BACKGROUND. Although recent epidemiological data suggest that pneumococci may contribute to the risk of SARS-CoV-2 disease, cases of co-infection with Streptococcus pneumoniae in COVID-19 patients during hospitalisation have been reported infrequently. This apparent contradiction may be explained by interactions of SARS-CoV-2 and pneumococcus in the upper airway, resulting in the escape of SARS-CoV-2 from protective host immune responses. METHODS. Here, we investigated the relationship of these two respiratory pathogens in two distinct cohorts of a) healthcare workers with asymptomatic or mildly symptomatic SARS-CoV-2 infection identified by systematic screening and b) patients with moderate to severe disease who presented to hospital. We assessed the effect of co-infection on host antibody, cellular and inflammatory responses to the virus. RESULTS. In both cohorts, pneumococcal colonisation was associated with diminished anti-viral immune responses, which affected primarily mucosal IgA levels among individuals with mild or asymptomatic infection and cellular memory responses in infected patients. CONCLUSION. Our findings suggest that S. pneumoniae impairs host immunity to SARS-CoV-2 and raises the question if pneumococcal carriage also enables immune escape of other respiratory viruses and facilitates reinfection occurrence. TRIALS REGISTRATION. ISRCTN89159899 for FASTER study and Clinicaltrials.gov identifier: NCT03502291 for LAIV study
Elena Mitsi, Jesús Reiné, Britta C. Urban, Carla Solorzano, Elissavet Nikolaou, Angela D. Hyder-Wright, Sherin Pojar, Ashleigh Howard, Lisa Hitchins, Sharon Glynn, Madlen C Farrar, Konstantinos Liatsikos, Andrea M. Collins, Naomi F. Walker, Helen C. Hill, Esther L. German, Katerina S. Cheliotis, Rachel L. Byrne, Christopher T Williams, Ana I. Cubas-Atienzar, Tom E. Fletcher, Emily R. Adams, Simon J. Draper, David Pulido, Rohini Beavon, Christian Theilacker, Elizabeth Begier, Luis Jodar, Bradford D. Gessner, Daniela M. Ferreira
BACKGROUND. Immunization against SARS-CoV-2, the causative agent of coronavirus disease-19 (COVID-19) occurs via natural infection or vaccination. However, it is currently unknown how long infection- or vaccination-induced immunological memory will last. METHODS. We performed a longitudinal evaluation of immunological memory to SARS-CoV-2 up to one year post infection and following mRNA vaccination in naïve and COVID-19 recovered individuals. RESULTS. We found that memory cells are still detectable 8 months after vaccination, while antibody levels decline significantly especially in naïve subjects. We also found that a booster injection is efficacious in reactivating immunological memory to spike protein in naïve subjects, while it results ineffective in previously SARS-CoV-2 infected individuals. Finally, we observed a similar kinetics of decay of humoral and cellular immunity to SARS-CoV-2 up to one year following natural infection in a cohort of unvaccinated individuals. CONCLUSION. Short-term persistence of humoral immunity, together with the reduced neutralization capacity versus the currently prevailing SARS-CoV-2 variants, may account for reinfections and breakthrough infections. Long-lived memory B and CD4+ T cells may protect from severe disease development. A booster dose restores optimal anti-spike immunity in naïve subjects, while the need for vaccinated COVID-19 recovered subjects has yet to be defined. TRIAL REGISTRATION. na FUNDING. This study was supported by funds to the Department of Experimental and Clinical Medicine, University of Florence (Project Excellence Departments 2018-2022), by the University of Florence, project RICTD2122, by the Italian Ministry of Health (COVID-2020-12371849) and by Tuscany Region (TagSARS CoV 2).
