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BACKGROUND While the benefits of statin therapy on atherosclerotic cardiovascular disease are clear, patients often experience mild to moderate skeletal myopathic symptoms, the mechanism for which is unknown. This study investigated the potential effect of high-dose atorvastatin therapy on skeletal muscle mitochondrial function and whole-body aerobic capacity in humans.METHODS Eight overweight (BMI, 31.9 ± 2.0) but otherwise healthy sedentary adults (4 females, 4 males) were studied before (day 0) and 14, 28, and 56 days after initiating atorvastatin (80 mg/d) therapy.RESULTS Maximal ADP-stimulated respiration, measured in permeabilized fiber bundles from muscle biopsies taken at each time point, declined gradually over the course of atorvastatin treatment, resulting in > 30% loss of skeletal muscle mitochondrial oxidative phosphorylation capacity by day 56. Indices of in vivo muscle oxidative capacity (via near-infrared spectroscopy) decreased by 23% to 45%. In whole muscle homogenates from day 0 biopsies, atorvastatin inhibited complex III activity at midmicromolar concentrations, whereas complex IV activity was inhibited at low nanomolar concentrations.CONCLUSION These findings demonstrate that high-dose atorvastatin treatment elicits a striking progressive decline in skeletal muscle mitochondrial respiratory capacity, highlighting the need for longer-term dose-response studies in different patient populations to thoroughly define the effect of statin therapy on skeletal muscle health.FUNDING NIH R01 AR071263.
Terence E. Ryan, Maria J. Torres, Chien-Te Lin, Angela H. Clark, Patricia M. Brophy, Cheryl A. Smith, Cody D. Smith, E. Matthew Morris, John P. Thyfault, P. Darrell Neufer
Total views: 2789
Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disorder accounting for approximately 5% of patients with renal failure, yet therapeutics for the treatment of ADPKD remain limited. ADPKD tissues display abnormalities in the biogenesis of the centrosome, a defect that can cause genome instability, aberrant ciliary signaling, and secretion of pro-inflammatory factors. Cystic cells form excess centrosomes via a process termed centrosome amplification (CA), which causes abnormal multipolar spindle configurations, mitotic catastrophe, and reduced cell viability. However, cells with CA can suppress multipolarity via “centrosome clustering,” a key mechanism by which cells circumvent apoptosis. Here, we demonstrate that inhibiting centrosome clustering can counteract the proliferation of renal cystic cells with high incidences of CA. Using ADPKD human cells and mouse models, we show that preventing centrosome clustering with 2 inhibitors, CCB02 and PJ34, blocks cyst initiation and growth in vitro and in vivo. Inhibiting centrosome clustering activates a p53-mediated surveillance mechanism leading to apoptosis, reduced cyst expansion, decreased interstitial fibrosis, and improved kidney function. Transcriptional analysis of kidneys from treated mice identified pro-inflammatory signaling pathways implicated in CA-mediated cystogenesis and fibrosis. Our results demonstrate that centrosome clustering is a cyst-selective target for the improvement of renal morphology and function in ADPKD.
Tao Cheng, Aruljothi Mariappan, Ewa Langner, Kyuhwan Shim, Jay Gopalakrishnan, Moe R. Mahjoub
Total views: 1281
Dynamic regulation of cellular metabolism is important for maintaining homeostasis and can directly influence immune cell function and differentiation, including NK cell responses. Persistent HIV-1 infection leads to a state of chronic immune activation, NK cell subset redistribution, and progressive NK cell dysregulation. In this study, we examined the metabolic processes that characterize NK cell subsets in HIV-1 infection, including adaptive NK cell subpopulations expressing the activating receptor NKG2C, which expand during chronic infection. These adaptive NK cells exhibit an enhanced metabolic profile in HIV-1– individuals infected with human cytomegalovirus (HCMV). However, the bioenergetic advantage of adaptive CD57+NKG2C+ NK cells is diminished during chronic HIV-1 infection, where NK cells uniformly display reduced oxidative phosphorylation (OXPHOS). Defective OXPHOS was accompanied by increased mitochondrial depolarization, structural alterations, and increased DRP-1 levels promoting fission, suggesting that mitochondrial defects are restricting the metabolic plasticity of NK cell subsets in HIV-1 infection. The metabolic requirement for the NK cell response to receptor stimulation was alleviated upon IL-15 pretreatment, which enhanced mammalian target of rapamycin complex 1 (mTORC1) activity. IL-15 priming enhanced NK cell functionality to anti-CD16 stimulation in HIV-1 infection, representing an effective strategy for pharmacologically boosting NK cell responses.
