The Journal of Pharmacology and Experimental Therapeutics

Dysregulated expression and activity of DYRK1A, dual specificity tyrosine phosphorylation regulated kinase 1A, is a feature of several neurodevelopmental and neurodegenerative diseases, including Down syndrome, DYRK1A syndrome, autism spectrum disorders, Alzheimers disease, and Parkinsons disease. Thus, manipulating DYRK1A activity in the brain has emerged as a potential therapeutic target for neurological disorders. Several DYRK1A inhibitors have shown promise for improving cognition in rodent models of Down syndrome and Alzheimers disease, for example, but the ability to affect DYRK1A levels or activity in relevant human cells has not been established. We filled this gap by testing the effects of a new DYRK1A inhibitor on trisomy 21 induced pluripotent stem cell derived neural progenitor cells and neurons, where DYRK1A expression and activity are increased. Our results demonstrate that Leucettinib-21, a potent and selective low-molecular weight pharmacological inhibitor of DYRK1A, decreases DYRK1A activity in human trisomy 21 neural progenitor cells and cortical neurons. We show for the first time that Leucettinib-21 reduces DYRK1A activity in a relevant human disease model, supporting future human trials. Summary StatementWe show for the first time that Leucettinib-21, a pharmacological inhibitor of DYRK1A, decreases DYRK1A activity in a human iPSC-derived neural cell culture model of Down syndrome.

Progressive cardiomyopathy is the leading cause of death in Duchenne muscular dystrophy (DMD). Dysregulation of calcium handling has been implicated in cardiomyopathy progression in DMD. Here we describe a therapeutic approach to improve calcium homeostasis in a mouse model of DMD using the novel therapeutic NDC-1171, which is a positive allosteric modulator of the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) pump. We synthesized NDC-1171 and treated 4-week-old D2.mdx mice (n=9) via oral gavage. A group of D2.mdx mice (n=9) and a group of DBA/2J mice (n=9; background strain) received a vehicle on the same schedule. We used ultrasound to assess left ventricular function, followed by a treadmill exhaustion test and a 4-paw grip strength test to assess skeletal muscle function. NDC-1171 attenuated cardiac functional decline in D2.mdx mice. At 16 weeks of age, left ventricular ejection fraction (LVEF) was significantly preserved in mice treated with NDC-1171 (57.7{square}{+/-}{square}0.5%) compared to mice treated with a vehicle (50.7{square}{+/-}{square}0.9%, p{square}<{square}0.05), though remained lower than background strain controls (62.4{square}{+/-}{square}0.6%). In contrast, functional behavior testing revealed no significant improvement in skeletal muscle function with treatment. These data suggest that treatment with the SERCA pump modulator NDC-1171 helps preserve cardiac function in a murine model of DMD, even as skeletal muscle function was impaired. Future work will be needed to determine if the benefits of this novel SERCA activator translate to large animal and clinical studies, but these initial results are promising and could help guide development of future treatments for pediatric patients with muscular dystrophy.

Xylazine is a 2-adrenergic agonist typically used in as a sedative and analgesic in veterinary medicine. For some years, xylazine has been reported as an additive to fentanyl on the illicit drug market and has been associated with severe side-effects including severe ulcerations and potential amputations at the sites of injection along with an increased risk of respiratory depression and death. We recently reported that xylazine has modest {kappa} opioid agonist activity in vitro and in vivo and asked if other 2-adrenergic agonists had similar off-target activities. To test this hypothesis, we profiled US FDA-approved 2-adrenergic agonists at 320 G protein coupled receptors (GPCRs) to identify potentially deleterious and/or beneficial off-targets. Although all other tested 2-adrenergic agonists were devoid of {kappa} opioid agonist activity, each had a distinct pattern of activity at various GPCRs and differential patterns of signaling bias at 2-receptor subtypes. These findings suggest potential molecular targets for both side-effects and therapeutic activities among known 2-adrenergic agonists.

