Site Of Action Research Articles

Evaluation of Pyroxasulfone Crop Safety and Weed Control for California Tree Nut Orchards

Pyroxasulfone is a very long chain fatty acid (VLCFA) inhibitor (group 15) with potential for preemergence weed control in orchard crops and would be beneficial for reducing selection pressure for resistance to more commonly used herbicides, such as glyphosate. Pyroxasulfone is registered and widely used in corn and soybeans in the United States as a solo product and in several premix formulations. However, there is limited published information on the performance and safety of pyroxasulfone in tree nut orchard systems. To assess the potential fit for pyroxasulfone in this crop sector, a series of crop safety and weed control efficacy experiments were carried out in key California orchard crops and in fallow fields with common orchard weeds. The non-crop studies were conducted near Davis, CA, to evaluate winter annual weed control with pyroxasulfone in comparison with pendimethalin and indaziflam. In addition, an irrigation incorporation experiment was conducted in summer to evaluate the effects of incorporation timing on pyroxasulfone, pendimethalin, and indaziflam efficacy as a measure of relative stability. Orchard weed control experiments were conducted in spring in an almond orchard near Arbuckle, CA, and a walnut orchard near Davis, CA. The orchard experiments included pyroxasulfone, pendimethalin, and indaziflam in various rate combinations with glufosinate. To evaluate crop safety, 2-year experiments were conducted to evaluate repeated applications of above-label rates of pyroxasulfone at 1199 g·ha−1 and S-metolachlor at 14,010 g·ha−1 on 1- to 2-year-old almond, pistachio, and walnut trees near Davis. Pyroxasulfone performed similarly to commercial standards with up to 95% control of broadleaf and grass weeds with pyroxasulfone and indaziflam providing 96% to 100% control of annual bluegrass, and pyroxasulfone (293 g·ha−1) being the only herbicide to suppress (>70%) common lambsquarters at 60 days after treatment (DAT). Other weeds controlled by pyroxasulfone include swinecress, redroot pigweed, yellow nutsedge, and Italian ryegrass. No differences were found among treatments in the incorporation timing study indicating adequate stability on the soil surface under summer conditions. Crop injury was not observed in the established orchards or the young orchard studies and there were no treatment effects on tree trunk diameter of almond, pistachio, and walnut in the 2-year crop safety experiments. These results indicate a potential for pyroxasulfone in California tree nut orchard systems that would be an additional site of action and beneficial for management of herbicide-resistant weeds in these crops.

Prodrug activation in malaria parasites mediated by an imported erythrocyte esterase, acylpeptide hydrolase (APEH).

The continued emergence of antimalarial drug resistance highlights the need to develop new antimalarial therapies. Unfortunately, new drug development is often hampered by poor drug-like properties of lead compounds. Prodrugging temporarily masks undesirable compound features, improving bioavailability and target penetration. We have found that lipophilic diester prodrugs of phosphonic acid antibiotics, such as fosmidomycin, exhibit significantly higher antimalarial potency than their parent compounds (1). However, the activating enzymes for these prodrugs were unknown. Here, we show that an erythrocyte enzyme, acylpeptide hydrolase (APEH) is the major activating enzyme of multiple lipophilic ester prodrugs. Surprisingly, this enzyme is taken up by the malaria parasite, Plasmodium falciparum, where it localizes to the parasite cytoplasm and retains enzymatic activity. Using a novel fluorogenic ester library, we characterize the structure activity relationship of APEH, and compare it to that of P. falciparum esterases. We show that parasite-internalized APEH plays an important role in the activation of substrates with branching at the alpha carbon, in keeping with its exopeptidase activity. Our findings highlight a novel mechanism for antimicrobial prodrug activation, relying on a host-derived enzyme to yield activation at a microbial target. Mutations in prodrug activating enzymes are a common mechanism for antimicrobial drug resistance (2-4). Leveraging an internalized host enzyme would circumvent this, enabling the design of prodrugs with higher barriers to drug resistance.

