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Abstract
BACKGROUND. Assessment of risk for chronic kidney disease (CKD) after acute kidney injury (AKI) is based on a limited set of markers primarily reflecting glomerular function. We evaluated markers of cell integrity (EGF) and inflammation (monocyte chemoattractant protein-1 [MCP-1]) for predicting long-term kidney outcomes after cardiac surgery. METHODS. We measured the urinary biomarkers EGF and MCP-1 in pre- and post-operative urine samples from 865 adult patients who underwent cardiac surgery from 2007–2010 at 2 sites in Canada and the United States and assessed their associations with the composite outcome of CKD incidence or progression. We also used single-cell (Sc) RNAseq of biopsies from patients with AKI to perform a transcriptomic analysis of programs that are coregulated with the genes encoding the 2 biomarkers. RESULTS. Over a median (IQR) follow-up of 5.8 (4.2-7.1) years, 266 (30.8%) patients developed the composite CKD outcome. Post-operatively, higher levels of urinary EGF were protective and higher levels of MCP-1 were associated with the composite CKD outcome (adjusted HR 0.83, 95% CI 0.73-0.95 and 1.10, 95% CI 1.00-1.21, respectively). Intrarenal scRNAseq transcriptomes in patients with AKI-defined cell populations revealed concordant changes in EGF and MCP-1 levels and identified underlying molecular processes associated with loss of EGF expression and gain of CCL2 (encoding MCP-1) expression. CONCLUSION. Urinary EGF and MCP-1 were each independently associated with CKD incidence or progression after cardiac surgery. These markers may serve as noninvasive indicators of tubular damage, supported by tissue transcriptomes and provide opportunity for novel interventions in cardiac surgery. TRIAL REGISTRATION. ClinicalTrials.gov NCT00774137 FUNDING. NIH (R01HL085757 to CRP) funded the TRIBE-AKI Consortium.
Authors
Steven Menez, Wenjun Ju, Rajasree Menon, Dennis G. Moledina, Heather Thiessen Philbrook, Eric McArthur, Yaqi Jia, Wassim Obeid, Sherry G. Mansour, Jay K. Koyner, Michael G. Shlipak, Steven G. Coca, Amit X. Garg, John A. Kellum, Andrew S Bomback, Matthias Kretzler, Chirag R. Parikh
Abstract
Right ventricular (RV) fibrosis is a key feature of maladaptive RV hypertrophy and dysfunction and is associated with poor outcomes in pulmonary hypertension (PH). However, mechanisms and therapeutic strategies to mitigate RV fibrosis remain unrealized. Previously, we identified that cardiac fibroblast α7 nicotinic acetylcholine receptor (α7 nAChR) drives smoking induced RV fibrosis. Here we sought to define the role of α7 nAChR in RV dysfunction and fibrosis in the settings of RV pressure overload as seen in PH. We show that RV tissue from PH patients has increased collagen content and ACh expression. Using experimental rat model of PH, we demonstrate that RV fibrosis and dysfunction are associated with increases in ACh and α7 nAChR expression in the RV but not in the LV. In vitro studies show that α7 nAChR activation leads to an increase in adult ventricular fibroblast proliferation and collagen content mediated by a Ca2+/ epidermal growth factor receptor (EGFR) signaling mechanism. Pharmacological antagonism of nAChR decreases RV collagen content and improves RV function in the PH model. Further, mice lacking α7 nAChR exhibit improved RV diastolic function and have lower RV collagen content in response to persistently increased RV afterload, compared to wild-type controls. These finding indicate that enhanced α7 nAChR signaling is an important mechanism underlying RV fibrosis and dysfunction, and targeted inhibition of α7 nAChR is a novel therapeutic strategy in the setting of increased RV afterload.
Authors
Alexander Vang, Denielli da Silva Gonçalves Bos, Ana Fernandez-Nicolas, Peng Zhang, Alan R. Morrison, Thomas J. Mancini, Richard T. Clements, Iuliia Polina, Michael W. Cypress, Bong Sook Jhun, Edward Hawrot, Ulrike Mende, Jin O-Uchi, Gaurav Choudhary
Abstract
Adipocytes were long considered to be inert components of the bone marrow niche, but both mouse and human models suggest that bone marrow adipose tissue (BMAT) is dynamic and responsive to hormonal and nutrient cues. In this study of healthy volunteers, we investigated how BMAT responds to acute nutrient changes, including analyses of endocrine determinants and paracrine factors from marrow aspirates. Study participants underwent a 10-day high-calorie protocol followed by a 10-day fast. We demonstrate three novel findings: 1) vertebral BMAT increased significantly during both high-calorie feeding and fasting, suggesting that BMAT may have different functions in states of caloric excess compared to caloric deprivation; 2) Ghrelin, which decreased in response to both high-calorie feeding and fasting, was inversely associated with changes in BMAT; 3) In response to high-calorie feeding, resistin levels in the marrow sera, but not the circulation, rose significantly. In addition, TNF-a expression in marrow adipocytes increased with high-calorie feeding and decreased upon fasting. Therefore, high-calorie feeding, but not fasting, induces an immune response in the bone marrow similar to what has been reported in peripheral adipose tissue. Understanding the immunomodulatory regulators in the marrow may provide further insight into the homeostatic function of this unique adipose tissue depot.
