Defective Chemokine-Directed Lymphocyte Migration and Development in the Absence of Rho Guanosine Diphosphate-Dissociation Inhibitors α and β

Abstract

Rho family small GTP-binding proteins, including Rho, Rac, and Cdc42, are key determinants of cell movement and actin-dependent cytoskeletal morphogenesis. Rho GDP-dissociation inhibitor (GDI) α and Rho GDIβ (or D4/Ly-GDI), closely related regulators for Rho proteins, are both expressed in hemopoietic cell lineages. Nevertheless, the functional contributions of Rho GDIs remain poorly understood in vivo. In this study, we report that combined disruption of both the Rho GDIα and Rho GDIβ genes in mice resulted in reduction of marginal zone B cells in the spleen, retention of mature T cells in the thymic medulla, and a marked increase in eosinophil numbers. Furthermore, these mice showed lower CD3 expression and impaired CD3-mediated proliferation of T cells. While B cells showed slightly enhanced chemotactic migration in response to CXCL12, peripheral T cells showed markedly reduced chemotactic migration in response to CCL21 and CCL19 associated with decreased receptor levels of CCR7. Overall, Rho protein levels were reduced in the bone marrow, spleen, and thymus but sustained activation of the residual part of RhoA, Rac1, and Cdc42 was detected mainly in the bone marrow and spleen. Rho GDIα and Rho GDIβ thus play synergistic roles in lymphocyte migration and development by modulating activation cycle of the Rho proteins in a lymphoid organ-specific manner.

Microarray analysis of perichondral and reserve growth plate zones identifies differential gene expressions and signal pathways

“…Mortality factor on chromosome 4 (Morf4) is a member of the MRG (Morfrelated genes) protein family, which plays a vital role in embryonic development, cell proliferation and cellular senescence [37]. Rho GDP-dissociation inhibitor 2 (Gdi2) binds to various Rho proteins and regulates their function in cell adhesion and migration, as well as multiple cellular activities including proliferation, apoptosis, and transcription [38]. The three pathways identified to be unique to the perichondrium by pathway analysis included those for ossification, bone remodeling, and cartilage development.…”

Enhancement of GDP-Dissociation Inhibitor Gene Expression in Osteoblasts by Low-Level Laser Irradiation

“…As shown in Figure 5, the increased gene expression of GDIA and GDIB by LLLI was significant after both 3 h and 6 h of LLLI. in the cytosol [10][11][12][13] .…”

Fractionation of Mature Eosinophils in GATA-Reporter Transgenic Mice

“…Preparation of mononuclear cell suspensions of the lung is an established technique (Stevens et al 2007) and several methods to analyze eosinophils in these parenchymal cell suspensions have been reported (Hansel et al 1991;Du et al 2002;Iwasaki et al 2005;Ishizaki et al 2006;Stevens et al 2007;Fukushima et al 2009;Mori et al 2009;Shen et al 2009). In previous approaches, eosinophils were fractionated according to specific gravity (Gärtner 1980) or their reactivity to specific antibodies against surface marker antigens with/without forward/side scatter gating (Hansel et al 1991;Du et al 2002;Ishizaki et al 2006;Rothenberg and Hogan 2006). In contrast, we used monoclonal antibodies only for negative selection.…”

“…For example, when mice are challenged with aerosolized chicken ovalbumin (OVA), the eosinophil population increases in an interleukin (IL)-5-dependent manner in the bone marrow, peripheral blood and in the BALF (Foster et al 1996;Kopf et al 1996). Detection of eosinophils has primarily been based on morphologic criteria, i.e., granulocytes with prominent eosinophil-specific basic granules (Shen et al 2003;Ishizaki et al 2006;Stevens et al 2007). This morphologic identification approach has several disadvantages, including variability in staining procedures, uniformity of inflammatory cell distribution, and reliance on the subjective interpretation of cell morphology in the quantitation of infiltrating cells.…”

“…To date, specific types of monoclonal antibodies combined with strict forward/side scatter gating are used in flow cytometry-based methods to fractionate the cells (Hansel et al 1991;Du et al 2002;Iwasaki et al 2005;Ishizaki et al 2006;Munoz and Leff 2006;Stevens et al 2007;Fukushima et al 2009;Mori et al 2009;Shen et al 2009). However, expression of multiple cell surface markers (e.g.…”