Affiliations: [a] College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China
| [b] Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| [c] College of Sciences, University of Texas at San Antonio, San Antonio, TX, USA
| [d] Center for Mitochondrial Diseases, Case Western Reserve University, Cleveland, OH, USA
Correspondence:
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Correspondence to: Xinglong Wang, Department of Pathology, Case Western Reserve University, Cleveland, OH, USA. E-mail: xinglong.wang@case.edu. and Xuemei Ma, College of Life Science and Bio-engineering, Beijing University of Technology, Beijing, China. E-mail: xmma@bjut.edu.cn.
Abstract: Alzheimer’s disease (AD) and other tauopathies are characterized by intracellular accumulation of microtubule-associated tau protein leading to neurodegeneration. Calpastatin is the endogenous inhibitor of calpain, a calcium-dependent cysteine protease that has been increasingly implicated in tauopathies. In this study, we generated a neuron specific calpastatin overexpressing knock-in transgenic mouse model and crossed it with the PS19 tauopathy mouse model expressing human P301S mutant tau protein. The forced expression of calpastatin in neurons significantly alleviated tau hyperphosphorylation measured by immunocytochemistry and immunoblot. The genetic inhibition of calpain by calpastatin also greatly suppressed characteristic hippocampal neuron loss and widespread astrogliosis and microgliosis in PS19 mice. Consistently, PS19 mice with neuronal calpastatin overexpression exhibited remarkably alleviated cognitive deficits, muscle weakness, skeletal muscle atrophy, and neuromuscular denervation, together implying the neuroprotective effects of neuronal calpastatin in PS19 mice of tauopathy. In sum, this study provides additional evidence supporting the pathological role of calpain in neurodegenerative diseases associated with tau pathology, and suggests that targeting calpain is likely a promising therapeutic approach for these devastating diseases.
Keywords: Calpain, calpastatin, cognitive deficits, dementia, motor dysfunction, neurodegeneration, neuroinflammation, neuromuscular junction, tau phosphorylation, tauopathy
