Other search tools

About this data

The publication data currently available has been vetted by Vanderbilt faculty, staff, administrators and trainees. The data itself is retrieved directly from NCBI's PubMed and is automatically updated on a weekly basis to ensure accuracy and completeness.

If you have any questions or comments, please contact us.

Results: 1 to 10 of 221

Publication Record

Connections

The scaffold protein p62 regulates adaptive thermogenesis through ATF2 nuclear target activation.
Fischer K, Fenzl A, Liu D, Dyar KA, Kleinert M, Brielmeier M, Clemmensen C, Fedl A, Finan B, Gessner A, Jastroch M, Huang J, Keipert S, Klingenspor M, Brüning JC, Kneilling M, Maier FC, Othman AE, Pichler BJ, Pramme-Steinwachs I, Sachs S, Scheideler A, Thaiss WM, Uhlenhaut H, Ussar S, Woods SC, Zorn J, Stemmer K, Collins S, Diaz-Meco M, Moscat J, Tschöp MH, Müller TD
(2020) Nat Commun 11: 2306
MeSH Terms: Activating Transcription Factor 2, Adipogenesis, Adipose Tissue, Brown, Adipose Tissue, White, Animals, Cell Nucleus, Magnetic Resonance Imaging, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Obesity, Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha, Positron Emission Tomography Computed Tomography, Protein Binding, Sequestosome-1 Protein, Uncoupling Protein 1, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added July 22, 2020
During β-adrenergic stimulation of brown adipose tissue (BAT), p38 phosphorylates the activating transcription factor 2 (ATF2) which then translocates to the nucleus to activate the expression of Ucp1 and Pgc-1α. The mechanisms underlying ATF2 target activation are unknown. Here we demonstrate that p62 (Sqstm1) binds to ATF2 to orchestrate activation of the Ucp1 enhancer and Pgc-1α promoter. P62 mice show reduced expression of Ucp1 and Pgc-1α with impaired ATF2 genomic binding. Modulation of Ucp1 and Pgc-1α expression through p62 regulation of ATF2 signaling is demonstrated in vitro and in vivo in p62 mice, global p62 and Ucp1-Cre p62 mice. BAT dysfunction resulting from p62 deficiency is manifest after birth and obesity subsequently develops despite normal food intake, intestinal nutrient absorption and locomotor activity. In summary, our data identify p62 as a master regulator of BAT function in that it controls the Ucp1 pathway through regulation of ATF2 genomic binding.
0 Communities
1 Members
0 Resources
18 MeSH Terms
Normal Saline solutions cause endothelial dysfunction through loss of membrane integrity, ATP release, and inflammatory responses mediated by P2X7R/p38 MAPK/MK2 signaling pathways.
Cheung-Flynn J, Alvis BD, Hocking KM, Guth CM, Luo W, McCallister R, Chadalavada K, Polcz M, Komalavilas P, Brophy CM
(2019) PLoS One 14: e0220893
MeSH Terms: Adenosine Triphosphate, Animals, Aorta, Cell Membrane, Endothelial Cells, Humans, Inflammation, Intracellular Signaling Peptides and Proteins, Phosphorylation, Protein-Serine-Threonine Kinases, Rats, Receptors, Purinergic P2X7, Saline Solution, Saphenous Vein, Signal Transduction, Swine, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added March 3, 2020
Resuscitation with 0.9% Normal Saline (NS), a non-buffered acidic solution, leads to increased morbidity and mortality in the critically ill. The goal of this study was to determine the molecular mechanisms of endothelial injury after exposure to NS. The hypothesis of this investigation is that exposure of endothelium to NS would lead to loss of cell membrane integrity, resulting in release of ATP, activation of the purinergic receptor (P2X7R), and subsequent activation of stress activated signaling pathways and inflammation. Human saphenous vein endothelial cells (HSVEC) incubated in NS, but not buffered electrolyte solution (Plasma-Lyte, PL), exhibited abnormal morphology and increased release of