Research
Abstract
Wound repair following acute injury requires a coordinated inflammatory response. Type I interferon (IFN) signaling is important for regulating the inflammatory response post- skin injury. IFN kappa (IFNκ), a type I IFN, has recently been found to drive skin inflammation in lupus and psoriasis; however, the role of IFNκ in the context of normal or dysregulated wound healing is unclear. Here, we found that Infκ expression is upregulated in keratinocytes early post-injury and is essential for normal tissue repair. Under diabetic conditions, IFNκ was decreased in wound keratinocytes, and early inflammation was impaired. Further, we found that the histone methyltransferase MLL1 is upregulated early following injury and regulates Infκ expression in diabetic wound keratinocytes via an H3K4me3 mediated mechanism. Using a series of in vivo studies with a genetically engineered mouse model (Mll1fl/fl K14cre-) and human wound tissues from patients with T2D, we demonstrate that MLL1 controls wound keratinocyte-mediated Infκ and MLL1 is decreased in T2D keratinocytes. Importantly, we find the administration of IFNκ early following injury improves diabetic tissue repair through increasing early inflammation, collagen deposition, and re-epithelialization. These findings have significant implications for understanding the complex role type I interferons play in keratinocytes in normal and diabetic wound healing. Additionally, they suggest IFNκ may be a viable therapeutic target to improve diabetic wound repair.
Authors
Sonya J. Wolf, Christopher O. Audu, Amrita Joshi, Aaron D. denDekker, William J. Melvin, Frank M. Davis, Xianying Xing, Rachael Wasikowski, Lam Tsoi, Steven Kunkel, Johann E. Gudjonsson, Mary X. O'Riordan, J. Michelle Kahlenberg, Katherine A. Gallagher
Abstract
Post-exertional malaise (PEM) is a hallmark symptom of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). We monitored the evolution of 1,157 plasma metabolites in 60 ME/CFS cases (45 females, 15 males) and in 45 matched healthy control subjects (30 females, 15 males) before and after two maximal Cardiopulmonary Exercise Test (CPET) challenges separated by 24 hours, with the intent of provoking PEM in patients. Four timepoints allowed exploration of the metabolic response to maximal energy-producing capacity and the recovery pattern of ME/CFS cases compared to the healthy control group. Baseline comparison identified several significantly different metabolites, along with an enriched percentage of yet-to-be identified compounds. Additionally, temporal measures demonstrated an increased metabolic disparity between cohorts, including unknown metabolites. The effects of exertion in the ME/CFS cohort predominantly highlighted lipid- as well as energy-related pathways and chemical structure clusters, which were disparately affected by the first and second exercise sessions. The 24-hour recovery period was distinct in the ME/CFS cohort, with over a quarter of the identified pathways statistically different. The pathways that are uniquely different 24 hours after an exercise challenge provide clues to metabolic disruptions that lead to PEM. Numerous altered pathways were observed to depend on glutamate metabolism, a crucial component to the homeostasis of many organs in the body, including the brain.
Authors
Arnaud Germain, Ludovic Giloteaux, Geoffrey E. Moore, Susan M. Levine, John K. Chia, Betsy A. Keller, Jared Stevens, Carl J. Franconi, Xiangling Mao, Dikoma C. Shungu, Andrew Grimson, Maureen R. Hanson
Abstract
Arterial stiffness predicts cardiovascular disease and all-cause mortality but its treatment remains challenging. Mice treated with angiotensin-II (Ang-II) develop hypertension, arterial stiffness, vascular dysfunction, and a downregulation of Rho-related BTB domain-containing protein 1 (RhoBTB1) in the vasculature. RhoBTB1 is associated with blood pressure regulation but its function is poorly understood. We tested the hypothesis that restoring RhoBTB1 can attenuate arterial stiffness, hypertension, and vascular dysfunction in Ang-II-treated mice. Genetic complementation of RhoBTB1 in the vasculature was achieved utilizing mice expressing a tamoxifen-inducible, smooth muscle-specific RhoBTB1 transgene. RhoBTB1 restoration efficiently and rapidly alleviated arterial stiffness, but not hypertension or vascular dysfunction. Mechanistic studies revealed that RhoBTB1 had no substantial effect on several classical arterial stiffness contributors such as collagen deposition, elastin content, and vascular smooth muscle remodeling. Instead, Ang-II increased actin polymerization in the aorta which was reversed by RhoBTB1. Changes in the levels of two regulators of actin polymerization, Cofilin and Vasodilator Stimulated Phosphoprotein (VASP), in response to RhoBTB1 were consistent with an actin depolymerization mechanism. Our study reveals an important function of RhoBTB1 and demonstrates its vital role in antagonizing established arterial stiffness and further supports a functional and mechanistic separation between hypertension, vascular dysfunction, and arterial stiffness.
