Medicine and Health Sciences Commons^™

Detrimental Effects Of Pcsk9 Loss-Of-Function In The Pediatric Host Response To Sepsis Are Mediated Through Independent Influence On Angiopoietin-1., Mihir R. Atreya, Natalie Z. Cvijanovich, Julie C. Fitzgerald, Scott L. Weiss, Michael T. Bigham, Parag N. Jain, Adam J. Schwarz, Riad Lutfi, Jeffrey Nowak, Geoffrey L. Allen, Neal J. Thomas, Jocelyn R. Grunwell, Torrey Baines, Michael Quasney, Bereketeab Haileselassie, Matthew N. Alder, Patrick Lahni, Scarlett Ripberger, Adesuwa Ekunwe, Kyle R. Campbell, Keith R. Walley, Stephen W. Standage

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Sepsis is associated with significant mortality. Yet, there are no efficacious therapies beyond antibiotics. PCSK9 loss-of-function (LOF) and inhibition, through enhanced low-density lipoprotein receptor (LDLR) mediated endotoxin clearance, holds promise as a potential therapeutic approach among adults. In contrast, we have previously demonstrated higher mortality in the juvenile host. Given the potential pleiotropic effects of PCSK9 on the endothelium, beyond canonical effects on serum lipoproteins, both of which may influence sepsis outcomes, we sought to test the influence of PCSK9 LOF genotype on endothelial dysfunction.

METHODS: Secondary analyses of a prospective observational cohort of pediatric septic shock. Genetic variants …

X-Linked Variations In Shroom4 Are Implicated In Congenital Anomalies Of The Urinary Tract And The Anorectal, Cardiovascular And Central Nervous Systems, Caroline M. Kolvenbach, Tim Felger, Luca Schierbaum, Isabelle Thiffault, T Pastinen, Maria Szczepańska, Marcin Zaniew, Piotr Adamczyk, Allan Bayat, Öznur Yilmaz, Tobias T. Lindenberg, Holger Thiele, Friedhelm Hildebrandt, Katrin Hinderhofer, Ute Moog, Alina C Hilger, Bonnie Sullivan, Lauren E. Bartik, Piotr Gnyś, Phillip Grote, Benjamin Odermatt, Heiko M. Reutter, Gabriel C. Dworschak

Manuscripts, Articles, Book Chapters and Other Papers

Background: SHROOM4 is thought to play an important role in cytoskeletal modification and development of the early nervous system. Previously, single-nucleotide variants (SNVs) or copy number variations (CNVs) in SHROOM4 have been associated with the neurodevelopmental disorder Stocco dos Santos syndrome, but not with congenital anomalies of the urinary tract and the visceral or the cardiovascular system.

Methods: Here, exome sequencing and CNV analyses besides expression studies in zebrafish and mouse and knockdown (KD) experiments using a splice blocking morpholino in zebrafish were performed to study the role of SHROOM4 during embryonic development.

Results: In this study, we identified putative …

Rare Variants In Kdr, Encoding Vegf Receptor 2, Are Associated With Tetralogy Of Fallot., Doris Škorić-Milosavljević, Najim Lahrouchi, Fernanda M. Bosada, Gregor Dombrowsky, Simon G. Williams, Robert Lesurf, Fleur V Y Tjong, Roddy Walsh, Ihssane El Bouchikhi, Jeroen Breckpot, Enrique Audain, Aho Ilgun, Leander Beekman, Ilham Ratbi, Alanna Strong, Maximilian Muenke, Solveig Heide, Alison M. Muir, Mariam Hababa, Laura A. Cross, Dihong Zhou, T Pastinen, German Competence Network For Congenital Heart Defects, Elaine Zackai, Samir Atmani, Karim Ouldim, Najlae Adadi, Katharina Steindl, Anita Rauch, David Brook, Anna Wilsdon, Irene Kuipers, Nico A. Blom, Barbara J. Mulder, Heather C. Mefford, Boris Keren, Pascal Joset, Paul Kruszka, Isabelle Thiffault, Sarah E. Sheppard, Amy Roberts, Elisabeth M. Lodder, Bernard D. Keavney, Sally-Ann B. Clur, Seema Mital, Marc-Philip Hitz, Vincent M. Christoffels, Alex V. Postma, Connie R. Bezzina

Manuscripts, Articles, Book Chapters and Other Papers

Purpose: Rare genetic variants in KDR, encoding the vascular endothelial growth factor receptor 2 (VEGFR2), have been reported in patients with tetralogy of Fallot (TOF). However, their role in disease causality and pathogenesis remains unclear.

