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Abstract
Gonorrhea is a sexually transmitted infection with 87 million new cases per year globally. Increasing antibiotic resistance has severely limited treatment options. A mechanism that Neisseria gonorrhoeae uses to evade complement attack is binding of the complement inhibitor C4b-binding protein (C4BP). We screened 107 PorB1a and 83 PorB1b clinical isolates randomly selected from a Swedish strain collection over the last 10 years and noted that 96/107 (89.7%) PorB1a and 16/83 (19.3%) PorB1b bound C4BP; C4BP binding significantly correlated with the ability to evade complement-dependent killing (r = 0.78; p<0.0001). We designed two chimeric proteins that fused C4BP domains to the backbone of immunoglobulins IgG or IgM (C4BP-IgG; C4BP-IgM) with the aim of enhancing complement activation and killing of gonococci. Both proteins bound gonococci (Kd C4BP-IgM = 2.4 nM; Kd C4BP-IgG 981 nM), but only hexameric C4BP-IgM efficiently out-competed heptameric C4BP from bacterial surface resulting in enhanced complement deposition and bacterial killing. Furthermore, C4BP-IgM significantly attenuated the duration and burden of colonization of two C4BP-binding gonococcal isolates, but not a C4BP non-binding strain in the mouse vaginal colonization model using human factor H/C4BP transgenic mice. Our pre-clinical data present C4BP-IgM as an adjunctive to conventional antimicrobials for the treatment of gonorrhea.
Authors
Serena Bettoni, Jutamas Shaughnessy, Karolina Maziarz, David Ermert, Sunita Gulati, Bo Zheng, Matthias Mörgelin, Susanne Jacobsson, Kristian Riesbeck, Magnus Unemo, Sanjay Ram, Anna M. Blom
Abstract
Mitochondrial quality control (MQC) is crucial for regulating central nervous system homeostasis and its disruption has been implicated in the pathogenesis of some of the most common neurodegenerative diseases. In healthy tissues, the maintenance of MQC depends upon an exquisite balance between mitophagy (removal of damaged mitochondria by autophagy) and biogenesis (de-novo synthesis of mitochondria). Here, we show that mitophagy is disrupted in diabetic retinopathy (DR) and decoupled from mitochondrial biogenesis during the progression of the disease. Diabetic retinas from human post-mortem donors and experimental mice exhibit a net loss of mitochondrial contents during the early stages of the disease process. Using novel diabetic mitophagy-reporter mice (mitoQC-Ins2Akita) alongside pMitoTimer (a molecular clock to address mitochondrial-age dynamics), we demonstrate that mitochondrial loss arose due to an inability of mitochondrial biogenesis to compensate for diabetes-exacerbated mitophagy. However, as diabetes duration increases, Pink1-dependent mitophagy deteriorates, leading to the build-up of mitochondria primed for degradation in DR. Impairment of mitophagy during prolonged diabetes is linked with the development of retinal senescence, a phenotype that blunted hyperglycaemia-induced mitophagy in mitoQC primary Müller cells. Our findings suggest that normalizing mitochondrial turnover may preserve MQC and provide novel therapeutic options for the management of DR-associated complications.
Authors
Jose R. Hombrebueno, Lauren Cairns, Louise R. Dutton, Timothy J. Lyons, Derek P. Brazil, Paul Moynagh, Tim M. Curtis, Heping Xu
Abstract
Diabetic foot ulcers (DFUs) are a life-threatening disease that often result in lower limb amputations and a shortened lifespan. Current treatment options are limited and often not efficacious, raising the need for new therapies. To investigate the therapeutic potential of topical statins to restore healing in patients with DFUs, we performed next generation sequencing on mevastatin-treated primary human keratinocytes. We found that mevastatin activated and modulated the EGF signaling to trigger an anti-proliferative and pro-migratory phenotype, suggesting that statins may shift DFUs from a hyper-proliferative phenotype to a pro-migratory phenotype in order to stimulate healing. Furthermore, mevastatin induced a migratory phenotype in primary human keratinocytes through EGF-mediated activation of Rac1, resulting in actin cytoskeletal reorganization and lamellipodia formation. Interestingly, the EGF receptor is downregulated in tissue biopsies from patients with DFUs. Mevastatin restored EGF signaling in DFUs through disruption of caveolae to promote keratinocyte migration, which was confirmed by caveolin-1 (Cav1) overexpression studies. We conclude that topical statins may have considerable therapeutic potential as a treatment option for patients with DFUs and offer an effective treatment for chronic wounds that can be rapidly translated to clinical use.
