Exosome-mediated regulatory mechanisms in skeletal muscle: a narrative review / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Skeletal muscle plays a paramount role in physical activity, metabolism, and energy balance, while its homeostasis is being challenged by multiple unfavorable factors such as injury, aging, or obesity. Exosomes, a subset of extracellular vesicles, are now recognized as essential mediators of intercellular communication, holding great clinical potential in the treatment of skeletal muscle diseases. Herein, we outline the recent research progress in exosomal isolation, characterization, and mechanism of action, and emphatically discuss current advances in exosomes derived from multiple organs and tissues, and engineered exosomes regarding the regulation of physiological and pathological development of skeletal muscle. These remarkable advances expand our understanding of myogenesis and muscle diseases. Meanwhile, the engineered exosome, as an endogenous nanocarrier combined with advanced design methodologies of biomolecules, will help to open up innovative therapeutic perspectives for the treatment of muscle diseases.

The Roles and Mechanisms of SERCA in Skeletal Muscle / 中国生物化学与分子生物学报

Skeletal muscle is an important organ for development and metabolism and its metabolic disor⁃ ders will induce a series of muscle diseases. As an important regulator of the muscle contraction process, Ca

Effects of Competing Endogenous RNA on Proliferation and Differentiation of Skeletal Muscle Cells / 中国生物化学与分子生物学报

The skeletal muscle is an important part of the animal body, which is closely related to body movement, energy consumption, production performance and its development process is regulated by many factors. The molecular mechanism of skeletal muscle growth and development is not only closely related to animal husbandry production, but also provides a theoretical basis for the treatment of muscle dis-eases, such as amyotrophic muscular dystrophy, and so on. Non-coding RNA (ncRNA) is a kind of RNA without coding ability, in which circular RNA (circRNA), long non-coding RNA (lncRNA) and micro RNA (miRNA) have been proved to play an important role in the development of skeletal muscles. miR-NA can specifically bind to the 3′ untranslated region (3′ UTR) of the target gene through its seed se-quence, so as to inhibit the translation process of the target gene or directly degrade the target gene, and become a prominent participant in a variety of biological processes. Studies have shown that circRNA, ln-cRNA, pseudogenes and mRNA with miRNA response elements (MRE) can competitively combine miRNA to regulate gene expression, forming a competing endogenous RNA (ceRNA) regulatory network model. This hypothesis subverts the previous concept of unidirectional regulation of target genes by miRNA, and endows them with new biological functions in transcriptome, which is of great biological significance. In recent years, it has been found that ceRNA plays an important regulatory role in the growth and development of skeletal muscles. This paper reviews the role of miRNA, lncRNA and circRNA in the proliferation and differentiation of animal skeletal muscle cells, which is an important member of ceRNA mechanism, in order to broaden the research direction of skeletal muscle mechanism and provide new ideas for the development of animal husbandry and the treatment of muscle diseases.

Over-expression of FoxO1 inhibits the differentiation of porcine skeletal muscle myoblast / 生物工程学报

The Forkhead box O1 (FoxO1) transcription factor governs muscle growth, metabolism and cell differentiation. However, its role in myoblast differentiation is unclear. To study the biological function of FoxO1 during differentiation in porcine primary myoblast, we constructed stably FoxO1 over-expressed porcine myoblast mediated by liposome and adopted morphological observation, quantitative real-time RT-PCR and Western blotting methods to analyze FoxO1 and early and late myogenic regulation factors MyoD and myogenin expression. During differentiation the mRNA level of FoxO1 was significantly increased. However, the total protein did not change but the phosphorylation of FoxO1 was upregulated. Furthermore, overexpression of FoxO1 in porcine myoblast decreased MyoD and myogenin mRNA, whereas MyoD protein changed little and myogenin was significantly suppressed (P < 0.05). These results indicated that FoxO1 delays and negatively regulates the porcine myoblast differentiation. Moreover, FoxO1 may play a critical role in muscle fiber-type specification through the inhibition of myogenic regulation factors.