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Wang M, Xu XR, Bai QX, Wu LH, Yang XP, Yang DQ, Kuang HX. Dichroa febrifuga Lour.: A review of its botany, traditional use, phytochemistry, pharmacological activities, toxicology, and progress in reducing toxicity. JOURNAL OF ETHNOPHARMACOLOGY 2024; 328:118093. [PMID: 38537842 DOI: 10.1016/j.jep.2024.118093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/06/2024] [Accepted: 03/21/2024] [Indexed: 04/05/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Dichroa febrifuga Lour., a toxic but extensively used traditional Chinese medicine with a remarkable effect, is commonly called "Changshan" in China. It has been used to treat malaria and many other parasitic diseases. AIM OF THE REVIEW The study aims to provide a current overview of the progress in the research on traditional use, phytochemistry, pharmacological activities, toxicology, and methods of toxicity reduction of D. febrifuga. Additionally, further research directions and development prospects for the plant were put forward. MATERIALS AND METHODS The article uses "Dichroa febrifuga Lour." "D. febrifuga" as the keyword and all relevant information on D. febrifuga was collected from electronic searches (Elsevier, PubMed, ACS, CNKI, Google Scholar, and Baidu Scholar), doctoral and master's dissertations and classic books about Chinese herbs. RESULTS 30 chemical compounds, including alkaloids, terpenoids, flavonoids and other kinds, were isolated and identified from D. febrifuga. Modern pharmacological studies have shown that these components have a variety of pharmacological activities, including anti-malarial activities, anti-inflammatory activities, anti-tumor activities, anti-parasitic activities and anti-oomycete activities. Meanwhile, alkaloids, as the material basis of its efficacy, are also the source of its toxicity. It can cause multiple organ damage, including liver, kidney and heart, and cause adverse reactions such as nausea and vomiting, abdominal pain and diarrhea. In the current study, the toxicity can be reduced by modifying the structure of the compound, processing and changing the dosage forms. CONCLUSIONS There are few studies on the chemical constituents of D. febrifuga, so the components and their structure characterization contained in it can become the focus of future research. In view of the toxicity of D. febrifuga, there are many methods to reduce it, but the safety and rationality of these methods need further study.
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Affiliation(s)
- Meng Wang
- Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin, 150000, China.
| | - Xin-Rui Xu
- Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin, 150000, China.
| | - Qian-Xiang Bai
- Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin, 150000, China.
| | - Li-Hong Wu
- Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin, 150000, China.
| | - Xin-Peng Yang
- Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin, 150000, China.
| | - De-Qiang Yang
- Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin, 150000, China.
| | - Hai-Xue Kuang
- Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, Heilongjiang University of Chinese Medicine, Harbin, 150000, China.
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Wang Z, Jin A, Yang Z, Huang W. Advanced Nitric Oxide Generating Nanomedicine for Therapeutic Applications. ACS NANO 2023; 17:8935-8965. [PMID: 37126728 PMCID: PMC10395262 DOI: 10.1021/acsnano.3c02303] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Nitric oxide (NO), a gaseous transmitter extensively present in the human body, regulates vascular relaxation, immune response, inflammation, neurotransmission, and other crucial functions. Nitrite donors have been used clinically to treat angina, heart failure, pulmonary hypertension, and erectile dysfunction. Based on NO's vast biological functions, it further can treat tumors, bacteria/biofilms and other infections, wound healing, eye diseases, and osteoporosis. However, delivering NO is challenging due to uncontrolled blood circulation release and a half-life of under five seconds. With advanced biotechnology and the development of nanomedicine, NO donors packaged with multifunctional nanocarriers by physically embedding or chemically conjugating have been reported to show improved therapeutic efficacy and reduced side effects. Herein, we review and discuss recent applications of NO nanomedicines, their therapeutic mechanisms, and the challenges of NO nanomedicines for future scientific studies and clinical applications. As NO enables the inhibition of the replication of DNA and RNA in infectious microbes, including COVID-19 coronaviruses and malaria parasites, we highlight the potential of NO nanomedicines for antipandemic efforts. This review aims to provide deep insights and practical hints into design strategies and applications of NO nanomedicines.
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Affiliation(s)
- Zhixiong Wang
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Albert Jin
- Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Zhen Yang
- Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Normal University, Fuzhou, Fujian 350117, China
- Strait Laboratory of Flexible Electronics (SLoFE), Fuzhou, Fujian 350117, China
| | - Wei Huang
- Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Normal University, Fuzhou, Fujian 350117, China
- Strait Laboratory of Flexible Electronics (SLoFE), Fuzhou, Fujian 350117, China
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Aksić J, Genčić M, Stojanović N, Radulović N, Zlatković D, Dimitrijević M, Stojanović-Radić Z, Srbljanović J, Štajner T, Jovanović L. New Iron Twist to Chloroquine─Upgrading Antimalarials with Immunomodulatory and Antimicrobial Features. J Med Chem 2023; 66:2084-2101. [PMID: 36661364 DOI: 10.1021/acs.jmedchem.2c01851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Herein, upgraded chloroquine (CQ) derivatives capable of overcoming Plasmodium resistance and, at the same time, suppressing excessive immune response and risk of concurrent bacteremia were developed. Twelve new ferrocene-CQ hybrids tethered with a small azathia heterocycle (1,3-thiazolidin-4-one, 1,3-thiazinan-4-one, or 5-methyl-1,3-thiazolidin-4-one) were synthesized and fully characterized. All hybrids were evaluated for their in vitro antiplasmodial, antimicrobial, and immunomodulatory activities. Additional assays were performed on selected hybrids to gain insights into their mode of action. Although only hybrid 4a was more potent than the parent drug toward CQ-resistant Dd2 Plasmodium falciparum strain, several other hybrids (such as 6b, 6c, and 6d) manifested substantially improved antimicrobial and immunomodulatory properties. Interesting structure-activity relationship data were obtained, hinting at future research for the development of new multitarget chemotherapies for malaria and other infectious diseases complicated by drug resistance, bacterial co-infection, and immune-driven pathology issues.
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Affiliation(s)
- Jelena Aksić
- Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18000Niš, Serbia
| | - Marija Genčić
- Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18000Niš, Serbia
| | - Nikola Stojanović
- Department of Physiology, Faculty of Medicine, University of Niš, Bulevar Zorana D̵ind̵ića 81, 18000Niš, Serbia
| | - Niko Radulović
- Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18000Niš, Serbia
| | - Dragan Zlatković
- Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18000Niš, Serbia
| | - Marina Dimitrijević
- Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18000Niš, Serbia
| | - Zorica Stojanović-Radić
- Department of Biology and Ecology, Faculty of Sciences and Mathematics, University of Niš, Višegradska 33, 18000Niš, Serbia
| | - Jelena Srbljanović
- National Reference Laboratory for Toxoplasmosis, Centre for Parasitic Zoonoses, Institute for Medical Research, University of Belgrade, Dr. Subotića 4, 11129Belgrade, Serbia
| | - Tijana Štajner
- National Reference Laboratory for Toxoplasmosis, Centre for Parasitic Zoonoses, Institute for Medical Research, University of Belgrade, Dr. Subotića 4, 11129Belgrade, Serbia
| | - Ljiljana Jovanović
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, 21000Novi Sad, Serbia
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Scovino AM, Totino PRR, Morrot A. Eryptosis as a New Insight in Malaria Pathogenesis. Front Immunol 2022; 13:855795. [PMID: 35634341 PMCID: PMC9136947 DOI: 10.3389/fimmu.2022.855795] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 04/04/2022] [Indexed: 11/25/2022] Open
Abstract
Eryptosis is a programmed cell death-like process that occurs in red blood cells. Although the red blood cells are anucleated, there are similarities between eryptosis and apoptosis, such as increased calcium efflux, calpain activation, phosphatidylserine exposure, cell blebbing and cell shrinkage. Eryptosis occurs physiologically in red blood cells, as a consequence of the natural senescence process of these cells, but it can also be stimulated in pathological situations such as metabolic syndromes, uremic syndromes, polycythemia vera, anemias such as sickle cell anemia and thalassemia, and infectious processes including Plasmodium infection. Infection-induced eryptosis is believed to contribute to damage caused by Plasmodium, but it’s still a topic of debate in the literature. In this review, we provided an overview of eryptosis mechanisms and its possible pathogenic role in malaria.
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Affiliation(s)
- Aline Miranda Scovino
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Alexandre Morrot
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
- Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- *Correspondence: Alexandre Morrot,
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Wilairatana P, Mahannop P, Tussato T, Hayeedoloh IM, Boonhok R, Klangbud WK, Mala W, Kotepui KU, Kotepui M. C-reactive protein as an early biomarker for malaria infection and monitoring of malaria severity: a meta-analysis. Sci Rep 2021; 11:22033. [PMID: 34764364 PMCID: PMC8585865 DOI: 10.1038/s41598-021-01556-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/01/2021] [Indexed: 02/07/2023] Open
Abstract
This study investigated whether C-reactive protein (CRP) can be used as a marker for the early detection and monitoring of malaria severity. Potentially relevant studies were searched in Medline (PubMed), Scopus, and Web of Science. Differences in CRP between (1) severe malaria and uncomplicated malaria, (2) uncomplicated malaria and asymptomatic malaria, (3) uncomplicated malaria and febrile/healthy controls, and (4) asymptomatic malaria and febrile/healthy controls were estimated using random-effects models. Twenty-nine studies were included for meta-analysis. The results of meta-analysis demonstrated higher mean CRP levels in (1) patients with severe malaria compared with uncomplicated malaria (p < 0.001, standard mean difference [SMD]: 1.52, 95% confidence interval [CI]: 0.91-2.12, I2: 95.1%), (2) patients with uncomplicated malaria than in those with asymptomatic malaria (p: 0.001, SMD: 1.65, 95% CI: 0.67-2.62, I2: 96.7%), (3) patients with uncomplicated malaria compared with febrile/healthy controls (p < 0.001, SMD: 2.38, 95% CI: 1.37-3.40, I2: 98.5%), and (4) patients with asymptomatic malaria compared with febrile/healthy controls (p < 0.001, SMD: 2.55, 95% CI: 1.60-3.50, I2: 99.2%). This study demonstrated CRP levels are a biomarker for the early detection and monitoring of malaria severity.
