Rapidly growing tumors often experience hypoxia and nutrient (e.g., glucose) deficiency because of poor vascularization. Tumor cells respond to the cytotoxic effects of such stresses by inducing molecular adaptations that promote clonal selection of a more malignant tumor-initiating cell phenotype, especially in the innermost tumor regions. Here, we report a regulatory mechanism involving fucosylation by which glucose restriction promotes cancer stemness to drive drug resistance and tumor recurrence. Using hepatocellular carcinoma (HCC) as a model, we showed that restricted glucose availability enhanced the PERK-eIF2α-ATF4 signaling axis to drive fucosyltransferase-1 (FUT1) transcription via direct binding of ATF4 to the FUT1 promoter. FUT1 overexpression is a poor prognostic indicator for HCC. FUT1 inhibition could mitigate tumor initiation, self-renewal and drug resistance. Mechanistically, we demonstrated that CD147, ICAM-1, EGFR and EPHA2 are glycoprotein targets of FUT1, where such fucosylation would consequently converge on deregulated AKT-mTOR-4EBP1 signaling to drive cancer stemness. Treatment with an α-(1,2)-fucosylation inhibitor sensitized HCC tumors to sorafenib, a first-line molecular targeted drug used for advanced HCC patients, and reduced the tumor-initiating subset. FUT1 overexpression and/or CD147, ICAM-1, EGFR and EPHA2 fucosylation may be good prognostic markers and therapeutic targets for cancer patients.
Jane H.C. Loong, Tin-Lok Wong, Man Tong, Rakesh Sharma, Lei Zhou, Kai-Yu Ng, Hua-Jian Yu, Chi Han Li, Kwan Man, Chung-Mau Lo, Xin-Yuan Guan, Terence K. Lee, Jing-Ping Yun, Stephanie Kwai Yee Ma
The ability to adapt to low-nutrient microenvironments is essential for tumor-cell survival and progression in solid cancers, such as colorectal carcinoma (CRC). Signaling by the NF-κB transcription-factor pathway associates with advanced disease stages and shorter survival in CRC patients. NF-κB has been shown to drive tumor-promoting inflammation, cancer-cell survival and intestinal epithelial cell (IEC) dedifferentiation in mouse models of CRC. However, whether NF-κB affects the metabolic adaptations that fuel aggressive disease in CRC patients is unknown. Here, we identified carboxylesterase 1 (CES1) as an essential NF-κB-regulated lipase linking obesity-associated inflammation with fat metabolism and adaptation to energy stress in aggressive CRC. CES1 promoted CRC-cell survival via cell-autonomous mechanisms that fuel fatty-acid oxidation (FAO) and prevent the toxic build-up of triacylglycerols. We found that elevated CES1 expression correlated with worse outcomes in overweight CRC patients. Accordingly, NF-κB drove CES1 expression in CRC consensus molecular subtype (CMS)4, associated with obesity, stemness and inflammation. CES1 was also upregulated by gene amplifications of its transcriptional regulator, HNF4A, in CMS2 tumors, reinforcing its clinical relevance as a driver of CRC. This subtype-based distribution and unfavourable prognostic correlation distinguished CES1 from other intracellular triacylglycerol lipases and suggest CES1 could provide a route to treat aggressive CRC.
