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A metabolic regulon reveals early and late acting enzymes in neuroactive Lycopodium alkaloid biosynthesis

Nett RS, Dho Y, Low YY, Sattely ES

Proc Natl Acad Sci U S A, 2021 06 15;118(24).
PMID: 34112718 DOI: 10.1073/pnas.2102949118

Plants synthesize many diverse small molecules that affect function of the mammalian central nervous system, making them crucial sources of therapeutics for neurological disorders. A notable portion of neuroactive phytochemicals are lysine-derived alkaloids, but the mechanisms by which plants produce these compounds have remained largely unexplored. To better understand how plants synthesize these metabolites, we focused on biosynthesis of the Lycopodium alkaloids that are produced by club mosses, a clade of plants used traditionally as herbal medicines. Hundreds of Lycopodium alkaloids have been described, including huperzine A (HupA), an acetylcholine esterase inhibitor that has generated interest as a treatment for the symptoms of Alzheimer's disease. Through combined metabolomic profiling and transcriptomics, we have identified a developmentally controlled set of biosynthetic genes, or potential regulon, for the Lycopodium alkaloids. The discovery of this putative regulon facilitated the biosynthetic reconstitution and functional characterization of six enzymes that act in the initiation and conclusion of HupA biosynthesis. This includes a type III polyketide synthase that catalyzes a crucial imine-polyketide condensation, as well as three Fe(II)/2-oxoglutarate-dependent dioxygenase (2OGD) enzymes that catalyze transformations (pyridone ring-forming desaturation, piperidine ring cleavage, and redox-neutral isomerization) within downstream HupA biosynthesis. Our results expand the diversity of known chemical transformations catalyzed by 2OGDs and provide mechanistic insight into the function of noncanonical type III PKS enzymes that generate plant alkaloid scaffolds. These data offer insight into the chemical logic of Lys-derived alkaloid biosynthesis and demonstrate the tightly coordinated coexpression of secondary metabolic genes for the biosynthesis of medicinal alkaloids.
Fulltext Plant carbonic anhydrase-like enzymes in neuroactive alkaloid biosynthesis

Nett RS, Dho Y, Tsai C, Passow D, Martinez Grundman J, Low YY, et al.

Nature, 2023 Dec;624(7990):182-191.
PMID: 37938780 DOI: 10.1038/s41586-023-06716-y

Plants synthesize numerous alkaloids that mimic animal neurotransmitters1. The diversity of alkaloid structures is achieved through the generation and tailoring of unique carbon scaffolds2,3, yet many neuroactive alkaloids belong to a scaffold class for which no biosynthetic route or enzyme catalyst is known. By studying highly coordinated, tissue-specific gene expression in plants that produce neuroactive Lycopodium alkaloids4, we identified an unexpected enzyme class for alkaloid biosynthesis: neofunctionalized α-carbonic anhydrases (CAHs). We show that three CAH-like (CAL) proteins are required in the biosynthetic route to a key precursor of the Lycopodium alkaloids by catalysing a stereospecific Mannich-like condensation and subsequent bicyclic scaffold generation. Also, we describe a series of scaffold tailoring steps that generate the optimized acetylcholinesterase inhibition activity of huperzine A5. Our findings suggest a broader involvement of CAH-like enzymes in specialized metabolism and demonstrate how successive scaffold tailoring can drive potency against a neurological protein target.
WSAVA Animal Welfare Guidelines

Ryan S, Bacon H, Endenburg N, Hazel S, Jouppi R, Lee N, et al.

J Small Anim Pract, 2019 05;60(5):E1-E46.
PMID: 31026337 DOI: 10.1111/jsap.12998
WSAVA animal welfare guidelines for veterinary practitioners and veterinary teams

Animal Welfare Guidelines Group, Ryan S, Bacon H, Endenburg N, Hazel S, Jouppi R, et al.

J Small Anim Pract, 2019 05;60(5):265-267.
PMID: 30859578 DOI: 10.1111/jsap.12988
Animal Welfare Worldwide, the Opinion of Practicing Veterinarians

Endenburg N, Takashima G, van Lith HA, Bacon H, Hazel SJ, Jouppi R, et al.