Authors
Andrew P. Sawaya, Ivan Jozic, Rivka C. Stone, Irena Pastar, Andjela N. Egger, Olivera Stojadinovic, George D. Glinos, Robert S. Kirsner, Marjana Tomic-Canic
Abstract
Muscle contractures are a prominent and disabling feature of many neuromuscular disorders, including the two most common forms of childhood neurologic dysfunction: neonatal brachial plexus injury (NBPI) and cerebral palsy (CP). There are currently no treatment strategies to directly alter the contracture pathology, as the pathogenesis of these contractures is unknown. We previously showed in a mouse model of NBPI that contractures result from impaired longitudinal muscle growth. Current presumed explanations for growth impairment in contractures focus on the dysregulation of muscle stem cells (MuSCs), which differentiate and fuse to existing myofibers during growth, as this process has classically been thought to control muscle growth during the neonatal period. Here, we demonstrate in a mouse model of NBPI that denervation does not prevent myonuclear accretion and that reduction of myonuclear number has no effect on functional muscle length or contracture development, providing definitive evidence that altered myonuclear accretion is not a driver of neuromuscular contractures. In contrast, we observed elevated levels of protein degradation in NBPI muscle, and we demonstrate that contractures can be pharmacologically prevented with the proteasome inhibitor, bortezomib. These studies provide the first strategy to prevent neuromuscular contractures by correcting the underlying deficit in longitudinal muscle growth.
Authors
Sia Nikolaou, Alyssa A.W. Cramer, Liangjun Hu, Qingnian Goh, Douglas P. Millay, Roger Cornwall
Abstract
Angiogenesis is a key process that allows nutrient uptake and cellular trafficking and is co-opted in cancer to enable tumor growth and metastasis. Recently, extracellular vesicles (EVs) have been shown to promote angiogenesis; however, it is unclear what unique features EVs contribute to the process. Here, we studied the role of EVs derived from head and neck squamous cell carcinoma (HNSCC) in driving tumor angiogenesis. Small EVs (SEVs), in the size range of exosomes (50-150 nm), induced angiogenesis both in vitro and in vivo. Proteomic analysis of HNSCC SEVs revealed the cell-cell signaling receptor EPHB2 as a promising candidate cargo to promote angiogenesis. Analysis of TCGA RNA-Seq and patient tissue microarray data further identified EPHB2 overexpression in HNSCC tumors to be associated with poor patient prognosis and tumor angiogenesis, especially in the context of overexpression of the exosome secretion regulator cortactin. Functional experiments revealed that EPHB2 expression in SEVs regulates angiogenesis both in vitro and in vivo and that EPHB2 carried by SEVs stimulates ephrin-B reverse signaling, inducing STAT3 phosphorylation. A STAT3 inhibitor greatly reduced SEV-induced angiogenesis. These data suggest a novel model in which EVs uniquely promote angiogenesis by transporting Eph transmembrane receptors to non-adjacent endothelial cells to induce ephrin reverse signaling.
Authors
Shinya Sato, Suhas Vasaikar, Adel Eskaros, Young Kim, James S. Lewis, Bing Zhang, Andries Zijlstra, Alissa M. Weaver
Abstract
CADASIL leads to premature stroke and vascular dementia. Mechanism-specific therapies for this aggressive cerebral small vessel disease are lacking. CADASIL is caused by NOTCH3 mutations that influence vascular smooth muscle cell (VSMC) function through unknown processes. We investigated molecular mechanisms underlying the vasculopathy in CADASIL focusing on ER stress and RhoA/Rho kinase (ROCK). Peripheral small arteries and VSMCs were isolated from gluteal biopsies of CADASIL patients and mesentery of TgNotch3R169C mice (CADASIL model). CADASIL vessels exhibited impaired vasorelaxation, blunted vasoconstriction and hypertrophic remodelling. Expression of NOTCH3 and ER stress target genes was amplified and ER stress response, Rho kinase activity, superoxide production and cytoskeletal-associated protein phosphorylation were increased in CADASIL, processes associated with Nox5 upregulation. Aberrant vascular responses and signalling in CADASIL were ameliorated by inhibitors of Notch3 (gamma-secretase inhibitor), Nox5 (mellitin), ER stress (4-PBA) and ROCK (fasudil). Observations in human CADASIL were recapitulated in TgNotch3R169C mice. These findings indicate that vascular dysfunction in CADASIL involves ER stress/ROCK interplay driven by Notch3-induced Nox5 activation and that NOTCH3 mutation-associated vascular pathology, typical in cerebral vessels, also manifests peripherally. We define Notch3-Nox5/ERstress/ROCK signaling as a novel putative mechanism-specific target and suggest that peripheral artery responses may be an accessible biomarker in CADASIL.
