Journal of Exercise & Organ Cross Talk

Abstract Dear Editor-in-Chief
Lifestyle-related diseases are usually caused by mistakes in daily life, such as smoking, unhealthy diet, and inactivity. Some of these diseases are including heart diseases, stroke, diabetes, obesity, metabolic syndrome, lung diseases and some types of cancer. These diseases are usually more prevalent in industrialized countries where sedentary lifestyles have spread. At the international level, these diseases are known as non-communicable and chronic diseases or degenerative diseases. Chronic diseases can lead to loss of independence, years of disability, or death, and impose a significant economic burden.
Regular physical activity helps improve your overall health, fitness and quality of life. Also, regular exercise helps reduce the risk of chronic diseases such as type 2 diabetes, heart disease, many types of cancer, depression, anxiety and dementia. Aerobic exercise can help improve your heart health and endurance. Also, these types of exercise help to lose weight. High-intensity interval training is generally safe and effective for most people. In high-intensity interval training, physical activity is performed alternately with high intensity and with low intensity, and these intensity changes have various effects on the health of the body. Strength training can improve muscle strength and endurance, make daily activities easier, reduce disease-related muscle weakness, and provide joint stability. In all these types of exercises, the skeletal muscle tissue has the most activity, and most of the positive effects of exercise are attributed to this tissue. Recently, it has been stated that muscle tissue as a secretome can secrete substances from itself and affect distant tissues. These substances secreted from muscle tissue are known as myokines.
During exercise muscles can produce and release cytokines, signaling peptides or myokines. These molecules can exert paracrine and endocrine actions. Not all of them are produced exclusively by skeletal muscle, as they can also be released by other cells such as adipose tissue (adipomyokines). Nevertheless, skeletal muscle is probably the major source of most myokines, as it constitutes more than 30% of human body mass (Piccirillo, 2019). Myokine irisin produced from muscle tissue can control many damages caused by fatty tissue and reduce the inflammatory damage of this tissue in metabolic diseases such as diabetes, fatty liver or even cardiovascular diseases. β-aminoisobutyric acid (BAIBA) is a myokine involved in browning of fat and it can reduce insulin resistance (Gonzalez-Gil & Elizondo-Montemayor, 2020). Myostatin also controls insulin resistance and prevents fat accumulation in the liver (Mikolasevic et al., 2020). Follistatin is also effective in regulating the growth of muscle tissue and reducing fat tissue (Song et al., 2019). FGF21 also promotes insulin sensitivity. Apelin and METRNL also have anti-inflammatory properties (Gholamrezayi et al., 2020). All these myokines can be effective in reducing lifestyle-related diseases with their role. Therefore, exercise should be included in your daily life.

