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NPJ Biofilms and Microbiomes Jun 2024Bacteria induced metamorphosis observed in nearly all marine invertebrates. However, the mechanism of bacteria regulating the larvae-juvenile metamorphosis remains...
Bacteria induced metamorphosis observed in nearly all marine invertebrates. However, the mechanism of bacteria regulating the larvae-juvenile metamorphosis remains unknown. Here, we test the hypothesis that c-di-GMP, a ubiquitous bacterial second-messenger molecule, directly triggers the mollusc Mytilus coruscus larval metamorphosis via the stimulator of interferon genes (STING) receptor. We determined that the deletion of c-di-GMP synthesis genes resulted in reduced c-di-GMP levels and biofilm-inducing activity on larval metamorphosis, accompanied by alterations in extracellular polymeric substances. Additionally, c-di-GMP extracted from tested varying marine bacteria all exhibited inducing activity on larval metamorphosis. Simultaneously, through pharmacological and molecular experiments, we demonstrated that M. coruscus STING (McSTING) participates in larval metamorphosis by binding with c-di-GMP. Our findings reveal that new role of bacterial c-di-GMP that triggers mussel larval metamorphosis transition, and extend knowledge in the interaction of bacteria and host development in marine ecosystems.
Topics: Animals; Metamorphosis, Biological; Larva; Cyclic GMP; Biofilms; Mytilus; Bacteria; Membrane Proteins
PubMed: 38902226
DOI: 10.1038/s41522-024-00523-7 -
Pharmacological Reviews Jun 2024The orexin system consists of the peptide transmitters orexin-A and -B and the G protein-coupled orexin receptors OX and OX Orexin receptors are capable of coupling to...
The orexin system consists of the peptide transmitters orexin-A and -B and the G protein-coupled orexin receptors OX and OX Orexin receptors are capable of coupling to all four families of heterotrimeric G proteins, and there are also other complex features of the orexin receptor signaling. The system was discovered 25 years ago and was immediately identified as a central regulator of sleep and wakefulness; this is exemplified by the symptomatology of the disorder narcolepsy with cataplexy, in which orexinergic neurons degenerate. Subsequent translation of these findings into drug discovery and development has resulted to date in three clinically used orexin receptor antagonists to treat insomnia. In addition to sleep and wakefulness, the orexin system appears to be a central player at least in addiction and reward, and has a role in depression, anxiety and pain gating. Additional antagonists and agonists are in development to treat, for instance, insomnia, narcolepsy with or without cataplexy and other disorders with excessive daytime sleepiness, depression with insomnia, anxiety, schizophrenia, as well as eating and substance use disorders. The orexin system has thus proved an important regulator of numerous neural functions and a valuable drug target. Orexin prepro-peptide and orexin receptors are also expressed outside the central nervous system, but their potential physiological role there remains unknown. The orexin system was discovered 25 years ago and immediately emerged as an essential sleep-wakefulness regulator. This discovery has tremendously increased the understanding of these processes and has thus far resulted in the market approval of three orexin receptor antagonists, which promote more physiological sleep than previous hypnotics. Further, orexin receptor agonists and antagonists with different pharmacodynamic properties are in development since research has revealed additional potential therapeutic indications. Orexin receptor signaling is complex and may represent novel features.
PubMed: 38902035
DOI: 10.1124/pharmrev.123.000953 -
Biological Psychiatry Jun 2024Substance use disorder (SUD) is characterized by long-lasting changes in reward-related brain regions, such as the nucleus accumbens (NAc). Previous work has shown that...
BACKGROUND
Substance use disorder (SUD) is characterized by long-lasting changes in reward-related brain regions, such as the nucleus accumbens (NAc). Previous work has shown that cocaine exposure induces plasticity in broad, genetically-defined cell types in the NAc; however, in response to a stimulus, only a small percent of neurons are transcriptionally active - termed an ensemble. Here, we identify an Arc-expressing neuronal ensemble that has a unique trajectory of recruitment and causally controls drug self-administration after repeated, but not acute, cocaine exposure.
METHOD
Using Arc-CreER transgenic mice, we expressed transgenes in Arc+ ensembles activated by cocaine exposure [either acute (1 x 10mg/kg IP), or repeated (10 x 10mg/kg IP)]. Using genetic, optical, and physiological recording and manipulation strategies, we assessed the contribution of these ensembles to behaviors associated with SUD.
