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Published on: January 12, 2020
Orphanin FQ/nociceptin activates nuclear factor kappa B
Courtney L Donica1, Vanessa I Ramirez, Hibah O Awwad
1Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Ave Suite 323, Oklahoma City, OK 73117, USA.
Summary
Orphanin FQ/nociceptin (OFQ/N) activates nuclear factor kappa B (NFκB) signaling in human neuroblastoma cells. This OFQ/N-induced NFκB activation is NOPr-specific and suggests a mechanism for OFQ/N
Area of Science:
- Neuroscience
- Immunology
- Molecular Biology
Background:
- The endogenous neuropeptide orphanin FQ/nociceptin (OFQ/N) and its receptor, nociceptin orphanin FQ peptide receptor (NOPr), modulate nociception, motor function, learning, and immunity.
- NOPr is an inhibitory G protein-coupled receptor (GPCR) that regulates inflammatory mediators in the central nervous system (CNS) and immune cells.
- Inhibitory GPCRs can activate nuclear factor kappa B (NFκB), a key regulator of immune and CNS responses involved in gene transcription.
Purpose of the Study:
- To investigate whether OFQ/N modulates NFκB activity.
- To determine the effects of OFQ/N on NFκB nuclear accumulation, DNA binding, and transcriptional activation in SH-SY5Y human neuroblastoma cells.
Main Methods:
- SH-SY5Y human neuroblastoma cells were treated with OFQ/N.
- Immunoblotting was used to assess NFκB nuclear accumulation.
- Electromobility shift assay (EMSA) was employed to evaluate NFκB DNA binding.
- NFκB reporter gene assays were conducted to measure transcriptional activation.
Main Results:
- OFQ/N significantly increased NFκB nuclear accumulation (1.9-2.8-fold) and DNA binding (2.9-fold) within 2 hours.
- OFQ/N-induced NFκB activation was dependent on protein kinase C and specific to the NOPr.
- Both NFκB p50 and p65 subunits were stimulated by OFQ/N to bind DNA.
- OFQ/N induced a 2.2-fold increase in NFκB reporter gene transcriptional activity with an EC50 of 6.3 nM.
Conclusions:
- OFQ/N activates NFκB signaling in human neuroblastoma cells.
- This activation involves increased NFκB nuclear translocation, DNA binding, and transcriptional activity.
- The findings suggest a molecular mechanism for OFQ/N's modulatory roles in the CNS and immune system.
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