J Appl Anim Welf Sci, 2020 01 28;24(3):215-237.
PMID: 31992080 DOI: 10.1080/10888705.2020.1717340

The objective of this study was to investigate the animal welfare issues considered the most important by companion animal veterinarians worldwide. For this purpose, a global survey of several potential animal welfare issues was distributed via SurveyMonkey® in multiple languages. The distribution of survey responses differed by region. The main animal welfare concern reported worldwide was obesity, although there were differences across regions, possibly due to cultural and socioeconomic factors. Anthropomorphism (attributing human qualities or characteristics to an animal) was an issue in western countries but less so in Asia, Africa, and Oceania. There were significant differences between Asia and Europe, Africa, and Oceania in the importance and prevalence of convenience euthanasia. There were also age and sex differences in participant responses, with older veterinarians reporting fewer welfare problems than younger veterinarians, and female veterinarians reporting more welfare issues than their male counterparts.
Fulltext Enhanced diagnosis of advanced fibrosis and cirrhosis in individuals with NAFLD using FibroScan-based Agile scores

Sanyal AJ, Foucquier J, Younossi ZM, Harrison SA, Newsome PN, Chan WK, et al.

J Hepatol, 2023 Feb;78(2):247-259.
PMID: 36375686 DOI: 10.1016/j.jhep.2022.10.034

BACKGROUND & AIMS: Currently available non-invasive tests, including fibrosis-4 index (FIB-4) and liver stiffness measurement (LSM by VCTE), are highly effective at excluding advanced fibrosis (AF) (F ≥3) or cirrhosis in people with non-alcoholic fatty liver disease (NAFLD), but only have moderate ability to rule-in these conditions. Our objective was to develop and validate two new scores (Agile 4 and Agile 3+) to identify cirrhosis or AF, respectively, with optimized positive predictive value and fewer indeterminate results, in individuals with NAFLD attending liver clinics.
METHODS: This international study included seven adult cohorts with suspected NAFLD who underwent liver biopsy, LSM and blood sampling during routine clinical practice or screening for trials. The population was randomly divided into a training set and an internal validation set, on which the best-fitting logistic regression model was built, and performance and goodness of fit were assessed, respectively. Furthermore, both scores were externally validated on two large cohorts. Cut-offs for high sensitivity and specificity were derived in the training set to rule-out and rule-in cirrhosis or AF and then tested in the validation set and compared to FIB-4 and LSM.
RESULTS: Each score combined LSM, AST/ALT ratio, platelets, sex and diabetes status, as well as age for Agile 3+. Calibration plots for Agile 4 and Agile 3+ indicated satisfactory to excellent goodness of fit. Agile 4 and Agile 3+ outperformed FIB-4 and LSM in terms of AUROC, percentage of patients with indeterminate results and positive predictive value to rule-in cirrhosis or AF.
CONCLUSIONS: The two novel non-invasive scores improve identification of cirrhosis or AF among individuals with NAFLD attending liver clinics and reduce the need for liver biopsy in this population.
IMPACT AND IMPLICATIONS: Non-invasive tests currently used to identify patients with advanced fibrosis or cirrhosis, such as fibrosis-4 index and liver stiffness measurement by vibration-controlled transient elastography, have high negative predictive values but high false positive rates, while results are indeterminate for a large number of cases. This study provides scores that will help the clinician diagnose advanced fibrosis or cirrhosis. These new easy-to-implement scores will help liver specialists to better identify (1) patients who need more intensive follow-up, (2) patients who should be referred for inclusion in therapeutic trials, and (3) which patients should be treated with pharmacological agents when effective therapies are approved.
Erratum to "The histology of ovarian cancer: Worldwide distribution and implications for international survival comparisons (CONCORD-2)" [Gynecol. Oncol. 144 (2017) 405-413]

Matz M, Coleman MP, Sant M, Chirlaque MD, Visser O, Gore M, et al.

Gynecol Oncol, 2017 Jul 05.
PMID: 28687170 DOI: 10.1016/j.ygyno.2017.06.032