Structural and tribological studies on the interaction of porcine gastric mucin with non- and cationic-modified ß-lactoglobulins.

ß-lactoglobulin (BLG) is the major whey protein with negative charges at neutral pH in aqueous media. Thus, the interaction with mucins, the major polyanionic component of mucus, is very weak due to the electrostatic repulsion between them. The present study postulates that cationization of BLG molecules may reverse the interaction characteristics between BLG and mucin from repulsive to associative. To this end, cationic-modified BLGs were prepared by grafting positively charged ethylenediamine (EDA) moieties into the negatively charged carboxyl groups on the aspartic and glutamic acid residues and compared with non-modified BLG upon mixing with porcine gastric mucin (PGM). To characterize the structural and conformational features of PGM, non/cationized BLGs, and their mixtures, various spectroscopic approaches, including zeta potential, dynamic light scattering (DLS), and circular dichroism (CD) spectroscopy were employed. Importantly, we have taken surface adsorption with optical waveguide lightmode spectroscopy (OWLS), and tribological properties with pin-on-disk tribometry at the sliding interface as the key approaches to determine the interaction nature between them as mixing PGM with polycations can lead to synergistic lubrication at the nonpolar substrate in neutral aqueous media as a result of an electrostatic association. All the spectroscopic studies and a substantial improvement in lubricity collectively supported a tenacious and associative interaction between PGM and cationized BLGs, but not between PGM and non-modified BLG. This study demonstrates a unique and successful approach to intensify the interaction between BLG and mucins, which is meaningful for a broad range of disciplines, including food science, macromolecular interactions, and biolubrication etc.

Relation of Streptococcus Pyogenes tonsillitis isolate to antimicrobial agents and its infection treatment.

We reported the case of tonsillitis treatment in a 17-years-old boy with use of chemical non-antibiotic preparations, plant derived products and antibiotic benzathine phenoxymethylpenicillin. The antimicrobial agents for treatment were selected on the basis of their activity against a disease agent, the group A ß-hemolytic strain Streptococcus pyogenes BS1 isolated from a patient. The bacterium was susceptible in vitro to ß-lactams, with largest zones conditioned by penicillin G and benzathine phenoxymethylpenicillin discs, to fluoroquinolones and to cephems, with exception of cefazolin. Lincosamide clindamycin, macrolide spiramycin, aminoglycoside gentamicin, erythromycin, tetracycline and combination of sulfamethoxazole and trimethoprim were inactive against this bacterium. The Streptococcus pyogenes BS1 demonstrated intermediate susceptibility to the cephalosporin cephalexin, fluoroquinolone lomefloxacin and glycopeptide vancomycin. Non-antibiotic preparations were evaluated against Streptococcus pyogenes BS1 also. Among them "Stomatidin", "Chlorophyllipt", and phages of "Pyofag" were more effective than "Decatylen", "Decasan" and "Furadonin" in vitro. The antimicrobial applications of "Stomatidin", "Chlorophyllipt" and phages of "Pyofag" in the patient were less effective compared to the result of antibiotic benzathine phenoxymethylpenicillin treatment. Complete recovery of the patient was achieved with use of this antibiotic and Calendula flower extract as an local anti-inflammatory agent.

Simple ammonium salt and sigma-1 receptor ligand dipentylammonium provides neuroprotective effects in cell culture and Caenorhabditis elegans models of Alzheimer's disease.

The sigma-1 receptor (σ-1R), a chaperone protein located at the mitochondria-associated membrane (MAM) of the endoplasmic reticulum, can interact with and modify the signaling pathways of various proteins, thereby modulating many disease pathologies, including Alzheimer's disease (AD). The σ-1R ligand dipentylammonium (DPA) was analyzed for its anti-AD properties using PC12 cells (in vitro) and Caenorhabditis elegans (in vivo) models along with molecular docking (in silico) analysis. DPA at 1 and 10 µM concentrations was able to significantly potentiate NGF-induced neurite growth length by 137.7 ± 12.0 and 187.8 ± 16.4, respectively, when compared to the control 76.9 ± 7.4. DPA also regulated neurite damage caused by Aß(25-35) treatment in differentiated PC12 cells by improving cell viability and neurite length. In C. elegans, DPA could significantly extend the median and maximum lifespan of Aß transgenic strain CL2006 without impacting wild-type nematodes. Additionally, it could significantly reduce the paralysis phenotype of another Aß transgenic strain, CL4176, thereby improving the overall health in AD pathogenesis. This effect depended on σ-1R, as DPA could not modulate the lifespan of σ-1R mutant TM3443. This was further confirmed using agonist PRE084 and antagonist BD1047, wherein the agonist alone could extend the lifespan of CL2006, while the antagonist suppressed the effect of DPA in CL2006. Interestingly, neither had an TM3443. Further, molecular docking analysis showed that DPA had a similar binding affinity as that of PRE084, BD1047 and pentazocine against the σ-1R receptor in humans and C. elegans, which collectively suggests the anti-AD properties of DPA.

