A central feature of progressive vascular remodeling is altered smooth muscle cell (SMC) homeostasis; however, the understanding of how different cell populations contribute to this process is limited. Here, we utilized single cell RNA sequencing to provide insight into cellular composition changes within isolated pulmonary arteries (PA) from pulmonary arterial hypertension (PAH) and donor lungs. Our results revealed that remodeling skewed the balanced communication network between immune and structural cells, in particular SMC. Comparative analysis with murine PA showed that human PA harbor heterogeneous SMC populations with an abundant intermediary cluster displaying a gradient transition between SMC and adventitial fibroblasts. Transcriptionally distinct SMC populations were enriched in specific biological processes and could be distinguished into four major clusters: oxygen sensing (enriched in pericytes), contractile, synthetic and fibroblast-like. End-stage remodeling was associated with phenotypic shift of pre-existing SMC populations and accumulation of synthetic SMC in neointima. Distinctly regulated genes in clusters built non-redundant regulatory hubs encompassing stress response and differentiation regulators. The current study provides a blueprint of cellular and molecular changes on a single cell level that are defining pathological vascular remodeling process.
Slaven Crnkovic, Francesco Valzano, Elisabeth Fließer, Juergen Gindlhuber, Helene Thekkekara Puthenparampil, Maria C. Basil, Michael P. Morley, Jeremy Katzen, Elisabeth Gschwandtner, Walter Klepetko, Edward Cantu, Heimo Wolinski, Horst Olschewski, Jorg Lindenmann, You-Yang Zhao, Edward E. Morrisey, Leigh M. Marsh, Grazyna Kwapiszewska
Low-calorie sweetener (LCS) consumption in children has increased dramatically due to widespread presence in the food environment and efforts to mitigate obesity through sugar replacement. However, mechanistic studies on the long-term impact of early-life LCS consumption on cognitive function and physiological processes are lacking. Here, we developed a rodent model to evaluate the effects of daily LCS consumption (acesulfame potassium, saccharin, or stevia) during adolescence on adult metabolic, behavioral, gut microbiome, and brain transcriptomic outcomes. Results reveal that habitual early-life LCS consumption impacts normal post-oral glucose handling and impairs hippocampal-dependent memory in the absence of weight gain. Furthermore, adolescent LCS consumption yielded long-term reductions in lingual sweet taste receptor expression and alterations in sugar-motivated appetitive and consummatory responses. While early life LCS consumption did not produce robust changes in the gut microbiome, brain region-specific RNA sequencing analyses reveal LCS-induced changes in collagen- and synaptic signaling-related gene pathways in the hippocampus and nucleus accumbens, respectively, in a sex-dependent manner. Collectively, these results reveal that habitual early-life LCS consumption has long lasting implications for glucoregulation, sugar-motivated behavior, and hippocampal-dependent memory in rats, which may be based in part on changes in nutrient transporter, sweet taste receptor, and central gene pathway expression.
Linda Tsan, Sandrine Chometton, Anna M.R. Hayes, Molly E. Klug, Yanning Zuo, Shan Sun, Lana Bridi, Rae Lan, Anthony A. Fodor, Emily E. Noble, Xia Yang, Scott E. Kanoski, Lindsey A. Schier
Thy-1 (CD90) is a well-known marker of fibroblasts implicated in organ fibrosis, but its contribution to skin fibrosis remains unknown. We examined Thy-1 expression in scleroderma skin and its potential role as a biomarker and pathogenic factor in animal models of skin fibrosis. Skin from patients with systemic sclerosis demonstrates markedly elevated Thy-1 expression compared to controls, co-localizes with fibroblast activator protein (FAP) in the deep dermis, and is correlated with the severity of skin involvement (MRSS). Serial imaging of skin from Thy-1 YFP reporter mice by IVIS showed an increase in Thy-1 expression which correlated with onset and progression of fibrosis. In contrast to lung fibrosis, Thy-1 KO mice had attenuated skin fibrosis in both bleomycin and Tsk-1 murine models. Moreover, Thy-1 regulated key pathogenic pathways involved in fibrosis including inflammation, myofibroblast differentiation, apoptosis and multiple additional canonical fibrotic pathways. Therefore, while Thy-1 deficiency leads to exacerbated lung fibrosis, in skin it is protective. Moreover, Thy-1 may serve as a longitudinal marker to assess skin fibrosis.
