Use Of Chloroquine Research Articles

When there is a pandemic there is no time to waste: should we have hydroxychloroquine in our armoury against COVID-19 infected patients?

The current use of chloroquine and/or hydroxychloroquine, a drug currently used to treat autoimmune rheumatic diseases, in treating severe acute respiratory syndrome caused by coronavirus 2 (SARSCoV-2) or COVID-19-infected patients with pneumonia is a matter of intense consideration. We wish to enter the ongoing debate as to whether this well-known drug must be given to Greek COVID-19-infected patients, especially those with pneumonia. Our arguments are based on the existing data and the capacity of the Greek health system to afford potent anti-viral treatments, which are under immense investigation. We propose several suggestions related to treatment of COVID-19 pneumonia with chloroquine/hydroxychloroquine that we think must be taken into consideration to fit the evolving situation of the pandemic in Greece.

Toward fully exploiting the therapeutic potential of marketed pharmaceuticals: the use of octreotide and chloroquine in oncology.

Pleiotropy in biological systems and their targeting allows many pharmaceuticals to be used for multiple therapeutic purposes. Fully exploiting the therapeutic properties of drugs that are already marketed would be highly advantageous. This is especially the case in the field of oncology, where the ineffectiveness of typical anticancer agents is a common issue, while the development of novel anticancer agents is a costly and particularly time-consuming process. Octreotide and chloroquine are two pharmaceuticals that exhibit profound antitumorigenic activities. However, the current therapeutic use of octreotide is restricted primarily to the management of acromegaly and neuroendocrine tumors, both of which are rare medical conditions. Similarly, chloroquine is used mainly for the treatment of malaria, which is designated as a rare disease in Western countries. This limited exploitation contradicts the experimental findings of numerous studies outlining the possible expansion of the use of octreotide to include the treatment of common human malignancies and the repositioning of chloroquine in oncology. Herein, we review the current knowledge on the antitumor function of these two agents stemming from preclinical or clinical experimentation. In addition, we present in silico evidence on octreotide potentially binding to multiple Wnt-pathway components. This will hopefully aid in the design of new efficacious anticancer therapeutic regimens with minimal toxicity, which represents an enormous unmet demand in oncology.

Lack of significant recovery of chloroquine sensitivity in Plasmodium falciparum parasites following discontinuance of chloroquine use in Papua New Guinea

BackgroundChloroquine treatment for Plasmodium falciparum has been discontinued in almost all endemic regions due to the spread of resistant isolates. Reversal of chloroquine susceptibility after chloroquine discontinuation has been reported in dozens of endemic regions. However, this phenomenon has been mostly observed in Africa and is not well documented in other malaria endemic regions. To investigate this, an ex vivo study on susceptibility to chloroquine and lumefantrine was conducted during 2016–2018 in Wewak, Papua New Guinea where chloroquine had been removed from the official malaria treatment regimen in 2010. Genotyping of pfcrt and pfmdr1 was also performed.ResultsIn total, 368 patients were enrolled in this study. Average IC50 values for chloroquine were 106.6, 80.5, and 87.6 nM in 2016, 2017, and 2018, respectively. These values were not significantly changed from those obtained in 2002/2003 (108 nM). The majority of parasites harboured a pfcrt K76T the mutation responsible for chloroquine resistance. However, a significant upward trend was observed in the frequency of the K76 (wild) allele from 2.3% in 2016 to 11.7% in 2018 (P = 0.008; Cochran–Armitage trend test).ConclusionsEight years of chloroquine withdrawal has not induced a significant recovery of susceptibility in Papua New Guinea. However, an increasing tendency of parasites harbouring chloroquine-susceptible K76 suggests a possibility of resurgence of chloroquine susceptibility in the future.

A Flow Cytometric Study of ER Stress and Autophagy.

