Membrane Function Research Articles

Comparison between commercial media and TRIS-egg yolk extender in the refrigerated storage of collared peccary semen at 17 °C

To assist in the conservation of collared peccary, it is important to strengthen semen processing protocols. The aim of this study was to compare the effects of different commercial extenders (BTS; NUTRIXcell+ and PRIMXcell Ultra) and TRIS + egg yolk on the functional and morphological aspects of collared peccary semen stored at 17 °C for 48 hours. Ten ejaculates obtained by electroejaculation were divided into 4 aliquots and diluted in the respective extenders, then stored in a biological incubator at 17 °C for 12, 24, 36, and 48 hours. The samples were evaluated for kinetic parameters, membrane functionality, membrane integrity, mitochondrial activity, morphology, and sperm-binding capacity. At the end of storage (48 h), promising results were found for motility parameters, with TRIS + egg yolk (71.0 ± 4.6%) being more efficient than NUTRIXcell+ (38.9 ± 10.9%) (P < 0.05) and similar to BTS (42.9 ± 11.9%) and PRIMXcell Ultra (46.8 ± 10.8%). The results for membrane integrity and mitochondrial activity were around ∼30–50%, with TRIS being the only extender to preserve both parameters (58.9 ± 5.3 and 59.2 ± 5.6%) for up to 48 hours, respectively (P < 0.05). Finally, the extenders could guarantee 60% membrane functionality and ∼ 60–70% normal sperm morphology, as well as similar binding capacity among the groups. In conclusion, TRIS + egg yolk is effective in preserving the sperm parameters of collared peccary semen at 17 °C for 48 hours, while PRIMXcell Ultra and BTS are viable alternatives for this purpose.

Characterization of SIPs-type aquaporins and their roles in response to environmental cues in rice (Oryza sativa L.)

BackgroundAquaporins (AQPs) facilitate water diffusion across biological membranes and are involved in all phases of growth and development. Small and basic intrinsic proteins (SIPs) belong to the fourth subfamily of the plant AQPs. Although SIPs are widely present in higher plants, reports on SIPs are limited. Rice is one of the major food crops in the world, and water use is an important factor affecting rice growth and development; therefore, this study aimed to provide information relevant to the function and environmental response of the rice SIP gene family.ResultsThe rice (Oryza sativa L. japonica) genome encodes two SIP-like genes, OsSIP1 and OsSIP2, whose products are predominantly located in the endoplasmic reticulum (ER) membrane but transient localization to the plasma membrane is not excluded. Heterologous expression in a yeast aquaglyceroporin-mutant fps1Δ showed that both OsSIP1 and OsSIP2 made the cell more sensitive to KCl, sorbitol and H2O2, indicating facilitated permeation of water and hydrogen peroxide. In addition, the yeast cells expressing OsSIP2 were unable to efflux the toxic methylamine taken up by the endogenous MEP permeases, but OsSIP1 showed subtle permeability to methylamine, suggesting that OsSIP1 may have a wider conducting pore than OsSIP2. Expression profiling in different rice tissues or organs revealed that OsSIP1 was expressed in all tissues tested, whereas OsSIP2 was preferentially expressed in anthers and weakly expressed in other tissues. Consistent with this, histochemical staining of tissues expressing the promoter-β-glucuronidase fusion genes revealed their tissue-specific expression profile. In rice seedlings, both OsSIPs were upregulated to varied levels under different stress conditions, including osmotic shock, high salinity, unfavorable temperature, redox challenge and pathogen attack, as well as by hormonal treatments such as GA, ABA, MeJA, SA. However, a reduced expression of both OsSIPs was observed under dehydration treatment.ConclusionsOur results suggest that SIP-like aquaporins are not restricted to the ER membrane and are likely to be involved in unique membrane functions in substrate transport, growth and development, and environmental response.

