Quadruple mutation GCAC1809-1812TTCT acts as a biomarker in healthy European HBV carriers

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Abstract

In search of new prognostic markers, many mutation analyses of the HBV genome were performed. However, the Kozak sequence preceding precore was covered only infrequently in these analyses. In this study, HBV core promoter/precore region was sequenced in serum samples of European inactive HBV carriers (n=560). Quadruple mutation GCAC1809-1812TTCT was found with a high prevalence of 42% in the Kozak sequence preceding precore among all HBV genotypes. GCAC1809-1812TTCT was strongly associated with coexistence of basal core promoter (BCP) double mutation A1762T/G1764A and lower HBV DNA levels (p<0.0001). In vitro GCAC1809-1812TTCT leads to drastically diminished synthesis of pregenomic(pg)RNA, precore mRNA, core, HBsAg and HBeAg. Calculation of the pgRNA secondary structure suggests a destabilization of the pgRNA structure by A1762T/G1764A that is compensated by GCAC1809-1812TTCT. In 125 patients with HBV-related cirrhosis, GCAC1809-1812TTCT was not detected. While a strong association of GCAC1809-1812TTCT with inactive carrier status (p<0.0001) was observed, BCP double mutation was strongly correlated with cirrhosis (p<0.0001), but this was only observed in absence of GCAC1809-1812TTCT. In conclusion, our data reveal that GCAC1809-1812TTCT is highly prevalent in inactive carriers, and acts as a compensatory mutation for BCP double mutation. GCAC1809-1812TTCT seems to be a biomarker of good prognosis in HBV infection.

Authors

Kai-Henrik Peiffer, Catrina Spengler, Michael Basic, Bingfu Jiang, Lisa Kuhnhenn, Wiebke Obermann, Tobias Zahn, Mirco Glitscher, Alessandro Loglio, Floriana Facchetti, Gert Carra, Alica Kubesch, Johannes Vermehren, Viola Knop, Christiana Graf, Julia Dietz, Fabian Finkelmeier, Eva Herrmann, Jonel Trebicka, Arnold Grünweller, Stefan Zeuzem, Christoph Sarrazin, Pietro Lampertico, Eberhard Hildt

C-type natriuretic peptide moderates titin-based cardiomyocyte stiffness

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Abstract

Heart failure is often accompanied by titin-dependent myocardial stiffness. Phosphorylation of titin by cGMP-dependent protein kinase (PKG)I increases cardiomyocyte distensibility. The upstream pathways stimulating PKGI-mediated titin phosphorylation are unclear. We studied whether C-type natriuretic peptide (CNP), via its guanylyl cyclase-B (GC-B) receptor and cGMP/PKGI signalling, modulates titin-based ventricular compliance. To dissect GC-B-mediated effects of endogenous CNP in cardiomyocytes, we generated mice with cardiomyocyte (CM)-restricted GC-B deletion. The impact on heart morphology and function, myocyte passive tension and titin isoform expression and phosphorylation was studied at baseline and after increased afterload induced by transverse aortic constriction (TAC).Pressure-overload increased left ventricular, especially endothelial CNP expression, with an early peak after 3 days. Concomitantly, titin phosphorylation at Ser4080, the site phosphorylated by PKGI, was augmented. Notably, in CM GC-B KO mice this titin response was abolished. TAC-induced hypertrophy and fibrosis were not different between genotypes. However, the KO mice presented mild systolic and diastolic dysfunction together with myocyte stiffness, which were not observed in control littermates. In vitro, recombinant PKGI rescued reduced Titin-Ser4080 phosphorylation and reverted passive stiffness of GC-B-deficient cardiomyocytes. CNP-induced activation of GC-B/cGMP/PKGI signalling in cardiomyocytes provides a protecting regulatory circuit preventing titin-based myocyte stiffening during early phases of pressure-overload.

