スタチンによるCovid-19感染へのベネフィット報告多く出現中
25-ヒドロキシコレステロールが関連しているらしい。
At first, his team was simply curious to see which genes are switched “on” in human lung cells in response to SARS-CoV-2 infection.
A gene called CH25H was “blazing hot,” Rana said. CH25H encodes an enzyme that modifies cholesterol. “I got excited because with HIV, Zika, and a few others, we know that CH25H blocks the virus’ ability to enter human cells.”
Here’s what’s happening inside our cells: CH25H’s enzymatic activity produces a modified form of cholesterol called 25-hydroxycholesterol (25HC). In turn, 25HC activates another enzyme called ACAT, found inside cells in the endoplasmic reticulum. ACAT then depletes accessible cholesterol on the cell’s membrane. It’s a normally occurring process that gets kicked into high gear during some viral infections.
The team quickly got to work examining 25HC in the context of SARS-CoV-2 from several angles. They explored what happens to human lung cells in the lab with and without 25HC treatment when they are exposed to first a noninfectious virus that carries the SARS-CoV-2 spike protein (its key to cell entry) or to live SARS-CoV-2 virus itself.
No matter which way they came at it, added 25HC inhibited the ability of the virus to enter cells — blocking infection almost completely.
“The difference between untreated cells and those treated with 25HC was like day and night,” Rana said.
While SARS-CoV-2 uses the ACE2 receptor to initially dock on a cell, Rana’s study suggests that the virus also needs cholesterol (normally found in cell membranes) in order to fuse with and enter the cell. 25HC takes away a lot of that membrane cholesterol, preventing viral entry.
In a similar way, statins are likely beneficial in preventing or reducing the severity of SARS-CoV-2 infection because, while intended to remove cholesterol from blood vessels, they are also removing cholesterol from cell membranes. As a result, the coronavirus can’t get in.
“This is already happening in our bodies on a regular basis, so perhaps we just need to give it a boost, with statins or by other means, to better resist some viruses,” Rana said. “It’s not unlike cancer immunotherapy — the idea that sometimes instead of attacking a tumor directly, it’s better to arm a patient’s immune system to do a better job of clearing away tumors on its own.”
