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Abstract

Overexpression of myo-inositol oxygenase (MIOX), a proximal tubular enzyme, exacerbates cellular redox injury in acute kidney injury (AKI). Ferroptosis, a newly coined term associated with lipid hydroperoxidation, plays a critical role in the pathogenesis of AKI. Whether or not MIOX exacerbates tubular damage by accelerating ferroptosis in cisplatin-induced AKI remains elusive. Cisplatin-treated HK-2 cells exhibited notable cell death, which was reduced by ferroptosis inhibitors. Also, alterations in various ferroptosis metabolic sensors, including lipid hydroperoxidation, glutathione peroxidase 4 (GPX4) activity, NADPH and reduced glutathione (GSH) levels, and ferritinophagy, were observed. These perturbations were accentuated by MIOX overexpression, while ameliorated by MIOX knockdown. Likewise, cisplatin-treated CD1 mice exhibited tubular damage and derangement of renal physiological parameters, which were alleviated by ferrostatin-1, a ferroptosis inhibitor. To investigate the relevance of MIOX to ferroptosis, WT mice, MIOX-overexpressing transgenic (MIOX-Tg) mice, and MIOX-KO mice were subjected to cisplatin treatment. In comparison with cisplatin-treated WT mice, cisplatin-treated MIOX-Tg mice had more severe renal pathological changes and perturbations in ferroptosis metabolic sensors, which were minimal in cisplatin-treated MIOX-KO mice. In conclusion, these findings indicate that ferroptosis, an integral process in the pathogenesis of cisplatin-induced AKI, is modulated by the expression profile of MIOX.

Authors

Fei Deng, Isha Sharma, Yingbo Dai, Ming Yang, Yashpal S. Kanwar

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Abstract

We hypothesized that the store-operated calcium entry (SOCE) channel, Orai1, participates in the activation of Th17 cells and influences renal injury. In rats, following renal ischemia/reperfusion (I/R), there was a rapid and sustained influx of Orai1+ CD4 T cells and IL-17 expression was restricted to Orai1+ cells. When kidney CD4+ cells of post–acute kidney injury (post-AKI) rats were stimulated with angiotensin II and elevated Na+ (10–7 M/170 mM) in vitro, there was an enhanced response in intracellular Ca2+ and IL-17 expression, which was blocked by SOCE inhibitors 2APB, YM58483/BTP2, or AnCoA4. In vivo, YM58483/BTP2 (1 mg/kg) attenuated IL-17+ cell activation, inflammation, and severity of AKI following either I/R or intramuscular glycerol injection. Rats treated with high-salt diet (5–9 weeks after I/R) manifested progressive disease indicated by enhanced inflammation, fibrosis, and impaired renal function. These responses were significantly attenuated by YM58483/BTP2. In peripheral blood of critically ill patients, Orai1+ cells were significantly elevated by approximately 10-fold and Th17 cells were elevated by approximately 4-fold in AKI versus non-AKI patients. Further, in vitro stimulation of CD4+ cells from AKI patients increased IL-17, which was blocked by SOCE inhibitors. These data suggest that Orai1 SOCE is a potential therapeutic target in AKI and CKD progression.

Authors

Purvi Mehrotra, Michael Sturek, Javier A. Neyra, David P. Basile

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Abstract

The interleukin-3 receptor α subunit, CD123, is expressed in many hematologic malignancies including acute myeloid leukemia (AML) and blastic plasmacytoid dendritic cell neoplasm (BPDCN). Tagraxofusp (SL-401) is a CD123-targeted therapy consisting of interleukin-3 fused to a truncated diphtheria toxin payload. Factors influencing response to tagraxofusp other than CD123 expression are largely unknown. We interrogated tagraxofusp resistance in patients and experimental models and found that it was not associated with CD123 loss. Rather, resistant AML and BPDCN cells frequently acquired deficiencies in the diphthamide synthesis pathway, impairing tagraxofusp’s ability to ADP-ribosylate cellular targets. Expression of DPH1, encoding a diphthamide pathway enzyme, was reduced by DNA CpG methylation in resistant cells. Treatment with the DNA methyltransferase inhibitor azacitidine restored DPH1 expression and tagraxofusp sensitivity. We also developed a drug-dependent ADP-ribosylation assay in primary cells that correlated with tagraxofusp activity and may represent an additional novel biomarker. As predicted by these results and our observation that resistance also increased mitochondrial apoptotic priming, we found that the combination of tagraxofusp and azacitidine was effective in patient-derived xenografts treated in vivo. These data have important implications for clinical use of tagraxofusp and led to a phase 1 study combining tagraxofusp and azacitidine in myeloid malignancies.

