5 November, 2024
Hot Off The Press
More updates on the latest research:
We have just about got our heads around the CRISPR-Cas9 system which is widely used to splice and alter bits of defective DNA in IRDs (Inherited Retinal Disorders) and many other inherited genetic disorders…. well now the next best thing seems to be the CRISPR-Cas13 system which targets the RNA instead of the DNA. RNA messengers read a specific bit of DNA and take that exact recipe to direct the building of proteins for the body. The Cas-13 system can potentially change the defective gene on the messenger RNA either while it is transcribing the message from the DNA, or while it is delivering it to the protein manufacturing system. In combination with artificial intelligence the boffins seem very excited about this development. “…..CRISPR-Cas13 could pave the way for a new era of RNA-targeted therapies.” they say…. such as diagnostics for RNA viruses, RNA imaging, RNA-base editing, RNA epigenome editing, and therapeutic interventions.
We all carry billions of genes on our DNA, most of which are translated into building blocks for the body, but the body suppresses the expression of some genes, and for the nasty genes, this is a good thing. Epigenetics studies why and how the body suppresses or activates our genes, in the hope that we might be able to exert some control over the process ourselves.
Epigenetic factors have been identified already in several types of cancer, as well as parkinson’s disease, schizophrenia and major depression. It may be that epigenetics also has an influence on who develops IRDs, and to what degree people are affected. It’s all to do with methylation of genes, and modification of histones, so the clever people tell us.
It seems that childhood adversity and stress make us more vulnerable to the nasty effects of epigenetics, but yet again, a healthy diet and lots of exercise is protective for us. That is something simple that we can all understand and do better!
TnpB Proteins are the ancestor of the CRISPR-Cas systems. Both are “genetic scissors” used to alter genes. The TnpB Proteins were abandoned previously because they were less efficient than the Cas systems. However, as the TnpB proteins are small and compact, it is easier to transport more of them into the cell nucleus via viral vectors than the bigger Cas proteins.
Scientists have recently been able to upgrade the efficiency of the TnpB proteins, so suddenly they are potentially interesting and useful again.
You’ll like this one! “Eating pistachios can help prevent AMD”!
They have a lot of lutein in them which is a powerful antioxidant. The lutein improves the retinal pigment density which in turn protects the retina from blue light and AMD. A study where people were given 57g pistachios a day, increased the retinal pigment density within in 6 weeks, and was expected to reduce the risk of developing AMD (Aged related macular degeneration).
Interestingly the study chose subjects who didn’t have great diets and who were deficient in lutein…. So presumably if you eat nuts and seeds anyway, your eyes would already be protected…..
Lutein crosses the blood/brain barrier, so it probably helps protect the brain against oxidative stress too…… win win.
So it’s that old chestnut again….. eating a wide variety of whole foods including pistachios (!)…helps reduce the impact of disease including AMD.
Broad spectrum therapies for RP?
Retinitis pigmentosa (RP), is a group of genetic disorders which lead to progressive visual loss. As there is a lot of genetic diversity in the group, it has been difficult to treat the genes directly. However, the many gene mutations lead to common pathways to cell destruction, and it is these pathways which can perhaps be targeted with broad spectrum treatments in the future. Some key retinal proteins and pathways have already been identified and shared to the research community with a view to developing these treatments.
Lipofuscin in Dry AMD and Stargardt’s
Interestingly, both dry AMD and Stargardt’s have similar disease processes. They both involve “lipofuscin” accumulation in the retina which presents as yellow/brown pigment granules. This lipofuscin contains bisretinoids which kill cells leading to early loss of vision in Stargardt’s, and later onset with dry AMD. A new treatment which is being developed aims to prevent the build-up of the bisretinoids, and so help to prevent both diseases. More good news is that the new treatment should be able to be taken by mouth rather than as another eye injection which will make it easier to manage for everyone.
That’s all folks, till next time.
Who knows what will pop up next?
It’s all happening
Cathy
Guest writer – Dr Catherine Civil
My name is Dr Catherine Civil. I have been associated with Retina Australia since the early 2000s. At that time, they were called WARPF, or the WA Retinitis Pigmentosa Foundation. WARPF were raffling a car in a shopping centre, and it caught my eye because my dad and my uncle both had Retinitis Pigmentosa. Being a doctor and a parent, I had a particular interest and awareness, not just of the disease, but of the fact that there was a significant risk that I or my children or my relatives might have inherited it.
I turned up at an AGM and found myself on the Board and engaged in fundraising. I spent several years on the Board and met some wonderful people, and I was even Chairman for a couple of years. When I left, I started writing the “Hot off the Press” research update column for the newsletter.
I arrived from the UK in the early 1990s with my husband and twin baby girls to live in Perth for a year for a bit of sunshine and fun, and we find ourselves still having fun in WA 30 years later, and with a grown son as well.
