RESUMO
In this study, the effects of selenium on the microalgae Chlorella vulgaris were examined. Four groups of C. vulgaris were cultivated using Bristol medium: group I (control), no sodium selenite (Se); group II, 1 µM Se; group III, 10 µM Se; and group IV, 100 µM Se. Algal biomass samples were collected for biochemical evaluation and gene expression studies on the 21st day of cultivation. The following parameters were investigated: chlorophyll a (Cla), chlorophyll b (Clb) and total carotene content, total protein, and total glutathione (GSH) and malondialdehyde (MDA) levels. Gene expression levels of large subunits of Rubisco (rbcL) were analyzed using real-time quantitative polymerase chain reaction. Total Cla and total carotene in C. vulgaris decreased in high concentrations of Se (100 µM) (around 23 and 42%, respectively) when compared to controls while, Clb content increased by about 10%. 10 µM of Se led to increased GSH levels (3.04 ± 0.02 µg GSH/mg protein) and decreased MDA levels (2.02 ± 0.1 µmol MDA/mg protein) when compared to control groups (1.18 ± 0.04 µg GSH/mg protein and 0.94 ± 0.23 µmol MDA/mg protein), while a significant decrease in GSH and an increase in MDA levels in the presence of 100 µM Se showed the opposite effect. rbcL gene expression increased 1.76 ± 1.37-fold and 0.86 ± 1.33-fold in 10 and 100 µM selenium experiments when compared to control groups. Our results suggest both pro-oxidant and antioxidant activities of Se on C. vulgaris and upregulation of the rbcL gene for the first time. Treatment with low concentrations of Se improves the antioxidant features of the microalgae, C. vulgaris.
RESUMO
BACKGROUND: Neoangiogenesis inside the atherosclerotic plaques has been linked to progression of the disease. Egfl7, a key player in adult angiogenesis, was found to be upregulated in response to vascular injury in rats. Egfl7 encodes for miR-126-3p and miR-126-5p. Specific information about miRNA-126-5p and its expression in cardiovascular disease is scarce in comparison to that of miR-126-3p. OBJECTIVES: A gene expression study was conducted to investigate the levels of Egfl7 and miRNA126-5p in human carotid artery atherosclerotic plaques aiming to gain a better understanding of the role of neoangiogenesis within plaques and the mechanisms causing atherosclerosis progression. METHODS: Egfl7 and miR-126-5p levels were studied in 14 plaque samples and 14 control samples using real-time PCR. The fold change between the carotid artery plaque tissue and control tissue was calculated using the 2(-ΔΔCT) method. RESULTS: Egfl7 was upregulated in the 11 plaque samples compared to controls, while expression levels of miR-126-5p was higher in eight of the plaque samples and lower in six as compared to control samples. Upregulation of miR-126-5p expression was correlated with high low-density lipoprotein (LDL) cholesterol (p = 0.023). CONCLUSIONS: Our findings suggest that the upregulation of Egfl7 promotes neoangiogenesis within the plaques, contributing to disease progression.