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Affiliation(s)
- Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Praphassorn Mahannop
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Thanita Tussato
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - I-Mee Hayeedoloh
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Rachasak Boonhok
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Wiyada Kwanhian Klangbud
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Wanida Mala
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Kwuntida Uthaisar Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Manas Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand.
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Tetteh M, Addai-Mensah O, Siedu Z, Kyei-Baafour E, Lamptey H, Williams J, Kupeh E, Egbi G, Kwayie AB, Abbam G, Afrifah DA, Debrah AY, Ofori MF. Acute Phase Responses Vary Between Children of HbAS and HbAA Genotypes During Plasmodium falciparum Infection. J Inflamm Res 2021; 14:1415-1426. [PMID: 33889007 PMCID: PMC8055362 DOI: 10.2147/jir.s301465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/26/2021] [Indexed: 11/25/2022] Open
Abstract
Purpose Haemoglobin genotype S is known to offer protection against Plasmodium falciparum infections but the mechanism underlying this protection is not completely understood. Associated changes in acute phase proteins (APPs) during Plasmodium falciparum infections between Haemoglobin AA (HbAA) and Haemoglobin AS (HbAS) individuals also remain unclear. This study aimed to evaluate changes in three APPs and full blood count (FBC) indices of HbAA and HbAS children during Plasmodium falciparum infection. Methods Venous blood was collected from three hundred and twenty children (6 months to 15 years) in Begoro in Fanteakwa District of Ghana during a cross-sectional study. Full blood count (FBC) indices were measured and levels of previously investigated APPs in malaria patients; C-reactive protein (CRP), ferritin and transferrin measured using Enzyme-Linked Immunosorbent Assays. Results Among the HbAA and HbAS children, levels of CRP and ferritin were higher in malaria positive children as compared to those who did not have malaria. The mean CRP levels were significantly higher among HbAA children (p=0.2e-08) as compared to the HbAS children (p=0.43). Levels of transferrin reduced in both HbAA and HbAS children with malaria, but the difference was only significant among HbAA children (p=0.0038), as compared to the HbAS children. No significant differences were observed in ferritin levels between HbAA and HbAS children in both malaria negative (p=0.76) and positive (p=0.26) children. Of the full blood count indices measured, red blood cell count (p=0.044) and haemoglobin (Hb) levels (p=0.017) differed between HbAA and HbAS in those without malaria, with higher RBC counts and lower Hb levels found in HbAS children. In contrast, during malaria, lymphocyte and platelet counts were elevated, whilst granulocytes and Mean Cell Haematocrit counts were reduced among children of the HbAS genotypes. Conclusion Significant changes in APPs were found in HbAA children during malaria as compared to HbAS children, possibly due to differences in malaria-induced inflammation levels. This suggests that the HbAS genotype is associated with better control of P. falciparum infection-induced inflammatory response than HbAA genotype.
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Affiliation(s)
- Mary Tetteh
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,Laboratory Department, District Hospital, Begoro, Ghana
| | - Otchere Addai-Mensah
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Zakaria Siedu
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.,West Africa Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
| | - Eric Kyei-Baafour
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Helena Lamptey
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Jovis Williams
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Edward Kupeh
- Laboratory Department, Tema Polyclinic, Tema, Ghana
| | - Godfred Egbi
- Nutrition Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | | | - Gabriel Abbam
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.,University Clinic Laboratory, University of Education, Winneba, Ghana
| | - David Amoah Afrifah
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Alexander Yaw Debrah
- Department of Medical Diagnostics, Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Michael Fokuo Ofori
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.,West Africa Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
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Penha-Gonçalves C. Genetics of Malaria Inflammatory Responses: A Pathogenesis Perspective. Front Immunol 2019; 10:1771. [PMID: 31417551 PMCID: PMC6682681 DOI: 10.3389/fimmu.2019.01771] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 07/15/2019] [Indexed: 12/27/2022] Open
Abstract
Despite significant progress in combating malaria in recent years the burden of severe disease and death due to Plasmodium infections remains a global public health concern. Only a fraction of infected people develops severe clinical syndromes motivating a longstanding search for genetic determinants of malaria severity. Strong genetic effects have been repeatedly ascribed to mutations and allelic variants of proteins expressed in red blood cells but the role of inflammatory response genes in disease pathogenesis has been difficult to discern. We revisited genetic evidence provided by inflammatory response genes that have been repeatedly associated to malaria, namely TNF, NOS2, IFNAR1, HMOX1, TLRs, CD36, and CD40LG. This highlighted specific genetic variants having opposing roles in the development of distinct malaria clinical outcomes and unveiled diverse levels of genetic heterogeneity that shaped the complex association landscape of inflammatory response genes with malaria. However, scrutinizing genetic effects of individual variants corroborates a pathogenesis model where pro-inflammatory genetic variants acting in early infection stages contribute to resolve infection but at later stages confer increased vulnerability to severe organ dysfunction driven by tissue inflammation. Human genetics studies are an invaluable tool to find genes and molecular pathways involved in the inflammatory response to malaria but their precise roles in disease pathogenesis are still unexploited. Genome editing in malaria experimental models and novel genotyping-by-sequencing techniques are promising approaches to delineate the relevance of inflammatory response gene variants in the natural history of infection thereby will offer new rational angles on adjuvant therapeutics for prevention and clinical management of severe malaria.
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Gramaglia I, Velez J, Chang YS, Caparros-Wanderley W, Combes V, Grau G, Stins MF, van der Heyde HC. Citrulline protects mice from experimental cerebral malaria by ameliorating hypoargininemia, urea cycle changes and vascular leak. PLoS One 2019; 14:e0213428. [PMID: 30849122 PMCID: PMC6407779 DOI: 10.1371/journal.pone.0213428] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 02/21/2019] [Indexed: 12/18/2022] Open
Abstract
Clinical and model studies indicate that low nitric oxide (NO) bioavailability due in part to profound hypoargininemia contributes to cerebral malaria (CM) pathogenesis. Protection against CM pathogenesis may be achieved by altering the diet before infection with Plasmodium falciparum infection (nutraceutical) or by administering adjunctive therapy that decreases CM mortality (adjunctive therapy). This hypothesis was tested by administering citrulline or arginine in experimental CM (eCM). We report that citrulline injected as prophylaxis immediately post infection (PI) protected virtually all mice by ameliorating (i) hypoargininemia, (ii) urea cycle impairment, and (iii) disruption of blood brain barrier. Citrulline prophylaxis inhibited plasma arginase activity. Parasitemia was similar in citrulline- and vehicle control-groups, indicating that protection from pathogenesis was not due to decreased parasitemia. Both citrulline and arginine administered from day 1 PI in the drinking water significantly protected mice from eCM. These observations collectively indicate that increasing dietary citrulline or arginine decreases eCM mortality. Citrulline injected ip on day 4 PI with quinine-injected ip on day 6 PI partially protected mice from eCM; citrulline plus scavenging of superoxide with pegylated superoxide dismutase and pegylated catalase protected all recipients from eCM. These findings indicate that ameliorating hypoargininemia with citrulline plus superoxide scavenging decreases eCM mortality.
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Affiliation(s)
- Irene Gramaglia
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
- * E-mail:
| | - Joyce Velez
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
| | | | | | - Valery Combes
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
- School of Life Sciences, University of Technology Sydney, Sydney, Australia
| | - Georges Grau
- La Jolla Infectious Disease Institute, San Diego, CA, United States of America
- Vascular Immunology Unit, University of Sydney, Sydney, Australia
| | - Monique F. Stins
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
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Najjar N, McColl ER, Weckman A, Kain KC, Piquette-Miller M. Dysregulation of solute carrier transporters in malaria-infected pregnant mice. Parasite Immunol 2019; 41:e12614. [PMID: 30703256 DOI: 10.1111/pim.12614] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 12/18/2022]
Abstract
AIMS Malaria in pregnancy (MiP) alters the expression of ATP-binding cassette efflux transporters in maternal and foetal tissues, as well as the placenta. Malaria induces oxidative stress, and pregnancy is associated with arginine deficiency. We hypothesized that reducing oxidative stress during MiP by supplementation with L-arginine, a NO precursor, would attenuate transcriptional changes in a second superfamily of transporters, solute carrier (SLC) transporters, and improve pregnancy outcomes. METHODS AND RESULTS Pregnant BALB/c mice receiving L-arginine (1.2%) in water, or water alone, were infected with Plasmodium berghei ANKA on gestational day 13 and sacrificed on gestational day 19. Compared to controls, the mRNA of numerous SLC transporters was downregulated in maternal and foetal tissues, as well as in the placentas of infected mice. While supplementation with L-arginine did improve foetal viability, it did not improve the mRNA expression of oxidative stress markers, transporters nor other indices of foetal and maternal health. Moreover, amino acid uptake transporters were downregulated upon infection, which could potentially contribute to decreased foetal birthweight. CONCLUSIONS Malaria in pregnancy significantly alters the expression of SLC transporters in maternal and foetal tissues as well as the placenta, regardless of L-arginine supplementation. Further studies to investigate methods of reducing oxidative stress in MiP are warranted.
