The Role of Gut Microbiota and Diet on Uremic Retention Solutes Production in the Context of Chronic Kidney Disease

Uremic retention solutes (URS) are associated with cardiovascular complications and poor survival in chronic kidney disease. The better understanding of the origin of a certain number of these toxins enabled the development of new strategies to reduce their production. URS can be classified according to their origins (i.e., host, microbial, or exogenous). The discovery of the fundamental role that the intestinal microbiota plays in the production of many URS has reinstated nutrition at the heart of therapeutics to prevent the accumulation of URS and their deleterious effects. The intestinal microbiota is personalized and is strongly influenced by dietary habits, such as the quantity and the quality of dietary protein and fibers. Herein, this review out lines the role of intestinal microbiota on URS production and the recent discoveries on the effect of diet composition on the microbial balance in the host with a focus on the effect on URS production

Total synthesis of cirsimarin and evidence of its lipolytic and antilipogenic activities on human adipocytes

International audienceA straightforward procedure leading to the flavone cirsimaritin and its 4′-O-β-d-glycosylation to afford cirsimarin, its corresponding flavone glucopyranoside, is described. The biological properties of cirsimarin, measured on human adipocytes, showed potent effects on both lipolysis and lipogenesis. Cirsimarin could therefore be considered as an efficient tool in the struggle against excessive adipose tissue deposition and as a potential candidate in the treatment of obesity

Total synthesis of cirsimarin and evidence of its lipolytic and antilipogenic activities on human adipocytes

International audienceA straightforward procedure leading to the flavone cirsimaritin and its 4′-O-β-d-glycosylation to afford cirsimarin, its corresponding flavone glucopyranoside, is described. The biological properties of cirsimarin, measured on human adipocytes, showed potent effects on both lipolysis and lipogenesis. Cirsimarin could therefore be considered as an efficient tool in the struggle against excessive adipose tissue deposition and as a potential candidate in the treatment of obesity

Modified Lipids and Lipoproteins in Chronic Kidney Disease: A New Class of Uremic Toxins

Chronic kidney disease (CKD) is associated with an enhanced oxidative stress and deep modifications in lipid and lipoprotein metabolism. First, many oxidized lipids accumulate in CKD and were shown to exert toxic effects on cells and tissues. These lipids are known to interfere with many cell functions and to be pro-apoptotic and pro-inflammatory, especially in the cardiovascular system. Some, like F2-isoprostanes, are directly correlated with CKD progression. Their accumulation, added to their noxious effects, rendered their nomination as uremic toxins credible. Similarly, lipoproteins are deeply altered by CKD modifications, either in their metabolism or composition. These impairments lead to impaired effects of HDL on their normal effectors and may strongly participate in accelerated atherosclerosis and failure of statins in end-stage renal disease patients. This review describes the impact of oxidized lipids and other modifications in the natural history of CKD and its complications. Moreover, this review focuses on the modifications of lipoproteins and their impact on the emergence of cardiovascular diseases in CKD as well as the appropriateness of considering them as actual mediators of uremic toxicity

Human Uremic Plasma and not Urea Induces Exuberant Secretion of Leptin in 3T3-L1 Adipocytes

International audienceChronic kidney disease (CKD) is frequently associated with malnutrition, anorexia, and hyperleptinemia. This study was designed to test the hypothesis that a component of the uremic milieu may trigger leptin release by adipocytes. To this end, mouse 3T3-L1 adipocytes were incubated for 16 hours in culture medium containing urea (80 mM) or plasma from either healthy volunteers or patients with CKD (20%, v/v). Uremic plasma and not urea induced a large release of leptin (1557%, P < .01). These results suggest that the hyperleptinemia reported in patients with CKD, could be, at least in part, because of an overproduction of leptin by the adipose tissue. (C) 2011 by the National Kidney Foundation, Inc. All rights reserved

Simulated evolution of body weight (red line) compared to experimental data (mean standard deviation in black).

<p>In each group, the food input matches the experimental patterns and the first 5 days of the simulation were conducted with <i>Ad libitum</i> diet to be closer to the experiment. Parameter values were estimated with data from groups AL and H1 and predictions were made with these parameter values on groups H0 and H4. Top left: AL; top right: H0; bottom left: H1; bottom right: H4.</p

The acoustic expression of stress in a songbird : Does corticosterone drive isolaion-induced modifications of zebra finch call ?

International audienceAnimal vocalizations convey multiple pieces of information about the sender. Some of them are stable, such as identity or sex, but others are labile like the emotional or motivational state. Only a few studies have examined the acoustic expression of emotional state in non-human animals and related vocal cues to physiological parameters. In this paper, we examined the vocal expression of isolation-induced stress in a songbird, the zebra finch (Taeniopygia guttata). Although songbirds use acoustic communication extensively, nothing is known to date on how they might encode physiological states in their vocalizations. We tested the hypothesis that social isolation in zebra finches induces a rise of plasma corticosterone that modifies the vocal behavior. We monitored plasma corticosterone, as well as call rate and acoustic structure of calls of males in response to the playback of female calls of varied saliences (familiar versus stranger) in two situations: social isolation and social housing. Social isolation induced both a rise in plasma corticosterone, and a range of modifications in males' vocal behavior. Isolated birds showed a lower vocal activity, an abolition of the difference of response between the two stimuli, and evoked calls with longer duration and higher pitch. Because some of these effects were mimicked after oral administration of corticosterone in socially housed subjects, we conclude that corticosterone could be partly responsible for the isolation-related modifications of calls in male zebra finches. To our knowledge, this is the first demonstration of the direct implication of glucocorticoids in the modulation of the structure of vocal sounds

Corticosterone triggers high-pitched nestlings\u27 begging calls and affects parental behavior in the wild zebra finch

International audienceNestlings beg to parents to communicate their need. Nevertheless, the specific signal driving parental care remains only partially understood. No study to date has been able to link a specific change in the physiological state of the young with, on the one hand, the modulation of a precise component of its begging behavior and, on the other hand, a direct modification of parental behavior reflecting an adjustment to an appropriate level of care. Here we orally administrated either exogenous corticosterone or a peanut oil control to free-living zebra finch nestlings and recorded begging behavior directly after treatment. Using a continuous automated monitoring system to record parental behavior in the wild, we simultaneously monitored the rate and duration of parental nest visits and foraging behavior at artificial feeders during 6 days posttreatment. We show that corticosterone modified the begging calls’ spectrum. Parents of corticosterone-treated broods spent more time in the nest and in feeders, and their older nestlings gained more body mass. Begging calls thus show a corticosterone-driven flexibility, which may inform parents of nestlings’ physiological state and allow them to provide an appropriate level of care