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Gao Z, Santos RB, Rupert J, Van Drunen R, Yu Y, Eckel‐Mahan K, Kolonin MG. Endothelial-specific telomerase inactivation causes telomere-independent cell senescence and multi-organ dysfunction characteristic of aging. Aging Cell 2024; 23:e14138. [PMID: 38475941 PMCID: PMC11296101 DOI: 10.1111/acel.14138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/31/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
It has remained unclear how aging of endothelial cells (EC) contributes to pathophysiology of individual organs. Cell senescence results in part from inactivation of telomerase (TERT). Here, we analyzed mice with Tert knockout specifically in EC. Tert loss in EC induced transcriptional changes indicative of senescence and tissue hypoxia in EC and in other cells. We demonstrate that EC-Tert-KO mice have leaky blood vessels. The blood-brain barrier of EC-Tert-KO mice is compromised, and their cognitive function is impaired. EC-Tert-KO mice display reduced muscle endurance and decreased expression of enzymes responsible for oxidative metabolism. Our data indicate that Tert-KO EC have reduced mitochondrial content and function, which results in increased dependence on glycolysis. Consistent with this, EC-Tert-KO mice have metabolism changes indicative of increased glucose utilization. In EC-Tert-KO mice, expedited telomere attrition is observed for EC of adipose tissue (AT), while brain and skeletal muscle EC have normal telomere length but still display features of senescence. Our data indicate that the loss of Tert causes EC senescence in part through a telomere length-independent mechanism undermining mitochondrial function. We conclude that EC-Tert-KO mice is a model of expedited vascular senescence recapitulating the hallmarks aging, which can be useful for developing revitalization therapies.
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Affiliation(s)
- Zhanguo Gao
- The Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science CenterHoustonTexasUSA
| | - Rafael Bravo Santos
- The Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science CenterHoustonTexasUSA
| | - Joseph Rupert
- The Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science CenterHoustonTexasUSA
| | - Rachel Van Drunen
- The Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science CenterHoustonTexasUSA
| | - Yongmei Yu
- The Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science CenterHoustonTexasUSA
| | - Kristin Eckel‐Mahan
- The Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science CenterHoustonTexasUSA
| | - Mikhail G. Kolonin
- The Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science CenterHoustonTexasUSA
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Carpinter BA, Renhe DC, Bellei JCB, Vieira CD, Rodolphi CM, Ferreira MVR, de Freitas CS, Neto AFDS, Coelho EAF, Mietto BDS, Gomes FLR, Rocha VN, Scopel KKG. DHA-rich fish oil plays a protective role against experimental cerebral malaria by controlling inflammatory and mechanical events from infection. J Nutr Biochem 2024; 123:109492. [PMID: 37866427 DOI: 10.1016/j.jnutbio.2023.109492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 05/17/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
Every year, thousands of children, particularly those under 5 years old, die because of cerebral malaria (CM). Following conventional treatment, approximately 25% of surviving individuals have lifelong severe neurocognitive sequelae. Therefore, improved conventional therapies or effective alternative therapies that prevent the severe infection are crucial. Omega-3 (Ω-3) polyunsaturated fatty acids (PUFAs) are known to have antioxidative and anti-inflammatory effects and protect against diverse neurological disorders, including Alzheimer's and Parkinson's diseases. However, little is known regarding the effects of Ω-3 PUFAs against parasitic infections. In this study, C57BL/6 mice received supplemental treatment of a fish oil rich in the Ω-3 PUFA, docosahexaenoic acid (DHA), which was started 15 days prior to infection with Plasmodium berghei ANKA and was maintained until the end of the study. Animals treated with the highest doses of DHA, 3.0 and 6.0 g/kg body weight, had 60 and 80% chance of survival, respectively, while all nontreated mice died by the 7th day postinfection due to CM. Furthermore, the parasite load during the critical period for CM development (5th to 11th day postinfection) was controlled in treated mice. However, after this period all animals developed high levels of parasitemia until the 20th day of infection. DHA treatment also effectively reduced blood-brain barrier (BBB) damage and brain edema and completely prevented brain hemorrhage and vascular occlusion. A strong anti-inflammatory profile was observed in the brains of DHA-treated mice, as well as, an increased number of neutrophil and reduced number of CD8+ T leukocytes in the spleen. Thus, this is the first study to demonstrate that the prophylactic use of DHA-rich fish oil exerts protective effects against experimental CM, reducing the mechanical and immunological events caused by the P. berghei ANKA infection.
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Affiliation(s)
- Bárbara Albuquerque Carpinter
- Department of Parasitology, Microbiology and Immunology and Post-Graduation Program in Biological Science, Research Centre of Parasitology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Daniela Chaves Renhe
- Department of Parasitology, Microbiology and Immunology and Post-Graduation Program in Biological Science, Research Centre of Parasitology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Jéssica Correa Bezerra Bellei
- Department of Parasitology, Microbiology and Immunology and Post-Graduation Program in Biological Science, Research Centre of Parasitology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Carolina David Vieira
- Department of Parasitology, Microbiology and Immunology and Post-Graduation Program in Biological Science, Research Centre of Parasitology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Cinthia Magalhães Rodolphi
- Department of Parasitology, Microbiology and Immunology and Post-Graduation Program in Biological Science, Research Centre of Parasitology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | | | - Camila Simões de Freitas
- Post-graduation Program in Health Sciences, Infectology and Tropical Medicine, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Adolfo Firmino da Silva Neto
- Department of Biology, Research Centre of Cellular Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Eduardo Antônio Ferraz Coelho
- Post-graduation Program in Health Sciences, Infectology and Tropical Medicine, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Bruno de Siqueira Mietto
- Department of Biology, Research Centre of Cellular Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | | | - Vinicius Novaes Rocha
- Department of Veterinary Medicine, Research Centre of Pathology and Veterinary Histology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Kézia Katiani Gorza Scopel
- Department of Parasitology, Microbiology and Immunology and Post-Graduation Program in Biological Science, Research Centre of Parasitology, Federal University of Juiz de Fora, Juiz de Fora, Brazil.
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Hadjilaou A, Brandi J, Riehn M, Friese MA, Jacobs T. Pathogenetic mechanisms and treatment targets in cerebral malaria. Nat Rev Neurol 2023; 19:688-709. [PMID: 37857843 DOI: 10.1038/s41582-023-00881-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2023] [Indexed: 10/21/2023]
Abstract
Malaria, the most prevalent mosquito-borne infectious disease worldwide, has accompanied humanity for millennia and remains an important public health issue despite advances in its prevention and treatment. Most infections are asymptomatic, but a small percentage of individuals with a heavy parasite burden develop severe malaria, a group of clinical syndromes attributable to organ dysfunction. Cerebral malaria is an infrequent but life-threatening complication of severe malaria that presents as an acute cerebrovascular encephalopathy characterized by unarousable coma. Despite effective antiparasite drug treatment, 20% of patients with cerebral malaria die from this disease, and many survivors of cerebral malaria have neurocognitive impairment. Thus, an important unmet clinical need is to rapidly identify people with malaria who are at risk of developing cerebral malaria and to develop preventive, adjunctive and neuroprotective treatments for cerebral malaria. This Review describes important advances in the understanding of cerebral malaria over the past two decades and discusses how these mechanistic insights could be translated into new therapies.
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Affiliation(s)
- Alexandros Hadjilaou
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany.
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.
| | - Johannes Brandi
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany
| | - Mathias Riehn
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany
| | - Manuel A Friese
- Institut für Neuroimmunologie und Multiple Sklerose, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas Jacobs
- Protozoen Immunologie, Bernhard-Nocht-Institut für Tropenmedizin (BNITM), Hamburg, Germany
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Conroy AL, Datta D, Opoka RO, Batte A, Bangirana P, Gopinadhan A, Mellencamp KA, Akcan-Arikan A, Idro R, John CC. Cerebrospinal fluid biomarkers provide evidence for kidney-brain axis involvement in cerebral malaria pathogenesis. Front Hum Neurosci 2023; 17:1177242. [PMID: 37200952 PMCID: PMC10185839 DOI: 10.3389/fnhum.2023.1177242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/14/2023] [Indexed: 05/20/2023] Open
Abstract
Introduction Cerebral malaria is one of the most severe manifestations of malaria and is a leading cause of acquired neurodisability in African children. Recent studies suggest acute kidney injury (AKI) is a risk factor for brain injury in cerebral malaria. The present study evaluates potential mechanisms of brain injury in cerebral malaria by evaluating changes in cerebrospinal fluid measures of brain injury with respect to severe malaria complications. Specifically, we attempt to delineate mechanisms of injury focusing on blood-brain-barrier integrity and acute metabolic changes that may underlie kidney-brain crosstalk in severe malaria. Methods We evaluated 30 cerebrospinal fluid (CSF) markers of inflammation, oxidative stress, and brain injury in 168 Ugandan children aged 18 months to 12 years hospitalized with cerebral malaria. Eligible children were infected with Plasmodium falciparum and had unexplained coma. Acute kidney injury (AKI) on admission was defined using the Kidney Disease: Improving Global Outcomes criteria. We further evaluated blood-brain-barrier integrity and malaria retinopathy, and electrolyte and metabolic complications in serum. Results The mean age of children was 3.8 years (SD, 1.9) and 40.5% were female. The prevalence of AKI was 46.3% and multi-organ dysfunction was common with 76.2% of children having at least one organ system affected in addition to coma. AKI and elevated blood urea nitrogen, but not other measures of disease severity (severe coma, seizures, jaundice, acidosis), were associated with increases in CSF markers of impaired blood-brain-barrier function, neuronal injury (neuron-specific enolase, tau), excitatory neurotransmission (kynurenine), as well as altered nitric oxide bioavailability and oxidative stress (p < 0.05 after adjustment for multiple testing). Further evaluation of potential mechanisms suggested that AKI may mediate or be associated with CSF changes through blood-brain-barrier disruption (p = 0.0014), ischemic injury seen by indirect ophthalmoscopy (p < 0.05), altered osmolality (p = 0.0006) and through alterations in the amino acids transported into the brain. Conclusion In children with cerebral malaria, there is evidence of kidney-brain injury with multiple potential pathways identified. These changes were specific to the kidney and not observed in the context of other clinical complications.
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Affiliation(s)
- Andrea L. Conroy
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Dibyadyuti Datta
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Robert O. Opoka
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
- Global Health Uganda, Kampala, Uganda
- Undergraduate Medical Education, The Aga Khan University, Nairobi, Kenya
| | - Anthony Batte
- Global Health Uganda, Kampala, Uganda
- Child Health and Development Centre, Makerere University College of Health Sciences, Kampala, Uganda
| | - Paul Bangirana
- Global Health Uganda, Kampala, Uganda
- Department of Psychiatry, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Adnan Gopinadhan
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Kagan A. Mellencamp
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Ayse Akcan-Arikan
- Division of Critical Care Medicine, Department of Pediatrics, Baylor College of Medicine, Texas Children’s Hospital, Houston, TX, United States
- Division of Nephrology, Department of Pediatrics, Baylor College of Medicine, Texas Children’s Hospital, Houston, TX, United States
| | - Richard Idro
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
- Global Health Uganda, Kampala, Uganda
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Chandy C. John
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, United States
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Potential Benefits of Lycopene Consumption: Rationale for Using It as an Adjuvant Treatment for Malaria Patients and in Several Diseases. Nutrients 2022; 14:nu14245303. [PMID: 36558462 PMCID: PMC9787606 DOI: 10.3390/nu14245303] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Malaria is a disease that affects thousands of people around the world every year. Its pathogenesis is associated with the production of reactive oxygen and nitrogen species (RONS) and lower levels of micronutrients and antioxidants. Patients under drug treatment have high levels of oxidative stress biomarkers in the body tissues, which limits the use of these drugs. Therefore, several studies have suggested that RONS inhibition may represent an adjuvant therapeutic strategy in the treatment of these patients by increasing the antioxidant capacity of the host. In this sense, supplementation with antioxidant compounds such as zinc, selenium, and vitamins A, C, and E has been suggested as part of the treatment. Among dietary antioxidants, lycopene is the most powerful antioxidant among the main carotenoids. This review aimed to describe the main mechanisms inducing oxidative stress during malaria, highlighting the production of RONS as a defense mechanism against the infection induced by the ischemia-reperfusion syndrome, the metabolism of the parasite, and the metabolism of antimalarial drugs. Furthermore, the effects of lycopene on several diseases in which oxidative stress is implicated as a cause are outlined, providing information about its mechanism of action, and providing an evidence-based justification for its supplementation in malaria.
