Safety and efficacy of intratracheal recombinant human Clara cell protein in a newborn piglet model of acute lung injury

CC16 augmentation reduces exaggerated COPD-like disease in Cc16-deficient mice

Low Club Cell 16 kDa protein (CC16) plasma levels are linked to accelerated lung function decline in patients with chronic obstructive pulmonary disease (COPD). Cigarette smoke-exposed (CS-exposed) Cc16-/- mice have exaggerated COPD-like disease associated with increased NF-κB activation in their lungs. It is unclear whether CC16 augmentation can reverse exaggerated COPD in CS-exposed Cc16-/- mice and whether increased NF-κB activation contributes to the exaggerated COPD in CS-exposed Cc16-/- lungs. CS-exposed WT and Cc16-/- mice were treated with recombinant human CC16 (rhCC16) or an NF-κB inhibitor versus vehicle beginning at the midpoint of the exposures. COPD-like disease and NF-κB activation were measured in the lungs. RhCC16 limited the progression of emphysema, small airway fibrosis, and chronic bronchitis-like disease in WT and Cc16-/- mice partly by reducing pulmonary inflammation (reducing myeloid leukocytes and/or increasing regulatory T and/or B cells) and alveolar septal cell apoptosis, reducing NF-κB activation in CS-exposed Cc16-/- lungs, and rescuing the reduced Foxj1 expression in CS-exposed Cc16-/- lungs. IMD0354 treatment reduced exaggerated lung inflammation and rescued the reduced Foxj1 expression in CS-exposed Cc16-/- mice. RhCC16 treatment reduced NF-κB activation in luciferase reporter A549 cells. Thus, rhCC16 treatment limits COPD progression in CS-exposed Cc16-/- mice partly by inhibiting NF-κB activation and represents a potentially novel therapeutic approach for COPD.

Club Cell Secretory Protein in Lung Disease: Emerging Concepts and Potential Therapeutics

Club cell secretory protein (CCSP), also known as secretoglobin 1A1 (gene name SCGB1A1), is one of the most abundant proteins in the lung, primarily produced by club cells of the distal airway epithelium. At baseline, CCSP is found in large concentrations in lung fluid specimens and can also be detected in the blood and urine. Obstructive lung diseases are generally associated with reduced CCSP levels, thought to be due to decreased CCSP production or club cell depletion. Conversely, several restrictive lung diseases have been found to have increased CCSP levels both in the lung and in the circulation, likely related to club cell dysregulation as well as increasedlung permeability. Recent studies demonstrate multiple mechanisms by which CCSP dampens acute and chronic lung inflammation. Given these anti-inflammatory effects, CCSP represents a novel potential therapeutic modality in lung disease.

The administration of a pre-digested fat-enriched formula prevents necrotising enterocolitis-induced lung injury in mice

Necrotising enterocolitis (NEC) is a devastating gastrointestinal disease of prematurity that typically develops after the administration of infant formula, suggesting a link between nutritional components and disease development. One of the most significant complications that develops in patients with NEC is severe lung injury. We have previously shown that the administration of a nutritional formula that is enriched in pre-digested Triacylglyceride that do not require lipase action can significantly reduce the severity of NEC in a mouse model. We now hypothesise that this 'pre-digested fat (PDF) system' may reduce NEC-associated lung injury. In support of this hypothesis, we now show that rearing newborn mice on a nutritional formula based on the 'PDF system' promotes lung development, as evidenced by increased tight junctions and surfactant protein expression. Mice that were administered this 'PDF system' were significantly less vulnerable to the development of NEC-induced lung inflammation, and the administration of the 'PDF system' conferred lung protection. In seeking to define the mechanisms involved, the administration of the 'PDF system' significantly enhanced lung maturation and reduced the production of reactive oxygen species (ROS). These findings suggest that the PDF system protects the development of NEC-induced lung injury through effects on lung maturation and reduced ROS in the lung and also increases lung maturation in non-NEC mice.

Club Cell Protein, CC10, Attenuates Acute Respiratory Distress Syndrome Induced by Smoke Inhalation

OBJECTIVES

To evaluate the dose effects of Recombinant human Club cell 10-kDa protein (rhCC10) on lung function in a well-characterized ovine model of acute respiratory distress syndrome (ARDS) induced by smoke inhalation injury (SII); specifically, the potential of rhCC10 protein to control the inflammatory response and protect pulmonary tissue and function following SII.

DESIGN

Randomized, controlled, prospective, and large animal translational studies.

SETTING

University large animal intensive care unit.

SUBJECTS

Thirty-six adult female sheep were surgically prepared and allocated into five groups (Sham (no SII), n = 6; 1 mg/kg/d CC10, n = 8; 3 mg/kg/d CC10, n = 7; 10 mg/kg/d CC10, n = 8; Control SII, n = 7).

INTERVENTIONS

All groups except the sham group were subjected to SII with cooled cotton smoke. Then, the animals were placed on a ventilator, treated with 1, 3, and 10 mg/kg/d of intravenous rhCC10 or vehicle, divided evenly into two administrations per day every 12 h, fluid resuscitated, and monitored for 48 h in a conscious state.

MEASUREMENTS AND MAIN RESULTS

The group treated with 10 mg/kg/d rhCC10 attenuated changes in the following variables: PaO2/FiO2 ratio, oxygenation index, and peak inspiratory pressure; neutrophil content in the airway and myeloperoxidase levels; obstruction of the large and small airways; systemic leakage of fluid and proteins, and pulmonary edema.

