Principal Investigator: Paul W. Buehler, PhD
Office / Division / Lab: OBRR / DH / LBVB
In order to have sufficient blood to address medical needs, donated blood is stored for up to 42 days. Sometimes the red blood cells in the stored blood will start to disintegrate over time and release free hemoglobin. In addition, there are certain disease states, such as sickle cell disease and malaria, in which red blood cells disintegrate and release hemoglobin.
Our new program in the Laboratory of Biochemisty and Vascular Biology studies how red blood cells disintegrate and release hemoglobin (the oxygen--carrying molecule of red blood cells) and evaluates the toxic effects of this free hemoglobin in the body. This work will help make our blood supply safer by providing new insights into how free hemoglobin causes its toxic effects.. This new knowledge may facilitate development of new ways to reduce or eliminate the risk posed by free hemoglobin released from stored red blood cells and free hemoglobin released during acquired and genetic hemolytic diseases.
The knowledge gained from this work will also support the regulatory review work of FDA and ability of the agency to provide effective guidance to industry in preventing toxic effects of hemoglobin in blood products.
In order to obtain this knowledge we are studying the mechanisms that trigger red blood cell hemolysis, by doing protein and tissue analysis to evaluate toxicity induced by cell-free hemoglobin, and developing appropriate animal models and biomarkers to investigate the underlying hemolysis in transfusion medicine and hemolytic diseases (both acquired and genetic). (A biomarker is a substance that can be measured and used to indicate the state of normal biological processes, diseases, or response to therapy.) This work also includes computer simulation, and when required, animal studies.
Our laboratory is also currently studying the interaction of some protein-based therapeutic products with blood vessels in order to gain insights into the damage this interaction can cause. We are focused primarily on hemoglobin-based oxygen carriers used in "artificial blood," as well as therapies for anthrax and therapeutic proteins obtained from plasma.
The overall objective of our research is to understand the underlying mechanisms of vascular dysfunction induced by therapeutic proteins, to promote the design of safer and more effective therapeutics, and to facilitate the establishment of useful biomarkers.
Our laboratory is currently pursuing biochemical characterization of a number of protein-based products that interact with the vascular system, with a special focus on hemoglobin-based oxygen carriers (HBOCs), some plasma proteins, and anthrax toxin therapies.
We established a program in red cell toxicokinetics and proteomics to evaluate concepts central to hemoglobin toxicity as they relate to red blood cell (RBC) storage in vivo, with a special emphasis on understanding endogenous clearance of free hemoglobin released from aged RBCs. This will provide a strategy for minimizing RBC-induced toxicity in whole animals that could provide insight into human clinical risks.
The scientific approach and aims of this program will:
1) Develop an appropriate animal model to investigate the underlying pathophysiolgic mechanisms of aged RBCs and subsequent hemolysis.
2) Use proteomic analysis of blood and tissue protein modifications as biomarkers of injury caused by extracellular Hb oxidation and degradation arising from RBCs transfusions.
3) Evaluate in vitro mechanisms contributing to the loss of RBC deformability to improve our understanding of the effects of RBC storage on in vitro morphology and in vivo hemolysis.
4) Design protective strategies by enhancing clearance mechanisms of extracellular Hb by either co-administration of natural or synthetic Hb binding proteins/peptides which would allow for longer storage time of blood with reduced risk of adverse events.
Cell Death Dis 2016 Jan 21;7:e2064
Hemoglobinuria-related acute kidney injury is driven by intrarenal oxidative reactions triggering a heme toxicity response.
Deuel JW, Schaer CA, Boretti FS, Opitz L, Garcia-Rubio I, Baek JH, Spahn DR, Buehler PW, Schaer DJ
Free Radic Biol Med 2015 Dec;89:931-43
Different target specificities of haptoglobin and hemopexin define a sequential protection system against vascular hemoglobin toxicity.
Deuel JW, Vallelian F, Schaer CA, Puglia M, Buehler PW, Schaer DJ
Free Radic Biol Med 2015 Aug;85:259-68
Spin trapping combined with quantitative mass spectrometry defines free radical redistribution within the oxidized hemoglobin:haptoglobin complex.
Vallelian F, Garcia-Rubio I, Puglia M, Kahraman A, Deuel JW, Engelsberger WR, Mason RP, Buehler PW, Schaer DJ
Toxicology 2015 Jul 3;333:89-99
Sodium nitrite potentiates renal oxidative stress and injury in hemoglobin exposed guinea pigs.
