Assessment of ciliary phenotype in primary ciliary dyskinesia by micro-optical coherence tomography
George M. Solomon, Richard Francis, Kengyeh K. Chu, Susan E. Birket, George Gabriel, John E. Trombley, Kristi L. Lemke, Nikolai Klena, Brett Turner, Guillermo J. Tearney, Cecilia W. Lo, Steven M. Rowe
George M. Solomon, Richard Francis, Kengyeh K. Chu, Susan E. Birket, George Gabriel, John E. Trombley, Kristi L. Lemke, Nikolai Klena, Brett Turner, Guillermo J. Tearney, Cecilia W. Lo, Steven M. Rowe
View: Text | PDF
Research Article Pulmonology

Assessment of ciliary phenotype in primary ciliary dyskinesia by micro-optical coherence tomography

Abstract

Ciliary motion defects cause defective mucociliary transport (MCT) in primary ciliary dyskinesia (PCD). Current diagnostic tests do not assess how MCT is affected by perturbation of ciliary motion. In this study, we sought to use micro-optical coherence tomography (μOCT) to delineate the mechanistic basis of cilia motion defects of PCD genes by functional categorization of cilia motion. Tracheae from three PCD mouse models were analyzed using μOCT to characterize ciliary motion and measure MCT. We developed multiple measures of ciliary activity, integrated these measures, and quantified dyskinesia by the angular range of the cilia effective stroke (ARC). Ccdc39–/– mice, with a known severe PCD mutation of ciliary axonemal organization, had absent motile ciliary regions, resulting in abrogated MCT. In contrast, Dnah5–/– mice, with a missense mutation of the outer dynein arms, had reduced ciliary beat frequency (CBF) but preserved motile area and ciliary stroke, maintaining some MCT. Wdr69–/– PCD mice exhibited normal motile area and CBF and partially delayed MCT due to abnormalities of ciliary ARC. Visualization of ciliary motion using μOCT provides quantitative assessment of ciliary motion and MCT. Comprehensive ciliary motion investigation in situ classifies ciliary motion defects and quantifies their contribution to delayed mucociliary clearance.

Authors

George M. Solomon, Richard Francis, Kengyeh K. Chu, Susan E. Birket, George Gabriel, John E. Trombley, Kristi L. Lemke, Nikolai Klena, Brett Turner, Guillermo J. Tearney, Cecilia W. Lo, Steven M. Rowe

×

Figure 1

Representative schematic for methods of ciliary motion interrogation using μOCT.

Options: View larger image (or click on image) Download as PowerPoint
Representative schematic for methods of ciliary motion interrogation usi...
(A) Schematic of epithelial cell surfaces, demarcating ciliated areas (blue box) and cilia arcs (black dashed box), and the mucus layer, with mucus transport (red box, Muc, mucus layer; BM, basement membrane; epi, epithelial layer; MCT, mucociliary transport rate). (B) Actual μOCT of normal murine trachea (left). Coverage map of motile cilia areas in various CBFs, with the inset demonstrating that the percentage motile ciliated area is calculated by the ratio of active to inactive pixelated areas (right). (C) Representative cilia enlarged at full extent of cilia motion demonstrating ARC (θ). Periciliary layer (PCL) represents ciliary height. μOCT image (middle) of a cilia arc at full extension in the effective stroke and a tracing of the ciliary arc coordinates for calculation of ARC. (D) A schematic of the ciliary tip motion in the z-plane over time compared to an actual μOCT image of M-mode to determine CBF. Distance between z-plane spikes represents frequency of ciliary beat (CBF). (E) MCT is represented by the transport of particles over time across the transverse axis of the OCT beam (x).