Laetitia Coassolo (Voilquin)
Senior Research Scientist - Basic Life, Pathology Sponsored Projects
Bio
I received my PharmD from the University of Strasbourg (France) in 2018. I completed my PhD in Oncology and Cell Biology in 2020 in Dr. Catherine Tomasetto's group in IGBMC (France) studying cell metabolism and cell signaling in breast cancer. I completed my postdoctal training in Dr. Katrin Svensson lab at Stanford University focusing on understanding the molecular mechanisms of non-classical hormones in metabolic diseases.
Current Role at Stanford
I am a Senior Research Scientist in Dr. Katrin Svensson's lab. I am interested in mapping tissue-specific peptide secretion to identify orphan peptide hormones.
Honors & Awards
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AHA Postdoctoral Fellowship, American Heart Association (2023-2024)
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Dean's fellowship, School of Medicine, Stanford (2022)
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Ph.D research grant, allocated by the French Government after competitive exam, Doctoral School of Strasbourg (2016-2019)
Boards, Advisory Committees, Professional Organizations
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member, American Heart Association (AHA) (2021 - Present)
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member, Association for Women in Science (AWIS) (2022 - Present)
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member, Stanford Cardiovascular Institute CVI (2022 - Present)
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member, Stanford Diabetes Research Center (2021 - Present)
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member, Maternal & Child Health Research Institute (MCHRI) (2021 - Present)
Professional Education
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PhD, Doctoral School of Strasbourg, France, Molecular and cellular biology, lipid metabolism, cancer biology (2020)
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PharmD, University of Strasbourg, France, Pharmacy (2018)
Patents
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Katrin J Svensson, Laetitia Voilquin. "United States Patent S22-296 BRINP2-derived peptide compositions for treating obesity and weight management", Leland Stanford Junior University
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Katrin J Svensson, Laetitia Voilquin, Niels Banhos Danneskiold-Samsoe, Jameel Barkat Lone. "United States Patent S24-073 BRINP3-derived peptides for obesity and digestive disorders", Leland Stanford Junior University, Mar 29, 2024
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Katrin J. Svensson, Laetitia Voilquin. "United States Patent 63/226,600 Therapeutic Uses of Isthmin Protein", Leland Stanford Junior University, Jul 28, 2022
All Publications
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A secondary β-hydroxybutyrate metabolic pathway linked to energy balance.
bioRxiv : the preprint server for biology
2024
Abstract
β-hydroxybutyrate (BHB) is an abundant ketone body. To date, all known pathways of BHB metabolism involve interconversion of BHB and primary energy intermediates. Here we show that CNDP2 controls a previously undescribed secondary BHB metabolic pathway via enzymatic conjugation of BHB and free amino acids. This BHB-ylation reaction produces a family of endogenous ketone metabolites, the BHB-amino acids. Genetic ablation of CNDP2 in mice eliminates tissue amino acid BHB-ylation activity and reduces BHB-amino acid levels. Administration of BHB-Phe, the most abundant BHB-amino acid, to obese mice activates neural populations in the hypothalamus and brainstem and suppresses feeding and body weight. Conversely, CNDP2-KO mice exhibit increased food intake and body weight upon ketosis stimuli. CNDP2-dependent amino acid BHB-ylation and BHB-amino acid metabolites are also conserved in humans. Therefore, the metabolic pathways of BHB extend beyond primary metabolism and include secondary ketone metabolites linked to energy balance.
View details for DOI 10.1101/2024.09.09.612087
View details for PubMedID 39314488
View details for PubMedCentralID PMC11418978
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PTER is a N-acetyltaurine hydrolase that regulates feeding and obesity.
