Anosmia, the inability to smell, isn't as well-known as blindness or deafness, but it still affects an estimated two million people in the US. A new breakthrough has cured anosmia in mice... and the human impact could be far greater.
Researchers at the University of Michigan Medical School used a specially modified strain of the common cold virus to cure the condition in mice. The virus was loaded up with the desired DNA sequences, and as the infection ran its course through the mice's body their cells were rewritten. By the time the mice had recovered, they were able to smell again. Senior author Dr. Jeffrey Martens explains:
"Using gene therapy in a mouse model of cilia dysfunction, we were able to rescue and restore olfactory function, or sense of smell. Essentially, we induced the neurons that transmit the sense of smell to regrow the cilia they'd lost. At the molecular level, function that had been absent was restored."
This isn't a minor problem — the mice in the study suffered from birth defects that affected a protein known as IFT88. Problems with thiis protein lead to a lack of cilia, the hair-like structures on the body's cells, which in turn makes the mice more likely to have trouble feeding properly and often leads to early death. A similar birth defect occurs in humans, and it's also usually fatal. What's more, cilia dysfunction is also linked to a whole host of other serious diseases, in particularly polycystic kidney disease.
That's actually where the good news comes in — because the researchers have figured out how to solve this particular cilia-related condition, there's now hope that the same strategy can be used to treat even more serious diseases. Admittedly, there's still a long ways to go before this treatment can be applied to humans, and even then it's likely to be of use primarily for people whose anosmia is genetic rather than a result of sinus, aging, or injury. Still, it's a cool result that might lead to a new kind of non-invasive treatment. Besides, it's high time we start making the common cold work for us rather than against us.