Moesin is involved in microglial activation accompanying morphological changes and reorganization of the actin cytoskeleton.

Moesin is a member of the ezrin, radixin and moesin (ERM) proteins that are involved in the formation and/or maintenance of cortical actin organization through their cross-linking activity between actin filaments and proteins located on the plasma membranes as well as through regulation of small GTPase activities. Microglia, immune cells in the central nervous system, show dynamic reorganization of the actin cytoskeleton in their process elongation and retraction as well as phagocytosis and migration. In microglia, moesin is the predominant ERM protein. Here, we show that microglial activation after systemic lipopolysaccharide application is partly inhibited in moesin knockout (Msn-KO) mice. We prepared primary microglia from wild-type and Msn-KO mice, and studied them to compare their phenotypes accompanying morphological changes and reorganization of the actin cytoskeleton induced by UDP-stimulated phagocytosis and ADP-stimulated migration. The Msn-KO microglia showed higher phagocytotic activity in the absence of UDP, which was not further increased by the treatment with UDP. They also exhibited decreased ADP-stimulated migration activities compared with the wild-type microglia. However, the Msn-KO microglia retained their ability to secrete tumor necrosis factor α and nitric oxide in response to lipopolysaccharide.

Intracellular Cl- Regulation of Ciliary Beating in Ciliated Human Nasal Epithelial Cells: Frequency and Distance of Ciliary Beating Observed by High-Speed Video Microscopy.

Small inhaled particles, which are entrapped by the mucous layer that is maintained by mucous secretion via mucin exocytosis and fluid secretion, are removed from the nasal cavity by beating cilia. The functional activities of beating cilia are assessed by their frequency and the amplitude. Nasal ciliary beating is controlled by intracellular ions (Ca2+, H+ and Cl-), and is enhanced by a decreased concentration of intracellular Cl- ([Cl-]i) in ciliated human nasal epithelial cells (cHNECs) in primary culture, which increases the ciliary beat amplitude. A novel method to measure both ciliary beat frequency (CBF) and ciliary beat distance (CBD, an index of ciliary beat amplitude) in cHNECs has been developed using high-speed video microscopy, which revealed that a decrease in [Cl-]i increased CBD, but not CBF, and an increase in [Cl-]i decreased both CBD and CBF. Thus, [Cl-]i inhibits ciliary beating in cHNECs, suggesting that axonemal structures controlling CBD and CBF may have Cl- sensors and be regulated by [Cl-]i. These observations indicate that the activation of Cl- secretion stimulates ciliary beating (increased CBD) mediated via a decrease in [Cl-]i in cHNECs. Thus, [Cl-]i is critical for controlling ciliary beating in cHNECs. This review introduces the concept of Cl- regulation of ciliary beating in cHNECs.

Airway Ciliary Beating Affected by the Pcp4 Dose-Dependent [Ca2+]i Increase in Down Syndrome Mice, Ts1Rhr.

In Ts1Rhr, a Down syndrome model mouse, the airway ciliary beatings are impaired; that is, decreases in ciliary beat frequency (CBF) and ciliary bend angle (CBA, an index of ciliary beat amplitude)). A resumption to two copies of the Pcp4 gene on the Ts1Rhr trisomic segment (Ts1Rhr:Pcp4+/+/-) rescues the decreases in CBF and CBA that occur in Ts1Rhr. In airway cilia, upon stimulation with procaterol (a ß2-agonist), the CBF increase is slower over the time course than the CBA increase because of cAMP degradation by Ca2+/calmodulin-dependent phosphodiesterase 1 (PDE1) existing in the metabolon regulating CBF. In Ts1Rhr, procaterol-stimulated CBF increase was much slower over the time course than in the wild-type mouse (Wt) or Ts1Rhr:Pcp4+/+/-. However, in the presence of 8MmIBMX (8-methoxymethyl isobutylmethyl xanthine, an inhibitor of PDE1) or calmidazolium (an inhibitor of calmodulin), in both Wt and Ts1Rhr, procaterol stimulates CBF and CBA increases over a similar time course. Measurements of cAMP revealed that the cAMP contents were lower in Ts1Rhr than in Wt or in Ts1Rhr:Pcp4+/+/-, suggesting the activation of PDE1A that is present in Ts1Rhr airway cilia. Measurements of the intracellular Ca2+ concentration ([Ca2+]i) in airway ciliary cells revealed that temperature (increasing from 25 to 37 °C) or 4αPDD (a selective transient receptor potential vanilloid 4 (TRPV4) agonist) stimulates a larger [Ca2+]i increase in Ts1Rhr than in Wt or Ts1Rhr:Pcp4+/+/-. In airway ciliary cells of Ts1Rhr, Pcp4-dose dependent activation of TRPV4 appears to induce an increase in the basal [Ca2+]i. In early embryonic day mice, a basal [Ca2+]i increased by PCP4 expressed may affect axonemal regulatory complexes regulated by the Ca2+-signal in Ts1Rhr, leading to a decrease in the basal CBF and CBA of airway cilia.

Application of the automated haematology analyzer XN-30 in an experimental rodent model of malaria.

BACKGROUND: The erythrocytic stage, where malaria parasites proliferate in human blood, is clinically significant as this causes the symptoms and illness of malaria. Experimental rodent models of malaria at the erythrocytic stage are used for the development of anti-malarial drugs and for biological analysis. An automated haematology analyzer XN-30 was developed for detection of infected red blood cells (iRBCs) in human blood samples and measurement of their parasitaemia in approximately 1 min through flow cytometry analysis. Additionally, the analyzer simultaneously measured other haematological parameters in these samples. It is inferred that the analyzer would also allow easy and rapid measurement of parasitaemia in mice and provide important clues on the mouse haematological state during infection and treatment. RESULTS: The XN-30 analyzer is a simple and rapid tool to detect iRBCs in mouse blood samples infected with rodent malarial parasites, with three-dimensional analysis permitting the precise measurement of parasitaemia (referred herein as the 'XN-30 system'). The XN-30 analyzer allowed not only the detection of iRBCs but also the monitoring of RBC, white blood cell, and platelet counts, as well as haematocrit, mean corpuscular volume and mean platelet volume values in the mouse blood sample. For anti-malarial drug development, aside from demonstrating possible efficacy in mouse models, XN-30 analyzer could provide a first glimpse of the safety profile of the drug. CONCLUSIONS: The XN-30 system is a powerful tool that can be utilized for the in vivo screening, development, and evaluation of anti-malarial drugs as well as for pre-clinical pharmacology and/or toxicity tests in rodent models.