Alessio Mazzoni, Anna Vanni, Michele Spinicci, Giulia Lamacchia, Seble Tekle Kiros, Arianna Rocca, Manuela Capone, Nicoletta Lauria, Lorenzo Salvati, Alberto Carnasciali, Elisabetta Mantengoli, Parham Farahvachi, Lorenzo Zammarchi, Filippo Lagi, Maria Grazia Colao, Francesco Liotta, Lorenzo Cosmi, Laura Maggi, Alessandro Bartoloni, Gian Maria Rossolini, Francesco Annunziato
The causative role of inflammation in hypertension-related cardiovascular diseases is evident and calls for development of specific immunomodulatory therapies. We tested the therapeutic efficacy and mechanisms of action of developmental endothelial locus-1 (DEL-1), an endogenous anti-inflammatory factor, in angiotensin-II (ANGII)- and DOCA (deoxycorticosterone acetate)-salt-induced cardiovascular organ damage and hypertension. By using mice with endothelial overexpression of DEL-1 (EC-Del1) and performing preventive and interventional studies by injecting recombinant DEL-1 in mice, we showed that DEL-1 improved endothelial function and abrogated aortic adventitial fibrosis, medial thickening and loss of elastin. DEL-1 also protected the mice from cardiac concentric hypertrophy, interstitial and perivascular coronary fibrosis and improved left-ventricular function and myocardial coronary perfusion. DEL-1 prevented aortic stiffness and abolished the progression of hypertension. Mechanistically, DEL-1 acted by inhibiting αvβ3-integrin dependent activation of pro-MMP2 in mice and in human isolated aorta. Moreover, DEL-1 stabilized αvβ3-integrin dependent CD25+FoxP3+ Treg numbers and IL-10 levels, which were associated with decreased pro-inflammatory cell recruitment of inflammatory cells and reduced production of pro-inflammatory cytokines in cardiovascular organs. The demonstrated effects and immune-modulating mechanisms of DEL-1 in abrogation of cardiovascular remodeling and progression of hypertension identify DEL-1 as a potential therapeutic factor.
Theresa Failer, Michael Amponsah-Offeh, Aleš Neuwirth, Ioannis Kourtzelis, Pallavi Subramanian, Peter Mirtschink, Mirko Peitzsch, Klaus Matschke, Sems M. Tugtekin, Tetsuhiro Kajikawa, Xiaofei Li, Anne Steglich, Florian Gembardt, Annika C. Wegner, Christian Hugo, George Hajishengallis, Triantafyllos Chavakis, Andreas Deussen, Vladimir Todorov, Irakli Kopaliani
The heart utilizes multiple adaptive mechanisms to maintain pump function. Compensatory cardiac hypertrophy reduces wall stress and oxygen consumption, thereby protecting the heart against acute blood pressure elevation. The nuclear effector of the Hippo pathway, Yes-associated protein 1 (YAP), is activated and mediates compensatory cardiac hypertrophy in response to acute pressure overload (PO). In this study, YAP promoted glycolysis by upregulating glucose transporter 1 (GLUT1), which in turn caused accumulation of intermediates and metabolites of the glycolytic, auxiliary, and anaplerotic pathways during acute PO. Cardiac hypertrophy was inhibited and heart failure was exacerbated in mice with YAP haploinsufficiency in the presence of acute PO. However, normalization of GLUT1 rescued the detrimental phenotype. PO induced accumulation of glycolytic metabolites, including L-serine, L-aspartate, and malate, in a YAP-dependent manner, thereby promoting cardiac hypertrophy. YAP upregulated the GLUT1 gene through interaction with TEAD1 and HIF-1α in cardiomyocytes. Thus, YAP induces compensatory cardiac hypertrophy through activation of the Warburg effect.
Toshihide Kashihara, Risa Mukai, Shin-ichi Oka, Peiyong Zhai, Yasuki Nakada, Zhi Yang, Wataru Mizushima, Tsutomu Nakahara, Junco S. Warren, Maha Abdellatif, Junichi Sadoshima
Trained immunity refers to the long-lasting memory traits of innate immunity. Recent studies have shown that trained immunity is orchestrated by sustained changes in epigenetic marks and metabolic pathways, leading to an altered transcriptional response towards a second challenge. However, the potential heterogeneity of trained immunity induction in innate immune cells has not been explored. In this study, we demonstrate cellular transcriptional programs to four different inducers of trained immunity in monocyte populations at single-cell resolution. Specifically, we identified three monocyte subpopulations upon the induction of trained immunity, and replicated these findings in an in vivo study. In addition, we found gene signatures consistent with these functional programs in ulcerative colitis, sepsis and COVID-19 patients, suggesting the impact of trained immunity programs in immune-mediated diseases.