Authors
Karla B. Neves, Adam P. Harvey, Fiona Moreton, Augusto C. Montezano, Francisco J. Rios, Rhéure Alves-Lopes, Aurelie Nguyen Dinh Cat, Paul Rocchiccioli, Christian Delles, Anne Joutel, Keith Muir, Rhian M. Touyz
Abstract
The choroid plexus (ChP) is a highly vascularized tissue found in the brain ventricles, with an apical epithelial cell layer surrounding fenestrated capillaries. It is responsible for the production of most of the cerebrospinal fluid (CSF) in the ventricular system, subarachnoid space, and central canal of the spinal cord, while also constituting the blood-CSF barrier (BCSFB). In addition, epithelial cells of the choroid plexus (EChP) synthesize neurotrophic factors and other signaling molecules that are released into the CSF. Here we show that insulin is produced in EChP of mice and humans, and its expression and release are regulated by serotonin. Insulin mRNA and immune-reactive protein, including C-peptide, are present in EChP, as detected by several experimental approaches, and in much higher levels than any other brain region and non-pancreatic peripheral tissues. Moreover, insulin is produced in primary cultured mouse EChP, and its release, albeit Ca2+-sensitive, is not regulated by glucose. Instead, activation of the 5HT2C receptor by serotonin treatment led to activation of IP3-sensitive channels and Ca2+ mobilization from intracellular storage, leading to insulin secretion. In vivo depletion of brain serotonin in the dorsal raphe nucleus negatively affected insulin expression in the ChP, suggesting an endogenous modulation of ChP insulin by serotonin. Therefore, for the first time to our knowledge, here we show that insulin is produced by EChP in the brain, and its release is modulated at least by serotonin, and not glucose.
Authors
Caio Henrique Mazucanti, Qing-Rong Liu, Doyle Lang, Nicholas Huang, Jennifer F. O’Connell, Simonetta Camandola, Josephine M. Egan
Abstract
Mitophagy, by maintaining mitochondrial quality control, plays a key role in maintaining kidney function and is impaired in pathologic states. Macrophages are well-known for their pathogenic role in kidney fibrosis. Here, we report that PINK1/Parkin-mediated mitophagy in macrophages is compromised in experimental and human kidney fibrosis. We demonstrate downregulation of mitophagy regulators, mitofusin-2 (MFN2) and Parkin, downstream of PINK1 in kidney fibrosis. Loss of either Pink1 or Prkn promoted renal extracellular matrix accumulation and frequency of profibrotic/M2 macrophages. Pink1-/- or Prkn-/- bone-marrow-derived macrophages (BMDMs) showed enhanced expression of rictor. Mitochondria from TGF-β1-treated Pink1-/- BMDMs exhibited increased superoxide levels, and reduced respiration and ATP production. In addition, mitophagy in macrophages involves PINK1-mediated phosphorylation of downstream MFN2 and MFN2-facilitated recruitment of Parkin to damaged mitochondria, and macrophage-specific deletion of Mfn2 aggravates kidney fibrosis. Moreover, mitophagy regulators were downregulated in human CKD kidney and TGF-β1-treated human renal macrophages, whereas Mdivi1 treatment suppressed mitophagy mediators and promoted fibrotic response. Taken together, our study is the first to demonstrate that macrophage mitophagy plays a protective role against kidney fibrosis via regulating PINK1/MFN2/Parkin-mediated pathway.