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Omar M, Abdelal HO. Nitric oxide in parasitic infections: a friend or foe? J Parasit Dis 2022; 46:1147-1163. [PMID: 36457767 PMCID: PMC9606182 DOI: 10.1007/s12639-022-01518-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/20/2022] [Indexed: 11/28/2022] Open
Abstract
The complex interaction between the host and the parasite remains a puzzling question. Control of parasitic infections requires an efficient immune response that must be balanced against destructive pathological consequences. Nitric oxide is a nitrogenous free radical which has many molecular targets and serves diverse functions. Apart from being a signaling messenger, nitric oxide is critical for controlling numerous infections. There is still controversy surrounding the exact role of nitric oxide in the immune response against different parasitic species. It proved protective against intracellular protozoa, as well as extracellular helminths. At the same time, it plays a pivotal role in stimulating detrimental pathological changes in the infected hosts. Several reports have discussed the anti-parasitic and immunoregulatory functions of nitric oxide, which could directly influence the control of the infection. Nevertheless, there is scarce literature addressing the harmful cytotoxic impacts of this mediator. Thus, this review provides insights into the most updated concepts and controversies regarding the dual nature and opposing sides of nitric oxide during the course of different parasitic infections.
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Affiliation(s)
- Marwa Omar
- Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Gameyet Almohafza St. 1, Menya Al-Kamh, City of Zagazig, 44511 Sharkia Governorate Egypt
| | - Heba O. Abdelal
- LIS: Cross-National Data Center, Maison des Sciences Humaines - 5e étage, 11- porte des Sciences, L-4366 Esch-Belval, Luxembourg
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7
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Inhaled nitric oxide improves post-cardiac arrest outcomes via guanylate cyclase-1 in bone marrow-derived cells. Nitric Oxide 2022; 125-126:47-56. [PMID: 35716999 DOI: 10.1016/j.niox.2022.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 11/24/2022]
Abstract
RATIONALE Nitric oxide (NO) exerts its biological effects primarily via activation of guanylate cyclase (GC) and production of cyclic guanosine monophosphate. Inhaled NO improves outcomes after cardiac arrest and cardiopulmonary resuscitation (CPR). However, mechanisms of the protective effects of breathing NO after cardiac arrest are incompletely understood. OBJECTIVE To elucidate the mechanisms of beneficial effects of inhaled NO on outcomes after cardiac arrest. METHODS Adult male C57BL/6J wild-type (WT) mice, GC-1 knockout mice, and chimeric WT mice with WT or GC-1 knockout bone marrow were subjected to 8 min of potassium-induced cardiac arrest to determine the role of GC-1 in bone marrow-derived cells. Mice breathed air or 40 parts per million NO for 23 h starting at 1 h after CPR. RESULTS Breathing NO after CPR prevented hypercoagulability, cerebral microvascular occlusion, an increase in circulating polymorphonuclear neutrophils and neutrophil-to-lymphocyte ratio, and right ventricular dysfunction in WT mice, but not in GC-1 knockout mice, after cardiac arrest. The lack of GC-1 in bone marrow-derived cells diminished the beneficial effects of NO breathing after CPR. CONCLUSIONS GC-dependent signaling in bone marrow-derived cells is essential for the beneficial effects of inhaled NO after cardiac arrest and CPR.
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8
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Heme oxygenase-1, carbon monoxide, and malaria – The interplay of chemistry and biology. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Niikura M, Fukutomi T, Mineo S, Mitobe J, Kobayashi F. The association between acute fatty liver disease and nitric oxide during malaria in pregnancy. Malar J 2021; 20:462. [PMID: 34906158 PMCID: PMC8670279 DOI: 10.1186/s12936-021-03999-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Liver disease is a common feature of malaria in pregnancy, but its pathogenesis remains unclear. METHODS To understand the pathogenesis of liver disease during malaria in pregnancy, comparative proteomic analysis of the liver in a mouse model of malaria in pregnancy was performed. RESULTS Decreased levels of mitochondrial and peroxisomal proteins were observed in the livers of pregnant mice infected with the lethal rodent malaria parasite Plasmodium berghei strain NK65. By contrast, increased levels of perilipin-2, amyloid A-1, and interferon (IFN)-γ signalling pathway-related proteins were observed in the livers of infected pregnant mice, suggesting that IFN-γ signalling may contribute to the development of liver disease during malaria in pregnancy. IFN-γ signalling is a potential trigger of inducible nitric oxide synthase (iNOS) expression. Liver disease associated with microvesicular fatty infiltration and elevated liver enzymes in pregnant wild-type mice infected with malaria parasites was improved by iNOS deficiency. CONCLUSIONS In this study, a causative role of iNOS in liver disease associated with microvesicular fatty infiltration during malaria in pregnancy was demonstrated. These findings provide important insight for understanding the role of iNOS-mediated metabolic responses and the pathogenesis of high-risk liver diseases in pregnancy, such as acute fatty liver.
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Affiliation(s)
- Mamoru Niikura
- Department of Infectious Diseases, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
| | - Toshiyuki Fukutomi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Shoichiro Mineo
- Department of Molecular Pathology, Tokyo Medical University, Tokyo, 160-8402, Japan
| | - Jiro Mitobe
- Department of Infectious Diseases, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Fumie Kobayashi
- Department of Environmental Science, School of Life and Environmental Science, Azabu University, Kanagawa, 252-5201, Japan
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10
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Zou Y, Tuo F, Zhang Z, Guo J, Yuan Y, Zhang H, Xu Z, Pan Z, Tang Y, Deng C, Julie N, Wu W, Guo W, Li C, Huang X, Xu Q, Song J, Wang Q. Safety and Efficacy of Adjunctive Therapy With Artesunate in the Treatment of Severe Malaria: A Systematic Review and Meta-Analysis. Front Pharmacol 2020; 11:596697. [PMID: 33343367 PMCID: PMC7748123 DOI: 10.3389/fphar.2020.596697] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/02/2020] [Indexed: 11/13/2022] Open
Abstract
Objective: The purpose of this meta-analysis of longitudinal studies is to determine the safety and efficacy of artesunate combined with other forms of adjunctive therapies for severe malaria. Methods: Following the PRISMA guidelines, we searched multiple databases with the search terms "artesunate" and "adjunctive therapy" and "severe malaria" in July 2020. If the search showed a randomized controlled trial, the study was included in this meta-analysis. The random-effects model was used to calculate the combined incidence rate and relative risk or risk difference. Results: This meta-analysis included nine longitudinal studies with 724 participants. We found that the mortality rates in the artesunate monotherapy group and the artesunate + adjuvant therapy group are similar (RD = -0.02, 95% confidence interval: -0.06-0.02). The incidence of adverse reactions in the artesunate monotherapy group and the artesunate + adjuvant therapy group was also similar. Conclusion: No significant differences in safety and efficacy were observed between the artesunate monotherapy group and the artesunate + adjuvant therapy group. Higher quality and rigorously designed randomized controlled studies are needed to validate our findings.
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Affiliation(s)
- Yuanyuan Zou
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Fei Tuo
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhiqi Zhang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jiawen Guo
- Institute of Science and Technology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yueming Yuan
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China.,Institute of Science and Technology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Hongying Zhang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhiyong Xu
- Institute of Science and Technology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ziyi Pan
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yexiao Tang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Changsheng Deng
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Nadia Julie
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wanting Wu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wenfeng Guo
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Changqing Li
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xinan Huang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qin Xu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jianping Song
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qi Wang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
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11
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Schiess N, Villabona-Rueda A, Cottier KE, Huether K, Chipeta J, Stins MF. Pathophysiology and neurologic sequelae of cerebral malaria. Malar J 2020; 19:266. [PMID: 32703204 PMCID: PMC7376930 DOI: 10.1186/s12936-020-03336-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 07/13/2020] [Indexed: 12/14/2022] Open
Abstract
Cerebral malaria (CM), results from Plasmodium falciparum infection, and has a high mortality rate. CM survivors can retain life-long post CM sequelae, including seizures and neurocognitive deficits profoundly affecting their quality of life. As the Plasmodium parasite does not enter the brain, but resides inside erythrocytes and are confined to the lumen of the brain's vasculature, the neuropathogenesis leading to these neurologic sequelae is unclear and under-investigated. Interestingly, postmortem CM pathology differs in brain regions, such as the appearance of haemorragic punctae in white versus gray matter. Various host and parasite factors contribute to the risk of CM, including exposure at a young age, parasite- and host-related genetics, parasite sequestration and the extent of host inflammatory responses. Thus far, several proposed adjunctive treatments have not been successful in the treatment of CM but are highly needed. The region-specific CM neuro-pathogenesis leading to neurologic sequelae is intriguing, but not sufficiently addressed in research. More attention to this may lead to the development of effective adjunctive treatments to address CM neurologic sequelae.
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Affiliation(s)
- Nicoline Schiess
- Department of Neurology, Johns Hopkins School of Medicine, 600 N. Wolfe St., Meyer 6-113, Baltimore, MD, 21287, USA
| | - Andres Villabona-Rueda
- Malaria Research Institute, Dept Molecular Microbiology Immunology, Johns Hopkins School of Public Health, 615 N Wolfe Street, Baltimore, MD, 21205, USA
| | - Karissa E Cottier
- Malaria Research Institute, Dept Molecular Microbiology Immunology, Johns Hopkins School of Public Health, 615 N Wolfe Street, Baltimore, MD, 21205, USA.,BioIVT, 1450 South Rolling Road, Baltimore, MD, USA
| | | | - James Chipeta
- Department of Paediatrics, University Teaching Hospital, Nationalist Road, Lusaka, Zambia
| | - Monique F Stins
- Malaria Research Institute, Dept Molecular Microbiology Immunology, Johns Hopkins School of Public Health, 615 N Wolfe Street, Baltimore, MD, 21205, USA.
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12
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Pereira DMS, Carvalho Júnior AR, Lacerda EMDCB, da Silva LCN, Marinho CRF, André E, Fernandes ES. Oxidative and nitrosative stresses in cerebral malaria: can we target them to avoid a bad prognosis? J Antimicrob Chemother 2020; 75:1363-1373. [PMID: 32105324 DOI: 10.1093/jac/dkaa032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is currently a global effort to reduce malaria morbidity and mortality. However, malaria still results in the deaths of thousands of people every year. Malaria is caused by Plasmodium spp., parasites transmitted through the bite of an infected female Anopheles mosquito. Treatment timing plays a decisive role in reducing mortality and sequelae associated with the severe forms of the disease such as cerebral malaria (CM). The available antimalarial therapy is considered effective but parasite resistance to these drugs has been observed in some countries. Antimalarial drugs act by increasing parasite lysis, especially through targeting oxidative stress pathways. Here we discuss the roles of reactive oxygen species and reactive nitrogen intermediates in CM as a result of host-parasite interactions. We also present evidence of the potential contribution of oxidative and nitrosative stress-based antimalarial drugs to disease treatment and control.
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Affiliation(s)
| | | | | | | | | | - Eunice André
- Departamento de Farmacologia, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Elizabeth Soares Fernandes
- Programa de Pós-graduação, Universidade CEUMA, São Luís, MA, Brazil.,Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, PR, Brazil.,Faculdades Pequeno Príncipe, Curitiba, PR, Brazil
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13
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Camara A, Haddad M, Reybier K, Traoré MS, Baldé MA, Royo J, Baldé AO, Batigne P, Haidara M, Baldé ES, Coste A, Baldé AM, Aubouy A. Terminalia albida treatment improves survival in experimental cerebral malaria through reactive oxygen species scavenging and anti-inflammatory properties. Malar J 2019; 18:431. [PMID: 31852507 PMCID: PMC6921526 DOI: 10.1186/s12936-019-3071-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
Background The development of Plasmodium resistance to the last effective anti-malarial drugs necessitates the urgent development of new anti-malarial therapeutic strategies. To this end, plants are an important source of new molecules. The objective of this study was to evaluate the anti-malarial effects of Terminalia albida, a plant used in Guinean traditional medicine, as well as its anti-inflammatory and antioxidant properties, which may be useful in treating cases of severe malaria. Methods In vitro antiplasmodial activity was evaluated on a chloroquine-resistant strain of Plasmodium falciparum (K-1). In vivo efficacy of the plant extract was measured in the experimental cerebral malaria model based on Plasmodium berghei (strain ANKA) infection. Mice brains were harvested on Day 7–8 post-infection, and T cells recruitment to the brain, expression levels of pro- and anti-inflammatory markers were measured by flow cytometry, RT-qPCR and ELISA. Non-malarial in vitro models of inflammation and oxidative response were used to confirm Terminalia albida effects. Constituents of Terminalia albida extract were characterized by ultra‐high performance liquid chromatography coupled with high resolution mass spectrometry. Top ranked compounds were putatively identified using plant databases and in silico fragmentation patterns. Results In vitro antiplasmodial activity of Terminalia albida was confirmed with an IC50 of 1.5 μg/mL. In vivo, Terminalia albida treatment greatly increased survival rates in P. berghei-infected mice. Treated mice were all alive until Day 12, and the survival rate was 50% on Day 20. Terminalia albida treatment also significantly decreased parasitaemia by 100% on Day 4 and 89% on Day 7 post-infection. In vivo anti-malarial activity was related to anti-inflammatory properties, as Terminalia albida treatment decreased T lymphocyte recruitment and expression of pro-inflammatory markers in brains of treated mice. These properties were confirmed in vitro in the non-malarial model. In vitro, Terminalia albida also demonstrated a remarkable dose-dependent neutralization activity of reactive oxygen species. Twelve compounds were putatively identified in Terminalia albida stem bark. Among them, several molecules already identified may be responsible for the different biological activities observed, especially tannins and triterpenoids. Conclusion The traditional use of Terminalia albida in the treatment of malaria was validated through the combination of in vitro and in vivo studies.