Genipin 1-O-β-D-gentiobioside ameliorates CUMS-induced prefrontal cortex neuron neuronal apoptosis by modulating HIPK2 SUMOylation

BackgroundDepression is a common mental illness with more than 280 million sufferers worldwide. Inflammation, particularly the c-Jun amino-terminal kinase (JNK) pathway, contributes to depression development and neuronal apoptosis. Gardenia is a herb with therapeutic effects on depression that has been shown to inhibit neuronal apoptosis. However, one of the components in gardenia, Genipin 1-O-β-D-gentiobioside(GG), has been less studied for its mechanism on depression. Thus, in the current study, we investigate how Genipin 1-O-β-D-gentiobioside improves depression and elucidate its possible mechanism of action. MethodsIn this investigation, we utilize a chronic unpredictable mild stress (CUMS) mouse model and corticosterone-induced primary cortical neurons to examine the role of GG in ameliorating depressive symptoms and neuronal apoptosis. TUNEL staining and flow cytometry assessed the effects of GG on neuronal apoptosis. Western Blot analyses and immunofluorescence assays apoptosis-related proteins in the prefrontal cortex and primary neurons. The site of action of GG in regulating homeodomain interacting protein kinase 2 (HIPK2) SUMOylation was further explored in primary neurons. We constructed siRNA-SUMO1 vectors to transfect primary neuronal cells with intracellular SUMO1 knockdown. Proximity ligation assay (PLA) experiments were performed on primary neurons according to the instructions of the assay kit to observe the physical relationship between HIPK2 and SUMO1. We predicted the HIPK2 SUMOylation modification site by an online database and constructed vectors to target and site-directed mutagenesis, then to transfected primary neuronal cells. ResultsThe results showed that GG effectively alleviated depressive-like behaviours, down-regulated apoptosis-related proteins (p-JNK, Bax, Cleaved-Caspase-3), and inhibited neuronal apoptosis in CUMS-induced depressed mice and corticosterone-induced primary cortical neurons. We reveal a complex mechanism underlying the link between GG, SUMOylation of HIPK2, and complex pathways of neuronal apoptosis regulation. K326 and K1189 are the key SUMOylation sites regulated by GG in intricate interactions of apoptosis-related proteins. ConclusionOur study demonstrated that GG exerts antidepressant-like actions through neuroprotective effects by inhibiting the apoptosis of prefrontal cortex neurons, revealing the mechanism of GG inhibition of JNK phosphorylation by enhancing HIPK2 SUMOylation.

Mechanistic Differences between Torsemide and Furosemide.

Torsemide is proposed to have clinically important pharmacokinetic and pharmacodynamic advantages over furosemide. However, clinical outcomes did not differ in the Torsemide Comparison with Furosemide for Management of Heart Failure (TRANSFORM-HF) randomized trial. We conducted a multicenter mechanistic substudy of patients with heart failure randomized to oral furosemide or torsemide (TRANSFORM-Mechanism). At baseline and 30 days, participants underwent detailed assessments of pharmacokinetic and pharmacodynamic parameters. TRANSFORM-Mechanism enrolled 88 participants. Kidney bioavailability, or the proportion of dose delivered to the tubular site of action, was significantly less with torsemide compared to furosemide [median 17.1%, (IQR 12.3, 23.5%) vs. 24.8% (16.6, 34.1%), p < 0.001]. Furosemide had a longer duration of kidney drug delivery and duration of natriuresis (p≤0.004 for both). Prescribed doses of furosemide and torsemide in TRANSFORM-Mechanism were similar to TRANSFORM-HF, with providers on average using a 2:1 dose equivalence conversion between drugs. However, these doses resulted in a substantially greater natriuresis with torsemide (p<0.001). A dose equivalence of ∼4:1 resulted in similar natriuresis. Higher diuretic doses in the torsemide group resulted in mild perturbations in kidney function and significant increases in renin, aldosterone, and norepinephrine (p<0.05 for all). Plasma volume (p=0.52) and body weight (p=0.89) did not improve with torsemide vs. furosemide. We observed no meaningful pharmacokinetic/pharmacodynamic advantages for torsemide vs. furosemide. The greater natriuresis from higher diuretic doses in the torsemide group was offset by greater neurohormonal activation and kidney dysfunction.

