Protein Leakage Research Articles

Sodium dodecyl sulfate‐coated silver nanoparticles accelerate antimicrobial potentials by targeting amphiphilic membranes

AbstractCompelling concerns about antimicrobial resistance and the emergence of multidrug‐resistant pathogens call for novel strategies to address these challenges. Nanoparticles show promising antimicrobial activities; however, their actions are hindered primarily by the bacterial hydrophilic–hydrophobic barrier. To overcome this, we developed a method of electrochemically anchoring sodium dodecyl sulfate (SDS) coatings onto silver nanoparticles (AgNPs), resulting in improved antimicrobial potency. We then investigated the antimicrobial mechanisms and developed therapeutic applications. We demonstrated SDS‐coated AgNPs with anomalous dispersive properties capable of dispersing in both polar and nonpolar solvents and, further, detected significantly higher bacteriostatic and bactericidal effects compared to silver ions (Ag+). Cellular assays suggested multipotent disruptions targeting the bacterial membrane, evidenced by increasing lactate dehydrogenase, protein and sugar leakage, and consistent with results from the transcriptomic analysis. Notably, the amphiphilic characteristics of the AgNPs maintained robust antibacterial activities for a year at various temperatures, indicating long‐term efficacy as a potential disinfectant. In a murine model, the AgNPs showed considerable biocompatibility and could alleviate fatal Salmonella infections. Collectively, by gaining amphiphilic properties from SDS, we offer novel AgNPs against bacterial infections combined with long‐term and cost‐effective strategies.

Amlodipine Ocular Delivery Restores Ferning Patterns and Reduces Intensity of Glycosylated Peak of Carrageenan-Induced Tear Fluid: An In-Silico Flexible Docking with IL-β1.

The tear ferning test can be an easy clinical procedure for the evaluation and characterization of the ocular tear film. The objective of this study was to examine the restoration of tear ferning patterns and reduction of glycosylation peak after amlodipine application in carrageenan-induced conjunctivitis. At the rabbit's upper palpebral region, carrageenan was injected for cytokine-mediated conjunctivitis. Ferning pattern and glycosylation of the tear fluid were characterized using various instrumental analyses. The effect of amlodipine was also examined after ocular instillation and flexible docking studies. Optical microscopy showed a disrupted ferning of the tear collected from the inflamed eye. FTIR of the induced tear fluid exhibited peaks within 1000-1200 cm-1, which might be due to the protein glycosylation absent in the normal tear spectrogram. The glycosylation peak reduced significantly in the tear sample collected from the amlodipine-treated group. Corresponding energy dispersive analysis showed the presence of sulphur, indicating protein leakage from the lacrimal gland in the induced group. The disappearance of sulphur from the treated group indicated its remedial effect. The flexible docking studies revealed a stronger binding mode of amlodipine with Interleukin-1β (IL-1β). The reduction in the intensity of the glycosylated peak and the restoration offering are probably due to suppression of IL-1β. This study may be helpful in obtaining primary information for drug discovery to be effective against IL-1β and proving tear fluid as a novel diagnostic biomarker.

Antibacterial and anti-biofilm activities of gold-curcumin nanohybrids and its polydopamine form upon photo-sonotherapy of Staphylococcus aureus infected implants: In vitro and animal model studies

Implant-related infections are among the major post-surgery problems, and treatment of these infections is challenging due to the formation of biofilms by microorganisms such as Staphylococcus aureus. Herein, a novel gold-curcumin nanohybrid (GCNH) was synthesized for the first time and characterized. GCNH had a band gap energy of 2.41 eV, a zeta potential of −15 mV, and comprised uniform spherical particles with a mean diameter of 8 ± 2 nm. The biological macromolecule of polydopamine was then coated on GCNH to prepare a gold-curcumin-polydopamine nanohybrid (GCDNH). The nanohybrids were employed as novel dual photo-sonosensitizers for bacterial eradication by near-infrared (NIR) light and ultrasound (US) irradiations. GCNH and GCDNH represented photothermal conversion efficiencies of 26 and 32 %, respectively, and GCDNH represented a hemolysis rate of 2.3 % under both near-infrared (NIR) light and ultrasound (US) irradiations. NIR light and US irradiations (photo-sonotherapy) of Staphylococcus aureus using GCDNH depicted anti-bacterial and anti-biofilm efficiencies of 98 and 99 %, respectively, in synergistic manners, which are higher or as high as other sensitizers reported previously. The mechanism of photo-sonotherapy was related to generation of high levels of reactive oxygen species (ROS), and protein and nucleic acid leakages. In an in vivo infection model, NIR light and US irradiations annihilated Staphylococcus aureus on GCDNH-covered implants with high efficiency, without causing damage to normal tissues.

