Selective elimination of younger erythrocytes in blood circulation and associated molecular changes in benzo (a) pyrene induced mouse model of lung cancer.

Background: Anemia is a common feature in cancer patients. The present research was conducted to explore the mechanisms of induction of anemia in a mouse model of lung cancer. Methods: The lung cancer was induced by treating orally with BaP (50 mg/kg body weight, twice a week for four weeks). The erythrocyte kinetics were studied using a double in vivo biotinylation (DIB) technique. ROS production and apoptosis analysis were done by staining with the CMH2DCFDA stain and anti-mouse Annexin V antibody, followed by flow cytometry. The expression of antioxidant, apoptotic, anti-apoptotic and inflammatory genes was analyzed by quantitative PCR (RT-qPCR). Results: BaP-induced tumour reduced body weight and induced persistent haemolytic anaemia. The kinetics data suggest that, though reticulocyte production was enhanced, the proportion of young erythrocytes did not increase in the same proportion. The young aged erythrocytes were selectively eliminated from blood circulation, but intermediate and old aged erythrocytes persisted for a longer duration. The tumour progression leads to a significant increase in ROS production and apoptosis in the erythrocytes. The molecular data suggests that the expression levels of antioxidants (SOD1, catalase, and GPX1) and erythropoietin (Epo) were significantly increased. The anti-inflammatory genes Interleukin-6 (IL-6), Interleukin-10 (IL-10) were significantly decreased.Apoptotic genes Bax, and caspase 3 were significantly decreased while Bcl 2 was significantly increased in the blood of tumour-bearing mice. Conclusions: The overall data suggest that erythrocyte turnover is severely modulated with the progression of tumor. The apoptosis, ROS levels, antioxidant, anti-apoptotic, and Epo gene expressions were increased, but proapoptotic and anti-inflammatory gene expression were suppressed.

Aflatoxin B1 administration causes inflammation and apoptosis in the lungs and spleen.

Aflatoxin is a naturally occurring mycotoxin that has numerous toxic effects. The main aim of the present study was to evaluate the toxic effects of aflatoxin B1 (AFB1) on the lungs and spleen. Mice were repeatedly exposed to AFB1 (0.3 mg/kg body weight) on alternate days for four weeks via oral route. The histopathological data in AFB1-treated mice show alveolar epithelial hyperplasia with inflammation and the presence of numerous alveolar macrophages with minimal hemorrhage. There was an increase in vascular neutrophils and interstitial inflammation. The branching of vessels was plugged with neutrophils. AFB1 administration also causes splenomegaly. The AFB1-treated spleen shows the tingible body macrophages (TBM) scattered within the splenic white pulp. Apoptosis may lead to atrophy in a selected region of the white pulp area. There is a decrease in cellularity within the periarteriolar lymphatic sheath (PALS). The inflammation causes the congestion of red pulp with the increase in nuclear debris, and vacuoles are also visible. The flow cytometry data further suggests enhanced apoptosis in lung and spleen cells.

Aflatoxin B1 administration induces reactive oxygen species production and apoptosis of erythrocytes in mice.

Aflatoxin is a naturally occurring mycotoxin that has various toxic effects to humans and various other animals. In the current study, we have investigated the toxic effects of Aflatoxin B1 (AFB1) on erythrocytes in the blood circulation of mice. Mice were administered orally with repeated doses of AFB1 (0.3 mg/kg of body weight three times a week for four weeks). AFB1 administration resulted in sustained anemia and a significant reduction in blood erythrocyte number as well as hemoglobin level was seen at different time schedules. Body weight, erythrocyte count, and Hb were significantly decreased on days 30 and 45 post-AFB1 administration. The reticulocytes proportion in circulation was analyzed by staining the cells with anti-mouse CD71 monoclonal antibody and flow cytometric analysis. The ROS level and apoptotic cell proportion were determined by staining with CM-H2DCFDA and Annexin V antibody. AFB1 treatment leads to an increment in reticulocytes production. A significant increase in reactive oxygen species (ROS) and apoptotic cells were also observed in erythrocytes.