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Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.151892.
Abstract
Monocyte-derived macrophages are key players in tissue homeostasis and diseases regulated by a variety of signaling molecules. Recent literature has highlighted the ability for biogenic amines to regulate macrophage functions, but the mechanisms governing biogenic amine signaling in and around immune cells remains nebulous. In the central nervous system (CNS), biogenic amine transporters are regarded as the master regulators of neurotransmitter signaling. While we and others have shown that macrophages express these transporters, relatively little is known of their function in these cells. To address these knowledge gaps, we investigated the function of norepinephrine (NET) and dopamine (DAT) transporters on human monocyte-derived macrophages. We found that both NET and DAT are present and can uptake substrate from the extracellular space at baseline. Not only was DAT expressed in cultured monocyte-derived macrophages (MDMs), but it was also detected in a subset of intestinal macrophages in situ. Surprisingly, we discovered a NET-independent, DAT-mediated immuno-modulatory mechanism in response to lipopolysaccharide (LPS). LPS induced reverse transport of dopamine through DAT, engaging an autocrine/paracrine signaling loop that regulated the macrophage response. Removing this signaling loop enhanced the pro-inflammatory response to LPS. Collectively, our data introduce a potential role for DAT in the regulation of innate immunity.
Authors
Phillip M. Mackie, Adithya Gopinath, Dominic M. Montas, Alyssa Nielsen, Aidan Smith, Rachel A. Nolan, Kaitlyn Runner, Stephanie M. Matt, John McNamee, Joshua E. Riklan, Kengo Adachi, Andria Doty, Adolfo Ramirez-Zamora, Long Yan, Peter J. Gaskill, Wolfgang J. Streit, Michael S. Okun, Habibeh Khoshbouei
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.150894.
Abstract
Sustained proliferative signaling and resisting cell death are hallmarks of cancer. Zinc finger protein 277 (ZNF277; murine Zfp277), a transcription factor regulating cellular senescence, is overexpressed in colon cancer but its actions in intestinal homeostasis and neoplasia are unclear. Using human and murine intestine, human colon cancer cells, and ApcMin/+ mice with dysregulated β-catenin signaling and exuberant intestinal neoplasia, we explored the actions of ZNF/Zfp277 and defined the underlying mechanisms. In normal human and murine intestine, ZNF/Zfp277 was expressed uniquely in early stem cell progenitors, undifferentiated transit-amplifying cells (TACs). Zfp277 was overexpressed in the ApcMin/+ mouse colon, implicating ZNF/Zfp277 as a transcriptional target of β-catenin signaling. We confirmed this by showing β-catenin knockdown reduced ZNF277 expression and, using chromatin immunoprecipitation, identified two β-catenin binding sites in the ZNF277 promoter. Zfp277 deficiency attenuated intestinal epithelial cell proliferation and tumor formation, and strikingly prolonged ApcMin/+ mouse survival. RNA-Seq and PCR analyses revealed Zfp277 modulates expression of genes in key cancer pathways including β-catenin signaling, the HOXD family that regulates development, and p21WAF1, a cell cycle inhibitor and tumor suppressor. In both human colon cancer cells and the murine colon, ZNF/Zfp277 deficiency induced p21WAF1 expression and promoted senescence. Our findings identify ZNF/Zfp277 as both a TAC marker and colon cancer oncogene that regulates cellular proliferation and senescence, in part by repressing p21WAF1 expression.
Authors
Guofeng Xie, Zhongsheng Peng, Jinqing Liang, Shannon M. Larabee, Cinthia B. Drachenberg, Harris Yfantis, Jean-Pierre Raufman
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.155747.