RESULTS
Repeated cocaine exposure reduced the size of the ensemble, while simultaneously increasing its control over behavior. Neurons within the repeated cocaine ensemble were hyperexcitable and their optogenetic excitation was sufficient for reinforcement. Finally, lesioning the repeated cocaine, but not acute cocaine, ensemble blunted cocaine self-administration. Thus, repeated cocaine exposure reduced the size of the ensemble while simultaneously increasing its contributions to drug reinforcement.
CONCLUSIONS
We show that repeated, but not acute, cocaine exposure induces a physiologically distinct ensemble characterized by the expression of the immediate early gene Arc, that is uniquely capable of modulating reinforcement behavior.
PubMed: 38901723
DOI: 10.1016/j.biopsych.2024.06.008 -
STAR Protocols Jun 2024In rats, cannulation of the jugular vein and the carotid artery precedes the use of the hyperinsulinemic euglycemic clamp to determine insulin sensitivity in vivo....
In rats, cannulation of the jugular vein and the carotid artery precedes the use of the hyperinsulinemic euglycemic clamp to determine insulin sensitivity in vivo. Here, we present a vascular surgery protocol to allow the infusion of substances via the vein and the collection of blood samples from the artery on the day of the hyperinsulinemic euglycemic clamp. We describe steps for preparing for and performing catheterization surgery. We then detail procedures for clamp preparation and its use. For complete details on the use and execution of this protocol, please refer to Pereira et al..
PubMed: 38900633
DOI: 10.1016/j.xpro.2024.103143 -
World Journal of Clinical Cases Jun 2024Malancao (MLC) is a traditional Chinese medicine with a long history of utilization in treating ulcerative colitis (UC). Nevertheless, the precise molecular mechanisms...
BACKGROUND
Malancao (MLC) is a traditional Chinese medicine with a long history of utilization in treating ulcerative colitis (UC). Nevertheless, the precise molecular mechanisms underlying its efficacy remain elusive. This study leveraged ultra-high-performance liquid chromatography coupled with exactive mass spectrometry (UHPLC-QE-MS), network pharmacology, molecular docking (MD), and gene microarray analysis to discern the bioactive constituents and the potential mechanism of action of MLC in UC management.
AIM
To determine the ingredients related to MLC for treatment of UC using multiple databases to obtain potential targets for fishing.
METHODS
This research employs UHPLC-QE-MS for the identification of bioactive compounds present in MLC plant samples. Furthermore, the study integrates the identified MLC compound-related targets with publicly available databases to elucidate common drug disease targets. Additionally, the R programming language is utilized to predict the central targets and molecular pathways that MLC may impact in the treatment of UC. Finally, MD are conducted using AutoDock Vina software to assess the affinity of bioactive components to the main targets and confirm their therapeutic potential.
RESULTS
Firstly, through a comprehensive analysis of UHPLC-QE-MS data and public database resources, we identified 146 drug-disease cross targets related to 11 bioactive components. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis highlighted that common disease drug targets are primarily involved in oxidative stress management, lipid metabolism, atherosclerosis, and other processes. They also affect AGE-RAGE and apoptosis signaling pathways. Secondly, by analyzing the differences in diseases, we identified key research targets. These core targets are related to 11 active substances, including active ingredients such as quercetin and luteolin. Finally, MD analysis revealed the stability of compound-protein binding, particularly between JUN-Luteolin, JUN-Quercetin, HSP90AA1-Wogonin, and HSP90AA1-Rhein. Therefore, this suggests that MLC may help alleviate intestinal inflammation in UC, restore abnormal lipid accumulation, and regulate the expression levels of core proteins in the intestine.
CONCLUSION
The utilization of MLC has demonstrated notable therapeutic efficacy in the management of UC by means of the compound target interaction pathway. The amalgamation of botanical resources, metabolomics, natural products, MD, and gene chip technology presents a propitious methodology for investigating therapeutic targets of herbal medicines and discerning novel bioactive constituents.
PubMed: 38898844
DOI: 10.12998/wjcc.v12.i17.3105 -
Nature Communications Jun 2024Methaqualone, a quinazolinone marketed commercially as Quaalude, is a central nervous system depressant that was used clinically as a sedative-hypnotic, then became a...
