scholarly journals Restriction of HIV-1 Infection in Sickle Cell Disease Trait

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 940-940
Author(s):  
Namita Kumari ◽  
Javed Khan ◽  
Tatiana Ammosova ◽  
Asrar Ahmad ◽  
Sharmin Diaz ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Mrna Levels ◽  
Cell Disease ◽  
Intracellular Iron ◽  
Cdk2 Activity ◽  
Hiv 1

Abstract We recently showed that in Sickle Cell Disease (SCD), activation of anti-viral restriction factor SAMHD1 and NF-κB inhibitor, IkBα prevented ex vivo HIV-1 infection. SAMHD1 activation was due to its reduced phosphorylation by CDK2, whose activity was inhibited by reduced intracellular iron levels in SCD peripheral blood mononuclear cells (PBMC). We also found that a hazard ratio associated with HIV infection among 11,412 SCD trait subjects was 1.0% comparing to >2% HIV-1 infection among African-Americans in USA. We compared 9 HbAS HIV-1 infected individuals with 107 HbAA or HbAC HIV-1 infected individuals who were enrolled at Howard University clinic. While hemoglobin levels in these two groups were not significantly different, HIV-1 viral load was significantly lower in HbAS group as well the number of HIV-1 associated complications (Hospitalization) were reduced. In the present study, we analyzed ex vivo HIV-1 infection of SCD trait PBMC and determined the expression of iron and hypoxia-regulated host factors including HO-1, NFκB, IKK, IKBα that are implicated in HIV-1 replication. We also analyzed CDK2 activity, SAMHD1 phosphorylation and RNR2 expression in SCD trait PBMCs. One round HIV-1 infection was significantly reduced in in SCD trait PBMC. Expression of HO-1 and IKBα was upregulated in SCD trait whereas IKK and NF-κB expression was downregulated. While CDK2 activity and SAMHD1 phosphorylation were not changed, RNR2 expression was reduced. Expression levels of HIV-1 env and gag mRNA were significantly lower in HIV-1 infected SCD trait subjects. In the same patients, HO-1 and IKBα mRNA levels were upregulated comparing to HIV-1+ HbAA or HbAC subjects. Our findings suggest that HIV-1 infection might be deregulation in SCD trait and that iron metabolism and hypoxia might play a role in this deregulation. This work was supported by NIH Research Grants 1P50HL118006, 1R01HL125005, and 5G12MD007597. The content is solely the responsibility of the authors and does not necessarily represent the official view of NHLBI, NIMHD or NIH. Disclosures No relevant conflicts of interest to declare.

scholarly journals Interferon Induction By HbS, SERINC5 Upregulation and Reduction of HIV-1 Nef and AP2 Contribute to HIV-1 Restriction in Sickle Cell Disease

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 5-6
Author(s):  
Namita Kumari ◽  
Marina Jerebtsova ◽  
Songping Wang ◽  
Sharmin Diaz ◽  
Sergei Nekhai
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Interferon Response ◽  
Cell Disease ◽  
Restriction Factors ◽  
Peripheral Blood Mononuclear ◽  
Hiv 1