Methods: We conducted exome sequencing in a familial case of TOF and large-scale genetic studies, including burden testing, in >1,500 patients with TOF. We studied gene-targeted mice and conducted cell-based assays to explore the role of KDR genetic variation in the etiology of TOF.

Results: Exome sequencing in a family with two siblings affected by TOF revealed biallelic missense variants in KDR. Studies in knock-in …

Immune Checkpoint Modulation Enhances Hiv-1 Antibody Induction., Todd Bradley, Masayuki Kuraoka, Chen-Hao Yeh, Ming Tian, Huan Chen, Derek W Cain, Xuejun Chen, Cheng Cheng, Ali H Ellebedy, Robert Parks, Maggie Barr, Laura L. Sutherland, Richard M. Scearce, Cindy M. Bowman, Hilary Bouton-Verville, Sampa Santra, Kevin Wiehe, Mark G. Lewis, Ane Ogbe, Persephone Borrow, David Montefiori, Mattia Bonsignori, M Anthony Moody, Laurent Verkoczy, Kevin O. Saunders, Rafi Ahmed, John R. Mascola, Garnett Kelsoe, Frederick W. Alt, Barton F. Haynes

Manuscripts, Articles, Book Chapters and Other Papers

Eliciting protective titers of HIV-1 broadly neutralizing antibodies (bnAbs) is a goal of HIV-1 vaccine development, but current vaccine strategies have yet to induce bnAbs in humans. Many bnAbs isolated from HIV-1-infected individuals are encoded by immunoglobulin gene rearrangments with infrequent naive B cell precursors and with unusual genetic features that may be subject to host regulatory control. Here, we administer antibodies targeting immune cell regulatory receptors CTLA-4, PD-1 or OX40 along with HIV envelope (Env) vaccines to rhesus macaques and bnAb immunoglobulin knock-in (KI) mice expressing diverse precursors of CD4 binding site HIV-1 bnAbs. CTLA-4 blockade augments HIV-1 Env …

Deficient Histone H3 Propionylation By Brpf1-Kat6 Complexes In Neurodevelopmental Disorders And Cancer., Kezhi Yan, Justine Rousseau, Keren Machol, Laura A. Cross, Katherine E. Agre, Cynthia Forster Gibson, Anne Goverde, Kendra Engleman, Hannah Verdin, Elfride De Baere, Lorraine Potocki, Dihong Zhou, Maxime Cadieux-Dion, Gary A. Bellus, Monisa D. Wagner, Rebecca J. Hale, Natacha Esber, Alan F. Riley, Benjamin D. Solomon, Megan T. Cho, Kirsty Mcwalter, Roy Eyal, Meagan K. Hainlen, Bryce A. Mendelsohn, Hillary M. Porter, Brendan C. Lanpher, Andrea M. Lewis, Juliann Savatt, Isabelle Thiffault, Bert Callewaert, Philippe M. Campeau, Xiang-Jiao Yang

Manuscripts, Articles, Book Chapters and Other Papers

Lysine acetyltransferase 6A (KAT6A) and its paralog KAT6B form stoichiometric complexes with bromodomain- and PHD finger-containing protein 1 (BRPF1) for acetylation of histone H3 at lysine 23 (H3K23). We report that these complexes also catalyze H3K23 propionylation in vitro and in vivo. Immunofluorescence microscopy and ATAC-See revealed the association of this modification with active chromatin. Brpf1 deletion obliterates the acylation in mouse embryos and fibroblasts. Moreover, we identify BRPF1 variants in 12 previously unidentified cases of syndromic intellectual disability and demonstrate that these cases and known BRPF1 variants impair H3K23 propionylation. Cardiac anomalies are present in a subset of the …

