Journal of Pharmacology and Experimental Therapeutics最新文献

The opioid antagonists, naloxone and nalmefene, are used clinically to rapidly reverse opioid overdose, but often precipitate withdrawal symptoms in opioid-dependent individuals. This study compared 2 medications used for opioid use disorder, buprenorphine and methadone, to naloxone for reversing fentanyl-induced effects in rats. Buprenorphine alone did not produce significant respiratory depression at 0.5-5.0 mg/kg. Rats were challenged with 0.1 mg/kg fentanyl, which resulted in a significant reduction in oxygen saturation (SpO₂), and naloxone 0.1 mg/kg, buprenorphine 3.0 mg/kg, methadone 2.25 mg/kg, or saline control was given to reverse fentanyl effects. Antinociception and SpO₂ were restored to baseline by 15 minutes after administration of naloxone and buprenorphine. The saline group showed a slow return to baseline SpO₂ within 30 minutes, whereas methadone extended the duration of, but did not enhance, the effects of fentanyl. To determine whether buprenorphine could rapidly (within minutes) reverse fentanyl-induced respiratory depression, rats were given a dose of fentanyl 0.1 mg/kg s.c., followed by saline, naloxone 0.1 mg/kg, or buprenorphine 3.0 mg/kg, and SpO₂ was monitored continuously for 10 minutes. Both naloxone and buprenorphine reversed fentanyl effects within 3.5 minutes, whereas the saline group did not return to baseline levels during the monitoring period. Buprenorphine at 0.3 and 1.0 mg/kg also reversed fentanyl effects, with a slower onset of reversal. In a follow-up study, rats received fentanyl followed by saline, buprenorphine, or methadone for reversal, and blood and brain levels were measured. Fentanyl concentration in the brain was not significantly affected by methadone and buprenorphine treatment, suggesting that differences in SpO₂ were not attributable to pharmacokinetic interactions. These data support repurposing buprenorphine for the treatment of opioid overdose. SIGNIFICANCE STATEMENT: Opioid overdoses cause ∼80,000 annual deaths in the United States. Buprenorphine is an opioid partial agonist used for opioid use disorder. This study used a rat model to compare buprenorphine to naloxone for efficacy in reversing fentanyl-induced respiratory depression.

Cocaine-associated stimuli acquire conditioned reinforcing effects and can precipitate relapse. We used the New Response Acquisition procedure to examine factors that influenced the conditioned reinforcing effects of cocaine-associated stimuli in rats. According to this procedure, rats first experienced Pavlovian conditioning, during which they were exposed to intravenous cocaine deliveries and stimulus (light + white noise) presentations. After Pavlovian conditioning, animals learned to respond to the cocaine-paired stimulus alone. The number of responses made for that stimulus reflected the conditioned reinforcing effects of the cocaine-associated stimulus. Across 3 experiments, the extent to which the dose of cocaine during Pavlovian conditioning (experiment 1), food restriction (experiment 2), and the number of cocaine-stimulus pairings and the number of days of Pavlovian conditioning (experiment 3) led to different conditioned reinforcing effects of the cocaine-associated stimulus. Taken together, we found that cocaine-associated cues took on conditioned reinforcing effects dose-dependently, were augmented by food restriction, and were most robust following 10 days of Pavlovian conditioning relative to 5 days of conditioning. These findings advance our understanding of the conditions under which cocaine-associated stimuli can act as a conditioned reinforcer. SIGNIFICANCE STATEMENT: Cocaine-associated stimuli acquire conditioned reinforcing effects via Pavlovian conditioning that drive drug-seeking and relapse. Understanding the conditions under which cocaine-associated stimuli take on conditioned reinforcing effects can be used to inform efforts to curtail cocaine use disorder.

