In-Press Preview
Abstract
Tissue regeneration capacity declines with aging in association with heightened oxidative stress. Expression of the oxidant-generating enzyme, NADPH oxidase 4 (Nox4) is elevated in aged mice with diminished capacity for fibrosis resolution. Bromodomain-containing protein 4 (Brd4) is a member of the bromodomain and extraterminal (BET) family of proteins that function as epigenetic “readers” of acetylated lysine groups on histones. In this study, we explored the role of Brd4 and its interaction with the p300 acetyltransferase in the regulation of Nox4, and the in-vivo efficacy of a BET inhibitor to reverse established age-associated lung fibrosis. BET inhibition interferes with the association of Brd4, p300, and acetylated histone H4K16 with the Nox4 promoter in lung fibroblasts stimulated with the pro-fibrotic cytokine, transforming growth factor-β1 (TGF-β1). This Brd4-Nox4 epigenetic axis is constitutively upregulated in fibroblasts from human subjects with idiopathic pulmonary fibrosis. A number of BET inhibitors, including I-BET-762, JQ1, and OTX015, downregulate Nox4 gene expression and activity. Aged mice with established and persistent lung fibrosis recovered capacity for fibrosis resolution with OTX015 treatment. This study implicates epigenetic regulation of Nox4 by Brd4 and p300, and supports BET/Brd4 inhibition as an effective strategy for the treatment of age-related fibrotic lung disease.
Authors
Yan Y. Sanders, Xing Lyu, Q. Jennifer Zhou, Zheyi Xiang, Denise Stanford, Sandeep Bodduluri, Steven M. Rowe, Victor J. Thannickal
Abstract
Purinergic modulators, such as dipyridamole, target multiple pathways that have been implicated in COVID-19 pathogenesis, and thus the therapeutic benefit of these should be explored.
Authors
Yogendra Kanthi, Jason S. Knight, Yu Zuo, David J. Pinsky
Abstract
Regulatory T cells (Tregs) play essential roles in maintaining immunological self-tolerance and preventing autoimmunity. The adoptive transfer of antigen-specific Tregs has been expected to be a potent therapeutic method for autoimmune diseases, severe allergy, and rejection in organ transplantation. However, effective Treg therapy has not yet been established because of the difficulty in preparing a limited number of antigen-specific Tregs. Chimeric antigen receptor (CAR) T cells have been shown to be a powerful therapeutic method for treating B cell lymphomas, but application of CAR to Treg-mediated therapy has not yet been established. Here, we generated CD19-targeted CAR (CD19-CAR) Tregs from human peripheral blood mononuclear cells (hPBMCs) and optimized the fraction of the Treg source as CD4+CD25+CD127lowCD45RA+CD45RO–. CD19-CAR Tregs could be expanded in vitro while maintaining Treg properties, including a high expression of the latent form of TGF-β. CD19-CAR Tregs suppressed IgG antibody production from primary B cell differentiation in vitro via a TGF-β-dependent mechanism. Unlike conventional CD19-CAR CD8+ T cells, CD19-CAR Tregs suppressed antibody production in immunodeficient mice that were reconstituted with hPBMCs with reducing the risk of graft-versus-host disease. Therefore, the adoptive transfer of CD19-CAR Tregs may provide a novel therapeutic method for treating autoantibody-mediated autoimmune diseases.
Authors
Yuki Imura, Makoto Ando, Taisuke Kondo, Minako Ito, Akihiko Yoshimura
Abstract
Genetic or acquired defects of the lymphatic vasculature often result in disfiguring, disabling and, occasionally, life-threatening clinical consequences. Advanced forms of lymphedema are readily diagnosed clinically, but more subtle presentations often require invasive imaging or other technologies for a conclusive diagnosis. On the other hand, lipedema, a chronic lymphatic microvascular disease with pathological accumulation of subcutaneous adipose tissue is often misdiagnosed as obesity or lymphedema; currently there are no biomarkers or imaging criteria available for a conclusive diagnosis. Recent evidence suggests that otherwise asymptomatic defective lymphatic vasculature likely contributes to an array of other pathologies, including obesity, inflammatory bowel disease and neurological disorders, among others. Accordingly, identification of biomarkers of lymphatic malfunction will provide a valuable resource for the diagnosis and clinical discrimination of lymphedema, lipedema, obesity and other potential lymphatic-related pathologies. In this paper we profiled and compared blood plasma exosomes isolated from mouse models and from human subjects with and without symptomatic lymphatic pathologies. We identified platelet factor 4 (PF4/CXCL4) as a biomarker that could be used to diagnose lymphatic vasculature dysfunction. Furthermore, we determined that PF4 levels in circulating blood plasma exosomes were also elevated in lipedema patients, supporting current claims arguing that at least some of the underlying attributes of this disease are also the consequence of lymphatic defects.
