Issue published October 10, 2022
- Volume 7, Issue 19
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Seaman et al. report that vaccine breakthrough infection with SARS-CoV-2 enhances the magnitude and breadth of neutralizing antibody titers in a viral genotype-specific manner. Image credit: Design_Cells/Shutterstock.
On the cover: Vaccine breakthrough infection leads to variant-dependent neutralizing responses
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Research Articles
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Allele-specific silencing of the gain-of-function mutation in Huntington’s disease using CRISPR/Cas9
Abstract
Dominant gain-of-function mechanisms in Huntington’s disease (HD) suggest that selective silencing of mutant HTT produces robust therapeutic benefits. Here, capitalizing on exonic protospacer adjacent motif–altering (PAM-altering) SNP (PAS), we developed an allele-specific CRISPR/Cas9 strategy to permanently inactivate mutant HTT through nonsense-mediated decay (NMD). Comprehensive sequence/haplotype analysis identified SNP-generated NGG PAM sites on exons of common HTT haplotypes in HD subjects, revealing a clinically relevant PAS-based mutant-specific CRISPR/Cas9 strategy. Alternative allele of rs363099 (29th exon) eliminates the NGG PAM site on the most frequent normal HTT haplotype in HD, permitting mutant-specific CRISPR/Cas9 therapeutics in a predicted ~20% of HD subjects with European ancestry. Our rs363099-based CRISPR/Cas9 showed perfect allele specificity and good targeting efficiencies in patient-derived cells. Dramatically reduced mutant HTT mRNA and complete loss of mutant protein suggest that our allele-specific CRISPR/Cas9 strategy inactivates mutant HTT through NMD. In addition, GUIDE-Seq analysis and subsequent validation experiments support high levels of on-target gene specificity. Our data demonstrate a significant target population, complete mutant specificity, decent targeting efficiency in patient-derived cells, and minimal off-target effects on protein-coding genes, proving the concept of PAS-based allele-specific NMD-CRISPR/Cas9 and supporting its therapeutic potential in HD.
Authors
Jun Wan Shin, Eun Pyo Hong, Seri S. Park, Doo Eun Choi, Ihn Sik Seong, Madelynn N. Whittaker, Benjamin P. Kleinstiver, Richard Z. Chen, Jong-Min Lee
×Abstract
Clinical studies of cancer patients have shown that overexpression or amplification of thymidylate synthase (TS) correlates with a worse clinical outcome. We previously showed that elevated TS exhibits properties of an oncogene and promotes pancreatic neuroendocrine tumors (PanNETs) with a long latency. To study the causal impact of elevated TS levels in PanNETs, we generated a mouse model with elevated human TS (hTS) and conditional inactivation of the Men1 gene in pancreatic islet cells (hTS/Men1–/–). We demonstrated that increased hTS expression was associated with earlier tumor onset and accelerated PanNET development in comparison with control Men1–/– and Men1+/ΔN3-8 mice. We also observed a decrease in overall survival of hTS/Men1+/– and hTS/Men1–/– mice as compared with control mice. We showed that elevated hTS in Men1-deleted tumor cells enhanced cell proliferation, deregulated cell cycle kinetics, and was associated with a higher frequency of somatic mutations, DNA damage, and genomic instability. In addition, we analyzed the survival of 88 patients with PanNETs and observed that high TS protein expression independently predicted worse clinical outcomes. In summary, elevated hTS directly participates in promoting PanNET tumorigenesis with reduced survival in Men1-mutant background. This work will refocus attention on new strategies to inhibit TS activity for PanNET treatment.
Authors
Vinod Vijayakurup, Kyungah Maeng, Hye Seung Lee, Benjamin Meyer, Sandra Burkett, Akbar Nawab, Michael W. Dougherty, Christian Jobin, Iqbal Mahmud, Timothy J. Garrett, Michael Feely, Kyoung Bun Lee, Frederic J. Kaye, Maria V. Guijarro, Maria Zajac-Kaye
×Abstract
A high-fat diet (HFD) contributes to the increased incidence of colorectal cancer, but the mechanisms are unclear. We found that R-spondin 3 (Rspo3), a ligand for leucine-rich, repeat-containing GPCR 4 and 5 (LGR4 and LGR5), was the main subtype of R-spondins and was produced by myofibroblasts beneath the crypts in the intestine. HFD upregulated colonic Rspo3, LGR4, LGR5, and β-catenin gene expression in specific pathogen–free rodents, but not in germ-free mice, and the upregulations were prevented by the bile acid (BA) binder cholestyramine or antibiotic treatment, indicating mediation by both BA and gut microbiota. Cholestyramine or antibiotic treatments prevented HFD-induced enrichment of members of the Lachnospiraceae and Rumincoccaceae, which can transform primary BA into secondary BA. Oral administration of deoxycholic acid (DCA), or inoculation of a combination of the BA deconjugator Lactobacillus plantarum and 7α-dehydroxylase–containing Clostridium scindens with an HFD to germ-free mice increased serum DCA and colonic Rspo3 mRNA levels, indicating that formation of secondary BA by gut microbiota is responsible for HFD-induced upregulation of Rspo3. In primary myofibroblasts, DCA increased Rspo3 mRNA via TGR5. Finally, we showed that cholestyramine or conditional deletion of Rspo3 prevented HFD- or DCA-induced intestinal proliferation. We conclude that secondary BA is responsible for HFD-induced upregulation of Rspo3, which, in turn, mediates HFD-induced intestinal epithelial proliferation.
