Life Sciences Research for Lifelong Health

Michael Wakelam

Research Summary

We aim to understand the essential physiological functions of lipids. Lipids are highly dynamic structures with structural, metabolic and signalling roles. To fully understand the roles that lipids have in cell function during ageing we need the ability to determine their individual changes.

The cellular lipidome is extremely complex, with distinct classes of lipids each containing many molecular species that can differ both in the length of each acyl chain present and in the number and position of double bonds.

In our lab we have pioneered the use of high-sensitivity liquid chromatography-mass spectrometry (LC-MS) technology to rapidly and comprehensively measure the levels of lipids in a wide range of cell types, tissues and tumours. The lipidome of a cell typically comprises of ~ 1500 distinct lipid species measurable with current LC-MS technology. However, this number is most likely an underestimate since there are theoretically closer to 10 000 distinct lipid species in the lipidome.

The principal aim of our laboratory is to better understand how the distinct lipid species of a cell’s lipidome function during the healthy ageing of the whole animal.

​To achieve this we use a multidisciplinary approach combining LC-MS analysis, protein biochemistry, cell biology and genetic manipulation of model organisms. This allows us to identify the cellular signalling pathways and processes that individual lipid species regulate, and to investigate how the enzymes that determine the composition of the lipidome are regulated in response to changes in the environment.

Latest Publications

Modeling Meets Metabolomics-The WormJam Consensus Model as Basis for Metabolic Studies in the Model Organism .
Witting M, Hastings J, Rodriguez N, Joshi CJ, Hattwell JPN, Ebert PR, van Weeghel M, Gao AW, Wakelam MJO, Houtkooper RH, Mains A, Le Novère N, Sadykoff S, Schroeder F, Lewis NE, Schirra HJ, Kaleta C, Casanueva O

Metabolism is one of the attributes of life and supplies energy and building blocks to organisms. Therefore, understanding metabolism is crucial for the understanding of complex biological phenomena. Despite having been in the focus of research for centuries, our picture of metabolism is still incomplete. Metabolomics, the systematic analysis of all small molecules in a biological system, aims to close this gap. In order to facilitate such investigations a blueprint of the metabolic network is required. Recently, several metabolic network reconstructions for the model organism have been published, each having unique features. We have established the WormJam Community to merge and reconcile these (and other unpublished models) into a single consensus metabolic reconstruction. In a series of workshops and annotation seminars this model was refined with manual correction of incorrect assignments, metabolite structure and identifier curation as well as addition of new pathways. The WormJam consensus metabolic reconstruction represents a rich data source not only for network-based approaches like flux balance analysis, but also for metabolomics, as it includes a database of metabolites present in , which can be used for annotation. Here we present the process of model merging, correction and curation and give a detailed overview of the model. In the future it is intended to expand the model toward different tissues and put special emphasizes on lipid metabolism and secondary metabolism including ascaroside metabolism in accordance to their central role in physiology.

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Frontiers in molecular biosciences, 5, 2296-889X, 96, 2018

PMID: 30488036

3D growth of cancer cells elicits sensitivity to kinase inhibitors but not lipid metabolism modifiers.
Jones DT, Valli A, Haider S, Zang Q, Smethurst E, Schug ZT, Peck B, Aboagye EO, Critchlow SE, Schulze A, Gottlieb E, Wakelam MJO, Adrian HL

Tumour cells exhibit altered lipid metabolism compared to normal cells. Cell signalling kinases are important for regulating lipid synthesis and energy storage. How upstream kinases regulate lipid content, versus direct targeting of lipid metabolising enzymes, is currently unexplored. We evaluated intracellular lipid concentrations in prostate and breast tumour spheroids, treated with drugs directly inhibiting metabolic enzymes FASN, ACC, DGAT and PDHK, or cell signalling kinase enzymes PI3K, AKT and mTOR with lipidomic analysis. We assessed whether baseline lipid profiles corresponded to inhibitors' effectiveness in modulating lipid profiles in 3D-growth, and their relationship to therapeutic activity. Inhibitors against PI3K, AKT and mTOR significantly inhibited MDA-MB-468 and PC3 cell growth in 2D and 3D spheroid growth, while moderately altering lipid content. Conversely, metabolism inhibitors against FASN and DGAT altered lipid content most effectively, while only moderately inhibiting growth compared to kinase inhibitors. The FASN and ACC inhibitors' effectiveness in MDA-MB-468, versus PC3, suggested the former depended more on synthesis whereas the latter may salvage lipids. Although baseline lipid profiles didn't predict growth effects, lipid changes on therapy matched the growth effects of FASN and DGAT inhibitors. Several phospholipids, including phosphatidylcholine, were also upregulated following treatment, possibly via the Kennedy pathway. As this promotes tumour growth, combination studies should include drugs targeting it. Two-dimensional drug screening may miss important metabolism inhibitors or underestimate their potency. Clinical studies should consider serial measurements of tumour lipids to prove target modulation. Pre-therapy tumour classification by de novo lipid synthesis versus uptake may help demonstrate efficacy.

