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Abstract：
BACKGROUND: Intracerebral hemorrhage (ICH) is a devastating neurological disease causing severe sensorimotor dysfunction and cognitive decline, yet there is no effective treatment strategy to alleviate outcomes of these patients. The Mas axis-mediated neuroprotection is involved in the pathology of various neurological diseases, however, the role of the Mas receptor in the setting of ICH remains to be elucidated.
METHODS: C57BL/6 mice were used to establish the ICH model by injection of collagenase into mice striatum. The Mas receptor agonist AVE0991 was administered intranasally (0.9 mg/kg) after ICH. Using a combination of behavioral tests, Western blots, immunofluorescence staining, hematoma volume, brain edema, quantitative-PCR, TUNEL staining, Fluoro-Jade C staining, Nissl staining, and pharmacological methods, we examined the impact of intranasal application of AVE0991 on hematoma absorption and neurological outcomes following ICH and investigated the underlying mechanism.
RESULTS: Mas receptor was found to be significantly expressed in activated microglia/macrophages, and the peak expression of Mas receptor in microglia/macrophages was observed at approximately 3-5 days, followed by a subsequent decline. Activation of Mas by AVE0991 post-treatment promoted hematoma absorption, reduced brain edema, and improved both short- and long-term neurological functions in ICH mice. Moreover, AVE0991 treatment effectively attenuated neuronal apoptosis, inhibited neutrophil infiltration, and reduced the release of inflammatory cytokines in perihematomal areas after ICH. Mechanistically, AVE0991 post-treatment significantly promoted the transformation of microglia/macrophages towards an anti-inflammatory, phagocytic, and reparative phenotype, and this functional phenotypic transition of microglia/macrophages by Mas activation was abolished by both Mas inhibitor A779 and Nrf2 inhibitor ML385. Furthermore, hematoma clearance and neuroprotective effects of AVE0991 treatment were reversed after microglia depletion in ICH.
CONCLUSIONS: Mas activation can promote hematoma absorption, ameliorate neurological deficits, alleviate neuron apoptosis, reduced neuroinflammation, and regulate the function and phenotype of microglia/macrophages via Akt/Nrf2 signaling pathway after ICH. Thus, intranasal application of Mas agonist ACE0991 may provide promising strategy for clinical treatment of ICH patients.
METHODS: C57BL/6 mice were used to establish the ICH model by injection of collagenase into mice striatum. The Mas receptor agonist AVE0991 was administered intranasally (0.9 mg/kg) after ICH. Using a combination of behavioral tests, Western blots, immunofluorescence staining, hematoma volume, brain edema, quantitative-PCR, TUNEL staining, Fluoro-Jade C staining, Nissl staining, and pharmacological methods, we examined the impact of intranasal application of AVE0991 on hematoma absorption and neurological outcomes following ICH and investigated the underlying mechanism.
RESULTS: Mas receptor was found to be significantly expressed in activated microglia/macrophages, and the peak expression of Mas receptor in microglia/macrophages was observed at approximately 3-5 days, followed by a subsequent decline. Activation of Mas by AVE0991 post-treatment promoted hematoma absorption, reduced brain edema, and improved both short- and long-term neurological functions in ICH mice. Moreover, AVE0991 treatment effectively attenuated neuronal apoptosis, inhibited neutrophil infiltration, and reduced the release of inflammatory cytokines in perihematomal areas after ICH. Mechanistically, AVE0991 post-treatment significantly promoted the transformation of microglia/macrophages towards an anti-inflammatory, phagocytic, and reparative phenotype, and this functional phenotypic transition of microglia/macrophages by Mas activation was abolished by both Mas inhibitor A779 and Nrf2 inhibitor ML385. Furthermore, hematoma clearance and neuroprotective effects of AVE0991 treatment were reversed after microglia depletion in ICH.