Authors
Ji-Yao Li, Merritt Gillilland III, Allen A. Lee, Xiaoyin Wu, Shi-Yi Zhou, Chung Owyang
×Abstract
Thy-1 (CD90) is a well-known marker of fibroblasts implicated in organ fibrosis, but its contribution to skin fibrosis remains unknown. We examined Thy-1 expression in scleroderma skin and its potential role as a biomarker and pathogenic factor in animal models of skin fibrosis. Skin from patients with systemic sclerosis demonstrated markedly elevated Thy-1 expression compared with controls, colocalized with fibroblast activator protein in the deep dermis, and correlated with the severity of skin involvement (modified Rodnan skin score). Serial imaging of skin from Thy-1 yellow fluorescent protein reporter mice by IVIS showed an increase in Thy-1 expression that correlated with onset and progression of fibrosis. In contrast to lung fibrosis, Thy-1–KO mice had attenuated skin fibrosis in both bleomycin and tight skin-1 murine models. Moreover, Thy-1 regulated key pathogenic pathways involved in fibrosis, including inflammation, myofibroblast differentiation, apoptosis, and multiple additional canonical fibrotic pathways. Therefore, although Thy-1 deficiency leads to exacerbated lung fibrosis, in skin it is protective. Moreover, Thy-1 may serve as a longitudinal marker to assess skin fibrosis.
Authors
Roberta G. Marangoni, Poulami Datta, Ananta Paine, Stacey Duemmel, Marc Nuzzo, Laura Sherwood, John Varga, Christopher Ritchlin, Benjamin D. Korman
×Abstract
The (Pro)renin receptor ([P]RR), also known as ATP6AP2, is a single-transmembrane protein that is implicated in a multitude of biological processes. However, the exact role of ATP6AP2 during blood vessel development remains largely undefined. Here, we use an inducible endothelial cell–specific (EC-specific) Atp6ap2-KO mouse model to investigate the role of ATP6AP2 during both physiological and pathological angiogenesis in vivo. We observed that postnatal deletion of Atp6ap2 in ECs results in cell migration defects, loss of tip cell polarity, and subsequent impairment of retinal angiogenesis. In vitro, Atp6ap2-deficient ECs similarly displayed reduced cell migration, impaired sprouting, and defective cell polarity. Transcriptional profiling of ECs isolated from Atp6ap2 mutant mice further indicated regulatory roles in angiogenesis, cell migration, and extracellular matrix composition. Mechanistically, we provided evidence that expression of various extracellular matrix components is controlled by ATP6AP2 via the ERK pathway. Furthermore, Atp6ap2-deficient retinas exhibited reduced revascularization in an oxygen-induced retinopathy model. Collectively, our results demonstrate a critical role of ATP6AP2 as a regulator of developmental and pathological angiogenesis.
Authors
Nehal R. Patel, Rajan K C, Avery Blanks, Yisu Li, Minolfa C. Prieto, Stryder M. Meadows
×Abstract
The liver regulates energy partitioning and use in a sex-dependent manner, coupling hepatic substrate availability to female reproductive status. Fibroblast growth factor 21 (FGF21) is a hepatokine produced in response to metabolic stress that adaptively directs systemic metabolism and substrate use to reduce hepatic lipid storage. Here we report that FGF21 altered hepatic transcriptional and metabolic responses, and reduced liver triglycerides, in a sex-dependent manner. FGF21 decreased hepatic triglycerides in obese male mice in a weight loss–independent manner; this was abrogated among female littermates. The effect of FGF21 on hepatosteatosis is thought to derive, in part, from increased adiponectin secretion. Accordingly, plasma adiponectin and its upstream adrenergic receptor → cAMP → exchange protein directly activated by cAMP signaling pathway was stimulated by FGF21 in males and inhibited in females. Both ovariectomized and reproductively senescent old females responded to FGF21 treatment by decreasing body weight, but liver triglycerides and adiponectin remained unchanged. Thus, the benefit of FGF21 treatment for improving hepatosteatosis depends on sex but not on a functional female reproductive system. Because FGF21 provides a downstream mechanism contributing to several metabolic interventions, and given its direct clinical importance, these findings may have broad implications for the targeted application of nutritional and pharmacological treatments for metabolic disease.
Authors
Aki T. Chaffin, Karlton R. Larson, Kuei-Pin Huang, Chih-Ting Wu, Nadejda Godoroja, Yanbin Fang, Devi Jayakrishnan, Karla A. Soto Sauza, Landon C. Sims, Niloufar Mohajerani, Michael L. Goodson, Karen K. Ryan
×Abstract
Cellular stress contributes to the capacity of melanoma cells to undergo phenotype switching into highly migratory and drug-tolerant dedifferentiated states. Such dedifferentiated melanoma cell states are marked by loss of melanocyte-specific gene expression and increase of mesenchymal markers. Two crucial transcription factors, microphthalmia-associated transcription factor (MITF) and SRY-box transcription factor 10 (SOX10), important in melanoma development and progression, have been implicated in this process. In this study we describe that loss of MITF is associated with a distinct transcriptional program, MITF promoter hypermethylation, and poor patient survival in metastatic melanoma. From a comprehensive collection of melanoma cell lines, we observed that MITF-methylated cultures were subdivided in 2 distinct subtypes. Examining mRNA levels of neural crest–associated genes, we found that 1 subtype had lost the expression of several lineage genes, including SOX10. Intriguingly, SOX10 loss was associated with SOX10 gene promoter hypermethylation and distinct phenotypic and metastatic properties. Depletion of SOX10 in MITF-methylated melanoma cells using CRISPR/Cas9 supported these findings. In conclusion, this study describes the significance of melanoma state and the underlying functional properties explaining the aggressiveness of such states.
