中国神经再生研究(英文版) ›› 2022, Vol. 17 ›› Issue (7): 1566-1575.doi: 10.4103/1673-5374.330612

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

脑缺血延迟再灌注小鼠血管内皮生长因子上调伴随糖尿病致出血量增加

  

  • 出版日期:2022-07-15 发布日期:2022-01-18
  • 基金资助:
    香港特别行政区政府食物及卫生局健康及医疗研究基金(03142256)、香港研究资助局一般研究基金(GRF #HKU773613M)、香港大学基础研究种子基金计划(201811159123,201910159191)

Exacerbated VEGF up-regulation accompanies diabetes-aggravated hemorrhage in mice after experimental cerebral ischemia and delayed reperfusion

Angela Ka Wai Lai1, #, Tsz Chung Ng1, #, Victor Ka Lok Hung2, Ka Cheung Tam1, Chi Wai Cheung2, Sookja Kim Chung3, Amy Cheuk Yin Lo1, *   

  1. 1Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administration Region, China; 2Department of Anesthesiology, Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong Special Administration Region, China; 3Macau University of Science and Technology, Taipa, Macau Special Administration Region, China; School of Biomedical Sciences, The State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong Special Administration Region, China
  • Online:2022-07-15 Published:2022-01-18
  • Contact: Amy Cheuk Yin Lo, PhD, amylo@hku.hk.
  • Supported by:
    This study was supported by Health and Medical Research Fund, the Food and Health Bureau, The Government of the Hong Kong Special Administrative Region (03142256); General Research Fund, Hong Kong Research Grants Council (GRF #HKU773613M); Seed Funding Programme for Basic Research (201811159123, 201910159191), The University of Hong Kong (all to ACYL).

摘要:

再灌注治疗是缺血性脑卒中的首选治疗方法,但因其治疗时间窗短使其应用受到限制;尤其是对于糖尿病患者,其长时间缺血后的再灌注往往伴随着出血的加重,究其机制尚不清楚。实验通过对糖尿病Ins2Akita/+小鼠进行长时间的短暂大脑中动脉阻塞来模拟糖尿病患者接受延迟的机械血栓切除术来阐明这一机制。结果显示,与正常血糖的Ins2+/+小鼠相比,早在再灌注后2h,Ins2Akita/+小鼠就表现出神经功能障碍的快速进展,梗死和出血性转化增加,以及紧密连接蛋白ZO-1的下调和破坏血脑屏障的MMP-2和MMP-9的上调加剧。表明糖尿病导致再灌注后血管的完整性迅速受损,从而导致再灌注22h后死亡和出血性转化的进一步加剧。这一观察与再灌注后2h促血管生成的VEGF及其下游的p-Erk1/2更早、更强的上调有关,表明早期VEGF上调诱发的血管生成过早,导致糖尿病脑卒中的血管迅速崩解。ER应激相关的促凋亡性CHOP在Ins2Akita/+小鼠中过度表达,表明VEGF上调的加剧可能是由糖尿病条件下的ER应激引起的。总之,结果模拟了接受延迟机械血栓切除糖尿病患者的并发症,糖尿病引起的VEGF加速上调可能是加重出血性转化的基本因素。由此认为,抑制VEGF途径是一种潜在的方法,可使糖尿病脑卒中患者的再灌注治疗时间窗延长。

https://orcid.org/0000-0003-4239-6851 (Amy Cheuk Yin Lo)

Abstract: Reperfusion therapy is the preferred treatment for ischemic stroke, but is hindered by its short treatment window, especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by exacerbated hemorrhage. The mechanisms underlying exacerbated hemorrhage are not fully understood. This study aimed to identify this mechanism by inducing prolonged 2-hour transient intraluminal middle cerebral artery occlusion in diabetic Ins2Akita/+ mice to mimic patients with diabetes undergoing delayed mechanical thrombectomy. The results showed that at as early as 2 hours after reperfusion, Ins2Akita/+ mice exhibited rapid development of neurological deficits, increased infarct and hemorrhagic transformation, together with exacerbated down-regulation of tight-junction protein ZO-1 and up-regulation of blood-brain barrier-disrupting matrix metallopeptidase 2 and matrix metallopeptidase 9 when compared with normoglycemic Ins2+/+ mice. This indicated that diabetes led to the rapid compromise of vessel integrity immediately after reperfusion, and consequently earlier death and further aggravation of hemorrhagic transformation 22 hours after reperfusion. This observation was associated with earlier and stronger up-regulation of pro-angiogenic vascular endothelial growth factor (VEGF) and its downstream phospho-Erk1/2 at 2 hours after reperfusion, which was suggestive of premature angiogenesis induced by early VEGF up-regulation, resulting in rapid vessel disintegration in diabetic stroke. Endoplasmic reticulum stress-related pro-apoptotic C/EBP homologous protein was overexpressed in challenged Ins2Akita/+ mice, which suggests that the exacerbated VEGF up-regulation may be caused by overwhelming endoplasmic reticulum stress under diabetic conditions. In conclusion, the results mimicked complications in patients with diabetes undergoing delayed mechanical thrombectomy, and diabetes-induced accelerated VEGF up-regulation is likely to underlie exacerbated hemorrhagic transformation. Thus, suppression of the VEGF pathway could be a potential approach to allow reperfusion therapy in patients with diabetic stroke beyond the current treatment window. Experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong [CULATR 3834-15 (approval date January 5, 2016); 3977-16 (approval date April 13, 2016); and 4666-18 (approval date March 29, 2018)].

Key words: blood-brain barrier, brain injury, diabetes mellitus, hemorrhagic transformation, infarct, ischemia/reperfusion injury, middle cerebral artery occlusion, mouse model, stroke, vascular endothelial growth factor