Fig. 4

Dynamic changes of microglia polarisation following stroke. In the acute phase (within 24 h post-stroke), microglia exhibit an activation state dominated by the anti-inflammatory phenotype. At 6 h post-stroke, genes associated with the pro-inflammatory phenotype begin to be expressed; by 24 h, the expression levels of pro-inflammatory and anti-inflammatory phenotype-related genes reach a comparable magnitude. Upon entering the subacute phase (1 to 14/28 days post-stroke), microglial polarization shifts towards the pro-inflammatory phenotype. Within this phase, the trend of anti-inflammatory activation peaks at 3 to 5 days, after which the weighting of its associated gene expression begins to decline. By 14/28 days post-stroke, the expression of anti-inflammatory phenotype-related genes returns to baseline levels. In the chronic phase (beyond 14/28 days post-stroke), glial scar repair occurs, and the number of pro-inflammatory microglia gradually decreases