SINGAPORE — When it comes to injuries, the young often heal better than the elderly. But research conducted by a Singaporean scientist has discovered a gene that restores the regenerative powers in adults.

Conducted at Harvard Medical School together with the Boston Children’s Hospital, the study authored by A*STAR scholar Ng Shyh-Chang found that a gene called Lin28a restored the regenerative abilities of cells in adult mice. The Lin28a gene is active in embryonic stem cells, but shut off in the cells of adults. Adult mice that had this gene re-activated were much better at regrowing hair and repairing cartilage, bone, skin and other soft tissue. Their cells were found to behave as if they were cells in a younger animal.

The results of the study will be published in top science journal Cell this week.

Dr Ng’s interest in Lin28 genes started when he was on an attachment at the Genome Institute of Singapore. The gene kept cropping up while he was working on cancer stem cells at Dr Lim Bing’s lab. “Two independent lines of inquiry of mine kept pointing towards Lin28, and I was getting quite inspired by its importance,” he said.

He joined the lab headed by Dr George Daley while pursuing his PhD at Harvard under A*STAR’s auspices. The lab had earlier published a paper on the role of Lin28b, a close relative of Lin28a, in cancer and stem cells.

Dr Ng started his work on Lin28a intending to explore its role in cancer, but instead discovered its role in regeneration. It was a surprise and a bonus, he said. “We noticed our transgenic mice didn’t develop tumours as we wished, but started healing their ear-tagging wounds faster than usual.” This led them to explore the regenerative powers of Lin28a.

The discovery is particularly important because this is the first time a gene has been found to reactivate embryo-like regenerative powers without causing cancer. Many of the genes involved in growth and repair, when over-expressed, can cause cancers. For example, Lin28b causes cancer without improving tissue regeneration much.

What surprised the researchers was that this gene stimulates tissue healing by boosting metabolism in mitochondria, the energy-producing parts of mammalian cells. “I was surprised that what scientists believed to be a mundane cellular ‘housekeeping’ function would be so important for tissue regeneration,” said Dr Ng.

But it makes sense in retrospect, he added. Researchers in the field of ageing already know that ageing in many tissues is caused when mitochondrial metabolism wears down. Dr Ng’s research does the converse: Reactivating the embryonic gene Lin28a made mitochondrial metabolism more efficient, just as it is in younger animals. This boost of energy in cells allows for faster healing and repair in tissues.

Is this discovery the key to halting ageing, then? Not quite, said Dr Ng. Right now, there is no way to deliver the protein coded by Lin28a into cells, which rules out using it as a drug treatment to promote healing. But because the scientists now understood how mitochondrial metabolism played a role in regeneration, they were able to improve wound healing in separate experiments by boosting mitochondrial metabolism with drugs. “This gives us hope that a metabolic approach can be translated into clinical applications in the short-term,” said Dr Ng.