In Vivo Models and Cell Delivery for Lung Indications Marlowe Eldridge MD Department of Pediatrics and Biomedical Engineering University of Wisconsin School of Medicine and Public Health NO DISCLOSURES Manabezho Falls, Upper Peninsula of Michigan
FACTORS TO CONSIDER FOR SELECTING THE APPROPRIATE ANIMAL MODEL What is the primary question? Safety? Efficacy? How closely does the animal model translate to the human disease and stage of disease? What are the technical challenges of the model development? Does the model allow measurement of relevant physiologic information? Does the model allow mimicking of the planned human dosing schedule? CURRENT MODELS FOR BPD Hyperoxia Percentage of inspired oxygen (FIO2) Duration of administration Timing of administration Mechanical ventilation Hyperoxia and mechanical ventilation
RAT MODEL OF BRONCHOPULMONARY DYSPLASIA BRONCHOPULMONARY DYSPLASIA
BDP DISEASE ETIOLOGY AND AT-RISK POPULATION Typically seen in the following population: Premature babies <1500 g birth weight Mechanical ventilation Oxygen therapy 20-30% of ventilated newborns develop BPD Defined by: Disrupted distal lung growth Requirement of supplemental oxygen for hypoxemia Abnormal chest radiograph at 36 weeks Persistent respiratory signs and symptoms Kinsella, J.P., Greenough, A., and Abman, S.H. 2006. Bronchopulmonary dysplasia. Lancet 367:1421-1431. CHOOSING THE ANIMAL MODEL Mimic the disease as closely as possible Bronchopulmonary dysplasia Decreased alveolarization and septation of alveoli Decreased pulmonary vascularity Access to animals, cost, housing (ease) Rats born with lungs developed to point of pre-term human Ability to achieve endpoints in your model Comparability of animal to human
BPD FEATURES Airways: Fewer and simplified alveoli Increased smooth muscle in airways Vasculature: High pulmonary vascular resistance Fewer arteries Decreased angiogenesis Lower surface area Abnormal vasoreactivity Cardiovascular: Right and left heart hypertrophy and dysfunction Prominent systemic-to-pulmonary collateral vessels (some large) LUNG DEVELOPMENT - STAGES http://www.embryology.ch/anglais/rrespiratory/phasen07.html
LUNG DEVELOPMENT - STAGES Seaborn et al., Vol21, Issue 12 December 2010, Pages 729 738 ALVEOLAR GROWTH AND PULMONARY CAPILLARITY IN NEONATAL LUNG INJURY IN RATS Exposed to 95%O 2 PND 1-14 Dams rotated Studied P14 or P21 P14 Van Haaften et. al., Am. J. Respir. Crit. Care. Med; 2009 vol. 180 no. 11 1131-1142
ISOLATION AND DIFFERENTIATION OF BONE MARROW STROMAL CELL CULTURES AND EXPERIMENTAL DESIGN Aslam et. al., Am. J. Respir. Crit. Care. Med; 2009 vol. 180 no. 11 1122-1130 TREATMENT WITH CONDITIONED MEDIA OF BMSC, NOT PASMC, PREVENTED ALVEOLAR LOSS Aslam et. al., Am. J. Respir. Crit. Care. Med; 2009 vol. 180 no. 11 1122-1130
BMSC TREATMENT MODESTLY IMPROVED THE VOLUME DENSITY OF ALVEOLAR WALL TISSUE IN HYPEROXIA-TREATED MICE Aslam et. al., Am. J. Respir. Crit. Care. Med; 2009 vol. 180 no. 11 1122-1130 MOUSE GENETIC MODEL OF BRONCHOPULMONARY DYSPLASIA
FGF SIGNALING IS REDUCED IN BPD LUNG Benjamin et al., 2007. FGFR3;FGFR4 MUTANTS SHOW SIMPLIFIED ALVEOLI P5 P8 Fgfr3-;Fgfr4- Control
ETV MUTANT LUNGS EXHIBIT SIMPLIFIED ALVEOLI John Herriges MOUSE MODEL OF ACUTE LUNG INJURY AND SUBSEQUENT FIBROSIS Omentum Stromal Cell IP Delivery
BLEOMYCIN 2: INTRATRACHEAL INSTILLATION OF BLEOMYCIN INDUCES INFLAMMATION AND FIBROSIS Cell number x 10-3 1800 1600 1400 1200 1000 800 600 400 200 0 Interstitial inflammation Airway inflammation AIRWAY EPITHELIAL THICKNESS 50 μm Day 3 BAL Cytokines/Chemokines Blm Blm + OSC Sal Ctrl Day 3 * μm * Concentration (pg/ml) * * * IL-6 IL-12 G-CSF CCL-2 BLM BLM +OSC Sal Ctrl
PRELIMINARY RESULTS Airway inflammation Interstitial inflammation BAL Cell Number * Blm Blm + OSC Volume Density of Lesion * Day 7 Blm OSC EXPERIMENTAL SETUP Intraperitoneal injection of sterile polyacrylamide slurry BLM Instillation (0.04 U/mouse in 30 μl saline, 30G needle; Aerosolized with high pressure syringe) e) Surgical removal of omentum Prepare cell suspension OSC Transfer of purified cells 4x10 6 (Intraperitoneal injection) Analysis Bronchoalveolar Lavage Histology Airway Epithelium
HISTOLOGY OF OMENTUM AFTER BEAD INJECTION Day 1 Day 2 Day 3 MIGRATION OF IP INJECTED OSCS bleo 7 d ctrl Bleo Ctrl Lung
MOUSE GENETIC MODEL OF CONGENITAL DIAPHRAGMATIC HERNIA CONGENITAL DIAPHRAGMATIC HERNIA
CONGENITAL DIAPHRAGMATIC HERNIA CDH has an incidence of 1 in 2500 births Pulmonary hypoplasia and hypertension is a important clinical feature of CDH Persistent Pulmonary hypertension accounts for 95% mortalities inn CDH WHY DO CERTAIN PATIENTS WITH CDH HAVE PERSISTENT RESPIRATORY DISTRESS AND PULMONARY HYPERTENSION DESPITE SURGICAL CORRECTION OF THE DIAPHRAGMATIC HERNIA? Recent studies have focused on identifying genes that control diaphragm development These genes may play important roles in pulmonary and pulmonary vascular development A recent study identified Pbx1 as an important gene involved in diaphragm development (Russell et al, 2012) Do Pbx genes play an important role in pulmonary or pulmonary vascular development? Lung mesenchyme specific knockout of Pbx1
TBX4 CRE PBX CKO MICE HAVE HYPERTROPHIED RIGHT VENTRICLE AND RIGHT ATRIAL ENLARGEMENT AT P28 WT MPA LA CKO RA RA MPA LA R V LV R V LV Suggests obstruction to blood flow leaving the right heart, in the lungs, or returning to the left heart PBX MUTANT MICE HAVE HYPERTROPHIED RIGHT VENTRICLE AND RIGHT ATRIAL ENLARGEMENT AT P28 WT 14.7g RA LA RA CKO 10.3g L A RV LV RV P28 L V
LUNGS OF PBX MUTANT MICE ARE SIMPLIFIED AT P10 WT H&E CKO H&E P10 WT 10x H&E P10 CKO 10x H&E P10 10x P10 10x