This work was supported by grants from the NIH: R03 DK089061-01 (VKY); NIH: K08 DK068391 (VKY); the Diabetes and Endocrinology Research Center-(DERC - P30DK079638) at Baylor College of Medicine, a Pilot &amp; Feasibility grant from the DERC (VKY); Juvenile Diabetes Research Foundation: JDRF Award # 5-2006-134 (VKY).

<ol>
	<li>Parks, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+helper-dependent+adenovirus+vector+system:+removal+of+helper+virus+by+Cre-mediated+excision+of+the+viral+packaging+signal.">A helper-dependent adenovirus vector system: removal of helper virus by Cre-mediated excision of the viral packaging signal.</a> Proc. Natl. Acad. Sci. U. S. A. 93, 13565-13570 (1996).</li><li>Kim, I. H., Jozkowicz, A., Piedra, P. A., Oka, K., Chan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lifetime+correction+of+genetic+deficiency+in+mice+with+a+single+injection+of+helper-dependent+adenoviral+vector.">Lifetime correction of genetic deficiency in mice with a single injection of helper-dependent adenoviral vector.</a> Proc. Natl. Acad. Sci. U.S.A. 98, 13282-13287 (2001).</li><li>Belalcazar, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+stable+expression+of+human+apolipoprotein+A-I+mediated+by+helper-dependent+adenovirus+gene+transfer+inhibits+atherosclerosis+progression+and+remodels+atherosclerotic+plaques+in+a+mouse+model+of+familial+hypercholesterolemia.">Long-term stable expression of human apolipoprotein A-I mediated by helper-dependent adenovirus gene transfer inhibits atherosclerosis progression and remodels atherosclerotic plaques in a mouse model of familial hypercholesterolemia.</a> Circulation. 107, 2726-2732 (2003).</li><li>Oka, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+stable+correction+of+low-density+lipoprotein+receptor-deficient+mice+with+a+helper-dependent+adenoviral+vector+expressing+the+very+low-density+lipoprotein+receptor.">Long-term stable correction of low-density lipoprotein receptor-deficient mice with a helper-dependent adenoviral vector expressing the very low-density lipoprotein receptor.</a> Circulation. 103, 1274-1281 (2001).</li><li>Nomura, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-density+lipoprotein+receptor+gene+therapy+using+helper-dependent+adenovirus+produces+long-term+protection+against+atherosclerosis+in+a+mouse+model+of+familial+hypercholesterolemia.">Low-density lipoprotein receptor gene therapy using helper-dependent adenovirus produces long-term protection against atherosclerosis in a mouse model of familial hypercholesterolemia.</a> Gene Ther. 11, 1540-1548 (2004).</li><li>Ng, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+high-efficiency+Cre/loxP-based+system+for+construction+of+adenoviral+vectors.">A high-efficiency Cre/loxP-based system for construction of adenoviral vectors.</a> Hum. Gene Ther. 10, 2667-2672 (1999).</li><li>Palmer, D., Ng, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+system+for+helper-dependent+adenoviral+vector+production.">Improved system for helper-dependent adenoviral vector production.</a> Mol. Ther. 8, 846-852 (2003).</li><li>Oka, K., Chan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Helper-Dependent+Adenoviral+Vectors.">Helper-Dependent Adenoviral Vectors.</a> Current Protocols in Molecular Biology. , 16.24.1-16.24.23 (2005).</li><li>Yechoor, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurogenin3+is+sufficient+for+transdetermination+of+hepatic+progenitor+cells+into+neo-islets+in+vivo+but+not+transdifferentiation+of+hepatocytes.">Neurogenin3 is sufficient for transdetermination of hepatic progenitor cells into neo-islets in vivo but not transdifferentiation of hepatocytes.</a> Dev. Cell. 16, 358-373 (2009).</li><li>Yechoor, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+Therapy+with+Neurogenin+3+and+Betacellulin+Reverses+Major+Metabolic+Problems+in+Insulin-Deficient+Diabetic+Mice.">Gene Therapy with Neurogenin 3 and Betacellulin Reverses Major Metabolic Problems in Insulin-Deficient Diabetic Mice.</a> Endocrinology. , (2009).</li></ol>

No conflicts of interest declared.