Dynamic trend of lung fluid movement during exercise in heart failure: From lung imaging to alveolar-capillary membrane function

BackgroundIn chronic heart failure (HF), exercise-induced increase in pulmonary capillary pressure may cause an increase of pulmonary congestion, or the development of pulmonary oedema. We sought to assess in HF patients the exercise-induced intra-thoracic fluid movements, by measuring plasma brain natriuretic peptide (BNP), lung comets and lung diffusion for carbon monoxide (DLCO) and nitric oxide (DLNO), as markers of hemodynamic load changes, interstitial space and alveolar-capillary membrane fluids, respectively. Methods and resultsTwenty-four reduced ejection fraction HF patients underwent BNP, lung comets and DLCO/DLNO measurements before, at peak and 1 h after the end of a maximal cardiopulmonary exercise test. BNP significantly increased at peak from 549 (328–841) to 691 (382–1207, p < 0.0001) pg/mL and almost completely returned to baseline value 1 h after exercise. Comets number increased at peak from 9.4 ± 8.2 to 24.3 ± 16.7, returning to baseline (9.7 ± 7.4) after 1 h (p < 0.0001). DLCO did not change significantly at peak (from 18.01 ± 4.72 to 18.22 ± 4.73 mL/min/mmHg), but was significantly reduced at 1 h (16.97 ± 4.26 mL/min/mmHg) compared to both baseline (p = 0.0211) and peak (p = 0.0174). DLNO showed a not significant trend toward lower values 1 h post-exercise. ConclusionsModerate/severe HF patients have a 2-step intra-thoracic fluid movement with exercise: the first during active exercise, from the vascular space toward the interstitial space, as confirmed by comets increase, without any effect on diffusion, and the second, during recovery, toward the alveolar-capillary membrane, clearing the interstitial space but worsening gas diffusion.

Eco-friendly, low-cost, and antibacterial PEM boosts microbial fuel cell performance: Power generation and wastewater treatment

The performance of microbial fuel cells (MFCs) relies significantly on the proton exchange membrane (PEM). While effective, commercial options like Nafion 117 are costly and possess inherent weaknesses. Improving methods of PEMs are generally used, requiring spending energy and money and causing harmful and toxic chemicals to enter the environment. This study introduces an innovative approach by enhancing sulfonated polyether sulfone (SPES) properties using Falcaria vulgaris extract, offering a simple, environmentally friendly, cost-effective solution. The resulting green functionalized SPES membranes (GFSPESs) were evaluated in dual-chamber MFCs for energy production and textile wastewater treatment. SPES membranes were fabricated through a phase inversion process and subsequently functionalized using dip-coating, heating, and UV irradiation. Comprehensive analysis, including FTIR, EDS, SEM, and XPS, investigated the physicochemical structure of the PEMs. The plant extract exhibited notable benefits, enhancing hydrophilicity, proton conductivity, and antibacterial capability of the PEMs. The MFC with GFSPES-12 achieved a peak power output of 86.3 mW/m2 and a maximum current of 327 mA/m2, surpassing the performance of Nafion 117 and the bare SPES membranes. GFSPES-12 also exhibited a maximum ion exchange capacity (1.89 meq/g) and proton conductivity (2.98 mS/cm). In textile wastewater treatment, the GFSPESs demonstrated improved COD removal (96.12 %) and higher coulombic efficiency (42.23 %). Notably, GFSPES-12 exhibited an antibacterial efficiency exceeding 93.5 %. These findings affirm the efficient functionality of GFSPES membranes in dual-chamber MFCs, offering a promising and sustainable alternative for energy production and wastewater treatment.

Effect of selenium nanoparticles-supplemented INRA96 extender on Turkmen stallion sperm quality and lipid peroxidation during storage at 5°C

Oxidative damage to sperm during cooled storage is a significant issue, and selenium with antioxidant potential could be a solution. Moreover, nano-sized selenium offers more advantages compared to its ionic forms. This research aimed to assess the impact of selenium nanoparticles (SeNPs) supplemented in the INRA96 extender on the quality of Turkmen stallion sperm and lipid peroxidation during 72 h of cooled storage. A total of 25 ejaculates were treated using different concentrations of SeNPs, including no SeNPs (Control), 0.5 μM SeNPs (SeNPs 0.5), 1.0 μM SeNPs (SeNPs 1.0), and 1.5 μM SeNPs (SeNPs 1.5). The samples were then evaluated for sperm quality characteristics and lipid peroxidation. The results indicated a significant decrease (P < 0.05) in total and progressive motility, viability, and plasma membrane functionality after 48 h of cooled storage, along with an increase (P < 0.05) in spermatozoa abnormality and malondialdehyde (MDA) levels as the cooled storage time increased. However, SeNPs demonstrated an improvement (P < 0.05) in sperm total motility after 24 h of cooled storage, progressive motility throughout the entire 72-hour period, functionality of the plasma membrane after 48 hours of cooled storage, spermatozoa abnormality after 48 h of cooled storage, and semen MDA levels throughout the cooled storage (P < 0.05). In conclusion, the enrichment of the INRA96 extender with nano-sized selenium can enhance the quality of Turkmen stallion sperm during storage at 5 °C by increasing total, progressive, and curvilinear motilities, improving plasma membrane functionality, and reducing sperm abnormalities and lipid peroxidation.