Concerted action of numerous positively acting cellular factors is essential for Human immunodeficiency virus type 1 (HIV-1) replication but in turn is challenged by anti-viral restriction factors. Previously we showed that ex vivo one round HIV-1 replication and replication of fully competent T-tropic HIV-1(IIIB) is significantly reduced in peripheral blood mononuclear cells (PBMCs) obtained from patients with Sickle Cell Disease (SCD). Further, we identified and confirmed CDKN1A (p21) and CH25H as host restriction factors expressed in SCD PBMCs that may contribute to the HIV-1 inhibition, in addition to the previously reported SAMHD1 and IKBα. Since CH25H is an interferon stimulated gene (ISG), we analyzed IRFs and interferon expression in SCD PBMCs. Higher levels of IRF7 and IFNβ mRNA were observed in SCD PBMCs compared to controls. We probed further to ascertain if hemin or sickle Hb was responsible for interferon response. We found upregulation of IFNβ in THP-1 - derived macrophages treated with lysates of HbSS RBCs or purified HbS as compared to untreated or HbA treated controls. HbSS RBCs lysates and purified HbS inhibited HIV-1 gag mRNA expression in monocyte-derived macrophages infected with HIV-1(Ba-L). Recent clinical study showed increased levels of CD4 in HIV-1 infected SCD patients in Africa. Thus we analyzed CD4 levels in HIV-1 IIIB infected SCD PBMCs, and found them to be higher compared to controls. Levels of HIV-1 nef mRNA, that controls CD4 expression was lower in HIV-1 IIIB infected SCD PBMCs. As Nef counteracts SERINC3/5 restriction factor, we analyzed its expression as well as the expression of AP2 clathrin adaptor that is required for Nef mediated internalization of CD4. AP2 expression was lower and SERINC5 expression was higher in SCD PBMCs. CONCLUSIONS: SCD PBMCs could resist HIV-1 infection because of the increased IFNβ production by macrophages exposed to HbSS or sickle cell RBCs. SCD PBMC have increased levels of SERNIC5 and lower levels of HIV-1 Nef and host AP2 expression that, culumlatively, can increased CD4 levels and lead to the overall improved immunological health of SCD patients. ACKNOWLEDGMENTS: This work was supported by NIH Research Grants (1P50HL118006, 1R01HL125005, 1SC1HL150685, 5U54MD007597, 1UM1AI26617 and P30AI087714). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Disclosures No relevant conflicts of interest to declare.

Increased Iron Export By Ferroportin Induces Restriction of HIV-1 Infection in Sickle Cell Disease By SAMHD1

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 201-201
Author(s):  
Namita Kumari ◽  
Tatiana Ammosova ◽  
Sharmeen Diaz ◽  
Xionghao Lin ◽  
Xiaomei Niu ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Reverse Transcription ◽  
Conflicts Of Interest ◽  
Type I ◽  
Cell Disease ◽  
Cell Leukemia Virus Type ◽  
Cdk2 Activity ◽  
Hiv 1 ◽  
Iron Export

Abstract Sickle cell disease (SCD) is a characterized by hemolysis, vaso-occlusion and ischemia. Several previous studies pointed to a possibility that SCD patients might be protected from HIV-1 infection. These studies described low prevalence of anti-HIV-1 antibodies in SCD patients transfused with potentially HIV-1 infected blood;1 higher number of long-term non-progressors among HIV-1 infected SCD patients, 2 and a lower frequency of HIV diagnosis among SCD patients (odds ratio 0.33).3 This study aims to decipher a mechanism of HIV-1 restriction in PBMC from SCD patient infected with HIV-1 ex vivo. HIV-1 replication in SCD PBMC was inhibited at the level of reverse transcription and transcription implicating the involvement of post-entry and transcription restriction factors. SAM domain and HD domain-containing protein 1 (SAMHD1) restricts HIV-1 infection in in myeloid cells. 4,5 by reducing intracellular nucleotide pool and blocking reverse transcription. SAMHD1 phosphorylation on Thr-592 by CDK2 or CDK1 inactivates it and prevents HIV-1 inhibition. We showed that SAMHD1 phosphorylation was reduced in SCD PBMCs and in hemin-treated promonocytic THP-1 cells. Moreover, knock-down of SAMHD1 prevent hemin-mediated inhibition of HIV-1 in THP-1 cells. We also detected a reduction of CDK2 activity in SCD PBMCs and in hemin-treated THP-1 cells which can explain reduced SAMHD1 phosphorylation. Previously, we showed that CDK2 activity is inhibited when intracellular iron levels are depleted by iron chelators. We observed reduced intracellular labile iron levels and increased expression of iron export protein, ferroportin and HIF-1α in SCD PBMCs. Importantly, treatment of SCD PBMCs with hepcidin alleviated HIV-1 inhibition. Unaltered hepcidin levels in plasma of SCD patients suggest that ferroportin expression is sustained in SCD PBMC. Our study points out to ferroportin as upstream regulator of SAMHD1 and links a reduction in iron levels, inhibition of CDK2 activity and a decrease in SAMHD1 phosphorylation to the inhibition of HIV-1 infection in SCD. Acknowledgments. This work was supported by NIH Research Grants 1P50HL118006, 1R01HL125005 and 5G12MD007597. The content is solely the responsibility of the authors and does not necessarily represent the official view of NHLBI, NIMHD or NIH. Literature 1. Castro O, Saxinger C, Barnes S, Alexander S, Flagg R, Frederick W. Prevalence of antibodies to human immunodeficiency virus and to human T cell leukemia virus type I in transfused sickle cell disease patients. J Infect Dis. 1990;162(3):743-745. 2. Bagasra O, Steiner RM, Ballas SK, et al. Viral burden and disease progression in HIV-1-infected patients with sickle cell anemia. Am J Hematol. 1998;59(3):199-207. 3. Nouraie M, Nekhai S, Gordeuk VR. Sickle cell disease is associated with decreased HIV but higher HBV and HCV comorbidities in US hospital discharge records: a cross-sectional study. Sex Transm Infect. 2012. 4. Hrecka K, Hao C, Gierszewska M, et al. Vpx relieves inhibition of HIV-1 infection of macrophages mediated by the SAMHD1 protein. Nature. 2011;474(7353):658-661. 5. Laguette N, Sobhian B, Casartelli N, et al. SAMHD1 is the dendritic- and myeloid-cell-specific HIV-1 restriction factor counteracted by Vpx. Nature. 2011;474(7353):654-657. Disclosures No relevant conflicts of interest to declare.

