Fig. 1: Leptin suppresses counter-regulatory responses to fasting.
From: A neural basis for brain leptin action on reducing type 1 diabetic hyperglycemia
a–i Leptin-Cre:Ai9 mice (8–10 weeks of age, males) were used as fed controls (a, f), made type 1 diabetic induced by STZ administration (b, c), subject to overnight fasting (g, h), or treated with i.c.v. leptin infusion (c, h). LepR neurons were shown by Ai9 reporter expression (red) and immunostaining was performed for c-Fos (green) (a–c, f–h). d–i Comparison in the percentage of LepR neurons with c-Fos expression among the indicated groups was shown in T1D mice (d, one-way ANOVA, n = 6/each, F(2, 10) = 136.9, ***P < 0001, control vs STZ-saline; ***P = 0.004, STZ-saline vs STZ-leptin) or controls (i, one-way ANOVA, n = 5/each, F(2, 8) = 44.4, ***P < 0.0001, fed vs fast-saline; *P = 0.0035, fast-saline vs fast-leptin). e Comparison in the number of c-Fos neurons in the Arc in controls, saline, and leptin-treated nonobesity diabetic (NOD) mice (one-way ANOVA, n = 9 for WT and n = 8 for both NOD-saline and NOD-leptin, F(2, 22) = 44.69, ***P < 0.0001, WT vs NOD-saline; ***P = 0.0006, NOD-saline vs NOD-leptin). j, k In mice presented in panels f–i, comparisons were shown in glucose levels between fed and fasting, and between saline and leptin treatment conditions (j, one-way ANOVA, n = 5/each, F(2, 8) = 116.6, ***P < 0.0001, fed vs fast-leptin; ***P < 0.0001, fast-saline vs fast-leptin) and in glucagon levels between saline and leptin-treated groups (k, one-way ANOVA, n = 5/each, F(2, 8) = 4.575, P = 0.1745, fed vs fast-leptin; *P < 0.0427, fast-saline vs fast-leptin). Blood glucose was measured between fed and 8-h fast (from early morning to late afternoon) and blood glucagon was measured at 8-h fasting. l, m In AgRP-Cre GFP-reporter mice, colocalization of c-Fos induction in STZ-T1D was shown in GFP-positive neurons in a series of sections from rostral to caudal Bregma levels (l) and percentage of c-Fos neurons that were colocalized in AgRP and percentage of AgRP neurons were c-Fos positive in T1D mice (m, n = 3/each). 3V the third ventricle, Arc arcuate nucleus, scale bar: 100 µM. All data presented as mean ± SEM.
