Fig 1.
Methionine synthase contains a redox-active methylcobalamin cofactor. Under oxidative stress, this cofactor becomes oxidized, limiting methionine synthase activity and can affect the levels of global DNA Methylation Under these conditions, homocysteine can be condensed with serine to form cystathionine and then with cysteine to support GSH synthesis. Another source of the cysteine is through the Excitatory Amino Acid Transport (EAAT3), which is the major source of cysteine especially in the neuronal cells. Cellular redox state is indicated by the GSH/GSSG ratio.
Fig 2.
Sleep behavior was objectively verified the week prior to sleep deprivation through actigraph monitoring. Top left: actigraphy-recorded time-in-bed confirmed that the participants generally adhered to the instruction to sleep 8 hours the week prior to sleep deprivation (mean = 8.03, SD = 1.12). Top Right: Total sleep actigraphy-recorded sleep time was 6 hours and 10 min (SD = 1.04). Bottom Left: The average sleep latency was 16 minutes (SD = 10.29). Bottom Right: the average sleep efficiency was 82.64% (SD = 4.71).
Fig 3.
Thiol metabolite levels in plasma.
Thiol / Thioether metabolite levels were analyzed via HPLC with electrochemical detection before (BL) and after sleep deprivation (SD) in participants (Mean +/- SEM). GSH / GSSG ratio indicates oxidative stress. HCY—homocysteine, Cys- cysteine were measured in uM. ATP measurement. ATP was measured using commercially available kit and expressed in umol/ L of plasma. Asterisk indicates a significant difference from baseline * = p < 0.05, ** = p < 0.01.
Fig 4.
Moring cortisol levels were significantly lower after sleep deprivation (mean = 0.35, SD = 0.22) relative to the morning of baseline testing (mean = 0.63, SD = 0.24), t(18) = 6.61, p < 0.01.
Fig 5.
Plasma samples were used to isolate cell free circulating DNA. The percentage of 5-methylcytosine and 5-hydroxymethylcytosine on isolated DNA was measured using an ELISA assay (Mean +/- SEM). Asterisk indicates a significant difference from baseline * = p < 0.05, ** = p < 0.01.