Antibacterial activity of Azanza garckeana extracts (Malvaceae) in vitro and their potential use in respiratory infections

The ESKAPE pathogens, namely Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species, pose a significant threat to individuals with compromised immune system, including children, people with underlying illnesses and patients primarily infected with viruses. Significant mortality rates have been documented as a consequence of severe pneumonia resulting from bacterial respiratory tract infections. Azanza garckeana has been reported to possess antibacterial and anti-inflammatory activities. This study aimed to determine the antibacterial activity of A. garckeana leaf and bark extracts against P. aeruginosa, K. pneumoniae, A. baumannii, and S. aureus. The broth microdilution method was used to evaluate antibacterial activity. The most active extracts were subjected to phytochemical analysis to identify types of bioactive compounds present using gas chromatograph mass spectrometry (GC‒MS). The effect of the extracts on the integrity of the bacterial membrane was performed using nucleic acid and protein leakage assay. Acetone bark extract was assessed for its potential antibiofilm activity using K. pneumoniae. The toxicity profiling of the most potent extracts was performed using sheep erythrocytes and mouse peritoneal cells. The hexane bark extract exhibited greater potency by inhibiting the growth of S. aureus and A. baumannii at a concentration of 200 μg/mL. GC-MS identified the presence of important bioactive compounds including, β-carotene, 9-hexadecen-1-ol, (Z)-, hexadecanoic acid, methyl ester, and 2,4-di-tert-butylphenol. Acetone bark extract exhibited antibacterial activity through disruption of bacterial membrane integrity, observed through significant nucleic acid and protein leakage. The acetone bark extract displayed promising antibiofilm activity against K. pneumoniae. Importantly, the extracts showed minimal toxicity, demonstrating less than 30 % haemolytic activity in sheep erythrocytes and were not toxic to the mouse peritoneal cells, instead boosting their growth. These findings suggest that A. garckeana may serve as a potential source of antibacterial lead agents for the management of respiratory infections.

Solid- and Vapor-Phase Antibacterial Activities and Mechanisms of Essential Oils Against Fish Spoilage Bacteria

Essential oils (EOs), regarded as secondary metabolites from plants, possess effective antibacterial properties. This study investigates the antibacterial efficacy of seven citrus EOs against six spoilage bacteria: Vibrio parahaemolyticus, V. harveyi, Photobacterium damselae, Shewanella putrefaciens, Carnobacterium divergens, and Lactobacillus pentosus. The antibacterial activity of these EOs was evaluated using solid- and vapor-phase applications. All tested EOs demonstrated effective antibacterial activity at a concentration of 294 μL/L against Gram-negative bacteria. Notably, lemon and orange EOs exhibited dose-dependent inhibition in both solid- and vapor-phase applications, with minimum effective concentrations ranging from 29.4 to 58.8 μL/L. Following treatment with lemon and orange EOs for 6 h at 1/4 minimum inhibitory concentration, leakage of intracellular DNA and proteins was observed, indicating damage to the cell membrane/wall. Proteomic analysis revealed distinct mechanisms: lemon EO impaired bacterial antioxidant defenses, while orange EO disrupted cell division, leading to reduced bacterial viability. These findings provide valuable insights into the potential of different EO application forms in controlling spoilage bacteria.

