Fig. 5

Upregulation of Sur1-Trpm4 channels in TLR4-activated murine N9 microglia. a Phase contrast images of N9 microglia under control (CTR) conditions (left) and 24 h after LPS treatment (1 μg/mL) (right). b Change in mRNA for Abcc8, Trpm4, and Kcnj11 in N9 microglia activated by ligation of TLR4 with LPS (1 μg/mL) for 24 h; induction of Il-6 mRNA was used as a positive control; six replicates; **p < 0.01; the dotted line indicates basal level of expression. c Immunoblots (left panel) and quantification (right panel) for Sur1 and Trpm4 of immunoisolates from N9 microglial lysates under control conditions (CTR) and following TLR4 activation for 24 h (LPS), with omission of IP antibody (Ab′) shown as a negative control; for co-immunoprecipitation (Co-IP), immunoisolation was performed using anti-Sur1 antibody and immunoblot was performed using anti-Trpm4 antibody; three replicates; *p < 0.05. d, e Whole-cell Cs⁺ currents at low (left) and high (right) temporal resolution during ramp pulses (−100 to +100 mV in 500 ms, repeated every 15 s; holding potential, −50 mV) in control N9 microglia (CTR) and N9 microglia after TLR4 activation by LPS (1 μg/mL) for 24 h; Sur1 was activated by diazoxide (100 μM) and inhibited by glibenclamide (5 μM). f Magnitude of the inward current density at −50 mV (I _Sur1-Trpm4) activated by diazoxide in control versus TLR4-activated N9 microglia; same experiment as in d and e. g Magnitude of the membrane capacitance (C _m) in control versus TLR4-activated N9 microglia; same experiment as in d and e; 14–16 cells/condition