HDAds have been developed to overcome the weakness of early generation Ads and to harness for gene therapy application. However, technical challenges remain. For example, HDAd requires HV for HDAd's packaging and vector amplification is not as efficient as early generation Ads. HV is a first generation Ad and any contamination of HV compromise the effectiveness of HDAd. Therefore, highly efficient transfection and optimal conditions for each serial passage are critical. Another critical parameter for vector production is which passage (P1-P4) should be used for subsequent passage 5 that is directly used as inoculum for suspension cells. To our experience, the best results are obtained by using the passage by which HDAd vector proportion is dramatically increased in the following passage (P3 in Figure 2). The yield of HDAd vectors depends on transgene cassettes. During vector production, both transgenes are expressed because both genes are under ubiquitous promoter. Ngn3 is a transcription factor and Btc is a growth factor, which suggests that HDAd vector expressing transcription factor which may influence cell lineage inhibits vector amplification while that expressing growth hormone helps in vector replication and packaging.
With diabetes assuming epidemic proportions, new approaches to restore b-cell mass are needed. In this report, we describe methods to harness the advantages of HDAd vectors to effect gene transfer of islet lineage-defining transcription factor, Ngn3 along with the islet growth factor, betacellulin to induce islet neogenesis in periportal regions of the liver. To assess the efficacy of this, it is important to choose mice with stable hyperglycemia and ensure that appropriate controls are always included. For this gene transfer experiments, the empty vector treated diabetic mice should always be utilized. In addition, using HDAd-Ngn3 and HDAd-Btc individually treated diabetic mice serves to test the individual contribution of these two genes in islet neogenesis. As our data demonstrates that Ngn3 alone is sufficient to induce islet neogenesis, but the addition of the growth factor, Btc, serves to augment the response leading to robust induction of islet neogenesis. It is also important to test that the vector expression is indeed achieved in the target tissue, the liver and also to demonstrate that the insulin assayed in the plasma of treated mice is not coming from residual islets in the pancreas, by demonstrating the absence of pancreatic islets in the diabetic mice.
In summary, the advantage of the HDAd-vector system for gene transfer lies in its high cloning capacity, efficient transduction and long lasting gene expression in the liver with minimum chronic toxicity as well as its nature of non-integration of vector genome into the host chromosome. The primary limitations are the complex steps involved in its generation and its in vivo application is primarily limited to the liver with the most popular Ad serotype 5. Islet neogenesis can be induced to fully restore plasma insulin and glucose tolerance in diabetic mice by inducing islet neogenesis in the liver by gene transfer of islet lineage-defining transcription factor, Ngn3 along with the islet growth factor, betacellulin. In this report, we show the optimal protocol to generate high quality HDAd-Ngn3 and HDAd-Btc, and demonstrate techniques to induce and assess islet neogenesis in the livers of diabetic mice to reverse hyperglycemia.
Footnote: The viral vectors and the cell lines described here are available from the Vector Production Core Laboratory, Diabetes Research Center, Baylor College of Medicine (<a href="http://www.bcm.edu/mcb/index.cfm?pmid=7731" target="_blank">http://www.bcm.edu/mcb/index.cfm?pmid=7731</a>). Some commercial kits are also available for generating HDAd viruses (e.g. Microbix biosystems Inc.).

