Fig. 4

Interleukin-4 Is Necessary and Sufficient for Aβ42-Dependent Stem Cell Proliferation and Neurogenesis in Adult Zebrafish Brain

(A–B'') IL4 in control (A–A'') and TR-Aβ42-injected (B-B'') brains. Parenchyma (A' and B') and ventricle (A'' and B'') are shown.

(C) IL4, L-plastin, and HuC/D in TR-Aβ42-injected brains.

(C') Close-up on a neuron (HuC/D-positive, red) with TR-Aβ42 (green) and IL4 (white).

(D–D'') il4r receptor expression in TR-Aβ42 brains at 3 dpi. Sense (D) and antisense (D'). (D'') High magnification.

(E and F) S100β and PCNA in control (E) and IL4-injected (F) brains.

(G) Quantification graph for (E and F).

(H and I) BrdU and HuC/D in control (H) and IL4-injected (I) brains.

(J) Quantification graph for (H and I).

(K and K') IL4 detection with neutralizing antibody in control (K) and TR-Aβ42-injected (K') brains.

(L and L') Secondary antibody staining for the neutralizing IL4 antibody (nIL4ab) in uninjected (L) and injected brains at 1 day after injection (L').

(M and N) PCNA and S100β in TR-Aβ42-injected (M) and in TR-Aβ42 + neutralizing antibody-co-injected (N) brains. Insets: single fluorescence channels.

(O) Quantification graph. Control = 1.

(P–P''') Phospho-STAT6 in PBS- (P), TR-Aβ42- (P'), IL4- (P”), and TR-Aβ42 + neutralizing IL4-antibody-injected (P''') brains. Red channels shown separately. Insets: close-up image of one exemplary cell.

(Q–S) PCNA and S100 in TR-Aβ42 and control morpholino-injected (Q) and in TR-Aβ42 and IL4R morpholino-injected (R) brains. (S) Quantification graph.

(T and U) IL4 after TR-Aβ42 in PBS (T) or clodronate-injected (U) brains.

(V–Z) PCNA and S100 after TR-Aβ42 in PBS (V), clodronate (X) or clodronate + IL4-injected (Y) brains. (Z) Quantification graph for (V–Y).

Scale bars, 50 μm (A, B, E–I, M, N, Q, R,V–Y), 10 μm (A', A'', B', B'', C, P–P''', T, and U), and 20 μm (K–L'). Data are represented as mean ± SD; n = 4 fish. ^∗p < 0.05; ^∗∗p < 0.01; ^∗∗∗p < 0.001; n.s., not significant. See also Figure S4.