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Molecular cancer therapeutics, , 1538-8514, , 2018

PMID: 30478149

CD151 regulates expression of FGFR2 in breast cancer cells via PKC-dependent pathways.
Sadej R, Lu X, Turczyk L, Novitskaya V, Lopez-Clavijo AF, Kordek R, Potemski P, Wakelam MJO, Romanska H, Berditchevski F

Expression of the tetraspanin CD151 is frequently upregulated in epithelial malignancies and correlates with poor prognosis. Here we report that CD151 is involved in regulation of the expression of fibroblast growth factor receptor 2 (FGFR2). Depletion of CD151 in breast cancer cells resulted in an increased level of FGFR2. Accordingly, an inverse correlation between CD151 and FGFR2 was observed in breast cancer tissues. CD151-dependent regulation of the FGFR2 expression relies on post-transcriptional mechanisms involving HuR/ELAVL1, a multifunctional RNA binding protein, and the assembly of processing bodies (P-bodies). Depletion of CD151 correlated with inhibition of PKC, a well-established downstream target of CD151. Accordingly, the levels of dialcylglycerol species were decreased in CD151-negative cells, and inhibition of PKC resulted in the increased expression of FGFR2. Whilst expression of FGFR2 itself did not correlate with any of the clinicopathological data, the FGFR2-/CD151+ patients are more likely to develop lymph node metastasis. Conversely, FGFR2-/CD151- patients demonstrated better overall survival. These results illustrate functional interdependency between CD151 complexes and FGFR2 and suggest a previously unsuspected role of CD151 in breast tumourigenesis.

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Journal of cell science, , 1477-9137, , 2018

PMID: 30257985

Group Members

Latest Publications

Modeling Meets Metabolomics-The WormJam Consensus Model as Basis for Metabolic Studies in the Model Organism .

Witting M, Hastings J, Rodriguez N

Frontiers in molecular biosciences
5 2296-889X:96 (2018)

PMID: 30488036

3D growth of cancer cells elicits sensitivity to kinase inhibitors but not lipid metabolism modifiers.

Jones DT, Valli A, Haider S

Molecular cancer therapeutics
1538-8514: (2018)

PMID: 30478149

CD151 regulates expression of FGFR2 in breast cancer cells via PKC-dependent pathways.

Sadej R, Lu X, Turczyk L

Journal of cell science
1477-9137: (2018)

PMID: 30257985

C. elegans Eats Its Own Intestine to Make Yolk Leading to Multiple Senescent Pathologies.

Ezcurra M, Benedetto A, Sornda T

Current biology : CB
1879-0445: (2018)

PMID: 30100339

Extracellular vesicles : lipids as key components of their biogenesis and functions.

Record M, Silvente-Poirot S, Poirot M

Journal of lipid research
1539-7262: (2018)

PMID: 29764923

Phospholipid signaling in innate immune cells.

O'Donnell VB, Rossjohn J, Wakelam MJ

The Journal of clinical investigation
1558-8238: (2018)

PMID: 29683435

Deciphering lipid structures based on platform-independent decision rules.

Hartler J, Triebl A, Ziegl A

Nature methods
1548-7105: (2017)

PMID: 29058722

Autotaxin-lysophosphatidic acid receptor signalling regulates hepatitis C virus replication.

Farquhar MJ, Humphreys IS, Rudge SA

Journal of hepatology
1600-0641: (2017)

PMID: 28126468