CONCLUSIONS

In this study, high-dose rhCC10 significantly attenuated ARDS progression and lung dysfunction and significantly reduced systemic extravasation of fluid and proteins, normalizing fluid balance. Based on these results, rhCC10 may be considered a novel therapeutic option for the treatment of SII-induced ARDS.

CC16 Binding to α4β1 Integrin Protects against Mycoplasma pneumoniae Infection

Rationale CC16 (club cell secretory protein) is a pneumoprotein produced predominantly by pulmonary club cells. Circulating CC16 is associated with protection from the inception and progression of the two most common obstructive lung diseases (asthma and chronic obstructive pulmonary disease). Objectives Although exact mechanisms remain elusive, studies consistently suggest a causal role of CC16 in mediating antiinflammatory and antioxidant functions in the lung. We sought to determine any novel receptor systems that could participate in CC16's role in obstructive lung diseases. Methods Protein alignment of CC16 across species led to the discovery of a highly conserved sequence of amino acids, leucine-valine-aspartic acid (LVD), a known integrin-binding motif. Recombinant CC16 was generated with and without the putative integrin-binding site. A Mycoplasma pneumoniae mouse model and a fluorescent cellular adhesion assay were used to determine the impact of the LVD site regarding CC16 function during live infection and on cellular adhesion during inflammatory conditions. Measurements and Main Results CC16 bound to integrin α₄β₁), also known as the adhesion molecule VLA-4 (very late antigen 4), dependent on the presence of the LVD integrin-binding motif. During infection, recombinant CC16 rescued lung function parameters both when administered to the lung and intravenously but only when the LVD integrin-binding site was intact; likewise, neutrophil recruitment during infection and leukocyte adhesion were both impacted by the loss of the LVD site. Conclusions We discovered a novel receptor for CC16, VLA-4, which has important mechanistic implications for the role of CC16 in circulation as well as in the lung compartment.

Recombinant CC16 inhibits NLRP3/caspase-1-induced pyroptosis through p38 MAPK and ERK signaling pathways in the brain of a neonatal rat model with sepsis

BACKGROUND

Sepsis is a critical disease associated with extremely high mortality. Some severe forms of sepsis can induce brain injury, thus causing behavioral and cognitive dysfunction. Pyroptosis is a type of cell death that differs from apoptosis and plays an important role in the occurrence and development of infectious diseases, nervous system-related diseases. A recent study has found that there is pyroptosis in the hippocampus of sepsis-induced brain injury, but its mechanism and treatment scheme have not been evaluated.

METHODS

We established immediately a septic rat model by cecal ligation and perforation (CLP) after administration with recombinant club cell protein (rCC16) and/or U46619 in different groups. The clinical performance, survival percentage, vital signs, and neurobehavioral scores were monitored at different time points. Cortical pathological changes were also examined. The expression of cortical nucleotide-binding domain leucine-rich repeat-containing pyrin domain-containing 3 (NLRP3), caspase-1, (p)-p38 mitogen-activated protein kinase (MAPK), and (p)-extracellular signal-related kinase (ERK) was detected by western blotting and immunofluorescence analysis. The levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha in the cortical supernatant were detected by enzyme-linked immunosorbent assay.

RESULTS

Compared with the sham group, the clinical performance, survival percentage, vital signs, and severe cortical pathological changes in the CLP group were worse; NLRP3, caspase-1, and inflammatory factor levels were increased; and phosphorylation of p38 MAPK and ERK was also increased. Meanwhile, multiple indicators were deteriorated further after administration of U46619 in CLP rats. The clinical performance of CLP rats, however, was better after rCC16 administration; cortical pathological changes were attenuated; and NLRP3, caspase-1, and inflammatory factor levels and the phosphorylation of signaling pathway proteins (p38 MAPK and ERK) were reduced. Interestingly, the CLP rats showed the opposite changes in all indicators after administration with both rCC16 and U46619 when compared with those administered rCC16 alone.

CONCLUSIONS

In sepsis, rCC16 inhibits cortical pyroptosis through p38 MAPK and ERK signaling pathways. Meanwhile, rCC16 has a protective effect on newborn rats with sepsis, but it is not clear whether its mechanism is directly related to pyroptosis.

An Unsettled Promise: The Newborn Piglet Model of Neonatal Acute Respiratory Distress Syndrome (NARDS). Physiologic Data and Systematic Review

