Stem cells improve blood vessel function following spinal cord injury: Study

The study focused on suppressing damaging inflammation and improving blood vessel function, which may reduce the extent of injury

A new study published in STEM CELLS Translational Medicine (SCTM) by Badner et al shows how a minimally invasive stem cell treatment in rats can reduce secondary damage in traumatic spinal cord injury (SCI). While similar studies have also demonstrated the promise of stem cells as a therapy for SCI, what makes this one different is the type of stem cell used. For the first time, researchers evaluated whether a brain-derived stromal cell would be better suited to target the acute phase of SCI than cells derived from other tissue sources. The answer was yes.

SCI is a life-threatening condition with limited treatment options. It occurs in two phases. The primary phase takes place when the initial trauma causes mechanical injury to the spinal cord. The secondary injury comes in the hours after. As the body attempts to deal with what has happened, it releases a surge of chemicals causing inflammation, decreased spinal cord blood flow and cell death – which further exacerbates the injury. As the body cannot readily replace dying cells after spinal cord injury, neurological function becomes permanently impaired, resulting in severe movement and sensory disabilities.

While studies in animals have shown that the transplantation of stem cells might aid spinal cord repair by, among other things, replacing dead neural cells, the current study focused on suppressing damaging inflammation and improving blood vessel function, which may reduce the extent of injury.

Central nervous system (CNS) pericytes (specialised cells surrounding the capillaries) have recently gained significant attention within the scientific community. In addition to being recognized as major players in neural tissue trauma, pericytes share a common origin and, potentially, a common function with traditionally defined mesenchymal stromal/stem cells (MSCs). Although these cells have been previously studied in the lab, their therapeutic application (in vivo) has not been evaluated.

“Our study demonstrates that these cells not only display a MSC phenotype in a dish, but also have similar immunomodulatory effects in animals after spinal cord injury that are more potent than those of non-central nervous system tissue-derived cells. Therefore, these cells are of interest for therapeutic use in acute spinal cord injury,” said lead investigator Michael Fehlings.

The Fehlings research team, based at the Krembil Research Institute in Toronto Western Hospital and the University at Toronto, conducted their study by injecting human CNS-derived stromal cells into rats with SCI, and compared the results to a control group treated with MSCs. The cells protected blood vessels in the injured area, among other positive outcomes.

“These early effects further translated into enhanced functional recovery and tissue sparing 10 weeks after SCI.” Dr Fehlings added. “This work demonstrates a new therapeutic approach.”

“The ideal source of cells for treating spinal cord injury has been a controversial and open question,” said Anthony Atala, Editor-in-Chief of STEM CELLS Translational Medicine and Director of the Wake Forest Institute for Regenerative Medicine. “These results, showing the positive effects of central nervous system pericytes, not previously investigated for spinal cord injury, are intriguing and suggest a potential new therapeutic use,” he added.