Nature
2024
Abstract
Taurine is a conditionally essential micronutrient and one of the most abundant amino acids in humans1-3. In endogenous taurine metabolism, dedicated enzymes are involved in the biosynthesis of taurine from cysteine and in the downstream metabolism of secondary taurine metabolites4,5. One taurine metabolite is N-acetyltaurine6. Levels of N-acetyltaurine are dynamically regulated by stimuli that alter taurine or acetate flux, including endurance exercise7, dietary taurine supplementation8 and alcohol consumption6,9. So far, the identities of the enzymes involved in N-acetyltaurine metabolism, and the potential functions of N-acetyltaurine itself, have remained unknown. Here we show that the body mass index associated orphan enzyme phosphotriesterase-related (PTER)10 is a physiological N-acetyltaurine hydrolase. In vitro, PTER catalyses the hydrolysis of N-acetyltaurine to taurine and acetate. In mice, PTER is expressed in the kidney, liver and brainstem. Genetic ablation of Pter in mice results in complete loss of tissue N-acetyltaurine hydrolysis activity and a systemic increase in N-acetyltaurine levels. After stimuli that increase taurine levels, Pter knockout mice exhibit reduced food intake, resistance to diet-induced obesity and improved glucose homeostasis. Administration of N-acetyltaurine to obese wild-type mice also reduces food intake and body weight in a GFRAL-dependent manner. These data place PTER into a central enzymatic node of secondary taurine metabolism and uncover a role for PTER and N-acetyltaurine in body weight control and energy balance.
View details for DOI 10.1038/s41586-024-07801-6
View details for PubMedID 39112712
View details for PubMedCentralID 3501277
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A class of secreted mammalian peptides with potential to expand cell-cell communication.
Nature communications
2023; 14 (1): 8125
Abstract
Peptide hormones and neuropeptides are signaling molecules that control diverse aspects of mammalian homeostasis and physiology. Here we provide evidence for the endogenous presence of a sequence diverse class of blood-borne peptides that we call "capped peptides." Capped peptides are fragments of secreted proteins and defined by the presence of two post-translational modifications - N-terminal pyroglutamylation and C-terminal amidation - which function as chemical "caps" of the intervening sequence. Capped peptides share many regulatory characteristics in common with that of other signaling peptides, including dynamic physiologic regulation. One capped peptide, CAP-TAC1, is a tachykinin neuropeptide-like molecule and a nanomolar agonist of mammalian tachykinin receptors. A second capped peptide, CAP-GDF15, is a 12-mer peptide cleaved from the prepropeptide region of full-length GDF15 that, like the canonical GDF15 hormone, also reduces food intake and body weight. Capped peptides are a potentially large class of signaling molecules with potential to broadly regulate cell-cell communication in mammalian physiology.
View details for DOI 10.1038/s41467-023-43857-0
View details for PubMedID 38065934
View details for PubMedCentralID 5946320
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Rapid and accurate deorphanization of ligand-receptor pairs using AlphaFold.
bioRxiv : the preprint server for biology
2023
Abstract
Secreted proteins are extracellular ligands that play key roles in paracrine and endocrine signaling, classically by binding cell surface receptors. Experimental assays to identify new extracellular ligand-receptor interactions are challenging, which has hampered the rate of novel ligand discovery. Here, using AlphaFold-multimer, we developed and applied an approach for extracellular ligand-binding prediction to a structural library of 1,108 single-pass transmembrane receptors. We demonstrate high discriminatory power and a success rate of close to 90 % for known ligand-receptor pairs where no a priori structural information is required. Importantly, the prediction was performed on de novo ligand-receptor pairs not used for AlphaFold training and validated against experimental structures. These results demonstrate proof-of-concept of a rapid and accurate computational resource to predict high-confidence cell-surface receptors for a diverse set of ligands by structural binding prediction, with potentially wide applicability for the understanding of cell-cell communication.
