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Zuo, M.

Publications and source records attributed to Zuo, M..

6 recordsLinked to original sources

KRAS-driven metabolic reprogramming of enhanced MFSD2A-mediated lysophosphatidylcholine scavenging promotes survival and progression of pancreatic ductal adenocarcinoma

Oncogenic KRAS drives lipid reprogramming in pancreatic ductal adenocarcinoma (PDAC) to promote disease progression, and these changes are manifest in circulation. Using mass spectrometry, we performed lipidomic analyses on plasmas from a cohort of 93 newly-diagnosed resectable PDAC cases, 43 patients with chronic pancreatitis, and 93 age- and sex-matched healthy controls, the results of which revealed pronounced reductions in circulating lysophosphatidylcholines (LysoPC) as a prominent feature associated with PDAC. Using stable-isotope resolved lipidomics, we further found that PDAC cells exhibit a lipid scavenging phenotype characterized by preferential uptake of extracellular unsaturated LysoPCs to sustain pro-growth signals. Restricting bioavailability of extracellular unsaturated LysoPCs shifted the metabolic phenotype of PDAC cells towards enhanced de novo lipogenesis and autophagy, which was accompanied by suppression of AKT signaling activities and increased susceptibility to apoptosis. Using bulk, single-cell, and spatial transcriptomic datasets together with functional experiments, we identified oncogenic KRAS-mediated upregulation of major facilitator superfamily domain-containing protein 2a (MFSD2A) as a key mediator that facilitates extracellular uptake of LysoPCs in PDAC cells. Loss of MFSD2A expression mimicked LysoPC restriction and resulted in inhibition of AKT signaling and increased propensity of PDAC cells to undergo apoptosis in vitro and suppressed tumor growth in vivo. Therapeutic targeting of the KRAS-MFSD2A-LysoPC axis via repurposing of the synthetic alkyl-lysophospholipid edelfosine promoted potent anti-cancer effects in vitro that were mechanistically attributed to reduced extracellular uptake of LysoPCs, and attenuation of AKT signaling. Collectively, our findings describe a previously unrecognized onco-metabolic program of enhanced LysoPC scavenging mediated by MFSD2A that promotes PDAC progression and that is therapeutically targetable via repurposing edelfosine.

cancer biology↗

Dynamic alterations of dural and bone marrow B cells in an animal model of progressive multiple sclerosis

In multiple sclerosis (MS), the leptomeninges (LM) are populated with immune cell aggregates that correlate with disease progression. The impact of LM inflammation on the adjacent dura is largely unknown. Using a mouse model of MS that induces brain LM inflammation and age-dependent disease progression, we found that encephalitogenic T cells and B220high B cells accumulate substantially in the brain LM and parenchyma of both young and aged mice, while the adjacent dura remains relatively inert. We also observed a population of anti-CD20 resistant B220low B cells in the dura and bone marrow that virtually disappear at disease onset and accumulate in the brain of young mice concomitant with disease remission. In contrast, aged mice show a paucity of brain-resident B220low B cells at the expense of class-switched B220high B cells concomitant with severe, chronic disease. In summary, dynamic changes in brain, LM and dural B cells are associated with age-dependent disease severity in an animal model of progressive MS. Short SummaryFlorescu et al. investigate the temporal accumulation of immune cells within distinct meningeal compartments in an animal model of progressive MS and uncover a population of anti-CD20 resistant dural B cells that remain in the brain parenchyma at disease remission.

immunology↗

Mining for microbial metabolites associated with disease progression in an age-dependent model of experimental autoimmune encephalomyelitis

Age is a risk factor for the neurological decline and physical disability that characterize progressive multiple sclerosis (MS). The intestinal microbiota and the bioactive compounds it produces can influence aging, immunity, and the central nervous system (CNS). Here, we use an experimental autoimmune encephalomyelitis (EAE) model that mimics features of progressive MS in aged, but not young, mice to address the intersection of age and the microbiota on EAE outcomes. Although the microbiota of SJL/J mice aged under controlled laboratory conditions does not promote an aged non-remitting EAE phenotype, young mice harboring heterochronic human fecal microbiota transplants (hFMT) developed a range of EAE phenotypes. Metabolomic profiling of mice colonized with an aged hFMT that promoted non-remitting EAE indicated a severe reduction in circulating levels of the microbiota-derived tryptophan metabolite indole 3-propionic acid (IPA). IPA-supplementation enforced remission in mice colonized with the non-remitting hFMT, demonstrating the utility of this in vivo pipeline for discovering metabolites associated with progressive MS-like disease. SummaryThe microbiota is a critical determinant of disease susceptibility in mouse models of MS. Here, Pu & Fettig et al. demonstrate that disease outcomes (remitting or non-remitting) are microbiota-responsive, and describe an in vivo pipeline that can be mined for microbial metabolites with therapeutic potential for progressive MS.

