Developmental shift in the relative percentages of lung fibroblast subsets: role of apoptosis postseptation
| Autor: | Walid Al-Jumaily, Jennifer Strange, Feyisola Awonusonu, Margaret C. Bruce, Suseela Srinivasan |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Pulmonary and Respiratory Medicine
Aging Programmed cell death Pathology medicine.medical_specialty Physiology Apoptosis Biology Interstitial cell Flow cytometry Rats Sprague-Dawley chemistry.chemical_compound Fetus Physiology (medical) Oxazines medicine Animals RNA Messenger Fibroblast Lung Fluorescent Dyes medicine.diagnostic_test Nile red Cell Biology Fibroblasts Flow Cytometry Lipid Metabolism Molecular biology Extracellular Matrix Rats Fibronectin medicine.anatomical_structure Animals Newborn chemistry biology.protein Cell Division |
| Zdroj: | American Journal of Physiology-Lung Cellular and Molecular Physiology. 277:L848-L859 |
| ISSN: | 1522-1504 1040-0605 |
| DOI: | 10.1152/ajplung.1999.277.4.l848 |
| Popis: | We have used the lipophilic, fluorescent dye Nile red and flow cytometry to identify and isolate two rat lung fibroblast subsets, lipid-containing interstitial cells (LICs) and non-LICs (NLICs) and to quantitate developmental changes in the relative percentages of these subsets. A significant decrease was observed in the percentage of LICs (from 79.0 ± 3.8% on postnatal day 4 to 28.6 ± 4.2% on day 30; P < 0.0001). To determine whether one or both subsets undergo apoptosis postseptation, fibroblasts from 16- to 18-day rats were treated with BODIPY-conjugated dUTP to label DNA strand breaks, which were then quantitated by flow cytometry. Apoptotic cells were judged to be predominantly LICs based on flow cytometric estimates of cell size and granularity and on light-microscopic colocalization of intracellular lipid and Hoechst-positive apoptotic bodies. Cell proliferation was compared in LICs and NLICs with both an in vitro [3H]thymidine incorporation assay and cell cycle analysis of propidium iodide-stained cells. Results of both assays indicated that on days 4– 5, LICs proliferated more rapidly than NLICs. Tropoelastin and fibronectin mRNA expression, evaluated by RT-PCR, indicated that although tropoelastin mRNA levels did not differ, fibronectin mRNA levels were approximately ninefold greater in LICs. These results demonstrate the feasibility of a flow cytometric assay for the analysis of size, granularity, and intracellular lipid content of neonatal rat lung fibroblast subsets. Subsets differed substantially with respect to proliferative capacity, fibronectin mRNA expression, and incidence of apoptosis postseptation. Together with the observed changes in relative percentages of fibroblast subsets with age, these data suggest that the ratio of LICs to NLICs could be a critical determinant of fibroblast function during lung development. |
| Databáze: | OpenAIRE |
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