Prolonged release from lipid nanoemulsions by modification of drug lipophilicity

In addition to the solubilization of poorly water-soluble, highly lipophilic drugs, lipid nanoemulsions bear potential for drug targeting approaches. This requires that the drug remains within the emulsion droplets until they reach the site of action. Since drug release is rather controlled by the lipophilicity of the drug than by the formulation, this study systematically investigated the influence of drug lipophilicity on the course of drug transfer in (physiological) acceptor media. An increase in drug lipophilicity, according to ClogD/P values, was achieved by the formation of lipophilic prodrugs of 5-phenylanthranilic acid – a potential pathoblocker. The range of substances was supplemented by orlistat, lumefantrine and cholesteryl acetate as model drugs. Drug transfer from supercooled trimyristin nanodroplets was determined via differential scanning calorimetry by monitoring their onset crystallization temperature, which decreases linearly with increasing drug content. Release of the model (pro)drugs ranged from burst to hardly any release in the order of the ClogD/P values. Except for cholesteryl acetate, the results were in line with the lipophilicity of the model (pro)drugs estimated by their retention times on a reversed-phase HPLC column under isocratic conditions. An approximate prediction of drug release kinetics was, thus, possible by logP calculations and, to a limited extent, also by reversed-phase HPLC. A further finding was the increased drug loading capacity of the lipid nanoemulsion for lipophilic prodrugs, if the structural changes of the parent compound were accompanied by a lower melting point.

Development of an In-situ Nasal Gel Formulation of Bepotastine Besilate for the Treatment of Allergic Rhinitis

The objective of this research was to formulate and evaluate mucoadhesive in situ nasal gels as a novel delivery system for Bepotastine Besilate. Aiming to provide sustained drug release directly at the site of action, thereby reducing the need for frequent dosing due to the drug's rapid absorption and short half-life. A series of eight formulations were developed using varying ratios of Poloxamer 407 and Poloxamer 188. The formulations exhibited a visually clear sol phase, indicating uniform dispersion of ingredients, with gelling temperatures ranging from 33.3±0.41 to 36.7±0.73°C. The gelling time, an important parameter for user convenience and efficacy, ranged from 15.7±01.52 to 43.3±20.80 s, meeting practical application requirements. Furthermore, all formulations consistently achieved a drug content of over 95%, ensuring dosage uniformity and efficacy. The pH values of the formulations were within the acceptable range of 6.13±0.10 to 6.91±0.02, minimizing the risk of mucosal irritation upon application. Importantly, the mucoadhesive strength ranged from 1056±0.32 to 6456± 045 dyne/cm², indicating robust adhesion to nasal mucosa, which is critical for prolonged drug retention and sustained release. In vitro drug release studies demonstrated sustained release profiles exceeding 4 hours for all formulations, following Higuchi kinetics, suggesting controlled drug release from the gel matrix. Accelerated stability studies corroborated the formulations' stability over the test period, indicating their potential for long-term storage and commercial viability. Additionally, FTIR analysis revealed no evidence of drug-polymer interactions, confirming the compatibility of Bepotastine Besilate with the selected polymer matrix. These comprehensive findings support the potential of in situ nasal gels as an effective and promising strategy for enhancing the therapeutic efficacy of Bepotastine Besilate, thereby improving patient outcomes.

Nanocarriers' repartitioning of drugs between blood subcompartments as a mechanism of improving pharmacokinetics, safety, and efficacy

