Journal of Pharmacology and Experimental Therapeutics最新文献

Cellular senescence, a persistent state of cell cycle arrest, accumulates in aged organisms, contributes to tissue dysfunction, and drives aging-related phenotypes. Clearance of senescent cells decreases chronic, low-grade inflammation and restores tissue repair capacity, thus improving human health and lifespan. Senolytics that selectively eliminate senescent cells have become a promising antiaging strategy. To date, current senolytics are largely developed by repurposing anticancer agents. Therefore, senolytics usually possess various on- and off-target toxicities. These toxicities could preclude their clinical use as antiaging agents, as elderly people are more susceptible to adverse drug effects than young individuals. Proteolysis targeting chimeras as senolytics, termed "SenoTACs," are attractive for more effective treatment of aging-related diseases. In comparison to small molecule inhibitors, SenoTACs can eliminate senescent cells by degrading targeted proteins in a substoichiometric manner, providing better target ability, longer-lasting therapeutic effect, broadened target capability, and decreased drug resistance. Recent efforts have led to the development of several senescence-targeting proteolysis targeting chimeras, including ARV825, PZ15227, 753B, Gal-ARV-771, and Gal-MS99, which exhibit selective senolytic activity and improved safety and efficacy profiles when compared with small molecule inhibitors. In this minireview, we summarize the development of the emerging field. SIGNIFICANCE STATEMENT: The severe toxicities associated with current senolytics may limit their clinical utility as antiaging agents, as older populations are more susceptible to adverse drug effects. PROteolysis TArgeting Chimeras (PROTACs) that induce selective degradation of target proteins, are emerging as a promising therapeutic strategy to address this unmet medical need. Recently, PROTACs have been explored as novel senolytics-termed "SenoTACs," which display improved safety and efficacy in targeting senescent cells for fighting aging-related diseases.

Age-related dysfunction of the central nervous system, including cognitive impairment and visual disorders, is a major concern for the aging population, affecting health span and quality of life. Age-related vascular dysfunction in the central nervous system includes an increase in blood-brain or blood-retina barrier permeability, an increase in vascular fragility, and impaired neurovascular coupling, contributing to cognitive impairment and vision loss. While these pathologies occur in the brain and eye with age, gaps remain in our understanding of the underlying cellular mechanisms. During the process of endothelial-to-mesenchymal transition (EndMT), endothelial cells lose their characteristic endothelial phenotypes, which are critical for vascular function, such as barrier integrity, and transition to a mesenchymal-like phenotype. EndMT is triggered by many age-related stimuli and is involved in the progression of many age-related diseases (eg, atherosclerosis, cardiovascular disease, etc). Here, we review what is known about the role of EndMT in vascular fragility in the aging brain and eye, explore the mechanistic links between endothelial cell transdifferentiation and age-associated vascular pathologies of the central nervous system, and identify potential therapeutic targets ripe for future exploration with the goal of preserving vascular function with aging by regulating EndMT. SIGNIFICANCE STATEMENT: Endothelial-to-mesenchymal transition is a key form of cellular plasticity that leads to disrupted barrier function and vascular disorders. Here, we evaluate what is known about this process in the brain, highlight potential targetable mechanisms to block it, and identify areas where further research is needed.

Enteroendocrine cells (EECs) in the gastrointestinal tract play a critical role in sensing dietary fat and regulating the secretion of gut hormone. However, chronic high-fat diet (HFD) intake can lead to maladaptive changes in these cells, impairing hormone regulation. Transient receptor potential ankyrin 1 (TRPA1), an ion channel endogenously expressed in EECs, is known to promote gut hormone secretion when activated. Previous studies have shown that gut TRPA1 expression is reduced in HFD-fed mice, but the underlying molecular mechanisms remained unclear. In this study, we used the secretin tumor cell-1 (STC-1) enteroendocrine cell line treated with a fatty acid (FA) mixture (oleic acid: stearic acid in a 2:3 ratio) to mimic chronic HFD exposure in vitro. Our data from label-free proteomics, flow cytometry, and western blotting revealed that FA treatment causes TRPA1 downregulation through AMP-activated protein kinase and Ca²⁺ signaling pathways. This downregulation was accompanied by altered expression of genes and proteins involved in gut hormone synthesis and secretion. We further investigated the protective effect of allicin, a natural TRPA1 agonist found in garlic. Allicin treatment prevented TRPA1 downregulation both in FA-treated STC-1 cells and in HFD-fed C57BL/6J mice. In conclusion, this study elucidates the AMP-activated protein kinase-dependent mechanisms behind FA-induced TRPA1 downregulation in EECs and highlights how this contributes to gut hormone dysregulation. Importantly, dietary TRPA1 agonists such as allicin can counteract these effects, suggesting potential for development of functional foods (eg, allicin, thiocyanates, cuminaldehyde, cinnamaldehyde) to mitigate HFD-related gut hormone disturbances. SIGNIFICANCE STATEMENT: The results of this study showed that fatty acids downregulate transient receptor potential ankyrin 1, a key ion channel involved in regulating the secretion of gut hormones. Furthermore, this study investigated the potential protective effects of allicin, a dietary transient receptor potential ankyrin 1 agonist, using both an in vitro secretin tumor cell-1 model and an in vivo high-fat diet-fed C57Bl/6 mouse model.

