The authors have no acknowledgements.

All experimental procedures were approved by the Tokyo Metropolitan University Institutional Animal Care and Use Committee (IACUC). The animals were housed and handled in accordance with the Guide for the Care and Use of Laboratory Animals and the Guide for the Care and Use of Experimental Animals of the Canadian Council on Animal Care. We used animals bred and maintained at the Functional Morphology Laboratory, Department of Frontier Health Sciences, Tokyo Metropolitan University, Japan.
1. Animal Care and Housing
<ol>
	<li>Obtain 7 S. murinus (3 females and 4 males weighing 70-90 g) from a closed breeding colony.</li>
	<li>Cage the S. murinus individually after weaning (20 d after birth) in plastic cages equipped with a wooden nest box containing paper strips. Keep them in a conventionally conditioned animal room: 23-27 &#176;C, no humidity control, and a 12:12 h light:dark cycle. Supply commercial trout pellets and water ad libitum.</li>
</ol>
2. Tissue Preparation
<ol>
	<li>To prepare 4% (w/v) paraformaldehyde (PFA), dissolve 40 g of PFA in 1,000 mL of 0.01 M Phosphate-Buffered Saline (PBS, pH 7.4). In a fume cupboard, mix using a vortex until the solution is clear. Store the 4% PFA O/N at 4 &#176;C. 
	Caution: Wear appropriate Personal Protective Equipment (PPE) when handling PFA.</li>
	<li>To perfuse and fix the animal, anesthetize it with ether and then give it an intraperitoneal injection of somnopentyl (pentobarbital sodium, 0.6 mL/kg bodyweight).</li>
	<li>After the animal is completely narcotized, open the abdominal cavity with a scalpel, creating a midline abdominal incision 3 cm long. While incising the inferior vena cava for exsanguinating, insert a catheter retrogradely into the abdominal aorta at the level immediately above the bifurcation of this artery into the common iliac arteries.</li>
	<li>Inject somnopentyl (pentobarbital sodium, 1.0 mL/kg bodyweight). After complete euthanasia, perfuse with 0.01 M PBS (pH 7.4) and then with 4% PFA in a fume cupboard.</li>
	<li>After perfusion, inject 2-3 mL of white neoprene latex (dilute white neoprene latex 3:2 with Distilled Water (DW)) to label the blood vessels.</li>
	<li>Extract the abdominal organs, including the liver, gallbladder, common bile duct, duodenum, and pancreas en bloc, with the related nerves and vessels.</li>
	<li>Inject approximately 0.1 mL of blue neoprene latex (add a drop of blue ink to 10 mL of the diluted white neoprene latex) to the gallbladder to label the biliary system.</li>
	<li>Post-fix overnight with 4% PFA at 4 &#176;C for whole-mount immunostaining. 
	Caution: PFA is toxic. Avoid handling PFA directly. PFA should be used in a fume cupboard.</li>
</ol>
3. Whole-mount Immunohistochemistry
Note: Throughout the protocol, including during washing, antibody incubation, and coloration, the specimen must remain on the nutator, gently rocking at RT&#160;or at 4&#176;C.
<ol>
	<li>Day 1: Enzymatic treatment and inactivation of potential endogenous peroxidase
	<ol>
		<li>Wash the prepared specimen with DW 4x for 1 h each at RT in an appropriately sized glass vial. Rock the specimen gently on the nutator to remove the PFA. Avoid damaging the specimen when exchanging solutions.</li>
		<li>To prepare 1% (w/v) orthoperiodic acid, dissolve 1 g of orthoperiodic acid in 100 mL of DW.</li>
		<li>Incubate the specimen in 1% orthoperiodic acid for 20 min at RT to prevent any intrinsic peroxidase reaction.</li>
		<li>Prepare 0.004% (w/v) papain by dissolving 0.004 g of papain in 100 mL of 0.025 mol/L Tris-HCl buffer (pH 7.6).</li>
		<li>Wash the specimen with DW for 10 min at RT.</li>
		<li>Incubate the specimen in freshly prepared 0.004% papain for 2 h at 37 &#176;C in a constant-temperature bath with gentle rocking.</li>
		<li>Wash the specimen with DW for 50-60 min at RT.</li>
		<li>Store the specimen in 4% PFA at 4 &#176;C O/N.</li>
	</ol>
	</li>
	<li>Day 2: Enzymatic treatment
	<ol>
		<li>Wash the stored specimen with DW 4 times for 1 h each at RT.</li>
		<li>Incubate the specimen in freshly prepared 0.004% papain for 2 h at 37 &#176;C in a constant-temperature bath with gentle rocking.</li>
		<li>Wash the specimen with DW for 50-60 min at RT. Store the specimen in 4% PFA at 4 &#176;C O/N.</li>
	</ol>