Elia Moreno-Cubero, Aljawharah Alrubayyi, Stefan Balint, Ane Ogbe, Upkar S. Gill, Rebecca Matthews, Sabine Kinloch, Fiona Burns, Sarah L. Rowland-Jones, Persephone Borrow, Anna Schurich, Michael Dustin, Dimitra Peppa
Total views: 1178
The lipidome of immune cells during infection has remained unexplored, although evidence of the importance of lipids in the context of immunity is mounting. In this study, we performed untargeted lipidomic analysis of blood monocytes and neutrophils from patients hospitalized for pneumonia and age- and sex-matched noninfectious control volunteers. We annotated 521 and 706 lipids in monocytes and neutrophils, respectively, which were normalized to an extensive set of internal standards per lipid class. The cellular lipidomes were profoundly altered in patients, with both common and distinct changes between the cell types. Changes involved every level of the cellular lipidome: differential lipid species, class-wide shifts, and altered saturation patterns. Overall, differential lipids were mainly less abundant in monocytes and more abundant in neutrophils from patients. One month after hospital admission, lipidomic changes were fully resolved in monocytes and partially in neutrophils. Integration of lipidomic and concurrently collected transcriptomic data highlighted altered sphingolipid metabolism in both cell types. Inhibition of ceramide and sphingosine-1-phosphate synthesis in healthy monocytes and neutrophils resulted in blunted cytokine responses upon stimulation with lipopolysaccharide. These data reveal major lipidomic remodeling in immune cells during infection, and link the cellular lipidome to immune functionality.
Alex R. Schuurman, Osoul Chouchane, Joe M. Butler, Hessel Peters-Sengers, Sebastiaan Joosten, Xanthe Brands, Bastiaan W. Haak, Natasja A. Otto, Fabrice Uhel, Augustijn Klarenbeek, Christine C.A. van Linge, Antoine van Kampen, Mia Pras-Raves, Michel van Weeghel, Marco van Eijk, Maria J. Ferraz, Daniël R. Faber, Alex de Vos, Brendon P. Scicluna, Frédéric M. Vaz, W. Joost Wiersinga, Tom van der Poll
Total views: 1134
TAR DNA-binding protein 43 (TDP-43) is a DNA/RNA-binding protein that regulates gene expression, and its malfunction in neurons has been causally associated with multiple neurodegenerative disorders. Although progress has been made in understanding the functions of TDP-43 in neurons, little is known about its roles in endothelial cells (ECs), angiogenesis, and vascular function. Using inducible EC-specific TDP-43–KO mice, we showed that TDP-43 is required for sprouting angiogenesis, vascular barrier integrity, and blood vessel stability. Postnatal EC-specific deletion of TDP-43 led to retinal hypovascularization due to defects in vessel sprouting associated with reduced EC proliferation and migration. In mature blood vessels, loss of TDP-43 disrupted the blood-brain barrier and triggered vascular degeneration. These vascular defects were associated with an inflammatory response in the CNS with activation of microglia and astrocytes. Mechanistically, deletion of TDP-43 disrupted the fibronectin matrix around sprouting vessels and reduced β-catenin signaling in ECs. Together, our results indicate that TDP-43 is essential for the formation of a stable and mature vasculature.