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Affiliation(s)
- Aissata Camara
- UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France. .,Institute for Research and Development of Medicinal and Food Plants of Guinea (IRDPMAG), Dubréka, Guinea.
| | - Mohamed Haddad
- UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France
| | - Karine Reybier
- UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France
| | - Mohamed Sahar Traoré
- Institute for Research and Development of Medicinal and Food Plants of Guinea (IRDPMAG), Dubréka, Guinea.,Department of Pharmacy, University Gamal Abdel Nasser of Conakry, Conakry, Guinea
| | - Mamadou Aliou Baldé
- Institute for Research and Development of Medicinal and Food Plants of Guinea (IRDPMAG), Dubréka, Guinea.,Department of Pharmacy, University Gamal Abdel Nasser of Conakry, Conakry, Guinea
| | - Jade Royo
- UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France
| | - Alpha Omar Baldé
- Institute for Research and Development of Medicinal and Food Plants of Guinea (IRDPMAG), Dubréka, Guinea.,Department of Pharmacy, University Gamal Abdel Nasser of Conakry, Conakry, Guinea
| | - Philippe Batigne
- UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France
| | - Mahamane Haidara
- Department of Pharmacy, University of Sciences, Technics and Technologies (USTTB) of Bamako, Bamako, Mali
| | - Elhadj Saidou Baldé
- Institute for Research and Development of Medicinal and Food Plants of Guinea (IRDPMAG), Dubréka, Guinea.,Department of Pharmacy, University Gamal Abdel Nasser of Conakry, Conakry, Guinea
| | - Agnès Coste
- UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France
| | - Aliou Mamadou Baldé
- Department of Pharmacy, University Gamal Abdel Nasser of Conakry, Conakry, Guinea
| | - Agnès Aubouy
- UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France
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14
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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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15
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Yu B, Ichinose F, Bloch DB, Zapol WM. Inhaled nitric oxide. Br J Pharmacol 2019; 176:246-255. [PMID: 30288739 PMCID: PMC6295404 DOI: 10.1111/bph.14512] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/14/2018] [Accepted: 08/22/2018] [Indexed: 12/18/2022] Open
Abstract
Nitric oxide (NO) is a gas that induces relaxation of smooth muscle cells in the vasculature. Because NO reacts with oxyhaemoglobin with high affinity, the gas is rapidly scavenged by oxyhaemoglobin in red blood cells and the vasodilating effects of inhaled NO are limited to ventilated regions in the lung. NO therefore has the unique ability to induce pulmonary vasodilatation specifically in the portions of the lung with adequate ventilation, thereby improving oxygenation of blood and decreasing intrapulmonary right to left shunting. Inhaled NO is used to treat a spectrum of cardiopulmonary conditions, including pulmonary hypertension in children and adults. However, the widespread use of inhaled NO is limited by logistical and financial barriers. We have designed, developed and tested a simple and economic NO generation device, which uses pulsed electrical discharges in air to produce therapeutic levels of NO that can be used for inhalation therapy. LINKED ARTICLES: This article is part of a themed section on Nitric Oxide 20 Years from the 1998 Nobel Prize. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.2/issuetoc.
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Affiliation(s)
- Binglan Yu
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
| | - Fumito Ichinose
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
| | - Donald B Bloch
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
- Division of Rheumatology, Allergy and Immunology, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
| | - Warren M Zapol
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
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16
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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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17
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Hoffmann A, Pfeil J, Mueller AK, Jin J, Deumelandt K, Helluy X, Wang C, Heiland S, Platten M, Chen JW, Bendszus M, Breckwoldt MO. MRI of Iron Oxide Nanoparticles and Myeloperoxidase Activity Links Inflammation to Brain Edema in Experimental Cerebral Malaria. Radiology 2018; 290:359-367. [PMID: 30615566 DOI: 10.1148/radiol.2018181051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Purpose To investigate the association of inflammation and brain edema in a cerebral malaria (CM) mouse model with a combination of bis-5-hydroxy-tryptamide-diethylenetriaminepentaacetate gadolinium, referred to as MPO-Gd, and cross-linked iron oxide nanoparticle (CLIO-NP) imaging. Materials and Methods Female wild-type (n = 23) and myeloperoxidase (MPO) knock-out (n = 5) mice were infected with the Plasmodium berghei ANKA strain from May 2016 to July 2018. Seven healthy mice served as control animals. At a Rapid Murine Coma and Behavioral Scale (RMCBS) score of less than 15, mice underwent MRI at 9.4 T and received gadodiamide, MPO-Gd, or CLIO-NPs. T1-weighted MRI was used to assess MPO activity, and T2*-weighted MRI was used to track CLIO-NPs. Immunofluorescent staining and flow cytometric analyses characterized CLIO-NPs, MPO, endothelial cells, and leukocytes. An unpaired, two-tailed Student t test was used to compare groups; Spearman correlation analysis was used to determine the relationship of imaging parameters to clinical severity. Results MPO-Gd enhancement occurred in inflammatory CM hotspots (olfactory bulb > rostral migratory stream > brainstem > cortex, P < .05 for all regions compared with control mice; mean olfactory bulb signal intensity ratio: 1.40 ± 0.07 vs 0.96 ± 0.01, P < .01). The enhancement was reduced in MPO knockout mice (mean signal intensity ratio at 60 minutes: 1.13 ± 0.04 vs 1.40 ± 0.07 in CM, P < .05). Blood-brain barrier compromise was suggested by parenchymal gadolinium enhancement, leukocyte recruitment, and endothelial activation. CLIO-NPs accumulated mainly intravascularly and at the vascular endothelium. CLIO-NPs were also found in the choroid plexus, indicating inflammation of the ventricular system. Blood-cerebrospinal fluid barrier breakdown showed correlation with brain swelling (r2: 0.55, P < .01) and RMCBS score (r2: 0.75, P < .001). Conclusion Iron oxide nanoparticle imaging showed strong inflammatory involvement of the microvasculature in a murine model of cerebral malaria. Furthermore, bis-5-hydroxy-tryptamide-diethylenetriaminepentaacetate gadolinium imaging depicted parenchymal and intraventricular inflammation. This combined molecular imaging approach links vascular inflammation to breakdown of the blood-brain barrier and blood-cerebrospinal fluid barrier that correlate with global brain edema and disease severity. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Kiessling in this issue.
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Affiliation(s)
- Angelika Hoffmann
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Johannes Pfeil
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Ann-Kristin Mueller
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Jessica Jin
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Katrin Deumelandt
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Xavier Helluy
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Cuihua Wang
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Sabine Heiland
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Michael Platten
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - John W Chen
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Martin Bendszus
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
| | - Michael O Breckwoldt
- From the Department of Neuroradiology (A.H., J.J., X.H., S.H., M.B., M.O.B.), Centre for Infectious Diseases, Parasitology Unit (J.P., A.K.M.), and Center for Childhood and Adolescent Medicine, General Pediatrics (J.P.), University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; German Centre for Infection Research (DZIF), Heidelberg, Germany (J.P., A.K.M.); DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany (K.D., M.P., M.O.B.); NeuroImaging Centre Research, Department of Neuroscience, Ruhr-University Bochum, Bochum, Germany (X.H.); Center for Systems Biology and Institute for Innovation in Imaging (C.W., J.W.C.) and Division of Neuroradiology, Department of Radiology (J.W.C.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; and Neurology Clinic, University Hospital Mannheim, Mannheim, Germany (M.P.)
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18
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Ippolito MM, Denny JE, Langelier C, Sears CL, Schmidt NW. Malaria and the Microbiome: A Systematic Review. Clin Infect Dis 2018; 67:1831-1839. [PMID: 29701835 PMCID: PMC6260159 DOI: 10.1093/cid/ciy374] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/24/2018] [Indexed: 12/16/2022] Open
Abstract
Background The microbiome influences malaria parasite fitness and transmission efficiency in mosquitoes and appears to affect malaria dynamics in mammalian hosts as well. Nascent research examining the interrelationship of malaria and the mammalian microbiome has yielded interesting insights inviting further study. Methods We conducted a systematic review of the literature examining associations between the microbiome and malaria in mammalian hosts. An electronic search algorithm was adapted to PubMed, MEDLINE, Scopus, Embase, and Web of Science, and reference lists of relevant sources were manually searched. Identified studies were screened and assessed independently by 2 authors, and results were compiled in a qualitative synthesis of the evidence. Results Ten relevant studies were identified. They demonstrate associations between certain intestinal communities and protection against Plasmodium infection and modulation of disease severity. Plasmodium infection acutely and reversibly reshapes gut microbial composition in mice. The makeup of human skin microbial communities may influence mosquito attraction and thus disease transmission. Conclusions Early research supports a relationship between malaria and the microbiome. The evidence is incomplete, but the observed associations are evocative and signal a promising avenue of inquiry. Microbiome-based studies of malaria can be readily integrated into field-based research.
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Affiliation(s)
- Matthew M Ippolito
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland
- Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Joshua E Denny
- Department of Microbiology and Immunology, University of Louisville, Kentucky
| | - Charles Langelier
- Division of Infectious Diseases, Department of Medicine, University of California, San Francisco
| | - Cynthia L Sears
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Nathan W Schmidt
- Department of Microbiology and Immunology, University of Louisville, Kentucky
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19
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Bangirana P, Conroy AL, Opoka RO, Hawkes MT, Hermann L, Miller C, Namasopo S, Liles WC, John CC, Kain KC. Inhaled nitric oxide and cognition in pediatric severe malaria: A randomized double-blind placebo controlled trial. PLoS One 2018; 13:e0191550. [PMID: 29370261 PMCID: PMC5784958 DOI: 10.1371/journal.pone.0191550] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/04/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Severe malaria is a leading cause of acquired neurodisability in Africa and is associated with reduced nitric oxide (NO) bioavailability. A neuroprotective role for inhaled NO has been reported in animal studies, and administration of inhaled NO in preterm neonates with respiratory distress syndrome is associated with a 47% reduced risk of cognitive impairment at two years of age. METHODS A randomized double-blind placebo-controlled trial of inhaled NO versus placebo as an adjunctive therapy for severe malaria was conducted in Uganda between 2011 and 2013. Children received study gas for a maximum 72 hours (inhaled NO, 80 parts per million; room air placebo). Neurocognitive testing was performed on children<5 years at 6 month follow-up. The neurocognitive outcomes assessed were overall cognition (a composite of fine motor, visual reception, receptive language, and expressive language), attention, associative memory, and the global executive composite. Main outcomes were attention, associative memory, and overall cognitive ability. RESULTS Sixty-one children receiving iNO and 59 children receiving placebo were evaluated. Forty-two children (35.0%) were impaired in at least one neurocognitive domain. By intention-to-treat analysis, there were no differences in unadjusted or unadjusted age-adjusted z-scores for overall cognition (β (95% CI): 0.26 (-0.19, 0.72), p = 0.260), attention (0.18 (-0.14, 0.51), p = 0.267), or memory (0.14 (-0.02, 0.30), p = 0.094) between groups by linear regression. Children receiving inhaled NO had a 64% reduced relative risk of fine motor impairment than children receiving placebo (relative risk, 95% CI: 0.36, 0.14-0.96) by log binomial regression following adjustment for anticonvulsant use. CONCLUSIONS Severe malaria is associated with high rates of neurocognitive impairment. Treatment with inhaled NO was associated with reduced risk of fine motor impairment. These results need to be prospectively validated in a larger study powered to assess cognitive outcomes in order to evaluate whether strategies to increase bioavailable NO are neuroprotective in children with severe malaria. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01255215.