immunology↗

Vesicle-mediated mitochondrial clearance underlies an actionable metabolic vulnerability in triple-negative breast cancer

Selective autophagy of mitochondria is known to promote survival and progression of cancer cells in various malignancies including triple-negative breast cancer (TNBC). Here, we aimed to identify the essential metabolic adaptations that support mitochondrial quality control with the goal to uncover actionable metabolic vulnerabilities with therapeutic potential. Using an integrated approach of proteomics and untargeted and stable-isotope resolved metabolomics, coupled with functional experimental analyses, we define an alternative mechanism to mitophagy enabled by an onco-metabolic program of heightened extracellular sphingomyelin salvaging in TNBC that facilitates extracellular vesicle (EV)-mediated intracellular clearance of mitochondrial damage. Targeting of the cancer cell sphingolipid onco-metabolic pathway via repurposing of eliglustat, a selective small molecule inhibitor of glucosylceramide synthase (UGCG), resulted in ceramide-induced lethal mitophagy and attenuated tumor growth and prolonged overall survival at clinically achievable doses in an orthotopic syngeneic mouse model of TNBC. Our study defines a mechanism of aberrant sphingolipid metabolism that underlies an actionable metabolic vulnerability for anti-cancer treatment.

cancer biology↗

Glioma-associated fibroblasts promote glioblastoma resistance to temozolomide through CCL2-CCR2 paracrine signaling

Complicated tumor microenvironment contributes mostly to chemoresistance in glioblastoma. Glioma-associated fibroblasts (GAFs) were recently identified as non-tumor stromal cells in the glioblastoma microenvironment, whereas their function in glioblastoma chemoresistance is unclear. Herein, we interrogated the correlation between GAFs and chemoresistance of glioblastoma by examining a series of patient-derived GAFs and glioblastoma organoids (GBOs), revealing that GAFs could promote temozolomide resistance in glioblastoma. Mechanistically, C-C motif chemokine ligand 2 (CCL2) secreted by GAFs selectively activated the ERK1/2 signaling in glioblastoma cells to potentiate temozolomide resistance. Pharmacologically disrupting the CCL2-CCR2 axis or MEK1/2-ERK1/2 pathway effectively improved the therapeutic efficacy of temozolomide in GBM cells and patient-derived GBOs, and both decreased phospho-ERK1/2 expression. Collectively, our results identified that targeting the GAF-dominated CCL2-ERK1/2 pathway may be an alternative strategy to alleviate the GAF-mediated chemoresistance of glioblastoma. SignificanceComprehensive interpretation of the mutual support between tumor microenvironment and cancer cells is demanded for glioma with poor response rates to chemotherapy. This study demonstrates that GAFs promote the temozolomide resistance of glioblastoma by secreting cytokine CCL2 to activate ERK1/2 pathway, which may serve as a potential druggable candidate. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/581575v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@167b955org.highwire.dtl.DTLVardef@b892bcorg.highwire.dtl.DTLVardef@1a9b082org.highwire.dtl.DTLVardef@18327a8_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphic abstract.C_FLOATNO Schematic illustration for GAFs mediated chemoresistance of GBMs and underlying mechanisms. We demonstrate that Glioma-associated Fibroblasts (GAFs) grow in gliomas by isolating and identifying a panel of patient-derived GAFs. CCL2 secreted by GAFs stimulates CCR2 in GBM cells, which promotes activation of the ERK1/2 expression to potentiate GBM chemoresistance. C_FIG

cancer biology↗

Age related susceptibility to grey matter demyelination and neurodegeneration is associated with meningeal neutrophil accumulation in an animal model of Multiple Sclerosis

People living with multiple sclerosis (MS) experience episodic central nervous system (CNS) white matter lesions instigated by autoreactive T cells. With age, MS patients show evidence of grey matter demyelination and experience devastating non-remitting symptomology. What drives progression is unclear and has been hampered by the lack of suitable animal models. Here we show that passive experimental autoimmune encephalomyelitis (EAE) induced by an adoptive transfer of young Th17 cells induces a non-remitting clinical phenotype that is associated with persistent leptomeningeal inflammation and cortical pathology in old, but not young SJL/J mice. While the quantity and quality of T cells did not differ in the brains of old vs young EAE mice, an increase in neutrophils and a decrease in B cells was observed in the brains of old mice. Neutrophils were also found in the leptomeninges of a subset of progressive MS patient brains that showed evidence of leptomeningeal inflammation and subpial cortical demyelination. Taken together, our data show that while Th17 cells initiate CNS inflammation, subsequent clinical symptoms and grey matter pathology are dictated by age and associated with other immune cells such as neutrophils.

immunology↗