Effect of a single bout of exercise on clock gene expression in human leukocyte

Abstract

Mammals have circadian clocks, which consist of the central clock in the suprachiasmatic nucleus and the peripheral clocks in the peripheral tissues. The effect of exercise on phase of peripheral clocks have been reported in rodents but not in humans. Continuous sampling is necessary to assess the phase of the circadian rhythm of peripheral clock gene expressions. It has been assumed that the expression of the genes in leukocyte may be “an accessible window to the multiorgan transcriptome.” The present study aimed to examine whether exercise affects the level and phase of clock gene expression in human leukocytes. Eleven young men participated in three trials, in which they performed a single bout of exercise at 60% V̇o2max for 1 h beginning either at 0700 (morning exercise) or 1600 (afternoon exercise) or no exercise (control). Blood samples were collected at 0600, 0900, 1200, 1500, 1800, 2100, and 2300 and at 0600 the next morning, to assess diurnal changes of clock gene expression in leukocytes. Brain and muscle ARNT-like protein 1 ( Bmal1) expression level increased after morning and afternoon exercise, and Cryptochrome 1 ( Cry1) expression level increased after morning exercise. Compared with control trial, acrophase of Bmal1 expression tended to be earlier in morning exercise trial and later in afternoon exercise trial. Acrophase of Cry1 expression was earlier in morning exercise trial but not affected by afternoon exercise. Circadian locomotor output cycles kaput ( Clock), Period 1–3 ( Per1–3), and Cry2 expression levels and those acrophases were not affected by exercise. The present results suggest a potential role of a single bout of exercise to modify peripheral clocks in humans. NEW & NOTEWORTHY The present study showed that a single bout of exercise affected peripheral clock gene expression in human leukocytes and the effect of exercise depended on when it was performed. Brain and muscle ARNT-like protein 1 ( Bmal1) expression was increased after exercises performed in the morning and afternoon. Cryptochrome 1 ( Cry1) expression was also increased after the morning exercise. The effect of exercise on acrophase of Bmal1 depended on the time of the exercise: advanced after morning exercise and delayed after afternoon exercise.

Metabolic flexibility during sleep

“…Core body temperatures were continuously recorded using an ingestible core body temperature sensor (CorTemp, HQ Inc, Palmetto, FL, USA), 23 × 10.25 mm, weighing 2.75 g. The signal from the sensor passed through the body to the recorder, which was worn by the subjects around the stomach area. The sensor was accurate to ± 0.01 °C and was calibrated with hot water before each use 22,23 . ment focused on the effect of exercise on clock gene expression 22 , in which energy metabolism, blood glucose, core body temperature, heart rate and its variability were simultaneously measured.…”

“…The sensor was accurate to ± 0.01 °C and was calibrated with hot water before each use 22,23 . ment focused on the effect of exercise on clock gene expression 22 , in which energy metabolism, blood glucose, core body temperature, heart rate and its variability were simultaneously measured. Prescribed diet was provided as breakfast (9:00), lunch (13:00), and dinner (18:00), and energy balance over the 24 h of indirect calorimetry was + 27 ± 34 kcal/24 h. RQ and non-protein RQ increased in response to each meal, reached its nadir, and then re-ascended after midnight (Fig.…”

“…RQ was highly correlated to heart rate (r = 0.850, P < 0.001) and moderately correlated to HF (r = − 0.648, P < 0.001), but correlation to LF/HF was not statistically significant (P = 0.063). 22 . Prescribed diet was provided as breakfast (9:00), lunch (13:00), and dinner (18:00).…”

Effect of a single bout of morning or afternoon exercise on glucose fluctuation in young healthy men

“…Leukocyte clock gene expression and core body temperature findings from this experiment were published in another paper (Tanaka et al, 2020).…”

“…Fat oxidation over 24 h is increased by exercise performed before breakfast, but not after breakfast and the subsequent period (Iwayama et al, 2017; Iwayama, Kawabuchi, et al, 2015; Iwayama, Kurihara, et al, 2015; Shimada et al, 2013). Peak timing of the expression of Bmal1 , a clock gene in the core circadian loop, tends to be advanced by exercise performed in the morning, and tends to be delayed by exercise performed in the afternoon (Tanaka et al, 2020). Skeletal muscle cross‐sectional area is increased by exercise performed in the evening compared with that in the morning (Küüsmaa et al, 2016).…”