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Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Tsc22d3 promotes morphine tolerance in mice through the GPX4 ferroptosis pathway
Yan Chen1, Shan Li2, Fenghui Guo3
1Department of Anesthesiology, Children’s Hospital of Hebei Province, Shijiazhuang 050071, Hebei, P.R. China.
Background:
Morphine tolerance refers to gradual reduction in response to drug with continuous or repeated use of morphine, requiring higher doses to achieve same effect.
Methods:
The morphine tolerance dataset GSE7762 profiles, obtained from gene expression omnibus (GEO) database, were used to identify differentially expressed genes (DEGs). Weighted Gene Co-expression Network Analysis (WGCNA) was applied to explore core modules of DEGs related to morphine tolerance. Core genes were input into Comparative Toxicogenomics Database (CTD). Animal experiments were performed to validate role of Tsc22d3 in morphine tolerance and its relationship with ferroptosis-related pathway.
Results:
500 DEGs were identified. DEGs were primarily enriched in negative regulation of brain development, neuronal apoptosis processes, and neurosystem development. Core gene was identified as Tsc22d3. Tsc22d3 gene-associated miRNAs were mmu-miR-196b-5p and mmu-miR-196a-5p. Compared to Non-morphine tolerant group, Tsc22d3 expression was significantly upregulated in Morphine tolerant group. Tsc22d3 expression was upregulated in Morphine tolerant+Tsc22d3_OE, expression of HIF-1alpha, GSH, GPX4 in GPX4 ferroptosis-related pathway showed a more pronounced decrease. As Tsc22d3 expression was downregulated in Morphine tolerant+Tsc22d3_KO, expression of HIF-1alpha, GSH, GPX4 in GPX4 ferroptosis-related pathway exhibited a more pronounced increase. Upregulation of Tsc22d3 in Morphine tolerant+Tsc22d3_OE led to a more pronounced increase in expression of apoptosis proteins (P53, Caspase-3, Bax, SMAC, FAS). The expression of inflammatory factors (IL6, TNF-alpha, CXCL1, CXCL2) showed a more pronounced increase with upregulated Tsc22d3 expression in Morphine tolerant+Tsc22d3_OE.
Conclusions:
Tsc22d3 is highly expressed in brain tissue of morphine-tolerant mice, activating ferroptosis pathway, enhancing apoptosis, promoting inflammatory responses in brain cells.
Insights
Morphine tolerance is linked to increased Tsc22d3 expression in the brain, which activates ferroptosis and apoptosis pathways, leading to inflammation. This study identifies Tsc22d3 as a key player in morphine tolerance development.
Area of Science:
- Neuroscience
- Genetics
- Pharmacology
Background:
- Morphine tolerance is a reduced drug response requiring higher doses with repeated use.
- Understanding the molecular mechanisms underlying morphine tolerance is crucial for developing effective pain management strategies.
Purpose of the Study:
- To identify key genes and pathways involved in morphine tolerance.
- To investigate the role of Tsc22d3 in the development of morphine tolerance and its association with ferroptosis.
Main Methods:
- Differential gene expression analysis of morphine tolerance datasets (GSE7762).
- Weighted Gene Co-expression Network Analysis (WGCNA) to identify core gene modules.
- Validation of Tsc22d3 function through animal experiments, including gene overexpression and knockout models.
- Analysis of ferroptosis-related pathways and apoptosis markers.
Main Results:
- Identified 500 differentially expressed genes (DEGs) enriched in brain development and apoptosis.
- Tsc22d3 was identified as a core gene, significantly upregulated in morphine-tolerant mice.
- Tsc22d3 upregulation correlated with decreased ferroptosis markers (HIF-1alpha, GSH, GPX4) and increased apoptosis and inflammatory factors.
- Tsc22d3 downregulation showed opposite effects on ferroptosis markers.
Conclusions:
- Tsc22d3 is highly expressed in the brain of morphine-tolerant mice.
- Tsc22d3 activation promotes ferroptosis, apoptosis, and inflammation in brain cells, contributing to morphine tolerance.
