Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulation

Background:The discovery of new neurotransmitters is crucial for the in-depth understanding of neural signal transmission, neurological disorders, and relevant treatment strategies. Emerging evidence has indicated that harmine is an important endogenous compound, and its level is closely related to...

Full description

Saved in:
Bibliographic Details
Main Authors: Zhejun Xie, Ning Cao, Manlin Li, Hanxue Wang, Huida Guan, Xuemei Cheng, Changhong Wang
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-07-01
Series:Frontiers in Pharmacology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fphar.2025.1588105/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849425507774365696
author Zhejun Xie
Ning Cao
Manlin Li
Hanxue Wang
Huida Guan
Xuemei Cheng
Changhong Wang
author_facet Zhejun Xie
Ning Cao
Manlin Li
Hanxue Wang
Huida Guan
Xuemei Cheng
Changhong Wang
author_sort Zhejun Xie
collection DOAJ
description Background:The discovery of new neurotransmitters is crucial for the in-depth understanding of neural signal transmission, neurological disorders, and relevant treatment strategies. Emerging evidence has indicated that harmine is an important endogenous compound, and its level is closely related to different physiological and disease states. Inspired by this, we propose a hypothesis that harmine may be a potential neurotransmitter or neuromodulator and display neurotransmitter or neuromodulator-like properties. This study aims to explore the potential properties of harmine as a neurotransmitter or neuromodulator according to the essential criteria for neurotransmitters and neuromodulators.Methods:Candidate proteins for the biosynthesis of harmine were searched by local BLAST. The target protein was then recombinantly expressed, purified, and functionally validated. Subsequently, the release, metabolism, and uptake pathways of harmine were investigated using rat brain synaptosomes and primary neural cells through mass spectrometry analysis. A human proteome microarray was employed to screen for harmine-binding receptors, followed by experimental validation.Results:Adipocyte plasma membrane-associated protein isoform X1 (APMAP-X1) could effectively catalyze the Pictet-Spengler reaction in mammals to generate tetrahydroharmine, which was subsequently oxidized by myeloperoxidase (MPO) to produce harmine. Moreover, harmine could be metabolized, taken up, and released within the synaptic cleft, fulfilling the conditions for clearance and release within the synaptic cleft. Harmine also regulated the expression of neurotransmitter transporters, implying its potential neuromodulatory properties. G protein-coupled receptor 85 (GPR85) and chloride intracellular channel 2 (CLIC2) were receptors targeted by harmine in the central nervous system. Functional verification results confirmed that harmine exerted an inhibitory effect on the GPR85 and could induce cellular depolarization.Conclusion:Current findings provide preliminary evidence that harmine may exhibit neurotransmitter-like properties in certain respects and support its role as an endogenous neuromodulator. However, direct evidence supporting harmine as a neurotransmitter remains limited. Further studies are needed to clarify the precise mechanisms of harmine in neurotransmission. Our study provides a new perspective for researchers on exploring novel endogenous molecules and their significance in neurophysiology.
format Article
id doaj-art-12dbcd8a9ed942f39aabad23effa40f3
institution Kabale University
issn 1663-9812
language English
publishDate 2025-07-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Pharmacology
spelling doaj-art-12dbcd8a9ed942f39aabad23effa40f32025-08-20T03:29:44ZengFrontiers Media S.A.Frontiers in Pharmacology1663-98122025-07-011610.3389/fphar.2025.15881051588105Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulationZhejun Xie0Ning Cao1Manlin Li2Hanxue Wang3Huida Guan4Xuemei Cheng5Changhong Wang6The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, ChinaThe MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, ChinaThe MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, ChinaShanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, ChinaThe MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, ChinaThe MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, ChinaThe MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, ChinaBackground:The discovery of new neurotransmitters is crucial for the in-depth understanding of neural signal transmission, neurological disorders, and