Fig. 3: α7nAChR regulates CXCL12 and HSC quiescence in the endosteal BM niche.
From: Cholinergic signals preserve haematopoietic stem cell quiescence during regenerative haematopoiesis
a CXCL12 concentration in BM supernatant of chimeric mice 16 weeks after transplantation (N = 5; P = 0.0003). b Cxcl12 mRNA expression (qPCR) in endosteal and central BM Nes-GFP-positive (+) or negative (−) CD45−CD31−Ter119− stromal cells from Nes-gfp;Gfra2−/− mice or control Nes-gfp;Gfra2+/− mice (N = 6; P = 0.005). c Cxcl12 mRNA expression in BM stromal Nes-GFPhi/lo cells (N = 3). d CXCL12 concentration in BM supernatant after in vivo treatment with cholinergic nicotinic or muscarinic antagonists, or saline (N = 7, 4, 4; P = 0.04). e CXCL12 secretion by MS-5 murine BM stromal cells treated for 24 h with nicotine, acetylcholine (ACh), the muscarinic antagonist atropine (10 µM) or vehicle (N = 9 technical replicates; P < 0.0001). f CXCL12 secretion in primary BM cultures from Gfra2−/−, Chrna7−/− or control Gfra2+/− mice (N = 12; P = 0.004). g CXCL12 concentration in BM supernatant of Chrna7−/− or WT mice (N = 6; P = 0.01). h, i mRNA expression of (h, N = 4,5) Neurturin (Nrtn) and (I, N = 7) its receptor Gfra2 in BM of WT mice 7 days after 5-fluororacil (5-FU) or control treatment. j Circulating white blood cells (WBCs) before and until 28 days after 5-FU treatment of Gfra2−/− (N = 13), Chrna7−/− (N = 7) or control mice (N = 21 pooled from all experiments). k Cell cycle profiles of endosteal BM HSPCs 4 weeks after transplantation (Gfra2+/− → WT, N = 3; Gfra2−/− → WT, N = 3; WT → Gfra2−/−, N = 4). l Ratio of quiescent HSCs in the endosteal or central BM of Chrna7−/− or WT mice (N = 3, P = 0.02). m Cell cycle profiles of endosteal BM HSCs 4 weeks after transplantation into LepR-Cre;Chrna7f/f mice (N = 6), Nes-CreERT2;Chrna7f/f mice (N = 3) or control littermates (N = 10 pooled from two independent experiments). a–i and l Each dot is a mouse. Data are mean of biological replicates ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001. a–d and f ANOVA and Bonferroni’s multiple comparisons test, g–i Unpaired two-tailed t-test, e and k–m ANOVA and Tukey’s multiple comparisons test.