Abstract
Myocardial infarction causes pathological changes in the autonomic nervous system, which exacerbate heart failure and predispose to fatal ventricular arrhythmias and sudden death. These changes are characterized by sympathetic activation and parasympathetic dysfunction (reduced vagal tone). Reasons for the central vagal withdrawal and, specifically, whether myocardial infarction causes changes in cardiac vagal afferent neurotransmission that then affect efferent tone, remain unknown. The objective of this study was to evaluate whether myocardial infarction causes changes in vagal neuronal afferent signaling. Using in-vivo neural recordings from the inferior vagal (nodose) ganglia and immunohistochemical analyses, structural and functional alterations in vagal sensory neurons were characterized in a chronic porcine infarct model and compared with normal animals. Myocardial infarction caused an increase in the number of nociceptive neurons, but a paradoxical decrease in functional nociceptive signaling. No changes in mechanosensitive neurons were observed. Notably, nociceptive neurons demonstrated an increase in GABAergic expression. Given that nociceptive signaling through the vagal ganglia increases efferent vagal tone, the results of this study suggest that a decrease in functional nociception, possibly due to an increase in expression of inhibitory neurotransmitters, may contribute to vagal withdrawal after myocardial infarction.
Authors
Siamak Salavatian, Jonathan D. Hoang, Naoko Yamaguchi, Zulfiqar A. Lokhandwala, Mohammed Amer Swid, J. Andrew Armour, Jeffrey L. Ardell, Marmar Vaseghi
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.150041.
Abstract
Mitophagy and mitochondrial integrated stress response (ISR) are two primary protective mechanisms to maintain functional mitochondria. Whether these two processes are coordinately regulated remains unclear. Here we show that mitochondrial fission 1 protein (Fis1), which is required for completion of mitophagy, serves as a signaling hub linking mitophagy and ISR. In mouse hepatocytes, high fat diet (HFD) feeding induces unresolved oxidative stress, defective mitophagy and enhanced type I interferon (IFN-I) response implicated in promoting metabolic inflammation. Adenoviral-mediated acute hepatic Fis1 over-expression is sufficient to reduce oxidative damage and improve glucose homeostasis in HFD fed mice. RNA-seq analysis reveals that Fis1 triggers a retrograde mitochondria-to-nucleus communication upregulating ISR genes encoding anti-oxidant defense, redox homeostasis and proteostasis pathways. Fis1-mediated ISR also suppresses expression of IFN-I stimulated genes through Atf5, which inhibits the transactivation activity of Irf3 known to control IFN-I production. Metabolite analysis demonstrates that Fis1 activation leads to accumulation of fumarate, a TCA cycle intermediate capable of increasing Atf5 activity. Consequently, hepatic Atf5 over-expression or monomethyl fumarate (MMF) treatment improves glucose homeostasis in HFD fed mice. Collectively, these results support the potential use of small molecules targeting the Fis1-Atf5 axis, such as MMF, to treat metabolic diseases.
Authors
Yae-Huei Liou, Jean Personnaz, David Jacobi, Nelson H. Knudsen, Mayer M. Chalom, Kyle A. Starost, Israel C. Nnah, Chih-Hao Lee
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.152800.
Abstract
Type 1 diabetes is an autoimmune disease characterized by insulin-producing beta-cell destruction. While islet transplantation restores euglycemia and improves patient outcomes, an ideal transplant site remains elusive. Brown adipose tissue (BAT) is a highly vascularized and anti-inflammatory microenvironment. As these tissue features can promote islet graft survival, we hypothesize that islets transplanted into BAT will maintain islet graft and BAT function, while delaying immune-mediated rejection. We performed syngeneic and allogeneic islet transplants into BAT or under the kidney capsule of streptozotocin (STZ)-induced diabetic NOD.Rag and NOD mice to investigate islet graft function, BAT function, metabolism, and immune-mediated rejection. Islet grafts within BAT restored euglycemia similarly to kidney capsule controls. Islets transplanted in BAT maintained expression of islet hormones, transcription factors, and were vascularized. Compared to kidney capsule and euglycemic mock surgery controls, no differences in glucose or insulin tolerance, thermogenic regulation, or energy expenditure were observed with islet grafts in BAT. Immune profiling of BAT revealed enriched anti-inflammatory macrophages and T cells. Compared to kidney capsule, islets transplanted in BAT demonstrated significant delays in autoimmune and allograft rejection, possibly due to increased anti-inflammatory immune populations. Our data support BAT as an alternative islet transplantation site that may improve graft survival.
Authors
Jessica D. Kepple, Jessie M. Barra, Martin E. Young, Chad S. Hunter, Hubert M. Tse
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.156928.