Giant retinal pigment epithelium tears with membranous nephropathy: a case report and literature review

BackgroundKidney and eye diseases may be closely linked. Tears of the retinal pigment epithelium (RPE) have been reported to be related to kidney diseases, such as IgA nephropathy and light-chain deposition disease. However, pigment epithelium tears associated with membranous nephropathy have not been reported or systematically analysed.Case presentationA 68-year-old man presented with decreased right eye visual acuity. Optical coherence tomography (OCT) revealed cystic macular edema, localized serous detachment of the retina and loss of the outer retinal structure in the right eye and retinal pigment epithelium detachment (PED) combined with serous detachment of the retina in the left eye. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) revealed giant RPE tears in the right eye and exudative age-related macular degeneration in the left eye. The patient also suffered from severe membranous nephropathy-autoimmune glomerulonephritis. Renal biopsy immunofluorescence revealed a roughly granular pattern, with immunoglobulin G (IgA), immunoglobulin G (IgG), IgM, complement C3(Components 3), λ light chain and κ light chain subepithelial staining.ConclusionsIt is hypothesized that severe membranous nephropathy caused immune complex deposition on the surface of Bruch membrane, resulting in weakened adhesion between the RPE and Bruch membrane and impaired RPE pump function, combined with age-related macular degeneration, leading to giant RPE tears in the right eye. Close attention should be given to the ocular condition of patients with membranous nephropathy to facilitate timely treatment and avoid serious consequences.

Probing and imaging phospholipid dynamics in live cells

Abstract Distinct phospholipid species display specific distribution patterns across cellular membranes, which are important for their structural and signaling roles and for preserving the integrity and functionality of the plasma membrane and organelles. Recent advancements in lipid biosensor technology and imaging modalities now allow for direct observation of phospholipid distribution, trafficking, and dynamics in living cells. These innovations have markedly advanced our understanding of phospholipid function and regulation at both cellular and subcellular levels. Herein, we summarize the latest developments in phospholipid biosensor design and application, emphasizing the contribution of cutting-edge imaging techniques to elucidating phospholipid dynamics and distribution with unparalleled spatiotemporal precision.

Graphene in gas separation membranes—State-of-the-art and potential spoors

Graphene and derivatives have been frequently used to form advanced nanocomposites. A very significant utilization of polymer/graphene nanocomposite was found in the membrane sector. The up-to-date overview essentially highpoints the design, features, and advanced functions of graphene nanocomposite membranes towards gas separations. In this concern, pristine thin layer graphene as well as graphene nanocomposites with poly(dimethyl siloxane), polysulfone, poly(methyl methacrylate), polyimide, and other matrices have been perceived as gas separation membranes. In these membranes, the graphene dispersion and interaction with polymers through applying the appropriate processing techniques have led to optimum porosity, pore sizes, and pore distribution, i.e., suitable for selective separation of gaseous molecules. Consequently, the graphene derived nanocomposites brought about numerous revolutions in high performance gas separation membranes. The structural diversity of polymer/graphene nanocomposites has facilitated the membrane selective separation, permeation, and barrier processes especially in the separation of desired gaseous molecules, ions, and contaminants. Future research on the innovative nanoporous graphene-based membrane can overcome design/performance related challenging factors for technical utilizations.

Proteomic and phosphoproteomic reveal immune-related function of milk fat globule membrane in bovine milk of different lactation periods

Information regarding protein expression and phosphorylation modifications in the bovine milk fat globule membrane is scarce, particularly throughout various lactation periods. This study employed a complete proteome and phosphoproteome between bovine colostrum and mature milk. A total of 11 proteins were seen in both protein expression and phosphorylation levels. There were 400 proteins identified in only protein expression, and 104 phosphoproteins identified in only phosphorylation levels. A total of 232 significant protein characteristics were identified within the proteome and significant phosphorylation sites within 86 phosphoproteins of the phosphoproteome. Biological activities and pathways primarily exhibited associations with the immune system. Simultaneously, a comprehensive analysis of proteins and phosphorylation sites using a multi-omics approach. Hence, the data we have obtained has the potential to expand our understanding of how the bovine milk fat globule membrane might be utilized as a beneficial component in dairy products.

