Cultured Myoblasts Derived from Rat Soleus Muscle Show Altered Regulation of Proliferation and Myogenesis during the Course of Mechanical Unloading

Abstract

The structure and function of soleus muscle fibers undergo substantial remodeling under real or simulated microgravity conditions. However, unloading-induced changes in the functional activity of skeletal muscle primary myoblasts remain poorly studied. The purpose of our study was to investigate how short-term and long-term mechanical unloading would affect cultured myoblasts derived from rat soleus muscle. Mechanical unloading was simulated by rat hindlimb suspension model (HS). Myoblasts were purified from rat soleus at basal conditions and after 1, 3, 7, and 14 days of HS. Myoblasts were expanded in vitro, and the myogenic nature was confirmed by their ability to differentiate as well as by immunostaining/mRNA expression of myogenic markers. The proliferation activity at different time points after HS was analyzed, and transcriptome analysis was performed. We have shown that soleus-derived myoblasts differently respond to an early and later stage of HS. At the early stage of HS, the proliferative activity of myoblasts was slightly decreased, and processes related to myogenesis activation were downregulated. At the later stage of HS, we observed a decrease in myoblast proliferative potential and spontaneous upregulation of the pro-myogenic program.

Mechanism of GLP-1 Receptor Agonists-Mediated Attenuation of Palmitic Acid-Induced Lipotoxicity in L6 Myoblasts

“…These results suggest that LR can effectively improve the IR state of L6 myoblasts induced by PA, which may be related to the improvement of intracellular TG content. In this study, skeletal muscle myoblasts are used as the research object, and the research is carried out by differentiating myoblasts into mature skeletal muscle cells, because mature skeletal muscle cells lose their ability to divide and are difficult to culture [16][17][18][19]. In skeletal muscle cells, FAT/CD36 is the main membrane protein that promotes fatty acid transport, a process related to the metabolic stress signal cascade [9].…”

“…In skeletal muscle cells, FAT/CD36 is the main membrane protein that promotes fatty acid transport, a process related to the metabolic stress signal cascade [9]. The binding of FABP4 to fatty acids in the cytoplasm regulates the rate of lipid uptake throughout the KPL corporation, USA Goat anti-rabbit secondary antibody (1∶5000) KPL corporation, USA transmembrane transport system [16]. In a previous study [17], LR was found to reduce the TG and long-chain fatty acyl-CoA content in skeletal muscle cells of high-fat-fed rats in a concentration-dependent manner.…”

AMPK Phosphorylation Impacts Apoptosis in Differentiating Myoblasts Isolated from Atrophied Rat Soleus Muscle

“…Euthanasia of animals was performed by decapitation under isoflurane anesthesia. Isolation of SCs/myoblasts from the soleus muscle was performed as described in our previous paper [ 23 ]. Following isolation, more than 90% of the isolated cells expressed Pax7 ( Figure 1 b).…”

“…mRNA expression of target genes was determined by reverse transcription polymerase chain reaction (RT-PCR) as described in our previous study [ 23 ]. Primer sequences are provided in Table 1 .…”

“…Niesler et al (2007) have shown that some level of AMPK activity is needed to inhibit apoptotic processes in differentiated C2C12 myotubes [ 22 ]. Moreover, we have recently found an accelerated differentiation and myotube formation in primary myoblasts derived from rat soleus muscles that were exposed to mechanical unloading prior [ 23 ]. We also observed decreased phosphorylation levels of acetyl-CoA carboxylase (ACC), a marker of AMPK activity, in rat soleus-derived myoblasts at later stages (5 days) of differentiation [ 24 ].…”