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Xenobiotica; the Fate of Foreign... Jun 2024We aimed to elucidate the toxic effects and biological activities of 3-phenoxybenzoic acid (3PBA) and its metabolite products. Numerous methods were used to identify...
We aimed to elucidate the toxic effects and biological activities of 3-phenoxybenzoic acid (3PBA) and its metabolite products. Numerous methods were used to identify the toxic effects and biological activities of 3PBA, including PASS online, molecular docking, ADMETlab 2.0, ADMESWISS, MetaTox, and molecular dynamic simulation. Ten metabolite products were identified via Phase II reactions (O-glucuronidation, O-sulfation, and methylation). All of the investigated compounds were followed by Lipinski's rule, indicating that they were stimulants or inducers of hazardous processes. Because of their high gastrointestinal absorption and ability to reach the blood-brain barrier, the studied compounds' physicochemical and pharmacokinetic properties matched existing evidence of harmful effects, including haematemesis, reproductive dysfunction, allergic dermatitis, toxic respiration, and neurotoxicity. The studied compounds have been linked to the apoptotic pathway, the reproductivity system, neuroendocrine disruptors, phospholipid-translocating ATPase inhibitors, and JAK2 expression. An O-glucuronidation metabolite product demonstrated higher binding affinity and interaction with CYP2C9, CYP3A4, caspase 3, and caspase 8 than 3PBA and other metabolite products, whereas metabolite products from methylation were predominant and more toxic. Our in silico findings partly meet the 3Rs principle by minimizing animal testing before more study is needed to identify the detrimental effects of 3PBA on other organs (liver, kidneys). Future research directions may involve experimental validation of predictions, elucidation of molecular mechanisms, and exploration of therapeutic interventions. These findings contribute to our understanding of the toxicological profile of 3PBA and its metabolites, which has implications for risk assessment and regulatory decisions.
PubMed: 38833509
DOI: 10.1080/00498254.2024.2361457 -
Planta Jun 2024A callus-specific CRISPR/Cas9 (CSC) system with Cas9 gene driven by the promoters of ZmCTA1 and ZmPLTP reduces somatic mutations and improves the production of heritable...
A callus-specific CRISPR/Cas9 (CSC) system with Cas9 gene driven by the promoters of ZmCTA1 and ZmPLTP reduces somatic mutations and improves the production of heritable mutations in maize. The CRISPR/Cas9 system, due to its editing accuracy, provides an excellent tool for crop genetic breeding. Nevertheless, the traditional design utilizing CRISPR/Cas9 with ubiquitous expression leads to an abundance of somatic mutations, thereby complicating the detection of heritable mutations. We constructed a callus-specific CRISPR/Cas9 (CSC) system using callus-specific promoters of maize Chitinase A1 and Phospholipid transferase protein (pZmCTA1 and pZmPLTP) to drive Cas9 expression, and the target gene chosen for this study was the bZIP transcription factor Opaque2 (O2). The CRISPR/Cas9 system driven by the maize Ubiquitin promoter (pZmUbi) was employed as a comparative control. Editing efficiency analysis based on high-throughput tracking of mutations (Hi-TOM) showed that the CSC systems generated more target gene mutations than the ubiquitously expressed CRISPR/Cas9 (UC) system in calli. Transgenic plants were generated for the CSC and UC systems. We found that the CSC systems generated fewer target gene mutations than the UC system in the T0 seedlings but reduced the influence of somatic mutations. Nearly 100% of mutations in the T1 generation generated by the CSC systems were derived from the T0 plants. Only 6.3-16.7% of T1 mutations generated by the UC system were from the T0 generation. Our results demonstrated that the CSC system consistently produced more stable, heritable mutants in the subsequent generation, suggesting its potential application across various crops to facilitate the genetic breeding of desired mutations.
