@article{DelfanVahedBishopetal.2022, author = {Delfan, Maryam and Vahed, Alieh and Bishop, David and Juybari, Raheleh Amadeh and Laher, Ismail and Saeidi, Ayoub and Granacher, Urs and Zouhal, Hassane}, title = {Effects of two workload-matched high-intensity interval training protocols on regulatory factors associated with mitochondrial biogenesis in the soleus muscle of diabetic rats}, series = {Frontiers in Physiology}, journal = {Frontiers in Physiology}, publisher = {Frontiers}, address = {Lausanne, Schweiz}, issn = {1664-042X}, doi = {10.3389/fphys.2022.927969}, pages = {1 -- 12}, year = {2022}, abstract = {Aims: High intensity interval training (HIIT) improves mitochondrial characteristics. This study compared the impact of two workload-matched high intensity interval training (HIIT) protocols with different work:recovery ratios on regulatory factors related to mitochondrial biogenesis in the soleus muscle of diabetic rats. Materials and methods: Twenty-four Wistar rats were randomly divided into four equal-sized groups: non-diabetic control, diabetic control (DC), diabetic with long recovery exercise [4-5 × 2-min running at 80\%-90\% of the maximum speed reached with 2-min of recovery at 40\% of the maximum speed reached (DHIIT1:1)], and diabetic with short recovery exercise (5-6 × 2-min running at 80\%-90\% of the maximum speed reached with 1-min of recovery at 30\% of the maximum speed reached [DHIIT2:1]). Both HIIT protocols were completed five times/week for 4 weeks while maintaining equal running distances in each session. Results: Gene and protein expressions of PGC-1α, p53, and citrate synthase of the muscles increased significantly following DHIIT1:1 and DHIIT2:1 compared to DC (p ˂ 0.05). Most parameters, except for PGC-1α protein (p = 0.597), were significantly higher in DHIIT2:1 than in DHIIT1:1 (p ˂ 0.05). Both DHIIT groups showed significant increases in maximum speed with larger increases in DHIIT2:1 compared with DHIIT1:1. Conclusion: Our findings indicate that both HIIT protocols can potently up-regulate gene and protein expression of PGC-1α, p53, and CS. However, DHIIT2:1 has superior effects compared with DHIIT1:1 in improving mitochondrial adaptive responses in diabetic rats.}, language = {en} } @article{WeiFrankeOstetal.2020, author = {Wei, Xiaoyan and Franke, Julia and Ost, Mario and Wardelmann, Kristina and B{\"o}rno, Stefan and Timmermann, Bernd and Meierhofer, David and Kleinridders, Andre and Klaus, Susanne and Stricker, Sigmar}, title = {Cell autonomous requirement of neurofibromin (Nf1) for postnatal muscle hypertrophic growth and metabolic homeostasis}, series = {Journal of cachexia, sarcopenia and muscle}, volume = {11}, journal = {Journal of cachexia, sarcopenia and muscle}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {2190-5991}, doi = {10.1002/jcsm.12632}, pages = {1758 -- 1778}, year = {2020}, abstract = {Background Neurofibromatosis type 1 (NF1) is a multi-organ disease caused by mutations in neurofibromin 1 (NF1). Amongst other features, NF1 patients frequently show reduced muscle mass and strength, impairing patients' mobility and increasing the risk of fall. The role of Nf1 in muscle and the cause for the NF1-associated myopathy are mostly unknown. Methods To dissect the function ofNf1in muscle, we created muscle-specific knockout mouse models for NF1, inactivatingNf1in the prenatal myogenic lineage either under the Lbx1 promoter or under the Myf5 promoter. Mice were analysed during prenatal and postnatal myogenesis and muscle growth. Results Nf1(Lbx1)and Nf1(Myf5)animals showed only mild defects in prenatal myogenesis. Nf1(Lbx1)animals were perinatally lethal, while Nf1(Myf5)animals survived only up to approximately 25 weeks. A comprehensive phenotypic characterization of Nf1(Myf5)animals showed decreased postnatal growth, reduced muscle size, and fast fibre atrophy. Proteome and transcriptome analyses of muscle tissue indicated decreased protein synthesis and increased proteasomal degradation, and decreased glycolytic and increased oxidative activity in muscle tissue. High-resolution respirometry confirmed enhanced oxidative metabolism in Nf1(Myf5)muscles, which was concomitant to a fibre type shift from type 2B to type 2A and type 1. Moreover, Nf1(Myf5)muscles showed hallmarks of decreased activation of mTORC1 and increased expression of atrogenes. Remarkably, loss of Nf1 promoted a robust activation of AMPK with a gene expression profile indicative of increased fatty acid catabolism. Additionally, we observed a strong induction of genes encoding catabolic cytokines in muscle Nf1(Myf5)animals, in line with a drastic reduction of white, but not brown adipose tissue. Conclusions Our results demonstrate a cell autonomous role for Nf1 in myogenic cells during postnatal muscle growth required for metabolic and proteostatic homeostasis. Furthermore, Nf1 deficiency in muscle drives cross-tissue communication and mobilization of lipid reserves.}, language = {en} }