Authors

Konstanze Michel, Melissa Herwig, Franziska Werner, Katarina Špiranec Spes, Marco Abeßer, Kai Schuh, Swati Dabral, Andreas Mügge, Hideo A. Baba, Boris V. Skryabin, Nazha Hamdani, Michaela Kuhn

Tumor genotype, location and malignant potential shape the immunogenicity of primary, untreated Gastrointestinal Stromal Tumors

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Abstract

Intratumoral immune infiltrate was recently reported in Gastrointestinal Stromal Tumors (GIST). However, what tumor-intrinsic factors dictate GIST immunogenicity is still largely undefined. To shed light on this issue a large cohort (82 samples) of primary untreated GIST, representative of major clinicopathological variables, was investigated by an integrated immunohistochemical, transcriptomic and computational approach. Our results indicate that tumor genotype, location and malignant potential concur to shape the immunogenicity of primary naïve GIST. Immune infiltration was greater in overt GIST than in lesions with limited malignant potential (miniGIST), in KIT/PDGFRA mutated than in KIT/PDGFRA wild-type tumors and in PDGFRA versus KIT mutated GIST. Within the KIT mutated subset, a higher degree of immune colonization was detected in the intestine. Immune hot tumors showed expression patterns compatible with a potentially proficient but curbed antigen-specific immunity, hinting at sensitivity to immunomodulatory treatments. Poorly infiltrated GIST, primarily KIT/PDGFRA wild-type intestinal tumors, showed activation of Hedgehog and WNT/β-catenin immune excluding pathways. This finding discloses a potential therapeutic vulnerability, as the targeting of these pathways might prove effective by both inhibiting pro-oncogenic signals and fostering anti-tumor immune responses. Finally, an intriguing anticorrelation between immune infiltration and ANO1/DOG1 expression was observed, suggesting an immunomodulatory activity for anoctamin-1.

Authors

Daniela Gasparotto, Marta Sbaraglia, Sabrina Rossi, Davide Baldazzi, Monica Brenca, Alessia Mondello, Federica Nardi, Dominga Racanelli, Matilde Cacciatore, Angelo Paolo Dei Tos, Roberta Maestro

WNK1 regulates uterine homeostasis and its ability to support pregnancy

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Abstract

WNK1 is an atypical kinase protein ubiquitously expressed in humans and mice. A mutation in its encoding gene causes hypertension in humans which is associated with abnormal ion homeostasis. WNK1 is critical for in vitro decidualization in human endometrial stromal cells, thereby demonstrating its importance in female reproduction. Using a mouse model, WNK1 was ablated in the female reproductive tract to define its in vivo role in uterine biology. Loss of WNK1 altered uterine morphology, causing endometrial epithelial hyperplasia, adenomyotic features and a delay in embryo implantation, ultimately resulting in compromised fertility. Combining transcriptomic, proteomic and interactomic analyses revealed a novel regulatory pathway whereby WNK1 represses AKT phosphorylation through the phosphatase PP2A in endometrial cells from both humans and mice. We show that WNK1 interacts with PPP2R1A, the alpha isoform of the PP2A scaffold subunit. This maintains the levels of PP2A subunits and stabilizes its activity, which then dephosphorylates AKT. Therefore, loss of WNK1 reduced PP2A activity, causing AKT hypersignaling. Using FOXO1 as a readout of AKT activity, we demonstrate that there was escalated FOXO1 phosphorylation and nuclear exclusion, leading to a disruption in the expression of genes that are crucial for embryo implantation.

Authors

Ru-pin Alicia Chi, Tianyuan Wang, Chou-Long Huang, San-Pin Wu, Steven Young, John Lydon, Francesco DeMayo

IgG3 collaborates with IgG1 and IgA to recruit effector function in RV144 vaccinees

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Abstract

While the RV144 HIV vaccine trial lead to moderately reduced risk of HIV acquisition, emerging data from the repeat failure of the HVTN702 trial point to the critical need to re-examine the relationships between previously identified correlates of reduced risk of protection in the RV144 study. Specifically, the induction of V2-binding, non-IgA, IgG3 antibody responses with non-neutralizing functions were linked to reduced risk of infection in RV144 vaccinees. While each of these features was individually linked to reduced risk of infection, the relationships and interactions between these humoral immune signatures remain unclear. Thus, here we comprehensively profiled the humoral immune response in 300 RV144 vaccinees to specifically decipher the relationships between humoral biomarkers of protection and susceptibility. Here, we found that vaccine-specific IgG1, IgG3, and IgA were highly correlated. However, ratios of IgG1:IgG3:IgA provided new insights into subclass/isotype polyclonal functional regulation. For instance, in the absence of high IgG1 levels, IgG3 antibodies exhibited limited functional activity, pointing to IgG3 as a critical contributor, but not sole driver, of more effective antiviral humoral immunity. Moreover, in contrast to previous findings, higher IgA levels were linked to enhanced antibody effector function, including neutrophil phagocytosis (ADNP), complement deposition (ADCD) and NK degranulation (CD107a). Several IgA-associated functions were increased in infected vaccinees in a case:control dataset, suggesting that rather than blocking, IgA may have driven deleterious functions, thereby compromising immunity. These data highlight the interplay between IgG1, IgG3 and IgA, pointing to the critical need to deeply profile the relationships between subclass/isotype selection.