Topics: Zea mays; CRISPR-Cas Systems; Plants, Genetically Modified; Mutation; Gene Editing; Promoter Regions, Genetic; Plant Proteins; Transcription Factors; Basic-Leucine Zipper Transcription Factors; DNA-Binding Proteins
PubMed: 38833022
DOI: 10.1007/s00425-024-04451-w -
BioRxiv : the Preprint Server For... May 2024Cardiolipin (CL) is a mitochondria-specific phospholipid that forms heterotypic interactions with membrane-shaping proteins and regulates the dynamic remodeling and...
Cardiolipin (CL) is a mitochondria-specific phospholipid that forms heterotypic interactions with membrane-shaping proteins and regulates the dynamic remodeling and function of mitochondria. However, the precise mechanisms through which CL influences mitochondrial morphology are not well understood. In this study, employing molecular dynamics (MD) simulations, we observed CL localize near the membrane-binding sites of the mitochondrial fusion protein Optic Atrophy 1 (OPA1). To validate these findings experimentally, we developed a bromine-labeled CL probe to enhance cryoEM contrast and characterize the structure of OPA1 assemblies bound to the CL-brominated lipid bilayers. Our images provide direct evidence of interactions between CL and two conserved motifs within the paddle domain (PD) of OPA1, which control membrane-shaping mechanisms. We further observed a decrease in membrane remodeling activity for OPA1 in lipid compositions with increasing concentrations of monolyso-cardiolipin (MLCL). Suggesting that the partial replacement of CL by MLCL accumulation, as observed in Barth syndrome-associated mutations of the tafazzin phospholipid transacylase, compromises the stability of protein-membrane interactions. Our analyses provide insights into how biological membranes regulate the mechanisms governing mitochondrial homeostasis.
PubMed: 38826344
DOI: 10.1101/2024.05.21.595226 -
BioRxiv : the Preprint Server For... May 2024Our ability to hear and maintain balance relies on the proper functioning of inner ear sensory hair cells, which translate mechanical stimuli into electrical signals via...
Our ability to hear and maintain balance relies on the proper functioning of inner ear sensory hair cells, which translate mechanical stimuli into electrical signals via mechano-electrical transducer (MET) channels, composed of TMC1/2 proteins. However, the therapeutic use of ototoxic drugs, such as aminoglycosides and cisplatin, which can enter hair cells through MET channels, often leads to profound auditory and vestibular dysfunction. Despite extensive research on otoprotective compounds targeting MET channels, our understanding of how small molecule modulators interact with these channels remains limited, hampering the discovery of novel compounds. Here, we propose a structure-based screening approach, integrating 3D-pharmacophore modeling, molecular simulations, and experimental validation. Our pipeline successfully identified several novel compounds and FDA-approved drugs that reduced dye uptake in cultured cochlear explants, indicating MET modulation activity. Molecular docking and free-energy estimations for binding allowed us to identify three potential drug binding sites within the channel pore, phospholipids, and key amino acids involved in modulator interactions. We also identified shared ligand-binding features between TMC and structurally related TMEM16 protein families, providing novel insights into their distinct inhibition, while potentially guiding the rational design of MET-channel-specific modulators. Our pipeline offers a broad application to discover small molecule modulators for a wide spectrum of mechanosensitive ion channels.
PubMed: 38826329
DOI: 10.1101/2024.03.05.583611 -
Biomedicine & Pharmacotherapy =... Jul 2024Globally, infections due to multi-drug resistant (MDR) Gram-negative bacterial (GNB) pathogens are on the rise, negatively impacting morbidity and mortality,...
