Aug. 12 (UPI) — Researchers at the University of California San Diego have developed a way to keep lab-grown stem cells healthy for longer periods of time, they said in an article published Thursday by Cell Stem Cell.
Their discovery could increase stem cell availability, which is welcome news for patients on transplant waiting lists, and may provide clues toward methods for slowing human aging, according to the researchers.
“Now, we can preserve high-quality stem cells in culture over a prolonged period of time,” study co-author Robert Signer said in a press release.
“We hope the increased quality will lead to improved clinical outcomes,” said Signer, an assistant professor of medicine at the University of California, San Diego.
Hematopoietic, or immature, stem cells, which are harvested from blood and bone marrow, serve an important role in medical research, though it is difficult to grow them in a lab setting, according to EuroStemCell, a European research and advocacy organization for stem cell research.
This is because it remains unclear what nutrients these stem cells need to grow and thrive, EuroStemCell says.
These stem cells are also infused intravenously to reestablish red blood cell production in patients whose bone marrow or immune system is damaged by diseases such as leukemia, lymphoma, anemia and immune deficiency disorders, to says.
However, donor stem cells are not always available for patients who need them, hence the need to more efficiently grow them in the lab, Signer and his colleagues said.
Although other researchers have tried to culture hematopoietic stem cells by recreating the bone marrow environment in a dish, the resulting cells typically fail to remain healthy, for a sufficient amount of time, to be used in transplant procedures, they said.
To address this issue, this study explored the internal mechanism that makes the cells unhealthy to begin and sought to find ways to reverse these processes, according to the researchers.
In their experiments, they found that in the foreign environment of the culture dish, stem cells begin producing excess proteins, causing extreme stress, they said.
This stress activates the heat-shock response, which is designed to reduce this stress using the gene heat shock factor 1, the researchers said.
They identified two small molecules that super-activate heat shock factor 1 and, by adding these to mouse and human hematopoietic stem cell cultures, they found that they enhanced activity of the heat shock pathway and helped “rebalance” the cells’ state of equilibrium or homeostasis, they said.
The heat shock pathway also keeps stem cells healthy in their native bone marrow during aging, meaning it is inactive in the stem cells of young adults but is turned on in middle-aged and older adults, Signer said.
The next step is to test how these small molecules affect the health of human stem cells in transplantation systems, he said.
In addition, “super-activating” heat shock factor 1 might eventually be used to improve stem cell and tissue function in aging to prevent blood disorders and boost immunity in older adults, according to Signer.
“Even for patients who do receive stem cell therapies, transplanting more cells yields fewer complications and increases chances of overarching success,” Signer said.
“Protein damage impairs stem cells during aging and likely contributes to disrupting blood and immune cell production in older people [but] heat shock factor 1 is activated during aging to keep your stem cells fit,” he said.