Pancreatic ductal adenocarcinoma (PDA) is an almost universally fatal disease. Recent advances in the understanding of PDA bioenergetic dynamic equilibrium have illuminated a potential therapeutic target in bromodomain-related protein 4 (BRD4), the most active member of the bromo- and extraterminal domain (BET) protein family of transcription factors. We previously demonstrated that BET inhibitors (BETi) decrease PDA cell proliferation and enhance chemosensitivity. We hypothesized that BETi activates mitophagy and ferroptosis in PDA. Using pharmacological and genetic BRD4 inhibition in PDA patient-derived models, we investigated the effects of BETi on mitochondrial function, mitochondrial protein complex production, ATP production, cellular respiration, autophagy/mitophagy, and murine tumor growth with BMS-986158, a BETi. We determined the role of BRD4 in PDA by evaluating mitophagy and autophagy. In PDA models, we found that BETi decreased cellular respiration (P < .01), decreased ATP production (P < .001), and increased intracellular iron uptake (P < .01) while inducing mitophagy through dysregulated mitochondria complex protein levels. Murine PDA tumors grew slower and were smaller when treated with BETi compared with the control treatment. PDA tumors from experimentally treated mice contained more lipid vacuoles than those from the vehicle control group (P < .01), consistent with ferroptosis. BETi therapy decreased isocitrate dehydrogenase-1 expression, indicating increased chemosensitivity. BETi dysregulate mitochondrial complexes inducing mitophagy. BETi is a promising therapeutic strategy for attacking oncogenic mitochondrial behavior in PDA. We demonstrated a series of mitochondrial-centered events in a temporal sequence leading to cell death. This treatment controls tumors and increases chemosensitivity, offering a novel therapeutic strategy. SIGNIFICANCE STATEMENT: Bromo- and extraterminal domain inhibition is a novel therapeutic strategy for attacking oncogenic mitochondrial behavior in pancreatic ductal adenocarcinoma. Using this strategy in patient-derived models, this study demonstrated a series of mitochondrial-centered events in a temporal sequence leading to cell death and tumor control.

Colorectal cancer remains a leading cause of cancer-related mortality, necessitating the development of novel therapeutic strategies. In this study, we investigate the pharmacological and toxicological properties of JAMC-4/108, a traditional Mongolian herbal extract, in human colonic adenocarcinoma (HT-29) and normal colonic epithelial (CCD 841 CoTr) cells. Using high-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight-tandem mass spectrometry fingerprinting, we characterized its chemical composition, while a combination of cellular, biochemical and molecular assays provided mechanistic insights into its cytotoxic effects. The ethanol extract of JAMC-4/108 exhibited substantial selective cytotoxicity in HT-29 cells by inducing apoptosis and necrosis via caspase-3, cleaved caspase-7 and poly(ADP-ribose) polymerase activation, while the water extract primarily triggered caspase-9-mediated apoptosis. Both extracts modulated oxidative stress pathways, increasing Nrf2, Keap1 and LC3A/B levels, with the ethanol extract also upregulating NQO1, suggesting metabolic implications. In contrast, the ethanol extract had minimal apoptotic effects in normal colonic epithelial cells, whereas the water extract primarily influenced caspase-9 expression, indicating a distinct toxicity profile. Additionally, both extracts altered cell cycle progression-stimulated NOx release and modulated Fe³⁺ ion and DPPH radical pools in a concentration-dependent manner. Our findings highlight the selective anticancer potential of JAMC-4/108 and provide mechanistic insights into its pharmacological and toxicological effects, supporting its further evaluation for therapeutic development and safety assessment. SIGNIFICANCE STATEMENT: This study demonstrates the selective anticancer activity of JAMC-4/108, a Mongolian herbal extract, against colorectal cancer cells, with distinct apoptotic mechanisms and minimal toxicity to normal cells. These findings support the potential of JAMC-4/108 as a novel therapeutic candidate for colorectal cancer treatment, highlighting its pharmacological efficacy and safety profile for further development.