lactate dehydrogenase (LDH), adenosine triphosphate (ATP), and decreased transendothelial resistance (TEER), suggesting loss of membrane integrity. Incubation of intact rat aorta (RA) or human saphenous vein in NS but not PL led to impaired endothelial-dependent relaxation which was ameliorated by apyrase (hydrolyzes ATP) or SB203580 (p38 MAPK inhibitor). Exposure of HSVEC to NS but not PL led to activation of p38 MAPK and its downstream substrate, MAPKAP kinase 2 (MK2). Treatment of HSVEC with exogenous ATP led to interleukin 1β (IL-1β) release and increased vascular cell adhesion molecule (VCAM) expression. Treatment of RA with IL-1β led to impaired endothelial relaxation. IL-1β treatment of HSVEC led to increases in p38 MAPK and MK2 phosphorylation, and increased levels of arginase II. Incubation of porcine saphenous vein (PSV) in PL with pH adjusted to 6.0 or less also led to impaired endothelial function, suggesting that the acidic nature of NS is what contributes to endothelial dysfunction. Volume overload resuscitation in a porcine model after hemorrhage with NS, but not PL, led to acidosis and impaired endothelial function. These data suggest that endothelial dysfunction caused by exposure to acidic, non-buffered NS is associated with loss of membrane integrity, release of ATP, and is modulated by P2X7R-mediated inflammatory responses.
0 Communities
1 Members
0 Resources
17 MeSH Terms
Toll-like receptor 3-mediated inflammation by p38 is enhanced by endothelial nitric oxide synthase knockdown.
Koch SR, Choi H, Mace EH, Stark RJ
(2019) Cell Commun Signal 17: 33
MeSH Terms: Capillary Permeability, Cells, Cultured, Chemokine CXCL10, Endothelium, Vascular, Gene Knockdown Techniques, Humans, Inflammation, Interleukin-6, Interleukin-8, Nitric Oxide Synthase Type III, Poly I-C, RNA, Small Interfering, Toll-Like Receptor 3, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added April 17, 2019
BACKGROUND - Vascular dysfunction is commonly seen during severe viral infections. Endothelial nitric oxide synthase (eNOS), has been postulated to play an important role in regulating vascular homeostasis as well as propagation of the inflammatory reaction. We hypothesized that the loss of eNOS would negatively impact toll-like receptor 3 (TLR3) signaling and worsen vascular function to viral challenge.
METHODS - Human microvascular endothelial cells (HMVECs) were exposed to either control or eNOS siRNA and then treated with Poly I:C, a TLR3 agonist and mimicker of dsRNA viruses. Cells were assessed for protein-protein associations, cytokine and chemokine analysis as well as transendothelial electrical resistance (TEER) as a surrogate of permeability.
RESULTS - HMVECs that had reduced eNOS expression had a significantly elevated increase in IL-6, IL-8 and IP-10 production after Poly I:C. In addition, the knockdown of eNOS enhanced the change in TEER after Poly I:C stimulation. Western blot analysis showed enhanced phosphorylation of p38 in sieNOS treated cells with Poly I:C compared to siControl cells. Proximity ligation assays further demonstrated direct eNOS-p38 protein-protein interactions. The addition of the p38 inhibitor, SB203580, in eNOS knockdown cells reduced both cytokine production after Poly I:C, and as well as mitigated the reduction in TEER, suggesting a direct link between eNOS and p38 in TLR3 signaling.
CONCLUSIONS - These results suggest that reduction of eNOS increases TLR3-mediated inflammation in human endothelial cells in a p38-dependent manner. This finding has important implications for understanding the pathogenesis of severe viral infections and the associated vascular dysfunction.
0 Communities
1 Members
0 Resources
14 MeSH Terms
Activation of Nrf2 attenuates delayed gastric emptying in obesity induced diabetic (T2DM) female mice.
