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.