Non-traditional cytokines: How catecholamines and adipokines influence macrophages in immunity, metabolism and the central nervous system

Abstract

Catecholamines and adipokines function as hormones; catecholamines as neurotransmitters in the sympathetic nervous system, and adipokines as mediators of metabolic processes. It has become increasingly clear, however, that both also function as immunomodulators of innate and adaptive immune cells, including macrophages. Macrophages can respond to, as well as produce their own catecholamines. Dopamine, noradrenaline, and adrenaline are the most abundant catecholamines in the body, and can induce both pro-inflammatory and anti-inflammatory immune responses in macrophages, as well as non-immune processes such as thermogenesis. Though they are responsive to adipokines, particularly lipoproteins, leptin, and adiponectin, macrophages generally do synthesize their own adipokines, with the exception being resistin-like molecules. Adipokines contribute to adverse metabolic and immune response by stimulating lipid accumulation, foam cell formation and pro-inflammatory cytokine production in macrophages. Adipokines can also promote balance or resolution during metabolic and immune processes by promoting reverse lipid transport and expression of Th2 cytokines. This review will explore the mechanisms by which catecholamines and adipokines influence macrophage function in neural pathways, immunity and metabolism.

Comparison of RELMα and RELMβ Single- and Double-Gene-Deficient Mice Reveals that RELMα Expression Dictates Inflammation and Worm Expulsion in Hookworm Infection

“…Host protection against STHs is dependent on the balance between effector immune responses that promote worm expulsion and immunoregulatory pathways that control excessive infection-induced inflammation (2). Resistin-like molecules (RELMs) are secreted proteins with putative effector and immunoregulatory functions against helminth infections (3,4). In humans, significant increases in resistin expression occur in both filarial nematode and gastrointestinal nematode infections (5,6).…”

Selective enrichment and determination of monoamine neurotransmitters by CU(II) immobilized magnetic solid phase extraction coupled with high-performance liquid chromatography-fluorescence detection

“…For instance, NE and E act as biomarkers in the study of diabetes, heart disease and anxiety. The deficiency of DA neurotransmission has been proved to be associated with Parkinson diseases and Chizophrenia [5,6]. For these reasons, the measurement of MNTs in biological samples is of great importance.…”

The Neuroimmune Axis in the Kidney

“…This involves direct effects on antigen-presenting immune cells or indirect effects via regulation of blood or lymphatic flow, regulation of distribution and production of lymphocytes, or modulation of proinflammatory peptide release. 10 Inflammatory cell recruitment and redistribution are also regulated by the sympathetic nervous system.…”

“…Major sympathetic neurotransmitters include norepinephrine, ATP, neuropeptide Y, and nitric oxide. 10 Although all these neorotransmitters directly influence immune cells, the best characterized is norepinephrine. This seems to hold true in Ang II-induced hypertension, where it was shown that dendritic cells express adrenergic receptors and that β2 receptor expression is increased.…”