Myocyte

New stem cell method produces millions of human brain and muscle cells in days

Scientists at the University of Cambridge and the Wellcome Trust Sanger Institute have created a new technique that simplifies the production of human brain and muscle cells – allowing millions of functional cells to be generated in just a few days.

Human pluripotent stem cells are ‘master cells’ that have the ability to develop into almost any type of tissue, including brain cells. They hold huge potential for studying human development and the impact of diseases, including cancer, Alzheimer’s, multiple sclerosis, and heart disease.

In a human, it takes nine to twelve months for a single brain cell to develop fully. It can take between three and 20 weeks using current methods to create human brain cells, including grey matter (neurons) and white matter (oligodendrocytes) from an induced pluripotent stem cell – that is, a stem cell generated by reprogramming a skin cell to its ‘master’ stage. However, these methods are complex and time-consuming, often producing a mixed population of cells.

Opti-OX

The new platform technology, OPTi-OX, optimises the way of switching on genes in human stem cells. Scientists applied OPTi-OX to the production of millions of nearly identical cells in a matter of days. In addition to the neurons, oligodendrocytes, and muscle cells the scientists created in the study, OPTi-OX holds the possibility of generating any cell type at unprecedented purities, in this short timeframe.

Producing neurons, oligodendrocytes and muscle cells

To produce the neurons, oligodendrocytes, and muscle cells, the team altered the DNA in…

Immune cells play surprising role in steady heartbeat

macrophages and heart cells
IT’S ELECTRIFYING Macrophages (green) “plug in” to heart cells (light purple and pink), providing an electrical boost that helps the heart cells contract and pump blood, a study in mice finds.

Immune system cells may help your heart keep the beat. These cells, called macrophages, usually protect the body from invading pathogens. But a new study published April 20 in Cell shows that in mice, the immune cells help electricity flow between muscle cells to keep the organ pumping.

Macrophages squeeze in between heart muscle cells, called cardiomyocytes. These muscle cells rhythmically contract in response to electrical signals, pumping blood through the heart. By “plugging in” to the cardiomyocytes, macrophages help the heart cells receive the signals and stay on beat.

Researchers have known for a couple of years that macrophages live in healthy heart tissue. But their specific functions “were still very much a mystery,” says Edward Thorp, an immunologist at Northwestern University’s Feinberg School of Medicine in Chicago. He calls the study’s conclusion that macrophages electrically couple with cardiomyocytes “paradigm shifting.” It highlights “the functional diversity and physiologic importance of macrophages, beyond their role in host defense,” Thorp says.

Matthias Nahrendorf, a cell biologist at Harvard Medical School, stumbled onto this electrifying find by accident.

Curious about how macrophages impact the heart, he tried to perform a cardiac MRI on a mouse genetically engineered to not have the immune cells. But the rodent’s heartbeat was too slow and irregular to…