MCL1 inhibition: a promising approach to augment the efficacy of sorafenib in NSCLC through ferroptosis induction.

Ferroptosis, an iron-dependent form of regulated cell death, plays a crucial role in modulating the therapeutic response in non-small cell lung cancer (NSCLC) patients. Studies have identified the signal transducer and activator of transcription 3 (STAT3) and myeloid cell leukemia-1 (MCL1) as potential targets for sorafenib, which exhibits activities in inducing ferroptosis. However, the role of STAT3-MCL1 axis in sorafenib-induced ferroptosis in NSCLC is still unclear. This study provided evidence that ferroptosis is a critical driver of sorafenib-induced cell death in NSCLC, supported by the accumulation of lipid peroxidation products, indicative of oxidative stress-induced cell death. Additionally, both in vitro and in vivo experiments showed that ferroptosis contributed to a significant portion of the anti-cancer effects elicited by sorafenib in NSCLC. The noticeable accumulation of lipid peroxidation products in sorafenib-treated mice underscored the significance of ferroptosis as a contributing factor to the therapeutic response of sorafenib in NSCLC. Furthermore, we identified the involvement of the STAT3/MCL1 axis in sorafenib-induced antitumor activity in NSCLC. Mechanistically, sorafenib inhibited endogenous STAT3 activation and downregulated MCL1 protein expression, consequently unleashing the ferroptosis driver BECN1 from the BECN1-MCL1 complex. Conversely, there is an augmented association of BECN1 with the catalytic subunit of system Xc-, SLC7A11, whose activity to import cystine and alleviate lipid peroxidation is hindered upon its binding with BECN1. Notably, we found that MCL1 upregulation correlated with ferroptosis resistance in NSCLC upon sorafenib treatment. Our findings highlight the importance of sorafenib-triggered ferroptosis in NSCLC and offer a novel strategy to treat advanced NSCLC patients: by downregulating MCL1 and, in turn, predispose NSCLC cells to ferroptosis.

Microglia-mediated drug substance transfer promotes chemoresistance in brain tumors: insights from an in vitro co-culture model using GCV/Tk prodrug system.

BACKGROUND: It is well known that tumor-associated macrophages (TAMs) play essential roles in brain tumor resistance to chemotherapy. However, the detailed mechanisms of how TAMs are involved in brain tumor resistance are still unclear and lack a suitable analysis model. METHODS: A BV2 microglial cells with ALTS1C1 astrocytoma cells in vitro co-culture system was used to mimic the microglia dominating tumor stroma in the tumor invasion microenvironment and explore the interaction between microglia and brain tumor cells. RESULTS: Our result suggested that microglia could form colonies with glioma cells under high-density culturing conditions and protect glioma cells from apoptosis induced by chemotherapeutic drugs. Moreover, this study demonstrates that microglia could hijack drug substances from the glioma cells and reduce the drug intensity of ALTS1C1 via direct contact. Inhibition of gap junction protein prevented microglial-glioma colony formation and microglia-mediated chemoresistance. CONCLUSIONS: This study provides novel insights into how glioma cells acquire chemoresistance via microglia-mediated drug substance transferring, providing a new option for treating chemo-resistant brain tumors.

Tumor-Derived Membrane Vesicles Restrain Migration in Gliomas By Altering Collective Polarization.