View details for DOI 10.1101/2023.03.16.531341
View details for PubMedID 36993313
View details for PubMedCentralID PMC10055078
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Mapping transcriptional heterogeneity and metabolic networks in fatty livers at single-cell resolution.
iScience
2023; 26 (1): 105802
Abstract
Non-alcoholic fatty liver disease is a heterogeneous disease with unclear underlying molecular mechanisms. Here, we perform single-cell RNA sequencing of hepatocytes and hepatic non-parenchymal cells to map the lipid signatures in mice with non-alcoholic fatty liver disease (NAFLD). We uncover previously unidentified clusters of hepatocytes characterized by either high or low srebp1 expression. Surprisingly, the canonical lipid synthesis driver Srebp1 is not predictive of hepatic lipid accumulation, suggestive of other drivers of lipid metabolism. By combining transcriptional data at single-cell resolution with computational network analyses, we find that NAFLD is associated with high constitutive androstane receptor (CAR) expression. Mechanistically, CAR interacts with four functional modules: cholesterol homeostasis, bile acid metabolism, fatty acid metabolism, and estrogen response. Nuclear expression of CAR positively correlates with steatohepatitis in human livers. These findings demonstrate significant cellular differences in lipid signatures and identify functional networks linked to hepatic steatosis in mice and humans.
View details for DOI 10.1016/j.isci.2022.105802
View details for PubMedID 36636354
View details for PubMedCentralID PMC9830221
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STARD3: A New Biomarker in HER2-Positive Breast Cancer.
Cancers
2023; 15 (2)
Abstract
Pathological complete response (pCR) after neoadjuvant systemic treatment (NST) is an important prognostic factor in HER2-positive breast cancer. The majority of HER2-positive breast cancers are amplified at the HER2 gene locus, several genes are co-amplified with HER2, and a subset of them are co-expressed. The STARD3 gene belongs to the HER2 amplicon, and its role as a predictive marker was never addressed. The objective of this study was to investigate the predictive value of STARD3 protein expression on NST pathological response in HER2-positive breast cancer. In addition, we studied the prognostic value of this marker.METHODS: We conducted a retrospective study between 2007 and 2020 on 112 patients with non-metastatic HER2-positive breast cancer treated by NST and then by surgery. We developed an immunohistochemistry assay for STARD3 expression and subcellular localization and determined a score for STARD3-positivity. As STARD3 is an endosomal protein, its expression was considered positive if the intracellular signal pattern was granular.RESULTS: In this series, pCR was achieved in half of the patients. STARD3 was positive in 86.6% of cases and was significantly associated with pCR in univariate analysis (p = 0.013) and after adjustment on other known pathological parameters (p = 0.044). Performances on pCR prediction showed high sensitivity (96%) and negative predictive value (87%), while specificity was 23% and positive predictive value was 56%. Overall, specific, relapse-free, and distant metastasis-free survivals were similar among STARD3 positive and negative groups, independently of other prognosis factors.CONCLUSION: NST is an opportunity for HER2-positive cancers. In this series of over a hundred HER2-positive and non-metastatic patients, a STARD3-negative score was associated with the absence of pathological complete response. This study suggests that determining STARD3 overexpression status on initial biopsies of HER2-positive tumors is an added value for the management of a subset of patients with high probability of no pathological response.
View details for DOI 10.3390/cancers15020362
View details for PubMedID 36672312
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New players of the adipose secretome: Therapeutic opportunities and challenges.
Current opinion in pharmacology
2022; 67: 102302
Abstract
Adipose tissue is a functional endocrine organ comprised of adipocytes and other cell types that are known to secrete a multiplicity of adipose-derived factors, including lipids and proteins. It is well established that adipose tissue and its secretome can impact systemic energy homeostasis. The endocrine and paracrine effects of adipose-derived factors have been widely studied over the last several decades. Owing to technological advances in genomics and proteomics, several additional adipose-derived protein factors have recently been identified. By learning from previous efforts, the next challenge will be to leverage these discoveries for the prevention or treatment of metabolic disorders. Here, we discuss recently discovered adipose-derived proteins secreted from white or brown adipose tissue and the opportunities and challenges of translating these biological findings into disease therapeutics.
