Sunday February 24, 2019

Treating blindness with stem cell therapy

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Stem cells will now treat blindness. Pixabay
Stem cells will now treat blindness. Pixabay

Stem cell-derived retinal cells can now be used to treat age-related macular degeneration (AMD). These advances have been made my a team of scientists led by a person of Indian origin.

Findings

  • Tiny tube-like protrusions called primary cilia on cells of the retinal pigment epithelium (RPE) — a layer of cells in the back of the eye — are essential for the survival of the retina’s light-sensing photoreceptors.
  • This may help scientists to use induced-pluripotent stem cells to create adult RPE for transplants to treat patients with geographic atrophy, otherwise known as dry AMD.

“We now have a better idea about how to generate and replace RPE cells, which appear to be among the first type of cells to stop working properly in AMD,” said lead researcher Kapil Bharti, Stadtman Investigator at the National Eye Institute (NEI), part of the National Institutes of Health.

The results have been incorporated into the group's protocol for making clinical-grade RPE stem cells. Wikimedia commons
The results have been incorporated into the group’s protocol for making clinical-grade RPE stem cells. Wikimedia commons

How they go about it

  • In geographic atrophy, RPE cells die, which causes photoreceptors to degenerate, leading to vision loss.
  • The team hopes to halt the degeneration and reverse the progression of geographic atrophy, by replacing diseased the RPE with lab-made RPE.
  • The team tested three drugs known to modulate the growth of primary cilia on stem cells-derived RPE.
  • However, these RPE cells have a tendency to get developmentally stuck.
  • The cells frequently fail to mature into functional RPE capable of supporting photoreceptors. In cases where they do mature, however, RPE maturation coincides with the emergence of primary cilia on the induced-pluripotent stem cells-RPE cells.
  • They found that the two drugs known to enhance cilia growth significantly improved the structural and functional maturation of the RPE stem cells, while the cells exposed to the third drug, demonstrated severely disrupted structure and functionality.

The results have been incorporated into the group’s protocol for making clinical-grade RPE stem cells, Bharti said.

The study was published in journal Cell Reports. (IANS)

Next Story

Excess Smoking Can Not Just Cause Cancer But Also Blindness

Heavy smokers also have reduced ability to discriminate contrasts and colours compared with non-smokers.

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"Cigarette smoke consists of numerous compounds that are harmful, and it has been linked to a reduction in the thickness of layers in the brain, and to brain lesions, involving areas such as the frontal lobe, which plays a role in voluntary movement and control of thinking, and a decrease in activity in the area of the brain that processes vision," he said. Pixabay

While excessive smoking has been linked to various health issues, including heart disease and cancer, a new study has warned that smoking over 20 cigarettes a day can cause blindness.

The study from the Rutgers University noted that chronic tobacco smoking can have harmful effects on “spatial and colour vision”.

The findings, published in the journal Psychiatry Research, noted significant changes in the smokers’ red-green and blue-yellow colour vision. This suggests that consuming substances with neurotoxic chemicals, such as those in cigarettes, may cause overall colour vision loss.

Heavy smokers also have reduced ability to discriminate contrasts and colours compared with non-smokers.

“Our results indicate excessive use of cigarettes, or chronic exposure to their compounds, affects visual discrimination, supporting the existence of overall deficits in visual processing with tobacco addiction,” said Steven Silverstein from the Rutgers’s Behavioral Health Care.

smoking
Heavy smokers also have reduced ability to discriminate contrasts and colours compared with non-smokers. Pixabay

“Cigarette smoke consists of numerous compounds that are harmful, and it has been linked to a reduction in the thickness of layers in the brain, and to brain lesions, involving areas such as the frontal lobe, which plays a role in voluntary movement and control of thinking, and a decrease in activity in the area of the brain that processes vision,” he said.

For the study, the team looked at 71 healthy people who smoked less than 15 cigarettes in their entire lives and 63 people, who smoked over 20 cigarettes a day. The participants were in the 25-45 year age group.

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The study’s findings showed noticeable changes in the red-green and blue-yellow colour vision of the heavy smokers.

Previous studies had also pointed to long-term smoking as doubling the risk for age-related macular degeneration and as a factor causing lens yellowing and inflammation. (IANS)