Bowen Zhang, Simone J.C.F.M. Moorlag, Jorge Domínguez-Andrés, Özlem Bulut, Gizem Kilic, Zhaoli Liu, Reinout van Crevel, Cheng-Jian Xu, Leo A.B. Joosten, Mihai G. Netea, Yang Li
Despite long-term antiretroviral therapy (ART), HIV-1 persists within a reservoir of CD4+ T-cells that contribute to viral rebound if treatment is interrupted. Identifying the cellular populations that contribute to the HIV-1 reservoir and understanding the mechanisms of viral persistence are necessary to achieve an effective cure. In this regard, through Full-Length Individual Proviral Sequencing, we observed that the HIV-1 proviral landscape was different and changed with time on ART across naïve and memory CD4+ T-cell subsets isolated from 24 participants. We found that the proportion of genetically-intact HIV-1 proviruses was higher and persisted over time in effector memory CD4+ T-cells when compared with naïve, central, and transitional memory CD4+ T-cells. Interestingly, we found that escape mutations remained stable over time within effector memory T-cells during therapy. Finally, we provided evidence that Nef plays a role in the persistence of genetically-intact HIV-1. These findings posit effector memory T-cells as a key component of the HIV-1 reservoir and suggest Nef as an attractive therapeutic target.
Gabriel Duette, Bonnie Hiener, Hannah Morgan, Fernando G. Mazur, Vennila Mathivanan, Bethany A. Horsburgh, Katie Fisher, Orion Tong, Eunok Lee, Haelee Ahn, Ansari Shaik, Rémi Fromentin, Rebecca Hoh, Charline Bacchus-Souffan, Najla Nasr, Anthony Cunningham, Peter W. Hunt, Nicolas Chomont, Stuart G. Turville, Steven G. Deeks, Anthony D. Kelleher, Timothy E. Schlub, Sarah Palmer
Emerging studies have focused on ways to treat cancers by modulating T cell activation. However, whether B cell receptor signaling in the tumor microenvironment (TME) can be harnessed for immunotherapy is unclear. Here we reported that an Asian-specific variant of human IgG1 containing a Gly396 to Arg396 substitution (hIgG1-G396R) conferred improved survival of colorectal cancer (CRC) patients. Murine functional homolog mIgG2c-G400R knock-in mice recapitulated the alleviated tumorigenesis and progression in murine colon carcinoma models. Immune profiling of the TME revealed broad mobilizations of IgG1+ plasma cells, CD8+ T cells, CD103+ DCs and active tertiary lymphoid structure formation, suggesting effective anti-tumor microenvironment in hIgG1-G396R CRC patients. Mechanistically, this variant potentiated tumor-associated antigen (TAA)-specific plasma cell differentiation and thus antibody production. These elevated TAA-specific IgG2c antibodies in turn efficiently boosted the antibody-dependent tumor cell phagocytosis and TAA presentation to effector CD8+ T cells. Notably, adoptive transfer of TAA-specific class-switched memory B cells harboring this variant exhibited therapeutic efficacy in murine tumor models, indicating the clinical potential. All these results prompted a prospective investigation of hIgG1-G396R in CRC patients as a biomarker for clinical prognosis and demonstrated that manipulating the functionality of IgG1+ memory B cells in tumors could improve immunotherapy outcomes.
Bing Yang, Zhen Zhang, Xiangjun Chen, Xu-Yan Wang, Shishang Qin, Liaoqi Du, Changjiang Yang, Liyu Zhu, Wenbo Sun, Yongjie Zhu, Qinwen Zheng, Shidong Zhao, Quan Wang, Long Zhao, Yilin Lin, Jinghe Huang, Fan Wu, Lu Lu, Fei Wang, Wenjie Zheng, Xiao-Hua Zhou, Xiaozhen Zhao, Ziye Wang, Xiaolin Sun, Yingjiang Ye, Shan Wang, Zhanguo Li, Hai Qi, Zemin Zhang, Dong-Ming Kuang, Lei Zhang, Zhanlong Shen, Wanli Liu
Glioblastoma (GBM) is the most common and lethal primary malignant brain tumor, containing GBM stem cells (GSCs) that contribute to therapeutic resistance and relapse. Exposing potential GSC vulnerabilities may provide therapeutic strategies against GBM. Here, we interrogated the role of Adenosine-to-Inosine (A-to-I) RNA editing mediated by ADAR1 (adenosine deaminase acting on RNA 1) in GSCs and found that both ADAR1 and global RNA editomes were elevated in GSCs compared to normal neural stem cells (NSCs). ADAR1 inactivation or blocking the upstream JAK/STAT pathway through TYK2 inhibition impaired GSC self-renewal and stemness. Downstream of ADAR1, RNA editing of the 3’UTR of GM2A, a key ganglioside catabolism activator, proved to be critical, as interfering with ganglioside catabolism showed similar functional impact on GSCs as ADAR1 disruption. These findings reveal RNA editing links ganglioside catabolism to GSC self-renewal and stemness, exposing a potential vulnerability of GBM for therapeutic intervention.