View details for DOI 10.1016/j.coph.2022.102302
View details for PubMedID 36195010
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Phosphoproteomic mapping reveals distinct signaling actions and activation of muscle protein synthesis by Isthmin-1
eLife
2022
View details for DOI 10.7554/eLife.80014
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Isthmin-1 is an adipokine that promotes glucose uptake and improves glucose tolerance and hepatic steatosis.
Cell metabolism
2021
Abstract
With the increasing prevalence of type 2 diabetes and fatty liver disease, there is still an unmet need to better treat hyperglycemia and hyperlipidemia. Here, we identify isthmin-1 (Ism1) as an adipokine and one that has a dual role in increasing adipose glucose uptake while suppressing hepatic lipid synthesis. Ism1 ablation results in impaired glucose tolerance, reduced adipose glucose uptake, and reduced insulin sensitivity, demonstrating an endogenous function for Ism1 in glucose regulation. Mechanistically, Ism1 activates a PI3K-AKT signaling pathway independently of the insulin and insulin-like growth factor receptors. Notably, while the glucoregulatory function is shared with insulin, Ism1 counteracts lipid accumulation in the liver by switching hepatocytes from a lipogenic to a protein synthesis state. Furthermore, therapeutic dosing of recombinant Ism1 improves diabetes in diet-induced obese mice and ameliorates hepatic steatosis in a diet-induced fatty liver mouse model. These findings uncover an unexpected, bioactive protein hormone that might have simultaneous therapeutic potential for diabetes and fatty liver disease.
View details for DOI 10.1016/j.cmet.2021.07.010
View details for PubMedID 34348115
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FFAT motif phosphorylation controls formation and lipid transfer function of inter-organelle contacts
EMBO JOURNAL
2020; 39 (23): e104369
Abstract
Organelles are physically connected in membrane contact sites. The endoplasmic reticulum possesses three major receptors, VAP-A, VAP-B, and MOSPD2, which interact with proteins at the surface of other organelles to build contacts. VAP-A, VAP-B, and MOSPD2 contain an MSP domain, which binds a motif named FFAT (two phenylalanines in an acidic tract). In this study, we identified a non-conventional FFAT motif where a conserved acidic residue is replaced by a serine/threonine. We show that phosphorylation of this serine/threonine is critical for non-conventional FFAT motifs (named Phospho-FFAT) to be recognized by the MSP domain. Moreover, structural analyses of the MSP domain alone or in complex with conventional and Phospho-FFAT peptides revealed new mechanisms of interaction. Based on these new insights, we produced a novel prediction algorithm, which expands the repertoire of candidate proteins with a Phospho-FFAT that are able to create membrane contact sites. Using a prototypical tethering complex made by STARD3 and VAP, we showed that phosphorylation is instrumental for the formation of ER-endosome contacts, and their sterol transfer function. This study reveals that phosphorylation acts as a general switch for inter-organelle contacts.
View details for DOI 10.15252/embj.2019104369
View details for Web of Science ID 000585124000001
View details for PubMedID 33124732
View details for PubMedCentralID PMC7705450
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Modular Conjugation of a Potent Anti-HER2 Immunotoxin Using Coassociating Peptides
BIOCONJUGATE CHEMISTRY
2020; 31 (10): 2421-2430
Abstract
Immunotoxins are emerging candidates for cancer therapeutics. These biomolecules consist of a cell-targeting protein combined to a polypeptide toxin. Associations of both entities can be achieved either chemically by covalent bonds or genetically creating fusion proteins. However, chemical agents can affect the activity and/or stability of the conjugate proteins, and additional purification steps are often required to isolate the final conjugate from unwanted byproducts. As for fusion proteins, they often suffer from low solubility and yield. In this report, we describe a straightforward conjugation process to generate an immunotoxin using coassociating peptides (named K3 and E3), originating from the tetramerization domain of p53. To that end, a nanobody targeting the human epidermal growth factor receptor 2 (nano-HER2) and a protein toxin fragment from Pseudomonas aeruginosa exotoxin A (TOX) were genetically fused to the E3 and K3 peptides. Entities were produced separately in Escherichia coli in soluble forms and at high yields. The nano-HER2 fused to the E3 or K3 helixes (nano-HER2-E3 and nano-HER2-K3) and the coassembled immunotoxins (nano-HER2-K3E3-TOX and nano-HER2-E3K3-TOX) presented binding specificity on HER2-overexpressing cells with relative binding constants in the low nanomolar to picomolar range. Both toxin modules (E3-TOX and K3-TOX) and the combined immunotoxins exhibited similar cytotoxicity levels compared to the toxin alone (TOX). Finally, nano-HER2-K3E3-TOX and nano-HER2-E3K3-TOX evaluated on various breast cancer cells were highly potent and specific to killing HER2-overexpressing breast cancer cells with IC50 values in the picomolar range. Altogether, we demonstrate that this noncovalent conjugation method using two coassembling peptides can be easily implemented for the modular engineering of immunotoxins targeting different types of cancers.