scholarly journals Restriction of HIV-1 Infection in Sickle Cell Disease and Trait

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2337-2337
Author(s):  
Namita Kumari ◽  
Miguel de Mulder ◽  
Javed Khan ◽  
Asrar Ahmad ◽  
Songping Wang ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Research Funding ◽  
Ex Vivo ◽  
Additional Restriction ◽  
Cell Disease ◽  
Restriction Factors ◽  
Intracellular Iron ◽  
Hiv 1

Abstract BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) replication is controlled by host intrinsic antiviral restriction factors some of which are counteracted by HIV-1 accessory proteins. We recently showed that ex vivo HIV-1 infection is suppressed in PBMCs obtained from Sickle Cell Disease (SCD) patients. The inhibition was mediated in part by SAMHD1 and NF-κB inhibitor, IkBα and triggered by ferroportin, an iron export protein. Ferroportin expression reduced intracellular iron levels and inhibited cellular CDK2 activity leading to reduction of SAMHD1 phosphorylation and increased expression of IkBα. OBJECTIVES: The study was designed to further clarify the mechanism of HIV-1 inhibition in SCD and identify additional HIV-1 restriction factors that may contribute to the restriction mechanism. METHODS: A customized array was utilized to determine the expression of restriction factors in SCD PBMCs. The shRNA-mediated knockdowns of the identified genes were used to further validate the role of these factors in HIV-1 replication in cultured and primary cells. HIV-1(IIIB strain) and VSVG-pseudotyped pNL4-3.Luc.R-E-virus was used to analyze HIV-1 replication. RESULTS: Overexpression of ferroportin in THP-1 cells led to increased expression of HO-1 and p21 and reduced phosphorylation of SAMHD1. Inhibition of HO-1 and p21 by small molecules increased HIV-1 replication in SCD PBMCs suggesting that these factors contributed to the restriction mechanism. Knocking down SAMHD1 in SCD PBMC did not fully restore HIV-1 replication pointing to additional restriction factors. Analysis of HIV-1 restriction factors in SCD PBMCs using customized array showed increased expression of APOBECs, TRIMs, CH25H, CPSF6, CTR9, EIF2ak2, IFI16, MX2, PML and RTF1 mRNAs. We next tested the effect of SCD trait on HIV-1 infection ex vivo and in vivo. PBMCs obtained from SCD trait individuals showed restricted HIV-1 infection with HIV-1(IIIB strain). To further validate these findings, we compared 9 trait (HbAS) HIV-1 infected individuals with 107 non-SCD (HbAA or HbAC) HIV-1 infected individuals from Howard University HIV clinic. HIV-1 viral load and levels of HIV-1 env and gag were significantly lower in HIV-1 infected SCD trait subjects. Expression of HO-1, p21 were increased and RNR2 expression was reduced in SCD trait PBMCs. Small molecule inhibitors of HO-1 and p21 induced HIV-1 replication in SCD trait PBMCs. CONCLUSIONS: Our findings point to HO-1 and p21 as factors that, in addition to SAMHD1 and IKBα, mediate HIV-1 restriction in SCD. In SCD trait, HO-1, p21 and RNR2 play a key role in ex vivo HIV-1 restriction. Thus HIV-1 infection is deregulated not only in SCD patients but also in SCD trait individuals. The HIV-1 restriction is mediated by iron-activated antiviral restriction factors. ACKNOWLEDGMENTS: This work was supported by NIH Research Grants (1P50HL118006, 1R01HL125005, 5G12MD007597, 1UM1AI26617 and P30AI087714). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Disclosures Nekhai: NIMHD, NIH: Research Funding; NHLBI, NIH: Research Funding; NIAID, NIH: Research Funding.

