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Wong, A. Y. L.

Publications and source records attributed to Wong, A. Y. L..

2 recordsLinked to original sources

A scalable approach to absolute quantitation in metabolomics

Mass spectrometry-based metabolomics allows for the quantitation of metabolite levels in diverse biological samples. The traditional method of converting peak areas to absolute concentrations involves the use of matched heavy isotopologues. However, this approach is laborious and limited to a small number of metabolites. We addressed these limitations by developing PyxisTM, a machine learning-based technology which converts raw mass spectrometry data to absolute concentration measurements without the need for per-analyte standards. Here, we demonstrate Pyxis performance by quantifying metabolome concentration dynamics in murine blood plasma. Pyxis performed equivalently to traditional quantitation workflows used by research institutions, with a fraction of the time needed for analysis. We show that absolute quantitation by Pyxis can be expanded to include concentrations for additional metabolites, without the need to acquire new data. Furthermore, Pyxis allows for absolute quantitation as part of an untargeted metabolomics workflow. By removing the bottleneck of per-analyte standards, Pyxis allows for absolute quantitation in metabolomics that is scalable to large numbers of metabolites. The ability of Pyxis to make concentration-based measurements across the metabolome has the potential to deepen our understanding of diverse metabolic perturbations.

systems biology↗

Folate depletion induces erythroid differentiation through perturbation of de novo purine synthesis

All dividing cells require the essential vitamin folate. Hematopoietic cells harbor a unique sensitivity to folate deprivation, as implied by the development of folate-deficient anemia and the utility of anti-folate chemotherapy in blood cancer. To study this metabolic sensitivity, we applied mild folate depletion to human and mouse erythroid cell lines, as well as primary murine erythroid progenitors. We show that folate depletion induces early blockade of purine synthesis that is followed by enhanced heme metabolism, hemoglobin synthesis and erythroid differentiation. This finding is phenocopied by inhibition of folate metabolism using SHIN1, an inhibitor of the folate enzymes SHMT1/2. The metabolically-driven differentiation is rescued by supplementation of purine precursors, yet occurs independent of nucleotide sensing through mTORC1 and AMPK. Our work profiles the metabolic response to folate depletion in erythroid cells and suggest that premature differentiation of folate-deprived erythroid progenitor cells is a mechanistic etiology to folate-deficiency induced anemia.

molecular biology↗