	</li>
	<li>Day 3: Freezing treatment
	<ol>
		<li>Wash the stored specimen with DW 4x for 1 h each at RT, as above.</li>
		<li>Prepare 2.5% (w/v), 5% (w/v), and 10% (w/v) sucrose by dissolving 2.5 g, 5 g, and 10 g of sucrose, respectively, in 100 mL of 0.01 M PBS (pH 7.4).</li>
		<li>Immerse the specimen in 2.5% (w/v), 5% (w/v), and 10% (w/v) sucrose for 30 min each.</li>
		<li>Freeze the specimen at -20 &#176;C for 30 - 60 min and then completely thaw it at RT; repeat the cycle 3x.</li>
		<li>To prepare 2% Triton X-100 (v/v), add 2 mL of Triton X-100 to 100 mL of 0.01 M PBS (pH 7.4).</li>
		<li>Store the specimen in 2% Triton X-100 at 4 &#176;C O/N.</li>
	</ol>
	</li>
	<li>Day 4: Primary antibody incubation
	<ol>
		<li>Prepare the dilution solution of the primary antibody by dissolving 0.2 g of Bovine Serum Albumin (BSA), 0.3 mL of Triton X-100, and 0.1 g of sodium azide in 100 mL of 0.01 M PBS (pH 7.4). 
		Caution: Sodium azide is acutely toxic. Inhalation and touching must be avoided. Wear appropriate PPE.</li>
		<li>Dilute the primary antibody (NFP) 1:600 in the above dilution buffer (step 3.4.1). Incubate the specimen with NFP antibody at 4 &#176;C for 3-6 days, keeping the specimen gently rocking on the nutator. Larger specimens will require increased incubation times.</li>
	</ol>
	</li>
	<li>Secondary antibody incubation
	<ol>
		<li>Wash the specimen in PBS 4x for 1 h each at RT to remove unbound primary antibody.</li>
		<li>Prepare the dilution solution for the secondary antibody by dissolving 0.2 g of BSA and 0.3 mL of Triton X-100 in 100 mL of 0.01 M PBS (pH 7.4).</li>
		<li>Dilute the secondary antibody (peroxidase-conjugated, affinity-purified sheep anti-mouse IgG-HRP) 1:600 in the dilution buffer (step 3.5.2). Incubate the specimen with the secondary antibody at 4 &#176;C for 3 d, and keep the specimen rocking gently on the nutator.</li>
	</ol>
	</li>
	<li>Coloration
	<ol>
		<li>Prepare DAB coloration solution by adding 0.002 g of 3,3&#39;-diaminobenzidine tetrahydrochloride (DAB) to 100 mL of 0.05 mol/L Tris-HCl buffer (pH 7.6) under a fume cupboard, keeping the solution in the dark.</li>
		<li>Wash the specimens at RT in PBS 4x for 1 h each.</li>
		<li>Add 10 &#181;L of 30% H2O2 in freshly prepared DAB coloration solution and incubate with the solution at 4 &#176;C O/N or for 3 d while rocking gently on the nutator.</li>
		<li>Stop the reaction by placing the specimen in PBS with 0.04% sodium azide when the optimal staining intensity is reached. 
		NOTE: Avoid the use of sodium azide until this step, as it inhibits horseradish peroxidase.</li>
	</ol>
	</li>
	<li>Imaging the stained tissue
	<ol>
		<li>Carefully transfer the specimen to a petri glass dish (5 cm high, 10 cm in diameter) containing PBS. Capture whole-mount images using a camera mounted on a stereomicroscope. 
		NOTE: Whole-mount stained tissue should be imaged while immersed completely in PBS on a transparent glass dish.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Kuratani, S., Tanaka, S., Ishikawa, Y., Zukeran, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+development+of+the+hypoglossal+nerve+in+the+chick+embryo+as+observed+by+the+whole-mount+nerve+staining+method.">Early development of the hypoglossal nerve in the chick embryo as observed by the whole-mount nerve staining method.</a> Am. J. Anat. 182 (2), 155-168 (1988).</li><li>Kuratani, S., Tanaka, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+development+of+the+avian+vagus+nerve+with+special+reference+to+the+morphological+innervation+of+heart+and+lung.">Peripheral development of the avian vagus nerve with special reference to the morphological innervation of heart and lung.</a> Anat. Embryol. (Berl). 182 (5), 435-445 (1990).</li><li>Kuratani, S., Tanaka, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+development+of+avian+trigeminal+nerves.">Peripheral development of avian trigeminal nerves.</a> Am. J. Anat. 187 (1), 65-80 (1990).</li><li>Yi, S. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=House+musk+shrew,+Suncus+murinus:+a+novel+and+natural+obesity-resistant+animal+model.">House musk shrew, Suncus murinus: a novel and natural obesity-resistant animal model.</a> Obes. Metab. 6, 22-28 (2010).</li><li>Yi, S. