This work was supported by training grants by the Department of Obstetrics and Gynecology, Baylor College of Medicine (ALG) and R-01 research grant (Grant # DK114689) for CSB, SC and JM from National Institutes of Health.

All animal procedures were approved by the Institutional Animal Care and Use Committee (IACUC) of the Baylor College of Medicine.
1. Preparation of [6,6-2H2]glucose
<ol>
	<li>One day before the procedure, prepare the stable isotope glucose tracer in normal saline. For this experiment, [6,6-2H2]glucose was used as a tracer to measure plasma glucose appearance rate. 
	NOTE: In this experiment, glucose production during fasting and glucose-rich conditions were measured, so the glucose isotope was prepared in two different preparations. Prepare the solutions in such a way that the final infusing dose will be close to 1 mg/(kg&#183;min) and 2 mg/(kg&#183;min), respectively. These concentrations were optimized by several prior pilot studies.</li>
	<li>Prepare the first infusate with only [6,6-2H2]glucose as a tracer to represent the fasting condition by dissolving sterile and pyrogen free [6,6-2H2]glucose in sterile 0.9% sodium chloride solution.</li>
	<li>Prepare the second infusate by dissolving both [6,6-2H2]glucose tracer along with non-isotopic glucose (~20 mg/kg&#183;min) in sterile 0.9% sodium chloride solution to simulate the fed condition. 
	NOTE: In the present experiment, a primed constant rate infusion of [6,6-2H2]glucose at (~) 1.08 mg/(kg&#183;min) (fasting condition) and (~) 1.9 mg/kg&#183;min (glucose rich condition) was used. In order to mimic the &#39;glucose rich condition&#39;, D-glucose infusion rate was set at (~) 18.8 mg/(kg&#183;min).</li>
	<li>Once the solutions are prepared, sterile filter the solutions with a 0.22 &#181;m filter and store at 4 &#176;C. Warm the solutions to room temperature prior to the infusion. Load the solutions on prelabeled 1 mL syringes.</li>
	<li>Set up the pump to facilitate a primed constant rate infusion of the first infusate (for basal condition) containing only the tracer, and program the pump for a constant rate infusion of the isotope at 150 &#181;L/h for 3 h.</li>
	<li>At the end of the 3 h fasting set up, replace the first infusate syringe with the second infusate syringe containing the isotopic tracer and D-glucose (for the simulated fed state), and prime the infusion for the intial 15 min at 600 &#181;L/h. Set the pump to a constant rate infusion at 150 &#181;L/h for the additional 3 h.</li>
</ol>
2. Set-up of infusion experiments
<ol>
	<li>Remove the mice from their home cages and place them in their fasting cages 3 h prior to the start of the experiment. For this experiment, a 4-month-old female mice from the C57BL/6J strain was used. 
	NOTE: This procedure does not require any analgesia prior to or during the procedure given its minimally invasive nature.</li>
	<li>Assemble the caging equipment by grouping the mice into a set number of mice per insulin pump. Place partitions on top of a flat, stable base to make individual stalls for the mice. It is important to have access to the tail vein catheter for the infusion to run, so ensure that there is a notch in the bottom of the cage door. 
	NOTE: Cages shown in the video were made specifically for this experiment. Cages are clear and made out of plexiglass. There is a flat, stable base (standard caging equipment) upon which the partitions sit. This setup consists of several pieces to allow ease of setup in several different environments depending on the height of the table and the needs of the experimenter. The door to the cage slides to close and has a notch at the bottom to allow the tail to fit through.</li>
	<li>Assemble the 1&#160;mL syringes containing 1 mL of basal infusate, and then connect to the infusion pump tubing using the polyethylene tubing 0.28 mm ID x 0.61 mm.</li>
	<li>Prepare the infusion pump by setting the rate to 150 &#181;L/h, which is the basal rate.</li>
	<li>Heat a water bath to 48 &#176;C.</li>
	<li>Prepare the catheter insertion station adjacent to the water bath containing the 30 G 0.5 inch needles, 0.3 mm ID x 0.64 mm silastic tubing, and 1 inch clear transpore tape.</li>
	<li>After 3 h of fasting, begin the catheter insertion process, which is detailed below.</li>
</ol>
3. Catheter insertion
<ol>
	<li>Select one mouse and place it in a secure holder with access to the tail. An example of what to use is a bottle cut in half with a notch for the tail. Place the holder on a flat base. Place a piece tape over the proximal portion of the tail to allow space for catheter insertion more distally. 
	NOTE: The type of tape chosen for this task must have moderate strength and adhesiveness. Multipurpose, paper-based labeling tape was used in this experiment as it is mild and easy to peel off.</li>
	<li>Prepare the catheter (30 G needle attached to 0.3 mm silastic tubing and PE- 10 were gas sterilized) by attaching it to a 1 mL syringe containing sterile heparinized saline flush. Flush the catheter gently.</li>