Nontoxic Initiator Alternatives to TEMED for Redox Hydrogel Polymerization.

Polymeric hydrogels are versatile biomaterials, offering unique advantages in tunability and biocompatibility that make them well-suited to a range of applications. Cross-linking, a fundamental step in hydrogel fabrication, is often initiated using a toxic redox system, ammonium persulfate (APS), and tetramethylethylenediamine (TEMED), which hinders hydrogel utility in direct contact with cells (e.g., wound dressings). To overcome this limitation, we developed alternative redox gelation systems that serve as nontoxic replacements for TEMED. The alternate initiators were either synthetic or bioinspired amine-containing polymers, Glycofect and polyethylenimine (PEI). Used with APS, these initiator candidates produced hydrogels with short gelation time and comparable moduli to TEMED-based gels and underwent further mechanical testing and biocompatibility characterization. While achieving mechanical properties similar to those of the control, the gels based on Glycofect and PEI outperformed TEMED-based gels in two cell viability studies, with Glycofect-initiated gels displaying significantly higher cytocompatibility. Taken together, these results indicate that Glycofect may serve as a drop-in replacement for TEMED to fabricate hydrogels with improved biocompatibility.

[Effect of EDDS Application on Soil Cu/Cd Availability and Uptake/transport by Castor].

To investigate the effect of chelating agents on plant uptake of heavy metals, castor (Ricinus communis L.) was used as the test plant. Soil culture and pot experiments were conducted to study the effects of different concentrations of ethylenediamine disuccinic acid (EDDS) on the forms of Cu and Cd in soil and their absorption and transport by castor. The results showed that the application of EDDS significantly increased the content of available Cu and Cd. After 15 days of cultivation, the available Cu and Cd concentrations in the soil increased by 43.01%-103.55% and 51.78%-69.43%, respectively. EDDS promoted the conversion of reducible Cu to weak acid extractable and increased the mobility of Cu. Meanwhile, the application of EDDS promoted the absorption, transport, and enrichment of Cu in castor. Under the application of 2.5 mmol·kg-1 EDDS and 5.0 mmol·kg-1 EDDS, the Cu concentrations in the shoots were 4.88 times and 16.65 times higher than that of the control (P< 0.05), and the Cu concentrations in the roots were 2.89 times and 3.60 times higher than that of the control (P< 0.05), respectively. The Cu transport coefficient significantly increased by 72.73% and 381.82% when treated with EDDS 2.5 and EDDS 5.0. Simultaneously, the phytoextraction of Cu in shoots, roots, and their sum were 14.08, 2.16, and 4.70 times higher than that of the control (P<0.05), respectively, when treated with EDDS 5.0. Furthermore, EDDS significantly increased the Cd concentrations in castor. When treated with EDDS 2.5 the shoots and roots increased by 15.15% and 57.42%, respectively, and the phytoextraction of total Cd significantly increased by 13.44%. Generally, the EDDS treatment could increase the available Cu and Cd in soil, promote the uptake of Cu and Cd, and improve the phytoremediation efficiency of castor. Among them, the addition of 5.0 mmol·kg-1 EDDS had the best effect for Cu, whereas the addition of 2.5 mmol kg-1 EDDS had a higher increase in the phytoextraction of Cd.

Amination and crosslinking of acetone-fractionated hardwood kraft lignin using different amines and aldehydes for sustainable bio-based wood adhesives.