Daria Capece, Daniel D'Andrea, Federica Begalli, Laura Goracci, Laura Tornatore, James L. Alexander, Alessandra Di Veroli, Shi-Chi Leow, Thamil S. Vaiyapuri, James K. Ellis, Daniela Verzella, Jason Bennett, Luca Savino, Yue Ma, James S. McKenzie, Maria Luisa Doria, Sam E. Mason, Kern Rei Chng, Hector C. Keun, Gary Frost, Vinay Tergaonkar, Katarzyna Broniowska, Walter Stunkel, Zoltan Takats, James M. Kinross, Gabriele Cruciani, Guido Franzoso
Charcot-Marie-Tooth disease type 4J (CMT4J) is caused by recessive, loss-of-function mutations in FIG4, encoding a phosphoinositol(3,5)P2-phosphatase. CMT4J patients have both neuron loss and demyelination in the peripheral nervous system, with vacuolization indicative of endosome/lysosome trafficking defects. Although the disease is highly variable, the onset is often in childhood and FIG4 mutations can dramatically shorten lifespan. There is currently no treatment for CMT4J. Here we present the results of preclinical studies testing a gene therapy approach to restore FIG4 expression. A mouse model of CMT4J, the Fig4-pale tremor (plt) allele, was dosed with a single-stranded AAV9 to deliver a codon-optimized human FIG4 sequence. Untreated, Fig4plt/plt mice have a median survival of approximately 5 weeks. When treated with the AAV9-FIG4 vector at postnatal day 1 or 4, mice survived at least one year, with largely normal gross motor performance and little sign of neuropathy by neurophysiological or histopathological evaluation. When treated at postnatal day 7 or 11, life span was still significantly prolonged and peripheral nerve function was improved, but rescue was less complete. No unanticipated adverse effects were observed. Therefore, AAV9-mediated delivery of FIG4 is a well-tolerated and efficacious strategy in a mouse model of CMT4J.
Maximiliano Presa, Rachel M. Bailey, Crystal Davis, Tara Murphy, Jenn Cook, Randy Walls, Hannah Wilpan, Laurent Bogdanik, Guy M. Lenk, Robert W. Burgess, Steven J. Gray, Cathleen Lutz
Dysregulated protein degradative pathways are increasingly recognized as mediators of human disease. This mechanism may have particular relevance to desmosomal proteins that play critical structural roles in both tissue architecture and cell-cell communication as destabilization/breakdown of the desmosomal proteome is a hallmark of genetic-based desmosomal-targeted diseases, such as the cardiac disease, arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). However, no information exists on whether there are resident proteins that regulate desmosomal proteome homeostasis. Here we uncovered a cardiac COP9 desmosomal resident protein complex, composed of subunit 6 of the COP9 signalosome (CSN6), that enzymatically restricted neddylation and targeted desmosomal proteome degradation. CSN6 binding, localization, levels and function were impacted in hearts of classic mouse and human models of ARVD/C impacted by desmosomal loss and mutations, respectively. Loss of desmosomal proteome degradation control due to CSN6 loss and human desmosomal mutations destabilizing CSN6 were also sufficient to trigger ARVD/C in mice. We identified a desmosomal resident regulatory complex that restricted desmosomal proteome degradation and disease.
Yan Liang, Robert C. Lyon, Jason Pellman, William H. Bradford, Stephan Lange, Julius Bogomolovas, Nancy D. Dalton, Yusu Gu, Marcus Bobar, Mong-Hong Lee, Tomoo Iwakuma, Vishal Nigam, Angeliki Asimaki, Melvin Scheinman, Kirk L. Peterson, Farah Sheikh
Synaptic plasticity is identified as innate to hypothalamic feeding circuits in their adaptation to the changing metabolic milieu in control of feeding and obesity. However, less is known about the regulatory principles of the dynamic changes of AgRP perikarya, a crucial region of the neuron gating excitation, and hence, feeding. Here we show that AgRP neurons activated either by food deprivation, ghrelin or chemogenetics decreased their own inhibitory tone while triggering mitochondrial adaptations in neighboring astrocytes. We found that it was the inhibitory neurotransmitter, GABA, released by AgRP neurons that evoked this astrocytic response, which in turn, resulted in increased glial ensheetment of AgRP perikaryal by glial processes and increased excitability of AgRP neurons. We also identified that astrocyte-derived prostaglandin E2 directly activated, via EP2 receptors, AgRP neurons. Taken together, these observations unmasked a feedforward, self-exciting loop in AgRP neuronal control mediated by astrocytes, a mechanism directly relevant for hunger, feeding and overfeeding.
