A target repurposing approach identifies N-myristoyltransferase as a new candidate drug target in filarial nematodes

Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5-10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis

Weak selection and stability of localized distributions in Ostwald ripening

We support and generalize a weak selection rule predicted recently for the self-similar asymptotics of the distribution function (DF) in the zero-volume-fraction limit of Ostwald ripening (OR). An asymptotic perturbation theory is developed that, when combined with an exact invariance property of the system, yields the selection rule, predicts a power-law convergence towards the selected self-similar DF and agrees well with our numerical simulations for the interface- and diffusion-controlled OR.Comment: 4 pages, 2 figures, submitted to PR

Comparison of Costs, Re-Intervention Rates, and Length of Hospital Stay for Three Uterus Sparing Interventions for Uterine Fibroids: A 2-Year Retrospective Claims Analysis

David Eisenstein,1 Ghadear H Shukr,2 John J Carlow,3 Laura Kemp,4 Steve Yu5 1Department of Urology, Trinity/IHA Medical Group, Detroit, MI, USA; 2Department of Obstetrics and Gynecology, University of South Florida Morsani College of Medicine, Tampa Bay, FL, USA; 3Discovery Statistics, Laguna Niguel, CA, USA; 4Kemp Clinical Consulting Co LLC, Carlsbad, CA, USA; 5Department of Urology, Hoag Hospital, Newport Beach, CA, USACorrespondence: John J Carlow, Discovery Statistics, 31434 West Nine Drive, Laguna Niguel, CA, 92677, USA, Tel/Fax +1 760-519-7395, Email [email protected]: To describe two-year post-operative outcomes, and healthcare utilization of three uterus-sparing interventions used to treat women with intramural and/or subserosal uterine fibroids.Subjects and Methods: This was a post-market, randomized, prospective, multi-center, longitudinal, interventional, and comparative clinical study to evaluate the costs and health outcomes of LAP-RFA vs the standard uterine conserving technologies (myomectomy and UAE) for the treatment of symptomatic uterine fibroids in women who desire uterine conservation. For this RCT study, 54 subjects were randomized on a 1:1 ratio across the three procedures and followed out to two years. Their results were compared to retrospective US insurance claims from the IBM MarketScan® Commercial Database from 2017– 2020 for 96,854 women who underwent a uterus-sparing procedure for fibroids.Results: Mean ambulatory surgical center costs and the mean out-patient hospital costs were lowest for LAP-RFA ($13,134 and $14,428) and highest for UAE ($28,214 and $19,131). The total two-year re-intervention rate of any subsequent procedure (AM, LM, LAP-RFA, or UAE) was lowest in AM group (0%) followed by LM (4.2%), LAP-RFA (11%), and UAE (33%). Mean peri-operative reintervention costs and the mean reintervention total costs were $2429 and $5939 for LAP-RFA, $2122 and $8368 for LM, $4410 and $11,942 for AM, and $8113 and $46,692 for UAE subjects. In the RCT study, the average length of hospital stay was significantly less for the LAP-RFA group subjects (8.2 hours) in contrast to both the laparoscopic myomectomy group subjects (16.0 hours) and the abdominal myomectomy group subjects (33.6 hours). Despite the small numbers, two-year reintervention rates followed a similar pattern as the IBM MarketScan data.Conclusion: In comparing these three non-invasive approaches, LAP-RFA was associated with the lowest peri-operative cost, and UAE was associated with the highest peri-operative cost. Further studies are needed to assess the cost, effectiveness, and subject satisfaction with each procedure.Keywords: health economics, leiomyomas, interventional, cost/burde

Genomes of the human filarial parasites Mansonella perstans and Mansonella ozzardi

