THBS1 and Alzheimer disease: To investigate the contribution of astrocyte-derived TSP-1 to impaired meningeal lymphatic drainage in AD, we used an AAV-Thbs1-shRNA-mCherry construct (controlled by the GfaABC1D promoter) to selectively knock down Thbs1 in the hippocampal astrocytes of 5 × FAD mice (Fig. 3a).