Luis Varela, Bernardo Stutz, Jae Eun Song, Jae Geun Kim, Zhong-Wu Liu, Xiao-Bing Gao, Tamas L. Horvath
T cell immunity is essential for the control of tuberculosis (TB), an important disease of the lung, and is generally studied in humans using peripheral blood cells. Mounting evidence, however, indicates that tissue resident memory T cells (Trm) are superior at controlling many pathogens, including Mycobacterium tuberculosis (Mtb), and can be quite different from those in circulation. Using freshly resected lung tissue, from individuals with active or previous TB, we identified distinct CD4 and CD8 Trm-like clusters within TB diseased lung tissue that were functional and enriched for IL-17 producing cells. Mtb-specific CD4 T cells producing TNF-α, IL-2 and IL-17 were highly expanded in the lung compared to matched blood samples, in which IL-17+ cells were largely absent. Strikingly, the frequency of Mtb-specific lung T cells making IL-17, but not other cytokines, inversely correlated with the plasma IL-1β levels, suggesting a potential link with disease severity. Using a human granuloma model, we showed the addition of either exogenous IL-17 or IL-2 enhanced immune control of Mtb and was associated with increased NO production. Taken together, these data support an important role for Mtb-specific Trm-like IL-17 producing cells in the immune control of Mtb in the human lung.
Paul Ogongo, Liku B. Tezera, Amanda Ardain, Shepherd Nhamoyebonde, Duran Ramsuran, Alveera Singh, Abigail Ngoepe, Farina Karim, Taryn Naidoo, Khadija Khan, Kaylesh J. Dullabh, Michael Fehlings, Boon Heng Lee, Alessandra Nardin, Cecilia S. Lindestam Arlehamn, Alessandro Sette, Samuel M. Behar, Adrie J.C. Steyn, Rajhmun Madansein, Henrik N. Kløverpris, Paul T. Elkington, Alasdair Leslie
Stimulation of TAM (TYRO3, AXL and MERTK) Receptor Tyrosine Kinases promotes tumor progression through numerous cellular mechanisms. TAM cognate ligands GAS6 and PROS1 (for TYRO3 and MERTK) are secreted by host immune cells, an interaction which may support tumor progression. Here we reveal an unexpected anti-metastatic role for myeloid-derived PROS1, directly suppressing the metastatic potential of lung and breast tumor models. Pros1 deletion in myeloid cells led to increased lung metastasis, independent of primary tumor infiltration. PROS1-cKO BMDMs led to elevated TNFα, IL-6, Nos2 and IL-10 via modulation of the Socs3-NFκB pathway. Conditioned medium from cKO BMDMs enhanced EMT, ERK, AKT and STAT3 activation within tumor cells, and promoted IL-10 dependent invasion and survival. Macrophages isolated from metastatic lungs modulated T cell proliferation and function, as well as expression of costimulatory molecules on dendritic cells in a PROS1-dependent manner. Inhibition of MERTK kinase activity blocked PROS1-mediated suppression of TNFα and IL-6, but not of IL-10. Overall, using lung and breast cancer models, we identify the PROS1-MERTK axis within BMDMs as a potent regulator of adaptive immune responses with a potential to suppress metastatic seeding, and reveal IL-10 regulation by PROS1 to deviate from that of TNFα and IL-6.
Avi Maimon, Victor Levi-Yahid, Kerem Ben-Meir, Amit Halpern, Ziv Talmi, Shivam Priya, Gabriel Mizraji, Shani Mistriel-Zerbib, Michael Berger, Michal Baniyash, Sonja Loges, Tal Burstyn-Cohen
Opioid use disorder (OUD) has become a leading cause of death in the US, yet current therapeutic strategies remain highly inadequate. To identify novel potential treatments for OUD, we screened a targeted selection of over 100 drugs using a recently developed opioid self-administration assay in zebrafish. This paradigm showed that finasteride, a steroidogenesis inhibitor approved for the treatment of benign prostatic hyperplasia and androgenetic alopecia, reduced self-administration of multiple opioids without affecting locomotion or feeding behavior. These findings were confirmed in rats; furthermore, finasteride reduced the physical signs associated with opioid withdrawal. In rat models of neuropathic pain, finasteride did not alter the antinociceptive effect of opioids and reduced withdrawal-induced hyperalgesia. Steroidomic analyses of the brains of fish treated with finasteride revealed a significant increase in dehydroepiandrosterone sulfate (DHEAS). Treatment with precursors of DHEAS reduced opioid self-administration in zebrafish in a fashion akin to the effects of finasteride. These results highlight the importance of steroidogenic pathways as a rich source of therapeutic targets for OUD and point to the potential of finasteride as a new treatment option for this disorder.