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Affiliation(s)
- Najwa Najjar
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Eliza R McColl
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Andrea Weckman
- Sandra Rotman Centre for Global Health, University Health Network: Toronto General Hospital, Toronto, Ontario, Canada
| | - Kevin C Kain
- Sandra Rotman Centre for Global Health, University Health Network: Toronto General Hospital, Toronto, Ontario, Canada
| | - Micheline Piquette-Miller
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
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Corbett Y, D'Alessandro S, Parapini S, Scaccabarozzi D, Kalantari P, Zava S, Giavarini F, Caruso D, Colombo I, Egan TJ, Basilico N. Interplay between Plasmodium falciparum haemozoin and L-arginine: implication for nitric oxide production. Malar J 2018; 17:456. [PMID: 30522493 PMCID: PMC6282336 DOI: 10.1186/s12936-018-2602-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 11/29/2018] [Indexed: 01/07/2023] Open
Abstract
Background Plasmodium falciparum haemozoin, a detoxification product of digested haemoglobin from infected erythrocytes, is released into the bloodstream upon schizont rupture and accumulates in leukocytes. High levels of haemozoin correlate with disease severity. Some studies have shown that concentrations of the substrate of inducible nitric oxide synthase (iNOS), l-arginine, as well as nitric oxide are low in patients infected with P. falciparum malaria. The present study investigates, in vitro, the role of P. falciparum haemozoin on nitric oxide production, iNOS expression in macrophages, and the possible interaction between l-arginine and haemozoin. Methods Plasmodium falciparum haemozoin was obtained from in vitro cultures through magnetic isolation. Phagocytosis of haemozoin by immortalized bone marrow derived macrophages was detected by confocal reflection combined with fluorescence microscopy. Nitrite concentrations in the supernatants was evaluated by Griess assay as a standard indication of nitric oxide production, while iNOS expression was detected on cell extracts by western blotting. Detection of l-arginine in haemozoin-treated or untreated media was achieved by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Results Haemozoin synergizes in vitro with interferon-gamma to produce nitric oxide. However, when mouse macrophages were stimulated with haemozoin, a proportional increase of nitric oxide was observed up to 25 μM of haemozoin, followed by a decrease with doses up to 100 μM, when nitric oxide release was completely abrogated. This was not due to reactive oxygen species production, nor to an effect on iNOS activity. Interestingly, when at 24 h, haemozoin-treated macrophages were washed and incubated in fresh medium for further 24 h, the nitric oxide production was restored in a dose–response manner. Similar results were seen when l-arginine-enriched media was used in the stimulation. Moreover, muramyldipeptide, a strong nitric oxide inducer, was unable to activate macrophages to release nitric oxide in the presence of haemozoin-treated medium. By LC–MS/MS a complete depletion of l-arginine was observed in this haemozoin-treated, conditioned medium. Conclusions It is proposed that haemozoin interacts with l-arginine reducing its availability for iNOS, and thus decreasing nitric oxide production. The clinical (or pathological) implications of these results are discussed. Electronic supplementary material The online version of this article (10.1186/s12936-018-2602-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yolanda Corbett
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy. .,Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, MI, Italy.
| | - Sarah D'Alessandro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy.,Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Silvia Parapini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy.,Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Diletta Scaccabarozzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Parisa Kalantari
- Department of Immunology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Stefania Zava
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Flavio Giavarini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Donatella Caruso
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Irma Colombo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
| | - Nicoletta Basilico
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133, Milan, MI, Italy
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11
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Abstract
Erythrocytes regulate vascular function through the modulation of oxygen delivery and the scavenging and generation of nitric oxide (NO). First, hemoglobin inside the red blood cell binds oxygen in the lungs and delivers it to tissues throughout the body in an allosterically regulated process, modulated by oxygen, carbon dioxide and proton concentrations. The vasculature responds to low oxygen tensions through vasodilation, further recruiting blood flow and oxygen carrying erythrocytes. Research has shown multiple mechanisms are at play in this classical hypoxic vasodilatory response, with a potential role of red cell derived vasodilatory molecules, such as nitrite derived nitric oxide and red blood cell ATP, considered in the last 20 years. According to these hypotheses, red blood cells release vasodilatory molecules under low oxygen pressures. Candidate molecules released by erythrocytes and responsible for hypoxic vasodilation are nitric oxide, adenosine triphosphate and S-nitrosothiols. Our research group has characterized the biochemistry and physiological effects of the electron and proton transfer reactions from hemoglobin and other ferrous heme globins with nitrite to form NO. In addition to NO generation from nitrite during deoxygenation, hemoglobin has a high affinity for NO. Scavenging of NO by hemoglobin can cause vasoconstriction, which is greatly enhanced by cell free hemoglobin outside of the red cell. Therefore, compartmentalization of hemoglobin inside red blood cells and localization of red blood cells in the blood stream are important for healthy vascular function. Conditions where erythrocyte lysis leads to cell free hemoglobin or where erythrocytes adhere to the endothelium can result in hypertension and vaso constriction. These studies support a model where hemoglobin serves as an oxido-reductase, inhibiting NO and promoting higher vessel tone when oxygenated and reducing nitrite to form NO and vasodilate when deoxygenated.
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Affiliation(s)
- Christine C Helms
- Physics Department, University of Richmond, Richmond, VA, United States
| | - Mark T Gladwin
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, United States.,Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Daniel B Kim-Shapiro
- Physics Department, Wake Forest University, Winston-Salem, NC, United States.,Translational Science Center, Wake Forest University, Winston-Salem, NC, United States
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12
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Oliveira KRHM, Kauffmann N, Leão LKR, Passos ACF, Rocha FAF, Herculano AM, do Nascimento JLM. Cerebral malaria induces electrophysiological and neurochemical impairment in mice retinal tissue: possible effect on glutathione and glutamatergic system. Malar J 2017; 16:440. [PMID: 29096633 PMCID: PMC5668953 DOI: 10.1186/s12936-017-2083-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 10/23/2017] [Indexed: 01/28/2023] Open
Abstract
Background Cerebral malaria (CM) is a severe complication resulting from Plasmodium falciparum infection. This condition has usually been associated with cognitive, behavioural and motor dysfunctions, being the retinopathy the most serious consequence resulting from the disease. The pathophysiological mechanisms underlying this complication remain incompletely understood. Several experimental models of CM have already been developed in order to clarify those mechanisms related to this syndrome. In this context, the present work has been performed to investigate which possible electrophysiological and neurochemistry alterations could be involved in the CM pathology. Methods Experimental CM was induced in Plasmodium berghei-infected male and female C57Bl/6 mice. The survival and neurological symptoms of CM were registered. Brains and retina were assayed for TNF levels and NOS2 expression. Electroretinography measurements were recorded to assessed a- and b-wave amplitudes and neurochemicals changes were evaluated by determination of glutamate and glutathione levels by HPLC. Results Susceptible C57Bl/6 mice infected with ≈ 106 parasitized red blood cells (P. berghei ANKA strain), showed a low parasitaemia, with evident clinical signs as: respiratory failure, ataxia, hemiplegia, and coma followed by animal death. In parallel to the clinical characterization of CM, the retinal electrophysiological analysis showed an intense decrease of a- and-b-wave amplitude associated to cone photoreceptor response only at the 7 days post-infection. Neurochemical results demonstrated that the disease led to a decrease in the glutathione levels with 2 days post inoculation. It was also demonstrated that the increase in the glutathione levels during the infection was followed by the increase in the 3H-glutamate uptake rate (4 and 7 days post-infection), suggesting that CM condition causes an up-regulation of the transporters systems. Furthermore, these findings also highlighted that the electrophysiological and neurochemical alterations occurs in a manner independent on the establishment of an inflammatory response, once tumour necrosis factor levels and inducible nitric oxide synthase expression were altered only in the cerebral tissue but not in the retina. Conclusions In summary, these findings indicate for the first time that CM induces neurochemical and electrophysiological impairment in the mice retinal tissue, in a TNF-independent manner.
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Affiliation(s)
- Karen R H M Oliveira
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil.
| | - Nayara Kauffmann
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - Luana K R Leão
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - Adelaide C F Passos
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - Fernando A F Rocha
- Laboratório de Neurofisiologia Eduardo Oswaldo Cruz, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil
| | - Anderson M Herculano
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - José L M do Nascimento
- Laboratório de Neuroquímica Molecular e Celular Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil
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13
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Totino PRR, Daniel-Ribeiro CT, Ferreira-da-Cruz MDF. Evidencing the Role of Erythrocytic Apoptosis in Malarial Anemia. Front Cell Infect Microbiol 2016; 6:176. [PMID: 28018860 PMCID: PMC5145864 DOI: 10.3389/fcimb.2016.00176] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/21/2016] [Indexed: 01/06/2023] Open
Abstract
In the last decade it has become clear that, similarly to nucleated cells, enucleated red blood cells (RBCs) are susceptible to programmed apoptotic cell death. Erythrocytic apoptosis seems to play a role in physiological clearance of aged RBCs, but it may also be implicated in anemia of different etiological sources including drug therapy and infectious diseases. In malaria, severe anemia is a common complication leading to death of children and pregnant women living in malaria-endemic regions of Africa. The pathogenesis of malarial anemia is multifactorial and involves both ineffective production of RBCs by the bone marrow and premature elimination of non-parasitized RBCs, phenomena potentially associated with apoptosis. In the present overview, we discuss evidences associating erythrocytic apoptosis with the pathogenesis of severe malarial anemia, as well as with regulation of parasite clearance in malaria. Efforts to understand the role of erythrocytic apoptosis in malarial anemia can help to identify potential targets for therapeutic intervention based on apoptotic pathways and consequently, mitigate the harmful impact of malaria in global public health.
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Affiliation(s)
- Paulo R R Totino
- Laboratory of Malaria Research, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz Rio de Janeiro, Brazil
| | - Cláudio T Daniel-Ribeiro
- Laboratory of Malaria Research, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz Rio de Janeiro, Brazil
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14
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Apoorv TS, Babu PP. Minocycline prevents cerebral malaria, confers neuroprotection and increases survivability of mice during Plasmodium berghei ANKA infection. Cytokine 2016; 90:113-123. [PMID: 27865203 DOI: 10.1016/j.cyto.2016.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 10/29/2016] [Accepted: 11/05/2016] [Indexed: 11/28/2022]
Abstract
Cerebral malaria (CM) is a neurological complication arising due to Plasmodium falciparum or Plasmodium vivax infection. Minocycline, a semi-synthetic tetracycline, has been earlier reported to have a neuroprotective role in several neurodegenerative diseases. In this study, we investigated the effect of minocycline treatment on the survivability of mice during experimental cerebral malaria (ECM). The currently accepted mouse model, C57BL/6 mice infected with Plasmodium berghei ANKA, was used for the study. Infected mice were treated with an intra-peritoneal dose of minocycline hydrochloride, 45mg/kg daily for ten days that led to parasite clearance in blood, brain, liver and spleen on 7th day post-infection; and the mice survived until experiment ended (90days) without parasite recrudescence. Evans blue extravasation assay showed that blood-brain barrier integrity was maintained by minocycline. The tumor necrosis factor-alpha protein level and caspase activity, which is related to CM pathogenesis, was significantly reduced in the minocycline-treated group. Fluoro-Jade® C and hematoxylin-eosin staining of the brains of minocycline group revealed a decrease in degenerating neurons and absence of hemorrhages respectively. Minocycline treatment led to decrease in gene expressions of inflammatory mediators like interferon-gamma, CXCL10, CCL5, CCL2; receptors CXCR3 and CCR2; and hence decrease in T-cell-mediated cerebral inflammation. We also proved that this reduction in gene expressions is irrespective of the anti-parasitic property of minocycline. The distinct ability of minocycline to modulate gene expressions of CXCL10 and CXCR3 makes it effective than doxycycline, a tetracycline used as chemoprophylaxis. Our study shows that minocycline is highly effective in conferring neuroprotection during ECM.