Sampath C, Sprouse JC, Freeman ML, Gangula PR
(2019) Free Radic Biol Med 135: 132-143
MeSH Terms: Acrolein, Animals, Antioxidants, Diabetes Complications, Diabetes Mellitus, Type 2, Diet, High-Fat, Gastric Emptying, Gastroparesis, Humans, MAP Kinase Signaling System, Mice, Muscle Relaxation, NF-E2-Related Factor 2, Nitric Oxide Synthase Type I, Obesity, Stomach, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added March 3, 2020
Diabetic gastroparesis (GP) is a clinical syndrome characterized by delayed gastric emptying (DGE). Loss of Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) led to reduced nNOSα mediated gastric motility and DGE. The molecular signaling of cinnamaldehyde (CNM) mediated Nrf2 activation and its mechanistic role on DGE were further investigated in obese/T2D female mice. Adult female homozygous Nfe2l2 (C57BL/6J) and their wild-type (WT) littermates (Nfe2l2) mice were fed with high fat diet (HFD; Obese/T2D model), or normal diet (ND) with or without CNM (50 mg/kg b.w; i.p). Supplementation of CNM attenuated (p < 0.05) DGE in WT female but not in Nrf2 KO Obese/T2D mice. CNM (1) normalized serum estradiol-17β levels, (2) induced gastric Nrf2 and phase II antioxidant enzymes through extracellular signal-regulated kinase, (ERK)/c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinase (MAPK), (3) reduced glucose synthase kinase 3 beta (GSK3β) and aryl hydrocarbon receptor (AhR) and this was associated with (4) increased estrogen receptor expression, BH (Cofactor of nNOS) biosynthesis enzyme GCH-1 and nNOSα dimerization in WT Obese/T2 diabetic female mice. In addition, CNM restored impaired nitrergic relaxation in hyperglycemic conditions. These findings emphasize the importance of Nrf2 in maintaining nNOSα mediated GE and may have a translational relevance to treat obese/diabetic gastroparesis in women.
Copyright © 2019. Published by Elsevier Inc.
0 Communities
1 Members
0 Resources
17 MeSH Terms
Heterologous phosphorylation-induced formation of a stability lock permits regulation of inactive receptors by β-arrestins.
Tóth AD, Prokop S, Gyombolai P, Várnai P, Balla A, Gurevich VV, Hunyady L, Turu G
(2018) J Biol Chem 293: 876-892
MeSH Terms: Angiotensin II, Animals, COS Cells, Chlorocebus aethiops, HEK293 Cells, Humans, Immunoblotting, Microscopy, Confocal, Mitogen-Activated Protein Kinases, Phosphorylation, Receptors, G-Protein-Coupled, beta-Arrestins
Show Abstract · Added March 14, 2018
β-Arrestins are key regulators and signal transducers of G protein-coupled receptors (GPCRs). The interaction between receptors and β-arrestins is generally believed to require both receptor activity and phosphorylation by GPCR kinases. In this study, we investigated whether β-arrestins are able to bind second messenger kinase-phosphorylated, but inactive receptors as well. Because heterologous phosphorylation is a common phenomenon among GPCRs, this mode of β-arrestin activation may represent a novel mechanism of signal transduction and receptor cross-talk. Here we demonstrate that activation of protein kinase C (PKC) by phorbol myristate acetate, G-coupled GPCR, or epidermal growth factor receptor stimulation promotes β-arrestin2 recruitment to unliganded AT angiotensin receptor (ATR). We found that this interaction depends on the stability lock, a structure responsible for the sustained binding between GPCRs and β-arrestins, formed by phosphorylated serine-threonine clusters in the receptor's C terminus and two conserved phosphate-binding lysines in the β-arrestin2 N-domain. Using improved FlAsH-based serine-threonine clusters β-arrestin2 conformational biosensors, we also show that the stability lock not only stabilizes the receptor-β-arrestin interaction, but also governs the structural rearrangements within β-arrestins. Furthermore, we found that β-arrestin2 binds to PKC-phosphorylated ATR in a distinct active conformation, which triggers MAPK recruitment and receptor internalization. Our results provide new insights into the activation of β-arrestins and reveal their novel role in receptor cross-talk.
© 2018 by The American Society for Biochemistry and Molecular Biology, Inc.