Curcuma longa rhizome extract: a potential antibiofilm agent against antibiotic-resistant foodborne pathogens

The traditional medicinal value of Curcuma longa (turmeric) and its potential relevance in modern healthcare suggests that traditional remedies and natural products can provide valuable solutions to contemporary challenges, such as combating biofilms and antibiotic-resistant pathogens, potentially offering new strategies for addressing health and safety issues in the fields of food and medicine. This study assessed the antibiofilm and antibacterial characterization of Curcuma longa rhizome extract against antibiotic-resistant foodborne pathogens. Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier-transform infrared (FTIR) analysis were determined to check for the compounds, functional groups, and constituents of the plant extract. In-vitro antibiofilm and antibacterial bioassay of the extract were determined using standard bacteriological procedures. Potential mechanisms of the plant extract were also studied using standard biological methods. The important chemical constituents from the GC-MS extract of C. longa are arturmerone, cinnamyl angelate, tumerone, γ-atlantone, atlantone, α-atlantone, γ-atlantone and curlone. The FTIR analysis of the extract comprises alkyl halides, bromoalkanes, alkanes, ethylene molecules, arenes, amines, alcohols, sulfones, carboxylic acids and their derivatives, aromatic compounds, and phenols. The MIC of C. longa crude extract ranges from ethanol extract (0.03125 − 0.5 mg/mL) and acetone extract (0.0625 − 0.5 mg/mL). The MBC range is as follows: ethanol extract (0.125 − 1 mg/mL), acetone extract (0.125 − 1 mg/mL). The time-kill kinetics showed significant cell reduction with time. The bacterial isolates’ nucleic acids and protein leakage were consistent with increased extract concentration and time. There was a reduction in the biofilm cell on the shrimp surface and EPS with increased concentration and time. C. longa exerted significant anti-biofilm activity by removing existing biofilms, disrupting cell connections, and decreasing cells in biofilms. These findings can aid food protection from microbial contamination and prevent biofilms-related infections.

Serum protein and imaging biomarkers after intermittent steroid treatment in muscular dystrophy

Weekly Steroids in Muscular Dystrophy (WSiMD) was a pilot study to evaluate once weekly prednisone in patients with Limb Girdle and Becker muscular dystrophy (LGMD and BMD, respectively). At study endpoint, there were trends towards increased lean mass, reduced fat mass, reduced creatine kinase and improved motor function. The investigation was motivated by studies in mouse muscular dystrophy models in which once weekly glucocorticoid exposure enhanced muscle strength and reduced fibrosis. WSiMD participants provided blood samples for aptamer serum profiling at baseline and after 6 months of weekly steroids. A subset completed magnetic resonance (MR) evaluation of muscle at study onset and endpoint. At baseline compared to age and sex-matched healthy controls, the aggregate serum protein profile in the WSiMD cohort was dominated by muscle proteins, reflecting leak of muscle proteins into serum. Disease status produced more proteins differentially present in serum compared to steroid-treatment effect. Nonetheless, a response to prednisone was discernable in the WSiMD cohort, even at this low dose. Glucocorticoids decreased muscle proteins and increased certain immune process- and matrix-associated proteins. Muscle MR fat fraction showed trends with functional status. The prednisone-responsive markers could be used in larger trial of prednisone efficacy.

Response mechanism of Saccharomyces cerevisiae under benzoic acid stress in ethanol fermentation