Authors
Divya Bhatia, Kuei-Pin Chung, Kiichi Nakahira, Edwin Patino, Michelle C. Rice, Lisa K. Torres, Thangamani Muthukumar, Augustine M.K. Choi, Oleh M. Akchurin, Mary E. Choi
Abstract
Cardiomyopathies are complex heart muscle diseases that can be inherited or acquired. Dilated cardiomyopathy can result from mutations in LMNA, encoding the nuclear intermediate filament proteins lamin A/C. Some LMNA mutations lead to accumulation of the lamin A precursor, prelamin A, which is disease causing in a number of tissues yet its impact upon the heart is unknown. Here we discovered myocardial prelamin A accumulation occurred in a case of dilated cardiomyopathy and show that a novel mouse model of cardiac specific prelamin A accumulation exhibited a phenotype consistent with ‘inflammatory cardiomyopathy’ which we observed to be similar to HIV associated cardiomyopathy, an acquired disease state. Numerous HIV protease therapies are known to inhibit ZMPSTE24, the enzyme responsible for prelamin A processing, and we confirmed that accumulation of prelamin A occurred in HIV+ patient cardiac biopsies. These findings: (1) confirm a unifying pathological role for prelamin A common to genetic and acquired cardiomyopathies; (2) have implications for the management of HIV patients with cardiac disease suggesting protease inhibitors should be replaced with alternative therapies i.e. non-nucleoside reverse transcriptase inhibitors; and (3) suggest that targeting inflammation may be a useful treatment strategy for certain forms of inherited cardiomyopathy.
Authors
Daniel Brayson, Andrea Frustaci, Romina Verardo, Cristina Chimenti, Matteo Antonio Russo, Robert Hayward, Sadia Munir Ahmad, Gema Vizcay-Barrena, Andrea Protti, Peter S. Zammit, Cristobal G. dos Remedios, Elisabeth Ehler, Ajay M. Shah, Catherine M. Shanahan
Abstract
The transcriptional activator IκBζ is a key regulator of psoriasis, but which cells mediate its pathogenic effect remains unknown. Here we found that IκBζ expression in keratinocytes triggers not only skin lesions, but also systemic inflammation in mouse psoriasis models. Specific depletion of IκBζ in keratinocytes was sufficient to suppress the induction of imiquimod- or IL-36-mediated psoriasis. Moreover, IκBζ ablation in keratinocytes prevented the onset of psoriatic lesions and systemic inflammation in keratinocyte-specific IL-17A transgenic mice. Mechanistically, this psoriasis protection was mediated by the fact that IκBζ deficiency in keratinocytes abrogated the induction of specific pro-inflammatory target genes, including Cxcl5, Cxcl2, Csf2 and Csf3, in response to IL-17A or IL-36. These IκBζ-dependent genes trigger the generation and recruitment of neutrophils and monocytes that are needed for skin inflammation. Consequently, our data uncover a surprisingly pivotal role of keratinocytes and keratinocyte-derived IκBζ as key mediators of psoriasis and psoriasis-related systemic inflammation.
Authors
Sebastian Lorscheid, Anne Müller, Jessica Löffler, Claudia Resch, Philip Bucher, Florian C. Kurschus, Ari Waisman, Knut Schäkel, Stephan Hailfinger, Klaus Schulze-Osthoff, Daniela Kramer
Abstract
Mice homozygous for a hypomorphic allele of DNA replication factor minichromosome maintenance protein 2 (designated Mcm2cre/cre) develop precursor T-cell lymphoblastic leukemia/lymphoma (pre-T LBL) with 4-32 small interstitial deletions per tumor. Mice that express a NUP98-HOXD13 (NHD13) transgene develop multiple types of leukemia, including myeloid, T and B lymphocyte. All Mcm2cre/creNHD13+ mice develop pre-T LBL, and 26% develop an unrelated, concurrent B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Copy Number Alteration (CNA) analysis demonstrated that pre-T LBL were characterized by homozygous deletions of Pten and Tcf3, and partial deletions of Notch1 leading to Notch1 activation. In contrast, BCP-ALL were characterized by recurrent deletions involving Pax5 and Ptpn1, and copy number gain of Abl1 and Nup214 resulting in a Nup214-Abl1 fusion. We present a model in which Mcm2 deficiency leads to replicative stress, DNA double strand breaks, and resultant CNAs due to errors in DNA DSB repair. CNAs which involve critical oncogenic pathways are then selected in vivo as malignant lymphoblasts, due to a fitness advantage. Some CNAs, such as those involving Abl1 and Notch1, represent attractive targets for therapy.