Opioid addiction and misuse are a serious national crisis that affects public health, as well as social and economic welfare. Mortality due to opioid misuse is further exasperated by the combination of opioids with non-opioid respiratory depressants such as xylazine that are resistant to mu opioid receptor antagonists such as naloxone. This study tested the hypothesis that oxytocin can mitigate the severe opioid induced respiratory depression (OIRD) and mortality induced by high doses of fentanyl or the combination of fentanyl with xylazine. Our results show OXT can improve survival and respiratory function in both male and female rats with opioid induced respiratory depression caused by fentanyl, as well as a combination of fentanyl and xylazine. The improvement in respiratory function by OXT post fentanyl-xylazine was significantly greater than the recovery using only naloxone. Chemogenetic activation of OXT receptor positive neurons in the ventral respiratory group (VRG) provided similar benefits to that of OXT administration in reversing OIRD. These results indicate OXT is a promising therapeutic target for reversing OIRD and the respiratory depression that occurs with the combination of opioids and xylazine, a situation where naloxone is only partially effective. Additional translational benefits of OXT include it can be repurposed as it is already a FDA approved drug for other uses, has a high safety profile, and is unlikely to induce the withdrawal or reversal of analgesia that occurs with naloxone. Key PointsO_LIOxytocin (OXT) improves survival and respiratory function in both male and female rats with opioid induced respiratory depression (OIRD) caused by fentanyl C_LIO_LIOXT also reverses OIRD induced by the combination of fentanyl and xylazine C_LIO_LIThe improvement in respiratory function by OXT post fentanyl-xylazine was significantly greater than the recovery using only naloxone C_LIO_LIChemogenetic activation of OXT receptor positive neurons in the ventral respiratory group (VRG) provided similar benefits to that of OXT administration in reversing OIRD C_LIO_LIThese results indicate OXT is a promising therapeutic target for reversing OIRD and the respiratory depression that occurs with the combination of opioids and xylazine C_LI

Aiming to develop a high-throughput fluorimetric assay for the activity CYP1A2, we introduced 6-Methoxy-2-naphthoic acid (MONA) as a new fluorogenic substrate for this important metabolizer of antidepressants and psychotropic drugs in human liver. We demonstrated that oxidative demethylation of MONA by liver microsomes results in a red shift and a substantial increase in fluorescence. This effect, which is exceptionally well pronounced at alkaline pH, allowed us to develop a sensitive and robust high-throughput assay of MONA metabolism. Probing the activity of 15 individual recombinant human P450 enzymes, we found that only two P450 species exhibited activity in MONA demethylation: CYP1A2 (kcat=11.9{+/-}2.2 min-1, KM=578{+/-}106 {micro}M) and CYP2A6 (kcat=0.48{+/-}0.07 min-1, KM=54{+/-}15 {micro}M). Since the KM values of the two enzymes are well resolved and the turnover rate observed with CYP2A6 is much lower than that of CYP1A2, this new fluorogenic substrate is useful as a specific probe for CYP1A2 activity in HLM. Importantly, MONA is not metabolized by CYP1A1 and CYP2C19, which distinguishes it from all known CYP1A2 fluorogenic substrates. We then used MONA to investigate the effects of chronic alcohol exposure on CYP1A2 activity using a series of 23 proteomically characterized individual HLM preparations from donors with various levels of alcohol consumption. The substrate saturation profiles (SSP) acquired with these preparations were subjected to global kinetic analysis by approximating them with combinations of two Michaelis-Menten equations with globally optimized KM values of 11 and 553 {micro}M. The amplitudes (Vmax values) of both components showed a pronounced increase with increasing alcohol exposure of the liver donors. The Vmax of the minor high-affinity component was best correlated with the abundance of alcohol-inducible CYP2E1 enzyme. The correlation was further improved by combining it with the abundances of CYP2A6 and CPR. This finding suggests that this minor component reflects the activity of CYP2A6 in the complex with alcohol-inducible CYP2E1 protein. In contrast, the Vmax of the predominant CYP1A2-catalyzed low-affinity component revealed a pronounced correlation with the abundances of CYP1A2 and NADPH cytochrome P450 reductase (CPR). These results suggest a considerable increase in the rate of metabolism of drug substrates of CYP1A2 by chronic alcohol exposure that takes place despite an alcohol-induced decrease in CYP1A2 expression.

Polypharmacy, the concurrent use of multiple medications, is increasingly prevalent in older people and is associated with adverse outcomes such as falls, frailty, functional and cognitive decline, and increased hospitalization and mortality. The liver, as the primary site of metabolism, is exposed to varying drug concentrations during first pass metabolism, hepatic clearance and perfusion, potentially causing alterations in liver sinusoidal endothelial cells (LSEC). LSEC are specialized endothelial cells responsible for maintaining fenestrations - dynamic, transcellular pores that facilitate the exchange of substances between the blood and liver parenchyma. Disruption of fenestrations can compromise liver function, contributing to a variety of hepatic disorders. This study investigated the effects of four commonly prescribed drugs -- metoprolol, citalopram, oxybutynin and oxycodone -- on LSEC function. We examined their impact on LSEC viability, endocytosis, and fenestration morphology at both systemic steady-state and first-pass concentrations, separately and in a polypharmacy cocktail to model clinical exposure. All treatments induced sublethal metabolic changes, but effects on LSEC functions were drug- and concentration-dependent. Citalopram and oxybutynin caused dose-dependent defenestration, whereas metoprolol and oxycodone produced mild, non-dose-dependent effects. Endocytic activity was increased with oxybutynin, metoprolol, oxycodone, and the polypharmacy cocktail, while citalopram had no effect. The polypharmacy cocktail triggered synergistic defenestration at first-pass concentrations, but not at steady-state levels. These results highlight the concentration-dependent and combinatorial effects of polypharmacy on LSECs, emphasizing the need to consider endothelial responses in drug safety and pharmacokinetic assessments, particularly in patients exposed to multiple medications.

