Hyaluronidase treatment of acute lymphedema in a mouse tail model

The purpose of this study was to investigate the impact of hyaluronidase (HAase) on lymphedema using an acute mouse tail lymphedema model. Six-week-old mice served to produce acute lymphedema and were then either treated with HAase injection or used as operative controls. An additional group of unmanipulated normal mice was used for comparison. Tail volumes were measured for 23 days and histological changes examined. Western blot analysis was conducted to quantify lymphatic vessel endothelial hyaluronan receptor (LYVE)-1, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, podoplanin, CD 44, and vascular endothelial growth factor receptor3 (VEGFR3) expression levels. The operative control group showed an increase in thickness of the dermis and subdermis, microlymphatic dilatation, and an increase in neutrophils. In contrast, the HAase treated group exhibited alleviation of inflammation evidenced by a decline in microlymphatic dilatation and neutrophils and an overall increase in microlymphatic vessels. Western blot analysis demonstrated that TNF-alpha and TGF-beta1 expression declined but CD44 expression increased in the HAase treated group. Levels of LYVE1, podoplanin, and VEGFR3 also increased significantly in the HAase group. Our results indicate that HAase treatment in the acute mouse tail model reduced lymphedema volume possibly through degradation of HA trafficking, which reduced inflammation and fibrosis in tissues and stimulated lymphangiogenesis.