With single gene insertion, blind mice regain sight

[gary]

Researchers at the University of California, Berkeley, have announced that
they have demonstrated that by inserting a gene for a green-light
receptor into the eyes of blind mice, a month later, they were navigating
around obstacles as easily as mice with no vision problems.

Originally Posted by University of California. Berkeley

The researchers say that, within as little as three years, the gene therapy -- delivered via an inactivated virus -- could be tried in humans who've lost sight because of retinal degeneration, ideally giving them enough vision to move around and potentially restoring their ability to read or watch video.

"You would inject this virus into a person's eye and, a couple months later, they'd be seeing something," said Ehud Isacoff, a UC Berkeley professor of molecular and cell biology and director of the Helen Wills Neuroscience Institute. "With neurodegenerative diseases of the retina, often all people try to do is halt or slow further degeneration. But something that restores an image in a few months -- it is an amazing thing to think about."

About 170 million people worldwide live with age-related macular degeneration, which strikes one in 10 people over the age of 55, while 1.7 million people worldwide have the most common form of inherited blindness, retinitis pigmentosa, which typically leaves people blind by the age of 40.

Originally Posted by University of California, Berkeley

In their trials in mice, the UC Berkeley team succeeded in making 90 percent of ganglion cells light sensitive.

Isacoff, Flannery and their UC Berkeley colleagues will report their success in an article appearing online March 15 in Nature Communications.

To reverse blindness in these mice, the researchers designed a virus targeted to retinal ganglion cells and loaded it with the gene for a light-sensitive receptor, the green (medium-wavelength) cone opsin. Normally, this opsin is expressed only by cone photoreceptor cells and makes them sensitive to green-yellow light. When injected into the eye, the virus carried the gene into ganglion cells, which normally are insensitive to light, and made them light-sensitive and able to send signals to the brain that were interpreted as sight.

"To the limits that we can test the mice, you can't tell the optogenetically-treated mice's behavior from the normal mice without special equipment," Flannery said. "It remains to be seen what that translates to in a patient."

In mice, the researchers were able to deliver the opsins to most of the ganglion cells in the retina. To treat humans, they would need to inject many more virus particles because the human eye contains thousands of times more ganglion cells than the mouse eye. But the UC Berkeley team has developed the means to enhance viral delivery and hopes to insert the new light sensor into a similarly high percentage of ganglion cells, an amount equivalent to the very high pixel numbers in a camera.

Story here at ScienceDaily :-
https://www.sciencedaily.com/release...0315095808.htm

"Restoration of high-sensitivity and adapting vision with a cone opsin", by Barry et. al. Nature Communications :-
https://www.nature.com/articles/s41467-019-09124-x

[multiweb (Marc)]

I keep repeating it: green is real and it is good.

[gary]

Originally Posted by multiweb

I keep repeating it: green is real and it is good.

Those three blind mice might be able to successfully evade losing their tails in the near future too.

In a world of bad news lately, the prospect of making some blind people see is certainly hopeful.

[JA]

Thanks for sharing Gary. Great news indeed.

Best
JA

[multiweb (Marc)]

Originally Posted by gary

Those three blind mice might be able to successfully evade losing their tails in the near future too.

In a world of bad news lately, the prospect of making some blind people see is certainly hopeful.

Too right. Unrelated but this is another uplifting story which I found pretty damn cool. Almost to good to be true.

Click here to load the video

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[Wavytone]

There are many congenital defects that deserve to be patched in this way. Patching defects IMHO is entirely rational where it can be shown doing this will produce a better quality of life than the alternatives - or doing nothing.

Starting with various visual defects (I have three, one major two minor), muscular dystrophy, heart defects, and many more. Then there are the tragic ones like Down's syndrome. Many of these wreck the lives of the parents as well as the child.

While in some cases the adults who carry the defective gene these days are encouraged to have children (such as heart defects) on the basis that it can be remedied physiologically (eg surgery), the trouble is the defective gene is still passed on and allowed to spread in the population - whereas if nature was allowed to prevail children with these defects would not reach reproduction.

Hence the real challenge for modern medicine is to stop these defective genes being passed on to successive generations in the first place.

When our son was born I was very worried he would inherit the visual defects I have but thankfully his vision is like his mothers. A 50/50 gamble.

[DarkArts]

Originally Posted by gary

In a world of bad news lately, the prospect of making some blind people see is certainly hopeful.

Yeah, but I'm really not sure it's going to work on our politicians anytime soon ....

[Sunfish (Ray)]

Thanks Gary and Marc for those links. Good news stories are always great.

And as pointed out with politicians , when the education minister for NSW says that STEM is overrated it makes me wonder who put him in charge. Next .

And the feds give all their reef research money away.

Both of my kids are scientists and it makes them seem a little less valued.