PDF(Pubmed)
Abstract：
To study the impact of necroptosis-induced chronic inflammation on age-related diseases and aging, two knockin mouse models (Ripk3-KI and Mlkl-KI) were generated that overexpress two genes involved in necroptosis (Ripk3 or Mlkl) when crossed to Cre transgenic mice. Crossing Ripk3-KI or Mlkl-KI mice to albumin-Cre transgenic mice produced hepatocyte specific hRipk3-KI or hMlkl-KI mice, which express the two transgenes only in the liver. Ripk3 and Mlkl proteins were overexpressed 10- and fourfold, respectively, in the livers of the hRipk3-KI or hMlkl-KI mice. Treating young (2-month) hRipk3-KI or hMlkl-KI mice with carbon tetrachloride (CCl4), a chemical inducer of oxidative stress, resulted in increased necroptosis (Mlkl-oligomers) and inflammation in the liver compared to control mice receiving CCl4. Mlkl-oligomerization also was significantly increased in old (18-month) hRipk3-KI and hMlkl-KI mice compared to old control (Cre negative, Ripk3-KI and Mlkl-KI) mice. The increase in necroptosis was associated with an increase in inflammation, e.g., inflammatory cytokines (TNFα, IL-6) and macrophage markers (F4/80, CD68). Importantly, steatosis (triglycerides) and fibrosis (e.g., picrosirius red staining, hydroxyproline levels, and transcripts for TGFβ, Col1α1, and Col3α1) that increase with age were significantly higher in the livers of the old hRipk3-KI or hMlkl-KI mice compared to old control mice. In addition, markers of cellular senescence were significantly increased in the livers of the old hRipk3-KI and hMlkl-KI mice. Thus, the first mouse models have been developed that allow researchers to study the impact of inducing necroptosis in specific cells/tissues on chronic inflammation in aging and age-related diseases.
摘要：
研究坏死性凋亡诱导的慢性炎症对年龄相关疾病和衰老的影响,产生了两个敲入小鼠模型（Ripk3-KI和Mlkl-KI），当与Cre转基因小鼠杂交时，它们过表达了两个参与坏死的基因（Ripk3或Mlkl）。使Ripk3-KI或Mlkl-KI小鼠与白蛋白-Cre转基因小鼠交叉产生肝细胞特异性hRipk3-KI或hMlkl-KI小鼠，仅在肝脏中表达这两种转基因。Ripk3和Mlkl蛋白被过表达10倍和4倍，分别,在hRipk3-KI或hMlkl-KI小鼠的肝脏中。用四氯化碳（CCl4）治疗年轻（2个月）hRipk3-KI或hMlkl-KI小鼠，氧化应激的化学诱导剂，与接受CCl4的对照小鼠相比,导致肝脏中的坏死(Mlkl-寡聚物)和炎症增加。与老年对照相比，老年（18个月）hRipk3-KI和hMlkl-KI小鼠的Mlkl-寡聚化也显着增加（Cre阴性，Ripk3-KI和Mlkl-KI)小鼠。坏死的增加与炎症的增加有关，例如，炎性细胞因子(TNFα，IL-6）和巨噬细胞标记（F4/80，CD68）。重要的是,脂肪变性(甘油三酯)和纤维化(例如，黄连红染色,羟脯氨酸水平,和TGFβ的转录本，与老年对照小鼠相比，老年hRipk3-KI或hMlkl-KI小鼠的肝脏中随年龄增长的Col1α1和Col3α1）明显更高。此外,在老hRipk3-KI和hMlkl-KI小鼠的肝脏中，细胞衰老的标志物显着增加。因此，已经开发了第一批小鼠模型，使研究人员能够研究在特定细胞/组织中诱导坏死对衰老和与年龄相关的疾病的慢性炎症的影响。
