Project description:Adrenal gland is the major organ releasing catecholamines and regulating our stress response. The mechanisms balancing adrenal hormone-producing cells and protecting against neuroblastoma or other tumors are still enigmatic. Here we revealed that adrenergic chromaffin cells release serotonin (5HT), which acts upon their immediate progenitor “bridge” cells via 5-hydroxytryptamine receptor 3A (HTR3A). Consistently, the aggressive HTR3Ahigh human neuroblastoma cell lines reduce proliferation in response to HTR3A-specific agonists, suggesting the mechanism of anti-tumor protection. Physiological increase of 5HT in vivo caused prolongation of a cell cycle length in “bridge” progenitors leading to smaller chromaffin population and changing the balance of hormones and behavioral patterns in resulting adult rodents. These behavioral effects and smaller adrenals were mirrored in a progeny of pregnant females subjected to experimental stress, suggesting novel maternal-fetal link controlling developmental adaptations. Finally, these findings corresponded to a size-distribution of adrenals found in wild rodents with different coping strategies.
Project description:Adrenal glands are the major organs releasing catecholamines and regulating our stress response. The mechanisms balancing generation of adrenergic chromaffin cells and protecting against neuroblastoma tumors are still enigmatic. Here we revealed that serotonin (5HT) controls the numbers of chromaffin cells by acting upon their immediate progenitor “bridge” cells via 5-hydroxytryptamine receptor 3A (HTR3A), and the aggressive HTR3Ahigh human neuroblastoma cell lines reduce proliferation in response to HTR3A-specific agonists. In embryos (in vivo), the physiological increase of 5HT caused a prolongation of the cell cycle in “bridge” progenitors leading to a smaller chromaffin population and changing the balance of hormones and behavioral patterns in adulthood. These behavioral effects and smaller adrenals were mirrored in the progeny of pregnant female mice subjected to experimental stress, suggesting a novel maternal-fetal link that controls developmental adaptations. Finally, these results corresponded to a size-distribution of adrenals found in wild rodents with different coping strategies.
Project description:Adrenal chromaffin cells and sympathetic neuron are derived from neural crest precursors and both cell types can give rise to childhood cancer, neuroblastoma. However only limited is known about the mechanism of their development. Better understanding of their transcriptomic profiles during development could gives an insight into the cell fates acquisition as well as the origin of neuroblastoma. Yellow fluorescent protein expressing sympathetic neuroblasts and adrenal chromaffin cells were isolated from E12.5 TH-IRES-Cre;ROSA26-EYFP mouse embryos by fluorescence-activated cell sorting. Transcriptomic profiles of sympathetic neuroblasts and adrenal chromaffin cells from embryonic age (E)12.5 TH-IRES-Cre;ROSA26-EYFP mice were generated by RNA sequencing, in four paired biological replicates.
Project description:Pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta/alpha (IL1beta/alpha) modulate catecholamine secretion, and long-term gene regulation, in chromaffin cells of the adrenal medulla. Interleukin-6 (IL6), also released during inflammation, affects transcriptional responses in primary chromaffin cells, and may coordinate immune and autonomic adrenomedullary responses via an autocrine mechanism, as TNFalpha itself strongly induces IL6 expression in chromaffin cells, which in turn express receptors responsive to IL6. We have examined the signaling mechanisms employed by IL6 to affect tyrosine hydroxylase (TH) enzymatic activation, and adrenomedullary gene transcription, in cultured bovine chromaffin cells. IL6 caused acute tyrosine/threonine phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), and serine phosphorylation of signal transducer and activator of transcription 3 (STAT3), as do several other first messengers acting on the chromaffin cell, including histamine, nicotine and angiotensin II. IL6 uniquely activated tyrosine phosphorylation of STAT3. Consistent with a short-term ERK1/2 activation, IL6 treatment caused prompt regulation of TH phosphorylation, and up-regulation of genes encoding secreted proteins of the adrenal medulla including galanin, vasoactive intestinal peptide (VIP), gastrin releasing peptide (GRP) and parathyroid hormone-like hormone (PTHLH). We further examined the effects of IL6 treatment on the entire bovine chromaffin cell transcriptome. Of 90 genes up-regulated by IL6, only 16 of which are known targets of IL6 in the immune system. The remaining genes likely represent a combination of novel IL6/STAT3 targets, targets of ERK1/2 shared by other first messengers, and, potentially, IL6-dependent genes activated in a secondary cascade via transcription mediated by IL6-induced transcription factors, such as HIF-1alpha. Notably, genes induced by IL6 represent a cohort with a profile that includes both neuroendocrine-specific genes, including several that are activated by G-protein couple receptor (GPCR) signaling pathways initiated by histamine and pituitary adenylate cyclase-activating polypeptide (PACAP), and some transcripts also activated by cytokines including interferon-alpha (INFalpha and TNFalpha. These results suggest an integrative role for IL6 in overall fine-tuning of the chromaffin cell response to a wide range of physiological and paraphysiological stressors, particularly when immune and endocrine stimuli converge in the adrenal medulla.
Project description:During embryonic development, nerve-associated Schwann cell precursors (SCPs) give rise to chromaffin cells of the adrenal gland via the “bridge” transient stage, according to recent functional experiments and single cell data from humans and mice. However, currently existing data do not resolve the finest heterogeneity of developing chromaffin populations. Here we took advantage of deep SmartSeq2 transcriptomic sequencing to expand our collection of individual cells from developing murine sympatho-adrenal anlage and uncover the microheterogeneity of embryonic chromaffin cells and corresponding developmental paths. After improving our atlas of sympatho-adrenal development and performing experimental validations, we discovered that SCPs in the local nerve show high degree of microheterogeneity corresponding to early biases towards either Schwann or chromaffin terminal fates. Furthermore, we found that a post-“bridge” population of developing chromaffin cells gives rise to persisting immature chromaffin cells and the two terminal populations (adrenergic and noradrenergic) via diverging differentiation paths. Taken together, we provide a thorough identification of novel markers of adrenergic and noradrenergic populations in developing adrenal glands and report novel differentiation micro-paths leading to them.
Project description:Chromaffin cells were selected from dissociated postnatal mouse adrenals by immunopanning using L1CAM, expanded in sphere cultures and analyzed by RNA sequencing
Project description:Multipotent Schwann cell precursors generate steroid-producing cells of the adrenal cortex and chromaffin cells of the adrenal medulla