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+anatomy+of+innervation+of+the+gallbladder+in+humans+and+Suncus+murinus+with+special+reference+to+morphological+understanding+of+gallstone+formation+after+gastrectomy.">Surgical anatomy of innervation of the gallbladder in humans and Suncus murinus with special reference to morphological understanding of gallstone formation after gastrectomy.</a> World J. Gastroenterol. 13 (14), 2066-2071 (2007).</li><li>Yi, S. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomical+study+of+the+pancreas+in+the+house+musk+shrew,+Suncus+murinus,+with+special+reference+to+the+blood+supply+and+innervation.">Anatomical study of the pancreas in the house musk shrew, Suncus murinus, with special reference to the blood supply and innervation.</a> Anat. Rec. A Discov. Mol. Cell Evol. Biol. 273 (1), 630-635 (2003).</li><li>Yi, S. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+anatomy+of+the+innervation+of+the+major+duodenal+papilla+in+humans+and+Suncus+murinus,+from+the+perspective+of+preserving+innervation+in+organ-saving+procedures.">Surgical anatomy of the innervation of the major duodenal papilla in humans and Suncus murinus, from the perspective of preserving innervation in organ-saving procedures.</a> Pancreas. 30 (3), 211-217 (2005).</li><li>Yi, S. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+anatomy+of+the+innervation+of+the+pylorus+in+humans+and+Suncus+murinus,+in+relation+to+the+surgical+technique+for+pylorus-preserving+pancreatoduodenectomy.">Surgical anatomy of the innervation of the pylorus in humans and Suncus murinus, in relation to the surgical technique for pylorus-preserving pancreatoduodenectomy.</a> World J. Gastroenterol. 12 (14), 2209-2216 (2006).</li><li>Yi, S. Q., Ren, K., Kinoshita, M., Takano, N., Itoh, M., Ozaki, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Innervation+of+Extrahepatic+Biliary+Tract,+With+Special+Reference+to+the+Direct+Bidirectional+Neural+Connections+of+the+Gall+Bladder,+Sphincter+of+Oddi+and+Duodenum+in+Suncus+murinus,+in+Whole-Mount+Immunohistochemical+Study.">Innervation of Extrahepatic Biliary Tract, With Special Reference to the Direct Bidirectional Neural Connections of the Gall Bladder, Sphincter of Oddi and Duodenum in Suncus murinus, in Whole-Mount Immunohistochemical Study.</a> Anat. Histol. Embryol. 45 (3), 184-188 (2016).</li><li>Wang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurofilament+proteins+in+axonal+regeneration+and+neurodegenerative+diseases.">Neurofilament proteins in axonal regeneration and neurodegenerative diseases.</a> Neural Regen. Res. 7 (8), 620-626 (2012).</li><li>Wyatt, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relationship+of+the+sphincter+of+Oddi+to+the+stomach,+duodenum+and+gall-bladder.">The relationship of the sphincter of Oddi to the stomach, duodenum and gall-bladder.</a> J. Physiol. 193 (2), 225-243 (1967).</li><li>Mawe, G. M., Kennedy, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Duodenal+neurons+provide+nicotinic+fast+synaptic+input+to+sphincter+of+Oddi+neurons+in+guinea+pig.">Duodenal neurons provide nicotinic fast synaptic input to sphincter of Oddi neurons in guinea pig.</a> Am. J. Physiol. 277, G226-G234 (1999).</li><li>Seo, J. H., Cho, S. S., Lee, I. S., Lee, H. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomical+and+neuropeptidergic+properties+of+the+duodenal+neurons+projecting+to+the+gallbladder+in+the+golden+hamster.">Anatomical and neuropeptidergic properties of the duodenal neurons projecting to the gallbladder in the golden hamster.</a> Arch. Histol. Cytol. 65 (4), 317-321 (2002).</li><li>Padbury, R. T., Furness, J. B., Baker, R. A., Toouli, J., Messenger, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Projections+of+nerve+cells+from+the+duodenum+to+the+sphincter+of+Oddi+and+gallbladder+of+the+Australian+possum.">Projections of nerve cells from the duodenum to the sphincter of Oddi and gallbladder of the Australian possum.</a> Gastroenterology. 104 (1), 130-136 (1993).</li><li>White, J. J., Reeber, S. L., Hawkes, R., Sillitoe, R. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wholemount+immunohistochemistry+for+revealing+complex+brain+topography.">Wholemount immunohistochemistry for revealing complex brain topography.</a> J. Vis. Exp. (62), e4042 (2012).</li></ol>

