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ARGUELLO, R. J.

Publications and source records attributed to ARGUELLO, R. J..

6 recordsLinked to original sources

The Pentose Phosphate Pathway Regulates Myelo-Lymphoid Lineage Specification

Following infection, hematopoietic stem and progenitor cells (HSPCs) support immunity by increasing the rate of innate immune cell production but the metabolic cues that guide this process are unknown. To address this question, we combined in situ RNA barcoding and metabolomics approaches to perform metabolic state-fate mapping in vivo. This approach revealed a subset of myeloid-biased HSPCs that express a distinct set of metabolic enzymes and transporters as well as the surface marker CD62L. Metabolically, CD62Lhigh HSPCs have differential activity of the pentose phosphate pathway (PPP), OXPHOS and translation, as well as differential levels of S-adenosylmethionine (SAM) cycle metabolites associated with epigenetic modifications. Inhibition of the PPP skews HSPC lineage fate decisions by disrupting myeloid associated enhancers, while simultaneously increasing enhancer activity for the master B-lymphoid regulator Ikaros. In vivo, overexpression of glucose-6-phosphate dehydrogenase, a rate limiting enzyme of the PPP, skewed HSPC output from B-lymphocytes. In summary, our data shows that HSPCs undergo significant metabolic changes to facilitate the bioenergetic and epigenetic demands of myeloid versus lymphoid lineage specification. We highlight a key role for the pentose phosphate pathway which modulates myeloid rather than lymphoid commitment by shaping the HSPC enhancer landscape, providing proof of principle that HSPC metabolism can be targeted to modulate immune system dynamics.

immunology↗

Connecting mitochondrial metabolism and mitotic fidelity to control vulnerability of high grade serous ovarian cancer patients to taxane-based chemotherapy

High-grade serous ovarian carcinoma (HGSOC), which accounts for approximately 75% of ovarian cancer cases, is associated with poor clinical outcome. Although most patients initially achieve a complete response to conventional chemotherapy, HGSOC almost invariably develops chemoresistance. There is therefore an urgent need to identify predictive biomarkers of treatment response. Here, through integrative analyses of molecular and clinical data from HGSOC patient cohorts, we identify syntabulin (SYBU), a microtubule-associated protein originally described as a regulator of mitochondrial transport along neuronal microtubules, as a critical determinant of chemosensitivity in HGSOC. Low SYBU expression in tumors correlates with higher tumor grade and increased aggressiveness, yet paradoxically with enhanced sensitivity to chemotherapy. SYBU-deficient cancer cells display impaired oxidative phosphorylation and a metabolic shift toward glycolysis characteristic of the Warburg effect, together with mitotic defects such as chromosome lagging that promote aneuploidy. Mechanistically, syntabulin forms a complex with the mitochondrial outer membrane porin VDAC1 and the inner membrane protein MIC60, a major regulator of mitochondrial cristae organization. Functionally, the syntabulin-MIC60 axis controls cristae architecture and mitotic fidelity, thereby connecting mitochondrial metabolism to cell division. These findings highlight new therapeutic vulnerabilities to overcome chemoresistance in ovarian cancer. SIGNIFICANT STATEMENTOvarian cancer remains the deadliest gynecologic malignancy, largely due to the systematic emergence of resistance to chemotherapy. Identifying molecular mechanisms involved in response to treatment is therefore a major clinical challenge. Here, we uncover an unexpected role for the mitochondrial protein syntabulin in regulating chemotherapy sensitivity in high-grade serous ovarian cancer. We demonstrate that syntabulin coordinates cancer cell mitotic progression with mitochondrial structure and metabolism through interactions with cristae-shaping proteins. These findings reveal a previously unrecognized link between mitotic regulation and mitochondrial architecture, and identify syntabulin as a potential therapeutic target in ovarian cancer to induce vulnerability to taxane-based chemotherapy.

cancer biology↗

Mgl2+ cDC2 triggering of fungal allergic inflammation depends on a spore induced glycolytic shift fuelled by local availability of glucose

Fungal spores are a major cause of severe asthmatic disease. However, the precise events that cause individuals to become sensitised to spores are poorly understood. Mgl2+ type 2 conventional dendritic cells (Mgl2+ cDC2s) are critical in coordinating allergic airway inflammation in mice following repeated exposure to inhaled spores. Yet, whether these DCs are directly acquiring spores from the airway, and the downstream mechanism(s) upon fungal uptake causing DCs to trigger allergic inflammation are unknown. Here we find that spores are acquired by lung DCs after inhalation although these events are rare ([~] 0.5% of the cDC2 population). Transcriptomics on isolated spore+ Mgl2+ cDC2s, compared to spore- Mgl2+ cDC2s from the same environment, revealed that a major consequence of fungal uptake was a boost in metabolic activity. Single-cell metabolic profiling revealed this increase in Mgl2+ cDC2 metabolism upon spore acquisition was fuelled by a glycolytic shift. To pinpoint if nutrient availability and acquisition is an important determinant of this response, mass spectrometry-based metabolomics revealed that, during fungal allergic inflammation, the local airway nutrient environment is altered. To ascertain which of these could be fuelling DC responses, we identified which substrates that feed into glycolysis were crucial. Of these, we found that glucose availability acts as a key rheostat in shaping cDC2 responses to spores. These data highlight a crucial role for glycolytic metabolism in driving cDC2 responses to spores, which is governed by glucose availability, defining novel targets for future therapeutic development of fungal allergic inflammation.