Inhibition of HIV-1 in Sickle Cell Disease Peripheral Blood Mononuclear Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1509-1509
Author(s):  
Tatiana Ammosova ◽  
Sharroya Charles ◽  
Jamie Rotimi ◽  
Altreisha Foster ◽  
Sharmin Diaz ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Cell Disease ◽  
Peripheral Blood Mononuclear ◽  
Regulatory Subunits ◽  
Blood Mononuclear Cells ◽  
Hiv 1

Abstract Abstract 1509 Poster Board I-532 Background The hypoxic response is an important component of the body 's reaction to impaired tissue oxygenation associated with the anemia and vasoocclusive episodes of sickle cell disease (SCD). It has been reported that HIV infection progresses relatively slowly in patients with SCD (Am J Hematol 1998; 59:199-207). We recently showed that HIV-1 transcription and replication is significantly reduced in cells cultured at 3% versus 21% oxygen (J Cell Physiol 2009; in press). Our previous studies indicated that protein phosphatase-1 (PP1) interacts with HIV-1 transcriptional activator, Tat, and thereby participates in the regulation of HIV-1 transcription. Sickle cell patients are in chronically hypoxic state and we hypothesized that HIV-1 replication in their peripheral blood mononuclear cells (PBMCs) would be slower then in controls. Methods We isolated PBMCs from patients with SCD and from normal subjects, activated the cells with phytohemagglutinin and IL-2 for 24 h, and infected with pseudotyped HIV-1 virus expressing Luciferase. The infected cells were cultured at 3% of oxygen for 72 h. Results We show here that PP1 association with cellular regulatory subunits is modified and that PP1 activity is significantly reduced by 20-40% in different cell lines at 3% versus 21% oxygen. One round of replication of pseudotyped HIV-1 Luciferase virus normalized to the number of the cells in culture was significantly reduced in SCD PBMCs comparing to normal controls. Conclusions Our results provide a direct evidence of that HIV-1 replication may be slower in SCD-derived PBMCs. In future, we will analyze PP1 activity and the association of PP1 with regulatory subunits in SCD PBMCs. Understanding of how oxygen status influences HIV-1 replication might open new possibilities for treatment of hidden HIV-1 reservoirs that harbor non-replicating HIV-1 virus. Acknowledgments This work was supported by NHLBI Research Grant 2 R25 HL003679-08 from the National Institutes of Health and The Office of Research on Minority Health. Disclosures No relevant conflicts of interest to declare.

scholarly journals Restriction of HIV-1 Infection in Sickle Cell Trait

2021 ◽  
Author(s):  
Namita Kumari ◽  
Seyed Mehdi Nouraie ◽  
Asrar Ahmad ◽  
Hatajai Lassiter ◽  
Javed I Khan ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Mononuclear Cells ◽  
Sickle Cell Trait ◽  
Ex Vivo ◽  
Heme Oxygenase 1 ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Protein Levels ◽  
Living With Hiv ◽  
Hiv 1

Patients with Sickle cell disease (SCD) have lower risk for HIV-1 infection. We showed restriction of ex vivo HIV-1 infection in SCD peripheral blood mononuclear cells (PBMCs) that was due, in part, to the upregulation of antiviral, inflammatory and hemolytic factors including heme oxygenase-1 (HO-1). Here, we investigated whether individuals with sickle cell trait (SCT), who develop mild hemolysis, also restrict HIV-1 infection. Ex vivo infection of SCT PBMCs demonstrated ~2-fold reduction of HIV-1 replication and lower levels of HIV-1 reverse transcription products, 2-Long Terminal Repeats (LTR) circles, HIV-1 integration and gag RNA expression. SCT PBMCs had higher HO-1 mRNA and protein levels and reduced ribonucleotide reductase 2 (RNR2) protein levels. HO-1 inhibition by tin porphyrin eliminated ex vivo HIV-1 restriction. Among Howard University clinic recruits, higher levels of HO-1 and RNR2 mRNA and lower HIV-1 env mRNA levels were found in SCT individuals living with HIV-1. To determine the population level effect of SCT on HIV-1 prevalence, we assessed SCT trait among women living with HIV (WLH) in the Women Interagency HIV-1 Study (WIHS). Among WIHS African American participants, prevalence of SCT was lower among women with HIV compared with uninfected women (8.7% vs 14.2%; OR 0.57; 95%CI = 0.36-0.92, p=0.020). WIHS WLH with SCT had higher levels of CD4+/CD8+ ratios over 20 years of follow up (p=0.003) than matched WLH without SCT. Together, our findings suggest that HIV-1 restriction factors including HO-1 and RNR2 might restrict HIV-1 infection among individuals with SCT and limit the pathogenicity of HIV.

