Profiling the macrofilaricidal effects of flubendazole on adult female Brugia malayi using RNAseq

Abstract

The use of microfilaricidal drugs for the control of onchocerciasis and lymphatic filariasis (LF) necessitates prolonged yearly dosing. Prospects for elimination or eradication of these diseases would be enhanced by the availability of a macrofilaricidal drug. Flubendazole (FLBZ), a benzimidazole anthelmintic, is an appealing candidate. FLBZ has demonstrated potent macrofilaricidal effects in a number of experimental rodent models and in one human trial. Unfortunately, FLBZ was deemed unsatisfactory for use in mass drug administration campaigns due to its limited oral bioavailability. A new formulation that enables sufficient bioavailability following oral administration could render FLBZ an effective treatment for onchocerciasis and LF. Identification of drug-derived effects is important in ascertaining a dosage regimen which is predicted to be lethal to the parasite in situ. In previous histological studies, exposure to FLBZ induced damage to tissues required for reproduction and survival at pharmacologically relevant concentrations. However, more precise and quantitative indices of drug effects are needed. This study assessed drug effects using a transcriptomic approach to confirm effects observed histologically and to identify genes which were differentially expressed in treated adult female Brugia malayi. Comparative analysis across different concentrations (1 μM and 5 μM) and durations (48 and 120 h) provided an overview of the processes which are affected by FLBZ exposure. Genes with dysregulated expression were consistent with the reproductive effects observed via histology in our previous studies. This study revealed transcriptional changes in genes involved in embryo development. Additionally, significant downregulation was observed in genes encoding cuticle components, which may reflect changes in developing embryos, the adult worm cuticle or both. These data support the hypothesis that FLBZ acts predominantly on rapidly dividing cells, and provides a basis for selecting molecular markers of drug-induced damage which may be of use in predicting efficacious FLBZ regimens.

RNA-Seq de novo assembly and differential transcriptome analysis of the nematode Ascaridia galli in relation to in vivo exposure to flubendazole

“…However, no differences were found when we compared the gene expression levels of different beta-tubulin isotypes from treated and untreated worms. This has been observed previously in the filaroid nematode Brugia malayi after FLBZ exposure [ 53 ]. Although it has been shown that certain mutations are implicated in BZ resistance in strongylid nematodes [ 21 , 22 , 52 ], further investigation is required to confirm whether a similar mechanism is involved in the drug binding and selection for AR in ascarids, including A .…”

Human Migration and the Spread of the Nematode ParasiteWuchereria bancrofti

“…D-dopachrome tautomerase (DDT) as a co-factor of macrophage inhibitory factor (MIF-1) [Merk et al, 2011] and reproductive timing, nurf-1 [Large et al, 2016]. We also identified signals consistent with local adaptation at a GABA transporter previously noted as being upregulated in studies of the anthelmintic flubendazole [Jiang et al, 2005, Mullen et al, 2006, Casida and Durkin, 2013, O'Neill et al, 2016. Only two regions, with a single known gene annotation, were consistent with adaptation in the Kenyan Wb population: the SLO-1 gene is a calcium-activated potassium channel [Welz et al, 2011].…”

“…Four of the outlier genes have also been identified as potential targets for new anti-parasite drugs in the Malian and Kenyan populations of Wb: Na/Cl GABA transporter [Jiang et al, 2005, Mullen et al, 2006, Casida and Durkin, 2013, O'Neill et al, 2016, PAN domain protein [Kumar et al, 2007, O'Neill et al, 2016, SLO-1 Ca-activated K channel [Welz et al, 2011], phosphatidate cytidylyltransferase [Narayan et al, 1989, Crowther et al, 2010 (table 2). All of our samples were collected prior to mass drug administration; thus, the signal of local adaptation may be in response to other environmental factors rather than widespread drug resistance.…”

The anthelmintic drug flubendazole induces cell apoptosis and inhibits NF-κB signaling in esophageal squamous cell carcinoma

“…Our study showed that, similar to IKK inhibitors, flubendazole also suppressed NF-κB p65 phosphorylation by inhibiting IKK activation (Figure 4). Although several different mechanisms, such as specifically binding to tubulin,31 dysregulating cuticle-associated genes’ expression,32 and oxidative damage,33 have been reported for the anthelmintic action of flubendazole, it is still not clear how flubendazole affects IKK activation.…”