Cyagen Biosciences

Blindness is a major public health problem. Nearly 40 million people worldwide are functionally blind, while over 250 million people suffer from visual impairment. The major causes of both acquired and hereditary blindness in the developed world are age-related macular degeneration and retinitis pigmentosa, which both share a common pathophysiology. In these conditions, the photoreceptors of the outer retina degenerate irreversibly, leaving the inner retina intact but unable to process visual input. Due to the anatomical and physiological similarities between visual systems across mammalian species, rodent models are incredibly powerful tools for the testing and development of therapies to treat blindness. Here are a few examples of how mouse models are being used to give sight to the blind. AAV-based gene therapy was used by Cehajic-Kapetanovic and colleagues to introduce a human rhodopsin gene into the cells of the inner retina in a mouse model of retinitis pigmentosa (hereditary ...

It has long been known that cells acquire mutations over time. In fact, ongoing random mutation rates are such that no two cells in a human body are identical. Unlike most cell types, which die and are frequently replaced, human neurons can live for decades, carrying on their functions for the entire lifetime of the organism. We know that mutations must accumulate in neurons over their long lifespan, but until now we had no clear picture of the frequency or pattern of neuronal mutations. Using the seemingly impossible approach of sequencing genomes of individual human brain cells, a group of researchers have now shown that the average human neuron carries a whopping 1700 mutations per neuron. These neuroscientists, based at Harvard and MIT, sorted individual neurons from the postmortem brains of three individuals, amplified their genomic DNA, and were able to use whole-genome sequencing to obtain individual cell genome sequences at ~40x coverage. In addition to the sheer number of neur...

Stem cells taken from muscle tissue could promote better blood flow in patients with diabetes who develop peripheral artery disease, a painful complication that can require surgery or lead to amputation. A new study in mice at the University of Illinois found that an injection of the stem cells prompted new blood vessels to grow, improving circulation in the affected tissues and function in the affected limbs. The stem cells also induced changes in gene expression in the surrounding tissues, prompting the release of factors to reduce inflammation and increase circulation. The study was published in the journal  Theranostics . "PAD is very common in diabetic patients, but it is difficult to diagnose because patients experience symptoms when the disease is already at an advanced state," said study leader Wawrzyniec Lawrence Dobrucki, a professor of bioengineering and of medicine and head of the Experimental Molecular Imaging Laboratory at the Beckman Institute for Adv...

A U of G researcher is the first to discover the type of stem cell that is behind the gecko's ability to re-grow its tail, a finding that has implications for spinal cord treatment in humans. Many lizards can detach a portion of their tail to avoid a predator and then regenerate a new one. Unlike mammals, the lizard tail includes a spinal cord. Prof. Matthew Vickaryous found that the spinal cord of the tail contained a large number of stem cells and proteins known to support stem cell growth. "We knew the gecko's spinal cord could regenerate, but we didn't know which cells were playing a key role," said Vickaryous, lead author of the study recently published in the  Journal of Comparative Neurology . "Humans are notoriously bad at dealing with spinal cord injuries so I'm hoping we can use what we learn from geckos to coax human spinal cord injuries into repairing themselves." Geckos are able to re-grow a new tail within 30 days -- faste...