New Research Shows Odors Can Alter Gene Expression, Opening Potential for Medical Treatments
Ever since the COVID-19 pandemic kicked off, we’ve been far more aware of our sense of smell. Now, new research shows that odors – like those emanating from ripening fruits or fermented foods – can lead to changes in how genes are expressed inside cells far beyond the nose.
The findings have scientists wondering if, with much more research, sniffing volatile, airborne compounds could be a way to treat cancer or slow neurodegenerative disease.
A Surprising Discovery
“That exposure to an odorant can directly alter [the] expression of genes, even in tissues that have no odorant receptors, came as a complete surprise,” says Anandasankar Ray, a cell and molecular biologist at the University of California (UC) Riverside and senior author of the study.
To investigate this phenomenon, the research team exposed fruit flies and mice to different doses of diacetyl vapors over a period of five days. Diacetyl is a volatile compound released by yeast during the fermentation process of fruits. It was historically used to impart a buttery-like aroma in foods like popcorn and is sometimes present in e-cigarettes. The compound is also a by-product of brewing.
The researchers found that diacetyl can act as a histone deacetylase (HDAC) inhibitor in lab-grown human cells. HDACs are enzymes that help wrap DNA more tightly around histones, thereby regulating gene expression. By inhibiting HDACs, diacetyl allows genes to be expressed more readily. HDAC inhibitors are already being used as treatments for blood cancer.
Promising Results
In subsequent experiments, the team discovered that diacetyl vapors halted the growth of human neuroblastoma cells and slowed the progression of neurodegeneration in a fly model of Huntington’s disease. These findings suggest that volatile compounds emitted from microbes and food can alter epigenetic states in neurons and other eukaryotic cells.
However, the researchers acknowledge that diacetyl may not be the perfect candidate for therapy due to its potential health risks. Inhaling diacetyl has been linked to changes in airway cells and a lung disease called obliterative bronchiolitis, also known as ‘popcorn lung.’
Future Directions
Despite the limitations of the study, such as the lack of a thorough analysis of the underlying mechanisms and the scope limited to lab-based, preclinical research, the findings open up new considerations for evaluating the safety of volatile chemicals that can cross the cell membrane.
Anandasankar Ray and his team are already working on identifying other volatiles that lead to changes in gene expression. Their goal is to explore the potential of volatile compounds in treating various diseases and conditions.
Beyond Medical Applications
Perhaps a more practical application of this research lies in agriculture. Plants also contain HDAC enzymes, and previous studies have shown that they exhibit a strong and sudden response to volatile chemicals in the air. Understanding how odors can alter gene expression in plants could have significant implications for improving crop yields and plant health.
In conclusion, this groundbreaking study reveals the surprising connection between odors and gene expression. While there is still much more research to be done, these findings pave the way for potential medical treatments and advancements in agriculture. The ability to manipulate gene expression through volatile compounds opens up a whole new world of possibilities for improving human health and understanding the intricate workings of nature.
