http://www.eurekalert.org/pub_releases/2016-01/cmc-get010716.php

Public Release: 7-Jan-2016
Gene editing technique improves vision in rats with inherited blindness

Data show the new 'CRISPR/ Cas9' system potentially can be used to
prevent retinal Damage in a type of retinitis pigmentosa, one of the
most common inherited disorders of the retina

Cedars-Sinai Medical Center

LOS ANGELES (Jan. 7, 2016) -- A new technique that has the potential to
treat inherited diseases by removing genetic defects has been shown for
the first time to hinder retinal degeneration in rats with a type of
inherited blindness, according to a Cedars-Sinai study.

A research team at the Cedars-Sinai Board of Governors Regenerative
Medicine Institute focused on inherited retinitis pigmentosa, a
degenerative eye disease with no known cure that can lead to blindness.
The researchers used a technique known as CRISPR/Cas9 to remove a
genetic mutation that causes the blindness disease. CRISPR/Cas9 is
adapted from a strategy used by bacteria to fight invading viruses.

Although the study involved rats, it is an important milestone because
of its potential implications for humans.

"Our data show that with further development, it may be possible to use
this gene-editing technique to treat inherited retinitis pigmentosa in patients," said Shaomei Wang, MD, PhD, a research scientist in the
institute's Eye Program and associate professor of Biomedical Sciences.
Wang was the senior author of the study, published in the journal
Molecular Therapy.

Retinitis pigmentosa is a class of diseases in which patients experience
night blindness in the early stages, along with atrophy and pigment
changes in the retina, constriction of the visual field and eventual
blindness, according to the National Institutes of Health. While rare
overall, it is one of the most common inherited diseases of the retina, affecting about 1 in 4,000 people in the U.S. and Europe.

CRISPR/Cas9, the technique that Cedars-Sinai scientists used to target retinitis pigmentosa, has been in use by genetic researchers for less
than five years. In that time, it has transformed the science of genome
editing by making the process easier, more dependable and less
expensive.

The technique is adapted from a system that bacteria deploy to disable
invading viruses. The bacteria first copy part of the invader's genetic
code into a special sequence of ribonucleic acid (RNA), which acts a
messenger to carry out the code's instructions. When the virus returns,
the RNA binds to a protein called Cas9, guiding it to the matching gene
in the virus. The protein disables the gene.

By modifying this system, scientists can program Cas9 to turn selected
genes on or off, or rewrite the genetic code. (CRISPR stands for
Clustered Regularly Interspaced Short Palindromic Repeat, the type of
DNA sequences involved in this process.)

In the study, the Cedars-Sinai researchers designed a CRISPR/Cas9 system
to remove a mutated gene that causes photoreceptor cell loss in the eye.
They injected this system into young laboratory rats that had been
engineered to model a type of inherited retinitis pigmentosa known as
autosomal dominant, which involves this mutated gene.

After a single injection, the rats were able to see better compared with controls, as measured by optomotor reflex, which involves turning the
head in response to moving stripes of varying degrees of brightness.

Clive Svendsen, PhD, a co-author on the study, said the effectiveness
and consistency of these results may be improved by modifying elements
of the CRISPR/Cas9 system and using new viral delivery techniques. In
the future, after more research, he believes that reliable genome
editing through this system may provide a means to correct a wide range
of inherited diseases in patients.

"This is the first time CRISPR/Cas9 gene editing has been used to
prevent vision loss in a living animal. It is a truly remarkable result
and paves the way for more exciting studies and translation to the
clinic in the future," said Svendsen, director of the Board of Governors Regenerative Medicine Institute and the Kerry and Simone Vickar Family Foundation Distinguished Chair in Regenerative Medicine.

###

Besides Svendsen and Wang, other key authors on the study included
Benjamin Bakondi, PhD; Wenjian Lv, PhD; Bin Lu, MD, PhD; Melissa K.
Jones, MS, Yuchun Tsai, PhD; Kevin J. Kim, PhD; Rachelle Levy, BS; Aslam
Abbasi Akhtar, MS; and Joshua J. Breunig, PhD.

Financial support for this research was provided by the Cedars-Sinai
Board of Governors Regenerative Medicine Institute, Fight For Sight
Foundation and the National Eye Institute of the National Institutes of
Health under award number EY020488.



--
Please sign and share

Remove the prosecution rights of the RSPCA - Petitions https://petition.parliament.uk/petitions/109469

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)