Roberta G. Marangoni, Poulami Datta, Ananta Paine, Stacey Duemmel, Marc A. Nuzzo, Laura Sherwood, John Varga, Christopher Ritchlin, Benjamin D. Korman
Uterine fibroids (leiomyomas) affect Black women disproportionately in terms of prevalence, incidence, and severity of symptoms. The causes of this racial disparity are essentially unknown. We hypothesized that myometria of Black women are more susceptible to developing fibroids and examined the transcriptomic and DNA methylation profiles of myometria and fibroids from Black and White women for comparison. Myometrial samples cluster by race in both their transcriptome and DNA methylation profiles, whereas fibroid samples only cluster by race in the latter. More differentially expressed genes (DEGs) were detected in the Black and White myometrial sample comparison than in the fibroid comparison. Leiomyoma gene set expression analysis identified four clusters of DEGs, including a cluster of 24 genes with higher expression in myometrial samples from Black women. One of the DEGs in this group, VWF, was significantly hypomethylated at two CpG probes that are near a putative enhancer site in myometrial samples from Black women and in all fibroids and that correlate with VWF expression levels. These results suggest that the molecular basis for the disparity in fibroid disease between Black and White women could be found in the myometria before fibroid development and not in the fibroids themselves.
Emmanuel N. Paul, Joshua A. Grey, Tyler J. Carpenter, Zachary B. Madaj, Kin H. Lau, Scott A. Givan, Gregory W. Burns, Ronald L. Chandler, Ganesa R. Wegienka, Hui Shen, Jose M. Teixeira
The histone methyltransferase PRC2 plays a complex role in cancer. Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas with frequent loss-of-function mutations in PRC2 that are associated with poor outcome. Here, we identify a critical role for PRC2 loss in driving MPNST metastasis. PRC2-dependent metastatic phenotypes include increased collagen-dependent invasion, upregulation of matrix remodeling enzymes, and elevated lung metastasis in orthotopic mouse models. Furthermore, clinical sample analysis determines that PRC2 loss correlates with metastatic disease, increased fibrosis, and decreased survival in MPNST patients. These results may have broad implications for PRC2 function across multiple cancers and provide a strong rationale for investigating potential therapies targeting ECM remodeling enzymes and tumor fibrosis to improve outcomes in MPNST patients.
Qierra R. Brockman, Amanda Scherer, Gavin R. McGivney, Wade R. Gutierrez, Andrew P. Voigt, Alexandra L. Isaacson, Emily A. Laverty, Grace Roughton, Vickie Knepper-Adrian, Benjamin Darbro, Munir R. Tanas, Christopher S. Stipp, Rebecca D. Dodd
BACKGROUND. Alcohol use disorder (AUD) is a chronic, relapsing brain disorder that accounts for 5% of deaths annually, and there is an urgent need to develop new targets for therapeutic intervention. The glucagon-like peptide-1 receptor agonist exenatide reduces alcohol consumption in rodents and non-human primates, but its efficacy in patients with AUD is unknown. METHODS. In a randomized, double-blinded, placebo-controlled clinical trial, treatment-seeking AUD patients were assigned to receive exenatide (2 mg subcutaneously) or placebo once weekly for 26-weeks, in addition to standard cognitive-behavioral therapy. The primary outcome was reduction in number of heavy drinking days. A subgroup also completed fMRI and SPECT brain scans. RESULTS. A total of 127 patients were enrolled. Our data revealed that although exenatide did not significantly reduce the number of heavy drinking days compared to placebo, it significantly attenuated fMRI alcohol cue-reactivity in the ventral striatum and septal area, which are crucial brain areas for drug reward and addiction. In addition, the dopamine transporter availability was lower in the exenatide group compared to the placebo group. Exploratory analyses revealed that exenatide significantly reduced heavy drinking days and total alcohol intake in a subgroup of obese patients (BMI>30 kg/m2). Adverse events were mainly gastrointestinal. CONCLUSIONS. This first RCT on the effects of a GLP-1 receptor agonist in AUD provides new important knowledge on the effects of GLP-1 receptor agonists as a novel treatment target in addiction. TRIAL REGISTRATION. EudraCT: 2016-003343-11 and ClinicalTrials.gov: NCT03232112 FUNDING. The Novavi Foundation; The Research Foundation, Mental Health Services, Capital Region of Denmark; The Research Foundation, Capital Region of Denmark; The Ivan Nielsen Foundation; The A.P. Moeller and wife Chastine Mc-Kinney Moellers Family Foundation; The Augustinus Foundation; The Woerzner Foundation; Grosserer L.F Foghts Foundation; The Hartmann Foundation; The Aase and Ejnar Danielsen Foundation; The P.A. Messerschmidt and wife foundation and The Lundbeck Foundation. The funding sources and the manufacturer of exenatide once weekly (Bydureon®, AstraZeneca), had no influence on the trial design or data analysis.