Mechanobiology is a cornerstone in physiology. However, its role in biomedical applications remains considerably undermined. In this study, we employed cell membrane vesicles (CMVs), which are currently being used as nanodrug carriers, as tactile cues for mechano-regulation of collective cell behaviors. Gliomas, which are among the most resilient brain tumors and have a low patient survival rate, were used as the cell model. We observed that mechanical responses due to the application of glioma- or microglia-derived CMVs resulted in the doubling of the traction stress of glioma cell collectives with a 10-fold increase in the CMV concentration. Glioma-CMVs constrained cell protrusions and hindered their collective migration, with the migration speed of such cells declining by almost 40% compared to the untreated cells. We speculated that the alteration of collective polarization leads to migration speed changes, and this phenomenon was elucidated using the cellular Potts model. In addition to intracellular force modulation and cytoskeletal reorganization, glioma-CMVs altered drug diffusion within glioma spheroids by downregulating the mechano-signaling protein YAP-1 while also marginally enhancing the associated apoptotic events. Our results suggest that glioma-CMVs can be applied as an adjuvant to current treatment approaches to restrict tumor invasion and enhance the penetration of reagents within tumors. Considering the broad impact of mechano-transduction on cell functions, the regulation of cell mechanics through CMVs can provide a foundation for alternative therapeutic strategies.

Evaluating the biological effectiveness of boron neutron capture therapy by using microfluidics-based pancreatic tumor spheroids.

Background: The recent success of boron neutron capture therapy (BNCT) for cancer treatment has attracted considerable attention. Because irradiated neutrons penetrate deep into solid tumor tissue, BNCT efficacy is strongly influenced by cell pathophysiology in tumors. The tumor microenvironment critically influences tumor pathophysiology, but its effects on BNCT remain unexplored. Methods: We used a pancreatic tumor as a model to develop a high-throughput 3D tumor spheroid platform for evaluating BNCT efficacy under different microenvironment conditions. We expanded our system to serve as a transwell-like device in order to investigate the influence of stromal fibroblasts in the tumor microenvironment. Results: With the use of the proposed microfluidic chip and a laboratory pipette, more than 40 spheroids with controllable diameters (standard deviation <10%) could be cultured on a chip for more than 10 days. The response to BNCT from each spheroid can be monitored in real time. By using pancreatic tumor spheroids of two different diameters, we found that large spheroids, characterized by more hypoxic microenvironments, exhibited lower BNCT susceptibility. The cells in the hypoxic region expressed the HIF1-α signal, which is crucial in many therapeutic resistance signal pathways. In addition, the heterogeneous presence of stemness markers (Oct-4, Sox-2, and CD 44) implied that the underlying BNCT resistance mechanism was sophisticated. In the presence of fibroblasts, we found an association between ß-catenin nuclear translocation and BNCT resistance; membrane contacts from fibroblasts were found to be indispensable for translocation activation. Conclusions: In summary, by means of easily accessible microfluidic engineering, we developed tumor spheroids to recapture the pathophysiological characteristics of pancreatic tumors. Our data suggest that hypoxia and fibrosis can reduce BNCT efficacy in pancreatic cancer treatment. Considering the growing requirement for drug screening in personalized medicine, our findings and the developed method are expected to improve the fundamental understanding of BNCT and facilitate broad applications of BNCT in clinical settings.

Punicalagin Attenuates LPS-Induced Inflammation and ROS Production in Microglia by Inhibiting the MAPK/NF-κB Signaling Pathway and NLRP3 Inflammasome Activation.