For medical emergencies, such as acute ischemic stroke, rapid drug delivery to the target site is essential. For many small molecule drugs, this goal is unachievable due to poor solubility that prevents intravenous administration, and less obviously, by extensive partitioning to plasma proteins and red blood cells (RBCs), which greatly slows delivery to the target. Here we study these effects and how they can be solved by loading into nanoscale drug carriers. We focus on fingolimod, a small molecule drug that is FDA-approved for treatment of multiple sclerosis, which has also shown promise in the treatment of stroke. Unfortunately, fingolimod has poor solubility and very extensive partitioning to plasma proteins and RBCs (in whole blood, 86% partitions to RBCs, 13.96% to plasma proteins, and 0.04% is free). We develop a liposomal formulation that slows the partitioning of fingolimod to RBCs and plasma proteins, enables intravenous delivery, and additionally prevents fingolimod toxicity to RBCs. The liposomal formulation nearly completely prevented fingolimod adsorption to plasma proteins (association with plasma proteins was 98.4 ± 0.4% for the free drug vs. 5.6 ± 0.4% for liposome-loaded drug). When incubated with whole blood in vitro, the liposomal formulation greatly slowed partitioning of fingolimod to RBCs and also eliminated deleterious effects of fingolimod on RBC rigidity, morphology, and hemolysis. In vivo, the liposomal formulation delayed fingolimod partitioning to RBCs for over 30 min, a critical time window for stroke. Fingolimod-loaded liposomes showed improved efficacy in a mouse model of post-stroke neuroinflammation, completely sealing the leaky blood-brain barrier (114 ± 11.5% reduction in albumin leak into the brain for targeted liposomes vs. 38 ± 16.5% reduction for free drug). This effect was only seen for liposomes modified with antibodies to enable targeted delivery to the site of action, and not in unmodified, long-circulating liposomes. Thus, loading fingolimod into liposomes prevented partitioning to RBCs and associated toxicities and enabled targeted delivery. This paradigm can be used for tuning the blood distribution of small molecule drugs for the treatment of acute illnesses requiring rapid pharmacologic intervention.

A negatively charged cluster in the disordered acidic domain of GPIHBP1 provides selectivity in the interaction with lipoprotein lipase

GPIHBP1 is a membrane protein of endothelial cells that transports lipoprotein lipase (LPL), the key enzyme in plasma triglyceride metabolism, from the interstitial space to its site of action on the capillary lumen. An intrinsically disordered highly negatively charged N-terminal domain of GPIHBP1 contributes to the interaction with LPL. In this work, we investigated whether the plethora of heparin-binding proteins with positively charged regions found in human plasma affect this interaction. We also wanted to know whether the role of the N-terminal domain is purely non-specific and supportive for the interaction between LPL and full-length GPIHBP1, or whether it participates in the specific recognition mechanism. Using surface plasmon resonance, affinity chromatography, and FRET, we were unable to identify any plasma component, besides LPL, that bound the N-terminus with detectable affinity or affected its interaction with LPL. By examining different synthetic peptides, we show that the high affinity of the LPL/N-terminal domain interaction is ensured by at least ten negatively charged residues, among which at least six must sequentially arranged. We conclude that the association of LPL with the N-terminal domain of GPIHBP1 is highly specific and human plasma does not contain components that significantly affect this complex.

Amitriptyline and duloxetine attenuate activities of superficial dorsal horn neurons in a rat reserpine-induced fibromyalgia model

Fibromyalgia (FM) is an intractable disease with a chief complaint of chronic widespread pain. Amitriptyline (AMI) and duloxetine (DLX), which are antidepressant drugs, have been reported to ameliorate pain in patients with FM and pain-related behaviors in several rodent models of FM. However, the mechanisms of action of AMI and DLX are not yet fully understood. Here, we examined the effects of these drugs on the responsiveness of superficial dorsal horn (SDH) neurons in the spinal cord, using a rat FM model developed by injecting a biogenic amine depleter (reserpine). Extracellular recordings of SDH neurons in vivo demonstrated that bath application of AMI and DLX at concentrations of 0.1–1.0 mM on the dorsal surface of the spinal cord markedly suppressed spontaneous discharge and von Frey filament-evoked mechanical firing in SDH neurons. The suppression induced by the drugs was noted in a concentration-dependent manner and the suppressive effects resolved after washing the spinal cord surface. These results show that SDH neurons are the site of action for AMI and DLX in a rat reserpine-induced FM model. Spinal mechanisms may underlie the therapeutic effects of these drugs in patients with FM.

Comprehensive Analysis of Drug-Induced Parkinson-like Events.

