The concentration dependent biphasic effect of leptin on endogenous cholesterol synthesis in human monocytes

Balogh, Zoltán; Fóris, Gabriella; Kosztáczky, Béla; Paragh, György; Serés, I.; Zsíros, Emese; Kónya, Gabriella

doi:10.1016/j.peptides.2007.07.004

Cited by 11 publications

(6 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Later, it was found that leptin directly induces the secretion of interleukin 1 receptor antagonist in human monocytes [26] and upregulates IP-10 (interferon-gamma-inducible protein) in monocytic cells [27]. Moreover, in human monocytes it has been shown that leptin increased both statin-inhibitable free radical and cholesterol productions in vitro [28]. In addition, it accelerates cholesteryl ester accumulation in human monocyte-derived macrophages by increasing ACAT-1 expression via JAK2 and PI3K, thereby suppressing cholesterol efflux [29].…”

Section: Leptin Activation Of Innate Immunitymentioning

confidence: 99%

Role of Leptin in the Activation of Immune Cells

Fernández‐Riejos

Najib

Santos‐Álvarez

et al. 2010

Mediators of Inflammation

351

281

View full text Add to dashboard Cite

Adipose tissue is an active endocrine organ that secretes various humoral factors (adipokines), and its shift to production of proinflammatory cytokines in obesity likely contributes to the low-level systemic inflammation that may be present in metabolic syndrome-associated chronic pathologies such as atherosclerosis. Leptin is one of the most important hormones secreted by adipocytes, with a variety of physiological roles related to the control of metabolism and energy homeostasis. One of these functions is the connection between nutritional status and immune competence. The adipocyte-derived hormone leptin has been shown to regulate the immune response, innate and adaptive response, both in normal and pathological conditions. The role of leptin in regulating immune response has been assessed in vitro as well as in clinical studies. It has been shown that conditions of reduced leptin production are associated with increased infection susceptibility. Conversely, immune-mediated disorders such as autoimmune diseases are associated with increased secretion of leptin and production of proinflammatory pathogenic cytokines. Thus, leptin is a mediator of the inflammatory response.

show abstract

Section: Leptin Activation Of Innate Immunitymentioning

confidence: 99%

Role of Leptin in the Activation of Immune Cells

Fernández‐Riejos

Najib

Santos‐Álvarez

et al. 2010

Mediators of Inflammation

351

281

View full text Add to dashboard Cite

show abstract

“…Later, it was found that leptin directly induces the secretion of interleukin 1 receptor antagonist in human monocytes [23] and upregulates IP-10 (interferongamma-inducible protein) in monocytic cells [24]. Moreover, in human monocytes leptin increases both statininhibitable free radical and cholesterol production in vitro [25]. Leptin also augments leukotriene synthesis in alveolar macrophages [26].…”

Section: Leptin Regulation Of Monocytes/macrophagesmentioning

confidence: 99%

Role of Leptin in the Immune System

Fernandez-Riejos¹,

González-Yanes²,

Najib³

et al. 2008

CIR

View full text Add to dashboard Cite

Adipose tissue is no longer considered mere energy storage, but an important endocrine organ that produces many signals in a tightly regulated manner. Leptin is one of the most important hormones secreted by the adipocyte, with a variety of physiological roles related with the control of metabolism and energy homeostasis. One of these functions is the connection between nutritional status and immune competence. The adipocyte-derived hormone leptin has been shown to regulate the immune response both in normal as well as in pathological conditions. Leptin´s modulation of the immune system is exerted at the development, proliferation, anti-apoptotic, maturation, and activation levels. The role of leptin in regulating immune response has been assessed in vitro as well as in clinical studies. Both the innate and adaptative immune responses are regulated by leptin. Every cell type involved in immunity can be modulated by leptin. In fact, leptin receptors have been found in neutrophils, monocytes, and lymphocytes, as well as belonging to the family of class I cytokine receptors. Moreover, leptin activates similar signaling pathways to those engaged by other members of the family. The overall leptin action in the immune system is a proinflammatory effect, activating proinflammatory cells, promoting T-helper 1 responses, and mediating the production of the other proinflammatory cytokines, such as tumor necrosis factor-, interleukin (IL)-2, or IL-6. Leptin receptor is also upregulated by proinflammatory signals. It has been shown that conditions of reduced leptin production are associated with increased infection susceptibility. Conversely, immune-mediated disorders such as autoimmune diseases are associated with increased secretion of leptin and production of proinflammatory pathogenic cytokines. Thus, leptin is a mediator of the inflammatory response, and could have also a permissive role in the development of autoimmune diseases.

