Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming 650118, China.
Int J Mol Sci. 2024 Jan 13;25(2):997. doi: 10.3390/ijms25020997.
Patients with COVID-19 have been reported to experience neurological complications, although the main cause of death in these patients was determined to be lung damage. Notably, SARS-CoV-2-induced pathological injuries in brains with a viral presence were also found in all fatal animal cases. Thus, an appropriate animal model that mimics severe infections in the lungs and brain needs to be developed. In this paper, we compared SARS-CoV-2 infection dynamics and pathological injuries between C57BL/6Smoc- transgenic hACE2-C57 mice and Syrian hamsters. Importantly, the greatest viral distribution in mice occurred in the cerebral cortex neuron area, where pathological injuries and cell death were observed. In contrast, in hamsters, viral replication and distribution occurred mainly in the lungs but not in the cerebrum, although obvious ACE2 expression was validated in the cerebrum. Consistent with the spread of the virus, significant increases in IL-1β and IFN-γ were observed in the lungs of both animals. However, in hACE2-C57 mice, the cerebrum showed noticeable increases in IL-1β but only mild increases in IFN-γ. Notably, our findings revealed that both the cerebrum and the lungs were prominent infection sites in hACE2 mice infected with SARS-CoV-2 with obvious pathological damage. Furthermore, hamsters exhibited severe interstitial pneumonia from 3 dpi to 5 dpi, followed by gradual recovery. Conversely, all the hACE2-C57 mice experienced severe pathological injuries in the cerebrum and lungs, leading to mortality before 5 dpi. According to these results, transgenic hACE2-C57 mice may be valuable for studying SARS-CoV-2 pathogenesis and clearance in the cerebrum. Additionally, a hamster model could serve as a crucial resource for exploring the mechanisms of recovery from infection at different dosage levels.
据报道,COVID-19 患者会出现神经系统并发症,尽管这些患者的主要死亡原因被确定为肺部损伤。值得注意的是,在所有致命的动物病例中,也发现了 SARS-CoV-2 在存在病毒的情况下对大脑造成的病理损伤。因此,需要开发一种合适的动物模型,以模拟肺部和脑部的严重感染。在本文中,我们比较了 C57BL/6Smoc- 转基因 hACE2-C57 小鼠和叙利亚仓鼠中 SARS-CoV-2 的感染动力学和病理损伤。重要的是,在小鼠中,最大的病毒分布发生在大脑皮层神经元区域,在该区域观察到病理损伤和细胞死亡。相比之下,在仓鼠中,病毒复制和分布主要发生在肺部,而不是大脑,尽管大脑中验证了明显的 ACE2 表达。与病毒的传播一致,两种动物的肺部均观察到 IL-1β 和 IFN-γ 的显著增加。然而,在 hACE2-C57 小鼠中,大脑显示出明显增加的 IL-1β,但 IFN-γ 仅轻度增加。值得注意的是,我们的研究结果表明,在感染 SARS-CoV-2 的 hACE2 小鼠中,大脑和肺部都是明显的感染部位,且具有明显的病理损伤。此外,仓鼠从 3 dpi 到 5 dpi 表现出严重的间质性肺炎,随后逐渐恢复。相反,所有 hACE2-C57 小鼠的大脑和肺部都经历了严重的病理损伤,导致在 5 dpi 之前死亡。根据这些结果,转基因 hACE2-C57 小鼠可能有助于研究 SARS-CoV-2 在大脑中的发病机制和清除机制。此外,仓鼠模型可以作为探索不同剂量水平下感染恢复机制的重要资源。