A team of scientists in Cincinnati have grown 3D stomach tissue after bathing stem cells in a brew of growth-boosting chemicals.
Ulcers, stomach cancer, and other gastrointestinal diseases affect 10 percent of the world’s population, and their development is linked to chronic Helicobacter pylori infection. But because of the differences between people and lab animals such as mice and flies, existing live models aren’t ideal for studying human stomach development and disease.
To create a more realistic model, a team led by University of Cincinnati’s Yana Zavros and James Wells from Cincinnati Children’s Hospital Medical Center started with human stem cells — specifically pluripotent stem cells, which have the potential to become many different kinds of cells in the body. After that, the key was to identify the steps involved in normal stomach formation during our embryonic development.
By guiding the stem cells through all these natural, sequential processes in a petri dish, the team coaxed the hPSCs toward becoming stomach tissue. The researchers focused on a pathway of interactions that acts as a switch between growing tissues in the intestine and in the antrum (the stomach’s outlet to the small intestine). When the cells were three days old, they added proteins to suppress this pathway.
Over the course of a month, these steps resulted in the formation of so-called human gastric organoids. These miniature stomachs are around 3mm in diameter, and their 3D structure contains different kinds of cell types with functional characteristics resembling those seen in our stomachs.
Patients with macular degeneration are having their sight partially restored using human embryonic stem cells. This marks the first medium-term demonstration of the safety of embryonic stem cells, with implications for a host of other conditions.
Stem cell science is promising to replace everything from hearts to kidneys, with some hopes for diseases like MS as well. However, debate has raged over whether treatments should involve human embryonic stem cells (hESCs) or adult pluripotent stem cells from the patient themselves. The debate is partly about whether the use of hESCs is ethical, but there are also questions of safety.
Many attempts to use ESCs in animals have produced tumours, and rejection by the immune system can also be a problem. So the fact that 18 patients have had hESCs implanted without negative effects an average of 22 months later is big news.
Half the patients have Stargardt’s macular dystrophy and the other half have atrophic age-related macular degeneration, two of the most common causes of blindness in the developed world. Doses of 50,000-150,000 cells were applied. By treating one eye in each patient and leaving the other untouched, the researchers had the perfect control to establish the extent to which any changes were the result of the transplanted cells.
Ten of the patients experienced noticeable improvement in the visual acuity of their treated eye, while seven remained the same and only one got worse. On the other hand, none of the untreated eyes showed any improvement, although the researchers admit that one cannot rule out placebo effects since “both examiner and patient were aware of [which] eye underwent surgery.”
The U.S. has announced the allocation of $46 million to develop new technologies for exploring the brain.
Wearable brain scanners and lasers that can turn hundreds of cells on and off were among 58 projects awarded the figure in federal grants as part of President Obama’s $100 million initiative to unlock the secrets of the human brain.
Most of the projects focus on developing new tools to help answer basic questions about the brain, including classifying the myriad cell types in the brain and developing new methods to record brain activity and integrate that into fundamental theories of the brain.
Launched in 2013, the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative is designed to give scientists greater insight into how the healthy brain works and a better understanding of what systems go awry in diseases ranging from Alzheimer’s to schizophrenia.
“Every dollar we invested to map the human genome returned $140 to our economy — every dollar,” said Obama, referring to the decades-long Human Genome Project, a groundbreaking international effort to map our DNA, which this new project is being silhouetted against. “Today our scientists are mapping the human brain to unlock the answers to Alzheimer’s. They’re developing drugs to regenerate damaged organs, devising new materials to make batteries 10 times more powerful. Now is not the time to gut these job-creating investments in science and innovation.”