IGF-I mediated inhibition of leptin receptor expression in porcine hepatocytes

2010 ◽  
Vol 155 (1) ◽  
pp. 43-48 ◽  
Author(s):  
T.G. Ramsay ◽  
M.P. Richards ◽  
C.J. Li ◽  
T.J. Caperna
Keyword(s):  
Leptin Receptor ◽  
Receptor Expression ◽  
Igf I ◽  
Porcine Hepatocytes

Hormonal regulation of leptin receptor expression in primary cultures of porcine hepatocytes

2005 ◽  
Vol 29 (4) ◽  
pp. 582-592 ◽  
Author(s):  
T.J. Caperna ◽  
A.E. Shannon ◽  
S.M. Poch ◽  
W.M. Garrett ◽  
M.P. Richards
Keyword(s):  
Hormonal Regulation ◽  
Leptin Receptor ◽  
Primary Cultures ◽  
Receptor Expression ◽  
Porcine Hepatocytes

Gh and igf-i increase leptin receptor expression in prepubertal pig ovaries: The role of leptin in steroid secretion and cell apoptosis

2006 ◽  
Vol 54 (3) ◽  
pp. 413-426 ◽  
Author(s):  
Ewa L. Gregoraszczuk ◽  
Agnieszka Rak ◽  
Anna Wójtowicz ◽  
Anna Ptak ◽  
Tatiana Wojciechowicz ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Caspase 3 ◽  
Leptin Receptor ◽  
Ovarian Function ◽  
Receptor Expression ◽  
Igf I ◽  
Important Regulator ◽  
Polymerase Chain ◽  
Different Doses

Leptin (L) is recognised as an important regulator of puberty and a factor which controls reproduction. Whole pig ovarian follicles were incubated with different doses of leptin (2, 20 and 200 ng/ml) added alone or in combination with 100 ng/ml of GH or 50 ng/ml of IGF-I. The expression of the functional long form leptin receptor (Ob-Rb) mRNA was examined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) in follicular cells cultured with GH or IGF-I. Both GH and IGF-I increased leptin receptor expression in prepubertal pig ovaries. In separate experiments, the action of leptin on ovarian follicular steroidogenesis and cell apoptosis was examined. After 24 h of incubation with leptin alone or in combination with GH or IGF-I, oestradiol (E2) levels were determined in the culture medium while follicular tissue was used for the estimation of caspase-3 activity. Leptin increased E2 secretion and significantly diminished caspase-3 activity at all doses used. Both GH and IGF-I stimulated oestradiol secretion and decreased caspase-3 activity. No differences were demonstrable in oestradiol secretion and caspase-3 activity between cells treated with GH plus leptin and GH alone or cells treated with IGF-I plus leptin as compared to cultures treated with GH or IGF-I alone. However, GH diminished leptin-stimulated oestradiol secretion while IGF-I was without effect on it. Both GH and IGF-I reversed the anti-apoptotic action of leptin. In conclusion, we infer that (1) leptin directly affects ovarian function in prepubertal animals by its action on oestradiol secretion and cell apoptosis, (2) GH and IGF-I modulate the action of leptin, and (3) at least in part, the direct effect of GH/IGF-I on leptin production is due to an action on leptin receptor expression.

1870-P: Glucagon-Receptor Signaling Reverses Hepatic Steatosis Independent of Leptin Receptor Expression

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1870-P
Author(s):  
SHELLY NASON ◽  
TEAYOUN KIM ◽  
JESSICA P. ANTIPENKO ◽  
BRIAN FINAN ◽  
RICHARD DIMARCHI ◽  
...  
Keyword(s):  
Hepatic Steatosis ◽  
Leptin Receptor ◽  
Receptor Expression ◽  
Receptor Signaling ◽  
Glucagon Receptor

scholarly journals The Neuronal Actions of Leptin and the Implications for Treating Alzheimer’s Disease

2021 ◽  
Vol 14 (1) ◽  
pp. 52
Author(s):  
Kirsty Hamilton ◽  
Jenni Harvey
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Energy Homeostasis ◽  
Leptin Receptor ◽  
Hippocampal Formation ◽  
Synaptic Function ◽  
Receptor Expression ◽  
Neuroprotective Actions ◽  
Novel Target ◽  
Leptin System

It is widely accepted that the endocrine hormone leptin controls food intake and energy homeostasis via activation of leptin receptors expressed on hypothalamic arcuate neurons. The hippocampal formation also displays raised levels of leptin receptor expression and accumulating evidence indicates that leptin has a significant impact on hippocampal synaptic function. Thus, cellular and behavioural studies support a cognitive enhancing role for leptin as excitatory synaptic transmission, synaptic plasticity and glutamate receptor trafficking at hippocampal Schaffer collateral (SC)-CA1 synapses are regulated by leptin, and treatment with leptin enhances performance in hippocampus-dependent memory tasks. Recent studies indicate that hippocampal temporoammonic (TA)-CA1 synapses are also a key target for leptin. The ability of leptin to regulate TA-CA1 synapses has important functional consequences as TA-CA1 synapses are implicated in spatial and episodic memory processes. Moreover, degeneration is initiated in the TA pathway at very early stages of Alzheimer’s disease, and recent clinical evidence has revealed links between plasma leptin levels and the incidence of Alzheimer’s disease (AD). Additionally, accumulating evidence indicates that leptin has neuroprotective actions in various AD models, whereas dysfunctions in the leptin system accelerate AD pathogenesis. Here, we review the data implicating the leptin system as a potential novel target for AD, and the evidence that boosting the hippocampal actions of leptin may be beneficial.

