We just took a massive step towards growing human limbs in the lab

17 May 2018

Image: PolakPhoto/Shutterstock

Attempting to secure an organ or limb donation can be a challenging ordeal for a patient, but a major breakthrough could help get them an artificial one much quicker.

Despite the major advances in our understanding of the human body, we have yet to successfully and clinically produce artificial human organs and limbs for transplant into a patient.

If it were to be achieved, however, we would find ourselves in the dawn of a new age of medicine, given that patients in need of a transplant would no longer be left waiting for a donor organ or limb, which might not even reach them in time.

So, it is welcome news that a team of researchers from Oregon State University has combined developmental biology, genetics and bioinformatics to find the key to creating human organs in the lab.

In a paper published to Scientific Reports, the team discovered that precursor cells for skeletal muscles actually also give rise to neurons, blood vessels, blood cells and immune cells.

The engine comparison

Using a mouse embryo model, Chrissa Kioussi and her team analysed Pax3+ cells, which act as a multifaceted stem cell niche for multiple organs at embryonic stages.

By studying profiles of the cell population over the course of several days, the team isolated lineage-traced cells from forelimbs at different embryonic days and performed whole-transcriptome profiling via RNA sequencing.

This enabled the team to identify the genes involved in the development of muscular, skeletal and nervous systems, all of which go into the making of a functional limb.

“An engine has so many little parts, and you can’t fix a broken engine if you don’t know what all of these little parts do,” she said.

“Likewise, you can’t make a limb if you don’t know about all of the cell parts within the limb. You can’t use only bone or only muscle or only veins – you need everything working together.”

A prelude to growing body parts

It became apparent that the expression of these genes increased over time during the tests, suggesting that Pax3+ cells not only allow for muscles to develop, but are involved in the patterning and the 3D formation of the forelimb through multiple systems.

This opens the door to the potential use of stem cell pockets to grow a new arm, leg or organ for someone who has lost a body part to accident or disease.

“[The cell population is] a great source we have to fix different organs with issues from injury, toxicity from drugs – anything that can generate cell death in any part of our body,” Kioussi said.

“A genetic program that runs during embryogenesis normally generates adult cell types. We can identify these cells and be able to generate not one but four different organs from them – this is a prelude to making body parts in a lab.”

Colm Gorey was a senior journalist with Silicon Republic

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