Molecular Interactions Between Egg White Peptides and Giant Unilamellar Vesicle Membranes: Effect of Peptide Localization on Membrane Fluidity.

Bioactive peptides have been shown to affect cell membrane fluidity, which is an important indicator of the cell membrane structure and function. However, the underlying mechanism of egg white-derived bioactive peptide regulation of cell membrane fluidity has not been elucidated yet. The cell membrane fluidity was investigated by giant unilamellar vesicles in the present study. The results showed that peptides TCNW, ADWAK, ESIINF, VPIEGII, LVEEY, and WKLC connect to membranes through intermolecular interactions, such as hydrogen bonding and regulated membrane fluidity, in a concentration-dependent way. In addition, peptides prefer to localize in the hydrophobic core of the bilayers. This study provides a theoretical basis for analyzing the localization of egg white bioactive peptides in specific cell membrane regions and their influence on the cell membrane fluidity.

Nanofabrication of citronellal with chitosan biopolymer to boost its efficacy against aflatoxin B1 and Aspergillus flavus mediated biodeterioration of active ingredient of Piper longum

The study reports the efficacy of nanofabricated citronellal inside the chitosan biopolymer (NeCn) against Aspergillus flavus growth, aflatoxin B1 (AFB1) production, and active ingredient biodeterioration (Piperine) in Piper longum L. The prepared NeCn was characterized by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), and Fourier Transform Infrared Spectroscopy (FTIR). The results revealed that the NeCn exhibited distantly improved antifungal (1.25 μL/mL) and AFB1 inhibition (1.0 μL/mL) compared to free Cn. The perturbances in membrane function, mitochondrial membrane potential, antioxidant defense system, and regulatory genes (Ver-1 and Nor-1) of AFB1 biosynthesis were reported as probable modes of action of NeCn. The NeCn (1.25 μL/mL) effectively protects the P. longum from A. flavus (78.8%), AFB1 contamination (100%), and deterioration of Piperine (62.39%), thus demonstrating its potential as a promising novel antifungal agent for food preservation.

The mechanism of action underlying antibacterial activity of a diterpene quinone derivative against Staphylococcus aureus through the in vitro and in silico assays

Background: The need for new antibacterials to combat resistance is still constrained by the availability of antibacterials that are safe to use. Diterpene quinone-derived compounds are proven to have antibacterial activity. However, their mechanism of action is unknown. Objective: This study aims to determine the mechanism of antibacterial action of a diterpene quinone (6O7AR) on Staphylococcus aureus through in vitro and in silico assays. Method: MIC tests were performed using microdilution, and MBC determinations were carried out on MHA media. In vitro assays were conducted using membrane permeabilizing with Tris, Triton X-100, and ATPase-inhibiting agents with NaN3. Docking was performed on 2XCT proteins in S. aureus bacteria using AutoDock Vina. Result: The MIC and MBC results of 6O7AR were 300 μM and 2400 μM, respectively. The in vitro assay result suggested that the antimicrobial activities of 6O7AR were associated with the inhibition of ATPase function and disrupting membrane function. The docking results showed that the compound possessed good interactions with the 2XCT proteins of S. aureus. Conclusion: 6O7AR exhibited good antibacterial activity. Based on in vitro and in silico assays, the mechanism of action of this compound is related to the disruption of bacterial membrane function, and it has the potential to inhibit the ATPase enzyme and the S. aureus gyrase.

Study of the structure and characterization of membranes reinforced with CuO-NPs/Graphene Oxide using bacterial cellulose extracted from Sargassum sp. for water nanofiltration system

Bacterial cellulose membranes find extensive applications in industries involving water purification, wastewater treatment, and biomedical uses. Nevertheless, prevailing membranes suffer from drawbacks like water flow hindrances and fouling susceptibility. Hence, the pressing need for more efficient and robust BC membranes. This study aims to assess the impact of a hybrid treatment involving Copper Oxide nanoparticles (CuO-NPs) and Graphene Oxide (GO) on bacterial nanocellulose membranes. The research employed two treatments: (1) control (BNCA), and (2) Bacterial cellulose infused with 0.5 wt% CuO-NPs/GO. The nanocellulose production involved a high-pressure homogenizer, followed by acetate nanocellulose synthesis and nanocomposite membrane functionalization with CuO nanoparticles. SEM, FTIR, and XRD analyses characterized the membranes. Successfully formed seaweed-derived bacterial cellulose had a thickness of 1-3 cm. Characterization showed it belonged to Cellulose type I with a crystalline degree ranging from 82.3% to 83.1%. FTIR analysis of dry BNCA membranes indicated changes in transmittance at 1738, 1554, and 764 cm-1 due to CuO-NPs/GO addition, altering the O-H bond in bacterial cellulose. Based on the results of the above research, it is evident that the Membrane Reinforced with CuO-NPs/Graphene Oxide has been successfully developed and holds potential as a water nanofiltration system.