Hardwood kraft lignin from the pulping industry is burned or discarded. Its valorization was conducted by subjecting fractionation, amination with ethylenediamine, diethylenetriamine, and monoethanolamine, and crosslinking with formaldehyde or glyoxal to obtain bio-based wood adhesives. Acetone-soluble and insoluble hardwood kraft lignin were prepared and subjected to amination and then crosslinking. Fourier transform infrared, 13C NMR, 15N NMR, and X-ray photoelectron spectroscopy results revealed successful amination with amide, imine, and ether bonds and crosslinking of all samples. Hardwood kraft lignin aminated with diethylenetriamine/ethylenediamine and crosslinked using glyoxal exhibited excellent results in comparison with samples crosslinked using formaldehyde. Acetone-insoluble hardwood kraft lignin aminated and crosslinked using diethylenetriamine and formaldehyde, respectively, exhibited excellent adhesion strength with plywood, satisfying the requirements of the Korean standards. The amination and crosslinking of industrial waste hardwood kraft lignin constitute a beneficial valorization method.

Zinc as a potential regulator of the BCR-ABL oncogene in chronic myelocytic leukemia cells.

BACKGROUND: Generally, decreased zinc in the serum of tumor patients but increased zinc in tumor cells can be observed. However, the role of zinc homeostasis in myeloid leukemia remains elusive. BCR-ABL is essential for the initiation, maintenance, and progression of chronic myelocytic leukemia (CML). We are currently investigating the association between zinc homeostasis and CML. METHODS: Genes involved in zinc homeostasis were examined using three GEO datasets. Western blotting and qPCR were used to investigate the effects of zinc depletion on BCR-ABL expression. Furthermore, the effect of TPEN on BCR-ABL promoter activity was determined using the dual-luciferase reporter assay. MRNA stability and protein stability of BCR-ABL were assessed using actinomycin D and cycloheximide. RESULTS: Transcriptome data mining revealed that zinc homeostasis-related genes were associated with CML progression and drug resistance. Several zinc homeostasis genes were affected by TPEN. Additionally, we found that zinc depletion by TPEN decreased BCR-ABL mRNA stability and transcriptional activity in K562 CML cells. Zinc supplementation and sodium nitroprusside treatment reversed BCR-ABL downregulation by TPEN, suggesting zinc- and nitric oxide-dependent mechanisms. CONCLUSION: Our in vitro findings may help to understand the role of zinc homeostasis in BCR-ABL regulation and thus highlight the importance of zinc homeostasis in CML.

Study of the antibacterial and cytotoxic activity of chitosan and its derivatives chemically modified with phthalic anhydride and ethylenediamine.

The insertion of hydrophobic and hydrophilic chains in the chitosan molecule can improve its antibacterial activity, expanding its range of application in several areas of medical-pharmaceutical sciences. Thus, this work aimed to increase the antibacterial activity of chitosan through the modification reaction with phthalic anhydride (QF) and subsequent reaction with ethylenediamine (QFE). The chitosan and derivatives obtained were characterized by elemental analysis, 13C Nuclear Magnetic Resonance (13C NMR), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TG), where it was possible to prove the chemical modification. Both materials showed a greater antibacterial inhibitory effect against Gram-positive bacteria, Staphylococcus aureus, emphasizing antibacterial activity against Gram-negative bacteria, Escherichia coli, with values above 70 % of the inhibitory effect, which is a promising result. Assays with human fibroblast cells by the [3-(4,5-dimethylthiazolyl)-2,5-diphenyl tetrazolium (MTT)] bromide reduction test did not indicate toxicity in the materials. Thus, the derived materials showed promise for biomedical applications since they combined excellent antibacterial activity against gram-positive and gram-negative strains and did not show cytotoxicity.

Computational Analysis of the Superoxide Dismutase Mimicry Exhibited by a Zinc(II) Complex with a Redox-Active Organic Ligand.

Previously, we found that a Zn(II) complex with the redox-active ligand N-(2,5-dihydroxybenzyl)-N,N',N'-tris(2-pyridinylmethyl)-1,2-ethanediamine (H2qp1) was able to act as a functional mimic of superoxide dismutase, despite its lack of a redox-active transition metal. As the complex catalyzes the dismutation of superoxide to form O2 and H2O2, the quinol in the ligand is believed to cycle between three oxidation states: quinol, quinoxyl radical, and para-quinone. Although the metal is not the redox partner, it nonetheless is essential to the reactivity since the free ligand by itself is inactive as a catalyst. In the present work, we primarily use calculations to probe the mechanism. The calculations support the inner-sphere decomposition of superoxide, suggest that the quinol/quinoxyl radical couple accounts for most of the catalysis, and elucidate the many roles that proton transfer between the zinc complexes and buffer has in the reactivity. Acid/base reactions involving the nonmetal-coordinating hydroxyl group on the quinol are predicted to be key to lowering the energy of the intermediates. We prepared a Zn(II) complex with N-(2-hydroxybenzyl)-N,N',N'-tris(2-pyridinylmethyl)-1,2-ethanediamine (Hpp1) that lacks this functional group and found that it could not catalyze the dismutation of superoxide; this confirms the importance of the second, distal hydroxyl group of the quinol.

