Effect of Acute and Prolonged Inflammation on the Gene Expression of Proinflammatory Cytokines and Their Receptors in the Anterior Pituitary Gland of Ewes

Abstract

An acute and prolonged inflammation inhibits the reproduction process by the disruption of the neurohormonal activity of the hypothalamic-pituitary-gonadal axis. It is thought that these changes may be caused by proinflammatory cytokines, i.e., interleukin (IL) -1β, IL-6 and tumor necrosis factor (TNF) α. The aim of this study was to determine the effect of an acute and prolonged inflammation on the expression of genes encoding cytokine and their receptors, gonadotropin releasing hormone receptor (GnRHR), beta subunits of luteinizing hormone (LHβ) and follicle-stimulating (FSHβ) in the anterior pituitary (AP). Moreover, the circulating concentration of LH and FSH was also assayed. Two experiments were carried out on adult ewes which were divided into two control groups and treated with lipopolysaccharide (LPS; 400 ng / kg). Acute inflammation was caused by a single injection of LPS into the external jugular vein, while the chronic inflammation was induced by seven times LPS injection (one a day). In both experiments, animals were euthanized 3h after the last LPS / NaCl injection and the blood samples collected 15 min before euthanasia. An acute inflammation stimulates the expression of the IL-1β, IL-6 and TNFα genes and their receptors in the AP of sheep. Prolonged inflammation increased TNFα gene expression and both types of TNFα and IL-6 receptors. Both an acute and prolonged inflammation inhibited LHβ gene expression in the AP and reduced LH level in blood. A sevenfold LPS injection raises FSH concentration. The gene expression of GnRHR was reduced in the ovine AP only after a single injection of endotoxin. Our results suggest that there are important differences in the way how an acute and prolonged inflammation influence proinflammatory cytokines and their receptors gene expression in the AP of anestrous ewes, which could be reflected by differences in the AP secretory activity during these states.

Coal dust affects hypothalamic pituitary testicular axis and impairs glucose homeostasis in coal mine workers

“…On the other hand, TNF-α controls the intensity, e cacy, and duration of in ammatory reactions (Giovannini et al 2011). Therefore, the present data revealed the activation of acute phase reactants in response to in ammation caused by coal dust exposure in the study participants and also consolidate the earlier nding that acute and prolonged in ammation inhibits the reproduction process by activating proin ammatory cytokines, i.e., interleukin (IL) -1β, IL-6 and tumor necrosis factor (TNF) α and disrupting the neurohormonal activity of the hypothalamic-pituitary-gonadal axis (Wojtulewicz et al, 2020).…”

The Effect of Leptin on the Blood Hormonal Profile (Cortisol, Insulin, Thyroid Hormones) of the Ewe in Acute Inflammation in Two Different Photoperiodical Conditions

“…When a prior LPS injection was made, there was no difference in the leptin peak concentration, but the leptin concentration decreased faster when a prior LPS injection was carried out in comparison to animals in the physiological state, which may suggest that either leptin had a faster metabolism or it bounded faster to its receptor to exert the effect. Moreover, leptin can bind not only to its receptor but also non-specifically to the IL-6 receptor (IL-6R) [ 29 ], and it is well documented that IL6-R expression is highly increased after LPS injection as well, which we also observed in acute stress conditions in sheep aorta [ 18 ], perivascular adipose tissue [ 19 ], hypothalamus [ 30 ] and anterior pituitary [ 21 ], but not in the prolonged inflammation in the anterior pituitary [ 31 ].…”

Relationship between Neuroglial Apoptosis and Neuroinflammation in the Epileptic Focus of the Brain and in the Blood of Patients with Drug-Resistant Epilepsy

“…IL-2 deficiency can cause autoimmune inflammation with neuron damage [ 36 ]. The cytokines circulation (TNF-α, IL-1, IL-8) in the bloodstream usually indicates an acute phase of the body’s response to inflammation, which is regulated by proinflammatory (IFN-γ, IL-12) or anti-inflammatory (IL-10) cytokines [ 37 ]. We have found that the level of proinflammatory TNF-α, IL-7, and sCD40L increased in the blood plasma of DRE patients, and the anti-inflammatory IL-4 level has also increased compensatory.…”