Wang Yi, Gao Juan, Fan Bojun, Hu Yuemin, Yang Yuefei, Wu Yajie, Zhu Jiaqiao, Li Junwei, Li Feng, Ju Huiming
College of Veterinary Medicine, Yangzhou University/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou 225009, China.
Department of Reproductive Medicine Center, Northern Jiangsu People's Hospital Affiliated to Yangzhou University/Clinical Medical College, Yangzhou University, Yangzhou 225009, China.
Vet Sci. 2024 Dec 30;12(1):11. doi: 10.3390/vetsci12010011.
This study investigated the effects of long-term serum starvation on autophagy, metabolism, and differentiation of porcine skeletal muscle satellite cells (SMSCs) and elucidated the role of autophagy in skeletal muscle development. Our findings provide a theoretical basis for improving meat production in domestic pigs. The SMSCs isolated and preserved in our laboratory were revived and divided into six groups based on the culture medium serum concentration to simulate varying levels of serum starvation: 20% serum (control group), 15% serum (mild serum starvation group), 5% serum (severe serum starvation group), and their autophagy inhibition groups supplemented with 3-methyladenine. After 96 h of culture, the apoptosis rate, mitochondrial membrane potential, reactive oxygen species, and ATP were measured to evaluate the effects of serum starvation on the SMSCs' metabolism. Additionally, the levels of autophagy-related proteins, autophagosomes, and autolysosomes were measured to investigate the impact of long-term serum starvation on autophagy. The expression of proteins associated with myogenic and adipogenic differentiation (MHC, MyoD1, peroxisome proliferator-activated receptor , and lipoprotein lipase) as well as lipid content were also determined to investigate the effects of long-term serum starvation on SMSC differentiation. The results showed that long-term serum starvation induced autophagy through the AMPK/mTOR signaling pathway, accelerated cell metabolism and apoptosis, exacerbated reactive oxygen species accumulation, and inhibited myogenic and adipogenic differentiation of SMSCs. Moreover, these effects were positively correlated with the level of serum starvation. In addition, serum starvation-induced autophagy moderately promoted the myogenic and adipogenic differentiation of SMSCs; however, these effects were insufficient to counteract the inhibition of cell differentiation by long-term serum starvation. This study provides insight into leveraging serum starvation as a stressor to regulate muscle growth and metabolism in domestic pigs.
本研究调查了长期血清饥饿对猪骨骼肌卫星细胞（SMSC）自噬、代谢和分化的影响，并阐明了自噬在骨骼肌发育中的作用。我们的研究结果为提高家猪的肉类产量提供了理论依据。将在我们实验室分离并保存的SMSC复苏，并根据培养基血清浓度分为六组，以模拟不同程度的血清饥饿：20%血清（对照组）、15%血清（轻度血清饥饿组）、5%血清（重度血清饥饿组），以及添加3-甲基腺嘌呤的自噬抑制组。培养96小时后，测量凋亡率、线粒体膜电位、活性氧和ATP，以评估血清饥饿对SMSC代谢的影响。此外，测量自噬相关蛋白、自噬体和自溶酶体的水平，以研究长期血清饥饿对自噬的影响。还测定了与肌源性和脂肪源性分化相关的蛋白（肌球蛋白重链、肌分化抗原1、过氧化物酶体增殖物激活受体和脂蛋白脂肪酶）的表达以及脂质含量，以研究长期血清饥饿对SMSC分化的影响。结果表明，长期血清饥饿通过AMPK/mTOR信号通路诱导自噬，加速细胞代谢和凋亡，加剧活性氧积累，并抑制SMSC的肌源性和脂肪源性分化。此外，这些影响与血清饥饿程度呈正相关。此外，血清饥饿诱导的自噬适度促进了SMSC的肌源性和脂肪源性分化；然而，这些影响不足以抵消长期血清饥饿对细胞分化的抑制作用。本研究为利用血清饥饿作为应激源来调节家猪的肌肉生长和代谢提供了见解。