Authors
Shi Fang, Jing Wu, John J. Reho, Ko-Ting Lu, Daniel T. Brozoski, Gaurav Kumar, Alec M. Werthman, Sebastiao Donato Silva Jr, Patricia C. Muskus Veitia, Kelsey K. Wackman, Angela J Mathison, Bi Qing Teng, Chien-Wei Lin, Frederick W. Quelle, Curt D. Sigmund
Abstract
The lung airways are constantly exposed to inhaled toxic substances, resulting in cellular damage that is repaired by local expansion of resident bronchiolar epithelial club cells. Disturbed bronchiolar epithelial damage repair lays at the core of many prevalent lung diseases including chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis, and lung cancer. However, it is still not known how bronchiolar club cell energy-metabolism contributes to this process. Here we show that Adipose TriGlyceride Lipase (ATGL), the rate-limiting enzyme for intracellular lipolysis, is critical for normal club cell function in mice. Deletion of the gene encoding ATGL, Pnpla2 (Atgl), induced substantial triglyceride accumulation, decreased mitochondrial numbers and decreased mitochondrial respiration in club cells. This defect manifested as bronchiolar epithelial thickening and increased airway resistance under baseline conditions. After naphthalene induced epithelial denudation, a regenerative defect was apparent. Mechanistically, dysfunctional PPARα lipid-signaling underlies this phenotype because, (i) ATGL was needed for PPARα lipid-signalling in regenerating bronchioles, and (ii) administration of the specific PPARα agonist WY14643 restored normal bronchiolar club cell ultrastructure and regenerative potential. Our data emphasize the importance of the cellular energy-metabolism for lung epithelial regeneration and highlight the significance of ATGL mediated lipid catabolism for lung health.
Authors
Manu Manjunath Kanti, Isabelle Striessnig-Bina, Beatrix I. Wieser, Silvia Schauer, Gerd Leitinger, Thomas O. Eichmann, Martina Schweiger, Margit Winkler, Elke Winter, Andrea Lana, Iris Kufferath, Leigh M. Marsh, Grazyna Kwapiszewska, Rudolf Zechner, Gerald Hoefler, Paul W. Vesely
Abstract
Uveal melanoma (UM) represents a unique disease in that patients with primary UM are well stratified based on their risk of developing metastasis yet there are limited effective treatments once metastases occur. There is an urgent need to better understand the distinct molecular pathogenesis of UM and characteristics of patients at high risk for metastasis, to identify neo-antigenic targets which can be used in immunotherapy, and develop novel therapeutic strategies that may effectively target this lethal transition. An important and overlooked area of molecular pathogenesis and neoantigenic targets in UM come from human endogenous retroviruses (HERVs). We investigated the HERV expression landscape in primary UM and found that tumors stratified into four HERV-based subsets that provide clear delineation of risk outcome and support subtypes identified by other molecular indicators. Specific HERV loci are associated with the risk of uveal melanoma metastasis and may offer mechanistic insights into this process, including dysregulation of HERVs on chromosomes 3 and 8. A HERV signature comprised of 17 loci was sufficient to classify tumors according to subtype with >95% accuracy, including at least one intergenic HERV with coding potential (HERVE_Xp11.23) that could represent a new potential HERV E target for immunotherapy.