Abstract
Capillary malformation-arteriovenous malformation (CM-AVM) is a blood vascular anomaly caused by inherited loss of function mutations in RASA1 or EPHB4 genes that encode p120 Ras GTPase-activating protein (p120 RasGAP/RASA1) and Ephrin receptor B4 (EPHB4) respectively. However, whether RASA1 and EPHB4 function in the same molecular signaling pathway to regulate the blood vasculature is uncertain. Here, we show that induced endothelial cell (EC)-specific disruption of Ephb4 in mice results in accumulation of collagen IV in the EC endoplasmic reticulum leading to EC apoptotic death and defective developmental, neonatal and pathological angiogenesis, as reported previously in induced EC-specific RASA1-deficient mice. Moreover, defects in angiogenic responses in EPHB4-deficient mice can be rescued by drugs that inhibit signaling through the Ras pathway and drugs that promote collagen IV export from the ER. However, EPHB4 mutant mice that express a form of EPHB4 that is unable to physically engage RASA1 but retains protein tyrosine kinase activity show normal angiogenic responses. These findings provide strong evidence that RASA1 and EPHB4 function in the same signaling pathway to protect against the development of CM-AVM independent of physical interaction and have important implications with regards possible means of treatment of this disease.
Authors
Di Chen, Elizabeth D. Hughes, Thomas L. Saunders, Jiangping Wu, Magda N. Hernández Vásquez, Taija Makinen, Philip D. King
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.143018.
Abstract
The G-protein coupled C-X-C chemokine receptor 4 (CXCR4) is a candidate therapeutic target for tissue fibrosis. A novel fully human single-domain antibody-like scaffold i-body AD-114-PA600 (AD-114) with specific high binding affinity to CXCR4 has been developed. To define the renoprotective role, AD-114 was administrated in a mouse model of renal fibrosis induced by folic acid (FA). Increased extracellular matrix (ECM) accumulation, macrophage infiltration, inflammatory response, transforming growth factor beta-1 (TGF-β1) expression and fibroblasts activation were observed in kidneys of mice with FA-induced nephropathy. These markers were normalized or partially reversed by AD-114 treatment. In vitro studies demonstrated AD-114 blocked TGF-β1-induced upregulated expression of ECM, matrix metallopeptidase-2 (MMP-2) and downstream p38 mitogen-activated protein kinases (p38 MAPK) and Phosphoinositide 3-kinases (PI3K)/AKT/ mammalian target of rapamycin (mTOR) signaling pathways in a renal proximal tubular cell line. Additionally, these renoprotective effects were validated in a second model of unilateral ureteral obstruction (UUO) using a second generation of AD-114 (Fc-fused AD-114, also named AD-214). Collectively, these results suggest a renoprotective role of AD-114 as it inhibited the chemotactic function of CXCR4 as well as blocked CXCR4 downstream p38 MAPK and PI3K/AKT/mTOR signaling, which establish a therapeutic strategy for AD-114 targeting CXCR4 to limit renal fibrosis.
Authors
Qinghua Cao, Chunling Huang, Hao Yi, Anthony J. Gill, Angela Chou, Michael Foley, Chris G. Hosking, Kevin K. Lim, Cristina F. Triffon, Ying Shi, Xin-Ming Chen, Carol A. Pollock
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.146563.
Abstract
Increased adipose tissue macrophages (ATM) correlate with metabolic dysfunction in humans and are causal in development of insulin resistance in mice. Recent bulk and single cell transcriptomics studies reveal a wide spectrum of gene expression signatures possible for macrophages that depends on context, but the signatures of human ATM subtypes are not well defined in obesity and diabetes. We profiled three prominent ATM subtypes from human adipose tissue in obesity and determined their relationship to type 2 diabetes. Visceral (VAT) and subcutaneous (SAT) adipose tissue samples were collected from diabetic and non-diabetic obese subjects to evaluate cellular content and gene expression. VAT CD206+CD11c− ATMs were increased in diabetic subjects, scavenger receptor-rich with low intracellular lipids, secreted proinflammatory cytokines, and diverged significantly from two CD11c+ ATM subtypes, which were lipid-laden, lipid antigen presenting, and overlapped with monocyte signatures. Furthermore, diabetic VAT was enriched for CD206+CD11c− ATM and inflammatory signatures, scavenger receptors, and MHC II antigen presentation genes. VAT immunostaining found CD206+CD11c− ATMs concentrated in vascularized lymphoid clusters adjacent to CD206−CD11c+ ATMs, while CD206+CD11c+ were distributed between adipocytes. Our results suggest ATM subtype-specific profiles that uniquely contribute to the phenotypic variation in obesity.