Authors

Stephanie Fischinger, Sepideh Dolatshahi, Madeleine F. Jennewein, Supachai Rerks-Ngarm, Punnee Pitisuttithum, Sorachai Nitayaphan, Nelson L. Michael, Sandhya Vasan, Margaret E Ackerman, Hendrik Streeck, Galit Alter

LncRNA VINAS regulates atherosclerosis by modulating NF-κB and MAPK signaling

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Abstract

Long non-coding RNAs (lncRNAs) play important roles in regulating diverse cellular processes in the vessel wall, including atherosclerosis. RNAseq profiling of intimal lesions revealed a lncRNA, VINAS (Vascular INfllammation and Atherosclerosis lncRNA Sequence), that is enriched in the aortic intima and regulates vascular inflammation. Aortic intimal expression of VINAS fell with atherosclerotic progression and rose with regression. VINAS knockdown reduced atherosclerotic lesion formation by 55% in LDLR-/- mice, independent of effects on circulating lipids, by decreasing inflammation in the vessel wall. Loss- and gain-of-function studies in vitro demonstrated that VINAS serves as a critical regulator of inflammation by modulating NF-κB and MAPK signaling pathways. VINAS knockdown decreased the expression of key inflammatory markers, such as MCP-1, TNF-α, IL-1β , COX-2, in endothelial (EC), vascular smooth muscle cells, and bone marrow-derived macrophages. Moreover, VINAS silencing decreased expression of leukocyte adhesion molecules VCAM-1, E-selectin, and ICAM-1 and reduced monocyte adhesion to ECs. DEPDC4, an evolutionary conserved human ortholog of VINAS with ~74% homology, shows similar regulation in human and pig atherosclerotic specimens. DEPDC4 knockdown replicated VINAS’ anti-inflammatory effects in human ECs. These findings reveal a novel lncRNA that regulates vascular inflammation, with broad implications for vascular diseases.

Authors

Viorel Simion, Haoyang Zhou, Jacob B. Pierce, Dafeng Yang, Stefan Haemmig, Yevgenia Tesmenitsky, Galina Sukhova, Peter H. Stone, Peter Libby, Mark W. Feinberg

Monoclonal full-length antibody against TAR DNA-binding protein 43 reduces related proteinopathy in neurons

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Abstract

Amyotrophic Lateral Sclerosis (ALS) and FrontoTemporal Lobar Degeneration (FTLD), two incurable neurodegenerative disorders, share the same pathological hallmark named TDP43 (TAR DNA binding protein 43) proteinopathy. This event is characterized by a consistent cytoplasmic mislocalization and aggregation of the protein TDP43 which loses its physiological properties leading neurons to death. Antibody-based approaches are now emerging interventions in the field of neurodegenerative disorders. Here we tested the target specificity, in vivo distribution and therapeutic efficacy of a monoclonal full-length antibody, named E6, in TDP43 related conditions. We observed that the antibody recognizes specifically the cytoplasmic fraction of TDP43. We demonstrated its ability in targeting large neurons in the spinal cord of mice and in reducing TDP43 mislocalization and NF-B activation. We also recognized the proteasome as well as the lysosome machineries as possible mechanisms used by the antibody to reduce TDP43 proteinopathy. To our knowledge this is the first report showing the therapeutic efficacy and feasibility of a full-length antibody against TDP43 in reducing TDP43 proteinopathy in spinal neurons of an ALS/FTLD mouse model.