The mechanistic link between ER stress, autophagy, and resultant cell death was investigated by the use of drugs Thapsigargin (Tg) and Chloroquine (CQ) with prior induction and or blockade of autophagy and apoptosis which modulated the ER stress response and resultant form of cell death. All these biological processes can be measured flow cytometrically allowing the determination of the type of cell death, G1 cell cycle arrest, cell cycle dependent measurement of ER stress transducer PERK, misfolded proteins, reticulophagy, and autophagy marker LC3B. Jurkat cells after Tg or CQ treatment became necrotic and apoptotic, showed G1 cell cycle arrest, autophagy, and ER stress. Prior induction of autophagy before ER stress increased levels of necrotic and apoptotic cell death. Autophagy was further up-regulated, while PERK was reduced or abrogated. CQ showed reduced levels of misfolded proteins and reticulophagy, while Tg showed no change in misfolded protein levels but increased reticulophagy and thus displayed more ER stress. Prior blockade of apoptosis before induction of ER stress resulted in cell survival except with high Tg levels which induced necrosis. Autophagy was up-regulated with modulation of PERK and reticulophagy levels with an abrogation of the misfolded protein response. Blockade of apoptosis with induction of autophagy before ER stress showed death by necrosis with high dose drugs and cell survival with low doses of drugs. CQ induced reduced levels G1 cell cycle arrest while it was maintained with Tg. Autophagy was also maintained with reduced levels of ER stress. These data demonstrates a profound link between the processes of ER stress, autophagy, and the resultant form of cell death all of which can be modulated depending upon the sequence and concentration of drugs employed. © 2018 International Society for Advancement of Cytometry.

Towards a re-emergence of chloroquine sensitivity in C\xf4te d\u2019Ivoire?

BackgroundResistance of Plasmodium falciparum to anti-malarial drugs has hampered efforts to eradicate malaria. Recent reports of a decline in the prevalence of chloroquine-resistant P. falciparum in several countries, including Malawi and Zambia, is raising the hope of reintroducing chloroquine in the near future, ideally in combination with another anti-malarial drug for the treatment of uncomplicated malaria. In Côte d’Ivoire, the decrease in the clinical efficacy of chloroquine, in addition to a high proportion of clinical isolates carrying the Thr-76 mutant allele of the pfcrt gene, had led to the discontinuation of the use of chloroquine in 2004. Previous studies have indicated the persistence of a high prevalence of the Thr-76 mutant allele despite the withdrawal of chloroquine as first-line anti-malarial drug. This present study is conducted to determine the prevalence of the Thr-76T mutant allele of the Pfcrt gene after a decade of the ban on the sale and use of chloroquine in Côte d’Ivoire.ResultsAnalysis of the 64 sequences from all three study sites indicated a prevalence of 15% (10/64) of the Thr-76 mutant allele against 62% (40/64) of the Lys-76 wild-type allele. No mutation of the allele Thr-76 was observed at Anonkoua Kouté while this mutant allele was in 31% (5/16) and 25% (5/20) of isolate sequences from Port-Bouët and Ayamé respectively.ConclusionMore than a decade after the discontinuation of the use of chloroquine in Côte d’Ivoire, the proportion of parasites sensitive to this anti-malarial seems to increase in Anonkoua-kouté, Port-bouët and Ayamé.

Chloroquine and nanoparticle drug delivery: A promising combination.

Clinically approved cancer therapies include small molecules, antibodies, and nanoparticles. There has been major progress in the treatment of several cancer types over recent decades. However, many challenges remain for optimal use of conventional and nanoparticle-based therapies in oncology including poor drug delivery, rapid clearance, and drug resistance. The antimalarial agent chloroquine has been found to mitigate some of these challenges by modulating cancer cells and the tissue microenvironment. Particularly, chloroquine was recently found to reduce immunological clearance of nanoparticles by resident macrophages in the liver, leading to increased tumor accumulation of nanodrugs. Additionally, chloroquine has been shown to improve drug delivery and efficacy through normalization of tumor vasculature and suppression of several oncogenic and stress-tolerance pathways, such as autophagy, that protect cancer cells from cytotoxic agents. This review will discuss the use of chloroquine as combination therapy to improve cancer treatment.

