Rolland William B, Krafft Paul R, Lekic Tim, Klebe Damon, LeGrand Julia, Weldon Abby Jones, Xu Liang, Zhang John H
Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, California, USA.
Department of Neurosurgery, Loma Linda University Medical Center, Loma Linda, California, USA.
J Neurochem. 2017 Mar;140(5):776-786. doi: 10.1111/jnc.13946. Epub 2017 Feb 2.
Fingolimod, a sphingosine-1-phosphate receptor (S1PR) agonist, is clinically available to treat multiple sclerosis and is showing promise in treating stroke. We investigated if fingolimod provides long-term protection from experimental neonatal germinal matrix hemorrhage (GMH), aiming to support a potential mechanism of acute fingolimod-induced protection. GMH was induced in P7 rats by infusion of collagenase (0.3 U) into the right ganglionic eminence. Animals killed at 4 weeks post-GMH received low- or high-dose fingolimod (0.25 or 1.0 mg/kg) or vehicle, and underwent neurocognitive testing before histopathological evaluation. Subsequently, a cohort of animals killed at 72 h post-GMH received 1.0 mg/kg fingolimod; the specific S1PR1 agonist, SEW2871; or fingolimod co-administered with the S1PR1/3/4 inhibitor, VPC23019, or the Rac1 inhibitor, EHT1864. All drugs were injected intraperitoneally 1, 24, and 48 h post-surgery. At 72 h post-GMH, brain water content, extravasated Evans blue dye, and hemoglobin were measured as well as the expression levels of phospho-Akt, Akt, GTP-Rac1, Total-Rac1, ZO1, occludin, and claudin-3 determined. Fingolimod significantly improved long-term neurocognitive performance and ameliorated brain tissue loss. At 72 h post-GMH, fingolimod reduced brain water content and Evans blue dye extravasation as well as reversed GMH-induced loss of tight junctional proteins. S1PR1 agonism showed similar protection, whereas S1PR or Rac1 inhibition abolished the protective effect of fingolimod. Fingolimod treatment improved functional and morphological outcomes after GMH, in part, by tempering acute post-hemorrhagic blood-brain barrier disruption via the activation of the S1PR1/Akt/Rac1 pathway.
芬戈莫德是一种鞘氨醇-1-磷酸受体(S1PR)激动剂,临床上可用于治疗多发性硬化症,并且在治疗中风方面显示出前景。我们研究了芬戈莫德是否能为实验性新生儿生发基质出血(GMH)提供长期保护,旨在支持芬戈莫德急性诱导保护的潜在机制。通过向右侧神经节隆起注入胶原酶(0.3 U)在P7大鼠中诱导GMH。GMH后4周处死的动物接受低剂量或高剂量芬戈莫德(0.25或1.0 mg/kg)或赋形剂,并在组织病理学评估前进行神经认知测试。随后,GMH后72小时处死的一组动物接受1.0 mg/kg芬戈莫德;特异性S1PR1激动剂SEW2871;或与S1PR1/3/4抑制剂VPC23019或Rac1抑制剂EHT1864共同给药的芬戈莫德。所有药物均在手术后1、24和48小时腹腔注射。在GMH后72小时,测量脑含水量、渗出的伊文思蓝染料和血红蛋白,并测定磷酸化Akt/Akt、GTP-Rac1/总Rac1、ZO1、闭合蛋白和紧密连接蛋白3的表达水平。芬戈莫德显著改善了长期神经认知表现并减轻了脑组织损失。在GMH后72小时,芬戈莫德降低了脑含水量和伊文思蓝染料渗出,并逆转了GMH诱导的紧密连接蛋白损失。S1PR1激动显示出类似的保护作用,而S1PR或Rac1抑制则消除了芬戈莫德的保护作用。芬戈莫德治疗改善了GMH后的功能和形态学结果,部分原因是通过激活S1PR1/Akt/Rac1途径减轻急性出血后血脑屏障破坏。