Exercise-induced modulation of myokine irisin in bone and cartilage tissue—Positive effects on osteoarthritis: A narrative review

Abstract

Osteoarthritis is a chronic degenerative musculoskeletal disease characterized by pathological changes in joint structures along with the incidence of which increases with age. Exercise is recommended for all clinical treatment guidelines of osteoarthritis, but the exact molecular mechanisms are still unknown. Irisin is a newly discovered myokine released mainly by skeletal muscle in recent years—a biologically active protein capable of being released into the bloodstream as an endocrine factor, the synthesis and secretion of which is specifically induced by exercise-induced muscle contraction. Although the discovery of irisin is relatively recent, its role in affecting bone density and cartilage homeostasis has been reported. Here, we review the production and structural characteristics of irisin and discuss the effects of the different types of exercise involved in the current study on irisin and the role of irisin in anti-aging. In addition, the role of irisin in the regulation of bone mineral density, bone metabolism, and its role in chondrocyte homeostasis and metabolism is reviewed. A series of studies on irisin have provided new insights into the mechanisms of exercise training in improving bone density, resisting cartilage degeneration, and maintaining the overall environmental homeostasis of the joint. These studies further contribute to the understanding of the role of exercise in the fight against osteoarthritis and will provide an important reference and aid in the development of the field of osteoarthritis prevention and treatment.

Rejuvenation of Senescent Cells, in vitro and in vivo, by Low-frequency Ultrasound without Senolysis

“…All four criteria were met with each type of senescent cells (Fig. 1A) in that cell growth was blocked (Figure 1B), cell size increased (Figure 1C and 1D) (27), cells secreted SASP (15) (Figure 1E) and β-galactosidase activity increased in over 98% of cells (Figure 1F and 1G). Thus, by all criteria, we had created senescent cells.…”

“…Physical exercise is one early intervention to slow aging that is widely accepted ( 24 - 26 ) and has even been considered as a senolytic ( 22 ). Although the effects of exercise could be purely physical, there is evidence that exercise affects the brain and other organs through increased secretion of the myokines such as irisin ( 27 ). We report here that, surprisingly, physical pressure waves of low frequency ultrasound (LFU) can restore senescent cell growth by rejuvenating them.…”

“…17 Although the effects of exercise could be purely physical, there is evidence that exercise affects the brain and other organs through increased secretion of myokines, such as irisin. 50 Ultrasound produces short duration pressure waves in cells that create mechanical stresses. These conditions are safe for normal tissues and do not adversely influence functions of normal cells.…”

The Role of Lubricin, Irisin and Exercise in the Prevention and Treatment of Osteoarthritis

“…The preventive mechanism of exercise in cartilage tissues to prevent and manage OA was better elucidated when irisin was discovered, and it was described as a myokine released by skeletal muscle in response to exercise stimulation, implicated in resistance to aging [ 47 , 56 , 57 ]. Therefore, some research investigated the possibility of modulating irisin through physical activity.…”

Вплив Секреторної Функції Скелетних М’язів У Реабілітації

“…Key words: irisin, skeletal muscles, myosins, myofibril fibers. [4]. Захисний вплив фізичної активності на хронічне захворювання можна пояснити протизапальною дією регулярної фізичної активності [5].…”