scholarly journals RN-1, a Potent and Selective LSD1 Inhibitor, Induces High Levels of Fetal Hemoglobin (HbF) in Anemic Baboons (P. anubis)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 336-336 ◽  
Author(s):  
Angela Rivers ◽  
Kestis Vaitkus ◽  
Maria Armila Ruiz ◽  
Vinzon Ibanez ◽  
Tatiana Kouznetsova ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Large Fraction ◽  
Fetal Hemoglobin ◽  
In Vitro Assays ◽  
Mrna Levels ◽  
Cell Disease ◽  
F Cells ◽  
Globin Synthesis

Abstract Increased levels of fetal hemoglobin are associated with decreased symptoms and increased life span in patients with sickle cell disease (SCD). Hydroxyurea, the only drug currently approved for SCD, is not effective in a large fraction of patients and therefore new agents are currently needed. Recent evidence has shown that LSD1, an enzyme that removes monomethyl and dimethyl residues from the lys4 residue of histone H3, is a repressor of γ-globin expression. Tranylcypromine (TCP), an LSD1 inhibitor, was shown to increase γ-globin expression in human βYAC transgenic mice (Shi et al Nat Med 19:291, 2013). Because the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and other simian primates, the use of an simian primate animal model such as the baboon (P.anubis) is the best predictor of the activity of HbF-inducing agents in man. In this investigation we compared the effect of TCP and the more potent and selective LSD1 inhibitor, RN-1, on HbF expression in anemic baboons (P. anubis). In vitro assays have shown that the LSD1 IC50 of RN-1 is at least 1000 fold less than TCP. Animals were phlebotomized for 14d prior to drug treatment to attain an Hct=20 to induce reticulocytosis and establish baseline HbF levels and were maintained at this Hct by periodic phlebotomies during the course of the experiment. In four baboons treated with varying doses of TCP (2-6mg/kg/; 10-20d; sc) low levels of HbF (4.9-7.9% HbF) were induced that were only slightly higher than those observed at the pretreatment baseline (2.2-4.1% HbF). In contrast, treatment with varying doses of RN-1 (2.5-0.125 mg/kg/d; 5-10d) induced high levels of HbF, F reticulocytes, and F cells in 5 of 6 animals (see Table). At high doses of drug the ratio of 5'Iγ/3'Vγ synthesis was >2 demonstrating a near-complete reversion to the pattern of fetal stage expression. Peak levels of F reticulocytes and γ-globin synthesis were observed 8d and HbF and F cells 11d after the first day of drug administration. Increased γ-globin mRNA levels (γ/γ+β) in reticulocytes measured by RT-PCR showed that increased HbF levels were not due to translational effects. Bisulfite sequence analysis showed that levels of DNA methylation of the γ-globin promoter were similar in pre- and post-treatment BM erythroid precursors from two animals. Flow cytometry analysis using anti-α4-integrin and anti-baboon RBC antibodies showed that RN-1 treatment altered terminal BM erythroid differentiation by increasing the proportion of less differentiated precursors, however no changes in MCHC or total hemoglobin synthesis (α/γ+β) were observed. RN-1 treatment was associated with decreased ANC (290-870 X 103/μl nadir) and increased platelets (1092-1445 X 103/μl peak) and monocytes that were likely caused by effects on hematopoietic differentiation. The ANC nadir and peak platelet and monocyte counts were observed between d14-19 and resolved with 2-3 days. Similar changes in ANC and platelets, although not in monocytes, are observed following treatment with decitabine and can be controlled by modification of dose and schedule of administration (Lavelle et al Blood 119:1240, 2012). We conclude that RN-1, a more potent LSD1 inhibitor than TCP, is a powerful HbF-inducing drug with activity similar to decitabine and predict that LSD1 inhibitors may be useful drugs for the treatment of sickle cell disease. Table HbF, F-cells, and F-retics in Baboons Treated with RN-1 Animal RN-1 Dose (mg/kg/d) HbF (%) Globin synthesis (γ/γ+β) F-cells (%) F-retics (%) Pre Post Pre Post Pre Post Pre Post 8548 2.5 (4d) 5.8 27.3 ND 0.78 28.5 59.2 34.6 92.3 8549 0.5 (5d) 2.4 29.5 0.06 0.68 19.1 60.8 33.9 97.5 8000 0.25 (5d) 4.1 20.6 0.15 0.49 20.3 47.0 45.7 80.7 8548 0.20 (5d) 3.7 20.5 0.04 0.52 36.9 54.8 36.9 89.2 8001 0.125 (5d) 1.8 4.8 ND 0.06 13.5 21.8 22.9 31.7 8549 0.125 (10d) 3.6 16 0.04 0.22 17.6 42.7 21.0 70.0 Disclosures No relevant conflicts of interest to declare.