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Affiliation(s)
- Paul Bangirana
- Department of Psychiatry, Makerere University College of Health Sciences, Kampala, Uganda
| | - Andrea L Conroy
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Robert O Opoka
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Michael T Hawkes
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada.,Division of Pediatric Infectious Diseases, University of Alberta, Edmonton, Canada
| | - Laura Hermann
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Christopher Miller
- Department of Respiratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Sophie Namasopo
- Department of Paediatrics, Jinja Regional Referral Hospital, Jinja, Uganda
| | - W Conrad Liles
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Chandy C John
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Kevin C Kain
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada.,Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Canada
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20
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Leitgeb AM, Charunwatthana P, Rueangveerayut R, Uthaisin C, Silamut K, Chotivanich K, Sila P, Moll K, Lee SJ, Lindgren M, Holmer E, Färnert A, Kiwuwa MS, Kristensen J, Herder C, Tarning J, Wahlgren M, Dondorp AM. Inhibition of merozoite invasion and transient de-sequestration by sevuparin in humans with Plasmodium falciparum malaria. PLoS One 2017; 12:e0188754. [PMID: 29244851 PMCID: PMC5731734 DOI: 10.1371/journal.pone.0188754] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 11/03/2017] [Indexed: 11/19/2022] Open
Abstract
SEVERE MALARIA Even with the best available treatment, the mortality from severe Plasmodium falciparum malaria remains high. Typical features at death are high parasite loads and obstructed micro- vasculature. Infected erythrocytes (IE) containing mature parasites bind to the host receptor heparan sulfate, which is also an important receptor for merozoite invasion. To block merozoite invasion has not previously been proposed as an adjunctive therapeutic approach but it may preclude the early expansion of an infection that else leads to exacerbated sequestration and death. SEVUPARIN IN PHASE I STUDY The drug sevuparin was developed from heparin because heparan sulfate and heparin are nearly identical, so the rationale was that sevuparin would act as a decoy receptor during malaria infection. A phase I study was performed in healthy male volunteers and sevuparin was found safe and well tolerated. SEVUPARIN IN PHASE I/II CLINICAL STUDY A phase I/II clinical study was performed in which sevuparin was administered via short intravenous infusions to malaria patients with uncomplicated malaria who were also receiving atovaquone/proguanil treatment. This was a Phase I/II, randomized, open label, active control, parallel assignment study. Sevuparin was safe and well tolerated in the malaria patients. The mean relative numbers of ring-stage IEs decreased after a single sevuparin infusion and mature parasite IEs appeared transiently in the circulation. The effects observed on numbers of merozoites and throphozoites in the circulation, were detected already one hour after the first sevuparin injection. Here we report the development of a candidate drug named sevuparin that both blocks merozoite invasion and transiently de-sequesters IE in humans with P. falciparum malaria. TRIAL REGISTRATION ClinicalTrials.gov NCT01442168.
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Affiliation(s)
| | | | | | | | - Kamolrat Silamut
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | | | - Kirsten Moll
- Department of Microbiology, Tumor- and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Sue J. Lee
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | | | - Anna Färnert
- Department of Infectious Diseases, Karolinska University Hospital and Department Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Mpungu S. Kiwuwa
- Department of Pediatrics, School of Medicine, Makerere University College of Health Sciences, and Department of Biochemistry, School of Biomedical Sciences, Makerere University College of Health Sciences, Kampala, Uganda
| | | | | | - Joel Tarning
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mats Wahlgren
- Department of Microbiology, Tumor- and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Arjen M. Dondorp
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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21
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Novel use Of Hydroxyurea in an African Region with Malaria (NOHARM): a trial for children with sickle cell anemia. Blood 2017; 130:2585-2593. [PMID: 29051184 DOI: 10.1182/blood-2017-06-788935] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 08/18/2017] [Indexed: 11/20/2022] Open
Abstract
Hydroxyurea treatment is recommended for children with sickle cell anemia (SCA) living in high-resource malaria-free regions, but its safety and efficacy in malaria-endemic sub-Saharan Africa, where the greatest sickle-cell burden exists, remain unknown. In vitro studies suggest hydroxyurea could increase malaria severity, and hydroxyurea-associated neutropenia could worsen infections. NOHARM (Novel use Of Hydroxyurea in an African Region with Malaria) was a randomized, double-blinded, placebo-controlled trial conducted in malaria-endemic Uganda, comparing hydroxyurea to placebo at 20 ± 2.5 mg/kg per day for 12 months. The primary outcome was incidence of clinical malaria. Secondary outcomes included SCA-related adverse events (AEs), clinical and laboratory effects, and hematological toxicities. Children received either hydroxyurea (N = 104) or placebo (N = 103). Malaria incidence did not differ between children on hydroxyurea (0.05 episodes per child per year; 95% confidence interval [0.02, 0.13]) vs placebo (0.07 episodes per child per year [0.03, 0.16]); the hydroxyurea/placebo malaria incidence rate ratio was 0.7 ([0.2, 2.7]; P = .61). Time to infection also did not differ significantly between treatment arms. A composite SCA-related clinical outcome (vaso-occlusive painful crisis, dactylitis, acute chest syndrome, splenic sequestration, or blood transfusion) was less frequent with hydroxyurea (45%) than placebo (69%; P = .001). Children receiving hydroxyurea had significantly increased hemoglobin concentration and fetal hemoglobin, with decreased leukocytes and reticulocytes. Serious AEs, sepsis episodes, and dose-limiting toxicities were similar between treatment arms. Three deaths occurred (2 hydroxyurea, 1 placebo, and none from malaria). Hydroxyurea treatment appears safe for children with SCA living in malaria-endemic sub-Saharan Africa, without increased severe malaria, infections, or AEs. Hydroxyurea provides SCA-related laboratory and clinical efficacy, but optimal dosing and monitoring regimens for Africa remain undefined. This trial was registered at www.clinicaltrials.gov as #NCT01976416.
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22
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S-Nitrosoglutathione Reductase Deficiency Confers Improved Survival and Neurological Outcome in Experimental Cerebral Malaria. Infect Immun 2017; 85:IAI.00371-17. [PMID: 28674030 DOI: 10.1128/iai.00371-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/26/2017] [Indexed: 11/20/2022] Open
Abstract
Artesunate remains the mainstay of treatment for cerebral malaria, but it is less effective in later stages of disease when the host inflammatory response and blood-brain barrier integrity dictate clinical outcomes. Nitric oxide (NO) is an important regulator of inflammation and microvascular integrity, and impaired NO bioactivity is associated with fatal outcomes in malaria. Endogenous NO bioactivity in mammals is largely mediated by S-nitrosothiols (SNOs). Based on these observations, we hypothesized that animals deficient in the SNO-metabolizing enzyme, S-nitrosoglutathione reductase (GSNOR), which exhibit enhanced S-nitrosylation, would have improved outcomes in a preclinical model of cerebral malaria. GSNOR knockout (KO) mice infected with Plasmodium berghei ANKA had significantly delayed mortality compared to WT animals (P < 0.0001), despite higher parasite burdens (P < 0.01), and displayed markedly enhanced survival versus the wild type (WT) when treated with the antimalarial drug artesunate (77% versus 38%; P < 0.001). Improved survival was associated with higher levels of protein-bound NO, decreased levels of CD4+ and CD8+ T cells in the brain, improved blood-brain barrier integrity, and improved coma scores, as well as higher levels of gamma interferon. GSNOR KO animals receiving WT bone marrow had significantly reduced survival following P. berghei ANKA infection compared to those receiving KO bone barrow (P < 0.001). Reciprocal transplants established that survival benefits of GSNOR deletion were attributable primarily to the T cell compartment. These data indicate a role for GSNOR in the host response to malaria infection and suggest that strategies to disrupt its activity will improve clinical outcomes by enhancing microvascular integrity and modulating T cell tissue tropism.
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23
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Alkaitis MS, Wang H, Ikeda AK, Rowley CA, MacCormick IJC, Chertow JH, Billker O, Suffredini AF, Roberts DJ, Taylor TE, Seydel KB, Ackerman HC. Decreased Rate of Plasma Arginine Appearance in Murine Malaria May Explain Hypoargininemia in Children With Cerebral Malaria. J Infect Dis 2017; 214:1840-1849. [PMID: 27923948 DOI: 10.1093/infdis/jiw452] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/16/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Plasmodium infection depletes arginine, the substrate for nitric oxide synthesis, and impairs endothelium-dependent vasodilation. Increased conversion of arginine to ornithine by parasites or host arginase is a proposed mechanism of arginine depletion. METHODS We used high-performance liquid chromatography to measure plasma arginine, ornithine, and citrulline levels in Malawian children with cerebral malaria and in mice infected with Plasmodium berghei ANKA with or without the arginase gene. Heavy isotope-labeled tracers measured by quadrupole time-of-flight liquid chromatography-mass spectrometry were used to quantify the in vivo rate of appearance and interconversion of plasma arginine, ornithine, and citrulline in infected mice. RESULTS Children with cerebral malaria and P. berghei-infected mice demonstrated depletion of plasma arginine, ornithine, and citrulline. Knock out of Plasmodium arginase did not alter arginine depletion in infected mice. Metabolic tracer analysis demonstrated that plasma arginase flux was unchanged by P. berghei infection. Instead, infected mice exhibited decreased rates of plasma arginine, ornithine, and citrulline appearance and decreased conversion of plasma citrulline to arginine. Notably, plasma arginine use by nitric oxide synthase was decreased in infected mice. CONCLUSIONS Simultaneous arginine and ornithine depletion in malaria parasite-infected children cannot be fully explained by plasma arginase activity. Our mouse model studies suggest that plasma arginine depletion is driven primarily by a decreased rate of appearance.
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Affiliation(s)
- Matthew S Alkaitis
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville.,Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Headington
| | - Honghui Wang
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Allison K Ikeda
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville
| | - Carol A Rowley
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville
| | - Ian J C MacCormick
- Department of Eye and Vision Science, University of Liverpool.,Centre for Clinical Brain Sciences, University of Edinburgh.,Malawi-Liverpool-Wellcome Trust Clinical Research Programme
| | - Jessica H Chertow
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville
| | | | - Anthony F Suffredini
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - David J Roberts
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Headington.,National Health Service Blood and Transplant, John Radcliffe Hospital, Oxford, United Kingdom
| | - Terrie E Taylor
- Michigan State University, East Lansing.,Blantyre Malaria Project, Malawi
| | - Karl B Seydel
- Michigan State University, East Lansing.,Blantyre Malaria Project, Malawi
| | - Hans C Ackerman
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville
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24
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Kato GJ, Steinberg MH, Gladwin MT. Intravascular hemolysis and the pathophysiology of sickle cell disease. J Clin Invest 2017; 127:750-760. [PMID: 28248201 DOI: 10.1172/jci89741] [Citation(s) in RCA: 410] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hemolysis is a fundamental feature of sickle cell anemia that contributes to its pathophysiology and phenotypic variability. Decompartmentalized hemoglobin, arginase 1, asymmetric dimethylarginine, and adenine nucleotides are all products of hemolysis that promote vasomotor dysfunction, proliferative vasculopathy, and a multitude of clinical complications of pulmonary and systemic vasculopathy, including pulmonary hypertension, leg ulcers, priapism, chronic kidney disease, and large-artery ischemic stroke. Nitric oxide (NO) is inactivated by cell-free hemoglobin in a dioxygenation reaction that also oxidizes hemoglobin to methemoglobin, a non-oxygen-binding form of hemoglobin that readily loses heme. Circulating hemoglobin and heme represent erythrocytic danger-associated molecular pattern (eDAMP) molecules, which activate the innate immune system and endothelium to an inflammatory, proadhesive state that promotes sickle vaso-occlusion and acute lung injury in murine models of sickle cell disease. Intravascular hemolysis can impair NO bioavailability and cause oxidative stress, altering redox balance and amplifying physiological processes that govern blood flow, hemostasis, inflammation, and angiogenesis. These pathological responses promote regional vasoconstriction and subsequent blood vessel remodeling. Thus, intravascular hemolysis represents an intrinsic mechanism for human vascular disease that manifests clinical complications in sickle cell disease and other chronic hereditary or acquired hemolytic anemias.
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25
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Barker KR, Lu Z, Kim H, Zheng Y, Chen J, Conroy AL, Hawkes M, Cheng HS, Njock MS, Fish JE, Harlan JM, López JA, Liles WC, Kain KC. miR-155 Modifies Inflammation, Endothelial Activation and Blood-Brain Barrier Dysfunction in Cerebral Malaria. Mol Med 2017; 23:24-33. [PMID: 28182191 DOI: 10.2119/molmed.2016.00139] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 01/26/2017] [Indexed: 12/17/2022] Open
Abstract
miR-155 has been shown to participate in host response to infection and neuro-inflammation via negative regulation of blood-brain-barrier (BBB) integrity and T cell function. We hypothesized that miR-155 may contribute to the pathogenesis of cerebral malaria (CM). To test this hypothesis, we used a genetic approach to modulate miR-155 expression in an experimental model of cerebral malaria (ECM). In addition, an engineered endothelialized microvessel system and serum samples from Ugandan children with CM were used to examine an anti-miR-155 as a potential adjunctive therapeutic for severe malaria. Despite higher parasitemia, survival was significantly improved in miR-155-/- mice vs. wild-type littermate mice in ECM. Improved survival was associated with preservation of BBB integrity and reduced endothelial activation, despite increased levels of pro-inflammatory cytokines. Pre-treatment with antagomir-155 reduced vascular leak induced by human CM sera in an ex vivo endothelial microvessel model. These data provide evidence supporting a mechanistic role for miR-155 in host response to malaria via regulation of endothelial activation, microvascular leak and BBB dysfunction in CM.