The authors declare no conflicts of interest.

This work describes the experimental procedure for the visualization of the innervation of the extrahepatic biliary tract using an antibody against neurofilament protein. This protocol was adapted from the protocol described by Kuratani and Tanaka1,2,3.
For this experiment, plan the timeline for each of the experiments, as the whole-mount staining approach continues for 2-3 weeks. The vessel containin...

The house musk shrew, Suncus murinus, belongs to the order Insectivora and the family Soricidae. This tiny mammal is distributed throughout Southeast Asia and inhabits houses and grassy areas that are situated near human habitations or cattle pens4. This species exhibits general morphological characteristics more similar to humans than other laboratory animals, such as the mouse, rat, and rabbit5. Previously, whole-mount immunostaining with a peripheral neuron marker for S. murinus neurofilament protein (NFP) was used to label peripheral nerves in the pancreas6, major duodenal papilla7, pylorus8, gallbladder5, and extrahepatic biliary tract9.
NFP is a macromolecular complex that is part of the mature neuronal cytoskeleton. Neurofilament-related proteins mediate interactions between NFP and the zygosome. Both enzyme function and the structure of linker proteins are regulated by NFP10. The NFP complex is made of three polypeptides: NF-L (70 kDa), NF-M (150-160 kDa), and NF-H (200 kDa). NFP can be found in neuronal axons in both the central and peripheral nervous system. Anti-human NFP antibody has been shown to label axons of the central and peripheral nervous system. Anatomical and electrophysiological investigations have demonstrated that the sphincter, gallbladder, and proximal gastrointestinal tract are connected11,12,13,14. However, the morphological features of their neuronal connections have not yet been defined.
This work demonstrates the use of a whole-mount immunohistochemical staining method to label the innervation of the S. murinus biliary tract with an NFP antibody.

<table><tbody><tr><td>orthoperiodic acid</td><td>Wako</td><td>162-00732</td><td></td></tr><tr><td>papain</td><td>Wako</td><td>164-00172</td><td></td></tr><tr><td>bovine serum albumin (BSA)</td><td>Wako</td><td>010-15131</td><td></td></tr><tr><td>sodium azide</td><td>Nacalai Tesque</td><td>312-33</td><td></td></tr><tr><td>neurofilament protein (NFP) antibody</td><td>Dako</td><td>M0762, lot 089, clone: 2F11</td><td></td></tr><tr><td>peroxidase-conjugated affinity-purified sheep anti-mouse IgG-HRP</td><td>MBL</td><td>Code 330</td><td></td></tr><tr><td>3,3&#039;-diaminobenzidine tetrahydrochloride (DAB)</td><td>Wako</td><td>349-00903</td><td></td></tr><tr><td>imidazole</td><td>Sigma</td><td>I-0125</td><td></td></tr></tbody></table>

using a whole-mount immunohistochemical method to study the innervation of the biliary tract in suncus murinus

This work describes the whole-mount immunohistochemistry staining method in detail, using neurofilament protein antibody to label the innervation of the biliary tract in Suncus murinus (S. murinus&#160;). First, the specimen was dissected from S. murinus and fixed in 4% paraformaldehyde (PFA). Second, an enzymatic treatment and potential endogenous peroxidase inactivation were performed. The specimen was then exposed to the primary antibody, anti-neurofilament protein antibody, for 3-6 days. It was then incubated with the secondary antibody conjugated with horseradish peroxidase. The color reaction was revealed by reacting the specimen with a 3,3&#39;-diaminobenzidine (DAB) substrate. This method can be applied to analyze the innervation of all visceral organs. Furthermore, this protocol can also be adapted to test other neuronal antibodies, but optimization of the antibodies should be done first. This method was originally introduced by Kuratani and Tanaka1,2,3.

Figures 1-4 show typical results for NFP-positive nerve fibers in the extrahepatic biliary tract in S. murinus. The antibody against NFP reproducibly labeled the innervation in the entire image of the extrahepatic biliary tract (Figure 1), gallbladder (Figure 2), upper bile duct (Figure 3), and duodenal papilla area (Figure 4), ...

Watch this Scientific Journal Video about Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus at JoVE.com

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

A whole-mount immunohistochemical approach, to visualize neurofilament protein expression in the extrahepatic biliary tract in Suncus murinus. is presented here. This protocol can be used to analyze the innervation of all visceral organs in S. murinus or other species.

