Physiogenex SAS, F-31750 Escalquens, France.
Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, F-59000 Lille, France.
Viruses. 2022 Sep 17;14(9):2067. doi: 10.3390/v14092067.
Obese patients with non-alcoholic steatohepatitis (NASH) are prone to severe forms of COVID-19. There is an urgent need for new treatments that lower the severity of COVID-19 in this vulnerable population. To better replicate the human context, we set up a diet-induced model of obesity associated with dyslipidemia and NASH in the golden hamster (known to be a relevant preclinical model of COVID-19). A 20-week, free-choice diet induces obesity, dyslipidemia, and NASH (liver inflammation and fibrosis) in golden hamsters. Obese NASH hamsters have higher blood and pulmonary levels of inflammatory cytokines. In the early stages of a SARS-CoV-2 infection, the lung viral load and inflammation levels were similar in lean hamsters and obese NASH hamsters. However, obese NASH hamsters showed worse recovery (i.e., less resolution of lung inflammation 10 days post-infection (dpi) and lower body weight recovery on dpi 25). Obese NASH hamsters also exhibited higher levels of pulmonary fibrosis on dpi 25. Unlike lean animals, obese NASH hamsters infected with SARS-CoV-2 presented long-lasting dyslipidemia and systemic inflammation. Relative to lean controls, obese NASH hamsters had lower serum levels of angiotensin-converting enzyme 2 activity and higher serum levels of angiotensin II-a component known to favor inflammation and fibrosis. Even though the SARS-CoV-2 infection resulted in early weight loss and incomplete body weight recovery, obese NASH hamsters showed sustained liver steatosis, inflammation, hepatocyte ballooning, and marked liver fibrosis on dpi 25. We conclude that diet-induced obesity and NASH impair disease recovery in SARS-CoV-2-infected hamsters. This model might be of value for characterizing the pathophysiologic mechanisms of COVID-19 and evaluating the efficacy of treatments for the severe forms of COVID-19 observed in obese patients with NASH.
非酒精性脂肪性肝炎 (NASH) 的肥胖患者易患严重的 COVID-19 。迫切需要新的治疗方法来降低这种脆弱人群 COVID-19 的严重程度。为了更好地模拟人类环境,我们在金黄地鼠中建立了一种与血脂异常和 NASH 相关的饮食诱导肥胖模型(金黄地鼠已知是 COVID-19 的一种相关临床前模型)。20 周的自由选择饮食可诱导金黄地鼠肥胖、血脂异常和 NASH(肝脏炎症和纤维化)。肥胖 NASH 金黄地鼠的血液和肺部炎症细胞因子水平较高。在 SARS-CoV-2 感染的早期阶段,瘦型金黄地鼠和肥胖 NASH 金黄地鼠的肺部病毒载量和炎症水平相似。然而,肥胖 NASH 金黄地鼠的恢复情况较差(即感染后 10 天肺部炎症的缓解程度较低(dpi),感染后 25 天体重恢复情况较低)。肥胖 NASH 金黄地鼠在 dpi 25 时还表现出更高的肺部纤维化水平。与瘦型动物不同,感染 SARS-CoV-2 的肥胖 NASH 金黄地鼠表现出持久的血脂异常和全身炎症。与瘦型对照组相比,肥胖 NASH 金黄地鼠的血清血管紧张素转换酶 2 活性水平较低,血管紧张素 II 水平较高(血管紧张素 II 是一种有利于炎症和纤维化的成分)。尽管 SARS-CoV-2 感染导致体重早期减轻和体重不完全恢复,但肥胖 NASH 金黄地鼠在 dpi 25 时仍表现出持续的肝脂肪变性、炎症、肝细胞气球样变和明显的肝纤维化。我们的结论是,饮食诱导的肥胖和 NASH 会损害 SARS-CoV-2 感染金黄地鼠的疾病恢复。该模型可能有助于描述 COVID-19 的病理生理机制,并评估针对肥胖 NASH 患者中观察到的严重 COVID-19 形式的治疗效果。