McKay RM et al. (2007) EMBO Rep "Tripeptidyl peptidase II promotes fat formation in a conserved fashion."

Suh JM, McKay JP, Avery L, McKay RM, Graff JM

[EMBO Rep, 2007]

Tripeptidyl peptidase II (TPPII) is a multifunctional and evolutionarily conserved protease. In the mammalian hypothalamus, TPPII has a proposed anti-satiety role affected by degradation of the satiety hormone cholecystokinin 8. Here, we show that TPPII also regulates the metabolic homoeostasis of Caenorhabditis elegans; TPPII RNA interference (RNAi) decreases worm fat stores. However, this occurs independently of feeding behaviour and seems to be a function within fat-storing tissues. In mammalian cell culture, TPPII stimulates adipogenesis and TPPII RNAi blocks adipogenesis. The pro-adipogenic action of TPPII seems to be independent of protease function, as catalytically inactive TPPII also increases adipogenesis. Mice that were homozygous for an insertion in the Tpp2 locus were embryonic lethal. However, Tpp2 heterozygous mutants were lean compared with wild-type littermates, although food intake was normal. These findings indicate that TPPII has central and peripheral roles in regulating metabolism and that TPPII actions in fat-storing tissues might be an ancient function carried out in a protease-independent manner.

McKay RM et al. (2003) Dev Cell "C elegans: a model for exploring the genetics of fat storage."

McKay RM, Graff JM, McKay JP, Avery L

[Dev Cell, 2003]

To gain insights into the genetic cascades that regulate fat biology, we evaluated C. elegans as an appropriate model organism. We generated worms that lack two transcription factors, SREBP and C/EBP, crucial for formation of mammalian fat. Worms deficient in either of these genes displayed a lipid-depleted phenotype-pale, skinny, larval-arrested worms that lack fat stores. On the basis of this phenotype, we used a reverse genetic screen to identify several additional genes that play a role in worm lipid storage. Two of the genes encode components of the mitochondrial respiratory chain (MRC). When the MRC was inhibited chemically in worms or in a mammalian adipocyte model, fat accumulation was markedly reduced. A third encodes lpd-3, whose homolog is also required for fat storage in a mammalian model. These data suggest that C. elegans is a genetically tractable model to study the mechanisms that underlie the biology of fat-storing

Ma C et al. (2015) Molecules "Potent Activities of Roemerine against Candida albicans and the Underlying Mechanisms."

Yan L, Xu G, Wang C, He G, Du F, Jiang Y, Ma C, Rao G, He J

[Molecules, 2015]

Roemerine (RM) is an aporphine alkaloid isolated from the fresh rattan stem of Fibraurea recisa, and it has been demonstrated to have certain antifungal activity. This study aimed to investigate the antifungal activity of RM and the underlying mechanisms in Candida albicans (C. albicans). The in vitro antifungal activity of RM was evaluated by a series of experiments, including the XTT reduction assay, confocal laser scanning microscopy assay, scanning electron microscope assay. Results showed that 1 g/mL RM inhibited biofilm formation significantly (p < 0.01) both in Spider medium and Lee's medium. In addition, RM could inhibit yeast-to-hyphae transition of C. albicans in a dose-dependent manner. The biofilm-specific and hypha-specific genes such as YWP1, SAP5, SAP6, HWP1, ECE1 were up-regulated and EFG1 was down-regulated after 8 g/mL RM treatment. Furthermore, the toxicity of RM was investigated using C. elegans worms, three cancer cells and one normal cell. The date showed that RM had no significant toxicity. In conclusion, RM could inhibited the formation of C. albicans biofilm in vitro, but it had no fungicidal effect on planktonic C. albicans cells, and the anti-biofilm mechanism may be related to the cAMP pathway.

Gouveia GJ et al. (2021) Anal Chem "Long-Term Metabolomics Reference Material."

Andersen EC, Morse AM, Garcia BM, Edison AS, Shaver AO, Gouveia GJ, McIntyre LM

[Anal Chem, 2021]

The use of quality control samples in metabolomics ensures data quality, reproducibility, and comparability between studies, analytical platforms, and laboratories. Long-term, stable, and sustainable reference materials (RMs) are a critical component of the quality assurance/quality control (QA/QC) system; however, the limited selection of currently available matrix-matched RMs reduces their applicability for widespread use. To produce an RM in any context, for any matrix that is robust to changes over the course of time, we developed iterative batch averaging method (IBAT). To illustrate this method, we generated 11 independently grown <i>Escherichia coli</i> batches and made an RM over the course of 10 IBAT iterations. We measured the variance of these materials by nuclear magnetic resonance (NMR) and showed that IBAT produces a stable and sustainable RM over time. This <i>E. coli</i> RM was then used as a food source to produce a <i>Caenorhabditis elegans</i> RM for a metabolomics experiment. The metabolite extraction of this material, alongside 41 independently grown individual <i>C. elegans</i> samples of the same genotype, allowed us to estimate the proportion of sample variation in preanalytical steps. From the NMR data, we found that 40% of the metabolite variance is due to the metabolite extraction process and analysis and 60% is due to sample-to-sample variance. The availability of RMs in untargeted metabolomics is one of the predominant needs of the metabolomics community that reach beyond quality control practices. IBAT addresses this need by facilitating the production of biologically relevant RMs and increasing their widespread use.

