ABSTRACT
Angiopoietin (Ang)-1 and Ang-2 interact in angiogenesis to activate the Tie-2 receptor, which may be involved in new vessel maturation and regression. Mast cells (MCs) are also involved in formation of new blood vessels and angiogenesis. The present study was designed to test whether MCs can mediate angiogenesis in myocardial microvascular endothelial cells (MMVECs). Using a rat MMVEC and MC co-culture system, we observed that Ang-1 protein levels were very low even though its mRNA levels were increased by MCs. Interestingly, MCs were able to enhance migration, proliferation, and capillary-like tube formation, which were associated with suppressed Ang-2 protein expression, but not Tie-2 expression levels. These MCs induced effects that could be reversed by either tryptase inhibitor [N-tosyl-L-lysine chloromethyl ketone (TLCK)] or chymase inhibitor (N-tosyl-L-phenylalanyl chloromethyl ketone), with TLCK showing greater effects. In conclusion, our data indicated that MCs can interrupt neovessel maturation via suppression of the Ang-2/Tie-2 signaling pathway.
ABSTRACT
Two vector-borne communicable diseases, malaria and dengue, are among a number of diseases of particular importance in relation to economic development in Southeast Asia and thus need to be assessed in relation to economic parameters in the region. Geographical Information Systems (GIS) provide one means of comparing disease and resource data versus time and place, to facilitate rapid visualization by planners and administrators. Given that Thailand is a global epicenter of multidrug resistant falciparum malaria and of dengue hemorrhagic fever, both of which are mosquito-borne, application of GIS methods to these two diseases gives opportunity for comparison of resource needs and allocation in relation to disease epidemiologic patterns. This study examined per capita gross provincial product (GPPpc) and health care resources in relation to geographic distribution of malaria and dengue in Thailand. The two diseases vary greatly in overall seasonal patterns and in relation to provincial economic status, and present differing demands on resource utilization: planned integration of control of malaria and dengue could utilize such analyses in relation to resource sharing and consideration of allocative efficiency. The concentration of malaria (and to a lesser extent dengue) along international border areas underscores the desirability of multi-country coordination of disease management and control programs. Because socio-economic and disease data are collected by quite different means and in different time frames, there are some limitations to the dynamic interpolation of these two broad data sets, but useful inferences can be drawn from this approach for application to overall planning, at both national and multi-country levels.