This Week in Experimental and Molecular Pathology

In Experimental and Molecular Pathology, researchers in the US, the UK, and Japan describe their method for the identification of anti-renal antibodies in patients with age-related macular degeneration. "In order to reveal retinal antigens targeted by serum IgG from AMD patients, mouse retinal tissue proteins were separated by 2-dimensional electrophoresis and the proteins in the immunoblots that were specific for dry and wet AMD patients' IgG were identified by LC-MS/MS," the team says. They found that retinol-binding protein 3 and aldolase C were mostly recognized by IgG from wet AMD patients and that pyruvate kinase M2 was targeted by both dry and wet AMD. Further, the team adds, "level of anti-PKM2 IgG antibody was correlated best with the stage of AMD." This suggests that the serum from an AMD patient contains auto-antibodies against retinal proteins, and that anti-PKM2 IgG could be used as a biomarker for AMD diagnosis and prognosis.

Also in Experimental and Molecular Pathology, researchers in Australia and the US report that the activation of endothelial cells promotes monocytes' formation of foam cells, a pathological feature of atherosclerosis. Using an existing in vitro model of transendothelial migration, the team found that monocytes undergo transendothelial migration "across a primary endothelial monolayer into an underlying three-dimensional collagen matrix in the presence of 20 percent human serum." This, the researchers say, demonstrates that in the absence of additional lipids, sub-endothelial monocytes can develop into foam cells within 48 hours of transendothelial migration across TNF-α activated endothelium. "Our data indicate a role for both monocyte-endothelial interactions and soluble factors in the regulation of foam cell development, including oxidation of LDL in situ from lipid present in culture medium following TNF-α stimulation of the endothelial cells," they add.