Lawal TA et al. (2020) Orphanet J Rare Dis "Preclinical model systems of ryanodine receptor 1-related myopathies and malignant hyperthermia: a comprehensive scoping review of works published 1990-2019."

Dowling JJ, Terry NL, Todd JJ, Wires ES, Lawal TA

[Orphanet J Rare Dis, 2020]

BACKGROUND: Pathogenic variations in the gene encoding the skeletal muscle ryanodine receptor (RyR1) are associated with malignant hyperthermia (MH) susceptibility, a life-threatening hypermetabolic condition and RYR1-related myopathies (RYR1-RM), a spectrum of rare neuromuscular disorders. In RYR1-RM, intracellular calcium dysregulation, post-translational modifications, and decreased protein expression lead to a heterogenous clinical presentation including proximal muscle weakness, contractures, scoliosis, respiratory insufficiency, and ophthalmoplegia. Preclinical model systems of RYR1-RM and MH have been developed to better understand underlying pathomechanisms and test potential therapeutics. METHODS: We conducted a comprehensive scoping review of scientific literature pertaining to RYR1-RM and MH preclinical model systems in accordance with the PRISMA Scoping Reviews Checklist and the framework proposed by Arksey and O'Malley. Two major electronic databases (PubMed and EMBASE) were searched without language restriction for articles and abstracts published between January 1, 1990 and July 3, 2019. RESULTS: Our search yielded 5049 publications from which 262 were included in this review. A majority of variants tested in RYR1 preclinical models were localized to established MH/central core disease (MH/CCD) hot spots. A total of 250 unique RYR1 variations were reported in human/rodent/porcine models with 95% being missense substitutions. The most frequently reported RYR1 variant was R614C/R615C (human/porcine total n=39), followed by Y523S/Y524S (rabbit/mouse total n=30), I4898T/I4897T/I4895T (human/rabbit/mouse total n=20), and R163C/R165C (human/mouse total n=18). The dyspedic mouse was utilized by 47% of publications in the rodent category and its RyR1-null (1B5) myotubes were transfected in 23% of publications in the cellular model category. In studies of transfected HEK-293 cells, 57% of RYR1 variations affected the RyR1 channel and activation core domain. A total of 15 RYR1 mutant mouse strains were identified of which ten were heterozygous, three were compound heterozygous, and a further two were knockout. Porcine, avian, zebrafish, C. elegans, canine, equine, and drosophila model systems were also reported. CONCLUSIONS: Over the past 30years, there were 262 publications on MH and RYR1-RM preclinical model systems featuring more than 200 unique RYR1 variations tested in a broad range of species. Findings from these studies have set the foundation for therapeutic development for MH and RYR1-RM.

Peters JM et al. (1999) Nature "Casein kinase I transduces Wnt signals."

McKay RM, Peters JM, Graff JM, McKay JP

[Nature, 1999]

The Wnt signalling cascade is essential for the development of both invertebrates and vertebrates, and is altered during tumorigenesis. Although a general framework for Wnt signalling has been elucidated, not all of the components have been identified. Here we describe a serine kinase, casein kinase I (CKI), which was isolated by expression cloning in Xenopus embryos. CKI reproduces several properties of Wnt signals, including generation of complete dorsal axes, stabilization of beta-catenin and induction of genes that are direct targets of Wnt signals. Dominant-negative forms of CKI and a pharmacological blocker of CKI inhibited Wnt signals in Xenopus. Inhibiting CKI in Caenorhabditis elegans generated worms with a mom phenotype, indicative of a loss of Wnt signals. In addition, CKI bound to and increased the phosphorylation of dishevelled, a known component of the Wnt pathway. These data indicate that CKI may be a conserved component of the Wnt pathway.

Volpatti JR et al. (2020) Elife "Identification of drug modifiers for RYR1 related myopathy using a multi-species discovery pipeline."

Groom L, Endo Y, Volpatti JR, Zuercher WJ, Brennan S, Roy P, Dirksen RT, Dowling JJ, Knox J, Noche R

[Elife, 2020]

Ryanodine receptor type I-related myopathies (RYR1-RMs) are a common group of childhood muscle diseases associated with severe disabilities and early mortality for which there are no available treatments. The goal of this study is to identify new therapeutic targets for RYR1-RMs. To accomplish this, we developed a discovery pipeline using nematode, zebrafish, and mammalian cell models. We first performed large-scale drug screens in <i>C. elegans</i> which uncovered 74 hits. Targeted testing in zebrafish yielded positive results for two p38 inhibitors. Using mouse myotubes, we found that either pharmacological inhibition or siRNA silencing of p38 impaired caffeine-induced Ca²⁺ release from wild type cells while promoting intracellular Ca²⁺ release in <i>Ryr1</i> knockout cells. Lastly, we demonstrated that p38 inhibition blunts the aberrant temperature-dependent increase in resting Ca²⁺ in myotubes from an RYR1-RM mouse model. This unique platform for RYR1-RM therapy development is potentially applicable to a broad range of neuromuscular disorders.