Despite great advances in mechanical ventilation and surfactant administration for the newborn infant with life-threatening respiratory failure no specific therapies are currently established to tackle major pro-inflammatory pathways. The susceptibility of the newborn infant with neonatal acute respiratory distress syndrome (NARDS) to exogenous surfactant is linked with a suppression of most of the immunologic responses by the innate immune system, however, additional corticosteroids applied in any severe pediatric lung disease with inflammatory background do not reduce morbidity or mortality and may even cause harm. Thus, the neonatal piglet model of acute lung injury serves as an excellent model to study respiratory failure and is the preferred animal model for reasons of availability, body size, similarities of porcine and human lung, robustness, and costs. In addition, similarities to the human toll-like receptor 4, the existence of intraalveolar macrophages, the sensitivity to lipopolysaccharide, and the production of nitric oxide make the piglet indispensable in anti-inflammatory research. Here we present the physiologic and immunologic data of newborn piglets from three trials involving acute lung injury secondary to repeated airway lavage (and others), mechanical ventilation, and a specific anti-inflammatory intervention via the intratracheal route using surfactant as a carrier substance. The physiologic data from many organ systems of the newborn piglet—but with preference on the lung—are presented here differentiating between baseline data from the uninjured piglet, the impact of acute lung injury on various parameters (24 h), and the follow up data after 72 h of mechanical ventilation. Data from the control group and the intervention groups are listed separately or combined. A systematic review of the newborn piglet meconium aspiration model and the repeated airway lavage model is finally presented. While many studies assessed lung injury scores, leukocyte infiltration, and protein/cytokine concentrations in bronchoalveolar fluid, a systematic approach to tackle major upstream pro-inflammatory pathways of the innate immune system is still in the fledgling stages. For the sake of newborn infants with life-threatening NARDS the newborn piglet model still is an unsettled promise offering many options to conquer neonatal physiology/immunology and to establish potent treatment modalities.

Recombinant CC16 regulates inflammation, oxidative stress, apoptosis and autophagy via the inhibition of the p38MAPK signaling pathway in the brain of neonatal rats with sepsis

Sepsis has a high in clinic neonatal mortality. Moreover, a considerable number of children's brains remain affected even after the treatment of sepsis and it often leaves sequelae. Therefore, early intervention for sepsis is of considerable significance. Recent studies have shown that Club cell protein (CC16) is closely related to the p38 mitogen-activated protein kinase (MAPK) signaling pathway, which can regulate inflammation, oxidative stress, apoptosis, and autophagy during sepsis. Thus, we analyzed the neuroprotective effect of recombinant CC16 (rCC16) in a neonatal sepsis rat model. For the first time, we found that the p38MAPK signaling pathway was activated in neonatal brain tissue of rats with sepsis, and the CC16 levels decreased significantly. Secondly, after the rCC16 interference, the occurrence of inflammation, oxidative stress and apoptosis were subsequently reversed, and autophagy was further stimulated. Finally, through further intervention using the p38MAPK signaling pathway inhibitor, SB203580, or its agonist, anisomycin, we confirmed that rCC16 reduced rat mortality and improve general conditions. Simultaneously, it had also neuroprotective effect. Its mechanism could be related to oxidative stress, inflammation, and apoptosis reduced and autophagy activated by rCC16 inhibiting the p38MAPK signaling pathway. Taken together, these findings provide insight into the pathogenesis, prevention, and treatment of sepsis via the activity of rCC16.

The role of recombinant human CC10 in the prevention of chronic pulmonary insufficiency of prematurity

BACKGROUND

Preterm neonates can develop chronic pulmonary insufficiency of prematurity (CPIP) later in infancy. Recombinant human CC10 protein (rhCC10) is an anti-inflammatory agent that could potentially prevent CPIP.

METHODS

The safety and efficacy of a single intratracheal dose of rhCC10 in reducing CPIP at 12 months corrected gestational age (CGA) was evaluated in a Phase II double-blind, randomized, placebo-controlled, multisite clinical trial. Eighty-eight neonates were randomized: 22 to placebo and 22 to 1.5 mg/kg rhCC10 in the first cohort and 21 to placebo and 23 to 5 mg/kg rhCC10 in the second cohort. Neonates were followed to 12 months CGA.

RESULTS

With CPIP defined as signs/symptoms, medical visits, hospital readmissions, and use of medications for respiratory complications at 12 months CGA, no significant differences were observed between rhCC10 or placebo groups. Only 5% of neonates had no evidence of CPIP at 12 months CGA.

CONCLUSIONS

A single dose of rhCC10 was not effective in reducing CPIP at 12 CGA. Since most neonates had evidence of CPIP using these exploratory endpoints, it is essential to develop more robust outcome measures for clinical trials of respiratory medications in high-risk premature neonates.

Bronchopulmonary Dysplasia: An Update of Current Pharmacologic Therapies and New Approaches

Bronchopulmonary dysplasia (BPD) remains the most prevalent long-term morbidity of surviving extremely preterm infants and is associated with significant health care utilization in infancy and beyond. Recent advances in neonatal care have resulted in improved survival of extremely low birth weight (ELBW) infants; however, the incidence of BPD has not been substantially impacted by novel interventions in this vulnerable population. The multifactorial cause of BPD requires a multi-pronged approach for prevention and treatment. New approaches in assisted ventilation, optimal nutrition, and pharmacologic interventions are currently being evaluated. The focus of this review is the current state of the evidence for pharmacotherapy in BPD. Promising future approaches in need of further study will also be reviewed.

Modulators of inflammation in Bronchopulmonary Dysplasia

Over 50 years after its first description, Bronchopulmonary Dysplasia (BPD) remains a devastating pulmonary complication in preterm infants with respiratory failure and develops in 30-50% of infants less than 1000-gram birth weight. It is thought to involve ventilator- and oxygen-induced damage to an immature lung that results in an inflammatory response and ends in aberrant lung development with dysregulated angiogenesis and alveolarization. Significant morbidity and mortality are associated with this most common chronic lung disease of childhood. Thus, any therapies that decrease the incidence or severity of this condition would have significant impact on morbidity, mortality, human costs, and healthcare expenditure. It is clear that an inflammatory response and the elaboration of growth factors and cytokines are associated with the development of BPD. Numerous approaches to control the inflammatory process leading to the development of BPD have been attempted. This review will examine the anti-inflammatory approaches that are established or hold promise for the prevention or treatment of BPD.

