Figure 2.

Lymphatic vessel endothelial hyaluronan receptor–1 (LYVE-1) is specifically expressed in lymphatic vessels and is dramatically reduced in vessels of Lama2-deficient muscle. (A) Lymphatic vessels and blood vessels within skeletal muscle tissue can be distinguished by the expression of LYVE-1 and CD31 (PECAM-1). Shown are quadriceps muscles from a 3-day-old Lama2-expressing mouse double immunostained for LYVE-1 and CD31. The hyaluronan receptor LYVE-1 (green) is specifically expressed in lymphatic vessel endothelial cells. CD31, a pan-endothelial marker, is expressed by vascular endothelial cells found in blood capillary vessels (red) but is only expressed at low levels in lymphatic vessel endothelial cells and is often not detectable except in larger trunk lymphatic vessels where expression of both markers can be evident (arrows; scale bar=100 µm). (B) LYVE-1 expression in lymphatic vessels is dramatically reduced in 1- and 2-week-old Lama2(-) muscles compared with those of normal Lama2(+) mice. Quadriceps muscles from Lama2(-) (Lama2^-/-) and Lama2(+) (Lama^{+/+ or +/-}) mice were immunostained using antibodies for LYVE-1 (green) or CD31 (red). The pattern of CD31 expression in blood vessels is not affected by Lama2 deficiency (scale bars=100 µm).