Calmodulin-like protein MdCML15 interacts with MdBT2 to modulate iron homeostasis in apple.

BTB and TAZ domain proteins (BTs) function as specialized adaptors facilitating substrate recognition of the CUL3-RING ubiquitin ligase (CRL3) complex that targets proteins for ubiquitination in reaction to diverse pressures. Nonetheless, knowledge of the molecular mechanisms by which the apple scaffold protein MdBT2 responds to external and internal signals is limited. Here we demonstrate that a putative Ca 2+ sensor, calmodulin-like 15 (MdCML15), acts as an upstream regulator of MdBT2 to negatively modulate its functions in plasma membrane H+-ATPase regulation and iron deficiency tolerance. MdCML15 was identified to be substantially linked to MdBT2, and to result in the ubiquitination and degradation of the MdBT2 target protein MdbHLH104. Consequently, MdCML15 repressed the MdbHLH104 target, MdAHA8's expression, reducing levels of a specific membrane H+-ATPase. Finally, the phenotype of transgenic apple plantlets and calli demonstrated that MdCML15 modulates membrane H+-ATPase-produced rhizosphere pH lowering alongside iron homeostasis through an MdCML15-MdBT2-MdbHLH104-MdAHA8 pathway. Our results provide new insights into the relationship between Ca2+ signaling and iron homeostasis.

Chitosan‐Stabilized PtAu Nanoparticles with Multienzyme‐Like Activity for Mixed Bacteria Infection Wound Healing and Insights into Its Antibacterial Mechanism

Traditional antibacterial agents are often observed to be ineffective because bacteria evolved to strains with greater antibiotic resistance. Here, vigorous chitosan‐stabilized PtAu nanoparticles (CSPA) with multienzyme‐like activity are successfully fabricated, which serve an effective artificial nanozyme to enhance antibacterial activity for mixed bacterial infection wound treatment. Ultrasmall size CSPA exhibits excellent hydrophilicity and biocompatibility, possesses strong oxidase‐ and peroxidase‐like activity generating a substantial amount of ROS (, 1O2, ·OH) to cause oxidative damage to bacteria, also demonstrates nicotinamide adenine dinucleotide dehydrogenase‐like activity disrupting the bacterial respiratory chains, and subsequently impedes adenosine triphosphate production. CSPA exhibits favorable broad‐spectrum antibacterial activity at very low concentrations, prevents bacterial resistance, and completely inhibits bacterial biofilm formation. Antibacterial Mechanism of CSPA by the transcriptomics is further revealed that CSPA can induce bacterial oxidative stress, hinder bacterial energy metabolism, and disrupt the synthesis and function of bacterial cell walls and cell membranes. In vivo, CSPA inhibits the mixed bacterial population at the wound site and promotes wound healing in rats. This study introduces a novel antibacterial approach, providing important insight into the antibacterial mechanism of CSPA nanozymes and promoting the advancement of nanocatalytic materials in biomedical applications.

Predicting the Risk of Morbidity by GLIM-Based Nutritional Assessment and Body Composition Analysis in Oncologic Abdominal Surgery in the Context of Enhanced Recovery Programs : The PHase Angle Value in Abdominal Surgery (PHAVAS) Study.

