Re: Good news towards retina regrowth!
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While this is a nice result, I do not think it is yet on a path for human trials. Organoids are really useful for studying normal development. Previously it was shown that retinal organoids make three cell types that are in a retina. Here they show that these cell types connect to each other. ? But this is still very far away from being an operational retina. Real retinas have specific connections between the photoreceptors and multiple types of interneurons; the interneurons in turn have complex connections to each other, and to the retinal ganglion cells. ? In addition, it is a big problem to get the retinal ganglion cells to grow axons far into the brain to make the right connections. That is not addressed in this paper at all.? Also, we NIAON folk are missing some of our retinal ganglion cells¡ªI think we still have the interneurons and photoreceptors. ?? ? Finally, it is probably not wise to inject human embryonic stem cells into people. For one thing, they are from another person (immune response) For another, they are designed to have a lot of developmental plasticity (so you have to worry about them differentiating into unwanted cell types, including cancer). ? So while this shows that retinal organoids are a good system for learning about normal development, this is still very far from a therapy. ? Please think very carefully before participating in stem cell clinical trials. There is a bad history here, for eye disease in particular. ? ? Adam ?
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From: [email protected] < [email protected]> On Behalf Of Deane Williams Sent: Monday, January 09, 2023 8:54 PM To: [email protected]Subject: Re: [NAION] Good news towards retina regrowth! ? No, not available. Maybe human trials in the next few years. On 1/9/2023 8:46 PM, carlo maglione via groups.io wrote: So where can I have this done? Is this treatment available at this time?
On Monday, January 9, 2023, 12:09 PM, Deane Williams <pyroartist@...> wrote: From a January 4th paper comes good news towards eye regeneration.
They do not specifically mention the optic nerve but they may
be working towards that as they mention glaucoma.
We may be another step closer.
Dean As we mammals get older, many?of us start to lose our eyesight because the neurons in our retinas degenerate.? Our retinal ganglion cells might get attacked by glaucoma, or our rods and cones (photoreceptors) might get eroded by macular degeneration or retinitis pigmentosa.? Somewhere in the course of evolution, we lost our ability to regenerate those kinds of cells, just like we lost the ability to regenerate limbs.? Once they¡¯re gone, they¡¯re gone. But we humans did develop some other things really well:?the ability to use reason and the desire to sustain ourselves.? And those attributes have brought us to the verge of making up for some of our evolutionary shortcomings.? It¡¯s amazing enough that grow human stem cells into retinal ¡°organoids¡± ¡ª?little balls that all the different types of cells it takes to make a functioning retina, even organized into the right layers. But now we¡¯ve?learned that if we break up the organoid into individual cells, those cells are?capable of spontaneously forming signal-communicating connections ()?with other retinal cells.? That means that a patient could have their own stem cells grown into retinal cells and applied to their own retina, these new cells could functionally replace the old, and vision could be restored.? No gene therapy required, thanks very much. You can read all about this last hurdle being at the University of Wisconsin labs of Drs. David Gamm and Xinyu Zhao in the January 4 issue of the Proceedings of the National Academy of Sciences. For more info with diagrams and pictures:
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