Journal of Pharmacology and Experimental Therapeutics最新文献

Kidney diseases represent one of the most prevalent and rapidly growing global health burdens, with rising mortality linked to both acute kidney injury and chronic kidney disease (CKD). Despite the increasing incidence of CKD affecting 8%-16% of the world's population, therapeutic options remain limited, largely because of an incomplete understanding of underlying pathophysiology and the lack of reliable biomarkers. Recent evidence highlights that free-fatty acids (FFA), particularly short-chain and long-chain fatty acids, are beneficial modulators of renal health, associated with reduced CKD risk and slower kidney function decline. Although effects of FFA have historically been linked to their intracellular activity, they can also engage a family of cell-surface G protein-coupled FFA receptors (FFAR), including FFARs FFA2/GPR43 and FFA3/GPR41, which are activated by short-chain fatty acids, and FFA1/GPR40 and FFA4/GPR120, which are agonized by long-chain fatty acids. This review summarizes current knowledge of FFAR-mediated mechanisms in acute kidney injury, CKD, and associated renal pathologies, emphasizing their potential as therapeutic targets to improve kidney outcomes. We also discuss the therapeutic relevance of dietary FFA related to these FFAR in relation to renal disease. SIGNIFICANCE STATEMENT: Fatty acid sensing G protein-coupled receptors have emerged as important regulators of renal inflammation, fibrosis, and tubular survival across acute and chronic models of kidney injury. This review synthesizes current evidence for short- and long-chain free-fatty acid receptors in kidney disease, highlights translational relevance, and outlines challenges that must be addressed to advance free-fatty acid receptor-targeted therapies.

Long-term proton pump inhibitor use is associated with cognitive and motor impairments and nutrient deficiencies. Whether these impairments result directly from proton pump inhibitors or indirectly from nutrient deficiencies remains unclear. Chronic pantoprazole treatment (0 or vehicle, 1, 10, or 100 mg/kg/day, by mouth, 38 days) was evaluated across tests of anxiety-like behavior, learning and memory behavior, and motor function and coordination in 4-month-old male C57BL/6 mice. Serum levels of holotranscobalamin and magnesium, as well as poly(A) RNA sequencing of brain tissue, were subsequently evaluated. Pantoprazole (100 mg/kg) reduced the percentage of spontaneous alternations in the Y-maze (P < .05 vs 0 and 1 mg/kg) and decreased the distance traveled in Rotarod testing (P < .05 vs vehicle), suggesting that it impaired short-term working memory behavior and motor coordination, respectively. All pantoprazole doses increased anxiety-like behavior in the open field (P < .05 vs vehicle). In novel (N) object recognition testing, pantoprazole (1 mg/kg) reduced the discrimination index at 24 hours (P < .05, vs vehicle), suggesting it impaired recognition memory behavior. Magnesium levels were similar across chronic pantoprazole groups. Holotranscobalamin, the bioavailable form of vitamin B₁₂, was lower at 10 mg/kg pantoprazole (P < .05 vs vehicle). Poly(A) RNA sequencing identified 15 differentially expressed genes in hippocampus (10 upregulated and 5 downregulated) and 32 in FC (14 upregulated and 18 downregulated) with 100 mg/kg pantoprazole treatment compared to vehicle. There was no correspondence between behavioral changes and alterations in serum nutrient levels with the respective doses of pantoprazole. SIGNIFICANCE STATEMENT: Long-term proton pump inhibitor use may affect cognition, motor function, and nutrient status. This study examined the behavioral impact of chronic pantoprazole treatment in young male mice and whether declines in serum magnesium or holotranscobalamin levels could explain behavioral changes. Doses of chronic pantoprazole that altered behavior were not associated with declines in either nutrient.

