A systematic review of the effects of cold exposure on pathological cardiac remodeling in mice.

Exposure to cold promotes cardiac remodeling, characterized by deleterious effects on structure and function, contributing to increased mortality from cardiovascular diseases. The mechanisms associated with these changes are poorly understood. This review gathers the literature data on the main alterations and mechanisms associated with the adverse cardiac structural and functional remodeling induced by cold exposure in mice. Original studies were identified by searching PubMed, Scopus, and Embase databases from January 1990 to June 2022. This systematic review was conducted in accordance with the criteria established by PRISMA and registered in PROSPERO (CRD42022350637). The risk of bias was evaluated by the SYRCLE. Eligible studies included original papers published in English that evaluated cardiac outcomes in mice submitted to short- or long-time cold exposure and had a control group at room temperature. Seventeen original articles were included in this review. Cold exposure induces pathological cardiac remodeling, characterized by detrimental structural and functional parameters, changes in metabolism and autophagy process, and increases in oxidative stress, inflammation, and apoptosis. In addition, Nppa, AT1A, Fbp3, BECN, ETA, and MT, appear to play fundamental roles in regulating cardiac remodeling. We suggest that strategies that seek to minimize the CVD risk and adverse effects of cold exposure should target these agents.

The Effect of Diet on the Cardiac Circadian Clock in Mice: A Systematic Review.

Circadian rhythms play important roles in regulating physiological and behavioral processes. These are adjusted by environmental cues, such as diet, which acts by synchronizing or attenuating the circadian rhythms of peripheral clocks, such as the liver, intestine, pancreas, white and brown adipose tissue, lungs, kidneys, as well as the heart. Some studies point to the influence of diet composition, feeding timing, and dietary restriction on metabolic homeostasis and circadian rhythms at various levels. Therefore, this systematic review aimed to discuss studies addressing the effect of diet on the heart clock in animal models and, additionally, the chronodisruption of the clock and its relation to the development of cardiovascular disorders in the last 15 years. A search was conducted in the PubMed, Scopus, and Embase databases. The PRISMA guide was used to construct the article. Nineteen studies met all inclusion and exclusion criteria. In summary, these studies have linked the circadian clock to cardiovascular health and suggested that maintaining a robust circadian system may reduce the risks of cardiometabolic and cardiovascular diseases. The effect of time-of-day-dependent eating on the modulation of circadian rhythms of the cardiac clock and energy homeostasis is notable, among its deleterious effects predominantly in the sleep (light) phase and/or at the end of the active phase.