The effects of temperature and donor piglet age on the transcriptomic profile and energy metabolism of myoblasts

Abstract

Rapid climate change is associated with frequent extreme heat events and the resulting thermal stress has consequences for the health, welfare, and growth of farm animals. The aim of this study was to characterize the transcriptional changes and the effects on energy metabolism in proliferating porcine myoblasts derived from piglets of different ages, representing differences in thermoregulatory abilities, and cultivated below (35°C) and above (39°C, 41°C) the standard cultivation temperature (37°C). Satellite cells originating from Musculus rhomboideus of piglets isolated on days 5 (P5, thermolabile) and 20 (P20, thermostable) of age were used. Our expression analyses highlighted differentially expressed genes in porcine myoblasts cultures under heat or cold induced stress. These gene sets showed enrichment for biological processes and pathways related to organelle fission, cell cycle, chromosome organization, and DNA replication. Culture at 35°C resulted in increased metabolic flux as well as a greater abundance of transcripts of the cold shock protein-encoding gene RBM3 and those of genes related to biological processes and signaling pathways, especially those involving the immune system (cytokine–cytokine receptor interaction, TNF and IL-17 signaling pathways). For cultivation at 39°C, differences in the expression of genes related to DNA replication and cell growth were identified. The highest glutathione index ratio was also found under 39°C. Meanwhile, cultivation at 41°C induced a heat stress response, including the upregulation of HSP70 expression and the downregulation of many biological processes and signaling pathways related to proliferative ability. Our analysis also identified differentially expressed genes between cells of donors with a not yet (P5) and already fully developed (P20) capacity for thermoregulation at different cultivation temperatures. When comparing P5 and P20, most of the changes in gene expression were detected at 37°C. At this optimal temperature, muscle cells can develop to their full capacity. Therefore, the most diverse molecular signaling pathways, including PI3K-Akt signaling, Wnt signaling, and EGFR tyrosine kinase inhibitor, were found and are more pronounced in muscle cells from 20-day-old piglets. These results contribute to a better understanding of the mechanisms underlying the adaptation of skeletal muscle cells to temperature stress in terms of their thermoregulatory ability.

Heat stress inhibits the proliferation and differentiation of myoblasts and is associated with damage to mitochondria

“…Heat stress impaired mitochondrial biogenesis and function, thereby reducing the expression of PAX7, MYOD, MYF5, MYOG and MYHC, which might be the Frontiers in Cell and Developmental Biology frontiersin.org reason for the inhibition of proliferation and differentiation in myoblasts. Metzger et al (2022) demonstrated that the biological processes and signaling pathways correlated with proliferation were downregulated in porcine myoblasts under heat stress (41 °C) (Metzger et al, 2022), and Chen et al ( 2020) reported that heat stress (42 °C) interfered the myogenic differentiation via changing the expression of MYOD, MYOG and MYHC (Chen et al, 2020), which is consistent with our results. Cell migration, proliferation and differentiation have profound effects on the development of skeletal muscle (Ye et al, 2020).…”

“…We observed the increased expression levels of HSP60, HSP70 and HSP110 in the heat-stressed myoblasts during proliferation and differentiation, which indicated that the myoblasts suffered from severe heat stress. Metzger et al (2022) reported that heat stress (41 °C) upregulated the expression of HSP70 in porcine myoblasts (Metzger et al, 2022). The development of skeletal muscle is an extraordinarily complicated and delicate process, which includes the proliferation and differentiation of the satellite cells (Reed et al, 2022).…”

“…We observed the increased expression levels of HSP60, HSP70 and HSP110 in the heat-stressed myoblasts during proliferation and differentiation, which indicated that the myoblasts suffered from severe heat stress. Metzger et al (2022) reported that heat stress (41°C) upregulated the expression of HSP70 in porcine myoblasts ( Metzger et al, 2022 ).…”

Exploration of Potential Target Genes of miR-24-3p in Chicken Myoblasts by Transcriptome Sequencing Analysis

“…Cui et al [ 48 ] found that focal adhesion was closely associated with the growth of embryonic skeletal muscle in chickens. Metzger et al [ 49 ] discovered that cytokine–cytokine receptor interaction was involved in myoblasts proliferating derived from piglets of different ages. We have found no previous studies on the relationship between Salmonella infection and skeletal muscle development.…”

Transcriptomic Response of Differentiating Porcine Myotubes to Thermal Stress and Donor Piglet Age

“…These proteins cooperate to establish the muscle phenotype by regulating proliferation, irreversible cell cycle arrest, and regulated transcription of sarcomeric and muscle-specific genes for differentiation and sarcomere formation [13]. Our previous research highlighted the differential expression of numerous genes in porcine myoblast cultures subjected to heat or cold stress, with these transcripts linked to a range of biological processes and signaling pathways [14]. Notably, the majority of molecular changes occurred at the control temperature of 37 • C, which is the standard cultivation temperature for porcine muscle cell cultures and appropriate for comparing myoblast cells from piglet donors that are still developing their thermoregulatory capabilities under temperature stress [14].…”