Low-input Nucleus Isolation and Multiplexing with Barcoded Antibodies of Mouse Sympathetic Ganglia for Single-nucleus RNA Sequencing

Summary

This protocol describes the detailed, low-input sample preparation for single-nucleus sequencing, including the dissection of mouse superior cervical and stellate ganglia, cell dissociation, cryopreservation, nucleus isolation, and hashtag barcoding.

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.

Introduction

The autonomic nervous system (ANS) is a crucial part of the peripheral nervous system that maintains body homeostasis, including the adaption to environmental conditions and pathology¹. It is involved in the regulation of multiple organ systems throughout the body such as the cardiovascular, respiratory, digestive, and endocrine systems. The ANS is divided into sympathetic and parasympathetic branches. Spinal branches of the sympathetic nervous system synapse in ganglia of the sympathetic chain, situated bilaterally in a paravertebral position. The bilateral cervical and thoracic ganglia, especially the StG, are important components participati....

Protocol

This protocol describes all steps required for the snRNA-seq of murine cervical and/or cervicothoracic (stellate) ganglia. Female and male C57BL/6J mice (15 weeks old, n = 2 for each sex) were used. One additional Wnt1-Cre;mT/mG mouse was used to visualize the ganglia for dissection purposes^17,18. This additional mouse was generated by the crossbreeding of a B6.Cg-Tg(Wnt1-cre)2Sor/J mouse and a B6.129(Cg)-Gt(ROSA)26Sortm4(ACTB-tdTomato,-EGFP)Luo/J mouse. All animal experiments were carried out according to the Guide for Care and Use of Laboratory Animals published by NIH and approved by the Animal Ethics Commi....

Results

Quality control analysis of the single-nucleus cDNA library preparation and snRNA-seq
Representative results describe sequencing results of 10,000 captured nuclei in a single pool with a 25,000 reads/nucleus gene expression library and a 5,000 reads/nucleus hashtag library. Figure 3B illustrates the quality control results of the 1^st strand cDNA, gene expression (GEX) library, and HTO library, which were checked with Bioanalyzer. The HTO-derived cDNAs are ex.......

Discussion

Here, a detailed protocol is described that focuses on i) the dissection of adult mouse superior cervical and stellate sympathetic ganglia, ii) the isolation and cryopreservation of the ganglionic cells, iii) nucleus isolation, and iv) nucleus-barcoding with HTO labeling for multiplexing purposes and snRNA-seq.

With this protocol, sympathetic ganglionic cells can easily be obtained by dissociating individual ganglia using commonly used trypsin and collagenase. Long-term preservation of isolate.......