Authors
Adriana Sanna, Bengt Phung, Shamik Mitra, Martin Lauss, Jiyeon Choi, Tongwu Zhang, Ching-Ni Njauw, Eugenia Cordero, Katja Harbst, Frida Rosengren, Rita Cabrita, Iva Johansson, Karolin Isaksson, Christian Ingvar, Ana Carneiro, Kevin Brown, Hensin Tsao, My Andersson, Kristian Pietras, Göran Jönsson
×Abstract
Intestinal epithelial integrity is commonly disrupted in patients with critical disorders, but the exact underlying mechanisms are unclear. Long noncoding RNAs transcribed from ultraconserved regions (T-UCRs) control different cell functions and are involved in pathologies. Here, we investigated the role of T-UCRs in intestinal epithelial homeostasis and identified T-UCR uc.230 as a major regulator of epithelial renewal, apoptosis, and barrier function. Compared with controls, intestinal mucosal tissues from patients with ulcerative colitis and from mice with colitis or fasted for 48 hours had increased levels of uc.230. Silencing uc.230 inhibited the growth of intestinal epithelial cells (IECs) and organoids and caused epithelial barrier dysfunction. Silencing uc.230 also increased IEC vulnerability to apoptosis, whereas increasing uc.230 levels protected IECs against cell death. In mice with colitis, reduced uc.230 levels enhanced mucosal inflammatory injury and delayed recovery. Mechanistic studies revealed that uc.230 increased CUG-binding protein 1 (CUGBP1) by acting as a natural decoy RNA for miR-503, which interacts with Cugbp1 mRNA and represses its translation. These findings indicate that uc.230 sustains intestinal mucosal homeostasis by promoting epithelial renewal and barrier function and that it protects IECs against apoptosis by serving as a natural sponge for miR-503, thereby preserving CUGBP1 expression.
Authors
Ting-Xi Yu, Sudhakar Kalakonda, Xiangzheng Liu, Naomi Han, Hee K. Chung, Lan Xiao, Jaladanki N. Rao, Tong-Chuan He, Jean-Pierre Raufman, Jian-Ying Wang
×Abstract
The proteasome inhibitors (PIs) bortezomib and carfilzomib, which target proteasome 20S subunit beta 5 (PSMB5) in cells, are widely used in multiple myeloma (MM) treatment. In this study, we demonstrated the role of interferon-stimulated 20 kDa exonuclease-like 2 (ISG20L2) in MM PI resistance. Gain- and loss-of-function studies showed that ISG20L2 suppressed MM cell sensitivity to PIs in vitro and in vivo. Patients with ISG20L2lo MM had a better response to PIs and a longer overall survival than patients with ISG20L2hi MM. Biotinylated bortezomib pull-down assays showed that ISG20L2 competed with PSMB5 in binding to bortezomib. The surface plasmon resonance assay confirmed the direct binding of bortezomib to ISG20L2. In ISG20L2hi MM cells, ISG20L2 attenuated the binding of bortezomib to PSMB5, resulting in lower inhibition of proteasome activity and therefore less bortezomib-induced cell death. Overall, we identified a potentially novel mechanism by which ISG20L2 conferred bortezomib resistance on MM. The expression of ISG20L2 correlated with MM PI responses and patient treatment outcomes.
Authors
Yan Yang, Yuhan Gao, Jingcao Huang, Zhuang Yang, Hongmei Luo, Fangfang Wang, Juan Xu, Yushan Cui, Hong Ding, Zhimei Lin, Xinyu Zhai, Ying Qu, Li Zhang, Ting Liu, Lingqun Ye, Ting Niu, Yuhuan Zheng
×Abstract
BACKGROUND During aging, there is a functional decline in the pool of muscle stem cells (MuSCs) that influences the functional and regenerative capacity of skeletal muscle. Preclinical evidence has suggested that nicotinamide riboside (NR) and pterostilbene (PT) can improve muscle regeneration, e.g., by increasing MuSC function. The objective of this study was to investigate if supplementation with NR and PT (NRPT) promotes skeletal muscle regeneration after muscle injury in elderly individuals by improved recruitment of MuSCs.METHODS Thirty-two elderly individuals (55–80 years of age) were randomized to daily supplementation with either NRPT (1,000 mg NR and 200 mg PT) or matched placebo. Two weeks after initiation of supplementation, skeletal muscle injury was induced by electrically induced eccentric muscle work. Skeletal muscle biopsies were obtained before, 2 hours after, and 2, 8, and 30 days after injury.RESULTS A substantial skeletal muscle injury was induced by the protocol and associated with release of myoglobin and creatine kinase, muscle soreness, tissue edema, and a decrease in muscle strength. MuSC content, proliferation, and cell size revealed a large demand for recruitment after injury, but this was not affected by NRPT. Furthermore, histological analyses of muscle fiber area, central nuclei, and embryonic myosin heavy chain showed no NRPT supplementation effect.CONCLUSION Daily supplementation with 1,000 mg NR and 200 mg PT is safe but does not improve recruitment of the MuSC pool or other measures of muscle recovery in response to injury or subsequent regeneration in elderly individuals.TRIAL REGISTRATION ClinicalTrials.gov NCT03754842.FUNDING Novo Nordisk Foundation (NNF17OC0027242) and Novo Nordisk Foundation CBMR.