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Affiliation(s)
- Thittayil Suresh Apoorv
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana State, India
| | - Phanithi Prakash Babu
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500 046, Telangana State, India.
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15
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Alencar-Filho AC, Ferreira JMBB, Salinas JL, Fabbri C, Monteiro WM, Siqueira AM, Okoshi K, Lacerda MVG, Okoshi MP. Cardiovascular changes in patients with non-severe Plasmodium vivax malaria. IJC HEART & VASCULATURE 2016; 11:12-16. [PMID: 28616519 PMCID: PMC5441355 DOI: 10.1016/j.ijcha.2016.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/04/2016] [Indexed: 11/19/2022]
Abstract
Background Cardiovascular system involvement in patients with Plasmodium vivax malaria has been poorly addressed. The aim of this study was to evaluate cardiac structures and function, and serum markers of cardiovascular injury in patients with the non-severe form of vivax malaria in Manaus, Amazonas State, Brazil. Methods and results We prospectively evaluated 26 patients with vivax malaria in an outpatient referral hospital and compared results with a control group of 25 gender- and age-matched healthy individuals. Patients underwent clinical evaluation, laboratory tests, and transthoracic echocardiography at first evaluation (day zero, D0) and seven days (D7) after malaria diagnosis. At D0 echocardiography showed higher left ventricular (LV) systolic diameter (28.8 ± 2.82 vs 30.9 ± 4.03 mm; p = 0.037) and LV diastolic volume (82.4 ± 12.3 vs 93.8 ± 25.9 ml; p = 0.05), and lower LV ejection fraction (Teicholz method: 73.2 ± 6.59 vs 68.4 ± 4.87%; p = 0.004) in patients compared to controls. Right ventricle (RV) fractional area change (54.7 ± 5.11 vs 50.5 ± 6.71%; p = 0.014) was lower, and RV myocardial performance index (0.21 ± 0.07 vs 0.33 ± 0.19; p = 0.007), and pulmonary vascular resistance (1.13 ± 0.25 vs 1.32 ± 0.26 Woods unit; p = 0.012) were higher in patients than controls. Patients presented higher serum levels of unconjugated bilirubin (0.24 ± 0.15 vs 1.30 ± 0.89 mg/dL; p < 0.001), soluble vascular cell adhesion molecule–1 (sVCAM-1; 453 ± 143 vs 1983 ± 880 ng/mL; p < 0.001), N-terminal prohormone brain natriuretic peptide (0.59 ± 0.86 vs 1.08 ± 0.81 pg/mL; p = 0.045), and troponin T (861 ± 338 vs 1037 ± 264 pg/mL; p = 0.045), and lower levels of plasma nitrite (13.42 ± 8.15 vs 8.98 ± 3.97 μM; p = 0.016) than controls. Most alterations had reversed by D7. Conclusion Patients with non-severe Plasmodium vivax malaria present subclinical reversible cardiovascular changes.
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Affiliation(s)
| | | | | | - Camila Fabbri
- North University Center, Pharmacy School, Manaus, Brazil
| | - Wuelton Marcelo Monteiro
- Amazonas State University (UEA), Manaus, Brazil.,Tropical Disease Center "Dr. Heitor Vieira Dourado", Manaus, Brazil
| | - Andre Machado Siqueira
- National Institute of Infectology Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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16
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Yalcin O, Oronsky B, Carvalho LJM, Kuypers FA, Scicinski J, Cabrales P. From METS to malaria: RRx-001, a multi-faceted anticancer agent with activity in cerebral malaria. Malar J 2015; 14:218. [PMID: 26017006 PMCID: PMC4453052 DOI: 10.1186/s12936-015-0720-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 05/04/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The survival of malaria parasites, under substantial haem-induced oxidative stress in the red blood cells (RBCs) is dependent on the pentose phosphate pathway (PPP). The PPP is the only source of NADPH in the RBC, essential for the production of reduced glutathione (GSH) and for protection from oxidative stress. Glucose-6-phosphate dehydrogenase (G6PD) deficiency, therefore, increases the vulnerability of erythrocytes to oxidative stress. In Plasmodium, G6PD is combined with the second enzyme of the PPP to create a unique bifunctional enzyme, named glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase (G6PD-6PGL). RRx-001 is a novel, systemically non-toxic, epigenetic anticancer agent currently in Phase 2 clinical development for multiple tumour types, with activity mediated through increased nitric oxide (NO) production and PPP inhibition. The inhibition of G6PD and NO overproduction induced by RRx-001 suggested its application in cerebral malaria (CM). METHODS Plasmodium berghei ANKA (PbA) infection in C57BL/6 mice is an experimental model of cerebral malaria (ECM) with several similar pathological features to human CM. This study uses intravital microscopy methods with a closed cranial window model to quantify cerebral haemodynamic changes and leukocyte adhesion to endothelial cells in ECM. RESULTS RRx-001 had both single agent anti-parasitic activity and significantly increased the efficacy of artemether. In addition, RRx-001 preserved cerebral perfusion and reduced inflammation alone or combined with artemether. RRx-001's effects were associated with inhibition of PPP (G6PD and G6PD-6PGL) and by improvements in microcirculatory flow, which may be related to the NO donating properties of RRx-001. CONCLUSION The results indicate that RRx-001 could be used to potentiate the anti-malarial action of artemisinin, particularly on resistant strains, and to prevent infection.
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Affiliation(s)
- Ozlem Yalcin
- Department of Bioengineering, University of California, 9500 Gilman Dr., La Jolla, San Diego, CA, 92093-0412, USA.
- School of Medicine, Koç University, Sariyer, Istanbul, Turkey.
| | | | - Leonardo J M Carvalho
- Center for Malaria Research, La Jolla Bioengineering Institute, San Diego, CA, USA.
- Laboratory of Malaria Research, Oswaldo Cruz Institute, Fiocruz, Rio de Janeiro, Brazil.
| | - Frans A Kuypers
- Children's Hospital Oakland Research Institute, Oakland, CA, USA.
| | | | - Pedro Cabrales
- Department of Bioengineering, University of California, 9500 Gilman Dr., La Jolla, San Diego, CA, 92093-0412, USA.
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17
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Involvement of Nod2 in the innate immune response elicited by malarial pigment hemozoin. Microbes Infect 2014; 17:184-94. [PMID: 25462568 DOI: 10.1016/j.micinf.2014.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 10/15/2014] [Accepted: 11/11/2014] [Indexed: 02/07/2023]
Abstract
In malaria, the evidence concerning the nucleotide-binding, oligomerization domain (NOD) 2 (NOD2) receptor is fragmented and the stimuli that might activate NOD2 are not well characterized. We investigated the role of NOD2 in vitro in the response of macrophages to Plasmodium falciparum products. Immortalized or primary bone marrow derived macrophages from wild type C57Bl/6 mice, or knockout mice for NOD2 or its adaptor proteins, were either primed with interferon gamma or left untreated, and stimulated with parasite products. Both lysates of infected erythrocytes or hemozoin induced higher levels of nitric oxide in primed than in unprimed wild type macrophages. When stimulated with hemozoin, primed macrophages knockout for NOD2, or for its adaptor proteins, produced significantly lower nitric oxide levels compared to wild type cells. Differently from hemozoin, the use of β-hematin (synthetic hemozoin) as stimulus showed that NOD2 is dispensable. Furthermore, the production of inflammatory cytokines by wild type cells treated with hemozoin was not dependent on NOD2. These data indicate that parasite components present in the hemozoin, differently from β-hematin, induce the production of nitric oxide through the activation of NOD2, whereas the production of inflammatory cytokines, like TNF-α or MIP-2 (CXCL2), seems to be NOD2 independent.
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18
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Totino PRR, Pinna RA, Oliveira ACAXD, Banic DM, Daniel-Ribeiro CT, Ferreira-da-Cruz MDF. Apoptosis of non-parasitised red blood cells in Plasmodium yoelii malaria. Mem Inst Oswaldo Cruz 2014; 108:686-90. [PMID: 24037189 PMCID: PMC3970687 DOI: 10.1590/0074-0276108062013003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/03/2013] [Indexed: 11/22/2022] Open
Abstract
Recently, while studying erythrocytic apoptosis during Plasmodium
yoelii infection, we observed an increase in the levels of
non-parasitised red blood cell (nRBC) apoptosis, which could be related to
malarial anaemia. Therefore, in the present study, we attempted to investigate
whether nRBC apoptosis is associated with the peripheral RBC count, parasite
load or immune response. To this end, BALB/c mice were infected with P.
yoelii 17XL and nRBC apoptosis, number of peripheral RBCs,
parasitaemia and plasmatic levels of cytokines, nitric oxide and anti-RBC
antibodies were evaluated at the early and late stages of anaemia. The apoptosis
of nRBCs increased at the late stage and was associated with parasitaemia, but
not with the intensity of the immune response. The increased percentage of nRBC
apoptosis that was observed when anaemia was accentuated was not related to a
reduction in peripheral RBCs. We conclude that nRBC apoptosis in P.
yoelii malaria appears to be induced in response to a high parasite
load. Further studies on malaria models in which acute anaemia develops during
low parasitaemia are needed to identify the potential pathogenic role of nRBC
apoptosis.
