ESE1 Affects Microglia Activation And Neuronal Apoptosis Through Promoting NF-κB Activation In Response To LPS Injection

Objective: The study was designed to determine the expression and distribution alteration of ESE1 in neuroinflammation induced by lipopolysaccharide(LPS), and to explore the mechanism of ESE1 regulated microglia activation and neuronal apoptosis following the inflammatory response by LPS-induced.Methods 1. LPS injection induced rat neuroinflammatory model was performed in vivo. Fifty-four healthy male Sprague-Dawley rats were randomly divided into 2 groups: LPS injection group(48) and sham group(vehicle-injected group, 6).Western Blot(WB) and immunohistochemistry(IHC) were employed to test the expression and distribution exchanges of ESE1. 2. Double-immunofluorescent staining(IF) was employed to investigate the co-localization of ESE1 with different cellular markers. 3. WB was performed to investigate the expression files of i NOS、cleaved caspase-3、Bax and Bcl-2. IF was performed to test the co-localization of i NOS/Iba-1、i NOS/ESE1、Neu N/cleaved-capase-3、ESE1/cleaved-caspase-3, in order to explore the association of ESE1 with microglia activation and neuronal apoptosis. 4. In vitro, microglia activation was induced in vitro via LPS treatment. WB was employed to investigate the expression of ESE1、i NOS after LPS treatment. We also investigated proinflammatory cytokines release in response to LPS administration. And dual-luciferase reporter assay was used to ininvestigate the transcription activity of NF-κB thus to investigate the role of ESE1 in microglia activation. CM collected from activated microglia was used to stimulate neurons. WB, LDH test and DAPI staining were used to investigate the role of ESE1 in neuronal apoptosis.1. ESE1 was up-regulated and peaked at day 1 after LPS injection, then it gradually decreased to the normal level. 2. ESE1 was co-localized both with Neu N and Iba-1in the rat brain cortex, and the co-localization of ESE1 with Neu N and Iba-1 was increased in response to LPS injection. 3. The expression of i NOS, cleaved-caspase3 were increased and peaked at day 1 in response to LPS injection, and then gradually decreased. Co-localization of i NOS/Iba-1, i NOS/ESE1, Neu N/cleaved-capase-3, ESE1/cleaved-caspase-3 were increased after LPS injection. 4. Results of WB showed that the expression of ESE1 and i NOS in microglia could be induced by LPS. And knocking down ESE1 expression of microglia showed less i NOS expression, less NF-κB transcription activity and less proinflammatory cytokines release. 5. The expression of ESE1, cleaved-caspase3 in neurons under the CM treatment. Knocking down ESE1 expression sufficiently inhibited the level of cleaved-caspase3 and BAX but promoted the level of Bcl-2. We also found that knocking down ESE1 showed less LDH release in response to microglia condition medium. ResultsConclusions The expression of ESE1 was increased in rat brain cortex in response to LPS injection, at the same time, changes of ESE1 were striking in neurons and microglia, instead of astrocytes. ESE1 might play an important role in neuroinflammation and it might be associated with microglia activation and neuronal apoptosis via NF-κB activation.