Journal of Pharmacology and Experimental Therapeutics最新文献

Tyrosine kinase inhibitors (TKIs) targeting the BCR-ABL fusion protein, such as imatinib (Gleevec), have revolutionized targeted cancer therapies. However, drug resistance and side effects, particularly those affecting hemostasis, continue to pose significant challenges for TKI therapies. As tyrosine kinases serve pivotal roles in platelet hemostatic function, we investigated the potential impact of both established and emerging ABL TKIs on human platelet activities ex vivo Our study included standard-of-care agents (e.g., imatinib and nilotinib), and second-generation ABL inhibitors including ponatinib and bosutinib designed to mitigate drug resistance. Additionally, we explored the effects of allosteric inhibitors targeting the myristoyl pocket of ABL (e.g., asciminib and GNF-2), and novel agents in preclinical development, including ELVN-919, which uniquely exhibits high specificity for the ABL kinase active site. Our findings reveal that while ABL inhibitors such as ponatinib and bosutinib impede platelet activity, highly specific new-generation ABL inhibitors, including first-in-class therapeutics, do not impact platelet function ex vivo Overall, these new insights around the effects of ABL TKIs on platelet function could inform the development of targeted therapies with reduced hematologic toxicities. Significance Statement This study examines the effects of clinically relevant small molecule BCR-ABL tyrosine kinase inhibitors (TKIs) on platelet activity. This analysis includes first-time assessments of agents such as asciminib and ELVN-919 on human platelet function ex vivo, alongside established therapies (e.g., imatinib, ponatinib) with well-characterized effects on platelet function, to discern potential anti-platelet and other effects of BCR-ABL TKIs and inform clinical safety.

Androgen deprivation is the standard treatment for prostate cancer (PCa) patients. However, the disease eventually progresses as castration-resistant PCa (CRPC). Enzalutamide, an AR inhibitor, is a typical drug to treating CRPC and due to continuous reliance on the drug, can lead to Enzalutamide-resistance (ENZ-r). This highlights the necessity for developing novel therapeutic targets to combat the gain of resistance. Metformin has been recently investigated for its potential anti-tumorigenic effects in many cancer types. In this study, we used enzalutamide and metformin in combination to explore the possible rescued efficacy of enzalutamide in the treatment of ENZ-r CRPC. We first tested the effects of this combination treatment on cell viability, drug synergy, and cell proliferation in ENZ-r CRPC cell lines. After combination treatment, we observed a decrease in cell proliferation and viability as well as a synergistic effect of both enzalutamide and metformin in vitro Following these results, we sought to explore how combination treatment effected mitochondrial fitness utilizing mitochondrial stress test analysis and mitochondrial membrane potential (MMP) shifts due to metformin's action in inhibiting Complex I of oxidative phosphorylation. We employed 2 different strategies of in vivo testing using 22Rv1 and LuCaP35CR xenograft models. Finally, RNA sequencing revealed a potential link in the downregulation of Ras/MAPK signaling following combination treatment. Significance Statement Increasing evidence suggests that oxidative phosphorylation might play a critical role in the development of resistance to cancer therapy. We showed that targeting oxidative phosphorylation with metformin can enhance the efficacy of enzalutamide in castration-resistant prostate cancer in vitro.

Amitriptyline, a pleiotropic tricyclic antidepressant, possesses anti-oxidant and anti-inflammatory properties. Despite its diverse benefits, the specific effects of amitriptyline on IBD are not yet well defined. To explore this, we utilized a DSS-induced colitis model to examine the anti-inflammatory effects of amitriptyline and the underlying mechanisms by which it operates. Our research revealed that amitriptyline is effective in alleviating several pathological manifestations associated with colitis. This includes improvements in body weight retention, reductions in DAI, lessening of colon length shortening, and repair of colonic mucosal damage. Treatment with amitriptyline significantly protected mucosal injury by preserving the population of goblet cells and increasing the expression of tight junction proteins. Furthermore, we observed that amitriptyline effectively countered immune cell infiltration, specifically neutrophils and macrophages, while simultaneously lowering the levels of inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Additionally, RNA sequencing analysis pointed to the potential involvement of the TLR pathway in the anti-colitic effects induced by amitriptyline. Subsequent Western blot analysis indicated that amitriptyline significantly inhibited the TLR4-mediated NF-κB signaling pathway. To bolster our findings, in vitro studies demonstrated that amitriptyline down-regulated the TLR4/NF-κB/MAPK signaling cascades in mouse macrophages stimulated with LPS. Further molecular investigations revealed that amitriptyline was able to suppress the elevated expression of MD-2 that LPS stimulation typically induces. In summary, our findings suggest that amitriptyline effectively mitigates DSS-induced colitis in mice through the inhibition of TLR4/MD-2 pathway signaling, indicating its potential repurposing for IBD treatment. Significance Statement The potential of utilizing amitriptyline in treating IBD appears promising, leveraging its established safety and dosing profile as an antidepressant. Our observations show that amitriptyline can alleviate pathological symptoms, inflammation, and intestinal mucosal damage in mice with colitis induced by DSS. The protective effect observed appear to be linked to the inhibition of the TLR4/MD2 signaling pathway. By exploring novel applications for existing medications, we can optimize amitriptyline's efficacy and broaden its impact in both medical and commercial contexts.

