Malignant melanoma is a major public health issue displaying frequent resistance to targeted therapy and immunotherapy. A major challenge is to better understand how melanoma cells evade immune elimination and how tumor growth and metastasis is facilitated by tumor microenvironment. Here, we show that expression of the cytokine TSLP by epidermal keratinocytes is induced by cutaneous melanoma in both mice and humans. Using genetically engineered models of melanoma and tumor cell grafting combined with TSLP knockout or overexpression, we defined a crosstalk between melanoma cells, keratinocytes and immune cells in establishing a tumor promoting microenvironment. Keratinocyte-derived TSLP is induced by signal(s) derived from melanoma cells and subsequently acts via immune cells to promote melanoma progression and metastasis. Furthermore, we show that TSLP signals through TSLPR-expressing dendritic cells to play an unrecognized role in promoting GATA3+ Tregs expressing a gene signature including ST2, CCR8, ICOS, PD-1, CTLA-4 and OX40 and exhibiting a potent suppressive activity on CD8+ T cell proliferation and IFNγ production. An analogous population of GATA3-expressing Tregs was also identified in human melanoma tumors. Together, our study provides novel insights into the role of TSLP in programming a pro-tumoral immune microenvironment in cutaneous melanoma.
Wenjin Yao, Beatriz German, Dounia Chraa, Antoine Braud, Cecile Hugel, Pierre Meyer, Guillaume Davidson, Patrick Laurette, Gabrielle Mengus, Eric Flatter, Pierre Marschall, Justine Segaud, Marine Guivarch, Pierre Hener, Marie-Christine Birling, Dan Lipsker, Irwin Davidson, Mei Li
Obesity-induced asthma responds poorly to all current pharmacological interventions, including steroids; suggesting that classic, eosinophilic inflammation is not a mechanism. As insulin resistance and hyperinsulinemia are common in obese individuals and associated with increased risk of asthma, we used diet-induced obese mice to study how insulin induces airway hyperreactivity. Inhaled 5-HT or methacholine induced dose dependent bronchoconstriction that was significantly potentiated in obese mice. Cutting the vagus nerves eliminated bronchoconstriction in both obese and non-obese animals indicating it was mediated by a neural reflex. There was significantly greater density of airway sensory nerves in obese than in non-obese mice. Deleting insulin receptors on sensory nerves prevented the increase in sensory nerve density and prevented airway hyperreactivity in obese mice with hyperinsulinemia. Our data demonstrate that high levels of insulin drives obesity-induced airway hyperreactivity by increasing sensory innervation of the lung. Therefore, pharmacological interventions to control metabolic syndrome and limit reflex-mediated bronchoconstriction may be a more effective approach to reduce asthma exacerbations in obese and asthmatic patients.
Gina N. Calco, Jessica N. Maung, David B. Jacoby, Allison D. Fryer, Zhenying Nie
Puberty is associated with transient insulin resistance that normally recedes at the end of puberty; however, in overweight children insulin resistance persists leading to an increased risk of type 2 diabetes. The mechanisms whereby pancreatic β cells adapt to pubertal insulin resistance, and how they are affected by the metabolic status, have not been investigated. Here we show that puberty is associated with a transient increase in β-cell proliferation in rats and humans of both sexes. In rats, β-cell proliferation correlated with a rise in growth hormone (GH) levels. Serum from pubertal rats and humans promoted β-cell proliferation, suggesting the implication of a circulating factor. In pubertal rat islets, expression of genes of the GH/serotonin (5-HT) pathway underwent changes consistent with proliferative effect. Inhibition of the pro-proliferative 5-HT receptor isoform HTR2B blocked the increase in β-cell proliferation in pubertal islets ex vivo and in vivo. Peri-pubertal metabolic stress blunted β-cell proliferation during puberty and led to altered glucose homeostasis later in life. This study identifies a role of GH/GHR/5-HT/HTR2B signaling in the control of β-cell mass expansion during puberty and a mechanistic link between pubertal obesity and the risk of developing type 2 diabetes.