Authors
Matthew L. Bendall, Jasmine H. Francis, Alexander N. Shoushtari, Douglas F. Nixon
Abstract
Binding of the bromodomain and extra-terminal domain proteins (BETs) to acetylated histone residues is critical for gene transcription. This study sought to determine the anti-fibrotic efficacy and potential mechanisms of BET inhibition in systemic sclerosis (SSc). Blockade of BETs was done using a pan BET inhibitor JQ1, BRD2 inhibitor BIC1, or BRD4 inhibitors AZD5153 or ARV825. BET inhibition, specifically BRD4 blockade, showed anti-fibrotic effects in an animal model of scleroderma and in patient-derived diffuse cutaneous (dc)SSc fibroblasts. Transcriptome analysis of JQ1-treated dcSSc fibroblasts revealed differentially expressed genes related to extracellular matrix, cell cycle, and calcium signaling. The anti-fibrotic effect of BRD4 inhibition was at least in part mediated by downregulation of Ca2+/calmodulin-dependent protein kinase II α (CaMKII-α) and reduction of intracellular calcium concentrations. These results suggest that targeting calcium pathways or BRD4 might be novel therapeutic approaches for progressive tissue fibrosis.
Authors
Sirapa Vichaikul, Mikel Gurrea-Rubio, M. Asif Amin, Phillip L. Campbell, Qi Wu, Megan N. Mattichak, William D. Brodie, Pamela J. Palisoc, Mustafa Ali, Sei Muraoka, Jeffrey H. Ruth, Ellen N. Model, Dallas M. Rohraff, Jonatan L. Hervoso, Yang Mao-Draayer, David A. Fox, Dinesh Khanna, Amr H. Sawalha, Pei-Suen Tsou
Abstract
Long-term impairment in T cell mediated adaptive immunity is a major clinical obstacle following treatment of blood disorders with Hematopoietic Stem Cell Transplantation (HSCT). Though T cell development in the thymus has been extensively characterized, there are significant gaps in our understanding of pre-thymic processes which influence early T cell potential. We have uncovered a Notch-IL21 signaling axis in Bone Marrow (BM) Common Lymphoid Progenitor (CLP) cells. IL21r expression is driven by Notch activation in CLPs, and in vivo treatment with IL21 induces Notch-dependent CLP proliferation. Taking advantage of this novel signaling axis, we have generated T cell progenitors ex vivo which better repopulate the thymus and peripheral lymphoid organs of mice in an allogeneic transplant model. Importantly, Notch and IL21 activation is equally effective in the priming and expansion of human Cord Blood (CB) cells toward the T cell fate, confirming the translational potential of the combined treatment.
Authors
Kilian Sottoriva, Na Yoon Paik, Zachary White, Thilinie Bandara, Lijian Shao, Teruyuki Sano, Kostandin Pajcini
Abstract
Transplant recipients exhibit an impaired protective immunity after SARS-CoV-2 vaccination, potentially caused by mycophenolate (MPA) immunosuppression. Recent data from autoimmune patients suggest that temporary MPA hold might significantly improve booster vaccination outcomes. We applied a fourth dose of SARS-CoV-2 vaccine to 29 kidney transplant recipients during temporary (5 weeks) MPA (n=28)/azathioprine (n=1) hold, who had not mounted a humoral immune-response to previous vaccinations. Seroconversion until day 32 after vaccination was observed in 76% of patients, associated with acquisition of virus neutralizing capacity. Interestingly, 21/25 (84%) CNI-treated patients responded, but only 1/4 Belatacept-treated patients. In line with humoral responses, counts and relative frequencies of spike receptor binding domain (RBD) specific B cells were significantly increased on day 7 after vaccination, with an increase in RBD specific CD27++CD38+ plasmablasts. Whereas overall proportions of spike-reactive CD4+ T cells remained unaltered after the fourth dose, frequencies were positively correlated with specific IgG levels. Importantly, antigen-specific proliferating Ki67+ and in vivo activated PD1+ T cells significantly increased after re-vaccination during MPA hold, whereas cytokine production and memory differentiation remained unaffected. In summary, antimetabolite hold augmented all arms of immunity during booster vaccination. These data suggest further studies of MMF hold in KTR.