Specific drugs are well known to have the capacity to induce Parkinson-like symptoms. Parkinson-like events are side effects that may persist for an extended period even after drug administration is discontinued. Although these events can be triggered by various drugs, the mechanisms underlying their diverse symptoms remain largely unclear. To investigate this, we used the Japanese Adverse Drug Event Reporting Database, which is maintained by the Pharmaceuticals and Medical Devices Agency, to analyze the risk factors associated with Parkinson-like events along with the associated drug trends and characteristics. Our findings indicate that similar to Parkinson's disease, age-related differences affect the onset of these reported events, with older individuals being more susceptible. Hierarchical clustering and principal component analysis revealed that the mechanisms triggering these Parkinson-like events are consistent across reports, suggesting a common underlying cause. However, even with a consistent mechanism, the side effects can vary depending on the site of action. These insights underline the importance of the swift identification of the drugs suspected of causing these events and the implementation of measures to reduce their side effects.

Synthesis of a novel adapter lipid using Fc-region mediated antibody modification for post-insert preparation of transferrin receptor targeted messenger RNA-loaded lipid nanoparticles

Lipid nanoparticles (LNPs) are promising delivery systems with the ability to deliver small interfering RNA (siRNA) and messenger RNA (mRNA) in diseased tissues and intracellular sites of action. However, delivery to non-hepatic tissues via systemic administration remains challenging. Antibody modification of LNPs is a hopeful approach for improving their selectivity to target tissues. The conventional method of antibody modification via thiol–maleimide linkage is concerned with reduced recognition efficiency of the disease-related target molecules owing to variations in antibody orientation on the surface of the LNPs. In this study, we developed a novel adapter lipopeptide for antibody modification of LNPs via the Fc-region. Here, we selected RI7-217, an anti-transferrin receptor antibody, as the ligand. Through optimization of spacer peptides, we found a FcBP-EKGG-lipid exhibits high water-dispersibility for post-insertion method to LNPs. We prepared RI7-217-modified LNPs by modifying LNPs with FcBP-EKGG-lipids and mixing the antibodies. We found that the luciferase protein expression of RI7-217-modified LNPs was significantly enhanced in an antibody-specific manner against transferrin receptor-expressing U-87 MG cells. This information would be valuable in the development of antibody-modified LNPs for cell-selective targeting.

The Complex World of Kynurenic Acid: Reflections on Biological Issues and Therapeutic Strategy.

It has been unequivocally established that kynurenic acid has a number of actions in a variety of cells and tissues, raising, in principle, the possibility of targeting its generation, metabolism or sites of action to manipulate those effects to a beneficial therapeutic end. However, many basic aspects of the biology of kynurenic acid remain unclear, potentially leading to some confusion and misinterpretations of data. They include questions of the source, generation, targets, enzyme expression, endogenous concentrations and sites of action. This essay is intended to raise and discuss many of these aspects as a source of reference for more balanced discussion. Those issues are followed by examples of situations in which modulating and correcting kynurenic acid production or activity could bring significant therapeutic benefit, including neurological and psychiatric conditions, inflammatory diseases and cell protection. More information is required to obtain a clear overall view of the pharmacological environment relevant to kynurenic acid, especially with respect to the active concentrations of kynurenine metabolites in vivo and changed levels in disease. The data and ideas presented here should permit a greater confidence in appreciating the sites of action and interaction of kynurenic acid under different local conditions and pathologies, enhancing our understanding of kynurenic acid itself and the many clinical conditions in which manipulating its pharmacology could be of clinical value.

Exploring the potential mechanisms of the ethyl acetate fraction of Hippophae rhamnoides L. seeds as a natural healing agent for wound repair