Metabolic dysfunction-associated steatohepatitis (MASH) poses a significant public health challenge, characterized by liver fat accumulation accompanied with inflammation and cell damage. Patients with MASH commonly exhibit hypercoagulability. Our previous work showed that direct oral anticoagulants exert anti-inflammatory effects in early stages of metabolic dysfunction. Mitigation of thromboinflammation ameliorated the manifestations of cardiometabolic complications. Here, we examine the protective effects of rivaroxaban in a rat model of MASH and compare it to representatives of 2 other antithrombotic drug classes, enoxaparin and clopidogrel, as well as silymarin, a bona fide hepatoprotective agent. Rats were divided into 6 groups: control, MASH (induced by an atherogenic diet), and treatment groups receiving either silymarin (50 mg/kg by mouth), rivaroxaban (20 mg/kg by mouth), enoxaparin (2 mg/kg subcutaneously), or clopidogrel (6.75 mg/kg by mouth) for 8 weeks, starting in the third week of induction. MASH rats showed elevated markers of visceral adipose thromboinflammation, along with liver injury markers (aspartate aminotransferase, alanine aminotransferase, and serum albumin), heightened hepatic levels of inflammatory cytokines (interleukin [IL]-1β and IL-6), reduced antioxidant capacity, and an imbalance in coagulation factors (elevated activated coagulation Factor X and Factor VIII/Protein C) compared with the control group. Anticoagulants and silymarin treatment led to varying degrees of amelioration of these MASH-associated abnormalities. Rivaroxaban demonstrated the most substantial improvement in thromboinflammatory markers, reaching levels comparable to the control group, with percentage improvements of approximately 52%, 49%, and 42% in activated coagulation Factor X, IL-1β, and IL-6, respectively. These findings suggest that direct oral anticoagulants hold promise as therapeutic agents for MASH by targeting the underlying thromboinflammatory state. SIGNIFICANCE STATEMENT: Metabolic dysfunction-associated steatohepatitis is a global health issue. In a rat model of the disease, rivaroxaban improves liver injury markers, outperforming bona fide hepatoprotective substances. This study emphasizes the role of thromboinflammation in metabolic dysfunction-associated steatohepatitis and highlights direct anticoagulants as a potential novel treatment approach.

The incidence of fatal drug overdoses has increased dramatically over the past decade due to the widespread availability of fentanyl and its analogs. As a complementary strategy to current overdose reversal agents, monoclonal antibodies (mAbs) are in development as therapeutics for prevention and reversal of fentanyl overdose. In the present study, the anti-fentanyl mAb HY6-F9 was tested for reversal of fentanyl-induced respiratory arrest (apnea) in a porcine model. In a first study, following fentanyl-induced apnea, chimeric HY6-F9 and naloxone control were administered as an intravenous bolus. Both chimeric HY6-F9 and naloxone restored spontaneous breathing within 90 seconds. Treatment with mAb increased the concentration of fentanyl in serum by 10-fold within the first minute after mAb bolus administration. In a second study, after induction of apnea, humanized HY6-F9 and naloxone control were administered as a slow intravenous infusion over 10 minutes to determine the ED₅₀ to restore baseline breathing. In this study, the mean ± SEM ED₅₀ of humanized HY6-F9 and naloxone to restore baseline respiratory rate were 16.0 ± 1.3 mg/kg and 6.9 ± 1.8 μg/kg, respectively. During mAb infusion, the concentration of fentanyl in serum increased proportionally to the concentration of infused mAb. The anti-fentanyl mAb ablated fentanyl-dependent opioid receptor activation in an in vitro system with concentrations of fentanyl similar to those observed in pigs after mAb treatment. These results demonstrate the efficacy of an anti-fentanyl mAb as a treatment to reverse fentanyl overdose. SIGNIFICANCE STATEMENT: Treatments for opioid use disorder and overdose are urgently needed. Here, we show that an anti-fentanyl monoclonal antibody reversed fentanyl-induced apnea in pigs, and caused rapid (<1 minute) redistribution of fentanyl into serum. Fentanyl was 99% bound by monoclonal antibodies and showed no activity at the opioid receptor.