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Affiliation(s)
- Paulo Renato Rivas Totino
- Laboratório de Pesquisas em Malária, Escola Nacional de Saúde Pública, Fiocruz, Rio de JaneiroRJ, Brasil
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19
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Polimeni M, Prato M. Host matrix metalloproteinases in cerebral malaria: new kids on the block against blood-brain barrier integrity? Fluids Barriers CNS 2014; 11:1. [PMID: 24467887 PMCID: PMC3905658 DOI: 10.1186/2045-8118-11-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 01/24/2014] [Indexed: 12/23/2022] Open
Abstract
Cerebral malaria (CM) is a life-threatening complication of falciparum malaria, associated with high mortality rates, as well as neurological impairment in surviving patients. Despite disease severity, the etiology of CM remains elusive. Interestingly, although the Plasmodium parasite is sequestered in cerebral microvessels, it does not enter the brain parenchyma: so how does Plasmodium induce neuronal dysfunction? Several independent research groups have suggested a mechanism in which increased blood–brain barrier (BBB) permeability might allow toxic molecules from the parasite or the host to enter the brain. However, the reported severity of BBB damage in CM is variable depending on the model system, ranging from mild impairment to full BBB breakdown. Moreover, the factors responsible for increased BBB permeability are still unknown. Here we review the prevailing theories on CM pathophysiology and discuss new evidence from animal and human CM models implicating BBB damage. Finally, we will review the newly-described role of matrix metalloproteinases (MMPs) and BBB integrity. MMPs comprise a family of proteolytic enzymes involved in modulating inflammatory response, disrupting tight junctions, and degrading sub-endothelial basal lamina. As such, MMPs represent potential innovative drug targets for CM.
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Affiliation(s)
| | - Mauro Prato
- Dipartimento di Neuroscienze, Università di Torino, C,so Raffaello 30, 10125 Torino, Italy.
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20
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NOS2 variants reveal a dual genetic control of nitric oxide levels, susceptibility to Plasmodium infection, and cerebral malaria. Infect Immun 2013; 82:1287-95. [PMID: 24379293 DOI: 10.1128/iai.01070-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Nitric oxide (NO) is a proposed component of malaria pathogenesis, and the inducible nitric oxide synthase gene (NOS2) has been associated to malaria susceptibility. We analyzed the role of NOS2 polymorphisms on NO bioavailability and on susceptibility to infection, Plasmodium carrier status and clinical malaria. Two distinct West African sample collections were studied: a population-based collection of 1,168 apparently healthy individuals from the Príncipe Island and a hospital-based cohort of 269 Angolan children. We found that two NOS2 promoter single-nucleotide polymorphism (SNP) alleles associated to low NO plasma levels in noninfected individuals were also associated to reduced risk of pre-erythrocytic infection as measured anti-CSP antibody levels (6.25E-04 < P < 7.57E-04). In contrast, three SNP alleles within the NOS2 cistronic region conferring increased NO plasma levels in asymptomatic carriers were strongly associated to risk of parasite carriage (8.00E-05 < P < 7.90E-04). Notwithstanding, three SNP alleles in this region protected from cerebral malaria (7.90E-4 < P < 4.33E-02). Cohesively, the results revealed a dual regimen in the genetic control of NO bioavailability afforded by NOS2 depending on the infection status. NOS2 promoter variants operate in noninfected individuals to decrease both NO bioavailability and susceptibility to pre-erythrocytic infection. Conversely, NOS2 cistronic variants (namely, rs6505469) operate in infected individuals to increase NO bioavailability and confer increased susceptibility to unapparent infection but protect from cerebral malaria. These findings corroborate the hypothesis that NO anti-inflammatory properties impact on different steps of malaria pathogenesis, explicitly by favoring infection susceptibility and deterring severe malaria syndromes.
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21
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Helms C, Kim-Shapiro DB. Hemoglobin-mediated nitric oxide signaling. Free Radic Biol Med 2013; 61:464-72. [PMID: 23624304 PMCID: PMC3849136 DOI: 10.1016/j.freeradbiomed.2013.04.028] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 04/17/2013] [Accepted: 04/17/2013] [Indexed: 02/07/2023]
Abstract
The rate that hemoglobin reacts with nitric oxide (NO) is limited by how fast NO can diffuse into the heme pocket. The reaction is as fast as any ligand/protein reaction can be and the result, when hemoglobin is in its oxygenated form, is formation of nitrate in what is known as the dioxygenation reaction. As nitrate, at the concentrations made through the dioxygenation reaction, is biologically inert, the only role hemoglobin was once thought to play in NO signaling was to inhibit it. However, there are now several mechanisms that have been discovered by which hemoglobin may preserve, control, and even create NO activity. These mechanisms involve compartmentalization of reacting species and conversion of NO from or into other species such as nitrosothiols or nitrite which could transport NO activity. Despite the tremendous amount of work devoted to this field, major questions concerning precise mechanisms of NO activity preservation as well as if and how Hb creates NO activity remain unanswered.
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Affiliation(s)
- Christine Helms
- Department of Physics and Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Daniel B Kim-Shapiro
- Department of Physics and Translational Science Center, Wake Forest University, Winston-Salem, NC 27109, USA.
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22
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Jain K, Sood S, Gowthamarajan K. Modulation of cerebral malaria by curcumin as an adjunctive therapy. Braz J Infect Dis 2013; 17:579-91. [PMID: 23906771 PMCID: PMC9425129 DOI: 10.1016/j.bjid.2013.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 03/20/2013] [Accepted: 03/21/2013] [Indexed: 12/31/2022] Open
Abstract
Cerebral malaria is the most severe and rapidly fatal neurological complication of Plasmodium falciparum infection and responsible for more than two million deaths annually. The current therapy is inadequate in terms of reducing mortality or post-treatment symptoms such as neurological and cognitive deficits. The pathophysiology of cerebral malaria is quite complex and offers a variety of targets which remain to be exploited for better therapeutic outcome. The present review discusses on the pathophysiology of cerebral malaria with particular emphasis on scope and promises of curcumin as an adjunctive therapy to improve survival and overcome neurological deficits.
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Affiliation(s)
- Kunal Jain
- Department of Pharmaceutics, J.S.S. College of Pharmacy, Udhagamandalam, Tamilnadu 643001, India.
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Mita-Mendoza NK, van de Hoef DL, Lopera-Mesa TM, Doumbia S, Konate D, Doumbouya M, Gu W, Anderson JM, Santos-Argumedo L, Rodriguez A, Fay MP, Diakite M, Long CA, Fairhurst RM. A potential role for plasma uric acid in the endothelial pathology of Plasmodium falciparum malaria. PLoS One 2013; 8:e54481. [PMID: 23349902 PMCID: PMC3551755 DOI: 10.1371/journal.pone.0054481] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 12/12/2012] [Indexed: 12/13/2022] Open
Abstract
Background Inflammatory cytokinemia and systemic activation of the microvascular endothelium are central to the pathogenesis of Plasmodium falciparum malaria. Recently, ‘parasite-derived’ uric acid (UA) was shown to activate human immune cells in vitro, and plasma UA levels were associated with inflammatory cytokine levels and disease severity in Malian children with malaria. Since UA is associated with endothelial inflammation in non-malaria diseases, we hypothesized that elevated UA levels contribute to the endothelial pathology of P. falciparum malaria. Methodology/Principal Findings We measured levels of UA and soluble forms of intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sE-Selectin), thrombomodulin (sTM), tissue factor (sTF) and vascular endothelial growth factor (VEGF) in the plasma of Malian children aged 0.5–17 years with uncomplicated malaria (UM, n = 487) and non-cerebral severe malaria (NCSM, n = 68). In 69 of these children, we measured these same factors once when they experienced a malaria episode and twice when they were healthy (i.e., before and after the malaria transmission season). We found that levels of UA, sICAM-1, sVCAM-1, sE-Selectin and sTM increase during a malaria episode and return to basal levels at the end of the transmission season (p<0.0001). Plasma levels of UA and these four endothelial biomarkers correlate with parasite density and disease severity. In children with UM, UA levels correlate with parasite density (r = 0.092, p = 0.043), sICAM-1 (r = 0.255, p<0.0001) and sTM (r = 0.175, p = 0.0001) levels. After adjusting for parasite density, UA levels predict sTM levels. Conclusions/Significance Elevated UA levels may contribute to malaria pathogenesis by damaging endothelium and promoting a procoagulant state. The correlation between UA levels and parasite densities suggests that parasitized erythrocytes are one possible source of excess UA. UA-induced shedding of endothelial TM may represent a novel mechanism of malaria pathogenesis, in which activated thrombin induces fibrin deposition and platelet aggregation in microvessels. This protocol is registered at clinicaltrials.gov (NCT00669084).
