Project description:In this work we employed classic skeletal muscle unloading rat model to determine how hindlimb suspension (HS) affects functional activity of skeletal muscle progenitor cells (SMPC). We have purified SMPC from m. soleus from control rats and after 1, 3, 7 and 14 days of exposure (HS1, HS3, HS7, HS14).
Project description:To investigate the molecular mechanisms governing the transition of skeletal muscle from atrophy to compensatory regeneration and hypertrophy, we employed a mouse model involving hindlimb unloading and subsequent reloading, conducting a comprehensive analysis of global gene expression using RNA-sequencing (RNA-seq). Gastrocnemius muscle samples were obtained from three groups: control mice, mice subjected to 10 days of hindlimb unloading-induced muscle atrophy, and mice reintroduced to normal cage activity for 1 day following the unloading period (reloading).
Project description:Microgravity and prolonged periods of inactivity cause a variety of diseases, including skeletal muscle mass loss and weakening as well as cardiovascular deconditioning. The primary causes of the inadequate preventative measures for these deconditionings are the lack of biomarkers and unknown underlying mechanisms of cardiovascular and skeletal muscle deconditioning in these conditions. Here, we used a hindlimb unloading (HU) mouse model that replicates astronauts in space and bedridden patients to first evaluate cardiovascular and skeletal muscle performance. Serum samples from these mice were used to identify new biomarkers using metabolomic and proteomic approaches. Three weeks of unloading resulted in alterations in cardiovascular system function in C57/Bl6 mice, as measured by changes in mean arterial pressure and heart weight. Unloading for three weeks also altered skeletal muscle function, resulting in a decrease of grip strength in HU mice, as well as skeletal muscle atrophy, as shown by a drop in muscle mass. A two-week recovery time from the unloading condition partially reversed these alterations, stressing the importance of the recovery process.
Project description:Gene expression changes in femur bone induced by acute skeletal muscle unloading, which leads to physiological changes including muscle atrophy, weakness and results in bone remodelling and subsequent loss of bone mass, was investigated by hind-limb suspension (HLS) treatment of Male ICR mice (28–32 g body wt; Harlan, Indianapolis, IN). AgilentTM Whole Mouse Genome Oligo Microarrays were utilised to examine the effects of HLS on mRNA expression profiles of the femur bone in the hindlimbs of freely ambulating control and 24h HLS treated mice. Five independent biological replicates of this experiment were carried out. Five independent biological replicates of this experiment (Control and HLS) were carried out.
Project description:Gene expression changes induced by acute skeletal muscle unloading, which leads to physiological changes including muscle atrophy, fibre-type switching, and loss of ability to transition between lipid and glucose as energy source (metabolic inflexibility), was investigated by hind-limb suspension (HLS) treatment of Male ICR mice (28â32 g body wt; Harlan, Indianapolis, IN). Agilent Whole Mouse Genome Oligo Microarrays were utilised to examine the effects of HLS on mRNA expression profiles of the soleus muscle and the gastrocnemius muscle in the hindlimbs of freely ambulating control and 24h HLS treated mice. Experiment Overall Design: Five independent biological replicates of this experiment (Control and HLS) were carried out.
Project description:Gene expression changes in femur bone induced by acute skeletal muscle unloading, which leads to physiological changes including muscle atrophy, weakness and results in bone remodelling and subsequent loss of bone mass, was investigated by hind-limb suspension (HLS) treatment of Male ICR mice (28–32 g body wt; Harlan, Indianapolis, IN). AgilentTM Whole Mouse Genome Oligo Microarrays were utilised to examine the effects of HLS on mRNA expression profiles of the femur bone in the hindlimbs of freely ambulating control and 24h HLS treated mice. Five independent biological replicates of this experiment were carried out.
Project description:Notch signaling plays essential roles in maintenance of muscle stem cell pool. We found that Notch2, but not Notch1 and Notch3, is expressed in fully differentiated myofibers. To study the specific role of Notch2 in adult myofibers, we generated muscle-specific Notch2-knockout mice. Here, we showed that muscle-specific Notch2 deficiency prevented muscle atrophy induced by hindlimb unloading and diabetes millitus. RNA sequencing analysis revealed that the loss of Notch2 gene in myofibers inhibited gene responses to unloading and diabetes. Especially, several FoxO-target genes and atrogenes were upregulated in wildtype muscles but not in Notch2-deficient muscles by unloading and diabetes. Thus, our characterization of muscle-specific Notch2-knockout mice indicates that Notch2 acts as a regulatory factor of skeletal muscle plasticity and could be a therapeutic target of muscle atrophy.
Project description:Inadequate dietary protein intake causes adverse changes in the morphology and function of skeletal muscle. These changes may be reflected in early alterations in muscle mRNA levels. Microarray analysis was used to assess whether inadequate protein intake differentially affects skeletal muscle transcript levels and expression profiles in older adults. Keywords: dietary intake response
Project description:Gene expression changes induced by acute skeletal muscle unloading, which leads to physiological changes including muscle atrophy, fibre-type switching, and loss of ability to transition between lipid and glucose as energy source (metabolic inflexibility), was investigated by hind-limb suspension (HLS) treatment of Male ICR mice (28–32 g body wt; Harlan, Indianapolis, IN). Agilent Whole Mouse Genome Oligo Microarrays were utilised to examine the effects of HLS on mRNA expression profiles of the soleus muscle and the gastrocnemius muscle in the hindlimbs of freely ambulating control and 24h HLS treated mice. Keywords: treatment vs control, tissue type comparison