Authors
Wanshu Ma, Hyea Jin Gil, Noelia Escobedo, Alberto Benito-Martín, Pilar Ximénez-Embún, Javier Muñoz, Héctor Peinado, Stanley G. Rockson, Guillermo Oliver
Abstract
Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder caused by reduced expression of the survival motor neuron (SMN) protein. SMN has key functions in multiple RNA pathways, including the biogenesis of small nuclear ribonucleoproteins (snRNPs) that are essential components of both major (U2-dependent) and minor (U12-dependent) spliceosomes. Here we investigated the specific contribution of U12 splicing dysfunction to SMA pathology through selective restoration of this RNA pathway in mouse models of varying phenotypic severity. We show that viral-mediated delivery of minor snRNA genes specifically improves select U12 splicing defects induced by SMN deficiency in cultured mammalian cells as well as in the spinal cord and dorsal root ganglia of SMA mice without increasing SMN expression. This approach resulted in a moderate amelioration of several parameters of the disease phenotype in SMA mice including survival, weight gain and motor function. Importantly, minor snRNA gene delivery improved aberrant splicing of the U12 intron-containing gene Stasimon and rescued the severe loss of proprioceptive sensory synapses on SMA motor neurons, which are early signatures of motor circuit dysfunction in mouse models. Taken together, these findings establish the direct contribution of U12 splicing dysfunction to synaptic deafferentation and motor circuit pathology in SMA.
Authors
Erkan Y. Osman, Meaghan Van Alstyne, Pei-Fen Yen, Francesco Lotti, Zhihua Feng, Karen K.Y. Ling, Chien-Ping Ko, Livio Pellizzoni, Christian L. Lorson
Abstract
Increased microvascular leakage is a cardinal feature of many critical diseases. Regular exercise is associated with improved endothelial function and reduced risk of cardiovascular disease. Irisin, secreted during exercise, contributes to many health benefits of exercise. However, the effects of irisin on endothelial function and microvascular leakage remain unknown. In this study, we found that irisin remarkably strengthened endothelial junctions and barrier function via binding to integrin αVβ5 receptor in LPS-treated endothelial cells. The beneficial effect of irisin was associated with suppression of the Src-MLCK-β-catenin pathway, activation of the AMPK-Cdc42/Rac1 pathway and improvement of mitochondrial function. In preclinical models of microvascular leakage, exogenous irisin improved pulmonary function, decreased lung edema and injury, suppressed inflammation, and increased survival. In ARDS patients, serum irisin levels were decreased and inversely correlated with disease severity and mortality. In conclusion, irisin enhances endothelial barrier function and mitigates microvascular leakage related diseases.
Authors
Jianbin Bi, Jia Zhang, Yifan Ren, Zhaoqing Du, Yuanyuan Zhang, Chang Liu, Yawen Wang, Lin Zhang, Zhihong Shi, Zheng Wu, Yi Lv, Rongqian Wu
Abstract
Apelin is a well-established mediator of survival and mitogenic signalling through apelin receptor (Aplnr) and have been implicated in various cancers, however little is known regarding Elabela (ELA/APELA) signalling, also mediated by Aplnr, and its role and the role of the conversion of its precursor proELA into mature ELA in cancer are unknown. Here we identify a function of mTORC1 signalling as an essential mediator of ELA that represses kidney tumour cells growth, migration and survival. Moreover, sunitinib and ELA show synergistic effect in repressing tumour growth and angiogenesis in mice. The use of site directed mutagenesis and pharmacologic experiments provide evidence that the alteration of the cleavage site of proELA by Furin induced improved ELA anti-tumorigenic activity. Finally, cohort of tumours and public data sets revealed that ELA is only repressed in the main human kidney cancer subtypes namely clear cell, papillary, and chromophobe renal cell carcinoma. While Aplnr is expressed by various kidney cells, ELA is generally expressed by epithelial cells. Collectively, these results show the tumour-suppressive role of mTORC1 signalling mediated by ELA and establish the potential use of ELA or derivatives in kidney cancers treatment.
Authors
Fabienne Soulet, Clement Bodineau, Katarzyna B. Hooks, Jean Descarpentrie, Isabel D. Alves, Marielle Dubreuil, Amandine Mouchard, Malaurie Eugenie, Jean-Luc Hoepffner, José Javier Lopez, Juan A. Rosado, Isabelle Soubeyran, Mercedes Tomé, Raúl V. Durán, Macha Nikolski, Bruno O. Villoutreix, Serge Evrard, Geraldine Siegfried, Abdel-Majid Khatib
Abstract
Background Identifying immune correlates of COVID-19 disease severity is an urgent need for clinical management, vaccine evaluation and drug development. Here we present a temporal analysis of key immune mediators, cytokine and chemokines in blood of hospitalised COVID-19 patients from serial sampling and follow up over four weeks. Methods A total of 71 patients with laboratory-confirmed COVID-19 admitted to Beijing You’an hospital in China with either mild (53 patients) or severe disease (18 patients) were enrolled with 18 healthy volunteers. We measured 34 immune mediators, cytokines and chemokines in peripheral blood every 4-7 days over one month per patient using a bio-plex multiplex immunoassay. Results We found that the chemokine RANTES(CCL5) was significantly elevated, from an early stage of the infection, in patients with mild but not severe disease. We also found that early production of inhibitory mediators including IL-10 and IL-1RA were significantly associated with disease severity, and a combination of CCL5, IL-1Ra and IL-10 at week 1 may predict patient outcomes. The majority of cytokines that are known to be associated with the cytokine storm in virus infections such as IL-6 and IFN-gamma were only significantly elevated in the late stage of severe COVID-19 illness. TNF- alpha and GM-CSF showed no significant differences between severe and mild cases. Conclusion Together our data suggest early intervention to increase expression of CCL5 may prevent patients from developing severe illness. Our data also suggest that measurement of levels of CCL5, as well as IL-1Ra, IL-10 in blood individually and in combination might be useful prognostic bio-markers to guide treatment strategies.
