Zahreddine Fahs, Hala et al. (2021) International Worm Meeting "Multi-species nematode screening uncovers a new broad-spectrum class of anthelmintic compounds targeting mitochondrial lipid metabolism"

Gopinadhan, Suma, Refai, Fathima, White, Robert, Pearson, Yanthe, Kremb, Stephan, Butterfoss, Glenn, Gunsalus, Kristin C., Zahreddine Fahs, Hala, Xie, Xin, Cipriani, Patricia, Page, Anthony, Piano, Fabio

[International Worm Meeting, 2021]

Parasitic worms infect more than 1.5 billion people and cause significant losses in livestock and crops. New anthelmintic drugs are urgently needed, as resistance to the existing drugs is emerging. We built a high-throughput (HTP) and high-content robotic screening platform to identify bioactive small molecules and their molecular targets, focusing on novel disease therapeutics and broad spectrum anthelmintics. The platform is capable of screening compound collections and genetic libraries in model organisms and mammalian cells in a fully integrated manner. To find novel anthelmintics we screened a ~2300 compound library containing most of the FDA-approved approved drugs, plus natural products and bioactive compounds for broad spectrum toxic effects on two distantly related free living nematodes C. elegans and P. pacificus as model animals while having low toxicity on human cell lines. The screen confirmed the effects of most known anthelmintics on these nematode models. Additionally, among a set of new compounds, we found six natural lipid molecules that exhibit broad-spectrum anthelmintic activity. These novel compounds kill C. elegans and P. pacificus when applied at various developmental stages, including the dauer and embryonic stages, in a dose-dependent manner. Importantly, these compounds cause mortality in all three veterinary parasite species we tested: the hookworm Haemonchus contortus (ruminants), Teladorsagia circumcincta (sheep and goat) and Heligmosomoides polygyrus (rodents). Further characterization of their mode of action using C. elegans revealed defects associated with mitochondrial function and lipid metabolism. The lethality phenotype in C. elegans is partially rescued by knocking down the enzymes acs-2, cpt-4, dif-1 and cpt-2, which facilitates mitochondrial lipid transfer, while drug inhibitors of CPT1 and CPT2 enhance the phenotype, suggesting that these compounds perturb specifically fatty acid oxidation in nematodes. These compounds constitute a new class of broad-spectrum anthelmintics targeting lipid metabolism.

Cipriani, Patricia Giselle et al. (2021) International Worm Meeting "LOTUS-domain containing proteins recruit C. elegans Vasa to germline granules and control the formation and size of the condensates"

Gan, Hin Hark, Fahs, Hala, Chung, George, Gunsalus, Kristin, Chen, Jiaxuan, Zinno, John, Duchaine, Thomas, Selbach, Matthias, Piano, Fabio, Mayya, Vinay, Gutwein, Michelle, Cipriani, Patricia Giselle, Bay, Olivia

[International Worm Meeting, 2021]

Limkain, Oskar and TUDOR 5 and 7 are LOTUS-domain containing proteins that have been described as important regulators of germline development and nucleators of ribonucleoprotein complexes in the germ cells of many metazoans. LOTUS-domain proteins have not been previously described in the C. elegans germ line. MIP-1 and MIP-2 are two previously uncharacterized paralogs that contain two LOTUS domains and extensive intrinsically disordered regions. Using co-immunoprecipitation, we found these proteins to be strong interactors of MEG-3, another intrinsically disordered protein that is a core component of embryonic P granules, and we named them MEG-3 Interacting Proteins 1 and 2. Fluorescently tagged and deletion alleles of the MIPs generated by CRIPSR-Cas9 show that the MIPs are constitutive components of germline granules in both embryos and the germ line. The simultaneous depletion of MIPs produces temperature sensitive sterility, a strong mortal germ line phenotype, and defects that affect all major developmental switches in germline development, including germline stem cell maintenance, the progression of cells through meiosis, and gametogenesis. The MIPs are jointly required for the condensation of other core P granule components, including MEG-3, the C. elegans Vasa homolog GLH-1, and PGL proteins. Interestingly, loss of function of either MIP individually affects the distribution and the size of remaining granules in the germ line in complementary ways. In oocytes, mip-1 deletion produces larger granules that are mostly cytoplasmic and mip-2 deletion produces smaller granules mostly attached to the nuclear membrane. Further biochemical and yeast-two hybrid analyses have shown that the MIPs physically interact with each other by forming homo- and heterodimers, and they directly bind GLH-1 through their N-terminal region, which contains the LOTUS domains. We propose that these proteins act as organizing centers in ribonucleoprotein networks and form a scaffold that helps recruit and balance essential RNA processing machinery within germline granules to regulate key developmental transitions in the germline.