Authors
Pouneh K. Fazeli, Miriam A. Bredella, Olga Gisela Pachon-Peña, Wenxiu Zhao, Xun Zhang, Alexander T. Faje, Megi Resulaj, Sai P. Polineni, Tara M. Holmes, Hang Lee, Elizabeth K. O’Donnell, Ormond A. MacDougald, Mark C. Horowitz, Clifford J. Rosen, Anne Klibanski
Abstract
BACKGROUND. Continued androgen receptor (AR) signaling constitutes a key target for treatment in metastatic castration-resistant prostate cancer (CRPC). Studies have identified 11-ketotestosterone (11KT) as a potent AR agonist, but it is unknown if 11KT is present at physiologically-relevant concentrations in CRPC patients to drive AR activation. The goal of this study was to investigate the circulating steroid metabolome including all active androgens in CRPC patients. METHODS. Metastatic CRPC patients (n=29) starting a new line of systemic therapy were included. Sequential plasma samples were obtained for measurement of circulating steroid concentrations by multi-steroid profiling employing liquid chromatography-tandem mass spectrometry. Metastatic tumor biopsy samples were obtained at baseline and subjected to RNA sequencing. RESULTS. 11KT was the most abundant circulating active androgen in 97% of CRPC patients (median 0.39 nmol/L, range: 0.03–2.39 nmol/L), constituting 60% (IQR 43-79%) of the total active androgen (TA) pool. Treatment with glucocorticoids reduced 11KT by 84% (49-89%) and testosterone (T) by 68% (38-79%). Circulating TA concentrations at baseline were associated with a distinct intratumoral gene expression signature comprising AR-regulated genes. CONCLUSIONS. The potent AR agonist 11KT is the predominant circulating active androgen in CRPC patients and, therefore, one of the potential drivers of AR activation in CRPC. Assessment of androgen status should be extended to include 11KT, as current clinical approaches likely underestimate androgen abundance in CRPC patients. Trial registrationNetherlands TRIAL REGISTRATION. NL5625(NTR5732) FUNDING. Daniel den Hoed foundation (Hofland) and Wellcome Trust (Investigator Award WT209492/Z/17/Z, Arlt)
Authors
Gido Snaterse, Lisanne F. van Dessel, Job van Riet, Angela E. Taylor, Michelle van der Vlugt-Daane, Paul Hamberg, Ronald de Wit, Jenny A. Visser, Wiebke Arlt, Martijn P. Lolkema, Johannes Hofland
Abstract
The hypothalamus is a critical regulator of glucose metabolism and is capable of correcting diabetes conditions independently of an effect on energy balance. The small GTPase Rap1 in the forebrain is implicated in high-fat diet (HFD)-induced obesity and glucose imbalance. Here, we report that increasing Rap1 activity selectively in the medial hypothalamus elevated blood glucose without increasing the body weight of HFD-fed mice. In contrast, decreasing hypothalamic Rap1 activity protected mice from diet-induced hyperglycemia but did not prevent weight gain. The remarkable glycemic effect of Rap1 was reproduced when Rap1 was specifically deleted in SF1-positive neurons in the ventromedial hypothalamic nucleus (VMH) known to regulate glucose metabolism. While having no effect on body weight regardless of sex, diet, and age, Rap1 deficiency in the VMH SF1 neurons markedly lowered blood glucose and insulin levels, improved glucose and insulin tolerance, and protected mice against HFD-induced neural leptin resistance and peripheral insulin resistance at the cellular and whole-body levels. Lastly, acute pharmacological inhibition of brain Epac2, a direct activator of Rap1, corrected glucose imbalance in obese mouse models. Our findings uncover the primary role of VMH Rap1 in glycemic control and implicate Rap1 signaling as a potential target for therapeutic intervention in diabetes.
