Alterations in mitochondria and cellular senescence in aged sEH null female kidneys.

Age-related structural and functional deterioration of the kidneys is common among elderly individuals and contributes to increased mortality and morbidity. Mitochondrial dysfunction and cellular senescence are two hallmarks of aging that drive a progressional renal decline; however, the underlying molecular mechanisms and endogenous regulators behind these processes remain incompletely understood. The metabolism of polyunsaturated fatty acids by CYP450 enzymes produces numerous bioactive lipid mediators that can be further metabolized by soluble epoxide hydrolase (sEH) and microsomal epoxide hydrolase (mEH) into diol metabolites, often with reduced biological effects.

The role of CYP-sEH derived lipid mediators in regulating mitochondrial biology and cellular senescence: implications for the aging heart.

Cellular senescence is a condition characterized by stable, irreversible cell cycle arrest linked to the aging process. The accumulation of senescent cells in the cardiac muscle can contribute to various cardiovascular diseases (CVD). Telomere shortening, epigenetic modifications, DNA damage, mitochondrial dysfunction, and oxidative stress are known contributors to the onset of cellular senescence in the heart.

Cardioprotective response and senescence in aged sEH null female mice exposed to LPS.

Deterioration of physiological systems, like the cardiovascular system, occurs progressively with age impacting an individual's health and increasing susceptibility to injury and disease. Cellular senescence has an underlying role in age-related alterations and can be triggered by natural aging or prematurely by stressors such as the bacterial toxin lipopolysaccharide (LPS). The metabolism of polyunsaturated fatty acids by CYP450 enzymes produces numerous bioactive lipid mediators that can be further metabolized by soluble epoxide hydrolase (sEH) into diol metabolites, often with reduced biological effects.

Cardiomyocyte-specific disruption of soluble epoxide hydrolase limits inflammation to preserve cardiac function.

Endotoxemia elicits a multiorgan inflammatory response that results in cardiac dysfunction and often leads to death. Inflammation-induced metabolism of endogenous N-3 and N-6 polyunsaturated fatty acids generates numerous lipid mediators, such as epoxy fatty acids (EpFAs), which protect the heart. However, EpFAs are hydrolyzed by soluble epoxide hydrolase (sEH), which attenuates their cardioprotective actions.