Fig. 4

IL-6 Family Cytokines Signaling through Gp130 Are Necessary and Sufficient for Retina Regeneration

(A) In situ hybridization and immunofluorescence show that gp130, il-11a, crlf1a, and clcf1 are expressed in BrdU⁺ MG-derived progenitors localized to the injury site.

(B) qPCR quantifies il-6 family gene induction in MG-derived progenitors (FACS purified from 1016tuba1a:gfp fish retinas at 4 dpi) relative to MG from uninjured retina (FACS purified from uninjured gfap:gfp fish retinas). p < 0.05, n = 3.

(C and D) Gp130 knockdown inhibits the generation of BrdU⁺ MG-derived progenitors at 4 dpi. Control (Ctl) or gp130-targeting MOs were electroporated into the retina at the time of injury and the fish received an i.p. injection of BrdU 3 hr before sacrifice on 4 dpi. p < 0.001, n = 4.

(E) qPCR showing Gp130 knockdown inhibits injury-dependent induction of reprogramming genes at 2 dpi. p < 0.05, p < 0.01, n = 4.

(F) Intravitreal injection of recombinant mammalian IL-6-like cytokines into the uninjured eye of 1016tuba1a:gfp fish stimulates GFP expression and BrdU incorporation in MG throughout the retina’s INL. Intravitreal injection of PBS/BSA did not stimulate GFP expression or BrdU incorporation. The green fluorescence above the ONL in the top left-hand panel is autofluorescence unique to the green channel (see Figure S7K).

(G) Quantification of BrdU⁺ cells following intravitreal injection of recombinant mammalian IL-6-like cytokines (n = 3).

Error bars, SD. In (A) and (C), the asterisks mark the injury site (needle poke). In (A), (C), and (F), arrows point to MG-derived progenitors. Scale bars, 20 µm (A and C) and 50 µm (F). GCL, ganglion cell layer. Primers are listed in Table S1. See also Figures S5 and S6.