Gabriel D. Bosse, Roberto Cadeddu, Gabriele Floris, Ryan D. Farero, Eva Vigato, Suhjung J. Lee, Tejia Zhang, Nilesh W. Gaikwad, Kristen A. Keefe, Paul E.M. Phillips, Marco Bortolato, Randall T. Peterson
Multisystem Inflammatory Syndrome in Children (MIS-C) is a rare but deadly new disease in children that rapidly progresses to hyperinflammation, shock, and can lead to multiple organ failure if unrecognized. It has been found to be temporally associated with the COVID-19 pandemic and is often associated with SARS-CoV-2 exposure in children. In this issue of the JCI, Porritt, Paschold, and Rivas et al. identify restricted T cell receptor (TCR) β-chain variable domain (Vβ) usage in patients with severe MIS-C indicating a potential role for SARS-CoV-2 as a superantigen. These findings suggest that a blood test that determines the presence of specific TCR beta variable gene segments (TRBV) may identify patients at risk for severe MIS-C.
Theodore Kouo, Worarat Chaisawangwong
Drugs targeting host proteins can act prophylactically to reduce viral burden early in disease and limit morbidity, even with antivirals and vaccination. Transmembrane serine protease 2 (TMPRSS2) is a human protease required for SARS-CoV-2 viral entry and may represent such a target. We hypothesized that drugs selected from proteins related by their tertiary structure, rather than their primary structure, were likely to interact with TMPRSS2. We created a structure-based phylogenetic computational tool named 3DPhyloFold to systematically identify structurally similar serine proteases with known therapeutic inhibitors and demonstrated effective inhibition of SARS-CoV-2 infection in vitro and in vivo. Several candidate compounds, Avoralstat, PCI-27483, Antipain, and Soybean-Trypsin-Inhibitor, inhibited TMPRSS2 in biochemical and cell infection assays. Avoralstat, a clinically tested Kallikrein-related B1 inhibitor, inhibited SARS-CoV-2 entry and replication in human airway epithelial cells. In an in vivo proof of principle, Avoralstat significantly reduced lung tissue titers and mitigated weight-loss when administered prophylactically to SARS-CoV-2 susceptible mice indicating its potential to be repositioned for COVID-19 prophylaxis in humans.
Young Joo Sun, Gabriel Velez, Dylan E. Parsons, Kun Li, Miguel E. Ortiz, Shaunik Sharma, Paul B. McCray Jr., Alexander G. Bassuk, Vinit B. Mahajan
Background. Recent studies have reported T cell immunity to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in unexposed donors, possibly due to cross-recognition by T-cells specific for common cold coronaviruses (CCCs). True T-cell cross-reactivity, defined as the recognition by a single TCR of more than one distinct peptide-MHC ligand, has never been shown in the context of SARS-CoV-2. Methods. We used the ViraFEST platform to identify T cell responses cross-reactive for the spike (S) glycoproteins of SARS-CoV-2 and CCCs at the T cell receptor (TCR) clonotype level in convalescent COVID-19 patients (CCPs) and SARS-CoV-2-unexposed donors. Confirmation of SARS-CoV-2/CCC cross-reactivity and assessments of functional avidity were performed using a TCR cloning and transfection system. Results. Memory CD4+ T-cell clonotypes that cross-recognized the S proteins of SARS-CoV-2 and at least one other CCC were detected in 65% of CCPs and unexposed donors. Several of these TCRs were shared among multiple donors. Cross-reactive T-cells demonstrated significantly impaired SARS-CoV-2-specific proliferation in vitro relative to mono-specific CD4+ T-cells, which was consistent with lower functional avidity of their TCRs for SARS CoV-2 relative to CCC. Conclusions. For the first time, our data confirm the existence of unique memory CD4+ T cell clonotypes cross-recognizing SARS-CoV-2 and CCCs. The lower avidity of cross-reactive TCRs for SARS-CoV-2 may be the result of antigenic imprinting, such that pre-existing CCC-specific memory T cells have reduced expansive capacity upon SARS-CoV-2 infection. Further studies are needed to determine how these cross-reactive T-cell responses impact clinical outcomes in COVID-19 patients.
