Scientists discovered that star-shaped brain cells hidden far from injury sites orchestrate spinal cord healing through a previously unknown protein signaling network.
Story Snapshot
- Lesion-remote astrocytes—support cells distant from spinal cord injuries—release CCN1 protein to activate debris-clearing immune cells, reducing inflammation and driving repair
- The discovery validates in both mouse models and human tissues from spinal cord injury and multiple sclerosis patients, shifting therapeutic focus from injury sites to remote cellular communication
- Multiple parallel breakthroughs in 2025 reveal overlooked support cells—astrocytes, microglia, fibroblasts—as master orchestrators of central nervous system healing
- Researchers at Cedars-Sinai, UCSF, and UCSD are advancing toward human trials using repurposed drugs and cell transplants targeting these newly understood mechanisms
The Cells Science Overlooked for Forty Years
Spinal cord injuries trap 270,000 Americans in permanent disability because damaged neurons in the central nervous system refuse to regrow. For decades, researchers fixated on coaxing neurons back to life or implanting stem cells directly at injury sites. That strategy delivered modest gains but never cracked the fundamental problem: scar tissue and chronic inflammation block regeneration. The breakthrough came when Cedars-Sinai researchers stopped looking at the injury itself and examined what happened in brain tissue inches away. They found lesion-remote astrocytes, star-shaped support cells that activate after injury despite sitting far from the damage zone.
A Hidden Repair System Operating Behind the Scenes
Joshua Burda’s lab at Cedars-Sinai documented how these remote astrocytes manufacture CCN1 protein, which broadcasts repair signals to microglia—the brain’s immune cells. Microglia respond by clearing cellular debris and tamping down inflammation, creating conditions where neurons can potentially reconnect. The team confirmed this mechanism in mouse spinal cord injury models and then validated it in human tissue samples from patients with spinal cord injuries and multiple sclerosis. David Underhill, the department chair, emphasized that targeting lesion-remote astrocytes offers a realistic path to limit inflammation and enhance regeneration across multiple central nervous system diseases.
Parallel Discoveries Rewrite the Support Cell Playbook
The Cedars-Sinai findings arrived alongside complementary revelations from other institutions. UCSF researchers identified brain fibroblasts—cells previously dismissed as mere structural scaffolding—that balance scar formation with healing after traumatic brain injuries, the leading cause of disability in the United States. Ari Molofsky noted these cells possess surprising sophistication in solving the healing-versus-inflammation trade-off. Meanwhile, Boston Children’s Hospital demonstrated that transplanting microglia into adult mice produces scar-free spinal cord healing, with microglia acting as primary organizers of the repair process. These studies collectively expose a network of support cells whose injury-response capabilities scientists underestimated or ignored entirely.
From Laboratory Bench to Patient Bedside
UCSD accelerated the translation timeline by using bioinformatics to screen existing drugs against adult human brain cells cultured in the lab, a technical feat that eluded researchers until recently. The team identified Thiorphan, a compound previously tested in humans, that boosts neurite outgrowth in both cultured human neurons and rat models, achieving 50 to 100 percent hand function recovery in injured rats. Mark Tuszynski plans to combine Thiorphan with stem cell therapies in upcoming clinical trials, bypassing years of safety testing because the drug already cleared human safety hurdles. Karolinska Institutet researchers mapped genetic enhancers that flip support cells into repair mode after spinal cord injuries, providing additional drug targets.
Economic and Medical Stakes Justify the Urgency
Spinal cord and brain injuries cost the United States over 40 billion dollars annually in medical care and lost productivity. Effective regenerative therapies would slash those costs while restoring independence to patients who currently face lifelong paralysis or cognitive impairment. The science extends beyond traumatic injuries to encompass stroke, multiple sclerosis, Alzheimer’s disease, and ALS, conditions where support cell dysfunction contributes to neurodegeneration. Burda’s assertion that astrocytes function as critical responders but remain understudied rings true when you consider that neuron-centric research dominated funding for four decades while support cells received scraps. The convergence of genomics, single-cell sequencing, and artificial intelligence finally gave researchers tools to observe these cells in action.
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Sources:
Bioinformatics Uncovers Regenerative Therapy for Spinal Cord Injury
These Cells Have Hidden Powers That Could Heal Brain Injuries
How the Nervous System Activates Repair After Spinal Cord Injury
