Gene Expression Signatures in AML-12 Hepatocyte Cells upon Dengue virus Infection and Acetaminophen Treatment.

Dengue is an acute viral disease caused by Dengue virus (DENV) and is considered to be the most common arbovirus worldwide. The clinical characteristics of dengue may vary from asymptomatic to severe complications and severe organ impairment, particularly affecting the liver. Dengue treatment is palliative with acetaminophen (APAP), usually known as Paracetamol, being the most used drug aiming to relieve the mild symptoms of dengue. APAP is a safe and effective drug but, like dengue, can trigger the development of liver disorders. Given this scenario, it is necessary to investigate the effects of combining these two factors on hepatocyte homeostasis. Therefore, this study aimed to evaluate the molecular changes in hepatocytes resulting from the association between DENV infection and treatment with sub-toxic APAP concentrations. Using an in vitro experimental model of DENV-2 infected hepatocytes (AML-12 cells) treated with APAP, we evaluated the influence of the virus and drug association on the transcriptome of these hepatocytes by RNA sequencing (RNAseq). The virus-drug association was able to induce changes in the gene expression profile of AML-12 cells and here we highlight and explore these changes and its putative influence on biological processes for cellular homeostasis.

Comparative transcriptome analyses of magainin I-susceptible and -resistant Escherichia coli strains.

Antimicrobial peptides (AMPs) have attracted considerable attention because of their multiple and complex mechanisms of action toward resistant bacteria. However, reports have increasingly highlighted how bacteria can escape AMP administration. Here, the molecular mechanisms involved in Escherichia coli resistance to magainin I were investigated through comparative transcriptomics. Sub-inhibitory concentrations of magainin I were used to generate four experimental groups, including magainin I-susceptible E. coli, in the absence (C) and presence of magainin I (CM); and magainin I-resistant E. coli in the absence (R) and presence of magainin I (RM). The total RNA from each sample was extracted; cDNA libraries were constructed and further submitted for Illumina MiSeq sequencing. After RNA-seq data pre-processing and functional annotation, a total of 103 differentially expressed genes (DEGs) were identified, mainly related to bacterial metabolism. Moreover, down-regulation of cell motility and chaperone-related genes was observed in CM and RM, whereas cell communication, acid tolerance and multidrug efflux pump genes (ABC transporter, major facilitator and resistance-nodulation cell division superfamilies) were up-regulated in these same groups. DEGs from the C and R groups are related to basal levels of expression of homeostasis-related genes compared to CM and RM, suggesting that the presence of magainin I is required to change the transcriptomics panel in both C and R E. coli strains. These findings show the complexity of E. coli resistance to magainin I through the rearrangement of several metabolic pathways involved in bacterial physiology and drug response, also providing information on the development of novel antimicrobial strategies targeting resistance-related transcripts and proteins herein described.

Insights into novel antimicrobial compounds and antibiotic resistance genes from soil metagenomes.

In recent years a major worldwide problem has arisen with regard to infectious diseases caused by resistant bacteria. Resistant pathogens are related to high mortality and also to enormous healthcare costs. In this field, cultured microorganisms have been commonly focused in attempts to isolate antibiotic resistance genes or to identify antimicrobial compounds. Although this strategy has been successful in many cases, most of the microbial diversity and related antimicrobial molecules have been completely lost. As an alternative, metagenomics has been used as a reliable approach to reveal the prospective reservoir of antimicrobial compounds and antibiotic resistance genes in the uncultured microbial community that inhabits a number of environments. In this context, this review will focus on resistance genes as well as on novel antibiotics revealed by a metagenomics approach from the soil environment. Biotechnology prospects are also discussed, opening new frontiers for antibiotic development.