Sirna Targeting And Treatment Of Gastrointestinal Diseases., Rachel Chevalier

Manuscripts, Articles, Book Chapters and Other Papers

RNA interference via small interfering RNA (siRNA) offers opportunities to precisely target genes that contribute to gastrointestinal (GI) pathologies, such as inflammatory bowel disease, celiac, and esophageal scarring. Delivering the siRNA to the GI tract proves challenging as the harsh environment of the intestines degrades the siRNA before it can reach its target or blocks its entry into its site of action in the cytoplasm. Additionally, the GI tract is large and disease is often localized to a specific site. This review discusses polymer and lipid-based delivery systems for protection and targeting of siRNA therapies to the GI tract to …

Altered Detrusor Contractility And Voiding Patterns In Mice Lacking The Mechanosensitive Trek-1 Channel., Ricardo H. Pineda, Joseph Hypolite, Sanghee Lee, Alonso Carrasco, Nao Iguchi, Randall B. Meacham, Anna P. Malykhina

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Previously published results from our laboratory identified a mechano-gated two-pore domain potassium channel, TREK-1, as a main mechanosensor in the smooth muscle of the human urinary bladder. One of the limitations of in vitro experiments on isolated human detrusor included inability to evaluate in vivo effects of TREK-1 on voiding function, as the channel is also expressed in the nervous system, and may modulate micturition via neural pathways. Therefore, in the present study, we aimed to assess the role of TREK-1 channel in bladder function and voiding patterns in vivo by using TREK-1 knockout (KO) mice.

METHODS: Adult C57BL/6 …

H3k27m Induces Defective Chromatin Spread Of Prc2-Mediated Repressive H3k27me2/Me3 And Is Essential For Glioma Tumorigenesis., Ashot S. Harutyunyan, Brian Krug, Haifen Chen, Simon Papillon-Cavanagh, Michele Zeinieh, Nicolas De Jay, Shriya Deshmukh, Carol C L Chen, Jad Belle, Leonie G. Mikael, Dylan M. Marchione, Rui Li, Hamid Nikbakht, Bo Hu, Gael Cagnone, Warren A. Cheung, Abdulshakour Mohammadnia, Denise Bechet, Damien Faury, Melissa K. Mcconechy, Manav Pathania, Siddhant U. Jain, Benjamin Ellezam, Alexander G. Weil, Alexandre Montpetit, Paolo Salomoni, Tomi Pastinen, Chao Lu, Peter W. Lewis, Benjamin A. Garcia, Claudia L. Kleinman, Nada Jabado, Jacek Majewski

Manuscripts, Articles, Book Chapters and Other Papers

Lys-27-Met mutations in histone 3 genes (H3K27M) characterize a subgroup of deadly gliomas and decrease genome-wide H3K27 trimethylation. Here we use primary H3K27M tumor lines and isogenic CRISPR-edited controls to assess H3K27M effects in vitro and in vivo. We find that whereas H3K27me3 and H3K27me2 are normally deposited by PRC2 across broad regions, their deposition is severely reduced in H3.3K27M cells. H3K27me3 is unable to spread from large unmethylated CpG islands, while H3K27me2 can be deposited outside these PRC2 high-affinity sites but to levels corresponding to H3K27me3 deposition in wild-type cells. Our findings indicate that PRC2 recruitment and propagation on …

Clinical Pharmacology Of Tisagenlecleucel In B-Cell Acute Lymphoblastic Leukemia., Karen Thudium Mueller, Edward Waldron, Stephan A. Grupp, John E. Levine, Theodore W. Laetsch, Michael A. Pulsipher, Michael W. Boyer, Keith August, Jason Hamilton, Rakesh Awasthi, Andrew M. Stein, Denise Sickert, Abhijit Chakraborty, Bruce L. Levine, Carl H. June, Lori Tomassian, Sweta S. Shah, Mimi Leung, Tetiana Taran, Patricia A. Wood, Shannon L. Maude

Manuscripts, Articles, Book Chapters and Other Papers

PURPOSE: Tisagenlecleucel is an anti-CD19 chimeric antigen receptor (CAR19) T-cell therapy approved for the treatment of children and young adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL).