0 Communities
1 Members
0 Resources
12 MeSH Terms
Vascular surgical stretch injury leads to activation of P2X7 receptors and impaired endothelial function.
Komalavilas P, Luo W, Guth CM, Jolayemi O, Bartelson RI, Cheung-Flynn J, Brophy CM
(2017) PLoS One 12: e0188069
MeSH Terms: Animals, Endothelium, Vascular, Female, Nitric Oxide, Phosphorylation, Rats, Rats, Sprague-Dawley, Receptors, Purinergic P2X7, Vascular Surgical Procedures, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added May 22, 2018
A viable vascular endothelial layer prevents vasomotor dysfunction, thrombosis, inflammation, and intimal hyperplasia. Injury to the endothelium occurs during harvest and "back table" preparation of human saphenous vein prior to implantation as an arterial bypass conduit. A subfailure overstretch model of rat aorta was used to show that subfailure stretch injury of vascular tissue leads to impaired endothelial-dependent relaxation. Stretch-induced impaired relaxation was mitigated by treatment with purinergic P2X7 receptor (P2X7R) inhibitors, brilliant blue FCF (FCF) and A740003, or apyrase, an enzyme that catalyzes the hydrolysis of ATP. Alternatively, treatment of rat aorta with exogenous ATP or 2'(3')-O-(4-Benzoyl benzoyl)-ATP (BzATP) also impaired endothelial-dependent relaxation. Treatment of human saphenous vein endothelial cells (HSVEC) with exogenous ATP led to reduced nitric oxide production which was associated with increased phosphorylation of the stress activated protein kinase, p38 MAPK. ATP- stimulated p38 MAPK phosphorylation of HSVEC was inhibited by FCF and SB203580. Moreover, ATP inhibition of nitric oxide production in HSVEC was prevented by FCF, SB203580, L-arginine supplementation and arginase inhibition. Finally, L-arginine supplementation and arginase inhibition restored endothelial dependent relaxation after stretch injury of rat aorta. These results suggest that vascular stretch injury leads to ATP release, activation of P2X7R and p38 MAPK resulting in endothelial dysfunction due to arginase activation. Endothelial function can be restored in both ATP treated HSVEC and intact stretch injured rat aorta by P2X7 receptor inhibition with FCF or L-arginine supplementation, implicating straightforward therapeutic options for treatment of surgical vascular injury.
0 Communities
1 Members
0 Resources
MeSH Terms
Endothelial nitric oxide synthase modulates Toll-like receptor 4-mediated IL-6 production and permeability via nitric oxide-independent signaling.
Stark RJ, Koch SR, Choi H, Mace EH, Dikalov SI, Sherwood ER, Lamb FS
(2018) FASEB J 32: 945-956
MeSH Terms: Capillary Permeability, Cells, Cultured, Chronic Disease, Endothelial Cells, Gene Expression Regulation, Enzymologic, Humans, Imidazoles, Interleukin-6, Lipopolysaccharides, MAP Kinase Signaling System, Nitric Oxide, Nitric Oxide Synthase Type III, Pyridines, Toll-Like Receptor 4, Vasculitis, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added October 27, 2017
Endothelial dysfunction, characterized by changes in eNOS, is a common finding in chronic inflammatory vascular diseases. These states are associated with increased infectious complications. We hypothesized that alterations in eNOS would enhance the response to LPS-mediated TLR4 inflammation. Human microvascular endothelial cells were treated with sepiapterin or N-nitro-L-arginine methylester (L-NAME) to alter endogenous NO production, and small interfering RNA to knockdown eNOS. Alterations of endogenous NO by sepiapterin, and L-NAME provided no significant changes to LPS inflammation. In contrast, eNOS knockdown greatly enhanced endothelial IL-6 production and permeability in response to LPS. Knockdown of eNOS enhanced LPS-induced p38. Inhibition of p38 with SB203580 prevented IL-6 production, without altering permeability. Knockdown of p38 impaired NF-κB activation. Physical interaction between p38 and eNOS was demonstrated by immunoprecipitation, suggesting a novel, NO-independent mechanism for eNOS regulation of TLR4. In correlation, biopsy samples in patients with systemic lupus erythematous showed reduced eNOS expression with associated elevations in TLR4 and p38, suggesting an in vivo link. Thus, reduced expression of eNOS, as seen in chronic inflammatory disease, was associated with enhanced TLR4 signaling through p38. This may enhance the response to infection in patients with chronic inflammatory conditions.-Stark, R. J., Koch, S. R., Choi, H., Mace, E. H., Dikalov, S. I., Sherwood, E. R., Lamb, F. S. Endothelial nitric oxide synthase modulates Toll-like receptor 4-mediated IL-6 production and permeability via nitric oxide-independent signaling.