BackgroundAnthracyclines such as doxorubicin are effective chemotherapeutics but are limited by cardiotoxicity driven in part by mitochondrial dysfunction. Dysregulated mitochondrial dynamics, particularly excessive dynamin-related protein-1 (Drp1)-mediated fission, contribute to doxorubicin-induced cardiac injury and support selective survival of cancer cells. ObjectivesTo determine whether DRP1i2, a novel small molecule Drp1 inhibitor targeting a conserved domain shared between human and mouse, can function as a cardio-oncology therapeutic by reducing doxorubicin-induced cardiotoxicity while maintaining or enhancing anti-cancer efficacy. MethodsCardioprotective effects of DRP1i2 were evaluated in a murine model of chronic doxorubicin cardiotoxicity and in human induced pluripotent stem cell-derived cardiac microtissues exposed to acute doxorubicin injury. Anticancer activity was assessed across multiple cancer cell lines using 2D monolayers and 3D microtissues. ResultsIn vivo, DRP1i2 preserved left ventricular ejection fraction, reduced interstitial fibrosis and cardiomyocyte atrophy, and attenuated doxorubicin-induced myocardial proteomic remodelling. In human cardiac microtissues, DRP1i2 improved viability and restored contractile function despite persistent mitochondrial oxidative stress. DRP1i2 showed modest anticancer activity in MG63 osteosarcoma cells in both 2D and 3D systems and did not diminish doxorubicin efficacy in other cancer models (MDA-MB-231 breast, OVCAR3 ovarian, and A549 lung adenocarcinoma). Combined treatment further enhanced cytotoxicity selectively in MG63 cells. ConclusionsDRP1i2 exerts complementary cardioprotective and anticancer actions through modulation of shared mitochondrial pathways, identifying Drp1 as a druggable target in cardio-oncology. These findings support DRP1i2 as a first-in-class Drp1 inhibitor and highlight mitochondrial dynamics as a promising therapeutic axis to preserve anthracycline efficacy while reducing cardiotoxicity. Clinical PerspectivesExcessive Drp1-mediated mitochondrial fission links anthracycline cardiotoxicity with cancer cell survival. Inhibition with DRP1i2 preserved cardiac structure and function in a chronic doxorubicin cardiotoxicity model without compromising anti-cancer activity, representing mechanism-based cardioprotection, where the heart is protected by directly targeting the molecular processes driving injury. Translation will require pharmacologic profiling and testing in tumour-bearing and comorbid models, followed by early-phase trials to confirm safety and efficacy.

Aminopyridines, including 4-aminopyridine (4AP), 3,4-diaminopyridine, and [18F]3-fluoro-4-aminopyridine, are voltage-gated potassium (KV) channel blockers used clinically to enhance conduction in neurological disorders and to image demyelination by PET. Developing new aminopyridines may yield improved therapeutics or imaging agents. Here, we characterized the physicochemical properties (pKa, log D), KV channel-blocking activity, toxicity (LD50), and pharmacokinetics of a novel compound, 4-methyl-3-aminopyridine (4Me3AP). 4Me3AP was less basic and more lipophilic than 4AP and showed greater blocking potency across multiple KV channels expressed in Xenopus oocytes. In mice, 4Me3AP exhibited lower acute toxicity (LD50= 29.3 mg/kg) than 4AP (LD50= 12.7 mg/kg) and a longer plasma half-life. These findings indicate that 4Me3AP is a potent KV channel blocker with favorable pharmacological properties, supporting its potential for symptomatic treatment of demyelinating diseases.

