Low-input Nucleus Isolation and Multiplexing with Barcoded Antibodies of Mouse Sympathetic Ganglia for Single-nucleus RNA Sequencing
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ABSTRACT: The cardiac autonomic nervous system is crucial in controlling cardiac function, such as heart rate and cardiac contractility, and is divided into sympathetic and parasympathetic branches. Normally, there is a balance between these two branches to maintain homeostasis. However, cardiac disease states such as myocardial infarction, heart failure, and hypertension can induce the remodeling of cells involved in cardiac innervation, which is associated with an adverse clinical outcome. Although there are vast amounts of data for the histological structure and function of the cardiac autonomic nervous system, its molecular biological architecture in health and disease is still enigmatic in many aspects. Novel technologies such as single-cell RNA sequencing (scRNA-seq) hold promise for the genetic characterization of tissues at single-cell resolution. However, the relatively large size of neurons may impede the standardized use of these techniques. Here, this protocol exploits droplet-based single-nucleus RNA sequencing (snRNA-seq), a method to characterize the biological architecture of cardiac sympathetic neurons in health and disease. A stepwise approach is demonstrated to perform snRNA-seq of the bilateral superior cervical (SCG) and stellate ganglia (StG) dissected from adult mice. This method enables long-term sample preservation, maintaining an adequate RNA quality when samples from multiple individuals/experiments cannot be collected all at once within a short period of time. Barcoding the nuclei with hashtag oligos (HTOs) enables demultiplexing and the trace-back of distinct ganglionic samples post sequencing. Subsequent analyses revealed successful nuclei capture of neuronal, satellite glial, and endothelial cells of the sympathetic ganglia, as validated by snRNA-seq. In summary, this protocol provides a stepwise approach for snRNA-seq of sympathetic extrinsic cardiac ganglia, a method that has the potential for broader application in studies of the innervation of other organs and tissues.
Project description:The autonomic nervous system is derived from the neural crest and supplies motor innervation to the smooth muscle of visceral organs, including the lower urinary tract (bladder and urethra, LUT). In rodents, autonomic innervation of the LUT is supplied by the major pelvic ganglia (PG) that lie near the neck of the bladder and proximal urethra. Compared to other autonomic ganglia, the PG are unique in that they harbor both sympathetic and parasympathetic neurons. The coordinated activity of PG neurons is critical for normal functioning of the LUT – however, surprisingly little is known about how PG neuronal diversity is established or what molecular factors control PG development. In this study we conducted transcriptome profiling of Sox10-H2BVenus+ sacral neural crest (NC) progenitors to discover candidate genes involved in PG neurogenesis.
Project description:The sympathetic nervous system controls a wide spectrum of bodily functions including operation of vessels, cardiac rhythm, and the “flight or fight response”. Sympathetic neurons, which are neural crest-derived, develop in coordination with presynaptic motor nerves extending from the central nervous system (CNS). By using nerve-selective genetic ablations, we revealed that sympathetic ganglia development depends on CNS-derived motor innervation. In the absence of preganglionic motor nerves, trunk sympathetic chain ganglia were fragmented and smaller in size, while cervical ganglia were severely misshapen. Sympathetic neurons were misplaced along sensory fibers and projected towards abnormal paths, in some cases invading the sensory dorsal root ganglia. The misplaced progenitors of sympathoblasts corresponded to the nerve-associated, neural crest-derived Schwann cell precursors (SCPs). Notably, we found that SCPs activate the autonomic marker PHOX2B while migrating along motor nerves towards the region of the dorsal aorta in wildtype embryos, suggesting that SCP differentiate into sympathetic neurons while still nerve-associated in motor-ablated embryos. Ligand-receptor prediction from single cell transcriptomic data coupled with functional studies identified Semaphorin 3A/3F as candidate motor nerve-derived signals influencing neural crest migration along axons. Thus, motor nerves control the placement of sympathoblasts and their subsequent axonal navigation during critical periods of sympathetic chain development.
Project description:The sacral autonomic outflow has been deemed parasympathetic and its ganglionic relay, the pelvic ganglion, common to the lumbar outflow, a mixed sympathetic/parasympathetic ganglion. Here we find that it is entirely and equally distinct from sympathetic and parasympathetic ganglia based on its transcriptome, but related to sympathetic ones by the criterion of its top genes. Thus, the pelvic ganglion appears as a divergent outpost of the sympathetic chains.
Project description:Transcriptom analysis of stellate sympathetic ganglia after 8 weeks of cardiac pressure overload caused by transverse aortic constriction. Comparative transcriptome analysis was determined using the GeneChip Mouse Genome 430 2.0 Array (Affymetrix, Santa Clara, CA, USA). Six microarrays from stellate sympathetic ganglia of mice were performed 8 weeks after transverse aortic constriction or sham operation.