Mette K. Klausen, Mathias E. Jensen, Marco Møller, Nina le Dous, Anne-Marie Ø Jensen, Victoria A. Zeeman, Claas-Frederik Johannsen, Alycia M. Lee, Gerda K. Thomsen, Julian Macoveanu, Patrick M Fisher, Matthew P. Gillum, Niklas R. Jørgensen, Marianne L. Bergmann, Henrik Enghusen Poulsen, Ulrik Becker, Jens Juul Holst, Helene Benveniste, Nora D. Volkow, Sabine Vollstädt-Klein, Kamilla W. Miskowiak, Claus T. Ekstrøm, Gitte M. Knudsen, Tina Visboll, Anders Fink-Jensen
The kidney contains a population of resident macrophages from birth that expands as it grows and forms a contiguous network throughout the tissue. Kidney resident macrophages (KRMs) are important in homeostasis and the response to acute kidney injury (AKI). While the kidney contains many microenvironments, it is unknown whether KRMs are a heterogeneous population differentiated by function and location. We combined single-cell RNA sequencing (scRNAseq), spatial transcriptomics, flow cytometry, and immunofluorescence imaging to localize, characterize, and validate KRM populations during quiescence and following 19 minutes of bilateral ischemic kidney injury. scRNAseq and spatial transcriptomics revealed seven distinct KRM subpopulations, which are organized into zones corresponding to regions of the nephron. Each subpopulation was identifiable by a unique transcriptomic signature suggesting distinct functions. Specific protein markers were identified for two clusters allowing analysis by flow cytometry or immunofluorescence imaging. Following injury, the original localization of each subpopulation is lost, either from changing locations or transcriptomic signatures. The original spatial distribution of KRMs is not fully restored for at least 28 days post-injury. The change in KRM localization confirms a long hypothesized dysregulation of the local immune system following acute injury and may explain the increased risk for chronic kidney disease.
Matthew D. Cheung, Elise N. Erman, Kyle H. Moore, Jeremie M.P. Lever, Zhang Li, Jennifer R. LaFontaine, Gelare Ghajar-Rahimi, Shanrun Liu, Zhengqin Yang, Rafay Karim, Bradley K. Yoder, Anupam Agarwal, James F. George
Clinical studies of cancer patients have shown that overexpression or amplification of thymidylate synthase (TS) correlates with a worse clinical outcome. We previously showed that elevated TS exhibits properties of an oncogene and promotes pancreatic neuroendocrine tumors (PanNETs) with a long latency. To study the causal impact of elevated TS levels in PanNETs, we generated a mouse model with elevated human TS (hTS) and conditional inactivation of Men1 gene in pancreatic islet cells (hTS/Men1-/-). We demonstrated that increased hTS expression was associated with earlier tumor onset and accelerated PanNET development as compared to control Men1-/- and Men1+/ΔN3-8 mice. We also observed decrease in overall survival of hTS/Men1+/- and hTS/Men1-/- mice as compared to control mice. We showed that elevated hTS in Men1-deleted tumor cells enhanced cell proliferation, deregulated cell cycle kinetics and was associated with a higher frequency of somatic mutations, DNA damage and genomic instability. In addition, we analyzed survival of 88 PanNET patients and observed that high TS protein expression independently predicted worse clinical outcome. In summary, elevated hTS directly participates in promoting PanNET tumorigenesis with reduced survival in Men1 mutant background. This work will re-focus attention on new strategies to inhibit TS activity for PanNET treatment.