Víctor Arribas, Yara Onetti, Marina Ramiro-Pareta, Pilar Villacampa, Heike Beck, Mariona Alberola, Anna Esteve-Codina, Angelika Merkel, Markus Sperandio, Ofelia M. Martínez-Estrada, Bettina Schmid, Eloi Montanez
Total views: 1016
Neuroblastoma is an aggressive pediatric cancer with a high rate of metastasis to the bone marrow. Despite intensive treatments including high-dose chemotherapy, the overall survival rate for children with metastatic neuroblastoma remains dismal. Understanding the cellular and molecular mechanisms of the metastatic tumor microenvironment is crucial for developing new therapies and improving clinical outcomes. Here, we used single-cell RNA-sequencing to characterize immune and tumor cell alterations in neuroblastoma bone marrow metastases by comparative analysis with patients without metastases. Our results revealed remodeling of the immune cell populations and reprogramming of gene expression profiles in the metastatic niche. In particular, within the bone marrow metastatic niche we observed the enrichment of immune cells, including tumor-associated neutrophils, macrophages, and exhausted T cells, as well as an increased number of regulatory T cells and a decreased number of B cells. Furthermore, we highlighted cell communication between tumor cells and immune cell populations, and identified prognostic markers in malignant cells that are associated with worse clinical outcomes in three independent neuroblastoma cohorts. Our results provide insights into the cellular, compositional and transcriptional shifts underlying neuroblastoma bone marrow metastases contributing to the development of new therapeutic strategies.
Shenglin Mei, Adele M. Alchahin, Bethel Tesfai Embaie, Ioana Maria Gavriliuc, Bronte Manouk Verhoeven, Ting Zhao, Xiangyun Li, Nathan Elias Jeffries, Adena Pepich, Hirak Sarkar, Thale Kristin Olsen, Malin Wickström, Jakob Stenman, Oscar Reina-Bedoya, Peter V. Kharchenko, Philip J. Saylor, John Inge Johnsen, David B. Sykes, Per Kogner, Ninib Baryawno
Total views: 971
Crohn’s disease (CD) is a chronic inflammatory gut disorder. Molecular mechanisms underlying the clinical heterogeneity of CD remain poorly understood. MicroRNAs (miRNAs) are important regulators of gut physiology, and several have been implicated in the pathogenesis of adult CD. However, there is a dearth of large-scale miRNA studies for pediatric CD. We hypothesized that specific miRNAs uniquely mark pediatric CD. We performed small RNA-Seq of patient-matched colon and ileum biopsies from treatment-naive pediatric patients with CD (n = 169) and a control cohort (n = 108). Comprehensive miRNA analysis revealed 58 miRNAs altered in pediatric CD. Notably, multinomial logistic regression analysis revealed that index levels of ileal miR-29 are strongly predictive of severe inflammation and stricturing. Transcriptomic analyses of transgenic mice overexpressing miR-29 show a significant reduction of the tight junction protein gene Pmp22 and classic Paneth cell markers. The dramatic loss of Paneth cells was confirmed by histologic assays. Moreover, we found that pediatric patients with CD with elevated miR-29 exhibit significantly lower Paneth cell counts, increased inflammation scores, and reduced levels of PMP22. These findings strongly indicate that miR-29 upregulation is a distinguishing feature of pediatric CD, highly predictive of severe phenotypes, and associated with inflammation and Paneth cell loss.
Alexandria J. Shumway, Michael T. Shanahan, Emilie Hollville, Kevin Chen, Caroline Beasley, Jonathan W. Villanueva, Sara Albert, Grace Lian, Moises R. Cure, Matthew Schaner, Lee-Ching Zhu, Surekha Bantumilli, Mohanish Deshmukh, Terrence S. Furey, Shehzad Z. Sheikh, Praveen Sethupathy
Total views: 954
Age-associated sarcopenia, characterized by a progressive loss in muscle mass and strength, is the largest cause of frailty and disability in the elderly worldwide. Current treatments involve nonpharmacological guidelines that few subjects can abide by, highlighting the need for effective drugs. Preclinical models were employed to test the benefits of RJx-01, a combination drug composed of metformin and galantamine, on sarcopenia. In worms, RJx-01 treatment improved lifespan, locomotion, pharyngeal pumping, and muscle fiber organization. The synergistic effects of RJx-01 were recapitulated in a transgenic mouse model that displays an exacerbated aging phenotype (Opa1–/–). In these mice, RJx-01 ameliorated physical performance, muscle mass and force, neuromuscular junction stability, and systemic inflammation. RJx-01 also improved physical performance and muscle strength in 22-month-old WT mice and also improved skeletal muscle ultrastructure, mitochondrial morphology, autophagy, lysosomal function, and satellite cell content. Denervation and myofiber damage were decreased in RJx-01–treated animals compared with controls. RJx-01 improved muscle quality rather than quantity, indicating that the improvement in quality underlies the beneficial effects of the combination drug. The studies herein indicate synergistic beneficial effects of RJx-01 in the treatment of sarcopenia and support the pursuit of RJx-01 in a human clinical trial as a therapeutic intervention for sarcopenia.
