 'FOXO signalling pathway' (P < 0.001) and 'autophagy' (P < 0.001) were overrepresented. Knockdown of FoxO3a inhibited exercise-mediated beneficial effects on skeletal muscle quality of mice by inhibiting autophagy/mitophagy (3.81-fold reduction in LC3-II protein, P < 0.001; 1.53-fold reduction in BNIP3 protein, P < 0.05). Knockdown of daf-16, the FoxO homologue in C. elegans, reduced autophagy (2.77-fold and 2.06-fold reduction in GFP::LGG-1 puncta in seam cells and the intestine, respectively, P < 0.05) and blocked lifespan extension by exercise in worms. CONCLUSIONS: Our findings provide insights into how the AdipoR1 pathway has an impact on the anti-ageing benefits of exercise and implicate that activation of the AdipoR1 signalling may represent a potential therapeutic strategy for reducing age-related loss of skeletal muscle.

Discovery of urea-based pleuromutilin derivatives as potent gram-positive antibacterial agents.

There is an urgent need to discover new antibacterial drugs and provide new treatment options for clinical antimicrobial resistance (AMR) pathogen infections. Inspired by the structural insights from analyzing the co-crystal structure of lefamulin with the ribosomes of S. aureus, a series of novel pleuromutilin derivatives of phenylene sulfide incorporated with urea moiety were designed and synthesized. The structure-activity relationship (SAR) study revealed that derivatives with urea in the meta position of phenylene sulfide had optimal antibacterial activities in vitro. Among them, 21h was the most potent one against Methicillin-resistant Staphylococcus aureus (MRSA) and clinical AMR Gram-positive bacteria with minimum inhibitory concentrations (MICs) in the range of 0.00195-0.250 µg/mL. And it possessed low resistance frequency, prolonged Post-Antibiotic Effect and the capability to overcome lefamulin-induced resistance. Furthermore, 21h exhibited potent antibacterial activity in vivo in both the thigh infection model and trauma infection model, representing a promising lead for the development of new antibiotics against Gram-positive pathogens, especially for AMR bacteria.

Utility of intra-procedural cone-beam computed tomography imaging for the determination of the artery of Adamkiewicz suspected by angiography during transarterial embolization for hemoptysis.

PURPOSE: To evaluate the role of cone-beam computed tomography (CT) performed for the determination of the artery of Adamkiewicz (AKA) suspected by angiography during trans-catheter bronchial artery embolization for hemoptysis. METHODS: In this retrospective study, 17 patients with hemoptysis who underwent cone-beam CT for evaluation of the AKA prior to arterial embolization from December 2014 to March 2022 were included. During the angiographic session, two interventional radiologists selected the possible AKAs that were defined as obscured hairpin-curved vessels arising from the dorsal branch of the intercostal arteries and running towards the midline in the arterially enhanced phase. Contrast-enhanced cone-beam CT was performed as an adjunct to angiography to determine whether the indefinite AKA was a real AKA based on whether it was found to connect to the anterior spinal artery. RESULTS: Selective cone-beam CT was performed at 17 possible AKAs detected by selective arteriogram of the intercostal artery (ICA). Cone-beam CT allowed for the determination of AKAs in 16 cases (94.1%). As a result of cone-beam CT findings, 9 of 16 study arteries (56.3%) were judged as definite AKAs, and the remaining 7 (43.7%) were judged as definitely not AKAs but as the musculocutaneous branching from the dorsal branch of the ICA. In 1 of 17 cases (5.9%), cone-beam CT could not determine the AKA because of poor image quality caused by inadequate breath holding. An additional anterior radiculomedullary artery arising from the dorsal branch of the lower ICA because of the inflow of the contrast medium through the anastomosis was detected in one case by conebeam CT but not by angiography. CONCLUSION: Intraprocedural enhanced cone-beam CT performed as an adjunctive technique to angiography is sufficient for confident determination of the AKA, which is essential for the operators to perform accurate and safe arterial embolization for hemoptysis.

Bronchial artery chemoembolization with drug-eluting beads versus bronchial artery infusion followed by polyvinyl alcohol particles embolization for advanced squamous cell lung cancer: A retrospective study.

