A medication used to treat eye diseases may be effective in fighting the ongoing COVID-19 pandemic, according to a new study.
This doesn't mean it can treat COVID-19 but rather that this drug, Verteporfin, can help stop the replication of the SARS-CoV-2 coronavirus, which causes COVID-19 after it infects the body.
The findings of this study were published in the peer-reviewed academic journal PLOS Biology.
How can eye-disease drugs help fight COVID-19?
After it initially infects the body, SARS-CoV-2, continues to replicate, which in turn causes COVID-19 and its variants.
In order to replicate and spread itself, SARS-CoV-2, like all viruses, hijacks the cells and makes use of their signaling pathways.
While commonly thought of as a respiratory disease – and it does severely impact the lungs – COVID-19 also has a wide range of effects on the entire body, including the brain, heart and kidneys.
This means that the spreading and replication process is rather complex, with the virus making use of multiple signaling pathways.
With that in mind, the researchers chose to take a look at one specific signaling pathway, the Hippo pathway. This pathway is important for controlling the size of the body's organs, as well as immune responses and inflammation.
The reason the researchers chose to study this specific pathway is due to previous studies conducted on the Zika virus. When infected with Zika, infants can have smaller brains than normal, which implies that something happened to the pathway that controls the sizes of organs.
Those previous studies on Zika also found that the Hippo pathway may have some virus-fighting ability.
Understanding the Hippo pathway, however, also requires understanding a certain protein called YAP (Yes-associated protein). When the Hippo pathway is activated, YAP activity is inhibited. This is important to understand because it is clear that YAP and the Hippo pathway are linked.
The scientists made use of tissue samples from COVID-19 patients, both the original strain and the Delta variant, and found that the Hippo pathway was activated soon after the infection.
But if YAP was activated, the pathway would shut down. This lets SARS-CoV-2 replicate more. In other words, shutting down the Hippo pathway and boosting YAP activity is something the virus actively tries to do and it helps itself replicate and spread.
That is where Verteporfin comes in.
Verteporfin, sometimes sold under the name Visudyne, is a Food and Drug Administration (US FDA) approved medication used to treat certain eye diseases, especially those related to the production of abnormal blood vessels in the eye.
It has other uses, too, such as blocking some cell proliferation and acting as a defense against fibrosis.
However, Verteporfin is also noted for inhibiting YAP, which is part of its treatment of some eye diseases.
With that in mind, the researchers used Verteporfin to try and block YAP and see if it can help block the replication of SARS-CoV-2 and keep the Hippo pathway active.
And it seems to have worked. According to the study, Verteporfin was able to block the replication of SARS-CoV-2, putting it below detectable levels.
This is also supported by the results of an earlier independent study on a library of 3,200 FDA-approved drugs that could possibly help fight COVID-19. That study noted Verteporfin as a possible antiviral drug against SARS-CoV-2.
Not only do the findings show that Vetreporfin could be useful in fighting COVID-19 but specifically activating the Hippo signalling pathway could be useful for stopping the replication of SARS-CoV-2. This, in turn, could lead to a whole host of pharmacological solutions to the ongoing pandemic.