Authors
Lindsey A. Muir, Kae Won Cho, Lynn M. Geletka, Nicki A. Baker, Carmen G. Flesher, Anne P. Ehlers, Niko Kaciroti, Stephen Lindsly, Scott Ronquist, Indika Rajapakse, Robert W. O’Rourke, Carey N. Lumeng
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.151893.
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmia syndrome due to gene mutations that render RYR2 calcium release channels hyperactive, causing spontaneous calcium release and delayed afterdepolarizations (DADs). What remains unknown is the cellular source of ventricular arrhythmia triggered by DADs – Purkinje cells in the conduction system or ventricular cardiomyocytes in the working myocardium. To answer this question, we used a genetic approach in mice to knock out cardiac calsequestrin either in Purkinje cells or in ventricular cardiomyocytes. Total loss of calsequestrin in the heart causes a severe CPVT phenotype in mice and humans. We found that loss of calsequestrin only in ventricular myocytes produced a full-blown CPVT phenotype, whereas mice with loss of calsequestrin only in Purkinje cells were comparable to wild-type mice. Subendocardial chemical ablation or restoration of calsequestrin expression in subendocardial cardiomyocytes neighboring Purkinje cells was sufficient to protect against catecholamine-induced arrhythmias. In silico modeling demonstrated that DADs in ventricular myocardium can trigger full action potentials in the Purkinje fiber, but not vice versa. Hence, ectopic beats in CPVT are likely generated at the Purkinje-myocardial junction via a heretofore unrecognized tissue mechanism, whereby DADs in the ventricular myocardium trigger full action potentials in adjacent Purkinje cells.
Authors
Daniel J. Blackwell, Michela Faggioni, Matthew J. Wleklinski, Nieves Gomez-Hurtado, Raghav Venkataraman, Chelsea E. Gibbs, Franz J. Baudenbacher, Shiaoching Gong, Glenn I. Fishman, Patrick M. Boyle, Karl Pfeifer, Bjorn C. Knollmann
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.155655.
Abstract
BACKGROUND. Adenoviral (Ad)-vectored vaccines are typically administered via intramuscular injection to humans, incapable of inducing respiratory mucosal immunity. However, aerosol delivery of Ad-vectored vaccines remains poorly characterized and its ability to induce mucosal immunity in humans is unknown. This phase 1b trial was to evaluate the safety and immunogenicity of human serotype-5 Ad-vectored tuberculosis (TB) vaccine (AdHu5Ag85A) delivered to humans via inhaled aerosol or intramuscular injection. METHODS. 31 healthy, previously BCG-vaccinated adults were enrolled. AdHu5Ag85A was administered by single-dose aerosol using Aeroneb® Solo Nebulizer or by intramuscular (IM) injection. The study consisted of the low dose (LD) aerosol, high dose (HD) aerosol and IM groups. The adverse events were assessed at various times post-vaccination. Immunogenicity data were collected from the peripheral blood and bronchoalveolar lavage samples at baseline and select timepoints post-vaccination. RESULTS. The nebulized aerosol droplets were <5.39µm in size. Both LD and HD of AdHu5Ag85A administered by aerosol inhalation and IM injection were safe and well-tolerated. Both aerosol doses, particularly LD, but not IM, vaccination markedly induced airway tissue-resident memory CD4 and CD8 T cells of polyfunctionality. While as expected, IM vaccination induced Ag85A-specific T cell responses in the blood, the LD aerosol vaccination also elicited such T cells in the blood. Furthermore, the LD aerosol vaccination induced persisting transcriptional changes in alveolar macrophages. CONCLUSIONS. Inhaled aerosol delivery of Ad-vectored vaccine is a safe and superior way to elicit respiratory mucosal immunity. This study warrants further development of aerosol vaccine strategies against respiratory pathogens including TB and COVID-19. TRIAL REGISTRATION. This trial is registered with ClinicalTrial.gov, NCT# 02337270. FUNDING. The Canadian Institutes for Health Research and the Natural Sciences and Engineering Research Council of Canada.