Analytical determination of ethylenediamine impurity in tripelennamine hydrochloride by gas chromatography-mass spectrometry using phthalaldehyde as the derivatizing agent.

In the pharmaceutical industry, effective risk management and control strategies for potential genotoxic impurities are of paramount importance. The current study utilized GC-MS to evaluate a precise, linear, and accurate analytical method for quantifying ethylenediamine present in tripelennamine hydrochloride using phthalaldehyde as a derivatizing agent. When phthalaldehyde is sonicated for 10 min at room temperature, it reacts with ethylenediamine to form (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine. This approach minimizes matrix interference issues and resolves sample preparation difficulties encountered during ethylenediamine identification in GC-MS. In this method, helium serves as the carrier gas, while methanol acts as the diluent. The stationary phase consists of a DB-5MS column (30 m × 0.25 mm × 0.25 µm) with a flow rate of 1.5 mL/min. The retention time of (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine was determined to be 6.215 min. The method validation demonstrated limits of detection and quantification for (1z,5z)-3,4-dihydrobenzo[f][1,4]diazocine at 0.4 and 1.0 ppm, respectively, with a linearity range spanning from 1 to 30 ppm concentration with respect to the specification level. System suitability, precision, linearity, and accuracy of the current method were assessed in accordance with guidelines, yielding results deemed suitable for the intended use.

S288T mutation altering MmpL3 periplasmic domain channel and H-bond network: a novel dual drug resistance mechanism.

CONTEXT: Mycobacterial membrane proteins Large 3 (MmpL3) is responsible for the transport of mycobacterial acids out of cell membrane to form cell wall, which is essential for the survival of Mycobacterium tuberculosis (Mtb) and has become a potent anti-tuberculosis target. SQ109 is an ethambutol (EMB) analogue, as a novel anti-tuberculosis drug, can effectively inhibit MmpL3, and has completed phase 2b-3 clinical trials. Drug resistance has always been the bottleneck problem in clinical treatment of tuberculosis. The S288T mutant of MmpL3 shows significant resistance to the inhibitor SQ109, while the specific action mechanism remains unclear. The results show that MmpL3 S288T mutation causes local conformational change with little effect on the global structure. With MmpL3 bound by SQ109 inhibitor, the distance between D710 and R715 increases resulting in H-bond destruction, but their interactions and proton transfer function are still restored. In addition, the rotation of Y44 in the S288T mutant leads to an obvious bend in the periplasmic domain channel and an increased number of contact residues, reducing substrate transport efficiency. This work not only provides a possible dual drug resistance mechanism of MmpL3 S288T mutant but also aids the development of novel anti-tuberculosis inhibitors. METHODS: In this work, molecular dynamics (MD) and quantum mechanics (QM) simulations both were performed to compare inhibitor (i.e., SQ109) recognition, motion characteristics, and H-bond energy change of MmpL3 after S288T mutation. In addition, the WT_SQ109 complex structure was obtained by molecular docking program (Autodock 4.2); Molecular Mechanics/ Poisson Boltzmann Surface Area (MM-PBSA) and Solvated Interaction Energy (SIE) methods were used to calculate the binding free energies (∆Gbind); Geometric criteria were used to analyze the changes of hydrogen bond networks.

Simple acute postero-lateral elbow dislocation: A historical perspective.