scholarly journals Investigation of Two Combination HbF Induction Regimens, RN-1 and Hydroxyurea Versus RN-1 and Decitabine, in a Humanized Sickle Cell Mouse Model

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3386-3386 ◽  
Author(s):  
Ramasamy Jagadeeswaran ◽  
Yash Agarwal ◽  
Vinzon Ibanez ◽  
Maria Armila Ruiz ◽  
Kestis Vaitkus ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Mouse Model ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
New Combination ◽  
Spleen Weight ◽  
Mrna Levels ◽  
Cell Disease ◽  
Globin Mrna ◽  
Combination Regimens

Abstract Sickle cell disease (SCD) results from the substitution of glutamic acid for valine at the sixth amino acid of β-globin protein, leading to the formation of the abnormal hemoglobin S (HbS). Following deoxygenation in red blood cells (RBCs), HbS forms polymers causing the RBCs to become deformed and adherent leading to vaso-occlusive events resulting in splenic infarction, kidney failure, stroke, painful crises, chronic anemia, inflammation and decreased survival. Hydroxyurea, the only drug currently FDA approved for SCD, is not effective in some patients and, therefore, new combination regimens are needed. RN-1, a new drug targeting the histone demethylase LSD-1, is a more effective inducer of γ-globin expression in sickle cell mice and HbF in baboons (P. anubis). Decitabine(DAC), a DNMT1 inhibitor, is well known to induce high levels of HbF in non-human primates and SCD patients and is currently in clinical trials. We investigated the effect of two combination regimens: RN-1 in combination with hydroxyurea vs. RN-1 in combination with DAC. The knock-in humanized sickle cell mice (B6;129-Hbatm1(HBA)Tow Hbbtm2(HBG1,HBB*)Tow/J) were treated with 1) DMSO (vehicle control), 2) RN-1 (5mg/kg), 3) DAC(0.25mg/kg) and 4) RN-1(5mg/kg) + DAC(0.5mg/kg) for 10 days. Analysis of F-retics and γ-globin mRNA performed on d10 showed F-retics were increased two fold (p=0.01) in mice treated with RN-1(5mg/kg) or DAC(0.25mg/kg) compared to DMSO-treated. γ-globin mRNA levels (γ/γ+β) were increased three fold in RN-1(5mg/kg) or DAC(0.25mg/kg) compared to DMSO. The combination of RN-1(5mg/kg) and DAC(0.25mg/kg) did increase F-retics and mRNA levels compared to mice treated with RN-1 alone(p=0.02). Also, the RN-1 and DAC combination led to neutropenia and thrombocytopenia. We next examined the effect of RN-1(5mg/kg) and HU (100mg/kg) in combination. Knock-in humanized sickle cell mice (B6;129-Hbatm1(HBA)Tow Hbbtm2(HBG1,HBB)Tow/J) were treated with 1) DMSO (vehicle) 2) RN-1(5mg/kg) and 3) RN-1(5mg/kg) + HU (100mg/kg). While RN-1 in combination with HU did not significantly increase F-cells or F-retics, there was a significant decrease in spleen weight [(DMSO: 1.17±0..06g; RN1:0.71± 0.1g; RN1+HU: 0.46±0.05g)(p=0.004:p=0.02)] and percentage of sickle cells in a peripheral blood smear.[(DMSO: 8.4 ±1.3%; RN-1:4.1± 0.2%; RN1+HU: 1.57±0.6%)(p=0.006:p-0.014)]. We conclude that further studies to determine the effect of RN-1 in combination with HU or DAC in the sickle cell mouse model and cultures from sickle cell CD34+ cells are needed to evaluate its potential use in the treatment of sickle cell disease. These results suggest that RN-1 in combination with hydroxyurea may be a useful therapeutic regimen. Disclosures No relevant conflicts of interest to declare.

