Xiu-Li Yang1,2, Chi Kyung Kim1,2,3, Tae Jung Kim1,2, Jing Sun2, Doeun Rim1, Young-Ju Kim1,2, Sang-Bae Ko1,2, Hyunduk Jang1,2, Byung-Woo Yoon4,5,6. 1. Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. 2. Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea. 3. Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03087, Republic of Korea. 4. Department of Neurology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. bwyoon@snu.ac.kr. 5. Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea. bwyoon@snu.ac.kr. 6. Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03087, Republic of Korea. bwyoon@snu.ac.kr.
Abstract
OBJECTIVE: The aim of this study was to investigate whether fimasartan, a novel angiotensin II receptor blocker, modulates hemolysate-induced inflammation in astrocytes. METHODS: We stimulated astrocytes with hemolysate to induce hemorrhagic inflammation in vitro. Astrocytes were pretreated with fimasartan and then incubated with hemolysate at different durations. Anti-inflammatory cell signaling molecules including Akt, extracellular signal regulated kinase (ERK), NFκB and cyclooxygenase-2 (COX-2) were assessed by western blotting. Pro-inflammatory mediators were evaluated by real-time RT-PCR and ELISA. RESULTS: The stimulation by hemolysate generated a robust activation of inflammatory signaling pathways in astrocytes. Hemolysate increased the phosphorylation of Akt at 1 h, and ERK1/2 at 20 min compared with the control group and promoted the degradation of IκBα. Pretreated fimasartan significantly decreased hemolysate-induced phosphorylation of Akt and ERK1/2. In addition, fimasartan also suppressed NFκB-related inflammatory pathways induced by hemolysate, including reduction of the gene expression of NFκB, and decreased nuclear translocation of NFκB and degradation of IκB. This reduction of inflammatory upstream pathways decreased the expression of inflammatory end-products: COX-2 and interleukin-1 (IL-1β). Furthermore, the expression of COX-2 was attenuated by both Akt inhibitor (LY294002) and ERK inhibitor (U0126), and IκBα degradation was suppressed by LY294002. CONCLUSIONS: These results demonstrate that pretreatment with fimasartan to astrocytes suppresses the inflammatory responses induced by hemolysate. Akt, ERK and NFκB were associated with hemolysate-induced COX-2 and IL-1β expression. Based on these mechanisms, fimasartan could be a candidate anti-inflammatory regulator for the treatment of intracerebral hemorrhage.
OBJECTIVE: The aim of this study was to investigate whether fimasartan, a novel angiotensin II receptor blocker, modulates hemolysate-induced inflammation in astrocytes. METHODS: We stimulated astrocytes with hemolysate to induce hemorrhagic inflammation in vitro. Astrocytes were pretreated with fimasartan and then incubated with hemolysate at different durations. Anti-inflammatory cell signaling molecules including Akt, extracellular signal regulated kinase (ERK), NFκB and cyclooxygenase-2 (COX-2) were assessed by western blotting. Pro-inflammatory mediators were evaluated by real-time RT-PCR and ELISA. RESULTS: The stimulation by hemolysate generated a robust activation of inflammatory signaling pathways in astrocytes. Hemolysate increased the phosphorylation of Akt at 1 h, and ERK1/2 at 20 min compared with the control group and promoted the degradation of IκBα. Pretreated fimasartan significantly decreased hemolysate-induced phosphorylation of Akt and ERK1/2. In addition, fimasartan also suppressed NFκB-related inflammatory pathways induced by hemolysate, including reduction of the gene expression of NFκB, and decreased nuclear translocation of NFκB and degradation of IκB. This reduction of inflammatory upstream pathways decreased the expression of inflammatory end-products: COX-2 and interleukin-1 (IL-1β). Furthermore, the expression of COX-2 was attenuated by both Akt inhibitor (LY294002) and ERK inhibitor (U0126), and IκBα degradation was suppressed by LY294002. CONCLUSIONS: These results demonstrate that pretreatment with fimasartan to astrocytes suppresses the inflammatory responses induced by hemolysate. Akt, ERK and NFκB were associated with hemolysate-induced COX-2 and IL-1β expression. Based on these mechanisms, fimasartan could be a candidate anti-inflammatory regulator for the treatment of intracerebral hemorrhage.
Authors: Kyle B Walsh; Xiang Zhang; Xiaoting Zhu; Eric Wohleb; Daniel Woo; Long Lu; Opeolu Adeoye Journal: DNA Cell Biol Date: 2019-05-22 Impact factor: 3.311