CD4+ T helper cells are required for CD8+ killer T cells to suppress tumor growth. An orally-available small molecule surrogate of alpha-1 antitrypsin, Alphataxin, was previously demonstrated to elevate the numbers of circulating and tumor-infiltrating CD4+ T cells and to suppress kidney tumor growth in mice. To determine whether Alphataxin might be effective in other T cell-responsive cancers, mice orthotopically implanted with colon tumors were treated using Alphataxin and anti-PD-1 as monotherapies or in combination. Combination therapy significantly suppressed tumor growth (ORR = 37.5%) and increased tumor-infiltrating CD4+ T cells, CD8+ T cells, NK cells, M2 macrophages, and DC2 dendritic cells. Release of IFN-{gamma} by helper T cells in the tumor microenvironment appeared to contribute to the effectiveness of killer T cells in suppressing tumor growth. Toxicology studies in rats revealed no untoward effects. Alphataxin, to our knowledge the first and only drug developed to rapidly and sustainably increase the number of circulating and tumor-infiltrating CD4+ helper T cells, is a powerful therapeutic that provides long-term remission in T cell-responsive cancers in combination with anti-PD-1.

Renal cell carcinoma (RCC) is characterized by dysregulation of the kynurenine pathway (KP), which converts tryptophan to NAD+ while generating immunomodulatory metabolites. Therapeutic efforts have focused on inhibiting IDO1 at the pathway entry point, but the functional consequences of targeting downstream KP enzymes remain poorly characterized. We used CRISPR/Cas9 to generate knockouts of three KP enzymes in the RENCA murine RCC model--kynurenine 3-monooxygenase (KMO), quinolinic acid phosphoribosyltransferase (QPRT), and 3-hydroxyanthranilic acid dioxygenase (HAAO)--and evaluated effects on cell migration, colony formation, tumor burden, metastasis, and survival. KMO and QPRT knockouts consistently reduced migratory capacity and colony size in vitro. However, in vivo effects were distinct: while QPRT knockout reduced tumor burden, KMO knockout did not. Notably, we did not detect metastasis in female mice receiving KMO knockout RENCA cells. HAAO knockout produced divergent effects, increasing migration and colony size in vitro, but reducing tumor burden and metastasis in vivo. Mice challenged orthotopically with all three knockout cell lines had significantly extended survival compared to mice receiving wild type cells. These results indicate that individual KP enzymes exert distinct, context-dependent effects on RCC progression. The enhanced in vitro aggressiveness coupled with reduced in vivo tumorigenicity observed in HAAO knockout RENCA cells illustrates that cell culture phenotypes do not reliably predict tumor behavior, particularly when perturbing metabolic pathways with pleiotropic effects. Our findings suggest that targeting specific KP enzymes warrants further investigation as a therapeutic strategy in RCC.

Targeting the kappa opioid receptor (KOR) system has emerged as a potential alternative to current analgesics, however, advancing the therapeutic development of KOR requires further elucidation of its intracellular signaling events and modulators. Among these intracellular modulators, Regulators of G protein signaling (RGS) proteins act as key modulators of GPCR signaling to shape nociceptive circuits and influence pain processing. Despite this, the molecular diversity of RGS proteins that shape KOR signaling and its behavioral consequences remains largely unexplored. Here we report that RGS6, a member of the R7 RGS family, is highly expressed in nociceptive areas and modulates multiple modalities of KOR-dependent anti-nociception and nocifensive behaviors. Using global single and double knockout mouse models we show that this anti-nociceptive phenotype was highly specific to RGS6 within the R7 RGS family. Further we demonstrate that the R7 RGS family displays a lack of functional redundancy in regulation of KOR signaling and behaviors. Using peripherally restricted KOR agonists, we found that KOR-RGS6 anti-nociceptive signaling displays sex differences in a site-specific manner, as females but not males displayed enhanced anti-nociceptive and blunted nocifensive behaviors. Our findings suggest that RGS6 is a highly specific modulator of KOR-dependent anti-nociceptive signaling and plays an essential role in modulating nociceptive circuits, potentially aiding in the development of novel analgesic drugs and therapeutics.

