Background: Mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), are present in most gliomas. IDH1 mutation is an important prognostic marker in glioma. However, its regulatory mechanism in glioma remains incompletely understood. Results: miR-182-5p expression was increased within IDH1-mutant glioma specimens according to TCGA, CGGA, and online dataset GSE119740, as well as collected clinical samples. (R)-2-hydroxyglutarate ((R)-2HG) treatment up-regulated the expression of miR-182-5p, enhanced glioma cell proliferation, and suppressed apoptosis; miR-182-5p inhibition partially eliminated the oncogenic effects of R-2HG upon glioma cells. By direct binding to Cyclin Dependent Kinase Inhibitor 2 C (CDKN2C) 3’UTR, miR-182-5p inhibited CDKN2C expression. Regarding cellular functions, CDKN2C knockdown promoted R-2HG-treated glioma cell viability, suppressed apoptosis, and relieved cell cycle arrest. Furthermore, CDKN2C knockdown partially attenuated the effects of miR-182-5p inhibition on cell phenotypes. Moreover, CDKN2C knockdown exerted opposite effects on cell cycle check point and apoptosis markers to those of miR-182-5p inhibition; also, CDKN2C knockdown partially attenuated the functions of miR-182-5p inhibition in cell cycle check point and apoptosis markers. The engineered CS-NPs (antagomir-182-5p) effectively encapsulated and delivered antagomir-182-5p, enhancing anti-tumor efficacy in vivo, indicating the therapeutic potential of CS-NPs(antagomir-182-5p) in targeting the miR-182-5p/CDKN2C axis against R-2HG-driven oncogenesis in mice models. Conclusions: These insights highlight the potential of CS-NPs(antagomir-182-5p) to target the miR-182-5p/CDKN2C axis, offering a promising therapeutic avenue against R-2HG’s oncogenic influence to glioma.
The susceptibility to drug cravings evoked by stimuli poses a formidable hurdle in the treatment of addiction and the prevention of relapse. Pharmacological interventions targeting drug‐associated memories hold promise for curbing relapse by impeding the process of memory reconsolidation, predominantly governed by cAMP signalling. Exchange Protein Activated by cAMP (Epac) serves as a distinctive mediator of cAMP signalling, which has been implicated in reinforcing the effects of cocaine and facilitating the acquisition. Nonetheless, the role of Epac in heroin‐related memory and the subsequent seeking behaviour remains enigmatic. In this study, we explored the impact of Epac activation on the reconsolidation process of drug‐related memories associated with heroin self‐administration. Over the course of 10 consecutive days, rats underwent training, wherein they acquired the behaviour of nose poking to obtain heroin accompanied by a tone + light cue. This nose‐poking behaviour was subsequently extinguished when heroin infusion and cue presentation were discontinued. Subsequently, we administered 8‐pCPT‐cAMP (8‐CPT), an Epac‐specific activator, into the basolateral amygdala at various time points, either in the presence or absence of a conditioned stimulus. Our findings demonstrate that administering 8‐CPT immediately after memory retrieval effectively reduces cue‐ and heroin‐induced reinstatement, with the observed effects persisting significantly for a minimum of 28 days. However, infusion of 8‐CPT for a duration of 6 h following the memory retrieval trial, or without it altogether, had no discernible impact. Thus, these findings strongly suggest that Epac activation can disrupt the reconsolidation of heroin‐associated memory, thereby diminishing the reinstatement of heroin‐seeking behaviour.
The persistence of maladaptive heroin‐associated memory, which is triggered by drug‐related stimuli that remind the individual of the drug's pleasurable and rewarding effects, can impede abstinence efforts. Cyclin‐dependent kinase 5 (Cdk5), a neuronal serine/threonine protein kinase that plays a role in multiple neuronal functions, has been demonstrated to be involved in drug addiction and learning and memory. Here, we aimed to investigate the role of cdk5 activity in the basolateral amygdala (BLA) in relapse to heroin seeking, using a self‐administration rat model. Male rats underwent 10 days of heroin self‐administration training, during which an active nose poke resulted in an intravenous infusion of heroin that was accompanied by a cue. The rats then underwent nose poke extinction for 10 days, followed by subsequent tests of heroin‐seeking behaviour. We found that intra‐BLA infusion of β‐butyrolactone (100 ng/side), a Cdk5 inhibitor, administered 5 min after reactivation, led to a subsequent decrease in heroin‐seeking behaviour. Further experiments demonstrated that the effects of β‐butyrolactone are dependent on reactivated memories, temporal‐specific and long‐lasting on relapse of heroin‐associated memory. Results provide suggestive evidence that the activity of Cdk5 in BLA is critical for heroin‐associated memory and that the specific inhibitor, β‐butyrolactone, may hold potential as a substance for the treatment of heroin abuse.
24 December 2024 in International Journal of Neuropsychopharmacology
Background: Understanding drug addiction as a disorder of maladaptive learning, where drug-associated or environmental cues trigger drug cravings and seeking, is crucial for developing effective treatments. Actin polymerization, a biochemical process, plays a crucial role in drug-related memory formation, particularly evident in conditioned place preference paradigms involving drugs like morphine and methamphetamine. However, the role of actin polymerization in the reconsolidation of heroin-associated memories remains understudied. Methods: This study employed a rodent model of self-administered heroin to investigate the involvement of actin polymerization in the reconsolidation of heroin-associated memories. Rats underwent ten days of intravenous heroin self-administration paired with conditioned cues. Subsequently, a 10-day extinction phase aimed to reduce heroin-seeking behaviors. Following this, rats participated in a 15-minute retrieval trial with or without cues. Immediately post-retrieval, rats received bilateral injections of the actin polymerization inhibitor Latrunculin A (Lat A) into the nucleus accumbens core (NACc), a critical brain region for memory reconsolidation. Results: Immediate administration of Lat A into the NACc post-retrieval significantly reduced cue-induced and heroin-primed reinstatement of heroin-seeking behavior for at least 28 days. However, administering Lat A 6-hour post-retrieval or without a retrieval trial, as well as administering Jasplakionlide prior to memory reactivation did not affect heroin-seeking behaviors. Conclusions: Inhibiting actin polymerization during the reconsolidation window disrupts heroin-associated memory reconsolidation, leading to decreased heroin-seeking behavior and prevention of relapse. These effects are contingent upon the presence of a retrieval trial and exhibit temporal specificity, shedding light on addiction mechanisms and potential therapeutic interventions.
Glioblastoma (GBM) is a highly lethal brain tumor with limited treatment efficacy due to therapy resistance and the blood-brain barrier (BBB). Here, we dev