PATIENTS AND METHODS: We evaluated the cellular kinetics of tisagenlecleucel, the effect of patient factors, humoral immunogenicity, and manufacturing attributes on its kinetics, and exposure-response analysis for efficacy, safety and pharmacodynamic endpoints in 79 patients across two studies in pediatric B-ALL (ELIANA and ENSIGN).

RESULTS: Using quantitative polymerase chain reaction to quantify levels of tisagenlecleucel transgene, responders (N = 62) had ≈2-fold higher tisagenlecleucel expansion in peripheral blood than nonresponders ( …

Enteric Infection Coupled With Chronic Notch Pathway Inhibition Alters Colonic Mucus Composition Leading To Dysbiosis, Barrier Disruption And Colitis., Ishfaq Ahmed, Badal C. Roy, Rita-Marie T. Raach, Sarah M. Owens, Lijun Xia, Shrikant Anant, Venkatesh Sampath, Shahid Umar

Manuscripts, Articles, Book Chapters and Other Papers

Intestinal mucus layer disruption and gut microflora modification in conjunction with tight junction (TJ) changes can increase colonic permeability that allows bacterial dissemination and intestinal and systemic disease. We showed previously that Citrobacter rodentium (CR)-induced colonic crypt hyperplasia and/or colitis is regulated by a functional cross-talk between the Notch and Wnt/β-catenin pathways. In the current study, mucus analysis in the colons of CR-infected (108 CFUs) and Notch blocker Dibenzazepine (DBZ, i.p.; 10μmol/Kg b.w.)-treated mice revealed significant alterations in the composition of trace O-glycans and complex type and hybrid N-glycans, compared to CR-infected mice alone that preceded/accompanied alterations in 16S rDNA …

Trpv1 And The Mcp-1/Ccr2 Axis Modulate Post-Uti Chronic Pain., John Rosen, Ryan E. Yaggie, Patrick J. Woida, Richard J. Miller, Anthony J. Schaeffer, David J. Klumpp

Manuscripts, Articles, Book Chapters and Other Papers

The etiology of chronic pelvic pain syndromes remains unknown. In a murine urinary tract infection (UTI) model, lipopolysaccharide of uropathogenic E. coli and its receptor TLR4 are required for post-UTI chronic pain development. However, downstream mechanisms of post-UTI chronic pelvic pain remain unclear. Because the TRPV1 and MCP-1/CCR2 pathways are implicated in chronic neuropathic pain, we explored their role in post-UTI chronic pain. Mice were infected with the E. coli strain SΦ874, known to produce chronic allodynia, and treated with the TRPV1 antagonist capsazepine. Mice treated with capsazepine at the time of SΦ874 infection failed to develop chronic allodynia, whereas …

Mechanotransduction Signaling In Podocytes From Fluid Flow Shear Stress., Tarak Srivastava, Hongying Dai, Daniel P. Heruth, Uri S. Alon, Robert E. Garola, Jianping Zhou, R Scott Duncan, Ashraf El-Meanawy, Ellen T. Mccarthy, Ram Sharma, Mark L. Johnson, Virginia J. Savin, Mukut Sharma

Manuscripts, Articles, Book Chapters and Other Papers

Recently, we and others have found that hyperfiltration-associated increase in biomechanical forces, namely, tensile stress and fluid flow shear stress (FFSS), can directly and distinctly alter podocyte structure and function. The ultrafiltrate flow over the major processes and cell body generates FFSS to podocytes. Our previous work suggests that the cyclooxygenase-2 (COX-2)-PGE2-PGE2 receptor 2 (EP2) axis plays an important role in mechanoperception of FFSS in podocytes. To address mechanotransduction of the perceived stimulus through EP2, cultured podocytes were exposed to FFSS (2 dyn/cm2) for 2 h. Total RNA from cells at the end of FFSS treatment, 2-h post-FFSS, and 24-h …

Nicotinamide Phosphoribosyltransferase Promotes Pulmonary Vascular Remodeling And Is A Therapeutic Target In Pulmonary Arterial Hypertension., Jiwang Chen, Justin R Sysol, Sunit Singla, Shuangping Zhao, Aya Yamamura, Daniela Valdez-Jasso, Taimur Abbasi, Krystyna M. Shioura, Sakshi Sahni, Vamsi Reddy, Arvind Sridhar, Hui Gao, Jaime Torres, Sara M. Camp, Haiyang Tang, Shui Q. Ye, Suzy Comhair, Raed Dweik, Paul Hassoun, Jason X-J Yuan, Joe G N Garcia, Roberto F. Machado

