Naphthalene as a model to study repair processes of the murine tracheal epithelium in vivo

Background: Application of the chondrogenic transforming growth factor beta (TGF-β) is an attractive approach to enhance the intrinsic biological activities in damaged articular cartilage, especially when using direct gene transfer strategies based on the clinically relevant recombinant adeno-associated viral (rAAV) vectors. Purpose: To evaluate the ability of an rAAV–TGF-β construct to modulate the early repair processes in sites of focal cartilage injury in minipigs in vivo relative to control (reporter lacZ gene) vector treatment. Study Design: Controlled laboratory study. Methods: Direct administration of the candidate rAAV–human TGF-β (hTGF-β) vector was performed in osteochondral defects created in the knee joint of adult minipigs for macroscopic, histological, immunohistochemical, histomorphometric, and micro–computed tomography analyses after 4 weeks relative to control (rAAV- lacZ) gene transfer. Results: Successful overexpression of TGF-β via rAAV at this time point and in the conditions applied here triggered the cellular and metabolic activities within the lesions relative to lacZ gene transfer but, at the same time, led to a noticeable production of type I and X collagen without further buildup on the subchondral bone. Conclusion: Gene therapy via direct, local rAAV–hTGF-β injection stimulates the early reparative activities in focal cartilage lesions in vivo. Clinical Relevance: Local delivery of therapeutic (TGF-β) rAAV vectors in focal defects may provide new, off-the-shelf treatments for cartilage repair in patients in the near future.

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In vivo differentiation potential of tracheal basal cells: evidence for multipotent and unipotent subpopulations

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00155.2003 ◽

2004 ◽

Vol 286 (4) ◽

pp. L643-L649 ◽

Cited By ~ 195

Author(s):

Kyung U. Hong ◽

Susan D. Reynolds ◽

Simon Watkins ◽

Elaine Fuchs ◽

Barry R. Stripp

Keyword(s):

Progenitor Cells ◽

Progenitor Cell ◽

Tracheal Epithelium ◽

Secretory Cells ◽

Basal Cells ◽

Cell Type ◽

Cell Hyperplasia ◽

Differentiation Potential ◽

Airway Injury

The composition of the conducting airway epithelium varies significantly along the proximal to distal axis, with that of the tracheal epithelium exhibiting the greatest complexity. A number of progenitor cells have been proposed to contribute to the maintenance of this cellular diversity both in the steady state and in response to injury. However, individual roles for each progenitor cell type are poorly defined in vivo. The present study was undertaken to investigate the hypothesis that basal cells represent a multipotent progenitor cell type for renewal of the injured tracheal epithelium. To understand their contribution to epithelial repair, mice were exposed to naphthalene to induce airway injury and depletion of the secretory cell progenitor pool. Injury resulted in a rapid induction of cytokeratin 14 (K14) expression among the majority of GSI-B4-reactive cells and associated hyperplasia of basal cells. Restoration of depleted secretory cells occurred after 6 days of recovery and was associated with regression of the basal cell hyperplasia, suggesting a progenitor-progeny relationship. Multipotent differentiation of basal cells was confirmed using a bitransgenic ligand-regulated Cre-loxP reporter approach in which expression of a ubiquitously expressed LacZ reporter was activated within K14-expressing progenitor cells during airway repair. With the use of this approach, it was determined that K14-expressing cells include subsets capable of either multipotent or unipotent differentiation in vivo. We conclude that basal cells have the capacity for restoration of a fully differentiated epithelium.