Authors

Katsuhiro Togami, Timothy Pastika, Jason Stephansky, Mahmoud Ghandi, Amanda L. Christie, Kristen L. Jones, Carl A. Johnson, Ross W. Lindsay, Christopher L. Brooks, Anthony Letai, Jeffrey W. Craig, Olga Pozdnyakova, David M. Weinstock, Joan Montero, Jon C. Aster, Cory M. Johannessen, Andrew A. Lane

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Abstract

T cell autoreactivity is a hallmark of autoimmune diseases but can also benefit self-maintenance and foster tissue repair. Here, we investigated whether heart-specific T cells exert salutary or detrimental effects in the context of myocardial infarction (MI), the leading cause of death worldwide. After screening more than 150 class II–restricted epitopes, we found that myosin heavy chain α (MYHCA) was a dominant cardiac antigen triggering post-MI CD4+ T cell activation in Balb/c mice. Transferred MYHCA614–629-specific CD4+ T cells (TCR-M cells) selectively accumulated in the myocardium and mediastinal lymph nodes (med-LNs) of infarcted mice, acquired a Treg phenotype with a distinct prohealing gene expression profile, and mediated cardioprotection. Myocardial Tregs were also detected in autopsy samples from patients who had had a MI. Noninvasive PET/CT imaging using a CXCR4 radioligand revealed enlarged med-LNs with increased cellularity in patients with MI. Notably, the med-LN alterations observed in MI patients correlated with the infarct size and cardiac function. Taken together, the results obtained in our study provide evidence that MI context induces prohealing T cell autoimmunity in mice and confirm the existence of an analogous heart/med-LN/T cell axis in patients with MI.

Authors

Max Rieckmann, Murilo Delgobo, Chiara Gaal, Lotte Büchner, Philipp Steinau, Dan Reshef, Cristina Gil-Cruz, Ellis N. ter Horst, Malte Kircher, Theresa Reiter, Katrin G. Heinze, Hans W.M. Niessen, Paul A.J. Krijnen, Anja M. van der Laan, Jan J. Piek, Charlotte Koch, Hans-Jürgen Wester, Constantin Lapa, Wolfgang R. Bauer, Burkhard Ludewig, Nir Friedman, Stefan Frantz, Ulrich Hofmann, Gustavo Campos Ramos

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Abstract

BACKGROUND Impaired T cell immunity in transplant recipients is associated with infection-related morbidity and mortality. We recently reported the successful use of adoptive T cell therapy (ACT) against drug-resistant/recurrent cytomegalovirus in solid-organ transplant recipients.METHODS In the present study, we used high-throughput T cell receptor Vβ sequencing and T cell functional profiling to delineate the impact of ACT on T cell repertoire remodeling in the context of pretherapy immunity and ACT products.RESULTS These analyses indicated that a clinical response was coincident with significant changes in the T cell receptor Vβ landscape after therapy. This restructuring was associated with the emergence of effector memory T cells in responding patients, while nonresponders displayed dramatic pretherapy T cell expansions with minimal change following ACT. Furthermore, immune reconstitution included both adoptively transferred clonotypes and endogenous clonotypes not detected in the ACT products.CONCLUSION These observations demonstrate that immune control following ACT requires significant repertoire remodeling, which may be impaired in nonresponders because of the preexisting immune environment. Immunological interventions that can modulate this environment may improve clinical outcomes.TRIAL REGISTRATION Australian New Zealand Clinical Trial Registry, ACTRN12613000981729.FUNDING This study was supported by funding from the National Health and Medical Research Council, Australia (APP1132519 and APP1062074).

Authors

Corey Smith, Dillon Corvino, Leone Beagley, Sweera Rehan, Michelle A. Neller, Pauline Crooks, Katherine K. Matthews, Matthew Solomon, Laetitia Le Texier, Scott Campbell, Ross S. Francis, Daniel Chambers, Rajiv Khanna

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Abstract

Asthma is a heterogeneous syndrome that has been subdivided into physiologic phenotypes and molecular endotypes. The most specific phenotypic manifestation of asthma is indirect airway hyperresponsiveness (AHR), and a prominent molecular endotype is the presence of type 2 inflammation. The underlying basis for type 2 inflammation and its relationship to AHR are incompletely understood. We assessed the expression of type 2 cytokines in the airways of subjects with and without asthma who were extensively characterized for AHR. Using quantitative morphometry of the airway wall, we identified a shift in mast cells from the submucosa to the airway epithelium specifically associated with both type 2 inflammation and indirect AHR. Using ex vivo modeling of primary airway epithelial cells in organotypic coculture with mast cells, we show that epithelial-derived IL-33 uniquely induced type 2 cytokines in mast cells, which regulated the expression of epithelial IL33 in a feed-forward loop. This feed-forward loop was accentuated in epithelial cells derived from subjects with asthma. These results demonstrate that type 2 inflammation and indirect AHR in asthma are related to a shift in mast cell infiltration to the airway epithelium, and that mast cells cooperate with epithelial cells through IL-33 signaling to regulate type 2 inflammation.