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

This work describes the whole-mount immunohistochemistry staining method in detail, using neurofilament protein antibody to label the innervation of the ...

using-whole-mount-immunohistochemical-method-to-study-innervation

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

6.7K Views.  Tokyo Metropolitan University. A whole-mount immunohistochemical approach, to visualize neurofilament protein expression in the extrahepatic biliary tract in Suncus murinus. is presented here. This protocol can be used to analyze the innervation of all visceral organs in S. murinus or other species.

Video: Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

Immunostaining to Visualize Murine Enteric Nervous System Development

The enteric nervous system is formed by neural crest cells that proliferate, migrate and colonize the gut. Following colonization, neural crest cells must then differentiate into neurons with markers specific for their neurotransmitter phenotype. Cholinergic neurons, a major neurotransmitter phenotype in the enteric nervous system, are identified by staining for choline acetyltransferase (ChAT), the synthesizing enzyme for acetylcholine. Historical efforts to visualize cholinergic neurons have been hampered by antibodies with differing specificities to central nervous system versus peripheral nervous system ChAT. We and others have overcome this limitation by using an antibody against placental ChAT, which recognizes both central and peripheral ChAT, to successfully visualize embryonic enteric cholinergic neurons. Additionally, we have compared this antibody to genetic reporters for ChAT and shown that the antibody is more reliable during embryogenesis. This protocol describes a technique for dissecting, fixing and immunostaining of the murine embryonic gastrointestinal tract to visualize enteric nervous system neurotransmitter expression.

The enteric nervous system is formed by neural crest cells that proliferate, migrate and colonize the gut. Neural crest cells differentiate into neurons with markers specific for their neurotransmitter phenotype. This protocol describes a technique for dissecting, fixing and immunostaining of the murine embryonic gastrointestinal tract to visualize enteric nervous system neurotransmitter expression.

The enteric nervous system is formed by neural crest cells that proliferate, migrate and colonize the gut. Following colonization, neural crest cells must ...

Developmental Biology

In Vivo Immunofluorescence Localization for Assessment of Therapeutic and Diagnostic Antibody Biodistribution in Cancer Research

Monoclonal antibodies (mAbs) are important tools in cancer detection, diagnosis, and treatment. They are used to unravel the role of proteins in tumorigenesis, can be directed to cancer biomarkers enabling tumor detection and characterization, and can be used for cancer therapy as mAbs or antibody-drug conjugates to activate immune effector cells, to inhibit signaling pathways, or directly kill cells carrying the specific antigen. Despite clinical advancements in the development and production of novel and highly specific mAbs, diagnostic and therapeutic applications can be impaired by the complexity and heterogeneity of the tumor microenvironment. Thus, for the development of efficient antibody-based therapies and diagnostics, it is crucial to assess the biodistribution and interaction of the antibody-based conjugate with the living tumor microenvironment. Here, we describe In Vivo Immunofluorescence Localization (IVIL) as a new approach to study interactions of antibody-based therapeutics and diagnostics in the in vivo physiological and pathological conditions. In this technique, a therapeutic or diagnostic antigen-specific antibody is intravenously injected in&#160;vivo and localized ex vivo with a secondary antibody in isolated tumors. IVIL, therefore, reflects the in vivo biodistribution of antibody-based drugs and targeting agents. Two IVIL applications are described assessing the biodistribution and accessibility of antibody-based contrast agents for molecular imaging of breast cancer. This protocol will allow future users to adapt the IVIL method for their own antibody-based research applications.

The in vivo immunofluorescence localization (IVIL) method can be used to examine in vivo biodistribution of antibodies and antibody conjugates for oncological purposes in living organisms using a combination of in vivo tumor targeting and ex vivo immunostaining methods.

Monoclonal antibodies (mAbs) are important tools in cancer detection, diagnosis, and treatment. They are used to unravel the role of proteins in ...

Cancer Research

Determining Bile Duct Density in the Mouse Liver

Mouse is broadly used as a model organism to study biliary diseases. To evaluate the development and function of the biliary system, various techniques are used, including serum chemistry, histological analysis, and immunostaining for specific markers. Although these techniques can provide important information about the biliary system, they often do not present a full picture of bile duct (BD) developmental defects across the whole liver. This is in part due to the robust ability of the mouse liver to drain the bile even in animals with significant impairment in biliary development. Here we present a simple method to calculate the average number of BDs associated with each portal vein (PV) in sections covering all lobes of mutant/transgenic mice. In this method, livers are mounted and sectioned in a stereotypic manner to facilitate comparison among various genotypes and experimental conditions. BDs are identified via light microscopy of cytokeratin-stained cholangiocytes, and then counted and divided by the total number of PVs present in liver section. As an example, we show how this method can clearly distinguish between wild-type mice and a mouse model of Alagille syndrome. The method presented here cannot substitute for techniques that visualize the three-dimensional structure of the biliary tree. However, it offers an easy and direct way to quantitatively assess BD development and the degree of ductular reaction formation in mice.

