Circadian rhythms govern our daily physiological processes. However, disruption of circadian rhythms, as can occur with
ad libitum
Western diets, disrupt these processes leading to cardiometabolic diseases. Our lab and others have shown that Th17 cells, which produce interleukin 17A (IL-17A), are implicated in the development of cardiovascular and renal end-organ damage associated with high fat and/or high salt diets. Th17 cell differentiation and trafficking is regulated by the circadian clock and influenced by light-dark cycles. However, whether feeding-fasting rhythms influence Th17 cell responses is poorly understood. We tested the hypothesis that limiting food intake to the 12-hr active period (time-restricted feeding, TRF) mitigates high fat and high salt (HF/HS) diet induced T cell IL-17A production and target organ damage. Beginning at 8 weeks of age, male C57Bl/6J mice were placed on either a normal chow/normal salt (NC/NS) or a HF/HS diet for 20 weeks, with TRF intervention occurring during the last two weeks in the HF/HS + TRF group. Body weight was similarly significantly increased in the HF/HS and HF/HS + TRF groups in comparison to the NC/NS group. Th17 cells were significantly increased (2.6-fold increase, p = 0.02) in the Peyer’s patches (lymphoid aggregates found in the small intestines) of mice on HF/HS diet in comparison to those on NC/NS. Importantly, TRF abolished this increase. Renal CD4
+
T cell IL-17A production, as measured by flow cytometry, was increased by HF/HS diet compared to NC/NS (3-fold increase, p = 0.02). Similarly, TRF abolished this increase. This study highlights how Western diets exacerbate intestinal and renal IL-17A production and the potential beneficial impact of a behavioral intervention, TRF, to mitigate the Th17 mediated inflammation associated with diet-induced obesity.
A protective function for interleukin 17A in T cell–mediated intestinal inflammation