IBS GRANADA scientists achieve that white blood cells relieve pain, instead of producing it, during tissue inflammation
Researchers at ibs.GRANADA lead a novel study in mice that shows that sigma-1 receptor blocking drugs make leukocytes or white blood cells relieve pain felt when tissue is inflamed. His work is published this week in the prestigious magazine PNAS, according to the UGR.
The cells of the immune system, leukocytes or white blood cells, accumulate in the tissues of the human body after, for example, suffering a trauma or an injury. Its main function is to repair this damaged tissue. However, in addition to this repair function, these cells produce certain substances that promote pain (called allergens), which is why they play a key role in the pain felt when the tissue is inflamed. This is also applicable to certain chronic pathologies that present with inflammation and pain, as in the case of arthritis.
Paradoxically, these leukocytes, in addition to releasing allergens, are capable of producing endogenous opioid peptides (such as endorphins). These peptides have the same activity as opioid analgesics (drugs to treat severe pain, such as morphine), which have been used for millennia to treat pain. However, the balance between leukocyte activity for and against pain during inflammation clearly favors pain; in fact, inflammation causes pain.
Role of the sigma-1 receptor in inflammatory pain. (A) Leukocytes present in the inflamed area release pain-contributing allergens, along with endogenous opioid peptides. These opioid peptides do not relieve pain because the sigma-1 receptor stops opioid receptors from working. (B) Sigma-1 blockers unblock opioid receptor function, resulting in pain relief. UGRDIVULGA
The sigma-1 receptor is a very small protein present in neurons, and it is capable of modulating the action of opioid receptors. In a study led by scientists from the University of Granada, it has been discovered that sigma-1 receptor blockers are capable of increasing the effect of these endogenous opioid peptides produced by leukocytes, so that these cells of the immune system when they are in the inflamed tissue relieves pain rather than causing it.
The researchers belong to the Department of Pharmacology of the UGR, the ibs.GRANADA and the Institute of Neurosciences of the Center for Biomedical Research, which have carried out the study together with the Esteve pharmaceutical company, the Teófilo Hernando Institute of Drug R&D, and the Austrian Institute for Molecular Biotechnology.
"We are dealing with a completely novel pain relief mechanism, based on maximizing the analgesic potential of immune system cells, which could have important therapeutic applications in patients with inflammatory pain," says the director of this study, Enrique J. Cobos del Moral, a researcher from the Department of Pharmacology and Institute of Neurosciences at the University of Granada.
This research work has been possible thanks to the Reincorporation of Doctors Program of the Vice-Rectorate for Research and Transfer of the UGR.