We present a rather simple and sensitive method for accurate quantification of bile duct density in the mouse liver. This method can aid in determining the effects of genetic and environmental modifiers and the effectiveness of potential therapies in mouse models of biliary diseases.

Mouse is broadly used as a model organism to study biliary diseases. To evaluate the development and function of the biliary system, various techniques ...

Bile Duct Ligation in Mice: Induction of Inflammatory Liver Injury and Fibrosis by Obstructive Cholestasis

In most vertebrates, the liver produces bile that is necessary to emulsify absorbed fats and enable the digestion of lipids in the small intestine as well as to excrete bilirubin and other metabolic products. In the liver, the experimental obstruction of the extrahepatic biliary system initiates a complex cascade of pathological events that leads to cholestasis and inflammation resulting in a strong fibrotic reaction originating from the periportal fields. Therefore, surgical ligation of the common bile duct has become the most commonly used model to induce obstructive cholestatic injury in rodents and to study the molecular and cellular events that underlie these pathophysiological mechanisms induced by inappropriate bile flow. In recent years, different surgical techniques have been described that either allow reconnection or reanastomosis after bile duct ligation (BDL), e.g., partial BDL, or other microsurgical methods for specific research questions. However, the most frequently used model is the complete obstruction of the common bile duct that induces a strong fibrotic response after 21 to 28 days. The mortality rate can be high due to infectious complications or technical inaccuracies. Here we provide a detailed surgical procedure for the BDL model in mice that induce a highly reproducible fibrotic response in accordance to the 3R rule for animal welfare postulated by Russel and Burch in 1959.

Disruption of bile flow results in severe inflammatory cholestatic liver injury with a characteristic time-dependent sequence of morphological alterations. Here we present a protocol for the surgical ligation of the common bile duct in mice that allows to induce a strong fibrotic response after 21 to 28 days.

In most vertebrates, the liver produces bile that is necessary to emulsify absorbed fats and enable the digestion of lipids in the small intestine as well ...

Medicine

In Situ Ca2+ Imaging of the Enteric Nervous System

Reflex behaviors of the intestine are controlled by the enteric nervous system (ENS). The ENS is an integrative network of neurons and glia in two ganglionated plexuses housed in the gut wall. Enteric neurons and enteric glia are the only cell types within the enteric ganglia. The activity of enteric neurons and glia is responsible for coordinating intestinal functions. This protocol describes methods for observing the activity of neurons and glia within the intact ENS by imaging intracellular calcium (Ca2+) transients with fluorescent indicator dyes. Our technical discussion focuses on methods for Ca2+ imaging in whole-mount preparations of the myenteric plexus from the rodent bowel. Bulk loading of ENS whole-mounts with a high-affinity Ca2+ indicator such as Fluo-4 permits measurements of Ca2+ responses in individual neurons or glial cells. These responses can be evoked repeatedly and reliably, which permits quantitative studies using pharmacological tools. Ca2+ responses in cells of the ENS are recorded using a fluorescence microscope equipped with a cooled charge-coupled device (CCD) camera. Fluorescence measurements obtained using Ca2+ imaging in whole-mount preparations offer a straightforward means of characterizing the mechanisms and potential functional consequences of Ca2+ responses in enteric neurons and glial cells.

In Situ Ca2+ Imaging of the Enteric Nervous System

The enteric nervous system (ENS) is a network of neurons and glia located in the gut wall that controls intestinal reflexes. This protocol describes methods for recording the activity of enteric neurons and glia in live preparations of ENS using Ca2+ imaging.

Reflex behaviors of the intestine are controlled by the enteric nervous system (ENS). The ENS is an integrative network of neurons and glia in two ...

