Targeting aryl hydrocarbon receptor functionally restores tolerogenic dendritic cells derived from patients with multiple sclerosis

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Abstract

Multiple Sclerosis (MS) is a chronic disease characterized by dysregulated self-reactive immune responses that damage the neurons’ myelin sheath, leading to progressive disability. The primary therapeutic option, immunosuppressants, inhibits pathogenic anti-myelin responses but depresses the immune system. Antigen-specific monocyte-derived autologous tolerogenic dendritic cells (tolDCs) offer alternative therapeutic approaches to restore tolerance to auto-antigens without causing generalized immunosuppression. However, immune dysregulation in MS could impact the properties of the monocytes used as starting material for this cell therapy. Here, we characterized CD14+ monocytes, mature dendritic cells (mDCs) and Vitamin-D3-tolDCs (VitD3-tolDCs) from active, treatment-naive MS patients and healthy donors (HD). Using multi-omics, we identified a switch in these cell types towards proinflammatory features characterized by alterations in the AhR and NF-kB pathways. MS patient-derived VitD3-tolDCs showed reduced tolerogenic properties compared to those from HD, which were fully restored through direct AhR agonism and using in vivo or in vitro Dimethyl Fumarate (DMF) supplementation. Additionally, in the experimental autoimmune encephalomyelitis (EAE) mouse model, combined therapy of DMF and VitD3-tolDCs was more efficient than monotherapies in reducing the clinical score of mice. We propose that a combined therapy with DMF and VitD3-tolDCs offers enhanced therapeutic potential in treating MS.

Authors

Federico Fondelli, Jana Willemyns, Roger Domenech-Garcia, Maria José Mansilla, Gerard Godoy-Tena, Anna G. Ferreté-Bonastre, Alex Agúndez-Moreno, Silvia Presas-Rodriguez, Cristina Ramo-Tello, Esteban Ballestar, Eva Martínez-Cáceres

PAC1 constrains type II inflammation through promotion of CGRP signaling in ILC2s

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Abstract

Dysfunction of group II innate lymphoid cells (ILC2s) plays an important role in the development of type II inflammation-related diseases such as asthma and pulmonary fibrosis. Notably, neural signals are increasingly recognized as pivotal regulators of ILC2s. However, how ILC2s intrinsically modulate their responsiveness to these neural signals is still largely unknown. Here, using single-cell RNA sequencing, we found that the immune regulatory molecule PAC1 (phosphatase of activated cells 1) selectively promotes the signaling of neuropeptide CGRP (calcitonin gene-related peptide) in ILC2s through a cell-intrinsic manner. Genetic ablation of PAC1 in ILC2s substantially impaired the inhibitory effect of CGRP on proliferation and IL-13 secretion. PAC1 deficiency significantly exacerbated allergic airway inflammation induced by Alternaria alternata or papain in mice. Moreover, in human circulating ILC2s, the expression level of PAC1 was also significantly negatively correlated with the cell amount and the expression level of IL13. Mechanistically, PAC1 was necessary for ensuring the expression of CGRP-response genes by influencing chromatin accessibility. In summary, our study demonstrated that PAC1 is an important regulator of ILC2 responses and we proposed that PAC1 is a potential target for therapeutic interventions of type II inflammation-related diseases.

Authors

Yuan Jin, Bowen Liu, Qiuyu Li, Xiangyan Meng, Xiaowei Tang, Yan Jin, Yuxin Yin

Lactate supports Treg function and immune balance via MGAT1 effects on N-glycosylation in the mitochondria

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Abstract

Current research reports that lactate affects Treg metabolism, although the precise mechanism has only been partially elucidated. In this study, we presented evidence demonstrating that elevated lactate levels enhanced cell proliferation, suppressive capabilities, and oxidative phosphorylation (OXPHOS) in human Tregs. The expression levels of Monocarboxylate Transporters 1/2/4 (MCT1/2/4) regulate intracellular lactate concentration, thereby influencing the varying responses observed in naive Tregs and memory Tregs. Through mitochondrial isolation, sequencing, and analysis of human Tregs, we determined that Alpha-1,3-Mannosyl-Glycoprotein 2-Beta-N-Acetylglucosaminyltransferase (MGAT1) served as the pivotal driver initiating downstream N-glycosylation events involving progranulin (GRN) and hypoxia-upregulated 1 (HYOU1), consequently enhancing Treg OXPHOS. The mechanism by which MGAT1 was upregulated in mitochondria depended on elevated intracellular lactate that promoted the activation of XBP1s, which, in turn, supported MGAT1 transcription as well as the interaction of lactate with the translocase of the mitochondrial outer membrane 70 (TOM70) import receptor, facilitating MGAT1 translocation into mitochondria. Pre-treatment of Tregs with lactate reduced mortality in a xenogeneic graft-versus-host disease (GvHD) model. Together, these findings underscored the active regulatory role of lactate in human Treg metabolism through the upregulation of MGAT1 transcription and its facilitated translocation into the mitochondria.

