Mesenchymal Stem Cells Reversed Morphine Tolerance and Opioid-induced Hyperalgesia

Area of Science:

• Neuroscience
• Regenerative Medicine
• Pharmacology

Background:

• Opioid therapy, while common for pain, leads to opioid tolerance (OT) and opioid-induced hyperalgesia (OIH), limiting efficacy and safety.
• Neuroinflammation in the spinal cord is implicated in the development of OT and OIH.
• Current strategies to prevent or treat OT and OIH are limited, posing a significant medical challenge.

Purpose of the Study:

• To investigate the potential of mesenchymal stem cells (MSCs) to attenuate or reverse opioid tolerance and opioid-induced hyperalgesia.
• To explore the therapeutic effects of MSC transplantation (MSC-TP) in preclinical models of opioid-induced complications.

Main Methods:

• MSCs were administered intravenously or intrathecally to rats and mice before or after repeated morphine administration.
• Opioid tolerance and hyperalgesia were assessed in the animal models.
• Immunohistochemistry was used to evaluate the levels of microglial and astrocyte activation in the spinal cord.

Main Results:

• MSC-TP, administered before morphine, effectively prevented the development of OT and OIH.
• MSC-TP, administered after morphine, significantly reversed established OT and OIH.
• Treatments reduced the activation of microglia and astrocytes in the spinal cord.
• No abnormalities were observed in the vital organs or functions of the treated animals.

Conclusions:

• Mesenchymal stem cell transplantation demonstrates potential as a safe and effective strategy for preventing and reversing opioid tolerance and opioid-induced hyperalgesia.
• MSC-TP's mechanism involves mitigating neuroinflammation in the spinal cord.
• This approach offers a promising therapeutic avenue for improving the safety and efficacy of long-term opioid therapy.