Purpose: Neurodegenerative diseases are associated with neuroinflammation along with activation of microglia and oxidative stress, but currently lack effective treatments. Punicalagin is a natural bio-sourced product that exhibits anti-inflammatory effects on several chronic diseases; however, the anti-inflammatory and anti-oxidative effects on microglia have not been well examined. This study aimed to investigate the effects of punicalagin on LPS-induced inflammatory responses, NLRP3 inflammasome activation, and the production of ROS using murine microglia BV2 cells. Methods: BV2 cells were pre-treated with punicalagin following LPS treatment to induce inflammation. The secretion of NO and PGE2 was analyzed by Griess reagent and ELISA respectively, while the expressions of iNOS, COX-2, STAT3, ERK, JNK, and p38 were analyzed using Western blotting, the production of IL-6 was measured by ELISA, and the activity of NF-κB was detected using promoter reporter assay. To examine whether punicalagin affects NLRP3 inflammasome activation, BV2 cells were stimulated with LPS and then treated with ATP or nigericin. The secretion of IL-1ß was measured by ELISA. The expressions of NLRP3 inflammasome-related proteins and phospho IκBα/IκBα were analyzed using Western blotting. The production of intracellular and mitochondrial ROS was analyzed by flow cytometry. Results: Our results showed that punicalagin attenuated inflammation with reduction of pro-inflammatory mediators and cytokines including iNOS, COX-2, IL-1ß, and reduction of IL-6 led to inhibition of STAT3 phosphorylation by LPS-induced BV2 cells. Punicalagin also suppressed the ERK, JNK, and p38 phosphorylation, attenuated NF-κB activity, inhibited the activation of the NLRP3 inflammasome, and reduced the production of intracellular and mitochondrial ROS by LPS-induced BV2 cells. Conclusion: Our results demonstrated that punicalagin attenuated LPS-induced inflammation through suppressing the expression of iNOS and COX-2, inhibited the activation of MAPK/NF-κB signaling pathway and NLRP3 inflammasome, and reduced the production of ROS in microglia, suggesting that punicalagin might have the potential in treating neurodegenerative diseases.

Identification of Prognostic Genes in Gliomas Based on Increased Microenvironment Stiffness.

With a median survival time of 15 months, glioblastoma multiforme is one of the most aggressive primary brain cancers. The crucial roles played by the extracellular matrix (ECM) stiffness in glioma progression and treatment resistance have been reported in numerous studies. However, the association between ECM-stiffness-regulated genes and the prognosis of glioma patients remains to be explored. Thus, using bioinformatics analysis, we first identified 180 stiffness-dependent genes from an RNA-Seq dataset, and then evaluated their prognosis in The Cancer Genome Atlas (TCGA) glioma dataset. Our results showed that 11 stiffness-dependent genes common between low- and high-grade gliomas were prognostic. After validation using the Chinese Glioma Genome Atlas (CGGA) database, we further identified four stiffness-dependent prognostic genes: FN1, ITGA5, OSMR, and NGFR. In addition to high-grade glioma, overexpression of the four-gene signature also showed poor prognosis in low-grade glioma patients. Moreover, our analysis confirmed that the expression levels of stiffness-dependent prognostic genes in high-grade glioma were significantly higher than in low-grade glioma, suggesting that these genes were associated with glioma progression. Based on a pathophysiology-inspired approach, our findings illuminate the link between ECM stiffness and the prognosis of glioma patients and suggest a signature of four stiffness-dependent genes as potential therapeutic targets.

Microfluidic Microalgae System: A Review.

Microalgae that have recently captivated interest worldwide are a great source of renewable, sustainable and economical biofuels. The extensive potential application in the renewable energy, biopharmaceutical and nutraceutical industries have made them necessary resources for green energy. Microalgae can substitute liquid fossil fuels based on cost, renewability and environmental concern. Microfluidic-based systems outperform their competitors by executing many functions, such as sorting and analysing small volumes of samples (nanolitre to picolitre) with better sensitivities. In this review, we consider the developing uses of microfluidic technology on microalgal processes such as cell sorting, cultivation, harvesting and applications in biofuels and biosensing.

Aerosolized Hypertonic Saline Hinders Biofilm Formation to Enhance Antibiotic Susceptibility of Multidrug-Resistant Acinetobacter baumannii.