Arbor G. Dykema, Boyang Zhang, Bezawit A. Woldemeskel, Caroline C. Garliss, Laurene S. Cheung, Dilshad Choudhury, Jiajia Zhang, Luis Aparicio, Sadhana Bom, Rufiaat Rashid, Justina X. Caushi, Emily Han-Chung Hsiue, Katherine Cascino, Elizabeth A. Thompson, Abena K. Kwaa, Dipika Singh, Sampriti Thapa, Alvaro A. Ordonez, Andrew Pekosz, Franco R. D'Alessio, Jonathan D. Powell, Srinivasan Yegnasubramanian, Shibin Zhou, Drew M. Pardoll, Hongkai Ji, Andrea L. Cox, Joel N. Blankson, Kellie N. Smith
A complete carcinogen, Ultraviolet B radiation (290-320 nm; UVB), is the major cause of skin cancer. UVB-induced systemic immunosuppression that contributes to photocarcinogenesis is due to the glycerophosphocholine-derived lipid mediator Platelet-activating factor. A major question in photobiology is how UVB radiation, which only absorbs appreciably in the epidermal layers of skin, can generate systemic effects. UVB exposure and PAF Receptor (PAFR) activation in keratinocytes induce large amounts of microvesicle particle (extracellular vesicles 100-1000nm; MVP) release. MVPs released from skin keratinocytes in vitro in response to UVB (UVB-MVP) are dependent upon the keratinocyte PAFR. The present studies used both pharmacologic and genetic approaches in cells and mice to determine that both the PAFR and enzyme acid sphingomyelinase (aSMase) were necessary for UVB-MVP generation. Discovery that the calcium-sensing receptor is a keratinocyte-selective MVP marker allowed us to determine that UVB-MVP leaving the keratinocyte can be found systemically in mice and in human subjects following UVB. Moreover, UVB-MVP contain bioactive contents including PAFR agonists which allow them to serve as effectors for UVB downstream effects, in particular UVB-mediated systemic immunosuppression.
Langni Liu, Azeezat A. Awoyemi, Katherine E. Fahy, Pariksha Thapa, Christina Borchers, Benita Y. Wu, Cameron L. McGlone, Benjamin Schmeusser, Zafer Sattouf, Craig A. Rohan, Amy R. Williams, Elizabeth E. Cates, Christina Knisely, Lisa E. Kelly, Ji C. Bihl, David R. Cool, Ravi P. Sahu, Jinju Wang, Yanfang Chen, Christine M. Rapp, Michael G. Kemp, R. Michael Johnson, Jeffrey B. Travers
One of the primary mechanisms of tumor cell immune evasion is the loss of antigenicity, which arises due to lack of immunogenic tumor antigens as well as dysregulation of the antigen processing machinery. In a screen for small-molecule compounds from herbal medicine that potentiate T cell-mediated cytotoxicity, we identified atractylenolide I (ATT-I) that significantly promotes tumor antigen presentation of both human and mouse colorectal cancer (CRC) cells and thereby enhances the cytotoxic response of CD8+ T cells. Cellular thermal shift assay (CETSA) with multiplexed quantitative mass spectrometry identified the proteasome 26S subunit non-ATPase 4 (PSMD4), an essential component of the immunoproteasome complex, as a primary target protein of ATT-I. Binding of ATT-I with PSMD4 augments the antigen-processing activity of immunoproteasome, leading to enhanced major histocompatibility class I (MHC-I)-mediated antigen presentation on cancer cells. In syngeneic mouse CRC models and human patient-derived CRC organoid models, ATT-I treatment promotes the cytotoxicity of CD8+ T cells and thus profoundly enhances the efficacy of immune checkpoint blockade therapy. Collectively, we show here that targeting the function of immunoproteasome with ATT-I promotes tumor antigen presentation, empowers T-cell cytotoxicity, and thus elevates the tumor response to immunotherapy.