Sugarcane molasses is an ideal economical raw material for ethanol production because of its wide availability, low cost and nutrient content. However, benzoic acid compounds with toxic effects on yeast cells are commonly found in sugarcane molasses. At present, the molecular mechanism of the toxic effects of benzoic acid on Saccharomyces cerevisiae has not been elucidated. Here, the toxic effect of exogenous benzoic acid on S. cerevisiae GJ2008 cells was studied, and the genes differentially expressed in S. cerevisiae GJ2008 after 1.2 g/L benzoic acid stress were identified via Illumina RNA-Seq technology. The results indicated that benzoic acid significantly inhibited yeast cell growth, prolonged their rapid growth period, and ultimately reduced their biomass. During ethanol fermentation using 250 g/L sucrose under 1.2 g/L benzoic acid stress, several adverse effects were observed, such as high residual sugar content, low ethanol concentration and low fermentation efficiency. In addition, the cell morphology was damaged, the cell membrane permeability increased, intracellular nucleic acid and protein leakage increased, and the malondialdehyde content significantly increased. Moreover, the cells protected themselves by significantly increasing the intracellular glycerol content. Fourier transform infrared spectroscopy proved that benzoic acid could reduce the degree of unsaturation and increase cell membrane permeability by changing the yeast cell wall and cell membrane composition, leading to cell damage and even death. Transcriptomic analysis revealed that under benzoic acid stress, the expression of genes associated with sucrose and starch metabolism, thiamine metabolism, the glycolysis pathway, fructose and mannose metabolism, galactose metabolism and ABC transporters was significantly downregulated. The expression of genes related to ribosomes, lipid metabolism, ribosome biosynthesis, nucleic acid metabolism, arginine and proline metabolism, RNA polymerase, metabolism related to cofactor synthesis, and biosynthesis of valine, leucine, and isoleucine was significantly upregulated. These results indicated that benzoic acid inhibited glycolysis and reduced sugar absorption and utilization and ATP energy supply in yeast cells. In response to stress, genes related to the ribosome bioanabolic pathway were upregulated to promote protein synthesis. On the other hand, the expression of ELO1, SUR4, FEN1 and ERG1 was upregulated, which led to extension of long-chain fatty acids and accumulation of ergosterol to maintain cell membrane structure. In conclusion, this paper provides important insights into the mechanism underlying the toxicity of benzoic acid to yeast cells and for realizing high-concentration ethanol production by sugarcane molasses fermentation.

Molecular Mechanism: Inhibition of Fusarium oxysporum T-2 Toxin Synthesis by Surfactin in Dried Fish: Induction of Yap1 Nucleation by ROS Accumulation.

(1) T-2 toxin synthesized by Fusarium oxysporum (F. oxysporum) can cause deterioration of dried fish and endanger human health. (2) The molecular mechanism by which antibacterial lipopeptides surfactin inhibited F. oxysporum growth and toxin production was elucidated by investigating the intracellular ROS production pathway and the subcellular distribution and transcriptional activity of the transcription factor Yap1 and its regulation of Tri5 gene in F. oxysporum. (3) Surfactin caused hyphal damage and nucleic acid and protein leakage; thus, the growth of F. oxysporum was disrupted. Surfactin's excessive accumulation of intracellular ROS triggered the translocation of transcription factor Yap1 into the nucleus, resulting in toxin cluster gene Tri5 expression inhibition, thereby blocking T-2 toxin synthesis. (4) This is a novel mechanism by which surfactin inhibits the growth and T-2 toxin synthesis of F. oxysporum from multiple aspects, including cell structural integrity and the ROS-Yap1 signaling pathway. (5) This study provides a theoretical basis for the application of surfactin in the antifungal control of aquatic dry products.

Evaluation of Proteinuria in Diabetic Patients Attending Gitwe District Hospital

Background: Proteinuria is a serious condition in which body proteins leak into urine due to kidney dysfunction nearly always caused by elevated serum glucose due to prolonged diabetes. Proteinuria occurs and affects individuals with diabetes, approximately 25% of diabetic patients may have proteinuria. Aim: The aim of this study is to assess the levels of serum glucose and proteins in urine and their association in diabetic patients attending Gitwe District Hospital. Methodology: The study population mainly comprised of diabetic patients, 110 study participants were included. Blood was drawn from finger for testing serum glucose using glucometer and urine samples were collected from diabetic patients and samples were analyzed in parasitology service using urine chemistry strips for proteins in urine testing. Results: During data analysis, SPSS version 22 was used, the majority were female with 66.4% while 33.6% were male. The highest frequency of participants presented in this study were 27(24.6%) found in [43-52] years old. The mean age was 53 years ± 13.882 SD (ranged from 23 to 86 years). 53.7% had normal serum glucose level while 46.3% had high serum glucose level. However, 63.6% had no proteinuria while 20.0% had trace, 11.8% had mild and 4.6% had moderate proteinuria levels. Association between serum glucose and proteinuria was analyzed for statistical significance with Chi-square test and it was statistically significant as their p values were below 0.05(P-value of 0.000). Conclusion: The study found that high serum glucose level leads to the presence of proteins in the urine. This study recommends regular monitoring of serum glucose levels, as well as routine urine tests to detect proteinuria as essential components of diabetes management and other researchers to study the effects of proteinuria in diabetic patients. Keywords: Proteinuria, serum glucose, proteins, diabetic patients

Inhibitory Effect of DNase-Chitosan-Nisin Nanoparticles on Cell Viability, Motility, and Spatial Structures of Listeria monocytogenes Biofilms.