Neuroscience

Visualization of the Interstitial Cells of Cajal (ICC) Network in Mice

The interstitial cells of Cajal (ICC) are mesenchymal derived "pacemaker cells" of the gastrointestinal (GI) tract that generate spontaneous slow waves required for peristalsis and mediate neuronal input from the enteric nervous system1. Different subtypes of ICC form distinct networks in the muscularis of the GI tract 2,3. Loss or injury to these networks is associated with a number of motility disorders4. ICC cells express the KIT receptor tyrosine kinase on the plasma membrane and KIT immunostaining has been used for the past 15 years to label the ICC network5,6. Importantly, normal KIT activity is required for ICC development5,6. Neoplastic transformation of ICC cells results in gastrointestinal stromal tumor (GIST), that frequently harbor gain-of-function KIT mutations7,8. We recently showed that ETV1 is a lineage-specific survival factor expressed in the ICC/GIST lineage and is a master transcriptional regulator required for both normal ICC network formation and for of GIST tumorigenesis9. We further demonstrate that it cooperates with activating KIT mutations in tumorigenesis. Here, we describe methods for visualization of ICC networks in mice, largely based on previously published protocols10,11. More recently, the chloride channel anoctamin 1 (ANO1) has also been characterized as a specific membrane marker of ICC11,12. Because of their plasma membrane localization, immunofluorescence of both proteins can be used to visualize the ICC networks. Here, we describe visualization of the ICC networks by fixed-frozen cyrosections and whole mount preparations.

Visualization of the Interstitial Cells of Cajal ICC Network in Mice

The interstitial cells of Cajal (ICC) are the pacemaker cells of the gastrointestinal (GI) tract. They form complex networks between smooth muscle cells and post-ganglionic neuronal fibers to regulate GI contractility. Here, we present immunofluorescence methods cross-sectional and whole-mount visualization of murine ICC networks.

The interstitial cells of Cajal (ICC) are mesenchymal derived "pacemaker cells" of the gastrointestinal (GI) tract that generate spontaneous slow waves ...

Intravital Imaging of Intraepithelial Lymphocytes in Murine Small Intestine

Intraepithelial lymphocytes expressing &#947;&#948; T cell receptor (&#947;&#948; IEL) play a key role in immune surveillance of the intestinal epithelium. Due in part to the lack of a definitive ligand for the &#947;&#948; T cell receptor, our understanding of the regulation of &#947;&#948; IEL activation and their function in vivo remains limited. This necessitates the development of alternative strategies to interrogate signaling pathways involved in regulating &#947;&#948; IEL function and the responsiveness of these cells to the local microenvironment. Although &#947;&#948; IELs are widely understood to limit pathogen translocation, the use of intravital imaging has been critical to understanding the spatiotemporal dynamics of IEL/epithelial interactions at steady-state and in response to invasive pathogens. Herein, we present a protocol for visualizing IEL migratory behavior in the small intestinal mucosa of a GFP &#947;&#948; T cell reporter mouse using inverted spinning disk confocal laser microscopy. Although the maximum imaging depth of this approach is limited relative to the use of two-photon laser-scanning microscopy, spinning disk confocal laser microscopy provides the advantage of high speed image acquisition with reduced photobleaching and photodamage. Using 4D image analysis software, T cell surveillance behavior and their interactions with neighboring cells can be analyzed following experimental manipulation to provide additional insight into IEL activation and function within the intestinal mucosa.

We describe a method to visualize GFP-labeled &#947;&#948; IELs using intravital imaging of murine small intestine by inverted spinning disk confocal microscopy. This technique enables the tracking of live cells within the mucosa for up to 4 h and can be used to investigate a variety of intestinal immune-epithelial interactions. &#160;

Intraepithelial lymphocytes expressing &#947;&#948; T cell receptor (&#947;&#948; IEL) play a key role in immune surveillance of the intestinal ...

Immunology and Infection

A New Clarification Method to Visualize Biliary Degeneration During Liver Metamorphosis in Sea Lamprey (Petromyzon marinus)

Biliary atresia is a rare disease of infancy, with an estimated 1 in 15,000 frequency in the southeast United States, but more common in East Asian countries, with a reported frequency of 1 in 5,000 in Taiwan. Although much is known about the management of biliary atresia, its pathogenesis is still elusive. The sea lamprey (Petromyzon marinus) provides a unique opportunity to examine the mechanism and progression of biliary degeneration. Sea lamprey develop through three distinct life stages: larval, parasitic, and adult. During the transition from larvae to parasitic juvenile, sea lamprey undergo metamorphosis with dramatic reorganization and remodeling in external morphology and internal organs. In the liver, the entire biliary system is lost, including the gall bladder and the biliary tree. A newly-developed method called &#8220;CLARITY&#8221; was modified to clarify the entire liver and the junction with the intestine in metamorphic sea lamprey. The process of biliary degeneration was visualized and discerned during sea lamprey metamorphosis by using laser scanning confocal microscopy. This method provides a powerful tool to study biliary atresia in a unique animal model.

A New Clarification Method to Visualize Biliary Degeneration During Liver Metamorphosis in Sea Lamprey Petromyzon marinus

Sea lamprey lose the gall bladder and bile ducts during metamorphosis, a process similar to human biliary atresia. A new fixation and clarification method (CLARITY) was modified to visualize the entire biliary tree using laser scanning confocal microscopy. This method provides a powerful tool to study biliary degeneration.

