leptin and Staphylococcal-Infections

During infection, inflammatory monocytes are thought to be key for bacterial eradication, but this is hard to reconcile with the large numbers of neutrophils that are recruited for each monocyte that migrates to the afflicted tissue, and the much more robust microbicidal functions of the neutrophils. However, unlike neutrophils, monocytes have the capacity to convert to situationally specific macrophages that may have critical functions beyond infection control

Topics: Adipocytes; Animals; Cicatrix; Ghrelin; Leptin; Macrophages; Mice; Monocytes; Neovascularization, Physiologic; Neutrophils; Staphylococcal Infections; Staphylococcus aureus; Wound Healing

A recent article by Kratofil et al. investigated the immune inflammatory response against Staphylococcus aureus-contaminated foreign bodies placed under mouse skin. In this model, neutrophils are indispensable for bacterial clearance, while monocyte-derived macrophages are required for optimal wound healing. Intriguingly, ghrelin produced by macrophages favors, and leptin produced by hypodermal adipocytes inhibits, an adequate foreign body response.

Topics: Animals; Ghrelin; Leptin; Mice; Neutrophils; Staphylococcal Infections; Wound Healing

Circulating leptin concentrations are raised in animal models of inflammation and sepsis and leptin production is also increased in rodents by administration of endotoxin or cytokines. The purpose of this study was to investigate the effect of sepsis on serum leptin concentration and whether circulating leptin was related to tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) release in newborn infants. Plasma leptin, TNF-alpha and IL-6 were measured in 20 neonates with culture-proven sepsis as soon as sepsis was diagnosed and after recovery and in 15 healthy control infants. There was no significant difference in plasma leptin levels between septic and control infants (p > 0.05); there was also no difference in plasma leptin levels in septic neonates before and after therapy (p > 0.05). No relationship between leptin and TNF-alpha (r = 0.16, p > 0.05) or IL-6 (r = 0.12, p > 0.05) was identified. These findings suggest that a major role of leptin in acute neonatal sepsis appears unlikely.

Topics: Anti-Bacterial Agents; Body Mass Index; Candida albicans; Candidiasis; Escherichia coli Infections; Female; Humans; Infant, Newborn; Interleukin-6; Klebsiella Infections; Leptin; Male; Sepsis; Staphylococcal Infections; Tumor Necrosis Factor-alpha

Weight loss is typically found during severe infections, e.g. septic arthritis. The aim of our study was to evaluate the role of leptin, regulator of food intake and energy expenditure, for the development of Staphylococcus aureus-triggered arthritis. Leptin production was found to be decreased during murine S. aureus-induced arthritis. Treatment with recombinant leptin neither restored the basal leptin levels nor affected the weight loss during the disease, but it significantly decreased the severity of septic arthritis. Exogenous leptin did not affect the staphylococcal load as measured in blood, joints and kidneys. Preceding the effects on joint manifestations, serum levels of interleukin-6 decreased in leptin-treated mice. In conclusion, the treatment with recombinant leptin reduced both the severity of joint manifestations in S.aureus-induced arthritis and the inflammatory response, as measured by serum IL-6 levels, without affecting the survival of bacteria in vivo.

Topics: Animals; Arthritis, Infectious; Eating; Energy Metabolism; Interleukin-6; Leptin; Male; Mice; Mice, Inbred C57BL; Staphylococcal Infections; Staphylococcus aureus; Weight Loss