Authors
Mianmian Yin, Timour Baslan, Robert L. Walker, Yuelin J. Zhu, Amy Freeland, Toshihiro Matsukawa, Sriram Sridharan, André Nussenzweig, Steven C. Pruitt, Scott W. Lowe, Paul S. Meltzer, Peter D. Aplan
Abstract
Von Hippel–Lindau (Vhl) protein inhibits hypoxia-inducible factor (Hif), yet its deletion in murine retina does not cause the extensive angiogenesis expected with Hif induction. The mechanism is unclear. Here we show that retinoblastoma tumor suppressor (Rb1) constrains expression of Hif target genes in the Vhl-/- retina. Deleting Rb1 induced extensive retinal neovascularization and autophagic ablation of photoreceptors in the Vhl-/- retina. RNA sequencing, ChIP and reporter assays showed Rb1 recruitment to and repression of certain Hif target genes. Activating Rb1 by deleting cyclin D1 induced a partial defect in the retinal superficial vascular plexus (SVP). Unexpectedly, removing Vhl suppressed retinoblastoma formation in murine Rb1/Rbl1-deficient retina, but generated subretinal vascular growths resembling retinal angiomatous proliferation (RAP), and retinal capillary hemangioblastoma (RCH). Most stromal cells in the RAP/RCH-like lesions were Sox9+, suggesting a Müller glia origin, and expressed Lgals3, a marker of human brain hemangioblastoma. Thus, the Rb family limit Hif target gene expression in the Vhl-/- retina, and removing this inhibitory signal generates new models for RAP and RCH.
Authors
Ran Wei, Xiang Ren, Hongyu Kong, Zhongping Lv, Yongjiang Chen, Yunjing Tang, Yujiao Wang, Lirong Xiao, Sabiha Hacibekiroglu, Chen Liang, Andras Nagy, Rod Bremner, Danian Chen
Abstract
Background: Innate immune activation impacts lung transplant outcomes. Dectin-1 is an innate receptor important for pathogen recognition. We hypothesized that genotypes reducing dectin-1 activity would be associated with infection, graft dysfunction, and death in lung transplant recipients. Methods: We assessed the rs16910526 CLEC7A gene polymorphism Y238X, which results in dectin-1 truncation, in 321 lung allograft recipients at a single institution and in 1,129 lung allograft recipients in the multi-center lung transplant outcomes group (LTOG) cohort. Differences in dectin-1 mRNA, cytokines, protein levels, immunophenotypes, and clinical factors were assessed. Results: Y238X carriers had decreased dectin-1 mRNA expression (P = 0.0001), decreased soluble dectin-1 protein concentrations in BAL (P = 0.008) and plasma (P = 0.04), and decreased monocyte surface dectin-1 (P = 0.01) compared to wild type subjects. Y238X carriers had an increased risk of fungal pathogens (HR 1.17, CI 1.0 – 1.4), an increased risk of graft dysfunction or death (HR 1.6, CI 1.0 – 2.6), as well increased mortality in the UCSF cohort (HR 1.8, CI 1.1 – 3.8) and in the LTOG cohort (HR 1.3, CI 1.1 – 1.6), compared to CLEC7A wildtype subjects. Conclusion: Increased rates of graft dysfunction and death associated with this dectin-1 polymorphism may be amplified by immunosuppression that drives higher fungal burden from compromised pathogen recognition. Funding: Project funding came from the UCSF Nina Ireland Program for Lung Health (NIPLH) Innovative Grant program, award number IK2CX001034 from the Clinical Sciences Research & Development Service of the VA Office of Research and Development, and the Joel D. Cooper Career Development Award from the International Society for Heart and Lung Transplantation.