	<li>Bring the mouse to the water bath and insert the tail in the water bath for approximately 30-45 s. This helps to dilate the tail vasculature for catheter placement.</li>
	<li>Perform the catheter insertion under sterile conditions. Once the tail is warmed, clean the tail with benzalkonium wipes and place a small copper, toothless alligator clamp, that was previously contoured to the shape of the tail, as a tourniquet at the proximal end of the tail. Visualize the lateral tail vein under a magnifying glass, and then carefully insert the catheter into the tail vein and withdraw the needle. Flush the solution gently to ensure patency of the catheter.</li>
	<li>Wrap a piece of 1 inch transpore tape around the insertion site to secure the catheter. Remove the small tourniquet from the tail.</li>
</ol>
4. Infusion set-up and first infusion
<ol>
	<li>Place the mouse in its individual cage and close the sliding door, ensuring the tail is protruding through the notch and remains outside of the cage.</li>
	<li>Place an additional piece of tape over the whole catheter and the tail to secure it to the base plate of the cage. Multipurpose colored, label tape was used for this step.</li>
	<li>Disconnect the flush from the tail vein catheter and place a small clamp on the catheter&#39;s silastic tubing to prevent backflow while connecting the infusate line from the pump.</li>
	<li>Once securely connected, remove the clamp and flush with the priming solution, which consists of the infusate. Ensure that the solution is clear in the tubing and not blood-stained.</li>
	<li>Make note of the time of initiation of the infusion to ensure that it runs for the total time of approximately 3 h. If multiple cages are used simultaneously, they should be staggered to manage infusion times effectively.</li>
	<li>Once infusion lines are noted to be functioning properly, remove the cover from the mouse. Place standard bedding around the mouse.</li>
	<li>Start the infusion with the first infusate containing the tracer and run it for 3 h continuously. For the duration of the infusion, continue to check mice wellbeing as well as infusion lines. Ensure that the infusion tubing is properly secured and that there are no leaks from the line connection points.</li>
</ol>
5. Blood sampling
<ol>
	<li>After the first infusion has completed, stop the infusion, place a clamp on the sylastic tubing on the catheter to prevent back flow. Gently remove the mice from their enclosures without disturbing the catheter in order to collect blood. Place them at a spot near the cages for blood draw. For this experiment, the mice underwent cheek venipuncture using a 4 mm lancet.</li>
	<li>Collect ~75 &#181;L of blood in the desired vial. To deproteinize samples in preparation for mass spectrometry, add approximately 15 &#181;L of blood to 500 &#181;L of acetone. The remaining blood can be used to check the blood glucose level via the glucometer and/or centrifuged to separate plasma for future hormone assays.</li>
</ol>
6. Second infusion
<ol>
	<li>Remove the infusates from the syringe pumps by disconnecting the tubing from the syringes and replace it with the second infusate containing the tracer along with the glucose. Repeat steps 4.2 through 4.7 using the glucose-rich isotopic glucose infusion.
	<ol>
		<li>To reach a steady state, run a bolus of the second infusate at 600 &#181;L/h for 15 min. Note the starting time for each group of cages. Decrease the infusion rate to 150 &#181;L/h to complete the 3 h of total infusion time.</li>
	</ol>
	</li>
	<li>Repeat steps 5.1 and 5.2.</li>
	<li>Stop the infusion pump and remove the tail vein catheter gently, apply pressure at the catheter sites until the bleeding stops, and return mice to their home cages.</li>
	<li>Santize and disinfect the caging setup thoroughly with standard soap and water. 
	NOTE: This is a survival procedure. Mice can be returned to cages and kept for further experiements if needed. It is recommended that no further experiementation is performed for at least a week following this procedure to ensure adequate animal welfare.</li>
</ol>
7. Mass spectrometry
<ol>
	<li>Send out the samples for mass spectrometry.</li>
	<li>Analyses
	<ol>
		<li>Measure the isotopic enrichment of [6,6-2H2]glucose by gaschromatography - mass spectrometry (GCMS) using the pentaacetate derivative21,22. Briefly, this method involves preparation of the pentaacetate derivative of glucose, followed by sample analysis using GCMS 20,22.</li>
	</ol>
	</li>
	<li>Calculations
	<ol>
		<li>Perform all kinetic measurements under steady state conditions. Total plasma glucose appearance rate (glucose Ra) was calculated from the M+2 enrichment of [6,6-2H2]glucose in plasma using established isotope dilution equations21. Under steady state conditions, it is assumed that the rate of appearance of glucose is equal to the rate of disappearance of glucose. Rate of endogenous glucose production (mg/(kg&#183;min)) (GPR) = glucoseRa - exogenous glucose.</li>
	</ol>
	</li>
</ol>