Baek JH, Zhang X, Williams MC, Hicks W, Buehler PW, Felice D
Haematologica 2015 May;100(5):611-22
Reversal of hemochromatosis by apo-transferrin in non-transfused and transfused Hbbth3/+ (heterozygous b1/ b2 globin gene deletion) mice.
Gelderman MP, Baek JH, Yalamanoglu A, Puglia M, Vallelian F, Burla B, Vostal J, Schaer DJ, Buehler PW
Free Radic Biol Med 2015 May;82:50-62
Hemoglobin induced lung vascular oxidation, inflammation, and remodeling contributes to the progression of hypoxic pulmonary hypertension and is attenuated in rats with repeat dose haptoglobin administration.
Irwin DC, Baek JH, Hassell K, Nuss R, Eigenberger P, Lisk C, Loomis Z, Maltzahn J, Stenmark KR, Nozik-Grayck E, Buehler PW
J Proteome Res 2015 Feb 6;14(2):1089-100
Integrative proteome and transcriptome analysis of extramedullary erythropoiesis and its reversal by transferrin treatment in a mouse model of beta-thalassemia.
Vallelian F, Gelderman MP, Schaer CA, Puglia M, Opitz L, Baek JH, Vostal J, Buehler P, Schaer DJ
Cell Death Differ 2015 Apr;22(4):597-611
Proteasome inhibition and oxidative reactions disrupt cellular homeostasis during heme stress.
Vallelian F, Deuel JW, Opitz L, Schaer CA, Puglia M, Lonn M, Engelsberger W, Schauer S, Karnaukhova E, Spahn DR, Stocker R, Buehler PW, Schaer DJ
Front Physiol 2014 Oct 9;5:385
Modeling hemoglobin and hemoglobin:haptoglobin complex clearance in a non-rodent species-pharmacokinetic and therapeutic implications.
Boretti FS, Baek JH, Palmer AF, Schaer DJ, Buehler PW
Front Physiol 2014 Oct 28;5:415
Haptoglobin, hemopexin, and related defense pathways-basic science, clinical perspectives, and drug development.
Schaer DJ, Vinchi F, Ingoglia G, Tolosano E, Buehler PW
Toxins 2014 Mar 31;6(4):1244-59
Extracellular hb enhances cardiac toxicity in endotoxemic Guinea pigs: protective role of haptoglobin.
Baek JH, Zhang X, Williams MC, Schaer DJ, Buehler PW, D'Agnillo F
Antioxid Redox Signal 2013 Nov 10;19(14):1619-33
Human hp1-1 and hp2-2 phenotype-specific haptoglobin therapeutics are both effective in vitro and in Guinea pigs to attenuate hemoglobin toxicity.
Lipiski M, Deuel JW, Baek JH, Engelsberger WR, Buehler PW, Schaer DJ
Antioxid Redox Signal 2013 Jun 10;18(17):2264-73
Haptoglobin Binding Stabilizes Hemoglobin Ferryl Iron and the Globin Radical on Tyrosine beta145.
Cooper CE, Schaer DJ, Buehler PW, Wilson MT, Reeder BJ, Silkstone G, Svistunenko DA, Bulow L, Alayash AI
Cold Spring Harb Perspect Med 2013 Jun 1;3(6):a013433
Cell-Free Hemoglobin and Its Scavenger Proteins: New Disease Models Leading the Way to Targeted Therapies.
Schaer DJ, Buehler PW
PLoS One 2013;8(3):e59841
Haptoglobin preferentially binds beta but not alpha subunits cross-linked hemoglobin tetramers with minimal effects on ligand and redox reactions.
Jia Y, Wood F, Buehler PW, Alayash AI
Blood 2013 Feb 21;121(8):1276-84
Hemolysis and free hemoglobin revisited: exploring hemoglobin and hemin scavengers as a novel class of therapeutic proteins.
Schaer DJ, Buehler PW, Alayash AI, Belcher JD, Vercellotti GM
Am J Physiol Lung Cell Mol Physiol 2012 Aug;303(4):L312-26
Free hemoglobin induction of pulmonary vascular disease: evidence for an inflammatory mechanism.
Buehler PW, Baek JH, Lisk C, Connor I, Sullivan T, Kominsky DJ, Majka SM, Stenmark KR, Nozik-Grayck E, Bonaventura J, Irwin DC
Toxicol Sci 2012 Jun;127(2):567-81
Down selection of polymerized bovine hemoglobins for use as oxygen releasing therapeutics in a guinea pig model.