Authors
Daniel R. Calabrese, Ping Wang, Tiffany Chong, Jonathan Hoover, Jonathan P. Singer, Dara Torgerson, Steven R. Hays, Jeffrey A. Golden, Jasleen Kukreja, Daniel Dugger, Jason D. Christie, LTOG investigators, John R. Greenland
Abstract
Previous work has reported the important links between cellular bioenergetics and the development of chronic kidney disease, highlighting the potential for targeting metabolic functions to regulate disease progression. More recently, it has been shown that alterations in fatty acid oxidation (FAO) can have an important impact on the progression of kidney disease. In this work, we demonstrate that loss of miR-33, an important regulator of lipid metabolism, can prevent the repression of FAO in fibrotic kidneys and reduce lipid accumulation. These changes were associated with a dramatic reduction in the extent of fibrosis induced in two different mouse models of kidney disease. These effects were not related to changes in circulating leukocytes, as bone marrow transplant from miR-33 deficient animals did not have a similar impact on disease progression. Most importantly, targeted delivery of miR-33 peptide nucleic acid (PNA) inhibitors to the kidney and other acidic microenvironments was accomplished using pH low insertion peptides (pHLIP) as a carrier. This was effective at both increasing the expression of factors involved in FAO and reducing the development of fibrosis. Together, these findings suggest that miR-33 may be an attractive therapeutic target for the treatment of chronic kidney disease.
Authors
Nathan L. Price, Verónica Miguel, Wen Ding, Abhishek K. Singh, Shipra Malik, Noemi Rotllan, Anna Moshnikova, Jakub Toczek, Caroline Zeiss, Mehran M. Sadeghi, Noemi Arias, Ángel Baldán, Oleg A. Andreev, Diego Rodríguez-Puyol, Raman Bahal, Yana K. Reshetnyak, Yajaira Suárez, Carlos Fernández-Hernando, Santiago Lamas
Abstract
Background: Myeloid-derived suppressor cells (MDSCs) are elevated in glioblastoma (GBM) patient circulation, present in tumor tissue, and associated with poor prognosis. While low-dose chemotherapy reduces MDSCs in preclinical models, the use of this strategy to reduce MDSCs in GBM patients has yet to be evaluated. Methods: A phase 0/1 dose-escalation clinical trial was conducted in recurrent glioblastoma patients treated 5-7 days prior to surgery with low-dose chemotherapy via capecitabine followed by concomitant low-dose capecitabine and bevacizumab. Clinical outcomes, including progression-free and overall survival, were measured, along with safety and toxicity profiles. Over the treatment time course, circulating MDSC levels were measured by multi-parameter flow cytometry, and tumor tissue immune profiles were assessed via mass cytometry time-of-flight. Results: A total of 11 patients were enrolled across escalating dose cohorts of 150, 300, and 450 mg bid. No serious adverse events related to the drug combination were observed. Compared to pre-treatment baseline, circulating MDSCs were found to be higher after surgery in the 150 mg treatment arm and lower in the 300 mg and 450 mg treatment arms. Increased cytotoxic immune infiltration was observed after low-dose capecitabine compared to untreated GBM patients in the 300 mg and 450 mg treatment arms. Conclusions: Low-dose, metronomic capecitabine in combination with bevacizumab is well tolerated in GBM patients and was associated with a reduction in circulating MDSC levels and an increase in cytotoxic immune infiltration into the tumor microenvironment. Trial registration: NCT02669173
Authors
David M. Peereboom, Tyler J. Alban, Mathew M. Grabowski, Alvaro G. Alvarado, Balint Otvos, Defne Bayik, Gustavo Roversi, Mary McGraw, Pengjing Huang, Alireza M. Mohammadi, Harley I. Kornblum, Tomas Radivoyevitch, Manmeet S. Ahluwalia, Michael A. Vogelbaum, Justin D. Lathia
Abstract
To develop a systems biology model of fibrosis progression within the human lung we performed RNAseq and microRNA analysis on 95 samples obtained from 10 idiopathic pulmonary fibrosis (IPF) and 6 control lungs. Extent of fibrosis in each sample was assessed by microCT measured alveolar surface density (ASD) and confirmed by histology. Regulatory gene expression networks were identified using linear mixed-effect models and dynamic regulatory events miner (DREM). Differential gene expression analysis identified a core set of genes increased or decreased before fibrosis was histologically evident that continued to change with advanced fibrosis. DREM generated a systems biology model of fibrosis progression (available at http: www.sb.cs.cmu.edu/IPFReg) that identified progressively divergent gene expression tracks with microRNAs and transcription factors that specifically regulate early or advanced fibrosis. We confirmed model predictions by demonstrating that expression of POU2AF1, previously unassociated with lung disease but proposed by the model as regulator, is increased in B-lymphocytes in IPF lungs and that POU2AF1 knockout mice were protected from bleomycin induced lung fibrosis. Our results reveal distinct regulation of gene expression changes in IPF tissue that remained structurally normal compared with moderate or advanced fibrosis and suggest distinct regulatory mechanisms for each stage.