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Affiliation(s)
- Kevin Richard Barker
- Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada.,Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, and the Tropical Disease Unit, Department of Medicine, University of Toronto, ON, Canada
| | - Ziyue Lu
- Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, and the Tropical Disease Unit, Department of Medicine, University of Toronto, ON, Canada
| | - Hani Kim
- Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, and the Tropical Disease Unit, Department of Medicine, University of Toronto, ON, Canada
| | - Ying Zheng
- Department of Bioengineering, University of Washington, Seattle, WA, USA; Center of Cardiovascular Biology, Institute of Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
| | - Junmei Chen
- Bloodworks Northwest Research Institute, Seattle, WA, USA
| | - Andrea L Conroy
- Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, and the Tropical Disease Unit, Department of Medicine, University of Toronto, ON, Canada
| | - Michael Hawkes
- Division of Infectious Diseases, Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Henry S Cheng
- Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada.,Toronto General Research Institute, University Health Network, Toronto, ON, Canada; Heart and Stroke Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON, Canada
| | - Makon-Sébastien Njock
- Toronto General Research Institute, University Health Network, Toronto, ON, Canada; Heart and Stroke Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON, Canada
| | - Jason E Fish
- Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada.,Toronto General Research Institute, University Health Network, Toronto, ON, Canada; Heart and Stroke Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON, Canada
| | - John M Harlan
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - Jose A López
- Bloodworks Northwest Research Institute, Seattle, WA, USA.,Department of Medicine, University of Washington, Seattle, WA, USA
| | - W Conrad Liles
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - Kevin C Kain
- Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada.,Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, and the Tropical Disease Unit, Department of Medicine, University of Toronto, ON, Canada
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26
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de Jong GM, Slager JJ, Verbon A, van Hellemond JJ, van Genderen PJJ. Systematic review of the role of angiopoietin-1 and angiopoietin-2 in Plasmodium species infections: biomarkers or therapeutic targets? Malar J 2016; 15:581. [PMID: 27905921 PMCID: PMC5134107 DOI: 10.1186/s12936-016-1624-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/19/2016] [Indexed: 03/01/2023] Open
Abstract
BACKGROUND Levels of both angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) correlate with malaria disease severity and are proposed as biomarkers and possible therapeutic targets. To establish their role in malaria, a systematic review was performed of the literature on Ang-1 and Ang-2 with regard to their potential as biomarkers in malaria and discuss their possible place in adjuvant treatment regimens. METHODS Ten electronic databases were systematically searched to identify studies investigating Ang-1 and Ang-2 in human and murine malaria in both clinical and experimental settings. Information about the predictive value of Ang-1 and Ang-2 for disease severity and their regulatory changes in interventional studies were extracted. RESULTS Some 579 studies were screened; 26 were included for analysis. In all five studies that determined Ang-1 levels and in all 11 studies that determined Ang-2 in different disease severity states in falciparum malaria, a decline in Ang-1 and an increase of Ang-2 levels was associated with increasing disease severity. All nine studies that determined angiopoietin levels in Plasmodium falciparum patients to study their ability as biomarkers could distinguish between multiple disease severity states; the more the disease severity states differed, the better they could be distinguished. Five studies differentiating malaria survivors from non-survivors with Ang-2 as marker found an AUROC in a range of 0.71-0.83, which performed as well or better than lactate. Prophylactic administration of FTY720, rosiglitazone or inhalation of nitric oxide (NO) during malaria disease in mice resulted in an increase in Ang-1, a decrease in Ang-2 and an increased survival. For rosiglitazone, a decrease in Ang-2/Ang-1 ratio was observed after post-infection treatment in mice and humans with malaria, but for inhalation of NO, an effect on Ang-1 and survival was only observed in mice. CONCLUSION Both Ang-1 and Ang-2 levels correlate with and can distinguish between malaria disease severity states within the group of malaria-infected patients. However, distinct comparisons of disease severity states were made in distinct studies and not all distinctions made had clinical relevance. Changes in levels of Ang-1 and Ang-2 might also reflect treatment effectiveness and are promising therapeutic targets as part of multi-targeted therapy.
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Affiliation(s)
- Gerdie M. de Jong
- Institute for Tropical Diseases, Harbour Hospital, Haringvliet 2, Rotterdam, The Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Jasper J. Slager
- Institute for Tropical Diseases, Harbour Hospital, Haringvliet 2, Rotterdam, The Netherlands
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Annelies Verbon
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - Jaap J. van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
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Conroy AL, Hawkes M, Hayford K, Hermann L, McDonald CR, Sharma S, Namasopo S, Opoka RO, John CC, Liles WC, Miller C, Kain KC. Methemoglobin and nitric oxide therapy in Ugandan children hospitalized for febrile illness: results from a prospective cohort study and randomized double-blind placebo-controlled trial. BMC Pediatr 2016; 16:177. [PMID: 27814710 PMCID: PMC5097382 DOI: 10.1186/s12887-016-0719-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 10/25/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Exposure of red blood cells to oxidants increases production of methemoglobin (MHb) resulting in impaired oxygen delivery to tissues. There are no reliable estimates of methemoglobinemia in low resource clinical settings. Our objectives were to: i) evaluate risk factors for methemoglobinemia in Ugandan children hospitalized with fever (study 1); and ii) investigate MHb responses in critically ill Ugandan children with severe malaria treated with inhaled nitric oxide (iNO), an oxidant that induces MHb in a dose-dependent manner (study 2). METHODS Two prospective studies were conducted at Jinja Regional Referral Hospital in Uganda between 2011 and 2013. Study 1, a prospective cohort study of children admitted to hospital with fever (fever cohort, n = 2089 children 2 months to 5 years). Study 2, a randomized double-blind placebo-controlled parallel arm trial of room air placebo vs. 80 ppm iNO as an adjunctive therapy for children with severe malaria (RCT, n = 180 children 1-10 years receiving intravenous artesunate and 72 h of study gas). The primary outcomes were: i) masimo pulse co-oximetry elevated MHb levels at admission (>2 %, fever cohort); ii) four hourly MHb levels in the RCT. RESULTS In the fever cohort, 34 % of children admitted with fever had elevated MHb at admission. Children with a history of vomiting, delayed capillary refill, elevated lactate, severe anemia, malaria, or hemoglobinopathies had increased odds of methemoglobinemia (p < 0.05 in a multivariate model). MHb levels at admission were higher in children who died (n = 89) compared to those who survived (n = 1964), p = 0.008. Among children enrolled in the iNO RCT, MHb levels typically plateaued within 12-24 h of starting study gas. MHb levels were higher in children receiving iNO compared to placebo, and MHb > 10 % occurred in 5.7 % of children receiving iNO. There were no differences in rates of study gas discontinuation between trial arms. CONCLUSIONS Hospitalized children with evidence of impaired oxygen delivery, metabolic acidosis, anemia, or malaria were at risk of methemoglobinemia. However, we demonstrated high-dose iNO could be safely administered to critically ill children with severe malaria with appropriate MHb monitoring. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01255215 (Date registered: December 5, 2010).
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Affiliation(s)
- Andrea L Conroy
- Depatment of Medicine, University of Toronto, Toronto, Canada.,Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Michael Hawkes
- Division of Pediatric Infectious Diseases, University of Alberta, Edmonton, Canada
| | - Kyla Hayford
- Depatment of Medicine, University of Toronto, Toronto, Canada.,Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Laura Hermann
- Depatment of Medicine, University of Toronto, Toronto, Canada
| | - Chloe R McDonald
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, Canada
| | - Suparna Sharma
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Sophie Namasopo
- Department of Pediatrics, Jinja Regional Referral Hospital, Jinja, Uganda
| | - Robert O Opoka
- Department of Paediatrics and Child Health, Mulago Hospital, Makerere University, Kampala, Uganda
| | - Chandy C John
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - W Conrad Liles
- Department of Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Christopher Miller
- Department of Respiratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Kevin C Kain
- Depatment of Medicine, University of Toronto, Toronto, Canada. .,Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada. .,Institute of Medical Sciences, University of Toronto, Toronto, Canada. .,Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Canada. .,MaRS Centre, TMDT, 10th floor 10-351, Toronto, ON, M5G1L7, Canada.
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Severe malaria: what's new on the pathogenesis front? Int J Parasitol 2016; 47:145-152. [PMID: 27670365 DOI: 10.1016/j.ijpara.2016.08.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/09/2016] [Accepted: 08/15/2016] [Indexed: 12/25/2022]
Abstract
Plasmodium falciparum causes the most severe and fatal form of malaria in humans with over half a million deaths each year. Cerebral malaria, a complex neurological syndrome of severe falciparum malaria, is often fatal and represents a major public health burden. Despite vigorous efforts, the pathophysiology of cerebral malaria remains to be elucidated, thereby hindering the development of adjunctive therapies. In recent years, multidisciplinary and collaborative approaches have led to groundbreaking progress both in the laboratory and in the field. Here we review the latest breakthroughs in severe malaria pathogenesis, with a specific focus on new pathogenetic mechanisms leading to cerebral malaria. The most recent findings point towards specific parasite phenotypes targeting brain microvasculature, endothelial dysfunction and subsequent oedema-induced brain swelling.
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CD47-SIRPα Interactions Regulate Macrophage Uptake of Plasmodium falciparum-Infected Erythrocytes and Clearance of Malaria In Vivo. Infect Immun 2016; 84:2002-2011. [PMID: 27091932 DOI: 10.1128/iai.01426-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/15/2016] [Indexed: 01/02/2023] Open
Abstract
CD47 engagement by the macrophage signal regulatory protein alpha (SIRPα) inhibits phagocytic activity and protects red blood cells (RBCs) from erythrophagocytosis. The role of CD47-SIRPα in the innate immune response to Plasmodium falciparum infection is unknown. We hypothesized that disruption of SIRPα signaling may enhance macrophage uptake of malaria parasite-infected RBCs. To test this hypothesis, we examined in vivo clearance in CD47-deficient mice infected with Plasmodium berghei ANKA and in vitro phagocytosis of P. falciparum-infected RBCs by macrophages from SHP-1-deficient (Shp-1(-/-)) mice and NOD.NOR-Idd13.Prkdc(scid) (NS-Idd13) mice, as well as human macrophages, following disruption of CD47-SIRPα interactions with anti-SIRPα antibodies or recombinant SIRPα-Fc fusion protein. Compared to their wild-type counterparts, Cd47(-/-) mice displayed significantly lower parasitemia, decreased endothelial activation, and enhanced survival. Using macrophages from SHP-1-deficient mice or from NS-Idd13 mice, which express a SIRPα variant that does not bind human CD47, we showed that altered SIRPα signaling resulted in enhanced phagocytosis of P. falciparum-infected RBCs. Moreover, disrupting CD47-SIRPα engagement using anti-SIRPα antibodies or SIRPα-Fc fusion protein also increased phagocytosis of P. falciparum-infected RBCs. These results indicate an important role for CD47-SIRPα interactions in innate control of malaria and suggest novel targets for intervention.