Authors
Jonas Brorson Jensen, Ole L. Dollerup, Andreas B. Møller, Tine B. Billeskov, Emilie Dalbram, Sabina Chubanava, Mads V. Damgaard, Ryan W. Dellinger, Kajetan Trošt, Thomas Moritz, Steffen Ringgaard, Niels Møller, Jonas T. Treebak, Jean Farup, Niels Jessen
×Abstract
New strategies that augment T cell responses are required to broaden the therapeutic arsenal against cancer. CD96, TIGIT, and CD226 are receptors that bind to a communal ligand, CD155, and transduce either inhibitory or activating signals. The function of TIGIT and CD226 is established, whereas the role of CD96 remains ambiguous. Using a panel of engineered antibodies, we discovered that the T cell stimulatory activity of anti-CD96 antibodies requires antibody cross-linking and is potentiated by Fcγ receptors. Thus, soluble “Fc silent” anti-CD96 antibodies failed to stimulate human T cells, whereas the same antibodies were stimulatory after coating onto plastic surfaces. Remarkably, the activity of soluble anti-CD96 antibodies was reinstated by engineering the Fc domain to a human IgG1 isotype, and it was dependent on antibody trans-cross-linking by FcγRI. In contrast, neither human IgG2 nor variants with increased Fcγ receptor IIB binding possessed stimulatory activity. Anti-CD96 antibodies acted directly on T cells and augmented gene expression networks associated with T cell activation, leading to proliferation, cytokine secretion, and resistance to Treg suppression. Furthermore, CD96 expression correlated with survival in HPV+ head and neck squamous cell carcinoma, and its cross-linking activated tumor-infiltrating T cells, thus highlighting the potential of anti-CD96 antibodies in cancer immunotherapy.
Authors
Anne Rogel, Fathima M. Ibrahim, Stephen M. Thirdborough, Florence Renart-Depontieu, Charles N. Birts, Sarah L. Buchan, Xavier Preville, Emma V. King, Aymen Al-Shamkhani
×Abstract
Collateral lethality occurs when loss of a gene/protein renders cancer cells dependent on its remaining paralog. Combining genome-scale CRISPR/Cas9 loss-of-function screens with RNA sequencing in over 900 cancer cell lines, we found that cancers of nervous system lineage, including adult and pediatric gliomas and neuroblastomas, required the nuclear kinase vaccinia-related kinase 1 (VRK1) for their survival in vivo. VRK1 dependency was inversely correlated with expression of its paralog VRK2. VRK2 knockout sensitized cells to VRK1 loss, and conversely, VRK2 overexpression increased cell fitness in the setting of VRK1 loss. DNA methylation of the VRK2 promoter was associated with low VRK2 expression in human neuroblastomas and adult and pediatric gliomas. Mechanistically, depletion of VRK1 reduced barrier-to-autointegration factor phosphorylation during mitosis, resulting in DNA damage and apoptosis. Together, these studies identify VRK1 as a synthetic lethal target in VRK2 promoter–methylated adult and pediatric gliomas and neuroblastomas.
Authors
Jonathan So, Nathaniel W. Mabe, Bernhard Englinger, Kin-Hoe Chow, Sydney M. Moyer, Smitha Yerrum, Maria C. Trissal, Joana G. Marques, Jason J. Kwon, Brian Shim, Sangita Pal, Eshini Panditharatna, Thomas Quinn, Daniel A. Schaefer, Daeun Jeong, David L. Mayhew, Justin Hwang, Rameen Beroukhim, Keith L. Ligon, Kimberly Stegmaier, Mariella G. Filbin, William C. Hahn
×Abstract
Gene mutations causing loss of dystrophin result in the severe muscle disease known as Duchenne muscular dystrophy (DMD). Despite efforts at genetic repair, DMD therapy remains largely palliative. Loss of dystrophin destabilizes the sarcolemmal membrane, inducing mechanosensitive cation channels to increase calcium entry and promote cell damage and, eventually, muscle dysfunction. One putative channel is transient receptor potential canonical 6 (TRPC6); we have shown that TRPC6 contributed to abnormal force and calcium stress-responses in cardiomyocytes from mice lacking dystrophin that were haplodeficient for utrophin (mdx/utrn+/– [HET] mice). Here, we show in both the HET mouse and the far more severe homozygous mdx/utrn–/– mouse that TRPC6 gene deletion or its selective pharmacologic inhibition (by BI 749327) prolonged survival 2- to 3-fold, improving skeletal and cardiac muscle and bone defects. Gene pathways reduced by BI 749327 treatment most prominently regulated fat metabolism and TGF-β1 signaling. These results support the testing of TRPC6 inhibitors in human trials for other diseases as a novel DMD therapy.