Vinod Vijayakurup, Kyungah Maeng, Hye Seung Lee, Benjamin S. Meyer, Sandra Burkett, Akbar Nawab, Michael W. Dougherty, Christian Jobin, Iqbal Mahmud, Timothy J. Garrett, Michael Feely, Kyoung Bun Lee, Frederic J. Kaye, Maria V. Guijarro, Maria Zajac-Kaye
Bone marrow adipocytes (BMAd) are a unique cell population derived from bone marrow mesenchymal progenitors and marrow adipogenic lineage precursors. Although they have long been considered to be a space-filler within bone cavities, recent studies have revealed important physiological roles in hematopoiesis and bone metabolism. To date, the approaches used to study BMAd function have been confounded by contributions by non-marrow adipocytes or by bone marrow stromal cells. To address this gap in the field, we have developed a BMAd-specific Cre mouse model to deplete BMAds by expression of diphtheria toxin A (DTA), or by deletion of peroxisome proliferator-activated receptor gamma (Pparg). We found that DTA-induced loss of BMAds results in decreased hematopoietic stem and progenitor cell numbers and increased bone mass in BMAd-enriched locations, including the distal tibiae and caudal vertebrae. Elevated bone mass appears to be secondary to enhanced endosteal bone formation, suggesting a local effect caused by depletion of BMAd. Augmented bone formation with BMAd-depletion protects mice from bone loss induced by caloric restriction or ovariectomy, and facilitates the bone healing process after fracture. Finally, ablation of Pparg also reduces BMAd numbers and largely recapitulates high bone mass phenotypes observed with DTA-induced BMAd depletion.
Ziru Li, Devika P. Bagchi, Junxiong Zhu, Emily Bowers, Hui Yu, Julie Hardij, Hiroyuki Mori, Katrina Granger, Jonathan D. Skjaerlund, Gurjit S. Mandair, Simin Abrishami, Kanakadurga Singer, Kurt D. Hankenson, Clifford J. Rosen, Ormond A. MacDougald
Pseudomonas aeruginosa is one of the most common nosocomial infections worldwide, and frequently causes ventilator-associated acute pneumonia in immunocompromised patients. Abundant neutrophil extracellular traps (NETs) contribute to acute lung injury, thereby aggravating ventilator-induced lung damage. While pattern recognition receptors (PRRs) TLR4 and TLR5 are required for host defense against P. aeruginosa invasion, the PRR responsible for P. aeruginosa-induced NET formation, proinflammatory cytokine release, and acute lung injury remains unclear. We found that myeloid C-type lectin domain family 5 member A (CLEC5A) interacts with lipopolysaccharides of P. aeruginosa, and is responsible for P. aeruginosa-induced NET formation and lung inflammation. P. aeruginosa activates CLEC5A to induce caspase-1-dependent NET formation, but it neither causes gasdermin D (GSDMD) cleavage nor contributes to P. aeruginosa-induced neutrophil death. Blockade of CLEC5A attenuates P. aeruginosa-induced NETosis and lung injury, and simultaneous administration of anti-CLEC5A mAb with ciprofloxacin increases survival rate and decreases collagen deposition in the lungs of mice challenged with a lethal dose of P. aeruginosa. Thus, CLEC5A is a promising therapeutic target to reduce ventilator-associated lung injury and fibrosis in P. aeruginosa-induced pneumonia.
Pei-Shan Sung, Yu-Chun Peng, Shao-Ping Yang, Cheng-Hsun Chiu, Shie-Liang Hsieh
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