Listeria monocytogenes biofilm contamination on food contact surfaces is a major concern for the food industry. Nanoparticle encapsulation appears as a novel strategy for food surface disinfection to prevent biofilm formation. Chitosan nanoparticles loaded with nisin and DNase I (DNase-CS-N) have been constructed to exhibit antimicrobial activity against L. monocytogenes. This study aimed to investigate their ability to inhibit L. monocytogenes biofilm formation and eliminate preformed biofilms on food contact surfaces (polystyrene, polyurethane, and stainless steel). DNase-CS-N could decrease 99% and 99.5% biofilm cell numbers at 1/2 MIC and MIC, respectively. At sub-MICs, DNase-CS-N could reduce cell motility (swimming and swarming) and slime production of L. monocytogenes. In terms of effect on biofilm elimination, DNase-CS-N at the concentration of 4 MIC led to 3-4 log reduction in biofilm cells in preformed biofilms, performing higher efficiency compared with other treatments (CSNPs, CS-N). Furthermore, the three-dimensional structure of L. monocytogenes biofilms was severely disrupted after DNase-CS-N treatment, with bacterial cells scattered on the surface. The morphology of biofilm cells was also greatly damaged with wrinkled surfaces, disrupted cell membranes, and leakage of intracellular nucleic acids and proteins. These results indicate the potential applicability of DNase-CS-N for inhibiting and eliminating L. monocytogenes biofilms on food contact surfaces.

Synergistic antimicrobial effects of ammonium persulfate, ultrasound, and mild heat on Staphylococcus aureus under varied conditions

This study elucidated the antimicrobial effect of ammonium persulfate (PS), ultrasound (US), and 40–60 °C mild heat on Staphylococcus aureus ATCC 27213 under various growth conditions, including non-adaptation, pH-adaptation, and aridity-adaptation, in buffered peptone water (BPW) and on orange peel surfaces. For non-adapted, pH-adapted, and aridity-adapted S. aureus, the combined treatment of PS, US, and mild heat showed a synergistic effect, with log reductions of 2.05, 6.44, and 1.11 log CFU/mL in BPW after 6 min, respectively. Mechanistic experiments showed that pH-adapted S. aureus had increased SOD activity due to oxidative stress from the acidic environment, but the introduction of PS further elevated this stress, leading to greater cell death primarily through membrane damage, as confirmed by TEM, with leakage of nucleic acids and proteins. This technique was applied to an orange peel washing system, effectively inactivating aridity-adapted S. aureus, resulting in 3.51 log CFU/cm2 and 3.20 log CFU/mL reductions on orange peel and in BPW washing water, respectively, after a 6-min treatment, without any quality changes, including color and texture attributes. The enhanced inactivation on orange peel may be attributed to the presence of compounds such as ascorbic acid and limonene, which further activate persulfate and exhibit antimicrobial properties, thereby contributing to the increased efficacy of the treatment. The combined PS, US, and mild heat treatment provides an effective strategy for controlling resilient bacterial strains in the food industry, enhancing food safety through oxidative stress and mild thermal effects.

Activity of Bambara Groundnut Seed Coat Extract Against Shewanella Species: Efficacy and Mechanisms of Action.