Authors

Jinren Zhou, Jian Gu, Qufei Qian, Yigang Zhang, Tianning Huang, Xiangyu Li, Zhuoqun Liu, Qing Shao, Yuan Liang, Lei Qiao, Xiaozhang Xu, Qiuyang Chen, Zibo Xu, Yu Li, Ji Gao, Yufeng Pan, Yiming Wang, Roddy O'Connor, Keli L. Hippen, Ling Lu, Bruce R. Blazar

Postprandial metabolomics analysis reveals disordered serotonin metabolism in post-bariatric hypoglycemia

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Abstract

BACKGROUND. Bariatric surgery is a potent therapeutic approach for obesity and type 2 diabetes but can be complicated by post-bariatric hypoglycemia (PBH). PBH typically occurs 1 to 3 hours after meals, in association with exaggerated postprandial levels of incretins and insulin. METHODS. To identify mediators of disordered metabolism in PBH, we analyzed plasma metabolome in fasting state and 30 and 120 minutes after mixed meal in 3 groups: PBH (n = 13), asymptomatic post-RYGB (n = 10), and non-surgical controls (n = 8). RESULTS. In the fasting state, multiple tricarboxylic acid cycle intermediates and the ketone beta-hydroxybutyrate were increased by 30% to 80% in PBH vs. asymptomatic. Conversely, multiple amino acids (BCAA, tryptophan) and polyunsaturated lipids were reduced by 20% to 50% in PBH versus asymptomatic. Tryptophan-related metabolites, including kynurenate, xanthurenate, and serotonin, were reduced by 2- to 10-fold in PBH in fasting state. Postprandially, plasma serotonin was uniquely increased by 1.9-fold in PBH versus asymptomatic post-RYGB. In mice, serotonin administration lowered glucose and increased plasma insulin and GLP-1. Moreover, serotonin-induced hypoglycemia in mice was blocked by the nonspecific serotonin receptor antagonist cyproheptadine and the specific serotonin receptor 2 antagonist ketanserin. CONCLUSION. Together these data suggest that increased postprandial serotonin may contribute to the pathophysiology of PBH and provide a potential therapeutic target. FUNDING. NIH grant R01 DK121995, NIH grant P30 DK036836 (Diabetes Research Center grant, Joslin Diabetes Center), and Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP grant 2018/22111-2.

Authors

Rafael Ferraz-Bannitz, Berkcan Ozturk, Cameron J. Cummings, Vissarion Efthymiou, Pilar Casanova Querol, Lindsay Poulos, Hanna J. Wang, Valerie Navarrete, Hamayle Saeed, Christopher M. Mulla, Hui Pan, Jonathan M. Dreyfuss, Donald C. Simonson, Darleen A. Sandoval, Mary-Elizabeth Patti

Uterine cyclin A2 deficient mice as a model of female early pregnancy loss

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Abstract

Proper action of the female sex steroids, 17β-estradiol (E2) and progesterone (P4) on endometrium is essential for fertility. Beyond its role in regulating the cell cycle, cyclin A2 (CCNA2) also mediates E2 and P4 signaling in vitro, but a potential role in modulating steroid action for proper endometrial tissue development and function is unknown. To fill this gap in our knowledge, we examined human endometrial tissue from fertile and infertile women for CCNA2 expression and correlated this with pregnancy outcome. Functional assessment of CCNA2 was validated in vivo using a conditional Ccna2 uterine deficient mouse model while in vitro function was assessed using human cell culture models. We found that CCNA2 expression was significantly reduced in endometrial tissue, specifically the stromal cells, from women undergoing in vitro fertilization who failed to achieve pregnancy. Conditional deletion of Ccna2 from mouse uterine tissue resulted in an inability to achieve pregnancy which appears to be due to alterations in the process of decidualization, which was confirmed using in vitro models. From these studies, we conclude that CCNA2 expression during the proliferative/regenerative stage of the menstrual cycle acts as a safeguard allowing for proper steroid responsiveness, decidualization and pregnancy. When CCNA2 expression levels are insufficient there is impaired endometrial responsiveness, aberrant decidualization and loss of pregnancy.

