Research Paper Volume 16, Issue 13 pp 10694—10723

Modulating in vitro lung fibroblast activation via senolysis of senescent human alveolar epithelial cells

Joseph S. Spina1,2, , Tracy L. Carr3, , Lucy A. Phillips1, , Heather L. Knight1, , Nancy E. Crosbie1, , Sarah M. Lloyd3, , Manisha A. Jhala3, , Tony J. Lam3, , Jozsef Karman1,4, , Meghan E. Clements1, , Tovah A. Day2, , Justin D. Crane2,5, , William J. Housley1, ,

  • 1 AbbVie Bioresearch Center, Worcester, MA 01605, USA
  • 2 Department of Biology, Northeastern University, Boston, MA 02115, USA
  • 3 AbbVie Inc., North Chicago, IL 60064, USA
  • 4 Current address: Merck, Cambridge, MA 02141, USA
  • 5 Current address: Pfizer Inc., Cambridge, MA 02139, USA

Received: August 19, 2023       Accepted: April 18, 2024       Published: June 29, 2024
How to Cite

Copyright: © 2024 Spina et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Idiopathic pulmonary fibrosis (IPF) is an age-related disease with poor prognosis and limited therapeutic options. Activation of lung fibroblasts and differentiation to myofibroblasts are the principal effectors of disease pathology, but damage and senescence of alveolar epithelial cells, specifically type II (ATII) cells, has recently been identified as a potential trigger event for the progressive disease cycle. Targeting ATII senescence and the senescence-associated secretory phenotype (SASP) is an attractive therapeutic strategy; however, translatable primary human cell models that enable mechanistic studies and drug development are lacking. Here, we describe a novel system of conditioned medium (CM) transfer from bleomycin-induced senescent primary alveolar epithelial cells (AEC) onto normal human lung fibroblasts (NHLF) that demonstrates an enhanced fibrotic transcriptional and secretory phenotype compared to non-senescent AEC CM treatment or direct bleomycin damage of the NHLFs. In this system, the bleomycin-treated AECs exhibit classical hallmarks of cellular senescence, including SASP and a gene expression profile that resembles aberrant epithelial cells of the IPF lung. Fibroblast activation by CM transfer is attenuated by pre-treatment of senescent AECs with the senolytic Navitoclax and AD80, but not with the standard of care agent Nintedanib or senomorphic JAK-targeting drugs (e.g., ABT-317, ruxolitinib). This model provides a relevant human system for profiling novel senescence-targeting therapeutics for IPF drug development.


ADI: Alveolar differentiation intermediate; AEC: Alveolar epithelial cell; AF/Alexa-: Alexa Fluor; ATI/ATII: Alveolar epithelial cell type I/II; DATP: Damage-associated transient progenitor; CM: Conditioned medium; ECM: Extracellular matrix; EGF: Epidermal growth factor; ISH: In situ hybridization; IC50: 50% inhibitory concentration; IL: Interleukin; ILD: Interstitial lung disease; IPF: Idiopathic pulmonary fibrosis; JAK: Janus kinase; NHLF: Normal human lung fibroblast; MCP1: Monocyte chemoattractant protein 1; MMP: Matrix metalloproteinase; MSD: Meso Scale Discovery; PATS: Pre-alveolar type-1 transitional cell state; PBS/DPBS: Phosphate buffered saline/Dulbecco’s phosphate buffered saline; qPCR: quantitative real-time polymerase chain reaction; SADD: Senescence-associated differentiation disorder; SASP: Senescence-associated secretory phenotype; SSc-ILD: Systemic sclerosis-associated interstitial lung disease; TEER: Trans-epithelial Electrical Resistance; TGF-β: Transforming growth factor beta; TIMP1: Tissue inhibitor of metalloproteinase 1.