<ol>
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O., 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=Prevalence,+phenotype+and+cardiometabolic+risk+of+polycystic+ovary+syndrome+under+different+diagnostic+criteria.">Prevalence, phenotype and cardiometabolic risk of polycystic ovary syndrome under different diagnostic criteria.</a> Human Reproduction. 27 (10), 3067-3073 (2012).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Revised+2003+consensus+on+diagnostic+criteria+and+long-term+health+risks+related+to+polycystic+ovary+syndrome.">Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome.</a> Fertility and Sterility. 81 (1), 19-25 (2004).</li><li>Goodarzi, M. 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The authors have nothing to disclose.

Hyperglycemia and abnormal glucose metabolism/homeostasis are features of PCOS. Blood glucose level is maintained by a combination of glucose from diet and glucose production via glycogenolysis and gluconeogenesis and glycogenesis, under the control of hormone and enzymes. Hepatic glucose production is suppressed by the presence of increased circulating glucose levels. In disorders of abnormal glucose metabolism, regulation of the suppression of glucose production is compromised leading to hyperglycemia. While m...

Polycystic ovary syndrome (PCOS) is a common disorder occurring in 12%-20% of reproductive-aged women1,2. It is a complex disease resulting in variable phenotypes involving polycystic ovaries, irregular menses and clinical or laboratory evidence of hyperandrogenemia, and is typically diagnosed when a woman meets two of the three criteria3. A predominant aspect of PCOS, and a key factor in its pathogenesis, is metabolic derangements that are found in women who have the disease. Women with PCOS have higher incidences of insulin resistance, glucose intolerance, obesity, and metabolic syndrome3,4,5,6. Insulin resistance is not only a manifestation of the disease, but it is thought to contribute to its pathogenesis by potentiating the action of luteinizing hormone in the ovary thereby leading to increased androgen production7,8. Insulin resistance is thought to have several possible origins but studies suggest it may be due to abnormal patterns of insulin receptor signaling9,10. Studies have evaluated insulin resistance in PCOS patients using the gold standard technique of hyperinsulinemic-euglycemic clamp11,12,13,14,15. Women with PCOS, irrespective of BMI, have higher levels of insulin resistance compared with controls. Insulin control over glucose production is impaired in disorders of insulin resistance leading to excess glucose production. For example, diabetic patients have increased rates of gluconeogenesis and impaired suppression of glycogenolysis16. Furthermore, impaired suppression of glucose production has been observed in diabetic rats17. Although clamp studies can give a measurement of insulin resistance, few studies in PCOS focus on direct measurement of glucose production in fasting and fed states. This requires the use of a non-radioactive isotopic glucose tracer infusion and measurement via mass spectrometry.
Animal models have been extensively used in PCOS research. Both lean and obese-type PCOS murine models have been created by administering androgens prenatally, prepubertally, or post-pubertally18. Rodent PCOS models also demonstrate metabolic differences compared with their respective controls. Previous data from our lab demonstrated abnormal glucose tolerance tests (GTT) in PCOS mouse models (lean and obese), consistent with human PCOS literature19. Use of a lean and obese animal model allows further investigation into metabolic differences. Specifically, this model allows evaluation of the rate of glucose production directly using isotopic glucose tracers. One of the most commonly used stable isotopic glucose tracer is [6,6-2H2]glucose. The [6,6-2H2]glucose enrichment can be measured using a pentaacetate derivative as previously described20.