Evaluation of Club Cell 10-kDa Protein (CC10) Levels in Full-Term Infants

BACKGROUND

The club cell 10-kDa protein (CC10) is a homeostatic protein that is produced in the lung, diffuses into the blood, and is then excreted into the urine and stool. CC10 is known to have anti-inflammatory properties and to have lower endogenous production in preterm infants.

OBJECTIVES

As recombinant human CC10 (rhCC10) is being studied in preterm infants to reduce lung injury, understanding CC10 levels in term infants with normal lungs is needed to establish appropriate target dosing ranges.

METHODS

Serum, urine, and stool samples were collected from 24 healthy full-term infants, and CC10 levels were measured. Levels in term infants were then compared to those in preterm infants who were examined in our previous studies.

RESULTS

The mean gestational age and birth weight of the term infants were 38.8 ±1.1 weeks and 3,257 ± 513 g, respectively. The mean gestational age of the preterm infants was 26.8 ± 1.4 weeks. The median serum [CC10] levels with minimum and maximum values in term infants (214.2 ng/mL [34.1, 428.1]) were >7-fold higher than in preterm infants (27.5 ng/mL [8.0, 760.0]; p < 0.05). A significant correlation was found between [CC10] in urine and stool as well as between gestational age and stool [CC10] (p < 0.05).

CONCLUSIONS

CC10 is detectable in serum, urine, and stool in healthy term infants, with levels significantly higher than in preterm infants. This provides important data for ongoing therapeutic intervention trials with rhCC10 in high-risk preterm infants.

Club cell 10-kDa protein attenuates airway mucus hypersecretion and inflammation

Bacterial lipopolysaccharide (LPS) and interleukin (IL)-13 increase mucus secretion and inflammatory cytokine production in normal human bronchial epithelial (NHBE) cells. We evaluated the effect of club cell 10-kDa protein (CC10), an anti-inflammatory protein produced by epithelial cells, on mucus secretion, cell morphology and inflammatory cytokine production.

NHBE cells were cultured at an air–liquid interface with CC10 or vehicle and exposed to LPS on day 14. Mucin MUC5AC, IL-8 and granulocyte-macrophage colony-stimulating factor were measured in cell supernatants. MUC5AC and IL-8 mRNA expression were measured by real-time PCR. Western blotting was used to evaluate nuclear factor (NF)-κB and extracellular signal-regulated kinase (ERK) activation. Cells were evaluated histologically. Additionally, NHBE cells were exposed to IL-13 and CC10 for 14 days, and secretion of the mucins MUC5AC and MUC5B was measured.

MUC5AC secretion stimulated either by LPS or by IL-13 was attenuated by CC10 at 20 ng·mL−1 (p<0.05). CC10 at 20 ng·mL−1 also attenuated IL-8 secretion (p<0.05). MUC5AC and IL-8 mRNA expression were also decreased by CC10 (p<0.05). CC10 attenuated phosphorylation of NF-κB (p<0.05) and ERK1/2 (p<0.05).

CC10 attenuates LPS-induced mucus secretion in airway cells, in part due to inhibition of NF-κB and ERK phosphorylation.

Preclinical evaluation of human secretoglobin 3A2 in mouse models of lung development and fibrosis

Secretoglobin (SCGB) 3A2 is a member of the SCGB gene superfamily of small secreted proteins, predominantly expressed in lung airways. We hypothesize that human SCGB3A2 may exhibit anti-inflammatory, growth factor, and antifibrotic activities and be of clinical utility. Recombinant human SCGB3A2 was expressed, purified, and biochemically characterized as a first step to its development as a therapeutic agent in clinical settings. Human SCGB3A2, as well as mouse SCGB3A2, readily formed a dimer in solution and exhibited novel phospholipase A2 inhibitory activity. This is the first demonstration of any quantitative biochemical measurement for the evaluation of SCGB3A2 protein. In the mouse as an experimental animal, human SCGB3A2 exhibited growth factor activity by promoting embryonic lung development in both ex vivo and in vivo systems and antifibrotic activity in the bleomycin-induced lung fibrosis model. The results suggested that human SCGB3A2 can function as a growth factor and an antifibrotic agent in humans. When SCGB3A2 was administered to pregnant female mice through the tail vein, the protein was detected in the dam's serum and lung, as well as the placenta, amniotic fluids, and embryonic lungs at 10 min postadministration, suggesting that SCGB3A2 readily crosses the placenta. The results warrant further development of recombinant SCGB3A2 as a therapeutic agent in treating patients suffering from lung diseases or preterm infants with respiratory distress.

An update on pharmacologic approaches to bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the most prevalent long-term morbidity in surviving extremely preterm infants and is linked to increased risk of reactive airways disease, pulmonary hypertension, post-neonatal mortality, and adverse neurodevelopmental outcomes. BPD affects approximately 20% of premature newborns, and up to 60% of premature infants born before completing 26 weeks of gestation. It is characterized by the need for assisted ventilation and/or supplemental oxygen at 36 weeks postmenstrual age. Approaches to prevention and treatment of BPD have evolved with improved understanding of its pathogenesis. This review will focus on recent advancements and detail current research in pharmacotherapy for BPD. The evidence for both current and potential future experimental therapies will be reviewed in detail. As our understanding of the complex and multifactorial pathophysiology of BPD changes, research into these current and future approaches must continue to evolve.