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 </tr>
 <tr>
 <td>ProFectionR Mammalian Transfection kit</td>
 <td>Promega</td>
 <td>E1200</td>
 </tr>
 <tr>
 <td>DNeasy Blood &amp; Tissue Kit (50)</td>
 <td>Qiagen</td>
 <td>69504</td>
 </tr>
 <tr>
 <td>PerfeCTa SYBR Green SuperMix, ROX</td>
 <td>Quanta Biosciences</td>
 <td>95055-500</td>
 </tr>
 <tr>
 <td>Sodium deoxycholate</td>
 <td>Sigma</td>
 <td>D6750-25G</td>
 </tr>
 <tr>
 <td>MEM powder</td>
 <td>Invitrogen</td>
 <td>61100087</td>
 </tr>
 <tr>
 <td>Penicillin Streptomycin</td>
 <td>Sigma</td>
 <td>15140122</td>
 </tr>
 <tr>
 <td>FBS</td>
 <td>Atlanta Biologicals</td>
 <td>S11150</td>
 </tr>
 <tr>
 <td>L-glutamine</td>
 <td>Invitrogen</td>
 <td>25030-081</td>
 </tr>
 <tr>
 <td>Hygromycin B</td>
 <td>Sigma</td>
 <td>H0654-1G</td>
 </tr>
 <tr>
 <td>MEM EAGLE JOKLIK</td>
 <td>Sigma</td>
 <td>M0518-10L</td>
 </tr>
 <tr>
 <td>Rnase</td>
 <td>Roche</td>
 <td>10109169001</td>
 </tr>
 <tr>
 <td>DNase I, grade II</td>
 <td>Roche</td>
 <td>10104159001</td>
 </tr>
 <tr>
 <td>Streptozocin</td>
 <td>Sigma</td>
 <td>s0130</td>
 </tr>
 <tr>
 <td>Glass spinner flasks</td>
 <td>Corning</td>
 <td>4500-3L</td>
 </tr>
 <tr>
 <td>Glass spinner flasks</td>
 <td>Corning</td>
 <td>4500-250</td>
 </tr>
 <tr>
 <td>Slide A-lyzer casset</td>
 <td>PIERCE CH</td>
 <td>PI66380</td>
 </tr>
 <tr>
 <td>Tube optiseal poly allomer, 11.2 ml</td>
 <td>Beckman Coulter</td>
 <td>362181</td>
 </tr>
 <tr>
 <td>Cesium chloride 1 kg</td>
 <td>JT4042-2</td>
 <td>VWR</td>
 </tr>
 <tr>
 <td>Beckman LE-80K</td>
 <td>Beckman Coulter</td>
 <td>Optimal LE-80K ultracentrifuge</td>
 </tr>
 <tr>
 <td>Filter</td>
 <td>VWR</td>
 <td>28143-338</td>
 </tr>
 <tr>
 <td>centrifuge tube 500 ml</td>
 <td>Corning</td>
 <td>431123</td>
 </tr>
 <tr>
 <td>tailveiner restrainer</td>
 <td>Braintree scientific , INC</td>
 <td>tv-150</td>
 </tr>
 <tr>
 <td>Insulin, Mouse ELISA</td>
 <td>Mercodia</td>
 <td>10-1247-01</td>
 </tr>
 <tr>
 <td>microvette CB300</td>
 <td>Sarstedt</td>
 <td>16.443.100</td>
 </tr>
 <tr>
 <td>D-glucose</td>
 <td>Sigma</td>
 <td>G8270</td>
 </tr>
 <tr>
 <td>Mouse C-peptide ELISA Kit</td>
 <td>Wako Pure Chemical Industries, Ltd</td>
 <td>#631-07231</td>
 </tr>
 <tr>
 <td>guinea pig anti-insulin antibody</td>
 <td>Abcam</td>
 <td>ab7842</td>
 </tr>
 <tr>
 <td>goat anti-Pdx1 antibody</td>
 <td>gift from Dr. Christopher Wright</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>mouse anti Ngn3 antibody</td>
 <td>Beta Cell Biology Consortium, 
 Univ. of Pennsylvania</td>
 <td>AB2013</td>
 </tr>
 <tr>
 <td>mouse anti Nkx6.1 antibody</td>
 <td>Beta Cell Biology Consortium, 
 Univ. of Pennsylvania</td>
 <td>F64A6B4</td>
 </tr>
 <tr>
 <td>anti- betacellulin antibody</td>
 <td>Cell Sciences</td>
 <td>PAAQ1</td>
 </tr>
 <tr>
 <td>ALT (SGPT) Color Reagent SET.</td>
 <td>Teco Diagnostics</td>
 <td>A526 - 120</td>
 </tr>
 <tr>
 <td>AST/(SGOT), Color Endpoint Reagent Set</td>
 <td>Teco Diagnostics</td>
 <td>A561-120</td>
 </tr>
 </tbody>
</table>
Table 2. Specific Reagents and Equipment.