Authors

Matthew C. Altman, Ying Lai, James D. Nolin, Sydney Long, Chien-Chang Chen, Adrian M. Piliponsky, William A. Altemeier, Megan Larmore, Charles W. Frevert, Michael S. Mulligan, Steven F. Ziegler, Jason S. Debley, Michael C. Peters, Teal S. Hallstrand

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Abstract

Molecular heterogeneity of endothelial cells underlies their highly specialized functions during changing physiological conditions within diverse vascular beds. For example, placental spiral arteries (SAs) undergo remarkable remodeling to meet the ever-growing demands of the fetus — a process which is deficient in preeclampsia. The extent to which maternal endothelial cells coordinate with immune cells and pregnancy hormones to promote SA remodeling remains largely unknown. Here we found that remodeled SAs expressed the lymphatic markers PROX1, LYVE1, and VEGFR3, mimicking lymphatic identity. Uterine natural killer (uNK) cells, which are required for SA remodeling and secrete VEGFC, were both sufficient and necessary for VEGFR3 activation in vitro and in mice lacking uNK cells, respectively. Using Flt4Chy/+ mice with kinase inactive VEGFR3 and Vegfcfl/fl Vav1-Cre mice, we demonstrated that SA remodeling required VEGFR3 signaling, and that disrupted maternal VEGFR3 signaling contributed to late-gestation fetal growth restriction. Collectively, we identified a novel instance of lymphatic mimicry by which maternal endothelial cells promote SA remodeling, furthering our understanding of the vascular heterogeneity employed for the mitigation of pregnancy complications such as fetal growth restriction and preeclampsia.

Authors

John B. Pawlak, László Bálint, Lillian Lim, Wanshu Ma, Reema B. Davis, Zoltán Benyó, Michael J. Soares, Guillermo Oliver, Mark L. Kahn, Zoltán Jakus, Kathleen M. Caron

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Abstract

Macrophages are important in mounting an innate immune response to injury as well as in repair of injury. Gene expression of Rho proteins is known to be increased in fibrotic models; however, the role of these proteins in idiopathic pulmonary fibrosis (IPF) is not known. Here, we show that BAL cells from patients with IPF have a profibrotic phenotype secondary to increased activation of the small GTPase Rac1. Rac1 activation requires a posttranslational modification, geranylgeranylation, of the C-terminal cysteine residue. We found that by supplying more substrate for geranylgeranylation, Rac1 activation was substantially increased, resulting in profibrotic polarization by increasing flux through the mevalonate pathway. The increased flux was secondary to greater levels of acetyl-CoA from metabolic reprogramming to β oxidation. The polarization mediated fibrotic repair in the absence of injury by enhancing macrophage/fibroblast signaling. These observations suggest that targeting the mevalonate pathway may abrogate the role of macrophages in dysregulated fibrotic repair.

Authors

Jennifer L. Larson-Casey, Mudit Vaid, Linlin Gu, Chao He, Guo-Qiang Cai, Qiang Ding, Dana Davis, Taylor F. Berryhill, Landon S. Wilson, Stephen Barnes, Jeffrey D. Neighbors, Raymond J. Hohl, Kurt A. Zimmerman, Bradley K. Yoder, Ana Leda F. Longhini, Vidya Sagar Hanumanthu, Ranu Surolia, Veena B. Antony, A. Brent Carter

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Abstract

Atrial fibrillation (AF), defined by disorganized atrial cardiac rhythm, is the most prevalent cardiac arrhythmia worldwide. Recent genetic studies have highlighted a major heritable component and identified numerous loci associated with AF risk, including the cardiogenic transcription factor genes TBX5, GATA4, and NKX2-5. We report that Tbx5 and Gata4 interact with opposite signs for atrial rhythm controls compared with cardiac development. Using mouse genetics, we found that AF pathophysiology caused by Tbx5 haploinsufficiency, including atrial arrhythmia susceptibility, prolonged action potential duration, and ectopic cardiomyocyte depolarizations, were all rescued by Gata4 haploinsufficiency. In contrast, Nkx2-5 haploinsufficiency showed no combinatorial effect. The molecular basis of the TBX5/GATA4 interaction included normalization of intra-cardiomyocyte calcium flux and expression of calcium channel genes Atp2a2 and Ryr2. Furthermore, GATA4 and TBX5 showed antagonistic interactions on an Ryr2 enhancer. Atrial rhythm instability caused by Tbx5 haploinsufficiency was rescued by a decreased dose of phospholamban, a sarco/endoplasmic reticulum Ca2+-ATPase inhibitor, consistent with a role for decreased sarcoplasmic reticulum calcium flux in Tbx5-dependent AF susceptibility. This work defines a link between Tbx5 dose, sarcoplasmic reticulum calcium flux, and AF propensity. The unexpected interactions between Tbx5 and Gata4 in atrial rhythm control suggest that evaluating specific interactions between genetic risk loci will be necessary for ascertaining personalized risk from genetic association data.