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Affiliation(s)
- Neida K. Mita-Mendoza
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Departmento de Biomedicina Molecular, Centro de Investigaciόn y Estudios Avanzados – Instituto Politécnico Nacional, Ciudad de México, México
| | - Diana L. van de Hoef
- Department of Microbiology, Division of Parasitology, NYU School of Medicine, New York, New York, United States of America
| | - Tatiana M. Lopera-Mesa
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Saibou Doumbia
- Malaria Research and Training Center, Faculty of Medicine, Pharmacy and Odontostomatology, University of Bamako, Bamako, Mali
| | - Drissa Konate
- Malaria Research and Training Center, Faculty of Medicine, Pharmacy and Odontostomatology, University of Bamako, Bamako, Mali
| | - Mory Doumbouya
- Malaria Research and Training Center, Faculty of Medicine, Pharmacy and Odontostomatology, University of Bamako, Bamako, Mali
| | - Wenjuan Gu
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jennifer M. Anderson
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Leopoldo Santos-Argumedo
- Departmento de Biomedicina Molecular, Centro de Investigaciόn y Estudios Avanzados – Instituto Politécnico Nacional, Ciudad de México, México
| | - Ana Rodriguez
- Department of Microbiology, Division of Parasitology, NYU School of Medicine, New York, New York, United States of America
| | - Michael P. Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Mahamadou Diakite
- Malaria Research and Training Center, Faculty of Medicine, Pharmacy and Odontostomatology, University of Bamako, Bamako, Mali
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail:
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Huang H, Ji H, Li H, Jing Q, Labby KJ, Martásek P, Roman LJ, Poulos TL, Silverman RB. Selective monocationic inhibitors of neuronal nitric oxide synthase. Binding mode insights from molecular dynamics simulations. J Am Chem Soc 2012; 134:11559-72. [PMID: 22731813 DOI: 10.1021/ja302269r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The reduction of pathophysiologic levels of nitric oxide through inhibition of neuronal nitric oxide synthase (nNOS) has the potential to be therapeutically beneficial in various neurodegenerative diseases. We have developed a series of pyrrolidine-based nNOS inhibitors that exhibit excellent potencies and isoform selectivities (J. Am. Chem. Soc. 2010, 132, 5437). However, there are still important challenges, such as how to decrease the multiple positive charges derived from basic amino groups, which contribute to poor bioavailability, without losing potency and/or selectivity. Here we present an interdisciplinary study combining molecular docking, crystallography, molecular dynamics simulations, synthesis, and enzymology to explore potential pharmacophoric features of nNOS inhibitors and to design potent and selective monocationic nNOS inhibitors. The simulation results indicate that different hydrogen bond patterns, electrostatic interactions, hydrophobic interactions, and a water molecule bridge are key factors for stabilizing ligands and controlling ligand orientation. We find that a heteroatom in the aromatic head or linker chain of the ligand provides additional stability and blocks the substrate binding pocket. Finally, the computational insights are experimentally validated with double-headed pyridine analogues. The compounds reported here are among the most potent and selective monocationic pyrrolidine-based nNOS inhibitors reported to date, and 10 shows improved membrane permeability.
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Affiliation(s)
- He Huang
- Department of Chemistry, Chemistry of Life Processes Institute, amd Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
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25
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Nitric oxide level, protein oxidation and antioxidant enzymes in rats infected by Trypanosoma evansi. Exp Parasitol 2012; 132:166-70. [PMID: 22771866 DOI: 10.1016/j.exppara.2012.06.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 05/30/2012] [Accepted: 06/26/2012] [Indexed: 11/22/2022]
Abstract
The aim of this study was to evaluate the nitric oxide (NO()) level, protein oxidation and antioxidant enzymes in rats infected with Trypanosoma evansi and establish the association of NO() levels with the degree of parasitemia. Thirty-six male rats (Wistar) were divided into two groups with 18 animals each. Group A was not infected while Group B was intraperitoneally infected, receiving 7.5×10(6) trypomastigotes per animal. Each group was divided into three subgroups with 6 rats each and blood was collected during different periods post-infection (PI), as follows: day 5 (A(5) and B(5)), day 15 (A(15) and B(15)) and day 30 PI (A(30) and B(30)). Blood samples were collected by cardiac puncture to estimate the levels of nitrites/nitrates (NO(x)) and advanced oxidation protein products (AOPP) in serum, and superoxide dismutase (SOD) and catalase (CAT) activities in blood. On days 15 and 30 PI NO(x) and AOPP levels were increased in serum of rats infected. Rodents infected with T. evansi showed a significant increase in SOD (days 5 and 15 PI) and CAT (day 30 PI) activities. Based on the physiological role of NO(), we can conclude that its increased concentration is related to an inflammatory response against the parasite, once a redox imbalance was observed during infection.
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26
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Oxidant/antioxidant balance and trace elements status in sheep with liver cystic echinococcosis. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s00580-012-1523-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Bagnaresi P, Barros NM, Assis DM, Melo PM, Fonseca RG, Juliano MA, Pesquero JB, Juliano L, Rosenthal PJ, Carmona AK, Gazarini ML. Intracellular proteolysis of kininogen by malaria parasites promotes release of active kinins. Malar J 2012; 11:156. [PMID: 22564457 PMCID: PMC3407703 DOI: 10.1186/1475-2875-11-156] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/07/2012] [Indexed: 01/22/2023] Open
Abstract
Background The malaria burden remains a major public health concern, especially in sub-Saharan Africa. The complex biology of Plasmodium, the apicomplexan parasite responsible for this disease, challenges efforts to develop new strategies to control the disease. Proteolysis is a fundamental process in the metabolism of malaria parasites, but roles for proteases in generating vasoactive peptides have not previously been explored. Results In the present work, it was demonstrated by mass spectrometry analysis that Plasmodium parasites (Plasmodium chabaudi and Plasmodium falciparum) internalize and process plasma kininogen, thereby releasing vasoactive kinins (Lys-BK, BK and des-Arg9-BK) that may mediate haemodynamic alterations during acute malaria. In addition, it was demonstrated that the P. falciparum cysteine proteases falcipain-2 and falcipain-3 generated kinins after incubation with human kininogen, suggesting that these enzymes have an important role in this process. The biologic activity of peptides released by Plasmodium parasites was observed by measuring ileum contraction and activation of kinin receptors (B1 and B2) in HUVEC cells; the peptides elicited an increase in intracellular calcium, measured by Fluo-3 AM fluorescence. This effect was suppressed by the specific receptor antagonists Des-Arg9[Leu8]-BK and HOE-140. Conclusions In previously undescribed means of modulating host physiology, it was demonstrated that malaria parasites can generate active kinins by proteolysis of plasma kininogen.
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Affiliation(s)
- Piero Bagnaresi
- Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo, 669 - 7 andar, 04039-032, São Paulo, Brazil
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Oxidative and Nitrosative Stress on Phagocytes’ Function: from Effective Defense to Immunity Evasion Mechanisms. Arch Immunol Ther Exp (Warsz) 2011; 59:441-8. [DOI: 10.1007/s00005-011-0144-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 06/27/2011] [Indexed: 12/12/2022]
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Hawkes M, Opoka RO, Namasopo S, Miller C, Conroy AL, Serghides L, Kim H, Thampi N, Liles WC, John CC, Kain KC. Nitric oxide for the adjunctive treatment of severe malaria: hypothesis and rationale. Med Hypotheses 2011; 77:437-44. [PMID: 21745716 PMCID: PMC3162048 DOI: 10.1016/j.mehy.2011.06.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 06/07/2011] [Indexed: 11/24/2022]
Abstract
We hypothesize that supplemental inhaled nitric oxide (iNO) will improve outcomes in children with severe malaria receiving standard antimalarial therapy. The rationale for the hypothesized efficacy of iNO rests on: (1) biological plausibility, based on known actions of NO in modulating endothelial activation; (2) pre-clinical efficacy data from animal models of experimental cerebral malaria; and (3) a human trial of the NO precursor l-arginine, which improved endothelial function in adults with severe malaria. iNO is an attractive new candidate for the adjunctive treatment of severe malaria, given its proven therapeutic efficacy in animal studies, track record of safety in clinical practice and numerous clinical trials, inexpensive manufacturing costs, and ease of administration in settings with limited healthcare infrastructure. We plan to test this hypothesis in a randomized controlled trial (ClinicalTrials.gov Identifier: NCT01255215).
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Affiliation(s)
- Michael Hawkes
- Sandra A. Rotman Laboratories, McLaughlin-Rotman Centre for Global Health, Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
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30
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Hawkes M, Opoka RO, Namasopo S, Miller C, Thorpe KE, Lavery JV, Conroy AL, Liles WC, John CC, Kain KC. Inhaled nitric oxide for the adjunctive therapy of severe malaria: protocol for a randomized controlled trial. Trials 2011; 12:176. [PMID: 21752262 PMCID: PMC3151218 DOI: 10.1186/1745-6215-12-176] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 07/13/2011] [Indexed: 12/22/2022] Open
Abstract
Background Severe malaria remains a major cause of global morbidity and mortality. Despite the use of potent anti-parasitic agents, the mortality rate in severe malaria remains high. Adjunctive therapies that target the underlying pathophysiology of severe malaria may further reduce morbidity and mortality. Endothelial activation plays a central role in the pathogenesis of severe malaria, of which angiopoietin-2 (Ang-2) has recently been shown to function as a key regulator. Nitric oxide (NO) is a major inhibitor of Ang-2 release from endothelium and has been shown to decrease endothelial inflammation and reduce the adhesion of parasitized erythrocytes. Low-flow inhaled nitric oxide (iNO) gas is a US FDA-approved treatment for hypoxic respiratory failure in neonates. Methods/Design This prospective, parallel arm, randomized, placebo-controlled, blinded clinical trial compares adjunctive continuous inhaled nitric oxide at 80 ppm to placebo (both arms receiving standard anti-malarial therapy), among Ugandan children aged 1-10 years of age with severe malaria. The primary endpoint is the longitudinal change in Ang-2, an objective and quantitative biomarker of malaria severity, which will be analysed using a mixed-effects linear model. Secondary endpoints include mortality, recovery time, parasite clearance and neurocognitive sequelae. Discussion Noteworthy aspects of this trial design include its efficient sample size supported by a computer simulation study to evaluate statistical power, meticulous attention to complex ethical issues in a cross-cultural setting, and innovative strategies for safety monitoring and blinding to treatment allocation in a resource-constrained setting in sub-Saharan Africa. Trial Registration ClinicalTrials.gov Identifier: NCT01255215
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Affiliation(s)
- Michael Hawkes
- Institute of Medical Sciences, University of Toronto, Canada
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31
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Bertinaria M, Guglielmo S, Rolando B, Giorgis M, Aragno C, Fruttero R, Gasco A, Parapini S, Taramelli D, Martins YC, Carvalho LJ. Amodiaquine analogues containing NO-donor substructures: Synthesis and their preliminary evaluation as potential tools in the treatment of cerebral malaria. Eur J Med Chem 2011; 46:1757-67. [DOI: 10.1016/j.ejmech.2011.02.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 02/10/2011] [Accepted: 02/11/2011] [Indexed: 12/31/2022]
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32
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Taoufiq Z, Pino P, N'dilimabaka N, Arrouss I, Assi S, Soubrier F, Rebollo A, Mazier D. Atorvastatin prevents Plasmodium falciparum cytoadherence and endothelial damage. Malar J 2011; 10:52. [PMID: 21356073 PMCID: PMC3056843 DOI: 10.1186/1475-2875-10-52] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 02/28/2011] [Indexed: 12/29/2022] Open
Abstract
Background The adhesion of Plasmodium falciparum parasitized red blood cell (PRBC) to human endothelial cells (EC) induces inflammatory processes, coagulation cascades, oxidative stress and apoptosis. These pathological processes are suspected to be responsible for the blood-brain-barrier and other organs' endothelial dysfunctions observed in fatal cases of malaria. Atorvastatin, a drug that belongs to the lowering cholesterol molecule family of statins, has been shown to ameliorate endothelial functions and is widely used in patients with cardiovascular disorders. Methods The effect of this compound on PRBC induced endothelial impairments was assessed using endothelial co-culture models. Results Atorvastatin pre-treatment of EC was found to reduce the expression of adhesion molecules and P. falciparum cytoadherence, to protect cells against PRBC-induced apoptosis and to enhance endothelial monolayer integrity during co-incubation with parasites. Conclusions These results might suggest a potential interest use of atorvastatin as a protective treatment to interfere with the pathophysiological cascades leading to severe malaria.