BackgroundExercise-induced fatigue is a complex physiological phenomenon involving oxidative stress, inflammation, and metabolic disturbances. Ergothioneine (EGT), a naturally occurring amino acid with potent antioxidant properties, has garnered interest for its potential health benefits. This study aimed to evaluate the anti-fatigue effects of Gene III EGT in a mouse model of exhaustive exercise and to elucidate its underlying mechanisms. MethodsMale C57BL/6 mice were randomly divided into five groups: a control group (CTL), low-dose EGT (EGT-L, 10 mg/kg), medium-dose EGT (EGT-M, 30 mg/kg), high-dose EGT (EGT-H, 50 mg/kg), and a positive control group (Coenzyme Q10, 50 mg/kg). Mice were subjected to a 4-week treadmill training protocol, followed by an exhaustive running test. We measured exercise performance and collected blood and skeletal muscle samples at multiple time points to assess biochemical markers, inflammatory cytokines, antioxidant status, and key signaling proteins. ResultsGene III EGT supplementation, particularly at medium and high doses, significantly extended the time to exhaustion and running distance. Compared to the control group, EGT treatment significantly reduced post-exercise levels of lactic acid (LA), lactate dehydrogenase (LDH), and blood urea nitrogen (BUN). Furthermore, Gene III EGT suppressed the exercise-induced increase in pro-inflammatory cytokines, including IL-1{beta}, IL-6, and TNF-. The anti-fatigue effect of EGT was also associated with a reduction in malondialdehyde (MDA) and an increase in the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Mechanistically, EGT promoted the phosphorylation of AMP-activated protein kinase (AMPK) and the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1) in skeletal muscle, while also increasing the Bcl-2/Bax ratio, suggesting enhanced mitochondrial biogenesis and reduced apoptosis. ConclusionsOur findings demonstrate that Gene III EGT effectively enhances exercise performance and alleviates fatigue. The underlying mechanisms involve the mitigation of oxidative stress and inflammation, as well as the activation of the AMPK/PGC-1 signaling pathway to promote mitochondrial function and cellular protection. These results highlight the potential of Gene III EGT as a nutritional supplement for combating exercise-induced fatigue.

BackgroundHepatocellular carcinoma (HCC) remains a leading cause of cancer-related mortality worldwide, highlighting the urgent need for effective therapies. Niclosamide, an FDA-approved anthelmintic, reverses HCC gene expression profile to that of normal hepatocytes, and exhibits promising anti-tumor activity in HCC in vitro; however, its clinical translation is limited by poor aqueous solubility, low bioavailability, and short systemic exposure, resulting in lack of in vivo activity. We previously used an established phosphate prodrug approach to provide proof-of-concept that increasing oral bioavailability was essential for niclosamide to achieve in vivo anti-tumor activity. MethodsWe designed a panel of novel niclosamide prodrugs and screened eight candidates for water solubility, chemical stability, and in vitro anti-proliferative activity in HCC cell lines. The lead compound, SSL-0024, was further evaluated for its pharmacokinetics and anti-tumor efficacy in immunodeficient mice bearing orthotopic HCC patient-derived xenografts (PDX). Mechanisms underlying its observed activity were assessed through protein-level analysis of AKT-mTOR-STAT3, RAF, Wnt/{beta}-catenin signaling pathways, vasorin-associated pathways, and PD-L1. ResultsSSL-0024 demonstrated markedly improved aqueous solubility and stability in gastric and plasma conditions, supporting oral administration. Pharmacokinetic analyses revealed a plasma half-life of [~]24 hours, dramatically extended relative to native niclosamide. Once daily oral administration of SSL-0024 (100 mg/kg) in orthotopic HCC PDX mice achieved [~]60% tumor growth inhibition at only [~]46.8% of the dose required for the positive control (niclosamide ethanolamine), with minimal systemic toxicity. Mechanistically, SSL-0024 concurrently suppressed AKT-mTOR-STAT3 signaling, RAF kinases, Wnt, and VASN-associated pathways, with additional downregulation of PD-L1, resulting in reduced proliferation, survival, and immune-evasion signaling. ConclusionThrough rational design and systematic screening, we have identified a lead niclosamide prodrug candidate, SSL-0024, which exhibited improved water solubility and stability, extended plasma half-life, enhanced oral bioavailability, and preservation of biological activity in vitro and in vivo. Future studies will include combination therapy with standard-of-care treatments, as well as safety and formulation studies to enable its clinical translation for the treatment of HCC and other solid tumors impacted by the multiple oncogenic pathways modulated by niclosamide.