0 Communities
3 Members
0 Resources
16 MeSH Terms
Adenosine triphosphate as a molecular mediator of the vascular response to injury.
Guth CM, Luo W, Jolayemi O, Chadalavada KS, Komalavilas P, Cheung-Flynn J, Brophy CM
(2017) J Surg Res 216: 80-86
MeSH Terms: Adenosine Triphosphate, Animals, Aorta, Abdominal, Biomarkers, Biomechanical Phenomena, Blotting, Western, Female, Muscle Contraction, Rats, Rats, Sprague-Dawley, Receptors, Purinergic P2X7, Stress, Mechanical, Vascular System Injuries, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added May 22, 2018
BACKGROUND - Human saphenous veins used for arterial bypass undergo stretch injury at the time of harvest and preimplant preparation. Vascular injury promotes intimal hyperplasia, the leading cause of graft failure, but the molecular events leading to this response are largely unknown. This study investigated adenosine triphosphate (ATP) as a potential molecular mediator in the vascular response to stretch injury, and the downstream effects of the purinergic receptor, P2X7R, and p38 MAPK activation.
MATERIALS AND METHODS - A subfailure stretch rat aorta model was used to determine the effect of stretch injury on release of ATP and vasomotor responses. Stretch-injured tissues were treated with apyrase, the P2X7R antagonist, A438079, or the p38 MAPK inhibitor, SB203580, and subsequent contractile forces were measured using a muscle bath. An exogenous ATP (eATP) injury model was developed and the experiment repeated. Change in p38 MAPK phosphorylation after stretch and eATP tissue injury was determined using Western blotting. Noninjured tissue was incubated in the p38 MAPK activator, anisomycin, and subsequent contractile function and p38 MAPK phosphorylation were analyzed.
RESULTS - Stretch injury was associated with release of ATP. Contractile function was decreased in tissue subjected to subfailure stretch, eATP, and anisomycin. Contractile function was restored by apyrase, P2X7R antagonism, and p38-MAPK inhibition. Stretch, eATP, and anisomycin-injured tissue demonstrated increased phosphorylation of p38 MAPK.
CONCLUSIONS - Taken together, these data suggest that the vascular response to stretch injury is associated with release of ATP and activation of the P2X7R/P38 MAPK pathway, resulting in contractile dysfunction. Modulation of this pathway in vein grafts after harvest and before implantation may reduce the vascular response to injury.
Copyright © 2017 Elsevier Inc. All rights reserved.
0 Communities
1 Members
0 Resources
MeSH Terms
Molecular dissection of effector mechanisms of RAS-mediated resistance to anti-EGFR antibody therapy.
