The role of circadian rhythms and clock genes in cutaneous wound healing
Introduction
The governing of rhythmic changes involved in daily behaviour and/or physiology is controlled by light/dark cycles. The field of Chronobiology encompasses biological timings (hormone secretion, blood pressure, reproductive cycles, body temperature, sleep, locomotor activity). Circadian rhythms have been discovered to play a major role in the mental, physical and behavioural changes, which follow a 24 hour cycle, derived from the Latin phrase ‘’circa diem’’, translating to ‘about a day’. The skin, the largest organ of an individual, is primarily responsible for the protection from environmental dangers such as microbes, radiation, mechanical impacts, temperature variations, pressure changes and chemicals; acting as a barrier for protecting, regulating and sensation.
Wound healing
Comprised of three layers, the skin is essential in the response towards wound healing. The epidermis is the outer, superficial layer of the skin, within which there are 5 separate layers; the stratum corneum, stratum lucidum, granulosum, spinosum and the only proliferative stratum basale, which is constantly regenerating (figure 1). During movement, these layers …show more content…
Feedback loops, driven by basic helix-loop-helix (bHLH)-PAS (Period-Arnt-Single-minded) heterodimer, more specifically, the transcription factors BMAL1/CLOCK or BMAL1/NPAS2. These act as positive activators of Cryptochrome (Cry1 and Cry2) and Period (Per1, Per2 and Per3), which ultimately function as transcriptional repressor targets; found downstream of BMAL1/CLOCK, BMAL/NPAS2 or other circadian genes such as Clock (clk), Cycle (cyc), Timeless (tim), Frequency (frq), Doubletime (dbt) (Young and Kay 2001), which contain E-box cis-regulatory enhancer sequences. In mammals, Clock, Bmal1, Per1, Per2, Cry1, and Cry2 have been identified (Mohawk et al.
Introduction
The governing of rhythmic changes involved in daily behaviour and/or physiology is controlled by light/dark cycles. The field of Chronobiology encompasses biological timings (hormone secretion, blood pressure, reproductive cycles, body temperature, sleep, locomotor activity). Circadian rhythms have been discovered to play a major role in the mental, physical and behavioural changes, which follow a 24 hour cycle, derived from the Latin phrase ‘’circa diem’’, translating to ‘about a day’. The skin, the largest organ of an individual, is primarily responsible for the protection from environmental dangers such as microbes, radiation, mechanical impacts, temperature variations, pressure changes and chemicals; acting as a barrier for protecting, regulating and sensation.
Wound healing
Comprised of three layers, the skin is essential in the response towards wound healing. The epidermis is the outer, superficial layer of the skin, within which there are 5 separate layers; the stratum corneum, stratum lucidum, granulosum, spinosum and the only proliferative stratum basale, which is constantly regenerating (figure 1). During movement, these layers …show more content…
Feedback loops, driven by basic helix-loop-helix (bHLH)-PAS (Period-Arnt-Single-minded) heterodimer, more specifically, the transcription factors BMAL1/CLOCK or BMAL1/NPAS2. These act as positive activators of Cryptochrome (Cry1 and Cry2) and Period (Per1, Per2 and Per3), which ultimately function as transcriptional repressor targets; found downstream of BMAL1/CLOCK, BMAL/NPAS2 or other circadian genes such as Clock (clk), Cycle (cyc), Timeless (tim), Frequency (frq), Doubletime (dbt) (Young and Kay 2001), which contain E-box cis-regulatory enhancer sequences. In mammals, Clock, Bmal1, Per1, Per2, Cry1, and Cry2 have been identified (Mohawk et al.