Current and Future Use of Chloroquine and Hydroxychloroquine in Infectious, Immune, Neoplastic, and Neurological Diseases: A Mini-Review.

The process of finding new therapeutic indications for currently used drugs, defined as 'repurposing', is receiving growing attention. Chloroquine and hydroxychloroquine, with an original indication to prevent or cure malaria, have been successfully used to treat several infectious (HIV, Q fever, Whipple's disease, fungal infections), rheumatological (systemic lupus erythematosus, antiphospholipid antibody syndrome, rheumatoid arthritis, Sjögren's syndrome), and other immunological diseases. Indeed, they have anti-inflammatory, immunomodulating, anti-infective, antithrombotic, and metabolic effects. Among the biological effects of chloroquine and hydroxychloroquine, it is important to highlight their antitumoral properties, likely due to their strong antiproliferative, antimutagenic, and inhibiting autophagy capacities. These effects make these drugs a possible option in the treatment of several tumors in association with radiotherapy and chemotherapy. Finally, the repurposing of chloroquine and hydroxychloroquine is currently being examined for neurological diseases such as neurosarcoidosis, chronic lymphocytic inflammation with pontine perivascular enhancement responsive to corticosteroids, and primary progressive multiple sclerosis. Several ongoing clinical trials have been testing these drugs in non-neoplastic and neoplastic diseases. Moreover, the well-demonstrated good tolerability of chloroquine and hydroxychloroquine make them safe even during pregnancy. Gastrointestinal and cutaneous manifestations are considered not to be serious, while retinal, neuromuscular, and cardiac toxicities are classified as serious adverse events.

Corneal Ulcer Following Prolonged Topical Chloroquine Phosphate

Chloroquine and hydroxychloroquine are well known weapons in a rheumatologist’s armamentarium. Chloroquine, (N’-(7-chloroquinolin-4-yl)-N,N-diethyl-pentane-1,4-diamine) is an antimalarial drug which has been in use since the early 1950s, in the treatment of Discoid and Systemic Lupus Erythematoses, Rheumatoid Arthritis and dermal light sensitivity eruptions. Hobbs in 1959 recognised a retinopathy which was produced by the long-term administration of this drug. Since the proposal of its anti-inflammatory effect, chloroquine phosphate has been used for the treatment of dry eyes. Among the many side-effects following systemic use of chloroquine; pruritus, urticaria, alopecia, lymphedema of forearm, headache, nausea etc are noteworthy. Ophthalmological complications like bull’s eye maculopathy, keratopathy, corneal deposits have also been observed, although infrequently. Majority of the complications arise from the long-term use of the drug which leads to its accumulation in specific sites. Here, we present a rare case report of sterile corneal ulcer following prolonged use of preservative free topical chloroquine phosphate (0.03%w/v) in the form of unims.

D-limonene exhibits antitumor activity by inducing autophagy and apoptosis in lung cancer

Purposed-limonene is a plant extract with widespread application, and it has been recently reported to have antiproliferative and proapoptotic effects on cancer cells. However, the mechanisms by which d-limonene achieves these effects, especially in lung cancer, are not entirely clear. Therefore, the goal of this study was to examine the effects of d-limonene on lung cancer and explore its mechanisms of action.MethodsWe examined the therapeutic effects of d-limonene on lung cancer cells and in a xenograft animal model by characterizing its effects on the pathways of apoptosis and autophagy. Cell proliferation was measured using the Cell Counting Kit-8, and apoptosis was determined by flow cytometric analysis. Levels of LC3 puncta, an autophagy marker, were analyzed by laser scanning confocal microscopy. Autophagy and apoptosis-related gene expression were assessed by real-time quantitative polymerase chain reaction and Western blot.Resultsd-limonene inhibited the growth of lung cancer cells and suppressed the growth of transplanted tumors in nude mice. Expression of apoptosis and autophagy-related genes were increased in tumors after treatment with d-limonene. Furthermore, the use of chloroquine, an autophagy inhibitor, and knockdown of the atg5 gene, suppressed the apoptosis induced by d-limonene.Conclusiond-limonene may have a therapeutic effect on lung cancer as it can induce apoptosis of lung cancer cells by promoting autophagy.