neo-islet formation in liver of diabetic mice by helper-dependent adenoviral vector-mediated gene transfer

Type 1 diabetes is caused by T cell-mediated autoimmune destruction of insulin-producing cells in the pancreas. Until now insulin replacement is still the major therapy, because islet transplantation has been limited by donor availability and by the need for long-term immunosuppression. Induced islet neogenesis by gene transfer of Neuogenin3 (Ngn3), the islet lineage-defining specific transcription factor and Betacellulin (Btc), an islet growth factor has the potential to cure type 1 diabetes.
Adenoviral vectors (Ads) are highly efficient gene transfer vector; however, early generation Ads have several disadvantages for in vivo use. Helper-dependent Ads (HDAds) are the most advanced Ads that were developed to improve the safety profile of early generation of Ads and to prolong transgene expression1. They lack chronic toxicity because they lack viral coding sequences2-5 and retain only Ad cis elements necessary for vector replication and packaging. This allows cloning of up to 36 kb genes.
In this protocol, we describe the method to generate HDAd-Ngn3 and HDAd-Btc and to deliver these vectors into STZ-induced diabetic mice. Our results show that co-injection of HDAd-Ngn3 and HDAd-Btc induces 'neo islets' in the liver and reverses hyperglycemia in diabetic mice.

Watch this Scientific Journal Video about Neo-Islet Formation in Liver of Diabetic Mice by Helper-dependent Adenoviral Vector-Mediated Gene Transfer at JoVE.com

Neo-Islet Formation in Liver of Diabetic Mice by Helper-dependent Adenoviral Vector-Mediated Gene Transfer

We describe hepatic neo-islet formation in STZ (streptozotocin)-induced diabetic mice by gene transfer of Neurogenin3 (Ngn3) and Betacellulin (Btc) using helper-dependent adenoviral vector (HDAd) and the reversal of hyperglycemia. Our method takes advantages of helper-dependent adenoviral vectors with their highly efficient in vivo transduction and the long lasting gene expression.

Type 1 diabetes is caused by T cell-mediated autoimmune destruction of insulin-producing cells in the pancreas. Until now insulin replacement is still the ...

neo-islet-formation-liver-diabetic-mice-helper-dependent-adenoviral

Research

JoVE Journal

Medicine

11.7K Views.  Baylor College of Medicine. We describe hepatic neo-islet formation in STZ (streptozotocin)-induced diabetic mice by gene transfer of Neurogenin3 (Ngn3) and Betacellulin (Btc) using helper-dependent adenoviral vector (HDAd) and the reversal of hyperglycemia. Our method takes advantages of helper-dependent adenoviral vectors with their highly efficient in vivo transduction and the long lasting gene expression.