Anne-Laure Castell, Clara Goubault, Mélanie Ethier, Grace Fergusson, Caroline Tremblay, Marie Baltz, Dorothée Dal Soglio, Julien Ghislain, Vincent Poitout
Acute kidney injury (AKI) represents a common complication in critically ill patients that is associated with increased morbidity and mortality. In a murine AKI model induced by ischemia-reperfusion-injury (IRI), we show that glutamine significantly decreases kidney damage and improves kidney function. We demonstrate that glutamine causes transcriptomic and proteomic reprogramming in murine renal tubular epithelial cells (TECs), resulting in decreased epithelial apoptosis, neutrophil recruitment and improved mitochondrial functionality and respiration provoked by an ameliorated oxidative phosphorylation. We identify the proteins glutamine gamma glutamyltransferase 2 (Tgm2) and apoptosis signal-regulating kinase (Ask1) as the major targets of glutamine in apoptotic signaling. Furthermore, the direct modulation of the Tgm2-HSP70 signalosome and reduced Ask1 activation result in decreased JNK activation leading to diminished mitochondrial intrinsic apoptosis in TECs. Glutamine administration attenuated kidney damage in vivo during AKI and TEC viability in vitro under inflammatory or hypoxic conditions.
Katharina Thomas, Lisa Zondler, Nadine Ludwig, Marina Kardell, Corinna Lüneburg, Katharina Henke, Sina Mersmann, Andreas Margraf, Tilmann Spieker, Tobias Tekath, Ana Velic, Richard Holtmeier, Juliane Hermann, Vera Jankowski, Melanie Meersch, Dietmar Vestweber, Martin Westphal, Johannes Roth, Michael A. Schaefers, John A. Kellum, Clifford A. Lowell, Jan Rossaint, Alexander Zarbock
High-fat diet (HFD) contributes to the increased incidence of colorectal cancer; but the mechanisms are unclear. We found that R-spondin 3 (Rspo3), a ligand for LGR4 and LGR5, was the major subtype and produced by myofibroblasts beneath the crypts in the intestine; HFD upregulated colonic Rspo3, LGR4, LGR5 and β-catenin gene expressions in specific pathogen free rodents, but not in germfree mice, and the upregulations were prevented by bile acids (BA) binder, cholestyramine (CHO) or antibiotic treatment, indicating mediating by both BA and gut microbiota. CHO or antibiotic treatments prevented HFD-induced enrichment of Lachnospiraceae and Rumincoccaceae, which are capable of transforming 10 into 20 BA. Oral administration of deoxycholic acid (DCA), or inoculation of a combination of BA deconjugator Lactobacillus plantarum and 7-α-dehydroxylase-containing Clostridium scindens with HFD to germfree mice increased colonic Rspo3 mRNA, indicating that formation of 20 BA by gut microbiota is responsible for HFD-induced upregulation of Rspo3. In primary myofibroblasts DCA increased Rpso3 mRNA via TGR5. Finally, we showed that CHO or conditional deletion of Rspo3 prevented HFD- or DCA- induced intestinal proliferation. We conclude that secondary BA is responsible for HFD-induced upregulation of Rspo3, which in turn mediates HFD-induced intestinal epithelial proliferation.
Ji-Yao Li, Merritt Gillilland III, Allen A. Lee, Xiaoyin Wu, Shi-Yi Zhou, Chung Owyang
Transforming growth factor beta 1 (TGFβ1) plays a central role in normal and aberrant wound healing, but the precise mechanism in the local environment remains elusive. Here, using a mouse model of aberrant wound healing resulting in heterotopic ossification (HO) after traumatic injury, we find autocrine TGFβ1 signaling in macrophages, and not mesenchymal stem/progenitor cells (MPCs), is critical in HO formation. In-depth single cell transcriptomic and epigenomic analyses in combination with immunostaining of cells from the injury site demonstrate increased TGFβ1 signaling in early infiltrating macrophages, with open chromatin regions in TGFβ1 stimulated genes at binding sites specific for transcription factors of activated TGFβ1 (SMAD2/3). Genetic deletion of TGFβ1 receptor type 1, (Tgfbr1;Alk5) in macrophages, results in increased HO, with a trend toward decreased tendinous HO. To bypass the effect seen by altering the receptor we administered a systemic treatment with TGFβ1/3 ligand trap TGFβRII-Fc, which results in decreased HO formation and a delay macrophage infiltration to the injury site. Overall, our data support the role of the TGFβ1/ALK5 signaling pathway in HO.