Authors
Brian L. Lin, Joseph Y. Shin, William P.D. Jeffreys, Nadan Wang, Clarisse A. Lukban, Megan C. Moorer, Esteban Velarde, Olivia A. Hanselman, Seoyoung Kwon, Suraj Kannan, Ryan C. Riddle, Christopher W. Ward, Steven S. Pullen, Antonio Filareto, David A. Kass
×Abstract
Myotonic dystrophy type 1 (DM1; MIM #160900) is an autosomal dominant disorder, clinically characterized by progressive muscular weakness and multisystem degeneration. The broad phenotypes observed in patients with DM1 resemble the appearance of an accelerated aging process. However, the molecular mechanisms underlying these phenotypes remain largely unknown. Transcriptomic analysis of fibroblasts derived from patients with DM1 and healthy individuals revealed a decrease in cell cycle activity, cell division, and DNA damage response in DM1, all of which related to the accumulation of cellular senescence. The data from transcriptome analyses were corroborated in human myoblasts and blood samples, as well as in mouse and Drosophila models of the disease. Serial passage studies in vitro confirmed the accelerated increase in senescence and the acquisition of a senescence-associated secretory phenotype in DM1 fibroblasts, whereas the DM1 Drosophila model showed reduced longevity and impaired locomotor activity. Moreover, functional studies highlighted the impact of BMI1 and downstream p16INK4A/RB and ARF/p53/p21CIP pathways in DM1-associated cellular phenotypes. Importantly, treatment with the senolytic compounds Quercetin, Dasatinib, or Navitoclax reversed the accelerated aging phenotypes in both DM1 fibroblasts in vitro and in Drosophila in vivo. Our results identify the accumulation of senescence as part of DM1 pathophysiology and, therefore, demonstrate the efficacy of senolytic compounds in the preclinical setting.
Authors
Mikel García-Puga, Ander Saenz-Antoñanzas, Gorka Gerenu, Alex Arrieta-Legorburu, Roberto Fernández-Torrón, Miren Zulaica, Amets Saenz, Joseba Elizazu, Gisela Nogales-Gadea, Shahinaz M. Gadalla, Marcos J. Araúzo-Bravo, Adolfo López de Munain, Ander Matheu
×Abstract
Intercellular communication is critical for homeostasis in mammalian systems, including the gastrointestinal (GI) tract. Exosomes are nanoscale lipid extracellular vesicles that mediate communication between many cell types. Notably, the roles of immune cell exosomes in regulating GI homeostasis and inflammation are largely uncharacterized. By generating mouse strains deficient in cell-specific exosome production, we demonstrate deletion of the small GTPase Rab27A in CD11c+ cells exacerbated murine colitis, which was reversible through administration of DC-derived exosomes. Profiling RNAs within colon exosomes revealed a distinct subset of miRNAs carried by colon- and DC-derived exosomes. Among antiinflammatory exosomal miRNAs, miR-146a was transferred from gut immune cells to myeloid and T cells through a Rab27-dependent mechanism, targeting Traf6, IRAK-1, and NLRP3 in macrophages. Further, we have identified a potentially novel mode of exosome-mediated DC and macrophage crosstalk that is capable of skewing gut macrophages toward an antiinflammatory phenotype. Assessing clinical samples, RAB27A, select miRNAs, and RNA-binding proteins that load exosomal miRNAs were dysregulated in ulcerative colitis patient samples, consistent with our preclinical mouse model findings. Together, our work reveals an exosome-mediated regulatory mechanism underlying gut inflammation and paves the way for potential use of miRNA-containing exosomes as a novel therapeutic for inflammatory bowel disease.
Authors
Kaylyn M. Bauer, Morgan C. Nelson, William W. Tang, Tyson R. Chiaro, D. Garrett Brown, Arevik Ghazaryan, Soh-Hyun Lee, Allison M. Weis, Jennifer H. Hill, Kendra A. Klag, Van B. Tran, Jacob W. Thompson, Andrew G. Ramstead, Josh K. Monts, James E. Marvin, Margaret Alexander, Warren P. Voth, W. Zac Stephens, Diane M. Ward, Aaron C. Petrey, June L. Round, Ryan M. O’Connell
×Abstract
Background Alcohol use disorder (AUD) is a chronic, relapsing brain disorder that accounts for 5% of deaths annually, and there is an urgent need to develop new targets for therapeutic intervention. The glucagon-like peptide-1 (GLP-1) receptor agonist exenatide reduces alcohol consumption in rodents and nonhuman primates, but its efficacy in patients with AUD is unknown.Methods In a randomized, double-blinded, placebo-controlled clinical trial, treatment-seeking AUD patients were assigned to receive exenatide (2 mg subcutaneously) or placebo once weekly for 26 weeks, in addition to standard cognitive-behavioral therapy. The primary outcome was reduction in number of heavy drinking days. A subgroup also completed functional MRI (fMRI) and single-photon emission CT (SPECT) brain scans.Results A total of 127 patients were enrolled. Our data revealed that although exenatide did not significantly reduce the number of heavy drinking days compared with placebo, it significantly attenuated fMRI alcohol cue reactivity in the ventral striatum and septal area, which are crucial brain areas for drug reward and addiction. In addition, dopamine transporter availability was lower in the exenatide group compared with the placebo group. Exploratory analyses revealed that exenatide significantly reduced heavy drinking days and total alcohol intake in a subgroup of obese patients (BMI > 30 kg/m2). Adverse events were mainly gastrointestinal.Conclusion This randomized controlled trial on the effects of a GLP-1 receptor agonist in AUD patients provides new important knowledge on the effects of GLP-1 receptor agonists as a novel treatment target in addiction.Trial registration EudraCT: 2016-003343-11. ClinicalTrials.gov (NCT03232112).Funding Novavi Foundation; Research Foundation, Mental Health Services, Capital Region of Denmark; Research Foundation, Capital Region of Denmark; Ivan Nielsen Foundation; A.P. Moeller Foundation; Augustinus Foundation; Woerzner Foundation; Grosserer L.F. Foghts Foundation; Hartmann Foundation; Aase and Ejnar Danielsen Foundation; P.A. Messerschmidt and Wife Foundation; and Lundbeck Foundation.
