Biology subjects

Varisco, B. M.

Publications and source records attributed to Varisco, B. M..

3 recordsLinked to original sources

bioRxiv2024

Inhibition of CELA1 Improves Septation in the Mouse Hyperoxia Model of Impaired Alveolar Development

A key feature of bronchopulmonary dysplasia (BPD) is impaired alveolar septation. In later live, BPD survivors are more susceptible to childhood respiratory problems and have reduced respiratory function as adults. Chymotrypsin-like elastase 1 (CELA1) is a serine protease expressed in AT2 cells that mediates emphysema progression in adult mouse models. CELA1 binds and cleaves tropoelastin in response to strain. Its expression is developmentally regulated. Using the mouse hyperoxia model of impaired alveolar development we hypothesized a role for CELA1 in impaired alveolar development (IAD). In C57BL6 mouse pup lungs exposed to 80% oxygen for 14 days Cela1 mRNA increased 1.9-fold (p<0.05) and protein 2.6-fold (p<0.01). Protein levels normalized after 14 days in room air. Analysis of an existing single cell mRNA-seq dataset showed Cela1 mRNA in AT2 cells, alveolar macrophages and interstitial macrophages. The fraction of cells with Cela1 mRNA increased with hyperoxia. By flow cytometry the only Cela1-specific difference in immune cell populations was a 2-fold increase in lung eosinophils in room air (p<0.05). After 14 days of exposure to 80% oxygen Cela1-/- mice had better alveolarization with an average mean linear intercept of 80 m compared to 111m (p<0.001). Treatment of hyperoxia-exposed pups with subcutaneous anti-Cela1 KF4 antibody offered similar protection compared to IgG (59 m vs. 67 m, p<0.001).Human BPD specimens demonstrated CELA1 in AT2 cells and myeloid cells. These data indicate that hyperoxia-induced increases in CELA1 are partially responsible for IAD and suggest a potential role in premature neonates exposed to high FiO2.

developmental biology↗

bioRxiv2024

KF4 anti-CELA1 Antibody and Purified α1-Antitrypsin Have Similar but Not Additive Efficacy in Preventing Emphysema in Murine α1-Antitrypsin Deficiency

Alpha-1 antitrypsin (AAT) deficiency is the most common genetic cause of emphysema. Chymotrypsin-like Elastase 1 (CELA1) is a serine protease neutralized by AAT and is important in emphysema progression. Cela1-deficiency is protective in a murine models of AAT-deficient emphysema. KF4 anti-CELA1 antibody prevented emphysema in PPE and cigarette smoke models in wild type mice. We evaluated potential toxicities of KF4 and its ability to prevent emphysema in AAT deficiency. We found Cela1 protein expression in mouse lung, pancreas, small intestine, and spleen. In toxicity studies, mice treated with KF4 25 mg/kg weekly for four weeks showed an elevation in blood urea nitrogen and slower weight gain compared to lower doses or equivalent dose IgG. In histologic grading of tissue injury of the lung, kidney, liver, and heart, there was some evidence of liver injury with KF4 25 mg/kg, but in all tissues, injury was less than in control mice subjected to cecal ligation and puncture. In efficacy studies, KF4 doses as low as 0.5 mg/kg reduced the lung elastase activity of AAT-/-mice treated with 0.2 units of PPE. In this injury model, AAT-/-mice treated with KF4 1 mg/kg weekly, human purified AAT 60 mg/kg weekly, and combined KF4 and AAT treatment had less emphysema than mice treated with IgG 1 mg/kg weekly. However, the efficacy of KF4, AAT, or KF4 & AAT was similar. While KF4 might be an alternative to AAT replacement, combined KF4 and AAT replacement does not confer additional benefit.

pathology↗

bioRxiv2017

Role Of Chymotrypsin-Like Elastase 1 In Lung Physiology And in α1-Antitrypsin Deficiency

1-antitrypsin (AAT) deficiency-related emphysema is the fourth leading indication for lung transplantation. We previously demonstrated that AAT covalently neutralizes chymotrypsin-like elastase 1 (Cela1) in vitro, that Cela1 is expressed during the alveolar stage of lung development in association with regions of lung elastin remodeling, and that lung stretch increases Cela1 expression and binding to lung elastin. Here we show that Cela1 is exclusively responsible for stretch-inducible lung elastase activity, reduces postnatal lung elastance, and is required for emphysema in an antisense oligo model of AAT deficiency. Cela1 mRNA is present in the human lung, and in the placental mammal lineage, Cela1 is more conserved than Cela2 or Cela3 with unique promoter and protein elements indicating a unique role for Cela1 in this lineage. These data demonstrate an adaptive role for Cela1 in placental mammal lung biology with physiologic relevance to AAT-deficient lung disease in humans.

physiology↗