In this study, our aim was to measure the rate of hepatic glucose production in fasting and glucose-rich state in PCOS mice using isotopic glucose infusion. These techniques can be applied to a wide range of experiments involving glucose kinetics.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.9% sodium chloride solution</td>
			<td>McKesson</td>
			<td>275595</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mL BD Luer-Lok tip syringe</td>
			<td>VWR</td>
			<td>75846-756</td>
			<td>Two syringes per animal (one for isotopic glucose solution, one for glucose-rich isotopic solution)</td>
		</tr>
		<tr>
			<td>1-inch clear transpore tape</td>
			<td>3M</td>
			<td>70200400169</td>
			<td></td>
		</tr>
		<tr>
			<td>1-inch Labeling tape</td>
			<td>Fisher</td>
			<td>GS07F161BA</td>
			<td>Brand is example</td>
		</tr>
		<tr>
			<td>5 mL syringe containing heparanized saline flush</td>
			<td>McKesson</td>
			<td>191-MIH-2235</td>
			<td>One can also prepare a heparin flush solution (10 units/mL heparin in 0.9% sodium chloride)</td>
		</tr>
		<tr>
			<td>5 mm Medipoint Goldenrod animal lancets</td>
			<td>Fisher Scientific</td>
			<td>NC9891620</td>
			<td>5 mm if animal is between 2 and 6 months</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Sigma-Aldrich</td>
			<td>650501</td>
			<td></td>
		</tr>
		<tr>
			<td>Advanced hot plate stirrer</td>
			<td>VWR</td>
			<td>97042-602</td>
			<td>Brand is example</td>
		</tr>
		<tr>
			<td>BD 27 gauge 0.5 inch needles</td>
			<td>Health Warehouse</td>
			<td>A283952</td>
			<td></td>
		</tr>
		<tr>
			<td>BD 30 gauge 0.5 inch needles</td>
			<td>Medvet</td>
			<td>305106</td>
			<td></td>
		</tr>
		<tr>
			<td>BD Intramedic Polyethylene (PE) tubing 0.28 mm ID x 0.61 mm</td>
			<td>VWR</td>
			<td>63019-004</td>
			<td></td>
		</tr>
		<tr>
			<td>BD Intramedic Polyethylene (PE) tubing 0.28 mm ID x 0.61 mm</td>
			<td>VWR</td>
			<td>63019-004</td>
			<td></td>
		</tr>
		<tr>
			<td>Beaker, 1000 mL</td>
			<td></td>
			<td></td>
			<td>Any brand</td>
		</tr>
		<tr>
			<td>Caging pellets</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Clear VOA glass vials with closed-top cap</td>
			<td>Fisher Scientific</td>
			<td>05-719-120</td>
			<td>For storage of acetone and blood draw samples</td>
		</tr>
		<tr>
			<td>Copper toothless alligator clamp for tourniquet</td>
			<td>Amazon</td>
			<td></td>
			<td>Any Brand; smooth toothless alligator clips made of solid copper</td>
		</tr>
		<tr>
			<td>D-(+)-glucose &#62;99.5%</td>
			<td>Sigma-Aldrich</td>
			<td>G8270</td>
			<td></td>
		</tr>
		<tr>
			<td>D-glucose (6,6-D2, 99%)</td>
			<td>Cambridge Isotope Laboratories, Inc.</td>
			<td>DLM-349-PK</td>
			<td></td>
		</tr>
		<tr>
			<td>Dow Corning silastic tubing 0.3 mm ID x 0.64 mm OD</td>
			<td>VWR</td>
			<td>62999-042</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnifying glass</td>
			<td>Amazon</td>
			<td></td>
			<td>Any brand; similar to LANCOSC Magnifying Glass with Light and Stand</td>
		</tr>
		<tr>
			<td>Microbalance</td>
			<td>Ohaus Adventurer Pro</td>
			<td>AV264C</td>
			<td>Any similar model with 0.0001g accuracy can be used</td>
		</tr>
		<tr>
			<td>Nalgene bottle, 500 mL</td>
			<td>Sigma-Aldrich</td>
			<td>B0158-12EA</td>
			<td>Or any Similar brand; saw in half (including lid) and cut tail-sized notch in the bottom</td>
		</tr>
		<tr>
			<td>PHD Ultra multi-syringe pump</td>
			<td>Harvard Apparatus</td>
			<td>70-3024A</td>
			<td></td>
		</tr>
		<tr>
			<td>Plexiglass sheet</td>
			<td></td>
			<td></td>
			<td>Any brand; to stabalize mouse during catheter insertion</td>
		</tr>
		<tr>
			<td>Plexiglass sheets and dividers</td>
			<td></td>
			<td></td>
			<td>Any brand; used to cage mice during infusion</td>
		</tr>
	</tbody>
</table>

