Our goal is to design and establish novel therapeutic agents for sickle cell disease (SCD), namely drugs that inhibit the initial sickle hemoglobin (HbS) polymerization and the subsequent pathophysiology. When deoxygenated, HbS polymerizes into long, rigid, and insoluble fibers causing red blood cells (RBCs) to sickle, a process worsened by the unusual low affinity of HbS for oxygen, resulting in premature release of oxygen. Based on several evidence--our preliminary data, studies by others, and the results of a recently completed phase I/II clinical testing of our lead compound, 5-HMF (an allosteric effector of Hb, AEH)-we hypothesize that AEHs, not only prevent HbS polymerization, but also mitigates several secondary sickling related pathological events that include inflammation, oxidative stress/damage, RBC hemolysis, and pain. We also have preliminary evidence that our next generation AEHs (INN- and TD-series) exhibit enhanced potency and improved in-vitro duration of action. These AEHs act via a novel mechanism of action, i.e., destabilize HbS polymer contacts, in addition to increasing Hb affinity for oxygen; providing positive synergistic effects. We propose to test our hypothesis by further investigating candidate drugs from the INN- and TD-series, as well as derivatives of 5-HMF and INN-312 for their pharmacologic properties, focusing on the secondary SCD pathways, as well as the underlying HbS polymerization problem using our model systems.
The specific aims are: 1. Design and synthesis of novel allosteric effectors of hemoglobin (AEHs). We will modify our parent compounds and synthesize derivatives with enhanced efficacy and prolonged half-lives. We will also synthesize prod rugs to protect the active aldehyde functional moiety from aldehyde dehydrogenase (ALDH)- mediated metabolism as necessary. 2. Investigate in-vitro functional, ant sickling, and cytotoxicity activities of novel AEHs. We will investigate the AEHs for their in-vitro ant sickling/functional activities (RBC sickling tests, P50 analyses, HbS solubility, and Hb adduct formation), and carefully monitor for adverse effects. 3. Determine in-vivo/in-vitro PK/PD properties, binding and metabolism and evaluate preclinical efficacy of AEHs in SCD Berkeley mice. We will show that serum albumin binding and/or metabolism by ALDH in RBC or hepatic cytosol are not likely to adversely affect in-vivo pharmacologic activity. We will demonstrate using a Berkeley mouse model of SCD transgenic mice that AEHs show potent pharmacologic effects, increase short- and long-term survival rates of mice. We will also study their potential beneficial effects, e.g. amelioration of hemolysis, inflammation, endothelial damage, and overall reversal of the SCD pathophysiology observed in this model. 4. Determine the atomic interactions between AEHs and Hb. X-ray crystallography will be used to validate our hypothesis that AEH potency is directly dependent upon their abilities to bind Hb with their pyridyl substituents toward the surface of the Hb molecule. The structures would provide valuable insight to help guide rational modifications for better pharmacologic properties.

Public Health Relevance

Sickle cell disease (SCD) is the most common inherited hematologic disorder, affecting over 80,000 people, primarily African-American in the US, exacerbating the disproportionate health disparity among this minority population. Most common therapeutic intervention includes blood transfusions and hydroxyurea therapies, however, these therapies are associated with some undesirable side effects and not all patients benefit from the treatment. Thus, there is still a need to develop new, more effective and non-toxic therapeutic agents against this debilitating disease.

Agency
National Institute of Health (NIH)
Institute
National Institute on Minority Health and Health Disparities (NIMHD)
Type
Research Project (R01)
Project #
5R01MD009124-05
Application #
9465242
Study Section
Special Emphasis Panel (ZMD1)
Program Officer
Rajapakse, Nishadi
Project Start
2014-07-11
Project End
2019-04-30
Budget Start
2018-05-01
Budget End
2019-04-30
Support Year
5
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Virginia Commonwealth University
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
105300446
City
Richmond
State
VA
Country
United States
Zip Code
23298
Rodríguez-Soto, Ana E; Langham, Michael C; Abdulmalik, Osheiza et al. (2018) MRI quantification of human fetal O2 delivery rate in the second and third trimesters of pregnancy. Magn Reson Med 80:1148-1157
Grevet, Jeremy D; Lan, Xianjiang; Hamagami, Nicole et al. (2018) Domain-focused CRISPR screen identifies HRI as a fetal hemoglobin regulator in human erythroid cells. Science 361:285-290
Pagare, Piyusha P; Ghatge, Mohini S; Musayev, Faik N et al. (2018) Rational design of pyridyl derivatives of vanillin for the treatment of sickle cell disease. Bioorg Med Chem 26:2530-2538
Xu, Guoyan G; Pagare, Piyusha P; Ghatge, Mohini S et al. (2017) Design, Synthesis, and Biological Evaluation of Ester and Ether Derivatives of Antisickling Agent 5-HMF for the Treatment of Sickle Cell Disease. Mol Pharm 14:3499-3511
Sun, Kaiqi; D'Alessandro, Angelo; Ahmed, Mostafa H et al. (2017) Structural and Functional Insight of Sphingosine 1-Phosphate-Mediated Pathogenic Metabolic Reprogramming in Sickle Cell Disease. Sci Rep 7:15281
Omar, Abdelsattar M; Mahran, Mona A; Ghatge, Mohini S et al. (2016) Aryloxyalkanoic Acids as Non-Covalent Modifiers of the Allosteric Properties of Hemoglobin. Molecules 21:
Ghatge, Mohini S; Ahmed, Mostafa H; Omar, Abdel Sattar M et al. (2016) Crystal structure of carbonmonoxy sickle hemoglobin in R-state conformation. J Struct Biol 194:446-50
Zimmerman, Devon; Dienes, Jack; Abdulmalik, Osheiza et al. (2016) Purification of diverse hemoglobins by metal salt precipitation. Protein Expr Purif 125:74-82
Oder, Esther; Safo, Martin K; Abdulmalik, Osheiza et al. (2016) New developments in anti-sickling agents: can drugs directly prevent the polymerization of sickle haemoglobin in vivo? Br J Haematol 175:24-30
Sun, Kaiqi; Zhang, Yujin; D'Alessandro, Angelo et al. (2016) Sphingosine-1-phosphate promotes erythrocyte glycolysis and oxygen release for adaptation to high-altitude hypoxia. Nat Commun 7:12086

Showing the most recent 10 out of 14 publications