Video: Neo-Islet Formation in Liver of Diabetic Mice by Helper-dependent Adenoviral Vector-Mediated Gene Transfer

Use of a Hanging-weight System for Liver Ischemia in Mice

Acute liver injury due to ischemia can occur during several clinical procedures e.g. liver transplantation, hepatic tumor resection or trauma repair and can result in liver failure which has a high mortality rate1-2. Therefore murine studies of hepatic ischemia have become an important field of research by providing the opportunity to utilize pharmacological and genetic studies3-9. Specifically, conditional mice with tissue specific deletion of a gene (cre, flox system) provide insights into the role of proteins in particular tissues10-13 . Because of the technical difficulty associated with manually clamping the portal triad in mice, we performed a systematic evaluation using a hanging-weight system for portal triad occlusion which has been previously described3. By using a hanging-weight system we place a suture around the left branch of the portal triad without causing any damage to the hepatic lobes, since also the finest clamps available can cause hepatic tissue damage because of the close location of liver tissue to the vessels. Furthermore, the right branch of the hepatic triad is still perfused thus no intestinal congestion occurs with this technique as blood flow to the right hepatic lobes is preserved. Furthermore, the portal triad is only manipulated once throughout the entire surgical procedure. As a result, procedures like pre-conditioning, with short times of ischemia and reperfusion, can be easily performed. Systematic evaluation of this model by performing different ischemia and reperfusion times revealed a close correlation of hepatic ischemia time with liver damage as measured by alanine (ALT) and aspartate (AST) aminotransferase serum levels3,9. Taken together, these studies confirm highly reproducible liver injury when using the hanging-weight system for hepatic ischemia and intermittent reperfusion. Thus, this technique might be useful for other investigators interested in liver ischemia studies in mice. Therefore the video clip provides a detailed step-by-step description of this technique.

We established a novel murine model of a hanging weight system for portal triad occlusion. This technique may be useful for future investigations of ischemia in murine hepatic models.

Acute liver injury due to ischemia can occur during several clinical procedures e.g. liver transplantation, hepatic tumor resection or trauma repair and ...

Establishment and Propagation of Human Retinoblastoma Tumors in Immune Deficient Mice

Culturing retinoblastoma tumor cells in defined stem cell media gives rise to primary tumorspheres that can be grown and maintained for only a limited time. These cultured tumorspheres may exhibit markedly different cellular phenotypes when compared to the original tumors. Demonstration that cultured cells have the capability of forming new tumors is important to ensure that cultured cells model the biology of the original tumor. 
Here we present a protocol for propagating human retinoblastoma tumors in vivo using Rag2-/- immune deficient mice. Cultured human retinoblastoma tumorspheres of low passage or cells obtained from freshly harvested human retinoblastoma tumors injected directly into the vitreous cavity of murine eyes form tumors within 2-4 weeks. These tumors can be harvested and either further passaged into murine eyes in vivo or grown as tumorspheres in vitro. Propagation has been successfully carried out for at least three passages thus establishing a continuing source of human retinoblastoma tissue for further experimentation. 
Wesley S. Bond and Lalita Wadhwa are co-first authors.

A method is described to propagate human retinoblastoma tumors in mice. Tumor cells are directly injected into the eyes of immune deficient mice. Secondary tumors have been successfully established using both cells directly harvested from human tumors and cultured tumorspheres.

Culturing retinoblastoma tumor cells in defined stem cell media gives rise to primary tumorspheres that can be grown and maintained for only a limited ...

Gene Transfer for Ischemic Heart Failure in a Preclinical Model

Various emerging technologies are being developed for patients with heart failure. Well-established preclinical evaluations are necessary to determine their efficacy and safety.
Gene therapy using viral vectors is one of the most promising approaches for treating cardiac diseases. Viral delivery of various different genes by changing the carrier gene has immeasurable therapeutic potential.
In this video, the full process of an animal model of heart failure creation followed by gene transfer is presented using a swine model. First, myocardial infarction is created by occluding the proximal left anterior descending coronary artery. Heart remodeling results in chronic heart failure. Unique to our model is a fairly large scar which truly reflects patients with severe heart failure who require aggressive therapy for positive outcomes. After myocardial infarct creation and development of scar tissue, an intracoronary injection of virus is demonstrated with simultaneous nitroglycerine infusion. Our injection method provides simple and efficient gene transfer with enhanced gene expression. This combination of a myocardial infarct swine model with intracoronary virus delivery has proven to be a consistent and reproducible methodology, which helps not only to test the effect of individual gene, but also compare the efficacy of many genes as therapeutic candidates.

