Acupuncture alleviates secondary brain injury in intracerebral hemorrhage-induced rats through activating the LKLF/Mfn2 pathway.

Intracerebral hemorrhage (ICH) is a hemorrhagic stroke causing severe secondary brain injury. Acupuncture has been shown to be effective in treating ICH, but the mechanism remains unclear. ICH was induced by injection of autologous blood, followed by acupuncture treatment at Baihui (DU20) and Qubin (GB7) acupoints. Histopathological results showed that acupuncture inhibited ICH-induced neuronal apoptosis and oxidative stress in perihematomal areas. Importantly, molecular and pathological findings proved that acupuncture stimulation significantly induced the Lung-Kruppel-like factor (LKLF) expression in perihematomal tissues of ICH-induced rats. The embryonic day 18 (E18) rat primary cortical neurons were treated with hemin as an in vitro model, and LKLF was overexpressed using lentiviral vectors to ascertain its function. LKLF overexpression inhibited neuronal apoptosis and oxidative stress and mitigated mitochondrial injury evidenced by decreased mitochondrial membrane potential in hemin-induced neurons. Both in vivo and in vitro experiments showed that mitofusin2 (Mfn2) expression was inhibited in neurons but increased upon acupuncture and LKLF overexpression. This suggested that the remission of ICH injury via acupuncture or LKLF overexpression might be related to the upregulation of Mfn2 reactivity. Dual luciferase assay demonstrated that LKLF activated Mfn2 promoter activity, showing that LKLF might improve mitochondrial function through transcriptional activation of Mfn2 expression, which subsequently mitigated hemin-induced neuronal injury. The rescue experiments in vivo indicated that LKLF knockdown suppressed Mfn2 expression and counteracted the attenuation of acupuncture on ICH-induced neuronal injury. These findings suggested that acupuncture might activate the LKLF/Mfn2 pathway, therefore inhibiting oxidative stress and neuronal apoptosis in ICH-induced rats.