View details for DOI 10.1021/acs.bioconjchem.0c00482
View details for Web of Science ID 000584490900017
View details for PubMedID 32996763
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Another hijack! Some enteroviruses co-opt the c10orf76/PI4KB complex for their own good.
EMBO reports
2020; 21 (2): e49876
Abstract
Enteroviruses, members of the Picornaviridae family, are non-enveloped and single-stranded RNA viruses responsible for several human diseases. During infection, these viruses build membrane-bound organelles, called replication organelles (ROs), where new virions are assembled. ROs are highly enriched in phosphatidylinositol 4-phosphate (PI4P) produced by the host lipid kinase PI4KB. In this issue of EMBO Reports, McPhail et al [1] characterize a complex, formed by PI4KB and the c10orf76 protein, which is involved in PI4P production. They show that this machinery is hijacked by specific enteroviruses such as coxsackievirus A10 for their replication.
View details for DOI 10.15252/embr.201949876
View details for PubMedID 31919962
View details for PubMedCentralID PMC7001151
- STARD3: A Swiss Army Knife for Intracellular Cholesterol Transport STARD3: A Swiss Army Knife for Intracellular Cholesterol Transport 2019
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Intracellular and Plasma Membrane Cholesterol Labeling and Quantification Using Filipin and GFP-D4
INTRACELLULAR LIPID TRANSPORT: METHODS AND PROTOCOLS
2019; 1949: 137-152
Abstract
Cholesterol, a major component of biological membranes, is rapidly trafficked and unevenly distributed between organelles. Anomalies of intracellular cholesterol distribution are the hallmark of a number of lysosomal lipid storage disorders. A major methodological obstacle for studying cholesterol trafficking is tracing this molecule in situ. The use of fluorescent probes that specifically bind cholesterol allows the visualization and imaging of cellular cholesterol. Here, we describe a series of assays optimized for quantifying free cholesterol in cell populations and at the single cell level, both at the plasma membrane and inside cells. These methods use two fluorescent probes: the D4 fragment of perfringolysin O fused to GFP (GFP-D4) and the polyene macrolide filipin. First, we report a robust method for quantifying plasma membrane cholesterol by flow cytometry using the GFP-D4 probe. Second, to optically distinguish and quantify intracellular cholesterol accumulation, we have adapted the classical filipin cholesterol staining protocol. Indeed, we observed that treatment of living cells with methyl-β-cyclodextrin, a chemical known to extract cholesterol from the plasma membrane, improves the visualization of the intracellular cholesterol pool with filipin. To complement these staining procedures, we developed an image analysis protocol based on image segmentation to quantify, in a robust manner, intracellular cholesterol stained with filipin. Thus, this chapter is a guideline for cellular cholesterol staining and signal quantification.
View details for DOI 10.1007/978-1-4939-9136-5_11
View details for Web of Science ID 000608835800012
View details for PubMedID 30790254