Limited therapeutic options are available for multidrug-resistant Acinetobacter baumannii (MDR-AB), and the development of effective treatments is urgently needed. The efficacy of four aerosolized antibiotics (gentamicin, amikacin, imipenem, and meropenem) on three different MDR-AB strains was evaluated using hypertonic saline (HS, 7 g/100 mL) as the aerosol carrier. HS aerosol effectively hindered biofilm formation by specific MDR-AB strains. It could also interrupt the swarming dynamics of MDR-AB and the production of extracellular polymeric substances, which are essential for biofilm progression. Biofilms protect the microorganisms from antibiotics. The use of HS aerosol as a carrier resulted in a decreased tolerance to gentamicin and amikacin in the biofilm-rich MDR-AB. Moreover, we tested the aerosol characteristics of antibiotics mixed with HS and saline, and results showed that HS enhanced the inhaled delivery dose with a smaller particle size distribution of the four antibiotics. Our findings demonstrate the potential of using "old" antibiotics with our "new" aerosol carrier, and potentiate an alternative therapeutic strategy to eliminate MDR-AB infections from a biofilm-disruption perspective.

Tissue Architecture Influences the Biological Effectiveness of Boron Neutron Capture Therapy in In Vitro/In Silico Three-Dimensional Self-Assembly Cell Models of Pancreatic Cancers.

Pancreatic cancer is a leading cause of cancer death, and boron neutron capture therapy (BNCT) is one of the promising radiotherapy techniques for patients with pancreatic cancer. In this study, we evaluated the biological effectiveness of BNCT at multicellular levels using in vitro and in silico models. To recapture the phenotypic characteristic of pancreatic tumors, we developed a cell self-assembly approach with human pancreatic cancer cells Panc-1 and BxPC-3 cocultured with MRC-5 fibroblasts. On substrate with physiological stiffness, tumor cells self-assembled into 3D spheroids, and the cocultured fibroblasts further facilitated the assembly process, which recapture the influence of tumor stroma. Interestingly, after 1.2 MW neutron irradiation, lower survival rates and higher apoptosis (increasing by 4-fold for Panc-1 and 1.5-fold for BxPC-3) were observed in 3D spheroids, instead of in 2D monolayers. The unexpected low tolerance of 3D spheroids to BNCT highlights the unique characteristics of BNCT over conventional radiotherapy. The uptake of boron-containing compound boronophenylalanine (BPA) and the alteration of E-cadherin can partially contribute to the observed susceptibility. In addition to biological effects, the probability of induced α-particle exposure correlated to the multicellular organization was speculated to affect the cellular responses to BNCT. A Monte Carlo (MC) simulation was also established to further interpret the observed survival. Intracellular boron distribution in the multicellular structure and related treatment resistance were reconstructed in silico. Simulation results demonstrated that the physical architecture is one of the essential factors for biological effectiveness in BNCT, which supports our in vitro findings. In summary, we developed in vitro and in silico self-assembly 3D models to evaluate the effectiveness of BNCT on pancreatic tumors. Considering the easy-access of this 3D cell-assembly platform, this study may not only contribute to the current understanding of BNCT but is also expected to be applied to evaluate the BNCT efficacy for individualized treatment plans in the future.

Sorting of cadherin-catenin-associated proteins into individual clusters.

The cytoplasmic tails of classical cadherins form a multiprotein cadherin-catenin complex (CCC) that constitutes the major structural unit of adherens junctions (AJs). The CCC in AJs forms junctional clusters, "E clusters," driven by cis and trans interactions in the cadherin ectodomain and stabilized by α-catenin-actin interactions. Additional proteins are known to bind to the cytoplasmic region of the CCC. Here, we analyze how these CCC-associated proteins (CAPs) integrate into cadherin clusters and how they affect the clustering process. Using a cross-linking approach coupled with mass spectrometry, we found that the majority of CAPs, including the force-sensing protein vinculin, interact with CCCs outside of AJs. Accordingly, structural modeling shows that there is not enough space for CAPs the size of vinculin to integrate into E clusters. Using two CAPs, scribble and erbin, as examples, we provide evidence that these proteins form separate clusters, which we term "C clusters." As proof of principle, we show, by using cadherin ectodomain monoclonal antibodies (mAbs), that mAb-bound E-cadherin forms separate clusters that undergo trans interactions. Taken together, our data suggest that, in addition to its role in cell-cell adhesion, CAP-driven CCC clustering serves to organize cytoplasmic proteins into distinct domains that may synchronize signaling networks of neighboring cells within tissues.

