Effect of Pathogen Status on the Manifestation of Accelerated Senescence and Murine Senile Amyloidosis in Senescence Accelerated Mouse (SAM)

我们研究了病原体状态对加速衰老和小鼠老年性淀粉样变性（AApoAII淀粉样变性）表现的影响，使用2至11个月大的SAMPX在常规和无特定病原体（SPF）条件下保持。与常规组相比，SPF组中通过分级评分系统测量的加速衰老的皮肤相关表现被显著抑制。雄性组的加速衰老表现明显高于雌性组。在6月龄常规组中，在33%的小鼠中观察到轻度胃肠道AApoAII淀粉样变性。在11月龄的常规组中，在100%的小鼠中观察到累及脾脏和肝脏的全身性AApoAII淀粉样变性。然而，在SPF组中，在任何年龄的小鼠中均未观察到AApoAII淀粉样变性。因此，环境因素在加速衰老和AApoAII淀粉样变性的发病机制中是至关重要的。

We investigated the effect of pathogen status on the manifestation of accelerated senescence and murine senile amyloidosis (AApoAII amyloidosis) , using 2 to 11-month-old SAMPX maintained both in conventional and in specific pathogen free (SPF) conditions. Age-related manifestation of accelerated senescence as measured by the grading score system, was significantly suppressed in the SPF group as compared to the conventional group. Manifestation of accelerated senescence was significantly higher in the male group than in the female group. In the 6-month-old conventional group, mild gastrointestinal AApoAII amyloidosis was observed in 33% of mice. In the 11-month-old conventional group, systemic AApoAII amyloidosis involving the spleen and liver was observed in 100% of mice. However, in the SPF group, no AApoAII amyloidosis was observed in any age of mice. Thus, the environmental factors are critical in the pathogenesis of accelerated senscence and AApoAII amyloidosis.