Fig. 2

Meningeal Lymphatics Rapidly Grow into the Injured Parenchyma in Response to Cerebrovascular Damage

(A and B) Time-lapse imaging showed the growth of meningeal lymphatics into the injured area (A) (n = 10/10). Images at the early phases after Mtz treatment showed the initiation of ingrowth and branching of meningeal lymphatics by 3D reconstruction (B) (n = 10/10). The elapsed time is indicated in h:min after 0 dpt. Blue and purple frames indicate the image areas of corresponding panels. See also Videos S1 and S2.

(C–G) The ingrown vessels originate from lyve1b+ cells. Transgenic lines, time points of Mtz and 4-OHT administrations were shown in (C). Negatively controlled by Mtz plus ethanol (D) (n = 12/12) and positively controlled by DMSO plus 4-OHT (E) (n = 19/21), the ingrown vessels were double positive for anti-DsRed and anti-GFP antibodies if Mtz plus 4-OHT were applied (F) (n = 21/24). The statistics show the ratios of the lyve1b:DsRed-labeled vessels positive for GFP (G) (n = 10). Two-tailed unpaired t test, p < 0.0001. ^∗∗∗p < 0.001. Data are represented as mean ± SEM. Scale bar, 50 μm.

(H and I) In contrast to DMSO treatment (H) (n = 10/10), photoconversion of muLECs at BT followed by Mtz treatment resulted in retention of Kaede-red fluorescence in the ingrown vessels at 2 dpt (I) (n = 12/12). BT, before treatment. Scale bar, 50 μm.

All images are dorsal view, anterior upward.

AceV, anterior (rostral) cerebral vein; BA, basilar artery; CtA, central artery; iLVs, ingrown lymphatic vessels; MsV, mesencephalic vein; MMCtA, middle mesencephalic central artery; MtA, metencephalic artery; muLECs, meningeal mural lymphatic endothelial cells.