BackgroundPostoperative delirium (POD) is a frequent and severe neurocognitive complication following cardiac surgery, associated with poor long-term outcomes. The underlying mechanisms are unclear, and objective biomarkers are urgently needed. MethodsWe used pre- and post-operative plasma samples from 59 patients undergoing cardiac surgery in three separate studies with rigorous delirium assessment using the Confusion Assessment Method in a case-control design. Small extracellular vesicles (sEVs) were isolated from plasma, and their miRNA cargo was profiled using RNA sequencing. Target miRNAs were validated by qRT-PCR, and digital PCR (dPCR). The functional impact of the lead candidate miRNA was investigated in vitro by assessing tau phosphorylation and cell viability in HT22 neuronal cell line. ResultsThere were no differences in sEV morphology or numbers between patients with and without POD. While three candidate miRNAs were initially validated by qRT-PCR, subsequent dPCR analysis confirmed that only the perioperative change in plasma sEV-cargo miR-330-3p expression was significantly greater in patients who developed POD (n = 20) compared with those who did not (n = 20) (5.22 copies/L plasma; 95% Confidence Interval (CI), 1.187 to 9.256; p = 0.0139). Receiver operating characteristic curve analysis for this change yielded an area under the curve of 0.745 (95% CI, 0.589 to 0.901). In vitro overexpression of miR-330-3p in a neuronal cell line significantly increased the phosphorylation of tau at Ser199 (p < 0.0001) and Ser396 (p < 0.001) and reduced cell viability (p < 0.001). ConclusionsOur findings suggest that sEV-bound miR-330-3p increases in patients with POD after cardiac surgery. In vitro results suggest a potential pathogenic role for miR-330-3p, linking a systemic signal to tau-related neuronal injury. Clinical PerspectiveO_ST_ABSWhat Is New?C_ST_ABSO_LIThis study identifies a specific perioperative increase in small extracellular vesicle (sEV)-cargo miR-330-3p in patients with postoperative delirium (POD) following cardiac surgery. C_LIO_LIWe provide the first evidence that miR-330-3p directly induces tau hyperphosphorylation and reduces neuronal viability in vitro, establishing a potential mechanistic link between systemic sEV signaling and neurodegeneration. C_LI What Are the Clinical Implications?O_LIThe measurement of perioperative change in miR-330-3p could serve as an objective biological marker to assist in the early identification and risk stratification of patients at high risk for POD. C_LIO_LIThe identified miR-330-3p/tau pathway represents a potential new therapeutic target; future interventions aimed at inhibiting this specific miRNA might help prevent or mitigate POD-related neuronal injury. C_LIO_LIThese findings emphasize the importance of monitoring dynamic sEV-cargo changes to better understand and manage perioperative neurocognitive disorders. C_LI

BackgroundAlcoholic fatty liver disease (AFLD) is a progressive hepatic pathology triggered by chronic ethanol consumption, serving as the initial stage of severe liver injury. Currently, there are no FDA-approved pharmacological interventions that specifically target alcohol-induced hepatic steatosis or prevent disease progression, highlighting an urgent need for effective preventive strategies. This study evaluated the preventive efficacy and underlying mechanisms of Gene III Ergothioneine (EGT) in a clinically relevant preclinical model. MethodsC57BL/6 mice were randomized into five groups: a Control group, an alcoholic fatty liver Model group, a Positive control group treated with Silybin (100 mg/kg), and three EGT treatment groups (10, 30, and 50 mg/kg). The NIAAA mouse model was utilized to induce alcoholic fatty liver. Various biochemical, histological, and molecular markers were assessed to evaluate liver damage, alcohol metabolism, lipid profiles, oxidative stress, and inflammation. ResultsGene III EGT treatment significantly ameliorated hepatic steatosis and necrosis, as confirmed by H&E and Oil Red O staining. Notably, EGT accelerated alcohol clearance, reducing serum ethanol levels by up to 54.4% in a dose-dependent manner. Furthermore, EGT restored liver function markers (ALT, AST, GGT) and corrected dyslipidemia by lowering TG, TC, and LDL-C while elevating HDL-C. Mechanistically, EGT suppressed pro-inflammatory cytokines (IL-6, IL-1 {beta}) and mitigated oxidative stress by reducing malondialdehyde (MDA) accumulation and restoring superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. ConclusionGene III Ergothioneine prevents alcoholic liver injury through a dual mechanism: accelerating ethanol metabolism and enhancing hepatocyte antioxidative and anti-inflammatory defenses. These findings position EGT as a promising therapeutic candidate for AFLD management.

