Optic nerve regeneration requires the intracellular domain of LIFRα/CD118
Qian Jiang, Cong Wang, Yuerong Ren, Peiyun Duan, Ke Tian, Xiangwei Duan, Binghan Cai, Changzhong Xu, Ke Liu, Jian Li, Larry Benowitz, Ningli Wang, Bing Jiang, Lili Xie
Qian Jiang, Cong Wang, Yuerong Ren, Peiyun Duan, Ke Tian, Xiangwei Duan, Binghan Cai, Changzhong Xu, Ke Liu, Jian Li, Larry Benowitz, Ningli Wang, Bing Jiang, Lili Xie
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Research Article Neuroscience Ophthalmology

Optic nerve regeneration requires the intracellular domain of LIFRα/CD118

Abstract

Identifying factors that govern the ability of retinal ganglion cells (RGCs) to extend axons is an important step in developing therapies to achieve recovery after optic nerve injury. Here, we report that the intracellular domain of the leukemia inhibitory factor receptor (LIFR/CD118) is essential for mature RGCs’ ability to regenerate injured axons independent of the cognate ligand (LIF) and other therapies. Overexpression of LIFR in adult RGCs induces neurite outgrowth in cultured RGCs and axon regeneration in vivo while strongly amplifying RGCs’ response to LIF itself and to unrelated growth factors. Conversely, downregulation of LIFR strongly suppresses the pro-regenerative effects of PTEN knockdown and other potent stimuli. LIFR modulation alters the constitutive activity of the MAPK pathway, in contrast to LIF itself, which primarily activates pSTAT3. The extracellular domain–truncated LIFR construct retains substantial pro-regenerative activity, whereas mutation of intracellular signaling motifs reduces the full regenerative effect of LIFR. Together, these findings identify LIFR as a key cell-autonomous regulator of optic nerve regeneration in mature RGCs.

Authors

Qian Jiang, Cong Wang, Yuerong Ren, Peiyun Duan, Ke Tian, Xiangwei Duan, Binghan Cai, Changzhong Xu, Ke Liu, Jian Li, Larry Benowitz, Ningli Wang, Bing Jiang, Lili Xie

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Figure 5

LIFR knockdown suppresses optic nerve regeneration.

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LIFR knockdown suppresses optic nerve regeneration. (A) Retinal cross se...
(A) Retinal cross sections from mice 2 weeks after AAV2-shScramble or AAV2-shLIFR injection immunostained for LIFR (green) and RBPMS (red) and stained with DAPI (blue). GCL, ganglion cell layer; IPL, inner plexiform layer. Scale bar: 30 μm. This experiment was conducted once. (B) Quantification of LIFR intensity in RGCs. Dashed line indicates LIFR intensity when the first antibody is omitted during immunostaining. Statistical significance was determined by unpaired 2-tailed t test (*P < 0.05; n = 3–4 eyes per group). (C, F, and I) Representative images of axon regeneration (green) and RGC survival (red) after LIFR knockdown combined with zymosan (C), AAV2-shPTEN (F), or AAV2-miR-21-sponge (I). An asterisk indicates the injury site. Scale bars: 100 μm (left) and 50 μm (right). The experiments in C and F were conducted once, and experiments in I were conducted twice. (D, G, and J) Quantification of axon regeneration after LIFR knockdown combined with zymosan (D), AAV2-shPTEN (G), or AAV2-miR-21-sponge (J). Statistical significance was determined by an unpaired 2-tailed t test; ***P < 0.001, ****P < 0.0001; n = 8–12 nerves (D), 7–9 nerves (G), and 11–17 nerves (J) per group. (E, H, and K) Quantification of RGC survival after LIFR knockdown combined with zymosan (E), AAV2-shPten (H), or AAV2-miR-21-sponge (K). Statistical significance was determined by an unpaired 2-tailed t test; n.s. P > 0.05, ***P < 0.001; n = 4 eyes (E), 7–8 eyes (H), and 5–7 eyes (K) per group. Data represent mean ± SEM.