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Pulmonary arterial hypertension is a severe and progressive disease, a hallmark of which is pulmonary vascular remodeling. Nicotinamide phosphoribosyltransferase (NAMPT) is a cytozyme that regulates intracellular nicotinamide adenine dinucleotide levels and cellular redox state, regulates histone deacetylases, promotes cell proliferation, and inhibits apoptosis. We hypothesized that NAMPT promotes pulmonary vascular remodeling and that inhibition of NAMPT could attenuate pulmonary hypertension.

METHODS: Plasma, mRNA, and protein levels of NAMPT were measured in the lungs and isolated pulmonary artery endothelial cells from patients with pulmonary arterial hypertension and in the lungs of rodent models of pulmonary hypertension.Nampt+/- mice were …

Metabolic And Molecular Insights Into An Essential Role Of Nicotinamide Phosphoribosyltransferase., Li Q. Zhang, Leon Van Haandel, Min Xiong, Peixin Huang, Daniel P. Heruth, Chengpeng Bi, R Gaedigk, Xun Jiang, Ding-You Li, Gerald Wyckoff, Dmitry N. Grigoryev, Li Gao, Linheng Li, Min Wu, J Steven Leeder, Shui Qing Ye

Manuscripts, Articles, Book Chapters and Other Papers

Nicotinamide phosphoribosyltransferase (NAMPT) is a pleiotropic protein implicated in the pathogenesis of acute respiratory distress syndrome, aging, cancer, coronary heart diseases, diabetes, nonalcoholic fatty liver disease, obesity, rheumatoid arthritis, and sepsis. However, the underlying molecular mechanisms of NAMPT in these physiological and pathological processes are not fully understood. Here, we provide experimental evidence that a Nampt gene homozygous knockout (Nampt-/-) resulted in lethality at an early stage of mouse embryonic development and death within 5-10 days in adult mice accompanied by a 25.24±2.22% body weight loss, after the tamoxifen induction of NamptF/F × Cre mice. These results substantiate that Nampt …

Genetic Drivers Of Kidney Defects In The Digeorge Syndrome., Esther Lopez-Rivera, Yangfan P. Liu, Miguel Verbitsky, Blair R. Anderson, Valentina P. Capone, Edgar A. Otto, Zhonghai Yan, Adele Mitrotti, Jeremiah Martino, Nicholas J. Steers, David A. Fasel, Katarina Vukojevic, Rong Deng, Silvia E. Racedo, Qingxue Liu, Max Werth, Rik Westland, Asaf Vivante, Gabriel S. Makar, Monica Bodria, Matthew G. Sampson, Christopher E. Gillies, Virginia Vega-Warner, Mariarosa Maiorana, Donald S. Petrey, Barry Honig, Vladimir J. Lozanovski, Rémi Salomon, Laurence Heidet, Wassila Carpentier, Dominique Gaillard, Alba Carrea, Loreto Gesualdo, Daniele Cusi, Claudia Izzi, Francesco Scolari, Joanna A E Van Wijk, Adela Arapovic, Mirna Saraga-Babic, Marijan Saraga, Nenad Kunac, Ali Samii, Donna M. Mcdonald-Mcginn, Terrence B. Crowley, Elaine H. Zackai, Dorota Drozdz, Monika Miklaszewska, Marcin Tkaczyk, Przemyslaw Sikora, Maria Szczepanska, Malgorzata Mizerska-Wasiak, Grazyna Krzemien, Agnieszka Szmigielska, Marcin Zaniew, John M. Darlow, Prem Puri, David Barton, Emilio Casolari, Susan L. Furth, Bradley A. Warady, Zoran Gucev, Hakon Hakonarson, Hana Flogelova, Velibor Tasic, Anna Latos-Bielenska, Anna Materna-Kiryluk, Landino Allegri, Craig S. Wong, Iain A Drummond, Vivette D'Agati, Akira Imamoto, Jonathan M. Barasch, Friedhelm Hildebrandt, Krzysztof Kiryluk, Richard P. Lifton, Bernice E. Morrow, Cecile Jeanpierre, Virginia E. Papaioannou, Gian Marco Ghiggeri, Ali G. Gharavi, Nicholas Katsanis, Simone Sanna-Cherchi

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The DiGeorge syndrome, the most common of the microdeletion syndromes, affects multiple organs, including the heart, the nervous system, and the kidney. It is caused by deletions on chromosome 22q11.2; the genetic driver of the kidney defects is unknown.