Authors

Brigitte Laforest, Wenli Dai, Leonid Tyan, Sonja Lazarevic, Kaitlyn M. Shen, Margaret Gadek, Michael T. Broman, Christopher R. Weber, Ivan P. Moskowitz

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Abstract

The interleukin 3 receptor (CD123) is a transmembrane protein that is absent or hardly expressed on normal hematopoietic stem cells, but highly expressed on the surface of cancer cells in several hematologic malignancies. In this issue of the JCI, Togami et al. investigated the mechanism of resistance to the recently approved anti-CD123 agent tagraxofusp, which consists of interleukin 3 fused to a truncated diphtheria toxin (DT) molecule. The authors demonstrated that loss of the intracellular target for DT, diphthamide, a conservative modification of histidine 715 in eukaryotic elongation factor 2, resulted in tagraxofusp resistance. Specifically, hypermethylation of the DPH1 gene, encoding a key enzyme in diphthamide synthesis, resulted in diphthamide loss. Notably, treatment with a DNA hypomethylating agent restored DPH1 expression and resensitized cells to tagraxofusp. The recognition of this resistance mechanism may have important clinical implications and lead to the development of more effective multiagent therapies.

Authors

Lukasz P. Gondek

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Abstract

A strong Th17 inflammatory response aggravates ischemia reperfusion–induced (IR-induced) acute kidney injury (AKI), tissue fibrosis, and AKI-to–chronic kidney disease (CKD) progression. However, the underlying mechanisms of sustained Th17 activation following AKI and during AKI-to-CKD progression are unclear. In this issue of the JCI, Mehrotra et al. present compelling evidence that the store-operated calcium (Ca2+) channel Orai1 sustains Th17-driven inflammatory response after AKI and drives the AKI-to-CKD transition. Orai1 blockade significantly protected renal function from IR, attenuated high-salt–induced AKI-to-CKD progression in rats, and decreased Th17 response in rat and human T cells. Therapeutic targeting of Orai1 can potentially reduce AKI, AKI-to-CKD progression, and other Th17-driven diseases.

Authors

Sanjeev Noel

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Abstract

Cardiac tissue necrosis secondary to coronary artery occlusion is one of the most common and deadly sterile injuries in developed countries. In this issue of the JCI, Rieckmann et al. identified and characterized antigen-specific CD4+ T helper (Th) cells that developed in the context of myocardial infarction (MI) in mice. They showed that myosin heavy chain α (MYHCA) is a dominant cardiac autoantigen and that T cells with T cell receptor (TCR) specificity to MYHCA acquired a Treg phenotype when adoptively transferred into infarcted mice, which mediated a cardioprotective healing response. Thus, Rieckmann et al. showed that an acute ischemic insult to the heart, which induces sterile inflammation, promoted, rather than limited, protective T cell autoimmunity. Notably, strategies that support an antigen-specific Treg response may limit the immune-inflammatory response and promote cardiac repair after acute MI.

Authors

Ziad Mallat

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Abstract

Tumor-resident lymphocytes can mount a response against neoantigens expressed in microsatellite-stable gastrointestinal (GI) cancers, and adoptive transfer of neoantigen-specific lymphocytes has demonstrated antitumor activity in selected patients. However, whether peripheral blood could be used as an alternative minimally invasive source to identify lymphocytes targeting neoantigens in patients with GI cancer with relatively low mutation burden is unclear. We used a personalized high-throughput screening strategy to investigate whether PD-1 expression in peripheral blood could be used to identify CD8+ or CD4+ lymphocytes recognizing neoantigens identified by whole-exome sequencing in 7 patients with GI cancer. We found that neoantigen-specific lymphocytes were preferentially enriched in the CD8+PD-1+/hi or CD4+PD-1+/hi subsets, but not in the corresponding bulk or PD-1– fractions. In 6 of 7 individuals analyzed we identified circulating CD8+ and CD4+ lymphocytes targeting 6 and 4 neoantigens, respectively. Moreover, neoantigen-reactive T cells and a T cell receptor (TCR) isolated from the CD8+PD-1+ subsets recognized autologous tumor, albeit at reduced levels, in 2 patients with available cell lines. These data demonstrate the existence of circulating T cells targeting neoantigens in GI cancer patients and provide an approach to generate enriched populations of personalized neoantigen-specific lymphocytes and isolate TCRs that could be exploited therapeutically to treat cancer.

