Related Experiment Video
Updated: Dec 26, 2025
Differentiation of a Human Neural Stem Cell Line on Three Dimensional Cultures, Analysis of MicroRNA and Putative Target Genes
Published on: April 12, 2015
Naloxone regulates the differentiation of neural stem cells via a receptor-independent pathway
Jinlong Chen1,2,3,4, Lining Liang1,2,3, Yuan Li1,2,3
1CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences of Guangzhou Medical University, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
Abstract:
The abilities of opioids to activate downstream signaling pathways normally depend on the binding between opioids and their receptors. However, opioids may also function in a receptor-independent manner, especially in neural stem cells (NSCs) in which the expression of opioid receptors and endogenous opioid agonists is low. When two opioids, morphine and naloxone, were used during the early stage of NSC differentiation, increased neurogenesis was observed. However, naloxone methiodide, a membrane impenetrable analog of naloxone, did not affect the NSC differentiation. The abilities of morphine and naloxone to facilitate neurogenesis were also observed in opioid receptor-knockout NSCs. Therefore, morphine and naloxone promote neurogenesis in a receptor-independent manner at least during the early stage. In addition, the receptor-independent functions of opioids were not observed in methylcytosine dioxygenase ten-eleven translocation 1 (Tet1) knockout NSCs. When the expression of opioid receptors increased and the expression of Tet1 decreased during the late stage of NSC differentiation, morphine, but not naloxone, inhibited neurogenesis via traditional receptor-dependent and miR181a-Prox1-Notch-related pathway. In summary, the current results demonstrated the time-dependent effects of opioids during the differentiation of NSCs and provided additional insight on the complex functions of opioids.
Insights
Opioids like morphine and naloxone promote neural stem cell (NSC) neurogenesis independently of receptors early in differentiation. Later, morphine inhibits neurogenesis via receptor-dependent pathways, revealing time-dependent opioid functions.
Area of Science:
- Neuroscience
- Stem Cell Biology
- Pharmacology
Background:
- Opioid signaling typically relies on receptor binding.
- Neural stem cells (NSCs) have low opioid receptor expression, suggesting alternative mechanisms.
- Opioid functions in neurogenesis are complex and not fully understood.
Purpose of the Study:
- To investigate the receptor-dependent and independent roles of opioids in neural stem cell differentiation.
- To determine the temporal effects of opioids on neurogenesis.
- To elucidate the molecular pathways involved in opioid-mediated neurogenesis.
Main Methods:
- Utilized morphine and naloxone on NSCs during early and late differentiation stages.
- Employed opioid receptor-knockout and methylcytosine dioxygenase ten-eleven translocation 1 (Tet1) knockout NSC models.
- Analyzed neurogenesis using specific opioid analogs and molecular pathway investigation.
Main Results:
- Morphine and naloxone enhanced neurogenesis in an early, receptor-independent manner.
- This early effect was dependent on Tet1 expression.
- During late differentiation, morphine inhibited neurogenesis via receptor-dependent pathways involving miR181a-Prox1-Notch signaling.
Conclusions:
- Opioid actions on neurogenesis are stage-dependent.
- Receptor-independent opioid functions in NSCs are significant, particularly early in differentiation.
- Opioids exhibit complex, context-specific roles in neural stem cell development.