PURPOSE: The aims of this study were to summarize (1) the historical knowledge of the posterolateral elbow dislocation (PLED) pattern and the biomechanical, radiographic, and clinical data that engendered its evolution; and (2) to help clinicians better understand the management of PLED. METHODS: A literature search was performed using Ovid, Scopus and Cochrane Library, and the Medical Subject Headings vocabulary. Results are discussed as a chronologic review of the relevant literature between 1920-2022. RESULTS: In 1966 Osborn and Cotterill were the first to describe posterolateral rotatory instability (PLRI) causing the PLED. Several theories on PLED were then published by others surgeons as our understanding of elbow biomechanics continued to improve. Multiple treatment protocols have been designed based on the aforementioned theories. Conservative and surgical treatment for PLED provides excellent functional outcomes. However, high rates of persistent pain stiffness and instability have been reported long-term, and no single approach to treatment has been widely accepted. CONCLUSION: Despite a growing body of biomechanical evidence, there is no consensus surgical indication for the treatment of PLED. Both conservative and surgical management result in satisfactory functional outcomes after PLED. However, elevated rates of residual pain, and instability have also been described and may limit heavy labor and sports participation. The next challenge for elbow surgeons will be to identify those patients who would benefit from surgical stabilization following PLED.

Monomeric copper(II) complexes with unsymmetrical salen environment: Synthesis, characterization and study of biological activities.

Three new ONNO-donor tetradentate unsymmetrical salen ligands were synthesized by using o-phenyl diamine with substituted salicylaldehydes followed by a two-step reaction methodology. These three ligands by reaction with Cu(OAc)2.4H2O produced three new monomeric Cu(II) complexes, [CuII(L1-3)] (1-3). Elemental analysis, IR, UV-vis, NMR, and HR-ESI-MS techniques were used to analyze and characterize all the synthesized ligands and their corresponding metal complexes. Molecular structures of 1-3 were confirmed by the single-crystal-XRD analysis. Furthermore, the DNA binding ability of these complexes was checked through UV-vis, fluorescence spectroscopy, and also by circular dichroism studies. All the complexes were found to show an intercalation mode of binding with the Kb value in the range of 104-105 M-1. Finally, 1-3 was tested against two malignant (HeLa and A549) and non-cancerous (NIH-3T3) cell lines to check their in vitro antiproliferative activities. Among all, 1 is the most cytotoxic of the series having IC50 values of 5.7 ± 0.9 and 6.0 ± 0.3 µM against HeLa and A549 cell lines, respectively. This result is also consistent with the DNA binding order. Furthermore, the apoptotic mode of cell death of all the complexes was also evaluated by DAPI, AO/EB, and Annexin V-FITC/PI double staining assays.

"Covalent-Disassembly"-Based Approaches For Sensing Applications.

The detection of analytes with small molecular probes is crucial for the analysis and understanding of chemical, medicinal, environmental and biological situations as well as processes. Classic detection approaches rely on the concept of molecular recognition and bond formation reactions. Bond breakage reactions have been less explored in similar contexts. This concept article introduces metal-salen and metal-imine complexes as "covalent-disassembly"-based (DB)-probes for detecting polyoxophosphates, thiols, amino acids, HCN and changes in pH. It discusses the roles, importance and combinations of structurally functionalized molecular building blocks in the construction of DB-probes. Applications of optimized DB-probes for analyte detection in live cells and foodstuff are also discussed. Furthermore, the mechanism of the disassembly of a Fe(III)-salen probe upon pyrophosphate binding is presented. Extraordinary selectivity for this analyte was achieved by a multistep disassembly sequence including an unprecedented structural change of the metal complex (i. e. "induced-fit" principle). Design principles of probes for sensing applications following the "covalent-disassembly" approach are summarized, which will help improving current systems, but will also facilitate the development of new DB-probes for challenging analytic targets.

Cytosolic zinc mediates the cytotoxicity of thiol-reactive electrophiles in rat vascular smooth muscle cells.

The aberrant increase or dysregulation of cytosolic Zn2+ concentration ([Zn2+]cyt) has been associated with cellular dysfunction and cytotoxicity. In this study, we postulated that Zn2+ mediates the cytotoxicity of thiol-reactive electrophiles. This notion was grounded on earlier research, which revealed that thiol-reactive electrophiles may disrupt Zn2+-binding motifs, consequently causing Zn2+ to be released from Zn2+-binding proteins, and leading to a surge in [Zn2+]cyt. The thiol-reactive electrophiles N-ethylmaleimide (NEM) and diamide were observed to induce an increase in [Zn2+]cyt, possibly through the impairment of Zn2+-binding motifs, and subsequent stimulation of reactive oxygen species (ROS) formation, resulting in cytotoxicity in primary cultured rat vascular smooth muscle cells. These processes were negated by the thiol donor N-acetyl-L-cysteine and the Zn2+ chelator TPEN. Similar outcomes were detected with co-treatment involving Zn2+ and Zn2+ ionophores such as pyrithione or disulfiram. Moreover, TPEN was found to inhibit cytotoxicity triggered by short-term exposure to various thiol-reactive electrophiles including hydrogen peroxide, acrylamide, acrylonitrile, diethyl maleate, iodoacetic acid, and iodoacetamide. In conclusion, our findings suggest that cytosolic Zn2+ acts as a universal mediator in the cytotoxic effects produced by thiol-reactive electrophiles.