Authors
Kentaro Kaneko, Hsiao-Yun Lin, Yukiko Fu, Pradip K. Saha, Ana B. De la Puente-Gomez, Yong Xu, Kousaku Ohinata, Peter Chen, Alexei Morozov, Makoto Fukuda
Abstract
Mice are normally unaffected by SARS-CoV-2 infection since the virus does not bind effectively to the murine version of the ACE2 receptor molecule. Here we report that induced mild pulmonary morbidities render SARS-CoV-2 refractive CD-1 mice to be susceptible to this virus. Specifically, SARS-CoV-2 infection after application of low-doses of the acute-lung-injury stimulants bleomycin or ricin caused a severe disease in CD-1 mice, manifested by sustained body weight loss and mortality rates of >50%. Further studies revealed markedly higher levels of viral RNA in the lungs, heart and serum of low-dose-ricin pretreated, as compared to non-pretreated mice. Furthermore, lung extracts prepared 2-3 days after viral infection contained subgenomic RNA and virus particles capable of replication, only when derived from the pretreated mice. The deleterious effects of SARS-CoV-2 infection were effectively alleviated by passive transfer of polyclonal or monoclonal antibodies generated against SARS-CoV-2 RBD. Thus, viral cell entry in the sensitized mice seems to depend on viral RBD binding, albeit by a mechanism other than the canonical ACE2-mediated uptake route. This unique mode of viral entry, observed over a mildly injured tissue background, may contribute to the exacerbation of COVID-19 pathologies in patients with preexisting morbidities.
Authors
Reut Falach, Liat Bar-On, Shlomi Lazar, Tamar Kadar, Ohad Mazor, Moshe Aftalion, David Gur, Yentl Evgy, Ohad Shifman, Tamar Aminov, Ofir Israeli, Inbar Cohen-Gihon, Galia Zaide, Hila Gutman, Yaron Vagima, Efi Makdasi, Dana Stein, Ronit Rosenfeld, Ron Alcalay, Eran Zahavy, Haim Levy, Itai Glinert, Amir Ben-Shmuel, Tomer Israely, Sharon Melamed, Boaz Politi, Hagit Achdout, Shmuel Yitzhaki, Chanoch Kronman, Tamar Sabo
Abstract
BACKGROUND. The chemokine system of ligands and receptors is implicated in the progression of Alcohol-associated hepatitis (AH). Finding upstream regulators could lead to novel therapies. MOTHODS. The coordinated expression of chemokines in livers of healthy controls (HC) and patients with AH in two distinct cohorts of patients with various chronic liver diseases. Studies in cultured hepatocytes and in tissue-specific knockouts were used for mechanistic insight into a potential upstream regulator of chemokine expression in AH. RESULTS. Selected C-X-C chemokine members of the Interleukin-8 (IL-8) chemokine family and C-C chemokine CCl20 were highly associated with AH compared to HC, but not in patients with liver diseases of other etiologies (NAFLD or HCV). Our previous studies implicate Macrophage migration inhibitory factor (MIF) as a pleiotropic cytokine/chemokine with the potential to coordinately regulate chemokine expression in AH. LPS-stimulated expression of multiple chemokines in cultured hepatocytes was dependent on MIF. Gao-binge ethanol feeding to mice induced a similar coordinated chemokine expression in livers of wild-type mice; this was prevented in hepatocyte-specific Mif knockout (MifΔHep) mice. CONCLUSIONS. This study demonstrates that patients with AH exhibit a specific, coordinately expressed chemokine signature and hepatocyte-derived MIF might drive this inflammatory response.
Authors
Kyle L. Poulsen, Xiude D. Fan, Christopher D. Kibler, Emily Huang, Xiaoqin Wu, Megan R. McMullen, Lin Leng, Richard Bucala, Meritxell Ventura-Cots, Josepmaria Argemi, Ramon Bataller, Laura E. Nagy
Abstract
Idiopathic Pulmonary Fibrosis (IPF) is characterized by aberrant repair that diminishes lung function via mechanisms that remain poorly understood. C-C chemokine receptor (CCR10) and its ligand, CCL28, were both elevated in IPF compared with normal donors. CCR10 was highly expressed by various cells from IPF lungs, most notably stage-specific embryonic antigen (SSEA)-4+ mesenchymal progenitor cells (MPCs). In vitro, CCL28 promoted the proliferation of CCR10+ MPCs while CRISPR-Cas9-mediated targeting of CCR10 resulted in the death of MPCs. Following the intravenous injection of various cells from IPF lungs into immunodeficient (NSG) mice, human CCR10+ cells initiated and maintained fibrosis in NSG mice. Eph receptor A3 (EphA3) was among the highest expressed receptor tyrosine kinases detected on IPF CCR10+ cells. Ifabotuzumab-targeted killing of EphA3+ cells significantly reduced the numbers of CCR10+ cells and ameliorated pulmonary fibrosis in humanized NSG mice. Thus, human CCR10+ cells promote pulmonary fibrosis and EphA3 mAb-directed elimination of these cells inhibits lung fibrosis.