Autophagy Inhibition in Childhood Nephroblastoma and the Therapeutic Significance.

Autophagy is a physiological pathway characterized by lysosomedependent self-digestion to recycle damaged or superfluous cellular content. Deregulation of autophagy hampers the maintenance of cellular homeostasis and contributes to tumorigenesis. However, during anticancer therapy, autophagy activation contributes to development of resistance. Thus autophagy has been recognized as an important pathway and a therapeutic target in cancer. Nephroblastoma (Wilm's tumor) is a common childhood malignancy. The role of autophagy in nephroblastoma is largely uninvestigated. This study is to investigate the change of autophagy level in nephroblastoma, and whether autophagy could be a therapeutic target in anaplastic nephroblastoma. In clinical samples of childhood nephroblastoma, autophagy activity was evaluated by the expressions of selected autophagy markers as well as the presence of autophagosome ultrastructure. Use of autophagy inhibitors alone and in combination with conventional chemotherapeutics, was studied both in vivo and in vitro. In nephroblastoma, there was decrease in the Beclin 1 level and the number of autophagosomes, suggesting autophagy inhibition. Furthermore, in two anaplastic nephroblastoma cell lines, G401 and SK-NEP1, autophagy inhibitors further enhanced the efficacy of conventional chemotherapeutics including vincristine and cisplatin. In G401 tumor model established in nude mice, combinational use of chloroquine, an inhibitor of autophagy degradation, further decreased the tumor mass compared with single use of the chemotherapeutics vindesine, although no statistical significance was achieved. Our results suggest that autophagy deregulation is involved in nephroblastoma, and targeting autophagy can serve as a potential adjuvant strategy for the highly malignant cases.

Determination of Effect of Home-Based Oral Chloroquine Treatment on Haematological Indices of <i>P. falciparum</i> Malaria in Children under 5 Years in Jos Metropolis

Background: The incidence of P. falciparum malaria is characterized by high rates of morbidity and mortality in under 5 children; a trend reportedly prevalent in tropical and subtropical countries including Nigeria, and recently observed in Jos metropolis, has to date defied all constructive, preventive and drug therapy intervention measures and consequently continues to constitute a serious public health problem in this most vulnerable group. Objective: The aim of this study was to determine certain haematological indicators of malaria parasite infection; their role in the clinical manifestation of P. falciparum malaria and effect of first line oral chloroquine treatment in children under 5 years attending Jos University Teaching hospital and OLA Hospital in Jos metropolis. Method: This is a cross-sectional study of 93 malaria and non-malaria children, age 1 - 59 months attending Jos University Teaching Hospital (JUTH), Jos and OLA hospital, Jos, North Central Nigeria. Malaria diagnosis was carried out using microscopical examination of Leishman’s stained thick and thin blood films and complete blood count was done using Beckman Coulter Analyzer. Results: The mean percentage lymphocyte value of chloroquine treated children (39.28% ± 7.45%) was significantly lower than the control (66.38% ± 2.27%). The mean granulocyte value of chloroquine treated children (51.07% ± 6.40%) was significantly higher than the control (26.69% ± 2.43%). Red Blood Cell (RBC) counts (4.01 ± 0.21 × 106/μL), Haemoglobin concentration (9.60 ± 0.51 g/dl) and Haematocrit (30.97% ± 1.43%) of chloroquine treated children were significantly higher than corresponding values in untreated malarious children, but not significantly different from values obtained in non-malaria control children. The RBC counts (2.92 ± 0.39 × 106/μL), Haemoglobin concentration (7.23 ± 1.01 g/dl) and Haematocrit (23.70% ± 3.37%) obtained for untreated malarious children were significantly lower than corresponding values in the non-malarious control children. Conclusion: The pattern of the results obtained in this study suggests that home-based, first-line oral chloroquine treatment 24 hours prior hospital admission decreases the lymphocytes production and elevated production of granulocytes with attendant consequences on their biological functions. The chloroquine treatment seems to protect the red blood cells against the destructive effect of malaria. The haemoglobin concentration of 7.23 ± 1.01 g/dl obtained in untreated malaria children when combined with results of red blood cells; differential analysis indicates a mild, normocytic, normochromic anaemia due to haemolysis. This study demonstrates the beneficial effects of first aid, home-based oral chloroquine use. Rational use of chloroquine needs to be re-evaluated and encouraged in this group of children.