Hanchen Xu, Kevin Van der Jeught, Zhuolong Zhou, Lu Zhang, Tao Yu, Yifan Sun, Yujing Li, Changlin Wan, Kaman So, Degang Liu, Michael Frieden, Yuanzhang Fang, Amber L. Mosley, Xiaoming He, Xinna Zhang, George E. Sandusky, Yunlong Liu, Samy O. Meroueh, Chi Zhang, Aruna B. Wijeratne, Cheng Huang, Guang Ji, Xiongbin Lu
BACKGROUND. Recently the α1 adrenergic receptor antagonist terazosin was shown to activate PGK1, a possible target for the mitochondrial deficits in Parkinson disease related to its function as the initial enzyme in ATP synthesis during glycolysis. An epidemiologic study of terazosin users showed a lower incidence of Parkinson disease when compared to users of tamsulosin, an α1 adrenergic receptor antagonist of a different class that does not activate PGK1. However, prior research on tamsulosin has suggested that it may in fact potentiate neurodegeneration, raising the question of whether it is an appropriate control group. METHODS. To address this question, we undertook an epidemiological study on Parkinson disease occurrence rate in 113,450 individuals from the U.S.A. with > 5 years of follow-up. Patients were classified as tamsulosin users (n = 45,380), terazosin/alfuzosin/doxazosin users (n = 22,690) or controls matched on age, gender and Charlson Comorbidity Index score (n = 45,380). RESULTS. Incidence of Parkinson disease in tamsulosin users was 1.53%, which was significantly higher than that in both terazosin/alfuzosin/doxazosin users (1.10%; p<0.0001) and matched controls (1.01%; p < 0.0001). Terazosin/alfuzosin/doxazosin users did not differ in Parkinson disease risk from matched controls (p = 0.29). CONCLUSION. These results suggest that zosins may not confer a protective effect against Parkinson disease, but rather that tamsulosin may in some way potentiate Parkinson disease progression. FUNDING. This work was supported by Cerevel Therapeutics.
Rahul Sasane, Amy Bartels, Michelle Field, Maria I. Sierra, Sridhar Duvvuri, David L. Gray, Sokhom S. Pin, John J. Renger, David J. Stone
Recent studies have shown T cell cross-recognition of SARS-CoV-2 and common cold coronavirus spike proteins. However, the effect of SARS-CoV-2 vaccines on T cell responses to common cold coronaviruses remain unknown. In this study, we analyzed CD4+ T cell responses to spike peptides from SARS-CoV-2 and 3 common cold coronaviruses (HCoV-229E, HCoV-NL63, and HCoV-OC43) before and after study participants received Pfizer-BioNTech (BNT162b2) or Moderna (mRNA-1273) mRNA-based COVID-19 vaccines. Vaccine recipients made broad T cell responses to the SARS-CoV-2 spike protein and we identified 23 distinct targeted peptides in 9 participants including one peptide that was targeted by 6 individuals. Only 4 out of these 23 targeted peptides would potentially be affected by mutations in the UK (B.1.1.7) and South African (B.1.351) variants and CD4+ T cells from vaccine recipients recognized the 2 variant spike proteins as effectively as the spike protein from the ancestral virus. Interestingly, we saw a 3-fold increase in the CD4+ T cell responses to HCoV-NL63 spike peptides post-vaccination. Our results suggest that T cell responses elicited or enhanced by SARS-CoV-2 mRNA vaccines may be able to control SARS-CoV-2 variants and lead to cross-protection from some endemic coronaviruses.
Bezawit A. Woldemeskel, Caroline C. Garliss, Joel N. Blankson
Inhibitors of calcineurin phosphatase activity (CNIs) such as cyclosporin A (CsA) are widely used to treat tissue transplant rejection and acute graft-versus-host disease (aGVHD), for which inhibition of NFAT-dependent gene expression is the mechanistic paradigm. We recently reported that CNIs inhibit TCR-proximal signaling by preventing calcineurin-mediated dephosphorylation of LckS59, an inhibitory modification, raising the possibility of another mechanism by which CNIs suppress immune responses. Here we utilized T cells from mice that express LckS59A, which cannot accept a phosphate at residue 59, to initiate aGVHD. Although CsA inhibited NFAT-dependent gene upregulation in allo-aggressive T cells expressing either LckWT or LckS59A, it was ineffective in treating disease when the T cells expressed LckS59A. Two important NFAT-independent T cell functions were found to be CsA-resistant in LckS59A T cells: upregulation of the cytolytic protein perforin in tissue-infiltrating CD8+ T cells and antigen-specific T:DC (dendritic cell) adhesion and clustering in lymph nodes. These results demonstrate that effective treatment of aGVHD by CsA requires NFAT-independent inhibition of TCR signaling. Given that NFATs are widely expressed and off-target effects are a major limitation in CNI use, it is possible that targeting TCR-associated calcineurin directly may provide effective therapies with less toxicity.
