Shadia A. Fathy

Diagnostic utility of BNP, corin and furin as biomarkers for cardiovascular complications in type 2 diabetes mellitus patients.

Abstract Context: The number of patients with type 2 diabetes mellitus (T2DM) is progressively increasing, and diabetic cardiovascular complications have become a public health problem. Brain or B-type natriuretic peptide (BNP) is a cardiac hormone synthesized as a pre-pro-peptide. pro-BNP is produced by cleaving the signal peptide then two proprotein convertases, corin and furin cleave pro-BNP to form a biologically active hormone. Two corin single nucleotide polymorphisms (SNPs) have been reported to alter corin protein conformation and impair its biological activity. Objective: We aimed to investigate the potential role of corin and furin in comparison to BNP as biomarkers for predicting cardiovascular complications in T2DM patients. The association of corin gene SNPs with corin levels was also examined. Methods: Seventy-five subjects were recruited in this study, including 25 T2DM patients with complications, 25 T2DM patients without complications as well as 25 healthy subjects. Plasma BNP, corin and furin levels were measured using enzyme-linked immunosorbent assays. Two corin SNPs were genotyped using allele specific oligonucleotide-polymerase chain reaction. Results: Both furin and BNP were found to be more sensitive than corin (80% versus 56%, p = 0.008), whereas furin showed higher specificity when compared to BNP (96% versus 84%, p = 0.041) and corin (96% versus 64%, p < 0.0001) in predicting cardiovascular complications in T2DM patients. Corin SNPs are not associated with corin levels, neither in the entire study cohort nor in the subgroup of T2DM patients with cardiovascular complications (p > 0.05). Conclusions: Furin may be useful, either alone or in combination with other biomarkers, for cardiovascular risk stratification assessment in T2DM patients.

Possible Role of microRNA-122 in Modulating Multidrug Resistance of Hepatocellular Carcinoma

Abstract Hepatocellular carcinoma (HCC) is a hypervascular primary liver cancer characterized by rapid progression, besides, resistance to traditional chemotherapeutic agents. It has been shown that microRNAs play critical roles in regulation of tumor cell sensitivity to drugs through modulating the expression of genes involved in drug transport. The present study investigated whether restoration of miR-122 in HCC cells could alter the cell cycle distribution and the expression of multidrug resistance (MDR)-related genes (ABCB1, ABCC1, ABCG2 and ABCF2). After overexpression of miR-122 in HepG2 cells treated or untreated with doxorubicin doses, total RNAs and protein extracts were isolated for application of QRT-PCR and western blotting techniques. Moreover, cell cycle distribution was monitored by flow cytometry. Our results revealed that, the over expression of miR-122 in HepG2 cells treated or untreated with doxorubicin could modulate the sensitivity of cells to chemotherapeutic drug through downregulation of MDR-related genes, ABCB1 and ABCF2. Interpretation of cell cycle distribution revealed that, the anti-proliferative effect of miR-122 is associated with the accumulation of cells in G0/G1 phase. Moreover, treatment with miR-122 and doxorubicin resulted in high percentage of HCC cells in G0/G1 phase. Taken together, our findings revealed that, overexpression of miR-122 inhibited HCC cell growth by inducing cell cycle arrest and this arrest is associated with down-regulation of MDR-related genes.

Purification and characterization of a novel tannase produced by Kluyveromyces marxianus using olive pomace as solid support, and its promising role in gallic acid production

Tannase is considered one of the most important industrial enzymes that find great applications in various sectors. Production of tannases through solid state fermentation (SSF) using agro-industrial wastes is an eco-friendly and cheap technology. Tannase was produced by the yeast Kluyveromyces marxianus using olive pomace as a solid support under SSF. It was purified using ammonium sulfate fractional precipitation followed by Sephadex G-200 gel filtration resulting in 64.6% enzyme yield with 1026.12U/mg specific activity and 24.21 purification fold. Pure tannase had molecular weight of 65 KDa and 66.62 KDa by SDS-PAGE and gel filtration, respectively. It showed a maximal activity at 35°C having two different pH optima, one of which is acidic (4.5) and the other one is alkaline (8.5). The enzyme was stable in the acidic range of pH (4.0-5.5) for 30min, and thermostable within the temperature range 30-70°C. Using tannic acid, the enzyme had a Km value of 0.77mM and Vmax of 263.20μmolemin-1ml-1. The effect of different metal ions on enzymatic activity was evaluated. HPLC analysis data indicated that the purified enzyme could carry out 24.65% tannic acid conversion with 5.25 folds increase in gallic acid concentration within 30min only.

Improving the nutritive value of olive pomace by solid state fermentation of Kluyveromyces marxianus with simultaneous production of gallic acid

AbstractPurposeOlive oil industry is a growing industrial sector in Mediterranean countries. Unfortunately, about 30–35% of total olive weight is discarded as olive pomace (OP), a highly environmental-polluting solid waste. OP is mostly used for composting and production of animal feed; nevertheless, the high oil content, phenolic compounds and fiber contents in addition to its low protein content represent major obstacles for both applications. So, the present study was conducted to evaluate the role of solid state fermentation (SSF) in OP using Kluyveromyces marxianus NRRL Y-8281 yeast on the chemical composition and tannin content of OP in a trial for its bioconversion into a value-added animal feed.MethodsChemical composition, nutritive and energetic values, tannin and gallic acid contents of unfermented and fermented olive pomace were investigated.ResultsThe fermentation altered the chemical composition of OP, so that crude fiber was decreased by 8.56%, while crude protein, fat and carbohydrate contents were increased by 2.74, 2.63 and 3.57%, respectively. Moreover, the effect of fermentation on cell wall constituents, gross energy, digestible energy, total digestible nutrients and digestible crude protein was evaluated. Furthermore, HPLC analysis revealed that K. marxianus mediated fermentation of OP resulted in a sharp decrease in tannin content by 96.75% with 2.8 times increase in gallic acid concentration.ConclusionSSF of OP by K. marxianus does not only eliminate the environmental pollution resulting from its accumulation, but also presents a new eco-friendly valorization technique which leaves OP with an altered chemical composition allowing its use as animal feed or compost.