Authors
Mangalakumari Jeyanathan, Dominik K. Fritz, Sam Afkhami, Emilio Aguirre, Karen J. Howie, Anna Zganiacz, Anna Dvorkin-Gheva, Michael R. Thompson, Richard Silver, Ruth P. Cusack, Brian D. Lichty, Paul M. O'Byrne, Martin Kolb, Maria Fe C. Medina, Myrna B. Dolovich, Imran Satia, Gail M Gauvreau, Zhou Xing, Fiona Smaill
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.149636.
Abstract
Short stature is a major skeletal phenotype in osteogenesis imperfecta (OI), a genetic disorder mainly caused by mutations in genes encoding type I collagen. However, the underlying mechanism is poorly understood and no effective treatment is available. In OI mice that carry a G610C mutation in COL1A2, we previously found that mature hypertrophic chondrocytes (HCs) are exposed to cell stress due to accumulation of misfolded mutant type I procollagen in the endoplasmic reticulum (ER). By fate mapping analysis of HCs in G610C OI mice, we found that HCs stagnate in the growth plate, inhibiting translocation of HC descendants to the trabecular area and their differentiation to osteoblasts. Treatment with 4-phenylbutyric acid (4PBA), a chemical chaperone, restored HC ER structure and rescued this inhibition, resulting in enhanced longitudinal bone growth in G610C OI mice. Interestingly, the effects of 4PBA on ER dilation were limited in osteoblasts and the bone fragility was not ameliorated. These results highlight the importance of targeting HCs to treat growth deficiency in OI. Our findings demonstrate that HC dysfunction induced by ER disruption plays a critical role in the pathogenesis of OI growth deficiency, which lays the foundation for developing new therapies for OI.
Authors
Amanda L. Scheiber, Kevin J. Wilkinson, Akiko Suzuki, Motomi Enomoto-Iwamoto, Takashi Kaito, Kathryn S.E. Cheah, Masahiro Iwamoto, Sergey Leikin, Satoru Otsuru
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.149120.
Abstract
Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Several investigators have reported that adaptive NKG2C+ NK cells persistently expand during CMV reactivation. In our study, two cohorts were enrolled to explored the relationships among the NKG2C genotype, NKG2C+ NK cell reconstitution, and CMV infection. Multivariate analysis showed that donor NKG2C gene deletion was an independent prognostic factor for CMV reactivation and refractory CMV reactivation. Furthermore, the quantitative, qualitative reconstitution and anti-CMV function of adaptive NKG2C+ NK cells after transplantation was significantly lower in patients grafted with NKG2Cwt/del donor cells than in those grafted with NKG2Cwt/wt donor cells. The quantitative reconstitution of NKG2C+ NK cells at day 30 after transplantation was significantly lower in patients with treatment-refractory CMV reactivation than in those in the no-CMV-reactivation and CMV-reactivation groups. In humanized CMV-infected mice, we found that compared with those from NKG2Cwt/del donors, adaptive NKG2C+ NK cells from NKG2Cwt/wt donors induced earlier and stronger expansion of NKG2C+ NK cells and earlier and stronger CMV clearance in vivo. In conclusion, donor NKG2C homozygosity contributes to CMV clearance by promoting the quantitative and qualitative reconstruction of adaptive NKG2C+ NK cells after haploidentical allo-HSCT.
Authors
Xing-Xing Yu, Qian-Nan Shang, Xue-Fei Liu, Mei He, Xu-Ying Pei, Xiao-Dong Mo, Meng Lv, Ting-Ting Han, Ming-Rui Huo, Xiaosu Zhao, Ying-Jun Chang, Yu Wang, Xiao-Hui Zhang, Lan-Ping Xu, Kai-Yan Liu, Xiangyu Zhao, Xiaojun Huang
Citation Information: JCI Insight. 2022. https://doi.org/10.1172/jci.insight.152690.