Authors
John E. McDonough, Farida Ahangari, Qin Li, Siddhartha Jain, Stijn E. Verleden, Jose Herazo-Maya, Milica Vukmirovic, Giuseppe DeIuliis, Argyrios Tzouvelekis, Naoya Tanabe, Fanny Chu, Xiting Yan, Johny Verschakelen, Robert J. Homer, Dimitris V. Manatakis, Junke Zhang, Jun Ding, Karen Maes, Laurens De Sadeleer, Robin Vos, Arne Neyrinck, Panayiotis V. Benos, Ziv Bar-Joseph, Dean Tantin, James C. Hogg, Bart M. Vanaudenaerde, Wim A. Wuyts, Naftali Kaminski
Abstract
Glomerular disease is characterized by proteinuria and glomerulosclerosis, two pathologic features caused by podocyte injury and mesangial cell activation, respectively. However, whether these two events are linked remains elusive. Here, we report that sonic hedgehog (Shh) is the mediator that connects podocyte damage to mesangial activation and glomerulosclerosis. Shh was induced in glomerular podocytes in various models of proteinuric chronic kidney diseases (CKD). However, mesangial cells in the glomeruli, but not podocytes, responded to hedgehog ligand. In vitro, Shh was induced in podocytes after injury and selectively promoted mesangial cell activation and proliferation. In a mini-organ culture of isolated glomeruli, Shh promoted mesangial activation but did not affect the integrity of podocytes. Podocyte-specific ablation of Shh in vivo exhibited no effect on proteinuria after adriamycin injection but hampered mesangial activation and glomerulosclerosis. Consistently, pharmacologic blockade of Shh signaling decoupled proteinuria from glomerulosclerosis. In humans, Shh was upregulated in glomerular podocytes in patients with CKD and its circulating level was associated with glomerulosclerosis but not proteinuria. These studies demonstrate that Shh mechanistically links podocyte injury to mesangial activation in the pathogenesis of glomerular diseases. Our findings also illustrate a crucial role for podocyte-mesangial communication in connecting proteinuria to glomerulosclerosis.
Authors
Dong Zhou, Haiyan Fu, Yang Han, Lu Zhang, Shijia Liu, Lin Lin, Donna B. Stolz, Youhua Liu
Abstract
Targeted therapies and immunotherapy have shown promise in patients with non-small cell lung cancer (NSCLC). However, the majority of patients fail or become resistant to treatment, emphasizing the need for novel treatments. In this study, we confirm the prognostic value of AXL levels in NSCLC and demonstrate potent anti-tumor activity of the AXL-targeting antibody-drug conjugate enapotamab vedotin across different NSCLC subtypes in a mouse clinical trial of human NSCLC. Tumor regression or stasis was observed in 17/61 (28%) of the PDX models, and was associated with AXL mRNA expression levels. Significant single agent activity of enapotamab vedotin was validated in vivo in 9 of 10 AXL-expressing NSCLC xenograft models. In a panel of EGFR-mutant NSCLC cell lines rendered resistant to EGFR inhibitors (EGFRi) in vitro, we observed de novo or increased AXL protein expression concomitant with enapotamab vedotin-mediated cytotoxicity. Enapotamab vedotin also showed anti-tumor activity in vivo in 3 EGFR-mutant, EGFRi-resistant PDX models, including an osimertinib-resistant NSCLC PDX model. In summary, enapotamab vedotin has promising therapeutic potential in NSCLC. The safety and preliminary efficacy of enapotamab vedotin are currently being evaluated in the clinic across multiple solid tumor types, including NSCLC.