The Bambara groundnut is the indigenous legume in the southern part of Thailand. It contains a seed coat rich in polyphenols, which can serve as natural antimicrobial agents. The extracts from red and white seed coats of Bambara groundnuts, namely RSC and WSC, respectively, were prepared using an ultrasound-assisted extraction process. The extraction yield, total phenolic content (TPC), and antimicrobial activity of both extracts were examined. The RSC extract demonstrated a significantly higher extraction yield (8.35%) than WSC extract (2.34%) (p < 0.05). Furthermore, the TPC of RSC extract (420.98 ± 0.27 mg of gallic acid/g dry extract) was higher than that of WSC extract (28.29 ± 0.91 mg of gallic acid/g dry extract). The RSC extract exhibited stronger inhibition against Shewanella putrefaciens and S. algae than its WSC counterpart. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) analysis indicated that the RSC extract was rich in flavonoids and polyphenols, while the WSC extract contained more triterpenoid saponins. Time-kill kinetics showed that the RSC extract reduced bacterial loads in a dose-dependent manner. Scanning electron microscopic images revealed that drastic bacterial cell membrane damage with a rough surface and the deformation of cells was caused by the extract. Furthermore, confocal laser scanning microscopic (CLSM) images confirmed the inhibition of S. algae biofilm formation by RSC extract. RSC extract also suppressed bacterial motility, induced protein leakage, and reduced extracellular protease activity, thus highlighting its potent bactericidal effects. These findings suggested that the RSC extract rich in phenolic compounds could serve as an antimicrobial agent and hold promise as a natural preservative for perishable foods, especially seafoods.

Inactivation and Mechanism of Alicyclobacillus acidoterrestris by Different Modes of High Hydrostatic Pressure, including Synergistic Effects with Essential Oils

High hydrostatic pressure (HHP) is widely used to inactivate microorganisms in food, but achieving effective spore inactivation by conventional HHP remains challenging due to their resistance. The present study compared the effectiveness of continuous, intermittent and induced inactivation HHP techniques for inactivation of Alicyclobacillus acidoterrestris spores. Under optimal induced inactivation conditions (200 MPa/4 cycles, 600 MPa/2 cycles), reductions of 0.79 log CFU/mL for the highly resistant DSM3922 spores and 1.94 log CFU/mL for the less resistant DSM3924 spores were achieved. Mechanistic investigations revealed that: (Ⅰ) structural damage, including breakage, wrinkling, and concavity, was induced in spores post-HHP treatment; (Ⅱ) pulsation forces generated by repeated pressurization and depressurization during induced inactivation HHP reduced the D90 values of the spore aggregates to 99.37 μm for DSM3922 and 76.49 μm for DSM3924, enhancing the inactivation efficacy; (Ⅲ) the inner membrane (IM) and cortex were severely impaired, while nucleic acid and protein leakage from spores significantly increased after HHPs. To further enhance spore inactivation, Tea Tree, Nutmeg, Eucalyptus, and Litsea cubeba essential oils (EOs) were selected from twelve EOs as safe and effective antimicrobial substances that synergize with HHP. Combining 5% Litsea cubeba EO with HHP (200 MPa/4 cycles, 600 MPa/2 cycles) resulted in reductions of 2.57 log CFU/mL for DSM3922 and 5.08 log CFU/mL for DSM3924. These findings suggest that the combination of HHP and EOs could be a promising approach for inactivating A. acidoterrestris spores.

Synergistic inactivation effect and mechanism of ultrasound combined with Zanthoxylum schinifolium essential oil nanoemulsions against Escherichia coli O157:H7 and its application on fresh-cut cucumber

Fresh-cut produce is often contaminated with Escherichia coli O157, posing a significant health risk. This study investigated the synergistic inactivation effect and underlying mechanism of ultrasound (US) combined with Zanthoxylum schinifolium essential oil nanoemulsion (ZEO-NE) against E. coli O157:H7, and explored its potential application in fresh-cut cucumbers. The results demonstrated that combined treatment of US and ZEO-NE significantly reduced the viable counts of E. coli O157:H7 compared to treatment with US or ZEO-NE alone. In particular, US (20 kHz, 345 W/cm2) + ZEO-NE (1.0 mg/mL) treatment for 12 min achieved an 8.91 log colony-forming units (CFU)/mL reduction in viable counts of E. coli O157:H7. Moreover, biofilm formation assay revealed that US+EO-NE treatment significantly reduced mobility, altered surface properties, and inhibited biofilm formation of E. coli O157:H7 cells compared to single treatments. The synergistic inactivation mechanism of US+ZEO-NE treatment against E. coli O157:H7 was revealed to involve increased cell membrane permeability, resulting in leakage of nucleic acids, proteins, and LDH, AKP, and ATP, disruption of cell membrane integrity, and alterations in membrane potential. Additionally, the US+ZEO-NE treatment induced reactive oxygen species accumulation and disrupted cell morphology, ultimately leading to E. coli O157:H7 cell death. Furthermore, the US+EO-NE treatment significantly reduced the E. coli O15:H7 counts in fresh-cut cucumbers compared to single treatments, without adversely affecting the quality and sensory properties of the produce during storage at 4 °C for 12 days. Overall, these findings suggest that US+EO-NE is a promising technique for bacterial inactivation, and holds potential for improving microbial safety in fresh-cut produce.

