Transplanting stem cells and activating the body´s own stem cells is considered by many to be a promising future treatment for a number of neurological diseases.

“At present, intensive research is being conducted all over the world to find ways of making stem cells develop into the right type of cell, move through the tissue of the brain to the right place, and then to survive. Although a great deal of work remains to be done before patients can benefit from this knowledge, our results are an important step in the right direction," says Milos Pekny, professor at Sahlgrenska Academy.

Astrocytes are a type of cell in the central nervous system that control many neurological functions, including the brain´s capacity to repair itself. The research group has previously shown that reduced activation of astrocytes means that injuries take longer to heal, but subsequently, the regeneration of the neurons´ fibres and synapses is better. The reduced activation of astrocytes also provides better results when transplanting cells to the retina.

“Astrocytes are also activated when we transplant stem cells into the brain, and we show that this impairs the development of the stem cells," says Milos Pekny.
 
The researchers have used gene-manipulated mice whose astrocytes cannot produce two proteins called GFAP and vimentin, which limits the astrocytes´ capacity to become activated. In cell cultures with astrocytes that do not produce these proteins, the generation of neurons increased by 65 percent. At the same time, the formation of new astrocytes increased by 124 percent.

In the study, stem cells where transplanted into the mice´s hippocampus, an area where new neurons are formed, even among adults. When mice with limited astrocyte activation were used as receptors, the number of neurons and astrocytes originating from the transplanted stem cells increased. The newly formed neurons were also more mature than in normal mice.

“These studies were conducted in collaboration with Professor Peter Eriksson, a friend, a fantastic colleague, and a pioneer in human neuro-stem-cell research, who left us suddenly just recently," says Milos Pekny.

Title: Increased Neurogenesis and Astrogenesis from Neural Progenitor Cells Grafted in the Hippocampus of GFAP-/-Vimentin-/- Mice
Publication: Stem Cells
Authors: Åsa Widestrand, Jonas Faijerson, Ulrika Wilhelmsson, Peter L. P. Smith, Lizhen Li, Carina Sihlbom, Peter S. Eriksson, Milos Pekny

Read abstract here