scholarly journals Lipopolysaccharide induces a downregulation of adiponectin receptorsin-vitroandin-vivo

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1428 ◽  
Author(s):  
Alison Hall ◽  
Martin Leuwer ◽  
Paul Trayhurn ◽  
Ingeborg D. Welters

Background.Adipose tissue contributes to the inflammatory response through production of cytokines, recruitment of macrophages and modulation of the adiponectin system. Previous studies have identified a down-regulation of adiponectin in pathologies characterised by acute (sepsis and endotoxaemia) and chronic inflammation (obesity and type-II diabetes mellitus). In this study, we investigated the hypothesis that LPS would reduce adiponectin receptor expression in a murine model of endotoxaemia and in adipoocyte and myocyte cell cultures.Methods.25 mg/kg LPS was injected intra-peritoneally into C57BL/6J mice, equivalent volumes of normal saline were used in control animals. Mice were killed at 4 or 24 h post injection and tissues harvested. Murine adipocytes (3T3-L1) and myocytes (C2C12) were grown in standard culture, treated with LPS (0.1 µg/ml–10 µg/ml) and harvested at 4 and 24 h. RNA was extracted and qPCR was conducted according to standard protocols and relative expression was calculated.Results.After LPS treatment there was a significant reduction after 4 h in gene expression of adipo R1 in muscle and peri-renal fat and of adipo R2 in liver, peri-renal fat and abdominal wall subcutaneous fat. After 24 h, significant reductions were limited to muscle. Cell culture extracts showed varied changes with reduction in adiponectin and adipo R2 gene expression only in adipocytes.Conclusions.LPS reduced adiponectin receptor gene expression in several tissues including adipocytes. This reflects a down-regulation of this anti-inflammatory and insulin-sensitising pathway in response to LPS. The trend towards base line after 24 h in tissue depots may reflect counter-regulatory mechanisms. Adiponectin receptor regulation differs in the tissues investigated.

2015 ◽  
Vol 40 (3) ◽  
pp. 895-900 ◽  
Author(s):  
Francesca Felicia Caputi ◽  
Donatella Carretta ◽  
Francesca Lattanzio ◽  
Martina Palmisano ◽  
Sanzio Candeletti ◽  
...  

1995 ◽  
Vol 147 (2) ◽  
pp. 225-234 ◽  
Author(s):  
P A Bennett ◽  
A Levy ◽  
S Sophokleous ◽  
I C A F Robinson ◽  
S L Lightman

Abstract GH synthesis and release from the anterior pituitary is governed by the opposing actions of somatostatin (SS) and GH-releasing factor (GRF), derived from the periventricular and arcuate nucleus (ARC) of the hypothalamus respectively. GH is known to regulate its own release by hypothalamic autofeedback mechanisms, but the extent to which this is a direct effect rather than indirectly via the generation of IGFs is still a subject of debate. GH receptors are known to be present in the hypothalamus, but their physiological regulation is poorly understood. We therefore used in situ hybridization histochemistry to investigate the effects of GH status on hypothalamic GH receptor gene expression, using hypophysectomized normal and dw/dw dwarf rats as models of acquired and congenital GH deficiency. Hypophysectomy resulted in a timedependent reduction in GH receptor gene expression. ARC GH receptor transcripts in untreated dw/dw dwarf rats were half those found in normal animals of the same background strain (16·8±1·7 vs 9·3± 1·9 d.p.m./mg, P<0·05). Increasing circulating GH by peripheral infusion of 200 μg human GH (hGH)/day for 6 days increased ARC GH receptor expression in dw/dw rats to normal. In contrast, central infusions of hGH at 26·4 and 79·2 μg/day for 6 days in normal rats lowered ARC GH receptor gene expression. The sensitivity of GH receptor gene expression within the central nervous system to peripheral and central GH levels suggests that feedback regulation of GRF and/or SS may be mediated directly by these receptors, and that the sensitivity to GH feedback is also subject to autoregulation by GH altering its own receptor expression. Journal of Endocrinology (1995) 147, 225–234


1995 ◽  
Vol 5 (8) ◽  
pp. 1585-1590
Author(s):  
T Nakamura ◽  
I Ebihara ◽  
M Fukui ◽  
S Osada ◽  
Y Tomino ◽  
...  