Abstract Dear Editor-in-Chief
During pregnancy, regular physical activity contributes to the health of the mother and fetus, which is due to the effect of exercise on the mother's physiological regulation, growth, and optimal function of the fetal placenta. But the mechanism of this effect is unknown. Recently, studies have shown that exercise can connect multiple tissues through the tissue secretomes. Muscle tissue secreting myokine can affect distant tissues such as the liver, adipose tissue, brain, skin, and even the placenta. However, other tissues can also affect muscle tissue. The human placenta as multifunctional organ releases large amounts of hormones, cytokines, placental proteins, non-coding RNAs, as well as extracellular vesicles into the mother's bloodstream (Adam et al., 2017). Exosomes are nanometer-sized extracellular vesicles produced by the endosomal pathway and packed with tissue-specific molecules. Because these nanoparticles can selectively target specific cells and transmit their contents to receptor cells, they form an integral pathway from cell-to-cell communication (Valadi et al., 2007). For example, exosomes secreted from the placenta reduce insulin sensitivity in muscle tissue and improve glucose metabolism in skeletal muscles during pregnancy (Nair et al., 2018). Since exercise itself is effective in improving insulin sensitivity, especially during pregnancy, it seems that one of the mechanisms involved could be the regulation of placental exosome secretion and its effect on muscle tissue, which has not been studied so far.
Evidence suggests that skeletal muscle during exercise by secreting endocrine factors such as myokines affect liver, adipose tissue, and placenta during pregnancy. Moreover, myokines can improve glucose and fat metabolism in mother’s body (Laurens, Bergouignan, & Moro, 2020).  So far, more than 600 myokines have been identified, the most important of which is irisin. This factor is secreted from muscle tissue and can affect the metabolism of other tissues, including white adipose tissue. It has also been reported that the level of this myokine can increase during pregnancy. The vital involvement of irisin in various key metabolic pathways increases attention to considering the effects of this myokine during pregnancy. Maternal circulating levels of irisin were measured in the range of 5-50 nM (Seven et al., 2019). In pregnant women during normal pregnancy, this factor is significantly higher than irisin levels in non-pregnant women. The potential role of circulation irisin on placenta is currently unknown. Since muscle contraction and exercise cause a significant increase in irisin expression (Sousa, Improta-Caria, & Souza, 2021), it seems that exercise during pregnancy with an increase in irisin also affects the placenta, which needs further investigation.
Recently, it was observed that maternal exercise stimulates the expression of myokine and adipokine apelin in addition to adipose tissue and skeletal muscle in human placenta. The new "exerkine" apelin appears to play a regulatory role in response to exercise during pregnancy in metabolic health (such as energy metabolism, fluid homeostasis, blood pressure, etc.) and fetal muscle development (Son et al., 2020). Furthermore, Bhattacharjee et al. in a current human study showed that regularly physically active women during pregnancy have a significantly increased placental expression of the myokine vascular endothelial growth factor (VEGF) and its VEGF receptor-1 compared to inactive women (Bhattacharjee et al., 2021). Further research is needed to assess the cross-talk between apelin and VEGF and the placenta in more details.
Fibroblast growth factor 21 (FGF21) is also a key regulator of endocrine and paracrine glucose and lipid metabolism, which is secreted from muscle tissue and can affect other tissues, including the placenta. FGF21 appears to affect the placenta through FGFRs and co-receptor β-klotho (Sun, Sherrier, & Li, 2021). Therefore, according to the evidence, it seems that the study of cross-talk subtypes of the endocrine family of FGFs (FGF19, FGF21, FGF23) and especially FGF21 with klotho protein along with the intervention of physical activity is a new topic to identify the mechanism. The effects of exercise on the human placenta need to be examined more closely (Bhattacharjee, Mohammad, & Adamo, 2021).
 

Abstract PH stress can be caused by menopause, poor nutrition, high protein intake, old age, prolonged strenuous and anaerobic exercise, anemia, diabetes, AIDS, and respiratory diseases. High calcium enters the bloodstream from the bones during the proton buffering due to metabolic acidosis, which the renal system excretes a significant amount of this calcium to eliminate the acidosis condition and regulate body pH. At the bone surface, this increase in hydrogen ions due to metabolic acidosis can destroy osteoblastic and strengthen osteoclast activity, which negative bone turnover and increases the amount of excreted calcium, thus accelerating the progress of osteoporosis. Due to the widespread prevalence of osteoporosis in postmenopausal women and the provision of various therapies such as medication, estrogen therapy, and proper diet, in recent studies, special attention has been paid to the role of endurance and resistance exercise to decrease osteoporosis or prevent the development of this disease. Also exercise training increases irisin secretion from muscle tissue, which this myokine has beneficial effects on other tissues especially on bone. Irisin increases osteocytic survival and production of sclerostin in bone tissue, which is associated with bone remodeling. However, exercise training in some intensity through metabolic mechanisms can increase pH stress and acidosis and may contribute to the development of osteoporosis in postmenopausal women.  As a result, the hypothesis of different intensities of exercise and their induced acidosis stimuli in postmenopausal women should be considered.