Dynamically and Spatially Controllable Albumin-Based Hydrogels for the Prevention of Postoperative Adhesion.

Since the degree of severity and the geometry of wounds vary, it is necessary to prepare an antiadhesive hydrogel that possesses dynamically controllable material properties, exhibits biodegradability, and possesses drug-releasing properties. Injectable, oxygen peroxide-sensitive, and photo-cross-linkable hydrogels that permit in situ dynamic and spatial control of their physicochemical properties were synthesized for the prevention of postoperative adhesion. Albumin is the most abundant protein in blood serum and serves as a carrier for several molecules that exhibit poor water solubility. It is therefore a suitable biomaterial for the fabrication of hydrogels since it presents a low risk of life-threatening complications and does not require immunosuppressive therapy for preventing graft rejection. The physicochemical properties of this hydrogel can then be spatially postadjusted via transdermal exposure to light to release drugs, depending on what is required for the injury. A significant reduction in postoperative peritoneal adhesion was observed in an animal model involving severe sidewall and bowel abrasions. This study demonstrated that the fabricated dually cross-linked, albumin-based hydrogels have great potential in such applications because they showed a low immune response, easy handling, full wound coverage, and tunable biodegradability. Precise spatial and controllable drug-release profiles may also be achieved via in situ transdermal post-tuning of the biomaterials, depending on the injury.

Stickiness of extracellular polymeric substances on different surfaces via magnetic tweezers.

Organic particle dynamics in the surface ocean plays a critical part in the marine carbon cycle. Aggregation of marine organic particles drives their downward transport to support various marine organisms on their transit to the sediments. Extracellular polymeric substances (EPS) from various microbes are a major contributor to the oceanic organic particle pool. The stickiness of EPS is expected to play a determining role in the aggregation process of particles; however, stickiness parameters are usually indirectly estimated through data fitting without direct assessment. Here a magnetic tweezer method was developed to quantitatively assess the stickiness of three model EPS produced by: Amphora sp., (diatom), Emiliania huxleyi (coccolithophore), and Sagittula stellata (bacteria), under different in vitro environmental conditions (salinity or EDTA complexed cations) and surface matrices (EPS-EPS and bare glass). Our results showed the stickiness of three microbial EPS decreasing for S. stellata > E. huxleyi > Amphora sp., in line with their decreasing protein-to-carbohydrate (P/C) ratios (related to their relative hydrophobicity). The data not only emphasize the importance of hydrophobicity on EPS stickiness, but also demonstrates that salinity and the nature of the substrate surface can influence the stickiness. Furthermore, we investigated stickiness between various types of EPS, and the observed selective stickiness of EPS between species may shed light on the interactions among heterogeneous marine microorganisms. Overall, this newly developed system provides a platform to assess the EPS stickiness to advance our understanding of the aggregation and sedimentation process of organic particles that are critical for the fate of organic carbon as well as for biofilm formation and microbial colonization of surfaces in the ocean.

In Vitro Evaluation of a Vibrating-Mesh Nebulizer Repeatedly Use over 28 Days.

This in vitro study evaluates the performance of a disposable vibrating-mesh nebulizer when used for 28 days. A lung model was used to simulate the breathing pattern of an adult with chronic obstructive pulmonary disease. The vibrating-mesh nebulizer was used for three treatments/day over 28 days without cleaning after each test. Results showed that the inhaled drug dose was similar during four weeks of use (p = 0.157), with 16.73 ± 4.46% at baseline and 15.29 ± 2.45%, 16.21 ± 2.21%, 17.56 ± 1.98%, and 17.13 ± 1.81%, after the first, second, third, and fourth weeks, respectively. The particle size distribution, residual drug volume, and nebulization time remained similar across four weeks of use (p = 0.110, p = 0.763, and p = 0.573, respectively). Mesh was inspected using optical microscopy and showed that approximately 50% of mesh pores were obscured after 84 runs, and light penetration through the aperture plate was significantly reduced after the 21st use (p < 0.001) with no correlation to nebulizer performance. We conclude that the vibrating-mesh nebulizer delivered doses of salbutamol solution effectively over four weeks without cleaning after each use even though the patency and clarity of the aperture plate were reduced by the first week of use.

