As part of the experiment Cerebral Aging [1]84 brain organoids were cultured [2] for 40 days in the International Space Station (ISS). Twelve organoids still alive [3] are then “ returned to Earth » last December. Cerebral organoids had already been in space, but none had yet been cultured there (see NASA sends stem cells into orbit to create organoids in weightlessness).
An experience and many challenges
“ Our hypothesis is that the conditions [rencontrées dans l’espace, micropesanteur et radiations cosmiques]accelerate aging », explains Frank Yates, teacher-researcher at SupBiotech. “ The ISS provides a unique environment to carry out this experiment: in orbit at an altitude of 400 km, it has been dedicated to carrying out scientific experiments in microgravity since 1998. »
Organoids measuring a few millimeters were first produced and grown on Earth. in cassettes specially designed and supplied by the American company Bioserve “. Afterwards, ” 384 organoids were placed in two hermetically sealed containers, guaranteeing a constant temperature of 37°C and a CO2 level of 5%. “. Conditions ” indispensable » to keep them alive. Both incubators were transferred to the Kennedy Space Center at Cape Canaveral, Florida. 84 organoids were selected for the flight, the others continued their development on the ground, serving as control samples.
Perspectives for better understanding degenerative pathologies?
From now on, scientists are analyzing all the samples repatriated to France since February 2024. The organoids are cut up, observed under a microscope and analyzed genetically. Their growing medium must also be examined. Indeed ” the molecules that were released by the organoids – called metabolites – tell us about their state of health », explains Miria Ricchetti, head of the Molecular Mechanisms of Pathological and Physiological Aging group at the Pasteur Institute. The first results should be available by the end of 2024.
“ If it turns out that aging is accelerated in space, the cultivation of brain organoids opens the way to exciting research for teams working on degenerative diseases like Alzheimer’s. », Estimates Frank Yates. ” En observing molecular and cellular changes in an aging organoid, scientists will better understand the development of degenerative pathologies “.
Editor’s note : The researchers do not specify whether they used embryonic stem or iPS cells. The use of human embryonic stem cells, taken from “supernumerary” embryos resulting from in vitro fertilization, leads to the destruction of the embryos from which they originate. In addition, the manufacturing of cerebral organoids raises ethical questions in itself (see Mini-brains grown in the laboratory: a problem of conscience?)
[1] Cerebral Aging is a cell biology experiment initiated in 2019 and developed by CADMOS at CNES, the Institut Pasteur, SupBiotech And BioServe Space Technologies. It aims to establish “ a model to study brain aging on a very small scale, that of the cell and even the molecule “.
[2] But ” several hundred » were made
[3] Others were “ fixed », refrigerated containers at 4°C or -80°C. “ This makes it possible to analyze their condition at the time of immobilization, and thus review their evolution over time.. »
Source: CNES (06/24/2024) – Photo: NASA Imagery from Pixabay