Li Jiang, Yajing Hao, Changwei Shao, Qiulian Wu, Briana C. Prager, Ryan C. Gimple, Gabriele Sulli, Leo J.K. Kim, Guoxin Zhang, Zhixin Qiu, Zhe Zhu, Xiang-Dong Fu, Jeremy N. Rich
BACKGROUND. Currently, there is no disease-specific therapy for osteogenesis imperfecta (OI). Preclinical studies have shown that excessive TGF-β signaling is a driver of pathogenesis in OI. Here, we evaluated TGF-β signaling in children with OI and translated this discovery by conducting a phase 1 clinical trial of TGF-β inhibition in adults with OI. METHODS. Histology and RNASeq were performed on bones obtained from children affected (n=10) and unaffected (n=4) by OI. Gene Ontology (GO) enrichment assay, gene set enrichment analysis (GSEA), and Ingenuity Pathway Analysis (IPA) were used to identify key dysregulated pathways. Reverse-phase protein array (RPPA), Western blot (WB), and Immunohistochemistry (IHC) were performed to evaluate changes at the protein level. A phase 1 study with a single administration of fresolimumab, a pan-anti-TGF-β neutralizing antibody, was conducted in 8 adults with OI. Safety and effects of fresolimumab on bone remodeling markers and lumbar spine areal bone mineral density (LS aBMD) were assessed. RESULTS. OI bone demonstrated woven structure, increased osteocyte density, high turnover, and reduced bone maturation. SMAD phosphorylation was the most significantly up-regulated GO molecular event. GSEA identified TGF-β pathway as top activated signaling pathway in OI. IPA showed that TGF-β was the most significant activated upstream regulator mediating the global changes identified in OI bone. Treatment with fresolimumab was well-tolerated and associated with increase in LS aBMD in participants with OI type IV, while those with more severe OI type III and VIII had unchanged or decreased LS aBMD. CONCLUSIONS. Our data confirm that TGF-β signaling is a driver pathogenic mechanism in OI bone and that anti-TGF-β therapy could be a potential disease-specific therapy with dose-dependent effects on bone mass and turnover. TRIAL REGISTRATION. NCT03064074 FUNDING. This work was supported by the Brittle Bone Disorders Consortium (BBDC) (U54AR068069). The BBDC is a part of the National Center for Advancing Translational Science’s (NCATS’) RDCRN. The BBDC is funded through a collaboration between the Office of Rare Disease Research (ORDR) of NCATS, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institute of Dental and Craniofacial Research (NIDCR), National Institute of Mental Health (NIMH) and National Institute of Child Health and Human Development (NICHD). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The BBDC was also supported by the OI Foundation. The work was supported by The Clinical Translational Core of BCM IDDRC (P50HD103555) from the Eunice Kennedy Shriver NICHD. Funding from the USDA/ARS under Cooperative Agreement No. 58-6250-6-001 also facilitated analysis for the study procedures. The contents of this publication do not necessarily reflect the views or policies of the USDA, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government. The study was supported by a research agreement with Sanofi Genzyme.
I-Wen Song, Sandesh C.S. Nagamani, Dianne Nguyen, Ingo Grafe, Vernon Reid Sutton, Francis H. Gannon, Elda Munivez, Ming-Ming Jiang, Alyssa Tran, Maegen Wallace, Paul Esposito, Salma Musaad, Elizabeth Strudthoff, Sharon McGuire, Michele Thornton, Vinitha Shenava, Scott Rosenfeld, Roman Shypailo, Eric Orwoll, Brendan Lee
BMP6 is a central cytokine in the induction of Sjögren's syndrome (SS)-associated secretory hypofunction. However, the upstream initiation leading to the production of this cytokine in SS is unknown. In this study, RNA in situ hybridization on salivary gland sections taken from SS patients indicated monocytic lineage cells as a cellular source of BMP6. RNA sequencing data from human salivary glands suggested TLR4 signaling was an upstream regulator of BMP6, which was confirmed by in vitro cell assays and single-cell transcriptomics of human PBMCs. Further investigation showed HSP70 was an endogenous natural TLR4 ligand that stimulated BMP6 expression in SS. Release of HSP70 from epithelial cells could be triggered by overexpression of lysosome-associated membrane protein 3 (LAMP3), a protein also associated with SS in several transcriptome studies. In vitro studies supported HSP70 was released as a result of lysosomal exocytosis initiated by LAMP3 expression, and reverse transcription PCR on RNA from minor salivary glands of SS patients confirmed a positive correlation between BMP6 and LAMP3 expression. BMP6 expression could be experimentally induced in mice by overexpression of LAMP3, which developed an SS-like phenotype. The newly identified LAMP3/HSP70/BMP6 axis provided an etiological model for SS gland dysfunction and autoimmunity.