Reactive Oxygen Species and Inflammatory Responses of Macrophages to Substrates with Physiological Stiffness.

Macrophages play essential roles in innate immunity and their functions can be activated by different signals at pathological sites. Concerning changes in the rigidity of the microenvironment as a disease progresses, the influence of stiffened substrates on macrophage physiology remains elusive. In this study, to evaluate the effect of stiffened substrates on macrophages, we used J774A.1 cells as the macrophage model to investigate its mechanoinflammation responses using engineered polymeric substrates with various physiological rigidities (approximately 0.6 to 100 kPa). Under lipopolysaccharide (LPS) and adenosine triphosphate (ATP) stress, approximately 4-fold higher cytoplasmic reactive oxygen species (ROS) were triggered in cells on the softer substrate, compared with cells on the stiff substrates. The enhanced ROS response was found to be regulated mainly by NADPH oxidase. Moreover, mitochondrial ROS (mtROS), a crucial intracellular ROS source, are produced in response to substrate rigidity. The results showed higher mtROS production when cells were grown on a soft substrate with LPS/ATP stimuli, and the mechano-mtROS alteration was eliminated by Rho kinase inhibitor Y-27632. We suggest that substrate rigidity can coincide with LPS/ATP in regulating the ROS generation of macrophages. As a result of the pivotal role of ROS in regulating inflammation, increased NLRP-3 inflammasome formation and higher NO secretion (an approximately 300% increase) were observed with macrophages grown on soft substrates. Although no substantial genomic distinction was identified in our experiments, based on the phenotypic and functional results, softer substrates prime macrophages toward the proinflammatory (M1)-like phenotype. In summary, this study demonstrated the mechanosensitive inflammatory response of macrophages and the alteration of ROS, as secondary inflammation signals, may contribute to the functional status of macrophages. These findings not only provide an alternative interpretation of the functional transitions of macrophages influenced by substrate rigidity but may also support the manipulation of the inflammatory responses of macrophages via physical microenvironment modifications.

Nano- and microplastics trigger secretion of protein-rich extracellular polymeric substances from phytoplankton.

The substantial increase in plastic pollution in marine ecosystems raises concerns about its adverse impacts on the microbial community. Microorganisms (bacteria, phytoplankton) are important producers of exopolymeric substances (EPS), which govern the processes of marine organic aggregate formation, microbial colonization, and pollutant mobility. Until now, the effects of nano- and micro-plastics on characteristics of EPS composition have received little attention. This study investigated EPS secretion by four phytoplankton species following exposure to various concentrations of polystyrene nano- and microplastics (55 nm nanoparticles; 1 and 6 µm microparticles). The 55 nm nanoparticles induced less growth/survival (determined on a DNA basis) and produced EPS with higher protein-to-carbohydrate (P/C) ratios than the exposure to microplastic particles. The amount of DNA from the four marine phytoplankton showed a higher negative linear correlation with increasing P/C ratios, especially in response to nanoplastic exposure. These results provide evidence that marine phytoplankton are quite sensitive to smaller-sized plastics and actively modify their EPS chemical composition to cope with the stress from pollution. Furthermore, the release of protein-rich EPS was found to facilitate aggregate formation and surface modification of plastic particles, thereby affecting their fate and colonization. Overall, this work offers new insights into the potential harm of different-sized plastic particles and a better understanding of the responding mechanism of marine phytoplankton for plastic pollution. The data also provide needed information about the fate of marine plastics and biogenic aggregation and scavenging processes.