Placenta growth factor activates monocytes and correlates with sickle cell disease severity

Blood ◽  
2003 ◽  
Vol 102 (4) ◽  
pp. 1506-1514 ◽  
Author(s):  
Natalya Perelman ◽  
Suresh K. Selvaraj ◽  
Sandeep Batra ◽  
Lori R. Luck ◽  
Anat Erdreich-Epstein ◽  
...  
Keyword(s):  
Steady State ◽  
Growth Factor ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Mononuclear Cells ◽  
Mrna Levels ◽  
Healthy Controls ◽  
Erythroid Cells ◽  
Cell Disease ◽  
Placenta Growth Factor

Abstract Sickle cell disease (SCD) results in chronic hypoxia and secondarily increased erythropoietin concentrations. Leukocytosis and activated monocytes are also observed in SCD in absence of infection or vaso-occlusion (steady state), the reasons for which are unknown. We found that erythroid cells produced placenta growth factor (PlGF), an angiogenic growth factor belonging to the vascular endothelial growth factor (VEGF) family, and its expression was induced in bone marrow CD34+ progenitor cells in the presence of erythropoietin. Furthermore, the steady state circulating PlGF levels in subjects with severe SCD (at least 3 vaso-occlusive crises [VOCs] per year) were 18.5 ± 1.2 pg/mL (n = 9) compared with 15.5 ± 1.2 pg/mL (n = 13) in those with mild SCD (fewer than 3 VOCs per year) and 11.3 ± 0.7 pg/mL (n = 9) in healthy controls (P < .05), suggesting a correlation between PlGF levels and SCD severity. In addition, PlGF significantly increased mRNA levels of the proinflammatory cytochemokines interleukin-1β, interleukin-8, monocyte chemoattractant protein-1, and VEGF in peripheral blood mononuclear cells (MNCs) of healthy subjects (n = 4; P < .05). Expression of these same cytochemokines was significantly increased in MNCs from subjects with SCD at steady state (n = 14), compared with healthy controls. Of the leukocyte subfractions, PlGF stimulated monocyte chemotaxis (P < .05, n = 3). Taken together, these data show for the first time that erythroid cells intrinsically release a factor that can directly activate monocytes to increase inflammation. The baseline inflammation seen in SCD has always been attributed to sequelae secondary to the sickling phenomenon. We show that PlGF contributes to the inflammation observed in SCD and increases the incidence of vaso-occlusive events.

scholarly journals Control of HIV-1 Infection By Ferroportin Q248H Mutation

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 953-953
Author(s):  
Namita Kumari ◽  
Seyed Mehdi Nouraie ◽  
Hatajai Lassiter ◽  
Asrar Ahmad ◽  
Kathryn Anastos ◽  
...  
Keyword(s):  
African American ◽  
Viral Load ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Research Funding ◽  
Ex Vivo ◽  
Cell Disease ◽  
Hiv 1 ◽  
Transcription And Replication ◽  
Iron Export