TFAM and Mitochondrial Protection in Diabetic Kidney Disease.

Diabetic kidney disease (DKD) is a significant complication of diabetes and a major cause of end-stage renal disease. Affecting around 40% of diabetic patients, DKD poses substantial economic burdens due to its prevalence worldwide. The primary clinical features of DKD include the leakage of proteins into the urine, altered glomerular filtration, and an increased risk of cardiovascular diseases. Current treatments focus on managing hypertension and hyperglycemia to slow the progression of DKD. These include the use of SGLT2 inhibitors to control blood sugar and ACE inhibitors to reduce blood pressure. Despite these measures, current treatments do not cure DKD and fail to address its underlying causes. Emerging research highlights mitochondrial dysfunction as a pivotal factor in DKD progression. The kidneys' high energy requirements make them particularly susceptible to disturbances in mitochondrial function. In DKD, mitochondrial damage leads to reduced energy production and increased oxidative stress, exacerbating tissue damage. Mitochondrial DNA (mtDNA) damage is a key aspect of this dysfunction, with studies suggesting that changes in mtDNA copy number can serve as biomarkers for the progression of the disease. Efforts to target mitochondrial dysfunction are gaining traction as a potential therapeutic strategy. This includes promoting mitochondrial health through pharmacological and lifestyle interventions aimed at enhancing mitochondrial function and reducing oxidative stress. Such approaches could lead to more effective treatments that directly address the DKD.

Microglial activation without peripheral immune cell infiltration characterises mouse and human cerebral small vessel disease.

Cerebral small vessel diseases (SVDs) involve diverse pathologies of the brain's small blood vessels, leading to cognitive deficits. Cerebral magnetic resonance imaging (MRI) reveals white matter hyperintensities (WMHs), lacunes, microbleeds and enlarged perivascular spaces in SVD patients. Although correlations of MRI and histopathology help to understand the pathogenesis of SVD, they do not explain disease progression. Mouse models, both genetic and sporadic, are valuable for studying SVD, but their resemblance to clinical SVD is unclear. The study examined similarities and differences between mouse models of SVDs and human nonamyloid SVD specimens. We analysed four mouse models of SVD (hypertensive BPH mice, Col4a1 mutants, Notch3 mutants and Htra1-/- mice) at different stages for changes in myelin, blood-brain barrier (BBB) markers, immune cell populations and immune activation. The observations from mouse models were compared with human SVD specimens from different regions, including the periventricular, frontal, central and occipital white matter. Postmortem MRI followed by MBP immunostaining was used to identify white matter lesions (WMLs). Only Notch3 mutant and hypertensive BPH mice showed significant changes in myelin basic protein (MBP) immunostaining, correlating with MRI patterns. These changes were linked to altered microglial morphology and focal plasma protein staining around blood vessels, without peripheral immune cell infiltration. In human specimens, both normal-appearing white matter (NAWM) and WMLs lacked peripheral cell infiltration. However, WMLs displayed altered microglial morphology, reduced myelin staining and occasional fibrinogen staining around arterioles and venules. Our data show that Notch3 mutants and hypertensive BPH/2J mice recapitulate several features of human SVD, including microglial activation, focal sites of demyelination and perivascular plasma protein leakage without peripheral immune cell infiltration.

Antimicrobial activity of ceftibuten/polymyxin B combination against polymyxin/carbapenem-resistant Klebsiella pneumoniae.

