Keratinocyte Growth Factor Prevents Ventilator-induced Lung Injury in anEx VivoRat Model

Keratinocyte growth factor (KGF) is a potent mitogen that prevents lung epithelial injury in vivo. We hypothesized that KGF treatment reduces ventilator-induced lung injury by increasing the alveolar epithelial tolerance to mechanical strain. We evaluated the effects of in vivo KGF treatment to rats on the response of alveolar type II (ATII) cells to in vitro controlled, uniform deformation. KGF (5 mg/kg) or saline (no-treatment control) was instilled intratracheally in rats, and ATII cells were isolated 48 h later. After 24 h in culture, both cell groups were exposed to 1 h of continuous cyclic strain (25% change in surface area); undeformed wells were included as controls. Cytotoxicity was evaluated quantitatively with fluorescent immunocytochemistry. There was >1% cell death in undeformed KGF-treated and control groups. KGF pretreatment significantly reduced deformation-related cell mortality to only 2.2 ± 1.3% (SD) from 49 ± 5.5% in control wells ( P < 0.001). Effects of extracellular matrix, actin cytoskeleton, and phenotype of KGF-treated and control cells were examined. The large reduction in deformation-induced cell death demonstrates that KGF protects ATII cells by increasing their strain tolerance and supports KGF treatment as a potential preventative measure for ventilator-induced lung injury.

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Intratracheal Keratinocyte Growth Factor Enhances Surfactant Protein B Expression in Mechanically Ventilated Preterm Pigs

10.21203/rs.3.rs-112089/v2 ◽

2021 ◽

Author(s):

Ramesh Krishnan ◽

Esmond Arrindell ◽

Frank Caminita ◽

Jie Zhang ◽

Randal Buddington

Keyword(s):

Growth Factor ◽

Lung Injury ◽

Bronchopulmonary Dysplasia ◽

Epithelial To Mesenchymal Transition ◽

Keratinocyte Growth Factor ◽

Surfactant Protein ◽

Mesenchymal Transition ◽

Ventilator Induced Lung Injury ◽

Human Keratinocyte ◽

Surfactant Protein B

Abstract Background: Bronchopulmonary dysplasia is a devastating disease of the premature newborn with high morbidity and mortality. Surfactant deficient preterm lungs are susceptible to ventilator induced lung injury, thereby developing bronchopulmonary dysplasia. Despite surfactant therapy and newer ventilation strategies, associated morbidity and mortality remains unchanged. Enhancing surfactant production and reducing ventilator induced lung injury in premature infants are critical. Recombinant keratinocyte growth factor previously been studied to treat adult respiratory distress syndrome. We hypothesized that administering recombinant human keratinocyte growth factor when initiating mechanical ventilation would help stimulate type II cell proliferation and surfactant production. Recombinant human keratinocyte growth factor may also help mitigate ventilator induced lung injury hereby reducing epithelial to mesenchymal transition, a possible precursor to later development of bronchopulmonary dysplasia. Methods: To test our hypothesis, we delivered preterm pigs via cesarean section on day 102. We performed intubation and ventilation for 24 hr. using intermittent positive pressure ventilation. After ventilation began, pigs randomly received intratracheal recombinant human keratinocyte growth factor (20 µg/kg; n=6) or sham treatment (0.5 ml 0.9% saline; n= 6). We recorded physiology data and arterial blood gases during ventilation. After 24 hr. pigs were extubated and received oxygen via nasal cannulation 12 hr. before euthanasia to collect lungs for histopathology and immunohistochemistry. Immunohistochemistry staining was graded and analyzed for surfactant protein B and epithelial to mesenchymal transition markers. Data were analyzed using t-test and Fisher’s exact test. Continuous variables analyzed using ANOVA.Results: Compared with control pigs, recombinant human keratinocyte growth factor pretreated pigs had improved ventilation with higher tidal volumes and required less oxygen (FiO2) during mechanical ventilation for similar peak pressures demonstrating improved lung compliance. Recombinant human keratinocyte growth factor pretreated pig lungs showed increased surfactant protein B expression (p< 0.05) and significantly reduced TGF-β (p< 0.05), a prominent marker for epithelial to mesenchymal transition.Conclusions: Intratracheal recombinant human keratinocyte growth factor administered at initiation of mechanical ventilation enhances surfactant production, reduce lung injury by mitigation of the changes by epithelial mesenchymal transition, thereby improving outcomes. Thus, recombinant human keratinocyte growth factor may represent a potential therapeutic strategy to prevent bronchopulmonary dysplasia.

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Intratracheal Keratinocyte Growth Factor Enhances Surfactant Protein B Expression in Mechanically Ventilated Preterm Pigs

10.21203/rs.3.rs-112089/v1 ◽

2020 ◽

Author(s):

Ramesh Krishnan ◽

Esmond Arrindell ◽

Frank Caminita ◽

Jie Zhang ◽

Randal Buddington

Keyword(s):

Growth Factor ◽

Lung Injury ◽

Bronchopulmonary Dysplasia ◽

Epithelial To Mesenchymal Transition ◽

Keratinocyte Growth Factor ◽

Surfactant Protein ◽

Mesenchymal Transition ◽

Ventilator Induced Lung Injury ◽

Human Keratinocyte ◽

Surfactant Protein B

Abstract Background: Bronchopulmonary dysplasia is a devastating disease of the premature newborn with high morbidity and mortality. Surfactant deficient preterm lungs are susceptible to ventilator induced lung injury, thereby developing bronchopulmonary dysplasia. Despite surfactant therapy and newer ventilation strategies, associated morbidity and mortality remains unchanged. Enhancing surfactant production and reducing ventilator induced lung injury in premature infants are critical. Recombinant keratinocyte growth factor previously been studied to treat adult respiratory distress syndrome. We hypothesized that administering recombinant human keratinocyte growth factor when initiating mechanical ventilation would help stimulate type II cell proliferation and surfactant production. Recombinant human keratinocyte growth factor may also help mitigate ventilator induced lung injury hereby reducing epithelial to mesenchymal transition, a possible precursor to later development of bronchopulmonary dysplasia. Methods: To test our hypothesis, we delivered preterm pigs via cesarean section on day 102. We performed intubation and ventilation for 24 hr. using intermittent positive pressure ventilation. After ventilation began, pigs randomly received intratracheal recombinant human keratinocyte growth factor (20 μg/kg; n=6) or sham treatment (0.5 ml 0.9% saline; n= 6). We recorded physiology data and arterial blood gases during ventilation. After 24 hr. pigs were extubated and received oxygen via nasal cannulation 12 hr. before euthanasia to collect lungs for histopathology and immunohistochemistry. Immunohistochemistry staining was graded and analyzed for surfactant protein B and epithelial to mesenchymal transition markers. Data were analyzed using t-test and Fisher’s exact test. Continuous variables analyzed using ANOVA.Results: Compared with control pigs, recombinant human keratinocyte growth factor pretreated pigs had improved ventilation with higher tidal volumes and required less oxygen (FiO2) during mechanical ventilation for similar peak pressures demonstrating improved lung compliance. Recombinant human keratinocyte growth factor pretreated pig lungs showed increased surfactant protein B expression (p< 0.05) and significantly reduced TGF-β (p< 0.05), a prominent marker for epithelial to mesenchymal transition. Conclusions: Intratracheal recombinant human keratinocyte growth factor administered at initiation of mechanical ventilation enhances surfactant production, reduce lung injury by mitigation of the changes by epithelial mesenchymal transition, thereby improving outcomes. Thus, recombinant human keratinocyte growth factor may represent a potential therapeutic strategy to prevent bronchopulmonary dysplasia.

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