Yu Z et al. (2011) J Environ Sci (China) "Behavior toxicity to Caenorhabditis elegans transferred to the progeny after exposure to sulfamethoxazole at environmentally relevant concentrations."

Yu Z, Jiang L, Yin D

[J Environ Sci (China), 2011]

Sulfamethoxazole (SMX) is one of the most common detected antibiotics in the environment. In order to study whether SMX can affect behavior and growth and whether these effects could be transferred to the progeny, Caenorhabditis elegans was exposed at environmentally relevant concentrations for 24, 48, 72 and 96 hr, respectively. After exposure, the exposed parent generation (P0) was measured for behavior and growth indicators, which were presented as percentage of controls (POC). Then their corresponding unexposed progeny (F1) was separated and measured for the same indicators. The lowest POC for P0 after 96 hr-exposure at 100 mg/L were 37.8%, 12.7%, 45.8% and 70.1% for body bending frequency (BBF), reversal movement (RM), Omega turns (OT) and body length (BL), respectively. And F1 suffered defects with the lowest POC as 55.8%, 24.1%, 48.5% and 60.7% for BBF, RM, OT and BL, respectively. Defects in both P0 and F1 showed a time- and concentration-dependent fashion and behavior indicators showed better sensitivity than growth indicator. The observed effects on F1 demonstrated the transferable properties of SMX. Defects of SMX at environmental concentrations suggested that it is necessary to perform further systematical studies on its ecological risk in actual conditions.

Zaridah MZ et al. (2001) J Ethnopharmacol "In vitro antifilarial effects of three plant species against adult worms of subperiodic Brugia malayi."

Omar AW, Idid SZ, Zaridah MZ, Khozirah S

[J Ethnopharmacol, 2001]

Five aqueous extracts from three plant species, i.e., dried husks (HX), dried seeds (SX) and dried leaves (LX) of Xylocarpus granatum (Meliaceae), dried stems (ST) of Tinospora crispa (Menispermaceae) and dried leaves (LA) of Andrographis paniculata (Acanthaceae) were tested in vitro against adult worms of subperiodic Brugia malayi. The relative movability (RM) value of the adult worms over the 24-h observation period was used as a measure of the antifilarial activity of the aqueous extracts. SX extract of X. granatum demonstrated the strongest activity, followed by the LA extract of A. paniculata, ST extract of T. crispa, HX extract and LX extract of X. granatum.

Zhou, Y et al. (2017) International Worm Meeting "Genetic and chemical modulation of C. elegans intestinal antiviral innate immunity."

Zhou, Y, Tao, Y, Bedian, L, Zhong, W

[International Worm Meeting, 2017]

The RNA virus Orsay is the only known natural viral pathogen infecting the intestine cells of the nematode C. elegans. The C. elegans intestine cells resemble human intestinal epithelial cells not only in morphological features such as microvilli, but also in molecular mechanisms such as antibacterial innate immune response. As Orsay was discovered only six years ago, the C. elegans antiviral innate immune system remains largely unknown. Only two pathways, RNAi and ubiquitin-mediated protein degradation, have been discovered to be involved in the C. elegans antiviral innate immunity. To explore the genetic landscape of the C. elegans antiviral innate immunity, we conducted a genome-wide RNAi screen for genes whose inactivation sensitizes worms to Orsay infection. 110 genes were identified to be required for C. elegans antiviral innate immunity. 72 of these genes have human orthologs. Tissue-specific RNAi experiments showed that the majority of these genes function in the intestine cells to modulate antiviral innate immunity. In addition to RNAi and ubiquitin-mediated protein degradation, these genes encompass pathways in autophagy, mitochondrial unfolded protein responses, collagens, cytoskeletal organization, RNA processing, and transcription. To identify the gene products that are druggable, we screened 2000 chemicals for drugs that can alleviate Orsay infection symptoms, and discovered four innate immunity enhancing drugs, resorcinol monoacetate (RM), berberine (BBR), bismuth subsalicylate, 3,3'- diindolymethane (DIM). BBR and bismuth subsalicylate are known antidiarrhea drugs, with possible antiviral functions against human gastrointestinal viruses. Chemical-genetic experiments revealed that these drugs have different mechanism of actions: RM strengthens the collagen barrier for viral entry; BBR and DIM enhances the ubiquitin-mediated protein degradation pathway. Together, these data revealed a multifaceted antiviral innate immune system in the C. elegans intestine. Aspects of genetic and chemical modulation of this system may be conserved in human innate immunity against gastrointestinal viruses.