CONCLUSIONS: Mas activation can promote hematoma absorption, ameliorate neurological deficits, alleviate neuron apoptosis, reduced neuroinflammation, and regulate the function and phenotype of microglia/macrophages via Akt/Nrf2 signaling pathway after ICH. Thus, intranasal application of Mas agonist ACE0991 may provide promising strategy for clinical treatment of ICH patients.
摘要：
背景：脑出血（ICH）是一种破坏性的神经系统疾病，可导致严重的感觉运动功能障碍和认知功能下降，然而,目前尚无有效的治疗策略来缓解这些患者的预后.Mas轴介导的神经保护与各种神经系统疾病的病理有关，然而,Mas受体在ICH中的作用仍有待阐明.
方法：C57BL/6小鼠纹状体注射胶原酶建立ICH模型。在ICH后鼻内施用Mas受体激动剂AVE0991(0.9mg/kg)。使用行为测试的组合，西方印迹,免疫荧光染色，血肿体积,脑水肿,定量PCR，TUNEL染色,Fluoro-JadeC染色,尼氏染色,和药理学方法，我们研究了鼻内应用AVE0991对ICH后血肿吸收和神经系统结局的影响,并研究了其潜在机制.
结果：发现Mas受体在活化的小胶质细胞/巨噬细胞中显著表达，Mas受体在小胶质细胞/巨噬细胞中的峰值表达在大约3-5天观察到，随后下降。治疗后AVE0991激活Mas可促进血肿吸收，减少脑水肿，并改善ICH小鼠的短期和长期神经功能。此外，AVE0991治疗可有效减弱神经元凋亡，抑制中性粒细胞浸润，并减少ICH后血肿周围炎症细胞因子的释放。机械上,AVE0991后处理显着促进小胶质细胞/巨噬细胞向抗炎，吞噬,和修复表型，Mas抑制剂A779和Nrf2抑制剂ML385消除了通过Mas激活的小胶质细胞/巨噬细胞的这种功能表型转变。此外，ICH小胶质细胞清除后，AVE0991治疗的血肿清除和神经保护作用被逆转。
结论：Mas激活可促进血肿吸收，改善神经功能缺损，缓解神经元凋亡，减少神经炎症，并通过Akt/Nrf2信号通路调节ICH后小胶质细胞/巨噬细胞的功能和表型。因此，鼻内应用Mas激动剂ACE0991可能为ICH患者的临床治疗提供有希望的策略。
方法：C57BL/6小鼠纹状体注射胶原酶建立ICH模型。在ICH后鼻内施用Mas受体激动剂AVE0991(0.9mg/kg)。使用行为测试的组合，西方印迹,免疫荧光染色，血肿体积,脑水肿,定量PCR，TUNEL染色,Fluoro-JadeC染色,尼氏染色,和药理学方法，我们研究了鼻内应用AVE0991对ICH后血肿吸收和神经系统结局的影响,并研究了其潜在机制.
结果：发现Mas受体在活化的小胶质细胞/巨噬细胞中显著表达，Mas受体在小胶质细胞/巨噬细胞中的峰值表达在大约3-5天观察到，随后下降。治疗后AVE0991激活Mas可促进血肿吸收，减少脑水肿，并改善ICH小鼠的短期和长期神经功能。此外，AVE0991治疗可有效减弱神经元凋亡，抑制中性粒细胞浸润，并减少ICH后血肿周围炎症细胞因子的释放。机械上,AVE0991后处理显着促进小胶质细胞/巨噬细胞向抗炎，吞噬,和修复表型，Mas抑制剂A779和Nrf2抑制剂ML385消除了通过Mas激活的小胶质细胞/巨噬细胞的这种功能表型转变。此外，ICH小胶质细胞清除后，AVE0991治疗的血肿清除和神经保护作用被逆转。
结论：Mas激活可促进血肿吸收，改善神经功能缺损，缓解神经元凋亡，减少神经炎症，并通过Akt/Nrf2信号通路调节ICH后小胶质细胞/巨噬细胞的功能和表型。因此，鼻内应用Mas激动剂ACE0991可能为ICH患者的临床治疗提供有希望的策略。