Shizuka Otsuka, Nicolas Melis, Matthias M. Gaida, Debjani Dutta, Roberto Weigert, Jonathan D. Ashwell
Limiting dysfunctional neutrophilic inflammation whilst preserving effective immunity requires a better understanding of the processes that dictate neutrophil function in the tissues. Quantitative mass-spectrometry identified how inflammatory murine neutrophils regulated expression of cell surface receptors, signal transduction networks and metabolic machinery to shape neutrophil phenotypes in response to hypoxia. Through the tracing of labelled amino acids into metabolic enzymes, pro-inflammatory mediators and granule proteins we demonstrated that ongoing protein synthesis shapes the neutrophil proteome. To maintain energy supplies in the tissues, neutrophils consumed extracellular proteins to fuel central carbon metabolism. The physiological stresses of hypoxia and hypoglycaemia, characteristic of inflamed tissues, promoted this extra-cellular protein scavenging with activation of the lysosomal compartment further driving exploitation of the protein rich inflammatory milieu. This study provides a comprehensive map of neutrophil proteomes, analysis of which has led to the identification of active catabolic and anabolic pathways which enable neutrophils to sustain synthetic and effector functions in the tissues.
Emily R. Watts, Andrew J.M. Howden, Tyler Morrison, Pranvera Sadiku, Jens L. Hukelmann, Alex von Kriegsheim, Bart Ghesquière, Fiona Murphy, Ananda S. Mirchandani, Duncan C. Humphries, Robert Grecian, Eilise M. Ryan, Patricia Coelho, Giovanny Rodriguez-Blanco, Tracie M. Plant, Rebecca S. Dickinson, Andrew J. Finch, Wesley Vermaelen, Doreen A. Cantrell, Moira K.B. Whyte, Sarah R. Walmsley
Anemia in β-thalassemia is related to ineffective erythropoiesis and reduced red cell survival. Excess free heme and accumulation of unpaired α-globin chains impose substantial oxidative stress on β-thalassemic erythroblasts and erythrocytes, impacting cell metabolism. We hypothesized that increased pyruvate kinase activity induced by mitapivat (AG-348) in the Hbbth3/+ mouse model for β-thalassemia would reduce chronic hemolysis and ineffective erythropoiesis through stimulation of red cell glycolytic metabolism. Oral mitapivat administration ameliorated ineffective erythropoiesis and anemia in Hbbth3/+ mice. Increased ATP, reduced reactive oxygen species production, and reduced markers of mitochondrial dysfunction associated with improved mitochondrial clearance suggested enhanced metabolism following mitapivat administration in β-thalassemia. The amelioration of responsiveness to erythropoietin resulted in reduced soluble erythroferrone, increased liver Hamp expression, and diminished liver iron overload. Mitapivat reduced duodenal Dmt1 expression potentially by activating the pyruvate kinase M2HIF2α axis, representing a mechanism additional to Hamp in controlling iron absorption and preventing β-thalassemia–related liver iron overload. In ex vivo studies on erythroid precursors from patients with β-thalassemia, mitapivat enhanced erythropoiesis, promoted erythroid maturation, and decreased apoptosis. Overall, pyruvate kinase activation as a treatment modality for β-thalassemia in preclinical model systems had multiple beneficial effects in the erythropoietic compartment and beyond, providing a strong scientific basis for further clinical trials.