Authors
Yan Zhao, Ling Qin, Ping Zhang, Kang Li, Lianchun Liang, Jianping Sun, Bin Xu, Yanchao Dai, Xuemei Li, Chi Zhang, Yanchun Peng, Yingmei Feng, Ang Li, Zhongjie Hu, Haiping Xiang, Graham Ogg, Ling-Pei Ho, Andrew J. McMichael, Ronghua Jin, Julian C. Knight, Tao Dong, Yonghong Zhang
Abstract
BACKGROUND. Dysregulation of L-arginine metabolism has been proposed to occur in severe asthma patients. The effects of L-arginine supplementation on L-arginine metabolite profiles in these patients is unknown. We hypothesized that severe asthmatics with low fractional exhaled nitric oxide (FeNO) would have fewer asthma exacerbations with the addition of L-arginine to their standard asthma medications compared to placebo and would demonstrate the greatest changes in metabolite profiles. METHODS. Participants were enrolled in a single-center, cross-over, double-blinded, L-arginine intervention trial at the University of California-Davis (NCT01841281). Subjects received placebo or L-arginine, dosed orally at 0.05mg/kg (ideal body weight) twice daily. The primary endpoint was moderate asthma exacerbations. Longitudinal plasma metabolite levels were measured using mass spectrometry. A linear mixed-effect model with subject-specific intercepts was used for testing treatment effects. RESULTS. A cohort of 50 subjects was included in the final analysis. L-arginine did not significantly decrease asthma exacerbations in the overall cohort. Higher citrulline levels and a lower arginine availability index (AAI) were associated with higher FeNO (P-value = 0.005 and 2.51 x 10–9 respectively). Higher AAI was associated with lower exacerbation events. The eicosanoid prostaglandin H2 (PGH2) and Nα-Acetyl-L-arginine were found to be good predictors for differentiating clinical responders and non-responders. CONCLUSIONS. There was no statistically significant decrease in asthma exacerbations in the overall cohort with L-arginine intervention. PGH2, Nα-Acetyl-L-arginine and the AAI could serve as predictive biomarkers in future clinical trials that intervene in the arginine metabolome.
Authors
Shu-Yi Liao, Megan R. Showalter, Angela L. Linderholm, Lisa M. Franzi, Celeste Kivler, Yao Li, Michael R. Sa, Zachary A. Kons, Oliver Fiehn, Lihong Qi, Amir A. Zeki, Nicholas J. Kenyon
Activation of CAR and non-CAR T cells within the tumor microenvironment following CAR T-cell therapy
Abstract
The mechanisms of CAR-T cell mediated anti-tumor immunity and toxicity remain poorly characterized due to few studies examining the intact tumor microenvironment (TME) following CAR T-cell infusion. Axicabtagene ciloleucel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for patients with large B-cell lymphoma. We devised multiplex immunostaining and in-situ hybridization assays to interrogate CAR T cells and other immune cell infiltrates in biopsies of diffuse large B-cell lymphoma following axicabtagene ciloleucel infusion. We found a majority of intratumoral CAR T cells expressed markers of T-cell activation but, unexpectedly, comprised ≤ 5% of all T cells within the TME five days or more after therapy. T cells lacking CAR (non-CAR T cells) were also activated within the TME after axicabtagene ciloleucel infusion, being positive for Ki-67, interferon-γ, granzyme B and/or PD-1, and highest in biopsies with CAR T cells. Additionally, non-CAR immune cells were the exclusive source of IL-6, a cytokine associated with cytokine release syndrome, and highest in biopsies with CAR T cells. These data indicate that intratumoral CAR T cells are associated with generalized immune cell activation within the TME with both beneficial and pathological effects.
Authors
Pei-Hsuan Chen, Mikel Lipschitz, Jason L. Weirather, Caron Jacobson, Philippe Armand, Kyle Wright, F. Stephen Hodi, Zachary J. Roberts, Stuart A. Sievers, John Rossi, Adrian Bot, William Y. Go, Scott J. Rodig
No posts were found with this tag.
