背景:在人类中,慢性肝病(CLD)是一种严重的临床疾病,有许多危及生命的并发症。目前,没有治疗方法可以阻止或减缓肝纤维化的进展。CLD的实验小鼠模型,通过反复腹腔注射四氯化碳(CCL4)和D-半乳糖胺(D-GalN)诱导,可用于评估无法在人类中进行的治疗。这些动物模型的主要缺点是取决于动物品系的肝纤维化进展的不同动力学。服用肝毒素,它的剂量,中毒的持续时间,和注射频率。这项研究的目的是描述和比较CCl4和D-GalN诱导的BALB/c小鼠和SpragueDawley大鼠CLD模型中病理变化的动态。我们定义了这些变化的开始和持续时间,并在分析的CLD模型中提出了治疗干预的最佳时间。
方法:通过在小鼠(每5天12.5μL/100gbw)和大鼠(每周两次25-100μL/100gbw)中反复腹膜内注射CCl4诱导CLD小鼠(每周两次75mg/100gbw)和大鼠(每周两次25mg/100gbw)和D-GalN。在中毒的第2、4、6、8、10和12周收集血液和肝脏样品。通过使用全血细胞计数和肝功能血液测试以及通过分析组织病理学变化来评估肝损伤及其进展。包括纤维化,增殖活性,凋亡,星状细胞激活,和基因表达。
结果:在用CCl4治疗的小鼠和大鼠中,从中毒的第2到第4周,在大多数中心周围区域观察到早期纤维化。在中毒的第6周时,大鼠和小鼠均出现了已建立的纤维化。不完全肝硬化,定义为偶尔出现肝硬化结节,在中毒的第12周观察到大鼠。CCl4处理的动物的肝纤维化动力学大于D-GalN组。在D-GalN中毒的大鼠和小鼠中,在中毒的第4周和第10周观察到肝纤维化的最初迹象,分别。大鼠在D-GalN中毒8周后出现早期纤维化。胶原蛋白沉积的进展伴随着组织学变化以及某些基因和血液肝脏参数的改变。
结论:CCl4治疗的啮齿动物的肝纤维化动态大于D-GalN治疗的啮齿动物。在CCl4模型中,需要进行两次适当的治疗干预,这在不同程度上反映了真实的临床情况,并且可能在获得的结果中存在潜在差异:中毒第4周之前的早期干预(早期纤维化)和中毒第8周之后的晚期干预(当存在已确定的纤维化迹象时)。D-GalN诱导的纤维化的啮齿动物模型由于长的潜伏期和弱的毒性作用而不推荐。
In humans, chronic liver disease (CLD) is a serious clinical condition with many life-threatening complications. Currently, there is no therapy to stop or slow down the progression of liver fibrosis. Experimental mouse models of CLD, induced by repeated intraperitoneal injections of carbon tetrachloride (CCL4) and D-galactosamine (D-GalN), can be used to evaluate therapies that cannot be performed in humans. A major drawback of these animal models is the different dynamics of liver fibrosis progression depending on the animal strain, administered hepatotoxin, its dose, duration of intoxication, and frequency of injections. The aim of this study was to describe and compare the dynamics of progression of pathological changes in the BALB/c mouse and Sprague Dawley rat models of CLD induced by CCl4 and D-GalN. We defined the onset and duration of these changes and suggested the optimal time for therapeutic intervention in the analyzed CLD models.
CLD was induced by repeated intraperitoneal injection of CCl4 in mice (12.5 μL/100 g bw every 5 days) and rats (25-100 μL/100 g bw twice a week) and D-GalN in mice (75 mg/100 g bw twice a week) and rats (25 mg/100 g bw twice a week). Blood and liver samples were collected at weeks 2, 4, 6, 8, 10, and 12 of intoxication. Liver injury and its progression were assessed by using complete blood count and liver function blood tests as well as by analyzing histopathological changes, including fibrosis, proliferation activity, apoptosis, stellate cell activation, and gene expression.
In mice and rats treated with CCl4, early fibrosis was observed in most pericentral areas from week 2 to 4 of intoxication. Established fibrosis developed in both rats and mice at week 6 of intoxication. Incomplete cirrhosis, defined as the presence of occasional cirrhotic nodules, was observed in rats at week 12 of intoxication. The dynamics of liver fibrosis in CCl4-treated animals were greater than in the D-GalN groups. In D-GalN-intoxicated rats and mice, the first signs of liver fibrosis were observed at weeks 4 and 10 of intoxication, respectively. The rats developed early fibrosis after 8 weeks of D-GalN intoxication. The progression of collagen deposition was accompanied by histological changes and alteration of certain genes and blood liver parameters.
The dynamics of liver fibrosis in CCl4 treated rodents is greater than in the D-GalN treated ones. In the CCl4 models, two appropriate times for therapeutic intervention are indicated, which to varying degrees reflect the real clinical situation and may potentially differ in the obtained results: early intervention before week 4 of intoxication (early fibrosis) and late intervention after week 8 of intoxication (when signs of established fibrosis are present). Rodent models of D-GalN-induced fibrosis are not recommended due to the long incubation period and weak toxic effect.