BACKGROUND: We recently showed that patients with Sickle Cell Disease (SCD), a hereditary hemolytic disorder, have low incidence of HIV-1 infection [1] and reduced ex vivo HIV-1 infection [2]. PBMC from SCD patients exhibited increased expression of iron export protein, ferroportin and reduced cellular iron levels leading to CDK2 inhibition, reduced SAMHD1 phosphorylation and increased expression of IkBα. Ferroportin expression is regulated by liver-produced hepcidin that facilitates ferroportin internalization and degradation. Ferroportin Q248H mutation has an allele frequency of 2.2-13.4% in African populations. We previously reported reduced sensitivity of ferroportin Q248H mutant to physiologic hepcidin concentrations in patients with sickle cell disease [3]. OBJECTIVES: To analyze the effect of ferroportin Q248H mutation on HIV-1 infection in vitro and in disease progression among a cohort of HIV-1 infected African-American women. METHODS: HEK293 cells were used to express ferroportin Q248H mutant and test cellular ferritin and intracellular labile iron using calcein-AM. Confocal microscopy was used to visualize ferroportin expression. HIV-1 transcription was measured in 293T cells transfected with HIV-1 LTR-Luciferase vector and Tat expressing vector. Ex vivo infection was analyzed in monocyte-derived macrophages infected with VSVg-pseudotyped HIV-1 virus. Ferroportin Q248H mutation was genotyped using Thermo Fisher probe (C_25753769_10) and genotyping services at University of Utah. RESULTS: We observed reduced intracellular iron in ferroportin Q248H expressing cells compared to WT ferroportin even when the cells were treated with hepcidin. In the absence of hepcidin, both WT ferroportin and Q248H ferroportin efficiently inhibited HIV-1 transcription and replication. Hepcidin induced HIV-1 transcription and replication in the cells with WT ferroportin but not Q248H mutant ferroportin. HIV-1 replication was reduced in primary macrophages obtained from patients with ferroportin Q248H mutation. To test whether expression of ferroportin Q248H offered protection from HIV-1 infection, we analyzed a cohort of HIV-1 infected women (WIHS). We genotyped 970 African-American subjects of whom 628 were HIV-1 infected and 342 were non-infected. The prevalence of Q248H hetero or homozygote mutations was 7.0% in non-infected and 11.8% among HIV-1 infected individuals (Odds Ratio=1.77, p=0.02). Analysis of HIV viral load showed significant lower viral load in the subjects with ferroportin Q248H mutation compared to WT. CONCLUSIONS: Our findings point to the contribution of iron metabolism in HIV-1 restriction and the potential role of the ferroportin Q248H mutation in the regulation of HIV-1 infection in vivo. ACKNOWLEDGMENTS: This work was supported by NIH Research Grants (1P50HL118006, 1R01HL125005, 5G12MD007597 and P30AI087714). We thank Women's Interagency HIV-1 study (WIHS) for sharing DNA samples and providing access to the clinical data. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. REFERENCES: Nouraie M, Nekhai S, Gordeuk VR. Sickle cell disease is associated with decreased HIV but higher HBV and HCV comorbidities in U.S. hospital discharge records: a cross-sectional study. Sex Transm Infect. 2012;88(7):528-533. Kumari N, Ammosova T, Diaz S, et al. Increased iron export by ferroportin induces restriction of HIV-1 infection in sickle cell disease. Blood Adv. 2016;1(3):170-183. Nekhai S, Xu M, Foster A, et al. Reduced sensitivity of the ferroportin Q248H mutant to physiological concentrations of hepcidin. Haematologica. 2013;98(3):455-463. Disclosures Anastos: NINR: Research Funding; NHGRI: Research Funding; NICHD: Research Funding; NIMH: Research Funding; NHLBI: Research Funding; NCI: Research Funding; NIAID: Research Funding; NINDS: Research Funding; NIDCR: Research Funding; NIMHD: Research Funding; NLM: Research Funding; Fogarty: Research Funding; NIDDK: Research Funding; NIA: Research Funding; NIAAA: Research Funding; NIDA: Research Funding.

scholarly journals Increased iron export by ferroportin induces restriction of HIV-1 infection in sickle cell disease

2016 ◽  
Vol 1 (3) ◽  
pp. 170-183 ◽  
Author(s):  
Namita Kumari ◽  
Tatiana Ammosova ◽  
Sharmin Diaz ◽  
Xionghao Lin ◽  
Xiaomei Niu ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Cell Disease ◽  
Intracellular Iron ◽  
Key Points ◽  
Hiv 1 ◽  
Iron Export

Key PointsFerroportin reduces intracellular iron, inhibits CDK2 and suppresses SAMHD1 phosphorylation thus inhibiting HIV-1 RT. Ferroportin expression leads to overexpression of IKBα and inhibition of HIV-1 transcription.

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