Scientists Uncover Why Brain Damage Continues After Stroke

Every changeable originates pinch a abrupt interruption of humor travel successful nan brain. But what happens afterward—why neurons proceed to suffer usability and dice complete nan pursuing days—has remained 1 of nan astir important unanswered questions successful neuroscience.

A investigation squad led by Director C. Justin LEE astatine nan Center for Memory and Glioscience wrong nan Institute for Basic Science (IBS), successful collaboration pinch Professor RYU Seungjun of Eulji University, has now uncovered a antecedently chartless system that drives this delayed encephalon damage. Their findings show that changeable is not only caused by nan first nonaccomplishment of humor flow, but besides by a concatenation guidance wrong nan encephalon that unfolds complete time.

In nan brain, neurons trust connected astrocytes—star-shaped support cells that thief support nan chemic situation and protect neural circuits. After a stroke, astrocytes quickly respond to wounded by forming a building known arsenic nan glial barrier, which has agelong been thought to protect surrounding tissue. However, nan caller study shows that this consequence tin return a harmful turn.

The researchers recovered that instantly aft a stroke, levels of hydrogen peroxide (H₂O₂), a reactive oxygen molecule, emergence sharply successful nan affected region. This surge triggers astrocytes to acquisition a metabolic displacement and statesman producing ample amounts of type I collagen, a structural macromolecule seldom recovered successful nan patient brain. As collagen accumulates, it becomes incorporated into nan glial barrier, creating a dense situation that actively promotes neuronal decease alternatively than preventing it.

To corroborate that collagen plays a nonstop domiciled successful this process, nan squad first blocked its accumulation by silencing a cardinal cistron successful astrocytes. When collagen synthesis was suppressed, neuronal decease was importantly reduced, demonstrating that this pathway is not simply associated pinch harm but is simply a awesome driver of it. Further experiments showed that collagen tin enactment arsenic a signaling molecule, activating receptors connected neurons and triggering a slow degenerative process that unfolds complete respective days.

We elucidated, astatine nan molecular and cellular levels, nan system by which reactive oxygen type induce collagen synthesis successful astrocytes. This uncovering provides a important hint for knowing nan divers causes of neuronal decease and whitethorn service arsenic a instauration for processing treatments not only for stroke, but besides for neurodegenerative diseases specified arsenic dementia and Parkinson's disease."

Dr. Boyoung Lee, Study Co-Corresponding Author and Research Fellow/ Principal Investigator, Institute for Basic Science

The researchers past asked whether this damaging cascade could beryllium stopped astatine an earlier stage. Instead of targeting collagen directly, they tested a recently developed supplier called KDS12025, which reduces hydrogen peroxide levels and prevents nan full process from being triggered. In rodent models of stroke, nan curen reduced collagen accumulation, prevented nan statement of nan glial barrier, preserved neuronal function, and restored centrifugal performance.

Most strikingly, nan supplier remained effective moreover erstwhile administered up to 2 days aft changeable onset. This uncovering is peculiarly important because existent changeable treatments are typically constricted to a constrictive "golden time" model of only a fewer hours. Extending this model from hours to days suggests that encephalon harm antecedently thought to beryllium irreversible whitethorn still beryllium preventable.

To analyse whether these effects could construe to much human-like systems, nan squad applied nan aforesaid attack to a changeable exemplary successful monkeys. Untreated animals were incapable to grasp nutrient owed to paralysis, while monkeys treated pinch KDS12025 regained centrifugal usability and successfully grasped nutrient successful each 10 retired of 10 attempts during behavioral testing. The treated animals besides showed reduced encephalon harm and improved wide neurological function.

Co-corresponding writer Professor RYU Seungjun added, "We propose hydrogen peroxide and collagen arsenic caller therapeutic targets for stroke. By demonstrating efficacy successful a non-human primate exemplary alternatively than only successful cells aliases mini animals, we expect a important simplification successful nan clip required for objective translator and caller dream for patients."

These findings propose that changeable is not simply a one-time event, but a progressive biologic process driven by interactions betwixt different compartment types successful nan brain. By identifying hydrogen peroxide-induced collagen accumulation successful astrocytes arsenic a cardinal measurement successful this process, nan study provides a caller model for knowing really encephalon harm develops—and really it mightiness beryllium stopped.

Beyond stroke, nan system uncovered successful this activity whitethorn besides person broader implications for neurological disorders involving oxidative accent and insubstantial remodeling, including neurodegenerative diseases. The results constituent toward a caller therapeutic strategy: intervening not only astatine nan infinitesimal of stroke, but during nan captious play afterward erstwhile encephalon cells are still astatine consequence but perchance recoverable.

Corresponding writer Director C. Justin LEE (IBS) remarked, "By establishing a 'one-stop investigation system' that integrates nan full process—from basal investigation to supplier improvement and preclinical validation—we person succeeded not only successful identifying nan guidelines origin of changeable but besides successful presenting a actual therapeutic strategy. We will proceed to prosecute basal subject investigation that straight benefits humanity and society, arsenic exemplified by KDS12025."