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Abstract Aging and obesity pose significant threats to public health and are major contributors to muscle atrophy. The trends in muscle fiber types under these conditions and the transcriptional differences between different muscle fiber types remain unclear. Here, we demonstrate distinct responses of fast/glycolytic fibers and slow/oxidative fibers to aging and obesity. We found that in muscles dominated by oxidative fibers, the proportion of oxidative fibers remains unchanged during aging and obesity. However, in muscles dominated by glycolytic fibers, despite the low content of oxidative fibers, a significant decrease in proportion of oxidative fibers was observed. Consistently, our study uncovered that during aging and obesity, fast/glycolytic fibers specifically increased the expression of genes associated with muscle atrophy and inflammation, including Dkk3, Ccl8, Cxcl10, Cxcl13, Fbxo32, Depp1, and Chac1, while slow/oxidative fibers exhibit elevated expression of antioxidant protein Nqo-1 and downregulation of Tfrc. Additionally, we noted substantial differences in the expression of calcium-related signaling pathways between fast/glycolytic fibers and slow/oxidative fibers in response to aging and obesity. Treatment with a calcium channel inhibitor thapsigargin significantly increased the abundance of oxidative fibers. Our study provides additional evidence to support the transcriptomic differences in muscle fiber types under pathophysiological conditions, thereby establishing a theoretical basis for modulating muscle fiber types in disease treatment.

To study the seed dormancy and germination mechanism of Xanthoceras sorbifolium, the seeds of four cultivars [‘Putong’(PT),‘Qihong’(QH), ‘Wofeng’(WF) and‘Woshi’(WS)] were stored at -20 ℃ for different periods (30, 60, 90, 120, 150 d). The seed germination indexes were determined in each treatment, and the changes of reserve substance and hormone content were also analyzed in three stages including before storage, after storage, and 7 days of germination. The results were as follows: (1) Cold storage could significantly promote the germination rate and germination potential of small seeds (PT, QH). The best treatment was cold storage for 60 d, and the germination rate was up to 48.3% and 58.3%, respectively. The effects of cold storage on large seeds (WF and WS) was lower than that of small seeds. (2) The kernel oil content, seed shell thickness (SST) in four cultivar seeds all decreased significantly during periods of cold storage and germination, especially in 3-7 days of germination, the oil content and SST (except WS cultivar) decreased notably. However, water content in kernels increased rapidly within 1-3 days of germination and then slowly increased to the peak value on the 7th day. The contents of soluble sugar in kernels increased significantly at the 3-4 days of germination. (3) Cold storage increased GA/ABA and tHor/ABA ratios in small seeds (PT, QH), promoted oil degradation, made seed shell thinning and break seed dormancy. In conclusion, the main factors leading to dormancy in X. sorbifolium seeds are larger in size, higher shell thickness and more hardness, physiological post-ripening, and belongs to comprehensive dormancy type. Cold storage at -20 ℃ for 60 d can improve the germination rate of PT, QH and WF seeds, reduces dormancy degree, while the cold storage time of WS seeds needs prolonging to 150 d. The method using -20 ℃ storage with wet sand germination is a rapid and simple method to promote X. sorbifolium seeds germination. This study provides a reference for the promotion of superior varieties and the research on the seed breaking dormancy mechanism in X. sorbifolium.

Abstract Adult skeletal muscle regeneration is mainly driven by muscle stem cells (MuSCs), which are highly heterogeneous. Although recent studies have started to characterize the heterogeneity of MuSCs, whether a subset of cells with distinct exists within MuSCs remains unanswered. Here, we find that a population of MuSCs, marked by Gli1 expression, is required for muscle regeneration. The Gli1+ MuSC population displays advantages in proliferation and differentiation both in vitro and in vivo. Depletion of this population leads to delayed muscle regeneration, while transplanted Gli1+ MuSCs support muscle regeneration more effectively than Gli1− MuSCs. Further analysis reveals that even in the uninjured muscle, Gli1+ MuSCs have elevated mTOR signaling activity, increased cell size and mitochondrial numbers compared to Gli1− MuSCs, indicating Gli1+ MuSCs are displaying the features of primed MuSCs. Moreover, Gli1+ MuSCs greatly contribute to the formation of GAlert cells after muscle injury. Collectively, our findings demonstrate that Gli1+ MuSCs represents a distinct MuSC population which is more active in the homeostatic muscle and enters the cell cycle shortly after injury. This population functions as the tissue-resident sentinel that rapidly responds to injury and initiates muscle regeneration.

Background: Obesity and sarcopenia are both viewed as pathological body composition issues and indicators of compromised nutritional status. The aim of this study was to evaluate the effects of sarcopenic obesity on short- and long-term clinical outcomes. Methods: The clinical data of patients who underwent radical gastrectomy between 2013 and 2019 were prospectively collected. Sarcopenia is defined by European Working Group on Sarcopenia in Older People (EWGSOP2) and obesity is defined by the body mass index (BMI). To identify the independent predictors of postoperative complications and overall survival, we performed univariate and multivariate logistic and Cox regression analyses. Results: In a total of 508 cases, 372 (73.2%) cases were diagnosed with non-sarcopenia, 112 (22.0%) with non-obese sarcopenia, and 24 (4.7%) with sarcopenic obesity. In the multivariate logistic regression, both of non-obese sarcopenia (OR = 2.305, 95% CI = 1.444–3.679, P < 0.001) and sarcopenic obesity (OR = 2.589, 95% CI = 1.088–6.156, P = 0.031) were independent risk factors for postoperative complications. In the multivariate Cox analysis, only non-obese sarcopenia (HR = 2.614, 95% CI = 1.882–3.631, P < 0.001) was independent risk factor for overall survival. Conclusions: Sarcopenic obesity serves as an independent risk factor for postoperative complications, but not for overall survival. [ABSTRACT FROM AUTHOR]