Role and mechanism of complement C3a receptor in the cognitive impairment of septic rats induced by cecal ligation and perforation
10.16098/j.issn.0529-1356.2023.06.007
- Author:
Ying XU
1
;
Xing ZHENG
1
;
Zong-Zhao HE
1
;
Bin LIU
2
Author Information
1. Department of Emergency
2. Department of Neurosurgery, Qinghai Provincial People' S Hospital
- Publication Type:Journal Article
- Keywords:
Cognitive impairment;
Complement C3a Receptor;
Inflammation;
Rat;
Sepsis;
Western blotting
- From:
Acta Anatomica Sinica
2023;54(6):668-675
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the role of complement C3a receptor (C3aR) in cognitive impairment in rats with sepsis induced by cecal ligation and puncture (CLP), and to explore the possible mechanism. Methods Totally 132 rats were randomly divided into sham operation group (sham group) and sepsis group (CLP group). The initial number of each group was 66 animals, and 22 animals were set at each time point. The SD rat CLP animal model was constructed, and serum and brain (hippocampus and prefrontal cortex) samples were collected at day 1, day 15 and day 30 after operation. The levels of tumor necrosis factor-α(TNF-α), interleukin-1β (IL-1β) and IL-6 in the samples were determined by ELISA. Western blotting detected Tau protein (Tau), phosphorylated Taup-Tauand C3aR expression in brain samples. Totally 66 rats were randomly divided into 3 groups, sham operation group, CLP group and C3aR antagonist(C3aRa) intervention group. On 15th, 17th, and 19th days after CLP, C3aRa intervened in rats, and they received inhibition avoidance test and object recognition test 30 days after CLP. The expressions of C3aR, lonized calcium binding adapter molecule 1(Iba1), GFAP and p-Tau in the hippocampus were detected by immunofluorescence. Results Compared with the sham group, the serum and brain tissue (TNFα, IL-1β and IL-6) of rats in the CLP group first increased and then decreased within 30 days after CLP. In the hippocampus and prefrontal cortex of CLP group, Tau phosphorylation was significantly enhanced at day 30 and day 1 and 15 after surgery, respectively (P<0.05). Compared with the sham group, C3aR protein levels in hippocampus and prefrontal cortex of rats in CLP group increased significantly at day 15 and 30 after operation (P<0.05). Compared with the CLP group, the endogenous C3aR content decreased significantly after C3aRa intervention (P<0.05), and Iba1, GFAP and p-Tau immunostaining were significantly inhibited (P<0.05). The C3aRa intervention in CLP rats reversed the cognitive impairment. Conclusion C3aR plays an important role in the development of biochemical and behavioral changes commonly associated with the onset of sepsis-induced neurodegenerative processes. C3aRa can be injected into the hippocampus to counteract the neurodegenerative process induced by sepsis.