scholarly journals Saturated fat-rich diet increases fetal lipids and modulates LPL and leptin receptor expression in rat placentas

2013 ◽  
Vol 217 (3) ◽  
pp. 303-315 ◽  
Author(s):  
M B Mazzucco ◽  
R Higa ◽  
E Capobianco ◽  
M Kurtz ◽  
A Jawerbaum ◽  
...  
Keyword(s):  
Leptin Receptor ◽  
Fetal Liver ◽  
Liver Lipid ◽  
Saturated Fat ◽  
Receptor Expression ◽  
Lipid Concentration ◽  
Old Rats ◽  
Liver Lipid Concentration ◽  
Leptin Expression ◽  
Layer Chromatography

Metabolic alterations in obese and overweight mothers impact the placenta and the fetus, leading to anomalies in fetal growth and lipid accretion. The primary aim of the study was to examine the effect of a saturated fat-rich diet (FD) on growth, lipid accretion, and lipases, leptin and leptin receptor (ObR) expression in the placenta and fetal liver. We also aimed to find a role for fetal leptin in the modulation of placental and fetal liver lipase and ObR expression. Six-week-old rats were fed with a standard rat chow (control) or a 25% FD for 7 weeks until mating and during pregnancy. Also, in a group of control rats, fetuses were injected with leptin on days 19, 20, and 21 of pregnancy. On day 21, we assessed lipidemia, insulinemia, and leptinemia in mothers and fetuses. In the placenta and fetal liver, lipid concentration was assessed by thin layer chromatography (TLC) and the gene expression of lipoprotein lipase (LPL), endothelial lipase, insulin receptor (Insr), leptin, and ObR by RT-PCR. The FD induced hypertriglyceridemia and hyperleptinemia (P<0.01) in mothers and fetuses, an increase in maternal (P<0.05) and fetal weight (P<0.01), overaccumulation of lipids in fetal liver (P<0.01), and enhanced leptin expression in the placenta and fetal liver (P<0.05). Placental expression of IR and LPL was increased (P<0.05), and ObR decreased (P<0.05) in the FD group. Fetal administration of leptin induced the placental and fetal liver downregulation of ObR (P<0.05) and upregulation of LPL expression (P<0.05). The FD led to increased fetal lipid levels, which may result from high maternal lipid availability and fetal leptin effects.

scholarly journals Maternal low-protein diet programmes offspring growth in association with alterations in yolk leptin deposition and gene expression in yolk-sac membrane, hypothalamus and muscle of developing Langshan chicken embryos

2009 ◽  
Vol 102 (6) ◽  
pp. 848-857 ◽  
Author(s):  
Kaiqing Rao ◽  
Jingjing Xie ◽  
Xiaojing Yang ◽  
Lei Chen ◽  
Roland Grossmann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Leptin Receptor ◽  
Pectoralis Major Muscle ◽  
Yolk Sac ◽  
Pectoralis Major ◽  
The Body ◽  
Low Protein ◽  
Igf I ◽  
Offspring Growth

The present study was aimed to investigate the mechanism underlying the influence of maternal low-protein (LP) diet on offspring growth in the chicken. One hundred and twenty Chinese inbred Langshan breeder hens were allocated randomly into two groups fed diets containing low (10 %, LP) or normal (15 %) crude protein levels. Low dietary protein did not affect the body weight of hens, but significantly decreased the laying rate and egg weight. The yolk leptin content was significantly lower in eggs laid by LP hens, while no differences were detected for yolk contents of corticosterone, tri-iodothyronine (T3) or thyroxine. Despite significantly lower hatch weight, the LP offspring demonstrated obviously higher serum T3 concentration, which is in accordance with the faster post-hatch growth rate achieving significantly heavier body weight and pectoralis major muscle weight 4 weeks post-hatching. Expression of 20-hydroxysteroid dehydrogenase (20-HSD) mRNA in the yolk-sac membrane was significantly down-regulated at embryonic day 14, whereas that of transthyretin and leptin receptor (LepR) was not altered. Moreover, hypothalamic expression of 20-HSD, glucocorticoid receptors, thyrotropin-releasing hormone and LepR mRNA was significantly up-regulated in the LP group compared with their control counterparts. In the pectoralis major muscle, significantly higher expression of insulin-like growth factor (IGF)-I and IGF-I receptor mRNA was observed in LP embryos. The present study provides evidence that maternal LP diet programmes post-hatch growth of the offspring. The associated alterations in yolk leptin deposition as well as in yolk-sac membrane, fetal hypothalamus and muscle gene expression may be involved in mediating such programming effect in the chicken.

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