evaluation of hepatic glucose production in a polycystic ovary syndrome mouse model

Polycystic ovary syndrome (PCOS) is a common disease that results in disorders of glucose metabolism, such as insulin resistance and glucose intolerance. Dysregulated glucose metabolism is an important manifestation of the disease and is the key to its pathogenesis. Therefore, studies involving evaluation of glucose metabolism in PCOS are of utmost importance. Very few studies have quantified hepatic glucose production directly in PCOS models using non-radioactive glucose tracers. In this study, we discuss step-by-step instructions for the quantification of the rate of hepatic glucose production in a PCOS mouse model by measuring M+2 enrichment of [6,6-2H2]glucose, a stable isotopic glucose tracer, via gas chromatography - mass spectrometry (GCMS). This procedure involves creation of stable isotopic glucose tracer solution, use of tail vein catheter placement and infusion of the glucose tracer in both fasting and glucose-rich states in the same mouse in tandem. The enrichment of [6,6-2H2]glucose is measured using pentaacetate derivative in GCMS. This technique can be applied to a wide variety of studies involving direct measurement of the rate of hepatic glucose production.

Using previously described isotope dilution equations, the total plasma glucose rate (glucoseRa) was calculated from M+2 enrichment of [6,6-2H2]glucose in fasting and glucose-rich conditions using the pentaacetate derivative21. Under steady-state conditions, it is assumed that rate of appearance of glucose is equal to the rate of disappearance of glucose. In the control group, the total glucoseRa was 19.98 &#177; 2.53 mg/(kg&#183;min) after 6 h fasting a...

Watch this Scientific Journal Video about Evaluation of Hepatic Glucose Production in a Polycystic Ovary Syndrome Mouse Model at JoVE.com

Evaluation of Hepatic Glucose Production in a Polycystic Ovary Syndrome Mouse Model

This study describes the direct measurement of hepatic glucose production in a polycystic ovary syndrome mouse model by using a stable isotopic glucose tracer via tail vein in both fasting and glucose-rich states in tandem.

Polycystic ovary syndrome (PCOS) is a common disease that results in disorders of glucose metabolism, such as insulin resistance and glucose intolerance. ...

evaluation-hepatic-glucose-production-polycystic-ovary-syndrome-mouse

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

2.9K Views.  Baylor College of Medicine. This study describes the direct measurement of hepatic glucose production in a polycystic ovary syndrome mouse model by using a stable isotopic glucose tracer via tail vein in both fasting and glucose-rich states in tandem.

Video: Evaluation of Hepatic Glucose Production in a Polycystic Ovary Syndrome Mouse Model

Murine Bioluminescent Hepatic Tumour Model

This video describes the establishment of liver metastases in a mouse model that can be subsequently analysed by bioluminescent imaging. Tumour cells are administered specifically to the liver to induce a localised liver tumour, via mobilisation of the spleen and splitting into two, leaving intact the vascular pedicle for each half of the spleen. Lewis lung carcinoma cells that constitutively express the firefly luciferase gene (luc1) are inoculated into one hemi-spleen which is then resected 10 minutes later. The other hemi-spleen is left intact and returned to the abdomen. Liver tumour growth can be monitored by bioluminescence imaging using the IVIS whole body imaging system. Quantitative imaging of tumour growth using IVIS provides precise quantitation of viable tumour cells. Tumour cell death and necrosis due to drug treatment is indicated early by a reduction in the bioluminescent signal. This mouse model allows for investigating the mechanisms underlying metastatic tumour-cell survival and growth and can be used for the evaluation of therapeutics of liver metastasis. 

