Rhodiosin promotes cerebral angiogenesis in mice with ischemic stroke via PI3K/Akt pathway activation

BACKGROUND: Ischemic stroke remains a lethal disease with high morbidity and disability, yet effective therapeutic options for chronic recovery are still limited. Angiogenesis facilitates post-stroke blood supply restoration by reconstructing vascular networks, which helps rescue the penumbra and recover neurological function. Rhodiosin is a bioactive compound derived from rhodiola crenulata, exhibiting multiple pharmacological activities. However, whether rhodiosin exerts protective effects by promoting angiogenesis after stroke, as well as the underlying mechanisms, remains unclear. PURPOSE: This study aimed to investigate whether rhodiosin promotes cerebral angiogenesis and neurological functional recovery after stroke, and to explore the underlying mechanisms. STUDY DESIGN AND METHODS: Stroke was induced in mice by distal middle cerebral artery occlusion (dMCAO). Rhodiosin was administered intraperitoneally daily post-surgery. Therapeutic efficacy was assessed based on neurological deficits and infarct volume. Microvascular density and pericyte/astrocyte coverage were evaluated using immunofluorescence staining. Cerebral blood flow (CBF) was monitored by laser speckle imaging. Two-photon microscopy was employed to measure dynamic changes in cerebrovascular diameter and density. RNA sequencing was performed to identify rhodiosin-associated pathways. PI3K/Akt pathway factors were examined by Western blot and qRT-PCR. The human cerebral microvascular endothelial cells (hCMEC/D3) were utilized to explore the underlying mechanisms in vitro. RESULTS: Rhodiosin enhanced neurological recovery and reduced infarct volume post-stroke. It improved CBF and increased vascular diameter and density in the penumbra. It also promoted angiogenesis by increasing BrdU⁺/CD31⁺ cells and enhancing pericyte/astrocyte coverage around microvessels. Moreover, rhodiosin facilitated endothelial cell migration and tube formation under OGD conditions. Rhodiosin upregulated PI3K/Akt phosphorylation and the expression of their downstream targets (HIF-1α, Ang1, VEGF). These effects were partially or fully reversed by PI3K/Akt inhibition (LY294002/MK-2206 in vivo, shRNA transfection in vitro). Integrating RNA-seq with experimental validation, we confirmed that activation of PI3K/Akt mediates rhodiosin's pro-angiogenic effect. CONCLUSION: Rhodiosin promotes neurological recovery post-stroke by enhancing cerebral angiogenesis via PI3K/Akt pathway activation, highlighting its potential as a therapeutic candidate for ischemic stroke during the subacute/chronic recovery phase.