Fig. 4

CA140 downregulated LPS-induced neuroinflammatory responses with D1R inhibition. a Representative images of proinflammatory cytokine mRNA levels in BV2 microglial cells. b–f BV2 microglial cells were pretreated with LPS (1 μg/mL) or PBS for 30 min, followed by treatment with vehicle (1% DMSO) or LE300 (a D1R antagonist, 10 μM) for 5.5 h 30 min. Total RNA was then isolated, and proinflammatory cytokine levels were measured by RT-PCR (IL-1β: con, n = 20; LPS, n = 20; LPS + CA140, n = 20; COX-2, IL-6, iNOS, and TNF-alpha: con, n = 10; LPS, n = 10; LPS + CA140, n = 10). g–h BV2 microglial cells were pretreated with LPS (1 μg/mL) or PBS for 30 min, followed by treatment with vehicle (1% DMSO) or LE300 (10 μM) for 30 min and finally CA140 (10 μM) or vehicle (1% DMSO) for 5 h. Total RNA was then isolated, and IL-1β mRNA levels were measured by RT-PCR (con, n = 16; LPS, n = 16; LPS + CA140, n = 16). i–n BV2 microglial cells were pretreated with LPS (1 μg/mL) or PBS for 30 min, followed by treatment with vehicle (1% DMSO) or SCH23390 (a D1R antagonist, 30 μM) for 5.5 h. Total RNA was then isolated, and proinflammatory cytokine levels were measured by RT-PCR (con, n = 12; LPS, n = 12; LPS + CA140, n = 12). o–p BV2 microglial cells were pretreated with LPS (1 μg/ml) or PBS for 30 min, followed by treatment with SCH23390 (30 μM) or vehicle (1% DMSO) for 30 min and finally CA140 (10 μM) or vehicle (1% DMSO) for 5 h. Total RNA was then isolated, and IL-1β mRNA levels were measured by RT-PCR (con, n = 14; LPS, n = 14; LPS + CA140, n = 14). *p < 0.05, **p < 0.001, ***p < 0.0001