Methaqualone, a quinazolinone marketed commercially as Quaalude, is a central nervous system depressant that was used clinically as a sedative-hypnotic, then became a notorious recreational drug in the 1960s-80s. Due to its high abuse potential, medical use of methaqualone was eventually prohibited, yet it persists as a globally abused substance. Methaqualone principally targets GABA receptors, which are the major inhibitory neurotransmitter-gated ion channels in the brain. The restricted status and limited accessibility of methaqualone have contributed to its pharmacology being understudied. Here, we use cryo-EM to localize the GABA receptor binding sites of methaqualone and its more potent derivative, PPTQ, to the same intersubunit transmembrane sites targeted by the general anesthetics propofol and etomidate. Both methaqualone and PPTQ insert more deeply into subunit interfaces than the previously-characterized modulators. Binding of quinazolinones to this site results in widening of the extracellular half of the ion-conducting pore, following a trend among positive allosteric modulators in destabilizing the hydrophobic activation gate in the pore as a mechanism for receptor potentiation. These insights shed light on the underexplored pharmacology of quinazolinones and further elucidate the molecular mechanisms of allosteric GABA receptor modulation through transmembrane binding sites.
Topics: Receptors, GABA-A; Binding Sites; Cryoelectron Microscopy; Humans; Animals; Etomidate; Propofol; Quinazolinones; Allosteric Regulation; HEK293 Cells; Hypnotics and Sedatives
PubMed: 38898000
DOI: 10.1038/s41467-024-49471-y -
Applied Microbiology and Biotechnology Jun 2024Bacterial biofilms commonly cause chronic and persistent infections in humans. Bacterial biofilms consist of an inner layer of bacteria and an autocrine extracellular... (Review)
Review
Bacterial biofilms commonly cause chronic and persistent infections in humans. Bacterial biofilms consist of an inner layer of bacteria and an autocrine extracellular polymeric substance (EPS). Biofilm dispersants (abbreviated as dispersants) have proven effective in removing the bacterial physical protection barrier EPS. Dispersants are generally weak or have no bactericidal effect. Bacteria dispersed from within biofilms (abbreviated as dispersed bacteria) may be more invasive, adhesive, and motile than planktonic bacteria, characteristics that increase the probability that dispersed bacteria will recolonize and cause reinfection. The dispersants should be combined with antimicrobials to avoid the risk of severe reinfection. Dispersant-based nanoparticles have the advantage of specific release and intense penetration, providing the prerequisite for further antibacterial agent efficacy and achieving the eradication of biofilms. Dispersant-based nanoparticles delivered antimicrobial agents for the treatment of diseases associated with bacterial biofilm infections are expected to be an effective measure to prevent reinfection caused by dispersed bacteria. KEY POINTS: • Dispersed bacteria harm and the dispersant's dispersion mechanisms are discussed. • The advantages of dispersant-based nanoparticles in bacteria biofilms are discussed. • Dispersant-based nanoparticles for cutting off reinfection in vivo are highlighted.
Topics: Biofilms; Nanoparticles; Anti-Bacterial Agents; Humans; Bacteria; Bacterial Infections; Reinfection; Extracellular Polymeric Substance Matrix
PubMed: 38896257
DOI: 10.1007/s00253-024-13120-7 -
Molecules (Basel, Switzerland) Jun 2024The present work deals with the sol-gel synthesis of silica-poly (vinylpyrrolidone) hybrid materials. The nanohybrids (Si-PVP) have been prepared using an acidic...
The present work deals with the sol-gel synthesis of silica-poly (vinylpyrrolidone) hybrid materials. The nanohybrids (Si-PVP) have been prepared using an acidic catalyst at ambient temperature. Tetramethyl ortosilane (TMOS) was used as a silica precursor. Poly (vinylpyrrolidone) (PVP) was introduced into the reaction mixture as a solution in ethanol with a concentration of 20%. The XRD established that the as-prepared material is amorphous. The IR and Si MAS NMR spectra proved the formation of a polymerized silica network as well as the hydrogen bonding interactions between the silica matrix and OH hydrogens of the silanol groups. The TEM showed spherical particle formation along with increased agglomeration tendency. The efficacy of SiO/PVP nanoparticles as a potential antimicrobial agent against a wide range of bacteria was evaluated as bacteriostatic, using agar diffusion and spot tests. Combined effects of hybrid nanomaterial and antibiotics could significantly reduce the bactericidal concentrations of both the antibiotic and the particles, and they could also eliminate the antibiotic resistance of the pathogen. The registered prooxidant activity of the newly synthesized material was confirmative and explicatory for the antibacterial properties of the tested substance and its synergetic combination with antibiotics. The effect of new hybrid material on Crustacea was also estimated as harmless under concentration of 0.1 mg/mL.
Topics: Silicon Dioxide; Anti-Bacterial Agents; Povidone; Microbial Sensitivity Tests; Nanoparticles; Phase Transition; Bacteria
PubMed: 38893548
DOI: 10.3390/molecules29112675 -
Molecules (Basel, Switzerland) Jun 2024Oridonin (Ori) is a naturally existing diterpenoid substance that mainly exists in the Chinese medicinal plant Rabdosia rubescens. It was previously found to possess...