Baek JH, Zhou Y, Harris DR, Dominik SJ, Palmer AF, Buehler PW
J Clin Invest 2012 Apr 2;122(4):1444-58
Hemoglobin-driven pathophysiology is an in vivo consequence of the red blood cell storage lesion that can be attenuated in guinea pigs by haptoglobin therapy.
Baek JH, D'Agnillo F, Vallelian F, Pereira CP, Williams MC, Jia Y, Schaer DJ, Buehler PW
Biochem Biophys Res Commun 2011 Dec 16;416(3-4):421-6
Inactivation of prolyl hydroxylase domain (PHD) protein by epigallocatechin (EGCG) stabilizes hypoxia-inducible factor (HIF-1alpha) and induces hepcidin (Hamp) in rat kidney.
Manalo DJ, Baek JH, Buehler PW, Struble E, Abraham B, Alayash AI
Biotechnol Prog 2011 Jul;27(4):1172-84
Synthesis, biophysical properties, and oxygenation potential of variable molecular weight glutaraldehyde-polymerized bovine hemoglobins with low and high oxygen affinity.
Zhou Y, Jia Y, Buehler PW, Chen G, Cabrales P, Palmer AF
Biochem Biophys Res Commun 2011 Jun 10;409(3):412-7
Sodium nitrite induces acute central nervous system toxicity in guinea pigs exposed to systemic cell-free hemoglobin.
Buehler PW, Butt OI, D'Agnillo F
Antioxid Redox Signal 2011 May 1;14(9):1713-28
Blood aging, safety and transfusion: capturing the "radical" menace.
Buehler PW, Karnaukhova E, Gelderman MP, Alayash AI
Biochim Biophys Acta 2011 Apr-Jun;1809(4-6):262-8
Induction of hypoxia inducible factor (HIF-1α) in the rat kidneys by iron chelation with the hydroxypyridinone, CP94.
Baek JH, Reiter CE, Manalo DJ, Buehler PW, Hider RC, Alayash AI
Am J Pathol 2011 Mar;178(3):1316-28
Blood-brain barrier disruption and oxidative stress in Guinea pig after systemic exposure to modified cell-free hemoglobin.
Butt OI, Buehler PW, D'Agnillo F
Trends Mol Med 2010 Aug 12;16(10):447-57
Hemoglobin-based oxygen carriers: from mechanisms of toxicity and clearance to rational drug design.
Buehler PW, D'Agnillo F, Schaer DJ
J Proteome Res 2010 Aug 6;9(8):4061-70
Quantitative mass spectrometry defines an oxidative hotspot in hemoglobin that is specifically protected by haptoglobin.
Pimenova T, Pereira CP, Gehrig P, Buehler PW, Schaer DJ, Zenobi R
Biotechnol Bioeng 2010 May 1;106(1):76-85
Functional comparison of hemoglobin purified by different methods and their biophysical implications.
Elmer J, Buehler PW, Jia Y, Wood F, Harris DR, Alayash AI, Palmer AF
Biomaterials 2010 May;31(13):3723-35
Synthesis, biophysical properties and pharmacokinetics of ultrahigh molecular weight tense and relaxed state polymerized bovine hemoglobins.
Buehler PW, Zhou Y, Cabrales P, Jia Y, Guoyong Sun, Harris DR, Tsai AG, Intaglietta M, Palmer AF
Antioxid Redox Signal 2010 Feb;12(2):185-98
Hemoglobin can attenuate hydrogen peroxide-induced oxidative stress by acting as an antioxidative peroxidase.
Widmer CC, Pereira CP, Gehrig P, Vallelian F, Schoedon G, Buehler PW, Schaer DJ
Am J Respir Cell Mol Biol 2010 Feb;42(2):200-9
Mixed S-nitrosylated polymerized bovine hemoglobin species moderate hemodynamic effects in acutely hypoxic rats.
Irwin D, Buehler PW, Alayash AI, Jia Y, Bonventura J, Foreman B, White M, Jacobs R, Piteo B, TissotvanPatot MC, Hamilton KL, Gotshall RW
Antioxid Redox Signal 2010 Feb;12(2):275-91
Toxicological Consequences of Extracellular Hemoglobin: Biochemical and Physiological Perspectives.
Buehler PW, D'Agnillo F
Antioxid Redox Signal 2010 Feb;12(2):199-208
Differential induction of renal heme oxygenase and ferritin in ascorbate and non-ascorbate producing species transfused with modified cell-free hemoglobin.