Sensitization to ethylenediamine dihydrochloride in patients with contact dermatitis in northeastern Italy from 1996 to 2021.

BACKGROUND: Ethylenediamine dihydrochloride is a versatile aliphatic amine found in numerous medications and industrial compounds and is a known sensitiser. The sensitization prevalence is affected by geographical and socio-cultural factors. OBJECTIVES: The objectives are to analyse the temporal trend of sensitization to ethylenediamine dihydrochloride in northeastern Italy and to investigate associations with occupations. METHODS: Between 1996 and 2021, 30 629 patients with suspected allergic contact dermatitis were patch tested with the Triveneto baseline series. Individual characteristics were collected through a standardised questionnaire. RESULTS: The overall prevalence of ethylenediamine dihydrochloride sensitization was 1.29% with percentages similar in both sexes. We observed a significant decreasing trend over time (p < 0.001), yielding a sensitization prevalence <1% in recent years. Among departments, residence in Pordenone area was protective for sensitization. No significant associations were observed with specific occupations. We found significant associations between ethylenediamine dihydrochloride sensitization and being 26-35 years old (odds ratio [OR], 1.47; 95% confidence interval [CI]: 1.05-2.08), and sensitization for many haptens, such as paraben mix (OR, 5.3; 95% CI: 3.3-8.5), epoxy resin (OR, 5.1; 95% CI: 3.0-8.7), neomycin sulphate and mercaptobenzothiazole. CONCLUSIONS: Our study showed a downward time trend of ethylenediamine dihydrochloride sensitization in northeastern Italian population and pointed to an update of the Triveneto baseline series.

Physiological Responses and Performance of Simulated High-Rise Firefighting.

OBJECTIVE: The aim of the study is to determine the physiological effects of breathing apparatus and ascent strategies during a simulated 120-m vertical high-rise firefighting ascent. METHODS: Twenty-eight firefighters completed four high-rise firefighting trials wearing standard- or extended-duration breathing apparatus with continuous ascent (SDBA-C/EDBA-C) or with breaks (SDBA-B/EDBA-B). Task time, heart rate, ratings of perceived exertion, core body temperature, and thermal comfort were recorded at predetermined elevations. RESULTS: Task time took significantly longer during the EDBA-C compared with SDBA-C trial. Heart rate (at 40, 80, and 100 m) was significantly lower in trials following breaks compared with the continuous trials. Core body temperature rose by 0.11°C every 10 m of ascent. During the SDBA trials, 89% to 96% of firefighters activated their low air alarm compared with only 7% in EDBA. CONCLUSIONS: Firefighters should wear EDBA beyond 80 m of ascent and are encouraged to take regular breaks.

Resveratrol Inhibits Zinc Deficiency-Induced Mitophagy and Exerts Cardiac Cytoprotective Effects.

Resveratrol (Res) possesses various beneficial effects, including cardioprotective, anti-inflammatory, anti-aging, and antioxidant properties. However, the precise mechanism underlying these effects remains unclear. Here we investigated the protective effects of resveratrol on cardiomyocytes, focusing on the role of Zn2+ and mitophagy. Using the MTT/lactate dehydrogenase assay, we found that addition of a zinc chelator TPEN for 4 h induced mitophagy and resulted in a significant reduction in cell viability, increased cytotoxicity, and apoptosis in H9c2 cells. Notably, resveratrol effectively mitigated these detrimental effects caused by TPEN. Similarly, Res inhibited the TPEN-induced expression of mitophagy-associated proteins, namely P62, LC3, NIX, TOM20, PINK1, and Parkin. The inhibitory action of resveratrol on mitophagy was abrogated by the mitophagy inhibitor 3-MA. Additionally, we discovered that silencing of the Mfn2 gene could reverse the inhibitory effects of resveratrol on mitophagy via the AMPK-Mfn2 axis, thereby preventing the opening of the mitochondrial permeability transition pore (mPTP). Collectively, our data suggest that Res can safeguard mitochondria protection by impeding mitophagy and averting mPTP opening through the AMPK-Mfn2 axis in myocardial cells.

