机构:[1]Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China,麻醉手术科首都医科大学宣武医院[2]Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden,[3]Department of Anatomy, Capital Medical University, Beijing, China
Inflammation is a hallmark of several disease states ranging from neurodegeneration to sepsis but is also implicated in physiological processes like ageing. Non-resolving inflammation and prolonged neuroinflammation are unclear processes implicated in several conditions, including ageing. In this study we studied the long-term effects of endotoxemia, as systemic lipopolysaccharide (LPS) injection, focusing on the role of astrocyte activation and cytokine release in the brain of aged rats. A single dose of LPS (2 mg/kg) or 0.9% saline was injected intraperitoneally in aged rats. Levels of pro-inflammatory cytokines (TNF alpha and IL-1 beta) and NF-kappa B p65 activation were measured systemically and in hippocampal tissue. Astrocytes and cytokines release in the CNS were detected via double immunofluorescence staining at different time-points up to day 30. Serum levels of TNF alpha and IL-1 beta were significantly increased acutely after 30 minutes (p<0.001) and up to 6 hours (p<0.001) following LPS-injection. Centrally, LPS-treated rats showed up-regulated mRNA expression and protein levels of pro-inflammatory cytokines in the hippocampus. These changes associated with astrogliosis in the hippocampus dentate gyrus (DG), IL-1 beta immunoreactivity and elevated NF-kappa B p65 expression up to day 30 post LPS exposure. Overall, these data demonstrate that LPS induces prolonged neuroinflammation and astrocyte activation in the hippocampus of aged rats. Hippocampal NF-kappa B p65 and excessive astrocytes-derived IL-1 beta release may play a pivotal role in regulating long-lasting neuroinflammation.
基金:
National Natural Science Foundation of China [81241096]