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Anyanwu JN, Williams O, Sautter CL, Kasirye P, Hume H, Opoka RO, Latham T, Ndugwa C, Ware RE, John CC. Novel Use of Hydroxyurea in an African Region With Malaria: Protocol for a Randomized Controlled Clinical Trial. JMIR Res Protoc 2016; 5:e110. [PMID: 27339303 PMCID: PMC4937184 DOI: 10.2196/resprot.5599] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/03/2016] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Sickle cell anemia (SCA), one of most prevalent monogenic diseases worldwide, is caused by a glutamic acid to valine substitution on the beta globin protein of hemoglobin, which leads to hemolytic anemia. Hydroxyurea, the only disease-modifying therapy approved by the Food and Drug Administration for SCA, has proven to be a viable therapeutic option for SCA patients in resource-rich settings, given clinical improvements experienced while taking the medication and its once-daily oral dosing. Significant studies have demonstrated its safety and clinical efficacy among children and adults in developed countries. In Sub-Saharan Africa, however, the risk of malaria, hematologic toxicities, and safety of hydroxyurea in children with SCA living in malaria-endemic areas are unknown. OBJECTIVES Study objectives include determining the incidence of malaria in SCA patients taking hydroxyurea versus placebo; establishing the frequency of hematologic toxicities and adverse events (AEs) in children with SCA treated with hydroxyurea versus placebo; and defining the relationships between hydroxyurea treatment and fetal hemoglobin, soluble intracellular adhesion molecule-1, and nitric oxide levels, and between levels of these factors and risk of subsequent malaria. METHODS Novel use Of Hydroxyurea in an African Region with Malaria (NOHARM, NCT01976416) is a prospective, randomized, placebo-controlled, double-blinded phase III trial to compare risk of malaria with oral hydroxyurea versus placebo. Children will be recruited from the Mulago Hospital Sickle Cell Clinic in Kampala, Uganda. RESULTS Two hundred Ugandan children aged between 1.00 and 3.99 years with confirmed SCA will be randomized into treatment groups by order of entry in the study, based on a predetermined blinded randomization list. The primary outcome of the trial is malaria incidence in the 2 study groups, defined as episodes of clinical malaria occurring over the 1-year randomized study treatment period. CONCLUSION NOHARM will be the first prospective randomized, placebo-controlled clinical trial investigating the use of hydroxyurea for children with SCA in a malaria-endemic region within Africa. The results of this trial have the potential to significantly advance understanding of how to safely and effectively use hydroxyurea in children with SCA in malaria-endemic areas. TRIAL REGISTRATION Clinicaltrials.gov NCT01976416; https://clinicaltrials.gov/ct2/show/NCT01976416 (Archived by WebCite at http://www.webcitation.org/6hmoilZnp).
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Kayano ACAV, Dos-Santos JCK, Bastos MF, Carvalho LJ, Aliberti J, Costa FTM. Pathophysiological Mechanisms in Gaseous Therapies for Severe Malaria. Infect Immun 2016; 84:874-882. [PMID: 26831465 PMCID: PMC4807480 DOI: 10.1128/iai.01404-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Over 200 million people worldwide suffer from malaria every year, a disease that causes 584,000 deaths annually. In recent years, significant improvements have been achieved on the treatment of severe malaria, with intravenous artesunate proving superior to quinine. However, mortality remains high, at 8% in children and 15% in adults in clinical trials, and even worse in the case of cerebral malaria (18% and 30%, respectively). Moreover, some individuals who do not succumb to severe malaria present long-term cognitive deficits. These observations indicate that strategies focused only on parasite killing fail to prevent neurological complications and deaths associated with severe malaria, possibly because clinical complications are associated in part with a cerebrovascular dysfunction. Consequently, different adjunctive therapies aimed at modulating malaria pathophysiological processes are currently being tested. However, none of these therapies has shown unequivocal evidence in improving patient clinical status. Recently, key studies have shown that gaseous therapies based mainly on nitric oxide (NO), carbon monoxide (CO), and hyperbaric (pressurized) oxygen (HBO) alter vascular endothelium dysfunction and modulate the host immune response to infection. Considering gaseous administration as a promising adjunctive treatment against severe malaria cases, we review here the pathophysiological mechanisms and the immunological aspects of such therapies.
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Affiliation(s)
- Ana Carolina A V Kayano
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - João Conrado K Dos-Santos
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Marcele F Bastos
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Leonardo J Carvalho
- Laboratory of Malaria Research, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil
| | - Júlio Aliberti
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Fabio T M Costa
- Laboratory of Tropical Diseases-Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, Institute of Biology, University of Campinas, Campinas, SP, Brazil
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McDonald CR, Tran V, Kain KC. Complement Activation in Placental Malaria. Front Microbiol 2015; 6:1460. [PMID: 26733992 PMCID: PMC4685051 DOI: 10.3389/fmicb.2015.01460] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 12/07/2015] [Indexed: 01/06/2023] Open
Abstract
Sixty percent of all pregnancies worldwide occur in malaria endemic regions. Pregnant women are at greater risk of malaria infection than their non-pregnant counterparts and have a higher risk of adverse birth outcomes including low birth weight resulting from intrauterine growth restriction and/or preterm birth. The complement system plays an essential role in placental and fetal development as well as the host innate immune response to malaria infection. Excessive or dysregulated complement activation has been associated with the pathobiology of severe malaria and with poor pregnancy outcomes, dependent and independent of infection. Here we review the role of complement in malaria and pregnancy and discuss its part in mediating altered placental angiogenesis, malaria-induced adverse birth outcomes, and disruptions to the in utero environment with possible consequences on fetal neurodevelopment. A detailed understanding of the mechanisms underlying adverse birth outcomes, and the impact of maternal malaria infection on fetal neurodevelopment, may lead to biomarkers to identify at-risk pregnancies and novel therapeutic interventions to prevent these complications.
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Affiliation(s)
- Chloe R McDonald
- Sandra Rotman Laboratories, Sandra Rotman Centre for Global Health, Toronto General Research Institute, University Health Network, TorontoON, Canada; Department of Global Health and Population, Harvard School of Public Health, BostonMA, USA
| | - Vanessa Tran
- Sandra Rotman Laboratories, Sandra Rotman Centre for Global Health, Toronto General Research Institute, University Health Network, Toronto ON, Canada
| | - Kevin C Kain
- Sandra Rotman Laboratories, Sandra Rotman Centre for Global Health, Toronto General Research Institute, University Health Network, TorontoON, Canada; Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, TorontoON, Canada
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Deroost K, Pham TT, Opdenakker G, Van den Steen PE. The immunological balance between host and parasite in malaria. FEMS Microbiol Rev 2015; 40:208-57. [PMID: 26657789 DOI: 10.1093/femsre/fuv046] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2015] [Indexed: 12/16/2022] Open
Abstract
Coevolution of humans and malaria parasites has generated an intricate balance between the immune system of the host and virulence factors of the parasite, equilibrating maximal parasite transmission with limited host damage. Focusing on the blood stage of the disease, we discuss how the balance between anti-parasite immunity versus immunomodulatory and evasion mechanisms of the parasite may result in parasite clearance or chronic infection without major symptoms, whereas imbalances characterized by excessive parasite growth, exaggerated immune reactions or a combination of both cause severe pathology and death, which is detrimental for both parasite and host. A thorough understanding of the immunological balance of malaria and its relation to other physiological balances in the body is of crucial importance for developing effective interventions to reduce malaria-related morbidity and to diminish fatal outcomes due to severe complications. Therefore, we discuss in this review the detailed mechanisms of anti-malarial immunity, parasite virulence factors including immune evasion mechanisms and pathogenesis. Furthermore, we propose a comprehensive classification of malaria complications according to the different types of imbalances.
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Affiliation(s)
- Katrien Deroost
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium The Francis Crick Institute, Mill Hill Laboratory, London, NW71AA, UK
| | - Thao-Thy Pham
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Ghislain Opdenakker
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Philippe E Van den Steen
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
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Hawkes MT, Conroy AL, Opoka RO, Hermann L, Thorpe KE, McDonald C, Kim H, Higgins S, Namasopo S, John C, Miller C, Liles WC, Kain KC. Inhaled nitric oxide as adjunctive therapy for severe malaria: a randomized controlled trial. Malar J 2015; 14:421. [PMID: 26510464 PMCID: PMC4625637 DOI: 10.1186/s12936-015-0946-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/21/2015] [Indexed: 05/15/2023] Open
Abstract
BACKGROUND Severe malaria remains a major cause of childhood mortality globally. Decreased endothelial nitric oxide is associated with severe and fatal malaria. The hypothesis was that adjunctive inhaled nitric oxide (iNO) would improve outcomes in African children with severe malaria. METHODS A randomized, blinded, placebo-controlled trial of iNO at 80 ppm by non-rebreather mask versus room air placebo as adjunctive treatment to artesunate in children with severe malaria was conducted. The primary outcome was the longitudinal course of angiopoietin-2 (Ang-2), an endothelial biomarker of malaria severity and clinical outcome. RESULTS One hundred and eighty children were enrolled; 88 were assigned to iNO and 92 to placebo (all received IV artesunate). Ang-2 levels measured over the first 72 h of hospitalization were not significantly different between groups. The mortality at 48 h was similar between groups [6/87 (6.9 %) in the iNO group vs 8/92 (8.7 %) in the placebo group; OR 0.78, 95 % CI 0.26-2.3; p = 0.65]. Clinical recovery times and parasite clearance kinetics were similar (p > 0.05). Methaemoglobinaemia >7 % occurred in 25 % of patients receiving iNO and resolved without sequelae. The incidence of neurologic deficits (<14 days), acute kidney injury, hypoglycaemia, anaemia, and haemoglobinuria was similar between groups (p > 0.05). CONCLUSIONS iNO at 80 ppm administered by non-rebreather mask was safe but did not affect circulating levels of Ang-2. Alternative methods of enhancing endothelial NO bioavailability may be necessary to achieve a biological effect and improve clinical outcome. TRIAL REGISTRATION ClinicalTrials.gov NCT01255215.
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Affiliation(s)
- Michael T Hawkes
- 3-588D Edmonton Clinic Health Academy, University of Alberta, 11405 87 Ave NW, Edmonton, AB, T6G 1C9, Canada.
| | - Andrea L Conroy
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Robert O Opoka
- Global Health Uganda, Upper Paediatrics Office, Mulago Hospital, PO Box 33842, Plot 138, Upper Mawanda Road, Kawempe, Kampala, Uganda.
| | - Laura Hermann
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Kevin E Thorpe
- Applied Health Research Centre, St Michael's Hospital, 250 Yonge St, 6th Floor, Toronto, ON, M5T 3M7, Canada.
| | - Chloe McDonald
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Hani Kim
- Johns Hopkins School of Public Health, International Vaccine Access Center, 615 N Wolfe St, Baltimore, MD, 21205, USA.
| | - Sarah Higgins
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Sophie Namasopo
- Jinja Regional Referral Hospital, Plot 7, Nalufenya Road, Jinja, Uganda.
| | - Chandy John
- Department of Pediatrics, Indiana University, 702 Barnhill Dr, Room 5900, Indianapolis, IN, 46202, USA.
| | - Chris Miller
- Division of Infectious Disease, University of British Columbia, Rm D433, HP East, Vancouver Hospital, 2733 Heather Street, Vancouver, BC, V5Z-3J5, Canada.
| | - W Conrad Liles
- Department of Medicine, University of Washington, 1959 NE Pacific Street, HSB RR-511, Box 356420, Seattle, WA, 98195-6420, USA.
| | - Kevin C Kain
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
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Chertow JH, Alkaitis MS, Nardone G, Ikeda AK, Cunnington AJ, Okebe J, Ebonyi AO, Njie M, Correa S, Jayasooriya S, Casals-Pascual C, Billker O, Conway DJ, Walther M, Ackerman H. Plasmodium Infection Is Associated with Impaired Hepatic Dimethylarginine Dimethylaminohydrolase Activity and Disruption of Nitric Oxide Synthase Inhibitor/Substrate Homeostasis. PLoS Pathog 2015; 11:e1005119. [PMID: 26407009 PMCID: PMC4583463 DOI: 10.1371/journal.ppat.1005119] [Citation(s) in RCA: 18] [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: 12/16/2014] [Accepted: 07/29/2015] [Indexed: 12/04/2022] Open
Abstract
Inhibition of nitric oxide (NO) signaling may contribute to pathological activation of the vascular endothelium during severe malaria infection. Dimethylarginine dimethylaminohydrolase (DDAH) regulates endothelial NO synthesis by maintaining homeostasis between asymmetric dimethylarginine (ADMA), an endogenous NO synthase (NOS) inhibitor, and arginine, the NOS substrate. We carried out a community-based case-control study of Gambian children to determine whether ADMA and arginine homeostasis is disrupted during severe or uncomplicated malaria infections. Circulating plasma levels of ADMA and arginine were determined at initial presentation and 28 days later. Plasma ADMA/arginine ratios were elevated in children with acute severe malaria compared to 28-day follow-up values and compared to children with uncomplicated malaria or healthy children (p<0.0001 for each comparison). To test the hypothesis that DDAH1 is inactivated during Plasmodium infection, we examined DDAH1 in a mouse model of severe malaria. Plasmodium berghei ANKA infection inactivated hepatic DDAH1 via a post-transcriptional mechanism as evidenced by stable mRNA transcript number, decreased DDAH1 protein concentration, decreased enzyme activity, elevated tissue ADMA, elevated ADMA/arginine ratio in plasma, and decreased whole blood nitrite concentration. Loss of hepatic DDAH1 activity and disruption of ADMA/arginine homeostasis may contribute to severe malaria pathogenesis by inhibiting NO synthesis. During a malaria infection, the vascular endothelium becomes more adhesive, permeable, and prone to trigger blood clotting. These changes help the parasite adhere to blood vessels, but endanger the host by obstructing blood flow through small vessels. Endothelial nitric oxide (NO) would normally counteract these pathological changes, but NO signalling is diminished malaria. NO synthesis is inhibited by asymmetric dimethylarginine (ADMA), a methylated derivative of arginine that is released during normal protein turnover. We found the ratio of ADMA to arginine to be elevated in Gambian children with severe malaria, a metabolic disturbance known to inhibit NO synthesis. ADMA was associated with markers of endothelial activation and impaired tissue perfusion. In parallel experiments using mice, the enzyme responsible for metabolizing ADMA, dimethylarginine dimethylaminohydrolase (DDAH), was inactivated after infection with a rodent malaria. Based on these studies, we propose that decreased metabolism of ADMA by DDAH might contribute to the elevated ADMA/arginine ratio observed during an acute episode of malaria. Strategies to preserve or increase DDAH activity might improve NO synthesis and help to prevent the vascular manifestations of severe malaria.
