Recombinant human Clara cell secretory protein treatment increases lung mRNA expression of surfactant proteins and vascular endothelial growth factor in a premature lamb model of respiratory distress syndrome.

Infant respiratory distress syndrome (IRDS) can lead to impaired alveolarization and dysmorphic vascularization of bronchopulmonary dysplasia. Clara cell secretory protein (CC10) has anti-inflammatory properties but is deficient in the premature infant. Because surfactant and vascular endothelial growth factor (VEGF) profiles are impaired by inflammation and CC10 inhibits lung inflammation, we hypothesized that CC10 may up-regulate surfactant protein (SP) and VEGF expression. Preterm lambs ( N = 24; 126 +/- 3 days [standard error] gestation) with IRDS were randomized to receive 100 mg/kg surfactant, 100 mg/kg surfactant followed by intratracheal 0.5, 1.5, or 5 mg/kg rhCC10 and studied for 4 hours. Gas exchange and lung mechanics were monitored; surfactant protein and VEGF mRNA profiles in lung were assessed. There was a significant rhCC10 dose-dependent increase in respiratory compliance and ventilation efficiency index; both parameters were significantly greater in animals treated with 5 mg/kg rhCC10 than those treated with surfactant alone. Similarly, there was a significant rhCC10 dose and protein-dependent increase in surfactant protein (SP-B > SP-C > SP-A) and dose- and isoform-dependent increase in VEGF (VEGF189 > VEGF165 > VEGF121). These data demonstrate that early intervention with rhCC10 up-regulates surfactant protein and VEGF expression, supporting the role of CC10 to protect against hyperoxia and mechanical ventilation in the immature lung.

Effects of recombinant Clara cell secretory protein (rhCC10) on inflammatory-related matrix metalloproteinase activity in a preterm lamb model of neonatal respiratory distress.

OBJECTIVE: To test the hypothesis that recombinant Clara cell secretory protein (rhCC10) instillation would foster improved lung function, acute structural preservation, and attenuation of matrix metalloproteinase (MMP) activity in a surfactant-deficient, mechanically ventilated lung. DESIGN: Interventional laboratory study. SETTING: An academic medical research facility in the northeastern United States. SUBJECTS: Sedated, ventilated premature lambs. INTERVENTIONS: Preterm lambs (n = 18; 126 +/- 3 days gestation) were instrumented, ventilated, and treated with 100 mg/kg exogenous surfactant. Lambs were randomized to receive 0, 0.5, or 5.0 mg/kg rhCC10 (n = 6 per group) and were ventilated for 4 hrs. MEASUREMENTS AND MAIN RESULTS: Posttreatment, lung function and cardiopulmonary stability were monitored for the ventilation period and then animals were killed for in vitro surfactant function analysis, lung histomorphometry, and analysis of MMP-2, -7, and -9 as well as their tissue inhibitors (TIMP)-1 and -2. Ventilation efficiency and pulmonary compliance were improved in the 5.0-mg/kg rhCC10 group by 4 hrs. Lung expansion was variable in the apical regions only. MMP-2 quantity was greater in the apical than the base lung regions of rhCC10-treated groups, and rhCC10 decreased MMP-7 in the base of the lung. CONCLUSIONS: These data suggest that improved lung function in the surfactant-treated preterm lamb following intratracheal rhCC10 may be related to the reduction of proteolytic activity of MMP-7.

Effects of an intratracheally delivered anti-inflammatory protein (rhCC10) on physiological and lung structural indices in a juvenile model of acute lung injury.

