Regenerative Properties of Zebrafish Show Potential in Treating Retinal Deterioration

The human body can naturally regenerate certain tissues and cells accurately. Experts in regenerative biology are currently finding ways to control the regenerative capacity of humans in a way that will benefit the other parts of the body.

Utilizing Nanoparticles Against Degeneration

Researchers from the Wilmer Eye Institute discovered the potential of nanoparticles in targeting immune cells in the eyes of zebrafish and their effectiveness in enhancing the rate of neuron degeneration after injury. It expands previous studies which show the regulation of retinal cell regeneration in zebrafish and mice models using immune cells or microglia.

The study focuses on using nanoparticles to target and deliver an immunosuppressant drug to active microglia in degenerating zebrafish retinas. It was an effective strategy in dosing and stimulating the regeneration of lost retinal cells.

The process dramatically speeds up regeneration, about twice as fast as the drug itself. This was confirmed by corresponding author Jeffrey Mumm together with Helen Larson and Charles Glenn Grover.

In the research, an immunosuppressant drug called dexamethasone was attached to the nanoparticle dendrimer. This nanoparticle was previously developed at Wilmer in collaboration with Kannan Rangaramanujam. The nanoparticle delivered the drug payload to activate immune cells in the retinas of zebrafish, suppressing the activity of the cell.

According to the researchers, this suppression plays a significant role in improving the rates of neuron regeneration through an adaptive optics-corrected lattice light sheet microscope. This special imaging system allowed the researchers to capture the images of the zebrafish fisheye in almost real time.

Dendrimers offer an accurate targeting tool by providing medications directly to the body's immune system. They allow the researchers to modify the activities of immune cells while preventing the negative effects of powerful immunosuppressants. According to Mumm, the technique can be compared to using a scalpel in testing the impact of immune suppression rather than using a sledgehammer.

Currently, this technique has not yet been tested in mammals and humans, but Mumm hopes to utilize its potential to restore vision rather than prevent the loss of vision. The team is confident that the therapeutic strategy will be transformative for people who lost their vision and suffer from other eye conditions.

Regenerative Properties of Zebrafish

Zebrafish (Danio rerio) is a freshwater fish from Southeast Asia that belongs to the minnow family. This tropical animal possesses a genetic structure that is surprisingly similar to that of humans. Because of this, they are a suitable model for research studies about the development of vertebrates.

Unlike mammals, zebrafiscanto regenerate a damaged retina by releasing Wnt and heparin-binding epidermal-like growth factor (HB-EGF) signaling pathways. Their body also triggers a series of changes where Muller glial retinal cells are reverted to a stem-cell state. While they are in this state, new cells are generated to repair the damage in the retina.

Aside from the retina, other damaged organs can also be regenerated by zebrafish, including the spinal cord, heart, fin, and brain. This makes the animal a good model for studying cancers, muscular dystrophy, and congenital disabilities.