Authors

Silvia Pozzi, Philippe Codron, Genevieve Soucy, Laurence Renaud, Pierre Cordeau, Kallol Dutta, Christine Bareil, Jean-Pierre Julien

Alveolar barrier disruption in varicella pneumonia is associated with neutrophil extracellular trap formation

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Abstract

Primary varicella-zoster virus (VZV) infection in adults is often complicated by severe pneumonia, which is difficult to treat and associated with high morbidity and mortality. Here, the simian varicella virus (SVV) nonhuman primate (NHP) model was used to investigate the pathogenesis of varicella pneumonia. SVV infection resulted in transient fever, viremia and robust virus replication in alveolar pneumocytes and bronchus-associated lymphoid tissue. Clearance of infectious virus from lungs coincided with robust innate immune responses, leading to recruitment of inflammatory cells, mainly neutrophils and lymphocytes, and finally severe acute lung injury. SVV infection caused neutrophil activation and formation of neutrophil extracellular traps (NETs) in vitro and in vivo. Notably, NETs were also detected in lung and blood specimens of varicella pneumonia patients. Lung pathology in the SVV NHP model was associated with dysregulated expression of alveolar epithelial cell tight junction proteins (claudin-2, claudin-10 and claudin-18) and alveolar endothelial adherens junction protein VE-cadherin. Importantly, factors released by activated neutrophils, including NETs, were sufficient to reduce claudin-18 and VE-cadherin expression in NHP lung slice cultures. Collectively, the data indicate that local inflammatory responses involving activated neutrophils contribute to impaired alveolar epithelial/endothelial barrier integrity in varicella pneumonia and possibly other virus-induced acute lung injuries.

Authors

Werner J.D. Ouwendijk, Henk Jan van den Ham, Mark W. Delany, Jeroen J.A. van Kampen, Gijsbert P. van Nierop, Tamana Mehraban, Fatiha Zaaraoui-Boutahar, Wilfred F.J. van IJcken, Judith M.A. van den Brand, Rory D. De Vries, Arno C. Andeweg, Georges M.G.M. Verjans

In utero human intestine harbors unique metabolomic features including bacterial metabolites

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Abstract

Symbiotic microbial colonization through the establishment of the intestinal microbiome is critical to many intestinal functions including nutrient metabolism, intestinal barrier integrity and immune regulation. Recent studies suggest that education of the intestinal immunity maybe ongoing in utero. However, the drivers of this process are unknown. The microbiome and its byproducts are one potential source. Whether a fetal intestinal microbiome exists is controversial and if microbially derived metabolites are present in utero is unknown. Here, we aimed to determine whether bacterial DNA and microbially-derived metabolites can be detected in second trimester human intestinal samples. Although, we were unable to amplify bacterial DNA from fetal intestines, we report a unique fetal metabolomic intestinal profile with an abundance of bacterially derived and host derived metabolites commonly produced in response to microbiota. Though we did not directly assess their source and function, we hypothesize that these microbial associated metabolites come either from the maternal microbiome and are vertically transmitted to the fetus to prime the fetal immune system and prepare the gastrointestinal tract for postnatal microbial encounters or are produced locally by bacteria that was below our detection threshold.

Authors

Yujia Li, Jessica M. Toothaker, Shira Ben-Simon, Lital Ozeri, Ron Schweitzer, Blake T. McCourt, Collin C. McCourt, Lael Werner, Scott B. Snapper, Dror S. Shouval, Soliman Khatib, Omry Koren, Sameer Agnihorti, George Tseng, Liza Konnikova

Pathogenic and therapeutic role for NRF2-signaling in ultraviolet light-induced skin pigmentation

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Abstract

Mottled skin pigmentation and solar lentigines from chronic photodamage with aging involves complex interactions between keratinocytes and melanocytes. However, the precise signaling mechanisms that could serve as therapeutic targets are unclear. Herein, we report that expression of nuclear factor erythroid 2-related factor 2 (NRF2), which regulates reduction–oxidation reactions, is altered in solar lentigines and photodamaged skin. Moreover, mottled skin pigmentation in humans could be treated with topical application of the NRF2 inducer sulforaphane (SF). Similarly, ultraviolet (UV) light-induced pigmentation of wildtype mouse ear skin could be treated or prevented with SF treatment. Conversely, SF treatment was unable to reduce UV-induced ear skin pigmentation in mice deficient in NRF2 or in mice with keratinocyte-specific conditional deletion of IL-6Rα. Taken together, NRF2 and IL-6Rα signaling are involved in the pathogenesis of UV-induced skin pigmentation and specific enhancement of NRF2-signaling could represent a potential therapeutic target.

Authors

Michelle L. Kerns, Robert J. Miller, Momina Mazhar, Angel S. Byrd, Nathan K. Archer, Bret L. Pinsker, Lance S. Lew, Carly A. Dillen, Ruizhi Wang, Lloyd S. Miller, Anna L. Chien, Sewon Kang