At Say Hi and Hi&Low, we appreciate the great design being applied to new innovations in cannabis, but we keep in mind that the plant is important for its effects. Cannabinoids, such as THC and cannabidiol, can affect how cells in your body function, the way neurons communicate with each other, or how immune cells respond to inflammatory signals. But did you now that cannabis can have an effect on the genome and, as a result, how your genes are expressed?
Let’s start with a primer on epigenetics. The term “epigenetics” refers to modifications to your DNA that do not change the actual sequence of your DNA, but rather, the physical structure of your DNA. Such modifications involve the addition of various biochemical groups to your DNA or histones, which are proteins around which DNA is wrapped and are essential for the organization of DNA within each of your cells. Think of a classic DNA helix, where that corkscrew shape now has a layer wrapped around it. These modifications can make your DNA either more “open” or “closed” so that specific genes are activated or suppressed, respectively. As we go through our everyday lives, a variety of environmental factors, including diet and exposure to cigarette smoke, can cause significant epigenetic changes[i],[ii].
THC, too, may affect gene expression. In 2014, Yang et al. looked at how epigenetic marks change in immune cells upon THC exposure. Specifically, they looked at two types of immune cells that produce either an inflammatory or anti-inflammatory response. The scientists found that THC had opposing effects on these two cell types- THC suppressed the inflammatory-related genes in one cell type while activating the anti-inflammatory genes[iii] in the other cell type. This study was the first one to show that THC may modulate immune response through epigenetic modifications.
In non-scientific language, what does this mean for cannabis use? The important link here is knowing that the balance between the body’s inflammatory and anti-inflammatory responses is critical to health. Autoimmune diseases like rheumatoid arthritis and Crohn’s disease, as well as inflammatory diseases like asthma are characterized by a dominant inflammatory response[iv],[v]. If cannabis is able to shift the immune balance to an anti-inflammatory state, this would suggest that, in addition to its current medical use in the treatment of inflammation, cannabis could be a potential therapy for autoimmune and inflammatory diseases. More research has to be done in order to show this conclusively, but the results so far are cause for optimism.
[i] Jaenisch R and Bird A. Epigenetic regulation of gene expression: how the genome integrates intrinsic and environmental signals. Nat Genet. 33 Suppl:245-54. 2003.
[ii] Lee KWK and Pausova Z. Cigarette smoking and DNA methylation. Front Genet. 4:132. 2013.
[iii] Yang X et al. Histone modifications are associated with D9-tetrahydocannabinol-mediated alterations in antigen-specific T cell responses. J Biol Chem. 289(27):18707-18. 2014
[iv] Gerli R et al. Roles of CD30+ T cells in rheumatoid arthritis: a counter-regulatory paradigm for Th1-driven diseases. Thrends Immunol. 22(2):72-77. 2001.
[v] Nemeth et al. Crohn’s disease and ulcerative colitis show unique cytokine profiles. Cureus. 9(4):e1177. 2017.