Low transformation growth factor-β1 production and collagen synthesis correlate with the lack of hepatic periportal fibrosis development in undernourished mice infected with Schistosoma mansoni

Abstract

Undernourished mice infected (UI) submitted to low and long-lasting infections by Schistosoma mansoni are unable to develop the hepatic periportal fibrosis that is equivalent to Symmers’ fibrosis in humans. In this report, the effects of the host’s nutritional status on parasite (worm load, egg viability and maturation) and host (growth curves, biology, collagen synthesis and characteristics of the immunological response) were studied and these are considered as interdependent factors influencing the amount and distribution of fibrous tissue in hepatic periovular granulomas and portal spaces. The nutritional status of the host influenced the low body weight and low parasite burden detected in UI mice as well as the number, viability and maturation of released eggs. The reduced oviposition and increased number of degenerated or dead eggs were associated with low protein synthesis detected in deficient hosts, which likely induced the observed decrease in transformation growth factor (TGF)-β1 and liver collagen. Despite the reduced number of mature eggs in UI mice, the activation of TGF-β1 and hepatic stellate cells occurred regardless of the unviability of most miracidia, due to stimulation by fibrogenic proteins and eggshell glycoproteins. However, changes in the repair mechanisms influenced by the nutritional status in deficient animals may account for the decreased liver collagen detected in the present study.

Malondialdehyde; Lipid peroxidation plasma biomarker correlated with hepatic fibrosis in human Schistosoma mansoni infection

“…To eliminate the assumed nutritional status influence on Schistosoma induced hepatic fibrosis (Coutinho et al 2005;Coutinho et al 2007; Barros et al 2014), We calculated body mass index (BMI) for determination of nutritional status of patients. BMI was calculated as weight in kg divided by the square of height, the weight measured in kilograms using a standing scale with precision margin of 0.5 kg, and the height measured barefooted in centimeter, using non-stretchable standard measuring wall fixed tape (Coutinho et al 2005).…”

Nutritional status and immune response in murine experimental Jorge Lobo's disease

“…Malnutrition is recognised as the main cause of acquired immunosuppression in the world and can increase the incidence of morbidity and mortality due to infections . These deleterious effects on immune function have been demonstrated clinically and in experimental studies on different diseases …”

“…2,3 These deleterious effects on immune function have been demonstrated clinically and in experimental studies on different diseases. [6][7][8][9][10] In experimental studies of PCM, body weight is one of the most widely used indicator for the assessment of nutritional status since it represents the sum of all components of each level of body composition. 1 Since body weight is an approximate measure of the body's total energy reserves, it is a valuable tool for the monitoring and prognosis of infections.…”

“…The triad of nutrition, infection and immunity has been demonstrated in several studies on mice infected with Toxoplasma gondii , Schistosoma mansoni , Leishmania chagasi , Staphylococcus aureus and Mycobacterium tuberculosis, however, there are no studies investigating nutritional and immunological aspects in Jorge Lobo's disease.…”

“…Regardless of the cause, malnutrition can compromise the immune system which will contribute substantially to increased susceptibility to the installation of infectious agents, causing more severe infections and mortality. [1][2][3][4] The triad of nutrition, infection and immunity has been demonstrated in several studies on mice infected with Toxoplasma gondii, 5 Schistosoma mansoni, 6 Leishmania chagasi, 7 Staphylococcus aureus 8 and Mycobacterium tuberculosis, 9,10 however, there are no studies investigating nutritional and immunological aspects in Jorge Lobo's disease.…”