Circadian rhythm and disease: Relationship, new insights, and future perspectives

Abstract

The circadian system is responsible for internal functions and regulation of the organism according to environmental cues (zeitgebers). Circadian rhythm dysregulation or chronodisruption has been associated with several diseases, from mental to autoimmune diseases, and with life quality change. Following this, some therapies have been developed to correct circadian misalignments, such as light therapy and chronobiotics. In this manuscript, we describe the circadian‐related diseases so far investigated, and studies reporting relevant data on this topic, evidencing this relationship, are included. Despite the actual limitations in published work, there is clear evidence of the correlation between circadian rhythm dysregulation and disease origin/development, and, in this way, clock‐related therapies emerge as great progress in the clinical field. Future improvements in such interventions can lead to the development of successful chronotherapy strategies, deeply contributing to enhanced therapeutic outcomes.

Chrononutrition—When We Eat Is of the Essence in Tackling Obesity

“…Misalignment in the active/rest and feast/famine phases can be due to endogenous factors, e.g., genetic variants in the core clock machinery or due to external lifestyle factors such as extended exposure to artificial light, increased shift work, sedentarism, untimely and frequent snacking and jetlag, and leads to chronobiological vulnerabilities to various diseases ( Table 2 ) [ 46 , 79 , 80 , 81 , 82 ]. An umbrella term used for circadian disruptions is ‘chronodisruption’.…”

Circadian Clock Desynchronization and Insulin Resistance

“…The circadian rhythm consists in an endogenous variation of biological processes that occur within 24 h in living organisms such as animals, plants, fungi, and bacteria [6][7][8]. These endogenous rhythms reflect the functions of an intrinsic circadian clock which mediates physiological and behavioral processes with the aim of coordinating the internal environment with the external one.…”

“…These endogenous rhythms reflect the functions of an intrinsic circadian clock which mediates physiological and behavioral processes with the aim of coordinating the internal environment with the external one. The term biological clock was coined to identify the daily changes caused by continuous environmental variations to improve the survival of all existing organisms [7][8][9]. The biological clock controls the activation of intracellular signaling pathways; cell proliferation; DNA damage repair and response; angiogenesis; metabolic and redox homeostasis; and inflammatory and immune response of several tissues and organs [7][8][9].…”

“…The term biological clock was coined to identify the daily changes caused by continuous environmental variations to improve the survival of all existing organisms [7][8][9]. The biological clock controls the activation of intracellular signaling pathways; cell proliferation; DNA damage repair and response; angiogenesis; metabolic and redox homeostasis; and inflammatory and immune response of several tissues and organs [7][8][9]. The circadian timing system is characterized by a central clock in the suprachiasmatic nucleus (SCN) and peripheral clocks in peripheral tissues, including muscle, fat, and liver [7][8][9].…”

“…The biological clock controls the activation of intracellular signaling pathways; cell proliferation; DNA damage repair and response; angiogenesis; metabolic and redox homeostasis; and inflammatory and immune response of several tissues and organs [7][8][9]. The circadian timing system is characterized by a central clock in the suprachiasmatic nucleus (SCN) and peripheral clocks in peripheral tissues, including muscle, fat, and liver [7][8][9]. The SCN receives the light signal through the retina and the retinohypothalamic tract, and this is the most important activating signal or "Zeitgeber" (ZT) for the SCN.…”