Background: Redox signaling plays an important role in the lives of cells. This signaling
not only becomes apparent in pathologies but is also thought to be involved in maintaining
physiological homeostasis. Reactive Oxygen Species (ROS) can activate protein kinases: CaMKII,
PKG, PKA, ERK, PI3K, Akt, PKC, PDK, JNK, p38. It is unclear whether it is a direct interaction
of ROS with these kinases or whether their activation is a consequence of inhibition of phosphatases.
ROS have a biphasic effect on the transport of Ca2+ in the cell: on one hand, they activate the
sarcoplasmic reticulum Ca2+-ATPase, which can reduce the level of Ca2+ in the cell, and on the
other hand, they can inactivate Ca2+-ATPase of the plasma membrane and open the cation channels
TRPM2, which promote Ca2+-loading and subsequent apoptosis. ROS inhibit the enzyme PHD2,
which leads to the stabilization of HIF-α and the formation of the active transcription factor HIF.
Conclusion: Activation of STAT3 and STAT5, induced by cytokines or growth factors, may include
activation of NADPH oxidase and enhancement of ROS production. Normal physiological
production of ROS under the action of cytokines activates the JAK/STAT while excessive ROS
production leads to their inhibition. ROS cause the activation of the transcription factor NF-κB.
Physiological levels of ROS control cell proliferation and angiogenesis. ROS signaling is also involved
in beneficial adaptations to survive ischemia and hypoxia, while further increases in ROS
can trigger programmed cell death by the mechanism of apoptosis or autophagy. ROS formation in
the myocardium can be reduced by moderate exercise.