Globally, infections due to multi-drug resistant (MDR) Gram-negative bacterial (GNB) pathogens are on the rise, negatively impacting morbidity and mortality, necessitating urgent treatment alternatives. Herein, we report a detailed bio-evaluation of an ultrashort, cationic lipopeptide 'SVAP9I' that demonstrated potent antibiotic activity and acted as an adjuvant to potentiate existing antibiotic classes towards GNBs. Newly synthesized lipopeptides were screened against ESKAPE pathogens and cytotoxicity assays were performed to evaluate the selectivity index (SI). SVAP9I exhibited broad-spectrum antibacterial activity against critical MDR-GNB pathogens including members of Enterobacteriaceae (MIC 4-8 mg/L), with a favorable CC value of ≥100 mg/L and no detectable resistance even after 50th serial passage. It demonstrated fast concentration-dependent bactericidal action as determined via time-kill analysis and also retained full potency against polymyxin B-resistant E. coli, indicating distinct mode of action. SVAP9I targeted E. coli's outer and inner membranes by binding to LPS and phospholipids such as cardiolipin and phosphatidylglycerol. Membrane damage resulted in ROS generation, depleted intracellular ATP concentration and a concomitant increase in extracellular ATP. Checkerboard assays showed SVAP9I's synergism with narrow-spectrum antibiotics like vancomycin, fusidic acid and rifampicin, potentiating their efficacy against MDR-GNB pathogens, including carbapenem-resistant Acinetobacter baumannii (CRAB), a WHO critical priority pathogen. In a murine neutropenic thigh infection model, SVAP9I and rifampicin synergized to express excellent antibacterial efficacy against MDR-CRAB outcompeting polymyxin B. Taken together, SVAP9I's distinct membrane-targeting broad-spectrum action, lack of resistance and strong in vitro andin vivopotency in synergism with narrow spectrum antibiotics like rifampicin suggests its potential as a novel antibiotic adjuvant for the treatment of serious MDR-GNB infections.
Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Microbial Sensitivity Tests; Mice; Lipopeptides; Cell Membrane; Gram-Negative Bacterial Infections; Drug Synergism; Female; Humans; Adjuvants, Pharmaceutic
PubMed: 38823276
DOI: 10.1016/j.biopha.2024.116810 -
Journal of Hazardous Materials Aug 2024The fetus and infants are particularly vulnerable to Cadmium (Cd) due to the immaturity of the blood-brain barrier. In utero and early life exposure to Cd is associated...
PLCβ4 driven by cadmium-exposure during gestation and lactation contributes to cognitive deficits by suppressing PIP2/PLCγ1/CREB/BDNF signaling pathway in male offspring.
The fetus and infants are particularly vulnerable to Cadmium (Cd) due to the immaturity of the blood-brain barrier. In utero and early life exposure to Cd is associated with cognitive deficits. Although such exposure has attracted widespread attention, its gender-specificity remains controversial, and there are no reports disclosing the underlying mechanism of gender‑specific neurotoxicity. We extensively evaluated the learning and cognitive functions and synaptic plasticity of male and female rats exposed to maternal Cd. Maternal Cd exposure induced learning and memory deficits in male offspring rats, but not in female offspring rats. PLCβ4 was identified as a critical protein, which might be related to the gender‑specific cognitive deficits in male rats. The up-regulated PLCβ4 competed with PLCγ1 to bind to PIP2, which counteracted the hydrolysis of PIP2 by PLCγ1. The decreased activation of PLCγ1 inhibited the phosphorylation of CREB to reduce BDNF transcription, which consequently resulted in the damage of hippocampal neurons and cognitive deficiency. Moreover, the low level of BDNF promoted AEP activation to induce Aβ deposition in the hippocampus. These findings highlight that PLCβ4 might be a potential target for the therapy of learning and cognitive deficits caused by Cd exposure in early life.
Topics: Animals; Female; Male; Pregnancy; Cadmium; Brain-Derived Neurotrophic Factor; Phospholipase C gamma; Signal Transduction; Cyclic AMP Response Element-Binding Protein; Prenatal Exposure Delayed Effects; Hippocampus; Lactation; Cognitive Dysfunction; Phospholipase C beta; Rats, Sprague-Dawley; Phosphatidylinositol 4,5-Diphosphate; Maternal Exposure; Rats
PubMed: 38820747
DOI: 10.1016/j.jhazmat.2024.134756 -
Frontiers in Bioscience (Landmark... Apr 2024Ovarian cancer is a highly lethal gynecologic malignancy. ARHGAP10, a member of Rho GTPase-activating proteins, is a potential tumor suppressor in ovarian cancer....