METHODS: We conducted a genomewide search for structural variants in two cohorts: 2080 patients with congenital kidney and urinary tract anomalies and 22,094 controls. We performed exome and targeted resequencing in samples obtained from 586 additional patients with congenital kidney anomalies. We also carried out functional studies using zebrafish and mice.

RESULTS: We identified heterozygous deletions of 22q11.2 in 1.1% …

Mc-Ppea As A New And More Potent Inhibitor Of Clp-Induced Sepsis And Pulmonary Inflammation Than Fk866., Peixin Huang, Mark W Lee, Keivan Sadrerafi, Daniel P. Heruth, Li Q. Zhang, Dev Maulik, Shui Qing Ye

Manuscripts, Articles, Book Chapters and Other Papers

Our previous study indicated that overexpression of nicotinamide phosphoribosyltransferase (NAMPT) aggravated acute lung injury, while knockdown of NAMPT expression attenuated ventilator-induced lung injury. Recently, we found that meta-carborane-butyl-3-(3-pyridinyl)-2E-propenamide (MC-PPEA, MC4), in which the benzoylpiperidine moiety of FK866 has been replaced by a carborane, displayed a 100-fold increase in NAMPT inhibition over FK866. Here, we determined the effects of MC4 and FK866 on cecal ligation and puncture (CLP) surgery-induced sepsis in C57BL/6J mice. MC4 showed stronger inhibitory effects than FK866 on CLP-induced mortality, serum tumor necrosis factor α (TNFα) levels, pulmonary myeloperoxidase activity, alveolar injury, and interleukin 6 and interleukin1β messenger …

Nicotinamide Adenine Dinucleotide Phosphate Oxidase 2 Regulates Lps-Induced Inflammation And Alveolar Remodeling In The Developing Lung., Heather Menden, Sheng Xia, Sherry M. Mabry, Angels Navarro, Michael F. Nyp, Venkatesh Sampath

Manuscripts, Articles, Book Chapters and Other Papers

In premature infants, sepsis is associated with alveolar simplification manifesting as bronchopulmonary dysplasia. The redox-dependent mechanisms underlying sepsis-induced inflammation and alveolar remodeling in the immature lung remain unclear. We developed a neonatal mouse model of sepsis-induced lung injury to investigate whether nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) regulates Toll-like receptor (TLR)-mediated inflammation and alveolar remodeling. Six-day-old NOX2

Renal And Hematological Effects Of Clcf-1, A B-Cell-Stimulating Cytokine Of The Il-6 Family., Virginia J. Savin, Mukut Sharma, Jianping Zhou, David Gennochi, Timothy Fields, Ram Sharma, Ellen T. Mccarthy, Tarak Srivastava, Jos Domen, Aurélie Tormo, Jean-François Gauchat

Manuscripts, Articles, Book Chapters and Other Papers

CLCF-1 is a cytokine known for B-cell stimulation and for neurotrophic properties. We have identified CLCF-1 as a potential injurious factor in the human renal disease focal segmental glomerulosclerosis (FSGS). We investigated its effects on renal cells and renal function in in vitro and in vivo studies. Methods include measurement of the effect of CLCF-1 on phosphorylation of target molecules of the JAK/STAT pathway, on cytoskeleton and cell morphology in cultured podocytes, on albumin permeability of isolated rat glomeruli, and on tissue phosphorylation and urine albumin after acute or chronic CLCF-1 injection. In addition, cell sorting was performed to determine …

Ethanol At Low Concentrations Protects Glomerular Podocytes Through Alcohol Dehydrogenase And 20-Hete., Ellen T. Mccarthy, Jianping Zhou, Ryan Eckert, David Genochio, Rishi Sharma, Olurinde Oni, Alok De, Tarak Srivastava, Ram Sharma, Virginia J. Savin, Mukut Sharma

