Effect of 50 Hz electric field in diacylglycerol acyltransferase mRNA expression level and plasma concentration of triacylglycerol, free fatty acid, phospholipid and total cholesterol.

BACKGROUND: The effects of exposure to a 50 Hz electric field (EF) on plasma level of triacylglycerol, free fatty acids, total cholesterol and phospholipid and mRNA expression level of diacylglycerol acyltransferase (DGAT) 1 and 2 in liver and intestines from C57BL/6 J mice were studied. METHODS: The test was based on comparison between mice post treated with 50 Hz EF of 45 kV/m intensity for 30 min per day for 11 days or without EF. DGATs mRNA expression was analyzed by real-time quantitative polymerase chain reaction. RESULTS: There was no difference in the gene expression level of DGAT1 in liver and intestines. The DGAT2 gene expression level in liver derived from mice treated with EF was significantly lower than those in the control (P < 0.001). Both plasma total cholesterol (P < 0.01) and phospholipid (P < 0.05) in the group exposed to EF were lower than those in the control, but there was no difference in triacylglycerol or free fatty acid levels. CONCLUSION: Exposure to 50 Hz EF decrease the plasma levels of total cholesterol and phospholipids, and downregulated DGAT2 mRNA expression in liver. The mechanisms for the effects of EF on lipid metabolism are not well understand yet, but altered DGAT2 activity may be involved.

Expression of erythropoietic cytokines in α-tocopherol transfer protein knockout mice with murine malaria infection.

Malaria infection leads to anemia in humans which generally occurs during the chronic phase of the infection. The role that erythropoietic molecules play for anemia during malaria at low parasitemia levels is still controversial due to the lack of suitable animal models which might mimic this condition. In this regard, α-tocopherol transfer protein knockout mice, with undetectable levels of vitamin E in circulation, were possibly used as a model to investigate the role that erythropoietic molecules such as erythropoietin (EPO), erythropoietin receptor (EPOR), and macrophage migration inhibitory factor (MIF) play on the outcome of anemia during uncomplicated malaria infection at low parasitemias. The results indicate that the degree of parasitemia unlikely plays any important effect on mRNA expression of EPO and EPOR in different organs. Moreover, even though EPO and EPOR productions are impaired in the kidney and bone marrow, respectively, other organs such as the liver and spleen intend to compensate production of these cytokines to prevent anemia in the infected animals.

Alpha-tocopherol transfer protein disruption confers resistance to malarial infection in mice.

BACKGROUND: Various factors impact the severity of malaria, including the nutritional status of the host. Vitamin E, an intra and extracellular anti-oxidant, is one such nutrient whose absence was shown previously to negatively affect Plasmodium development. However, mechanisms of this Plasmodium inhibition, in addition to means by which to exploit this finding as a therapeutic strategy, remain unclear. METHODS: alpha-TTP knockout mice were infected with Plasmodium berghei NK65 or Plasmodium yoelii XL-17, parasitaemia, survival rate were monitored. In one part of the experiments mice were fed with a supplemented diet of vitamin E and then infected. In addition, parasite DNA damage was monitored by means of comet assay and 8-OHdG test. Moreover, infected mice were treated with chloroquine and parasitaemia and survival rate were monitored. RESULTS: Inhibition of alpha-tocopherol transfer protein (alpha-TTP), a determinant of vitamin E concentration in circulation, confers resistance to malarial infection as a result of oxidative damage to the parasites. Furthermore, in combination with the anti-malarial drug chloroquine results were even more dramatic. CONCLUSION: Considering that these knockout mice lack observable negative impacts typical of vitamin E deficiency, these results suggest that inhibition of alpha-TTP activity in the liver may be a useful strategy in the prevention and treatment of malaria infection. Moreover, a combined strategy of alpha-TTP inhibition and chloroquine treatment might be effective against drug resistant parasites.