γ-aminobutyric acid type-A receptors associate with auxiliary proteins such as Shisa7 and have allosteric binding sites for benzodiazepines, barbiturates, and alcohols. In this study, Shisa7 was knocked down to assess its involvement in the discriminative-stimulus effects of drugs from each class and in the positive reinforcing effects of alcohol. Twelve male Long-Evans rats were trained to respond in a drug-discrimination procedure with 6 trained to discriminate ethanol (1 g/kg) from saline and 6 trained to discriminate alprazolam (1.8 mg/kg) from cyclodextrin. Following training, cumulative dose-effect curves for ethanol, alprazolam, and pentobarbital were established before and after Shisa7 knockdown was achieved using an intravenous dicer substrate small-interfering ribonucleic acid. A separate group of 6 rats was also trained to consume ethanol orally to assess ethanol intake before and after Shisa7 knockdown. In general, before Shisa7 knockdown, alprazolam and pentobarbital partially substituted for ethanol in ethanol-trained subjects up to doses that decreased response rate, whereas pentobarbital, but not ethanol, partially substituted for alprazolam in alprazolam-trained subjects. After Shisa7 knockdown, the dose-effect curve for ethanol-lever responding in ethanol-trained subjects was shifted downward, the curve for alprazolam-lever responding in alprazolam-trained subjects was shifted rightward, and the curve for pentobarbital was shifted rightward in both ethanol- and alprazolam-trained subjects. Shisa7 knockdown did not affect response rates. In rats orally consuming ethanol, both ethanol intake and dose were significantly decreased after Shisa7 knockdown compared with the dicer substrate small-interfering ribonucleic acid control. These findings demonstrate that reducing Shisa7 levels attenuated the discriminative-stimulus effects of 3 positive allosteric modulators of γ-aminobutyric acid type-A receptors and decreased ethanol's reinforcing effects. SIGNIFICANCE STATEMENT: This study demonstrates that Shisa7, an auxiliary protein associated with γ-aminobutyric acid type-A receptor, plays a crucial role in mediating the discriminative-stimulus effects of ethanol, alprazolam, and pentobarbital, as well as the reinforcing effects of ethanol. By demonstrating that Shisa7 knockdown attenuates the behavioral effects of these drugs, the findings provide new insights into the molecular mechanisms underlying γ-aminobutyric acid type-A receptor-mediated drug effects and potentially identify Shisa7 as a key modulatory mechanism through which these drugs produce their effects.

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder characterized by hyperandrogenism and frequently associated with insulin resistance (IR), a key pathogenic factor in PCOS. However, insulin sensitizers commonly used to treat PCOS are often recommended off-label and may cause side effects. This study investigated the therapeutic effects of pancreastatin inhibitor 8 (PSTi8), an insulin sensitizer, in a PCOS rat model. The PCOS rat model was established by daily feeding with a high-fat diet and administering subcutaneous injections of dehydroepiandrosterone at a dose of 60 mg/kg body weight for 21 days and further, followed by 21 days of treatment with PSTi8 (10 mg/kg) and metformin (300 mg/kg). Body weight, estrous cycle, glucose, and insulin tolerance test results were monitored. Ovarian morphology, estrous cycle changes, oxidative stress and inflammatory markers, steroidogenic hormone levels and protein expression, and insulin signaling pathway were assessed to evaluate the therapeutic effectiveness of PSTi8 in PCOS rats. This study found that PSTi8 improved IR and reduced body weight in PCOS rats. PSTi8 lowered serum levels of insulin (27%), testosterone (56%), estradiol (2-fold), progesterone (21%), sex hormone-binding globulin (7.5%), and luteinizing hormone/follicle stimulating hormone ratio (57%). Additionally, PSTi8 helped to restore ovarian morphology, estrous cycle, and improve dyslipidemia. PSTi8 treatment also reduces the oxidative stress level of total superoxide ismutase (16%), glutathione peroxidase (26%), and inflammation in PCOS rats. Furthermore, PSTi8 restores the steroidogenic protein expression and increases PI3K/Akt phosphorylation in PCOS rats. These findings demonstrate PSTi8 exhibited comparable efficacy to metformin in ameliorating IR and ovarian dysfunction in the studied PCOS model. SIGNIFICANCE STATEMENT: Polycystic ovary syndrome (PCOS) increases risk of reproductive and metabolic disorders, partly due to systemic inflammation. This study combined dehydroepiandrosterone with high-fat diet and successfully induced PCOS-like features in rats. PSTi8, a pancreastatin inhibitor known for insulin-sensitizing effects in various disease models, effectively reversed PCOS-associated pathophysiology. PSTi8 improves insulin sensitivity by activating the PI3K/AKT signaling pathway and ameliorates oxidative stress and inflammation in PCOS rats. Additionally, PSTi8 treatment normalized steroidogenesis protein expression and reduced circulating biomarkers linked to cardiovascular risk.