Manuscripts, Articles, Book Chapters and Other Papers

Clinical studies suggest cardiovascular and renal benefits of ingesting small amounts of ethanol. Effects of ethanol, role of alcohol dehydrogenase (ADH) or of 20-hydroxyeicosatetraenoic acid (20-HETE) in podocytes of the glomerular filtration barrier have not been reported. We found that mouse podocytes at baseline generate 20-HETE and express ADH but not CYP2e1. Ethanol at high concentrations altered the actin cytoskeleton, induced CYP2e1, increased superoxide production and inhibited ADH gene expression. Ethanol at low concentrations upregulated the expression of ADH and CYP4a12a. 20-HETE, an arachidonic acid metabolite generated by CYP4a12a, blocked the ethanol-induced cytoskeletal derangement and superoxide generation. Ethanol at high …

Cyclooxygenase-2, Prostaglandin E2, And Prostanoid Receptor Ep2 In Fluid Flow Shear Stress-Mediated Injury In The Solitary Kidney., Tarak Srivastava, Uri S. Alon, Patricia A. Cudmore, Belal Tarakji, Alexander Kats, Robert E. Garola, R Scott Duncan, Ellen T. Mccarthy, Ram Sharma, Mark L. Johnson, Lynda F. Bonewald, Ashraf El-Meanawy, Virginia J. Savin, Mukut Sharma

Manuscripts, Articles, Book Chapters and Other Papers

Hyperfiltration subjects podocytes to increased tensile stress and fluid flow shear stress (FFSS). We showed a 1.5- to 2.0-fold increase in FFSS in uninephrectomized animals and altered podocyte actin cytoskeleton and increased synthesis of prostaglandin E2 (PGE2) following in vitro application of FFSS. We hypothesized that increased FFSS mediates cellular changes through specific receptors of PGE2. Presently, we studied the effect of FFSS on cultured podocytes and decapsulated isolated glomeruli in vitro, and on solitary kidney in uninephrectomized sv129 mice. In cultured podocytes, FFSS resulted in increased gene and protein expression of cyclooxygenase (COX)-2 but not COX-1, prostanoid receptor EP2 …

Fluid Flow Shear Stress Over Podocytes Is Increased In The Solitary Kidney., Tarak Srivastava, Gianni E. Celsi, Mukut Sharma, Hongying Dai, Ellen T. Mccarthy, Melanie Ruiz, Patricia A. Cudmore, Uri S. Alon, Ram Sharma, Virginia A. Savin

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Glomerular hyperfiltration is emerging as the key risk factor for progression of chronic kidney disease (CKD). Podocytes are exposed to fluid flow shear stress (FFSS) caused by the flow of ultrafiltrate within Bowman's space. The mechanism of hyperfiltration-induced podocyte injury is not clear. We postulated that glomerular hyperfiltration in solitary kidney increases FFSS over podocytes.

METHODS: Infant Sprague-Dawley rats at 5 days of age and C57BL/6J 14-week-old adult mice underwent unilateral nephrectomy. Micropuncture and morphological studies were then performed on 20- and 60-day-old rats. FFSS over podocytes in uninephrectomized rats and mice was calculated using the recently published equation …

Biochemical And Mutational Analysis Of The Histidine Residues Of Staphylococcal Enterotoxin A., M Hoffman, M Tremaine, J Mansfield, M Betley

Manuscripts, Articles, Book Chapters and Other Papers

The goal of this study was to examine the role of histidine residues in the biological activities of staphylococcal enterotoxin A (SEA). Carboxymethylated SEA was unable to stimulate murine T-cell proliferation but was resistant to monkey stomach lavage fluid degradation, suggesting that native conformation was intact. Site-directed mutagenesis of the histidine residues of SEA was subsequently performed. SEA-H44A (SEA with histidine 44 replaced with alanine), SEA-H44D, SEA-H50A, SEA-H50D, SEA-H114A, SEA-H114D, SEA-H187A, and SEA-H187D retained superantigen and emetic activities, whereas SEA-H225A and SEA-H225D were defective in the ability to stimulate T-cell proliferation. These mutants were unable to compete with SEA for …