Identification of a bone marrow–derived epithelial-like population capable of repopulating injured mouse airway epithelium
Amy P. Wong, … , Jim Hu, Thomas K. Waddell
Amy P. Wong, … , Jim Hu, Thomas K. Waddell
Published January 26, 2009
Citation Information: J Clin Invest. 2009;119(2):336-348. https://doi.org/10.1172/JCI36882.
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Research Article Pulmonology

Identification of a bone marrow–derived epithelial-like population capable of repopulating injured mouse airway epithelium

Abstract

The bone marrow compartment is enriched in stem and progenitor cells, and an unidentified subpopulation of these cells can contribute to lung epithelial repair. Here we identify this subpopulation and quantitate its relative contribution to injured airway epithelium. A subpopulation of adherent human and murine bone marrow cells that expresses Clara cell secretory protein (CCSP) was identified using flow cytometry. When cultured at the air-liquid interface in ex vivo cultures, Ccsp+ cells expressed type I and type II alveolar markers as well as basal cell markers and active epithelial sodium channels. Ccsp+ cells preferentially homed to naphthalene-damaged airways when delivered transtracheally or intravenously, with the former being more efficient than the latter. Interestingly, naphthalene-induced lung damage transiently increased Ccsp expression in bone marrow and peripheral circulation. Furthermore, lethally irradiated Ccsp-null mice that received tagged wild-type bone marrow contained donor-derived epithelium in both normal and naphthalene-damaged airways. This study therefore identifies what we believe to be a newly discovered cell in the bone marrow that might have airway reconstitution potential in the context of cell-based therapies for lung disease. Additionally, these data could reconcile previous controversies regarding the contribution of bone marrow to lung regeneration.

Authors

Amy P. Wong, Armand Keating, Wei-Yang Lu, Pascal Duchesneau, Xinghua Wang, Adrian Sacher, Jim Hu, Thomas K. Waddell

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Figure 4

Regenerative potential of Ccsp+ BMCs.

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Regenerative potential of Ccsp+ BMCs. (A) Both transtracheal (TT) an...
(A) Both transtracheal (TT) and intravenous (IV) delivery of Ccsp+ or Ccsp– BMCs (red) after naphthalene-induced airway injury show greater airway retention of Ccsp+ cells than Ccsp– cells. Scale bars: 100 μm. Original magnification, ×20. Insets show a representative cell (scale bars: 20 μm; original magnification, ×120). (B) Of the 106 cells injected, transtracheal delivery of Ccsp+ cells showed the most cell retention (9%) measured 4 days after cell injection. n = 4 mice per group. *P < 0.01 compared with Ccsp– cells. (C) Ion channel genes Cftr and Enac and the tight junction protein E-cadherin were detected by real-time RT-PCR of Ccsp+ cells. Ccsp+ BMC levels of Cftr and Enac corresponded to 4% of the levels detected in airway epithelial cells, while E-cadherin levels corresponded to 8%. Low but detectable levels of Cftr (<1%) were also detected in Ccsp– cells. n = 12 mice per group. (D) Ccsp+ cells coexpressed Cftr (green) and Enac (red) proteins. Hoechst counterstain was used to visualize nuclei (blue). Scale bars: 10 μm. (E) Perforated patch clamp recordings show the total conductance in Ccsp+ cells was larger than in Ccsp– cells. Treating Ccsp– cells with glybenclamide and amiloride did not change their total conductance. Application of glybenclamide did not alter the total conductance of Ccsp+ cells, but amiloride significantly suppressed the total conductance, suggesting that Ccsp+ cells express functional Enac properties. n = 5 cells per group. *P < 0.01 compared with control.