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease characterized by collagen deposition within the lung interstitium. Bacterial infection is associated with increased morbidity and more rapid mortality in IPF patient populations and pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) are commonly isolated from the lungs of hospitalized IPF patients. Despite this, the effects of fibrotic lung injury on critical immune responses to infection remain unknown. In the present study, we show that, like human IPF, fibrotic mice infected with MRSA exhibit increased morbidity and mortality compared to uninfected fibrotic mice. We determine that fibrosis confers a defect in MRSA clearance compared to non-fibrotic mice, resulting from blunted innate immune responses. We show that fibrosis inhibits neutrophil intracellular killing of MRSA through impaired neutrophil elastase (NE) release and oxidative radical production. Additionally, we demonstrate that lung macrophages from fibrotic mice have impaired phagocytosis of MRSA. Our study describes potentially novel impairments to antimicrobial responses upon the development of pulmonary fibrosis and our findings suggest a possible mechanism for why IPF patients are at greater risk of morbidity and mortality related to infection.
Authors
Helen I. Warheit-Niemi, Summer J. Edwards, Shuvasree SenGupta, Carole A. Parent, Xiaofeng Zhou, David N. O'Dwyer, Bethany B. Moore
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.153526.
Tissue metabolites in diffuse glioma and their modulations by IDH1 mutation, histology and treatment
Abstract
The discovery of the oncometabolite 2-hydroxyglutarate in isocitrate dehydrogenase (IDH)1-mutated tumor entities affirmed the role of metabolism in cancer. Yet, large databases with tissue metabolites that are modulated by IDH1 mutation remain an area of development. Here, we present an unprecedented and valuable resource for tissue metabolites in diffuse glioma and their modulations by IDH1 mutation, histology and tumor treatments in 101 tissue samples from 73 diffuse glioma patients (24 astrocytoma, 17 oligodendroglioma, 32 glioblastoma), investigated by NMR-based metabolomics and supported by RNA sequencing. We discovered comparison-specific metabolites and pathways modulated by IDH1 (“IDH1 mutation status cohort”) and tumor entity. The “Longitudinal investigation cohort” provides metabolic profiles of untreated and corresponding treated glioma samples at first progression. Most interestingly, univariate and multivariate cox regressions and Kaplan Meier analyses revealed that tissue metabolites correlate with progression-free and overall survival. Thus, this study introduces novel candidate prognostic and surrogate metabolite biomarkers for future prospective clinical studies aiming at further refining patient stratification in diffuse glioma. Furthermore, our data will facilitate the generation of so far unanticipated hypotheses for experimental studies to advance our molecular understanding of glioma biology.
Authors
Christoph Trautwein, Laimdota Zizmare, Irina Mäurer, Benjamin Bender, Björn Bayer, Ulrike Ernemann, Marcos Tatagiba, Stefan J. Grau, Bernd J. Pichler, Marco Skardelly, Ghazaleh Tabatabai
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.150887.
Abstract
Discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase activated by collagen, contributes to chronic kidney disease (CKD). However, its role in acute kidney injury (AKI) and subsequent development of kidney fibrosis is not clear. Thus, we performed a model of severe ischemia-reperfusion-induced AKI that progresses to kidney fibrosis in wild-type and Ddr1-null mice. We show that Ddr1-null mice had reduced acute tubular injury, inflammation, and tubulointerstitial fibrosis with overall decreased renal monocyte chemoattractant protein (MCP-1) levels and STAT3 activation. We identified breakpoint cluster region (BCR) protein as a phosphorylated target of DDR1 that controls MCP-1 production in renal proximal tubule epithelial cells. DDR1-induced BCR phosphorylation or BCR downregulation increased MCP-1 secretion, suggesting that BCR negatively regulates the levels of MCP-1. Mechanistically, phosphorylation or downregulation of BCR increases β-catenin activity and in turn MCP-1 production. Finally, we show that DDR1-mediated STAT3 activation is required to stimulate the secretion of TGF-β. Thus, DDR1 contributes to acute and chronic kidney injury by regulating BCR and STAT3 phosphorylation and in turn the production of MCP-1 and TGF-β. These findings identify DDR1 an attractive therapeutic target for ameliorating both pro-inflammatory and pro-fibrotic signaling in kidney disease.
