Light and confocal microscopic observations of adultSchistosoma mansonifrom mice fed on a high-fat diet

Abstract

The morphological aspects of Schistosoma mansoni adult worms recovered from albino mice fed on a cholesterol-rich diet compared to mice fed on a standard chow were investigated. After feeding on their respective diets for over a period of 5 months, mice were subcutaneously infected with c. 50 S. mansoni cercariae/mouse. Blood samples were obtained 1 day prior to experimental infections and 63 days later, when mice were euthanized by jugular section (hypovolaemic shock). Total cholesterol (TC) levels were determined. Recovered worms were stained with hydrochloric carmine, and preserved as whole-mounts for examination by bright-field and laser confocal microscopy. The infected mice fed on high-fat chow showed higher levels of serum lipoproteins than the infected mice fed on standard chow, except for very-low-density lipoprotein cholesterol (VLDL-c) and triglycerides (TG). In this experiment, worms from mice fed on a high-fat chow showed a greater percentage of morphological differentiation regarding supernumerary testes, seminal vesicle, and seminal receptacle. In mice of this group, the rate of oocyte laying in the ovary was much higher than in control females. The present results suggest that cholesterol could be actively involved in the modulation of cell signalling and reproduction, because the lobes contained fully developed oocytes in variable amounts, different from control males. The data presented here are the first to report the role of a cholesterol-rich diet affecting the development of S. mansoni worms.

High fat diet has a prominent effect upon the course of chronic schistosomiasis mansoni in mice

“…These data suggest that schistosomes are closely associated with the modulation of host lipid metabolism (El Ridi et al 2004, Tallima & El Ridi 2005. The most plausible explanation is the presence of signalling pathways by which parasites detect host signals and respond to them in a way that presumably both increases their survival (Loverde et al 2007) and reproduction of adult worms (Neves et al 2007a). In this study, regression and linear correlation between faecal eggs and worm pairs found no correlation in the IHFC group.…”

“…Chronic exposure to schistosome eggs promoted the development of a Th2 response and reduced the levels of total cholesterol and LDL in serum, but it failed to reduce aortic lesion development (La Flamme et al 2007). As part of a series of studies being carried out in our laboratories on the role of dyslipidaemia during acute schistosomiasis infection, it was observed that a high-fat diet favours the development of adult worms (Neves et al 2007a). Moreover, egg maturity, faecal output, viability and egg hatching were higher compared to mice fed a standard diet (Neves et al 2007b).…”

A critical analysis of three quantitative methods of assessment of hepatic steatosis in liver biopsies

“…A proposed scale was (−) not detected, (±) rare, (+) mild, (++) moderate, and (+++) intense [38]. Because increased steatosis has been associated with increased fibrosis, I-A may also be helpful in measuring fibrosis [39], mainly if slices are stained by picrosirius red to enhance the collagen fibers [40,41]. The I-A is particularly important if we consider that today images are captured by digital cameras and image handling is done entirely within the computer [42].…”

The outcome of acute schistosomiasis infection in adult mice with postnatal exposure to maternal malnutrition

“…Prolonged feeding of fat-enriched diets induces hepatic steatosis in rodents (Zhang et al 1999, Rao et al 2001, Picard et al 2002, Buettner et al 2007, Marques et al 2010). During S. mansoni infection, immunocompromised mice fed either a normal diet (Doenhoff et al 1981) or high-fat chow (Neves et al 2007a) developed hepatic steatosis. Alternatively, PR throughout gestation and during the first half of lactation has caused higher rates of hepatic steatosis in six-month-old rats (Souza-Mello et al 2007).…”