Geum japonicum Thunb. var. Chinese-P.decorata H.Andres herbal pair ameliorates CIRI-induced neuronal injury by facilitating mitochondrial transfer via the CD38/Miro1 signaling pathway.

BACKGROUND: Cerebral ischemia-reperfusion injury (CIRI) leads to severe mitochondrial dysfunction, which is a critical trigger of widespread neuronal apoptosis. Therefore, restoring mitochondrial homeostasis represents a key strategy for neuroprotection. Clinical observations suggest that the herbal pair Geum japonicum Thunb. var. chinense-P. decorata H. Andres (GJ-PD) shows therapeutic advantages in alleviating CIRI. However, its precise neuroprotective effects and underlying molecular mechanisms remain unclear. PURPOSE: This study aimed to elucidate the protective mechanisms of combined GJ-PD against CIRI, with particular emphasis on mitochondrial transfer and neuronal PANoptosis. METHODS: Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was used to identify the chemical constituents of GJ-PD in brain. The mechanisms of GJ-PD in CIRI were investigated using transmission electron microscopy, Western blotting, immunofluorescence, immunohistochemistry, and pathological staining. In addition, an in vitro oxygen-glucose deprivation/reoxygenation (OGD/R)-induced co-culture injury model was established using HT22 neurons and C8-D1A astrocytes. Scanning electron microscopy and laser confocal microscopy combined with MitoTracker staining were applied to explore the effects of GJ-PD on mitochondrial transfer and neuronal PANoptosis. Furthermore, the involvement of CD38 and Miro1 was examined using CD38- and Miro1-overexpression plasmids, both alone and in combination with GJ-PD treatment. RESULTS: GJ-PD exhibited significant neuroprotective effects following CIRI. It reduced cerebral infarct volume, alleviated neuronal oxidative stress and mitochondrial dysfunction, and increased CD38 and Miro1 expression, thereby attenuating programmed cell death. These effects contributed to its anti-CIRI efficacy. In vitro results were consistent with in vivo findings. Treatment with GJ-PD-containing plasma alone in the co-culture system enhanced mitochondrial transfer from C8-D1A astrocytes to neurons via tunneling nanotubes (TNTs). This was accompanied by increased neuronal proliferation and ATP production, along with reduced neuronal PANoptosis. Co-treatment with CD38- or Miro1-overexpressing C8-D1A cells further improved cell viability and ATP levels, decreased the expression of programmed cell death-related proteins, and elevated CD38 and Miro1 protein expression. Notably, Miro1 overexpression did not significantly affect CD38 expression. CONCLUSIONS: GJ-PD promotes the transfer of astrocytic mitochondria to neurons via TNTs through the CD38/Miro1 pathway. This process alleviates neuronal PANoptosis and improves neurological function, thereby exerting protective effects against CIRI.