Wnt5a protects motor neurons in amyotrophic lateral sclerosis by regulating the Wnt/Ca2+ signaling pathway

Jinmeng Liu; Fenghua Zhou; Yanchun Chen; Yingjun Guan; Fandi Meng; Zhenhan Zhao; Xuemei Wang; Xueshuai Gao; Xin Jiang; Haoyun Zhang; Qing Wang; Shuanhu Zhou; Xin Wang

Wnt5a protects motor neurons in amyotrophic lateral sclerosis by regulating the Wnt/Ca²⁺ signaling pathway

Am J Transl Res. 2022 Aug 15;14(8):5343-5362. eCollection 2022.

Authors

Jinmeng Liu¹, Fenghua Zhou², Yanchun Chen^{3

4}, Yingjun Guan³, Fandi Meng³, Zhenhan Zhao³, Xuemei Wang³, Xueshuai Gao³, Xin Jiang³, Haoyun Zhang⁴, Qing Wang⁴, Shuanhu Zhou⁵, Xin Wang⁶

Affiliations

¹ Laboratory of Biochemistry and Molecular Biology, Weifang Medical University Weifang 261053, Shandong, PR China.
² Department of Pathology, Weifang Medical University Weifang 261053, Shandong, PR China.
³ Department of Histology and Embryology, Weifang Medical University Weifang 261053, Shandong, PR China.
⁴ Neurologic Disorders and Regenerative Repair Laboratory, Weifang Medical University Weifang 261053, Shandong, PR China.
⁵ Department of Orthopaedic Surgery, Brigham and Women's Hospital, Harvard Medical School Boston 02115, MA, USA.
⁶ Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School Boston 02115, MA, USA.

PMID: 36105066
PMCID: PMC9452359

Abstract

Objectives: We aimed to detect the expression profile of downstream signaling molecules of non-canonical Wnt pathway in SOD1^G93A transgenic mice (ALS mice) and SOD1^G93A mutant motor neuron-like hybrid (NSC-34) cells. Characterizing the molecular mechanism of the Wnt5a-mediated non-canonical Wnt/Ca²⁺ signaling pathway in motor neuron (MN) degeneration may provide a feasible approach to effective treatment of amyotrophic lateral sclerosis (ALS).

Methods: The expressions of CaMKII-α, CaMKII-β and TAK1 in the spinal cord of SOD1^G93A ALS transgenic mice at different ages were determined using western blotting and immunofluorescence. The level of Ca²⁺ and cell apoptosis were assessed with flow cytometry and cell viability was evaluated using MTS assay. Cell proliferation was analyzed by the EdU cell proliferation assay. Neurite length was measured after treatment with retinoic acid.

Results: CaMKII-α, CaMKII-β, and TAK1 were down-regulated in the spinal cord of ALS mice. Ca²⁺ level and CaMKII-α, CaMKII-β, and TAK1 were down-regulated in SOD1^G93A mutant NSC-34 cells. Expression of Ca²⁺, CaMKII-α, CaMKII-β, and TAK1 were up-regulated in SOD1^G93A mutant NSC-34 cells after Wnt5a overexpression and down-regulated after Wnt5a knockdown. Overexpression of Wnt5a promoted cell viability and proliferation but inhibited cell apoptosis. Contrastingly, Wnt5a knockdown inhibited cell viability and proliferation but promoted cell apoptosis. CaMKII inhibitor KN-93 and CaMKII activator oleic acid reversed changes in cell viability, proliferation, apoptosis, and neurite outgrowth induced by Wnt5a overexpression and knockdown.

Conclusions: This study demonstrates that Wnt5a protects MNs in ALS by regulating cell viability, proliferation, apoptosis, and neurite growth through the Wnt/Ca²⁺ signaling pathway. Our data indicate that the non-canonical Wnt/Ca²⁺ signaling pathway regulated by Wnt5a is involved in MN degeneration in ALS.

Keywords: ALS; Wnt/Ca2+ signaling; Wnt5a; apoptosis; neurite growth; proliferation.