Authors
Eva Schrezenmeier, Hector Rincon-Arevalo, Annika Jens, Ana-Luisa Stefanski, Charlotte Hammett, Bilgin Osmanodja, Nadine Koch, Bianca Zukunft, Julia Beck, Michael Oellerich, Vanessa Pross, Carolin Stahl, Mira Choi, Friederike Bachmann, Lutz Liefeldt, Petra Glander, Ekkehard Schütz, Kirsten Bornemann-Kolatzki, Covadonga López del Moral, Hubert Schrezenmeier, Carolin Ludwig, Bernd Jahrsdörfer, Kai-Uwe Eckardt, Nils Lachmann, Katja Kotsch, Thomas Dörner, Fabian Halleck, Arne Sattler, Klemens Budde
Abstract
The bromodomain and extraterminal (BET) family of chromatin reader proteins bind to acetylated histones and regulate gene expression. The development of BET inhibitors (BETi) has expanded our knowledge of BET protein function beyond transcriptional regulation and has ushered several prostate cancer (PCa) clinical trials. However, BETi as a single-agent is not associated with anti-tumor activity in castration-resistant prostate cancer (CRPC) patients. We hypothesized that novel combinatorial strategies are likely to enhance the efficacy of BETi. Prior studies by our group and others have shown that BET proteins are essential for the repair of DNA double-strand breaks (DSBs) by the non-homologous end joining (NHEJ) as well as the homologous recombination (HR) DNA repair pathways. By using PCa patient‐derived explants (PDEs) and xenograft models, we show that BETi treatment enhances the efficacy of radiation therapy (RT) and also overcomes radioresistance. Mechanistically, BETi potentiates the activity of RT by blocking the repair of DNA DSBs. We also report a synthetic lethal relationship between BETi and Topoisomerase I (TOP1) inhibitors (TOP1i). We show that the BETi, OTX015, synergizes with the new class of synthetic non-camptothecin TOP1i, LMP400 (indotecan), to block tumor growth in aggressive CRPC xenograft models. Mechanistically, BETi potentiates the anti-tumor activity of TOP1i by disrupting replication fork stability. Longitudinal analysis of patient tumors indicated that TOP1 transcript abundance increased as patients progressed from hormone-sensitive prostate cancer (HSPC) to CRPC. Consistent with this observation, TOP1 was highly expressed in metastatic CRPC (mCRPC) and its expression correlated with the expression of BET family genes—BRD4, BRD3 and BRD2. These studies open new avenues for the rational combinatorial treatment of aggressive PCa—particularly, cancers refractory to androgen signaling inhibitors.
Authors
Xiangyi Li, GuemHee Baek, Suzanne Carreira, Wei Yuan, Shihong Ma, Mia Hofstad, Sora Lee, Yunpeng Gao, Claudia Bertan, Maria de los Dolores Fenor de la Maza, Prasanna G. Alluri, Sandeep Burma, Benjamin P.C. Chen, Ganesh V. Raj, Johann de Bono, Yves Pommier, Ram S. Mani
Abstract
BACKGROUND. HIV-1 vaccine efforts are primarily directed towards eliciting neutralizing antibodies (nAbs). However, vaccine trials and mother to child natural history cohort investigations indicate that antibody-dependent cellular cytotoxicity (ADCC), not nAbs, correlate with prevention. The ADCC characteristics associated with lack of HIV-1 acquisition remain unclear. METHODS. Here we examine ADCC and nAb properties in pre-transmission plasma from HIV-1 exposed infants and from the corresponding transmitting and non-transmitting mothers’ breast milk and plasma. Breadth and potency (BP) is assessed against a panel of heterologous, non-maternal, variants. ADCC and neutralization sensitivity is estimated for the strains present in the infected mothers. RESULTS. Infants that eventually acquire HIV-1 and those that remain uninfected have similar pre-transmission ADCC BP. The viruses circulating in the transmitting and the non-transmitting mothers also have similar ADCC susceptibility. Infants with a combination of higher pre-transmission ADCC BP and exposure to more ADCC susceptible strains are less likely to acquire HIV-1. In contrast, higher pre-existing infant neutralization BP and greater maternal virus neutralization sensitivity does not associate with transmission. Infants have higher ADCC BP closer to birth and in the presence of high plasma IgG relative to IgA levels. Mothers with potent humoral responses against their autologous viruses harbor more ADCC sensitive strains. CONCLUSION. ADCC sensitivity of the exposure variants along with preexisting ADCC BP influence mother to child HIV-1 transmission during breastfeeding. Vaccination strategies that enhance ADCC responses are likely not sufficient to prevent HIV-1 transmission because strains present in chronically infected individuals can have low ADCC susceptibility. TRIAL REGISTRATION. NCT00164736 for BAN study
Authors
Allison S. Thomas, Carolyn Coote, Yvetane Moreau, John E. Isaac, Alexander C. Ewing, Athena P. Kourtis, Manish Sagar
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