Protein Promotes Blood Vessel Development

By identifying a protein that promotes blood vessel development by causing cells to stick together (a process known as angiogenesis), researchers from Texas A&M University’s Institute of Biosciences and Technology in Houston now can design substances to block cardiovascular diseases. The findings were reported in the April 1 EMBO Journal, the journal of the European Molecular Biology Organization.

Scientists in the laboratory of Kishore Wary, Ph.D., made the discovery as they were studying the cellular behavior of endothelial cells, which are directly responsible for the formation of new blood vessels.

“Studying endothelial cells is important,” Wary said, “because deregulated angiogenesis contributes to cardiovascular diseases such as atherosclerosis, myocardial ischemia, stroke, thrombosis, and cardiac infarction. Angiogenesis also augments rheumatoid arthritis, diabetic retinopathy, aging, psoriasis, and the metastatic growth of tumors.”

In adults, endothelial cells remain dormant for as long as 5 to 7 years. However, in response to injury or bacterial/viral infection, the vasculature becomes inflamed, and endothelial cells become activated. Activated endothelial cells often synthesize and present a unique set of cell surface molecules that are different from dormant endothelial cell surfaces. Thus, identifying and characterizing such distinct molecular targets presented by the activated endothelial cells can be helpful in developing new diagnostic and therapeutic approaches, including substances to interfere with the growth of new blood vessels or enhance angiogenesis wherever it is required.

Scientists in Wary’s lab identified a candidate protein called Phosphatidic acid phosphatase 2b from activated endothelial cells. They also discovered that elevated expression of the protein could induce cell-to-cell interaction in cultured cells.

“Cell-to-cell interaction means that cells adhere to each other directly. In other words, we say these cells become very sticky or adhesive, and this was a surprising and unexpected observation,” Wary said. “However, PAP2b is not the only molecule that could do the job of promoting cell-to-cell interaction. There are several other known cell adhesion molecules that do similar jobs.”

Wary’s lab is now beginning to understand the biochemical mechanisms of how the protein induces cell-to-cell interaction and promotes “sticky” behavior. Further study will be required to understand fully how the protein works.

The study was made possible by a grant from the American Heart Association National Council and from the new faculty start-up fund at Texas A&M University.

E-Mail: tmcinfo@texmedctr.tmc.edu
URL: http://www.tmc.edu/tmcnews/04_15_03/page_24.html