immunology↗

Lipid-mediated GPR32 signaling reprograms macrophage metabolism to impair anti-tuberculous immunity

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), has evolved strategies to evade innate immunity and establish persistent infection. However, the mechanisms by which M. tuberculosis reprograms human macrophage metabolism remain incompletely defined. Tuberculous pleural effusion (TB-PE), a common extrapulmonary manifestation that frequently coexists with pulmonary TB, offers a unique, clinically relevant immunometabolic window into the TB microenvironment. Here, using patient-derived TB-PE samples, we demonstrate that this microenvironment induces a metabolic state in human macrophages that compromises their antimicrobial function. Lipidomic analysis identified an enrichment of the specialized pro-resolving mediator Resolvin D5 (RvD5), which signals through GPR32 to suppress macrophage microbicidal activity. The acellular fraction of TB-PE was sufficient to induce RvD5 secretion by monocytes, correlating with increased expression of RvD5 biosynthetic enzymes in pleural monocytes from TB patients. Mechanistically, RvD5-GPR32 signaling inhibited glycolysis without promoting oxidative phosphorylation, reducing HIF-1 activity and impairing intracellular M. tuberculosis control. HIF-1 stabilization restored antimicrobial function. These findings uncover the RvD5-GPR32-HIF-1 axis as a mechanism of metabolic immune suppression and a potential target for host-directed TB therapy. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/663524v3_ufig1.gif" ALT="Figure 1"> View larger version (68K): org.highwire.dtl.DTLVardef@64feceorg.highwire.dtl.DTLVardef@948ab0org.highwire.dtl.DTLVardef@1d387forg.highwire.dtl.DTLVardef@682f72_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

Distinct metabolic profiles of circulating plasmacytoid dendritic cells in systemic sclerosis patients stratified by clinical phenotypes

BackgroundPlasmacytoid dendritic cells (pDCs) play a key role in systemic sclerosis (SSc) pathophysiology. However, despite the recognised importance of metabolic reprogramming for pDC function, their metabolic profile in SSc remains to be elucidated. Thus, our study aimed to investigate the role of pDC metabolism in SSc. MethodsPeripheral blood mononuclear cells (PBMCs) were isolated from the blood of healthy donors and SSc patients. SCENITH, a single-cell flow cytometry-based method, was applied to infer the metabolic profile of circulating pDCs from patients with SSc. pDCs (CD304+ Lin-) at steady-state or stimulated with CpG A were analysed. Toll-like receptor (TLR)9 activation was confirmed by ribosomal protein S6 phosphorylation. ResultsCirculating pDCs from 10 healthy donors and 14 SSc patients were analysed. pDCs from anti-centromere antibody-positive (ACA+) patients displayed higher mitochondrial dependence and lower glycolytic capacity than those from anti-topoisomerase I antibody- positive (ATA+) patients. Furthermore, cells from both ACA+ patients and limited cutaneous SSc (lcSSc) patients showed a stronger response towards TLR9 activation than cells from ATA+, anti-RNA polymerase III antibody-positive (ARA+) or diffuse cutaneous SSc (dcSSc) patients. ConclusionsOur results show that pDCs from ACA+ patients rely more on oxidative phosphorylation (OXPHOS) and are more responsive to external stimuli, suggesting that pDCs from ATA+ patients may be more activated or exhausted. These findings point for the possible contribution of pDC metabolism to SSc clinical course, unveiling new potential targets for therapeutic approaches in SSc.

immunology↗

ZENITH: A flow cytometry based method for functional profiling energy metabolism with single cell resolution

Energetic metabolism reprogramming is critical for cancer and immune responses. Current methods to functionally profile the global metabolic capacities and dependencies of cells are performed in bulk. We designed a simple method for complex metabolic profiling called SCENITH, for Single Cell ENergetIc metabolism by profilIng Translation inHibition. SCENITH allows for the study of metabolic responses in multiple cell types in parallel by flow cytometry. SCENITH is designed to perform metabolic studies ex vivo, particularly for rare cells in whole blood samples, avoiding metabolic biases introduced by culture media. We analyzed myeloid cells in solid tumors from patients and identified variable metabolic profiles, in ways that are not linked to their lineage nor their activation phenotype. SCENITH ability to reveal global metabolic functions and determine complex and linked immune-phenotypes in rare cell subpopulations will contribute to the information needed for evaluating therapeutic responses or patient stratification.

immunology↗