Effects of concurrent chloroquine and ethanol administration on the rat kidney morphology.

IntroductionThe use of antimalarial chloroquine in malaria-endemic regions of Africa is rampant and it is not uncommon to find individuals taken the drug concurrent with alcohol. Effects of anti-malarial drug chloroquine (Chq) and ethanol (Et) combination on kidney volume and function using rat model was investigated.Methods32 adult male rats were randomly distributed into four groups of 8 rats each. Group C serve as control and received vehicle only, while Q is Chq treated only, E is Et treated and QE is Et and Chq treated. Chq was administered intraperitoneally at 1mg/100g body weight weekly and 6% Et in drinking water provided ad libitum. Urine volume was collected before the treatment began and after the treatment. After eight weeks, all animals were euthanized; kidneys were harvested and fixed in 10% neutral formalin. The fixed left kidneys were scanned with computed tomography and the scan slices were used to estimate 3-dimensional kidney volume on ImageJ.ResultsTotal kidney volume was none significantly increased in Q, E and QE treated compared to control groups (p = 0.5150). Also, microscopic analysis showed increased proximal tubule diameter (p = 0.1426) and epithelial hypertrophy (p = 0.2530) and significant urinary space shrinkage (p = 0.00001). The initial urine volume was not significantly different between the control and treated groups (p = 0.9864) however, following treatment urine volume was significantly reduced in QE rats group (p = 0.0029).ConclusionThe results suggest chloroquine and ethanol combination as potential cause of kidney injury through structural damage and function derangement.

A chloroquine-induced macrophage-preconditioning strategy for improved nanodelivery

Site-specific localization is critical for improving the therapeutic efficacy and safety of drugs. Nanoparticles have emerged as promising tools for localized drug delivery. However, over 90% of systemically injected nanocarriers typically accumulate in the liver and spleen due to resident macrophages that form the mononuclear phagocyte system. In this study, the clinically approved antimalarial agent chloroquine was shown to reduce nanoparticle uptake in macrophages by suppressing endocytosis. Pretreatment of mice with a clinically relevant dose of chloroquine substantially decreased the accumulation of liposomes and silicon particles in the mononuclear phagocyte system and improved tumoritropic and organotropic delivery. The novel use of chloroquine as a macrophage-preconditioning agent presents a straightforward approach for addressing a major barrier in nanomedicine. Moreover, this priming strategy has broad applicability for improving the biodistribution and performance of particulate delivery systems. Ultimately, this study defines a paradigm for the combined use of macrophage-modulating agents with nanotherapeutics for improved site-specific delivery.

Ultrawide Field Imaging and OCT Angiography in Late-Onset Chloroquine Retinopathy

Purpose: To describe the clinical features of a 57-year-old female with palindromic rheumatism and a 15-year history of chloroquine use and bilateral vision loss. Methods: Ophthalmological examination, including ultrawide field (UWF) fundus images (Optomap-200TX) and cross-sectional retinal scans obtained with Zeiss spectral domain optical coherence tomography angiography (SD-OCTA, HD-5000, Angioplex), was performed. Results: Best-corrected visual acuity was 20/60 in both eyes. Ultrawide field fundus images revealed a ring-shaped area of pericentral and paracentral mottling of the retinal pigment epithelium (RPE), vascular attenuation, and loss of foveal reflex bilaterally. The SD-OCT showed obvious thinning in the outer retina, loss of the photoreceptor inner/outer segment junction corresponding to the location of the hypofluorescent lesion in the macular inferior temporal area, as well as a granular appearance of the RPE. Optical coherence tomography angiography showed the integrity of the superficial capillary plexus in both eyes, but the deep capillary plexus and the choriocapillaris layer detailed the loss of vasculature and the hyperreflective lesions located pericentrally. Multifocal central electroretinogram diminished in both the eyes. Conclusions: Optical coherence tomography angiography is able to show alterations produced by chloroquine toxicity. New technologies, such as UWF imaging and OCTA, could be suitable alternatives for screening and follow-up of chloroquine retinopathy.

