Giving the Green Light After Stem Cell Repair

Could understanding how a certain protein, C1q, regulates neural stem-cell activity be the key to developing treatment options that give the central nervous system time to repair itself when needed?

What if our bodies had an internal traffic light, telling neural stem cells when to “stop” and when to “go”? New research suggests this is the role of paracrine complement protein C1q, which regulates neural stem-cell (NSC) activity.

“Acting through the Brain Angiogenesis Inhibitor 1 (BAI1) transmembrane receptor, not previously linked to NSC function, C1q acts like a traffic light, telling stem cells when to halt or increase activity,” says Aileen Anderson, a professor of physical medicine and rehabilitation in the UC Irvine School of Medicine and UC Irvine’s vice chancellor for research.

These findings, published in Nature Communications, demonstrate that blood plasma C1q concentrations associated with aging and blood-brain or spinal cord-barrier breakdown drives declines in NSC activity. The researchers reveal that the underlying mechanism is dependent on an interaction with BAI1, driving not only a halt in the cell cycle, which can allow for time for repair or growth in our central nervous system (CNS), but also metabolic changes associated with stem cell quiescence, which can prevent damaged cells from multiplying.

“Understanding C1q’s regulatory role in this way, particularly as it relates to central nervous system trauma, could lead to targeted methods for CNS repair and thus new treatment options for traumatic-brain or spinal-cord injuries,” says Katja M. Piltti, a project scientist in the UC Irvine Sue and Bill Gross Stem Cell Research Center who helped lead the study. “It could also play a role in preventing age-related neurodegenerative diseases, such as Alzheimer’s disease.”

Learn more in “C1q-BAI1 Signaling — A Neural Stem Cell Traffic Light,” a “behind the paper” blog in which Anderson and Piltti further outline the study’s findings and impact on future therapies.