Authors
Miriam S. Hohmann, David M. Habiel, Milena S. Espindola, Guanling Huang, Isabelle Jones, Rohan Narayanan, Ana Lucia Coelho, Justin M. Oldham, Imre Noth, Shwu-Fan Ma, Adrianne Kurkciyan, Jonathan L. McQualter, Gianni Carraro, Barry Stripp, Peter Chen, Dianhua Jiang, Paul W. Noble, William Parks, John Woronicz, Geoffrey Yarranton, Lynne A. Murray, Cory M. Hogaboam
Abstract
Long noncoding RNAs (lncRNAs) are increasingly implicated in the pathology of diabetic complications. Here we examined the role of lncRNAs in monocyte dysfunction and inflammation associated with human type 2 diabetes mellitus (T2D). RNA-seq analysis of CD14+ monocytes from patients with T2D versus healthy controls revealed downregulation of anti-inflammatory and anti-proliferative genes along with several lncRNAs, including a novel divergent lncRNA DRAIR (Diabetes Regulated anti-inflammatory RNA) and its nearby gene CPEB2. High glucose and palmitic acid downregulated DRAIR in cultured CD14+ monocytes, whereas anti-inflammatory cytokines and monocyte-to-macrophage differentiation upregulated DRAIR via KLF4 transcription factor. DRAIR overexpression increased anti-inflammatory and macrophage differentiation genes but inhibited pro-inflammatory genes. Conversely, DRAIR knockdown attenuated anti-inflammatory genes, promoted inflammatory responses, and inhibited phagocytosis. DRAIR regulated target gene expression through interaction with chromatin, and inhibition of the repressive epigenetic mark H3K9me2 and its corresponding methyltransferase G9a. Mouse orthologous Drair and Cpeb2 were also downregulated in peritoneal macrophages from T2D db/db mice, and Drair knockdown in non-diabetic mice enhanced pro-inflammatory genes in macrophages. Thus, DRAIR modulates inflammatory phenotype of monocytes/macrophages via epigenetic mechanisms, and its downregulation in T2D may promote chronic inflammation. Augmentation of endogenous lncRNAs like DRAIR could serve as novel anti-inflammatory therapies for diabetic complications.
Authors
Marpadga A. Reddy, Vishnu Amaram, Sadhan Das, Vinay Singh Tanwar, Rituparna Ganguly, Mei Wang, Linda Lanting, Linxiao Zhang, Maryam Abdollahi, Zhuo Chen, Xiwei Wu, Sridevi Devaraj, Rama Natarajan
Abstract
Clinical phenotyping of term and preterm labor is imprecise, and disagreement persists on categorization relative to underlying pathobiology, which remains poorly understood. We performed RNA sequencing (RNA-seq) of 31 specimens of human uterine myometrium from 10 term and 21 preterm cesarean deliveries with rich clinical context information. A molecular signature of 4,814 transcripts stratified myometrial samples into quiescent (Q) and non-quiescent (NQ) phenotypes, independent of gestational age and incision site. Similar stratifications were achieved using expressed genes in Ca2+ signaling and TGF-β pathways. For maximal parsimony, we evaluated the expression of just two Ca2+ transporter genes, ATP2B4 (encoding PMCA4) and ATP2A2 (coding for SERCA2), and found that their ratio reliably distinguished NQ and Q specimens in the current study, and also in two publically available RNA-seq datasets (GSE50599 and GSE80172), with an overall AUC of 0.94. Cross-validation of the ATP2B4/ATP2A2 ratio by qPCR in an expanded cohort (by 11 additional specimens) achieved complete separation (AUC=1.00) of NQ vs. Q specimens. While providing additional insight into the associations between clinical features of term and preterm labor and myometrial gene expression, our study also offers a practical algorithm for unbiased classification of myometrial biopsies by their overall contractile program.
Authors
William E. Ackerman IV, Catalin S. Buhimschi, Ali Snedden, Taryn L. Summerfield, Guomao Zhao, Irina A. Buhimschi
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