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Affiliation(s)
- Zacharie Taoufiq
- INSERM, UMR S945, Université Pierre et Marie Curie-Paris 6, CHU-Pitié-Salpêtrière, 91 bd de l'Hôpital, 75013 Paris, France.
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Ali M, Al-Olayan EM, Lewis S, Matthews H, Hurd H. Naturally occurring triggers that induce apoptosis-like programmed cell death in Plasmodium berghei ookinetes. PLoS One 2010; 5. [PMID: 20844583 PMCID: PMC2936559 DOI: 10.1371/journal.pone.0012634] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Accepted: 08/10/2010] [Indexed: 01/01/2023] Open
Abstract
Several protozoan parasites have been shown to undergo a form of programmed cell death that exhibits morphological features associated with metazoan apoptosis. These include the rodent malaria parasite, Plasmodium berghei. Malaria zygotes develop in the mosquito midgut lumen, forming motile ookinetes. Up to 50% of these exhibit phenotypic markers of apoptosis; as do those grown in culture. We hypothesised that naturally occurring signals induce many ookinetes to undergo apoptosis before midgut traversal. To determine whether nitric oxide and reactive oxygen species act as such triggers, ookinetes were cultured with donors of these molecules. Exposure to the nitric oxide donor SNP induced a significant increase in ookinetes with condensed nuclear chromatin, activated caspase-like molecules and translocation of phosphatidylserine that was dose and time related. Results from an assay that detects the potential-dependent accumulation of aggregates of JC-1 in mitochondria suggested that nitric oxide does not operate via loss of mitochondrial membrane potential. L-DOPA (reactive oxygen species donor) also caused apoptosis in a dose and time dependent manner. Removal of white blood cells significantly decreased ookinetes exhibiting a marker of apoptosis in vitro. Inhibition of the activity of nitric oxide synthase in the mosquito midgut epithelium using L-NAME significantly decreased the proportion of apoptotic ookinetes and increased the number of oocysts that developed. Introduction of a nitric oxide donor into the blood meal had no effect on mosquito longevity but did reduce prevalence and intensity of infection. Thus, nitric oxide and reactive oxygen species are triggers of apoptosis in Plasmodium ookinetes. They occur naturally in the mosquito midgut lumen, sourced from infected blood and mosquito tissue. Up regulation of mosquito nitric oxide synthase activity has potential as a transmission blocking strategy.
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Affiliation(s)
- Medhat Ali
- School of Life Sciences, Keele University, Keele, United Kingdom
- Department of Zoology, Ain Shams University, Cairo, Egypt
| | - Ebtesam M. Al-Olayan
- School of Life Sciences, Keele University, Keele, United Kingdom
- Department of Zoology, King Saud University, Riyadh, Saudi Arabia
| | - Steven Lewis
- School of Life Sciences, Keele University, Keele, United Kingdom
| | - Holly Matthews
- School of Life Sciences, Keele University, Keele, United Kingdom
| | - Hilary Hurd
- School of Life Sciences, Keele University, Keele, United Kingdom
- * E-mail:
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de Matos Macchi B, Quaresma JAS, Herculano AM, Crespo-López ME, DaMatta RA, do Nascimento JLM. Pathogenic action of Plasmodium gallinaceum in chickens: Brain histology and nitric oxide production by blood monocyte-derived macrophages. Vet Parasitol 2010; 172:16-22. [DOI: 10.1016/j.vetpar.2010.04.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 04/13/2010] [Accepted: 04/27/2010] [Indexed: 11/29/2022]
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A new allele (eNOS4e) in the intron 4 (VNTR) of eNOS gene in malaria infected individuals of the population of Orissa (an eastern Indian state). Nitric Oxide 2010; 22:58-9. [DOI: 10.1016/j.niox.2009.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 11/20/2009] [Accepted: 11/23/2009] [Indexed: 11/19/2022]
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36
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Morita H, Tomizawa Y, Deguchi J, Ishikawa T, Arai H, Zaima K, Hosoya T, Hirasawa Y, Matsumoto T, Kamata K. Synthesis and structure–activity relationships of cassiarin A as potential antimalarials with vasorelaxant activity. Bioorg Med Chem 2009; 17:8234-40. [DOI: 10.1016/j.bmc.2009.10.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 10/06/2009] [Accepted: 10/07/2009] [Indexed: 10/20/2022]
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Hammerschmidt K, Kurtz J. Ecological immunology of a tapeworms' interaction with its two consecutive hosts. ADVANCES IN PARASITOLOGY 2009; 68:111-37. [PMID: 19289192 DOI: 10.1016/s0065-308x(08)00605-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Host-parasite interactions in parasites with complex life cycles have recently gained much interest. Here, we take an evolutionary ecologist's perspective and analyse the immunological interaction of such a parasite, the model tapeworm Schistocephalus solidus, with its two intermediate hosts, a cyclopoid copepod and the three-spined stickleback. We will be focussing especially on the parallel links between the different phases during an infection in the different hosts; the immunological interactions between host(s) and parasite; and their impact on parasite establishment, growth, host manipulation and parasite virulence in the next host in the cycle. We propose to extend the 'extended phenotype' concept and not only include the ultimate but also the proximate, physiological causes. In particular, parasite-induced host manipulation is suggested to be caused by the interactions of the parasite with the hosts' immune systems.
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Affiliation(s)
- Katrin Hammerschmidt
- Department of Animal and Plant Sciences, The University of Sheffield, Sheffield, United Kingdom
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Olszewski KL, Morrisey JM, Wilinski D, Burns JM, Vaidya AB, Rabinowitz JD, Llinás M. Host-parasite interactions revealed by Plasmodium falciparum metabolomics. Cell Host Microbe 2009; 5:191-9. [PMID: 19218089 DOI: 10.1016/j.chom.2009.01.004] [Citation(s) in RCA: 207] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 12/19/2008] [Accepted: 01/22/2009] [Indexed: 01/25/2023]
Abstract
Intracellular pathogens have devised mechanisms to exploit their host cells to ensure their survival and replication. The malaria parasite Plasmodium falciparum relies on an exchange of metabolites with the host for proliferation. Here we describe a mass spectrometry-based metabolomic analysis of the parasite throughout its 48 hr intraerythrocytic developmental cycle. Our results reveal a general modulation of metabolite levels by the parasite, with numerous metabolites varying in phase with the developmental cycle. Others differed from uninfected cells irrespective of the developmental stage. Among these was extracellular arginine, which was specifically converted to ornithine by the parasite. To identify the biochemical basis for this effect, we disrupted the plasmodium arginase gene in the rodent malaria model P. berghei. These parasites were viable but did not convert arginine to ornithine. Our results suggest that systemic arginine depletion by the parasite may be a factor in human malarial hypoargininemia associated with cerebral malaria pathogenesis.
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Affiliation(s)
- Kellen L Olszewski
- Department of Molecular Biology, 2Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
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Araujo CF, Lacerda MVG, Abdalla DSP, Lima ES. The role of platelet and plasma markers of antioxidant status and oxidative stress in thrombocytopenia among patients with vivax malaria. Mem Inst Oswaldo Cruz 2008; 103:517-21. [DOI: 10.1590/s0074-02762008000600001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 09/08/2008] [Indexed: 11/22/2022] Open
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He X, Azarov I, Jeffers A, Presley T, Richardson J, King SB, Gladwin MT, Kim-Shapiro DB. The potential of Angeli's salt to decrease nitric oxide scavenging by plasma hemoglobin. Free Radic Biol Med 2008; 44:1420-32. [PMID: 18243145 PMCID: PMC2376831 DOI: 10.1016/j.freeradbiomed.2007.12.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 12/21/2007] [Accepted: 12/21/2007] [Indexed: 10/22/2022]
Abstract
Release of hemoglobin from the erythrocyte during intravascular hemolysis contributes to the pathology of a variety of diseased states. This effect is partially due to the enhanced ability of cell-free plasma hemoglobin, which is primarily found in the ferrous, oxygenated state, to scavenge nitric oxide. Oxidation of the cell-free hemoglobin to methemoglobin, which does not effectively scavenge nitric oxide, using inhaled nitric oxide has been shown to be effective in limiting pulmonary and systemic vasoconstriction. However, the ferric heme species may be reduced back to ferrous hemoglobin in plasma and has the potential to drive injurious redox chemistry. We propose that compounds that selectively convert cell-free hemoglobin to ferric, and ideally iron-nitrosylated heme species that do not actively scavenge nitric oxide, would effectively treat intravascular hemolysis. We show here that nitroxyl generated by Angeli's salt (sodium alpha-oxyhyponitrite, Na2N2O3) preferentially reacts with cell-free hemoglobin compared to that encapsulated in the red blood cell under physiologically relevant conditions. Nitroxyl oxidizes oxygenated ferrous hemoglobin to methemoglobin and can convert the methemoglobin to a more stable, less toxic species, iron-nitrosyl hemoglobin. These results support the notion that Angeli's salt or a similar compound could be used to effectively treat conditions associated with intravascular hemolysis.
