The UK reveals a potentially revolutionary way to treat eye injuries and prevent blindness; by softening the tissue hosting the stem cells which then helps repair wounds, inside the body. The team discovered that the simple application of a tissue-softening enzyme, collagenase; prevents the loss of corneal stem cells following an injury and could prevent patients from losing their sight.
It offers hope to almost 500,000 people a year who lose their sight due to chemical burns including acid attacks. The corneal stem cells in a soft environment are fundamental for their reproduction, self-renewal, and ability to heal damaged tissue. This discovery is possible by the development of a sophisticated microscopy technique; which enables imaging the physical properties of biological tissues at very high resolutions.
The layer of the human eye
As the outermost layer of the human eye, the cornea has an important role in focusing vision yet many of the processes; keeping it transparent and resistant to damage are not well. Like skin; the cornea is by a multi-layered epithelium forming a barrier to physical harm and invading microorganisms. But unlike the skin, when the injury occurs the corneal epithelium is repaired by stem cells in the tissue’s periphery; first by quickly dividing in great numbers and then by migrating towards the damaged site as matured epithelial cells; in order to seal the wound.
However, this healing process can compromised when injuries reach the stem cell niche. The research now published has important implications for developing new ways to heal this type of damage. They can now prove that the cornea becomes stiffer when exposing to injuries such as those caused by what is common as acid attacks; demonstrate that wound healing is impaired due to stem cells differentiating in response to the stiffening of their otherwise soft niche; and not because they are killing during injury, as previously thought.
This is an exciting development in the field of corneal biology and allows us to better understand how vision works. But even more important, it provides us with a new set of strategies to treat eye conditions which until now inoperable. They call these less invasive strategies Biomechanical Modulation Therapies.”In the work, the researchers from Newcastle also developed a proof-of-concept therapy to help restore corneal stem cell function and improve tissue regeneration following chemical eye burns.
Effects of chemical burns
Using live corneal tissues as a model system, the team recreated the effects of chemical burns. After treating the wounded, stiffened areas of the cornea using small and localized doses of collagenase; a tissue-softening enzyme to restore the stem cell niche, it once again became pliable and able to support stem cells and promote healing. This collagenase formulation has already approved for related therapeutic applications by both the US Food and Drug Administration and the European Medicine Agency.
The scientists intend to further expand the research, working with health partners to further test the potential of this study. Our research shows that corneal stem cells grow better in softer environments. They now want to build on that knowledge and test this method in patients, using biomechanical modulation therapy to re-create suitable environments for corneal stem cells to thrive within the body whenever their original niche is compromised by injury or disease.
They also think our study is relevant to other scientific and medical fields beyond corneal research; can help the study, diagnostics, and treatment of diseases such as cancer; where tumor stiffening is a known marker of aggressive cancer cell behavior and of metastasis.”