Angiogenic Mechanisms in Ischemic Stroke

Ischemic stroke triggers a cascade of vascular, glial and inflammatory responses that reshape the neurovascular unit and influence recovery. Interruption of cerebral blood flow leads to hypoxia, excitotoxicity and blood–brain barrier (BBB) disruption in the core and penumbra. Surviving endothelial cells respond to hypoxia by upregulating pro-angiogenic factors such as vascular endothelial growth factor (VEGF), fibroblast growth factors and matrix metalloproteinases, which remodel extracellular matrix and allow endothelial proliferation, migration and tube formation. Non-endothelial components—including reactive astrocytes, pericytes, microglia and infiltrating immune cells—secrete cytokines and chemokines (for example CXCL12) that coordinate vessel sprouting and stabilisation. Astrocyte-derived signals support basement-membrane reconstruction and perivascular scaffolding, while microglial polarisation shifts from neurotoxic (M1) to reparative (M2) phenotypes, releasing TGF-β and MMP-9 that further promote new vessel formation. Endothelial progenitor cells mobilised from bone marrow contribute to neovessel integration. This tightly regulated angiogenic response not only restores perfusion but also creates a permissive microenvironment for neurogenesis and synaptic rewiring. Dysregulation of these mechanisms, however, may exacerbate oedema, haemorrhagic transformation or chronic inflammation, underscoring the importance of temporal control in therapeutic strategies.

Research from Nature Portfolio

Recent work has demonstrated that microglia preconditioned by oxygen–glucose deprivation adopt an M2-like reparative phenotype capable of secreting key remodelling factors. In a rat model of focal cerebral ischemia, intravascular delivery of optimally preconditioned microglia between 7 and 14 days post-stroke enhanced angiogenesis in the peri-infarct cortex and improved neurological scores by 28 days. M2 microglia released abundant vascular endothelial growth factor, transforming growth factor-β and matrix metalloproteinase-9, driving endothelial proliferation and vessel maturation without exacerbating acute injury. This study offers a cell-based paradigm for harnessing endogenous immune cells to orchestrate angiogenic repair in the subacute phase.

Angiogenic Mechanisms in Ischemic Stroke publication trend

The graph below shows the total number of articles in angiogenic mechanisms in ischemic stroke across all publications each year (not limited to Nature Index journals).

Technical terms

Angiogenesis: the process by which new blood vessels form from pre-existing vasculature, critical for restoring perfusion after ischaemia.

Blood–brain barrier (BBB): a selective endothelial interface that regulates passage of molecules and cells between circulation and neural tissue.

Reactive astrocytes: astrocytes that undergo phenotypic changes in response to injury, releasing factors that influence vascular and neural repair.

M2 microglia: a reparative activation state of microglial cells characterised by anti-inflammatory cytokines and support for tissue remodelling.

Vascular endothelial growth factor (VEGF): a family of signalling proteins that stimulate endothelial cell proliferation, migration and new vessel formation.

CXCL12/CXCR4 signalling: a chemokine axis involved in cell recruitment, survival and angiogenic guidance during tissue repair.

References

1. CD13 facilitates immune cell migration and aggravates acute injury but promotes chronic post-stroke recovery. Journal of Neuroinflammation (2023).
2. Reactive astrocytes facilitate vascular repair and remodeling after stroke. Cell Reports (2021).
3. Factors Secreted by Endothelial Progenitor Cells Enhance Neurorepair Responses after Cerebral Ischemia in Mice. PLOS ONE (2013).
4. Microglia preconditioned by oxygen-glucose deprivation promote functional recovery in ischemic rats. Scientific Reports (2017).
5. Inflammation-Mediated Angiogenesis in Ischemic Stroke. Frontiers in Cellular Neuroscience (2021).