relevant treatment strategies. Emerging evidence has indicated that harmine is an important endogenous compound, and its level is closely related to different physiological and disease states. Inspired by this, we propose a hypothesis that harmine may be a potential neurotransmitter or neuromodulator and display neurotransmitter or neuromodulator-like properties. This study aims to explore the potential properties of harmine as a neurotransmitter or neuromodulator according to the essential criteria for neurotransmitters and neuromodulators.Methods:Candidate proteins for the biosynthesis of harmine were searched by local BLAST. The target protein was then recombinantly expressed, purified, and functionally validated. Subsequently, the release, metabolism, and uptake pathways of harmine were investigated using rat brain synaptosomes and primary neural cells through mass spectrometry analysis. A human proteome microarray was employed to screen for harmine-binding receptors, followed by experimental validation.Results:Adipocyte plasma membrane-associated protein isoform X1 (APMAP-X1) could effectively catalyze the Pictet-Spengler reaction in mammals to generate tetrahydroharmine, which was subsequently oxidized by myeloperoxidase (MPO) to produce harmine. Moreover, harmine could be metabolized, taken up, and released within the synaptic cleft, fulfilling the conditions for clearance and release within the synaptic cleft. Harmine also regulated the expression of neurotransmitter transporters, implying its potential neuromodulatory properties. G protein-coupled receptor 85 (GPR85) and chloride intracellular channel 2 (CLIC2) were receptors targeted by harmine in the central nervous system. Functional verification results confirmed that harmine exerted an inhibitory effect on the GPR85 and could induce cellular depolarization.Conclusion:Current findings provide preliminary evidence that harmine may exhibit neurotransmitter-like properties in certain respects and support its role as an endogenous neuromodulator. However, direct evidence supporting harmine as a neurotransmitter remains limited. Further studies are needed to clarify the precise mechanisms of harmine in neurotransmission. Our study provides a new perspective for researchers on exploring novel endogenous molecules and their significance in neurophysiology.https://www.frontiersin.org/articles/10.3389/fphar.2025.1588105/fullharmineneurotransmitterneuromodulatoradipocyte plasma membrane-associated proteincentral nervous systemreceptor interaction
spellingShingle Zhejun Xie
Ning Cao
Manlin Li
Hanxue Wang
Huida Guan
Xuemei Cheng
Changhong Wang
Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulation
Frontiers in Pharmacology
harmine
neurotransmitter
neuromodulator
adipocyte plasma membrane-associated protein
central nervous system
receptor interaction
title Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulation
title_full Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulation
title_fullStr Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulation
title_full_unstemmed Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulation
title_short Exploration of the potential neurotransmitter or neuromodulator-like properties of harmine: evidence from synthesis to synaptic modulation
title_sort exploration of the potential neurotransmitter or neuromodulator like properties of harmine evidence from synthesis to synaptic modulation
topic harmine
neurotransmitter
neuromodulator
adipocyte plasma membrane-associated protein
central nervous system
receptor interaction
url https://www.frontiersin.org/articles/10.3389/fphar.2025.1588105/full
work_keys_str_mv AT zhejunxie explorationofthepotentialneurotransmitterorneuromodulatorlikepropertiesofharmineevidencefromsynthesistosynapticmodulation
AT ningcao explorationofthepotentialneurotransmitterorneuromodulatorlikepropertiesofharmineevidencefromsynthesistosynapticmodulation
AT manlinli explorationofthepotentialneurotransmitterorneuromodulatorlikepropertiesofharmineevidencefromsynthesistosynapticmodulation
AT hanxuewang explorationofthepotentialneurotransmitterorneuromodulatorlikepropertiesofharmineevidencefromsynthesistosynapticmodulation
AT huidaguan explorationofthepotentialneurotransmitterorneuromodulatorlikepropertiesofharmineevidencefromsynthesistosynapticmodulation
AT xuemeicheng explorationofthepotentialneurotransmitterorneuromodulatorlikepropertiesofharmineevidencefromsynthesistosynapticmodulation
AT changhongwang explorationofthepotentialneurotransmitterorneuromodulatorlikepropertiesofharmineevidencefromsynthesistosynapticmodulation