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Affiliation(s)
- Jessica H. Chertow
- Laboratory of Malaria and Vector Research, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Matthew S. Alkaitis
- Laboratory of Malaria and Vector Research, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Headington Oxford, United Kingdom
| | - Glenn Nardone
- Research Technology Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Allison K. Ikeda
- Laboratory of Malaria and Vector Research, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | | | | | | | | | | | | | | | - Oliver Billker
- Wellcome Trust Sanger Institute, Hinxton Cambridge, United Kingdom
| | - David J. Conway
- MRC Unit, Fajara, The Gambia
- London School of Hygiene and Tropical Medicine, Bloomsbury, London, United Kingdom
| | | | - Hans Ackerman
- Laboratory of Malaria and Vector Research, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail:
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Carvalho LJDM, Moreira ADS, Daniel-Ribeiro CT, Martins YC. Vascular dysfunction as a target for adjuvant therapy in cerebral malaria. Mem Inst Oswaldo Cruz 2015; 109:577-88. [PMID: 25185000 PMCID: PMC4156451 DOI: 10.1590/0074-0276140061] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/02/2014] [Indexed: 12/27/2022] Open
Abstract
Cerebral malaria (CM) is a life-threatening complication of Plasmodium
falciparum malaria that continues to be a major global health problem.
Brain vascular dysfunction is a main factor underlying the pathogenesis of CM and can
be a target for the development of adjuvant therapies for the disease. Vascular
occlusion by parasitised red blood cells and vasoconstriction/vascular dysfunction
results in impaired cerebral blood flow, ischaemia, hypoxia, acidosis and death. In
this review, we discuss the mechanisms of vascular dysfunction in CM and the roles of
low nitric oxide bioavailability, high levels of endothelin-1 and dysfunction of the
angiopoietin-Tie2 axis. We also discuss the usefulness and relevance of the murine
experimental model of CM by Plasmodium berghei ANKA to identify
mechanisms of disease and to screen potential therapeutic interventions.
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Affiliation(s)
| | - Aline da Silva Moreira
- Laboratório de Pesquisas em Malária, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
| | | | - Yuri Chaves Martins
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, USA
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Mwanga-Amumpaire J, Carroll RW, Baudin E, Kemigisha E, Nampijja D, Mworozi K, Santorino D, Nyehangane D, Nathan DI, De Beaudrap P, Etard JF, Feelisch M, Fernandez BO, Berssenbrugge A, Bangsberg D, Bloch KD, Boum Y, Zapol WM. Inhaled Nitric Oxide as an Adjunctive Treatment for Cerebral Malaria in Children: A Phase II Randomized Open-Label Clinical Trial. Open Forum Infect Dis 2015; 2:ofv111. [PMID: 26309894 PMCID: PMC4542141 DOI: 10.1093/ofid/ofv111] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 07/21/2015] [Indexed: 11/27/2022] Open
Abstract
Treatment with inhaled nitric oxide as an adjuvant therapy for pediatric patients with cerebral malaria for 48 hours did not result in a significant difference in plasma Angiopoietin-1 levels when compared with placebo in a phase II open-label clinical trial. Background. Children with cerebral malaria (CM) have high rates of mortality and neurologic sequelae. Nitric oxide (NO) metabolite levels in plasma and urine are reduced in CM. Methods. This randomized trial assessed the efficacy of inhaled NO versus nitrogen (N2) as an adjunctive treatment for CM patients receiving intravenous artesunate. We hypothesized that patients treated with NO would have a greater increase of the malaria biomarker, plasma angiopoietin-1 (Ang-1) after 48 hours of treatment. Results. Ninety-two children with CM were randomized to receive either inhaled 80 part per million NO or N2 for 48 or more hours. Plasma Ang-1 levels increased in both treatment groups, but there was no difference between the groups at 48 hours (P = not significant [NS]). Plasma Ang-2 and cytokine levels (tumor necrosis factor-α, interferon-γ, interleukin [IL]-1β, IL-6, IL-10, and monocyte chemoattractant protein-1) decreased between inclusion and 48 hours in both treatment groups, but there was no difference between the groups (P = NS). Nitric oxide metabolite levels—blood methemoglobin and plasma nitrate—increased in patients treated with NO (both P < .05). Seven patients in the N2 group and 4 patients in the NO group died. Five patients in the N2 group and 6 in the NO group had neurological sequelae at hospital discharge. Conclusions. Breathing NO as an adjunctive treatment for CM for a minimum of 48 hours was safe, increased blood methemoglobin and plasma nitrate levels, but did not result in a greater increase of plasma Ang-1 levels at 48 hours.
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Affiliation(s)
| | - Ryan W Carroll
- Department of Anesthesia, Critical Care, and Pain Medicine ; Center for Global Health ; Pediatric Critical Care Medicine , MassGen Hospital for Children , Boston, Massachusetts ; Harvard Medical School , Cambridge, Massachusetts
| | | | | | | | | | | | | | | | - Pierre De Beaudrap
- UMI 233, Institut de Recherche Pour le Développement, Université Montpellier 1 , France
| | - Jean-François Etard
- Epicentre , Paris , France ; UMI 233, Institut de Recherche Pour le Développement, Université Montpellier 1 , France
| | | | | | | | - David Bangsberg
- Center for Global Health ; Harvard Medical School , Cambridge, Massachusetts
| | - Kenneth D Bloch
- Department of Anesthesia, Critical Care, and Pain Medicine ; Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital
| | - Yap Boum
- Epicentre Mbarara Research Centre ; Mbarara University of Science and Technology , Uganda
| | - Warren M Zapol
- Department of Anesthesia, Critical Care, and Pain Medicine ; Harvard Medical School , Cambridge, Massachusetts
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Nacer A, Movila A, Sohet F, Girgis NM, Gundra UM, Loke P, Daneman R, Frevert U. Experimental cerebral malaria pathogenesis--hemodynamics at the blood brain barrier. PLoS Pathog 2014; 10:e1004528. [PMID: 25474413 PMCID: PMC4256476 DOI: 10.1371/journal.ppat.1004528] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 10/17/2014] [Indexed: 12/16/2022] Open
Abstract
Cerebral malaria claims the lives of over 600,000 African children every year. To better understand the pathogenesis of this devastating disease, we compared the cellular dynamics in the cortical microvasculature between two infection models, Plasmodium berghei ANKA (PbA) infected CBA/CaJ mice, which develop experimental cerebral malaria (ECM), and P. yoelii 17XL (PyXL) infected mice, which succumb to malarial hyperparasitemia without neurological impairment. Using a combination of intravital imaging and flow cytometry, we show that significantly more CD8(+) T cells, neutrophils, and macrophages are recruited to postcapillary venules during ECM compared to hyperparasitemia. ECM correlated with ICAM-1 upregulation on macrophages, while vascular endothelia upregulated ICAM-1 during ECM and hyperparasitemia. The arrest of large numbers of leukocytes in postcapillary and larger venules caused microrheological alterations that significantly restricted the venous blood flow. Treatment with FTY720, which inhibits vascular leakage, neurological signs, and death from ECM, prevented the recruitment of a subpopulation of CD45(hi) CD8(+) T cells, ICAM-1(+) macrophages, and neutrophils to postcapillary venules. FTY720 had no effect on the ECM-associated expression of the pattern recognition receptor CD14 in postcapillary venules suggesting that endothelial activation is insufficient to cause vascular pathology. Expression of the endothelial tight junction proteins claudin-5, occludin, and ZO-1 in the cerebral cortex and cerebellum of PbA-infected mice with ECM was unaltered compared to FTY720-treated PbA-infected mice or PyXL-infected mice with hyperparasitemia. Thus, blood brain barrier opening does not involve endothelial injury and is likely reversible, consistent with the rapid recovery of many patients with CM. We conclude that the ECM-associated recruitment of large numbers of activated leukocytes, in particular CD8(+) T cells and ICAM(+) macrophages, causes a severe restriction in the venous blood efflux from the brain, which exacerbates the vasogenic edema and increases the intracranial pressure. Thus, death from ECM could potentially occur as a consequence of intracranial hypertension.
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Affiliation(s)
- Adéla Nacer
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Alexandru Movila
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Fabien Sohet
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
| | - Natasha M. Girgis
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Uma Mahesh Gundra
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - P'ng Loke
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Richard Daneman
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
| | - Ute Frevert
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
- * E-mail:
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39
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Plasmodium and mononuclear phagocytes. Microb Pathog 2014; 78:43-51. [PMID: 25450889 DOI: 10.1016/j.micpath.2014.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/14/2014] [Accepted: 11/19/2014] [Indexed: 01/13/2023]
Abstract
Plasmodium, the causative agent of malaria, initially multiplies inside liver cells and then in successive cycles inside erythrocytes, causing the symptoms of the disease. In this review, we discuss interactions between the extracellular and intracellular forms of the Plasmodium parasite and innate immune cells in the mammalian host, with a special emphasis on mononuclear phagocytes. We overview here what is known about the innate immune cells that interact with parasites, mechanisms used by the parasite to evade them, and the protective or detrimental contribution of these interactions on parasite progression through its life cycle and pathology in the host.
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40
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Cabrera A, Neculai D, Kain KC. CD36 and malaria: friends or foes? A decade of data provides some answers. Trends Parasitol 2014; 30:436-44. [PMID: 25113859 DOI: 10.1016/j.pt.2014.07.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/16/2014] [Accepted: 07/17/2014] [Indexed: 02/07/2023]
Abstract
The past 10 years have generated new insights into the complex interaction between CD36 (cluster of differentiation 36) and malaria. These range from the crystallization of the CD36 homolog, LIMPII (lysosomal integral membrane protein II), permitting modeling of CD36 and its binding to diverse ligands, to cell biology-based studies of CD36 and large population genetic studies assessing the association of CD36 polymorphisms and malarial disease severity. Collectively these lines of evidence indicate that a receptor other than CD36 is associated with severity. CD36 plays an important role in innate immunity and in the phagocytic uptake of multiple pathogens including malaria. CD36 polymorphisms lack association with severity, and isolates that cause severe disease primarily bind to endothelial protein C receptor (EPCR) rather than to CD36.
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Affiliation(s)
- Ana Cabrera
- Sandra Ann Rotman (SAR) Laboratories, SAR Centre, Toronto General Hospital, University Health Network, Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Dante Neculai
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Kevin C Kain
- Sandra Ann Rotman (SAR) Laboratories, SAR Centre, Toronto General Hospital, University Health Network, Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
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41
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Serghides L, McDonald CR, Lu Z, Friedel M, Cui C, Ho KT, Mount HTJ, Sled JG, Kain KC. PPARγ agonists improve survival and neurocognitive outcomes in experimental cerebral malaria and induce neuroprotective pathways in human malaria. PLoS Pathog 2014; 10:e1003980. [PMID: 24603727 PMCID: PMC3946361 DOI: 10.1371/journal.ppat.1003980] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 01/22/2014] [Indexed: 01/11/2023] Open
Abstract
Cerebral malaria (CM) is associated with a high mortality rate, and long-term neurocognitive impairment in approximately one third of survivors. Adjunctive therapies that modify the pathophysiological processes involved in CM may improve outcome over anti-malarial therapy alone. PPARγ agonists have been reported to have immunomodulatory effects in a variety of disease models. Here we report that adjunctive therapy with PPARγ agonists improved survival and long-term neurocognitive outcomes in the Plasmodium berghei ANKA experimental model of CM. Compared to anti-malarial therapy alone, PPARγ adjunctive therapy administered to mice at the onset of CM signs, was associated with reduced endothelial activation, and enhanced expression of the anti-oxidant enzymes SOD-1 and catalase and the neurotrophic factors brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the brains of infected mice. Two months following infection, mice that were treated with anti-malarials alone demonstrated cognitive dysfunction, while mice that received PPARγ adjunctive therapy were completely protected from neurocognitive impairment and from PbA-infection induced brain atrophy. In humans with P. falciparum malaria, PPARγ therapy was associated with reduced endothelial activation and with induction of neuroprotective pathways, such as BDNF. These findings provide insight into mechanisms conferring improved survival and preventing neurocognitive injury in CM, and support the evaluation of PPARγ agonists in human CM. Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection that is associated with long-term neurocognitive impairment in about a third of survivors even when optimal anti-malarial therapy is used. Since both the parasite and the host immune response to infection play a role in the development of CM, adjunctive therapies that modulate the host response, given in conjunction with anti-parasitic therapy, may improve survival and prevent neurocognitive injury. Here we examine the effects of PPARγ agonists on neurocongitive injury using a mouse model of CM. We demonstrate that PPARγ agonists, when administered with anti-malarials, protected mice from developing brain atrophy and neurocognitive impairment. This was associated with induction of anti-oxidant and neuroprotective pathways in the brains of infected mice. We also observed the same neuroprotective pathways induced in patients with falciparum malaria that received PPARγ adjunctive therapy. Our findings suggest that PPARγ agonists may be valuable in the treatment and prevention of CM-induced neurocognitive injury, and support the testing of PPARγ agonists in patients with CM.