Aldolase triggers metabolic reprogramming in colorectal cancer in hypoxia and stiff desmoplastic microenvironments.

Colorectal cancer (CRC) progression is highly associated with desmoplasia. Aerobic glycolysis is another distinct feature that appears during the CRC phase of the adenoma-carcinoma sequence. However, the interconnections between the desmoplastic microenvironment and metabolic reprogramming remain largely unexplored. In our in vitro model, we investigated the compounding influences of hypoxia and substrate stiffness, two critical physical features of desmoplasia, on the CRC metabolic shift by using engineered polyacrylamide gels. Unexpectedly, we found that compared to cells on a soft gel (approximately 1.5 kPa, normal tissue), cells on a stiff gel (approximately 8.7 kPa, desmoplastic tissue) exhibited reduced glucose uptake and glycolysis under both normoxia and hypoxia. In addition, the increasing substrate stiffness activated focal adhesion kinase (FAK)/phosphoinositide 3-kinase signaling, but not the mitochondrial respiratory inhibitor HIF-1α. However, the presence of aldolase B (ALDOB) reversed the CRC metabolic response to mechanosignaling; enhanced glucose uptake (approximately 1.5-fold) and aerobic glycolysis (approximately 2- to 3--fold) with significantly decreased mitochondrial oxidative phosphorylation. ALDOB also changed the response of CRC traction force, which is related to tumor metastasis, under hypoxia/normoxia. In summary, our data suggest a counter influence of hypoxia and substrate stiffness on glucose uptake, and ALDOB upregulation can reverse this, which drives hypoxia and stiff substrate to enhance the CRC aerobic glycolysis synergistically. The results not only highlight the potential impacts on metabolic reprogramming led by physical alterations in the microenvironment, but also extend our understanding of the essential role of ALDOB in CRC progression from a biophysical perspective.

Hypertonic saline enhances the efficacy of aerosolized gentamicin against Pseudomonas aeruginosa.

Aerosol inhalation is a promising strategy for the delivery of antibiotic agents. The efficacy of antibiotic treatment by aerosol inhalation is reduced by the formation of microbial biofilms in the respiratory system and excessive airway mucus build-up. Various approaches have been taken in order to overcome this barrier. In this in vitro study, we used hypertonic saline (7%, by weight), a low cost Food and Drug Administration-approved reagent, as an aerosol carrier to study its effects with the antibiotic, gentamicin, on the most common respiratory opportunistic pathogen, Pseudomonas aeruginosa, present in the mucus. The results indicated that the hypertonic saline aerosol containing gentamicin, a low cost antibiotic, significantly eliminated biofilm growth by ~3-fold, compared to the regular saline aerosol containing gentamicin. In addition to enhancing the penetration efficiency of drug molecules by 70%, bacterial motility also decreased (~50%) after treatment with aerosolised hypertonic saline. In conclusion, our results demonstrate that hypertonic saline can significantly enhance the efficacy of antibiotic aerosols, which may contribute to the current use of inhaled therapeutic compounds.

Nano-plastics induce aquatic particulate organic matter (microgels) formation.