Biliary atresia is a rare disease of infancy, with an estimated 1 in 15,000 frequency in the southeast United States, but more common in East Asian ...

Murine Precision-Cut Liver Slices as an Ex Vivo Model of Liver Biology

Understanding the mechanisms of liver injury, hepatic fibrosis, and cirrhosis that underlie chronic liver diseases (i.e., viral hepatitis, non-alcoholic fatty liver disease, metabolic liver disease, and liver cancer) requires experimental manipulation of animal models and in vitro cell cultures. Both techniques have limitations, such as the requirement of large numbers of animals for in vivo manipulation. However, in vitro cell cultures do not reproduce the structure and function of the multicellular hepatic environment. The use of precision-cut liver slices is a technique in which uniform slices of viable mouse liver are maintained in laboratory tissue culture for experimental manipulation. This technique occupies an experimental niche that exists between animal studies and in vitro cell culture methods. The presented protocol describes a straightforward and reliable method to isolate and culture precision-cut liver slices from mice. As an application of this technique, ex vivo liver slices are treated with bile acids to simulate cholestatic liver injury and ultimately assess the mechanisms of hepatic fibrogenesis.

This protocol provides a simple and reliable method for the production of viable precision-cut liver slices from mice. The ex vivo tissue samples can be maintained under laboratory tissue culture conditions for multiple days, providing a flexible model to examine liver pathobiology.

Understanding the mechanisms of liver injury, hepatic fibrosis, and cirrhosis that underlie chronic liver diseases (i.e., viral hepatitis, non-alcoholic ...

Location, Dissection, and Analysis of the Murine Stellate Ganglion

The autonomic nervous system is a substantial driver of cardiac electrophysiology. Especially&#160;the role of its sympathetic branch is an ongoing matter of investigation in the pathophysiology of ventricular arrhythmias (VA). Neurons in the stellate ganglia (SG)&#160;&#8211;&#160;bilateral star-shaped structures of the sympathetic chain &#8211;&#160;are an important component of the sympathetic infrastructure. The SG are a recognized target for&#160;treatment via cardiac sympathetic denervation in patients with therapy-refractory VA. While neuronal remodeling and glial activation in the SG have been described in patients with VA, the underlying cellular and molecular processes that potentially precede the onset of arrhythmia are only insufficiently understood and should be elucidated to improve autonomic modulation. Mouse models allow us to study sympathetic neuronal remodeling, but identification of the murine SG is challenging for the inexperienced investigator. Thus, in-depth cellular and molecular biological studies of the murine SG are lacking for many common cardiac diseases. Here, we describe a basic repertoire for dissecting and studying the SG in adult mice for analyses at RNA level (RNA isolation for gene expression analyses, in situ hybridization), protein level (immunofluorescent whole mount staining), and cellular level (basic morphology, cell size measurement). We present potential solutions to overcome challenges in the preparation technique, and how to improve staining via quenching of autofluorescence. This allows for the visualization of neurons as well as glial cells via established markers in order to determine cell composition and remodeling processes. The methods presented here allow characterizing the SG to gain further information on autonomic dysfunction in mice prone to VA and can be complemented by additional techniques investigating neuronal and glial components of the autonomic nervous system in the heart.

Pathophysiological changes in the cardiac autonomic nervous system, especially in its sympathetic branch, contribute to the onset and maintenance of ventricular arrhythmias. In the present protocol, we show how to characterize murine stellate ganglia to improve the understanding of the underlying molecular and cellular processes.

The autonomic nervous system is a substantial driver of cardiac electrophysiology. Especially&#160;the role of its sympathetic branch is an ongoing matter ...

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

Summary

Explore More Videos

Chapters in this video

Immunostaining to Visualize Murine Enteric Nervous System Development

In Vivo Immunofluorescence Localization for Assessment of Therapeutic and Diagnostic Antibody Biodistribution in Cancer Research

Determining Bile Duct Density in the Mouse Liver

Bile Duct Ligation in Mice: Induction of Inflammatory Liver Injury and Fibrosis by Obstructive Cholestasis

In Situ Ca²⁺ Imaging of the Enteric Nervous System

Visualization of the Interstitial Cells of Cajal (ICC) Network in Mice

Intravital Imaging of Intraepithelial Lymphocytes in Murine Small Intestine

A New Clarification Method to Visualize Biliary Degeneration During Liver Metamorphosis in Sea Lamprey (Petromyzon marinus)

Murine Precision-Cut Liver Slices as an Ex Vivo Model of Liver Biology

Location, Dissection, and Analysis of the Murine Stellate Ganglion