TLR3 contributes to persistent autophagy and heart failure in mice after myocardial infarction.

Toll‐like receptors (TLRs) are essential immunoreceptors involved in host defence against invading microbes. Recent studies indicate that certain TLRs activate immunological autophagy to eliminate microbes. It remains unknown whether TLRs regulate autophagy to play a role in the heart. This study examined this question. The activation of TLR3 in cultured cardiomyocytes was observed to increase protein levels of autophagic components, including LC3‐II, a specific marker for autophagy induction, and p62/SQSTM1, an autophagy receptor normally degraded in the final step of autophagy. The results of transfection with a tandem mRFP‐GFP‐LC3 adenovirus and use of an autophagic flux inhibitor chloroquine both suggested that TLR3 in cardiomyocytes promotes autophagy induction without affecting autophagic flux. Gene‐knockdown experiments showed that the TRIF‐dependent pathway mediated the autophagic effect of TLR3. In the mouse model of chronic myocardial infarction, persistent autophagy was observed, concomitant with up‐regulated TLR3 expression and increased TLR3‐Trif signalling. Germline knockout (KO) of TLR3 inhibited autophagy, reduced infarct size, attenuated heart failure and improved survival. These protective effects were abolished by in vivo administration of an autophagy inducer rapamycin. Similar to the results obtained in cultured cardiomyocytes, TLR3‐KO did not prevent autophagic flux in mouse heart. Additionally, this study failed to detect the involvement of inflammation in TLR3‐KO‐derived protection, as wild‐type and TLR3‐KO hearts were comparable in inflammatory activity. It is concluded that up‐regulated TLR3 expression and signalling contributes to persistent autophagy following MI, which promotes heart failure and lethality.

Progressive increase in point mutations associates chloroquine resistance: Even after withdrawal of chloroquine use in India

Chloroquine (CQ) is highly effective against P. vivax, due to the rapid spread of CQ resistance in P. falciparum parasites; it is no longer the drug of choice against P. falciparum. This study elucidates the scenario of chloroquine efficacy at times that coincided with a new drug policy and especially assessed the chloroquine resistant molecular markers after withdrawal of chloroquine in Kolkata and Purulia, two malaria endemic zones of West Bengal, India. In vitro CQ susceptibility was tested in 781 patients with P. falciparum mono infections between 2008 and 2013, of which 338 patients had received CQ in 2008–2009. Genotyping of the pfcrt and the pfmdr1 gene was carried out in all isolates. Early treatment failure was detected in 114 patients {43 (31·39%) from Kolkata and 71 (35·32%) from Purulia} while recrudescence was identified in 13 (9.49%) and 17 (8.46%) patients from Kolkata and Purulia respectively. In vivo chloroquine resistance was strongly associated with CVMNT-YYSNY (p < 0.01) and SVMNT-YYSNY (p < 0.05) allele in Kolkata. In Purulia chloroquine resistance was associated with CVMNK-YYSNY (P < 0.005), SVMNT-YYSNY (P < 0.01) allele. The proportion of in vitro chloroquine resistance increased in subsequent years to 87.23% and 93·10% in 2013, in Kolkata and Purulia, respectively. Isolates with SVMNT-YFSND, SVMNT-YFSNY, CVIET-YFSND and CVIET-YYSNY haplotypes increased gradually (p < 0.05) from 2010 to 2013, leading to a rise in IC50 (p < 0.05) of chloroquine. An increase in in vitro chloroquine resistance and candidate gene mutations even after five years of chloroquine withdrawal against P. falciparum calls for synchronized research surveillance and proper containment strategies.