BackgroundCardiac hypertrophy is a key pathological process in hypertensive heart failure, yet current antihypertensive therapies do not directly target it. Red yeast rice (RYR), rich in monacolin K {beta}-hydroxy acid (MKA), is known for lipid-lowering effects, but its potential to ameliorate cardiac hypertrophy is unreported. PurposeTo investigate the effects of RYR-derived MKA on cardiac hypertrophy in spontaneously hypertensive rats (SHR) and elucidate its molecular mechanisms. MethodsSpontaneously hypertensive rats (SHR) were treated with 0.6% red yeast rice for 8 weeks to assess its effects on blood pressure, cardiac function (echocardiography), cardiac hypertrophy and fibrosis (histopathology), and multi-organ toxicity (histopathology). A multigenerational study was conducted to evaluate protective effects in offspring. Network pharmacology and transcriptomic analysis were integrated to predict molecular targets, which were subsequently validated by molecular docking and experiments. ResultsEight-week RYR treatment significantly reduced blood pressure, inhibited cardiac hypertrophy and fibrosis, and improved cardiac function without gender differences. No pulmonary, hepatic, or renal toxicity was observed. Offspring from treated parents exhibited further reduced hypertrophy upon continued treatment. Mechanistically, MKA bound ERK1/2 with high affinity, inhibiting its phosphorylation and downstream c-Fos expression, thereby downregulating hypertrophy markers. ConclusionRed yeast rice improves hypertensive cardiac hypertrophy via MKA-mediated inhibition of the ERK1/2/c-Fos pathway. Its multi-organ safety and transgenerational effects offer a novel dual-therapy strategy for hypertension and cardiac hypertrophy. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=139 HEIGHT=200 SRC="FIGDIR/small/710945v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@cbb85org.highwire.dtl.DTLVardef@1eb399dorg.highwire.dtl.DTLVardef@13746dorg.highwire.dtl.DTLVardef@140c512_HPS_FORMAT_FIGEXP M_FIG C_FIG

Although cholesterol (Chol) is widely recognized as a risk factor for cardiovascular disease, dietary Chol intake has been reported to extend the lifespan of stroke-prone spontaneously hypertensive rats (SHRSP). The mechanisms responsible for this paradoxical effect remain unclear. The present study examined changes in organ lipid profiles and associated molecular factors in SHRSP rats fed a Chol-enriched diet. Four-week-old male SHRSP/Izm rats were assigned to three groups and fed ad libitum for 12 weeks with either a control diet (Ctr), a diet supplemented with 1% w/w Chol (Chol), or a diet containing 1% w/w Chol plus 0.025% w/w lovastatin (Stt) to suppress endogenous Chol synthesis. Systolic blood pressure was measured before and after the feeding period, and tissues were collected for analyses of sterol content, fatty acid composition, prostaglandin E2 (PGE2) levels, and renal histopathology. Relative to the Ctr group, the Chol group exhibited a significant 9-10% reduction in systolic blood pressure. This reduction was accompanied by pronounced alterations in lipid profiles, including changes in phytosterol content and decreased arachidonic acid ratios in serum and kidney. There was a downward trend in hepatic PGE2 levels, and a similar tendency was observed in the kidney. Comparable changes in lipid profiles were observed in the Stt group. Histological analysis revealed modest attenuation of renal pathological features in Chol-fed rats. This study demonstrates for the first time that dietary Chol reduces renal phytosterol accumulation and suppresses the AA-PGE2 axis, changes that coincide with a 9-10% reduction in systolic blood pressure and attenuated glomerular inflammation. These integrated findings provide a mechanistic framework linking dietary Chol to the previously reported lifespan extension in this stroke-prone model. Although these changes may contribute to improved renal pathology, further studies are required to clarify causal relationships.

Acute kidney injury (AKI) is a serious and common clinical syndrome that currently has no effective treatment. Emerging evidence links coagulation pathways to kidney injury, particularly through coagulation proteases. Protease-activated receptors (PARs) are a family of G-protein coupled receptors (GPCRs) that are activated by proteolytic cleavage of their N termini, exposing a tethered ligand that initiates receptor signaling. PARs have been shown to play a major role in inflammation, vascular regulation, and tissue injury. PARs play key roles in inflammation, vascular regulation, and tissue injury. Previous work from the Hamm laboratory demonstrated that PAR4 contributes to AKI progression, as PAR4 knockout mice were protected in both unilateral ureteral obstruction and ischemia-reperfusion-based models of kidney disease. In this study, we investigated the potential of a PAR4 antagonist, VU6073819, at mitigating AKI progression in an ischemia-reperfusion injury (IRI) mouse model. PAR4 antagonism not only alleviated kidney injury and inflammatory response, but it significantly improved the survival. These findings identify PAR4 as a promising therapeutic target for AKI.

