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Biology subjects

Jannig, P. R.

Publications and source records attributed to Jannig, P. R..

3 recordsLinked to original sources

The mitochondrial mRNA stabilizing protein, SLIRP, regulates skeletal muscle mitochondrial structure and respiration by exercise-recoverable mechanisms

Summary and graphical abstractDecline in mitochondrial function associates with decreased muscle mass and strength in multiple conditions, including sarcopenia and type 2 diabetes. Optimal treatment could include improving mitochondrial function, however, there are limited and equivocal data regarding the molecular cues controlling muscle mitochondrial plasticity. Here we uncover the mitochondrial-mRNA-stabilizing protein SLIRP, in complex with LRPPRC, as a PGC-1 target that regulates mitochondrial structure, respiration, and mitochondrially-encoded-mRNA pools in skeletal muscle. Exercise training effectively counteracted mitochondrial defects induced by loss of LRPPRC/SLIRP, despite sustained low mitochondrially-encoded-mRNA pools, via increased mitoribosome translation capacity. In humans, exercise training robustly increased muscle SLIRP and LRPPRC protein content across exercise modalities and sexes, yet this increase was less prominent in subjects with type 2 diabetes. Our work identifies a mechanism of post-transcriptional mitochondrial regulation in skeletal muscle through mitochondrial mRNA stabilization. It emphasizes exercise as an effective approach to alleviate mitochondrial defects by possibly increasing mitoribosome capacity. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/564600v2_ufig1.gif" ALT="Figure 1"> View larger version (61K): org.highwire.dtl.DTLVardef@1cdc6c5org.highwire.dtl.DTLVardef@b4cb1borg.highwire.dtl.DTLVardef@182871corg.highwire.dtl.DTLVardef@7462ea_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

Zfp697 is an RNA-binding protein that regulates skeletal muscle inflammation and regeneration.

Muscular atrophy is a mortality risk factor that happens with disuse, chronic disease, and aging. Recovery from atrophy requires changes in several cell types including muscle fibers, and satellite and immune cells. Here we show that Zfp697/ZNF697 is a damage-induced regulator of muscle regeneration, during which its expression is transiently elevated. Conversely, sustained Zfp697 expression in mouse muscle leads to a gene expression signature of chemokine secretion, immune cell recruitment, and extracellular matrix remodeling. Myofiber-specific Zfp697 ablation hinders the inflammatory and regenerative response to muscle injury, compromising functional recovery. We uncover Zfp697 as an essential interferon gamma mediator in muscle cells, interacting primarily with ncRNAs such as the pro-regenerative miR-206. In sum, we identify Zfp697 as an integrator of cell-cell communication necessary for tissue regeneration. One Sentence SummaryZfp697 is necessary for interferon gamma signaling and muscle regeneration.

physiology↗

Muscle-secreted neurturin couples myofiber oxidative metabolism and slow motor neuron identity.

Endurance exercise promotes skeletal muscle vascularization, oxidative metabolism, fiber-type switching, and neuromuscular junction integrity. Importantly, the metabolic and contractile properties of the muscle fiber must be coupled to the identity of the innervating motor neuron (MN). Here, we show that muscle-derived neurturin (NRTN) acts on muscle fibers and MNs to couple their characteristics. Using a muscle-specific NRTN transgenic mouse (HSA-NRTN) and RNA-sequencing of MN somas, we observed that retrograde NRTN signaling promotes a shift towards a slow MN identity. In muscle, NRTN increased capillary density, oxidative capacity, and induced a transcriptional reprograming favoring fatty acid metabolism over glycolysis. This combination of effects on muscle and MNs, makes HSA-NRTN mice lean with remarkable exercise performance and motor coordination. Interestingly, HSA-NRTN mice largely recapitulate the phenotype of mice with muscle-specific expression of its upstream regulator PGC-11. This work identifies NRTN as a myokine that couples muscle oxidative capacity to slow MN identity. HIGHLIGHTSO_LINRTN is a myokine induced by physical exercise. C_LIO_LIMuscle-derived NRTN promotes a slow motor neuron identity. C_LIO_LIMuscle-derived NRTN enhances muscle oxidative metabolism. C_LIO_LINRTN improves systemic metabolism, exercise performance and motor coordination. C_LI

physiology↗