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Principal Investigator: Tien Peng
Organization: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
Fiscal Year: 2024
Award: $545,713
Funding agency: National Heart Lung and Blood Institute
Project Summary/Abstract
Aging is one of the biggest risk factors for many chronic lung diseases, including idiopathic pulmonary fibrosis
(IPF). However, uncertainties remain as to how age-related processes contribute to the pathogenesis of IPF,
particularly in deciphering the cell types that might play a role in both aging and fibrotic transformation.
Senescence, a cellular state characterized by an irreversible cell cycle arrest and other morphologic
transformations, is thought to be a cellular phenotype that becomes increasingly prevalent in aged organs,
contributing to the decline in function over time. p16INK4A, a tumor suppressor, is one of the best-studied
biomarkers of senescent cells in vitro and in vivo. Numerous genetic models have been built to remove p16INK4A+
cells from tissues, demonstrating a functional role for these cells in promoting age-related pathologies such as
lung fibrosis. Despite the knowledge gained from strategies that remove p16INK4A+ cells, deletion of these cells
precludes the identification and functional characterization of p16INK4A+ cells in vivo, leaving a large gap in our
understanding of how senescent cells might behave in tissues rather than in a culture dish. To address this, we
constructed a novel genetic reporter of senescence by engineering an amplified fluorescent tag driven by
expression of p16INK4A (mouse referred to as INK4A H2B-GFP Reporter-In-Tandem, or INKBRITE) to isolate and
characterize p16INK4A+ cells in vivo and ex vivo. To our surprise, we were able to identify p16INK4A+ fibroblasts in
young and healthy lungs that contribute to scar-forming cells in areas of fibrotic remodeling. Furthermore,
p16INK4A+ cells are able to alter the epithelial progenitor microenvironment and alter stem cell regenerative
outcomes. This led us to the hypothesis that p16INK4A+ fibroblasts are capable of contributing to fibrosis by
forming scars and inducing an pathologic epithelial response, and the INKBRITE reporter could be leveraged as
a screening platform to identify compounds that more precisely target p16INK4A+ fibroblasts in vivo. Through the
use of single cell RNA sequencing, adoptive cell transfers, lineage tracing, high-content imaging, and various
methodologies outlined in this proposal, we aim to better define the cellular contribution of p16INK4A+ fibroblasts
to fibrotic transformation, and define agents that might better remove it from tissues.
Terms: <3-D><3-Dimensional><3D><Address><Adoptive Cell Transfers><Adoptive Transfer><Age related pathologies><Aging><Alveolus><Area><Assay><Bioassay><Biological Assay><Biological Markers><Biology><Body Tissues><Bronchial Alveolus><CDK4I><CDKN2><CDKN2 Genes><CDKN2A><CDKN2A gene><CMM2><Cell Body><Cell Cycle Arrest><Cell Isolation><Cell Line><Cell Segregation><Cell Separation><Cell Separation Technology><CellLine><Cells><Characteristics><Chemicals><Chronic lung disease><Cicatrix><Collagen><Cues><Cyclin-Dependent Kinase Inhibitor 2A Gene><Data><Disease><Disorder><Drug Screening><Elderly><Engineering><Epithelium><Exhibits><Fibroblasts><Fibrosing Alveolitis><Fibrosis><Fibrotic lesions in lung><Genetic><Genetic Models><High Throughput Assay><Human><INK4><INK4A><Image><In Vitro><Induction of Apoptosis><Inflammatory><Injury><Knowledge><Ligands><Lung><Lung Respiratory System><Lung Tissue Fibrosis><Lung damage><Lung scar><Lung tissue scar><MTS1><MTS1 Genes><Maintenance><Metaplasia><Metaplastic Change><Methodology><Mice><Mice Mammals><Modeling><Modern Man><Morphology><Murine><Mus><Oncogenesis><Organ><Organoids><Outcome><Pathogenesis><Pathologic><Phenotype><Physiologic><Physiological><Process><Progenitor Cells><Pulmonary Fibrosis><Pulmonary Scar><Pulmonary Tissue fibrosis><Regenerative response><Reporter><Reporting><Risk Factors><Role><Scarring at the lung><Scarring in the lung><Scars><Strains Cell Lines><TP16><TSG9A><Testing><Therapeutic><Time><Tissues><Traction><Transplantation><Tumor Suppressor Proteins><Uncertainty><Validation><Wound Repair><accelerated aging><accelerated biological age><accelerated biological aging><adoptive cell therapy><adoptive cellular therapy><advanced age><age acceleration><age associated><age associated disease><age associated disorder><age associated impairment><age associated pathologies><age correlated><age dependent><age dependent disease><age dependent disorder><age dependent impairment><age linked><age related><age related human disease><age specific><age-related disease><age-related disorder><age-related impairment><aged><bio-markers><biologic marker><biomarker><cell behavior><cell sorting><cell type><cellular behavior><chronic pulmonary disease><combinatorial><cultured cell line><decline in function><decline in functional status><defined contribution><diffuse interstitial pulmonary fibrosis><disease model><disorder model><doubt><epithelial progenitor><epithelial progenitor cell><epithelial stem cell><fibrosis in the lung><fibrotic lung><fibrotic lung disease><fibrotic pulmonary disease><functional decline><functional status decline><genetic approach><genetic strategy><geriatric><high throughput screening><idiopathic pulmonary fibrosis><imaging><in vivo><injuries><lung fibrosis><lung injury><migration><novel><p14ARF><p16 Genes><p16INK4 Genes><p16INK4A Genes><p16INK4a><progenitor><progenitor cell division><progenitor cell expansion><progenitor cell renewal><progenitor division><progenitor expansion><progenitor renewal><programs><prospective><pulmonary><pulmonary damage><pulmonary injury><pulmonary tissue damage><pulmonary tissue injury><rational design><regeneration response><regenerative cell><response><scRNA-seq><screening><screenings><senescence><senescent><senescent cell><senior citizen><senolytics><single cell RNA-seq><single cell RNAseq><single cell analysis><single cell expression profiling><single cell transcriptomic profiling><single-cell RNA sequencing><social role><stem and progenitor cell division><stem and progenitor cell expansion><stem and progenitor cell renewal><stem cell division><stem cell expansion><stem cell renewal><stem cells><therapeutic target><three dimensional><tool><transplant><tumor suppressor><tumorigenesis><validations><wound healing><wound recovery><wound resolution>