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

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.

Distinct transcriptomic profile of satellite cells contributes to preservation of neuromuscular junctions in extraocular muscles of ALS mice

“…Our previous study showed NaBu feeding significantly prolonged the life span of G93A mice and reversed CypD-related mitoflash phenotypes in flexor digitorum brevis myofibers derived from G93A mice, which implies a potential decrease of oxidative stress. Additionally, NaBu treatment also improved mitochondrial respiratory function of NSC34 motor neuron cell line overexpressing hSOD1G93A [30,32,33]. The study here revealed its beneficiary effect on the preservation of NMJ integrity and peri-NMJ SCs during ALS progression.…”

“…Previous studies by our lab and others showed NaBu-supplemented feeding prolongs the life span of G93A mice and reverses CypD-related mitoflash phenotypes in myofibers derived from G93A mice, which implies a potential decrease of oxidative stress. Additionally, NaBu treatment also improved mitochondrial respiratory function of NSC34 motor neuron cell line overexpressing hSOD1G93A [36,79,80]. Yet it was not known whether the beneficiary effects of NaBu are linked to any phenotypic changes of SCs, and whether NaBu treatment induced epigenetic modulations similar to that of EOM SCs.…”

“…Previous studies have shown the epigenetic regulation of SC transcriptome by histone deacetylase (HDAC) inhibitors, such as sodium butyrate (NaBu) [25], could modulate the myogenesis process both in vitro and in vivo [26][27][28][29]. Interestingly, our team recently discovered that feeding G93A mice with NaBu (2% in water) significantly prolonged the life span (~38 days) and ameliorated mitochondrial dysfunction in skeletal muscle and cultured NSC34 motor neurons [30][31][32][33]. It is intriguing to examine whether the beneficiary effect of NaBu is linked with SC behavior changes and whether NaBu treatment produced any epigenetic modulations similar to that of EOM SCs.…”

Synergistic association of resveratrol and histone deacetylase inhibitors as treatment in amyotrophic lateral sclerosis

“…Sodium phenylbutyrate (NaPB) is an inhibitor of HDAC class I and IIa (Kusaczuk et al, 2015). A recent study has shown the beneficial effect of NaPB in improving mitochondrial bioenergetics in a cellular model of ALS (Li et al, 2022). NaPB injected intraperitoneally at the dose of 400 mg/kg/day, prolonged the survival by 21%, ameliorated motor function and promoted expression of anti-apoptotic genes in SOD1(G93A) male mice (Ryu et al, 2005).…”

Microbiota mitochondria disorders as hubs for early age-related macular degeneration

“…Recent studies have shown 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. PGC1α is a master regulator of mitochondrial biogenesis [ 203 ].…”