Nicole K. Patel, Johanna H. Nunez, Michael Sorkin, Simone Marini, Chase A. Pagani, Amy L. Strong, Charles D. Hwang, Shuli Li, Karthik R. Padmanabhan, Ravi Kumar, Alec C. Bancroft, Joseph A. Greenstein, Reagan Nelson, Husain A. Rasheed, Nicholas Livingston, Kaetlin Vasquez, Amanda K. Huber, Benjamin Levi
Gene mutations causing loss of dystrophin result in the severe muscle disease known as Duchenne muscular dystrophy (DMD). Despite efforts at genetic repair, DMD therapy remains largely palliative. Loss of dystrophin destabilizes the sarcolemmal membrane impacting mechanosensitive cation channels to increase calcium entry, promoting cell damage, and eventually muscle dysfunction. One putative channel is transient receptor potential canonical 6 (TRPC6) that we showed contributes to abnormal force and calcium stress-responses in mouse cardiomyocytes lacking dystrophin and haplodeficient in utrophin mdx/utrn+/- (HET). Here, we show in both HET and the far more severe homozygous mdx/utrn-/- (DKO) mouse that TRPC6 gene deletion or its selective pharmacologic inhibition (BI 749327) prolongs survival 2-3-fold, improving skeletal and cardiac muscle and bone defects. Gene pathways reduced by BI 749327 treatment most prominently regulate fat metabolism and TGFβ1 signaling. These results support the testing of TRPC6 inhibitors in human trials for other diseases as a novel DMD therapy.
Brian L. Lin, Joseph Y. Shin, William P.D. Jeffreys, Nadan Wang, Clarisse A. Lukban, Megan C. Moorer, Esteban Velarde, Olivia A. Hanselman, Seoyoung Kwon, Suraj Kannan, Ryan C. Riddle, Christopher W. Ward, Steven S. Pullen, Antonio Filareto, David A. Kass
Biased agonism is a frontier field in G-protein coupled receptor (GPCR) research. Acquired hypocalciuric hypercalcemia (AHH) is a rare disease caused by calcium-sensing receptor (CaSR) autoantibodies, to date, showing either simple blocking or biased properties (i.e., stimulatory or blocking effects on different downstream signaling pathways). This emphasizes the importance of the Gi/o (pertussis toxin-sensitive G proteins, whose βγ subunits activate multiple signals including ERK1/2) in regulating PTH secretion. We here describe three patients with symptomatic AHH that shared characteristics with the two cases we previously reported as follows: [1] aged (between 74-87 years at diagnosis); [2] male; [3] unexpectedly showed no other autoimmune diseases; [4] showed spontaneously fluctuating calcium levels from approximately normal to near fatally high ranges; [5] acute exacerbations could be successfully treated with prednisolone and/or calcimimetics; [6] the presence of CaSR autoantibodies that operated as biased allosteric modulators of CaSR; and that [7] were likely to be conformational (i.e., recognizing and thereby stabilizing a unique active conformation of CaSR that activates Gq/11, activating phosphatidylinositol turnover, but not Gi/o). Our observations with these prominent commonalities may provide new insights into the phenotype and characteristics of AHH and the mechanisms by which the biased agonism of GPCRs operate.