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Affiliation(s)
- Xiaojun He
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109
| | - Ivan Azarov
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109
| | - Anne Jeffers
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109
| | - Tennille Presley
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109
| | - Jodi Richardson
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109
| | - S. Bruce King
- Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109
| | - Mark T. Gladwin
- Vascular Medicine Branch, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892
- Critical Care Medicine Department, Clinical Center; NIH, Bethesda, MD 20892
| | - Daniel B. Kim-Shapiro
- Vascular Medicine Branch, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892
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Hernandez-Valladares M, Naessens J, Iraqi FA. Gene-knockout mice in malaria research: useful or misleading? Trends Parasitol 2007; 23:522-6. [PMID: 17951110 DOI: 10.1016/j.pt.2007.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 08/22/2007] [Accepted: 08/22/2007] [Indexed: 10/22/2022]
Abstract
Gene-knockout mice have been extensively used in the study of several malaria-induced pathologies. Some investigators believe that the deficient, infected mice mimic disease aspects produced in the absence of the target gene, but others believe that the deficient mice models mainly explain the effects of compensatory, related molecules. Comparison of some of the most relevant knockout mouse studies for understanding cerebral malaria and parasitemia and their related human reports shows that gene-knockout mice are useful tools that support conclusions from human genetic studies. These mice have helped to indicate new resistance genes against human malaria and have provided valuable information about mechanisms of malaria resistance in mice.
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Malarial pigment haemozoin, IFN-gamma, TNF-alpha, IL-1beta and LPS do not stimulate expression of inducible nitric oxide synthase and production of nitric oxide in immuno-purified human monocytes. Malar J 2007; 6:73. [PMID: 17543124 PMCID: PMC1904226 DOI: 10.1186/1475-2875-6-73] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Accepted: 06/02/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Enhanced production of nitric oxide (NO) following upmodulation of the inducible isoform of NO synthase (iNOS) by haemozoin (HZ), inflammatory cytokines and LPS may provide protection against Plasmodium falciparum malaria by killing hepatic and blood forms of parasites and inhibiting the cytoadherence of parasitized erythrocytes (RBC) to endothelial cells. Monocytes and macrophages are considered to contribute importantly to protective upregulation of iNOS and production of NO. Data obtained with murine phagocytes fed with human HZ and synthetic HZ (sHZ) indicate that supplemental treatment of those cells with IFN-gamma elicited significant increases in protein and mRNA expression of iNOS and NO production, providing a potential mechanism linking HZ phagocytosis and increased production of NO. Purpose of this study was to analyse the effect of P. falciparum HZ and sHZ supplemental to treatment with IFN-gamma and/or a stimulatory cytokine-LPS mix on iNOS protein and mRNA expression in immuno-purified human monocytes. METHODS Adherent immunopurified human monocytes (purity >85%), and murine phagocytic cell lines RAW 264.7, N11 and ANA1 were fed or not with P. falciparum HZ or sHZ and treated or not with IFN-gamma or a stimulatory cytokine-LPS mix. Production of NO was quantified in supernatants, iNOS protein and mRNA expression were measured after immunoprecipitation and Western blotting and quantitative RT-PCT, respectively. RESULTS Phagocytosis of HZ/sHZ by human monocytes did not increase iNOS protein and mRNA expression and NO production either after stimulation by IFN-gamma or the cytokine-LPS mix. By contrast, in HZ/sHZ-laden murine macrophages, identical treatment with IFN-gamma and the cytokine-LPS mix elicited significant increases in protein and mRNA expression of iNOS and NOS metabolites production, in agreement with literature data. CONCLUSION Results indicate that human monocytes fed or not with HZ/sHZ were constantly unable to express iNOS and generate NOS metabolites even after stimulation with IFN-gamma or a cytokine-LSP mix that were very active on HZ-fed murine phagocytic lines. Present data do not support the hypothesis that monocytes are mediators of anti-parasitic defence in clinical malaria via activation of iNOS and production of NO, and suggest caution in extrapolating data obtained with murine or hybrid systems to human malaria.
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Gramaglia I, Sobolewski P, Meays D, Contreras R, Nolan JP, Frangos JA, Intaglietta M, van der Heyde HC. Low nitric oxide bioavailability contributes to the genesis of experimental cerebral malaria. Nat Med 2006; 12:1417-22. [PMID: 17099710 DOI: 10.1038/nm1499] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 10/02/2006] [Indexed: 11/09/2022]
Abstract
The role of nitric oxide (NO) in the genesis of cerebral malaria is controversial. Most investigators propose that the unfortunate consequence of the high concentrations of NO produced to kill the parasite is the development of cerebral malaria. Here we have tested this high NO bioavailability hypothesis in the setting of experimental cerebral malaria (ECM), but find instead that low NO bioavailability contributes to the genesis of ECM. Specifically, mice deficient in vascular NO synthase showed parasitemia and mortality similar to that observed in control mice. Exogenous NO did not affect parasitemia but provided marked protection against ECM; in fact, mice treated with exogenous NO were clinically indistinguishable from uninfected mice at a stage when control infected mice were moribund. Administration of exogenous NO restored NO-mediated signaling in the brain, decreased proinflammatory biomarkers in the blood, and markedly reduced vascular leak and petechial hemorrhage into the brain. Low NO bioavailability in the vasculature during ECM was caused in part by an increase in NO-scavenging free hemoglobin in the blood, by hypoargininemia, and by low blood and erythrocyte nitrite concentrations. Exogenous NO inactivated NO-scavenging free hemoglobin in the plasma and restored nitrite to concentrations observed in uninfected mice. We therefore conclude that low rather than high NO bioavailability contributes to the genesis of ECM.
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Affiliation(s)
- Irene Gramaglia
- La Jolla Bioengineering Institute, 505 Coast Boulevard, La Jolla, California 92037, USA
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Hurd H, Grant KM, Arambage SC. Apoptosis-like death as a feature of malaria infection in mosquitoes. Parasitology 2006; 132 Suppl:S33-47. [PMID: 17018164 DOI: 10.1017/s0031182006000849] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Malaria parasites of the genusPlasmodiummake a hazardous journey through their mosquito vectors. The majority die in the process, many as a result of the action of mosquito defence mechanisms. The mosquito too is not unscathed by the encounter with these parasites. Tissue damage occurs as a result of mid-gut invasion and reproductive fitness is lost when many developing ovarian follicles are resorbed. Here we discuss some of the mechanisms that are involved in killing the parasite and in the self-defence mechanisms employed by the mosquito to repair the mid-gut epithelium and to manipulate resources altering the trade-off position that balances reproduction and survival. In all cases, cells die by apoptotic-like mechanisms. In the midgut cells, apoptosis-induction pathways are being elucidated, the molecules involved in apoptosis are being recognised andDrosophilahomologues sought. The death of ookinetes in the mosquito mid-gut lumen is associated with caspase-like activity and, although homologues of mammalian caspases are not present in the malaria genome, other cysteine proteases that are potential candidates have been discussed. In the ovary, apoptosis of patches of follicular epithelial cells is followed by resorption of the developing follicle and a subsequent loss of egg production in that follicle.
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Affiliation(s)
- H Hurd
- Centre for Applied Entomology and Parasitology, Institute for Science and Technology in Medicine, University of Keele, Staffordshire, ST5 5BG, UK. h.hurd.keele.ac.uk
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van der Heyde HC, Nolan J, Combes V, Gramaglia I, Grau GE. A unified hypothesis for the genesis of cerebral malaria: sequestration, inflammation and hemostasis leading to microcirculatory dysfunction. Trends Parasitol 2006; 22:503-8. [PMID: 16979941 DOI: 10.1016/j.pt.2006.09.002] [Citation(s) in RCA: 304] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 08/10/2006] [Accepted: 09/01/2006] [Indexed: 11/25/2022]
Abstract
A unifying hypothesis for the genesis of cerebral malaria proposes that parasite antigens (released by replication in blood, surface molecules on parasitized erythrocytes, or merozoites) activate platelets that, in turn, contribute to the activation of the inflammatory response and increased levels of endothelial cell adhesion molecules (eCAMs). Increased levels of eCAMs result in further parasitized-erythrocyte sequestration and marked local inflammation that might disrupt the brain microvasculature, which cannot be repaired by the hemostasis system because of its procoagulant state. Disruption of the brain microvasculature can result in vascular leak and/or hemorrhaging into the brain; similar processes can occur in other vascular beds, including the lung. The blockage of functional capillaries by parasitized and/or unparasitized erythrocytes with decreased deformability or rosettes is also a key interaction between hemostasis and mechanical obstruction leading to pathogenesis. The events resulting in the development of cerebral malaria complications are multi-factorial, encompassing a dynamic interaction between three processes, thereby explaining the complexity of this deadly syndrome.
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Rivero A. Nitric oxide: an antiparasitic molecule of invertebrates. Trends Parasitol 2006; 22:219-25. [PMID: 16545612 DOI: 10.1016/j.pt.2006.02.014] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 02/02/2006] [Accepted: 02/28/2006] [Indexed: 11/26/2022]
Abstract
Since Furchgott, Ignarro and Murad won the Nobel prize in 1998 for their work on the role of nitric oxide (NO) as a signaling molecule, many reports have shown the seemingly limitless range of body functions controlled by this compound. In vertebrates, the role of NO as a defense against infection caused by viruses, bacteria, and protozoan and metazoan parasites has been known for several years. New evidence, however, shows that NO is also important in defending invertebrates against parasites. This discovery is a breakthrough in the understanding of how the invertebrate immune system works, and it has implications for the emerging field of invertebrate ecological immunology.
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Affiliation(s)
- Ana Rivero
- Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain and Génetique et Evolution des Maladies Infectieuses (CNRS UMR-IRD 2724), Montpellier 34394, France.
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