Fig. 4.

ER stress activates hypothalamic NF-κB to affect peripheral physiology. (A and B) C57BL/6 mice received a single injection of TG (1.0 μg) via preimplanted cannula. Hypothalami were harvested for Western blot analysis of NF-κB signaling at the indicated time points after TG injection. Phosphorylated RelA (p-RelA), phosphorylated IκBα (p-IκBα), and total protein levels of IκBα were measured to reflect NF-κB activities. Vehicle injection was used as the negative control (labeled as 0 h). β-actin (β-act) was used as an internal control. (B) p-RelA and p-IκBα levels were normalized by the total protein levels of RelA and β-actin, respectively. *P < 0.05; **P < 0.01; n = 4–6 mice per group; AU, arbitrary unit. (C) Mice received intra-arcuate injections of adenoviruses expressing either HA-tagged ^DNIκBα or GFP. At 1 wk postinjection, hypothalamic sections were immunostained for GFP (Upper) and HA (Lower) to verify the site-specific gene delivery. Nuclear staining with DAPI (blue) labels all of the cells in the sections and is merged with GFP (green) or HA (red) staining. Arc, arcuate nucleus; 3V, third ventricle. (Scale bar = 50 μm.) (D and E) Intra-Arc ^DNIκBα or GFP adenovirus-injected mice received daily injections of TG (1 μg/d) or vehicle (Veh) via third-ventricle cannula for 3 consecutive d. At 2 h after the final injection, mice were examined for GTT. (E) AUC data for GTT. *P < 0.05; n = 6–10 mice per group. (F) ^DNIκBα or GFP adenovirus-injected mice were implanted with third ventricle cannula and intra arterial telemetric BP probe. BP levels were monitored daily for 3 d before and after TG vs. vehicle injection. Data presented are average mean BP (MBP) values over a 2-h period after the final injection on day 3. *P < 0.05; n = 4 mice per group. (Error bars reflect mean ± SEM.)