Authors
Mette Kruse Klausen, Mathias Ebbesen Jensen, Marco Møller, Nina Le Dous, Anne-Marie Østergaard Jensen, Victoria Alberte Zeeman, Claas-Frederik Johannsen, Alycia Lee, Gerda Krog Thomsen, Julian Macoveanu, Patrick MacDonald Fisher, Matthew Paul Gillum, Niklas Rye Jørgensen, Marianne Lerbæk Bergmann, Henrik Enghusen Poulsen, Ulrik Becker, Jens Juul Holst, Helene Benveniste, Nora D. Volkow, Sabine Vollstädt-Klein, Kamilla Woznica Miskowiak, Claus Thorn Ekstrøm, Gitte Moos Knudsen, Tina Vilsbøll, Anders Fink-Jensen
×Abstract
Mineralocorticoid receptor antagonists (MRAs) slow cardiomyopathy in patients with Duchenne muscular dystrophy (DMD) and improve skeletal muscle pathology and function in dystrophic mice. However, glucocorticoids, known antiinflammatory drugs, remain a standard of care for DMD, despite substantial side effects. Exact mechanisms underlying mineralocorticoid receptor (MR) signaling contribution to dystrophy are unknown. Whether MRAs affect inflammation in dystrophic muscles and how they compare with glucocorticoids is unclear. The MRA spironolactone and glucocorticoid prednisolone were each administered for 1 week to dystrophic mdx mice during peak skeletal muscle necrosis to compare effects on inflammation. Both drugs reduced cytokine levels in mdx quadriceps, but prednisolone elevated diaphragm cytokines. Spironolactone did not alter myeloid populations in mdx quadriceps or diaphragms, but prednisolone increased F4/80hi macrophages. Both spironolactone and prednisolone reduced inflammatory gene expression in myeloid cells sorted from mdx quadriceps, while prednisolone additionally perturbed cell cycle genes. Spironolactone also repressed myeloid expression of the gene encoding fibronectin, while prednisolone increased its expression. Overall, spironolactone exhibits antiinflammatory properties without altering leukocyte distribution within skeletal muscles, while prednisolone suppresses quadriceps cytokines but increases diaphragm cytokines and pathology. Antiinflammatory properties of MRAs and different limb and respiratory muscle responses to glucocorticoids should be considered when optimizing treatments for patients with DMD.
Authors
Zachary M. Howard, Chetan K. Gomatam, Charles P. Rabolli, Jeovanna Lowe, Arden B. Piepho, Shyam S. Bansal, Federica Accornero, Jill A. Rafael-Fortney
×Abstract
Protective immunity against SARS-CoV-2 infection after COVID-19 vaccination may differ by variant. We enrolled vaccinated (n = 39) and unvaccinated (n = 11) individuals with acute, symptomatic SARS-CoV-2 Delta or Omicron infection and performed SARS-CoV-2 viral load quantification, whole-genome sequencing, and variant-specific antibody characterization at the time of acute illness and convalescence. Viral load at the time of infection was inversely correlated with antibody binding and neutralizing antibody responses. Across all variants tested, convalescent neutralization titers in unvaccinated individuals were markedly lower than in vaccinated individuals. Increases in antibody titers and neutralizing activity occurred at convalescence in a variant-specific manner. For example, among individuals infected with the Delta variant, neutralizing antibody responses were weakest against BA.2, whereas infection with Omicron BA.1 variant generated a broader response against all tested variants, including BA.2.
Authors
Michael S. Seaman, Mark J. Siedner, Julie Boucau, Christy L. Lavine, Fadi Ghantous, May Y. Liew, Josh I. Mathews, Arshdeep Singh, Caitlin Marino, James Regan, Rockib Uddin, Manish C. Choudhary, James P. Flynn, Geoffrey Chen, Ashley M. Stuckwisch, Taryn Lipiner, Autumn Kittilson, Meghan Melberg, Rebecca F. Gilbert, Zahra Reynolds, Surabhi L. Iyer, Grace C. Chamberlin, Tammy D. Vyas, Jatin M. Vyas, Marcia B. Goldberg, Jeremy Luban, Jonathan Z. Li, Amy K. Barczak, Jacob E. Lemieux
×Abstract
Mass cytometry, or cytometry by TOF (CyTOF), provides a robust means of determining protein-level measurements of more than 40 markers simultaneously. While the functional states of immune cells occur along continuous phenotypic transitions, cytometric studies surveying cell phenotypes often rely on static metrics, such as discrete cell-type abundances, based on canonical markers and/or restrictive gating strategies. To overcome this limitation, we applied single-cell trajectory inference and nonnegative matrix factorization methods to CyTOF data to trace the dynamics of T cell states. In the setting of cancer immunotherapy, we showed that patient-specific summaries of continuous phenotypic shifts in T cells could be inferred from peripheral blood–derived CyTOF mass cytometry data. We further illustrated that transfer learning enabled these T cell continuous metrics to be used to estimate patient-specific cell states in new sample cohorts from a reference patient data set. Our work establishes the utility of continuous metrics for CyTOF analysis as tools for translational discovery.