Alessandro Matte, Enrica Federti, Charles Kung, Penelope A. Kosinski, Rohini Narayanaswamy, Roberta Russo, Giorgia Federico, Francesca Carlomagno, Maria Andrea Desbats, Leonardo Salviati, Christophe Leboeuf, Maria Teresa Valenti, Francesco Turrini, Anne Janin, Shaoxia Yu, Elisabetta Beneduce, Sebastien Ronseaux, Iana Iatcenko, Lenny Dang, Tomas Ganz, Chun-Ling Jung, Achille Iolascon, Carlo Brugnara, Lucia De Franceschi
The protein kinases IKK-epsilon and TBK1 are activated in liver and fat in mouse models of obesity. We have previously demonstrated that treatment with the IKK-epsilon/TBK1 inhibitor, amlexanox, produces weight loss and relieves insulin resistance in obese animals and patients. While amlexanox treatment caused a transient reduction in food intake, long-term weight loss was attributable to increased energy expenditure via FGF21-dependent beiging of WAT. Amlexanox increased FGF21 synthesis and secretion in several tissues. Interestingly, while hepatic secretion determined circulating levels, it was dispensable for regulating energy expenditure. In contrast, adipocyte-secreted FGF21 may have acted as an autocrine factor that leads to adipose tissue browning and weight loss in obese mice. Moreover, increased energy expenditure was an important determinant of improved insulin sensitivity by amlexanox. Conversely, the immediate reductions in fasting blood glucose observed with acute amlexanox treatment were mediated by suppression of hepatic glucose production via the activation of STAT3 by adipocyte-secreted IL-6. These findings demonstrate that amlexanox improved metabolic health via FGF21 action in adipocytes to increase energy expenditure via WAT beiging, and an endocrine role of adipocyte-derived IL-6 to decrease gluconeogenesis via hepatic STAT3 activation, thereby producing a coordinated improvement in metabolic parameters.
Shannon M. Reilly, Mohammad Abu-Odeh, Magdalene Ameka, Julia H. DeLuca, Meghan C. Naber, Benyamin Dadpey, Nima Ebadat, Andrew V. Gomez, Xiaoling Peng, BreAnne Poirier, Elyse Walk, Matthew J. Potthoff, Alan R. Saltiel
BACKGROUND. Current clinical management of patients with pulmonary nodules involves either repeated LDCT/CT scans or invasive procedures yet causes significant patient misclassification. An accurate non-invasive test is needed to identify malignant nodules and reduce unnecessary invasive tests. METHOD. We developed a diagnostic model based on targeted DNA methylation sequencing of 389 pulmonary nodule patients’ plasma samples, and then validated in 140 plasma samples independently. We tested the model in different stages and subtypes of pulmonary nodules. RESULTS. A 100-feature model was developed and validated for pulmonary nodule diagnosis: the model achieved a ROC-AUC of 0.843 on 140 independent validation samples with an accuracy of 0.800. The performance was well maintained in, 1) 6-20 mm size subgroup (N=100), with a sensitivity of 1.000 and adjusted NPV of 1.000 at 10% prevalence; 2) stage I malignancy (N=90), with a sensitivity of 0.971; 3) different nodule types - solid nodules (N=78) with a sensitivity of 1.000 and adjusted NPV of 1.000, part-solid nodules (N=75) with a sensitivity of 0.947 and adjusted NPV of 0.983, and ground-glass nodules (N=67) with a sensitivity of 0.964 and adjusted NPV of 0.989 at 10% prevalence. This methylation test, called PulmoSeek, outperformed PET-CT and two clinical prediction models (Mayo and Veterans Affairs) in discriminating malignant pulmonary nodules from benign ones. CONCLUSION. This study suggests that the blood-based DNA methylation model may provide a better test for classifying pulmonary nodules, which could help facilitate the accurate diagnosis of early-stage lung cancer from pulmonary nodule patients and guide clinical decisions. FUNDING. The National Key Research and Development Program of China; Science and Technology Planning Project of Guangdong Province; The National Natural Science Foundation of China National.
Wenhua Liang, Zhiwei Chen, Caichen Li, Jun Liu, Jinsheng Tao, Xin Liu, Dezhi Zhao, Weiqiang Yin, Hanzhang Chen, Chao Cheng, Fenglei Yu, Chunfang Zhang, Lunxu Liu, Hui Tian, Kaican Cai, Xiang Liu, Zheng Wang, Ning Xu, Qing Dong, Liang Chen, Yue Yang, Xiuyi Zhi, Hui Li, Xixiang Tu, Xiangrui Cai, Zeyu Jiang, Hua Ji, Lili Mo, Jiaxuan Wang, Jian-Bing Fan, Jianxing He