Ying-Qian Mo, Hiroyuki Nakamura, Tsutomu Tanaka, Toshio Odani, Paola Perez, Youngmi Ji, Benjamin N. French, Thomas J.F. Pranzatelli, Drew G. Michael, Hongen Yin, Susan S. Chow, Maryam Khalaj, Sandra A. Afione, Changyu Zheng, Fabiola Reis Oliveira, Ana Carolina F. Motta, Alfredo Ribeiro-Silva, Eduardo M. Rocha, Cuong Q. Nguyen, Masayuki Noguchi, Tatsuya Atsumi, Blake M. Warner, John A. Chiorini
New approaches for the management of glioblastoma (GBM) are an urgent and unmet clinical need. Here, we illustrate that the efficacy of radiotherapy for GBM is strikingly potentiated by concomitant therapy with the arginine depleting agent ADI-PEG20 in a non-arginine auxotrophic cellular background (Arginine Succinate Synthetase 1 positive). Moreover, this combination led to durable and complete radiological and pathological response with extended disease-free survival in an orthotopic immune competent model of GBM with no significant toxicity. ADI-PEG20 not only enhances the cellular sensitivity of Arginine succinate synthetase 1 positive GBM to ionising radiation by elevated production of nitric oxide (NO) and hence generation of cytotoxic peroxynitrites, but also promotes glioma-associated macrophages/microglia infiltration into tumors and turns their classical anti-inflammatory (pro-tumor) phenotype into a pro-inflammatory (anti-tumor) phenotype. Our results provide an effective, well-tolerated and simple strategy to improve GBM treatment which merits consideration for early evaluation in clinical trials.
Nabil Hajji, Juan Garcia-Revilla, Manuel Sarmiento Soto, Richard Perryman, Jake J. Symington, Chad C. Quarles, Deborah R. Healey, Yijie Guo, Manuel Luis Orta-Vázquez, Santiago Mateos-Cordero, Khalid Shah, John Bomalaski, Giulio Anichini, Andreas G. Tzakos, Timothy Crook, Kevin O'Neill, Adrienne C. Scheck, Jose Luis Venero, Nelofer Syed
Genetic variants at the SORT1 locus in humans causing increased SORT1 expression in liver are significantly associated with reduced plasma levels of LDL cholesterol and apolipoprotein B (apoB). However, the role of hepatic sortilin remains controversial, as genetic deletion of sortilin in mice has yielded variable and conflicting effects on apoB secretion. Sort1 knockout mice on a chow diet and several Sort1-deficient hepatocyte lines displayed no difference in apoB secretion. When these models were challenged with high fat or ER stress, the loss of Sort1 expression resulted in a significant increase in apoB-100 secretion. Sort1 overexpression studies yielded reciprocal results. Importantly, diabetic carriers of SORT1 variant have larger decreases in plasma apoB, TG, and VLDL and LDL particle number as compared to non-diabetics with the same variants. We conclude that under basal non-stressed conditions, loss of sortilin has little effect on hepatocyte apoB secretion, but that in the setting of lipid-loading or ER stress, sortilin deficiency leads to increased apoB secretion. These results are consistent with the directionality of effect in human genetics studies and suggest that under stress conditions, hepatic sortilin directs apoB toward lysosomal degradation rather than secretion, potentially serving as a quality control step in the apoB secretion pathway in hepatocytes.