Preoperative nutritional status and body structure affect short-term prognosis in patients undergoing major oncologic surgery. Bioimpedance vectorial analysis (BIVA) is a reliable tool to assess body composition. Low BIVA-derived phase angle (PA) indicates a decline of cell membrane integrity and function. The aim was to study the association between perioperative PA variations and postoperative morbidity following major oncologic upper-GI surgery. Between 2019 and 2022 we prospectively performed BIVA in patients undergoing surgical resection for pancreatic, hepatic, and gastric malignancies on the day before surgery and on postoperative day (POD) 1. Malnutrition was defined as per the Global Leadership Initiative on Malnutrition criteria. The PA variation (ΔPA) between POD1 and preoperatively was considered as a marker for morbidity. Uni and multivariable logistic regression models were applied. Overall, 542 patients with a mean age of 64.6 years were analyzed, 279 (51.5%) underwent pancreatic, 201 (37.1%) underwent hepatobiliary, and 62 (11.4%) underwent gastric resections. The prevalence of preoperative malnutrition was 16.6%. The overall morbidity rate was 53.3%, 59% in those with ΔPA<-0.5 versus 46% when ΔPA≥-0.5. Age [odds ratio (OR) 1.11; 95% confidence interval (CI) (1.00; 1.22)], pancreatic resections [OR 2.27; 95% CI (1.24; 4.18)], estimated blood loss (OR 1.20; 95% CI (1.03; 1.39)], malnutrition [OR 1.77; 95% CI (1.27; 2.45)], and ΔPA [OR 1.59; 95% CI (1.54; 1.65)] were independently associated with postoperative complications in the multivariate analysis. Patients with preoperative malnutrition were significantly more likely to develop postoperative morbidity. Moreover, a decrease in PA on POD1 was independently associated with a 13% increase in the absolute risk of complications. Whether proactive interventions may reduce the downward shift of PA and the complication rate need further investigation.

Insights into metal tolerance and resistance mechanisms in Trichoderma asperellum unveiled by de novo transcriptome analysis during bioleaching

This study investigates the genetic responses of the fungus Trichoderma asperellum (T. asperellum) during bioleaching of ore and tailing samples, comparing one-step, two-step, and spent media bioleaching processes. HPLC analysis quantified oxalic acid, citric acid, and propionic acids, with oxalic acid identified as the primary organic acid involved in metal bioleaching. Metal analysis revealed differences in recovery between ore and tailing samples and among bioleaching processes. The two-step bioleaching process yielded the highest zinc (>54%) and nickel (>60%) recovery in tailings and ore, respectively. Nickel's efficient recovery in ore bioleaching was attributed to the presence of manganese, while its precipitation as nickel oxalate in tailings hindered recovery. Additional metals such as Co, Mn, Mg, Cu, and As were also successfully recovered. Transcriptomic analyses showed significant upregulation of genes associated with biological processes and cellular components, particularly those related to cell membrane structure and function, indicating T. asperellum's adaptation to environmental stresses during metal bioleaching. These findings enhance our understanding of the diverse mechanisms influencing metal recovery rates in bioleaching processes.

Cell envelope structural and functional contributions to antibiotic resistance in Burkholderia cenocepacia.

Antibiotic activity is limited by the physical construction of the Gram-negative cell envelope. Species of the Burkholderia cepacia complex (Bcc) are known as intrinsically multidrug-resistant opportunistic pathogens with low permeability cell envelopes. Here, we re-examined a previously performed chemical-genetic screen of barcoded transposon mutants in B. cenocepacia K56-2, focusing on cell envelope structural and functional processes. We identified structures mechanistically important for resistance to singular and multiple antibiotic classes. For example, susceptibility to novobiocin, avibactam, and the LpxC inhibitor, PF-04753299, was linked to the BpeAB-OprB efflux pump, suggesting these drugs are substrates for this pump in B. cenocepacia. Defects in peptidoglycan precursor synthesis specifically increased susceptibility to cycloserine and revealed a new putative amino acid racemase, while defects in divisome accessory proteins increased susceptibility to multiple β-lactams. Additionally, disruption of the periplasmic disulfide bond formation system caused pleiotropic defects on outer membrane integrity and β-lactamase activity. Our findings highlight the layering of resistance mechanisms in the structure and function of the cell envelope. Consequently, we point out processes that can be targeted for developing antibiotic potentiators.IMPORTANCEThe Gram-negative cell envelope is a double-layered physical barrier that protects cells from extracellular stressors, such as antibiotics. The Burkholderia cell envelope is known to contain additional modifications that reduce permeability. We investigated Burkholderia cell envelope factors contributing to antibiotic resistance from a genome-wide view by re-examining data from a transposon mutant library exposed to an antibiotic panel. We identified susceptible phenotypes for defects in structures and functions in the outer membrane, periplasm, and cytoplasm. Overall, we show that resistance linked to the cell envelope is multifaceted and provides new targets for the development of antibiotic potentiators.