Secretory phospholipase A2 pathway in various types of lung injury in neonates and infants: a multicentre translational study

BACKGROUND

Secretory phospholipase A2 (sPLA2) is a group of enzymes involved in lung tissue inflammation and surfactant catabolism. sPLA2 plays a role in adults affected by acute lung injury and seems a promising therapeutic target. Preliminary data allow foreseeing the importance of such enzyme in some critical respiratory diseases in neonates and infants, as well. Our study aim is to clarify the role of sPLA2 and its modulators in the pathogenesis and clinical severity of hyaline membrane disease, infection related respiratory failure, meconium aspiration syndrome and acute respiratory distress syndrome. sPLA2 genes will also be sequenced and possible genetic involvement will be analysed.

METHODS/DESIGN

Multicentre, international, translational study, including several paediatric and neonatal intensive care units and one coordinating laboratory. Babies affected by the above mentioned conditions will be enrolled: broncho-alveolar lavage fluid, serum and whole blood will be obtained at definite time-points during the disease course. Several clinical, respiratory and outcome data will be recorded. Laboratory researchers who perform the bench part of the study will be blinded to the clinical data.

DISCUSSION

This study, thanks to its multicenter design, will clarify the role(s) of sPLA2 and its pathway in these diseases: sPLA2 might be the crossroad between inflammation and surfactant dysfunction. This may represent a crucial target for new anti-inflammatory therapies but also a novel approach to protect surfactant or spare it, improving alveolar stability, lung mechanics and gas exchange.

Polydatin up-regulates Clara cell secretory protein to suppress phospholipase A2 of lung induced by LPS in vivo and in vitro

Background

Lung injury induced by lipopolysaccharide (LPS) remains one of the leading causes of morbidity and mortality in children. The damage to membrane phospholipids leads to the collapse of the bronchial alveolar epithelial barrier during acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Phospholipase A₂ (PLA₂), a key enzyme in the hydrolysis of membrane phospholipids, plays an important traumatic role in pulmonary inflammation, and Clara cell secretory protein (CCSP) is an endogenous inhibitor of PLA₂. Our previous study showed that polydatin (PD), a monocrystalline extracted from a traditional Chinese medicinal herb (Polygonum cuspidatum Sieb, et Zucc), reduced PLA₂ activity and sPLA₂-IIA mRNA expression and mitigated LPS-induced lung injury. However, the potential mechanism for these effects has not been well defined. We have continued to investigate the effect of PD on LPS-induced expression of CCSP mRNA and protein in vivo and in vitro.

Results

Our results suggested that the CCSP mRNA level was consistent with its protein expression. CCSP expression was decreased in lung after LPS challenge. In contrast, PD markedly increased CCSP expression in a concentration-dependent manner. In particular, CCSP expression in PD-pretreated rat lung was higher than in rats receiving only PD treatment.

Conclusion

These results indicated that up-regulation of CCSP expression causing inhibition of PLA₂ activation may be one of the crucial protective mechanisms of PD in LPS-induced lung injury.

Intratracheal Clara cell secretory protein (CCSP) administration in preterm infants with or at risk of respiratory distress syndrome

BACKGROUND

Clara cell secretary protein (CCSP) is an immune-modulating and anti-inflammatory agent. CCSP is available synthetically as recombinant human Clara cell protein (rhCC10). It has been shown in animal models to reduce lung injury, improve pulmonary compliance and oxygenation, decrease systemic inflammation and up-regulate surfactant protein and vascular endothelial growth factor expression. These properties makes intratracheally administered CCSP a potential agent in prevention of chronic lung disease (CLD).

OBJECTIVES

To determine the effect of intratracheal CCSP administration compared to placebo or no treatment on morbidity and mortality in preterm infants with or at risk of respiratory distress syndrome (RDS).

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library, October 2010), MEDLINE and PREMEDLINE (1950 to October 2010), EMBASE (1980 to October 2010) and CINAHL (1982 to October 2010). We searched proceedings of scientific meetings, Google Scholar and reference lists of identified studies, and contacted expert informants and surfactant manufacturers.

SELECTION CRITERIA

Published, unpublished and ongoing randomised controlled, cluster-randomised or quasi-randomised trials of intratracheal CCSP administration, compared to placebo or no treatment on morbidity and mortality in preterm infants at risk of RDS.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for eligibility and quality, and extracted data.

MAIN RESULTS

One pilot study was identified and included. This study enrolled 22 preterm infants 700 to 1300g with established RDS who required ventilation for surfactant administration. Infants received one intratracheal dose of placebo (n = 7), 1.5 mg/kg (n = 8) or 5 mg/kg (n = 7) rhCC10 within four hours of surfactant treatment. At either dose of rhCC10, no significant difference was reported in CLD (36 weeks postmenstrual age or 28 days), mortality, intraventricular haemorrhage, periventricular leukomalacia, patent ductus arteriosus, necrotising enterocolitis, sepsis or days supplemental oxygen compared to placebo. A significant increase in days mechanical ventilation was reported for infants receiving rhCC10 5mg/kg (mean difference 12.00, 95% confidence interval 0.39 to 23.61) but not at the lower dose. The study reported that a single intratracheal dose of rhCC10 was well tolerated and resulted in a significant reduction in tracheal aspirate neutrophil and total cell count, and lung protein concentration. There was no significant difference reported in tracheal aspirate cytokine levels between groups.