Pooled-DNA sequencing identifies genomic regions of selection in Nigerian isolates of Plasmodium falciparum

BackgroundThe burden of falciparum malaria is especially high in sub-Saharan Africa. Differences in pressure from host immunity and antimalarial drugs lead to adaptive changes responsible for high level of genetic variations within and between the parasite populations. Population-specific genetic studies to survey for genes under positive or balancing selection resulting from drug pressure or host immunity will allow for refinement of interventions.MethodsWe performed a pooled sequencing (pool-seq) of the genomes of 100 Plasmodium falciparum isolates from Nigeria. We explored allele-frequency based neutrality test (Tajima’s D) and integrated haplotype score (iHS) to identify genes under selection.ResultsFourteen shared iHS regions that had at least 2 SNPs with a score > 2.5 were identified. These regions code for genes that were likely to have been under strong directional selection. Two of these genes were the chloroquine resistance transporter (CRT) on chromosome 7 and the multidrug resistance 1 (MDR1) on chromosome 5. There was a weak signature of selection in the dihydrofolate reductase (DHFR) gene on chromosome 4 and MDR5 genes on chromosome 13, with only 2 and 3 SNPs respectively identified within the iHS window. We observed strong selection pressure attributable to continued chloroquine and sulfadoxine-pyrimethamine use despite their official proscription for the treatment of uncomplicated malaria. There was also a major selective sweep on chromosome 6 which had 32 SNPs within the shared iHS region. Tajima’s D of circumsporozoite protein (CSP), erythrocyte-binding antigen (EBA-175), merozoite surface proteins - MSP3 and MSP7, merozoite surface protein duffy binding-like (MSPDBL2) and serine repeat antigen (SERA-5) were 1.38, 1.29, 0.73, 0.84 and 0.21, respectively.ConclusionWe have demonstrated the use of pool-seq to understand genomic patterns of selection and variability in P. falciparum from Nigeria, which bears the highest burden of infections. This investigation identified known genomic signatures of selection from drug pressure and host immunity. This is evidence that P. falciparum populations explore common adaptive strategies that can be targeted for the development of new interventions.

C10ORF10/DEPP-mediated ROS accumulation is a critical modulator of FOXO3-induced autophagy

BackgroundNeuroblastoma is the most common solid tumor in childhood and develops from undifferentiated progenitor cells of the sympathetic nervous system. In neuronal tumor cells DNA-damaging chemotherapeutic agents activate the transcription factor FOXO3 which regulates the formation of reactive oxygen species (ROS) and cell death as well as a longevity program associated with therapy resistance.We demonstrated before that C10ORF10/DEPP, a transcriptional target of FOXO3, localizes to peroxisomes and mitochondria and impairs cellular ROS detoxification. In the present study, we investigated the impact of FOXO3 and DEPP on the regulation of autophagy. Autophagy serves to reduce oxidative damage as it triggers a self-degradative process for the removal of aggregated or misfolded proteins and damaged organelles.MethodsThe effect of FOXO3 and DEPP on autophagy induction was analyzed using live cell fluorescence microscopy and immunoblot analyses of SH-EP cells transfected with a plasmid for EYFP-LC3 and with siRNAs specific for LC3, respectively. ROS steady-state levels were measured with reduced MitoTrackerRed CM-H2XROS. Cellular apoptosis was analyzed by flow cytometry and the caspase 3/7 assay.ResultsWe report for the first time that DEPP induces ROS accumulation and thereby mediates the formation of autophagosomes as inhibition of ROS formation by N-acetyl-cysteine completely blocks autophagy. We further demonstrate that H2O2-treatment triggers autophagy-induction by FOXO3-mediated DEPP expression. Importantly, knockdown of DEPP was sufficient to efficiently inhibit autophagy-induction under different stress conditions such as serum starvation and genotoxic stress, suggesting that DEPP expression is critical for the initiation of autophagy in neuroblastoma. FOXO3-triggered autophagy partially protects neuroblastoma cells from cell death. Consistent with this concept, we demonstrate that inhibition of autophagy by LC3-knockdown significantly increased etoposide- and doxorubicin-induced apoptosis. These results were also confirmed by the use of the autophagy-inhibitor chloroquine that significantly enhanced the chemotherapeutic effect of etoposide and doxorubicin in neuronal tumor cells.ConclusionTargeting FOXO3/DEPP-triggered autophagy is a promising strategy to sensitize neuroblastoma cells to chemotherapy.