Ethnopharmacological relevanceSea buckthorn (Hippophae rhamnoides L.) has been designated a "medicine food homology" fruit by the National Health Commission of China due to its nutritional value. In traditional Chinese ethnomedicine, Hippophae rhamnoides L. is commonly used to treat nonhealing wounds such as burns, sores, and gastric ulcers. The aim of this study was to explore the healing effects of the ethyl acetate extract of sea buckthorn seeds (SBS-EF) on burn wounds. Aim of the studyThe primary objectives of this research were to determine the most effective medicinal site of action for treating burns with sea buckthorn seeds (SBS) and to investigate the underlying material basis and mechanisms of their therapeutic effects. Materials and methodsThe effects of different components of SBS-EF on the proliferation and migration of human skin fibroblasts (HSFs) were evaluated via MTT assays, scratch assays, transwell assays, and hydroxyproline secretion analysis. SBS-EF displayed the greatest activity amongst the extracts. Subsequent analyses included network pharmacology methodology, molecular docking studies, ultraperformance liquid chromatography UPLC-Orbitrap-Exploris-120-MS and a severe second-degree burn rat model to investigate the chemical constituents and potential therapeutic mechanisms of the SBS-EF. ResultsIn vitro studies demonstrated the efficacy of SBS-EF in promoting HSF growth and migration. UPLC-Orbitrap-Exploris-120-MS analysis revealed that SBS-EF had ten major constituents, with flavonoids being the predominant compounds, especially catechin, quercetin, and kaempferol derivatives. Network pharmacology and molecular docking analyses indicated that SBS-EF may exert its healing effects by modulating the Wnt/β-catenin signalling pathway. Subsequent in vivo experiments demonstrated that SBS-EF accelerated burn wound healing in rats, increased hydroxyproline expression in skin tissue, facilitated skin structure repair, and enhanced collagen production and organisation over a 21 d period. Additionally, exposure to SBS-EF upregulated WNT3a and β-catenin while downregulating GSK-3β levels in rat skin tissue. ConclusionsThe wound healing properties of SBS-EF were attributed to its ability to enhance HSF growth and migration, increase hydroxyproline levels in the skin, promote collagen accumulation, reduce scarring, and decrease the skin water content. SBS-EF may also provide therapeutic benefits for burns by modulating the Wnt/β-catenin signalling pathway, as evidenced by its effective site and likely mechanism of action in the treatment of burned rats.

Melittin protects against neural cell damage in rats following ischemic stroke

ObjectiveIn this study, we explored the neuroprotective effect of melittin (MEL) after brain ischemia using a rat model. MethodsThe rats underwent middle cerebral artery occlusion (MCAO) for 60 min and were randomly divided into the control group, saline group, and MEL group. Rats in each group were injected intraperitoneally with MEL one day before MCAO until sacrificed. Morris water maze and rotation test were used to assess locomotor function and cognitive ability. The 9.4 Tesla MRI was used to scan and assess the infarct volume of the rat brains. Immunohistochemistry was used to detect the sites of action of MEL on microglia. Western blot and ELISA were used to measure the effect of MEL on the production of pro-inflammatory cytokines. The effect of MEL on neuronal cell apoptosis was observed by flow cytometry. ResultsCompared with the saline group, MEL treatment significantly increased the density of neurons in the cerebral cortical and reduced the cerebral infarct size after MCAO (33.9 ± 8.8% vs. 15.8 ± 3.9%, P < 0.05). Meanwhile, the time for MEL-treated rats to complete the water maze task on the 11th day after MCAO was significantly shorter than that of rats in the saline group (P < 0.05). MEL treatment also prolonged the rotarod retention time on day 14 after MCAO. Immunohistochemistry analysis showed that MEL inhibited the activation of microglia and suppressed the expression of TNF-α, IL-6, and IL-1β in the brain after ischemia. MEL treatment resulted in a significant decrease in TLR4, MyD88, and NF-κB p65 levels in extracts from the ischemic cerebral cortex. Finally, MEL reduced neuronal apoptosis induced by ischemic stroke (P < 0.05). ConclusionMEL treatment promotes neurological function recovery after cerebral ischemia in rats. These effects are potentially mediated through anti-inflammatory and anti-apoptotic mechanisms.

Brain region-specific action of ketamine as a rapid antidepressant.

Ketamine has been found to have rapid and potent antidepressant activity. However, despite the ubiquitous brain expression of its molecular target, the N-methyl-d-aspartate receptor (NMDAR), it was not clear whether there is a selective, primary site for ketamine's antidepressant action. We found that ketamine injection in depressive-like mice specifically blocks NMDARs in lateral habenular (LHb) neurons, but not in hippocampal pyramidal neurons. This regional specificity depended on the use-dependent nature of ketamine as a channel blocker, local neural activity, and the extrasynaptic reservoir pool size of NMDARs. Activating hippocampal or inactivating LHb neurons swapped their ketamine sensitivity. Conditional knockout of NMDARs in the LHb occluded ketamine's antidepressant effects and blocked the systemic ketamine-induced elevation of serotonin and brain-derived neurotrophic factor in the hippocampus. This distinction of the primary versus secondary brain target(s) of ketamine should help with the design of more precise and efficient antidepressant treatments.