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Affiliation(s)
- Lena Serghides
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
- SA Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network, Toronto, Ontario, Canada
- Women's College Research Institute, Women's College Hospital, Toronto, Ontario, Canada
- * E-mail:
| | - Chloe R. McDonald
- SA Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network, Toronto, Ontario, Canada
- Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ziyue Lu
- SA Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network, Toronto, Ontario, Canada
- Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Miriam Friedel
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Cheryl Cui
- Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Keith T. Ho
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Howard T. J. Mount
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Department of Psychiatry, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - John G. Sled
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Kevin C. Kain
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
- SA Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network, Toronto, Ontario, Canada
- Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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42
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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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43
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Liles WC, Kain KC. Endothelial activation and dysfunction in the pathogenesis of microvascular obstruction in severe malaria--a viable target for therapeutic adjunctive intervention. J Infect Dis 2014; 210:163-4. [PMID: 24443542 DOI: 10.1093/infdis/jiu035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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44
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Toxoplasma gondii upregulates interleukin-12 to prevent Plasmodium berghei-induced experimental cerebral malaria. Infect Immun 2014; 82:1343-53. [PMID: 24396042 DOI: 10.1128/iai.01259-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
A chronic infection with the parasite Toxoplasma gondii has previously been shown to protect mice against subsequent viral, bacterial, or protozoal infections. Here we have shown that a chronic T. gondii infection can prevent Plasmodium berghei ANKA-induced experimental cerebral malaria (ECM) in C57BL/6 mice. Treatment with soluble T. gondii antigens (STAg) reduced parasite sequestration and T cell infiltration in the brains of P. berghei-infected mice. Administration of STAg also preserved blood-brain barrier function, reduced ECM symptoms, and significantly decreased mortality. STAg treatment 24 h post-P. berghei infection led to a rapid increase in serum levels of interleukin 12 (IL-12) and gamma interferon (IFN-γ). By 5 days after P. berghei infection, STAg-treated mice had reduced IFN-γ levels compared to those of mock-treated mice, suggesting that reductions in IFN-γ at the time of ECM onset protected against lethality. Using IL-10- and IL-12βR-deficient mice, we found that STAg-induced protection from ECM is IL-10 independent but IL-12 dependent. Treatment of P. berghei-infected mice with recombinant IL-12 significantly decreased parasitemia and mortality. These data suggest that IL-12, either induced by STAg or injected as a recombinant protein, mediates protection from ECM-associated pathology potentially through early induction of IFN-γ and reduction in parasitemia. These results highlight the importance of early IL-12 induction in protection against ECM.
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45
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Functional roles for C5a and C5aR but not C5L2 in the pathogenesis of human and experimental cerebral malaria. Infect Immun 2013; 82:371-9. [PMID: 24191300 DOI: 10.1128/iai.01246-13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The host immune response plays an important role in the onset and progression of cerebral malaria (CM). The complement system is an essential component of the innate immune response to malaria, and its activation generates the anaphylatoxin C5a. To test the hypothesis that C5a signaling contributes to the pathogenesis of CM, we investigated a causal role for the C5a receptors C5aR and C5L2 in a mouse model of experimental CM (ECM) induced by Plasmodium berghei ANKA infection, and using a case-control design, we examined levels of C5a in plasma samples from Ugandan children presenting with CM or uncomplicated malaria (UM). In the ECM model, C5aR(-/-) mice displayed significantly improved survival compared to their wild-type (WT) counterparts (P = 0.004), whereas C5L2(-/-) mice showed no difference in survival from WT mice. Improved survival in C5aR(-/-) mice was associated with reduced levels of the proinflammatory cytokines tumor necrosis factor (TNF) and gamma interferon (IFN-γ) and the chemokine, monocyte chemoattractant protein 1 (MCP-1) (CCL2). Furthermore, endothelial integrity was enhanced, as demonstrated by increased levels of angiopoietin-1, decreased levels of angiopoietin-2 and soluble ICAM-1, and decreased Evans blue extravasation into brain parenchyma. In the case-control study, the median levels of C5a at presentation were significantly higher in children with CM versus those in children with UM (43.7 versus 22.4 ng/ml; P < 0.001). These findings demonstrate that C5a is dysregulated in human CM and contributes to the pathogenesis of ECM via C5aR-dependent inflammation and endothelial dysfunction.
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46
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Oliveira-Lima OC, Bernardes D, Xavier Pinto MC, Esteves Arantes RM, Carvalho-Tavares J. Mice lacking inducible nitric oxide synthase develop exacerbated hepatic inflammatory responses induced by Plasmodium berghei NK65 infection. Microbes Infect 2013; 15:903-10. [PMID: 23988520 DOI: 10.1016/j.micinf.2013.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 08/03/2013] [Accepted: 08/06/2013] [Indexed: 02/06/2023]
Abstract
Infection of mice with Plasmodium berghei NK65 represents a well-recognized malaria model in which infection is accompanied by an intense hepatic inflammatory response. Enzyme-inducible nitric oxide synthase is an important regulator of inflammation and leukocyte recruitment in microvessels, but these functions have yet to be evaluated in experimental malaria. In this study, we assessed the involvement of inducible nitric oxide synthase in inflammatory responses to murine experimental malaria induced by P. berghei NK65. We observed that wild type (WT) and nitric oxide synthase (iNOS)-deficient mice (iNOS(-/-)) mice showed similar levels of parasitemia following P. berghei NK65 infection, although infected iNOS(-/-) mice presented early mortality. Inducible nitric oxide synthase deficiency led to increased leukocyte rolling and adhesion to the liver in iNOS(-/-) mice relative to the WT animals, as observed via intravital microscopy. Infected iNOS(-/-) mice also exhibited increased hepatic leukocyte migration and subsequent liver damage, which was associated with high serum levels of the cytokines TNF-α, IL-6 and IL-10. Our data suggest potential role for the iNOS enzyme as a regulator of hepatic inflammatory response induced by P. berghei NK65-infection, and its absence leads to exacerbated inflammation and sequential associated-hepatic damage in the animals.
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Affiliation(s)
- Onésia Cristina Oliveira-Lima
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG 31270-901, Brazil
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47
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Transdermal glyceryl trinitrate as an effective adjunctive treatment with artemether for late-stage experimental cerebral malaria. Antimicrob Agents Chemother 2013; 57:5462-71. [PMID: 23979751 DOI: 10.1128/aac.00488-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Cerebral malaria (CM) is associated with low nitric oxide (NO) bioavailability, cerebrovascular constriction, occlusion, and hypoperfusion. Administration of exogenous NO partially prevents the neurological syndrome and associated vascular pathology in an experimental CM (ECM) mouse model. In this study, we evaluated the effects of transdermal glyceryl trinitrate in preventing ECM and, in combination with artemether, rescuing late-stage ECM mice from mortality. The glyceryl trinitrate and/or artemether effect on survival and clinical recovery was evaluated in C57BL/6 mice infected with P. berghei ANKA. NO synthase (NOS) expression in mouse brain was determined by Western blots. Mean arterial pressure (MAP) and pial arteriolar diameter were monitored using a tail-cuff blood pressure system and a cranial window preparation, respectively. Preventative administration of glyceryl trinitrate at 0.025 mg/h decreased ECM mortality from 67 to 11% and downregulated inducible NOS expression in the brain. When administered as adjunctive rescue therapy with artemether, glyceryl trinitrate increased survival from 47 to 79%. The adjunctive therapy caused a sustained reversal of pial arteriolar vasoconstriction in ECM mice, an effect not observed with artemether alone. Glyceryl trinitrate induced a 13% decrease in MAP in uninfected mice but did not further affect MAP in hypotensive ECM mice. Glyceryl trinitrate, when combined with artemether, was an effective adjunctive rescue treatment for ECM. This treatment ameliorated pial arteriolar vasospasm and did not significantly affect MAP. These results indicate that transdermal glyceryl trinitrate has potential to be considered as a candidate for adjunctive therapy for CM.
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48
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Hawkes M, Elphinstone RE, Conroy AL, Kain KC. Contrasting pediatric and adult cerebral malaria: the role of the endothelial barrier. Virulence 2013; 4:543-55. [PMID: 23924893 PMCID: PMC5359751 DOI: 10.4161/viru.25949] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Malaria affects millions of people around the world and a small subset of those infected develop cerebral malaria. The clinical presentation of cerebral malaria differs between children and adults, and it has been suggested that age-related changes in the endothelial response may account for some of these differences. During cerebral malaria, parasites sequester within the brain microvasculature but do not penetrate into the brain parenchyma and yet, the infection causes severe neurological symptoms. Endothelial dysfunction is thought to play an important role in mediating these adverse clinical outcomes. During infection, the endothelium becomes activated and more permeable, which leads to increased inflammation, hemorrhages, and edema in the surrounding tissue. We hypothesize that post-natal developmental changes, occurring in both endothelial response and the neurovascular unit, account for the differences observed in the clinical presentations of cerebral malaria in children compared with adults.
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49
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McCartney R, Saha S, Rees J, Lawy T, Mosaheb R. Inhaled Nitric Oxide: A Review of the Action, Current Literature, and An Analysis of its Use in the NHS Today. J Intensive Care Soc 2013. [DOI: 10.1177/175114371301400311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nitric oxide is a potent vasodilator which when inhaled causes dilatation in the pulmonary vasculature. It is this action that has been studied in intensive care medicine, especially in relation to hypoxic vasoconstriction associated with acute respiratory distress syndrome (ARDS). The use of inhaled nitric oxide has been shown to improve ventilation:perfusion matching, and thus to improve oxygenation. This article reviews the chemistry and clinical properties of nitric oxide as well as its potential uses, clinical effectiveness and side effects. The authors also surveyed UK intensive care units to review the current prevalence of the use of inhaled nitric oxide. It was found that while the majority do not currently use inhaled nitric oxide in ARDS patients, it had still been used in 27% (n=61) of the departments surveyed.
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Affiliation(s)
- Robert McCartney
- Year One Core Medical Trainee, Respiratory Medicine Department, Whipps Cross Hospital, Leytonstone, London
| | - Shibaji Saha
- Consultant Anaesthetist, Queen's Hospital, Romford, Essex
| | - James Rees
- Year One Anaesthetic Trainee, Queen's Hospital, Romford, Essex
| | - Tom Lawy
- Senior House Officer, Critical Care Department, Queen's Hospital, Romford, Essex
| | - Rishi Mosaheb
- Senior House Officer, Critical Care Department, Queen's Hospital, Romford, Essex
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50
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Frosch AEP, John CC. Immunomodulation in Plasmodium falciparum malaria: experiments in nature and their conflicting implications for potential therapeutic agents. Expert Rev Anti Infect Ther 2013; 10:1343-56. [PMID: 23241191 DOI: 10.1586/eri.12.118] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Effective Plasmodium falciparum immunity requires a precisely timed and balanced response of inflammatory and anti-inflammatory immune regulators. These responses begin with innate immune effectors and are modulated over the course of an infection and between episodes to limit inflammation. To date, there are no effective immunomodulatory therapies for severe malaria. Some of the most potent immunomodulators are naturally occurring infections, including helminthic and chronic viral infections. This review examines malaria coinfection with these organisms, and their impact on malaria morbidity and immune responses. Overall, there is compelling evidence to suggest that chronic coinfections can modulate deleterious malaria-specific immune responses, suggesting that therapeutic agents may be effective if utilized early in infection. Examination of the mechanisms of these effects may serve as a platform to identify more targeted and effective malaria immunomodulatory therapeutics.
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Affiliation(s)
- Anne E P Frosch
- University of Minnesota, Center for Infectious Diseases and Microbiology Translational Research and Division of Global Pediatrics, McGuire Translational Research Facility, 2001 6th Street SE, Minneapolis, MN 55455, USA.
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