Authors

Alena Gros, Eric Tran, Maria R. Parkhurst, Sadia Ilyas, Anna Pasetto, Eric M. Groh, Paul F. Robbins, Rami Yossef, Andrea Garcia-Garijo, Carlos A. Fajardo, Todd D. Prickett, Li Jia, Jared J. Gartner, Satyajit Ray, Lien Ngo, John R. Wunderllich, James C. Yang, Steven A. Rosenberg

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Abstract

The Toll-like receptor 8 (TLR8) has an important role in innate immune responses to RNA viral infections, including respiratory syncytial virus (RSV). We previously reported that TLR8 expression was increased directly by the tumor suppressor and transcription factor p53 via a single nucleotide polymorphism (SNP) (rs3761624) in the TLR8 promoter, thereby placing TLR8 in the p53/immune axis. Because this SNP is in linkage disequilibrium with other SNPs associated with several infectious diseases, we addressed the combined influence of p53 and the SNP on downstream inflammatory signaling in response to a TLR8 cognate ssRNA ligand. Using human primary lymphocytes, p53 induction by chemotherapeutic agents such as ionizing radiation caused SNP-dependent synergistic increases in IL-6 following incubation with an ssRNA ligand, as well as TLR8 RNA and protein expression along with p53 binding at the TLR-p53 SNP site. Because TLR8 is X-linked, the increases were generally reduced in heterozygous females. We found a corresponding association of the p53-responsive allele with RSV disease severity in infants hospitalized with RSV infection. We conclude that p53 can strongly influence TLR8-mediated immune responses and that knowledge of the p53-responsive SNP can inform diagnosis and prognosis of RSV disease and other diseases that might have a TLR8 component, including cancer.

Authors

Daniel Menendez, Joyce Snipe, Jacqui Marzec, Cynthia L. Innes, Fernando P. Polack, Mauricio T. Caballero, Shepherd H. Schurman, Steven R. Kleeberger, Michael A. Resnick

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Abstract

Fibronectin in the vascular wall promotes inflammatory activation of the endothelium during vascular remodeling and atherosclerosis. These effects are mediated in part by fibronectin binding to integrin α5, which recruits and activates phosphodiesterase 4D5 (PDE4D5) by inducing its dephosphorylation on an inhibitory site, S651. Active PDE then hydrolyzes antiinflammatory cAMP to facilitate inflammatory signaling. To test this model in vivo, we mutated the integrin binding site of PDE4D5 in mice. This mutation reduced endothelial inflammatory activation in atherosclerosis-prone regions of arteries and, in a hyperlipidemia model, reduced atherosclerotic plaque size while increasing markers of plaque stability. We then investigated the mechanism of PDE4D5 activation. Proteomics identified the PP2A regulatory subunit B55α as the factor recruiting PP2A to PDE4D5. The B55α-PP2A complex localized to adhesions and directly dephosphorylated PDE4D5. This interaction also, unexpectedly, stabilized the PP2A-B55α complex. The integrin-regulated, proatherosclerotic transcription factor Yap was also dephosphorylated and activated through this pathway. PDE4D5 therefore mediated matrix-specific regulation of endothelial cell phenotype via an unconventional adapter role, assembling and anchoring a multifunctional PP2A complex that has other targets. We believe these results may have widespread consequences for the control of cell function by integrins.

Authors

Sanguk Yun, Rui Hu, Melanie E. Schwaemmle, Alexander N. Scherer, Zhenwu Zhuang, Anthony J. Koleske, David C. Pallas, Martin A. Schwartz

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Abstract

Deciphering novel pathways that regulate liver lipid content has profound implications for understanding the pathophysiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Recent evidence suggests that the nuclear envelope is a site of regulation of lipid metabolism, but there is limited appreciation of the responsible mechanisms and molecular components within this organelle. We showed that conditional hepatocyte deletion of the inner nuclear membrane protein lamina-associated polypeptide 1 (LAP1) causes defective VLDL secretion and steatosis, including intranuclear lipid accumulation. LAP1 binds to and activates torsinA, an AAA+ ATPase that resides in the perinuclear space and continuous main ER. Deletion of torsinA from mouse hepatocytes caused even greater reductions in VLDL secretion and profound steatosis. Mice from both of the mutant lines studied developed hepatic steatosis and subsequent steatohepatitis on a regular chow diet in the absence of whole-body insulin resistance or obesity. Our results establish an essential role for the nuclear envelope–localized torsinA-LAP1 complex in hepatic VLDL secretion and suggest that the torsinA pathway participates in the pathophysiology of NAFLD.

Authors

Ji-Yeon Shin, Antonio Hernandez-Ono, Tatyana Fedotova, Cecilia Östlund, Michael J. Lee, Sarah B. Gibeley, Chun-Chi Liang, William T. Dauer, Henry N. Ginsberg, Howard J. Worman

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Abstract

There has been great progress in ocular gene therapy, but delivery of viral vectors to the retinal pigmented epithelium (RPE) and retina can be challenging. Subretinal injection, the preferred route of delivery for most applications, requires a surgical procedure that has risks. Herein we report a novel gene therapy delivery approach, suprachoroidal injection of AAV8 vectors, which is less invasive and could be done in an outpatient setting. Two weeks after suprachoroidal injection of AAV8.GFP in rats, GFP fluorescence covered 18.9% of RPE flat mounts and extended entirely around sagittal and transverse sections in RPE and photoreceptors. After 2 suprachoroidal injections of AAV8.GFP, GFP fluorescence covered 30.5% of RPE flat mounts. Similarly, widespread expression of GFP occurred in nonhuman primate and pig eyes after suprachoroidal injection of AAV8.GFP. Compared with subretinal injection in rats of RGX-314, an AAV8 vector expressing an anti-VEGF Fab, suprachoroidal injection of the same dose of RGX-314 resulted in similar expression of anti-VEGF Fab and similar suppression of VEGF-induced vascular leakage. Suprachoroidal AAV8 vector injection provides a noninvasive outpatient procedure to obtain widespread transgene expression in retina and RPE.