Donna M. Conlon, Carolin V. Schneider, Yi-An Ko, Amrith Rodrigues, Kathy Guo, Nicholas J. Hand, Daniel J. Rader
BACKGROUND. Bacterial vaginosis (BV) causes genital inflammation and increases HIV risk, while a vaginal microbiota dominated by Lactobacillus species is associated with immune quiescence and relative HIV protection. BV treatment reduces genital inflammation, but it is unclear whether this is driven by a decrease in BV-associated bacteria or an increase in Lactobacillus. METHODS. To evaluate the short-term impact of standard BV treatment on genital immunology and the vaginal microbiota, vaginal swabs were collected immediately before and after metronidazole treatment for BV and analyzed with multiplex ELISA, metagenomic sequencing, and quantitative polymerase chain reaction. RESULTS. Topical metronidazole treatment rapidly reduced vaginal levels of proinflammatory cytokines, chemokines, and soluble immune markers of epithelial barrier disruption. Although the vaginal microbiota shifted to dominance by L. iners or L. jensenii, this proportional shift was primarily driven by a 2-4 log10 fold reduction in BV-associated bacteria absolute abundance; BV treatment induced no change in the absolute abundance of L. crispatus or L. iners, and only minor (<1 log10 fold) increases in L. gasseri and L. jensenii that were not independently associated with reduced inflammation in multivariable models. CONCLUSION. The genital immune benefits that are associated with Lactobacillus dominance following BV treatment were not directly attributable to an absolute increase in lactobacilli, but rather to the loss of BV-associated bacteria. TRAIL REGISTRATION. Participants were recruited as part of a randomized controlled trial (NCT02766023) from 2016 to 2020. FUNDING. Canadian Institutes of Health Research (PJT-156123) and the National Institute of Allergy and Infectious Diseases (HHSN2722013000141 and HHSN27200007).
Eric Armstrong, Anke Hemmerling, Steve Miller, Kerianne E. Burke, Sara J. Newmann, Sheldon R. Morris, Hilary Reno, Sanja Huibner, Maria Kulikova, Rachel Liu, Emily D. Crawford, Gloria R. Castañeda, Nico Nagelkerke, Bryan Coburn, Craig R. Cohen, Rupert Kaul
Immune checkpoint blockade (ICB) therapy has shifted the paradigm for cancer treatment. However, the majority of patients lack effective responses due to the emergence of immune-refractory tumors that disrupt the amplification of anti-tumor immunity. Therefore, identifying clinically available targets that restrict anti-tumor immunity is required to develop potential combination strategies. Here, using the transcriptome data of cancer patients treated with programmed cell death protein-1 (PD-1) therapy, and newly-established mouse preclinical anti-PD-1 therapy-refractory models, we identified NANOG as a novel factor restricting the amplification of anti-tumor immunity cycle, thereby contributing to the immune-refractory feature of the tumor microenvironment (TME). Mechanistically, NANOG induced insufficient T cell infiltration and resistance to CTL-mediated killing via the HDAC1-dependent regulation of CXCL10 and MCL1, respectively. Importantly, HDAC1 inhibition using an actionable agent sensitized NANOGhigh immune-refractory tumors to PD-1 blockade by reinvigorating the anti-tumor immunity cycle. Thus, our findings implicate the NANOG/HDAC1 axis as a central molecular target for controlling immune-refractory tumors and provide a rationale for combining HDAC inhibitors to reverse the refractoriness of tumors to ICB therapy.
Se Jin Oh, Hyo-Jung Lee, Kwon-Ho Song, Suyeon Kim, Eunho Cho, Jaeyoon Lee, Marcus W. Bosenberg, Tae Woo Kim
Multiple beneficial cardiovascular effects of HDL are dependent on sphingosine-1-phosphate (S1P). S1P associates with HDL by binding to apolipoprotein M (ApoM). Insulin resistance is a major driver of dyslipidemia and cardiovascular risk. However, the mechanisms linking alterations in insulin signaling with plasma lipoprotein metabolism are incompletely understood. The insulin-repressible FoxO transcription factors play a key role in mediating the effects of hepatic insulin action on glucose and lipoprotein metabolism. This work aims to determine whether hepatic insulin signaling regulates HDL-S1P, and the underlying molecular mechanisms.We report that insulin resistant, nondiabetic human subjects in two independent cohorts have decreased HDL-S1P levels, but no change in total plasma S1P. This also occurs in the mouse model of insulin resistance, db/db mice, which have low ApoM and a specific reduction of S1P in the HDL fraction, with no change in total plasma S1P. Using mice with hepatocyte deletion of the three insulin-repressible FoxO transcription factors (L-FoxO1,3,4), we found that hepatic FoxOs are required for ApoM expression and S1P association with HDL, without affecting total plasma S1P. In L-FoxO1,3,4 mice, total plasma S1P levels are similar to controls, but S1P is nearly absent from HDL, and is instead increased in the lipoprotein depleted plasma fraction. This phenotype is restored to normal by rescuing ApoM in L-FoxO1,3,4 mice. Our findings show that insulin resistance in humans and mice is associated with decreased HDL-associated S1P. Hepatic FoxO transcription factors are novel regulators of the ApoM-S1P pathway.