Oridonin (Ori) is a naturally existing diterpenoid substance that mainly exists in the Chinese medicinal plant Rabdosia rubescens. It was previously found to possess intriguing biological properties; however, the quick clearance from plasma and limited solubility in water restricts its use as a drug. Several metal-organic frameworks (MOFs), having big surfaces and large pores, have recently been considered promising drug transporters. The zeolitic imidazolate framework-8 (ZIF-8), a form of MOF consisting of 2-methylimidazole with zinc ions, is structurally stable under physiologically neutral conditions, while it can degrade at low pH values such as in tumor cells. Herein, a nanosized drug delivery system, Ori@ZIF-8, was successfully designed for encapsulating and transporting oridonin to the tumor site. The drug loading of the prepared Ori@ZIF-8 was 26.78%, and the particles' mean size was 240.5 nm. In vitro, the release of Ori@ZIF-8 exhibited acid sensitivity, with a slow release under neutral conditions and rapid release of the drug under weakly acidic conditions. According to the in vitro anti-tumor experiments, Ori@ZIF-8 produced higher cytotoxicity than free Ori and induced apoptosis in A549 cancer cells. In conclusion, Ori@ZIF-8 could be a potential pH-responsive carrier to accurately release more oridonins at the tumor site.
Topics: Diterpenes, Kaurane; Metal-Organic Frameworks; Humans; Hydrogen-Ion Concentration; Drug Delivery Systems; Drug Liberation; Drug Carriers; A549 Cells; Cell Line, Tumor; Zeolites; Neoplasms; Antineoplastic Agents; Cell Survival; Imidazoles
PubMed: 38893518
DOI: 10.3390/molecules29112643 -
Molecules (Basel, Switzerland) Jun 2024Kostel. is a species of mangrove used in traditional Ayurvedic medicine for treating inflammatory conditions. The present study aims to establish monographic botanical...
Kostel. is a species of mangrove used in traditional Ayurvedic medicine for treating inflammatory conditions. The present study aims to establish monographic botanical and chemical quality criteria for leaf and bark as herbal substances and to evaluate their in vitro antioxidant potential. Macroscopic and microscopic qualitative and quantitative analyses, chemical LC-UV/DAD-ESI/MS profiling, and the quantification of key chemical classes were performed. Antioxidant activity was evaluated by DPPH and FRAP assays. Macroscopically, the leaf is asymmetrical with an emarginated apex and cuneate base. Microscopically, it shows features such as two-layered adaxial palisade parenchyma, vascular bundles surrounded by 3-6 layers of sclerenchyma, prismatic calcium oxalate crystals (5.89 ± 1.32 μm) along the fibers, paracytic stomata only on the abaxial epidermis (stomatal index-20.15), and non-glandular trichomes only on petiolules. The microscopic features of the bark include a broad cortex with large lignified sclereids, prismatic calcium oxalate crystals (8.24 ± 1.57 μm), and secondary phloem with distinct 2-5 seriated medullary rays without crystals. Chemical profile analysis revealed that phenolic derivatives, mainly condensed tannins and flavonoids, are the main classes identified. A total of 22 marker compounds were tentatively identified in both plant parts. The major compounds identified in the leaf were quercetin-3--glucoside and taxifolin pentoside and in the bark were B-type dimeric proanthocyanidins and taxifolin 3--rhamnoside. The total phenolics content was higher in the leaf (1521 ± 4.71 mg GAE/g dry weight), while the total flavonoids and condensed tannins content were higher in the bark (82 ± 0.58 mg CE/g and 1021 ± 5.51 mg CCE/g dry weight, respectively). A total of 70% of the hydroethanolic extracts of leaf and bark showed higher antioxidant activity than the ascorbic acid and concentration-dependent scavenging activity in the DPPH assay (IC 23.95 ± 0.93 and 23.63 ± 1.37 µg/mL, respectively). A positive and statistically significant ( < 0.05) correlation between the phenol content and antioxidant activity was found. The results obtained will provide important clues for the quality control criteria of leaf and bark, as well as for the knowledge of their pharmacological potential as possible anti-inflammatory agents with antioxidant activity.
Topics: Plant Bark; Plant Leaves; Antioxidants; Plant Extracts; Plants, Medicinal; Flavonoids; Phytochemicals; Herbal Medicine; Phenols; Proanthocyanidins
PubMed: 38893505
DOI: 10.3390/molecules29112629