The objective of this study is to investigate whether PI3kinase (PI3K) and p38 mitogen-activated kinase contributes to the protection of irisin during hemorrhage/resuscitation. Experimental groups were divided by receiving the different treatments during resuscitation: I) Hemorrhage: Adult male CD-1 mice were subjected to hemorrhage at a mean arterial blood pressure of 35~45 mmHg for 60 min followed by 120 min of resuscitation (n=13); II) Hemorrhage + Irisin: receiving irisin (5µg/kg) (n=13); III) Hemorrhage + Irisin + PI3K inhibitor: receiving both Ly294002 (1mg/kg, i.v.) and irisin (n=6); IV) Hemorrhage + Irisin + p38 inhibitor: receiving SB202190 (1mg/kg, i.v.) and irisin (n=6). As compared to hemorrhage/resuscitation control, irisin improved the cardiac function and recovery of hemodynamics in association with the decreased systemic IL-1, IL-6, and TNF-α, which was completely abrogated by PI3K or p38 inhibitions. Furthermore, inhibition of PI3K or p38 abolished irisin-induced reduction of the infiltration of inflammatory cells and TUNEL-positive apoptosis in the cardiac and skeletal muscles. Irisin reduced TNF-α and IL6 expression in cardiac and skeletal muscle, which was abrogated by inhibition of PI3K or p38. Irisin-treated hemorrhage increases the phosphorylation of PI3K and p38 in both cardiac and skeletal muscle, which was mitigated by inhibition of PI3K or p38. Conclusion: PI3K and p38 play a critical role in modulating the protective effect of irisin during the hemorrhage/resuscitation. Significance Statement 1). This study has identified a critical pathway in regulation of trauma/hemorrhage by using a preclinical and reproducible model, in which Irisin, as a hormone factor, stimulates PI3K and p38 pathways to induce the protection against traumatic conditions. 2). The study holds promise to develop a new therapeutic strategy to target irisin and its pathway related to PI3K and p38 to treat trauma and its comorbidities to reduce mortality for clinical implication.

Progressive multiple sclerosis (PMS) represents the worsening phase of the disease by accumulative neurodegeneration and disability, mainly refractory to current treatments. The therapeutic options remain challenging based partially on the lack of understanding of the pathogenic mechanisms but also because the early dogma was centered on neuroinflammation, overshadowing the critical role of the tissue repair process. The tissue repair target should necessarily start early in disease development and PMS should combine anti-inflammatory and neuroprotective therapeutic strategies. Increasing preclinical evidence, together with the new era of omics applied on frozen human brain tissue, shed light on some ligand receptors axis, such as GAS6/TYRO3 and PROS1/AXL required to dampen inflammation, promote tissue repair and engage remyelination, at the early stages of multiple sclerosis (MS) as a critical step in preventing or stopping neurodegeneration. Here, we will discuss those receptor/ligand pairs that could be targetable for therapeutic intervention in progressive MS disease. Significance Statement The aim for PMS should be to combine anti-inflammatory and neuroprotective therapeutic strategies based on early intervention. The TYRO3, AXL, and MERTK (TAM) signaling axis, particularly GAS6/TYRO3 and PROS1/AXL, which are involved in tempering inflammation, promoting tissue repair, and engaging remyelination, could significantly benefit patients at the early PMS.

Despite considerable efforts, there remains no FDA-approved medications for cocaine use disorder (CUD). One strategy to mitigate cocaine craving and relapse is to elevate dopamine (DA). The DA transport inhibitor and releaser d-amphetamine has been shown to decrease cocaine self-administration (SA), although it has abuse liability. Recently, several modafinil analogues reduced cocaine SA in rats and monkeys, including JJC8-088, characterized as "cocaine like" in rats, and JJC8-091, characterized as "atypical" and not SA by rats. The present studies evaluated the reinforcing effects of both compounds in monkeys under several conditions. For Experiment 1, four male cocaine-experienced rhesus monkeys self-administered cocaine (0.001-0.3 mg/kg/injection), JJC8-088 (0.001-0.3 mg/kg/injection), and JJC8-091 (0.1-3.0 mg/kg/injection) under a progressive-ratio (PR) schedule of reinforcement. Both JJC compounds functioned as reinforcers with equal reinforcing strength to cocaine. Although JJC8-091 was less potent than cocaine, JJC8-088 and cocaine had similar potencies. For Experiment 2, one male and two females drug-naïve cynomolgus monkeys responded on a fixed-ratio schedule of food reinforcement. JJC8-091 was self-administered at rates higher than saline in all three monkeys. In Experiment 3, monkeys from Experiment 2 responded under a concurrent drug vs. food choice paradigm and given access to cocaine or JJC8-091 under these conditions. At doses equal to or one-half log-units higher than doses used in Experiment 2, cocaine, but not JJC8-091, was chosen over food. Together, these results demonstrate that while JJC8-091 may be reinforcing under some conditions, its reinforcing strength, in the presence of an alternative reinforcer, is substantially less than cocaine. Significance Statement JJC8-088 and JJC8-091 have shown efficacy is reducing cocaine self-administration in rats and in nonhuman primates. This study found that both compounds maintained self-administration in monkeys responding under several conditions. However, when given access to an alternative reinforcer during the self-administration session, JJC8-091 was not reinforcing, suggesting that JJC8-091 may be a viable candidate for CUD since, in the human population, alternatives to drug use are often available.