AUTHORS' CONCLUSIONS

There are insufficient data to determine the role of rhCC10 in clinical practice. Further studies are required to determine if rhCC10 reduces lung inflammation in infants at risk of CLD, and to determine dose and dosing strategy.

Clara cell secretory protein increases phagocytic and decreases oxidative activity of neutrophils

Horses suffer from recurrent airway obstruction, an asthma-like condition induced by repeat inhalation of environmental substances present in barn air. Clara cell secretory protein (CCSP) is much reduced during active inflammation when neutrophils predominate in the airways, and in chronic asthmatics. We sought to investigate morphologic and functional interactions of CCSP with neutrophils. Bronchoalveolar and blood neutrophils from healthy control animals, and from animals with recurrent airway obstruction in remission and exacerbation, were evaluated by immuno-cytochemistry and immuno-electron microscopy for presence of CCSP. Blood neutrophil oxidative burst and phagocytic activities were determined in the presence of different concentrations of recombinant equine CCSP. Bronchoalveolar lavage neutrophils from horses with exacerbated lung inflammation, but not from control horses, and not blood neutrophils from either group of animal, contained abundant immunoreactive CCSP. On immuno-electron microscopy, CCSP localized to the cytoplasm and nucleus. Incubation of blood neutrophils with CCSP significantly reduced oxidative burst activity (P<0.0001) and increased phagocytosis (P<0.001) of neutrophils. These findings indicate that CCSP enters neutrophils in horses with active neutrophilic lung inflammation and alters the function of neutrophils in blood. Presence in the nucleus suggests a potential transcriptional role of CCSP in neutrophils.

Clara cell secretory protein is reduced in equine recurrent airway obstruction

Horses are prone to recurrent airway obstruction (RAO), an inflammatory lung disease induced by repeated exposure to environmental mold, dust, and bacterial components. Active disease manifests with mucus hyperproduction, neutrophilic inflammation, bronchoconstriction, and coughing. Chronically affected animals have lung remodeling characterized by smooth muscle hyperplasia, collagen deposition, lymphoid hyperplasia, and impaired aerobic performance. Clara cell secretory protein (CCSP) counters inflammation in the lung, hence we hypothesized that CCSP depletion is a key feature of RAO in horses. Recombinant equine CCSP and specific antiserum were produced, and percutaneous lung biopsies were obtained from 3 healthy horses and from 3 RAO-affected horses before and after induction of RAO. CCSP relative gene expression in tissue, as well as protein concentration in lung lavage fluid, was determined. Immunocytochemical analysis, using both light and immunogold ultrastructural methods, demonstrated reduced CCSP staining in lung tissue of animals with RAO. Immunogold label in Clara cell granules was less in animals with chronic RAO than in normal animals, and absent in animals that had active disease. Median lung lavage CCSP concentration was 132 and 129 ng/ml in healthy horses, and 62 and 24 ng/ml in RAO horses before and after challenge, respectively. CCSP lung gene expression was significantly higher in healthy animals than in animals with chronic RAO. Together, these preliminary findings suggest that reduced production of CCSP and subcellular changes in Clara cells are features of chronic environmentally induced lung inflammation in horses.

Effects of Clara cell 10 (CC10) protein on symptoms and signs of allergic rhinitis

BACKGROUND

The Clara cell 10 (CC10) protein is produced by the airway epithelium. Reduced levels of CC10 are associated with allergic rhinitis and asthma. In experimental models, treatment with the CC10 protein may reduce features of airway inflammation.

OBJECTIVES

To examine whether or not topical treatment with recombinant human CC10 (rhCC10) affects symptoms and signs of allergic rhinitis in a pollen season model.

METHODS

Out of the pollen season, patients with allergic rhinitis received treatment with rhCC10, 0.56 mg per nasal cavity, once daily for 7 days in a double-blinded, placebo-controlled, crossover design. During this period, individualized allergen challenges were given once daily. Symptoms and peak nasal inspiratory flow (PNIF) were recorded daily in the morning, 10 minutes after challenge, and in the evening. Mean recordings of the last 3 days of the challenge series were used in the analysis. Nasal lavages were performed at the end of each challenge period, and eosinophil cationic protein, myeloperoxidase, and alpha2-macroglobulin levels were measured as indices of eosinophil and neutrophil activity and plasma exudation, respectively.

RESULTS

Recombinant human CC10 did not affect allergen-induced morning, postchallenge, or evening symptoms compared with placebo. Morning, postchallenge, and evening PNIF were not improved by rhCC10. No statistically significant differences were observed between rhCC10 and placebo for any of the lavage fluid indices.

CONCLUSIONS

Repeated nasal administrations of rhCC10 protein, in the present dose, do not exert antiallergic effects in seasonal allergic rhinitis.

