Butyrate Ameliorates Mitochondrial Respiratory Capacity of The Motor-Neuron-like Cell Line NSC34-G93A, a Cellular Model for ALS.

Xuejun Li,Jianxun Yi,Jingsong Zhou,Marco Brotto,Ang Li,Li Dong

doi:10.3390/biom12020333

Xuejun Li, Jianxun Yi + Show 4 more

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https://doi.org/10.3390/biom12020333

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Journal: Biomolecules	Publication Date: Feb 19, 2022
Citations: 14	License type: CC BY 4.0

Affiliation: The University of Texas at Arlington

Abstract

Mitochondrial defects in motor neurons are pathological hallmarks of ALS, a neuromuscular disease with no effective treatment. Studies have shown that butyrate, a natural gut-bacteria product, alleviates the disease progression of ALS mice overexpressing a human ALS-associated mutation, hSOD1G93A. In the current study, we examined the potential molecular mechanisms underlying the effect of butyrate on mitochondrial function in cultured motor-neuron-like NSC34 with overexpression of hSOD1G93A (NSC34-G93A). The live cell confocal imaging study demonstrated that 1mM butyrate in the culture medium improved the mitochondrial network with reduced fragmentation in NSC34-G93A cells. Seahorse analysis revealed that NSC34-G93A cells treated with butyrate showed an increase of ~5-fold in mitochondrial Spare Respiratory Capacity with elevated Maximal Respiration. The time-dependent changes in the mRNA level of PGC1α, a master regulator of mitochondrial biogenesis, revealed a burst induction with an early increase (~5-fold) at 4 h, a peak at 24 h (~19-fold), and maintenance at 48 h (8-fold) post-treatment. In line with the transcriptional induction of PGC1α, both the mRNA and protein levels of the key molecules (MTCO1, MTCO2, and COX4) related to the mitochondrial electron transport chain were increased following the butyrate treatment. Our data indicate that activation of the PGC1α signaling axis could be one of the molecular mechanisms underlying the beneficial effects of butyrate treatment in improving mitochondrial bioenergetics in NSC34-G93A cells.

Highlights

Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease characterized by progressive motor neuron loss and severe skeletal muscle wasting
We examined whether the ALS-associated mutation hSOD1G93A had a direct contribution to mitochondrial dysfunction in both muscle and bone osteocyte MLO-Y4 cells by overexpressing mitochondrion-targeted hSOD1G93A
Seahorse mitochondrial respiratory function assessment, and the quantification of time-dependent mRNA and protein levels in NSC34-G93A cells, we revealed significantly enhanced spare respiratory capacity following two days of butyrate incubation

Summary

Introduction

Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease characterized by progressive motor neuron loss and severe skeletal muscle wasting. Two FDA-approved therapies (Riluzole and Radicava) only extend the life span by a few months, while the progressive skeletal muscle paralysis in ALS usually affects respiratory function, frequently leading to ventilatory failure and death in 3–5 years following the disease diagnosis. Butyrate has shown promising outcomes in alleviating disease progression in an ALS mouse model overexpressing the human ALS mutation. Most cases of ALS are sporadic (SALS), with about 10% being familial (FALS). While diverse factors contribute to sporadic and familial ALS pathogenesis, there are commonly shared pathological and clinical features in all ALS cases, suggesting that different initiating causes lead to a mechanistically similar neurodegenerative pathway [3,4].

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