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. 2024 Jan 20;14(1):1780.
doi: 10.1038/s41598-024-52198-x.

Peroxisome proliferator-activated receptor γ coactivator 1α regulates downstream of tyrosine kinase-7 (Dok-7) expression important for neuromuscular junction formation

Takumi Sugimoto #  1 , Chihiro Sakamaki #  1 , Tokushi Kimura  1 , Takahiro Eguchi  2 , Shinji Miura  3 , Yasutomi Kamei  4
Affiliations

Peroxisome proliferator-activated receptor γ coactivator 1α regulates downstream of tyrosine kinase-7 (Dok-7) expression important for neuromuscular junction formation

Takumi Sugimoto et al. Sci Rep. .

Abstract

The neuromuscular junction (NMJ)-formed between a motor nerve terminal and skeletal muscle fiber-plays an important role in muscle contraction and other muscle functions. Aging and neurodegeneration worsen NMJ formation and impair muscle function. Downstream of tyrosine kinase-7 (Dok-7), expressed in skeletal muscle fibers, is essential for the formation of NMJ. Exercise increases the expression of the transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) in skeletal muscles and restores NMJ formation. In this study, we used skeletal muscle-specific PGC1α knockout or overexpression mice to examine the role of PGC1α in regulating Dok-7 expression and NMJ formation. Our findings revealed that Dok-7 expression is regulated by PGC1α, and luciferase activity of the Dok-7 promoter is greatly increased by coexpressing PGC1α and estrogen receptor-related receptor α. Thus, we suggest PGC1α is involved in exercise-mediated restoration of NMJ formation.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Reduced downstream of tyrosine kinase-7 (Dok-7) gene expression in skeletal muscle-specific peroxisome proliferator-activated receptor γ coactivator 1α knockout (PGC1α-mKO) mice. (a, b) Gene expression analysis of the gastrocnemius muscle from 8-week-old male mice and 22- to 29-month-old female mice using quantitative real-time PCR (N = 13). Data were normalized to 36B4 expression and expressed relative to wild-type (WT) mice. (c) AChR staining of the extensor digitorum longus muscle. Representative images are shown in each group (N = 9). Scale bar = 15 µm. (d) The size (area) of AChR clusters was quantified (N = 9). The values are shown as the mean ± SE. The coefficients of variation are shown in Supplementary Table 2.
Figure 2
Figure 2
Increased downstream of tyrosine kinase-7 (Dok-7) gene expression in skeletal muscle-specific peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) overexpression (PGC1α-mTg) mice. (a, b) Gene expression in the gastrocnemius muscle of 10–12-week-old male mice and 8-week-old female mice was analyzed using quantitative real-time PCR (N = 11). Data were normalized to 36B4 expression and expressed relative to wild-type (WT) mice. (c) AChR staining of the extensor digitorum longus muscle. Representative images are shown in each group (N = 8 or 9). Scale bar = 15 µm. (d) The area of AChR clusters was quantified (N = 8 or 9). Values are shown as the mean ± SE. The coefficients of variation are shown in Supplementary Table 2.
Figure 3
Figure 3
Increased peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and downstream of tyrosine kinase-7 (Dok-7) expression in the skeletal muscle of after exercise. (a, b) Gene expression in the gastrocnemius muscle of 9-week-old male mice and female mice was analyzed using quantitative real-time PCR (N = 12 or 14). Data were normalized to 36B4 expression and expressed relative to sedentary mice (sed). The coefficients of variation are shown in Supplementary Table 2. The values are shown as the mean ± SE. (c–e) The online tool MetaMEx was used to investigate the expression of Dok-7 through various exercises. The forest plot obtained from this analysis was displayed.
Figure 3
Figure 3
Increased peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and downstream of tyrosine kinase-7 (Dok-7) expression in the skeletal muscle of after exercise. (a, b) Gene expression in the gastrocnemius muscle of 9-week-old male mice and female mice was analyzed using quantitative real-time PCR (N = 12 or 14). Data were normalized to 36B4 expression and expressed relative to sedentary mice (sed). The coefficients of variation are shown in Supplementary Table 2. The values are shown as the mean ± SE. (c–e) The online tool MetaMEx was used to investigate the expression of Dok-7 through various exercises. The forest plot obtained from this analysis was displayed.
Figure 4
Figure 4
Downstream of tyrosine kinase-7 (Dok-7) gene expression regulated by peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) in vitro. (a, b) PGC1α was knocked down in muscle satellite cells. (c, d) PGC1α was overexpressed in muscle satellite cells. Gene expression was analyzed in gastrocnemius muscle-derived satellite cells using quantitative real-time PCR (a, b: N = 4; c, d: N = 3). Data were normalized to 36B4 expression and expressed relative to si control (si Ctr) or GFP. The values are shown as the mean ± SE.
Figure 5
Figure 5
Downstream of tyrosine kinase-7 (Dok-7) expression is influenced by peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and estrogen receptor-related receptor α (ERRα). The effect of increasing PGC1α and ERRα expression was examined by cotransfecting HEK293T cells with a reporter plasmid. (a) The constructs include a 2000 bp genomic promoter region and the first exon of the Dok-7 gene (− 2000 bp to + 73 bp, from the transcription start site) and the luciferase reporter gene (N = 4). The values are represented as the mean ± SE. (b) XCT790 was added to the PGC1α- overexpressing muscle satellite cells. Gene expression in gastrocnemius muscle-derived satellite cells was analyzed using quantitative real-time PCR (N = 3). Data were normalized to 36B4 expression and expressed relative to PGC1α (−) and XCT790 (−). The values are shown as the mean ± SE.
Figure 6
Figure 6
Gene expression of downstream of tyrosine kinase-7 (Dok-7) is regulated by peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) and estrogen receptor-related receptor α (ERRα). Regulation of increased Dok-7 expression and neuromuscular junction (NMJ) formation by PGC1α and ERRα. PGC1α is increased by exercise and functions as a transcriptional coactivator of nuclear receptors. PGC1α and ERRα work together to increase Dok-7 expression.
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References

    1. Jang YC, Van Remmen H. Age-associated alterations of the neuromuscular junction. Exp. Gerontol. 2011;46:193–198. doi: 10.1016/j.exger.2010.08.029. - DOI - PMC - PubMed
    1. Valdez G, Tapia JC, Lichtman JW, Fox MA, Sanes JR. Shared resistance to aging and ALS in neuromuscular junctions of specific muscles. PLoS One. 2012;7:e34640. doi: 10.1371/journal.pone.0034640. - DOI - PMC - PubMed
    1. Rudolf R, Khan MM, Labeit S, Deschenes MR. Degeneration of neuromuscular junction in age and dystrophy. Front. Aging Neurosci. 2014;6:99. doi: 10.3389/fnagi.2014.00099. - DOI - PMC - PubMed
    1. Bao Z, et al. AChRs degeneration at NMJ in aging-associated sarcopenia-a systematic review. Front. Aging Neurosci. 2020;12:597811. doi: 10.3389/fnagi.2020.597811. - DOI - PMC - PubMed
    1. Inoue A, et al. Dok-7 activates the muscle receptor kinase MuSK and shapes synapse formation. Sci. Signal. 2009;2:ra7. doi: 10.1126/scisignal.2000113. - DOI - PubMed

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