The pervasive presence of plastic waste in the aquatic environment is widely viewed as one of the most serious environmental challenges for current and future generations. Microplastics ultimately degrade into nano and smaller-sizes. In turn, their biological and ecological impacts become more complicated and ambiguous. Nano-plastic particles travel from freshwater systems to estuarine and oceanic regions, during which they can interact with dissolved organic matter (DOM) to form microgels. Microgel formation is ubiquitous in aquatic systems, serving as a shunt between DOM and particulate organic matter (POM), as well as playing key roles in particle aggregation/sedimentation and pollutant transport. Currently the influences and mechanisms of the aggregation behavior and environmental fate of nano-plastics in different aquatic environments is poorly understood. Here, we report that 25 nm polystyrene nano-particles in lake and river water can promote POM (microgel) formation and accelerate the DOM-POM transition. We also adjusted various salinities of water samples to simulate scenarios based on plastic transport in waters flowing from rivers to seas. The results indicate polystyrene nanoparticles can interact with organic matter to form large organic particles, which may undergo further settling in response to specific salinity levels. Polystyrene-induced microgel formation appears to involve the hydrophobic interactions between plastics and DOM. Our data provides much needed information for modeling and understanding the retention and sedimentation of nano-plastics. We show that nano-plastics alter the DOM-POM shunt to cause unanticipated perturbations in the functionality of aquatic ecosystems.

Bavachin attenuates LPS-induced inflammatory response and inhibits the activation of NLRP3 inflammasome in macrophages.

BACKGROUND: Bavachin is a natural product isolated from Psoralea corylifolia L. that has been applied as a traditional medicine in Asian countries. However, the anti-inflammatory effects of bavachin on LPS-induced inflammation and NLRP3 inflammasome activation by macrophages remain unclear. PURPOSE: We investigated the anti-inflammatory effects of bavachin on LPS-activated murine macrophage cell line J774A.1 cells and murine peritoneal macrophages. METHODS: J774A.1 cells and murine peritoneal macrophages were pre-treated with bavachin following LPS treatment. The concentrations of NO, PGE2, IL-6 and IL-12p40 in cell culture supernatant were analyzed. The expressions of iNOS, COX-2, mPGES-1 and MAPKs were analyzed using Western blotting, while NF-κB activity was detected using promoter reporter assay. To examine the activation of NLRP3 inflammasome, J774A.1 cells were incubated with LPS, and then treated with bavachin following treatment with ATP. The concentration of IL-1ß in the cell culture supernatant was measured. The expressions of NLRP3, ASC, caspase-1 and IL-1ß were analyzed using Western blotting. The formation of inflammasome complex was observed by immunofluorescence microscopy. RESULTS: Bavachin suppressed LPS-induced NO and PGE2 production, and decreased iNOS and mPGES-1 expression. Bavachin also reduced LPS-induced IL-6 and IL-12p40 production and decreased the activation of MAPKs and NF-κB. Additionally, bavachin suppressed NLRP3 inflammasome-derived IL-1ß secretion, decreased caspase-1 activation, repressed mature IL-1ß expression, and inhibited inflammasome complex formation. Furthermore, bavachin also suppressed the production of NO, IL-6 and IL-12p40 by LPS-stimulated murine peritoneal macrophages. CONCLUSION: Our experimental results indicated anti-inflammatory effects of bavachin exhibit attenuation of LPS-induced inflammation and inhibit activation of NLRP3 inflammasome in macrophages. These results suggest that bavachin might have potential in treating inflammatory and autoimmune diseases.

Unexpected dose response of HaCaT to UVB irradiation.

Application of high-dosage UVB irradiation in phototherapeutic dermatological treatments present health concerns attributed to UV-exposure. In assessing UV-induced photobiological damage, we investigated dose-dependent effects of UVB irradiation on human keratinocyte cells (HaCaT). Our study implemented survival and apoptosis assays and revealed an unexpected dose response wherein higher UVB-dosage induced higher viability. Established inhibitors, such as AKT- (LY294002), PKC- (Gö6976, and Rottlerin), ERK- (PD98059), P38 MAPK- (SB203580), and JNK- (SP600125), were assessed to investigate UV-induced apoptotic pathways. Despite unobvious contributions of known signaling pathways in dose-response mediation, microarray analysis identified transcriptional expression of UVB-response genes related to the respiratory-chain. Observed correlation of ROS-production with UVB irradiation potentiated ROS as the underlying mechanism for observed dose responses. Inability of established pathways to explain such responses suggests the complex nature underlying UVB-phototherapy response.