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Effects of amphotericin B on ion and fluid movement across dog tracheal epithelium

Journal of Applied Physiology ◽

10.1152/jappl.1983.55.4.1257 ◽

1983 ◽

Vol 55 (4) ◽

pp. 1257-1261 ◽

Cited By ~ 15

Author(s):

I. Nathanson ◽

J. H. Widdicombe ◽

J. A. Nadel

Keyword(s):

Amphotericin B ◽

Short Circuit ◽

Open Circuit ◽

Tracheal Epithelium ◽

Fluid Movement ◽

Ussing Chambers ◽

Cl Secretion ◽

Special Apparatus ◽

Net Fluxes

Ion fluxes or fluid flow were measured across sheets of dog tracheal epithelium mounted in Ussing chambers or a special apparatus, respectively. Under short-circuit conditions, luminal amphotericin B (3 X 10(-5) M) caused an inhibition of net Cl secretion and an increase in net Na absorption across paired tissues. In paired tissues under resting open-circuit conditions, there was no significant net transepithelial flux of either Cl or Na. Amphotericin B induced significant net fluxes of both Cl and Na toward the serosal side. In separate tissues from the same animals, there was no significant transepithelial fluid movement under resting conditions. Amphotericin B caused a net absorption of fluid. The absorption of salt and fluid in amphotericin B-treated tissues was abolished by ouabain. We conclude that stimulation of active Na transport by amphotericin B leads to fluid absorption. In vivo, the movement of fluid across the dog tracheal epithelium may be dependent on a balance between active Cl secretion and active Na absorption.

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Ultrastructural studies of hamster tracheal epithelium in vivo and in vitro

Journal of Ultrastructure Research ◽

10.1016/s0022-5320(80)90023-4 ◽

1980 ◽

Vol 70 (1) ◽

pp. 70-81 ◽

Cited By ~ 9

Author(s):

Johnny L. Carson ◽

Albert M. Collier ◽

Shih-Chin S. Hu

Keyword(s):

Tracheal Epithelium ◽

Ultrastructural Studies

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Vitamin A deficiency and inflammation: the pivotal role of secretory cells in the development of atrophic, hyperplastic and metaplastic change in the tracheal epithelium in vivo

Virchows Archiv B Cell Pathology Including Molecular Pathology ◽

10.1007/bf02890441 ◽

1992 ◽

Vol 61 (1) ◽

pp. 375-387 ◽

Cited By ~ 8

Author(s):

Xin-min Zhang ◽

Elizabeth M. McDowell

Keyword(s):

Vitamin A ◽

Vitamin A Deficiency ◽

Pivotal Role ◽

Tracheal Epithelium ◽

Secretory Cells

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Evidence of K+ channel function in epithelial cell migration, proliferation, and repair

AJP Cell Physiology ◽

10.1152/ajpcell.00226.2013 ◽

2014 ◽

Vol 306 (4) ◽

pp. C307-C319 ◽

Cited By ~ 15

Author(s):

Alban Girault ◽

Emmanuelle Brochiero

Keyword(s):

Cell Migration ◽

K Channel ◽

Epithelial Tissue ◽

Physical Interaction ◽

Epithelial Repair ◽

Repair Processes ◽

Proliferation And Differentiation ◽

Intracellular Ca ◽

Cell Migration And Proliferation

Efficient repair of epithelial tissue, which is frequently exposed to insults, is necessary to maintain its functional integrity. It is therefore necessary to better understand the biological and molecular determinants of tissue regeneration and to develop new strategies to promote epithelial repair. Interestingly, a growing body of evidence indicates that many members of the large and widely expressed family of K+ channels are involved in regulation of cell migration and proliferation, key processes of epithelial repair. First, we briefly summarize the complex mechanisms, including cell migration, proliferation, and differentiation, engaged after epithelial injury. We then present evidence implicating K+ channels in the regulation of these key repair processes. We also describe the mechanisms whereby K+ channels may control epithelial repair processes. In particular, changes in membrane potential, K+ concentration, cell volume, intracellular Ca2+, and signaling pathways following modulation of K+ channel activity, as well as physical interaction of K+ channels with the cytoskeleton or integrins are presented. Finally, we discuss the challenges to efficient, specific, and safe targeting of K+ channels for therapeutic applications to improve epithelial repair in vivo.

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