Fig. 6: DMX responses to stress and stimulates hepatic LCN2.
From: Stress increases hepatic release of lipocalin 2 which contributes to anxiety-like behavior in mice
a Upper, Retro-tracing of liver-innerved nuclei by pseudo-rabies virus (PRV) system. Middle, viral injection sites in liver tissues. Lowe panels, transsynaptic expression of PRV particles in brain stem nuclei. Triplicated studies were performed. Scale bars, 500 μm on middle pane and 100 μm on lower panel. PSol parasolitary nucleus, Cu cuneate nucleus, ECu external cuneate nucleus, AP area postrema, ML medial lemniscus, PY pyramidal tract. b Neuronal activation profile of DMX under CRS. 12 N, hypoglossal nucleus. Scale bar, 100 μm. c Quantification of cFos activity showed more neuron activations in DMX not other nuclei after CRS. Multiple t-test (in two-sided manner) was used for between-group comparison, with Holm–ŠÃdák method for correction. N = 7 mice in each group. d cFos activity of ChAT+ neurons in DMX of CRS mice. Two-sided unpaired t-test, t(8) = 7.598, P < 0.0001. N = 5 mice in each group. e Timelines for optogenetic activation of liver-innervating DMX neurons. f Viral infection sites within DMX. Triplicated studies were performed. Scale bar, 250 μm (left) and 25 μm (right). g Light stimulation induced hepatic LCN2 biosynthesis. One-way ANOVA, F(3,16) = 219.2, P < 0.0001. h Circulating LCN2 was also elevated upon DMX activation. One-way ANOVA, F(3,16) = 78.73, P < 0.0001. N = 5 mice per group in (g, h). i DMX activation induced the avoidance toward the central region of the open field in unstressed mice. One-way ANOVA, F(3,24) = 11.75, P < 0.0001. j DMX activation decreased time spent in the open arm of the elevated plus-maze. One-way ANOVA, F(3,24) = 20.93, P < 0.0001. k DMX activation led to lower preference toward the light box. One-way ANOVA, F(3,24) = 15.82, P < 0.0001. N = 7 mice per group in (i–k). l Timelines for optogenetic inhibition of liver-innervating DMX neurons. m Viral infection site within DMX. Triplicated studies were performed. Scale bar, 250 μm (left) and 25 μm (right). n Light-mediated neuronal inhibition prevented hepatic LCN2 surge in CRS mice. One-way ANOVA, F(3,16) = 1357, P < 0.0001. o Circulating LCN2 in CRS-treated animals was also repressed upon DMX inhibition. One-way ANOVA, F(3,16) = 30.69, P < 0.0001. N = 5 mice per group in (n, o). p DMX inhibition rescued the avoidance toward the central region of the open field in CRS mice. One-way ANOVA, F(3,24) = 12.17, P < 0.0001. q DMX inhibition recovered normal time spent in the open arm of the elevated plus-maze. One-way ANOVA, F(3,24) = 13.92, P < 0.0001. r DMX inhibition recovered normal preference toward the light box of CRS mice. One-way ANOVA, F(3,24) = 20.54, P < 0.0001. N = 7 mice per group in (p–r). Exact P-values were indicated using Tukey’s post-hoc comparison in (g–r). All data were presented as mean ± sem. Source data are provided as a Source Data file.