Materials

Name	Company	Catalog Number	Comments
Chemicals and reagents
0.25% Trypsin-EDTA	Thermo Fisher Scientific	25200056
0.4% trypan blue dye	Bio-Rad	1450021
Antibiotic-Antimycotic	Gibco	15240096
B-27	Gibco	A3582801
Collagenase type 2	Worthington	LS004176	use 1,400 U/mL
Dimethyl sulfoxide	Sigma Aldrich	67685
Ethanol absolute ≥99.5%	VWR	VWRC83813.360
Fetal bovine serum (low endotoxin)	Biowest	S1810-500
L-glutamine	Thermo Fisher Scientific	25030024
Neurobasal Medium	Gibco	21103049
Bovine Serum Albumin 10%	Sigma-Aldrich	A1595-50ML	Cell wash buffer
DPBS (Ca2+, Mg2+free)	Gibco	14190-169	Cell wash buffer
Magnesium Chloride Solution, 1 M	Sigma-Aldrich	M1028	Nucleus Lysis buffer
Nonidet P40 Substitute (nonionic detergent)	Sigma-Aldrich	74385	Nucleus Lysis buffer
Nuclease free water (not DEPC-treated)	Invitrogen	AM9937	Nucleus Lysis buffer
Protector RNase Inhibitor, 40 U/µL	Sigma-Aldrich	3335399001	Nucleus Lysis buffer
Sodium Chloride Solution, 5 M	Sigma-Aldrich	59222C	Nucleus Lysis buffer
Trizma Hydrochloride Solution, 1 M, pH 7.4	Sigma-Aldrich	T2194	Nucleus Lysis buffer
Bovine Serum Albumin 10%	Sigma-Aldrich	A1595-50ML	Nucleus wash
DPBS (Ca2+, Mg2+free)	Gibco	14190-169	Nucleus wash
Protector RNase Inhibitor,40 U/µL	Sigma-Aldrich	3335399001	Nucleus wash
Bovine Serum Albumin 10%	Sigma-Aldrich	A1595-50ML	ST staining buffer (ST-SB)
Calcium chloride solution, 1 M	Sigma-Aldrich	21115-100ML	ST staining buffer (ST-SB)
Magnesium Chloride Solution, 1 M	Sigma-Aldrich	M1028	ST staining buffer (ST-SB)
Nuclease free water (not DEPC treated)	Invitrogen	AM9937	ST staining buffer (ST-SB)
Sodium Chloride Solution, 5M	Sigma-Aldrich	59222C	ST staining buffer (ST-SB)
Trizma Hydrochloride Solution, 1M, pH 7.4	Sigma-Aldrich	T2194	ST staining buffer (ST-SB)
Tween-20	Merck Millipore	822184	ST staining buffer (ST-SB)
TotalSeq-A0451 anti-Nuclear Pore Complex Proteins Hashtag 1 Antibody	Biolegend	682205	Hashtag antibody
TotalSeq-A0452 anti-Nuclear Pore Complex Proteins Hashtag 2 Antibody	Biolegend	682207	Hashtag antibody
TotalSeq-A0453 anti-Nuclear Pore Complex Proteins Hashtag 3 Antibody	Biolegend	682209	Hashtag antibody
TotalSeq-A0461 anti-Nuclear Pore Complex Proteins Hashtag 11 Antibody	Biolegend	682225	Hashtag antibody
TotalSeq-A0462 anti-Nuclear Pore Complex Proteins Hashtag 12 Antibody	Biolegend	682227	Hashtag antibody
TotalSeq-A0463 anti-Nuclear Pore Complex Proteins Hashtag 13 Antibody	Biolegend	682229	Hashtag antibody
TotalSeq-A0464 anti-Nuclear Pore Complex Proteins Hashtag 14 Antibody	Biolegend	682231	Hashtag antibody
TotalSeq-A0465 anti-Nuclear Pore Complex Proteins Hashtag 15 Antibody	Biolegend	682233	Hashtag antibody
TruStain FcX (human)	Biolegend	422302	FC receptor blocking solution
Equipment and consumables
Bright-Line Hemacytometer	Merck	Z359629-1EA
Centrifuge 5702/R A-4-38	Eppendorf	EP022629905
CoolCell LX Cell Freezing Container	Corning	CLS432003-1EA
Cryovial	Thermo Scientific	479-6840
DNA LoBind 0.5 mL Eppendorf tube	Eppendorf	EP0030108035-250EA
Eppendorf Safe-Lock Tubes 1.5 mL	Eppendorf	30121872
Falcon 35 mm Not TC-treated Petri dish	Corning	351008
Falcon 15 mL Conical Centrifuge Tubes	Fisher scientific	10773501
Forceps Dumont #5	Fine science tools	11252-40
Hardened Fine Scissors	Fine science tools	14091-09
Ice Pan, rectangular 4 L Orange	Corning	CLS432106-1EA
Leica MS5	Leica		Microscope
Moria MC50 Scissors	Fine science tools	15370-50
Noyes Spring Scissors	Fine science tools	15012-12
Olympus CK2 ULWCD	Olympus		Microscope
P10	Gilson	F144802
P1000	Gilson	F123602
P200	Gilson	F123601
Preseparation Filters (30 µm)	Miltenyi biotec	Miltenyi biotec130-041-407
Shaking water bath	GFL	1083
Silicon plate	RubberBV	3530	Dissection board
Software and packages
Cell ranger	V4.0.0
R programming	V4.1.1
R sudio	V1.3.1073
Seurat	V4.0
tydiverse	V1.3.1
Animals
B6.Cg-Tg(Wnt1-cre)2Sor/J mouse	The Jackson Laboratory	JAX stock #022501
B6.129(Cg)-Gt(ROSA)26Sortm4(ACTB-tdTomato,-EGFP)Luo/J mouse	The Jackson Laboratory	JAX stock #007576
C57BL/6J mice	Charles River
Code for the data analysis
https://github.com/rubenmethorst/Single-cell-SCG_JoVE