The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.

 

Johns Hopkins School of Public Health

Research Grants 1998-1999

In Vitro Evaluation of Pharmacological Interventions Aimed to Prevent Atherosclerosis

Rita B. Alevriadou, PhD
Johns Hopkins University, Baltimore, Maryland

In vivo experimental evidence indicates that monocytes bind more avidly to epithelial cells (ECs) in hypercholesterolemic animals, and enter the intimal space where they contribute to the formation of fatty streaks. Hypercholesterolemia also causes an increased production of oxygen free radicals by ECs. In vitro studies using cultured ECs treated with minimally-modified (mildly-oxidized) low-density lipoprotein (MM-LDL) have shown that these cells promote the atherosclerotic process by expressing proinflammatory and procoagulant activity (increased synthesis of monocyte chemotactic protein-1 and tissue factor, and decreased production of nitric oxide). Alevriadou and colleagues seek to:

  1. understand the relative contributions of each one of the changes that MM-LDL causes in EC function, to the adhesive interactions between blood cells (monocytes, lymphocytes, platelets) and ECs at the early stages of atherosclerosis, and
  2. propose better treatments that would either prevent or delay the progression of the disease. Previously, the investigator designed a perfusion system of cells in suspension over EC-coated surfaces, coupled with video microscopy and digital image processing, that allows us to quantity the adhesion of flowing blood cells onto cultured ECs.

Currently, the laboratory is working to:

  1. Evaluate the in vitro model by perfusing samples of mixed suspensions of leukocytes and platelets over EC monolayers, preincubated or not with MM-LDL, visualizing the adherent cells by phase-contrast microscopy, and quantifying cell-cell interactions.
  2. Compare the ability of key antioxidants, such as vitamin E (a-tocopherol), to restore the lack of interactions between flowing blood cells and MM-LDL-treated ECs. Ultimately, Alevriadou plans to use an in vitro perfusion model to assess the relative potencies of key pharmacological agents currently used for prevention/treatment of atherosclerosis and cardiovascular disease (besides cholesterol-lowering drugs).