PURPOSE: To analyze the efficacy and safety of bronchial arterial embolization (BACE) with drug-eluting beads (DEB) versus bronchial artery infusion (BAI) followed by polyvinyl alcohol (PVA) particle embolization for the treatment of advanced squamous cell lung cancer after the failure of systemic therapy. METHOD: Thirty-six patients with advanced squamous cell lung cancer who underwent bronchial arterial interventional therapy were included in this retrospective study. The DEB group (n = 20) was treated with nedaplatin and DEB loaded with gemcitabine, and the PVA group (n = 16) BAI with nedaplatin and gemcitabine followed by embolization with PVA particles. The treatment efficacy and complications were analyzed. RESULTS: The technical success rate was 100 %. The two groups were followed up for a median period of 8.9 months. The mean overall survival (OS) in the DEB group was 12.6 months (95 % CI:9.99-15.21), which was significantly longer than 8.14 months (95 % CI:6.07-10.2) in the PVA group (p = 0.007). The median progression-free survival (PFS) in the DEB group was 4.3 months (95 % CI:2.33-6.27), significantly longer than 3.2 months (95 % CI:2.55-3.85) in the PVA group (p = 0.030). The objective response rate (ORR) six months after the procedure was 50 % in the DEB group and 12.5 % in the PVA group. In the univariate and multivariate analyses, DEB-BACE was an independent prognostic factor for survival. Only grade 1 adverse events like fever, chest pain, and cough were seen. CONCLUSIONS: DEB-BACE may be a good choice for patients with advanced lung squamous cell carcinoma, as it could prolong OS and PFS without increasing adverse events.

Quantitative CT comparison between COVID-19 and mycoplasma pneumonia suspected as COVID-19: a longitudinal study.

OBJECTIVE: The purpose of this study was to compare imaging features between COVID-19 and mycoplasma pneumonia (MP). MATERIALS AND METHODS: The data of patients with mild COVID-19 and MP who underwent chest computed tomography (CT) examination from February 1, 2020 to April 17, 2020 were retrospectively analyzed. The Pneumonia-CT-LKM-PP model based on a deep learning algorithm was used to automatically quantify the number, volume, and involved lobes of pulmonary lesions, and longitudinal changes in quantitative parameters were assessed in three CT follow-ups. RESULTS: A total of 10 patients with mild COVID-19 and 13 patients with MP were included in this study. There was no difference in lymphocyte counts at baseline between the two groups (1.43 ± 0.45 vs. 1.44 ± 0.50, p = 0.279). C-reactive protein levels were significantly higher in MP group than in COVID-19 group (p < 0.05). The number, volume, and involved lobes of pulmonary lesions reached a peak in 7-14 days in the COVID-19 group, but there was no peak or declining trend over time in the MP group (p < 0.05). CONCLUSION: Based on the longitudinal changes of quantitative CT, pulmonary lesions peaked at 7-14 days in patients with COVID-19, and this may be useful to distinguish COVID-19 from MP and evaluate curative effects and prognosis.

Nigericin is effective against multidrug resistant gram-positive bacteria, persisters, and biofilms.

Multidrug-resistant (MDR) bacteria pose a significant clinical threat to human health, but the development of antibiotics cannot meet the urgent need for effective agents, especially those that can kill persisters and biofilms. Here, we reported that nigericin showed potent bactericidal activity against various clinical MDR Gram-positive bacteria, persisters and biofilms, with low frequencies of resistance development. Moreover, nigericin exhibited favorable in vivo efficacy in deep-seated mouse biofilm, murine skin and bloodstream infection models. With Staphylococcus aureus, nigericin disrupted ATP production and electron transport chain; cell death was associated with altered membrane structure and permeability. Obtaining nigericin-resistant/tolerant mutants required multiple rounds of challenge, and, cross-resistance to members of several antimicrobial classes was absent, probably due to distinct nigericin action with the GraSR two-component regulatory system. Thus, our work reveals that nigericin is a promising antibiotic candidate for the treatment of chronic or recurrent infections caused by Gram-positive bacteria.

Mesenchymal stem cell-derived exosomes inhibit the VEGF-A expression in human retinal vascular endothelial cells induced by high glucose.