Exosomes are a category of extracellular vesicles with a 30-150 nm diameter that serve as carriers of distinct and functional biomolecules, such as lipids, nucleic acids, and proteins. They are released by almost all types of cells and mirror the characteristics of their originating cells, making them appealing for use in cell-free therapeutic applications. The skin is the largest organ of the body. It protects the entire body from the harsh environment, helps to maintain body temperature, supports life for all other body parts, plays a significant role in regulating the immune system, etc. Interventions in dermatology and cosmetology help to maintain good-looking and healthy skin. Exosomes have assumed a prominent position in cosmetics and dermatology by facilitating cellular regeneration. Recent studies have highlighted the efficacy of exosomes as effective antioxidants in therapy approaches such as hair regeneration, skin aging reversal, scar prevention, wound healing, dermatological diseases. This article explores the therapeutic applications and clinical interventions of exosomes in cosmetology and dermatology. It also discusses the challenges and prospects in the field. SIGNIFICANCE STATEMENT: Cell-free therapy using exosomes is an emerging area in disease management. Exosomes, nanosized extracellular vesicles, play a prominent role in various conditions such as hair growth and regeneration, reversal of aging, wound healing, and management of many skin-associated diseases, such as psoriasis, dermatitis, etc. This review describes the recent developments in the utilization of exosomes in dermatological and cosmetological treatment aspects, their regulatory issues, and current status of clinical trials.

Sleep disturbances are prominent symptoms of opioid withdrawal that contribute to relapse in individuals with opioid use disorder (OUD). Although preclinical studies often examine protracted withdrawal after sustained abstinence, few address the repeated, spontaneous withdrawal cycles that model human patterns of use. Moreover, targeting sleep disruptions provides a novel strategy to reduce relapse risk. The present studies characterized the effects of repeated spontaneous daily withdrawal on sleep and quantitative electroencephalography (qEEG) after once-daily morphine administration in male Sprague-Dawley rats. Daily withdrawal produced persistent sleep disruptions, including reduced rapid eye movement (REM) and non-REM sleep, increased time awake, and sleep fragmentation. Notably, tolerance did not develop to the acute pharmacological effects of morphine or spontaneous daily withdrawal effects on sleep across the 30-day study. Relative spectral analysis (qEEG) revealed progressive shifts from low (δ) to high (γ) frequency power across withdrawal phases, with significant and persistent increases in wake and non-REM relative γ band power during later stages of daily and protracted withdrawal. There were few correlations between somatic behavioral signs and sleep or qEEG supporting our hypothesis that sleep, and brain activity disturbances represent distinct withdrawal phenotypes that should be studied and treated separately from somatic withdrawal behaviors. Together, these findings highlight the chronic and multifaceted nature of opioid withdrawal, particularly its effect on disrupted sleep and brain activity. Collectively, these studies characterized a translationally relevant preclinical model incorporating both sleep and qEEG as potential behavioral and physiological biomarkers for evaluating putative pharmacotherapies for withdrawal-related sleep dysfunction in OUD. SIGNIFICANCE STATEMENT: Sleep disruptions associated with withdrawal in opioid use disorder represent a contributing factor for relapse yet lack targeted treatments. This study reports consistent, spontaneous daily sleep disruptions in rats after once-daily morphine administration, providing a model that can be used for treatment development.

Nonviral DNA delivery has emerged as a promising alternative to viral vectors for gene therapy because of its reduced immunogenicity, scalable manufacturing, and capability of loading larger cargos. Despite these advantages, multiple hurdles must be addressed. The endosomal barrier poses a significant obstacle because DNA is often degraded in acidic vesicles following endocytosis. After endosomal release, DNA is sensed by the cyclic GMP-AMP synthase, a cytosolic immune sensor, leading to inflammation and lower gene expression levels. Furthermore, DNA requires nuclear entry for gene expression, which has been one of the most complex challenges for the field to progress. Recent advances have explored innovative strategies to overcome these hurdles for nonviral DNA delivery. This review highlights the current landscape of nonviral DNA delivery, focusing on intracellular barriers and recent technological breakthroughs. We further discuss future directions to overcome these challenges to develop safe, effective, and clinically translatable nonviral DNA delivery systems for a range of therapeutic applications. SIGNIFICANCE STATEMENT: Nonviral DNA delivery offers a safer, scalable alternative to viral vectors but faces key challenges such as endosomal escape, poor tolerability, and low levels of transgene expression. This review highlights the critical barriers and emerging solutions, outlining how recent advances can enable low-cost, redosable genetic medicine and DNA vaccines suited for clinical translation.