A method of gene transfer for the treatment of ischemic heart failure is described using a swine model of myocardial infarction. Our simple and reproducible method enables us to readily evaluate the efficacy of various gene transfers with a very simple and reproducible way.

Various emerging technologies are being developed for patients with heart failure. Well-established preclinical evaluations are necessary to determine ...

Assessment of Gastric Emptying in Non-obese Diabetic Mice Using a [13C]-octanoic Acid Breath Test

Gastric emptying studies in mice have been limited by the inability to follow gastric emptying changes in the same animal since the most commonly used techniques require killing of the animals and postmortem recovery of the meal1,2. This approach prevents longitudinal studies to determine changes in gastric emptying with age and progression of disease. The commonly used [13C]-octanoic acid breath test for humans3 has been modified for use in mice4-6 and rats7 and we previously showed that this test is reliable and responsive to changes in gastric emptying in response to drugs and during diabetic disease progression8. In this video presentation the principle and practical implementation of this modified test is explained. As in the previous study, NOD LtJ mice are used, a model of type 1 diabetes9. A proportion of these mice develop the symptoms of gastroparesis, a complication of diabetes characterized by delayed gastric emptying without mechanical obstruction of the stomach10.
This paper demonstrates how to train the mice for testing, how to prepare the test meal and obtain 4 hr gastric emptying data and how to analyze the obtained data. The carbon isotope analyzer used in the present study is suitable for the automatic sampling of the air samples from up to 12 mice at the same time. This technique allows the longitudinal follow-up of gastric emptying from larger groups of mice with diabetes or other long-standing diseases.

Assessment of Gastric Emptying in Non-obese Diabetic Mice Using a [13C]-octanoic Acid Breath Test

Determination of gastric emptying with a non-invasive [13C]-octanoic acid breath test for tracking gastroparesis in female NOD LtJ mice.

Gastric emptying studies in mice have been limited by the inability to follow gastric emptying changes in the same animal since the most commonly used ...

Vascular Gene Transfer from Metallic Stent Surfaces Using Adenoviral Vectors Tethered through Hydrolysable Cross-linkers

In-stent restenosis presents a major complication of stent-based revascularization procedures widely used to re-establish blood flow through critically narrowed segments of coronary and peripheral arteries. Endovascular stents capable of tunable release of genes with anti-restenotic activity may present an alternative strategy to presently used drug-eluting stents. In order to attain clinical translation, gene-eluting stents must exhibit predictable kinetics of stent-immobilized gene vector release and site-specific transduction of vasculature, while avoiding an excessive inflammatory response typically associated with the polymer coatings used for physical entrapment of the vector. This paper describes a detailed methodology for coatless tethering of adenoviral gene vectors to stents based on a reversible binding of the adenoviral particles to polyallylamine bisphosphonate (PABT)-modified stainless steel surface via hydrolysable cross-linkers (HC). A family of bifunctional (amine- and thiol-reactive) HC with an average t1/2 of the in-chain ester hydrolysis ranging between 5 and 50 days were used to link the vector with the stent. The vector immobilization procedure is typically carried out within 9 hr&#160;and consists of several steps: 1) incubation of the metal samples in an aqueous solution of PABT (4 hr); 2) deprotection of thiol groups installed in PABT with tris(2-carboxyethyl) phosphine (20 min); 3) expansion of thiol reactive capacity of the metal surface by reacting the samples with polyethyleneimine derivatized with pyridyldithio (PDT) groups (2 hr); 4) conversion of PDT groups to thiols with dithiothreitol (10 min); 5) modification of adenoviruses with HC (1 hr); 6) purification of modified adenoviral particles by size-exclusion column chromatography (15 min) and 7) immobilization of thiol-reactive adenoviral particles on the thiolated steel surface (1 hr). This technique has wide potential applicability beyond stents, by facilitating surface engineering of bioprosthetic devices to enhance their biocompatibility through the substrate-mediated gene delivery to the cells interfacing the implanted foreign material.