Opioid use disorder (OUD) is a chronic, relapsing disease driven by the reinforcing properties of opioids and perpetuated by avoidance of the negative affective states associated with the absence of the drug. Most available OUD treatments directly engage the {micro}-opioid receptor and may induce side effects that can compromise their therapeutic efficacy, thus underscoring the need for novel therapeutic alternatives. Calcitonin gene-related peptide (CGRP) is produced by a small population of neurons in the parabrachial nucleus (PBN) that has been shown to modulate itch, pain, as well as appetitive behaviors. Using a cell-specific nuclear labeling approach coupled with RNA-sequencing, we generated a baseline transcriptome of CGRPPBN neurons and confirmed expression of multiple genes associated with behavioral responses to appetitive stimuli, as well as enrichment of the {micro}-opioid receptor, suggesting that CGRPPBN neuron function may be sensitive to the presence of opioids. Indeed, cFos immunostaining showed that CGRPPBN neuron activity increases during early morphine abstinence and reduces gradually over 48 hours. Given the inhibitory effects of opioids on CGRPPBN neuron activity, we next tested whether these neurons could regulate opioid reinforcement. Using a mouse model of morphine intravenous self-administration, we found that chemogenetic inhibition of CGRPPBN neurons significantly reduced the number of morphine rewards earned in both single-dose and dose-response tests but did not affect context-induced morphine seeking after 21 days of abstinence. These results suggest that CGRPPBN neurons are sensitive to opioid administration and can regulate appetitive behaviors such as morphine-taking. Considering that CGRP signaling is regulated by opioid administration, molecular targets that regulate CGRP neurotransmission without direct -opioid receptor engagement may therefore serve as novel therapeutic avenues for the treatment of OUD. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=195 SRC="FIGDIR/small/712659v1_ufig1.gif" ALT="Figure 1"> View larger version (56K): org.highwire.dtl.DTLVardef@1fb9c9borg.highwire.dtl.DTLVardef@1e6ba79org.highwire.dtl.DTLVardef@dc60f5org.highwire.dtl.DTLVardef@61adaf_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundCardiac myosin inhibitors (CMIs) demonstrate advantages over other guideline-directed therapy for patients with obstructive hypertrophic cardiomyopathy (oHCM). By reducing hypercontractility, CMIs abrogate excessive systolic function and improve diastolic function; diminish hypertrophy of the left ventricle (LV); and improve exercise capacity, functional class, and symptoms. Whether CMIs are therapeutic in heart failure with preserved ejection fraction (HFpEF) is of interest because a significant subset of these patients demonstrate supranormal ejection fractions and abnormal LV structure, characteristics in common with HCM, where CMIs have proved effective. ObjectivesOur goal was to characterize the mechanism of myosin inhibition for ulacamten and determine its efficacy in a rodent model of HFpEF. MethodsUlacamten was characterized using biophysical and biochemical approaches, cardiomyocytes from humans and the ZSF1 obese rat model of HFpEF, hypercontractile human-engineered heart tissues, and echocardiography in the ZSF1 rat model. ResultsUnlike the other CMIs, aficamten and mavacamten, ulacamten binds outside the S1 domain of myosin and requires the regulatory light chain domain to bind and inhibit the activity of 2-headed myosin. Ulacamten only partially inhibits the myosin ATPase activity in both myofibrillar and protein systems, but inhibition of contractility was nearly complete in cardiomyocytes. Improvement in relaxation was demonstrated in hypercontractile-engineered heart tissues, and chronic treatment of ZSF1 obese rats showed benefits in both cardiac structure and function. ConclusionsUlacamten inhibits myosin in a manner distinct from aficamten and mavacamten, potentially broadening the mechanistic properties of CMIs available for treatment of hypercontractile cardiac dysfunction. CONDENSED ABSTRACTCardiac myosin inhibitors (CMIs) abrogate excessive systolic function and improve diastolic function, diminish cardiac hypertrophy, and improve exercise capacity in humans with obstructive hypertrophic cardiomyopathy (oHCM). Supranormal ejection fraction underlies heart failure with preserved ejection fraction (HFpEF) in some patients. We describe a new CMI, ulacamten, with binding and inhibitory properties distinct from two other FDA-approved CMIs, aficamten and mavacamten. Specifically, ulacamten requires 2-headed myosin to inhibit activity, whereas aficamten and mavacamten inhibit single-headed myosin. Ulacamten inhibits contractility in primary myocytes isolated from control human and hypercontractile ZSF1 obese rat hearts, as well as engineered heart tissues created with induced pluripotent stem cell cardiomyocytes bearing an HCM mutation. Chronic treatment of ZSF1 obese rats as a preclinical model of HFpEF improves diastolic function and reduces hypertrophy and fibrosis, broadening the potential mechanistic landscape of CMIs. Visual abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=96 SRC="FIGDIR/small/701387v2_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@11f9cecorg.highwire.dtl.DTLVardef@776847org.highwire.dtl.DTLVardef@15f19ddorg.highwire.dtl.DTLVardef@9b20c6_HPS_FORMAT_FIGEXP M_FIG C_FIG