Authors
Corina M. Borza, Gema Bolas, Fabian Bock, Xiuqi Zhang, Favour C. Akabogu, Ming-Zhi Zhang, Mark de Caestecker, Min Yang, Hai-chun Yang, Ethan Lee, Leslie Gewin, Agnes B. Fogo, W. Hayes McDonald, Roy Zent, Ambra Pozzi
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.154402.
Abstract
Standard radiation (RT) therapy does not reliably provide locoregional control for women with multi-node positive and triple-negative (TNBC) breast cancers. We hypothesized that CDK4/6 inhibition (CDK4/6i) would increase the radiosensitivity not only of estrogen receptor positive (ER+) cells, but also TNBC that express retinoblastoma (RB) protein. We found that CDK4/6i radiosensitized RB wild-type TNBC (n=4, rER 1.49 – 2.22), but failed to radiosensitize RB-null TNBC (n=3, rER: 0.84 – 1.00). RB expression predicted response to CDK4/6i + RT (R2=0.84), and radiosensitization was lost in ER+/TNBC cells (rER: 0.88 – 1.13) after RB1 knockdown in isogenic and non-isogenic models. CDK4/6i suppressed homologous recombination (HR) in RB wild-type cells, but not in RB-null cells or isogenic models of RB1 loss; HR competency was rescued with RB re-expression. Radiosensitization was independent of non-homologous end joining and the known effects of CDK4/6i on cell cycle arrest. Mechanistically, RB and RAD51 interact in vitro to promote HR repair. CDK4/6i produced RB-dependent radiosensitization in TNBC xenografts, but not in isogenic RB1-null xenografts. Our data provide the preclinical rationale for a clinical trial expanding the use of CDK4/6i + RT to difficult to control RB-intact breast cancers (including TNBC) and nominate RB status as a predictive biomarker of therapeutic efficacy.
Authors
Andrea M. Pesch, Nicole H. Hirsh, Anna R. Michmerhuizen, Kassidy M. Jungles, Kari Wilder-Romans, Benjamin C. Chandler, Meilan Liu, Lynn M. Lerner, Charles A. Nino, Connor Ward, Erin F. Cobain, Theodore S. Lawrence, Lori J. Pierce, James M. Rae, Corey W. Speers
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.150330.
Abstract
Pancreatic ductal adenocarcinoma (PDA) is an extremely metastatic and lethal disease. Here in both murine and human PDA we demonstrate that extracellular matrix architecture regulates cell extrusion and subsequent invasion from intact ductal structures through Tumor-Associated Collagen Signatures (TACS). This results in early dissemination from histologically pre-malignant lesions and continual invasion from well-differentiated disease, and suggests TACS as a biomarker to aid in the pathologic assessment of early disease. Furthermore, we show that pancreatitis results in invasion-conducive architectures, thus priming the stroma prior to malignant disease. Analysis in novel microfluidics-derived microtissues and in vivo demonstrates decreased extrusion and invasion following focal adhesion kinase (FAK) inhibition, consistent with decreased metastasis. Thus, data suggest that targeting FAK or strategies to re-engineer and normalize tumor microenvironments, may have a role not only in also in very early disease but also for limiting continued dissemination from unresectable disease. Likewise, it may be beneficial to employ stroma targeting strategies to resolve precursor diseases such as pancreatitis in order to remove stromal architectures that increase risk for early dissemination.
Authors
Arja Ray, Mackenzie K. Callaway, Nelson J. Rodríguez-Merced, Alexandra L. Crampton, Marjorie Carlson, Kenneth B. Emme, Ethan A. Ensminger, Alexander A. Kinne, Jonathan H. Schrope, Haley R. Rasmussen, Hong Jiang, David G. DeNardo, David K. Wood, Paolo P. Provenzano
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.145653.