These studies report on reversible attachment of adenoviral gene vectors to coatless metal surfaces of stents and model mesh disks. Sustained release of transduction-competent viral particles contingent upon hydrolysis of cross-linkers used for vector immobilization results in a durable site-specific transgene expression in vascular cells and in stented arteries.

In-stent restenosis presents a major complication of stent-based revascularization procedures widely used to re-establish blood flow through critically ...

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 ...

Functional Human Liver Preservation and Recovery by Means of Subnormothermic Machine Perfusion

There is currently a severe shortage of liver grafts available for transplantation. Novel organ preservation techniques are needed to expand the pool of donor livers. Machine perfusion of donor liver grafts is an alternative to traditional cold storage of livers and holds much promise as a modality to expand the donor organ pool. We have recently described the potential benefit of subnormothermic machine perfusion of human livers. Machine perfused livers showed improving function and restoration of tissue ATP levels. Additionally, machine perfusion of liver grafts at subnormothermic temperatures allows for objective assessment of the functionality and suitability of a liver for transplantation. In these ways a great many livers that were previously discarded due to their suboptimal quality can be rescued via the restorative effects of machine perfusion and utilized for transplantation. Here we describe this technique of subnormothermic machine perfusion in detail. Human liver grafts allocated for research are perfused via the hepatic artery and portal vein with an acellular oxygenated perfusate at 21 &#176;C.

We describe a method of ex vivo machine perfusion of human liver grafts at subnormothermic temperature (21 &#176;C).

There is currently a severe shortage of liver grafts available for transplantation.  Novel organ preservation techniques are needed to expand the pool of ...

In Vivo Gene Transfer to the Rabbit Common Carotid Artery Endothelium

The goal of this method is to introduce a transgene into the endothelium of isolated segments of both rabbit common carotid arteries. The method achieves focal endothelial-selective transgenesis, thereby allowing an investigator to determine the biological roles of endothelial-expressed transgenes and to quantify the in vivo transcriptional activity of DNA sequences in large artery endothelial cells. The method uses surgical isolation of rabbit common carotid arteries and an arteriotomy to deliver a transgene-expressing viral vector into the arterial lumen. A short incubation period of the vector in the lumen, with subsequent aspiration of the lumen contents, is sufficient to achieve efficient and durable expression of the transgene in the endothelium, with no detectable transduction or expression outside of the isolated arterial segment. The method allows assessment of the biological activities of transgene products both in normal arteries and in models of human vascular disease, while avoiding systemic effects that could be caused either by targeting gene delivery to other sites (e.g. the liver) or by the alternative approach of delivering genetic constructs to the endothelium by germ line transgenesis. Application of the method is limited by the need for a skilled surgeon and anesthetist, a well-equipped operating room, the costs of purchasing and housing rabbits, and the need for expertise in gene-transfer vector construction and use. Results obtained with this method include: transgene-related alterations in arterial structure, cellularity, extracellular matrix, or vasomotor function; increases or reductions in arterial inflammation; alterations in vascular cell apoptosis; and progression, retardation, or regression of diseases such as intimal hyperplasia or atherosclerosis. The method also allows measurement of the ability of native and synthetic DNA regulatory sequences to alter transgene expression in endothelial cells, providing results that include: levels of transgene mRNA, levels of transgene protein, and levels of transgene enzymatic activity.

In Vivo Gene Transfer to the Rabbit Common Carotid Artery Endothelium

This method is to introduce a transgene into the endothelium of rabbit carotid arteries. Introduction of the transgene allows the assessment of the biological role of the transgene product either in normal arteries or disease models. The method is also useful for measuring activity of DNA regulatory sequences.

The goal of this method is to introduce a transgene into the endothelium of isolated segments of both rabbit common carotid arteries. The method achieves ...

