The Regulation of Lipokines by Environmental Factors

Abstract

Adipose tissue is a highly metabolically-active tissue that senses and secretes hormonal and lipid mediators that facilitate adaptations to metabolic tissues. In recent years, the role of lipokines, which are lipid species predominantly secreted from adipose tissue that act as hormonal regulators in many metabolic tissues, has been an important area of research for obesity and diabetes. Previous studies have identified that these secreted lipids, including palmitoleate, 12,13-diHOME, and fatty acid–hydroxy–fatty acids (FAHFA) species, are important regulators of metabolism. Moreover, environmental factors that directly affect the secretion of lipokines such as diet, exercise, and exposure to cold temperatures constitute attractive therapeutic strategies, but the mechanisms that regulate lipokine stimulation have not been thoroughly reviewed. In this study, we will discuss the chemical characteristics of lipokines that position them as attractive targets for chronic disease treatment and prevention and the emerging roles of lipokines as regulators of inter-tissue communication. We will define the target tissues of lipokines, and explore the ability of lipokines to prevent or delay the onset and development of chronic diseases. Comprehensive understanding of the lipokine synthesis and lipokine-driven regulation of metabolic outcomes is instrumental for developing novel preventative and therapeutic strategies that harness adipose tissue-derived lipokines.

The Pathogenesis of End-Stage Renal Disease from the Standpoint of the Theory of General Pathological Processes of Inflammation

“…However, the processes of para-inflammation can acquire a pathological character and contribute to a stable change in homeostasis—allostasis [ 80 ]. Increased levels of circulating cytokines and other proinflammatory agents, such as adipose tissue lipokines, are a key pathophysiological link between health, chronic disorders of the internal organs, and aging [ 52 , 81 , 82 ]. The presence of a systemic proinflammatory status, for example, in morbid obesity, is a risk factor for exercise intolerance, development of microvascular dementia, coronary microvascular angina pectoris, heart failure, chronic obstructive pulmonary disease, and CKD [ 83 ].…”

Palmitoleate Protects against Zika Virus-Induced Placental Trophoblast Apoptosis

“…Palmitoleate is abundant in adipose tissue, blood cells, and it is a part of cell membrane structure [57]. Palmitoleate plays an important role in maintaining metabolic health and homeostasis by acting as a lipokine [58]. Palmitoleate decreases fat deposition in the liver and enhances insulin sensitivity [57].…”

Diabetes Mellitus and Its Metabolic Complications: The Role of Adipose Tissues

“…Adipose tissue has a significant role in the metabolic adaptations linked to disease development and prevention. Environmental factors like exercise and exposure to cold may also contribute to varying metabolic adaptation in white and brown adipose tissue [ 136 , 137 , 138 , 139 , 140 , 141 ]. Brown adipose tissue has greater metabolic activity than white adipose tissue; hence, the upregulation of brown adipose tissue accrues glucose tolerance and insulin sensitivity benefits [ 142 , 143 , 144 ].…”

“…Lipokines have emerged as a class of endocrine factors that are derived from adipose tissue. Some investigated lipokines, including palmitoleate, prostaglandins, lysophosphatidic acid (LPA), palmitoleate, 12,13-diHOME, fatty acid–hydroxy–fatty acids (FAHFAs), oxylipins, and N-acyl amino acids, are taking on increased significance due to their roles in carbohydrate metabolism, insulin resistance and lipid metabolism [ 136 ]. They are among the signal molecules from adipose tissue with involvement in the mediation of communication between adipose tissue and other metabolic tissues that may ultimately be an effective therapeutic target for metabolic disease.…”

“…Palmitoleate is a lipokine because it is released from adipose tissue and affects distant organs [ 150 ]. The synthesis and secretion of the lipokine, palmitoleate by the adipose tissue results in the downregulation of liver lipid synthesis and the upregulation of skeletal muscle insulin action in vitro, demonstrating the potential role of palmitoleate mediation of the inter-tissue metabolism [ 136 ]. Hence increase in dietary intake of palmitoleate or the de novo synthesis may improve metabolic homeostasis.…”