Project description:Cardiac autonomic neurons control cardiac contractility. Dysregulation of the autonomic nervous system can lead to sympathetic overdrive resulting in heart failure and an increased incidence of fatal arrhythmias. Here, we introduce innervated engineered human myocardium (iEHM), a novel model of neuro-cardiac junctions, constructed by fusion of a bioengineered neural organoid (BENO) patterned to autonomic nervous system and engineered human myocardium (EHM). Projections of sympathetic neurons into engineered human myocardium formed presynaptic terminals in close proximity to cardiomyocytes and an extensive vascular network co-developing in the tissues. Contractile responses to optogenetic stimulation of the accordingly engineered neuronal component demonstrated functionality of the engineered neuro-cardiac junctions in iEHM. This model will serve as a human surrogate system to delineate neuron and cardiac cell contribution to brain and heart diseases and is an important step towards engineering a human brain to heart axis in a dish.
Project description:This study aimed to quantify the regulation of transcripts in the hairy skin of the back of adult rats in the condition of loss of sensory and autonomic (sympathetic) innervation (i.e., denervated). Denervated skin has reduced wound healing capacity, reduced proliferation of epidermal progenitor cells, and also expresses factors that regulate ingrowth of sensory and sympathetic axons from neighboring regions of innervated skin. It was expected that this quantification f transcript regulation would offer insight into the general and specific mechanisms that may contribute to these important biological processes.
Project description:The sympathetic nervous system innervates peripheral organs to regulate their function and maintain homeostasis, whereas target cells also produce neurotrophic factors to promote sympathetic innervation1,2. The molecular basis of this bi-directional communication is unknown. Here we use thermogenic adipose tissue from mice as a model system to show that T cells, specifically T cells, have a crucial role in promoting sympathetic innervation, at least in part by driving the expression of TGF1 in parenchymal cells via the IL-17 receptor complex (IL-17RC). Ablation of IL-17RC specifically in adipose tissue reduces expression of TGF1 in adipocytes, impairs local sympathetic innervation and causes obesity and other metabolic phenotypes that are consistent with defective thermogenesis; innervation can be fully rescued by restoring TGF1 expression. Ablating cells and the IL-17RC signalling pathway also impairs sympathetic innervation in salivary glands and the lungs. These findings demonstrate coordination between T cells and parenchymal cells to regulate sympathetic innervation.
Project description:Transcriptom analysis of stellate sympathetic ganglia after 8 weeks of cardiac pressure overload caused by transverse aortic constriction.
Project description:The sympathetic nervous system innervates peripheral organs to regulate their function and maintain homeostasis, whereas target cells also produce neurotrophic factors to promote sympathetic innervation. The molecular basis of this bi-directional communication remains to be fully elucidated. We use thermogenic adipose tissue as a model system to show that T cells, specifically gdT cells, play a critical role in promoting sympathetic innervation, at least in part through driving TGFβ1 expression in parenchymal cells via IL-17 Receptor C. Adipose-specific ablation of IL-17 Receptor C reduces TGFβ1 expression in adipocytes, impairs local sympathetic innervation and causes obesity and other metabolic phenotypes consistent with defective thermogenesis; innervation can be fully rescued by restoring TGFβ1 expression. Ablating gdT cells and the IL-17 Receptor C signaling pathway also impairs sympathetic innervation in salivary glands and the lung. These findings demonstrate T cell/parenchymal cell coordination to regulate sympathetic innervation.
Project description:Alterations in autonomic function are known to occur in cardiac conditions including sudden cardiac death. Cardiac stimulation via sympathetic neurons can potentially trigger arrhythmias. Dissecting direct neural-cardiac interactions at the cellular level is technically challenging and understudied due to the lack of experimental model systems and methodologies. Here we demonstrate the utility of optical interrogation of sympathetic neurons and their effects on macroscopic cardiomyocyte network dynamics to address research targets such as the effects of adrenergic stimulation via the release of neurotransmitters, the effect of neuronal numbers on cardiac wave behaviour and the applicability of optogenetics in mechanistic in vitro studies. We present novel methodologies to study neuron-cardiomyocyte interactions involving optogenetic selective probing and all-optical electrophysiology to measure electrical activity in an automated fashion, illustrating the power and high-throughput capability of such interrogations. We present new findings on how neurons impact cardiac macroscopic wave properties, the links between neuron density and cardiac firing rates as well as the challenges and benefits of macroscopic co-cultures as experimental model systems.