Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Fertility restoration after chemo—Maybe. A research paper presented at the American Society of Reproductive Medicine annual meeting in Baltimore this week got considerable attention on the web because it suggested women who had lost their fertility due to cancer chemotherapy could have it restored.

A team of Egyptian and US scientists, led by Sarah Mohamed of Mansoura Medical School in Egypt injected bone marrow mesenchymal stem cells directly into the ovaries of mice that had received chemotherapy. They saw restoration of function in the ovaries and the mice were also able to become pregnant and give birth to healthy pups.

While this is potentially exciting news, the stories tended to have headlines that were way too positive. This was a mouse study presented at a meeting, which has some peer review, but not nearly as rigorous as the review that happens before a journal publication. Much more research needs to verify this report before the thousands of women rendered infertile by their cancer therapy can consider baring children again.

The British paper The Telegraph, which had one of the most hyped headlines, also provided some good caveats for readers who stuck with the story to the end:

“Theoretically if you are regenerating the ovary you should be getting better quality eggs,” said Geoffrey Trew of Hammersmith Hospital in London. “Clearly we’re not there yet, and it’s good that the researchers are not over-claiming their findings, but it’s a great proof of concept.”

Potential way to end blood shortages. With the holiday season just a month away, another season is approaching for hospitals; a time of blood shortages as regular donors get too busy and distracted to roll up their sleeves. A team at Dana Farber Cancer Institute and Children’s Hospital, Boston, may have developed a way to eliminate those shortages. They used a gene editing technique to triple the number of red blood cells stem cells make. A major advance given the oxygen carrying capacity of red cells is the main reason for transfusions.

Previous studies had shown a certain gene, when active in the stem cells, resulted in lower numbers of red cells. So they used a genetic technique called RNA interference to turn that gene off. The resulting stem cells produced three times as many red cells as usual.

“We know that if we can make these cells, and improve upon the process, hopefully future blood shortages will not be a problem at all,” lead researcher Vijay Sankaran told Alice Park at Time.

 The team published their work in Cell Stem Cell and a press release from Dana Farber provides a bit more detail.

A mini-kidney (1mm diameter) grown from a patient’s stem cells.

Mini-kidneys mimic disease. Kidneys were once considered too complex for these early days of using stem cells to create organs. But creating mini-kidneys in the lab has turned out to be much easier than researcher thought. Stem cells, when given the right signals in the lab, self organize into organoids with the various components of kidneys as a few teams around the world have demonstrated over the past year.

But now, a team at Harvard and Brigham and Women’s Hospital has taken these mini organoids to a new level. They have used genetic engineering to model two debilitating kidney diseases in a dish. They used the popular gene editing technique CRISPR to give the stem cells the ability to create organoids that mimic polycystic kidney disease and glomerulonephritis.

“Mutation of a single gene results in changes in kidney structures associated with human disease, thereby allowing better understand of the disease and serving as models to develop therapeutic agents to treat these diseases,” explained senior author Joseph Bonventre of Brigham and Women’s.

The lead author on the study, Benjamin Freedman is now at the University of Washington, which put out a press release on the work picked up by MedicalXpress.

 Stem Cells can benefit from stress. The Huffington Post picked up a Q&A piece on stress that originally appeared in Berkeley Wellness. While detractors of the “Peoples’ Republic of Berkeley” might assume any article in that publication on stress would be long on psychology and short on hard science, they would be wrong.

The Q&A with University of California, Berkeley’s Daniela Kaufer features her work looking at the impact of stress on the stem cells in the brains of rats. It turns out short-term stress can actually enhance the proliferation of stem cells and in turn the number of new nerve cells they produce, which we wrote about based on her early results.

“The stress response is designed to help us react when something potentially threatening happens, to help us deal with it and learn from it. Our research shows that moderate, short-lived stress can improve alertness and performance and boost memory.”

However, she notes that chronic stress suppresses stem cell growth and the generation of new nerve cells. And being a Berkeley publication, the last question does get around to yoga for managing stress.