This article describes a procedure for the induction of orthotopic bioluminescent liver tumours in mice, and subsequent analysis of tumour growth confined to the liver using live whole body luminescence imaging.

This video describes the establishment of liver metastases in a mouse model that can be subsequently analysed by bioluminescent imaging. Tumour cells are ...

Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease

Conventional method to identify and classify individual chromosomes depends on the unique banding pattern of each chromosome in a specific species being analyzed 1, 2. This classical banding technique, however, is not reliable in identifying complex chromosomal aberrations such as those associated with cancer. To overcome the limitations of the banding technique, Spectral Karyotyping (SKY) is introduced to provide much reliable information on chromosome abnormalities.
SKY is a multicolor fluorescence in-situ hybridization (FISH) technique to detect metaphase chromosomes with spectral microscope 3, 4. SKY has been proven to be a valuable tool for the cytogenetic analysis of a broad range of chromosome abnormalities associated with a large number of genetic diseases and malignancies 5, 6. SKY involves the use of multicolor fluorescently-labelled DNA probes prepared from the degenerate oligonucleotide primers by PCR. Thus, every chromosome has a unique spectral color after in-situ hybridization with probes, which are differentially labelled with a mixture of fluorescent dyes (Rhodamine, Texas Red, Cy5, FITC and Cy5.5). The probes used for SKY consist of up to 55 chromosome specific probes 7-10.
The procedure for SKY involves several steps (Figure 1). SKY requires the availability of cells with high mitotic index from normal or diseased tissue or blood. The chromosomes of a single cell from either a freshly isolated primary cell or a cell line are spread on a glass slide. This chromosome spread is labeled with a different combination of fluorescent dyes specific for each chromosome. For probe detection and image acquisition,the spectral imaging system consists of sagnac interferometer and a CCD camera. This allows measurement of the visible light spectrum emitted from the sample and to acquire a spectral image from individual chromosomes. HiSKY, the software used to analyze the results of the captured images, provides an easy identification of chromosome anomalies. The end result is a metaphase and a karyotype classification image, in which each pair of chromosomes has a distinct color (Figure 2). This allows easy identification of chromosome identities and translocations. For more details, please visit Applied Spectral Imaging website (<a href="http://www.spectral-imaging.com/" target="_blank">http://www.spectral-imaging.com/</a>).
SKY was recently used for an identification of chromosome segregation defects and chromosome abnormalities in humans and mice with Autosomal Dominant Polycystic Kidney Disease (ADPKD), a genetic disease characterized by dysfunction in primary cilia 11-13. Using this technique, we demonstrated the presence of abnormal chromosome segregation and chromosomal defects in ADPKD patients and mouse models 14. Further analyses using SKY not only allowed us to identify chromosomal number and identity, but also to accurately detect very complex chromosomal aberrations such as chromosome deletions and translocations (Figure 2).

Spectral Karyotyping (SKY) is an advanced cytogenetics technique to identify genomic and chromosomal aberrations. This technique takes advantage of chromosome painting probes, which allow classification of all chromosomes. SKY can also identify complex chromosome aberrations and segregation defects in mice and humans with various diseases, including polycystic kidney disease.

Conventional method to identify and classify individual chromosomes depends on the unique banding pattern of each chromosome in a specific species being ...

A Preclinical Murine Model of Hepatic Metastases

Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, murine pancreatic tumor model of hepatic metastases via a hemispleen injection of syngeneic murine pancreatic tumor cells is described. This model mimics many of the clinical conditions in patients with metastatic disease to the liver. Mice consistently develop metastases in the liver allowing for investigation of the metastatic process, experimental therapy testing, and tumor immunology research.

A preclinical, murine model of hepatic metastases performed via a hemispleen injection technique.

Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, ...

A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation. Defects of the PCP pathway have been found to cause kidney cyst formation. Our paper describes a method for developing a zebrafish cystic kidney disease model by knockdown of the wnt5a gene with wnt5a antisense morpholino (MO) oligonucleotides. Tg(wt1b:GFP) transgenic zebrafish were used to visualize kidney structure and kidney cysts following wnt5a knockdown. Two distinct antisense MOs (AUG - and splice-site) were used and both resulted in curly tail down phenotype and cyst formation after wnt5a knockdown. Injection of mouse Wnt5a mRNA, resistant to the MOs due to a difference in primary base pair structure, rescued the abnormal phenotype, demonstrating that the phenotype was not due to &#8220;off-target&#8221; effects of the morpholino. This work supports the validity of using a zebrafish model to study wnt5a function in the kidney.