María Concepción Izquierdo, Niroshan Shanmugarajah, Samuel X. Lee, Michael J. Kraakman, Marit Westerterp, Takumi Kitamoto, Michael Harris, Joshua R. Cook, Galina A. Gusarova, Kendra Zhong, Elijah Marbuary, InSug O-Sullivan, Nikolaus F. Rasmus, Stefania Camastra, Terry G. Unterman, Ele Ferrannini, Barry E. Hurwitz, Rebecca A. Haeusler
Blood vessel abnormalization alters cancer cell metabolism and promotes cancer dissemination and metastasis. However, the biological features of the abnormalized blood vessels that facilitate cancer progression and whether they can be targeted therapeutically have not been fully investigated. Here, we found that an axon guidance molecule, fibronectin leucine-rich transmembrane protein 2 (FLRT2), is expressed preferentially in abnormalized vessels of advanced colorectal cancers in humans, and that its expression correlates negatively with long-term survival. Endothelial-specific deletion of Flrt2 in mice selectively pruned abnormalized vessels, resulting in a unique metabolic state termed “oxygen-glucose uncoupling”, which suppresses tumor metastasis. Moreover, Flrt2 deletion caused an increase in the number of mature vessels, resulting in a significant increase in the anti-tumor effects of immune checkpoint blockers. Mechanistically, we found that FLRT2 forms non-canonical inter-endothelial adhesions that safeguard against oxidative stress through homophilic binding. Together, our results demonstrate the existence of tumor-specific inter-endothelial adhesions that enable abnormalized vessels to facilitate cancer aggressiveness. Targeting this type of adhesion complex could be a safe and effective therapeutic option to suppress cancer progression.
Tomofumi Ando, Ikue Tai-Nagara, Yuki Sugiura, Dai Kusumoto, Koji Okabayashi, Yasuaki Kido, Kohji Sato, Hideyuki Saya, Sutip Navankasattusas, Dean Y. Li, Makoto Suematsu, Yuko Kitagawa, Elena Seiradake, Satoru Yamagishi, Yoshiaki Kubota
SMAD3 plays a central role in cancer metastasis, and its hyperactivation is linked to poor cancer outcomes. Thus, it is critical to understand the upstream signaling pathways that govern SMAD3 activation. Here, we report that SMAD3 undergoes methylation at K53 and K333 by EZH2, a process crucial for cell membrane recruitment, phosphorylation, and activation of SMAD3 upon TGFB1 stimulation. Mechanistically, EZH2-triggered SMAD3 methylation facilitates SMAD3 interaction with its cellular membrane localization molecule (SARA), which in turn sustains SMAD3 phosphorylation by the TGFB receptor. Pathologically, EZH2 expression increasing results in the accumulation of SMAD3 methylation to facilitate SMAD3 activation. EZH2-mediated SMAD3 K53/K333 methylation is upregulated and correlated with SMAD3 hyperactivation in breast cancer, promotes tumor metastasis, and is predictive of poor survival outcome. We used two TAT-peptides to abrogate SMAD3 methylation and therapeutically inhibit cancer metastasis. Collectively, these findings reveal the complicated layers in regulation of SMAD3 activation coordinated by EZH2-mediated SMAD3 K53/K333 methylation to drive cancer metastasis.
Changsheng Huang, Fuqing Hu, Da Song, Xuling Sun, Anyi Liu, Qi Wu, Xiaowei She, Yaqi Chen, Lisheng Chen, Fayong Hu, Feng Xu, Xuelai Luo, Yongdong Feng, Xiangping Yang, Junbo Hu, Guihua Wang
Tuberculous (TB) meningitis is the most severe form of TB, requiring 12 months of multidrug treatment for cure, and is associated with high morbidity and mortality. High-dose rifampin (35 mg/kg/day) is safe and improves the bactericidal activity of the standard-dose (10 mg/kg/day) rifampin-containing TB regimen in pulmonary TB. However, there are conflicting clinical data regarding its benefit for TB meningitis, where outcomes may also be associated with intracerebral inflammation. In this study, we conducted cross-species studies in mice and rabbits, demonstrating that an intensified high-dose rifampin-containing regimen has significantly improved bactericidal activity for TB meningitis over the first-line, standard-dose rifampin regimen, without an increase in intracerebral inflammation. Positron emission tomography in live animals demonstrated spatially compartmentalized, lesion-specific pathology, with post-mortem analyses showing discordant brain tissue and cerebrospinal fluid rifampin levels and inflammatory markers. Longitudinal multimodal imaging in the same cohort of animals during TB treatment as well as imaging studies in two cohorts of TB patients demonstrated that spatiotemporal changes in localized blood-brain barrier disruption in TB meningitis are an important driver of rifampin brain exposure. These data provide unique insights into the mechanisms underlying high-dose rifampin in TB meningitis with important implications for developing new antibiotic treatments for infections.