Authors
Dimitrios N. Sidiropoulos, Genevieve L. Stein-O’Brien, Ludmila Danilova, Nicole E. Gross, Soren Charmsaz, Stephanie Xavier, James Leatherman, Hao Wang, Mark Yarchoan, Elizabeth M. Jaffee, Elana J. Fertig, Won Jin Ho
×Abstract
Background Apolipoprotein C-III (apoC-III) is a regulator of triglyceride (TG) metabolism, and due to its association with risk of cardiovascular disease, is an emergent target for pharmacological intervention. The impact of substantially lowering apoC-III on lipoprotein metabolism is not clear.Methods We investigated the kinetics of apolipoproteins B48 and B100 (apoB48 and apoB100) in chylomicrons, VLDL1, VLDL2, IDL, and LDL in patients heterozygous for a loss-of-function (LOF) mutation in the APOC3 gene. Studies were conducted in the postprandial state to provide a more comprehensive view of the influence of this protein on TG transport.Results Compared with non-LOF variant participants, a genetically determined decrease in apoC-III resulted in marked acceleration of lipolysis of TG-rich lipoproteins (TRLs), increased removal of VLDL remnants from the bloodstream, and substantial decrease in circulating levels of VLDL1, VLDL2, and IDL particles. Production rates for apoB48-containing chylomicrons and apoB100-containing VLDL1 and VLDL2 were not different between LOF carriers and noncarriers. Likewise, the rate of production of LDL was not affected by the lower apoC-III level, nor were the concentration and clearance rate of LDL-apoB100.Conclusion These findings indicate that apoC-III lowering will have a marked effect on TRL and remnant metabolism, with possibly significant consequences for cardiovascular disease prevention.Trial registration ClinicalTrials.gov NCT04209816 and NCT01445730.Funding Swedish Heart-Lung Foundation, Swedish Research Council, ALF grant from the Sahlgrenska University Hospital, Novo Nordisk Foundation, Sigrid Juselius Foundation, Helsinki University Hospital Government Research funds, Finnish Heart Foundation, and Finnish Diabetes Research Foundation.
Authors
Marja-Riitta Taskinen, Elias Björnson, Niina Matikainen, Sanni Söderlund, Joel Rämö, Mari-Mia Ainola, Antti Hakkarainen, Carina Sihlbom, Annika Thorsell, Linda Andersson, Per-Olof Bergh, Marcus Henricsson, Stefano Romeo, Martin Adiels, Samuli Ripatti, Markku Laakso, Chris J. Packard, Jan Borén
×Abstract
Obesity is an important risk factor for atrial fibrillation (AF), but a better mechanistic understanding of obesity-related atrial fibrillation is required. Serum glucocorticoid kinase 1 (SGK1) is a kinase positioned within multiple obesity-related pathways, and prior work has shown a pathologic role of SGK1 signaling in ventricular arrhythmias. We validated a mouse model of obesity-related AF using wild-type mice fed a high-fat diet. RNA sequencing of atrial tissue demonstrated substantial differences in gene expression, with enrichment of multiple SGK1-related pathways, and we showed upregulated of SGK1 transcription, activation, and signaling in obese atria. Mice expressing a cardiac specific dominant-negative SGK1 were protected from obesity-related AF, through effects on atrial electrophysiology, action potential characteristics, structural remodeling, inflammation, and sodium current. Overall, this study demonstrates the promise of targeting SGK1 in a mouse model of obesity-related AF.
Authors
Aneesh Bapat, Guoping Li, Ling Xiao, Ashish Yeri, Maarten Hulsmans, Jana Grune, Masahiro Yamazoe, Maximilian J. Schloss, Yoshiko Iwamoto, Justin Tedeschi, Xinyu Yang, Matthias Nahrendorf, Anthony Rosenzweig, Patrick T. Ellinor, Saumya Das, David Milan
×Abstract
Antithrombin, a major endogenous anticoagulant, is a serine protease inhibitor (serpin). We characterized the biological and clinical impact of variants involving C-terminal antithrombin. We performed comprehensive molecular, cellular, and clinical characterization of patients with C-terminal antithrombin variants from a cohort of 444 unrelated individuals with confirmed antithrombin deficiency. We identified 17 patients carrying 12 C-terminal variants, 5 of whom had the p.Arg445Serfs*17 deletion. Five missense variants caused qualitative deficiency, and 7, including 4 insertion-deletion variants, induced severe quantitative deficiency, particularly p.Arg445Serfs*17 (antithrombin <40%). This +1 frameshift variant had a molecular size similar to that of WT antithrombin but possessed a different C-terminus. Morphologic and cotransfection experiments showed that recombinant p.Arg445Serfs*17 was retained at the endoplasmic reticulum and had a dominant-negative effect on WT antithrombin. Characterization of different 1+ frameshift, aberrant C-terminal variants revealed that protein secretion was determined by frameshift site. The introduction of Pro441 in the aberrant C-terminus, shared by 5 efficiently secreted variants, partially rescued p.Arg445Serfs*17 secretion. C-terminal antithrombin mutants have notable heterogeneity, related to variant type and localization. Aberrant C-terminal variants caused by 1+ frameshift, with similar size as WT antithrombin, may be secreted or not, depending on frameshift site. The severe clinical phenotypes of these genetic changes are consistent with their dominant-negative effects.
