Mir-190b negatively contributes to the Trypanosoma cruzi -infected cell survival by repressing PTEN protein expression

Chagas disease, which is caused by the intracellular protozoan Trypanosoma cruzi , is a serious health problem in Latin America. The heart is one of the major organs affected by this parasitic infection. The pathogenesis of tissue remodelling, particularly regarding cardiomyocyte behaviour after parasite infection, and the molecular mechanisms that occur immediately following parasite entry into host cells are not yet completely understood. Previous studies have reported that the establishment of parasitism is connected to the activation of the phosphatidylinositol- 3 kinase (PI3K), which controls important steps in cellular metabolism by regulating the production of the second messenger phosphatidylinositol-3,4,5-trisphosphate. Particularly, the tumour suppressor PTEN is a negative regulator of PI3K signalling. However, mechanistic details of the modulatory activity of PTEN on Chagas disease have not been elucidated. To address this question, H9c2 cells were infected with T. cruzi Berenice 62 strain and the expression of a specific set of microRNAs (miRNAs) were investigated. Our cellular model demonstrated that miRNA-190b is correlated to the decrease of cellular viability rates by negatively modulating PTEN protein expression in T. cruzi-infected cells.

Cytotoxic, anti-inflammatory and antioxidant activities of four different extracts of Galega officinalis L (Goat’s rue)

Purpose: To evaluate the cytotoxic, anti-inflammatory and antioxidant activities of four different solvent extracts obtained from the aerial parts of Galega officinalis L Methods: The hexane, DCM, methanol and water extracts of G. officinalis were successively obtained by soxhlet extraction method. The cytotoxic activity of the extracts was assessed against human lung carcinoma (A-549), human colorectal adenocarcinoma (HT-29), human brain glioblastoma (U-87), and colon adenocarcinoma (DLD-1) by Resazurine test. The antioxidant activity of extracts were determined by Folin-Ciocalteau, oxygen radical absorbing capacity (ORAC), and 2’.7’-dichlorofluorescin-diacetate (DCFH-DA) cell-based assay while their anti-inflammatory activity was determined by nitric oxide (NO) assay. Results: DCM extract showed strong cytotoxic activity against lung adenocarcinoma and brain glioblastoma cell lines, with IC50 (concentration inhibiting 50 % of cell growth) values of 11 ± 0.4 and 16 ± 3 μg/mL, respectively. The hexane extract showed moderate anticancer activity against the same cell lines (59 ± 13 and 63 ± 16 μg/mL, respectively). DCM extract also showed significant anti-inflammatory activity, inhibiting NO release by 86.7 % at 40 μg/mL in lipopolysaccharide (LPS) - stimulated murine RAW 264.7 macrophages. Of all test extracts, the methanol extract of G. officinalis showed the highest antioxidant activity with 2.33 ± 0.09 μmol Trolox/mg , 7.10 ± 0.9 g tannic acid equivalent (TAE), and IC50 of 44 ± 4 μg/mL. Conclusion: The findings of this study suggest that DCM extract may possess anticancer effect against lung adenocarcinoma and brain glioblastoma, as well as serve as an anti-inflammatory agent.

Autophagy in photodynamic therapy

Macroautophagy (autophagy) is crucial for cell survival during starvation and plays important roles in human diseases. It is a highly conserved intracellular degradation system in eukaryotes for removal and recycling of cytoplasmic components including damaged proteins and organelles to obtain energy. The relationship between cancer and autophagy has been extensively studied in recent years. In cancer and cancer therapy, autophagy acts as a double-edged sword. Photodynamic therapy (PDT) is a kind of tumor therapy applied with a tumor-localizing photosensitizing agent which is followed by activation with the light of a specific wavelength. How much is autophagy involved in photodynamic therapy? The work in this area is still limited.