Recent advances in immuno-oncology have led to the development of innovative T cell-engaging therapies, transforming the treatment landscape for hematologic and solid malignancies. Bispecific T cell engagers (BiTEs) have demonstrated clinical efficacy by redirecting T cell cytotoxicity toward tumor cells, yet challenges such as antigen escape, safety concerns, and limited durability remain. Building on the foundation established by BiTEs, the emergence of trispecific T cell engagers promises enhanced tumor selectivity, improved pharmacodynamic profiles, and potentially superior clinical outcomes. This minireview summarizes the pharmacology of T cell engagers, with a focus on the mechanistic evolution from BiTEs to next-generation trispecific antibodies. We highlight recent advances in molecular design, summarize current clinical evidence, and address ongoing challenges in drug development and safety. By critically synthesizing the latest preclinical and clinical findings, this review aims to inform future research directions and optimize the clinical translation of next-generation T cell-engaging therapeutics. SIGNIFICANCE STATEMENT: This minireview synthesizes current knowledge on the pharmacology of T cell engagers, spotlighting the shift from bispecifics to trispecifics, and provides insights essential for advancing safer and more effective immunotherapies in oncology.

Previous studies show that endothelin-converting enzyme 2 (ECE2), an enzyme involved in nonclassical processing of neuropeptide precursors, regulates the rate and extent of μ and δ opioid receptor recycling, but not internalization following activation by select synthetic and endogenous peptidic agonists. This study focuses on κ opioid receptors (KORs) and examines how prodynorphin and proenkephalin-derived peptides that are substrates of ECE2 modulate the internalization and recycling of both KOR and ECE2; as controls we use peptides that are not ECE2 substrates. First, we use a proximity-based ligation assay to show that KOR and ECE2 are in close proximity to directly interact and cointernalize. Treatment with the peptides induces internalization and recycling of ECE2 at a rate and extent comparable to that of KOR with longer opioid peptides inducing fast and robust internalization and recycling of both ECE2 and KOR compared with shorter peptides. We find that in recombinant cell lines and naïve cells expressing endogenous receptors, a small molecule ECE2 inhibitor attenuates KOR recycling as well as signaling by only peptides that are ECE2 substrates. Taken with the differential expression of ECE2 in the brain (relatively high expression in midbrain and dentate gyrus of the hippocampus and low expression in the striatum), these results highlight a pivotal role for ECE2 in differentially modulating KOR function. SIGNIFICANCE STATEMENT: This study highlights a role for endothelin-converting enzyme 2 in agonist mediated regulation of κ opioid receptor function by select prodynorphin and proenkephalin-derived peptides. Collectively, studies by authors suggest that endothelin-converting enzyme 2 inhibitors could be developed as therapeutics for pathologies involving dysregulations in κ opioid receptor signaling.

Sulfur is clinically used for treating scabies and pruritus and shows potential in treating atopic dermatitis (AD), though its mechanism remains unclear. The potential targets of sulfur and the differentially expressed genes of AD in the GSE237920 and GSE121212 datasets from the Gene Expression Omnibus database were identified. The intersecting genes were analyzed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. A protein-protein interaction network was established using the Search Tool for the Retrieval of Interacting Genes/Proteins database. Through Least Absolute Shrinkage and Selection Operator, Random Forest, and Support Vector Machine-Recursive Feature Elimination algorithms, we screened the core targets. The core genes were validated using receiver operating characteristic analysis, gene set enrichment analysis, and immune cell infiltration analysis. Long noncoding RNA (lncRNA)-microRNA (miRNA)-mRNA bioinformatics networks were predicted using databases. The core lncRNA-miRNA-mRNA axis was identified by intersecting bioinformatics networks with GSE168694. Subsequently, the expression of each node in the axis was verified through animal experiments. Using machine learning and bioinformatics analysis, glucose-6-phosphate isomerase (GPI) was identified as a core target. We then predicted 5 miRNAs and 141 lncRNAs. By validating the results using the GSE168694 dataset, the AC010336.1/miR-3929/GPI axis was identified as the key competing endogenous RNA regulatory axis. Animal experiments demonstrated that sulfur exerted therapeutic effects against AD by restoring epidermal barrier function, reducing immune cell infiltration, and mitigating pruritus. Additionally, animal experiments confirmed that sulfur alleviated AD by modulating the AC010336.1/miR-3929/GPI axis. These novel findings provide valuable insights and guidance for future investigations on the competing endogenous RNA mechanism of traditional Chinese medicine in AD therapy. SIGNIFICANCE STATEMENT: This study investigates the therapeutic mechanisms of sulfur, a traditional Chinese medicine, in the treatment of atopic dermatitis, with elucidate extending to the single-gene regulatory level.