ISS research suggests weightlessness accelerates aging in stem cells

According to a study that flew stem cells on four separate missions to ISS ranging in length from 32 to 45 days, weightlessness appears to age stem cells significantly.

Researchers from University of California San Diego Sanford Stem Cell Institute have discovered that spaceflight accelerates the aging of human hematopoietic stem and progenitor cells (HSPCs), which are vital for blood and immune system health. In a study published in Cell Stem Cell, the team used automated artificial intelligence (AI)-driven stem cell-tracking nanobioreactor systems in four SpaceX Commercial Resupply Services missions to the International Space Station (ISS) to track stem cell changes in real time. The findings show that the cells lost some of their ability to make healthy new cells, became more prone to DNA damage and showed signs of faster aging at the ends of their chromosomes after spaceflight — all signs of accelerated aging.

Upon return to Earth the study also found the cells recovered somewhat.

You can read the peer-reviewed paper here.

In a sense, this study confirms what numerous other research has found, that weightlessness mimics the conditions of old age, and causes the same physical decline seen in the elderly. It also shows that much of that damage in weightlessness is transient, recovering upon return to Earth.

This research once again highlights the imperative need to study the impact on various levels of artificial gravity on the human body. Will producing a 10% g environment — using centrifugal force — mitigate these negative impacts? Or will we have to simulate a full 1 g environment? Or something in between?

The first option is much easier in terms of engineering. The last will be complex and take time to develop.

At the moment almost no research has been done in this area. And it needs to happen soon, if people intend to go to Mars in the near future. Such journeys, six months minimum in weightlessness, are likely to leave the passengers somewhat debilitated upon arrival, no matter how much they exercise along the way. And being debilitated is not a good condition for a pioneer trying to build a new civilization on an alien world.

Injected stem cells cure osteoporosis in mice

Scientists have discovered that an injection of stem cells into mice with osteoporosis was able to completely cure them of the bone disease.

Researchers at the University of Toronto and The Ottawa Hospital had previously found a causal effect between mice developing age-related osteoporosis and a deficiency in mesenchymal stem cells (MSCs). One of the promising attributes of MSCs is that, while they can grow into different cells in the body just like other stem cells, they can be transplanted without the need for a match. “We reasoned that if defective MSCs are responsible for osteoporosis, transplantation of healthy MSCs should be able to prevent or treat osteoporosis,” says William Stanford, senior scientist at The Ottawa Hospital and Professor at the University of Ottawa.

To put this reasoning to the test, the scientists injected MSCs into mice with the condition. Six months later, which is one quarter of the life span of the animal, they observed a healthy functional bone in place of the damaged one. “We had hoped for a general increase in bone health,” says John E. Davies, co-author of the study. “But the huge surprise was to find that the exquisite inner ‘coral-like’ architecture of the bone structure of the injected animals – which is severely compromised in osteoporosis – was restored to normal.”

The importance of this discovery for space travel is that it might eventually allow scientists to use it to somehow prevent the loss of bone density during weightlessness.