Walter I. Silva, Associate Professor

Ph.D., 1986, Mount Sinai 
School of Medicine 
Phone: (787) 758-2525 ext. 1608

email: wiso123@aol.com

Research Interests

In general terms my laboratory is interested in the cellular and molecular physiology of vascular and brain cells. Using cultured cells from vascular and brain tissue as models systems, we are focusing our efforts in understanding the role of subcellular transport vesicles in the transport of neuropeptide processing enzymes, and in the cellular level effects of the polyether marine toxins (brevetoxins, saxitoxins, ciguatoxins, and maitotoxins). In addition, the laboratory also studies the role of the recently characterized caveolae and their constituent caveolins in the differentiation of cultured vascular smooth muscle cells, and C6 glial cells. In the first area of interest the fundamental premise is forwarded that the peripheral and central effects of these marine neurotoxins are intimately linked to subcellular transport pathways and the signal transduction compartments that these define, i.e. the caveolar signal transduction compartment. This subcellular level approach shall provide an enhanced understanding of the mechanisms of action and the pathophysiology of the toxicity ensued by these toxins. On the second hand, the possibility is explored that the peripheral and central actions of neuropeptides (NP) are intimately linked to the expression of NP processing enzymes (NPE) in two coated vesicular transport organelles, clathrin coated vesicles (CCV) and caveolae (CAV). The main trust of this project rests on the opportunity to expand our fundamental knowledge on neuropeptide expression and function, and in providing a groundwork for understanding the subcellular basis of the regulation of NPE expression, both centrally and peripherally. Last but not least, our laboratory has recently succeeded in the initial characterization of caveolae and caveolins in C6 glial cells. These findings are particularly significant in relationship to the establishment of a model system to study the relevance of the caveolae compartment to signal transduction pathways in glial cells, and their fundamental relevance to the differentiation of these brain cells.

Selected Publications

  1. Rosa, R., W.I. Silva, G.E. Escalona, A.D. Rodríguez, J.J. Morales, and M. Ortiz. (1992). Anti-muscarinic activity of a family of C11 N5 compounds isolated from Agelas sponges. Experientia 48:885-807.

  2. Sanabria, P., and W.I. Silva, (1994). Specific 125I Bolton-Hunter Neuropeptide Y binding to intact cultured bovine adrenal medullary microvascular endothelial cells. Microcirculation 1(4):267-273.

  3. Mercado, J.A., Viera, M., Escalona de Motta, G., Tosteson, T., González, I., and Silva W.“Differences in toxicity, chromatografic profile and pharmacologic action of Ostreopsis lenticularis extracts revealed modifying the extraction procedure” pages 321-326. In, Harmful Marine Algal Blooms, P. Lassus, G. Arzul, Erard, P. Gentien and C. Marcillou, Editors Technique et Documentation-Lavoisier, Intercept, Ltd, 1995.

  4. Silva, W.I., K. Benítez, J. Ocasio, L. Martínez, and N. Rosario (1995). Neuropeptide-like immunoreactivities and Carboxypeptidase H activity associated with bovine brain clathrin coated vesicles. Neuropeptides 28:341-9.

  5. Silva, W.I., Maldonado, H., Chompré, G., and Mayol, N. Caveolae: A new subcellular transport organelle. Bulletin of P.R. Medical Association. In press, 1988.

  6. Silva, W.I., Maldonado, H.M., Lisanti, M.P., Chompré, G., and Mayol, N. Identification of Caveolae and Caveolin in C6 Glioma Cells. Submitted for publication.