Noriko Makita, Junichiro Sato, Katsunori Manaka, Kimiko Akahane, Takahiro Ito, Hajime Yamazaki, Akira Mizoguchi, Yusuke Hikima, Hirofumi Horikoshi, Masaomi Nangaku, Taroh Iiri
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
BACKGROUND. Metabolomic profiling in individuals with chronic kidney disease (CKD) has the potential to identify novel biomarkers and provide insight into disease pathogenesis. Methods: We examined the association between blood metabolites and CKD progression, defined as the subsequent development of end-stage renal disease (ESRD) or estimated glomerular filtrate rate (eGFR) halving, in 1773 participants of the Chronic Renal Insufficiency Cohort (CRIC) study, 962 participants of the African American Study of Kidney Disease and Hypertension (AASK), and 5305 participants of the Atherosclerosis Risk in Communities (ARIC) study. RESULTS. In CRIC, more than half of measured metabolites were associated with CKD progression in minimally adjusted Cox proportional hazards models, but the number and strength of associations were markedly attenuated by serial adjustment for covariates, particularly eGFR. Ten metabolites were significantly associated with CKD progression in fully-adjusted models in CRIC; three of these metabolites were also significant in fully-adjusted models in AASK and ARIC, highlighting potential markers of glomerular filtration (pseudouridine), histamine metabolism (methylimidazoleacetate), and azotemia (homocitrulline). Our findings also nominate N-acetylserine as a potential marker of kidney tubular function, with significant associations with CKD progression observed in CRIC and ARIC. CONCLUSION. Together, our findings demonstrate the application of metabolomics to identify potential biomarkers and causal pathways in CKD progression. TRIAL REGISTRATION. Not applicable FUNDING. This study was supported by the NIH (U01 DK106981, U01 DK106982, U01 DK085689, R01 DK108803, R01 DK124399)
Donghai Wen, Zihe Zheng, Aditya Surapaneni, Bing Yu, Linda Zhou, Wen Zhou, Dawei Xie, Haochang Shou, Julian Avila-Pacheco, Sahir Kalim, Jiang He, Chi-yuan Hsu, Afshin Parsa, Panduranga Rao, James Sondheimer, Raymond Townsend, Sushrut S. Waikar, Casey M. Rebholz, Michelle R. Denburg, Paul L. Kimmel, Ramachandran S. Vasan, Clary B. Clish, Josef Coresh, Harold I. Feldman, Morgan E. Grams, Eugene P. Rhee
BACKGROUND. Increased reinfection rates with SARS-CoV-2 have recently been reported, with some locations basing reinfection on a second positive PCR test at least 90 days after initial infection. In this study, we used the Johns Hopkins SARS-CoV-2 genomic surveillance data to evaluate the frequency of sequencing validated, confirmed and inferred reinfections between March 2020 and July 2022. METHODS. Patients who had two or more positive SARS-CoV-2 tests in our system with samples sequenced as a part of our surveillance efforts were identified as the cohort for our study. SARS-CoV-2 genomes of patients’ initial and later samples were compared. RESULTS. A total of 755 patients (920 samples) had a positive test at least 90 days after the initial test with a median time between tests of 377 days. Sequencing was attempted on 231 samples and was successful in 127. Successful sequencing spiked during the Omicron surge and showed higher median days from initial infection compared to failed sequences. A total of 122 (98%) patients showed evidence of reinfection, 45 of which had sequence validated reinfection and 77 had inferred reinfections (later sequence showed a clade that was not circulating when the patient was initially infected). Of 45 sequence validated reinfections, 43 (96%) were caused by the Omicron variant, 41 (91%) were symptomatic, 32 (71%) were vaccinated prior to the second infection, 6 (13%) were Immunosuppressed, and only 2 (4%) were hospitalized. CONCLUSIONS. Sequence validated reinfections increased with the Omicron variant but were generally associated with mild infections.
C. Paul Morris, Raghda E. Eldesouki, Amary Fall, David C. Gaston, Julie M. Norton, Nicholas D. Gallagher, Chun Huai Luo, Omar Abdullah, Eili Y. Klein, Heba H. Mostafa