Authors

Kun Ding, Jikui Shen, Zibran Hafiz, Sean F. Hackett, Raquel Lima e Silva, Mahmood Khan, Valeria E. Lorenc, Daiqin Chen, Rishi Chadha, Minie Zhang, Sherri Van Everen, Nicholas Buss, Michele Fiscella, Olivier Danos, Peter A. Campochiaro

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Abstract

Checkpoint blockade antibodies have been approved as immunotherapy for multiple types of cancer, but the response rate and efficacy are still limited. There are few immunogenic cell death–inducing (ICD-inducing) drugs available that can kill cancer cells, enhance tumor immunogenicity, increase in vivo immune infiltration, and thereby boost a tumor response to immunotherapy. So far, the ICD markers have been identified as the few immunostimulating characteristics of dead cells, but whether the presence of such ICD markers on tumor cells translates into enhanced antitumor immunity in vivo is still being investigated. To identify anticancer drugs that could induce tumor cell death and boost T cell response, we performed drug screenings based on both an ICD reporter assay and a T cell activation assay. We showed that teniposide, a DNA topoisomerase II inhibitor, could induce high-mobility group box 1 (HMGB1) release and type I IFN signaling in tumor cells and that teniposide-treated tumor cells could activate antitumor T cell response both in vitro and in vivo. Mechanistically, teniposide induced tumor cell DNA damage and innate immune signaling, including NF-κB activation and stimulator of IFN genes–dependent (STING-dependent) type I IFN signaling, both of which contribute to the activation of dendritic cells and subsequent T cells. Furthermore, teniposide potentiated the antitumor efficacy of anti-PD1 in multiple types of mouse tumor models. Our findings showed that teniposide could trigger tumor immunogenicity and enabled a potential chemoimmunotherapeutic approach to potentiating the therapeutic efficacy of anti-PD1 immunotherapy.

Authors

Zining Wang, Jiemin Chen, Jie Hu, Hongxia Zhang, Feifei Xu, Wenzhuo He, Xiaojuan Wang, Mengyun Li, Wenhua Lu, Gucheng Zeng, Penghui Zhou, Peng Huang, Siyu Chen, Wende Li, Liang-ping Xia, Xiaojun Xia

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Abstract

BACKGROUND Spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein. New SMN-enhancing therapeutics are associated with variable clinical benefits. Limited knowledge of baseline and drug-induced SMN levels in disease-relevant tissues hinders efforts to optimize these treatments.METHODS SMN mRNA and protein levels were quantified in human tissues isolated during expedited autopsies.RESULTS SMN protein expression varied broadly among prenatal control spinal cord samples, but was restricted at relatively low levels in controls and SMA patients after 3 months of life. A 2.3-fold perinatal decrease in median SMN protein levels was not paralleled by comparable changes in SMN mRNA. In tissues isolated from nusinersen-treated SMA patients, antisense oligonucleotide (ASO) concentration and full-length (exon 7 including) SMN2 (SMN2-FL) mRNA level increases were highest in lumbar and thoracic spinal cord. An increased number of cells showed SMN immunolabeling in spinal cord of treated patients, but was not associated with an increase in whole-tissue SMN protein levels.CONCLUSIONS A normally occurring perinatal decrease in whole-tissue SMN protein levels supports efforts to initiate SMN-inducing therapies as soon after birth as possible. Limited ASO distribution to rostral spinal and brain regions in some patients likely limits clinical response of motor units in these regions for those patients. These results have important implications for optimizing treatment of SMA patients and warrant further investigations to enhance bioavailability of intrathecally administered ASOs.FUNDING SMA Foundation, SMART, NIH (R01-NS09677, R01-NS062269), Ionis Pharmaceuticals, and PTC Therapeutics. Biogen provided support for absolute real-time RT-PCR.

Authors

Daniel M. Ramos, Constantin d’Ydewalle, Vijayalakshmi Gabbeta, Amal Dakka, Stephanie K. Klein, Daniel A. Norris, John Matson, Shannon J. Taylor, Phillip G. Zaworski, Thomas W. Prior, Pamela J. Snyder, David Valdivia, Christine L. Hatem, Ian Waters, Nikhil Gupte, Kathryn J. Swoboda, Frank Rigo, C. Frank Bennett, Nikolai Naryshkin, Sergey Paushkin, Thomas O. Crawford, Charlotte J. Sumner

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Abstract

Authors

Steven B. Abramson, Paul J. Anderson, Jill P. Buyon, Bruce N. Cronstein, Thoru Pederson, Mark R. Philips, Charles N. Serhan