Authors

Fatimah Aljubran, Katelyn Schumacher, Amanda Graham, Sumedha Gunewardena, Courtney Marsh, Michael Lydic, Kristin Holoch, Warren B. Nothnick

A six-year study in a real-world population reveals an increased incidence of dyslipidemia during COVID-19

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Abstract

BACKGROUND. Recent studies conducted in COVID-19 survivors suggest that SARS-CoV-2 infection is associated with an increased risk of dyslipidemia. However, it remains unclear whether this augmented risk is confirmed in the general population and how this phenomenon is impacting the overall burden of cardiometabolic diseases. METHODS. To address these aspects, we conducted a 6-year longitudinal study to examine the broader effects of COVID-19 on dyslipidemia incidence within a real-world population (228,266 subjects) residing in Naples, Southern Italy. The pre-COVID-19 and the COVID-19 groups were balanced for demographic and clinical factors using propensity score matching. RESULTS. Our analysis spans over a period of three years during the pandemic (2020–2022), comparing dyslipidemia incidence with pre-pandemic data (2017–2019), with a follow-up time of at least 1,095 days corresponding to 21,349,215 person-years. During the COVID-19 period we detected an increased risk of developing any dyslipidemia when compared with the pre-COVID-19 triennium (OR = 1.29, 95% CI 1.19–1.39). Importantly, these estimates were adjusted for comorbidities by a multivariate analysis. CONCLUSIONS. Taken together, our data reveal a notable rise in dyslipidemia incidence amid the COVID-19 pandemic, suggesting to establish specialized clinical monitoring protocols for COVID-19 survivors to mitigate the risk of dyslipidemia development.

Authors

Valentina Trimarco, Raffaele Izzo, Stanislovas S. Jankauskas, Mario Fordellone, Giuseppe Signoriello, Maria Virginia Manzi, Maria Lembo, Paola Gallo, Giovanni Esposito, Roberto Piccinocchi, Francesco Rozza, Carmine Morisco, Pasquale Mone, Gaetano Piccinocchi, Fahimeh Varzideh, Bruno Trimarco, Gaetano Santulli

Epigenetic regulation of cell state by H2AFY governs immunogenicity in high-risk neuroblastoma

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Abstract

Childhood neuroblastoma with MYCN-amplification is classified as high-risk and often relapses after intensive treatments. Immune checkpoint blockade therapy against the PD-1/L1 axis shows limited efficacy in neuroblastoma patients and the cancer intrinsic immune regulatory network is poorly understood. Here, we leverage genome-wide CRISPR/Cas9 screens and identify H2AFY as a resistance gene to the clinically approved PD-1 blocking antibody, nivolumab. Analysis of single-cell RNA sequencing datasets reveals that H2AFY mRNA is enriched in adrenergic cancer cells and is associated with worse patient survival. Genetic deletion of H2afy in MYCN-driven neuroblastoma cells reverts in vivo resistance to PD-1 blockade by eliciting activation of the adaptive and innate immunity. Mapping of the epigenetic and translational landscape demonstrates that H2afy deletion promotes cell transition to a mesenchymal-like state. With a multi-omics approach, we uncover H2AFY-associated genes that are functionally relevant and prognostic in patients. Altogether, our study elucidates the role of H2AFY as an epigenetic gatekeeper for cell states and immunogenicity in high-risk neuroblastoma.

Authors

Divya Nagarajan, Rebeca T. Parracho, David Corujo, Minglu Xie, Ginte Kutkaite, Thale K. Olsen, Marta Rúbies Bedós, Maede Salehi, Ninib Baryawno, Michael P. Menden, Xingqi Chen, Marcus Buschbeck, Yumeng Mao

Metabolic rewiring during bone development underlies tRNA m⁷G-associated primordial dwarfism