BACKGROUND: Mechanical ventilation results in acute lung trauma that can stimulate processes that alter lung development. Activation of matrix metalloproteinases (MMPs) and their tissue-produced inhibitors (TIMPs) is initiated by the inflammatory response to mechanical ventilation and are involved in breakdown of the basement membrane and parenchymal modeling. OBJECTIVES: The aim of this study was to test the hypothesis that rhCC10, a lung anti-inflammatory mediator, would foster improved lung function, structural preservation, and a reduction in net MMP activity in a juvenile model of acute lung injury. METHODS: Twenty-four juvenile rabbits were saline-lavage-injured and treated with 100 or 25 mg/kg surfactant (Survanta, Ross Labs) with or without rhCC10 (Claragen, Inc.; n=6 per group). Animals were ventilated for 4 h, then euthanized for in vitro surfactant function analysis, lung histomorphometry, and analysis of MMP-2, MMP-7, and MMP-9 and TIMPs 1 and 2 in the lung. RESULTS: Apical lung expansion, reduced with the lower dose of surfactant, was partially restored with the addition of rhCC10. Alveolar septal wall thickness was reduced (p<0.05) with low-dose surfactant plus rhCC10 compared to high-dose surfactant alone. Increased within-group variance in MMP-2 and MMP-9 proteolytic activity was found with the low-dose surfactant and was abolished with rhCC10. MMP-7 was reduced (p<0.05) with rhCC10 administration, independent of surfactant dose. CONCLUSIONS: Intratracheal administration of the anti-inflammatory rhCC10 resulted in preserved lung structure and MMP/TIMP profile after 4 h of mechanical ventilation, in a surfactant dose-dependent manner.

Recombinant human Clara cell secretory protein in acute lung injury of the rabbit: effect of route of administration.

OBJECTIVE: To test the hypothesis that intratracheal instillation of Clara cell secretory protein (CC 10) to the lung may afford greater protection than intravenous administration from ventilator-induced lung inflammation. DESIGN: Interventional laboratory study. SETTING: An academic medical research facility in northeastern United States. SUBJECTS: Sedated, lavage-injured juvenile rabbits. INTERVENTIONS: A total of 18 juvenile rabbits were anesthetized, ventilated, injured with saline lavage (Pao2 of <100 mm Hg; respiratory compliance of <0.50 mL.cm H2O.kg and <50% baseline), and randomized to receive intratracheally administered surfactant plus no recombinant human CC 10 (rhCC 10, control), intravenous rhCC 10, or intratracheal rhCC 10. MEASUREMENT AND MAIN RESULTS: Arterial blood chemistry and pulmonary mechanics were monitored; plasma and urine were collected serially. After 4 hrs of ventilation, lungs were lavaged and harvested. Surfactant function was analyzed from bronchoalveolar lavage samples (surfactometry); rhCC 10, interleukin-8, and lung myeloperoxidase concentrations were measured. Pao2, oxygenation index, ventilatory efficiency index, and respiratory compliance were not different across time or group beyond injury. Surfactometry data identified no differences as a function of group or time. Plasma, bronchoalveolar lavage, and lung interleukin-8 concentrations, lung myeloperoxidase concentrations, and inflammatory cell counts in the alveolar and interstitial spaces of intravenous and intratracheal groups were lower than in the control group (p < .05) but not statistically different from each other. Concentrations of rhCC 10 in lung, bronchoalveolar lavage, and plasma were greater in the intratracheal group than in the intravenous group (p<.05). Urine rhCC 10 concentrations were greater for the intravenous group than for the intratracheal group (p<.05) at 1, 3, and 4 hrs after treatment. No group differences in histomorphometry were noted. CONCLUSIONS: Both intravenous and intratracheal rhCC 10 delivery, after surfactant therapy, effectively decrease lung inflammation vs. surfactant alone. While supporting the physiologic profile, intratracheal instillation results in greater, maintained lung and plasma rhCC 10 pools compared with intravenous administration. As such, intratracheal instillation of rhCC 10 may afford more prolonged protection against lung inflammation than intravenous administration.

Dose response to rhCC10-augmented surfactant therapy in a lamb model of infant respiratory distress syndrome: physiological, inflammatory, and kinetic profiles.

