Expression of molecular messages for angiogenesis by fibroblasts from aneurysmal abdominal aorta versus dermal fibroblasts

BACKGROUND

The molecular messages which drive angiogenesis in the adventitia of an aneurysmal aorta are uncertain. The emergence of molecular phenotyping by cDNA expression arrays provides a simple and rapid method for a preliminary approach to the analysis of molecular messengers for neovascularization in cultured cells. In the present experiment, fibroblasts cultured from the aorta of a patient with abdominal aortic aneurysm (AAA) were compared with normal dermal fibroblasts, on an array that evaluates several mRNAs with known roles in angiogenesis.

METHODS

RNA was isolated from fibroblasts and purified. Labelled cDNA probes were generated from a mixture of RNA and CDS primers. Atlas Array membranes (Clontech) were prehybridized by ExpressHyb buffer. The cDNA probes were then added to the membranes, which were exposed to Phospholmage Screen (Molecular Dynamics) and analysed by a dedicated computer program.

RESULTS

The most significantly upregulated mRNAs in AAA (by comparison to dermal fibroblasts) were: MCAF, MDNCF, EGR-1, VEGF, FGF-7, Mal protein, Mac Marcks, Transducin, Interleukin-9 receptor, and TNF.

CONCLUSION

VEGF and TNF were upregulated, as expected. However, the upregulation of monocyte chemotactic and activating factor (MCAF) and monocyte-derived neutrophil chemotactic factor (MDNCF) suggest that the fibroblast may be more significantly involved in driving the inflammatory response that leads to AAA than previously realized.

A simple in vivo model to evaluate the effects of antiarrhythmic agents

Antiarrhythmic agents alter cardiac conduction, refractoriness, and action potential duration in a rate dependent fashion. A simple in vivo model was developed to measure these variables over a wide range of cycle lengths. Complete heart block was produced in dogs using an 8 French hexapolar ablation catheter, anterior skin electrode, and radiofrequency current (30 W, 13.6 +/- 2.6 seconds). Ventricular pacing and monophasic action potential recordings were performed using a single combination catheter. QRS and action potential durations were measured at multiple cycle lengths and after an abrupt change in paced cycle length. Ventricular effective refractory periods were also measured at multiple cycle lengths. Data obtained during flecainide and d-Sotalol infusions are presented. This simple model allows detailed in vivo evaluation of the electrophysiological effects of antiarrhythmic agents and combinations.