Journal of Exercise & Organ Cross Talk

Abstract Glioblastoma multiforme (GBM) is a highly aggressive malignant brain tumor with limited treatment options and a poor prognosis. In this study, we aimed to explore the potential effects of resistance training (RT) on the expression relationship between interleukin-6 (IL-6) from skeletal muscle and its interaction with Cathepsin B and Fibronectin type III domain-containing protein 5 (FNDC5) in the hippocampus of rats with GBM. To investigate the role of RT in GBM, we conducted a study using a rat model. By conducting a 4-week RT intervention (three days/week, 30 to 100% of body weight, 3 sets with 4 repetitions/session) and analyzing the expression levels of gastrocnemius muscle IL-6, hippocampal Cathepsin B, and FNDC5, we aimed to shed light on the potential impact of this RT modality on GBM progression. The results showed that GBM induced a significant decrease in gastrocnemius muscle IL-6, hippocampal FNDC5, and Cathepsin B gene expressions that were adjusted by RT. It means that there are significant increases in the GBM+RT group when compared to GBM. There were significant and positive correlations between variables (gastrocnemius muscle IL-6, hippocampal FNDC5, and hippocampal Cathepsin B gene expressions) which led to tissue crosstalk. In conclusion, this study contributes to our understanding of the molecular mechanisms associated with GBM, revealing potential avenues for future therapeutic interventions. RT may serve as a promising approach to modulate the expression relationship between IL-6, Cathepsin B, and FNDC5, offering a potential strategy for improving outcomes in GBM.

Abstract Dear Editor-in-Chief
Many studies have shown that regular physical activity has a significant effect on improving a range of disorders such as metabolic syndrome, cardiovascular disease, and cancer. Regular physical activity improves disease activity in patients by affecting hormones, the reverse cholesterol transport process, factors related to antioxidants and immune defense systems, factors that control cell apoptosis, and more (Myers, Kokkinos, & Nyelin, 2019).
Nowadays, the role of muscle-secreting cytokines (in response to physical activity) in fighting diseases has attracted the attention of scientists. Muscle-secreting cytokines (myokines) provide communication between muscle and other tissues and organs such as the brain, adipose tissue, bone, liver, intestines, pancreas, etc., and physical activity is a way to stimulate the secretion of these myokines from the muscle. Myokines are involved in critical processes of the body such as cognition, lipid, and glucose metabolism, browning of white fat, bone formation, endothelial cell function, hypertrophy, skin structure, and tumor growth (Severinsen & Pedersen, 2020); therefore, they can be studied as a mechanism for the effect of physical activity on various diseases.
Irisin is a myokine. It is secreted from skeletal muscle in response to physical activity. Physical activity increases the transcriptional activator of PGC1-α and induces the expression of the FNDC5 gene, and subsequently, irisin is released into the blood. Irisin facilitates glucose uptake by skeletal muscle, improves glucose and liver fat metabolism, has a positive effect on hyperlipidemia and hyperglycemia due to obesity and metabolic syndrome, and acts as an insulin-sensitizing hormone (Severinsen & Pedersen, 2020).
The role of irisin in cancer treatment is unclear, and further studies are needed. The results of a review study show that regular physical activity increases irisin, but the use of irisin in cancer therapeutics requires further researches (Maalouf & El Khoury, 2019). More studies should be performed to determine the mode of administration of irisin for each cancer type and investigate the amount of use. Moreover, studies on the impact of physical activity on irisin in cancer patients are required.

Abstract Dear Editor-in-Chief
New approaches to endocrinology have confirmed that every cell secretes hormones. These secreted substances are called cytokines. However, they are also named based on their origin. For example, the secretions of adipose and muscle tissue cells are called adipokines and myokines, respectively (Chait & den Hartigh, 2020).
The endocrine function of adipose tissue has been determined in some studies. It secretes substances called adipokines. Released adipokines (such as leptin, adiponectin, visfatin, resistin, omentin) act as autocrine/paracrine and endocrine (Landecho et al., 2019).
 Adipokines play an essential role in regulating glucose and lipid metabolism, energy homeostasis, nutritional behavior, insulin sensitivity, inflammation, the immune system, adipose tissue production, vascular function, coagulation, and other bodily functions (Chait & den Hartigh, 2020). Leptin, for example, regulates body fat mass and obesity (when it increases in the bloodstream) through appetite and satiety receptors (in the hypothalamus). Unlike leptin, adiponectin reduces body fat mass and regulates glucose and lipid homeostasis. The resistin can be thought of as a link between obesity, diabetes, and insulin resistance. The visfatin plays an essential role in inflammatory and infectious diseases through pro-inflammatory and anti-apoptotic ability. Omentin significantly reduces the acute phase protein in endothelial cells and can be considered an anti-inflammatory adipokine (Landecho et al., 2019). In general, adipokines act as a mediator in regulating the function of tissues and other organs such as the liver, skeletal muscle, pancreas, and cardiovascular system. Adipose tissue dysfunction plays a significant role in insulin resistance, type 2 diabetes, cardiovascular disease, and metabolic disease (Balistreri, Caruso, & Candore, 2010).
Exercise promotes adaptation to skeletal muscle, adipose tissue and consequently prevents metabolic disorders. Physical activity causes these beneficial effects by altering myokines (skeletal muscle secretions) and adipokines. Adipokines and myokines play a role in facilitating tissue-to-tissue communication (tissue crosstalk) and work together to improve health. Studies show that skeletal muscle releasing myokines during a contraction may influence adipokines (Leal, Lopes, & Batista, 2018). Moreover, Shirvani et al. showed a significant positive correlation between plasma levels of irisin with the nesfatin-1 and a significant negative correlation with resistin. Therefore, physical activity could create metabolic crosstalk between skeletal muscle and adipose tissue (Shirvani & Rahmati-Ahmadabad, 2019). Doing crosstalk research by researchers is crucial to better understand the health-related molecular mechanisms (created by exercise).