TY - JOUR
T1 - The effect of extrinsic Wnt/β-catenin signaling in Muller glia on retinal ganglion cell neurite growth
AU - Musada, Ganeswara Rao
AU - Dvoriantchikova, Galina
AU - Myer, Ciara
AU - Ivanov, Dmitry
AU - Bhattacharya, Sanjoy K.
AU - Hackam, Abigail S.
N1 - Funding Information:
Support for this study was from the NIH/NEI R01 EY026546 (ASH), R01 EY027311 (DI), and U.S. Department of Defence (WHX81-16-0715) (SKB). Institutional support to BPEI was from a Research to Prevent Blindness Unrestricted Grant and an NEI Center Core Grant EY014801.
PY - 2020/3/1
Y1 - 2020/3/1
N2 - Muller glia are the predominant glial cell type in the retina, and they structurally and metabolically support retinal neurons. Wnt/β-catenin signaling pathways play essential roles in the central nervous system, including glial and neuronal differentiation, axonal growth, and neuronal regeneration. We previously demonstrated that Wnt signaling activation in retinal ganglion cells (RGC) induces axonal regeneration after injury. However, whether Wnt signaling within the adjacent Muller glia plays an axongenic role is not known. In this study, we characterized the effect of Wnt signaling in Muller glia on RGC neurite growth. Primary Muller glia and RGC cells were grown in transwell co-cultures and adenoviral constructs driving Wnt regulatory genes were used to activate and inhibit Wnt signaling specifically in primary Muller glia. Our results demonstrated that activation of Wnt signaling in Muller glia significantly increased RGC average neurite length and branch site number. In addition, the secretome of Muller glia after induction or inhibition of Wnt signaling was characterized using protein profiling of conditioned media by Q Exactive mass spectrometry. The Muller glia secretome after activation of Wnt signaling had distinct and more numerous proteins involved in regulation of axon extension, axon projection and cell adhesion. Furthermore, we showed highly redundant expression of Wnt signaling ligands in Muller glia and Frizzled receptors in RGCs and Muller glia. Therefore, this study provides new information about potential neurite growth promoting molecules in the Muller glia secretome, and identified Wnt-dependent target proteins that may mediate the axonal growth.
AB - Muller glia are the predominant glial cell type in the retina, and they structurally and metabolically support retinal neurons. Wnt/β-catenin signaling pathways play essential roles in the central nervous system, including glial and neuronal differentiation, axonal growth, and neuronal regeneration. We previously demonstrated that Wnt signaling activation in retinal ganglion cells (RGC) induces axonal regeneration after injury. However, whether Wnt signaling within the adjacent Muller glia plays an axongenic role is not known. In this study, we characterized the effect of Wnt signaling in Muller glia on RGC neurite growth. Primary Muller glia and RGC cells were grown in transwell co-cultures and adenoviral constructs driving Wnt regulatory genes were used to activate and inhibit Wnt signaling specifically in primary Muller glia. Our results demonstrated that activation of Wnt signaling in Muller glia significantly increased RGC average neurite length and branch site number. In addition, the secretome of Muller glia after induction or inhibition of Wnt signaling was characterized using protein profiling of conditioned media by Q Exactive mass spectrometry. The Muller glia secretome after activation of Wnt signaling had distinct and more numerous proteins involved in regulation of axon extension, axon projection and cell adhesion. Furthermore, we showed highly redundant expression of Wnt signaling ligands in Muller glia and Frizzled receptors in RGCs and Muller glia. Therefore, this study provides new information about potential neurite growth promoting molecules in the Muller glia secretome, and identified Wnt-dependent target proteins that may mediate the axonal growth.
KW - Muller glia
KW - Wnt signaling
KW - neurite growth
KW - proteomics
KW - retinal ganglion cells (RGC)
KW - secretome
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U2 - 10.1002/dneu.22741
DO - 10.1002/dneu.22741
M3 - Article
C2 - 32267608
AN - SCOPUS:85083593200
VL - 80
SP - 98
EP - 110
JO - Developmental Neurobiology
JF - Developmental Neurobiology
SN - 0022-3034
IS - 3-4
ER -