Previous studies demonstrated that CNS4, a glutamate concentration biased N-methyl-D-aspartate receptor modulator, produces central analgesic and stress mitigating effects in mice. To translate these findings to a nonrodent species, we evaluated the pharmacokinetics (PK) and safety of CNS4 in 21 adult beagle dogs. A custom formulation was developed for subcutaneous (SC) delivery, and an initial 2 dose PK study (5 and 10 mg/kg) was conducted. CNS4 achieved rapid absorption, with T_max values of 1.50 ± 0.87 hour (5 mg/kg) and 1.67 ± 0.58 hour (10 mg/kg). Pharmacokinetics were comparable across the limited doses studied, and apparent volumes of distribution for the extravascular route were 33.5 ± 12.5 and 25.6 ± 3.67 L/kg, respectively. To assess oral feasibility, a 50 mg/kg dose of CNS4 suspended in 0.5% carboxymethyl cellulose was first tested in mice and then in dogs. Oral administration in dogs resulted in rapid absorption, with a T_max of ∼1 hour, comparable to the SC route. Systemic tolerability was assessed in an acute toxicity study involving 4 groups (vehicle, 5, 10, and 25 mg/kg SC) of dogs. No changes in behavior, food intake, or body weight were observed over 14 days. Hematology, lipid panels, and electrolyte measurements collected on days 0 (predose), 7, and 14 revealed no significant CNS4 related abnormalities. Together, these findings demonstrate that CNS4 has an acceptable safety profile and predictable PK across SC and oral administration routes in dogs. This first-in-dog evaluation supports further development of CNS4 as a potential non opioid analgesic and stress mitigating therapeutic agent. SIGNIFICANCE STATEMENT: N-methyl-D-aspartate receptor subtypes are attractive therapeutic targets for chronic pain and post-traumatic stress disorder because of their critical role in emotional memory formation. This translational pharmacology study demonstrates the safety and predictable pharmacokinetics of a centrally acting analgesic and stress mitigating N-methyl-D-aspartate receptor modulator (CNS4) in dogs after single dose subcutaneous and oral administration.

Preclinical studies indicate that blocking diacylglycerol kinase (DGK) family members DGKα or DGKζ can improve antitumor immunity, prompting the development of clinical-stage, potent and selective small molecule inhibitors of DGKα and/or DGKζ. DGKα and DGKζ are the most widely expressed DGK family members by immune cells, and both enzymes convert the signaling lipid diacylglycerol (DAG) to phosphatidic acid. DAG is a critical second messenger downstream of T cell receptor (TCR) stimulation that promotes activation and effector function. Blocking DGKα or DGKζ activity enhances DAG-mediated signaling, potentiating immune cell activity. Because DGKα and DGKζ functionally overlap, we sought to compare the effects of pharmacological inhibition strategies targeting DGKα or DGKζ individually or simultaneously (DGKα/ζ) to determine which approach maximized immune cell activation. Evaluation of TCR downstream signaling using primary human and mouse cells revealed that dual DGKα/ζ inhibition promoted the greatest increase in cellular activity, including antigen-dependent cytokine production and tumor cell killing. In contrast, pharmacological inhibition of DGKζ alone had modest effects, and inhibition of DGKα alone had minimal bearing on TCR-mediated activity. Notably, loss of DGKα and DGKζ protein was observed following inhibitor treatment and may point to an additional mechanism of action for DGK targeting small molecule inhibitors. Finally, analysis of biopsies from patients with nonsmall cell lung cancer showed that tumor infiltrating lymphocytes expressed both DGKα and DGKζ and exhibited increased activation and cytokine production ex vivo upon DGKα/ζ coinhibition in conjunction with TCR stimulation, indicating that tumor infiltrating lymphocytes are sensitive to DGKα/ζ coinhibition. SIGNIFICANCE STATEMENT: This work directly compares pharmacological inhibition of DGKα and DGKζ, affirming that DGKα/ζ coinhibition is required to maximally increase TCR responses. Importantly, DGKα/ζ inhibition increased activation and cytokine production in both healthy T cells and tumor infiltrating lymphocytes.