Funding Information: Research funding was provided by New England Biolabs, Ipswich, MA 01938, USA to AS, ZL, LE, RM, CP, CC. FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) supported the field research in Brazil through a research grant to M.U.F (2013/12723-7) and a doctoral scholarship to NL (2013/26928-0). Acknowledgments Funding Information: Research funding was provided by New England Biolabs, Ipswich, MA 01938, USA to AS, ZL, LE, RM, CP, CC. FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) supported the field research in Brazil through a research grant to M.U.F (2013/12723-7) and a doctoral scholarship to NL (2013/26928-0). Publisher Copyright: Copyright © 2023 Sinha, Li, Poole, Morgan, Ettwiller, Lima, Ferreira, Fombad, Wanji and Carlow.The filarial parasites Mansonella ozzardi and Mansonella perstans, causative agents of mansonellosis, infect hundreds of millions of people worldwide, yet remain among the most understudied of the human filarial pathogens. M. ozzardi is highly prevalent in Latin American countries and Caribbean Islands, while M. perstans is predominantly found in sub-Saharan Africa as well as in a few areas in South America. In addition to the differences in their geographical distribution, the two parasites are transmitted by different insect vectors, as well as exhibit differences in their responses to commonly used anthelminthic drugs. The lack of genome information has hindered investigations into the biology and evolution of Mansonella parasites and understanding the molecular basis of the clinical differences between species. In the current study, high quality genomes of two independent clinical isolates of M. perstans from Cameroon and two M. ozzardi isolates one from Brazil and one from Venezuela are reported. The genomes are approximately 76 Mb in size, encode about 10,000 genes each, and are largely complete based on BUSCO scores of about 90%, similar to other completed filarial genomes. These sequences represent the first genomes from Mansonella parasites and enabled a comparative genomic analysis of the similarities and differences between Mansonella and other filarial parasites. Horizontal DNA transfers (HDT) from mitochondria (nuMTs) as well as transfers from genomes of endosymbiotic Wolbachia bacteria (nuWTs) to the host nuclear genome were identified and analyzed. Sequence comparisons and phylogenetic analysis of known targets of anti-filarial drugs diethylcarbamazine (DEC), ivermectin and mebendazole revealed that all known target genes were present in both species, except for the DEC target encoded by gon-2 gene, which is fragmented in genome assemblies from both M. ozzardi isolates. These new reference genome sequences will provide a valuable resource for further studies on biology, symbiosis, evolution and drug discovery.publishersversionpublishe

Cappable-Seq reveals the transcriptional landscape of stress responses in the bacterial endosymbiont <i>Wolbachia</i>.

Bacterial endosymbionts are highly prevalent among invertebrate animals, in which they can confer fitness benefits such as pathogen defence and/or act as reproductive manipulators, inducing phenotypes including cytoplasmic incompatibility (CI). For the alpha-proteobacterium Wolbachia, its wide distribution among macroparasites and disease-transmitting arthropods coupled with mutualistic roles, reduction of vector competence and CI has found recent applications in the control of several vector-borne tropical diseases. However, in common with other bacterial endosymbionts, which often lose regulatory elements during genomic erosion, the degree to which Wolbachia can respond to environmental or pharmacological stressors is poorly understood. Here, we apply Cappable-Seq methodology to achieve unprecedented depth and resolution of transcriptional start sites (TSS) in two Wolbachia strains (wMelPop-CLA and wAlbB) that have been used to transinfect mosquitoes for arbovirus control. We exposed Wolbachia in mosquito cell lines to temperature stress (both strains) or antibiotics (wAlbB only) and observed that all classes of TSS (including antisense) exhibited differential regulation, some of which were associated with mobile elements and may control ncRNA expression. Of the three antibiotics used as pharmacological stressors (doxycycline, rifampicin and moxifloxacin), doxycycline had the greatest impact on differential expression from primary TSS. Cappable-Seq also resolved the organization of the bicistronic cifA/cifB operon that is responsible for inducing CI in Wolbachia hosts. The use of Cappable-Seq in this study enabled the resolution of the primary transcriptome of an obligate intracellular bacterium in unparalleled detail. Moreover, this methodology shows great promise for revealing regulation of symbiont functions in whole invertebrates

Rural+:The plain, the beautiful, the sustainable in rural housing

This paper explores the role of landscape aesthetics and sustainability in the development of new rural housing prototypes. Historically, rural building forms were largely influenced by immediately available materials, climate and specific use, resulting in regionally identifiable typologies. Changes in the way we live, proximity to place of work, and the relationship between home, community and land-use have resulted in rural domestic buildings losing specific regional distinctions. The aim of this research is to generate new spatial models of autarkic housing and alternative massing arrangements that respond to local landscape qualities, hybrid land-use, urban densities and local renewable energy production. The outcomes provide, semi-quantifiable spatial development prototypes that integrate these requirements within holistic conceptual frameworks for rural sustainable living providing alternative approaches to addressing Scottish policy legislation and a primer for further research

