Immune stress up regulates <i>TLR4</i> and <i>Tollip</i> gene expression in the hypothalamus of ewes

How does bacterial endotoxin influence gonadoliberin/gonadotropins secretion and action?

“…The results of our studies on ewes, in which the expression of TLR4 transcript was determined in the hypothalamic structures associated with GnRH-ergic activity, such as preoptic area (POA), anterior hypothalamus (AHA), MBH and medial eminence (ME), and anterior pituitary as well (Herman et al, 2013a;Haziak et al, 2014), support hypothesis that LPS can acts directly at the hypothalamic and pituitary level. In addition, the expression of TLR4 gene in those structures was up-regulated by intravenous administration of endotoxin that indicates that under inflammatory condition these regions of the hypothalamus may be characterized by increased sensitivity on the action of LPS molecules (Herman et al, 2013a). An important role of the centrally acting LPS and the complexity of its receptors expressed in the hypothalamus in the regulation of the GnRH/LH secretion during an immune/ inflammatory challenge was suggested in our studies performed on anoestrous ewes (Haziak et al, 2014).…”

“…This study confirmed that inflammation influences the CNS, not only by proinflammatory cytokines, but in order to develop a full pathophysiological response the expression of TLR4 on cells of this system is required (Chakravarty and Herkenham, 2005). The results of our studies on ewes, in which the expression of TLR4 transcript was determined in the hypothalamic structures associated with GnRH-ergic activity, such as preoptic area (POA), anterior hypothalamus (AHA), MBH and medial eminence (ME), and anterior pituitary as well (Herman et al, 2013a;Haziak et al, 2014), support hypothesis that LPS can acts directly at the hypothalamic and pituitary level. In addition, the expression of TLR4 gene in those structures was up-regulated by intravenous administration of endotoxin that indicates that under inflammatory condition these regions of the hypothalamus may be characterized by increased sensitivity on the action of LPS molecules (Herman et al, 2013a).…”

Genome-wide identification and characterization of five MyD88 duplication genes in Yesso scallop (Patinopecten yessoensis) and expression changes in response to bacterial challenge

“…For instance, the expression of PyMyD88-1, PyMyD88-2a, PyMyD88-3 and PyMyD88-4 was markedly induced in the acute phase of infection with both bacteria and started to significantly decrease at 6 h post-challenge. The expression pattern of PyMyD88s is relevant to their activation by interleukin-1 (IL-1), TLRs, peptidoglycan recognition proteins (PGRPs) and tumor necrosis factor a (TNFa) through the corresponding signaling pathways, which have been widely reported in humans, ewes, Pacific oysters and Mediterranean mussels [13,19,45,58]. The consistent expression patterns between PyMyD88s and the TLR/IL-1R signaling pathway confirmed the important regulatory roles of PyMyD88 genes in the innate immune response of bivalves [18,24,31,54].…”

Plasma and cerebrospinal fluid interleukin-1β during lipopolysaccharide-induced systemic inflammation in ewes implanted or not with slow-release melatonin

“…After that stainless catheter was introduced into the third ventricle and control blood and CSF samples were collected. Then immune stress was induced by intravenously injection of LPS from Escherichia coli 055:B5 (Sigma, USA), at the dose of 400 ng/kg of body weight, dissolved in saline (0.9% w / v NaCl) at a concentration of 10 mg/L (10 μg/mL) as it was used previously in ewes [ 20 ]. The individual body mass of experimental ewes were at the range of 52 kg to 63 kg, therefore injection volume of LPS solution/saline was at the range of 2.1 to 2.5 mL.…”