Islamabad -  Glaucoma is a group of disorders that can cause serious vision impairment. Although there is no known cure, treatment can delay the disease. Emerging research uncovers a new potential treatment option that uses stem cell secretions. Stem cells also secrete exosomes. MSCs have small vesicles enclosed in the membrane of the cell, which are around 30-100 nanometers in diameter and contain messenger RNA and microRNA (miRNA) proteins. These proteins can be carried over to nearby cells when exosomes from one cell fuse with the target cell’s membrane.

The new study - led by Ben Mead, PhD., a post-doctoral fellow at the NEI - set out to isolate the exosomes from bone-marrow derived mesenchymal stem cells (BMSC).

The effects of the isolated exosomes were tested in a rodent model, consisting of rats that had their optic nerve damaged. Researchers injected the stem cell secretions into the rat’s vitreous (the fluid found in the centre of the eye) on a weekly basis.

Before injection, scientists also stained the exosomes with a fluorescent marker. This way, they could track the exosomes and see whether they could successfully deliver their cargo into the inner retinal layers - namely, into the retinal ganglion cells.

Optically injured rats that had been treated with exosomes lost only a third of their retinal ganglion cells, compared with the 90 percent loss found in untreated rats.

The retinal ganglion cells that had been treated with exosomes also continued to function normally, as shown by the electroretinography.

According to the scientists, the protective effects of exosomes are due to the miRNA that stops or alters gene expression. What led the researchers to believe this was that the therapeutic effects of BMSC-derived exosomes significantly decreased after researchers interfered with Argonaute-2, which is a miRNA effector molecule.

However, Stanislav Tomarev, PhD - a principal investigator at the NEI and the study’s co-author - also acknowledges that further research is needed in order to fully understand the exosomes’ specific contents.

Stanislav Tomarev, PhD said that “We need to know which particular microRNA - there are more than 2000 different microRNA molecules - are delivered into the retinal ganglion cells and what proteins or signalling pathways are being targeted upon arrival. We also need to attempt to target exosomes to specific sets of neurons and other cell types or groups of cells.” The authors conclude that their study opens up new possibilities for glaucoma treatment:

“This study supports the use of BMSC-derived exosomes as a cell-free therapy for traumatic and degenerative ocular disease.”

Mead and team explain that using exosomes isolated from stem cells has some advantages over using entire stem cells. As the lead author explains, “Exosomes can be purified, stored, and precisely dosed in ways that stem cells cannot.”

Furthermore, cell-free exosome therapy does not include the risks commonly associated with stem cell transplantation; the body’s immune system cannot reject them and there is no risk of unwanted cell growth. Whether you are not a chicken lover or want to avoid meat because of your bulging belly, you need a balanced diet no matter what. So, in absence of meat you need to play strategically and add more protein to your diet.

If you’re a fan of morning smoothies, go for more than just fruits and vegetables. “Add peanut butter (or another nut butter) into smoothies for an added boost of protein,” says Lewis. “Just make sure it does not have added salts or sugars or hydrogenated oils.” One tablespoon of peanut butter contains four grams of protein alone, which can be a great supplement to your drink and give it lasting power.

Not all of us like to eat Greek yogurt as its own snack, but it can be used a substitution for a variety of other less healthy foods, which can help boost your dish’s protein content. “Use plain Greek yogurt instead of sour cream for recipes,” says Lewis. “The fat is lower, and the protein is higher.” You can also use Greek yogurt as a replacement for heavy cream in baking and as mayonnaise in sandwiches and dressings.

If you’re not familiar with it already, nutritional yeast is deactivated yeast with a nutty and cheesy flavour. It contains a number of vitamins and minerals, including fiber and protein, and it is completely vegan. “Sprinkle nutritional yeast flakes instead of butter, salt or cheese on popcorn,” suggests Lewis.

For added protein without the strong flavour of eggs, consider adding egg whites to dishes that you can thoroughly mix them in. “Add egg whites into oatmeal for an extra protein boost, without an overpowering flavour,” says Lewis. One large egg white contains 3.6 grams of protein, making it a good addition for pastas, rice bowls, and more.

Add these little foods into your daily meals, and you’ll be sure to be eating an adequate diet filled with a good amount of protein.