Luteolin rescues postmenopausal osteoporosis elicited by OVX through alleviating osteoblast pyroptosis via activating PI3K-AKT signaling

BackgroundRecently, osteoblast pyroptosis has been proposed as a potential pathogenic mechanism underlying osteoporosis, although this remains to be confirmed. Luteolin (Lut), a flavonoid phytochemical, plays a critical role in the anti-osteoporosis effects of many traditional Chinese medicine prescriptions. However, its protective impact on osteoblasts in postmenopausal osteoporosis (PMOP) has not been elucidated. PurposeThis research aimed to determine the effect of Lut in ameliorating PMOP by alleviating osteoblast pyroptosis and sustaining osteogenesis. Study designThis research was designed to investigate the novel mechanism of Lut in alleviating PMOP both in cell and animal models. MethodsOvariectomy-induced PMOP models were established in mice with/without daily gavaged of 10 or 20 mg/kg body weight Lut. The impact of Lut on bone microstructure, metabolism and oxidative stress was evaluated with 0.104 mg/kg body weight Estradiol Valerate Tablets daily gavaged as positive control. Network pharmacological analysis and molecular docking were employed to investigate the mechanisms of Lut in PMOP treatment. Subsequently, the impacts of Lut on the PI3K/AKT axis, oxidative stress, mitochondria, and osteoblast pyroptosis were assessed. In vitro, cultured MC3T3-E1(14) cells were exposed to H2O2 with/without Lut to examine its effects on the PI3K/AKT signaling pathway, osteogenic differentiation, mitochondrial function, and osteoblast pyroptosis. ResultsOur findings demonstrated that 20 mg/kg Lut, similar to the positive control drug, effectively reduced systemic bone loss and oxidative stress, and enhanced bone metabolism induced by ovariectomy. Network pharmacological analysis and molecular docking indicated that the PI3K/AKT axis was a potential target, with oxidative stress response and nuclear membrane function being key mechanisms. Consequently, the effects of Lut on the PI3K/AKT axis and pyroptosis were investigated. In vivo data revealed that the PI3K/AKT axis was deactivated following ovariectomy, and Lut restored the phosphorylation of key proteins, thereby reactivating the axis. Additionally, Lut alleviated osteoblast pyroptosis and mitochondrial abnormalities induced by ovariectomy. In vitro, Lut intervention mitigated the inhibition of the PI3K/AKT axis and osteogenesis, as well as H2O2-induced pyroptosis. Furthermore, Lut attenuated ROS accumulation and mitochondrial dysfunction. The effects of Lut, including osteogenesis restoration, anti-pyroptosis, and mitochondrial maintenance, were all reversed with LY294002 (a PI3K/AKT pathway inhibitor). ConclusionIn summary, Lut could improve mitochondrial dysfunction, alleviate GSDME-mediated pyroptosis and maintain osteogenesis via activating the PI3K/AKT axis, offering a new therapeutic strategy for PMOP.

Bioinspired Sonodynamic Nano Spray Accelerates Infected Wound Healing via Targeting and Disturbing Bacterial Metabolism

AbstractBacterial infections pose a major concern for the medical community, especially regarding wound healing. Traditional passive antibiotic therapies can be cytotoxic and lead to bacterial resistance, posing a continuing challenge to treat. Based on precision therapy, a novel targeted‐delivery nanosystem is developed to efficiently eliminate bacteria and promote bacteria‐infected wound healing. Macrophage membranes pre‐activated by Staphylococcus aureus (MMSa) are prepared. In doing so, Toll‐like receptors (TLRs), a typical pathogen‐associated molecular pattern (PAMP), are significantly higher than normal macrophage membranes (MM0). Subsequently, MMSa are coated onto ultrasound‐triggered piezocatalytic nano‐barium titanate (BaTiO3, BTO) surfaces, and these two components are assembled to form a novel targeting delivery nanosystem, namely BTO@MMSa. The in vitro and in vivo results demonstrate that the biocompatible BTO@MMSa nanosystem can target infected areas and rapidly generate reactive oxygen species (ROS) to kill bacteria under ultrasound (US) irradiation, as well as accelerate wound healing. Furthermore, prokaryotic RNA‐seq transcriptomics reveals that changes in bacterial membrane function and substance, and energy metabolism are responsible for the targeted antibacterial ability of BTO@MMSa with US. Compared to widely reported unselective antibacterial agents, this novel targeted delivery nanosystem has potential for precise bacterial infection treatment by using macrophage membrane functions.