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Abstract

Translation of mRNA to protein is tightly regulated by tRNAs, which are subject to various chemical modifications that maintain the structure, stability and function. Deficiency of tRNA N7-methylguanosine (m7G) modification in patients causes a type of primordial dwarfism, but the underlying mechanism remains unknown. Here we report the loss of m7G rewires cellular metabolism, leading to the pathogenesis of primordial dwarfism. Conditional deletion of the catalytic enzyme Mettl1 or missense mutation of the scaffold protein Wdr4 severely impaired endochondral bone formation and bone mass accrual. Mechanistically, Mettl1 knockout decreased abundance of m7G-modified tRNAs and inhibited translation of mRNAs relating to cytoskeleton and Rho GTPase signaling. Meanwhile, Mettl1 knockout enhanced cellular energy metabolism despite of incompetent proliferation and osteogenic commitment. Further exploration revealed that impaired Rho GTPase signaling upregulated branched-chain amino acid transaminase 1 (BCAT1) level that rewired cell metabolism and restricted intracellular α-ketoglutarate (αKG). Supplementation of αKG ameliorated the skeletal defect of Mettl1-deficient mice. In addition to the selective translation of metabolism-related mRNAs, we further revealed that Mettl1 knockout globally regulated translation via integrated stress response (ISR) and mammalian target of rapamycin complex 1 (mTORC1) signaling. Restoring translation either by targeting ISR or mTORC1 aggravated bone defects of Mettl1-deficient mice. Overall, our study unveils a critical role of m7G tRNA modification in bone development by regulating cellular metabolism, and indicates that suspension of translation initiation as quality control mechanism in response to tRNA dysregulation.

Authors

Qiwen Li, Shuang Jiang, Kexin Lei, Hui Han, Yaqian Chen, Weimin Lin, Qiuchan Xiong, Xingying Qi, Xinyan Gan, Rui Sheng, Yuan Wang, Yarong Zhang, Jieyi Ma, Tao Li, Shuibin Lin, Chenchen Zhou, Demeng Chen, Quan Yuan

Longitudinal analysis of viral dynamics in HIV⁺ to HIV⁺ HOPE Act kidney-transplant recipients

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Abstract

BACKGROUND. The HIV Organ Policy Equity (HOPE) Act allows individuals living with HIV to accept organs from donors with HIV. This practice widens the pool of available organs, but also presents important virological questions, including the potential for HIV superinfection of the recipient, viral persistence in the kidney, and loss of virological control. METHODS. We addressed these questions by performing in-depth longitudinal viral sequence analyses on urine, blood, and urine-derived renal epithelial cells from twelve recipients of HIV+ kidney allografts. RESULTS. We amplified donor-derived HIV-1 env sequences in 5 out of 12 recipients post-transplant. These donor-derived env sequences were amplified from recipient urine, urine-derived renal epithelial cells, and plasma between 12 and 96-hours post-transplant and remained detectable up to 16-days post-transplant. Env sequences were also detected in kidney biopsies taken from the allografts before implantation in 6 out of the 12 transplant cases, indicating the presence of donor virus within the organ. One recipient had a viremic episode 3.5 years after transplantation as a result of ART interruption. Only recipient strain viral sequences were detected in blood, suggesting that the donor virus, if still present, was not reactivated during the temporary ART withdrawal. CONCLUSIONS. This study demonstrates that the HIV env sequences in a donor kidney can be amplified from biopsies taken from the allograft before implantation and can be detected transiently in blood and urine samples collected from the organ recipients post-transplantation.

Authors

Tatianna Travieso, Hannah Stadtler, Naseem Alavian, Feng Gao, Mary Klotman, Cameron R. Wolfe, Maria Blasi

Il-13 induces loss of CFTR in ionocytes and reduces airway epithelial fluid absorption

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Abstract

The airway surface liquid (ASL) plays a crucial role in lung defense mechanisms, and its composition and volume are regulated by the airway epithelium. The cystic fibrosis transmembrane conductance regulator (CFTR) is abundantly expressed in a rare airway epithelial cell type called an ionocyte. Recently, we demonstrated that ionocytes can increase liquid absorption through apical CFTR and basolateral barttin/chloride channels, while airway secretory cells mediate liquid secretion through apical CFTR channels and basolateral NKCC1 transporters. Th2-driven (IL-4/IL-13) airway diseases, such as asthma, cause goblet cell metaplasia, accompanied by increased mucus production and airway secretions. In this study, we investigate the effect of IL-13 on chloride and liquid transport performed by ionocytes. IL-13 treatment of human airway epithelia was associated with reduced epithelial liquid absorption rates and increased ASL volume. Additionally, IL-13 treatment reduced the abundance of CFTR-positive ionocytes and increased the abundance of CFTR-positive secretory cells. Increasing ionocyte abundance attenuated liquid secretion caused by IL-13. Finally, CFTR-positive ionocytes were less common in asthma and COPD and associated with airflow obstruction. Our findings suggest that loss of CFTR in ionocytes contributes to the liquid secretion observed in IL-13-mediated airway diseases.

Authors

Guillermo S. Romano Ibarra, Lei Lei, Wenjie Yu, Andrew L. Thurman, Nicholas D. Gansemer, David K. Meyerholz, Alejandro A. Pezzulo, Paul B. McCray, Ian M. Thornell, David A. Stoltz