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Abstract

Novel approaches for adjunctive therapy are urgently needed for infections complicated by antibiotic-resistant pathogens and for patients with compromised immunity. Necrotizing fasciitis (NF) is a destructive skin and soft tissue infection. Despite treatment with systemic antibiotics and radical debridement of necrotic tissue, lethality remains high. The key iron regulatory hormone hepcidin was originally identified as a cationic antimicrobial peptide (AMP), but its putative expression and role in the skin, a major site of AMP production, has never been investigated. We report here that hepcidin production is induced in the skin of patients with Group A Streptococcal (GAS) NF. In a GAS-induced NF model, mice lacking hepcidin in keratinocytes failed to restrict systemic spread of infection from an initial tissue focus. Unexpectedly, this effect was due its ability to promote production of the CXCL1 chemokine by keratinocytes resulting in neutrophil recruitment. Unlike CXCL1, hepcidin is resistant to degradation by major GAS proteases and could therefore serve as a reservoir to maintain steady state levels of CXCL1 in infected tissue. Finally, injection of synthetic hepcidin at the site of infection can limit or completely prevent systemic spread of GAS infection suggesting that hepcidin agonists could have a therapeutic role in NF.

Authors

Mariangela Malerba, Sabine Louis, Sylvain Cuvellier, Srikanth Mairpady Shambat, Camille Hua, Camille Gomart, Agnès Fouet, Nicolas Ortonne, Jean-Winoc Decousser, Annelies S. Zinkernagel, Jacques R.R. Mathieu, Carole Peyssonnaux

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Abstract

Polymorphonuclear neutrophils (PMNs) are increasingly recognized to influence solid tumor development, but why their effects are so context-dependent and even frequently divergent remains poorly understood. Using an autochthonous mouse model of uterine cancer and the administration of respiratory hyperoxia as a means to improve tumor oxygenation, we provide in vivo evidence that hypoxia is a potent determinant of tumor-associated PMN phenotypes and direct PMN-tumor cell interactions. Upon relief of tumor hypoxia, PMNs were recruited less intensely to the tumor-bearing uterus but the recruited cells much more effectively killed tumor cells, an activity our data moreover suggested was mediated via their production of NADPH oxidase-derived reactive oxygen species and MMP-9. Simultaneously, their ability to promote tumor cell proliferation, which appeared mediated via their production of neutrophil elastase, was rendered less effective. Relieving tumor hypoxia thus greatly improved net PMN-dependent tumor control, leading to a massive reduction in tumor burden. Remarkably, this outcome was T cell-independent. Together, these findings identify key hypoxia-regulated molecular mechanisms through which PMNs directly induce tumor cell death and proliferation in vivo and suggest that the contrasting properties of PMNs in different tumor settings may in part reflect the effects of hypoxia on direct PMN-tumor cell interactions.

Authors

Karim Mahiddine, Adam Blaisdell, Stephany Ma, Amandine Créquer-Grandhomme, Clifford A. Lowell, Adrian Erlebacher

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Abstract

Patients with bladder cancer (BCa) with clinical lymph node (LN) metastasis have extremely poor prognosis. VEGF-C has been demonstrated to play vital roles in LN metastasis in BCa. However, approximately 20% of BCa with LN metastasis exhibits low VEGF-C expression, suggesting a VEGF-C-independent mechanism for LN metastasis of BCa. Herein, we demonstrated that BCa cell-secreted exosomes-mediated lymphangiogenesis promoted LN metastasis in BCa, which was in a VEGF-C-independent manner. We identified an exosomal long noncoding RNA (lncRNA), termed lymph node metastasis-associated transcript 2 (LNMAT2), stimulated HLEC tube formation and migration in vitro and enhanced tumor lymphangiogenesis and LN metastasis in vivo. Mechanistically, LNMAT2 was loaded to BCa cell-secreted exosomes by directly interacting with heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1). Subsequently, exosomal LNMAT2 was internalized by HLECs and epigenetically upregulated prospero homeobox 1 (PROX1) expression by recruitment of hnRNPA2B1 and increasing the H3K4 trimethylation level in the PROX1 promoter, ultimately resulting in lymphangiogenesis and lymphatic metastasis. Therefore, our findings highlight a VEGF-C-independent mechanism of exosomal lncRNA-mediated LN metastasis and identify LNMAT2 as a therapeutic target for LN metastasis in BCa.

