Immunohistochemical analysis of rat and human respiratory cilia with anti-dynein antibody: comparison between normal cilia and pathological cilia in primary ciliary dyskinesia

[The respiratory mucociliary system and its exploration in primary ciliary dyskinesia]

BACKGROUND

We analyzed the main characteristic features of the respiratory epithelium mucociliary system and the different tests of ciliary beat and mucociliary transport (mucociliary clearance). This knowledge is necessary for an often interdisciplinary diagnosis and treatment of primary ciliary dyskinesia.

METHODS

Review of the literature and personal experience of the different tests of ciliary structure and function.

RESULTS

This disease is characterized by abnormalities in ciliary structure/function. The genetic mechanisms and the ultrastructural abnormalities that are involved are heterogenous compared to the relative homogeneity of the clinical presentation.

CONCLUSION

The diagnostic criteria are compatible clinical features (chronic upper airway and bronchopulmonary infections, situs inversus...) coupled with tests of ciliary structure and function.

Left-right asymmetry and kinesin superfamily protein KIF3A: new insights in determination of laterality and mesoderm induction by kif3A-/- mice analysis

KIF3A is a classical member of the kinesin superfamily proteins (KIFs), ubiquitously expressed although predominantly in neural tissues, and which forms a heterotrimeric KIF3 complex with KIF3B or KIF3C and an associated protein, KAP3. To elucidate the function of the kif3A gene in vivo, we made kif3A knockout mice. kif3A-/- embryos displayed severe developmental abnormalities characterized by neural tube degeneration and mesodermal and caudal dysgenesis and died during the midgestational period at approximately 10.5 dpc (days post coitum), possibly resulting from cardiovascular insufficiency. Whole mount in situ hybridization of Pax6 revealed a normal pattern while staining by sonic hedgehog (shh) and Brachyury (T) exhibited abnormal patterns in the anterior-posterior (A-P) direction at both mesencephalic and thoracic levels. These results suggest that KIF3A might be involved in mesodermal patterning and in turn neurogenesis.

Displacement of gold marker in immunoelectron microscopy of human respiratory cilia

Preembedding immunogold electron microscopy was performed to evaluate the position of outer arm dynein heavy chains in normal human respiratory cilia. Anti-dynein antibody (AD2), which is specific for sea urchin sperm flagellar dynein heavy chains, was used as primary antibody. Direct cross-sections of cilia were selected, and the distance between the center of a cilium and the center of a colloidal gold particle attached to the cilium (X) was measured. The distance between the center of a cilium and the farthest edge of an outer dynein arm of the cilium was measured by ordinary electron microscopy (Yo) and by immunoelectron microscopy (Yi). X was significantly longer than Yo and Yi. If it is assumed that the structure of respiratory cilia is dense and that antibodies are located at the outer side of the actual position of the heavy chains, then the average distance difference of approximately 90-120 A may represent the length of two conjugated antibodies. This length should be kept in mind when performing immunoelectron microscopy. The data suggest that AD2 recognizes the outer arm dynein heavy chains of normal human respiratory cilia.