Camilo A. Ruiz-Bedoya, Filipa Mota, Elizabeth W. Tucker, Farina J. Mahmud, Maria I. Reyes-Mantilla, Clara Erice, Melissa Bahr, Kelly Flavahan, Patricia De Jesus, John Kim, Catherine A. Foss, Charles A. Peloquin, Dima A. Hammoud, Alvaro A. Ordonez, Carlos A. Pardo, Sanjay K. Jain
Eltrombopag, an FDA-approved non-peptidyl thrombopoietin receptor agonist is clinically used for the treatment of aplastic anemia, a disease characterized by hematopoietic stem cell failure and pancytopenia, to improve platelet counts and stem cell function. Eltrombopag treatment results in durable tri-lineage hematopoietic expansion in patients. Some of the eltrombopag hematopoietic activity has been attributed to its off-target effects including its iron chelation properties. However, eltrombopag mechanism of action is still poorly understood with respect to its full spectrum of clinical effects. Here, we report that eltrombopag bound to the TET2 catalytic domain and inhibited its dioxygenase activity, which was independent of its iron chelating activity. The DNA demethylating enzyme TET2, essential for hematopoietic stem cell differentiation and lineage commitment, is frequently mutated in myeloid malignancies. Eltrombopag treatment expanded TET proficient normal hematopoietic stem and progenitor cells, in part, due to its ability to mimic loss of TET2 with simultaneous thrombopoietin receptor activation. On the contrary, TET inhibition in TET2 mutant malignant myeloid cells prevented neoplastic clonal evolution, in vitro and in vivo. This new mechanism of action may offer a restorative therapeutic index and provide a scientific rationale to treat selected patients with TET2-mutant or TET deficiency associated myeloid malignancies.
Yihong Guan, Metis Hasipek, Dongxu Jiang, Anand D. Tiwari, Dale R. Grabowski, Simona Pagliuca, Sunisa Kongkiatkamon, Bhumika Patel, Salendra Singh, Yvonne Parker, Thomas LaFramboise, Daniel Lindner, Mikkael A. Sekeres, Omar Y. Mian, Yogen Saunthararajah, Jaroslaw P. Maciejewski, Babal K. Jha
BACKGROUND. The heterogeneity of tinnitus is thought to underlie the lack of objective diagnostic measures. METHODS. Longitudinal data from 20,349 participants of the Swedish Longitudinal Occupational Survey of Health (SLOSH) cohort from 2008 to 2018 was used to understand the dynamics of transition between occasional and constant tinnitus. The second part of the study included electrophysiological data from 405 participants of the Swedish Tinnitus Outreach Project (STOP) cohort. RESULTS. We determined that with increasing frequency of the occasional perception of self-reported tinnitus, the odds of reporting constant tinnitus after 2 years increases from 5 for previous tinnitus (sometimes) to 30 for previous tinnitus (often). When previous tinnitus was reported to be constant, the odds of reporting it as constant after 2 years rose to 603, suggesting that once transitioned to constant tinnitus, the likelihood of tinnitus to persist was much greater. Auditory brainstem responses (ABRs) from subjects reporting non-tinnitus (controls), occasional tinnitus, and constant tinnitus show that wave V latency increased in constant tinnitus when compared to occasional tinnitus or non-tinnitus. The ABR from occasional tinnitus was indistinguishable from that of the non-tinnitus controls. CONCLUSIONS. Our results support the hypothesis that the transition from occasional to constant tinnitus is accompanied by neuronal changes in the midbrain leading to a persisting tinnitus, which is then less likely to remit. TRIAL REGISTRATION. Not applicable FUNDING. This study was supported by the GENDER-Net Co-Plus Fund (GNP-182), the European Union’s Horizon 2020 Grant No. 848261 (UNITI) and No. 722046 (ESIT).
Niklas K. Edvall, Golbarg Mehraei, Martin Claeson, Andra Lazar, Jan Bulla, Constanze Leineweber, Inger Uhlén, Barbara Canlon, Christopher R. Cederroth