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Published online 11 March 2009 | Nature 458, 142-144 (2009) | doi:10.1038/458142a
News Feature
Circadian rhythms: Of owls, larks and alarm clocks
Could out-of-sync body clocks be contributing to human disease? Melissa Lee Phillips reports.
Ten years ago, researchers reported on three families with an extreme 'lark' problem. Larks are people who naturally wake up early in the morning, and are the opposite of 'owls', who wake up and go to sleep late.
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Zhu L, Wang YQ, Liu TCY, Liu SH. 2009. Photobiomodulation on TNF-alpha induced expression suppression of circadian clock genes in cultured NIH3T3 fibroblasts. Lasers Surg Med. 41(21S) (to be published)? Background and Objective: Campbell et al. (1998) found that 3 h of bright light exposure to the area behind the knee caused phase shifts of the human circadian rhythms, but Wright et al. (2002) did not find the circadian phase resetting. It was studied by using cellular model in this paper. Study Design/Materials and Methods: The expression of the circadian clock genes in NIH3T3 fibroblasts was synchronized by 50% horse serum shock. Its suppression was induced with TNF-alpha at 10 ng/mL. Its photobiomodulation was then done with low intensity 810 nm laser irradiation (LIDL) at dose[intensity (mW/cm2)@irradiation time (mins)], dose 1, 5@5; dose 2, 5@10; dose 3, 10@5; dose 4, 10@10; dose 5, 10@20. The mRNA expression level of the circadian clock genes mPer1, mPer2, mPer3 and clock control genes mDbp was assessed by semi-quantification reverse transcriptase polymerase chain reaction (RT-PCR). Results: LIDL at dose 1 and dose 5 promoted and inhibited the TNF-alpha induced expression suppression (TAES) of mPer1, mPer2, mPer3 and mDbp (P<0.01). LIDL at dose 2 inhibited mPer1 TAES of (P<0.01). LIDL at dose 3 inhibited the TAES of mPer1 and mDbp (P<0.01). LIDL at dose 4 inhibited the TAES of mPer1, mPer3 and mDbp (P<0.01). Among doses 2-5, LIDL at dose 4 was the most effective in inhibiting TAES of mPer1, mPer3 and mDbp. Conclusions: TNF-alpha induced inhibition effect of the circadian clock genes? expression may be modulated with LIDL.
there is a DIFFERENCE between association and causality. the correlation between depression and sleep problems does NOT mean that sleep problems cause depression. just as likely to be the other way round
Are there meant to be references? In any case some of these claims may be partly due to vitamin D depletion in shift workers.
Dr. McClug from Univ Tx, Dallas, needs to get in touch with Dr. Russel Reiter from Univ Tx, San Antonia! The extensive amount of work that has been done regarding the need for supplementation with melatonin must be considered. Melatonin is an anti-aging supplement, a radio-protectant, a cancer fighter -- basically, one of the most powerful of antioxidants! The above references to clock gene, etc. is ironic because simply sleeping close to an electric clock, telephone equipment and/or any item that has a speaker (magnet) is known to interfere with sleep and/or sleep quality. Low melatonin levels are linked to autism-spectrum disorders, Leukemia, breast cancer, Alzheimers -- numerous health problems. Melatonin is used as a cancer treatment, in some cases, "alone," and there are many studies re melatonin as an adjunct to chemotherapy. Why would we need a "drug" -- Rametheon to reduce effects of insomnia by minicking action of melatonin, when we can simply take melatonin? MONEY may be the reason? This article even mentions attempts to come up with pharmacological solution may mess something else up! Instead of worrying about what one's clock gene is doing or not, simply "move your bedside clock!" Joanne C. Mueller www.guineapigsrus.org
Wireless technology is part of the problem. Don't talk on the mobile phone before bed, and turn off the wireless, this has been shown to disrupt the production of melatonin in the body. For improved sleep, turn it off!