The dyeing effect of acridine orange for multiple plasmid systems is sensitive to temperature.

The Goldview dyeing of the natural multiplasmid system of Lactobacillus plantarum PC518 was affected by temperature. The article want to identify the specific molecules that cause temperature sensitivity, then experiment on the universality of temperature sensitivity, and finally preliminarily analyze the influencing factors. At 5°C and 25°C, single pDNA, multiplasmid system, and linear DNA samples were electrophoretic on agarose gel prestained by Goldview 1, 2, 3, and acridine orange (AO), respectively. Eighteen vectors of Escherichia coli and two vectors shortened by cloning were mixed into multiplasmid systems with different member numbers, and then electrophoresis with AO staining was performed within the range of 5°C-45°C, with a linearized multiplasmid system as the control. The lane profiles (peaks) were captured with Image Lab 5.1 software. After electrophoresis, the nine-plasmid-2 system was dyed with AO solutions of different ionic strengths to detect the effect of ionic strength on temperature sensitivity. It was measured that the UV-visible absorption spectra of the nine-plasmid-2 system dissolved in AO solutions with different ionic strengths and pH. Further, a response surface model was constructed using Design-Expert.V8.0.6 software. The electrophoresis result showed that the multiplasmid system from L. plantarum PC518 stained by AO staining showed a weak band at 5°C and five bands at 25°C, which was similar to the result of staining with Goldview 1, 2, and 3. The synthetic nine-plasmid-1 system and nine-plasmid-2 system displayed different band numbers on the electrophoresis gel in the electrophoresis temperature range of 5°C-45°C, namely 3, 4, 6, 4, and 2 bands, as well as 2, 6, 7, 8, and 5 bands. Using the 1× Tris-acetate-EDTA (TAE)-AO solution, the poststaining results of the nine-plasmid-2 system in the temperature range of 5°C-45°C were 4, 6, 9, 9, and 7 bands, respectively. Further, using 5×, 10×, or 25× TAE buffer, the AO poststaining results at 5°C were 4, 2, and 1 bands, respectively. The ultraviolet spectral results from 5°C to 25°C showed that there was a significant difference (3.5 times) in the fluctuation amplitude at the absorption peak of 261.2 nm between 0× and 1-10× TAE-AO solution containing the nine-plasmid-2 system. Specifically, the fluctuation amplitudes of 0×, 1×, 5×, and 10× samples were 0.032, 0.109, 0.112, and 0.110, respectively. At the same time, using 1× and 10× TAE buffer, the AO-stained linear nine-plasmid-2 system remained stable and did not display temperature sensitivity. The response surface models of the AO-stained nine-plasmid-2 system intuitively displayed that the absorbance of the 1× TAE samples increased significantly with increasing temperature compared to the 0× TAE samples, regardless of the pH value. The findings confirmed a temperature-dependent effect in AO staining of natural or synthetic multiplasmid systems, with the optimum staining result occurring at 25°C. Ion strength was a necessary condition for the temperature sensitivity mechanism. This study layed the groundwork for further investigation into the reasons or underlying mechanisms of temperature sensitivity in AO staining of multiplasmid systems.

Synthesis, characterization and discovery of multiple anticancer mechanisms of dibutyltin complexes based on salen-like ligands.

A series of novel dibutyltin complexes based on salen-like ligands (S01-S03) were synthesized and characterized using ultraviolet-visible spectra，infrared spectra, 1H, 13C, and 119Sn nuclear magnetic resonance, high-resolution mass spectrometry, X-ray crystallography, and thermogravimetric analysis. Complex S03 had excellent anticancer activity in vitro (IC50 = 1.5 ± 0.2 µM in CAL-27 cell lines), which highly activated ROS expression levels and induced apoptosis and cell cycle arrest at the G2/M phase. Interestingly, complex S03 induced cancer cell death through multiple mechanisms (mitochondrial pathway, ER-stress pathway, and DNA damage pathway). This study reveals new mechanisms of organotin complexes and provides new insights into the development of organotin metal complexes as anticancer drugs in the future, and compounds with multiple anticancer mechanisms may be a new strategy for delaying or overcoming drug resistance to chemotherapy and target therapy.