A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

We describe a method of generating a possible zebrafish model of polycystic kidney disease. We used Tg(wt1b:GFP) fish to visualize kidney structure. Knockdown of wnt5a was by morpholino injection. Pronephric cyst formation after wnt5a knockdown was observed in this GFP transgenic zebrafish.

Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The ...

Generation of a Humanized Mouse Liver Using Human Hepatic Stem Cells

A novel animal model involving chimeric mice with humanized livers established via human hepatocyte transplantation has been developed. These mice, in which the liver has been repopulated with functional human hepatocytes, could serve as a useful tool for investigating human hepatic cell biology, drug metabolism, and other preclinical applications. One of the key factors required for successful transplantation of human hepatocytes into mice is the elimination of the endogenous hepatocytes to prevent competition with the human cells and provide a suitable space and microenvironment for promoting human donor cell expansion and differentiation. To date, two major liver injury mouse models utilizing fumarylacetoacetate hydrolase (Fah) and uroplasminogen activator (uPA) mice have been established. However, Fah mice are used mainly with mature hepatocytes and the application of the uPA model is limited by decreased breeding. To overcome these limitations, Alb-toxin receptor mediated cell knockout (TRECK)/SCID mice were used for in vivo differentiation of immature human hepatocytes and humanized liver generation. Human hepatic stem cells (HpSCs) successfully repopulated the livers of Alb-TRECK/SCID mice that had developed lethal fulminant hepatic failure following diphtheria toxin (DT) treatment. This model of a humanized liver in Alb-TRECK/SCID mice will have functional applications in studies involving drug metabolism and drug-drug interactions and will promote other in vivo and in vitro studies.

Here, we present a novel humanized mouse liver model generated in Alb-toxin receptor mediated cell knockout (TRECK)/SCID mice following the transplantation of immature and expandable human hepatic stem cells.

A novel animal model involving chimeric mice with humanized livers established via human hepatocyte transplantation has been developed. These mice, in ...

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. Portal hypertension (PHT) due to cirrhosis is responsible for the most severe complications in patients with liver disease. The full picture of the portal hypertensive syndrome is characterized by increased portal pressure (PP) due to the increased intrahepatic vascular resistance (IHVR), hyperdynamic circulation, and increased splanchnic blood flow. Progressive splanchnic arterial vasodilation and increased cardiac output with elevated heart rate (HR) but low arterial pressure characterizes the portal hypertensive syndrome.
Novel therapies are currently being developed that aim to decrease PP by either targeting IHVR or increased splanchnic blood flow &#8212; but side effects on systemic hemodynamics may occur. Thus, a detailed characterization of portal venous, splanchnic, and systemic hemodynamic parameters, including measurement of PP, portal venous blood flow (PVBF), mesenteric arterial blood flow, mean arterial pressure (MAP), and HR is needed for preclinical evaluation of the efficacy of novel treatments for PHT. Our video article provides the reader with a structured protocol for performing invasive hemodynamic measurements in cirrhotic rats. In particular, we describe the catheterization of the femoral artery and the portal vein via an ileocolic vein and the measurement of portal venous and splanchnic blood flow via perivascular Doppler-ultrasound flow probes. Representative results of different rat models of PHT are shown.

Here we describe a detailed protocol for invasive measurements of hemodynamic parameters including portal pressure, splanchnic blood flow, and systemic hemodynamics in order to characterize the portal hypertensive syndrome in rats.

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. ...

Oleic Acid-Injection in Pigs As a Model for Acute Respiratory Distress Syndrome

The acute respiratory distress syndrome is a relevant intensive care disease with an incidence ranging between 2.2% and 19% of intensive care unit patients. Despite treatment advances over the last decades, ARDS patients still suffer mortality rates between 35 and 40%. There is still a need for further research to improve the outcome of patients suffering from ARDS. One problem is that no single animal model can mimic the complex pathomechanism of the acute respiratory distress syndrome, but several models exist to study different parts of it. Oleic acid injection (OAI)-induced lung injury is a well-established model for studying ventilation strategies, lung mechanics and ventilation/perfusion distribution in animals. OAI leads to severely impaired gas exchange, deterioration of lung mechanics and disruption of the alveolo-capillary barrier. The disadvantage of this model is the controversial mechanistic relevance of this model and the necessity for central venous access, which is challenging especially in smaller animal models. In summary, OAI-induced lung injury leads to reproducible results in small and large animals and hence represents a well-suited model for studying ARDS. Nevertheless, further research is necessary to find a model that mimics all parts of ARDS and lacks the problems associated with the different models existing today.

