Dl-3-N-Butylphthalide Promotes Angiogenesis in an Optimized Model of Transient Ischemic Attack in C57BL/6 Mice

Abstract

Transient ischemic attack (TIA) has been widely regarded as a clinical entity. Even though magnetic resonance imaging (MRI) results of TIA patients are negative, potential neurovascular damage might be present, and may account for long-term cognitive impairment. Animal models that simulate human diseases are essential tools for in-depth study of TIA. Previous studies have clarified that Dl-3-N-butylphthalide (NBP) promotes angiogenesis after stroke. However, the effects of NBP on TIA remain unknown. This study aims to develop an optimized TIA model in C57BL/6 mice to explore the microscopic evidence of ischemic injury after TIA, and investigate the therapeutic effects of NBP on TIA. C57BL/6 mice underwent varying durations (7, 8, 9 or 10 min) of middle cerebral artery occlusion (MCAO). Cerebral artery occlusion and reperfusion were assessed by laser speckle contrast imaging. TIA and ischemic stroke were distinguished by neurological testing and MRI examination at 24 h post-operation. Neuronal apoptosis was examined by TUNEL staining. Images of submicron cerebrovascular networks were obtained via micro-optical sectioning tomography. Subsequently, the mice were randomly assigned to a sham-operated group, a vehicle-treated TIA group or an NBP-treated TIA group. Vascular density was determined by immunofluorescent staining and fluorescein isothiocyanate method, and the expression of angiogenic growth factors were detected by western blot analysis. We found that an 8-min or shorter period of ischemia induced neither permanent neurological deficits nor MRI detectable brain lesions in C57BL/6 mice, but histologically caused neuronal apoptosis and cerebral vasculature abnormalities. NBP treatment increased the number of CD31+ microvessels and perfused microvessels after TIA. NBP also up-regulated the expression of VEGF, Ang-1 and Ang-2 and improved the cerebrovascular network. In conclusion, 8 min or shorter cerebral ischemia induced by the suture MCAO method is an appropriate TIA model in C57BL/6 mice, which conforms to the definition of human TIA, but causes microscopic neurovascular impairment. NBP treatment increased the expression of angiogenic growth factors, promoted angiogenesis and improved cerebral microvessels after TIA. Our study provides new insights on the pathogenesis and potential treatments of TIA.

Non-invasive Vagus Nerve Stimulation in Cerebral Stroke: Current Status and Future Perspectives

“…After focal cerebral ischemia, the newly formed collateral blood vessels can improve perfusion of the surrounding tissues and promote recovery of nervous system functions. Recent studies have suggested that angiogenesis, almost in parallel to neurogenesis, participates in the recovery of neurological function after ischemic stroke ( Song et al, 2019 ; Alrafiah et al, 2021 ; Wang et al, 2021a ). It was proposed that VNS increased hippocampal progenitor cell proliferation in the adult rat dentate gyrus, so that such progenitor cells contribute to the healing of damaged neurons from ischemic injury ( Lu et al, 2017 ).…”

Electroacupuncture and human iPSC-derived small extracellular vesicles regulate the gut microbiota in ischemic stroke via the brain-gut axis

“…MCAO in mice was established using a laser speckle contrast imager (PeriCam PSI HR System, Jarfalla-Stockholm, Sweden) while supervising regional cerebral blood flow (rCBF). Animals were excluded that died or failed to show a ≤50% or ≥80% rCBF reduction for further analysis (39)(40)(41). Sham group mice underwent the same procedure but without MCAO.…”

Effect of Dl-3-n-butylphthalide on mitochondrial Cox7c in models of cerebral ischemia/reperfusion injury

“…The probe was synthesized and provided by WuXi AppTec Co., Ltd. (Wuxi, China). As previously reported, NBP was dissolved in corn oil and administered to MCAO mice at a dose of 60 mg/kg/day via oral gavage immediately after reperfusion, and mice were subjected to continuous administration for 3 days (Wang et al, 2021;Yang et al, 2019). Mice that received an equal volume of corn oil orally served as controls.…”

“…Although thrombolytic therapy using recombinant tissue plasminogen activator (rt-PA) is the preferred treatment for acute ischemic stroke, strict time windows and exclusion criteria allow only 3-5% of patients to benefit (Adeoye et al, 2011). In addition, rt-PA treatment is associated with certain side effects, for example, it amplifies the neurotoxicity induced by hemoglobin and causes damage to neuronal cells (Wang et al, 2021). Furthermore, cerebral ischemia/reperfusion causes a series of biochemical cascades, which further worsens damage to brain tissue (i.e., ischemia/reperfusion injury) and weakens the beneficial effects of vascular recanalisation (Yang and Betz 1994;Aronowski et al, 1997).…”