Kasper S, Reis H, Ziegler S, Nothdurft S, Mueller A, Goetz M, Wiesweg M, Phasue J, Ting S, Wieczorek S, Even A, Worm K, Pogorzelski M, Breitenbuecher S, Meiler J, Paul A, Trarbach T, Schmid KW, Breitenbuecher F, Schuler M
(2017) Oncotarget 8: 45898-45917
MeSH Terms: Antineoplastic Agents, Immunological, Apoptosis, Biomarkers, Cell Line, Tumor, Colorectal Neoplasms, Drug Resistance, Neoplasm, ErbB Receptors, Exons, Genes, ras, Humans, Mitogen-Activated Protein Kinases, Mutation, Odds Ratio, Phosphatidylinositol 3-Kinases, Proto-Oncogene Proteins c-akt, Proto-Oncogene Proteins c-bcl-2, Signal Transduction
Show Abstract · Added March 17, 2018
Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR), cetuximab and panitumumab, are a mainstay of metastatic colorectal cancer (mCRC) treatment. However, a significant number of patients suffer from primary or acquired resistance. RAS mutations are negative predictors of clinical efficacy of anti-EGFR antibodies in patients with mCRC. Oncogenic RAS activates the MAPK and PI3K/AKT pathways, which are considered the main effectors of resistance. However, the relative impact of these pathways in RAS-mutant CRC is less defined. A better mechanistic understanding of RAS-mediated resistance may guide development of rational intervention strategies. To this end we developed cancer models for functional dissection of resistance to anti-EGFR therapy in vitro and in vivo. To selectively activate MAPK- or AKT-signaling we expressed conditionally activatable RAF-1 and AKT in cancer cells. We found that either pathway independently protected sensitive cancer models against anti-EGFR antibody treatment in vitro and in vivo. RAF-1- and AKT-mediated resistance was associated with increased expression of anti-apoptotic BCL-2 proteins. Biomarkers of MAPK and PI3K/AKT pathway activation correlated with inferior outcome in a cohort of mCRC patients receiving cetuximab-based therapy. Dual pharmacologic inhibition of PI3K and MEK successfully sensitized primary resistant CRC models to anti-EGFR therapy. In conclusion, combined targeting of MAPK and PI3K/AKT signaling, but not single pathways, may be required to enhance the efficacy of anti-EGFR antibody therapy in patients with RAS-mutated CRC as well as in RAS wild type tumors with clinical resistance.
0 Communities
1 Members
0 Resources
17 MeSH Terms
Patient-Specific iPSC-Derived Endothelial Cells Uncover Pathways that Protect against Pulmonary Hypertension in BMPR2 Mutation Carriers.
Gu M, Shao NY, Sa S, Li D, Termglinchan V, Ameen M, Karakikes I, Sosa G, Grubert F, Lee J, Cao A, Taylor S, Ma Y, Zhao Z, Chappell J, Hamid R, Austin ED, Gold JD, Wu JC, Snyder MP, Rabinovitch M
(2017) Cell Stem Cell 20: 490-504.e5
MeSH Terms: Base Sequence, Bone Morphogenetic Protein 4, Bone Morphogenetic Protein Receptors, Type II, Cell Adhesion, Cell Movement, Cell Shape, Cell Survival, Endothelial Cells, Gene Editing, Gene Expression Regulation, Heterozygote, Humans, Hypertension, Pulmonary, Induced Pluripotent Stem Cells, Mutation, Neovascularization, Physiologic, Phosphorylation, Sequence Analysis, RNA, Signal Transduction, Smad Proteins, p38 Mitogen-Activated Protein Kinases
Show Abstract · Added February 21, 2017
In familial pulmonary arterial hypertension (FPAH), the autosomal dominant disease-causing BMPR2 mutation is only 20% penetrant, suggesting that genetic variation provides modifiers that alleviate the disease. Here, we used comparison of induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) from three families with unaffected mutation carriers (UMCs), FPAH patients, and gender-matched controls to investigate this variation. Our analysis identified features of UMC iPSC-ECs related to modifiers of BMPR2 signaling or to differentially expressed genes. FPAH-iPSC-ECs showed reduced adhesion, survival, migration, and angiogenesis compared to UMC-iPSC-ECs and control cells. The "rescued" phenotype of UMC cells was related to an increase in specific BMPR2 activators and/or a reduction in inhibitors, and the improved cell adhesion could be attributed to preservation of related signaling. The improved survival was related to increased BIRC3 and was independent of BMPR2. Our findings therefore highlight protective modifiers for FPAH that could help inform development of future treatment strategies.
Copyright © 2017 Elsevier Inc. All rights reserved.
0 Communities
1 Members
0 Resources
21 MeSH Terms