Cord blood Clara cell protein CC16 predicts the development of bronchopulmonary dysplasia

Clara cell protein (CC16) is an anti-inflammatory protein and a biomarker of pulmonary epithelial cells and alveolocapillary membrane injury in adults. We investigated whether low cord blood concentrations of CC16 are associated with the development of respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) in preterm infants and the relationship between CC16 and its pro-inflammatory counterpart, the secretory phospholipase A(2) (sPLA(2)) enzyme. CC16 concentration, sPLA(2) activity and IL-6 concentration were measured in cord blood plasma from 79 preterm infants (25 controls, 37 infants who developed RDS and 17 infants who developed BPD). After adjustment for gestational age and Apgar score at 5 min, the CC16 concentration was lower in BPD infants than in preterm controls (p<0.01). sPLA(2) activity was similar in all groups and the IL-6 concentrations were increased in both RDS and BPD infants (p<0.01 and p<0.05, respectively, vs. controls). We conclude that low cord blood CC16 concentrations in preterm infants independently predict the development of BPD. Low CC16 levels may reflect early lung injury, which contributes to the severity of RDS and progress towards BPD. Future studies are needed to assess whether the early administration of recombinant human CC16 in preterm infants with low cord blood CC16 prevents the development of BPD.

Higher levels of the anti-inflammatory protein CC10 are associated with improvement in bronchial dysplasia and sputum cytometric assessment in individuals at high risk for lung cancer

PURPOSE

CC10, a 10-kDa anti-inflammatory protein secreted by bronchiolar Clara cells, is infrequently expressed in non-small cell lung cancer and its overexpression in non-small cell lung cancer cell lines results in a less malignant phenotype. Several lines of evidence have shown that bronchial dysplasia and sputum atypia are predictors of lung cancer. We investigated whether changes in CC10 expression correlate with regression of bronchial dysplasia and/or improvement in sputum abnormalities as measured by image cytometry.

EXPERIMENTAL DESIGN

High-risk smokers enrolled in a chemoprevention trial underwent serial bronchoscopies with biopsies and bronchoalveolar lavage (BAL) collection, sputum assessment by image cytometry, and blood collection. CC10 was measured by competitive ELISA in BAL and plasma. Logistic regression analyses were done to determine the associations between CC10 levels and the improvement in bronchial dysplasia and sputum cytometric assessment.

RESULTS

The net change in the BAL CC10 levels in subjects with improved bronchial lesions or improved sputum cytometry assessment was significantly higher than in those without improvement (P < 0.05). The odds ratio (95% confidence interval) associated with 1-unit increase in CC10 was 2.72 (1.31-5.64) for regression of dysplastic lesions and 2.94 (1.22-7.05) for improvement in sputum cytometry assessment after multivariate adjustment. Plasma CC10 was not significantly associated with either outcome.

CONCLUSIONS

Higher BAL CC10 levels are significantly correlated with regression of bronchial dysplasia and improvement in sputum cytometry assessment in smokers with high lung cancer risk. Whether CC10 levels can predict clinical outcomes among high-risk populations warrants further investigation.

Uteroglobin: a steroid-inducible immunomodulatory protein that founded the Secretoglobin superfamily

Blastokinin or uteroglobin (UG) is a steroid-inducible, evolutionarily conserved, secreted protein that has been extensively studied from the standpoint of its structure and molecular biology. However, the physiological function(s) of UG still remains elusive. Isolated from the uterus of rabbits during early pregnancy, UG is the founding member of a growing superfamily of proteins called Secretoglobin (Scgb). Numerous studies demonstrated that UG is a multifunctional protein with antiinflammatory/ immunomodulatory properties. It inhibits soluble phospholipase A(2) activity and binds and perhaps sequesters hydrophobic ligands such as progesterone, retinols, polychlorinated biphenyls, phospholipids, and prostaglandins. In addition to its antiinflammatory activities, UG manifests antichemotactic, antiallergic, antitumorigenic, and embryonic growth-stimulatory activities. The tissue-specific expression of the UG gene is regulated by several steroid hormones, although a nonsteroid hormone, prolactin, further augments its expression in the uterus. The mucosal epithelia of virtually all organs that communicate with the external environment express UG, and it is present in the blood, urine, and other body fluids. Although the physiological functions of this protein are still under investigation, a single nucleotide polymorphism in the UG gene appears to be associated with several inflammatory/autoimmune diseases. Investigations with UG-knockout mice revealed that the absence of this protein leads to phenotypes that suggest its critical homeostatic role(s) against oxidative damage, inflammation, autoimmunity, and cancer. Recent studies on UG-binding proteins (receptors) provide further insight into the multifunctional nature of this protein. Based on its antiinflammatory and antiallergic properties, UG is a potential drug target.

CC10 reduces inflammation in meconium aspiration syndrome in newborn piglets

Complications from meconium aspiration syndrome (MAS) remain significant despite a variety of therapeutic interventions. Clara cell protein (CC10) is a novel anti-inflammatory agent that can also inhibit phospholipase A2 (PLA2) (an important component of meconium). The present study examined whether administration of recombinant human CC10 (rhCC10) would reduce inflammation and improve lung function in a piglet model of MAS. Following meconium instillation, piglets exhibited significant physiologic dysfunction that improved significantly after surfactant administration. Analysis of tracheal aspirates revealed significant increases in both tumor necrosis factor (TNF) alpha and interleukin (IL)-8 after meconium instillation. rhCC10-treated animals had significantly lower TNF-alpha levels at 24 h (561 +/- 321 versus 1357 +/- 675 pg/mL, p < 0.05) compared with saline controls. There were no differences between rhCC10-treated and untreated groups with respect to other measured physiologic variables or inflammatory markers, including secretory PLA2 activity. Histologic analyses revealed marked inflammatory infiltrates and thickened alveolar walls, but no significant differences among rhCC10 and control animals. Newborn piglets with MAS have significant physiologic dysfunction, marked inflammatory changes and histologic abnormalities, which was partially counteracted by a single dose of exogenous surfactant and rhCC10.

