The study, by researchers at the University of South Carolina's School of Medicine, was performed by injecting laboratory mice with THC and analyzing 609 microRNAs. The researchers identified 13 unique microRNAs that were highly altered by THC.
MicroRNAs have profound effects on the immune system, acting as 'brakes' that target more than 60 percent of all gene expression. Since microRNAs normally suppress the expression of genes, when a microRNA is overexpressed, the affected gene gets silenced. But when microRNA is turned off, the affected gene is expressed at an elevated level.
The authors also studied how a specific microRNA-miRNA-690- that was highly overexpressed in response to THC functionally targets an important protein called C per EBP alpha. This molecule in turn triggers unique cells known as MDSC that suppress inflammation. When the researchers successfully knocked down miRNA-690, the effect of THC was reversed.
The study performed by Dr. Venkatesh Hegde along with others from their team suggested that marijuana can act as a double-edged sword-on one hand suppressing inflammation and thereby increasing susceptibility to certain diseases, while on the other serving as effective treatment modalities against inflammatory and autoimmune diseases.
The study was published in the Journal of Biological Chemistry.