Phosphorylation of Mouse Immunity-Related GTPase (IRG) Resistance Proteins Is an Evasion Strategy for Virulent Toxoplasma gondii

GTPases of the mouse IRG protein family, mediators of resistance against Toxoplasma gondii in the mouse, are inactivated by a polymorphic kinase of the parasite, resulting in enhanced parasite virulence

Strongyloides stercoralis age-1: A Potential Regulator of Infective Larval Development in a Parasitic Nematode

Infective third-stage larvae (L3i) of the human parasite Strongyloides stercoralis share many morphological, developmental, and behavioral attributes with Caenorhabditis elegans dauer larvae. The ‘dauer hypothesis’ predicts that the same molecular genetic mechanisms control both dauer larval development in C. elegans and L3i morphogenesis in S. stercoralis. In C. elegans, the phosphatidylinositol-3 (PI3) kinase catalytic subunit AGE-1 functions in the insulin/IGF-1 signaling (IIS) pathway to regulate formation of dauer larvae. Here we identify and characterize Ss-age-1, the S. stercoralis homolog of the gene encoding C. elegans AGE-1. Our analysis of the Ss-age-1 genomic region revealed three exons encoding a predicted protein of 1,209 amino acids, which clustered with C. elegans AGE-1 in phylogenetic analysis. We examined temporal patterns of expression in the S. stercoralis life cycle by reverse transcription quantitative PCR and observed low levels of Ss-age-1 transcripts in all stages. To compare anatomical patterns of expression between the two species, we used Ss-age-1 or Ce-age-1 promoter::enhanced green fluorescent protein reporter constructs expressed in transgenic animals for each species. We observed conservation of expression in amphidial neurons, which play a critical role in developmental regulation of both dauer larvae and L3i. Application of the PI3 kinase inhibitor LY294002 suppressed L3i in vitro activation in a dose-dependent fashion, with 100 µM resulting in a 90% decrease (odds ratio: 0.10, 95% confidence interval: 0.08–0.13) in the odds of resumption of feeding for treated L3i in comparison to the control. Together, these data support the hypothesis that Ss-age-1 regulates the development of S. stercoralis L3i via an IIS pathway in a manner similar to that observed in C. elegans dauer larvae. Understanding the mechanisms by which infective larvae are formed and activated may lead to novel control measures and treatments for strongyloidiasis and other soil-transmitted helminthiases

A Family of Diverse Kunitz Inhibitors from Echinococcus granulosus Potentially Involved in Host-Parasite Cross-Talk

The cestode Echinococcus granulosus, the agent of hydatidosis/echinococcosis, is remarkably well adapted to its definitive host. However, the molecular mechanisms underlying the successful establishment of larval worms (protoscoleces) in the dog duodenum are unknown. With the aim of identifying molecules participating in the E. granulosus-dog cross-talk, we surveyed the transcriptomes of protoscoleces and protoscoleces treated with pepsin at pH 2. This analysis identified a multigene family of secreted monodomain Kunitz proteins associated mostly with pepsin/H+-treated worms, suggesting that they play a role at the onset of infection. We present the relevant molecular features of eight members of the E. granulosus Kunitz family (EgKU-1 – EgKU-8). Although diverse, the family includes three pairs of close paralogs (EgKU-1/EgKU-4; EgKU-3/EgKU-8; EgKU-6/EgKU-7), which would be the products of recent gene duplications. In addition, we describe the purification of EgKU-1 and EgKU-8 from larval worms, and provide data indicating that some members of the family (notably, EgKU-3 and EgKU-8) are secreted by protoscoleces. Detailed kinetic studies with native EgKU-1 and EgKU-8 highlighted their functional diversity. Like most monodomain Kunitz proteins, EgKU-8 behaved as a slow, tight-binding inhibitor of serine proteases, with global inhibition constants (KI*) versus trypsins in the picomolar range. In sharp contrast, EgKU-1 did not inhibit any of the assayed peptidases. Interestingly, molecular modeling revealed structural elements associated with activity in Kunitz cation-channel blockers. We propose that this family of inhibitors has the potential to act at the E. granulosus-dog interface and interfere with host physiological processes at the initial stages of infection