The association between the anti-inflammatory protein CC10 and smoking status among participants in a chemoprevention trial

CC10, the secretory product of bronchiolar Clara cells, is infrequently expressed in non-small cell lung cancer (NSCLC), and its overexpression in NSCLC cell lines results in a less malignant phenotype. CC10 levels in bronchoalveolar lavage fluid (BAL) and serum are significantly lower in current smokers than healthy nonsmokers, but the effect of long-term smoking cessation on CC10 is unknown. We measured CC10 in baseline BAL and plasma collected from current (n = 81) and former (n = 23) smokers participating in a chemoprevention trial. Former smokers had significantly higher plasma CC10 levels compared with current smokers [mean, 62.1 ng/mL (95% CI, 43.0-81.2); range, 23.0-175.0 ng/mL for former smokers; and mean, 37.1 ng/mL (95% CI, 29.8-44.4); range, 5.0-171.0 ng/mL for current smokers; P < 0.001]. BAL CC10 levels also trended in the same direction. A significant positive correlation was found between CC10 plasma and BAL levels. After adjustment for age, sex, and pack-years of cigarette consumption, former smokers had 1.70 (95% CI, 1.23-2.36) times higher plasma CC10 levels than current smokers (P < 0.01), whereas former smokers also had nonsignificantly higher baseline BAL CC10 levels compared with current smokers [adjusted mean ratio (95% CI), 1.60 (0.92-2.80), P = 0.094 and 1.35 (0.86-2.10), P = 0.193 for the absolute and normalized BAL CC10, respectively]. These results show that sustained smoking cessation is associated with higher plasma CC10 levels, suggesting that at least some of the damage associated with tobacco smoke may be repaired by long-term smoking cessation.

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.

The influence of gestation and mechanical ventilation on serum clara cell secretory protein (CC10) concentrations in ventilated and nonventilated newborn infants

Clara cell secretory protein (CC10) is an important anti-inflammatory mediator in the adult lung, but its role in newborn pulmonary protection is uncertain. We examined the early postnatal behavior of CC10 in newborn serum and tracheal fluid and hypothesized that CC10 production is positively influenced by gestation. Blood from 165 infants from the first, third/fourth, and seventh days of life (gestational ages: 23-29 wk, 30-36 wk, >36 wk) and tracheal fluid (TF) from the first day of life from 32 ventilated infants were analyzed for CC10. Surfactant proteins A (SPA) and B (SPB) were also analyzed from the blood of a subgroup of infants. Serum CC10 on day 1 was highest in term infants (69.4 ng/mL), followed by moderately preterm (55.8 ng/mL), and then extremely preterm infants (median 42.1 ng/mL). Term infants also had higher tracheal fluid CC10 than preterm infants. (20.152 ng/mL versus 882 ng/mL). Mechanical ventilation increased serum CC10 only in moderately preterm infants, and only on d 1 [68.4 ng/mL versus 42.1 ng/mL (nonventilated moderately preterm infants)]. Serum CC10 decreased progressively by the end of the first week in all infants, in contrast to SPA and SPB, which increased. Our results show that CC10 is detectable in the blood of newborn infants and that a production surge occurs at birth. This surge is more pronounced in term infants and may confer them with superior extrauterine pulmonary protection compared with preterm infants.

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.

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.

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.

The safety, pharmacokinetics, and anti-inflammatory effects of intratracheal recombinant human Clara cell protein in premature infants with respiratory distress syndrome

Clara cell 10-kD protein (CC10) is a potent anti-inflammatory protein that is normally abundant in the respiratory tract. CC10 is deficient and oxidized in premature infants with poor clinical outcome (death or the development of bronchopulmonary dysplasia). The safety, pharmacokinetics, and anti-inflammatory activity of recombinant human CC10 (rhCC10) were evaluated in a randomized, placebo-controlled, double-blinded, multicenter trial in premature infants with respiratory distress syndrome. A total of 22 infants (mean birth weight: 932 g; gestational age: 26.9 wk) received one intratracheal dose of placebo (n = 7) or 1.5 mg/kg (n = 8) or 5 mg/kg (n = 7) rhCC10 within 4 h of surfactant treatment. Pharmacokinetic analyses demonstrated that the serum half-life was 11.6 (1.5 mg/kg group) and 9.9 h (5 mg/kg group). Excess circulating CC10 was eliminated via the urine within 48 h. rhCC10-treated infants showed significant reductions in total cell count (p < 0.0002), neutrophil counts (p < 0.001), and total protein concentrations (p < 0.01) and tended to have decreased IL-6 (p < 0.07) in tracheal aspirate fluid collected over the first 3 d of life. Infants in all three groups showed comparable growth. At 36 wk postmenstrual age, five of seven infants were still hospitalized and two of seven infants were receiving oxygen in the placebo group compared with two of seven hospitalized and one of seven receiving oxygen in the 1.5-mg/kg group and four of six hospitalized and three of six receiving oxygen in the 5-mg/kg group. A single intratracheal dose of rhCC10 was well tolerated and had significant anti-inflammatory effects in the lung. Multiple doses of rhCC10 will be investigated for efficacy in reducing pulmonary inflammation and ameliorating bronchopulmonary dysplasia in future studies.