Protocol to Create Chronic Wounds in Diabetic Mice

Chronic wounds develop as a result of defective regulation in one or more complex cellular and molecular processes involved in proper healing. They impact ~6.5M people and cost ~$40B/year in the US alone. Although a significant effort has been invested in understanding how chronic wounds develop in humans, fundamental questions remain unanswered. Recently, we developed a novel mouse model for diabetic chronic wounds that have many characteristics of human chronic wounds. Using db/db-/- mice, we can generate chronic wounds by inducing high levels of oxidative stress (OS) in the wound tissue immediately after wounding, using a one-time treatment with inhibitors specific to the antioxidant enzymes catalase and glutathione peroxidase. These wounds have high levels of OS, develop biofilm naturally, become fully chronic within 20 days after treatment and can remain open more for more than 60 days. This novel model has many features of diabetic chronic wounds in humans and therefore can contribute significantly to advancing fundamental understanding of how wounds become chronic. This is a major breakthrough because chronic wounds in humans cause significant pain and distress to patients and result in amputation if unresolved. Moreover, these wounds are very expensive and time-consuming to treat, and lead to significant loss of personal income to patients. Advancements in this field of study through the use of our chronic wound model can significantly improve health care for millions who suffer under this debilitating condition. In this protocol, we describe in great detail the procedure to cause acute wounds to become chronic, which has not been done before.

Chronic wounds are developed from acute wounds on a diabetic mouse model by inducing high levels of oxidative stress after a full-thickness cutaneous wound. The wound is treated with inhibitors for catalase and glutathione peroxidase, resulting in impaired healing and biofilm development by bacteria present in the skin microbiome.

Chronic wounds develop as a result of defective regulation in one or more complex cellular and molecular processes involved in proper healing. They impact ...

Lentiviral Vector-mediated Gene Therapy of Hepatocytes Ex Vivo for Autologous Transplantation in Swine

Gene therapy is an ideal choice to cure many inborn errors of metabolism of the liver. Ex-vivo, lentiviral vectors have been used successfully in the treatment of many hematopoietic diseases in humans, as their use offers stable transgene expression due to the vector&#39;s ability to integrate into the host genome. This method demonstrates the application of ex vivo gene therapy of hepatocytes to a large animal model of hereditary tyrosinemia type I. This process consists of 1) isolation of primary hepatocytes from the autologous donor/recipient animal, 2) ex vivo gene delivery via hepatocyte transduction with a lentiviral vector, and 3) autologous transplant of corrected hepatocytes via portal vein injection. Success of the method generally relies upon efficient and sterile removal of the liver resection, careful handling of the excised specimen for isolation of viable hepatocytes sufficient for re-engrafting, high-percentage transduction of the isolated cells, and aseptic surgical procedures throughout to prevent infection. Technical failure at any of these steps will result in low yield of viable transduced hepatocytes for autologous transplant or infection of the donor/recipient animal. The pig model of human type 1 hereditary tyrosinemia (HT-1) chosen for this approach is uniquely amenable to such a method, as even a small percentage of engraftment of corrected cells will lead to repopulation of the liver with healthy cells based on a powerful selective advantage over native-diseased hepatocytes. Although this growth selection will not be true for all indications, this approach is a foundation for expansion into other indications and allows for manipulation of this environment to address additional diseases, both within the liver and beyond, while controlling for exposure to viral vector and opportunity for off-target toxicity and tumorigenicity.

Lentiviral Vector-mediated Gene Therapy of Hepatocytes Ex Vivo for Autologous Transplantation in Swine

This protocol is intended to describe porcine hepatocyte isolation and ex vivo gene delivery to cure models of metabolic diseases via autologous cell transplantation. Although this particular model enjoys unique advantages that favor successful therapy, the application is a relevant foundation to address additional diseases and indications.

Gene therapy is an ideal choice to cure many inborn errors of metabolism of the liver. Ex-vivo, lentiviral vectors have been used successfully in the ...