Post-traumatic stress disorder (PTSD) is caused by exposure to a traumatic or stressful event. Symptoms related to this disorder include persistent re-experiencing of memories and fear generalization. Current pharmacological treatments for PTSD are insufficient, with fewer than 30% of patients reporting symptom remission. This study aims to determine the efficacy of acute (R,S) ketamine and chronic fluoxetine (FLX) in reducing fear memory and fear generalization. In rodents, fear conditioning (FC) is commonly used in the literature to induce behaviors related to symptoms of PTSD, and the open field test (OFT) can assess anxiety and fear generalization behaviors during the exploration of a novel environment. In this study, FC consisted of a white noise cue stimulus and four inescapable foot shocks. Treatments began 4 hours after FC. Fear and anxiety behaviors were recorded during re-exposure to the FC stimuli at 24 hours and 2 weeks. The OFT was conducted one day before the last FC re-exposure. Results support the combined use of acute ketamine and chronic FLX as a treatment for reducing behaviors indicative of fear memory during re-exposure at 2 weeks, but not behaviors indicative of anxiety and fear generalization in the OFT. FLX alone was most effective in reducing behaviors related to fear generalization. This study contributes to the existing literature on pharmacological treatment for fear and anxiety behaviors relating to fear memory and fear generalization. Continued research is necessary to replicate results, optimize treatment protocols, and investigate the molecular adaptations to trauma and treatment. Significance Statement Up to 6% of people in the United States will develop PTSD within their lifetime, and less than half of those individuals will find relief from their symptoms given the current therapeutic options. This study offers preliminary support for the efficacy of ketamine and FLX in reducing PTSD-like behaviors induced by fear-conditioning in mice. Compared to current standard treatments, results indicate the potential for a more effective therapeutic option for those with stress-related disorders, such as PTSD.

Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) affects nearly half of the 39 million people living with HIV. HAND symptoms range from subclinical cognitive impairment to dementia; the mechanisms that underlie HAND remain unclear and there is no treatment. The HIV protein transactivator of transcription (TAT) is thought to contribute to HAND because it persists in the central nervous system and elicits neurotoxicity in animal models. Network hyperexcitability is associated with accelerated cognitive decline in neurodegenerative disorders. Here we show that the antiepileptic drug levetiracetam (LEV) attenuated aberrant excitatory synaptic transmission, protected synaptic plasticity, reduced seizure susceptibility, and preserved cognition in inducible TAT (iTAT) transgenic male mice. iTAT mice had an increased frequency of spontaneous excitatory postsynaptic currents in hippocampal slice recordings and impaired long-term potentiation, a form of synaptic plasticity that underlies learning and memory. Two-week administration of LEV by osmotic minipump prevented both impairments. Kainic acid administered to iTAT mice induced a higher maximum behavioral seizure score, longer seizure duration, and shorter latency to first seizure, consistent with a lower seizure threshold. LEV treatment prevented these in vivo signs of hyperexcitability. Lastly, in the Barnes maze, iTAT mice required more time to reach the goal, committed more errors, and received lower cognitive scores relative to iTAT mice treated with LEV. Thus, TAT expression drives functional deficits, suggesting a causative role in HAND. As LEV not only prevented aberrant synaptic activity in iTAT mice but also prevented cognitive dysfunction, it may provide a promising pharmacological approach to the treatment of HAND. SIGNIFICANCE STATEMENT: Approximately half of people living with human immunodeficiency virus (HIV) also suffer from HIV-associated neurocognitive disorder (HAND), for which there is no treatment. The HIV protein transactivator of transcription (TAT) causes toxicity that is thought to contribute to HAND. Here, the antiepileptic drug levetiracetam (LEV) prevented synaptic and cognitive impairments in a TAT-expressing mouse. LEV is widely used to treat seizures and is well-tolerated in humans, including those with HIV. This study supports further investigation of LEV-mediated neuroprotection in HAND.