Single-nucleus transcriptomic analysis reveals the regulatory circuitry of myofiber XBP1 during regenerative myogenesis

• Published in: iScience 2024-12, Vol.27 (12), p.111372, Article 111372
• Main Authors: Joshi, Aniket S., Castillo, Micah B., Tomaz da Silva, Meiricris, Vuong, Anh Tuan, Gunaratne, Preethi H., Darabi, Radbod, Liu, Yu, Kumar, Ashok
• Format: Article
• Language: English
• Subjects: Biochemistry; Cell biology; Genetics; Transcriptomics
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2024.111372

Endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) is activated in skeletal muscle under multiple conditions. However, the role of the UPR in the regulation of muscle regeneration remains less understood. We demonstrate that gene expression of various markers of the UPR is induced in both myogenic and non-myogenic cells in regenerating muscle. Genetic ablation of X-box binding protein 1 (XBP1), a downstream target of the Inositol requiring enzyme 1α (IRE1α) arm of the UPR, in myofibers attenuates muscle regeneration in adult mice. Single nucleus RNA sequencing (snRNA-seq) analysis showed that deletion of XBP1 in myofibers perturbs proteolytic systems and mitochondrial function in myogenic cells. Trajectory analysis of snRNA-seq dataset showed that XBP1 regulates the abundance of satellite cells and the formation of new myofibers in regenerating muscle. In addition, ablation of XBP1 disrupts the composition of non-myogenic cells in injured muscle microenvironment. Collectively, our study suggests that myofiber XBP1 regulates muscle regeneration through both cell-autonomous and -non-autonomous mechanisms. [Display omitted] •The UPR is activated in different cell types during muscle regeneration•Targeted deletion of XBP1 impairs muscle regeneration in adult mice•Myofiber XBP1 regulates satellite cell dynamics during regenerative myogenesis•Myofiber XBP1 regulates the abundance of non-myogenic cells in regenerating skeletal muscle Biochemistry; Genetics; Cell biology; Transcriptomics