Using G6PD tests to enable the safe treatment of Plasmodium vivax infections with primaquine on the Thailand-Myanmar border: A cost-effectiveness analysis.

BackgroundPrimaquine is the only licensed antimalarial for the radical cure of Plasmodium vivax infections. Many countries, however, do not administer primaquine due to fear of hemolysis in those with glucose-6-phosphate dehydrogenase (G6PD) deficiency. In other settings, primaquine is given without G6PD testing, putting patients at risk of hemolysis. New rapid diagnostic tests (RDTs) offer the opportunity to screen for G6PD deficiency prior to treatment with primaquine. Here we assessed the cost-effectiveness of using G6PD RDTs on the Thailand-Myanmar border and provide the model as an online tool for use in other settings.Methods/Principal findingsDecision tree models for the management of P. vivax malaria evaluated the costs and disability-adjusted life-years (DALYs) associated with recurrences and primaquine-induced hemolysis from a health care provider perspective. Screening with G6PD RDTs before primaquine use was compared to (1) giving chloroquine alone and (2) giving primaquine without screening. Data were taken from a recent study on the impact of primaquine on P. vivax recurrences and a literature review. Compared to the use of chloroquine alone, the screening strategy had similar costs while averting 0.026 and 0.024 DALYs per primary infection in males and females respectively. Compared to primaquine administered without screening, the screening strategy provided modest cost savings while averting 0.011 and 0.004 DALYs in males and females respectively. The probabilistic sensitivity analyses resulted in a greater than 75% certainty that the screening strategy was cost-effective at a willingness to pay threshold of US$500, which is well below the common benchmark of per capita gross domestic product for Myanmar.Conclusions/SignificanceIn this setting G6PD RDTs could avert DALYs by reducing recurrences and reducing hemolytic risk in G6PD deficient patients at low costs or cost savings. The model results are limited by the paucity of data available in the literature for some parameter values, including the mortality rates for both primaquine-induced hemolysis and P. vivax. The online model provides an opportunity to use different parameter estimates to examine the validity of these findings in other settings.

Rottlerin-mediated inhibition of Toxoplasma gondii growth in BeWo trophoblast-like cells

Autophagy is a crucial and physiological process for cell survival from yeast to mammals, including protozoan parasites. Toxoplasma gondii, an intracellular parasite, typically exploits autophagic machinery of host cell; however host cell upregulates autophagy to combat the infection. Herein we tested the efficacy of Rottlerin, a natural polyphenol with autophagic promoting properties, against Toxoplasma infection on the chorioncarcinoma-derived cell line BeWo. We found that Rottlerin, at sub-toxic doses, induced morphological and biochemical alterations associated with autophagy and decreased Toxoplasma growth in infected cells. Although autophagy was synergically promoted by Toxoplasma infection in combination with Rottlerin treatment, the use of the autophagy inhibitor chloroquine revealed that Rottlerin anti-parasitic effect was largely autophagy-independent and likely mediated by the converging inhibitory effect of Rottlerin and Toxoplasma in host protein translation, mediated by mTOR inhibition and eIF2α phosphorylation. Both events, which on one hand could explain the additive effect on autophagy induction, on the other hand led to inhibition of protein synthesis, thereby depriving Toxoplasma of metabolically essential components for multiplication. We suggest that modulation of the competition between pathogen requirement and host cell defense might be an attractive, novel therapeutic approach against Toxoplasma infection and encourage the development of Rottlerin-based new therapeutic formulations.