Sustained fentanyl exposure inhibits neuronal activity in dissociated striatal neuronal-glial cocultures through actions independent of opioid receptors.

Besides having high potency and efficacy at the µ-opioid (MOR) and other opioid receptor types, fentanyl has some affinity for some adrenergic receptor types, which may underlie its unique pathophysiological differences from typical opioids. To better understand the unique actions of fentanyl, we assessed the extent to which fentanyl alters striatal medium spiny neuron (MSN) activity via opioid receptors or α1-adrenoceptors in dopamine type 1 or type 2 receptor (D1 or D2)-expressing MSNs. In neuronal and mixed-glial cocultures from the striatum, acute fentanyl (100 nM) exposure decreased the frequency of spontaneous action potentials. Overnight exposure of cocultures to 100 nM fentanyl severely reduced the proportion of MSNs with spontaneous action potentials, which was unaffected by coexposure to the opioid receptor antagonist naloxone (10 µM) but fully negated by coadministering the pan-α1-adrenoceptor inverse agonist prazosin (100 nM) and partially reversed by the selective α1A-adrenoceptor antagonist RS 100329 (300 nM). Acute fentanyl (100 nM) exposure modestly reduced the frequency of action potentials and caused firing rate adaptations in D2, but not D1, MSNs. Prolonged (2-5 h) fentanyl (100 nM) application dramatically attenuated firing rates in both D1 and D2 MSNs. To identify possible cellular sites of α1-adrenoceptor action, α1-adrenoceptors were localized in subpopulations of striatal astroglia and neurons by immunocytochemistry and Adra1a mRNA by in situ hybridization in astrocytes. Thus, sustained fentanyl exposure can inhibit striatal MSN activity via a nonopioid receptor-dependent pathway, which may be modulated via complex actions in α1-adrenoceptor-expressing striatal neurons and/or glia.NEW & NOTEWORTHY Acute fentanyl exposure attenuated the activity of striatal medium spiny neurons (MSNs) in vitro and in dopamine D2, but not D1, receptor-expressing MSNs in ex vivo slices. By contrast, sustained fentanyl exposure suppressed the spontaneous activity of MSNs cocultured with glia through a nonopioid receptor-dependent mechanism modulated, in part, by α1-adrenoceptors. Fentanyl exposure can affect striatal function via a nonopioid receptor mechanism of action that appears mediated by α1-adrenoreceptor-expressing striatal neurons and/or astroglia.

Preserving Genome Integrity: Unveiling the Roles of ESCRT Machinery.

The endosomal sorting complex required for transport (ESCRT) machinery is composed of an articulated architecture of proteins that assemble at multiple cellular sites. The ESCRT machinery is involved in pathways that are pivotal for the physiology of the cell, including vesicle transport, cell division, and membrane repair. The subunits of the ESCRT I complex are mainly responsible for anchoring the machinery to the action site. The ESCRT II subunits function to bridge and recruit the ESCRT III subunits. The latter are responsible for finalizing operations that, independently of the action site, involve the repair and fusion of membrane edges. In this review, we report on the data related to the activity of the ESCRT machinery at two sites: the nuclear membrane and the midbody and the bridge linking cells in the final stages of cytokinesis. In these contexts, the machinery plays a significant role for the protection of genome integrity by contributing to the control of the abscission checkpoint and to nuclear envelope reorganization and correlated resilience. Consistently, several studies show how the dysfunction of the ESCRT machinery causes genome damage and is a codriver of pathologies, such as laminopathies and cancer.

Guided Plasma Application in Dentistry-An Alternative to Antibiotic Therapy.