show abstract

“…The association between leptin and cardiovascular risk is complicated, because there are data on the protective role of leptin in cardiovascular risk as well as on proatherogenic properties of hyperleptinemia or leptin resistance . An experimental study in vitro demonstrated that low concentrations of leptin stimulate cholesterol synthesis in human monocytes . Low adiponectin levels may be associated with cholesterol synthesis by reduced activity of AMP‐activated kinase .…”

Section: Discussionmentioning

confidence: 99%

“…27,28 An experimental study in vitro demonstrated that low concentrations of leptin stimulate cholesterol synthesis in human monocytes. 29 Low adiponectin levels may be associated with cholesterol synthesis by reduced activity of AMP-activated kinase. 30 On the basis of our data that circulating levels of the two adipocytokines decrease after sleep fragmentation and that they are strongly correlated with LDL-C levels, we predispose their effects on cholesterol synthesis.…”

mentioning

confidence: 99%

Sleep fragmentation affects LDL-cholesterol and adipocytokines independent of food intake in rats

Baik

Jun

Yoon

et al. 2013

Sleep and Biological Rhythms

View full text Add to dashboard Cite

To explore biological mechanisms underlying the association between sleep fragmentation and hypercholesterolemia, we conducted an experimental study with 36 Wistar male rats aged 7 weeks. An experimental model for 4-day subchronic sleep fragmentation was applied to rats which were fed ad libitum or were given 50% restricted amount of standard chow. Sleep fragmentation was induced by a treadmill which moved intermittently for 3 s with 30-second pauses between moves. Blood lipid and lipoprotein profiles and adiponectin, leptin, ghrelin, cortisol, epinephrine, and norepinephrine levels were compared among four groups including rats with ad libitum sleep and ad libitum intake (Control), those exposed to sleep fragmentation with ad libitum intake (SF), those with ad libitum sleep and diet restriction (DR), and those exposed to sleep fragmentation and diet restriction (SF+DR). SF and SF+DR showed a higher ratio of LDL and HDL cholesterol (184% and 132% increase, P-value for SF effects <0.001) and ghrelin (64% and 18% increase, P-value for SF effects <0.01) and lower leptin (76% and 44% decrease, P-value for SF effects <0.001) and adiponectin levels (3% and 18% decrease, P-value for SF effects <0.01) than Control. The LDL and HDL cholesterol ratio was highly correlated with leptin (rho = -0.92, P-value <0.001) and ghrelin (rho = 0.53, P-value <0.05) in Control and DR as well as with adiponectin (rho = -0.85, P-value <0.001) and leptin (rho = -0.60, P-value <0.01) in SF and SF+DR. Based on these findings, we suggest that sleep fragmentation may induce lipoprotein disturbances independent of food intake with decreased levels of adiponectin and leptin.

show abstract

The concentration dependent biphasic effect of leptin on endogenous cholesterol synthesis in human monocytes

Cited by 11 publications

References 9 publications

Role of Leptin in the Activation of Immune Cells

Role of Leptin in the Activation of Immune Cells

Role of Leptin in the Immune System

Sleep fragmentation affects LDL-cholesterol and adipocytokines independent of food intake in rats

Contact Info

Product

Resources

About