To evaluate the synergistic effect of a ceftibuten and polymyxin B combination and to determine its capacity to overcome polymyxin B resistance in polymyxin/carbapenem-resistant (PC-R) Klebsiella pneumoniae. To investigate the combination's antibacterial efficacy, antimicrobial susceptibility tests using broth microdilution methods, chequerboard assays and time-kill testing were performed. Antibiofilm activity was also assessed. The treatment's effect on the bacterial cell membrane was examined by quantifying intracellular protein leakage and conducting scanning electron microscopy. Haemocompatibility tests were conducted to evaluate toxicity. Additionally, an infection model was established using Swiss mice to assess in vivo antimicrobial activity. The ceftibuten/polymyxin B combination demonstrated synergistic effects against several PC-R strains of K. pneumoniae, as determined by the FIC index (FICI) values, which ranged from 0.15 to 0.37. This combination was efficacious, exhibiting bactericidal activity at twice the MIC. Ceftibuten/polymyxin B also demonstrated antibiofilm activity. Additionally, ceftibuten/polymyxin B neither damaged the bacterial membrane nor exhibited haemolytic activity. Based on these findings, the in vivo therapeutic potential was investigated and it was found that ceftibuten/polymyxin B significantly decreased the bacterial load in the peritoneal lavage fluid of mice, revealing its effectiveness in treating infections caused by PC-R K. pneumoniae. The ceftibuten/polymyxin B combination exhibited synergistic effects in vitro and in vivo, and thus might be a promising therapeutic alternative for treating PC-R K. pneumoniae infections. As the combination was efficacious in preclinical models, researchers may further investigate its potential in clinical studies.

Localization of albumin with correlative super resolution light- and electron microscopy in the kidney

The functioning of vertebrate life relies on renal filtration of surplus fluid and elimination of low-molecular-weight waste products, while keeping serum proteins in the blood. In disease, however, there is leak of serum proteins and tracing them to identify the leaking position within tissue with a nanometer resolution poses a significant challenge. Correlative microscopy integrates the specificity of fluorescent protein labeling into high-resolution electron micrographs. Using chemical tagging of albumin with synthetic fluorophores we achieve protein-specific labeling that preserve their post-embedding fluorescence after high-pressure freezing and freeze-substitution of murine kidney tissue. Using advanced registration techniques for super-resolution correlative light and electron microscopy, we can localize the labeled albumin with a high precision in the x-y plane of electron micrographs and cartograph its distribution. Thereby we can quantify the albumin concentration and measure a linear reduction gradient across the kidney filtration barrier. Our study shows the feasibility of combining different microscopy contrasts for tracing fluorescently labeled protein markers with super resolution in various tissue samples and opens new perspectives for correlative imaging in volume electron microscopy.

Highly Efficient AIE-Active palmatine photosensitizer for photodynamic inactivation of Listeria monocytogenes in apple juice preservation

Photodynamic sterilization is a promising alternative to conventional antibacterial approaches with merits of high efficiency and safety. The exploration of aggregation-induced emission (AIE)-type photosensitizers from natural sources is highly valued by researchers and food industry. Herein, the use of palmatine (PA), an aggregation-induced emission-active natural product from traditional Chinese medicine, as photosensitizers for photodynamic inactivation of a tenacious foodborne pathogen of Listeria monocytogenes is investigated. Antibacterial and antibiofilm activity against L. monocytogenes of PA-mediated photodynamic process were first assessed. The results showed that PA-mediated photodynamic process could inhibit the growth of L. monocytogenes, and the minimum bactericidal concentration was determined as 80 μM. At this PA dosing level, well-established biofilms of L. monocytogenes can be effectively destroyed under light irritation. Afterward, cell- and gene-level investigations were conducted to explore the antibacterial mechanism. It is concluded that the exceptional photodynamic antibacterial activity of PA against L. monocytogenes is attributed to the disruption of the cell wall and membrane, increased cell permeability, leakage of functional proteins, and damage to DNA structure. Subsequently, PA-mediated photodynamic process was applied to reduce bacterial activity in apple juice while preserving its quality. Overall, this work highlights the significant potential of PA-mediated photodynamic strategy for controlling foodborne pathogens in food systems.