Authors

Changhao Chen, Yuming Luo, Wang He, Yue Zhao, Yao Kong, Hongwei Liu, Guangzheng Zhong, Yuting Li, Jun Li, Jian Huang, Rufu Chen, Tianxin Lin

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Abstract

Potentiating radiotherapy and chemotherapy by inhibiting DNA damage repair is proposed as a therapeutic strategy to improve outcomes for patients with solid tumors. However, this approach risks enhancing normal tissue toxicity as much as tumor toxicity, thereby limiting its translational impact. Using NU5455, a newly-identified highly-selective oral inhibitor of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity, we found that it was indeed possible to preferentially augment the effect of targeted-radiotherapy on human orthotopic lung tumors without influencing acute DNA-damage or a late radiation-induced toxicity (fibrosis) to normal mouse lung. Furthermore, while NU5455 administration increased both the efficacy and toxicity of a parenterally-administered topoisomerase inhibitor, it enhanced the activity of doxorubicin released locally in liver tumor xenografts without inducing any adverse effect. This strategy is particularly relevant to hepatocellular cancer which is treated clinically with localized drug-eluting beads and for which DNA-PKcs activity is reported to confer resistance to treatment. We conclude that transient pharmacological inhibition of DNA-PKcs activity is effective and tolerable when combined with localized DNA-damaging therapies and thus has promising clinical potential.

Authors

Catherine E. Willoughby, Yanyan Jiang, Huw D. Thomas, Elaine Willmore, Suzanne Kyle, Anita Wittner, Nicole Phillips, Yan Zhao, Susan J. Tudhope, Lisa Prendergast, Gesa Junge, Luiza Madia Lourenco, M. Raymond V. Finlay, Paul Turner, Joanne M. Munck, Roger J. Griffin, Tommy Rennison, James Pickles, Celine Cano, David R. Newell, Helen L. Reeves, Anderson J. Ryan, Stephen R. Wedge

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Abstract

Diabetes is a common complication of cystic fibrosis (CF) that affects approximately 20% of adolescents and 40% to 50% of adults with CF. The age-at-onset of CF-related diabetes (marked by clinical diagnosis and treatment initiation) is an important measure of the disease process. DNA variants associated with age-at-onset of CFRD reside in and near SLC26A9. Deep sequencing of the SLC26A9 gene in 762 individuals with CF revealed that two common DNA haplotypes formed by the risk variants account for the association with diabetes (high risk, P-value: 4.34E-3; low risk, P-value: 1.14E-3). Single-cell RNA (scRNA) sequencing indicated that SLC26A9 is predominantly expressed in pancreatic ductal cells, and frequently co-expressed with CFTR along with transcription factors that have binding sites 5′ of SLC26A9. These findings replicated upon re-analysis of scRNA data from 4 independent studies. DNA fragments derived from the 5′ region of SLC26A9 bearing variants from the low risk haplotype generated 12% to 20% higher levels of expression in PANC-1 and CFPAC-1 cells compared to the high risk haplotype (P-values: 2.00E-3 to 5.15E-9). Taken together, our findings indicate that an increase in SLC26A9 expression in ductal cells of the pancreas delays the age-at-onset of diabetes, thereby suggesting a CFTR-agnostic treatment for a major complication of CF.

Authors

Anh-Thu N. Lam, Melis A. Aksit, Briana Vecchio-Pagan, Celeste A. Shelton, Derek L. Osorio, Arianna F. Anzmann, Loyal A. Goff, David C. Whitcomb, Scott M. Blackman, Garry R. Cutting

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October 2019

October 2019 Issue

On the cover:
Targeting APOC3 prevents diabetes-associated atherogenesis

The risk of developing atherosclerosis and cardiovascular disease is greater in patients with type 1 diabetes mellitus (T1DM), and the roles of lipoprotein-regulating proteins like APOC3 are relatively unexplored. In this issue, Kanter et al. observed that elevated serum APOC3 levels are a strong predictor of coronary artery disease incidents in T1DM patients. An APOC3-targeting antisense oligonucleotide (ASO) mitigated APOC3 elevations in diabetic mouse models as well as prevented accelerated atherogenesis, supporting APOC3-targeting strategies as potential interventions for T1DM-associated cardiovascular disease. On the cover, a mouse atherosclerotic lesion (Movat’s pentachrome stain), an ECG trace, and a heart-shaped lipoprotein particle highlight APOC3’s role in T1DM-linked cardiovascular disease. Image credit: Jenny Kanter and Karin Bornfeldt.

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October 2019 JCI This Month

JCI This Month is a digest of the research, reviews, and other features published each month.

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Review Series - More

Mechanisms Underlying the Metabolic Syndrome

Series edited by Philipp E. Scherer

Obesity often occurs with a quintessential array of metabolic abnormalities: elevations in blood pressure, visceral fat, and circulating blood lipids, and, importantly, insulin resistance. Together, this constellation of conditions constitutes the metabolic syndrome and forecasts an individual’s increased risk of developing cardiovascular diseases and type 2 diabetes. Although metabolic syndrome presents as dysfunction across multiple tissues, its onset stems from pathological increases in adipose tissue. The 9 review in this series, conceptualized by series editor Philipp Scherer, delve into the complex biology underlying the metabolic syndrome. These reviews address adipocyte and beta cell dysfunction in the metabolic syndrome; the functions of adipose tissue fibrosis, the microbiome, and exosomal communication in obesity; and the concepts we use to define metabolic health.

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