While surfactant (SF) therapy alone improves respiratory distress syndrome (RDS)-associated gas exchange and lung stability, absence of anti-inflammatory proteins limits efficacy with respect to inflammation. Clara cell secretory protein (CC10), deficient in preterm infants, prevents SF degradation and has anti-inflammatory properties. In this study, intratracheal recombinant human (rh) CC10 (Claragen)-augmented SF (Survanta, Ross) therapy was examined in a premature lamb model of RDS with respect to inflammation and kinetic dose-response profiles. Preterm lambs (n = 24; gestational age: 126 +/- 3 days) were delivered via cesarean section, sedated, ventilated, and randomized into groups: 100 mg/kg SF, 100 mg/kg SF followed by 0.5 mg/kg rhCC10, 100 mg/kg SF followed by 1.5 mg/kg rhCC10, and 100 mg/kg SF followed by 5.0 mg/kg rhCC10. Arterial blood chemistry and lung mechanics were monitored; lungs were lavaged and snap-frozen after 4 h. TNF-alpha, IL-8 in plasma; TNF-alpha, IL-6, IL-8, myeloperoxidase in lung; and rhCC10 in plasma, urine, bronchoalveolar lavage, and lung were analyzed. Improvement in compliance, peak inspiratory pressure, and ventilatory efficiency index were greatest (P < 0.05) with SF + 5.0 mg/kg rhCC10. Plasma, urine, bronchoalveolar lavage, and lung [rhCC10] (where brackets denote concentration) increased (P < 0.01) with dose. Plasma [IL-8] was lower (P < 0.05) with rhCC10 than SF alone. Treatment with at least 1.5 mg/kg rhCC10 resulted in lower (P < 0.05) lung [TNF-alpha], [IL-8], and [myeloperoxidase]; SF + 1.5 mg/kg rhCC10 group had lower (P < 0.05) lung [IL-6], compared with all other groups. Compared with SF alone, SF augmented with at least 1.5 mg/kg rhCC10 decreased RDS-induced lung and systemic inflammation. Given that inflammation may lead to functional compromise, these data suggest that early intervention with rhCC10 may enhance SF therapy and warrant longer duration studies to determine its role to decrease long-term complications of ventilator management.

Differential impact of perfluorochemical physical properties on the physiologic, histologic, and inflammatory profile in acute lung injury.

OBJECTIVE: To evaluate the differential effects of physical properties of combinational perfluorochemical liquids (PFC) during partial liquid ventilation (PLV) on inflammatory indexes in the injured lung. DESIGN: : Interventional laboratory study. SETTING: Academic medical research laboratory. SUBJECTS: Seventeen saline lavage-injured juvenile rabbits. INTERVENTIONS: Rabbits were anesthetized, ventilated, saline lavage-injured, and randomized into groups: group 1 (conventional mechanical ventilation alone-no PFC), group 2 (PLV: lowest viscosity, highest vapor pressure), group 3 (PLV: mid-viscosity, mid-vapor pressure), group 4 (PLV: highest viscosity, lowest vapor pressure). MEASUREMENTS AND MAIN RESULTS: Arterial blood chemistry and pulmonary mechanics were monitored throughout the protocol. Following 4 hrs, lung tissue was harvested for interleukin-8, myeloperoxidase, and histologic analyses. Oxygenation (Pao2), ventilation (ventilation efficiency index), and respiratory compliance were not significantly different between groups before or following injury. Pao2 increased significantly following treatment in groups 3 and 4. Oxygenation index was significantly lower and respiratory compliance and ventilation efficiency index were significantly higher for group 4 following 4 hrs than all other groups. Total lung tissue interleukin-8 was significantly lower in groups 3 and 4 than groups 1 and 2, and lung myeloperoxidase was significantly lower in all PLV-treated groups than CMV alone. Histologic examination showed increased recruitment of the dependent lung in groups 3 and 4, with significantly greater lung expansion index, than groups 1 and 2. CONCLUSIONS: PLV, with a single dose of higher viscosity and lower vapor pressure PFC, resulted in significantly improved gas exchange and lung mechanics with significant reduction in lung inflammation compared with conventional mechanical ventilation alone and PLV with lower viscosity and higher vapor pressure liquid. Since PFC evaporative loss and redistribution are minimized by lower VP and higher viscosity, these data suggest that greater mechanoprotection and cytoprotection of the lung are conferred during PLV with PFC liquids that remain distributed throughout the entire lung for a longer duration.