Monochromatic Light Pollution Exacerbates High-Fat Diet-Induced Adipocytic Hypertrophy in Mice.
Qingyun GuanYixuan LiZixu WangJing CaoYulan DongFazheng RenYaoxing ChenPublished in: Cells (2022)
Light pollution worldwide promotes the progression of obesity, which is widely considered a consequence of circadian rhythm disruptions. However, the role of environmental light wavelength in mammalian obesity is not fully understood. Herein, mice fed a normal chow diet (NCD) or a high-fat diet (HFD) were exposed to daytime white (WL), blue (BL), green (GL), and red light (RL) for 8 weeks. Compared with WL and RL, BL significantly increased weight gain and white adipose tissue (WAT) weight, and it disrupted glucose homeostasis in mice fed with HFD but not NCD. The analysis of WAT found that BL significantly aggravated HFD-induced WAT hypertrophy, with a decrease in IL-10 and an increase in NLRP3, p-P65, p-IκB, TLR4, Cd36, Chrebp, Srebp-1c, Fasn, and Cpt1β relative to WL or RL. More interestingly, BL upregulated the expression of circadian clocks in the WAT, including Clock, Bmal1, Per1, Cry1, Cry2, Rorα, Rev-erbα, and Rev-erbβ compared with WL or RL. However, most of the changes had no statistical difference between BL and GL. Mechanistically, BL significantly increased plasma corticosterone (CORT) levels and glucocorticoid receptors in the WAT, which may account for the changes in circadian clocks. Further, in vitro study confirmed that CORT treatment did promote the expression of circadian clocks in 3T3-L1 cells, accompanied by an increase in Chrebp, Cd36, Hsp90, P23, NLRP3, and p-P65. Thus, daily BL, rather than RL exposure-induced CORT elevation, may drive changes in the WAT circadian clocks, ultimately exacerbating lipid dysmetabolism and adipocytic hypertrophy in the HFD-fed mice.
Keyphrases
- high fat diet induced
- high fat diet
- insulin resistance
- adipose tissue
- weight gain
- metabolic syndrome
- skeletal muscle
- type diabetes
- weight loss
- poor prognosis
- body mass index
- heavy metals
- diabetic rats
- induced apoptosis
- high glucose
- obstructive sleep apnea
- oxidative stress
- particulate matter
- inflammatory response
- magnetic resonance imaging
- depressive symptoms
- magnetic resonance
- glycemic control
- long non coding rna
- binding protein
- heat shock protein
- cell death
- preterm birth
- body weight
- smoking cessation