Authors
Carlos Bravo-Pérez, Mara Toderici, Joseph E. Chambers, José A. Martínez-Menárguez, Pedro Garrido-Rodriguez, Horacio Pérez-Sanchez, Belén de la Morena-Barrio, José Padilla, Antonia Miñano, Rosa Cifuentes-Riquelme, Vicente Vicente, Maria L. Lozano, Stefan J. Marciniak, Maria Eugenia de la Morena-Barrio, Javier Corral
×Abstract
Histopathology, the standard method to assess BM in hematologic malignancies such as myeloproliferative neoplasms (MPNs), suffers from notable limitations in both research and clinical settings. BM biopsies in patients fail to detect disease heterogeneity, may yield a nondiagnostic sample, and cannot be repeated frequently in clinical oncology. Endpoint histopathology precludes monitoring disease progression and response to therapy in the same mouse over time, missing likely variations among mice. To overcome these shortcomings, we used MRI to measure changes in cellularity, macromolecular constituents, and fat versus hematopoietic cells in BM using diffusion-weighted imaging (DWI), magnetization transfer, and chemical shift–encoded fat imaging. Combining metrics from these imaging parameters revealed dynamic alterations in BM following myeloablative radiation and transplantation. In a mouse MPLW515L BM transplant model of MPN, MRI detected effects of a JAK2 inhibitor, ruxolitinib, within 5 days of initiating treatment and identified differing kinetics of treatment responses in subregions of the tibia. Histopathology validated the MRI results for BM composition and heterogeneity. Anatomic MRI scans also showed reductions in spleen volume during treatment. These findings establish an innovative, clinically translatable MRI approach to quantify spatial and temporal changes in BM in MPN.
Authors
Tanner H. Robison, Manisha Solipuram, Kevin Heist, Ghoncheh Amouzandeh, Winston Y. Lee, Brock A. Humphries, Johanna M. Buschhaus, Avinash Bevoor, Anne Zhang, Kathryn E. Luker, Kristen Pettit, Moshe Talpaz, Dariya Malyarenko, Thomas L. Chenevert, Brian D. Ross, Gary D. Luker
×Abstract
Individuals with β-thalassemia or sickle cell disease and hereditary persistence of fetal hemoglobin (HPFH) possessing 30% fetal hemoglobin (HbF) appear to be symptom free. Here, we used a nonintegrating HDAd5/35++ vector expressing a highly efficient and accurate version of an adenine base editor (ABE8e) to install, in vivo, a –113 A>G HPFH mutation in the γ-globin promoters in healthy CD46/β-YAC mice carrying the human β-globin locus. Our in vivo hematopoietic stem cell (HSC) editing/selection strategy involves only s.c. and i.v. injections and does not require myeloablation and HSC transplantation. In vivo HSC base editing in CD46/β-YAC mice resulted in > 60% –113 A>G conversion, with 30% γ-globin of β-globin expressed in 70% of erythrocytes. Importantly, no off-target editing at sites predicted by CIRCLE-Seq or in silico was detected. Furthermore, no critical alterations in the transcriptome of in vivo edited mice were found by RNA-Seq. In vitro, in HSCs from β-thalassemia and patients with sickle cell disease, transduction with the base editor vector mediated efficient –113 A>G conversion and reactivation of γ-globin expression with subsequent phenotypic correction of erythroid cells. Because our in vivo base editing strategy is safe and technically simple, it has the potential for clinical application in developing countries where hemoglobinopathies are prevalent.
Authors
Chang Li, Aphrodite Georgakopoulou, Gregory A. Newby, Kelcee A. Everette, Evangelos Nizamis, Kiriaki Paschoudi, Efthymia Vlachaki, Sucheol Gil, Anna K. Anderson, Theodore Koob, Lishan Huang, Hongjie Wang, Hans-Peter Kiem, David R. Liu, Evangelia Yannaki, André Lieber
×Abstract
The origin and mechanisms of autoantigen generation in systemic lupus erythematosus (SLE) are poorly understood. Here, we identified SLE neutrophils activated in vivo by IFN as a prominent source of Ro52, also known as tripartite motif–containing protein 21 (TRIM21), a critical autoantigen historically thought to be primarily generated by keratinocytes in SLE. Different from mononuclear cells and keratinocytes, SLE neutrophils are enriched in several unique Ro52 species containing a core sequence encoded by exon 4 (Ro52Ex4) in TRIM21. Ro52Ex4 is the main target of anti-Ro52 antibodies and is found in 2 Ro52 variants (Ro52α and an isoform termed Ro52γ) upregulated in SLE neutrophils. Further analysis of Ro52γ revealed a subset of autoantibodies against a unique C-terminal domain (Ro52γCT) generated from a frameshift due to the lack of exon 6 in Ro52γ. Antibodies to Ro52Ex4 and Ro52γCT distinguish SLE patient subsets characterized by distinct clinical, laboratory, treatment, and transcriptional profiles that are not discerned by the “classical” anti-Ro52 antibodies. These studies uncover IFN-activated neutrophils as a key source of unique immunogenic forms of Ro52 in SLE. Moreover, the finding of Ro52Ex4 and Ro52γCT as core targets of anti-Ro52 antibodies focus interest on Ro52γ as the potential isoform toward which immunological tolerance is initially lost in SLE.
Authors
Eduardo Gomez-Bañuelos, M. Javad Wahadat, Jessica Li, Merlin Paz, Brendan Antiochos, Alessandra Ida Celia, Victoria Andrade, Dylan P. Ferris, Daniel W. Goldman, Erika Darrah, Michelle Petri, Felipe Andrade