Caterina Tezze, Francesco Ivan Amendolagine, Leonardo Nogara, Martina Baraldo, Stefano Ciciliot, Diletta Arcidiacono, Alice Zaramella, Giulio Masiero, Giulia Ferrarese, Stefano Realdon, Bert Blaauw, Giel Detienne, Ann T.J. Beliën, Marco Sandri, Evi M. Mercken
Total views: 898
Growing evidence indicates that the glucagon-like peptide-1 (GLP-1) system is involved in the neurobiology of addictive behaviors, and GLP-1 analogues may be used for the treatment of alcohol use disorder (AUD). Here, we examined the effects of semaglutide, a long-acting GLP-1 analogue, on biobehavioral correlates of alcohol use in rodents. A drinking-in-the-dark procedure was used to test the effects of semaglutide on binge-like drinking in male and female mice. We also tested the effects of semaglutide on binge-like and dependence-induced alcohol drinking in male and female rats, as well as acute effects of semaglutide on spontaneous inhibitory postsynaptic currents (sIPSCs) from central amygdala (CeA) and infralimbic cortex (ILC) neurons. Semaglutide dose-dependently reduced binge-like alcohol drinking in mice; a similar effect was observed on the intake of other caloric/noncaloric solutions. Semaglutide also reduced binge-like and dependence-induced alcohol drinking in rats. Semaglutide increased sIPSC frequency in CeA and ILC neurons from alcohol-naive rats, suggesting enhanced GABA release, but had no overall effect on GABA transmission in alcohol-dependent rats. In conclusion, the GLP-1 analogue semaglutide decreased alcohol intake across different drinking models and species and modulated central GABA neurotransmission, providing support for clinical testing of semaglutide as a potentially novel pharmacotherapy for AUD.
Vicky Chuong, Mehdi Farokhnia, Sophia Khom, Claire L. Pince, Sophie K. Elvig, Roman Vlkolinsky, Renata C.N. Marchette, George F. Koob, Marisa Roberto, Leandro F. Vendruscolo, Lorenzo Leggio
Total views: 873
Tregs can facilitate transplant tolerance and attenuate autoimmune and inflammatory diseases. Therefore, it is clinically relevant to stimulate Treg expansion and function in vivo and to create therapeutic Treg products in vitro. We report that TNF receptor 2 (TNFR2) is a unique costimulus for naive, thymus-derived Tregs (tTregs) from human blood that promotes their differentiation into nonlymphoid tissue–resident (NLT-resident) effector Tregs, without Th-like polarization. In contrast, CD28 costimulation maintains a lymphoid tissue–resident (LT-resident) Treg phenotype. We base this conclusion on transcriptome and proteome analysis of TNFR2- and CD28-costimulated CD4+ tTregs and conventional T cells (Tconvs), followed by bioinformatic comparison with published transcriptomic Treg signatures from NLT and LT in health and disease, including autoimmunity and cancer. These analyses illuminate that TNFR2 costimulation promoted tTreg capacity for survival, migration, immunosuppression, and tissue regeneration. Functional studies confirmed improved migratory ability of TNFR2-costimulated tTregs. Flow cytometry validated the presence of the TNFR2-driven tTreg signature in effector/memory Tregs from the human placenta, as opposed to blood. Thus, TNFR2 can be exploited as a driver of NLT-resident tTreg differentiation for adoptive cell therapy or antibody-based immunomodulation in human disease.
Mark Mensink, Lotte J. Verleng, Ellen Schrama, George M.C. Janssen, Rayman T.N. Tjokrodirijo, Peter A. van Veelen, Qinyue Jiang, M. Fernanda Pascutti, Marie-Louise van der Hoorn, Michael Eikmans, Sander de Kivit, Jannie Borst
Total views: 837