Abstract
Exchange proteins directly activated by cAMP (Epacs) are abundantly expressed in the renal tubules. We used genetic and pharmacological tools in combination with balance, electrophysiological and biochemical approaches to examine the role of Epac1 and Epac2 in renal sodium handling. We demonstrate that Epac1-/- and Epac2-/- mice exhibit a delayed anti-natriuresis to dietary sodium restriction despite augmented aldosterone levels. This was associated with a significantly lower response to the epithelial Na+ channel (ENaC) blocker amiloride, reduced ENaC activity in split-opened collecting ducts, and defective posttranslational processing of α and γENaC subunits in the knockout mice fed with Na+ deficient diet. Concomitant deletion of both isoforms led to a marginally greater natriuresis but further increased aldosterone levels. Epac2 blocker, ESI-05 and Epac1&2 blocker, ESI-09 decreased ENaC activity in EpacWT mice kept on Na+ deficient diet but not on the regular diet. ESI-09 injections led to natriuresis in EpacWT mice on Na+ deficient diet, which was caused by ENaC inhibition. In summary, our results demonstrate non-redundant actions of Epac1 and Epac2 in stimulation of ENaC activity during variations in dietary salt intake. We speculate that inhibition of Epac signaling could be instrumental in treatment of hypertensive states associated with ENaC over-activation.
Authors
Victor N. Tomilin, Kyrylo Pyrshev, Anna Stavniichuk, Naghmeh Hassanzadeh Khayyat, Guohui Ren, Oleg Zaika, Sherif Khedr, Alexander Staruschenko, Fang C. Mei, Xiaodong Cheng, Oleh Pochynyuk
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.155234.
Abstract
Systemic hypoxia is characterized by peripheral vasodilation and pulmonary vasoconstriction. However, the system-wide mechanism for signaling hypoxia remains unknown. Accumulating evidence suggests that hemoglobin in RBCs may serve as an O2 sensor and O2-responsive NO signal transducer to regulate systemic and pulmonary vascular tone, but this remains unexamined at the integrated system level. One residue invariant in mammalian hemoglobins (Hb), β-globin Cys93 (βCys93), carries NO as vasorelaxant S-nitrosothiol (SNO) to autoregulate blood flow during oxygen delivery. βCys93Ala mutant mice thus exhibit systemic hypoxia despite transporting oxygen normally. Here we show that βCys93Ala mutant mice have reduced S-nitrosohemoglobin (SNO-Hb) at baseline and upon targeted SNO repletion, and that hypoxic vasodilation by RBCs is impaired in vitro and in vivo, recapitulating hypoxic pathophysiology. Notably, βCys93Ala mutant mice show marked impairment of hypoxic peripheral vasodilation and develop signs of pulmonary hypertension with age. Mutant mice also die prematurely with cor pulmonale (pulmonary hypertension with right ventricular dysfunction) when living under low oxygen. Altogether, we identify a major role for RBC-SNO in clinically-relevant vasodilatory responses attributed previously to endothelial NO. We conclude that SNO-Hb transduces the integrated, system-wide response to hypoxia in the mammalian respiratory cycle, expanding a core physiological principle.
Authors
Rongli Zhang, Alfred Hausladen, Zhaoxia Qian, Xudong Liao, Richard T. Premont, Jonathan S. Stamler
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.153191.
Abstract
Ca2+/calmodulin-stimulated group Ⅰ adenylyl cyclase (AC) isoforms AC1 and AC8 have been involved in nociceptive processing and morphine responses. However, whether AC3, another member of group I ACs, is involved in nociceptive transmission and regulates opioid receptor signaling remain elusive. Here we report that conditional knockout of AC3 (AC3CKO) in L3 and L4 DRGs robustly facilitates the mouse nociceptive responses, decreases voltage-gated potassium (Kv) channel currents and increases neuronal excitability. Also, AC3CKO eliminates the analgesic effect of κ opioid receptor (KOR) agonist and its inhibition on Kv channel by classical Gαi/o signaling or nonclassical direct interaction of KOR and AC3 proteins. Interestingly, significantly upregulated AC1 level and cAMP concentration are detected in AC3 deficient DRGs. Inhibition of AC1 completely reversed cAMP upregulation, neuronal excitability enhancement and nociceptive behavioral hypersensitivity in AC3CKO mice. Our findings suggest a crucial role of peripheral AC3 in nociceptive modulation and KOR opioid analgesia.
Authors
Wen-Wen Zhang, Hong Cao, Yang Li, Xian-Jun Fu, Yu-Qiu Zhang