Cold atmospheric plasma (CAP) is a promising alternative to antibiotics and chemical substances in dentistry that can reduce the risk of unwanted side effects and bacterial resistance. AmbiJet is a device that can ignite and deliver plasma directly to the site of action for maximum effectiveness. The aim of the study was to investigate its antimicrobial efficacy and the possible development of bacterial resistance. The antimicrobial effect of the plasma was tested under aerobic and anaerobic conditions on bacteria (five aerobic, three anaerobic (Gram +/-)) that are relevant in dentistry. The application times varied from 1 to 7 min. Possible bacterial resistance was evaluated by repeated plasma applications (10 times in 50 days). A possible increase in temperature was measured. Plasma effectively killed 106 seeded aerobic and anaerobic bacteria after an application time of 1 min per 10 mm2. Neither the development of resistance nor an increase in temperature above 40 °C was observed, so patient discomfort can be ruled out. The plasma treatment proved to be effective under anaerobic conditions, so the influence of ROS can be questioned. Our results show that AmbiJet efficiently eliminates pathogenic oral bacteria. Therefore, it can be advocated for clinical therapeutic use.

Efficacy, crop response, and economics of alternatives to glyphosate for pre‐plant weed control in small grains

AbstractThe value of glyphosate to growers practicing minimum or no‐till farming has been primarily a function of three factors: broad‐spectrum weed control, little to no carryover effect, and cost effectiveness. A 2‐year field study was conducted in 2021 and 2022 at the University of Idaho Research and Extension Centers at Kimberly and Aberdeen, ID, to evaluate the efficacy of alternative pre‐plant burndown herbicide treatments as compared to glyphosate treatment, the industry standard in small grain production systems. Herbicide cost comparison and crop injury observation were also conducted. Most herbicide treatments provided 90% control of the predominant weed species at 3 weeks after herbicide application. At least six different herbicide treatments had an equivalent cost to that of glyphosate at $26.50 ha−1. No observable damage from herbicide treatments was observed and crop yield was not affected by the treatments. These factors indicate that there are alternatives to pre‐plant burndown herbicides that are equally effective as glyphosate. With combinations of herbicides, each having a different site of action, weed control can be achieved while simultaneously reducing the risk of herbicide resistance.

Abstract Tu083: Oxytocin improves cardiovascular outcomes in a rat model of pressure-overload heart failure

Oxytocin (OT) is a peptide made in the hypothalamus and released into circulation by the pituitary gland. Known for its role in childbirth and lactation, recent research suggests that OT has significant cardiovascular benefits, reducing the risk of cardiovascular diseases such as hypertension and atherosclerosis. We tested if OT has beneficial effects on cardiovascular function in a rat model of pressure overload heart failure (HF). Neonatal Sprague Dawley rats underwent transaortic constriction (TAC). Pressure overload and cardiac dysfunction progressed as animals matured. Echocardiography at 5 weeks of age confirmed reduced ejection fraction. Animals were then randomly assigned to receive daily IP injections of either OT (treatment) or saline (control) for two weeks. Echocardiography was performed again before hearts were excised for optical mapping studies to test for electrophysiological differences between groups. Hearts were electromechanically uncoupled using blebbistatin and transmembrane potential (RH237) and intracellular Ca2+ (Rhod2am) were simultaneously mapped during a dynamic restitution protocol. Preliminary results indicate that rats in the treatment (OT, n=3) group had improved cardiac function compared to controls (saline, n=3), with higher ejection fraction (66.71 ± 9.44 vs. 25.83 ± 17.93, p=0.0125), higher cardiac output (62.4 ± 11.45 vs. 20.35 ± 6.12, p=0.0025), and greater stroke volume (180.2 ± 18.19 vs. 73.96 ± 37.29, p=0.0057). Preliminary optical mapping results indicate that the hearts of OT-treated rats (n=3) have lower steady state action potential duration (APD) compared to controls (n=2). APD60 decreased from 109.5 ± 10.09 to 75.79 ± 21.94 (p=.0725) and APD80 decreased from 133.1 ± 10.22 to 101.1 ± 24.5 (p=.09595), indicating preservation of repolarizing currents corresponding to healthier electrophysiological function. In summary, our preliminary results suggest exogenous IP OT administration could have a potent cardioprotective effect on chronic and severe pressure overload hearts. Future work will investigate potential mechanisms of OT mediated cardio-protection, including sites of action.