AIM: To determine the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells (hUCMSCs) on the expression of vascular endothelial growth factor A (VEGF-A) in human retinal vascular endothelial cells (HRECs). METHODS: Exosomes were isolated from hUCMSCs using cryogenic ultracentrifugation and characterized by transmission electron microscopy, Western blotting and nanoparticle tracking analysis. HRECs were randomly divided into a normal control group (group A), a high glucose model group (group B), a high glucose group with 25 µg/mL (group C), 50 µg/mL (group D), and 100 µg/mL exosomes (group E). Twenty-four hours after coculture, the cell proliferation rate was detected using flow cytometry, and the VEGF-A level was detected using immunofluorescence. After coculture 8, 16, and 24h, the expression levels of VEGF-A in each group were detected using PCR and Western blots. RESULTS: The characteristic morphology (membrane structured vesicles) and size (diameter between 50 and 200 nm) were observed under transmission electron microscopy. The average diameter of 122.7 nm was discovered by nanoparticle tracking analysis (NTA). The exosomal markers CD9, CD63, and HSP70 were strongly detected. The proliferation rate of the cells in group B increased after 24h of coculture. Immunofluorescence analyses revealed that the upregulation of VEGF-A expression in HRECs stimulated by high glucose could be downregulated by cocultured hUCMSC-derived exosomes (F=39.03, P<0.01). The upregulation of VEGF-A protein (group C: F=7.96; group D: F=17.29; group E: F=11.89; 8h: F=9.45; 16h: F=12.86; 24h: F=42.28, P<0.05) and mRNA (group C: F=4.137; group D: F=13.64; group E: F=22.19; 8h: F=7.253; 16h: F=16.98; 24h: F=22.62, P<0.05) in HRECs stimulated by high glucose was downregulated by cocultured hUCMSC-derived exosomes (P<0.05). CONCLUSION: hUCMSC-derived exosomes downregulate VEGF-A expression in HRECs stimulated by high glucose in time and concentration dependent manner.

Protective effects of umbilical cord mesenchymal stem cell exosomes in a diabetic rat model through live retinal imaging.

AIM: To assess the protective effect of human umbilical cord mesenchymal stem cell exosomes (hucMSC-Exs) in a diabetic rat model by using a variety of retinal bioassays. METHODS: hucMSCs were subjected to differential ultracentrifugation for the collection of exosomes, and transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) using a NanoSight analysis system and Western blotting (WB) were used to analyze the expression of surface marker proteins such as CD63, CD9 and Calnexin. Streptozotocin (STZ) was injected into the intraperitoneal cavity to establish a diabetic model. Rats were divided into a normal group, diabetic group and hucMSC-Ex group. Fundus fluorescein angiography (FFA), optical coherence tomography (OCT) and other live imaging methods were used to observe the fundus of the rats. Finally, the eyeballs of rats from each group were collected for hematoxylin-eosin (HE) staining to further analyze the retinal structure. RESULTS: Through TEM, NTA and WB, we successfully isolated hucMSC-Exs. Subsequent FFA and OCT confirmed that hucMSC-Exs effectively prevented early retinal vascular damage and thickening of the retina. Finally, HE staining of rat retinal sections revealed that exosomes effectively alleviated retinal structure disruption caused by diabetes. CONCLUSION: hucMSC-Exs have a protective effect on the retina in diabetic rat through FFA, OCT and HE staining.

Protective effect of human umbilical cord mesenchymal stem cell-derived exosomes on rat retinal neurons in hyperglycemia through the brain-derived neurotrophic factor/TrkB pathway.

AIM: To explore whether human umbilical cord mesenchymal stem cell (hUCMSC)-derived exosomes (hUCMSC-Exos) protect rat retinal neurons in high-glucose (HG) conditions by activating the brain-derived neurotrophic factor (BDNF)-TrkB pathway. METHODS: hUCMSC-Exos were collected with differential ultracentrifugation methods and observed by transmission electron microscopy. Enzyme-linked immunosorbent assays (ELISAs) was used to quantify BDNF in hUCMSC-Exos, and Western blot was used to identify surface markers of hUCMSC-Exos. Rat retinal neurons were divided into 4 groups. Furthermore, cell viability, cell apoptosis, and TrkB protein expression were measured in retinal neurons. RESULTS: hUCMSCs and isolated hUCMSC-Exos were successfully cultured. All hUCMSC-Exos showed a diameter of 30 to 150 nm and had a phospholipid bimolecular membrane structure, as observed by transmission electron microscopy. ELISA showed the BDNF concentration of hUCMSCs-Exos was 2483.16±281.75. hUCMSCs-Exos effectively reduced the apoptosis of retinal neuron rate and improved neuron survival rate, meanwhile, the results of immunofluorescence verified the fluorescence intensity of TrKB in neurons increased. And all above effects were reduced by treated hUCMSCs-Exos with BDNF inhibitors. hUCMSC-Exos effectively reduced the apoptosis rate of retinal neurons by activating the BDNF-TrkB pathway in a HG environment. CONCLUSION: In the HG environment, hUCMSC-Exos could carry BDNF into rat retinal neurons, inhibiting neuronal apoptosis by activating the BDNF-TrkB pathway.