Oct 11, 2018

Scientists grow human retinas and illuminate eye disease targets

Retinal organoid at 291 days. Red and green cone cells are green in the photo, while blue cone cells are blue. Photo: Johns Hopkins University

Scientists were able to grow human retinas from stem cells for 1 year, allowing them to mimic human fetal development of retinas and closely observe how color-detecting cells form.

Why it matters: The information they gathered could be used to prevent or treat eye diseases and disorders like glaucoma, macular degeneration, color blindness and eye problems from premature births, Johns Hopkins University scientists say in a new study published in Science Thursday.

Background: Retinas are the part of the eye that detects light and determines colors. Humans have 3 types of "cone photoreceptors," which are color-detecting cells that sense red (long wavelength), green (medium wavelength) or blue (short wavelength) light.

What they did: The scientists took stem cells, which have the ability to become any type of cell, and directed them to grow into hundreds of "retinal organoids," so they could monitor the photoreceptor development. Organoids are simplified organs grown in a lab dish from stem cells.

  • Researchers checked their development over the one-year period to see when the different color cones formed.
  • They also used the gene editing technology, CRISPR, to knock out the thyroid hormone receptor in the cone cells at different times. This was done to determine the impact of the hormone as well as to see if the hormone's timing altered development.

What they found: Blue cones form first while red and green cones develop later, study author Kiara Eldred says. "We also found the timing of thyroid hormone exposure is really key to developing the red/green cones and the lack of thyroid hormone is important to developing the blue ones," says Eldred, who's a Ph.D candidate at Johns Hopkins.

  • The researchers hypothesize that the retina contains genes that help control the level of thyroid hormone received via the placenta.
  • Only low levels of thyroid are allowed to come into contact with the blue cones as they are being developed, followed by the activation of genes allowing high levels of the hormone to help develop the red and green cones.

What they're saying: Jay Neitz, professor of ophthalmology at the University of Washington who was not part of this study, says "this is an amazing study" that will open up new research. He notes that its aim is to unlock "the secrets of cellular differentiation and development." 

"[T]hese results open the way to taking a cell from a person with inherited eye disease, repairing the genetic mistake, growing a retina from the person's own repaired cell and transplanting the repaired cells back in the eye to cure a blinding disorder."
— Jay Neitz

What's next: Robert J. Johnston Jr., co-author of the study and assistant professor at Johns Hopkins, tells Axios he hopes the information can lead to multiple therapeutic uses — such as possibly helping premature babies receive enough thyroid hormone to fully develop their red and green cone cells.

  • Johnston also hopes the knowledge will eventually be used to prevent diseases like macular degeneration, which is the leading cause of blindness, as well as glaucoma, which degenerates the retinal ganglion cells.
  • Eldred says she hopes their findings can eventually be used to "inject and enrich the population of cells that need to be replaced" for disease treatment.

Go deeper: Watch Johns Hopkins' video.

Go deeper

Blue Cross Blue Shield insurers sue CVS, alleging drug pricing fraud

Photo: John Lamparski/SOPA Images/LightRocket via Getty Images

Six Blue Cross Blue Shield insurers have sued CVS Health, alleging the pharmacy chain overcharged them based on "artificially inflated prices" for generic drugs and concealed the true cash prices of those drugs.

The big picture: CVS has faced legal scrutiny over its cash discount programs since 2015, and this lawsuit adds big names to a mounting problem.

World coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Axios Visuals

New Zealand has only eight active novel coronavirus cases and no COVID-19 patients in hospital after another day of zero new infections. However, the death toll rose to 22.

Zoom in: A top health official told a briefing a 96-year-old woman "was regarded to having recovered from COVID-19 at the time of her death, and COVID-19 is not recorded as the primary cause of her death on her death certificate." But it was decided to include her in the overall tally of deaths related to the virus.

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 10 p.m. ET: 5,690,951 — Total deaths: 355,575 — Total recoveries — 2,350,071Map.
  2. U.S.: Total confirmed cases as of 10 p.m. ET: 1,699,073 — Total deaths: 100,396 — Total recoveries: 391,508 — Total tested: 15,192,481Map.
  3. Public health: CDC issues guidelines for reopening officesFauci says data is "really quite evident" against hydroxychloroquine.
  4. States: California hospitals strained by patients in MexicoTexas Supreme Court blocks mail-in expansion to state voters.
  5. Business: MGM plans to reopen major Las Vegas resorts in June — African American business owners have seen less relief from PPP, Goldman Sachs says.
  6. Tech: AI will help in the pandemic — but it might not be in time for this one.
  7. World: EU proposes a massive pandemic rescue package.
  8. 1 🎶 thing: Local music venues get rocked by coronavirus.
  9. 🎧 Podcast: Trump vs. Twitter ... vs. Trump.
  10. What should I do? When you can be around others after contracting the coronavirus — Traveling, asthma, dishes, disinfectants and being contagiousMasks, lending books and self-isolatingExercise, laundry, what counts as soap — Pets, moving and personal healthAnswers about the virus from Axios expertsWhat to know about social distancingHow to minimize your risk.
  11. Other resources: CDC on how to avoid the virus, what to do if you get it, the right mask to wear.

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Updated 3 hours ago - Politics & Policy