Steady-state volume of distribution can be predicted using tissue-to-plasma partition coefficients (K_p) and tissue volumes. K_p values are important components of physiologically based pharmacokinetic models, allowing for estimation of distribution kinetics and simulation of concentration-time profiles. Many in silico approaches have been developed to predict tissue K_p values based on physicochemical processes that govern drug distribution. However, these methods frequently overpredict or underpredict tissue K_p values, highlighting the need to consider additional mechanisms that can impact drug distribution kinetics. Many drugs have been shown to bind to rat and human fatty acid binding proteins (FABPs) in vitro but the impact of this binding to drug distribution has not been incorporated into K_p predictions. We hypothesized that incorporating intracellular protein binding into tissue K_p predictions will improve K_p prediction accuracy. Using liver as a model organ, 4 physiologically based dynamic liver distribution models (LDMs) were developed to assess the role of distribution processes in K_p predictions. The developed LDMs incorporated known distribution mechanisms and intracellular drug binding to liver FABP (FABP1). The liver K_p values for drugs that bind to FABP1 were accurately predicted using the LDM that incorporates lipid partitioning, albumin distribution, and FABP1 binding but not using LDMs without FABP1 binding. Human FABP1 expression was quantified in 61 human livers and the interindividual variability in tissue FABP1 binding was incorporated into tissue K_p predictions. These simulations showed that intracellular FABP1 binding can cause interindividual variability in K_p values and result in higher cytosolic drug concentrations. SIGNIFICANCE STATEMENT: This study shows that incorporating intracellular protein binding such as binding to fatty acid binding protein 1 into tissue K_p predictions improves accuracy of the predictions. The novel dynamic liver distribution model can be extrapolated to other organs of interest and integrated into full-body physiologically based pharmacokinetic models to predict drug distribution kinetics. With dynamic and saturable distribution mechanisms incorporated into a physiologically based pharmacokinetic model, nonlinear distribution kinetics can be simulated for various drugs.

Cannabigerol (CBG) is a nonintoxicating phytocannabinoid gaining popularity as a self-medication for anxiety and other conditions; however, its pharmacological properties remain poorly defined. Here, we report the development of a rapid and sensitive liquid chromatography-tandem mass spectrometry method for quantifying CBG and its primary oxidative metabolite, cyclo-CBG. This platform enabled the characterization of CBG's pharmacokinetic and biotransformation profile after intraperitoneal administration (10 mg/kg) in male mice. CBG exhibited rapid systemic distribution and clearance, with relatively low brain penetration (brain-to-plasma ratio = 0.26). In contrast, cyclo-CBG accumulated in brain tissue to a surprising extent (brain-to-plasma ratio = 7.1), suggesting local formation and a potentially important role in mediating central effects. Despite prior reports of anxiolytic effects, we found that CBG administered at its peak brain concentration produced anxiogenic-like effects in mice, as assessed using the elevated plus maze. This response was not affected by the CB₁ cannabinoid receptor inverse agonist, rimonabant (3 mg/kg, i.p.), indicating a mechanism independent of CB₁ signaling. As interest in CBG continues to rise, the analytical and pharmacokinetic framework presented here provides a valuable foundation for advancing preclinical and clinical investigations into its efficacy, safety, and mechanism of action. SIGNIFICANCE STATEMENT: Application of a new liquid chromatography-tandem mass spectrometry method to quantify cannabigerol reveals key pharmacokinetic properties of this phytocannabinoid in mice, including unexpectedly high brain accumulation of its metabolite cyclo-cannabigerol, which was accompanied by anxiogenic-like effects. The results offer valuable tools for advancing preclinical and clinical investigations into cannabigerol pharmacology.

Opioids that act at the mu-opioid receptor (MOR) are the gold standard for pain management, but can induce serious unwanted effects, including addiction liability and respiratory depression. 2-(3-bromo-4-methoxyphenyl)-3-[(4-chlorophenyl) sulfonyl]-thiazolidine is a positive allosteric modulator of MOR that increases the actions of small-molecule opioids and opioid peptides in vitro. In vivo, 2-(3-bromo-4-methoxyphenyl)-3-[(4-chlorophenyl) sulfonyl]-thiazolidine enhances the action of endogenously released opioid peptides to provide MOR-mediated antinociception, but not constipation, reward, or respiratory depression. However, the effects of positive allosteric modulators of MOR on the behavioral actions of opioid drugs such as morphine and fentanyl have not been studied. Here, we show that 2-(3-bromo-4-methoxyphenyl)-3-[(4-chlorophenyl) sulfonyl]-thiazolidine enhances opioid drug-induced antinociception in assays for acute and inflammatory pain but not the adverse effects of constipation, respiratory depression measured by blood oxygen levels and respiration rate, or reward as determined by conditioned place preference. These data support the potential of positive allosteric modulators of MOR as effective and safe opioid-sparing agents for pain management. SIGNIFICANCE STATEMENT: The undertreatment of pain and the addiction liability of opioids necessitate new strategies to improve pain management. Here, we demonstrate that the mu-opioid receptor modulator 2-(3-bromo-4-methoxyphenyl)-3-[(4-chlorophenyl) sulfonyl]-thiazolidine enhances opioid drug-mediated analgesia in mice without enhancing constipation, reward, or respiratory depression.