Butt OI, Buehler PW, D'Agnillo F
Ann Pharmacother 2009 Oct;43(10):1583-97
Comparing Generic and Innovator Drugs: A Review of 12 Years of Bioequivalence Data from the United States Food and Drug Administration(October).
Davit BM, Nwakama PE, Buehler GJ, Conner DP, Haidar SH, Patel DT, Yang Y, Yu LX, Woodcock J
J Clin Invest 2009 Aug;119(8):2271-80
Sequestration of extracellular hemoglobin within a haptoglobin complex decreases its hypertensive and oxidative effects in dogs and guinea pigs.
Boretti FS, Buehler PW, D'Agnillo F, Kluge K, Glaus T, Butt OI, Jia Y, Goede J, Pereira CP, Maggiorini M, Schoedon G, Alayash AI, Schaer DJ
Blood 2009 Mar 12;113(11):2578-86
Haptoglobin preserves the CD163 hemoglobin scavenger pathway by shielding hemoglobin from peroxidative modification.
Buehler PW, Abraham B, Vallelian F, Linnemayr C, Pereira CP, Cipollo JF, Jia Y, Mikolajczyk M, Boretti FS, Schoedon G, Alayash AI, Schaer DJ
Biochim Biophys Acta 2008 Oct;1784(10):1415-20
Peroxidase activity of hemoglobin towards ascorbate and urate: a synergistic protective strategy against toxicity of Hemoglobin-Based Oxygen Carriers (HBOC).
Cooper CE, Silaghi-Dumitrescu R, Rukengwa M, Alayash AI, Buehler PW
Free Radic Biol Med 2008 Oct 15;45(8):1150-8
The reaction of hydrogen peroxide with hemoglobin induces extensive alpha-globin crosslinking and impairs the interaction of hemoglobin with endogenous scavenger pathways.
Vallelian F, Pimenova T, Pereira CP, Abraham B, Mikolajczyk MG, Schoedon G, Zenobi R, Alayash AI, Buehler PW, Schaer DJ
Biochim Biophys Acta 2008 Oct;1784(10):1378-81
All hemoglobin-based oxygen carriers are not created equally.
Buehler PW, Alayash AI
Biochem J 2008 Sep 15;414(3):461-9
Acellular haemoglobin attenuates hypoxia-inducible factor-1alpha (HIF-1alpha) and its target genes in haemodiluted rats.
Manalo DJ, Buehler PW, Baek JH, Butt O, D'agnillo F, Alayash AI
Antioxid Redox Signal 2008 Aug;10(8):1449-62
Structural stabilization in tetrameric or polymeric hemoglobin determines its interaction with endogenous antioxidant scavenger pathways.
Buehler PW, Vallelian F, Mikolajczyk MG, Schoedon G, Schweizer T, Alayash AI, Schaer DJ
J Pharmacol Exp Ther 2007 Oct;323(1):49-60
Effects of endogenous ascorbate on oxidation, oxygenation and toxicokinetics of cell-free modified hemoglobin after exchange transfusion in rat and guinea pig.
Buehler PW, D'Agnillo F, Hoffman V, Alayash AI
Antioxid Redox Signal 2007 Jul;9(7):991-9
Gating the radical hemoglobin to macrophages: the anti-inflammatory role of CD163, a scavenger receptor.
Schaer DJ, Alayash AI, Buehler PW
Expert Opin Biol Ther 2007 May;7(5):665-75
First-generation blood substitutes: what have we learned? Biochemical and physiological perspectives.
Alayash AI, D'Agnillo F, Buehler PW
J Biol Chem 2007 Feb 16;282(7):4894-907
Structural basis of peroxide mediated changes in human hemoglobin: A novel oxidative pathway.
Jia Y, Buehler PW, Boykins RA, Venable RM, Alayash AI
Biochem J 2006 Nov 1;399(3):513-24
Ascorbate removes key precursors to oxidative damage by cell free hemoglobin in vitro and in vivo.
Dunne J, Caron A, Menu P, Alayash AI, Buehler PW, Wilson MT, Silaghi-Dumitrescu R, Faivre B, Cooper CE
Anal Chem 2006 Jul 1;78(13):4634-4641
Chemical Characterization of Diaspirin Cross-Linked Hemoglobin Polymerized with Poly(ethylene glycol).
Buehler PW, Boykins RA, Norris S, Alayash AI
Blood 2006 Jan 1;107(1):373-80
CD163 is the macrophage scavenger receptor for native and chemically modified hemoglobins in the absence of haptoglobin.
Schaer DJ, Schaer CA, Buehler PW, Boykins RA, Schoedon G, Alayash AI, Schaffner A