The importance of connection

Patients suffering from the ‘painful blindness’ form of dry eye disease appear to have lost vital connections between cells in their lacrimal glands.

This is suggested by a new study – published in the journal Stem Cells Translational Medicine – that has successfully treated the disease in mice.

Researchers at The Scripps Research Institute, California, injected special types of stems cells into the lacrimal glands of rodents with Sjogren’s syndrome.

The introduction of the cells, which develop into epithelial tissue, meant the mice began to once again produce tears, demonstrating that the treatment had the potential to repair the damaged gland.

Looking closer at the revived glands, the scientists found that the key change was the restoration of the cellular connections between a type of epithelial cell and the gland’s tear-producing cells.

The findings could help to explain why the lacrimal gland, disrupted by aging, pollution or pharmaceuticals, stops its natural regeneration, leading to the aqueous deficiency or ‘painful blindness’ form of dry eye disease.

The research team, including biologist, Dr Helen Makarenkova, said future studies would look at how long the positive effects of the stem cell injections lasted for.

“This is the first step in developing future therapies for the lacrimal gland,” she emphasised.

Dr Makarenkova said the research pioneered a new method to sort the “sticky” epithelial stem cells from other types of cells, using markers to label the desired cells and enzymes to draw them out from the wider tissue.

She told OT that her group had concentrated on sorting the epithelial cells of mice.

“We have not done it, but there is one group in India who made an attempt to sort epithelial cells from human samples,” she explained.

As stem cell transplants are primarily for late-stage disease, the team are also using their findings to search for potential therapeutics that promote lacrimal gland regeneration before this stage, Dr Makarenkova highlighted.