This study assessed glomerular endothelin (ET)-1, ET-3, and ET-receptor A and B mRNA levels in puromycin aminonucleoside (PAN)-induced nephrosis. During the nephrotic stage, 8 days after PAN injection, ET-1 and ETB receptor mRNA were elevated by 2.8 +/- 0.8-fold (P < 0.01) and 2.4 +/- 0.9-fold (P < 0.01), respectively, as compared with controls. These mRNA levels decreased to control levels by Day 20, when the nephrosis was in remission. In contrast, glomerular ETA receptor mRNA levels did not change in PAN nephrosis or control rats during the experimental period. ET-3 mRNA was not detected in the glomeruli of PAN nephrosis or control rats. Additionally, plasma ET concentration and glomerular ET production were measured in PAN nephrosis and control rats by radio-immunoassay. Eight days after PAN injection, ET-1 levels in plasma and glomeruli were not significantly altered in rats with PAN-induced nephrosis (glomeruli, 104.68 +/- 16.46 pg/mg of protein versus 98.24 +/- 13.68 pg/mg of protein; plasma, 2.68 +/- 1.10 versus 2.52 +/- 0.98 pg/mL). The administration of methylprednisolone to PAN rats resulted in the rapid disappearance of proteinuria and partially attenuated the increased ET-1 and ETB receptor gene expression in the glomeruli. These data indicate that glomerular ET-1 and ETB receptor expression in PAN nephrosis in increased at the mRNA level and that methylprednisolone treatment results in an attenuated increase.


2021 ◽  
Vol 184 (5) ◽  
pp. 687-697
Author(s):  
Peter Breining ◽  
Steen B Pedersen ◽  
Mads Kjolby ◽  
Jacob B Hansen ◽  
Niels Jessen ◽  
...  

Objective Activation of brown adipose tissue is a promising strategy to treat and prevent obesity and obesity-related disorders. Activation of uncoupling protein 1 (UCP1) leads to uncoupled respiration and dissipation of stored energy as heat. Induction of UCP1-rich adipocytes in white adipose tissue, a process known as ‘browning’, serves as an alternative strategy to increase whole body uncoupling capacity. Here, we aim to assess the association between parathyroid hormone (PTH) receptor expression and UCP1 expression in human adipose tissues and to study PTH effects on human white and brown adipocyte lipolysis and UCP1 expression. Design A descriptive study of human neck adipose tissue biopsies substantiated by an interventional study on human neck-derived adipose tissue cell models. Methods Thermogenic markers and PTH receptor gene expression are assessed in human neck adipose tissue biopsies and are related to individual health records. PTH-initiated lipolysis and thermogenic gene induction are assessed in cultured human white and brown adipocyte cell models. PTH receptor involvement is investigated by PTH receptor silencing. Results PTH receptor gene expression correlates with UCP1 gene expression in the deep-neck adipose tissue in humans. In cell models, PTH receptor stimulation increases lipolysis and stimulates gene transcription of multiple thermogenic markers. Silencing of the PTH receptor attenuates the effects of PTH indicating a direct PTH effect via this receptor. Conclusion PTH 1 receptor stimulation by PTH may play a role in human adipose tissue metabolism by affecting lipolysis and thermogenic capacity.


2009 ◽  
Vol 8 (4) ◽  
pp. 272
Author(s):  
V. Sanchez-Freire ◽  
F.C. Burkhard ◽  
U.E. Studer ◽  
T.M. Kessler ◽  
A. Kuhn ◽  
...  

1990 ◽  
Vol 111 (5) ◽  
pp. 2149-2158 ◽  
Author(s):  
M W Majesky ◽  
M A Reidy ◽  
D F Bowen-Pope ◽  
C E Hart ◽  
J N Wilcox ◽  
...  

Smooth muscle cells (SMC) in rat carotid artery leave the quiescent state and proliferate after balloon catheter injury, but the signals for mitogenesis are not known. In this study, the possibility that cells within damaged arteries produce a growth factor that could act locally to stimulate SMC replication and repair was examined. We found that the genes for PDGF-A and -B (ligand) and PDGF receptor (alpha and beta subunits) were expressed in normal and injured carotid arteries and were independently regulated during repair of carotid injury. Two phases of PDGF ligand and receptor gene expression were observed: (a) In the early stage, a large decrease in PDGF beta-receptor mRNA levels preceded 10- to 12-fold increases in PDGF-A transcript abundance in the first 6 h after wounding. No change in PDGF alpha-receptor or PDGF-B gene expression was found at these times. (b) In the chronic phase, 2 wk after injury, neointimal tissue had lower levels of PDGF alpha-receptor mRNA (threefold) and higher levels of PDGF beta-receptor mRNA (three- to fivefold) than did restored media. Moreover, in situ hybridization studies identified a subpopulation of neointimal SMC localized at or near the luminal surface with a different pattern of gene expression than the underlying carotid SMC. Luminal SMC were strongly positive for PDGF-A and PDGF beta-receptor transcripts, while showing little or no hybridization for PDGF-B or PDGF alpha-receptor. Immunohistochemical studies showed strongly positive staining for PDGF-A in SMC along the luminal surface. These data show that changes in PDGF ligand and receptor expression occur at specific times and locations in injured carotid artery and suggest that these changes may play a role in regulating arterial wound repair.


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