In this article, we present a protocol to induce acute lung injury in pigs by central-venous injection of oleic acid. This is an established animal model for studying the acute respiratory distress syndrome (ARDS).

The acute respiratory distress syndrome is a relevant intensive care disease with an incidence ranging between 2.2% and 19% of intensive care unit ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Standardized Histomorphometric Evaluation of Osteoarthritis in a Surgical Mouse Model

One of the most prevalent joint disorders in the United States, osteoarthritis (OA) is characterized by progressive degeneration of articular cartilage, primarily in the hip and knee joints, which results in significant impacts on patient mobility and quality of life. To date, there are no existing curative therapies for OA able to slow down or inhibit cartilage degeneration. Presently, there is an extensive body of ongoing research to understand OA pathology and discover novel therapeutic approaches or agents that can efficiently slow down, stop, or even reverse OA. Thus, it is crucial to have a quantitative and reproducible approach to accurately evaluate OA-associated pathological changes in the joint cartilage, synovium, and subchondral bone. Currently, OA severity and progression are primarily assessed using the Osteoarthritis Research Society International (OARSI) or Mankin scoring systems. In spite of the importance of these scoring systems, they are semiquantitative and can be influenced by user subjectivity. More importantly, they fail to accurately evaluate subtle, yet important, changes in the cartilage during the early disease states or early treatment phases. The protocol we describe here uses a computerized and semiautomated histomorphometric software system to establish a standardized, rigorous, and reproducible quantitative methodology for the evaluation of joint changes in OA. This protocol presents a powerful addition to the existing systems and allows for more efficient detection of pathological changes in the joint.

The current protocol establishes a rigorous and reproducible method for quantification of morphological joint changes that accompany osteoarthritis. Application of this protocol can be valuable in monitoring disease progression and evaluating therapeutic interventions in osteoarthritis.

One of the most prevalent joint disorders in the United States, osteoarthritis (OA) is characterized by progressive degeneration of articular cartilage, ...

Retinal Pathophysiological Evaluation in a Rat Model

A posterior segment eye disease like diabetic retinopathy alters the physiology of the retina. Diabetic retinopathy is characterized by a retinal detachment, breakdown of the blood-retinal barrier (BRB), and retinal angiogenesis. An in vivo rat model is a valuable experimental tool to examine the changes in the structure and function of the retina. We propose three different experimental techniques in the rat model to identify morphological changes of retinal cells, retinal vasculature, and compromised BRB. Retinal histology is used to study the morphology of various retinal cells. Also, quantitative measurement is performed by retinal cell count and thickness measurement of different retinal layers. A BRB breakdown assay is used to determine the leakage of extraocular proteins from the plasma to vitreous tissue due to the breakdown of BRB. Fluorescence angiography is used to study angiogenesis and leakage of blood vessels by visualizing retinal vasculature using FITC-dextran dye.

Diabetic retinopathy is one of the leading causes of blindness. Histology, blood-retinal barrier breakdown assay, and fluorescence angiography are valuable techniques to understand the pathophysiology of the retina, which could further enhance the efficient drug screening against diabetic retinopathy.

Evaluation of Hepatic Glucose Production in a Polycystic Ovary Syndrome Mouse Model

Summary

Explore More Videos

Chapters in this video

Murine Bioluminescent Hepatic Tumour Model

Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease

A Preclinical Murine Model of Hepatic Metastases

A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

Generation of a Humanized Mouse Liver Using Human Hepatic Stem Cells

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats

Oleic Acid-Injection in Pigs As a Model for Acute Respiratory Distress Syndrome

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

Standardized Histomorphometric Evaluation of Osteoarthritis in a Surgical Mouse Model

Retinal Pathophysiological Evaluation in a Rat Model