BACKGROUND
Ovarian cancer is a highly lethal gynecologic malignancy. ARHGAP10, a member of Rho GTPase-activating proteins, is a potential tumor suppressor in ovarian cancer. However, its role and the involved mechanism need further examination. Here, we investigated whether ARHGAP10 is also associated with ferroptosis.
METHODS
Lentivirus infection was used for gene overexpression or silencing. Real-time polymerase chain reaction (RT-PCR) and Western blot were used to assess mRNA and protein levels, respectively. Cell viability was assessed by Cell Counting Kit-8 (CCK-8) assay. Lipid reactive oxygen species level was measured by flow cytometry. A tumorigenicity assay was performed to evaluate tumor growth , and sections of mouse tumor tissues were examined by immunofluorescence microscopy. Chromatin Immunoprecipitation (ChIP) assay was used to assess the binding of H3K9ac to the promoter region of ARHGAP10.
RESULTS
ARHGAP10 overexpression promoted ferroptosis in ovarian cancer cells, resulting in decreased cell viability, and increased lipid reactive oxygen species (ROS) level. Further, it decreased and increased GPX4 and PTGS2 expression, respectively, and also induced suppression of tumor growth in mice. Fer-1, a potent inhibitor of ferroptosis, suppressed the above effects of ARHGAP10. Contrarily, ARHGAP10 silencing alleviated ferroptosis in ovarian cancer cells, which was reversed by RSL3, a ferroptosis-inducing agent. Lastly, sodium butyrate (SB) was found to transcriptionally regulate ARHGAP10, thereby also contributing to the ferroptosis of ovarian cancer cells.
CONCLUSIONS
Our results suggest that SB/ARHGAP10/GPX4 is a new signaling axis involved in inducing ferroptosis in ovarian cancer cells and suppressing tumor growth, which has potential clinical significance.
Topics: Ferroptosis; Female; Ovarian Neoplasms; Humans; Animals; GTPase-Activating Proteins; Cell Line, Tumor; Reactive Oxygen Species; Butyric Acid; Gene Expression Regulation, Neoplastic; Mice; Mice, Nude; Cell Survival; Phospholipid Hydroperoxide Glutathione Peroxidase
PubMed: 38812318
DOI: 10.31083/j.fbl2905167 -
Contact (Thousand Oaks (Ventura County,... 2024One means by which cells reutilize neutral lipids stored in lipid droplets is to degrade them by autophagy. This process involves spartin, mutations of which cause the...
One means by which cells reutilize neutral lipids stored in lipid droplets is to degrade them by autophagy. This process involves spartin, mutations of which cause the rare inherited disorder Troyer syndrome (or spastic paraplegia-20, SPG20). A recently published paper from the team led by Karin Reinsich (Yale) suggests that the molecular function of spartin and its unique highly conserved "senescence" domain is as a lipid transfer protein. Spartin binds to and transfers all lipid species found in lipid droplets, from phospholipids to triglycerides and sterol esters. This lipid transfer activity correlates with spartin's ability to sustain lipid droplet turnover. The senescence domain poses an intriguing question around the wide range of its cargoes, but intriguingly it has yet to yield up its secrets because attempts at crystallization failed and AlphaFold's prediction is unconvincing.
PubMed: 38808280
DOI: 10.1177/25152564241255782 -
Phytomedicine : International Journal... Jul 2024In acute kidney injury (AKI), ferroptosis is the main mechanism of cell death in the renal tubular epithelium. Baicalein, a traditional Chinese medicine monomer, plays a...