Authors
Louise A. Koopman, Mikkel G. Terp, Gijs G. Zom, Maarten L. Janmaat, Kirstine Jacobsen, Elke Gresnigt - Van den Heuvel, Marcel Brandhorst, Ulf Forssmann, Frederik M. de Bree, Nora Pencheva, Andreas Lingnau, Maria A. Zipeto, Paul W.H.I. Parren, Esther C.W. Breij, Henrik J. Ditzel
Abstract
Background. The presence of an early repolarization pattern (ERP) on the surface electrocardiogram (ECG) is associated with risk of ventricular fibrillation and sudden cardiac death. Family studies have shown that ERP is a highly heritable trait but molecular genetic determinants are unknown. Methods. To identify genetic susceptibility loci for ERP, we performed a GWAS and meta-analysis in 2,181 cases and 23,641 controls of European ancestry. Results. We identified a genome-wide significant (p<5E-8) locus in the KCND3 (potassium voltage gated channel subfamily D member 3) gene that was successfully replicated in additional 1,124 cases and 12,510 controls. A subsequent joint meta-analysis of the discovery and replication cohorts identified rs1545300 as the lead SNP at the KCND3 locus (OR 0.82 per minor T allele, p=7.7E-12), but did not reveal additional loci. Co-localization analyses indicate causal effects of KCND3 gene expression levels on ERP in both cardiac left ventricle and tibial artery. Conclusions. In this study we identified for the first time a genome-wide significant association of a genetic variant with ERP. Our findings of a locus in the KCND3 gene not only provide insights into the genetic determinants but also into the pathophysiological mechanism of ERP, discovering a promising candidate for functional studies. Funding. For detailed information per study, see Acknowledgments.
Authors
Alexander Teumer, Teresa Trenkwalder, Thorsten Kessler, Yalda Jamshidi, Marten E. van den Berg, Bernhard Kaess, Christopher P. Nelson, Rachel Bastiaenen, Marzia De Bortoli, Alessandra Rossini, Isabel Deisenhofer, Klaus Stark, Solmaz Assa, Peter S. Braund, Claudia Cabrera, Anna F. Dominiczak, Martin Gögele, Leanne M. Hall, M. Arfan Ikram, Maryam Kavousi, Karl J. Lackner, Christian Müller, Thomas Münzel, Matthias Nauck, Sandosh Padmanabhan, Norbert Pfeiffer, Tim D. Spector, Andre G. Uitterlinden, Niek Verweij, Uwe Völker, Helen R. Warren, Mobeen Zafar, Stephan B. Felix, Jan A. Kors, Harold Snieder, Patricia B. Munroe, Cristian Pattaro, Christian Fuchsberger, Georg Schmidt, Ilja M. Nolte, Heribert Schunkert, Peter Pramstaller, Philipp S. Wild, Pim van der Harst, Bruno H. Stricker, Renate B. Schnabel, Nilesh J. Samani, Christian Hengstenberg, Marcus Dörr, Elijah R. Behr, Wibke Reinhard
Abstract
High levels of circulating miR-16 in the serum of multiple myeloma (MM) patients are independently associated with longer survival. Although the tumor suppressor function of intracellular miR-16 in cancer cells, including MM plasma cells (PCs), has been highly elucidated, its extracellular role in maintaining a non-supportive cancer microenvironment has not been fully explored. Here, we show that miR-16 can be actively secreted by MM cells through extracellular vesicles (EVs), and its extracellular and intracellular levels are directly correlated. We also show that EVs isolated from MM patients and from the conditioned media of MM-PCs can differentiate circulating monocytes to M2-tumor supportive macrophages (TAMs) and that the presence of higher levels of extracellular miR-16 counteracts this effect. In agreement with these observations, our data show that miR-16 directly targets the IKKα/β complex of the NF-kB canonical pathway, which is known to play a critical role in polarizing macrophages toward an M2 phenotype. By using a miR-15a-16-1 knockout mouse model, we also show that loss of the miR-16 cluster supports polarization to M2-macrophages. Finally, we demonstrate the therapeutic benefit of miR-16 overexpression in potentiating the anti-MM activity by a proteasome inhibitor in the presence of MM resident bone marrow TAM.
Authors
Jihane Khalife, Jayeeta Ghose, Marianna Martella, Domenico Viola, Alberto Rocci, Estelle Troadec, Cesar Terrazas, Abhay R. Satoskar, Emine Gulsen Gunes, Ada Dona, James F. Sanchez, P. Leif Bergsagel, Marta Chesi, Alex Pozhitkov, Steven Rosen, Guido Marcucci, Jonathan J. Keats, Craig C. Hofmeister, Amrita Krishnan, Enrico Caserta, Flavia Pichiorri
