CHARACTERIZATION OF FRONTAL CORTICAL CIRCGRIN2B_011731 IN OPIOID-INDUCED NEUROADAPATIONS

Opioid use disorder (OUD) is chronic relapse neurological disorder, best characterized by profound drug-induced neuroadaptations which drive drug-seeking phenotypes and persist in the absence of drug. In this dissertation we will examine circular RNA (circRNA) dysregulation following a rodent model of heroin self-administration and characterize a novel circRNA pathway regulating opioid induced neuroadaptations. We identified 76 circRNAs regulated by heroin self-administration, of these we selected circGrin2b_011731 (circGrin2b) for further characterization. circGrin2b is derived from exon 3 of linear Grin2b, which encodes the regulatory subunit of the NMDA receptor, GluN2b, a protein essential for opioid learning and memory paradigms. First, using a custom small-interfering RNA (siRNA) targeting the backsplice junction of circGrin2b, we show that knock-down of orbitofrontal cortex (OFC) circGrin2b significantly reduces heroin intake during self-administration, while only non-significantly reducing heroin-seeking phenotypes. This suggests that OFC circGrin2b is functionally relevant to heroin self-administration phenotypes. Next, we utilized an in vitro primary cortical culture morphine exposure model to interrogate putative upstream biogenesis mechanisms and examine expression of potential circGrin2b microRNA (miRNA)-sponge targets. We validated circGrin2b interactions with miR-26b-3p and miR-100-3p utilizing a luciferase binding assay. Sponging of these 2 miRNA targets can have extensive impact of translation of miRNA-repressed genes, as both miRNAs are involved in regulation of messenger RNAs involved in opioid signaling. Taken together, this dissertation characterized the behavioral and molecular role of a novel circRNA species in mediating opioid-induced neuroadaptations and expands upon the current understanding of the role of circRNAs in regulating synaptic plasticity.

Grantor dc:publisher

Temple University. Libraries

Year dc:date.issued

2024

Author dc:creator

• Gillespie, Aria

Advisor dc:contributor.advisor

• Daws, Stephanie

Committee members dc:contributor.committeemember

• Kirby, Lynn
• Langford, Dianne
• Rom, Slava
• Raghupathi, Ramesh

• Molecular biology
• Biology
• Neurosciences
• Circular RNA
• Grin2b
• Heroin
• Opioid use disorder

Statement dc:rights

• IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/20.500.12613/10923

OAI identifier oai:identifier

oai:scholarshare.temple.edu:20.500.12613/10923