BACKGROUND
In acute kidney injury (AKI), ferroptosis is the main mechanism of cell death in the renal tubular epithelium. Baicalein, a traditional Chinese medicine monomer, plays a protective role in various kidney diseases; however, the effect of baicalein on ferroptosis in AKI still needs further exploration.
PURPOSE
In this study, we explored the role of baicalein and its specific mechanism in mediating ferroptosis in cisplatin-induced AKI.
METHODS
We used a cisplatin-induced AKI model to study the effects of baicalein on renal tissue and tubular epithelial cell injury. The effects of baicalein on tubular epithelial cell ferroptosis were detected in cisplatin-induced AKI and further verified by folic acid-induced AKI. The Swiss Target Prediction online database was used to predict the possible mechanism by which baicalein regulates ferroptosis, and the specific target proteins were further verified. Molecular docking and SPR were used to further determine the binding potential of baicalein to the target protein. Finally, RNA interference (RNAi) technology and enzymatic inhibition were used to determine whether baicalein regulates ferroptosis through target proteins.
RESULTS
Baicalein alleviated cisplatin- and folic acid-induced renal dysfunction and pathological damage and improved cisplatin-induced HK2 cell injury. Mechanistically, baicalein reduced the expression of 12-lipoxygenase (ALOX12), which inhibits phospholipid peroxidation and ferroptosis in AKI. Molecular docking and SPR demonstrated direct binding between baicalein and ALOX12. Finally, we found that silencing ALOX12 had a regulatory effect similar to that of baicalein. Comparable results were also obtained with the ALOX12 inhibitor ML355.
CONCLUSION
This was the first study to confirm that baicalein regulates ferroptosis both in vitro and in vivo in cisplatin-induced AKI and to verify the regulatory effect of baicalein in folic acid-induced AKI. Our results reveal the critical role of ALOX12 in kidney damage and ferroptosis caused by cisplatin and emphasize the regulatory effect of baicalein on renal tubular epithelial cell ferroptosis mediated by ALOX12. Baicalein is an effective drug for treating AKI, and ALOX12 is a potential drug target.
Topics: Flavanones; Ferroptosis; Acute Kidney Injury; Cisplatin; Animals; Arachidonate 12-Lipoxygenase; Male; Humans; Molecular Docking Simulation; Mice; Mice, Inbred C57BL; Folic Acid; Cell Line; Epithelial Cells; Kidney Tubules
PubMed: 38805781
DOI: 10.1016/j.phymed.2024.155757 -
Archives of Biochemistry and Biophysics Jul 2024Phosphatidylinositol 4,5-bisphosphate (PIP), as well as other anionic phospholipids, play a pivotal role in various cellular processes, including ion channel regulation,... (Review)
Review
Phosphatidylinositol 4,5-bisphosphate (PIP), as well as other anionic phospholipids, play a pivotal role in various cellular processes, including ion channel regulation, receptor trafficking, and intracellular signaling pathways. The binding of volatile anesthetics and propofol to PIP leads to alterations in PIP-mediated signaling causing modulation of ion channels such as ɣ-aminobutyric acid type A (GABA) receptors, voltage-gated calcium channels, and potassium channels through various mechanisms. Additionally, the interaction between anionic phospholipids and G protein-coupled receptors plays a critical role in various anesthetic pathways, with these anesthetic-induced changes impacting PIP levels which cause cascading effects on receptor trafficking, including GABA receptor internalization. This comprehensive review of various mechanisms of interaction provides insights into the intricate interplay between PIP signaling and anesthetic-induced changes, shedding light on the molecular mechanisms underlying anesthesia.
Topics: Propofol; Phosphatidylinositol 4,5-Diphosphate; Signal Transduction; Humans; Animals; Anesthetics, Inhalation; Receptors, GABA-A
PubMed: 38801966
DOI: 10.1016/j.abb.2024.110045